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Sample records for benign aqueous biphasic

  1. Aqueous biphasic extraction

    SciTech Connect

    Chaiko, D.J.

    1994-02-01

    The aqueous biphasic separation (ABS) process, which involves the selective partitioning of ultrafine particles or solutes between two immiscible aqueous phases, is being evaluated for removing uranium from contaminated clay soils. Goal is to remove ultrafine U from the soil, leaving residues below regulatory cleanup limits. Tests were made using U-contaminated soil near the Fernald waste incinerator; over 80% of the soil is <45 {mu}m. All the biphasic systems used polyethylene glycol in combination with inorganic salt phase. Results: U was reduced from 500--600 mg/kg to about 90 mg/kg, and in some cases even down to 15 mg/kg. However, a soil sample from the Fernald storage pad area did not give encouraging results. Selective flocculation of soil particles and dissolution of U in the salt phase occurred but were not troublesome. Scaleup tests using uncontaminated clay mineral feed were successful. Operating costs for soil remediation using ABS is estimated to be $25--50 per ton. A pilot-scale column is being installed at ANL.

  2. Metal separations using aqueous biphasic partitioning systems

    SciTech Connect

    Chaiko, D.J.; Zaslavsky, B.; Rollins, A.N.; Vojta, Y.; Gartelmann, J.; Mego, W.

    1996-05-01

    Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that the authors have studied are generated by combining an aqueous salt solution with an aqueous polymer solution. They have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. They have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this report they review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation.

  3. Soil decontamination using aqueous biphasic separation

    SciTech Connect

    Chaiko, D.J.; Mensah-Biney, R.; Gupta, D.

    1994-02-01

    This paper summarizes efforts to develop a biphasic extraction process for separating ultrafine particulate contaminants from soils having high amounts of silt and clay. This work has thus far dealt with the removal of refractory uranium particles from the soils at Fernald, Ohio. The separation process involves the selective partitioning of ultra-fine particles between two immiscible aqueous phases. The authors have conducted batch extraction studies and are now beginning to scaleup the process for pilot-plant testing at Argonne National Laboratory (ANL). The results of these extraction studies are discussed.

  4. AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

    SciTech Connect

    K. Osseo-Asare; X. Zeng

    2002-01-01

    The objective of this research project is to develop an aqueous biphase extraction process for the treatment of fine coals. Aqueous biphase extraction is an advanced separation technology that relies on the ability of an aqueous system consisting of a water-soluble polymer and another component, e.g., another polymer, an inorganic salt, or a nonionic surfactant, to separate into two immiscible aqueous phases. The principle behind the partition of solid particles in aqueous biphase systems is the physicochemical interaction between the solid surface and the surrounding liquid solution. In order to remove sulfur and mineral matter from fine coal with aqueous biphasic extraction, it is necessary to know the partitioning behavior of coal, as well as the inorganic mineral components. Therefore, in this research emphasis was placed on the partitioning behavior of fine coal particles as well as model fine inorganic particles in aqueous biphase systems.

  5. Actinide recovery using aqueous biphasic extraction: Initial developmental studies

    SciTech Connect

    Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

    1992-08-01

    Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

  6. Actinide recovery using aqueous biphasic extraction: Initial developmental studies

    SciTech Connect

    Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

    1992-08-01

    Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

  7. Thermoreversible (Ionic-Liquid-Based) Aqueous Biphasic Systems

    PubMed Central

    Passos, Helena; Luís, Andreia; Coutinho, João A. P.; Freire, Mara G.

    2016-01-01

    The ability to induce reversible phase transitions between homogeneous solutions and biphasic liquid-liquid systems, at pre-defined and suitable operating temperatures, is of crucial relevance in the design of separation processes. Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated superior performance as alternative extraction platforms, and their thermoreversible behaviour is here disclosed by the use of protic ILs. The applicability of the temperature-induced phase switching is further demonstrated with the complete extraction of two value-added proteins, achieved in a single-step. It is shown that these temperature-induced mono(bi)phasic systems are significantly more versatile than classical liquid-liquid systems which are constrained by their critical temperatures. IL-based ABS allow to work in a wide range of temperatures and compositions which can be tailored to fit the requirements of a given separation process. PMID:26843320

  8. Thermoreversible (Ionic-Liquid-Based) Aqueous Biphasic Systems.

    PubMed

    Passos, Helena; Luís, Andreia; Coutinho, João A P; Freire, Mara G

    2016-02-04

    The ability to induce reversible phase transitions between homogeneous solutions and biphasic liquid-liquid systems, at pre-defined and suitable operating temperatures, is of crucial relevance in the design of separation processes. Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated superior performance as alternative extraction platforms, and their thermoreversible behaviour is here disclosed by the use of protic ILs. The applicability of the temperature-induced phase switching is further demonstrated with the complete extraction of two value-added proteins, achieved in a single-step. It is shown that these temperature-induced mono(bi)phasic systems are significantly more versatile than classical liquid-liquid systems which are constrained by their critical temperatures. IL-based ABS allow to work in a wide range of temperatures and compositions which can be tailored to fit the requirements of a given separation process.

  9. Thermoreversible (Ionic-Liquid-Based) Aqueous Biphasic Systems

    NASA Astrophysics Data System (ADS)

    Passos, Helena; Luís, Andreia; Coutinho, João A. P.; Freire, Mara G.

    2016-02-01

    The ability to induce reversible phase transitions between homogeneous solutions and biphasic liquid-liquid systems, at pre-defined and suitable operating temperatures, is of crucial relevance in the design of separation processes. Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have demonstrated superior performance as alternative extraction platforms, and their thermoreversible behaviour is here disclosed by the use of protic ILs. The applicability of the temperature-induced phase switching is further demonstrated with the complete extraction of two value-added proteins, achieved in a single-step. It is shown that these temperature-induced mono(bi)phasic systems are significantly more versatile than classical liquid-liquid systems which are constrained by their critical temperatures. IL-based ABS allow to work in a wide range of temperatures and compositions which can be tailored to fit the requirements of a given separation process.

  10. AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

    SciTech Connect

    K. Osseo-Asare; X. Zeng

    2001-06-30

    Ever-stringent environmental constraints dictate that future coal cleaning technologies be compatible with micron-size particles. This research program seeks to develop an advanced coal cleaning technology uniquely suited to micron-size particles, i.e., aqueous biphase extraction. The partitioning behaviors of hematite in the dextran (Dex)/Triton X-100 (TX100) and polyethylene glycol (PEG)/dextran systems were investigated and the effects of some ionic surfactants on solid partition were studied. In both biphase systems, the particles stayed in the bottom dextran-rich phase under all pH conditions. This behavior is attributable to the fact that the hydrophilic oxide particles prefer the more hydrophilic bottom phase. Also, the strong favorable interaction between dextran and ferric oxide facilitates the dispersion of the solids in the polysaccharide-rich phase. In the Dex/TX100 system, addition of sodium dodecylsulfate (SDS) or potassium oleate had no effect on the solid partition; on the other hand, addition of dodecyltrimethylammonium bromide (DTAB) transferred the particles to the top phase or interface at high pH values. In the PEG/Dex system, the preferred location of hematite remained the bottom phase in the presence of either SDS or DTAB. The effects of anionic surfactants on the partition behavior are attributable to the fact that they are not able to replace the strongly adsorbed polysaccharide layer on the ferric oxide surface. The results with the cationic surfactant are due to electrostatic interaction between the cationic surfactant and the charged surface of the solid particles. The difference in solids partitioning in the two systems is the result of the different distribution of DTAB in these systems. In the Dex/TX100 system, DTAB prefers the top surfactant-rich phase, while it concentrates in the bottom phase in the PEG/dextran system.

  11. AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

    SciTech Connect

    K. Osseo-Asare

    2000-06-02

    Ever-stringent environmental constraints dictate that future coal cleaning technologies be compatible with micron-size particles. This research program seeks to develop an advanced coal cleaning technology uniquely suited to micron-size particles, i.e., aqueous biphase extraction. The partitioning behavior of fly ash in the PEG-2000 Na{sub 2}SO{sub 4}/H{sub 2}O system was studied and the solid in each fraction was characterized by CHN analysis (carbon content), X-ray diffraction (XRD; crystal component), and inductively coupled plasma spectrophotometry (ICP; elemental composition in the ash). In the pH range from 2 to 5, the particles separated into two different layers, i.e., the polymer-rich (top) and salt-rich (bottom) layers. However, above pH 5, the particles in the polymer-rich phase split into two zones. The percent carbon content of the solids in the upper zone ({approximately}80 wt%) was higher than that in the parent sample (63.2 wt%), while the lower zone in the polymer-rich phase had the same percent ash content as the original sample. The particles in the salt-rich phase were mainly composed of ash (with < 4 wt% carbon content). However, when the solid concentration in the whole system increased from 1 wt% to 2 wt%, this 3-fraction phenomenon only occurred above pH 10. XRD results showed that the main crystal components in the ash included quartz, hematite, and mullite. The ICP results showed that Si, Al, and Fe were the major elements in the fly ash, with minor elements of Na, K, Ca, Mg, and Ba. The composition of the ash in the lower zone of the polymer-rich phase remained almost the same as that in the parent fly ash. The largest amount of product ({approximately}60% yield) with the highest carbon content ({approximately}80 wt% C) was obtained in the range pH 6-9. Based on the experimental results obtained, a flowsheet is proposed for the beneficiation of high-carbon fly ash with the aqueous biphase extraction process.

  12. Core-shell nanoreactors for efficient aqueous biphasic catalysis.

    PubMed

    Zhang, Xuewei; Cardozo, Andrés F; Chen, Si; Zhang, Wenjing; Julcour, Carine; Lansalot, Muriel; Blanco, Jean-François; Gayet, Florence; Delmas, Henri; Charleux, Bernadette; Manoury, Eric; D'Agosto, Franck; Poli, Rinaldo

    2014-11-17

    Water-borne phosphine-functionalized core-cross-linked micelles (CCM) consisting of a hydrophobic core and a hydrophilic shell were obtained as stable latexes by reversible addition-fragmentation chain transfer (RAFT) in water in a one-pot, three-step process. Initial homogeneous aqueous-phase copolymerization of methacrylic acid (MAA) and poly(ethylene oxide) methyl ether methacrylate (PEOMA) is followed by copolymerization of styrene (S) and 4-diphenylphosphinostyrene (DPPS), yielding P(MAA-co-PEOMA)-b-P(S-co-DPPS) amphiphilic block copolymer micelles (M) by polymerization-induced self-assembly (PISA), and final micellar cross-linking with a mixture of S and diethylene glycol dimethacrylate. The CCM were characterized by dynamic light scattering and NMR spectroscopy to evaluate size, dispersity, stability, and the swelling ability of various organic substrates. Coordination of [Rh(acac)(CO)2 ] (acac=acetylacetonate) to the core-confined phosphine groups was rapid and quantitative. The CCM and M latexes were then used, in combination with [Rh(acac)(CO)2 ], to catalyze the aqueous biphasic hydroformylation of 1-octene, in which they showed high activity, recyclability, protection of the activated Rh center by the polymer scaffold, and low Rh leaching. The CCM latex gave slightly lower catalytic activity but significantly less Rh leaching than the M latex. A control experiment conducted in the presence of the sulfoxantphos ligand pointed to the action of the CCM as catalytic nanoreactors with substrate and product transport into and out of the polymer core, rather than as a surfactant in interfacial catalysis.

  13. Aqueous biphasic plutonium oxide extraction process with pH and particle control

    DOEpatents

    Chaiko, D.J.; Mensah-Biney, R.

    1997-04-29

    A method is described for simultaneously partitioning a metal oxide and silica from a material containing silica and the metal oxide, using a biphasic aqueous medium having immiscible salt and polymer phases. 2 figs.

  14. AQUEOUS BIPHASE EXTRACTION FOR PROCESSING OF FINE COAL

    SciTech Connect

    K. Osseo-Asare; X. Zeng

    2001-06-30

    Ever-stringent environmental constraints dictate that future coal cleaning technologies be compatible with micron-size particles. This research program seeks to develop an advanced coal cleaning technology uniquely suited to micron-size particles, i.e., aqueous biphase extraction. The partitioning behaviors of silica in the polyethylene glycol (PEG)/dextran (Dex) and dextran/Triton X-100 (TX100) systems have been investigated, and the effects of sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) on solid partition have been studied. In both biphase systems, silica particles stayed in the top PEG-rich phase at low pH. With increase in pH, the particles moved from the top phase to the interface, then to the bottom phase. At very high pH, the solids preferred the top phase again. These trends are attributable to variations in the polymer/solid and nonionic surfactant/solid interactions. Addition of ionic surfactants into these two systems introduces a weakly charged environment, since ionic surfactants concentrate into one phase, either the top phase or the bottom phase. Therefore, coulombic forces also play a key role in the partition of silica particles because electrostatic attractive or repulsive forces are produced between the solid surface and the ionic-surfactant-concentrated phase. For the PEG/dextran system in the presence of SDS, SiO{sub 2} preferred the bottom dextran-rich phase above its pH{sub PZC}. However, addition of DTAB moved the oxide particles from the top phase to the interface, and then to the bottom phase, with increase in pH. These different behaviors are attributable to the fact that SDS and DTAB concentrated into the opposite phase of the PEG/dextran system. On the other hand, in the dextran/Triton X-100 system, both ionic surfactants concentrated in the top surfactant-rich phase and formed mixed micelles with TX100. Therefore, addition of the anionic surfactant, SDS, moved the silica particles from top phase to the

  15. Good's buffers as novel phase-forming components of ionic-liquid-based aqueous biphasic systems.

    PubMed

    Luís, Andreia; Dinis, Teresa B V; Passos, Helena; Taha, Mohamed; Freire, Mara G

    2015-09-15

    Aiming at the development of self-buffering and benign extraction/separation processes, this work reports a novel class of aqueous biphasic systems (ABS) composed of ionic liquids (ILs) and organic biological buffers (Good's buffers, GBs). A large array of ILs and GBs was investigated, revealing than only the more hydrophobic and fluorinated ILs are able to form ABS. For these systems, the phase diagrams, tie-lines, tie-line lengths, and critical points were determined at 25 °C. The ABS were then evaluated as alternative liquid-liquid extraction strategies for two amino acids (L-phenylalanine and L-tryptophan). The single-step extraction efficiencies for the GB-rich phase range between 22.4 and 100.0 % (complete extraction). Contrarily to the most conventional IL-salt ABS, in most of the systems investigated, the amino acids preferentially migrate for the most biocompatible and hydrophilic GB-rich phase. Remarkably, in two of the studied ABS, L-phenylalanine completely partitions to the GB-rich phase while L-tryptophan shows a preferential affinity for the opposite phase. These results show that the extraction efficiencies of similar amino acids can be tailored by the design of the chemical structures of the phase-forming components, creating thus new possibilities for the use of IL-based ABS in biotechnological separations.

  16. Enhanced tunability afforded by aqueous biphasic systems formed by fluorinated ionic liquids and carbohydrates.

    PubMed

    Ferreira, Ana M; Esteves, Pedro D O; Boal-Palheiros, Isabel; Pereiro, Ana B; Rebelo, Luís Paulo N; Freire, Mara G

    2016-02-21

    This work unveils the formation of novel aqueous biphasic systems (ABS) formed by perfluoroalkylsulfonate-based ionic liquids (ILs) and a large number of carbohydrates (monosaccharides, disaccharides and polyols) aiming at establishing more benign alternatives to the salts commonly used. The respective ternary phase diagrams were determined at 298 K. The aptitude of the carbohydrates to induce phase separation closely follows their hydration capability, while the length of the IL cation/anion fluorinated chain also plays a crucial role. Finally, these systems were investigated as liquid-liquid extraction strategies for four food dyes. Single-step extraction efficiencies for the carbohydrate-rich phase up to 94% were obtained. Remarkably and contrarily to the most investigated IL-salt ABS, most dyes preferentially migrate for the most hydrophilic and biocompatible carbohydrate-rich phase - an outstanding advantage when envisaging the products recovery and further use. On the other hand, more hydrophobic dyes preferentially partition to the IL-rich phase, disclosing therefore these novel systems as highly amenable to be tuned by the proper choice of the phase-forming components.

  17. Enhanced tunability afforded by aqueous biphasic systems formed by fluorinated ionic liquids and carbohydrates†

    PubMed Central

    Boal-Palheiros, Isabel; Pereiro, Ana B.; Rebelo, Luís Paulo N.; Freire, Mara G.

    2016-01-01

    This work unveils the formation of novel aqueous biphasic systems (ABS) formed by perfluoroalkylsulfonate-based ionic liquids (ILs) and a large number of carbohydrates (monosaccharides, disaccharides and polyols) aiming at establishing more benign alternatives to the salts commonly used. The respective ternary phase diagrams were determined at 298 K. The aptitude of the carbohydrates to induce phase separation closely follows their hydration capability, while the length of the IL cation/anion fluorinated chain also plays a crucial role. Finally, these systems were investigated as liquid–liquid extraction strategies for four food dyes. Single-step extraction efficiencies for the carbohydrate-rich phase up to 94% were obtained. Remarkably and contrarily to the most investigated IL-salt ABS, most dyes preferentially migrate for the most hydrophilic and biocompatible carbohydrate-rich phase – an outstanding advantage when envisaging the products recovery and further use. On the other hand, more hydrophobic dyes preferentially partition to the IL-rich phase, disclosing therefore these novel systems as highly amenable to be tuned by the proper choice of the phase-forming components. PMID:27667966

  18. A method for separating water soluble organics from a process stream by aqueous biphasic extraction

    SciTech Connect

    Chaiko, David J.; Mego, William A.

    1997-12-01

    The present invention relates to a method for separating water-miscible organic species from a process stream by aqueous biphasic extraction. In particular, the method includes extracting the organic species into a polymer-rich phase of an aqueous biphase system in which the process stream comprises the salt-rich phase, and, next, separating the polymer from the extracted organic species by contacting the loaded, polymer-rich phase with a water-immiscible organic phase. Alternatively, the polymer can be separated from the extracted organic species by raising the temperature of the loaded, polymer-rich phase above the cloud point, such that the polymer and the water-soluble organic species separate into two distinct aqueous phases. In either case, a substantially salt-free, concentrated aqueous solution containing the organic species is recovered.

  19. Aqueous biphasic extraction process with pH and particle control

    DOEpatents

    Chaiko, D.J.; Mensah-Biney, R.

    1995-05-02

    A process for aqueous biphasic extraction of metallic oxides and the like from substances containing silica. Control of media pH enables efficient and effective partition of mixture components. The inventive method may be employed to remove excess silica from kaolin clay. 2 figs.

  20. Aqueous biphasic extraction process with pH and particle control

    DOEpatents

    Chaiko, David J.; Mensah-Biney, R.

    1995-01-01

    A process for aqueous biphasic extraction of metallic oxides and the like from substances containing silica. Control of media pH enables efficient and effective partition of mixture components. The inventive method may be employed to remove excess silica from kaolin clay.

  1. Selection of Xenobiotic-Degrading Microorganisms in a Biphasic Aqueous-Organic System

    PubMed Central

    Ascon-Cabrera, Miguel; Lebeault, Jean-Michel

    1993-01-01

    Microbial selection on mixtures of chlorinated and nonchlorinated compounds that are poorly soluble in water and/or toxic to growing microbial cells was examined in both biphasic aqueous-organic and monophasic aqueous systems. A biphasic system in which silicone oil was used as the organic phase permitted the acceleration of acclimation, leading to rapid selection and to an increase in xenobiotic compound degradation. In contrast, acclimation, selection, and degradation were very slow in the monophasic aqueous system. The variation in microbial growth rate with the degree of dispersion (i.e., dispersion at different silicone oil concentrations and agitation rates), and cell adhesion to the silicone oil indicate that the performance of the biphasic aqueous-organic system is dependent on the interfacial area between the two phases and that microbial activity is important at this interface. Therefore, the biphasic water-silicone oil system could be used for microbial selection in the presence of xenobiotic compounds that are toxic and have low water solubility. PMID:16348949

  2. Single and Combination Drug Screening with Aqueous Biphasic Tumor Spheroids.

    PubMed

    Shahi Thakuri, Pradip; Tavana, Hossein

    2017-03-01

    Spheroids of cancer cells represent a physiologic model of solid tumors for cancer drug screening. Despite this known benefit, difficulties with generating large quantities of uniformly sized spheroids in standard plates, individually addressing spheroids with drug compounds, and quantitatively analyzing responses of cancer cells have hindered the use of spheroids in high-throughput screening applications. Recently, we addressed this challenge by using an aqueous two-phase system technology to generate a spheroid within an aqueous drop immersed in a second, immiscible aqueous phase. Integrating this approach with robotics resulted in convenient formation, maintenance, and drug treatment of spheroids. Here, we demonstrate the feasibility of high-throughput compound screening against colon cancer spheroids using 25 anticancer compounds. Using a strictly standardized mean difference and based on a preliminary testing with each compound, we select effective compounds for further dose-response testing. Finally, we use molecular inhibitors to target upregulated protein kinases and use them for drug combination studies against spheroids. We quantitatively analyze the combination treatment results using statistical metrics to identify synergy between pairs of inhibitors in compromising viability of colon cancer cells. This study demonstrates the utility of our spheroid culture technology for identification of effective drug compounds, dose-response analysis, and combination drug treatments.

  3. Aqueous Biphasic Systems Based on Salting-Out Polyethylene Glycol or Ionic Solutions: Strategies for Actinide or Fission Product Separations

    SciTech Connect

    Rogers, Robin D.; Gutowski, Keith E.; Griffin, Scott T.; Holbrey, John D.

    2004-03-29

    Aqueous biphasic systems can be formed by salting-out (with kosmotropic, waterstructuring salts) water soluble polymers (e.g., polyethylene glycol) or aqueous solutions of a wide range of hydrophilic ionic liquids based on imidazolium, pyridinium, phosphonium and ammonium cations. The use of these novel liquid/liquid biphases for separation of actinides or other fission products associated with nuclear wastes (e.g., pertechnetate salts) has been demonstrated and will be described in this presentation.

  4. Method for separating water soluble organics from a process stream by aqueous biphasic extraction

    DOEpatents

    Chaiko, David J.; Mego, William A.

    1999-01-01

    A method for separating water-miscible organic species from a process stream by aqueous biphasic extraction is provided. An aqueous biphase system is generated by contacting a process stream comprised of water, salt, and organic species with an aqueous polymer solution. The organic species transfer from the salt-rich phase to the polymer-rich phase, and the phases are separated. Next, the polymer is recovered from the loaded polymer phase by selectively extracting the polymer into an organic phase at an elevated temperature, while the organic species remain in a substantially salt-free aqueous solution. Alternatively, the polymer is recovered from the loaded polymer by a temperature induced phase separation (cloud point extraction), whereby the polymer and the organic species separate into two distinct solutions. The method for separating water-miscible organic species is applicable to the treatment of industrial wastewater streams, including the extraction and recovery of complexed metal ions from salt solutions, organic contaminants from mineral processing streams, and colorants from spent dye baths.

  5. Method for separating water soluble organics from a process stream by aqueous biphasic extraction

    SciTech Connect

    Chaiko, D.J.; Mego, W.A.

    1999-09-07

    A method for separating water-miscible organic species from a process stream by aqueous biphasic extraction is provided. An aqueous biphase system is generated by contacting a process stream comprised of water, salt, and organic species with an aqueous polymer solution. The organic species transfer from the salt-rich phase to the polymer-rich phase, and the phases are separated. Next, the polymer is recovered from the loaded polymer phase by selectively extracting the polymer into an organic phase at an elevated temperature, while the organic species remain in a substantially salt-free aqueous solution. Alternatively, the polymer is recovered from the loaded polymer by a temperature induced phase separation (cloud point extraction), whereby the polymer and the organic species separate into two distinct solutions. The method for separating water-miscible organic species is applicable to the treatment of industrial wastewater streams, including the extraction and recovery of complexed metal ions from salt solutions, organic contaminants from mineral processing streams, and colorants from spent dye baths.

  6. Aqueous biphasic systems for metal separations : a microcalorimetric analysis of polymer/salt interactions.

    SciTech Connect

    Chaiko, D. J.; Hatton, T. A.; Zaslavsky, B.

    1999-05-03

    Certain radionuclide ions (e.g., TcO{sub 4}{sup 16}) exhibit unusually strong Affinities toward the polymer-rich phase in aqueous biphase systems generated by combinations of salt solutions with polymers such as poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG). Thus, aqueous polymer phases could potentially be used to selectively extract these ions during pretreatment of radioactive tank wastes at Hanford. To help develop a fundamental understanding of the interactions between various ions and polymers in aqueous solution, interaction enthalpies between sodium perrhenate and a random copolymer of PEG and PPG (UCON-50) were measured by microcalorimetric titration. An entropy compensation effect was observed in this system in which changes in enthalpic interactions were balanced by entropy changes such that the interaction free energy remained constant and approximately equal to zero.

  7. Removal of textile dyes from textile dye effluent using TBAB based aqueous biphasic systems.

    PubMed

    Dilip, Meghna; Venkateswaran, P; Palanivelu, K

    2005-07-01

    Aqueous biphasic systems (ABS) are useful for the extraction of dye molecules from aqueous solution. Thus, they can be used in textile dye bath effluent treatment. The partitioning behavior of two commercially used textile dyes-Cibacron Scarlet LS 2G and Astacryl Red 3B were investigated in a TBAB-salt aqueous biphasic systems. It was found that all three salts, namely sodium chloride, sodium sulphate and sodium carbonate, investigated caused partitioning of dye into the upper TBAB rich phase. The efficiency of separation increased in the order NaCl < Na2SO4 < Na2CO. It was found that the cationic dye partitioned better than the anionic dye in the system. A concentration of 5 g/l of dye was extracted into the upper layer. Alteration of solution pH did not cause any significant difference in distribution ratios. Studies were extended to actual dye bath effluent and small scale up studies carried out. Efficiencies of removal obtained in all cases were extremely good with maximum efficiencies above 98 %.

  8. Aqueous biphasic extraction of uranium and thorium from contaminated soils. Final report

    SciTech Connect

    Chaiko, D.J.; Gartelmann, J.; Henriksen, J.L.; Krause, T.R.; Deepak; Vojta, Y.; Thuillet, E.; Mertz, C.J.

    1995-07-01

    The aqueous biphasic extraction (ABE) process for soil decontamination involves the selective partitioning of solutes and fine particulates between two immiscible aqueous phases. The biphase system is generated by the appropriate combination of a water-soluble polymer (e.g., polyethlene glycol) with an inorganic salt (e.g., sodium carbonate). Selective partitioning results in 99 to 99.5% of the soil being recovered in the cleaned-soil fraction, while only 0.5 to 1% is recovered in the contaminant concentrate. The ABE process is best suited to the recovery of ultrafine, refractory material from the silt and clay fractions of soils. During continuous countercurrent extraction tests with soil samples from the Fernald Environmental Management Project site (Fernald, OH), particulate thorium was extracted and concentrated between 6- and 16-fold, while the uranium concentration was reduced from about 500 mg/kg to about 77 mg/kg. Carbonate leaching alone was able to reduce the uranium concentration only to 146 mg/kg. Preliminary estimates for treatment costs are approximately $160 per ton of dry soil. A detailed flowsheet of the ABE process is provided.

  9. Non-conventional solvents in liquid phase microextraction and aqueous biphasic systems.

    PubMed

    An, Jiwoo; Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L

    2017-06-02

    The development of rapid, convenient, and high throughput sample preparation approaches such as liquid phase microextraction techniques have been continuously developed over the last decade. More recently, significant attention has been given to the replacement of conventional organic solvents used in liquid phase microextraction techniques in order to reduce toxic waste and to improve selectivity and/or extraction efficiency. With these objectives, non-conventional solvents have been explored in liquid phase microextraction and aqueous biphasic systems. The utilized non-conventional solvents include ionic liquids, magnetic ionic liquids, and deep eutectic solvents. They have been widely used as extraction solvents or additives in various liquid phase microextraction modes including dispersive liquid-liquid microextraction, single-drop microextraction, hollow fiber-liquid phase microextraction, as well as in aqueous biphasic systems. This review provides an overview into the use of non-conventional solvents in these microextraction techniques in the past 5 years (2012-2016). Analytical applications of the techniques are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Extraction of Biomolecules Using Phosphonium-Based Ionic Liquids + K3PO4 Aqueous Biphasic Systems

    PubMed Central

    Louros, Cláudia L. S.; Cláudio, Ana Filipa M.; Neves, Catarina M. S. S.; Freire, Mara G.; Marrucho, Isabel M.; Pauly, Jérôme; Coutinho, João A. P.

    2010-01-01

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K3PO4 solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K3PO4 at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS. PMID:20480041

  11. Extraction of biomolecules using phosphonium-based ionic liquids + K(3)PO(4) aqueous biphasic systems.

    PubMed

    Louros, Cláudia L S; Cláudio, Ana Filipa M; Neves, Catarina M S S; Freire, Mara G; Marrucho, Isabel M; Pauly, Jérôme; Coutinho, João A P

    2010-04-15

    Aqueous biphasic systems (ABS) provide an alternative and efficient approach for the extraction, recovery and purification of biomolecules through their partitioning between two liquid aqueous phases. In this work, the ability of hydrophilic phosphonium-based ionic liquids (ILs) to form ABS with aqueous K(3)PO(4) solutions was evaluated for the first time. Ternary phase diagrams, and respective tie-lines and tie-lines length, formed by distinct phosphonium-based ILs, water, and K(3)PO(4) at 298 K, were measured and are reported. The studied phosphonium-based ILs have shown to be more effective in promoting ABS compared to the imidazolium-based counterparts with similar anions. Moreover, the extractive capability of such systems was assessed for distinct biomolecules (including amino acids, food colourants and alkaloids). Densities and viscosities of both aqueous phases, at the mass fraction compositions used for the biomolecules extraction, were also determined. The evaluated IL-based ABS have been shown to be prospective extraction media, particularly for hydrophobic biomolecules, with several advantages over conventional polymer-inorganic salt ABS.

  12. Lipase in biphasic alginate beads as a biocatalyst for esterification of butyric acid and butanol in aqueous media.

    PubMed

    Ng, Choong Hey; Yang, Kun-Lin

    2016-01-01

    Esterification of organic acids and alcohols in aqueous media is very inefficient due to thermodynamic constraints. However, fermentation processes used to produce organic acids and alcohols are often conducted in aqueous media. To produce esters in aqueous media, biphasic alginate beads with immobilized lipase are developed for in situ esterification of butanol and butyric acid. The biphasic beads contain a solid matrix of calcium alginate and hexadecane together with 5 mg/mL of lipase as the biocatalyst. Hexadecane in the biphasic beads serves as an organic phase to facilitate the esterification reaction. Under optimized conditions, the beads are able to catalyze the production of 0.16 mmol of butyl butyrate from 0.5 mmol of butyric acid and 1.5 mmol of butanol. In contrast, when monophasic beads (without hexadecane) are used, only trace amount of butyl butyrate is produced. One main application of biphasic beads is in simultaneous fermentation and esterification (SFE) because the organic phase inside the beads is very stable and does not leach out into the culture medium. SFE is successfully conducted with an esterification yield of 6.32% using biphasic beads containing iso-octane even though the solvent is proven toxic to the butanol-producing Clostridium spp.

  13. INVESTIGATION OF AQUEOUS BIPHASIC SYSTEMS FOR THE SEPARATIONS OF LIGNINS FROM CELLULOSE IN THE PAPER PULPING PROCESS. (R826732)

    EPA Science Inventory

    In efforts to apply a polymer-based aqueous biphasic system (ABS) extraction to the paper pulping process, the study of the distribution of various lignin and cellulosic fractions in ABS and the effects of temperature on system composition and solute partitioning have been inv...

  14. INVESTIGATION OF AQUEOUS BIPHASIC SYSTEMS FOR THE SEPARATIONS OF LIGNINS FROM CELLULOSE IN THE PAPER PULPING PROCESS. (R826732)

    EPA Science Inventory

    In efforts to apply a polymer-based aqueous biphasic system (ABS) extraction to the paper pulping process, the study of the distribution of various lignin and cellulosic fractions in ABS and the effects of temperature on system composition and solute partitioning have been inv...

  15. New technetium-99m generator technologies utilizing polyethylene glycol-based aqueous biphasic systems

    SciTech Connect

    Rogers, R.D.; Bond, A.H.; Zhang, Jianhua; Horwitz, P.

    1995-12-31

    Two new schemes for TcO{sub 4}{sup {minus}}/MoO{sub 4}{sup 2{minus}} separations from OH{sup {minus}} and MoO{sub 4}{sup 2{minus}} media using polyethylene glycol (PEG)-based aqueous biphasic systems (ABS) have been developed. The two most important salt solutions in current {sup 99m}Tc-generator technologies, OH{sup {minus}} and MoO{sub 4}{sup 2{minus}}, also salt out PEG to form ABS. In liquid/liquid PEG- ABS, pertechnetate can be separated from molybdate with separation factors as high as 10,000. Stripping is accomplished by reduction of the TcO{sub 4}{sup {minus}} and back extraction into a salt solution. the strip solution can be the salt of an imaging agent (e.g., Na{sub 4}HEDPA) and thus may, under the appropriate conditions, be injected directly into the human body. {sup 99m}TcO{sub 4}{sup {minus}} can also be concentrated from a dilute load solution of {sup 99}MoO{sub 4}{sup 2{minus}} in NaOH using an aqueous biphasic extraction chromatographic technique (ABEC). A rinse with K{sub 2}CO{sub 3} assures that all {sup 99}MoO{sub 4}{sup 2{minus}} is removed from the column and this is confirmed by a rapid drop in {sup 99}Mo activity by the fourth free column volume (fcv) of rinse. The {sup 99m}TcO{sub 4}{sup {minus}} is then eluted with water. This chromatographic separation affords 94% of the {sup 99m}TcO{sub 4}{sup {minus}} activity in 5 fcv, with the y spectrum showing less than 2 {times} 10{sup {minus}4} of the original {sup 99}Mo activity.

  16. (R)-PAC biosynthesis in [BMIM][PF₆]/aqueous biphasic system using Saccharomyces cerevisiae BY4741 cells.

    PubMed

    Kandar, Smita; Suresh, A K; Noronha, Santosh B

    2015-02-01

    (R)-phenylacetylcarbinol or (R)-PAC is a pharmaceutical precursor of (1R, 2S) ephedrine and (1S, 2S) pseudoephedrine. Biotransformation of benzaldehyde and glucose by pyruvate decarboxylase produces (R)-PAC. This biotransformation suffers from toxicity of the substrate, product [(R)-PAC] and by-product (benzyl alcohol). In the present study, ionic liquid/aqueous biphasic system was employed to enhance (R)-PAC production. Fermented broth was the reaction medium in which Saccharomyces cerevisiae BY4741 was the source of pyruvate decarboxylase. Hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) was the non-aqueous phase in which toxic compounds reside. Biocompatibility of [BMIM][PF6] and adequate distribution coefficients of benzaldehyde, (R)-PAC and benzyl alcohol were determined. A Box-Behnken design and response surface methodology were used for the optimization of biotransformation variables in order to maximize (R)-PAC yield and productivity. The results showed higher (R)-PAC yield and productivity of ∼1.5-fold each in the biphasic biotransformation of phase volume ratio 0.05 as compared to the monophasic (conventional) biotransformation. Moreover, the level of major by-product benzyl alcohol was also 3.5-fold lower in biphasic biotransformation. [BMIM][PF6]/aqueous biphasic system is a new approach which could intensify the (R)-PAC production.

  17. Improved extraction of fluoroquinolones with recyclable ionic-liquid-based aqueous biphasic systems.

    PubMed

    Almeida, Hugo F D; Freire, Mara G; Marrucho, Isabel M

    2016-05-07

    In the past few years, the improvement of advanced analytical tools allowed to confirm the presence of trace amounts of metabolized and unchanged active pharmaceutical ingredients (APIs) in wastewater treatment plants (WWTPs) as well as in freshwater surfaces. It is known that the continuous contact with APIs, even at very low concentrations (ng L(-1)-μg L(-1)), leads to serious human health problems. In this context, this work shows the feasibility of using ionic-liquid-based aqueous biphasic systems (IL-based ABS) in the extraction of quinolones present in aqueous media. In particular, ABS composed of imidazolium- and phosphonium-based ILs and aluminium-based salts (already used in water treatment plants) were evaluated in one-step extractions of six fluoroquinolones (FQs), namely ciprofloxacin, enrofloxacin, moxifloxacin, norfloxacin, ofloxacin and sarafloxacin, and extraction efficiencies up to 98% were obtained. Despite the large interest devoted to IL-based ABS as extractive systems of outstanding performance, their recyclability/reusability has seldomly been studied. An efficient extraction/cleaning process of the IL-rich phase is here proposed by FQs induced precipitation. The recycling of the IL and its further reuse without losses in the ABS extractive performance for FQs were established, as confirmed by the four consecutive removal/extraction cycles evaluated. This novel recycling strategy supports IL-based ABS as sustainable and cost-efficient extraction platforms.

  18. Single-Step Purification of Ovalbumin from Egg White Using Aqueous Biphasic Systems

    PubMed Central

    Pereira, Matheus M.; Cruz, Rafaela A. P.; Almeida, Mafalda R.; Lima, Álvaro S.; Coutinho, João A. P.; Freire, Mara G.

    2016-01-01

    The ability of aqueous biphasic systems (ABS) composed of polyethylene glycols of different molecular weights (PEG 400, 600 and 1000) and buffered aqueous solutions of potassium citrate/citric acid (pH = 5.0 - 8.0) to selectively extract ovalbumin from egg white was here investigated. Phase diagrams, tie-lines and tie-line lengths were determined at 25ºC and the partitioning of ovalbumin in these systems was then evaluated. Aiming at optimizing the selective extraction of ovalbumin in the studied ABS, factors such as pH, PEG molecular weight and amount of the phase-forming components were initially investigated with pure commercial ovalbumin. In almost all ABS, it was observed a preferential partitioning of ovalbumin to the polymer-rich phase, with extraction efficiencies higher than 90%. The best ABS were then applied in the purification of ovalbumin from the real egg white matrix. In order to ascertain on the ovalbumin purity and yield, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion high performance liquid chromatography (SE-HPLC) analyses were conducted, confirming that the isolation/purification of ovalbumin from egg white was completely achieved in a single-step with a recovery yield of 65%. The results obtained show that polymer-salt-based ABS allow the selective extraction of ovalbumin from egg white with a simpler approach and better performance than previously reported. Finally, it is shown that ovalbumin can be completely recovered from the PEG-rich phase by an induced precipitation using an inexpensive and sustainable separation platform which can be easily applied on an industrial scale. PMID:27642253

  19. Single-Step Purification of Ovalbumin from Egg White Using Aqueous Biphasic Systems.

    PubMed

    Pereira, Matheus M; Cruz, Rafaela A P; Almeida, Mafalda R; Lima, Álvaro S; Coutinho, João A P; Freire, Mara G

    2016-06-01

    The ability of aqueous biphasic systems (ABS) composed of polyethylene glycols of different molecular weights (PEG 400, 600 and 1000) and buffered aqueous solutions of potassium citrate/citric acid (pH = 5.0 - 8.0) to selectively extract ovalbumin from egg white was here investigated. Phase diagrams, tie-lines and tie-line lengths were determined at 25ºC and the partitioning of ovalbumin in these systems was then evaluated. Aiming at optimizing the selective extraction of ovalbumin in the studied ABS, factors such as pH, PEG molecular weight and amount of the phase-forming components were initially investigated with pure commercial ovalbumin. In almost all ABS, it was observed a preferential partitioning of ovalbumin to the polymer-rich phase, with extraction efficiencies higher than 90%. The best ABS were then applied in the purification of ovalbumin from the real egg white matrix. In order to ascertain on the ovalbumin purity and yield, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion high performance liquid chromatography (SE-HPLC) analyses were conducted, confirming that the isolation/purification of ovalbumin from egg white was completely achieved in a single-step with a recovery yield of 65%. The results obtained show that polymer-salt-based ABS allow the selective extraction of ovalbumin from egg white with a simpler approach and better performance than previously reported. Finally, it is shown that ovalbumin can be completely recovered from the PEG-rich phase by an induced precipitation using an inexpensive and sustainable separation platform which can be easily applied on an industrial scale.

  20. Direct transformation of xylan-type hemicelluloses to furfural via SnCl₄ catalysts in aqueous and biphasic systems.

    PubMed

    Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

    2015-05-01

    Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120 min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Cell surface energy, contact angles and phase partition. II. Bacterial cells in biphasic aqueous mixtures.

    PubMed

    Gerson, D F; Akit, J

    1980-11-04

    Partition coefficients in biphasic mixtures of poly(ethylene glycol) and Dextran are compared to cell surface energies obtained from contact angles of each liquid phase on cell layers. Linear relationships are observed between these two independent measurements for a variety of bacterial cells. The results demonstrate the importance of interfacial phenomena and contact angles in the phase-partition process.

  2. Simple, benign, aqueous-based amination of polycarbonate surfaces

    DOE PAGES

    VanDelinder, Virginia; Wheeler, David R.; Small, Leo J.; ...

    2015-03-18

    Here we report a simple, safe, environmentally-friendly aqueous method that uses diamines to functionalize a polycarbonate surface with amino groups. We demonstrate the ability of this facile method to serve as a foundation upon which other functionalities may be attached, including anti-fouling coatings and oriented membrane proteins. The use of water as the solvent for the functionalization ensures that solvent induced swelling does not affect the optical or mechanical properties of the polycarbonate.

  3. Separation of no-carrier-added rhenium from bulk tantalum by the sodium malonate-PEG aqueous biphasic system.

    PubMed

    Dutta, Binita; Lahiri, Susanta; Tomar, B S

    2014-02-01

    The aqueous biphasic system (ABS) involving sodium malonate-polyethylene glycol (PEG) phases has been applied for the first time for separation of no-carrier-added (183)Re (T1/2=70 d) from α-particle irradiated bulk tantalum target. The various ABS conditions were applied for investigating the separation by varying pH, temperature, PEG-molecular weight, concentration of salt. The extraction pattern was hardly affected by change in pH and the molecular weight of PEG. One step separation of nca (183)Re from Ta was achieved at the optimal conditions of (i) 50% (w/w) PEG-4000-2 M sodium malonate, 40 °C and (ii) 50% (w/w) PEG-4000-3 M sodium malonate, room temperature (27 °C). © 2013 Published by Elsevier Ltd.

  4. Simple, benign, aqueous-based amination of polycarbonate surfaces.

    PubMed

    VanDelinder, Virginia; Wheeler, David R; Small, Leo J; Brumbach, Michael T; Spoerke, Erik D; Henderson, Ian; Bachand, George D

    2015-03-18

    Polycarbonate is a desirable material for many applications due to its favorable mechanical and optical properties. Here, we report a simple, safe, environmentally friendly aqueous method that uses diamines to functionalize a polycarbonate surface with amino groups. The use of water as the solvent for the functionalization ensures that solvent induced swelling does not affect the optical or mechanical properties of the polycarbonate. We characterize the efficacy of the surface amination using X-ray photo spectroscopy, Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and contact angle measurements. Furthermore, we demonstrate the ability of this facile method to serve as a foundation upon which other functionalities may be attached, including antifouling coatings and oriented membrane proteins.

  5. Enhanced extraction of bovine serum albumin with aqueous biphasic systems of phosphonium- and ammonium-based ionic liquids

    PubMed Central

    Pereira, Matheus M.; Pedro, Sónia N.; Quental, Maria V.; Lima, Álvaro S.; Coutinho, João A. P.; Freire, Mara G.

    2016-01-01

    Novel aqueous biphasic systems (ABS) composed of phosphonium- or ammonium-based ionic liquids (ILs), combined with a buffered aqueous solution of potassium citrate/citric acid (pH=7.0), were investigated for the extraction of proteins. For that purpose, the phase diagrams, tie-lines and tie-line lengths were determined at 25ºC, and the performance of these ABS for the extraction of bovine serum albumin (BSA) was then evaluated. The obtained results reveal that, with the exception of the more hydrophobic ILs, most of the systems investigated allow the complete extraction of BSA for the IL-rich phase in a single-step. These remarkable extraction efficiencies are far superior to those afforded by more conventional extraction systems previously reported. The composition of the biphasic systems, i.e., the amount of phase-forming components, was also investigated aiming at reducing the overall costs of the process without losing efficiency on the protein extraction. It is shown that the extraction efficiencies of BSA are maintained at 100% up to high protein concentrations (at least up to 10 g.L-1). The recovery of the BSA from the IL-rich phase by dialysis is also shown in addition to the demonstration of the IL recyclability and reusability, at least for 3 times. In the sequential three-step extractions (BSA recovery/IL reusability), the extraction efficiencies of BSA for the IL-rich phase were maintained at 100%. For the improved ABS, the preservation of the protein native conformation was confirmed by Size Exclusion High-Performance Liquid Chromatography (used also as the quantification method) and by Fourier Transform Infra-Red spectroscopy. According to the results herein reported, ABS composed of phosphonium- or ammonium-based ILs and a biodegradable organic salt represent an alternative and remarkable platform for the extraction of BSA and may be extended to other proteins of interest. PMID:25865275

  6. Enhanced extraction of bovine serum albumin with aqueous biphasic systems of phosphonium- and ammonium-based ionic liquids.

    PubMed

    Pereira, Matheus M; Pedro, Sónia N; Quental, Maria V; Lima, Álvaro S; Coutinho, João A P; Freire, Mara G

    2015-07-20

    Novel aqueous biphasic systems (ABS) composed of phosphonium- or ammonium-based ionic liquids (ILs), combined with a buffered aqueous solution of potassium citrate/citric acid (pH=7.0), were investigated for the extraction of proteins. For that purpose, the phase diagrams, tie-lines and tie-line lengths were determined at 25 °C, and the performance of these ABS for the extraction of bovine serum albumin (BSA) was then evaluated. The obtained results reveal that, with the exception of the more hydrophobic ILs, most of the systems investigated allow the complete extraction of BSA for the IL-rich phase in a single-step. These remarkable extraction efficiencies are far superior to those afforded by more conventional extraction systems previously reported. The composition of the biphasic systems, i.e., the amount of phase-forming components, was also investigated aiming at reducing the overall costs of the process without losing efficiency on the protein extraction. It is shown that the extraction efficiencies of BSA are maintained at 100% up to high protein concentrations (at least up to 10 g L(-1)). The recovery of the BSA from the IL-rich phase by dialysis is also shown in addition to the demonstration of the IL recyclability and reusability, at least for 3 times. In the sequential three-step extractions (BSA recovery/IL reusability), the extraction efficiencies of BSA for the IL-rich phase were maintained at 100%. For the improved ABS, the preservation of the protein native conformation was confirmed by Size Exclusion High-Performance Liquid Chromatography (used also as the quantification method) and by Fourier Transform Infra-Red spectroscopy. According to the results herein reported, ABS composed of phosphonium- or ammonium-based ILs and a biodegradable organic salt represent an alternative and remarkable platform for the extraction of BSA and may be extended to other proteins of interest.

  7. Selection of xenobiotic-degrading microorganisms in a biphasic aqueous-organic system

    SciTech Connect

    Ascon-Cabrera, M.; Lebeault, J.M. )

    1993-06-01

    The selection of microorganisms able to grow on xenobiotic compounds is the first problem to solve in the biodegradation process. While many genera of microorganisms which use xenobiotic compounds as growth substrates have been isolated, attempts to isolate strains in the presence of a specific xenobiotic are no always sucessful. This paper describes the performance of a biphasic water-silicone oil system for selection of microorganisms in the presence of two industrial mixtures: (1) 1,2-dichlorobenzene and 1,2,3- and 1,2,4-trichlorobenzenes and (2) ethyl butyrate, 2-ethylbutyraldehyde, butyraldehyde, ethyl acetate, and ethanol. Factors responsible for improvement of xenobiotic compound degradation in this system and possible applications in biodegradation processes are discussed. 33 refs., 6 figs., 3 tabs.

  8. Aqueous biphasic systems composed of ionic liquids and polypropylene glycol: insights into their liquid–liquid demixing mechanisms†

    PubMed Central

    Lemus, Jesus; Pereira, Jorge F. B.; Freire, Mara G.; Coutinho, João A. P.

    2016-01-01

    Novel ternary phase diagrams of aqueous biphasic systems (ABSs) composed of polypropylene glycol with an average molecular weight of 400 g mol−1 (PPG-400) and a vast number of ionic liquids (ILs) were determined. The large array of selected ILs allowed us to evaluate their tuneable structural features, namely the effect of the anion nature, cation core and cation alkyl side chain length on the phase behaviour. Additional evidence on the molecular-level mechanisms which rule the phase splitting was obtained by 1H NMR (Nuclear Magnetic Resonance) spectroscopy and by COSMO-RS (Conductor-like Screening Model for Real Solvents). Some systems, for which the IL–PPG-400 pairs are completely miscible, revealed to be of type “0”. All data collected suggest that the formation of PPG–IL-based ABSs is controlled by the interactions established between the IL and PPG, contrarily to previous reports where a “salting-out” phenomenon exerted by the IL over the polymer in aqueous media was proposed as the dominant effect in ABS formation. The influence of temperature on the liquid–liquid demixing was also evaluated. In general, an increase in temperature favours the formation of an ABS in agreement with the lower critical solution temperature (LCST) phase behaviour usually observed in polymer–IL binary mixtures. Partition results of a dye (chloroanilic acid, in its neutral form) further confirm the possibility of tailoring the phases’ polarities of IL–PPG-based ABSs. PMID:27405841

  9. Aqueous biphasic systems composed of ionic liquids and acetate-based salts: phase diagrams, densities and viscosities.

    PubMed

    Quental, Maria V; Passos, Helena; Kurnia, Kiki A; Coutinho, João A P; Freire, Mara G

    2015-06-11

    Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have been largely investigated as promising extraction and purification routes. In this context, the determination of their phase diagrams and the physical properties of the coexisting phases are of high relevance when envisaging their large-scale applications. Low viscosities improve the mass transfer and reduce energy consumptions, while the knowledge on their densities is important for the equipment design. In this work, novel phase diagrams for aqueous solutions of imidazolium-based ILs combined with acetate-based salts, namely KCH3CO2 or NaCH3CO2, are reported and discussed. The ability of the acetate-based salts to induce the phase separation not only depends on the ions hydration energy, but also on the concentration of "free" ions in solution. The tie-lines, tie-line lengths and critical points are also addressed. Experimental measurements of density and viscosity of the coexisting phases, for the different systems and at several compositions and temperatures, are additionally presented. The Othmer-Tobias and Bancroft equations are also applied to ascertain on the tie-lines coherence. It is here shown that low-viscous IL-based ABS, with a high difference in the densities of the coexisting phases, can be formed with organic and biodegradable salts thus offering enhanced features over conventional polymer-based systems.

  10. Aqueous biphasic systems composed of ionic liquids and acetate-based salts: phase diagrams, densities and viscosities

    PubMed Central

    Quental, Maria V.; Passos, Helena; Kurnia, Kiki A.; Coutinho, João A. P.; Freire, Mara G.

    2017-01-01

    Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have been largely investigated as promising extraction and purification routes. In this context, the determination of their phase diagrams and the physical properties of the coexisting phases are of high relevance when envisaging their large-scale applications. Low viscosities improve the mass transfer and reduce energy consumptions, while the knowledge on their densities is important for the equipment design. In this work, novel phase diagrams for aqueous solutions of imidazolium-based ILs combined with acetate-based salts, namely KCH3CO2 or NaCH3CO2, are reported and discussed. The ability of the acetate-based salts to induce the phase separation not only depends on the ions hydration energy, but also on the concentration of “free” ions in solution. The tie-lines, tie-line lengths and critical points are also addressed. Experimental measurements of density and viscosity of the coexisting phases, for the different systems and at several compositions and temperatures, are additionally presented. The Othmer–Tobias and Bancroft equations are also applied to ascertain on the tie-lines coherence. It is here shown that low-viscous IL-based ABS, with a high difference in the densities of the coexisting phases, can be formed with organic and biodegradable salts thus offering enhanced features over conventional polymer-based systems. PMID:28260810

  11. Evaluation of the Capability of Ionic Liquid-Amino Acid Aqueous Systems for the Formation of Aqueous Biphasic Systems and Their Applications in Extraction.

    PubMed

    Noshadi, Sajjad; Sadeghi, Rahmat

    2017-03-03

    In order to obtain further experimental evidence for better understanding of the molecular mechanisms responsible for the soluting-out effect phenomena in the ternary systems composed of ionic liquid (IL), amino acid and water, systematic studies on the vapor-liquid, liquid-liquid and solid-liquid equilibrium behavior of aqueous solutions of several ILs were carried out in the presence of a range of amino acids. Water activities for binary and ternary aqueous solutions containing 1-butyl-3-methylimidazolium chloride, [C4mim]Cl, 1-hexyl-3-methylimidazolium chloride, [C6mim]Cl, 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate, [C4mim][CF3SO3], l-serine, glycine, alanine, and l-proline were measured using both vapor pressure osmometry and isopiestic methods. All the ternary IL + amino acid + water systems show the negative deviations from the semi-ideal behavior and therefore the soluting-out effects have been seen in these systems. In the case of [C4mim][CF3SO3] + amino acids aqueous systems, the IL is soluted-out by the amino acids and the soluting-out effect appears by aqueous biphasic systems formation. For these systems, the phase diagram and partition coefficient of caffeine were measured at 298.15 K. However, for the [C4mim]Cl and [C6mim]Cl containing systems, the amino acids are soluted-out by the ILs and the soluting-out effect appears by precipitation of the amino acids from the solution and solubilities of the amino acids in aqueous solutions decrease in the presence of [C4mim]Cl and [C6mim]Cl.

  12. Salt Effect Model for Aqueous Solubility of TBP in a 5 to 100% TBP/n-Dodecane-Nitric Acid-Water Biphasic System at 298.2 K

    SciTech Connect

    Kumar, Shekhar; Koganti, Sudhir Babu

    2000-02-15

    The solubilities of nonelectrolytes in aqueous electrolyte solutions have traditionally been modeled by using the Setschenow equation for salt effect. The aqueous solubility of tri-n-butyl phosphate (TBP) during operating conditions of the Purex process is an important parameter for safety considerations. Use of the Setschenow equation for aqueous solubility of TBP under limited conditions has been reported in the literature. However, there is no general model available to account for the presence of the diluent and for the case of multicomponent electrolyte solutions in which only some electrolytes are solvated and extracted by TBP. An extended salt effect model is proposed for predicting the aqueous solubility of TBP in a 5 to 100% TBP/n-dodecane-nitric acid-water biphasic system at 298.2 K. The literature data on TBP solubility were correlated to aqueous acid concentration, diluent concentration in the solvents, and an interaction parameter for electrolytic solutes (extracted or not extracted by TBP)

  13. Evidence for the interactions occurring between ionic liquids and tetraethylene glycol in binary mixtures and aqueous biphasic systems.

    PubMed

    Tomé, Luciana I N; Pereira, Jorge F B; Rogers, Robin D; Freire, Mara G; Gomes, José R B; Coutinho, João A P

    2014-05-01

    The well-recognized advantageous properties of poly(ethylene glycol)s (PEGs) and ionic liquids (ILs) in the context of an increasing demand for safe and efficient biotechnological processes has led to a growing interest in the study of their combinations for a wide range of procedures within the framework of green chemistry. Recently, one of the most promising and attractive applications has been the novel IL/polymer-based aqueous biphasic systems (ABS) for the extraction and purification of biomolecules. There still lacks, however, a comprehensive picture of the molecular phenomena that control the phase behavior of these systems. In order to further delve into the interactions that govern the mutual solubilities between ILs and PEGs and the formation of PEG/IL-based ABS, (1)H NMR spectroscopy in combination with classical molecular dynamics (MD) simulations performed for binary mixtures of tetraethylene glycol (TEG) and 1-alkyl-3-methylimidazolium-chloride-based ILs and for the corresponding ternary TEG/IL/water solutions, at T = 298.15 K, were employed in this work. The results of the simulations show that the mutual solubilities of the ILs and TEG are mainly governed by the hydrogen bonds established between the chloride anion and the -OH group of the polymer in the binary systems. Additionally, the formation of IL/PEG-based ABS is shown to be controlled by a competition between water and chloride for the interactions with the hydroxyl group of TEG.

  14. Improving the extraction and purification of immunoglobulin G by the use of ionic liquids as adjuvants in aqueous biphasic systems.

    PubMed

    Ferreira, Ana M; Faustino, Vânia F M; Mondal, Dibyendu; Coutinho, João A P; Freire, Mara G

    2016-10-20

    Immunoglobulins G (IgG) could become widespread biopharmaceuticals if cost-efficient processes for their extraction and purification are available. In this work, aqueous biphasic systems (ABS) composed of polyethylene glycols and a buffered salt, and with ionic liquids (ILs) as adjuvants, have been studied as alternative extraction and purification platforms of IgG from a rabbit serum source. Eleven ILs were investigated to provide insights on the chemical features which maximize the IgG partitioning. It is shown that in polymer-salt systems pure IgG preferentially partitions to the polymer-rich phase; yet, the complete extraction was never attained. Remarkably, after the addition of 5wt% of adequate ILs to polymer-salt ABS, the complete extraction of pure IgG in a single-step was accomplished. The best systems and conditions were then applied to the extraction and purification of IgG directly from rabbit serum samples. The complete extraction of IgG in a single-step was maintained while its purity in the polymer-rich phase was enhanced by ca. 37% as compared to the IL-free ABS. The antibody stability was also evaluated revealing that appropriate ILs are able to maintain the IgG stability and can be used as phase-forming components of ABS when envisaging the purification of high-cost biopharmaceuticals.

  15. Enhanced extraction of proteins using cholinium-based ionic liquids as phase-forming components of aqueous biphasic systems.

    PubMed

    Quental, Maria V; Caban, Magda; Pereira, Matheus M; Stepnowski, Piotr; Coutinho, João A P; Freire, Mara G

    2015-09-01

    Aqueous biphasic systems (ABS) composed of ionic liquids (ILs) are promising platforms for the extraction and purification of proteins. In this work, a series of alternative and biocompatible ABS composed of cholinium-based ILs and polypropylene glycol were investigated. The respective ternary phase diagrams, tie-lines, tie-line lengths and critical points were determined at 25°C. The extraction performance of these systems for commercial bovine serum albumin (BSA) was then evaluated. The stability of BSA at the IL-rich phase was ascertained by size exclusion high-performance liquid chromatography and Fourier transform infrared spectroscopy. Appropriate ILs lead to the complete extraction of BSA for the IL-rich phase, in a single step, while maintaining the protein's native conformation. Furthermore, to evaluate the performance of these systems when applied to real matrices, the extraction of BSA from bovine serum was additionally carried out, revealing that the complete extraction of BSA was maintained and achieved in a single step. The remarkable extraction efficiencies obtained are far superior to those observed with typical polymer-based ABS. Therefore, the proposed ABS may be envisaged as a more effective and biocompatible approach for the separation and purification of other value-added proteins.

  16. A critical assessment of the mechanisms governing the formation of aqueous biphasic systems composed of protic ionic liquids and polyethylene glycol†

    PubMed Central

    Cláudio, Ana Filipa M.; Pereira, Jorge F. B.; McCrary, Parker D.; Freire, Mara G.; Coutinho, João A. P.; Rogers, Robin D.

    2017-01-01

    An extensive study on the formation of aqueous biphasic systems (ABS) using aqueous solutions of protic ionic liquids (PILs) and polyethylene glycol (PEG) was performed in order to understand the mechanisms underlying the phase separation. Aqueous solutions of PEG polymers with different molecular weights (600, 1000, 2000, and 3400 g mol−1) and several N-alkyl-, dialkyl-, and trialkyl-ammonium salts of acetate, propanoate, butanoate, hexanoate and octanoate were prepared and their ability to form ABS at several temperatures assessed. The ternary liquid–liquid phase diagrams were determined at several temperatures, as well as binary PIL (or salt)-PEG-1000 and salt-water solubility data to better clarify the mechanisms responsible for the phase separation. All data gathered indicate that the formation of PEG–PIL-based ABS is mainly governed by the PIL–PEG mutual interactions, where PILs with a higher solubility in the polymer exhibit a lower aptitude to form ABS displaying thus a smaller biphasic region, for which a direct correlation was identified. The effects of the molecular weight and temperature of the polymer were also addressed. The increase of the PEG hydrophobicity or molecular weight favours the phase separation, whereas the effect of temperature was found to be more complex and dependent on the nature of the PIL, with an increase or decrease of the biphasic regime with an increase in temperature. PMID:27774550

  17. Drop Migration and Demixing of Biphasic Aqueous Systems in an Applied Electric Field

    NASA Astrophysics Data System (ADS)

    Todd, Paul; Raghavarao, Karumanchi S. M. S.

    1999-11-01

    Applying an electric field to a demixing emulsion of poly(ethylene glycol)(PEG) and dextran (or maltodextrin) in phosphate-buffered aqueous solution shortens the demixing time up to 6 fold. Phosphate ions partition into the dextran-rich phase imparting a small electrical potential between the phases. PEG-rich drops migrate cathodally, and their electrophoretic mobility is directly proportional to their radius and increases with increased ionization of phosphate. An electric field, either parallel or antiparallel to the gravity vector, can enhance demixing. A theory consistent with these observations states that drops move due to external and internal electroosmotic flow (tractor treading). Enhanced demixing in an electric field whose polarity opposes buoyancy is thought to be caused by initial increased drop growth during retardation by the electric field so that the drop becomes more buoyant. However, at infinite internal drop viscosity the theory does not extrapolate to the result for solid colloid particles.

  18. 15α-Hydroxylation of a steroid (13-ethyl-gon-4-en-3,17-dione) by Penicillium raistrickii in an ionic liquid/aqueous biphasic system.

    PubMed

    Mao, Shuhong; Hu, Xiaojie; Hua, Boyuan; Wang, Na; Liu, Xiaoguang; Lu, Fuping

    2012-11-01

    Biphasic processes are used in whole-cell biotransformation to overcome the low water solubility of substrates and products as well as their inhibitory effects on the biocatalyst. Commercially available [NTf(2)]- and [PF(6)]-based ionic liquids (ILs) were used in a biphasic system for the 15α-hydroxylation of 13-ethyl-gon-4-en-3,17-dione by Penicillium raistrickii. With the substrate at 5 g l(-1) and a volume ratio of IL to buffer, buffer pH and cell density at, 1:9, 6.5, 16.8 g(DW) l(-1), respectively, the 15α-hydroxylation of 13-ethyl-gon-4-en-3,17-dione was achieved with a yield of 70 % after 72 h using [BMIm][NTf(2)] in a 50 ml biphasic system. This is compared to a 30 % yield in a monophasic aqueous system. This suggests the potential industrial application of ILs-based biphasic systems for steroid biotransformation.

  19. Colocalization and Sequential Enzyme Activity in Aqueous Biphasic Systems: Experiments and Modeling

    PubMed Central

    Davis, Bradley W.; Aumiller, William M.; Hashemian, Negar; An, Songon; Armaou, Antonios; Keating, Christine D.

    2015-01-01

    Subcellular compartmentalization of biomolecules and their reactions is common in biology and provides a general strategy for improving and/or controlling kinetics in metabolic pathways that contain multiple sequential enzymes. Enzymes can be colocalized in multiprotein complexes, on scaffolds or inside subcellular organelles. Liquid organelles formed by intracellular phase coexistence could provide an additional means of sequential enzyme colocalization. Here we use experiment and computation to explore the kinetic consequences of sequential enzyme compartmentalization into model liquid organelles in a crowded polymer solution. Two proteins of the de novo purine biosynthesis pathway, ASL (adenylosuccinate lyase, Step 8) and ATIC (5-aminoimidazole-4-carboxamide ribonucleotide transformylase/inosine monophosphate cyclohydrolase, Steps 9 and 10), were studied in a polyethylene glycol/dextran aqueous two-phase system. Dextran-rich phase droplets served as model liquid compartments for enzyme colocalization. In this system, which lacks any specific binding interactions between the phase-forming polymers and the enzymes, we did not observe significant rate enhancements from colocalization for the overall reaction under our experimental conditions. The experimental results were used to adapt a mathematical model to quantitatively describe the kinetics. The mathematical model was then used to explore additional, experimentally inaccessible conditions to predict when increased local concentrations of enzymes and substrates can (or cannot) be expected to yield increased rates of product formation. Our findings indicate that colocalization within these simplified model liquid organelles can lead to enhanced metabolic rates under some conditions, but that very strong partitioning into the phase that serves as the compartment is necessary. In vivo, this could be provided by specific binding affinities between components of the liquid compartment and the molecules to be

  20. Aqueous biphasic systems containing PEG-based deep eutectic solvents for high-performance partitioning of RNA.

    PubMed

    Zhang, Hongmei; Wang, Yuzhi; Zhou, Yigang; Xu, Kaijia; Li, Na; Wen, Qian; Yang, Qin

    2017-08-01

    In this work, 16 kinds of novel deep eutectic solvents (DESs) composed of polyethylene glycol (PEG) and quaternary ammonium salts, were coupled with Aqueous Biphasic Systems (ABSs) to extract RNA. The phase forming ability of ABSs were comprehensively evaluated, involving the effects of various proportions of DESs' components, carbon chain length and anions species of quaternary ammonium salts, average molecular weights of PEG and inorganic salts nature. Then the systems were applied in RNA extraction, and the results revealed that the extraction efficiency values were distinctly enhanced by relatively lower PEG content in DESs, smaller PEG molecular weights, longer carbon chain of quaternary ammonium salts and more hydrophobic inorganic salts. Then the systems composed of [TBAB][PEG600] and Na2SO4 were utilized in the influence factor experiments, proving that the electrostatic interaction was the dominant force for RNA extraction. Therefore, back-extraction efficiency values ranging between 85.19% and 90.78% were obtained by adjusting the ionic strength. Besides, the selective separation of RNA and tryptophane (Trp) was successfully accomplished. It was found that 86.19% RNA was distributed in the bottom phase, while 72.02% Trp was enriched in the top phase in the novel ABSs. Finally, dynamic light scattering (DLS) and transmission electron microscope (TEM) were used to further investigate the extraction mechanism. The proposed method reveals the outstanding feasibility of the newly developed ABSs formed by PEG-based DESs and inorganic salts for the green extraction of RNA. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. One-step extraction and concentration of estrogens for an adequate monitoring of wastewater using ionic-liquid-based aqueous biphasic systems†

    PubMed Central

    Lima, Diana L. D.; Esteves, Valdemar I.; Coutinho, João A. P.; Freire, Mara G.

    2015-01-01

    Ethinylestradiol (EE2) is a synthetic hormone that has been recognized as one of the most prominent endocrine disruptors found in the aqueous environment. Nevertheless, the low content of EE2 in wastewater makes its identification/quantification unfeasible – a major drawback for the evaluation of its persistence and environmental impact. In this context, a novel extraction/concentration method for EE2 from wastewater is proposed here based on aqueous biphasic systems composed of ionic liquids (ILs). Aqueous biphasic systems formed by several hydrophilic ILs and KNaC4H4O6 were initially screened and optimized, with extraction efficiencies of EE2 for the IL-rich phase ranging between 92 and 100%. Remarkable results were obtained with systems that allow the complete extraction of EE2 in a single-step, and without loss of EE2 or the saturation of the extractive phase. Further, the concentration factors of EE2 attainable with these systems were investigated by a suitable manipulation of the composition of the phase-forming components and the corresponding volumes of the coexisting phases. An outstanding concentration of EE2 up to 1000-fold (from ng L−1 to μg L−1) in a single extraction and concentration step was achieved for the first time with IL-based aqueous biphasic systems. These systems are straightforwardly envisaged for the monitoring of wastewater as one-step extraction and concentration routes for a wide array of endocrine disrupting chemicals while allowing an adequate evaluation of their environmental impact. PMID:26379470

  2. One-step extraction and concentration of estrogens for an adequate monitoring of wastewater using ionic-liquid-based aqueous biphasic systems.

    PubMed

    Dinis, Teresa B V; Passos, Helena; Lima, Diana L D; Esteves, Valdemar I; Coutinho, João A P; Freire, Mara G

    2015-04-01

    Ethinylestradiol (EE2) is a synthetic hormone that has been recognized as one of the most prominent endocrine disruptors found in the aqueous environment. Nevertheless, the low content of EE2 in wastewater makes its identification/quantification unfeasible - a major drawback for the evaluation of its persistence and environmental impact. In this context, a novel extraction/concentration method for EE2 from wastewater is proposed here based on aqueous biphasic systems composed of ionic liquids (ILs). Aqueous biphasic systems formed by several hydrophilic ILs and KNaC4H4O6 were initially screened and optimized, with extraction efficiencies of EE2 for the IL-rich phase ranging between 92 and 100%. Remarkable results were obtained with systems that allow the complete extraction of EE2 in a single-step, and without loss of EE2 or the saturation of the extractive phase. Further, the concentration factors of EE2 attainable with these systems were investigated by a suitable manipulation of the composition of the phase-forming components and the corresponding volumes of the coexisting phases. An outstanding concentration of EE2 up to 1000-fold (from ng L(-1) to μg L(-1)) in a single extraction and concentration step was achieved for the first time with IL-based aqueous biphasic systems. These systems are straightforwardly envisaged for the monitoring of wastewater as one-step extraction and concentration routes for a wide array of endocrine disrupting chemicals while allowing an adequate evaluation of their environmental impact.

  3. Controlling the Formation of Ionic-Liquid-based Aqueous Biphasic Systems by Changing the Hydrogen-Bonding Ability of Polyethylene Glycol End Groups.

    PubMed

    Pereira, Jorge F B; Kurnia, Kiki A; Freire, Mara G; Coutinho, João A P; Rogers, Robin D

    2015-07-20

    The formation of aqueous biphasic systems (ABS) when mixing aqueous solutions of polyethylene glycol (PEG) and an ionic liquid (IL) can be controlled by modifying the hydrogen-bond-donating/-accepting ability of the polymer end groups. It is shown that the miscibility/immiscibility in these systems stems from both the solvation of the ether groups in the oxygen chain and the ability of the PEG terminal groups to preferably hydrogen bond with water or the anion of the salt. The removal of even one hydrogen bond in PEG can noticeably affect the phase behavior, especially in the region of the phase diagram in which all the ethylene oxide (EO) units of the polymeric chain are completely solvated. In this region, removing or weakening the hydrogen-bond-donating ability of PEG results in greater immiscibility, and thus, in a higher ability to form ABS, as a result of the much weaker interactions between the IL anion and the PEG end groups.

  4. Extraction, Preconcentration and Isolation of Flavonoids from Apocynum venetum L. Leaves Using Ionic Liquid-Based Ultrasonic-Assisted Extraction Coupled with an Aqueous Biphasic System.

    PubMed

    Tan, Zhijian; Yi, Yongjian; Wang, Hongying; Zhou, Wanlai; Wang, Chaoyun

    2016-03-04

    Ionic liquids (ILs) are considered as green solvents, and widely applied for the extraction of various compounds. The present research focuses on the extraction of flavonoids from Apocynum venetum L. leaves by ultrasound-assisted extraction (UAE). Several major influencing factors were optimized. Then, an aqueous biphasic system (ABS) was applied for further isolation of flavonoids. The flavonoids were mainly distributed in the top phase, while impurities were extracted to the bottom phase. The parameters influencing the extraction, namely type and concentration of salt, temperature, and pH, were studied in detail. Under optimized conditions (72.43% IL extract, 28.57% (NH4)2SO4, 25 °C temperature, pH 4.5), the preconcentration factor and extraction efficiency were found to be 3.78% and 93.35%, respectively. This simple and efficient methodology is expected to see great use in the extraction and isolation of pharmaceutically active components from medicinal plant resources.

  5. Evaluation of a hydrophilic ionic liquid as a salting-out phase separation agent to a water-tetrahydrofuran homogeneous system for aqueous biphasic extraction separation.

    PubMed

    Hirayama, Naoki; Higo, Takaaki; Imura, Hisanori

    2012-01-01

    The use of a hydrophilic ionic liquid (IL), 1-butyl-3-methylimidazolium chloride (C(4)mimCl), as a salting-out phase separation agent to a water-tetrahydrofuran homogeneous system was studied for possible applications to novel aqueous biphasic extraction separation. The IL showed a salting-out phase-separation ability. Also, differences in the polarity between the formed two phases were smaller than that when using NaCl as a salting-out agent. This result suggested that C(4)mimCl remaining in water-rich phase acts not only as a salting-out agent, but also a component of a mixed-solvent. Possible uses of C(4)mimCl/NaCl mixed salting-out agent system were also discussed.

  6. Liquid-Phase Synthesis of Ba2V2O7 Phosphor Powders and Films Using Immiscible Biphasic Organic-Aqueous Systems.

    PubMed

    Takahashi, Mami; Hagiwara, Manabu; Fujihara, Shinobu

    2016-08-15

    A liquid-phase synthesis of inorganic phosphor materials at a moderate temperature was proposed by using immiscible liquid-liquid biphasic systems. A self-activated Ba2V2O7 phosphor was actually synthesized from vanadium alkoxide dissolved in an organic solution and barium acetate in an aqueous solution. A mild hydrolysis reaction of the alkoxide started at the organic-inorganic interface, and an intermediate compound, Ba(VO3)2·H2O, was initially formed. Ba2V2O7 powders were then obtained by the conversion from Ba(VO3)2·H2O promoted in the aqueous solution. Ba2V2O7 films were obtained on surface-modified silica glass substrates through the similar chemical reactions. Factors such as the surface state of substrates, the kind of organic solvents, and the volume of aqueous solutions were examined to improve the film deposition behavior. The resultant Ba2V2O7 materials showed broad-band visible photoluminescence upon irradiation with ultraviolet light based on the charge transfer transition in the VO4(3-) units existing as dimers.

  7. Diffusion-regulated phase-transfer catalysis for atom transfer radical polymerization of methyl methacrylate in an aqueous/organic biphasic system.

    PubMed

    Ding, Mingqiang; Jiang, Xiaowu; Peng, Jinying; Zhang, Lifen; Cheng, Zhenping; Zhu, Xiulin

    2015-03-01

    A concept based on diffusion-regulated phase-transfer catalysis (DRPTC) in an aqueous-organic biphasic system with copper-mediated initiators for continuous activator regeneration is successfully developed for atom transfer radical polymerization (ICAR ATRP) (termed DRPTC-based ICAR ATRP here), using methyl methacrylate (MMA) as a model monomer, ethyl α-bromophenylacetate (EBrPA) as an initiator, and tris(2-pyridylmethyl)amine (TPMA) as a ligand. In this system, the monomer and initiating species in toluene (organic phase) and the catalyst complexes in water (aqueous phase) are simply mixed under stirring at room temperature. The trace catalyst complexes transfer into the organic phase via diffusion to trigger ICAR ATRP of MMA with ppm level catalyst content once the system is heated to the polymerization temperature (75 °C). It is found that well-defined PMMA with controlled molecular weights and narrow molecular weight distributions can be obtained easily. Furthermore, the polymerization can be conducted in the presence of limited amounts of air without using tedious degassed procedures. After cooling to room temperature, the upper organic phase is decanted and the lower aqueous phase is reused for another 10 recycling turnovers with ultra low loss of catalyst and ligand loading. At the same time, all the recycled catalyst complexes retain nearly perfect catalytic activity and controllability, indicating a facile and economical strategy for catalyst removal and recycling. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Aqueous Biphasic Systems for the Synthesis of Formates by Catalytic CO2 Hydrogenation: Integrated Reaction and Catalyst Separation for CO2 -Scrubbing Solutions.

    PubMed

    Scott, Martin; Blas Molinos, Beatriz; Westhues, Christian; Franciò, Giancarlo; Leitner, Walter

    2017-03-22

    Aqueous biphasic systems were investigated for the production of formate-amine adducts by metal-catalyzed CO2 hydrogenation, including typical scrubbing solutions as feedstocks. Different hydrophobic organic solvents and ionic liquids could be employed as the stationary phase for cis-[Ru(dppm)2 Cl2 ] (dppm=bis-diphenylphosphinomethane) as prototypical catalyst without any modification or tagging of the complex. The amines were found to partition between the two phases depending on their structure, whereas the formate-amine adducts were nearly quantitatively extracted into the aqueous phase, providing a favorable phase behavior for the envisaged integrated reaction/separation sequence. The solvent pair of methyl isobutyl carbinol (MIBC) and water led to the most practical and productive system and repeated use of the catalyst phase was demonstrated. The highest single batch activity with a TOFav of approximately 35 000 h(-1) and an initial TOF of approximately 180 000 h(-1) was achieved in the presence of NEt3 . Owing to higher stability, the highest productivities were obtained with methyl diethanolamine (Aminosol CST 115) and monoethanolamine (MEA), which are used in commercial scale CO2 -scrubbing processes. Saturated aqueous solutions (CO2 overpressure 5-10 bar) of MEA could be converted into the corresponding formate adducts with average turnover frequencies up to 14×10(3)  h(-1) with an overall yield of 70 % based on the amine, corresponding to a total turnover number of 150 000 over eleven recycling experiments. This opens the possibility for integrated approaches to carbon capture and utilization.

  9. Alternative (Potentially Green) Separations Media: Aqueous Biphasic and Related Systems Extending the Frontier Final Report For Period September 1, 2002 January 31, 2007

    SciTech Connect

    Rogers, Robin D

    2007-06-25

    Through the current DoE-BES funding, we have extended our fundamental understanding of the critical phase separation of aqueous polymer solutions at the molecular level, and have developed a similar understanding of their application as novel solvent systems. Our principal aims included mode of delivery of the aqueous biphasic system (ABS) solvent system and the application of this system to problems of reactive extraction. In the former case we have developed novel solid phase analogues, in the form of cross-linked polyethylene glycol hydrogels, and in the latter case we have examined the role that ABS might play in reaction engineering, with a view to greener, simpler, and safer processes. We have also developed a new salt/salt ABS and have extended our understanding of this system as well. The major outcomes are as follows: (1) Through the use of variable temperature phase diagrams, coupled with differential scanning calorimetry (DSC) measurements of the phases, a better understanding of the thermodynamics of phase formation was obtained. Evidence to the existence and role of an upper critical solution temperature (UCST) or lower critical solution temperature (LCST) (or both) in these systems was gained. With variable temperature solute partitioning, thermodynamic parameters were calculated, and inter-system comparisons were made. Through the use of Abraham's linear solvation energy regression (LSER) the solvent-solute properties of liquid/liquid ABS were examined. We have shown that ABS are indeed very tunable and LSERs have been used as a tool to compare these systems to traditional organic/water and other liquid/liquid systems. (2) We have successfully shown the development of novel reaction media for chemical synthesis and reaction; Aqueous Biphasic Reactive Extraction (ABRE). As a proof of concept, we have shown the synthesis of adipic acid from cyclohexene in an ABS, which represents an important development in the exploitation of this technology. Previous

  10. Aqueous biphasic system based on low-molecular-weight polyethylene glycol for one-step separation of crude polysaccharides from Pericarpium granati using high-speed countercurrent chromatography.

    PubMed

    Zhou, Xin-Yu; Zhang, Jing; Xu, Rui-Ping; Ma, Xue; Zhang, Zhi-Qi

    2014-10-03

    The aqueous biphasic system (ABS) plays a key role in the separation of bioactive substances, and the establishment and application of a low-molecular-weight polyethylene glycol (PEG) ABS remains a challenge in high-speed countercurrent chromatography (HSCCC). In this work, an ABS of low-molecular-weight PEG, namely PEG400-Na2SO4-H2O (20%-16%-64%, w/w/w), was developed on the basis of the phase diagram, and the phase forming time and ratio, and applied to HSCCC for the separation of polysaccharides. The crude polysaccharide extracted from Pericarpium granati (PGP) was successfully separated and three purified polysaccharides were obtained: PGP-1, with an average molecular weight of 13,210Da and composed of xylose (12.4%), ribose (10.1%), and glucose (77.5%); PGP-2, which is a homogeneous polysaccharide with an average molecular weight of 2584Da and consists of mannose; and PGP-3, with an average molecular weight of 2459Da and composed of ribose (51.4%), mannose (26.7%), and glucose (21.9%). This success shows that an ABS based on low-molecular-weight PEG could be applied to HSCCC separation technology. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Aqueous biphasic cancer cell migration assay enables robust, high-throughput screening of anti-cancer compounds.

    PubMed

    Lemmo, Stephanie; Nasrollahi, Samila; Tavana, Hossein

    2014-03-01

    Migration of tumor cells is a fundamental event implicated in metastatic progression of cancer. Therapeutic compounds with the ability to inhibit the motility of cancer cells are critical for preventing cancer metastasis. Achieving this goal requires new technologies that enable high-throughput drug screening against migration of cancer cells and expedite drug discovery. We report an easy-to-implement, robotically operated, cell migration microtechnology with the capability of simultaneous screening of multiple compounds. The technology utilizes a fully biocompatible polymeric aqueous two-phase system to pattern a monolayer of cells containing a cell-excluded gap that serves as the migration niche. We adapted this technology to a standard 96-well plate format and parametrically optimized it to generate highly consistent migration niches. The analysis of migration is done automatically using computerized schemes. We use statistical metrics and show the robustness of this assay for drug screening and its sensitivity to identify effects of different drug compounds on migration of cancer cells. This technology can be employed in core centers, research laboratories, and pharmaceutical industries to evaluate the efficacy of compounds against migration of various types of metastatic cancer cells prior to expensive animal tests and thus, streamline anti-migratory drug screening.

  12. Biphasic water splitting by osmocene

    PubMed Central

    Ge, Peiyu; Todorova, Tanya K.; Patir, Imren Hatay; Olaya, Astrid J.; Vrubel, Heron; Mendez, Manuel; Hu, Xile; Corminboeuf, Clémence; Girault, Hubert H.

    2012-01-01

    The photochemical reactivity of osmocene in a biphasic water-organic solvent system has been investigated to probe its water splitting properties. The photoreduction of aqueous protons to hydrogen under anaerobic conditions induced by osmocene dissolved in 1,2-dichloroethane and the subsequent water splitting by the osmocenium metal-metal dimer formed during H2 production were studied by electrochemical methods, UV-visible spectrometry, gas chromatography, and nuclear magnetic resonance spectroscopy. Density functional theory computations were used to validate the reaction pathways. PMID:22665787

  13. Biphasic catalysis in water/carbon dioxide micellar systems

    DOEpatents

    Jacobson, Gunilla B.; Tumas, William; Johnston, Keith P.

    2002-01-01

    A process is provided for catalyzing an organic reaction to form a reaction product by placing reactants and a catalyst for the organic reaction, the catalyst of a metal complex and at least one ligand soluble within one of the phases of said aqueous biphasic system, within an aqueous biphasic system including a water phase, a dense phase fluid, and a surfactant adapted for forming an emulsion or microemulsion within the aqueous biphasic system, the reactants soluble within one of the phases of the aqueous biphasic system and convertible in the presence of the catalyst to a product having low solubility in the phase in which the catalyst is soluble; and, maintaining the aqueous biphasic system under pressures, at temperatures, and for a period of time sufficient for the organic reaction to occur and form the reaction product and to maintain sufficient density on the dense phase fluid, the reaction product characterized as having low solubility in the phase in which the catalyst is soluble.

  14. Production, Purification, and Identification of Cholest-4-en-3-one Produced by Cholesterol Oxidase from Rhodococcus sp. in Aqueous/Organic Biphasic System

    PubMed Central

    Wu, Ke; Li, Wei; Song, Jianrui; Li, Tao

    2015-01-01

    Cholest-4-en-3-one has positive uses against obesity, liver disease, and keratinization. It can be applied in the synthesis of steroid drugs as well. Most related studies are focused on preparation of cholest-4-en-3-one by using whole cells as catalysts, but production of high-quality cholest-4-en-3-one directly from cholesterol oxidase (COD) using an aqueous/organic two-phase system has been rarely explored. This study set up an enzymatic reaction system to produce cholest-4-en-3-one. We developed and optimized the enzymatic reaction system using COD from COX5-6 (a strain of Rhodococcus) instead of whole-cell biocatalyst. This not only simplifies and accelerates the production but also benefits the subsequent separation and purification process. Through extraction, washing, evaporation, column chromatography, and recrystallization, we got cholest-4-en-3-one with purity of 99.78%, which was identified by nuclear magnetic resonance, mass spectroscopy, and infrared spectroscopy. In addition, this optimized process of cholest-4-en-3-one production and purification can be easily scaled up for industrial production, which can largely decrease the cost and guarantee the purity of the product. PMID:25733914

  15. Biphasic anaphylaxis to gemifloxacin.

    PubMed

    Yilmaz, Insu; Doğan, Serkan; Tutar, Nuri; Kanbay, Asiye; Büyükoğlan, Hakan; Demir, Ramazan

    2012-10-01

    Anaphylaxis have been documented as adverse effects of ciprofloxacin, ofloxacin, norfloxacin, levofloxacin, and moxifloxacin. However resistant and biphasic anaphlylactic reactions to gemifloxacin have not been reported to date. Management of severe anaphylaxis in the elderly can be complicated by concurrent medications such as beta (β) adrenergic, alpha (α) adrenergic blockers and angiotensin-converting enzyme (ACE) inhibitors. We report here in the case of a 60-year-old male who was taking on ACE inhibitor, α and β blockers and experienced a severe, resistant and biphasic anaphlylactic reaction to gemifloxacin mesylate.

  16. Oscillatory Motion of a Bi-Phasic Slug in a Teflon Reactor

    NASA Astrophysics Data System (ADS)

    Abolhasani, Milad; Jensen, Klavs

    2015-11-01

    Bi-phasic physical/chemical processes require transfer of solute/reagent molecules across the interface. Continuous multi-phase flow approaches (using gas as the continuous phase), usually fail in providing sufficient interfacial area for transfer of molecules between the aqueous and organic phases. In continuous segmented flow platforms (with a fluorinated polymer-based reactor), the higher surface tension of the aqueous phase compared to the organic phase of a bi-phasic slug, in combination with the low surface energy of the reactor wall result in a more facile motion of the aqueous phase. Thus, upon applying a pressure gradient across the bi-phasic slug, the aqueous phase of the slug moves through the organic phase and leads the bi-phasic slug, thereby limiting the available interfacial area for the bi-phasic mass transfer only to the semi-spherical interface between the two phases. Disrupting the quasi-equilibrium state of the bi-phasic slug through reversing the pressure gradient across the bi-phasic slug causes the aqueous phase to move back through the organic phase. In this work, we experimentally investigate the dynamics of periodic alteration of the pressure gradient across a bi-phasic slug, and characterize the resulting enhanced interfacial area on the bi-phasic mass transfer rate. We demonstrate the enhanced mass transfer rate of the oscillatory flow strategy compared to the continuous multi-phase approach using bi-phasic Pd catalyzed carbon-carbon and carbon-nitrogen cross coupling reactions. NSERC Postdoctoral Fellowship, Novartis Center for Continuous Manufacturing.

  17. Anthemis xylopoda flowers aqueous extract assisted in situ green synthesis of Cu nanoparticles supported on natural Natrolite zeolite for N-formylation of amines at room temperature under environmentally benign reaction conditions.

    PubMed

    Nasrollahzadeh, Mahmoud; Sajadi, S Mohammad; Hatamifard, Arezo

    2015-12-15

    Zeolites, which are nontoxic, abundant, and cheap, are very promising supports for the design and preparation of new and environmentally benign catalysts. In this study, Cu nanoparticles (NPs) were immobilized on the surface of natural Natrolite zeolite by Anthemis xylopoda flowers aqueous extract as a reducing and stabilizing agent. Afterward, the catalytic performance of the prepared catalyst was investigated for N-formylation of amines at room temperature under environmentally benign reaction conditions. The catalyst could be reused at least 5 times without any decrease in activity. The advantages of the present protocol include the use of green catalyst, easy isolation of the products, reusability of catalyst, absence of nontoxic reagents, and excellent yield of the products.

  18. Micrometer-scale mixing with Pickering emulsions: biphasic reactions without stirring.

    PubMed

    Zhang, Wenjuan; Fu, Luman; Yang, Hengquan

    2014-02-01

    A general strategy that avoids stirring for organic/aqueous reactions involving solid catalysts is reported. The strategy involves converting a conventional biphasic system into a Pickering emulsion phase with micrometer-scale droplets ensuring good mixing. In test reactions, nitrotoluene reduction and epoxidation of allylic alcohols, the reaction efficiency is comparable to conventional stirrer-driven biphasic catalysis reaction systems. Short diffusion distances, arising from the compartmentalization of densely packed droplets, play an important role in boosting the reaction efficiency.

  19. Benign Paroxysmal Positional Vertigo

    MedlinePlus

    ... Questionnaire Home Diseases and Conditions Benign Paroxysmal Positional Vertigo (BPPV) Benign Paroxysmal Positional Vertigo (BPPV) Condition Family HealthMenWomen Share Benign Paroxysmal Positional ...

  20. Efficient anti-Prelog enantioselective reduction of acetyltrimethylsilane to (R)-1-trimethylsilylethanol by immobilized Candida parapsilosis CCTCC M203011 cells in ionic liquid-based biphasic systems

    PubMed Central

    2012-01-01

    Background Biocatalytic asymmetric reductions with whole cells can offer high enantioselectivity, environmentally benign processes and energy-effective operations and thus are of great interest. The application of whole cell-mediated bioreduction is often restricted if substrate and product have low water solubility and/or high toxicity to the biocatalyst. Many studies have shown that a biphasic system is often useful in this instance. Hence, we developed efficient biphasic reaction systems with biocompatible water-immiscible ionic liquids (ILs), to improve the biocatalytic anti-Prelog enantioselective reduction of acetyltrimethylsilane (ATMS) to (R)-1-trimethylsilylethanol {(R)-1-TMSE}, which is key synthon for a large number of silicon-containing drugs, using immobilized Candida parapsilosis CCTCC M203011 cells as the biocatalyst. Results It was found that the substrate ATMS and the product 1-TMSE exerted pronounced toxicity to immobilized Candida parapsilosis CCTCC M203011 cells. The biocompatible water-immiscible ILs can be applied as a substrate reservoir and in situ extractant for the product, thus greatly enhancing the efficiency of the biocatalytic process and the operational stability of the cells as compared to the IL-free aqueous system. Various ILs exerted significant but different effects on the bioreduction and the performances of biocatalysts were closely related to the kinds and combination of cation and anion of ILs. Among all the water-immiscible ILs investigated, the best results were observed in 1-butyl-3-methylimidazolium hexafluorophosphate (C4mim·PF6)/buffer biphasic system. Furthermore, it was shown that the optimum substrate concentration, volume ratio of buffer to IL, buffer pH, reaction temperature and shaking rate for the bioreduction were 120 mM, 8/1 (v/v), 6.0, 30°C and 180 r/min, respectively. Under these optimized conditions, the initial reaction rate, the maximum yield and the product e.e. were 8.1 μmol/min gcwm, 98.6% and >99

  1. Benign methodology and improved synthesis of 5-(2-chloroquinolin-3-yl)-3-phenyl-4,5-dihydroisoxazoline using acetic acid aqueous solution under ultrasound irradiation.

    PubMed

    Tiwari, Vandana; Parvez, Ali; Meshram, Jyotsna

    2011-09-01

    In the present paper, we have executed the synthesis of substituted 5-(2-chloroquinolin-3-yl)-3-phenyl-4,5-dihydroisoxazolines via the reactions of substituted 3-(2-chloroquinolin-3-yl)-1-phenylprop-2-en-1-ones with hydroxylamine hydrochloride and sodium acetate in aqueous acetic acid solution in 72-90% yields at room temperature under ultrasound irradiation. This method provides several advantages such as operational simplicity, higher yield, safety and environment friendly protocol. The resulting substituted isoxazolines were characterized on the basis of (1)H NMR, (13)C NMR, IR, elemental analysis, and mass spectral data. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Evaluation of a biphasic in vitro dissolution test for estimating the bioavailability of carbamazepine polymorphic forms.

    PubMed

    Deng, Jia; Staufenbiel, Sven; Bodmeier, Roland

    2017-07-15

    The purpose of this study was to discriminate three crystal forms of carbamazepine (a BCS II drug) by in vitro dissolution testing and to correlate in vitro data with published in vivo data. A biphasic dissolution system (phosphate buffer pH6.8 and octanol) was used to evaluate the dissolution of the three polymorphic forms and to compare it with conventional single phase dissolution tests performed under sink and non-sink conditions. Similar dissolution profiles of three polymorphic forms were observed in the conventional dissolution test under sink conditions. Although a difference in dissolution was seen in the single phase dissolution test under non-sink conditions as well as in the aqueous phase of the biphasic test, little relevance for in vivo data was observed. In contrast, the biphasic dissolution system could discriminate between the different polymorphic forms in the octanol phase with a ranking of form III>form I>dihydrate form. This was in agreement with the in vivo performance. The dissolved drug available for oral absorption, which was dominated by dissolution and solution-mediated phase transformation, could be reflected in the biphasic dissolution test. Moreover, a good correlation was established between in vitro dissolution in the octanol phase of the biphasic test and in vivo pharmacokinetic data (R(2)=0.99). The biphasic dissolution method is a valuable tool to discriminate between different crystal forms in the formulations of poorly soluble drugs. Copyright © 2017. Published by Elsevier B.V.

  3. Efficient removal and environmentally benign detoxification of Cr(VI) in aqueous solutions by Zr(IV) cross-linking chitosan magnetic microspheres.

    PubMed

    Chen, Xiumei; Zhang, Wengang; Luo, Xueli; Zhao, Fan; Li, Yixuan; Li, Ronghua; Li, Zhonghong

    2017-10-01

    Zirconium(IV) cross-linking chitosan (CTS) magnetic microspheres (Fe3O4@Zr-CTS) as a recoverable adsorbent were synthesized through the coordination reaction between zirconium oxychloride and CTS biopolymeric matrix for efficient adsorption and simultaneous detoxification of hexavalent chromium, Cr(VI), in aqueous solutions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) confirmed the formation of core@shell magnetite microspheres. X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) verified the crosslinking of Zr(IV) to CTS on the microspheres. Batch Cr(VI) adsorption performances of the resultant Fe3O4@Zr-CTS microspheres revealed that the maximum adsorption capacity of 280.97 mg/g were achieved under pH 4.0 at 298 K. The XPS analyses indicated that 61.1% of the adsorbed Cr(VI) was reduced to Cr(III) due to the oxidization of alcoholic groups on C-6 in CTS which served as electron donors to carbonyl groups. The adsorbent showed preferential Cr(VI) adsorption with the existence of co-existing cations (K(+), Na(+), Cu(2+), Zn(2+), Ca(2+), Mg(2+)) and anions (NO3(-), Cl(-), SO4(2-), CO3(2-)). The adsorbent exhibited excellent reusability, lower the effluent Cr(VI) contents down to the ppb level, which satisfied the drinking water standard recommended by the World Health Organization and was a promising candidate for water purification. Copyright © 2017. Published by Elsevier Ltd.

  4. Enhancing productivity for cascade biotransformation of styrene to (S)-vicinal diol with biphasic system in hollow fiber membrane bioreactor.

    PubMed

    Gao, Pengfei; Wu, Shuke; Praveen, Prashant; Loh, Kai-Chee; Li, Zhi

    2017-03-01

    Biotransformation is a green and useful tool for sustainable and selective chemical synthesis. However, it often suffers from the toxicity and inhibition from organic substrates or products. Here, we established a hollow fiber membrane bioreactor (HFMB)-based aqueous/organic biphasic system, for the first time, to enhance the productivity of a cascade biotransformation with strong substrate toxicity and inhibition. The enantioselective trans-dihydroxylation of styrene to (S)-1-phenyl-1,2-ethanediol, catalyzed by Escherichia coli (SSP1) coexpressing styrene monooxygenase and an epoxide hydrolase, was performed in HFMB with organic solvent in the shell side and aqueous cell suspension in the lumen side. Various organic solvents were investigated, and n-hexadecane was found as the best for the HFMB-based biphasic system. Comparing to other reported biphasic systems assisted by HFMB, our system not only shield much of the substrate toxicity but also deflate the product recovery burden in downstream processing as the majority of styrene stayed in organic phase while the diol product mostly remained in the aqueous phase. The established HFMB-based biphasic system enhanced the production titer to 143 mM, being 16-fold higher than the aqueous system and 1.6-fold higher than the traditional dispersive partitioning biphase system. Furthermore, the combination of biphasic system with HFMB prevents the foaming and emulsification, thus reducing the burden in downstream purification. HFMB-based biphasic system could serve as a suitable platform for enhancing the productivity of single-step or cascade biotransformation with toxic substrates to produce useful and valuable chemicals.

  5. Biphasic nature of gastric emptying.

    PubMed Central

    Siegel, J A; Urbain, J L; Adler, L P; Charkes, N D; Maurer, A H; Krevsky, B; Knight, L C; Fisher, R S; Malmud, L S

    1988-01-01

    The existence of a lag phase during the gastric emptying of solid foods is controversial. It has been hypothesised that among other early events, the stomach requires a period of time to process solid food to particles small enough to be handled as a liquid. At present no standardised curve fitting techniques exist for the characterisation and quantification of the lag phase or the emptying rate of solids and liquids. We have evaluated the ability of a modified power exponential function to define the emptying parameters of two different solid meals. Dual labelled meals were administered to 24 normal volunteers. The subjects received meals consisting of either Tc-99m in vivo labelled chicken liver or Tc-99m-egg, which have different densities, and In-111-DTPA in water. The emptying curves were biphasic in nature. For solids, this represented an initial delay in emptying or lag phase followed by an equilibrium emptying phase characterised by a constant rate of emptying. The curves were analysed using a modified power exponential function of the form y(t) = 1-(1-e-kt)beta, where y(t) is the fractional meal retention at time t, k is the gastric emptying rate in min-1, and beta is the extrapolated y-intercept from the terminal portion of the curve. The length of the lag phase and half-emptying time increased with solid food density (31 +/- 8 min and 77.6 +/- 11.2 min for egg and 62 +/- 16 min and 94.1 +/- 14.2 min for chicken liver, respectively). After the lag phase, both solids had similar emptying rates, and these rates were identical to those of the liquids. In vitro experiments indicated that the egg meal disintegrated much more rapidly than the chicken liver under mechanical agitation in gastric juice, lending further support to the hypothesis that the initial lag in emptying of solid food is due to the processing of food into particles small enough to pass the pylorus. We conclude that the modified power exponential model permits characterisation of the biphasic

  6. Acute Biphasic Effects of Ayahuasca

    PubMed Central

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D.; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A.; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8–13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30–50 and 50–100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca’s chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered. PMID:26421727

  7. Acute Biphasic Effects of Ayahuasca.

    PubMed

    Schenberg, Eduardo Ekman; Alexandre, João Felipe Morel; Filev, Renato; Cravo, Andre Mascioli; Sato, João Ricardo; Muthukumaraswamy, Suresh D; Yonamine, Maurício; Waguespack, Marian; Lomnicka, Izabela; Barker, Steven A; da Silveira, Dartiu Xavier

    2015-01-01

    Ritual use of ayahuasca, an amazonian Amerindian medicine turned sacrament in syncretic religions in Brazil, is rapidly growing around the world. Because of this internationalization, a comprehensive understanding of the pharmacological mechanisms of action of the brew and the neural correlates of the modified states of consciousness it induces is important. Employing a combination of electroencephalogram (EEG) recordings and quantification of ayahuasca's compounds and their metabolites in the systemic circulation we found ayahuasca to induce a biphasic effect in the brain. This effect was composed of reduced power in the alpha band (8-13 Hz) after 50 minutes from ingestion of the brew and increased slow- and fast-gamma power (30-50 and 50-100 Hz, respectively) between 75 and 125 minutes. Alpha power reductions were mostly located at left parieto-occipital cortex, slow-gamma power increase was observed at left centro-parieto-occipital, left fronto-temporal and right frontal cortices while fast-gamma increases were significant at left centro-parieto-occipital, left fronto-temporal, right frontal and right parieto-occipital cortices. These effects were significantly associated with circulating levels of ayahuasca's chemical compounds, mostly N,N-dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine and some of their metabolites. An interpretation based on a cognitive and emotional framework relevant to the ritual use of ayahuasca, as well as it's potential therapeutic effects is offered.

  8. Recycling nanoparticle catalysts without separation based on a pickering emulsion/organic biphasic system.

    PubMed

    Liu, Huifang; Zhang, Zhiming; Yang, Hengquan; Cheng, Fangqin; Du, Zhiping

    2014-07-01

    A conceptually novel methodology is explored for in situ recycling of nanoparticle catalysts based on transforming a conventional organic/aqueous biphasic system into a Pickering emulsion/organic biphasic system (PEOBS). The suggested PEOBS exists as two phases, with the nanoparticle catalyst "anchored" in the Pickering emulsion phase, but is "continuous" between the organic phase and the continuous phase of the Pickering emulsion. Aqueous hydrogenations are used to evaluate the reaction performances of PEOBS, and the underlying principles of PEOBS are preliminarily elaborated. The unique properties of PEOBS lead to many intriguing findings, which are unlikely to be achieved in the reported biphasic systems. PEOBS exhibits more than a fourfold enhancement in catalysis efficiency in comparison with a conventional biphasic system. Impressively, PEOBS enables the organic product to be facilely isolated through simple decantation and the nanoparticle catalyst can be recycled in situ without the need for "separation". Its recycling effectiveness is justified by ten reaction cycles without significant catalyst loss. The simple protocol, in conjunction with the stability to simultaneously achieve high catalysis efficiency and excellent catalyst recyclability, makes PEOBS a promising methodology to develop more sustainable nanocatalysis.

  9. An effective biphase system accelerates hesperidinase-catalyzed conversion of rutin to isoquercitrin

    PubMed Central

    Wang, Jun; Gong, An; Yang, Cai-Feng; Bao, Qi; Shi, Xin-Yi; Han, Bei-Bei; Wu, Xiang-Yang; Wu, Fu-An

    2015-01-01

    Isoquercitrin is a rare, natural ingredient with several biological activities that is a key precursor for the synthesis of enzymatically modified isoquercitrin (EMIQ). The enzymatic production of isoquercitrin from rutin catalyzed by hesperidinase is feasible; however, the bioprocess is hindered by low substrate concentration and a long reaction time. Thus, a novel biphase system consisting of [Bmim][BF4]:glycine-sodium hydroxide (pH 9) (10:90, v/v) and glyceryl triacetate (1:1, v/v) was initially established for isoquercitrin production. The biotransformation product was identified using liquid chromatography-mass spectrometry, and the bonding mechanism of the enzyme and substrate was inferred using circular dichroism spectra and kinetic parameters. The highest rutin conversion of 99.5% and isoquercitrin yield of 93.9% were obtained after 3 h. The reaction route is environmentally benign and mild, and the biphase system could be reused. The substrate concentration was increased 2.6-fold, the reaction time was reduced to three tenths the original time. The three-dimensional structure of hesperidinase was changed in the biphase system, which α-helix and random content were reduced and β-sheet content was increased. Thus, the developed biphase system can effectively strengthen the hesperidinase-catalyzed synthesis of isoquercitrin with high yield. PMID:25731802

  10. Biphasic catalysis using amphiphilic polyphenols-chelated noble metals as highly active and selective catalysts

    PubMed Central

    Mao, Hui; Yu, Hong; Chen, Jing; Liao, Xuepin

    2013-01-01

    In the field of catalysis, it is highly desired to develop novel catalysts that combine the advantages of both homogeneous and heterogeneous catalysts. Here we disclose that the use of plant pholyphenol as amphiphilic large molecule ligand/stabilizer allows for the preparation of noble metal complex and noble metal nanoparticle catalysts. These catalysts are found to be highly selective and active in aqueous-organic biphasic catalysis of cinnamaldehyde and quinoline, and can be reused at least 3 times without significant loss of activity. Moreover, the catalytic activity and reusability of the catalysts can be rationally controlled by simply adjusting the content of polyphenols in the catalysts. Our strategy may be extended to design a wide range of aqueous-organic biphasic catalysis system. PMID:23863916

  11. Optical resolution of racemic 2-hydroxy octanoic acid by lipase-catalyzed hydrolysis in a biphasic membrane reactor.

    PubMed

    Sakaki, Keiji; Itoh, Naotsugu

    2003-10-01

    Racemic 2-hydroxy octanoic acid methyl ester was optically resolved by lipase-catalyzed hydrolysis in a biphasic membrane reactor using hydrophilic/hydrophobic capillary membranes. In a buffer/hexane biphasic membrane reactor using hydrophilic ultrafiltration membranes, (S)-2-hydroxy octanoic acid was recovered from the aqueous phase at 59-67% yield and 0.9-0.92 enantiomeric excess (ee), and the ester of (R)-isomer was recovered from the organic phase at 73-75% yield and 0.92-0.99 ee.

  12. Biodesulfurization in Biphasic Systems Containing Organic Solvents†

    PubMed Central

    Tao, Fei; Yu, Bo; Xu, Ping; Ma, Cui Qing

    2006-01-01

    Biphasic systems can overcome the problem of low productivity in conventional media and have been exploited for biocatalysis. Solvent-tolerant microorganisms are useful in biotransformation with whole cells in biphasic reactions. A solvent-tolerant desulfurizing bacterium, Pseudomonas putida A4, was constructed by introducing the biodesulfurizing gene cluster dszABCD, which was from Rhodococcus erythropolis XP, into the solvent-tolerant strain P. putida Idaho. Biphasic reactions were performed to investigate the desulfurization of various sulfur-containing heterocyclic compounds in the presence of various organic solvents. P. putida A4 had the same substrate range as R. erythropolis XP and could degrade dibenzothiophene at a specific rate of 1.29 mM g (dry weight) of cells−1 h−1 for the first 2 h in the presence of 10% (vol/vol) p-xylene. P. putida A4 was also able to degrade dibenzothiophene in the presence of many other organic solvents at a concentration of 10% (vol/vol). This study is a significant step in the exploration of the biotechnological potential of novel biocatalysts for developing an efficient biodesulfurization process in biphasic reaction mixtures containing toxic organic solvents. PMID:16820450

  13. Use of the electrically driven emulsion-phase contactor for a biphasic liquid-liquid enzyme system

    SciTech Connect

    Scott, T.C.; Cosgrove, J.M.; DePaoli, D.W.

    1995-12-31

    An alternative approach to the operation of bioprocessing systems within non-aqueous environments would require the development of reaction systems that would provide effective interfacial contact between the biocatalyst, contained within an aqueous phase, and the organic phase containing the substrate. A biphasic liquid-liquid (BLL) reactor that provides for intimate liquid-liquid contact would be the most probable approach for this application. For the BLL reactions considered in this work, the overall effectiveness of the system will depend on both compatibility of the biocatalyst with the chemical species present and intrinsic reaction and interfacial transport phenomena typically involved with liquid-liquid operations. The focus of this article is to investigate the removal and oxidation of p-cresol dissolved in toluene by aqueous-phase horseradish peroxidase. Contacting of the liquid-liquid biphasic enzyme system is carried out in an advanced solvent extraction contacting device, the electrically driven emulsion-phase contactor (EPC).

  14. A comparison of biphasic and monophasic shocks for external defibrillation. Physio-Control Biphasic Investigators.

    PubMed

    Higgins, S L; Herre, J M; Epstein, A E; Greer, G S; Friedman, P L; Gleva, M L; Porterfield, J G; Chapman, F W; Finkel, E S; Schmitt, P W; Nova, R C; Greene, H L

    2000-01-01

    The ability of a shock to defibrillate the heart depends on its waveform and energy. Past studies of biphasic truncated exponential (BTE) shocks for external defibrillation focused on low energy levels. This prospective, randomized, double-blind clinical trial compared the first-shock efficacies of 200-joule (J) BTE, 130-J BTE, and 200-J monophasic damped sine wave shocks. Ventricular fibrillation (VF) was induced in 115 patients during evaluation of implantable cardioverter-defibrillator function and 39 patients during electrophysiologic evaluation of ventricular arrhythmias. After 19 +/- 10 seconds of VF, a randomized transthoracic shock was administered. Mean first-shock success rates of the three groups were compared using a "Tukey-like" statistical test, adjusting for multiple comparisons. Blood pressures and arterial oxygen saturations were measured before VF induction and 30, 90, and 150 seconds after successful defibrillation. First-shock success rates were 61/68 (90%) for 200-J monophasic, 39/39 (100%) for 200-J biphasic, and 39/47 (83%) for 130-J biphasic shocks. The 200-J biphasic shocks were simultaneously superior in first-shock efficacy to both 200-J monophasic and 130-J biphasic shocks (experimentwise error rate, alpha < 0.01). There was no significant difference between the efficacies of 200-J monophasic and 130-J biphasic shocks, nor was there any significant difference between the three groups in hemodynamic parameters after successful shocks. Biphasic shocks of 200 J provide better first-shock defibrillation efficacy for short-duration VF than 200-J monophasic and 130-J biphasic shocks and thus may allow earlier termination of VF in cardiac arrest patients.

  15. Robotic benign esophageal procedures.

    PubMed

    Hanna, Jennifer M; Onaitis, Mark W

    2014-05-01

    Robotic master-slave devices can assist surgeons to perform minimally invasive esophageal operations with approaches that have already been demonstrated using laparoscopy and thoracoscopy. Robotic-assisted surgery for benign esophageal disease is described for the treatment of achalasia, epiphrenic diverticula, refractory reflux, paraesophageal hernias, duplication cysts, and benign esophageal masses, such as leiomyomas. Indications and contraindications for robotic surgery in benign esophageal disease should closely approximate the indications for laparoscopic and thoracoscopic procedures. Given the early application of the technology and paucity of clinical evidence, there are currently no procedures for which robotic esophageal surgery is the clinically proven preferred approach. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Benign prostate hyperplasia (BPH) - resources

    MedlinePlus

    Resources - benign prostatic hyperplasia (BPH); Prostate enlargement resources; BPH resources ... organizations provide information on benign prostatic hyperplasia ( prostate enlargement ): National Kidney and Urologic Diseases Information Clearinghouse -- www. ...

  17. Biomimetic biphasic scaffolds for osteochondral defect repair

    PubMed Central

    Li, Xuezhou; Ding, Jianxun; Wang, Jincheng; Zhuang, Xiuli; Chen, Xuesi

    2015-01-01

    The osteochondral defects caused by vigorous trauma or physical disease are difficult to be managed. Tissue engineering provides a possible option to regenerate the damaged osteochondral tissues. For osteochondral reconstruction, one intact scaffold should be considered to support the regeneration of both cartilage and subchondral bone. Therefore, the biphasic scaffolds with the mimic structures of osteochondral tissues have been developed to close this chasm. A variety of biomimetic bilayer scaffolds fabricated from natural or synthetic polymers, or the ones loading with growth factors, cells, or both of them make great progresses in osteochondral defect repair. In this review, the preparation and in vitro and/or in vivo verification of bioinspired biphasic scaffolds are summarized and discussed, as well as the prospect is predicted. PMID:26816644

  18. Benign positional vertigo - aftercare

    MedlinePlus

    Vertigo - positional - aftercare; Benign paroxysmal positional vertigo - aftercare; BPPV - aftercare; Dizziness - positional vertigo ... Your health care provider may have treated your vertigo with the Epley maneuver . These are head movements ...

  19. Benign positional vertigo

    MedlinePlus

    ... Clinical practice guideline: Benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg . 2008;139(5 Suppl 4):S47-S81. ... BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. Philadelphia, PA: Elsevier Mosby; 2015: ...

  20. The Benign Hamburger.

    ERIC Educational Resources Information Center

    Peaslee, Graham; Lantz, Juliette M.; Walczak, Mary M.

    1998-01-01

    Uses a case study of food poisoning from hamburgers at the fictitious Jill-at-the-Grill to teach the nuclear science behind food irradiation. Includes case teaching notes on the benign hamburger. (ASK)

  1. Benign cystic peritoneal mesothelioma.

    PubMed Central

    Bhandarkar, D S; Smith, V J; Evans, D A; Taylor, T V

    1993-01-01

    The well defined but rare entity of benign cystic mesothelioma is reported. The aetiology of this neoplasm remains obscure. The presenting features make a precise preoperative diagnosis difficult; information provided by computed tomography and cytology may help. A firm diagnosis can only come from electron microscopic or immunohistochemical examination of the tumour. Diagnostic accuracy and diligent follow up are essential because, although the tumour is considered benign, it does tend towards local recurrence. Images PMID:8227441

  2. Aqueduct stenosis-?Benign.

    PubMed

    Allan, Rodney; Chaseling, Raymond; Graf, Nicole; Dexter, Mark

    2005-02-01

    'Benign' aqueduct stenosis is a common cause of hydrocephalus in the paediatric population and is frequently treated by endoscopic third ventriculostomy. Occasionally, aqueduct stenosis can be a prelude to the development of other pathology, as is seen in these two cases of pineal tumours developing in patients whose hydrocephalus was successfully treated with endoscopic third ventriculostomy. The case histories are presented, along with the recommendation for increased radiological screening of patients with this usually 'benign' presentation.

  3. Persistent benign pleural effusion.

    PubMed

    Porcel, J M

    In this narrative review we describe the main aetiologies, clinical characteristics and treatment for patients with benign pleural effusion that characteristically persists over time: chylothorax and cholesterol effusions, nonexpansible lung, rheumatoid pleural effusion, tuberculous empyema, benign asbestos pleural effusion and yellow nail syndrome. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  4. Truncated biphasic pulses for transthoracic defibrillation.

    PubMed

    Bardy, G H; Gliner, B E; Kudenchuk, P J; Poole, J E; Dolack, G L; Jones, G K; Anderson, J; Troutman, C; Johnson, G

    1995-03-15

    Early defibrillation is the single most important factor for improving out-of-hospital ventricular fibrillation resuscitation rates. To achieve the earlier response times required for survival, typically < 6 minutes from time of collapse, it will be necessary to equip a far wider network of first responders (firefighters, police, and other individuals with responsibility for public safety) with small, lightweight, and inexpensive automatic external defibrillators (AEDs). An important step in reducing the size and cost of AEDs will be to improve defibrillation efficacy. Because biphasic waveform defibrillation has had a favorable impact on implantable cardioverter-defibrillators (ICDs), there are reasons to believe that biphasic waveforms would also improve transthoracic defibrillators. Our purpose, therefore, was to examine the efficacy of two different low-energy biphasic truncated waveforms referenced to a standard damped sine waveform for transthoracic defibrillation in humans. We prospectively and randomly compared the transthoracic defibrillation efficacy of two different truncated biphasic waveforms, 115 J (70 microF) and 130 J (105 microF), with that of a standard 200-J (36-microF, 28-mH) damped sine wave pulse using right anterior and left lateral thoracic pads (R2 Medical Systems) in 30 cardiac arrest survivors during transvenous ICD surgery. The right anterior patch electrode was used as the cathode and the left lateral thoracic pad as the anode. Transthoracic ventricular defibrillation rescue shocks were tested after a failed transvenous defibrillation shock delivered in the course of ICD testing. Each of the three different rescue shocks was tested in random order in each patient. All shocks were delivered at end expiration. The investigators responsible for determining transthoracic shock efficacy were blinded throughout the study to the transthoracic rescue waveform used. A total of 33 patients were considered for study, but three patients failed to

  5. Comparison of single-biphasic versus sequential-biphasic shocks on defibrillation threshold in pigs.

    PubMed

    Csanadi, Z; Jones, D L; Wood, G K; Klein, G J

    1997-06-01

    Current generation implantable cardioverter defibrillators use monophasic, biphasic, or sequential pulse shocks, most of which truncate after a given time, dumping the remaining charge on the capacitor through an internal resistor. We hypothesized that having an additional current pathway, and delivering the majority of the remaining charge on a single capacitor to the two pathways using additional shock phases, would improve defibrillation efficacy. This hypothesis was tested by comparing DFTs using a simulated single capacitor, single-biphasic shock (two 5-ms pulses separated by 0.2 ms), delivered to coupled pairs of electrodes, to those using a sequential-biphasic shock (four 5-ms pulses separated by 0.2 ms) delivered to separate opposing electrodes, delivered from the same electrodes for both waveforms. In eight open-chest anesthetized pigs, four mesh electrodes (Medtronic TX-7, 6.5 cm2), were sutured on the epicardium of the anterior and posterior surfaces of each ventricle. Shocks were delivered from a 200-microF capacitor bank. Triplicate DFTs were obtained using each waveform in a randomized crossover design. Initial leading edge voltage (mean +/- SEM: 420 +/- 33 V vs 497 +/- 34 V; P < 0.05), initial peak current (4.8 +/- 0.4 A vs 13 +/- 1.1 A; P < 0.001), and delivered energy (16.9 +/- 2.6 J vs 30.4 +/- 5.3 J; P < 0.05) at the DFT were all significantly lower using sequential-biphasic shocks than those using single-biphasic shocks, respectively. We conclude that for direct heart defibrillation, it is worthwhile to combine sequential capability to biphasic shocks and deliver the remaining charge on the capacitor to the two different pathways.

  6. Developmental Venous Anomaly: Benign or Not Benign.

    PubMed

    Aoki, Rie; Srivatanakul, Kittipong

    2016-09-15

    Developmental venous anomalies (DVAs), previously called venous angiomas, are the most frequently encountered cerebral vascular malformations. However, DVA is considered to be rather an extreme developmental anatomical variation of medullary veins than true malformation. DVAs are composed of dilated medullary veins converging centripetally into a large collecting venous system that drains into the superficial or deep venous system. Their etiology and mechanism are generally accepted that DVAs result from the focal arrest of the normal parenchymal vein development or occlusion of the medullary veins as a compensatory venous system. DVAs per se are benign and asymptomatic except for under certain unusual conditions. The pathomechanisms of symptomatic DVAs are divided into mechanical, flow-related causes, and idiopathic. However, in cases of DVAs associated with hemorrhage, cavernous malformations (CMs) are most often the cause rather than DVAs themselves. The coexistence of CM and DVA is common. There are some possibilities that DVA affects the formation and clinical course of CM because CM related to DVA is generally located within the drainage territory of DVA and is more aggressive than isolated CM in the literature. Brain parenchymal abnormalities surrounding DVA and cerebral varix have also been reported. These phenomena are considered to be the result of venous hypertension associated with DVAs. With the advance of diagnostic imagings, perfusion study supports this hypothesis demonstrating that some DVAs have venous congestion pattern. Although DVAs should be considered benign and clinically silent, they can have potential venous hypertension and can be vulnerable to hemodynamic changes.

  7. Developmental Venous Anomaly: Benign or Not Benign

    PubMed Central

    AOKI, Rie; SRIVATANAKUL, Kittipong

    2016-01-01

    Developmental venous anomalies (DVAs), previously called venous angiomas, are the most frequently encountered cerebral vascular malformations. However, DVA is considered to be rather an extreme developmental anatomical variation of medullary veins than true malformation. DVAs are composed of dilated medullary veins converging centripetally into a large collecting venous system that drains into the superficial or deep venous system. Their etiology and mechanism are generally accepted that DVAs result from the focal arrest of the normal parenchymal vein development or occlusion of the medullary veins as a compensatory venous system. DVAs per se are benign and asymptomatic except for under certain unusual conditions. The pathomechanisms of symptomatic DVAs are divided into mechanical, flow-related causes, and idiopathic. However, in cases of DVAs associated with hemorrhage, cavernous malformations (CMs) are most often the cause rather than DVAs themselves. The coexistence of CM and DVA is common. There are some possibilities that DVA affects the formation and clinical course of CM because CM related to DVA is generally located within the drainage territory of DVA and is more aggressive than isolated CM in the literature. Brain parenchymal abnormalities surrounding DVA and cerebral varix have also been reported. These phenomena are considered to be the result of venous hypertension associated with DVAs. With the advance of diagnostic imagings, perfusion study supports this hypothesis demonstrating that some DVAs have venous congestion pattern. Although DVAs should be considered benign and clinically silent, they can have potential venous hypertension and can be vulnerable to hemodynamic changes. PMID:27250700

  8. Nucleic Acid Sample Preparation using Spontaneous Biphasic Plug Flow

    PubMed Central

    Thomas, Peter C.; Strotman, Lindsay N.; Theberge, Ashleigh B.; Berthier, Erwin; O’Connell, Rachel; Loeb, Jennifer M.; Berry, Scott M.; Beebe, David J.

    2013-01-01

    Nucleic acid (NA) extraction and purification has become a common technique in both research and clinical laboratories. Current methods require repetitive wash steps with a pipette that is laborious and time consuming making it inefficient for clinical settings. We present here a simple technique that relies on spontaneous biphasic plug flow inside a capillary to achieve sample preparation. By filling the sample with oil, aqueous contaminants were displaced from the captured NA without pipetting wash buffers or use of external force and equipment. mRNA from mammalian cell culture was purified and PCR amplification showed similar threshold cycle values as those obtained from a commercially available kit. HIV viral like particles were spiked into serum and a 5-fold increase in viral RNA extraction yield was achieved compared to the conventional wash method. In addition, viral RNA was successfully purified from human whole blood, and a limit of detection of approximately 14 copies of RNA extracted per sample. The results demonstrate the utility of the current technique for nucleic acid purification for clinical purposes, and the overall approach provides a potential method to implement nucleic acid testing in low resource settings. PMID:23941230

  9. Nucleic acid sample preparation using spontaneous biphasic plug flow.

    PubMed

    Thomas, Peter C; Strotman, Lindsay N; Theberge, Ashleigh B; Berthier, Erwin; O'Connell, Rachel; Loeb, Jennifer M; Berry, Scott M; Beebe, David J

    2013-09-17

    Nucleic acid (NA) extraction and purification has become a common technique in both research and clinical laboratories. Current methods require repetitive wash steps with a pipet that are laborious and time-consuming, making the procedure inefficient for clinical settings. We present here a simple technique that relies on spontaneous biphasic plug flow inside a capillary to achieve sample preparation. By filling the sample with oil, aqueous contaminants were displaced from the captured NA without pipetting wash buffers or use of external force and equipment. mRNA from mammalian cell culture was purified, and polymerase chain reaction (PCR) amplification showed similar threshold cycle values as those obtained from a commercially available kit. Human immunodeficiency virus (HIV) viral-like particles were spiked into serum and a 5-fold increase in viral RNA extraction yield was achieved compared to the conventional wash method. In addition, viral RNA was successfully purified from human whole blood, and a limit of detection of approximately 14 copies of RNA extracted per sample was determined. The results demonstrate the utility of the current technique for nucleic acid purification for clinical purposes, and the overall approach provides a potential method to implement nucleic acid testing in low-resource settings.

  10. Synthesis and characterization of magnesium substituted biphasic mixtures of controlled hydroxyapatite/{beta}-tricalcium phosphate ratios

    SciTech Connect

    Kannan, S.; Lemos, I.A.F.; Rocha, J.H.G.; Ferreira, J.M.F. . E-mail: jmf@cv.ua.pt

    2005-10-15

    The present paper investigates the preparation of magnesium (Mg) substituted biphasic mixtures of different hydroxyapatite (HAP)/{beta}-tricalcium phosphate ({beta}-TCP) ratios through aqueous precipitation method. The concentrations of added magnesium (Mg) were varied with the calcium in order to obtain constant (Ca+Mg)/P ratios of 1.67 ranging from 1.62+0.05, 1.58+0.09 and 1.54+0.13, respectively. The as prepared powders were calcined at different temperatures to study the phase behaviour and thermal stability. The powders were characterized by the following analytical techniques: TG-DTA, X-ray diffraction and FT-IR. The results have shown that substitution of Mg in the calcium-deficient apatites resulted in the formation of biphasic mixtures of different HAP/{beta}-TCP ratios after heating above 700 deg. C. The ratios of the formation of phase mixtures were dependent on the calcium deficiency in the apatites with the higher deficiency having the strongest impact on the increased formation of {beta}-TCP and the substituted Mg was found to stabilize the {beta}-TCP phase. - Graphical abstract: Role of Mg in the behaviour of calcium-deficient apatites during calcination to form biphasic mixtures.

  11. Primary hepatic benign schwannoma

    PubMed Central

    Hayashi, Michihiro; Takeshita, Atsushi; Yamamoto, Kazuhiro; Tanigawa, Nobuhiko

    2012-01-01

    Schwannoma is predominantly a benign neoplasm of the Schwann cells in the neural sheath of the peripheral nerves. Occurrence of schwannoma in parenchymatous organs, such as liver, is extremely rare. A 64-year-old man without neurofibromatosis was observed to have a space-occupying lesion of 23mm diameter in the liver during follow-up examination for a previously resected gastrointestinal stromal tumor (GIST) in the small intestine. He underwent lateral segmentectomy of the liver under a provisional diagnosis of hepatic metastatic recurrence of the GIST. Histological examination confirmed the diagnosis of a benign schwannoma, confirmed by characteristic pathological findings and positive immunoreactions with the neurogenic marker S-100 protein, but negative for c-kit, or CD34. The tumor was the smallest among the reported cases. When the primary hepatic schwannoma is small in size, preoperative clinical diagnosis is difficult. Therefore, this disease should be listed as differential diagnosis for liver tumor with clinically benign characteristics. PMID:22530081

  12. Benign cutaneous Degos disease.

    PubMed

    Zamiri, Mozheh; Jarrett, Paul; Snow, John

    2005-08-01

    A 24-year-old woman presented with an 8-year history of a recurrent asymptomatic rash characterized by small erythematous papules which evolved to form atrophic porcelain white scars with a telangectatic rim. She had never had gastrointestinal or neurological symptoms. A short trial of aspirin did not alter the behavior of the disease. Histology confirmed the clinical diagnosis of Degos disease. Degos disease is a rare disorder that has been classified into the benign or malignant variety. The malignant type has a poor prognosis. Gastrointestinal involvement is the most frequent cause of death. The existence of patients with a prolonged, purely cutaneous or benign form has been increasingly recognized. It may be impossible to classify a patient at the time of initial presentation. Her progress is consistent with the benign form.

  13. Novel biphasic separations utilising highly selective molecularly imprinted polymers as biorecognition solvent extraction agents.

    PubMed

    Castell, Oliver K; Allender, Christopher J; Barrow, David A

    2006-10-15

    Molecularly imprinted polymers (MIPs) represent a class of artificial receptors that promise an environmentally robust alternative to naturally occurring biorecognition elements of biosensing devices and systems. However, in general, the performance of conventional MIPs in aqueous environments is poor. In the study reported here, this limitation has been addressed by the novel application of MIPs as a solvent extraction solid phase in a biphasic solvent system. This paper describes a previously unreported use of MIPs as solvent extraction reagents, their successful application to aqueous sample media and the opportunities for utilisation of this unique system in novel biosensing and separation procedures. This study demonstrates the development of a novel biphasic solvent system utilising MIP in the extracting phase to enhance both efficiency and selectivity of a simple two phase liquid extraction. Monodisperse propranolol imprinted polymer microspheres [p(divinylbenzene-co-methacrylic acid)] were prepared by precipitation polymerisation. Initially, the affinity of the polymers for (R,S)-propranolol was assessed by established techniques whereby the MIP demonstrated greater affinity for the template than did the non-imprinted control polymer (NIP). Importantly, MIP performance was also assessed using the novel dual solvent system. The depletion of (R,S)-propranolol from the aqueous phase into the polymer containing organic phase was determined. When compared to control extractions containing no polymer the presence of MIP in the extracting solvent phase resulted in an increased extraction of (R,S)-propranolol from the aqueous phase. Importantly, this extraction was significantly greater in the presence of MIP when compared to NIP. This unique principle generates opportunities for MIP based extractions and chemical enrichments in industrial applications, offering commercial, ecological and practical advantages to traditional solvent extraction techniques. The

  14. [Benign chronic pain].

    PubMed

    Serrie, A; Thurel, C

    1994-09-15

    Recent data indicate that 25 to 30% of the population in industrialized countries suffers from benign chronic pain. Among these patients, 50 to 75% are professionally incapable for varied lengths of time, from a few days to some weeks or months, or even definitively. The aetiology and clinical presentation of chronic benign pain are enormously varied because this definition includes such different pathologies as headache, pain of rheumatologic, postsurgical, organic, and post-zoster origin, lombalgia, radiculalgia, post-amputation pain, neuropathologic pain, causalgia, algoneurodystrophic pain, psychosomatic and idiopathic pain. Since these syndromes and causes of pain could not be discussed individually, they have been grouped according to their neurophysiology and pathophysiology.

  15. A Rare Case of a Benign Primary Pleomorphic Adenoma of the Lung

    PubMed Central

    Saladi, Swetha; Patolia, Setu; Mahmoud Assaf, Sara; Stoeckel, David

    2017-01-01

    Salivary gland tumors (SGT) constitute a small proportion of primary respiratory system neoplasms. Benign SGT comprises pleomorphic adenoma and is exceedingly rare in the lungs. We hereby present a rare case of a benign primary pleomorphic adenoma of the lung. The histological pattern of the tumor was indistinguishable from the head and neck SGT counterparts and showed biphasic morphology. Malignant features were not observed and a metastatic SGT was ruled out. Although little is known about the clinical progression of these rare tumors, surgical resection and interval surveillance remains the treatment of choice. PMID:28409070

  16. Biphasic cell responses on laterally mobile films

    NASA Astrophysics Data System (ADS)

    Kourouklis, Andreas; Lerum, Ronald; Bermudez, Harry

    2013-03-01

    The engineering of polymer surfaces or matrices that are capable of controlling cell adhesion has been widely explored. In nearly all of these works, the polymer chains (and ligands) are chemically attached to the underlying substrate, and therefore these systems are inherently static. By contrast, cellular environments such as the extracellular matrix (ECM) are dynamic and remodeled by biochemical reactions and biophysical forces. Borrowing this concept from Nature, we created polymer films by an interfacial self-assembly process, whereby individual chains can exhibit lateral mobility (in-plane diffusive motion). NIH 3T3 fibroblasts seeded on such RGD-presenting polymer films show biphasic responses in spreading and adhesion strength to lateral mobility, with a minimal response for intermediate mobility values. Futhermore, preliminary immuno-staining experiments reveal that the total area of focal adhesions demonstrates a similar biphasic trend to the cellular-scale behaviors. In contrast, actin filaments or stress fibers appear to be unaffected by the substrate lateral mobility. These results show that lateral mobility is an important, although not fully explored aspect of mechano-sensing by cells, and can potentially give new perspectives on cell-ECM interactions. National Science Foundation

  17. Biphasic ⁶⁸Ga-PSMA-HBED-CC-PET/CT in patients with recurrent and high-risk prostate carcinoma.

    PubMed

    Sahlmann, Carsten-Oliver; Meller, Birgit; Bouter, Caroline; Ritter, Christian Oliver; Ströbel, Philipp; Lotz, Joachim; Trojan, Lutz; Meller, Johannes; Hijazi, Sameh

    2016-05-01

    Binding of (68)Ga-PSMA-HBED-CC ((68)Ga-PSMA) at prostate cancer (PC) cells increases over time. A biphasic protocol may help separating benign from tumor lesions. The aim of this study was the retrospective evaluation of a diagnostic incremental value of a dual-time point (biphasic) (68)Ga-PSMA-PET/CT in patients with prostate cancer. Retrospective analysis of 35 consecutive patients (49-78 years, median 71) with newly diagnosed PC (12/35) or recurrence of PC (23/35). PET/CT (Gemini TF16, Philips) was acquired 1 h and 3 h p. i. of 140-392 MBq (300 MBq median) (68)Ga-PSMA, followed by a diagnostic contrast CT. PET findings were correlated with histology or unequivocal CT findings. Semiquantitative PET data (SUVmax, SUV mean) were acquired and target-to-background-ratios (T/B-ratio) were calculated for benign and malign lesions for both time points. Size of lymph nodes (LN) on diagnostic CT was recorded. Statistical analysis was performed for assessment of significant changes of semiquantitative PET-parameters over time and for correlation of size and uptake of lymph nodes. One hundred and four lesions were evaluated. Sixty lesions were referenced by histology or unequivocal CT findings, including eight (13.3 %) histopathologically benign lymph nodes, 12 (20 %) histopathologically lymph node metastases, 12 (20 %) primary tumors, three (5 %) local recurrences, and 25 (41.7 %) bone metastases. Forty-four lesions were axillary LN with normal CT-appearance. Benign lesions had significantly lower SUVmax and T/B-ratios compared with malignant findings. Malign lesions showed a significant increase of both parameters over time compared to benign findings. There was no correlation between LN size and SUVmax. The sensitivity, specificity, the positive predictive value and negative predictive value of PET/CT regarding pelvic LN was 94 %, 99 %, 89 %, and 99.5 %, respectively. In contrast to benign tissues, the uptake of proven tumor lesions increases on (68)Ga-PSMA-PET/CT over

  18. Benign multicystic peritoneal mesothelioma.

    PubMed

    Uzüm, Nüket; Ozçay, Necdet; Ataoğlu, Omür

    2009-06-01

    Benign multicystic peritoneal mesothelioma is a rare tumor that occurs mainly in women in their reproductive age. It is characterized by the formation of multiple, thin-walled, multilocular cysts that frequently produce large, intra-abdominal masses. The short follow-ups and possible etiologies based on the published reports make it difficult to draw any firm conclusions.

  19. Biphasic microtiter method for campylobacter recovery and enumeration

    USDA-ARS?s Scientific Manuscript database

    We developed a biphasic method for recovery and enumeration of campylobacters. The biphasic system was composed of 96-well microtiter plates containing Campy-Line Agar (CLA) prepared 2X for all ingredients except for 1X agar (0.1 ml per well). Samples of pure Campylobacter spp. isolates, post-chi...

  20. Steroid biotransformations in biphasic systems with Yarrowia lipolytica expressing human liver cytochrome P450 genes

    PubMed Central

    2012-01-01

    Background Yarrowia lipolytica efficiently metabolizes and assimilates hydrophobic compounds such as n-alkanes and fatty acids. Efficient substrate uptake is enabled by naturally secreted emulsifiers and a modified cell surface hydrophobicity and protrusions formed by this yeast. We were examining the potential of recombinant Y. lipolytica as a biocatalyst for the oxidation of hardly soluble hydrophobic steroids. Furthermore, two-liquid biphasic culture systems were evaluated to increase substrate availability. While cells, together with water soluble nutrients, are maintained in the aqueous phase, substrates and most of the products are contained in a second water-immiscible organic solvent phase. Results For the first time we have co-expressed the human cytochromes P450 2D6 and 3A4 genes in Y. lipolytica together with human cytochrome P450 reductase (hCPR) or Y. lipolytica cytochrome P450 reductase (YlCPR). These whole-cell biocatalysts were used for the conversion of poorly soluble steroids in biphasic systems. Employing a biphasic system with the organic solvent and Y. lipolytica carbon source ethyl oleate for the whole-cell bioconversion of progesterone, the initial specific hydroxylation rate in a 1.5 L stirred tank bioreactor was further increased 2-fold. Furthermore, the product formation was significantly prolonged as compared to the aqueous system. Co-expression of the human CPR gene led to a 4-10-fold higher specific activity, compared to the co-overexpression of the native Y. lipolytica CPR gene. Multicopy transformants showed a 50-70-fold increase of activity as compared to single copy strains. Conclusions Alkane-assimilating yeast Y. lipolytica, coupled with the described expression strategies, demonstrated its high potential for biotransformations of hydrophobic substrates in two-liquid biphasic systems. Especially organic solvents which can be efficiently taken up and/or metabolized by the cell might enable more efficient bioconversion as compared

  1. Facile synthesis and photocatalytic activity of bi-phase dispersible Cu-ZnO hybrid nanoparticles.

    PubMed

    Liu, Xiao; Liu, HongLing; Zhang, WenXing; Li, XueMei; Fang, Ning; Wang, XianHong; Wu, JunHua

    2015-01-01

    Bi-phase dispersible Cu-ZnO hybrid nanoparticles were synthesized by one-pot non-aqueous nanoemulsion with the use of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) show high crystallinity of the Cu-ZnO hybrid nanoparticles and an average particle size of ~19.4 nm. The ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL) demonstrate well dispersibility and excellent optical performance of Cu-ZnO hybrid nanoparticles both in organic and aqueous solvent. The X-ray photoelectron spectroscopy (XPS) confirms Cu(1+) and Cu(2+) in ZnO. The observation using Sudan red (III) as probe molecule reveals that the Cu-ZnO hybrid nanoparticles possess enhanced photocatalytic activity and stability which are promising for potential applications in photocatalysis.

  2. Facile synthesis and photocatalytic activity of bi-phase dispersible Cu-ZnO hybrid nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Liu, HongLing; Zhang, WenXing; Li, XueMei; Fang, Ning; Wang, XianHong; Wu, JunHua

    2015-04-01

    Bi-phase dispersible Cu-ZnO hybrid nanoparticles were synthesized by one-pot non-aqueous nanoemulsion with the use of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The transmission electron microscopy (TEM) and X-ray diffraction (XRD) show high crystallinity of the Cu-ZnO hybrid nanoparticles and an average particle size of ~19.4 nm. The ultraviolet-visible light absorbance spectrometry (UV-vis) and photoluminescence spectrophotometry (PL) demonstrate well dispersibility and excellent optical performance of Cu-ZnO hybrid nanoparticles both in organic and aqueous solvent. The X-ray photoelectron spectroscopy (XPS) confirms Cu1+ and Cu2+ in ZnO. The observation using Sudan red (III) as probe molecule reveals that the Cu-ZnO hybrid nanoparticles possess enhanced photocatalytic activity and stability which are promising for potential applications in photocatalysis.

  3. Benign Paroxysmal Positional Vertigo (BPPV)

    MedlinePlus

    ... Rated Nonprofit! Volunteer. Donate. Review. Benign Paroxysmal Positional Vertigo (BPPV) BPPV is the most common vestibular disorder. Benign Paroxysmal Positional Vertigo (or BPPV) is the most common cause of ...

  4. Biphasic versus monophasic shock waveform for conversion of atrial fibrillation.

    PubMed

    Rho, Robert W; Page, Richard L

    2003-09-01

    Cardioversion of atrial fibrillation (AF) using traditional monophasic shock waveform is unsuccessful in up to 20% of cases, and often requires several shocks of up to 360 J. Based on the success with biphasic shock waveform in converting ventricular fibrillation, it was postulated that biphasic shocks would allow cardioversion with lower energy. In a international multicenter, double-blind, randomized trial of 203 patients, damped sine wave monophasic shocks were compared with impedance-compensated truncated exponential biphasic waveform shocks. Patients received up to five shocks: 100 J, 150 J, 200 J, a fourth shock at maximum output for the initial waveform (200 J biphasic, 360 J monophasic) and a final cross-over shock at maximum output of the alternate waveform. For each energy level, the biphasic waveform compared favorably to the monophasic waveform in successful cardioversion (100 J: 60% versus 22%, P < 0.0001; 150 J: 77% versus 44%, p < 0.0001; 200 J: 90% versus 53%, p < 0.0001). Success with 200 J biphasic was equivalent to 360 J monophasic shock (91% versus 85%, p = 0.29). Patients randomized to biphasic waveform required fewer shocks and lower total energy delivered; in addition, this waveform was associated with less dermal injury and no blistering. Biphasic shocks converted AF present for less than 48 hours with 80% efficacy, but conversion of AF present for more than 48 hours and more than 1 year the success rate was only 63 and 20%, respectively. The results of this study is similar to other investigations comparing biphasic and monophasic shock waveforms for conversion of atrial fibrillation. We recommend starting with biphasic energy of 100 J for atrial fibrillation of less than 48 hours duration, but using higher energies (150 J, 200 J or greater) when AF has been present for longer periods.

  5. Biopolymer-stabilized Pt nanoparticles colloid: a highly active and recyclable catalyst for biphasic catalysis

    NASA Astrophysics Data System (ADS)

    Wang, Yujia; Shen, Yueyue; Qiu, Yunfei; Zhang, Ting; Liao, Yang; Zhao, Shilin; Ma, Jun; Mao, Hui

    2016-10-01

    Noble metal nanoparticles are promising candidates to replace conventional bulk counterparts owing to their high activity and selectivity. To enable catalyst recovery, noble metal nanoparticles are often supported onto solid matrices to prepare heterogeneous catalyst. Although recycle of noble metal nanoparticles is realized by heterogenization, a loss of activity is usually encountered. In the present investigation, Pt nanoparticles with tunable particle size (1.85-2.80 nm) were facilely prepared by using polyphenols as amphiphilic stabilizers. The as-prepared Pt nanoparticles colloid solution could be used as highly active catalyst in aqueous-organic biphasic catalysis. The phenolic hydroxyls of polyphenols could constrain Pt nanoparticles in aqueous phase, and simultaneously, the aromatic scaffold of polyphenols ensured effective interactions between substrates and Pt nanoparticles. As a consequence, the obtained polyphenols-stabilized Pt nanoparticles exhibited high activity and cycling stability in biphasic hydrogenation of a series of unsaturated compounds. Compared with conventional heterogeneous Pt-C and Pt-Al2O3 catalysts, polyphenols-stabilized Pt nanoparticles showed obvious advantage both in activity and cycling stability.

  6. Biphasic synovial sarcoma of the abdominal wall.

    PubMed

    Vera, Jesús; García, María-Dolores; Marigil, Miguel; Abascal, Manuel; Lopez, Jose-Ignacio; Ligorred, Luis

    2006-09-01

    Synovial sarcoma arising in the abdominal wall is a rare tumor. We report a case of a 38-year-old man who complained of abdominal pain. Physical examination revealed a firm mobile mass, 25 cm in diameter, in the left lower abdominal wall. The tumor was first thought to be a sarcoma arising from the omentum or mesentery. During surgery, a large tumor was found attached to the inner surface of the abdominal wall and compressing the gastrointestinal tract. On microscopic examination the tumor corresponded to a biphasic synovial sarcoma immunoreactive for cytokeratins (AE1/AE3, 7 and 19), epithelial membrane antigen and carcinoembryonic antigen in the epithelial tumor cells, for E-cadherin especially in their glandular structure, vimentin, CD99, and CD56 in the spindle cell component and for bcl-2 protein. The tumor recurred at the same site, and clinical course progressed to death 3 months after the initial diagnosis.

  7. Benign notochordal cell tumors.

    PubMed

    Martínez Gamarra, C; Bernabéu Taboada, D; Pozo Kreilinger, J J; Tapia Viñé, M

    2017-08-01

    Benign notochordal cell tumors (TBCN) are lesions with notochordal differentiation which affect the axial skeleton. They are characterized by asymptomatic or non-specific symptomatology and are radiologically unnoticed because of their small size, or because they are mistaken with other benign bone lesions, such as vertebral hemangiomas. When they are large, or symptomatic, can be differential diagnosis with metastases, primary bone tumors and chordomas. We present a case of a TBCN in a 50-year-old woman, with a sacral lesion seen in MRI. A CT-guided biopsy was scheduled to analyze the lesion, finding that the tumor was not clearly recognizable on CT, so the anatomical references of MRI were used to select the appropriate plane. The planning of the approach and the radio-pathological correlation were determinant to reach the definitive diagnosis. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  8. [Large benign prostatic hiperplasia].

    PubMed

    Soria-Fernández, Guillermo René; Jungfermann-Guzman, José René; Lomelín-Ramos, José Pedro; Jaspersen-Gastelum, Jorge; Rosas-Nava, Jesús Emmanuel

    2012-01-01

    the term prostatic hyperplasia is most frequently used to describe the benign prostatic growth, this being a widely prevalent disorder associated with age that affects most men as they age. The association between prostate growth and urinary obstruction in older adults is well documented. large benign prostatic hyperplasia is rare and few cases have been published and should be taken into account during the study of tumors of the pelvic cavity. we report the case of an 81-year-old who had significant symptoms relating to storage and bladder emptying, with no significant elevation of prostate specific antigen. this is a rare condition but it is still important to diagnose and treat as it may be related to severe obstructive uropathy and chronic renal failure. In our institution, cases of large prostatic hyperplasia that are solved by suprapubic adenomectomy are less than 3%.

  9. Benign cutaneous Degos' disease.

    PubMed

    Ojeda Cuchillero, R M; Sánchez Regaña, M; Umbert Millet, P

    2003-03-01

    Malignant atrophic papulosis is a rare systemic vaso-occlusive disorder characterized by thrombosis of vessels of the dermis, gastrointestinal tract, central nervous system and, occasionally, other organs. Cutaneous lesions consist of erythematous, dome-shaped papules that develop a central area of necrosis to leave a porcelain-like scar. The most accepted theory of pathogenesis is based on endothelial cell damage. There is no effective treatment of the disease. We describe a 26-year-old man with Degos' disease, a diagnosis based on the clinical and histologic pattern of skin lesions. The good response to antiplatelet therapy and the absence of systemic involvement over 8 years' follow-up is noteworthy. We believe that this case represents the benign form of the disease, typically referred to as benign cutaneous Degos' disease.

  10. [Benign vocal fold lesions].

    PubMed

    Pickhard, A; Reiter, R

    2013-05-01

    Benign vocal fold lesions are grouped in lesions arising from the epithelium like papillomas, lesions affecting the Reinke's space (nodules, polyps, cysts, Reinkes's edema as a form of chronic laryngitis) and lesions affecting the arytenoid (granulomas). A multifactorial genesis is assumed. Main symptoms are dysphonia and hyperfunctional vocal behavior that might also be a cause of these lesions. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Environmentally Benign Pyrotechnic Delays

    DTIC Science & Technology

    2012-06-01

    jay.poret@us.army.mil † School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA ABSTRACT Pyrotechnic delays are used in...benign formulations are described. The delay time of the new system is easily tunable. These compositions will consistently function in aluminum ...tunable. These compositions will consistently function in aluminum housings which is generally difficult for delay compositions due to extreme thermal

  12. Benign familial hyperphosphatasemia

    SciTech Connect

    Siraganian, P.A.; Mulvihill, J.J.; Mulivor, R.A.; Miller, R.W. )

    1989-03-03

    Elevated alkaline phosphatase activity in serum suggests bone or liver disease or a neoplasm but can also indicate pregnancy or another benign condition. A family with benign hyperphosphatasemia was studied to elucidate the genetics and enzyme defect. Serum total alkaline phosphatase activity was greater than the population mean in all six family members, and more than 7 SDs above the mean in two of four offspring. Monoclonal antibodies to three alkaline phosphatase isoenzymes, intestinal, placental, and tissue nonspecific demonstrated markedly increased intestinal alkaline phosphatase levels in all family members and significantly elevated liver/bone/kidney activity in the two offspring. Guanidine hydrochloride denaturation of the liver/bone/kidney component showed high alkaline phosphatase activity from liver in both siblings and from bone in one. The mode of inheritance in this family is obscure, but a complex regulation of the products of two different alkaline phosphatase genes seems likely. Steps toward diagnosis are suggested. Early recognition of this benign biochemical abnormality should help to avoid unnecessary diagnostic tests.

  13. Novel Measurements of Aerosol Particle Interfaces Using Biphasic Microfluidics

    NASA Astrophysics Data System (ADS)

    Metcalf, A. R.; Dutcher, C. S.

    2014-12-01

    Secondary organic aerosol (SOA) particles are nearly ubiquitous in the atmosphere and yet there remains large uncertainties in their formation processes and ambient properties. These particles are complex microenvironments, which can contain multiple interfaces due to internal aqueous-organic phase partitioning and to the external liquid-vapor surface. These aerosol interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which organic vapors interact with the ambient aerosol. Aerosol interfaces affect particle internal structure, species uptake, equilibrium partitioning, activation to cloud condensation or ice nuclei, and optical properties. For example, organic thin films can shield the core of the aerosol from the ambient environment, which may disrupt equilibrium partitioning and mass transfer. To improve our ability to accurately predict the fate of SOA in the atmosphere, we must improve our knowledge of aerosol interfaces and their interactions with the ambient environment. Few technologies exist to accurately probe aerosol interfaces at atmospherically-relevant conditions. In this talk, a novel method using biphasic microscale flows will be introduced for generating, trapping, and perturbing complex interfaces at atmospherically relevant conditions. These microfluidic experiments utilize high-speed imaging to monitor interfacial phenomena at the microscale and are performed with phase contrast and fluorescence microscopy on a temperature-controlled inverted microscope stage. From these experiments, interfacial thermodynamic properties such as surface tension, rheological properties such as interfacial moduli, and kinetic properties such as mass transfer coefficients can be measured or inferred. Chemical compositions of the liquid phases studied here span a range of viscosities and include electrolyte and water soluble organic acid species often observed in the atmosphere, such as mixtures

  14. Benign paroxysmal positional vertigo.

    PubMed

    von Brevern, Michael

    2013-07-01

    Benign paroxysmal positional vertigo (BPPV) is the most common and the most effectively treated vestibular disorder. The prevailing pathomechanism is canalolithiasis, which is otoconia falling in one of the semicircular canals where they move in response to changes of the head position, triggering excitation of the vestibular receptors of the affected canal. In the majority of patients with BPPV, the posterior canal is affected by canalolithiasis and there are two highly effective therapeutic maneuvers for treatment. About 20% of patients present with lithiasis of the horizontal or anterior canal. The author focuses on recent advances in diagnosis and treatment of the more rare variants of BPPV.

  15. Kinetics of Horseradish Peroxidase-Catalyzed Nitration of Phenol in a Biphasic System.

    PubMed

    Kong, Mingming; Zhang, Yang; Li, Qida; Dong, Runan; Gao, Haijun

    2017-02-28

    The use of peroxidase in the nitration of phenols is gaining interest as compared with traditional chemical reactions. We investigated the kinetic characteristics of phenol nitration catalyzed by horseradish peroxidase (HRP) in an aqueous-organic biphasic system using n-butanol as the organic solvent and NO2(-) and H2O2 as substrates. The reaction rate was mainly controlled by the reaction kinetics in the aqueous phase when appropriate agitation was used to enhance mass transfer in the biphasic system. The initial velocity of the reaction increased with increasing HRP concentration. Additionally, an increase in the substrate concentrations of phenol (0-2 mM in organic phase) or H2O2 (0-0.1 mM in aqueous phase) enhanced the nitration efficiency catalyzed by HRP. In contrast, high concentrations of organic solvent decreased the kinetic parameter Vmax/Km. No inhibition of enzyme activity was observed when the concentrations of phenol and H2O2 were at or below 10 mM and 0.1 mM, respectively. On the basis of the peroxidase catalytic mechanism, a double-substrate ping-pong kinetic model was established. The kinetic parameters were Km(H2O2)= 1.09 mM, Km(PhOH) = 9.45 mM, and Vmax = 0.196 mM/min. The proposed model was well fit to the data obtained from additional independent experiments under the suggested optimal synthesis conditions. The kinetic model developed in this paper lays a foundation for further comprehensive study of enzymatic nitration kinetics.

  16. Acute encephalopathy with biphasic seizures and late reduced diffusion

    PubMed Central

    Yadav, Saroj S.; Lawande, Malini A.; Kulkarni, Shilpa D.; Patkar, Deepak A.

    2013-01-01

    Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is a syndrome of encephalopathy characterized by biphasic seizures and altered consciousness in the acute stage followed in the subacute stage by restricted diffusion in the subcortical white matter on magnetic resonance imaging. The etiology of AESD has been attributed to viral infection like influenza A and human herpes virus 6. The exact pathogenesis of AESD is uncertain. Here we report a case of AESD, diagnosed based on clinicoradiological correlation. PMID:23772250

  17. Vorticity banding in biphasic polymer blends.

    PubMed

    Caserta, Sergio; Guido, Stefano

    2012-11-27

    Pattern formation under the action of flow is a subject of considerable scientific interest with applications going from microfluidics to granular materials. Here, we present a systematic investigation of shear-induced banding in confined biphasic liquid-liquid systems, i.e., formation of alternating regions of high and low volume fraction of droplets in a continuous phase (shear bands). This phenomenon is investigated in immiscible polymer blends sheared in a sliding parallel plate flow cell. Starting from a spatially uniform distribution of droplets, the formation of bands aligned along the flow direction is observed, eventually leading to an almost complete separation between droplet-rich and continuous phase regions. The initial band size is related to the gap dimension; the merging of bands and consequent spacing reduction has also been observed for long times. Shear banding is only observed when the viscosity of the dispersed phase is lower as compared to the continuous phase and in a limited range of the applied shear rate. Rheological measurements show that band formation is associated with a viscosity decrease with respect to the homogeneous case, thus implying that system microstructure is somehow evolving toward reduced viscous dissipation under flow.

  18. Benign follicular tumors*

    PubMed Central

    Tellechea, Oscar; Cardoso, José Carlos; Reis, José Pedro; Ramos, Leonor; Gameiro, Ana Rita; Coutinho, Inês; Baptista, António Poiares

    2015-01-01

    Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients. PMID:26734858

  19. Stabilized rhodium(0) nanoparticles: a reusable hydrogenation catalyst for arene derivatives in a biphasic water-liquid system.

    PubMed

    Schulz, J; Roucoux, A; Patin, H

    2000-02-18

    A colloidal system based on an aqueous suspension of rhodium(o) nanoparticles proved to be an efficient catalyst for the hydrogenation of arene derivatives under biphasic conditions. The rhodium nanoparticles (2-2.5 nm) were synthesized by the reduction of RhCl3 x 3H2O with sodium borohydride and were stabilized by highly water-soluble N-alkyl-N-(2-hydroxyethyl)ammonium salts (HEA-Cn). These surfactant molecules were characterized by measurements of the surface tension and the aqueous dispersions with rhodium were observed by transmission electron cryomicroscopy. The catalytic system is efficient under ultramild conditions, namely room temperature and 1 atm H2 pressure. The aqueous phase which contains the protected rhodium(0) colloids can be reused without significant loss of activity. The microheterogeneous behavior of this catalytic system was confirmed on a mercury poisoning experiment.

  20. Superabsorbent biphasic system based on poly(lactic acid) and poly(acrylic acid)

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Pandini, Stefano; Baldi, Francesco; Bignotti, Fabio

    2016-05-01

    In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production.

  1. A new rhenanite (beta-NaCaPO(4)) and hydroxyapatite biphasic biomaterial for skeletal repair.

    PubMed

    Jalota, Sahil; Bhaduri, Sarit B; Tas, A Cuneyt

    2007-02-01

    Biphasic beta-rhenanite (beta-NaCaPO(4))-hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)) biomaterials were prepared by using a one-pot, solution-based synthesis procedure at the physiological pH of 7.4, followed by low-temperature (300-600 degrees C) calcination in air for 6 h. Calcination was for the sole purpose of crystallization. An aqueous solution of Ca(NO(3))(2). 4H(2)O was rapidly added to a solution of Na(2)HPO(4) and NaHCO(3), followed by immediate removal of gel-like, poorly-crystallized precursor precipitates from the mother liquors of pH 7.4. Freeze-dried precursors were found to be nanosize with an average particle size of 45 nm and a surface area of 128 m(2)/g. Upon calcination in air, precursor powders crystallized into biphasic (60% HA-40% rhenanite) biomaterials, while retaining their submicron particle sizes and high surface areas. beta-rhenanite is a high solubility sodium calcium phosphate phase. Samples were characterized by XRD, FTIR, SEM, TEM, ICP-AES, TG, DTA, DSC, and surface area measurements.

  2. A Substrate Fed-Batch Biphasic Catalysis Process for the Production of Natural Crosslinking Agent Genipin with Fusarium solani ACCC 36223.

    PubMed

    Zhu, Yuyao; Zhao, Botao; Huang, Xiaode; Chen, Bin; Qian, Hua

    2015-06-01

    The natural crosslinking agent genipin has been applied widely in biomedicines and foods nowadays. Because of the special hemiacetal ring structure in its molecule, it can only be prepared by hydrolysis of geniposide according to biocatalysis. In this research, strategies including aqueous-organic biphasic catalysis and substrate fed-batch mode were adopted to improve the biocatalysis process of genipin. A 10 L ethyl acetate-aqueous biphasic system with geniposide fed-batch led to a satisfying genipin yield. With Fusarium solani ACCC 36223, 15.7 g/l genipin in the ethyl acetate phase was obtained, corresponding to space-time yields of 0.654 g l(-1) h(-1).

  3. Production of types A and B spores of Clostridium botulinum by the biphasic method: effect on spore population, radiation resistance, and toxigenicity.

    PubMed

    Anellis, A; Berkowitz, D; Kemper, D; Rowley, D B

    1972-04-01

    Spores of three strains each of type A and type B Clostridium botulinum were produced both by a biphasic (solid medium overlaid with an aqueous phase) and by a "conventional" (deep broth culture) procedure. Sporogenesis by the biphasic system was more rapid, convenient, and economical, and yielded as many or more heat-resistant (80 C, 10 min) spores per milliliter as by the conventional technique. Of several aqueous phases [thiamine-hydrochloride, yeast extract, (NH(4))(2)SO(4)] tested with strain 62A, the highest spore colony counts were obtained with 2.0% (NH(4))(2)SO(4). The six strains formed maximum spore numbers in 5 to 6 days of incubation. Spores produced by the two methods had essentially equal radiation resistances (D and lag values), and their subcultures gave similar toxin titers (LD(50) values).

  4. [Benign myoepithelioma of the lung].

    PubMed

    El Mezni, F; Zeddini, A; Hamzaoui, A; Ismail, O; Ghrairi, H; Ben Miled, K; Smati, B; Kilani, T

    2004-11-01

    Benign myoepithelioma of the lung is a benign tumor caused by proliferating myoepithelial cells with no ductal component. These tumors are exceptional: only three cases have been reported in the literature. We report a fourth case in a 37-year-old woman at 8 months gestation. Pathological proof of diagnosis was obtained.

  5. Interaction between hydroxypropyl methylcellulose and biphasic calcium phosphate after steam sterilisation: capillary gas chromatography studies

    PubMed Central

    Bourges, Xavier; Schmitt, Michel; Amouriq, Yves; Daculsi, Guy; Legeay, Gilbert; Weiss, Pierre

    2001-01-01

    The purpose of this study was to check the chemical stability of an injectable bone substitute (IBS) composed of a 50/50 w/w mixture of a 2.92% hydroxypropyl methylcellulose (HPMC) solution in deionised water containing biphasic calcium phosphate (BCP) granules (60% hydroxyapatite/40% β-tricalcium phosphate w/w). After separation of the organic and mineral phases, capillary gas chromatography (GC) was used to study the possible modification of HPMC due to the contact with BCP granules following steam sterilisation and 32 days of storage at room temperature. HPMC was extracted from IBS in aqueous medium, and a dialytic method was then use to extract calcium phosphate salts from HPMC. The percentage of HPMC extracted from BCP was 98.5% ± 0.5% as measured by a UV method. GC showed no chemical modifications after steam sterilisation and storage. PMID:11556737

  6. Light controlled reversible inversion of nanophosphor-stabilized Pickering emulsions for biphasic enantioselective biocatalysis.

    PubMed

    Chen, Zhaowei; Zhou, Li; Bing, Wei; Zhang, Zhijun; Li, Zhenhua; Ren, Jinsong; Qu, Xiaogang

    2014-05-21

    In this work, by utilizing photochromic spiropyrans conjugated upconversion nanophosphors, we have successfully prepared NIR/visible light tuned interfacially active nanoparticles for the formulation of Pickering emulsions with reversible inversion properties. By loading a model enantioselective biocatalytic active bacteria Alcaligenes faecalis ATCC 8750 in the aqueous phase, we demonstrated for the first time that the multifunctional Pickering emulsion not only highly enhanced its catalytic performance but also relieved the substrate inhibition effect. In addition, product recovery, and biocatalysts and colloid emulsifiers recycling could be easily realized based on the inversion ability of the Pickering emulsion. Most importantly, the utilization of NIR/visible light to perform the reversible inversion without any chemical auxiliaries or temperature variation showed little damage toward the biocatalysts, which was highlighted by the high catalytic efficiency and high enantioselectivity even after 10 cycles. The NIR/visible light controlled Pickering emulsion showed promising potential as a powerful technique for biocatalysis in biphasic systems.

  7. Perfluorinated quaternary ammonium salts of polyoxometalate anions: Fluorous biphasic oxidation catalysis with and without fluorous solvents

    SciTech Connect

    Maayan, Galia; Fish, Richard H.; Neumann, Ronny

    2003-05-28

    Perfluorinated quaternary ammonium cations, [CF{sub 3}(CF{sub 2}){sub 7}(CH{sub 2}){sub 3}]{sub 3}CH{sub 3}N{sup +} (RFN{sup +}), were synthesized and used as counter cations for the [WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW{sub 9}O{sub 34}){sub 2}]{sup 12-} (M = Mn(II), Zn(II)), polyoxometalate. The (RFN{sup +}){sub 12}[WZnM{sub 2}(H{sub 2}O){sub 2}(ZnW9O{sub 34}){sub 2}] compounds were fluorous biphasic catalysts for alcohol and alkenol oxidation, and alkene epoxidation with aqueous hydrogen peroxide. Reaction protocols with or without a fluorous solvent were tested. The catalytic activity and selectivity was affected both by the hydrophobicity of the solvent and the substrate.

  8. Assessment of balanced biphasic defibrillation waveforms in transthoracic atrial cardioversion.

    PubMed

    Krasteva, V; Trendafilova, E; Cansell, A; Daskalov, I

    2001-01-01

    Various electrical pulses have been used for defibrillation. The monophasic damped sinusoid waveform, initiated in 60 s, was adopted in virtually all defibrillators. Biphasic pulses were introduced recently, achieving success with less energy. A biphasic exponential waveform was modelled with 4 ms duration per phase with a balanced 3:1 ratio of the first to second phase peak voltages and implemented in a defibrillator. A version obtained by chopping the pulses with a 5 kHz frequency was also used. It was hypothesized that the modelled transmembrane voltage decay time is a parameter that could be associated with successful defibrillation. The results of cardioversion for two groups of patients with the 'classic' monophasic waveform and with the biphasic pulses were compared. The mean efficient energy with the damped sinusoid was 205 +/- 85 J, versus 88 +/- 43 J with the biphasic pulses, yielding a ratio of 2.32 (1.92 to 3.2 for fibrillation and flutter, respectively). An acceptable agreement between model data and clinical results was found. The transmembrane voltage decay time ratios for monophasic versus biphasic pulses was in the approximate range of 2.5 to 3.5.

  9. Biphasic nanofibrous constructs with seeded cell layers for osteochondral repair.

    PubMed

    Jin, Guang-Zhen; Kim, Jung-Ju; Park, Jeong-Hui; Seo, Seog-Jin; Kim, Joong-Hyun; Lee, Eun-Jung; Kim, Hae-Won

    2014-11-01

    Biphasic scaffolds have gained increasing attention for the regeneration of osteochondral interfacial tissue because they are expected to effectively define the interfacial structure of tissue that comprises stratified cartilage with a degree of calcification. Here, we propose a biphasic nanofiber construct made of poly(lactide-co-caprolactone) (PLCL) and its mineralized form (mPLCL) populated with cells. Primary rat articular chondrocytes (ACs) and bone marrow-derived mesenchymal stem cells (MSCs) were cultured on the layers of bare PLCL and mPLCL nanofibers, respectively, for 7 days, and the biphasic cell-nanofiber construct was investigated at 4 weeks after implantation into nude mice. Before implantation, the ACs and MSCs grown on each layer of PLCL and mPLCL nanofibers exhibited phenotypes typical of chondrocytes and osteoblasts, respectively, under proper culture conditions, as analyzed by electron microscopy, histological staining, cell growth kinetics, and real-time polymerase chain reaction. The biphasic constructs also showed the development of a possible formation of cartilage and bone tissue in vivo. Results demonstrated that the cell-laden biphasic nanofiber constructs may be useful for the repair of osteochondral interfacial tissue structure.

  10. Interfacial Tensions of Aged Organic Aerosol Particle Mimics Using a Biphasic Microfluidic Platform.

    PubMed

    Metcalf, Andrew R; Boyer, Hallie C; Dutcher, Cari S

    2016-02-02

    Secondary organic aerosol (SOA) particles are a major component of atmospheric particulate matter, yet their formation processes and ambient properties are not well understood. These complex particles often contain multiple interfaces due to internal aqueous- and organic-phase partitioning. Aerosol interfaces can profoundly affect the fate of condensable organic compounds emitted into the atmosphere by altering the way in which ambient organic vapors interact with suspended particles. To accurately predict the evolution of SOA in the atmosphere, we must improve our understanding of aerosol interfaces. In this work, biphasic microscale flows are used to measure interfacial tension of reacting methylglyoxal, formaldehyde, and ammonium sulfate aqueous mixtures with a surrounding oil phase. Our experiments show a suppression of interfacial tension as a function of organic content that remains constant with reaction time for methylglyoxal-ammonium sulfate systems. We also reveal an unexpected time dependence of interfacial tension over a period of 48 h for ternary solutions of both methylglyoxal and formaldehyde in aqueous ammonium sulfate, indicating a more complicated behavior of surface activity where there is competition among dissolved organics. From these interfacial tension measurements, the morphology of aged atmospheric aerosols with internal liquid-liquid phase separation is inferred.

  11. Benign Bilateral Adenomyoepithelioma of the Mammary Gland in a Ring-tailed Lemur (Lemur catta).

    PubMed

    Suárez-Bonnet, A; Grau-Bassas, E Rodríguez; Herráez, P; Quesada-Canales, O; Priestnall, S L; de Los Monteros, A Espinosa

    Naturally occurring mammary tumours are uncommon in prosimians. A 20-year-old female ring-tailed lemur (Lemur catta) developed bilateral enlargement of the mammary glands. Surgical removal revealed that both masses were comprised of multiple nodules and cystic areas that entirely replaced the normal glands. Histologically, a benign neoplastic biphasic cellular proliferation, composed of luminal-epithelial and basal-myoepithelial components, was identified. Immunohistochemical analysis for expression of cytokeratin (CK) AE1/AE3, CK7, CK5 + 8, CK14, vimentin, p63 and 14-3-3σ highlighted the biphasic nature of the neoplasm. A low mitotic count, low Ki67 labelling index, expression of oestrogen receptor-α, lack of expression of human epidermal growth factor receptor and a 3-year disease-free period without recurrence supported the benign nature of the tumour. Macroscopically, histologically and immunohistochemically this neoplasm resembled benign adenomyoepithelioma of the breast in women. This is the first complete report of a naturally occurring mammary tumour in a ring-tailed lemur. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Biphasic nanoparticles made by electrified jetting

    NASA Astrophysics Data System (ADS)

    Lahann, Joerg

    2005-03-01

    Nano-colloids have recently attracted intense attention due to unique properties that are distinctly different from bulk solid-state materials; including unique magnetic, electronic, optical, chemical, and biological characteristics. The vision that these nano-objects could essentially act as functional components in novel device generations, which ``magically'' assemble following a master blueprint void any human manipulation, has resulted in a new ``gold rush'' in materials science. These concepts have results in the synthesis of a multitude of nano-objects, such as nano-wires, nano-rods, nano-disks, or nano-prisms.^ Recently, nano-particles with anisotropic materials distributions (biphasic nano-particles) moved in the focus of research. Our approach differs fundamentally from the above-mentioned methods in that it takes advantage of electrified polymer jets to create anisotropic materials distributions in nano-objects. jetting is a process to generate liquid jets by use of electrostatic forces. It is well-known that high electrical potentials (typically several thousand volts) applied between the jetting liquids that are fed through a capillary and a collecting substrate will induce jetting of a charged liquid. The differences in the final morphologies from similar processes are mainly determined by the properties of the jetting liquids and the process parameters. transmission electron microscopy, scanning electron microscopy, and scanning laser confocal microscopy, we demonstrate the applicability of the process to control size, shape, and materials distribution at the nanoscale. The resulting anisotropic nanoparticles may have potential applications for targeted drug delivery or as electro-rehological fluids. a) F. M. Van der Kooij, K. Kassapidou and H. N. W. Lekkerkerker, Liquid crystal phase transitions in suspensions of polydisperse plate-like particles, Nature 406, 868 (2000); b) C. A. Mirkin, R. L. Letsinger, R. C. Mucic and J. J. Storhoff, A DNA

  13. In situ synthesis of magnesium-substituted biphasic calcium phosphate and in vitro biodegradation

    SciTech Connect

    Kim, Tae-Wan; Lee, Hyeong-Shin; Kim, Dong-Hyun; Jin, Hyeong-Ho; Hwang, Kyu-Hong; Lee, Jong Kook; Park, Hong-Chae; Yoon, Seog-Young

    2012-09-15

    Highlights: ► Mg–BCP were successfully prepared through in situ aqueous co-precipitation method. ► The amount of β-TCP phase was changed with the magnesium substitution level. ► The substitution of magnesium led to a decrease in the unit cell volume. ► Mg–BCP could be able to develop a new apatite phase on the surface faster than BCP. -- Abstract: In situ preparation of magnesium (Mg) substituted biphasic calcium phosphate (BCP) of hydroxyapatite (HAp)/β-tricalcium phosphate (β-TCP) were carried out through aqueous co-precipitation method. The concentrations of added magnesium were varied with the calcium in order to obtain constant (Ca + Mg)/P ratios of 1.602. X-ray diffraction (XRD) and Fourier transformed infrared (FTIR) spectroscopy were used to characterize the structure of synthesized magnesium substituted BCP powders. The results have shown that substitution of magnesium in the calcium deficient apatites revealed the formation of biphasic mixtures of different HAp/β-TCP ratios after heating at 1000 °C. The ratios of the formation of phase mixtures were dependent on the content of magnesium. After immersing in Hanks’ balanced salt solution (HBSS) for 1 week, 1 wt% magnesium substituted BCP powders were degraded and precipitation started to be formed with small granules consisting of number of flake-like crystal onto the surface of synthesized powders. On the other hand, in the case of pure BCP powders, the formation of new precipitates was detected after immersion in HBSS for 2 weeks. On the basis of these results, magnesium substituted BCP could be able to develop a new apatite phase on the surface in contact with physiological fluids faster than BCP does. In addition, the retention time to produce the new apatite phase in implantation operation for the BCP powder could be controlled by the amount of magnesium substitution.

  14. Benign prostatic hyperplasia

    PubMed Central

    2006-01-01

    Introduction Symptomatic benign prostatic hyperplasia (BPH) may affect up to 30% of men in their early 70s, causing urinary symptoms of bladder outlet obstruction. Symptoms can improve without treatment, but the usual course is a slow progression of symptoms, with acute urinary retention occurring in 1-2% of men with BPH per year. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of medical, surgical, and herbal treatments? We searched: Medline, Embase, The Cochrane Library and other important databases up to May 2005 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 43 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: 5 alpha-reductase inhibitors, alpha-blockers, beta-sitosterol plant extract, less-invasive surgical techniques, pygeum africanum, rye grass pollen extract, saw palmetto plant extracts, transurethral microwave thermotherapy, transurethral needle ablation, and transurethral resection.

  15. Progress on the biphase turbine at Cerro Prieto

    SciTech Connect

    Cerini, D.; Hays, L.; Studhalter, W.

    1997-12-31

    The status of a Biphase turbine power plant being installed at the Cerro Prieto geothermal field is presented. The major modules for the power plant are completed except for a back pressure steam turbine. The power plant will be started in April 1997 with the Biphase turbine alone followed by the addition of the steam turbine module two months later. The current power plant performance level is 2780 kWe due to a decline in the well. An increase in power output to 4060 kWe by adding the flow from another well is planned. The addition of five Biphase power plants with a total power output of 21.2 megawatts is described.

  16. Biphasic materials for bone grafting and hyperthermia treatment of cancer.

    PubMed

    Arcos, D; del Real, R P; Vallet-Regí, M

    2003-04-01

    Three biphasic materials have been synthesized from a magnetic glass-ceramic (Si-Ca-Fe) and a bioactive sol-gel glass (Si-P-Ca). The ratios of glass-ceramic:sol-gel glass used in this work were 1:1, 2:1, and 5:1. These materials show bioactive and magnetic properties and can be used as thermoseeds for hyperthermia treatment of bone tumors. The sol-gel glass content affects the textural properties of the glass-ceramic, giving rise to porosity, which plays a fundamental role in the formation of an apatite-like layer on the surface. On the other hand, as the sol-gel glass content increases, the magnetic properties change due to the diffusion of Fe ions to the glassy phases of the biphasic materials. The biphasic nature of these materials allows the changing of both properties, depending on the requirements of the patient.

  17. Microfluidic electrospinning of biphasic nanofibers with Janus morphology

    PubMed Central

    Srivastava, Yasmin; Marquez, Manuel; Thorsen, Todd

    2009-01-01

    In this paper a method of electrospinning conducting and nonconducting biphasic Janus nanofibers using microfluidic polydimethylsiloxane (PDMS)-based manifolds is described. Key benefits of using microfluidic devices for nanofiber synthesis include rapid prototyping, ease of fabrication, and the ability to spin multiple Janus fibers in parallel through arrays of individual microchannels. Biphasic Janus nanofibers of polyvinylpyrrolidone (PVP)+polypyrrole (PPy)∕PVP nanofibers with an average diameter of 250 nm were successfully fabricated using elastomeric microfluidic devices. Fiber characterization and confirmation of the Janus morphology was subsequently carried out using a combination of scanning electron microscopy, energy dispersion spectroscopy, and transmission electron microscopy. PMID:19693390

  18. Case Report: Multifocal biphasic squamoid alveolar renal cell carcinoma

    PubMed Central

    Lopez, Jose Ignacio

    2016-01-01

    A multifocal biphasic squamoid alveolar renal cell carcinoma in a 68-year-old man is reported. Four different peripheral tumor nodules were identified on gross examination. A fifth central tumor corresponded to a conventional clear cell renal cell carcinoma. Biphasic squamoid alveolar renal cell carcinoma is a rare tumor that has been very recently characterized as a distinct histotype within the spectrum of papillary renal cell carcinoma. Immunostaining with cyclin D1 seems to be specific of this tumor subtype. This is the first reported case with multifocal presentation. PMID:27158455

  19. Benign phyllodes tumor with tubular adenoma-like epithelial component in FNAC: A diagnostic pitfall.

    PubMed

    Panda, Kishori M

    2016-01-01

    Benign phyllodes tumor (BPT) is a biphasic neoplasm composed of bland stromal and epithelial elements. Cytologic diagnostic criteria of BPT, though documented in the literature, diagnostic pitfalls in fine-needle aspiration cytology (FNAC) may occur due to sampling error, high cellularity, ductal hyperplasia, paucity of stromal component, and occasional dissociation of epithelial cells. Here, we describe a case of BPT diagnosed by histology in a 19-year-old female, where FNAC features were inconclusive due to paucity of stromal component, predominance of tubular adenoma-like epithelial component, and due to the presence of other overlapping features with fibroadenoma.

  20. Benign phyllodes tumor with tubular adenoma-like epithelial component in FNAC: A diagnostic pitfall

    PubMed Central

    Panda, Kishori M

    2016-01-01

    Benign phyllodes tumor (BPT) is a biphasic neoplasm composed of bland stromal and epithelial elements. Cytologic diagnostic criteria of BPT, though documented in the literature, diagnostic pitfalls in fine-needle aspiration cytology (FNAC) may occur due to sampling error, high cellularity, ductal hyperplasia, paucity of stromal component, and occasional dissociation of epithelial cells. Here, we describe a case of BPT diagnosed by histology in a 19-year-old female, where FNAC features were inconclusive due to paucity of stromal component, predominance of tubular adenoma-like epithelial component, and due to the presence of other overlapping features with fibroadenoma. PMID:28028339

  1. A giant benign clear cell hidradenoma on the anterior trunk.

    PubMed

    Demirci, Gulsen Tukenmez; Atis, Guldehan; Altunay, Ilknur Kivanç; Sakiz, Damlanur

    2011-10-05

    Clear cell hidradenoma (CCH) is an uncommon variant of benign cutaneous adnexal tumors. These tumors are clinically asymptomatic, solitary dermal nodules. They occur most frequently on the scalp, face abdomen and extremities. Growth is slow and malignant change is rare. 45-year-old woman presented with a nodule which had begun 4 years ago as a small nodular asymptomatic lesion and had a central ulceration and a minimal hemorrhagic discharge on her anterior abdomen wall. On dermatologic examination there was a 6.5×5×4 cm non-tender, soft reddish purple nodule, with lobular appearance and ulceration. In the laboratory investigations, all hematologic and biochemical tests were normal. A computed tomography (CT) scan demonstrated a cystic tumor with lobulated contour with contrast enhancement. The lesion was excised totally. In histopathological examination, the tumor was composed of biphasic smaller dark polygonal cells and larger clear cells and coarse nuclear chromatine. There were duct like structures. Immunohistochemical investigation was done for the suspicion of malignancy. Cytoplasm of clear cells and of duct like structures showed PAS-positive and d-PAS resistant staining. There was a positive reaction to epithelial membrane antigen and carcinoembryonic antigen. The mitotic index in Ki 67 examination was low. All these findings confirmed the diagnosis of benign CCH.

  2. Probing the limit of magnesium uptake by β-tricalcium phosphate in biphasic mixtures formed from calcium deficient apatites

    SciTech Connect

    Kumar, P. Nandha; Mishra, Sandeep K.; Kannan, S.

    2015-11-15

    A series of magnesium doped non-stoichiometric calcium deficient apatites were synthesized through an aqueous precipitation route. The resultant structural changes during heat treatment were investigated by X-ray diffraction, Raman and FT-IR spectroscopy and Rietveld refinement. The results confirmed the formation of biphasic mixtures comprising Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} and β-Ca{sub 3}(PO{sub 4}){sub 2} after heat treatment at 1000 °C with the preferential occupancy of Mg{sup 2+} at the crystal lattice of β-Ca{sub 3}(PO{sub 4}){sub 2}. The concentration of Mg{sup 2+} uptake in β-Ca{sub 3}(PO{sub 4}){sub 2} is limited till reaching the stoichiometric ratio of (Ca+Mg)/P=1.67 and beyond this stoichiometric value [(Ca+Mg)/P>1.67], Mg{sup 2+} precipitates as Mg(OH){sub 2} and thereafter gets converted to MgO during heat treatment. Any kind of Mg{sup 2+} uptake in the crystal lattice of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2} is discarded from the investigation. - Highlights: • Aqueous co-precipitation of calcium deficient apatites with excess magnesium (Mg{sup 2+}) additions. • Heat treatments beyond 800 °C results in the formation of biphasic apatite mixtures. • Mg{sup 2+} gets accommodated at the β-Ca{sub 3}(PO{sub 4}){sub 2} lattice of biphasic mixtures. • Mg{sup 2+} additions exceeding stoichiometric value (Ca/P>1.67) results in its formation as MgO. • Mg{sup 2+} occupancy at β-Ca{sub 3}(PO{sub 4}){sub 2} lattice delays its allotropic conversion α-Ca{sub 3}(PO{sub 4}){sub 2} till 1350 °C.

  3. Evolution of a mini-scale biphasic dissolution model: Impact of model parameters on partitioning of dissolved API and modelling of in vivo-relevant kinetics.

    PubMed

    Locher, Kathrin; Borghardt, Jens M; Frank, Kerstin J; Kloft, Charlotte; Wagner, Karl G

    2016-08-01

    Biphasic dissolution models are proposed to have good predictive power for the in vivo absorption. The aim of this study was to improve our previously introduced mini-scale dissolution model to mimic in vivo situations more realistically and to increase the robustness of the experimental model. Six dissolved APIs (BCS II) were tested applying the improved mini-scale biphasic dissolution model (miBIdi-pH-II). The influence of experimental model parameters including various excipients, API concentrations, dual paddle and its rotation speed was investigated. The kinetics in the biphasic model was described applying a one- and four-compartment pharmacokinetic (PK) model. The improved biphasic dissolution model was robust related to differing APIs and excipient concentrations. The dual paddle guaranteed homogenous mixing in both phases; the optimal rotation speed was 25 and 75rpm for the aqueous and the octanol phase, respectively. A one-compartment PK model adequately characterised the data of fully dissolved APIs. A four-compartment PK model best quantified dissolution, precipitation, and partitioning also of undissolved amounts due to realistic pH profiles. The improved dissolution model is a powerful tool for investigating the interplay between dissolution, precipitation and partitioning of various poorly soluble APIs (BCS II). In vivo-relevant PK parameters could be estimated applying respective PK models. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Process for separating and recovering an anionic dye from an aqueous solution

    DOEpatents

    Rogers, Robin; Horwitz, E. Philip; Bond, Andrew H.

    1998-01-01

    A solid/liquid phase process for the separation and recovery of an anionic dye from an aqueous solution is disclosed. The solid phase comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the anionic dye molecules are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt. After contact between the aqueous solution and separation particles, the anionic dye is bound to the particles. The bound anionic dye molecules are freed from the separation particles by contacting the anionic dye-bound particles with an aqueous solution that does not contain a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt to form an aqueous anionic dye solution whose anionic dye concentration is preferably higher than that of the initial dye-containing solution.

  5. Process for separating and recovering an anionic dye from an aqueous solution

    DOEpatents

    Rogers, R.; Horwitz, E.P.; Bond, A.H.

    1998-01-13

    A solid/liquid phase process for the separation and recovery of an anionic dye from an aqueous solution is disclosed. The solid phase comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the anionic dye molecules are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt. After contact between the aqueous solution and separation particles, the anionic dye is bound to the particles. The bound anionic dye molecules are freed from the separation particles by contacting the anionic dye-bound particles with an aqueous solution that does not contain a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved lyotropic salt to form an aqueous anionic dye solution whose anionic dye concentration is preferably higher than that of the initial dye-containing solution. 7 figs.

  6. Process boundaries of irreversible scCO2 -assisted phase separation in biphasic whole-cell biocatalysis.

    PubMed

    Brandenbusch, Christoph; Glonke, Sebastian; Collins, Jonathan; Hoffrogge, Raimund; Grunwald, Klaudia; Bühler, Bruno; Schmid, Andreas; Sadowski, Gabriele

    2015-11-01

    The formation of stable emulsions in biphasic biotransformations catalyzed by microbial cells turned out to be a major hurdle for industrial implementation. Recently, a cost-effective and efficient downstream processing approach, using supercritical carbon dioxide (scCO2 ) for both irreversible emulsion destabilization (enabling complete phase separation within minutes of emulsion treatment) and product purification via extraction has been proposed by Brandenbusch et al. (2010). One of the key factors for a further development and scale-up of the approach is the understanding of the mechanism underlying scCO2 -assisted phase separation. A systematic approach was applied within this work to investigate the various factors influencing phase separation during scCO2 treatment (that is pressure, exposure of the cells to CO2 , and changes of cell surface properties). It was shown that cell toxification and cell disrupture are not responsible for emulsion destabilization. Proteins from the aqueous phase partially adsorb to cells present at the aqueous-organic interface, causing hydrophobic cell surface characteristics, and thus contribute to emulsion stabilization. By investigating the change in cell-surface hydrophobicity of these cells during CO2 treatment, it was found that a combination of catastrophic phase inversion and desorption of proteins from the cell surface is responsible for irreversible scCO2 mediated phase separation. These findings are essential for the definition of process windows for scCO2 -assisted phase separation in biphasic whole-cell biocatalysis.

  7. Bi-phase transition diagrams of metallic thin multilayers

    SciTech Connect

    Li, J.C.; Liu, W.; Jiang, Q. . E-mail: jiangq@jlu.edu.cn

    2005-02-01

    Phase transitions of metallic multilayers induced by differences in interface energy are considered thermodynamically, based on a thermodynamic model for interface energy and the Goldschmidt premise for lattice contraction. Bi-phase transition diagrams of Co/Cr, Zr/Nb, Ti/Nb and Ti/Al multilayers are constructed, which are in agreement with experimental results.

  8. TREATMENT OF TYPE 2 DIABETES WITH BIPHASIC INSULIN ANALOGUES

    PubMed Central

    Rizvi, Ali A.

    2016-01-01

    The majority of patients with Type 2 diabetes require insulin therapy for treating hyperglycaemia. There are several regimens available for insulin initiation and maintenance. Insulin analogues have been developed to mimic normal physiology as closely as possible. Biphasic analogues can target both fasting and postprandial hyperglycaemia, with the added advantage of being premixed and thus convenient for the patient. A practical and feasible option is to initiate insulin with one or more biphasic preparations at mealtimes, thus providing both basal and prandial coverage. Individual titration of dose and frequency of daily injections with biphasic insulin preparations has the potential for improving glycaemic control with a high degree of patient acceptance. Drawbacks include a more rigid regimen, a relative lack of flexibility, and a somewhat higher degree of glycaemic variability and hypoglycaemia when compared to multiple daily basal-bolus injections. Awareness of the advantages and limitations of biphasic insulin analogues can assist clinicians in their appropriate use for the treatment of patients with Type 2 diabetes. PMID:27918600

  9. Biphasic dose response in low level light therapy - an update.

    PubMed

    Huang, Ying-Ying; Sharma, Sulbha K; Carroll, James; Hamblin, Michael R

    2011-01-01

    Low-level laser (light) therapy (LLLT) has been known since 1967 but still remains controversial due to incomplete understanding of the basic mechanisms and the selection of inappropriate dosimetric parameters that led to negative studies. The biphasic dose-response or Arndt-Schulz curve in LLLT has been shown both in vitro studies and in animal experiments. This review will provide an update to our previous (Huang et al. 2009) coverage of this topic. In vitro mediators of LLLT such as adenosine triphosphate (ATP) and mitochondrial membrane potential show biphasic patterns, while others such as mitochondrial reactive oxygen species show a triphasic dose-response with two distinct peaks. The Janus nature of reactive oxygen species (ROS) that may act as a beneficial signaling molecule at low concentrations and a harmful cytotoxic agent at high concentrations, may partly explain the observed responses in vivo. Transcranial LLLT for traumatic brain injury (TBI) in mice shows a distinct biphasic pattern with peaks in beneficial neurological effects observed when the number of treatments is varied, and when the energy density of an individual treatment is varied. Further understanding of the extent to which biphasic dose responses apply in LLLT will be necessary to optimize clinical treatments.

  10. A biphasic basal body temperature record during pregnancy.

    PubMed

    Urman, B C; McComb, P F

    1989-01-01

    A case of biphasic temperature record is reported during the course of an ectopic pregnancy. Possible implications of this phenomenon may improve our understanding of the role of ovum transmigration and the endocrinological interaction of pregnancy with hormonal control of ovulation.

  11. Biphasic surface amorphous layer lubrication of articular cartilage.

    PubMed

    Graindorge, Simon; Ferrandez, Wendy; Jin, Zhongmin; Ingham, Eileen; Grant, Colin; Twigg, Peter; Fisher, John

    2005-12-01

    The biphasic nature of articular cartilage has been acknowledged for some time and is known to play an important role in many of the biomechanical functions performed by this unique tissue. From the lubrication point of view however, a simple biphasic model is unable to account for the extremely low friction coefficients that have been recorded experimentally, particularly during start-up. In addition, research over the last decade has indicated the presence of a surface amorphous layer on top of articular cartilage. Here, we present results from a finite element model of articular cartilage that includes a thin, soft, biphasic surface amorphous layer (BSAL). The results of this study show that a thin BSAL, with lower elastic modulus, dramatically altered the load sharing between the solid and liquid phases of articular cartilage, particularly in the near-surface regions of the underlying bulk cartilage and within the surface amorphous layer itself where the fluid load support exceeded 85%. By transferring the load from the solid phase to the fluid phase, the biphasic surface layer improves lubrication and reduces friction, whilst also protecting the underlying cartilage surface by 'shielding' the solid phase from elevated stresses. The increase in lubrication effectiveness is shown to be greatest during short duration loading scenarios, such as shock loads.

  12. Cholesterol and Benign Prostate Disease

    PubMed Central

    Freeman, Michael R.; Solomon, Keith R.

    2014-01-01

    The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association bet ween BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemi, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept. PMID:21862201

  13. Pharmacotherapy for benign prostatic hyperplasia.

    PubMed Central

    Narayan, P; Indudhara, R

    1994-01-01

    Benign prostatic hyperplasia is a benign neoplasm of the prostate seen in men of advancing age. Microscopic evidence of the disorder is seen in about 70% of men by 70 years of age, whereas symptoms requiring some form of surgical intervention occur in 30% of men during their lifetime. Although the exact cause of benign prostatic hyperplasia is not clear, it is well recognized that high levels of intraprostatic androgens are required for the maintenance of prostatic growth. In recent years, extensive surveys of patients undergoing transurethral resection of the prostate reveal an 18% incidence of morbidity that has essentially not changed in the past 30 years. This procedure is also the second highest reimbursed surgical therapy under Medicare. These findings have resulted in an intensive search for alternative therapies for prostatic hyperplasia. An alternative that has now been well defined is the use of alpha-adrenergic blockers to relax the prostatic urethra. This is based on findings that a major component of benign prostatic hyperplasia symptoms is spasm of the prostatic urethra and bladder neck, which is mediated by the alpha-adrenergic nerves. A second approach is to block androgens involved in maintaining prostate growth. Several such drugs are now available for clinical use, and we discuss their side effects and use. We also include the newer recommendations on evaluating benign prostatic hyperplasia that are cost-effective yet comprehensive. Images PMID:7528957

  14. Cholesterol and benign prostate disease.

    PubMed

    Freeman, Michael R; Solomon, Keith R

    2011-01-01

    The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association between BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemia, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept.

  15. Environmentally Benign Stab Detonators

    SciTech Connect

    Gash, A E

    2006-07-07

    The coupling of energetic metallic multilayers (a.k.a. flash metal) with energetic sol-gel synthesis and processing is an entirely new approach to forming energetic devices for several DoD and DOE needs. They are also practical and commercially viable manufacturing techniques. Improved occupational safety and health, performance, reliability, reproducibility, and environmentally acceptable processing can be achieved using these methodologies and materials. The development and fielding of this technology will enhance mission readiness and reduce the costs, environmental risks and the necessity of resolving environmental concerns related to maintaining military readiness while simultaneously enhancing safety and health. Without sacrificing current performance, we will formulate new impact initiated device (IID) compositions to replace materials from the current composition that pose significant environmental, health, and safety problems associated with functions such as synthesis, material receipt, storage, handling, processing into the composition, reaction products from testing, and safe disposal. To do this, we will advance the use of nanocomposite preparation via the use of multilayer flash metal and sol-gel technologies and apply it to new small IIDs. This work will also serve to demonstrate that these technologies and resultant materials are relevant and practical to a variety of energetic needs of DoD and DOE. The goal will be to produce an IID whose composition is acceptable by OSHA, EPA, the Clean Air Act, Clean Water Act, Resource Recovery Act, etc. standards, without sacrificing current performance. The development of environmentally benign stab detonators and igniters will result in the removal of hazardous and toxic components associated with their manufacturing, handling, and use. This will lead to improved worker safety during manufacturing as well as reduced exposure of Service personnel during their storage and or use in operations. The

  16. Development of a biphasic dissolution test for Deferasirox dispersible tablets and its application in establishing an in vitro-in vivo correlation.

    PubMed

    Al Durdunji, Amal; AlKhatib, Hatim S; Al-Ghazawi, Mutasim

    2016-05-01

    In a biphasic dissolution medium, the integration of the in vitro dissolution of a drug in an aqueous phase and its subsequent partitioning into an organic phase is hypothesized to simulate the in vivo drug absorption. Such a methodology is expected to improve the probability of achieving a successful in vitro-in vivo correlation. Dissolution of Dispersible tablets of Deferasirox, a biopharmaceutics classification system type II compound, was studied in a biphasic dissolution medium using a flow-through dissolution apparatus coupled to a paddle apparatus. The experimental parameters associated with dissolution were optimized to discriminate between Deferasirox dispersible tablets of different formulations. The dissolution profiles obtained from this system were subsequently used to construct a level A in vitro-in vivo correlation.

  17. A feasible process for furfural production from the pre-hydrolysis liquor of corncob via biochar catalysts in a new biphasic system.

    PubMed

    Deng, Aojie; Lin, Qixuan; Yan, Yuhuan; Li, Huiling; Ren, Junli; Liu, Chuanfu; Sun, Runcang

    2016-09-01

    A feasible approach was developed to produce furfural from the pre-hydrolysis liquor of corncob via biochar catalysts as the solid acid catalyst in a new biphasic system with dichloromethane (DCM) as the organic phase and the concentrated pre-hydrolysis liquor (CPHL) containing NaCl as the aqueous phase. The biochar catalyst possessing many acidity groups (SO3H, COOH and phenolic OH groups) was prepared by the carbonization and sulfonation process of the corncob hydrolyzed residue. The influence of the catalytic condition on furfural yield and selectivity was comparatively studied. It was found that 81.14% furfural yield and 83.0% furfural selectivity were obtained from CPHL containing 5wt% xylose using this biochar catalyst in the CPHL-NaCl/DCM biphasic system at 170°C for 60min. In addition, with the regeneration process, this catalyst displayed the high performance and excellent recyclability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Multicystic Benign Mesothelioma Complicating Pregnancy.

    PubMed

    Tamhankar, V A

    2015-01-01

    Multicystic benign mesothelioma (MBM) is a rare peritoneal pathology typically affecting women in reproductive age. Though MBM is considered benign, these lesions are prone to recurrence and their growth could be modulated by the presence of oestrogen receptors. Acute presentation of MBM is still very rare in pregnancy and management options are not established. We describe a case of MBM presenting in early pregnancy with acute pain. This was successfully treated with surgical resection. Pregnancy continued uneventfully to term and no evidence of recurrent MBM was found at Caesarean section.

  19. Multicystic Benign Mesothelioma Complicating Pregnancy

    PubMed Central

    Tamhankar, V. A.

    2015-01-01

    Multicystic benign mesothelioma (MBM) is a rare peritoneal pathology typically affecting women in reproductive age. Though MBM is considered benign, these lesions are prone to recurrence and their growth could be modulated by the presence of oestrogen receptors. Acute presentation of MBM is still very rare in pregnancy and management options are not established. We describe a case of MBM presenting in early pregnancy with acute pain. This was successfully treated with surgical resection. Pregnancy continued uneventfully to term and no evidence of recurrent MBM was found at Caesarean section. PMID:26345310

  20. [Benign stenosis of the esophagus].

    PubMed

    Salis, G; Lazaroni, F; Chiocca, J C; Mazure, P A; Sferco, A

    1978-09-01

    In the present study 39 patients with benign esphageal stenosis were studied (average age 59,9 years). The most common etiology was refux esofagitis, and the most common associated pathology was esophageal hiatus hernia. Thirty one patients received medical treatment (diet. antireflux drugs and dilatations.) Twenty four were dilated with the slow continuous method, six with metalic bougies. One patient was not dilated. Seven patients were not treated since the stenosis was due to extrinsec compression. One patient was surgically treated from the onset. Seventy percent of the patients had goods results with esophageal dilatation. We propose that patients with benign esophageal stenosis should be treated by the slow continuous dilatation method.

  1. Radiotherapy of unusual benign disease

    SciTech Connect

    Aristizabel, S.A.; Runyon, T.D.

    1981-10-01

    Four different case reports are presented with a review of the literature in which radiation therapy was used for the treatment of four rare benign diseases: pyogenic granuloma of the middle ear, juvenile xanthogranuloma of the iris, a fourth ventricle choroid plexus papilloma, and an ovarian lymphangioma associated with peritoneal lymphangiomatosis. A trial of radiation therapy was given in each case, because of extenuating circumstances. We hope that the information presented here will contribute to current guidelines used in weighting patient benefits versus potential risks of therapy when ionizing radiation is considered as a mode of therapy for benign disorders.

  2. Benign paroxysmal torticollis of infancy.

    PubMed

    Drigo, P; Carli, G; Laverda, A M

    2000-05-01

    Benign paroxysmal torticollis is an episodic functional disorder of unknown etiology that occurs in the early months of life in healthy individuals. The child's head tilts to one side for a few hours or days, usually without any associated symptoms. The disorder, which disappears within the first few years of life, is often misinterpreted and the patient pointlessly undergoes numerous tests. We present our series of 22 patients observed at the pediatric neurology outpatients clinic in Padova with a view to refreshing the pediatrician's memory on this frequent, benign pathology.

  3. Benign Prostatic Hyperplasia: An Overview

    PubMed Central

    Roehrborn, Claus G

    2005-01-01

    Despite the deceptively simple description of benign prostatic hyperplasia (BPH), the actual relationship between BPH, lower urinary tract symptoms (LUTS), benign prostatic enlargement, and bladder outlet obstruction is complex and requires a solid understanding of the definitional issues involved. The etiology of BPH and LUTS is still poorly understood, but the hormonal hypothesis has many arguments in its favor. There are many medical and minimally invasive treatment options available for affected patients. In the intermediate and long term, minimally invasive treatment options are superior to medical therapy in terms of symptom and flow rate improvement; tissue ablative surgical treatment options are superior to both minimally invasive and medical therapy. PMID:16985902

  4. The biphasic nature of nitric oxide responses in tumor biology.

    PubMed

    Ridnour, Lisa A; Thomas, Douglas D; Donzelli, Sonia; Espey, Michael G; Roberts, David D; Wink, David A; Isenberg, Jeffrey S

    2006-01-01

    The dual or biphasic responses of cancer to nitric oxide (NO) arise from its concentration dependent ability to regulate tumor growth, migration, invasion, survival, angiogenesis, and metastasis. The outcome of these various NO-dependent processes is dictated by several factors including NO flux, the chemical redox environment, and the duration of NO exposure. Further, it was recently discovered that an NO-induced redox flux in vascular endothelial cells hypersensitizes these cells to the antiangiogenic effects of thrombospondin-1. This suggests a novel treatment paradigm for targeting tumor-driven angiogenesis that combines redox modulation with mimetic derivatives of thrombospondin-1. This article discusses the biphasic nature of NO in cancer biology and the implications of NO-driven redox flux for modulation of tumor-stimulated angiogenesis, growth, and metastasis.

  5. Time-engineeringed biphasic drug release by electrospun nanofiber meshes.

    PubMed

    Huang, Li-Ya; Branford-White, Christopher; Shen, Xia-Xia; Yu, Deng-Guang; Zhu, Li-Min

    2012-10-15

    A drug-loaded nanofiber mesh which could achieve time-engineeringed biphasic release was fabricated through sequential electrospinning. The drug to polymer ratio of each single mesh was allocated and designed before the tri-layered meshes were created. The resultant meshes had the following construction: (i) the first drug-loaded mesh (top side), (ii) the second drug-loaded mesh (second side), and (iii) the third drug-loaded mesh (bottom side). The drug release speed and duration were controlled by designing morphological features of the electrospun meshes such as the fiber diameter and mesh thickness. An in vitro release experiment revealed that the tri-layered construction with distinct morphological features of each component mesh can provide biphasic drug release. The time-engineeringed dual release system using the multilayered electrospun nanofiber meshes was proved to be a useful formulation when achieving controlled drug release at different times. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Biophysical shunt theory for neuropsychopathology: biphasal homeostatic dysregulation.

    PubMed

    Naisberg, Y; Weizman, A

    1999-03-01

    We challenge Freud's psychodynamic theory using a systematic modus operandi which has been outlined in detail in a succession of articles. Here, we deal with Freud's first assumption of human psychological primacy in forming goal-directed behavior. According to our theory, biphasal homeostatic dysregulation is the underlying mechanism of clinical phenomenology. Evolutionary neurobiology has provided humans with a precise technical solution for optimal organismic survival. Humans are armed with an accurate negative feedback mechanism that operates within the alternating upper and lower thresholds of biphasal homeostatic maintenance and is coupled with a basal indicator of individual sensation of the degree of the given organismic well-being in any unit of time. This originates the organismic pleasure principle (OPP). The latter is achieved by a straightforward quantal injection of endorphins according to one of eight possible body operational regimens. Thanks to the essential duality of the dynamic interactions, stipulated by the complex harmonics of term-dependent and event-dependent adaptation when one or more of the essential elements for homeostasis goes above or below its predetermined threshold, certain branches of the organismic defense system (ODS) are 'turned on' in the second phase of homeostasis. The individual then adapts behavioral modifications directed toward a long-lasting search for the optimal resources needed for normal survival. This evolutionary biphasal homeostatic design has an intrinsic, methodical expression that confirms changes and correctly informs the individual about them, further imposing behavioral modifications, when necessary. In cases of a homeostatic derangement, the OPP is replaced by an erratic inclusion of pain, tension or depression, all components of the alarm system of the ODS, which may lead to disordered behavioral patterns. The underlying biological mechanism of goal-directed assignments for biphasal homeostatic

  7. Benign Breast Problems and Conditions

    MedlinePlus

    ... fluid. Fibroadenoma: A type of solid, benign breast mass. Hormone: A substance made in the body by cells or organs that controls the function ... breast are used to detect breast cancer. The image that is created is called a ... mass containing normal cells. Obstetrician–Gynecologist (Ob-Gyn): A ...

  8. Benign ear cyst or tumor

    MedlinePlus

    ... Bony tumor of the ear canal Images Ear anatomy References Nicolai P, Castelnuovo P. Benign tumors of the sinonasal tract. In: Flint PW, Haughey BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. Philadelphia, PA: Elsevier Saunders; ...

  9. Benign Breast Problems and Conditions

    MedlinePlus

    ... are benign breast lumps or masses? • What is mastitis? • How is mastitis treated? • What are the signs and symptoms of ... recommended, along with close follow-up. What is mastitis? Mastitis is an infection of the breast tissue. ...

  10. Biphasic dose response in low level light therapy.

    PubMed

    Huang, Ying-Ying; Chen, Aaron C-H; Carroll, James D; Hamblin, Michael R

    2009-09-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing cell death and tissue damage has been known for over forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial in mainstream medicine. The biochemical mechanisms underlying the positive effects are incompletely understood, and the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. A biphasic dose response has been frequently observed where low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. The so-called Arndt-Schulz curve is frequently used to describe this biphasic dose response. This review will cover the molecular and cellular mechanisms in LLLT, and describe some of our recent results in vitro and in vivo that provide scientific explanations for this biphasic dose response.

  11. Biphasic interaction of Triton detergents with the erythrocyte membrane.

    PubMed Central

    Trägner, D; Csordas, A

    1987-01-01

    Octylphenoxy polyoxyethylene ethers (Triton detergents) interact with the erythrocyte membrane in a biphasic manner, i.e. they stabilize erythrocytes against hypo-osmotic haemolysis at low concentrations (0.0001-0.01%, v/v), but become haemolytic at higher concentrations. This biphasic behaviour was demonstrated with Triton X-114, Triton X-100 and Triton X-102. However, a critical chain length is a prerequisite for the haemolytic effect, because Triton X-45, which differs from the other Tritons only by the shorter chain of the polyoxyethylene residue, does not exhibit this biphasic behaviour, but goes on protecting against osmotic rupture up to saturating concentrations. Even a 1% solution of Triton X-45 does not cause haemolysis. This structural specificity of Triton X-45, namely the lack of haemolysis and efficient stabilization against osmolysis even at higher concentrations of the detergent, is exhibited at 0 degree and 37 degrees C as well as at room temperature. Three conclusions are reached: (i) a critical chain length of the octylphenoxy polyoxyethylene ethers is required for the haemolytic effect; (ii) the different structural requirements would suggest that different mechanisms are responsible for the haemolytic and the stabilizing effect of amphiphilic substances; (iii) the results suggest that haemolysis is not caused simply by dissolution of the membrane by the detergent but is a rather more specific process. PMID:3446180

  12. Biphasic Dose Response in Low Level Light Therapy

    PubMed Central

    Huang, Ying-Ying; Chen, Aaron C.-H.; Carroll, James D.; Hamblin, Michael R.

    2009-01-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing cell death and tissue damage has been known for over forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial in mainstream medicine. The biochemical mechanisms underlying the positive effects are incompletely understood, and the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. A biphasic dose response has been frequently observed where low levels of light have a much better effect on stimulating and repairing tissues than higher levels of light. The so-called Arndt-Schulz curve is frequently used to describe this biphasic dose response. This review will cover the molecular and cellular mechanisms in LLLT, and describe some of our recent results in vitro and in vivo that provide scientific explanations for this biphasic dose response. PMID:20011653

  13. REACTION PARAMETER EFFECTS ON METAL-SALT- CATALYZED AQUEOUS BIPHASIC PULPING SYSTEMS. (R826732)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. POLYMER-BASED AQUEOUS BIPHASIC SEPARATION IN THE PAPER PULPING PROCESS. (R826732)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  15. SOME NOVEL LIQUID PARTITIONING SYSTEMS: WATER-IONIC LIQUIDS AND AQUEOUS BIPHASIC SYSTEMS. (R828257)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  16. In vitro biphasic dissolution tests and their suitability for establishing in vitro-in vivo correlations: A historical review.

    PubMed

    Pestieau, Aude; Evrard, Brigitte

    2017-05-01

    For many decades, one of the most critical issues in the pharmaceutical industry has been the poor solubility of some drugs. Indeed, a prerequisite for drug absorption is the presence of dissolved drug at the absorption site and this can be challenging for compounds with low aqueous solubility such as BCS class II (low solubility, high permeability) and IV (low solubility, low permeability) compounds. If the development of oral delivery formulations of these compounds is frequently challenging to formulation scientists in the pharmaceutical industry, the in vitro evaluation of these new formulations is also a great challenge. One alternative approach to overcome the problems encountered with conventional dissolution methods is the use of biphasic dissolution systems. This review provides an overview of the origin and the evolution over time of the biphasic systems and the growing interest among scientists regarding their suitability for establishing in vitro-in vivo correlations. The evolution of these systems and their applications from the 1960s to the present day, such as in system variants and improvements, analysis of complex formulations, discriminatory power, bio-relevance, precipitation and supersaturation visualization, etc. will be discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Low temperature N,N-dimethylformamide-assisted synthesis and characterization of anatase-rutile biphasic nanostructured titania.

    PubMed

    Estruga, M; Domingo, C; Domènech, X; Ayllón, J A

    2009-03-25

    Anatase and rutile biphasic nanostructured titania (TiO(2)) has been synthesized via hydrolysis of titanium tetraisopropoxide in an aqueous solution of hydrobromic acid (HBr) and N,N-dimethylformamide (DMF) at 80 degrees C for 16 h. The presence of DMF, which was partially hydrolyzed during the process, determined the formation of a biphasic material. Powder x-ray diffraction showed the presence of both anatase and rutile titania phases in a ratio of approx. 1:1. Transmission electron microscope analysis showed that rutile was present as radial flower-like nanorods, which were surrounded by anatase spherical nanoparticles of 5 nm diameter. Low temperature nitrogen adsorption-desorption analysis showed the characteristic hysteresis loop of a mesoporous material. Specific surface area reached a value of 120 m(2) g(-1) and the average pore diameter was 50 A. X-ray photoelectron spectroscopic analysis revealed that interstitial nitrogen was incorporated (0.35 at.%) during the annealing process. According to ultraviolet (UV)-visible diffuse reflectance spectroscope characterization, the N-doping caused a bandgap reduction from 3.0 to 2.9 eV. Photocatalytic activity of the material was tested for the degradation of methylene blue, methyl orange and 4-nitrophenol under near-UV and visible light radiation.

  18. Low temperature N,N-dimethylformamide-assisted synthesis and characterization of anatase-rutile biphasic nanostructured titania

    NASA Astrophysics Data System (ADS)

    Estruga, M.; Domingo, C.; Domènech, X.; Ayllón, J. A.

    2009-03-01

    Anatase and rutile biphasic nanostructured titania (TiO2) has been synthesized via hydrolysis of titanium tetraisopropoxide in an aqueous solution of hydrobromic acid (HBr) and N,N-dimethylformamide (DMF) at 80 °C for 16 h. The presence of DMF, which was partially hydrolyzed during the process, determined the formation of a biphasic material. Powder x-ray diffraction showed the presence of both anatase and rutile titania phases in a ratio of approx. 1:1. Transmission electron microscope analysis showed that rutile was present as radial flower-like nanorods, which were surrounded by anatase spherical nanoparticles of 5 nm diameter. Low temperature nitrogen adsorption-desorption analysis showed the characteristic hysteresis loop of a mesoporous material. Specific surface area reached a value of 120 m2 g-1 and the average pore diameter was 50 Å. X-ray photoelectron spectroscopic analysis revealed that interstitial nitrogen was incorporated (0.35 at.%) during the annealing process. According to ultraviolet (UV)-visible diffuse reflectance spectroscope characterization, the N-doping caused a bandgap reduction from 3.0 to 2.9 eV. Photocatalytic activity of the material was tested for the degradation of methylene blue, methyl orange and 4-nitrophenol under near-UV and visible light radiation.

  19. Sodium lauryl sulfate impedes drug release from zinc-crosslinked alginate beads: switching from enteric coating release into biphasic profiles.

    PubMed

    Taha, Mutasem O; Nasser, Wissam; Ardakani, Adel; Alkhatib, Hatim S

    2008-02-28

    The aim of this research is to investigate the effects of sodium lauryl sulfate (SLS) on ionotropically cross-linked alginate beads. Different levels of SLS were mixed with sodium alginate and chlorpheniramine maleate (as loaded model drug). The resulting viscous solutions were dropped onto aqueous solutions of zinc or calcium ions for ionotropic curing. The generated beads were assessed by their drug releasing profiles, infrared and differential scanning colorimetery (DSC) traits. SLS was found to exert profound concentration-dependent impacts on the characteristics of zinc-crosslinked alginate beads such that moderate modifications in the levels of SLS switched drug release from enteric coating-like behavior to a biphasic release modifiable to sustained-release by the addition of minute amounts of xanthan gum. Calcium cross-linking failed to reproduce the same behavior, probably due to the mainly ionic nature of calcium-carboxylate bonds compared to the coordinate character of their zinc-carboxylate counterparts. Apparently, moderate levels of SLS repel water penetration into the beads, and therefore minimize chlorpheniramine release. However, higher SLS levels seem to discourage polymeric cross-linking and therefore allow biphasic drug release.

  20. Preferential occupancy of strontium in the hydroxyapatite lattice in biphasic mixtures formed from non-stoichiometric calcium apatites.

    PubMed

    Nandha Kumar, P; Mishra, Sandeep K; Udhay Kiran, R; Kannan, S

    2015-05-07

    The present study reports the variations in phase content of biphasic mixtures and structural changes induced by different levels of strontium addition in calcium-deficient apatite (Ca/P = 1.60) powders during heat treatment. The synthesis was attempted by an in situ aqueous precipitation technique and X-ray diffraction, Raman spectroscopy and Rietveld refinement of the powder X-ray diffraction data were employed for comprehensive analysis. The results confirm the preferential occupancy of Sr(2+) at two different Ca(2+) sites of the hydroxyapatite [Ca10(PO4)6(OH)2, HAP] lattice, with the Ca(2+) (2) site accommodating more Sr(2+) than the Ca(2+) (1) site. Increasing Sr(2+) addition in calcium-deficient apatite has led to a decline in the phase content of β-tricalcium phosphate [β-Ca3(PO4)2, β-TCP] in biphasic mixtures of HAP and β-TCP. Sr(2+) addition exceeding the critical limit of a (Ca + Sr)/P > 1.75 molar ratio has resulted in the formation of CaO as an additional phase, and this justifies the lack of enough PO4(3-) ions to promote any kind of calcium phosphate precipitation. Sr(2+) accommodation in the lattice sites of HAP has induced an increase in the lattice parameters and has also led to the significant distortion of the PO4 tetrahedron and OH groups, confirmed by Raman and FT-IR spectroscopic techniques.

  1. [Benign pleural pathology of asbestos].

    PubMed

    Chailleux, E; Rembeaux, A; de Lajartre, A Y; Delumeau, J

    1988-01-01

    The most frequent benign lesions of the pleura created by asbestos are fibro-hyaline plaques, i.e. thick areas of collagen located on the parietal pleura and gradually becoming calcified. Less common is benign pleural effusion the cause of which is not always easy to determine. To these must be added an extensive pleural fibrosis with functional repercussions that are not negligible, and round pseudotumoral atelectasias. These pleural asbestos-induced lesions are often observed after a low intensity exposure, but they appear as a rule after more than 20 years of latency. While they betray a previous exposure to asbestos, they also raise the problem of possible asbestos-induced lung cancer and mesothelioma.

  2. Benign Pediatric Salivary Gland Lesions.

    PubMed

    Carlson, Eric R; Ord, Robert A

    2016-02-01

    Salivary gland lesions are rare in pediatric patients. In addition, the types of salivary gland tumors are different in their distribution in specific sites in the major and minor salivary glands in children compared with adults. This article reviews benign neoplastic and nonneoplastic salivary gland disorders in pediatric patients to help clinicians to develop an orderly differential diagnosis that will lead to expedient treatment of pediatric patients with salivary gland lesions. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Patient reported outcomes in benign multiple sclerosis.

    PubMed

    Hviid, Line E; Healy, Brian C; Rintell, David J; Chitnis, Tanuja; Weiner, Howard L; Glanz, Bonnie I

    2011-07-01

    Benign MS patients have a mild course of disease and show no or minimal accumulation of disability over time. Little is known about the patient reported outcomes (PROs) in benign MS. The objective of the study was to compare PROs in benign MS patients and patients with similar disease duration or disability status, and to investigate how the definition of benign MS affected this outcome. Two groups of Benign MS patients (disease duration ≥15 years, Expanded Disability Status Scale [EDSS] score ≤1.5 [Benign-1.5], or ≤3.0 [Benign-3]) were compared with four other MS groups: disease duration ≥15 years, EDSS score >3.0 (Late-MS); disease duration <15 years, and EDSS score ≤1.5 (Low-EDSS-1.5), or ≤3.0 (Low-EDSS-3); disease duration ≤5 years (Early-MS). PROs included measures of QOL, fatigue, depression, and social support. Cognitive function was also assessed. Both benign groups had better PROs than Late MS patients on all measures (p < 0.05). QOL, depression, and fatigue were significantly different between Benign-1.5 and Early-MS groups (p < 0.01). Benign-1.5 had higher mental health QOL than Low EDSS-1.5, but was otherwise similar. Benign-3 patients had worse depression than Early-MS (p < 0.01), and worse cognition compared with Low-EDSS-3 (p = 0.033). Benign-1.5 had higher QOL and lower fatigue (p < 0.005) than Benign-2-3, and showed a marginally significant difference in cognitive functioning (p = 0.055). Patients with benign MS had better PROs than other groups of MS patients, suggesting that both disease duration and disability influence PROs. The study also showed a difference in PROs based on the way benign MS was defined.

  4. Biphasic NF-kappaB activation in the excitotoxic hippocampus.

    PubMed

    Caba, Ebru; Bahr, Ben A

    2004-09-01

    Excitotoxic stimulation of NMDA receptors results in the activation of a variety of cellular responses. The inducible transcription factor NF-kappaB is known to be involved in excitotoxic responses by neurons. Here, we show that NF-kappaB activation occurs in a biphasic manner in hippocampal slices following a 20-min N-methyl- d-aspartate (NMDA) exposure. The biphasic activation profile consists of an early, rapid phase at 0.5-1 h post-insult, and a delayed phase evident 10-24 h post-insult. Endogenous inhibitors of NF-kappaB, IkappaBs, were examined for their involvement in the biphasic activation. IkappaBbeta exhibited marked degradation in response to the excitotoxity, while changes in the levels of IkappaBalpha and p105 isoforms were not detected. The initial decline in IkappaBbeta occurred in as little as 30 min post-NMDA exposure, coinciding with early NF-kappaB activity. A second, more gradual phase of IkappaBbeta degradation was also evident, possibly giving rise to the delayed activation of the transcription factor. While both phases of NF-kappaB activation were disrupted by the NMDA receptor antagonist AP5, they were distinct with regard to the composition of activated complexes and their responsiveness to altered culture conditions. The two phases of NF-kappaB activity also were associated with distinct gene regulation events. Up-regulation of bcl-2 message occurred early after the excitotoxic insult and remained up-regulated for an extended period. In contrast, bax message initially remained unchanged after the insult, but then exhibited an increase 24 h later, corresponding with the second phase of the NF-kappaB response. These results indicate that distinct phases of NF-kappaB activation are generated in the excitotoxic hippocampus, and that the phases may be involved in opposing cellular responses.

  5. Aerosol Particle Interfacial Thermodynamics and Phase Partitioning Measurements Using Biphasic Microfluidics

    NASA Astrophysics Data System (ADS)

    Dutcher, Cari; Metcalf, Andrew

    2015-03-01

    Secondary organic aerosol particles are nearly ubiquitous in the atmosphere and yet there remain large uncertainties in their formation processes and ambient properties. These particles are complex microenvironments, which can contain multiple interfaces due to internal aqueous-organic phase partitioning and to the external liquid-vapor surface. Interfacial properties affect the ambient aerosol morphology, or internal structure of the particle, which in turn can affect the way a particle interacts with an environment of condensable clusters and organic vapors. To improve our ability to accurately predict ambient aerosol morphology, we must improve our knowledge of aerosol interfaces and their interactions with the ambient environment. Unfortunately, many techniques employed to measure interfacial properties do so in bulk solutions or in the presence of a ternary (e.g. solid) phase. In this talk, a novel method using biphasic microscale flows will be introduced for generating, trapping, and perturbing complex interfaces at atmospherically relevant conditions. These microfluidic experiments utilize high-speed imaging to monitor interfacial phenomena at the microscale and are performed with phase contrast and fluorescence microscopy on a temperature-controlled inverted microscope stage. From these experiments, interfacial thermodynamic properties such as surface or interfacial tension, rheological properties such as interfacial moduli, and kinetic properties such as mass transfer coefficients can be measured or inferred.

  6. In vitro Biphasic Effect of Honey Bee Venom on Basophils from Screened Healthy Blood Donors

    PubMed Central

    Zanoni, Giovanna; Ortolani, Riccardo; Vella, Antonio

    2011-01-01

    Apis mellifera L. bee venom is the most studied hymenoptera allergen, but many aspects of its action on human basophils remain unclear. Allergologists seek evidence of the effectiveness of bee venom immunotherapy as this approach is the chosen treatment for systemic allergic reactions. The effect of bee venom on human basophils in vitro has not been studied in detail for many reasons, including the paucity of basophils in peripheral blood, inter-individual basophil response variability, and the reliability and predictability of basophil activation tests. We conducted a brief preliminary survey of the effect of Apis bee venom on healthy asymptomatic (non-allergic) subjects. A dose of an aqueous commercial extract of Apis bee venom as high as 10 µg/mL activated resting basophils (CD63=+80-90%, CD203c=+30%), while it inhibited the expression of CD63 (-50%) following basophil stimulation by the soluble agonists formyl-Met-Leu-Phe or anti-IgE. The activation of resting basophils appeared to be dose-related. Only when basophils were activated with an IgE-mediated agonist, did bee venom extract exhibit a possible priming mechanism at the lowest doses used only via CD63, while it was ineffective via CD203c. Autocrine interleukin-3 may play a role in the observed biphasic behavior. PMID:21217927

  7. Biphasic effect of Syzygium aromaticum flower bud on reproductive physiology of male mice.

    PubMed

    Mishra, R K; Singh, S K

    2016-11-01

    The flower buds of Syzygium aromaticum (clove) have been used for the treatment of male sexual disorders in indigenous medicines of Indian subcontinent. Therefore to evaluate the efficacy of Syzygium aromaticum on the male reproductive health, chronic oral exposure of aqueous extract of flower buds of Syzygium in three doses (15 mg, 30 mg and 60 mg kg(-1) BW) were studied for a single spermatogenic cycle (35 days) in Parkes (P) strain mice. Lower dose (15 mg) of Syzygium aromaticum flower buds increased serum testosterone level and testicular hydroxysteroid dehydrogenase (HSD) activities and improved sperm motility, sperm morphology, secretory activity of epididymis and seminal vesicle, and number of litters per female. On the other hand, higher doses (30 and 60 mg) of the treatment adversely affected above parameters. Further, higher doses of the extract also had adverse effects on daily sperm production, 1C cell population and on histology of testis. In conclusion, Syzygium aromaticum flower buds extract exhibits biphasic effect on reproductive physiology of male mice. Lower dose of Syzygium aromaticum flower bud extract is androgenic in nature and may have a viable future as an indigenous sexual rejuvenator, while higher doses adversely affected functional physiology of reproductive organs. © 2016 Blackwell Verlag GmbH.

  8. Influence of saline solution on hydration behavior of β-dicalcium silicate in comparison with biphasic calcium phosphate/hydroxyapatite bio-ceramics.

    PubMed

    Radwan, M M; Abd El-Hamid, H K; Mohamed, A F

    2015-12-01

    The influence of using saline solution as mixing and curing liquid on some characteristics of β-dicalcium silicate (β-C2S) and biphasic compound tri-calcium phosphate/hydroxyapatite (TCP/HAp) bio-ceramics was investigated. β-C2S (27-30 nm) was prepared by solid state reaction at 1450°C, while biphasic compound TCP/HAp (7-15 nm) was synthesized from an aqueous solution of Ca(NO3)2·4H2O and (NH4)2HPO4·12H2O by chemical precipitation method. Setting times, compressive strength, pH values, X-ray diffraction analysis, infrared spectroscopy, scanning electron microscopy (SEM) were investigated. The evaluation of cytotoxicity of both calcium silicate and biphasic compounds to human gingival fibroblasts was carried out. The use of saline solution as mixing and immersing liquid shortened the setting time for the two bio-cements. TCP/HAp did not show any mechanical strength but β-C2S showed good strength values. Both synthesized compounds showed a moderate cytotoxicity and both materials were effective in a no significant way.

  9. Overview of the effect of salts on biphasic ionic liquid/water solvent extraction systems: anion exchange, mutual solubility, and thermomorphic properties.

    PubMed

    Dupont, David; Depuydt, Daphne; Binnemans, Koen

    2015-06-04

    Hydrophobic (water-immiscible) ionic liquids (ILs) are frequently used as organic phase in solvent extraction studies. These biphasic IL/water extraction systems often also contain metal salts or mineral acids, which can significantly affect the IL trough (un)wanted anion exchange and changes in the solubility of IL in the aqueous phase. In the case of thermomorphic systems, variations in the cloud point temperature are also observed. All these effects have important repercussions on the choice of IL, suitable for a certain extraction system. In this paper, a complete overview of the implications of metal salts on biphasic IL/water systems is given. Using the Hofmeister series as a starting point, a range of intuitive prediction models are introduced, supported by experimental evidence for several hydrophobic ILs, relevant to solvent extraction. Particular emphasis is placed on the IL betainium bis(trifluoromethylsulfonyl)imide [Hbet][Tf2N]. The aim of this work is to provide a comprehensive interpretation of the observed effects of metal salts, so that it can be used to predict the effect on any given biphasic IL/water system instead of relying on case-by-case reports. These prediction tools for the impact of metal salts can be useful to optimize IL synthesis procedures, extraction systems and thermomorphic properties. Some new insights are also provided for the rational design of ILs with UCST or LCST behavior based on the choice of IL anion.

  10. Biphasic enantioselective olefin epoxidation using Tropos dibenzoazepinium catalysts.

    PubMed

    Vachon, Jérôme; Pérollier, Céline; Monchaud, David; Marsol, Claire; Ditrich, Klaus; Lacour, Jérôme

    2005-07-22

    Several novel chiral iminium TRISPHAT [tris(tetrachlorobenzenediolato)phosphate(V)] salts combining a diphenylazepinium core, chiral exocyclic appendages, and lipophilic counterions have been prepared and tested in biphasic enantioselective olefin epoxidation conditions. Interestingly, the iminium salts derived from commercially available (S)- or (R)-1,2,2-trimethylpropylamine can display efficiency similar to those made from L-acetonamine. Variable-temperature NMR spectroscopy (VT-NMR) and circular dichroism (CD) experiments were performed in search of a correlation between good enantioselectivity in the products and high diastereomeric control of the biphenyl axial chirality of the catalysts.

  11. Organic aqueous tunable solvents (OATS): a vehicle for coupling reactions and separations.

    PubMed

    Pollet, Pamela; Hart, Ryan J; Eckert, Charles A; Liotta, Charles L

    2010-09-21

    In laboratory-based chemical synthesis, the choice of the solvent and the means of product purification are rarely determined by cost or environmental impact considerations. When a reaction is scaled up for industrial applications, however, these choices are critical: the separation of product from the solvent, starting materials, and byproduct usually constitutes 60-80% of the overall cost of a process. In response, researchers have developed solvents and solvent-handling methods to optimize both the reaction and the subsequent separation steps on the manufacturing scale. These include "switchable" solvents, which are designed so that their physical properties can be changed abruptly, as well as "tunable" solvents, wherein the solvent's properties change continuously through the application of an external stimulus. In this Account, we describe the organic aqueous tunable solvent (OATS) system, examining two instructive and successful areas of application of OATS as well as its clear potential for further refinement. OATS systems address the limitations of biphasic processes by optimizing reactions and separations simultaneously. The reaction is performed homogeneously in a miscible aqueous-organic solvent mixture, such as water-tetrahydrofuran (THF). The efficient product separation is conducted heterogeneously by the simple addition of modest pressures of CO(2) (50-60 bar) to the system. Under these conditions, the water-THF phase splits into two relatively immiscible phases: the organic THF phase contains the hydrophobic product, and the aqueous phase contains the hydrophilic catalyst. We take advantage of the unique properties of OATS to develop environmentally benign and cost-competitive processes relevant in industrial applications. Specifically, we describe the use of OATS for optimizing the reaction, separation, design, and recycling of (i) Rh-catalyzed hydroformylation of olefins such as 1-octene and (ii) enzyme-catalyzed hydrolysis of 2-phenylacetate. We

  12. Cell–material interactions on biphasic polyurethane matrix

    PubMed Central

    Dicesare, Patrick; Fox, Wade M.; Hill, Michael J.; Krishnan, G. Rajesh; Yang, Shuying; Sarkar, Debanjan

    2013-01-01

    Cell–matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell–matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration. PMID:23255285

  13. Biphasic behavior of energy in a stepped chain

    NASA Astrophysics Data System (ADS)

    Ping-Jian, Wang; Ai-Xiang, He; Zhong-Hai, Lin; Guang-Fen, Wei; Yan-Li, Liu

    2016-06-01

    The impact energy decay in a step-up chain containing two sections is numerically studied. There is a marked biphasic behavior of energy decay in the first section. Two sections close to the interface are in compression state. The degree of compression of the first section first decreases and becomes weakest at “crossing” time of biphasic behavior of energy, then increases. The further calculations provide the dependence of the character time on mass ratio (m 1/m 2), where m 1 and m 2 are the particle mass in the first and second section respectively. The bigger the α (α = [(Ωm 1 - m 2)/(Ωm 1 + m 2)]2 with Ω = 1.345), the bigger the energy ratio is. The multipulse structure restricts the transport of energy. Project supported by the National Natural Science Foundation of China (Grant Nos. 61174007 and 61307041) and the Natural Science Foundation of Shandong Province, China (Grant No. ZR2013AL014).

  14. Biphasic patterns of diversification and the emergence of modules

    PubMed Central

    Mittenthal, Jay; Caetano-Anollés, Derek; Caetano-Anollés, Gustavo

    2012-01-01

    The intricate molecular and cellular structure of organisms converts energy to work, which builds and maintains structure. Evolving structure implements modules, in which parts are tightly linked. Each module performs characteristic functions. In this work we propose that a module can emerge through two phases of diversification of parts. Early in the first phase of this biphasic pattern, the parts have weak linkage—they interact weakly and associate variously. The parts diversify and compete. Under selection for performance, interactions among the parts increasingly constrain their structure and associations. As many variants are eliminated, parts self-organize into modules with tight linkage. Linkage may increase in response to exogenous stresses as well as endogenous processes. In the second phase of diversification, variants of the module and its functions evolve and become new parts for a new cycle of generation of higher-level modules. This linkage hypothesis can interpret biphasic patterns in the diversification of protein domain structure, RNA and protein shapes, and networks in metabolism, codes, and embryos, and can explain hierarchical levels of structural organization that are widespread in biology. PMID:22891076

  15. A New Biphasic Dicalcium Silicate Bone Cement Implant

    PubMed Central

    Murciano, Angel; Maté-Sánchez de Val, José E.

    2017-01-01

    This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C2S) cement. Biphasic α´L + β-C2Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C2S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement’s surface after soaking in SBF. The cell attachment test showed that α´L + β-C2Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration. PMID:28773119

  16. A New Biphasic Dicalcium Silicate Bone Cement Implant.

    PubMed

    Zuleta, Fausto; Murciano, Angel; Gehrke, Sergio A; Maté-Sánchez de Val, José E; Calvo-Guirado, José L; De Aza, Piedad N

    2017-07-06

    This study aimed to investigate the processing parameters and biocompatibility of a novel biphasic dicalcium silicate (C₂S) cement. Biphasic α´L + β-C₂Sss was synthesized by solid-state processing, and was used as a raw material to prepare the cement. In vitro bioactivity and biocompatibility studies were assessed by soaking the cement samples in simulated body fluid (SBF) and human adipose stem cell cultures. Two critical-sized defects of 6 mm Ø were created in 15 NZ tibias. A porous cement made of the high temperature forms of C₂S, with a low phosphorous substitution level, was produced. An apatite-like layer covered the cement's surface after soaking in SBF. The cell attachment test showed that α´L + β-C₂Sss supported cells sticking and spreading after 24 h of culture. The cement paste (55.86 ± 0.23) obtained higher bone-to-implant contact (BIC) percentage values (better quality, closer contact) in the histomorphometric analysis, and defect closure was significant compared to the control group (plastic). The residual material volume of the porous cement was 35.42 ± 2.08% of the initial value. The highest BIC and bone formation percentages were obtained on day 60. These results suggest that the cement paste is advantageous for initial bone regeneration.

  17. Biphasic cardiovascular and respiratory effects induced by β-citronellol.

    PubMed

    Ribeiro-Filho, Helder Veras; de Souza Silva, Camila Meirelles; de Siqueira, Rodrigo JoséBezerra; Lahlou, Saad; dos Santos, Armênio Aguiar; Magalhães, Pedro Jorge Caldas

    2016-03-15

    β-Citronellol is a monoterpene found in the essential oil of various plants with antihypertensive properties. In fact, β-citronellol possesses hypotensive actions due to its vasodilator abilities. Here we aimed to show that β-citronellol recruits airway sensory neural circuitry to evoke cardiorespiratory effects. In anesthetized rats, intravenous injection of β-citronellol caused biphasic hypotension, bradycardia and apnea. Bilateral vagotomy, perivagal capsaicin treatment or injection into the left ventricle abolished first rapid phase (named P1) but not delayed phase P2 of the β-citronellol effects. P1 persisted after pretreatment with capsazepine, ondansetron, HC-030031 or suramin. Suramin abolished P2 of apnea. In awake rats, β-citronellol induced biphasic hypotension and bradycardia being P1 abolished by methylatropine. In vitro, β-citronellol inhibited spontaneous or electrically-evoked contractions of rat isolated right or left atrium, respectively, and fully relaxed sustained contractions of phenylephrine in mesenteric artery rings. In conclusion, chemosensitive pulmonary vagal afferent fibers appear to mediate the cardiovascular and respiratory effects of β-citronellol. The transduction mechanism in P1 seems not to involve the activation of transient receptor potential vanilloid subtype 1 (TRPV1), transient receptor potential ankyrin subtype 1 (TRPA1), purinergic (P2X) or 5-HT3 receptors located on airways sensory nerves. P2 of hypotension and bradycardia seems resulting from a cardioinhibitory and vasodilatory effect of β-citronellol and the apnea from a purinergic signaling.

  18. Biphasic Affinity Chromatographic Approach for Deep Tyrosine Phosphoproteome Analysis.

    PubMed

    Deng, Zhenzhen; Dong, Mingming; Wang, Yan; Dong, Jing; Li, Shawn S-C; Zou, Hanfa; Ye, Mingliang

    2017-02-21

    Tyrosine phosphorylation (pTyr) is important for normal physiology and implicated in many human diseases, particularly cancer. Identification of pTyr sites is critical to dissecting signaling pathways and understanding disease pathologies. However, compared with serine/threonine phosphorylation (pSer/pThr), the analysis of pTyr at the proteome level is more challenging due to its low abundance. Here, we developed a biphasic affinity chromatographic approach where Src SH2 superbinder was coupled with NeutrAvidin affinity chromatography, for tyrosine phosphoproteome analysis. With the use of competitive elution agent biotin-pYEEI, this strategy can distinguish high-affinity phosphotyrosyl peptides from low-affinity ones, while the excess competitive agent is readily removed by using NeutrAvidin agarose resin in an integrated tip system. The excellent performance of this system was demonstrated by analyzing tyrosine phosphoproteome of Jurkat cells from which 3,480 unique pTyr sites were identified. The biphasic affinity chromatography method for deep Tyr phosphoproteome analysis is rapid, sensitive, robust, and cost-effective. It is widely applicable to the global analysis of the tyrosine phosphoproteome associated with tyrosine kinase signal transduction.

  19. Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements.

    PubMed

    Gallinetti, Sara; Canal, Cristina; Ginebra, Maria-Pau; Ferreira, J

    2014-04-01

    Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca(2+) release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media.

  20. Cell-material interactions on biphasic polyurethane matrix.

    PubMed

    Dicesare, Patrick; Fox, Wade M; Hill, Michael J; Krishnan, G Rajesh; Yang, Shuying; Sarkar, Debanjan

    2013-08-01

    Cell-matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell-matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration. Copyright © 2012 Wiley Periodicals, Inc.

  1. Process for preparing organoclays for aqueous and polar-organic systems

    DOEpatents

    Chaiko, David J.

    2001-01-01

    A process for preparing organoclays as thixotropic agents to control the rheology of water-based paints and other aqueous and polar-organic systems. The process relates to treating low-grade clay ores to achieve highly purified organoclays and/or to incorporate surface modifying agents onto the clay by adsorption and/or to produce highly dispersed organoclays without excessive grinding or high shear dispersion. The process involves the treatment of impure, or run-of-mine, clay using an aqueous biphasic extraction system to produce a highly dispersed clay, free of mineral impurities and with modified surface properties brought about by adsorption of the water-soluble polymers used in generating the aqueous biphasic extraction system. This invention purifies the clay to greater than 95%.

  2. Rare benign tumours of the nipple.

    PubMed

    Spyropoulou, G A; Pavlidis, L; Trakatelli, M; Athanasiou, E; Pazarli, E; Sotiriadis, D; Demiri, E

    2015-01-01

    Benign lesions of the breast in total are much more frequent than malignant ones. However, there are no epidemiologic data on the prevalence of benign or malignant tumours of the nipple, and the bibliography on benign nipple tumours in general is limited. To present some rare cases of benign nipple tumours and review the literature. Four cases of rare benign nipple tumours: neurofibromas, wart, leiomyoma and milium are presented. The literature search on benign nipple tumours was performed using MEDLINE, Pubmed, and Cochrane databases with limits: English language, human species and available abstract. The keyword used was 'benign nipple tumours'. The initial search retrieved 337 articles. The papers were reviewed and the articles that referred to benign lesions that appeared at the nipple specifically were identified. Different entities that were described included: neurofibroma, leiomyoma, milium, florid papillomatosis, syringomatous adenoma, nevoid hyperkeratosis, fibroma, pseudolymphoma and haemangioma. Differential diagnosis of benign tumours of the nipple can be demanding for the physicians. Many of the symptoms and signs like pruritus, serosanguinous discharge, lichenification, erosion and nodular enlargement are produced by either malignant or benign nipple lesions. Radiology can be unclear in the diagnosis of nipple abnormalities. Histological examination of the lesion can be the only definite answer in these cases. © 2014 European Academy of Dermatology and Venereology.

  3. An augmented Lagrangian finite element formulation for 3D contact of biphasic tissues.

    PubMed

    Guo, Hongqiang; Spilker, Robert L

    2014-01-01

    Biphasic contact analysis is essential to obtain a complete understanding of soft tissue biomechanics, and the importance of physiological structure on the joint biomechanics has long been recognised; however, up to date, there are no successful developments of biphasic finite element contact analysis for three-dimensional (3D) geometries of physiological joints. The aim of this study was to develop a finite element formulation for biphasic contact of 3D physiological joints. The augmented Lagrangian method was used to enforce the continuity of contact traction and fluid pressure across the contact interface. The biphasic contact method was implemented in the commercial software COMSOL Multiphysics 4.2(®) (COMSOL, Inc., Burlington, MA). The accuracy of the implementation was verified using 3D biphasic contact problems, including indentation with a flat-ended indenter and contact of glenohumeral cartilage layers. The ability of the method to model multibody biphasic contact of physiological joints was proved by a 3D knee model. The 3D biphasic finite element contact method developed in this study can be used to study the biphasic behaviours of the physiological joints.

  4. Biphasic reactions in patients with anaphylaxis treated with corticosteroids.

    PubMed

    Ko, Byuk Sung; Kim, Won Young; Ryoo, Seung Mok; Ahn, Shin; Sohn, Chang Hwan; Seo, Dong-Woo; Lee, Yoon-Seon; Lim, Kyoung Soo; Kim, Tae-Bum

    2015-10-01

    Although the incidence of anaphylaxis is rapidly increasing, the clinical characteristics and associated factors of a biphasic reaction are unclear. To determine the incidence and clinical characteristics of biphasic reactions in patients with anaphylaxis treated with corticosteroids. A total of 655 patients with anaphylaxis visiting the emergency department of a tertiary teaching hospital from January 2007 through December 2014 were analyzed. Patient characteristics, triggers, symptoms and signs, in-hospital management, and disposition were recorded. A biphasic reaction was defined as the development of anaphylaxis after complete resolution of the initial reaction without further exposure to the offending agent within 7 days. Univariate and multivariate analyses on the predictors of the biphasic reaction were performed. Of the 415 patients with anaphylaxis treated with corticosteroids, 9 patients (2.2%) developed a biphasic reaction. The mean age was 48.4 years, and 221 patients (54.4%) were women. The median time from complete resolution of initial clinical symptoms to occurrence of the biphasic reaction was 15 hours (range 1-45). History of drug anaphylaxis (odds ratio 14.3, 95% confidence interval 2.4-85.8) was a contributing factor to the development of the biphasic reaction. The incidence of biphasic reactions was 2.2% in patients treated with corticosteroids and those with a history of drug anaphylaxis were at greater risk. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  5. [Benign myoclonic epilepsy in infancy].

    PubMed

    Mukhin, K Iu; Petrukhin, A S; Pylaeva, O A; Iukhalina, N S; Glukhova, L Iu; Abramova, M F

    1999-01-01

    Benign myoclonic epilepsy in infancy (NMEI) is one of rare epileptic syndromes. 5 patients (all female sex) aged 4-16 years were observed. NMEI debuted at the age from 7 months till 2.5 years (mean age 1.3 years). Pathology of pregnancy and labor, disorders in both psychomotor development and genetic predisposition were not found. In all the cases the disease began with typical transitory repeated myoclonic paroxysms of different intensity and frequency, without loss of consciousness and with primary involvement of the muscles of the neck and the upper extremities. Most patients had muscular hypotension, mild coordinatory disorders, delayed psycho-speech development, mental retardation, EEG signs of generalized epileptic activity. Valproates, suxilep, clonazepam and lamotrigin (lamiktal) were used for treatment. The most pronounced effect was achieved using either monotherapy with valproates (depakin) or a combination depakin + lamiktal. A stable clinical-encephalographic remission was achieved in all the patients, but during puberty in 2 patients (15 and 16 years old) rare generalized convulsive fits debuted. High frequency of intellectual-mnestic disorders were found even after a complete remission. So benign definition concerns only a course of the fits, but not NMEI prognosis.

  6. Benign External Hydrocephalus in Infants

    PubMed Central

    Adele Marino, Maria; Morabito, Rosa; Vinci, Sergio; Germanò, Antonino; Briguglio, Marilena; Alafaci, Concetta; Mormina, Enricomaria; Longo, Marcello; Granata, Francesca

    2014-01-01

    Summary External hydrocephalus (EH) is a benign clinical entity in which macrocephaly is associated with an increase in volume of the subarachnoid space, especially overlying both frontal lobes, and a normal or only slight increase in volume of the lateral ventricles. Several pathogenic hypotheses have been proposed but the most accredited theory seems to be delayed maturation of the arachnoid villi. There is a consensus that this is a benign entity, correlated to a familial predisposition and, in some cases, inheritance. CT and MRI are very important to make a diagnosis but also to establish the prognosis in patients who encounter the rare complications such as subdural haematomas. In conclusion, CT and MRI can provide a highly accurate diagnosis in these patients, allowing a preliminary assessment of the prognosis, particularly regarding the enlarged subarachnoid space limits and the “cortical vein" sign which can predict a further complication. These results are obtained with the same examination performed in a standard CT or MRI study of the brain and no injection of contrast medium is needed. PMID:24750715

  7. Benign paroxysmal vertigo of childhood.

    PubMed

    Drigo, P; Carli, G; Laverda, A M

    2001-03-01

    Benign paroxysmal vertigo of childhood (BPV) is a paroxysmal, non-epileptic, recurrent event characterized by subjective or objective vertigo that occurs in neurologically intact children. We recorded the history and the clinical aspects of 19 cases presenting with neurological problems to the outpatient clinic at the Pediatrics Department of Padova University between 1987 and 1998 and re-examined in 1999. Details were collected on the characteristics of their vertigo: age at onset, mode of onset, trigger factors, duration, frequency and recurrence of episodes, duration of symptoms in time and age at disappearance. An attempt was also made to establish any family history of migraine and kinetosis and the most important data were compared, when possible, with those reported in the literature. Differential diagnosis and pathogenetic hypothesis were also reported. It is worth emphasizing that it is important for pediatricians to be aware of these benign events to ensure a correct diagnostic approach, avoiding the child and family any pointless anxiety or costly and sometimes invasive diagnostic procedures.

  8. Evaluation of liquid biphasic Granada medium and instant liquid biphasic Granada medium for group B streptococcus detection.

    PubMed

    Martinho, Filipa; Prieto, Emília; Pinto, Dulce; Castro, Rita Maria; Morais, Ana Maria; Salgado, Luísa; Exposto, Filomena da Luz

    2008-02-01

    Group B streptococci (GBS) are transmitted from the mother to the newborn. Prevention of neonatal infection is achieved by intrapartum prophylaxis given to mothers colonized with GBS at 35 to 37 weeks of pregnancy. Liquid biphasic Granada medium (LB) and instant liquid biphasic Granada medium (ILB) were evaluated for GBS detection. Vaginal swabs obtained from 300 women were inoculated onto LB or ILB, or onto Todd-Hewitt broth and analyzed with the ATB system (comparison method). Prevalence of GBS was 20% (61/300). LB and Todd-Hewitt with ATB detected GBS in 20% of women, and ILB in 19% of women. No growth was observed at four hours in any of the media studied. At 10 h and 14 h, identification of GBS was possible in 43/300 (14%) and 53/300 (18%) of ILB cultures, respectively, and in 32/300 (11%) and 46/300 (15%) of LB cultures. All the media used are suitable for GBS detection. The majority of GBS were identified in ILB and LB cultures at 10 h and 14 h.

  9. Process for recovering chaotropic anions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, R.; Horwitz, E.P.; Bond, A.H.

    1999-03-30

    A solid/liquid process for the separation and recovery of chaotropic anions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the chaotropic anions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt (lyotrope). A solid/liquid phase admixture of separation particles containing bound chaotropic anions in such an aqueous solution is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture. 19 figs.

  10. Process for recovering chaotropic anions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, Robin; Horwitz, E. Philip; Bond, Andrew H.

    1999-01-01

    A solid/liquid process for the separation and recovery of chaotropic anions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the chaotropic anions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt (lyotrope). A solid/liquid phase admixture of separation particles containing bound chaotropic anions in such an aqueous solution is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture.

  11. Predictors of biphasic reactions in the emergency department for patients with anaphylaxis.

    PubMed

    Lee, Sangil; Bellolio, M Fernanda; Hess, Erik P; Campbell, Ronna L

    2014-01-01

    A biphasic reaction is the recurrence of anaphylaxis symptoms within 72 hours of the initial anaphylactic event, without re-exposure to the trigger. Biphasic reactions are uncommon and unpredictable, and risk factors for biphasic reactions are poorly understood. To identify predictors of biphasic anaphylactic reactions in patients with anaphylaxis in the emergency department (ED). Patients of all ages who presented to the ED and met diagnostic criteria for anaphylaxis from April 2008 to January 2013 at an academic medical center with 73,000 annual patient visits were consecutively included. We collected data on patient characteristics, suspected triggers, signs and symptoms, ED management, and disposition. Univariate analyses were performed to estimate the association between potential predictor variables and biphasic reactions. We report associations as odds ratios (OR) and corresponding 95% CIs. Among 541 patients with anaphylaxis, median age was 34.6 years (interquartile range, 18-52 years), and 320 (59%) were female patients. Twenty-one patients (4%) had biphasic reactions. Two pediatric patients, ages of 5 years old and 16 years old, developed a biphasic reaction. The median time between the resolution of initial symptoms and onset of the biphasic reaction was 7 hours (range, 1-72 hours). Biphasic reactions were associated with a history of prior anaphylaxis (OR 2.6 [95% CI, 1.1-6.4]; P = .029), unknown precipitant (OR 2.6 [95% CI, 1.1-6.2]; P = .03), symptoms of diarrhea (OR 4.5 [95% CI, 1.4-14.0]; P = .024), and wheezing (OR 2.6 [95% CI, 1.4-8.9]; P = .029). Patients with a history of prior anaphylaxis, an unknown precipitant, or who present with symptoms of diarrhea or wheezing may be at increased risk for a biphasic reaction. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  12. Injectable biphasic calcium phosphate bioceramic: The HYDROS concept.

    PubMed

    Baroth, Serge; Bourges, Xavier; Goyenvalle, Eric; Aguado, Eric; Daculsi, Guy

    2009-01-01

    A new biphasic calcium phosphate ceramic material has been developed in our laboratory. It is composed of 60% of hydroxyapatite and 40% of beta-tricalcium phosphate, based on three granulometries (submicron, round microporous 80-200 mum and macro microporous 0.5-1 mm particles) and hydrated with water leading the formation of a putty filler for bone repair. Biocompatibility and osteogenicity were tested by filling femoral epiphyses critical size bone defect and lumbar muscles in rabbit. After 3, 6 and 12 weeks of implantation, explants were treated for histology. Results revealed the biocompatibility of the material and intensive resorption of the submicron particle fraction followed by important bone ingrowth whereas osteoconduction was provided by the larger particles.

  13. High-side Digitally Current Controlled Biphasic Bipolar Microstimulator

    PubMed Central

    Hanson, Timothy L.; Ómarsson, Björn; O'Doherty, Joseph E.; Peikon, Ian D.; Lebedev, Mikhail; Nicolelis, Miguel AL.

    2012-01-01

    Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. With the realized device and standard recording hardware - without active artifact rejection - we are able to observe stimulus artifacts of less than 2 ms in duration. PMID:22328184

  14. Surface modification of biphasic calcium phosphate bioceramic powders

    NASA Astrophysics Data System (ADS)

    Yang, W. Z.; Zhou, D. L.; Yin, G. F.; Li, G. D.

    2008-11-01

    Biphasic calcium phosphate (BCP)/poly L-lactide (PLLA) biocomposite is proven to be a promising bone graft material or scaffold for bone tissue engineering. To improve the interfacial compatibility of BCP bioceramic with biopolymer-PLLA, BCP powders were surface-modified in different condition to graft polymer groups onto the surface of the BCP powders. L-lactide and L-lactic acid (LA) oligomer were used to modify the BCP surface with stannous octanoate (Sn(Oct) 2) and stannous chloride (SnCl 2) as catalyst, respectively. Results show that the surface modification effect is obvious and the amount of grafted organic group is above 6.5 wt.%. Sn(Oct) 2 and SnCl 2 are the optimal catalysts for the surface grafting reaction of L-lactide and L-LA oligomer, respectively. The surface grafting slightly increase the particle size of BCP powders and reduce the tendency for their agglomeration.

  15. High-side digitally current controlled biphasic bipolar microstimulator.

    PubMed

    Hanson, Timothy L; Ómarsson, Björn; O'Doherty, Joseph E; Peikon, Ian D; Lebedev, Mikhail A; Nicolelis, Miguel A L

    2012-05-01

    Electrical stimulation of nervous tissue has been extensively used as both a tool in experimental neuroscience research and as a method for restoring of neural functions in patients suffering from sensory and motor disabilities. In the central nervous system, intracortical microstimulation (ICMS) has been shown to be an effective method for inducing or biasing perception, including visual and tactile sensation. ICMS also holds promise for enabling brain-machine-brain interfaces (BMBIs) by directly writing information into the brain. Here we detail the design of a high-side, digitally current-controlled biphasic, bipolar microstimulator, and describe the validation of the device in vivo. As many applications of this technique, including BMBIs, require recording as well as stimulation, we pay careful attention to isolation of the stimulus channels and parasitic current injection. With the realized device and standard recording hardware-without active artifact rejection-we are able to observe stimulus artifacts of less than 2 ms in duration.

  16. Biphasic Role of Calcium in Mouse Sperm Capacitation Signaling Pathways

    PubMed Central

    Alvau, Antonio; Escoffier, Jessica; Krapf, Dario; Sánchez-Cárdenas, Claudia; Salicioni, Ana M.; Darszon, Alberto; Visconti, Pablo E.

    2016-01-01

    Mammalian sperm acquire fertilizing ability in the female tract in a process known as capacitation. At the molecular level, capacitation is associated with up-regulation of a cAMP-dependent pathway, changes in intracellular pH, intracellular Ca2+ and an increase in tyrosine phosphorylation. How these signaling systems interact during capacitation is not well understood. Results presented in this study indicate that Ca2+ ions have a biphasic role in the regulation of cAMP-dependent signaling. Media without added Ca2+ salts (nominal zero Ca2+) still contain micromolar concentrations of this ion. Sperm incubated in this medium did not undergo PKA activation or the increase in tyrosine phosphorylation suggesting that these phosphorylation pathways require Ca2+. However, chelation of the extracellular Ca2+ traces by EGTA induced both cAMP-dependent phosphorylation and the increase in tyrosine phosphorylation. The EGTA effect in nominal zero Ca2+ media was mimicked by two calmodulin antagonists, W7 and calmidazolium, and by the calcineurin inhibitor cyclosporine A. These results suggest that Ca2+ ions regulate sperm cAMP and tyrosine phosphorylation pathways in a biphasic manner and that some of its effects are mediated by calmodulin. Interestingly, contrary to wild type mouse sperm, sperm from CatSper1 KO mice underwent PKA activation and an increase in tyrosine phosphorylation upon incubation in nominal zero Ca2+ media. Therefore, sperm lacking Catsper Ca2+ channels behave as wild-type sperm incubated in the presence of EGTA. This latter result suggests that Catsper transports the Ca2+ involved in the regulation of cAMP-dependent and tyrosine phosphorylation pathways required for sperm capacitation. PMID:25597298

  17. Biphasic effects of losartan potassium on immobility in mice.

    PubMed

    Vijayapandi, Pandi; Nagappa, Anantha Naik

    2005-08-01

    The effects of losartan potassium, an angiotensin AT(1) receptor blocker on immobility in forced swim test have been studied. Effect of losartan potassium, nortriptyline HCl, fluoxetine HCl and reserpine per se and in combination on forced swimming-induced immobility in mice have also been studied. In mice, losartan potassium elicits biphasic responses i.e. positive responses at lower doses (0.1, 1.0 and 5 mg/kg, i.p.) in the forced swim test, a test of potential antidepressant activity and vice versa at higher dose (20 and 100 mg/kg, i.p.). In chronic studies, enhancement in immobility was observed for losartan potassium (3 and 30 mg/kg, p.o., 21 days). In acute combination studies, losartan potassium (1 and 5 mg/kg) significantly reversed the reserpine-induced immobility, but vice versa at 100 mg/kg. Losartan potassium (0.1 and 5 mg/kg) potentiate antidepressant activity of nortriptyline (30 mg/kg, i.p.) in mice, but vice versa at 100 mg/kg. Likewise, Losartan potassium (100 mg/kg), significantly reversed antidepressant activity of fluoxetine HCl, but at 0.1 and 5 mg/kg, failed to modify fluoxetine HCl induced immobility. The obtained biphasic effect of losartan potassium on immobility in mice might be due to inhibitory effect on AT(1) receptor at lower dose and pronounced effect on AT(2) receptor at higher dose (large concentrations of losartan potassium can displace Angiotensin II (Ang II) from its AT(1) receptor to AT(2) receptor.

  18. Copper: a biphasic regulator of caprine sperm forward progression.

    PubMed

    Roy, Debarun; Dey, Souvik; Majumder, Gopal Chandra; Bhattacharyya, Debdas

    2014-02-01

    Copper is essential for spermatogenesis and its presence has been demonstrated in male and female reproductive fluids in several mammalian species. However, little is known about the physiological significance of this trace element in the regulation of forward progression of mammalian sperm cells which is essential for sperm fertility potential in vivo. The purpose of this investigation was to determine the physiological role of the bivalent copper ion (Cu(2+)) on mammalian sperm forward motility using a chemically-defined medium and caprine cauda epididymal sperm model. Sperm forward motility was significantly enhanced by Cu(2+) in a dose-dependent manner; maximal activation (approx 20%) was noted at the 5 µM level of the metal. Above 10 µM Cu(2+) sperm motility decreased, showing that Cu(2+) exerts a biphasic regulation on sperm motility. These findings have been confirmed using a spectrophotometric motility assay, an objective method of motility analysis. At lower concentrations (up to 5 µM), copper enhanced sperm membrane lipid peroxidation as well as the level of intra-sperm cyclic adenosine mono phosphate (c-AMP), but at a higher level it caused marked inhibition of both of the biochemical parameters. The observed correlation of Cu(2+)-dependent biphasic modulation of sperm membrane lipid peroxidation and intrasperm c-AMP with sperm forward motility is consistent with the view that Cu(2+) regulation of sperm motility is mediated by membrane lipid peroxidation, which in turn modulates the level of intra-sperm c-AMP, a well-known activator of sperm motility.

  19. [Phytotherapy of benign prostatic hyperplasia].

    PubMed

    Bracher, F

    1997-01-01

    Phytopharmaceutical agents have been used for a long time in the treatment of symptomatic benign prostatic hyperplasia (BPH). However, until recently, it has been questioned whether phytotherapy is superior to a placebo treatment. In this article, the most widely used phytopharmaceutical agents, such as saw palmetto berry extracts, Radix urticae extracts, pumpkin seeds, pollen extracts and different phytosterols, are described. In addition, both in vitro and in vivo studies are discussed in an attempt to explain a possible mechanism of action. There are several new clinical studies which demonstrate a significant benefit compared with placebo treatment. Based on these results, the use of phytopharmaceutical agents for the treatment of mild to moderate symptomatic BPH seems to be well justified. So far, no significant inhibition of further prostate growth has been demonstrated. For this, a careful follow-up of the patients is necessary so as not to miss a deterioration and perhaps the need for an operation.

  20. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects.

  1. Benign Lymphangioendothelioma - A Case Report

    PubMed Central

    Kamoji, Sushruth Guruputra; Dastikop, Shilpa Vinay

    2016-01-01

    Benign lymphangioendothelioma is an uncommon locally infiltrative lymphatic tumour, presenting as a slow-growing, asymptomatic, reddish-violaceous macule or plaque. Histopathologically, it is characterized by thin-walled endothelial-lined spaces that are interspersed between strands of collagen. It must be recognized and differentiated from angiosarcoma, early Kaposi’s sarcoma, in view of major differences in treatment and prognosis. A 24-year-old female presented with a raised lesion over the left leg since 2 years which was associated with minimal itching. Biopsy of the lesion showed thin walled vascular channels lined by single layer of bland endothelial cells at the dermo-epidermal junction, few vessels in the dermis. PMID:26894162

  2. Concussion or benign paroxysmal torticollis?

    PubMed

    Reynolds, Ellen

    2012-01-01

    This case report describes a patient who presented to the trauma service on 3 occasions over the course of 2 years, each time with symptoms typical of concussion (e.g., crying, change in mentation, and vomiting). On more in-depth evaluation, it was discovered that the child had torticollis, pallor, and brief dizziness or vertigo with each episode. Benign paroxysmal torticollis is a periodic, paroxysmal syndrome that may be mistaken for the more common concussion. In addition to illustrating a uniquely pediatric neurological syndrome, this case demonstrates the importance of taking a careful history and considering a full range of differential diagnoses when evaluating every patient, even those with seemingly routine injuries.

  3. Comparison of stromal CD10 expression in benign, borderline, and malignant phyllodes tumors among Egyptian female patients.

    PubMed

    Ibrahim, Wael S

    2011-01-01

    Phyllodes tumors are group of biphasic fibroepithelial tumors of the breast of varying malignant potential, ranging from benign tumors to fully malignant sarcomas. According to the Egyptian National Cancer Institute, female malignant cases showed appreciable increase in the recent time period for breast cancer with the malignant phyllodes tumors representing 0.41% of cases in the year 2003-2004. This is an immunohistochemical study to compare CD10 expression in benign, borderline, and malignant phyllodes tumors, in order to highlight its diagnostic and prognostic values. This study conducted 34 Egyptian female cases of phyllodes tumors of different grades to be studied histologically and immunohistochemically using antibodies against CD10. The Chi-square test was used to determine differences in CD10 expression between benign, borderline, and malignant tumors. One-way ANOVA test was used to determine whether the difference was significant. Significance was established at P<0.05. In the 24 cases of benign phyllodes tumors, only four cases (16.7%) showed positive CD10 reactivity. Three cases (60%) out of five borderline phyllodes tumors showed positive CD10 reactivity, while four (80%) out of five cases of malignant phyllodes tumors showed positive CD10 staining. From these highly significant results, we believe that there is a strong correlation between CD10 expression and tumor grade, which could be an important observation that may have both diagnostic and prognostic implications as well as promising potential target for development of novel therapies.

  4. Benign intracranial hypertension: diagnosis and conservative management.

    PubMed

    Theisler, C W

    1986-03-01

    The clinical features of benign intracranial hypertension are described. Pathological components are discussed and are contrasted against the current theoretical model of pain production in benign intracranial hypertension. Diagnosis and associated conditions are discussed from a review of the literature, and conservative management is outlined.

  5. Benign lesions of the external auditory canal.

    PubMed

    Tran, L P; Grundfast, K M; Selesnick, S H

    1996-10-01

    Benign mass lesions of the external auditory canal, such as exostoses and osteomas, are common findings on physical examination but most often do not require treatment. The differential diagnosis of lesions in the external auditory canal, however, should not be limited to those benign processes discussed here, but should also include infectious, dermatologic, congenital, and malignant processes.

  6. Malignant Transformation of Pulmonary Benign Metastasizing Leiomyoma

    PubMed Central

    Song, Kyung Sub; Keum, Dong Yoon; Hwang, Il Seon

    2017-01-01

    Pulmonary benign metastasizing leiomyoma (PBML) is defined as metastasis of a leiomyoma to lung tissue. It was first reported in 1937. P BML is known as a benign disease, but can undergo malignant transformation. Only 1 case of the malignant transformation of PBML to leiomyosarcoma has been reported previously. In this report, we present a case of malignant transformation of PBML. PMID:28180107

  7. External cardioversion of atrial fibrillation: comparison of biphasic vs monophasic waveform shocks.

    PubMed

    Ricard, P; Lévy, S; Boccara, G; Lakhal, E; Bardy, G

    2001-04-01

    It is well established in transthoracic ventricular defibrillation that biphasic truncated waveform shocks are associated with superior defibrillation efficacy when compared with damped sine wave monophasic waveform shocks. The aim of this study was to explore whether biphasic waveform shocks were superior to monophasic waveform shocks for external cardioversion of atrial fibrillation (AF). Fifty-seven patients in whom cardioversion of AF was indicated were randomized in this prospective study, to transthoracic cardioversion with either monophasic damped sine waveform shocks or biphasic impedance compensating waveform shocks. In the group randomized to monophasic waveform shocks (27 patients), a first shock of 150 J was delivered, followed (if necessary) by a 360 J shock. In the biphasic waveform group (30 patients), the first shock had an energy of 150 J and (if necessary) a second 150 J was delivered. All shocks were delivered in the anterolateral chest pad position. Sinus rhythm was restored in 16 patients (51%) with the first monophasic shock and in 27 patients (86%) with the first biphasic shock. The difference was statistically significant (P=0.02). After the second shock, sinus rhythm was obtained in a total of 24 patients (88%) with monophasic shocks and in 28 patients (93%) with biphasic shocks. No complication was observed in either group and cardiac enzymes (CK, CKmb, troponin I, myoglobin) did not show any significant changes. This study suggests that at the same energy level of 150 J, biphasic impedance compensating waveform shocks are superior to monophasic damped sine waveform shocks cardioversion of atrial fibrillation.

  8. Biphasic versus monophasic shock for external cardioversion of atrial flutter: a prospective, randomized trial.

    PubMed

    Mortensen, Kai; Risius, Tim; Schwemer, Tjark F; Aydin, Muhammet Ali; Köster, Ralf; Klemm, Hanno U; Lutomsky, Boris; Meinertz, Thomas; Ventura, Rodolfo; Willems, Stephan

    2008-01-01

    External cardioversion is effective to terminate persistent atrial flutter. Biphasic shocks have been shown to be superior to monophasic shocks for ventricular defibrillation and atrial fibrillation cardioversion. The purpose of this trial was to compare the efficacy of rectilinear biphasic versus standard damped sine wave monophasic shocks in symptomatic patients with typical atrial flutter. 135 consecutive patients were screened, 95 (70 males, mean age 62 +/- 13 years) were included. Patients were randomly assigned to a monophasic or biphasic cardioversion protocol. Forty-seven patients randomized to the monophasic protocol received sequential shocks of 100, 150, 200, 300 and 360 J. Forty-eight patients with the biphasic protocol received 50, 75, 100, 150 or 200 J. First-shock efficacy with 50-Joule, biphasic shocks (23/48 patients, 48%) was significantly greater than with the 100-Joule, monophasic waveform (13/47 patients, 28%, p = 0.04). The cumulative second-shock efficacy with the 50- and 75-Joule, biphasic waveform (39/48 patients, 81%) was significantly greater than with the 100- and 150-Joule, monophasic waveform (25/47 patients, 53%, p < 0.05). The cumulative efficacy for the higher energy levels showed naturally no significant difference between the two groups. The amount of the mean delivered energy was significantly lower in the biphasic group (76 +/- 39 J) compared to the monophasic one (177 +/- 78 J, p < 0.05). For transthoracic cardioversion of typical atrial flutter, biphasic shocks have greater efficacy and the mean delivered current is lower than for monophasic shocks. Therefore, biphasic cardioversion with lower starting energies should be recommended. (c) 2008 S. Karger AG, Basel.

  9. Electron transport in zinc-blende wurtzite biphasic gallium nitride nanowires and GaNFETs

    SciTech Connect

    Jacobs, Benjamin W.; Ayres, Virginia M.; Stallcup, Richard E.; Hartman, Alan; Tupta, Mary Ann; Baczewski, Andrew David; Crimp, Martin A.; Halpern, Joshua B.; He, Maoqi; Shaw, Harry C.

    2007-10-19

    Two-point and four-point probe electrical measurements of a biphasic gallium nitride nanowire and current–voltage characteristics of a gallium nitride nanowire based field effect transistor are reported. The biphasic gallium nitride nanowires have a crystalline homostructure consisting of wurtzite and zinc-blende phases that grow simultaneously in the longitudinal direction. There is a sharp transition of one to a few atomic layers between each phase. Here, all measurements showed high current densities. Evidence of single-phase current transport in the biphasic nanowire structure is discussed.

  10. Electron transport in zinc-blende wurtzite biphasic gallium nitride nanowires and GaNFETs

    DOE PAGES

    Jacobs, Benjamin W.; Ayres, Virginia M.; Stallcup, Richard E.; ...

    2007-10-19

    Two-point and four-point probe electrical measurements of a biphasic gallium nitride nanowire and current–voltage characteristics of a gallium nitride nanowire based field effect transistor are reported. The biphasic gallium nitride nanowires have a crystalline homostructure consisting of wurtzite and zinc-blende phases that grow simultaneously in the longitudinal direction. There is a sharp transition of one to a few atomic layers between each phase. Here, all measurements showed high current densities. Evidence of single-phase current transport in the biphasic nanowire structure is discussed.

  11. Benign Hereditary Chorea: An Update

    PubMed Central

    Peall, Kathryn J.; Kurian, Manju A.

    2015-01-01

    Benign hereditary chorea (BHC) is a childhood-onset, hyperkinetic movement disorder normally with little progression of motor symptoms into adult life. The disorder is caused by mutations to the NKX2.1 (TITF1) gene and also forms part of the “brain–lung–thyroid syndrome”, in which additional developmental abnormalities of lung and thyroid tissue are observed. In this review, we summarize the main clinical findings in “classical” BHC syndrome and discuss more recently reported atypical features, including non-choreiform movement phenotypes. We highlight additional non-motor characteristics such as cognitive impairment and psychiatric symptoms, while discussing the evidence for BHC as a developmental disorder involving impaired neural migration and other multisystem developmental abnormalities. Finally, we will discuss the efficacy of available therapies in both affected pediatric and adult cohorts. Delineation of the BHC disease spectrum will no doubt expand our understanding of this disorder, facilitating better targeting of genetic testing and establish a framework for future clinical trials. PMID:26196025

  12. Management of Benign Biliary Strictures

    SciTech Connect

    Laasch, Hans-Ulrich; Martin, Derrick F.

    2002-12-15

    Benign biliary strictures are most commonly a consequence of injury at laparoscopic cholecystectomy or fibrosis after biliary-enteric anastomosis. These strictures are notoriously difficult to treat and traditionally are managed by resection and fashioning of acholedocho- or hepato-jejunostomy. Promising results are being achieved with newer minimally invasive techniques using endoscopic or percutaneous dilatation and/or stenting and these are likely to play an increasing role in the management. Even low-grade biliary obstruction carries the risks of stone formation, ascending cholangitis and hepatic cirrhosis and it is important to identify and treat this group of patients. There is currently no consensus on which patient should have what type of procedure, and the full range of techniques may not be available in all hospitals. Careful assessment of the risks and likely benefits have to be made on an individual basis. This article reviews the current literature and discusses the options available. The techniques of endoscopic and percutaneous dilatation and stenting are described with evaluation of the likely success and complication rates and compared to the gold standard of biliary-enteric anastomosis.

  13. Biphasic vasodilator action of troglitazone on the renal microcirculation.

    PubMed

    Arima, Shuji; Kohagura, Kentaro; Takeuchi, Kazuhisa; Taniyama, Yoshihiro; Sugawara, Akira; Ikeda, Yukio; Abe, Michiaki; Omata, Ken; Ito, Sadayoshi

    2002-02-01

    Recent studies have demonstrated that thiazolidinediones, novel antidiabetic compounds that improve the insulin sensitivity, lower BP and decrease urinary protein excretion. However, neither the target vasculature nor the underlying mechanism for their actions is well understood. In this study, the action of troglitazone (Tro), a thiazolidinedione compound, on the glomerular afferent (Af-Arts) and efferent (Ef-Arts) arterioles, crucial vascular segments to the control of glomerular hemodynamics, were directly examined. Rabbit Af-Arts or Ef-Arts were microdissected from the superficial cortex and perfused at constant pressure. Increasing doses of Tro (10(-8) to 10(-5) M) were added to both the bath and lumen of preconstricted arterioles. In Af-Arts, Tro caused dose-dependent and biphasic dilation. Tro at 10(-5) M increased the diameter by 28 +/- 6% (n = 8, P < 0.01) until 20 min, with the diameter remaining at this level for 60 min, and then Tro began to dilate Af-Arts again. At 120 min, Tro at 10(-5) M further increased the diameter by 23 +/- 4% (n = 6). Disrupting the endothelium had no effect on either dilation (n = 7 or n = 5). Pretreatment with SKF 96365 (50 microM), which inhibits both voltage- and receptor-operated calcium channels, abolished the early-phase dilation without affecting the late-phase dilation; 20 or 120 min after adding Tro at 10(-5) M, the diameter increased by 4 +/- 2% (n = 7) or 28 +/- 3% (n = 6), respectively. In contrast to Af-Arts, Tro caused monophasic dilation in Ef-Arts; Tro at 10(-5) M did not cause significant dilation until 80 min, and at 120 min the diameter increased by 37 +/- 4% (n = 5). These results suggest that in the Af-Art Tro has biphasic endothelium-independent vasodilator action, which is partly mediated by an inhibition of calcium influx. This vasodilator action may play a role in the BP-lowering effect of Tro. In addition, by dilating the postglomerular Ef-Art, Tro may decrease the glomerular capillary pressure and

  14. Progressive and biphasic cardiac responses during extreme mountain ultramarathon.

    PubMed

    Maufrais, Claire; Millet, Grégoire P; Schuster, Iris; Rupp, Thomas; Nottin, Stéphane

    2016-05-15

    Investigations on the cardiac function consequences of mountain ultramarathon (MUM) >100 h are lacking. The present study assessed the progressive cardiac responses during the world's most challenging MUM (Tor des Géants; Italy; 330 km; 24,000 m of cumulative elevation gain). Resting echocardiographic evaluation of morphology, function, and mechanics of left and right ventricle (LV and RV) including speckle tracking echocardiography was conducted in 15 male participants (46 ± 13 yr) before (pre), during (mid; 148 km), and after (post) the race. Runners completed the race in 126 ± 15 h. From pre to post, the increase in stroke volume (SV) (103 ± 19 vs. 110 ± 23 vs. 116 ± 21 ml; P < 0.001 at pre, mid, and post) was concomitant to the increase in LV early filling (peak E; 72.9 ± 15.7 vs. 74.6 ± 13.1 vs. 82.1 ± 11.5 cm/s; P < 0.05). Left and right atrial end-diastolic areas, RV end-diastolic area, and LV end-diastolic volume were 12-19% higher at post compared with pre (P < 0.05). Resting heart rate and LV systolic strain rates demonstrated a biphasic adaptation with an increase from pre to mid (55 ± 8 vs. 72 ± 11 beats/min, P < 0.001) and a return to baseline values from mid to post (59 ± 8 beats/min). Significant correlations were found between pre-to-post percent changes in peak E and LV end-diastolic volume (r = 0.63, P < 0.05) or RV (r = 0.82, P < 0.001) or atrial end-diastolic areas (r = 0.83, P < 0.001). An extreme MUM induced a biphasic pattern of heart rate in parallel with specific cardiac responses characterized by a progressive increase in diastolic filling, biventricular volumes, and SV. The underlying mechanisms and their clinical implications remain challenging for the future.

  15. Biphasic influence of dexamethasone exposure on embryonic vertebrate skeleton development

    SciTech Connect

    Cheng, Xin; Chen, Jian-long; Ma, Zheng-lai; Zhang, Zhao-long; Lv, Shun; Mai, Dong-mei; Liu, Jia-jia; Chuai, Manli; Lee, Kenneth Ka Ho; Wan, Chao; Yang, Xuesong

    2014-11-15

    increased in mesenchymal cell mass treated by low concentration of Dex. Mmp-13 expression was obviously up-regulated by Dex in both mesenchymal cells and primary chondrocyte cultures. And Col10a1 expression was also increased by Dex exposure in chondrocyte. In summary, we have revealed that different concentrations of Dex exposure during early gestation could exert a biphasic effect on vertebrate skeletal development. - Highlights: • Chick embryos occurred shortening of the long bone following Dex exposure. • Dex suppressed chondrocytes proliferation and promoted apoptosis. • Dex exposure decreased ALP production and up-regulated Runx-2 and Mmp-13. • Dex exhibited biphasic effects on chondrogenic proliferation and nodule formation. • The hypertrophy and ossification were accelerated by Dex both in vivo and in vitro.

  16. Benign breast lesions that mimic malignancy.

    PubMed

    Torous, Vanda F; Schnitt, Stuart J; Collins, Laura C

    2017-02-01

    Many benign and reactive lesions of the breast show morphological overlap with malignant lesions. These benign mimics of malignancy often present diagnostic challenges to even the most experienced pathologists. This review focuses on several benign lesions of the breast that mimic malignant entities. For each of these lesions, we describe the key morphological and immunohistochemical features, potential diagnostic pitfalls, and our approach to arriving at the correct diagnosis. Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.

  17. Biphasic metaplastic sarcomatoid carcinoma of the breast: report of a case.

    PubMed

    Haruki, Tomohiro; Maeta, Hiroyuki; Sawazumi, Yuko; Miyasaka, Shigeto; Morimoto, Keisuke; Ishikawa, Noriyoshi; Nakamoto, Shu; Taniguchi, Iwao

    2009-01-01

    A 69-year-old woman was admitted to our hospital with the complaint of a right breast mass. As a result of thorough examinations, she was diagnosed with breast cancer and underwent breast-conserving surgery. The pathological findings of the resected specimen showed that the tumor consisted of intermingled carcinomatous and sarcomatous components with a transition zone. On immunohistochemical study, the sarcomatous cells in this transition zone showed partial positive staining for CD10, the myoepithelial marker, suggesting that the myoepithelial cells had transformed into sarcoma, and then this biphasic tumor was formed. Finally, she was diagnosed with biphasic metaplastic sarcomatoid carcinoma of the breast. Biphasic metaplastic sarcomatoid carcinoma of the breast is a relatively rare but aggressive disease. The pathological diagnosis is often controversial, requiring detailed immunohistochemical analysis. We report our experience with a case of biphasic metaplastic sarcomatoid carcinoma of the breast.

  18. Transthoracic cardioversion of atrial fibrillation: comparison of rectilinear biphasic versus damped sine wave monophasic shocks.

    PubMed

    Mittal, S; Ayati, S; Stein, K M; Schwartzman, D; Cavlovich, D; Tchou, P J; Markowitz, S M; Slotwiner, D J; Scheiner, M A; Lerman, B B

    2000-03-21

    Clinical studies have shown that biphasic shocks are more effective than monophasic shocks for ventricular defibrillation. The purpose of this study was to compare the efficacy of a rectilinear biphasic waveform with a standard damped sine wave monophasic waveform for the transthoracic cardioversion of atrial fibrillation. In this prospective, randomized, multicenter trial, patients undergoing transthoracic cardioversion of atrial fibrillation were randomized to receive either damped sine wave monophasic or rectilinear biphasic shocks. Patients randomized to the monophasic protocol (n=77) received sequential shocks of 100, 200, 300, and 360 J. Patients randomized to the biphasic protocol (n=88) received sequential shocks of 70, 120, 150, and 170 J. First-shock efficacy with the 70-J biphasic waveform (60 of 88 patients, 68%) was significantly greater than that with the 100-J monophasic waveform (16 of 77 patients, 21%, P<0.0001), and it was achieved with 50% less delivered current (11+/-1 versus 22+/-4 A, P<0.0001). Similarly, the cumulative efficacy with the biphasic waveform (83 of 88 patients, 94%) was significantly greater than that with the monophasic waveform (61 of 77 patients, 79%; P=0.005). The following 3 variables were independently associated with successful cardioversion: use of a biphasic waveform (relative risk, 4.2; 95% confidence intervals, 1.3 to 13.9; P=0.02), transthoracic impedance (relative risk, 0.64 per 10-Omega increase in impedance; 95% confidence intervals, 0.46 to 0.90; P=0.005), and duration of atrial fibrillation (relative risk, 0.97 per 30 days of atrial fibrillation; 95% confidence intervals, 0.96 to 0.99; P=0.02). For transthoracic cardioversion of atrial fibrillation, rectilinear biphasic shocks have greater efficacy (and require less energy) than damped sine wave monophasic shocks.

  19. Biphasic transthoracic defibrillation causes fewer ECG ST-segment changes after shock.

    PubMed

    Reddy, R K; Gleva, M J; Gliner, B E; Dolack, G L; Kudenchuk, P J; Poole, J E; Bardy, G H

    1997-08-01

    Electrocardiographic abnormalities are common after transthoracic defibrillation. ECG ST-segment changes are especially problematic after defibrillation and may indicate ischemic or shock-induced cardiac dysfunction after resuscitation. Biphasic defibrillation waveforms, compared with monophasic waveforms, diminish shock-induced cardiac dysfunction in laboratory preparations. This effect has not been validated in human subjects. We therefore evaluated in a prospective, blinded fashion the effect of biphasic and monophasic transthoracic defibrillation on the ECG ST segment in 30 consecutive patients during surgery for the implantation of a cardioverter-defibrillator. In each patient two low-energy truncated biphasic transthoracic defibrillation shocks (115 and 130 J) were compared with a standard clinical 200 J monophasic damped-sine wave shock. The biphasic shocks and the damped-sine wave shock have been demonstrated to have equal defibrillation efficacy of 97%. Fifteen-second ECG signals recorded across transthoracic defibrillation electrodes were digitized before ventricular fibrillation induction and immediately after each defibrillation attempt. The ST segments 80 msec after the J point were analyzed in a blinded fashion by two reviewers. The ST-segment deflection, QRS-interval duration, QT interval, and heart rate after each therapy were compared with baseline values. ECG ST-segment elevation was significantly greater with the 200-J damped-sine waveform than with either biphasic waveform. The ECG ST-segment levels were -.55 +/- .36 at baseline, -.76 +/- .36 mm after internal shock, -.02-.36 mm after 115-J biphasic shock, .21 +/- .38 mm after 130-J biphasic shock, and 2.09 +/- .37 mm after 200-J damped-sine wave shock (P<.0001). QRS-interval duration, QT interval, and heart rate did not change significantly with any waveform. Transthoracic defibrillation with biphasic waveforms results in less postshock ECG evidence of myocardial dysfunction (injury or ischemia

  20. Oscillatory three-phase flow reactor for studies of bi-phasic catalytic reactions.

    PubMed

    Abolhasani, Milad; Bruno, Nicholas C; Jensen, Klavs F

    2015-05-28

    A multi-phase flow strategy, based on oscillatory motion of a bi-phasic slug within a fluorinated ethylene propylene (FEP) tubular reactor, under inert atmosphere, is designed and developed to address mixing and mass transfer limitations associated with continuous slug flow chemistry platforms for studies of bi-phasic catalytic reactions. The technique is exemplified with C-C and C-N Pd catalyzed coupling reactions.

  1. Biphasic modulation of cell growth by recombinant human galectin-1.

    PubMed

    Adams, L; Scott, G K; Weinberg, C S

    1996-06-13

    Human soluble galactose-binding lectin (galectin-1) has been expressed as an Escherichia coli fusion protein, following the amplification by polymerase chain reaction of cDNA prepared from a human osteosarcoma cell line. The fusion protein is a functional beta-galactoside-binding lectin, as is the recombinant galectin when purified from the cleaved fusion protein. The recombinant galectin has a biphasic effect on cell proliferation. Unlike the fusion protein, it functions as a human cell growth inhibitor, confirming earlier findings with natural human galectin-1, though it is less effective than the natural galectin. This reaction is not significantly inhibited by lactose, and is thus largely independent of the beta-galactoside-binding site. At lower concentrations, recombinant galectin-1 is mitogenic, this activity being susceptible to inhibition by lactose, and thus attributable to the beta-galactoside-binding ability of the protein. Some tumour cells are susceptible to the growth-inhibitory effect, and the galectin-1 gene is expressed in both normal and tumour cells.

  2. Neutron Polarization Analysis for Biphasic Solvent Extraction Systems

    DOE PAGES

    Motokawa, Ryuhei; Endo, Hitoshi; Nagao, Michihiro; ...

    2016-06-16

    Here we performed neutron polarization analysis (NPA) of extracted organic phases containing complexes, comprised of Zr(NO3)4 and tri-n-butyl phosphate, which enabled decomposition of the intensity distribution of small-angle neutron scattering (SANS) into the coherent and incoherent scattering components. The coherent scattering intensity, containing structural information, and the incoherent scattering compete over a wide range of magnitude of scattering vector, q, specifically when q is larger than q* ≈ 1/Rg, where Rg is the radius of gyration of scatterer. Therefore, it is important to determine the incoherent scattering intensity exactly to perform an accurate structural analysis from SANS data when Rgmore » is small, such as the aforementioned extracted coordination species. Although NPA is the best method for evaluating the incoherent scattering component for accurately determining the coherent scattering in SANS, this method is not used frequently in SANS data analysis because it is technically challenging. In this study, we successfully demonstrated that experimental determination of the incoherent scattering using NPA is suitable for sample systems containing a small scatterer with a weak coherent scattering intensity, such as extracted complexes in biphasic solvent extraction systems.« less

  3. Comparison between FEBio and Abaqus for biphasic contact problems

    PubMed Central

    Jin, Zhongmin; Fisher, John; Wilcox, Ruth

    2013-01-01

    Articular cartilage plays an important role in the function of diarthrodial joints. Computational methods have been used to study the biphasic mechanics of cartilage, and Abaqus has been one of the most widely used commercial software packages for this purpose. A newly developed open-source finite element solver, FEBio, has been developed specifically for biomechanical applications. The aim of this study was to undertake a direct comparison between FEBio and Abaqus for some practical contact problems involving cartilage. Three model types, representing a porous flat-ended indentation test, a spherical-ended indentation test, and a conceptual natural joint contact model, were compared. In addition, a parameter sensitivity study was also performed for the spherical-ended indentation test to investigate the effects of changes in the input material properties on the model outputs, using both FEBio and Abaqus. Excellent agreement was found between FEBio and Abaqus for all of the model types and across the range of material properties that were investigated. PMID:23804955

  4. Biphasic effect of linoleic acid on connexin 46 hemichannels

    PubMed Central

    Evangelista-Martínez, Flavio; León-Paravic, Carmen G.; Altenberg, Guillermo A.; Reuss, Luis

    2011-01-01

    Connexins form hemichannels at undocked plasma membranes and gap-junction channels (GJCs) at intercellular contacting zones. Under physiological conditions, hemichannels have low open probabilities, but their activation under pathological conditions, such as ischemia, induces and/or accelerates cell death. Connexin 46 (Cx46) is a major connexin of the lens, and mutations of this connexin induce cataracts. Here, we report the effects of linoleic acid (LA) on the electrical properties of Cx46 GJCs and hemichannels expressed in Xenopus laevis oocytes. LA has a biphasic effect, increasing hemichannel current at 0.1 μM and decreasing it at concentrations of 100 μM or higher. The effects of extracellular and microinjected LA conjugated to coenzyme A (LA-CoA) suggest that the current activation site is accessible from the intracellular but not extracellular compartment, whereas the current inhibitory site is either located in a region of the hemichannel pore inaccessible to intracellular LA-CoA, or requires crossing of LA through an organelle membrane. Experiments with other fatty acids demonstrated that the block of hemichannels depends on the presence of a hydrogenated double bond at position 9 and is directly proportional to the number of double bonds. Experiments in paired oocytes expressing Cx46 showed that LA does not affect GJCs. The block by unsaturated fatty acids reported here opens the possibility that increases in the concentration of these lipids in the lens induce cataract formation by blocking Cx46 hemichannels. PMID:21360038

  5. Evolution of the optimum bidirectional (+/- biphasic) wave for defibrillation.

    PubMed

    Geddes, L A; Havel, W

    2000-01-01

    Introduction of the asymmetric bidirectional (+/- biphasic) current waveform has made it possible to achieve ventricular defibrillation with less energy and current than are needed with a unidirectional (monophasic) waveform. The symmetrical bidirectional (sinusoidal) waveform was used for the first human-heart defibrillation. Subsequent studies employed the underdamped and overdamped sine waves, then the trapezoidal (monophasic) wave. Studies were then undertaken to investigate the benefit of adding a second identical and inverted wave; little success rewarded these efforts until it was discovered that the second inverted wave needed to be much less in amplitude to lower the threshold for defibrillation. However, there is no physiologic theory that explains the mechanism of action of the bidirectional wave, nor does any theory predict the optimum amplitude and time dimensions for the second inverted wave. The authors analyze the research that shows that the threshold defibrillation energy is lowest when the charge in the second, inverted phase is slightly more than a third of that in the first phase. An ion-flux, spatial-K+ summation hypothesis is presented that shows the effect on myocardial cells of adding the second inverted current pulse.

  6. Biphasic Oxidation of Oxy-Hemoglobin in Bloodstains

    PubMed Central

    Bremmer, Rolf H.; de Bruin, Daniel M.; de Joode, Maarten; Buma, Wybren Jan; van Leeuwen, Ton G.; Aalders, Maurice C. G.

    2011-01-01

    Background In forensic science, age determination of bloodstains can be crucial in reconstructing crimes. Upon exiting the body, bloodstains transit from bright red to dark brown, which is attributed to oxidation of oxy-hemoglobin (HbO2) to met-hemoglobin (met-Hb) and hemichrome (HC). The fractions of HbO2, met-Hb and HC in a bloodstain can be used for age determination of bloodstains. In this study, we further analyze the conversion of HbO2 to met-Hb and HC, and determine the effect of temperature and humidity on the conversion rates. Methodology The fractions of HbO2, met-Hb and HC in a bloodstain, as determined by quantitative analysis of optical reflectance spectra (450–800 nm), were measured as function of age, temperature and humidity. Additionally, Optical Coherence Tomography around 1300 nm was used to confirm quantitative spectral analysis approach. Conclusions The oxidation rate of HbO2 in bloodstains is biphasic. At first, the oxidation of HbO2 is rapid, but slows down after a few hours. These oxidation rates are strongly temperature dependent. However, the oxidation of HbO2 seems to be independent of humidity, whereas the transition of met-Hb into HC strongly depends on humidity. Knowledge of these decay rates is indispensable for translating laboratory results into forensic practice, and to enable bloodstain age determination on the crime scene. PMID:21789186

  7. Neutron Polarization Analysis for Biphasic Solvent Extraction Systems

    SciTech Connect

    Motokawa, Ryuhei; Endo, Hitoshi; Nagao, Michihiro; Heller, William T.

    2016-06-16

    Here we performed neutron polarization analysis (NPA) of extracted organic phases containing complexes, comprised of Zr(NO3)4 and tri-n-butyl phosphate, which enabled decomposition of the intensity distribution of small-angle neutron scattering (SANS) into the coherent and incoherent scattering components. The coherent scattering intensity, containing structural information, and the incoherent scattering compete over a wide range of magnitude of scattering vector, q, specifically when q is larger than q* ≈ 1/Rg, where Rg is the radius of gyration of scatterer. Therefore, it is important to determine the incoherent scattering intensity exactly to perform an accurate structural analysis from SANS data when Rg is small, such as the aforementioned extracted coordination species. Although NPA is the best method for evaluating the incoherent scattering component for accurately determining the coherent scattering in SANS, this method is not used frequently in SANS data analysis because it is technically challenging. In this study, we successfully demonstrated that experimental determination of the incoherent scattering using NPA is suitable for sample systems containing a small scatterer with a weak coherent scattering intensity, such as extracted complexes in biphasic solvent extraction systems.

  8. Osteochondral tissue engineering with biphasic scaffold: current strategies and techniques.

    PubMed

    Shimomura, Kazunori; Moriguchi, Yu; Murawski, Christopher D; Yoshikawa, Hideki; Nakamura, Norimasa

    2014-10-01

    The management of osteoarthritis (OA) remains challenging and controversial. Although several clinical options exist for the treatment of OA, regeneration of the damaged articular cartilage has proved difficult due to the limited healing capacity. With the advancements in tissue engineering and cell-based technologies over the past decade, new therapeutic options for patients with osteochondral lesions potentially exist. This review will focus on the feasibility of tissue-engineered biphasic scaffolds, which can mimic the native osteochondral complex, for osteochondral repair and highlight the recent development of these techniques toward tissue regeneration. Moreover, basic anatomy, strategy for osteochondral repair, the design and fabrication methods of scaffolds, as well as the choice of cells, growth factor, and materials will be discussed. Specifically, we focus on the latest preclinical animal studies using large animals and clinical trials with high clinical relevance. In turn, this will facilitate an understanding of the latest trends in osteochondral repair and contribute to the future application of such clinical therapies in patients with OA.

  9. Neutron Polarization Analysis for Biphasic Solvent Extraction Systems

    SciTech Connect

    Motokawa, Ryuhei; Endo, Hitoshi; Nagao, Michihiro; Heller, William T.

    2016-06-16

    Here we performed neutron polarization analysis (NPA) of extracted organic phases containing complexes, comprised of Zr(NO3)4 and tri-n-butyl phosphate, which enabled decomposition of the intensity distribution of small-angle neutron scattering (SANS) into the coherent and incoherent scattering components. The coherent scattering intensity, containing structural information, and the incoherent scattering compete over a wide range of magnitude of scattering vector, q, specifically when q is larger than q* ≈ 1/Rg, where Rg is the radius of gyration of scatterer. Therefore, it is important to determine the incoherent scattering intensity exactly to perform an accurate structural analysis from SANS data when Rg is small, such as the aforementioned extracted coordination species. Although NPA is the best method for evaluating the incoherent scattering component for accurately determining the coherent scattering in SANS, this method is not used frequently in SANS data analysis because it is technically challenging. In this study, we successfully demonstrated that experimental determination of the incoherent scattering using NPA is suitable for sample systems containing a small scatterer with a weak coherent scattering intensity, such as extracted complexes in biphasic solvent extraction systems.

  10. Dynamin 2 regulates biphasic insulin secretion and plasma glucose homeostasis

    PubMed Central

    Fan, Fan; Ji, Chen; Wu, Yumei; Ferguson, Shawn M.; Tamarina, Natalia; Philipson, Louis H.; Lou, Xuelin

    2015-01-01

    Alterations in insulin granule exocytosis and endocytosis are paramount to pancreatic β cell dysfunction in diabetes mellitus. Here, using temporally controlled gene ablation specifically in β cells in mice, we identified an essential role of dynamin 2 GTPase in preserving normal biphasic insulin secretion and blood glucose homeostasis. Dynamin 2 deletion in β cells caused glucose intolerance and substantial reduction of the second phase of glucose-stimulated insulin secretion (GSIS); however, mutant β cells still maintained abundant insulin granules, with no signs of cell surface expansion. Compared with control β cells, real-time capacitance measurements demonstrated that exocytosis-endocytosis coupling was less efficient but not abolished; clathrin-mediated endocytosis (CME) was severely impaired at the step of membrane fission, which resulted in accumulation of clathrin-coated endocytic intermediates on the plasma membrane. Moreover, dynamin 2 ablation in β cells led to striking reorganization and enhancement of actin filaments, and insulin granule recruitment and mobilization were impaired at the later stage of GSIS. Together, our results demonstrate that dynamin 2 regulates insulin secretory capacity and dynamics in vivo through a mechanism depending on CME and F-actin remodeling. Moreover, this study indicates a potential pathophysiological link between endocytosis and diabetes mellitus. PMID:26413867

  11. Biphasic regulation of lysosomal exocytosis by oxidative stress.

    PubMed

    Ravi, Sreeram; Peña, Karina A; Chu, Charleen T; Kiselyov, Kirill

    2016-11-01

    Oxidative stress drives cell death in a number of diseases including ischemic stroke and neurodegenerative diseases. A better understanding of how cells recover from oxidative stress is likely to lead to better treatments for stroke and other diseases. The recent evidence obtained in several models ties the process of lysosomal exocytosis to the clearance of protein aggregates and toxic metals. The mechanisms that regulate lysosomal exocytosis, under normal or pathological conditions, are only beginning to emerge. Here we provide evidence for the biphasic effect of oxidative stress on lysosomal exocytosis. Lysosomal exocytosis was measured using the extracellular levels of the lysosomal enzyme beta-hexosaminidase (ß-hex). Low levels or oxidative stress stimulated lysosomal exocytosis, but inhibited it at high levels. Deletion of the lysosomal ion channel TRPML1 eliminated the stimulatory effect of low levels of oxidative stress. The inhibitory effects of oxidative stress appear to target the component of lysosomal exocytosis that is driven by extracellular Ca(2+). We propose that while moderate oxidative stress promotes cellular repair by stimulating lysosomal exocytosis, at high levels oxidative stress has a dual pathological effect: it directly causes cell damage and impairs damage repair by inhibiting lysosomal exocytosis. Harnessing these adaptive mechanisms may point to pharmacological interventions for diseases involving oxidative proteotoxicity or metal toxicity.

  12. Comparison between FEBio and Abaqus for biphasic contact problems.

    PubMed

    Meng, Qingen; Jin, Zhongmin; Fisher, John; Wilcox, Ruth

    2013-09-01

    Articular cartilage plays an important role in the function of diarthrodial joints. Computational methods have been used to study the biphasic mechanics of cartilage, and Abaqus has been one of the most widely used commercial software packages for this purpose. A newly developed open-source finite element solver, FEBio, has been developed specifically for biomechanical applications. The aim of this study was to undertake a direct comparison between FEBio and Abaqus for some practical contact problems involving cartilage. Three model types, representing a porous flat-ended indentation test, a spherical-ended indentation test, and a conceptual natural joint contact model, were compared. In addition, a parameter sensitivity study was also performed for the spherical-ended indentation test to investigate the effects of changes in the input material properties on the model outputs, using both FEBio and Abaqus. Excellent agreement was found between FEBio and Abaqus for all of the model types and across the range of material properties that were investigated.

  13. Biphasic Ngn3 expression in the developing pancreas

    PubMed Central

    Villasenor, Alethia; Chong, Diana C.; Cleaver, Ondine

    2008-01-01

    Ngn3 is a bHLH transcription factor critical for the specification of endocrine cells in the pancreatic Islets of Langerhans. Previous studies in mouse embryos have reported transient expression of Ngn3 in scattered cells within the developing pancreatic epithelium during midgestation (Schwitzgebel et al., 2000). Specifically, these Ngn3-expressing cells have been shown to be progenitor cells fated to give rise to islet endocrine cells (Gradwohl et al., 2000). Here, we characterize the expression of Ngn3 transcripts and protein throughout pancreatic development. Interestingly, we identify and define a dramatic and previously unnoticed gap in developmental Ngn3 expression. We show that both Ngn3 transcript and protein expression occur in two distinct temporal waves, the first occurring early from approximately E8.75 to E11.0, and the second initiating at approximately E12.0. Strikingly, this observed biphasic expression correlates with the ‘first’ and ‘second’ transitions, which encompass two distinct waves of embryonic endocrine differentiation. In addition, our studies demonstrate that Ngn3 transcripts are markedly more widespread in the pancreatic epithelium than NGN3 protein, indicating that post-transcriptional regulation is likely to play a critical role during endocrine differentiation. PMID:18924236

  14. Synthesis and Characterization of Environmentally Benign Nanoparticles

    EPA Science Inventory

    There has been a growing interest in replacing current non-biodegradable and toxic nanosystems with environmentally benign biopolymer based ones to minimize post-utilization hazards due to uncontrolled accumulation of nanoparticles in the environment. Lignin based nanoparticles (...

  15. ENVIRONMENTALLY-BENIGN MULTIPHASE CATALYSIS. (R826034)

    EPA Science Inventory

    Environmental concerns stemming from the use of conventional solvents and from hazardous waste generation have propelled research efforts aimed at developing benign chemical processing techniques that either eliminate or significantly mitigate pollution at the source. This pap...

  16. Synthesis and Characterization of Environmentally Benign Nanoparticles

    EPA Science Inventory

    There has been a growing interest in replacing current non-biodegradable and toxic nanosystems with environmentally benign biopolymer based ones to minimize post-utilization hazards due to uncontrolled accumulation of nanoparticles in the environment. Lignin based nanoparticles (...

  17. ENVIRONMENTALLY-BENIGN MULTIPHASE CATALYSIS. (R826034)

    EPA Science Inventory

    Environmental concerns stemming from the use of conventional solvents and from hazardous waste generation have propelled research efforts aimed at developing benign chemical processing techniques that either eliminate or significantly mitigate pollution at the source. This pap...

  18. Oxidative stress in benign prostate hyperplasia.

    PubMed

    Zabaiou, N; Mabed, D; Lobaccaro, J M; Lahouel, M

    2016-02-01

    To assess the status of oxidative stress in benign prostate hyperplasia, a very common disease in older men which constitutes a public health problem in Jijel, prostate tissues were obtained by transvesical adenomectomy from 10 men with benign prostate hyperplasia. We measured the cytosolic levels of malondialdehyde (MDA) and glutathione (GSH) and cytosolic enzyme activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferase. The development of benign prostate hyperplasia is accompanied by impaired oxidative status by increasing levels of MDA, depletion of GSH concentrations and a decrease in the activity of all the antioxidant enzymes studied. These results have allowed us to understand a part of the aetiology of benign prostate hyperplasia related to oxidative stress.

  19. Percutaneous ablation of benign bone tumors.

    PubMed

    Welch, Brian T; Welch, Timothy J

    2011-09-01

    Percutaneous image-guided ablation has become a standard of practice and one of the primary modalities for treatment of benign bone tumors. Ablation is most commonly used to treat osteoid osteomas but may also be used in the treatment of chondroblastomas, osteoblastomas, and giant cell tumors. Percutaneous image-guided ablation of benign bone tumors carries a high success rate (>90% in case series) and results in decreased morbidity, mortality, and expense compared with traditional surgical methods. The ablation technique most often applied to benign bone lesions is radiofrequency ablation. Because the ablation technique has been extensively applied to osteoid osteomas and because of the uncommon nature of other benign bone tumors, we will primarily focus this discussion on the percutaneous ablation of osteoid osteomas.

  20. Intra-abdominal benign multicystic peritoneal mesothelioma.

    PubMed

    Jouvin, I; Dohan, A; Gergi, P; Pocard, M

    2014-04-01

    Benign multicystic peritoneal mesotheliomas are rare: pre-operative diagnosis relies on proper imaging. The differential diagnosis includes pseudomyxoma peritonei and other peritoneal cysts. Absence of previous surgical resection offers the best chance of success when complete resection is performed in a specialized center. We report the case of a 43 year-old man with benign multicystic peritoneal mesothelioma treated by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Oral benign fibrous histiocytoma: two case reports

    PubMed Central

    2009-01-01

    Fibrous histiocytoma is a benign soft tissue tumour arising as a fibrous mass everywhere in the human body. The involvement of the oral cavity is rare. We report two cases of benign fibrous histiocytoma that localized in the oral cavity. The clinical and histological features of the lesion are reported. Finally, a literature revision of this pathology at the level of the oral cavity is reported. PMID:20066060

  2. Developing Quantitative In Vitro-In Vivo Correlation for Fenofibrate Immediate-Release Formulations With the Biphasic Dissolution-Partition Test Method.

    PubMed

    Xu, Hao; Shi, Yi; Vela, Socrates; Marroum, Patrick; Gao, Ping

    2017-06-27

    This study is to evaluate 3 fenofibrate (FEN) formulations including Fournier® 200 mg capsule, Lipidil® 145 mg tablet, and a clinical HME 160 mg tablet by an in vitro biphasic method. Key experimental parameters were evaluated including the selection of biorelevant media, the United States Pharmacopeia IV flow rate, and the United States Pharmacopeia paddle speed. Varying the hydrodynamic condition resulted in a significant impact on FEN concentration time profiles in both aqueous and octanol phases for these formulations. In vivo pharmacokinetic profiles of the HME tablet, the Lipidil tablet, and Fournier capsule under the fasting and low-fat fed states are reported. Their corresponding absorption-time profiles were obtained through deconvolution by the Wagner-Nelson method. When fed state simulated intestinal fluid version 2 was used, the partitioned FEN amount-time profiles in octanol from the 3 formulations under an appropriate hydrodynamic condition exhibited a good agreement with their in vivo absorbed amount-time profiles, permitting a quantitative in vitro-in vivo correlation. When fasted state simulated intestinal fluid version 2 was used, partitioned FEN amounts into octanol from these formulations are significantly lower than those from in vivo data. Although no food effect was observed for both HME and Lipidil tablets, the positive food effect of the Fournier capsules significantly overestimated by the biphasic test. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  3. Biphasic peptide amphiphile nanomatrix embedded with hydroxyapatite nanoparticles for stimulated osteoinductive response.

    PubMed

    Anderson, Joel M; Patterson, Jessica L; Vines, Jeremy B; Javed, Amjad; Gilbert, Shawn R; Jun, Ho-Wook

    2011-12-27

    Formation of the native bone extracellular matrix (ECM) provides an attractive template for bone tissue engineering. The structural support and biological complexity of bone ECM are provided within a composite microenvironment that consists of an organic fibrous network reinforced by inorganic hydroxyapatite (HA) nanoparticles. Recreating this biphasic assembly, a bone ECM analogous scaffold comprising self-assembling peptide amphiphile (PA) nanofibers and interspersed HA nanoparticles was investigated. PAs were endowed with biomolecular ligand signaling using a synthetically inscribed peptide sequence (i.e., RGDS) and integrated with HA nanoparticles to form a biphasic nanomatrix hydrogel. It was hypothesized the biphasic hydrogel would induce osteogenic differentiation of human mesenchymal stem cells (hMSCs) and improve bone healing as mediated by RGDS ligand signaling within PA nanofibers and embedded HA mineralization source. Viscoelastic stability of the biphasic PA hydrogels was evaluated with different weight concentrations of HA for improved gelation. After demonstrating initial viability, long-term cellularity and osteoinduction of encapsulated hMSCs in different PA hydrogels were studied in vitro. Temporal progression of osteogenic maturation was assessed by gene expression of key markers. A preliminary animal study demonstrated bone healing capacity of the biphasic PA nanomatrix under physiological conditions using a critical size femoral defect rat model. The combination of RGDS ligand signaling and HA nanoparticles within the biphasic PA nanomatrix hydrogel demonstrated the most effective osteoinduction and comparative bone healing response. Therefore, the biphasic PA nanomatrix establishes a well-organized scaffold with increased similarity to natural bone ECM with the prospect for improved bone tissue regeneration.

  4. Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

    DOEpatents

    Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

    2013-03-19

    A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

  5. Endobronchial ultrasound: morphological predictors of benign disease.

    PubMed

    Gogia, Pratibha; Insaf, Tabassum Z; McNulty, William; Boutou, Afroditi; Nicholson, Andrew G; Zoumot, Zaid; Shah, Pallav L

    2016-01-01

    The objective of this study was to assess the utility of endobronchial ultrasound (EBUS) morphology of lymph nodes in predicting benign cytology of transbronchial needle aspirates in a prospective observational study. Five ultrasonic morphological characteristics of mediastinal and hilar lymph nodes were recorded: size, shape, margins, echogenic appearance and the presence of a central blood vessel. These characteristics were correlated with the final diagnosis. A total of 402 consecutive patients (237 males and 165 females) undergoing EBUS were studied. The final diagnosis was malignant disease in 244 (60.6%) and benign disease in 153 (38.05%) subjects. Out of 740 sampled nodes, in 463 (62.6%) malignant cells were identified, whereas in 270 (36.5%) nodes, no malignant cells were identified. On univariate analysis small size, triangular shape and the presence of a central vessel were predictive of a benign aetiology. In the final multivariate model, a predictive probability of 0.811 (95% CI 0.72-0.91) for benign disease was found if lymph node size was <10 mm and a central vessel was present. Sonographic appearances of lymph nodes improve the predictive probability of EBUS for benign aetiologies, and may reduce the number of nodes requiring sampling and the need for further invasive investigations.

  6. Biotransformations of racemic 2,3-allenenitriles in biphasic systems: synthesis and transformations of enantioenriched axially chiral 2,3-allenoic acids and their derivatives.

    PubMed

    Ao, Yu-Fei; Wang, De-Xian; Zhao, Liang; Wang, Mei-Xiang

    2014-04-04

    Catalyzed by Rhodococcus erythropolis AJ270 whole cells in an aqueous phosphate buffer-n-hexane biphasic system, racemic axially chiral 2,3-allenenitriles underwent hydrolysis to afford enantioenriched (aR)-2,3-allenamides and (aS)-2,3-allenoic acids with ee's up to >99.5%. Overall biotransformations proceeded through the nitrile hydratase-catalyzed efficient but nonselective hydration of nitriles followed by the amide hydrolysis catalyzed by the substrate-dependent enantioselective amidase. The application of the method has been demonstrated by the transformations of the resulting allene products into highly functionalized heterocyclic compounds with axial chirality of reactants being entirely transferred into or expressed as point chirality of products.

  7. Low-cost industrially available molybdenum boride and carbide as "platinum-like" catalysts for the hydrogen evolution reaction in biphasic liquid systems.

    PubMed

    Scanlon, Micheál D; Bian, Xiaojun; Vrubel, Heron; Amstutz, Véronique; Schenk, Kurt; Hu, Xile; Liu, BaoHong; Girault, Hubert H

    2013-02-28

    Rarely reported low-cost molybdenum boride and carbide microparticles, both of which are available in abundant quantities due to their widespread use in industry, adsorb at aqueous acid-1,2-dichloroethane interfaces and efficiently catalyse the hydrogen evolution reaction in the presence of the organic electron donor - decamethylferrocene. Kinetic studies monitoring biphasic reactions by UV/vis spectroscopy, and further evidence provided by gas chromatography, highlight (a) their superior rates of catalysis relative to other industrially significant transition metal carbides and silicides, as well as a main group refractory compound, and (b) their highly comparable rates of catalysis to Pt microparticles of similar dimensions. Insight into the catalytic processes occurring for each adsorbed microparticle was obtained by voltammetry at the liquid-liquid interface.

  8. Percutaneous biphasic electrical stimulation for treatment of obstructive sleep apnea syndrome.

    PubMed

    Hu, Lianggang; Xu, Xiaomei; Gong, Yongsheng; Fan, Xiaofang; Wang, Liangxing; Zhang, Jianhua; Zeng, Yanjun

    2008-01-01

    In this paper, we study the effect of stimulation of the genioglossus with percutaneous biphasic electrical pulses on patients with the obstructive sleep apnea syndrome (OSAS). The experiment was conducted in 22 patients clinically diagnosed with OSAS. The patients were monitored with polysomnography (PSG) in the trial. When the sleep apnea was detected, the genioglossus was stimulated with percutaneous biphasic electrical pulses that were automatically regulated by a microcontroller to achieve the optimal effect. The percutaneous biphasic electrical stimulation caused contraction of the genioglossus, forward movement of the tongue, and relieving of the glossopharyngeal airway obstruction. The SaO2, apnea time, hypoxemia time, and change of respiratory disturbance index (RDI) were compared in patients with treatment and without treatment. With percutaneous biphasic electrical stimulation of the genioglossus, the OSAS patients showed apnea time decreased (P < 0.01), RDI decreased (P < 0.01), and SaO2 increased (P < 0.01). No tissue injury or major discomfort was noticed during the trial. The stimulation of genioglossus with percutaneous biphasic electrical current pulse is an effective method for treating OSAS.

  9. Distribution of cortical granules and meiotic maturation of canine oocytes in bi-phasic systems.

    PubMed

    Apparicio, Maricy; Mostachio, Giuliano Q; Motheo, Tathiana F; Alves, Aracelle E; Padilha, Luciana; Pires-Butler, Eliandra A; Savi, Paula A P; Uscategui, Ricardo A R; Luvoni, Gaia C; Vicente, Wilter R R

    2015-09-01

    The aim of this study was to evaluate the influence of different bi-phasic systems with gonadotrophins and steroids on in vitro maturation rates of oocytes obtained from bitches at different reproductive stages (follicular, luteal, anoestrous). In System A (control) oocytes were matured for 72h in base medium (BM) with 10IUmL(-1) human chorionic gonadotrophin (hCG), 1μgmL(-1) progesterone (P4) and 1μgmL(-1) oestradiol (E2); in bi-phasic System B oocytes were matured for 48h in BM with hCG and for 24h in BM with P4; in bi-phasic System C oocytes were matured for 48h in BM with hCG, P4 and E2, and for 24h in BM with P4; in System D, oocytes were cultured in BM without hormonal supplementation. Data were analysed by ANOVA. There was a positive effect of the bi-phasic systems on germinal vesicle breakdown, metaphase I and metaphase II rates, irrespective of reproductive status (P<0.05). Bi-phasic systems were also beneficial for cortical granule distribution (an indication of cytoplasmic maturation) and its relationship to nuclear status: 74.5% of the oocytes cultured in System B and 85.4% of those cultured in System C presented both nuclear and cytoplasmic maturation (P<0.001). The stage of the oestrous cycle did not influence maturation rates.

  10. A biphasic scaffold based on silk and bioactive ceramic with stratified properties for osteochondral tissue regeneration.

    PubMed

    Li, Jiao Jiao; Kim, Kyungsook; Roohani-Esfahani, Seyed-Iman; Guo, Jin; Kaplan, David L; Zreiqat, Hala

    2015-07-14

    Significant clinical challenges encountered in the effective long-term treatment of osteochondral defects have inspired advancements in scaffold-based tissue engineering techniques to aid repair and regeneration. This study reports the development of a biphasic scaffold produced via a rational combination of silk fibroin and bioactive ceramic with stratified properties to satisfy the complex and diverse regenerative requirements of osteochondral tissue. Structural examination showed that the biphasic scaffold contained two phases with different pore morphologies to match the cartilage and bone segments of osteochondral tissue, which were joined at a continuous interface. Mechanical assessment showed that the two phases of the biphasic scaffold imitated the load-bearing behaviour of native osteochondral tissue and matched its compressive properties. In vitro testing showed that different compositions in the two phases of the biphasic scaffold could direct the preferential differentiation of human mesenchymal stem cells towards the chondrogenic or osteogenic lineage. By featuring simple and reproducible fabrication and a well-integrated interface, the biphasic scaffold strategy established in this study circumvented the common problems experienced with integrated scaffold designs and could provide an effective approach for the regeneration of osteochondral tissue.

  11. Small biphase wellhead plant for the Cerro Prieto Mexico geothermal field

    SciTech Connect

    Oropeza, A.; Hays, L.

    1996-12-31

    In a system of geothermal wells in a geothermal field, there are different production conditions of the flows, temperatures and pressures. At plants where the installed capacity requires the use of many wells, it is necessary to regulate the well`s pressure to ensure a stable condition for the turbines. Reducing the steam pressure on the wellhead is achieved by using an orifice plate (flash orifice). Use of an orifice plate results in a waste or loss of well pressure that could be utilized for production of electricity. The Cerro Prieto field, operated by the Comision Federal de Electricidad (CFE), has many wells operating at a very high pressure and producing a lot of water. Much of this pressure and water is not utilized in the production of electricity. With the purpose of taking advantage of this pressure CFE has evaluated a proposal by Biphase Energy Co. Biphase has designed and patented a turbine that works directly with the steam and water mixture coming from the wellhead, acting as a separator. Biphase has developed a model of its turbine and successfully operated it in Coso Hot Springs California. Knowing this CFE has signed an agreement with Biphase Energy Company to install and operate a biphasic turbine at the Cerro Prieto geothermal field located near Mexicali, Mexico.

  12. Evaluation of the finite element software ABAQUS for biomechanical modelling of biphasic tissues.

    PubMed

    Wu, J Z; Herzog, W; Epstein, M

    1998-02-01

    The biphasic cartilage model proposed by Mow et al. (1980) has proven successful to capture the essential mechanical features of articular cartilage. In order to analyse the joint contact mechanics in real, anatomical joints, the cartilage model needs to be implemented into a suitable finite element code to approximate the irregular surface geometries of such joints. However, systematic and extensive evaluation of the capacity of commercial software for modelling the contact mechanics with biphasic cartilage layers has not been made. This research was aimed at evaluating the commercial finite element software ABAQUS for analysing biphasic soft tissues. The solutions obtained using ABAQUS were compared with those obtained using other finite element models and analytical solutions for three numerical tests: an unconfined indentation test, a test with the contact of a spherical cartilage surface with a rigid plate, and an axi-symmetric joint contact test. It was concluded that the biphasic cartilage model can be implemented into the commercial finite element software ABAQUS to analyse practical joint contact problems with biphasic articular cartilage layers.

  13. Benign multicystic mesothelioma: a case report.

    PubMed

    Adolph, A J; Smith, T E; Adolph, J

    2002-03-01

    Benign multicystic mesothelioma (also known as multilocular peritoneal inclusion cyst) is a rare lesion found on any abdominal peritoneal surface that occurs most frequently in premenopausal women. We report the case of a 36-year- old woman, who presented with a history of generalized abdominal pain, intermittent abdominal bloating, and episodes of loose stools. A pelvic ultrasound revealed a complex cystic mass with fine internal septations. The patient was managed by laparotomy with removal of mass, total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and multiple peritoneal biopsies. Final pathology revealed benign multicystic mesothelioma. Although mesothelioma is a rare tumour, it is important for all gynaecologists to recognize its existence, the appearance of this lesion, and its generally benign course. This is especially important as it occurs in young women where fertility considerations must be part of the discussion of any pelvic surgery.

  14. Benign multicystic peritoneal mesothelioma: a case report

    PubMed Central

    2010-01-01

    Introduction We report the case of a patient with a benign multicystic peritoneal mesothelioma and describe its appearance on computed tomography scans and ultrasonography, in correlation with gross clinical and pathological findings. Case presentation A 72-year-old Caucasian woman presented to our emergency department with acute abdomen signs and symptoms. A clinical examination revealed a painful palpable mass in her left abdomen. Abdominal ultrasonography and computed tomography demonstrated the presence of a large cystic mass in her left upper abdomen, adjacent to her left hemidiaphragm. The lower border of the mass extended to the upper margin of her pelvis. A complete resection of the lesion was performed. Pathological analysis showed a benign multicystic peritoneal mesothelioma. Conclusions Benign multicystic peritoneal mesothelioma is a rare lesion with a non-specific appearance on imaging. Its diagnosis always requires pathological analysis. PMID:21114811

  15. Benign multicystic peritoneal mesothelioma: a case report.

    PubMed

    Pitta, Xanthi; Andreadis, Efstathios; Ekonomou, Athanasios; Papachristodoulou, Athanasia; Tziouvaras, Chrisostomos; Papapaulou, Leonidas; Sapidis, Nikolaos; Chrisidis, Thomas

    2010-11-29

    We report the case of a patient with a benign multicystic peritoneal mesothelioma and describe its appearance on computed tomography scans and ultrasonography, in correlation with gross clinical and pathological findings. A 72-year-old Caucasian woman presented to our emergency department with acute abdomen signs and symptoms. A clinical examination revealed a painful palpable mass in her left abdomen. Abdominal ultrasonography and computed tomography demonstrated the presence of a large cystic mass in her left upper abdomen, adjacent to her left hemidiaphragm. The lower border of the mass extended to the upper margin of her pelvis. A complete resection of the lesion was performed. Pathological analysis showed a benign multicystic peritoneal mesothelioma. Benign multicystic peritoneal mesothelioma is a rare lesion with a non-specific appearance on imaging. Its diagnosis always requires pathological analysis.

  16. Benign bone tumors--recent developments.

    PubMed

    Garcia, Roberto A; Inwards, Carrie Y; Unni, Krishnan K

    2011-02-01

    Benign bone tumors frequently pose a diagnostic challenge for general surgical pathologists. Accurate pathologic diagnosis requires careful clinical and radiological correlation. The most significant recent advances in some benign bone tumors have occurred at the molecular and cytogenetic level. The detection of clonal chromosomal aberrations, various specific molecular genetic events, and the description of the bone cell signaling pathways in the field of osteoimmunology have provided a better understanding of the pathophysiology of certain tumors and an important aid in the diagnostic workup and differential diagnosis of some bone lesions demonstrating overlapping clinical and pathologic features. Future directions include prognostic and therapeutic applications of these findings. Newer less invasive therapeutic techniques and medical management have been developed for the treatment of certain benign bone tumors.

  17. Uncommon Benign Breast Abnormalities in Adolescents

    PubMed Central

    Warren, Rebekkah; Degnim, Amy C.

    2013-01-01

    The authors discuss benign breast abnormalities in the adolescent breast other than fibroadenoma. Although fibroadenoma is the most common benign abnormality in the adolescent breast, other diagnoses are possible. The majority of adolescents who present with a palpable concern or lump have no discrete abnormality on ultrasound and are diagnosed with clinical fibrocystic change and followed up to ensure clinical stability. Intraductal papilloma and duct ectasia are two benign abnormalities associated with bloody nipple discharge, occurring more rarely in adolescents compared with adult women. Breast infections can occur in adolescents, including both mastitis and/or abscess, and are treated similarly to adults, with drainage and antibiotic coverage for Staphylococcus. When infections are due to nipple piercing, other organisms should be suspected. All surgical procedures in the developing breast should be performed cautiously, as trauma to the undeveloped breast can result in failure of breast development or asymmetry, and surgical disruption of subareolar ducts can impair or preclude future lactation. PMID:24872736

  18. [Modern pharmacotherapy of benign prostatic hyperplasia].

    PubMed

    Krysiak, Robert; Okopień, Bogusław; Szkróbka, Witold; Herman, Zbigniew Stanisław

    2005-11-01

    Benign prostatic hyperplasia is the most common medical problem affecting elderly men throughout the world. With increasing awareness of health issues amongst males, the morbidity caused by this disease is not longer being accepted as just part of growing old. Until about 10 years ago, surgery was the only effective treatment for symptomatic benign prostatic hyperplasia. Now, many men suffering from this disorder may be effectively treated with a medical therapy. This article provides an overview of the efficacy and safety of 5alpha-reductase inhibitors, alpha1-adrenoceptor antagonists and herbal remedies, putting special emphasis on the current place of these agents in the modem therapy of benign prostatic hyperplasia. Wherever possible, our opinion is based on the detailed analysis of the results of available clinical trials.

  19. Finasteride for benign prostatic hyperplasia.

    PubMed

    Tacklind, James; Fink, Howard A; Macdonald, Roderick; Rutks, Indy; Wilt, Timothy J

    2010-10-06

    Benign prostatic hyperplasia (BPH), a non-malignant enlargement of the prostate in aging men, can cause bothersome urinary symptoms (intermittency, weak stream, straining, urgency, frequency, incomplete emptying). Finasteride, a five-alpha reductase inhibitor (5ARI), blocks the conversion of testosterone to dihydrotestosterone, reduces prostate size, and is commonly used to treat symptoms associated with BPH. To compare the clinical effectiveness and harms of finasteride versus placebo and active controls in the treatment of lower urinary tract symptoms (LUTS). We searched The Cochrane Library (which includes CDSR (Cochrane Database of Systematic Reviews), DARE (Database of Abstracts of Reviews of Effects), HTA (Heath Technology Assessments), and CENTRAL (Cochrane Central Register of Controlled Trials, and which includes EMBASE and MEDLINE), LILACS (Latin American and Caribbean Center on Health Sciences Information) and Google Scholar for randomized, controlled trials (RCTs). We also handsearched systematic reviews, references, and clinical-practice guidelines. Randomized trials in the English language with placebo and/or active arms with a duration of at least 6 months. JT extracted the data, which included patient characteristics, outcomes, and harms. Our primary outcome was change in a validated, urinary symptom-scale score, such as the AUA/IPSS. A clinically meaningful change was defined as 4 points. We also categorized outcomes by trial lengths of ≤ 1 year (short term) and > 1 year (long term). Finasteride consistently improved urinary symptom scores more than placebo in trials of > 1 year duration, and significantly lowered the risk of BPH progression (acute urinary retention, risk of surgical intervention, ≥ 4 point increase in the AUASI/IPSS). In comparison to alpha-blocker monotherapy, finasteride was less effective than either doxazosin or terazosin, but equally effective compared to tamsulosin. Both doxazosin and terazosin were significantly more

  20. Osteoid osteoma and benign osteoblastoma in childhood.

    PubMed Central

    Black, J A; Levick, R K; Sharrard, W J

    1979-01-01

    Three cases of osteoid osteoma and one of benign osteoblastoma in children are described. The main complaint was severe pain which was worse at night; it was relieved by aspirin or other analgesics. The diagnosis was made on clinical and radiological grounds and was confirmed on histological examination of the central nidus removed at operation. The pain was relieved in the patients with osteoid osteoma, and it was very much less after operative removal of the benign osteoblastoma. Both conditions are probably variations of the same disease process, depending on the anatomical site and the type of bone affected. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:475430

  1. Benign Cystic Mesothelioma Misdiagnosed as Peritoneal Carcinomatosis

    PubMed Central

    Shin, Hyun Deok; Kim, Suk Bae

    2016-01-01

    Benign cystic mesothelioma (BCM) is a rare benign disease that forms multicystic masses in the abdomen, pelvis, and retroperitoneum. It occurs predominantly in young to middle-aged women. The majority of cases were associated with a history of abdominal or pelvic operation, a history of endometriosis, and pelvic inflammatory disease. We present a unique case of BCM which is different to the previous cases. The patient was a 52-year-old man showing features of peritoneal carcinomatosis accompanied by ascites on abdominal computed tomography scans. We herein report a case of BCM misdiagnosed with peritoneal carcinomatosis. PMID:27403112

  2. Radiofrequency ablation for benign thyroid nodules.

    PubMed

    Bernardi, S; Stacul, F; Zecchin, M; Dobrinja, C; Zanconati, F; Fabris, B

    2016-09-01

    Benign thyroid nodules are an extremely common occurrence. Radiofrequency ablation (RFA) is gaining ground as an effective technique for their treatment, in case they become symptomatic. Here we review what are the current indications to RFA, its outcomes in terms of efficacy, tolerability, and cost, and also how it compares to the other conventional and experimental treatment modalities for benign thyroid nodules. Moreover, we will also address the issue of treating with this technique patients with cardiac pacemakers (PM) or implantable cardioverter-defibrillators (ICD), as it is a rather frequent occurrence that has never been addressed in detail in the literature.

  3. A finite element implementation for biphasic contact of hydrated porous media under finite deformation and sliding

    PubMed Central

    Guo, Hongqiang; Shah, Mitul; Spilker, Robert L.

    2014-01-01

    The study of biphasic soft tissues contact is fundamental to understanding the biomechanical behavior of human diarthrodial joints. However, to date, few biphasic finite element contact analysis for 3D physiological geometries under finite deformation has been developed. The objective of this paper is to develop a hyperelastic biphasic contact implementation for finite deformation and sliding problem. An augmented Lagrangian method was used to enforce the continuity of contact traction and fluid pressure across the contact interface. The finite element implementation was based on a general purpose software, COMSOL Multiphysics. The accuracy of the implementation is verified using example problems, for which solutions are available by alternative analyses. The implementation was proven to be robust and able to handle finite deformation and sliding. PMID:24496915

  4. Pretreatment of Eucalyptus in biphasic system for furfural production and accelerated enzymatic hydrolysis.

    PubMed

    Zhang, Xiudong; Bai, Yuanyuan; Cao, Xuefei; Sun, Runcang

    2017-08-01

    Herein, an efficient biphasic pretreatment process was developed to improve the production of furfural (FF) and glucose from Eucalyptus. The influence of formic acid and NaCl on FF production from xylose in water and various biphasic systems was investigated. Results showed that the addition of formic acid and NaCl significantly promoted the FF yield, and the biphasic system of MIBK (methyl isobutyl ketone)/water exhibited the best performance for FF production. Then the Eucalyptus was pretreated in the MIBK/water system, and a maximum FF yield of 82.0% was achieved at 180°C for 60min. Surface of the pretreated Eucalyptus became relatively rough and loose, and its crystallinity index increased obviously due to the removal of hemicelluloses and lignin. The pretreated Eucalyptus samples showed much higher enzymatic hydrolysis rates (26.2-70.7%) than the raw Eucalyptus (14.5%). Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    SciTech Connect

    Bragard, Jean Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Fenton, Flavio H.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.

    2013-12-15

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one–dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 10{sup 6} simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

  6. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    NASA Astrophysics Data System (ADS)

    Bragard, Jean; Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.; Fenton, Flavio H.

    2013-12-01

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one-dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 106 simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

  7. Therapeutic efficacy of endostatin exhibits a biphasic dose-response curve.

    PubMed

    Celik, Ilhan; Sürücü, Oguzkan; Dietz, Carsten; Heymach, John V; Force, Jeremy; Höschele, Iris; Becker, Christian M; Folkman, Judah; Kisker, Oliver

    2005-12-01

    We show here that recombinant endostatin protein has a biphasic effect on the inhibition of endothelial cell migration in vitro. In tumor-bearing animals, there is a similar biphasic effect on the inhibition of tumor growth and on circulating endothelial cells after once-daily s.c. injections. This biphasic effect is revealed as a U-shaped curve in which efficacy is optimal between very low and very high doses depending on the tumor type. This result may be applicable to other inhibitors of endothelial growth and to angiogenesis. Furthermore, these results have important implications for clinicians who administer angiogenesis inhibitors for cancer or other angiogenesis-dependent diseases. When these results are taken together with two previous reports of angiogenesis inhibitors with a U-shaped dose-response, they suggest that other regulators of endothelial growth may display a similar pattern.

  8. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    PubMed Central

    Bragard, Jean; Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.; Fenton, Flavio H.

    2013-01-01

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one–dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 106 simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation. PMID:24387558

  9. Photoinduced biphasic hydrogen evolution: decamethylosmocene as a light-driven electron donor.

    PubMed

    Ge, Peiyu; Olaya, Astrid J; Scanlon, Micheál D; Hatay Patir, Imren; Vrubel, Heron; Girault, Hubert H

    2013-07-22

    Excitation of the weak electron donor decamethylosmocene on illumination with white light produces an excited-state species capable of reducing organically solubilized protons under biphasic conditions. Insight into the mechanism and kinetics of light-driven biphasic hydrogen evolution are obtained by analysis with gas chromatography, cyclic voltammetry, and UV/Vis and (1)H NMR spectroscopy. Formation of decamethylosmocenium hydride, which occurs prior to hydrogen evolution, is a rapid step relative to hydrogen release and takes place independently of light activation. Remarkably, hydride formation occurs with greater efficiency (ca. 90% conversion) under biphasic conditions than when the reaction is carried out in an acidified single organic phase (ca. 20% conversion). Cyclic voltammetry studies reveal that decamethylosmocene has a higher proton affinity than either decamethylferrocene or osmocene.

  10. Biphasic Dependence of Glioma Survival and Cell Migration on CD44 Expression Level.

    PubMed

    Klank, Rebecca L; Decker Grunke, Stacy A; Bangasser, Benjamin L; Forster, Colleen L; Price, Matthew A; Odde, Thomas J; SantaCruz, Karen S; Rosenfeld, Steven S; Canoll, Peter; Turley, Eva A; McCarthy, James B; Ohlfest, John R; Odde, David J

    2017-01-03

    While several studies link the cell-surface marker CD44 to cancer progression, conflicting results show both positive and negative correlations with increased CD44 levels. Here, we demonstrate that the survival outcomes of genetically induced glioma-bearing mice and of high-grade human glioma patients are biphasically correlated with CD44 level, with the poorest outcomes occurring at intermediate levels. Furthermore, the high-CD44-expressing mesenchymal subtype exhibited a positive trend of survival with increased CD44 level. Mouse cell migration rates in ex vivo brain slice cultures were also biphasically associated with CD44 level, with maximal migration corresponding to minimal survival. Cell simulations suggest that cell-substrate adhesiveness is sufficient to explain this biphasic migration. More generally, these results highlight the potential importance of non-monotonic relationships between survival and biomarkers associated with cancer progression.

  11. Investigation of the feasibility of a biphase turbine for industrial process energy recovery. Final report

    SciTech Connect

    Helgeson, N.

    1985-06-28

    Tests were conducted to assess the technical applicability of the Biphase turbine to two process streams. A Biphase impulse turbine was tested on a flashing Selexol stream used for removal of CO/sub 2/ from process gases. The experimental results showed that the two-phase nozzle performance of the flashing Selexol stream was substantially below equilibrium calculation predictions. Consequently, the turbine power generated by this expanding two-phase flow was below predicted values, and was approximately equivalent to the liquid hydraulic power available. Additional gas-liquid phase separation occurred on the rotor such that overall separation efficiency reached 98% of that which occurred in the long residence time settling tank (equilibrium). The Biphase reaction turbine was tested on a flashing natural gas/crude oil stream. Nozzle, rotary and overall turbine performance were in good agreement with pre-test predictions for power generation and efficiency of operation. 141 figs., 35 tabs.

  12. Dissolved nutrients and atrazine removal by column-scale monophasic and biphasic rain garden model systems.

    PubMed

    Yang, Hanbae; McCoy, Edward L; Grewal, Parwinder S; Dick, Warren A

    2010-08-01

    Rain gardens are bioretention systems that have the potential to reduce peak runoff flow and improve water quality in a natural and aesthetically pleasing manner. We compared hydraulic performance and removal efficiencies of nutrients and atrazine in a monophasic rain garden design versus a biphasic design at a column-scale using simulated runoff. The biphasic rain garden was designed to increase retention time and removal efficiency of runoff pollutants by creating a sequence of water saturated to unsaturated conditions. We also evaluated the effect of C substrate availability on pollutant removal efficiency in the biphasic rain garden. Five simulated runoff events with various concentrations of runoff pollutants (i.e. nitrate, phosphate, and atrazine) were applied to the monophasic and biphasic rain gardens once every 5d. Hydraulic performance was consistent over the five simulated runoff events. Peak flow was reduced by approximately 56% for the monophasic design and 80% for the biphasic design. Both rain garden systems showed excellent removal efficiency of phosphate (89-100%) and atrazine (84-100%). However, significantly (p<0.001) higher removal of nitrate was observed in the biphasic (42-63%) compared to the monophasic rain garden (29-39%). Addition of C substrate in the form of glucose increased removal efficiency of nitrate significantly (p<0.001), achieving up to 87% removal at a treatment C/N ratio of 2.0. This study demonstrates the importance of retention time, environmental conditions (i.e. saturated/unsaturated conditions), and availability of C substrate for bioremediation of pollutants, especially nitrates, in rain gardens. (c) 2010 Elsevier Ltd. All rights reserved.

  13. A Structurally and Functionally Biomimetic Biphasic Scaffold for Intervertebral Disc Tissue Engineering

    PubMed Central

    Choy, Andrew Tsz Hang; Chan, Barbara Pui

    2015-01-01

    Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering. PMID:26115332

  14. Citrate-Based Biphasic Scaffolds for the Repair of Large Segmental Bone Defects

    PubMed Central

    Guo, Ying; Tran, Richard T.; Xie, Denghui; Nguyen, Dianna Y.; Gerhard, Ethan; Guo, Jinshan; Wang, Yuchen; Tang, Jiajun; Zhang, Zhongming; Bai, Xiaochun; Yang, Jian

    2014-01-01

    Attempts to replicate native tissue architecture have lead to the design of biomimetic scaffolds focused on improving functionality. In this study, biomimetic citrate-based poly (octanediol citrate) – click hydroxyapatite (POC-Click-HA) scaffolds were developed to simultaneously replicate the compositional and architectural properties of native bone tissue while providing immediate structural support for large segmental defects following implantation. Biphasic scaffolds were fabricated with 70% internal phase porosity and various external phase porosities (between 5–50%) to mimic the bimodal distribution of cancellous and cortical bone, respectively. Biphasic POC-Click-HA scaffolds displayed compressive strengths up to 37.45 ± 3.83 MPa, which could be controlled through the external phase porosity. The biphasic scaffolds were also evaluated in vivo for the repair of 10-mm long segmental radial defects in rabbits and compared to scaffolds of uniform porosity as well as autologous bone grafts after 5, 10, and 15 weeks of implantation. The results showed that all POC-Click-HA scaffolds exhibited good biocompatibility and extensive osteointegration with host bone tissue. Biphasic scaffolds significantly enhanced new bone formation with higher bone densities in the initial stages after implantation. Biomechanical and histomorphometric analysis supported a similar outcome with biphasic scaffolds providing increased compression strength, interfacial bone ingrowth, and periosteal remodeling in early time points, but were comparable to all experimental groups after 15 weeks. These results confirm the ability of biphasic scaffold architectures to restore bone tissue and physiological functions in the early stages of recovery, and the potential of citrate-based biomaterials in orthopedic applications. PMID:24829094

  15. Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak

    PubMed Central

    Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.

    2016-01-01

    Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the

  16. Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak.

    PubMed

    Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J; Eisner, David A; Venetucci, Luigi

    2016-02-01

    Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay. In the presence of β-adrenergic stimulation, RyR-mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase. Two forms of Ca leak have been studied, Ca-sensitising (induced by caffeine) and non-sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient. Only Ca-sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine. Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca-sensitising and non-sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca(2+)]i with fluo-3 in voltage-clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non-sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca(2+)]i , increased diastolic [Ca(2+)]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l(-1)) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the biphasic decay was replaced by slow

  17. Facts for Life: Benign Breast Changes

    MedlinePlus

    ... tests are needed to make a diagnosis. Warning signs of breast cancer See a doctor if you notice any of ... of lump is found, it may be a sign of a benign breast condition or breast cancer. If you find a lump in your breast, ...

  18. Huge benign mesenchymoma in pharynx-esophagus.

    PubMed

    Li, Jun; Omo, Alfred; Liu, Ligang; Liu, Lisi; Tang, Yinxiong; Pan, Tiecheng

    2006-06-01

    Benign mesenchymoma is an uncommon neoplastic disease and its occurrence in pharynx-esophagus is even more rarely reported. A successful case operation is reported. The origin of this tumor was in the pharynx-esophagus, and complete excision was achieved through a laterocervical approach.

  19. Imaging features of benign adrenal cysts.

    PubMed

    Sanal, Hatice Tuba; Kocaoglu, Murat; Yildirim, Duzgun; Bulakbasi, Nail; Guvenc, Inanc; Tayfun, Cem; Ucoz, Taner

    2006-12-01

    Benign adrenal gland cysts (BACs) are rare lesions with a variable histological spectrum and may mimic not only each other but also malignant ones. We aimed to review imaging features of BACs which can be helpful in distinguishing each entity and determining the subsequent appropriate management.

  20. Unusual Benign Tumors of the Breast

    PubMed Central

    Adrada, Beatriz E; Krishnamurthy, Savitri; Carkaci, Selin; Posleman-Monetto, Flavia E; Ewere, Adesuwa; Whitman, Gary J

    2015-01-01

    The purpose of this article is to describe the imaging characteristics of a variety of benign breast tumors that may be encountered in daily practice, in order to formulate an appropriate differential diagnosis and to establish concordance between the imaging and the pathologic findings, and to assist the clinician with appropriate management. PMID:26085959

  1. Congenital epulis: A rare benign tumour.

    PubMed

    Wong, D K C; Ramli, R; Muhaizan, W M; Primuharsa Putra, S H A

    2016-10-01

    Congenital epulis is a rare benign pedunculated tumour of the oral cavity arising from the alveolar ridges. It is usually detected in newborns and can be successfully resected surgically. We report a case of a newborn baby who had a 5x3x3cm pedunculated lobar mass arising from the upper alveolar ridge.

  2. Benign Prostatic Hyperplasia: from Bench to Clinic

    PubMed Central

    Cho, Hee Ju

    2012-01-01

    Benign prostatic hyperplasia (BPH) is a prevalent disease, especially in old men, and often results in lower urinary tract symptoms (LUTS). This chronic disease has important care implications and financial risks to the health care system. LUTS are caused not only by mechanical prostatic obstruction but also by the dynamic component of obstruction. The exact etiology of BPH and its consequences, benign prostatic enlargement and benign prostatic obstruction, are not identified. Various theories concerning the causes of benign prostate enlargement and LUTS, such as metabolic syndrome, inflammation, growth factors, androgen receptor, epithelial-stromal interaction, and lifestyle, are discussed. Incomplete overlap of prostatic enlargement with symptoms and obstruction encourages focus on symptoms rather than prostate enlargement and the shifting from surgery to medicine as the treatment of BPH. Several alpha antagonists, including alfuzosin, doxazosin, tamsulosin, and terazosin, have shown excellent efficacy without severe adverse effects. In addition, new alpha antagonists, silodosin and naftopidil, and phosphodiesterase 5 inhibitors are emerging as BPH treatments. In surgical treatment, laser surgery such as photoselective vaporization of the prostate and holmium laser prostatectomy have been introduced to reduce complications and are used as alternatives to transurethral resection of the prostate (TURP) and open prostatectomy. The status of TURP as the gold standard treatment of BPH is still evolving. We review several preclinical and clinical studies about the etiology of BPH and treatment options. PMID:22468207

  3. Pulmonary metastases from benign calvarial meningioma: a case report.

    PubMed

    Cho, Byung-Rae; Yoon, Wan-Soo

    2017-04-01

    The most common intracranial tumour is meningioma, which rarely presents with extracranial metastasis, especially in benign cases. We report a case of meningioma recurrence with multiple pulmonary metastases in a patient who had a benign meningioma removed 12 years prior.

  4. A pilot trial of square biphasic pulse deep brain stimulation for dystonia: The BIP dystonia study.

    PubMed

    Almeida, Leonardo; Martinez-Ramirez, Daniel; Ahmed, Bilal; Deeb, Wissam; Jesus, Sol De; Skinner, Jared; Terza, Matthew J; Akbar, Umer; Raike, Robert S; Hass, Chris J; Okun, Michael S

    2017-04-01

    Dystonia often has inconsistent benefits and requires more energy-demanding DBS settings. Studies suggest that squared biphasic pulses could provide significant clinical benefit; however, dystonia patients have not been explored. To assess safety and tolerability of square biphasic DBS in dystonia patients. This study included primary generalized or cervical dystonia patients with bilateral GPi DBS. Square biphasic pulses were implemented and patients were assessed at baseline, immediately postwashout, post-30-minute washout, 1 hour post- and 2 hours postinitiation of investigational settings. Ten participants completed the study. There were no patient-reported or clinician-observed side effects. There was improvement across time on the Toronto Western Spasmodic Torticollis Rating Scale (χ(2)  = 10.7; P = 0.031). Similar improvement was detected in objective gait measurements. Square biphasic stimulation appears safe and feasible in dystonia patients with GPi DBS. Further studies are needed to evaluate possible effectiveness particularly in cervical and gait features. © 2016 International Parkinson and Movement Disorder Society. © 2017 International Parkinson and Movement Disorder Society.

  5. Modeling Biphasic Environmental Decay of Pathogens and Implications for Risk Analysis.

    PubMed

    Brouwer, Andrew F; Eisenberg, Marisa C; Remais, Justin V; Collender, Philip A; Meza, Rafael; Eisenberg, Joseph N S

    2017-02-21

    As the appreciation for the importance of the environment in infectious disease transmission has grown, so too has interest in pathogen fate and transport. Fate has been traditionally described by simple exponential decay, but there is increasing recognition that some pathogens demonstrate a biphasic pattern of decay-fast followed by slow. While many have attributed this behavior to population heterogeneity, we demonstrate that biphasic dynamics can arise through a number of plausible mechanisms. We examine the identifiability of a general model encompassing three such mechanisms: population heterogeneity, hardening off, and the existence of viable-but-not-culturable states. Although the models are not fully identifiable from longitudinal sampling studies of pathogen concentrations, we use a differential algebra approach to determine identifiable parameter combinations. Through case studies using Cryptosporidium and Escherichia coli, we show that failure to consider biphasic pathogen dynamics can lead to substantial under- or overestimation of disease risks and pathogen concentrations, depending on the context. More reliable models for environmental hazards and human health risks are possible with an improved understanding of the conditions in which biphasic die-off is expected. Understanding the mechanisms of pathogen decay will ultimately enhance our control efforts to mitigate exposure to environmental contamination.

  6. Engineering anisotropic biphasic Janus-type polymer nanofiber scaffold networks via centrifugal jet spinning.

    PubMed

    Khang, Alex; Ravishankar, Prashanth; Krishnaswamy, Aditya; Anderson, Patrick K; Cone, Stephanie G; Liu, Zizhao; Qian, Xianghong; Balachandran, Kartik

    2017-11-01

    Biphasic materials, comprised of an ordered arrangement of two different material phases within a material, have the potential for a wide variety of applications including filtration, protective clothing and tissue engineering. This study reports for the first time, a process for engineering biphasic Janus-type polymeric nanofiber (BJPNF) networks via the centrifugal jet spinning technique. BJPNF alignment and fiber diameter was dependent on fabrication rotational speed as well as solution composition. The biphasic character of these BJPNFs, which was controlled via the rotational speed of fabrication, was confirmed at the individual nanofiber scale using energy dispersive X-ray spectroscopy, and at the bulk, macro-scale using attenuated total reflectance-Fourier transform infrared spectroscopy. Biphasic character was also demonstrated at the functional level via differing affinities on either side of the BJPNF for cell attachment. Our work thus presents a method for fabricating BJPNF scaffold networks where there might be a need for different properties on either side of a material. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2455-2464, 2017. © 2016 Wiley Periodicals, Inc.

  7. Biphasic Electrical Field Stimulation Aids in Tissue Engineering of Multicell-Type Cardiac Organoids

    PubMed Central

    Chiu, Loraine L.Y.; Iyer, Rohin K.; King, John-Paul

    2011-01-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence. PMID:18783322

  8. Biphasic electrical field stimulation aids in tissue engineering of multicell-type cardiac organoids.

    PubMed

    Chiu, Loraine L Y; Iyer, Rohin K; King, John-Paul; Radisic, Milica

    2011-06-01

    The main objectives of current work were (1) to compare the effects of monophasic or biphasic electrical field stimulation on structure and function of engineered cardiac organoids based on enriched cardiomyocytes (CM) and (2) to determine if electrical field stimulation will enhance electrical excitability of cardiac organoids based on multiple cell types. Organoids resembling cardiac myofibers were cultivated in Matrigel-coated microchannels fabricated of poly(ethylene glycol)-diacrylate. We found that field stimulation using symmetric biphasic square pulses at 2.5 V/cm, 1 Hz, 1 ms (per pulse phase) was an improved stimulation protocol, as compared to no stimulation and stimulation using monophasic square pulses of identical total amplitude and duration (5 V/cm, 1 Hz, 2 ms). This was supported by the highest success rate for synchronous contractions, low excitation threshold, the highest cell density, and the highest expression of Connexin-43 in the biphasic group. Subsequently, enriched CM were seeded on the networks of (1) cardiac fibroblasts (FB), (2) D4T endothelial cells (EC), or (3) a mixture of FB and EC that were precultured for 2 days prior to the addition of enriched CM. Biphasic field stimulation was also effective at improving electrical excitability of these cardiac organoids by improving the three-dimensional organization of the cells, increasing cellular elongation and enhancing Connexin-43 presence.

  9. Strontium substituted calcium phosphate biphasic ceramics obtained by a powder precipitation method.

    PubMed

    Kim, Hae-Won; Koh, Young-Hag; Kong, Young-Min; Kang, Jun-Gu; Kim, Hyoun-Ee

    2004-10-01

    Strontium (Sr) substituted calcium phosphate ceramics were fabricated using a powder precipitation method. The Sr ions were added up to 8 mol % to replace the Ca ions during the powder preparation. Composition analysis showed that the added Sr was not fully incorporated within the as-precipitated apatite structure, presumably being washed out during the powder preparation. After calcination, the Sr containing powders were crystallized into apatite and tricalcium phosphate (TCP), that is, biphasic calcium phosphates were formed. The amount of TCP increased with increasing the Sr addition. The lattice parameters of the calcined powders increased gradually with Sr substitution in both the a- and c-axis. However, the obtained values deviated slightly from the calculated ones at higher Sr additions (>4%) due to the partial substitution of Sr ions. The microstructure of the sintered bodies changed with the Sr addition due to the formation of TCP. The Vickers hardness increased slightly from 5.2 to 5.5 MPa with increasing Sr addition, which was driven by the HA+TCP biphasic formation. The osteoblast-like cells cultured on the Sr-substituted biphasic sample spread and grew actively. The proliferation rate of the cells was higher in the samples containing more Sr. The alkaline phosphate activity of the cells was expressed to a higher degree with increasing Sr addition. These observations confirmed the enhanced cell viability and differentiation of the Sr-substituted biphasic calcium phosphate ceramics.

  10. Hydroxyapatite/polylactide biphasic combination scaffold loaded with dexamethasone for bone regeneration.

    PubMed

    Son, Jun-Sik; Kim, Su-Gwan; Oh, Ji-Su; Appleford, Mark; Oh, Sunho; Ong, Joo L; Lee, Kyu-Bok

    2011-12-15

    This study presents a novel design of a ceramic/polymer biphasic combination scaffold that mimics natural bone structures and is used as a bone graft substitute. To mimic the natural bone structures, the outside cortical-like shells were composed of porous hydroxyapatite (HA) with a hollow interior using a polymeric template-coating technique; the inner trabecular-like core consisted of porous poly(D,L-lactic acid) (PLA) that was loaded with dexamethasone (DEX) and was directly produced using a particle leaching/gas forming technique to create the inner diameter of the HA scaffold. It was observed that the HA and PLA parts of the fabricated HA/PLA biphasic scaffold contained open and interconnected pore structures, and the boundary between both parts was tightly connected without any gaps. It was found that the structure of the combination scaffold was analogous to that of natural bone based on micro-computed tomography analysis. Additionally, the dense, uniform apatite layer was formed on the surface of the HA/PLA biphasic scaffold through a biomimetic process, and DEX was successfully released from the PLA of the biphasic scaffold over a 1-month period. This release caused human embryonic palatal mesenchyme cells to proliferate, differentiate, produce ECM, and form tissue in vitro. Therefore, it was concluded that this functionally graded scaffold is similar to natural bone and represents a potential bone-substitute material.

  11. Biphasic Dose Response in Low Level Light Therapy – An Update

    PubMed Central

    Huang, Ying-Ying; Sharma, Sulbha K; Carroll, James; Hamblin, Michael R

    2011-01-01

    Low-level laser (light) therapy (LLLT) has been known since 1967 but still remains controversial due to incomplete understanding of the basic mechanisms and the selection of inappropriate dosimetric parameters that led to negative studies. The biphasic dose-response or Arndt-Schulz curve in LLLT has been shown both in vitro studies and in animal experiments. This review will provide an update to our previous (Huang et al. 2009) coverage of this topic. In vitro mediators of LLLT such as adenosine triphosphate (ATP) and mitochondrial membrane potential show biphasic patterns, while others such as mitochondrial reactive oxygen species show a triphasic dose-response with two distinct peaks. The Janus nature of reactive oxygen species (ROS) that may act as a beneficial signaling molecule at low concentrations and a harmful cytotoxic agent at high concentrations, may partly explain the observed responses in vivo. Transcranial LLLT for traumatic brain injury (TBI) in mice shows a distinct biphasic pattern with peaks in beneficial neurological effects observed when the number of treatments is varied, and when the energy density of an individual treatment is varied. Further understanding of the extent to which biphasic dose responses apply in LLLT will be necessary to optimize clinical treatments. PMID:22461763

  12. A novel benign solution for collagen processing

    NASA Astrophysics Data System (ADS)

    Arnoult, Olivier

    Collagen is the main protein constituting the extracellular matrix (ECM) of tissues in the body (skin, cartilage, blood vessels...). It exists many types of collagen, this work studies only fibrillar collagen (e.g. collagen type I contained in the skin) that exhibits a triple helical structure composed of 3 alpha-helical collagen chains. This particular and defined hierarchical structure is essential to the biological and mechanical properties of the collagen. Processing collagen into scaffolds to mimic the ECM is crucial for successful tissue engineering. Recently collagen was processed into fibrous and porous scaffold using electrospinning process. However the solvent (HFIP) used for electrospinning is extremely toxic for the user and expensive. This work shows that HFIP can be replaced by a benign mixture composed of water, salt and alcohol. Yet only three alcohols (methanol, ethanol and iso-propanol) enable the dissolution of large quantity of collagen in the benign mixture, with a wide range of alcohol to buffer ratio, and conserve the collagen hierarchical structure at least as well as the HFIP. Collagen can be electrospun from the benign mixture into sub-micron fibers with concentrations as low as 6 wt-% for a wide range of alcohol to buffer ratio, with at least 10wt-% of salt, and any of the three alcohols. Specific conditions yield nano size fibers. After processing from HFIP or a benign mixture, collagen is water soluble and needs to be chemically crosslink for tissue engineering application. Post-crosslinking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) results in the loss of the scaffold fibrous aspect and porosity, hence it is useless for tissue engineering. Such issue could be prevented by incorporating the crosslinker into the mixture prior to electrospinning. When EDC is used alone, collagen forms a gel in the mixture within minutes, preventing electrospinning. The addition of N-hydroxysuccinimide (NHS) in excess to EDC

  13. TEMPERATURE EFFECTS ON POLYMER-BASED AQUEOUS BIPHASIC EXTRACTION TECHNOLOGY IN THE PAPER PULPING PROCESS. (R826732)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. A comparison between mechano-electrochemical and biphasic swelling theories for soft hydrated tissues.

    PubMed

    Wilson, W; van Donkelaar, C C; Huyghe, J M

    2005-02-01

    Biological tissues like intervertebral discs and articular cartilage primarily consist of interstitial fluid, collagen fibrils and negatively charged proteoglycans. Due to the fixed charges of the proteoglycans, the total ion concentration inside the tissue is higher than in the surrounding synovial fluid (cation concentration is higher and the anion concentration is lower). This excess of ion particles leads to an osmotic pressure difference, which causes swelling of the tissue. In the last decade several mechano-electrochemical models, which include this mechanism, have been developed. As these models are complex and computationally expensive, it is only possible to analyze geometrically relatively small problems. Furthermore, there is still no commercial finite element tool that includes such a mechano-electrochemical theory. Lanir (Biorheology, 24, pp. 173-187, 1987) hypothesized that electrolyte flux in articular cartilage can be neglected in mechanical studies. Lanir's hypothesis implies that the swelling behavior of cartilage is only determined by deformation of the solid and by fluid flow. Hence, the response could be described by adding a deformation-dependent pressure term to the standard biphasic equations. Based on this theory we developed a biphasic swelling model. The goal of the study was to test Lanir's hypothesis for a range of material properties. We compared the deformation behavior predicted by the biphasic swelling model and a full mechano-electrochemical model for confined compression and 1D swelling. It was shown that, depending on the material properties, the biphasic swelling model behaves largely the same as the mechano-electrochemical model, with regard to stresses and strains in the tissue following either mechanical or chemical perturbations. Hence, the biphasic swelling model could be an alternative for the more complex mechano-electrochemical model, in those cases where the ion flux itself is not the subject of the study. We propose

  15. Benign paroxysmal positional vertigo following septorhinoplasty.

    PubMed

    Koc, Eltaf Ayca Ozbal; Koc, Bulent; Eryaman, Esra; Ozluoglu, Levent N

    2013-01-01

    We present 2 cases of benign paroxysmal positional vertigo (BPPV) following septorhinoplasty. Benign paroxysmal positional vertigo following septorhinoplasty is an unusual entity. Two young women who had difficulty in breathing and nasal deformity underwent septorhinoplasty. On the second and the third postoperative days, the patients experienced vertigo that was induced by position changes. Both patients had neither preexisting ear disease nor vertigo before the surgery. All the examinations were normal. With Dix-Hallpike maneuver, which is the criterion-standard test, the characteristic nystagmus was observed. Right posterior canal BPPV was diagnosed, and they were both treated with Epley canalith repositioning maneuver. Publications related to postsurgical vertigo are available in literature, but it is still an underdiagnosed disorder. We would like to mention about this rare entity and inform the surgeons that they must keep in mind that a patient who is complaining about vertigo or dizziness after the surgery should be observed and investigated for BPPV.

  16. [Benign multicystic peritoneal mesothelioma. A case report].

    PubMed

    Lari, Federico; Castelli, Giuliano; Bragagni, Gianpaolo

    2012-02-01

    Benign multicystic peritoneal mesothelioma is a rare malignancy with unknown etiology, first described in 1980, which have been reported to date about 150 cases in the literature. Although the term "benign", used mainly to distinguish it from the classic malignant mesothelioma, a more aggressive cancer, is considered "borderline" in terms of aggression: it tends to local recurrence but cases of lymph node metastases or in other locations at a distance are not described. The symptoms are often vague and nonspecific (abdominal pain, enlarged abdomen and ascites). The common diagnostic imaging techniques (CT, MRI) may appear similar to ovarian or peritoneal cancer by more aggressive mesenchymal neoplasms. Histological examination, accurately with the aid of immunohistochemical techniques, is therefore essential for diagnosis. Treatment is surgical and consists of peritonectomy. After surgery, the prognosis is generally good. In 50% of cases may have local recurrences; so rigorous follow-up is indicated.

  17. Laser Thermal Ablation of Thyroid Benign Nodules

    PubMed Central

    Shahrzad, Mohammad Karim

    2015-01-01

    Thermal ablation therapies for benign thyroid nodules have been introduced in recent years to avoid the complications of traditional methods such as surgery. Despite the little complications and the reportedly acceptable efficacy of thermal ablation methods, quite few medical centers have sought the potential benefits of employing them. This paper provides an introduction to the literature, principles and advances of Percutaneous Laser Ablation therapy of thyroid benign nodules, as well as a discussion on its efficacy, complications and future. Several clinical research papers evaluating the thermal effect of laser on the alleviation of thyroid nodules have been reviewed to illuminate the important points. The results of this research can help researchers to advance the approach and medical centers to decide on investing in these novel therapies. PMID:26705459

  18. Laser Thermal Ablation of Thyroid Benign Nodules.

    PubMed

    Shahrzad, Mohammad Karim

    2015-01-01

    Thermal ablation therapies for benign thyroid nodules have been introduced in recent years to avoid the complications of traditional methods such as surgery. Despite the little complications and the reportedly acceptable efficacy of thermal ablation methods, quite few medical centers have sought the potential benefits of employing them. This paper provides an introduction to the literature, principles and advances of Percutaneous Laser Ablation therapy of thyroid benign nodules, as well as a discussion on its efficacy, complications and future. Several clinical research papers evaluating the thermal effect of laser on the alleviation of thyroid nodules have been reviewed to illuminate the important points. The results of this research can help researchers to advance the approach and medical centers to decide on investing in these novel therapies.

  19. Benign recurrent VI nerve palsy in childhood.

    PubMed

    Bixenman, W W; von Noorden, G K

    1981-01-01

    The case of a child with six documented episodes of benign recurrent unilateral VI nerve palsy between the ages of 2 1/2 months and 3 years is presented. Despite the recognized self-limiting course of this disorder, its possible evolution into a comitant esotropia makes close follow-up mandatory. The practical aspects of management including maintenance occlusion therapy are stressed as well as the need for prompt surgical intervention once the acquired stabismus has become stabilized. The etiology of benign VI nerve palsy of childhood may have the same immunological basis as other cases of para-infectious neuropathy. This isolated postinfective cranial mononeuropathy easily blends into the continuum of neurological involvement seen with the Landry-Guillian-Barre syndrome. With recovery from the initial episode, the abducens nerve may have become predisposed to recurrent inflammatory episodes and recurrent loss of function. Most often these recurrences are triggered by febrile illnesses of childhood.

  20. [Benign intraperitoneal metastatic leiomyomatosis: A case report].

    PubMed

    García, Paz; Errázuriz, Juan Ignacio; Fernández, Carlos; Arteaga, Eugenio

    2017-02-01

    Benign intraperitoneal metastatic leiomyomatosis is a rare benign disease that is observed when a leiomyoma is present in the peritoneal surface. Women who have undergone hysterectomy for leiomyomas are most commonly affected. Patients are usually asymptomatic at presentation, being frequently an incidental finding in imaging studies. Ultrasound and CT play an important role in the diagnosis. The lesions are histologically identical to their uterine counterparts. There are different theories about the pathogenesis of the disease, including peritoneal seeding after laparoscopic hysterectomy. Others support the hypothesis of multiple independent foci of smooth muscle proliferation. Treatment, as in uterine leiomyomatosis, is generally conservative. We report a 53-year-old hysterectomized woman with intraperitoneal leiomyomas detected in a routine physical examination as mobile abdominal masses who underwent successful laparoscopic resection.

  1. [Surgical treatment of benign paroxysmal positional vertigo].

    PubMed

    Zaugg, Y; Grosjean, P; Maire, R

    2012-10-03

    Benign paroxysmal positional vertigo (BPPV) is a common disorder that presents to the general practitioner. This condition represents one of the most common causes of peripheral vertigo. The diagnosis is made on clinical grounds. The treatment relies on repositioning maneuvers with relief of symptoms that occur in a few weeks in the majority of the cases. Rarely, patients are incapacitated by persistent or recurrent BPPV despite multiple repositioning maneuvers. In these cases, surgical therapies are available which provide excellent results.

  2. [Benign prostatic hypertrophy and prostate cancer].

    PubMed

    Mourey, Loïc; Doumerc, Nicolas; Gaudin, Clément; Gérard, Stéphane; Balardy, Laurent

    2014-01-01

    Prostatic diseases are extremely common, especially in older men. Amongst them, benign prostatic hypertrophy may affect significantly the quality of life of patients by the symptoms it causes. It requires appropriate care. Prostate cancer is the second most common cancer in men after lung cancer and the fifth leading cause of cancer deaths in the world. It affects preferentially older men. An oncogeriatric approach is required for personalised care.

  3. Hemorrhagic, calcified, and ossified benign retroperitoneal schwannoma

    PubMed Central

    Xu, Shao-Yan; Sun, Ke; Xie, Hai-Yang; Zhou, Lin; Zheng, Shu-Sen; Wang, Wei-Lin

    2016-01-01

    Abstract Background: Schwannomas are mesenchymal tumors arising from the neural sheaths of peripheral nerves. They can almost develop in any part of the body, while head, neck and extremities are the most common sites. Occurrence in the retroperitoneum is rare. Schwannomas can show secondary degenerative changes including cyst formation, hyalinization, hemorrhage, and calcification, whereas the ossified retroperitoneal schwannoma was only reported in a malignant one. Case summary: We first present a benign ossified retroperitoneal schwannoma in a 61-year-old female. The mass was found by a routine health examination. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a well-defined mass in the area among duodenum, right liver, and kidney. Definitive preoperative diagnosis of the mass was difficult. By laparotomy, the mass was found in the retroperitoneum. We completely removed the tumor and gross specimen showed a mass with a capsule and 6 × 6 × 4.8 cm in size. Microscopic examination showed the tumor is composed of spindle-shaped cells with degenerative changes of hemorrhage, calcification, and ossification. Immunohistochemically, S-100 protein was strongly positive. Finally, the mass was diagnosed as a hemorrhagic, calcified, and ossified benign schwannoma in the retroperitoneum. The patient was followed up for a period of 21 months, during which she was well with no evidence of recurrence. Conclusion: We report the first case of a benign retroperitoneal schwannoma with secondary degenerative changes including hemorrhage, calcification, and ossification. Precise preoperative diagnosis of the tumor is challenging even with multiple preoperative imaging modalities. After complete resection, patients with benign retroperitoneal schwanommas generally have good prognosis. PMID:27472709

  4. Surgical treatment of benign endobronchial tumours

    PubMed Central

    Halttunen, P; Meurala, H; Standertskjöld-Nordenstam, C-G

    1982-01-01

    Four cases of benign endobronchial tumour are reported which were successfully treated by bronchial resection. In two cases (of fibroma and leiomyoma respectively) a cylinder of bronchus alone was resected; in one case (lipoma) a healthy right upper lobe was preserved by a bronchoplastic procedure and in the other (chondroma) the tumour was removed with the right lower lobe, which was irreversibly damaged. It is important to recognise that such tumours are unsuitable for treatment by endoscopic means alone. Images PMID:7157223

  5. Preventing medical errors by designing benign failures.

    PubMed

    Grout, John R

    2003-07-01

    One way to successfully reduce medical errors is to design health care systems that are more resistant to the tendencies of human beings to err. One interdisciplinary approach entails creating design changes, mitigating human errors, and making human error irrelevant to outcomes. This approach is intended to facilitate the creation of benign failures, which have been called mistake-proofing devices and forcing functions elsewhere. USING FAULT TREES TO DESIGN FORCING FUNCTIONS: A fault tree is a graphical tool used to understand the relationships that either directly cause or contribute to the cause of a particular failure. A careful analysis of a fault tree enables the analyst to anticipate how the process will behave after the change. EXAMPLE OF AN APPLICATION: A scenario in which a patient is scalded while bathing can serve as an example of how multiple fault trees can be used to design forcing functions. The first fault tree shows the undesirable event--patient scalded while bathing. The second fault tree has a benign event--no water. Adding a scald valve changes the outcome from the undesirable event ("patient scalded while bathing") to the benign event ("no water") Analysis of fault trees does not ensure or guarantee that changes necessary to eliminate error actually occur. Most mistake-proofing is used to prevent simple errors and to create well-defended processes, but complex errors can also result. The utilization of mistake-proofing or forcing functions can be thought of as changing the logic of a process. Errors that formerly caused undesirable failures can be converted into the causes of benign failures. The use of fault trees can provide a variety of insights into the design of forcing functions that will improve patient safety.

  6. Management of familial benign chronic pemphigus

    PubMed Central

    Arora, Harleen; Bray, Fleta N; Cervantes, Jessica; Falto Aizpurua, Leyre A

    2016-01-01

    Benign familial chronic pemphigus or Hailey–Hailey disease is caused by an autosomal dominant mutation in the ATP2C1 gene leading to suprabasilar acantholysis. The disease most commonly affects intertriginous areas symmetrically. The chronic nature of the disease and multiple recurrences make the disease bothersome for patients and a treatment challenge for physicians. Treatments include topical and/or systemic agents and surgery including laser. This review summarizes the available treatment options. PMID:27695354

  7. Laparoscopic resection of retroperitoneal benign neurilemmoma

    PubMed Central

    Park, Joon Seong; Kang, Chang Moo; Yoon, Dong Sup; Lee, Woo Jung

    2017-01-01

    Purpose The aim of this study was to verify that laparoscopic resection for treating retroperitoneal benign neurilemmoma (NL) is expected to be favorable for complete resection of tumor with technical feasibility and safety. Methods We retrospectively analyzed 47 operations for retroperitoneal neurogenic tumor at Yonsei University College of Medicine, Severance Hospital and Gangnam Severance Hospital between January 2005 and September 2015. After excluding 21 patients, the remaining 26 were divided into 2 groups: those who underwent open surgery (OS) and those who underwent laparoscopic surgery (LS). We compared clinicopathological features between the 2 groups. Results There was no significant difference in operation time, estimated blood loss, transfusion, complication, recurrence, or follow-up period between 2 groups. Postoperative hospital stay was significantly shorter in the LS group versus the OS group (OS vs. LS, 7.00 ± 3.43 days vs. 4.50 ± 2.16 days; P = 0.031). Conclusion We suggest that laparoscopic resection of retroperitoneal benign NL is feasible and safe by obtaining complete resection of the tumor. LS for treating retroperitoneal benign NL could be useful with appropriate laparoscopic technique and proper patient selection. PMID:28289669

  8. Environmentally benign silicon solar cell manufacturing

    SciTech Connect

    Tsuo, Y.S.; Gee, J.M.; Menna, P.; Strebkov, D.S.; Pinov, A.; Zadde, V.

    1998-09-01

    The manufacturing of silicon devices--from polysilicon production, crystal growth, ingot slicing, wafer cleaning, device processing, to encapsulation--requires many steps that are energy intensive and use large amounts of water and toxic chemicals. In the past two years, the silicon integrated-circuit (IC) industry has initiated several programs to promote environmentally benign manufacturing, i.e., manufacturing practices that recover, recycle, and reuse materials resources with a minimal consumption of energy. Crystalline-silicon solar photovoltaic (PV) modules, which accounted for 87% of the worldwide module shipments in 1997, are large-area devices with many manufacturing steps similar to those used in the IC industry. Obviously, there are significant opportunities for the PV industry to implement more environmentally benign manufacturing approaches. Such approaches often have the potential for significant cost reduction by reducing energy use and/or the purchase volume of new chemicals and by cutting the amount of used chemicals that must be discarded. This paper will review recent accomplishments of the IC industry initiatives and discuss new processes for environmentally benign silicon solar-cell manufacturing.

  9. POLYSTYRENE SULFONIC ACID CATALYZED GREENER SYNTHESIS OF HYDRAZONES IN AQUEOUS MEDIUM USING MICROWAVES

    EPA Science Inventory

    An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any organic solvent under mi...

  10. POLYSTYRENE SULFONIC ACID CATALYZED GREENER SYNTHESIS OF HYDRAZONES IN AQUEOUS MEDIUM USING MICROWAVES

    EPA Science Inventory

    An environmentally benign aqueous protocol for the synthesis of cyclic, bi-cyclic, and heterocyclic hydrazones using polystyrene sulfonic acid (PSSA) as a catalyst has been developed; the simple reaction proceeds efficiently in water in the absence of any organic solvent under mi...

  11. Synthesis of silver nanoparticles in textile finish aqueous system and their antimicrobial properties on cotton fibers

    USDA-ARS?s Scientific Manuscript database

    Silver nanoparticles (NPs) were synthesized by a simple and environmentally benign procedure using poly (ethylene glycol) (PEG) as reducing agent and stabilizer in the textile finish aqueous system, and their antimicrobial properties on greige (mechanically cleaned) and bleached cotton fibers were i...

  12. Synthesis of furfural from xylose, xylan, and biomass using AlCl3·6H2O in biphasic media via xylose isomerization to xylulose.

    PubMed

    Yang, Yu; Hu, Chang-Wei; Abu-Omar, Mahdi M

    2012-02-13

    Furfural was prepared in high yields (75 %) from the reaction of xylose in a water-tetrahydrofuran biphasic medium containing AlCl(3)·6H2O and NaCl under microwave heating at 140 °C. The reaction profile revealed the formation of xylulose as an intermediate en route to the dehydration product (furfural). The reaction under these conditions reached completion in 45 min. The aqueous phase containing AlCl(3)·6H(2)O and NaCl could be recycled multiple times (>5) without any loss of activity or selectivity for furfural. Extension of this biphasic reaction system to include xylan as the starting material afforded furfural in 64 % yield. The use of corn stover, pinewood, switchgrass, and poplar gave furfural in 55, 38, 56, and 64 % yield, respectively, at 160 °C. Even though AlCl(3)·6H(2)O did not affect the conversion of crystalline cellulose, moderate yields of the by-product 5-hydroxymethylfurfural (HMF) were noted. The highest HMF yield of 42 % was obtained from pinewood. The coproduction of HMF and furfural from biomass was attributed to the weakening of the cellulose network in the biomass, as a result of hemicellulose hydrolysis. The multifunctional capacity of AlCl(3)·6H(2)O (hemicellulose hydrolysis, xylose isomerization, and xylulose dehydration) in combination with its ease of recyclability make it an attractive candidate/catalyst for the selective synthesis of furfural from various biomass feedstocks. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Efficacy of transthoracic cardioversion of atrial fibrillation using a biphasic, truncated exponential shock waveform at variable initial shock energies.

    PubMed

    Rashba, Eric J; Gold, Michael R; Crawford, Fred A; Leman, Robert B; Peters, Robert W; Shorofsky, Stephen R

    2004-12-15

    Biphasic shocks are more effective than damped sine wave monophasic shocks for transthoracic cardioversion (CV) of atrial fibrillation (AF), but the optimal protocol for CV with biphasic shocks has not been defined. We conducted a prospective, randomized study of 120 consecutive patients with persistent AF to delineate the dose-response curve for CV of AF with a biphasic truncated exponential shock waveform and to identify clinical predictors of shock efficacy. Our data suggest that the initial shock energy for CV with this waveform should be 200 J if the patient weighs <90 kg and 360 J if the patient weighs >/=90 kg.

  14. Process for recovering pertechnetate ions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, R.; Horwitz, E.P.; Bond, A.H.

    1997-02-18

    A solid/liquid process for the separation and recovery of TcO{sub 4}{sup {minus}1} ions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups; whereas the aqueous solution from which the TcO{sub 4}{sup {minus}1} ions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt. A solid/liquid phase admixture of separation particles containing bound TcO{sub 4}{sup {minus}1} ions in such an aqueous solution that is free from MoO{sub 4}{sup {minus}2} ions is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture. 15 figs.

  15. Process for recovering pertechnetate ions from an aqueous solution also containing other ions

    DOEpatents

    Rogers, Robin; Horwitz, E. Philip; Bond, Andrew H.

    1997-01-01

    A solid/liquid process for the separation and recovery of TcO.sub.4.sup.-1 ions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups; whereas the aqueous solution from which the TcO.sub.4.sup.-1 ions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt. A solid/liquid phase admixture of separation particles containing bound TcO.sub.4.sup.-1 ions in such an aqueous solution that is free from MoO.sub.4.sup.-2 ions is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture.

  16. Bi-phasic growth of Listeria monocytogenes in chemically defined medium at low temperatures.

    PubMed

    Tyrovouzis, Nikolaos A; Angelidis, Apostolos S; Stoforos, Nikolaos G

    2014-09-01

    The present work reports a novel observation regarding the growth of L. monocytogenes in modified Welshimer's broth (MWB) at low temperatures. Specifically, the direct monitoring of the growth of L. monocytogenes Scott A using plate count data revealed that the pathogen displays a bi-phasic growth pattern in MWB at 7 °C. This bi-phasic growth pattern is masked (not observed) when optical density (OD) measurements are used to monitor growth due to the inability of OD readings to detect L. monocytogenes population density increases up to 10(7) CFU/mL. This bi-phasic growth phenomenon was further investigated as a function of growth temperature (4 °C, 7 °C, 10 °C, 14 °C and 18 °C), medium composition (by altering the MWB composition by ten-fold increases in different sets of medium constituents), inoculum level (10(2), 10(3), 10(4), 10(5), 10(6), and 10(7) CFU/mL) and L. monocytogenes strain (10 strains). The growth of L. monocytogenes Scott A in MWB at 7 °C, 10 °C and 14 °C was consistently bi-phasic and independent of growth rate; at 18 °C, growth was consistently mono-phasic (single-phase, typical sigmoid growth curves), whereas no growth was observed at 4 °C. The tested modifications in the composition of MWB did not influence the bi-phasic nature of L. monocytogenes Scott A growth at 7 °C, and, overall, we could not point out any strain-, or serotype-specific effects. On the other hand, the initial inoculum level appears to affect the form of the growth curve, as there was a shift towards mono-phasic growth in trials with increasing initial inocula. A mathematical model, based on a stepwise response and described through two sequential sigmoid curves, was used to describe bi-phasic growth and estimate the kinetic parameters of L. monocytogenes growth. An alternative hypothesis, based on the assumption of the existence of two subpopulations, possessing different growth kinetics, materialized under the stress imposed on L. monocytogenes cells due to the

  17. CONTROLLING THE AQUEOUS MISCIBILITY OF IONIC LIQUIDS: A NOVEL AQUEOUS BIPHASIC SYSTEM FROM WATER-MISCIBLE IONIC LIQUID AND A WATER-STRUCTURING SALT. (R828257)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  18. Laser applications for benign oral lesions.

    PubMed

    Frigerio, Alice; Tan, Oon T

    2015-10-01

    Different subspecialists treat benign intraoral lesions using various approaches including surgical excision, medical therapy, sclerotherapy, and laser photocoagulation. The goal of this study was to establish whether lasers could effectively target and destroy oral lesions containing endogenous chromophores, while minimizing injury to unaffected adjacent tissues and critical structures. This retrospective study involved 26 cases of benign oral lesions, both vascular and pigmented, which were addressed by means of selective laser treatment. Pathologies were port-wine stains, hereditary hemorragic teleangectasia, hemangiomas, venous and arteriovenous malformations, pyogenic granuloma, and hairy reconstructive flaps. Electronic medical records and photographic documentation were reviewed. Three blinded staff personnel not involved with patient care in this study evaluated photographs taken prior to the first and after the final laser treatments. Observers rated the percentage clearance of the lesions or the ablation of bleeding, and the assessed values were averaged for each patient. An average of 30-95% lightening was observed in the intraoral port-wine stains, 90% in the hemangiomas, 70% in arteriovenous malformations, 81% for venous malformations, 86% for venous lakes, and 100% for the pyogenic granuloma. Bleeding was ablated in all hereditary hemorrhagic telangiectasia lesions treated using the pulsed dye laser with or without the Alexandrite laser. Intraoral hair growing on the skin paddle of microvascular flaps was completely removed in one of the three cases treated using the Alexandrite laser. In the two remaining cases, some hair removal was achieved, but because the residual hairs were grey or white (absence of melanocytic chromophore), photocoagulation was less effective. Lasers are a safe and effective means to selectively destroy specific chromphores. Such specific targeting ensures complete destruction of pathological tissue, decreasing the possibility

  19. Efficacy and safety of biphasic insulin aspart and biphasic insulin lispro mix in patients with type 2 diabetes: A review of the literature

    PubMed Central

    Kumar, Ajay

    2016-01-01

    Type 2 diabetes (T2D) represents an escalating burden worldwide, particularly in China and India. Compared with Caucasians, Asian people with diabetes have lower body mass index, increased visceral adiposity, and postprandial glucose (PPG)/insulin resistance. Since postprandial hyperglycemia contributes significantly to total glycemic burden and is associated with heightened cardiovascular risk, targeting PPG early in T2D is paramount. Premixed insulin regimens are widely used in Asia due to their convenience and effectiveness. Data from randomized controlled trials and observational studies comparing efficacy and safety of biphasic insulin aspart 30 (BIAsp 30) with biphasic insulin lispro mix (LM 25/50) and versus other insulin therapies or oral antidiabetic drugs (OADs) in T2D demonstrated that BIAsp 30 and LM 25/50 were associated with similar or greater improvements in glycemic control versus comparator regimens, such as basal–bolus insulin, in insulin-naÏve, and prior insulin users. Studies directly comparing BIAsp 30 and LM 25 provided conflicting glycemic control results. Safety data generally showed increased hypoglycemia and weight gain with premixed insulins versus basal–bolus insulin or OADs. However, large observational trials documented improvements in glycated hemoglobin, PPG, and hypoglycemia with BIAsp 30 in multi-ethnic patient populations. In summary, this literature review demonstrates that premixed insulin regimens are an appropriate and effective treatment choice in T2D. PMID:27186543

  20. Formation of a Fluorous/Organic Biphasic Supramolecular Octopus Assembly for Enhanced Porphyrin Phosphorescence in Air

    DOE PAGES

    Yang, Chi; Arvapally, Ravi K.; Tekarli, Sammer M.; ...

    2015-03-03

    The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal- interactions affords the supramolecular assemblies [1PtOEP] or [1H(2)OEP] (2a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes.

  1. Origin and correction of magnetic field inhomogeneity at the interface in biphasic NMR samples.

    PubMed

    Martin, Bryan T; Chingas, G C; McDougal, Owen M

    2012-05-01

    The use of susceptibility matching to minimize spectral distortion of biphasic samples layered in a standard 5 mm NMR tube is described. The approach uses magic angle spinning (MAS) to first extract chemical shift differences by suppressing bulk magnetization. Then, using biphasic coaxial samples, magnetic susceptibilities are matched by titration with a paramagnetic salt. The matched phases are then layered in a standard NMR tube where they can be shimmed and examined. Linewidths of two distinct spectral lines, selected to characterize homogeneity in each phase, are simultaneously optimized. Two-dimensional distortion-free, slice-resolved spectra of an octanol/water system illustrate the method. These data are obtained using a 2D stepped-gradient pulse sequence devised for this application. Advantages of this sequence over slice-selective methods are that acquisition efficiency is increased and processing requires only conventional software.

  2. A biphasic hyperelastic model for the analysis of fluid and mass transport in brain tissue.

    PubMed

    García, José Jaime; Smith, Joshua H

    2009-02-01

    A biphasic hyperelastic finite element model is proposed for the description of the mechanical behavior of brain tissue. The model takes into account finite deformations through an Ogden-type hyperelastic compressible function and a hydraulic conductivity dependent on deformation. The biphasic equations, implemented here for spherical symmetry using an updated Lagrangian algorithm, yielded radial coordinates and fluid velocities that were used with the convective-diffusive equation in order to predict mass transport in the brain. Results of the model were equal to those of a closed-form solution under infinitesimal deformations, however, for a wide range of material parameters, the model predicted important increments in the infusion sphere, reductions of the fluid velocities, and changes in the species content distribution. In addition, high localized deformation and stresses were obtained at the infusion sphere. Differences with the infinitesimal solution may be mainly attributed to geometrical nonlinearities related to the increment of the infusion sphere and not to material nonlinearities.

  3. Biphasic Kinetic Behavior of Nitrate Reductase from Heterocystous, Nitrogen-Fixing Cyanobacteria 1

    PubMed Central

    Martin-Nieto, José; Flores, Enrique; Herrero, Antonia

    1992-01-01

    Nitrate reductase activity from filamentous, heterocyst-forming cyanobacteria showed a biphasic kinetic behavior with respect to nitrate as the variable substrate. Two kinetic components were detected, the first showing a higher affinity for nitrate (Km, 0.05-0.25 mm) and a lower catalytic activity and the second showing a lower affinity for nitrate (Km, 5-25 mm) and a higher (3- to 5-fold) catalytic activity. In contrast, among unicellular cyanobacteria, most representatives studied exhibited a monophasic, Michaelis-Menten kinetic pattern for nitrate reductase activity. Biphasic kinetics remained unchanged with the use of different assay conditions (i.e. cell disruption or permeabilization, two different electron donors) or throughout partial purification of the enzyme. PMID:16652939

  4. Microstructure Evolution of Biphasic TiNi1+ x Sn Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Verma, Nisha; Douglas, Jason E.; Krämer, Stephan; Pollock, Tresa M.; Seshadri, Ram; Levi, Carlos G.

    2016-08-01

    The effects of thermal treatment on the microstructure of biphasic materials comprising half-Heusler (hH) and full-Heusler (fH) phases, as well as on their associated thermal conductivity, are discussed. The focus of this study was on a biphasic hH/fH alloy of nominal stoichiometry TiNi1.2Sn, synthesized by containerless (magnetic levitation) induction melting. The alloy samples were exposed to various heat treatments to generate microstructures containing second-phase precipitates ranging in size from ~10 nm to a few micrometers. The materials were characterized with regard to morphology, size, shape, and orientation relationship of the fH and hH phases, both of which were present as precipitates within larger regions of the counterpart phase. The solidification path of the alloy and its implications for the subsequent microstructure evolution during heat treatment were elucidated, and relationships with the ensuing thermal conductivity were characterized.

  5. Tracking performance of unbalanced QPSK demodulators. II - Biphase Costas loop with active arm filters

    NASA Technical Reports Server (NTRS)

    Simon, M. K.

    1978-01-01

    In a Costas loop study for biphase modulation conducted by Simon and Lindsey (1977), it was demonstrated that considerable improvement in tracking performance could be obtained by employing active arm filters of the integrate-and-dump type as opposed to passive arm filters. An investigation is conducted concerning the possibility to obtain a similar performance improvement for an unbalanced quadriphase-shift-keying (QPSK) modulation. It is found that the biphase Costas loop can be used as an efficient demodulator of QPSK in cases in which the ratio of data rates is of the same order of magnitude as the inverse of the power ratio. These cases involve approximately equal signal energies in the two channels.

  6. A biphasic mercury-ion sensor: exploiting microfluidics to make simple anilines competitive ligands.

    PubMed

    Petzoldt, Martin; Eschenbaum, Carsten; Schwaebel, S Thimon; Broedner, Kerstin; Lemmer, Uli; Hamburger, Manuel; Bunz, Uwe H F

    2015-10-05

    Combining the molecular wire effect with a biphasic sensing approach (analyte in water, sensor-dye in 2-methyltetrahydrofuran) and a microfluidic flow setup leads to the construction of a mercury-sensitive module. We so instantaneously detect Hg(2+) ions in water at a 500 μM concentration. The sensor, conjugated non-water soluble polymer 1 (XFPF), merely supports dibutylaniline substituents as binding units. Yet, selective and sensitive detection of Hg(2+) -ions is achieved in water. The enhancement in sensory response, when comparing the reference compound 2 to that of 1 in a biphasic system in a microfluidic chip is >10(3) . By manipulation of the structure of 1, further powerful sensor systems should be easily achieved.

  7. A biphasic parameter estimation method for quantitative analysis of dynamic renal scintigraphic data

    NASA Astrophysics Data System (ADS)

    Koh, T. S.; Zhang, Jeff L.; Ong, C. K.; Shuter, B.

    2006-06-01

    Dynamic renal scintigraphy is an established method in nuclear medicine, commonly used for the assessment of renal function. In this paper, a biphasic model fitting method is proposed for simultaneous estimation of both vascular and parenchymal parameters from renal scintigraphic data. These parameters include the renal plasma flow, vascular and parenchymal mean transit times, and the glomerular extraction rate. Monte Carlo simulation was used to evaluate the stability and confidence of the parameter estimates obtained by the proposed biphasic method, before applying the method on actual patient study cases to compare with the conventional fitting approach and other established renal indices. The various parameter estimates obtained using the proposed method were found to be consistent with the respective pathologies of the study cases. The renal plasma flow and extraction rate estimated by the proposed method were in good agreement with those previously obtained using dynamic computed tomography and magnetic resonance imaging.

  8. Biphasic and boundary lubrication mechanisms in artificial hydrogel cartilage: A review.

    PubMed

    Murakami, Teruo; Yarimitsu, Seido; Nakashima, Kazuhiro; Sakai, Nobuo; Yamaguchi, Tetsuo; Sawae, Yoshinori; Suzuki, Atsushi

    2015-12-01

    Various studies on the application of artificial hydrogel cartilage to cartilage substitutes and artificial joints have been conducted. It is expected in clinical application of artificial hydrogel cartilage that not only soft-elastohydrodynamic lubrication but biphasic, hydration, gel-film and boundary lubrication mechanisms will be effective to sustain extremely low friction and minimal wear in daily activities similar to healthy natural synovial joints with adaptive multimode lubrication. In this review article, the effectiveness of biphasic lubrication and boundary lubrication in hydrogels in thin film condition is focused in relation to the structures and properties of hydrogels. As examples, the tribological behaviors in three kinds of poly(vinyl alcohol) hydrogels with high water content are compared, and the importance of lubrication mechanism in biomimetic artificial hydrogel cartilage is discussed to extend the durability of cartilage substitute.

  9. Mesenchymal stem cells combined with biphasic calcium phosphate ceramics promote bone regeneration.

    PubMed

    Livingston, T L; Gordon, S; Archambault, M; Kadiyala, S; McIntosh, K; Smith, A; Peter, S J

    2003-03-01

    The reconstruction and repair of large bone defects, resulting from trauma, cancer or metabolic disorders, is a major clinical challenge in orthopaedics. Clinically available biological and synthetic grafts have clear limitations that necessitate the development of new graft materials and/or strategies. Human mesenchymal stem cells (MSCs), obtained from the adult bone marrow, are multipotent cells capable of differentiating into various mesenchymal tissues. Of particular interest is the ability of these cells to differentiate into osteoblasts, or bone-forming cells. At Osiris, we have extensively characterized MSCs and have demonstrated MSCs can induce bone repair when implanted in vivo in combination with a biphasic calcium phosphate, specifically hydroxyapatite/tricalcium phosphate. This article reviews previous and current studies utilizing mesenchymal stem cells and biphasic calcium phosphates in bone repair.

  10. [Extracapsular lobectomy in benign monolobar thyroid diseases].

    PubMed

    Prete, F; Di Ciaula, G; Sammarco, D; Parlati, C

    1995-12-01

    On the basis of their experience acquired in the field of thyroid surgery the authors examine the problems related to extracapsular lobectomy from a tactical and technical point of view, starting with its principal indications: benign monolobar thyroid disease in a single or multiple nodular form. The validity of extemporary histological tests is also assessed on the basis of their experience of rare false negatives and the relative successive totalization programme. Lastly, the paper underlines the fundamental identification of the recurrent nerve as the central point of the operation, before which the authors emphasize that nothing should be cut or ligated apart from the superior vascular peduncle and vena media.

  11. [Anterior semicircular canal Benign Paroxysmal Positional Vertigo].

    PubMed

    Alzuphar, Stephen Jacques; Maire, Raphaël

    2016-10-05

    Anterior semicircular canal Benign Paroxysmal Positional Vertigo (antBPPV) is the rarest form of semicircular canalolithiasis, corresponding to about 1-2 % of the BPPV. The diagnosis is obtained by either the Dix-Hallpike maneuver or the straight head hanging positioning maneuver, which provoke a characteristic positional down-beating nystagmus. This vertical nystagmus can be associated with a torsional component that helps in localizing the affected side. The differential diagnosis of antBPPV includes the various central lesions that produce vertical down beating nystagmus (posterior fossa). Several liberatory maneuvers have been proposed for the treatment of antBPPV, but still need standardization.

  12. Spatial contrast sensitivity in benign intracranial hypertension.

    PubMed

    Bulens, C; Meerwaldt, J D; Koudstaal, P J; Van der Wildt, G J

    1988-10-01

    Spatial Contrast Sensitivity (CS) was studied in 20 patients with benign intracranial hypertension (BIH). At presentation CS loss was found in 43% of the eyes, and impairment of visual acuity attributed to BIH in only 16%. Nine patients had blurred vision or visual obscurations, all of whom had abnormal CS. The clinical application of CS measurement in BIH for monitoring the progression or regression of the disease is illustrated by serial measurements in 11 patients. Progressive visual loss in longstanding papilloedema and improvement of visual function in subsiding papilloedema can occur without any change in Snellen acuity or visual field charting.

  13. Thallium-201 uptake in a benign thymoma

    SciTech Connect

    Campeau, R.J.; Ey, E.H.; Varma, D.G.

    1986-07-01

    A 68-year-old woman was admitted with atypical angina. A chest radiograph showed an anterior mediastinal mass that was confirmed on CT. The mass was relatively avascular and separate from the heart and great vessels. She underwent stress thallium testing that demonstrated no exercise-induced ischemia; however, an abnormal focus of thallium activity was present in the anterior mediastinum on stress and redistribution images. Cardiac catheterization demonstrated a normal left ventriculogram, coronary arteries and thoracic aorta. Subsequent surgery and pathologic examination revealed the mass to be a benign thymoma arising in the right lobe of the thymus gland.

  14. Spatial contrast sensitivity in benign intracranial hypertension.

    PubMed Central

    Bulens, C; Meerwaldt, J D; Koudstaal, P J; Van der Wildt, G J

    1988-01-01

    Spatial Contrast Sensitivity (CS) was studied in 20 patients with benign intracranial hypertension (BIH). At presentation CS loss was found in 43% of the eyes, and impairment of visual acuity attributed to BIH in only 16%. Nine patients had blurred vision or visual obscurations, all of whom had abnormal CS. The clinical application of CS measurement in BIH for monitoring the progression or regression of the disease is illustrated by serial measurements in 11 patients. Progressive visual loss in longstanding papilloedema and improvement of visual function in subsiding papilloedema can occur without any change in Snellen acuity or visual field charting. PMID:3225588

  15. Benign paroxysmal positional vertigo: diagnosis and treatment.

    PubMed

    Bittar, Roseli Saraiva Moreira; Mezzalira, Raquel Mezzalira; Furtado, Paula Lobo; Venosa, Alessandra Ramos; Sampaio, Andre Luis Lopes; Pires de Oliveira, Carlos Augusto Costa

    2011-01-01

    Benign paroxysmal positional vertigo is a common disorder in Neurotology. This vestibular syndrome is characterized by transient attacks of vertigo, caused by change in head position, and associated with paroxysmal characteristic nystagmus. The symptoms result from movement of the free floating otoconia particles in the endolymph or their attachment to the cupulae of the semicircular canal. The diagnosis is essentially clinical and should be confirmed by performing diagnostic maneuvers. Treatment is based on the identification of the affected semicircular canal and performance of liberatory maneuvers or repositioning of free floating particles of otoliths. The effectiveness varies from 70 to 100%.

  16. [Benign reflex myoclonic epilepsy in infants].

    PubMed

    Cuvellier, J C; Lamblin, M D; Cuisset, J M; Vallée, L; Nuyts, J P

    1997-08-01

    Myoclonic epilepsy of infancy are seldom benign. A 25-month old girl developed myoclonic jerks either spontaneously either as reflex responses to auditory and tactile stimuli, such as sudden touching of the face or trunk from the age of 4 months. The jerks disappeared after valproate therapy. Neurological examination was normal with a follow-up of 9 months. This condition resembles that described in 1995 by Ricci et al. In must be differentiated from other myoclonic epilepsies of infancy, reflex epilepsies and hyperekplexia. It could be the earliest from of idiopathic generalized epilepsy.

  17. Benign familial Degos disease worsening during immunosuppression.

    PubMed

    Powell, J; Bordea, C; Wojnarowska, F; Farrell, A M; Morris, P J

    1999-09-01

    We describe a 61-year-old woman with skin lesions consistent with those found in Degos disease, both in clinical and in histological appearance. She had had several of these lesions for many years, as had her mother, sister and niece. In 1991, she underwent cadaveric renal transplantation and was treated with immunosuppression: prednisolone, azathioprine and cyclosporin. At that time, she developed many more characteristic skin lesions, and these were slightly larger and more noticeable than those she had had previously. She and the other affected family members appear to fit into the more benign subgroup of Degos disease, and it seems that her immunosuppression aggravated her cutaneous disease.

  18. Developmental and benign movement disorders in childhood.

    PubMed

    Bonnet, Cecilia; Roubertie, Agathe; Doummar, Diane; Bahi-Buisson, Nadia; Cochen de Cock, Valérie; Roze, Emmanuel

    2010-07-30

    Developmental and benign movement disorders are a group of movement disorders with onset in the neonatal period, infancy, or childhood. They are characterized by the absence of associated neurological manifestations and by their favorable outcome, although developmental abnormalities can be occasionally observed. Knowledge of the clinical, neurophysiological, and pathogenetic aspects of these disorders is poor. Based on a comprehensive review of the literature and our practical experience, this article summarizes current knowledge in this area. We pay special attention to the recognition and management of these movement disorders in children. (c) 2010 Movement Disorder Society.

  19. Rheology of nanocrystalline cellulose aqueous suspensions.

    PubMed

    Shafiei-Sabet, Sadaf; Hamad, Wadood Y; Hatzikiriakos, Savvas G

    2012-12-11

    The rheological properties and microstructure of nanocrystalline cellulose (NCC) aqueous suspensions have been investigated at different concentrations. The suspension is isotropic up to 3 wt %, and phase separates to liquid crystalline and isotropic domains at higher concentrations where the samples exhibit a fingerprint texture and the viscosity profile shows a three-region behavior, typical of liquid crystals. The suspension behaves as a rheological gel at even higher concentrations where the viscosity profile shows a single shear thinning behavior over the whole range of shear rates investigated. The effects of ultrasound energy and temperature on the rheological properties and structure of these suspensions were studied using polarized optical microscopy and rheometry. Our results indicate that the amount of applied ultrasound energy affects the microstructure of the suspensions and the pitch of the chiral nematic domains. The viscosity profile is changed significantly at low shear rates, whereas the viscosity of biphasic suspensions at intermediate and high shear rates decreased with increasing temperature. This suggests that, between 30 and 40 °C, structural rearrangement takes place. At higher concentrations of about 10 wt %, the temperature has no significant effect on viscosity; however, a marked increase in viscosity has been observed at around 50 °C. Finally, the Cox-Merz rule was found to fail after a critical concentration, thereby implying significant structural formation. This critical concentration is much higher for sonicated compared to unsonicated suspensions.

  20. Deriving sulfamethoxazole dissipation endpoints in pasture soils using first order and biphasic kinetic models.

    PubMed

    Srinivasan, Prakash; Sarmah, Ajit K; Rohan, Maheswaran

    2014-08-01

    Single first-order (SFO) kinetic model is often used to derive the dissipation endpoints of an organic chemical in soil. This model is used due to its simplicity and requirement by regulatory agencies. However, using the SFO model for all types of decay pattern could lead to under- or overestimation of dissipation endpoints when the deviation from first-order is significant. In this study the performance of three biphasic kinetic models - bi-exponential decay (BEXP), first-order double exponential decay (FODED), and first-order two-compartment (FOTC) models was evaluated using dissipation datasets of sulfamethoxazole (SMO) antibiotic in three different soils under varying concentration, depth, temperature, and sterile conditions. Corresponding 50% (DT50) and 90% (DT90) dissipation times for the antibiotics were numerically obtained and compared against those obtained using the SFO model. The fit of each model to the measured values was evaluated based on an array of statistical measures such as coefficient of determination (R(2)adj), root mean square error (RMSE), chi-square (χ(2)) test at 1% significance, Bayesian Information Criteria (BIC) and % model error. Box-whisker residual plots were also used to compare the performance of each model to the measured datasets. The antibiotic dissipation was successfully predicted by all four models. However, the nonlinear biphasic models improved the goodness-of-fit parameters for all datasets. Deviations from datasets were also often less evident with the biphasic models. The fits of FOTC and FODED models for SMO dissipation datasets were identical in most cases, and were found to be superior to the BEXP model. Among the biphasic models, the FOTC model was found to be the most suitable for obtaining the endpoints and could provide a mechanistic explanation for SMO dissipation in the soils.

  1. [The design of the external defibrillator using the truncated exponential biphasic waveform].

    PubMed

    Song, Er-mei; Wu, Xiao-mei; Yang, Cui-wei; Fang, Zu-xiang

    2006-01-01

    The external defibrillator is an emergency instrument used very widely in clinics. It plays an important role in rescuing ventricle fibrillation (VF) patients. We have designed an external defibrillator using the truncated exponential biphasic waveform. The system consists of three parts: the ECG collection module, the control module and the defibrillator module. They are introduced respectively, listing the main problems and the methods to solve them. Some experiments have been done and the corresponding results are given.

  2. Electronic and structural characteristics of zinc-blende wurtzite biphasic homostructure GaN nanowires

    DOE PAGES

    Jacobs, Benjamin W.; Ayres, Virginia M.; Petkov, Mihail P.; ...

    2007-04-07

    Here, we report a new biphasic crystalline wurtzite/zinc-blende homostructure in gallium nitride nanowires. Cathodoluminescence was used to quantitatively measure the wurtzite and zinc-blende band gaps. High-resolution transmission electron microscopy was used to identify distinct wurtzite and zinc-blende crystalline phases within single nanowires through the use of selected area electron diffraction, electron dispersive spectroscopy, electron energy loss spectroscopy, and fast Fourier transform techniques. A mechanism for growth is identified.

  3. Volume-controlled versus biphasic positive airway pressure ventilation in leukopenic patients with severe respiratory failure.

    PubMed

    Kiehl, M; Schiele, C; Stenzinger, W; Kienast, J

    1996-05-01

    To study comparatively the effects of volume-controlled vs. biphasic positive airway pressure mechanical ventilation on respiratory mechanics and oxygenation in leukopenic patients with severe respiratory failure. Prospective, comparative study. Medical intensive care unit of a university hospital. Leukopenic (<1000 leukocytes/microliter) patients (n=20) after cytoreductive chemotherapy requiring mechanical ventilation for severe respiratory failure (Murray score of > 2.5). Patients were assigned in a consecutive, alternating manner to receive either volume-controlled or biphasic positive airway pressure mechanical ventilation, starting within 12 to 24 hrs after endotracheal intubation. Tidal volume, inspiratory flow, peak inspiratory and positive end-expiratory pressures, FIO2, and arterial blood gas analyses were recorded hourly for a study period of 48 hrs. Biphasic positive airway pressure ventilation was associated with a significant reduction in peak inspiratory pressure (mean differences at 24, 36, and 48 hrs: 4.4, 3.4, and 4.2 cm H2O; p = .024, .019, and .013, respectively) and positive end-expiratory pressures (mean differences at 24, 36, and 48 hrs: 1.6, 1.4, and 1.5 cm H20; p = .023, .024, and .023, respectively) at significantly lower FIO2 (mean differences at 12, 24, 36, and 48 hrs; p = .007, .015, .016, and .011, respectively). PaO2/FIO2 ratios and CO2 removal were similar under ventilatory conditions. Biphasic positive airway pressure ventilation offers the advantage of significantly reduced peak inspiratory and positive end-expiratory pressures at a lower FIO2 and with at least similar oxygenation and CO2 removal as achieved by volume-controlled mechanical ventilation. Our results are in line with previous reports on nonleukopenic patients and suggest that the positive effects of pressure-limited mechanical ventilation are independent of circulating white blood cells. Further studies are mandatory to demonstrate clinical benefit in this critically

  4. A case of protracted hypotension as unique symptom of a biphasic anaphylaxis to amoxicillin.

    PubMed

    Zisa, G; Riccobono, F; Calamari, A M; D'Antonio, C D; Galimberti, M

    2009-04-01

    We are reporting a case of one patient who have experienced itching of palms and soles, thorax erythema, conjunctive injection immediately after oral administration of amoxicillin, and hypotension after 3 hours. In E.D. hypotension was monitored because he was a cardiopatic but it wasn't treated even if it was protracted. A positive result of immediate-reading intradermal test with amoxicillin at 2 mg/ml concentration was found confirming the diagnosis of allergic biphasic anaphylaxis to amoxicillin.

  5. A numerical method for biphasic curve fitting with a programmable calculator.

    PubMed

    Ristanović, D; Ristanović, D; Malesević, J; Milutinović, B

    1982-01-01

    Elimination kinetics of bromsulphalein (BSP) after a single injection into the circulation of rats were examined by means of a four-compartment model. BSP plasma concentrations were measured colorimetrically. A program written for the Texas Instruments TI-59 programmable calculator is presented, which will calculate the fractional blood clearance of BSP using an iteration procedure. A simple method of fitting biphasic decay curves to experimental data is also proposed.

  6. Nitric oxide interacts with salicylate to regulate biphasic ethylene production during the hypersensitive response.

    PubMed

    Mur, Luis A J; Laarhoven, Lucas J J; Harren, Frans J M; Hall, Michael A; Smith, Aileen R

    2008-11-01

    C(2)H(4) is associated with plant defense, but its role during the hypersensitive response (HR) remains largely uncharacterized. C(2)H(4) production in tobacco (Nicotiana tabacum) following inoculation with HR-eliciting Pseudomonas syringae pathovars measured by laser photoacoustic detection was biphasic. A first transient rise (C(2)H(4)-I) occurred 1 to 4 h following inoculation with HR-eliciting, disease-forming, and nonpathogenic strains and also with flagellin (flg22). A second (avirulence-dependent) rise, at approximately 6 h (C(2)H(4)-II), was only seen with HR-eliciting strains. Tobacco leaves treated with the C(2)H(4) biosynthesis inhibitor, aminoethoxyvinylglycine, suggested that C(2)H(4) influenced the kinetics of a HR. Challenging salicylate hydroxylase-expressing tobacco lines and tissues exhibiting systemic acquired resistance suggested that C(2)H(4) production was influenced by salicylic acid (SA). Disrupted expression of a C(2)H(4) biosynthesis gene in salicylate hydroxylase tobacco plants implicated transcriptional control as a mechanism through which SA regulates C(2)H(4) production. Treating leaves to increase oxidative stress or injecting with SA initiated monophasic C(2)H(4) generation, but the nitric oxide (NO) donor sodium nitroprusside initiated biphasic rises. To test whether NO influenced biphasic C(2)H(4) production during the HR, the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester was coinoculated with the avirulent strain of P. syringae pv phaseolicola into tobacco leaves. The first transient C(2)H(4) rise appeared to be unaffected by N(G)-nitro-L-arginine methyl ester, but the second rise was reduced. These data suggest that NO and SA are required to generate the biphasic pattern of C(2)H(4) production during the HR and may influence the kinetics of HR formation.

  7. A Phenomenological Model of the Electrically Stimulated Auditory Nerve Fiber: Temporal and Biphasic Response Properties

    PubMed Central

    Horne, Colin D. F.; Sumner, Christian J.; Seeber, Bernhard U.

    2016-01-01

    We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs). The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability) under both monophasic and cathodic-anodic biphasic stimulation, without changing the model's parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG) of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions. Our work extends the stochastic leaky integrate and fire (SLIF) neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model. PMID:26903850

  8. A case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion.

    PubMed

    Hazama, Kyoko; Shiihara, Takashi; Tsukagoshi, Hiroyuki; Hasegawa, Shunji; Dowa, Yuri; Watanabe, Mio

    2017-10-01

    Mumps is a common childhood viral disease characterized by fever and swelling of the parotid gland. The prognosis is generally good, although some complications, such as encephalitis (0.1%), exist. Acute encephalopathy with biphasic seizures and late reduced diffusion is the most common type of acute encephalopathy. However, this type of encephalopathy has not been reported in association with mumps infection. A previously healthy 3-year-old Japanese boy had a brief convulsion after fever for 3days, and then had conscious disturbance and parotitis. After several days, he had a second brief convulsion and was admitted. Increased serum amylase levels and presence of anti-mumps immunoglobulin M antibody confirmed mumps parotitis. The patient had another brief seizure later the day of admission. He did not have status or cluster seizures, although the biphasic nature of his seizures, conscious disturbance between the seizures, no pleocytosis in cerebrospinal fluid, and brain magnetic resonance images were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion. In Japan, the mumps vaccine is not administered as a part of routine immunizations. It thus has low coverage (30-40%), and as a result, mumps infections are still common. However, this is the first case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion. This case may be representative of only a minority of patients with mumps-associated central nervous system involvement. Nevertheless, this diagnostic possibility may be considered. In order to prevent mumps-related complications, routine mumps vaccination might be warranted. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  9. Production of Furfural from Process-Relevant Biomass-Derived Pentoses in a Biphasic Reaction System

    DOE PAGES

    Mittal, Ashutosh; Black, Stuart K.; Vinzant, Todd B.; ...

    2017-05-16

    Furfural is an important fuel precursor which can be converted to hydrocarbon fuels and fuel intermediates. In this work, the production of furfural by dehydration of process-relevant pentose rich corn stover hydrolyzate using a biphasic batch reaction system has been investigated. Methyl isobutyl ketone (MIBK) and toluene have been used to extract furfural and enhance overall furfural yield by limiting its degradation to humins. The effects of reaction time, temperature, and acid concentration (H2SO4) on pentose conversion and furfural yield were investigated. For the dehydration of 8 wt % pentose-rich corn stover hydrolyzate under optimum reaction conditions, 0.05 M H2SO4,more » 170 degrees C for 20 min with MIBK as the solvent, complete conversion of xylose (98-100%) and a furfural yield of 80% were obtained. Under these same conditions, except with toluene as the solvent, the furfural yield was 77%. Additionally, dehydration of process-relevant pentose rich corn stover hydrolyzate using solid acid ion-exchange resins under optimum reaction conditions has shown that Purolite CT275 is as effective as H2SO4 for obtaining furfural yields approaching 80% using a biphasic batch reaction system. In conclusion, this work has demonstrated that a biphasic reaction system can be used to process biomass-derived pentose rich sugar hydrolyzates to furfural in yields approaching 80%.« less

  10. Clinical efficacy of a wearable defibrillator in acutely terminating episodes of ventricular fibrillation using biphasic shocks.

    PubMed

    Reek, Sven; Geller, J Christoph; Meltendorf, Ulf; Wollbrueck, Anke; Szymkiewicz, Steven J; Klein, Helmut U

    2003-10-01

    The Wearable Cardioverter Defibrillator (WCD) automatically detects and treats ventricular tachyarrhythmias without the need for assistance from a bystander, while at the same time allowing the patient to ambulate freely. It represents an alternative to emergency medical services for outpatient populations with a temporary risk of sudden cardiac death. While the original devices used a monophasic truncated exponential waveform for cardioversion/defibrillation shocks, a new, biphasic shock was developed for the next device generation. In 12 patients undergoing electrophysiological testing for ventricular tachyarrhythmias, termination of electrically induced ventricular fibrillation (VF) was attempted via the WCD. In 22 episodes, induced VF was promptly terminated by the first 70 J (n=12) or 100 J (n=10) biphasic shocks. Time between arrhythmia initiation and shock delivery was 22 +/- 6 seconds (70 J) and 21 +/- 6 seconds (100 J) (P=NS). The measured transthoracic impedance was 71 +/- 5 Ohms (64-79 Ohms) for the 70 J shock and 64 +/- 8 Ohms (47-72 Ohms) for the 100 J shock. The present study demonstrates that a single low energy biphasic shock delivered by the WCD, reliably terminates electrically induced VF (100% of episodes). The results of this study suggest that there is an acceptable safety margin to the maximum output of the device (150 J). Despite our promising data, we recommend that programming all shocks for maximum energy output should be done when using the WCD in ambulatory patients.

  11. Biphasic transient kinetics are a property of a single site in horse liver alcohol dehydrogenase.

    PubMed

    Anderson, D C; Dahlquist, F W

    1982-07-20

    The transient kinetics under single turnover conditions of the dimeric enzyme horse liver alcohol dehydrogenase (LADH) are often biphasic with nearly equal amplitudes in the fast and slow components of the reaction. These observations have been the basis for the suggestion that this enzyme displays half of the sites reactivity or kinetic site-site interactions in its catalytic cycle [Bernhard, S.A., Dunn, M.F., Luisi, P.L., & Shack, P. (1970) Biochemistry 9, 185]. Alternatively, the biphasic kinetics could be the result of a complex mechanistic path at a single site with no kinetic interactions between the active sites [Kvassman, J., & Pettersson, G. (1976) Eur. J. Biochem. 62, 279; Kvassman, J., & Pettersson, G. (1978) Eur. J. Biochem. 87, 417]. To resolve this question, we have prepared LADH in which one of the two active sites is occupied by the strongly bound, slowly exchanging ternary complex inhibitors NAD with trifluoroethanol or NAD with pyrazole. These half-inhibited dimers show essentially the same biphasic transient kinetics as the native enzyme. These results strongly support mechanisms in which the observed kinetics are a property of each independently functioning site of the dimer. The possibility of half of the sites reactivity or kinetic site-site interaction appears to be ruled out.

  12. Simulation by two calcium store models of myocardial dynamic properties: potentiation, staircase, and biphasic tension development.

    PubMed

    Wussling, M; Szymanski, G

    1986-04-01

    Most considerations and models concerning myocardial dynamic properties e.g. potentiation and staircase, are based upon the existence of storage structures in the heart muscle cell. The phenomenon of biphasic tension development (or two-component contraction) in heart muscle preparations of several mammalian species suggests that the sarcoplasmic reticulum is one, but by no means the major, source of activator calcium for the contractile system. The simulation of dynamic properties including biphasic tension development was performed in two steps by a simple "two-Ca store-model" and by an "expanded two-Ca store-model" with following results: Increasing potentiation indicated a decrease in the degree of coupling between the Ca stores. A shift of the interval strength curve to lower intervals as well as a decrease of the steady state contraction height implies a decrease of both, the coupling and the leakage time constant. There was no standard relation between staircase phenomena and structure parameters. Analog displays showed a late (or second) component at prolongated stimulation intervals, in the transient phase after a rest period, in the case of perfectly coupled or uncoupled stores, and at great time constant tau p (which characterizes the calcium pump activity). It is concluded that the late component of biphasic tension development is due to direct activation by the transsarcolemmal Ca flux of the myofilaments, whereas the early component is caused by the release of stored calcium. In the absence of an early component neither potentiation nor marked treppe may be expected.

  13. (*) Fabrication and Characterization of Biphasic Silk Fibroin Scaffolds for Tendon/Ligament-to-Bone Tissue Engineering.

    PubMed

    Font Tellado, Sònia; Bonani, Walter; Balmayor, Elizabeth R; Foehr, Peter; Motta, Antonella; Migliaresi, Claudio; van Griensven, Martijn

    2017-08-01

    Tissue engineering is an attractive strategy for tendon/ligament-to-bone interface repair. The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons/ligaments and bone. Thus, scaffolds mimicking the structural features of the native interface may be able to better support functional tissue regeneration. In this study, we fabricated biphasic silk fibroin scaffolds designed to mimic the gradient in collagen molecule alignment present at the interface. The scaffolds had two different pore alignments: anisotropic at the tendon/ligament side and isotropic at the bone side. Total porosity ranged from 50% to 80% and the majority of pores (80-90%) were <100-300 μm. Young's modulus varied from 689 to 1322 kPa depending on the type of construct. In addition, human adipose-derived mesenchymal stem cells were cultured on the scaffolds to evaluate the effect of pore morphology on cell proliferation and gene expression. Biphasic scaffolds supported cell attachment and influenced cytoskeleton organization depending on pore alignment. In addition, the gene expression of tendon/ligament, enthesis, and cartilage markers significantly changed depending on pore alignment in each region of the scaffolds. In conclusion, the biphasic scaffolds fabricated in this study show promising features for tendon/ligament-to-bone tissue engineering.

  14. A comparison of lipase-catalyzed ester hydrolysis in reverse micelles, organic solvents, and biphase systems

    SciTech Connect

    Yang, F.; Russell, A.J.

    1995-07-05

    The performance of lipases from Candida rugosa and wheat germ have been investigated in three reaction media using three acetate hydrolyses as model reactions (ethyl acetate, allyl acetate, and prenyl acetate). The effect of substrate properties and water content were studied for each system (organic solvent, biphasic system, and reverse micelles). Not unexpectedly, the effect of water content is distinct for each system, and the optimal water content for enzyme activity is not always the same as that for productivity. A theoretical model has been used to simulate and predict enzyme performance in reverse micelles, and a proposed partitioning model for biphasic systems agrees well with experimental results. While the highest activities observed were in the micellar system, productivity in microemulsions is limited by low enzyme concentrations. Biphasic systems, however, support relatively good activity and productivity. The addition of water to dry organic solvents, combined with the dispersion of lyophilized enzyme powders in the solvent, resulted in significant enzyme aggregation, which not surprisingly limits the applicability of the ``anhydrous`` enzyme suspension approach.

  15. Engineered osteochondral grafts using biphasic composite solid free-form fabricated scaffolds.

    PubMed

    Schek, Rachel M; Taboas, Juan M; Segvich, Sharon J; Hollister, Scott J; Krebsbach, Paul H

    2004-01-01

    Tissue engineering has provided an alternative to traditional strategies to repair cartilage damaged by injury or degenerative disease. A successful strategy to engineer osteochondral tissue will mimic the natural contour of the articulating surface, achieve native mechanical properties and functional load-bearing ability, and lead to integration with host cartilage and underlying subchondral bone. Image-based design (IBD) and solid free-form (SFF) fabrication can be used to generate scaffolds that are load bearing and match articular geometry. The objective of this study was to utilize materials and biological factors in an integrated approach to regenerate a multitissue interface. Biphasic composite scaffolds manufactured by IBD and SFF fabrication were used to simultaneously generate bone and cartilage in discrete regions and provide for the development of a stable interface between cartilage and subchondral bone. Poly-L-lactic acid/hydroxyapatite composite scaffolds were differentially seeded with fibroblasts transduced with an adenovirus expressing bone morphogenetic protein 7 (BMP-7) in the ceramic phase and fully differentiated chondrocytes in the polymeric phase. After subcutaneous implantation into mice, the biphasic scaffolds promoted the simultaneous growth of bone, cartilage, and a mineralized interface tissue. Within the ceramic phase, the pockets of tissue generated included blood vessels, marrow stroma, and adipose tissue. This combination of IBD and SFF-fabricated biphasic scaffolds with gene and cell therapy is a promising approach to regenerate osteochondral defects.

  16. Synchronized oscillations of dimers in biphasic charged fd-virus suspensions

    NASA Astrophysics Data System (ADS)

    Kang, K.; Piao, S. H.; Choi, H. J.

    2016-08-01

    Micron-sized colloidal spheres that are dispersed in an isotropic-nematic biphasic host suspension of charged rods (fd-virus particles) are shown to spontaneously form dimers, which exhibit a synchronized oscillatory motion. Dimer formation is not observed in the monophase of isotropic and nematic suspensions. The synchronized oscillations of dimers are connected to the inhomogeneous state of the host suspension of charged rods (fd viruses) where nematic domains are in coexistence with isotropic regions. The synchronization of oscillations occurs in bulk states, in the absence of an external field. With a low field strength of an applied electric field, the synchronization is rather reduced, but it recovers again when the field is turned off. In this Rapid Communication, we report this observation as an example of the strange attractor, occurring in the mixture of PS (polystyrene) dimers in an isotropic-nematic coexistence biphasic fd-virus network. Furthermore, we highlight that the synchronization of PS-dimer oscillations is the result of a global bifurcation diagram, driven by a delicate balance between the short-attractive "twisted" interaction of PS dimers and long-ranged electrostatic repulsive interactions of charged fd rods. The interest is then in the local enhancement of "twist-nematic" elasticity in reorientation of the dimer oscillations. An analysis of image-time correlations is provided with the data movies and Fourier transforms of averaged orientations for the synchronized oscillations of dimers in the biphasic I -N coexistence concentration of charged fd-virus suspensions.

  17. Modeling non-isothermal heat inactivation of microorganisms having biphasic isothermal survival curves.

    PubMed

    Corradini, Maria G; Normand, Mark D; Peleg, Micha

    2007-05-30

    Biphasic isothermal inactivation constitutes a special case of non-linear mortality kinetics. It can be modeled with a primary model that contains an 'If' statement and three temperature dependent survival parameters: the first and second logarithmic inactivation rate constants and the time of the transition from one phase to the other. The temperature dependence of the two inactivation rates of Salmonella enteritidis and that of the transition time determined from published data could be described by empirical logistic terms. These were used to construct an inactivation rate equation for non-isothermal heating and cooling regimes. The resulting differential equation, despite having an 'If' statement in its formulation, could be easily solved numerically for simple as well elaborate temperature profiles. The solutions for a variety of realistic heat treatment histories indicated that when the heating or cooling rate is high enough, the biphasic character of the inactivation disappears. This is true regardless of whether the rate at the first phase is higher than at the second, the most common scenario, or vice versa. Theoretically, the same will happen with inactivation caused by a non thermal agent whose intensity increases or diminishes, in biphasic growth under rapidly varying conditions and in enzymatic activity or inactivation.

  18. The effect of collagen fibril orientation on the biphasic mechanics of articular cartilage.

    PubMed

    Meng, Qingen; An, Shuqiang; Damion, Robin A; Jin, Zhongmin; Wilcox, Ruth; Fisher, John; Jones, Alison

    2017-01-01

    The highly inhomogeneous distribution of collagen fibrils may have important effects on the biphasic mechanics of articular cartilage. However, the effect of the inhomogeneity of collagen fibrils has mainly been investigated using simplified three-layered models, which may have underestimated the effect of collagen fibrils by neglecting their realistic orientation. The aim of this study was to investigate the effect of the realistic orientation of collagen fibrils on the biphasic mechanics of articular cartilage. Five biphasic material models, each of which included a different level of complexity of fibril reinforcement, were solved using two different finite element software packages (Abaqus and FEBio). Model 1 considered the realistic orientation of fibrils, which was derived from diffusion tensor magnetic resonance images. The simplified three-layered orientation was used for Model 2. Models 3-5 were three control models. The realistic collagen orientations obtained in this study were consistent with the literature. Results from the two finite element implementations were in agreement for each of the conditions modelled. The comparison between the control models confirmed some functions of collagen fibrils. The comparison between Models 1 and 2 showed that the widely-used three-layered inhomogeneous model can produce similar fluid load support to the model including the realistic fibril orientation; however, an accurate prediction of the other mechanical parameters requires the inclusion of the realistic orientation of collagen fibrils.

  19. Layered Double Hydroxide Nanoclusters: Aqueous, Concentrated, Stable, and Catalytically Active Colloids toward Green Chemistry.

    PubMed

    Tokudome, Yasuaki; Morimoto, Tsuyoshi; Tarutani, Naoki; Vaz, Pedro D; Nunes, Carla D; Prevot, Vanessa; Stenning, Gavin B G; Takahashi, Masahide

    2016-05-24

    Increasing attention has been dedicated to the development of nanomaterials rendering green and sustainable processes, which occur in benign aqueous reaction media. Herein, we demonstrate the synthesis of another family of green nanomaterials, layered double hydroxide (LDH) nanoclusters, which are concentrated (98.7 g/L in aqueous solvent), stably dispersed (transparent sol for >2 weeks), and catalytically active colloids of nano LDHs (isotropic shape with the size of 7.8 nm as determined by small-angle X-ray scattering). LDH nanoclusters are available as colloidal building blocks to give access to meso- and macroporous LDH materials. Proof-of-concept applications revealed that the LDH nanocluster works as a solid basic catalyst and is separable from solvents of catalytic reactions, confirming the nature of nanocatalysts. The present work closely investigates the unique physical and chemical features of this colloid, the formation mechanism, and the ability to act as basic nanocatalysts in benign aqueous reaction systems.

  20. Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses

    NASA Astrophysics Data System (ADS)

    Jensen, Ralph J.; Rizzo, Joseph F. III

    2009-06-01

    We and other research groups are designing an electronic retinal prosthesis to provide vision for patients who are blind due to photoreceptor degeneration. In this study, we examined the effect of stimulus waveform on the amount of current needed to activate retinal ganglion cells (RGCs) when the retinal neural network is stimulated. Isolated retinas of wild-type and rd1 mice were stimulated with cathodal and anodal monophasic current pulses of 1 ms duration and symmetric biphasic current pulses (1 ms per phase) delivered through an electrode that was located subretinally. For both wild-type and rd1 mouse retinas, cathodal current pulses were least effective in activating most RGCs. The median threshold current for a cathodal current pulse was 2.0-4.4 fold higher than the median threshold current for either an anodal or a biphasic current pulse. In wild-type mouse retinas, the median threshold current for activating RGCs with anodal current pulses was 23% lower than that with biphasic current pulses. In rd1 mouse retinas, the median threshold currents for anodal and biphasic current pulses were about the same. However, the variance in thresholds of rd1 RGCs for biphasic pulse stimulation was much smaller than for anodal pulse stimulation. Thus, a symmetric biphasic current pulse may be the best stimulus for activating the greatest number of RGCs in retinas devoid of photoreceptors.

  1. Benign Pulmonary Metastasizing Leiomyoma of the Uterus

    PubMed Central

    Iscan, Reyyan; Köse, Gültekin; Kaban, Isik

    2016-01-01

    Benign Metastasizing Leiomyoma (BML) is a rare disease which represents with multiple leiomyomatous lesions in many tissues and organs especially in lungs. These patients have been operated for leiomyoma of the uterus. Here we report a case of a 41-year-old woman who was evaluated in a thoracic surgery hospital for dyspnea and bilateral nodules in chest roentgenogram. She had no history of neoplasm, only myomectomy history of uterine leiomyoma 10 years ago. Biopsy and histopathological examination were consistent with pulmonary leiomyoma. The patient was reffered to our clinic and we performed a total abdominal hysterectomy for her multiple uterine leiomyomas. The final diagnosis was ‘benign pulmonary metastasizing leiomyoma’. After this diagnosis, surgical castration was performed but two years later, repeat imaging showed progression in pulmonary lesions and progesterone therapy was administered to the patient. Patient has continued on this hormonal therapy to date and during the 5-years follow-up, the persisting lesions in both lungs regressed. PMID:27790528

  2. Benign hypersensitivity reactions to smallpox vaccine.

    PubMed

    Bessinger, G Todd; Smith, Sidney B; Olivere, Joseph W; James, Bruce L

    2007-05-01

    With the reinstitution of smallpox vaccinations, physicians are seeing significant numbers of adverse events for the first time since the 1980s. The most common adverse events seen in our large military population are benign. We observed a clinically and histopathologically distinct reaction pattern that has not been fully characterized previously. All smallpox-vaccinated patients at Fort Hood, Texas with adverse cutaneous reactions were referred to the dermatology clinic at Darnall Army Community Hospital. Patients were evaluated by a staff dermatologist who performed a skin biopsy and took clinical photographs. If the patients had intact vesicles or pustules, direct fluorescent antibody testing, viral and bacterial cultures, and polymerase chain reaction (PCR) assays were also performed. Three hypersensitivity reaction patterns were seen: exanthematous, erythema multiforme-like (EM-like), and urticarial. The patterns had distinct clinical and histopathologic findings. Of the 11,058 vaccinees, six had the exanthematous reaction pattern, two had the urticarial reaction pattern, and one had the EM-like pattern. We describe a new exanthematous type of hypersensitivity reaction to the smallpox vaccine. Hypersensitivity reactions occur at a rate higher than previously reported. In a carefully screened military population, these three hypersensitivity reactions are much more common than life-threatening or serious reactions. Although the reactions have distinct clinical and pathologic features, they are all characterized by mild or absent systemic symptoms and a benign outcome.

  3. Diagnosis and management of benign prostatic hyperplasia.

    PubMed

    Edwards, Jonathan L

    2008-05-15

    Benign prostatic hyperplasia is a common condition affecting older men. Typical presenting symptoms include urinary hesitancy, weak stream, nocturia, incontinence, and recurrent urinary tract infections. Acute urinary retention, which requires urgent bladder catheterization, is relatively uncommon. Irreversible renal damage is rare. The initial evaluation should assess the frequency and severity of symptoms and the impact of symptoms on the patient's quality of life. The American Urological Association Symptom Index is a validated instrument for the objective assessment of symptom severity. The initial evaluation should also include a digital rectal examination and urinalysis. Men with hematuria should be evaluated for bladder cancer. A palpable nodule or induration of the prostate requires referral for assessment to rule out prostate cancer. For men with mild symptoms, watchful waiting with annual reassessment is appropriate. Over the past decade, numerous medical and surgical interventions have been shown to be effective in relieving symptoms of benign prostatic hyperplasia. Alpha blockers improve symptoms relatively quickly. Although 5-alpha reductase inhibitors have a slower onset of action, they may decrease prostate size and alter the disease course. Limited evidence shows that the herbal agents saw palmetto extract, rye grass pollen extract, and pygeum relieve symptoms. Transurethral resection of the prostate often provides permanent relief. Newer laser-based surgical techniques have comparable effectiveness to transurethral resection up to two years after surgery with lower perioperative morbidity. Various outpatient surgical techniques are associated with reduced morbidity, but symptom relief may be less durable.

  4. MIPs in Aqueous Environments.

    PubMed

    Wan, Ying-chun; Ma, Hui-ting; Lu, Bin

    2015-01-01

    When organic solvent-compatible molecularly imprinted polymers (MIPs) are used in aqueous environment, how to reduce nonspecific binding is a major challenge. By modifying the binding solvents and introducing appropriate washing and elution steps, even relatively hydrophobic MIPs can gain optimal rebinding selectivity in aqueous conditions. Furthermore, water-compatible MIPs that can be used to treat aqueous samples directly have been prepared. The use of hydrophilic co-monomers, the controlled surface modification through controlled radical polymerization, and the new interfacial molecular imprinting methods are different strategies to prepare water-compatible MIPs. By combining MIPs with other techniques, both organic solvent-compatible and water-compatible MIPs can display better functional performances in aqueous conditions. Intensive studies on MIPs in aqueous conditions can provide new MIPs with much-improved compatibilities that will lead to more interesting applications in biomedicine and biotechnology.

  5. Robotic surgery for benign gynaecological disease.

    PubMed

    Liu, Hongqian; Lu, DongHao; Wang, Lei; Shi, Gang; Song, Huan; Clarke, Jane

    2012-02-15

    Robotic surgery is the latest innovation in the field of minimally invasive surgery. In the case of robotic surgery, instead of directly moving the instruments the surgeon uses a robotic system to control the instruments for surgical procedures. Robotic surgical systems have been used in various gynaecological surgeries for benign disease, such as hysterectomy (removal of the uterus), myomectomy (removal of uterine leiomyomas) and tubal reanastomosis (the reuniting of a divided tube). The mounting evidence demonstrates the feasibility and safety of robotic surgery in benign gynaecological disease. Robotic surgery is advertised as having promising advantages including more precise vision and procedures, improved ergonomics and shorter length of hospital stay. However, the main disadvantages of the robotic surgical system should not be overlooked, including the high cost of disposable instruments and retraining for both surgeons and nurses. To assess the effectiveness and safety of robot-assisted surgery in the treatment of benign gynaecological disease. We searched the Cochrane Menstrual Disorders and Subfertility Group's Trial Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2011), MEDLINE and EMBASE up to November 2011 and citation lists of relevant publications. All randomised controlled trials (RCTs) comparing robotic surgery for benign gynaecological disease to laparoscopic or open surgical procedures. RCTs comparing different types of robotic assistants were also included. We contacted study authors for unpublished information, but failed in obtaining a response. Two review authors independently screened studies for inclusion. The domains assessed for risk of bias were allocation concealment, blinding, incomplete outcome data and selective outcome reporting. Odds ratios (OR) were used for reporting dichotomous data with 95% confidence intervals (CI), whilst mean differences (MD) were determined for continuous data. Statistical

  6. Benign Cystic Mesothelioma: A Rare Cause for Scrotal Swelling

    PubMed Central

    Aber, A.; Tahir, A.; Arumuham, V.; Smith, G.; Almpanis, S.

    2012-01-01

    Benign cystic mesothelioma of the tunica vaginalis is a rare occurrence. It usually presents with painless gradual swelling in the scrotum. These types of benign mesotheliomas typically occur in the peritoneum and usually affect young to middle-aged patients. We present in this case an unusual case of benign cystic mesothelioma of the tunica vaginalis in a 77-year-old male patient. PMID:22675366

  7. [Benign metastasizing pulmonary leiomyomatosis. A report of 3 cases].

    PubMed

    Pifarré, R; Izquierdo, J; Calatrava, A; Martínez, C; Ruiz, J; Morera, J

    1999-12-01

    The benign metastasizing leiomyoma is an uncommon variety of leiomyoma, tumor derived from smooth muscular tissue. The benign metastasizing leiomyoma affects a middle age women, with antecedents of uterine leiomyoma, the pulmonary lesions appeared as a multiple nodules, without systemic affectation. We present three cases of benign metastasizing leiomyoma that de diagnosis was made for biopsy by thoracotomy; and in one case the markers from estrogens' receivers were positive.

  8. 16-Channel biphasic current-mode programmable charge balanced neural stimulation.

    PubMed

    Li, Xiaoran; Zhong, Shunan; Morizio, James

    2017-08-14

    Neural stimulation is an important method used to activate or inhibit action potentials of the neuronal anatomical targets found in the brain, central nerve and peripheral nerve. The neural stimulator system produces biphasic pulses that deliver balanced charge into tissue from single or multichannel electrodes. The timing and amplitude of these biphasic pulses are precisely controlled by the neural stimulator software or imbedded algorithms. Amplitude mismatch between the anodic current and cathodic current of the biphasic pulse will cause permanently damage for the neural tissues. The main goal of our circuit and layout design is to implement a 16-channel biphasic current mode programmable neural stimulator with calibration to minimize the current mismatch caused by inherent complementary metal oxide semiconductor (CMOS) manufacturing processes. This paper presents a 16-channel constant current mode neural stimulator chip. Each channel consists of a 7-bit controllable current DAC used as sink and source current driver. To reduce the LSB quantization error and the current mismatch, an automatic calibration circuit and flow diagram is presented in this paper. There are two modes of operation of the stimulator chip-namely, stimulation mode and calibration mode. The chip also includes a digital interface used to control the stimulator parameters and calibration levels specific for each individual channel. This stimulator Application Specific Integrated Circuit (ASIC) is designed and fabricated in a 0.18 μm High-Voltage CMOS technology that allows for ±20 V power supply. The full-scale stimulation current was designed to be at 1 mA per channel. The output current was shown to be constant throughout the timing cycles over a wide range of electrode load impedances. The calibration circuit was also designed to reduce the effect of CMOS process variation of the P-channel metal oxide semiconductor (PMOS) and N-channel metal oxide semiconductor (NMOS) devices that will

  9. The appendix: a spectrum of benign and malignant disease.

    PubMed

    Lord, Christopher; Broadhurst, Jack; Sleight, Simon; McGee, Shaun; Wills, Mark

    2017-02-02

    This article discusses the radiological appearances and subsequent management of a diverse spectrum of benign and malignant appendiceal pathologies, including those masquerading as acute appendicitis.

  10. Ruthenium hydroxide supported on magnetic nanoparticles: a benign aqueous protocol for hydration of nitriles

    EPA Science Inventory

    Amides are an important class of compounds in the chemical and pharmaceutical industry1,2. Conventionally, amides have been synthesized by the hydration of nitriles, catalyzed by strong acids3 and bases4. Many by-products such as carboxylic acids are produced due to hydrolysis of...

  11. Ruthenium hydroxide supported on magnetic nanoparticles: a benign aqueous protocol for hydration of nitriles

    EPA Science Inventory

    Amides are an important class of compounds in the chemical and pharmaceutical industry1,2. Conventionally, amides have been synthesized by the hydration of nitriles, catalyzed by strong acids3 and bases4. Many by-products such as carboxylic acids are produced due to hydrolysis of...

  12. Clinical characteristics of bladder urothelial tumors in male patients--the influences of benign prostatic hyperplasia/benign prostatic enlargement.

    PubMed

    Zhang, Nian-Zhao; Chen, Jun; Ma, Lin; Xu, Zhi-Shun

    2012-09-01

    To investigate the clinical characteristics of bladder urothelial tumors in male patients. The clinical characteristics of 356 patients with newly diagnosed bladder urothelial tumors from July 2005 to January 2010 were analyzed. Characteristics of different age groups were compared. Furthermore, tumor characteristics were analyzed to define the relationship, if any, with benign prostatic hyperplasia/benign prostatic enlargement. For bladder urothelial tumors, the percentage of carcinoma increased significantly with increasing age (P < 0.001), and differences were found among 3 age groups in the distribution of high grade carcinoma (P = 0.012). Especially in non-muscle-invasive carcinoma, the percentage of high grade carcinoma increased significantly with increasing age (P = 0.006), with significant differences between the ≤50 years group and the 51-69 years group and ≥70 years group (P = 0.031, P = 0.002). Interestingly, compared with non-benign prostatic hyperplasia/benign prostatic enlargement patients, benign prostatic hyperplasia/benign prostatic enlargement patients were more frequently diagnosed with poorly differentiated tumors, and logistic regression confirmed associations between benign prostatic hyperplasia/benign prostatic enlargement and unfavorable carcinoma, controlling for age (P = 0.009). Age is an unfavorable influence on the clinical characteristics of bladder urothelial tumors in men, and it was observed that the percentage of unfavorable tumors increased with age. Interestingly, noticeable changes of tumor differentiation appeared at the age of 50 years, and it was indicated that the natural history of carcinoma appeared to differ according to benign prostatic hyperplasia/benign prostatic enlargement statuses. There was a tendency for the men, who were diagnosed with benign prostatic hyperplasia/benign prostatic enlargement, to present with unfavorable carcinoma. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Advantages of robotics in benign gynecologic surgery.

    PubMed

    Truong, Mireille; Kim, Jin Hee; Scheib, Stacey; Patzkowsky, Kristin

    2016-08-01

    The purpose of this article is to review the literature and discuss the advantages of robotics in benign gynecologic surgery. Minimally invasive surgery has become the preferred route over abdominal surgery. The laparoscopic or robotic approach is recommended when vaginal surgery is not feasible. Thus far, robotic gynecologic surgery data have demonstrated feasibility, safety, and equivalent clinical outcomes in comparison with laparoscopy and better clinical outcomes compared with laparotomy. Robotics was developed to overcome challenges of laparoscopy and has led to technological advantages such as improved ergonomics, visualization with three-dimensional capabilities, dexterity and range of motion with instrument articulation, and tremor filtration. To date, applications of robotics in benign gynecology include hysterectomy, myomectomy, endometriosis surgery, sacrocolpopexy, adnexal surgery, tubal reanastomosis, and cerclage. Though further data are needed, robotics may provide additional benefits over other approaches in the obese patient population and in higher complexity cases. Challenges that arose in the earlier adoption stage such as the steep learning curve, costs, and operative times are becoming more optimized with greater experience, with implementation of robotics in high-volume centers and with improved training of surgeons and robotic teams. Robotic laparoendoscopic single-site surgery, albeit still in its infancy where technical advantages compared with laparoscopic single-site surgery are still unclear, may provide a cost-reducing option compared with multiport robotics. The cost may even approach that of laparoscopy while still conferring similar perioperative outcomes. Advances in robotic technology such as the single-site platform and telesurgery, have the potential to revolutionize the field of minimally invasive gynecologic surgery. Higher quality evidence is needed to determine the advantages and disadvantages of robotic surgery in benign

  14. Environmentally benign processing of YAG transparent wafers

    NASA Astrophysics Data System (ADS)

    Yang, Yan; Wu, Yiquan

    2015-12-01

    Transparent yttrium aluminum garnet (YAG) wafers were successfully produced via aqueous tape casting and vacuum sintering techniques using a new environmentally friendly binder, a copolymer of isobutylene and maleic anhydride with the commercial name ISOBAM (noted as ISOBAM). Aqueous YAG slurries were mixed by ball-milling, which was followed by de-gassing and tape casting of wafers. The final YAG green tapes were homogenous and flexible, and could be bent freely without cracking. After the drying and sintering processes, transparent YAG wafers were achieved. The microstructures of both the green tape and vacuum-sintered YAG ceramic were observed by scanning electronic microscopy (SEM). Phase compositions were examined by X-ray diffraction (XRD). Optical transmittance was measured in UV-VIS regions with the result that the transmittance is 82.6% at a wavelength of 800 nm.

  15. Microbial side-chain cleavage of phytosterols by mycobacteria in vegetable oil/aqueous two-phase system.

    PubMed

    Xu, Yang-Guang; Guan, Yi-Xin; Wang, Hai-Qing; Yao, Shan-Jing

    2014-09-01

    Microbial side-chain cleavage of natural sterols to 4-androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD) by Mycobacteria has received much attention in pharmaceutical industry, while low yield of the reaction owing to the strong hydrophobicity of sterols is a tough problem to be solved urgently. Eight kinds of vegetable oils, i.e., sunflower, peanut, corn, olive, linseed, walnut, grape seed, and rice oil, were used to construct oil/aqueous biphasic systems in the biotransformation of phytosterols by Mycobacterium sp. MB 3683 cells. The results indicated that vegetable oils are suitable for phytosterol biotransformation. Specially, the yield of AD carried out in sunflower biphasic system (phase ratio of 1:9, oil to aqueous) was greatly increased to 84.8 % with 10 g/L feeding concentration after 120-h transformation at 30 °C and 200 rpm. Distribution coefficients of AD in different oil/aqueous systems were also determined. Because vegetable oils are of low cost and because of their eco-friendly characters, there is a great potential for the application of oil/aqueous two-phase systems in bacteria whole cell biocatalysis.

  16. Operation and Performance of a Biphase Turbine Power Plant at the Cerro Prieto Geothermal Field (Final Report)

    SciTech Connect

    Hays, Lance G.

    2000-09-01

    A full scale, wellhead Biphase turbine was manufactured and installed with the balance of plant at Well 103 of the Cerro Prieto geothermal resource in Baja, California. The Biphase turbine was first synchronized with the electrical grid of Comision Federal de Electricidad on August 20, 1997. The Biphase power plant was operated from that time until May 23, 2000, a period of 2 years and 9 months. A total of 77,549 kWh were delivered to the grid. The power plant was subsequently placed in a standby condition pending replacement of the rotor with a newly designed, higher power rotor and replacement of the bearings and seals. The maximum measured power output of the Biphase turbine, 808 kWe at 640 psig wellhead pressure, agreed closely with the predicted output, 840 kWe. When combined with the backpressure steam turbine the total output power from that flow would be increased by 40% above the power derived only from the flow by the present flash steam plant. The design relations used to predict performance and design the turbine were verified by these tests. The performance and durability of the Biphase turbine support the conclusion of the Economics and Application Report previously published, (Appendix A). The newly designed rotor (the Dual Pressure Rotor) was analyzed for the above power condition. The Dual Pressure Rotor would increase the power output to 2064 kWe by incorporating two pressure letdown stages in the Biphase rotor, eliminating the requirement for a backpressure steam turbine. The power plant availability was low due to deposition of solids from the well on the Biphase rotor and balance of plant problems. A great deal of plant down time resulted from the requirement to develop methods to handle the solids and from testing the apparatus in the Biphase turbine. Finally an online, washing method using the high pressure two-phase flow was developed which completely eliminated the solids problem. The availability of the Biphase turbine itself was 100

  17. Risk stratification for benign prostatic hyperplasia.

    PubMed

    Zattoni, Fabio; Ficarra, Vincenzo; Novara, Giacomo

    2017-03-18

    Benign prostatic hyperplasia (BPH) represents an important public health problem in ageing men due to frequently associated lower urinary tract symptoms (LUTS), which may impair quality of life. BPH is also a progressive disease, mainly characterized by a worsening of LUTS over time, and in some patients by the occurrence of serious outcomes such as acute urinary retention and need for BPH-related surgery. The management of BPH and LUTS in men should move forward its focus on symptom control only. Indeed, the goals of therapy for BPH are not only to improve bothersome LUTS but also to identify those patients at risk of unfavourable outcomes in order to optimize their management and reduce complications. Risk stratification and tailored treatment should improve the reductions in both symptoms and the long-term consequences of BPH and BPH treatments. To do this, clinicians need to know possible factors that may support the develop of PBH and possible risks due to the BPH itself.

  18. Remote Recurrence of Benign Multicystic Peritoneal Mesothelioma.

    PubMed

    Lee, Caroline E; Agrawal, Anita

    2017-07-18

    Benign peritoneal cystic mesothelioma (BPCM) is a rare disease entity that arises from mesothelioma cells. We describe a rare case of BPCM recurrence 36 years after its initial presentation. A 62-year-old woman was referred to an outpatient gynaecologic oncology clinic with an incidental finding of multiple pelvic cysts. She had a preceding history of known BPCM treated with extensive debulking surgery. She presented after 36 years of clinical remission. A repeat laparotomy for a debulking surgical procedure confirmed a recurrence of BPCM. Our current case represents a woman with a remote recurrence of BPCM after initial optimal debulking surgery. Her clinical presentation of recurrence after 36 years illustrates the need for long-term follow-up and clinical suspicion in symptomatic patients with previously diagnosed BPCM. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  19. Benign prostatic hyperplasia: clinical manifestations and evaluation.

    PubMed

    Santos Dias, José

    2012-12-01

    Benign prostatic hyperplasia (BPH) is a very common condition, related to aging and causing symptoms, called lower urinary tract symptoms. On account of its huge prevalence, it is important for clinicians who are involved in the management of patients with BPH to be aware of the very strict recommendations for BPH evaluation. In this article, we describe the different steps and procedures doctors should follow to evaluate these patients; symptoms and signs of BPH are reviewed, as well as the clinical evaluation steps and examinations available. The basic evaluation of the patients with BPH should include, according to the recommendations of the most relevant international guidelines, lower urinary tract symptoms evaluation with appropriate symptom scores, digital rectal examination, voiding charts, prostate-specific antigen and creatinine measurement, urinalysis, and imaging of the urinary tract.

  20. Saw palmetto and benign prostatic hyperplasia.

    PubMed

    Gong, Edward M; Gerber, Glenn S

    2004-01-01

    Benign prostatic hyperplasia (BPH) is a common health issue that affects 8% of all men at the age of 40, 60% of men in their 70s, and 90% of those greater than 80 years of age. One-fourth of these men will develop moderate to severe lower urinary tract symptoms that greatly affect their quality of life. Recent evidence suggests that the use of saw palmetto leads to improvements in urinary function for those suffering from BPH. The favorable comparison of saw palmetto with tamsulosin, a well-known first line agent in the treatment of urinary tract symptoms, demonstrates promise towards a beneficial effect of this herbal agent, with very few, if any, adverse effects. However, what degree of this beneficial activity is due to placebo effects is yet to be determined. In addition, the precise mechanism of action of saw palmetto in men with BPH remains unclear.

  1. Menopause and benign paroxysmal positional vertigo.

    PubMed

    Ogun, Oluwaseye Ayoola; Büki, Bela; Cohn, Edward S; Janky, Kristen L; Lundberg, Yunxia Wang

    2014-08-01

    This study was designed to examine the age and sex distribution and the effects of menopause in a large cohort of participants diagnosed with benign paroxysmal positional vertigo (BPPV). We analyzed 1,377 BPPV patients and surveyed 935 women from this group-all diagnosed at the Boys Town National Research Hospital in the last decade. A detailed age and sex distribution analysis of BPPV onset showed that aging had a profound impact on BPPV occurrence in both sexes, and that perimenopausal women were especially susceptible to BPPV (3.2:1 female-to-male ratio). The latter is a novel finding and was confirmed by a direct survey of female BPPV patients (168 participated). In addition, there was a pronounced female preponderance (6.8:1 female-to-male ratio) in BPPV in the teenage group despite its low prevalence in this age group. Data suggest that hormonal fluctuations (especially during menopause) may increase the tendency to develop BPPV.

  2. Transurethral microwave hyperthermia in benign prostatic hyperplasia

    NASA Astrophysics Data System (ADS)

    Petrovich, Zbigniew; Ameye, Filip; Baert, Luc

    1992-09-01

    Benign prostatic hyperplasia (BPH) is a common disease affecting past middle-aged males. Surgical treatment has been successfully used since the early 1900s. Currently, nonsurgical treatment modalities are under intensive study in BPH patients who have relative contraindications to surgery. Transurethral microwave hyperthermia (TUHT) is one of these modalities under study. TUHT has been applied in five to ten treatment sessions. The treatments were well tolerated with no major toxicity being reported. In BPH patients with predominance of median lobe or median bar enlargement the treatment efficacy was reduced to 30%. The effectiveness of TUHT was of particular importance in patients who had urinary retention. In the group 72% had normal voiding for 12 months or longer. A strong correlation between applied temperature and response to treatment was demonstrated. Current efforts are directed toward optimization of technique and treatment schedule. A phase III prospective randomized trial is required to define the role of TUHT in the management of BPH patients.

  3. Benign adnexal masses in the adolescent.

    PubMed

    Powell, Jill K

    2004-10-01

    Adnexal masses are common in adolescents. Certain conditions will require immediate intervention, including possible torsion, medically refractory tuboovarian abscess, intra-abdominal hemorrhage with hemodynamic instability, or possible ectopic pregnancy. Further evaluation of other masses, including additional imaging or tumor markers may be indicated, especially if masses are complex, solid, or have features characteristic of benign or malignant neoplasms. Otherwise, expectant management and surveillance allow for spontaneous resolution of most masses, especially cystic masses, and prevents unnecessary surgical intervention with its potential risks and sequelae. Laparoscopy can be done in many patients, and conservative, adnexal-sparing surgery should be encouraged when possible. In addition, physicians should be familiar with signs and symptoms of postoperative complications to allow for early diagnosis and intervention.

  4. Optimizing the management of benign prostatic hyperplasia

    PubMed Central

    Elterman, Dean S.; Kaplan, Steven A.

    2012-01-01

    One of the challenges facing primary care physicians and specialists as the population ages is the management of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). While as many as 18% of men in their 40s report bother from an enlarged prostate, that figure rises dramatically, whereby 50% of men in their 50s and 90% of men in their 90s will complain of bothersome symptoms related to an enlarged prostate. Studies have shown that BPH is a progressive disease, which if left untreated can result in worsening of symptoms, acute urinary retention and renal failure. Until about 20 years ago the only management option available to urologists was surgery. In the early 1990s medical therapy emerged as the predominant treatment for BPH. Therapy may be tailored to target symptoms and progression of disease. PMID:22496710

  5. Diagnosing and treating benign paroxysmal positional vertigo.

    PubMed

    Kovar, Mary; Jepson, Terry; Jones, Susan

    2006-12-01

    Gerontological nurses play a critical role in the early recognition of benign paroxysmal positional vertigo (BPPV), a condition that accounts for approximately 50% of vertigo in older adults. BPPV results in vertigo when debris collects in one or more of the semicircular canals, most typically the posterior canal. It may be differentiated from other forms of vertigo because it results in dizziness when recumbent or with head position changes. BPPV may be successfully treated with repositioning therapy, such as the Epley maneuver. Nurses working in medical offices, longterm care facilities, and assisted living may be called on to perform this maneuver. Gerontological nurses play a key role in assessing and treating BPPV, therefore minimizing unnecessary testing and medication and reducing the suffering and expense for patients with this condition.

  6. [Isotope nephrographic studies in benign gynecologic diseases].

    PubMed

    Lamm, D

    1977-01-01

    1014 patients with benigne gynaecological diseases (functional incontinence of urine with and without displacement, myoma of uterus, ovarian tumors, chronic salpingoophoritis) were examined by means of isotope nephrogram before gynaecological treatment was begun. A group of 156 patients was parallely examined by means of chromocystoscopy and intravenous urography. For judgement of the ING-curves we applicated an extra parameter--the drain value "A"--, through which it was possible to differenciate between emptying disturbances and functional urinary transport disorders. To obtain this value it is necessary to change the position of the patients during examination. Under these conditions approximately 95% of ING-findings conformed with those vaised by intravenous urography. Giving weight to these conditions, we recommend the application of ING in gynaecology as a screening method. Criteria for optimal usage of this method are mentioned.

  7. The debate over robotics in benign gynecology.

    PubMed

    Rardin, Charles R

    2014-05-01

    The debate over the role of the da Vinci surgical robotic platform in benign gynecology is raging with increasing fervor and, as product liability issues arise, greater financial stakes. Although the best currently available science suggests that, in the hands of experts, robotics offers little in surgical advantage over laparoscopy, at increased expense, the observed decrease in laparotomy for hysterectomy is almost certainly, at least in part, attributable to the availability of the robot. In this author's opinion, the issue is not whether the robot has any role but rather to define the role in an institutional environment that also supports the safe use of vaginal and laparoscopic approaches in an integrated minimally invasive surgery program. Programs engaging robotic surgery should have a clear and self-determined regulatory process and should resist pressures in place that may preferentially support robotics over other forms of minimally invasive surgery. Copyright © 2014 Mosby, Inc. All rights reserved.

  8. Topical Delivery of Interferon Alpha by Biphasic Vesicles: Evidence for a Novel Nanopathway across the Stratum Corneum

    SciTech Connect

    Foldvari, M.; Badea, B; Wettig, S; Baboolal, D; Kumar, P; Creagh, A; Haynes, C

    2010-01-01

    Noninvasive delivery of macromolecules across intact skin is challenging but would allow for needle-free administration of many pharmaceuticals. Biphasic vesicles, a novel lipid-based topical delivery system, have been shown to deliver macromolecules into the skin. Investigation of the delivery mechanism of interferon alpha (IFN {alpha}), as a model protein, by biphasic vesicles could improve understanding of molecular transport through the stratum corneum and allow for the design of more effective delivery systems. The interaction of biphasic vesicles with human skin and isolated stratum corneum membrane was investigated by confocal microscopy, differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS and WAXS). Confocal microscopy revealed that biphasic vesicles delivered IFN {alpha} intercellularly, to a depth of 70 {micro}m, well below the stratum corneum and into the viable epidermis. DSC and SAXS/WAXS data suggest that the interaction of biphasic vesicles with SC lipids resulted in the formation of a three-dimensional cubic Pn3m polymorphic phase by the molecular rearrangement of intercellular lipids. This cubic phase could be an intercellular permeation nanopathway that may explain the increased delivery of IFN {alpha} by biphasic vesicles. Liposomes and submicrometer emulsion (the individual building blocks of biphasic vesicles) separately and methylcellulose gel, an alternative topical vehicle, did not induce a cubic phase and delivered low amounts of IFN {alpha} below the stratum corneum. Molecular modeling of the cubic Pn3m phase and lamellar-to-cubic phase transitions provides a plausible mechanism for transport of IFN {alpha}. It is hypothesized that induction of a Pn3m cubic phase in stratum corneum lipids could make dermal and transdermal delivery of other macromolecules also possible.

  9. Biphasic shocks compared with monophasic damped sine wave shocks for direct ventricular defibrillation during open heart surgery.

    PubMed

    Schwarz, Birgit; Bowdle, T Andrew; Jett, G Kimble; Mair, Peter; Lindner, Karl H; Aldea, Gabriel S; Lazzara, Robert G; O'Grady, Sharon G; Schmitt, Paul W; Walker, Robert G; Chapman, Fred W; Tacker, Willis A

    2003-05-01

    Biphasic waveform shocks are more effective than monophasic shocks for transchest ventricular defibrillation, atrial cardioversion, and defibrillation with implantable defibrillators but have not been studied for open chest, intraoperative defibrillation. This prospective, blinded, randomized clinical study compares biphasic and monophasic shock effectiveness and establishes intraoperative energy dose-response curves. Patients undergoing cardiothoracic surgery with bypass cardioplegia were randomly assigned to the monophasic or biphasic shock group. Ventricular fibrillation occurring after aortic clamp removal was treated with escalating energies of 2, 5, 7, 10, and 20 J until defibrillation occurred. If ventricular fibrillation persisted, a 20-J crossover shock of the other waveform was used. Cumulative defibrillation success at 5 J, the primary end point of the study, was higher in the biphasic group than in the monophasic group (25 of 50 vs. 9 of 41 defibrillated; P = 0.011). In addition, the biphasic group required lower threshold energy (6.8 vs. 11.0 J; P = 0.003), less cumulative energy (12.6 vs. 23.4 J; P = 0.002), and fewer shocks (2.5 vs. 3.5; P = 0.002). Crossover-shock effectiveness did not differ between groups. Dose-response curves show biphasic shocks to have higher cumulative success rates at all energies tested. Biphasic shocks are substantially more effective than monophasic shocks for direct defibrillation. The dose-response curve guides selection of first-shock energy for traditional step-up protocols. Starting at 5 J optimizes for lowest threshold and cumulative energy, whereas 10 or 20 J optimizes for more rapid defibrillation and fewer shocks.

  10. Trauma whole-body MDCT: an assessment of image quality in conventional dual-phase and modified biphasic injection.

    PubMed

    Hakim, Wasim; Kamanahalli, Raghavendra; Dick, Elizabeth; Bharwani, Nishat; Fetherston, Shirley; Kashef, Elika

    2016-07-01

    To compare the image quality of conventional arterial and portal venous (PV) phase multidetector CT (MDCT) with two biphasic injection protocols in polytrauma patients. 60 consecutive patients with polytrauma underwent body 256-slice MDCT with a conventional protocol or 1 of 2 single-pass biphasic protocols: Group A, arterial (30 s) and PV (60 s) phase acquisitions; Group B, "biphasic" contrast injection with a single acquisition at 60 s; and Group C, "modified biphasic" injection with a single acquisition at a 70-s delay. Images were analyzed for arterial, venous and parenchymal attenuation profiles with regions of interest in the major arteries, veins and solid abdominal organs. A 5-point scoring system was used to assess the image quality, with 5 representing excellent arterial, venous and parenchymal opacification and <3 representing non-diagnostic opacification. In addition, the effective dose (millisieverts) was compared between the groups. In 93% of patients, image quality was scored as good or excellent (≥4). All studies were of satisfactory diagnostic quality. Overall, venous and arterial attenuation profiles were comparable. Attenuation profiles in the solid abdominal viscera were significantly higher (p < 0.01) using both biphasic protocols than with arterial or PV phase of conventional protocols. Effective doses were higher in Group A. Comparable image quality can be achieved using a biphasic i.v. contrast injection protocol with single MDCT acquisition with less radiation and reduction in acquisition time. For these particular biphasic injection protocols, we have shown that image quality is comparable with a conventional protocol. This has been achieved by comparing enhanced densities of specific structures, as well as gestalt scoring by assessors, on a 256-slice MDCT.

  11. Aqueous lithium air batteries

    DOEpatents

    Visco, Steven J.; Nimon, Yevgeniy S.; De Jonghe, Lutgard C.; Petrov, Alexei; Goncharenko, Nikolay

    2017-05-23

    Aqueous Li/Air secondary battery cells are configurable to achieve high energy density and prolonged cycle life. The cells include a protected a lithium metal or alloy anode and an aqueous catholyte in a cathode compartment. The aqueous catholyte comprises an evaporative-loss resistant and/or polyprotic active compound or active agent that partakes in the discharge reaction and effectuates cathode capacity for discharge in the acidic region. This leads to improved performance including one or more of increased specific energy, improved stability on open circuit, and prolonged cycle life, as well as various methods, including a method of operating an aqueous Li/Air cell to simultaneously achieve improved energy density and prolonged cycle life.

  12. Reflectance of aqueous solutions

    NASA Technical Reports Server (NTRS)

    Querry, M. R.

    1972-01-01

    The optical properties and optical constants of water and aqueous solutions were studied to develop an accurate tabulation of graphical representations of the optical constants through a broad spectrum. Manuscripts of articles are presented concerning extinction coefficients, relative specular reflectance, and temperature effect on the water spectrum. Graphs of absolute reflectance, phase shifts, index of refraction, and extinction coefficients for water, heavy water and aqueous solutions are included.

  13. Aqueous two-phase system based on natural quaternary ammonium compounds for the extraction of proteins.

    PubMed

    Zeng, Chao-Xi; Xin, Rui-Pu; Qi, Sui-Jian; Yang, Bo; Wang, Yong-Hua

    2016-02-01

    Aqueous two-phase systems, based on the use of natural quaternary ammonium compounds, were developed to establish a benign biotechnological route for efficient protein separation. In this study, aqueous two-phase systems of two natural resources betaine and choline with polyethyleneglycol (PEG400/600) or inorganic salts (K2 HPO4 /K3 PO4 ) were formed. It was shown that in the K2 HPO4 -containing aqueous two-phase system, hydrophobic interactions were an important driving force of protein partitioning, while protein size played a vital role in aqueous two-phase systems that contained polyethylene glycol. An extraction efficiency of more than 90% for bovine serum albumin in the betaine/K2 HPO4 aqueous two-phase system can be obtained, and this betaine-based aqueous two-phase system provided a gentle and stable environment for the protein. In addition, after investigation of the cluster phenomenon in the betaine/K2 HPO4 aqueous two-phase systems, it was suggested that this phenomenon also played a significant role for protein extraction in this system. The development of aqueous two-phase systems based on natural quaternary ammonium compounds not only provided an effective and greener method of aqueous two-phase system to meet the requirements of green chemistry but also may help to solve the mystery of the compartmentalization of biomolecules in cells.

  14. Purification of Helicobacter suis Strains From Biphasic Cultures by Single Colony Isolation: Influence on Strain Characteristics.

    PubMed

    Liang, Jungang; De Bruyne, Ellen; Ducatelle, Richard; Smet, Annemieke; Haesebrouck, Freddy; Flahou, Bram

    2015-06-01

    Helicobacter (H.) suis causes gastritis and decreased weight gain in pigs. It is also the most prevalent non-Helicobacter pylori Helicobacter species in humans with gastric disease. H. suis is extremely fastidious, and so far, biphasic culture conditions were essential for isolation and culture, making it impossible to obtain single colonies. Hence, cultures obtained from an individual animal may contain multiple H. suis strains, which is undesirable for experiments aiming for instance at investigating H. suis strain differences. Pure cultures of H. suis were established by growing bacteria as colonies on 1% brucella agar plates, followed by purification and enrichment by biphasic subculture. Characteristics of these single colony-derived strains were compared with those of their parent strains using multilocus sequence typing (MLST) and by studying bacterium-host interactions using a gastric epithelial cell line and Mongolian gerbil model. The purification/enrichment procedure required a nonstop culture of several weeks. For 4 of 17 H. suis strains, MLST revealed differences between parental and single colony-derived strains. For three of four single colony-derived strains tested, the cell death-inducing capacity was higher than for the parental strain. One single colony-derived strain lost its capacity to colonize Mongolian gerbils. For the four other strains tested, colonization capacity and histopathologic changes were similar to what has been described when using strains with only a history of limited biphasic culture. A method was developed to obtain single colony-derived H. suis strains, but this procedure may affect the bacterial genotype and phenotype. © 2015 John Wiley & Sons Ltd.

  15. A Lagrange multiplier mixed finite element formulation for three-dimensional contact of biphasic tissues.

    PubMed

    Yang, Taiseung; Spilker, Robert L

    2007-06-01

    A three-dimensional (3D) contact finite element formulation has been developed for biological soft tissue-to-tissue contact analysis. The linear biphasic theory of Mow, Holmes, and Lai (1984, J. Biomech., 17(5), pp. 377-394) based on continuum mixture theory, is adopted to describe the hydrated soft tissue as a continuum of solid and fluid phases. Four contact continuity conditions derived for biphasic mixtures by Hou et al. (1989, ASME J. Biomech. Eng., 111(1), pp. 78-87) are introduced on the assumed contact surface, and a weighted residual method has been used to derive a mixed velocity-pressure finite element contact formulation. The Lagrange multiplier method is used to enforce two of the four contact continuity conditions, while the other two conditions are introduced directly into the weighted residual statement. Alternate formulations are possible, which differ in the choice of continuity conditions that are enforced with Lagrange multipliers. Primary attention is focused on a formulation that enforces the normal solid traction and relative fluid flow continuity conditions on the contact surface using Lagrange multipliers. An alternate approach, in which the multipliers enforce normal solid traction and pressure continuity conditions, is also discussed. The contact nonlinearity is treated with an iterative algorithm, where the assumed area is either extended or reduced based on the validity of the solution relative to contact conditions. The resulting first-order system of equations is solved in time using the generalized finite difference scheme. The formulation is validated by a series of increasingly complex canonical problems, including the confined and unconfined compression, the Hertz contact problem, and two biphasic indentation tests. As a clinical demonstration of the capability of the contact analysis, the gleno-humeral joint contact of human shoulders is analyzed using an idealized 3D geometry. In the joint, both glenoid and humeral head

  16. Biphasic fermentation is an efficient strategy for the overproduction of δ-endotoxin from Bacillus thuringiensis.

    PubMed

    Jisha, Veloorvalappil Narayanan; Smitha, Robinson Babysarojam; Priji, Prakasan; Sajith, Sreedharan; Benjamin, Sailas

    2015-02-01

    This study illustrates a biphasic solid-state fermentation (SSF) strategy for the overproduction of δ-endotoxin from Bacillus thuringiensis subsp. kurstaki (Btk) and also purification of δ-endotoxin from the solid-fermented medium. The fermentation strategy had two phases (biphasic); i.e., the first short phase was semisolid state (12 h), and the remaining long phase was strict SSF. To achieve the biphasic SSF, after 12 h (150 rpm, 37 °C) fermentation of the medium [Luria-Bertani (LB) supplemented with 30 % (w/v) raw soybean flour (phase I)], the supernatant in it was completely centrifuged out (1,000 × g, 10 min) aseptically for harvesting the extracellular enzymes as by-product. The resultant wet solid matter without free-flowing liquid but with embedded Btk was incubated 60 h more (phase II) for enhancing δ-endotoxin production at static condition (37 °C). Coupled with this, δ-endotoxin was purified by the modified phase separation method, and its purity was physically confirmed by both staining and microscopic techniques. The maximum δ-endotoxin yield from solid medium (48 h) was 15.8 mg/mL (recovery was 55-59 %) LB-equivalent, while that of LB control (recovery was 95 %) was only 0.43 mg/mL (72 h), i.e., thus, in comparison, 36.74-fold more yield in solid medium obtained by 24 h less gestation period. The purified crystal proteins showed apparent molecular weights (MWs) of 45, 35, and 6 kDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Briefly, this unique study physically demonstrates how Btk δ-endotoxin is purified (95-99 % purity) from solid-fermented matter for the first time, coupled with its overproduction at the expense of only 21.5 % higher production cost.

  17. Development of calcium phosphate/sulfate biphasic cement for vital pulp therapy.

    PubMed

    Chang, Kai-Chun; Chang, Chia-Chieh; Chen, Wei-Tang; Hsu, Chung-King; Lin, Feng-Huei; Lin, Chun-Pin

    2014-12-01

    Bioactive calcium phosphate cement (CPC) has been used widely to repair bone defects because of its excellent biocompatibility and bioactivity. However, the poor handling properties, low initial mechanical strength, and long setting time of CPC limit its application in vital pulp therapy (VPT). The aim of this study was to synthesize biphasic calcium phosphate/sulfate cements and evaluate the feasibility of applying these cements in VPT. The physical, chemical, and mechanical properties of CPC were improved by mixing the cement with various amounts of α-calcium sulfate hemihydrate (CSH). The hydration products and crystalline phases of the materials were characterized using scanning electron microscopy and X-ray diffraction analysis. In addition, the physical properties, such as the setting time, compressive strength, viscosity, and pH were determined. Water-soluble tetrazolium salt-1 and lactase dehydrogenase were used to evaluate cell viability and cytotoxicity. The developed CPC (CPC/CSH cement), which contains 50wt% CSH cement, exhibited no obvious temperature increase or pH change during setting when it was used as a paste. The initial setting time of the CPC/CSH biphasic cement was substantially shorter than that of CPC, and the initial mechanical strength was 23.7±5.6MPa. The CPC/CSH cement exhibited higher viscosity than CPC and, thus, featured acceptable handling properties. X-ray diffraction analysis revealed that the relative peak intensity for hydroxyapatite increased, and the intensity for calcium sulfate dehydrate decreased as the amount of CPC was increased. The cell viability and cytotoxicity test results indicated that the CPC/CSH cement did not harm dental pulp cells. The developed CPC/CSH biphasic cement exhibits substantial potential for application in VPT. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Isoattenuating insulinomas at biphasic contrast-enhanced CT: frequency, clinicopathologic features and perfusion characteristics.

    PubMed

    Zhu, Liang; Xue, Hua-Dan; Sun, Hao; Wang, Xuan; He, Yong-Lan; Jin, Zheng-Yu; Zhao, Yu-Pei

    2016-10-01

    We aimed to determine the frequency of isoattenuating insulinomas, to investigate their clinicopathological features and to assess their regional pancreatic perfusion characteristics. Institutional review board approval was obtained, and patient informed consent was waived. From July 2010 to June 2014, 170 patients (66 male, 104 female) with endogenous hyperinsulinemic hypoglycemia underwent biphasic contrast-enhanced CT before surgery, and 129 of those patients also received preoperative whole-pancreas CT perfusion. A total of 181 tumours were proved histopathologically after surgery. Enhancement pattern and regional pancreatic perfusion characteristics were analyzed. Clinical features, tumour size and pathological grading were investigated. The frequency of isoattenuating tumours was 24.9 %. Tumour size and WHO grading was not significantly different between isoattenuating and hyperattenuating tumours. Tumour-free regions had identical blood flow (BF) regardless of their location (p = 0.35). Isoattenuating tumour-harbouring regions had lower BF compared with hyperattenuating tumour-harbouring regions; both showed higher BF compared with tumour-free neighbourhood regions (all p < 0.01). For patients with isoattenuating tumours, the overall hospital stay was longer (p < 0.01). A substantial subset of insulinomas were isoattenuating on biphasic CT. CT perfusion showed higher BF in tumour-harbouring regions compared to tumour-free regions, providing a clue for tumour regionalization. • About a quarter of all insulinomas were isoattenuating on biphasic contrast-enhanced CT. • CT perfusion finds tumour-harbouring regions have higher blood-flow compared to tumour-free regions. • CT perfusion provides important information for tumour regionalization, for isoattenuating tumours.

  19. Addition of biphasic, prandial, or basal insulin to oral therapy in type 2 diabetes.

    PubMed

    Holman, Rury R; Thorne, Kerensa I; Farmer, Andrew J; Davies, Melanie J; Keenan, Joanne F; Paul, Sanjoy; Levy, Jonathan C

    2007-10-25

    Adding insulin to oral therapy in type 2 diabetes mellitus is customary when glycemic control is suboptimal, though evidence supporting specific insulin regimens is limited. In an open-label, controlled, multicenter trial, we randomly assigned 708 patients with a suboptimal glycated hemoglobin level (7.0 to 10.0%) who were receiving maximally tolerated doses of metformin and sulfonylurea to receive biphasic insulin aspart twice daily, prandial insulin aspart three times daily, or basal insulin detemir once daily (twice if required). Outcome measures at 1 year were the mean glycated hemoglobin level, the proportion of patients with a glycated hemoglobin level of 6.5% or less, the rate of hypoglycemia, and weight gain. At 1 year, mean glycated hemoglobin levels were similar in the biphasic group (7.3%) and the prandial group (7.2%) (P=0.08) but higher in the basal group (7.6%, P<0.001 for both comparisons). The respective proportions of patients with a glycated hemoglobin level of 6.5% or less were 17.0%, 23.9%, and 8.1%; respective mean numbers of hypoglycemic events per patient per year were 5.7, 12.0, and 2.3; and respective mean weight gains were 4.7 kg, 5.7 kg, and 1.9 kg. Rates of adverse events were similar among the three groups. A single analogue-insulin formulation added to metformin and sulfonylurea resulted in a glycated hemoglobin level of 6.5% or less in a minority of patients at 1 year. The addition of biphasic or prandial insulin aspart reduced levels more than the addition of basal insulin detemir but was associated with greater risks of hypoglycemia and weight gain. (Current Controlled Trials number, ISRCTN51125379 [controlled-trials.com].). Copyright 2007 Massachusetts Medical Society.

  20. Determination of descriptors for polycyclic aromatic hydrocarbons and related compounds by chromatographic methods and liquid-liquid partition in totally organic biphasic systems.

    PubMed

    Ariyasena, Thiloka C; Poole, Colin F

    2014-09-26

    Retention factors on several columns and at various temperatures using gas chromatography and from reversed-phase liquid chromatography on a SunFire C18 column with various mobile phase compositions containing acetonitrile, methanol and tetrahydrofuran as strength adjusting solvents are combined with liquid-liquid partition coefficients in totally organic biphasic systems to calculate descriptors for 23 polycyclic aromatic hydrocarbons and eighteen related compounds of environmental interest. The use of a consistent protocol for the above measurements provides descriptors that are more self consistent for the estimation of physicochemical properties (octanol-water, air-octanol, air-water, aqueous solubility, and subcooled liquid vapor pressure). The descriptor in this report tend to have smaller values for the L and E descriptors and random differences in the B and S descriptors compared with literature sources. A simple atom fragment constant model is proposed for the estimation of descriptors from structure for polycyclic aromatic hydrocarbons. The new descriptors show no bias in the prediction of the air-water partition coefficient for polycyclic aromatic hydrocarbons unlike the literature values. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Photoreduction of CO2 using [Ru(bpy)2(CO)L]n+ catalysts in biphasic solution/supercritical CO2 systems.

    PubMed

    Voyame, Patrick; Toghill, Kathryn E; Méndez, Manuel A; Girault, Hubert H

    2013-10-07

    The reduction of CO2 in a biphasic liquid-condensed gas system was investigated as a function of the CO2 pressure. Using 1-benzyl-1,4-dihydronicotinamide (BNAH) as sacrificial electron donor dissolved in a dimethylformamide-water mixture and [Ru(bpy)2(CO)L](n+) as a catalyst and [Ru(bpy)3](2+) as a photosensitizer, the reaction was found to produce a mixture of CO and formate, in total about 250 μmol after just 2 h. As CO2 pressure increases, CO formation is greatly favored, being four times greater than that of formate in aqueous systems. In contrast, formate production was independent of CO2 pressure, present at about 50 μmol. Using TEOA as a solvent instead of water created a single-phase supercritical system and greatly favored formate synthesis, but similarly increasing CO2 concentration favored the CO catalytic cycle. Under optimum conditions, a turnover number (TON) of 125 was obtained. Further investigations of the component limits led to an unprecedented TON of over 1000, and an initial turnover frequency (TOF) of 1600 h(-1).

  2. Activated microglia in acute encephalopathy with biphasic seizures and late reduced diffusion.

    PubMed

    Fujita, Yuji; Takanashi, Jun-Ichi; Takei, Haruka; Ota, Setsuo; Fujii, Katsunori; Sakuma, Hiroshi; Hayashi, Masaharu

    2016-07-15

    Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype of infectious pediatric encephalopathy in Japan. The exact pathogenesis of and the best therapeutic strategy for AESD are uncertain. We firstly performed a brain biopsy in a 2-year-old boy with AESD associated with RS viral infection, which revealed activated ameoboid microglia accumulation around degenerated neuron, and astrogliosis in the affected cortex. Glutamate released from activated microglia may play an important role in the pathogenesis of AESD, which is compatible with the previous report of magnetic resonance spectroscopy showing elevated glutamate. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Repair of porcine articular cartilage defect with a biphasic osteochondral composite.

    PubMed

    Jiang, Ching-Chuan; Chiang, Hongsen; Liao, Chun-Jen; Lin, Yu-Ju; Kuo, Tzong-Fu; Shieh, Chang-Shun; Huang, Yi-You; Tuan, Rocky S

    2007-10-01

    Autologous chondrocyte implantation (ACI) has been recently used to treat cartilage defects. Partly because of the success of mosaicplasty, a procedure that involves the implantation of native osteochondral plugs, it is of potential significance to consider the application of ACI in the form of biphasic osteochondral composites. To test the clinical applicability of such composite construct, we repaired osteochondral defect with ACI at low cell-seeding density on a biphasic scaffold, and combined graft harvest and implantation in a single surgery. We fabricated a biphasic cylindrical porous plug of DL-poly-lactide-co-glycolide, with its lower body impregnated with beta-tricalcium phosphate as the osseous phase. Osteochondral defects were surgically created at the weight-bearing surface of femoral condyles of Lee-Sung mini-pigs. Autologous chondrocytes isolated from the cartilage were seeded into the upper, chondral phase of the plug, which was inserted by press-fitting to fill the defect. Defects treated with cell-free plugs served as control. Outcome of repair was examined 6 months after surgery. In the osseous phase, the biomaterial retained in the center and cancellous bone formed in the periphery, integrating well with native subchondral bone with extensive remodeling, as depicted on X-ray roentgenography by higher radiolucency. In the chondral phase, collagen type II immunohistochemistry and Safranin O histological staining showed hyaline cartilage regeneration in the experimental group, whereas only fibrous tissue formed in the control group. On the International Cartilage Repair Society Scale, the experimental group had higher mean scores in surface, matrix, cell distribution, and cell viability than control, but was comparable with the control group in subchondral bone and mineralization. Tensile stress-relaxation behavior determined by uni-axial indentation test revealed similar creep property between the surface of the experimental specimen and native

  4. Use of Biphasic Continuous Positive Airway Pressure in Premature Infant with Cleft Lip–Cleft Palate

    PubMed Central

    George, Lovya; Jain, Sunil K.

    2015-01-01

    Preterm infants (PIs) often require respiratory support due to surfactant deficiency. Early weaning from mechanical ventilation to noninvasive respiratory support decreases ventilation-associated irreversible lung damage. This wean is particularly challenging in PIs with cleft lip and cleft palate due to anatomical difficulties encountered in maintaining an adequate seal for positive pressure ventilation. PI with a cleft lip and palate often fail noninvasive respiratory support and require continued intubation and mechanical ventilation. We are presenting the first case report of a PI with cleft lip and palate who was managed by biphasic nasal continuous positive airway pressure. PMID:26495158

  5. A GREENER SYNTHESIS OF CORE (FE, CU)-SHELL (AU, PT, PD AND AG) NANOCRYSTALS USING AQUEOUS VITAMIN C

    EPA Science Inventory

    A greener method to fabricate the novel core (Fe and Cu)-shell (noble metals) metal nanocrystals using aqueous ascorbic acid (vitamin C) is described. Transition metal salts such as Cu and Fe were reduced using ascorbic acid, a benign naturally available antioxidant, and then add...

  6. A GREENER SYNTHESIS OF CORE (FE, CU)-SHELL (AU, PT, PD AND AG) NANOCRYSTALS USING AQUEOUS VITAMIN C

    EPA Science Inventory

    A greener method to fabricate the novel core (Fe and Cu)-shell (noble metals) metal nanocrystals using aqueous ascorbic acid (vitamin C) is described. Transition metal salts such as Cu and Fe were reduced using ascorbic acid, a benign naturally available antioxidant, and then add...

  7. Pygeum africanum for benign prostatic hyperplasia.

    PubMed

    Wilt, T; Ishani, A; Mac Donald, R; Rutks, I; Stark, G

    2002-01-01

    Benign prostatic hyperplasia (BPH), nonmalignant enlargement of the prostate, can lead to obstructive and irritative lower urinary tract symptoms (LUTS). The pharmacologic use of plants and herbs (phytotherapy) for the treatment of LUTS associated with BPH has been growing steadily. The extract of the African prune tree, Pygeum africanum, is one of the several phytotherapeutic agents available for the treatment of BPH. To investigate the evidence whether extracts of Pygeum africanum (1) are more effective than placebo in the treatment of Benign Prostatic Hyperplasia (BPH), (2) are as effective as standard pharmacologic BPH treatments, and (3) have less side effects compared to standard BPH drugs. Trials were searched in computerized general and specialized databases (MEDLINE (1966-2000), EMBASE, Cochrane Library, Phytodok), by checking bibliographies, and by contacting relevant manufacturers and researchers. Trials were eligible if they (1) were randomized (2) included men with BPH (3) compared preparations of Pygeum africanum (alone or in combination) with placebo or other BPH medications (4) included clinical outcomes such as urologic symptom scales, symptoms, or urodynamic measurements. Eligibility was assessed by at least two independent observers. Information on patients, interventions, and outcomes were extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of Pygeum africanum with placebo and standard BPH medications was the change in urologic symptoms scale scores. Secondary outcomes included change in urologic symptoms including nocturia and urodynamic measures (peak and mean urine flow, prostate size). The main outcome measure for adverse effects was the number of men reporting adverse effects. A total of 18 randomized controlled trials involving 1562 men met inclusion criteria and were analyzed. Only one of the studies reported a method of treatment allocation concealment, though 17

  8. Sidefiring laser-fiber technology for minimally invasive transurethral treatment of benign prostatic hyperplasia

    NASA Astrophysics Data System (ADS)

    Judy, Millard M.; Matthews, James Lester; Gardetto, W. W.; Everett, R. V.; Lahon, H. A.

    1993-07-01

    We have designed and are fabricating the SideFireR laser optical fiber device incorporating a 99.95+% purity gold tip with a mirror which laterally reflects the beam at a 105 degree(s) angle to the optical fiber axis while closely maintaining the beam profile. The monolithic gold construction of the mirrored tip underlies the optical and thermal stability and the bicompatibility of the device during lasing in aqueous environments using up to 80 W of Nd:YAG 1.064 micrometers radiation. Current studies are being conducted to evaluate the use of this device in laser coagulation of the prostate as an alternative treatment to transurethral resection in treatment of benign prostatic hypertrophy.

  9. Diode Laser Excision of Oral Benign Lesions

    PubMed Central

    Mathur, Ena; Sareen, Mohit; Dhaka, Payal; Baghla, Pallavi

    2015-01-01

    Introduction: Lasers have made tremendous progress in the field of dentistry and have turned out to be crucial in oral surgery as collateral approach for soft tissue surgery. This rapid progress can be attributed to the fact that lasers allow efficient execution of soft tissue procedures with excellent hemostasis and field visibility. When matched to scalpel, electrocautery or high frequency devices, lasers offer maximum postoperative patient comfort. Methods: Four patients agreed to undergo surgical removal of benign lesions of the oral cavity. 810 nm diode lasers were used in continuous wave mode for excisional biopsy. The specimens were sent for histopathological examination and patients were assessed on intraoperative and postoperative complications. Results: Diode laser surgery was rapid, bloodless and well accepted by patients and led to complete resolution of the lesions. The excised specimen proved adequate for histopathological examination. Hemostasis was achieved immediately after the procedure with minimal postoperative problems, discomfort and scarring. Conclusion: We conclude that diode lasers are rapidly becoming the standard of care in contemporary dental practice and can be employed in procedures requiring excisional biopsy of oral soft tissue lesions with minimal problems in histopathological diagnosis. PMID:26464781

  10. Magnetic resonance imaging of benign prostatic hyperplasia.

    PubMed

    Guneyli, Serkan; Ward, Emily; Thomas, Stephen; Yousuf, Ambereen Nehal; Trilisky, Igor; Peng, Yahui; Antic, Tatjana; Oto, Aytekin

    2016-01-01

    Benign prostatic hyperplasia (BPH) is a common condition in middle-aged and older men and negatively affects the quality of life. An ultrasound classification for BPH based on a previous pathologic classification was reported, and the types of BPH were classified according to different enlargement locations in the prostate. Afterwards, this classification was demonstrated using magnetic resonance imaging (MRI). The classification of BPH is important, as patients with different types of BPH can have different symptoms and treatment options. BPH types on MRI are as follows: type 0, an equal to or less than 25 cm3 prostate showing little or no zonal enlargements; type 1, bilateral transition zone (TZ) enlargement; type 2, retrourethral enlargement; type 3, bilateral TZ and retrourethral enlargement; type 4, pedunculated enlargement; type 5, pedunculated with bilateral TZ and/or retrourethral enlargement; type 6, subtrigonal or ectopic enlargement; type 7, other combinations of enlargements. We retrospectively evaluated MRI images of BPH patients who were histologically diagnosed and presented the different types of BPH on MRI. MRI, with its advantage of multiplanar imaging and superior soft tissue contrast resolution, can be used in BPH patients for differentiation of BPH from prostate cancer, estimation of zonal and entire prostatic volumes, determination of the stromal/glandular ratio, detection of the enlargement locations, and classification of BPH types which may be potentially helpful in choosing the optimal treatment.

  11. Magnetic resonance imaging of benign prostatic hyperplasia

    PubMed Central

    Guneyli, Serkan; Ward, Emily; Thomas, Stephen; Yousuf, Ambereen Nehal; Trilisky, Igor; Peng, Yahui; Antic, Tatjana; Oto, Aytekin

    2016-01-01

    Benign prostatic hyperplasia (BPH) is a common condition in middle-aged and older men and negatively affects the quality of life. An ultrasound classification for BPH based on a previous pathologic classification was reported, and the types of BPH were classified according to different enlargement locations in the prostate. Afterwards, this classification was demonstrated using magnetic resonance imaging (MRI). The classification of BPH is important, as patients with different types of BPH can have different symptoms and treatment options. BPH types on MRI are as follows: type 0, an equal to or less than 25 cm3 prostate showing little or no zonal enlargements; type 1, bilateral transition zone (TZ) enlargement; type 2, retrourethral enlargement; type 3, bilateral TZ and retrourethral enlargement; type 4, pedunculated enlargement; type 5, pedunculated with bilateral TZ and/or retrourethral enlargement; type 6, subtrigonal or ectopic enlargement; type 7, other combinations of enlargements. We retrospectively evaluated MRI images of BPH patients who were histologically diagnosed and presented the different types of BPH on MRI. MRI, with its advantage of multiplanar imaging and superior soft tissue contrast resolution, can be used in BPH patients for differentiation of BPH from prostate cancer, estimation of zonal and entire prostatic volumes, determination of the stromal/glandular ratio, detection of the enlargement locations, and classification of BPH types which may be potentially helpful in choosing the optimal treatment. PMID:27015442

  12. [Benign pleural effusion caused by asbestos exposure].

    PubMed

    Vieira, J R; Alfarroba, E; Viegas, J; Freitas e Costa, M

    1992-05-01

    The Authors present the first case described among us of benign pleural effusion of an asbestotic origin. They stress the importance of thoracoscopy (pleuroscopy) in the diagnosis of this situation. Attention is drawn to the fact that asbestotic lesions and asbestotic bodies have been found in the lung and, in particular, in the parietal pleura as well. They emphasize the fact that exposure to asbestos was not realized by the patient, which made the clarification of the situation more difficult. It was a CT scan that showed the signs suggestive of exposure to asbestos which raised the diagnostic suspicion. They conclude that every patient with a pleural effusion must be thoroughly questioned about exposure to asbestos. Even if the exposure is accepted, they consider that one should proceed to a pleuro-pulmonar biopsy by thoracoscopy. This biopsy allows demonstration of the characteristic histopathological lesions and rule out other etiologies, namely malignancy and tuberculosis. They suggest that these patients must be highly motivated to stop any smoking and kept under periodic surveillance.

  13. Cat Scratch Disease: Not a Benign Condition.

    PubMed

    Barros, Sandra; De Andrade, Gabriel Costa; Cavalcanti, Cecilia; Nascimento, Heloisa

    2017-06-30

    Describe a case series of ocular Cat-scratch-disease (CSD) with vision-threatening findings and poor outcomes, indicating severity of disease. Retrospective case series from the Uveitis Department of São Paulo Federal University from 2011 to 2015. In this period, six eyes of four patients had confirmed diagnosis of CSD. Two were male and two female. Mean age was 24.8 years old [7-45]. Two had bilateral disease. Visual acuity at presentation ranged from no light perception to 20/25. Three patients were treated with doxycycline and one with clarithromycin and prednisone. Visual outcome after treatment ranged from counting fingers to 20/20: 5/6 eyes had final visual acuity of less than 20/40 and 3/6 had final visual acuity equal or less than 20/400. Although usually described as a benign disease with spontaneous resolution, CSD can present with atypical manifestations such as vascular angiomatous lesions, serous retinal detachment, and vascular occlusion syndromes, carrying a severe course and guarded prognosis.

  14. Laparoscopy for Benign Diseases of the Colon.

    PubMed

    Smith, Radhika; Maron, David J

    2017-04-01

    Laparoscopic surgery has revolutionized the delivery of care to the surgical patient undergoing colorectal resection. Since the first laparoscopic-assisted colectomy in 1991, significant advances have been made in minimally invasive colorectal surgery. For many benign conditions, laparoscopic colectomy has been proven to be safe and effective, and in some instances superior when compared with open surgery. Complex laparoscopic resections such as those for diverticulitis and inflammatory bowel disease have also been shown to have equivalent outcomes when compared with open surgery. Short-term benefits of a minimally invasive approach include less pain, decreased rates of wound infection and postoperative morbidity, faster return of bowel function, and shorter length of stay. Improvements in long-term complications have also been noted with lower incidence of incisional hernias and small bowel obstructions secondary to adhesions. As surgeons become more facile with laparoscopic resection, more complex cases such as those for complicated diverticulitis and reoperative surgery for inflammatory bowel disease can be completed with shorter operative times and decreased cost.

  15. Benign paroxysmal positional vertigo: diagnosis and treatment.

    PubMed

    Salvinelli, F; Firrisi, L; Casale, M; Trivelli, M; D'Ascanio, L; Lamanna, F; Greco, F; Costantino, S

    2004-09-01

    Benign paroxysmal positional vertigo (BPPV) has been recognized as the most common vestibular disorder; it is a term coined in 1952 by Dix and Hallpike, and it is most commonly used to describe a disease with a characteristic clinical presentation believed to be caused by free-floating particles leaving the macula and entering one of the semicircular canals, usually the posterior one, more rarely the horizontal or superior ones. A lot of studies showed as the prevalence is higher in females than in males with a ratio of 2:1; furthermore, prevalence increases with the age: the mean age at onset is 54 years, with a range of 11 to 84 years. The most important clinical manifestations of BPPV are: vertigo, lightheadedness, dysequilibrium and sometimes nausea, vomiting, pallor and sweating. The diagnosis of BPPV is very simple through the Dix-Hallpike test or the diagnostic Semont's maneuver; the increasing information about the BPPV's pathogenesis has led most authors to consider the rehabilitative therapy, and in particular the so-called Semont's "liberatory" maneuver, as the first choice treatment of BPPV, in relation to its quickness and efficacy. In this treatment the debris are moved from the posterior semicircular canal to another location within the vestibular labyrinth. In our review we consider the possible pathogenesis of this disease and the best therapies, like repositioning maneuvers, in a patient affected by BPPV.

  16. Benign cranial mediastinal lesions in three cats.

    PubMed

    Malik, R; Gabor, L; Hunt, G B; Church, D B; Barrs, V R; Churcher, R; Dixon, R T; Huxley, C; Canfield, P J

    1997-03-01

    Cranial mediastinal lesions were detected in three cats, associated with respiratory impairment (case one), spontaneous pneumothorax (case two) and myasthenia gravis (case three), respectively. On gross and histological examination, the first case was considered either a lymphangioma or a branchial cystic mass of the thymic region of the mediastinum; a cystic lesion was suggested by sonographic detection of multiple anechoic cavitations within a circumscribed mass, while fine needle aspiration cytology excluded lymphosarcoma. The second case was diagnosed histologically as a cystic thymoma, but the third case was not examined microscopically. The masses were amenable to surgical excision in the first two cats, while this proved unnecessary in the third case because of resolution following treatment with dexamethasone. Corticosteroid responsiveness was unhelpful in distinguishing between these benign lesions and lymphosarcoma, as in two cases there was a partial or complete response to dosing with prednisolone or dexamethasone. These cases are presented to emphasise that conditions other than lymphosarcoma can produce cranial mediastinal lesions in cats, and that the prognosis for surgical treatment of lymphangiomas, multilocular thymic cysts and cystic thymomas can be excellent.

  17. [Minimally Invasive Treatment of Esophageal Benign Diseases].

    PubMed

    Inoue, Haruhiro

    2016-07-01

    As a minimally invasive treatment of esophageal achalasia per-oral endoscopic myotomy( POEM) was developed in 2008. More than 1,100 cases of achalasia-related diseases received POEM. Success rate of the procedure was more than 95%(Eckerdt score improvement 3 points and more). No serious( Clavian-Dindo classification III b and more) complication was experienced. These results suggest that POEM becomes a standard minimally invasive treatment for achalasia-related diseases. As an off-shoot of POEM submucosal tumor removal through submucosal tunnel (per-oral endoscopic tumor resection:POET) was developed and safely performed. Best indication of POET is less than 5 cm esophageal leiomyoma. A novel endoscopic treatment of gastroesophageal reflux disease (GERD) was developed. Anti-reflux mucosectomy( ARMS) is nearly circumferential mucosal reduction of gastric cardia mucosa. ARMS is performed in 56 consecutive cases of refractory GERD. No major complications were encountered and excellent clinical results. Best indication of ARMS is a refractory GERD without long sliding hernia. Longest follow-up case is more than 10 years. Minimally invasive treatments for esophageal benign diseases are currently performed by therapeutic endoscopy.

  18. Clinical Investigation of Benign Asbestos Pleural Effusion

    PubMed Central

    Fujimoto, Nobukazu; Gemba, Kenichi; Aoe, Keisuke; Kato, Katsuya; Yokoyama, Takako; Usami, Ikuji; Onishi, Kazuo; Mizuhashi, Keiichi; Yusa, Toshikazu; Kishimoto, Takumi

    2015-01-01

    There is no detailed information about benign asbestos pleural effusion (BAPE). The aim of the study was to clarify the clinical features of BAPE. The criteria of enrolled patients were as follows: (1) history of asbestos exposure; (2) presence of pleural effusion determined by chest X-ray, CT, and thoracentesis; and (3) the absence of other causes of effusion. Clinical information was retrospectively analysed and the radiological images were reviewed. There were 110 BAPE patients between 1991 and 2012. All were males and the median age at diagnosis was 74 years. The median duration of asbestos exposure and period of latency for disease onset of BAPE were 31 and 48 years, respectively. Mean values of hyaluronic acid, adenosine deaminase, and carcinoembryonic antigen in the pleural fluid were 39,840 ng/mL, 23.9 IU/L, and 1.8 ng/mL, respectively. Pleural plaques were detected in 98 cases (89.1%). Asbestosis was present in 6 (5.5%) cases, rounded atelectasis was detected in 41 (37.3%) cases, and diffuse pleural thickening (DPT) was detected in 30 (27.3%) cases. One case developed lung cancer (LC) before and after BAPE. None of the cases developed malignant pleural mesothelioma (MPM) during the follow-up. PMID:26689234

  19. Searching for "environmentally-benign" antifouling biocides.

    PubMed

    Cui, Yan Ting; Teo, Serena L M; Leong, Wai; Chai, Christina L L

    2014-05-26

    As the result of the ecological impacts from the use of tributyltins (TBT) in shipping, environmental legislation for the registration of chemicals for use in the environment has grown to a monumental challenge requiring product dossiers to include information on the environmental fate and behavior of any chemicals. Specifically, persistence, bioaccumulation and toxicity, collectively known as PBT, are properties of concern in the assessment of chemicals. However, existing measurements of PBT properties are a cumbersome and expensive process, and thus not applied in the early stages of the product discovery and development. Inexpensive methods for preliminary PBT screening would minimize risks arising with the subsequent registration of products. In this article, we evaluated the PBT properties of compounds reported to possess anti-fouling properties using QSAR (quantitative structure-activity relationship) prediction programs such as BIOWIN™ (a biodegradation probability program), KOWWIN™ (log octanol-water partition coefficient calculation program) and ECOSAR™ (Ecological Structure Activity Relationship Programme). The analyses identified some small (Mr < 400) synthetic and natural products as potential candidates for environmentally benign biocides. We aim to demonstrate that while these methods of estimation have limitations, when applied with discretion, they are powerful tools useful in the early stages of research for compound selection for further development as anti-foulants.

  20. Emerging drug therapies for benign prostatic hyperplasia.

    PubMed

    Bullock, Travis L; Andriole, Gerald L

    2006-03-01

    Benign prostatic hyperplasia (BPH) is the nonmalignant enlargement of the prostate gland caused by increases in number of both epithelial and stromal cells. Clinically, BPH leads to voiding dysfunction, which is most often referred to as lower urinary tract symptoms (LUTS). Historically, the only treatments for LUTS due to BPH were watchful waiting or surgery (transurethral or open prostatectomy). However, over the last 20 years medical therapy has taken a prominent role in the management of BPH. Current medical treatments for BPH include alpha-adrenergic receptor antagonists, inhibitors of the 5-alpha reductase enzyme and various phytotherapies. These agents are generally effective and safe; however, many patients are unable to tolerate the side effects or are refractory to medical management and require surgery. In light of this, many potential new therapies for the treatment of BPH are under development. Some represent a variation of current treatments, whereas others target novel molecular pathways within the prostate. The aim of this review is to examine current pharmacotherapies as well as to highlight emerging drugs that may improve our treatment of patients with LUTS secondary to BPH.

  1. Clinical Investigation of Benign Asbestos Pleural Effusion.

    PubMed

    Fujimoto, Nobukazu; Gemba, Kenichi; Aoe, Keisuke; Kato, Katsuya; Yokoyama, Takako; Usami, Ikuji; Onishi, Kazuo; Mizuhashi, Keiichi; Yusa, Toshikazu; Kishimoto, Takumi

    2015-01-01

    There is no detailed information about benign asbestos pleural effusion (BAPE). The aim of the study was to clarify the clinical features of BAPE. The criteria of enrolled patients were as follows: (1) history of asbestos exposure; (2) presence of pleural effusion determined by chest X-ray, CT, and thoracentesis; and (3) the absence of other causes of effusion. Clinical information was retrospectively analysed and the radiological images were reviewed. There were 110 BAPE patients between 1991 and 2012. All were males and the median age at diagnosis was 74 years. The median duration of asbestos exposure and period of latency for disease onset of BAPE were 31 and 48 years, respectively. Mean values of hyaluronic acid, adenosine deaminase, and carcinoembryonic antigen in the pleural fluid were 39,840 ng/mL, 23.9 IU/L, and 1.8 ng/mL, respectively. Pleural plaques were detected in 98 cases (89.1%). Asbestosis was present in 6 (5.5%) cases, rounded atelectasis was detected in 41 (37.3%) cases, and diffuse pleural thickening (DPT) was detected in 30 (27.3%) cases. One case developed lung cancer (LC) before and after BAPE. None of the cases developed malignant pleural mesothelioma (MPM) during the follow-up.

  2. Dutasteride/tamsulosin: in benign prostatic hyperplasia.

    PubMed

    Keating, Gillian M

    2012-05-01

    The 5α-reductase inhibitor dutasteride and the α(1)-adrenergic receptor antagonist tamsulosin are available as a fixed-dose combination for use in men with symptomatic benign prostatic hyperplasia (BPH) and an enlarged prostate. Dutasteride 0.5 mg/day plus tamsulosin 0.4 mg/day improved lower urinary tract symptoms (LUTS) to a significantly greater extent than dutasteride or tamsulosin alone in men with BPH, moderate to severe LUTS and an increased risk of disease progression, according to the results of the randomized, double-blind, multinational CombAT trial. The mean change from baseline in the total International Prostate Symptom Score was significantly greater with dutasteride plus tamsulosin than with dutasteride or tamsulosin alone after 2 years (primary endpoint) and 4 years of therapy. After 4 years' therapy in the CombAT trial, the time to first acute urinary retention or BPH-related surgery (primary endpoint) significantly favoured men with symptomatic BPH who were receiving dutasteride plus tamsulosin versus those receiving tamsulosin alone, with no significant difference between recipients of dutasteride plus tamsulosin and recipients of dutasteride alone. In the CombAT trial, health-related quality of life and treatment satisfaction were improved to a significantly greater extent with dutasteride plus tamsulosin than with dutasteride or tamsulosin alone. Combination therapy with oral dutasteride plus tamsulosin was generally well tolerated in patients with symptomatic BPH in the CombAT trial.

  3. Biphasic versus monophasic shock waveform for conversion of atrial fibrillation: the results of an international randomized, double-blind multicenter trial.

    PubMed

    Page, Richard L; Kerber, Richard E; Russell, James K; Trouton, Tom; Waktare, Johan; Gallik, Donna; Olgin, Jeff E; Ricard, Philippe; Dalzell, Gavin W; Reddy, Ramakota; Lazzara, Ralph; Lee, Kerry; Carlson, Mark; Halperin, Blair; Bardy, Gust H

    2002-06-19

    This study compared a biphasic waveform with a conventional monophasic waveform for cardioversion of atrial fibrillation (AF). Biphasic shock waveforms have been demonstrated to be superior to monophasic shocks for termination of ventricular fibrillation, but data regarding biphasic shocks for conversion of AF are still emerging. In an international, multicenter, randomized, double-blind clinical trial, we compared the effectiveness of damped sine wave monophasic versus impedance-compensated truncated exponential biphasic shocks for the cardioversion of AF. Patients received up to five shocks, as necessary for conversion: 100 J, 150 J, 200 J, a fourth shock at maximum output for the initial waveform (200 J biphasic, 360 J monophasic) and a final cross-over shock at maximum output of the alternate waveform. Analysis included 107 monophasic and 96 biphasic patients. The success rate was higher for biphasic than for monophasic shocks at each of the three shared energy levels (100 J: 60% vs. 22%, p < 0.0001; 150 J: 77% vs. 44%, p < 0.0001; 200 J: 90% vs. 53%, p < 0.0001). Through four shocks, at a maximum of 200 J, biphasic performance was similar to monophasic performance at 360 J (91% vs. 85%, p = 0.29). Biphasic patients required fewer shocks (1.7 +/- 1.0 vs. 2.8 +/- 1.2, p < 0.0001) and lower total energy delivered (217 +/- 176 J vs. 548 +/- 331 J, p < 0.0001). The biphasic shock waveform was also associated with a lower frequency of dermal injury (17% vs. 41%, p < 0.0001). For the cardioversion of AF, a biphasic shock waveform has greater efficacy, requires fewer shocks and lower delivered energy, and results in less dermal injury than a monophasic shock waveform.

  4. Fluorocarbon compatibilized gold-silica nanocomposites for recyclable regioselective hydroamination of alkynes in a fluorous biphasic system

    NASA Astrophysics Data System (ADS)

    Merican, Zulkifli; Vu, Bao Khanh; Solovyeva, Vera A.; Rodionov, Valentin O.; Khe, Cheng Seong; Rajalingam, Sokkalingam; Vasant, Pandian

    2016-11-01

    The synthesis and characterization of the mesoporous silica-supported gold (Au@mSiO2) nanoparticles compatibilized with the outer shelled superhydrophobic fluorous (F) "tails" was described. The concept of fluorous biphasic separation was applied in the recycling of the synthesized fluorous material during hydroamination reactions of various alkynes. In the presence of perfluoromethylcyclohexane and heptane as a biphasic liquid system, the F-Au@mSiO2 was found to be a highly active catalyst for hydroamination of various alkynes with anilines, and a near quantitative yield for an imine product and produced a relatively minimal formation of a corresponding hydrolyzed ketone by-product. If perfluoromethylcyclohexane and heptane was used as a biphasic solvent, hydroamination at a lower reaction temperature can also be realized leading to an improved recyclability and conversion.

  5. Invariance of the magnetic behavior and AMI in ferromagnetic biphase films with distinct non-magnetic metallic spacers

    NASA Astrophysics Data System (ADS)

    Silva, E. F.; Gamino, M.; Andrade, A. M. H. de; Vázquez, M.; Correa, M. A.; Bohn, F.

    2017-02-01

    We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices.

  6. Fabrication of Biphase BiVO4 Particles with Enhanced Photocatalytic Performance via a Surfactant-Free Hydrothermal Route

    NASA Astrophysics Data System (ADS)

    Qian, Hongzhi; Lai, Min; Huang, Xiaogu; Wang, Wei; Xu, Chaoqi; Yong, Haibo; Wen, Yan; Zhou, Yingjie

    2016-04-01

    Biphase bismuth vanadate (BiVO4) particles have been synthesized using a surfactant-free hydrothermal strategy. Biphase BiVO4 were formed at pH=3, 5 and 7 with a bandgap between 2.28eV and 2.86eV, which are those of monoclinic and tetragonal phases, respectively. Photocatalytic tests on the degradation of rhodamine B (RhB) under visible-light irradiation showed that biphase BiVO4 with both monoclinic and tetragonal structures synthesized at pH=3 achieved enhanced photocatalytic performance in comparison with pure monoclinic and tetragonal phases, which was attributed to the heterostructures leading to low recombination rate of electron-hole pairs.

  7. Benign paroxysmal torticollis of infancy: An underdiagnosed condition.

    PubMed

    Hadjipanayis, Adamos; Efstathiou, Elisavet; Neubauer, David

    2015-07-01

    Benign paroxysmal torticollis is probably an under-diagnosed condition of infancy. It is a self-limiting disorder characterised by periods of unusual, sustained posture of the head and neck, during which the head tilts to one side. Episodes are often accompanied by marked autonomic features, irritability, ataxia, apathy and drowsiness. They last several hours to a few days and are often recurring every few weeks. They subside within the pre-school years; however, during later childhood, there is a tendency to develop migraine. Three cases of benign paroxysmal torticollis are presented and are compared with cases in the literature. A telephone survey has been conducted to determine what is the general awareness of paediatricians of this condition in Cyprus. Eighty-two paediatricians were randomly selected out of 235 paediatricians. All of them agreed to participate. Our cases revealed that benign paroxysmal torticollis may coexist with other problems during infancy. The telephone survey showed that only two out of eighty-two (2.4%) of the paediatricians are aware of the condition, and none of them was confident regarding the management. Our telephone survey clearly shows that Cypriot paediatricians are not familiar with benign paroxysmal torticollis in infancy which is a benign, self-limiting disorder. It is essential to recognise the condition and to reassure parents of its benign course and not to be misdiagnosed for other disorders, such as epileptic seizures. We have shown again that benign paroxysmal torticollis in infancy may coexist with motor delay and hearing problems.

  8. Childhood absence epilepsy in patients with benign focal epileptiform discharges.

    PubMed

    Sarkis, Rani A; Loddenkemper, Tobias; Burgess, Richard C; Wyllie, Elaine

    2009-12-01

    Few reports are available of ictal recordings in patients with benign focal epileptiform discharges. The study objective was to estimate the frequency of such recordings and to describe their clinical and electrophysiologic presentation. We performed a retrospective chart review of all patients undergoing routine electroencephalography (EEG) with video during a 10-year period. Among 214 patients with benign focal epileptiform discharges, 5 patients were identified with recorded EEG seizures (2.3%). Epilepsy syndromes included one case of benign focal epilepsy of childhood, three cases of childhood absence epilepsy, and in one case the patient presented with both. Only 1 of the 214 patients (0.4%) had a seizure characteristic of benign focal epilepsy of childhood. A literature review revealed the coexistence of childhood absence and benign focal epilepsy of childhood or benign focal epileptiform discharges within the same patient. These findings suggest that benign focal epilepsy of childhood seizures are rarely recorded during routine EEG, probably because seizures occur during the early morning part of the sleep cycle, which may differ from the brief nap during routine EEG. There was concurrence of generalized spike and wave discharges in these patients. It is unclear whether this is related to a common pathophysiologic factor.

  9. Switching from biphasic human insulin to biphasic insulin aspart 30 in type 2 diabetes: results from the ASEAN subgroup of the A₁chieve study.

    PubMed

    Hussein, Zanariah; Lim-Abrahan, Mary Anne; Jain, Anand B; Goh, Su Yen; Soewondo, Pradana

    2013-04-01

    To evaluate the safety and effectiveness of biphasic insulin aspart 30 (BIAsp 30) in ASEAN type 2 diabetes (T2D) patients switched from biphasic human insulin (BHI) in the non-interventional 24-week A₁chieve study. Indonesian, Malaysian, Filipino and Singaporean patients switched from BHI to BIAsp 30 at their physicians' discretion were included. The incidence of serious adverse drug reactions (SADRs), including major hypoglycaemia was the primary endpoint. Changes in hypoglycaemia, glycated haemoglobin A1c (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPPG), lipids, body weight and systolic blood pressure were also evaluated. Quality of life (QoL) was measured using the EQ-5D questionnaire. For the 465 patients included (mean ± SD age: 56 ± 10.3 years, diabetes duration: 9.7 ± 7.1 years, baseline HbA1c: 9.4 ± 1.8%), the mean pre-study BHI dose was 0.62 ± 0.28 IU/kg and 63.4% were dosing BHI twice daily (bid). The mean baseline BIAsp 30 dose was 0.65 ± 0.27 U/kg, titrated up to 0.71 ± 0.28 U/kg over 24 weeks, and most patients continued bid dosing. No SADRs or major hypoglycaemic episodes were reported. The proportion of patients reporting overall hypoglycaemia decreased significantly from 10.8% at baseline to 3.4% at Week 24 (p < 0.0001). Significant improvements in glycaemic control were noted (HbA1c: -1.4 ± 1.7%, FPG: -56.7 ± 72.5 mg/dL, post-breakfast PPPG: -84.8 ± 82.8 mg/dL, p < 0.001). Mean QoL improved by +6.6 ± 14.6 points (p < 0.001). BIAsp 30 was well-tolerated and significantly increased glycaemic control in this ASEAN subgroup poorly controlled on BHI. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Accounting for phase drifts in SSVEP-based BCIs by means of biphasic stimulation.

    PubMed

    Wu, Hung-Yi; Lee, Po-Lei; Chang, Hsiang-Chih; Hsieh, Jen-Chuen

    2011-05-01

    This study proposes a novel biphasic stimulation technique to solve the issue of phase drifts in steady-state visual evoked potential (SSVEPs) in phase-tagged systems. Phase calibration was embedded in stimulus sequences using a biphasic flicker, which is driven by a sequence with alternating reference and phase-shift states. Nine subjects were recruited to participate in off-line and online tests. Signals were bandpass filtered and segmented by trigger signals into reference and phase-shift epochs. Frequency components of SSVEP in the reference and phase-shift epochs were extracted using the Fourier method with a 50% overlapped sliding window. The real and imaginary parts of the SSVEP frequency components were organized into complex vectors in each epoch. Hotelling's t-square test was used to determine the significances of nonzero mean vectors. The rejection of noisy data segments and the validation of gaze detections were made based on p values. The phase difference between the valid mean vectors of reference and phase-shift epochs was used to identify user's gazed targets in this system. Data showed an average information transfer rate of 44.55 and 38.21 bits/min in off-line and online tests, respectively.

  11. Acute exercise induces biphasic increase in respiratory mRNA in skeletal muscle

    SciTech Connect

    Ikeda, Shin-ichi; Kizaki, Takako; Haga, Shukoh; Ohno, Hideki; Takemasa, Tohru

    2008-04-04

    Peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) promotes the expression of oxidative enzymes in skeletal muscle. We hypothesized that activation of the p38 MAPK (mitogen-activated protein kinase) in response to exercise was associated with exercise-induced PGC-1{alpha} and respiratory enzymes expression and aimed to demonstrate this under the physiological level. We subjected mice to a single bout of treadmill running and found that the exercise induced a biphasic increase in the expression of respiratory enzymes mRNA. The second phase of the increase was accompanied by an increase in PGC-1{alpha} protein, but the other was not. Administration of SB203580 (SB), an inhibitor of p38 MAPK, suppressed the increase in PGC-1{alpha} expression and respiratory enzymes mRNA in both phases. These data suggest that p38 MAPK is associated with the exercise-induced expression of PGC-1{alpha} and biphasic increase in respiratory enzyme mRNAs in mouse skeletal muscle under physiological conditions.

  12. Biphasic recruitment of microchimeric fetal mesenchymal cells in fibrosis following acute kidney injury.

    PubMed

    Roy, Edwige; Seppanen, Elke; Ellis, Rebecca; Lee, Eddy S; Khosrotehrani, Kiarash; Khosroterani, Kiarash; Fisk, Nicholas M; Bou-Gharios, George

    2014-03-01

    Fetal microchimeric cells (FMCs) enter the maternal circulation and persist in tissue for decades. They have capacity to home to injured maternal tissue and differentiate along that tissue's lineage. This raises the question of the origin(s) of cells transferred to the mother during pregnancy. FMCs with a mesenchymal phenotype have been documented in several studies, which makes mesenchymal stem cells an attractive explanation for their broad plasticity. Here we assessed the recruitment and mesenchymal lineage contribution of FMCs in response to acute kidney fibrosis induced by aristolochic acid injection. Serial in vivo bioluminescence imaging revealed a biphasic recruitment of active collagen-producing FMCs during the repair process of injured kidney in post-partum wild-type mothers that had delivered transgenic pups expressing luciferase under the collagen type I-promoter. The presence of FMCs long-term post injury (day 60) was associated with profibrotic molecules (TGF-β/CTGF), serum urea levels, and collagen deposition. Immunostaining confirmed FMCs at short term (day 15) using post-partum wild-type mothers that had delivered green fluorescent protein-positive pups and suggested a mainly hematopoietic phenotype. We conclude that there is biphasic recruitment to, and activity of, FMCs at the injury site. Moreover, we identified five types of FMC, implicating them all in the reparative process at different stages of induced renal interstitial fibrosis.

  13. Bioabsorbable zinc ion induced biphasic cellular responses in vascular smooth muscle cells

    PubMed Central

    Ma, Jun; Zhao, Nan; Zhu, Donghui

    2016-01-01

    Bioabsorbable metal zinc (Zn) is a promising new generation of implantable scaffold for cardiovascular and orthopedic applications. In cardiovascular stent applications, zinc ion (Zn2+) will be gradually released into the surrounding vascular tissues from such Zn-containing scaffolds after implantation. However, the interactions between vascular cells and Zn2+ are still largely unknown. We explored the short-term effects of extracellular Zn2+ on human smooth muscle cells (SMCs) up to 24 h, and an interesting biphasic effect of Zn2+ was observed. Lower concentrations (<80 μM) of Zn2+ had no adverse effects on cell viability but promoted cell adhesion, cell spreading, cell proliferation, cell migration, and enhanced the expression of F-actin and vinculin. Cells treated with such lower concentrations of Zn2+ displayed an elongated shape compared to controls without any treatment. In contrast, cells treated with higher Zn2+ concentrations (80–120 μM) had opposite cellular responses and behaviors. Gene expression profiles revealed that the most affected functional genes were related to angiogenesis, inflammation, cell adhesion, vessel tone, and platelet aggregation. Results indicated that Zn has interesting concentration-dependent biphasic effects on SMCs with low concentrations being beneficial to cellular functions. PMID:27248371

  14. Prostaglandin E2 (PGE2) Exerts Biphasic Effects on Human Tendon Stem Cells

    PubMed Central

    Zhang, Jianying; Wang, James H-C.

    2014-01-01

    Prostaglandin E2 (PGE2) has been reported to exert different effects on tissues at low and high levels. In the present study, cell culture experiments were performed to determine the potential biphasic effects of PGE2 on human tendon stem/progenitor cells (hTSCs). After treatment with PGE2, hTSC proliferation, stemness, and differentiation were analyzed. We found that high concentrations of PGE2 (>1 ng/ml) decreased cell proliferation and induced non-tenocyte differentiation. However, at lower concentrations (<1 ng/ml), PGE2 markedly enhanced hTSC proliferation. The expression levels of stem cell marker genes, specifically SSEA-4 and Stro-1, were more extensive in hTSCs treated with low concentrations of PGE2 than in cells treated with high levels of PGE2. Moreover, high levels of PGE2 induced hTSCs to differentiate aberrantly into non-tenocytes, which was evident by the high levels of PPARγ, collagen type II, and osteocalcin expression in hTSCs treated with PGE2 at concentrations >1 ng/ml. The findings of this study reveal that PGE2 can exhibit biphasic effects on hTSCs, indicating that while high PGE2 concentrations may be detrimental to tendons, low levels of PGE2 may play a vital role in the maintenance of tendon homeostasis in vivo. PMID:24504456

  15. Cranial muscle development in frogs with different developmental modes: direct development versus biphasic development.

    PubMed

    Ziermann, Janine M; Diogo, Rui

    2014-04-01

    Normal development in anurans includes a free swimming larva that goes through metamorphosis to develop into the adult frog. We have investigated cranial muscle development and adult cranial muscle morphology in three different anuran species. Xenopus laevis is obligate aquatic throughout lifetime, Rana(Lithobates) pipiens has an aquatic larvae and a terrestrial adult form, and Eleutherodactylus coqui has direct developing juveniles that hatch from eggs deposited on leaves (terrestrial). The adult morphology shows hardly any differences between the investigated species. Cranial muscle development of E. coqui shows many similarities and only few differences to the development of Rana (Lithobates) and Xenopus. The differences are missing muscles of the branchial arches (which disappear during metamorphosis of biphasic anurans) and a few heterochronic changes. The development of the mandibular arch (adductor mandibulae) and hyoid arch (depressor mandibulae) muscles is similar to that observed in Xenopus and Rana (Lithobates), although the first appearance of these muscles displays a midmetamorphic pattern in E. coqui. We show that the mix of characters observed in E. coqui indicates that the larval stage is not completely lost even without a free swimming larval stage. Cryptic metamorphosis is the process in which morphological changes in the larva/embryo take place that are not as obvious as in normal metamorphosing anurans with a clear biphasic lifestyle. During cryptic metamorphosis, a normal adult frog develops, indicating that the majority of developmental mechanisms towards the functional adult cranial muscles are preserved.

  16. Primary Esophageal Extranasal NK/T Cell Lymphoma With Biphasic Morphology

    PubMed Central

    Ye, Zi-Yin; Cao, Qing-Hua; Liu, Fang; Lu, Xiao-Fang; Li, Shu-Rong; Li, Chang-Zhao; Chen, Shao-Hong

    2015-01-01

    Abstract We report a case of esophageal extranasal NK/T cell lymphoma with biphasic morphologic features revealed by a deep large piecemeal biopsy. A 40-year-old man present with pharyngalgia, dysphagia, recurrent fever, and 5-kg weight loss for 8 months. Endoscopy demonstrated progressing longitudinal ulcers and mucosal bridges along the esophagus. The first and second biopsies obtained superficial mucosa with scattered bland-looking small lymphocytes. A subsequent large piecemeal snare abscission for biopsy showed atypical lymphoid cells infiltrating into the deep lamina propria and muscularis mucosae, whereas the superficial lamina propria was highly edematous with scant small lymphocytes. Immunohistochemical studies confirmed that both underlying atypical cells and superficial small lymphocytes were neoplastic, sharing an identical immunophenotype: positive for CD2, CD3, CD43, CD8, CD56, TIA-1 and granzyme B. Epstein-Barr virus–encoded small RNAs were found in both cells. The histologic findings were diagnostic of primary esophageal extranasal NK/T cell lymphoma. However, the patient developed bone marrow depression during chemotherapy and died of massive cerebral hemorrhage after the first cycle of chemotherapy. Primary esophageal extranodal NK/T cell lymphoma nasal type is extremely rare. We show the biphasic morphology of this disease, which highlights the importance of deep biopsy for accurate diagnosis. PMID:26181557

  17. Occurrence of amylose-lipid complexes in teff and maize starch biphasic pastes.

    PubMed

    Wokadala, Obiro Cuthbert; Ray, Suprakas Sinha; Emmambux, Mohammad Naushad

    2012-09-01

    The occurrence of amylose-lipid complexes was determined in maize and teff starch biphasic pastes i.e. peak viscosity pastes at short and prolonged pasting times. Maize and teff starches were pasted for 11.5 and 130 min with or without added stearic acid followed by thermo-stable alpha-amylase hydrolysis in a rapid visco-analyzer. X-ray diffraction analysis of pastes before and residues after hydrolysis showed crystalline V-amylose diffraction patterns for the starches pasted for a prolonged time with added stearic acid while less distinct V-amylose patterns with non-complexed stearic acid peaks were observed with a short pasting time. Differential scanning calorimetry of pastes before and residues after paste hydrolysis showed that Type I amylose-lipid complexes were formed after pasting for the short duration with added stearic acid, while Type II complexes are formed after pasting for the prolonged time. The present research provides evidence that amylose-lipid complexes play an important role in starch biphasic pasting.

  18. Biphasic mode of antibacterial action of aminoglycoside antibiotics-loaded elastic hydroxyapatite-glucan composite.

    PubMed

    Belcarz, Anna; Zima, Aneta; Ginalska, Grażyna

    2013-09-15

    Following the quest for new composite materials for bone tissue engineering, a novel elastic hydroxyapatite-glucan composite loaded with two aminoglycoside antibiotics was prepared. The porosity of the composite and the drug release profiles in closed-loop and semi-open systems were tested. The antibacterial activity of the drug was estimated against two Gram-positive and two Gram-negative bacterial strains causing orthopedic infections. It was found that the loaded antibiotic acted in a biphasic mode. The majority of the drug was released within 48-119 h in a pore-dependent manner and inhibited the bacterial growth in the culture medium. However, a small residual amount of the drug was bound to the composite microstructure via ionic interactions and acted as a short-lived barrier against bacterial adhesion to the composite, although the surrounding medium was no longer protected against bacterial infection. Sub-inhibitory concentrations of the released drug were observed in the medium only during the last two days of the experiment (minimized risk of occurrence of drug-resistant strains). Thus the novel drug-loaded elastic hydroxyapatite-glucan composite, demonstrating a biphasic mode of antibacterial action, may be recommended for antibiotic prophylaxis in bone substitute implantation, with less emphasis on the treatment of bone infections.

  19. A biphasic approach for the study of lift generation in soft porous media

    NASA Astrophysics Data System (ADS)

    Wu, Qianhong; Santhanam, Sridhar; Nathan, Rungun; Wang, Qiuyun

    2017-04-01

    Lift generation in highly compressible porous media under rapid compression continues to be an important topic in porous media flow. Although significant progress has been made, how to model different lifting forces during the compression process remains unclear. This is mainly because the input parameters of the existing theoretical studies, including the Darcy permeability of the porous media and the viscous damping coefficient of its solid phase, were manually adjusted so as to match the experimental data. In the current paper, we report a biphasic approach to experimentally and theoretically treat this limitation. Synthetic fibrous porous materials, whose permeability were precisely measured, were subsequently exposed to sudden impacts using a porous-walled cylinder-piston apparatus. The obtained time-dependent compression of the porous media, along with the permeability data, was applied in two different theoretical models to predict the pore pressure generation, a plug flow model and a consolidation model [Q. Wu et al., J. Fluid Mech. 542, 281 (2005a)]. Comparison between the theory and the experiments on the pore pressure distribution proved the validity of the consolidation model. Furthermore, a viscoelastic model, containing a nonlinear spring in conjunction with a linear viscoelastic generalized Maxwell mechanical module, was developed to characterize the solid phase lifting force. The model matched the experimental data very well. The paper presented herein, as one of the series studies on this topic, provides an important biphasic approach to characterize different forces that contribute to the lift generation in a soft porous medium under rapid compression.

  20. New resource for the computation of cartilage biphasic material properties with the interpolant response surface method

    PubMed Central

    Keenan, Kathryn E.; Kourtis, Lampros C.; Besier, Thor F.; Lindsey, Derek P.; Gold, Garry E.; Delp, Scott L.; Beaupre, Gary S.

    2009-01-01

    Cartilage material properties are important for understanding joint function and diseases, but can be challenging to obtain. Three biphasic material properties (aggregate modulus, Poisson's ratio and permeability) can be determined using an analytical or finite element model combined with optimisation to find the material properties values that best reproduce an experimental creep curve. The purpose of this study was to develop an easy-to-use resource to determine biphasic cartilage material properties. A Cartilage Interpolant Response Surface was generated from interpolation of finite element simulations of creep indentation tests. Creep indentation tests were performed on five sites across a tibial plateau. A least-squares residual search of the Cartilage Interpolant Response Surface resulted in a best-fit curve for each experimental condition with corresponding material properties. These sites provided a representative range of aggregate moduli (0.48–1.58 MPa), Poisson's ratio (0.00–0.05) and permeability (1.7 × 10−15−5.4 × 10−15 m4/N s) values found in human cartilage. PMID:19675978

  1. A Physicochemically Optimized and Neuroconductive Biphasic Nerve Guidance Conduit for Peripheral Nerve Repair.

    PubMed

    Ryan, Alan J; Lackington, William A; Hibbitts, Alan J; Matheson, Austyn; Alekseeva, Tijna; Stejskalova, Anna; Roche, Phoebe; O'Brien, Fergal J

    2017-10-04

    Clinically available hollow nerve guidance conduits (NGCs) have had limited success in treating large peripheral nerve injuries. This study aims to develop a biphasic NGC combining a physicochemically optimized collagen outer conduit to bridge the transected nerve, and a neuroconductive hyaluronic acid-based luminal filler to support regeneration. The outer conduit is mechanically optimized by manipulating crosslinking and collagen density, allowing the engineering of a high wall permeability to mitigate the risk of neuroma formation, while also maintaining physiologically relevant stiffness and enzymatic degradation tuned to coincide with regeneration rates. Freeze-drying is used to seamlessly integrate the luminal filler into the conduit, creating a longitudinally aligned pore microarchitecture. The luminal stiffness is modulated to support Schwann cells, with laminin incorporation further enhancing bioactivity by improving cell attachment and metabolic activity. Additionally, this biphasic NGC is shown to support neurogenesis and gliogenesis of neural progenitor cells and axonal outgrowth from dorsal root ganglia. These findings highlight the paradigm that a successful NGC requires the concerted optimization of both a mechanical support phase capable of bridging a nerve defect and a neuroconductive phase with an architecture capable of supporting both Schwann cells and neurons in order to achieve functional regenerative outcome. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Fabrication of nano structural biphasic materials from phosphogypsum waste and their in vitro applications

    SciTech Connect

    Mohamed, Khaled R.; Mousa, Sahar M.; El Bassyouni, Gehan T.

    2014-02-01

    Graphical abstract: (a) Schema of the process, (b) TEM of nano particles of biphasic materials and (c) SEM of post-immersion. - Highlights: • Ratio of HA and β-TCP phases were controlled by thermal treatment. • HA partially decomposed into β-TCP with other bioactive phases. • Calcined HA at 900 °C is the best for the bioactivity behavior. - Abstract: In this study, a novel process of preparing biphasic calcium phosphate (BCP) is proposed. Also its bioactivity for the utilization of the prepared BCP as a biomaterial is studied. A mixture of calcium hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) could be obtained by thermal treatment of HAP which was previously prepared from phosphogypsum (PG) waste. The chemical and phase composition, morphology and particle size of prepared samples was characterized by X-ray diffraction (XRD), Infrared spectroscopy (IR), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The bioactivity was investigated by soaking of the calcined samples in simulated body fluid (SBF). Results confirmed that the calcination temperatures played an important role in the formation of calcium phosphate (CP) materials. XRD results indicated that HAP was partially decomposed into β-TCP. The in vitro data confirmed that the calcined HAP forming BCP besides other phases such as pyrophosphate and silica are bioactive materials. Therefore, BCP will be used as good biomaterials for medical applications.

  3. Investigation of biphasic tumor oxygen dynamics induced by hyperoxic gas intervention: the dynamic phantom approach

    NASA Astrophysics Data System (ADS)

    Kim, Jae G.; Liu, Hanli

    2008-01-01

    We have developed dynamic tumor vascular phantoms and utilized them to investigate the biphasic behavior of increases in light absorption, which is directly associated with oxygenated hemoglobin concentration that was observed in vivo from rat breast tumor experiments during carbogen/oxygen inhalation. The experimental setup for the phantom study included a continuous-wave, multichannel, near-infrared spectroscopy (NIRS) system and syringe pumps to drive the simulated blood through the dynamic vascular phantoms. The results from such phantom experiments clearly show that the two time constants observed in tumor oxygenation dynamics in vivo can result from two different perfusion rates or two different blood flow velocities. We provide experimental support for our previous hypothesis: the biphasic tumor hemodynamic feature stems from a well-perfused and poorly perfused region that could be detected with the two time constants of the NIRS signals. With a multichannel approach, noninvasive NIRS measurements may have useful and prognostic values to quantify the therapeutic effects of cancer treatments.

  4. Renal cell carcinoma in kidney allografts: histologic types, including biphasic papillary carcinoma.

    PubMed

    Troxell, Megan L; Higgins, John P

    2016-11-01

    Kidney transplant recipients are at increased risk for malignancy, with about 5% incidence of cancer in native end-stage kidneys. Carcinoma in the renal allograft is far less common. Prior studies have demonstrated a propensity for renal cell carcinomas (RCCs) of papillary subtypes in end-stage kidneys, and perhaps in allograft kidneys, but most allograft studies lack detailed pathologic review and predate the current classification system. We reviewed our experience with renal carcinoma in kidney allografts at 2 academic centers applying the International Society of Urological Pathology classification, informed by immunohistochemistry. The incidence of renal allograft carcinoma was about 0.26% in our population. Of 12 allograft carcinomas, 6 were papillary (50%), 4 were clear cell (33%), 1 was clear cell (tubulo)papillary, and 1 chromophobe. Two of the papillary carcinomas had distinctive biphasic glomeruloid architecture matching the newly named "biphasic squamoid alveolar" pattern and were difficult to classify on core biopsies. The 2 cell types had different immunophenotypes in our hands (eosinophilic cells: RCC-/CK34betaE12+ weight keratin +/cyclin D1+; clear cells: RCC+/cytokeratin high molecular weight negative to weak/cyclin D1-). None of the patients experienced cancer recurrences or metastasis. Our study confirms the predilection for papillary RCCs in kidney allografts and highlights the occurrence of rare morphologic variants. Larger studies are needed with careful pathologic review, which has been lacking in the literature.

  5. Biphasic investigation of contact mechanics in natural human hips during activities.

    PubMed

    Li, Junyan; Hua, Xijin; Jin, Zhongmin; Fisher, John; Wilcox, Ruth K

    2014-06-01

    The aim of this study was to determine the cartilage contact mechanics and the associated fluid pressurisation of the hip joint under eight daily activities, using a three-dimensional finite element hip model with biphasic cartilage layers and generic geometries. Loads with spatial and temporal variations were applied over time and the time-dependent performance of the hip cartilage during walking was also evaluated. It was found that the fluid support ratio was over 90% during the majority of the cycles for all the eight activities. A reduced fluid support ratio was observed for the time at which the contact region slid towards the interior edge of the acetabular cartilage, but these occurred when the absolute level of the peak contact stress was minimal. Over 10 cycles of gait, the peak contact stress and peak fluid pressure remained constant, but a faster process of fluid exudation was observed for the interior edge region of the acetabular cartilage. The results demonstrate the excellent function of the hip cartilage within which the solid matrix is prevented from high levels of stress during activities owing to the load shared by fluid pressurisation. The findings are important in gaining a better understanding of the hip function during daily activities, as well as the pathology of hip degeneration and potential for future interventions. They provide a basis for future subject-specific biphasic investigations of hip performance during activities.

  6. Regulation of the demographic structure in isomorphic biphasic life cycles at the spatial fine scale.

    PubMed

    Vieira, Vasco Manuel Nobre de Carvalho da Silva; Mateus, Marcos Duarte

    2014-01-01

    Isomorphic biphasic algal life cycles often occur in the environment at ploidy abundance ratios (Haploid:Diploid) different from 1. Its spatial variability occurs within populations related to intertidal height and hydrodynamic stress, possibly reflecting the niche partitioning driven by their diverging adaptation to the environment argued necessary for their prevalence (evolutionary stability). Demographic models based in matrix algebra were developed to investigate which vital rates may efficiently generate an H:D variability at a fine spatial resolution. It was also taken into account time variation and type of life strategy. Ploidy dissimilarities in fecundity rates set an H:D spatial structure miss-fitting the ploidy fitness ratio. The same happened with ploidy dissimilarities in ramet growth whenever reproductive output dominated the population demography. Only through ploidy dissimilarities in looping rates (stasis, breakage and clonal growth) did the life cycle respond to a spatially heterogeneous environment efficiently creating a niche partition. Marginal locations were more sensitive than central locations. Related results have been obtained experimentally and numerically for widely different life cycles from the plant and animal kingdoms. Spore dispersal smoothed the effects of ploidy dissimilarities in fertility and enhanced the effects of ploidy dissimilarities looping rates. Ploidy dissimilarities in spore dispersal could also create the necessary niche partition, both over the space and time dimensions, even in spatial homogeneous environments and without the need for conditional differentiation of the ramets. Fine scale spatial variability may be the key for the prevalence of isomorphic biphasic life cycles, which has been neglected so far.

  7. Influence of Biphasic Stimulation on Olfactory Ensheathing Cells for Neuroprosthetic Devices

    PubMed Central

    Hassarati, Rachelle T.; Foster, L. John R.; Green, Rylie A.

    2016-01-01

    The recent success of olfactory ensheathing cell (OEC) assisted regeneration of injured spinal cord has seen a rising interest in the use of these cells in tissue-engineered systems. Previously shown to support neural cell growth through glial scar tissue, OECs have the potential to assist neural network formation in living electrode systems to produce superior neuroprosthetic electrode surfaces. The following study sought to understand the influence of biphasic electrical stimulation (ES), inherent to bionic devices, on cell survival and function, with respect to conventional metallic and developmental conductive hydrogel (CH) coated electrodes. The CH utilized in this study was a biosynthetic hydrogel consisting of methacrylated poly(vinyl-alcohol) (PVA), heparin and gelatin through which poly(3,4-ethylenedioxythiophene) (PEDOT) was electropolymerised. OECs cultured on Pt and CH surfaces were subjected to biphasic ES. Image-based cytometry yielded little significant difference between the viability and cell cycle of OECs cultured on the stimulated and passive samples. The significantly lower voltages measured across the CH electrodes (147 ± 3 mV) compared to the Pt (317 ± 5 mV), had shown to influence a higher percentage of viable cells on CH (91–93%) compared to Pt (78–81%). To determine the functionality of these cells following electrical stimulation, OECs co-cultured with PC12 cells were found to support neural cell differentiation (an indirect measure of neurotrophic factor production) following ES. PMID:27757072

  8. Formation of a fluorous/organic biphasic supramolecular octopus assembly for enhanced porphyrin phosphorescence in air.

    PubMed

    Yang, Chi; Arvapally, Ravi K; Tekarli, Sammer M; Salazar, Gustavo A; Elbjeirami, Oussama; Wang, Xiaoping; Omary, Mohammad A

    2015-04-13

    The trinuclear triangle-shaped system [tris{3,5-bis(heptafluoropropyl)-1,2,4-triazolatosilver(I)}] (1) and the multi-armed square-shaped metalloporphyrin PtOEP or the free porphyrin base H2OEP serve as excellent octopus hosts (OEP=2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine). Coupling of the fluorous/organic molecular octopi 1 and H2OEP or PtOEP by strong quadrupole-quadrupole and metal-π interactions affords the supramolecular assemblies [1⋅PtOEP] or [1⋅H2OEP] (2 a), which feature nanoscopic cavities surrounding the upper triangular and lower square cores. The fluorous/organic biphasic configuration of [1⋅PtOEP] leads to an increase in the phosphorescence of PtOEP under ambient conditions. Guest molecules can be included in the biphasic double-octopus assembly in three different site-selective modes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. New resource for the computation of cartilage biphasic material properties with the interpolant response surface method.

    PubMed

    Keenan, Kathryn E; Kourtis, Lampros C; Besier, Thor F; Lindsey, Derek P; Gold, Garry E; Delp, Scott L; Beaupre, Gary S

    2009-08-01

    Cartilage material properties are important for understanding joint function and diseases, but can be challenging to obtain. Three biphasic material properties (aggregate modulus, Poisson's ratio and permeability) can be determined using an analytical or finite element model combined with optimisation to find the material properties values that best reproduce an experimental creep curve. The purpose of this study was to develop an easy-to-use resource to determine biphasic cartilage material properties. A Cartilage Interpolant Response Surface was generated from interpolation of finite element simulations of creep indentation tests. Creep indentation tests were performed on five sites across a tibial plateau. A least-squares residual search of the Cartilage Interpolant Response Surface resulted in a best-fit curve for each experimental condition with corresponding material properties. These sites provided a representative range of aggregate moduli (0.48-1.58 MPa), Poisson's ratio (0.00-0.05) and permeability (1.7 x 10(- 15)-5.4 x 10(- 15) m(4)/N s) values found in human cartilage. The resource is freely available from https://simtk.org/home/va-squish.

  10. Sterility testing of a total nutrient admixture with a biphasic blood-culture system.

    PubMed

    Murray, P R; Sandrock, M J

    1991-11-01

    The ability of a biphasic blood-culture system to detect microbial contamination of a total nutrient admixture (TNA) was studied. A TNA consisting of amino acids, dextrose, lipid emulsion, electrolytes, and trace elements was prepared under aseptic conditions. Septi-Chek blood-culture bottles were then injected with a TNA sample and with one of various dilutions of five bacterial or fungal suspensions, and an agar slide unit was attached to each bottle. One bottle was injected only with a TNA sample. The bottles were incubated and examined once daily. Each bottle was inverted immediately after inoculation and at each observation time to allow the broth to wash over the agar slide unit. Because the lipid contained in the TNA caused the broth in all bottles to become turbid, it was impossible to determine whether microbial growth was present in the broth. Microbial growth, however, became evident in 24-72 hours on all slide units except the one attached to the bottle that had been injected only with TNA. The Septi-Chek biphasic blood-culture system appears to be useful in evaluating the sterility of TNAs.

  11. Differential Biphasic Transcriptional Host Response Associated with Coevolution of Hemagglutinin Quasispecies of Influenza A Virus

    PubMed Central

    Manchanda, Himanshu; Seidel, Nora; Blaess, Markus F.; Claus, Ralf A.; Linde, Joerg; Slevogt, Hortense; Sauerbrei, Andreas; Guthke, Reinhard; Schmidtke, Michaela

    2016-01-01

    Severe influenza associated with strong symptoms and lung inflammation can be caused by intra-host evolution of quasispecies with aspartic acid or glycine in hemagglutinin position 222 (HA-222D/G; H1 numbering). To gain insights into the dynamics of host response to this coevolution and to identify key mechanisms contributing to copathogenesis, the lung transcriptional response of BALB/c mice infected with an A(H1N1)pdm09 isolate consisting HA-222D/G quasispecies was analyzed from days 1 to 12 post infection (p.i). At day 2 p.i. 968 differentially expressed genes (DEGs) were detected. The DEG number declined to 359 at day 4 and reached 1001 at day 7 p.i. prior to recovery. Interestingly, a biphasic expression profile was shown for the majority of these genes. Cytokine assays confirmed these results on protein level exemplarily for two key inflammatory cytokines, interferon gamma and interleukin 6. Using a reverse engineering strategy, a regulatory network was inferred to hypothetically explain the biphasic pattern for selected DEGs. Known regulatory interactions were extracted by Pathway Studio 9.0 and integrated during network inference. The hypothetic gene regulatory network revealed a positive feedback loop of Ifng, Stat1, and Tlr3 gene signaling that was triggered by the HA-G222 variant and correlated with a clinical symptom score indicating disease severity. PMID:27536272

  12. Elimination of the biphasic pharmacodynamics of 15d-PGJ2 by controlling its release from a nanoemulsion

    PubMed Central

    Abbasi, Saed; Kajimoto, Kazuaki; Harashima, Hideyoshi

    2016-01-01

    15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has a dual action of stimulating anti-inflammation and anti-proliferation when exogenously administered at high doses. However, at lower doses, it can be toxic inducing opposite actions, ie, stimulation of both inflammation and cell proliferation. This biphasic phenomenon of 15d-PGJ2 is believed to be due to its multitarget behavior. In this study, we provide a strategy for controlling such biphasic pharmacodynamics by separating its dual actions while retaining the beneficial one by using a nanoemulsion (NE). The 15d-PGJ2 was encapsulated in the NE composed of triolein/distearoyl phosphatidylcholine/Tween 80 at a high encapsulation ratio (>83%). Furthermore, NE enhanced drug retention by slowing down its release rate, which was, unconventionally, inversely dependent on the total surface area of the NE system. Next, focusing on the biphasic effect on cell proliferation, we found that the 15d-PGJ2-loaded slow-release NE showed only a dose-dependent inhibition of the viability of a mouse macrophage cell line, RAW264.7, although a fast-release NE as well as free 15d-PGJ2 exerted a biphasic effect. The observed slow-release kinetics are believed to be responsible for elimination of the biphasic pharmacodynamics of 15d-PGJ2 mainly for two reasons: 1) a high proportion of 15d-PGJ2 that is retained in the NE was delivered to the cytosol, where proapoptotic targets are located and 2) 15d-PGJ2 was able to bypass cell membrane-associated targets that lead to the induction of cellular proliferation. Collectively, our strategy of eliminating the 15d-PGJ2-induced biphasic pharmacodynamics was based on the delivery of 15d-PGJ2 to its desired site of action, excluding undesired sites, on a subcellular level. PMID:27354798

  13. Metallothionein expression in benign and malignant canine mammary gland tumours.

    PubMed

    Erginsoy, S D; Sozmen, M; Caldin, M; Furlanello, T

    2006-08-01

    The presence of metallothioneins (MTs) were demonstrated immunohistochemically using a monoclonal antibody (E9) against a conserved epitope of I and II isoforms in canine mammary tumours. In a semiquantitative analysis MT expression in the tumour cells was observed in 54/54 cases of benign and 32/40 malignant mammary neoplasms. A statistically significant difference at the level of P<0.01 was observed for MT expression between benign and malign mammary tumours in terms of immunoreactivity score. It is concluded that immunohistochemically demonstrated MT expression is significantly associated with benign canine mammary tumours.

  14. MRI findings of benign monomelic amyotrophy of lower limb.

    PubMed

    Hamano, T; Mutoh, T; Hirayama, M; Ito, K; Kimura, M; Aita, T; Kiyosawa, K; Ohtaki, T; Kuriyama, M

    1999-06-01

    We report here magnetic resonance imaging (MRI) findings of two patients with benign monomelic amyotrophy of lower limb. Both subjects showed unilateral amyotrophy of the lower limb with a benign clinical course, and the affected muscles demonstrated neurogenic changes. On T1- and T2-weighted MRI, marked atrophy and increased signal intensity were found mainly in gastrocnemius and soleus muscles. Moreover, MRI examination also revealed that thigh muscles including semitendinosus, semimembranosus, and vastus intermedius and lateralis muscles were involved in one of the patients. We concluded that muscle MRI is very useful for detecting affected muscles, especially deep skeletal muscles in patients with benign monomelic amyotrophy of lower limb.

  15. Rheology of aqueous foams

    NASA Astrophysics Data System (ADS)

    Dollet, Benjamin; Raufaste, Christophe

    2014-10-01

    Aqueous foams are suspensions of bubbles inside aqueous phases. Their multiphasic composition leads to a complex rheological behavior that is useful in numerous applications, from oil recovery to food/cosmetic processing. Their structure is very similar to the one of emulsions, so that both materials share common mechanical properties. In particular, the presence of surfactants at the gas-liquid interfaces leads to peculiar interfacial and dissipative properties. Foam rheology has been an active research topics and is already reported in several reviews, most of them covering rheometry measurements at the scale of the foam, coupled with interpretations at the local scale of bubbles or interfaces. In this review, we start following this approach, then we try to cover the multiscale features of aqueous foam flows, emphasizing regimes where intermediate length scales need to be taken into account or regimes fast enough regarding internal time scales so that the flow goes beyond the quasi-static limit. xml:lang="fr"

  16. Pesticide Removal from Aqueous Solutions by Adding Salting Out Agents

    PubMed Central

    Moscoso, Fátima; Deive, Francisco J.; Esperança, José M. S. S.; Rodríguez, Ana

    2013-01-01

    Phase segregation in aqueous biphasic systems (ABS) composed of four hydrophilic ionic liquids (ILs): 1-butyl-3-methylimidazolium methylsulfate and 1-ethyl-3-methylimidazolium methylsulfate (CnC1im C1SO4, n = 2 and 4), tributylmethyl phosphonium methylsulfate (P4441 C1SO4) and methylpyridinium methylsulfate (C1Py C1SO4) and two high charge density potassium inorganic salts (K2CO3 and K2HPO4) were determined by the cloud point method at 298.15 K. The influence of the addition of the selected inorganic salts to aqueous mixtures of ILs was discussed in the light of the Hofmeister series and in terms of molar Gibbs free energy of hydration. The effect of the alkyl chain length of the cation on the methylsulfate-based ILs has been investigated. All the solubility data were satisfactorily correlated to several empirical equations. A pesticide (pentachlorophenol, PCP) extraction process based on the inorganic salt providing a greater salting out effect was tackled. The viability of the proposed process was analyzed in terms of partition coefficients and extraction efficiencies. PMID:24145747

  17. Microwave thermotherapy for benign prostatic hyperplasia.

    PubMed

    Hoffman, Richard M; Monga, Manoj; Elliott, Sean P; Macdonald, Roderick; Langsjoen, Jens; Tacklind, James; Wilt, Timothy J

    2012-09-12

    Transurethral resection of the prostate (TURP) has been the gold-standard treatment for alleviating urinary symptoms and improving urinary flow in men with symptomatic benign prostatic hyperplasia (BPH). However, the morbidity of TURP approaches 20%, and less invasive techniques have been developed for treating BPH. Preliminary data suggest that microwave thermotherapy, which delivers microwave energy to produce coagulation necrosis in prostatic tissue, is a safe, effective treatment for BPH. To assess the therapeutic efficacy and safety of microwave thermotherapy techniques for treating men with symptomatic benign prostatic obstruction. Randomized controlled trials were identified from The Cochrane Library, MEDLINE, EMBASE, bibliographies of retrieved articles, reviews, technical reports, and by contacting relevant expert trialists and microwave manufacturers. All randomized controlled trials evaluating transurethral microwave thermotherapy (TUMT) for men with symptomatic BPH were eligible for this review. Comparison groups could include transurethral resection of the prostate, minimally invasive prostatectomy techniques, sham thermotherapy procedures, and medications. Outcome measures included urinary symptoms, urinary function, prostate volume, mortality, morbidity, and retreatment. Two review authors independently identified potentially relevant abstracts and then assessed the full papers for inclusion. Two review authors independently abstracted study design, baseline characteristics, and outcomes data and assessed methodological quality using a standard form. We attempted to obtain missing data from authors or sponsors, or both. In this update, we identified no new randomized comparisons of TUMT that provided evaluable effectiveness data. Fifteen studies involving 1585 patients met the inclusion criteria, including six comparisons of microwave thermotherapy with TURP, eight comparisons with sham thermotherapy procedures, and one comparison with an alpha

  18. Benign emptying of the postpneumonectomy space.

    PubMed

    Merritt, Robert E; Reznik, Scott I; DaSilva, Marcelo C; Sugarbaker, David J; Whyte, Richard I; Donahue, Dean M; Hoang, Chuong D; Smythe, W Roy; Shrager, Joseph B

    2011-09-01

    A fall in the postpneumonectomy fluid level is considered a sign of bronchopleural fistula (BPF) requiring surgical intervention. We have discovered however that in rare asymptomatic patients, this event may not require aggressive surgical treatment. After seeing a case of benign emptying of the postpneumonectomy space (BEPS), we surveyed 28 surgeons to determine its incidence and characteristics. Forty-four cases of BEPS were reported by 23 survey respondents. Among 7 fully documented cases from 4 institutions, we defined the following criteria: the patient must be asymptomatic (no fever, white cell count elevation, or fluid expectoration), negative culture results if fluid sampled (patient not receiving antibiotics), no BPF at bronchoscopy or ventilation scintigraphy scan (or both), and recovery without drainage, or retrospective assessment that the intervention was unnecessary. BEPS occurred between 5 days and 152 days after pneumonectomy (6 cases right pneumonectomy and 1 case left pneumonectomy). Four patients underwent no treatment, 1 patient underwent thoracoscopic exploration (sterile) and closure after antibiotic irrigation, 1 patient underwent thoracoscopic exploration alone, and 1 patient underwent open window thoracostomy (sterile) with eventual closure. In all 7 patients (except the patient who underwent the open window procedure) the space refilled within 8 weeks; no patient experienced a subsequent empyema/BPF. Four patients who met the initial criteria for BEPS went on to experience empyema. The incidence of BEPS appears related to pneumonectomy volume, particularly extrapleural pneumonectomy. Using surgeon volume assumptions, the incidence of BEPS is 0.65%. To our knowledge, BEPS is a previously unreported occurrence. We hypothesize that it results from postoperative intrapleural pressure shifts, with or without a microscopic BPF, that drive fluid out of the pleural space while failing to cause contamination. Awareness of BEPS' existence may allow

  19. Diagnosis and treatment of pediatric benign pneumoperitoneum

    PubMed Central

    Duan, Shou-Xing; Sun, Zong-Bo; Wang, Guang-Huan; Zhong, Jun; Ou, Wen-Hui; Fu, Ma-Xian; Wang, Fu-Sheng; Ma, Shu-Hua; Li, Jian-Hong

    2017-01-01

    Abstract Introduction: Benign pneumoperitoneum (BPPT) is defined as asymptomatic free intraabdominal air or as pneumoperitoneum without peritonitis. Symptomatic free air requires surgical anagement, but management of asymptomatic pneumoperitoneum is controversial. In this study, we investigate the diagnosis and treatment of BPPT in children. Clinical Findings: The clinical data of 9 pediatric patients with BPPT who were admitted to our hospital from January 2000 to January 2015 were retrospectively analyzed to summarize the diagnosis and treatment. Overall, 9 cases were included with 8 males and 1 female, aged from 4 days to 4 years. Among them there were 6 newborns (including 1 premature infant). Patients were all admitted to hospital with the major clinical symptom of abdominal distension, including 2 cases accompanied by tachypnea, 2 cases with vomiting, 1 case with diarrhea, and 2 cases with fever. No previous constipation or obstructive defecation existed. Six newborns had meconium defecation within 24 hours after birth. Physical examination revealed all patients with relaxed abdominal wall except 1 patient with abdominal distension had slight muscle stiffness and hyperactive bowel sounds. Abdominal X-ray suggested free air under the diaphragm in all cases. Interventions/Outcomes: All patients except for one case of laparotomy were conservatively treated and cured with fasting, infection prevention, rehydration, abdominocentesis, and close observation. Nine cases of patients were all discharged with no death occurrence. After discharge follow-up of 7 months to 6 years was conducted. There was no recurrence of similar symptoms, and children were in good growth and development. Conclusion: The diagnosis of BPPT mainly relies on clinical symptoms in patient, careful abdominal examination, abdominal X-ray combined with abdominocentesis, and the exclusion of gastrointestinal perforation for confirmation. Conservative treatment can cure the disease. Attention

  20. Oxidative Stress Promotes Benign Prostatic Hyperplasia

    PubMed Central

    Vital, Paz; Castro, Patricia; Ittmann, Michael

    2017-01-01

    BACKGROUND Benign prostatic hyperplasia (BPH) is characterized by increased tissue mass in the transition zone of the prostate, which leads to obstruction of urine outflow and significant morbidity in the majority of older men. Plasma markers of oxidative stress are increased in men with BPH but it is unclear whether oxidative stress and/or oxidative DNA damage are causal in the pathogenesis of BPH. METHODS Levels of 8-OH deoxyguanosine (8-OH dG), a marker of oxidative stress, were measured in prostate tissues from normal transition zone and BPH by ELISA. 8-OH dG was also detected in tissues by immunohistochemistry and staining quantitated by image analysis. Nox4 promotes the formation of reactive oxygen species. We therefore created and characterized transgenic mice with prostate specific expression of Nox4 under the control of the prostate specific ARR2PB promoter. RESULTS Human BPH tissues contained significantly higher levels of 8-OH dG than control transition zone tissues and the levels of 8-OH dG were correlated with prostate weight. Cells with 8-OH dG staining were predominantly in the epithelium and were present in a patchy distribution. The total fraction of epithelial staining with 8-OH dG was significantly increased in BPH tissues by image analysis. The ARR2PB-Nox4 mice had increased oxidative DNA damage in the prostate, increased prostate weight, increased epithelial proliferation, and histological changes including epithelial proliferation, stromal thickening, and fibrosis when compared to wild type controls. CONCLUSIONS Oxidative stress and oxidative DNA damage are important in the pathogenesis of BPH. PMID:26417670