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Sample records for fluid membrane-based soluble

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

    SciTech Connect

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

    2005-10-14

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

  2. Lamellar biogels: Fluid-membrane-based hydrogels containing polymer lipids

    SciTech Connect

    Warriner, H.E.; Idziak, S.H.J.; Slack, N.L.

    1996-02-16

    A class of lamellar biological hydrogels comprised of fluid membranes of lipids and surfactants with small amounts of low molecular weight poly(ethylene glycol)-derived polymer pipids (PEG-lipids) were studied by x-ray diffraction, polarized light microscopy, and rheometry. In contrast to isotropic hydrogels of polymer networks, these membrane-based birefringent liquid crystalline biogels, labeled L{sub {alpha},g,} form the gel phase when water is added to the liquid-like lamellar L{sub {alpha}} phase, which reenters a liquid-like mixed phase upon further dilution. Furthermore, gels with larger water content require less PEG-lipid to remain stable. Although concentrated ({approx}50 weight percent) mixtures of free PEG (molecular weight, 5000) and water do not gel, gelatin does occur in mixtures containing as little as 0.5 weight percent PEG lipid. A defining signature of the L{sub {alpha}, g} regime as it sets in from the fluid lamellar L{sub {alpha}} phase is the proliferation of layer-dislocation-type defects, which are stabilized by the segregation of PEG-lipids to the defect regions of high membrane curvature that connect the membranes. 32 refs., 5 figs.

  3. Controls on Calcite Solubility in Metamorphic and Magmatic Fluids

    NASA Astrophysics Data System (ADS)

    Manning, C. E.; Eguchi, J.; Galvez, M.

    2015-12-01

    Calcite is an important hydrothermal alteration product in a wide range of environments. The role of calcite in hydrothermal alteration depends on its solubility in geologic fluids, especially H2O. At ambient T and P, calcite solubility is low and it exhibits well-known declining, or "reverse", solubility with rising T. However, experimental and theoretical studies show that increasing P yields higher solubility and restricts the region of reverse solubility behavior to higher temperature. At 0.2 GPa the reverse solubility region lies at T>600°C; at 0.5 GPa, >800°C. Thus, whereas calcite possesses relatively low solubility in pure H2O in shallow hydrothermal systems (typically <10 ppm C), it is substantially more soluble at conditions of middle and lower crustal metamorphism and magmatism, reaching concentrations ≥1000 ppm. At the higher P of subduction zones, aragonite solubility in H2O is even greater. Thus, neglecting other solubility controls, calcite precipitation is favored as crustal fluids cool and/or decompress. However, the solubility of calcite in H2O also depends strongly on other solutes, pH, and fO2. Sources of alkalinity decrease calcite solubility. In contrast, sources of acidity such as CO2 and Cl increase solubility. Crustal fluids can be enriched in alkali halides such as NaCl. Calcite solubility increases with increasing salt content at a given P and T. From approximately seawater salinity to salt saturation, the fluid behaves as a dilute molten salt and calcite solubility increases as the square of the salt mole fraction regardless of the alkali (Li, Na, K, Cs) or halogen (F, Cl, Br, I) considered. Similar behavior is seen in mixed salt solutions. At lower salinities, solubility behavior is as expected in dilute electrolyte solutions. The transition from dilute electrolyte to molten salt is fundamental to the properties of crustal fluids. Reduction of carbonate species or CO2 in the fluid to CH4, which is common during serpentinization of

  4. Dietary fiber content influences soluble carbohydrate levels in ruminal fluids.

    PubMed

    Pinder, R S; Patterson, J A; O'Bryan, C A; Crandall, P G; Ricke, S C

    2012-01-01

    The soluble carbohydrate concentration of ruminal fluid, as affected by dietary forage content (DFC) and/or ruminally undegradable intake protein content (UIPC), was determined. Four ruminally cannulated steers, in a 4 × 4 Latin square design, were offered diets containing high (75 % of DM) or low (25 % of DM) DFC and high (6 % of DM) or low (5 % of DM) UIPC, in a 2 × 2 factorial arrangement. Zinc-treated SBM was the primary UIP source. Soluble hexose concentration (145.1 μM) in ruminal fluid (RF) of steers fed low DFC diets exhibited a higher trend (P = 0.08) than that (124.5 μM) of steers fed high DFC diets. UIPC did not modulate (P = 0.54) ruminal soluble hexose concentrations. Regardless of diet, soluble hexose concentration declined immediately after feeding and did not rise until 3 h after feeding (P < 0.0001). Cellobiose (≈90 %) and glucose (≈10 %) were the major soluble hexoses present in RF. Maltose was not detected. Soluble glucose concentration (13.0 μM) was not modified by either UIPC (P = 0.40) nor DFC (P = 0.61). However, a DFC by post-prandial time interaction was detected (P = 0.02). Pentose concentrations were greater (P = 0.02) in RF of steers fed high DFC (100.2 μM) than steers fed low DFC (177.0 μM). UIPC did not influence (P = 0.35) soluble pentose concentration. The identity of soluble pentoses in ruminal fluid could not be determined. However, unsubstituted xylose and arabinose were excluded. These data indicate that: (i) soluble carbohydrate concentrations remain in ruminal fluid during digestion and fermentation; (ii) slight diurnal changes began after feeding; (iii) DFC influences the soluble carbohydrate concentration in RF; and (iv) UIPC of these diets does not affect the soluble carbohydrate concentration of RF.

  5. Potentiometric analysis of water soluble cutting fluid-metal combinations

    SciTech Connect

    Kelley, E.E.

    1991-12-01

    The results of corrosion studies conducted by the University of Kansas under Contract G257763 for Allied-Signal Inc., Kansas City Division (KCD), are given. These potentiometric studies evaluate the corrosivity of two water soluble cutting fluids at varying concentrations on samples of 304 stainless steel, 6061-T6 aluminum, and beryllium copper. This testing serves two purposes: (1) to develop effective test procedures adaptable to existing KCD corrosion measurement equipment for corrosion analysis of cutting fluid-metals combinations, and (2) to understand the relative corrosiveness of the varying water soluble cutting fluids on different metals. The tests used were adapted from the American Society of Testing Materials (ASTM). Future testing will identify polarization techniques for establishing corrosion rates which will be used in evaluating both water soluble cutting fluids and other aqueous solutions used at KCD.

  6. Development of supercritical fluid extraction and supercritical fluid chromatography purification methods using rapid solubility screening with multiple solubility chambers.

    PubMed

    Gahm, Kyung H; Huang, Ke; Barnhart, Wesley W; Goetzinger, Wolfgang

    2011-01-01

    Rapid solubility screening in diverse supercritical fluids (SCFs) was carried out via multiple solubility chambers with a trapping device and online ultraviolet (UV) detection. With this device, it was possible to rapidly study the solubility variations of multiple components in a mixture. Results from solubility studies have been used to develop efficient supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) methods. After the investigation of solubilities of theophylline and caffeine in several neat organic solvents and SCFs, advantages of SFE over conventional organic solvent extraction were demonstrated with a model mixture of theophylline and caffeine. The highest solubility ratio of 1:40 (theophylline:caffeine) was observed in the SCF with 20% acetonitrile (MeCN), where a ratio of 1:11 was the highest in the neat organic solvents. A model mixture of theophylline:caffeine (85:15 w/w, caffeine as an impurity) was successfully purified by SFE by leveraging the highest solubility difference. The SCF with 20% MeCN selectively removed caffeine and left theophylline largely intact. Rapid SCF solubility screening was applied to development of SFE and SFC methods in a drug discovery environment. Two successful applications were demonstrated with proprietary Amgen compounds to either remove an achiral impurity before chiral purification or enhance chiral chromatographic throughput.

  7. Solubilities in supercritical fluids: the application of chromatographic measurement methods

    SciTech Connect

    Smith, R.D.; Udseth, H.R.; Wright, B.W.; Yonker, C.R.

    1987-01-01

    New methods are described for the measurement of the solubilities of solids in supercritical fluids. These methods utilize instrumentation developed for capillary supercritical fluid chromatography consisting of deactivated, small diameter, fused silica tubing, coupled with detection methods based upon on flame ionization and mass spectrometric detectors. The methods involve (a) direct solubility determination where the fused silica capillary is used as an equilibrium cell, and (b) a pressure of threshold solubility technique which resembles chromatography and uses a programmed pressure increase and sensitive detection to determine the onset of solute migration. Results are also presented which suggest that solubilities can be determined, within certain limitations, from actual chromatographic experiments. The methods are illustrated using aromatic hydrocarbons and complex mycotoxins of the trichothecene group.

  8. Cross-linked high conductive membranes based on water soluble ionomer for high performance proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Guo, Xin; Zhang, Gang; Ni, Jing; Zhao, Chengji; Liu, Zhongguo; Zhang, Liyuan; Li, Mingyu; Xu, Shuai; Na, Hui

    2013-11-01

    In this paper, a series of proton exchange membranes prepared by “Click Reaction” are reported. The cross-linked membranes are based on water soluble sulfonated poly (ether ether ketone) containing dipropenyl groups (SDPEEK-nE/nH). Compared with self-crosslinked membranes (SDPEEK-nS), this “Click” cross-linked membranes using 1,2-Ethanedithiol and 1,6-Hexanedithiol as the cross-linker exhibit extremely reduced water uptake and swelling ratio. The lowest proton conductivity at 80 °C of the “Click” cross-linked membranes reaches to 0.168 S cm-1, and the highest methanol permeability of the “Click” cross-linked SDPEEK-8E is only 4.13 × 10-7 cm2 s-1, which is 5 times lower than that of Nafion 117 membrane. All the results imply that the cross-linked membranes with novel thiol cross-linker are promising alternative material for fuel cell application.

  9. Cu and Ni solubility in high-temperature aqueous fluids

    NASA Astrophysics Data System (ADS)

    Watenphul, A.; Scholten, L.; Beermann, O.; Kavner, A.; Alraun, P.; Falkenberg, G.; Newville, M.; Lanzirotti, A.; Schmidt, C.

    2013-12-01

    Copper and nickel are generally associated in magmatic sulfide ores formed by immiscibility in mafic and ultramafic magmas. In contrast, hydrothermal Cu-Ni deposits are uncommon and these elements usually occur in separate Cu-Fe-sulfide and Ni-Co-Ag-Bi-As-S mineralizations. Among the porphyry-type deposits formed at high temperatures to about 700 °C, there are many copper but no nickel deposits [1], pointing to a higher solubility of Cu relative to Ni in aqueous fluids at such conditions. The aim of this study is to measure the solubilities of Cu and Ni sulfides in high-temperature hydrothermal fluids in-situ using synchrotron-radiation micro-X-ray fluorescence spectrometry. Synthetic CuS or NiS crystals were partly dissolved in aqueous NaCl, NaCl+HCl, or CaCl2 solutions at temperatures of 400 to 600 °C and pressures between 70 and 900 MPa using a modified hydrothermal diamond-anvil cell with a recess in one diamond [2]. Consecutive XRF spectra of the fluid in the recess were collected in a confocal mode to exclude signal contributions from the crystals in the sample chamber [3]. Equilibrium was assumed if the determined concentrations of the dissolved metals indicated that a steady state was attained. The measured dissolved Cu concentrations ranged between 22 ppm at 70 MPa, 500 °C and 235 ppm at 306 MPa, 600 °C in 0.5 to 1.6 m NaCl solutions. We observed a decrease in Cu concentration with increasing pressure at constant temperature, and for 1.6 m NaCl an increase by a factor of two along an isochore from 120 MPa, 500 °C to 306 MPa, 600 °C. Higher Cu solubilities were determined in more concentrated solutions. A preliminary run with a more acidic NaCl+HCl solution (pH ~1) revealed a dramatic increase in the dissolved Cu concentration to 7898 ppm at 170 MPa, 500 °C. The measured dissolved Ni concentrations ranged between 3 ppm at 200 MPa, 500 °C in a 1 m NaCl solution and 33 ppm at 411 MPa, 500 °C in a 0.75 m CaCl2 solution. A solubility maximum at 500

  10. Frenkel line and solubility maximum in supercritical fluids.

    PubMed

    Yang, C; Brazhkin, V V; Dove, M T; Trachenko, K

    2015-01-01

    A new dynamic line, the Frenkel line, has recently been proposed to separate the supercritical state into rigid-liquid and nonrigid gaslike fluid. The location of the Frenkel line on the phase diagram is unknown for real fluids. Here we map the Frenkel line for three important systems: CO(2), H(2)O, and CH(4). This provides an important demarcation on the phase diagram of these systems, the demarcation that separates two distinct physical states with liquidlike and gaslike properties. We find that the Frenkel line can have a similar trend as the melting line above the critical pressure. Moreover, we discuss the relationship between unexplained solubility maxima and Frenkel line, and we propose that the Frenkel line corresponds to the optimal conditions for solubility.

  11. Ethanol effects on apparent solubility of poorly soluble drugs in simulated intestinal fluid.

    PubMed

    Fagerberg, Jonas H; Al-Tikriti, Yassir; Ragnarsson, Gert; Bergström, Christel A S

    2012-07-02

    Ethanol intake can lead to an unexpected and possibly problematic increase in the bioavailability of druglike compounds. In this work we investigated the effect of ethanol on the apparent solubility and dissolution rate of poorly soluble compounds in simulated intestinal fluid representing a preprandial state. A series of 22 structurally diverse, poorly soluble compounds were measured for apparent solubility and intrinsic dissolution rate (37 °C) in phosphate buffer pH 6.5 (PhB6.5) and fasted state simulated intestinal fluid (FaSSIF, pH 6.5) with and without ethanol at 5% v/v or 20% v/v. The obtained data were used to understand for which molecules ethanol results in an increased apparent solubility and, therefore, may increase the amount of drug absorbed. In FaSSIF20%ethanol 59% of the compounds displayed >3-fold higher apparent solubility than in pure FaSSIF, whereas the effects of 5% ethanol on solubility, in most cases, were negligible. Acidic and neutral compounds were more solubilized by the addition of ethanol than by lecithin/taurocholate aggregates, whereas bases showed a more substance-specific response to the additives in the buffer. The stronger solubilizing capacity of ethanol as compared to the mixed lipid aggregates in FaSSIF was further identified through Spearman rank analyses, which showed a stronger relationship between FaSSIF20%ethanol and PhB6.5,20%ethanol (rS of 0.97) than FaSSIF20%ethanol and FaSSIF (rS of 0.86). No relationships were found between solubility changes in media containing ethanol and single physicochemical properties, but multivariate data analysis showed that inclusion of ethanol significantly reduced the negative effect of compound lipophilicity on solubility. For this data set the higher concentration of ethanol gave a dose number (Do) <1 for 30% of the compounds that showed incomplete dissolution in FaSSIF. Significant differences were shown in the melting point, lipophilicity, and dose profiles between the compounds

  12. Highly potent soluble amyloid-β seeds in human Alzheimer brain but not cerebrospinal fluid

    PubMed Central

    Kaeser, Stephan A.; Maia, Luis F.; Portelius, Erik; Pinotsi, Dorothea; Kaminski, Clemens F.; Winkler, David T.; Maetzler, Walter; Keyvani, Kathy; Spitzer, Philipp; Wiltfang, Jens; Kaminski Schierle, Gabriele S.; Zetterberg, Henrik; Staufenbiel, Matthias; Jucker, Mathias

    2017-01-01

    The soluble fraction of brain samples from patients with Alzheimer’s disease contains highly biologically active amyloid-β seeds. In this study, we sought to assess the potency of soluble amyloid-β seeds derived from the brain and cerebrospinal fluid. Soluble Alzheimer’s disease brain extracts were serially diluted and then injected into the hippocampus of young, APP transgenic mice. Eight months later, seeded amyloid-β deposition was evident even when the hippocampus received subattomole amounts of brain-derived amyloid-β. In contrast, cerebrospinal fluid from patients with Alzheimer’s disease, which contained more than 10-fold higher levels of amyloid-β peptide than the most concentrated soluble brain extracts, did not induce detectable seeding activity in vivo. Similarly, cerebrospinal fluid from aged APP-transgenic donor mice failed to induce cerebral amyloid-β deposition. In comparison to the soluble brain fraction, cerebrospinal fluid largely lacked N-terminally truncated amyloid-β species and exhibited smaller amyloid-β-positive particles, features that may contribute to the lack of in vivo seeding by cerebrospinal fluid. Interestingly, the same cerebrospinal fluid showed at least some seeding activity in an in vitro assay. The present results indicate that the biological seeding activity of soluble amyloid-β species is orders of magnitude greater in brain extracts than in the cerebrospinal fluid. PMID:25212850

  13. Drug solubility in luminal fluids from different regions of the small and large intestine of humans.

    PubMed

    Fadda, H M; Sousa, T; Carlsson, A S; Abrahamsson, B; Williams, J G; Kumar, D; Basit, A W

    2010-10-04

    The purpose of this work was to study the solubility of two drugs with different physicochemical properties in luminal fluids obtained from various regions of the human gastrointestinal (GI) tract and to determine the most important luminal parameters influencing their solubility. Jejunal fluids were aspirated from healthy volunteers via an oral intubation tube. Ileal and colonic fluids were obtained from patients undergoing GI surgery. Stoma fluids were also retrieved from patients. pH and buffer capacity of all fluids were determined. Saturation solubility of prednisolone (unionisable) and mesalamine (5-aminosalicylic acid) (zwitterionic) was measured. Mean solubility of prednisolone in the different luminal fluids was 0.50 mg/mL (±0.05) and did not vary significantly between the different regions of the GI tract (ANOVA, p > 0.05). No correlation between prednisolone solubility and jejunal bile salt content was found. Mesalamine solubility increased down the GI tract: 1.97 (±0.25), 3.26 (±0.08), 6.24 (±1.13) and 7.95 (±0.21) mg/mL in jejunal, ileal, ascending and transverse/descending colonic fluids respectively. Buffer capacity also increased and in one patient was observed to range from 6.4 to 28.6 reaching 44.4 mM/L/pH unit in ileal, ascending and transverse/descending colon fluids respectively. Mesalamine solubility was found to be dependent on both buffer capacity and pH, with buffer capacity being the most important (standardized coefficient β = 0.849, p < 0.0001) compared to pH (β = 0.219, p < 0.05). For drugs delivered as modified release formulations it is important to consider solubility in different regions of the GI tract as significant differences can arise which will ultimately influence drug bioavailability.

  14. A review of drug solubility in human intestinal fluids: implications for the prediction of oral absorption.

    PubMed

    Augustijns, Patrick; Wuyts, Benjamin; Hens, Bart; Annaert, Pieter; Butler, James; Brouwers, Joachim

    2014-06-16

    The purpose of this paper is to collate all recently published solubility data of orally administered drugs in human intestinal fluids (HIF) that were aspirated from the upper small intestine (duodenum and jejunum). The data set comprises in total 102 solubility values in fasted state HIF and 37 solubility values in fed state HIF, covering 59 different drugs. Despite differences in the protocol for HIF sampling and subsequent handling, this summary of HIF solubilities provides a critical reference data set to judge the value of simulated media for intestinal solubility estimation. In this regard, the review includes correlations between the reported solubilizing capacity of HIF and fasted or fed state simulated intestinal fluid (FaSSIF/FeSSIF). Correlating with HIF solubilities enables the optimal use of solubility measurements in simulated biorelevant media to obtain accurate estimates of intestinal solubility during drug development. Considering the fraction of poorly soluble new molecular entities in contemporary drug discovery, adequate prediction of intestinal solubility is critical for efficient lead optimization, early candidate profiling, and further development.

  15. A supercritical fluid-based coating technology. 2: solubility considerations.

    PubMed

    Ribeiro Dos Santos, I; Thies, C; Richard, J; Le Meurlay, D; Gajan, V; VandeVelde, V; Benoit, J-P

    2003-01-01

    Solubility measurements of candidate coating materials have been performed in supercritical (SC) CO(2) so as to select appropriate coating materials for implementation of a solvent-free coating process previously described. Solubility of lipidic compounds such as waxes (paraffin, beeswax, Carnauba wax), pure triglycerides (tricaprin, trimyristin, tripalmitin, tristearin) and mixture of glycerides and fatty acid esters (Gelucire) in SC CO(2) were evaluated in a static mode under different temperature and pressure conditions, ranging from 13-52 degrees C and from 50-220 bar, whether the CO(2)was in its liquid or SC state. It was shown that the compounds which are mixtures of various components give rise to a selective extraction of the lower melting point components, as evidenced from thermal analysis of soluble and insoluble fractions of the coating materials.

  16. Purification method development for chiral separation in supercritical fluid chromatography with the solubilities in supercritical fluid chromatographic mobile phases.

    PubMed

    Gahm, Kyung H; Tan, Helming; Liu, Jodi; Barnhart, Wesley; Eschelbach, John; Notari, Steve; Thomas, Samuel; Semin, David; Cheetham, Janet

    2008-04-14

    A comprehensive approach was applied to develop a chiral purification method for an analyte that was found to be unusually difficult to scale-up in supercritical fluid chromatography (SFC). This was performed by studying major factors such as the solubility of an analyte in SFC mobile phases, impurity profiles, and cycle time. For this case study, the solubility in SFC mobile phase was measured by a packed column technique, coupled with a novel trapping mechanism to enhance measurement precision in SFC conditions. The solubility studies in SFC mobile phases suggested a couple of possible SFC mobile phases, in which the analyte would potentially be most soluble. The SFC methods were developed to purify a sample containing 15% of an impurity, after considering impurity profiles and cycle times of several potential methods in addition to SFC mobile phase solubility. An equal volume mixture of acetonitrile and ethanol was chosen for the final purification method, since this mixture demonstrated the relatively high SFC solubility among all solvent combinations with enhanced resolution between the analyte and the impurity as well as the shortest run time. The solubility of the compound was also determined in various organic solvents using a high throughput solubility screening system to better understand relative change of solubility from neat solution to SFC mobile phases.

  17. Advances in Constraining Solubilities of H-O-C-S-Cl-bearing Fluids in Silicate Melts

    NASA Astrophysics Data System (ADS)

    Webster, J. D.

    2009-12-01

    Magmatic-hydrothermal fluids that are variably enriched in the volatile components H2O, CO2/CH4, H2S/SO2, Cl, F, ± B alter rock; dissolve, transport, and deposit ore metals, and drive volcanism. The efficacy of these processes varies directly with the compositions and quantities, and in particular, with the molar volumes of the fluids involved. Although natural hydrothermal fluids are geochemically diverse, experimental constraints on volatile solubilities in silicate melts are largely limited to two volatiles. Recent experimental research, however, has begun to address mutual solubility relationships of three and four volatiles in felsic to intermediate aluminosilicate melts at shallow crustal pressures. Following well-established correlations demonstrating that as little as a few hundred to thousand ppm CO2 or Cl reduce H2O solubility in melts, and hence enhance the tendency for magma to exsolve one or two fluid phases, recent work shows fundamentally important solubility relationships involving H2O, S, and Cl. Research on rhyodacitic (Botcharnikov et al., 2004) and phonolitic melts at 200 MPa reveals that hundreds to thousands of ppm S will reduce Cl solubility in these melts. Thus, S reduces Cl solubility, which in turn reduces H2O solubility in melts. Other investigations have determined that CaSO4 solubility in oxidizing hydrothermal fluids varies directly with the concentrations of NaCl ± KCl in these fluids (Newton and Manning, 2005; Webster et al., 2009). The CaSO4 contents in the most alkali chloride-enriched fluids exceed 60 wt.%. It follows that some mineralizing saline magmatic fluids are strongly enriched in Ca, Na, K, Cl, SO4, and reduced S species. Research on H2O-, CO2-, and Cl-bearing melts at 200 MPa also highlights critical reciprocal volatile solubility behavior. Work at 1200°C on andesitic melts saturated in two fluids determines that the presence of CO2 enlarges the immiscibility gap for vapor plus brine and increases the activities of H2O

  18. Selectively plugging subterranean formations with a hydrocarbon soluble fluid

    SciTech Connect

    Falk, D. O.

    1984-11-13

    Highly permeable zones in a subterranean formation vertically bounded by a relatively less permeable zone are selectively plugged by injecting an emulsion of melamine and formaldehyde in an alcohol medium via a well into the highly permeable zones. The emulsion is hydrocarbon soluble are preferentially envelops the highly permeable zones where it reacts to form a resin at a temperature of from about 80/sup 0/ C. to about 250/sup 0/ C. and a pH of from about 7 to 12 and over a period of from about 1 to 4 days. The resulting resin substantially plugs the highly permeable zones in the formation.

  19. Soluble Megalin is Reduced in Cerebrospinal Fluid Samples of Alzheimer’s Disease Patients

    PubMed Central

    Spuch, Carlos; Antequera, Desireé; Pascual, Consuelo; Abilleira, Soledad; Blanco, María; Moreno-Carretero, María José; Romero-López, Jesús; Ishida, Tetsuya; Molina, Jose Antonio; Villarejo, Alberto; Bermejo-Pareja, Felix; Carro, Eva

    2015-01-01

    Megalin or low-density lipoprotein receptor-related protein-2 is a member of the low-density lipoprotein receptor family, which has been linked to Alzheimer’s disease (AD) by clearing brain amyloid β-peptide (Aβ) across the blood–cerebrospinal fluid barrier at the choroid plexus. Here, we found a soluble form of megalin secreted from choroid plexus epithelial cells. Soluble megalin levels were also localized in the human cerebrospinal fluid (CSF), being reduced in AD patients. We have also shown that soluble megalin binding to Aβ is decreased in the CSF of AD patients, suggesting that decreased sequestration of Aβ in the CSF could be associated with defective clearance of Aβ and an increase of brain Aβ levels. Thus, therapies, which increase megalin expression, at the choroid plexus and/or enhance circulating soluble megalin hold potential to control brain Aβ-related pathologies in AD. PMID:25926771

  20. Solubility of Aragonite in Aqueous Fluids at High Pressure and High Temperature

    NASA Astrophysics Data System (ADS)

    Facq, Sébastien; Daniel, Isabelle; Petitgirard, Sylvain; Cardon, Hervé; Sverjensky, Dimitri

    2014-05-01

    Deep crustal and mantle aqueous fluids play a crucial role in geologic processes occurring in the Earth's interior, especially at high PT conditions. Dissolved carbon appears to be a major element constituting these aqueous fluids, occurring under the form of molecular species (CO2, CO, CH4), ionic species such as carbonate or bicarbonate ions or some more complex organic compounds [1]. However, the nature and the content of the chemical species constituting these C-bearing aqueous fluids may strongly be affected by the environmental geologic conditions such as the pressure and the temperature range. If fluid speciation and solubility of carbonate minerals are well characterized at HT and relatively low pressure, less is evident at pressure above 2 GPa where experimental challenges make trickier speciation and solubility measurements. Thanks to recent advances in theoretical aqueous geochemistry [1-3], combined experimental and theoretical efforts allow now the investigation of speciation and solubility of carbonate minerals with pure water at higher PT conditions than previously feasible [4]. However, direct measurements of solubility of carbonate minerals at HP-HT conditions are still needed to help to the development of quantitative models of carbon transport by aqueous fluids in subduction zones and validate existing aqueous speciation model. In this study, we present recent X-ray fluorescence measurements and thermodynamic model of solubility of carbonate in aqueous fluids at pressure up to 5 GPa. The amount of dissolved aragonite in the fluid has been measured from the intensity of the Ca K-lines at the ESRF-ID27 using an externally-heated membrane-type diamond anvil cell and an incident monochromatic focused X-Ray beam at 20 keV. The combination of the XRF data on dissolution of CaCO3mineral combined to previous speciation results permits now to calculate the solubility KS of aragonite a pressure in excess of 2 GPa. [1] Manning, C. E. et al., Review in

  1. New water-soluble metal working fluids additives from phosphonic acid derivatives for aluminum alloy materials.

    PubMed

    Kohara, Ichitaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short paper describes properties of new additives for water-soluble cutting fluids for aluminum alloy materials. Some alkyldiphosphonic acids were prepared with known method. Amine salts of these phosphonic acids showed anti-corrosion property for aluminum alloy materials. However, they have no hard water tolerance. Monoesters of octylphosphonic acid were prepared by the reaction of octylphosphonic acid dichloride with various alcohols in the presence of triethylamine. Amine salts of monoester of octylphosphonic acid with diethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether and triethyleneglycol monomethyl ether showed both of a good anti-corrosion property for aluminum alloy materials and hard water tolerance.

  2. A New Model for the Solubility of Water+Carbon Dioxide Mixed Fluids in Magmatic Systems

    NASA Astrophysics Data System (ADS)

    Ghiorso, M. S.; Gualda, G. A.

    2012-12-01

    A model is calibrated that permits estimation of the thermodynamic properties of dissolved H2O and CO2 components in silicate liquids of magmatic composition.The model is internally consistent with thermodynamic data/model collections in both MELTS (CMP 119; 197-212) and rhyolite-MELTS (JP 53, 875-890). It is calibrated from extensive literature data collected over a broad range of melt compositions (mafic to silicic) on the solubility of water (>1225 experiments, 700°-1600°C, 0-3 GPa), carbon dioxide (>450 experiments, 1150°-1800°C, 0-3.5 GPa), and mixed H2O-CO2 fluids (>140 experiments, 950°-1650°C, 0-3 GPa) in silicate liquids. The model reproduces these solubility data without bias over the entire range of temperature, pressure and composition. At lower pressures (<1 GPa) model residuals are within experimental uncertainty, but residuals are systematically larger at more elevated pressures. The model formulation relies on the EOS of Duan and Zhang (GCA 70, 2311-2324) for estimation of thermodynamic properties of fluid end members and of the mixed fluid. Melt properties are modeled under the simplifying assumption that water disassociates to hydroxyl species in the melt and that carbon dioxide dissolves as a molecular species. Both of these assumptions have been tested against more refined approximations involving speciation, with insufficient improvement of model recovery for solubility data to warrant the additional complexity. The calibrated mixed fluid model is an extension of and is backward compatible with the thermodynamic model for dissolved water in MELTS and rhyolite-MELTS. Additional calibration parameters for the mixed fluid include the enthalpy, entropy and volume of the CO2-melt component as well as regular solution-type interaction parameters between CO2 and "anhydrous" melt components (after MELTS); a total of 12 parameters in all. We find no compelling experimental evidence to justify a CO2-H2O interaction term in the melt. In addition to

  3. Supercritical fluid particle design for poorly water-soluble drugs (review).

    PubMed

    Sun, Yongda

    2014-01-01

    Supercritical fluid particle design (SCF PD) offers a number of routes to improve solubility and dissolution rate for enhancing the bioavailability of poorly water-soluble drugs, which can be adopted through an in-depth knowledge of SCF PD processes and the molecular properties of active pharmaceutical ingredients (API) and drug delivery system (DDS). Combining with research experiences in our laboratory, this review focuses on the most recent development of different routes (nano-micron particles, polymorphic particles, composite particles and bio-drug particles) to improve solubility and dissolution rate of poorly water-soluble drugs, covering the fundamental concept of SCF and the principle of SCF PD processes which are typically used to control particle size, shape, morphology and particle form and hence enable notable improvement in the dissolution rate of the poorly water-soluble drugs. The progress of the industrialization of SCF PD processes in pharmaceutical manufacturing environment with scaled-up plant under current good manufacturing process (GMP) specification is also considered in this review.

  4. The apparent solubilizing capacity of simulated intestinal fluids for poorly water-soluble drugs.

    PubMed

    Schwebel, Hervé J; van Hoogevest, Peter; Leigh, Mathew L S; Kuentz, Martin

    2011-06-01

    Drug solubility testing in biorelevant media has become an indispensable tool in pharmaceutical development. Despite this importance, there is still an incomplete understanding of how poorly soluble compounds interact with these media. The aim of this study was to apply the concept of the apparent solubilization capacity to fasted and fed state simulated intestinal fluid (FaSSIF and FeSSIF, respectively). A set of non-ionized poorly soluble compounds was studied in biorelevant media prepared from an instantly dissolving complex (SIF(™) Powder) at 37°C. The values of the solubilization capacity were different between FaSSIF and FeSSIF but correlated. Drug inclusion into the mixed micelles was highly specific for a given compound. The ratio of the FeSSIF to FaSSIF solubility was in particular considered and discussed in terms of the apparent solubilizing capacity. The apparent solubilization concept appears to be useful for the interpretation of biorelevant solubility tests. Further studies are needed to explore acidic and basic drugs.

  5. The effect of oxygen fugacity on the solubility of carbon-oxygen fluids in basaltic melt

    NASA Technical Reports Server (NTRS)

    Pawley, Alison R.; Holloway, John R.; Mcmillan, Paul F.

    1992-01-01

    The solubility of CO2-CO fluids in a midocean ridge basalt have been measured at 1200 C, 500-1500 bar, and oxygen fugacities between NNO and NNO-4. In agreement with results of previous studies, the results reported here imply that, at least at low pressures, CO2 dissolves in basaltic melt only in the form of carbonate groups. The dissolution reaction is heterogeneous, with CO2 molecules in the fluid reacting directly with reactive oxygens in the melt to produce CO3(2-). CO, on the other hand, is insoluble, dissolving neither as carbon, molecular CO, nor CO3(2-). It is shown that, for a given pressure and temperature, the concentration of dissolved carbon-bearing species in basaltic melt in equilibrium with a carbon-oxygen fluid is proportional to the mole fraction of CO2 in the fluid, which is a function of fO2. At low pressures CO2 solubility is a linear function of CO2 fugacity at constant temperatures.

  6. The effect of oxygen fugacity on the solubility of carbon-oxygen fluids in basaltic melt

    NASA Technical Reports Server (NTRS)

    Pawley, Alison R.; Holloway, John R.; Mcmillan, Paul F.

    1992-01-01

    The solubility of CO2-CO fluids in a midocean ridge basalt have been measured at 1200 C, 500-1500 bar, and oxygen fugacities between NNO and NNO-4. In agreement with results of previous studies, the results reported here imply that, at least at low pressures, CO2 dissolves in basaltic melt only in the form of carbonate groups. The dissolution reaction is heterogeneous, with CO2 molecules in the fluid reacting directly with reactive oxygens in the melt to produce CO3(2-). CO, on the other hand, is insoluble, dissolving neither as carbon, molecular CO, nor CO3(2-). It is shown that, for a given pressure and temperature, the concentration of dissolved carbon-bearing species in basaltic melt in equilibrium with a carbon-oxygen fluid is proportional to the mole fraction of CO2 in the fluid, which is a function of fO2. At low pressures CO2 solubility is a linear function of CO2 fugacity at constant temperatures.

  7. Equilibrium drug solubility measurements in 96-well plates reveal similar drug solubilities in phosphate buffer pH 6.8 and human intestinal fluid.

    PubMed

    Heikkilä, Tiina; Karjalainen, Milja; Ojala, Krista; Partola, Kirsi; Lammert, Frank; Augustijns, Patrick; Urtti, Arto; Yliperttula, Marjo; Peltonen, Leena; Hirvonen, Jouni

    2011-02-28

    This study was conducted to develop a high throughput screening (HTS) method for the assessment of equilibrium solubility of drugs. Solid-state compounds were precipitated from methanol in 96-well plates, in order to eliminate the effect of co-solvent. Solubility of twenty model drugs was analyzed in water and aqueous solutions (pH 1.2 and 6.8) in 96-well plates and in shake-flasks (UV detection). The results obtained with the 96-well plate method correlated well (R(2)=0.93) between the shake-flask and 96-well plates over the wide concentration scale of 0.002-169.2mg/ml. Thereafter, the solubility tests in 96-well plates were performed using fasted state human intestinal fluid (HIF) from duodenum of healthy volunteers. The values of solubility were similar in phosphate buffer solution (pH 6.8) and HIF over the solubility range of 10(2)-10(5)μg/ml. The new 96-well plate method is useful for the screening of equilibrium drug solubility during the drug discovery process and it also allows the use of human intestinal fluid in solubility screening.

  8. Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

    PubMed

    Watanabe, Shoji

    2008-01-01

    This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory.

  9. Preparation of water-soluble nanographite and its application in water-based cutting fluid

    PubMed Central

    2013-01-01

    Water-soluble nanographite was prepared by in situ emulsion polymerization using methacrylate as polymeric monomer. The dispersion stability and dispersion state of graphite particles were evaluated by UV-visible spectrophotometry and scanning electron microscopy, respectively. The water-soluble nanographite was then added into the water-based cutting fluid as lubricant additive. The lubrication performance of water-based cutting fluid with the nanographite additive was studied on four-ball friction tester and surface tensiometer. Results indicate that the modification method of in situ emulsion polymerization realizes the uniform and stabilized dispersion of nanographite in aqueous environment. The optimal polymerization condition is 70°C (polymerization temperature) and 5 h (polymerization time). The addition of nanographite decreases the friction coefficient and wear scar diameter by 44% and 49%. Meanwhile, the maximum non-seizure load (PB) increases from 784 to 883 N, and the value of surface tension (32.76 × 10−3 N/m) is at low level. Nanographite additive improves apparently the lubrication performance of water-based cutting fluid. PMID:23351483

  10. The phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids.

    PubMed

    Oyarzún, Bernardo; van Westen, Thijs; Vlugt, Thijs J H

    2013-05-28

    The liquid crystal phase behavior of linear and partially flexible hard-sphere chain fluids and the solubility of hard spheres in hard-sphere chain fluids are studied by constant pressure Monte Carlo simulations. An extensive study on the phase behavior of linear fluids with a length of 7, 8, 9, 10, 11, 12, 13, 14, 15, and 20 beads is carried out. The phase behavior of partially flexible fluids with a total length of 8, 10, 14, and 15 beads and with different lengths for the linear part is also determined. A precise description of the reduced pressure and of the packing fraction change at the isotropic-nematic coexistence was achieved by performing long simulation runs. For linear fluids, a maximum in the isotropic to nematic packing fraction change is observed for a chain length of 15 beads. The infinite dilution solubility of hard spheres in linear and partially flexible hard-sphere chain fluids is calculated by the Widom test-particle insertion method. To identify the effect of chain connectivity and molecular anisotropy on free volume, solubility is expressed relative to that of hard spheres in a hard sphere fluid at same packing fraction as relative Henry's law constants. A linear relationship between relative Henry's law constants and packing fraction is observed for all linear fluids. Furthermore, this linearity is independent of liquid crystal ordering and seems to be independent of chain length for linear chains of 10 beads and longer. The same linear relationship was observed for the solubility of hard spheres in nematic forming partially flexible fluids for packing fractions up to a value slightly higher than the nematic packing fraction at the isotropic-nematic coexistence. At higher packing fractions, the small flexibility of these fluids seems to improve solubility in comparison with the linear fluids.

  11. Composition of COH fluids at 1 GPa: an experimental study on speciation and solubility

    NASA Astrophysics Data System (ADS)

    Tiraboschi, Carla; Tumiati, Simone; Recchia, Sandro; Ulmer, Peter; Pettke, Thomas; Fumagalli, Patrizia; Poli, Stefano

    2014-05-01

    convoying evolved gases to a QMS through a heated line to avoid the condensation of water. This type of analyzer ensures superior performances in terms of selectivity of molecules to be detected, high acquisition rates and extended linear response range. The influence of dissolved solutes on fluid speciation has been evaluated by comparing experiments in the pure COH system and in the COH+forsterite system. To determine the solubility of forsterite in COH fluids we performed a second set of experiments at the same P , T and fO2 conditions above. Fluids trapped in a diamond layer were analysed by the cryogenic LA-ICP-MS technique described by Aerts et al. (2010). With this method the aqueous part of the COH fluid is frozen prior the opening and maintained frozen during the analysis to avoid any precipitation of solutes. The results will highlight the importance of fluids for the mass transport in subduction zones. Comparison between experimental data and thermodynamic calculation will also be shown. References: Aerts, M., Hack, A.C., Reusser, E., Ulmer, P. (2010) Am. Mineral. 95, 1523-1526. Newton, R.C., Manning, C.E. (2002) Geochim. Cosmochim. Ac. 66, 4165-4176.

  12. Solubility of indium-tin oxide in simulated lung and gastric fluids: Pathways for human intake.

    PubMed

    Andersen, Jens Christian Østergård; Cropp, Alastair; Paradise, Diane Caroline

    2017-02-01

    From being a metal with very limited natural distribution, indium (In) has recently become disseminated throughout the human society. Little is known of how In compounds behave in the natural environment, but recent medical studies link exposure to In compounds to elevated risk of respiratory disorders. Animal tests suggest that exposure may lead to more widespread damage in the body, notably the liver, kidneys and spleen. In this paper, we investigate the solubility of the most widely used In compound, indium-tin oxide (ITO) in simulated lung and gastric fluids in order to better understand the potential pathways for metals to be introduced into the bloodstream. Our results show significant potential for release of In and tin (Sn) in the deep parts of the lungs (artificial lysosomal fluid) and digestive tract, while the solubility in the upper parts of the lungs (the respiratory tract or tracheobronchial tree) is very low. Our study confirms that ITO is likely to remain as solid particles in the upper parts of the lungs, but that particles are likely to slowly dissolve in the deep lungs. Considering the prolonged residence time of inhaled particles in the deep lung, this environment is likely to provide the major route for uptake of In and Sn from inhaled ITO nano- and microparticles. Although dissolution through digestion may also lead to some uptake, the much shorter residence time is likely to lead to much lower risk of uptake. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Modeling of CO2 solubility in single and mixed electrolyte solutions using statistical associating fluid theory

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Panagiotopoulos, Athanassios Z.; Economou, Ioannis G.

    2016-03-01

    Statistical associating fluid theory (SAFT) is used to model CO2 solubilities in single and mixed electrolyte solutions. The proposed SAFT model implements an improved mean spherical approximation in the primitive model to represent the electrostatic interactions between ions, using a parameter K to correct the excess energies ("KMSA" for short). With the KMSA formalism, the proposed model is able to describe accurately mean ionic activity coefficients and liquid densities of electrolyte solutions including Na+, K+, Ca2+, Mg2+, Cl-, Br- and SO42- from 298.15 K to 473.15 K using mostly temperature independent parameters, with sole exception being the volume of anions. CO2 is modeled as a non-associating molecule, and temperature-dependent CO2-H2O and CO2-ion cross interactions are used to obtain CO2 solubilities in H2O and in single ion electrolyte solutions. Without any additional fitting parameters, CO2 solubilities in mixed electrolyte solutions and synthetic brines are predicted, in good agreement with experimental measurements.

  14. Exploring drug solubility in fasted human intestinal fluid aspirates: Impact of inter-individual variability, sampling site and dilution.

    PubMed

    de la Cruz-Moreno, Mariangeles Pérez; Montejo, Consuelo; Aguilar-Ros, Antonio; Dewe, Walthère; Beck, Benoît; Stappaerts, Jef; Tack, Jan; Augustijns, Patrick

    2017-08-07

    One of the main factors defining intestinal drug absorption is the solubility of the compound in the gastrointestinal environment. This study reports the solubility of a series of 27 commonly used acidic, neutral and basic drugs in human intestinal fluid samples collected from the duodenum or jejunum of healthy volunteers under fasted state conditions. The interindividual variability as well as the impact of factors such as pH, sampling site and bile salts on the solubility in human intestinal fluids was investigated. The solubility measurements were evaluated using a statistical experimental design. Variability in solubility across volunteers and sampling sites was highly compound-specific and appeared to be substantial for weak acids and bases and for lipophilic drugs. Both pH of the samples and the abundance of amphiphilic components were responsible for the variability observed in the solubility values obtained. The results confirm strong interindividual differences in intraluminal solubility, especially for compounds with high lipophilicity and/or compounds with a pKa value within the physiological pH range. It is important to recognize this variability in intestinal drug solubility as it may considerably influence the therapeutic outcome among patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Using Computational Fluid Dynamics to investigate the generation of soluble bedrock forms

    NASA Astrophysics Data System (ADS)

    Myre, J. M.; Covington, M. D.

    2014-12-01

    The roles and interactions of processes that generate bedforms in soluble bedrock settings are not yet fully understood. One outstanding puzzle is the morphogenesis of scallops. Current chemical theory does not allow dissolution rate to spatially vary under many of the conditions at which scallops are thought to form. This lack of variation in dissolution rate disagrees with the creation and existence of scallops for a large portion of the range of scallop sizes that are found in nature. Previous studies that have examined processes that generate bedforms using computational fluid dynamics (CFD) have made simplifying assumptions to ensure tractability. Consequently, tractability is sacrificed and some fine scale effects associated with the driving processes are not modeled. We incorporate Large-Eddy Simulation (LES) and adaptive meshing into a lattice-Boltzmann CFD method for fluid flow, chemical dissolution, and solute transport allowing relaxation of simplifying assumptions employed in previous models. These methods can model sub-grid scale turbulence and resolve the dissolution and precipitation processes occurring at the fluid-solid interface. We use this CFD model to simulate flow and dissolution over scallops and flutes to investigate the formational processes responsible for variations in dissolution rate that drive the spatio-temporal evolution of these features.

  16. In vitro ruminal fluid fermentation as influenced by corn-derived dried distillers' grains with solubles.

    PubMed

    Miśta, Sdorota; Pecka, Ewa; Zachwieja, Andrzej; Zawadzki, Wojciech; Bodarski, Rafał; Paczyńska, Katarzyna; Tumanowicz, Joanna; Kupczyński, Robert; Adamski, Maciej

    2014-01-01

    This study was conducted to evaluate changes to in vitro ruminal fluid fermentation due to the use of corn-derived dried distillers' grains with solubles (corn DDGS) as a partial or complete replacement for crushed cereal and oilseed meals in the fermentation substrate. The control substrate consisted of mixed cereal and oilseed meals (barley, wheat, soybean and rapeseed), while the experimental substrates were the same meals with increasing portions replaced with corn DDGS. Including corn DDGS decreased the total VFA concentration (P<0.05), ammonia level (P<0.001), methane emission (P<0.05) and total gas production (P<0.001) during microbial fermentation. Using DDGS-containing substrates did not change the proportions of acetate, propionate and butyrate, but did decrease the proportions of isobutyrate and isovalerate (P<0.001). The fermentation efficiency, VFA utilization index, cell yield coefficient and pH of the ruminal fluid also remained unchanged. The partial replacement of cereal and oilseed meals with corn DDGS had no deleterious effects on ruminal fluid fermentation.

  17. Method for separating metal chelates from other materials based on solubilities in supercritical fluids

    DOEpatents

    Wai, Chien M.; Smart, Neil G.; Phelps, Cindy

    2001-01-01

    A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents. In especially preferred embodiments, at least one of the chelating agents is fluorinated.

  18. Homocysteine metabolism is associated with cerebrospinal fluid levels of soluble amyloid precursor protein and amyloid beta.

    PubMed

    Oikonomidi, Aikaterini; Lewczuk, Piotr; Kornhuber, Johannes; Smulders, Yvo; Linnebank, Michael; Semmler, Alexander; Popp, Julius

    2016-10-01

    Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. The objective of this study was to investigate the relationships between cerebral amyloid production and both blood and cerebrospinal fluid (CSF) markers of the homocysteine metabolism. We assessed CSF concentrations of soluble APPα, soluble APPβ, and amyloid β1-42 (Aβ1-42), as well as plasma levels of homocysteine (Hcys), total vitamin B12, and folate, and CSF concentrations of homocysteine (Hcys-CSF), 5-methyltetrahydrofolate (5-MTHF), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) in 59 subjects with normal cognition. Linear regression analyses were performed to assess associations between homocysteine metabolism parameters and amyloid production. The study was approved by the Ethical Committee of the University of Bonn. After controlling for age, gender, APOEe4 status, and albumin ratio (Qalb), higher Aβ1-42 CSF levels were associated with high Hcys and low vitamin B12 plasma levels as well as with high Hcys, high SAH, and low 5-MTHF CSF levels. Higher CSF concentrations of sAPPα and sAPPβ were associated with high SAH levels. The results suggest that disturbed homocysteine metabolism is related to increased CSF levels of sAPP forms and Aβ1-42, and may contribute to the accumulation of amyloid pathology in the brain. Disturbed homocysteine metabolism may contribute to amyloidogenesis by modulating the amyloid precursor protein (APP) production and processing. We found associations between CSF levels of soluble APP forms and Aβ1-42, and markers of the homocysteine metabolism in both plasma and CSF in adults with normal cognition. Disturbed homocysteine metabolism may represent a target for preventive and early disease-modifying interventions in Alzheimer's disease. © 2016 International Society for Neurochemistry.

  19. Optimization of subcritical fluid extraction of bioactive compounds using Hansen solubility parameters.

    PubMed

    Srinivas, K; King, J W; Monrad, J K; Howard, L R; Hansen, C M

    2009-08-01

    Process engineering operations in food and nutraceutical industries pertaining to the design of extraction of value-added products from biomass using pressurized liquids involve a careful selection of the solvent and optimal temperature conditions to achieve maximum yield. Complex molecular structure and limited physical property data in the literature of biological solutes extracted from biomass compounds have necessitated the process modeling of such operations. In this study, we have applied the Hansen 3-dimensional solubility parameter concept to optimize the extraction of molecularly complex solutes using subcritical fluid solvents. Hansen solubility spheres characterized by the relative energy differences (RED) have been used to characterize and quantify the solute-subcritical solvent interactions as a function of temperature. The solvent power of subcritical water and compressed hydroethanolic mixtures above their boiling points has been characterized using the above-mentioned method. The use of group contribution methods in collaboration with computerized algorithms to plot the Hansen spheres provides a quantitative prediction tool for optimizing the design of extraction conditions. The method can be used to estimate conditions for solute-solvent miscibility, an optimum temperature range for conducting extractions under pressurized conditions, and approximate extraction conditions of solutes from natural matrices.

  20. Solubility of Albite + Paragonite +/- Quartz in H2O at 1 GPa, 580° C: Implications for Metamorphic Fluids

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C.

    2003-12-01

    One of the most common mineral assemblages in crustal metamorphism is feldspar + quartz; however, little is known about the solubility of this assemblage in metamorphic fluids. We measured the solubility of albite and albite+quartz in H2O at 580° C and 1.0 GPa using a piston cylinder apparatus. Experiments were conducted using Amelia albite in NaCl-graphite assemblies. Experiments were conducted using a double capsule arrangement. Inner capsules consisting of perforated 1.6 mm OD Pt capsules containing a single albite crystal were load in 3.5mm OD outer capsules containing ultra pure H2O +/- quartz. Solubility was determined by the weight loss of single albite and quartz grains after 8 hr runs. Time series experiments on this system show no variation in fluid composition or solubility after 4hrs. Albite exhibited incongruent dissolution, yielding paragonite as a husk that mantles the albite grain. The composition of the fluid was determined by mass balance as determined by the weights of albite, quartz, and paragonite. In the albite-only experiments, the concentration of total dissolved solids (TDS) were 0.628 molal, with Na, Al and Si in the fluid of 0.137, 0.081, and 0.41 molal, respectively, and Na/Al of 1.691. In the presence of quartz, there is an increase in the overall TDS to 0.777 molal. Albite-quartz experiments produce an increase in Si concentration to 0.628 molal, with lower Na and Al concentrations of 0.098 and 0.051 molal, respectively, and Na/Al of 1.922. The aqueous Si concentrations in the albite-only experiments are higher than those in fluid equilibrated with quartz (Manning, 1994, GCA, 58, 4831) at the same conditions. This is consistent with the data of Anderson and Burnham (1983, Am. J. Sci., 283-A, 283) on albite. In the quartz-present experiments results show still higher Si concentration in the fluid phase. Our results demonstrate enhanced solubility of silica in the presence of albite and albite+quartz, relative to quartz alone

  1. Soluble CD27 Levels in Cerebrospinal Fluid as a Prognostic Biomarker in Clinically Isolated Syndrome.

    PubMed

    van der Vuurst de Vries, Roos M; Mescheriakova, Julia Y; Runia, Tessel F; Jafari, Naghmeh; Siepman, Theodora A M; Hintzen, Rogier Q

    2017-03-01

    There is a growing number of therapies that could be administered after the first symptom of central nervous system demyelination. These drugs can delay multiple sclerosis (MS) diagnosis and slow down future disability. However, treatment of patients with benign course may not be needed; therefore, there is a need for biomarkers to predict long-term prognosis in patients with clinically isolated syndrome (CIS). To investigate whether the T-cell activation marker soluble CD27 (sCD27) measured in cerebrospinal fluid of patients at time of a first attack is associated with a subsequent diagnosis of MS and a higher relapse rate. This prospective study included 77 patients with CIS between March 2002 and May 2015 in a tertiary referral center for multiple sclerosis, in collaboration with several regional hospitals. Patients with CIS underwent a lumbar puncture and magnetic resonance imaging scan within 6 months after first onset of symptoms. Soluble CD27 levels were determined in cerebrospinal fluid using a commercially available enzyme-linked immunosorbent assay. Cox regression analyses was used to calculate univariate and multivariate hazard ratios for MS diagnosis. Association between sCD27 levels and relapse rate was assessed using a negative binomial regression model. Among 77 patients with CIS, 50 were female (79.5%), and mean (SD) age was 32.7 (7.4) years. Mean (SD) age in the control individuals was 33.4 (9.5) years, and 20 were female (66.7%).Patients with CIS had higher cerebrospinal fluid sCD27 levels than control individuals (geometric mean, 31.3 U/mL; 95% CI, 24.0-40.9 vs mean, 4.67 U/mL; 95% CI, 2.9-7.5; P < .001). During a mean (SD) follow-up of 54.8 (35.1) months, 39 of 77 patients (50.6%) were diagnosed as having MS. In a model adjusted for magnetic resonance imaging and cerebrospinal fluid measurements, sCD27 levels were associated with a diagnosis of MS (hazard ratio, 2.4 per 100 U/mL increase in sCD27 levels; 95% CI, 1.27-4.53; P = .007

  2. Statistical investigation of simulated intestinal fluid composition on the equilibrium solubility of biopharmaceutics classification system class II drugs.

    PubMed

    Khadra, Ibrahim; Zhou, Zhou; Dunn, Claire; Wilson, Clive G; Halbert, Gavin

    2015-01-25

    A drug's solubility and dissolution behaviour within the gastrointestinal tract is a key property for successful administration by the oral route and one of the key factors in the biopharmaceutics classification system. This property can be determined by investigating drug solubility in human intestinal fluid (HIF) but this is difficult to obtain and highly variable, which has led to the development of multiple simulated intestinal fluid (SIF) recipes. Using a statistical design of experiment (DoE) technique this paper has investigated the effects and interactions on equilibrium drug solubility of seven typical SIF components (sodium taurocholate, lecithin, sodium phosphate, sodium chloride, pH, pancreatin and sodium oleate) within concentration ranges relevant to human intestinal fluid values. A range of poorly soluble drugs with acidic (naproxen, indomethacin, phenytoin, and piroxicam), basic (aprepitant, carvedilol, zafirlukast, tadalafil) or neutral (fenofibrate, griseofulvin, felodipine and probucol) properties have been investigated. The equilibrium solubility results determined are comparable with literature studies of the drugs in either HIF or SIF indicating that the DoE is operating in the correct space. With the exception of pancreatin, all of the factors individually had a statistically significant influence on equilibrium solubility with variations in magnitude of effect between the acidic and basic or neutral compounds and drug specific interactions were evident. Interestingly for the neutral compounds pH was the factor with the second largest solubility effect. Around one third of all the possible factor combinations showed a significant influence on equilibrium solubility with variations in interaction significance and magnitude of effect between the acidic and basic or neutral compounds. The least number of significant media component interactions were noted for the acidic compounds with three and the greatest for the neutral compounds at seven

  3. Interleukin 2 (IL 2) inhibitor in rheumatoid synovial fluid: Correlation with prognosis and soluble IL 2 receptor levels

    SciTech Connect

    Miossec, P.; Elhamiani, M.; Chichehian, B.; D'Angeac, A.D.; Sany, J.; Hirn, M. )

    1990-03-01

    A soluble activity inhibiting over 50% of the CTLL-2 cell line response to recombinant human interleukin 2 (IL 2) was found in 17 of 29 (59%) rheumatoid synovial fluids. To study the prognosis value of this activity, 16 rheumatoid synovial fluids were collected before a radiation synovectomy of the knee with 7 mCi of 90Y. Patients with a good clinical result after the synovectomy had a lower IL 2 inhibitory activity than those with a bad or incomplete result (P less than 0.01). Levels of inhibitory activity and of soluble IL 2 receptors were correlated with each other and with the response of the synovitis to the radiation synovectomy. These results extend the clinical usefulness of soluble IL 2 receptor measurements and indicate a correlation between the immune activation of the rheumatoid synovitis and its clinical activity.

  4. Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

    NASA Astrophysics Data System (ADS)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-01

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  5. Intraocular soluble intracellular adhesion molecule-1 correlates with subretinal fluid height of diabetic macular edema

    PubMed Central

    Zhu, Dan; Zhu, He; Wang, Chunyan; Yang, Dayong

    2014-01-01

    Objective: To investigate the correlations between aqueous concentrations of vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), soluble intracellular adhesion molecule-1 (sICAM-1) and diabetic macular edema (DME). Materials and Methods: VEGF, MCP-1 and sICAM-1 concentrations in aqueous humor samples of 22 patients with DME and 23 patients with cataract of a control group were measured with solid-phase chemiluminescence immunoassay. Results: Aqueous VEGF (89.2 ± 58.5 pg/ml versus 48.5 ± 27.8 pg/ml, P = 0.006), MCP-1 (684.2 ± 423.4 pg/ml versus 432.4 ± 230.4 pg/ml, P = 0.019) and sICAM-1 (3213.8 ± 2581.6 pg/ml versus 260.2 ± 212.2 pg/ml, P < 0.001) all vary significantly between DME group and control group. Maximum height of submacular fluid measured by Optical coherence tomography (OCT) was significantly associated with aqueous sICAM-1 (r = -0.45, P = 0.034). The maximum height of macular thickness measured by OCT was not significantly associated with either VEGF (P = 0.300), MCP-1 (P = 0.320) or sICAM-1 (P = 0.285). Conclusions: Our results suggest that sICAM-1 may majorly contribute to the formation of subretinal fluid in DME patients and imply that MCP-1 and sICAM-1 may be the potential therapy targets, besides VEGF. PMID:23619489

  6. Role of Phenol-Soluble Modulins in Formation of Staphylococcus aureus Biofilms in Synovial Fluid

    PubMed Central

    Dastgheyb, Sana S.; Villaruz, Amer E.; Le, Katherine Y.; Tan, Vee Y.; Duong, Anthony C.; Chatterjee, Som S.; Cheung, Gordon Y. C.; Joo, Hwang-Soo; Hickok, Noreen J.

    2015-01-01

    Staphylococcus aureus is a leading cause of prosthetic joint infections, which, as we recently showed, proceed with the involvement of biofilm-like clusters that cause recalcitrance to antibiotic treatment. Here we analyzed why these clusters grow extraordinarily large, reaching macroscopically visible extensions (>1 mm). We found that while specific S. aureus surface proteins are a prerequisite for agglomeration in synovial fluid, low activity of the Agr regulatory system and subsequent low production of the phenol-soluble modulin (PSM) surfactant peptides cause agglomerates to grow to exceptional dimensions. Our results indicate that PSMs function by disrupting interactions of biofilm matrix molecules, such as the polysaccharide intercellular adhesin (PIA), with the bacterial cell surface. Together, our findings support a two-step model of staphylococcal prosthetic joint infection: As we previously reported, interaction of S. aureus surface proteins with host matrix proteins such as fibrin initiates agglomeration; our present results show that, thereafter, the bacterial agglomerates grow to extremely large sizes owing to the lack of PSM expression under the specific conditions present in joints. Our findings provide a mechanistic explanation for the reported extreme resistance of joint infection to antibiotic treatment, lend support to the notions that Agr functionality and PSM production play a major role in defining different forms of S. aureus infection, and have important implications for antistaphylococcal therapeutic strategies. PMID:25964472

  7. Rutile Solubility in Supercritical Albite-H2O fluids: Implications for Element Mobility in Subduction Zones

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C. E.

    2006-12-01

    Supercritical fluids with compositions intermediate between H2O and silicate are widely invoked as important transport agents in subduction zones. This proposal is in part motivated by the expectation that such fluids might have greater ability to dissolve and transport key trace elements at high P and T. As a test of this hypothesis, we measured the solubility of rutile (TiO2) in supercritical albite (ab, NaAlSi3O8)-H2O at 900°C, 1.5 GPa, from Xab = 0 to 0.3. At this P and T, rutile has very low solubility in H2O and there is full miscibility between H2O and ab melt. Experiments were conducted in a piston-cylinder apparatus with NaCl-graphite furnaces. In each, a 1.6 mm OD Pt inner capsule with a synthetic rutile crystal was lightly crimped and placed in a 3.5 OD Pt capsule with ultra pure H2O and powdered Amelia albite. Equilibrium was achieved after 4 hrs. Solubility was determined by the weight loss of the rutile grain. Quench textures consistent with supercritical behavior were observed in all runs. Residual corundum is present in the H2O-rich runs, but it decreases with increasing ab concentration. Results show that rutile solubility initially rises sharply with increasing ab concentration from 38 ppm in pure H2O to 739 ppm at Xab =0.05 (44 wt%). With further increase in ab, rutile solubility increases only slightly, to 922 ppm at Xab =0.25 (83 wt%). No significant solubility increase was noted near the critical compositon (~50 wt% ab). Our results show that intermediate fluids do not significantly enhance Ti solubility above dilute silicate-bearing solutions. The presence of residual Al2O3 and the sharp initial rise in rutile solubility at low Xab imply that, by analogy with silicate melts, Ti is present in solution as Na-Ti-O complexes (e.g., Dickenson and Hess, 1985, GCA, 49, 2289). However, the lack of residual corundum at high Xab suggests a transiton to different Ti species, perhaps aqueous NaAlSi3O8-like complexes. Our results give insight into rutile

  8. Cerebrospinal fluid soluble TREM2 is higher in Alzheimer disease and associated with mutation status.

    PubMed

    Piccio, Laura; Deming, Yuetiva; Del-Águila, Jorge L; Ghezzi, Laura; Holtzman, David M; Fagan, Anne M; Fenoglio, Chiara; Galimberti, Daniela; Borroni, Barbara; Cruchaga, Carlos

    2016-06-01

    Low frequency coding variants in TREM2 are associated with increased Alzheimer disease (AD) risk, while loss of functions mutations in the gene lead to an autosomal recessive early-onset dementia, named Nasu-Hakola disease (NHD). TREM2 can be detected as a soluble protein in cerebrospinal fluid (CSF) and plasma, and its CSF levels are elevated in inflammatory CNS diseases. We measured soluble TREM2 (sTREM2) in the CSF of a large AD case-control dataset (n = 180) and 40 TREM2 risk variant carriers to determine whether CSF sTREM2 levels are associated with AD status or mutation status. We also performed genetic studies to identify genetic variants associated with CSF sTREM2 levels. CSF, but not plasma, sTREM2 was highly correlated with CSF total tau and phosphorylated-tau levels (r = 0.35, P < 1×10(-4); r = 0.40, P < 1×10(-4), respectively), but not with CSF Aβ42. AD cases presented higher CSF sTREM2 levels than controls (P = 0.01). Carriers of NHD-associated TREM2 variants presented significantly lower CSF sTREM2 levels, supporting the hypothesis that these mutations lead to reduced protein production/function (R136Q, D87N, Q33X or T66M; P = 1×10(-3)). In contrast, CSF sTREM2 levels were significantly higher in R47H carriers compared to non-carriers (P = 6×10(-3)), suggesting that this variant does not impact protein expression and increases AD risk through a different pathogenic mechanism than NHD variants. In GWAS analyses for CSF sTREM2 levels the most significant signal was located on the MS4A gene locus (P = 5.45 × 10(-07)) corresponding to one of the SNPs reported to be associated with AD risk in this locus. Furthermore, SNPs involved in pathways related to virus cellular entry and vesicular trafficking were overrepresented, suggesting that CSF sTREM2 levels could be an informative phenotype for AD.

  9. Soluble CD163 levels are elevated in cerebrospinal fluid and serum in people with Type 2 diabetes mellitus and are associated with impaired peripheral nerve function.

    PubMed

    Kallestrup, M; Møller, H J; Tankisi, H; Andersen, H

    2015-01-01

    To measure soluble CD163 levels in the cerebrospinal fluid and serum of people with Type 2 diabetes, with and without polyneuropathy, and to relate the findings to peripheral nerve function. A total of 22 people with Type 2 diabetes and 12 control subjects without diabetes were included in this case-control study. Participants with diabetes were divided into those with neuropathy (n = 8) and those without neuropathy (n = 14) based on clinical examination, vibratory perception thresholds and nerve conduction studies. Serum and cerebrospinal fluid soluble CD163 levels were analysed using an enzyme-linked immunosorbent assay. Soluble CD163 levels were significantly higher in the cerebrospinal fluid and serum of the participants with Type 2 diabetes compared with the control participants [cerebrospinal fluid: median (range) 107 (70-190) vs 84 (54-115) μg/l, P < 0.01 and serum: 2305 (920-7060) vs 1420 (780-2740) μg/l, P < 0.01). Cerebrospinal fluid soluble CD163 was positively related to impaired peripheral nerve conduction (nerve conduction study rank score: r = 0.42; P = 0.0497) and there was a trend for higher levels of soluble CD163 in the cerebrospinal fluid and serum in participants with neuropathy than in those without neuropathy [cerebrospinal fluid: median (range) 131 (86-173) vs 101 (70-190) μg/l, P = 0.08 and serum: 3725 (920-7060) vs 2220 (1130-4780), P = 0.06). Cerebrospinal fluid soluble CD163 level is associated with impaired peripheral nerve function. Higher levels of soluble CD163 in people with diabetic polyneuropathy suggest that inflammation plays a role in the development of neural impairment. The relationship between cerebrospinal fluid soluble CD163 level and peripheral nerve conduction indicates that soluble CD163 may be a potential biomarker for the severity of diabetic polyneuropathy. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

  10. Refractive index and solubility control of para-cymene solutions for index-matched fluid-structure interaction studies

    NASA Astrophysics Data System (ADS)

    Fort, Charles; Fu, Christopher D.; Weichselbaum, Noah A.; Bardet, Philippe M.

    2015-12-01

    To deploy optical diagnostics such as particle image velocimetry or planar laser-induced fluorescence (PLIF) in complex geometries, it is beneficial to use index-matched facilities. A binary mixture of para-cymene and cinnamaldehyde provides a viable option for matching the refractive index of acrylic, a common material for scaled models and test sections. This fluid is particularly appropriate for large-scale facilities and when a low-density and low-viscosity fluid is sought, such as in fluid-structure interaction studies. This binary solution has relatively low kinematic viscosity and density; its use enables the experimentalist to select operating temperature and to increase fluorescence signal in PLIF experiments. Measurements of spectral and temperature dependence of refractive index, density, and kinematic viscosity are reported. The effect of the binary mixture on solubility control of Rhodamine 6G is also characterized.

  11. Thermodynamic equilibrium solubility measurements in simulated fluids by 96-well plate method in early drug discovery.

    PubMed

    Bharate, Sonali S; Vishwakarma, Ram A

    2015-04-01

    An early prediction of solubility in physiological media (PBS, SGF and SIF) is useful to predict qualitatively bioavailability and absorption of lead candidates. Despite of the availability of multiple solubility estimation methods, none of the reported method involves simplified fixed protocol for diverse set of compounds. Therefore, a simple and medium-throughput solubility estimation protocol is highly desirable during lead optimization stage. The present work introduces a rapid method for assessment of thermodynamic equilibrium solubility of compounds in aqueous media using 96-well microplate. The developed protocol is straightforward to set up and takes advantage of the sensitivity of UV spectroscopy. The compound, in stock solution in methanol, is introduced in microgram quantities into microplate wells followed by drying at an ambient temperature. Microplates were shaken upon addition of test media and the supernatant was analyzed by UV method. A plot of absorbance versus concentration of a sample provides saturation point, which is thermodynamic equilibrium solubility of a sample. The established protocol was validated using a large panel of commercially available drugs and with conventional miniaturized shake flask method (r(2)>0.84). Additionally, the statistically significant QSPR models were established using experimental solubility values of 52 compounds.

  12. Human and simulated intestinal fluids as solvent systems to explore food effects on intestinal solubility and permeability.

    PubMed

    Stappaerts, Jef; Wuyts, Benjamin; Tack, Jan; Annaert, Pieter; Augustijns, Patrick

    2014-10-15

    The mixed micelles and vesicles present in the intraluminal environment of the postprandial state exhibit suitable solubilizing capacities for lipophilic drugs. This increase in solubility, however, is accompanied by a decrease in the free fraction caused by micellar entrapment of these lipophilic compounds. In this study, both simulated and aspirated human intestinal fluids of fasted and fed state conditions were used to evaluate the influence of food on the intestinal disposition of a series of structurally related β-blockers, with varying logP values. Using the in situ intestinal perfusion technique with mesenteric blood sampling in rats, it was demonstrated that fed state conditions significantly decreased the absorptive flux of the more lipophilic compounds metoprolol, propranolol and carvedilol, whereas the influence on the flux of the hydrophilic β-blocker atenolol was limited. The solubility of BCS class II compound carvedilol was found to increase significantly in simulated and aspirated media of the fed state. Intestinal perfusions using intestinal media saturated with carvedilol, revealed a higher flux in the fasted state compared to the fed state, despite the higher solubility in the fed state. This study underscores the importance of addressing the complex nature of the behavior of compounds in the intraluminal environment in fasted and fed state conditions. Moreover, our data point out the value of studying the effect of food on both solubility and permeability using biorelevant experimental conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Water-soluble metal working fluids additives derived from the esters of acid anhydrides with higher alcohols for aluminum alloy materials.

    PubMed

    Yamamoto, Syutaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short article describes properties of new additives in water-soluble metal working fluids for aluminum alloy materials. Many half esters or diesters were prepared from the reactions of higher alcohols with acid anhydrides. Interestingly, diesters of PTMG (tetrahydrofuran oligomer, MW = 650 and 1000) and polybutylene oxide (MW = 650) with maleic anhydride and succinic anhydride showed both of an excellent anti-corrosion property for aluminum alloy and a good hard water tolerance. The industrial soluble type processing oils including these additives also showed anti-corrosion property and hard water tolerance.

  14. Rutile solubility in NaF–NaCl–KCl-bearing aqueous fluids at 0.5–2.79GPa and 250–650°C

    SciTech Connect

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; Chow, Paul; Xiao, Yuming; Hanchar, John M.; Tschauner, Oliver; Shen, Guoyin

    2016-01-14

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nb and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 degrees C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at similar to 300 degrees C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 degrees C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log D-Zr similar to 10(-25) m(2)/s at 650 degrees C and similar to 10(-30) m(2)/s at 250 degrees C) with diffusion length-scales of <0.2 mu m in rutile for our run durations (<10 h). Hence, the Zr/Ti ratio

  15. Rutile solubility in NaF–NaCl–KCl-bearing aqueous fluids at 0.5–2.79GPa and 250–650°C

    DOE PAGES

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; ...

    2016-01-14

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nbmore » and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 degrees C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at similar to 300 degrees C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 degrees C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log D-Zr similar to 10(-25) m(2)/s at 650 degrees C and similar to 10(-30) m(2)/s at 250 degrees C) with diffusion length-scales of <0.2 mu m in rutile for our run durations (<10 h). Hence, the Zr

  16. Rutile solubility in NaF-NaCl-KCl-bearing aqueous fluids at 0.5-2.79 GPa and 250-650 °C

    NASA Astrophysics Data System (ADS)

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; Chow, Paul; Xiao, Yuming; Hanchar, John M.; Tschauner, Oliver; Shen, Guoyin

    2016-03-01

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nb and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 °C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at ∼300 °C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 °C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log DZr ∼10-25 m2/s at 650 °C and ∼10-30 m2/s at 250 °C) with diffusion length-scales of <0.2 μm in rutile for our run durations (<10 h). Hence, the Zr/Ti ratio of the starting rutile, which was quantified, does not change

  17. The effect of CO2 on the solubility of aqueous chloride fluid in dacite, phonolite, and rhyolite melts

    NASA Astrophysics Data System (ADS)

    Chevychelov, V. Yu.; Korneeva, A. A.; Virus, A. A.; Shapovalov, Yu. B.

    2017-04-01

    The solubility of H2O-CO2-Cl-containing fluids of various concentrations (0, 3, 10, and 23 wt % of HCl and from 0 to 8-15 wt % of CO2) in dacite, phonolite, and rhyolite melts at 1000°C and 200 MPa was studied in experiments. It was shown that the Cl concentration in the melt increased substantially from rhyolite to phonolite and dacite (up to 0.25, 0.85, and 1.2 wt %, respectively). The introduction of CO2 into the system resulted in an increase in the Cl content in the melt composition by 20-25%. One may suppose that Cl reactivity in a fluid increases in the presence of CO2 to cause growth of the Cl content in the melt. The introduction of CO2 into the system considerably affects the content of H2O in aluminosilicate melts as well. Thus, the addition of CO2 decreases the H2O content in the melt by 0.5-1.0 wt %. The decrease in the H2O content in an aluminosilicate melt is probably caused by fluid dilution with CO2 resulting in a decrease in the H2O mole fraction and fugacity in the fluid.

  18. Soluble TLR2 is present in human amniotic fluid and modulates the intraamniotic inflammatory response to infection.

    PubMed

    Dulay, Antonette T; Buhimschi, Catalin S; Zhao, Guomao; Oliver, Emily A; Mbele, Ayanda; Jing, Shichu; Buhimschi, Irina A

    2009-06-01

    TLRs are pattern recognition transmembrane receptors that play key roles in innate immunity. A recently discovered soluble truncated form of TLR2 (sTLR2) acts as a decoy receptor, down-regulating the host inflammatory response to bacteria. To identify the presence and functional role of sTLR2 in modulating the intraamniotic inflammatory response to infection, we studied 109 amniotic fluid samples of women with normal pregnancy outcomes (n = 28) and women with (n = 39) and without (n = 42) intraamniotic infection. We sought to demonstrate a functional role of the amniotic fluid sTLR2 in modulating the TLR2 inflammatory signaling in vitro by using a villous explant system. Two sTLR2 forms were identified, and specificity was confirmed with neutralizing peptides. We showed that sTLR2 is present constitutively in amniotic fluid, its levels are gestational age dependent, and we determined that the sTLR2 quantity and functional engagement modulates the intensity of the intraamniotic inflammation elicited by Gram-positive bacteria. In vitro, we demonstrated that challenging placental villous explants with a specific TLR2 agonist (Pam3Cys) induced a significant cytokine response. Notably, preincubation of the preterm, but not near-term, amniotic fluid with Pam3Cys significantly inhibited the ability of this TLR2 agonist to elicit a cytokine reaction. Moreover, depletion of sTLR2 from preterm amniotic fluid removed its neutralizing property. Monensin significantly diminished sTLR2 immunoreactivity, indicating that sTLR2 is the result of intracellular posttranslational processing of TLR2. We conclude that sTLR2 is part of the amniotic fluid innate immune system and participates in regulating the inflammatory response to microbial pathogens.

  19. Soluble and Catalytically Active Endothelin Converting Enzyme-1 is Present in Cerebrospinal Fluid of Subarachnoid Hemorrhage Patients

    PubMed Central

    Kuruppu, Sanjaya; Chou, Sherry H.-Y.; Feske, Steven K.; Suh, Sarah; Hanchapola, Iresha; Lo, Eng H.; Ning, MingMing; Smith, A. Ian

    2014-01-01

    Endothelin converting Enzyme-1 (ECE-1) is essential for the production of Endothelin-1 (ET-1), which is associated with vasospasm following subarachnoid hemorrhage (SAH). We have previously demonstrated the presence of a catalytically active soluble form of ECE-1 in the media of endothelial cells. We aimed to determine if this form of ECE-1 exists in vivo, in cerebrospinal fluid (CSF) of SAH patients. We examined CSF taken from SAH subjects for the presence of soluble ECE-1 using a bradykinin based quenched fluorescent substrate assay. We obtained further confirmation by characterizing the CSF mediated cleavage products of BigET-1 and BigET18–34 (6 μg/ml) using mass spectrometry. The specificity of cleavage was confirmed using the ECE-1 inhibitor CGS35066 5nmol/L. SAH CSF samples had mean ECE-1 activity of 0.127 ± 0.037 μmols of substrate cleaved/μl of CSF/24 h. The C-terminal peptides generated upon the cleavage of BigET-1 and BigET18–34 were detected 48 h after incubation of these substrates with CSF. Cleavage of these substrates was inhibited by CGS35066. Results of Western blots also produced strong evidence for the presence of truncated soluble ECE-1 in CSF. These results strongly suggest the presence of a truncated but catalytically active form of ECE-1 in the CSF of SAH subjects. Further studies are necessary to determine the biological significance of soluble ECE-1 in CSF of SAH subjects, including an association with vasospasm after SAH. PMID:23816989

  20. Solubility-temperature-salinity diagrams as a means for interpreting fluid-inclusion/mineral-zoning data from the Creede District, Colorado

    SciTech Connect

    Plumlee, G.S.; Hayba, D.O.

    1985-01-01

    Boiling and fluid mixing, which are widely regarded as effective ore-deposition mechanisms, can be differentiated by plotting fluid-inclusion data on temperature (enthalpy)-salinity diagrams. Solubilities of ore and gangue minerals can also be contoured on these diagrams to evaluate the relative chemical effects of mixing and boiling, and thereby reconcile ore-deposition models based on fluid-inclusion data with mineral-zoning patterns. For example, fluid-inclusion data from epithermal vein mineralization at Creede indicate the progressive mixing of metal-bearing brines with overlying ground water. Along this mixing path, solubility contours for sphalerite indicate a change of several orders of magnitude, consistent with the abundant sphalerite found in the northern veins. Temperatures and salinities are as high as 285/sup 0/C and 11.5 wt% NaCl eq. in these sulfide-rich northern veins, but as low as 160-200/sup 0/C and 2-7 wt% NaCl eq. in the barite-rich southern veins. Solubility-temperature-salinity (STS) diagrams show barite solubility changes relatively little at high temperatures and salinities, but drops significantly only at salinities below approx.6 wt% eq. Fluid mixing was the depositional mechanism for barite because most mixing paths cross solubility contours while boiling paths are parallel to them. Thus hot, saline fluids originating in the northern parts of the district deposited mainly sphalerite and galena, but only after significant cooling and dilution did they deposit the large quantities of barite seen in the southern parts of the district. STS diagrams are thus useful for visualizing chemical influences on mineral-zoning patterns and relating mineral solubilities to fluid-inclusion data.

  1. Oxidized As (V) in fore-arc mantle serpentinites: Transfer of fluid-soluble elements from slabs to arc magmas

    NASA Astrophysics Data System (ADS)

    Hattori, K. H.; Takahashi, Y.; Guillot, S.; Johanson, B.

    2004-12-01

    Fluids released from subducting slabs and sediments hydrate the overlying peridotites in mantle wedges. Such hydrated peridotites (serpentinites) are enriched in fluid-soluble elements, although insoluble elements show the refractory geochemical signature. The enrichment pattern of serpentinites is similar to that of arc magmas (Hattori & Guillot, 2003 in Geology). Arsenic is one of the most enriched soluble elements, reaching greater than 1000 times of the primitive mantle value. We examined the speciation and occurrence of As in serpentinites to understand how such a highly mobile element can be transferred from subducting slabs to arc magmas via mantle wedges. Our study used serpentinites associated with the Tso Morari eclogitic rocks in the Indus Suture Zone of Himalaya. They represent the hydrated peridotites at the base of mantle wedge beneath the margin of Eurasia and were exhumed from the depth of about 100 km during the active subduction of the Indian continental margin. The serpentinites are made up of antigorite, chromite, minor talc. It contains As ranging from 6 to 275 ppm and S up to 51 ppm, but most have S below detection limit, 4 ppm. X-ray absorption spectroscopy data show that As is mostly As(V) and combined with oxygen, although Minute grains of As-bearing sulphides and arsenides are identified in samples. The fractions of As(V), calculated from the X-ray absorption near-edge structure, are greater in samples with higher As contents. High proportion of As(V) in the fore-arc mantle serpentinites contasts with high As(III) in the serpentinite at the base of the Nidar ophiolite. The source of As (V) in the serpentinites is most likely As adsorped on Fe- and Mn-oxides in subducted sediments and slabs. It was released during the subduction of slab and sediments at low temperatures, \\< 350° C, and shallow depths, \\< 25 km. Continuous flux of water from slabs at the base of the mantle wedge likely maintained As in oxidized condition. Arsenic in the

  2. Solubility of Anhydrite (CaSO4) in NaCl-H2O Fluids at High T and P

    NASA Astrophysics Data System (ADS)

    Newton, R. C.; Manning, C. E.

    2003-12-01

    Weight losses of single crystals of a very pure natural anhydrite exposed to NaCl solutions of 0-0.3 mol fraction were measured at 600-800 \\deg C and 6-14 kbar. Experimental charges were contained in welded Pt capsules in 1.91 cm-diameter piston-cylinder apparatus with NaCl pressure medium for 5-72 hr. Measurements in initially pure H2O were made with HM, NNO, and MnO2 buffers, as well as without buffering. At 800 \\deg C and 10 kbar, CaSO4 molalities are: MnO2, 0.014 mol/kg H2O; HM, 0.017; NNO, 0.148; and unbuffered, 0.026. Variation in oxygen fugacity thus has a large effect on CaSO4 solubility, increasing with H2S/SO2 in the fluid. Unbuffered (self-buffered) charges gave solubilities much closer to HM than NNO. Melting occurred in the NNO experiment at this P and T. NaCl increases CaSO4 solubility enormously, with m(CaSO4) reaching 5.4, or 23.5 wt. %, at 800 \\deg C, 10 kbar and X(NaCl)=0.3. There is also a very large increase with temperature. Regression of all the data give: log(m-mo) = -1.533 + 0.00291T + (1.441 + 0.00016T)logX(NaCl) + 0.0413(P-10) where mo is molality in pure H2O, P is in kbar, and T is in Kelvins. The very large carrying capacity for sulfate in even mildly saline fluids at high P and T, together with the high oxygen potential generated when these solutions react with FeO in rocks to yield pyrrhotite, indicates that such fluids should be considered as principal agents in S-rich, highly oxidizing processes such as Pinatubo-type volcanic eruptions, certain deep-crustal granulite facies metamorphism, as in Bamble, Norway and Shevaroy Hills, S. India, and the anhydrite-related, oxidized Au ore deposits like Abitibi, Ontario, and Kalgoorlie, Australia.

  3. Soluble L-selectin levels in serum and cerebrospinal fluid in patients with multiple sclerosis and systemic lupus erythematosus.

    PubMed

    Baraczka, K; Pozsonyi, T; Nékám, K; Virányi, M; Seszták, M; Szongoth, M; Jakab, L

    2000-08-01

    Soluble L-selectin (sL-selectin) concentrations were measured in paired samples of serum and cerebrospinal fluid by an ELISA method. Patients with several forms of multiple sclerosis (MS) and systemic lupus erythematosus with central nervous system involvement (SLE-CNS) were investigated. Elevated CSF sL-selectin concentrations were found in patients with SLE-CNS (7.62 +/- 3.31 ng/ml) and with relapsing-remitting form of MS (6.99 +/- 4.72 ng/ml) compared to the control group (4.00 +/- 0.95 ng/ml). The data presented suggest some similarities between inflammatory/immunological events in the central nervous system in patients with SLE-CNS and relapsing-remitting form of MS. Immunological heterogeneity in MS is suspected.

  4. Solubility of Two Root-End Filling Materials over Different Time Periods in Synthetic Tissue Fluid: a Comparative Study

    PubMed Central

    Shojaee, Nooshin Sadat; Sahebi, Safoora; Karami, Elahe; Sobhnamayan, Fereshte

    2015-01-01

    Statement of the Problem Insolubility is an important criterion for an ideal root-end filling material to both prevent any microleakage between the root canal and the periradicular space and provide sealing ability. Purpose Many recent studies have shown that mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) have acceptable sealing ability. The purpose of this in vitro study was to evaluate the solubility of these root-end filling materials. Materials and Method Forty stainless steel ring moulds with an internal diameter of 10±1 mm and a height of 2±0.1 mm were selected. Samples of MTA and CEM were mixed according to the manufacturer’s instructions and inserted into the moulds. The specimens were divided into 4 experimental groups and kept in synthetic tissue fluid (STF) for 2 different time periods (7 and 28 days). The control group contained 8 empty rings. The moulds’ weights were recorded before and after immersion in STF. The changes in the weight of the samples were measured and compared using a two- way ANOVA test at a significance level of 5%. Specimens were evaluated with scanning electron microscopy (SEM) at a magnification of 500×. Results There was no significant difference in weight changes between MTA and CEM samples (p> 0.05). Conclusion MTA and CEM have similar solubility in STF in different time periods. PMID:26331148

  5. Release of a Poorly Soluble Drug from Hydrophobically Modified Poly (Acrylic Acid) in Simulated Intestinal Fluids

    PubMed Central

    Knöös, Patrik

    2015-01-01

    A large part of new pharmaceutical substances are characterized by a poor solubility and high hydrophobicity, which might lead to a difference in drug adsorption between fasted and fed patients. We have previously evaluated the release of hydrophobic drugs from tablets based on Pemulen TR2 and showed that the release can be manipulated by adding surfactants. Here we further evaluate the possibility to use Pemulen TR2 in controlled release tablet formulations containing a poorly soluble substance, griseofulvin. The release is evaluated in simulated intestinal media that model the fasted state (FaSSIF medium) or fed state (FeSSIF). The rheology of polymer gels is studied in separate experiments, in order to gain more information on possible interactions. The release of griseofulvin in tablets without surfactant varied greatly and the slowest release were observed in FeSSIF. Addition of SDS to the tablets eliminated the differences and all tablets showed a slow linear release, which is of obvious relevance for robust drug delivery. Comparing the data from the release studies and the rheology experiment showed that the effects on the release from the different media could to a large extent be rationalised as a consequence of the interactions between the polymer and the surfactants in the media. The study shows that Pemulen TR2 is a candidate for controlled release formulations in which addition of surfactant provides a way to eliminate food effects on the release profile. However, the formulation used needs to be designed to give a faster release rate than the tablets currently investigated. PMID:26473964

  6. THE RELATION OF INFLAMMATION TO THE MOLECULAR STRUCTURE OF CARBON COMPOUNDS SOLUBLE IN THE FLUIDS OF THE BODY.

    PubMed

    OPIE, E L

    1965-04-01

    The peritoneal, like the pleural cavity, gives opportunity to measure with adequate accuracy the activity of inflammatory reactions defined by movement of fluid within the cavity, by migration of leucocytes into it, and by exudation of proteins from the plasma. The activity of inflammatory reactions caused by saccharides or by alcohols that were tested varied in accord with their molecular weight, the osmotic pressure maintained by solutions of corresponding concentration, their boiling point, or by other colligative properties. Blood serum or globulin in the concentration with which it occurs in blood serum injected into the peritoneal cavity caused changes which differed little from those caused by physiological salt solution. Protein with molecular weight as low as that of cytochrome C (12,000) or ovalbumin (45,000) when in dilute solution (1 per cent) were rapidly absorbed, whereas trypsin and chymotrypsin under the same conditions caused very active inflammatory reactions because they set free amino acids and perhaps polypeptides with amino acids in short chains. The activity of inflammatory reactions caused by carbon compounds soluble in body fluids varied in accord with their colligative properties.

  7. Hydrophilic membrane-based humidity control.

    PubMed

    Scovazzo, P; Burgos, J; Hoehn, A; Todd, P

    1998-10-14

    A dehumidification system for low gravity plant growth experiments requires the generation of no free-liquid condensate and the recovery of water for reuse. In the systems discussed in this paper, the membrane is a barrier between the humid air phase and a liquid-coolant water phase. The coolant water temperature combined with a transmembrane pressure differential establishes a water flux from the humid air into the coolant water. Building on the work of others, we directly compared different hydrophilic membranes for humidity control. In a direct comparison of the hydrophilic membranes, hollow fiber cellulose ester membranes were superior to metal and ceramic membranes in the categories of condensation flux per surface area, ease of start-up, and stability. However, cellulose ester membranes were inferior to metal membranes in one significant category, durability. Dehumidification systems using mixed cellulose ester membranes failed after operational times of only hours to days. We propose that the ratio of fluid surface area to membrane material area (approximately = membrane porosity) controls the relative performances among membranes. In addition, we clarified design equations for operational parameters such as the transmembrane pressure differential. This technology has several potential benefits related to earth environmental issues including the minimization of airborne pathogen release and higher energy efficiency in air conditioning equipment. Utilizing these study results, we designed, constructed, and flew on the space shuttle missions a membrane-based dehumidification system for a plant growth chamber.

  8. Hematite solubility in NaCl- and CaSiO3-bearing aqueous fluids at 10 kbar and 800 C

    NASA Astrophysics Data System (ADS)

    Wykes, J. L.; Manning, C. E.

    2005-12-01

    A distinguishing characteristic of arc-related magmas is their high oxidation state, manifest as elevated Fe3+/Fe(total) relative to OIB and MORB. However, there is no consensus on the process and agents responsible for arc-magma oxidation. The subducting slab represents an obvious source of oxidized material, particularly lithologies rich in ferric iron-bearing minerals and sulfates produced through seawater interaction. Fe3+ and SO4}2- represent the most readily available agents for mantle-wedge oxidation. Hydrous fluids and brines equilibrated with these oxidized portions of the slab may be effective oxidizing agents. To assess this possibility, we measured the solubility of hematite in NaCl-H2O fluids at 10 kbar and 800°C. Experiments were conducted in a piston-cylinder apparatus with graphite-NaCl furnace assemblies. Solubility was determined by weight loss of either sintered reagent-grade hematite pellets or rounded specular hematite fragments (1 wt% TiO2). The ultra-fine grained reagent hematite tended to recrystallize during experiments; however, in some cases the final pellets were quite friable, leading to material loss during weighing. These experiments were discounted because their weight changes were spurious. Two methods were employed to control fO2. Either a sealed Mn2O3-filled Pt capsule was run inside the fluid filled outer capsule, buffering at the Mn2O3-Mn3O4 equilibrium, or the outer capsule was packed in MnO2 powder inside the graphite heater assembly, acting as a H2 sink. External MnO2 resulted in some recrystallization of the Pt capsules. However, hematite solubility was identical for both methods, suggesting both techniques control fO2 to a similar degree. The solubility of hematite in H2O-NaCl fluids was measured from 0-72 wt% NaCl. Hematite solubility in pure H2O was 5.5×10-4 molal total Fe, with a detection limit of 8.3×10-5. With increasing NaCl conentration, hematite solubility increased from ~0.001 molal total Fe at 13 wt% NaCl to

  9. Soluble Toll-Like Receptors 2 and 4 in Cerebrospinal Fluid of Patients with Acute Hydrocephalus following Aneurysmal Subarachnoid Haemorrhage

    PubMed Central

    Sokół, Bartosz; Jankowski, Roman; Hołysz, Marcin; Więckowska, Barbara; Jagodziński, Paweł

    2016-01-01

    Background Toll-like receptor (TLR) signalling begins early in subarachnoid haemorrhage (SAH), and plays a key role in inflammation following cerebral aneurysm rupture. Available studies suggest significance of endogenous first-line blockers of a TLR pathway—soluble TLR2 and 4. Methods Eighteen patients with SAH and acute hydrocephalus underwent endovascular coiling and ventriculostomy; sTLR2 and 4 levels were assayed in cerebrospinal fluid (CSF) collected on post-SAH days 0–3, 5, and 10–12. Release kinetics were defined. CSF levels of sTLR2 and 4 were compared with a control group and correlated with the clinical status on admission, the findings on imaging, the degree of systemic inflammation and the outcome following treatment. Results None of study group showed detectable levels of sTLR2 and 4 on post-SAH day 0–3. 13 patients showed increased levels in subsequent samples. In five SAH patients sTLR2 and 4 levels remained undetectable; no distinctive features of this group were found. On post-SAH day 5 the strongest correlation was found between sTLR2 level and haemoglobin level on admission (cc = -0.498, P = 0.037). On post-SAH day 10–12 the strongest correlation was revealed between sTLR2 and treatment outcome (cc = -0.501, P = 0.076). Remaining correlations with treatment outcome, status at admission, imaging findings and inflammatory markers on post-SAH day 5 and 10–12 were negligible or low (-0.5 ≤ cc ≤ 0.5). Conclusions In the majority of cases, rupture of a cerebral aneurysm leads to delayed release of soluble TLR forms into CSF. sTLR2 and 4 seem to have minor role in human post-SAH inflammation due to delayed release kinetics and low levels of these protein. PMID:27223696

  10. Solubility of {sup 238}U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

    SciTech Connect

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-29

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  11. Rutile solubility in H2O-NaAlSi3O8 fluids at High T and P: Implications form HFSE mobility in Subduction zones

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C. E.

    2005-12-01

    The trace element signatures of arc magmas are characterized by HFSE depletion relative to the LILE. Rutile, a common accessory phase in high-pressure assemblages, is an important reservoir for the HFSE and is often invoked to explain the HFSE depletion of arc magmas. This model is in part based on experimental studies, which show that rutile has very low solubility in pure H2O. However, rutile is also a common accessory to eclogite-facies vein assemblages of albite, paragonite and quartz, which likely precipitated from slab-derived fluids. This observation requires either that fluid fluxes were unrealistically high, or that current estimates of Ti solubility are too low. A possible solution to this problem is that dissolved silicate components can enhance Ti solubility via complexing. To test this, we measured the solubility of rutile in H2O-NaAlSi3O8 (albite) bearing fluids at high T and P. Experiments were conducted using a piston-cylinder apparatus with NaCl-graphite furnaces. A single synthetic rutile crystal was loaded into a 1.6 mm OD Pt inner capsule, which was lightly crimped and then placed in a 3.5 OD Pt outer capsule with ultra pure H2O and powdered Amelia albite. Solubility was determined by the weight loss of the rutile grain after 10 hrs. A time series demonstrates that equilibrium is achieved after 8-10 hrs. Preliminary results at 800°C, 1.0 GPa, show that rutile solubility rises with increasing NaAlSi3O8 concentration from 1.15(12) millimolal at 2.18 wt% NaAlSi3O8 to 3.77(13) at 8.80 wt% NaAlSi3O8. Corundum mats + fluid are observed in 3.4-8.80 wt% NaAlSi3O8 and are interpreted to be the result of incongruent dissolution of albite. Quenched melt spheres where observed in an experiment containing ~15 wt% NaAlSi3O8, but not at 8.80 wt%. At 8.80 wt% NaAlSi3O8, rutile solubility is higher by a factor of 6 relative to that in pure H2O. Our results suggest that TiO2 solubility is increased by complexing with Na-Al-Si-bearing fluid components. It has

  12. Soluble leukocyte-Associated Ig-like Receptor-1 in amniotic fluid is of fetal origin and positively associates with lung compliance.

    PubMed

    Houben, Michiel L; Olde Nordkamp, Marloes J M; Nikkels, Peter G J; van der Ent, Cornelis K; Meyaard, Linde; Bont, Louis

    2013-01-01

    The soluble form of the inhibitory immune receptor leukocyte-Associated Ig-like Receptor-1 (sLAIR-1) is present in plasma, urine and synovial fluid and correlates to inflammation. We and others previously showed inflammatory protein expression in normal amniotic fluid at term. We hypothesized that sLAIR-1 is present in amniotic fluid during term parturition and is related to fetal lung function development. sLAIR-1 was detectable in all amniotic fluid samples (n=355) collected during term spontaneous deliveries. First, potential intra-uterine origins of amniotic fluid sLAIR-1 were explored. Although LAIR-1 was expressed on the surface of amniotic fluid neutrophils, LAIR-1 was not secreted upon ex vivo neutrophil stimulation with LPS, or PMA/ionomycin. Cord blood concentrations of sLAIR-1 were fourfold lower than and not related to amniotic fluid concentrations and placentas showed no or only sporadic LAIR-1 positive cells. Similarly, in post-mortem lung tissue of term neonates that died of non-pulmonary disorders LAIR-1 positive cells were absent or only sporadically present. In fetal urine samples, however, sLAIR-1 levels were even higher than in amniotic fluid and correlated with amniotic fluid sLAIR-1 concentrations. Second, the potential relevance of amniotic fluid sLAIR-1 was studied. sLAIR-1 concentrations had low correlation to amniotic fluid cytokines. We measured neonatal lung function in a convenient subset of 152 infants, using the single occlusion technique, at a median age of 34 days (IQR 30-39). The amniotic fluid concentration of sLAIR-1 was independently correlated to airway compliance (ρ=0.29, P=.001). Taken together, we show the consistent presence of sLAIR-1 in amniotic fluid, which originates from fetal urine. Concentrations of sLAIR-1 in amniotic fluid during term deliveries are independent from levels of other soluble immune mediators. The positive association between concentrations of amniotic fluid sLAIR-1 and neonatal lung compliance

  13. Genetic regulation of amniotic fluid TNF-alpha and soluble TNF receptor concentrations affected by race and preterm birth.

    PubMed

    Menon, Ramkumar; Velez, Digna R; Morgan, Nicole; Lombardi, Salvatore J; Fortunato, Stephen J; Williams, Scott M

    2008-10-01

    Racial disparity in spontaneous preterm birth (PTB) between African Americans and Caucasians in the US is unexplained, but is probably related to differences in amniotic fluid (AF) inflammatory cytokine profiles. Therefore, this study analyzed the association of 34 single nucleotide polymorphisms (SNPs) in TNF-alpha and its receptor genes (TNFR1 and TNFR2) with AF TNF-alpha and soluble TNF receptor (R1 and R2) concentrations in PTB. Samples consisted of African American and Caucasian cases (PTB), and controls (term birth) for which both cytokine, and maternal and fetal genotype data were available. Analyses were performed with genotype, case, and maker-status interaction in the model for log transformed cytokine concentrations. In Caucasians, two interactions between genotype and pregnancy outcome associated with cytokine concentrations, whereas 14 gene variants in African Americans showed interactions with pregnancy outcome, and 13 showed association with genetic markers. In conclusion, cytokine concentrations in African American preterm births can be partially explained by interactions between pregnancy outcome, SNPs and infection. This does not appear to be the case in Caucasians. These findings may be important in understanding disparity in rates of PTB between the two populations.

  14. Evaluating Soluble EMMPRIN as a Marker of Disease Activity in Multiple Sclerosis: Studies of Serum and Cerebrospinal Fluid

    PubMed Central

    Kaushik, Deepak K.; Yong, Heather Y. F.; Hahn, Jennifer N.; Silva, Claudia; Casha, Steven; Hurlbert, R. John; Jacques, Francois H.; Lisak, Robert; Khan, Omar; Ionete, Carolina; Larochelle, Catherine; Prat, Alex; Bar-Or, Amit; Yong, V. Wee

    2016-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN, CD147) is an inducer of matrix metalloproteinases and has roles in leukocyte activation and migration. We reported previously that in MS and its animal model, experimental autoimmune encephalomyelitis, cell surface-associated EMMPRIN was significantly elevated in leukocytes around inflammatory perivascular cuffs in the CNS. In this study we report that activated T-cells can secrete soluble form of EMMPRIN (sEMMPRIN) upon activation. As sEMMPRIN is also present in biological fluids, we determined whether sEMMPRIN is altered in the CSF and sera of MS subjects. Sera from individuals without neurological conditions served as controls, while CSFs collected from subjects undergoing discectomy, and without evidence of CNS pathology, were used as a comparator group. We found that serum levels of sEMMPRIN from clinically stable MS patients or other inflammatory conditions did not differ from control subjects. Paired serum and CSF samples demonstrated poor correlation of sEMMPRIN. Interestingly, sEMMPRIN levels were approximately 60% higher in CSFs compared to sera. sEMMPRIN CSF levels were significantly higher in secondary progressive compared to primary progressive subjects. Thus we conclude that measurement of sEMMPRIN in serum is not informative for disease activity in MS. The differential expression of sEMMPRIN in the CSF of primary and secondary progressive MS invites hypotheses of the still undefined roles of EMMPRIN in the CNS. PMID:27727297

  15. Levels of Soluble Receptor for Advanced Glycation End Products in Bronchoalveolar Lavage Fluid in Patients with Various Inflammatory Lung Diseases

    PubMed Central

    Kamo, Tetsuro; Tasaka, Sadatomo; Tokuda, Yuriko; Suzuki, Shoji; Asakura, Takanori; Yagi, Kazuma; Namkoong, Ho; Ishii, Makoto; Hasegawa, Naoki; Betsuyaku, Tomoko

    2015-01-01

    Receptor for advanced glycation end products (RAGE) is a multiligand receptor of S100/calgranulins, high-mobility group box 1, and others, and it is associated with the pathogenesis of various inflammatory and circulatory diseases. The soluble form of RAGE (sRAGE) is a decoy receptor and competitively inhibits membrane-bound RAGE activation. In this study, we measured sRAGE levels in bronchoalveolar lavage fluid (BALF) of 78 patients, including 41 with interstitial pneumonia, 11 with sarcoidosis, 9 with respiratory infection, 7 with ARDS, 5 with lung cancer, and 5 with vasculitis. Among them, sRAGE was detectable in BALF of 73 patients (94%). In patients with ARDS and vasculitis, the sRAGE levels were significantly higher than in the control subjects and those with interstitial pneumonia. The sRAGE levels were positively correlated with total cell counts in BALF and serum levels of surfactant protein-D, lactate dehydrogenase, and C-reactive protein. There was an inverse correlation between PaO2/FIO2 ratio and sRAGE levels. These results indicate that sRAGE in BALF might be considered as a biomarker of lung inflammatory disorders, especially ARDS and vasculitis. PMID:27147899

  16. Characterizing metal(loid) solubility in airborne PM10, PM2.5 and PM1 in Frankfurt, Germany using simulated lung fluids

    NASA Astrophysics Data System (ADS)

    Wiseman, Clare L. S.; Zereini, Fathi

    2014-06-01

    The purpose of this study is to assess the solubility of traffic-related metal(loid)s associated with airborne PM of human health concern, employing a physiologically-based extraction test with simulated lung fluids (artificial lysosomal fluid (ALF) and Gamble's solution). Airborne PM (PM10, PM2.5 and PM1) samples were collected in Frankfurt am Main, Germany, using a high volume sampler. Following extraction of the soluble metal(loid) fractions, sample filters were digested with a high pressure asher. Metal(loid) concentrations (As, Ce, Co, Cr, Cu, Mn, Ni, Pb, Sb, Ti and V) were determined in extracts and digests per ICP-Q-MS. All metal(loid)s occurred at detectable concentrations in the three airborne PM fractions. Copper was the most abundant element in mass terms, with mean concentrations of 105 and 53 ng/m3 in PM10 and PM2.5, respectively. Many of the metal(loid)s were observed to be soluble in simulated lung fluids, with Cu, As, V and Sb demonstrating the highest overall mobility in airborne PM. For instance, all four elements associated with PM10 had a solubility of >80% in ALF (24 h). Clearly, solubility is strongly pH dependent, as reflected by the higher relative mobility of samples extracted with the acidic ALF. Given their demonstrated solubility, this study provides indirect evidence that a number of toxic metal(loid)s are likely to possess an enhanced pulmonary toxic potential upon their inhalation. The co-presence of many toxic elements of concern in airborne PM suggests an assessment of health risk must consider the possible interactive impacts of multi-element exposures.

  17. Nanobiotechnology: Cell Membrane-Based Delivery Systems.

    PubMed

    Zhang, Pengfei; Liu, Gang; Chen, Xiaoyuan

    2017-04-01

    The increasingly rapid pace of research in the field of bioinspired drug delivery systems is revealing the promise of cell membrane-based nanovesicles for biomedical applications. Those cell membrane-based nanoparticles combine the natural functionalities of cell plasma membranes and the bioengineering flexibility of synthetic nanomaterials, and such versatility provides a means of designing exciting new drug formulations for personalized treatment in future nanomedicine.

  18. Amniotic Fluid Soluble HLA-G in Term and Preterm Parturition, and Intra-amniotic Infection/Inflammation

    PubMed Central

    Kusanovic, Juan Pedro; Romero, Roberto; Jodicke, Cristiano; Mazaki-Tovi, Shali; Vaisbuch, Edi; Erez, Offer; Mittal, Pooja; Gotsch, Francesca; Chaiworapongsa, Tinnakorn; Edwin, Sam S.; Pacora, Percy; Hassan, Sonia S.

    2012-01-01

    Objective Circulating soluble HLA-G (sHLA-G) has been associated with pregnancy complications, and determination of sHLA-G concentrations in amniotic fluid (AF) has been reported in normal pregnancies. Our aim was to determine if the AF concentrations of sHLA-G change with advancing gestation, spontaneous labor at term, and in patients with spontaneous preterm labor (PTL) with intact membranes, as well as in those with preterm prelabor rupture of membranes (PROM), in the presence or absence of intraamniotic infection/inflammation (IAI). Study design This cross-sectional study included the following groups: 1) midtrimester (n=55); 2) normal pregnancy at term with (n=50) and without (n=50) labor; 3) spontaneous PTL with intact membranes divided into: a) PTL who delivered at term (n=153); b) PTL who delivered preterm without IAI (n=108); and c) PTL with IAI (n=84); and 4) preterm PROM with (n=46) and without (n=44) IAI. sHLA-G concentrations were determined by ELISA. Non-parametric statistics were used for analysis. Results 1) Among patients with PTL, the median AF sHLA-G concentration was higher in patients with IAI than in those without IAI or women that delivered at term (p<0.001 for both comparisons); 2) Similarly, patients with preterm PROM and IAI had higher median AF sHLA-G concentrations than those without IAI (p=0.004); 3) Among patients with PTL and delivery, those with histologic chorioamnionitis and/or funisitis had a higher median AF sHLA-G concentration than those without histologic inflammation (p<0.001); and 4) The median AF sHLA-G concentration did not change with advancing gestational age. Conclusions AF sHLA-G concentrations are elevated in preterm parturition associated to IAI as well as in histologic chorioamnionitis. We propose that sHLA-G may participate in the regulation of the host immune response against intra-amniotic infection. PMID:19916713

  19. The effect of CO2 and N2 on phase relations, fluid composition, and quartz solubility in amphibolite facies metamorphic rocks

    NASA Astrophysics Data System (ADS)

    Artimenko, Margaret V.

    2016-12-01

    Phase equilibria in the system SiO2-TiO2-Al2O3-Fe2O3-MnO-MgO-CaO-Na2O-K2O-P2O5-H2O-CO2-N2 are calculated to illustrate phase relations in amphibolite facies metasediments over a wide range of X[H2O-CO2-N2] conditions at 600 °C and 4.4 kb. Calculations are performed using the Gibbs free energy minimization technique. Results are presented in plots showing stable mineral assemblages as a function of total carbon in the system at varying water (a_{{{{H}}2 {{O}}}} = 1) content in the presence/absence of N2 in the fluid. The calculations indicate that the typical assemblage plagioclase—quartz—biotite—ilmenite—garnet—apatite is restricted to the rocks with CO2 saturation and X_{{{{H}}_{ 2} {{O}}}} higher than 60% in the fluid. Significant decrease in X_{{{{CO}}2 }} favors the stability of muscovite rather than garnet, whereas the decrease in X_{{{{H}}_{ 2} {{O}}}} leads to the stability of microcline over all range of X_{{{{CO}}2 }}. This paper also presents the composition and parameters (pH, Eh) of the fluid equilibrated with mineral assemblage. It is shown that the presence of low concentrations of N2 causes the fluid to consist of two phases when an aqueous supercritical solution (AS) coexists with a supercritical fluid with gas-like properties (SF). At high concentration of N2, the fluid consists of SF alone; in the absence of nitrogen, the fluid consists of AS alone. The solubility of monomer SiO 2 0 and dimer Si2O 4 0 decreases with increasing CO2 and after CO2 saturation point is held constant. The magnitude of the silica solubility at CO2 saturation depends upon the water content in AS. The effect of nitrogen on quartz solubility has been demonstrated to be negligible.

  20. Molecular dynamics simulation of gaseous-liquid phase transitions of soluble and insoluble surfactants at a fluid interface

    NASA Astrophysics Data System (ADS)

    Tomassone, M. S.; Couzis, A.; Maldarelli, C. M.; Banavar, J. R.; Koplik, J.

    2001-11-01

    Molecular dynamics simulations are used to study the formation of gaseous and liquid expanded phases of surfactants on a liquid/vapor interface. Both insoluble and soluble surfactants are considered, modeled as freely jointed chains in a monatomic solvent with appropriate Lennard-Jones interactions. For both insoluble and soluble cases our results indicate that the surface tension as a function of coverage shows a plateau close to the clean interface value until a critical surface concentration, beyond which the surface tension lowers steeply. For the soluble case, we also detail a complete Gibbs construction for the surface excess and report an adsorption isotherm. Snapshots of the positions of the molecules, together with analysis of correlation functions, show that these model surfactants assemble from solution and exhibit coexistence in the plateau of isolated surfactants and liquid aggregates. We have identified this coexistence as a gas-liquid phase transition, in agreement with recent experimental evidence in the soluble case.

  1. Ex vivo permeability experiments in excised rat intestinal tissue and in vitro solubility measurements in aspirated human intestinal fluids support age-dependent oral drug absorption.

    PubMed

    Annaert, Pieter; Brouwers, Joachim; Bijnens, Ann; Lammert, Frank; Tack, Jan; Augustijns, Patrick

    2010-01-31

    The possible influence of advanced age on intestinal drug absorption was investigated by determining the effects of aging on (i) solubility of model drugs in human intestinal fluids (HIF) obtained from two age groups (18-25 years; 62-72 years); and (ii) transepithelial permeation of model drugs across intestinal tissue excised from young, adult and old rats. Average equilibrium solubility values for 10 poorly soluble compounds in HIF aspirated from both age groups showed high interindividual variability, but did not reveal significant differences. Characterization of the HIF from both age groups demonstrated comparable pH profiles, while concentrations of individual bile salts showed pronounced variability between individuals, however without statistical differences between age groups. Transepithelial permeation of the transcellular probe metoprolol was significantly increased in old rats (38 weeks) compared to the younger age groups, while the modulatory role of P-glycoprotein in transepithelial talinolol transport was observed in adult and old rats but not in young rats. In conclusion, age-dependent permeability of intestinal tissue (rather than age-dependent luminal drug solubility) may contribute to altered intestinal drug absorption in older patients compared to young adults.

  2. Modeling of the solubility of a one-component H2O or CO2 fluid in silicate liquids

    NASA Astrophysics Data System (ADS)

    Papale, Paolo

    The modeling of the solubility of water and carbon dioxide in silicate liquids (flash problem) is performed by assuming mechanical, thermal, and chemical equilibrium between the liquid magma and the gas phase. The liquid phase is treated as a mixture of ten silicate components+H2O or CO2, and the gas phase as a pure H2O or CO2. A general model for the solubility of a volatile component in a liquid is adopted. This requires the definition of a mixing equation for the excess Gibbs free energy of the liquid phase and an appropriate reference state for the dissolved volatile. To constrain the model parameters and identify the most appropriate form of the solubility equations for each dissolved volatile, a large number of experimental solubility determinations (640 for H2O and 263 for CO2) have been used. These determinations cover a large region of the P-T-composition space of interest. The resultant water and carbon dioxide solubility models differ in that the water model is regular and isometric, and the carbon dioxide model is regular and non-isometric. This difference is consistent with the different speciation modalities of the two volatiles in the silicate liquids, producing a composition-independent partial molar volume of dissolved water and a composition-dependent partial molar volume of dissolved carbon dioxide. The H2O solubility model may be applied to natural magmas of virtually any composition in the P-T range 0.1 MPa-1 GPa and > 1000 K, whereas the CO2 solubility model may be applied to several GPa pressures. The general consistency of the water solubility data and their relatively large number as compared to the calibrated model parameters (11) contrast with the large inconsistencies of the carbon dioxide solubility determinations and their low number with respect to the CO2 model parameters (22). As a result, most of the solubility data in the database are reproduced within 10% of approximation in the case of water, and 30% in the case of carbon

  3. Nanofibrous membrane-based absorption refrigeration system

    SciTech Connect

    Isfahani, RN; Sampath, K; Moghaddam, S

    2013-12-01

    This paper presents a study on the efficacy of highly porous nanofibrous membranes for application in membrane-based absorbers and desorbers. Permeability studies showed that membranes with a pore size greater than about one micron have a sufficient permeability for application in the absorber heat exchanger. Membranes with smaller pores were found to be adequate for the desorber heat exchanger. The membranes were implemented in experimental membrane-based absorber and desorber modules and successfully tested. Parametric studies were conducted on both absorber and desorber processes. Studies on the absorption process were focused on the effects of water vapor pressure, cooling water temperature, and the solution velocity on the absorption rate. Desorption studies were conducted on the effects of wall temperature, vapor and solution pressures, and the solution velocity on the desorption rate. Significantly higher absorption and desorption rates than in the falling film absorbers and desorbers were achieved. Published by Elsevier Ltd.

  4. Relation of soluble RANKL and osteoprotegerin levels in blood and gingival crevicular fluid to the degree of root resorption after orthodontic tooth movement.

    PubMed

    Tyrovola, Joanna B; Perrea, Despoina; Halazonetis, Dimitrios J; Dontas, Ismene; Vlachos, Ioannis S; Makou, Margarita

    2010-06-01

    The aim of the present study was the determination of the levels of osteoprotegerin and soluble RANKL in blood serum and in gingival crevicular fluid relative to the degree of orthodontic root resorption in a rat model. Blood samples and gingival crevicular fluid were collected from fourteen 6-month-old male Wistar rats weighing 350-500 g. A 25-g closed orthodontic coil spring was inserted between each upper right first molar and the upper incisors. After 21 days of loading, both upper first molars (treated and control) were extracted and studied under microcomputed tomography scanning. Statistical analysis demonstrated a positive linear correlation between the initial concentration of RANKL in blood serum and the degree of root resorption. The ratio of the initial concentrations of osteoprotegerin to RANKL in blood serum proved to be an independent prognostic factor of the degree of root resorption. The initial concentration of RANKL in gingival crevicular fluid showed a negative correlation to the initial concentration of RANKL in blood serum and for a finite range of initial concentrations of osteoprotegerin in gingival crevicular fluid, the dental root seemed protected against extreme external root resorption. Finally, the concentration of osteoprotegerin in blood serum decreased significantly in cases of severe root resorption.

  5. Solubility of aliphatic hydrocarbons in piperidinium ionic liquids: measurements and modeling in terms of perturbed-chain statistical associating fluid theory and nonrandom hydrogen-bonding theory.

    PubMed

    Paduszyński, Kamil; Domańska, Urszula

    2011-11-03

    Ionic liquids (ILs) reveal many unique properties which make them very interesting for applications in modern "green" technologies. For that reason, detailed knowledge about correlations between the ions' structure, their combinations, and the bulk properties is of great importance. That knowledge can be accessed by reliable measurements and modeling of systems with ILs in terms of various theoretical approaches. In this paper we report new experimental results on liquid-liquid equilibrium (LLE) measurements of 10 binary systems composed of piperidinium ILs [namely, 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide] and aliphatic hydrocarbons (n-hexane, n-heptane, n-octane, cyclohexane, and cycloheptane). Moreover, new results on liquid density of pure 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide are presented. Upper critical solution temperature type of phase behavior for all studied systems was observed. Decrease of solubility of n-alkane with an increase of its alkyl chain length and increase of solubility when changing linear into cyclic structure of hydrocarbon were detected. LLE modeling of investigated systems was performed in terms of two modern theories, namely, perturbed-chain statistical associating fluid theory (PC-SAFT) and nonrandom hydrogen-bonding theory (NRHB). Pure fluid parameters of the models were obtained from fitting of experimental liquid density and solubility parameter data at ambient pressure and tested against high pressure densities. Then literature values of activity coefficients of n-alkanes and cycloalkanes at infinitely diluted mixtures with ILs were used to optimize binary interaction parameters of the models. Finally, the LLE phase diagrams were calculated with average absolute relative deviations of 4.1% and 3.4% of the IL mole fraction for PC-SAFT and NRHB, respectively. The PC-SAFT and NRHB models were both able to capture phase

  6. Mutual Solubility Study in Supercritical Fluid Extraction of Tocopherols from Crude Palm Oil Using CO2 Solvent

    PubMed Central

    Davarnejad, Reza; Ahmad, Zainal; Sata, Suhairi A.; Moraveji, Mostafa Keshavarz; Ahmadloo, Farzaneh

    2010-01-01

    In this article, the mutual solubility of tocopherols from crude palm oil was studied using carbon dioxide as a solvent at the temperatures of 80, 100 and 120 °C. Each sample from the phase equilibrium unit contained two parts. The liquid part was analyzed by gas chromatography (GC) in order to measure the tocopherol composition and, on the other hand, the vapor phase was conducted in an expansion vessel in order to measure the pressure increment during the expansion process. Two phase equilibrium data was calculated using the liquid phase composition and pressure increments during the expansion process. Results showed that the maximum solubility of tocopherols was around 2.27% at a temperature of 120 °C and at pressure of 5.44 MPa. PMID:21152291

  7. Solubility of quartz in H2O-KOH solutions at 700°C and 1 GPa: implications for aqueous silica species in alkaline high pressure fluids

    NASA Astrophysics Data System (ADS)

    Wang, S.; Makhluf, A.; Manning, C. E.

    2016-12-01

    At deep-crustal and subduction-zone conditions, thermodynamic models show that water-rich fluids equilibrated with common crustal rocks have pH values that are commonly alkaline (e.g., Galvez et al., 2105, EPSL, 430, 486). This raises the possibility that one of the most abundant solutes in these fluids, aqueous silica, may be dominated by the deprotonated species HSiO3-, which is comparatively rare at near-surface conditions. However, the thermodynamic properties of this species are very poorly known. We conducted hydrothermal piston cylinder experiments on quartz solubility in H2O-KOH solutions. All experiments were carried out at 700 °C and 1 GPa, using weight-loss methods and solutions ranging from pure H2O to 2.1 molal total KOH ([Ktotal]. Quartz solubility ([Sitotal]) in pure H2O was found to be 0.730 molal, consistent with previous experimental work but slightly higher than the value of 0.621 m predicted by the Deep Earth Water model (DEW; Sverjensky et al., 2014, GCA, 129, 125). The value of [Sitotal] remains constant with increasing K concentration to [Ktotal] 10-2 m, above which [Sitotal] rises dramatically to 4.6 m at the highest [Ktotal]. The rise in Si concentration in part signals the increasing concentration of Si anions, here provisionally assumed to be limited to monomeric HSiO3-. We combined our experimental results with thermodynamic data for quartz solubility in H2O and silica polymerization from Manning (2007, Geofluids, 7, 258) to evaluate the equilibrium constant (K) for the reaction SiO2aq + H2O = H+ + HSiO3- at 700 °C and 1 GPa, where SiO2aq refers to the neutral monomer. The data require a value of logK > -6, which is significantly greater than the value -8.7 implied by experimental data at lower P. This would require that the standard molal Gibbs free energy of HSiO3- is substantially less negative than currently thought; however, it also likely requires the presence of neutral KHSiO3 ion pairs, for which no data currently exist. A key

  8. The speciation of soluble sulphur compounds in bacterial culture fluids by X-ray absorption near edge structure spectroscopy.

    PubMed

    Franz, Bettina; Lichtenberg, Henning; Hormes, Josef; Dahl, Christiane; Prange, Alexander

    2009-11-01

    Over the last decade X-ray absorption near edge structure (XANES) spectroscopy has been used in an increasing number of microbiological studies. In addition to other applications it has served as a valuable tool for the investigation of the sulphur globules deposited intra- or extracellularly by certain photo- and chemotrophic sulphur-oxidizing (Sox) bacteria. For XANES measurements, these deposits can easily be concentrated by filtration or sedimentation through centrifugation. However, during oxidative metabolism of reduced sulphur compounds, such as sulphide or thiosulphate, sulphur deposits are not the only intermediates formed. Soluble intermediates such as sulphite may also be produced and released into the medium. In this study, we explored the potential of XANES spectroscopy for the detection and speciation of sulphur compounds in culture supernatants of the phototrophic purple sulphur bacterium Allochromatium vinosum. More specifically, we investigated A. vinosum DeltasoxY, a strain with an in frame deletion of the soxY gene. This gene encodes an essential component of the thiosulphate-oxidizing Sox enzyme complex. Improved sample preparation techniques developed for the DeltasoxY strain allowed for the first time not only the qualitative but also the quantitative analysis of bacterial culture supernatants by XANES spectroscopy. The results thus obtained verified and supplemented conventional HPLC analysis of soluble sulphur compounds. Sulphite and also oxidized organic sulphur compounds were shown by XANES spectroscopy to be present, some of which were not seen when standard HPLC protocols were used.

  9. A soluble, high-affinity, interleukin-4-binding protein is present in the biological fluids of mice

    SciTech Connect

    Fernandez-Botran, R.; Vitetta, E.S. )

    1990-06-01

    Cytokines such as interleukin 4 (IL-4) play a key role in the regulation of immune responses, but little is known about how their multiple activities are regulated in vivo. In this report, we demonstrate that an IL-4-binding protein (IL-4BP) is constitutively present in the biological fluids of mice (serum, ascites fluid, and urine). Binding of {sup 125}I-labeled IL-4 to the IL-4BP is specific and saturable and can be inhibited by an excess of unlabeled IL-4 but not IL-2. The IL-4BP binds IL-4 with an affinity similar to that reported for the cellular IL-4 with an affinity similar to that reported for the cellular IL-4 receptor (K{sub d} {approx}7 {times} 10{sup {minus}11} M) and has a molecular mass of 30-40 kDa and pI values of 3.6-4.8. IL-4BP-containing biological fluids or purified IL-4BP competitively inhibit the binding of {sup 125}I-labeled IL-4 to mouse T or B cells and inhibit the biological activity of IL-4 but not IL-2. The serum levels of IL-4BP in severe combined immunodeficiency (SCID) mice are lower than those of normal mice. The above findings suggest that IL-4BP plays an important immunoregulatory role in vivo.

  10. Development of a validated liquid chromatography method for the simultaneous determination of eight fat-soluble vitamins in biological fluids after solid-phase extraction.

    PubMed

    Chatzimichalakis, Pavlos F; Samanidou, Victoria F; Papadoyannis, Ioannis N

    2004-06-15

    In the present study, a simple and rapid reversed-phase HPLC procedure has been developed for the simultaneous determination of eight fat-soluble vitamins (retinol, menadione, menaquinone, delta-tocopherol, cholecalciferol, alpha-tocopherol, alpha-tocopherol acetate and phylloquinone) in biological fluids: blood serum and urine. The analytical column, Phenomenex Luna C18 (150 mm x 4.6 mm) 3 microm, was operating at ambient temperature. Mobile phase consisted of a mixture of CH3OH-CH3CN delivered using a linear gradient, starting with a composition of 50-50% v/v and ending at 30-70% at a flow rate of 1.3 ml/min. Xanthophyll was used as internal standard (2 ng/microl). Detection and identification was performed using a photodiode array detector. Eluent monitoring was achieved at 280 nm for vitamins and 450 nm for the internal standard. However, quantitation was performed at maximum wavelength for each vitamin. Detection limits were found in the range of 1.4-6.6 ng per 20-microl injected samples, while linearity held up to 25 ng/microl. The statistical evaluation of the method was examined performing intra-day (n = 6) and inter-day calibration (n = 7) and was found to be satisfactory, with high accuracy and precision results. The biological fluids were treated using solid-phase extraction cartridges, to remove all endogenous interferences from sample matrix. The solid-phase extraction protocol was optimized in terms of retention and elution. High extraction recoveries from biological matrices: blood serum and urine, (average recovery ranging between 95 and 97.6% for blood serum and between 94.2 and 95.8% for urine) were achieved for the eight fat-soluble vitamins, using Cyclohexyl J.T. Baker SPE cartridges with methanol as eluent, requiring small volumes, 100 microl of blood serum and 100 microl of urine.

  11. Solubility of uranium and thorium from a healing earth in synthetic gut fluids: a case study for use in dose assessments.

    PubMed

    Höllriegl, Vera; Li, Wei Bo; Leopold, Karsten; Gerstmann, Udo; Oeh, Uwe

    2010-11-01

    The aim of this case study was to estimate the bioaccessibility of uranium ((238)U) and thorium ((232)Th) from a healing earth by analysing the solubility of these radionuclides in synthetic gastric and intestinal fluids. An easy applicable in vitro test system was used to investigate the fractional mobilization of the soil contaminants being potentially available for absorption under human in vivo conditions. These findings provided the basis for a prospective dose assessment. The solubility experiments were performed using two different in vitro digestion methods. The concentrations of (238)U and (232)Th in the solutions extracted from the soil were measured by inductively coupled plasma mass spectrometry (ICP-MS). The dissolved fractions in the synthetic gastrointestinal fluid ranged in average from 10.3% to 13.8% for (238)U and from 0.3% to 1.6% for (232)Th, respectively, depending on the digestion method. Subsequently, the committed effective doses from intake of (238)U and (232)Th after ingestion of the healing earth during 1 year were evaluated for adult persons. Thereby ingestion dose coefficients calculated as a function of bioaccessibility were used. The dose assessments ranged between 4.3 × 10(-7)-1.9 × 10(-6) Sv y(-1) for (238)U and 5.6 × 10(-7)-3.3 × 10(-6) Sv y(-1) for (232)Th, respectively. On the basis of the assumptions and estimations made, the present work indicates a relatively low radiation risk due to (238)U and (232)Th after internal exposure of the healing earth.

  12. Novel spray freeze-drying technique using four-fluid nozzle-development of organic solvent system to expand its application to poorly water soluble drugs.

    PubMed

    Niwa, Toshiyuki; Shimabara, Hiroko; Danjo, Kazumi

    2010-02-01

    Spray freeze-drying (SFD) technique using four-fluid nozzle (4N), which is a novel particle design technique previously developed by authors, has been further developed to expand its application in pharmaceutical industry. The organic solvent was utilized as a spray solvent to dissolve the poorly soluble drug instead of conventional aqueous solution. Acetonitrile solution of the drug and aqueous solution of the polymeric carrier were separately and simultaneously atomized through 4N, and collided each other at the tip of nozzle edge. The spray mists were immediately frozen in the liquid nitrogen to form a suspension. Then, the iced droplets were freeze-dried to prepare the composite particles of the drug and carrier according to our proprietary method developed before. The resultant composite particles with phenytoin prepared by using acetonitrile (4N-SFD-MeCN system) were deeply characterized compared to those using aqueous solution (4N-SFD-aqua system) from morphological and physicochemical perspectives. The characteristic porous structure was observed in 4N-SFD-MeCN particles as well as 4N-SFD-aqua particles. However, it was found that the size and quantity of pore in 4N-SFD-MeCN particles were smaller than those of 4N-SFD-aqua particles. As a result, the former particles had 2- to 3-times smaller specific surface area than the latter particles independent of the type of carrier loaded. The slight difference of release profiles from the particles prepared between both systems was discussed from the microscopically structural viewpoint. In addition, ciclosporin was applied to organic solvent SFD system because this drug was poorly water soluble and cannot be applied to conventional aqueous SFD system. The release profiles from SFD particles were dramatically improved compared to the bulk material, suggesting that the new SFD technique using organic solvent has potential to develop the novel solubilized formulation for poorly water-soluble active pharmaceutical

  13. Original research paper. A superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes with improved solubility and dissolution: Supercritical fluid process.

    PubMed

    Pan, Hao; Wang, Han-Bing; Yu, Yi-Bin; Cheng, Bing-Chao; Wang, Xiao-Yu; Li, Ying

    2017-03-01

    Advantages of the supercritical fluid (SCF) process compared to the conventional solution stirring method (CSSM) in the preparation of daidzein-hydroxypropyl-β-cyclodextrin (HPβCD) complexes were investigated. Formation of daidzein/ HPβCD inclusion complexes was confirmed by Fourier transformed-infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Particle size, inclusion yield, drug solubility and dissolution of daidzein/HPβCD complexes were evaluated. Compared to CSSM, the SCF process resulted in higher inclusion yield and higher solubility. Also, extended dissolution of daidzein from the SCF processed HPβCD inclusion complexes was observed, with only 22.94 % released in 45 min, compared to its rapid release from those prepared by CSSM, with 98.25 % drug release in 15 min. This extended release of daidzein from SCF prepared inclusion complexes was necessary to avoid drug precipitation and improve drug solubilisation in the gastrointestinal tract. The results showed that the SCF process is a superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes.

  14. A review of chromatographic methods for the determination of water- and fat-soluble vitamins in biological fluids.

    PubMed

    Karaźniewicz-Łada, Marta; Główka, Anna

    2016-01-01

    Vitamins are an essential element of nutrition and thus contribute to human health. Vitamins catalyze many biochemical reactions and their lack or excess can cause health problems. Therefore, monitoring vitamin concentrations in plasma or other biological fluids may be useful in the diagnosis of various disorders as well as in the treatment process. Several chromatographic methods have been developed for the determination of these compounds in biological samples, including high-performance liquid chromatography with UV and fluorescence detection. Recently, high-performance liquid chromatography with tandem mass spectrometry methods have been widely used for the determination of vitamins in complex matrices because of their high sensitivity and selectivity. This method requires preconditioning of samples for analysis, including protein precipitation and/or various extraction techniques. The choice of method may depend on the desired cost, convenience, turnaround time, specificity, and accuracy of the information to be obtained. This article reviews the recently reported chromatographic methods used for determination of vitamins in biological fluids. Relevant papers published mostly during the last 5 years were identified by an extensive PubMed search using appropriate keywords. Particular attention was given to the preparation steps and extraction techniques. This report may be helpful in the selection of procedures that are appropriate for certain types of biological materials and analytes.

  15. Simultaneous analysis for water- and fat-soluble vitamins by a novel single chromatography technique unifying supercritical fluid chromatography and liquid chromatography.

    PubMed

    Taguchi, Kaori; Fukusaki, Eiichiro; Bamba, Takeshi

    2014-10-03

    Chromatography techniques usually use a single state in the mobile phase, such as liquid, gas, or supercritical fluid. Chromatographers manage one of these techniques for their purpose but are sometimes required to use multiple methods, or even worse, multiple techniques when the target compounds have a wide range of chemical properties. To overcome this challenge, we developed a single method covering a diverse compound range by means of a "unified" chromatography which completely bridges supercritical fluid chromatography and liquid chromatography. In our method, the phase state was continuously changed in the following order; supercritical, subcritical and liquid. Moreover, the gradient of the mobile phase starting at almost 100% CO2 was replaced with 100% methanol at the end completely. As a result, this approach achieved further extension of the polarity range of the mobile phase in a single run, and successfully enabled the simultaneous analysis of fat- and water-soluble vitamins with a wide logP range of -2.11 to 10.12. Furthermore, the 17 vitamins were exceptionally separated in 4min. Our results indicated that the use of dense CO2 and the replacement of CO2 by methanol are practical approaches in unified chromatography covering diverse compounds. Additionally, this is a first report to apply the novel approach to unified chromatography, and can open another door for diverse compound analysis in a single chromatographic technique with single injection, single column and single system.

  16. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory†

    PubMed Central

    Mohammad, Sultan; Schleinitz, Miko; Coutinhoa, João A. P.; Freire, Mara G.

    2016-01-01

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg−1). At salt molalities higher than 0.2 mol kg−1, all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.20 mol kg−1. To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K+ and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K+/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid–liquid phase behaviour. PMID:26575280

  17. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory.

    PubMed

    Neves, Catarina M S S; Held, Christoph; Mohammad, Sultan; Schleinitz, Miko; Coutinho, João A P; Freire, Mara G

    2015-12-21

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg(-1)). At salt molalities higher than 0.2 mol kg(-1), all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.2 mol kg(-1). To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K(+) and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K(+)/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid-liquid phase behaviour.

  18. Significant Solubility of Carbon dioxide in Soluplus® Facilitates Impregnation of Ibuprofen Using Supercritical Fluid Technology.

    PubMed

    Obaidat, Rana; Alnaief, Mohammed; Jaeger, Philip

    2017-04-04

    Treatment of Soluplus® with supercritical carbon dioxide allows promising applications in preparing dispersions of amorphous solids. Several characterization techniques ware employed to reveal this effect, including CO2 gas sorption under high pressure and physicochemical characterizations techniques. A gravimetric method was used to determine the solubility of carbon dioxide in the polymer at elevated pressure. The following physicochemical characterizations were used: thermal analysis, X-ray diffraction, Fourier transform, infra-red spectroscopy and scanning electron microscopy. Drug loading of the polymer with ibuprofen as a model drug was also investigated. The proposed treatment with supercritical carbon dioxide allows to prepare solid solutions of Soluplus® in less than two hours at temperatures that do not exceed 45°C, which is a great advantage to be used for thermolabile drugs. The advantages of using this technology for Soluplus® formulations lies behind the high sorption capability of carbon dioxide inside the polymer. This will ensure rapid diffusion of the dissolved/dispersed drug inside the polymer under process conditions and rapid precipitation of the drug in the amorphous form during depressurization accompanied by foaming of the polymer.

  19. Membrane-based wet electrostatic precipitation

    SciTech Connect

    David J. Bayless; Liming Shi; Gregory Kremer; Ben J. Stuart; James Reynolds; John Caine

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or waterbased) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at First Energy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with {approximately}15% less collecting area. 15 refs., 7 figs., 6 tabs.

  20. Membrane-based wet electrostatic precipitation.

    PubMed

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  1. Lumbar Cerebrospinal Fluid Biomarkers of Posthemorrhagic Hydrocephalus of Prematurity: Amyloid Precursor Protein, Soluble Amyloid Precursor Protein α, and L1 Cell Adhesion Molecule.

    PubMed

    Morales, Diego M; Silver, Shawgi A; Morgan, Clinton D; Mercer, Deanna; Inder, Terri E; Holtzman, David M; Wallendorf, Michael J; Rao, Rakesh; McAllister, James P; Limbrick, David D

    2017-01-01

    Intraventricular hemorrhage (IVH) is the most frequent, severe neurological complication of prematurity and is associated with posthemorrhagic hydrocephalus (PHH) in up to half of cases. PHH requires lifelong neurosurgical care and is associated with significant cognitive and psychomotor disability. Cerebrospinal fluid (CSF) biomarkers may provide both diagnostic information for PHH and novel insights into its pathophysiology. To explore the diagnostic ability of candidate CSF biomarkers for PHH. Concentrations of amyloid precursor protein (APP), soluble APPα (sAPPα), soluble APPβ, neural cell adhesion molecule-1 (NCAM-1), L1 cell adhesion molecule (L1CAM), tau, phosphorylated tau, and total protein (TP) were measured in lumbar CSF from neonates in 6 groups: (1) no known neurological disease (n = 33); (2) IVH grades I to II (n = 13); (3) IVH grades III to IV (n = 12); (4) PHH (n = 12); (5) ventricular enlargement without hydrocephalus (n = 10); and (6) hypoxic ischemic encephalopathy (n = 13). CSF protein levels were compared using analysis of variance, and logistic regression was performed to examine the predictive ability of each marker for PHH. Lumbar CSF levels of APP, sAPPα, L1CAM, and TP were selectively increased in PHH compared with all other conditions (all P < .001). The sensitivity, specificity, and odds ratios of candidate CSF biomarkers for PHH were determined for APP, sAPPα, and L1CAM; cut points of 699, 514, and 113 ng/mL yielded odds ratios for PHH of 80.0, 200.0, and 68.75, respectively. Lumbar CSF APP, sAPPα, L1CAM, and TP were selectively increased in PHH. These proteins, and sAPPα, in particular, hold promise as biomarkers of PHH and provide novel insight into PHH-associated neural injury and repair.

  2. A membrane-based, high-efficiency, microfluidic debubbler.

    PubMed

    Liu, Changchun; Thompson, Jason A; Bau, Haim H

    2011-05-07

    In many lab-on-chip applications, it is necessary to remove bubbles from the flow stream. Existing bubble removal strategies have various drawbacks such as low degassing efficiency, long degassing time, large dead volumes, sensitivity to surfactants, and the need for an external vacuum or pressure source. We report on a novel, simple, robust, passive, nozzle-type, membrane-based debubbler that can be readily incorporated into microfluidic devices for rapid degassing. The debubbler is particularly suitable to operate with microfluidic systems made with plastic. The debubbler consists of a hydrophobic, porous membrane that resembles a normally closed valve, which is forced open by the working fluid's pressure. To illustrate the operation of the debubbler, we describe its use in the context of a chip containing a bead array for immunoassays. Our debubbler was able to completely filter gas bubbles out of a segmented flow at rates up to 60 µl s(-1) mm(-2) of membrane area. © The Royal Society of Chemistry 2011

  3. Ammonium in aqueous fluids to 600 °C, 1.3 GPa: A spectroscopic study on the effects on fluid properties, silica solubility, and K-feldspar to muscovite reactions

    NASA Astrophysics Data System (ADS)

    Schmidt, Christian; Watenphul, Anke

    2010-12-01

    The behavior of ammonium, NH 4+, in aqueous systems was studied based on Raman spectroscopic experiments to 600 °C and about 1.3 GPa. Spectra obtained at ambient conditions revealed a strong reduction of the dynamic three-dimensional network of water with addition of ammonium chloride, particularly at small solute concentrations. The differential scattering cross section of the ν 1-NH 4+ Raman band in these solutions was found to be similar to that of salammoniac. The Raman band of silica monomers at ˜780 cm -1 was present in all spectra of the fluid at high temperatures in hydrothermal diamond-anvil cell experiments with H 2O ± NH 4Cl and quartz or the assemblage quartz + kyanite + K-feldspar ± muscovite/tobelite. However, these spectra indicated that dissolved silica is less polymerized in ammonium chloride solutions than in comparable experiments with water. Quantification based on the normalized integrated intensity of the H 4SiO 40 band showed that the silica solubility in experiments with H 2O + NH 4Cl was significantly lower than that in equimolal NaCl solutions. This suggests that ammonium causes a stronger decrease in the activity of water in chloridic solutions than sodium. The Raman spectra of the fluid also showed that a significant fraction of ammonium was converted to ammonia, NH 3, in all experiments at temperatures above 300 °C. This indicates a shift towards acidic conditions for experiments without a buffering mineral assemblage. The estimated pH of the fluid was ˜2 at 600 °C, 0.26 GPa, 6.6 m initial NH 4Cl, based on the ratio of the integrated ν 1-NH 3 and ν 1-NH 4+ intensities and the HCl 0 dissociation constant. The NH 3/NH 4+ ratio increased with temperature and decreased with pressure. This implies that more ammonium should be retained in K-bearing minerals coexisting with chloridic fluids upon high- P low- T metamorphism. At 500 °C, 0.73 GPa, ammonium partitions preferentially into the fluid, as constrained from infrared

  4. Soluble complement receptor type 1 in serum and cerebrospinal fluid of patients with Guillain-Barré syndrome and multiple sclerosis.

    PubMed

    Vedeler, C A; Matre, R; Sadallah, S; Schifferli, J

    1996-06-01

    Activation of complement is critically involved in inflammatory reactions in both Guillain-Barré syndrome (GBS) and multiple sclerosis (MS). Soluble human complement receptor 1 (sCR1) blocks complement activation by both classical and alternative pathways. We studied serum and cerebrospinal fluid (CSF) concentrations of sCR1 in 23 patients with GBS, 27 patients with MS and 30 controls. No significant differences were found between patients and controls. Transient liver affection probably caused high serum sCR1 levels in two patients with GBS. The serum and CSF sCR1 levels were not correlated to the disease activity of GBS and MS, nor to the relapsing-remitting or chronic-progressive forms of MS. In GBS the CSF sCR1 levels correlated with the CSF total protein concentrations (r = 0.9, P < 0.01), suggesting that sCR1 leaks from serum into CSF via a damaged blood-nerve barrier. The serum sCR1 levels in GBS were slightly higher than in MS (P < 0.05). Whether this reflects changes in the release or consumption of sCR1 in these patients is at present unknown.

  5. Supercritical fluid chromatographic resolution of water soluble isomeric carboxyl/amine terminated peptides facilitated via mobile phase water and ion pair formation.

    PubMed

    Patel, M A; Riley, F; Ashraf-Khorassani, M; Taylor, L T

    2012-04-13

    Both analytical scale and preparative scale packed column supercritical fluid chromatography (SFC) have found widespread applicability for chiral separations of multiple polar pharmaceutical candidates. However, SFC is rapidly becoming an achiral technique. More specifically, ion pair SFC is finding greater utility for separation of ionic analytes such as amine salts and organic sulfonates. The key to this success is, in part, the incorporation of additives such as trifluoroacetic acid and ammonium acetate into the mobile phase in association with a wide variety of both bonded silica stationary phases and high purity bare silica. Ion pairing SFC coupled with evaporative light scattering detection and mass spectrometric detection is presented here for the separation of water soluble, uncapped, isomeric peptide pairs that differ in amino acid arrangement. The separation is best achieved on either diol-bonded silica or bare silica with 1-5% (w/w) water as a significant ingredient in the mobile phase. Nitrogenous stationary phases such as 2-ethylpyridine, which had been very successful for the separation of capped peptides failed to yield the desired separation regardless of the mobile phase composition. A HILIC type retention mechanism is postulated for the separation of both isomeric uncapped peptide pairs.

  6. The transition from dilute electrolyte aqueous solution to molten salt in geologic fluids: evidence from calcite solubility measurement in Na-halide solutions at 8 kbar and 700 °C

    NASA Astrophysics Data System (ADS)

    Galvez, M.; Manning, C. E.

    2014-12-01

    Fluids are major agents of mass and heat transport in the Earth crust and in subduction zones. Fluid inclusions, metasomatic field relations and experimental evidence suggest that these fluids can contain important ligands, including halogens, sulfates, sulfides, etc. The ligands participate in the complexation of rock-forming elements during mineral dissolution to high-T and P. Although models of high- element metasomatism typically assume that H2O dominates the fluid's solvent properties, however, H2O may be a relatively minor component in the high-PT brines that are increasingly recognized in the lower crust and mantle. Understanding the evolution of solubility mechanisms as fluids change from dilute aqueous solutions to salt-rich brines is hindered by the absence of experimental investigation of this transition. To address this problem, we conducted experiments on the solubility of calcite in sodium-halide solutions at 8 kbar and 700 °C using hydrothermal piston-cylinder weight-loss methods. Investigated salts were NaL , where L=F, Cl, Br, I, at concentrations ranging from 0.15 molal to 20 molal (XNaL ~ 0.3). At these conditions, the fluid is a single supercritical fluid phase . Run durations were 4 to 20 hours. Results demonstrate systematic trends with ligand ionic size, and locate a major mechanistic transition in the vicinity of XNaL~ 0.1 for all calcite-H2O-NaL systems. At lower than this critical composition (Xcrit), calcite solubility displays a pronounced concave shape indicating involvement of water during the dissolution process. At XNaL> Xcrit , the shape becomes convex with no apparent effect of decreased H2O activity in the fluid. The solubility patterns suggest that the solvent properties are dominated by those of H2O at XNaL< Xcrit, but at XNaL> Xcrit, H2O is a solute in a solution behaving as a molten salt. Geological evidence suggests that salt concentrations may reach values similar to or greater than Xcrit in a range of metamorphic and

  7. The calculated solubility of platinum and gold in oxygen-saturated fluids and the genesis of platinum-palladium and gold mineralization in the unconformity-related uranium deposits

    NASA Astrophysics Data System (ADS)

    Jaireth, S.

    1992-01-01

    Thermodynamic calculations on the solubility of platinum and gold indicate that saline (1 m NaCl), fluids saturated with atmospheric oxygen can transport geologically realistic concentrations of platinum-group-elements (PGE), gold, and uranium as chloro-complexes. A number of calculations involving fluid-rock interaction suggest that the oxygen-saturated fluids flowing through rocks containing quartz, muscovite, kaolinite, magnetite and hematite, initially oxidize any magnetite to hematite, allowing subsequent batches of ore fluids to retain their high oxidation state. During their migration through the aquifer, the oxidizing fluids would move the oxidation-reduction interface deeper into the aquifer, leaching and redepositing platinum and gold. The redissolution of earlier precipitated platinum and gold depends on the fluid/ rock ratio and the associated increase in the oxidation state. Therefore, lowering of fluid/rock ratios and/or mixing of the oxidized fluids with a large amount of reduced fluid will precipitate uranium, PGE, and gold. It is suggested that this model can explain the genesis of gold and PGE mineralization in the unconformity-related uranium deposits of the Alligator Rivers Uranium Field in the Northern Territory, Australia.

  8. Amniotic fluid soluble myeloid differentiation-2 (sMD-2) as regulator of intra-amniotic inflammation in infection-induced preterm birth

    PubMed Central

    Dulay, Antonette T.; Buhimschi, Catalin S.; Zhao, Guomao; Oliver, Emily; Abdel-Razeq, Sonya S.; Shook, Lydia L.; Bahtiyar, Mert O.; Buhimschi, Irina A.

    2015-01-01

    Problem TLR4 mediates host responses to pathogens through a mechanism that involves protein myeloid differentiation-2 (MD-2) and its soluble form sMD-2. The role of sMD2 in intra-amniotic inflammation induced preterm birth has not been previously explored. Method of study Human amniotic fluid (AF) sMD-2 was studied by Western blotting in 152 AF samples of patients who had an amniocentesis to rule-out infection (yes infection, n=50; no infection, n=50) or women with normal pregnancy outcome (2nd trimester genetic karyotyping, n=26; 3rd trimester lung maturity testing, n=26). Histologic localization and mRNA expression of MD2 in fetal membranes were studied by immunohistochemistry and RT-PCR. The ability of fetal membrane to release sMD-2 and inflammatory cytokines was studied in-vitro. Results Human AF contains three sMD-2 proteoforms whose levels of expression were lower at term. Intra-amniotic infection up-regulated sMD-2. MD-2 mRNA and immunohistochemistry findings concurred. In vitro, LPS and monensin increased while cycloheximide decreased sMD-2 production. Recombinant sMD-2 modulated TNF-α and IL-6 levels in a dose and time-dependent fashion. Conclusion sMD2 proteoforms are constitutively present in human AF. The intensity of the intra-amniotic inflammatory response to bacteria or perhaps to other TLR4 ligands may be facilitated through synthesis and release of sMD2 by the amniochorion. PMID:25605324

  9. A new sandwich immunoassay for detection of the α-secretase cleaved, soluble amyloid-β protein precursor in cerebrospinal fluid and serum.

    PubMed

    Taverna, Mara; Straub, Tobias; Hampel, Harald; Rujescu, Dan; Lichtenthaler, Stefan F

    2013-01-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder. Frequently used diagnostic biomarkers are amyloid-β42 (Aβ42), tau, and phospho-tau, which are measured in cerebrospinal fluid (CSF), and allow a reasonable, but not full, separation of AD patients and controls. Besides Aβ42, additional proteolytic cleavage products of the amyloid-β protein precursor (AβPP) have been investigated as potential biomarkers. This includes the α-secretase cleaved soluble AβPP ectodomain (sAβPPα). However, some studies found a reduction of sAβPPα, whereas other studies reported an increase of sAβPPα in the CSF of AD patients. The divergent findings may result from the detection of sAβPPα with antibodies, such as 6E10, which do not exclusively detect sAβPPα, but also the alternative β-secretase cleavage product sAβPPβ'. Here, we used the sAβPPα-specific antibody 14D6 and developed an ELISA-like sandwich immunoassay. The assay specifically detected sAβPPα in cell culture supernatants, in human CSF and even in serum, which is more readily accessible than CSF. The assay was used to analyze sAβPPα levels in CSF and serum of AD patients and controls. The assay detected a mild, but significant increase in sAβPPα in the CSF of AD patients compared to non-demented controls, while a mild reduction was observed in serum. The 14D6 assay in CSF allowed a better separation of AD patients from controls compared to the 6E10 antibody. Taken together, the new assay is widely applicable for specific sAβPPα measurement in culture media, CSF, and serum.

  10. Premelting polymerization of crustal and mantle fluids, as indicated by the solubility of albite + paragonite + quartz in H 2O at 1 GPa and 350-620 °C

    NASA Astrophysics Data System (ADS)

    Manning, Craig E.; Antignano, Angelo; Lin, Heather A.

    2010-04-01

    The composition and structure of dissolved silicates in model crustal and upper-mantle fluids was assessed by measuring the solubility of the assemblage albite + paragonite + quartz in H 2O from 350 to 620 °C, at 1 GPa. Natural, low albite and quartz were equilibrated with H 2O; paragonite grew in all experiments due to incongruent dissolution of albite + quartz. Melting occurred at 635 ± 5 °C. Solute concentrations at subsolidus conditions were determined by analysis of quenched fluids or mineral weight-loss and mass balance. Bulk solubility of the mineral assemblage increased from ˜ 1 to ˜ 8 oxide wt.% with rising temperature. Si, Al, and Na all increase in concert. The solutions were slightly peralkaline, and possess Si/(Na + Al) ≫ 1.5 (molar) at all conditions studied. Extrapolated thermodynamic data were used to predict solubility at the conditions investigated experimentally. Calculated solubility agreed with that measured from 350 to ˜ 500 °C; however, above 500 °C, the calculations underpredict solubility to an increasing degree as the hydrothermal melting point is approached. The excess measured solubility points to increasing abundance of aqueous Si, Al-Si, and Na-Al-Si polymers. Polymerized solutes predominate in all near-solidus solutions, rising to > 80% of total dissolved solids at the melting point. The observations support a conceptual model in which, as the temperature of the system rises isobarically at 1 GPa, the silicate components dissolved in the aqueous phase begin to polymerize significantly within ˜ 100 °C of the melting point. The polymerized solutes may facilitate condensation of more polymerized hydrous silicate liquid at the hydrothermal melting point. From the perspective of isobaric cooling, the fluid crossing the solidus retains Na-Al-Si-O clusters or fragments that are less polymerized than those which comprised the melt, but more polymerized than has previously been inferred for the aqueous phase. The high

  11. Amniotic Fluid Angiopoietin-1, Angiopoietin-2, and Soluble Receptor Tunica Interna Endothelial Cell Kinase-2 Levels and Regulation in Normal Pregnancy and Intraamniotic Inflammation-Induced Preterm Birth

    PubMed Central

    Buhimschi, Catalin S.; Bhandari, Vineet; Dulay, Antonette T.; Thung, Stephen; Razeq, Sonya S. Abdel-; Rosenberg, Victor; Han, Christina S.; Ali, Unzila A.; Zambrano, Eduardo; Zhao, Guomao; Funai, Edmund F.; Buhimschi, Irina A.

    2010-01-01

    Background: Angiopoietin-1 (Ang-1) and Ang-2 act selectively on endothelial cells by engaging the Tunica interna endothelial cell kinase-2 (Tie2) receptor. A soluble form of Tie2 (sTie2) blocks angiopoietin bioactivity. Objective: The aim of the study was to characterize changes and expression patterns of Ang-1, Ang-2, and sTie2 in amniotic fluid (AF) and placenta during human pregnancy and intraamniotic inflammation (IAI)-induced preterm birth. Design and Setting: We conducted a cross-sectional study at a tertiary university hospital. Patients: AF levels of Ang-1, Ang-2, and sTie2 were evaluated in 176 women during second trimester (n = 40), third trimester (n = 37), and preterm labor (positive IAI, n = 50; negative IAI, n = 49). Placenta and cord blood of select women were analyzed. Main Outcome Measures: Ang-1, Ang-2, sTie2, and IL-6 were evaluated by ELISA. Real-time PCR measured Ang-1, Ang-2, and Tie2 placental mRNA levels. Placenta was immunostained for Ang-1 and Ang-2. Placental explant cultures were stimulated with lipopolysaccharide, Pam3Cys, and modulators of protein synthesis/secretion (cycloheximide, monensin, and brefeldin A). Results: In normal pregnancy, the levels and ratios of AF Ang-1, Ang-2, and sTie2 varied with gestational age (GA) (P < 0.001). PCR revealed corresponding changes in placental Ang-1 and Ang-2, but not Tie2, mRNA. IAI raised AF Ang-1, Ang-2, and sTie2 above the expected level for GA without affecting their placental mRNA. Ang-2 immunoreactivity appeared enhanced in areas of villous edema. AF Ang-2/Ang-1 ratio was an important determinant of cord blood IL-6 (P < 0.001). Ex-vivo, sTie2 release was increased by Golgi disrupting but not bacterial mimic agents. Conclusions: Ang-1, Ang-2, and sTie2 are physiological constituents of AF that are GA and IAI regulated. Ang-2/Ang-1 ratio may play a role in modulating the fetal inflammatory response to IAI. Placental sTie2 shedding likely involves a Golgi-mediated mechanism. PMID:20410222

  12. Soluble CD14 in cerebrospinal fluid is associated with markers of inflammation and axonal damage in untreated HIV-infected patients: a retrospective cross-sectional study.

    PubMed

    Jespersen, Sofie; Pedersen, Karin Kæreby; Anesten, Birgitta; Zetterberg, Henrik; Fuchs, Dietmar; Gisslén, Magnus; Hagberg, Lars; Trøseid, Marius; Nielsen, Susanne Dam

    2016-04-21

    HIV-associated cognitive impairment has declined since the introduction of combination antiretroviral treatment (cART). However, milder forms of cognitive impairment persist. Inflammation in the cerebrospinal fluid (CSF) has been associated with cognitive impairment, and CSF neurofilament light chain protein (NFL) and CSF neopterin concentrations are increased in those patients. Microbial translocation in HIV infection has been suggested to contribute to chronic inflammation, and lipopolysaccharide (LPS) and soluble CD14 (sCD14) are markers of microbial translocation and the resulting monocyte activation, respectively. We hypothesised that microbial translocation contributes to inflammation and axonal damage in the central nervous system (CNS) in untreated HIV infection. We analyzed paired samples of plasma and CSF from 62 HIV-infected, untreated patients without cognitive symptoms from Sahlgrenska University Hospital, Gothenburg, Sweden. Measurements of neopterin and NFL in CSF were available from previous studies. Plasma and CSF sCD14 was measured using ELISA (R&D, Minneapolis, MN), and plasma and CSF LPS was measured using LAL colorimetric assay (Lonza, Walkersville, MD, USA). Univariate and multivariate regression analyses were performed. LPS in plasma was associated with plasma sCD14 (r = 0.31, P = 0.015), and plasma sCD14 was associated with CSF sCD14 (r = 0.32, P = 0.012). Furthermore, CSF sCD14 was associated with NFL (r = 0.32, P = 0.031) and neopterin (r = 0.32, P = 0.012) in CSF. LPS was not detectable in CSF. In a multivariate regression model CSF sCD14 remained associated with NFL and neopterin after adjusting for age, CD4+ cell count, and HIV RNA in CSF. In a group of untreated, HIV-infected patients LPS was associated with sCD14 in plasma, and plasma sCD14 was associated CSF sCD14. CSF sCD14 were associated with markers of CNS inflammation and axonal damage. This suggest that microbial translocation might be a driver

  13. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

  14. MStern Blotting–High Throughput Polyvinylidene Fluoride (PVDF) Membrane-Based Proteomic Sample Preparation for 96-Well Plates*

    PubMed Central

    Berger, Sebastian T.; Ahmed, Saima; Muntel, Jan; Cuevas Polo, Nerea; Bachur, Richard; Kentsis, Alex; Steen, Judith; Steen, Hanno

    2015-01-01

    We describe a 96-well plate compatible membrane-based proteomic sample processing method, which enables the complete processing of 96 samples (or multiples thereof) within a single workday. This method uses a large-pore hydrophobic PVDF membrane that efficiently adsorbs proteins, resulting in fast liquid transfer through the membrane and significantly reduced sample processing times. Low liquid transfer speeds have prevented the useful 96-well plate implementation of FASP as a widely used membrane-based proteomic sample processing method. We validated our approach on whole-cell lysate and urine and cerebrospinal fluid as clinically relevant body fluids. Without compromising peptide and protein identification, our method uses a vacuum manifold and circumvents the need for digest desalting, making our processing method compatible with standard liquid handling robots. In summary, our new method maintains the strengths of FASP and simultaneously overcomes one of the major limitations of FASP without compromising protein identification and quantification. PMID:26223766

  15. A thermodynamic model for calculating methane solubility, density and gas phase composition of methane-bearing aqueous fluids from 273 to 523 K and from 1 to 2000 bar

    NASA Astrophysics Data System (ADS)

    Duan, Zhenhao; Mao, Shide

    2006-07-01

    A thermodynamic model is presented to calculate methane solubility, liquid phase density and gas phase composition of the H 2O-CH 4 and H 2O-CH 4-NaCl systems from 273 to 523 K (possibly up to 573 K), from 1 to 2000 bar and from 0 to 6 mol kg -1 of NaCl with experimental accuracy. By a more strict theoretical approach and using updated experimental data, this model made substantial improvements over previous models: (1) the accuracy of methane solubility in pure water in the temperature range between 273 and 283 K is increased from about 10% to about 5%, but confirms the accuracy of the Duan model [Duan Z., Moller N., Weare J.H., 1992a. Prediction of methane solubilities in natural waters to high ionic strength from 0 to 250 °C and from 0 to 1600 bar. Geochim. Cosmochim. Acta56, 1451-1460] above 283 K up to 2000 bar; (2) the accuracy of methane solubility in the NaCl aqueous solutions is increased from >12% to about 6% on average from 273 K and 1 bar to 523 K and 2000 bar; (3) this model is able to calculate water content in the gas phase and liquid phase density, which cannot be calculated by previous models; and (4) it covers a wider range of temperature and pressure space. With a simple approach, this model is extended to predict CH 4 solubility in other aqueous salt solutions containing Na +, K +, Mg 2+, Ca 2+, Cl - and SO42-, such as seawater and geothermal brines, with excellent accuracy. This model is also able to calculate homogenization pressure of fluid inclusions (CH 4-H 2O-NaCl) and CH 4 solubility in water at gas-liquid-hydrate phase equilibrium. A computer code is developed for this model and can be downloaded from the website: www.geochem-model.org/programs.htm.

  16. Membrane-Based Characterization of a Gas Component — A Transient Sensor Theory

    PubMed Central

    Lazik, Detlef

    2014-01-01

    Based on a multi-gas solution-diffusion problem for a dense symmetrical membrane this paper presents a transient theory of a planar, membrane-based sensor cell for measuring gas from both initial conditions: dynamic and thermodynamic equilibrium. Using this theory, the ranges for which previously developed, simpler approaches are valid will be discussed; these approaches are of vital interest for membrane-based gas sensor applications. Finally, a new theoretical approach is introduced to identify varying gas components by arranging sensor cell pairs resulting in a concentration independent gas-specific critical time. Literature data for the N2, O2, Ar, CH4, CO2, H2 and C4H10 diffusion coefficients and solubilities for a polydimethylsiloxane membrane were used to simulate gas specific sensor responses. The results demonstrate the influence of (i) the operational mode; (ii) sensor geometry and (iii) gas matrices (air, Ar) on that critical time. Based on the developed theory the case-specific suitable membrane materials can be determined and both operation and design options for these sensors can be optimized for individual applications. The results of mixing experiments for different gases (O2, CO2) in a gas matrix of air confirmed the theoretical predictions. PMID:24608004

  17. Experimental Studies on Rutile Solubility

    NASA Astrophysics Data System (ADS)

    Rapp, J. F.; Klemme, S.; Butler, I. B.; Harley, S. L.

    2007-12-01

    Rutile (TiO2) is an important high field strength element (HFSE) sequestering mineral, and has been implicated in the observed depletion of HFSE in arc magmas. It is thought that rutile is insoluble in slab-derived fluids, and remains residual in the subducted slab. Indeed, experimental data indicates a very low solubility of rutile in pure H2O (Tropper and Manning, 2005), and this low solubility may result in HFSE depleted fluids imparting a depleted signature to arc magmas. However, there is scant experimental data available on rutile solubility in fluids of more complex compositions (Ayers and Watson, 1993). We are carrying out a systematic experimental study into the effect of specific chemical components on rutile solubility in fluids and also silicate melts. This should further our understanding of HFSE mobility in metamorphic rocks within subduction zones. References: J. C. Ayers and E. B. Watson (1993) Rutile solubility in supercritical aqueous fluids and the high P-T mobility of elements it concentrates. Contrib. Mineral. Petrol. 114, 321-330. P. Tropper and C. E. Manning (2005) Very low solubility of rutile in H2O at high pressure and temperature, and its implications for Ti mobility in subduction zones. American Mineralogist 90(2-3), 502-505.

  18. Solubility Database

    National Institute of Standards and Technology Data Gateway

    SRD 106 IUPAC-NIST Solubility Database (Web, free access)   These solubilities are compiled from 18 volumes (Click here for List) of the International Union for Pure and Applied Chemistry(IUPAC)-NIST Solubility Data Series. The database includes liquid-liquid, solid-liquid, and gas-liquid systems. Typical solvents and solutes include water, seawater, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. There are over 67,500 solubility measurements and over 1800 references.

  19. The solubility of platinum and gold in NaCl brines at 1.5 kbar, 600 to 800°C: A laser ablation ICP-MS pilot study of synthetic fluid inclusions

    NASA Astrophysics Data System (ADS)

    Hanley, Jacob J.; Pettke, Thomas; Mungall, James E.; Spooner, Edward T. C.

    2005-05-01

    The concentration and distribution of Pt and Au in a fluid-melt system has been investigated by reacting the metals with S-free, single-phase aqueous brines (20, 50, 70 wt% eq. NaCl) ± peraluminous melt at a confining pressure of 1.5 kbar and temperatures of 600 to 800 °C, trapping the fluid in synthetic fluid inclusions (quartz-hosted) and vesicles (silicate melt-hosted), and quantifying the metal content of the trapped fluid and glass by laser ablation ICP-MS. HCl concentration was buffered using the assemblage albite-andalusite-quartz and f was buffered using the assemblage Ni-NiO. Over the range of experimental conditions, measured concentrations of Pt and Au in the brines ( CPtfluid, CAufluid) are on on the order of 1-10 3 ppm. Concentrations of Pt and Au in the melt ( CPtmelt, CAumelt) are ˜35-100 ppb and ˜400-1200 ppb, respectively. Nernst partition coefficients ( DPtfluid/melt, DAufluid/melt) are on the order of 10 2-10 3 and vary as a function of Cmetalfluid (non-Henry's Law behavior). Trapped fluids show a significant range of metal concentrations within populations of inclusions from single experiments (˜ 1 log unit variability for Au; ˜2-3 log unit variability for Pt). Variability in metal concentration within single inclusion groups is attributed to premature brine entrapment (prior to metal-fluid-melt equilibrium being reached); this allows us to make only minimum estimates of metal solubility using metal concentrations from primary inclusions. The data show two trends: (i) maximum and average values of CAufluid and CPtfluid in inclusions decrease ˜2 orders of magnitude as fluid salinity ( m∑Clfluid) increases from ˜4 to 40 molal (20 to 70 wt % eq. NaCl) at a constant temperature; (ii) maximum and average values of CAufluid increase approximately 1 order of magnitude for every 100°C increase temperature at a fixed m∑Clfluid. The observed behavior may be described by the general expression: log⁡(mmetalfluid,T,1.5kbar

  20. C-telopeptide pyridinoline crosslinks of type I collagen, soluble RANKL, and osteoprotegerin levels in crevicular fluid of dental implants with peri-implantitis: a case-control study.

    PubMed

    Arikan, Fatih; Buduneli, Nurcan; Lappin, David F

    2011-01-01

    To evaluate levels of C-telopeptide pyridinoline crosslinks of type I collagen (ICTP), soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), and osteoprotegerin (OPG) in the crevicular fluid of endosseous dental implants with the clinical diagnosis of peri-implantitis and to compare these with the crevicular fluid of clinically healthy implants. Peri-implant crevicular fluid samples were obtained from 18 root-type implants with peri-implantitis in 12 patients and 21 clinically healthy implants in 16 other patients. Modified Plaque Index, probing depths, Gingival Index, and bleeding on probing were recorded at the crevicular fluid sampling sites. ICTP, sRANKL, OPG, and albumin levels in the peri-implant crevicular fluid samples were investigated by enzyme-linked immunosorbent assay. The clinical and biochemical data were evaluated statistically using Mann-Whitney U test. Spearman correlations were used to determine relationships between the biochemical data and the clinical parameters. Duration of implant loading, peri-implant crevicular fluid volume, and all clinical periodontal measurements were significantly greater in the peri-implantitis group than in the clinically healthy group. Total amounts of ICTP were significantly higher in the peri-implantitis group than in the healthy group. sRANKL concentrations, OPG total amounts, and OPG concentrations were significantly higher in the healthy group. The present findings suggest that local levels of ICTP and OPG reflect an increased risk of alveolar bone loss around dental implants, and their local levels may help to distinguish diseased and healthy sites.

  1. Serum and peritoneal fluid concentrations of soluble human leukocyte antigen, tumor necrosis factor alpha and interleukin 10 in patients with selected ovarian pathologies.

    PubMed

    Sipak-Szmigiel, Olimpia; Włodarski, Piotr; Ronin-Walknowska, Elżbieta; Niedzielski, Andrzej; Karakiewicz, Beata; Słuczanowska-Głąbowska, Sylwia; Laszczyńska, Maria; Malinowski, Witold

    2017-04-04

    Although immune system plays a key role in the pathogenesis of both endometriosis and ovarian cancer, its function is different. Therefore, we hypothesized, that selected immune parameters can serve as diagnostic markers of these two conditions. The aim of this study was to compare serum and peritoneal fluid concentrations of sHLA-G, IL-10 and TNF-alpha in women with selected ovarian pathologies: benign serous cysts, endometrioma and malignant tumors. Clinical significance of using them for diagnostic purposes in women with serous ovarian cysts, endometriosis, and ovarian cancer, which in the future may improve the early diagnosis of ovarian diseases. The study included women treated surgically for benign serous ovarian cysts, ovarian endometrioma and serous ovarian adenocarcinomas. Peripheral blood and peritoneal fluid samples were obtained intraoperatively. Patients with benign serous cysts, endometrioma and ovarian malignancies did not differ significantly in terms of their serum and peritoneal fluid concentrations of sHLA-G. Ovarian cancer patients presented with significantly higher median serum concentrations of IL-10 and TNF-alpha than other study subjects. Median concentrations of IL-10 and TNF-alpha in peritoneal fluid turned out to be the highest in ovarian cancer patients, followed by women with endometrioma and subjects with benign serous cysts. All these intergroup differences were statistically significant. Irrespective of the group, median concentrations of sHLA-G, IL-10 and TNF-alpha in peritoneal fluid were higher than serum levels of these markers. Elevated serum and peritoneal fluid concentrations of IL-10 and TNF-alpha distinguish ovarian malignancies and endometriomas from benign serous ovarian cysts. In contrast to endometriosis, ovarian malignancies are characterized by elevated peritoneal fluid concentrations of IL-10 and TNF-alpha, elevated serum concentrations of IL-10 and low serum levels of TNF-alpha. Serum and peritoneal fluid

  2. Cell or Cell Membrane-Based Drug Delivery Systems

    PubMed Central

    Tan, Songwei; Wu, Tingting; Zhang, Dan; Zhang, Zhiping

    2015-01-01

    Natural cells have been explored as drug carriers for a long period. They have received growing interest as a promising drug delivery system (DDS) until recently along with the development of biology and medical science. The synthetic materials, either organic or inorganic, are found to be with more or less immunogenicity and/or toxicity. The cells and extracellular vesicles (EVs), are endogenous and thought to be much safer and friendlier. Furthermore, in view of their host attributes, they may achieve different biological effects and/or targeting specificity, which can meet the needs of personalized medicine as the next generation of DDS. In this review, we summarized the recent progress in cell or cell membrane-based DDS and their fabrication processes, unique properties and applications, including the whole cells, EVs and cell membrane coated nanoparticles. We expect the continuing development of this cell or cell membrane-based DDS will promote their clinic applications. PMID:26000058

  3. Membrane-based microextraction techniques in analytical chemistry: A review.

    PubMed

    Carasek, Eduardo; Merib, Josias

    2015-06-23

    The use of membrane-based sample preparation techniques in analytical chemistry has gained growing attention from the scientific community since the development of miniaturized sample preparation procedures in the 1990s. The use of membranes makes the microextraction procedures more stable, allowing the determination of analytes in complex and "dirty" samples. This review describes some characteristics of classical membrane-based microextraction techniques (membrane-protected solid-phase microextraction, hollow-fiber liquid-phase microextraction and hollow-fiber renewal liquid membrane) as well as some alternative configurations (thin film and electromembrane extraction) used successfully for the determination of different analytes in a large variety of matrices, some critical points regarding each technique are highlighted.

  4. Experimental investigation of talc solubility in H sub 2 O-MgCl sub 2 -NaCl-HCl fluids in the range 500-700C, 2 kb

    SciTech Connect

    Grabman, K.B.; Popp, R.K. )

    1991-10-01

    The equilibrium solubility of the talc-quartz mineral assemblage in H{sub 2}O-MgCl{sub 2}-NaCl-HCl fluids at 2 kb and temperatures in the range 500-700C has been determined using rapid-quench hydrothermal techniques. At 500C, the concentration of Mg measured in the fluid after quench decreased in a systematic, nonlinear fashion with increasing concentrations of NaCl, from 2.8 m Mg in NaCl-free solutions to 1.5 m in 5.1 m NaCl. In contrast, at 600 and 700C Mg molalities increased with increasing NaCl molalities. At 600C, the concentration of Mg increased from 0.072 to 0.12 m as the concentration of NaCl increased from 0.0 to 6.1 m. At 700C, Mg molality increased from an NaCl-free value of 0.0078 m, to 0.031 m in 6.3 m NaCl. The observed solubilities were compared to concentrations of aqueous species calculated by solving the series of mass-action and mass-balance equations that describe the activities and molalities of the relevant species in the fluid. It is concluded that at 500C, MgCl{sub 2}{sup 0}, MgCl+, and Mg{sup 2+} are the only Mg-species necessary to account for the observed behavior. The calculations suggest that the decrease in Mg results from both the increasing concentrations of Cl{sup {minus}} as NaCl concentration increases, and the changing dielectric properties of the fluid. At 600 and 700C, the presence of Mg-species in addition to MgCl{sub 2}{sup 0}, MgCl{sup +}, and Mg{sup 2+} may be required to describe the increased solubility observed in the experiments. Use of the slope-quantification method for identifying aqueous species indicates that higher order Mg-Cl species or Na-Mg-Cl species are possible, but the precision of the technique is not sufficient to uniquely identify the species.

  5. Investigations on the solubility of corrosion products on depleted uranium projectiles by simulated body fluids and the consequences on dose assessment.

    PubMed

    Gerstmann, Udo C; Szymczak, Wilfried; Höllriegl, Vera; Li, Wei Bo; Roth, Paul; Schramel, Peter; Takenaka, Shinji; Oeh, Uwe

    2008-04-01

    Ingestion and inhalation of corrosion products covering weathered penetrators made of depleted uranium (DU) represent potential radiological exposure pathways. In order to study the bioavailability of these corrosion products, their solubility was determined using simulated gastric and pulmonary juices. About 75 and 36% of the uranium in the corrosion products were found to be soluble in simulated gastric and pulmonary juices, respectively. The effective dose coefficient for adults after ingestion was calculated to be 0.61 muSv mg(-1) DU. This compares to an effective dose coefficient for an adult of 0.71 muSv mg(-1) for DU materials given by the World Health Organization (WHO). The effective dose coefficient for inhalation was calculated to be 3.7 x 10(-6 )Sv Bq(-1) for workers and 5.3 x 10(-6 )Sv Bq(-1) for members of the public, respectively, which is between those of particles of Types M and S as defined by the International Commission on Radiological Protection (ICRP). The speciation of the corrosion products was investigated by time-of-flight secondary ion mass spectrometry (TOF-SIMS). The mean oxidation state of uranium was found to be 4.6, which suggests that the uranium in the corrosion products consists of a mixture of U(IV) and U(VI) species.

  6. Membrane-based processes for sustainable power generation using water.

    PubMed

    Logan, Bruce E; Elimelech, Menachem

    2012-08-16

    Water has always been crucial to combustion and hydroelectric processes, but it could become the source of power in membrane-based systems that capture energy from natural and waste waters. Two processes are emerging as sustainable methods for capturing energy from sea water: pressure-retarded osmosis and reverse electrodialysis. These processes can also capture energy from waste heat by generating artificial salinity gradients using synthetic solutions, such as thermolytic salts. A further source of energy comes from organic matter in waste waters, which can be harnessed using microbial fuel-cell technology, allowing both wastewater treatment and power production.

  7. Gallium nitride electrodes for membrane-based electrochemical biosensors

    NASA Astrophysics Data System (ADS)

    Schubert, T.; Steinhoff, G.; von Ribbeck, H.-G.; Stutzmannn, M.; Eickhoff, M.; Tanaka, M.

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50mHz and 50kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  8. Gallium nitride electrodes for membrane-based electrochemical biosensors.

    PubMed

    Schubert, T; Steinhoff, G; von Ribbeck, H-G; Stutzmannn, M; Eickhoff, M; Tanaka, M

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50 mHz and 50 kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  9. Preparation of olanzapine and methyl-β-cyclodextrin complexes using a single-step, organic solvent-free supercritical fluid process: An approach to enhance the solubility and dissolution properties.

    PubMed

    Rudrangi, Shashi Ravi Suman; Trivedi, Vivek; Mitchell, John C; Wicks, Stephen Richard; Alexander, Bruce David

    2015-10-15

    The purpose of this study was to evaluate a single-step, organic solvent-free supercritical fluid process for the preparation of olanzapine-methyl-β-cyclodextrin complexes with an express goal to enhance the dissolution properties of olanzapine. The complexes were prepared by supercritical carbon dioxide processing, co-evaporation, freeze drying and physical mixing. The prepared complexes were then analysed by differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, solubility and dissolution studies. Computational molecular docking studies were performed to study the formation of molecular inclusion complexation of olanzapine with methyl-β-cyclodextrin. All the binary mixtures of olanzapine with methyl-β-cyclodextrin, except physical mixture, exhibited a faster and greater extent of drug dissolution than the drug alone. Products obtained by the supercritical carbon dioxide processing method exhibited the highest apparent drug dissolution. The characterisation by different analytical techniques suggests complete complexation or amorphisation of olanzapine and methyl-β-cyclodextrin complexes prepared by supercritical carbon dioxide processing method. Therefore, organic solvent-free supercritical carbon dioxide processing method proved to be novel and efficient for the preparation of solid inclusion complexes of olanzapine with methyl-β-cyclodextrin. The preliminary data also suggests that the complexes of olanzapine with methyl-β-cyclodextrin will lead to better therapeutic efficacy due to better solubility and dissolution properties.

  10. A Novel HPLC Method for the Concurrent Analysis and Quantitation of Seven Water-Soluble Vitamins in Biological Fluids (Plasma and Urine): A Validation Study and Application

    PubMed Central

    Grotzkyj Giorgi, Margherita; Howland, Kevin; Martin, Colin; Bonner, Adrian B.

    2012-01-01

    An HPLC method was developed and validated for the concurrent detection and quantitation of seven water-soluble vitamins (C, B1, B2, B5, B6, B9, B12) in biological matrices (plasma and urine). Separation was achieved at 30°C on a reversed-phase C18-A column using combined isocratic and linear gradient elution with a mobile phase consisting of 0.01% TFA aqueous and 100% methanol. Total run time was 35 minutes. Detection was performed with diode array set at 280 nm. Each vitamin was quantitatively determined at its maximum wavelength. Spectral comparison was used for peak identification in real samples (24 plasma and urine samples from abstinent alcohol-dependent males). Interday and intraday precision were <4% and <7%, respectively, for all vitamins. Recovery percentages ranged from 93% to 100%. PMID:22536136

  11. A comparison of gastric emptying of soluble solid meals and clear fluids matched for volume and energy content: a pilot crossover study.

    PubMed

    Okabe, T; Terashima, H; Sakamoto, A

    2017-08-14

    We previously demonstrated that the gastric emptying time of different liquids with the same volume mainly depended on their energy content, regardless of differences in composition. In this crossover study, we investigated whether the same applies when soluble solid foods are ingested with water. Ten healthy volunteers ingested one of five test diets consisting of two test meals (Calorie Mate(®) 100 and 200 kcal) and three test solutions (water and glucose solutions of 100 and 200 kcal), each given in a volume of 400 ml, and then underwent ultrasonography to measure the gastric antral cross-sectional area every 10 min for 120 min. The gastric emptying time was defined as the time for the antral cross-sectional area to revert to its initial value. When test diets with the same energy content were ingested, the gastric emptying curves were nearly identical, regardless of whether the original form was solid or liquid. The median (IQR[range]) gastric emptying times of Calorie Mate(®) of 100 kcal with water vs. isocaloric glucose solution were 65 (60-78 [50-80]) vs. 65 (60-70 [50-80]) min (p = 0.58), and for Calorie Mate(®) of 200 kcal with water vs. isocaloric glucose solution they were 100 (93-108 [90-120]) vs. 105 (90-110 [90-120]) min (p = 0.54). The median (IQR [range]) for water was 40 (30-40 [30-50]) min. Energy content may be a critical determinant of the gastric emptying time when ingesting soluble solid diets with water. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

  12. Rare earth element enrichment using membrane based solvent extraction

    NASA Astrophysics Data System (ADS)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Zunita, M.; Wenten, I. G.

    2017-01-01

    The chemical, catalytic, electrical, magnetic, and optical properties of rare earth elements are required in broad applications. Rare earth elements have similar physical and chemical properties thus it is difficult to separate one from each other. Rare earth element is relatively abundant in earth's crust but rarely occur in high concentrated deposits. Traditionally, ion-exchange and solvent extraction techniques have been developed to separate and purify single rare earth solutions or compounds. Recently, membrane starts to gain attention for rare earth separation by combining membrane and proven technologies such as solvent extraction. Membrane-based process offers selective, reliable, energy efficient and easy to scale up separation. During membrane-based separation process, one phase passes through membrane pores while the other phase is rejected. There is no direct mixing of two phases thus the solvent loss is very low. Membrane can also lower solvent physical properties requirement (viscosity, density) and backmixing, eliminate flooding phenomenon and provide large interfacial area for mass transfer. This paper will summarize research efforts in developing membrane technology for rare earth element separation. Special attention will be given to solvent extraction related process as the commonly used method for rare earth element separation. Furthermore, membrane configuration and its potentials will also be discussed.

  13. Membrane-Based Water Evaporator for a Space Suit

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; McCann, Charles J.; O'Connell, Mary K.; Andrea, Scott

    2004-01-01

    A membrane-based water evaporator has been developed that is intended to serve as a heat-rejection device for a space suit. This evaporator would replace the current sublimator that is sensitive to contamination of its feedwater. The design of the membrane-based evaporator takes advantage of recent advances in hydrophobic micropore membranes to provide robust heat rejection with much less sensitivity to contamination. The low contamination sensitivity allows use of the heat transport loop as feedwater, eliminating the need for the separate feedwater system used for the sublimator. A cross section of the evaporator is shown in the accompanying figure. The space-suit cooling loop water flows into a distribution plenum, through a narrow annulus lined on both sides with a hydrophobic membrane, into an exit plenum, and returns to the space suit. Two perforated metal tubes encase the membranes and provide structural strength. Evaporation at the membrane inner surface dissipates the waste heat from the space suit. The water vapor passes through the membrane, into a steam duct and is vented to the vacuum environment through a back-pressure valve. The back-pressure setting can be adjusted to regulate the heat-rejection rate and the water outlet temperature.

  14. Soluble surfactants favorably modify fluid structure and wall shear stress profiles during near-occluding bubble motion in a computational model of intravascular gas embolism

    NASA Astrophysics Data System (ADS)

    Swaminathan, T. N.; Ayyaswamy, P. S.; Eckmann, D. M.

    2009-11-01

    Finite sized gas bubble motion in a blood vessel causes temporal and spatial gradients of shear stress at the endothelial cell surface lining the vessel wall as the bubble approaches the cell, moves over it and passes it by. Rapid reversals occur in the sign of the shear stress imparted to the cell surface during this motion. The sign-reversing shear is a potently coupled source of cell surface mechanical stretch, potentiating cell injury. The presence of a suitable soluble surfactant in the bulk medium considerably reduces the level of the shear stress gradients imparted to the cell surface as compared to an equivalent surfactant-free system. The bubble shape and the film thickness between the bubble and the vessel wall are also different. Furthermore, the bubble residence time near the proximity of a cell surface changes in comparison. These results based on our modeling may help explain several phenomena observed in experimental studies related to gas embolism, a significant problem in cardiac surgery and decompression sickness.

  15. Multiplex Bead Array Assay for Detection of 25 Soluble Cytokines in Blister Fluid of Patients with Complex Regional Pain Syndrome Type 1

    PubMed Central

    Heijmans-Antonissen, Claudia; Wesseldijk, Feikje; Munnikes, Renate JM; Huygen, Frank JPM; van der Meijden, Patrick; Hop, Wim C. J.; Hooijkaas, Herbert; Zijlstra, Freek J.

    2006-01-01

    Inflammatory processes are known to be involved at least in the early phase of complex regional pain syndrome type 1 (CRPS1). Blister fluid obtained from the involved extremities displayed increased amounts of proinflammatory cytokines IL-6 and TNFα compared with the noninvolved extremities. The aim of this paper is to investigate the involvement of mediators by measurement of several other cytokines using new detection techniques that enable multiple cytokine measurement in small samples. The use of a multiplex-25 bead array cytokine assay and Luminex technology enabled simultaneous measurement of representative (1) proinflammatory cytokines such as GM-CSF, IL-1β, IL-1RA, IL-6, IL-8, and TNF-α; (2) Th1/Th2 distinguishing cytokines IFN-γ, IL-2, IL-2R, IL-4, IL-5, and IL-10; (3) nonspecific acting cytokines IFN-α, IL-7, IL-12p40/p70, IL-13, IL-15, and IL-17; and (4) chemokines eotaxin, IP-10, MCP-1, MIP-1α, MIP-1β, MIG, and RANTES. Although minimal detection levels are significantly higher in the bead array system than those in common ELISA assays, in blister fluid, IL-1RA, IL-6, IL-8, TNF-α, IL-12p40/p70, MCP-1, and MIP-1β were detectable and increased in CRPS1 affected extremities. Levels of IL-6 and TNF-α simultaneously measured by ELISA (Sanquin Compact kit) and by multiplex-25 bead array assay (Biosource) were highly correlated (r = 0.85, P < .001 for IL-6 and r = 0.88, P < .001 for TNF-α). Furthermore, IP-10 and eotaxin were detectable but diminished in CRPS1, whereas detectable amounts of IL-10 were similar in involved and noninvolved extremities. Multiplex bead array assays are useful systems to establish the involvement of cytokines in inflammatory processes by measurements in blister fluids of CRPS1. Ten representative cytokines were detectable. However, detection levels and amounts measured are at least 3 times higher in the multiplex-25 array assay than in the ELISA assays used simultaneously for the measurement of cytokines. PMID:16864900

  16. Development of polymer-membrane based electrodes for suramin.

    PubMed

    Yu, Andrew; Shepherd, Brandon; Wagner, Meghan; Clapper, Jamie; Esson, Joan M

    2011-02-07

    The development of a polymer membrane-based electrode to measure the anionic drug suramin in buffered saline and biological samples is described. A large non-equilibrium, steady state EMF response is observed toward suramin, and judicious choice of the polymer membrane components allows for adjustment of the dynamic range of the electrode. The optimized membrane for use in the toxic suramin range consists of 25 wt% tridodecylmethyl ammonium chloride, 55 wt% bis-2-ethylhexyl sebacate, and 20 wt% Pellethane. Although this electrode can be used to directly quantify suramin in human plasma, determination of suramin that is not affected by the background concentration of small anions is best achieved by simple potentiometric titrations with polycationic protamine monitored with a protamine-sensitive electrode.

  17. [Membrane-based photochemical systems as models for photosynthetic cells

    SciTech Connect

    Hurst, J.K.

    1992-01-01

    The objectives of this research are to improve our conceptual view of the ways in which membranes and interfaces can be used to control chemical reactivity. We have focused on understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis or related photoconversion/photostorage processes. Specifically, we have sought to identify: the influence of interfaces upon charge separation/recombination reactions, pathways for transmembrane charge separation across hydrocarbon bilayer membranes, and mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. As described in this report our recent research has led to considerable clarification of the underlying reaction mechanisms.

  18. Osmosensing by Bacteria: Signals and Membrane-Based Sensors

    PubMed Central

    Wood, Janet M.

    1999-01-01

    Bacteria can survive dramatic osmotic shifts. Osmoregulatory responses mitigate the passive adjustments in cell structure and the growth inhibition that may ensue. The levels of certain cytoplasmic solutes rise and fall in response to increases and decreases, respectively, in extracellular osmolality. Certain organic compounds are favored over ions as osmoregulatory solutes, although K+ fluxes are intrinsic to the osmoregulatory response for at least some organisms. Osmosensors must undergo transitions between “off” and “on” conformations in response to changes in extracellular water activity (direct osmosensing) or resulting changes in cell structure (indirect osmosensing). Those located in the cytoplasmic membranes and nucleoids of bacteria are positioned for indirect osmosensing. Cytoplasmic membrane-based osmosensors may detect changes in the periplasmic and/or cytoplasmic solvent by experiencing changes in preferential interactions with particular solvent constituents, cosolvent-induced hydration changes, and/or macromolecular crowding. Alternatively, the membrane may act as an antenna and osmosensors may detect changes in membrane structure. Cosolvents may modulate intrinsic biomembrane strain and/or topologically closed membrane systems may experience changes in mechanical strain in response to imposed osmotic shifts. The osmosensory mechanisms controlling membrane-based K+ transporters, transcriptional regulators, osmoprotectant transporters, and mechanosensitive channels intrinsic to the cytoplasmic membrane of Escherichia coli are under intensive investigation. The osmoprotectant transporter ProP and channel MscL act as osmosensors after purification and reconstitution in proteoliposomes. Evidence that sensor kinase KdpD receives multiple sensory inputs is consistent with the effects of K+ fluxes on nucleoid structure, cellular energetics, cytoplasmic ionic strength, and ion composition as well as on cytoplasmic osmolality. Thus, osmoregulatory

  19. Membrane-based systems for carbon capture and hydrogen purification

    SciTech Connect

    Berchtold, Kathryn A

    2010-11-24

    This presentation describes the activities being conducted at Los Alamos National Laboratory to develop carbon capture technologies for power systems. This work is aimed at continued development and demonstration of a membrane based pre- and post-combustion carbon capture technology and separation schemes. Our primary work entails the development and demonstration of an innovative membrane technology for pre-combustion capture of carbon dioxide that operates over a broad range of conditions relevant to the power industry while meeting the US DOE's Carbon Sequestration Program goals of 90% CO{sub 2} capture at less than a 10% increase in the cost of energy services. Separating and capturing carbon dioxide from mixed gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic temperatures and pressures as well as be compatible with large gas volumes. Our project team is developing polymer membranes based on polybenzimidazole (PBI) chemistries that can purify hydrogen and capture CO{sub 2} at industrially relevant temperatures. Our primary objectives are to develop and demonstrate polymer-based membrane chemistries, structures, deployment platforms, and sealing technologies that achieve the critical combination of high selectivity, high permeability, chemical stability, and mechanical stability all at elevated temperatures (> 150 C) and packaged in a scalable, economically viable, high area density system amenable to incorporation into an advanced Integrated Gasification Combined-Cycle (IGCC) plant for pre-combustion CO{sub 2} capture. Stability requirements are focused on tolerance to the primary synthesis gas components and impurities at various locations in the IGCC process. Since the process stream compositions and conditions (temperature and pressure) vary throughout the IGCC process, the project is focused on the

  20. Evolution of strategies to achieve baseline separation of ten anionic, water-soluble sulfated estrogens via achiral packed column supercritical fluid chromatography.

    PubMed

    Patel, M A; Hardink, M A; Wrisely, L; Riley, F W; Hudalla, C J; Ashraf-Khorassani, M; Taylor, L T

    2014-11-28

    Near baseline separation of ten sulfated sodium salts of various structurally related estrogens employing a variety of bonded stationary phase packed columns was obtained using a conventional supercritical fluid chromatograph coupled with UV detection. Critical pairs 2/3 (8,9-dehydroestrone/17β-dihydroequilin) and 6/7 (17α-estradiol or 17α-dihydroequilin/estrone), however, failed to baseline separate. In all preliminary separations, 10mM ammonium acetate and variable percentages of H2O were initially used as co-additives in conjunction with methanol as a modifier. Different modifier programs and temperatures were employed to optimize the separation in a timely manner. A 2-ethylpyridine column provided the best separation compared to bare silica, diol, and cyano-based bonded phase columns. The employment of both salt and water as additives to the methanol-modified CO2 mobile phase suggested a mixed mode separation mechanism involving both ion pairing of each anionic sulfated estrogen with ammonium ion and hydrophilic interaction facilitated by partitioning of analyte between the aqueous solvated stationary phase and the aqueous component of the mobile phase. Upon more extensive study with either iso-propylamine or formic acid-ammonium formate buffer, the critical anionic pairs were 95% baseline resolved.

  1. High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients

    PubMed Central

    Mizuno, Masashi; Suzuki, Yasuhiro; Higashide, Keiko; Sei, Yumi; Iguchi, Daiki; Sakata, Fumiko; Horie, Masanobu; Maruyama, Shoichi; Matsuo, Seiichi; Morgan, B. Paul; Ito, Yasuhiko

    2017-01-01

    Background We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis. Methods We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF. Results When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms. Conclusion Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis. PMID:28046064

  2. High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients.

    PubMed

    Mizuno, Masashi; Suzuki, Yasuhiro; Higashide, Keiko; Sei, Yumi; Iguchi, Daiki; Sakata, Fumiko; Horie, Masanobu; Maruyama, Shoichi; Matsuo, Seiichi; Morgan, B Paul; Ito, Yasuhiko

    2017-01-01

    We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis. We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF. When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms. Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis.

  3. Anhydrite Solubility and Ca Isotope Fractionation in the Vapor-Liquid Field of the NaCl-H2O System: Implications for Hydrothermal Vent Fluids at Mid-ocean Ridges

    NASA Astrophysics Data System (ADS)

    Scheuermann, P.; Syverson, D. D.; Higgins, J. A.; Seyfried, W. E., Jr.

    2015-12-01

    Hydrothermal experiments were performed at 410, 420 and 450°C between 180-450 bar to investigate anhydrite (CaSO4) solubility and Ca isotope fractionation in the liquid-vapor stability field of the NaCl-H2O system. Experiments were conducted in flexible gold reaction cells and a fixed volume Ti reactor to reach all pressures between the critical curve and three-phase boundary. During isothermal decompression at 410°C, anhydrite solubility in the liquid phase increases (1 to 9 mmol/kg Ca), whereas the solubility decreases in the vapor phase (130 to < 10 umol/kg Ca). At 410°C and 290-270 bar, the partition coefficient, log Km = log (mv / ml), for Ca decreases from -1.35 to -2.46, and that of SO4 decreases from -1.76 to -2.82. At 420°C the Ca:SO4 ratio of the starting solution was 2:1, and the pH25°C decreases in the liquid and increases in the vapor upon decompression. Ca hydrolysis in the liquid and complex interactions between undetermined aqueous species in the vapor could explain this pattern. At 410 and 450°C, the experiments started with a Ca:SO4 ratio of 1:1. Along the 410°C isotherm, pH25°C initially increases in both the liquid and vapor, potentially caused by precipitation of an H+ bearing salt, such as NaHSO4. 30-40 bar below the critical curve there is a sudden decrease in pH25°C as the putative salt phase may become unstable and dissolve. At 450°C, pH25°C decreases in the vapor and increases in the liquid, as HCl and H2SO4 partition into the vapor. Ca isotope data at 420°C between 375-300 bar indicate that the vapor is isotopically light relative to the liquid. At lower pressures both phases approach the isotopic composition of the coexisting anhydrite, suggesting that dissolved Ca speciation becomes more structurally similar to anhydrite. This study furthers our understanding of elemental partitioning and isotopic fractionation in mineral-fluid systems with implications for mass transfer reactions at/near the magma-hydrothermal boundary at

  4. Interaction of vitamin D with membrane-based signaling pathways

    PubMed Central

    Larriba, María Jesús; González-Sancho, José Manuel; Bonilla, Félix; Muñoz, Alberto

    2014-01-01

    Many studies in different biological systems have revealed that 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) modulates signaling pathways triggered at the plasma membrane by agents such as Wnt, transforming growth factor (TGF)-β, epidermal growth factor (EGF), and others. In addition, 1α,25(OH)2D3 may affect gene expression by paracrine mechanisms that involve the regulation of cytokine or growth factor secretion by neighboring cells. Moreover, post-transcriptional and post-translational effects of 1α,25(OH)2D3 add to or overlap with its classical modulation of gene transcription rate. Together, these findings show that vitamin D receptor (VDR) cannot be considered only as a nuclear-acting, ligand-modulated transcription factor that binds to and controls the transcription of target genes. Instead, available data support the view that much of the complex biological activity of 1α,25(OH)2D3 resides in its capacity to interact with membrane-based signaling pathways and to modulate the expression and secretion of paracrine factors. Therefore, we propose that future research in the vitamin D field should focus on the interplay between 1α,25(OH)2D3 and agents that act at the plasma membrane, and on the analysis of intercellular communication. Global analyses such as RNA-Seq, transcriptomic arrays, and genome-wide ChIP are expected to dissect the interactions at the gene and molecular levels. PMID:24600406

  5. Development of simulated intestinal fluids containing nutrients as transport media in the Caco-2 cell culture model: assessment of cell viability, monolayer integrity and transport of a poorly aqueous soluble drug and a substrate of efflux mechanisms.

    PubMed

    Lind, Marianne L; Jacobsen, Jette; Holm, René; Müllertz, Anette

    2007-12-01

    The purpose of this study was to identify simulated intestinal fluids (SIFs) containing nutrients compatible with the Caco-2 cell culture model and to examine the impact of the identified medium on the transport of a poorly aqueous soluble model compound, estradiol, and a substrate of efflux mechanisms, etoposide. Monolayer integrity was evaluated by transepithelial electrical resistance and cellular viability by release of lactate dehydrogenase to the apical compartment and cellular protein content. It was shown that the viability of Caco-2 cells was enhanced by use of the CO(2) independent nutritional medium, Leibovitz's L-15 compared to Hanks' balanced salt solution. SIF containing 5mM sodium taurocholate and 1.25 mM phosphatidylcholine or lysophosphatidylcholine in Leibovitz's L-15 induced less release of lactate dehydrogenase than the traditional transport medium, HBSS. Addition of lipolysis products, 0.5mM oleic acid and 0.25 mM monoolein, did only cause increase in lactate dehydrogenase in 3 of 12 comparisons. The presence of SIFs in the apical compartment was shown to decrease flux of estradiol due to incorporation of estradiol in micelles and hence a decreased fraction of free estradiol. Further, a concentration dependent increase in the apparent permeability of etoposide was observed from apical to basolateral compartment, which indicated that components in the SIFs affects efflux mechanisms.

  6. Human soluble receptor for advanced glycation end products and tumor necrosis factor-α as gingival crevicular fluid and serum markers of inflammation in chronic periodontitis and type 2 diabetes.

    PubMed

    Singhal, Sandeep; Pradeep, Avani R; Kanoriya, Dharmendra; Garg, Vibhuti

    2016-01-01

    The present study aimed to evaluate the levels of soluble receptor for advanced glycation end products (sRAGE) and tumor necrosis factor-α (TNF-α) in serum and gingival crevicular fluid (GCF) in chronic periodontitis (CP) patients with and without type 2 diabetes mellitus (T2DM). A total of 70 subjects were divided into four groups: group 1 (n = 15; subjects with healthy periodontium); group 2 (n = 20; CP patients); group 3 (n = 20; CP patients with T2DM); and group 4 (n = 15; CP patients without T2DM). The serum and GCF levels of human sRAGE and TNF-α were assessed using enzyme-linked immunosorbent assay and correlated with clinical parameters, including probing depth, gingival index and clinical attachment level. Both sRAGE and TNF-α levels varied with the inflammatory state of the patient; the highest levels of sRAGE were seen in group 1, whereas the lowest levels in group 3 (P < 0.05). Conversely, TNF-α levels were found to be the highest in group 3 and lowest in group 1 (P < 0.05). Thus, human sRAGE and TNF-α can be considered as possible GCF and serum markers of inflammatory activity in CP and T2DM.(J Oral Sci 58, 547-553, 2016).

  7. Experimental determination of quartz solubility and melting in the system SiO2-H2O-NaCl at 15-20 kbar and 900-1100 °C: implications for silica polymerization and the formation of supercritical fluids

    NASA Astrophysics Data System (ADS)

    Cruz, Miguel F.; Manning, Craig E.

    2015-10-01

    We investigated quartz solubility and melting in the system SiO2-NaCl-H2O at 15-20 kbar and 900-1100 °C using hydrothermal piston-cylinder methods. The solubility of natural, high-purity quartz was determined by weight loss. Quartz solubility decreases with increasing NaCl mole fraction ( X NaCl) at fixed pressure and temperature. The decline is greatest at low X NaCl. The solubility patterns can be explained by changes in the concentration and identity of silica oligomers. Modeling of results at 1000 °C, 15 kbar, reveals that silica monomers and dimers predominate at low Si concentration (high X NaCl), that higher oligomers assumed to be trimers become detectable at X NaCl = 0.23, and that the trimers contain >50 % of dissolved Si at X NaCl = 0. The modeling further implies a hydration number for the silica monomer of 1.6, significantly lower than is observed in previous studies. Results at 15 kbar and 1100 °C provide evidence of two coexisting fluid phases. Although solubility could not be determined directly in these cases, the presence or absence of phases over a range of bulk compositions permitted mapping of the topology of the phase diagram. At 1100 °C, 15 kbar, addition of only a small amount of NaCl ( X NaCl = 0.05) leads to separation of two fluid phases, one rich in H2O and SiO2, the other rich in NaCl with lower SiO2. Textural identification of two fluids is supported by very low quench pH due to preferential partitioning of Na into the fluid that is rich in SiO2 and H2O, confirmed by electron microprobe analyses. The addition of NaCl causes the upper critical end point on the SiO2-H2O melting curve to migrate to significantly higher pressure. Correspondence between depolymerization and phase separation of SiO2-H2O-NaCl fluids indicates that polymerization plays a fundamental role in producing critical mixing behavior in silicate-fluid systems.

  8. Soluble vs. insoluble fiber

    MedlinePlus

    ... soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in ...

  9. Amorphous solid dispersion enhances permeation of poorly soluble ABT-102: true supersaturation vs. apparent solubility enhancement.

    PubMed

    Frank, Kerstin J; Rosenblatt, Karin M; Westedt, Ulrich; Hölig, Peter; Rosenberg, Jörg; Mägerlein, Markus; Fricker, Gert; Brandl, Martin

    2012-11-01

    Amorphous solid dispersions (ASDs) represent a promising formulation approach for poorly soluble drugs. We explored the formulation-related impact of ASDs on permeation rate, apparent solubility and molecular solubility of the poorly soluble drug ABT-102. The influence of fasted state simulated intestinal fluid (FaSSIF) as dispersion medium was also studied. ASDs were prepared by hot-melt extrusion. Permeation rate was assessed by the Caco-2 transwell assay. Cell viability and barrier integrity were assured by AlamarBlue©, TEER and permeability of the hydrophilic marker carboxyfluorescein. Apparent solubility and molecular solubility were evaluated by using centrifugation and inverse dialysis, respectively. The in vitro permeation rate of ABT-102 from aqueous dispersions of the ASD was found 4 times faster than that from the dispersions of the crystals, while apparent solubility and molecular solubility of ABT-102 were increased. Yet, a further increase in apparent solubility due to micellar solubilization as observed when dispersing the ASD in FaSSIF, did not affect molecular solubility or permeation rate. Overall, a good correlation between permeation rate and molecular solubility but not apparent solubility was seen. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Fluid imbalance

    MedlinePlus

    ... up in the body. This is called fluid overload (volume overload). This can lead to edema (excess fluid in ... Water imbalance; Fluid imbalance - dehydration; Fluid buildup; Fluid overload; Volume overload; Loss of fluids; Edema - fluid imbalance; ...

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

    DOEpatents

    Kelly, Sean M

    2016-09-27

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

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

    DOEpatents

    Kelly, Sean M.

    2017-02-21

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

  13. Experimental determination of synthetic NdPO4 monazite end-member solubility in water from 21°C to 300°C: implications for rare earth element mobility in crustal fluids1 1Associate editor: D. J. Wesolowski

    NASA Astrophysics Data System (ADS)

    Poitrasson, Franck; Oelkers, Eric; Schott, Jacques; Montel, Jean-Marc

    2004-05-01

    The solubility of synthetic NdPO 4 monazite end-member has been determined experimentally from 21 to 300°C in aqueous solutions at pH = 2, and at 21°C and pH = 2 for GdPO 4. Measurements were performed in batch reactors, with regular solution sampling for pH measurement, rare earths and phosphorous analysis by inductively coupled plasma mass spectrometry (ICP-MS) coupled with a desolvation system. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to check that no reprecipitation of secondary phases occurred and that the mineral surfaces remained those of a monazite. Coupled with speciation calculations, measured solution compositions permitted the determination of NdPO 4 and GdPO 4 solubility products which are in general agreement with previous experimental determination on rhabdophane at 25°C, but showing that monazite is more than two orders of magnitude less soluble than inferred on the basis of previous thermodynamic estimates. The temperature evolution from 21 to 300°C of the equilibrium constant (K) of the NdPO 4 monazite end-member dissolution reaction given by: NdPO4( s) ⇆ Nd3++ PO43- can be described by the equation: -log K= 7.621+ 0.04163T+ 1785/T where T is in Kelvins. Integration of this expression permitted the determination of the enthalpy, free energy and entropy of dissolution and formation of the NdPO 4 monazite end-member. Solubility-speciation calculations show that the presence of aqueous ligands, notably fluoride, carbonate or hydroxide in water strongly affect monazite solubility, depending on pH and temperature. These calculations also show that monazite will exhibit retrograde solubility only under acidic conditions from 70°C to 300°C and to a lesser extent in neutral aqueous solutions from 150°C to 300°C. Solubility-speciation calculations performed on natural seafloor vent hydrothermal fluids and on thermal springwaters from granitic areas at aquifer temperature show that these fluids

  14. Membrane-Based Functions in the Origin of Cellular Life

    NASA Technical Reports Server (NTRS)

    Wilson, Michael A.

    2003-01-01

    How simple membrane peptides performed such essential proto-cellular functions as transport of ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilization of energy, and transduction of environmental signals, is a key question in protobiological evolution. On the basis of detailed, molecular-level computer simulations we investigate how these peptides insert into membranes, self-assemble into higher-order structures and acquire functions. We have studied the insertion of an a-helical peptide containing leucine (L) and serine (S) of the form (LSLLLSL)S into a model membrane. The transmembrane state is metastable, and approximately 15 kcal/mol is required to insert the peptide into the membrane. Investigations of dimers formed by (LSLLLSL)S and glycophorin A demonstrate how the favorable free energy of helix association can offset the unfavorable free energy of insertion, leading to self- assembly of peptide helices in the membrane. An example of a self-assembled structure is the tetrameric transmembrane pore of the influenza virus M2 protein, which is an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism and provide guidelines how to reengineering the channel to act as a simple proton pump. In general, emergence of integral membrane proteins appears to be quite feasible and may be easier to envision than the emergence of water-soluble proteins.

  15. A smart membrane based on an antigen-responsive hydrogel.

    PubMed

    Zhang, Rongsheng; Bowyer, Adrian; Eisenthal, Robert; Hubble, John

    2007-07-01

    Hydrogel membranes have been fabricated that incorporate antibody/antigen moieties. The permeability of large solutes through these membranes is dependent on the presence of soluble antigen that can compete with the internal interactions between antibody and antigen leading to an increase in gel mesh size. Specifically, the membrane's structure is based on a dextran backbone grafted with a fluorescein isothiocyanate (FITC) antigen and a sheep anti-FITC IgG antibody. The backbone is covalently cross-linked by conjugated divinyl sulfone (DVS) groups. The gel structure is additionally stabilized by affinity crosslinks formed by biospecific interactions between the bound IgG and FITC. FTIR spectra of the gel are consistent with formation of covalent bonds between cysteine groups in the IgG and DVS groups in the dextran. Results obtained using isothermal titration calorimetry (ITC) confirmed the competitive interaction binding between IgG-FITC-dextran and free sodium fluorescein at pH 5.0. Scanning electron microscopy (SEM) of samples prepared using cryofixation and cryofracturing techniques showed that observed changes in permeability correlate with free fluorescein-dependent structural changes in the gel. Three-dimensional images obtained from confocal laser scanning microscopy show that these changes occur throughout the gel and indicate that SEM results are not artifacts of sample preparation. The permeability of these gels, as shown by blue-dextran (12 kDa) diffusion, increases in response to the presence of free fluorescein of the external medium, which causes competitive displacement of the affinity cross-links. Sequential addition and removal of sodium fluorescein showed that these permeability changes are reversible. (c) 2006 Wiley Periodicals, Inc.

  16. Fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth E.

    1999-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  17. The Solubility of Oxygen and Ozone in Liquids

    NASA Astrophysics Data System (ADS)

    Battino, Rubin; Rettich, Timothy R.; Tominaga, Toshihiro

    1983-04-01

    This review covers the solubility of oxygen and ozone in liquids as a function of temperature and pressure. Solubility data for individual systems were critically evaluated and recommended or tentative values presented in many cases. The trend of solubilities in homologous series or related solvents is discussed. Liquids include water; seawater; aqueous salt solutions; mixed solvents; hydrocarbons; organic compounds containing oxygen, halogen, sulfur, nitrogen, or silicon; olive oil; and human blood. For ozone, only its solubility in water is presented. Key words: aqueous solutions; biological fluids; gas solubility; hydrocarbons; mixed solvents; organic solvents; oxygen; ozone; seawater; water.

  18. The solubility of uranium hexafluoride in perfluoroethers

    SciTech Connect

    Barber, E.J.

    1984-07-15

    The polyperfluoroethers are compatible with uranium hexafluoride (UF/sub 6/) and are suitable for use in diffusion pumps and in mechanical vacuum pumps which rely on oil as both the lubricant and the seal. The UF/sub 6/ is soluble in all fluids with which it is compatible. Because a number of vacuum pumps in the BOP facilities of the GCEP plant employ these perfluoroether oils as the working fluid and have oil chambers which are large, questions have been raised as to the relationships governing the solubility of UF/sub 6/ in these materials and the maximum quantities of UF/sub 6/ which could be dissolved in these oils under credible accident conditions. This report summarizes these solubility relations and the interaction of the UF/sub 6/ solubility and the pumping capability of this type of vacuum pump. It will be shown that, whereas the solubility of UF/sub 6/ in Fomblin Y25 fluoroether fluid under a UF/sub 6/ pressure of 760 torr and at the pump operating temperature of 160/sup 0/F is about 500 g of UF/sub 6/ per liter of oil, the system controls are such as to isolate the system from the pumps before the quantity of UF/sub 6/ dissolved in the perfluoroether exceeds about 10 g of UF/sub 6/ per liter of oil. 13 refs., 7 figs.

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

    DOEpatents

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

    2016-09-27

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

  20. Recent developments in membrane-based separations in biotechnology processes: review.

    PubMed

    Rathore, A S; Shirke, A

    2011-01-01

    Membrane-based separations are the most ubiquitous unit operations in biotech processes. There are several key reasons for this. First, they can be used with a large variety of applications including clarification, concentration, buffer exchange, purification, and sterilization. Second, they are available in a variety of formats, such as depth filtration, ultrafiltration, diafiltration, nanofiltration, reverse osmosis, and microfiltration. Third, they are simple to operate and are generally robust toward normal variations in feed material and operating parameters. Fourth, membrane-based separations typically require lower capital cost when compared to other processing options. As a result of these advantages, a typical biotech process has anywhere from 10 to 20 membrane-based separation steps. In this article we review the major developments that have occurred on this topic with a focus on developments in the last 5 years.

  1. Additive for drilling fluids

    SciTech Connect

    Cates, A.E.

    1983-09-13

    A water-based gas or oil well drilling fluid is disclosed comprising an aqueous clay dispersion containing as a thinner and water loss control agent, the essentially water-soluble product obtained by heating together quebracho, lignite, gilsonite and sulfonating, methylating and causticizing agents.

  2. Supercritical fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth

    1994-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  3. Amyloid Fibril Solubility.

    PubMed

    Rizzi, L G; Auer, S

    2015-11-19

    It is well established that amyloid fibril solubility is protein specific, but how solubility depends on the interactions between the fibril building blocks is not clear. Here we use a simple protein model and perform Monte Carlo simulations to directly measure the solubility of amyloid fibrils as a function of the interaction between the fibril building blocks. Our simulations confirms that the fibril solubility depends on the fibril thickness and that the relationship between the interactions and the solubility can be described by a simple analytical formula. The results presented in this study reveal general rules how side-chain-side-chain interactions, backbone hydrogen bonding, and temperature affect amyloid fibril solubility, which might prove to be a powerful tool to design protein fibrils with desired solubility and aggregation properties in general.

  4. MEMBRANE TECHNOLOGY: OPPORTUNITIES FOR POLYHEDRAL OLIGOMERIC SILSESQUIOXANES (POSS) IN MEMBRANE-BASED SEPARATIONS

    EPA Science Inventory

    Membrane Technology: Opportunities for Polyhedral Oligomeric Silsesquioxanes (POSS?) in Membrane-Based Separations

    Leland M. Vane, Ph.D.
    U.S. Environmental Protection Agency
    Office of Research & Development
    Cincinnati, OH 45268
    Vane.Leland@epa.gov

    A sign...

  5. MEMBRANE TECHNOLOGY: OPPORTUNITIES FOR POLYHEDRAL OLIGOMERIC SILSESQUIOXANES (POSS) IN MEMBRANE-BASED SEPARATIONS

    EPA Science Inventory

    Membrane Technology: Opportunities for Polyhedral Oligomeric Silsesquioxanes (POSS?) in Membrane-Based Separations

    Leland M. Vane, Ph.D.
    U.S. Environmental Protection Agency
    Office of Research & Development
    Cincinnati, OH 45268
    Vane.Leland@epa.gov

    A sign...

  6. Mass spectrometry with direct supercritical fluid injection

    SciTech Connect

    Smith, R.D.; Udseth, H.R.

    1983-12-01

    Direct fluid injection mass spectrometry utilizes supercritical fluids for solvation and transfer of materials to a mass spectrometer chemical ionization (CI) source. Available data suggest that any material soluble in a supercritical fluid is transferred efficiently to the ionization region. Mass spectra are presented for mycotoxins of the trichothecene group obtained by use of supercritical carbon dioxide with isobutane as the CI reagent gas. Direct fluid injection MS/MS is also illustrated for major ions in the isobutane chemical ionization of T-2 toxin. The effect of pressure and temperature upon solubility in supercritical fluids is described and illustrated for diacetoxycirpenol. A potential method is also demonstrated for on-line fraction during MS analysis using pressure to control supercritical fluid solubility. Mass spectra are also presented for polar compounds, using supercritical ammonia, and the extension to complex mixtures is described. The fundamental basis and experimental requirements of the direct fluid injection process are discussed. 34 references, 11 figures, 1 table.

  7. Mass spectrometry with direct supercritical fluid injection

    SciTech Connect

    Smith, R.D.; Udseth, H.R.

    1983-12-01

    Direct fluid injection mass spectrometry utilizes supercritical fluids for solvation and transfer of materials to a mass spectrometer chemical ionization (CI) source. Available data suggest that any material soluble in a supercritical fluid is transferred efficiently to the ionization region. Mass spectra are presented for mycotoxins of the trichothecene group obtained by use of supercritical carbon dioxide with isobutane as the CI reagent gas. Direct fluid injection MS/MS is also illustrated for major ions in the isobutane chemical ionization of T-2 toxin. The effect of pressure and temperature upon solubility in supercritical fluids is described and illustrated for diacetoxyscirpenol. A potential method is also demonstrated for ''on-line fractionation'' during MS analysis using pressure to control supercritical fluid solubility. Mass spectra are also presented for polar compounds, using supercritical ammonia, and the extension to complex mixtures is described. The fundamental basis and experimental requirements of the direct fluid injection process are discussed. 1 figure, 11 tables.

  8. Assessment of Age-Related Changes in Pediatric Gastrointestinal Solubility.

    PubMed

    Maharaj, Anil R; Edginton, Andrea N; Fotaki, Nikoletta

    2016-01-01

    Compound solubility serves as a surrogate indicator of oral biopharmaceutical performance. Between infancy and adulthood, marked compositional changes in gastrointestinal (GI) fluids occur. This study serves to assess how developmental changes in GI fluid composition affects compound solubility. Solubility assessments were conducted in vitro using biorelevant media reflective of age-specific pediatric cohorts (i.e., neonates and infants). Previously published adult media (i.e., FaSSGF, FeSSGF, FaSSIF.v2, and FeSSIF.v2) were employed as references for pediatric media development. Investigations assessing age-specific changes in GI fluid parameters (i.e., pepsin, bile acids, pH, osmolality, etc.) were collected from the literature and served to define the composition of neonatal and infant media. Solubility assessments at 37 °C were conducted for seven BCS Class II compounds within the developed pediatric and reference adult media. For six of the seven compounds investigated, solubility fell outside an 80-125% range from adult values in at least one of the developed pediatric media. This result indicates a potential for age-related alterations in oral drug performance, especially for compounds whose absorption is delimited by solubility (i.e., BCS Class II). Developmental changes in GI fluid composition can result in relevant discrepancies in luminal compound solubility between children and adults.

  9. Biorelevant solubility of poorly soluble drugs: rivaroxaban, furosemide, papaverine and niflumic acid.

    PubMed

    Takács-Novák, Krisztina; Szőke, Vera; Völgyi, Gergely; Horváth, Péter; Ambrus, Rita; Szabó-Révész, Piroska

    2013-09-01

    In this work the biorelevant solubility of four drugs representing different acid-base property, wide range of lipohilicity and low aqueous solubility was studied. The equilibrium solubility of rivaroxaban (non-ionizable), furosemide (acid), papaverine (base) and niflumic acid (ampholyte) was determined in simulated gastric fluid (SGF pH 1.2), in simulated intestinal fluid fasted state (FaSSIF pH 6.5) and fed state (FeSSIF pH 5.0) and their corresponding blank buffers at a temperature of 37 °C using saturation shake-flask method. The concentration was measured by optimized HPLC analysis. The solubilizing effect of bile acid/lipid micelles as additive components of biorelevent media (BRM) is expressed with the solubility ratio (SR: SBRM/Sblank buffer) and the food effect was estimated from SFeSSIF/SFaSSIF coefficient. It was revealed that ionization plays primarily role in solubility of compounds which undergo ionization in BRM. The solubilizing effect in FaSSIF was marginal for the neutral compound (rivaroxaban) and for molecules are anionic at pH 6.5 (furosemide and niflumic acid). The higher concentration of solubilizing agents in FeSSIF improved the solubility of papaverine carrying positive charge and niflumic acid being partially zwitterionic at pH 5.0.

  10. Inter-subject variability in intestinal drug solubility.

    PubMed

    Rabbie, Sarit Cohen; Flanagan, Talia; Martin, Paul D; Basit, Abdul W

    2015-05-15

    Variability in oral drug absorption is a well-known phenomenon, but it is often overlooked for its potential effects in oral drug delivery. Understanding the mechanisms behind absorption variability is crucial to understanding and predicting drug pharmacokinetics. In this study, the solubility of furosemide and dipyridamole - drugs known to have highly variable oral bioavailabilities - was investigated in individual ileostomy fluids from 10 subjects with ulcerative colitis. For comparison, drug solubility was also determined in pooled upper gastrointestinal fluids from healthy human subjects and simulated intestinal fluids. Ileostomy fluid characterization revealed high variability in buffer capacity and to a lesser degree for pH. Drug solubility in ileostomy fluids showed high variability. Correlation analysis revealed that dipyridamole solubility in these fluids is pH-dependent, whereas furosemide solubility was highly correlated to buffer capacity and pH. The implications of these results might partly explain the high variability in bioavailability in vivo, assuming that most of the observed variability is due to the absorption, and not the elimination, process. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Cancer and soluble FAS.

    PubMed

    Abbasova, S G; Vysotskii, M M; Ovchinnikova, L K; Obusheva, M N; Digaeva, M A; Britvin, T A; Bahoeva, K A; Karabekova, Z K; Kazantzeva, I A; Mamedov, U R; Manuchin, I B; Davidov, M I

    2009-10-01

    A test system developed by the authors was used to measure serum concentrations of soluble Fas in patients with malignant and benign tumors of different location and morphology. Relationships between soluble Fas levels and the main clinical and morphological characteristics of cancer were evaluated. It is proven that the concentrations and incidence of detection of soluble Fas in the sera of patients with tumors are significantly higher than in normal subjects. No appreciable differences in the concentrations of soluble Fas were detected in malignant and benign tumors of the mammary gland, bones, ovaries, and adrenals. In thyroid cancer, soluble Fas levels were higher than in benign and hyperplastic processes in this organ. High level of soluble Fas is associated with late stages of the disease (ovarian cancer, cancer of the corpus uteri, adrenocortical and colorectal cancer) and with poor differentiation of the tumor (ovarian cancer and cancer of the corpus uteri), with local metastases (colorectal and adrenocortical cancer), and with tumor invasion into the myometrial tissue, intestinal wall, and adjacent tissues (cancer of the corpus uteri and colorectal cancer). A significantly high level of soluble Fas was detected in colorectal and adrenocortical cancer in the presence of at least 2 local metastases. Soluble Fas levels depended on tumor histogenesis in malignant and benign ovarian tumors. High concentration of soluble Fas was detected in large tumors in patients with ovarian cancer, cancer of the corpus uteri, colorectal cancer, thyroid cancer and adenoma, and in adrenocortical cancer. Initially high levels of soluble Fas are characteristic of patients whose tumors are little sensitive to nonadjuvant radiotherapy. The overall 5-year survival of patients with low levels of soluble Fas is better in osteosarcoma, cancer of the corpus uteri, ovarian and adrenocortical cancer.

  12. What Variables Affect Solubility?

    ERIC Educational Resources Information Center

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  13. Applications of Solubility Data

    ERIC Educational Resources Information Center

    Tomkins, Reginald P. T.

    2008-01-01

    This article describes several applications of the use of solubility data. It is not meant to be exhaustive but rather to show that knowledge of solubility data is required in a variety of technical applications that assist in the design of chemical processes. (Contains 3 figures and 1 table.)

  14. What Variables Affect Solubility?

    ERIC Educational Resources Information Center

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  15. Applications of Solubility Data

    ERIC Educational Resources Information Center

    Tomkins, Reginald P. T.

    2008-01-01

    This article describes several applications of the use of solubility data. It is not meant to be exhaustive but rather to show that knowledge of solubility data is required in a variety of technical applications that assist in the design of chemical processes. (Contains 3 figures and 1 table.)

  16. Supercritical fluid thermodynamics for coal processing

    SciTech Connect

    van Swol, F. . Dept. of Chemical Engineering); Eckert, C.A. . School of Chemical Engineering)

    1988-09-15

    The main objective of this research is to develop an equation of state that can be used to predict solubilities and tailor supercritical fluid solvents for the extraction and processing of coal. To meet this objective we have implemented a two-sided. approach. First, we expanded the database of model coal compound solubilities in higher temperature fluids, polar fluids, and fluid mixtures systems. Second, the unique solute/solute, solute/cosolvent and solute/solvent intermolecular interactions in supercritical fluid solutions were investigated using spectroscopic techniques. These results increased our understanding of the molecular phenomena that affect solubility in supercritical fluids and were significant in the development of an equation of state that accurately reflects the true molecular makeup of the solution. (VC)

  17. A comparative study on the membrane based palm oil mill effluent (POME) treatment plant.

    PubMed

    Ahmad, A L; Chong, M F; Bhatia, S

    2009-11-15

    The discharge of palm oil mill effluent (POME) causes serious pollution problems and the membrane based POME treatment is suggested as a solution. Three different designs, namely Design A, B and C distinguished by their different types and orientations of membrane system are proposed. The results at optimum condition proved that the quality of the recovered water for all the designs met the effluent discharge standards imposed by the Department of Environment (DOE). The economic analysis at the optimum condition shows that the total treatment cost for Design A was the highest (RM 115.11/m(3)), followed by Design B (RM 23.64/m(3)) and Design C (RM 7.03/m(3)). In this study, the membrane system operated at high operating pressure with low membrane unit cost is preferable. Design C is chosen as the optimal design for the membrane based POME treatment system based on the lowest total treatment cost.

  18. The use of conducting polymers in membrane-based separations: a review and recent developments.

    PubMed

    Pellegrino, John

    2003-03-01

    As a material family, pi-conjugated polymers (also known as intrinsically conductive polymers) elicit the possibility of both exploiting the chemical and physical attributes of the polymer for membrane-based separations and incorporating its electronic and electrochemical properties to enhance the separation figures-of-merit. This review article, although by no means comprehensive, provides a current snapshot of the investigations from many research laboratories in the use of conducting polymers for membrane-based separations. The review focuses primarily on polyaniline, polypyrrole, and substituted-polythiophene and includes applications in gas separations, liquid (and/or vapor) separations, and ion separations. Additionally, we discuss the broad challenges and accomplishments in membrane formation from conducting polymers.

  19. Well servicing fluid

    SciTech Connect

    Liao, A.

    1991-07-02

    This patent describes a well servicing fluid. It comprises an aqueous medium from about 0.2 to about 5 pounds per barrel of a partially hydrolyzed homopolymer of acrylamide having an average molecular weight greater than 1 million, and a calcium-controlling additive. It comprises from about 0.1 to about 2.5 pounds per barrel of the fluid of an alkali metal bicarbonate, from about 0.1 to about 2.5 pounds per barrel of the fluid of a water-soluble, carboxylic acid, and from about 0.1 to about 1.5 pounds per barrel of the fluid of a terpolymer containing from about 40 to about 70% by weight acrylamide, from about 20 to about 40% by weight of an acrylic acid and from about 5 to about 20% by weight of 2-acrylamido-2-methylpropanesulfonic acid, the terpolymer having an average molecular weight of from about 5 to about 10 million.

  20. Development of a two-stage membrane-based wash-water reclamation subsystem

    NASA Technical Reports Server (NTRS)

    Mccray, S. B.

    1988-01-01

    A two-stage membrane-based subsystem was designed and constructed to enable the recycle of wash waters generated in space. The first stage is a fouling-resistant tube-side-feed hollow-fiber ultrafiltration module, and the second stage is a spiral-wound reverse-osmosis module. Throughout long-term tests, the subsystem consistently produced high-quality permeate, processing actual wash water to 95 percent recovery.

  1. Development of a two-stage membrane-based wash-water reclamation subsystem

    NASA Technical Reports Server (NTRS)

    Mccray, S. B.

    1988-01-01

    A two-stage membrane-based subsystem was designed and constructed to enable the recycle of wash waters generated in space. The first stage is a fouling-resistant tube-side-feed hollow-fiber ultrafiltration module, and the second stage is a spiral-wound reverse-osmosis module. Throughout long-term tests, the subsystem consistently produced high-quality permeate, processing actual wash water to 95 percent recovery.

  2. Membrane-based lateral flow immunochromatographic strip with nanoparticles as reporters for detection: A review.

    PubMed

    Huang, Xiaolin; Aguilar, Zoraida P; Xu, Hengyi; Lai, Weihua; Xiong, Yonghua

    2016-01-15

    Membrane-based lateral flow immunochromatographic strip (LFICS) is widely used in various fields because of its simplicity, rapidity (detection within 10min), and low cost. However, early designs of membrane-based LFICS for preliminary screening only provide qualitative ("yes/no" signal) or semi-quantitative results without quantitative information. These designs often suffer from low-signal intensity and poor sensitivity and are only capable of single analyte detection, not simultaneous multiple detections. The performance of existing techniques used for detection using LFICS has been considerably improved by incorporating different kinds of nanoparticles (NPs) as reporters. NPs can serve as alternative labels and improve analytical sensitivity or limit of detection of LFICS because of their unique properties, such as optical absorption, fluorescence spectra, and magnetic properties. The controlled manipulation of NPs allows simultaneous or multiple detections by using membrane-based LFICS. In this review, we discuss how colored (e.g., colloidal gold, carbon, and colloidal selenium NPs), luminescent (e.g., quantum dots, up-converting phosphor NPs, and dye-doped NPs), and magnetic NPs are integrated into membrane-based LFICS for the detection of target analytes. Gold NPs are also featured because of their wide applications. Different types and unique properties of NPs are briefly explained. This review focuses on examples of NP-based LFICS to illustrate novel concepts in various devices with potential applications as screening tools. This review also highlights the superiority of NP-based approaches over existing conventional strategies for clinical analysis, food safety, and environmental monitoring. This paper is concluded by a short section on future research trends regarding NP-based LFICS. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Remediation of textile effluents by membrane based treatment techniques: a state of the art review.

    PubMed

    Dasgupta, Jhilly; Sikder, Jaya; Chakraborty, Sudip; Curcio, Stefano; Drioli, Enrico

    2015-01-01

    The textile industries hold an important position in the global industrial arena because of their undeniable contributions to basic human needs satisfaction and to the world economy. These industries are however major consumers of water, dyes and other toxic chemicals. The effluents generated from each processing step comprise substantial quantities of unutilized resources. The effluents if discharged without prior treatment become potential sources of pollution due to their several deleterious effects on the environment. The treatment of heterogeneous textile effluents therefore demands the application of environmentally benign technology with appreciable quality water reclamation potential. These features can be observed in various innovative membrane based techniques. The present review paper thus elucidates the contributions of membrane technology towards textile effluent treatment and unexhausted raw materials recovery. The reuse possibilities of water recovered through membrane based techniques, such as ultrafiltration and nanofiltration in primary dye houses or auxiliary rinse vats have also been explored. Advantages and bottlenecks, such as membrane fouling associated with each of these techniques have also been highlighted. Additionally, several pragmatic models simulating transport mechanism across membranes have been documented. Finally, various accounts dealing with techno-economic evaluation of these membrane based textile wastewater treatment processes have been provided.

  4. Theoretical Analysis on Mechanical Deformation of Membrane-Based Photomask Blanks

    NASA Astrophysics Data System (ADS)

    Marumoto, Kenji; Aya, Sunao; Yabe, Hedeki; Okada, Tatsunori; Sumitani, Hiroaki

    2012-04-01

    Membrane-based photomask is used in proximity X-ray lithography including that in LIGA (Lithographie, Galvanoformung und Abformung) process, and near-field photolithography. In this article, out-of-plane deformation (OPD) and in-plane displacement (IPD) of membrane-based photomask blanks are theoretically analyzed to obtain the mask blanks with flat front surface and low stress absorber film. First, we derived the equations of OPD and IPD for the processing steps of membrane-based photomask such as film deposition, back-etching and bonding, using a theory of symmetrical bending of circular plates with a coaxial circular hole and that of deformation of cylinder under hydrostatic pressure. The validity of the equations was proved by comparing the calculation results with experimental ones. Using these equations, we investigated the relation between the geometry of the mask blanks and the distortions generally, and gave the criterion to attain the flat front surface. Moreover, the absorber stress-bias required to obtain zero-stress on finished mask blanks was also calculated and it has been found that only little stress-bias was required for adequate hole size of support plate.

  5. A simple cellulose acetate membrane-based small lanes technique for protein electrophoresis.

    PubMed

    Na, Na; Liu, Tingting; Yang, Xiaojun; Sun, Binjie; Ouyang, Jenny; Ouyang, Jin

    2012-08-01

    Combining electrophoresis with a cellulose acetate membrane-based technique, we developed a simple and low-cost method, named cellulose acetate membrane-based small lanes (CASL), for protein electrophoresis. A home-made capillary plotter controlled by a 3D moving stage was used to create milli-to-micro channels by printing poly(dimethylsiloxane) on to a hydrophilic cellulose acetate membrane. In the hydrophilic channels, 5 nL protein mixture was separated on the basis of electro-migration under an electric field. Compared with polyacrylamide gel electrophoresis (PAGE), CASL resulted in higher protein signal intensity for separation of mixtures containing the same mass of protein. The platform was easily fabricated at low cost (approx. $0.005 for each 1-mm-wide channel), and separation of three protein mixtures was completed in 15 min. Both electrophoresis time and potential affected the separation. Rather than chromatographic separation, this method accomplished application of microchannel techniques for cellulose acetate membrane-based protein electrophoresis. It has potential in proteomic analysis, especially for rapid, low-cost, and low-volume sample analysis in clinical diagnosis.

  6. An Environmentally Friendly Process Involving Refining and Membrane-Based Electrolysis for Magnesium Recovery from Partially Oxidized Scrap Alloy

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2013-10-01

    Magnesium is recovered from partially oxidized scrap alloy by combining refining and solid oxide membrane (SOM) electrolysis. In this combined process, a molten salt eutectic flux (45 wt.% MgF2-55 wt.% CaF2) containing 10 wt.% MgO and 2 wt.% YF3 was used as the medium for magnesium recovery. During refining, magnesium and its oxide are dissolved from the scrap into the molten flux. Forming gas is bubbled through the flux and the dissolved magnesium is removed via the gas phase and condensed in a separate condenser at a lower temperature. The molten flux has a finite solubility for magnesium and acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium recovered has high purity. After refining, SOM electrolysis is performed in the same reactor to enable electrolysis of the dissolved magnesium oxide in the molten flux producing magnesium at the cathode and oxygen at the SOM anode. During SOM electrolysis, it is necessary to decrease the concentration of the dissolved magnesium in the flux to improve the faradaic current efficiency and prevent degradation of the SOM. Thus, for both refining and SOM electrolysis, it is very important to measure and control the magnesium solubility in the molten flux. High magnesium solubility facilitates refining whereas lower solubility benefits the SOM electrolysis process. Computational fluid dynamics modeling was employed to simulate the flow behavior of the flux stirred by the forming gas. Based on the modeling results, an optimized design of the stirring tubes and its placement in the flux are determined for efficiently removing the dissolved magnesium and also increasing the efficiency of the SOM electrolysis process.

  7. What Should We Teach Beginners about Solubility and Solubility Products?

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    1998-01-01

    Argues that consideration should be given to whether teaching solubility product calculations is at all useful. Claims that experienced teachers seriously misunderstand and misuse solubility product calculations. (DDR)

  8. What Should We Teach Beginners about Solubility and Solubility Products?

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    1998-01-01

    Argues that consideration should be given to whether teaching solubility product calculations is at all useful. Claims that experienced teachers seriously misunderstand and misuse solubility product calculations. (DDR)

  9. Experimental measurement of solid solutes solubility in nanofluids

    NASA Astrophysics Data System (ADS)

    Fard, Manouchehr Manouchehrian; Beiki, Hossein

    2017-04-01

    The solubility of benzoic and salicylic acids was measured at a temperature range from 293 to 333 K in two types of water based nanofluids employed as the solvent. Silica and γ-alumina nanoparticles with volume concentrations of 0.025, 0.05, 0.1, 0.2 and 0.4 % were dispersed into de-ionized water as the based fluid. The results revealed that the solubility of nanofluid followed the same trend as pure water solubility with increasing temperature. At low temperatures, below 330 K for γ-Al2O3 nanofluids and 323 K for SiO2 nanofluids, nanoparticles had no effect on solubility, but by increasing the temperature, nanofluid solubility decreased. The maximum reduction in the solubility of compounds was observed at the temperature of 333 K and in 0.1 % γ-Alumina nanofluid and 0.025 % Silica nanofluids. Nanofluids solubility decreased up to a critical nanoparticles concentration while increased by increasing nanoparticles concentration further. The maximum reduction of nanofluids solubility at critical concentration was about 12.43 % for salicylic acid and 10.24 % for benzoic acid in 0.025 % SiO2 nanofluid. Nanofluids solubility was found to be strongly dependent on nanoparticles size. Bigger nanoparticles were more effective than smaller ones on nanofluids solubility.

  10. Experimental measurement of solid solutes solubility in nanofluids

    NASA Astrophysics Data System (ADS)

    Fard, Manouchehr Manouchehrian; Beiki, Hossein

    2016-08-01

    The solubility of benzoic and salicylic acids was measured at a temperature range from 293 to 333 K in two types of water based nanofluids employed as the solvent. Silica and γ-alumina nanoparticles with volume concentrations of 0.025, 0.05, 0.1, 0.2 and 0.4 % were dispersed into de-ionized water as the based fluid. The results revealed that the solubility of nanofluid followed the same trend as pure water solubility with increasing temperature. At low temperatures, below 330 K for γ-Al2O3 nanofluids and 323 K for SiO2 nanofluids, nanoparticles had no effect on solubility, but by increasing the temperature, nanofluid solubility decreased. The maximum reduction in the solubility of compounds was observed at the temperature of 333 K and in 0.1 % γ-Alumina nanofluid and 0.025 % Silica nanofluids. Nanofluids solubility decreased up to a critical nanoparticles concentration while increased by increasing nanoparticles concentration further. The maximum reduction of nanofluids solubility at critical concentration was about 12.43 % for salicylic acid and 10.24 % for benzoic acid in 0.025 % SiO2 nanofluid. Nanofluids solubility was found to be strongly dependent on nanoparticles size. Bigger nanoparticles were more effective than smaller ones on nanofluids solubility.

  11. Learning about Solubility

    ERIC Educational Resources Information Center

    Salinas, Dino G.; Reyes, Juan G.

    2015-01-01

    Qualitative questions are proposed to assess the understanding of solubility and some of its applications. To improve those results, a simple quantitative problem on the precipitation of proteins is proposed.

  12. Learning about Solubility

    ERIC Educational Resources Information Center

    Salinas, Dino G.; Reyes, Juan G.

    2015-01-01

    Qualitative questions are proposed to assess the understanding of solubility and some of its applications. To improve those results, a simple quantitative problem on the precipitation of proteins is proposed.

  13. Solubility of Organic Compounds

    ERIC Educational Resources Information Center

    James, K. C.

    1972-01-01

    Outlines factors to be considered in choosing suitable solvents for non-electrolytes and salts of weak acids and bases. Describes how, in some simple situation, the degree of solubility can be estimated. (Author/DF)

  14. Protein solubility modeling

    NASA Technical Reports Server (NTRS)

    Agena, S. M.; Pusey, M. L.; Bogle, I. D.

    1999-01-01

    A thermodynamic framework (UNIQUAC model with temperature dependent parameters) is applied to model the salt-induced protein crystallization equilibrium, i.e., protein solubility. The framework introduces a term for the solubility product describing protein transfer between the liquid and solid phase and a term for the solution behavior describing deviation from ideal solution. Protein solubility is modeled as a function of salt concentration and temperature for a four-component system consisting of a protein, pseudo solvent (water and buffer), cation, and anion (salt). Two different systems, lysozyme with sodium chloride and concanavalin A with ammonium sulfate, are investigated. Comparison of the modeled and experimental protein solubility data results in an average root mean square deviation of 5.8%, demonstrating that the model closely follows the experimental behavior. Model calculations and model parameters are reviewed to examine the model and protein crystallization process. Copyright 1999 John Wiley & Sons, Inc.

  15. Optimizing solubility: kinetic versus thermodynamic solubility temptations and risks.

    PubMed

    Saal, Christoph; Petereit, Anna Christine

    2012-10-09

    The aim of this study was to assess the usefulness of kinetic and thermodynamic solubility data in guiding medicinal chemistry during lead optimization. The solubility of 465 research compounds was measured using a kinetic and a thermodynamic solubility assay. In the thermodynamic assay, polarized-light microscopy was used to investigate whether the result referred to the crystalline or to the amorphous compound. From the comparison of kinetic and thermodynamic solubility data it was noted that kinetic solubility measurements frequently yielded results which show considerably higher solubility compared to thermodynamic solubility. This observation is ascribed to the fact that a kinetic solubility assay typically delivers results which refer to the amorphous compound. In contrast, results from thermodynamic solubility determinations more frequently refer to a crystalline phase. Accordingly, thermodynamic solubility data--especially when used together with an assessment of the solid state form--are deemed to be more useful in guiding solubility optimization for research compounds.

  16. Membrane-based torque magnetometer: Enhanced sensitivity by optical readout of the membrane displacement.

    PubMed

    Blankenhorn, M; Heintze, E; Slota, M; van Slageren, J; Moores, B A; Degen, C L; Bogani, L; Dressel, M

    2017-09-01

    The design and realization of a torque magnetometer is reported that reads the deflection of a membrane by optical interferometry. The compact instrument allows for low-temperature measurements of tiny crystals less than a microgram with a significant improvement in sensitivity, signal-to-noise ratio as well as data acquisition time compared with conventional magnetometry and offers an enormous potential for further improvements and future applications in different fields. Magnetic measurements on single-molecule magnets demonstrate the applicability of the membrane-based torque magnetometer.

  17. Freestanding eggshell membrane-based electrodes for high-performance supercapacitors and oxygen evolution reaction

    NASA Astrophysics Data System (ADS)

    Geng, Jing; Wu, Hao; Al-Enizi, Abdullah M.; Elzatahry, Ahmed A.; Zheng, Gengfeng

    2015-08-01

    A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific capacitances at current densities from 1 to 20 A g-1, with excellent capacitance retention (>90%) at 10 A g-1 for over 10 000 cycles. When employed as an OER catalyst, this eggshell membrane-based electrode exhibits an OER onset potential of 1.53 V vs. the reversible hydrogen electrode (RHE), and a stable catalytic current density of 20 mA cm-2 at 1.65 V vs. the RHE.A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific

  18. In vitro dynamic solubility test: influence of various parameters.

    PubMed Central

    Thélohan, S; de Meringo, A

    1994-01-01

    This article discusses the dissolution of mineral fibers in simulated physiological fluids (SPF), and the parameters that affect the solubility measurement in a dynamic test where an SPF runs through a cell containing fibers (Scholze and Conradt test). Solutions simulate either the extracellular fluid (pH 7.6) or the intracellular fluid (pH 4.5). The fibers have various chemical compositions and are either continuously drawn or processed as wool. The fiber solubility is determined by the amount of SiO2 (and occasionally other ions) released in the solution. Results are stated as percentage of the initial silica content released or as dissolution rate v in nm/day. The reproducibility of the test is higher with the less soluble fibers (10% solubility), than with highly soluble fibers (20% solubility). The influence of test parameters, including SPF, test duration, and surface area/volume (SA/V), has been studied. The pH and the inorganic buffer salts have a major influence: industrial glasswool composition is soluble at pH 7.6 but not at pH 4.5. The opposite is true for rock- (basalt) wool composition. For slightly soluble fibers, the dissolution rate v remains constant with time, whereas for highly soluble fibers, the dissolution rate decreases rapidly. The dissolution rates believed to occur are v1, initial dissolution rate, and v2, dissolution rate of the residual fibers. The SA of fibers varies with the mass of the fibers tested, or with the fiber diameter at equal mass. Volume, V, is the chosen flow rate. An increase in the SA/V ratio leads to a decrease in the dissolution rate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7882964

  19. Freestanding eggshell membrane-based electrodes for high-performance supercapacitors and oxygen evolution reaction.

    PubMed

    Geng, Jing; Wu, Hao; Al-Enizi, Abdullah M; Elzatahry, Ahmed A; Zheng, Gengfeng

    2015-09-14

    A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific capacitances at current densities from 1 to 20 A g(-1), with excellent capacitance retention (>90%) at 10 A g(-1) for over 10,000 cycles. When employed as an OER catalyst, this eggshell membrane-based electrode exhibits an OER onset potential of 1.53 V vs. the reversible hydrogen electrode (RHE), and a stable catalytic current density of 20 mA cm(-2) at 1.65 V vs. the RHE.

  20. Metal solubility enhancing peptides derived from barley protein.

    PubMed

    Eckert, Ewelina; Bamdad, Fatemeh; Chen, Lingyun

    2014-09-15

    Mineral supplements are required to be soluble as their bioavailability is highly correlated to their solubility in body fluids. In this study, metal binding capacity of barley protein hydrolysates and their purified fractions was investigated and expressed as increase in solubility of metal ions. Metal ions in the presence of hydrolysates exhibited a remarkable increase in solubility: 118, 32, 10, 29 and 35-fold for Fe(2+), Fe(3+), Ca(2+), Cu(2+) and Zn(2+), respectively. A mixture of low molecular weight peptides possesses a synergistic combination of both charged and hydrophobic residues and achieves the best binding metal ions. Electrostatic interactions via charged side chains and coordination binding with His and Cys, initially attract the metal ions and, afterward, hydrophobic interactions and aromatic ring stacking stabilize the positioning of metal ions in the structure of the peptide. Barley hordein hydrolysates show potential as dietary supplements that enhance both mineral solubility and bioavailability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Rocky core solubility in Jupiter and giant exoplanets.

    PubMed

    Wilson, Hugh F; Militzer, Burkhard

    2012-03-16

    Gas giants are believed to form by the accretion of hydrogen-helium gas around an initial protocore of rock and ice. The question of whether the rocky parts of the core dissolve into the fluid H-He layers following formation has significant implications for planetary structure and evolution. Here we use ab initio calculations to study rock solubility in fluid hydrogen, choosing MgO as a representative example of planetary rocky materials, and find MgO to be highly soluble in H for temperatures in excess of approximately 10,000 K, implying the potential for significant redistribution of rocky core material in Jupiter and larger exoplanets.

  2. Gastrointestinal characterisation and drug solubility determination in animals.

    PubMed

    Merchant, Hamid A; Afonso-Pereira, Francisco; Rabbie, Sarit C; Youssef, Sandy A; Basit, Abdul W

    2015-05-01

    To characterise the gastrointestinal (GI) environment in rat, rabbit and pig for the purpose of determining their utility as animal models for drug delivery in humans. GI fluid samples were characterised for osmolality, surface tension, pH and buffer capacity. The solubility of two model drugs, mesalazine (ionisable) and prednisolone (unionisable), were also measured and the results were correlated to the physicochemical fluid data. The solubility of the ionisable drug mesalazine was positively correlated to the GI pH in all three species and was significantly influenced by the pH difference. In contrast, the solubility of the unionisable compound prednisolone was not correlated significantly to the changes in pH, buffer capacity, osmolality or surface tension. In general, the solubility of prednisolone was constant irrespective of the location of the sample in the gut from rabbit and pig; however, an unusual trend was observed for the solubility of prednisolone in rats. The results suggest that solubility of ionisable drugs or pH-responsive formulations is significantly influenced by the differences in pH along the GI tract and inter-species differences. It was also found that the data on the GI solubility of prednisolone (a neutral compound) in rats might overestimate its true value in humans. © 2015 Royal Pharmaceutical Society.

  3. Combined dispersant fluid loss control additives

    SciTech Connect

    Villa, J. L.; Zeiner, R. N.

    1985-12-31

    Water soluble polymer compositions containing polyacrylic acid and copolymer of itaconic acid and acrylamide are useful as combined dispersant and fluid loss control additives for aqueous drilling fluids, particularly fresh water, gypsum and seawater muds. An example is a polymer composition containing about 80% by weight polyacrylic acid and about 20% by weight copolymer of itaconic acid and acrylamide in its ammonium salt form.

  4. Transport relaxation processes in supercritical fluids

    NASA Astrophysics Data System (ADS)

    Jonas, J.

    The technique for solubility measurements of solids in compressed supercritical fluids using NMR and theoretical analysis of experimental data on collision induced scattering were examined. Initial tests for a determination of solid solubilities in supercritical fluids without mixing were previously described and these preparations have continued. Super critical carbon dioxide dissolving naphthalene, for which solubility data is already available (M. McHugh, M.E. Paulaitis, J. Chem. Eng. Data, Vol. 25 (4), 1980) is being studied. This initial testing of the NMR technique for measuring solubilities in a well characterized system should prove very valuable for our later determinations with the proposed mixing probe. Systematic experimental studies of collision induced spectra in several supercritical fluids using both Raman and Rayleigh scattering are continued. The experimental work on SF6 and CH4 was finished and the experimental data testing of the various theoretical models for collision induced scattering is being analyzed.

  5. Soluble BACE-1 Activity and sAβPPβ Concentrations in Alzheimer's Disease and Age-Matched Healthy Control Cerebrospinal Fluid from the Alzheimer's Disease Neuroimaging Initiative-1 Baseline Cohort.

    PubMed

    Savage, Mary J; Holder, Daniel J; Wu, Guoxin; Kaplow, June; Siuciak, Judith A; Potter, William Z

    2015-01-01

    β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) plays an important role in the development of Alzheimer's disease (AD), freeing the amyloid-β (Aβ) N-terminus from the amyloid-β protein precursor (AβPP), the first step in Aβ formation. Increased BACE1 activity in AD brain or cerebrospinal fluid (CSF) has been reported. Other studies, however, found either no change or a decrease with AD diagnosis in either BACE1 activity or sAβPPβ, the N-terminal secreted product of BACE1 (sBACE1) activity on AβPP. Here, sBACE1 enzymatic activity and secreted AβPPβ (sAβPPβ) were measured in Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1) baseline CSF samples and no statistically significant changes were found in either measure comparing healthy control, mild cognitively impaired, or AD individual samples. While CSF sBACE1 activity and sAβPPβ demonstrated a moderate yet significant degree of correlation with each other, there was no correlation of either analyte to CSF Aβ peptide ending at residue 42. Surprisingly, a stronger correlation was demonstrated between CSF sBACE1 activity and tau, which was comparable to that between CSF Aβ₄₂ and tau. Unlike for these latter two analytes, receiver-operator characteristic curves demonstrate that neither CSF sBACE1 activity nor sAβPPβ concentrations can be used to differentiate between healthy elderly and AD individuals.

  6. [Study on solubility of Chinese herbal compound by solubility parameter].

    PubMed

    Wu, Dezhi; Chen, Lihua; Wang, Sen; Zhu, Weifeng; Guan, Yongmei

    2010-02-01

    To demonstrate the solubility of Chinese herbal compound with solubility parameters. The solubility parameters of Liangfu effective components and Liangfu compound were determined by inverse gas chromatograph (IGC) and group contribution. Hansen ball was plotting by HSPiP, which could be used to investigate the solubility of Liangfu effective components and Liangfu compound in different solvents. And the results were verified by approximate solubility. Liangfu effective components and Liangfu compound could be dissolved in chloroform, ethyl acetate, acetone, octanol and ether, and were slightly soluble in glycerol, methanol, ethanol and propanediol, but could not be dissolved in water. They were all liposoluble, and the results were the same as the test results of the approximate solubility. The solubility of Chinese herbal compound can be expressed by solubility parameters, and it is accurate, convenient and visual.

  7. Uranium, soluble salts

    Integrated Risk Information System (IRIS)

    Uranium , soluble salts ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  8. Nickel, soluble salts

    Integrated Risk Information System (IRIS)

    Nickel , soluble salts ; CASRN Various Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  9. Fluorine (soluble fluoride)

    Integrated Risk Information System (IRIS)

    Fluorine ( soluble fluoride ) ; CASRN 7782 - 41 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  10. Carbon Dioxide: The Other Planetary Fluid

    NASA Astrophysics Data System (ADS)

    Glaser, S.; Gamez, D.; Shock, E.

    2016-12-01

    Cometary and interstellar ices have carbon dioxide to water mole ratios of up to 0.3. When melted, such high levels of carbon dioxide cannot all be dissolved in the aqueous phase and instead partition into a CO2-rich (carbonic) fluid. This implies that during the accretion and formation of planetary systems carbonic fluids are not only possible, but common. In fact, they make up the atmosphere of Venus, are found bubbling out of Champagne Vent in the Pacific Ocean, and are documented by metamorphic fluid inclusions. Examination of phase diagrams reveals the conditions where carbonic fluids will exist or predominate. Carbonic fluids are predicted to exist in Earth's subduction zones and under the ice of small ocean worlds. CO2 had previously been shown to completely dissolve into NH­­3­-H­­2O oceans on small icy bodies by forming ammonium carbonate, but the newer measurements of CO2­ abundances indicate that not all of the CO2 can partition into the aqueous fluid as ammonium carbonate. The remaining CO2 would necessarily form a separate carbonic fluid making it likely that liquid CO2 would be a major oceanic component on some small icy bodies. The enhanced solubility of nonpolar and slightly polar organic compounds in carbonic fluids relative to aqueous fluids means that generation, transport, and deposition processes can be greatly enhanced in those cases where carbonic fluids occur. As an example, the solubility of benzoic acid, a polar compound, is about an order of magnitude greater in carbonic than in aqueous fluids, which is surprising given that water is a polar solvent and carbon dioxide is a nonpolar solvent. Anthracene, a nonpolar compound, has an even greater solubility difference between carbonic and aqueous fluids at approximately four orders of magnitude. Highly polar compounds, including most of the building blocks of life, are more soluble in aqueous fluids than in carbonic fluids. The solubility difference of organic molecules in carbonic

  11. Multifunctional membranes based on spinning technologies: the synergy of nanofibers and nanoparticles

    NASA Astrophysics Data System (ADS)

    Roso, Martina; Sundarrajan, Subramanian; Pliszka, Damian; Ramakrishna, Seeram; Modesti, Michele

    2008-07-01

    A multicomponent membrane based on polysulfone nanofibers and titanium dioxide nanoparticles is produced by the coupling of electrospinning and electrospraying techniques. The manufactured product can satisfy a number of conflicting requirements begetting its technical and functional versatility as well as the reliability of the process. As nanoparticle dispersion is a critical issue in nanoparticle technology, their distribution and morphology have been extensively studied before and after electrospraying, and process optimization has been carried out to obtain nanoparticles uniformly spread over electrospun nanofibers. These membranes have been proved to be a good candidate for supported catalysis due to the photocatalytic activity of TiO2, tested for degradation of CEPS, a mustard agent simulant. At the same time, an effective improvement in filtering properties in terms of pressure drop has also been studied.

  12. Membrane-based recovery of glucose from enzymatic hydrolysis of ionic liquid pretreated cellulose.

    PubMed

    Abels, Christian; Thimm, Kristof; Wulfhorst, Helene; Spiess, Antje Christine; Wessling, Matthias

    2013-12-01

    In this work, a membrane-based downstream process for the recovery of glucose from cellulose hydrolysis is described and evaluated. The cellulose is pretreated with the ionic liquid 1,3-dimethyl-imidazolium dimethylphosphate to reduce its crystallinity. After enzymatic conversion of cellulose to glucose the hydrolysate is filtered with an ultrafiltration membrane to remove residual particulates and enzymes. Nanofiltration is applied to purify the glucose from molecular intermediates, such as cellobiose originating from the hydrolysis reaction. Finally, the ionic liquid is removed from the hydrolysate via electrodialysis. Technically, these process steps are feasible. An economic analysis of the process reveals that the selling price of glucose from this production process is about 2.75 €/kg which is too high as compared to the current market price.

  13. A membrane-based subsystem for very high recoveries of spacecraft waste waters

    NASA Technical Reports Server (NTRS)

    Ray, Roderick J.; Retzlaff, Sandra E.; Radke-Mitchell, Lyn; Newbold, David D.; Price, Donald F.

    1986-01-01

    This paper describes the continued development of a membrane-based subsystem designed to recover up to 99.5 percent of the water from various spacecraft waste waters. Specifically discussed are: (1) the design and fabrication of an energy-efficient reverse-osmosis (RO) breadboard subsystem; (2) data showing the performance of this subsystem when operated on a synthetic wash-water solution - including the results of a 92-day test; and (3) the results of pasteurization studies, including the design and operation of an in-line pasteurizer. Also included in this paper is a discussion of the design and performance of a second RO stage. This second stage results in higher-purity product water at a minimal energy requirement and provides a substantial redundancy factor to this subsystem.

  14. Continuous production of polymer nanoparticles using a membrane-based flow cell.

    PubMed

    Yang, Zhengnan; Foster, Dona; Dhinojwala, Ali

    2017-09-01

    We demonstrate the surfactant-free production of polymer nanoparticles using a continuous membrane-based tangential flow cell. Co-current streams of water and polymethylmethacrylate (PMMA)/acetone/water solution were separated by a porous regenerated cellulose (RC) membrane. The water concentration in the PMMA solution was adjusted so that as additional water diffused through the RC membrane, the PMMA solution composition crossed the two phase boundary to precipitate PMMA nanoparticles. The size of these nanoparticles varied with the concentration of the PMMA feed and the amount of water diffusing across the membrane. The size distribution of PMMA particles produced in a continuous flow membrane cell was much narrower than those produced by drop-wise water addition or batch dialysis precipitation of PMMA particles. A continuous production of polymer nanoparticles of high purity and narrow polydispersity are important requirements for biomedical applications such as delivering therapeutics. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Membrane-Based Emitter for Coupling Microfluidics with Ultrasensitive Nanoelectrospray Ionization-Mass Spectrometry

    SciTech Connect

    Sun, Xuefei; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

    2011-06-09

    An integrated poly(dimethylsiloxane) (PDMS) membrane-based microfluidic emitter for high performance nanoelectrospray ionization-mass spectrometry (nanoESI-MS) has been fabricated and evaluated. The ~100-μm-thick emitter was created by cutting a PDMS membrane that protrudes beyond the bulk substrate. The reduced surface area at the emitter enhances the electric field and reduces wetting of the surface by the electrospray solvent. As such, the emitter provides highly stable electrospray at flow rates as low as 10 nL/min, and is compatible with electrospray solvents containing a large organic component (e.g., 90% methanol). This approach enables facile emitter construction, and provides excellent stability, reproducibility and sensitivity, as well as compatibility with multilayer soft lithography.

  16. Membrane-based emitter for coupling microfluidics with ultrasensitive nanoelectrospray ionization-mass spectrometry.

    PubMed

    Sun, Xuefei; Kelly, Ryan T; Tang, Keqi; Smith, Richard D

    2011-07-15

    An integrated poly(dimethylsiloxane) (PDMS) membrane-based microfluidic emitter for high-performance nanoelectrospray ionization mass spectrometry has been fabricated and evaluated. The ∼100-μm-thick emitter was created by cutting a PDMS membrane that protrudes beyond the bulk substrate. The reduced surface area at the emitter enhances the electric field and reduces wetting of the surface by the electrospray solvent. As such, the emitter enables highly stable electrosprays at flow rates as low as 10 nL/min and is compatible with electrospray solvents containing a large organic component (e.g., 90% methanol). This approach enables facile emitter construction and provides excellent stability, reproducibility, and sensitivity as well as compatibility with multilayer soft lithography.

  17. A membrane-based subsystem for very high recoveries of spacecraft waste waters

    NASA Technical Reports Server (NTRS)

    Ray, Roderick J.; Retzlaff, Sandra E.; Radke-Mitchell, Lyn; Newbold, David D.; Price, Donald F.

    1986-01-01

    This paper describes the continued development of a membrane-based subsystem designed to recover up to 99.5 percent of the water from various spacecraft waste waters. Specifically discussed are: (1) the design and fabrication of an energy-efficient reverse-osmosis (RO) breadboard subsystem; (2) data showing the performance of this subsystem when operated on a synthetic wash-water solution - including the results of a 92-day test; and (3) the results of pasteurization studies, including the design and operation of an in-line pasteurizer. Also included in this paper is a discussion of the design and performance of a second RO stage. This second stage results in higher-purity product water at a minimal energy requirement and provides a substantial redundancy factor to this subsystem.

  18. Preparation, Characterization, and Analytical Application of Ramipril Membrane-Based Ion-Selective Electrode

    PubMed Central

    Arida, Hassan; Ahmed, Mona; Ali, Abdallah

    2009-01-01

    The fabrication and electrochemical evaluation of two PVC membrane-based Ion-Selective electrodes responsive for ramipril drug have been proposed. The sensitive membranes were prepared using ramipril-phosphomolibdate and ramipril-tetraphenylborate ion-pair complexes as electroactive sensing materials in plasticized PVC support. The electrodes based on these materials provide near-Nernestian response (sensitivity of 53 ± 0.5–54 ± 0.5 mV/concentration decade) covering the concentration range of 1.0 × 10−2–1.0 × 10−5 mol L−1 with a detection limit of 3.0 × 10−6–4.0 × 10−6 mol L−1. The suggested electrodes have been successfully used in the determination of ramipril drug in some pharmaceutical formulations using direct potentiometry with average recovery of >96% and mean standard deviation of <3% (n = 5). PMID:20140081

  19. MULTI-POLLUTANT CONTROL USING MEMBRANE--BASED UP-FLOW WET ELECTROSTATIC PRECIPITATION

    SciTech Connect

    James Reynolds

    2003-04-30

    This is the second quarterly report of the ''Multi-Pollutant Control Using Membrane-Based Upflow Wet Electrostatic Precipitation'' project funded by the US Department of Energy's National Energy Technology Laboratory under DOE Award No. DE-FC26-02NT41592 to Croll-Reynolds Clean Air Technologies (CRCAT). In this 18 month project, CRCAT and its team members will conduct detailed emission tests of metallic and new membrane collection material within a wet electrostatic precipitator (WESP) at First Energy's Penn Power's Bruce Mansfield (BMP) plant in Shippingport, Pa. Test results performed on the existing metallic WESP during November of 2002 showed consistent results with previous test results. Average collection efficiency of 89% on SO{sub 3} mist was achieved. Additionally, removal efficiencies of 62% were achieved at very high velocity, greater than 15 ft./sec. During the first quarter of 2003 final design and start of fabrication of the membrane wet ESP was undertaken.

  20. Microfabrication of membrane-based devices by deep-reactive ion etching (DRIE) of silicon

    SciTech Connect

    Manginell, R.P.; Frye-Mason, G.C.; Schubert, W.K.; Shul, R.J.; Willison, C.G.

    1998-08-01

    Deep reactive ion etching (DRIE) of silicon was utilized to fabricate dielectric membrane-based devices such as microhotplates, valves and flexural plate wave (FPW) devices. Through-wafer DRIE is characterized by fast etch rates ({approximately} 3 {micro}m/min), crystal orientation independence, vertical sidewall profiles and CMOS compatibility. Low-stress silicon nitride, a popular membrane material, has an appreciable DRIE etch rate. To overcome this limitations DRIE can be accompanied by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly lower etch rates on silicon nitride than does DRIE. The DRIE etch properties of composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.

  1. Green materials science and engineering reduces biofouling: approaches for medical and membrane-based technologies

    PubMed Central

    Dobosz, Kerianne M.; Kolewe, Kristopher W.; Schiffman, Jessica D.

    2015-01-01

    Numerous engineered and natural environments suffer deleterious effects from biofouling and/or biofilm formation. For instance, bacterial contamination on biomedical devices pose serious health concerns. In membrane-based technologies, such as desalination and wastewater reuse, biofouling decreases membrane lifetime, and increases the energy required to produce clean water. Traditionally, approaches have combatted bacteria using bactericidal agents. However, due to globalization, a decline in antibiotic discovery, and the widespread resistance of microbes to many commercial antibiotics and metallic nanoparticles, new materials, and approaches to reduce biofilm formation are needed. In this mini-review, we cover the recent strategies that have been explored to combat microbial contamination without exerting evolutionary pressure on microorganisms. Renewable feedstocks, relying on structure-property relationships, bioinspired/nature-derived compounds, and green processing methods are discussed. Greener strategies that mitigate biofouling hold great potential to positively impact human health and safety. PMID:25852659

  2. Modeling and Simulation of Membrane-Based Dehumidification and Energy Recovery Process

    SciTech Connect

    Gao, Zhiming; Abdelaziz, Omar; Qu, Ming

    2017-01-01

    This paper introduces a first-order physics-based model that accounts for the fundamental heat and mass transfer between a humid-air vapor stream on feed side to another flow stream on permeate side. The model comprises a few optional submodels for membrane mass transport; and it adopts a segment-by-segment method for discretizing heat and mass transfer governing equations for flow streams on feed and permeate sides. The model is able to simulate both dehumidifiers and energy recovery ventilators in parallel-flow, cross-flow, and counter-flow configurations. The predicted tresults are compared reasonably well with the measurements. The open-source codes are written in C++. The model and open-source codes are expected to become a fundament tool for the analysis of membrane-based dehumidification in the future.

  3. Analysis of a membrane-based condesate recovery heat exchanger (CRX)

    NASA Technical Reports Server (NTRS)

    Newbold, D.D.

    1993-01-01

    The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from air, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat exchanger known as the condensate recovery heat exchanger (CRX). This device cools and dehumidifies humid air and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and mass-transfer characteristics of the device are given.

  4. Green materials science and engineering reduces biofouling: approaches for medical and membrane-based technologies.

    PubMed

    Dobosz, Kerianne M; Kolewe, Kristopher W; Schiffman, Jessica D

    2015-01-01

    Numerous engineered and natural environments suffer deleterious effects from biofouling and/or biofilm formation. For instance, bacterial contamination on biomedical devices pose serious health concerns. In membrane-based technologies, such as desalination and wastewater reuse, biofouling decreases membrane lifetime, and increases the energy required to produce clean water. Traditionally, approaches have combatted bacteria using bactericidal agents. However, due to globalization, a decline in antibiotic discovery, and the widespread resistance of microbes to many commercial antibiotics and metallic nanoparticles, new materials, and approaches to reduce biofilm formation are needed. In this mini-review, we cover the recent strategies that have been explored to combat microbial contamination without exerting evolutionary pressure on microorganisms. Renewable feedstocks, relying on structure-property relationships, bioinspired/nature-derived compounds, and green processing methods are discussed. Greener strategies that mitigate biofouling hold great potential to positively impact human health and safety.

  5. MULTI-POLLUTANT CONTROL USING MEMBRANE-BASED UP-FLOW WET ELECTROSTATIC PRECIPITATION

    SciTech Connect

    James Reynolds

    2003-01-01

    This is the first quarterly report of the ''Multi-Pollutant Control Using Membrane--Based Upflow Wet Electrostatic Precipitation'' project funded by the US Department of Energy's National Energy Technology Laboratory under DOE Award No. DE-FC26-02NT41592 to Croll-Reynolds Clean Air Technologies (CRCAT). In this 18 month project, CRCAT and its team members will conduct detailed emission tests of metallic and new membrane collection material within a wet electrostatic precipitator (WESP) at First Energy's Penn Power's Bruce Mansfield (BMP) plant in Shippingport, Pa. Test results performed on the existing metallic WESP during November of 2002 showed consistent results with previous test results. Average collection efficiency of 89% on SO{sub 3} mist was achieved. Additionally, removal efficiencies of 62% were achieved at very high velocity, greater than 15 ft./sec.

  6. Millimeter thick ionic polymer membrane-based IPMCs with bimetallic Pd-Pt electrodes

    NASA Astrophysics Data System (ADS)

    Palmre, Viljar; Kim, Sung Jun; Kim, Kwang

    2011-04-01

    Ionic polymer metal composites (IPMC) are a low-voltage driven Electroactive Polymers (EAP) that can be used as actuators or sensors. This paper presents a comparative study of millimeter thick ionic polymer membrane-based IPMCs with high-performance Pd-Pt electrodes and conventional Pt electrodes. IPMCs assembled with different electrodes are characterized in terms of electromechanical, -chemical and mechanolelectrical properties. The SEM and energy dispersive X-ray (EDS) analysis are used to investigate the distribution of deposited electrode metals in the cross-section of Pd-Pt IPMCs. The study shows that IPMCs assembled with millimeter thick ionic polymer membranes and bimetallic Pd-Pt electrodes are superior in mechanoelectrical sensing and, also, show considerably higher blocking forces compared to the conventional type of IPMCs. Blocking forces more than 30 grams are measured under 4V DC. However, the actuation response is slower than conventional IPMCs having approximately 0.2-0.3 mm thickness.

  7. Development of Membrane-Based Desiccant Fiber for Vacuum Desiccant Cooling.

    PubMed

    Yang, Yifan; Rana, Dipak; Lan, Christopher Q; Matsuura, Takeshi

    2016-06-22

    A novel hydrophobic membrane-based desiccant fiber (MDF) was developed by loading lithium chloride into hydrophobic hollow fiber membranes. The MDF thus made was then tested for vapor absorption under controlled conditions. Furthermore, an MDF pad, which was made by weaving MDF into a piece of garment, was built into a laboratory vacuum desiccant cooling (VDC) setup, which included the MDF pad as the desiccant layer and a cooling towel saturated with water as the water reservoir, to test the cooling effects at atmospheric pressure and vacuum of 25 in. of Hg. Results indicate that MDF is suitable for applications such as in VDC. Mass and heat transfer of vapor absorption by MDF were also analyzed.

  8. Ultrasensitive cDNA Detection of Dengue Virus RNA Using Electrochemical Nanoporous Membrane-Based Biosensor

    PubMed Central

    Rai, Varun; Hapuarachchi, Hapuarachchige C.; Ng, Lee Ching; Soh, Siew Hwa; Leo, Yee Sin; Toh, Chee-Seng

    2012-01-01

    A nanoporous alumina membrane-based ultrasensitive DNA biosensor is constructed using 5′-aminated DNA probes immobilized onto the alumina channel walls. Alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 µm diameter dimension by electrochemical anodization. The hybridization of complementary target DNA with probe DNA molecules attached inside the pores influences the pore size and ionic conductivity. The biosensor demonstrates linear range over 6 order of magnitude with ultrasensitive detection limit of 9.55×10−12 M for the quantification of ss-31 mer DNA sequence. Its applicability is challenged against real time cDNA PCR sample of dengue virus serotype1 derived from asymmetric PCR. Excellent specificity down to one nucleotide mismatch in target DNA sample of DENV3 is also demonstrated. PMID:22927927

  9. Membrane-based cell culture systems--an alternative to in vivo production of monoclonal antibodies.

    PubMed

    Nagel, A; Koch, S; Valley, U; Emmrich, F; Marx, U

    1999-01-01

    A new generation of membrane-based cell culture devices especially designed for small scale production of monoclonal antibodies (mabs) has entered the market in the last few years. In contrast to conventional perfusion hollow fibre bioreactors, these devices contain two functionally different membranes--one ultrafiltration membrane for nutrient supply and one gas-permeable membrane for direct oxygenation of cells. The latest systems of this generation are static culture systems which are of moderate cost and either better than, or equal to, the ascites mice in terms of quality and quantity of produced monoclonal antibodies. We have investigated the advantages of the perfused Tecnomouse bioreactor and the static CELLine culture flasks in comparison to ascites production and conventional roller bottle cultures.

  10. Reduction of VOC emissions by a membrane-based gas absorption process.

    PubMed

    Li, Rui; Xu, Jun; Wang, Lianjun; Li, Jiansheng; Sun, Xiuyun

    2009-01-01

    A membrane-based gas absorption (MGA) process was evaluated for the removal of volatile organic compounds (VOCs) based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine (NFM) as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.

  11. Analysis of a membrane-based condesate recovery heat exchanger (CRX)

    NASA Technical Reports Server (NTRS)

    Newbold, D.D.

    1993-01-01

    The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from air, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat exchanger known as the condensate recovery heat exchanger (CRX). This device cools and dehumidifies humid air and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and mass-transfer characteristics of the device are given.

  12. Angiogenesis mediated by soluble forms of E-selectin and vascular cell adhesion molecule-1

    NASA Astrophysics Data System (ADS)

    Koch, Alisa E.; Halloran, Margaret M.; Haskell, Catherine J.; Shah, Manisha R.; Polverini, Peter J.

    1995-08-01

    ENDOTHELIAL adhesion molecules facilitate the entry of leukocytes into inflamed tissues. This in turn promotes neovascularization, a process central to the progression of rheumatoid arthritis, tumour growth and wound repair1. Here we test the hypothesis that soluble endothelial adhesion molecules promote angiogenesis2á¤-4. Human recombinant soluble E-selectin and soluble vascular cell adhesion molecule-1 induced chemotaxis of human endothelial cells in vitro and were angiogenic in rat cornea. Soluble E-selectin acted on endothelial cells in part through a sialyl Lewis-X-dependent mechanism, while soluble vascular cell adhesion molecule-1 acted on endothelial cells in part through a very late antigen (VLA)-4 dependent mechanism. The chemotactic activity of rheumatoid synovial fluid for endothelial cells, and also its angiogenic activity, were blocked by antibodies to either soluble E-selectin or soluble vascular cell adhesion molecule-1. These results suggest a novel function for soluble endothelial adhesion molecules as mediators of angiogenesis.

  13. Measurement and Accurate Interpretation of the Solubility of Pharmaceutical Salts.

    PubMed

    He, Yan; Ho, Chris; Yang, Donglai; Chen, Jeane; Orton, Edward

    2017-01-30

    Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts.

  14. Solubility enhancement of rosiglitazone by using melt sonocrystallization technique.

    PubMed

    Jagtap, Vaibhavkumar A; Vidyasagar, G; Dvivedi, S C

    2014-03-01

    The poor solubility and low dissolution rate in gastro-intestinal fluid, especially for class-II drugs according to Biopharmaceutics Classification System (BCS) the bioavailability enhanced by increasing the solubility and dissolution rate. A novel melt sonocrystallization technique of particle engineering to enhance solubility as well as dissolution of hydrophobic drug and to study its effect on crystal properties of drug. The present study leads to use investigate solubility of melt sonocrystallization technique to modify the undesirable properties of Rosiglitazone is antidiabetic drug in thiozolidione category with (BCS II) to forms agglomerates with number of shallow circular pits on the surface leads to increase solubility. Melt sonocrystallization process was developed for Rosiglitazone in which Rosiglitazone melt was poured in deionized water and simultaneously subjected to ultrasonic energy for 20 min at amplitude 80 %. The product obtained was evaluated using scanning electron microscopy, differential scanning calorimetry, X-ray powder diffractometry (XPRD), Fourier transformed infrared spectroscopy (FTIR), solubility and dissolution rate. The irregular agglomerates with porous surface were obtained having different crystal habit which increases solubility and dissolution rate. FTIR shows thermal behavior of untreated Rosiglitazone and treated Rosiglitazone have no significant difference low intensity peaks in XPRD of treated Rosiglitazone were noticed crystals habit changes and lattice defects during processing have causes favorable changes in the physicochemical properties of Rosiglitazone. The use of melt sonocrystallization technique is promising technique that may affords powder with improved flow as well as improved solubility and dissolution.

  15. Formulation of soluble oils with synthetic and petroleum sulfonates

    SciTech Connect

    Eckard, A.; Riff, I.; Weaver, J.

    1997-06-01

    Metalworking fluids for metal removal are formulated to provide cooling, lubrication, and rust protection when cutting and machining metals. There are basically four types of cutting fluids: straight oils, synthetics, semisynthetic fluids and soluble oils. The last type is the most widely used for metal removal operations such as cutting, drilling and grinding. Soluble oils used for metalworking operations are normally the oil-in-water type, with oil as the internal phase and water as the external phase. The soluble oils can have rather complex compositions, usually containing two or more emulsifiers and coupling agents, as well as additives to provide rust inhibition, lubricity, detergency, resistance to bacterial attack and foam control. The dominant emulsifier in a soluble oil is usually sodium sulfonate which also has the secondary benefit of being a rust inhibitor. Soluble oil emulsions based on petroleum or synthetic sulfonates have been found to improve lubrication and cleaning of metal parts and equipment. As has been done previously, a series of emulsification studies were conducted using petroleum and synthetic sulfonates. Emulsifier level, coemulsifiers and minor formulation adjustments were made to optimize each system. This study was made using naphthenic oil basestock. Formulations were evaluated using criteria including concentrate stability, hard and soft water emulsion stability, emulsibility, foaming tendency and response to defoamers, antirust properties and cost effectiveness of individual formulations. The results of these evaluations are presented in the present paper.

  16. Fluid Physics

    NASA Image and Video Library

    2002-12-12

    These are video microscope images of magnetorheological (MR) fluids, illuminated with a green light. Those on Earth, left, show the MR fluid forming columns or spikes structures. On the right, the fluids in microgravity aboard the International Space Station (ISS), formed broader columns.

  17. Fluid Mechanics.

    ERIC Educational Resources Information Center

    Drazin, Philip

    1987-01-01

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

  18. Fluid Mechanics.

    ERIC Educational Resources Information Center

    Drazin, Philip

    1987-01-01

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

  19. A Perspective on Solubility Rules.

    ERIC Educational Resources Information Center

    Monroe, Manus; Abrams, Karl

    1984-01-01

    Presents four generalizations about solubilities. These generalizations (rules), are useful in introducing the dynamic topics of solubility and in helping high school and introductory college chemistry students make some order out of the tremendous number of facts available. (JN)

  20. Soluble and insoluble fiber (image)

    MedlinePlus

    Dietary fiber is the part of food that is not affected by the digestive process in the body. ... of the stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and ...

  1. A Perspective on Solubility Rules.

    ERIC Educational Resources Information Center

    Monroe, Manus; Abrams, Karl

    1984-01-01

    Presents four generalizations about solubilities. These generalizations (rules), are useful in introducing the dynamic topics of solubility and in helping high school and introductory college chemistry students make some order out of the tremendous number of facts available. (JN)

  2. Supersaturation in human gastric fluids.

    PubMed

    Bevernage, Jan; Hens, Bart; Brouwers, Joachim; Tack, Jan; Annaert, Pieter; Augustijns, Patrick

    2012-05-01

    The current study reports on supersaturation, precipitation and excipient mediated precipitation inhibition of five poorly soluble drugs (loviride, glibenclamide, itraconazole, danazol, and etravirine) in human and simulated gastric fluids. Upon induction of supersaturation in human gastric fluids (HGFs), simulated gastric fluid (SGF), and fasted state simulated gastric fluid (FaSSGF) using a solvent shift method, supersaturation and precipitation were assessed as a function of time. In addition, the precipitation inhibitory capacity of three polymers (Eudragit® E PO, HPMC-E5, and PVP K25) was investigated. Supersaturation in human gastric fluids was observed for all model compounds, but proved to be relatively unstable (fast precipitation), except for itraconazole. Only modest excipient-mediated stabilizing effects on supersaturation were observed using HPMC-E5 and Eudragit® E PO whereas PVP K25 exerted no effect. In contrast to SGF, the observed precipitation behavior in FaSSGF was similar to the behavior in human gastric fluids. The present study demonstrates that supersaturation stability of drugs in human gastric fluids is in general inferior to supersaturation stability in intestinal fluids. As the potential for excipient mediated precipitation inhibition in gastric fluids was only limited, our data suggest that supersaturation should preferably be targeted to the intestine. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Viscous fingering with partial miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2015-11-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Studies of viscous fingering have focused on fluids that are either fully miscible or perfectly immiscible. In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other. Following our recent work for miscible (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a Hele-Shaw cell, when the two fluids have limited (but nonzero) solubility in one another. Partial miscibility is characterized through the design of thermodynamic free energy of the two-fluid system. We elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution.

  4. Anhydrite solubility in differentiated arc magmas

    NASA Astrophysics Data System (ADS)

    Masotta, M.; Keppler, H.

    2015-06-01

    The solubility of anhydrite in differentiated arc magmas was experimentally studied at 200 MPa and 800-1000 °C over a range of oxygen fugacities, from 0.5 log units above the Ni-NiO buffer to the hematite-magnetite buffer. Anhydrite is stable only at oxidizing conditions (fO2 ⩾ Re-ReO2), whereas sulfides only form under reducing conditions. The solubility of anhydrite in the melt ultimately regulates the amount of sulfur available to partition between melt and fluid phase during the eruption. At oxidizing conditions, the solubility product of anhydrite increases with temperature, nbo/t and melt water content. We provide a new calibration of the anhydrite solubility product (KSP = XCaO * XSO3), which reproduces all available experimental data with greatly improved accuracy: In this equation, the molar fractions XCaO and XSO3 in the melt as well as the number of non-bridging oxygen atoms per tetrahedron (nbo/t) are calculated on an anhydrous basis (H2O refers to the melt water content, T is temperature in Kelvin). We apply our model to estimate the sulfur yield of some recent volcanic eruptions and we show that the sulfur yield of the 1991 Mt. Pinatubo dacite eruption was unusually large, because only a small fraction of the sulfur was locked up in anhydrite. In general, high sulfur yields are expected when anhydrite solubility in the melt is high, i.e. for somewhat depolymerized melts. For rhyolitic systems, most of the available sulfur will be locked up in anhydrite, so that even very large eruptions may only have a small effect on global surface temperatures. Our model therefore allows improved predictions of the environmental impact of explosive volcanic eruptions.

  5. Electrorheological fluids

    SciTech Connect

    Adolf, D.; Anderson, R.; Garino, T.; Halsey, T.C.; Hance, B.; Martin, J.E.; Odinek, J.

    1996-10-01

    An Electrorheological fluid is normally a low-viscosity colloidal suspension, but when an electric field is applied, the fluid undergoes a reversible transition to a solid, being able to support considerable stress without yield. Commercial possibilities for such fluids are enormous, including clutches, brakes, valves,shock absorbers, and stepper motors. However, performance of current fluids is inadequate for many proposed applications. Our goal was to engineer improved fluids by investigating the key technical issues underlying the solid-phase yield stress and the liquid to solid switching time. Our studies focused on field-induced interactions between colloidal particles that lead to solidification, the relation between fluid structure and performance (viscosity, yield stress), and the time evolution of structure in the fluid as the field is switched on or off.

  6. An Investigation of Dental Luting Cement Solubility as a Function of the Marginal Gap.

    DTIC Science & Technology

    1988-05-01

    be non-irritating to the dental pulp , and have low solubility. A critical property of luting cement is its solubility in oral fluids. If the cement...25 micron and 100 micron cement margins. In another investigation, hollow orthodontic tubing and the acid etch composite resin technique were used to...evaluate cement solubility. (lbbetson 1985) Hollow orthodontic tubing, with a 0.05 mm diameter, was filled with dental cement and attached to the

  7. Comparison of biorelevant simulated media mimicking the intestinal environment to assess the solubility profiles of poorly soluble drugs.

    PubMed

    Prasad, Dev; Gu, Chong-Hui; Kuldipkumar, Anuj

    2016-01-01

    During the discovery stage in lead identification/optimization, compounds are characterized for their solubilities in biorelevant media and these data are often used to model the in vivo behavior of the compounds and predict the fraction absorbed. These media are selected to closely approximate the composition of human intestinal fluid. Owing to the complexity and variability in human intestinal fluid composition, it is essential that the chosen simulated media mimic the in vivo condition as closely as possible. Several recipes have been developed and are routinely used in assessing the solubilities of compounds. It is necessary to revisit these recipes and modify them as the understanding of the human GI tract increases. In the present work, we have evaluated the solubilities of six model compounds in several media and have proposed slight modifications to the currently used recipes based on our own data and that reported in the literature.

  8. IMMUNOLOGICAL REACTIONS OF PNEUMONIC PLEURAL FLUIDS

    PubMed Central

    Finland, Maxwell

    1932-01-01

    Pleuritic exudates from patients with lobar pneumonia may be sterile or infected. Sterile fluids, at or about the time of crisis, contain actively acquired antibodies similar to those in the blood serum. Infected fluids do not contain such antibodies, presumably because of the presence in them of large amounts of soluble specific substance. Sterile fluids from patients treated with immune sera have both horse serum and antibodies similar to those injected. Infected fluids from serum-treated cases contain horse serum and such heterologous antibodies as were contained in the therapeutic sera together with homologous soluble specific substance. The concentration of horse serum and antibodies in pneumonic fluids is usually the same or somewhat less than that of the corresponding blood sera. PMID:19869983

  9. Solubility and dissolution profile assessment in drug discovery.

    PubMed

    Sugano, Kiyohiko; Okazaki, Arimichi; Sugimoto, Shohei; Tavornvipas, Sumitra; Omura, Atsushi; Mano, Takashi

    2007-08-01

    The purposes of the review are to: a) Provide a comprehensible introduction of the-state-of-the-art sciences of solubility and dissolution, b) introduce typical technologies to assess solubility and dissolution, and c) propose the best practice strategy. The theories of solubility and dissolution required in drug discovery were reviewed especially from the view point of oral absorption. The physiological conditions in the gastrointestinal fluid in humans and animals were then briefly summarized. Technologies to assess solubility and dissolution in drug discovery were then introduced. Recently, these technologies have been improved by the laboratory automation and computational technologies. Finally, the strategies to apply these technologies for a drug discovery project were discussed.

  10. Bioconcentration factors and lipid solubility

    SciTech Connect

    Banerjee, S. ); Baughman, G.L. )

    1991-03-01

    The log-log relationship between bioconcentration and hydrophobicity breaks down for several medium and high molecular weight solutes that bioconcentrate either to a small extent or not at all. Much of the failure is attributed to the relatively low solubility of these compounds in lipid. Inclusion of a term in octanol solubility (in place of lipid solubility, which is generally unavailable) considerably improves the quality of the relationship (r = 0.95). It is speculated that the octanol solubility term compensates for the relatively low solubility of large compounds in lipid.

  11. Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment

    ERIC Educational Resources Information Center

    Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

    2012-01-01

    A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

  12. Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment

    ERIC Educational Resources Information Center

    Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

    2012-01-01

    A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

  13. Soluble porphyrin polymers

    DOEpatents

    Gust, Jr., John Devens; Liddell, Paul Anthony

    2015-07-07

    Porphyrin polymers of Structure 1, where n is an integer (e.g., 1, 2, 3, 4, 5, or greater) ##STR00001## are synthesized by the method shown in FIGS. 2A and 2B. The porphyrin polymers of Structure 1 are soluble in organic solvents such as 2-MeTHF and the like, and can be synthesized in bulk (i.e., in processes other than electropolymerization). These porphyrin polymers have long excited state lifetimes, making the material suitable as an organic semiconductor for organic electronic devices including transistors and memories, as well as solar cells, sensors, light-emitting devices, and other opto-electronic devices.

  14. IUPAC-NIST Solubility Data Series 70. The Solubility of Gases in Glassy Polymers

    NASA Astrophysics Data System (ADS)

    Paterson, Russell; Yampol'Skii, Yuri P.; Fogg, Peter G. T.; Bokarev, Alexandre; Bondar, Valerii; Ilinich, Oleg; Shishatskii, Sergey

    1999-09-01

    Solubility of gases in polymers is an important property of polymeric materials relevant to many practical applications. Sorption of small molecules in polymers is a fundamental concern in such areas as food packaging, beverage storage, and polymer processing. However, by far the main interest in the solubility of gases in polymers, and especially in glassy polymers, is related to development of novel advanced materials for gas separation membranes. This is because the concentration gradient of a dissolved gas is the driving force of membrane processes. Development of these novel separation methods resulted in a rapid accumulation, in the recent literature, of thermodynamic data related to the solubility of gases in polymers at different temperatures and pressures. Polymers can be regarded as special cases of media intermediate between liquids and solids. As a consequence, modeling of gas sorption in polymers is very difficult and presents a permanent challenge to theoreticians and experimenters. The collection and critical evaluation of solubility data for various gas-polymer systems is relevant to both practical aspects of polymer applications and to fundamental studies of polymer behavior. This volume of the IUPAC-NIST Solubility Data Series summarizes the compilations and critical evaluations of the data on solubility of gases in glassy polymers. It is implied in this edition that "gases" are the components that are either permanent gases (supercitical fluids) or have saturated vapor pressure more than 1 atm at ambient conditions (298 K). The polymeric components of compilations and critical evaluations are primarily high molecular mass, amorphous, linear (noncross-linked) compounds that have the glass transition temperatures above ambient temperature. The data for each gas-polymer system have been evaluated, if the results of at least three independent and reliable studies have been reported. Where the data of sufficient accuracy and reliability are available

  15. Parallel detection of harmful algae using reverse transcription polymerase chain reaction labeling coupled with membrane-based DNA array.

    PubMed

    Zhang, Chunyun; Chen, Guofu; Ma, Chaoshuai; Wang, Yuanyuan; Zhang, Baoyu; Wang, Guangce

    2014-03-01

    Harmful algal blooms (HABs) are a global problem, which can cause economic loss to aquaculture industry's and pose a potential threat to human health. More attention must be made on the development of effective detection methods for the causative microalgae. The traditional microscopic examination has many disadvantages, such as low efficiency, inaccuracy, and requires specialized skill in identification and especially is incompetent for parallel analysis of several morphologically similar microalgae to species level at one time. This study aimed at exploring the feasibility of using membrane-based DNA array for parallel detection of several microalgae by selecting five microaglae, including Heterosigma akashiwo, Chaetoceros debilis, Skeletonema costatum, Prorocentrum donghaiense, and Nitzschia closterium as test species. Five species-specific (taxonomic) probes were designed from variable regions of the large subunit ribosomal DNA (LSU rDNA) by visualizing the alignment of LSU rDNA of related species. The specificity of the probes was confirmed by dot blot hybridization. The membrane-based DNA array was prepared by spotting the tailed taxonomic probes onto positively charged nylon membrane. Digoxigenin (Dig) labeling of target molecules was performed by multiple PCR/RT-PCR using RNA/DNA mixture of five microalgae as template. The Dig-labeled amplification products were hybridized with the membrane-based DNA array to produce visible hybridization signal indicating the presence of target algae. Detection sensitivity comparison showed that RT-PCR labeling (RPL) coupled with hybridization was tenfold more sensitive than DNA-PCR-labeling-coupled with hybridization. Finally, the effectiveness of RPL coupled with membrane-based DNA array was validated by testing with simulated and natural water samples, respectively. All of these results indicated that RPL coupled with membrane-based DNA array is specific, simple, and sensitive for parallel detection of microalgae which

  16. Flow-through membrane-based enzyme immunoassay for rapid detection of ochratoxin A in wheat.

    PubMed

    De Saeger, S; Van Peteghem, C

    1999-01-01

    A flow-through membrane-based enzyme immunoassay for the rapid detection of ochratoxin A in wheat was developed (patent pending). An Immunodyne ABC membrane was coated with rabbit anti-mouse immunoglobulins and free protein binding sites were blocked. After these antibody-coated membranes were placed on an absorbent layer in a plastic test device, a sequential competitive enzyme immunoassay was performed. The following reactants were successively dropped onto the membrane: wash solution, a dilution of monoclonal anti-ochratoxin A immunoglobulins, wash solution, ochratoxin A standard solution or sample extract solution, a dilution of ochratoxin A-horseradish peroxidase conjugate, and wash solution. Finally, substrate solution (H2O2-3,3',5,5'-tetramethylbenzidine) was added for color reaction. The dot color intensity on the membrane was visually compared with that of the negative control, which showed the most intense blue color because of the inverse relationship between toxin concentration and color development. A portable colorimeter was used to confirm and quantify the visual observations. An ochratoxin A concentration of 0.4 ng/ml in buffer solution suppressed the color development completely. With the use of a simple sample preparation procedure it was possible to eliminate matrix interference. A wheat sample spiked with 4 microg/kg resulted in a complete color suppression. With coated membranes, the immunoassay could be performed in less than 15 min.

  17. Promising aquivion composite membranes based on fluoroalkyl zirconium phosphate for fuel cell applications.

    PubMed

    Donnadio, Anna; Pica, Monica; Subianto, Surya; Jones, Deborah J; Cojocaru, Paula; Casciola, Mario

    2014-08-01

    Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short-side-chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt% show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY ) are observed for the 10 wt% ZPR membrane: ΔE/E up to 90% and ΔσY /σY up 70% at 70°C and 80% relative humidity (RH). In the RH range 50-95%, the in-plane conductivity of the composite membranes reaches 0.43 S cm(-1) for 10 wt% ZPR at 110°C and is on average 30% higher than the conductivity of the pristine PFSA. The 10 wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50% RH but becomes progressively less hydrated with increasing RH both at 80 and 110°C. The fuel cell performance of this membrane, at 80°C and 30% RH, is better than that of the unmodified PFSA.

  18. Approach for Self-Calibrating CO2 Measurements with Linear Membrane-Based Gas Sensors

    PubMed Central

    Lazik, Detlef; Sood, Pramit

    2016-01-01

    Linear membrane-based gas sensors that can be advantageously applied for the measurement of a single gas component in large heterogeneous systems, e.g., for representative determination of CO2 in the subsurface, can be designed depending on the properties of the observation object. A resulting disadvantage is that the permeation-based sensor response depends on operating conditions, the individual site-adapted sensor geometry, the membrane material, and the target gas component. Therefore, calibration is needed, especially of the slope, which could change over several orders of magnitude. A calibration-free approach based on an internal gas standard is developed to overcome the multi-criterial slope dependency. This results in a normalization of sensor response and enables the sensor to assess the significance of measurement. The approach was proofed on the example of CO2 analysis in dry air with tubular PDMS membranes for various CO2 concentrations of an internal standard. Negligible temperature dependency was found within an 18 K range. The transformation behavior of the measurement signal and the influence of concentration variations of the internal standard on the measurement signal were shown. Offsets that were adjusted based on the stated theory for the given measurement conditions and material data from the literature were in agreement with the experimentally determined offsets. A measurement comparison with an NDIR reference sensor shows an unexpectedly low bias (<1%) of the non-calibrated sensor response, and comparable statistical uncertainty. PMID:27869656

  19. MULTI-POLLUTANT CONTROL USING MEMBRANE--BASED UP-FLOW WET ELECTROSTATIC PRECIPITATION

    SciTech Connect

    James Reynolds

    2004-10-29

    This is the Final Report of the ''Multi-Pollutant Control Using Membrane-Based Up-flow Wet Electrostatic Precipitation'' project funded by the US Department of Energy's National Energy Technology Laboratory under DOE Award No. DE-FC26-02NT41592 to Croll-Reynolds Clean Air Technologies (CRCAT). In this 18 month project, CRCAT and its team members conducted detailed emission tests of metallic and new membrane collection material within a wet electrostatic precipitator (WESP) at First Energy's Penn Power's Bruce Mansfield (BMP) plant in Shippingport, Pa. The Membrane WESP was designed to be as similar as the metallic WESP in terms of collection area, air-flow, and electrical characteristics. Both units are two-field units. The membrane unit was installed during the 2nd and 3rd quarters of 2003. Testing of the metallic unit was performed to create a baseline since the Mansfield plant had installed selective catalytic reduction equipment for NOx control and a sodium bisulfate injection system for SO3 control during the spring of 2003. Tests results on the metallic WESP were consistent with previous testing for PM2.5, SO3 mist and mercury. Testing on the membrane WESP demonstrated no adverse impact and equivalent removal efficiencies as that of the metallic WESP. Testing on both units was performed at 8,000 acfm and 15,000 acfm. Summary results are shown.

  20. Microfabrication of membrane-based devices by HARSE and combined HARSE/wet etching

    SciTech Connect

    Manginell, R.P.; Frye-Mason, G.C.; Schubert, W.K.; Shul, R.J.; Willison, C.G.

    1998-08-01

    Deep-reactive ion etching (DRIE) of silicon, also known as high-aspect-ratio silicon etching (HARSE), is distinguished by fast etch rates ({approximately}3 {micro}m/min), crystal orientation independence, anisotropy, vertical sidewall profiles and CMOS compatibility. By using through-wafer HARSE and stopping on a dielectric film placed on the opposite side of the wafer, freestanding dielectric membranes were produced. Dielectric membrane-based sensors and actuators fabricated in this way include microhotplates, flow sensors, valves and magnetically-actuated flexural plate wave (FPW) devices. Unfortunately, low-stress silicon nitride, a common membrane material, has an appreciable DRI etch rate. To overcome this problem HARSE can be followed by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly smaller etch rates on silicon nitride than does DRIE. Composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.

  1. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    SciTech Connect

    Kim, Dae Sik; Kim, Yu Seung; Lee, Kwan - Soo; Boncella, James M; Kuiper, David; Guiver, Michael D

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  2. Modelling heat and mass transfer in a membrane-based air-to-air enthalpy exchanger

    NASA Astrophysics Data System (ADS)

    Dugaria, S.; Moro, L.; Del, D., Col

    2015-11-01

    The diffusion of total energy recovery systems could lead to a significant reduction in the energy demand for building air-conditioning. With these devices, sensible heat and humidity can be recovered in winter from the exhaust airstream, while, in summer, the incoming air stream can be cooled and dehumidified by transferring the excess heat and moisture to the exhaust air stream. Membrane based enthalpy exchangers are composed by different channels separated by semi-permeable membranes. The membrane allows moisture transfer under vapour pressure difference, or water concentration difference, between the two sides and, at the same time, it is ideally impermeable to air and other contaminants present in exhaust air. Heat transfer between the airstreams occurs through the membrane due to the temperature gradient. The aim of this work is to develop a detailed model of the coupled heat and mass transfer mechanisms through the membrane between the two airstreams. After a review of the most relevant models published in the scientific literature, the governing equations are presented and some simplifying assumptions are analysed and discussed. As a result, a steady-state, two-dimensional finite difference numerical model is setup. The developed model is able to predict temperature and humidity evolution inside the channels. Sensible and latent heat transfer rate, as well as moisture transfer rate, are determined. A sensitive analysis is conducted in order to determine the more influential parameters on the thermal and vapour transfer.

  3. Approach for Self-Calibrating CO₂ Measurements with Linear Membrane-Based Gas Sensors.

    PubMed

    Lazik, Detlef; Sood, Pramit

    2016-11-17

    Linear membrane-based gas sensors that can be advantageously applied for the measurement of a single gas component in large heterogeneous systems, e.g., for representative determination of CO₂ in the subsurface, can be designed depending on the properties of the observation object. A resulting disadvantage is that the permeation-based sensor response depends on operating conditions, the individual site-adapted sensor geometry, the membrane material, and the target gas component. Therefore, calibration is needed, especially of the slope, which could change over several orders of magnitude. A calibration-free approach based on an internal gas standard is developed to overcome the multi-criterial slope dependency. This results in a normalization of sensor response and enables the sensor to assess the significance of measurement. The approach was proofed on the example of CO₂ analysis in dry air with tubular PDMS membranes for various CO₂ concentrations of an internal standard. Negligible temperature dependency was found within an 18 K range. The transformation behavior of the measurement signal and the influence of concentration variations of the internal standard on the measurement signal were shown. Offsets that were adjusted based on the stated theory for the given measurement conditions and material data from the literature were in agreement with the experimentally determined offsets. A measurement comparison with an NDIR reference sensor shows an unexpectedly low bias (<1%) of the non-calibrated sensor response, and comparable statistical uncertainty.

  4. Integration of an interferometric IR absorber into an epoxy membrane based CO2 detector

    NASA Astrophysics Data System (ADS)

    Ashraf, S.; Mattsson, C. G.; Thungström, G.; Rödjegård, H.

    2014-05-01

    Measurements of carbon dioxide levels in the environment are commonly performed by using non-dispersive infrared technology (NDIR). Thermopile detectors are often used in NDIR systems because of their non-cooling advantages. The infrared absorber has a major influence on the detector responsivity. In this paper, the fabrication of a SU-8 epoxy membrane based Al/Bi thermopile detector and the integration of an interferometric infrared absorber structure of wavelength around 4 μm into the detector is reported. The membrane of thermopile detector has been utilized as a dielectric medium in an interferometric absorption structure. By doing so, a reduction in both thermal conductance and capacitance is achieved. In the fabrication of the thermopile, metal evaporation and lift off process had been used for the deposition of serially interconnected Al/Bi thermocouples. Serial resistance of fabricated thermopile was measured as 220 kΩ. The response of fabricated thermopile detector was measured using a visible to infrared source of radiation flux 3.23 mW mm-2. The radiation incident on the detector was limited using a band pass filter of wavelength 4.26 μm in front of the detector. A responsivity of 27.86 V mm2 W-1 at room temperature was achieved using this setup. The fabricated detector was compared to a reference detector with a broad band absorber. From the comparison it was concluded that the integrated interferometric absorber is functioning correctly.

  5. Novel Membrane-Based Electrochemical Sensor for Real-Time Bio-Applications

    PubMed Central

    Alatraktchi, Fatima AlZahra'a; Bakmand, Tanya; Dimaki, Maria; Svendsen, Winnie E.

    2014-01-01

    This article presents a novel membrane-based sensor for real-time electrochemical investigations of cellular- or tissue cultures. The membrane sensor enables recording of electrical signals from a cell culture without any signal dilution, thus avoiding loss of sensitivity. Moreover, the porosity of the membrane provides optimal culturing conditions similar to existing culturing techniques allowing more efficient nutrient uptake and molecule release. The patterned sensor electrodes were fabricated on a porous membrane by electron-beam evaporation. The electrochemical performance of the membrane electrodes was characterized by cyclic voltammetry and chronoamperometry, and the detection of synthetic dopamine was demonstrated down to a concentration of 3.1 pM. Furthermore, to present the membrane-sensor functionality the dopamine release from cultured PC12 cells was successfully measured. The PC12 cells culturing experiments showed that the membrane-sensor was suitable as a cell culturing substrate for bio-applications. Real-time measurements of dopamine exocytosis in cell cultures were performed, where the transmitter release was recorded at the point of release. The developed membrane-sensor provides a new functionality to the standard culturing methods, enabling sensitive continuous in vitro monitoring and closely mimicking the in vivo conditions. PMID:25421738

  6. Improved Membrane-Based Sensor Network for Reliable Gas Monitoring in the Subsurface

    PubMed Central

    Lazik, Detlef; Ebert, Sebastian

    2012-01-01

    A conceptually improved sensor network to monitor the partial pressure of CO2 in different soil horizons was designed. Consisting of five membrane-based linear sensors (line-sensors) each with 10 m length, the set-up enables us to integrate over the locally fluctuating CO2 concentrations (typically lower 5%vol) up to the meter-scale gaining valuable concentration means with a repetition time of about 1 min. Preparatory tests in the laboratory resulted in a unexpected highly increased accuracy of better than 0.03%vol with respect to the previously published 0.08%vol. Thereby, the statistical uncertainties (standard deviations) of the line-sensors and the reference sensor (nondispersive infrared CO2-sensor) were close to each other. Whereas the uncertainty of the reference increases with the measurement value, the line-sensors show an inverse uncertainty trend resulting in a comparatively enhanced accuracy for concentrations >1%vol. Furthermore, a method for in situ maintenance was developed, enabling a proof of sensor quality and its effective calibration without demounting the line-sensors from the soil which would disturb the established structures and ongoing processes. PMID:23235447

  7. Conductivity Scaling Relationships in Nanostructured Membranes based on Protic Polymerized Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Sanoja, Gabriel; Lynd, Nathaniel; Segalman, Rachel

    2015-03-01

    Nanostructured membranes based on protic polymerized ionic liquids are of great interest for a variety of electrochemical applications. Understanding the relationship between composition, structure, and ionic conductivity for these materials is essential for designing novel membranes with improved properties. In this work, we explore the effect of volume fraction of ionic liquid on conductivity, σ using a model system composed of poly[isoprene-block-(ethylene oxide-stat-histamine glycidyl ether) diblock copolymers [PI- b - P(EO-stat-HGE)] and the resulting [PI- b - P(EO-stat-IL)] obtained after treatment with trifluoroacetic acid. These materials self-assemble into lamellar structures with volume fractions of ionic liquid ranging from 0.50 to 0.90 as demonstrated by SAXS. PI- b - P(EO-stat-IL) membranes exhibit conductivities up to 4 x 10-3 S/cm at room temperature. In addition, PI- b - P(EO-stat-IL) based membranes have lower water uptake (λ = 8-10) in comparison with most proton conducting membranes reported elsewhere. The low λ in these membranes might translate into a stronger effect of morphology on transport properties. Joint Center for Artificial Photosynthesis.

  8. A membrane-based subsystem for water-vapor recovery from plant-growth chambers

    NASA Technical Reports Server (NTRS)

    Ray, R. J.

    1992-01-01

    Bioregenerative systems--life-support systems to regenerate oxygen, food, and water--are the key to establishing man's permanent presence in space. NASA is investigating the use of plant-growth chambers (PGC's) for space missions and for bases on the moon and Mars. PGC's serve several important purposes, including the following: (1) oxygen and food production; (2) carbon-dioxide removal; and (3) water purification and reuse. The key to the successful development of PGC's is a system to recover and reuse the water vapor that is transpired by the leaves of the growing plants. In this program we propose to develop a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in the PGC. This system has characteristics that make it ideally suited to use in space: (1) minimal power requirements; (2) small volume and mass; (3) simplicity; (4) reliability; and (5) versatility. In Phase 1 we will do the following: (1) develop an accurate, predictive model of our temperature- and humidity-control system, based on parametric tests of membrane modules; and (2) use this model to design systems for selected PGC's. In Phase 2, we will seek to design, fabricate, test, and deliver a breadboard unit to NASA for testing on a PGC.

  9. Flexible conductive polypyrrole nanocomposite membranes based on bacterial cellulose with amphiphobicity.

    PubMed

    Tang, Lian; Han, Jinlu; Jiang, Zhenlin; Chen, Shiyan; Wang, Huaping

    2015-03-06

    Flexible conductive polypyrrole nanocomposite membranes based on bacterial cellulose (BC) with amphiphobicity have been successfully prepared through in situ chemical synthesis and then infiltrated with polysiloxane solution. The results suggested that polypyrrole (PPy) nanoparticles deposited on the surface of BC formed a continuous core-shell structure by taking along the BC template. After modification with polysiloxane, the surface characteristics of the conductive BC membranes changed from highly hydrophilic to hydrophobic. The AFM images revealed that the roughness of samples after polysiloxane treatment increased along with the increase of pyrrole concentration. The contact angles (CAs) data revealed that the highest water contact angle and highest oil contact angle are 160.3° and 136.7°, respectively. The conductivity of the amphiphobic membranes with excellent flexibility reached 0.32 S/cm and demonstrated a good electromagnetic shielding effectiveness with an SE of 15 dB which could be applied in electromagnetic shielding materials with self-cleaning properties. It opened a new field of potential applications of BC materials. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  10. 2D fluorescence spectroscopy for monitoring ion-exchange membrane based technologies - Reverse electrodialysis (RED).

    PubMed

    Pawlowski, Sylwin; Galinha, Claudia F; Crespo, João G; Velizarov, Svetlozar

    2016-01-01

    Reverse electrodialysis (RED) is one of the emerging, membrane-based technologies for harvesting salinity gradient energy. In RED process, fouling is an undesirable operation constraint since it leads to a decrease of the obtainable net power density due to increasing stack electric resistance and pressure drop. Therefore, early fouling detection is one of the main challenges for successful RED technology implementation. In the present study, two-dimensional (2D) fluorescence spectroscopy was used, for the first time, as a tool for fouling monitoring in RED. Fluorescence excitation-emission matrices (EEMs) of ion-exchange membrane surfaces and of natural aqueous streams were acquired during one month of a RED stack operation. Fouling evolvement on the ion-exchange membrane surfaces was successfully followed by 2D fluorescence spectroscopy and quantified using principal components analysis (PCA). Additionally, the efficiency of cleaning strategy was assessed by measuring the membrane fluorescence emission intensity before and after cleaning. The anion-exchange membrane (AEM) surface in contact with river water showed to be significantly affected due to fouling by humic compounds, which were found to cross through the membrane from the lower salinity (river water) to higher salinity (sea water) stream. The results obtained show that the combined approach of using 2D fluorescence spectroscopy and PCA has a high potential for studying fouling development and membrane cleaning efficiency in ion exchange membrane processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Structure of a membrane-based steric chaperone in complex with its lipase substrate.

    PubMed

    Pauwels, Kris; Lustig, Ariel; Wyns, Lode; Tommassen, Jan; Savvides, Savvas N; Van Gelder, Patrick

    2006-04-01

    Secretion via the type II secretion pathway in Gram-negative bacteria often relies crucially on steric chaperones in the periplasm. Here, we report the crystal structure of the soluble form of a lipase-specific foldase (Lif) from Burkholderia glumae in complex with its cognate lipase. The structure reveals how Lif uses a novel alpha-helical scaffold to embrace lipase, thereby creating an unusually extensive folding platform.

  12. Solubility and Phase Behavior of CL20 in Supercritical Fluids

    DTIC Science & Technology

    2006-09-01

    the system was modeled in FORTRAN computer language with a cubic equation of state such as Peng - Robinson Equation of State (Peng and Robinson 1976...Soave or the Peng Robin- son equations. The Peng - Robinson equation is used in this work. The Peng - Robinson equation for a mixture is (Modell and Reid...parameters. For the Peng - Robinson equation of state, these mix- ture parameters are evaluated from mixing rules where the pure component analogues

  13. Sequential Vapor Infiltration Treatment Enhances the Ionic Current Rectification Performance of Composite Membranes Based on Mesoporous Silica Confined in Anodic Alumina.

    PubMed

    Liang, Yanyan; Liu, Zhengping

    2016-12-20

    Ionic current rectification of nanofluidic diode membranes has been studied widely in recent years because it is analogous to the functionality of biological ion channels in principle. We report a new method to fabricate ionic current rectification membranes based on mesoporous silica confined in anodic aluminum oxide (AAO) membranes. Two types of mesostructured silica nanocomposites, hexagonal structure and nanoparticle stacked structure, were used to asymmetrically fill nanochannels of AAO membranes by a vapor-phase synthesis (VPS) method with aspiration approach and were further modified via sequence vapor infiltration (SVI) treatment. The ionic current measurements indicated that SVI treatment can modulate the asymmetric ionic transport in prepared membranes, which exhibited clear ionic current rectification phenomenon under optimal conditions. The ionic current rectifying behavior is derived from the asymmetry of surface conformations, silica species components, and hydrophobic wettability, which are created by the asymmetrical filling type, silica depositions on the heterogeneous membranes, and the condensation of silanol groups. This article provides a considerable strategy to fabricate composite membranes with obvious ionic current rectification performance via the cooperation of the VPS method and SVI treatment and opens up the potential of mesoporous silica confined in AAO membranes to mimic fluid transport in biological processes.

  14. Drilling fluids and thinners therefor

    SciTech Connect

    Allison, G.M. III

    1986-10-21

    This patent describes an aqueous drilling fluid comprising water, finely divided solids and a first agent and a second agent. The first agent comprises a sulfoalkylated tannin containing no complexing heavy metal. The second agent comprises at least one at least partly water-soluble metal compound comprising tin. The weight ratio of the first agent to the second agent is in the range from about 100;1 to about 1:1.

  15. Transfer of a Mycobacterium tuberculosis genotyping method, Spoligotyping, from a reverse line-blot hybridization, membrane-based assay to the Luminex multianalyte profiling system.

    PubMed

    Cowan, Lauren S; Diem, Lois; Brake, Mary Catherine; Crawford, Jack T

    2004-01-01

    Spoligotyping using Luminex technology was shown to be a highly reproducible method suitable for high-throughput analysis. Spoligotyping of 48 isolates using the traditional membrane-based assay and the Luminex assay yielded concordant results for all isolates. The Luminex platform provides greater flexibility and cost effectiveness than the membrane-based assay.

  16. Transfer of a Mycobacterium tuberculosis Genotyping Method, Spoligotyping, from a Reverse Line-Blot Hybridization, Membrane-Based Assay to the Luminex Multianalyte Profiling System

    PubMed Central

    Cowan, Lauren S.; Diem, Lois; Brake, Mary Catherine; Crawford, Jack T.

    2004-01-01

    Spoligotyping using Luminex technology was shown to be a highly reproducible method suitable for high-throughput analysis. Spoligotyping of 48 isolates using the traditional membrane-based assay and the Luminex assay yielded concordant results for all isolates. The Luminex platform provides greater flexibility and cost effectiveness than the membrane-based assay. PMID:14715809

  17. Water soluble laser dyes

    DOEpatents

    Hammond, Peter R.; Feeman, James F.; Field, George F.

    1998-01-01

    Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

  18. Water soluble laser dyes

    DOEpatents

    Hammond, P.R.; Feeman, J.F.; Field, G.F.

    1998-08-11

    Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

  19. The Solubility of Nitrogen and Air in Liquids

    NASA Astrophysics Data System (ADS)

    Battino, Rubin; Rettich, Timothy R.; Tominaga, Toshihiro

    1984-04-01

    This review covers the solubility of nitrogen and air in liquids as a function of temperature and pressure. Solubility data for individual systems were critically evaluated. Recommended or tentative values are presented as smoothing equations and/or in tabular form. Trends in homologous series or related solvents are discussed. Data for the n-alkanes were smoothed with respect to temperature, pressure, and carbon number. Liquids include: water; heavy water; seawater; aqueous salt solutions; mixed solvents; hydrocarbons; organic compounds containing oxygen, halogen, sulfur, nitrogen, or silicon; olive oil; various biological fluids; H2S; SO2; NH3; CO2; nitrogen oxides; and several halogen and boron containing inorganic solvents.

  20. Differential membrane-based nanocalorimeter for high-resolution measurements of low-temperature specific heat.

    PubMed

    Tagliati, S; Krasnov, V M; Rydh, A

    2012-05-01

    A differential, membrane-based nanocalorimeter for general specific heat studies of very small samples, ranging from 0.5 mg to sub-μg in mass, is described. The calorimeter operates over the temperature range from above room temperature down to 0.5 K. It consists of a pair of cells, each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane, in total giving a background heat capacity less than 100 nJ/K at 300 K, decreasing to 10 pJ/K at 1 K. The device has several distinctive features: (i) The resistive thermometer, made of a Ge(1 - x)Au(x) alloy, displays a high dimensionless sensitivity ∣dlnR∕dlnT∣ ≳ 1 over the entire temperature range. (ii) The sample is placed in direct contact with the thermometer, which is allowed to self-heat. The thermometer can thus be operated at high dc current to increase the resolution. (iii) Data are acquired with a set of eight synchronized lock-in amplifiers measuring dc, 1st and 2nd harmonic signals of heaters and thermometer. This gives high resolution and allows continuous output adjustments without additional noise. (iv) Absolute accuracy is achieved via a variable-frequency-fixed-phase technique in which the measurement frequency is automatically adjusted during the measurements to account for the temperature variation of the sample heat capacity and the device thermal conductance. The performance of the calorimeter is illustrated by studying the heat capacity of a small Au sample and the specific heat of a 2.6 μg piece of superconducting Pb in various magnetic fields.

  1. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications

    PubMed Central

    Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D.; Edelstein, Paul H.; Collman, Ronald G.; Bau, Haim H.

    2014-01-01

    Often, high sensitivity, point of care, clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low abundance target molecules. We report on a simple to use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a “blood in-plasma out” capability, consistently extracting 275 ±33.5 μL of plasma from 1.8 mL of undiluted whole blood in less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3,500 and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid Testing And Was Successfully Subjected To Reverse Transcriptase Loop mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high efficiency nucleic acid amplification. PMID:24099566

  2. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications.

    PubMed

    Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H

    2013-11-05

    Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.

  3. Potentiometric Response Characteristics of Membrane-Based Cs + -Selective Electrodes Containing Ionophore-Functionalized Polymeric Microspheres

    DOE PAGES

    Peper, Shane; Gonczy, Chad

    2011-01-01

    Csmore » + -selective solvent polymeric membrane-based ion-selective electrodes (ISEs) were developed by doping ethylene glycol-functionalized cross-linked polystyrene microspheres (P-EG) into a plasticized poly(vinyl chloride) (PVC) matrix containing sodium tetrakis-(3,5-bis(trifluoromethyl)phenyl) borate (TFPB) as the ion exchanger. A systematic study examining the effects of the membrane plasticizers bis(2-ethylhexyl) sebacate (DOS), 2-nitrophenyl octyl ether (NPOE), and 2-fluorophenyl nitrophenyl ether (FPNPE) on the potentiometric response and selectivity of the corresponding electrodes was performed. Under certain conditions, P-EG-based ion-selective electrodes (ISEs) containing TFPB and plasticized with NPOE exhibited a super-Nernstian response between 1 × 10 − 3 and 1 × 10 − 4  M+ , a response characteristic not observed in analogous membranes plasticized with either DOS or FPNPE. Additionally, the performance of P-EG-based ISEs was compared to electrodes based on two mobile ionophores, a neutral lipophilic ethylene glycol derivative (ethylene glycol monooctadecyl ether (U-EG)) and a charged metallacarborane ionophore, sodium bis(dicarbollyl)cobaltate(III) (CC). In general, P-EG-based electrodes plasticized with FPNPE yielded the best performance, with a linear range from 10 -1 –10 -5  M+ , a conventional lower detection limit of 8.1 × 10 − 6  M+ , and a response slope of 57.7 mV/decade. The pH response of P-EG ISEs containing TFPB was evaluated for membranes plasticized with either NPOE or FPNPE. In both cases, the electrodes remained stable throughout the pH range 3–12, with only slight proton interference observed below pH 3.« less

  4. A membrane-based microfluidic device for controlling the flux of platelet agonists into flowing blood†

    PubMed Central

    Neeves, Keith B.; Diamond, Scott L.

    2008-01-01

    The flux of platelet agonists into flowing blood is a critical event in thrombosis and hemostasis. However, few in vitro methods exist for examining and controlling the role of platelet agonists on clot formation and stability under hemodynamic conditions. In this paper, we describe a membrane-based method for introducing a solute into flowing blood at a defined flux. The device consisted of a track-etched polycarbonate membrane reversibly sealed between two microfluidic channels; one channel contained blood flowing at a physiologically relevant shear rate, and the other channel contained the agonist(s). An analytical model described the solute flux as a function of the membrane permeability and transmembrane pressure. The model was validated using luciferase as a model solute for transmembrane pressures of 50–400 Pa. As a proof-of-concept, the weak platelet agonist ADP was introduced into whole blood flowing at 250 s−1 at three fluxes (1.5, 2.4, and 4.4 × 10−18 mol μm−2 s−1). Platelet aggregation was monitored by fluorescence microscopy during the experiment and the morphology of aggregates was determined by post hoc confocal and electron microscopy. At the lowest flux (1.5 × 10−18 mol μm−2 s−1), we observed little to no aggregation. At the higher fluxes, we observed monolayer (2.4 × 10−18 mol μm−2 s−1) and multilayer (4.4 × 10−18 mol μm−2 s−1) aggregates of platelets and found that the platelet density within an aggregate increased with increasing ADP flux. We expect this device to be a useful tool in unraveling the role of platelet agonists on clot formation and stability. PMID:18432339

  5. Basement Membrane-Based Glucose Sensor Coatings Enhance Continuous Glucose Monitoring in Vivo

    PubMed Central

    Klueh, Ulrike; Qiao, Yi; Czajkowski, Caroline; Ludzinska, Izabela; Antar, Omar; Kreutzer, Donald L.

    2015-01-01

    Background: Implantable glucose sensors demonstrate a rapid decline in function that is likely due to biofouling of the sensor. Previous efforts directed at overcoming this issue has generally focused on the use of synthetic polymer coatings, with little apparent effect in vivo, clearly a novel approach is required. We believe that the key to extending sensor life span in vivo is the development of biocompatible basement membrane (BM) based bio-hydrogels as coatings for glucose sensors. Method: BM based bio-hydrogel sensor coatings were developed using purified BM preparations (ie, Cultrex from Trevigen Inc). Modified Abbott sensors were coated with Cultrex BM extracts. Sensor performance was evaluated for the impact of these coatings in vitro and in vivo in a continuous glucose monitoring (CGM) mouse model. In vivo sensor function was assessed over a 28-day time period expressed as mean absolute relative difference (MARD) values. Tissue reactivity of both Cultrex coated and uncoated glucose sensors was evaluated at 7, 14, 21 and 28 days post–sensor implantation with standard histological techniques. Results: The data demonstrate that Cultrex-based sensor coatings had no effect on glucose sensor function in vitro. In vivo glucose sensor performance was enhanced following BM coating as determined by MARD analysis, particularly in weeks 2 and 3. In vivo studies also demonstrated that Cultrex coatings significantly decreased sensor-induced tissue reactions at the sensor implantation sites. Conclusion: Basement-membrane-based sensor coatings enhance glucose sensor function in vivo, by minimizing or preventing sensor-induced tissues reactions. PMID:26306494

  6. A membrane-based purification process for cell culture-derived influenza A virus.

    PubMed

    Weigel, Thomas; Solomaier, Thomas; Wehmeyer, Sebastian; Peuker, Alessa; Wolff, Michael W; Reichl, Udo

    2016-02-20

    A simple membrane-based purification process for cell culture-derived influenza virus was established that relies on only two chromatographic unit operations to achieve the contamination limits required according to regulatory authorities. After clarification and concentration, a pseudo-affinity membrane adsorber (sulfated cellulose, SCMA) was applied for virus capture. The subsequent polishing step consisted of a salt-tolerant anion exchange membrane adsorber (STMA) to bind residual DNA. For the presented process neither a buffer exchange step nor a nuclease step for further DNA digestion were required. As a starting point, a two-salt strategy (including a polyvalent ion) was employed to screen STMA conditions in a 96-well plate format. After optimization on chromatographic laboratory scale, the virus recovery was up to 97% with a residual DNA level below 0.82%. In addition, the STMA was characterized regarding its dynamic binding capacity and the impact of flow rate on yields and contamination levels. Overall, the total virus yield for influenza virus A/PR/8/34 (H1/N1) of this two-step membrane process was 75%, while the protein and the DNA contamination level could be reduced to 24% and at least 0.5%, respectively. With 19.8μg protein and 1.2ng DNA per monovalent dose, this purity level complies with the limits of the European Pharmacopeia for cell culture-derived vaccines for human use. Overall, the presented downstream process might serve as a generic and economic platform technology for production of cell culture-derived viruses and viral vectors.

  7. A large format membrane-based x-ray mask for microfluidic chip fabrication

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Zhang, Min; Desta, Yohannes; Melzak, J.; Wu, C. H.; Peng, Zhengchun

    2006-02-01

    X-ray lithography is a very good option for the fabrication of micro-devices especially when high aspect ratio patterns are required. Membrane-based x-ray masks are commonly used for high-resolution x-ray lithography. A thin layer of silicon nitride (Si3N4) or silicon carbide (SiC) film (1-2 µm) is normally used as the membrane material for x-ray mask fabrication (Wells G M, Reilly M, Nachman R, Cerrina F, El-Khakani M A and Chaker M 1993 Mater. Res. Soc. Conf. Proc. 306 81-9 Shoki T, Nagasawa H, Kosuga H, Yamaguchi Y, Annaka N, Amemiya I and Nagarekawa O 1993 SPIE Proc. 1924 450-6). The freestanding membrane window of an x-ray mask, which defines the exposing area of the x-ray mask, can be obtained by etching a pre-defined area on a silicon wafer from the backside (Wang L, Desta Y, Fettig R K, Goettert J, Hein H, Jakobs P and Chulz J 2004 J. Micromech. Microeng. 14 722-6). Usually, the window size of an x-ray mask is around 20 × 20 mm because of the low tensile stress of the membrane (10-100 MPa), and the larger window dimension of an x-ray mask may cause the deformation of membranes and lower the mask quality. However, x-ray masks with larger windows are preferred for micro-device fabrication in order to increase the productivity. We analyzed the factors which influence the flatness of large format x-ray masks and fabricated x-ray masks with a window size of 55 × 55 mm and 46 × 65 mm on 1 µm thick membranes by increasing the tensile stress of the membranes (>300 MPa) and optimizing the stress of the absorber layer. The large format x-ray mask was successfully applied for the fabrication of microfluidic chips.

  8. Differential membrane-based nanocalorimeter for high-resolution measurements of low-temperature specific heat

    NASA Astrophysics Data System (ADS)

    Tagliati, S.; Krasnov, V. M.; Rydh, A.

    2012-05-01

    A differential, membrane-based nanocalorimeter for general specific heat studies of very small samples, ranging from 0.5 mg to sub-μg in mass, is described. The calorimeter operates over the temperature range from above room temperature down to 0.5 K. It consists of a pair of cells, each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane, in total giving a background heat capacity less than 100 nJ/K at 300 K, decreasing to 10 pJ/K at 1 K. The device has several distinctive features: (i) The resistive thermometer, made of a Ge1 - xAux alloy, displays a high dimensionless sensitivity |dlnR/dlnT| ≳ 1 over the entire temperature range. (ii) The sample is placed in direct contact with the thermometer, which is allowed to self-heat. The thermometer can thus be operated at high dc current to increase the resolution. (iii) Data are acquired with a set of eight synchronized lock-in amplifiers measuring dc, 1st and 2nd harmonic signals of heaters and thermometer. This gives high resolution and allows continuous output adjustments without additional noise. (iv) Absolute accuracy is achieved via a variable-frequency-fixed-phase technique in which the measurement frequency is automatically adjusted during the measurements to account for the temperature variation of the sample heat capacity and the device thermal conductance. The performance of the calorimeter is illustrated by studying the heat capacity of a small Au sample and the specific heat of a 2.6 μg piece of superconducting Pb in various magnetic fields.

  9. Paper membrane-based SERS platform for the determination of glucose in blood samples.

    PubMed

    Torul, Hilal; Çiftçi, Hakan; Çetin, Demet; Suludere, Zekiye; Boyacı, Ismail Hakkı; Tamer, Uğur

    2015-11-01

    In this report, we present a paper membrane-based surface-enhanced Raman scattering (SERS) platform for the determination of blood glucose level using a nitrocellulose membrane as substrate paper, and the microfluidic channel was simply constructed by wax-printing method. The rod-shaped gold nanorod particles were modified with 4-mercaptophenylboronic acid (4-MBA) and 1-decanethiol (1-DT) molecules and used as embedded SERS probe for paper-based microfluidics. The SERS measurement area was simply constructed by dropping gold nanoparticles on nitrocellulose membrane, and the blood sample was dropped on the membrane hydrophilic channel. While the blood cells and proteins were held on nitrocellulose membrane, glucose molecules were moved through the channel toward the SERS measurement area. Scanning electron microscopy (SEM) was used to confirm the effective separation of blood matrix, and total analysis is completed in 5 min. In SERS measurements, the intensity of the band at 1070 cm(-1) which is attributed to B-OH vibration decreased depending on the rise in glucose concentration in the blood sample. The glucose concentration was found to be 5.43 ± 0.51 mM in the reference blood sample by using a calibration equation, and the certified value for glucose was 6.17 ± 0.11 mM. The recovery of the glucose in the reference blood sample was about 88 %. According to these results, the developed paper-based microfluidic SERS platform has been found to be suitable for use for the detection of glucose in blood samples without any pretreatment procedure. We believe that paper-based microfluidic systems may provide a wide field of usage for paper-based applications.

  10. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Lauriie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Ribeiro, L.; hide

    2016-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low-Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 50% of ISS astronauts experienced more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's preflight conditions and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. METHODS: We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by

  11. Wellbore fluid

    SciTech Connect

    Dorsey, D.L.; Corley, W.T.

    1983-12-27

    A clay-based or clay-free aqueous thixotropic wellbore fluid having improved fluid loss control, desirable flow characteristics and low shale sensitivity for use in drilling a well comprising water or a brine base including an effective amount of an additive comprising a crosslinked potato starch, a heteropolysaccharide derived from a carbohydrate by bacteria of the genus Xanthomonas, and hydroxyethylcellulose or carboxymethylcellulose, is disclosed. This drilling fluid has been found to be nondamaging to the formations through which the well is drilled.

  12. Fluid inflation

    SciTech Connect

    Chen, X.; Firouzjahi, H.; Namjoo, M.H.; Sasaki, M. E-mail: firouz@ipm.ir E-mail: misao@yukawa.kyoto-u.ac.jp

    2013-09-01

    In this work we present an inflationary mechanism based on fluid dynamics. Starting with the action for a single barotropic perfect fluid, we outline the procedure to calculate the power spectrum and the bispectrum of the curvature perturbation. It is shown that a perfect barotropic fluid naturally gives rise to a non-attractor inflationary universe in which the curvature perturbation is not frozen on super-horizon scales. We show that a scale-invariant power spectrum can be obtained with the local non-Gaussianity parameter f{sub NL} = 5/2.

  13. The Ksp-Solubility Conundrum.

    ERIC Educational Resources Information Center

    Clark, Roy W.; Bonicamp, Judith M.

    1998-01-01

    Argues that there are only a few cases in which solubility and Ksp are related in a simple way. States that illustrations of the solubility product principle for one-to-one salts are adequate for students. Contains 23 references. (DDR)

  14. Tough, soluble, aromatic, thermoplastic copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    1994-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as acetamide, Nmethylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  15. The Ksp-Solubility Conundrum.

    ERIC Educational Resources Information Center

    Clark, Roy W.; Bonicamp, Judith M.

    1998-01-01

    Argues that there are only a few cases in which solubility and Ksp are related in a simple way. States that illustrations of the solubility product principle for one-to-one salts are adequate for students. Contains 23 references. (DDR)

  16. Detection of weak-binding sugar activity using membrane-based carbohydrates.

    PubMed

    Yamamoto, Kazuo; Kawasaki, Norihito

    2010-01-01

    Protein-sugar interactions underlie many biological events. Although protein-sugar interactions are weak, they are regulated in physiological conditions including clustering, association with other proteins, pH condition, and so on. The elucidation of the precise specificities of sugar-binding proteins is essential for understanding their biological functions. To detect the weak-binding activity of carbohydrate-binding proteins to sugar ligands, we studied lectin tetramer binding to cell-surface carbohydrates by flow cytometry. Tetramerization of lectins enhanced their avidity for sugar ligands, and sugar chains displayed on the cell surfaces were easily accessible to such soluble lectins. In this chapter, we describe methods to (1) prepare biotinylated soluble lectin, (2) obtain R-phycoerythrin-labeled lectin tetramer, and (3) measure tetramer binding to various lectin-resistant cell lines or cells treated with sugar-processing inhibitors. This approach enabled us to detect the weak sugar-binding activity of lectins (K(a) approximately 10(4)M(-1)), especially those from animals, and also to elucidate their specificity for sugar ligands. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  17. Workover fluid

    SciTech Connect

    Shell, F. J.

    1985-12-17

    The high temperature water loss property of alkaline well completion and well workover fluids is improved by the addition of an effective amount of a naphthalene sulfonate formaldehyde condensate in the form of its monovalent or bivalent metal salts.

  18. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Laurie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Lui, J.; hide

    2015-01-01

    INTRODUCTION: Mechanisms responsible for the ocular structural and functional changes that characterize the visual impairment and intracranial pressure (ICP) syndrome (VIIP) are unclear, but hypothesized to be secondary to the cephalad fluid shift experienced in spaceflight. This study will relate the fluid distribution and compartmentalization associated with long-duration spaceflight with VIIP symptoms. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, can be predicted preflight with acute hemodynamic manipulations, and also if lower body negative pressure (LBNP) can reverse the VIIP effects. METHODS: Physiologic variables will be examined pre-, in- and post-flight in 10 International Space Station crewmembers including: fluid compartmentalization (D2O and NaBr dilution); interstitial tissue thickness (ultrasound); vascular dimensions and dynamics (ultrasound and MRI (including cerebrospinal fluid pulsatility)); ocular measures (optical coherence tomography, intraocular pressure, ultrasound); and ICP measures (tympanic membrane displacement, otoacoustic emissions). Pre- and post-flight measures will be assessed while upright, supine and during 15 deg head-down tilt (HDT). In-flight measures will occur early and late during 6 or 12 month missions. LBNP will be evaluated as a countermeasure during HDT and during spaceflight. RESULTS: The first two crewmembers are in the preflight testing phase. Preliminary results characterize the acute fluid shifts experienced from upright, to supine and HDT postures (increased stroke volume, jugular dimensions and measures of ICP) which are reversed with 25 millimeters Hg LBNP. DISCUSSION: Initial results indicate that acute cephalad fluid shifts may be related to VIIP symptoms, but also may be reversible by LBNP. The effect of a chronic fluid shift has yet to be evaluated. Learning Objectives: Current spaceflight VIIP research is described

  19. Electrorheological fluids

    SciTech Connect

    Halsey, T.C.; Martin, J.E.

    1993-10-01

    An electrorheological fluid is a substance whose form changes in the presence of electric fields. Depending on the strength of the field to which it is subjected, an electrorheological fluid can run freely like water, ooze like honey or solidify like gelatin. Indeed, the substance can switch from ne state to another within a few milliseconds. Electrorheological fluids are easy to make; they consist of microscopic particles suspended in an insulating liquid. Yet they are not ready for most commercial applications. They tend to suffer from a number of problems, including structural weakness as solids, abrasiveness as liquids and chemical breakdown, especially at high temperatures. Automotive engineers could imagine, for instance, constructing an electrorheological clutch. It was also hoped that electrorheological fluids would lead to valveless hydraulic systems, in which solidifying fluid would shut off flow through a thin section of pipe. Electrorheological fluids also offer the possibility of a shock absorber that provides response times of milliseconds and does not require mechanical adjustments. 3 refs.

  20. Recombinant soluble adenovirus receptor

    DOEpatents

    Freimuth, Paul I.

    2002-01-01

    Disclosed are isolated polypeptides from human CAR (coxsackievirus and adenovirus receptor) protein which bind adenovirus. Specifically disclosed are amino acid sequences which corresponds to adenovirus binding domain D1 and the entire extracellular domain of human CAR protein comprising D1 and D2. In other aspects, the disclosure relates to nucleic acid sequences encoding these domains as well as expression vectors which encode the domains and bacterial cells containing such vectors. Also disclosed is an isolated fusion protein comprised of the D1 polypeptide sequence fused to a polypeptide sequence which facilitates folding of D1 into a functional, soluble domain when expressed in bacteria. The functional D1 domain finds application for example in a therapeutic method for treating a patient infected with a virus which binds to D1, and also in a method for identifying an antiviral compound which interferes with viral attachment. Also included is a method for specifically targeting a cell for infection by a virus which binds to D1.

  1. A colorimetric reaction to quantify fluid mixing

    NASA Astrophysics Data System (ADS)

    Oates, Peter M.; Harvey, Charles F.

    2006-11-01

    We found the colorimetric reaction of Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid) and molybdate suitable for optical quantification of chemical reaction during fluid-fluid mixing in laboratory chambers. This reaction consists of two colorless reagents that mix to rapidly form colored, stable, soluble products. These products can be digitally imaged and quantified using light absorbance to study fluid-fluid mixing. Here we provide a model and equilibrium constants for the relevant complexation reactions. We also provide methods for relating light absorbance to product concentrations. Practical implementation issues of this reaction are discussed and an example of imaged absorbances for fluid-fluid mixing in heterogeneous porous media is given.

  2. "Ready-to-use" hollow nanofiber membrane-based glucose testing strips.

    PubMed

    Ji, Xiaoyuan; Su, Zhiguo; Wang, Ping; Ma, Guanghui; Zhang, Songping

    2014-12-21

    A novel "ready-to-use" glucose test strip based on a polyurethane hollow nanofiber membrane was fabricated through facile co-axial electrospinning. By utilizing glucose oxidase and horseradish peroxidase in the core-phase solution, and a chromogenic agent either in the core solution (in which case 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) was used) or in the shell-phase solution (in which case o-dianisidine was used) for co-axial electrospinning, in situ co-encapsulation of the two enzymes within the hollow nano-chamber and incorporation of chromogenic agents either inside the nano-chamber or in the shell of the hollow nanofibers was realized. Such unique "all-in-one" feature enabled the prepared hollow nanofiber membrane-based test strips to be applied either as colorimetric sensors in solution or as an optical biosensor operated in the "dip-and-read" mode. When used as a colorimetric biosensor in solution, the test strip with o-dianisidine as chromogenic agent shows an excellent linear response range between 0.01 mM to 20 mM and a high apparent lumped activity recovery of 62.1% as compared to the reaction rate of the free bi-enzyme system. While the activity recovery of the test strip with ABTS as chromogenic agent is only 18.0%, and the test strip is found to be unstable due to spontaneous-oxidation of the ABTS. The o-dianisidine test strip was also applied as an optical biosensor, visible rufous color was quickly developed on the surface of the membrane upon dropping 10 μL of glucose sample, and an excellent correlation between differential diffusive reflectance of the test strip at 440 nm and glucose concentration was obtained in the range of 0.5-50 mM. The test strips also exhibited excellent long-term storage stability with a half-life at 25 °C as long as four months.

  3. Fluid Management System (FMS) fluid systems overview

    NASA Technical Reports Server (NTRS)

    Baird, R. S.

    1990-01-01

    Viewgraphs on fluid management system (FMS) fluid systems overview are presented. Topics addressed include: fluid management system description including system requirements (integrated nitrogen system, integrated water system, and integrated waste gas system) and physical description; and fluid management system evolution.

  4. Numerical simulation of drop and bubble dynamics with soluble surfactant

    NASA Astrophysics Data System (ADS)

    Wang, Qiming; Siegel, Michael; Booty, Michael R.

    2014-05-01

    Numerical computations are presented to study the effect of soluble surfactant on the deformation and breakup of an axisymmetric drop or bubble stretched by an imposed linear strain flow in a viscous fluid. At the high values of bulk Peclet number Pe in typical fluid-surfactant systems, there is a thin transition layer near the interface in which the surfactant concentration varies rapidly. The large surfactant gradients are resolved using a fast and accurate "hybrid" numerical method that incorporates a separate, singular perturbation analysis of the dynamics in the transition layer into a full numerical solution of the free boundary problem. The method is used to investigate the dependence of drop deformation on parameters that characterize surfactant solubility. We also compute resolved examples of tipstreaming, and investigate its dependence on parameters such as flow rate and bulk surfactant concentration.

  5. Kill fluid for oil field operations

    SciTech Connect

    Sydansk, R.D.

    1990-08-14

    This patent describes a process employing a kill fluid to substantially reduce the volumetric flow of formation fluid into a wellbore penetrating a formation containing the formation fluid below an earthen surface. It comprises: admixing components of a continuous flowing gel at the surface comprising of water-soluble carboxylate-containing polymer, a complex capable of crosslinking the polymer and formed of at least one electropositive chromium III species and at least one electronegative carboxylatespecies, and an aqueous solvent for the polymer and the complex; crosslinking the polymer and the complex to form the gel, wherein the kill fluid comprises the gel; placing a volume of the kill fluid in the wellbore sufficient to create a hydrostatic head which exerts a kill fluid pressure against the formation fluid substantially equal to or greater than the formation fluid pressure and thereby substantially reduces the volumetric flow of the formation fluid into the wellbore; performing an oil field operation after placing the volume of the kill fluid in the wellbore; and removing the gel from the wellbore to substantially restore the volumetric flow of the formation fluid into the wellbore.

  6. Supercritical fluid technology

    SciTech Connect

    Penninger, J.M.L.; McHugh, M.A.; Radosz, M.; Krukonis, V.J.

    1985-01-01

    This book presents the state-of-the-art in the science and technology of supercritical fluid (scf) processing. Current research as described in the book, focuses on developments in equations of state for binary and multicomponent mixtures (including polymer solutions), solubility measurements at near-critical conditions, measurements of critical properties of binary mixtures and their correlation with equations of state. Progress in thermodynamics, coupled with advances in the design and construction of high pressure equipment, has opened up a wide avenue of commercial application (e.g. decaffeination of coffee beans, extractions of flavours and spices, purification of pharmaceutical products, separations of polymeric materials, deodorization and deacidification of vegetable oils, fractionation of fatty acids, coal liquefaction, wood delignitication, etc.)

  7. Solubility and trapping of helium in apatite

    NASA Astrophysics Data System (ADS)

    Zeitler, Peter K.; Enkelmann, Eva; Thomas, Jay B.; Watson, E. Bruce; Ancuta, Leonard D.; Idleman, Bruce D.

    2017-07-01

    A fundamental but unquantified assumption in U-Th/He dating of apatite is that grains do not incorporate extraneous helium by solution or other processes, but large age dispersion seen in some samples suggests that this assumption might be violated. Our laboratory experiments show that helium solubility in apatite is quite low and unlikely to lead to age dispersion in most samples. However, in some samples highly variable and sometimes large helium uptake suggests that apatite grains can trap helium in microvoids that could be derived from fluid inclusions or other microstructures, a conclusion supported by crushing and step-heating experiments. The presence of such microvoids raises the possibility that closure and age systematics could be complicated either by trapping of internally generated radiogenic helium and/or alteration of helium diffusion kinetics by impeding diffusion.

  8. Concomitant intake of alcohol may increase the absorption of poorly soluble drugs.

    PubMed

    Fagerberg, Jonas H; Sjögren, Erik; Bergström, Christel A S

    2015-01-25

    Ethanol can increase the solubility of poorly soluble and hence present a higher drug concentration in the gastrointestinal tract. This may produce a faster and more effective absorption resulting in variable and/or high drug plasma concentrations, both of which can lead to adverse drug reactions. In this work we therefore studied the solubility and absorption effects of nine diverse compounds when ethanol was present. The apparent solubility was measured using the μDiss Profiler Plus (pION, MA) in four media representing gastric conditions with and without ethanol. The solubility results were combined with in-house data on solubility in intestinal fluids (with and without ethanol) and pharmacokinetic parameters extracted from the literature and used as input in compartmental absorption simulations using the software GI-Sim. Apparent solubility increased more than 7-fold for non-ionized compounds in simulated gastric fluid containing 20% ethanol. Compounds with weak base functions (cinnarizine, dipyridamole and terfenadine) were completely ionized at the studied gastric pH and their solubility was therefore unaffected by ethanol. Compounds with low solubility in intestinal media and a pronounced solubility increase due to ethanol in the upper gastric compartments showed an increased absorption in the simulations. The rate of absorption of the acidic compounds indomethacin and indoprofen was slightly increased but the extent of absorption was unaffected as the complete doses were readily absorbed even without ethanol. This was likely due to a high apparent solubility in the intestinal compartment where the weak acids are ionized. The absorption of the studied non-ionizable compounds increased when ethanol was present in the gastric and intestinal media. These results indicate that concomitant intake of alcohol may significantly increase the solubility and hence, the plasma concentration for non-ionizable, lipophilic compounds with the potential of adverse drug

  9. Students' mental models on the solubility and solubility product concept

    NASA Astrophysics Data System (ADS)

    Rahmi, Chusnur; Katmiati, Siti; Wiji, Mulyani, Sri

    2017-05-01

    This study aims to obtain some information regarding profile of students' mental models on the solubility and solubility product concept. A descriptive qualitative method was the method employed in the study. The participants of the study were students XI grade of a senior high school in Bandung. To collect the data, diagnostic test on mental model-prediction, observation, explanation (TDM-POE) instrument was employed in the study. The results of the study revealed that on the concept of precipitation formation of a reaction, 30% of students were not able to explain the precipitation formation of a reaction either in submicroscopic or symbolic level although the microscopic have been shown; 26% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, but they were not able to explain the interaction of particles that involved in the reaction and to calculate Qsp; 26% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, and determine the particles involved, but they did not have the knowledge about the interactions occured and were uncapable of calculating Qsp; and 18% of students were able to explain the precipitation formation of a reaction based on the relation of Qsp and Ksp, and determine the interactions of the particles involved in the reactions but they were not able to calculate Qsp. On the effect of adding common ions and decreasing pH towards the solubility concept, 96% of students were not able to explain the effect of adding common ions and decreasing pH towards the solubility either in submicroscopic or symbolic level although the microscopic have been shown; while 4% of students were only able to explain the effect of adding common ions towards the solubility based on the chemical equilibrium shifts and predict the effect of decreasing pH towards the solubility. However, they were not able to calculate the solubility before and after

  10. Supercritical fluid thermodynamics for coal processing

    SciTech Connect

    van Swol, F. . Dept. of Chemical Engineering); Eckert, C.A. . School of Chemical Engineering)

    1990-01-01

    Because of their unusual solvating and mass transfer properties, supercritical fluids show potential for a variety of coal processing applications. We have established a database of coal model compound equilibria; to add to this database, we have developed and are testing techniques of measuring entrainer effects on solubility rapidly. In addition, we have used fluorescence spectroscopy to study the nature of entrainer effects on a molecular level. The solubility and spectroscopic measurements are being used in the development of an equation of state that includes both physical and chemical interactions; we are currently testing the equation. The equation of state will be used to predict solubility behavior so systems can be designed for the processing of coal with supercritical fluids. 3 figs.

  11. Solubility of Injectable Valium in Intravenous Solutions

    PubMed Central

    Grower, Marvin F.; Russell, Emery A.; Getter, Lee

    1978-01-01

    A study of the solubility of Valium in commonly used intravenous solutions showed Valium to be equally insoluble in 5% dextrose in normal saline, 5% dextrose in water, normal saline, and Ringer's lactate. However, the precipitate which was formed became completely resuspended when mixed with as little as 39-42% plasma in vitro. This would indicate that the chalky precipitate seen in the I. V. tubing when Valium is injected into a running I. V. near the venipuncture site becomes resuspended when mixed with plasma in vivo. If one elects to inject Valium into the tubing of a running I. V., it is recommended that the drug be administered slowly to assure adequate mixing with blood plasma in order to prevent the circulation of particulate matter. Valium is currently one of the most popular drugs used in the psychosedative management of the apprehensive dental patient. Various techniques are advocated for its administration from direct injection into a vein to injection of the drug into a running I. V. However, the manufacturer states that the drug should not be added to I. V. fluids or other solutions or drugs. Presumably this is because of the formation of a cloudy precipitate immediately upon addition to aqueous solutions. Grower et al. have shown that saturated aqueous solutions of Valium in normal saline redissolve when added to plasma; however, they presented no data on the behavior of solutions of Valium added to other commonly used intravenous fluids. The present study was, therefore, undertaken to study the behavior of Valium when added to lactated Ringer's solution, 5% dextrose solutions, and normal saline; and to see how human blood plasma affects the solubility of Valium in these solutions. PMID:292338

  12. Understanding Solubility through Excel Spreadsheets

    NASA Astrophysics Data System (ADS)

    Brown, Pamela

    2001-02-01

    This article describes assignments related to the solubility of inorganic salts that can be given in an introductory general chemistry course. Le Châtelier's principle, solubility, unit conversion, and thermodynamics are tied together to calculate heats of solution by two methods: heats of formation and an application of the van't Hoff equation. These assignments address the need for math, graphing, and computer skills in the chemical technology program by developing skill in the use of Microsoft Excel to prepare spreadsheets and graphs and to perform linear and nonlinear curve-fitting. Background information on the value of understanding and predicting solubility is provided.

  13. Phenylated Polyimides With Greater Solubility

    NASA Technical Reports Server (NTRS)

    Harris, Frank W.

    1991-01-01

    In experiments, 3,6-diphenylpyromellitic dianhydride monomer prepared and polymerized with several different diamines. Polyimides with pendent phenyl groups along polymer backbones considerably more soluble than PMDA-based materials. Increased solubility eases processing, providing increased potential use in variety of applications. Because most polymers soluble in organic solvents, usable in microelectronics applications. Excellent thermal stabilities and high transition temperatures make them ideally suited. Many polymers extremely rigid and useful as reinforcing polymers in molecular composites. More flexible compositions useful as matrix resins in carbon-reinforced composites.

  14. Understanding, Classifying, and Selecting Environmentally Acceptable Hydraulic Fluids

    DTIC Science & Technology

    2016-08-01

    PAG)) – ISO Classification HEPG • Triglycerides ( vegetable oils) - ISO Classification HETG • Polyalphaolefins (PAO) and related hydrocarbon...polyethylene glycols) or oil-soluble (polypropylene glycols) synthesized from petrochemical starting materials • Triglycerides ( Vegetable Oils) – plant-based...Fluids (Rudnick 2009, USACE 1999) Parameter Hydraulic Fluid Type Vegetable Oil (HETG) Synthetic Ester (HEES) Polyglycol (HEPG) PAO & Related

  15. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, Michael; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.; hide

    2014-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 30% of ISS astronauts experience more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the space flight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration space flight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during space flight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's pre-flight condition and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by ultrasound

  16. Critical review of coupled flux formulations for clay membranes based on nonequilibrium thermodynamics.

    PubMed

    Malusis, Michael A; Shackelford, Charles D; Maneval, James E

    2012-09-01

    Extensive research conducted over the past several decades has indicated that semipermeable membrane behavior (i.e., the ability of a porous medium to restrict the passage of solutes) may have a significant influence on solute migration through a wide variety of clay-rich soils, including both natural clay formations (aquitards, aquicludes) and engineered clay barriers (e.g., landfill liners and vertical cutoff walls). Restricted solute migration through clay membranes generally has been described using coupled flux formulations based on nonequilibrium (irreversible) thermodynamics. However, these formulations have differed depending on the assumptions inherent in the theoretical development, resulting in some confusion regarding the applicability of the formulations. Accordingly, a critical review of coupled flux formulations for liquid, current, and solutes through a semipermeable clay membrane under isothermal conditions is undertaken with the goals of explicitly resolving differences among the formulations and illustrating the significance of the differences from theoretical and practical perspectives. Formulations based on single-solute systems (i.e., uncharged solute), single-salt systems, and general systems containing multiple cations or anions are presented. Also, expressions relating the phenomenological coefficients in the coupled flux equations to relevant soil properties (e.g., hydraulic conductivity and effective diffusion coefficient) are summarized for each system. A major difference in the formulations is shown to exist depending on whether counter diffusion or salt diffusion is assumed. This difference between counter and salt diffusion is shown to affect the interpretation of values for the effective diffusion coefficient in a clay membrane based on previously published experimental data. Solute transport theories based on both counter and salt diffusion then are used to re-evaluate previously published column test data for the same clay membrane

  17. Critical review of coupled flux formulations for clay membranes based on nonequilibrium thermodynamics

    NASA Astrophysics Data System (ADS)

    Malusis, Michael A.; Shackelford, Charles D.; Maneval, James E.

    2012-09-01

    Extensive research conducted over the past several decades has indicated that semipermeable membrane behavior (i.e., the ability of a porous medium to restrict the passage of solutes) may have a significant influence on solute migration through a wide variety of clay-rich soils, including both natural clay formations (aquitards, aquicludes) and engineered clay barriers (e.g., landfill liners and vertical cutoff walls). Restricted solute migration through clay membranes generally has been described using coupled flux formulations based on nonequilibrium (irreversible) thermodynamics. However, these formulations have differed depending on the assumptions inherent in the theoretical development, resulting in some confusion regarding the applicability of the formulations. Accordingly, a critical review of coupled flux formulations for liquid, current, and solutes through a semipermeable clay membrane under isothermal conditions is undertaken with the goals of explicitly resolving differences among the formulations and illustrating the significance of the differences from theoretical and practical perspectives. Formulations based on single-solute systems (i.e., uncharged solute), single-salt systems, and general systems containing multiple cations or anions are presented. Also, expressions relating the phenomenological coefficients in the coupled flux equations to relevant soil properties (e.g., hydraulic conductivity and effective diffusion coefficient) are summarized for each system. A major difference in the formulations is shown to exist depending on whether counter diffusion or salt diffusion is assumed. This difference between counter and salt diffusion is shown to affect the interpretation of values for the effective diffusion coefficient in a clay membrane based on previously published experimental data. Solute transport theories based on both counter and salt diffusion then are used to re-evaluate previously published column test data for the same clay membrane

  18. Development and understanding of new membranes based on aromatic polymers and heterocycles for fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Wen

    Direct methanol fuel cells (DMFC) are appealing as a power source for portable devices as they do not require recharging with an electrical outlet. However, the DMFC technology is confronted with the high crossover of methanol fuel from the anode to the cathode through the currently used Nafion membrane, which not only wastes the fuel but also poisons the cathode platinum catalyst. With an aim to overcome the problems encountered with the Nafion membrane, this dissertation focuses on the design and development of new polymeric membrane materials for DMFC and a fundamental understanding of their structure-property-performance relationships. Several polymeric blend membranes based on acid-base interactions between an aromatic acidic polymer such as sulfonated ploy(ether ether ketone) (SPEEK) and an aromatic basic polymer such as heterocycle tethered poly(sulfone) (PSf) have been explored. Various heterochylces like nitro-benzimidazole (NBIm), 1H-Perimidine (PImd), and 5-amino-benzotriazole (BTraz) have been tethered to PSf to understand the influence of pKa values and the size of the hetrocycles. The blend membranes show lower methanol crossover and better performance in DMFC than plain SPEEK due to an enhancement in proton conductivity through acid-base interactions and an insertion of the heterocycle side groups into the ionic clusters of SPEEK as indicated by small angle X-ray scattering and TEM data. The SPEEK/PSf-PImd blend membrane shows the lowest methanol crossover due to the larger size of the side groups, while the SPEEK/PSf-BTraz blend membrane shows the highest proton conductivity and maximum power density. To further investigate the methanol-blocking effect of the heterocycles, N,N'-Bis-(1H-benzimidazol-2-yl)-isophthalamide (BBImIP) having two amino-benzimidazole groups bonded to a phenyl ring has been incorporated into sulfonated polysulfone (SPSf) and SPEEK membranes. With two 2-amino-benzimidazole groups, which could greatly increase the proton

  19. New composite membranes based on modified Nafion or Flemion for PEM fuel cell application

    NASA Astrophysics Data System (ADS)

    Tian, Huimin

    A new composite membrane based on Nafion or Flemion and Silicotungstic acid (STA) was fabricated using a simple solvent evaporation procedure. The optimum evaporation temperature and the amount of STA have been investigated. The evaporation of solvent can be divided into two steps during membrane preparation. Firstly, the solvent was evaporated at 70°C for two hours. Secondly, the evaporated membrane was kept in an vacuum oven at 135°C overnight. The optimum amount of STA in the casting electrolyte solution is in the range from 5 x 10-4 to 5 x 10-3 M. The obtained cast composite membranes exhibit good thermal and mechanical properties. Study of the ionic conductivity shows that the composite membrane with STA gives a higher ionic conductivity than that without STA. The conductivity of composite membrane increases with the increase of STA concentration. When the STA concentration in the 10mL casting electrolyte solution is 5 x 10-3M, the conductivities of the composite membranes can reach up to 0.120 ohm-1 · cm-1 for Nafion/STA membrane and 0.133 ohm -1 · cm-1 for Flemion/STA membrane. On the other hand, the water uptake measurement shows that the water content of the composite membrane with STA is higher than that of composite membrane without STA. Consequently, due to the high conductivity and the high hydrated abiliy of STA, ionic conductivity and water uptake of the composite membrane can be significantly improved by the addition of STA. The morphology of the composite membrane was studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results of AFM and SEM showed that the STA was uniformly dispersed in the Nafion and Flemion composite membranes. The structure of a composite membrane with STA has been studied by X-ray diffraction (XRD), the fourier transform infrared spectroscopy (FTIR), thermoanalysis and X-ray photoelectron spectroscopy (XPS). The results indicated that STA was successfully introduced into the structure of

  20. The environmental applications and implications of nanotechnology in membrane-based separations for water treatment

    NASA Astrophysics Data System (ADS)

    Shan, Wenqian

    This dissertation presents results of three related projects focused on the applications of membrane separation technology to water treatment: 1) Experimental design and evaluation of polyelectrolyte multilayer films as regenerable membrane coatings with controllable surface properties; 2) Modeling of the interactions of nanoscale TiO2 and NOM molecules in aqueous solutions of environmentally relevant compositions; 3) Experimental design and preliminary testing of a membrane-based crossflow filtration hydrocyclone process for the separation of oil-in-water dispersions. Chapter 2 describes the design of polyelectrolyte multilayers as nanoscale membrane coatings and their application in nanofiltration of feed waters that contain suspended colloids and dissolved species. Layer-by-layer deposition of anionic and cationic polyelectrolytes was employed to prepare membrane coatings allowing for a fine control over their surface properties. This approach to membrane design also affords a possibility of regenerating coatings after they are fouled by colloids. This project demonstrated, for first time, the possibility of designing nanofiltration membranes with regenerable skin. Chapter 3 describes a study on the mechanisms of natural organic matter (NOM) adsorption onto the surface of titania nanoparticles. Titainia (TiO 2) is often used in the fabrication of ceramic membranes and understanding how NOM interacts with TiO2 can help to better predict ceramic membrane fouling by NOM-containing waters. The combined effect of pH and calcium on the interactions of nonozonated and ozonated NOM with nanoscale TiO 2 was investigated by applying extended Derjaguin --- Landau --- Verwey - Overbeek (XDLVO) modeling. XDLVO surface energy analysis predicted NOM adsorption onto TiO2 in the ozone-controlled regime but not in the calcium-controlled regime. In both regimes, short range NOM-NOM and NOM-TiO2 interactions were governed by acid-base and van der Waals forces, whereas the role of

  1. Water-soluble vitamins.

    PubMed

    Konings, Erik J M

    2006-01-01

    Simultaneous Determination of Vitamins.--Klejdus et al. described a simultaneous determination of 10 water- and 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were <6.5%. The concentrations of vitamins found in premixes with the method were comparable to the values declared. A disadvantage of the methods mentioned above is that sample composition has to be known in advance. According to European legislation, for example, foods might be fortified with riboflavin phosphate or thiamin phosphate, vitamers which are not included in the simultaneous separations described. Vitamin B2.--Viñas et al. elaborated an LC analysis of riboflavin vitamers in foods. Vitamin B2 can be found in nature as the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). Several methods usually involve the conversion of these coenzymes into free riboflavin before quantification of total riboflavin. According to the authors, there is growing interest to know flavin composition of foods. The described method separates the individual vitamers isocratically. Accuracy of the method is tested with 2 certified reference materials (CRMs). Vitamin B5.-Methods for the determination of vitamin B5 in foods are limited

  2. Method for estimating solubility parameter

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Ingham, J. D.

    1973-01-01

    Semiempirical correlations have been developed between solubility parameters and refractive indices for series of model hydrocarbon compounds and organic polymers. Measurement of intermolecular forces is useful for assessment of material compatibility, glass-transition temperature, and transport properties.

  3. water-soluble fluorocarbon coating

    NASA Technical Reports Server (NTRS)

    Nanelli, P.

    1979-01-01

    Water-soluble fluorocarbon proves durable nonpolluting coating for variety of substrates. Coatings can be used on metals, masonry, textiles, paper, and glass, and have superior hardness and flexibility, strong resistance to chemicals fire, and weather.

  4. Fluid Shifts

    NASA Technical Reports Server (NTRS)

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

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  5. Tough, Soluble, Aromatic, Thermoplastic Copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    1998-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  6. Pure Phase Solubility Limits: LANL

    SciTech Connect

    C. Stockman

    2001-01-26

    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  7. Uphill transport of rare-earth metals through a highly stable supported liquid membrane based on an ionic liquid.

    PubMed

    Kubota, Fukiko; Shimobori, Yousuke; Koyanagi, Yusuke; Shimojo, Kojiro; Kamiya, Noriho; Goto, Masahiro

    2010-01-01

    We have developed a highly stable supported liquid membrane based on ionic liquids (ILs) for the separation of rare-earth metals, employing N,N-dioctyldiglycol amic acid as a mobile carrier. The quantitative transport of Y and Eu through the membrane was successfully attained, and separation from metal impurities, Zn, was efficiently accomplished. A membrane stable enough for long-term operation was constructible from imidazolium-based ILs having a longer alkyl chain, such as octyl or dodecyl groups in an imidazolium cation.

  8. More than a drop in the bucket: decentralized membrane-based drinking water refill stations in southeast Asia.

    PubMed

    Sima, Laura C; Elimelech, Menachem

    2013-07-16

    Decentralized membrane-based water treatment and refill stations represent a viable and growing business model in Southeast Asia, which rely upon the purchase of water from refill stations by consumers. This feature article discusses these water treatment and refill stations, including the appropriateness of the technology, the suitability of the business models employed, and the long-term environmental and operational sustainability of these systems. We also provide an outlook for the sector, highlighting key technical challenges that need to be addressed in order to improve the capacity of these systems, such that they can become an effective and financially viable solution.

  9. The Effect of Hydrodynamic Slip on Membrane-Based Salinity-Gradient-Driven Energy Harvesting.

    PubMed

    Rankin, Daniel Justin; Huang, David Mark

    2016-04-12

    The effect of hydrodynamic slip on salinity-gradient-driven power conversion by the process of reverse electrodialysis, in which the free energy of mixing of salt and fresh water across a nanoporous membrane is harnessed to drive an electric current in an external circuit, is investigated theoretically using a continuum fluid dynamics model. A general one-dimensional model is derived that decouples transport inside the membrane pores from the effects of electrical resistance at the pore ends, from which an analytical expression for the power conversion rate is obtained for a perfectly ion-selective membrane as a function of the slip length, surface charge density, membrane thickness, pore radius, and other membrane and electrolyte properties. The theoretical model agrees quantitatively with finite-element numerical calculations and predicts significant enhancements--up to several times--of salinity-gradient power conversion due to hydrodynamic slip for realistic systems.

  10. The solubility of noble gases in crude oil at 25-100°C

    USGS Publications Warehouse

    Kharaka, Yousif K.; Specht, Daniel J.

    1988-01-01

    The solubility of the noble gases He, Ne, Ar, Kr and Xe was measured in two typical crude oils at temperatures of 25–100°C. The oil samples were obtained from the Elk Hills oil field located in southern San Joaquin Valley, California. The experimental procedure consisted of placing a known amount of gas with a known volume of crude oil in a stainless steel hydrothermal pressure vessel. The vessel was housed inside an oven and the entire unit rotates providing continuous mixing. The amount of gas dissolved in oil at a measured temperature and partial pressure of gas was used to calculate the solubility constants for these gases. Results show that the solubility of He and Ne in both oils is approximately the same; solubility then increases with atomic mass, with the solubility of Xe at 25°C being two orders of magnitude higher than that of He. The gas solubilities are somewhat higher in the lower density (higher API gravity) oil. The solubility of Ar is approximately constant in the range of temperatures of this study. The solubilities of He and Ne increase, but those of Kr and Xe decrease with increasing temperatures. Solubilities of noble gases in crude oil are significantly higher than their solubilities in water. For example, the solubilities of He and Xe at 25°C in the light oil of this study are, respectively, 3 and 24 times higher than their solubilities in pure water, and they are 15 and 300 times higher than in a brine with a salinity of 350,000 mg/l dissolved solids. These large and variable differences in the solubilities of noble gases in oil and water indicate that, in sedimentary basins with oil, these gases must be partitioned between oil, water and natural gas before they are used to deduce the origin and residence time of these fluids.

  11. Assessing the genotoxicity of industrial cutting fluids under conditions of use.

    PubMed

    Kleber, Marcus; Föllmann, Wolfram; Blaszkewicz, Meinolf

    2004-06-15

    Emulsions of water-soluble cutting fluids (wsCF) and non-water-soluble cutting fluids are used in large quantities for machining processes in the metal processing industry. From toxicological and epidemiological studies health risks resulting from handling of cutting fluids are well-known. Recently, the new technology of "minimist lubricant supply" (MLS) has been introduced which uses only minimal amounts of cutting fluids, in order to reduce the costs for use and disposal. This involves higher temperatures to which the fluids are subjected. Water-soluble cutting fluids supplemented with formaldehyde donors as biocides may lead to mutagenic potential. Current data show that attention should be given to generation of other genotoxic aldehydes from cutting fluids under condition of use, referring to both conventional and "minimist lubricant supply" technologies.

  12. Metalworking fluids and malignant melanoma in autoworkers.

    PubMed

    Costello, Sadie; Friesen, Melissa C; Christiani, David C; Eisen, Ellen A

    2011-01-01

    Occupational exposure to mineral oil-based metalworking fluids has been consistently linked with skin conditions such as contact dermatitis and squamous cell skin cancer, especially of the scrotum. We examined the incidence of malignant melanoma in a study of autoworkers. We followed a cohort of autoworkers from 1985 through 2004 for cancer incidence. Hazard ratios (HRs) were estimated in Cox models for cumulative exposure to total particulate of straight fluid (neat oil), soluble fluid (oil emulsified in water), and synthetic fluid (no oil). Exposure was partitioned into time windows by latency and by calendar periods defined by changes in the content of polycyclic aromatic hydrocarbon in the refined oils. The population was restricted to workers born after 1935. We examined the date-of-birth restriction in a sensitivity analysis. On the basis of 76 incident cases of malignant melanoma in the cohort of 14,139 white males, the HR was 1.99 (95% confidence interval = 1.00-3.96) for the highest category of straight fluid. Risk was greatest in the most recent time window. Penalized splines suggested a linear exposure-response over the full range of exposure. The change in HR for malignant melanoma per mg/m-year of straight fluid increased monotonically from 1.01 to 1.04, when the date-of-birth restriction increased from 1925 to 1945 in 5-year intervals. Results for soluble fluid were more modest. There was no association with synthetic fluid. Results provide evidence, based on quantitative measures of metalworking fluid, that oil-based fluid, particularly straight mineral oils, are associated with the incidence of malignant melanoma.

  13. Union soluble oil flood in El Dorado cores

    SciTech Connect

    Chiou, C.S.

    1983-02-01

    Results are presented of laboratory experiments using Union's soluble oil flood process in El Dorado cores. The core flood is to provide complete information on fluid compositions and phase behavior of the effluents such that adequate core flood match using the chemical flood simulator can be made. This step is essential for evaluating reservoir performance on the South Pattern of the El Dorado Micellar-Polymer Project. The results show the caustic preflush in the flood process causes face plugging of the field cores. The problem was controlled by using chelating agents along with the caustic fluid to keep divalent cations in solution. The required amount of chelating agent was determined to be ca 25 times as strong as the original design for the field test. Liquid chromatography analysis of sulfonate provides valuable information on selective fractionation of monosulfonate in the micellar fluid. 10 references.

  14. Fluid Mechanics

    NASA Astrophysics Data System (ADS)

    Pnueli, David; Gutfinger, Chaim

    1997-01-01

    This text is intended for the study of fluid mechanics at an intermediate level. The presentation starts with basic concepts, in order to form a sound conceptual structure that can support engineering applications and encourage further learning. The presentation is exact, incorporating both the mathematics involved and the physics needed to understand the various phenomena in fluid mechanics. Where a didactical choice must be made between the two, the physics prevails. Throughout the book the authors have tried to reach a balance between exact presentation, intuitive grasp of new ideas, and creative applications of concepts. This approach is reflected in the examples presented in the text and in the exercises given at the end of each chapter. Subjects treated are hydrostatics, viscous flow, similitude and order of magnitude, creeping flow, potential flow, boundary layer flow, turbulent flow, compressible flow, and non-Newtonian flows. This book is ideal for advanced undergraduate students in mechanical, chemical, aerospace, and civil engineering. Solutions manual available.

  15. Thermodynamic modeling for solubility prediction of indomethacin in self-nanoemulsifying drug delivery system (SNEDDS) and its individual components.

    PubMed

    Shakeel, Faiyaz; Haq, Nazrul; Alanazi, Fars K; Alsarra, Ibrahim A

    2014-09-01

    Abstract For the development of an effective self-nanoemulsifying drug delivery system (SNEDDS) of poorly soluble drugs, the knowledge of the solubility in its oil phase and SNEDDS are one of the most important factors to avoid possibility of drug to get phase separated or precipitated upon dilution with gastrointestinal fluids. With this background, this study was undertaken to determine the equilibrium saturated solubility as well as mole fraction solubility of indomethacin in prepared SNEDDS and its individual components at the temperature range of 295.15 to 320.15 K. The equilibrium solubilities of indomethacin in each sample matrices were determined by an isothermal mechanical shaking method and the resulting data was analyzed by regression analysis. The experimental mole fraction solubility data of indomethacin at various temperatures was well correlated with the modified Apelblat model. The equilibrium saturated solubility as well as mole fraction solubility of indomethacin was found to be increased with increase in temperature in SNEDDS as well as in its individual components. The mole fraction solubility of indomethacin was found to be significantly higher in Tween-80 than SNEDDS, Labrafil-M1944CS and Transcutol-HP. These preliminary studies on solubility could be a useful tool for the development of an efficient and thermodynamically stable SNEDDS formulation of various poorly soluble drugs to enhance their solubility/dissolution and oral bioavailability.

  16. Predicting the Solubility Advantage of Amorphous Pharmaceuticals: A Novel Thermodynamic Approach.

    PubMed

    Paus, Raphael; Ji, Yuanhui; Vahle, Lisa; Sadowski, Gabriele

    2015-08-03

    For the solubility and bioavailability of poorly soluble active pharmaceutical ingredients (APIs) to be improved, the transformation of crystalline APIs to the amorphous state has often been shown to be advantageous. As it is often difficult to measure the solubility of amorphous APIs, the application of thermodynamic models is the method of choice for determining the solubility advantage. In this work, the temperature-dependent solubility advantage of an amorphous API versus its crystalline form was predicted for five poorly soluble APIs in water (glibenclamide, griseofulvin, hydrochlorothiazide, indomethacin, and itraconazole) based on modeling the API/solvent phase diagrams using the perturbed-chain statistical associating fluid theory (PC-SAFT). Evaluation of the performance of this approach was performed by comparing the predicted solubility advantage to experimental data and to the solubility advantage calculated by the commonly applied Gibbs-energy-difference method. For all of the systems considered, PC-SAFT predictions of the solubility advantage are significantly more accurate than the results obtained from the Gibbs-energy-difference method.

  17. The Chemical Behavior of Fluids Released during Deep Subduction Based on Fluid Inclusions

    NASA Astrophysics Data System (ADS)

    Frezzotti, M. L.; Ferrando, S.

    2014-12-01

    We present a review of current research on fluid inclusions in (HP-) UHP metamorphic rocks that, combined with existing experimental research and thermodynamic models, allow us to investigate the chemical and physical properties of fluids released during deep subduction, their solvent and element transport capacity, and the subsequent implications for the element recycling in the mantle wedge. An impressive number of fluid inclusion studies indicate three main populations of fluid inclusions in HP and UHP metamorphic rocks: i) aqueous and/or non-polar gaseous fluid inclusions (FI), ii) multiphase solid inclusions (MSI), and iii) melt inclusions (MI). Chemical data from preserved fluid inclusions in rocks match with and implement "model" fluids by experiments and thermodynamics, revealing a continuity behind the extreme variations of physico-chemical properties of subduction-zone fluids. From fore-arc to sub-arc depths, fluids released by progressive devolatilization reactions from slab lithologies change from relatively diluted chloride-bearing aqueous solutions (± N2), mainly influenced by halide ligands, to (alkali) aluminosilicate-rich aqueous fluids, in which polymerization probably governs the solubility and transport of major (e.g., Si and Al) and trace elements (including C). Fluid inclusion data implement the petrological models explaining deep volatile liberation in subduction zones, and their flux into the mantle wedge.

  18. Solubility Classification of Airborne Uranium Products from LWR-Fuel Plants

    SciTech Connect

    kalkwarf, D. R.

    1980-08-01

    Airborne dust samples were obtained from various locations within plants manufacturing fuel elements for light-water reactors, and the dissolution rates of uranium from these samples into simulated lung fluid at 37°C were measured. These measurements were used to classify the solubilities of the samples in terms of the lung clearance model proposed by the International Commission on Radiological Protection. Similar evaluations were performed for samples of pure uranium compounds expected as components in plant dust. The variation in solubility classifications of dust encountered along the fuel production lines is described and correlated with the process chemistry and the solubility classifications of the pure uranium compounds.

  19. Fabricating neuromast-inspired gel structures for membrane-based hair cell sensing

    NASA Astrophysics Data System (ADS)

    Tamaddoni, Nima J.; Stephens, Christopher P.; Sarles, S. A.

    2012-04-01

    Recent research has shown that a new class of mechanical sensor, assembled from biomolecules and which features an artificial cell membrane as the sensing element, can be used to mimic basic hair cell mechanotransduction in vertebrates. The work presented in this paper is motivated by the need to increase sensor performance and stability by refining the methods used to fabricate and connect lipid-encapsulated hydrogels. Inspired by superficial neuromasts found on fish, three hydrogel materials are compared for their ability to be readily shaped into neuromast-inspired geometries and enable lipid bilayer formation using self-assembly at an oil/water interface. Agarose, polyethylene glycol (PEG, 6kg/mole), and hydroxyethyl methacrylate (HEMA) gel materials are compared. The results of this initial study determined that UV-curable gel materials such as PEG and HEMA enable more accurate shaping of the gel-needed for developing a sensor that uses a gel material both for mechanical support and membrane formation-compared to agarose. However, the lower hydrophobicity of agarose and PEG materials provide a more fluid, water-like environment for membrane formation-unlike HEMA. In working toward a neuromast-inspired design, a final experiment demonstrates that a bilayer can also be formed directly between two lipid-covered PEG surfaces. These initial results suggest that candidate gel materials with a low hydrophobicity, high fluidity, and a low modulus can be used to provide membrane support.

  20. The Solubility Rules: Why Are All Acetates Soluble?

    NASA Astrophysics Data System (ADS)

    van der Sluys, William G.

    2001-01-01

    According to the solubility rules presented in many introductory chemistry texts, all (or most) acetate salts are soluble in aqueous solution. The thermodynamic factors that contribute to the solubility of acetates are compared with those of other slightly basic anions. In particular, the hydration enthalpy of acetate is calculated using the Born-Haber approach, from lattice energies, heats of solution, and the hydration energies of several cations. The hydration enthalpy of acetate (-375 kJ/mol) is similar to that of chloride ({355 kJ/mol), nitrite ({383 kJ/mol), and nitrate ({370 kJ/mol), which are all considerably less exothermic than fluoride ({497 kJ/mol). This was somewhat unexpected, since hydration enthalpies generally correlate well with the acid-base properties of an ion, and acetate is more basic than fluoride. Factors influencing the solubility and acid-base properties of acetates, such as the electron donating and hydrophobic nature of the methyl group, are discussed in light of the thermodynamic data.

  1. Preliminary considerations concerning actinide solubilities

    SciTech Connect

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  2. Aqueous treatment fluid and method of use

    SciTech Connect

    Bannister, C.E.

    1987-03-03

    This patent describes a method for injecting a fluid into a borehole containing a drilling mud, wherein the fluid is not compatible with the mud and wherein injection of the fluid is preceded by injection of a composition compatible with both the mud and the fluid. The improvement described here comprises injecting a sufficient quantity of the composition to separate the mud and the fluid, at an injection velocity which exceeds the critical velocity for the composition in the borehole at the bottom hole circulating temperature of the borehole. The composition comprises an aqueous treatment fluid which as a yield point of zero at a temperature between about 85/sup 0/ and about 160/sup 0/F. and is compatible with cement slurries and drilling muds employed in the completion and drilling of subterranean boreholes. The treatment fluid comprises: Component (A) A viscosifier which is soluble in and increases the kinematic viscosity of water at temperatures between 40/sup 0/ and about 100/sup 0/F. and which becomes substantially insoluble in the treatment fluid at a temperature between about 85/sup 0/ and about 160/sup 0/F; Component (B) A thickener which is different than Component (A) and is soluble or dispersible in and increases the kinematic viscosity of water at temperatures between about 40/sup 0/ and about 160/sup 0/F.; Component (C) A dispersant which enhances the dispersibility of Component (A) in water; Component (D) A weighting agent; and Component (E) Water; wherein the Components are present in amounts sufficient to impart a kinematic viscosity to the treatment fluid, at a temperature between about 85/sup 0/ and about 160/sup 0/F., of greater than about 0.1 and less than about 7.5 centipoise-gallons/pound.

  3. Drilling fluid

    SciTech Connect

    Russell, J.A.; Patel, B.B.

    1987-11-03

    A drilling fluid additive mixture is described consisting essentially of a sulfoalkylated tannin in admixture with a non-sulfoalkylated alkali-solubilized lignite wherein the weight ratio of the sulfoalkylated tannin to the non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1. The sulfoalkylated tannin has been sulfoalkylated with at least one -(C(R-)/sub 2/-SO/sub 3/M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.

  4. Solubility limits on radionuclide dissolution

    SciTech Connect

    Kerrisk, J.F.

    1984-12-31

    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  5. Soluble TACI and soluble BCMA as biomarkers in primary central nervous system lymphoma.

    PubMed

    Thaler, Franziska S; Laurent, Sarah A; Huber, Marion; Mulazzani, Matthias; Dreyling, Martin; Ködel, Uwe; Kümpfel, Tania; Straube, Andreas; Meinl, Edgar; von Baumgarten, Louisa

    2017-05-17

    B-cell survival is regulated through interactions of B-cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) with their receptors transmembrane activator and CAML interactor (TACI) and B-cell maturation antigen (BCMA). We evaluated the diagnostic potential of soluble TACI (sTACI) and soluble BCMA (sBCMA) in cerebrospinal fluid (CSF) and serum as biomarkers in primary CNS lymphoma (PCNSL). CSF (n=176) and serum samples (n=105) from patients with clinically or radiologically suspected PCNSL as well as from control patients were collected prospectively. Levels of sTACI and sBCMA were analysed by ELISA. Additionally, in patients with PCNSL, CSF was analysed during disease course (time of diagnosis, n=26; relapse, n=10; remission, n=14) and in two patients long-term longitudinal analysis was performed. sTACI and sBCMA are significantly increased in patients with PCNSL (sTACI, median: 445 pg/ml; sBCMA, median: 760 pg/ml) compared to control patients (sTACI, median: 0 pg/ml; sBCMA, median: 290 pg/ml). At a cut-off value of 68.4 pg/ml sTACI shows high sensitivity (87.9%) and specificity (88.3%) for the diagnosis of active PCNSL. sBCMA is less sensitive (72.7%) and specific (71.8%) (cut-off: 460 pg/ml). When both markers are combined, specificity increases, however, to the cost of a lower sensitivity. In serum, both sTACI and sBCMA are not increased in PCNSL patients. Both soluble receptors correlate with clinical course and therapy response. Our results suggest that sTACI and sBCMA in the CSF are promising new biomarkers for diagnosis and therapy monitoring in PCNSL. However, our findings need to be validated in an independent cohort.

  6. Solubility characterization of airborne uranium from a uranium recycling plant.

    PubMed

    Metzger, Robert; Cole, Leslie

    2004-07-01

    Solubility profiles of uranium dusts in a uranium recycling plant were determined by performing in vitro solubility tests on breathing zone air samples conducted in all process areas of the processing plant. The recycling plant produces high density shields, closed end tubes that are punched and formed from uranium sheet metal, and high-fired uranium oxide, which is used as a catalyst. The recycled uranium is cut and melted in a vacuum furnace, and part of the molten uranium is poured into molds for further processing. Air samples were taken in process areas under normal working conditions. The dissolution rate of the uranium in a simulant solution of extracellular airway lining fluid (Gamble's solution) was then determined over the next 28 d. Airborne uranium in the oxide section of the plant was found to be highly insoluble with 99% of the uranium having a dissolution half time in excess of 100 d. The solubility of the airborne uranium in other areas of the facility was only slightly more soluble with over 90% of the airborne uranium having dissolution half times in excess of 90 d.

  7. Supercritical fluid thermodynamics for coal processing. Final report, September 15, 1988--September 14, 1991

    SciTech Connect

    van Swol, F.; Eckert, C.A.

    1988-09-15

    The main objective of this research is to develop an equation of state that can be used to predict solubilities and tailor supercritical fluid solvents for the extraction and processing of coal. To meet this objective we have implemented a two-sided. approach. First, we expanded the database of model coal compound solubilities in higher temperature fluids, polar fluids, and fluid mixtures systems. Second, the unique solute/solute, solute/cosolvent and solute/solvent intermolecular interactions in supercritical fluid solutions were investigated using spectroscopic techniques. These results increased our understanding of the molecular phenomena that affect solubility in supercritical fluids and were significant in the development of an equation of state that accurately reflects the true molecular makeup of the solution. (VC)

  8. Microporous membrane-based liver tissue engineering for the reconstruction of three-dimensional functional liver tissues in vitro.

    PubMed

    Kasuya, Junichi; Tanishita, Kazuo

    2012-01-01

    To meet the increasing demand for liver tissue engineering, various three-dimensional (3D) liver cell culture techniques have been developed. Nevertheless, conventional liver cell culture techniques involving the suspending cells in extracellular matrix (ECM) components and the seeding of cells into 3D biodegradable scaffolds have an intrinsic shortcoming, low cell-scaffold ratios. We have developed a microporous membrane-based liver cell culture technique. Cell behaviors and tissue organization can be controlled by membrane geometry, and cell-dense thick tissues can be reconstructed by layering cells cultured on biodegradable microporous membranes. Applications extend from liver parenchymal cell monoculture to multi-cell type cultures for the reconstruction of 3D functional liver tissue. This review focuses on the expanding role for microporous membranes in liver tissue engineering, primarily from our research.

  9. Non-noble metal based electro-catalyst compositions for proton exchange membrane based water electrolysis and methods of making

    DOEpatents

    Kumta, Prashant N.; Kadakia, Karan Sandeep; Datta, Moni Kanchan; Velikokhatnyi, Oleg

    2017-02-07

    The invention provides electro-catalyst compositions for an anode electrode of a proton exchange membrane-based water electrolysis system. The compositions include a noble metal component selected from the group consisting of iridium oxide, ruthenium oxide, rhenium oxide and mixtures thereof, and a non-noble metal component selected from the group consisting of tantalum oxide, tin oxide, niobium oxide, titanium oxide, tungsten oxide, molybdenum oxide, yttrium oxide, scandium oxide, cooper oxide, zirconium oxide, nickel oxide and mixtures thereof. Further, the non-noble metal component can include a dopant. The dopant can be at least one element selected from Groups III, V, VI and VII of the Periodic Table. The compositions can be prepared using a surfactant approach or a sol gel approach. Further, the compositions are prepared using noble metal and non-noble metal precursors. Furthermore, a thin film containing the compositions can be deposited onto a substrate to form the anode electrode.

  10. Figures-of-merit of Anderson localization cavities in membrane-based periodic-on-average random templates

    NASA Astrophysics Data System (ADS)

    Boddeti, Ashwin K.; Kumar, Randhir; Mujumdar, Sushil

    2017-08-01

    Anderson localization of light is an exotic mesoscopic phenomenon sustained in disordered systems through the self-interference of multiply scattered light. The localized modes are essentially eigenfunctions of the structural disorder, and define the resonances in the system. In this paper, we report on the computed figures-of-merit of Anderson cavities in two-dimensional membrane based structures, in which the disorder is written on a periodic-on-average template. We propose a disorder parameter that better reflects the randomization of the lattice points as compared to the conventionally used percentage disorder strength. Our results investigate the viability of such cavities in applications such as random lasing and cavity quantum electrodynamics.

  11. [Membrane-based photochemical systems as models for photosynthetic cells]. Progress report, February 15, 1990--August 31, 1992

    SciTech Connect

    Hurst, J.K.

    1992-12-31

    The objectives of this research are to improve our conceptual view of the ways in which membranes and interfaces can be used to control chemical reactivity. We have focused on understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis or related photoconversion/photostorage processes. Specifically, we have sought to identify: the influence of interfaces upon charge separation/recombination reactions, pathways for transmembrane charge separation across hydrocarbon bilayer membranes, and mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. As described in this report our recent research has led to considerable clarification of the underlying reaction mechanisms.

  12. A composite membrane based on a biocompatible cellulose as a host of gel polymer electrolyte for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Xiao, S. Y.; Yang, Y. Q.; Li, M. X.; Wang, F. X.; Chang, Z.; Wu, Y. P.; Liu, X.

    2014-12-01

    A composite polymer membrane is prepared by coating poly(vinylidene fluoride) (PVDF) on the surface of a membrane based on methyl cellulose (MC) which is environmentally friendly and cheap. Its characteristics are investigated by scanning electron microscopy, FT-IR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The outer PVDF layers are porous which results in high electrolyte uptake and the lithium ion transference number is much larger than that of the pure MC. Moreover, the cell based on Li//LiFePO4 delivers high discharge capacity and good rate behavior in the range of 4.2-2.5 V when the composite membrane is used as the separator and the host of a gel polymer electrolyte, lithium as the counter and reference electrode, and LiFePO4 as cathode. The obtained results suggest that this unique composite membrane shows great attraction in the lithium ion batteries with high safety and low cost.

  13. [Development and preclinical studies of insulating membranes based on poly-3-hydroxybutyrate-co-3-hydroxyvalerate for guided bone regeneration].

    PubMed

    Ivanov, S Yu; Bonartsev, A P; Gazhva, Yu V; Zharkova, I I; Mukhametshin, R F; Mahina, T K; Myshkina, V L; Bonartseva, G A; Voinova, V V; Andreeva, N V; Akulina, E A; Kharitonova, E S; Shaitan, K V; Muraev, A A

    2015-01-01

    Bone tissue damages are one of the dominant causes of temporary disability and developmental disability. Currently, there are some methods of guided bone regeneration employing different osteoplastic materials and insulation membranes used in surgery. In this study, we have developed a method of preparation of porous membranes from the biopolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), produced by a strain of Azotobacter chroococcum 7B. The biocompatibility of the porous membranes was investigated in vitro using mesenchymal stem cells (MSCs) and in vivo on laboratory animals. The cytotoxicity test showed the possibility of cell attachment on membrane and histological studies confirmed good insulating properties the material. The data obtained demonstrate the high biocompatibility and the potential application of insulating membranes based on PHBV in bone tissue engineering.

  14. A Visual Basic simulation software tool for performance analysis of a membrane-based advanced water treatment plant.

    PubMed

    Pal, P; Kumar, R; Srivastava, N; Chowdhury, J

    2014-02-01

    A Visual Basic simulation software (WATTPPA) has been developed to analyse the performance of an advanced wastewater treatment plant. This user-friendly and menu-driven software is based on the dynamic mathematical model for an industrial wastewater treatment scheme that integrates chemical, biological and membrane-based unit operations. The software-predicted results corroborate very well with the experimental findings as indicated in the overall correlation coefficient of the order of 0.99. The software permits pre-analysis and manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. It allows quick performance analysis of the whole system as well as the individual units. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for hazardous wastewater.

  15. Perfluorinated carbon-chain copolymers with functional groups and cation exchange membranes based on them: synthesis, structure and properties

    NASA Astrophysics Data System (ADS)

    Kirsh, Yu E.; Smirnov, S. A.; Popkov, Yu M.; Timashev, Sergei F.

    1990-06-01

    The review is devoted to perfluorinated polymers with sulphonic and carboxylic acid groups and to cation exchange membranes based on them. The synthesis is described of copolymers of tetrafluoroethylene with perfluorovinyl ethers containing functional groups by radical copolymerisation in an organic medium and in aqueous emulsions. Special features of the copolymerisation and approaches to obtaining copolymers with set characteristics are discussed. Data are presented on the structure and physicochemical properties of the polymeric films. Attempts to form membranes from the polymers obtained, the means of strengthening them and methods for chemical modification are described. Data are correlated on the influence of structure and polymer composition and the nature of the functional groups on the electrochemical characteristics of membranes. Special features of the functioning of perfluorinated membranes in the process for making chlorine and alkali by the electrolysis of sodium chloride solution are considered. The bibliography has 104 references.

  16. Removal of hydrogen sulfide from drilling fluids

    SciTech Connect

    Gilligan Jr., T. J.

    1985-10-22

    The present invention relates to a process for scavenging hydrogen sulfide which frequently becomes entrained in drilling fluid during the course of drilling operations through subterranean formations. The process consists of introducing a solid oxidant in powdered form into the circulating drilling fluid when hydrogen sulfide is encountered. The solid oxidants are selected from the group consisting of calcium hypochlorite (Ca-(OCl)/sub 2/), sodium perborate (NaBO/sub 3/), potassium permanganate (KMnO/sub 4/), and potassium peroxydisulfate (K/sub 2/S/sub 2/O/sub 8/). The solid oxidants are soluble in the drilling fluid, promoting fast and complete scavenging reactions without adversely altering the drilling fluid rheology.

  17. Impact of FaSSIF on the solubility and dissolution-/permeation rate of a poorly water-soluble compound.

    PubMed

    Frank, Kerstin J; Westedt, Ulrich; Rosenblatt, Karin M; Hölig, Peter; Rosenberg, Jörg; Mägerlein, Markus; Brandl, Martin; Fricker, Gert

    2012-08-30

    The poorly water-soluble drug ABT-102, a potent TRPV1 (transient receptor potential cation channel subfamily V member 1) antagonist, was investigated in terms of its solubility and dissolution-permeation rate across Caco-2 cell monolayers in the presence and absence of fasted state simulated intestinal fluid (FaSSIF). ABT-102 showed a more than 30-fold higher apparent solubility in FaSSIF, compared to Hank's balanced salt solution (HBSS). On the other hand, the amount of truly dissolved API in the suspension, as assessed by inverse dialysis, was found hardly influenced by FaSSIF. Neither the drug nor FaSSIF adversely affected cell viability or integrity of the Caco-2 monolayer. P-gp-inhibition experiments confirmed that the drug was not a substrate of the export pump. The flux of ABT-102 across the Caco-2 barrier was found virtually the same in FaSSIF and in buffer, i.e. in vitro overall dissolution-/permeation rate of ABT-102 from suspensions appears not affected by its enhanced apparent solubility due to association with TC/PC-micelles. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Solubility of sparingly soluble drug derivatives of anthranilic acid.

    PubMed

    Domańska, Urszula; Pobudkowska, Aneta; Pelczarska, Aleksandra

    2011-03-24

    This work is a continuation of our systematic study of the solubility of pharmaceuticals (Pharms). All substances here are derivatives of anthranilic acid, and have an anti-inflammatory direction of action (niflumic acid, flufenamic acid, and diclofenac sodium). The basic thermal properties of pure Pharms, i.e., melting and glass-transition temperatures as well as the enthalpy of melting, have been measured with the differential scanning microcalorimetry technique (DSC). Molar volumes have been calculated with the Barton group contribution method. The equilibrium mole fraction solubilities of three pharmaceuticals were measured in a range of temperatures from 285 to 355 K in three important solvents for Pharm investigations: water, ethanol, and 1-octanol using a dynamic method and spectroscopic UV-vis method. The experimental solubility data have been correlated by means of the commonly known G(E) equation: the NRTL, with the assumption that the systems studied here have revealed simple eutectic mixtures. pK(a) precise measurement values have been investigated with the Bates-Schwarzenbach spectrophotometric method.

  19. Gyroelastic fluids

    SciTech Connect

    Kerbel, G.D.

    1981-01-20

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

  20. Viscous fingering with partially miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, X.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Experimental and numerical studies of viscous fingering have focused on fluids that are either fully miscible (e.g. water and glycerol) or perfectly immiscible (e.g. water and oil). In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other (e.g. CO2 and water). Following our recent work for miscible systems (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a porous medium, when the two fluids have limited (but nonzero) solubility in one another. In our model, partial miscibility is characterized through the design of the thermodynamic free energy of the two-fluid system. We express the model in dimensionless form and elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution. Figure caption: final snapshots in simulations of viscous fingering with a two-fluid system mimicking that of CO2 and water. The colormap corresponds to the concentration of CO2. A band of less viscous gas phase rich in CO2 (red) displaces through the more viscous liquid phase that is undersaturated with CO2 (blue). At the fluid interface, an exchange of CO2 occurs as a result of local chemical potentials that drives the system towards thermodynamic equilibrium. This results in a shrinkage of gas phase as well as a local increase in

  1. Overexpression of Soluble Recombinant Human Lysyl Oxidase by Using Solubility Tags: Effects on Activity and Solubility

    PubMed Central

    Smith, Madison A.; Gonzalez, Jesica; Hussain, Anjum; Oldfield, Rachel N.; Johnston, Kathryn A.; Lopez, Karlo M.

    2016-01-01

    Lysyl oxidase is an important extracellular matrix enzyme that has not been fully characterized due to its low solubility. In order to circumvent the low solubility of this enzyme, three solubility tags (Nus-A, Thioredoxin (Trx), and Glutathione-S-Transferase (GST)) were engineered on the N-terminus of mature lysyl oxidase. Total enzyme yields were determined to be 1.5 mg for the Nus-A tagged enzyme (0.75 mg/L of media), 7.84 mg for the Trx tagged enzyme (3.92 mg/L of media), and 9.33 mg for the GST tagged enzyme (4.67 mg/L of media). Enzymatic activity was calculated to be 0.11 U/mg for the Nus-A tagged enzyme and 0.032 U/mg for the Trx tagged enzyme, and no enzymatic activity was detected for the GST tagged enzyme. All three solubility-tagged forms of the enzyme incorporated copper; however, the GST tagged enzyme appears to bind adventitious copper with greater affinity than the other two forms. The catalytic cofactor, lysyl tyrosyl quinone (LTQ), was determined to be 92% for the Nus-A and Trx tagged lysyl oxidase using the previously reported extinction coefficient of 15.4 mM−1 cm−1. No LTQ was detected for the GST tagged lysyl oxidase. Given these data, it appears that Nus-A is the most suitable tag for obtaining soluble and active recombinant lysyl oxidase from E. coli culture. PMID:26942005

  2. A New Simulated Plasma for Assessing the Solubility of Mineral Trioxide Aggregate

    PubMed Central

    Samiei, Mohammad; Shahi, Shahriar; Aslaminabadi, Naser; Valizadeh, Hadi; Aghazadeh, Zahra; Pakdel, Seyyed Mahdi Vahid

    2015-01-01

    Introduction: Solubility of mineral trioxide aggregate (MTA) is an important characteristic that affects other properties such as microleakage and biocompatibility. Distilled water (DW) has previously been used for solubility tests. This experimental study compared the solubility of MTA in DW, synthetic tissue fluid (STF) and new simulated plasma (SP). Methods and Materials: In this study, 36 samples of tooth-colored ProRoot MTA were prepared and divided into three groups (n=12) to be immersed in three different solutions (DW, STF, and SP). Solubility tests were conducted at 2, 5, 9, 14, 21, 30, 50, and 78-day intervals. The unequal variance F-test (Welch test) was utilized to determine the effect of solubility media and Games-Howell analysis was used for pairwise comparisons. The repeated-measures ANOVA was used to assess the importance of immersion duration. Results: Welch test showed significant differences in solubility rates of samples between all the different solubility media at all the study intervals (P<0.05) except for the 14-day interval (P=0.094). The mixed repeated-measures ANOVA revealed a significant difference in solubility rate of MTA in three different solutions at all time-intervals (P=0.000). Games-Howell post-hoc test revealed that all pairwise comparisons were statistically significant at all time-intervals (P=0.000). Conclusion: Based on the findings of this study, the long-term solubility of MTA in simulated plasma was less than that in synthetic tissue fluid and distilled water. PMID:25598806

  3. Terpolymer composition for aqueous drilling fluids

    SciTech Connect

    Giddings, D.M.; Williamson, C.D.

    1987-07-07

    A method is described of improving high temperature fluid loss and rheology stabilization of high calcium brine clay-containing aqueous oil well drilling fluids which comprises adding a stabilizing amount of a water-soluble terpolymer composition comprising: a polymer prepared by polymerizing the following monomer ingredients; the composition containing lignin, modified lignin, brown coal or modified brown coal in an amount ranging between 5-95% with the brown coal or modified brown coal having been presented during the polymerization of the water-soluble polymer. The lignin, modified lignin, brown coal or modified brown coal is from the group consisting of lignites, sulphonated lignites, lignins, leonardites, lignosulfonates, alkali metal humic acid salts, humic acids, and sulphonated humic acids.

  4. Soluble metalloendopeptidases and neuroendocrine signaling.

    PubMed

    Shrimpton, Corie N; Smith, A Ian; Lew, Rebecca A

    2002-10-01

    Peptidases play a vital and often highly specific role in the physiological and pathological generation and termination of peptide hormone signals. The thermolysin-like family of metalloendopeptidases involved in the extracellular processing of neuroendocrine and cardiovascular peptides are of particular significance, reflecting both their specificity for particular peptide substrates and their utility as therapeutic targets. Although the functions of the membrane-bound members of this family, such as angiotensin-converting enzyme and neutral endopeptidase, are well established, a role for the predominantly soluble family members in peptide metabolism is only just emerging. This review will focus on the biochemistry, cell biology, and physiology of the soluble metalloendopeptidases EC 3.4.24.15 (thimet oligopeptidase) and EC 3.4.24.16 (neurolysin), as well as presenting evidence that both peptidases play an important role in such diverse functions as reproduction, nociception, and cardiovascular homeostasis.

  5. Tough soluble aromatic thermoplastic copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    2000-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. Alternatively, these copolyimides may be prepared by reacting 4,4'-oxydiphthalic anhydride with 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydiisocyanate. Also, the copolyimide may be prepared by reacting the corresponding tetra acid and ester precursors of 4,4'-oxydiphthalic anhydride and 3,4,3',4'-biphenyltetracarboxylic dianhydride with 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  6. Droplet evaporation on a soluble substrate

    NASA Astrophysics Data System (ADS)

    Mailleur, Alexandra; Pirat, Christophe; Colombani, Jean; CNES Collaboration

    2015-11-01

    Stains left by evaporated droplets are ubiquitous in everyday life as well as in industrial processes. Whatever the composition of the evaporating liquid (colloidal suspensions, biological fluids...), the stains are mostly constituted by a deposit at the periphery of the dried drop, similar to a coffee stain (Deegan, 1997). All these studies have been carried with non-reacting solids. In this presentation, we focus on the behavior of a pure-water droplet evaporating on a soluble substrate which is more complex, since three phenomena are strongly interacting: the dissolution of the substrate, the diffusion/convection of the dissolved species into the drop and the evaporation of the liquid. NaCl and KCl single crystals have been chosen for this experimental study as they are fast-dissolving solids. We have observed that the dissolution induces a pinning of the triple line from the beginning of the evaporation, leading to a decrease of the contact angle in time. At the end of the evaporation, a peripheral deposit is always formed, proof of an outward flow inside the drop (coffee-ring effect). The authors would like to thank the CNES for the financial support.

  7. Water-soluble magnetic nanoparticles with biologically active stabilizers

    NASA Astrophysics Data System (ADS)

    Zablotskaya, Alla; Segal, Izolda; Lukevics, Edmunds; Maiorov, Mikhail; Zablotsky, Dmitry; Blums, Elmars; Shestakova, Irina; Domracheva, Ilona

    2009-05-01

    We present the results of the interaction of iron oxide nanoparticles with some biologically active surfactants, namely, oleic acid and cytotoxic alkanolamine derivatives. Physico-chemical properties, as magnetization, magnetite concentration and particle diameter, of the prepared magnetic samples were studied. The nanoparticle size of 11 nm for toluene magnetic fluid determined by TEM is in good agreement with the data obtained by the method of magnetogranulometry. In vitro cytotoxic effect of water-soluble nanoparticles with different iron oxide:oleic acid molar ratio were revealed against human fibrosarcoma and mouse hepatoma cells. In vivo results using a sarcoma mouse model showed observable antitumor action.

  8. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

    PubMed Central

    Ng, Wy Ching; Tate, Michelle D.; Brooks, Andrew G.; Reading, Patrick C.

    2012-01-01

    Host defenses against viral infections depend on a complex interplay of innate (nonspecific) and adaptive (specific) components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV). Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease. PMID:22665991

  9. Synthesis of water soluble graphene.

    PubMed

    Si, Yongchao; Samulski, Edward T

    2008-06-01

    A facile and scalable preparation of aqueous solutions of isolated, sparingly sulfonated graphene is reported. (13)C NMR and FTIR spectra indicate that the bulk of the oxygen-containing functional groups was removed from graphene oxide. The electrical conductivity of thin evaporated films of graphene (1250 S/m) relative to similarly prepared graphite (6120 S/m) implies that an extended conjugated sp (2) network is restored in the water soluble graphene.

  10. Soluble Precursor Route to Polyanilines

    DTIC Science & Technology

    1993-01-01

    goal of producing a processible form of the conducting polymer polyaniline ( PANI ), the Phase I program concentrated on development of the synthesis of... polyaniline , on the other hand, has not only been successful in every respect, but makes other attempts towards processing PAni seem awkward and obsolete...29/92 TITLE AND SUBTITLE .... 5. FUNDING NUMBERS Soluble Precursor Route to Polyanilines 6. AUTHOR(S) - 63218C 1602 0O Dr Floyd L. Klavetter 7

  11. Water soluble graft copolymers of lignin methods of making the same and uses therefore

    SciTech Connect

    Meister, J.J.

    1991-02-05

    This paper discusses a method for recovering oil from subterranean wells. It comprises dispersing a positively-charged soluble graft copolymer of lignin with a neutralizing anion in injection water; injecting the dispersion into the subterranean formation; and moving the injection fluid through the formation as a hydraulic ram, thereby pushing the resident oil to a production well.

  12. Thermally stable drilling fluid additive comprised of a copolymer of catechol-based monomer

    SciTech Connect

    Patel, A.D.

    1986-06-17

    A water soluble polymer is described having thermal stability and exhibiting utility as an aqueous drilling fluid additive comprising: (a) a major portion of a catechol based monomer; (b) a minor portion of a dicarboxylic acid monomer.

  13. The Solubility Parameters of Ionic Liquids

    PubMed Central

    Marciniak, Andrzej

    2010-01-01

    The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated. PMID:20559495

  14. Thermophysical Properties of Fluids and Fluid Mixtures

    SciTech Connect

    Sengers, Jan V.; Anisimov, Mikhail A.

    2004-05-03

    The major goal of the project was to study the effect of critical fluctuations on the thermophysical properties and phase behavior of fluids and fluid mixtures. Long-range fluctuations appear because of the presence of critical phase transitions. A global theory of critical fluctuations was developed and applied to represent thermodynamic properties and transport properties of molecular fluids and fluid mixtures. In the second phase of the project, the theory was extended to deal with critical fluctuations in complex fluids such as polymer solutions and electrolyte solutions. The theoretical predictions have been confirmed by computer simulations and by light-scattering experiments. Fluctuations in fluids in nonequilibrium states have also been investigated.

  15. [Soluble of Metals within TSP in Shanghai].

    PubMed

    Chang, Yan; Feng, Chong; Qu, Jian-guo; Zhang, Jing

    2015-04-01

    The dissolution of metals within aerosol particles is meaningful to evaluate the bioavailability and mobility of metals. Total suspended particles (TSP) samples were collected in Shanghai. We extracted the water soluble and acid soluble (pH = 2) metals by the mini-recirculation-leach-system and measured their concentrations by the high resolution inductively coupled plasma mass spectrometry. The dissolution kinetics were rapid, the maximum solubility of metals could be reached in a few minutes. Overall, the average water-soluble concentrations were low for Co, Cr, Cd, V and Ni, median for Cu, Pb and Mn and high for Fe, Al, Zn and Mg. Combine the soluble metal concentrations with the back trajectory, the original air mass had significant impacts on water soluble metal concentrations. The water solubility and acid solubility were different for various metals, the water solubility of Fe was the lowest (2.0%), others followed an order: Al, Cr, V, Pb, Co, Ni, Cu, Cd, Mn, Mg, Zn. The metals' solubility was increased with the decrease of the solvent pH value. While the chemical speciation of metals was the internal cause of metals' solubility, the metals' ionic potential and the water solubility was negatively correlated.

  16. Magnetized drive fluids

    SciTech Connect

    Rosensweig, R.E.; Zahn, M.

    1986-04-01

    A process is described for recovering a first fluid from a porous subterranean formation which comprises injecting a displacement fluid in an effective amount to displace the first fluid, injecting a ferrofluid, applying a magnetic field containing a gradient of field intensity within the formation, driving the displacement fluid through the formation with the ferrofluid and recovering first fluid.

  17. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  18. Fluid Fantasy

    NASA Image and Video Library

    2016-10-24

    Saturn's clouds are full of raw beauty, but they also represent a playground for a branch of physics called fluid dynamics, which seeks to understand the motion of gases and liquids. Saturn's lack of a solid planetary surface (as on Earth, Mars or Venus) means that its atmosphere is free to flow around the planet essentially without obstruction. This is one factor that generates Saturn's pattern of alternating belts and zones -- one of the main features of its dynamic atmosphere. Winds in the belts blow at speeds different from those in the adjacent zones, leading to the formation of vortices along the boundaries between the two. And vigorous convection occasionally leads to storms and waves. Saturn's innermost rings are just visible at the bottom and in the upper left corner. This view is centered on clouds at 25 degrees north latitude on Saturn. The image was taken with the Cassini spacecraft wide-angle camera on July 20, 2016 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers. The view was obtained at a distance of approximately 752,000 miles (1.21 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 6 degrees. Image scale is 45 miles (72 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20503

  19. The role of fluids in HFSE fractionation

    NASA Astrophysics Data System (ADS)

    Rapp, Jennifer; Klemme, Stephan; Scherer, Erik

    2010-05-01

    High field strength elements are important geochemical indicators in many geological settings, in particular in subduction zones. The HFSE signature of arc magmas is depleted relative to MORB, and there is much debate about the cause of this. Interaction between crustal and mantle rocks, and fluids liberated during metamorphism are critical for the transport of elements within the Earth, and the generation of diverse geochemical signatures. Relative depletions in HFSE have been attributed to the immobility of Ti in crustal fluids, and hence the retention of Ti and HFSE in rutile within the subducted slab. A fundamental premise of most mass-flux calculations in fluid transport is that Ti is essentially immobile in these metamorphic systems due to its low solubility in fluid, coupled with strong retention in Ti-bearing minerals such as rutile, ilmenite and titanite. As a consequence, the ‘constant Ti' frame of reference is widely used with evaluation of metasomatism and open-system behaviour, supported by experiments that have demonstrated quite low Ti solubility in aqueous fluids [1-3]. We have performed novel experiments in saline fluids, which indicate that F (and Cl) greatly enhances the solubility of rutile, and hence increases the mobility of Ti. We will show that this has implications for the mobility of the other HFSE, which are strongly sequestered into Ti-phases such as rutile [4,5]. The experimental run products have been analysed using isotope dilution ICP-MS techniques [6,7] to estimate rutile/fluid partition coefficients which may be used to determine the relative mobility of HFSE in some potential metamorphic fluids. We will show that fluids may have a strong fractionating influence on the HFSE budget of metamorphic rocks, and may influence our interpretation of the global Nb/Ta budget. References [1] Antignano, A. and Manning, C.E. (2008) Chem. Geology 255 283-293 [2] Audetat, A. and Keppler, H. (2001) Earth Planet. Sci. Lett. 232 393-402 [3

  20. A note on the coating of an inclined plane in the presence of soluble surfactant.

    PubMed

    Edmonstone, B D; Matar, O K; Craster, R V

    2006-01-01

    We consider the flow of a thin liquid film coating an inclined plane in the presence of a soluble surfactant. A two-dimensional three-equation model is derived using lubrication theory in the rapid diffusion limit and then used to investigate the stability of the fluid height and the surfactant surface and bulk concentrations. We present solutions for an insoluble surfactant system, which are then contrasted with those obtained for a system containing a soluble surfactant; both transient growth and fully nonlinear two-dimensional simulation results are discussed. Our results indicate that the characteristics of the fingering phenomena which accompany the flow are altered by the effects of solubility. In particular, we find that these effects de-stabilise the system further over an intermediate range of surfactant solubility.

  1. Solubility and chemistry of materials encountered by beryllium mine and ore extraction workers: relation to risk.

    PubMed

    Deubner, David C; Sabey, Philip; Huang, Wenjie; Fernandez, Diego; Rudd, Abigail; Johnson, William P; Storrs, Jason; Larson, Rod

    2011-10-01

    Beryllium mine and ore extraction mill workers have low rates of beryllium sensitization and chronic beryllium disease relative to the level of beryllium exposure. The objective was to relate these rates to the solubility and composition of the mine and mill materials. Medical surveillance and exposure data were summarized. Dissolution of BeO, ore materials and beryllium hydroxide, Be(OH)(2) was measured in synthetic lung fluid. The ore materials were more soluble than BeO at pH 7.2 and similar at pH 4.5. Be(OH)(2) was more soluble than BeO at both pH. Aluminum dissolved along with beryllium from ore materials. Higher solubility of beryllium ore materials and Be(OH)(2) at pH 7.2 might shorten particle longevity in the lung. The aluminum content of the ore materials might inhibit the cellular immune response to beryllium.

  2. A Quantitative Analysis of Brain Soluble Tau and the Tau Secretion Factor.

    PubMed

    Han, Pengcheng; Serrano, Geidy; Beach, Thomas G; Caselli, Richard J; Yin, Junxiang; Zhuang, Ningning; Shi, Jiong

    2017-01-09

    Neurofibrillary tangles (NFTs) represent products of insoluble tau protein in the brains of patients with Alzheimer disease (AD). The cerebrospinal fluid (CSF) tau level is a biomarker in AD diagnosis. The soluble portion of tau protein in brain parenchyma is presumably the source for CSF tau but this has not previously been quantified. We measured CSF tau and soluble brain tau at autopsy in temporal and frontal brain tissue samples from 7 cognitive normal, 12 mild cognitively impaired, and 19 AD subjects. Based on the measured brain soluble tau, we calculated the whole brain tau load and estimated tau secretion factor. Our results suggest that the increase in NFT in AD is likely attributable to post-translational processes; the increase in CSF tau in AD patients is due to an accelerated carrier-based secretion. Moreover, cognitive dysfunction assessed by final Mini-Mental State Examination scores correlated with the secretion factor but not with the soluble tau.

  3. Importance of critical micellar concentration for the prediction of solubility enhancement in biorelevant media.

    PubMed

    Ottaviani, G; Wendelspiess, S; Alvarez-Sánchez, R

    2015-04-06

    This study evaluated if the intrinsic surface properties of compounds are related to the solubility enhancement (SE) typically observed in biorelevant media like fasted state simulated intestinal fluids (FaSSIF). The solubility of 51 chemically diverse compounds was measured in FaSSIF and in phosphate buffer and the surface activity parameters were determined. This study showed that the compound critical micellar concentration parameter (CMC) correlates strongly with the solubility enhancement (SE) observed in FaSSIF compared to phosphate buffer. Thus, the intrinsic capacity of molecules to form micelles is also a determinant for each compound's affinity to the micelles of biorelevant surfactants. CMC correlated better with SE than lipophilicity (logD), especially over the logD range typically covered by drugs (2 < logD < 4). CMC can become useful to guide drug discovery scientists to better diagnose, improve, and predict solubility in biorelevant media, thereby enhancing oral bioavailability of drug candidates.

  4. Sensitivity and directionality of lipid bilayer mechanotransduction studied using a revised, highly durable membrane-based hair cell sensor

    NASA Astrophysics Data System (ADS)

    Tamaddoni, Nima; Freeman, Eric C.; Sarles, Stephen A.

    2015-06-01

    A bioinspired, membrane-based hair cell sensor consists of a planar lipid bilayer formed between two lipid-coated water droplets that connect to an artificial hair. This assembly enables motion of the hair caused by mechanical stimuli to vibrate the bilayer and produce a capacitive current. In this work, the mechanoelectrical transduction mechanism and sensing performance is experimentally characterized for a more-durable, revised hair cell embodiment that includes a cantilevered hair rooted firmly in the surrounding solid substrate. Specifically, this study demonstrates that the revised membrane-based hair cell sensor produces higher time rates of change in capacitance (0.8-6.0 nF s-1) in response to airflow across the hair compared to the original sensor (45-60 pF s-1) that did not feature a cantilevered hair. The 10-fold to 100-fold increase in the time rate change of capacitance corresponds to greater membrane bending and, thus, higher sensing currents. Membranes in the revised sensor exhibit changes in area due to bending on the order of 0.2-2.0%, versus 0.02% for the original sensor. Experiments also reveal that the bilayer displays highest sensitivity to mechanical perturbations normal to the plane of the bilayer, a membrane can transduce hair motion at frequencies below the hair’s characteristic frequency, and bilayers formed between polymerized hydrogel volumes exhibit a higher sensing currents than those formed between liquid aqueous volumes. Finally, measurements of sensitivity (5-35 pA m-1 s-1) and minimum (4.0-0.6 m s-1) and maximum (28-13 m s-1) sensing thresholds to airflow are performed for the first time, and we observe maximum electrical power (˜65 pW) in the membrane occurs for combinations of slower airflow and higher voltage. These results highlight that along with the dimensions of the hair and the compositions of the aqueous volumes, sensing performance can be tuned with applied voltage.

  5. A COMPOSITE HOLLOW FIBER MEMBRANE-BASED PERVAPORATION PROCESS FOR SEPARATION OF VOCS FROM AQUEOUS SURFACTANT SOLUTIONS. (R825511C027)

    EPA Science Inventory

    The separation and recovery of VOCs from surfactant-containing aqueous solutions by a composite hollow fiber membrane-based pervaporation process has been studied. The process employed hydrophobic microporous polypropylene hollow fibers having a thin plasma polymerized silicon...

  6. A COMPOSITE HOLLOW FIBER MEMBRANE-BASED PERVAPORATION PROCESS FOR SEPARATION OF VOCS FROM AQUEOUS SURFACTANT SOLUTIONS. (R825511C027)

    EPA Science Inventory

    The separation and recovery of VOCs from surfactant-containing aqueous solutions by a composite hollow fiber membrane-based pervaporation process has been studied. The process employed hydrophobic microporous polypropylene hollow fibers having a thin plasma polymerized silicon...

  7. Pleural fluid culture

    MedlinePlus

    Culture - pleural fluid ... is used to get a sample of pleural fluid. The sample is sent to a laboratory and ... the chest wall into the pleural space. As fluid drains into a collection bottle, you may cough ...

  8. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  9. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  10. Experiments of CO2 Solubility in the Synthetic Brine from the Erdos Basin, China

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yu, Q.

    2015-12-01

    Solubility trapping of CO2 in saline aquifers is accepted to be the promising method in terms of carbon capture and storage (CCS). CO2 solubility at geological sequestration conditions is of great significance in evaluating the carbon capture potential of brine formation. Unfortunately, most CO2 solubility studies focus mainly on single-salt solutions, and only sparse literature exist for the data of CO2 solubility in aqueous solutions containing the mixture of K+, Na+, Ca2+ and Mg2+. To fill the research gap, an experimental investigation on the CO2 solubility in the synthetic brine is carried out. The samples were extracted through the injection wells of the Shenhua Carbon Capture and Storage project in the Erdos Basin located in northern China. The proportion of K+, Na+, Ca2+ and Mg2+ was determined by chemical analysis of the samples in the aquifers. The synthetic brine is used in this study, and the experimental process were improved to lower the risk of penetration of the supercritical fluid. Solubility data were measured over the temperature and pressure ranges of 318-348 K and 8-11 MPa. In the range studied, the average absolute deviation of CO2 solubility between literature and experimental results was 2.7%, and the maximum absolute deviation was less than 5.4%. Krichevsky-Kasarnovsky (KK) equation was established to analyze the experimental data and the effect of different ions on CO2 solubility was quantified using an optimization process. The liner fit between the CO2 solubility and mixed ion concentration is satisfied with correlation coefficient of 0.91. The proposed model and experimental data therefore possess broad adaptability to geological carbon storage. This ambiguity in the mechanism of the ion effect drives our efforts toward a better understanding of the factors controlling CO2 solubility in formation brine.

  11. Fluid sampling device

    NASA Technical Reports Server (NTRS)

    Studenick, D. K. (Inventor)

    1977-01-01

    An inlet leak is described for sampling gases, more specifically, for selectively sampling multiple fluids. This fluid sampling device includes a support frame. A plurality of fluid inlet devices extend through the support frame and each of the fluid inlet devices include a longitudinal aperture. An opening device that is responsive to a control signal selectively opens the aperture to allow fluid passage. A closing device that is responsive to another control signal selectively closes the aperture for terminating further fluid flow.

  12. Experimental and theoretical studies on physico-chemical parameters affecting the solubility of phosphogypsum.

    PubMed

    Papanicolaou, Fanos; Antoniou, Stella; Pashalidis, Ioannis

    2009-10-01

    Phosphogypsum is a waste by-product of the phosphate fertilizer industry, which is usually disposed in the environment because of its restricted use in industrial applications. Physico-chemical conditions existing in stack fluids and leachates are of major importance and determine solubility and redox stability of phosphogypsum, as well as radionuclide release from stacks to terrestrial environments. The aim of this study is to assess the effect of key parameters (e.g. ionic strength, temperature, pH) on the solubility of phosphogypsum. Phosphogypsum sampling and in-situ measurements were carried out at a coastal stack in Cyprus, solubility experiments were performed in simulated laboratory systems and thermodynamic calculations by means of MINTEQA2, an equilibrium speciation model. Generally, increasing ionic strength and temperature leads to increased phosphogypsum solubility, with the former being much more effective. The increased solubility of phosphogypsum in saline solutions is attributed solely to ionic strength effects on the activity of ionic species in solution and no solid phase transformations could be observed. The effect of pH on phosphogypsum solubility seems to be insignificant at least in a pH range between 4 and 8. Regarding uranium levels, there is a strong correlation between salinity and uranium concentration and linear correlation between phosphogypsum solubility and uranium levels in stack solutions, indicating the incorporation of uranium into the gypsum lattice and the formation of a solid solution.

  13. Wettability, water sorption and water solubility of seven silicone elastomers used for maxillofacial prostheses.

    PubMed

    Hulterström, Anna Karin; Berglund, Anders; Ruyter, I Eystein

    2008-01-01

    The wettability, water sorption and solubility of silicone elastomers used for maxillofacial prostheses were studied. The hypothesis was, that a material that has absorbed water would show an increase in the wettability and thus also the surface free energy of the material. Seven silicone elastomers, both addition- and condensation type polymers, were included. Five specimens of each material were subjected to treatment according to ISO standards 1567:1999 and 10477: 2004 for water sorption and solubility. The volumes of the specimens were measured according to Archimedes principle. The contact angle was measured with a contact angle goniometer at various stages of the sorption/solubility test. Wettability changed over the test period, but not according to theory. The addition type silicones showed little or no sorption and solubility, but two of the condensation type polymers tested had a significant sorption and solubility. This study showed that condensation type polymers may show too large volumetric changes when exposed to fluids, and therefore should no longer be used in prosthetic devices. The results of this study also suggests that it might be of interest to test sorption and solubility of materials that are to be implanted, since most of the materials had some solubility.

  14. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    DOE PAGES

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; ...

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0more » MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.« less

  15. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    SciTech Connect

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; McEwen, Jason; French, Todd

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0 MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.

  16. Alkane Soluble Transition Metal Complexes.

    DTIC Science & Technology

    1983-10-01

    Al I7 𔃼 AKANE SOLUBLE TRANSITION METAL COUP rA’(U ROYAL3 MIARY COL OF SCIENCE SHRIVENHAM (ENGLAND) DEP O CHEMISTRY AND METALLURGY F R HARTLEY OCT 83...Associate Investigator B.G. Murray Chemistry and Metallurgy Departmnt TeRylMilitary College of Science Shrlveahau ftindou1 Wiltshire, UK This work woo...Plenary lecture at the 17th International Conference on Coordination Chemistry , saw" 1376. 2. D.3. Webster, Ady. Oranometal Chbe., 1977, 15,147. 3

  17. Statistical investigation of simulated fed intestinal media composition on the equilibrium solubility of oral drugs.

    PubMed

    Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin W

    2017-03-01

    Gastrointestinal fluid is a complex milieu and it is recognised that gut drug solubility is different to that observed in simple aqueous buffers. Simulated gastrointestinal media have been developed covering fasted and fed states to facilitate in vitro prediction of gut solubility and product dissolution. However, the combination of bile salts, phospholipids, fatty acids and proteins in an aqueous buffered system creates multiple phases and drug solubility is therefore a complex interaction between these components, which may create unique environments for each API. The impact on solubility can be assessed through a statistical design of experiment (DoE) approach, to determine the influence and relationships between factors. In this paper DoE has been applied to fed simulated gastrointestinal media consisting of eight components (pH, bile salt, lecithin, sodium oleate, monoglyceride, buffer, salt and pancreatin) using a two level D-optimal design with forty-four duplicate measurements and four centre points. The equilibrium solubility of a range of poorly soluble acidic (indomethacin, ibuprofen, phenytoin, valsartan, zafirlukast), basic (aprepitant, carvedilol, tadalafil, bromocriptine) and neutral (fenofibrate, felodipine, probucol, itraconazole) drugs was investigated. Results indicate that the DoE provides equilibrium solubility values that are comparable to literature results for other simulated fed gastrointestinal media systems or human intestinal fluid samples. For acidic drugs the influence of pH predominates but other significant factors related to oleate and bile salt or interactions between them are present. For basic drugs pH, oleate and bile salt have equal significance along with interactions between pH and oleate and lecithin and oleate. Neutral drugs show diverse effects of the media components particularly with regard to oleate, bile salt, pH and lecithin but the presence of monoglyceride, pancreatin and buffer have significant but smaller effects

  18. A novel polymer inclusion membrane based method for continuous clean-up of thiocyanate from gold mine tailings water.

    PubMed

    Cho, Youngsoo; Cattrall, Robert W; Kolev, Spas D

    2018-01-05

    Thiocyanate is present in gold mine tailings waters in concentrations up to 1000mgL(-1) and this has a serious environmental impact by not allowing water reuse in the flotation of gold ore. This significantly increases the consumption of fresh water and the amount of wastewater discharged in tailings dams. At the same time thiocyanate in tailings waters often leads to groundwater contamination. A novel continuous membrane-based method for the complete clean-up of thiocyanate in concentrations as high as 1000mgL(-1) from its aqueous solutions has been developed. It employs a flat sheet polymer inclusion membrane (PIM) of composition 70wt% PVC, 20wt% Aliquat 336 and 10wt% 1-tetradecanol which separates counter-current streams of a feed thiocyanate solution and a 1M NaNO3 receiving solution. The PIM-based system has been operated continuously for 45days with 99% separation efficiency. The volume of the receiving solution has been drastically reduced by recirculating it and continuously removing thiocyanate by precipitating it with in-situ generated Cu(I). The newly developed PIM-based thiocyanate clean-up method is environmentally friendly in terms of reagent use and inexpensive with respect to both equipment and running costs. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A Nanoporous Alumina Membrane Based Electrochemical Biosensor for Histamine Determination with Biofunctionalized Magnetic Nanoparticles Concentration and Signal Amplification

    PubMed Central

    Ye, Weiwei; Xu, Yifan; Zheng, Lihao; Zhang, Yu; Yang, Mo; Sun, Peilong

    2016-01-01

    Histamine is an indicator of food quality and indispensable in the efficient functioning of various physiological systems. Rapid and sensitive determination of histamine is urgently needed in food analysis and clinical diagnostics. Traditional histamine detection methods require qualified personnel, need complex operation processes, and are time-consuming. In this study, a biofunctionalized nanoporous alumina membrane based electrochemical biosensor with magnetic nanoparticles (MNPs) concentration and signal amplification was developed for histamine determination. Nanoporous alumina membranes were modified by anti-histamine antibody and integrated into polydimethylsiloxane (PDMS) chambers. The specific antibody modified MNPs were used to concentrate histamine from samples and transferred to the antibody modified nanoporous membrane. The MNPs conjugated to histamine were captured in the nanopores via specific reaction between histamine and anti-histamine antibody, resulting in a blocking effect that was amplified by MNPs in the nanopores. The blockage signals could be measured by electrochemical impedance spectroscopy across the nanoporous alumina membrane. The sensing platform had great sensitivity and the limit of detection (LOD) reached as low as 3 nM. This biosensor could be successfully applied for histamine determination in saury that was stored in frozen conditions for different hours, presenting a potentially novel, sensitive, and specific sensing system for food quality assessment and safety support. PMID:27782087

  20. Membrane-Based Energy Efficient Dewatering of Microalgae in Biofuels Production and Recovery of Value Added Co-Products

    SciTech Connect

    Bhave, Ramesh R; Kuritz, Tanya; Powell, Lawrence E; Adcock, Kenneth Dale

    2012-01-01

    The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. We have evaluated the dewatering of Nannochloropsis sp. with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ~99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, it can be shown that an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

  1. Biopolymer-induced calcium phosphate scaling in membrane-based water treatment systems: Langmuir model films studies.

    PubMed

    Dahdal, Yara N; Oren, Yoram; Schwahn, Dietmar; Pipich, Vitaliy; Herzberg, Moshe; Ying, Wang; Kasher, Roni; Rapaport, Hanna

    2016-07-01

    Biofouling and scaling on reverse osmosis (RO) or nanofiltration (NF) membranes during desalination of secondary and tertiary effluents pose an obstacle that limits the reuse of wastewater. In this study we explored the mineral scaling induced by biopolymers originated from bacterial biofilms: bovine serum albumin (BSA), fibrinogen, lysozyme and alginic acid, as well as an extracts of extracellular polymeric substances (EPS) from bio-fouled RO membranes from wastewater treatment facility. Mineralization studies were performed on Langmuir films of the biopolymers deposited at the interface of a solution simulating RO desalination of secondary-treated wastewater effluents. All studied biopolymers and EPS induced heterogeneous mineralization of mainly calcium phosphate. Using IR spectroscopy coupled with systematic quantitative analysis of the surface pressure versus molecular-area isotherms, we determined the mineralization tendencies of the biopolymers to be in the order of: fibrinogen>lysozyme>BSA>alginic acid. The biopolymers and EPS studied here were found to be accelerators of calcium-phosphate mineralization. This study demonstrates the utilization of Langmuir surface-pressure area isotherms and a model solution in quantitatively assessing the mineralization tendencies of various molecular components of EPS in context of membrane-based water treatment systems.

  2. Membrane-based energy efficient dewatering of microalgae in biofuels production and recovery of value added co-products.

    PubMed

    Bhave, Ramesh; Kuritz, Tanya; Powell, Lawrence; Adcock, Dale

    2012-05-15

    The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. The dewatering of Nannochloropsis sp. was evaluated with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ∼99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

  3. Ion-exchange-membrane-based enzyme micro-reactor coupled online with liquid chromatography-mass spectrometry for protein analysis.

    PubMed

    Zhou, Zhigui; Yang, Youyou; Zhang, Jialing; Zhang, Zhengxiang; Bai, Yu; Liao, Yiping; Liu, Huwei

    2012-04-01

    In this article, we developed a membrane-based enzyme micro-reactor by directly using commercial polystyrene-divinylbenzene cation-exchange membrane as the support for trypsin immobilization via electrostatic and hydrophobic interactions and successfully applied it for protein digestion. The construction of the reactor can be simply achieved by continuously pumping trypsin solution through the reactor for only 2 min, which was much faster than the other enzyme immobilization methods. In addition, the membrane reactor could be rapidly regenerated within 35 min, resulting in a "new" reactor for the digestion of every protein sample, completely eliminating the cross-interference of different protein samples. The amount and the activity of immobilized trypsin were measured, and the repeatability of the reactor was tested, with an RSD of 3.2% for the sequence coverage of cytochrome c in ten digestion replicates. An integrated platform for protein analysis, including online protein digestion and peptide separation and detection, was established by coupling the membrane enzyme reactor with liquid chromatography-quadrupole time-of-flight mass spectrometry. The performance of the platform was evaluated using cytochrome c, myoglobin, and bovine serum albumin, showing that even in the short digestion time of several seconds the obtained sequence coverages was comparable to or higher than that with in-solution digestion. The system was also successfully used for the analysis of proteins from yeast cell lysate.

  4. The roles of bacteriophages in membrane-based water and wastewater treatment processes: A review.

    PubMed

    Wu, Bing; Wang, Rong; Fane, Anthony G

    2017-03-01

    Membrane filtration processes have been widely applied in water and wastewater treatment for many decades. Concerns related to membrane treatment effectiveness, membrane lifespan, and membrane fouling control have been paid great attention. To achieve sustainable membrane operation with regards to low energy and maintenance cost, monitoring membrane performance and applying suitable membrane control strategies are required. As the most abundant species in water and wastewater, bacteriophages have shown great potential to be employed in membrane processes as (1) indicators to assess membrane performance considering their similar properties to human pathogenic waterborne viruses; (2) surrogate particles to monitor membrane integrity due to their nano-sized nature; and (3) biological agents to alleviate membrane fouling because of their antimicrobial properties. This study aims to provide a comprehensive review on the roles of bacteriophages in membrane-based water and wastewater treatment processes, with focuses on their uses for membrane performance examination, membrane integrity monitoring, and membrane biofouling control. The advantages, limitations, and influencing factors for bacteriophage-based applications are reported. Finally, the challenges and prospects of bacteriophage-based applications in membrane processes for water treatment are highlighted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. [Removal of CO2 from simulated flue gas of power plants by membrane-based gas absorption processes].

    PubMed

    Yang, Ming-Fen; Fang, Meng-Xiang; Zhang, Wei-Feng; Wang, Shu-Yuan; Xu, Zhi-Kang; Luo, Zhong-Yang; Cen, Ke-Fa

    2005-07-01

    Three typical absorbents such as aqueous of aminoacetic acid potassium (AAAP), monoethanolamine (MEA) and methyldiethanolamine(MDEA) are selected to investigate the performance of CO2 separation from flue gas via membrane contactors made of hydrophobic hollow fiber polypropylene porous membrane. Impacts of absorbents, concentrations and flow rates of feeding gas and absorbent solution, cyclic loading of CO2 on the removal rate and the mass transfer velocity of CO2 are discussed. The results demonstrate that the mass transfer velocity was 7.1 mol x (m2 x s)(-1) for 1 mol x L(-1) MEA with flow rate of 0.1 m x s(-1) and flue gas with that of 0.211 m x s(-1). For 1 mol L(-1) AAAP with flow rate of 0.05 m x s(-1) and flue gas of 0.211 m x s(-1), CO2 removal rate (eta) was 93.2 % and eta was 98% for 4 mol x L(-1) AAAP under the same conditions. AAAP being absorbent, eta was higher than 90% in a wider range of concentrations of CO2. It indicates that membrane-based absorption process is a widely-applied and promising way of CO2 removal from flue gas of power plants, which not only appropriates for CO2 removal of flue gas of widely-used PF and NGCC, but also for that of flue gas of IGCC can be utilized widely in future.

  6. A Nanoporous Alumina Membrane Based Electrochemical Biosensor for Histamine Determination with Biofunctionalized Magnetic Nanoparticles Concentration and Signal Amplification.

    PubMed

    Ye, Weiwei; Xu, Yifan; Zheng, Lihao; Zhang, Yu; Yang, Mo; Sun, Peilong

    2016-10-22

    Histamine is an indicator of food quality and indispensable in the efficient functioning of various physiological systems. Rapid and sensitive determination of histamine is urgently needed in food analysis and clinical diagnostics. Traditional histamine detection methods require qualified personnel, need complex operation processes, and are time-consuming. In this study, a biofunctionalized nanoporous alumina membrane based electrochemical biosensor with magnetic nanoparticles (MNPs) concentration and signal amplification was developed for histamine determination. Nanoporous alumina membranes were modified by anti-histamine antibody and integrated into polydimethylsiloxane (PDMS) chambers. The specific antibody modified MNPs were used to concentrate histamine from samples and transferred to the antibody modified nanoporous membrane. The MNPs conjugated to histamine were captured in the nanopores via specific reaction between histamine and anti-histamine antibody, resulting in a blocking effect that was amplified by MNPs in the nanopores. The blockage signals could be measured by electrochemical impedance spectroscopy across the nanoporous alumina membrane. The sensing platform had great sensitivity and the limit of detection (LOD) reached as low as 3 nM. This biosensor could be successfully applied for histamine determination in saury that was stored in frozen conditions for different hours, presenting a potentially novel, sensitive, and specific sensing system for food quality assessment and safety support.

  7. Membrane-Based Air Composition Control for Light-Duty Diesel Vehicles: A Benefit and Cost Assessment

    SciTech Connect

    K. Stork; R. Poola

    1998-10-01

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM{sub 2.5}). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles.

  8. Porous polymer composite membrane based nanogenerator: A realization of self-powered wireless green energy source for smart electronics applications

    NASA Astrophysics Data System (ADS)

    Ghosh, Sujoy Kumar; Sinha, Tridib Kumar; Mahanty, Biswajit; Jana, Santanu; Mandal, Dipankar

    2016-11-01

    An efficient, flexible and unvaryingly porous polymer composite membrane based nanogenerator (PPCNG) without any electrical poling treatment has been realised as wireless green energy source to power up smart electronic gadgets. Owing to self-polarized piezo- and ferro-electretic phenomenon of in situ platinum nanoparticles (Pt-NPs) doped porous poly(vinylidenefluoride-co-hexafluoropropylene)-membrane, a simple, inexpensive and scalable PPCNG fabrication is highlighted. The molecular orientations of the -CH2/-CF2 dipoles that cause self-polarization phenomenon has been realized by angular dependent near edge X-ray absorption fine structure spectroscopy. The square-like hysteresis loop with giant remnant polarization, Pr ˜ 68 μC/cm2 and exceptionally high piezoelectric charge coefficient, d33 ˜ - 836 pC/N promises a best suited ferro- and piezo-electretic membrane. The PPCNG exhibits a high electrical throughput such as, ranging from 2.7 V to 23 V of open-circuit voltage (Voc) and 2.9 μA to 24.7 μA of short-circuit current (Isc) under 0.5 MPa to 4.3 MPa of imparted stress amplitude by periodic human finger motion. The harvested mechanical and subsequent electrical energy by PPCNG is shown to transfer wirelessly via visible and infrared transmitter-receiver systems, where 17% and 49% of wireless power transfer efficiency, respectively, has been realized to power up several consumer electronics.

  9. Membrane-based microarrays

    NASA Astrophysics Data System (ADS)

    Dawson, Elliott P.; Hudson, James; Steward, John; Donnell, Philip A.; Chan, Wing W.; Taylor, Richard F.

    1999-11-01

    Microarrays represent a new approach to the rapid detection and identification of analytes. Studies to date have shown that the immobilization of receptor molecules (such as DNA, oligonucleotides, antibodies, enzymes and binding proteins) onto silicon and polymeric substrates can result in arrays able to detect hundreds of analytes in a single step. The formation of the receptor/analyte complex can, itself, lead to detection, or the complex can be interrogated through the use of fluorescent, chemiluminescent or radioactive probes and ligands.

  10. In vitro solubility assays in drug discovery.

    PubMed

    Kerns, Edward H; Di, Li; Carter, Guy T

    2008-11-01

    The solubility of a compound depends on its structure and solution conditions. Structure determines the lipophilicity, hydrogen bonding, molecular volume, crystal energy and ionizability, which determine solubility. Solution conditions are affected by pH, co-solvents, additives, ionic strength, time and temperature. Many drug discovery experiments are conducted under "kinetic" solubility conditions. In drug discovery, solubility has a major impact on bioassays, formulation for in vivo dosing, and intestinal absorption. A good goal for the solubility of drug discovery compounds is >60 ug/mL. Equilibrium solubility assays can be conducted in moderate throughput, by incubating excess solid with buffer and agitating for several days, prior to filtration and HPLC quantitation. Kinetic solubility assays are performed in high throughput with shorter incubation times and high throughput analyses using plate readers. The most frequently used of these are the nephelometric assay and direct UV assay, which begin by adding a small volume of DMSO stock solution of each test compound to buffer. In nephelometry, this solution is serially diluted across a microtitre plate and undissolved particles are detected via light scattering. In direct UV, undissolved particles are separated by filtration, after which the dissolved material is quantitated using UV absorption. Equilibrium solubility is useful for preformulation. Kinetic solubility is useful for rapid compound assessment, guiding optimization via structure modification, and diagnosing bioassays. It is often useful to customize solubility experiments using conditions that answer specific research questions of drug discovery teams, such as compound selection and vehicle development for pharmacology and PK studies.

  11. Rational formulation development and in vitro assessment of SMEDDS for oral delivery of poorly water soluble drugs.

    PubMed

    Sprunk, Angela; Strachan, Clare J; Graf, Anja

    2012-08-15

    The aims of this study were to formulate a self-microemulsifying drug delivery system (SMEDDS) by a rational formulation approach using mixture experimental design and to derive general concepts that make the development of such systems more feasible. Various types of oils and surfactants were systematically combined and the phase behaviour upon dilution with simulated gastric fluid examined by construction of phase diagrams. The systems solubilising the highest amount of simulated gastric fluid in the continuous microemulsion area were selected for investigation and optimisation of drug solubility. Simvastatin was added as a poorly water-soluble, lipophilic model drug. Two different mixture experimental designs using D-optimal design were set up and used to investigate the solubility of simvastatin in the SMEDDS before and after dilution with simulated gastric fluid respectively. The solubility in each mixture region was analysed by fitting quadratic models using partial least squares analysis. The established models revealed the influence of mixture components on phase behaviour and drug solubility and gave the rationale for formulation optimisation. This study demonstrated that the development of complex self-emulsifying formulations with sufficient solubilisation capacity for poorly water-soluble drugs upon oral administration can be more feasible when using experimental design.

  12. The Solubility of Diopside in Water at 10 to 15 kbar and 650 to 900 C

    NASA Astrophysics Data System (ADS)

    Macris, C. A.; Manning, C. E.

    2005-12-01

    Subduction zone fluids play a critical role in mass transfer and mantle-wedge metasomatism, yet little is known about their composition and chemical behavior. One way to better understand these important fluids is to investigate the solubility of minerals at subduction zone conditions. The solubility of diopside in H2O was measured at 10 to 15 kbar, 650 to 900 °C using a piston-cylinder apparatus with NaCl-graphite furnaces. A single gem-quality diopside crystal was placed in an inner Pt capsule, which then was perforated to allow fluid ingress and added with H2O to an outer Pt capsule, which was then sealed. The solubility was determined by the weight loss of the diopside crystals. All charges were carefully examined by SEM for composition and textural characteristics of quench material. SEM analysis revealed that in several experiments small diopside crystals nucleated and grew in the outer capsule or on the walls of the inner capsule due to fluid convection within the charge. These experiments yielded erroneously high solubilities and were omitted from final plots and equation calculations. Diopside was found to dissolve incongruently to forsterite + dissolved species at all conditions investigated. The forsterite occurs as euhedral crystals in pits etched from the diopside grain covering less than 5% of its surface. In addition, long thin wollastonite blades and a layer of SiO2 "mud" form upon quenching of the run. Experiments at 700 °C and varying times showed that diopside plus forsterite plus fluid reached equilibrium by 12 hours. The solubility of diopside + forsterite in H2O increases with increasing pressure and temperature. At 10 kbar, solubility increases from 0.004 molal at 650 °C to 0.012 molal at 900 °C. At 800 °C and 10 to 15 kbar, solubility increases from 0.008 to 0.015 molal. These preliminary data yield the equation: log mdi+fo = -0.7539 + -2135.7/T + 0.6355P, where T is in K and P is in GPa. Because temperature enhances solubility more

  13. Fluid mechanics in fluids at rest

    NASA Astrophysics Data System (ADS)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity vv. The term “compressibility” as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci.10.1016/j.ijengsci.2012.01.006 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and

  14. Fluid mechanics in fluids at rest.

    PubMed

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  15. Method to Estimate the Dissolved Air Content in Hydraulic Fluid

    NASA Technical Reports Server (NTRS)

    Hauser, Daniel M.

    2011-01-01

    In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The current methods used to measure the dissolved air content require the fluid to be drawn from the hydraulic system, and additional offline laboratory processing time is involved. During laboratory processing, there is a potential for contamination to occur, especially when subsaturated fluid is to be analyzed. A new method measures the amount of dissolved air in hydraulic fluid through the use of a dissolved oxygen meter. The device measures the dissolved air content through an in situ, real-time process that requires no additional offline laboratory processing time. The method utilizes an instrument that measures the partial pressure of oxygen in the hydraulic fluid. By using a standardized calculation procedure that relates the oxygen partial pressure to the volume of dissolved air in solution, the dissolved air content is estimated. The technique employs luminescent quenching technology to determine the partial pressure of oxygen in the hydraulic fluid. An estimated Henry s law coefficient for oxygen and nitrogen in hydraulic fluid is calculated using a standard method to estimate the solubility of gases in lubricants. The amount of dissolved oxygen in the hydraulic fluid is estimated using the Henry s solubility coefficient and the measured partial pressure of oxygen in solution. The amount of dissolved nitrogen that is in solution is estimated by assuming that the ratio of dissolved nitrogen to dissolved oxygen is equal to the ratio of the gas solubility of nitrogen to oxygen at atmospheric pressure and temperature. The technique was performed at atmospheric pressure and room temperature. The technique could be theoretically carried out at higher pressures and elevated

  16. Influence of Physiological Gastrointestinal Surfactant Ratio on the Equilibrium Solubility of BCS Class II Drugs Investigated Using a Four Component Mixture Design.

    PubMed

    Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin W

    2017-08-22

    The absorption of poorly water-soluble drugs is influenced by the luminal gastrointestinal fluid content and composition, which control solubility. Simulated intestinal fluids have been introduced into dissolution testing including endogenous amphiphiles and digested lipids at physiological levels; however, in vivo individual variation exists in the concentrations of these components, which will alter drug absorption through an effect on solubility. The use of a factorial design of experiment and varying media by introducing different levels of bile, lecithin, and digested lipids has been previously reported, but here we investigate the solubility variation of poorly soluble drugs through more complex biorelevant amphiphile interactions. A four-component mixture design was conducted to understand the solubilization capacity and interactions of bile salt, lecithin, oleate, and monoglyceride with a constant total concentration (11.7 mM) but varying molar ratios. The equilibrium solubility of seven low solubility acidic (zafirlukast), basic (aprepitant, carvedilol), and neutral (fenofibrate, felodipine, griseofulvin, and spironolactone) drugs was investigated. Solubility results are comparable with literature values and also our own previously published design of experiment studies. Results indicate that solubilization is not a sum accumulation of individual amphiphile concentrations, but a drug specific effect through interactions of mixed amphiphile compositions with the drug. This is probably due to a combined interaction of drug characteristics; for example, lipophilicity, molecular shape, and ionization with amphiphile components, which can generate specific drug-micelle affinities. The proportion of each component can have a remarkable influence on solubility with, in some cases, the highest and lowest points close to each other. A single-point solubility measurement in a fixed composition simulated media or human intestinal fluid sample will therefore provide a

  17. pH-Dependent Solubility and Dissolution Behavior of Carvedilol--Case Example of a Weakly Basic BCS Class II Drug.

    PubMed

    Hamed, Rania; Awadallah, Areeg; Sunoqrot, Suhair; Tarawneh, Ola; Nazzal, Sami; AlBaraghthi, Tamadur; Al Sayyad, Jihan; Abbas, Aiman

    2016-04-01

    The objective of this study was to investigate the pH-dependent solubility and dissolution of weakly basic Biopharmaceutical Classification Systems (BCS) class II drugs, characterized by low solubility and high permeability, using carvedilol, a weak base with a pK a value of 7.8, as a model drug. A series of solubility and in vitro dissolution studies was carried out using media that simulate the gastric and intestinal fluids and cover the physiological pH range of the GI from 1.2 to 7.8. The effect of ionic strength, buffer capacity, and buffer species of the dissolution media on the solubility and dissolution behavior of carvedilol was also investigated. The study revealed that carvedilol exhibited a typical weak base pH-dependent solubility profile with a high solubility at low pH (545.1-2591.4 μg/mL within the pH range 1.2-5.0) and low solubility at high pH (5.8-51.9 μg/mL within the pH range 6.5-7.8). The dissolution behavior of carvedilol was consistent with the solubility results, where carvedilol release was complete (95.8-98.2% released within 60 min) in media simulating the gastric fluid (pH 1.2-5.0) and relatively low (15.9-86.2% released within 240 min) in media simulating the intestinal fluid (pH 6.5-7.8). It was found that the buffer species of the dissolution media may influence the solubility and consequently the percentage of carvedilol released by forming carvedilol salts of varying solubilities. Carvedilol solubility and dissolution decreased with increasing ionic strength, while lowering the buffer capacity resulted in a decrease in carvedilol solubility and dissolution rate.

  18. Drug Solubility: Importance and Enhancement Techniques

    PubMed Central

    Savjani, Ketan T.; Gajjar, Anuradha K.; Savjani, Jignasa K.

    2012-01-01

    Solubility, the phenomenon of dissolution of solute in solvent to give a homogenous system, is one of the important parameters to achieve desired concentration of drug in systemic circulation for desired (anticipated) pharmacological response. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. More than 40% NCEs (new chemical entities) developed in pharmaceutical industry are practically insoluble in water. Solubility is a major challenge for formulation scientist. Any drug to be absorbed must be present in the form of solution at the site of absorption. Various techniques are used for the enhancement of the solubility of poorly soluble drugs which include physical and chemical modifications of drug and other methods like particle size reduction, crystal engineering, salt formation, solid dispersion, use of surfactant, complexation, and so forth. Selection of solubility improving method depends on drug property, site of absorption, and required dosage form characteristics. PMID:22830056

  19. Principles of Fluid Management.

    PubMed

    Rewa, Oleksa; Bagshaw, Sean M

    2015-10-01

    Fluid therapy is the most common intervention received by acutely ill hospitalized patients; however, important questions on its optimal use remain. Its prescription should be patient and context specific, with clear indications and contradictions, and have the type, dose, and rate specified. Any fluid therapy, if provided inappropriately, can contribute unnecessary harm to patients. The quantitative toxicity of fluid therapy contributes to worse outcomes; this should prompt greater bedside attention to fluid prescription, fluid balance, development of avoidable complications attributable to fluid overload, and for the timely deresuscitation of patients whose clinical status and physiology allow active fluid mobilization. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.

    SciTech Connect

    Poola, R.; Stork, K.

    1998-11-09

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM2.5). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles. For nearly a decade, Argonne has been evaluating membrane-based methods to control the composition of air used in combustion. Membranes are the only practical method of modifying air composition for on-board use. The applicability of the technique depends strongly on both the technical and economic feasibility of implementing it on a vehicle. Over the past 10 years, significant technical advances have been made in the development of air-separation membranes. Researchers have developed and commercialized novel membrane materials that can efficiently separate

  1. Purification of equine IgG using membrane based enhanced hybrid bioseparation technique: a potential method for manufacturing hyperimmune antibody.

    PubMed

    Wang, Lu; Sun, Xinghua; Ghosh, Raja

    2008-02-15

    Hyperimmune equine IgG is widely used as antivenom and anti-rabies agents. This article discusses a membrane based enhanced hybrid bioseparation technique for efficient and scalable purification of equine immunoglobulin G (IgG) from horse serum. This technique is an improved version of a standard hybrid bioseparation technique developed within our group earlier for fractionation of human plasma proteins (Ghosh. 2004. J Membr Sci 237: 109-117). In the presence of a high antichaotropic salt concentration, equine IgG is selectively and reversibly captured within a stirred cell membrane module from horse serum, partly due to precipitation and microfiltration, and partly due to hydrophobic interaction based membrane adsorption, while the impurities are washed out from the device. The reversibly sequestered IgG is then released by lowering the salt concentration which favor both dissolution of the precipitated IgG and desorption of the membrane bound IgG. The enhanced hybrid bioseparation technique improves the IgG recovery from the membrane module by switching from a stirring to non-stirring mode during the IgG release phase. It also reduces membrane fouling by an appropriate pH switch. The effects of operating conditions on equine IgG capture were first systematically studied. The enhanced hybrid bioseparation technique was followed by an ultrafiltration step to remove ammonium sulfate and low molecular weight impurities. The equine IgG purity obtained under optimized conditions was 88% and its recovery was over 90%, both being significantly higher than corresponding values obtained using currently used purification techniques. (c) 2007 Wiley Periodicals, Inc.

  2. Metal Oxide Solubility and Molten Salt Corrosion.

    DTIC Science & Technology

    1982-03-29

    METAL OXIDE SOLUBILITY AND MOLTEN SALT CORROSION.(U) MAR 82 K H STERN UNCLASSI E DL R L-4772NL EL .2. MICROCOPY RESOLUTION TEST CHART NATIONAL BURALU...METAL OXIDE SOLUBILITY AND MOLTEN SALT Interim report on a continuing CORROSION NRL problem. S. PERFORMING a4. REPORT NUMlER 7. AuTtwORr) S. CONTRACT OR...EQUILIBRIA AND OXIDE SOLUTION RELATIONS IN MOLTEN SALTS ............................................. 2 IV. METHODS FOR DETERMINING SOLUBILITIES

  3. Fluid transport container

    DOEpatents

    DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.

    1995-01-01

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.

  4. Fluid transport container

    DOEpatents

    DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.

    1995-11-14

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.

  5. Rare earth element budgets in subduction-zone fluids

    NASA Astrophysics Data System (ADS)

    Tsay, A.; Zajacz, Z.; Sanchez-Valle, C.

    2012-12-01

    Subduction zone fluids play a fundamental role in the geochemical cycle of the Earth. The nature and composition of these fluids are determined by complex processes and still poorly understood. As a result of a variety of metasomatic and partial melting events, arc-related magmas display a typical trace element abundance spectrum, in which the rare earth elements' (REE) signature is an important record of petrogenetic processes. Therefore, investigating the behavior of REE in fluids at high pressure (P) and temperature (T) conditions is crucial for constraining fluid composition, as well as understanding subduction-zone processes in general. However, up to date, the experimental studies on REE solubility and speciation are limited to quite low P-T conditions (300 °C, saturated water vapor pressure) [1]. The theoretical predictions of the stability of REE complexes have been performed up to 350 °C [2] and 1000 °C, 0.5 GPa [3] by the extrapolation of thermodynamic data obtained at ambient conditions. In this study we present new experimental data on REE silicate (REE2Si2O7) solubility in aqueous quartz saturated fluids, containing various ligands, at conditions relevant for subducting slabs (600, 700, 800 °C, 2.6 GPa). The aim of the experiments was to investigate the relative effect of temperature and ligands on the solubility of REE. The experiments were conducted in an end-loaded piston-cylinder apparatus and the fluids were in situ sampled at P-T in the form of primary fluid inclusions in quartz [4]. The gold capsule was typically loaded with a chip of synthetic REE silicate (La,Nd,Gd,Dy,Er,Yb)2Si2O7, an aqueous fluid (~20 wt.%) and a piece of natural quartz. During the experiment (24-48 h) a thermal gradient along the capsule promoted intensive dissolution of quartz at the hottest part and precipitation of new quartz at the cooler part of the capsule, allowing the primary fluid inclusions to be trapped (~30-50 μm). Rubidium and cesium were added to the

  6. Saturated brine well treating fluids and additives therefore

    SciTech Connect

    Dobson, J.W. Jr.; Mondshine, A.T.; Mondshine, T.C.

    1989-04-18

    A well treating fluid is described, comprising a saturated aqueous saline solution, a water soluble particulate salt which is insoluble in the saturated aqueous saline solution, a xanthomonas gum, and an eicholorhydrin crosslinked hydroxypropyl starch wherein the concentration of the xanthomonas gum is from about 0l.5 kg/m/sup 3/ to about 5.7 kg/m/sup 3/ of the well treating fluid and the concentration of the epichlorohydrin crosslinked hyroxypropyl starch is from about 0.7 kg/cm/sup 3/ to about 42 kg/m/sup 3/ of the well treating fluid.

  7. Fetal- and uterine-specific antigens in human amniotic fluid.

    PubMed

    Sutcliffe, R G; Brock, D J; Nicholson, L V; Dunn, E

    1978-09-01

    Removal of the major maternal serum proteins from second trimester amniotic fluid by antibody affinity chromatography revealed various soluble tissue antigens, of which two were fetal-specific skin proteins and another, of alpha2-mobility, was specific to the uterus, and was therefore designated alpha-uterine protein (AUP). These proteins could not be detected in maternal serum by antibody-antigen crossed electrophoresis. The concentration of AUP in amniotic fluid reached a maximum between 10 and 20 weeks of gestation, suggesting that there is an influx of uterine protein into the amniotic fluid at this stage of pregnancy.

  8. Water-soluble hydrophobically associating polymers for improved oil recovery: A literature review

    SciTech Connect

    Taylor, K.C.; Nasr-El-Din, H.A.

    1995-11-01

    Water-soluble hydrophobically associating polymers are reviewed with particular emphasis on their application in improved oil recovery (IOR). These polymers are very similar to conventional water-soluble polymers used in IOR, except that they have a small number of hydrophobic groups incorporated into the polymer backbone. At levels of incorporation of less than 1 mol%, these hydrophobic groups can significantly change polymer performance. These polymers have potential for use in mobility control, drilling fluids and profile modification. This review includes synthesis, characterization, stability, rheology and flow in porous media of associating polymers in IOR are also examined. 100 refs., 2 tabs.

  9. Solubility of methane in water under natural conditions: a laboratory study. Final report, April 1, 1978-June 30, 1982

    SciTech Connect

    Blount, C.W.; Price, L.C.

    1982-06-01

    The solubility of methane in aqueous solutions has been determined over a broad range of temperature, pressure and salinities. The effect of dissolved carbon dioxide and ethane on methane solubility has been determined at 302{sup 0}F. Also the solubility of crude oil and water in methane has been determined over a broad range of temperatures and pressures. The solubility of methane is raised by increasing pressure and temperature (above about 170{sup 0}F). There is a solubility minimum near 170{sup 0}F at constant pressure and salinity. Ionic salts effectively salt methane out of solution at all concentrations investigated. The effect of the addition of small amounts of carbon dioxide or ethane to the gas dissolved in aqueous solutions is to enhance methane solubility compared to solutions without other gases. Higher concentrations of dissolved gases, depending upon the salinity and the gas involved, decrease aqueous methane solubility. The addition of carbon dioxide always increased total gas content even when reducing the concentration of methane. With increasing concentration of ethane in the dissolved gases the total gas content reaches a maximum and then both methane and total gas content decrease. Comparison of experimental methane solubilities with gas/water ratios, salinities, bottom hole temperatures and pressures of geopressure test wells suggests that some formation fluids may be near saturation, while many others seem to be undersaturated. Petroleum is soluble in methane. Increasing pressure increases the solubility of crude oil in methane gas. At an elevated pressure, which depends upon the temperature, oil and gas form a single fluid phase.

  10. Fluid fluxes from petrological record: links to mineral-fluid thermodynamics and implications for flow patterns

    NASA Astrophysics Data System (ADS)

    Dolejš, D.

    2012-04-01

    Fluid flow through the Earth's lithosphere is an inevitable consequence of fluid production during sediment compaction, prograde metamorphic reactions, and magmatic degassing, in settings ranging from subducting zones, continental crust underplating to shallow magma chambers. In addition, high buoyancy and low viscosity of aqueous fluid in a rock environment make flow universally viable and efficient. Fluids are not preserved in their pathways and much of their evidence including chemical composition is often retrieved from mineral mode, chemical, or isotopic variations. Several important links, advantages and artifacts arising from dimensional consistency and from correlations with mineral-fluid thermodynamics are worthy to revisit. The magnitude of fluid-rock interaction is measured by the fluid-rock ratio (mfl3 mr-3) or a time-integrated fluid flux (mfl3 mr-2). These two measures differ by mr, the characteristic distance of alteration or front propagation, parallel to the flow direction. As a consequence, the fluid-rock ratios depend on spatial relationships between flow direction, temperature- and pressure-gradient orientation, and alteration zone or vein geometry. The reservoir ratios, which are required in mass-balance or phase-equilibrium calculations, can still be unambiguously defined when the above variables are scaled to the flow direction. Gradients in mole amounts of reaction progress or mineral precipitated, n, per unit temperature or pressure are directly related to standard reaction enthalpy and volume, respectively. The effects of pressure are commonly assumed to be negligible. Systematic evaluation of mineral solubilities, however, reveals that (i) dn/dT is nearly identical for a variety of phases and from subduction to collisional geotherms but minerals dissolving into charged species exhibit higher solubilities, therefore, yield greater reaction progress and lower fluid fluxes along low-dT /dzgeotherms; (ii) during lateral (isobaric) flow, dn

  11. Filtrates & Residues: An Experiment on the Molar Solubility and Solubility Product of Barium Nitrate.

    ERIC Educational Resources Information Center

    Wruck, Betty; Reinstein, Jesse

    1989-01-01

    Provides a two hour experiment using direct gravimetric methods to determine solubility constants. Provides methodology and sample results. Discusses the effect of the common ion on the solubility constant. (MVL)

  12. Filtrates & Residues: An Experiment on the Molar Solubility and Solubility Product of Barium Nitrate.

    ERIC Educational Resources Information Center

    Wruck, Betty; Reinstein, Jesse

    1989-01-01

    Provides a two hour experiment using direct gravimetric methods to determine solubility constants. Provides methodology and sample results. Discusses the effect of the common ion on the solubility constant. (MVL)

  13. Diamond Synthesis and Carbon Solubility in a Hydrous Granitoid System

    NASA Astrophysics Data System (ADS)

    Renfro, A.; Dobrzhinetskaya, L. P.

    2004-12-01

    An increasing number of UHP metamorphic terranes incorporated in collisional orogenic belts have been identified since the first discovery of diamonds within felsic metamorphic rocks of Kokchetav massif, Kazakhstan, extending up to ˜4000 km in length in the Dabie-SuLu-Qinling belt of China. Some have suggested that all orogenic belt diamonds formed from a carbonate or calc-alkaline melt similar to those derived from kimberlitic pipes, or alternatively that they formed from a carbon-enriched silicate melt with a granitoid bulk chemistry composition. Another group has suggested that orogenic belt diamonds crystallized from a COH-rich supercritical fluid. While the diversity of the minor components accompanying the SiO2-dominated inclusions from Kokchetav diamonds, as well as the presence of cavities bearing traces of a former fluid, suggest the idea of diamond growth from a COH fluid, a Si-rich melt as a source for diamond formation cannot be ruled out. Although many experiments were performed on diamond synthesis and on the petrology of diamond-bearing rocks, no consensus has been reached as to which of the mentioned growth media is correct to explain orogenic belt diamond formation. We report here the results of an experimental program undertaken to determine the critical point of the Si-Al-K-C-H2O system (and thus, to distinguish a melt environment from a fluid one) and to provide an understanding of how diamond is crystallized in hydrous subducted felsic continental crust. Carbon solubility in these systems was qualitatively determined based on the observed diamond growth rates. Experiments were performed at in a Walker-style multianvil apparatus at P=7 GPa and T=1500-1700° C with SiO2 ranging from 90 wt. %, imitating diamondiferous quartzite, to 62 wt. %, imitating a wide range of feldspathic diamondiferous gneisses. An additional parameter, oxygen fugacity, was also varied to test its affects on the solubility of carbon in Si-rich melt/fluid.

  14. Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix†

    PubMed Central

    Nelson, Andrew W.; Johns, Adam J.; Eitrheim, Eric S.; Knight, Andrew W.; Basile, Madeline; Bettis, E. Arthur; Schultz, Michael. K.; Forbes, Tori Z.

    2017-01-01

    Naturally-occurring radioactive materials (NORM) associated with unconventional drilling produced fluids from the Marcellus Shale have raised environmental concerns. However, few investigations into the fundamental chemistry of NORM in Marcellus Shale produced fluids have been performed. Thus, we performed radiochemical experiments with Marcellus Shale produced fluids to understand the partitioning behavior of major radioelements of environmental health concern (uranium (U), thorium (Th), radium (Ra), lead (Pb), and polonium (Po)). We applied a novel radiotracer, 203Pb, to understand the behavior of trace-levels of 210Pb in these fluids. Ultrafiltration experiments indicated U, Th, and Po are particle reactive in Marcellus Shale produced fluids and Ra and Pb are soluble. Sediment partitioning experiments revealed that >99% of Ra does not adsorb to sediments in the presence of Marcellus Shale produced fluids. Further experiments indicated that although Ra adsorption is related to ionic strength, the concentrations of heavier alkaline earth metals (Ba, Sr) are stronger predictors of Ra solubility. PMID:26952871

  15. Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix.

    PubMed

    Nelson, Andrew W; Johns, Adam J; Eitrheim, Eric S; Knight, Andrew W; Basile, Madeline; Bettis, E Arthur; Schultz, Michael K; Forbes, Tori Z

    2016-04-01

    Naturally-occurring radioactive materials (NORM) associated with unconventional drilling produced fluids from the Marcellus Shale have raised environmental concerns. However, few investigations into the fundamental chemistry of NORM in Marcellus Shale produced fluids have been performed. Thus, we performed radiochemical experiments with Marcellus Shale produced fluids to understand the partitioning behavior of major radioelements of environmental health concern (uranium (U), thorium (Th), radium (Ra), lead (Pb), and polonium (Po)). We applied a novel radiotracer, (203)Pb, to understand the behavior of trace-levels of (210)Pb in these fluids. Ultrafiltration experiments indicated U, Th, and Po are particle reactive in Marcellus Shale produced fluids and Ra and Pb are soluble. Sediment partitioning experiments revealed that >99% of Ra does not adsorb to sediments in the presence of Marcellus Shale produced fluids. Further experiments indicated that although Ra adsorption is related to ionic strength, the concentrations of heavier alkaline earth metals (Ba, Sr) are stronger predictors of Ra solubility.

  16. Modern fluid mechanics

    NASA Astrophysics Data System (ADS)

    Pai, S.-I.

    The properties of fluids are examined, taking into account fluids and modern fluid mechanics, the properties of liquids and gases, the properties of a plasma, the kinetic theory of fluids, the Boltzmann-Maxwellian laws of distribution, atomic and molecular structures, specific heats, enthalpy, ionization, radiation, viscosity, rheology, heat transfer, and the mixture of fluids. Statics of fluids are considered along with the fundamentals of fluid dynamics, giving attention to flow regimes, the conservation of mass, the equation of continuity, diffusion equations, the stream function, equations of motion, Kelvin's theorem, equations of motion from the Lagrangian point of view, boundary conditions, and initial conditions. Other topics discussed are related to dimensional analysis and dynamics similarity, aerothermochemistry, magnetofluid dynamics and plasma dynamics, radiation gasdynamics, rarefied gasdynamics, non-Newtonian fluids, two-phase flows, the multifluid theory of a plasma, and relativistic fluid mechanics

  17. Soluble CR1 Therapy Improves Complement Regulation in C3 Glomerulopathy

    PubMed Central

    Zhang, Yuzhou; Nester, Carla M.; Holanda, Danniele G.; Marsh, Henry C.; Hammond, Russell A.; Thomas, Lawrence J.; Meyer, Nicole C.; Hunsicker, Lawrence G.; Sethi, Sanjeev

    2013-01-01

    Dense deposit disease (DDD) and C3 glomerulonephritis (C3GN) are widely recognized subtypes of C3 glomerulopathy. These ultra-rare renal diseases are characterized by fluid-phase dysregulation of the alternative complement pathway that leads to deposition of complement proteins in the renal glomerulus. Disease triggers are unknown and because targeted treatments are lacking, progress to end stage renal failure is a common final outcome. We studied soluble CR1, a potent regulator of complement activity, to test whether it restores complement regulation in C3 glomerulopathy. In vitro studies using sera from patients with DDD showed that soluble CR1 prevents dysregulation of the alternative pathway C3 convertase, even in the presence of C3 nephritic factors. In mice deficient in complement factor H and transgenic for human CR1, soluble CR1 therapy stopped alternative pathway activation, resulting in normalization of serum C3 levels and clearance of iC3b from glomerular basement membranes. Short-term use of soluble CR1 in a pediatric patient with end stage renal failure demonstrated its safety and ability to normalize activity of the terminal complement pathway. Overall, these data indicate that soluble CR1 re-establishes regulation of the alternative complement pathway and provide support for a limited trial to evaluate soluble CR1 as a treatment for DDD and C3GN. PMID:23907509

  18. Postoperative fluid management

    PubMed Central

    Kayilioglu, Selami Ilgaz; Dinc, Tolga; Sozen, Isa; Bostanoglu, Akin; Cete, Mukerrem; Coskun, Faruk

    2015-01-01

    Postoperative care units are run by an anesthesiologist or a surgeon, or a team formed of both. Management of postoperative fluid therapy should be done considering both patients’ status and intraoperative events. Types of the fluids, amount of the fluid given and timing of the administration are the main topics that determine the fluid management strategy. The main goal of fluid resuscitation is to provide adequate tissue perfusion without harming the patient. The endothelial glycocalyx dysfunction and fluid shift to extracellular compartment should be considered wisely. Fluid management must be done based on patient’s body fluid status. Patients who are responsive to fluids can benefit from fluid resuscitation, whereas patients who are not fluid responsive are more likely to suffer complications of over-hydration. Therefore, common use of central venous pressure measurement, which is proved to be inefficient to predict fluid responsiveness, should be avoided. Goal directed strategy is the most rational approach to assess the patient and maintain optimum fluid balance. However, accessible and applicable monitoring tools for determining patient’s actual fluid need should be further studied and universalized. The debate around colloids and crystalloids should also be considered with goal directed therapies. Advantages and disadvantages of each solution must be evaluated with the patient’s specific condition. PMID:26261771

  19. Transport and relaxation processes in supercritical fluids

    NASA Astrophysics Data System (ADS)

    Jonas, J.

    Main emphasis was on design and testing of different modifications of the NMR solubility probe equipped with mixing. A new solution of the difficult problem of mixing in NMR probe at high pressure was proposed which should open new directions in supercritical fluid research. Experiments on supercritical CO2 were performed to examine collision induced scattering. The theoretical analysis of the data for SF6 and CH4 was completed, and the manuscript should be submitted for publication within the next grant period. The naphthalene/carbon dioxide solubility determination without mixing was initiated as described in the previous report. The first measurements were at 55 C and cover a range of pressures from 120 bar to 320 bar. The results are compared to the solubility data of Paulaitis, et al., and Reid, et al. Unfortunately, the data seems to be about 40% low at the higher pressures caused by diffusion of the naphthalene out of the sample cell while the equilibrium solubility is being obtained. This problem should be overcome with further sample cell design changes.

  20. Shadowgraphy of transcritical cryogenic fluids

    NASA Technical Reports Server (NTRS)

    Woodward, R. D.; Talley, D. G.; Anderson, T. J.; Winter, M.

    1994-01-01

    The future of liquid-rocket propulsion depends heavily on continued development of high pressure liquid oxygen/hydrogen systems that operate near or above the propellant critical states; however, current understanding of transcritical/supercritical injection and combustion is yet lacking. The Phillips Laboratory and the United Technologies Research Center are involved in a collaborative effort to develop diagnostics for and make detailed measurements of transcritical droplet vaporization and combustion. The present shadowgraph study of transcritical cryogenic fluids is aimed at providing insight into the behavior of liquid oxygen or cryogenic stimulants as they are injected into a supercritical environment of the same or other fluids. A detailed history of transcritical injection of liquid nitrogen into gaseous nitrogen at reduced pressures of 0.63 (subcritical) to 1.05 (supercritical) is provided. Also, critical point enhancement due to gas phase solubility and mixture effects is investigated by adding helium to the nitrogen system, which causes a distinct liquid phase to re-appear at supercritical nitrogen pressures. Liquid oxygen injection into supercritical argon or nitrogen, however, does not indicate an increase in the effective critical pressure of the system.

  1. Solubility Characteristics of PCBM and C60.

    PubMed

    Boucher, David; Howell, Jason

    2016-11-10

    Empirical data indicate that several good solvents for C60 and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have substantial polar and hydrogen-bonding components, which are not intrinsic to the structure of the C60 and PCBM molecules themselves. Functional solubility parameter (FSP) and convex solubility parameter (CSP) computations are performed on C60 and PCBM using solubility data available in the literature. The CSP and FSP results are compared to previously reported Hansen solubility parameters (HSPs) and to the parameters calculated using additive functional group contribution methods. The CSP and FSP methods confirm the anomalously large polar and hydrogen-bonding parameters, δP and δH, obtained experimentally for C60 and PCBM. This behavior, which is quite irregular given the structure of the molecules, is due to the fact that several good solvents have high δP and δH values. Thus, these irregularities are highlighted by the CSP and FSP calculations. Additional contradictory solubility characteristics are disclosed by comparing the experimental solubility parameters to a linear solvation energy relationship (LSER) model, additive functional group calculations, and COSMO-RS computations. The FSP solubility function strongly suggests that the solubility parameters do not accurately represent the cohesive energy density properties of C60 and PCBM, as intended, but rather they manifest the properties of the solvents, e.g., high δP and δH values, that are necessary to accommodate these molecules in the liquid phase.

  2. A Colorful Solubility Exercise for Organic Chemistry

    ERIC Educational Resources Information Center

    Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.

    2015-01-01

    A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…

  3. Calculation of Drug Solubilities by Pharmacy Students.

    ERIC Educational Resources Information Center

    Cates, Lindley A.

    1981-01-01

    A method of estimating the solubilities of drugs in water is reported that is based on a principle applied in quantitative structure-activity relationships. This procedure involves correlation of partition coefficient values using the octanol/water system and aqueous solubility. (Author/MLW)

  4. Airway exchange of highly soluble gases

    PubMed Central

    Powell, Frank L.; Anderson, Joseph C.

    2013-01-01

    Highly blood soluble gases exchange with the bronchial circulation in the airways. On inhalation, air absorbs highly soluble gases from the airway mucosa and equilibrates with the blood before reaching the alveoli. Highly soluble gas partial pressure is identical throughout all alveoli. At the end of exhalation the partial pressure of a highly soluble gas decreases from the alveolar level in the terminal bronchioles to the end-exhaled partial pressure at the mouth. A mathematical model simulated the airway exchange of four gases (methyl isobutyl ketone, acetone, ethanol, and propylene glycol monomethyl ether) that have high water and blood solubility. The impact of solubility on the relative distribution of airway exchange was studied. We conclude that an increase in water solubility shifts the distribution of gas exchange toward the mouth. Of the four gases studied, ethanol had the greatest decrease in partial pressure from the alveolus to the mouth at end exhalation. Single exhalation breath tests are inappropriate for estimating alveolar levels of highly soluble gases, particularly for ethanol. PMID:23305981

  5. A Colorful Solubility Exercise for Organic Chemistry

    ERIC Educational Resources Information Center

    Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.

    2015-01-01

    A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…

  6. A Membrane-Based Electro-Separation Method (MBES) for Sample Clean-Up and Norovirus Concentration

    PubMed Central

    Kang, Wei; Cannon, Jennifer L.

    2015-01-01

    Noroviruses are the leading cause of acute gastroenteritis and foodborne illnesses in the United States. Enhanced methods for detecting noroviruses in food matrices are needed as current methods are complex, labor intensive and insensitive, often resulting in inhibition of downstream molecular detection and inefficient recovery. Membrane-based electro-separation (MBES) is a technique to exchange charged particles through a size-specific dialysis membrane from one solution to another using electric current as the driving force. Norovirus has a net negative surface charge in a neutrally buffered environment, so when placed in an electric field, it moves towards the anode. It can then be separated from the cathodic compartment where the sample is placed and then collected in the anodic compartment for downstream detection. In this study, a MBES-based system was designed, developed and evaluated for concentrating and recovering murine norovirus (MNV-1) from phosphate buffer. As high as 30.8% MNV-1 migrated from the 3.5 ml sample chamber to the 1.5 ml collection chamber across a 1 μm separation membrane when 20 V was applied for 30 min using 20 mM sodium phosphate with 0.01% SDS (pH 7.5) as the electrolyte. In optimization of the method, weak applied voltage (20 V), moderate duration (30 min), and low ionic strength electrolytes with SDS addition were needed to increase virus movement efficacy. The electric field strength of the system was the key factor to enhance virus movement, which could only be improved by shortening the electrodes distance, instead of increasing system applied voltage because of virus stability. This study successfully demonstrated the norovirus mobility in an electric field and migration across a size-specific membrane barrier in sodium phosphate electrolyte. With further modification and validation in food matrixes, a novel, quick, and cost-effective sample clean-up technique might be developed to separate norovirus particles from food

  7. Light extinction method for solubility measurement

    NASA Astrophysics Data System (ADS)

    Wang, Shui; Wang, Jingkang; Yin, Qiuxiang; Wang, Yongli

    2005-03-01

    A novel measurement method for chemical solubility determination is brought forward, in which the advantages of two kinds of traditional methods are united. The results show that the concentration of unsolved particles suspending in the solution can be determined by measuring I/I0 (ratio of the transmission intensity to the incident intensity) of the laser beam permeating through the solution according to Lamben-Beer law. The biggest relative deviation for the solubility data determined is less than 1.5% for the sparingly soluble substances and 0.3% for the opulently soluble substances. By comparison of the experimental solubility data with previous data, the light extinction method is demonstrated to be stable and reliable.

  8. Effects of fluid composition on mist composition.

    PubMed

    White, Eugene M; Lucke, William E

    2003-11-01

    In a reported study, mists of selected synthetic metalworking fluids were generated in laboratory experiments by two processes, nebulization (atomization) and air sparging (bubbling). Short-chain fatty acid species were determined by in situ trimethylsilyl derivatization. Comparison of relative amounts of the short-chain acids collected from mists generated by nebulization with those generated by sparging showed that the sparged mists had significantly higher amounts of neodecanoic, nonanoic, and dodecanedioic acids. Comparison of the amounts of acids collected by the resin cartridges to amounts found on the filters showed that significant losses of octanoic and isononanoic acids occurred over 8 hours of collection and that only dodecanedioic acid was not lost from the filter over a 22-hour sampling period. In another reported metalworking mist study, contaminants of metalworking fluids, e.g., tramp oils, were shown in laboratory experiments to increase the misting potential of water-based metalworking fluids. Significantly, tramp oil contamination caused less misting in synthetic fluids than soluble and semi-synthetic fluids.

  9. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, M.; Ward, R.L.

    1991-12-24

    This patent describes a fluid sampling pump for withdrawing pressurized sample fluid from a flow line and for pumping a preselected quantity of sample fluid with each pump driving stroke from the pump to a sample vessel, the sampling pump including a pump body defining a pump bore therein having a central axis, a piston slideably moveable within the pump bore and having a fluid inlet end and an opposing operator end, a fluid sample inlet port open to sample fluid in the flow line, a fluid sample outlet port for transmitting fluid from the pump bore to the sample vessel, and a line pressure port in fluid pressure sample fluid in the flow line, an inlet valve for selectively controlling sample fluid flow from the flow line through the fluid sample inlet port, an operator unit for periodically reciprocating the piston within the pump bore, and a controller for regulating the stroke of the piston within the pump bore, and thereby the quantity of fluid pumped with each pump driving stroke. It comprises a balanced check valve seat; a balanced check valve seal; a compression member; and a central plunger.

  10. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1990-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  11. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1989-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  12. Water-soluble conductive polymers

    DOEpatents

    Aldissi, M.

    1988-02-12

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  13. Experimental and numerical determination of odorant solubility in nasal and olfactory mucosa.

    PubMed

    Kurtz, Daniel B; Zhao, Kai; Hornung, David E; Scherer, Peter

    2004-11-01

    Odorant deposition in the nasal and olfactory mucosas is dependent on a number of factors including local air/odorant flow distribution patterns, odorant mucosal solubility and odorant diffusive transport in the mucosa. Although many of these factors are difficult to measure, mucosal solubility in the bullfrog mucus has been experimentally determined for a few odorants. In the present study an experimental procedure was combined with computational fluid dynamic (CFD) techniques to further describe some of the factors that govern odorant mucosal deposition. The fraction of odorant absorbed by the nasal mucosa (eta) was experimentally determined for a number of odorants by measuring the concentration drop between odorant 'blown' into one nostril and that exiting the contralateral nostril while the subject performed a velopharyngeal closure. Odorant concentrations were measured with a photoionization detector. Odorants were delivered to the nostrils at flow rates of 3.33 and 10 l/min. The velopharyngeal closure nasal air/odorant flows were then simulated using CFD techniques in a 3-D anatomically accurate human nose modeland the mucosal odorant uptake was numerically calculated. The comparison between the numerical simulations and the experimental results lead to an estimation of the human mucosal odorant solubility and the mucosal effective diffusive transport resistance. The results of the study suggest that the increase in diffusive resistance of the mucosal layer over that of a thin layer of water seemed to be general and non-odorant-specific; however, the mucosa solubility was odorant specific and usually followed the trend that odorants with lower water solubility were more soluble in the mucosa than would be predicted from water solubility alone. The ability of this approach to model odorant movement in the nasal cavity was evaluated by comparison of the model output with known values of odorant mucosa solubility.

  14. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-01-01

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  15. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-07-06

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  16. Electric fluid pump

    DOEpatents

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  17. Pericardial fluid culture

    MedlinePlus

    ... medlineplus.gov/ency/article/003720.htm Pericardial fluid culture To use the sharing features on this page, please enable JavaScript. Pericardial fluid culture is a test performed on a sample of ...

  18. Pleural fluid smear

    MedlinePlus

    ... the fluid that has collected in the pleural space. This is the space between the lining of the outside of the ... the chest. When fluid collects in the pleural space, the condition is called pleural effusion .

  19. Peritoneal fluid analysis

    MedlinePlus

    ... at fluid that has built up in the space in the abdomen around the internal organs. This area is called the peritoneal space. ... sample of fluid is removed from the peritoneal space using a needle and syringe. Your health care ...

  20. Pericardial fluid Gram stain

    MedlinePlus

    ... staining a sample of fluid taken from the pericardium. This is the sac surrounding the heart to ... sample of fluid will be taken from the pericardium. This is done through a procedure called pericardiocentesis . ...

  1. Amniotic fluid (image)

    MedlinePlus

    Amniotic fluid surrounds the growing fetus in the womb and protects the fetus from injury and temperature changes. It ... fetal movement and permits musculoskeletal development. The amniotic fluid can be withdrawn in a procedure called amniocentsis ...

  2. Fluid sampling tool

    DOEpatents

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  3. An embedded boundary method for soluble surfactants with interface tracking for two-phase flows

    NASA Astrophysics Data System (ADS)

    Khatri, Shilpa; Tornberg, Anna-Karin

    2014-01-01

    Surfactants, surface reacting agents, lower the surface tension of the interface between fluids in multiphase flow. This capability of surfactants makes them ideal for many applications, including wetting, foaming, and dispersing. Due to their molecular composition, surfactants are adsorbed from the bulk fluid to the interface between the fluids, leading to different concentrations on the interface and in the fluid. In a previous paper [21], we introduced a new second order method using uniform grids to simulate insoluble surfactants in multiphase flow. This method used Strang splitting allowing for a fully second order treatment in time. Here, we use the same numerical methods to explicitly represent the singular interface, treat the interfacial surfactant concentration, and couple with the Navier-Stokes equations. Now, we introduce a second order method for the surfactants in the bulk that continues to allow the use of regular grids for the full problem. Difficulties arise since the boundary condition for the bulk concentration, which handles the flux of surfactant between the interface and bulk fluid, is applied at the interface which cuts arbitrarily through the regular grid. We extend the embedded boundary method, introduced in [22], to handle this challenge. Through our results, we present the effect of the solubility of the surfactants. We show results of drop dynamics due to resulting Marangoni stresses and of drop deformations in shear flow in the presence of soluble surfactants. There is a large nondimensional parameter space over which we try to understand the drop dynamics.

  4. Soluble metals in residual oil fly ash alter innate and adaptive pulmonary immune responses to bacterial infection in rats

    SciTech Connect

    Roberts, Jenny R. . E-mail: jur6@cdc.gov; Young, Shih-Houng; Castranova, Vincent; Antonini, James M.

    2007-06-15

    The soluble metals of the pollutant, residual oil fly ash (ROFA), have been shown to alter pulmonary bacterial clearance in rats. The goal of this study was to determine the potential effects on both the innate and adaptive lung immune responses after bacterial infection in rats pre-exposed to the soluble metals in ROFA. Sprague-Dawley rats were intratracheally dosed (i.t.) at day 0 with ROFA (R-Total) (1.0 mg/100 g body weight), the soluble fraction of ROFA (R-Soluble), the soluble sample subject to a chelator (R-Chelex), or phosphate-buffered saline (Saline). On day 3, rats were administered an i.t. dose of 5 x 10{sup 4} Listeria monocytogenes. On days 6, 8, and 10, bacterial pulmonary clearance was monitored and bronchoalveolar lavage (BAL) was performed on days 3 (pre-infection), 6, 8, and 10. A concentrated first fraction of lavage fluid was retained for analysis of lactate dehydrogenase and albumin to assess lung injury. BAL cell number, phenotype, and production of reactive oxygen (ROS) and nitrogen species (RNS) were assessed, and a variety of cytokines were measured in the BAL fluid. Rats pre-treated with R-Soluble showed elevated lung injury/cytotoxicity and increased cellular influx into the lungs. R-Soluble-treatment also altered ROS, RNS, and cytokine levels, and caused a degree of macrophage and T cell inhibition. These effects of R-Soluble result in increased pulmonary bacterial burden after infection. The results suggest that soluble metals in ROFA increase lung injury and inflammation, and alter both innate and adaptive pulmonary immune responses.

  5. Effects of drilling fluids on soils and plants: II. Complete drilling fluid mixtures

    SciTech Connect

    Miller, R.W.; Pesaran, P.

    1980-01-01

    Six typical drilling fluids (muds) and a drilling fluid base were mixed with six soils at ratios of 1:1 and 1:4 volumes of liquid mud/soil; these mixtures were tested for their effects on plant growth. Green beans (Phaseolus vulgaris) and sweet corn (Zea mays var. succharata (Sturtev.) Bailey) in pots in the greenhouse grew normally in a few mixtures, but in most instances plants had reduced growth when compared to those growing in soil alone (controls). It was concluded that high levels of soluble salts or the high exchangeable sodium percentages were the primary causes of reduced plant growth. The high salt content in some fluids was mostly from added potassium chloride, sodium hydroxide, and sodium dichromate. Dispersion of mud-treated soils caused by high exchangeable sodium percentages occurred in these samples because of the sodium hydroxide and sodium dichromate added to typical muds.

  6. Toward a molecular understanding of protein solubility: increased negative surface charge correlates with increased solubility.

    PubMed

    Kramer, Ryan M; Shende, Varad R; Motl, Nicole; Pace, C Nick; Scholtz, J Martin

    2012-04-18

    Protein solubility is a problem for many protein chemists, including structural biologists and developers of protein pharmaceuticals. Knowledge about how intrinsic factors influence solubility is limited due to the difficulty of obtaining quantitative solubility measurements. Solubility measurements in buffer alone are difficult to reproduce, because gels or supersaturated solutions often form, making it impossible to determine solubility values for many proteins. Protein precipitants can be used to obtain comparative solubility measurements and, in some cases, estimations of solubility in buffer alone. Protein precipitants fall into three broad classes: salts, long-chain polymers, and organic solvents. Here, we compare the use of representatives from two classes of precipitants, ammonium sulfate and polyethylene glycol 8000, by measuring the solubility of seven proteins. We find that increased negative surface charge correlates strongly with increased protein solubility and may be due to strong binding of water by the acidic amino acids. We also find that the solubility results obtained for the two different precipitants agree closely with each other, suggesting that the two precipitants probe similar properties that are relevant to solubility in buffer alone. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  7. Toward a Molecular Understanding of Protein Solubility: Increased Negative Surface Charge Correlates with Increased Solubility

    PubMed Central

    Kramer, Ryan M.; Shende, Varad R.; Motl, Nicole; Pace, C. Nick; Scholtz, J. Martin

    2012-01-01

    Protein solubility is a problem for many protein chemists, including structural biologists and developers of protein pharmaceuticals. Knowledge about how intrinsic factors influence solubility is limited due to the difficulty of obtaining quantitative solubility measurements. Solubility measurements in buffer alone are difficult to reproduce, because gels or supersaturated solutions often form, making it impossible to determine solubility values for many proteins. Protein precipitants can be used to obtain comparative solubility measurements and, in some cases, estimations of solubility in buffer alone. Protein precipitants fall into three broad classes: salts, long-chain polymers, and organic solvents. Here, we compare the use of representatives from two classes of precipitants, ammonium sulfate and polyethylene glycol 8000, by measuring the solubility of seven proteins. We find that increased negative surface charge correlates strongly with increased protein solubility and may be due to strong binding of water by the acidic amino acids. We also find that the solubility results obtained for the two different precipitants agree closely with each other, suggesting that the two precipitants probe similar properties that are relevant to solubility in buffer alone. PMID:22768947

  8. Electrochemical Characterization and Modeling of a Solid Oxide Membrane-Based Electrolyzer for Production of Magnesium and Oxygen

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Pal, Uday B.; Gopalan, Srikanth; Powell, Adam C.

    This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM-Inconel inert anode current collector for production of Mg and O2 at 1423K. The electrochemical performance of the SOM cell was evaluated by using various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scans, and potentiostatic electrolysis. The effects of Mg solubility in the flux on the current efficiency and the YSZ membrane stability during SOM electrolysis were discussed and examined through experiment and modeling. The electronic transference number of the flux were measured to assess the Mg dissolution in the flux during SOM electrolysis. A negative correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed.

  9. Drug carrier systems for solubility enhancement of BCS class II drugs: a critical review.

    PubMed

    Kumar, Sumit; Bhargava, Deepak; Thakkar, Arti; Arora, Saahil

    2013-01-01

    Poor aqueous solubility impedes a drug's bioavailability and challenges its pharmaceutical development. Pharmaceutical development of drugs with poor water solubility requires the establishment of a suitable formulation layout among various techniques. Various approaches have been investigated extensively to improve the aqueous solubility and poor dissolution rate of BCS class II and IV drugs. In this literature review, novel formulation options, particularly for class II drugs designed for applications such as micronization, self-emulsification, cyclodextrin complexation, co-crystallisation, super critical fluid technology, solubilisation by change in pH, salt formation, co-solvents, melt granulation, and solid dispersion, liposomal/niosomal formulations, are discussed in detail to introduce biopharmaceutical challenges and recent approaches to facilitate more efficient drug formulation and development.

  10. Bioavailability Improvement Strategies for Poorly Water-Soluble Drugs Based on the Supersaturation Mechanism: An Update.

    PubMed

    Yang, Meiyan; Gong, Wei; Wang, Yuli; Shan, Li; Li, Ying; Gao, Chunsheng

    2016-01-01

    The formulation development for poorly soluble drugs still remains a challenge. Supersaturating drug delivery systems (SDDS) or drug delivery systems based on supersaturating provide a promising way to improve the oral bioavailability of poorly water-soluble drugs. In supersaturable formulations, drug concentration exceeds the equilibrium solubility when exposed to gastrointestinal fluids, and the supersaturation state is maintained long enough to be absorbed, resulting in compromised bioavailability. In this article, the mechanism of generating and maintaining supersaturation and the evaluation methods of supersaturation assays are discussed. Recent advances in different drug delivery systems based on supersaturating are the focus and are discussed in detail.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  11. Solubility prediction of drugs in mixed solvents using partial solubility parameters.

    PubMed

    Jouyban, Abolghasem; Shayanfar, Ali; Panahi-Azar, Vahid; Soleymani, Jafar; Yousefi, Behrooz H; Acree, William E; York, Peter

    2011-10-01

    Solubility of drugs in binary and ternary solvent mixtures composed of water and pharmaceutical cosolvents at different temperatures were predicted using the Jouyban-Acree model and a combination of partial solubility parameters as interaction descriptors in the solution. The generally trained version of the model produced the overall mean percentage deviation values for the back-calculated solubility of drugs in binary solvents of 34.3% and the predicted solubilities in ternary solvent mixtures of 38.0%. In addition, the applicability of the trained model for predicting the solvent composition providing the maximum solubility of a drug was investigated. The results of collected solubility data of drugs in various mixed solvents and the newly measured solubility data of five drugs in ethanol + propylene glycol + water mixtures at 25°C showed that the model provided acceptable predictions and could be used in the pharmaceutical industry.

  12. Fluid force transducer

    DOEpatents

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  13. Fluid Movement and Creativity

    ERIC Educational Resources Information Center

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  14. Fluid Movement and Creativity

    ERIC Educational Resources Information Center

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  15. Solubility of Structurally Complicated Materials: II. Bone

    NASA Astrophysics Data System (ADS)

    Horvath, Ari L.

    2006-12-01

    Bone is a structurally complex material, formed of both organic and inorganic chemicals. The organic compounds constitute mostly collagen and other proteins. The inorganic or bone mineral components constitute predominantly calcium, phosphate, carbonate, and a host of minor ingredients. The mineralized bone is composed of crystals which are closely associated with a protein of which collagen is an acidic polysaccharide material. This association is very close and the protein integrates into the crystalline structure. The mineralization involves the deposition of relatively insoluble crystals on an organic framework. The solubility process takes place when the outermost ions in the crystal lattice breakaway from the surface and become separated from the crystal. This is characteristic for ions dissolving in water or aqueous solutions at the specified temperature. The magnitude of solubility is temperature and pH dependent. Bone is sparingly soluble in most solvents. Enamel is less soluble than bone and fluoroapatite is the least soluble of all apatites in acid buffers. Collagen is less soluble in neutral salt solution than in dilute acid solutions at ambient temperatures. The solubility of collagens in solvents gradually decreases with increasing age of the bone samples.

  16. Salt formation to improve drug solubility.

    PubMed

    Serajuddin, Abu T M

    2007-07-30

    Salt formation is the most common and effective method of increasing solubility and dissolution rates of acidic and basic drugs. In this article, physicochemical principles of salt solubility are presented, with special reference to the influence of pH-solubility profiles of acidic and basic drugs on salt formation and dissolution. Non-ideality of salt solubility due to self-association in solution is also discussed. Whether certain acidic or basic drugs would form salts and, if salts are formed, how easily they would dissociate back into their free acid or base forms depend on interrelationships of several factors, such as S0 (intrinsic solubility), pH, pKa, Ksp (solubility product) and pHmax (pH of maximum solubility). The interrelationships of these factors are elaborated and their influence on salt screening and the selection of optimal salt forms for development are discussed. Factors influencing salt dissolution under various pH conditions, and especially in reactive media and in presence of excess common ions, are discussed, with practical reference to the development of solid dosage forms.

  17. [Good laboratory practice of equilibrium solubility measurement].

    PubMed

    Baka, Edit

    2011-01-01

    The biggest part of my PhD work was the standardization of the classical saturation shake-flask solubility method. During the experiments we examined systematically which parameters have significant influence on the solubility value and how large experimental error (standard deviation) is caused by them in the solubility method. Hydrochlorothiazide was used as model compound. Modification in temperature, sedimentation time, composition of aqueous buffer and the technique of separation of solid and liquid phases were found to influence the equilibrium solubility results strongly. However, variations in the amount of solid excess and stirring time were found to have less influence. Based on this standardization study, we developed a new shorter (36 hours) protocol for measurements of equilibrium solubility of drug molecules. The new protocol was validated with the aid of 6 structurally different compounds. The equilibrium solubility was measured by both (standard and new) protocols. The results were in good agreement, so the shorter protocol can be applied to measure the equilibrium solubility of drug compounds.

  18. Bibliography on contaminants and solubility of organic compounds in oxygen

    NASA Technical Reports Server (NTRS)

    Ordin, P. M. (Compiler)

    1975-01-01

    A compilation of a number of document citations is presented which contains information on contaminants in oxygen. Topics covered include contaminants and solubility of organic compounds in oxygen, reaction characteristics of organic compounds with oxygen, and sampling and detection limits of impurities. Each citation in the data bank contains many items of information about the document. Some of the items are title, author, abstract, corporate source, description of figures pertinent to hazards or safety, key references, and descriptors (keywords) by which the document can be retrieved. Each citation includes an evaluation of the technical contents as to being good/excellent, acceptable, or poor. The descriptors used to define the contents of the documents and subsequently used in the computerized search operations were developed for the cryogenic fluid safety by experts in the cryogenics field.

  19. Production of soluble CD34 by human myeloid cells.

    PubMed

    Fernández, M; Simon, V; Minguell, J J

    2000-11-01

    CD34, a glycophosphoprotein present in lymphohaematopoietic stem and progenitor cells, as well as in other cell types, exists in both transmembrane and intracytoplasmic forms. Transmembrane CD34 expression, which is high in the earliest haematopoietic precursors, decreases as cells mature. However, to our knowledge, there is no information on whether a decrease in transmembrane CD34 can also predict a release of the molecule from the cell membrane into the extracellular fluid. To investigate the above possibility, we studied conditions (incubation time, cell density and proliferative status) in human myeloid cells (lines KG-1a, KG-1 and cord blood-derived cells) that may cause a decrease in surface CD34 and the generation of a soluble form of the molecule. The latter, as demonstrated by Western blot analysis, adds more complexity to the proposed structural features and functional properties of CD34 in myeloid cells.

  20. Biosorption of water-soluble dyes on magnetically modified Saccharomyces cerevisiae subsp. uvarum cells.

    PubMed

    Safaríková, M; Ptácková, L; Kibriková, I; Safarík, I

    2005-05-01

    Brewer's yeast (bottom yeast, Saccharomyces cerevisiae subsp. uvarum) cells were magnetically modified using water based magnetic fluid stabilized with perchloric acid. Magnetically modified yeast cells efficiently adsorbed various water soluble dyes. The dyes adsorption can be described by the Langmuir adsorption model. The maximum adsorption capacity of the magnetic cells differed substantially for individual dyes; the highest value was found for aniline blue (approx. 220 mg per g of dried magnetic adsorbent).

  1. Soluble for crosslinked graft copolymers of lignin based on hydroxyethylmethacrylate and acrylamide

    SciTech Connect

    Meister, J.J.

    1992-06-16

    This patent describes a method for recovering oil from subterranean wells. It comprises dispersing a soluble graft-copolymer of lignin-(2-propenamide)-(2-methyl-3-oxo-4-oxyhex-1-ene-6-ol) in injection water to form a mixture; injecting the mixture into the subterranean formation and allowing it form a foam; and moving the injection fluid through the formation as a hydraulic ram, thereby pushing the resident oil to a production well.

  2. Methodology for phase selection of a weak basic drug candidate, utilizing kinetic solubility profiles in bio-relevant media.

    PubMed

    Furukawa, Shuntaro; Zhao, Chenhua; Ohki, Yasuhiro

    2010-02-01

    We aimed to develop a phase selection methodology for a weak basic active pharmaceutical ingredient (API) that would require less than 10mg of the API and monitor the real-time kinetic solubility of the API in two bio-relevant media. Three sets of kinetic solubility measurements were conducted for free form I and the disulfate salt of an API (compound A) in order to determine the better API phase for further development of the compound. Tests consisted of solid API dissolution in both simulated gastric fluid (SGF) and fasted-state intestinal fluid (FaSSIF), and precipitation kinetics by injection of liquid state API into FaSSIF. All dissolution tests were conducted above the saturated concentrations in order to determine the compounds' thermodynamic and kinetic solubility to trace the API's phase transitions during dissolution. The pharmacokinetic profiles of compound A following oral administration of two API phases were evaluated in dogs. Results of the three sets of kinetic solubility measurements showed different kinetic solubility profiles for the two API phases under gastrointestinal conditions, indicating that the disulfate salt is preferred over free form I due to its superior kinetic solubility profile. This conclusion is consistent with the bioavailability results obtained in dogs. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  3. Absorption, utilization and clinical effectiveness of allithiamines compared to water-soluble thiamines.

    PubMed

    Baker, H; Frank, O

    1976-08-01

    Oral administration of lipid-soluble allithiamines [thiamine propyl disulfide (TPD) and thiamine tetrahydrofurfuryl disulfide (TTHF)] rapidly increased thiamine activity in whole blood, red blood cells, cerebrospinal fluid, and urine in normal and thiamine-deficient subjects. These thiamine congeners also restored red blood cell transketolase to normal in alcoholics with thiamine deficiency. Such repletion equaled that produced by parenteral, water-soluble thiamine hydrochloride (THCl) or thiamine pyrophosphate (TPP). Oral administration of water-soluble thiamines (THCl, TPP) neither elevated thiamine activity in biological fluids nor restored transketolase activity to normal in alcoholics with thiamine deficiency presumably due to their rate-limited intestinal transport. Oral administration of TPD eliminated lateral rectus palsy in patients with Wernicke's encephalopathy. Orally administered allithiamine vitamers are therefore recommended for prophylaxis and treatment of thiamine deficits because while having essentially the same biological properties as parenterally administered water-soluble thiamines they have not produced any untoward effects after long-term administration and are far more efficiently utilized.

  4. Placement in an acidic environment increase the solubility of white mineral trioxide aggregate

    PubMed Central

    Yavari, Hamid Reza; Borna, Zahra; Rahimi, Saeed; Shahi, Shahriar; Valizadeh, Hadi; Ghojazadeh, Morteza

    2013-01-01

    Aims: The aim of the present study was to evaluate solubility of white mineral trioxide aggregate (WMTA) in an acidic environment. Materials and Methods: Twenty-four metal rings were prepared, filled with WMTA and randomly divided into two groups. The samples in groups 1 and 2 were set in synthetic tissue fluid with pH values of 7.4 and 4.4, respectively and then were transferred to beakers containing synthetic tissue fluid with pH values of 7.7 and 4.4. Solubility of WMTA samples were calculated at the 9 experimental intervals. Data was analyzed with two-factor ANOVA and Bonferroni test (P < 0.03). Results: The total solubility of WMTA in groups 1 and 2 were −9.1796 ± 1.9158% and −1.1192 ± 2.6236%, (P = 0.028) with weight changes of 9.1574 ± 2.1432% and 7.3276 ± 1.5823%, respectively (P = 0.002). Statistical analysis revealed significant differences between the two groups. Conclusions: It was concluded that solubility of WMTA increases in acidic environments and additional therapeutic precautions should be taken to decrease inflammation in endodontic treatment. PMID:23833462

  5. Polymer particulates control fluid loss during well completions

    SciTech Connect

    Ali, S.A.; Nguyen, P.D.; Weaver, J.D.

    1997-05-12

    In its Gulf of Mexico operations, Chevron U.S.A. Production Co. has effectively controlled completion fluid loss to the formation by including nondamaging, soluble particulates (NSP) in the fluid. In seven Chevron wells recently completed in the Gulf of Mexico, fluid loss dropped to very low levels or zero with NSP included in the completion fluid. Conventional particulate-based, fluid-loss control methods have shown varying degrees of fluid-loss control. But these methods have the potential to cause near well bore damage and long cleanup periods. In contrast, the NSP fluid-loss additive can be cleaned up readily and causes very little decrease in formation permeability. NSP is stable enough to store and is provided as a slurry concentrate that can be dispersed easily in completion fluid. It can be pumped and mixed in the field with conventional equipment. NSP forms a barrier or filter cake that covers the surface of the formation or perforation where fluid loss is occurring.

  6. Solubility and diffusion of oxygen in phospholipid membranes.

    PubMed

    Möller, Matías N; Li, Qian; Chinnaraj, Mathivanan; Cheung, Herbert C; Lancaster, Jack R; Denicola, Ana

    2016-11-01

    The transport of oxygen and other nonelectrolytes across lipid membranes is known to depend on both diffusion and solubility in the bilayer, and to be affected by changes in the physical state and by the lipid composition, especially the content of cholesterol and unsaturated fatty acids. However, it is not known how these factors affect diffusion and solubility separately. Herein we measured the partition coefficient of oxygen in liposome membranes of dilauroyl-, dimiristoyl- and dipalmitoylphosphatidylcholine in buffer at different temperatures using the equilibrium-shift method with electrochemical detection. The apparent diffusion coefficient was measured following the fluorescence quenching of 1-pyrenedodecanoate inserted in the liposome bilayers under the same conditions. The partition coefficient varied with the temperature and the physical state of the membrane, from below 1 in the gel state to above 2.8 in the liquid-crystalline state in DMPC and DPPC membranes. The partition coefficient was directly proportional to the partial molar volume and was then associated to the increase in free-volume in the membrane as a function of temperature. The apparent diffusion coefficients were corrected by the partition coefficients and found to be nearly the same, with a null dependence on viscosity and physical state of the membrane, probably because the pyrene is disturbing the surrounding lipids and thus becoming insensitive to changes in membrane viscosity. Combining our results with those of others, it is apparent that both solubility and diffusion increase when increasing the temperature or when comparing a membrane in the gel to one in the fluid state.

  7. Reduced carbonic fluid at magmatic PT conditions: new experimental data.

    NASA Astrophysics Data System (ADS)

    Simakin, Alexander; Salova, Tamara; Rinat, Gabitov; Sergey, Isaenko

    2017-04-01

    We study properties of the dry fluid of C-O-S composition at P=2000 bar and T=900-1000oC. Dry carbonic fluid was generated at the thermal decomposition of FeCO3 and (Fe,Mg)CO3. At the decomposition of pure FeCO3 assemblages of Wus-Mt and pure Mt was recognized. Wus-Mt corresponds to the fO2 on the level around QFM-2. Native carbon was formed from the fluid when CO concentration was above constrained by CCO buffer. Generated fluid was trapped as the bubbles within welded albite glass matrix. Micro-Raman study yields around 15 vol.% of CO in the mixture with CO2. The glass trap composition was interpreted to estimate the minimum solubilities of different elements in the studied fluid: Pt - 15 ppm, Mn - 262 ppm, P - 4100 ppm, Ce -22 ppm, S- 3400 ppm, Sr - 3300 ppm (Simakin et al., 2016). We add sulfur to the system in the form of FeS2, thermally decomposing after carbonates. Fluid interaction with platinum capsule walls to form PtS leads to the fast removal of sulfur. Analysis of the interaction products provides preliminary estimate of the Pt solubility. We observe transformation of magnetite to FeS at the reaction with COS. Pyrrhotite formed from oxide contains in average 1.5 wt.% of Pt. Assuming that at the reaction 1/3Fe3O4+COS+1/3CO = FeS +CO2 all dissolved in the fluid platinum was incorporated into the sulfide we get minimum Pt solubility of about 5000 ppm. To capture fluid composition we perform experiments in the Au capsules with sodium-silicate glass trap. Micro-Raman shows that presence of water in sodium-silicate leads to the partial COS decomposition to thiols and H2S, however, COS still was prevailing form of sulfur in the fluid as predicted theoretically (Simakin, 2014). Transport of siderophile (Ni, Cr, PGE, Au), LILE (Ba, Cs, Rb, Sr), LREE and chalcophile (Ag, Zn, Cu) elements by the dry fluid of C-O-S composition can be decisive during the formation of different volcanic aerosol phases. Study was partially supported by RFBR-DFG grant # 16

  8. Oxygen solubility and permeability of carbohydrates.

    PubMed

    Whitcombe, Michael J; Parker, Roger; Ring, Stephen G

    2005-06-13

    The saturated oxygen concentration in a series of aqueous solutions of sorbitol (up to 35% w/w) and maltitol (up to 50% w/w) was measured using colorimetric reagent vials based on Rhodazine D. The results indicate that the solubility of oxygen in low-water carbohydrates is considerably lower than its solubility in pure water. It was concluded that the low-oxygen solubility is a major factor contributing to the barrier properties of low-water content carbohydrates used in the encapsulation of flavours, lipids, peptides and other oxidisable species.

  9. Simulations of solvation free energies and solubilities in supercritical solvents

    NASA Astrophysics Data System (ADS)

    Su, Zemin; Maroncelli, Mark

    2006-04-01

    Computer simulations are used to study solvation free energies and solubilities in supercritical solvents. Solvation free energies are calculated using the particle insertion method. The equilibrium solvent configurations required for these calculations are based on molecular dynamics simulations employing model solvent potentials previously tuned to reproduce liquid-vapor coexistence properties of the fluids Xe, C2H6, CO2, and CHF3. Solutes are represented by all-atom potentials based on ab initio calculations and the OPLS-AA parameter set. Without any tuning of the intermolecular potentials, such calculations are found to reproduce the solvation free energies of a variety of typical solid solutes with an average accuracy of ±2kJ /mol. Further calculations on simple model solutes are also used to explore general aspects of solvation free energies in supercritical solvents. Comparisons of solutes in Lennard-Jones and hard-sphere representations of Xe show that solvation free energies and thus solubilities are not significantly influenced by solvent density fluctuations near the critical point. The solvation enthalpy and entropy do couple to these fluctuations and diverge similarly to solute partial molar volumes. Solvation free energies are also found to be little affected by the local density augmentation characteristic of the compressible regime. In contrast to solute-solvent interaction energies, which often provide a direct measure of local solvent densities, solvation free energies are remarkably insensitive to the presence of local density augmentation.

  10. Hydrocarbon soluble polymer complexes useful as viscosifiers in fracturing operations

    SciTech Connect

    Lundberg, R.D.; Peiffer, D.G.; Sedillo, L.P.; Newlove, J.C.

    1986-04-01

    This patent describes a process for fracturing a subterranean formation surrounding a gas or oil well. This process consists of injecting into the subterranean formation under fracturing pressure a fluid comprising about 0.01 to about 25 weight percent of a polymer complex dissolved in a solvent system of a nonpolar organic liquid hydrocarbon having a solubility parameter of less then 9.5. The polymer complex consists of the interaction product of a sulfonated polymer and an amine containing polymer which is hydrocarbon soluble, wherein the sulfonated polymer is selected from the group consisting of sulfonated polystyrene, sulfonated EPDM terpolymer, sulfonated polyisoprene, sulfonated ethylene, sulfonated propylene, sulfonated ethylene/propylene copolymers, sulfonated styrene/acrylonitrile copolymers and sulfonated styrene/methyl methacrylate copolymers. The sulfonate content of the sulfonated polymer is about 4 meq. per 100 gram of polymer to about 200 meq. per 100 gram of polymer and the basic nitrogen content of the amine containing polymer is about 4 meq. per 100 gram of polymer to about 500 meq. per 100 gram of polymer. The amine containing polymer is a copolymer of vinyl pyridine with other vinyl monomers and the number average molecular weight of the amine containg polymer is about 10,000 to about 10,000,000, and the number average molecular weight of the sulfonated polymer is from 1,000 to 10,000,000. The mole ratio of the sulfonated polymer to the amine-containing polymer is about 1:15 to 15:1.

  11. Goal directed fluid therapy.

    PubMed

    Marik, Paul E; Desai, Himanshu

    2012-01-01

    The cornerstone of treating patients with shock remains as it has for decades, intravenous fluids. Surprisingly, dosing intravenous fluid during resuscitation of shock remains largely empirical. Recent data suggests that early aggressive resuscitation of critically ill patients may limit and/or reverse tissue hypoxia, progression to organ failure and improve outcome. However, overzealous fluid resuscitation has been associated with increased complications, increased length of intensive care unit (ICU) and hospital stay and increased mortality. This review focuses on methods to assess fluid responsiveness and the application of these methods for goal directed fluid therapy in critically ill and peri-operative patients.

  12. Effect of Cyclodextrin Types and Co-Solvent on Solubility of a Poorly Water Soluble Drug

    PubMed Central

    Charumanee, Suporn; Okonogi, Siriporn; Sirithunyalug, Jakkapan; Wolschann, Peter; Viernstein, Helmut

    2016-01-01

    The aim of the study was to investigate the solubility of piroxicam (Prx) depending on the inclusion complexation with various cyclodextrins (CDs) and on ethanol as a co-solvent. The phase-solubility method was applied to determine drug solubility in binary and ternary systems. The results showed that in systems consisting of the drug dissolved in ethanol–water mixtures, the drug solubility increased exponentially with a rising concentration of ethanol. The phase solubility measurements of the drug in aqueous solutions of CDs, β-CD and γ-CD exhibited diagrams of AL-type, whereas 2,6-dimethyl-β-CD revealed AP-type. The destabilizing effect of ethanol as a co-solvent was observed for all complexes regardless of the CD type, as a consequence of it the lowering of the complex formation constants. In systems with a higher concentration of ethanol, the drug solubility was increased in opposition to the decreasing complex formation constants. According to this study, the type of CDs played a more important role on the solubility of Prx, and the use of ethanol as a co-solvent exhibited no synergistic effect on the improvement of Prx solubility. The Prx solubility was increased again due to the better solubility in ethanol. PMID:27763573

  13. Fluid cooled electrical assembly

    DOEpatents

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  14. Spinning fluids reactor

    DOEpatents

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  15. Perioperative Fluid Restriction

    PubMed Central

    Bleier, Joshua I.S.; Aarons, Cary B.

    2013-01-01

    Perioperative fluid management of the colorectal surgical patient has evolved significantly over the last five decades. Older notions espousing aggressive hydration have been shown to be associated with increased complications. Newer data regarding fluid restriction has shown an association with improved outcomes. Management of perioperative fluid administration can be considered in three primary phases: In the preoperative phase, data suggests that avoidance of preoperative bowel preparation and avoidance of undue preoperative dehydration can improve outcomes. Although the type of intraoperative fluid given does not have a significant effect on outcome, data do suggest that a restrictive fluid regimen results in improved outcomes. Finally, in the postoperative phase of fluid management, a fluid-restrictive regimen, coupled with early enteral feeding also seems to result in improved outcomes. PMID:24436675

  16. Intravenous fluids: balancing solutions.

    PubMed

    Hoorn, Ewout J

    2017-08-01

    The topic of intravenous (IV) fluids may be regarded as "reverse nephrology", because nephrologists usually treat to remove fluids rather than to infuse them. However, because nephrology is deeply rooted in fluid, electrolyte, and acid-base balance, IV fluids belong in the realm of our specialty. The field of IV fluid therapy is in motion due to the increasing use of balanced crystalloids, partly fueled by the advent of new solutions. This review aims to capture these recent developments by critically evaluating the current evidence base. It will review both indications and complications of IV fluid therapy, including the characteristics of the currently available solutions. It will also cover the use of IV fluids in specific settings such as kidney transplantation and pediatrics. Finally, this review will address the pathogenesis of saline-induced hyperchloremic acidosis, its potential effect on outcomes, and the question if this should lead to a definitive switch to balanced solutions.

  17. A novel approach on fluid dispensing for a DNA/RNA extraction chip package

    NASA Astrophysics Data System (ADS)

    Xie, Ling; Premachandran, C. S.; Chew, Michelle; Yao, Qiang; Xu, Diao; Pinjala, D.

    2008-02-01

    Micro fluidic package with integrated reservoirs has been developed for DNA /RNA extraction application. A membrane based pump which consists of a reservoir to store reagents and a pin valve to control the fluid is developed to dispense the reagents into the chip. A programmable external actuator is fabricated to dispense the fluid from the membrane pump into the DNA chip. An elastic and high elongation thin rubber membrane is used to seal the membrane pump and at the same time prevent actuator from mixing with different reagents in the micro fluidic package. Break displacement during actuation of membrane pump sealing material is studied with different ratios of PDMS and other types of rubber materials. The fluid flow from the reservoir to the chip is controlled by a pin valve which is activated during the external actuation. A CFD simulation is performed to study the pumping action dusting the external actuation and is validated with experimental results.

  18. Drilling fluids with scavengers help control H[sub 2]S

    SciTech Connect

    Scott, P. )

    1994-05-23

    Maintaining a high pH and using chemical sulfide scavengers in oil-based and water-based drilling muds can neutralize hydrogen sulfide (H[sub 2]S). Safe, successful drilling of H[sub 2]S-bearing formations requires good drilling practices, extra attention to casing design, and proper drilling fluid formulation. The drilling fluid must be capable of controlling formation pressures, protecting workers, inhibiting corrosion, limiting drilling fluid contamination, maintaining well bore stability, and removing sulfide contamination rapidly. High-alkalinity drilling fluids with excess lime are recommended to provide buffering capacity for pH neutralization. Following the detection of soluble sulfides, the fluid should be immediately treated with the applicable scavenger. Sulfide scavengers must react with soluble sulfides to form an insoluble metal sulfide precipitate. Effective scavengers must have rapid and complete reactions with H[sup 2]S, HS[sup [minus

  19. Solubility of carbohydrates in heavy water.

    PubMed

    Cardoso, Marcus V C; Carvalho, Larissa V C; Sabadini, Edvaldo

    2012-05-15

    The solubility of several mono-(glucose and xylose), di-(sucrose and maltose), tri-(raffinose) and cyclic (α-cyclodextrin) saccharides in H(2)O and in D(2)O were measured over a range of temperatures. The solution enthalpies for the different carbohydrates in the two solvents were determined using the vant' Hoff equation and the values in D(2)O are presented here for the first time. Our findings indicate that the replacement of H(2)O by D(2)O remarkably decreases the solubilities of the less soluble carbohydrates, such as maltose, raffinose and α-cyclodextrin. On the other hand, the more soluble saccharides, glucose, xylose, and sucrose, are practically insensitive to the H/D replacement in water.

  20. An Introduction to the Understanding of Solubility.

    ERIC Educational Resources Information Center

    Letcher, Trevor M.; Battino, Rubin

    2001-01-01

    Explores different solubility processes and related issues, including the second law of thermodynamics and ideal mixtures, real liquids, intermolecular forces, and solids in liquids or gases in liquids. (Contains 22 references.) (ASK)