Science.gov

Sample records for high water solubility

  1. Water solubility in pyrope at high pressures

    NASA Astrophysics Data System (ADS)

    Mookherjee, M.; Karato, S.-

    2006-12-01

    To address how much water is stored within the Earth's mantle, we need to understand the water solubility in the nominally anhydrous minerals. Much is known about olivine and pyroxene. Garnet is another important component, approaching 40% by volume in the transition zone. Only two studies on water solubility in pyrope at high-pressures exist which contradict each other. Lu and Keppler (1997) observed increase in water solubility in a natural pyrope up to 200 ppm wt of water, till 10 GPa. They concluded that the proton is located in the interstitial site. Withers et al. (1998) on the contrary, observed increasing water content in Mg-rich pyrope till 6 GPa, then sudden decrease of water, beyond detection, at 7 GPa. Based on infrared spectra, Withers et al. (1998), concluded hydrogarnet (Si^{4+} replaced by 4H+ to form O4H4) substitution in synthetic magnesium rich pyrope. They argued that at high pressure owing to larger volume, hydrogarnet substitution is unstable and water is expelled out of garnet. In transition zone conditions, however, majorite garnet seems to contain around 600-700 ppm wt of water (Bolfan-Casanova et al. 2000; Katayama et al. 2003). The cause for such discrepancy is not clear and whether garnet could store a significant amount of water at mantle condition is unconstrained. In order to understand the solubility mechanism of water in pyrope at high-pressure, we have conducted high- pressure experiments on naturally occurring single crystals of pyrope garnet (from Arizona, Aines and Rossman, 1984). To ascertain water-saturated conditions, we use olivine single-crystal as an internal standard. Preliminary results indicate that natural pyrope is capable of dissolving water at high-pressures, however, water preferentially enters olivine than in pyrope. We are undertaking systematic study to estimate the solubility of water in pyrope as a function of pressure. This will enable us to develop solubility models to understand the defect mechanisms

  2. Highly active water-soluble olefin metathesis catalyst.

    PubMed

    Hong, Soon Hyeok; Grubbs, Robert H

    2006-03-22

    A novel water-soluble ruthenium olefin metathesis catalyst supported by a poly(ethylene glycol) conjugated saturated 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligand is reported. The catalyst displays improved activity in ring-opening metathesis polymerization, ring-closing metathesis, and cross-metathesis reactions in aqueous media. PMID:16536510

  3. Preparation, cytotoxicity and in vivo bioimaging of highly luminescent water-soluble silicon quantum dots

    NASA Astrophysics Data System (ADS)

    Fan, Jing-Wun; Vankayala, Raviraj; Chang, Chien-Liang; Chang, Chia-Hua; Chiang, Chi-Shiun; Hwang, Kuo Chu

    2015-05-01

    Designing various inorganic nanomaterials that are cost effective, water soluble, optically photostable, highly fluorescent and biocompatible for bioimaging applications is a challenging task. Similar to semiconducting quantum dots (QDs), silicon QDs are another alternative and are highly fluorescent, but non-water soluble. Several surface modification strategies were adopted to make them water soluble. However, the photoluminescence of Si QDs was seriously quenched in the aqueous environment. In this report, highly luminescent, water-dispersible, blue- and green-emitting Si QDs were prepared with good photostability. In vitro studies in monocytes reveal that Si QDs exhibit good biocompatibility and excellent distribution throughout the cytoplasm region, along with the significant fraction translocated into the nucleus. The in vivo zebrafish studies also reveal that Si QDs can be evenly distributed in the yolk-sac region. Overall, our results demonstrate the applicability of water-soluble and highly fluorescent Si QDs as excellent in vitro and in vivo bioimaging probes.

  4. High Expression of Water-Soluble Recombinant Antigenic Domains of Toxoplasma gondii Secretory Organelles

    PubMed Central

    Yang, Zhaoshou; Ahn, Hye-Jin

    2014-01-01

    Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1. PMID:25246715

  5. High expression of water-soluble recombinant antigenic domains of Toxoplasma gondii secretory organelles.

    PubMed

    Yang, Zhaoshou; Ahn, Hye-Jin; Nam, Ho-Woo

    2014-08-01

    Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with GRA225-105, GRA339-138, ROP2324-561, and MIC21-284 domains had respectively higher value of IgG avidity. The rGST-GRA225-105 and rGST-GRA339-138 were soluble, while rGST-ROP2324-561 and rGST-MIC21-284 were not. GRA231-71, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The rGST-GRA231-71-ROP2324-561, a chimeric protein, appeared to be soluble. Moreover, rGST-GRA231-71-MIC21-284 was also soluble and had higher IgG avidity comparing to rGST-MIC21-284. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1. PMID:25246715

  6. A novel formulation for solubility and content uniformity enhancement of poorly water-soluble drugs using highly-porous mannitol.

    PubMed

    Saffari, Morteza; Ebrahimi, Amirali; Langrish, Timothy

    2016-02-15

    The present study investigates the enhancement of the dissolution rates for poorly-water soluble drugs by a new adsorption method. The results show that the current adsorption method enhanced the dissolution rate of both nifedipine and indomethacin to a significant extent by nano-confinement of drugs into the pore spaces of highly-porous excipients. Porous mannitol particles with a surface area and pore volume of 6.3±0.1m(2)g(-1) and 0.036±0.002mlg(-1), respectively, were drug loaded in two different concentrations of indomethacin and nifedipine. The results of drug loading for nifedipine showed an increase from 3.2±0.1% w/w for a 0.08M drug solution to 9.1±0.3% w/w drug loading for a 0.16M drug solution, while indomethacin had slightly better performance for the adsorption process, with 4.1±0.2% w/w and 12.6±0.4% w/w for 0.08M and 0.16M concentrations of indomethacin, respectively, in the final formulation. This result also indicated highly-uniform blends with a percentage relative standard deviation of less than 4% for drug-loaded mannitol in both nifedipine and indomethacin. This method gave a significant enhancement of the dissolution rate for both drugs due to nano-confinement of drugs into porous excipients and high solubility of porous mannitol, with 80% drug release within the first 15min for the drug-loaded samples. PMID:26687442

  7. A review of water-soluble polymers used in high temperature oil recovery applications

    SciTech Connect

    Moradi-Araghi, A.

    1993-12-31

    In most oil bearing formations, hydrocarbons are trapped under pressure in the pores of rock matrix. This pressure which is the driving force in Production of hydrocarbons is gradually depleted as oil or gas is produced. Water is commonly injected into such reservoirs to maintain the pressure and produce an additional 10-20% of the original oil in place. However, water tends to pass through the higher permeability zones, fractures or channels, leaving a substantial amount of oil behind. Water-soluble polymers which increase the viscosity of water and thereby, reduce its mobility, are used to recover additional oil. The polymers can also be crosslinked to produce gels which are used to block the high permeability channels or fractures so subsequent water injection can produce additional oil. Both synthetic and natural water-soluble polymers have been used to recover more oil from shallower reservoirs. The hotter (< 90{degrees}C) reservoirs limit the type of polymers which can be used for polymer flooding and gelation. Neither polyacrylamides, nor xanthan gums commonly used for lower temperature reservoirs can tolerate the harsh conditions of the higher temperatures, salinity and hardness encountered in deeper reservoirs. This paper reviews the polymers and gels suitable for use in high temperature reservoirs.

  8. Highly water-soluble, porous, and biocompatible boron nitrides for anticancer drug delivery.

    PubMed

    Weng, Qunhong; Wang, Binju; Wang, Xuebin; Hanagata, Nobutaka; Li, Xia; Liu, Dequan; Wang, Xi; Jiang, Xiangfen; Bando, Yoshio; Golberg, Dmitri

    2014-06-24

    Developing materials for "Nano-vehicles" with clinically approved drugs encapsulated is envisaged to enhance drug therapeutic effects and reduce the adverse effects. However, design and preparation of the biomaterials that are porous, nontoxic, soluble, and stable in physiological solutions and could be easily functionalized for effective drug deliveries are still challenging. Here, we report an original and simple thermal substitution method to fabricate perfectly water-soluble and porous boron nitride (BN) materials featuring unprecedentedly high hydroxylation degrees. These hydroxylated BNs are biocompatible and can effectively load anticancer drugs (e.g., doxorubicin, DOX) up to contents three times exceeding their own weight. The same or even fewer drugs that are loaded on such BN carriers exhibit much higher potency for reducing the viability of LNCaP cancer cells than free drugs. PMID:24797563

  9. Water soluble conductive polymers

    SciTech Connect

    Aldissi, M.

    1989-11-14

    This patent describes 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.

  10. Efficient Route to Highly Water-Soluble Aromatic Cyclic Hydroxamic Acid Ligands

    SciTech Connect

    Seitz, Michael; Raymond, Kenneth N.

    2008-02-06

    2-Hydroxyisoquinolin-1-one (1,2-HOIQO) is a new member of the important class of aromatic cyclic hydroxamic acid ligands which are widely used in metal sequestering applications and metal chelating therapy. The first general approach for the introduction of substituents at the aromatic ring of the chelating moiety is presented. As a useful derivative, the highly water-soluble sulfonic acid has been synthesized by an efficient route that allows general access to 1,2-HOQIO 3-carboxlic acid amides, which are the most relevant for applications.

  11. Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

    PubMed

    Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

    2008-08-15

    Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus. PMID:18656674

  12. Size-controlled synthesis of highly water-soluble silver nanocrystals

    SciTech Connect

    Hu Yongxing; Ge Jianping; Lim, Donna; Zhang Tierui; Yin Yadong

    2008-07-15

    We describe a modified polyol process for the synthesis of silver nanocrystals with uniform sizes ranging from several nanometers to {approx}20 nm. The use of polyacrylic acid, in place of polyvinylpyrrolidone in the conventional polyol process, significantly limits the growth of silver nanocrystals, prevents the interparticle aggregation and fusion, and leads to a uniform population of samples with high water solubility. The size of nanocrystals can be conveniently tuned by controlling the reaction time, the concentration and chain length of the polymeric surfactants, and the reaction temperature. Uniform silver nanocrystals within sizes below 20 nm are preferred candidates over larger particles for applications where high density of optical absorption is required, for example, for photothermal conversion in cancer therapy. - Graphical abstract: Silver nanocrystals with uniform and controllable sizes (<20 nm) have been synthesized using a modified polyol process. The use of polyacrylic acid as the surfactant significantly limits the nanocrystal growth, prevents the interparticle aggregation and fusion, and leads to a uniform population of samples with high water solubility.

  13. Dipeptidyl peptidase IV dependent water-soluble prodrugs of highly lipophilic bicyclic nucleoside analogues.

    PubMed

    Diez-Torrubia, Alberto; Balzarini, Jan; Andrei, Graciela; Snoeck, Robert; De Meester, Ingrid; Camarasa, María-José; Velázquez, Sonsoles

    2011-03-24

    We present the first report of the application of the dipeptidyl peptidase IV (DPPIV/CD26) based prodrug approach to hydroxy-containing drug derivatives. In particular, we applied this strategy to the highly lipophilic antiviral drug family of bicyclic furanopyrimidine nucleoside analogues (BCNA) in order to improve their physicochemical and pharmacokinetic properties. Our stability data demonstrated that the prodrugs efficiently release the parent BCNA drug upon selective conversion by purified DPPIV/CD26 and by soluble DPPIV/CD26 present in bovine, murine, and human serum. Vildagliptin, a specific inhibitor of DPPIV/CD26, was able to completely block the hydrolysis of the prodrugs in the presence of purified DPPIV/CD26 human, murine, and bovine serum. Several novel prodrugs showed remarkable increases in water solubility (up to more than 3 orders of magnitude) compared to the poorly soluble parent drug. We also demonstrated a markedly enhanced oral bioavailability of the prodrugs versus the parent drug in mice. PMID:21332170

  14. Water solubility measurements in supercritical fluids and high-pressure liquids using near-infrared spectroscopy

    SciTech Connect

    Jackson, K.; Bowman, L.E.; Fulton, J.L.

    1995-07-15

    A small amount of water added to a supercritical fluid can greatly increase the solubility of polar species in nonpolar fluids. These modified supercritical solutions significantly expand the use of the fluids in separations and reactions. In order to successfully utilize these systems, information on the miscibility or solubility of water in the fluid is required. Often solubility data are not available for water in a supercritical fluid under a given set of temperature and pressure conditions, and a costly set of equipment must be assembled in order to make these measurements. A relatively fast and inexpensive technique to measure water solubilities using a simple long path length optical cell in an FT-IR spectrometer is described. This technique is also applicable to common and newly developed refrigerants where water solubilities are often unknown at temperatures much above ambient. In this paper, water solubility data in carbon dioxide and two types of refrigerants (chlorodifluoromethane, R22; 1,1,1,2-tetrafluoroethane, R134a) are presented for temperatures from approximately 40 to 110{degree}C and pressures from approximately 10 to 344.8 bar. 26 refs., 6 figs., 4 tabs.

  15. Identification of polar, ionic, and highly water soluble organic pollutants in untreated industrial wastewaters

    SciTech Connect

    Castillo, M.; Alonso, M.C.; Riu, J.; Barcelo, D.

    1999-04-15

    This paper presents a generic protocol for the determination of polar, ionic, and highly water soluble organic pollutants on untreated industrial wastewaters involving the use of two different solid-phase extraction (SPE) methodologies followed by liquid chromatography-mass spectrometry (LC-MS). Untreated industrial wastewaters might contain natural and synthetic dissolved organic compounds with total organic carbon (TOC) values varying between 100 and 3000 mg/L. All polar, ionic and highly water soluble compounds comprising more than 95% of the organic content and with major contribution to the total toxicity of the sample cannot be analyzed by conventional gas chromatography-mass spectrometry (GC-MS), and LC-MS is a good alternative. In this work two extraction procedures were used to obtain fractionated extracts of the nonionic polar compounds: a polymeric Isolute ENV + SPE cartridge for the preconcentration of anionic analytes and a sequential solid-phase extraction (SSPE) method percolating the samples first in octadecylsilica cartridge in series with the polymeric Lichrolut EN cartridge. Average recoveries ranging from 72% to 103% were obtained for a variety of 23 different analytes. Determination of nonionic pollutants was accomplished by reverse-phase liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), while anionic compounds were analyzed by ion pair chromatography-electrospray-mass spectrometry (IP-ESI-MS) and LC-ESI-MS. This protocol was applied to a pilot survey of textile and tannery wastewaters leading to the identification and quantification of 33 organic pollutants.

  16. 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.

  17. 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.

  18. Highly selective binding of methyl orange dye by cationic water-soluble pillar[5]arenes.

    PubMed

    Yakimova, L S; Shurpik, D N; Gilmanova, L H; Makhmutova, A R; Rakhimbekova, A; Stoikov, I I

    2016-05-01

    A new water-soluble pillar[5]arene with an amide fragment and triethylammonium groups was synthesized by our original method of aminolysis of the ester groups. Using UV-spectroscopy, it is shown that cationic pillar[5]arenes are able to selectively form 1 : 1 complexes with some hydrophobic anions: the guests with bulky uncharged or negatively charged substituents hindering entry into the macrocycle cavity. Highly selective binding of the most lipophilic guest, methyl orange dye, in the form of organic anion salts by positively charged water-soluble pillar[5]arenes was detected. In the case of the azo dye the appropriate Kass values were 10-100-fold higher than those calculated for the other sulfonic acid derivatives studied. The 2D NMR NOESY (1)H-(1)H spectroscopy confirms the formation of the inclusion complex: negative charge sulfonate head is outside the cavity of pillar[5]arenes and the hydrophobic fragment of the guest is located in the cavity. PMID:27074630

  19. Solubility of hydrocarbons and CO{sub 2} mixtures in water under high pressure

    SciTech Connect

    Dhima, A.; Hemptinne, J.C. de; Jose, J.

    1999-08-01

    New solubility data for methane, carbon dioxide, and their binary mixtures in pure water were obtained at 344.25 K and from 10 to 100 MPa. A thermodynamic model that combines a cubic equation of state (Peng-Robinson with k{sub ij} given in the literature) with the Henry`s law approach has been elaborated. It has been shown that the (P,T) functional form of Henry`s constant given by the Krichevsky-Kasarnovsky equation is applicable. It involves two important parameters: partial molar volume at infinite dilution and Henry`s constant at the vapor pressure of water. Neither of these two parameters is a function of pressure or composition. The Henry`s constant correlations of Li and Nghiem and Harvey, and the partial molar volume correlation of Lyckman et al. have been validated using a great number of solubility data.

  20. High Throughput Identification, Purification and Structural Characterization of Water Soluble Protein Complexes in Desulfovibrio vulgaris

    SciTech Connect

    Dong,, Ming; Han, Bong-Gyoon; Liu, Hui-Hai; Malik, J.; Geller, Jil; Yang, Li; Choi, M.; Chandonia, John-Marc; Arbelaez, Pablo; Sterling, H. J.; Typke, Dieter; Shatsky, Max; Brenner, Steve; Fisher, Susan; Williams, Evan; Szakal, Evelin; Allen, S.; Hall, S. C.; Hazen, Terry; Witkowska, H. E.; Jin, Jiming; Glaeser, Robert; Biggin, Mark

    2010-05-17

    Our scheme for the tagless purification of water soluble complexes. 10 g of protein from a crude bacterial extract is first fractionated by ammonium sulfate precipitation and then by a series of chromatographic steps: anion exchange (IEX), hydrophobic interaction (HIC), and finally size exclusion (Gel Filtration). Fractions from the last chromatography step are trypsin digested and peptides labeled with iTRAQ reagents to allow multiplexing and quantitation during mass spectrometric analysis. Elution profiles of identified proteins are then subjected to clustering analysis.

  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. Fluorescent water-soluble organic aerosols in the High Arctic atmosphere

    PubMed Central

    Fu, Pingqing; Kawamura, Kimitaka; Chen, Jing; Qin, Mingyue; Ren, Lujie; Sun, Yele; Wang, Zifa; Barrie, Leonard A.; Tachibana, Eri; Ding, Aijun; Yamashita, Youhei

    2015-01-01

    Organic aerosols are ubiquitous in the earth’s atmosphere. They have been extensively studied in urban, rural and marine environments. However, little is known about the fluorescence properties of water-soluble organic carbon (WSOC) or their transport to and distribution in the polar regions. Here, we present evidence that fluorescent WSOC is a substantial component of High Arctic aerosols. The ratios of fluorescence intensity of protein-like peak to humic-like peak generally increased from dark winter to early summer, indicating an enhanced contribution of protein-like organics from the ocean to Arctic aerosols after the polar sunrise. Such a seasonal pattern is in agreement with an increase of stable carbon isotope ratios of total carbon (δ13CTC) from −26.8‰ to −22.5‰. Our results suggest that Arctic aerosols are derived from a combination of the long-range transport of terrestrial organics and local sea-to-air emission of marine organics, with an estimated contribution from the latter of 8.7–77% (mean 45%). PMID:25920042

  3. A highly sensitive colorimetric determination of serum zinc using water-soluble pyridylazo dye.

    PubMed

    Makino, T; Saito, M; Horiguchi, D; Kina, K

    1982-03-26

    A colorimetric method for precise and accurate determination of zinc in serum is presented. Only 0.3 ml of sample is necessary, because of the use of a new, highly sensitive reagent, 2-(5-bromo-2-pyridylazo)-5-(N-n-propyl-N-3-sulfopropylamino)-phenol (epsilon 554nm = 1.3 X 10(5) 1 . mol-1 . cm-1), which is water-soluble and has long-term stability. Interference of iron and copper in serum can be removed by co-precipitation of the iron fluoride complex with trichloroacetic acid precipitated proteins and the copper dithiocarboxy sarcosine complex, respectively. Within-run and day-to-day precision (CV) are in the range of 0.3-3.5% and 1.9-3.1%, respectively, depending on the serum zinc content. A good correlation (r = 0.98, p less than 0.05) was obtained between this method and atomic absorption spectrometry. In contrast to previous colorimetric methods, the present method does not involve heating, extraction with organic solvents, or a cyanide masking system. PMID:7067132

  4. [Fast separation and analysis of water-soluble vitamins in spinach by capillary electrophoresis with high voltage].

    PubMed

    Hu, Xiaoqin; You, Huiyan

    2009-11-01

    In capillary electrophoresis, 0-40 kV (even higher) voltage can be reached by a connecting double-model high voltage power supply. In the article, water-soluble vitamins, VB1, VB2, VB6, VC, calcium D-pantothenate, D-biotin, nicotinic acid and folic acid in vegetable, were separated by using the high voltage power supply under the condition of electrolyte water solution as running buffer. The separation conditions, such as voltage, the concentration of buffer and pH value etc. , were optimized during the experiments. The results showed that eight water-soluble vitamins could be baseline separated in 2.2 min at 40 kV applied voltage, 25 mmol/L sodium tetraborate buffer solution (pH 8.8). The water-soluble vitamins in spinach were quantified and the results were satisfied. The linear correlation coefficients of the water-soluble vitamins ranged from 0.9981 to 0.9999. The detection limits ranged from 0.2 to 0.3 mg/L. The average recoveries ranged from 88.0% to 100.6% with the relative standard deviations (RSD) range of 1.15%-4.13% for the spinach samples. PMID:20352941

  5. Synthesis of a highly water-soluble acacetin prodrug for treating experimental atrial fibrillation in beagle dogs

    PubMed Central

    Liu, Hui; Wang, Ya-Jing; Yang, Lei; Zhou, Mei; Jin, Man-Wen; Xiao, Guo-Sheng; Wang, Yan; Sun, Hai-Ying; Li, Gui-Rong

    2016-01-01

    We previously reported that duodenal administration of the natural flavone acacetin can effectively prevent the induction of experimental atrial fibrillation (AF) in canines; however, it may not be used intravenously to terminate AF due to its poor water-solubility. The present study was to design a water-soluble prodrug of acacetin and investigate its anti-AF effect in beagle dogs. Acacetin prodrug was synthesized by a three-step procedure. Aqueous solubility, bioconversion and anti-AF efficacy of acacetin prodrug were determined with different methodologies. Our results demonstrated that the synthesized phosphate sodium salt of acacetin prodrug had a remarkable increase of aqueous solubility in H2O and clinically acceptable solution (5% glucose or 0.9% NaCl). The acacetin prodrug was effectively converted into acacetin in ex vivo rat plasma and liver microsome, and in vivo beagle dogs. Intravenous infusion of acacetin prodrug (3, 6 and 12 mg/kg) terminated experimental AF without increasing ECG QTc interval in beagle dogs. The intravenous LD50 of acacetin prodrug was 721 mg/kg in mice. Our preclinical study indicates that the synthesized acacetin prodrug is highly water-soluble and safe; it effectively terminates experimental AF in beagle dogs and therefore may be a promising drug candidate for clinical trial to treat patients with acute AF. PMID:27160397

  6. Synthesis of a highly water-soluble acacetin prodrug for treating experimental atrial fibrillation in beagle dogs.

    PubMed

    Liu, Hui; Wang, Ya-Jing; Yang, Lei; Zhou, Mei; Jin, Man-Wen; Xiao, Guo-Sheng; Wang, Yan; Sun, Hai-Ying; Li, Gui-Rong

    2016-01-01

    We previously reported that duodenal administration of the natural flavone acacetin can effectively prevent the induction of experimental atrial fibrillation (AF) in canines; however, it may not be used intravenously to terminate AF due to its poor water-solubility. The present study was to design a water-soluble prodrug of acacetin and investigate its anti-AF effect in beagle dogs. Acacetin prodrug was synthesized by a three-step procedure. Aqueous solubility, bioconversion and anti-AF efficacy of acacetin prodrug were determined with different methodologies. Our results demonstrated that the synthesized phosphate sodium salt of acacetin prodrug had a remarkable increase of aqueous solubility in H2O and clinically acceptable solution (5% glucose or 0.9% NaCl). The acacetin prodrug was effectively converted into acacetin in ex vivo rat plasma and liver microsome, and in vivo beagle dogs. Intravenous infusion of acacetin prodrug (3, 6 and 12 mg/kg) terminated experimental AF without increasing ECG QTc interval in beagle dogs. The intravenous LD50 of acacetin prodrug was 721 mg/kg in mice. Our preclinical study indicates that the synthesized acacetin prodrug is highly water-soluble and safe; it effectively terminates experimental AF in beagle dogs and therefore may be a promising drug candidate for clinical trial to treat patients with acute AF. PMID:27160397

  7. 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.

  8. High mobility organic field-effect transistor based on water-soluble deoxyribonucleic acid via spray coating

    SciTech Connect

    Shi, Wei; Han, Shijiao; Huang, Wei; Yu, Junsheng

    2015-01-26

    High mobility organic field-effect transistors (OFETs) by inserting water-soluble deoxyribonucleic acid (DNA) buffer layer between electrodes and pentacene film through spray coating process were fabricated. Compared with the OFETs incorporated with DNA in the conventional organic solvents of ethanol and methanol: water mixture, the water-soluble DNA based OFET exhibited an over four folds enhancement of field-effect mobility from 0.035 to 0.153 cm{sup 2}/Vs. By characterizing the surface morphology and the crystalline structure of pentacene active layer through atomic force microscope and X-ray diffraction, it was found that the adoption of water solvent in DNA solution, which played a key role in enhancing the field-effect mobility, was ascribed to both the elimination of the irreversible organic solvent-induced bulk-like phase transition of pentacene film and the diminution of a majority of charge trapping at interfaces in OFETs.

  9. ESTIMATION OF WATER SOLUBILITY AND OCTANOL/WATER PARTITION COEFFICIENT OF HYDROPHOBIC DYES - PART II. REVERSE-PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    EPA Science Inventory

    Capacity factors were determined for 20 disperse and solvent dyes by a high performance liquid chromatographic method using methanol/water and a C-18 reverse-phase column. egression equations are given that establish relationships among capacity factors, water solubilities and oc...

  10. High-Resolution Electrospray Ionization Mass Spectrometry Analysis of Water- Soluble Organic Aerosols Collected with a Particle into Liquid Sampler

    SciTech Connect

    Bateman, Adam P.; Nizkorodov, Serguei; Laskin, Julia; Laskin, Alexander

    2010-10-01

    This work demonstrates the utility of a particle-into-liquid sampler (PILS) a technique traditionally used for identification of inorganic ions present in ambient or laboratory aerosols for the analysis of water soluble organic aerosol (OA) using high resolution electrospray ionization mass spectrometry (HR ESI-MS). Secondary organic aerosol (SOA) was produced from 0.5 ppm mixing ratios of limonene and ozone in a 5 m3 Teflon chamber. SOA was collected simultaneously using a traditional filter sampler and a PILS. The filter samples were later extracted with either water or acetonitrile, while the aqueous PILS samples were analyzed directly. In terms of peak intensities, types of detectable compounds, average O:C ratios, and organic mass to organic carbon ratios, the resulting high resolution mass spectra were essentially identical for the PILS and filter based samples. SOA compounds extracted from both filter/acetonitrile extraction and PILS/water extraction accounted for >95% of the total ion current in ESI mass spectra. This similarity was attributed to high solubility of limonene SOA in water. In contrast, significant differences in detected ions and peak abundances were observed for pine needle biomass burning organic aerosol (BBOA) collected with PILS and filter sampling. The water soluble fraction of BBOA is considerably smaller than for SOA, and a number of unique peaks were detectable only by the filter/acetonitrile method. The combination of PILS collection with HR-ESI-MS analysis offers a new approach for molecular analysis of the water-soluble organic fraction in biogenic SOA, aged photochemical smog, and BBOA.

  11. Prediction of oxygen solubility in pure water and brines up to high temperatures and pressures

    NASA Astrophysics Data System (ADS)

    GENG, Ming; DUAN, Zhenhao

    2010-10-01

    A thermodynamic model is presented to calculate the oxygen solubility in pure water (273-600 K, 0-200 bar) and natural brines containing Na +, K +, Ca 2+, Mg 2+, Cl -, SO 42-, over a wide range of temperature, pressure and ionic strength with or close to experimental accuracy. This model is based on an accurate equation of state to calculate vapor phase chemical potential and a specific particle interaction model for liquid phase chemical potential. With this approach, the model can not only reproduce the existing experimental data, but also extrapolate beyond the data range from simple aqueous salt system to complicated brine systems including seawater. Compared with previous models, this model covers much wider temperature and pressure space in variable composition brine systems. A program for this model can be downloaded from the website: http://www.geochem-model.org.

  12. Water/alcohol soluble conjugated polymers as highly efficient electron transporting/injection layer in optoelectronic devices.

    PubMed

    Huang, Fei; Wu, Hongbin; Cao, Yong

    2010-07-01

    Water/alcohol soluble conjugated polymers (WSCPs) can be processed from water or other polar solvents, which offer good opportunities to avoid interfacial mixing upon fabrication of multilayer polymer optoelectronic devices by solution processing, and can dramatically improve charge injection from high work-function metal cathode resulting in greatly enhancement of the device performance. In this critical review, the authors provide a brief review of recent developments in this field, including the materials design, functional principles, and their unique applications as interface modification layer in solution-processable multilayer optoelectronic devices (135 references). PMID:20571672

  13. Highly Luminescent, Water-Soluble Lanthanide Fluorobenzoates: Syntheses, Structures and Photophysics, Part I: Lanthanide Pentafluorobenzoates.

    PubMed

    Kalyakina, Alena S; Utochnikova, Valentina V; Bushmarinov, Ivan S; Ananyev, Ivan V; Eremenko, Igor L; Volz, Daniel; Rönicke, Franziska; Schepers, Ute; Van Deun, Rik; Trigub, Alexander L; Zubavichus, Yan V; Kuzmina, Natalia P; Bräse, Stefan

    2015-12-01

    Highly luminescent, photostable, and soluble lanthanide pentafluorobenzoates have been synthesized and thoroughly characterized, with a focus on Eu(III) and Tb(III) complexes as visible emitters and Nd(III) , Er(III) , and Yb(III) complexes as infrared emitters. Investigation of the crystal structures of the complexes in powder form and as single crystals by using X-ray diffraction revealed five different structural types, including monomeric, dimeric, and polymeric. The local structure in different solutions was studied by using X-ray absorption spectroscopy. The photoluminescence quantum yields (PLQYs) of terbium and europium complexes were 39 and 15 %, respectively; the latter value was increased almost twice by using the heterometallic complex [Tb0.5 Eu0.5 (pfb)3 (H2 O)] (Hpfb=pentafluorobenzoic acid). Due to the effectively utilized sensitization strategy (pfb)(-) →Tb→Eu, a pure europium luminescence with a PLQY of 29 % was achieved. PMID:26489887

  14. Water-soluble conductive polymers

    SciTech Connect

    Aldissi, M.

    1990-05-29

    This patent describes 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.

  15. 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.

  16. 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.

  17. 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.

  18. Fabrication of magnetic water-soluble hyperbranched polyol functionalized graphene oxide for high-efficiency water remediation.

    PubMed

    Hu, Lihua; Li, Yan; Zhang, Xuefei; Wang, Yaoguang; Cui, Limei; Wei, Qin; Ma, Hongmin; Yan, Liangguo; Du, Bin

    2016-01-01

    Magnetic water-soluble hyperbranched polyol functionalized graphene oxide nanocomposite (MWHPO-GO) was successfully prepared and applied to water remediation in this paper. MWHPO-GO was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), magnetization curve, zeta potential, scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses. MWHPO-GO exhibited excellent adsorption performance for the removal of synthetic dyes (methylene blue (MB) and methyl violet (MV)) and heavy metal (Pb(II)). Moreover, MWHPO-GO could be simply recovered from water with magnetic separation. The pseudo-second order equation and the Langmuir model exhibited good correlation with the adsorption kinetic and isotherm data, respectively, for these three pollutants. The thermodynamic results (ΔG < 0, ΔH < 0, ΔS < 0) implied that the adsorption process of MB, MV and Pb(II) was feasible, exothermic and spontaneous in nature. A possible adsorption mechanism has been proposed where π-π stacking interactions, H-bonding interaction and electrostatic attraction dominated the adsorption of MB/MV and chelation and electrostatic attraction dominated the adsorption of Pb(II). In addition, the excellent reproducibility endowed MWHPO-GO with the potential for application in water remediation. PMID:27354318

  19. Fabrication of magnetic water-soluble hyperbranched polyol functionalized graphene oxide for high-efficiency water remediation

    PubMed Central

    Hu, Lihua; Li, Yan; Zhang, Xuefei; Wang, Yaoguang; Cui, Limei; Wei, Qin; Ma, Hongmin; Yan, Liangguo; Du, Bin

    2016-01-01

    Magnetic water-soluble hyperbranched polyol functionalized graphene oxide nanocomposite (MWHPO-GO) was successfully prepared and applied to water remediation in this paper. MWHPO-GO was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), magnetization curve, zeta potential, scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses. MWHPO-GO exhibited excellent adsorption performance for the removal of synthetic dyes (methylene blue (MB) and methyl violet (MV)) and heavy metal (Pb(II)). Moreover, MWHPO-GO could be simply recovered from water with magnetic separation. The pseudo-second order equation and the Langmuir model exhibited good correlation with the adsorption kinetic and isotherm data, respectively, for these three pollutants. The thermodynamic results (ΔG < 0, ΔH < 0, ΔS < 0) implied that the adsorption process of MB, MV and Pb(II) was feasible, exothermic and spontaneous in nature. A possible adsorption mechanism has been proposed where π-π stacking interactions, H-bonding interaction and electrostatic attraction dominated the adsorption of MB/MV and chelation and electrostatic attraction dominated the adsorption of Pb(II). In addition, the excellent reproducibility endowed MWHPO-GO with the potential for application in water remediation. PMID:27354318

  20. Fabrication of magnetic water-soluble hyperbranched polyol functionalized graphene oxide for high-efficiency water remediation

    NASA Astrophysics Data System (ADS)

    Hu, Lihua; Li, Yan; Zhang, Xuefei; Wang, Yaoguang; Cui, Limei; Wei, Qin; Ma, Hongmin; Yan, Liangguo; Du, Bin

    2016-06-01

    Magnetic water-soluble hyperbranched polyol functionalized graphene oxide nanocomposite (MWHPO-GO) was successfully prepared and applied to water remediation in this paper. MWHPO-GO was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), magnetization curve, zeta potential, scanning electron microscope (SEM) and transmission electron microscope (TEM) analyses. MWHPO-GO exhibited excellent adsorption performance for the removal of synthetic dyes (methylene blue (MB) and methyl violet (MV)) and heavy metal (Pb(II)). Moreover, MWHPO-GO could be simply recovered from water with magnetic separation. The pseudo-second order equation and the Langmuir model exhibited good correlation with the adsorption kinetic and isotherm data, respectively, for these three pollutants. The thermodynamic results (ΔG < 0, ΔH < 0, ΔS < 0) implied that the adsorption process of MB, MV and Pb(II) was feasible, exothermic and spontaneous in nature. A possible adsorption mechanism has been proposed where π-π stacking interactions, H-bonding interaction and electrostatic attraction dominated the adsorption of MB/MV and chelation and electrostatic attraction dominated the adsorption of Pb(II). In addition, the excellent reproducibility endowed MWHPO-GO with the potential for application in water remediation.

  1. Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin

    SciTech Connect

    Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

    2007-08-29

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

  2. Highly luminescent water-soluble quaternary Zn-Ag-In-S quantum dots for tumor cell-targeted imaging.

    PubMed

    Deng, Dawei; Cao, Jie; Qu, Lingzhi; Achilefu, Samuel; Gu, Yueqing

    2013-04-14

    Exploring the synthesis and biomedical applications of biocompatible quantum dots (QDs) is currently one of the fastest growing fields of nanotechnology. Hence, in this work, we present a facile approach to produce water-soluble (cadmium-free) quaternary Zn-Ag-In-S (ZAIS) QDs. Their efficient photoluminescence (PL) emissions can be tuned widely in the range of 525-625 nm by controlling the size and composition of the QDs with the PL quantum yields (QYs) of 15-30%. These highly luminescent ZAIS QDs are less toxic due to the absence of highly toxic cadmium, and can be versatilely modified by a DHLA-PEG-based ligand. Importantly, after being modified by tumor cell-specific targeting ligands (e.g., folate and RGD peptide), the PEGylated quaternary QDs show potential applications in tumor cell imaging as a promising alternative for Cd-based QDs. PMID:23450151

  3. Cultivar by environment effects of perennial ryegrass cultivars selected for high water soluble carbohydrates managed under differing precipitation levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historic results of perennial ryegrass (Lolium perenne L.) breeding include improved disease resistance, biomass, and nutritional quality. Yet, lack of tolerance to water stress limits its wise use. Recent efforts to increase water soluble carbohydrate (WSC) content in perennial ryegrass may incre...

  4. Ammonia Solubility in High Concentration Salt Solutions

    SciTech Connect

    HEDENGREN, D.C.

    2000-02-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

  5. A facile and high-recovery material for rare-metals based on a water-soluble polyallylamine with side-chain thiourea groups.

    PubMed

    Nagai, Daisuke; Yoshida, Megumi; Kishi, Takuya; Morinaga, Hisatoyo; Hara, Yusuke; Mori, Masanobu; Kawakami, Satoshi; Inoue, Kenji

    2013-08-01

    We describe a facile and high-recovery material for rare metals based on a polymer combining amino groups for water solubility and thiourea groups for metal complexation. Good solubility in aqueous metal ion solutions allows for homogeneous and efficient adsorption by the polymer, and a maximum Pd(II) recovery amount (0.508 gPd gpolymer(-1)) greater than those of other polymers reported in the literature. PMID:23788410

  6. Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature.

    PubMed

    Yang, Chih-Ping; Chen, Hsiao-Chien; Wang, Ching-Chiung; Tsai, Po-Wei; Ho, Chia-Wen; Liu, Yu-Chuan

    2015-01-01

    Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water's tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water's fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte's concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water's fundamental activities via effective energy transfer. PMID:26658304

  7. Water-soluble nanocrystalline cellulose films with highly transparent and oxygen barrier properties

    NASA Astrophysics Data System (ADS)

    Cheng, Shaoling; Zhang, Yapei; Cha, Ruitao; Yang, Jinliang; Jiang, Xingyu

    2015-12-01

    By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food.By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07647a

  8. Water-soluble nanocrystalline cellulose films with highly transparent and oxygen barrier properties.

    PubMed

    Cheng, Shaoling; Zhang, Yapei; Cha, Ruitao; Yang, Jinliang; Jiang, Xingyu

    2016-01-14

    By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food. PMID:26661341

  9. Biochemical synthesis of water soluble conducting polymers

    NASA Astrophysics Data System (ADS)

    Bruno, Ferdinando F.; Bernabei, Manuele

    2016-05-01

    An efficient biomimetic route for the synthesis of conducting polymers/copolymers complexed with lignin sulfonate and sodium (polystyrenesulfonate) (SPS) will be presented. This polyelectrolyte assisted PEG-hematin or horseradish peroxidase catalyzed polymerization of pyrrole (PYR), 3,4 ethyldioxithiophene (EDOT) and aniline has provided a route to synthesize water-soluble conducting polymers/copolymers under acidic conditions. The UV-vis, FTIR, conductivity and cyclic voltammetry studies for the polymers/copolymer complex indicated the presence of a thermally stable and electroactive polymers. Moreover, the use of water-soluble templates, used as well as dopants, provided a unique combination of properties such as high electronic conductivity, and processability. These polymers/copolymers are nowadays tested/evaluated for antirust features on airplanes and helicopters. However, other electronic applications, such as photovoltaics, for transparent conductive polyaniline, actuators, for polypyrrole, and antistatic films, for polyEDOT, will be proposed.

  10. Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature

    NASA Astrophysics Data System (ADS)

    Yang, Chih-Ping; Chen, Hsiao-Chien; Wang, Ching-Chiung; Tsai, Po-Wei; Ho, Chia-Wen; Liu, Yu-Chuan

    2015-12-01

    Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water’s tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water’s fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte’s concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4’-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water’s fundamental activities via effective energy transfer.

  11. Effective Energy Transfer via Plasmon-Activated High-Energy Water Promotes Its Fundamental Activities of Solubility, Ionic Conductivity, and Extraction at Room Temperature

    PubMed Central

    Yang, Chih-Ping; Chen, Hsiao-Chien; Wang, Ching-Chiung; Tsai, Po-Wei; Ho, Chia-Wen; Liu, Yu-Chuan

    2015-01-01

    Water is a ubiquitous solvent in biological, physical, and chemical processes. Unique properties of water result from water’s tetrahedral hydrogen-bonded (HB) network (THBN). The original THBN is destroyed when water is confined in a nanosized environment or localized at interfaces, resulting in corresponding changes in HB-dependent properties. In this work, we present an innovative idea to validate the reserve energy of high-energy water and applications of high-energy water to promote water’s fundamental activities of solubility, ionic conductivity, and extraction at room temperature. High-energy water with reduced HBs was created by utilizing hot electrons with energies from the decay of surface plasmon excited at gold (Au) nanoparticles (NPs). Compared to conventional deionized (DI) water, solubilities of alkali metal-chloride salts in high-energy water were significantly increased, especially for salts that release heat when dissolved. The ionic conductivity of NaCl in high-energy water was also markedly higher, especially when the electrolyte’s concentration was extremely low. In addition, antioxidative components, such as polyphenols and 2,3,5,4’-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG) from teas, and Polygonum multiflorum (PM), could more effectively be extracted using high-energy water. These results demonstrate that high-energy water has emerged as a promising innovative solvent for promoting water’s fundamental activities via effective energy transfer. PMID:26658304

  12. A continuous and highly effective static mixing process for antisolvent precipitation of nanoparticles of poorly water-soluble drugs.

    PubMed

    Dong, Yuancai; Ng, Wai Kiong; Hu, Jun; Shen, Shoucang; Tan, Reginald B H

    2010-02-15

    Rapid and homogeneous mixing of the solvent and antisolvent is critical to achieve submicron drug particles by antisolvent precipitation technique. This work aims to develop a continuous and highly effective static mixing process for antisolvent precipitation of nanoparticles of poorly water-soluble drugs with spironolactone as a model drug. Continuous antisolvent production of drug nanoparticles was carried out with a SMV DN25 static mixer comprising 6-18 mixing elements. The total flow rate ranged from 1.0 to 3.0 L/min while the flow rate ratio of solvent to antisolvent was maintained at 1:9. It is found that only 6 mixing elements were sufficient to precipitate the particles in the submicron range. Increasing the number of elements would further reduce the precipitated particle size. Increasing flow rate from 1.0 to 3.0 L/min did not further reduce the particle size, while higher drug concentrations led to particle size increase. XRD and SEM results demonstrated that the freshly precipitated drug nanoparticles are in the amorphous state, which would, in presence of the mixture of solvent and antisolvent, change to crystalline form in short time. The lyophilized spironolactone nanoparticles with lactose as lyoprotectant possessed good redispersibility and showed 6.6 and 3.3 times faster dissolution rate than that of lyophilized raw drug formulation in 5 and 10 min, respectively. The developed static mixing process exhibits high potential for continuous and large-scale antisolvent precipitation of submicron drug particles. PMID:19922777

  13. Synthesis of highly water-soluble fluorescent conjugated glycopoly(p-phenylene)s for lectin and Escherichia coli.

    PubMed

    Xue, Cuihua; Jog, Sonali P; Murthy, Pushpalatha; Liu, Haiying

    2006-09-01

    Two facile, convenient, and versatile synthetic approaches are used to covalently attach carbohydrate residues to conjugated poly(p-phenylene)s (PPPs) for highly water-soluble PPPs bearing alpha-mannopyranosyl and beta-glucopyranosyl pendants (polymers A and B), which highly fluoresce in phosphate buffer (pH 7.0). The post-polymerization functionalization approach is to treat bromo-bearing PPP (polymer 1) with 1-thiolethyl-alpha-D-mannose tetraacetate or 1-thiol-beta-D-glucose tetraacetate in THF solution in the presence of K(2)CO(3) at room temperature through formation of thioether bridges, affording polymer 2a or 2b. The prepolymerization functionalization approach is to polymerize a well-defined sugar-carrying monomer, affording polymer 2a. Polymers 2a and 2b were deacetylated under Zemplén conditions in methanol and methylene chloride containing sodium methoxide, affording polymers A and B, respectively. The multivalent display of carbohydrates on the fluorescent conjugated glycopolymer overcomes the characteristic low binding affinity of the individual carbohydrates to their receptor proteins. Titration of concanavalin A (Con A) to alpha-mannose-bearing polymer A resulted in significant fluorescent quenching of the polymer with Stern-Volmer quenching constant of 4.5 x 10(7). Incubation of polymer A with Escherichia coli (E. coli) lead to formation of fluorescently stained bacterial clusters. Beta-glucose-bearing polymer B displayed no response to Con A and E. coli. PMID:16961305

  14. Highly Soluble Tris-hydroxypyridonate Gd(III) Complexes with Increased Hydration Number, Fast Water Exchange, Slow Electronic Relaxation, and High Relaxivity1

    SciTech Connect

    Werner, Eric J.; Avedano, Stefano; Botta, Mauro; Hay, Benjamin P.; Moore, Evan G.; Aime, Silvio; Raymond, Kenneth N.

    2007-02-21

    The design, synthesis, and relaxivity properties of a highly soluble TACN-capped hydroxypyridonate Gd(III) complex are presented. Molecular mechanics modeling was used to help design a complex capable of possessing three water molecules in the inner metal coordination sphere, an attractive property for high-relaxivity MRI contrast agents. The measured relaxivity of 13.1 mM-1s-1 is consistent with three coordinated waters and represents one of the highest known relaxivities of any low-molecular weight Gd complex. An extremely fast water exchange rate, long electronic relaxation time, and unique pH dependent relaxivity of the complex are also discussed. B.P.H. acknowledges support from the Environmental Management Science Program, Office of Science, U.S. Department of Energy (grant 73759). Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  15. Highly water-soluble mast cell stabiliser-encapsulated solid lipid nanoparticles with enhanced oral bioavailability.

    PubMed

    Patel, Ravi R; Chaurasia, Sundeep; Khan, Gayasuddin; Chaubey, Pramila; Kumar, Nagendra; Mishra, Brahmeshwar

    2016-05-01

    Cromolyn sodium (CS), a mast cell stabiliser, is widely employed for the prevention and treatment of allergic conditions. However, high hydrophilicity and poor oral permeability hinder its oral clinical translation. Here, solid lipid nanoparticles (SLNs) have been developed for the purpose of oral bioavailability enhancement. The CS-SLNs were engineered by double emulsification method (W1/O/W2) and optimised by using Box-Behnken experimental design. The surface and solid-state characterisations revealed the presence of CS in an amorphous form without any interactions inside the spherical-shaped SLNs. The in-vitro release study showed an extended release up to 24 hr by diffusion controlled process. Ex-vivo and in-vivo intestinal permeation study showed ∼2.96-fold increase in permeability of CS by presentation as SLNs (p < 0.05). Further, in-vivo pharmacokinetic study exhibited ∼2.86-fold enhancements in oral bioavailability of CS by encapsulating inside SLNs, which clearly indicate that SLNs can serve as the potential therapeutic carrier system for oral delivery of CS. PMID:26885889

  16. Production of concentrates of mono- and dihydric phenols from the total water-soluble phenols formed in the high-speed pyrolysis of brown coals

    SciTech Connect

    Kazakov, E.I.; Belov, P.S.; Korenev, K.P.; Molchanova, I.V.

    1982-01-01

    The results are given of the separation of the water-soluble phenols obtained in the high-speed pyrolysis of Kansk-Achinsk coals into uniform concentrates of mono- and dihydric phenols. It has been shown that the concentrate of monhydric phenols is suitable for working up by a known technology into phenolic products.

  17. Thermodynamics of the sorption of water-soluble vitamins in reverse-phase high performance liquid chromatography

    NASA Astrophysics Data System (ADS)

    Chirkin, V. A.; Karpov, S. I.; Selemenev, V. F.

    2012-12-01

    The thermodynamics of the sorption of certain water-soluble vitamins on a C18 reverse phase from water-acetonitrile solutions of different compositions is studied. The thermodynamic characteristics of the investigated chromatographic systems are calculated. The dependences of standard molar enthalpy and changes in entropy when the sorbate transfers from the bulk solution to the surface layer on the concentration of the organic component in the mobile phase are analyzed. The boundaries for applying the main retention models describing the sorption of the investigated compounds are discussed.

  18. Odorants with Multiple Oxygen-Containing Functional Groups and Other Odorants with High Water Solubility Preferentially Activate Posterior Olfactory Bulb Glomeruli

    PubMed Central

    Johnson, Brett A.; Arguello, Spart; Leon, Michael

    2008-01-01

    In past studies in which we mapped 2-deoxyglucose uptake evoked by systematically different odorant chemicals across the entire rat olfactory bulb, glomerular responses could be related to each odorant's particular oxygen-containing functional group. In the present study, we tested whether aliphatic odorants containing two such functional groups (esters, ketones, acids, alcohols, and ethers) would stimulate the combination of glomerular regions that are associated with each of the functional groups separately, or whether they would evoke unique responses in different regions of the bulb. We found that these very highly water-soluble molecules rarely evoked activity in the regions responding to the individual functional groups; instead, they activated posterior glomeruli located about halfway between the dorsal and ventral extremes in both the lateral and the medial aspects of the bulb. Additional highly water-soluble odorants, including very small molecules with single oxygenic groups, also strongly stimulated these posterior regions, resulting in a statistically significant correlation between posterior 2-deoxyglucose uptake and molecular properties associated with water solubility. By showing that highly water-soluble odorants stimulate a part of the bulb associated with peripheral and ventral regions of the epithelium, our results challenge a prevalent notion that such odorants would activate class I odorant receptors located in zone 1 of the olfactory epithelium, which projects to the dorsal aspect of the bulb. PMID:17366613

  19. Thin-coated water soluble CdTeS alloyed quantum dots as energy donors for highly efficient FRET.

    PubMed

    Yahia-Ammar, Akram; Nonat, Aline M; Boos, Anne; Rehspringer, Jean-Luc; Asfari, Zouhair; Charbonnière, Loïc J

    2014-11-01

    The synthesis of highly luminescent water soluble CdTe(x)S(y) quantum dots (QDs) is described and their elemental composition and optical properties are fully characterized. Glutathione (GSH)-capped nanocrystals were obtained from an aqueous solution of CdCl2, Na2TeO3 and GSH in the presence of NaBH4 upon heating at 100 °C. Spherical CdTe(x)S(y) alloyed nanoparticles with diameters ranging from 2 to 4 nm were formed, and characterized by X-ray powder diffraction and Transmission Electron Microscopy. Their elemental composition was determined from Inductively Coupled Plasma Atomic Emission Spectroscopy and CHN elemental analysis experiments. A model for the determination of their molecular formulas, molecular weights and extinction coefficients is proposed. Surface GSH molecules were involved in amide bond formation with fluorescent Nile-Red molecules, to be used as energy acceptor in Förster resonance energy transfer (FRET) experiments. FRET was observed from the CdTe(x)S(y) core (λ(ex) = 430 nm) to the Nile-Red dye (λ(em) = 648 nm) with an almost quantitative FRET efficiency (η(FRET) = 98%). A detailed analysis of the FRET is presented, revealing a core-dye distance of 24 Å, in very good agreement with the estimated radius of the core (13 Å) as measured by TEM. The QDs present excellent photophysical properties (QY up to 29%), easy synthesis and can be isolated as solids and redispersed in water without loss of their photoluminescence efficiency. PMID:25204518

  20. High time-resolution chemical characterization of the water-soluble fraction of ambient aerosols with PILS-TOC-IC and AMS

    NASA Astrophysics Data System (ADS)

    Timonen, H.; Aurela, M.; Carbone, S.; Saarnio, K.; Saarikoski, S.; Mäkelä, T.; Kulmala, M.; Kerminen, V.-M.; Worsnop, D. R.; Hillamo, R.

    2010-08-01

    A particle-into-liquid sampler (PILS) was coupled with a total organic carbon analyzer (TOC) and two ion chromatographs (IC) to enable high time-resolution measurements of water-soluble ions and water-soluble organic carbon (WSOC) by a single sampling and analytical set-up. The new high time-resolution measurement system, the PILS-TOC-IC, was able to provide essential chemical and physical information about fast changes in composition, concentrations and likely sources of the water-soluble fraction of atmospheric aerosol. The concentrations of major water-soluble ions and WSOC were measured by the PILS-TOC-IC system from 25 April to 28 May 2009. The data of the PILS-TOC-IC setup was compared with the data from the High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) data measured from 25 April to 8 May 2009. The measured water-soluble particulate organic matter (WSPOM) concentration varied typically from 0.10 to 8.8 μg m-3 (on average 1.5 μg m-3). The WSPOM contributed on average 51% to particulate organic matter (POM) measured with the AMS. The correlation between the data of all the online measurement devices (AMS, PILS-TOC-IC, semicontinuous EC/OC carbon analyzer and TEOM) was excellent. For sulfate, nitrate and ammonium the correlations between the PILS-TOC-IC and AMS were 0.93, 0.96 and 0.96, respectively. The correlation between WSPOM and POM was also strong (r = 0.88). The identified sources of WSPOM were long-range transported biomass burning and secondary organic aerosol (SOA) formation. WSPOM and oxalate produced in biomass burning were clearly correlated with carbon monoxide.

  1. Effects of chitosan and water-soluble chitosan micro- and nanoparticles in obese rats fed a high-fat diet

    PubMed Central

    Zhang, Hong-liang; Zhong, Xiao-bin; Tao, Yi; Wu, Si-hui; Su, Zheng-quan

    2012-01-01

    Purpose: This study determined the effects of chitosan (CTS) and water-soluble chitosan (WSC) microparticles (MPs) and nanoparticles (NPs) in rats with high-fat diet-induced obesity. Methods: The rats were randomly separated into eight groups: a normal diet group (the blank control), a high-fat emulsion group (the negative control), CTS and WSC control groups, CTS-MP and WSC-MP groups, and CTS-NP and WSC-NP groups. All groups (except the blank control group) were fed the high-fat diet for 4 weeks to establish the obesity model. Different samples were administered orally once daily to the treatment groups for 4 weeks. Results: A significantly lower weight gain was observed in the WSC-MP and WSC-NP groups, as well as in the CTS-MP and CTS-NP groups, compared with rats given a normal diet and a high-fat diet (P < 0.05). The WSC-MP rats had the least weight gain among all the groups. The food intake in the eight groups had the same trend as weight gain. CTS and WSC MPs and NPs significantly reduced the final amounts of epididymal and perirenal white adipose tissue. Liver weight was reduced in the CTS-MP group compared to rats fed a high-fat diet. Serum total cholesterol and low-density lipoprotein cholesterol were significantly reduced in all treatment groups, with the WSC-MP and CTS-MP groups showing a more significant reduction than the other groups. Triacylglycerol levels were significantly reduced in the WSC-NP group compared to the high-fat group. The mortality rates of CTS-MP, CTS-NP, WSC-MP, and WSC-NP groups were 30%, 30%, 55%, and 65%, respectively. The median lethal dose for the WSC-MP and WSC-NP groups were 4080 mg/kg and 2370 mg/kg, respectively. Conclusion: These results indicate that CTS and WSC MPs and NPs have greater effects than commercially available CTS and WSC, and can be used as potential antiobesity agents. PMID:22888243

  2. Polyglycerol-Dendronized Perylenediimides as Stable, Water-Soluble Fluorophores

    PubMed Central

    Yang, Si Kyung

    2013-01-01

    The synthesis and photophysical properties of water-soluble, fluorescent polyglycerol-dendronized perylenediimides 1–4 are reported. The polyglycerol dendrons, which are known to be highly biocompatible, are found to confer high water-solubility on the perylenediimide in aqueous media while retaining its excellent fluorescent properties. Furthermore, intramolecular cross-linking of the polyglycerol dendrons using the ring-closing metathesis reaction not only enhances the photostability but also reduces the size of perylenediimide-cored dendrimers. The permeability of the various dendritic shells is probed using heavy metal ion quenchers and compared to non-dendritic but water-soluble perylenediimide 5. PMID:23459294

  3. A highly active water-soluble cross-coupling catalyst based on dendritic polyglycerol N-heterocyclic carbene palladium complexes.

    PubMed

    Meise, Markus; Haag, Rainer

    2008-01-01

    A new water-soluble polyglycerol derivative functionalized with N-heterocyclic carbene palladium complexes was prepared and applied as catalyst for Suzuki cross-coupling reactions in water. The complex displays a metal loading of around 65 metal centers per dendrimeric molecule, which is estimated to contain 130 chelating groups and thus corresponds approximately to the formation of 2:1 NHC/metal complexes. Monomeric analogues were also synthesized to validate the reactivity of the dendritic catalyst. Both types of catalysts were tested with various aryl bromides and arylboronic acids. Turnover frequencies of up to 2586 h(-1) at 80 degrees C were observed with the dendritic catalyst along with turnover numbers of up to 59 000, which are among the highest turnover numbers reported for polymer-supported catalysts in neat water. The dendritic catalyst could be used (reused) in five consecutive reactions without loss in activity. PMID:18702166

  4. n-Type Water/Alcohol-Soluble Naphthalene Diimide-Based Conjugated Polymers for High-Performance Polymer Solar Cells.

    PubMed

    Wu, Zhihong; Sun, Chen; Dong, Sheng; Jiang, Xiao-Fang; Wu, Siping; Wu, Hongbin; Yip, Hin-Lap; Huang, Fei; Cao, Yong

    2016-02-17

    With the demonstration of small-area, single-junction polymer solar cells (PSCs) with power conversion efficiencies (PCEs) over the 10% performance milestone, the manufacturing of high-performance large-area PSC modules is becoming the most critical issue for commercial applications. However, materials and processes that are optimized for fabricating small-area devices may not be applicable for the production of high-performance large-area PSC modules. One of the challenges is to develop new conductive interfacial materials that can be easily processed with a wide range of thicknesses without significantly affecting the performance of the PSCs. Toward this goal, we report two novel naphthalene diimide-based, self-doped, n-type water/alcohol-soluble conjugated polymers (WSCPs) that can be processed with a broad thickness range of 5 to 100 nm as efficient electron transporting layers (ETLs) for high-performance PSCs. Space charge limited current and electron spin resonance spectroscopy studies confirm that the presence of amine or ammonium bromide groups on the side chains of the WSCP can n-dope PC71BM at the bulk heterojunction (BHJ)/ETL interface, which improves the electron extraction properties at the cathode. In addition, both amino functional groups can induce self-doping to the WSCPs, although by different doping mechanisms, which leads to highly conductive ETLs with reduced ohmic loss for electron transport and extraction. Ultimately, PSCs based on the self-doped WSCP ETLs exhibit significantly improved device performance, yielding PCEs as high as 9.7% and 10.11% for PTB7-Th/PC71BM and PffBT4T-2OD/PC71BM systems, respectively. More importantly, with PffBT4T-2OD/PC71BM BHJ as an active layer, a prominent PCE of over 8% was achieved even when a thick ETL of 100 nm was used. To the best of our knowledge, this is the highest efficiency demonstrated for PSCs with a thick interlayer and light-harvesting layer, which are important criteria for eventually making

  5. Preparative separation of polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin coupled with preparative high performance liquid chromatography.

    PubMed

    Li, Aifeng; Xuan, Hongzhuan; Sun, Ailing; Liu, Renmin; Cui, Jichun

    2016-02-15

    In this study, a preparative separation method was developed for isolation of eleven polyphenols from water-soluble fraction of Chinese propolis using macroporous absorptive resin (MAR) coupled with preparative high performance liquid chromatography (PHPLC). Water-soluble fraction of Chinese propolis was first "prefractioned" using MAR, which yielded four subfractions. The four subfractions were then isolated by PHPLC with an isocratic elution of methanol-water. Finally, eleven polyphenols were purified from Chinese propolis including caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxy cinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin and galangin. The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. The method developed was simple, effective, rapid, scalable and economical, and it was a promising basis for large-scale preparation of multiple components from natural products. PMID:26807704

  6. Water-soluble dietary fibers and cardiovascular disease.

    PubMed

    Theuwissen, Elke; Mensink, Ronald P

    2008-05-23

    One well-established way to reduce the risk of developing cardiovascular disease (CVD) is to lower serum LDL cholesterol levels by reducing saturated fat intake. However, the importance of other dietary approaches, such as increasing the intake of water-soluble dietary fibers is increasingly recognized. Well-controlled intervention studies have now shown that four major water-soluble fiber types-beta-glucan, psyllium, pectin and guar gum-effectively lower serum LDL cholesterol concentrations, without affecting HDL cholesterol or triacylglycerol concentrations. It is estimated that for each additional gram of water-soluble fiber in the diet serum total and LDL cholesterol concentrations decrease by -0.028 mmol/L and -0.029 mmol/L, respectively. Despite large differences in molecular structure, no major differences existed between the different types of water-soluble fiber, suggesting a common underlying mechanism. In this respect, it is most likely that water-soluble fibers lower the (re)absorption of in particular bile acids. As a result hepatic conversion of cholesterol into bile acids increases, which will ultimately lead to increased LDL uptake by the liver. Additionally, epidemiological studies suggest that a diet high in water-soluble fiber is inversely associated with the risk of CVD. These findings underlie current dietary recommendations to increase water-soluble fiber intake. PMID:18302966

  7. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Altieri, K. E.; Hastings, M. G.; Peters, A. J.; Sigman, D. M.

    2011-11-01

    Atmospheric water soluble organic nitrogen (WSON) is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties, and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W), which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2455 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+), CHON compounds that contained sulfur (CHONS+), CHON compounds that contained phosphorous (CHONP+), CHON compounds that contained both sulfur and phosphorous (CHONSP+), and compounds that contained only carbon, hydrogen, and nitrogen (CHN+). No organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March) which have anthropogenic air mass origins and samples collected during the warm season (April to September) with remote marine air mass origins. This, in conjunction with patterns identified in van Krevelen

  8. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Altieri, K. E.; Hastings, M. G.; Peters, A. J.; Sigman, D. M.

    2012-04-01

    Atmospheric water soluble organic nitrogen (WSON) is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W), which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2281 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+), CHON compounds that contained sulfur (CHONS+), CHON compounds that contained phosphorus (CHONP+), CHON compounds that contained both sulfur and phosphorus (CHONSP+), and compounds that contained only carbon, hydrogen, and nitrogen (CHN+). Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Despite their prevalence in continental rainwater, no organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March) which have anthropogenic air mass origins and samples collected during the warm season (April to September) with remote marine air mass origins. This, in

  9. Highly Water-soluble, Near-infrared Emissive BODIPY Polymeric Dye Bearing RGD Peptide Residues for Cancer Imaging

    PubMed Central

    Zhu, Shilei; Zhang, Jingtuo; Janjanam, Jagadeesh; Bi, Jianheng; Vegesna, Giri; Tiwari, Ashutosh; Luo, Fen-Tair; Wei, Jianjun

    2012-01-01

    Near-infrared emissive BODIPY polymeric dye bearing cancer-homing cyclic arginine-glycine-aspartic acid (RGD) peptide residues (polymer B) was prepared by post-polymerization functionalization of BODIPY polymeric dye bearing bromo groups through tetra(ethylene glycol tethered spacers (polymer A) with thiol-functionalized RGD cancer-homing peptide through thioether bonds under a mild basic condition. Polymer B possesses excellent water solubility, good photostability, biocompatibility and resistance to nonspecific interactions to normal endothelial cells, and can efficiently detect breast tumor cells through specific cooperative binding of cancer-homing RGD peptides to αVβ3 integrins of cancer cells while its parent polymer Awith outRGD residues fails to target cancer cells. PMID:23245906

  10. Highly water-soluble, near-infrared emissive BODIPY polymeric dye bearing RGD peptide residues for cancer imaging.

    PubMed

    Zhu, Shilei; Zhang, Jingtuo; Janjanam, Jagadeesh; Bi, Jianheng; Vegesna, Giri; Tiwari, Ashutosh; Luo, Fen-Tair; Wei, Jianjun; Liu, Haiying

    2013-01-01

    Near-infrared emissive BODIPY polymeric dye bearing cancer-homing cyclic arginine-glycine-aspartic acid (RGD) peptide residues (polymer B) was prepared by post-polymerization functionalization of BODIPY polymeric dye bearing bromo groups through tetra(ethylene glycol) tethered spacers (polymer A) with thiol-functionalized RGD cancer-homing peptide through thioether bonds under a mild basic condition. Polymer B possesses excellent water solubility, good photostability, biocompatibility and resistance to nonspecific interactions to normal endothelial cells, and can efficiently detect breast tumor cells through specific cooperative binding of cancer-homing RGD peptides to αvβ3 integrins of cancer cells while its parent polymer A without RGD residues fails to target cancer cells. PMID:23245906

  11. High-field FT-ICR-MS and aromaticity equivalent approach for structural identification of water soluble organic compounds (WSOC)

    NASA Astrophysics Data System (ADS)

    Harir, Mourad; Yassine, Mahmoud M.; Dabek-Zlotorzynska, Ewa; Hertkorn, Norbert; Schmitt-Kopplin, Philippe

    2015-04-01

    Organic aerosol (OA) makes up a large and often dominant fraction, (20 to 90%) of the submicron atmospheric particulate mass, and its effects are becoming increasingly important in determining climatic and health effects of atmospheric aerosols. Despite the abundance of OA, our understanding of the sources, formation processes and atmospheric properties of OA is limited. Atmospheric OA has both primary (directly emitted) and secondary (formed in the atmosphere from precursor gases) sources, which can be natural (e.g. vegetation) and/or anthropogenic (e.g. fossil-based vehicle exhaust or biomass burning). A significant fraction of OA contains as much as 20-70% of water soluble organic compounds (WSOC). The WSOC fraction is a very complex mixture of low volatility, polyfunctional aliphatic and aromatic compounds containing carboxyl, alcohol, carbonyl, sulfo, nitro, and other functionalities. This high degree of chemical complexity of atmospheric organics has inspired a number of sophisticated approaches that are capable of identifying and detecting a variety of different analytes in OA. Accordingly, one of the most challenging areas of atmospheric particulate matter (PM) analysis is to comprehend the molecular complexity of the OA, especially WSOC fraction, a significant component of atmospheric fine PM (PM2.5). The sources of WSOC are not well understood, especially the relative contributions of primary vs. secondary organic aerosol. Therefore, the molecular characterization of WSOC is important because it allows gaining insight into aerosol sources and underlying mechanisms of secondary organic aerosols (SOA) formation and transformation. In this abstract, molecular characterization of WSOC was achieved using high-field mass spectrometry FT-ICR-MS and aromaticity equivalent approach. Aromaticity equivalent (Xc), defined recently as a new parameter calculated from the assigned molecular formulas (complementary to the aromaticity index [1]), is introduced to improve

  12. A water-soluble luminescence oxygen sensor.

    PubMed

    Castellano, F N; Lakowicz, J R

    1998-02-01

    We developed a water-soluble luminescent probe for dissolved oxygen. This probe is based on (Ru[dpp(SO3Na)2]3) cl2, which is a sulfonated analogue of the well-known oxygen probe (Ru[dpp]3)cl2. The compound dpp is 4,7-diphenyl-1,10-phenanthroline and dpp(SO3Na)2 is a disulfonated derivative of the same ligand. In aqueous solution in the absence of oxygen (Ru[dpp(SO3Na)2]3)cl2 displays a lifetime of 3.7 microseconds that decreases to 930 ns on equilibrium with air and 227 ns on equilibrium with 100% oxygen. The Stern-Volmer quenching constant is 11,330 M-1. This high oxygen-quenching constant means that the photoluminescence of Ru(dpp[SO3Na]2)3cl2 is 10% quenched at an oxygen concentration of 8.8 x 10(-6) M, or equilibration with 5.4 torr of oxygen. The oxygen probe dissolved in water displays minimal interactions with lipid vesicles composed of dipalmityl-L-alpha-phosphatidyl glycerol but does appear to interact with human serum albumin. The absorption maximum near 480 nm, long lifetime and large Stokes' shift allow this probe to be used with simple instrumentation based on a light-emitting diode light source, allowing low-cost oxygen sensing in aqueous solutions. To the best of our knowledge this is the first practical water-soluble oxygen sensor. PMID:9487796

  13. A facile synthesis of highly water-soluble, core-shell organo-silica nanoparticles with controllable size via sol-gel process.

    PubMed

    Du, Hongwei; Hamilton, Paul D; Reilly, Matthew A; d'Avignon, André; Biswas, Pratim; Biswas, Pramit; Ravi, Nathan

    2009-12-15

    A series of highly water-soluble organo-silica nanoparticles, ranging from 2 to 10nm in diameter, were synthesized by the cohydrolysis and copolycondensation reactions. omega-methoxy(polyethyleneoxy)propyltrimethoxysilane (PEG6-9) and hydroxymethyltriethoxysilane (HMTEOS) mixtures were catalyzed by sodium hydroxide in the presence of surfactant benzethonium chloride (BTC) with various ratios of PEG6-9/HMTEOS at room temperature. The synthesized organo-silica nanoparticles possess a core-shell structure with a core of organo-silica resulting from HMTEOS and a monolayer shell of PEG6-9. The chemo-physical characteristics of the particles were studied by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, (29)Si nuclear magnetic resonance (NMR), dynamic light scattering (DLS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The molecular weight and particle size of the particles increased with increasing HMTEOS molar ratios. The richest HMTEOS composition for the water-soluble particles was found to be HMTEOS:PEG6-9=80:20, where the particles had a 6nm diameter core and a 0.8nm thick shell. We propose that these water-soluble organo-silica nanoparticles will be suitable for biomedical applications. PMID:19783256

  14. High time-resolution chemical characterization of the water-soluble fraction of ambient aerosols with PILS-TOC-IC and AMS

    NASA Astrophysics Data System (ADS)

    Timonen, H.; Aurela, M.; Carbone, S.; Saarnio, K.; Saarikoski, S.; Mäkelä, T.; Worsnop, D. R.; Kulmala, M.; Kerminen, V.-M.; Hillamo, R.

    2010-04-01

    A particle-into-liquid sampler (PILS) was coupled with a total organic carbon analyzer (TOC) and two ion chromatographs (IC) to enable high time-resolution measurements of water-soluble ions and water-soluble organic carbon (WSOC) by a single sampling and analytical set-up. The new high time-resolution measurement system, the PILS-TOC-IC, was able to provide essential chemical and physical information about fast changes in composition, concentrations and likely sources of the water-soluble fraction of atmospheric aerosol. The concentrations of major water-soluble ions and WSOC were measured by the PILS-TOC-IC system from 25 April to 28 May 2009. The data of the PILS-TOC-IC setup was completed with the data from the High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) data measured from 25 April to 8 May 2009. The measured water-soluble particulate organic matter (WSPOM) concentration varied typically from 0.10 to 8.8 µg m-3 (on average 1.5 µg m-3). The WSPOM contributed on average 51% to particulate organic matter (POM) measured with the AMS. The correlation between the data of all the online measurement devices (AMS, PILS-TOC-IC, semicontinous EC/OC carbon analyzer and TEOM) was excellent. For sulfate, nitrate and ammonium the correlations between the PILS-TOC-IC and AMS were 0.93, 0.96 and 0.96, respectively. The correlation between WSPOM and POM was also strong (r=0.88). The identified sources of WSPOM were long-range transported biomass burning and secondary organic aerosol (SOA) formation. The WSPOM/POM-ratio followed the trends of the ambient daytime temperature. The temperature dependency of the WSPOM/POM-ratio suggest that in the absence of emissions from biomass burning, the SOA formation was the prevailing source for WSPOM. WSPOM produced in biomass burning was clearly correlated with carbon monoxide, confirming that biomass burning was producing primary WSPOM. In addition, elevated oxalate and potassium concentrations were measured

  15. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    2002-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  16. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, B.F.; Robison, T.W.; Gohdes, J.W.

    1999-04-06

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  17. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    1999-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  18. Correlation of octanol/water solubility ratios and partition coefficients

    SciTech Connect

    Pinsuwan, S.; Li, A.; Yalkowsky, S.H.

    1995-05-01

    The partition coefficient between octanol and water in an important physicochemical parameter for characterizing the lipophilicity or hydrophobicity of a compound and it is used in many fields, especially in the environmental and pharmaceutical sciences. The octanol/water solubility ratio (S{sub o}/S{sub W}) was found to be highly correlated with the octanol/water partition coefficient (K{sub ow}) of 82 pharmaceutically and environmentally relevant compounds. The solubility ratio gives comparable estimates to that of the group contribution (log P(calcd)) method for estimating the partition coefficient of the compounds used in this study.

  19. Solubility Enhancement of a Poorly Water Soluble Drug by Forming Solid Dispersions using Mechanochemical Activation

    PubMed Central

    Rojas-Oviedo, I.; Retchkiman-Corona, B.; Quirino-Barreda, C. T.; Cárdenas, J.; Schabes-Retchkiman, P. S.

    2012-01-01

    Mechanochemical activation is a practical cogrinding operation used to obtain a solid dispersion of a poorly water soluble drug through changes in the solid state molecular aggregation of drug-carrier mixtures and the formation of noncovalent interactions (hydrogen bonds) between two crystalline solids such as a soluble carrier, lactose, and a poorly soluble drug, indomethacin, in order to improve its solubility and dissolution rate. Samples of indomethacin and a physical mixture with a weight ratio of 1:1 of indomethacin and lactose were ground using a high speed vibrating ball mill. Particle size was determined by electron microscopy, the reduction of crystallinity was determined by calorimetry and transmission electron microscopy, infrared spectroscopy was used to find evidence of any interactions between the drug and the carrier and the determination of apparent solubility allowed for the corroboration of changes in solubility. Before grinding, scanning electron microscopy showed the drug and lactose to have an average particle size of around 50 and 30 μm, respectively. After high speed grinding, indomethacin and the mixture had a reduced average particle size of around 5 and 2 μm, respectively, showing a morphological change. The ground mixture produced a solid dispersion that had a loss of crystallinity that reached 81% after 30 min of grinding while the drug solubility of indomethacin within the solid dispersion increased by 2.76 fold as compared to the pure drug. Drug activation due to hydrogen bonds between the carboxylic group of the drug and the hydroxyl group of lactose as well as the decrease in crystallinity of the solid dispersion and the reduction of the particle size led to a better water solubility of indomethacin. PMID:23798775

  20. Fluorite solubility equilibria in selected geothermal waters

    USGS Publications Warehouse

    Nordstrom, D.K.; Jenne, E.A.

    1977-01-01

    Calculation of chemical equilibria in 351 hot springs and surface waters from selected geothermal areas in the western United States indicate that the solubility of the mineral fluorite, CaF2, provides an equilibrium control on dissolved fluoride activity. Waters that are undersaturated have undergone dilution by non-thermal waters as shown by decreased conductivity and temperature values, and only 2% of the samples are supersaturated by more than the expected error. Calculations also demonstrate that simultaneous chemical equilibria between the thermal waters and calcite as well as fluorite minerals exist under a variety of conditions. Testing for fluorite solubility required a critical review of the thermodynamic data for fluorite. By applying multiple regression of a mathematical model to selected published data we have obtained revised estimates of the pK (10,96), ??Gof (-280.08 kcal/mole), ??Hof (-292.59 kcal/mole), S?? (16.39 cal/deg/mole) and CoP (16.16 cal/deg/mole) for CaF2 at 25??C and 1 atm. Association constants and reaction enthalpies for fluoride complexes with boron, calcium and iron are included in this review. The excellent agreement between the computer-based activity products and the revised pK suggests that the chemistry of geothermal waters may also be a guide to evaluating mineral solubility data where major discrepancies are evident. ?? 1977.

  1. Characterization of Soluble Organics in Produced Water

    SciTech Connect

    Bostick, D.T.

    2002-01-16

    Soluble organics in produced water and refinery effluents represent treatment problems for the petroleum industry. Neither the chemistry involved in the production of soluble organics nor the impact of these chemicals on total effluent toxicity is well understood. The U.S. Department of Energy provides funding for Oak Ridge National Laboratory (ORNL) to support a collaborative project with Shell, Chevron, Phillips, and Statoil entitled ''Petroleum and Environmental Research Forum project (PERF 9844: Manage Water-Soluble Organics in Produced Water''). The goal of this project, which involves characterization and evaluation of these water-soluble compounds, is aimed at reducing the future production of such contaminants. To determine the effect that various drilling conditions might have on water-soluble organics (WSO) content in produced water, a simulated brine water containing the principal inorganic components normally found in Gulf of Mexico (GOM) brine sources was prepared. The GOM simulant was then contacted with as-received crude oil from a deep well site to study the effects of water cut, produced-water pH, salinity, pressure, temperature, and crude oil sources on the type and content of the WSO in produced water. The identities of individual semivolatile organic compounds (SVOCs) were determined in all as-received crude and actual produced water samples using standard USEPA Method (8270C) protocol. These analyses were supplemented with the more general measurements of total petroleum hydrocarbon (TPH) content in the gas (C{sub 6}-C{sub 10}), diesel (C{sub 10}-C{sub 20}), and oil (C{sub 20}-C{sub 28}) carbon ranges as determined by both gas chromatographic (GC) and infrared (IR) analyses. An open liquid chromatographic procedure was also used to differentiate the saturated hydrocarbon, aromatic hydrocarbon, and polar components within the extractable TPH. Inorganic constituents in the produced water were analyzed by ion-selective electrodes and inductively

  2. Water-soluble derivatives of 1 -tetrahydrocannabinol.

    PubMed

    Zitko, B A; Howes, J F; Razdan, R K; Dalzell, B C; Dalzell, H C; Sheehan, J C; Pars, H G; Dewey, W L; Harris, L S

    1972-08-01

    Delta1-Tetrahydrocannabinol, which is resinous and insoluble in water and therefore difficult to study pharmacologically, can be converted to a watersoluble derivative without loss of its biological activity. This has been achieved by preparing esters bearing a nitrogen moiety with the use of carbodiimide as the condensing agent. The availability of such water-soluble derivatives will allow the evaluation of Delta1-tetrahydrocannabinol in self-administration studies in monkeys for its addiction liability potential in man. This technique of water solubilization is also applicable to other compounds of chemical and biological significance. PMID:5043146

  3. Soaking Hay in Water to Reduce Soluble Carbohydrate Concentrations Prior to Horse Feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Administering high concentrations of fructan to horses has resulted in laminitis. Cool season grasses accumulate fructan, which is estimated as the difference between water soluble carbohydrates (WSC; sucrose, fructose, glucose, fructans) and ethanol soluble carbohydrates (ESC; sucrose, fructose, gl...

  4. Water-soluble perylenediimides: design concepts and biological applications.

    PubMed

    Sun, Mengmeng; Müllen, Klaus; Yin, Meizhen

    2016-03-21

    Water-soluble perylenediimides (PDIs) with high fluorescence intensity, photostability and biocompatibility have been successfully prepared and applied in the biological field. In this tutorial review, we briefly focus on the synthetic strategies for the preparation of water-soluble PDIs by incorporating ionic or non-ionic substituents with multiple polar groups into the bay-region, imide- or ortho-positions of PDIs. These ionic/non-ionic substituents can suppress π-π aggregation and shield the inner perylene chromophores, thus contributing to the water solubility which is essential for biological applications. The optical properties, absorption and emission maxima above 500 nm, minimize the autofluorescence background of cells and provide access to imaging in living cells. The biological applications of water-soluble PDIs are discussed from simple (basic) to complex (advanced) processes, including biosensing in vitro studies, imaging and gene/drug delivering in living cells, tissues and the whole body. The promising future of designed multi-functional water-soluble PDIs will be highlighted in this review. PMID:26797049

  5. Water-soluble iridium phosphorescent complexes for OLED applications

    NASA Astrophysics Data System (ADS)

    Eum, Min-Sik; Yoon, Heekoo; Kim, Tae Hyung

    2012-09-01

    Newly prepared water-soluble iridium phosphorescent complexes, trans-[Ir(ppy)(PAr3)2(H)L]0,+ (ppy = bidentate 2-phenylpyridinato anionic ligand; L= Cl (1), CO (2), CN- (3); H being trans to the nitrogen of ppy ligand; PAr3 (TPPTS) = P(m-C6H4SO3Na)3), have been synthesized and characterized. Those complexes containing water-soluble phosphine ligands can emit any color region as altering cyclometalated ligands in aqueous media with high quantum efficiencies. Even though these water-soluble phosphorescent iridium complexes can be the sensing probe for toxic CO gas and CN anion, they will be capable of promising materials in the solution processible OLED applications.

  6. Water-soluble titanium alkoxide material

    DOEpatents

    Boyle, Timothy J.

    2010-06-22

    A water soluble, water stable, titanium alkoxide composition represented by the chemical formula (OC.sub.6H.sub.6N).sub.2Ti(OC.sub.6H.sub.2(CH.sub.2N(CH.sub.3).sub.2).sub- .3-2,4,6).sub.2 with a theoretical molecular weight of 792.8 and an elemental composition of 63.6% C, 8.1% H, 14.1% N, 8.1% O and 6.0% Ti.

  7. Solubility of 2,4,6-trinitrotoluene (TNT) in water

    SciTech Connect

    Ro, K.S.; Venugopal, A.; Adrian, D.D.; Constant, D.; Valsaraj, K.T.; Thibodeaux, L.J.; Qaisi, K.; Roy, D.

    1996-07-01

    Current literature values of 2,4,6-trinitrotoluene (TNT) solubility in water vary widely from 100 to 200 mg/L at room temperature. The authors investigated the effects of temperature and pH on the solubility of both reference TNT and field neat TNT obtained from the Alabama Army Ammunition Plant (AAAP), Childersburg, AL. The TNT solubility determined from this study was significantly lower than that of Taylor and Rinkenbach, which was cited by several reference chemical handbooks and articles. However, the values reported by the Merck Index and the Lange`s Handbook of Chemistry compared well with the authors` values. TNT solubility dropped rapidly as the pH increased. Three unknown HPLC peaks were observed at high pH, indicating a possibility of forming unknown transformation products. Both reference and field neat TNT solubility agreed well. A semiempirical solubility correlation was developed to predict the solubility of TNT at a temperature range from 6 C to 42 C.

  8. Determination of four water-soluble compounds in Salvia miltiorrhiza Bunge by high-performance liquid chromatography with a coulometric electrode array system.

    PubMed

    Ma, Lijuan; Zhang, Xuezhu; Guo, Hui; Gan, Yiru

    2006-04-01

    A method has been developed to determine the four water-soluble components-Danshensu (I), protocatechuic acid (II), protocatechuic aldehyde (III) and salvianolic acid B (IV) in Chinese medicine plant Salvia miltiorrhiza Bunge using high-performance liquid chromatography with a coulometric electrode array detection (HPLC-CEAD) system. Heat reflux extraction was used to pretreat the sample. This analysis was carried on a column of Hypersil C18 (250 mm x 4.6 mm, 5 microm) with a mobile phase of sodium acetate (pH 2.5, 50 mM) and acetonitrile in gradient mode. An ESA electrochemical detector monitored the four compounds. Potentials of four electrodes in series were set at 100, 150, 200 and 250 mV, respectively. Optimization of the pH of mobile phase and the proportion of acetonitrile were also performed. Calibration curve showed good linearity with correlation coefficients (r) more than 0.9937. Average recoveries of the four compounds were more than 92% and relative standard deviations were less than 6.6%. This method appeared to be stable, sensitive and reproducible for determination of the four water-soluble compounds in Chinese medicine plant S. miltiorrhiza Bunge. PMID:16500160

  9. Spectroscopic and Photochemical Properties of Water-Soluble Fullerenol

    EPA Science Inventory

    Fullerenol, a hydroxylated form of C60-fullerene, is of potential environmental and biological significance due to its buckyball structure, hydroxyl groups and high water solubility. Although fullerenol is known to be an efficient triplet photosensitizer, little is known about it...

  10. One-step solvothermal synthesis of highly water-soluble, negatively charged superparamagnetic Fe3O4 colloidal nanocrystal clusters

    NASA Astrophysics Data System (ADS)

    Gao, Jining; Ran, Xinze; Shi, Chunmeng; Cheng, Humin; Cheng, Tianmin; Su, Yongping

    2013-07-01

    Highly charged hydrophilic superparamagnetic Fe3O4 colloidal nanocrystal clusters with an average diameter of 195 nm have been successfully synthesized using a modified one-step solvothermal method. Anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium salt containing both sulfonate and carboxylate groups was used as the stabilizer. The clusters synthesized under different experimental conditions were characterized with transmission electron microscopy and dynamic light scattering; it was found that the size distribution and water dispersity were significantly affected by the concentration of the polyelectrolyte stabilizer and iron sources in the reaction mixtures. A possible mechanism involving novel gel-like large molecular networks that confined the nucleation and aggregation process was proposed and discussed. The colloidal nanocrystal clusters remained negatively charged in the experimental pH ranges from 2 to 11, and also showed high colloidal stability in phosphate buffered saline (PBS) and ethanol. These highly colloidal stable superparamagnetic Fe3O4 clusters could find potential applications in bioseparation, targeted drug delivery, and photonics.Highly charged hydrophilic superparamagnetic Fe3O4 colloidal nanocrystal clusters with an average diameter of 195 nm have been successfully synthesized using a modified one-step solvothermal method. Anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium salt containing both sulfonate and carboxylate groups was used as the stabilizer. The clusters synthesized under different experimental conditions were characterized with transmission electron microscopy and dynamic light scattering; it was found that the size distribution and water dispersity were significantly affected by the concentration of the polyelectrolyte stabilizer and iron sources in the reaction mixtures. A possible mechanism involving novel gel-like large molecular networks that confined the nucleation and

  11. Soluble high molecular weight polyimide resins

    NASA Technical Reports Server (NTRS)

    Jones, R. J.; Lubowitz, H. R.

    1970-01-01

    High molecular weight polyimide resins have greater than 20 percent /by weight/ solubility in polar organic solvents. They permit fabrication into films, fibers, coatings, reinforced composite, and adhesive product forms. Characterization properties for one typical polyimide resin are given.

  12. Direct Solvent-Derived Polymer-Coated Nitrogen-Doped Carbon Nanodots with High Water Solubility for Targeted Fluorescence Imaging of Glioma.

    PubMed

    Wang, Yi; Meng, Ying; Wang, Shanshan; Li, Chengyi; Shi, Wei; Chen, Jian; Wang, Jianxin; Huang, Rongqin

    2015-08-01

    Cancer imaging requires biocompatible and bright contrast-agents with selective and high accumulation in the tumor region but low uptake in normal tissues. Herein, 1-methyl-2-pyrrolidinone (NMP)-derived polymer-coated nitrogen-doped carbon nanodots (pN-CNDs) with a particle size in the range of 5-15 nm are prepared by a facile direct solvothermal reaction. The as-prepared pN-CNDs exhibit stable and adjustable fluorescence and excellent water solubility. Results of a cell viability test (CCK-8) and histology analysis both demonstrate that the pN-CNDs have no obvious cytotoxicity. Most importantly, the pN-CNDs can expediently enter glioma cells in vitro and also mediate glioma fluorescence imaging in vivo with good contrast via elevated passive targeting. PMID:25808813

  13. Simultaneous detection and quantitation of highly water-soluble herbicides in serum using ion-pair liquid chromatography-tandem mass spectrometry.

    PubMed

    Wang, Kuang-Chuan; Chen, Shih-Ming; Hsu, Jung-Fa; Cheng, Sheaw-Guey; Lee, Ching-Kuo

    2008-12-15

    We report the simultaneous screening of highly polar, water-soluble, and less-volatile herbicides, including glyphosate, glufosinate, paraquat, and diquat, in serum using liquid chromatography-mass spectrometry. The herbicides were separated by solid-phase extraction using a Strata-XC cartridge. A heptafluorobutyric acid solution was chosen as the mobile phase for ion-pair liquid chromatography. Mass spectrometry was used for analysis and was optimized for operation in the positive mode for all analytes. The serum specimens were screened for the presence of the herbicides at the following concentrations: 5 ng/mL for glyphosate, 2 ng/mL for glufosinate, 1 ng/mL for diquat, and 5 ng/mL for paraquat. This is the first report on the simultaneous detection of these compounds. PMID:19022710

  14. Ice nucleation by water-soluble macromolecules

    NASA Astrophysics Data System (ADS)

    Pummer, B. G.; Budke, C.; Augustin-Bauditz, S.; Niedermeier, D.; Felgitsch, L.; Kampf, C. J.; Huber, R. G.; Liedl, K. R.; Loerting, T.; Moschen, T.; Schauperl, M.; Tollinger, M.; Morris, C. E.; Wex, H.; Grothe, H.; Pöschl, U.; Koop, T.; Fröhlich-Nowoisky, J.

    2015-04-01

    Cloud glaciation is critically important for the global radiation budget (albedo) and for initiation of precipitation. But the freezing of pure water droplets requires cooling to temperatures as low as 235 K. Freezing at higher temperatures requires the presence of an ice nucleator, which serves as a template for arranging water molecules in an ice-like manner. It is often assumed that these ice nucleators have to be insoluble particles. We point out that also free macromolecules which are dissolved in water can efficiently induce ice nucleation: the size of such ice nucleating macromolecules (INMs) is in the range of nanometers, corresponding to the size of the critical ice embryo. As the latter is temperature-dependent, we see a correlation between the size of INMs and the ice nucleation temperature as predicted by classical nucleation theory. Different types of INMs have been found in a wide range of biological species and comprise a variety of chemical structures including proteins, saccharides, and lipids. Our investigation of the fungal species Acremonium implicatum, Isaria farinosa, and Mortierella alpina shows that their ice nucleation activity is caused by proteinaceous water-soluble INMs. We combine these new results and literature data on INMs from fungi, bacteria, and pollen with theoretical calculations to develop a chemical interpretation of ice nucleation and water-soluble INMs. This has atmospheric implications since many of these INMs can be released by fragmentation of the carrier cell and subsequently may be distributed independently. Up to now, this process has not been accounted for in atmospheric models.

  15. Thermodynamics of Highly Supersaturated Aqueous Solutions of Poorly Water-Soluble Drugs-Impact of a Second Drug on the Solution Phase Behavior and Implications for Combination Products.

    PubMed

    Trasi, Niraj S; Taylor, Lynne S

    2015-08-01

    There is increasing interest in formulating combination products that contain two or more drugs. Furthermore, it is also common for different drug products to be taken simultaneously. This raises the possibility of interactions between different drugs that may impact formulation performance. For poorly water-soluble compounds, the supersaturation behavior may be a critical factor in determining the extent of oral absorption. The goal of the current study was to evaluate the maximum achievable supersaturation for several poorly water-soluble compounds alone, and in combination. Model compounds included ritonavir, lopinavir, paclitaxel, felodipine, and diclofenac. The "amorphous solubility" for the pure drugs was determined using different techniques and the change in this solubility was then measured in the presence of differing amounts of a second drug. The results showed that "amorphous solubility" of each component in aqueous solution is substantially decreased by the second component, as long as the two drugs are miscible in the amorphous state. A simple thermodynamic model could be used to predict the changes in solubility as a function of composition. This information is of great value when developing co-amorphous or other supersaturating formulations and should contribute to a broader understanding of drug-drug physicochemical interactions in in vitro assays as well as in the gastrointestinal tract. PMID:26059413

  16. Solubility of magnesium carbonate in natural waters

    USGS Publications Warehouse

    Wells, R.C.

    1915-01-01

    (1) Under atmospheric conditions it appears possible to attain practically the same state in a solution saturated with MgCO33H2O, whether one starts with a solution containing an excess of magnesium bicarbonate or with the pure trihydrate and water, but the adjustment occurs very slowly. The solution finally contains 0.36 g. magnesium and 1.01 g. carbon dioxide per liter at 20??. (2) The solubility found for magnesite, however, is much smaller, viz., 0.02 g. magnesium and 0.07 g. carbon dioxide per liter. (3) Certain natural waters, freely exposed to the atmosphere, appear to be supersaturated with respect to magnesite but none approaches very closely to the point of saturation of the trihydrate MgCO3.3H2O.

  17. Water soluble complexes of carotenoids with arabinogalactan.

    PubMed

    Polyakov, Nikolay E; Leshina, Tatyana V; Meteleva, Elizaveta S; Dushkin, Alexander V; Konovalova, Tatyana A; Kispert, Lowell D

    2009-01-01

    We present the first example of water soluble complexes of carotenoids. The stability and reactivity of carotenoids in the complexes with natural polysaccharide arabinogalactan were investigated by different physicochemical techniques: optical absorption, HPLC, and pulsed EPR spectroscopy. Compared to pure carotenoids, polysaccharide complexes of carotenoids showed enhanced photostability by a factor of 10 in water solutions. A significant decrease by a factor of 20 in the reactivity toward metal ions (Fe(3+)) and reactive oxygen species in solution was detected. On the other hand, the yield and stability of carotenoid radical cations photoproduced on titanium dioxide (TiO(2)) were greatly increased. EPR measurements demonstrated efficient charge separation on complex-modified TiO(2) nanoparticles (7 nm). Canthaxanthin radical cations are stable for approximately 10 days at room temperature in this system. The results are important for a variety of carotenoid applications, in the design of artificial light-harvesting, photoredox, and catalytic devices. PMID:19061372

  18. Fabrication of flexible conductive graphene thin films based on high water-soluble sulfonated-triazine non-covalent functionalized graphene

    NASA Astrophysics Data System (ADS)

    Liu, Yu; Guang, Shanyi; Su, Xinyan; Xu, Hongyao

    2013-12-01

    We report a facile and scalable fabrication of flexible conductive graphene thin films via a vacuum filtration method based on high water-soluble sulfonated-triazine non-covalent functionalized graphene colloid (STGNS). A novel sulfonated triazine (ST) molecule was synthesized using a one-step method to improve the dispersion stability of graphene during the chemical reduction. AFM image of STGNS sheets showed the STGNS is individual dispersion of graphene sheets in water. FTIR, and UV-vis revealed ST molecules were successfully loaded onto graphene sheets by hydrogen bonding anchoring and π-π stacking. It was found that the dark homogeneous suspension of the STGNS with concentration up to 4.5 mg mL-1 can remain stable with no visible precipitate for more than 6 months. The high watersoluble individually dispersed graphene colloid facilitated large-scale fabrication of flexible conductive graphene films with different thickness by adjusting the content of STGNS. The obtained graphene films exhibited a sheet resistance as low as ca. 5.6 KΩ-1 with 78% transparency at 550 nm.

  19. The selective synthesis of water-soluble highly luminescent CdTe nanoparticles and nanorods: The influence of the precursor Cd/Te molar ratio

    NASA Astrophysics Data System (ADS)

    Deng, Da-Wei; Qin, Yuan-Bin; Yang, Xi; Yu, Jun-Sheng; Pan, Yi

    2006-11-01

    In this report, we initially systematically investigated the influence of the precursor Cd/Te molar ratio on the morphology of water-soluble thiol-stabilized CdTe nanocrystals. By only changing the precursor Cd/Te molar ratio, highly luminescent CdTe nanoparticles (NPs) and nanorods (NRs) can be prepared selectively in the presence of the same concentration single ligand ( L-cysteine or thioglycolic acid) system. A high precursor Cd/Te molar ratio leads to isotropic spherical growth, whereas a low Cd/Te molar ratio promotes the linear self-assembly of NPs into NRs. Thus, a new efficient strategy has been developed in aqueous phase to prepare selectively highly luminescent dot- or rod-shaped CdTe nanocrystals in single ligand system. Then, we further explored the influence of the properties of initial CdTe dispersions with different luminescence maxima on the formation of NRs. The experiment results revealed that the formation of CdTe NRs is also dependent on the properties of initial CdTe dispersions. CdTe NPs with short wavelength emission (˜520-550 nm) can self-assemble directly into high quality CdTe NRs after storage at room temperature.

  20. High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the mountaintop aerosols over the North China Plain during wheat burning season

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Tachibana, E.; Okuzawa, K.; Aggarwal, S. G.; Kanaya, Y.; Wang, Z. F.

    2013-08-01

    Aerosol (TSP) samples were collected at the summit of Mount Tai (elevation: 1534 m a.s.l., 36.25° N, 117.10° E) located in the North China Plain using a high-volume air sampler and pre-combusted quartz filters. Sampling was conducted on day/night or 3 h basis in the period from 29 May to 28 June 2006 during the field burning of wheat straw residue and the post-burning season. The filter samples were analyzed for low-molecular-weight dicarboxylic acids, ketoacids and α-dicarbonyls using capillary gas chromatography (GC) and GC-MS employing water extraction and butyl ester derivatization. Molecular distributions of dicarboxylic acids (C2-C11, 220-6070 ng m-3) were characterized by a predominance of oxalic (C2) acid (105-3920 ng m-3) followed by succinic (C4) or malonic (C3) acid. Unsaturated aliphatic diacids, including maleic (M), isomaleic (iM) and fumaric (F) acids, were also detected together with aromatic diacids (phthalic, isophthalic and terephthalic acids). ω-oxocarboxylic acids (C2-C9, 24-610 ng m-3) were detected as the second most abundant compound class with the predominance of glyoxylic acid (11-360 ng m-3), followed by α-ketoacid (pyruvic acid, 3-140 ng m-3) and α-dicarbonyls (glyoxal, 1-230 ng m-3 and methylglyoxal, 2-120 ng m-3). We found that these levels (>6000 ng m-3 for diacids) are several times higher than those reported in Chinese megacities at ground levels. The concentrations of diacids increased from late May to early June, showing a maximum on 7 June, and then significantly decreased during the period 8-11 June, when the wind direction shifted from southerly to northerly. Similar temporal trends were found for ketocarboxylic acids and α-dicarbonyls as well as total carbon (TC) and water-soluble organic carbon (WSOC). The temporal variations of water-soluble organics were interpreted by the direct emission from the field burning of agricultural wastes (wheat straw) in the North China Plain and the subsequent photochemical oxidation of

  1. High abundances of water-soluble dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls in the mountain aerosols over the North China Plain during wheat burning season

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Tachibana, E.; Okuzawa, K.; Aggarwal, S. G.; Kanaya, Y.; Wang, Z. F.

    2013-02-01

    Aerosol (TSP) samples were collected at the summit of Mount Tai (elevation: 1534 m a.s.l., 36.25° N; 117.10° E) located in the North China Plain using a high-volume air sampler and pre-combusted quartz filters. Sampling was conducted on day/night or 3 h basis in the period from 29 May to 28 June 2006 during the field burning of wheat straw residue and the post-burning season. The filter samples were analyzed for low molecular weight dicarboxylic acids, ketoacids and α-dicarbonyls using capillary gas chromatography (GC) and GC-MS employing water extraction and butyl ester derivatization. Dicarboxylic acids (C2-C11, 220-6070 ng m-3) were characterized by a predominance of oxalic (C2) acid (105-3920 ng m-3) followed by succinic (C4) or malonic (C3) acid. Unsaturated aliphatic diacids, including maleic (M), isomaleic (iM) and fumaric (F) acid, were also detected together with aromatic diacids (phthalic, iso-phthalic and tere-phthalic acids). ω-Oxocarboxylic acids (C2-C9, 24-610 ng m-3) were detected as the second most abundant compound class with the predominance of glyoxylic acid (11-360 ng m-3), followed by α-ketoacid (pyruvic acid, 3-140 ng m-3) and α-dicarbonyls (glyoxal, 1-230 ng m-3 and methylglyoxal, 2-120 ng m-3). We found that these levels (> 6000 ng m-3 for diacids) are several times higher than those reported in Chinese megacities at ground levels. The concentrations of diacids increased from late May to early June showing a maximum on 7 June and then significantly decreased during 8-11 June when the wind direction shifted from northeasterly to northerly. Similar temporal trends were found for ketocarboxylic acids and α-dicarbonyls as well as total carbon (TC) and water-soluble organic carbon (WSOC). The temporal variations of water-soluble organics were interpreted by the direct emission from the field burning products of agricultural wastes (wheat straw) in the North China Plain and the subsequent photochemical oxidation of volatile and semi

  2. RAFT Aqueous Dispersion Polymerization of N-(2-(Methacryloyloxy)ethyl)pyrrolidone: A Convenient Low Viscosity Route to High Molecular Weight Water-Soluble Copolymers

    PubMed Central

    2016-01-01

    RAFT solution polymerization of N-(2-(methacryoyloxy)ethyl)pyrrolidone (NMEP) in ethanol at 70 °C was conducted to produce a series of PNMEP homopolymers with mean degrees of polymerization (DP) varying from 31 to 467. Turbidimetry was used to assess their inverse temperature solubility behavior in dilute aqueous solution, with an LCST of approximately 55 °C being observed in the high molecular weight limit. Then a poly(glycerol monomethacylate) (PGMA) macro-CTA with a mean DP of 63 was chain-extended with NMEP using a RAFT aqueous dispersion polymerization formulation at 70 °C. The target PNMEP DP was systematically varied from 100 up to 6000 to generate a series of PGMA63–PNMEPx diblock copolymers. High conversions (≥92%) could be achieved when targeting up to x = 5000. GPC analysis confirmed high blocking efficiencies and a linear evolution in Mn with increasing PNMEP DP. A gradual increase in Mw/Mn was also observed when targeting higher DPs. However, this problem could be minimized (Mw/Mn < 1.50) by utilizing a higher purity grade of NMEP (98% vs 96%). This suggests that the broader molecular weight distributions observed at higher DPs are simply the result of a dimethacrylate impurity causing light branching, rather than an intrinsic side reaction such as chain transfer to polymer. Kinetic studies confirmed that the RAFT aqueous dispersion polymerization of NMEP was approximately four times faster than the RAFT solution polymerization of NMEP in ethanol when targeting the same DP in each case. This is perhaps surprising because both 1H NMR and SAXS studies indicate that the core-forming PNMEP chains remain relatively solvated at 70 °C in the latter formulation. Moreover, dissolution of the initial PGMA63–PNMEPx particles occurs on cooling from 70 to 20 °C as the PNMEP block passes through its LCST. Hence this RAFT aqueous dispersion polymerization formulation offers an efficient route to a high molecular weight water-soluble polymer in a rather

  3. Preparation of Chitosan and Water-Soluble Chitosan Microspheres via Spray-Drying Method to Lower Blood Lipids in Rats Fed with High-Fat Diets

    PubMed Central

    Tao, Yi; Zhang, Hong-Liang; Hu, Yin-Ming; Wan, Shuo; Su, Zheng-Quan

    2013-01-01

    This experiment aimed to investigate the effects of the chitosan (CTS) and water-soluble chitosan (WSC) microspheres on plasma lipids in male Sprague-Dawley rats fed with high-fat diets. CTS microspheres and WSC microspheres were prepared by the spray-drying technique. Scanning electron microscopy (SEM) micrographs showed that the microspheres were nearly spherical in shape. The mean size of CTS microspheres was 4.07 μm (varying from 1.50 to 7.21 μm) and of WSC microspheres was 2.00 μm (varying from 0.85 to 3.58 μm). The rats were classified into eight groups (n = 8) and were fed with high-fat diets for two weeks to establish the hyperlipidemic condition and were then treated with CTS microspheres and WSC microspheres, CTS and WSC for four weeks. The results showed that CTS and WSC microspheres reduced blood lipids and plasma viscosity and increased the serum superoxide dismutase (SOD) levels significantly. This study is the first report of the lipid-lowering effects of CTS and WSC microspheres. CTS and WSC microspheres were found to be more effective in improving hyperlipidemia in rats than common CTS and WSC. PMID:23429200

  4. Preparation of Chitosan and Water-Soluble Chitosan Microspheres via Spray-Drying Method to Lower Blood Lipids in Rats Fed with High-Fat Diets.

    PubMed

    Tao, Yi; Zhang, Hong-Liang; Hu, Yin-Ming; Wan, Shuo; Su, Zheng-Quan

    2013-01-01

    This experiment aimed to investigate the effects of the chitosan (CTS) and water-soluble chitosan (WSC) microspheres on plasma lipids in male Sprague-Dawley rats fed with high-fat diets. CTS microspheres and WSC microspheres were prepared by the spray-drying technique. Scanning electron microscopy (SEM) micrographs showed that the microspheres were nearly spherical in shape. The mean size of CTS microspheres was 4.07 μm (varying from 1.50 to 7.21 μm) and of WSC microspheres was 2.00 μm (varying from 0.85 to 3.58 μm). The rats were classified into eight groups (n = 8) and were fed with high-fat diets for two weeks to establish the hyperlipidemic condition and were then treated with CTS microspheres and WSC microspheres, CTS and WSC for four weeks. The results showed that CTS and WSC microspheres reduced blood lipids and plasma viscosity and increased the serum superoxide dismutase (SOD) levels significantly. This study is the first report of the lipid-lowering effects of CTS and WSC microspheres. CTS and WSC microspheres were found to be more effective in improving hyperlipidemia in rats than common CTS and WSC. PMID:23429200

  5. Synthesis of water-soluble Ag₂Se QDs as a novel resonance Rayleigh scattering sensor for highly sensitive and selective ConA detection.

    PubMed

    Yan, Shuguang; Zhang, Lichun; Tang, Yurong; Lv, Yi

    2014-09-01

    Ag2Se quantum dots (QDs) have attracted a lot of interest due to their potential applications in biosensing and bioimaging. A strategy is presented that involves coupling of selenium powder reduction with the binding of silver ions, and thioglycollic acid (TGA) and glycine as stabilizers to obtain ultrasmall Ag2Se QDs at 85 °C in aqueous solution. This strategy avoids high temperatures, high pressures and organic solvents so that water-soluble 3 nm Ag2Se QDs can be directly obtained. The conjugation of ConA to TGA stabilized Ag2Se QDs by hydrogen bonds leads to the adsorption of ConA to Ag2Se QDs and forms the aggregation and leads to the generation of resonance Rayleigh scattering (RRS) as a readout signal for the sensing events. The reaction mechanism of Ag2Se QD RRS enhancement is studied in this work. The resulting RRS sensor enables the detection of ConA with limit of detection reaching 0.08 μg mL(-1) concentration in a wide linear range from 0.27 μg mL(-1) to 35 μg mL(-1). The recovery of spiked ConA in human serum samples ranges from 94% to 106%. The relative standard deviation (RSD) for eleven replicate detections is 3.6%. Our results correlate many important experimental observations and will fuel the further growth of this field. PMID:24957549

  6. Solubility of radon in selected perfluorocarbon compounds and water

    SciTech Connect

    Lewis, C.; Hopke, P.K.; Stukel, J.J.

    1987-02-01

    The solubility of radon in a series of perfluorocarbon compounds has been measured in the temperature range 5-40/sup 0/C. From the resulting data, a Hildebrand solubility parameter for radon of 8.42 +- 0.11 cal/sup 1/2/ cm/sup -3/2/ was determined. In order to provide reliable values of these parameters for radon in water, measurements were made for deionized, medium-hardness, and high-hardness water. The thermodynamic functions, ..delta..G/sup 0/, ..delta..H/sup 0/, ..delta..S/sup 0/, and ..delta..C/sub p//sup 0/, characterizing the solubilization process have also been determined.

  7. Solubility prediction of satranidazole in propylene glycol-water mixtures using extended hildebrand solubility approach.

    PubMed

    Rathi, P B

    2011-11-01

    Extended Hildebrand solubility approach is used to estimate the solubility of satranidazole in binary solvent systems. The solubility of satranidazole in various propylene glycol-water mixtures was analyzed in terms of solute-solvent interactions using a modified version of Hildebrand-Scatchard treatment for regular solutions. The solubility equation employs term interaction energy (W) to replace the geometric mean (δ(1)δ(2)), where δ(1) and δ(2) are the cohesive energy densities for the solvent and solute, respectively. The new equation provides an accurate prediction of solubility once the interaction energy, W, is obtained. In this case, the energy term is regressed against a polynomial in δ(1) of the binary mixture. A quartic expression of W in terms of solvent solubility parameter was found for predicting the solubility of satranidazole in propylene glycol-water mixtures. The expression yields an error in mole fraction solubility of ~3.74%, a value approximating that of the experimentally determined solubility. The method has potential usefulness in preformulation and formulation studies during which solubility prediction is important for drug design. PMID:23112403

  8. Development of water-soluble polyanionic carbosilane dendrimers as novel and highly potent topical anti-HIV-2 microbicides.

    PubMed

    Briz, Verónica; Sepúlveda-Crespo, Daniel; Diniz, Ana Rita; Borrego, Pedro; Rodes, Berta; de la Mata, Francisco Javier; Gómez, Rafael; Taveira, Nuno; Muñoz-Fernández, Ma Ángeles

    2015-09-21

    The development of topical microbicide formulations for vaginal delivery to prevent HIV-2 sexual transmission is urgently needed. Second- and third-generation polyanionic carbosilane dendrimers with a silicon atom core and 16 sulfonate (G2-S16), napthylsulfonate (G2-NS16) and sulphate (G3-Sh16) end-groups have shown potent and broad-spectrum anti-HIV-1 activity. However, their antiviral activity against HIV-2 and mode of action have not been probed. Cytotoxicity, anti-HIV-2, anti-sperm and antimicrobial activities of dendrimers were determined. Analysis of combined effects of triple combinations with tenofovir and raltegravir was performed by using CalcuSyn software. We also assessed the mode of antiviral action on the inhibition of HIV-2 infection through a panel of different in vitro antiviral assays: attachment, internalization in PBMCs, inactivation and cell-based fusion. Vaginal irritation and histological analysis in female BALB/c mice were evaluated. Our results suggest that G2-S16, G2-NS16 and G3-Sh16 exert anti-HIV-2 activity at an early stage of viral replication inactivating the virus, inhibiting cell-to-cell HIV-2 transmission, and blocking the binding of gp120 to CD4, and the HIV-2 entry. Triple combinations with tenofovir and raltegravir increased the anti-HIV-2 activity, consistent with synergistic interactions (CIwt: 0.33-0.66). No vaginal irritation was detected in BALB/c mice after two consecutive applications for 2 days with 3% G2-S16. Our results have clearly shown that G2-S16, G2-NS16 and G3-Sh16 have high potency against HIV-2 infection. The modes of action confirm their multifactorial and non-specific ability, suggesting that these dendrimers deserve further studies as potential candidate microbicides to prevent vaginal/rectal HIV-1/HIV-2 transmission in humans. PMID:26274532

  9. Development of water-soluble polyanionic carbosilane dendrimers as novel and highly potent topical anti-HIV-2 microbicides

    NASA Astrophysics Data System (ADS)

    Briz, Verónica; Sepúlveda-Crespo, Daniel; Diniz, Ana Rita; Borrego, Pedro; Rodes, Berta; de La Mata, Francisco Javier; Gómez, Rafael; Taveira, Nuno; Muñoz-Fernández, Mª Ángeles

    2015-08-01

    The development of topical microbicide formulations for vaginal delivery to prevent HIV-2 sexual transmission is urgently needed. Second- and third-generation polyanionic carbosilane dendrimers with a silicon atom core and 16 sulfonate (G2-S16), napthylsulfonate (G2-NS16) and sulphate (G3-Sh16) end-groups have shown potent and broad-spectrum anti-HIV-1 activity. However, their antiviral activity against HIV-2 and mode of action have not been probed. Cytotoxicity, anti-HIV-2, anti-sperm and antimicrobial activities of dendrimers were determined. Analysis of combined effects of triple combinations with tenofovir and raltegravir was performed by using CalcuSyn software. We also assessed the mode of antiviral action on the inhibition of HIV-2 infection through a panel of different in vitro antiviral assays: attachment, internalization in PBMCs, inactivation and cell-based fusion. Vaginal irritation and histological analysis in female BALB/c mice were evaluated. Our results suggest that G2-S16, G2-NS16 and G3-Sh16 exert anti-HIV-2 activity at an early stage of viral replication inactivating the virus, inhibiting cell-to-cell HIV-2 transmission, and blocking the binding of gp120 to CD4, and the HIV-2 entry. Triple combinations with tenofovir and raltegravir increased the anti-HIV-2 activity, consistent with synergistic interactions (CIwt: 0.33-0.66). No vaginal irritation was detected in BALB/c mice after two consecutive applications for 2 days with 3% G2-S16. Our results have clearly shown that G2-S16, G2-NS16 and G3-Sh16 have high potency against HIV-2 infection. The modes of action confirm their multifactorial and non-specific ability, suggesting that these dendrimers deserve further studies as potential candidate microbicides to prevent vaginal/rectal HIV-1/HIV-2 transmission in humans.

  10. Bioconjugatable Porphyrins Bearing a Compact Swallowtail Motif for Water Solubility

    PubMed Central

    Borbas, K. Eszter; Mroz, Pawel; Hamblin, Michael R.; Lindsey, Jonathan S.

    2011-01-01

    A broad range of applications requires access to water-soluble, bioconjugatable porphyrins. Branched alkyl groups attached at the branching site to the porphyrin meso position are known to impart high organic solubility. Such “swallowtail” motifs bearing a polar group (hydroxy, dihydroxyphosphoryl, dihydroxyphosphoryloxy) at the terminus of each branch have now been incorporated at a meso site in trans-AB-porphyrins. The incorporation of the swallowtail motif relies on rational synthetic methods whereby a 1,9-bis(N-propylimino)dipyrromethane (bearing a bioconjugatable tether at the 5-position) is condensed with a dipyrromethane (bearing a protected 1,5-dihydroxypent-3-yl unit at the 5-position). The two hydroxy groups in the swallowtail motif of each of the resulting zinc porphyrins can be transformed to the corresponding diphosphate or diphosphonate product. A 4-(carboxymethyloxy)phenyl group provides the bioconjugatable tether. The six such porphyrins reported here are highly water-soluble (≥20 mM at room temperature in water at pH 7) as determined by visual inspection, UV–vis absorption spectroscopy, or 1H NMR spectroscopy. Covalent attachment was carried out in aqueous solution with the unprotected porphyrin diphosphonate and a monoclonal antibody against the T-cell receptor CD3ε. The resulting conjugate performed comparably to a commercially available fluorescein isothiocyanate-labeled antibody with Jurkat cells in flow cytometry and fluorescence microscopy assays. Taken together, this work enables preparation of useful quantities of water-soluble, bioconjugatable porphyrins in a compact architecture for applications in the life sciences. PMID:16704201

  11. Identification of compounds from the water soluble extract of Cinnamomum cassia barks and their inhibitory effects against high-glucose-induced mesangial cells.

    PubMed

    Luo, Qi; Wang, Shu-Mei; Lu, Qing; Luo, Jie; Cheng, Yong-Xian

    2013-01-01

    The difficulty of diabetic nephropathy (DN) treatment makes prevention the best choice. Cinnamomum cassia barks, known as Chinese cinnamon or Chinese cassia, is one of the most popular natural spices and flavoring agents in many parts of the World. Since previous reports indicated that Chinese cinnamon extract could be used for the treatment of diabetes, we proposed that this spice may be beneficial for the prevention of DN. However, the responsible compounds need to be further identified. In this study, we isolated three new phenolic glycosides, cinnacassosides A-C (1-3), together with fifteen known compounds from the water soluble extract of Chinese cinnamon. The structures of the new compounds were identified by comprehensive spectroscopic evidence. Eleven compounds (6-9, 11, 13-18) were isolated from this spice for the first time, despite extensive research on this species in the past, which added new facets for the chemical profiling of this spice. These isolates were purposely evaluated for their inhibitory effects on IL-6 and extracellular matrix production in mesangial cells which are definitely implicated in DN. The results showed that compounds 4-8 could inhibit over secretion of IL-6, collagen IV and fibronectin against high-glucose-induced mesangial cells at 10 mM, suggesting that Chinese cinnamon could be used as a functional food against DN. PMID:24013407

  12. Compritol®888 ATO a lipid excipient for sustained release of highly water soluble active: formulation, scale-up and IVIVC study.

    PubMed

    Patere, Shilpa N; Desai, Neha S; Jain, Ankitkumar S; Kadam, Prashant P; Thatte, Urmila M; Gogtay, Nithya; Kapadia, Chhanda J; Farah, Nabil; Nagarsenker, Mangal S

    2013-10-01

    The potential of Compritol(®)888 ATO as a release modifier to retard the release of highly water soluble drug, metoprolol succinate (MPL) was exploited. Different ratios of Compritol(®)888 ATO versus MPL were utilized and the effect of various formulation methods was evaluated to sustain the release of MPL. MPL: Compritol(®)888 ATO in 1:2 ratio could successfully retard the release of MPL. Melt granulation method "as hot process" was found to be effective when compared to direct compression and wet granulation. The in vitro release characteristics of tablets were studied in pH 6.8 phosphate buffer at 50 rpm using USP Type II apparatus. Formulation F7 retarded MPL release with ~90% release after 20 h. Stability studies showed no significant difference (f2>50) in MPL release profile after three months of storage period at 25 ± 2°C/60 ± 5% RH and 40 ± 2°C/75 ± 5% RH. The bioavailability of sustained release tablets, F7 was compared with commercially available tablets, MetXL50 in 12 healthy human volunteers in a crossover design. Plasma concentration of MPL was determined using HPLC with fluorescence detector. IVIVC correlation was obtained by deconvoluting the plasma concentration-time curve using a model independent Wagner-Nelson method. Correlations of fraction of drug dissolved in vitro and fraction of drug absorbed in vivo displayed a significant linear relationship for sustained release tablets of MPL. PMID:23607649

  13. Leaching behavior of water-soluble carbohydrates from almond hulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 58% of the dry matter content of the hulls from the commercial almond (Prunus dulcis (Miller) D.A. Webb) is soluble in warm water (50-70°C) extraction. The water-soluble extractables include useful amounts of fermentable sugars (glucose, fructose, sucrose), sugar alcohols (inositol and sorbito...

  14. Which Starch Fraction is Water-Soluble, Amylose or Amylopectin?

    ERIC Educational Resources Information Center

    Green, Mark M.; And Others

    1975-01-01

    A survey of 22 popular organic chemistry textbooks showed that only four correctly stated that of the two components of starch, amylopectin is the water-soluble, and amylose is the water-insoluble. (MLH)

  15. CORM-EDE1: A Highly Water-Soluble and Nontoxic Manganese-Based photoCORM with a Biogenic Ligand Sphere.

    PubMed

    Mede, Ralf; Klein, Moritz; Claus, Ralf A; Krieck, Sven; Quickert, Stefanie; Görls, Helmar; Neugebauer, Ute; Schmitt, Michael; Gessner, Guido; Heinemann, Stefan H; Popp, Jürgen; Bauer, Michael; Westerhausen, Matthias

    2016-01-01

    [Mn(CO)5Br] reacts with cysteamine and 4-amino-thiophenyl with a ratio of 2:3 in refluxing tetrahydrofuran to the complexes of the type [{(OC)3Mn}2(μ-SCH2CH2NH3)3]Br2 (1, CORM-EDE1) and [{(OC)3Mn}2(μ-SC6H4-4-NH3)3]Br2 (2, CORM-EDE2). Compound 2 precipitates during refluxing of the tetrahydrofuran solution as a yellow solid whereas 1 forms a red oil that slowly solidifies. Recrystallization of 2 from water yields the HBr-free complex [{(OC)3Mn}2(μ-S-C6H4-4-NH2)2(μ-SC6H4-4-NH3)] (3). The n-propylthiolate ligand (which is isoelectronic to the bridging thiolate of 1) leads to the formation of the di- and tetranuclear complexes [(OC)4Mn(μ-S-nPr)2]2 and [(OC)3Mn(μ-S-nPr)]4. CORM-EDE1 possesses ideal properties to administer carbon monoxide to biological and medicinal tissues upon irradiation (photoCORM). Isolated crystalline CORM-EDE1 can be handled at ambient and aerobic conditions. This complex is nontoxic, highly soluble in water, and indefinitely stable therein in the absence of air and phosphate buffer. CORM-EDE1 is stable as frozen stock in aqueous solution without any limitations, and these stock solutions maintain their CO release properties. The reducing dithionite does not interact with CORM-EDE1, and therefore, the myoglobin assay represents a valuable tool to study the release kinetics of this photoCORM. After CO liberation, the formation of MnHPO4 in aqueous buffer solution can be verified. PMID:26672620

  16. Water and acid soluble trace metals in atmospheric particles

    NASA Technical Reports Server (NTRS)

    Lindberg, S. E.; Harriss, R. C.

    1983-01-01

    Continental aerosols are collected above a deciduous forest in eastern Tennessee and subjected to selective extractions to determine the water-soluble and acid-leachable concentrations of Cd, Mn, Pb, and Zn. The combined contributions of these metals to the total aerosol mass is 0.5 percent, with approximately 70 percent of this attributable to Pb alone. A substantial fraction (approximately 50 percent or more) of the acid-leachable metals is soluble in distilled water. In general, this water-soluble fraction increases with decreasing particle size and with increasing frequency of atmospheric water vapor saturation during the sampling period. The pattern of relative solubilities (Zn being greater than Mn, which is approximately equal to Cd, which is greater than Pb) is found to be similar to the general order of the thermodynamic solubilities of the most probable salts of these elements in continental aerosols with mixed fossil fuel and soil sources.

  17. Adhesive evaluation of water-soluble LARC-TPI

    NASA Technical Reports Server (NTRS)

    Progar, Donald J.; Pike, Roscoe A.

    1987-01-01

    The water-soluble polyimide, identified as TPI(MTC)/H2O, was evaluated as a high temperature thermoplastic adhesive for bonding Ti-6Al-4V and comparing those results primarily with results reported in earlier work with the polyamic-acid/diglyme material. The lap shear strength test was the primary test performed to evaluate the adhesive before (controls) and after thermal exposure in air at 204 C for up to 5000 hours and after a 72 hour water-boil exposure. Lap shear strengths were determined at RT, 177, 204, and 232 C. The adhesive was also characterized after fracture by determining the glass transition temperature as well as defining the mode of failure by visual observation. In general, the results indicate that the TPI(MTC)/H2O retains high lap shear strengths after thermal exposure but had reduced strengths after the water-boil exposure. All failures were cohesive. The TPI(MTC)/H2O compared very well with previous data reported for the standard polyamic-acid/diglyme LARC-TPI results, and therefore, shows promise as a water-soluble adhesive for use in various applications.

  18. New water-soluble carbamate ester derivatives of resveratrol.

    PubMed

    Mattarei, Andrea; Carraro, Massimo; Azzolini, Michele; Paradisi, Cristina; Zoratti, Mario; Biasutto, Lucia

    2014-01-01

    Low bioavailability severely hinders exploitation of the biomedical potential of resveratrol. Extensive phase-II metabolism and poor water solubility contribute to lowering the concentrations of resveratrol in the bloodstream after oral administration. Prodrugs may provide a solution-protection of the phenolic functions hinders conjugative metabolism and can be exploited to modulate the physicochemical properties of the compound. We report here the synthesis and characterization of carbamate ester derivatives of resveratrol bearing on each nitrogen atom a methyl group and either a methoxy-poly(ethylene glycol)-350 (mPEG-350) or a butyl-glucosyl promoiety conferring high water solubility. Ex vivo absorption studies revealed that the butyl-glucosyl conjugate, unlike the mPEG-350 one, is able to permeate the intestinal wall. In vivo pharmacokinetics confirmed absorption after oral administration and showed that no hydrolysis of the carbamate groups takes place. Thus, sugar groups can be attached to resveratrol to obtain soluble derivatives maintaining to some degree the ability to permeate biomembranes, perhaps by facilitated or active transport. PMID:25275336

  19. Total and water-soluble phosphorus in broiler litter over three flocks with alum litter treatment and dietary inclusion of high available phosphorus corn and phytase supplementation.

    PubMed

    Miles, D M; Moore, P A; Smith, D R; Rice, D W; Stilborn, H L; Rowe, D R; Lott, B D; Branton, S L; Simmons, J D

    2003-10-01

    Three pen trials were conducted to determine the main effect of alum addition to litter on form of poultry litter P using a 2 x 2 factorial structure of the subunit treatments: diets including high available phosphorus/low phytate corn (HAPC) and phytase (PHYT). Male broilers (1,760 per flock) were grown to 42 d having starter diets with 0.45% available P and grower diets with 0.35% available P. In the first trial, total litter P (tP) was greatest for the yellow dent corn (YDC) diet (12 g/kg) and least for the HAPC and PHYT combination (H&P) diet (6.9 g/kg) with the individual PHYT and HAPC diets falling in between at 9.1 g/kg and 9.4 g/kg tP. Also in the first trial, the litter water-soluble P (wP) was highest for PHYT (2.8 g/kg), least for the HAPC and H&P diets (1.5 g/kg) with the YDC diet falling between (2.2 g/kg). Alum was added to the litter after the first experiment. In the second and third experiments, alum inclusion significantly reduced the wP when compared with the treatments with no alum. In the third trial, the least wP was present in the alum-HAPC treatment. Phytase, YDC, and HAPC diets with no alum litter treatment generated the most wP. Since these diets appear to have little or no difference with respect to quantity of wP, this work suggests that form of litter P generated by alternative diets should be considered as criteria when attempting to reduce P in broiler litter applied to land. PMID:14601730

  20. The effect of dietary water soluble carbohydrate to nitrogen ratio on nitrogen partitioning and isotopic fractionation of lactating goats offered a high-nitrogen diet.

    PubMed

    Cheng, L; Edwards, G R; Dewhurst, R J; Nicol, A M; Pacheco, D

    2016-05-01

    The objective of this study was to investigate the relationship between nitrogen (N) partitioning and isotopic fractionation in lactating goats consuming diets with a constant high concentration of N and increasing levels of water soluble carbohydrate (WSC). Eight lactating goats were offered four different ratios of WSC : N in the diet. A two-period incomplete cross-over design was used, with two goats assigned to each treatment in each period. N balance measurements were conducted, with measurement of feed N intake and total output of N in milk, faeces and urine. Treatment, period and infusion effects were tested using general ANOVA; the relationships between variables were analysed by linear regression. Dietary treatment and period had significant effects on dry matter (DM) intake (g/day). DM digestibility (g/kg DM) and N digestibility (g/kg N) increased as the ratio of WSC : N increased in the diet. No treatment effect was observed on milk urea N concentration (g/l) or urinary excretion of purine derivatives (mM/day). Although dietary treatment and period had significant effects on N intake, the change of N intake was small; no effect was observed for N partitioning among faeces, milk and urine. Milk, plasma and faeces were enriched in 15N compared with feed, whilst urine was depleted in 15N relative to feed. No significant relationship was established between N partitioning and isotopic fractionation. This study failed to confirm the potential to use N isotopic fractionation as an indicator of N partitioning in dairy goats when diets provided N in excess to requirements, most likely because the range of milk N output/N intake and urinary N output/N intake were narrow. PMID:26556633

  1. Separation of water-soluble vitamins by reversed-phase high performance liquid chromatography with ultra-violet detection: application to polyvitaminated premixes.

    PubMed

    Heudi, Olivier; Kilinç, Tamara; Fontannaz, Patric

    2005-04-01

    Nine water-soluble vitamins: [thiamine (B1), ascorbic acid (C), nicotinamide (PP), pyridoxine (B6), calcium pantothenate (B5), folic acid (B9), cyanocobalamin (B12), riboflavin (B2) and biotin (B8)] were separated on a YMC-Pack Pro C18 column (250 mm x 4.6 mm, 5 microm particle size) in a single run with a gradient elution of mobile phase consisting of 0.025% trifluoroacetic acid pH 2.6 (solvent A) and acetonitrile (solvent B). The separation was achieved within 17 min with a flow rate of 0.8 ml min(-1) and the detection was performed at two wavelengths (210 and 275 nm). The calibration graphs plotted with six concentrations of each vitamin were linear with a regression coefficient R2 > 0.995. The method was applied for the quantification of vitamins B1, C, PP, B6, B5, B9 B2 and B8 in polyvitaminated premixes (premixes) used for the fortification of infant nutrition products. The sample preparation involves an aqueous extraction of vitamins and two different samples dilution were used prior the LC-analysis. The specificity of the method was demonstrated by the retention characteristics, UV spectra and by comparing the peak purity with the standard of each vitamin. The repeatability of the method was evaluated at different level of concentrations on 12 premixes and the coefficients of variation (CVr) were below 6.5%. The values of the intermediate precision (CV1) were below 9.6% (n = 6). The concentrations of vitamins found in premixes with our method were comparable to the declared values, since no bias was found between the two sets of results at 95% confidence. The simplicity of the procedure should make it highly desirable for quality control of premixes in the food industry. PMID:15861787

  2. A novel method for high-pressure annealing experiments in a water-rich environment: hydrogen solubility and speciation in natural, gem-quality diopside

    NASA Astrophysics Data System (ADS)

    Bromiley, G. D.; Keppler, H.; Bromiley, F. A.; Jacobsen, S. D.

    2003-04-01

    from 0.5 to 4.0 GPa, 1000 to 1100^oC, with run times of several hundred hours. The effects of increasing pressure and oxygen fugacity on hydeogen solubility, and hydrogen speciation in the diopside have been fully characterised using polarised FTIR spectoscopy. The high-quality of recovered samples means that further investigations on the effects of increasing water contents on other physical properties in the samples should be possible.

  3. Improvement in solubility of poor water-soluble drugs by solid dispersion

    PubMed Central

    Sareen, Swati; Mathew, George; Joseph, Lincy

    2012-01-01

    This article is intended to combine recent literature on solid dispersion technology for solubility enhancement with special emphasis on mechanism responsible for the same by solid dispersion, various preparation methods, and evaluation parameters. Solubility behavior is the most challenging aspect for various new chemical entities as 60% of the new potential products possess solubility problems. This is the biggest reason for new drug molecules not reaching to the market or not reaches to full potential. There are various techniques to enhance the drug solubility such as particle size reduction, nanosuspension, use of surfactants, salt formation, solid dispersion, etc. From this article it may be concluded that solid dispersion is an important approach for improvement of bioavailability of poor water-soluble drugs. PMID:23071955

  4. New water soluble pyrroloquinoline derivatives as new potential anticancer agents.

    PubMed

    Ferlin, Maria Grazia; Marzano, Christine; Dalla Via, Lisa; Chilin, Adriana; Zagotto, Giuseppe; Guiotto, Adriano; Moro, Stefano

    2005-08-01

    A new class of water soluble 3H-pyrrolo[3,2-f]quinoline derivatives has been synthesized and investigated as potential anticancer drugs. Water solubility profiles have been used to select the most promising derivatives. The novel compound 10, having two (2-diethylamino-ethyl) side chains linked through positions 3N and 9O, presents a suitable water solubility profile, and it was shown to exhibit cell growth inhibitory properties when tested against the in-house panel of cell lines, in particular those obtained from melanoma. PMID:15936202

  5. The removal of kaolinite suspensions by acid-soluble and water-soluble chitosans.

    PubMed

    Chung, Ying-Chien; Wu, Li-Chun; Chen, Chih-Yu

    2013-01-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This research compared the coagulant performance of acid-soluble chitosan with water-soluble chitosan and with coagulant mixtures of chitosan and aluminium sulfate (alum). We also assessed the coagulant performance of chitosan and poly-aluminium chloride (PAC) to remove kaolinite from turbid water. In addition, we evaluated their respective coagulation efficiencies under different coagulant concentrations, degrees of turbidity (NTU) and pH levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants in order to illustrate major factors affecting kaolinite coagulation. The optimal concentrations of acid- versus water- soluble chitosan required to remove kaolinite from a 300 NTU suspension were 4.0 and 10.0 mg/l, respectively-with individual efficiencies of 79.3 and 92.4%, in that order. Optimum concentrations ofwater-soluble chitosan demonstrated a broader range than that of acid-soluble chitosan. In addition, it is of note that chitosan/alum and chitosan/PAC water-soluble coagulant mixtures demonstrated much wider ranges of optimal concentrations for turbidity reduction than either alum or PAC alone. Moreover, our water-soluble chitosan coagulant mixtures produced denser floc with elevated settling velocities that favour cost savings relevant to both installation and operational expenses. Based on our observations of these noteworthy performances, we confidently propose that a coagulant mixture with a 1:1 mass ratio of chitosan and alum presents a remarkably more cost-effective alternative to the use of chitosan alone in water treatment systems. PMID:23530342

  6. Soluble arsenic removal at water treatment plants

    SciTech Connect

    McNeill, L.S.; Edwards, M.

    1995-04-01

    Arsenic profiles were obtained from full-scale conventional treatment (coagulation, Fe-Mn oxidation, or softening) plants, facilitating testing of theories regarding arsenic removal. Soluble As(V) removal efficiency was controlled primarily by pH during coagulation, be Fe{sup +2} oxidation and Fe(OH){sub 3} precipitation during Fe-Mn oxidation, and by Mg(OH){sub 2} formation during softening. Insignificant soluble As(V) removal occurred during calcite precipitation at softening plants or during Mn{sup +2} oxidation-precipitation at Fe-Mn oxidation plants. The extent of soluble As(V) removal during coagulation and softening treatments was lower than expected. Somewhat surprisingly, during coagulation As(V) removal efficiencies were limited by particulate aluminum formation and removal, because much of the added coagulant was not removed by 0.45-{mu}m-pore-size filters. At one utility, reducing the coagulation pH from 7.4 to 6.8 (at constant alum dose) improved removal of particulate aluminum, thereby enhancing soluble As(V) removal during treatment.

  7. Comparative study on the different techniques for the preparation of sustained-release hydrophobic matrices of a highly water-soluble drug.

    PubMed

    Abd El-Halim, S M; Amin, M M; El-Gazayerly, O N; Abd El-Gawad, N A

    2010-12-01

    The objective of the present study was to control the release of freely water-soluble salbutamol sulphate (SS) over a prolonged period of time by embedding the drug into slowly eroding waxy matrix materials such as Precirol® ATO5, Compritol® 888 ATO, beeswax, paraffin wax, carnauba wax, and stearyl alcohol. The matrices were prepared by either direct compression or hot fusion techniques. The compatibility of the drug with the various excipients was examined using differential scanning calorimetry (DSC). A factorial design was employed to study the effect of polymer type, polymer concentration (15% and 35%), and filler type (Avicel® PH101 and dibasic calcium phosphate dehydrate (DCP) on the in vitro drug release at 6 h. Results of DSC confirmed drugexcipient compatibility. Increasing the polymer ratio resulted in a significant retardation of drug release. The use of DCP resulted in significant retardation and incomplete drug release while the use of Avicel did not. The hot fusion method was found to be more effective than the direct compression method in retarding SS release. A Precirol formulation, prepared using the hot fusion technique, had the slowest drug release, releasing about 31.3% of SS over 6 h. In contrast, Compritol, prepared using the direct compression technique, had the greatest retardation, providing sustained release of 59.3% within 6 h. A hydrophobic matrix system is thus a useful technique for prolonging the release of freely water-soluble drugs such as salbutamol sulphate. PMID:22491314

  8. The Exochelins of Pathogenic Mycobacteria: Unique, Highly Potent, Lipid- and Water-Soluble Hexadentate Iron Chelators with Multiple Potential Therapeutic Uses

    PubMed Central

    Horwitz, Lawrence D.

    2014-01-01

    Abstract Significance: Exochelins are lipid- and water-soluble siderophores of Mycobacterium tuberculosis with unique properties that endow them with exceptional pharmacologic utility. Exochelins can be utilized as probes to decipher the role of iron in normal and pathological states, and, since they rapidly cross cell membranes and chelate intracellular iron with little or no toxicity, exochelins are potentially useful for the treatment of a number of iron-dependent pathological phenomena. Recent Advances: In animal models, exochelins have been demonstrated to have promise for the treatment of transfusion-related iron overload, restenosis after coronary artery angioplasty, cancer, and oxidative injury associated with acute myocardial infarction and transplantation. Critical Issues: To be clinically effective, iron chelators should be able to rapidly enter cells and chelate iron at key intracellular sites. Desferri-exochelins, and other lipid-soluble chelators, can readily cross cell membranes and remove intracellular free iron; whereas deferoxamine, which is lipid insoluble, cannot do so. Clinical utility also requires that the chelators be nontoxic, which, we hypothesize, includes the capability to prevent iron from catalyzing free radical reactions which produce •OH or other reactive oxygen species. Lipid-soluble iron chelators currently available for clinical application are bidentate (deferiprone) or tridentate (desferasirox) molecules that do not block all six sites on the iron molecule capable of catalyzing free radical reactions. In contrast, desferri-exochelins are hexadentate molecules, and by forming a one-to-one binding relationship with iron, they prevent free radical reactions. Future Directions: Clinical studies are needed to assess the utility of desferri-exochelins in the treatment of iron-dependent pathological disorders. Antioxid. Redox Signal. 21, 2246–2261. PMID:24684595

  9. Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate

    PubMed Central

    Yousaf, Abid Mehmood; Mustapha, Omer; Kim, Dong Wuk; Kim, Dong Shik; Kim, Kyeong Soo; Jin, Sung Giu; Yong, Chul Soon; Youn, Yu Seok; Oh, Yu-Kyoung; Kim, Jong Oh; Choi, Han-Gon

    2016-01-01

    Purpose The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate. Methods Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP) and Labrafil® M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion. Results All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1:4:0.5 resulted in a particle size of <200 nm with the drug present in the amorphous state. It demonstrated the highest solubility (32.51±2.41 μg/mL), an excellent dissolution (~85% in 10 minutes), and an oral bioavailability ~2.5-fold better than that of the free drug. It showed similar oral bioavailability compared to the conventional solid dispersion. Conclusion Electrosprayed nanospherules, which provide improved solubility and bioavailability, are promising drug delivery tools for oral administration of poorly water-soluble fenofibrate. PMID:26834471

  10. Water solubility in rhyolitic silicate melts at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Ryan, Amy; Russell, Kelly; Nichols, Alexander; Porritt, Lucy; Friedlander, Elizabeth

    2014-05-01

    High temperature (900-1100 °C) experiments have been conducted to measure the solubility of water in a rhyolitic melt at atmospheric pressure (1 atm) and to quantify the magnitude of retrograde solubility at low pressure. Individual cores (1 cm x 1 cm) of crystal- and bubble-free rhyolitic obsidian from Hrafntinnugryggur, Krafla (Iceland) were held in a furnace at 900-1100 °C for 0.25 to 20 hours. During this time, the uniform bubble-free cores vesiculate to produce variably swollen bubble-rich run products. The volume change in each core reflects the volume of bubbles produced in each experiment and depends on the experimental temperature and the time held at that temperature. The run product volumes for isothermal experiments (e.g., 950 °C) increase non-linearly with increasing time (e.g., 0.18 cm3 at 1.5 h, 0.96 cm3 at 12.5 h) until reaching a maximum value, after which the volume does not change appreciably. We take this plateau in the isothermal volume:time curve as coinciding with the 1 atm. solubility limit for the rhyolite at this temperature. With increasing temperature, the slope and final horizontal plateaus of the volume:time curves increase such that samples from the higher temperature suites vesiculate more, as well as more rapidly (e.g., 0.85 cm3 after 0.5 hours, 1.78 cm3 after 1 hour at 1100 °C). The variations in the maximum volume of bubbles produced for each temperature constrain the retrograde solubility of water in the melt at 1 atm. Fourier transform infrared spectroscopy (FTIR) analyses of the residual water content of the glass in the starting material and in the most vesiculated sample from each temperature suite shows a decrease in the water content of the glass from an initial 0.114 wt% (σ 0.013) to 0.098 wt% (σ 0.010), 0.087 wt% (σ 0.009), 0.093 wt% (σ 0.008), 0.090 wt% (σ 0.006) and 0.108 wt% (σ 0.010) for 900 °C, 950 °C, 1000 °C, 1050 °C and 1100 °C respectively. This change in the solubility of water at different

  11. Simultaneous determination of some water-soluble vitamins and preservatives in multivitamin syrup by validated stability-indicating high-performance liquid chromatography method.

    PubMed

    Vidović, Stojanka; Stojanović, Biljana; Veljković, Jelena; Prazić-Arsić, Ljiljana; Roglić, Goran; Manojlović, Dragan

    2008-08-22

    HPLC stability-indicating method has been developed for the simultaneous determination of some water-soluble vitamins (ascorbic acid, thiamine hydrochloride, riboflavin-5'-phosphate sodium, pyridoxine hydrochloride, nicotinamide, D(+)-panthenol) and two preservatives (methylparaben and sodium benzoate) in multivitamin syrup preparation. Water-soluble vitamins, preservatives and their degradants were separated on Zorbax SB-Aq (C(18)) (250 mm x 4.6 mm, 5 microm) column at an ambient temperature. Combined isocratic and gradient elution was performed with a mobile phase consisting of 0.0125 M hexane-1-sulfonic acid sodium salt in 0.1% (m/v) o-phosphoric acid, pH 2.4-2.5 (solvent A) and acetonitrile (solvent B) at the flow-rate 1 ml min(-1). Starting with solvent A an isocratic elution was performed for 15 min, then the composition was changed to 85% of A and 15% of B during the next 20 min and it was constant for 5 min, then the composition was changed to 70% of A and 30% of B during next 15 min and it was constant for 5 min and finally was changed to 100% of A as at the beginning of the elution. Detection was performed with diode array detector at 210, 230 and 254 nm. Multivitamin syrup preparation was subjected to stress testing (forced degradation) in order to demonstrate that degradants from the vitamins, preservatives and/or product excipients do not interfere with the quantification of vitamins and preservatives. Typical validation characteristics: selectivity, accuracy, precision, linearity, range, limit of quantification and limit of detection were evaluated for vitamins and preservatives. PMID:18644604

  12. Selective Water-Soluble Gelatinase Inhibitor Prodrugs

    PubMed Central

    Gooyit, Major; Lee, Mijoon; Schroeder, Valerie A.; Ikejiri, Masahiro; Suckow, Mark A.; Mobashery, Shahriar; Chang, Mayland

    2011-01-01

    SB-3CT (1), a selective and potent thiirane-based gelatinase inhibitor, is effective in animal models of cancer metastasis and stroke; however, it is limited by poor aqueous solubility and extensive metabolism. We addressed these issues by blocking the primary site of metabolism and capitalizing on a prodrug strategy to achieve >5000-fold increased solubility. The amide prodrugs were quantitatively hydrolyzed in human blood to a potent gelatinase inhibitor, ND-322 (3). The arginyl amide prodrug (ND-478, 5d) was metabolically stable in mouse, rat, and human liver microsomes. Both 5d and 3 were non-mutagenic in the Ames II mutagenicity assay. The prodrug 5d showed moderate clearance of 0.0582 L/min/kg, remained mostly in the extracellular fluid compartment (Vd = 0.0978 L/kg), and had a terminal half-life of >4 h. The prodrug 5d had superior pharmacokinetic properties than 3, making the thiirane class of selective gelatinase inhibitors suitable for intravenous administration in treatment of acute gelatinase-dependent diseases. PMID:21866961

  13. Water soluble cations and the fluvial history of Mars

    NASA Technical Reports Server (NTRS)

    Silverman, M. P.; Munoz, E. F.

    1975-01-01

    The electrical conductivity and water soluble Na, K, Ca, and Mg of aqueous solutions of terrestrial soils and finely divided igneous and metamorphic rocks were determined. Soils from dry terrestrial basins with a history of water accumulation as well as soils from the topographic lows of valleys accumulated water soluble cations, particularly Na and Ca. These soils as a group can be distinguished from the rocks or a second group of soils (leached upland soils and soils from sites other than the topographic lows of valleys) by significant differences in their mean electrical conductivity and water-soluble Na + Ca content. Similar measurements on multiple samples from the surface of Mars, collected by an automated long-range roving vehicle along a highlands-to-basin transect at sites with morphological features resembling dry riverlike channels, are suggested to determine the fluvial history of the planet.

  14. Copper(II) complexes with highly water-soluble L- and D-proline-thiosemicarbazone conjugates as potential inhibitors of Topoisomerase IIα.

    PubMed

    Bacher, Felix; Enyedy, Éva A; Nagy, Nóra V; Rockenbauer, Antal; Bognár, Gabriella M; Trondl, Robert; Novak, Maria S; Klapproth, Erik; Kiss, Tamás; Arion, Vladimir B

    2013-08-01

    Two proline-thiosemicarbazone bioconjugates with excellent aqueous solubility, namely, 3-methyl-(S)-pyrrolidine-2-carboxylate-2-formylpyridine thiosemicarbazone [L-Pro-FTSC or (S)-H2L] and 3-methyl-(R)-pyrrolidine-2-carboxylate-2-formylpyridine thiosemicarbazone [D-Pro-FTSC or (R)-H2L], have been synthesized and characterized by elemental analysis, one- and two-dimensional (1)H and (13)C NMR spectroscopy, and electrospray ionization mass spectrometry. The complexation behavior of L-Pro-FTSC with copper(II) in an aqueous solution and in a 30% (w/w) dimethyl sulfoxide/water mixture has been studied via pH potentiometry, UV-vis spectrophotometry, electron paramagnetic resonance, (1)H NMR spectroscopy, and spectrofluorimetry. By the reaction of copper(II) acetate with (S)-H2L and (R)-H2L in water, the complexes [Cu(S,R)-L] and [Cu(R,S)-L] have been synthesized and comprehensively characterized. An X-ray diffraction study of [Cu(S,R)-L] showed the formation of a square-pyramidal complex, with the bioconjugate acting as a pentadentate ligand. Both copper(II) complexes displayed antiproliferative activity in CH1 ovarian carcinoma cells and inhibited Topoisomerase IIα activity in a DNA plasmid relaxation assay. PMID:23829568

  15. Novel Water-Soluble Mucoadhesive Carbosilane Dendrimers for Ocular Administration.

    PubMed

    Bravo-Osuna, I; Vicario-de-la-Torre, M; Andrés-Guerrero, V; Sánchez-Nieves, J; Guzmán-Navarro, M; de la Mata, F J; Gómez, R; de Las Heras, B; Argüeso, P; Ponchel, G; Herrero-Vanrell, R; Molina-Martínez, I T

    2016-09-01

    The purpose of this research was to determine the potential use of water-soluble anionic and cationic carbosilane dendrimers (generations 1-3) as mucoadhesive polymers in eyedrop formulations. Cationic carbosilane dendrimers decorated with ammonium -NH3(+) groups were prepared by hydrosylilation of Boc-protected allylamine and followed by deprotection with HCl. Anionic carbosilane dendrimers with terminal carboxylate groups were also employed in this study. In vitro and in vivo tolerance studies were performed in human ocular epithelial cell lines and rabbit eyes respectively. The interaction of dendrimers with transmembrane ocular mucins was evaluated with a surface biosensor. As proof of concept, the hypotensive effect of a carbosilane dendrimer eyedrop formulation containing acetazolamide (ACZ), a poorly water-soluble drug with limited ocular penetration, was tested after instillation in normotensive rabbits. The methodology used to synthesize cationic dendrimers avoids the difficulty of obtaining neutral -NH2 dendrimers that require harsher reaction conditions and also present high aggregation tendency. Tolerance studies demonstrated that both prototypes of water-soluble anionic and cationic carbosilane dendrimers were well tolerated in a range of concentrations between 5 and 10 μM. Permanent interactions between cationic carbosilane dendrimers and ocular mucins were observed using biosensor assays, predominantly for the generation-three (G3) dendrimer. An eyedrop formulation containing G3 cationic carbosilane dendrimers (5 μM) and ACZ (0.07%) (289.4 mOsm; 5.6 pH; 41.7 mN/m) induced a rapid (onset time 1 h) and extended (up to 7 h) hypotensive effect, and led to a significant increment in the efficacy determined by AUC0(8h) and maximal intraocular pressure reduction. This work takes advantage of the high-affinity interaction between cationic carbosilane dendrimers and ocular transmembrane mucins, as well as the tensioactive behavior observed for these

  16. Transformation of acidic poorly water soluble drugs into ionic liquids.

    PubMed

    Balk, Anja; Wiest, Johannes; Widmer, Toni; Galli, Bruno; Holzgrabe, Ulrike; Meinel, Lorenz

    2015-08-01

    Poor water solubility of active pharmaceutical ingredients (API) is a major challenge in drug development impairing bioavailability and therapeutic benefit. This study is addressing the possibility to tailor pharmaceutical and physical properties of APIs by transforming these into tetrabutylphosphonium (TBP) salts, including the generation of ionic liquids (IL). Therefore, poorly water soluble acidic APIs (Diclofenac, Ibuprofen, Ketoprofen, Naproxen, Sulfadiazine, Sulfamethoxazole, and Tolbutamide) were converted into TBP ILs or low melting salts and compared to the corresponding sodium salts. Free acids and TBP salts were characterized by NMR and IR spectroscopy, DSC and XRPD, DVS and dissolution rate measurements, release profiles, and saturation concentration measurements. TBP salts had lower melting points and glass transition temperatures and dissolution rates were improved up to a factor of 1000 as compared to the corresponding free acid. An increase in dissolution rates was at the expense of increased hygroscopicity. In conclusion, the creation of TBP ionic liquids or solid salts from APIs is a valuable concept addressing dissolution and solubility challenges of poorly water soluble acidic compounds. The data suggested that tailor-made counterions may substantially expand the formulation scientist's armamentarium to meet challenges of poorly water soluble drugs. PMID:25976317

  17. 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.

  18. Antioxidant Properties of Water-Soluble Gum from Flaxseed Hulls.

    PubMed

    Bouaziz, Fatma; Koubaa, Mohamed; Barba, Francisco J; Roohinejad, Shahin; Chaabouni, Semia Ellouz

    2016-01-01

    Soluble flaxseed gum (SFG) was extracted from flax (Linum usitatissimum) hulls using hot water, and its functional groups and antioxidant properties were investigated using infrared spectroscopy and different antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), reducing power capacity, and β-carotene bleaching inhibition assay), respectively. The antioxidant capacity of SFG showed interesting DPPH radical-scavenging capacity (IC50 SFG = 2.5 mg·mL(-1)), strong ABTS radical scavenging activity (% inhibition ABTS = 75.6% ± 2.6% at 40 mg·mL(-1)), high reducing power capacity (RPSFG = 5 mg·mL(-1)), and potent β-carotene bleaching inhibition activity (IC50 SFG = 10 mg·mL(-1)). All of the obtained results demonstrate the promising potential use of SFG in numerous industrial applications, and a way to valorize flaxseed hulls. PMID:27490574

  19. Transfer molding of nanoscale oxides using water-soluble templates.

    PubMed

    Bass, John D; Schaper, Charles D; Rettner, Charles T; Arellano, Noel; Alharbi, Fahhad H; Miller, Robert D; Kim, Ho-Cheol

    2011-05-24

    We report a facile method for creating nanoscopic oxide structures over large areas that is capable of producing high aspect ratio nanoscale structures with feature sizes below 50 nm. A variety of nanostructured oxides including TiO(2), SnO(2) and organosilicates are formed using sol-gel and nanoparticle precursors by way of molding with water-soluble polymeric templates generated from silicon masters. Sequential stacking techniques are developed that generate unique 3-dimensional nanostructures with combinatorially mixed geometries, scales, and materials. Applicable to a variety of substrates, this scalable method allows access to a broad range of new thin film morphologies for applications in devices, catalysts, and functional surface coatings. PMID:21469708

  20. Improved water-soluble polymers for enhanced recovery of oil

    SciTech Connect

    Martin, F.D.; Hatch, M.J.; Shepitka, J.S.; Ward, J.S.

    1983-01-01

    Two principal types of polymers have been used extensively for enhanced recovery of crude oil: partially hydrolyzed polyacrylamide (HPAM) and xanthan gum. Because of its lower cost, HPAM is being used in a majority of the field projects when water-soluble polymers are applied. However, HPAM does lose viscosity in brines, particularly when divalent ions are present, and is susceptible to mechanical degradation under high shear conditions. Although many different polymer structures were evaluated in the laboratory tests, the main focus consisted of modifying the structure of HPAM and observing the effects on brine and shear stability. Testing of these analogs provided a systematic correlation of polymer structure with polymer performance so that improved compounds could be developed. 33 references.

  1. Solubility of carbon dioxide in methyldiethanolamine + methanol + water

    SciTech Connect

    Henni, A.; Mather, A.E.

    1995-03-01

    Aqueous solutions of methyldiethanolamine (MDEA) are attractive solvents for the selective removal of H{sub 2}S from process stream containing CO{sub 2} and hydrocarbons. The solubility of CO{sub 2} in a mixed nonaqueous solvent of methyldiethanolamine MDEA and methanol has been measured at 40 C. The results are compared with the solubility of CO{sub 2} in pure methanol. The solubility of CO{sub 2} has also been obtained at 40 and 100 C in an aqueous mixed solvent consisting of methanol (40 mass %), MDEA (40 mass %), and water (20 mass %) at partial pressures of the acid gas up to 7.04 MPa. The solubility results are compared with the nonaqueous mixed solvent results and previously reported data for aqueous methyldiethanolamine.

  2. Characteristics of size-fractionated atmospheric metals and water-soluble metals in two typical episodes in Beijing

    NASA Astrophysics Data System (ADS)

    Wang, Qingqing; Ma, Yongliang; Tan, Jihua; Zheng, Naijia; Duan, Jingchun; Sun, Yele; He, Kebin; Zhang, Yuanxun

    2015-10-01

    The abundance and behaviour of metals and water-soluble metals (V, Cr, Mn, Fe, Cu, Zn, As, Sr, Ag, Cd, Sn, Sb, Ba and Pb) in size-fractionated aerosols were investigated during two typical episodes in Beijing. Water-soluble inorganic ions (Na+, K+, Mg2+, Ca2+, NH4+ , F-, Cl-, SO42- and NO3-) were also measured. Atmospheric metals and water-soluble metals were both found at high levels; for PM2.5, average As, Cr, Cd, Cu, Mn and Pb concentrations were 14.8, 203.3, 2.5, 18.5, 42.6 and 135.3 ng/m3, respectively, and their water-soluble components were 11.1, 1.7, 2.4, 14.5, 19.8 and 97.8 ng/m3, respectively. Daily concentrations of atmospheric metals and water-soluble metals were generally in accordance with particle mass. The highest concentrations of metals and water-soluble metals were generally located in coarse mode and droplet mode, respectively. The lowest mass of metals and water-soluble metals was mostly in Aitken mode. The water solubility of all metals was low in Aitken and coarse modes, indicating that freshly emitted metals have low solubility. Metal water solubility generally increased with the decrease in particle size in the range of 0.26-10 μm. The water solubility of metals for PM10 was: 50% ≤ Cd, As, Sb, Pb; 26% < V, Mn, Cu, Zn and Sr ≤ 50%; others ≤20%. Most metals, water-soluble metals and their water solubility increased when polluted air mass came from the near west, near north-west, south-west and south-east of the mainland, and decreased when clean air mass came from the far north-west and far due south. The influence of dust-storms and clean days on water-soluble metals and size distribution was significant; however, the influence of rainfall was negligible. Aerosols with high concentrations of SO42- , K+ and NH4+ might indicate increased potential for human health effects because of their high correlation with water-soluble metals. Industrial emissions contribute substantially to water-soluble metal pollution as water-soluble metals

  3. Characteristics of size-fractionated atmospheric metals and water-soluble metals in two typical episodes in Beijing

    NASA Astrophysics Data System (ADS)

    Wang, Qingqing; Ma, Yongliang; Tan, Jihua; Zheng, Naijia; Duan, Jingchun; Sun, Yele; He, Kebin; Zhang, Yuanxun

    2015-10-01

    The abundance and behaviour of metals and water-soluble metals (V, Cr, Mn, Fe, Cu, Zn, As, Sr, Ag, Cd, Sn, Sb, Ba and Pb) in size-fractionated aerosols were investigated during two typical episodes in Beijing. Water-soluble inorganic ions (Na+, K+, Mg2+, Ca2+, NH4+ , F-, Cl-, SO4 2 - and NO3-) were also measured. Atmospheric metals and water-soluble metals were both found at high levels; for PM2.5, average As, Cr, Cd, Cu, Mn and Pb concentrations were 14.8, 203.3, 2.5, 18.5, 42.6 and 135.3 ng/m3, respectively, and their water-soluble components were 11.1, 1.7, 2.4, 14.5, 19.8 and 97.8 ng/m3, respectively. Daily concentrations of atmospheric metals and water-soluble metals were generally in accordance with particle mass. The highest concentrations of metals and water-soluble metals were generally located in coarse mode and droplet mode, respectively. The lowest mass of metals and water-soluble metals was mostly in Aitken mode. The water solubility of all metals was low in Aitken and coarse modes, indicating that freshly emitted metals have low solubility. Metal water solubility generally increased with the decrease in particle size in the range of 0.26-10 μm. The water solubility of metals for PM10 was: 50% ≤ Cd, As, Sb, Pb; 26% < V, Mn, Cu, Zn and Sr ≤ 50%; others ≤20%. Most metals, water-soluble metals and their water solubility increased when polluted air mass came from the near west, near north-west, south-west and south-east of the mainland, and decreased when clean air mass came from the far north-west and far due south. The influence of dust-storms and clean days on water-soluble metals and size distribution was significant; however, the influence of rainfall was negligible. Aerosols with high concentrations of SO4 2 - , K+ and NH4+ might indicate increased potential for human health effects because of their high correlation with water-soluble metals. Industrial emissions contribute substantially to water-soluble metal pollution as water-soluble metals

  4. Solubility of Carbon Dioxide in Water.

    ERIC Educational Resources Information Center

    Bush, Pat; And Others

    1992-01-01

    Describes an activity measuring the amount of dissolved carbon dioxide in carbonated water at different temperatures. The amount of carbon dioxide is measured by the amount of dilute ammonia solution needed to produce a pH indicator color change. (PR)

  5. Preparation of microspheres of water-soluble pharmaceuticals.

    PubMed

    Huang, H P; Ghebre-Sellassie, I

    1989-01-01

    An emulsion-solvent evaporation procedure involving the dispersion of an alcoholic solution of an active in liquid paraffin was used to prepare microspheres of water-soluble pharmaceuticals using ethylcellulose as a carrier. The effects of surfactant, plasticizer, drug loading, and agitation speed on drug release rate from the microspheres were evaluated. The release rates of water-soluble drugs from microspheres, ranging from 100 and 500 microns in diameter, were sustained over an extended time and were found to be related to the ratio of drug to polymer in the final product. PMID:2723966

  6. New polymer improves water-soluble completion fluids

    SciTech Connect

    Mondshine, T.C. )

    1989-02-01

    Water-soluble suspended salt completion fluids were first introduced in early 1977. Since then, the system has been used worldwide for various applications including gravel packing, under reaming, perforating, controlling loss of brines, washing sands, workovers, horizontal drilling, and special coring operations. More recently, a newly developed polymer simplifies and improves the design of water-soluble completion fluids. This new polymer described in this paper, is synergistic with xanthan gum, contributes to suspension of salt particles, and controls filtration at temperatures up to 300 F without the need for calcium lignosulfonate.

  7. Solubilization of poorly water-soluble drugs using solid dispersions.

    PubMed

    Tran, Thao T-D; Tran, Phuong H-L; Khanh, Tran N; Van, Toi V; Lee, Beom-Jin

    2013-08-01

    Many new drugs have been discovered in pharmaceutical industry and exposed their surprised potential therapeutic effects. Unfortunately, these drugs possess low absorption and bioavailability since their solubility limitation in water. Solid dispersion (SD) is the current technique gaining so many attractions from scientists due to its effect on improving solubility and dissolution rate of poorly water-soluble drugs. A number of patents including the most recent inventions have been undertaken in this review to address various respects of this strategy in solubilization of poorly watersoluble drugs including type of carriers, preparation methods and view of technologies used to detect SD properties and mechanisms with the aim to accomplish a SD not only effective on enhanced bioavailability but also overcome difficulties associated with stability and production. Future prospects are as well discussed with an only hope that many developments and researches in this field will be successfully reached and contributed to commercial use for treatment as much as possible. PMID:23244679

  8. A soluble copper-bipyridine water-oxidation electrocatalyst

    NASA Astrophysics Data System (ADS)

    Barnett, Shoshanna M.; Goldberg, Karen I.; Mayer, James M.

    2012-06-01

    The oxidation of water to O2 is a key challenge in the production of chemical fuels from electricity. Although several catalysts have been developed for this reaction, substantial challenges remain towards the ultimate goal of an efficient, inexpensive and robust electrocatalyst. Reported here is the first copper-based catalyst for electrolytic water oxidation. Copper-bipyridine-hydroxo complexes rapidly form in situ from simple commercially available copper salts and bipyridine at high pH. Cyclic voltammetry of these solutions at pH 11.8-13.3 shows large, irreversible currents, indicative of catalysis. The production of O2 is demonstrated both electrochemically and with a fluorescence probe. Catalysis occurs at about 750 mV overpotential. Electrochemical, electron paramagnetic resonance and other studies indicate that the catalyst is a soluble molecular species, that the dominant species in the catalytically active solutions is (2,2‧-bipyridine)Cu(OH)2 and that this is among the most rapid homogeneous water-oxidation catalysts, with a turnover frequency of ~100 s-1.

  9. Controlled release of water-soluble herbicides

    SciTech Connect

    Riggle, B.D.

    1985-01-01

    Pine kraft lignin was used to control the release of metribuzin (4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one) and alachlor (2-chloro-2',6'-diethyl-N-methoxy-methyl acetanalide). Soil thin layer chromatography (TLC) analysis using /sup 14/C-metribuzin and /sup 14/C-alachlor demonstrated that NB-5203-58 series and PC940 series kraft lignins could retard the mobility of both herbicides after multiple soil TLC plate developments with water. Soil column chromatography analysis demonstrated that PC940C could retard the mobility of both herbicides after soil column water leaching by positioning the herbicides in the top portion of the soil column where the PC940C-herbicide mixture had been applied. There was a concentration effect where, as more PC940C was used, more /sup 14/C-labelled herbicide was retained in the top portion of the soil columns. Soil column chromatography and soil TLC plate analysis demonstrated that /sup 3/H-PC940C was immobile. Finally, PC940C significantly reduced metribuzin related phytotoxicity to field and greenhouse grown soybeans (Glycine max (L.) Merr.) which had been treated with PC940C rates of 0.77 and 1.15 L/ha and metribuzin rates of 0.42 and 0.84 kg/ha. The results for /sup 14/C-metribuzin and /sup 14/C-alachlor as well as the reduction in metribuzin related phytotoxicity to soybeans suggests that PC940C can effectively control the release of metribuzin and alachlor.

  10. Preserving water soluble carbohydrate in hay and silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The water soluble carbohydrate (WSC) content of forage may be manipulated by harvest timing within a 24-hour period to take advantage of the diurnal cycle. However, increases in carbohydrate may be lost during the haymaking or ensiling process. Rapid drying and dry storage is necessary to prevent lo...

  11. Formation of water-soluble soybean polysaccharides from spent flakes by hydrogen peroxide treatment.

    PubMed

    Pierce, Brian C; Wichmann, Jesper; Tran, Tam H; Cheetamun, Roshan; Bacic, Antony; Meyer, Anne S

    2016-06-25

    In this paper we propose a novel chemical process for the generation of water-soluble polysaccharides from soy spent flake, a by-product of the soy food industry. This process entails treatment of spent flake with hydrogen peroxide at an elevated temperature, resulting in the release of more than 70% of the original insoluble material as high molar mass soluble polysaccharides. A design of experiment was used to quantify the effects of pH, reaction time, and hydrogen peroxide concentration on the reaction yield, average molar mass, and free monosaccharides generated. The resulting product is low in protein, fat, and minerals and contains predominantly water-soluble polysaccharides of high molar mass, including arabinan, type I arabinogalactan, homogalacturonan, xyloglucan, rhamnogalacturonan, and (glucurono)arabinoxylan. This treatment provides a straightforward approach for generation of soluble soy polysaccharides and opens a new range of opportunities for this abundant and underutilized material in future research and industrial applications. PMID:27083842

  12. The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.

    PubMed

    Chen, Chih-Yu; Wu, Chung-Yu; Chung, Ying-Chien

    2015-01-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminium sulphate (alum) or polyaluminium chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15 mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20 mg/l) was broader than that of acid-soluble chitosan (4-8 mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water. PMID:25362971

  13. Use of Polyvinyl Alcohol as a Solubility-Enhancing Polymer for Poorly Water Soluble Drug Delivery (Part 1).

    PubMed

    Brough, Chris; Miller, Dave A; Keen, Justin M; Kucera, Shawn A; Lubda, Dieter; Williams, Robert O

    2016-02-01

    Polyvinyl alcohol (PVAL) has not been investigated in a binary formulation as a concentration-enhancing polymer owing to its high melting point/high viscosity and poor organic solubility. Due to the unique attributes of the KinetiSol® dispersing (KSD) technology, PVAL has been enabled for this application and it is the aim of this paper to investigate various grades for improvement of the solubility and bioavailability of poorly water soluble active pharmaceutical ingredients. Solid amorphous dispersions were created with the model drug, itraconazole (ITZ), at a selected drug loading of 20%. Polymer grades were chosen with variation in molecular weight and degree of hydroxylation to determine the effects on performance. Differential scanning calorimetry, powder X-ray diffraction, polarized light microscopy, size exclusion chromatography, and dissolution testing were used to characterize the amorphous dispersions. An in vivo pharmacokinetic study in rats was also conducted to compare the selected formulation to current market formulations of ITZ. The 4-88 grade of PVAL was determined to be effective at enhancing solubility and bioavailability of itraconazole. PMID:26637232

  14. Some physicochemical aspects of water-soluble mineral flotation.

    PubMed

    Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

    2016-09-01

    Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation. PMID:27346329

  15. Dynamics of water soluble phosphorus from surface applied broiler litter.

    PubMed

    Tasistro, Armando S; Picone, Liliana; Cabrera, Miguel

    2010-08-01

    Deionized water is routinely used as an extractant to determine soluble phosphorus (P) in broiler litter, but under N.E. Georgia conditions this technique may underestimate the hazard of P loss in runoff because the alkalinity of the broiler litter-water suspension limits the solubility of P compounds that may be solubilized after being spread on acidic field conditions. In this study under controlled conditions we measured soluble P in thatch and top soil after applying untreated broiler litter, residue of broiler litter after water extraction (WER), or residue of broiler litter after extraction with a 2-(N-morpholino) ethanesulfonic acid (MES) buffer at pH 6 (BER). During the 60 d incubation, the WER released 18% more Total Dissolved P (TDP) than was determined through a conventional water extraction procedure, whereas the BER released 28% less TDP than the WER, which reflects the greater amount of TDP removed from the broiler litter by the buffer at pH 6.0. However, the total amount of TDP extracted by the MES buffer, which includes that removed at the initial extraction plus that released during the incubation, was 30% greater than the total amount of TDP extracted with water from the untreated litter plus the TDP extracted with water from the WER during the incubation. This result suggests the need to fine-tune the solid: liquid ratio and shaking time when the MES buffer is used. PMID:20661791

  16. Water solubility enhancement of some organic pollutants and pesticides by dissolved humic and fulvic acids

    USGS Publications Warehouse

    Chiou, C.T.; Malcolm, R.L.; Brinton, T.I.; Kile, D.E.

    1986-01-01

    Water solubility enhancements by dissolved humic and fulvic acids from soil and aquatic origins and by synthetic organic polymers have been determined for selected organic pollutants and pesticides (p,p???-DDT, 2,4,5,2???,5???-PCB, 2,4,4???-PCB, 1,2,3-trichlorobenzene, and lindane). Significant solubility enhancements of relatively water-insoluble solutes by dissolved organic matter (DOM) of soil and aquatic origins may be described in terms of a partition-like interaction of the the solutes with the microscopic organic environment of the high-molecular-weight DOM species; the apparent solute solubilities increase linearly with DOM concentration and show no competitive effect between solutes. With a given DOM sample, the solute partition coefficient (Kdom) increases with a decrease of solute solubility (Sw) or with an increase of the solute's octanol-water partition coefficient (Kow). The Kdom values of solutes with soil-derived humic acid are approximately 4 times greater than with soil fulvic acid and 5-7 times greater than with aquatic humic and fulvic acids. The effectiveness of DOM in enhancing solute solubility appears to be largely controlled by the DOM molecular size and polarity. The relative inability of high-molecular-weight poly(acrylic acids) to enhance solute solubility is attributed to their high polarities and extended chain structures that do not permit the formation of a sizable intramolecular nonpolar environment.

  17. Towards improved solubility of poorly water-soluble drugs: cryogenic co-grinding of piroxicam with carrier polymers.

    PubMed

    Penkina, Anna; Semjonov, Kristian; Hakola, Maija; Vuorinen, Sirpa; Repo, Timo; Yliruusi, Jouko; Aruväli, Jaan; Kogermann, Karin; Veski, Peep; Heinämäki, Jyrki

    2016-03-01

    Amorphous solid dispersions (SDs) open up exciting opportunities in formulating poorly water-soluble active pharmaceutical ingredients (APIs). In the present study, novel catalytic pretreated softwood cellulose (CPSC) and polyvinylpyrrolidone (PVP) were investigated as carrier polymers for preparing and stabilizing cryogenic co-ground SDs of poorly water-soluble piroxicam (PRX). CPSC was isolated from pine wood (Pinus sylvestris). Raman and Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) were used for characterizing the solid-state changes and drug-polymer interactions. High-resolution scanning electron microscope (SEM) was used to analyze the particle size and surface morphology of starting materials and final cryogenic co-ground SDs. In addition, the molecular aspects of drug-polymer interactions and stabilization mechanisms are presented. The results showed that the carrier polymer influenced both the degree of amorphization of PRX and stabilization against crystallization. The cryogenic co-ground SDs prepared from PVP showed an enhanced dissolution rate of PRX, while the corresponding SDs prepared from CPSC exhibited a clear sustained release behavior. In conclusion, cryogenic co-grinding provides a versatile method for preparing amorphous SDs of poorly water-soluble APIs. The solid-state stability and dissolution behavior of such co-ground SDs are to a great extent dependent on the carrier polymer used. PMID:26065533

  18. Interlaboratory Validation of Small-Scale Solubility and Dissolution Measurements of Poorly Water-Soluble Drugs.

    PubMed

    Andersson, Sara B E; Alvebratt, Caroline; Bevernage, Jan; Bonneau, Damien; da Costa Mathews, Claudia; Dattani, Rikesh; Edueng, Khadijah; He, Yan; Holm, René; Madsen, Cecilie; Müller, Thomas; Muenster, Uwe; Müllertz, Anette; Ojala, Krista; Rades, Thomas; Sieger, Peter; Bergström, Christel A S

    2016-09-01

    The purpose of this study was to investigate the interlaboratory variability in determination of apparent solubility (Sapp) and intrinsic dissolution rate (IDR) using a miniaturized dissolution instrument. Three poorly water-soluble compounds were selected as reference compounds and measured at multiple laboratories using the same experimental protocol. Dissolution was studied in fasted-state simulated intestinal fluid and phosphate buffer (pH 6.5). An additional 6 compounds were used for the development of an IDR measurement guide, which was then validated with 5 compounds. The results clearly showed a need for a standardized protocol including both the experimental assay and the data analysis. Standardization at both these levels decreased the interlaboratory variability. The results also illustrated the difficulties in performing disc IDR on poorly water-soluble drugs because the concentrations reached are typically below the limit of detection. The following guidelines were established: for compounds with Sapp >1 mg/mL, the disc method is recommended. For compounds with Sapp <100 μg/mL, IDR is recommended to be performed using powder dissolution. Compounds in the interval 100 μg/mL to 1 mg/mL can be analyzed with either of these methods. PMID:27112289

  19. Effect of water-soluble oxalates in Amaranthus spp. leaves on the absorption of milk calcium.

    PubMed

    Pingle, U; Ramasastri, B V

    1978-11-01

    1. Amaranthus spp. leaves contain high amounts of oxalates which affect the calcium absorption. This study was done to determine whether removal of the water-soluble oxalates from the leaves by cooking would reduce this deleterious effect. 2. Experimental work done with two types of basal diets on six adult male subjects has shown that the milk Ca absorption was low when leaves cooked without draining away the water were included in the diet. However when the soluble oxalates were removed by throwing away the water after cooking the leaves, the absorption of milk Ca was unaffected. PMID:568935

  20. A water-soluble ESIPT fluorescent probe with high quantum yield and red emission for ratiometric detection of inorganic and organic palladium.

    PubMed

    Gao, Tang; Xu, Pengfei; Liu, Meihui; Bi, Anyao; Hu, Pengzhi; Ye, Bin; Wang, Wei; Zeng, Wenbin

    2015-05-01

    A novel fluorescent probe with a high quantum yield (0.41), large Stokes shifts (255 nm), and red emission (635 nm) was designed to detect all typical oxidation states of palladium species (0, +2, +4) by palladium-mediated terminal propargyl ethers cleavage reaction in water solution without any organic media. The probe showed a high selectivity and excellent sensitivity for palladium species, with a detection as low as 57 nM (6.2 μg L(-1)). PMID:25757156

  1. OZONE TREATMENT OF SOLUBLE ORGANICS IN PRODUCED WATER

    SciTech Connect

    Klasson, KT

    2002-03-14

    This project was an extension of previous research to improve the applicability of ozonation and will help address the petroleum-industry problem of treating produced water containing soluble organics. The goal of this project was to maximize oxidation of hexane-extractable organics during a single-pass operation. The project investigated: (1) oxidant production by electrochemical and sonochemical methods, (2) increasing the mass transfer rate in the reactor by forming microbubbles during ozone injection into the produced water, and (3) using ultraviolet irradiation to enhance the reaction if needed. Several types of methodologies for treatment of soluble organics in synthetic and actual produced waters have been performed. The technologies tested may be categorized as follows: (1) Destruction via sonochemical oxidation at different pH, salt concentration, ultraviolet irradiation, and ferrous iron concentrations. (2) Destruction via ozonation at different pH, salt concentration, hydrogen peroxide concentrations, ultraviolet irradiation, temperature, and reactor configurations.

  2. Fabrication and Mechanical Characterization of Water-Soluble Resin-Coated Natural Fiber Green Composites

    NASA Astrophysics Data System (ADS)

    Manabe, Ken-Ichi; Hayakawa, Tomoyuki

    In this study, water-soluble biodegradable resin was introduced as a coating agent to improve the interfacial strength and then to fabricate a high-performance green composite with polylactic acid (PLA) and hemp yarn. Dip coating was carried out for hemp yarn and the green composites were fabricated by hot processing. The coated green composite achieves a high tensile strength of 117 MPa even though the fiber volume fraction is less than 30%. Interfacial shear strength (IFSS) was measured by a single fiber pull-out test, and the effect of water-soluble resin on the tensile properties of the composites was evaluated. As a result, when using coated natural bundles, the IFSS value is smaller than when using noncoated natural bundles. On the basis of observations of the fractured surface of composites and initial yarns using a scanning electron microscope (SEM), the effect of the impregnation of water-soluble resin into the natural bundles on the tensile strength is discussed in detail. It is found that water-soluble resin is effective in improving the mechanical properties of the composite, although the interfacial strength between PLA and water-soluble resin was decreased, and as a result, the tensile strength of green composites increases by almost 20%.

  3. On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility.

    PubMed

    Henao, Andres; Johnston, Andrew J; Guàrdia, Elvira; McLain, Sylvia E; Pardo, Luis Carlos

    2016-08-17

    Although they are both highly polar liquids, there are a number of compounds, such as many pharmaceuticals, which show vastly different solubilities in methanol compared with water. From theories of the hydrophobic effect, it might be predicted that this enhanced solubility is due to association between drugs and the less polar -CH3 groups on methanol. In this work, detailed analysis on the atomic structural interactions between water, methanol and the small molecule indole - which is a precursor to many drugs and is sparingly soluble in water yet highly soluble in methanol - reveal that indole preferentially interacts with both water and methanol via electrostatic interactions rather than with direction interactions to the -CH3 groups. The presence of methanol hydrogen bonds with π electrons of the benzene ring of indole can explain the increase in solubility of indole in methanol relative to water. In addition, the excess entropy calculations performed here suggest that this solvation is enthalpically rather than entropically driven. PMID:27489172

  4. [New conjugates of antitumor antibiotic doxorubicin with water-soluble galactomannan: synthesis and biological activity].

    PubMed

    Teviashova, A N; Olsuf'eva, E N; Preobrazhenskaia, M N; Klesov, A A; Zomer, E; Platt, D

    2007-01-01

    New water-soluble conjugates in the form of Schiff bases (DGM-1 and DGM-2) were prepared by the interaction of water-soluble periodate-oxidized galactomannan with doxorubicin or N-(L-lysyl)doxorubicin, respectively. The water-soluble galactomannan (DAVANAT a commercial product of Pro-Pharmaceuticals company) was obtained by partial acidic hydrolysis of high-molecular-mass galactomannan from Cyamopsis tetragonoloba (guar gum) seeds. The conjugate stability was studied in aqueous solutions. The DGM-1 antiproliferative activity was comparable with that of doxorubicin on three models: cell lines of murine melanoma B 16-F1, human breast cancer MCF-7 (HTB-22), and human colon cancer HT-29 (HTB-38). DGM-2 was poorly active in all the three tests. DGM- 1 can thus be regarded as a high-molecular-mass depot form of doxorubicin. PMID:17375669

  5. Solubility and aggregation of Gly(5) in water.

    PubMed

    Karandur, Deepti; Wong, Ka-Yiu; Pettitt, B Montgomery

    2014-08-14

    Experimentally, the solubility of oligoglycines in water decreases as its length increases. Computationally, the free energy of solvation becomes more favorable with chain length for short (n = 1-5) oligoglycines. We present results of large scale simulations with over 600 pentaglycines at varying concentrations in explicit solvent to consider the mechanism of aggregation. The solubility limit of Gly5 for the force field used was calculated and compared with experimental values. We find that intermolecular interactions between pentaglycines are favored over interactions between glycine and water, leading to their aggregation. However, the interaction driving peptide associations, liquid-liquid phase separation, are not predominantly hydrogen bonding. Instead, non-hydrogen bonding interactions between partially charged atoms on the peptide backbone allow the formation of dipole-dipole and charge layering correlations that mechanistically stabilize the formation of large, stable peptide clusters. PMID:25019618

  6. Solubility and Aggregation of Gly5 in Water

    PubMed Central

    2015-01-01

    Experimentally, the solubility of oligoglycines in water decreases as its length increases. Computationally, the free energy of solvation becomes more favorable with chain length for short (n = 1–5) oligoglycines. We present results of large scale simulations with over 600 pentaglycines at varying concentrations in explicit solvent to consider the mechanism of aggregation. The solubility limit of Gly5 for the force field used was calculated and compared with experimental values. We find that intermolecular interactions between pentaglycines are favored over interactions between glycine and water, leading to their aggregation. However, the interaction driving peptide associations, liquid–liquid phase separation, are not predominantly hydrogen bonding. Instead, non-hydrogen bonding interactions between partially charged atoms on the peptide backbone allow the formation of dipole–dipole and charge layering correlations that mechanistically stabilize the formation of large, stable peptide clusters. PMID:25019618

  7. Antioxidant Properties of Water-Soluble Fullerene Derivatives

    NASA Astrophysics Data System (ADS)

    Beuerle, Florian; Lebovitz, Russell; Hirsch, Andreas

    Due to their inherent electronic properties, fullerenes are considered as radical sponges being capable of effectively quenching reactive oxygen species (ROS). The most promising candidates for potential pharmaceutical applications are therefore water-soluble fullerene derivatives, since they provide reasonable biological availability. In light of these considerations, we give an overview over the most recent concepts for designing and synthesizing real water-soluble fullerene compounds. Several studies concerning the quenching activities against ROS-like Superoxide radical anion of some of these novel compounds are reviewed. We finally present first promising investigations about cytoprotective and neuroprotective activities of several carboxyfullerenes in zebrafish embroys as a mammalian model system. By comparing the activities for different addition patterns and other structural changes some first conclusions concerning a structure-function relationship can be drawn.

  8. Identification and determination of 34 water-soluble synthetic dyes in foodstuff by high performance liquid chromatography-diode array detection-ion trap time-of-flight tandem mass spectrometry.

    PubMed

    Li, Xiu Qin; Zhang, Qing He; Ma, Kang; Li, Hong Mei; Guo, Zhen

    2015-09-01

    An accurate method combining high performance liquid chromatography (HPLC) with diode array detection (DAD) and ion-trap time-of-flight mass spectrometry (IT-TOF/MS) was developed for simultaneous identification and quantification of 34 water-soluble synthetic dyes in foodstuff. Fragmentation patterns of synthetic dyes were proposed based on IT-TOF/MS. The molecular ion [M+H](+) was not observed in the conventional single-stage mass spectra for most of synthetic dyes. The single-stage mass spectra of synthetic dyes all afforded the diagnostic ions [(M-nNa+nH)+H](+) or [(M-nNa+nH)-H](-) in the positive or negative mode. Doubly charged ions were the characteristic ions of azo dyes. An HPLC-DAD method was developed to analyze 34 synthetic dyes in foodstuffs. The limits of detection (LOD) for the dyes were 0.01-0.05 μg/mL. The recoveries were between 76.1% and 105.0% with a RSD ranging from 1.4% to 6.4%. This method was successfully applied to analyzing the 34 water-soluble synthetic dyes in 21 commercial foods. PMID:25842343

  9. Minimalist design of water-soluble cross-[beta] architecture

    SciTech Connect

    Biancalana, Matthew; Makabe, Koki; Koide, Shohei

    2010-08-13

    Demonstrated successes of protein design and engineering suggest significant potential to produce diverse protein architectures and assemblies beyond those found in nature. Here, we describe a new class of synthetic protein architecture through the successful design and atomic structures of water-soluble cross-{beta} proteins. The cross-{beta} motif is formed from the lamination of successive {beta}-sheet layers, and it is abundantly observed in the core of insoluble amyloid fibrils associated with protein-misfolding diseases. Despite its prominence, cross-{beta} has been designed only in the context of insoluble aggregates of peptides or proteins. Cross-{beta}'s recalcitrance to protein engineering and conspicuous absence among the known atomic structures of natural proteins thus makes it a challenging target for design in a water-soluble form. Through comparative analysis of the cross-{beta} structures of fibril-forming peptides, we identified rows of hydrophobic residues ('ladders') running across {beta}-strands of each {beta}-sheet layer as a minimal component of the cross-{beta} motif. Grafting a single ladder of hydrophobic residues designed from the Alzheimer's amyloid-{beta} peptide onto a large {beta}-sheet protein formed a dimeric protein with a cross-{beta} architecture that remained water-soluble, as revealed by solution analysis and x-ray crystal structures. These results demonstrate that the cross-{beta} motif is a stable architecture in water-soluble polypeptides and can be readily designed. Our results provide a new route for accessing the cross-{beta} structure and expanding the scope of protein design.

  10. Teratogenicity and metabolism of water-soluble forms of vitamin A in the pregnant rat

    SciTech Connect

    Gunning, D.B.; Barua, A.B.; Olson, J.A. )

    1990-02-26

    Retinoyl {beta}-glucuronide, unlike retinoic acid, has been shown to be non-teratogenic when administered orally, even in large doses, to pregnant rats. The degree to which water-solubility is associated with low teratogenicity is not known. Other water-soluble forms of vitamin A have now been synthesized in our laboratory and are being evaluated for teratogenicity. New water-soluble forms of vitamin A were administered orally to pregnant Sprague-Dawley rats in a single dose of 0.35 mmole/kg bw on day 8 of gestation. On day 19, the dams were sacrificed and the litters were examined. Control animals received either vehicle only or an equivalent dose of all-trans retinoic acid. Maternal and fetal tissues were taken and analyzed by HPLC for vitamin A metabolites. In another experiment, a large single oral dose of the radiolabelled water-soluble compound was administered on day 10. At either 30 minutes or 1 hour after the dose, dams were sacrificed and the embryos analyzed both for radioactivity and for specific metabolites. In contrast to retinoyl {beta}-glucuronide, retinoyl {beta}-glucose is highly teratogenic under identical conditions. Thus, water-solubility does not seem to be the determining factor in the teratogenicity of retinoic acid conjugates.

  11. Compositional Analysis of Water-Soluble Materials in Corn Stover

    SciTech Connect

    Chen, S. F.; Mowery, R. A.; Scarlata, C. J.; Chambliss, C. K.

    2007-01-01

    Corn stover is one of the leading feedstock candidates for commodity-scale biomass-to-ethanol processing. The composition of water-soluble materials in corn stover has been determined with greater than 90% mass closure in four of five representative samples. The mass percentage of water-soluble materials in tested stover samples varied from 14 to 27% on a dry weight basis. Over 30 previously unknown constituents of aqueous extracts were identified and quantified using a variety of chromatographic techniques. Monomeric sugars (primarily glucose and fructose) were found to be the predominant water-soluble components of corn stover, accounting for 30-46% of the dry weight of extractives (4-12% of the dry weight of feedstocks). Additional constituents contributing to the mass balance for extractives included various alditols (3-7%), aliphatic acids (7-21%), inorganic ions (10-18%), oligomeric sugars (4-12%), and a distribution of oligomers tentatively identified as being derived from phenolic glycosides (10-18%).

  12. Soft water-soluble microgel dispersions: structure and rheology.

    PubMed

    Omari, A; Tabary, R; Rousseau, D; Calderon, F Leal; Monteil, J; Chauveteau, G

    2006-10-15

    The size and structural characteristics of polyacrylamide-based water-soluble microgel dispersions were investigated by optical and rheological methods. Microgel hydrodynamic radii Rh were measured by light scattering and derived from intrinsic shear viscosity [eta]0. The variations of Rh3 and [eta]0 with the crosslink density Nx, follow the scaling law Rh3 congruent withNx(-alpha) with alpha close to 0.63, in good agreement with the simple structural model proposed in this paper showing how the exact value of alpha depends on inner structural details of the microgel. The plateau viscosity versus particle apparent volume fraction shows a monotonous change from hard sphere dispersions (high crosslink density of microgels) to flexible linear polymer solutions. Measurements of the first normal stress difference N1 show that increasing the microgel crosslink density affects the system viscosity more than its elasticity. Under oscillatory shear flow, loss and storage moduli undergo both qualitative and quantitative changes with crosslink density. At moderate concentrations, the elastic modulus is the most affected and its slope in low frequency regime decreases from two to less than one as Nx increases. We discuss the experimental results within the frame of knowledge on linear, branched polymer solutions and soft microgel suspensions. PMID:16928380

  13. Photochemical and biological degradation of water-soluble FWAs.

    PubMed

    Guglielmetti, L

    1975-01-01

    A study was made of the photochemical and biological degradation of two water-soluble fluorescent whitening agents (FWAs): the disodium 4,4'-bis(2-sulfostyryl)-biphenyl (1) and the disodium 4,4-bis ([4-anilino-6-(N-methyl-N-2-hydroxyethyl)amino 1,3,5-triazin-2-yl]amino)stilbene-2,2'-disulfonate (2). Each represents an important class of detergent fluorescent whitening agents. The photochemical degradation of (1) was studied by irradiating diluted aqueous solutions of this compound with a low intensity high pressure mercury vapor lamp. From the intermediate, as well as the ultimate photodegradation products isolated, it can be infered that photodegradation of (1) followed the proposed scheme. The biologica degradation of (1) and (2) by activated sludge under aerobic conditions was studied using equipment similar to that proposed by the OECD for determining the biodegradation of anionic synthetic surface active agents. Under the conditons applied, both FWAs were slowly biodegraded, within 30 days, whereas the photodegradation products of (1) were completely biodegraded within 14 days. PMID:6265

  14. Organic compounds in hot-water-soluble fractions from water repellent soils

    NASA Astrophysics Data System (ADS)

    Atanassova, Irena; Doerr, Stefan

    2014-05-01

    Water repellency (WR) is a soil property providing hydrophobic protection and preventing rapid microbial decomposition of organic matter entering the soil with litter or plant residues. Global warming can cause changes in WR, thus influencing water storage and plant productivity. Here we assess two different approaches for analysis of organic compounds composition in hot water extracts from accelerated solvent extraction (ASE) of water repellent soils. Extracts were lyophilized, fractionated on SiO2 (sand) and SPE cartridge, and measured by GC/MS. Dominant compounds were aromatic acids, short chain dicarboxylic acids (C4-C9), sugars, short chain fatty acids (C8-C18), and esters of stearic and palmitic acids. Polar compounds (mainly sugars) were adsorbed on applying SPE clean-up procedure, while esters were highly abundant. In addition to the removal of polar compounds, hydrophobic esters and hydrocarbons (alkanes and alkenes < C20) were extracted through desorption of complex colloids stabilized as micelles in dissolved organic carbon (DOC). Water repellency was completely eliminated by hot water under high pressure. The molecular composition of HWSC can play a critical role in stabilization and destabilization of soil organic matter (SOM), particle wettability and C dynamics in soils. Key words: soil water repellency, hot water soluble carbon (HWSC), GC/MS, hydrophobic compounds

  15. Generating Water-Soluble Noxious Gases: An Overhead Projector Demonstration

    NASA Astrophysics Data System (ADS)

    Solomon, Sally; Oliver-Hoyo, Maria; Hur, Chinhyu

    1998-12-01

    A simple, inexpensive apparatus to generate and collect water-soluble noxious gases as an overhead projector demonstration can be made from two small beakers and a Petri dish. The detection and generation of sulfur dioxide and nitrogen dioxide are described. Sulfur dioxide dissolved in water is detected using an acid-base indicator, decolorizing of anthocyanin, or reduction of permanganate. The SO2 is generated by addition of sulfite or bisulfite to a strong acid or by the addition of concentrated sulfuric acid to sugars. Nitrogen dioxide is generated by mixing copper and nitric acid and detected using an acid-base indicator.

  16. Picosecond dynamics in water-soluble azobenzene-peptides

    NASA Astrophysics Data System (ADS)

    Satzger, H.; Root, C.; Renner, C.; Behrendt, R.; Moroder, L.; Wachtveitl, J.; Zinth, W.

    2004-09-01

    Ultrafast absorption changes are recorded for water-soluble cyclic azobenzene peptides containing the photoswitch (4-aminomethyl)-phenyl-azobenzoic acid (AMPB) and a bioactive peptide motif. They can be separated into the fast reactions in the AMPB chromophore and the slower response of the peptide moiety. While the fastest reactions display similar time constants as observed for AMPB peptides dissolved in DMSO the slower reaction dynamics assigned to vibrational cooling and motions of the peptide moiety are faster in water by a factor of up to two. The changes in the reaction times are explained by solvent heat capacity and viscosity.

  17. Solubility of the Sodium and Ammonium Salts of Oxalic Acid in Water with Ammonium Sulfate.

    PubMed

    Buttke, Lukas G; Schueller, Justin R; Pearson, Christian S; Beyer, Keith D

    2016-08-18

    The solubility of the sodium and ammonium salts of oxalic acid in water with ammonium sulfate present has been studied using differential scanning calorimetry, X-ray crystallography, and infrared spectroscopy. The crystals that form from aqueous mixtures of ammonium sulfate/sodium hydrogen oxalate were determined to be sodium hydrogen oxalate monohydrate under low ammonium sulfate conditions and ammonium hydrogen oxalate hemihydrate under high ammonium sulfate conditions. Crystals from aqueous mixtures of ammonium sulfate/sodium oxalate were determined to be ammonium oxalate monohydrate under moderate to high ammonium sulfate concentrations and sodium oxalate under low ammonium sulfate concentrations. It was also found that ammonium sulfate enhances the solubility of the sodium oxalate salts (salting in effect) and decreases the solubility of the ammonium oxalate salts (salting out effect). In addition, a partial phase diagram for the ammonium hydrogen oxalate/water system was determined. PMID:27482644

  18. The Significance of Interfacial Water Structure in Soluble Salt Flotation Systems.

    PubMed

    Hancer, M.; Celik, M. S.; Miller, J. D.

    2001-03-01

    Flotation of soluble salts with dodecyl amine hydrochloride (DAH) and sodium dodecyl sulfate (SDS) collectors has demonstrated that the interfacial water structure and hydration states of soluble salt surfaces together with the precipitation tendency of the corresponding collector salts are of considerable importance in explaining their flotation behavior. In particular, the high concentration of ions in these soluble salt brines and their hydration appear to modify the bulk and interfacial structure of water as revealed by contact angle measurements and this effect is shown to be an important feature in the flotation chemistry of soluble salt minerals including alkali halide and alkali oxyanion salts. Depending on characteristic chemical features (salt type), the salt can serve either as a structure maker, in which intermolecular hydrogen bonding between water molecules is facilitated, or as a structure breaker, in which intermolecular hydrogen bonding between water molecules is disrupted. For structure making salts the brine completely wets the salt surface and no contact angle can be measured. For structure breaking salts the brine does not completely wet the salt surface and a finite contact angle is measured. In this regard it has been found that soluble salt flotation either with the cationic DAH or anionic SDS collector is possible only if the salt is a structure breaker. Copyright 2001 Academic Press. PMID:11237454

  19. Photochemistry within a water-soluble organic capsule.

    PubMed

    Ramamurthy, Vaidhyanathan

    2015-11-17

    Photochemistry along with life as we know it originated on earth billions of years ago. Supramolecular Photochemistry had its beginning when plants that sustain life began transforming water into oxygen by carrying out light initiated reactions within highly organized assemblies. Prompted by the efforts of J. Priestly (photosynthesis), F. Sestini, S. Cannizaro, and C. Liebermann (solid-state photochemistry of santonin, quinones, and cinnamic acid), orderly scientific investigations of the link between light absorption by matter and molecules and the chemical and physical consequences began in the mid-1700s. By 1970 when Molecular Photochemistry had matured, it was clear that controlling photochemical reactions by conventional methods of varying reaction parameters like temperature and pressure would be futile due to the photoreactions' very low activation energies and enthalpies. During the last 50 years, the excited state behavior of molecules has been successfully manipulated with the use of confining media and weak interactions between the medium and the reactant molecule. In this context, with our knowledge from experimentation with micelles, cyclodextrins (CD), cucurbitruils (CB), calixarenes (CA), Pd nanocage, crystals, and zeolites as media, we began about a decade ago to explore the use of a new water-soluble synthetic organic cavitand, octa acid (OA) as a reaction container. The uniqueness of OA as an organic cavitand lies in that two OA molecules form a closed hydrophobic capsule to encapsulate water-insoluble guest molecule(s). The ability to include a large number of guest molecules in OA has provided an opportunity to examine the excited state chemistry of organic molecules in a hydrophobic, confined environment. OA distinguishes itself from the well-known cavitands CD and CB by its active reaction cavity absorbing UV-radiation between 200 and 300 nm and serving as energy, electron, and hydrogen donor. The freedom of guest molecules in OA, between that

  20. Water-Soluble 2-Hydroxyisophthalamides for Sensitization of Lanthanide Luminescence

    SciTech Connect

    Samuel, Amanda P. S.; Moore, Evan G.; Melchior, Marco; Xu, Jide; Raymond, Kenneth N.

    2008-02-20

    A series of octadentate ligands featuring the 2-hydroxyisophthalamide (IAM) antenna chromophore (to sensitize Tb(III) and Eu(III) luminescence) has been prepared and characterized. The length of the alkyl amine scaffold that links the four IAM moieties has been varied in order to investigate the effect of the ligand backbone on the stability and photophysical properties of the Ln(III) complexes. The amine backbones utilized in this study are N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-ethane-1,2-diamine [H(2,2)-], N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-propane-1,3-diamine [H(3,2)-] and N,N,N{prime},N{prime}-tetrakis-(2-aminoethyl)-butane-1,4-diamine [H(4,2)-]. These ligands also incorporate methoxyethylene [MOE] groups on each of the IAM chromophores to increase their water solubility. The aqueous ligand protonation constants and Tb(III) and Eu(III) formation constants were determined from solution thermodynamic studies. The resulting values indicate that at physiological pH, the Eu(III) and Tb(III) complexes of H(2,2)-IAM-MOE and H(4,2)-IAM-MOE are sufficiently stable to prevent dissociation at nanomolar concentrations. The photophysical measurements for the Tb(III) complexes gave overall quantum yield values of 0.56, 0.39, and 0.52 respectively for the complexes with H(2,2)-IAM-MOE, H(3,2)-IAM-MOE and H(4,2)-IAM-MOE, while the corresponding Eu(III) complexes displayed significantly weaker luminescence, with quantum yield values of 0.0014, 0.0015, and 0.0058, respectively. Analysis of the steady state Eu(III) emission spectra provides insight into the solution symmetries of the complexes. The combined solubility, stability and photophysical performance of the Tb(III) complexes in particular make them well suited to serve as the luminescent reporter group in high sensitivity time-resolved fluoroimmunoassays.

  1. Water-Soluble 2-Hydroxyisophthalamides for Sensitization of Lanthanide Luminescence

    PubMed Central

    Samuel, Amanda P. S.; Moore, Evan G.; Melchior, Marco; Xu, Jide; Raymond, Kenneth N.

    2011-01-01

    A series of octadentate ligands featuring the 2-hydroxyisophthalamide (IAM) antenna chromophore (to sensitize Tb(III) and Eu(III) luminescence) has been prepared and characterized. The length of the alkyl amine scaffold that links the four IAM moieties has been varied in order to investigate the effect of the ligand backbone on the stability and photophysical properties of the Ln(III) complexes. The amine backbones utilized in this study are N,N,N',N'-tetrakis-(2-aminoethyl)-ethane-1,2-diamine [H(2,2)-], N,N,N',N'-tetrakis-(2-aminoethyl)-propane-1,3-diamine [H(3,2)-] and N,N,N',N'-tetrakis-(2-aminoethyl)-butane-1,4-diamine [H(4,2)-]. These ligands also incorporate methoxyethylene [MOE] groups on each of the IAM chromophores to increase their water solubility. The aqueous ligand protonation constants and Tb(III) and Eu(III) formation constants were determined from solution thermodynamic studies. The resulting values indicate that at physiological pH, the Eu(III) and Tb(III) complexes of H(2,2)-IAM-MOE and H(4,2)-IAM-MOE are sufficiently stable to prevent dissociation at nanomolar concentrations. The photophysical measurements for the Tb(III) complexes gave overall quantum yield values of 0.56, 0.39, and 0.52 respectively for the complexes with H(2,2)-IAM-MOE, H(3,2)-IAM-MOE and H(4,2)-IAM-MOE, while the corresponding Eu(III) complexes displayed significantly weaker luminescence, with quantum yield values of 0.0014, 0.0015, and 0.0058, respectively. Analysis of the steady state Eu(III) emission spectra provides insight into the solution symmetries of the complexes. The combined solubility, stability and photophysical performance of the Tb(III) complexes in particular make them well suited to serve as the luminescent reporter group in high sensitivity time-resolved fluoroimmunoassays. PMID:18671388

  2. Fabrication and multifunctional properties of ultrasmall water-soluble tungsten oxide quantum dots.

    PubMed

    Peng, Huaping; Liu, Pan; Lin, Danwei; Deng, Yani; Lei, Yun; Chen, Wei; Chen, Yuanzhong; Lin, Xinhua; Xia, Xinghua; Liu, Ailin

    2016-07-21

    A facile and green method has been demonstrated to synthesize ultrasmall tungsten oxide quantum dots (WOx QDs). The water-soluble WOx QDs present high luminescence stability, strong peroxidase-like activity, and excellent electrochemiluminescence properties. This work provides an eco-friendly strategy to prepare multifunctional WOx QDs, and opens the door for bioapplications of the WOx QDs. PMID:27381501

  3. Experimenting with Water. Factors Affecting the Solubility of Substances in Water.

    ERIC Educational Resources Information Center

    Bourgeois, Simone P.; And Others

    1986-01-01

    Presents a module that focuses on the solvent property of water. Indicates the knowledge items, skills, processes, and attitudes that are developed in the unit. Includes background information as well as student directions for an experiment on solubility. (ML)

  4. Water-soluble lead in cathode ray tube funnel glass melted in a reductive atmosphere.

    PubMed

    Okada, Takashi

    2016-10-01

    In the reduction-melting process, lead can be recovered from cathode ray tube funnel glass (PbO=25wt%); however, resulting glass residues still contain approximately 1-2wt% of unrecovered lead. For environmental protection in the residue disposal or recycling, it is important to evaluate the quantities of water-soluble species among the unrecovered lead. This study examined water-soluble lead species generated in the reduction-melting process of the funnel glass and factors determining their generation. In the reduction-melting, metallic lead was generated by reducing lead oxides in the glass, and a part of the metallic lead remained in the glass residue. Such unrecovered metallic lead can dissolve in water depending on its pH level and was regarded as water-soluble lead. When 10g Na2CO3 was added to 20g funnel glass during reduction-melting, the resulting glass contained high concentrations of sodium. In a water leaching of the glass, the obtained leachate was alkalized by the sodium-rich glass (pH=12.7-13.0). The unrecovered metallic lead in the glass was extracted in the alkalized leachate. The quantity of the unrecovered metallic lead (water-soluble lead) in the glass decreased when the melting time, melting temperature, and carbon dosage were controlled during reduction-melting. PMID:27209518

  5. Water-soluble pesticides in finished water of community water supplies

    USGS Publications Warehouse

    Coupe, R.H.; Blomquist, J.D.

    2004-01-01

    Although considerable data have been published on the occurrence and distribution of pesticides in surface water, there is little information from full-scale studies on how pesticides in source water are affected by the treatment process. In this pilot study, source water and finished (treated) water samples were collected from 12 community water systems (CWSs) across the United States and analyzed for water-soluble pesticides. The facilities were selected in part because they relied on surface water as their source water and their supplies were considered vulnerable to pesticide contamination. A treatment plant's, ability to remove or degrade a pesticide has been shown to be dependent on numerous variables, including surface water characteristics, pH, oxidant type, contact time, and operational procedures. Among the 12 CWSs tracked by this research, the treatment processes effectiveness varied significantly. Although some pesticides in the source water were removed by treatment, others passed through the treatment process and into the distribution system. Future study is needed to examine exactly how the treatment process within each of the participating systems affected pesticide concentration. None of the pesticides, analyzed in this research were found at concentrations above standards set by the US Environmental Protection Agency for treated water. However, this work should serve as a wake-up call for treatment personnel and facility managers: If their source water is contaminated with pesticides, then the treatment process may not be completely effective at removing these pesticides from the water. - MPM.

  6. Water Solubility Studies in Lower Mantle Perovskite by Fourier Transform Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Amulele, G.; Otsuka, K.; Sanchez, C.; Lee, K. K.; Karato, S.; Liu, Z.; Chen, Z.

    2010-12-01

    Although the water solubility in lower mantle minerals is critical for understanding of global water circulation, the water solubility in lower mantle minerals is poorly constrained. The water solubility in MgSiO3-perovskite as well as Al-bearing MgSiO3-perovskite synthesized at 1500 - 1600 K and 24 - 25 GPa under SiO2 or MgO saturated conditions have been investigated by FTIR spectroscopy both at ambient as well as modest pressures of up to 10 GPa in a diamond-anvil cell using KBr as a pressure medium. The FTIR spectra show one dominant band at 3440 cm-1 in MgSiO3-perovskite corresponding to about 50 - 70 ppm wt water in the perovskite. This is consistent with the results by Litasov et al. (2003) who obtained solubility of about 100 ppm wt water in MgSiO3-perovskite, but much larger than the values reported by Bolfan-Casanova et al. (2000). Based on the in-situ FTIR in a diamond-anvil cell using KCl as a pressure medium, Reid et al. (2006) reported infrared absorption peaks at 3160 and 3066 cm-1 at high pressures that broaden and weaken at low (<3 GPa) pressures. They interpreted that these peak are caused by unquenchable hydroxyl-related species. However, we did not find these peaks but instead we found these peaks from the FTIR spectroscopy of KCl. We conclude that 3160 and 3060 cm-1 peaks are due to KCl, and MgSiO3 perovskite has small but finite water solubility (~50-70 ppm wt) that is expected to increase with Al content. We also present corresponding high-pressure x-ray diffraction measurements on the nominally hydrous MgSiO3-perovskite carried out up to 30 GPa.

  7. Spray deposition of water-soluble multiwall carbon nanotube and Cu2ZnSnSe4 nanoparticle composites as highly efficient counter electrodes in a quantum dot-sensitized solar cell system

    NASA Astrophysics Data System (ADS)

    Zeng, Xianwei; Xiong, Dehua; Zhang, Wenjun; Ming, Liqun; Xu, Zhen; Huang, Zhanfeng; Wang, Mingkui; Chen, Wei; Cheng, Yi-Bing

    2013-07-01

    In this paper, low-cost counter electrodes (CEs) based on water-soluble multiwall carbon nanotube (MWCNT) and Cu2ZnSnSe4 nanoparticle (CZTSe NP) composites have been successfully introduced into a quantum dot-sensitized solar cell (QDSC) system. Suitable surface modification allows the MWCNTs and CZTSe NPs to be homogeneously dispersed in water, facilitating the subsequent low-temperature spray deposition of high quality composite films with different composite ratios. The electrochemical catalytic activity of the composite CEs has been critically compared by electrochemical impedance spectroscopy and Tafel-polarization analysis. It is found that the composite CE at the MWCNT : CZTSe ratio of 0.1 offers the best performance, leading to an optimal solar cell efficiency of 4.60%, which is 50.8% higher than that of the Pt reference CE. The as-demonstrated higher catalytic activity of the composite CEs compared to their single components could be ascribed to the combination of the fast electron transport of the MWCNTs and the high catalytic activity of CZTSe NPs.In this paper, low-cost counter electrodes (CEs) based on water-soluble multiwall carbon nanotube (MWCNT) and Cu2ZnSnSe4 nanoparticle (CZTSe NP) composites have been successfully introduced into a quantum dot-sensitized solar cell (QDSC) system. Suitable surface modification allows the MWCNTs and CZTSe NPs to be homogeneously dispersed in water, facilitating the subsequent low-temperature spray deposition of high quality composite films with different composite ratios. The electrochemical catalytic activity of the composite CEs has been critically compared by electrochemical impedance spectroscopy and Tafel-polarization analysis. It is found that the composite CE at the MWCNT : CZTSe ratio of 0.1 offers the best performance, leading to an optimal solar cell efficiency of 4.60%, which is 50.8% higher than that of the Pt reference CE. The as-demonstrated higher catalytic activity of the composite CEs compared to

  8. Dithiocarbamates as capping ligands for water-soluble quantum dots.

    PubMed

    Zhang, Yanjie; Schnoes, Allison M; Clapp, Aaron R

    2010-11-01

    We investigated the suitability of dithiocarbamate (DTC) species as capping ligands for colloidal CdSe-ZnS quantum dots (QDs). DTC ligands are generated by reacting carbon disulfide (CS(2)) with primary or secondary amines on appropriate precursor molecules. A biphasic exchange procedure efficiently replaces the existing hydrophobic capping ligands on the QD surface with the newly formed DTCs. The reaction conversion is conveniently monitored by UV-vis absorption spectroscopy. Due to their inherent water solubility and variety of side chain functional groups, we used several amino acids as precursors in this reaction/exchange procedure. The performance of DTC-ligands, as evaluated by the preservation of luminescence and colloidal stability, varied widely among amino precursors. For the best DTC-ligand and QD combinations, the quantum yield of the water-soluble QDs rivaled that of the original hydrophobic-capped QDs dispersed in organic solvents. The mean density of DTC-ligands per nanocrystal was estimated through a mass balance calculation which suggested nearly complete coverage of the available nanocrystal surface. The accessibility of the QD surface was evaluated by self-assembly of His-tagged dye-labeled proteins and peptides using fluorescence resonance energy transfer. DTC-capped QDs were also exposed to cell cultures to evaluate their stability and potential use for biological applications. In general, DTC-capped CdSe-ZnS QDs have many advantages over other water-soluble QD formulations and provide a flexible chemistry for controlling the QD surface functionalization. Despite previous literature reports of DTC-stabilized nanocrystals, this study is the first formal investigation of a biphasic exchange method for generating biocompatible core-shell QDs. PMID:21053924

  9. Chelating water-soluble polymers for waste minimization

    SciTech Connect

    Smith, B.; Cournoyer, M.; Duran, B.; Ford, D.; Gibson, R.; Lin, M.; Meck, A.; Robinson, P.; Robison, T.

    1996-11-01

    Within the DOE complex and in industry there is a tremendous need for advanced metal ion recovery and waste minimization techniques. This project sought to employ capabilities for ligand-design and separations chemistry in which one can develop and evaluate water- soluble chelating polymers for recovering actinides and toxic metals from various process streams. Focus of this work was (1) to develop and select a set of water-soluble polymers suitable for a selected waste stream and (2) demonstrate this technology in 2 areas: removal of (a) actinides and toxic RCRA metals from waste water and (b) recovery of Cu and other precious metals from industrial process streams including from solid catalysts and aqueous waste streams. The R&D was done in 4 phases for each of the 2 target areas: polymer synthesis for scaleup, equipment assembly, process demonstration at a DOE or industrial site, and advanced ligand/polymer synthesis. The TA- 50 site at Los Alamos was thought to be appropriate due to logistics and to its being representative of similar problems throughout the DOE complex.

  10. Water soluble fluorescence quantum dot probe labeling liver cancer cells.

    PubMed

    Chang, Baoxing; Yang, Xianjun; Wang, Fang; Wang, Yinsong; Yang, Rui; Zhang, Ning; Wang, Baiqi

    2013-11-01

    Water soluble quantum dots (QDs) have been prepared by hydrothermal method and characterized by ultraviolet irradiation, XRD, TEM, UV-Vis absorption spectrometer and fluorescence spectrometer. Then the QD-antibody-AFP probes (QD-Ab-AFP) were synthesized by chemical process and specifically labeled AFP antigen in PLC/PRF/5 liver cancer cells. The results showed that the QDs were cubic structure and had excellent optical properties. Moreover, the QD-Ab-AFP with good stability could specifically label liver cancer cells. This work provides strong foundation for further studying and developing new approach to detect liver cancer at early stage. PMID:23888351

  11. Applications of water-soluble polymers in the oil field

    SciTech Connect

    Chatterji, J.; Borchardt, J.K.

    1981-11-01

    Water-soluble polymers commonly used in the oil field are reviewed. The properties of guar, guar derivatives, cellulose derivatives, xanthan gum, locust bean gum, starches, and synthetic polymers, especially polyacrylamides, are discussed and related to chemical structures of the polymers. Original data comparing polymer solution viscosity properties under identical conditions are presented. These data include effect of polymer concentration on solution viscosity, temperature effect on solution viscosity, viscosity in acidic solution, and polymer solution viscosity in the presence of a hemicellulase enzyme. 105 refs.

  12. Multiple sources of soluble atmospheric iron to Antarctic waters

    NASA Astrophysics Data System (ADS)

    Winton, V. H. L.; Edwards, R.; Delmonte, B.; Ellis, A.; Andersson, P. S.; Bowie, A.; Bertler, N. A. N.; Neff, P.; Tuohy, A.

    2016-03-01

    The Ross Sea, Antarctica, is a highly productive region of the Southern Ocean. Significant new sources of iron (Fe) are required to sustain phytoplankton blooms in the austral summer. Atmospheric deposition is one potential source. The fractional solubility of Fe is an important variable determining Fe availability for biological uptake. To constrain aerosol Fe inputs to the Ross Sea region, fractional solubility of Fe was analyzed in a snow pit from Roosevelt Island, eastern Ross Sea. In addition, aluminum, dust, and refractory black carbon (rBC) concentrations were analyzed, to determine the contribution of mineral dust and combustion sources to the supply of aerosol Fe. We estimate exceptionally high dissolved Fe (dFe) flux of 1.2 × 10-6 g m-2 y-1 and total dissolvable Fe flux of 140 × 10-6 g m-2 y-1 for 2011/2012. Deposition of dust, Fe, Al, and rBC occurs primarily during spring-summer. The observed background fractional Fe solubility of ~0.7% is consistent with a mineral dust source. Radiogenic isotopic ratios and particle size distribution of dust indicates that the site is influenced by local and remote sources. In 2011/2012 summer, relatively high dFe concentrations paralleled both mineral dust and rBC deposition. Around half of the annual aerosol Fe deposition occurred in the austral summer phytoplankton growth season; however, the fractional Fe solubility was low. Our results suggest that the seasonality of dFe deposition can vary and should be considered on longer glacial-interglacial timescales.

  13. Antioxidant Activity of Water-soluble Polysaccharides from Brasenia schreberi

    PubMed Central

    Xiao, Huiwen; Cai, Xueru; Fan, Yijun; Luo, Aoxue

    2016-01-01

    Objective: In order to investigate the antioxidant activities of polysaccharides (BPL-1 and BPL-2), one of the most important functional constituents in Brasenia schreberi was isolated from the external mucilage of B. schreberi (BPL-1) and the plant in vivo (BPL-2). This paper examines the relationship between the content of sulfuric radicals and uronic acid in BPL and the antioxidant activity of BPL. Materials and Methods: The free radicals, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and 1,1-diphnyl-2-picrylhydrazyl (DPPH-), were used to determine the antioxidant activity of BPL. The Fourier-transform infrared spectroscopy of BPL-1 and BPL-2 revealed typical characteristics of polysaccharides. Results: The two sample types had different contents. This was proved by their different adsorption peak intensities. The IC50 values of BPL-1 (31.189 mg/ml) and BPL-2 (1.863 mg/ml) showed significant DPPH radical scavenging activity. Based on the quantification of ABTS radical scavenging, the IC50 value of BPL-1 (5.460 mg/ml) was higher than that of BPL-2 (0.239 mg/ml). Therefore, in terms of the reducing power, the IC50 value of BPL-1 was too high to determine, and the IC50 value of BPL-2 was found to be 50.557 mg/ml. Hence, the antioxidant activity and total reducing power were high, and they were greater in BPL-2 than in BPL-1. In addition, BPL-2 was found to have more sulfuric radicals and uronic acid than BPL-1. Conclusion: The contents of sulfuric radicals and uronic acid are significantly correlated to the antioxidant activity and reducing power of BPL; the more sulfuric radicals and uronic acid, the more antioxidant activity and reducing power BPL has. SUMMARY The water-soluble crude polysaccharides obtained from the external mucilage and the Brasenia schreberi plant in vivo were confirmed to have high contents of sulfuric radicals and uronic acidBoth BPL-1 and BPL-2 exhibited antioxidative activity and reducing power, and their antioxidative

  14. Investigating water soluble organic aerosols: Sources and evolution

    NASA Astrophysics Data System (ADS)

    Hecobian, Arsineh N.

    Many studies are being conducted on the different properties of organic aerosols (OA-s) as it is first emitted into the atmosphere and the consequent changes in these characteristics as OA-s age and secondary organic aerosol (SOA) is produced and in turn aged. This thesis attempts to address some of the significant and emerging issues that deal with the formation and transformation of water-soluble organic aerosols in the atmosphere. First, a proven method for the measurement of gaseous sulfuric acid, negative ion chemical ionization mass spectrometry (CIMS), has been modified for fast and sensitive measurements of particulate phase sulfuric acid (i.e. sulfate). The modifications implemented on this system have also been the subject of preliminary verifications for measurements of aerosol phase oxalic acid (an organic acid). Second, chemical and physical characteristics of a wide range of biomass-burning plumes intercepted by the NASA DC-8 research aircraft during the three phases of the ARCTAS experiment are presented here. A statistical summary of the emission (or enhancement) ratios relative to carbon monoxide is presented for various gaseous and aerosol species. Extensive investigations of fire plume evolutions were undertaken during the second part of this field campaign. For four distinct Boreal fires, where plumes were intercepted by the aircraft over a wide range of down-wind distances, emissions of various compounds and the effect of aging on them were investigated in detail. No clear evidence of production of secondary compounds (e.g., WSOC and OA) was observed. High variability in emissions between the different plumes may have obscured any clear evidence of changes in the mass of various species with increasing plume age. Also, the lack if tropospheric oxidizing species (e.g., O3 and OH) may have contributed to the lack of SOA formation. Individual intercepts of smoke plumes in this study were segregated by source regions. The normalized excess mixing

  15. Optimization of simultaneous ultrasonic-assisted extraction of water-soluble and fat-soluble characteristic constituents from Forsythiae Fructus Using response surface methodology and high-performance liquid chromatography

    PubMed Central

    Xia, Yong-Gang; Yang, Bing-You; Liang, Jun; Wang, Di; Yang, Qi; Kuang, Hai-Xue

    2014-01-01

    Background: The compounds (+)-pinoresinol-β-glucoside (1) forsythiaside, (2) phillyrin (3) and phillygenin (4) were elucidated to be the characteristic constituents for quality control of Forsythiae Fructus extract by chromatographic fingerprint in 2010 edition of Chinese Pharmacopoeia due to their numerous important pharmacological actions. It is of great interest to extract these medicinally active constituents from Forsythiae Fructus simultaneously. Materials and Methods: In this study, a new ultrasound-assisted extraction (UAE) method was developed for the simultaneous extraction of biological components 1-4 in Forsythiae Fructus. The quantitative effects of extraction time, ratio of liquid to solid, extraction temperature, and methanol concentration on yield of these four important biological constituents from Forsythiae Fructus were investigated using response surface methodology with Box-Behnken design. The compounds 1-4 extracted by UAE were quantitative analysis by high-performance liquid chromatography-photodiode array detect (HPLC-PAD), and overall desirability (OD), the geometric mean of the contents of four major biological components, was used as a marker to evaluate the extraction efficiency. Results: By solving the regression equation and analyzing 3-D plots, the optimum condition was at extraction temperature 70°C, time 60 min, ratio of liquid to solid 20, and methanol concentration 76.6%. Under these conditions, extraction yields of compounds 1-4 were 2.92 mg/g, 52.10 mg/g, 0.90 mg/g and 0.57 mg/g, respectively, which were in good agreement with the predicted OD values. In order to achieve a similar yield as UAE, soxhlet extraction required at least 6 h and maceration extraction required much longer time of 24 h. Established UAE method has been successfully applied to sample preparation for the quality control of Forsythiae Fructus. Additionally, a quadrupole time-of-flight mass spectrometry was applied to the structural confirmation of analytes

  16. 40 CFR 799.6784 - TSCA water solubility: Column elution method; shake flask method.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false TSCA water solubility: Column elution... AND MIXTURE TESTING REQUIREMENTS Product Properties Test Guidelines § 799.6784 TSCA water solubility... here may not yet be optimal. This method is intended for material with solubilities below...

  17. 40 CFR 799.6784 - TSCA water solubility: Column elution method; shake flask method.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false TSCA water solubility: Column elution... AND MIXTURE TESTING REQUIREMENTS Product Properties Test Guidelines § 799.6784 TSCA water solubility... here may not yet be optimal. This method is intended for material with solubilities below...

  18. 40 CFR 799.6784 - TSCA water solubility: Column elution method; shake flask method.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false TSCA water solubility: Column elution... AND MIXTURE TESTING REQUIREMENTS Product Properties Test Guidelines § 799.6784 TSCA water solubility... here may not yet be optimal. This method is intended for material with solubilities below...

  19. Heat-induced formation of myosin oligomer-soluble filament complex in high-salt solution.

    PubMed

    Shimada, Masato; Takai, Eisuke; Ejima, Daisuke; Arakawa, Tsutomu; Shiraki, Kentaro

    2015-02-01

    Heat-induced aggregation of myosin into an elastic gel plays an important role in the water-holding capacity and texture of meat products. Here, we investigated thermal aggregation of porcine myosin in high-salt solution over a wide temperature range by dynamic light scattering experiments. The myosin samples were readily dissolved in 1.0 M NaCl at 25 °C followed by dilution into various salt concentrations. The diluted solutions consistently contained both myosin monomers and soluble filaments. The filament size decreased with increasing salt concentration and temperature. High temperatures above Tm led to at least partial dissociation of soluble filaments and thermal unfolding, resulting in the formation of soluble oligomers and binding to the persistently present soluble filaments. Such a complex formation between the oligomers and filaments has never been observed. Our results provide new insight into the heat-induced myosin gelation in high-salt solution. PMID:25445683

  20. Estrogenic profile on a water-soluble estrogen, estrazinol hydrobromide.

    PubMed

    Rassaert, C L; DiPasquale, G; Giannina, T; Manning, J P; Meli, A

    1973-01-01

    The estrogenic properties of estrazinol hydrobromide (EZ), a water-soluble estrogen, were compared with those of Premarin (PR), another water-soluble estrogen preparation consisting of conjugated equine estrogens. Estradiol-17beta, estra-1,3,5(10)-triene-3,17beta-diol (E), and ethinyl estradiol, 17alpha-ethinyl-1,3,5 (10)-estratriene-3,17beta-diol (EE) were used as reference standards. Subcutaneous progesterone (400 mcg) given to rabbits primed with comparable subcutaneous doses of either E or EE produced full secretory changes of the endometrium, while such a transformation could not be elicited in orally primed animals regardless of the estrogen used. The biological profile or orally administered EZ was very similar to that of oral EE and different from oral PR. Howerver, the oral EZ-induced morphological changes of the rabbit endometrium appeared somewhat different from those produced by oral EE. The findings indicated that following oral administration, EZ-induced endometrial transformation is more "normal" and/or adequate than the changes produced by either EE or PR. PMID:4368700

  1. ESTIMATION OF WATER SOLUBILITY AND OCTANOL/WATER PARTITION COEFFICIENT OF HYDROPHOBIC DYES - PART I. RELATIONSHIP BETWEEN SOLUBILITY AND PARTITION COEFFICIENT

    EPA Science Inventory

    Three regression approaches are examined for use in estimating water solubilities and octanol/water partition coefficients, two fundamental equilibrium constants that are widely used predicting the fate of organic chemicals in aquatic systems. pproaches examined are regression of...

  2. Self-assembly of water-soluble nanocrystals

    DOEpatents

    Fan, Hongyou; Brinker, C. Jeffrey; Lopez, Gabriel P.

    2012-01-10

    A method for forming an ordered array of nanocrystals where a hydrophobic precursor solution with a hydrophobic core material in an organic solvent is added to a solution of a surfactant in water, followed by removal of a least a portion of the organic solvent to form a micellar solution of nanocrystals. A precursor co-assembling material, generally water-soluble, that can co-assemble with individual micelles formed in the micellar solution of nanocrystals can be added to this micellar solution under specified reaction conditions (for example, pH conditions) to form an ordered-array mesophase material. For example, basic conditions are used to precipitate an ordered nanocrystal/silica array material in bulk form and acidic conditions are used to form an ordered nanocrystal/silica array material as a thin film.

  3. The uptake and solubility of water in quartz at elevated pressure and temperature

    NASA Astrophysics Data System (ADS)

    Gerretsen, J.; Paterson, M. S.; McLaren, A. C.

    1989-02-01

    The uptake of water in quartz at 1.5 GPa total pressure, 1173 K and high water fugacity, over times up to 24 h, has been investigated using a newly developed assembly to prevent microcracking. It is found that the uptake is small, and below the detectability of the presently used technique of infrared spectroscopy and serial sectioning. This observation reflects either a low value for the diffusivity or the solubility or a combination of both, and is in agreement with the observations of Kronenberg et al. (1986) and Rovetta et al. (1986). It brings into question the interpretation of the early experiments on water weakening by Griggs and Blacic (1964) and the recent estimates of the solubility and diffusivity by Mackwell and Paterson (1985). Rults of a combined T.E.M., light-scattering and infrared-spectroscopy investigation of ‘wet’ synthetic quartz before and after heating at 0.1, 300 and 1500 MPa total pressure and 1173 K, strongly suggest that the water in ‘wet’ quartz is mainly in the form of H2O in inclusions, consistent with the solubility being low, possibly less than 100 H/106Si. From these observations, water-containing inclusions appear to play a major role in the plasticity of quartz, while any role of water in solid solution remains to be clarified.

  4. Nanoformulation and encapsulation approaches for poorly water-soluble drug nanoparticles.

    PubMed

    Wais, Ulrike; Jackson, Alexander W; He, Tao; Zhang, Haifei

    2016-01-28

    During the last few decades the nanomedicine sector has emerged as a feasible and effective solution to the problems faced by the high percentage of poorly water-soluble drugs. Decreasing the size of such drug compounds to the nanoscale can significantly change their physical properties, which lays the foundation for the use of nanomedicine for pharmaceutical applications. Various techniques have been developed to produce poorly water-soluble drug nanoparticles, mainly to address the poor water-soluble issues but also for the efficient and targeted delivery of such drugs. These techniques can be generally categorized into top-down, bottom-up and encapsulation approaches. Among them, the top-down approaches have been the main choice for industrial preparation of drug nanoparticles while other methods are actively investigated by researchers. In this review, we aim to give a comprehensive overview and latest progress of the top-down, bottom-up, and encapsulation methods for the preparation of poorly water-soluble drug nanoparticles and how solvents and additives can be selected for these methods. In addition to the more industrially applied top-down approaches, the review is focused more on bottom-up and encapsulation methods, particularly covering supercritical fluid-related methods, cryogenic techniques, and encapsulation with dendrimers and responsive block copolymers. Some of the approved and mostly used nanodrug formulations on the market are also covered to demonstrate the applications of poorly water-soluble drug nanoparticles. This review is complete with perspectives on the development and challenges of fabrication techniques for more effective nanomedicine. PMID:26731460

  5. Nanoformulation and encapsulation approaches for poorly water-soluble drug nanoparticles

    NASA Astrophysics Data System (ADS)

    Wais, Ulrike; Jackson, Alexander W.; He, Tao; Zhang, Haifei

    2016-01-01

    During the last few decades the nanomedicine sector has emerged as a feasible and effective solution to the problems faced by the high percentage of poorly water-soluble drugs. Decreasing the size of such drug compounds to the nanoscale can significantly change their physical properties, which lays the foundation for the use of nanomedicine for pharmaceutical applications. Various techniques have been developed to produce poorly water-soluble drug nanoparticles, mainly to address the poor water-soluble issues but also for the efficient and targeted delivery of such drugs. These techniques can be generally categorized into top-down, bottom-up and encapsulation approaches. Among them, the top-down approaches have been the main choice for industrial preparation of drug nanoparticles while other methods are actively investigated by researchers. In this review, we aim to give a comprehensive overview and latest progress of the top-down, bottom-up, and encapsulation methods for the preparation of poorly water-soluble drug nanoparticles and how solvents and additives can be selected for these methods. In addition to the more industrially applied top-down approaches, the review is focused more on bottom-up and encapsulation methods, particularly covering supercritical fluid-related methods, cryogenic techniques, and encapsulation with dendrimers and responsive block copolymers. Some of the approved and mostly used nanodrug formulations on the market are also covered to demonstrate the applications of poorly water-soluble drug nanoparticles. This review is complete with perspectives on the development and challenges of fabrication techniques for more effective nanomedicine.

  6. Monosaccharides as Versatile Units for Water-Soluble Supramolecular Polymers.

    PubMed

    Leenders, Christianus M A; Jansen, Gijs; Frissen, Martijn M M; Lafleur, René P M; Voets, Ilja K; Palmans, Anja R A; Meijer, E W

    2016-03-18

    We introduce monosaccharides as versatile water-soluble units to compatibilise supramolecular polymers based on the benzene-1,3,5-tricarboxamide (BTA) moiety with water. A library of monosaccharide-based BTAs is evaluated, varying the length of the alkyl chain (hexyl, octyl, decyl and dodecyl) separating the BTA and saccharide units, as well as the saccharide units (α-glucose, β-glucose, α-mannose and α-galactose). In all cases, the monosaccharides impart excellent water compatibility. The length of the alkyl chain is the determining factor to obtain either long, one-dimensional supramolecular polymers (dodecyl spacer), small aggregates (decyl spacer) or molecularly dissolved (octyl and hexyl) BTAs in water. For the BTAs comprising a dodecyl spacer, our results suggest that a cooperative self-assembly process is operative and that the introduction of different monosaccharides does not significantly change the self- assembly behaviour. Finally, we investigate the potential of post-assembly functionalisation of the formed supramolecular polymers by taking advantage of dynamic covalent bond formation between the monosaccharides and benzoxaboroles. We observe that the supramolecular polymers readily react with a fluorescent benzoxaborole derivative permitting imaging of these dynamic complexes by confocal fluorescence microscopy. PMID:26890574

  7. Microautoradiography of Water-Soluble Compounds in Plant Tissue after Freeze-Drying and Pressure Infiltration with Epoxy Resin

    PubMed Central

    Vogelmann, Thomas C.; Dickson, Richard E.

    1982-01-01

    It is difficult to retain and localize radioactive, water-soluble compounds within plant cells. Existing techniques retain water-soluble compounds with varying rates of efficiency and are limited to processing only a few samples at one time. We developed a modified pressure infiltration technique for the preparation of microautoradiographs of 14C-labeled, water-soluble compounds in plant tissue. Samples from cottonwood (Populus deltoides Bartr. ex Marsh.) labeled with 14C were excised, quick frozen in liquid N2, freeze-dried at −50°C, and pressure-infiltrated with epoxy resin without intermediate solvents or prolonged incubation times. The technique facilitates the mass processing of samples for microautoradiography, gives good cellular retention of labeled water-soluble compounds, and is highly reproducible. Images Fig. 2 PMID:16662542

  8. Graphene frameworks synthetized with Na2CO3 as a renewable water-soluble substrate and their high rate capability for supercapacitors

    NASA Astrophysics Data System (ADS)

    Cui, Huijuan; Zheng, Jianfeng; Zhu, Yanyan; Wang, Zhijian; Jia, Suping; Zhu, Zhenping

    2015-10-01

    Substrates are normally required in the chemical synthesis of graphene to enhance its formation. However, removing substrates in the post purification stage is difficult, during which harsh reagents are used and the substrates are usually consumed undesirably. In this paper, we report that universal sodium carbonate (Na2CO3) particles can effectively promote the construction of well-structured graphene frameworks based on a quick thermal decomposition of fumaric acids. Notably, the Na2CO3 particles are easily separated from graphene through a simple and green method, namely, washing with water at room temperature. Together with the reused characteristic of the recovered Na2CO3 particles, this approach is undoubtedly beneficial to the low-cost and clean synthesis of graphene. Benefiting from the framework structure, the as-synthesized graphene exhibits excellent performance in the supercapacitor. The specific capacitance of the GFs-modified electrode was calculated to be 242 F g-1 at 0.5 A g-1, which was almost twice that of the RGO-modified electrode (134 F g-1). More importantly, the GFs-modified electrode maintained 92.6% retention of its initial specific capacitance (from current density of 0.5 to 16 A g-1), which was much higher than that of 2D graphene-modified electrode.

  9. Biodegradable fibre scaffolds incorporating water-soluble drugs and proteins.

    PubMed

    Ma, J; Meng, J; Simonet, M; Stingelin, N; Peijs, T; Sukhorukov, G B

    2015-07-01

    A new type of biodegradable drug-loaded fibre scaffold has been successfully produced for the benefit of water-soluble drugs and proteins. Model drug loaded calcium carbonate (CaCO3) microparticles incorporated into poly(lactic acid-co-glycolic acid) (PLGA) fibres were manufactured by co-precipitation of CaCO3 and the drug molecules, followed by electrospinning of a suspension of such drug-loaded microparticles in a PLGA solution. Rhodamine 6G and bovine serum albumin were used as model drugs for our release study, representing small bioactive molecules and protein, respectively. A bead and string structure of fibres was achieved. The drug release was investigated with different drug loadings and in different pH release mediums. Results showed that a slow and sustained drug release was achieved in 40 days and the CaCO3 microparticles used as the second barrier restrained the initial burst release. PMID:26155976

  10. Biological activities of water-soluble fullerene derivatives

    NASA Astrophysics Data System (ADS)

    Nakamura, S.; Mashino, T.

    2009-04-01

    Three types of water-soluble fullerene derivatives were synthesized and their biological activities were investigated. C60-dimalonic acid, an anionic fullerene derivative, showed antioxidant activity such as quenching of superoxide and relief from growth inhibition of E. coli by paraquat. C60-bis(7V,7V-dimethylpyrrolidinium iodide), a cationic fullerene derivative, has antibacterial activity and antiproliferative effect on cancer cell lines. The mechanism is suggested to be respiratory chain inhibition by reactive oxygen species produced by the cationic fullerene derivative. Proline-type fullerene derivatives showed strong inhibition activities on HIV-reverse transcriptase. The IC50 values were remarkably lower than nevirapine, a clinically used anti-HIV drug. Fullerene derivatives have a big potential for a new type of lead compound to be used as medicine.

  11. Reactivity of Metal Ions Bound to Water-Soluble Polymers

    SciTech Connect

    Sauer, N.N.; Watkins, J.G.; Lin, M.; Birnbaum, E.R.; Robison, T.W.; Smith, B.F.; Gohdes, J.W.; McDonald, J.G.

    1999-06-29

    The intent of this work is to determine the effectiveness of catalysts covalently bound to polymers and to understand the consequences of supporting the catalysts on catalyst efficiency and selectivity. Rhodium phosphine complexes with functional groups for coupling to polymers were prepared. These catalyst precursors were characterized using standard techniques including IR, NMR, and elemental analysis. Studies on the modified catalysts showed that they were still active hydrogenation catalysts. However, tethering of the catalysts to polyamines gave systems with low hydrogenation activity. Analogous biphasic systems were also explored. Phosphine ligands with a surfactant-like structure have been synthesized and used to prepare catalytically active complexes of palladium. The palladium complexes were utilized in Heck-type coupling reactions (e.g. coupling of iodobenzene and ethyl acrylate to produce ethyl cinnamate) under vigorously stirred biphasic reaction conditions, and were found to offer superior performance over a standard water-soluble palladium catalyst under analogous conditions.

  12. Utilization of water/alcohol-soluble polyelectrolyte as an electron injection layer for fabrication of high-efficiency multilayer saturated red-phosphorescence polymer light-emitting diodes by solution processing

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Liang, Bo; Huang, Fei; Peng, Junbiao; Cao, Yong

    2006-10-01

    Highly efficient multilayer red polymer light-emitting diodes were fabricated by solution process-ing from iridium complex, bis(1-(3-(9,9-dimethyl-fluorene-2-yl)phenyl)isoquinoline-C2,N ') iridium(III)acetylacetonate, doped into polyfluorene as a host and with a water/alcohol-soluble polymer, poly[(9,9-bis(3'-((N ,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)-4,7-(2,1,3-benzoselenadiazole)]dibromide (PFN) as electron injection layer. The device with the structure ITO /PEDOT-PSS(50nm)/PVK(40nm)/PFO:PBD:Ir(DMFPQ)2acac(2%,75nm)/PFN(20nm)/Ba(4.5nm)/Al(150nm) showed an external quantum efficiency of 18.0% and luminance efficiency of 9.8Cd/A at a current density of 1.1mA/cm2, a peak emission at λmax=636nm, and Commission International de I'Eclairage coordinates of (0.665, 0.319). The efficiency remained as high as QE =11.1%, and LE =6.0cd/A, at a current density of 100mA/cm2, and a luminance of 6140cd/m2.

  13. High resolution FT-ICR mass spectral analysis of bio-oil and residual water soluble organics produced by hydrothermal liquefaction of the marine microalga Nannochloropsis salina

    SciTech Connect

    Sudasinghe, Nilusha; Dungan, Barry; Lammers, Peter; Albrecht, Karl O.; Elliott, Douglas C.; Hallen, Richard T.; Schaub, Tanner

    2014-03-01

    We report a detailed compositional characterization of a bio-crude oil and aqueous by-product from hydrothermal liquefaction of Nannochloropsis salina by direct infusion Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) in both positive- and negative-ionization modes. The FT-ICR MS instrumentation approach facilitates direct assignment of elemental composition to >7000 resolved mass spectral peaks and three-dimensional mass spectral images for individual heteroatom classes highlight compositional diversity of the two samples and provide a baseline description of these materials. Aromatic nitrogen compounds and free fatty acids are predominant species observed in both the bio-oil and aqueous fraction. Residual organic compounds present in the aqueous fraction show distributions that are slightly lower in both molecular ring and/or double bond value and carbon number relative to those found in the bio-oil, albeit with a high degree of commonality between the two compositions.

  14. Analysis of the monosaccharide composition of water-soluble polysaccharides from Sargassum fusiforme by high performance liquid chromatography/electrospray ionisation mass spectrometry.

    PubMed

    Wu, Xiaodan; Jiang, Wei; Lu, Jiajia; Yu, Ying; Wu, Bin

    2014-02-15

    Sargassum fusiforme (hijiki) is the well-known edible algae, whose polysaccharides have been proved to possess interesting bioactivities like antitumor, antioxidant, antimicrobial and immunomodulatory activities. A facile and sensitive method based on high-performance liquid chromatography method of pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) coupled with electrospray ionisation mass spectrometry (HPLC/ESI-MS) has been established for the analysis of the monosaccharide composition of polysaccharides in S. fusiforme. Monosaccharides have been converted into PMP-labelled derivatives with aqueous ammonia as a catalyst at 70 °C for 30 min. The optimisation of the pre-column derivatization process was studied. The LODs of the monosaccharides were in the range from 0.01 to 0.02 nmol. PMP-labelled mixture of monosaccharides has been well separated by a reverse-phase HPLC and detected by on-line ESI-MS method under optimised conditions. The mobile phase of elution system was chosen as acetonitrile (solvent A) and 20mM aqueous ammonium acetate (solvent B) (pH 3.0) with Zorbax XDB-C18 column at 30 °C for the separation of the monosaccharide derivatives. Identification of the monosaccharides composition was carried out by analysis with mass spectral behaviour and chromatography characteristics of 1-phenyl-3-methyl-5-pyrazolone (PMP) labelled monosaccharides. All PMP-labelled derivatives display high chemical stabilities, whose regular MS fragmentation is specific for reducing labelled sugars. The result showed that the S. fusiforme polysaccharide consisted of mannose, glucose, galactose, xylose, fucose and glucuronic acid or galacturonic acid, or both uronic acids. PMID:24128572

  15. Determination of water-soluble forms of oxalic and formic acids in soils by ion chromatography

    NASA Astrophysics Data System (ADS)

    Karicheva, E.; Guseva, N.; Kambalina, M.

    2016-03-01

    Carboxylic acids (CA) play an important role in the chemical composition origin of soils and migration of elements. The content of these acids and their salts is one of the important characteristics for agrochemical, ecological, ameliorative and hygienic assessment of soils. The aim of the article is to determine water-soluble forms of same carboxylic acids — (oxalic and formic acids) in soils by ion chromatography with gradient elution. For the separation and determination of water-soluble carboxylic acids we used reagent-free gradient elution ion-exchange chromatography ICS-2000 (Dionex, USA), the model solutions of oxalate and formate ions, and leachates from soils of the Kola Peninsula. The optimal gradient program was established for separation and detection of oxalate and formate ions in water solutions by ion chromatography. A stability indicating method was developed for the simultaneous determination of water-soluble organic acids in soils. The method has shown high detection limits such as 0.03 mg/L for oxalate ion and 0.02 mg/L for formate ion. High signal reproducibility was achieved in wide range of intensities which correspond to the following ion concentrations: from 0.04 mg/g to 10 mg/L (formate), from 0.1 mg/g to 25 mg/L (oxalate). The concentration of formate and oxalate ions in soil samples is from 0.04 to 0.9 mg/L and 0.45 to 17 mg/L respectively.

  16. Effects of heat and high-pressure treatments on the solubility and immunoreactivity of almond proteins.

    PubMed

    Zhang, Yan; Zhang, Jieqiong; Sheng, Wei; Wang, Shuo; Fu, Tong-Jen

    2016-05-15

    The effects of dry and moist heat, autoclave sterilization and high-pressure treatment on the biochemical characteristics and immunological properties of almond proteins were investigated. Changes in the solubility and immunoreactivity of almond proteins extracted from treated almond flour were evaluated using a total protein assay, indirect competitive inhibition enzyme-linked immunosorbent assay (IC-ELISA), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Almond proteins were stable during dry-heat treatment at temperatures below 250°C. Dry heat at 400°C, boiling, autoclave sterilization and high-pressure treatment in the presence of water at ⩾ 500 MPa greatly reduced the solubility and immunoreactivity of almond proteins. SDS-PAGE revealed that the protein profiles of almond flour samples treated under these conditions also changed significantly. The synergistic effects of heat, pressure and the presence of water contributed to significant changes in solubility and immunoreactivity of almond proteins. PMID:26776044

  17. Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    NASA Astrophysics Data System (ADS)

    Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

    2015-06-01

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe3O4 magnetic nanoparticles (Fe3O4-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe3O4-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe3O4-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe3O4. Transmission electron microscopy (TEM) analysis confirmed that the Fe3O4-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe3O4-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe3O4-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe3O4-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature TB of Fe3O4-AOS-MN capped with double-layered AOS is 170 K.

  18. Water-soluble polymers for recovery of metal ions from aqueous streams

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.

    1998-01-01

    A process of selectively separating a target metal contained in an aqueous solution by contacting the aqueous solution containing a target metal with an aqueous solution including a water-soluble polymer capable of binding with the target metal for sufficient time whereby a water-soluble polymer-target metal complex is formed, and, separating the solution including the water-soluble polymer-target metal complex from the solution is disclosed.

  19. Development of self-nanoemulsifying drug delivery systems for the enhancement of solubility and oral bioavailability of fenofibrate, a poorly water-soluble drug

    PubMed Central

    Mohsin, Kazi; Alamri, Rayan; Ahmad, Ajaz; Raish, Mohammad; Alanazi, Fars K; Hussain, Muhammad Delwar

    2016-01-01

    Background Self-nanoemulsifying drug delivery systems (SNEDDS) have become a popular formulation option as nanocarriers for poorly water-soluble drugs. The objective of this study was to investigate the factor that can influence the design of successful lipid formulation classification system (LFCS) Type III SNEDDS formulation and improve the oral bioavailability (BA) of fenofibrate. Materials and methods LFCS Type III SNEDDS were designed using various oils, water-soluble surfactants, and/or cosolvents (in considering the polarity of the lipids) for the model anticholesterol drug, fenofibrate. The developed SNEDDS were assessed visually and by measurement of the droplet size. Equilibrium solubility of fenofibrate in the SNEDDS was conducted to find out the maximum drug loading. Dynamic dispersion studies were carried out (1/100 dilution) in water to investigate how much drug stays in solution after aqueous dispersion of the formulation. The BA of SNEDDS formulation was evaluated in the rat. Results The results from the characterization and solubility studies showed that formulations containing mixed glycerides were highly efficient SNEDDS as they had higher solubility of the drug and produced nanosized droplets. The dispersion studies confirmed that SNEDDS (containing polar mixed glycerides) can retain >98% drug in solution for >24 hours in aqueous media. The in vivo pharmacokinetics parameters of SNEDDS formulation in comparison with pure drug showed significant increase in Cmax and AUC0–t, ~78% and 67%, respectively. The oral BA of fenofibrate from SNEDDS in rats was ~1.7-fold enhanced as compared with the BA from pure drug. Conclusion Fenofibrate-loaded LFCS Type III SNEDDS formulations could be a potential oral pharmaceutical product for administering the poorly water-soluble drug, fenofibrate, with an enhanced oral BA. PMID:27366063

  20. Water-soluble ruthenium complexes bearing activity against protozoan parasites.

    PubMed

    Sarniguet, Cynthia; Toloza, Jeannette; Cipriani, Micaella; Lapier, Michel; Vieites, Marisol; Toledano-Magaña, Yanis; García-Ramos, Juan Carlos; Ruiz-Azuara, Lena; Moreno, Virtudes; Maya, Juan Diego; Azar, Claudio Olea; Gambino, Dinorah; Otero, Lucía

    2014-06-01

    Parasitic illnesses are major causes of human disease and misery worldwide. Among them, both amebiasis and Chagas disease, caused by the protozoan parasites, Entamoeba histolytica and Trypanosoma cruzi, are responsible for thousands of annual deaths. The lack of safe and effective chemotherapy and/or the appearance of current drug resistance make the development of novel pharmacological tools for their treatment relevant. In this sense, within the framework of the medicinal inorganic chemistry, metal-based drugs appear to be a good alternative to find a pharmacological answer to parasitic diseases. In this work, novel ruthenium complexes [RuCl2(HL)(HPTA)2]Cl2 with HL=bioactive 5-nitrofuryl containing thiosemicarbazones and PTA=1,3,5-triaza-7-phosphaadamantane have been synthesized and fully characterized. PTA was included as co-ligand in order to modulate complexes aqueous solubility. In fact, obtained complexes were water soluble. Their activity against T. cruzi and E. histolytica was evaluated in vitro. [RuCl2(HL4)(HPTA)2]Cl2 complex, with HL4=N-phenyl-5-nitrofuryl-thiosemicarbazone, was the most active compound against both parasites. In particular, it showed an excellent activity against E. histolytica (half maximal inhibitory concentration (IC50)=5.2 μM), even higher than that of the reference drug metronidazole. In addition, this complex turns out to be selective for E. histolytica (selectivity index (SI)>38). The potential mechanism of antiparasitic action of the obtained ruthenium complexes could involve oxidative stress for both parasites. Additionally, complexes could interact with DNA as second potential target by an intercalative-like mode. Obtained results could be considered a contribution in the search for metal compounds that could be active against multiple parasites. PMID:24740394

  1. Influence of water treatment residuals on phosphorus solubility and leaching.

    PubMed

    Elliott, H A; O'Connor, G A; Lu, P; Brinton, S

    2002-01-01

    Laboratory and greenhouse studies compared the ability of water treatment residuals (WTRs) to alter P solubility and leaching in Immokalee sandy soil (sandy, siliceous, hyperthermic Arenic Alaquod) amended with biosolids and triple superphosphate (TSP). Aluminum sulfate (Al-WTR) and ferric sulfate (Fe-WTR) coagulation residuals, a lime softening residual (Ca-WTR) produced during hardness removal, and pure hematite were examined. In equilibration studies, the ability to reduce soluble P followed the order Al-WTR > Ca-WTR = Fe-WTR > hematite. Differences in the P-fixing capacity of the sesquioxide-dominated materials (Al-WTR, Fe-WTR, hematite) were attributed to their varying reactive Fe- and Al-hydrous oxide contents as measured by oxalate extraction. Leachate P was monitored from greenhouse columns where bahiagrass (Paspalum notatum Flugge) was grown on Immokalee soil amended with biosolids or TSP at an equivalent rate of 224 kg P ha(-1) and WTRs at 2.5% (56 Mg ha(-1)). In the absence of WTRs, 21% of TSP and 11% of Largo cake biosolids total phosphorus (PT) leached over 4 mo. With co-applied WTRs, losses from TSP columns were reduced to 3.5% (Fe-WTR), 2.5% (Ca-WTR), and <1% (Al-WTR) of applied P. For the Largo biosolids treatments all WTRs retarded downward P flux such that leachate P was not statistically different than for control (soil only) columns. The phosphorus saturation index (PSI = [Pox]/ [Al(ox) + Fe(ox)], where Pox, Al, and Fe(ox) are oxalate-extractable P, Al, and Fe, respectively) based on a simple oxalate extraction of the WTR and biosolids is potentially useful for determining WTR application rates for controlled reduction of P in drainage when biosolids are applied to low P-sorbing soils. PMID:12175057

  2. Water soluble quantum dot nanoclusters: energy migration in artifical materials.

    PubMed

    Oh, Megan H J; Gentleman, Darcy J; Scholes, Gregory D

    2006-11-21

    Energy migration in self-assembled, water soluble, quantum dot (QD) nanoclusters is reported. These spherical nanoclusters are composed of CdSe QDs bound together by pepsin, a digestive enzyme found in mammals. A structural model for the clusters is suggested, based on scanning transmission electron microscopy, as well as dynamic light scattering and small angle X-ray scattering. Cluster sizes range from 100 to 400 nm in diameter and show a close-packed interior structure. Optical characterization of the absorption and emission spectra of the clusters is reported, finding photoluminescence quantum yields of up to approximately 60% in water for clusters made from core-shell CdSe-ZnS QDs. Clusters prepared from two different size populations of CdSe QD samples (3 and 4 nm in diameter) demonstrate energy migration and trapping. Resonance energy transfer (RET), from small to large dots within the QD-pepsin cluster, is observed by monitoring the quenching of the small donor dot fluorescence along with enhancement of the large acceptor dot fluorescence. PMID:17091158

  3. Study on Mixed Solvency Concept in Formulation Development of Aqueous Injection of Poorly Water Soluble Drug

    PubMed Central

    Solanki, Shailendra Singh; Soni, Love Kumar; Maheshwari, Rajesh Kumar

    2013-01-01

    In the present investigation, mixed-solvency approach has been applied for the enhancement of aqueous solubility of a poorly water- soluble drug, zaltoprofen (selected as a model drug), by making blends (keeping total concentrations 40% w/v, constant) of selected water-soluble substances from among the hydrotropes (urea, sodium benzoate, sodium citrate, nicotinamide); water-soluble solids (PEG-4000, PEG-6000); and co-solvents (propylene glycol, glycerine, PEG-200, PEG-400, PEG-600). Aqueous solubility of drug in case of selected blends (12 blends) ranged from 9.091 ± 0.011 mg/ml–43.055 ± 0.14 mg/ml (as compared to the solubility in distilled water 0.072 ± 0.012 mg/ml). The enhancement in the solubility of drug in a mixed solvent containing 10% sodium citrate, 5% sodium benzoate and 25 % S cosolvent (25% S cosolvent contains PEG200, PEG 400, PEG600, Glycerine and Propylene glycol) was more than 600 fold. This proved a synergistic enhancement in solubility of a poorly water-soluble drug due to mixed cosolvent effect. Each solubilized product was characterized by ultraviolet and infrared techniques. Various properties of solution such as pH, viscosity, specific gravity and surface tension were studied. The developed formulation was studied for physical and chemical stability. This mixed solvency shall prove definitely a boon for pharmaceutical industries for the development of dosage form of poorly water soluble drugs. PMID:26555989

  4. Physico-chemical qualification of a universal portable sampler for aerosols and water-soluble gases

    NASA Astrophysics Data System (ADS)

    Roux, Jean-Maxime; Sarda-Estève, Roland

    2015-10-01

    Developing a universal portable air sampler based on electrostatic precipitation. The challenge is to collect micro and nanoparticles, microorganisms as well as toxic molecules with a portable device. Electrostatic precipitation is an efficient and gentle method to collect airborne microorganisms and preserve their cultivability. But the collection of toxic gases required is not possible in such a device. The collection of such gases requires a liquid into which they have to be solubilized. Two concepts are being evaluated. The first one is based on electrospray. The goal is to investigate the collection efficiency of water-soluble gases. The second concept is based on the semi-humid electrostatic precipitator. Their high collection efficiencies for particles were already demonstrated. In the present study they are both tested with water-soluble gases. Concentrations are measured in the liquid solution by Ion Chromatography and in the gas phase by Proton Transfer Reaction Mass Spectrometry.

  5. Synthesis and characterization of a hyper-branched water-soluble β-cyclodextrin polymer.

    PubMed

    Trotta, Francesco; Caldera, Fabrizio; Cavalli, Roberta; Mele, Andrea; Punta, Carlo; Melone, Lucio; Castiglione, Franca; Rossi, Barbara; Ferro, Monica; Crupi, Vincenza; Majolino, Domenico; Venuti, Valentina; Scalarone, Dominique

    2014-01-01

    A new hyper-branched water-soluble polymer was synthesized by reacting β-cyclodextrin with pyromellitic dianhydride beyond the critical conditions that allow the phenomenon of gelation to occur. The molar ratio between the monomers is a crucial parameter that rules the gelation process. Nevertheless, the concentration of monomers in the solvent phase plays a key role as well. Hyper-branched β-cyclodextrin-based polymers were obtained performing the syntheses with excess of solvent and cross-linking agent, and the conditions for critical dilution were determined experimentally. A hyper-branched polymer with very high water solubility was obtained and fully characterized both as for its chemical structure and for its capability to encapsulate substances. Fluorescein was used as probe molecule to test the complexation properties of the new material. PMID:25550720

  6. Water-soluble polymer exfoliated graphene: as catalyst support and sensor.

    PubMed

    Wang, Haibo; Xia, Baoyu; Yan, Ya; Li, Nan; Wang, Jing-Yuan; Wang, Xin

    2013-05-01

    In this paper, we obtained various water-soluble polymer functionalized graphene in dimethyl sulfoxide under ultrasonication. The atomic force microscope analysis and control experiment shows the water-soluble polymer is the crucial part to help solvent molecules separate interlayer. Such polymer/graphene exhibits high conductivity and tunable surface property, as confirmed by the selected area electron diffraction and Raman and electrochemical impedance spectroscopy. As a result, a catalyst based on polyvinyl pyrrolidone (PVP)/graphene shows better methanol oxidation performance than that based on PVP/reduced graphene oxide. By changing to another polymer, poly(4-vinylpyridine)/graphene shows a stable and reversible response to pH, and demonstrates its potential for sensor application. PMID:23574310

  7. Invisible Security Ink Based on Water-Soluble Graphitic Carbon Nitride Quantum Dots.

    PubMed

    Song, Zhiping; Lin, Tianran; Lin, Lihua; Lin, Sen; Fu, Fengfu; Wang, Xinchen; Guo, Liangqia

    2016-02-18

    Stimuli-responsive photoluminescent (PL) materials have been widely used as fluorescent ink for data security applications. However, traditional fluorescent inks are limited in maintaining the secrecy of information because the inks are usually visible by naked eyes either under ambient light or UV-light illumination. Here, we introduced metal-free water-soluble graphitic carbon nitride quantum dots (g-CNQDs) as invisible security ink for information coding, encryption, and decryption. The information written by the g-CNQDs is invisible in ambient light and UV light, but it can be readable by a fluorescence microplate reader. Moreover, the information can be encrypted and decrypted by using oxalic acid and sodium bicarbonate as encryption reagent and decryption reagent, respectively. Our findings provide new opportunities for high-level information coding and protection by using water-soluble g-CNQDs as invisible security ink. PMID:26797811

  8. Chlorin p6-Based Water-Soluble Amino Acid Derivatives as Potent Photosensitizers for Photodynamic Therapy.

    PubMed

    Meng, Zhi; Yu, Bin; Han, Guiyan; Liu, Minghui; Shan, Bin; Dong, Guoqiang; Miao, Zhenyuan; Jia, Ningyang; Tan, Zou; Li, Buhong; Zhang, Wannian; Zhu, Haiying; Sheng, Chunquan; Yao, Jianzhong

    2016-05-26

    The development of novel photosensitizer with high phototoxicity, low dark toxicity, and good water solubility is a challenging task for photodynamic therapy (PDT). A series of chlorin p6-based water-soluble amino acid conjugates were synthesized and investigated for antitumor activity. Among them, aspartylchlorin p6 dimethylester (7b) showed highest phototoxicity against melanoma cells with weakest dark toxicity, which was more phototoxic than verteporfin while with less dark toxicity. It also exhibited better in vivo PDT antitumor efficacy on mice bearing B16-F10 tumor than verteporfin. The biological assays revealed that 7b was localized in multiple subcellular organelles and could cause both cell necrosis and apoptosis after PDT in a dose-dependent manner, resulting in more effective cell destruction. As a result, 7b represents a promising photosensitizer for PDT applications because of its strong absorption in the phototherapeutic window, relatively high singlet oxygen quantum yield, highest dark toxicity/phototoxicity ratio, good water solubility, and excellent in vivo PDT antitumor efficacy. PMID:27136389

  9. Formamide: an efficient solvent to synthesize water-soluble and sub-ten-nanometer nanocrystals

    NASA Astrophysics Data System (ADS)

    Xu, Biao; Zhang, Zhicheng; Wang, Xun

    2013-05-01

    Nanocrystals have drawn lots of attention in many fields. The main-stream synthetic routes usually produced hydrophobic nanocrystals (NCs). Organometallic precursors and long-alkyl-chain ligands are adopted and for further use surface modification to render them water-soluble is needed. A direct protocol to synthesize water-soluble NCs in an environmental-friendly and convenient way is still quite deficient, especially for sub-10 nm NCs. We report here a formamide solvent-system to prepare high-quality metal, metal alloy, metal sulfide, metal selenide and ternary sulfide NCs in the sub-10 nm region, with simple inorganic metal salts as precursors. The as-obtained NCs exhibit monodisperse size and can be dispersed in aqueous solution for further applications.Nanocrystals have drawn lots of attention in many fields. The main-stream synthetic routes usually produced hydrophobic nanocrystals (NCs). Organometallic precursors and long-alkyl-chain ligands are adopted and for further use surface modification to render them water-soluble is needed. A direct protocol to synthesize water-soluble NCs in an environmental-friendly and convenient way is still quite deficient, especially for sub-10 nm NCs. We report here a formamide solvent-system to prepare high-quality metal, metal alloy, metal sulfide, metal selenide and ternary sulfide NCs in the sub-10 nm region, with simple inorganic metal salts as precursors. The as-obtained NCs exhibit monodisperse size and can be dispersed in aqueous solution for further applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00643c

  10. Synthesis, Characterization and Application of Water-soluble Gold and Silver Nanoclusters

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh

    The term `nanotechnology' has emerged as a buzzword since the last few decades. It has found widespread applications across disciplines, from medicine to energy. The synthesis of gold and silver nanoclusters has found much excitement, due to their novel material properties. Seminal work by various groups, including ours, has shown that the size of these clusters can be controlled with atomic precision. This control gives access to tuning the optical and electronic properties. The majority of nanoclusters reported thus far are not water soluble, which limit their applications in biology that requires water-solubility. Going from organic to aqueous phase is by no means a simple task, as it is associated with many challenges. Their stability in the presence of oxygen, difficulty in characterization, and separation of pure nanoclusters are some of the major bottlenecks associated with the synthesis of water-soluble gold nanoclusters. Water-soluble gold nanoclusters hold great potential in biological labeling, bio-catalysis and nano-bioconjugates. To overcome this problem, a new ligand with structural rigidity is needed. After considering various possibilities, we chose Captopril as a candidate ligand. In my thesis research, the synthesis of Au25 nanocluster capped with captopril has been reported. Captopril-protected Au25 nanocluster showed significantly higher thermal stability and enhanced chiroptical properties than the Glutathione-capped cluster, which confirms our initial rationale, that the ligand is critical in protecting the nanocluster. The optical absorption properties of these Au25 nanoclusters are studied and compared to the plasmonic nanoparticles. The high thermal stability and solubility of Au25 cluster capped with Captopril motivated us to explore this ligand for the synthesis of other gold clusters. Captopril is a chiral molecule with two chiral centers. The chiral ligand can induce chirality to the overall cluster, even if the core is achiral

  11. [Emission Characteristics of Water-Soluble Ions in Fumes of Coal Fired Boilers in Beijing].

    PubMed

    Hu, Yue-qi; Ma, Zhao-hui; Feng, Ya-jun; Wang, Chen; Chen, Yuan-yuan; He, Ming

    2015-06-01

    Selecting coal fired boilers with typical flue gas desulfurization and dust extraction systems in Beijing as the study objects, the issues and characteristics of the water-soluble ions in fumes of coal fired boilers and theirs influence factors were analyzed and evaluated. The maximum mass concentration of total water-soluble ions in fumes of coal fired boilers in Beijing was 51.240 mg x m(-3) in the benchmark fume oxygen content, the minimum was 7.186 mg x m(-3), and the issues of the water-soluble ions were uncorrelated with the fume moisture content. SO4(2-) was the primary characteristic water-soluble ion for desulfurization reaction, and the rate of contribution of SO4(2-) in total water-soluble ions ranged from 63.8% to 81.0%. F- was another characteristic water-soluble ion in fumes of thermal power plant, and the rate of contribution of F- in total water-soluble ions ranged from 22.2% to 32.5%. The fume purification technologies significantly influenced the issues and the emission characteristics of water-soluble ions in fumes of coal fired boilers. Na+ was a characteristic water-soluble ion for the desulfurizer NaOH, NH4+ and NO3+ were characteristic for the desulfurizer NH4HCO3, and Mg2+ was characteristic for the desulfurizer MgO, but the Ca2+ emission was not increased by addition of the desulfurizer CaO or CaCO3 The concentrations of NH4+ and NO3- in fumes of thermal power plant were lower than those in fumes of industrial or heating coal fired boilers. The form of water-soluble ions was significantly correlated with fume temperature. The most water-soluble ions were in superfine state at higher fume temperature and were not easily captured by the filter membrane. PMID:26387296

  12. Simultaneous Rapid Determination of the Solubility and Diffusion Coefficients of a Poorly Water-Soluble Drug Based on a Novel UV Imaging System.

    PubMed

    Lu, Yan; Li, Mingzhong

    2016-01-01

    The solubility and diffusion coefficient are two of the most important physicochemical properties of a drug compound. In practice, both have been measured separately, which is time consuming. This work utilizes a novel technique of UV imaging to determine the solubility and diffusion coefficients of poorly water-soluble drugs simultaneously. A 2-step optimal method is proposed to determine the solubility and diffusion coefficients of a poorly water-soluble pharmaceutical substance based on the Fick's second law of diffusion and UV imaging measurements. Experimental results demonstrate that the proposed method can be used to determine the solubility and diffusion coefficients of a drug with reasonable accuracy, indicating that UV imaging may provide a new opportunity to accurately measure the solubility and diffusion coefficients of a poorly water-soluble drug simultaneously and rapidly. PMID:26852848

  13. Enhancement of the water solubility of flavone glycosides by disruption of molecular planarity of the aglycone moiety.

    PubMed

    Lewin, Guy; Maciuk, Alexandre; Moncomble, Aurélien; Cornard, Jean-Paul

    2013-01-25

    Enhancement of the water solubility by disruption of molecular planarity has recently been reviewed as a feasible approach in small-molecule drug discovery programs. We applied this strategy to some natural flavone glycosides, especially diosmin, a highly insoluble citroflavonoid prescribed as an oral phlebotropic drug. Disruption of planarity at the aglycone moiety by 3-bromination or chlorination afforded 3-bromo- and 3-chlorodiosmin, displaying a dramatic solubility increase compared with the parent compound. PMID:23249276

  14. Solubility of methane in N-methylpyrrolidone in the presence of water

    SciTech Connect

    Zubov, S.B.; Sokolina, L.F.; Afanas'ev, Yu.M.

    1987-08-20

    Various organic solvents, among which N-methylpyrrolidone possesses high absorption capacity, are widely used for the purification of gases from sulfur compounds and carbon dioxide. The gas sent for purification usually contains water vapors, which, dissolving in the absorbent, change its absorption capacity. In this work the authors investigated the equilibrium solubility of methane in N-methylpyrrolidone with various water contents. These data are necessary for calculating the amount and composition of the gases for ventilating and regenerating a saturated absorbent. The work is part of an investigation conducted to evaluate physical solvents for the purification of natural gas.

  15. The effect of water on the mechanical properties of soluble and insoluble ceramic cements.

    PubMed

    Koh, Ilsoo; López, Alejandro; Pinar, Ana B; Helgason, Benedikt; Ferguson, Stephen J

    2015-11-01

    Ceramic cements are good candidates for the stabilization of fractured bone due to their potential ease of application and biological advantages. New formulations of ceramic cements have been tested for their mechanical properties, including strength, stiffness, toughness and durability. The changes in the mechanical properties of a soluble cement (calcium sulfate) upon water-saturation (saturation) was reported in our previous study, highlighting the need to test ceramic cements using saturated samples. It is not clear if the changes in the mechanical properties of ceramic cements are exclusive to soluble cements. Therefore the aim of the present study was to observe the changes in the mechanical properties of soluble and insoluble ceramic cements upon saturation. A cement with high solubility (calcium sulfate dihydrate, CSD) and a cement with low solubility (dicalcium phosphate dihydrate, DCPD) were tested. Three-point bending tests were performed on four different groups of: saturated CSD, non-saturated CSD, saturated DCPD, and non-saturated DCPD samples. X-ray diffraction analysis and scanning electron microscopy were also performed on a sample from each group. Flexural strength, effective flexural modulus and flexural strain at maximum stress, lattice volume, and crystal sizes and shape were compared, independently, between saturated and non-saturated groups of CSD and DCPD. Although material dissolution did not occur in all cases, all calculated mechanical properties decreased significantly in both CSD and DCPD upon saturation. The results indicate that the reductions in the mechanical properties of saturated ceramic cements are not dependent on the solubility of a ceramic cement. The outcome raised the importance of testing any implantable ceramic cements in saturated condition to estimate its in vivo mechanical properties. PMID:26210548

  16. Partitioning of semi-soluble organic compounds between the water phase and oil droplets in produced water.

    PubMed

    Faksness, Liv-Guri; Grini, Per Gerhard; Daling, Per S

    2004-04-01

    When selecting produced water treatment technologies, one should focus on reducing the major contributors to the total environmental impact. These are dispersed oil and semi-soluble hydrocarbons, alkylated phenols, and added chemicals. Experiments with produced water have been performed offshore on the Statoil operated platforms Gullfaks C and Statfjord B. These experiments were designed to find how much of the environmentally relevant compounds were dissolved in the water phase and not associated to the dispersed oil in the produced water. Results show that the distribution between the dispersed oil and the water phase varies highly for the different components groups. For example the concentration of PAHs and the C6-C9 alkylated phenols is strongly correlated to the content of dispersed oil. Therefore, the technologies enhancing the removal of dispersed oil have a higher potential for reducing the environmental impact of the produced water than previously considered. PMID:15041429

  17. [Functionally-relevant conformational dynamics of water-soluble proteins].

    PubMed

    Novikov, G V; Sivozhelezov, V S; Shaĭtan, K V

    2013-01-01

    A study is reported of the functional-relevant dynamics of three typical water-soluble proteins: Calmodulin, Src-tyrosine kinase as well as repressor of Trp operon. Application of the state-of-art methods of structural bioinformatics allowed to identify dynamics seen in the X-ray structures of the investigated proteins associated with their specific biological functions. In addition, Normal Mode analysis technique revealed the most probable directions of the functionally-relevant motions for all that proteins were also predicted. Importantly, overall type of the motions observed on the lowest-frequency modes was very similar to the motions seen from the analysis of the X-ray data of the examined macromolecules. Thereby it was shown that the large-scale as well as local conformational motions of the proteins might be predetermined already at the level of their tertiary structures. In particular, the determining factor might be the specific fold of the alpha-helixes. Thus functionally-relevant in vivo dynamics of the investigated proteins might be evolutionally formed by means of natural selection at the level of the spatial topology. PMID:23705506

  18. Water-soluble reaction products from ozonolysis of grasses

    SciTech Connect

    Morrison, W.H. III; Akin, D.E. )

    1990-03-01

    Ozone has been used to pretreat agricultural byproducts with the aim of increasing nutritive value for ruminants. However, not all treatments with ozone result in enhanced digestibility, suggesting reaction products from ozone treatment of plants might inhibit rumen microbial activity. Coastal Bermuda grass (Cynodon dactylon L. Pers.) (CBG) and Kentucky-31 tall fescue (Festuca arundinacea Schreb.) (K-31) were treated with ozone and the water-soluble products determined. The following acids were identified: caproic, levulinic, p-hydroxybenzoic, vinillic, azelaic, and malonic. In addition, vanillin and p-hydroxybenzaldehyde were also identified. Ozone treatment of the cell walls of CBG produced mainly p-hydroxybenzoic acid, vanillic acid, azelaic acid, p-hydroxybenzaldehyde, and vanillin. Ozone treatment of K-31 cell walls produced levulinic acid in addition to those products found from CBG cell walls. The production of vanillin and p-hydroxybenzaldehyde, which have been shown to be especially toxic to rumen microorganisms, offers an explanation for the negative affects of ozone treatment on forage.

  19. Stability of water-soluble carbodiimides in aqueous solution.

    PubMed

    Gilles, M A; Hudson, A Q; Borders, C L

    1990-02-01

    A dimethylbarbituric acid reagent has been used to follow the kinetics of loss of two water-soluble carbodiimides, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and the structurally related 1-ethyl-3-(4-azonia-4,4-dimethylpentyl) carbodiimide (EAC), in aqueous solution as a function of pH and added chemical reagents. In 50 mM 2-(N-morpholino)ethanesulfonic acid at 25 degrees C, EDC has t1/2 values of 37, 20, and 3.9 h at pH 7.0, 6.0, and 5.0, respectively, while the corresponding values for EAC are 12, 2.9, and 0.32 h. Iodide, bromide, or chloride, at 0.1 M, has very little or no effect on carbodiimide stability. However, 0.1 M glycine methyl ester or 0.1 M ethylenediamine causes a significant increase in the rate of loss of EAC and EDC, while the presence of 0.1 M phosphate, 0.1 M hydroxylamine, or 0.01 M ATP decreases the half-lives to less than or equal to 0.4 h at all pH values. PMID:2158246

  20. Solubility prediction of carbon dioxide in water by an iterative equation of state/excess Gibbs energy model

    NASA Astrophysics Data System (ADS)

    Suleman, H.; Maulud, A. S.; Man, Z.

    2016-06-01

    The solubility of carbon dioxide in water has been predicted extensively by various models, owing to their vast applications in process industry. Henry's law has been widely utilized for solubility prediction with good results at low pressure. However, the law shows large deviations at high pressure, even when adjusted to pressure correction and improved conditions. Contrarily, equations of state/excess Gibbs energy models are a promising addition to thermodynamic models for prediction at high pressure non-ideal equilibria. These models can efficiently predict solubilities at high pressures, even when the experimental solubilities are not corroborated. Hence, these models work iteratively, utilizing the mathematical redundancy of local composition excess Gibbs energy models. In this study, an iterative form of Linear Combination of Vidal and Michelsen (LCVM) mixing rule has been used for prediction of carbon dioxide solubility in water, in conjunction with UNIFAC and translated modified Peng- Robinson equation of state. The proposed model, termed iterative LCVM (i-LCVM), predicts carbon dioxide solubility in water for a wide range of temperature (273 to 453 K) and pressure (101.3 to 7380 kPa). The i-LCVM shows good agreement with experimental values and predicts better than Henry's law (53% improvement).

  1. Preparation of biomaterials on the basis of a water-soluble cellulose acetate

    NASA Astrophysics Data System (ADS)

    Akmalova, G. Yu.; Gulyamova, N. S.; Zainutdinov, U. N.; Rakhmanberdiev, G. R.; Negmatova, K. S.; Negmatova, M. I.

    2012-07-01

    Biomaterials were obtained on the basis of water-soluble cellulose acetate and diterpenoids group of plants Lagohulusa intoxicating having hemostatic properties. It is established that these biomaterials on the basis of water-soluble cellulose acetate and lagohilina (or lagohirzina) had increased hemostatic activity and reduce parenchymal hemorrhage 5-6 times compared to control.

  2. Water-soluble fullerene materials for bioapplications: photoinduced reactive oxygen species generation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The photoinduced reactive oxygen species (ROS) generation from several water-soluble fullerenes was examined. Macromolecular or small molecular water-soluble fullerene complexes/derivatives were prepared and their 1O2 and O2•- generation abilities were evaluated by EPR spin-trapping methods. As a r...

  3. [Analysis and identification of water soluble components of water buffalo horn].

    PubMed

    Liu, Rui; Duan, Jin-ao; Wu, Hao; Liu, Pei; Shang, Er-xin; Qian, Da-wei

    2015-05-01

    This study is to analyze and identify the water soluble components of water buffalo horn (Bubali Cornu, WBH), and also establish a method for investigating these components. Shotgun proteomic analysis identified proteins in WBH aqueous extraction: keratin, collagen, desmoglein, etc. Ultrafiltration and LC-MS/MS were used to separate and identify the peptides in WBH aqueous extract, as a result, identified peptides were mainly derived from nonspecific degradation products of keratin and collagen, which including C-terminal peptides and non C-terminal peptides. Hypoxanthine, uridine, guanosine, and adenosine were identified by comparing with the standards. The strategy in present study could be used in analyzing water soluble components of animal horn derived TCM. It provides a reference for investigation of the material basis of animal horn derived TCM. PMID:26234143

  4. Solubility of Naproxen in Polyethylene Glycol 200 + Water Mixtures at Various Temperatures

    PubMed Central

    Panahi-Azar, Vahid; Soltanpour, Shahla; Martinez, Fleming; Jouyban, Abolghasem

    2015-01-01

    The solubility of naproxen in binary mixtures of polyethylene glycol 200 (PEG 200) + water at the temperature range from 298.0 K to 318.0 K were reported. The combinations of Jouyban-Acree model + van’t Hoff and Jouyban-Acree model + partial solubility parameters were used to predict the solubility of naproxen in PEG 200 + water mixtures at different temperatures. Combination of Jouyban-Acree model with van’t Hoff equation can be used to predict solubility in PEG 200 + water with only four solubility data in mono-solvents. The obtained solubility calculation errors vary from ~ 17 % up to 35 % depend on the number of required input data. Non-linear enthalpy-entropy compensation was found for naproxen in the investigated solvent system and the Jouyban−Acree model provides reasonably accurate mathematical descriptions of the thermodynamic data of naproxen in the investigated binary solvent systems. PMID:26664370

  5. Development of micellar reactive oxygen species assay for photosafety evaluation of poorly water-soluble chemicals.

    PubMed

    Seto, Yoshiki; Kato, Masashi; Yamada, Shizuo; Onoue, Satomi

    2013-09-01

    A reactive oxygen species (ROS) assay was previously developed for photosafety assessment; however, the phototoxic potential of some chemicals cannot be evaluated because of their limited aqueous solubility. The present study was undertaken to develop a new micellar ROS (mROS) assay system for poorly water-soluble chemicals using a micellar solution of 0.5% (v/v) Tween 20 for solubility enhancement. In repeated mROS assay, intra- and inter-day precisions (coefficient of variation) were found to be below 11%, and the Z'-factors for singlet oxygen and superoxide suggested a large separation band between positive and negative standards. The ROS and mROS assays were applied to 65 phototoxins and 18 non-phototoxic compounds for comparative purposes. Of all 83 chemicals, 25 were unevaluable in the ROS assay due to poor solubility, but only 2 were in the mROS assay. Upon mROS assay on these model chemicals, the individual specificity was 76.5%, and the positive and negative predictivities were found to be 93.9% and 86.7%, respectively. The mROS assay provided 2 false negative predictions, although negative predictivity for the ROS assay was found to be 100%. Considering the pros and cons of these assays, strategic combined use of the ROS and mROS assays might be efficacious for reliable photosafety assessment with high applicability and predictivity. PMID:23727251

  6. Photochemical, electrochemical, and photoelectrochemical water oxidation catalyzed by water-soluble mononuclear ruthenium complexes.

    PubMed

    Li, Ting-Ting; Zhao, Wei-Liang; Chen, Yong; Li, Fu-Min; Wang, Chuan-Jun; Tian, Yong-Hua; Fu, Wen-Fu

    2014-10-20

    Two mononuclear ruthenium complexes [Ru(H2tcbp)(isoq)2] (1) and [Ru(H2tcbp)(pic)2] (2) (H4tcbp=4,4',6,6'-tetracarboxy-2,2'-bipyridine, isoq=isoquinoline, pic=4-picoline) are synthesized and fully characterized. Two spare carboxyl groups on the 4,4'-positions are introduced to enhance the solubility of 1 and 2 in water and to simultaneously allow them to tether to the electrode surface by an ester linkage. The photochemical, electrochemical, and photoelectrochemical water oxidation performance of 1 in neutral aqueous solution is investigated. Under electrochemical conditions, water oxidation is conducted on the deposited indium-tin-oxide anode, and a turnover number higher than 15,000 per water oxidation catalyst (WOC) 1 is obtained during 10 h of electrolysis under 1.42 V vs. NHE, corresponding to a turnover frequency of 0.41 s(-1). The low overpotential (0.17 V) of electrochemical water oxidation for 1 in the homogeneous solution enables water oxidation under visible light by using [Ru(bpy)3](2+) (P1) (bpy=2,2'-bipyridine) or [Ru(bpy)2(4,4'-(COOEt)2-bpy)](2+) (P2) as a photosensitizer. In a three-component system containing 1 or 2 as a light-driven WOC, P1 or P2 as a photosensitizer, and Na2S2O8 or [CoCl(NH3)5]Cl2 as a sacrificial electron acceptor, a high turnover frequency of 0.81 s(-1) and a turnover number of up to 600 for 1 under different catalytic conditions are achieved. In a photoelectrochemical system, the WOC 1 and photosensitizer are immobilized together on the photoanode. The electrons efficiently transfer from the WOC to the photogenerated oxidizing photosensitizer, and a high photocurrent density of 85 μA cm(-2) is obtained by applying 0.3 V bias vs. NHE. PMID:25205065

  7. 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

  8. Biochemical characterization of the water-soluble squalene synthase from Methylococcus capsulatus and the functional analyses of its two DXXD(E)D motifs and the highly conserved aromatic amino acid residues.

    PubMed

    Ohtake, Kana; Saito, Naoki; Shibuya, Satoshi; Kobayashi, Wakako; Amano, Ryosuke; Hirai, Takumi; Sasaki, Shinji; Nakano, Chiaki; Hoshino, Tsutomu

    2014-12-01

    Information regarding squalene synthases (SQSs) from prokaryotes is scarce. We aimed to characterize the SQS from Methylococcus capsulatus. We studied its reaction mechanism by kinetic analysis and evaluated the structure of the substrate/inhibitor-binding sites via homology modeling. The cloned M. capsulatus SQS was expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid column chromatography. Interestingly, M. capsulatus SQS was water-soluble and did not require any detergent for its higher activity, unlike other SQSs studied previously; supplementation of any type of detergent inhibited enzyme activity. The specific activity and the kinetic values (Km and kcat ) for the substrate farnesyl diphosphate and NADPH are reported. The substrate analog farnesyl methylenediphosphonate showed potent inhibition toward the enzyme. We prepared the site-specific mutants directed at potential active-site residues (58) DXX(61) E(62) D (S1 site) and (213) DXX(216) D(217) D (S2 site), which were assumed to be involved in the binding of the substrate farnesyl diphosphate through the Mg(2+) ion. We first demonstrated that the S1 site and the two basic residues (R55 and K212) were responsible for the binding of farnesyl diphosphate. Furthermore, we examined the catalytic roles of the highly conserved aromatic residues and demonstrated that the Y164 residue abstracts the proton of cation 5, which is produced during the first half-reaction (Scheme 1), to afford presqualene diphosphate, and that the W224 residue stabilizes the intermediary cation 5 via the cation-π interaction. Furthermore, we confirm for the first time that the F32 and the Y51 residues also stabilize the carbocation intermediate(s) generated during the second half-reaction. PMID:25283713

  9. Design of multicomponent photocatalysts for hydrogen production under visible light using water-soluble titanate nanodisks.

    PubMed

    Dinh, Cao-Thang; Pham, Minh-Hao; Seo, Yongbeom; Kleitz, Freddy; Do, Trong-On

    2014-05-01

    We report the design of efficient multicomponent photocatalysts (MPs) for H2 production under visible light by using water-soluble ultrathin titanate nanodisks (TNDs) stabilized by tetraethylammonium cations (TEA(+)) as building blocks. The photocatalysts are designed in such a way to significantly enhance simultaneously the efficiency of the three main steps in the photocatalytic process i.e., light absorption, charge separation and catalytic reaction. We show, as an example, the construction of water-soluble CdS-TND-Ni MPs. The designed CdS-TND-Ni MPs, in which CdS nanoparticles and TNDs are intimately assembled to enhance the charge transfer and surface area, are controlled in composition to optimize visible light absorption. The conception of the MPs allows them to be highly dispersed in water which markedly improves the photocatalytic H2 production process. Most importantly, a Ni co-catalyst is selectively located on the surface of TNDs, enabling vectorial electron transfer from CdS to TND and to Ni, which drastically improves the charge separation. Consequently, under visible light illumination (λ ≥ 420 nm), the optimally designed CdS-TND-Ni MPs could generate H2 from ethanol-water solution with rate as high as 15.326 mmol g(-1) h(-1) during a reaction course of 15 h and with an apparent quantum yield of 24% at 420 nm. Moreover, we also demonstrate that TNDs can be combined with other single or mixed metal sulfide to form water-soluble metal sulfide-TNDs composites which could also be of great interest for photocatalytic H2 production. PMID:24664235

  10. Detection of a Water Soluble Component of the Tagish Lake Meteorite

    NASA Technical Reports Server (NTRS)

    Wirick, S.; Cody, G.; Flynn, G. J.; Jacobsen, C.; Keller, L. P.; Nakamura, K.; Zolensky, M.

    2005-01-01

    The Tagish Lake meteorite is a highly carbonaceous meteorite, with a carbon content of approximately 5% by weight [1]. Its composition and mineralogy suggest it lies between a CI1 and CM2 chondrite [2]. Part of the meteorite [the pristine fraction] was collected from the ice on Tagish Lake within one week of its landfall on Jan. 18, 2000 and this sample is considered to be the most pristine meteorite samples collected to date with regard to organic terrestrial contamination. It has been reported that only 100 ppm of the organic matter in the Tagish Lake meteorite is water soluble [3]. greater absorbance in the sigma bonding region between 290-300 eV suggesting that the soluble material contains more CH/CH2/CH3 bonds than the microtomed piece.

  11. Application of hot melt extrusion for poorly water-soluble drugs: limitations, advances and future prospects.

    PubMed

    Lu, Ming; Guo, Zhefei; Li, Yongcheng; Pang, Huishi; Lin, Ling; Liu, Xu; Pan, Xin; Wu, Chuanbin

    2014-01-01

    Hot melt extrusion (HME) is a powerful technology to enhance the solubility and bioavailability of poorly water-soluble drugs by producing amorphous solid dispersions. Although the number of articles and patents about HME increased dramatically in the past twenty years, there are very few commercial products by far. The three main obstacles limiting the commercial application of HME are summarized as thermal degradation of heat-sensitive drugs at high process temperature, recrystallization of amorphous drugs during storage and dissolving process, and difficulty to obtain products with reproducible physicochemical properties. Many efforts have been taken in recent years to understand the basic mechanism underlying these obstacles and then to overcome them. This article reviewed and summarized the limitations, recent advances, and future prospects of HME. PMID:23651401

  12. CO2-induced small water solubility in olivine and implications for properties of the shallow mantle

    NASA Astrophysics Data System (ADS)

    Yang, Xiaozhi; Liu, Dingding; Xia, Qunke

    2014-10-01

    H2O and CO2 are important components of fluids in the mantle at ∼30-150 km depth, and may affect strongly water dissolution in nominally anhydrous olivine; however, available experimental hydrogenation of olivine has been nearly exclusively carried out in coexistence with H2O (CO2-free). In this study, the effect of CO2 on water solubility in olivine has been investigated by H-annealing natural olivine under peridotite- and fluid-saturated conditions. Experiments were conducted at 1.5-5 GPa and 1100-1300 °C, with oxygen fugacity controlled by Ni-NiO and with either H2O or H2O-CO2 as buffering fluid. The olivine shows no change in composition during the experiments. The infrared spectra of the hydrated olivine are characterized by prominent OH bands from ∼3650 to 3000 cm in all the runs, at both high frequency (>3450 cm) and low frequency (<3450 cm), and the H2O solubility is ∼120-370 ppm for the olivine in coexisting with H2O, and ∼65-180 ppm for the olivine in coexisting with H2O-CO2. When CO2 is present in the buffering fluid, the H2O solubility of olivine is reduced by a factor of ∼2, due to effect on the partitioning of water between minerals and coexisting fluid, and the measured H2O solubility shows independence on fluid composition (the molar ratio of CO2 to CO2 + H2O at ∼0.2-0.5) given pressure, temperature and oxygen fugacity. Olivine equilibrated in the shallow mantle is probably dominated by OH groups in the wavenumber ∼3650-3000 cm, and the intensity of OH bands at low frequency may be higher than or comparable to those at higher frequencies. The storage capacity of water in the shallow mantle in previous estimates may have been overestimated by a factor of at least ∼4 if the observed effect of CO2 on water solubility is correct. Our results have profound influence on understanding partial melting, electrical conductivity anomalies and metasomatism in the shallow mantle.

  13. Three bisphosphonate ligands improve the water solubility of quantum dots.

    PubMed

    Abdul Ghani, Siti Fatimah; Wright, Michael; Paramo, Juan Gallo; Bottrill, Melanie; Green, Mark; Long, Nicholas; Thanou, Maya

    2014-01-01

    Synthesised Quantum Dots (QDs) require surface modification in order to improve their aqueous dispersion and biocompatibility. Here, we suggest bisphosphonate molecules as agents to modify the surface of QDs for improved water solubility and biocompatibility. QDs_TOPO (CdSe/ZnS-trioctylphosphine oxide) were synthesised following modification of the method of Bawendi et al. (J. Phys. Chem. B, 1997, 101, 9463-9475). QDs surface modification is performed using a ligand exchange reaction with structurally different bisphosphonates (BIPs). The BIPs used were ethylene diphosphonate (EDP), methylenediphosphonate (MDP) and imidodiphosphonate (IDP). After ligand exchange, the QDs were extensively purified using centrifugation, PD-10 desalting columns and mini dialysis filters. Transmission electron microscopy (TEM) and fluorescent spectroscopy have been used to characterise the size and optical properties of the QDs. Cell toxicity was investigated using MTT (tetrazolium salt) and glutathione assays and intracellular uptake was imaged using confocal laser scanning microscopy and assessed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). QDs_TOPO and QDs-capped with BIPs (QDs_BIPs) were successfully synthesised. TEM showed the size and morphology of the QDs to be 5-7 nm with spherical shape. The stabilised QDs_BIPs showed significantly improved dispersion in aqueous solutions compared to QDs_TOPO. The cytotoxicity studies showed very rapid cell death for cells treated by QDs_TOPO and a minor effect on cell viability when QDs_BIPs were applied to the cells. Both EDP- and MDP-modified QDs did not significantly increase the intracellular levels of glutathione. In contrast, IDP-modified QDs substantially increased the intracellular glutathione levels, indicating potential cadmium leakage and inability of IDP to adequately cap and stabilise the QDs. EDP- and MDP-modified QDs were taken up by IGROV-1 (ovarian cancer) cells as shown by fluorescence microscopy, however, the

  14. Luminescent, water-soluble silicon quantum dots via micro-plasma surface treatment

    NASA Astrophysics Data System (ADS)

    Wu, Jeslin J.; Kondeti, Vighneswara Siva Santosh Kumar; Bruggeman, Peter J.; Kortshagen, Uwe R.

    2016-03-01

    Silicon quantum dots (SiQDs), with their broad absorption, narrow and size-tunable emission, and potential biocompatibility are highly attractive materials in biological imaging applications. The inherent hydrophobicity and instability of hydrogen-terminated SiQDs are obstacles to their widespread implementation. In this work, we successfully produced highly luminescent, hydrophilic SiQDs with long-term stability in water using non-thermal plasma techniques. Hydrogen-terminated SiQDs were produced in a low-pressure plasma and subsequently treated in water using an atmospheric-pressure plasma jet for surface modification. Preliminary assessments of the chemical mechanism(s) involved in the creation of water-soluble SiQDs were performed using Fenton’s reaction and various plasma chemistries, suggesting both OH and O species play a key role in the oxidation of the SiQDs.

  15. Redispersible fast dissolving nanocomposite microparticles of poorly water-soluble drugs.

    PubMed

    Bhakay, Anagha; Azad, Mohammad; Bilgili, Ecevit; Dave, Rajesh

    2014-01-30

    Enhanced recovery/dissolution of two wet media-milled, poorly water-soluble drugs, Griseofulvin (GF) and Azodicarbonamide (AZD), incorporated into nanocomposite microparticles (NCMPs) via fluidized bed drying (FBD) and spray-drying (SD) was investigated. The effects of drying method, drug loading, drug aqueous solubility/wettability as well as synergistic stabilization of the milled suspensions on nanoparticle recovery/dissolution were examined. Drug nanoparticle recovery from FBD and SD produced NCMPs having high drug loadings was evaluated upon gentle redispersion via optical microscopy and laser diffraction. During wet-milling, hydroxypropyl cellulose (HPC) alone stabilized more wettable drug (AZD) nanoparticles with slight aggregation, but could not prevent aggregation of the GF nanoparticles. In contrast, well-dispersed, stable nanosuspensions of both drugs were produced when sodium dodecyl sulfate (SDS) and HPC were combined. The FBD and SD NCMPs without SDS exhibited incomplete nanoparticle recovery, causing slower dissolution for GF, but not for AZD, likely due to higher aqueous solubility/wettability of AZD. For high active loaded NCMPs (FBD ∼50 wt%, SD ∼80 wt%) of either drug, HPC-SDS together owing to their synergistic stabilization led to fast redispersibility/dissolution, corroborated via optical microscopy and particle sizing. These positive attributes can help development of smaller, high drug-loaded dosage forms having enhanced bioavailability and better patient compliance. PMID:24333905

  16. Water-soluble chelating polymers for removal of actinides from wastewater

    SciTech Connect

    Jarvinen, G.D.

    1997-10-01

    Polymer filtration is a technology under development to selectively recover valuable or regulated metal ions from process or wastewaters. The technology uses water-soluble chelating polymers that are designed to selectively bind with metal ions in aqueous solutions. The polymers have a sufficiently large molecular weight that they can be separated and concentrated using available ultrafiltration (UF) technology. The UF range is generally considered to include molecular weights from about 3000 to several million daltons and particles sizes of about 2 to 1000 nm. Water and smaller unbound components of the solution pass freely through the UF membrane. The polymers can then be reused by changing the solution conditions to release the metal ions that are recovered in concentrated form for recycle or disposal. Some of the advantages of polymer filtration relative to technology now in use are rapid binding kinetics, high selectivity, low energy and capital costs, and a small equipment footprint. Some potential commercial applications include electroplating rinse waters, photographic processing, nuclear power plant cooling water; remediation of contaminated soils and groundwater; removal of mercury contamination; and textile, paint and dye production. The purpose of this project is to evaluate this technology to remove plutonium, americium, and other regulated metal ions from various process and waste streams found in nuclear facilities. The work involves preparation of the water-soluble chelating polymers; small-scale testing of the chelating polymer systems for the required solubility, UF properties, selectivity and binding constants; followed by an engineering assessment at a larger scale to allow comparison to competing separation technologies. This project focuses on metal-ion contaminants in waste streams at the Plutonium Facility and the Waste Treatment Facility at LANL. Potential applications at other DOE facilities are also apparent.

  17. High throughput UV method for the estimation of thermodynamic solubility and the determination of the solubility in biorelevant media.

    PubMed

    Bard, Bruno; Martel, Sophie; Carrupt, Pierre-Alain

    2008-03-01

    The growing interest for high quality solubility data in the early stages of drug discovery suggested a detailed optimization of experimental conditions for a 96-well HTS UV method in order to obtain solubility values close to thermodynamic solubility measured by shake-flask method. Results have shown that solubility data obtained by the HTS approach were highly dependent on shaking intensity and incubation times due to the formation of supersaturated solutions resulting from the dilution of DMSO stock solutions in aqueous buffer. Thus, careful experimental set-up was developed to improve the quality and the reproducibility of the HTS method. Moreover, the early qualitative prediction of bioavailability and absorption of orally administered drugs require more and more biorelevant solubility values in drug discovery programs. Thus, the optimized HTS method was also adapted to measure solubility directly in FaSSIF and FeSSIF media. The versatile HTS UV approach presented in this paper provides a unique and reliable way to determine solubility in various experimental conditions. PMID:18207706

  18. Chemical Characteristics of Water-Soluble Ions in Particulate Matter in Three Metropolitan Areas in the North China Plain

    PubMed Central

    Dao, Xu; Wang, Zhen; Lv, Yibing; Teng, Enjiang; Zhang, Linlin; Wang, Chao

    2014-01-01

    PM2.5 and PM10 samples were collected simultaneously in each season in Beijing, Tianjin and Shijiazhuang to identify the characteristics of water-soluble ion compositions in the North China Plain. The water-soluble ions displayed significant seasonal variation. The dominant ions were NO3−, SO42−, NH4+ and Cl−, accounting for more than 90% and 86% to the mass of total water-soluble ions in PM2.5 and PM10, respectively. The anion/cation ratio indicated that the ion acidity of each city varied both between sites and seasonally. Over 50% of the ion species were enriched in small particles ≤1 µm in diameter. The [NO3−]/[SO42−] ratio indicated that vehicles accounted for the majority of the particulate pollution in Beijing. Shijiazhuang, a city highly reliant on coal combustion, had a higher SO42− concentration. PMID:25437210

  19. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  20. Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in Vivo

    NASA Astrophysics Data System (ADS)

    Larson, Daniel R.; Zipfel, Warren R.; Williams, Rebecca M.; Clark, Stephen W.; Bruchez, Marcel P.; Wise, Frank W.; Webb, Watt W.

    2003-05-01

    The use of semiconductor nanocrystals (quantum dots) as fluorescent labels for multiphoton microscopy enables multicolor imaging in demanding biological environments such as living tissue. We characterized water-soluble cadmium selenide-zinc sulfide quantum dots for multiphoton imaging in live animals. These fluorescent probes have two-photon action cross sections as high as 47,000 Goeppert-Mayer units, by far the largest of any label used in multiphoton microscopy. We visualized quantum dots dynamically through the skin of living mice, in capillaries hundreds of micrometers deep. We found no evidence of blinking (fluorescence intermittency) in solution on nanosecond to millisecond time scales.

  1. Water-soluble quantum dots for multiphoton fluorescence imaging in vivo.

    PubMed

    Larson, Daniel R; Zipfel, Warren R; Williams, Rebecca M; Clark, Stephen W; Bruchez, Marcel P; Wise, Frank W; Webb, Watt W

    2003-05-30

    The use of semiconductor nanocrystals (quantum dots) as fluorescent labels for multiphoton microscopy enables multicolor imaging in demanding biological environments such as living tissue. We characterized water-soluble cadmium selenide-zinc sulfide quantum dots for multiphoton imaging in live animals. These fluorescent probes have two-photon action cross sections as high as 47,000 Goeppert-Mayer units, by far the largest of any label used in multiphoton microscopy. We visualized quantum dots dynamically through the skin of living mice, in capillaries hundreds of micrometers deep. We found no evidence of blinking (fluorescence intermittency) in solution on nanosecond to millisecond time scales. PMID:12775841

  2. Early outgassing of Mars supported by differential water solubility of iodine and xenon

    NASA Technical Reports Server (NTRS)

    Musselwhite, Donald S.; Drake, Michael J.; Swindle, Timothy D.

    1991-01-01

    The Martian atmosphere has a high X-129/Xe-132 ratio compared to the Martian mantle. As Xe-129 is the daughter product of the extinct nuclide I-129, a means of fractionating iodine from xenon early in Martian history appears necessary to account for the X-129/Xe-132 ratios of its known reservoirs. A model is presented here to account for the Marian xenon data which relies on the very different solubilities of xenon and iodine in water to fractionate them after outgassing. Atmospheric xenon is lost by impact erosion during heavy bombardment, followed by release of Xe-129 produced from I-129 decay in the crust.

  3. 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

  4. Impact of biochar amendment on soil water soluble carbon in the context of extreme hydrological events.

    PubMed

    Wang, Daoyuan; Griffin, Deirdre E; Parikh, Sanjai J; Scow, Kate M

    2016-10-01

    Biochar amendments to soil have been promoted as a low cost carbon (C) sequestration strategy as well as a way to increase nutrient retention and remediate contaminants. If biochar is to become part of a long-term management strategy, it is important to consider its positive and negative impacts, and their trade-offs, on soil organic matter (SOM) and soluble C under different hydrological conditions such as prolonged drought or frequent wet-dry cycles. A 52-week incubation experiment measuring the influence of biochar on soil water soluble C under different soil moisture conditions (wet, dry, or wet-dry cycles) indicated that, in general, dry and wet-dry cycles increased water soluble C, and biochar addition further increased release of water soluble C from native SOM. Biochar amendment appeared to increase transformation of native SOM to water soluble C, based on specific ultraviolet absorption (SUVA) and C stable isotope composition; however, the increased amount of water soluble C from native SOM is less than 1% of total biochar C. The impacts of biochar on water soluble C need to be carefully considered when applying biochar to agricultural soil. PMID:27391051

  5. Explaining Ionic Liquid Water Solubility in Terms of Cation and Anion Hydrophobicity

    PubMed Central

    Ranke, Johannes; Othman, Alaa; Fan, Ping; Müller, Anja

    2009-01-01

    The water solubility of salts is ordinarily dictated by lattice energy and ion solvation. However, in the case of low melting salts also known as ionic liquids, lattice energy is immaterial and differences in hydrophobicity largely account for differences in their water solubility. In this contribution, the activity coefficients of ionic liquids in water are split into cation and anion contributions by regression against cation hydrophobicity parameters that are experimentally determined by reversed phase liquid chromatography. In this way, anion hydrophobicity parameters are derived, as well as an equation to estimate water solubilities for cation-anion combinations for which the water solubility has not been measured. Thus, a new pathway to the quantification of aqueous ion solvation is shown, making use of the relative weakness of interactions between ionic liquid ions as compared to their hydrophobicities. PMID:19399248

  6. Water solubility in aluminous orthopyroxene and the origin of Earth's asthenosphere.

    PubMed

    Mierdel, Katrin; Keppler, Hans; Smyth, Joseph R; Langenhorst, Falko

    2007-01-19

    Plate tectonics is based on the concept of rigid lithosphere plates sliding on a mechanically weak asthenosphere. Many models assume that the weakness of the asthenosphere is related to the presence of small amounts of hydrous melts. However, the mechanism that may cause melting in the asthenosphere is not well understood. We show that the asthenosphere coincides with a zone where the water solubility in mantle minerals has a pronounced minimum. The minimum is due to a sharp decrease of water solubility in aluminous orthopyroxene with depth, whereas the water solubility in olivine continuously increases with pressure. Melting in the asthenosphere may therefore be related not to volatile enrichment but to a minimum in water solubility, which causes excess water to form a hydrous silicate melt. PMID:17234945

  7. Organic aerosols associated with the generation of reactive oxygen species (ROS) by water-soluble PM2.5.

    PubMed

    Verma, Vishal; Fang, Ting; Xu, Lu; Peltier, Richard E; Russell, Armistead G; Ng, Nga Lee; Weber, Rodney J

    2015-04-01

    We compare the relative toxicity of various organic aerosol (OA) components identified by an aerosol mass spectrometer (AMS) based on their ability to generate reactive oxygen species (ROS). Ambient fine aerosols were collected from urban (three in Atlanta, GA and one in Birmingham, AL) and rural (Yorkville, GA and Centerville, AL) sites in the Southeastern United States. The ROS generating capability of the water-soluble fraction of the particles was measured by the dithiothreitol (DTT) assay. Water-soluble PM extracts were further separated into the hydrophobic and hydrophilic fractions using a C-18 column, and both fractions were analyzed for DTT activity and water-soluble metals. Organic aerosol composition was measured at selected sites using a high-resolution time-of-flight AMS. Positive matrix factorization of the AMS spectra resolved the organic aerosol into isoprene-derived OA (Isop_OA), hydrocarbon-like OA (HOA), less-oxidized oxygenated OA, (LO-OOA), more-oxidized OOA (MO-OOA), cooking OA (COA), and biomass burning OA (BBOA). The association of the DTT activity of water-soluble PM2.5 (WS_DTT) with these factors was investigated by linear regression techniques. BBOA and MO-OOA were most consistently linked with WS_DTT, with intrinsic water-soluble activities of 151 ± 20 and 36 ± 22 pmol/min/μg, respectively. Although less toxic, MO-OOA was most widespread, contributing to WS_DTT activity at all sites and during all seasons. WS_DTT activity was least associated with biogenic secondary organic aerosol. The OA components contributing to WS_DTT were humic-like substances (HULIS), which are abundantly emitted in biomass burning (BBOA) and include highly oxidized OA from multiple sources (MO-OOA). Overall, OA contributed approximately 60% to the WS_DTT activity, with the remaining probably from water-soluble metals, which were mostly associated with the hydrophilic WS_DTT fraction. PMID:25748105

  8. Chromatographic profiles of nonstructural carbohydrates contributing to the colorimetrically determined fructan, ethanol-soluble, and water-soluble carbohydrate contents of five grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nonstructural carbohydrates in forages are often analyzed by colorimetric assays of water and ethanol extracts. Water-soluble carbohydrates (WSC) include polysaccharides (starch and fructan) and mono- and disaccharides. Ethanol-soluble carbohydrates (ESC) consist only of mono-, di- and oligosaccha...

  9. One-year water sorption and solubility of "all-in-one" adhesives.

    PubMed

    Walter, Ricardo; Feiring, Andrew E; Boushell, Lee W; Braswell, Krista; Bartholomew, Whitley; Chung, Yunro; Phillips, Ceib; Pereira, Patricia N R; Swift, Edward J

    2013-01-01

    The aim of this study was to evaluate the water sorption and solubility of different adhesives. Adper Easy Bond, Adper Single Bond Plus, Bond Force, Clearfil SE Bond (bonding resin only), and Xeno IV were the materials evaluated. Ten disks of each adhesive were made in Teflon molds and evaporation of any volatile components was allowed. The disks were weighed daily in an analytical balance until a constant mass was obtained (m1). Disks were then immersed in water for 12 months when their wet weight was recorded (m2). The disks were again weighed daily until a constant mass was obtained and the final weight recorded (m3). Water sorption and solubility (percentages) were calculated using the recorded mass values. Kruskal-Wallis tests were used to compare the average water sorption and solubility among the different adhesives. Mann-Whitney tests with a Bonferroni correction were used to determine the pairwise differences between adhesives in water sorption and solubility. The level of significance was set at 0.05. Water sorption and solubility were significantly different among the groups (p<0.05). Pairwise comparisons showed no significant differences (p>0.05) between Adper Single Bond Plus and Bond Force, or between Clearfil SE Bond and Xeno IV in either water sorption or solubility. Xeno IV did not differ from Adper Easy Bond in water sorption (p>0.05). Water sorption and solubility of all-in-one adhesives increased with time, and the rates of increase were composition-dependent. The results suggest that monomers other than HEMA contribute to water sorption and solubility of adhesive systems from different categories. PMID:24173253

  10. RESPONSE OF LEAD SOLUBILITY TO DISSOLVED CARBONATE IN DRINKING WATER

    EPA Science Inventory

    A model is presented showing the detailed response of the theoretical solubility curves for lead to changes in dissolved inorganic carbonate concentration (TIC) and pH at 25 C. Aqueous Pb(II) ion, lead carbonate complexes, lead hydroxide monomers and polymers, and the solids lead...

  11. Analytically useful blue chemiluminescence from a water-soluble iridium(III) complex containing a tetraethylene glycol functionalised triazolylpyridine ligand.

    PubMed

    Smith, Zoe M; Kerr, Emily; Doeven, Egan H; Connell, Timothy U; Barnett, Neil W; Donnelly, Paul S; Haswell, Stephen J; Francis, Paul S

    2016-04-01

    We examine [Ir(df-ppy)2(pt-TEG)](+) as the first highly water soluble, blue-luminescent iridium(III) complex for chemiluminescence detection. Marked differences in selectivity were observed between the new complex and the conventional [Ru(bpy)3](2+) reagent, which will enable this mode of detection to be extended to new areas of application. PMID:26915962

  12. Value Added Processing of Peanut Meal: Enzymatic Hydrolysis to Improve Functional and Nutritional Properties of Water Soluble Extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Value added applications are needed for peanut meal, which is the high protein byproduct of commercial peanut oil production. Peanut meal dispersions were hydrolyzed with alcalase, flavourzyme and pepsin in an effort to improve functional and nutritional properties of the resulting water soluble ex...

  13. Bidirectional Transformation of a Metamorphic Protein between the Water-Soluble and Transmembrane Native States.

    PubMed

    Tanaka, Koji; Caaveiro, Jose M M; Tsumoto, Kouhei

    2015-11-24

    The bidirectional transformation of a protein between its native water-soluble and integral transmembrane conformations is demonstrated for FraC, a hemolytic protein of the family of pore-forming toxins. In the presence of biological membranes, the water-soluble conformation of FraC undergoes a remarkable structural reorganization generating cytolytic transmembrane nanopores conducive to cell death. So far, the reverse transformation from the native transmembrane conformation to the native water-soluble conformation has not been reported. We describe the use of detergents with different physicochemical properties to achieve the spontaneous conversion of transmembrane pores of FraC back into the initial water-soluble state. Thermodynamic and kinetic stability data suggest that specific detergents cause an asymmetric change in the energy landscape of the protein, allowing the bidirectional transformation of a membrane protein. PMID:26544760

  14. Water soluble nanocurcumin extracted from turmeric challenging the microflora from human oral cavity.

    PubMed

    Gopal, Judy; Muthu, Manikandan; Chun, Se-Chul

    2016-11-15

    Water soluble nanocurcumin prepared from commercial turmeric powders was compared against ethanol extracted curcumin particles. The oral microflora from five different human volunteers was collected and the efficacy of solvent extracted curcumin versus water extracted nanocurcumin was demonstrated. Nanocurcumin activity against oral microflora confirms its antimicrobial potency. Confocal laser scanning microscopic results revealed the enhanced entry of nanocurcumin particles into microbial cells. The nanosized nature of nanocurcumin appears to have led to increased cellular interaction and thereby efficient destruction of microbial cells in the mouth. In addition, solubility of nanocurcumin is also believed to be a crucial factor behind its successful antimicrobial activity. This study proves that the bioactivity of a compound is greatly influenced by its solubility in water. This work recommends the use of water soluble nanocurcumin (extracted from turmeric) as potent substitute for curcumin in dental formulations. PMID:27283711

  15. Preparative scale and convenient synthesis of a water-soluble, deep cavitand.

    PubMed

    Mosca, Simone; Yu, Yang; Rebek, Julius

    2016-08-01

    Cavitands are established tools of supramolecular chemistry and molecular recognition, and they are finding increasing application in sensing and sequestration of physiologically relevant molecules in aqueous solution. The synthesis of a water-soluble, deep cavitand is described. The route comprises six (linear) steps from commercially available precursors, and it relies on the fourfold oligomeric cyclization reaction of resorcinol with 2,3-dihydrofuran that leads to the formation of a shallow resorcinarene framework; condensation with aromatic panels, which deepens the hydrophobic binding cavity; construction of rigid urea functionalities on the upper rim; and the introduction of the water-solubilizing methylimidazolium groups on the lower rim. Late intermediates of the synthesis can be used in the preparation of congener cavitands with different properties and applications, and a sample of such a synthetic procedure is included in this protocol. Emphasis is placed on scaled-up reactions and on purification procedures that afford materials in high yield and avoid chromatographic purification. This protocol provides improvements over previously described procedures, and it enables the preparation of sizable amounts of deep cavitands: 7 g of a water-soluble cavitand can be prepared from resorcinol in 13 working days. PMID:27388554

  16. A highly soluble, non-phototoxic, non-fluorescent blebbistatin derivative.

    PubMed

    Várkuti, Boglárka H; Képiró, Miklós; Horváth, István Ádám; Végner, László; Ráti, Szilvia; Zsigmond, Áron; Hegyi, György; Lenkei, Zsolt; Varga, Máté; Málnási-Csizmadia, András

    2016-01-01

    Blebbistatin is a commonly used molecular tool for the specific inhibition of various myosin II isoforms both in vitro and in vivo. Despite its popularity, the use of blebbistatin is hindered by its poor water-solubility (below 10 micromolar in aqueous buffer) and blue-light sensitivity, resulting in the photoconversion of the molecule, causing severe cellular phototoxicity in addition to its cytotoxicity. Furthermore, blebbistatin forms insoluble aggregates in water-based media above 10 micromolar with extremely high fluorescence and also high adherence to different types of surfaces, which biases its experimental usage. Here, we report a highly soluble (440 micromolar in aqueous buffer), non-fluorescent and photostable C15 amino-substituted derivative of blebbistatin, called para-aminoblebbistatin. Importantly, it is neither photo- nor cytotoxic, as demonstrated on HeLa cells and zebrafish embryos. Additionally, para-aminoblebbistatin bears similar myosin II inhibitory properties to blebbistatin or para-nitroblebbistatin (not to be confused with the C7 substituted nitroblebbistatin), tested on rabbit skeletal muscle myosin S1 and on M2 and HeLa cells. Due to its drastically improved solubility and photochemical feature, as well as lack of photo- or cytotoxicity, para-aminoblebbistatin may become a feasible replacement for blebbistatin, especially at applications when high concentrations of the inhibitor or blue light irradiation is required. PMID:27241904

  17. A highly soluble, non-phototoxic, non-fluorescent blebbistatin derivative

    PubMed Central

    Várkuti, Boglárka H.; Képiró, Miklós; Horváth, István Ádám; Végner, László; Ráti, Szilvia; Zsigmond, Áron; Hegyi, György; Lenkei, Zsolt; Varga, Máté; Málnási-Csizmadia, András

    2016-01-01

    Blebbistatin is a commonly used molecular tool for the specific inhibition of various myosin II isoforms both in vitro and in vivo. Despite its popularity, the use of blebbistatin is hindered by its poor water-solubility (below 10 micromolar in aqueous buffer) and blue-light sensitivity, resulting in the photoconversion of the molecule, causing severe cellular phototoxicity in addition to its cytotoxicity. Furthermore, blebbistatin forms insoluble aggregates in water-based media above 10 micromolar with extremely high fluorescence and also high adherence to different types of surfaces, which biases its experimental usage. Here, we report a highly soluble (440 micromolar in aqueous buffer), non-fluorescent and photostable C15 amino-substituted derivative of blebbistatin, called para-aminoblebbistatin. Importantly, it is neither photo- nor cytotoxic, as demonstrated on HeLa cells and zebrafish embryos. Additionally, para-aminoblebbistatin bears similar myosin II inhibitory properties to blebbistatin or para-nitroblebbistatin (not to be confused with the C7 substituted nitroblebbistatin), tested on rabbit skeletal muscle myosin S1 and on M2 and HeLa cells. Due to its drastically improved solubility and photochemical feature, as well as lack of photo- or cytotoxicity, para-aminoblebbistatin may become a feasible replacement for blebbistatin, especially at applications when high concentrations of the inhibitor or blue light irradiation is required. PMID:27241904

  18. Water-soluble and solid-state speciation of phosphorus in stabilized sewage sludge.

    PubMed

    Huang, Xiao-Lan; Shenker, Moshe

    2004-01-01

    Three chemicals, ferrous sulfate (Fe-sul), calcium oxide (CaO), and aluminum sulfate (alum), were used to stabilize phosphorus (P) in fresh, anaerobically digested sewage sludge (FSS). The chemically stabilized sludge materials and biosolids compost (BSC) were compared with the FSS with respect to water-soluble phosphorus (WSP) content in its inorganic (WSP(i)) and organic (WSP(o)) forms as well as water-soluble organic carbon (DOC). Solid-state P speciation was further probed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy-dispersive X-ray elemental spectrometry (EDXS). Water-soluble P was effectively controlled by a wide range of Fe-sul or CaO additions to the sludge (Ca to P ratio = 3.47-17.72, Fe to P ratio = 1.01-16.53), but by only a narrow range (Al to P ratio = 1.04-2.87) of alum addition. The WSP content in the BSC was also depressed, but to a lesser extent. The pH in the treated sludge ranged from 3.0 to 12.5 and served as a key factor to control P chemistry. No correlation was observed between DOC and WSP(o). No crystallized Ca-P minerals were detected in the CaO-stabilized sludge, but brushite crystallization seemed to be obtained by low addition of Fe-sul and alum. Variscite and strengite crystallization was obtained following high addition of Fe-sul or alum, as detected by XRD and SEM-EDXS. Adsorption of P by newly formed Fe-hydroxide seems to play an important role in the Fe-sul-stabilized sludge. We concluded that administration of the tested chemicals at the proper rate can effectively reduce the hazard of P release and leaching from sludge. PMID:15356251

  19. Application of dry-polishing techniques to water-soluble glass ceramics

    SciTech Connect

    Healey, J.T.; McAllaster, M.E.

    1981-04-01

    A dry polishing technique is presented for the preparation of glass ceramics for microstructural characterization. The technique is shown to be applicable to water soluble phosphate based glass ceramics and also to a non-water soluble zinc silicate glass ceramic. Microstructural characterization is performed primarily with composition backscattered electron imaging in the scanning electron microscopy. Some relief is observed on the polished surface utilizing topographical backscattered electron imaging.

  20. Effect of alumina on water solubility in lower mantle ferropericlase: preliminary results

    NASA Astrophysics Data System (ADS)

    Litasov, K. D.; Ohtani, E.

    2003-04-01

    Recent results of high-pressure studies on H_2O solubility in the lower mantle magnesiowustite (ferropericlase, Mg#>50) are very controversial. Murakami et al. (2002) reported SIMS and FTIR data for ferropericlase, synthesized at 25-27 GPa from peridotite composition, and found about 0.2 wt% (2000 ppm) H_2O. However, Bolfan-Casanova et al. (2000; 2002) measured only 20-25 ppm H_2O in MgO and ferropericlase (Mg0.93Fe0.07)O by FTIR. It was suggested by many authors that water solubility may increase with incorporation of trivalent cations to the structure of lower mantle ferropericlase and perovskite. Ferropericlase obtained from natural compositions at high pressures contains up to 2-3 wt% of Al_2O_3. Here we present preliminary FTIR results on water solubility in Al-bearing ferropericlase. The experiments were carried out at 25 GPa and 1400-1800^oC. 3 wt% of Al_2O_3 and 10 wt% of H_2O as brucite were added to periclase and ferropericlase (Mg#=88) and used as the starting materials. FTIR spectra were obtained from double polished thin section of the samples with 0.05-0.11 mm thickness. IR spectra of periclase show weak bands at 3299, 3308, and 3404 cm-1. Ferropericlase has major bands at 3299 and 3474 cm-1. The H_2O contents were calculated from height of the major peak at 3299 cm-1. Calculated H_2O content in periclase is 14±6 ppm at 1400^oC (Al_2O_3 in periclase is 0.7 wt%) and 30±11 ppm at 1800^oC (Al_2O_3=1.2 wt%). Water content in ferropericlase is 15±7 ppm at 1400^oC (Al_2O_3=1.0 wt%) and 63±12 ppm at 1800^oC (Al_2O_3=2.2 wt%). These data indicate that (1) ferropericlase (Mg#=88) contains more water and Al_2O_3 relative to periclase and (2) water contents in periclase and ferropericlase increase with increasing temperature and Al_2O_3. The present results indicate that water solubility in ferropericlase related to natural fertile peridotite is restricted. This is consistent with the data by Bolfan-Casanova et al. (2002). Ferropericlase can not be

  1. Water-soluble polyelectrolyte complexes of Astramol poly(propyleneimine) dendrimers with poly(methacrylate) anion.

    PubMed

    Zhiryakova, Marina V; Izumrudov, Vladimir A

    2014-11-26

    Water-soluble complexes formed by pyrenyl-tagged poly(methacrylate) anion with cationic DAB-dendr-(NH2)x of five generations, x = 4, 8, 16, 32, and 64 were prepared and studied. The ability of the dendrimers to quench the pyrenyl fluorescence was used to monitor formation/dissociation of the complexes by fluorescence quenching technique. In salt-free solutions, dissociation of the complexes occurred in highly acidic and highly alkaline media independently on the dendrimer generation, whereas stability of the complexes against destruction by added salt (NaCl) enhanced markedly with x increase. Phase separations were dependent on pH and charged ratio of the components, but independent of a dendrimer generation. By contrast, in water-salt solutions the generation had a profound impact on phase diagram manifested by a considerable extension of a heterogeneity region as x increased. These findings strongly suggest that the complexes obey the main regularities ascertained for polyelectrolyte complexes of oppositely charged polyions. The revealed possibility of preparing negatively charged and positively charged complexes with controllable stability and solubility demonstrates potentialities of Astramol dendrimers for design self-assembled and self-adjusted systems attractive for biotechnological and biomedical applications. PMID:25369241

  2. Lubrication of starch in ionic liquid-water mixtures: Soluble carbohydrate polymers form a boundary film on hydrophobic surfaces.

    PubMed

    Yakubov, Gleb E; Zhong, Lei; Li, Ming; Boehm, Michael W; Xie, Fengwei; Beattie, David A; Halley, Peter J; Stokes, Jason R

    2015-11-20

    Soluble starch polymers are shown to enhance the lubrication of ionic liquid-water solvent mixtures in low-pressure tribological contacts between hydrophobic substrates. A fraction of starch polymers become highly soluble in 1-ethyl-3-methylimidazolium acetate (EMIMAc)-water solvents with ionic liquid fraction ≥60wt%. In 65wt% EMIMAc, a small amount of soluble starch (0.33wt%) reduces the boundary friction coefficient by up to a third in comparison to that of the solvent. This low-friction is associated with a nanometre thick film (ca. 2nm) formed from the amylose fraction of the starch. In addition, under conditions where there is a mixture of insoluble starch particles and solubilised starch polymers, it is found that the presence of dissolved amylose enhances the lubrication of starch suspensions between roughened substrates. These findings open up the possibility of utilising starch biopolymers, as well as other hydrocolloids, for enhancing the performance of ionic liquid lubricants. PMID:26344308

  3. WATER ACTIVITY DATA ASSESSMENT TO BE USED IN HANFORD WASTE SOLUBILITY CALCULATIONS

    SciTech Connect

    DISSELKAMP RS

    2011-01-06

    The purpose of this report is to present and assess water activity versus ionic strength for six solutes:sodium nitrate, sodium nitrite, sodium chloride, sodium carbonate, sodium sulfate, and potassium nitrate. Water activity is given versus molality (e.g., ionic strength) and temperature. Water activity is used to estimate Hanford crystal hydrate solubility present in the waste.

  4. Photocatalytic hydrogen production from a simple water-soluble [FeFe]-hydrogenase model system.

    PubMed

    Cao, Wei-Ning; Wang, Feng; Wang, Hong-Yan; Chen, Bin; Feng, Ke; Tung, Chen-Ho; Wu, Li-Zhu

    2012-08-21

    Combined with a simple water soluble [FeFe]-hydrogenase mimic 1, Ru(bpy)(3)(2+) and ascorbic acid enable hydrogen production photocatalytically. More than 88 equivalents of H(2) were achieved in water, which is much better than that obtained in an organic solvent or a mixture of organic solvent and water. PMID:22772838

  5. Characteristics of new particle formation events in Nanjing, China: Effect of water-soluble ions

    NASA Astrophysics Data System (ADS)

    An, Junlin; Wang, Honglei; Shen, Lijuan; Zhu, Bin; Zou, Jianan; Gao, Jinhui; Kang, Hanqing

    2015-05-01

    New particle formation (NPF) events and water-soluble ions were studied at the meteorological building on the campus of the Nanjing University of Information Science and Technology (NUIST), which is located in the western part of the Yangtze River Delta (YRD). A wide-range particle spectrometer (WPS) provided particle number size distributions between 10 nm and 10 μm, whereas water-soluble ions for particles with diameters between 10 nm and 18 μm were measured using a 13-stage Nano-MOUDI aerosol sampler and 850 professional Ion Chromatography (IC). Additionally, meteorological data, trace gas concentrations and mass concentration were recorded. Ten NPF days were captured during the measurement period from 08 July to 02 August 2012. The mean aerosol number concentration, which was primarily composed of Aitken-mode particles, i.e., with diameters of 20-100 nm, was 13,664 cm-3, which was 1.9 times larger than that on non-NPF days. The results suggest that the NPF events were only slightly affected by O3, SO2, and NO2; the primary factors affecting NPF events were meteorological factors and air mass directions. NPF events were found to be favorable during the summer in the presence of high temperatures, strong radiation, low humidity, strong winds and clean air masses originating from the southeastern coast. The mean growth rate (GR), formation rate (J10), condensational sink (CS), condensing vapor rate (Q), and condensation vapor (C) were determined to be 7.6 nm h-1, 3.7 cm-3 s-1, 2.8 × 10-2 s-1, 2.9 × 106 cm-3 s-1, and 10.5 × 107 cm-3, respectively, on NPF days. The largest effects of the studied NPF events were on the mass and water-soluble ion concentrations of Aitken-mode particles, followed by nuclei-mode particles; few contributions to accumulation- and coarse-mode particles were observed. Different water-soluble ions were observed to have distinct interactions with the NPF events. The proportions of NH4+, SO42-, NO3-, K+ and Mg2+ in nuclei- and Aitken

  6. Prediction of solubilities for ginger bioactive compounds in hot water by the COSMO-RS method

    NASA Astrophysics Data System (ADS)

    Zaimah Syed Jaapar, Syaripah; Azian Morad, Noor; Iwai, Yoshio

    2013-04-01

    The solubilities in water of four main ginger bioactives, 6-gingerol, 6-shogaol, 8-gingerol and 10-gingerol, were predicted using a conductor-like screening model for real solvent (COSMO-RS) calculations. This study was conducted since no experimental data are available for ginger bioactive solubilities in hot water. The σ-profiles of these selected molecules were calculated using Gaussian software and the solubilities were calculated using the COSMO-RS method. The solubilities of these ginger bioactives were calculated at 50 to 200 °C. In order to validate the accuracy of the COSMO-RS method, the solubilities of five hydrocarbon molecules were calculated using the COSMO-RS method and compared with the experimental data in the literature. The selected hydrocarbon molecules were 3-pentanone, 1-hexanol, benzene, 3-methylphenol and 2-hydroxy-5-methylbenzaldehyde. The calculated results of the hydrocarbon molecules are in good agreement with the data in the literature. These results confirm that the solubilities of ginger bioactives can be predicted using the COSMO-RS method. The solubilities of the ginger bioactives are lower than 0.0001 at temperatures lower than 130 °C. At 130 to 200 °C, the solubilities increase dramatically with the highest being 6-shogaol, which is 0.00037 mole fraction, and the lowest is 10-gingerol, which is 0.000039 mole fraction at 200 °C.

  7. The relationship between surface tension and the industrial performance of water-soluble polymers prepared from acid hydrolysis lignin, a saccharification by-product from woody materials.

    PubMed

    Matsushita, Yasuyuki; Imai, Masanori; Iwatsuki, Ayuko; Fukushima, Kazuhiko

    2008-05-01

    In this study, water-soluble anionic and cationic polymers were prepared from sulfuric acid lignin (SAL), an acid hydrolysis lignin, and the relationship between the surface tension of these polymers and industrial performance was examined. The SAL was phenolized (P-SAL) to enhance its solubility and reactivity. Sulfonation and the Mannich reaction with aminocarboxylic acids produced water-soluble anionic polymers and high-dispersibility gypsum paste. The dispersing efficiency increased as the surface tension decreased, suggesting that the fluidity of the gypsum paste increased with the polymer adsorption on the gypsum particle surface. Water-soluble cationic polymers were prepared using the Mannich reaction with dimethylamine. The cationic polymers showed high sizing efficiency under neutral papermaking conditions; the sizing efficiency increased with the surface tension. This suggests that the polymer with high hydrophilicity spread in the water and readily adhered to the pulp surface and the rosin, showing good retention. PMID:17664066

  8. Synthesis, characterization and fluorescent properties of water-soluble glycopolymer bearing curcumin pendant residues.

    PubMed

    Zhang, Haisong; Yu, Meng; Zhang, Hailei; Bai, Libin; Wu, Yonggang; Wang, Sujuan; Ba, Xinwu

    2016-08-01

    Curcumin is a potential natural anticancer drug with low oral bioavailability because of poor water solubility. The aqueous solubility of curcumin is enhanced by means of modification with the carbohydrate units. Polymerization of the curcumin-containing monomer with carbohydrate-containing monomer gives the water-soluble glycopolymer bearing curcumin pendant residues. The obtained copolymers (P1 and P2) having desirable water solubility were well-characterized by infrared spectroscopy (IR), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), UV-Vis absorption spectroscopy, and photoluminescence spectroscopy. The copolymer P2 with a molar ratio of 1:6 (curcumin/carbohydrate) calculated from the proton NMR results exhibits a similar anticancer activity compared to original curcumin, which may serve as a potential chemotherapeutic agent in the field of anticancer medicine. PMID:27098211

  9. Simultaneous determination of water-soluble vitamins by over-pressure layer chromatography and photodensitometric detection.

    PubMed

    Postaire, E; Cisse, M; Le Hoang, M D; Pradeau, D

    1991-04-01

    An over-pressure layer chromatographic procedure with photodensitometric detection for the simultaneous determination of water-soluble vitamins in multivitamin pharmaceutical preparations was developed and evaluated. The method uses high-performance TLC (HPTLC) plates with silica gel as the thin-layer, and an n-butanol:pyridine:water mixture (50:35:15, v/v/v) as mobile phase at a rate of 0.25 mL/min for baseline separation. The quantitation was carried out without derivatization (vitamin B1, vitamin B2, vitamin B6, folic acid, nicotinamide, vitamin C) or after spraying ninhydrin reagent (calcium pantothenate) or 4-dimethylaminocinnamaldehyde (vitamin B12, biotin). This was applied to the analysis of multivitamin solutions. Satisfactory relative standard deviations and good recovery were obtained for all the vitamins examined. It was concluded that this method is fast, accurate, specific, and suitable for routine quality control use. PMID:1865338

  10. The water cycles of water-soluble organic salts of atmospheric importance

    NASA Astrophysics Data System (ADS)

    Peng, Changgeng; Chan, Chak K.

    In this study, the water cycles of nine water-soluble organic salts of atmospheric interest were studied using an electrodynamic balance (EDB) at 25°C. Sodium formate, sodium acetate, sodium succinate, sodium pyruvate and sodium methanesulfonate (Na-MSA) particles crystallize as the relative humidity (RH) decreases and they deliquesce as the RH increases. Sodium oxalate and ammonium oxalate form supersaturated particles at low RH before crystallization but they do not deliquesce even at RH=90%. Sodium malonate and sodium maleate particles neither crystallize nor deliquesce. These two salts absorb and evaporate water reversibly without hysteresis. In most cases, the solid states of single particles resulting from the crystallization of supersaturated droplets do not form the most thermodynamically stable state found in bulk studies. Sodium formate, sodium oxalate, ammonium oxalate, sodium succinate, sodium pyruvate and Na-MSA form anhydrous particles after crystallization. Sodium acetate forms particles with a water/salt molar ratio of 0.5 after crystallization. In salts with several hydrated states including sodium formate and sodium acetate, the particles deliquesce at the lowest deliquescence relative humidity (DRH) of the hydrates. Except sodium oxalate and ammonium oxalate, all the salts studied here are as hygroscopic as typical inorganic hygroscopic aerosols. The hygroscopic organic salts have a growth factor of 1.76-2.18 from RH=10-90%, comparable to that of typical hygroscopic inorganic salts such as NaCl and (NH 4) 2SO 4. Further study of other atmospheric water-soluble organic compounds and their mixtures with inorganic salts is needed to explain the field observations of the hygroscopic growth of ambient aerosols.

  11. Method of immobilizing water-soluble bioorganic compounds on a capillary-porous carrier

    DOEpatents

    Ershov, Gennady Moiseevich; Timofeev, Eduard Nikolaevich; Ivanov, Igor Borisovich; Florentiev, Vladimir Leonidovich; Mirzabekov, Andrei Darievich

    1998-01-01

    The method for immobilizing water-soluble bioorganic compounds to capillary-porous carrier comprises application of solutions of water-soluble bioorganic compounds onto a capillary-porous carrier, setting the carrier temperature equal to or below the dew point of the ambient air, keeping the carrier till appearance of water condensate and complete swelling of the carrier, whereupon the carrier surface is coated with a layer of water-immiscible nonluminescent inert oil and is allowed to stand till completion of the chemical reaction of bonding the bioorganic compounds with the carrier.

  12. Antibacterial effect of water-soluble chitosan on representative dental pathogens Streptococcus mutans and Lactobacilli brevis

    PubMed Central

    CHEN, Chih-YU; CHUNG, Ying-CHIEN

    2012-01-01

    Dental caries is still a major oral health problem in most industrialized countries. The development of dental caries primarily involves Lactobacilli spp. and Streptococcus mutans. Although antibacterial ingredients are used against oral bacteria to reduce dental caries, some reports that show partial antibacterial ingredients could result in side effects. Objectives The main objective is to test the antibacterial effect of water-soluble chitosan while the evaluation of the mouthwash appears as a secondary aim. Material and Methods The chitosan was obtained from the Application Chemistry Company (Taiwan). The authors investigated the antibacterial effects of water-soluble chitosan against oral bacteria at different temperatures (25-37ºC) and pH values (pH 5-8), and evaluated the antibacterial activities of a self-made water-soluble chitosan-containing mouthwash by in vitro and in vivo experiments, and analyzed the acute toxicity of the mouthwashes. The acute toxicity was analyzed with the pollen tube growth (PTG) test. The growth inhibition values against the logarithmic scale of the test concentrations produced a concentrationresponse curve. The IC50 value was calculated by interpolation from the data. Results The effect of the pH variation (5-8) on the antibacterial activity of water-soluble chitosan against tested oral bacteria was not significant. The maximal antibacterial activity of water-soluble chitosan occurred at 37ºC. The minimum bactericidal concentration (MBC) of water-soluble chitosan on Streptococcus mutans and Lactobacilli brevis were 400 µg/mL and 500 µg/mL, respectively. Only 5 s of contact between water-soluble chitosan and oral bacteria attained at least 99.60% antibacterial activity at a concentration of 500 µg/mL. The water-soluble chitosan-containin g mouthwash significantly demonstrated antibacterial activity that was similar to that of commercial mouthwashes (>99.91%) in both in vitro and in vivo experiments. In addition, the alcohol

  13. Liposomal buccal mucoadhesive film for improved delivery and permeation of water-soluble vitamins.

    PubMed

    Abd El Azim, Heba; Nafee, Noha; Ramadan, Alyaa; Khalafallah, Nawal

    2015-07-01

    This study aims at improving the buccal delivery of vitamin B6 (VB6) as a model highly water-soluble, low permeable vitamin. Two main strategies were combined; first VB6 was entrapped in liposomes, which were then formulated as mucoadhesive film. Both plain and VB6-loaded liposomes (LPs) containing Lipoid S100 and propylene glycol (∼ 200 nm) were then incorporated into mucoadhesive film composed of SCMC and HPMC. Results showed prolonged release of VB6 (72.65%, T50% diss 105 min) after 6h from LP-film compared to control film containing free VB6 (96.37%, T50% diss 30 min). Mucoadhesion was assessed both ex vivo on chicken pouch and in vivo in human. Mucoadhesive force of 0.2N and residence time of 4.4h were recorded. Ex vivo permeation of VB6, across chicken pouch mucosa indicated increased permeation from LP-systems compared to corresponding controls. Interestingly, incorporation of the vesicles in mucoadhesive film reduced the flux by 36.89% relative to LP-dispersion. Meanwhile, both films provided faster initial permeation than the liquid forms. Correlating the cumulative percent permeated ex vivo with the cumulative percent released in vitro indicated that LPs retarded VB6 release but improved permeation. These promising results represent a step forward in the field of buccal delivery of water-soluble vitamins. PMID:25899288

  14. Formation of water-soluble metal cyanide complexes from solid minerals by Pseudomonas plecoglossicida.

    PubMed

    Faramarzi, Mohammad A; Brandl, Helmut

    2006-06-01

    A few Pseudomonas species are able to form hydrocyanic acid (HCN), particularly when grown under glycine-rich conditions. In the presence of metals, cyanide can form water-soluble metal complexes of high chemical stability. We studied the possibility to mobilize metals as cyanide complexes from solid minerals using HCN-forming microorganisms. Pseudomonas plecoglossicida was cultivated in the presence of copper- and nickel-containing solid minerals. On powdered elemental nickel, fast HCN generation within the first 12 h of incubation was observed and water-soluble tetracyanaonickelate was formed. Cuprite, tenorite, chrysocolla, malachite, bornite, turquoise, millerite, pentlandite as well as shredded electronic scrap was also subjected to a biological treatment. Maximum concentrations of cyanide-complexed copper corresponded to a solubilization of 42% and 27% when P. plecoglossicida was grown in the presence of cuprite or tenorite, respectively. Crystal system, metal oxidation state and mineral hydrophobicity might have a significant influence on metal mobilization. However, it was not possible to allocate metal mobilization to a single mineral property. Cyanide-complexed gold was detected during growth on manually cut circuit boards. Maximum dicyanoaurate concentration corresponded to a 68.5% dissolution of the total gold added. These findings represent a novel type of microbial mobilization of nickel and copper from solid minerals based on the ability of certain microbes to form HCN. PMID:16684101

  15. Novel high/low solubility classification methods for new molecular entities.

    PubMed

    Dave, Rutwij A; Morris, Marilyn E

    2016-09-10

    This research describes a rapid solubility classification approach that could be used in the discovery and development of new molecular entities. Compounds (N=635) were divided into two groups based on information available in the literature: high solubility (BDDCS/BCS 1/3) and low solubility (BDDCS/BCS 2/4). We established decision rules for determining solubility classes using measured log solubility in molar units (MLogSM) or measured solubility (MSol) in mg/ml units. ROC curve analysis was applied to determine statistically significant threshold values of MSol and MLogSM. Results indicated that NMEs with MLogSM>-3.05 or MSol>0.30mg/mL will have ≥85% probability of being highly soluble and new molecular entities with MLogSM≤-3.05 or MSol≤0.30mg/mL will have ≥85% probability of being poorly soluble. When comparing solubility classification using the threshold values of MLogSM or MSol with BDDCS, we were able to correctly classify 85% of compounds. We also evaluated solubility classification of an independent set of 108 orally administered drugs using MSol (0.3mg/mL) and our method correctly classified 81% and 95% of compounds into high and low solubility classes, respectively. The high/low solubility classification using MLogSM or MSol is novel and independent of traditionally used dose number criteria. PMID:27349790

  16. Water-soluble cellulose acetate from waste cotton fabrics and the aqueous processing of all-cellulose composites.

    PubMed

    Cao, Jie; Sun, Xunwen; Lu, Canhui; Zhou, Zehang; Zhang, Xinxing; Yuan, Guiping

    2016-09-20

    The objective of this study is to explore the possibility of using waste cotton fabrics (WCFs) as low cost feedstock for the production of value-added products. Our previous study (Tian et al., 2014) demonstrated that acidic ionic liquids (ILs) can be highly efficient catalysts for controllable synthesis of cellulose acetate (CA) due to their dual function of swelling and catalyzing. In this study, an optimized "quasi-homogeneous" process which required a small amount of acidic ILs as catalyst was developed to synthesize water-soluble CA from WCFs. The process was optimized by varying the amounts of ILs and the reaction time. The highest conversion of water-soluble CA from WCFs reached 90.8%. The structure of the obtained water-soluble CA was characterized and compared with the original WCFs. Moreover, we demonstrate for the first time that fully bio-based and transparent all-cellulose composites can be fabricated by simple aqueous blending of the obtained water-soluble CA and two kinds of nanocelluloses (cellulose nanocrystals and cellulose nanofibrils), which is attractive for the applications in disposable packaging materials, sheet coating and binders, etc. PMID:27261730

  17. Sources and light absorption of water-soluble organic carbon aerosols in the outflow from northern China

    NASA Astrophysics Data System (ADS)

    Kirillova, E. N.; Andersson, A.; Han, J.; Lee, M.; Gustafsson, Ö.

    2014-02-01

    High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over one billion people and impact the regional climate. A large fraction (17-80%) of this aerosol carbon is water-soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble "brown carbon" and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual carbon isotopes with light-absorption measurements of water-soluble organic carbon (WSOC) for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from northern China. The mass absorption cross section at 365 nm (MAC365) of WSOC for air masses from N. China were in general higher (0.8-1.1 m2 g-1), than from other source regions (0.3-0.8 m2 g-1). However, this effect corresponds to only 2-10% of the radiative forcing caused by light absorption by elemental carbon. Radiocarbon constraints show that the WSOC in Chinese outflow had significantly higher fraction fossil sources (30-50%) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (δ13C) measurements were consistent with aging during long-range air mass transport for this large fraction of carbonaceous aerosols.

  18. Superwetting double-layer polyester materials for effective removal of both insoluble oils and soluble dyes in water.

    PubMed

    Li, Bucheng; Wu, Lei; Li, Lingxiao; Seeger, Stefan; Zhang, Junping; Wang, Aiqin

    2014-07-23

    Inspired by the mussel adhesive protein and the lotus leaf, Ag-based double-layer polyester (DL-PET) textiles were fabricated for effective removal of organic pollutants in water. The DL-PET textiles are composed of a top superamphiphilic layer and a bottom superhydrophobic/superoleophilic layer. First, the PET textiles were modified with a layer of polydopamine (PDA) and deposited with Ag nanoparticles to form the PET@PDA@Ag textiles. The top superamphiphilic layer, formed by immobilizing Ag3PO4 nanoparticles on the PET@PDA@Ag textile, shows excellent visible-light photocatalytic activity. The bottom superhydrophobic/superoleophilic layer, formed by modifying the PET@PDA@Ag textile using dodecyl mercaptan, is mechanically, environmentally, and chemically very stable. The water-insoluble oils with low surface tension can penetrate both layers of the DL-PET textiles, while the water with soluble organic dyes can only selectively wet the top layer owing to their unique wettability. Consequently, the water-soluble organic contaminants in the collected water can be decomposed by the Ag3PO4 nanoparticles of the top layer under visible-light irradiation or even sunlight in room conditions. Thus, the DL-PET textiles can remove various kinds of organic pollutants in water including both insoluble oils and soluble dyes. The DL-PET textiles feature unique wettability, high oil/water separation efficiency, and visible-light photocatalytic activity. PMID:24956183

  19. Stability and removal of water soluble CdTe quantum dots in water.

    PubMed

    Zhang, Yang; Chen, Yongsheng; Westerhoff, Paul; Crittenden, John C

    2008-01-01

    Commercial use of quantum dots (GDs) will lead to their entry into aquatic environments. This study examines the characteristics and stability of CdTe QDs with thioglycolate capping ligands in water as well as their removal by alum salts. The capping ligands of QDs are a key factor in determining their fate in water. Protonated thioglycolate capping ligands cause QDs to aggregate. The stability of QDs depends more on their ionic composition in water than on the ionic strength. In KCl solution, QDs remain stable even under 0.15 M ionic strength. Relatively low concentrations (< or = 2 meq/L) of divalent (Mg2+ and Ca2+) or trivalent (Al3+) cations, however, can induce aggregation. The proposed mechanism for this phenomenon is that multivalent metal cations (or their hydrated species) react with capping ligands to form complexes that bridge QDs or neutralize their surface charges. Because the complexation of hydrated Al3+ with capping ligands inhibits the formation of Al(OH)3 precipitates, alum dosages higher than the A3+ solubility are required to form settleable flocs and remove QDs from nanopure water by sedimentation. Divalent cations (Mg2+ and Ca2+) in tap water induce the formation of settleable QD flocs such that 70-80% of the QGDs by mass settle out. PMID:18350915

  20. Assessing Junior High Students' Understanding of Density and Solubility.

    ERIC Educational Resources Information Center

    Gennaro, Eugene D.

    1981-01-01

    Three density questions were administered to 290 ninth-grade students to assess their understanding of this concept. Found two-thirds of students understand displacement and/or density concepts. Three solubility questions were administered to 385 ninth-graders to assess understandings of solubility. Found students have difficulty with some aspects…

  1. Comparison of water solubilities by the flask and micro-column methods

    SciTech Connect

    Hashimoto, Y.; Tokura, K.; Ozaki, K.; Strachan, W.M.J.

    1982-01-01

    A comparative examination of the two procedures of the ''OECD Test Guildeline: Water Solubility'' was undertaken using carbazole, fluoranthene, anthracene, hexachlorobenzene, p-nitroaniline and diphenylamine. The flask method was modified to provide for dissolution of the solute from the surface of glass beads. By the proposed flask method, one can accurately measure the water solubility down to the order of 10 ..mu..g/L as well as those of the order of %. The micro-column method, which requires a number of concentration determinations to ensure that a saturated solution has been obtained, is recommended for the solubility range of 10 mg/L through 10 ..mu..g/L. The flask method using the procedures described in this study, covers the range of solubility above 10 ..mu..g/L with only two determinations one being a simple preliminary test and the other a precise measurement.

  2. Outerwall-selectively oxidized, water soluble double-walled carbon nanotubes

    SciTech Connect

    Brozena, Alexandra H.; Moskovits, Martin; Shao, Beiyue; Deng, Shunliu; Liao, Hongwei; Gaskell, Karen L.; Wang, YuHuang

    2010-02-23

    The outer walls of double-walled carbon nanotubes (DWNTs) were selectively oxidized using a combination of oleum and nitric acid. Intercalation of oleum between bundled DWNTs enabled a homogeneous reaction by equally exposing all outer wall surfaces to the oxidants. At optimized reaction conditions, this double-wall chemistry enabled high water solubility through carboxylic acid functional groups introduced to the outer wall, while leaving the inner tube intact, as shown by Raman scattering and high resolution TEM. These outer wall selectively oxidized DWNTs retained electrical conductivity up to 65% better than thin films of similarly functionalized single-walled carbon nanotubes, which can be attributed to enhanced electrical percolation via the nonoxidized inner tubes.

  3. Water-Soluble NIR-Absorbing Rylene Chromophores for Selective Staining of Cellular Organelles.

    PubMed

    Kaloyanova, Stefka; Zagranyarski, Yulian; Ritz, Sandra; Hanulová, Mária; Koynov, Kaloian; Vonderheit, Andreas; Müllen, Klaus; Peneva, Kalina

    2016-03-01

    Biocompatible organic dyes emitting in the near-infrared are highly desirable in fluorescence imaging techniques. Herein we report a synthetic approach for building novel small peri-guanidine-fused naphthalene monoimide and perylene monoimide chromophores. The presented structures possess near-infrared absorption and emission, high photostability, and good water solubility. After a fast cellular uptake, they selectively stain mitochondria with a low background in live and fixed cells. They can be additionally modified in a one-step reaction with functional groups for covalent labeling of proteins. The low cytotoxicity allows a long time exposure of live cells to the dyes without the necessity of washing. Successful application in localization super-resolution microscopy was demonstrated in phosphate-buffered saline without any reducing or oxidizing additives. PMID:26891229

  4. Super fast detection of latent fingerprints with water soluble CdTe quantum dots.

    PubMed

    Cai, Kaiyang; Yang, Ruiqin; Wang, Yanji; Yu, Xuejiao; Liu, Jianjun

    2013-03-10

    A new method based on the use of highly fluorescent water-soluble cadmium telluride (CdTe) quantum dots (QDs) capped with mercaptosuccinic acid (MSA) was explored to develop latent fingerprints. After optimized the effectiveness of QDs method contains pH value and developing time, super fast detection was achieved. Excellent fingerprint images were obtained in 1-3s after immersed the latent fingerprints into quantum dots solution on various non-porous surfaces, i.e. adhesive tape, transparent tape, aluminum foil and stainless steel. High sensitivity of the new latent fingerprints develop method was obtained by developing the fingerprints pressed on aluminum foil successively with the same finger. Compared with methyl violet and rhodamine 6G, the MSA-CdTe QDs showed the higher develop speed and fingerprint image quality. Clear image can be maintained for months by extending exposure time of CCD camera, storing fingerprints in a low temperature condition and secondary development. PMID:23428349

  5. Dimethylformamide-mediated synthesis of water-soluble platinum nanodendrites for ethanol oxidation electrocatalysis.

    PubMed

    Mourdikoudis, Stefanos; Chirea, Mariana; Altantzis, Thomas; Pastoriza-Santos, Isabel; Pérez-Juste, Jorge; Silva, Fernando; Bals, Sara; Liz-Marzán, Luis M

    2013-06-01

    Herein we describe the synthesis of water-soluble platinum nanodendrites in dimethylformamide (DMF), in the presence of polyethyleneimine (PEI) as a stabilizing agent. The average size of the dendrites is in the range of 20-25 nm while their porosity can be tuned by modifying the concentration of the metal precursor. Electron tomography revealed different crystalline orientations of nanocrystallites in the nanodendrites and allowed a better understanding of their peculiar branching and porosity. The high surface area of the dendrites (up to 22 m(2) g(-1)) was confirmed by BET measurements, while X-ray diffraction confirmed the abundance of high-index facets in the face-centered-cubic crystal structure of Pt. The prepared nanodendrites exhibit excellent performance in the electrocatalytic oxidation of ethanol in alkaline solution. Sensing, selectivity, cycleability and great tolerance toward poisoning were demonstrated by cyclic voltammetry measurements. PMID:23613112

  6. Lysosomal ATP imaging in living cells by a water-soluble cationic polythiophene derivative.

    PubMed

    Huang, Bing-Huan; Geng, Zhi-Rong; Ma, Xiao-Yan; Zhang, Cui; Zhang, Zhi-Yang; Wang, Zhi-Lin

    2016-09-15

    Lysosomes in astrocytes and microglia can release ATP as the signaling molecule for the cells through ca(2+)-dependent exocytosis in response to various stimuli. At present, fluorescent probes that can detect ATP in lysosomes have not been reported. In this work, we have developed a new water-soluble cationic polythiophene derivative that can be specifically localized in lysosomes and can be utilized as a fluorescent probe to sense ATP in cells. PEMTEI exhibits high selectivity and sensitivity to ATP at physiological pH values and the detection limit of ATP is as low as 10(-11)M. The probe has low cytotoxicity, good permeability and high photostability in living cells and has been applied successfully to real-time monitoring of the change in concentrations of ATP in lysosomes though fluorescence microscopy. We also demonstrated that lysosomes in Hela cells can release ATP through Ca(2+)-dependent exocytosis in response to drug stimuli. PMID:27131993

  7. C-106 High-Level Waste Solids: Washing/Leaching and Solubility Versus Temperature Studies

    SciTech Connect

    GJ Lumetta; DJ Bates; PK Berry; JP Bramson; LP Darnell; OT Farmer III; LR Greenwood; FV Hoopes; RC Lettau; GF Piepel; CZ Soderquist; MJ Steele; RT Steele; MW Urie; JJ Wagner

    2000-01-26

    This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing and caustic leaching on the composition of the Hanford tank C-106 high-level waste (HLW) solids. The objective of this work was to determine the composition of the C-106 solids remaining after washing with 0.01M NaOH or leaching with 3M NaOH. Another objective of this test was to determine the solubility of various C-106 components as a function of temperature. The work was conducted according to test plan BNFL-TP-29953-8,Rev. 0, Determination of the Solubility of HLW Sludge Solids. The test went according to plan, with only minor deviations from the test plan. The deviations from the test plan are discussed in the experimental section.

  8. Water-soluble BODIPY-based fluorescent probe for mitochondrial imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Sui, Binglin; Tang, Simon; Woodward, Adam W.; Kim, Bosung; Belfield, Kevin D.

    2016-03-01

    A new mitochondrial targeting fluorescent probe is designed, synthesized, characterized, and investigated. The probe is composed of three moieties, a BODIPY platform working as the fluorophore, two triphenylphosphonium (TPP) groups serving as mitochondrial targeting moiety, and two long highly hydrophilic polyethylene glycol (PEG) chains to increase its water solubility and reduce its cytotoxicity. As a mitochondria-selective fluorescent probe, the probe exhibits a series of desirable advantages compared with other reported fluorescent mitochondrial probes. It is readily soluble in aqueous media and emits very strong fluorescence. Photophysical determination experiments show that the photophysical properties of the probe are independent of solvent polarity and it has high quantum yield in various solvents examined. The probe also has good photostability and pH insensitivity over a broad pH range. Results obtained from cell viability tests indicate that the cytotoxicity of the probe is very low. Confocal fluorescence microscopy colocalization experiments reveal that this probe possesses excellent mitochondrial targeting ability and it is suitable for imaging mitochondria in living cells.

  9. Physicochemical properties of a water soluble extracellular homopolysaccharide from Lactobacillus reuteri SK24.003.

    PubMed

    Miao, Ming; Ma, Yajun; Huang, Chao; Jiang, Bo; Cui, Steve W; Zhang, Tao

    2015-10-20

    A water soluble exopolysaccharide was obtained from Lactobacillus reuteri SK24.003 and its rheological and structural properties were investigated. The polysaccharide yield reached around 40.8g/L for 48h of fermentation. The purified exopolysaccharide was an α-d-glucan with the molecular weight of 2.50×10(7)g/mol. Thermal analysis showed the exopolysaccharide broke down above 200°C, the weight dramatically lost (around 53.0%) from 230 to 340°C and the melting point was 147.7°C with the enthalpy value of 78.4J/g. The glucan solution (3.0-9.0%, v/w) has an opalescent, milky-white color and the concentration affected the depth of color. The viscosity increased rapidly with concentration in the range of 3.0-20% (w/v) with relatively high viscosity as well as poor solubility at a concentration higher than 20% (w/v). The solution also exhibited the non-Newtonian pseudoplastic behavior with increasing shear rate from 0.01 to 100l/s. This glucan had a high viscosity in solution and this could make it suitable for usage as gum substitute in some processing food. PMID:26256197

  10. IUPAC-NIST Solubility Data Series. 96. Amines with Water Part 3. Non-Aliphatic Amines

    NASA Astrophysics Data System (ADS)

    Góral, Marian; Shaw, David G.; Mański, Andrzej; Wiśniewska-Gocłowska, Barbara; Oracz, Paweł

    2012-12-01

    The mutual solubilities and related liquid-liquid equilibria of 36 binary systems of non-aliphatic amines with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2010 are compiled. For 13 systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units.

  11. IUPAC-NIST Solubility Data Series. 93. Potassium Sulfate in Water

    NASA Astrophysics Data System (ADS)

    Eysseltová, Jitka; Bouaziz, Roger

    2012-03-01

    The solubility data for potassium sulfate in water are reviewed. All data were critically examined for their reliability. The best values were selected on the basis of critical evaluations and presented in tabular form. Fitting equations and plots are also provided. The quantities, units, and symbols used are in accord with IUPAC recommendations. The original data have been reported and, if necessary, transferred into the units and symbols recommended by IUPAC. The literature on solubility data was researched through 2010.

  12. First water-soluble backbone Ru-Ru-Ni heterometallic organometallic polymer.

    PubMed

    Scalambra, Franco; Serrano-Ruiz, Manuel; Romerosa, Antonio

    2015-04-01

    The water-soluble backbone heterometallic polymer {[(PTA)2 CpRu-μ-CN-RuCp(PTA)2 -μ-NiCl3 ]}n (2) is synthesized using a reproducible and robust method and fully characterized by X-ray single crystal diffraction. The Ru-Ru-Ni polymer is found to be stable in the solid state and soluble in water. Nuclear magnetic resonance (NMR) and light scattering studies show that the polymer is stable in water for several days in air. PMID:25739739

  13. Operation of the Oxide Washer for Water-Washing Solubles out of Impure Pu Oxide

    SciTech Connect

    Dodson, K E; Close, W L; Krikorian, O H; Summers III, H V

    2006-01-30

    An evaluation has been made for using the Oxide Washer to wash water-soluble materials out of impure Pu oxide. It is found that multiple washes are needed to reduce the water-soluble materials to very low levels in the impure Pu oxides. The removal of the wash water from the Oxide Washer is accompanied by particulates of the impure Pu oxide, which subsequently need to be filtered out. In spite of the additional filtration needed, the overall level of manpower required for processing is still only about one third of that for an all-manual operation.

  14. Preparation of amorphous solid dispersions by rotary evaporation and KinetiSol Dispersing: approaches to enhance solubility of a poorly water-soluble gum extract.

    PubMed

    Bennett, Ryan C; Brough, Chris; Miller, Dave A; O'Donnell, Kevin P; Keen, Justin M; Hughey, Justin R; Williams, Robert O; McGinity, James W

    2015-03-01

    Acetyl-11-keto-β-boswellic acid (AKBA), a gum resin extract, possesses poor water-solubility that limits bioavailability and a high melting point making it difficult to successfully process into solid dispersions by fusion methods. The purpose of this study was to investigate solvent and thermal processing techniques for the preparation of amorphous solid dispersions (ASDs) exhibiting enhanced solubility, dissolution rates and bioavailability. Solid dispersions were successfully produced by rotary evaporation (RE) and KinetiSol® Dispersing (KSD). Solid state and chemical characterization revealed that ASD with good potency and purity were produced by both RE and KSD. Results of the RE studies demonstrated that AQOAT®-LF, AQOAT®-MF, Eudragit® L100-55 and Soluplus with the incorporation of dioctyl sulfosuccinate sodium provided substantial solubility enhancement. Non-sink dissolution analysis showed enhanced dissolution properties for KSD-processed solid dispersions in comparison to RE-processed solid dispersions. Variances in release performance were identified when different particle size fractions of KSD samples were analyzed. Selected RE samples varying in particle surface morphologies were placed under storage and exhibited crystalline growth following solid-state stability analysis at 12 months in comparison to stored KSD samples confirming amorphous instability for RE products. In vivo analysis of KSD-processed solid dispersions revealed significantly enhanced AKBA absorption in comparison to the neat, active substance. PMID:24329130

  15. Novel branched poly(ethylenimine)-cholesterol water-soluble lipopolymers for gene delivery.

    PubMed

    Wang, Dong-an; Narang, Ajit S; Kotb, Malak; Gaber, A Osama; Miller, Duane D; Kim, Sung Wan; Mahato, Ram I

    2002-01-01

    A novel water-soluble lipopolymer was synthesized by linking cholesteryl chloroformate to the secondary amino groups of branched poly(ethylenimine) (PEI) of 1,800 and 10,000 Da. Conjugation through PEI secondary amines gives this newly synthesized lipopolymer (abbreviated as PEI-Chol) special advantage over our previously synthesized lipopolymers, which utilized the primary amino groups for conjugation, as the primary amino groups have a significant role in DNA condensation. Also, significantly, only one cholesterol molecule was grafted onto each PEI molecule (confirmed by (1)H NMR and MALDI-TOF mass spectrometry), leaving enough space for the steric interactions of the PEI's primary amines with the DNA. The PEI-Chol lipopolymer was characterized for the critical micellar concentration (cmc), buffer capacity, DNA condensation (by band retardation and circular dichroism), in vitro transfection efficiency, and cell viability. The cmcs of PEI-Chol 1,800 and PEI-Chol 10,000 were 496.6 and 1,330.5 microg/mL, respectively. The acid-base titration indicated high buffering capacity of the polymers around the pH range of 5-7, which indicated their potential for buffering in the acidic pH environment of the endosomes. The band retardation studies indicated that efficient condensation of the plasmid DNA could be achieved using these lipopolymers. The circular dichroism spectra indicated a change in DNA conformation and adoption of lower energy state upon condensation with these lipopolymers when an N/P ratio of 2.5/1 or above was formulated. The mean particle size of these complexes was in the range 110-205 nm, except for the complexes prepared using PEI of 1,800 Da, which had a mean particle size of 384 +/- 300 nm. The zeta potential of DNA complexes prepared using PEI-Chol 1,800, PEI-Chol 10,000 and PEI of 1,800, 10,000, and 25,000 Da at an N/P ratio of 15/1 was in the range 23-30 mV and was dependent on the N/P ratios. The in vitro transfection of PEI

  16. REMOVING WATER-SOLUBLE HAZARDOUS MATERIAL SPILLS FROM WATERWAYS WITH CARBON

    EPA Science Inventory

    A model for the removal of water-soluble organic materials from water by carbon-filled, buoyant packets and panels is described. Based on this model, equations are derived for the removal of dissolved organic compounds from waterways by buoyant packets that are either (a) cycled ...

  17. Water-soluble carbon nanotube compositions for drug delivery and medicinal applications

    DOEpatents

    Tour, James M.; Lucente-Schultz, Rebecca; Leonard, Ashley; Kosynkin, Dmitry V.; Price, Brandi Katherine; Hudson, Jared L.; Conyers, Jr., Jodie L.; Moore, Valerie C.; Casscells, S. Ward; Myers, Jeffrey N.; Milas, Zvonimir L.; Mason, Kathy A.; Milas, Luka

    2014-07-22

    Compositions comprising a plurality of functionalized carbon nanotubes and at least one type of payload molecule are provided herein. The compositions are soluble in water and PBS in some embodiments. In certain embodiments, the payload molecules are insoluble in water. Methods are described for making the compositions and administering the compositions. An extended release formulation for paclitaxel utilizing functionalized carbon nanotubes is also described.

  18. Aqueous coating dispersion (pseudolatex) of zein improves formulation of sustained-release tablets containing very water-soluble drug.

    PubMed

    Li, X N; Guo, H X; Heinamaki, J

    2010-05-01

    Zein is an alcohol soluble protein of corn origin that exhibits hydrophobic properties. Pseudolatexes are colloidal dispersions containing spherical solid or semisolid particles less than 1 microm in diameter and can be prepared from any existing thermoplastic water-insoluble polymer. The novel plasticized film-coating pseudolatex of zein was studied in formulation of sustained-release tablets containing very water-soluble drug. Film formation of plasticized aqueous dispersion was compared with film forming properties of plasticized organic solvent system (ethanol) of zein. The water vapor permeability (WVP), water uptake and erosion, and moisture sorption were evaluated with free films. The tablets containing metoprolol tartrate as a model drug were used in pan-coating experiments. Aqueous film coatings plasticized with PEG 400 exhibited very low water uptake. No significant difference in WVP, moisture sorption and erosion were found between aqueous films and organic solvent-based films of zein plasticized with PEG 400. The atomic force microscopy (AFM) images on microstructure of films showed that colloidal particle size of zein in the aqueous films was smaller than that observed in the solvent-based films. In addition, the aqueous-based films were more compact and smoother than the respective solvent-based films. The aqueous zein-coated tablets containing very water-soluble drug (metoprolol tartrate) exhibited clear sustained-release dissolution profiles in vitro, while the respective solvent-based film-coated tablets showed much faster drug release. Furthermore, aqueous zein-coated tablets had lower water absorption at high humidity conditions. In conclusion, the plasticized aqueous dispersion (pseudolatex) of zein can be used for moisture resistant film coating of sustained-release tablets containing very water-soluble drug. PMID:20129615

  19. Long-term observation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Handa, Daishi; Somada, Yuka; Ijyu, Moriaki; Azechi, Sotaro; Nakaema, Fumiya; Arakaki, Takemitsu; Tanahara, Akira

    2010-05-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the long-range transported air pollution from Asian continent has gained a special attention in Japan because of increase in photochemical oxidants in relatively remote islands. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) in the bulk aerosols collected at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We will report water-soluble chemical components data of anions, cations and DOC in bulk atmospheric aerosols collected at CHAAMS during August, 2005 to April, 2010. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions. In addition, we calculated background concentration of water-soluble chemical components at Okinawa

  20. Phase transfer of hydrophobic QDs for water-soluble and biocompatible nature through silanization

    SciTech Connect

    Yang, Ping; Zhou, Guangjun

    2011-12-15

    Graphical abstract: A facile and novel method has been developed for creating water-soluble and biocompatible CdSe/ZnS quantum dots with a small hydrodynamic diameter (less than 10 nm) via silanization. Highlights: Black-Right-Pointing-Pointer A facile and novel method has been developed for creating water-soluble and biocompatible CdSe/ZnS quantum dots (QDs) with a small hydrodynamic diameter (less than 10 nm). Black-Right-Pointing-Pointer The control of ligand exchange plays an important role to retain high fluorescence quantum yields. Black-Right-Pointing-Pointer The functional SiO{sub 2}-coated QDs were conjugated with immunoglobin G antibody by using biotin-streptavidin as linkers. Black-Right-Pointing-Pointer The QD phase transfer by silanization is a well-established method for generating biocompatible QDs. -- Abstract: A novel method has been developed for creating water-soluble and biocompatible CdSe/ZnS quantum dots (QDs) with a small hydrodynamic diameter (less than 10 nm). The silanization of the QDs was carried out by using partially hydrolyzed tetraethyl orthosilicate (TEOS) to replace organic ammine or tri-n-octylphosphine oxide on the surface of the QDs. The partially hydrolyzed 3-mercaptopropyltrimethoxysilane attached to the hydrolyzed TEOS layer on the QDs prevented the QDs from agglomeration when the QDs were transferred into water. The functional SiO{sub 2}-coated QDs were conjugated with immunoglobin G antibody by using biotin-streptavidin as linkers. The SiO{sub 2}-coated QDs exhibited the same absorption and photoluminescence (PL) spectra as those of initial QDs in organic solvents. The SiO{sub 2}-coated QDs preserved PL intensities, is colloidally stable over a wide pH range (pH 6-11). Because the mean diameter of amphiphilic polymer-coated QDs was almost 2 times of that of functional SiO{sub 2}-coated QDs, the QD phase transfer by silanization is a well-established method for generating biocompatible QDs.

  1. Water Soluble Vitamin E Administration in Wistar Rats with Non-alcoholic Fatty Liver Disease

    PubMed Central

    Tzanetakou, Irene P; Doulamis, Ilias P; Korou, Laskarina-Maria; Agrogiannis, George; Vlachos, Ioannis S; Pantopoulou, Alkisti; Mikhailidis, Dimitri P; Patsouris, Efstratios; Vlachos, Ioannis; Perrea, Despina N

    2012-01-01

    Objective: A diet rich in fat is associated with hepatic fat deposition [steatosis; non-alcoholic fatty liver disease (NAFLD)]. The exact cause of NAFLD however, is still unknown. The aim of this study was to assess the effect of a water-soluble formulation of vitamin E on a dietary-induced-NAFLD animal model. Methods: Adult male Wistar rats (n=20) were allocated to 2 groups: Controls (Group A, n=6), which received a standard chow diet for 24 weeks and a High Cholesterol group (HC: n=14), which received a standard chow diet enriched with cholesterol for the first 14 weeks of the experiment (t1). At t1, the HC group was divided into: Group HC(B), which received a high-saturated-fat/high-cholesterol (HSF/HCH) diet and Group HC(C), which followed the same HSF/HCH diet but was also administered water soluble vitamin E (10 IU/kg body weight/day), for 10 more weeks. Results: At the end of the study, group HC(C) exhibited significantly lower mean total cholesterol (T-CHOL) than group HC(B) (p<0.001). No significant differences were observed between HC(C) and Control groups in blood glucose and serum lipid concentrations. Liver Function Tests did not vary between all groups at the end of the study. Animals in group HC(B) exhibited higher SGOT at the end of the study compared with the beginning of the study (p<0.05). Group HC(B) exhibited the highest scores in steatosis, and grading (according to the NAFLD scoring system) in the histopathological analysis (p≤0.001 in all cases). Conclusions: Vitamin E seems to exert a hypolipidemic and hepatoprotective role in the presence of a HSF/HCH atherogenic diet in a rat model. PMID:22930662

  2. Solid dispersion as an approach for bioavailability enhancement of poorly water-soluble drug ritonavir.

    PubMed

    Sinha, Shilpi; Ali, Mushir; Baboota, Sanjula; Ahuja, Alka; Kumar, Anil; Ali, Javed

    2010-06-01

    Ritonavir is an antiretroviral drug characterized by low solubility and high permeability which corresponds to BCS class II drug. The purpose of the study was to develop solid dispersion by different methods and investigate them for in vitro and in vivo performance for enhancing dissolution and bioavailability, respectively. Since the drug possesses food-related absorption, the effect of biorelevant media (FaSSIF and FeSSIF state) on dissolution behavior was also studied. The solid dispersion was prepared using Gelucire as carrier in 1:4 ratio by different methods and were characterized for differential scanning calorimetry (DSC), X-ray diffractometry, scanning electron microscopy, and FT-IR. Oral bioavailability of 10 mg of ritonavir in solid dispersion prepared by solvent evaporation (SE1) and melt method (MM1) was compared with pure drug after oral administration of solid dispersion and pure drug to Albino Wistar rats of either sex. The results suggested formation of eutectic solid dispersion. In vitro dissolution studies was performed in 0.1 N HCl and biorelevant media showed enhanced dissolution rate as compared to pure drug in both FeSSIF media and 0.1 N HCl. The apparent rate of absorption of ritonavir from SE1 (C(max) 20221.37 ng/ml, t(max) 0.5 h) was higher than that of MM1 (C(max) 2,462.2, t(max) 1 h) and pure drug (C(max) 1,354.8 ng/ml, t(max) 0.5 h). On the basis of the result obtained, it was concluded that solid dispersion is a good approach to enhance solubility and bioavailability of poorly water-soluble ritonavir. PMID:20238187

  3. In vitro delivery of a sparingly water soluble compound from PLA50 microparticles.

    PubMed

    Mallard, C; Coudane, J; Rault, I; Vert, M

    2000-01-01

    The administration of a sparingly soluble drug is always problematic, especially when the drug has to be released from the degradable matrix of a polymeric drug delivery system. Attempts were made to achieve the complete release of 1-[2-(fluorobenzoyl) aminoethyl]-4-(7-methoxynaphtyl)piperazine (FAMP), a potential anxiolytic and antidepressor hydrophobic compound, from racemic poly(lactic acid) (PLA50)-based microparticles, 100% release was required at a low rate in order to allow monthly repeated S.C. or I.M. injections of this potent compound. FAMP-polymer combinations were made in the form of microspheres by the solvent evaporation technique. Release profiles were investigated under dynamic conditions by using a constant flow rate of pH 7.4 0.15 M phosphate buffer, used as a model of body fluids. Under these conditions, none of the microsphere compositions led to total release within a month, even when hydrophilic excipients, namely fructose and PEG were added. PLA50-FAMP microparticles with compositions and sizes similar to those of the microspheres, were then made by direct blending in dichloromethane, evaporation of the solvent, grinding and sieving. These formulations also failed in providing total drug release within 30 days, even at a high drug load. FAMP/PLA50/water-soluble additive, ternary grounded particles were finally prepared with fructose, PLA50 oligomers or poly(ethylene glycol) (PEG) as the additive. Only PLA50 grounded particles with percolating FAMP-PEG microdomains allowed 100% release of FAMP over a 30 day period, at a quasi constant rate which depended primarily on solubility and channelling provided the flow was slow enough. Data are discussed in terms of the accessibility of the entrapped drug to the aqueous medium. PMID:10670937

  4. Carbon turnover in the water-soluble protein of the adult human lens

    PubMed Central

    Stewart, Daniel N.; Lango, Jozsef; Nambiar, Krishnan P.; Falso, Miranda J. S.; FitzGerald, Paul G.; Rocke, David M.; Hammock, Bruce D.

    2013-01-01

    Purpose Human eye lenses contain cells that persist from embryonic development. These unique, highly specialized fiber cells located at the core (nucleus) of the lens undergo pseudo-apoptosis to become devoid of cell nuclei and most organelles. Ostensibly lacking in protein transcriptional capabilities, it is currently believed that these nuclear fiber cells owe their extreme longevity to the perseverance of highly stable and densely packed crystallin proteins. Maintaining the structural and functional integrity of lenticular proteins is necessary to sustain cellular transparency and proper vision, yet the means by which the lens actually copes with a lifetime of oxidative stress, seemingly without any capacity for protein turnover and repair, is not completely understood. Although many years of research have been predicated upon the assumption that there is no protein turnover or renewal in nuclear fiber cells, we investigated whether or not different protein fractions possess protein of different ages by using the 14C bomb pulse. Methods Adult human lenses were concentrically dissected by gently removing the cell layers in water or shaving to the nucleus with a curved micrometer-controlled blade. The cells were lysed, and the proteins were separated into water-soluble and water-insoluble fractions. The small molecules were removed using 3 kDa spin filters. The 14C/C was measured in paired protein fractions by accelerator mass spectrometry, and an average age for the material within the sample was assigned using the 14C bomb pulse. Results The water-insoluble fractions possessed 14C/C ratios consistent with the age of the cells. In all cases, the water-soluble fractions contained carbon that was younger than the paired water-insoluble fraction. Conclusions As the first direct evidence of carbon turnover in protein from adult human nuclear fiber cells, this discovery supports the emerging view of the lens nucleus as a dynamic system capable of maintaining

  5. Miktoarm star polymer based multifunctional traceable nanocarriers for efficient delivery of poorly water soluble pharmacological agents.

    PubMed

    Soliman, Ghareb M; Redon, Rocio; Sharma, Anjali; Mejía, Diana; Maysinger, Dusica; Kakkar, Ashok

    2014-09-01

    A versatile methodology to develop an inherently fluorescent and thus traceable multifunctional nanodelivery platform based on miktoarm polymers is reported. Miktoarm stars containing covalently linked tetraiodofluorescein dye, polyethylene glycol, and polycaprolactone self-assemble into micelles, and integrate multiple functions including fluorescent tags for imaging, a hydrophobic core for drug incorporation, and a hydrophilic corona for micelle stabilization. Curcumin, a pleiotropic but very poorly water-soluble drug, is loaded into these micelles with an efficiency of 25-60 wt%. It leads to a 25 000-fold increase in its aqueous solubility, and a sustained release over a period of 7 d. These micelles are rapidly internalized into murine J774A.1 macrophages, and accumulated into discrete cellular compartments, whereas the free and physically encapsulated dye is diffused in the cytoplasm. Curcumin-loaded micelles reduce lipopolysaccharide-induced nitric oxide release. The studies establish miktoarm star based nanocarriers as highly efficient in tracking their fate and expanding the scope of pharmacological agents with limited utility in experimental medicine. PMID:24903981

  6. Water soluble biocompatible vesicles based on polysaccharides and oligosaccharides inclusion complexes for carotenoid delivery.

    PubMed

    Polyakov, Nikolay E; Kispert, Lowell D

    2015-09-01

    Since carotenoids are highly hydrophobic, air- and light-sensitive hydrocarbon compounds, developing methods for increasing their bioavailability and stability towards irradiation and reactive oxygen species is an important goal. Application of inclusion complexes of "host-guest" type with polysaccharides and oligosaccharides such as arabinogalactan, cyclodextrins and glycyrrhizin minimizes the disadvantages of carotenoids when these compounds are used in food processing (colors and antioxidant capacity) as well as for production of therapeutic formulations. Cyclodextrin complexes which have been used demonstrated enhanced storage stability but suffered from poor solubility. Polysaccharide and oligosaccharide based inclusion complexes play an important role in pharmacology by providing increased solubility and stability of lipophilic drugs. In addition they are used as drug delivery systems to increase absorption rate and bioavailability of the drugs. In this review we summarize the existing data on preparation methods, analysis, and chemical reactivity of carotenoids in inclusion complexes with cyclodextrin, arabinogalactan and glycyrrhizin. It was demonstrated that incorporation of carotenoids into the "host" macromolecule results in significant changes in their physical and chemical properties. In particular, polysaccharide complexes show enhanced photostability of carotenoids in water solutions. A significant decrease in the reactivity towards metal ions and reactive oxygen species in solution was also detected. PMID:26005157

  7. Evaluation of kinetic parameters for water soluble crystals by thermo gravimetric analysis

    NASA Astrophysics Data System (ADS)

    Rama, S.; Surendra Dilip, C.; Perumal, Rajesh Narayana

    2015-01-01

    This work elevates the relevance of kinetic parameters of nucleation and thermal decomposition for water soluble crystals. The positive soluble Potassium Dihydrogen Phosphate (KDP) and negative soluble Lithium Sulfate Monohydrate (LSMH) materials were chosen for the kinetic evaluation. The results obtained from the classical nucleation theory are verified with the kinetic parameters which are evaluated from thermo gravimetric analysis. Nucleation parameters of a crystallization process such as interfacial energy (σ), volume free energy (ΔGv), critical energy barrier for nucleation (ΔG*), radius of the critical nucleus (r*) and nucleation rate (J) of the positive (KDP) and negative solubility (LSMH) crystals are determined from the classical nucleation theory of solubility-enthalpy relation. The kinetic parameters viz. the order of reaction, enthalpy, Gibbs free energy of activation, frequency factor, and entropy of activation are obtained from the TG based models viz. Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova. The effect of varying temperature with relative variation on Gibbs free energy for both positive and negative solubility crystals is also discussed. The developed model holds good for both positive and negative solubility crystals.

  8. Coaxial electrospinning for encapsulation and controlled release of fragile water-soluble bioactive agents.

    PubMed

    Jiang, Hongliang; Wang, Liqun; Zhu, Kangjie

    2014-11-10

    Coaxial electrospinning is a robust technique for one-step encapsulation of fragile, water-soluble bioactive agents, including growth factors, DNA and even living organisms, into core-shell nanofibers. The coaxial electrospinning process eliminates the damaging effects due to direct contact of the agents with organic solvents or harsh conditions during emulsification. The shell layer serves as a barrier to prevent the premature release of the water-soluble core contents. By varying the structure and composition of the nanofibers, it is possible to precisely modulate the release of the encapsulated agents. Promising work has been done with coaxially electrospun non-woven mats integrated with bioactive agents for use in tissue engineering, in local delivery and in wound healing, etc. This paper reviews the origins of the coaxial electrospinning method, its updated status and potential future developments for controlled release of the class of fragile, water-soluble bioactive agents. PMID:24780265

  9. Effect of supplementation of water-soluble vitamins on oxidative stress and blood pressure in prehypertensives.

    PubMed

    Talikoti, Prashanth; Bobby, Zachariah; Hamide, Abdoul

    2015-01-01

    The objective of the study was to evaluate the effect of water-soluble vitamins on oxidative stress and blood pressure in prehypertensives. Sixty prehypertensives were recruited and randomized into 2 groups of 30 each. One group received water-soluble vitamins and the other placebo for 4 months. Further increase in blood pressure was not observed in the vitamin group which increased significantly in the placebo group at the end of 4 months. Malonedialdehyde and protein carbonylation were reduced during the course of treatment with vitamins whereas in the placebo group there was an increase in the level of malondialdehyde. In conclusion, supplementation of water-soluble vitamins in prehypertension reduces oxidative stress and its progression to hypertension. PMID:25588130

  10. Effect of addition of water-soluble chitin on amylose film.

    PubMed

    Suzuki, Shiho; Shimahashi, Katsumasa; Takahara, Junichi; Sunako, Michihiro; Takaha, Takeshi; Ogawa, Kozo; Kitamura, Shinichi

    2005-01-01

    Amylose films blended with chitosan, which were free from additives such as acid, salt, and plasticizer, were prepared by casting mixtures of an aqueous solution of an enzymatically synthesized amylose and that of water-soluble chitin (44.1% deacetylated). The presence of a small amount of chitin (less than 10%) increased significantly the permeability of gases (N2, O2, CO2, C2H4) and improved the mechanical parameters of amylose film; particularly, the elastic modulus and elongation of the blend films were larger than those of amylose or chitin films. No antibacterial activity was observed with either amylose or water-soluble chitin films. But amylose films having a small amount of chitin showed strong antibacterial action, suggesting a morphological change in water-soluble chitin on the film surface by blending with amylose molecule. These facts suggested the presence of a molecular complex of amylose and chitosan. PMID:16283751

  11. Water-soluble NHC-Cu catalysts: applications in click chemistry, bioconjugation and mechanistic analysis.

    PubMed

    Díaz Velázquez, Heriberto; Ruiz García, Yara; Vandichel, Matthias; Madder, Annemieke; Verpoort, Francis

    2014-12-14

    Copper(I)-catalyzed 1,3-dipolar cycloaddition of azides and terminal alkynes (CuAAC), better known as "click" reaction, has triggered the use of 1,2,3-triazoles in bioconjugation, drug discovery, materials science and combinatorial chemistry. Here we report a new series of water-soluble catalysts based on N-heterocyclic carbene (NHC)-Cu complexes which are additionally functionalized with a sulfonate group. The complexes show superior activity towards CuAAC reactions and display a high versatility, enabling the production of triazoles with different substitution patterns. Additionally, successful application of these complexes in bioconjugation using unprotected peptides acting as DNA binding domains was achieved for the first time. Mechanistic insight into the reaction mechanism is obtained by means of state-of-the-art first principles calculations. PMID:25251642

  12. Water-soluble Hantzsch ester as switch-on fluorescent probe for efficiently detecting nitric oxide.

    PubMed

    Wang, Hui-Li; Liu, Fu-Tao; Ding, Ai-Xiang; Ma, Su-Fang; He, Lan; Lin, Lan; Lu, Zhong-Lin

    2016-12-01

    A water soluble Hantzsch ester derivative of coumarin, DHPS, was synthesized and successfully applied in the fluorescent sensing nitric oxide (NO) in aqueous solution. The fluorescence of probe DHPS is extremely weak, while its fluorescence was greatly switched on upon the addition of NO solution and showed high selectivity and sensitivity to NO. The limitation of the detection was calculated to be 18nM. The NO-induced aromatization of dihydropyridine in DHPS to pyridine derivative (PYS) proved to be the switching mechanism for the fluorescent sensing process, which was confirmed through spectra characterization and computation study. Cytotoxicity assay demonstrated both DHPS and PYS are biocompatible, the DHPS was successfully applied to track the endogenously produced NO in the RAW 264.7 cells. PMID:27299481

  13. Making water-soluble integral membrane proteins in vivo using an amphipathic protein fusion strategy

    PubMed Central

    Mizrachi, Dario; Chen, Yujie; Liu, Jiayan; Peng, Hwei-Ming; Ke, Ailong; Pollack, Lois; Turner, Raymond J.; Auchus, Richard J.; DeLisa, Matthew P.

    2015-01-01

    Integral membrane proteins (IMPs) play crucial roles in all cells and represent attractive pharmacological targets. However, functional and structural studies of IMPs are hindered by their hydrophobic nature and the fact that they are generally unstable following extraction from their native membrane environment using detergents. Here we devise a general strategy for in vivo solubilization of IMPs in structurally relevant conformations without the need for detergents or mutations to the IMP itself, as an alternative to extraction and in vitro solubilization. This technique, called SIMPLEx (solubilization of IMPs with high levels of expression), allows the direct expression of soluble products in living cells by simply fusing an IMP target with truncated apolipoprotein A-I, which serves as an amphipathic proteic ‘shield' that sequesters the IMP from water and promotes its solubilization. PMID:25851941

  14. Materials and fabrication sequences for water soluble silicon integrated circuits at the 90 nm node

    NASA Astrophysics Data System (ADS)

    Yin, Lan; Bozler, Carl; Harburg, Daniel V.; Omenetto, Fiorenzo; Rogers, John A.

    2015-01-01

    Tungsten interconnects in silicon integrated circuits built at the 90 nm node with releasable configurations on silicon on insulator wafers serve as the basis for advanced forms of water-soluble electronics. These physically transient systems have potential uses in applications that range from temporary biomedical implants to zero-waste environmental sensors. Systematic experimental studies and modeling efforts reveal essential aspects of electrical performance in field effect transistors and complementary ring oscillators with as many as 499 stages. Accelerated tests reveal timescales for dissolution of the various constituent materials, including tungsten, silicon, and silicon dioxide. The results demonstrate that silicon complementary metal-oxide-semiconductor circuits formed with tungsten interconnects in foundry-compatible fabrication processes can serve as a path to high performance, mass-produced transient electronic systems.

  15. Making water-soluble integral membrane proteins in vivo using an amphipathic protein fusion strategy.

    PubMed

    Mizrachi, Dario; Chen, Yujie; Liu, Jiayan; Peng, Hwei-Ming; Ke, Ailong; Pollack, Lois; Turner, Raymond J; Auchus, Richard J; DeLisa, Matthew P

    2015-01-01

    Integral membrane proteins (IMPs) play crucial roles in all cells and represent attractive pharmacological targets. However, functional and structural studies of IMPs are hindered by their hydrophobic nature and the fact that they are generally unstable following extraction from their native membrane environment using detergents. Here we devise a general strategy for in vivo solubilization of IMPs in structurally relevant conformations without the need for detergents or mutations to the IMP itself, as an alternative to extraction and in vitro solubilization. This technique, called SIMPLEx (solubilization of IMPs with high levels of expression), allows the direct expression of soluble products in living cells by simply fusing an IMP target with truncated apolipoprotein A-I, which serves as an amphipathic proteic 'shield' that sequesters the IMP from water and promotes its solubilization. PMID:25851941

  16. Water-Soluble Iridium-NHC-Phosphine Complexes as Catalysts for Chemical Hydrogen Batteries Based on Formate.

    PubMed

    Horváth, Henrietta; Papp, Gábor; Szabolcsi, Roland; Kathó, Ágnes; Joó, Ferenc

    2015-09-21

    Molecular hydrogen, obtained by water electrolysis or photocatalytic water splitting, can be used to store energy obtained from intermittent sources such as wind and solar power. The storage and safe transportation of H2 , however, is an open and central question in such a hydrogen economy. Easy-to-synthesize, water-soluble iridium-N-heterocyclic carbene-phosphine (Ir(I) -NHC-phosphine) catalysts show unprecedented high catalytic activity in dehydrogenation of aqueous sodium formate. Fast reversible generation and storage of hydrogen can be achieved with these catalysts by a simple decrease or increase in the hydrogen pressure, respectively. PMID:26289830

  17. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities.

    PubMed

    Kurnia, Kiki A; Sintra, Tânia E; Neves, Catarina M S S; Shimizu, Karina; Canongia Lopes, José N; Gonçalves, Fernando; Ventura, Sónia P M; Freire, Mara G; Santos, Luís M N B F; Coutinho, João A P

    2014-10-01

    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs. PMID:25119425

  18. Intestinal absorption of water-soluble vitamins in health and disease

    PubMed Central

    Said, Hamid M.

    2014-01-01

    Our knowledge of the mechanisms and regulation of intestinal absorption of water-soluble vitamins under normal physiological conditions, and of the factors/conditions that affect and interfere with theses processes has been significantly expanded in recent years as a result of the availability of a host of valuable molecular/cellular tools. Although structurally and functionally unrelated, the water-soluble vitamins share the feature of being essential for normal cellular functions, growth and development, and that their deficiency leads to a variety of clinical abnormalities that range from anaemia to growth retardation and neurological disorders. Humans cannot synthesize water-soluble vitamins (with the exception of some endogenous synthesis of niacin) and must obtain these micronutrients from exogenous sources. Thus body homoeostasis of these micronutrients depends on their normal absorption in the intestine. Interference with absorption, which occurs in a variety of conditions (e.g. congenital defects in the digestive or absorptive system, intestinal disease/resection, drug interaction and chronic alcohol use), leads to the development of deficiency (and sub-optimal status) and results in clinical abnormalities. It is well established now that intestinal absorption of the water-soluble vitamins ascorbate, biotin, folate, niacin, pantothenic acid, pyridoxine, riboflavin and thiamin is via specific carrier-mediated processes. These processes are regulated by a variety of factors and conditions, and the regulation involves transcriptional and/or post-transcriptional mechanisms. Also well recognized now is the fact that the large intestine possesses specific and efficient uptake systems to absorb a number of water-soluble vitamins that are synthesized by the normal microflora. This source may contribute to total body vitamin nutrition, and especially towards the cellular nutrition and health of the local colonocytes. The present review aims to outline our current

  19. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities

    PubMed Central

    Kurnia, Kiki A.; Sintra, Tânia E.; Neves, Catarina M. S. S.; Shimizu, Karina; Lopes, José N. Canongia; Gonçalves, Fernando; Ventura, Sónia P. M.; Freire, Mara G.; Santos, Luís M. N. B. F.; Coutinho, João A. P.

    2014-01-01

    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs. PMID:25119425

  20. Water soluble cyclosporine monomethoxy poly(ethyleneglycol) conjugates as potential prodrugs.

    PubMed

    Cho, Hoon; Chung, Yongseog

    2004-06-01

    The highly water-soluble monomethoxypoly(ethyleneglycol) (mPEG) prodrugs of cyclosporin A (CsA) were synthesized. These prodrugs were prepared by initially preparing intermediate in the form of carbonate at the 3'-positions of CsA with chloromethyl chloroformate, in the presence of a base to provide a 3'-carbonated CsA intermediate. Reaction of the CsA intermediate with mPEG derivative in the presence of a base provides the desired water-soluble prodrugs. As a model, we chose molecular weight 5 kDa mPEG in the reaction with CsA to give water soluble prodrugs. To prove that the prodrug is decomposed in the body to produce CsA, the enzymatic hydrolysis test was conducted using human liver homogenate at 37 degrees C. The prodrug was decomposed in human liver homogenate to produce the active material, CsA, and the hydrolysis half-life (t(1/2)) of the prodrug, KI-306 was 2.2 minutes at 37 degrees C. However, a demonstration of non-enzymatic conversion in pH 7.4 phosphate buffer was provided by the fact that the half-life (t(1/2)) is 21 hours at 37 degrees C. The hydrolysis test in rat whole blood was also conducted. The hydrolysis was seen with half-life (t(1/2)) of about 9.9, 65.0, 14.2, 3.4, 2.1 9.5, and 1.6 minutes for KI-306, 309, 312, 313, 315, 316, and 317, respectively. This is the ideal for CsA prodrug. The pharmacokinetic study of the prodrug, KI-306, in comparison to the commercial product (Sandimmune Neoral Solution) was also carried out after single oral dose. Each rat received 7 mg/kg of CsA equivalent dose. Especially, the prodrug KI-306 exhibits higher AUC and Cmax than the conventional Neoral. The AUC and Cmax were increased nearly 1.5 fold. The kinetic value was also seen with Tmax of about 1.43 and 2.44 hours for KI-306 and Neoral, respectively. PMID:15283470

  1. Determination of the design space of the HPLC analysis of water-soluble vitamins.

    PubMed

    Wagdy, Hebatallah A; Hanafi, Rasha S; El-Nashar, Rasha M; Aboul-Enein, Hassan Y

    2013-06-01

    Analysis of water-soluble vitamins has been tremendously approached through the last decades. A multitude of HPLC methods have been reported with a variety of advantages/shortcomings, yet, the design space of HPLC analysis of these vitamins was not defined in any of these reports. As per the food and drug administration (FDA), implementing the quality by design approach for the analysis of commercially available mixtures is hypothesized to enhance the pharmaceutical industry via facilitating the process of analytical method development and approval. This work illustrates a multifactorial optimization of three measured plus seven calculated influential HPLC parameters on the analysis of a mixture containing seven common water-soluble vitamins (B1, B2, B6, B12, C, PABA, and PP). These three measured parameters are gradient time, temperature, and ternary eluent composition (B1/B2) and the seven calculated parameters are flow rate, column length, column internal diameter, dwell volume, extracolumn volume, %B (start), and %B (end). The design is based on 12 experiments in which, examining of the multifactorial effects of these 3 + 7 parameters on the critical resolution and selectivity, was carried out by systematical variation of all these parameters simultaneously. The 12 basic runs were based on two different gradient time each at two different temperatures, repeated at three different ternary eluent compositions (methanol or acetonitrile or a mixture of both). Multidimensional robust regions of high critical R(s) were defined and graphically verified. The optimum method was selected based on the best resolution separation in the shortest run time for a synthetic mixture, followed by application on two pharmaceutical preparations available in the market. The predicted retention times of all peaks were found to be in good match with the virtual ones. In conclusion, the presented report offers an accurate determination of the design space for critical resolution in the

  2. Cryptic clues as to how water-soluble protein toxins form pores in membranes.

    PubMed

    Parker, Michael W

    2003-07-01

    Pore-forming protein toxins possess the remarkable property that they can exist either in a stable water-soluble state or as an integral membrane pore. In order to convert from the water-soluble to the membrane state, the toxin must undergo large conformational changes. Recent work on a class of pore-forming toxins that are rich in beta-sheet content suggests a common mechanism of membrane insertion may exist despite these toxins possessing very different primary, tertiary and quaternary structures. PMID:12893054

  3. Determination of water-soluble ions in soils from the dry valleys of Antarctica

    NASA Technical Reports Server (NTRS)

    Bustin, R.

    1981-01-01

    The soil chemistry of the dry valleys of Antarctica was studied. These valleys furnish a terrestrial analog for the surface of Mars. The abundance of the water-soluble ions magnesium, calcium, potassium, sodium chloride, and nitrate in soil samples was determined. All samples examined contained water-soluble salts reflecting the aridity of the area. Movement of salts to low-lying areas was verified. Upward ionic migration was evident in all core samples. Of all cations observed, sodium showed the greatest degree of migration.

  4. Surfactant-assisted synthesis of water-soluble and biocompatible semiconductor quantum dot-micelles.

    SciTech Connect

    Brinker, C. Jeffrey; Bunge, Scott D.; Gabaldon, John; Fan, Hongyou; Scullin, Chessa; Leve, Erik W.; Wilson, Michael C.; Tallant, David Robert; Boyle, Timothy J.

    2005-04-01

    We report a simple, rapid approach to synthesize water-soluble and biocompatible fluorescent quantum dot (QD) micelles by encapsulation of monodisperse, hydrophobic QDs within surfactant/lipid micelles. Analyses of UV-vis and photo luminescence spectra, along with transmission electron microscopy, indicate that the water-soluble semiconductor QD micelles are monodisperse and retain the optical properties of the original hydrophobic QDs. The QD micelles were shown to be biocompatible and exhibited little or no aggregation when taken up by cultured rat hippocampal neurons.

  5. Understanding the impact of media viscosity on dissolution of a highly water soluble drug within a USP 2 mini vessel dissolution apparatus using an optical planar induced fluorescence (PLIF) method.

    PubMed

    Stamatopoulos, Konstantinos; Batchelor, Hannah K; Alberini, Federico; Ramsay, John; Simmons, Mark J H

    2015-11-10

    In this study, planar induced fluorescence (PLIF) was used for the first time to evaluate variability in drug dissolution data using Rhodamine-6G doped tablets within small volume USP 2 apparatus. The results were compared with tablets contained theophylline (THE) drug for conventional dissolution analysis. The impact of hydrodynamics, sampling point, dissolution media viscosity and pH were investigated to note effects on release of these two actives from the hydrophilic matrix tablets. As expected mixing performance was poor with complex and reduced velocities at the bottom of the vessel close to the tablet surface; this mixing became even worse as the viscosity of the fluid increased. The sampling point for dissolution can affect the results due to in-homogenous mixing within the vessel; this effect is exacerbated with higher viscosity dissolution fluids. The dissolution profiles of RH-6G measured via PLIF and THE measured using UV analysis were not statistically different demonstrating that RH-6G is an appropriate probe to mimic the release profile of a highly soluble drug. A linear correlation was accomplished between the release data of the drug and the dye (R(2)>0.9). The dissolution profile of the dye, obtained with the analysis of the PLIF images, can be used in order to evaluate how the viscosity and the mixing performance of USP 2 mini vessel affect the interpretation of the dissolution data of the targeted drug. PMID:26363111

  6. Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

    NASA Astrophysics Data System (ADS)

    Pradeep Kumar, P.; Broekhuizen, K.; Abbatt, J. P. D.

    2003-05-01

    The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids - oxalic, malonic and glutaric - match very closely Köhler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Köhler theory is to within 3nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Köhler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

  7. Changes in Water Sorption and Solubility of Dental Adhesive Systems after Cigarette Smoke

    PubMed Central

    Vitória, Lívia Andrade; Aguiar, Thaiane Rodrigues; Santos, Poliana Ramos Braga; Cavalcanti, Andrea Nóbrega

    2013-01-01

    Aim. To evaluate the effect of cigarette smoke on water sorption and solubility of four adhesive systems. Materials and Methods. Sixteen disks of each adhesive system were prepared (Adper Scotchbond Multipurpose Adhesive (SA); Adper Scotchbond Multipurpose Adhesive System (Adhesive + Primer) (SAP); Adper Single Bond Plus (SB); Adper Easy One (EO)). Specimens were desiccated until a constant mass was obtained and divided into two groups (n = 8). One-half of the specimens were immersed in deionized water, while the other half were also immersed, but with daily exposure to tobacco smoke. After 21 days, disks were measured again and stored in desiccators until constant mass was achieved. Data were calculated according to ISO specifications and statistically analyzed. Results. The tobacco smoke only significantly affected the water sorption and solubility of EO. There were significant differences in both analyses among materials tested. The SB exhibited the highest water sorption, followed by EO, which demonstrated significantly higher solubility values than SB. The SA and SAP showed low water sorption and solubility, and there were no significant differences between the two. Conclusion. Regardless of smoke exposure, both simplified adhesive systems presented an inferior performance that could be related to the complex mixture of components in such versions. PMID:23984078

  8. Grand canonical ensemble molecular dynamics simulation of water solubility in polyamide-6,6.

    PubMed

    Eslami, Hossein; Mehdipour, Nargess

    2011-01-14

    Grand canonical ensemble molecular dynamics simulation is employed to calculate the solubility of water in polyamide-6,6. It is shown that performing two separate simulations, one in the polymeric phase and one in the gaseous phase, is sufficient to find the phase coexistence point. In this method, the chemical potential of water in the polymer phase is expanded as a first-order Taylor series in terms of pressure. Knowing the chemical potential of water in the polymer phase in terms of pressure, another simulation for water in the gaseous phase, in the grand canonical ensemble, is done in which the target chemical potential is set in terms of pressure in the gas phase. The phase coexistence point can easily be calculated from the results of these two independent simulations. Our calculated sorption isotherms and solubility coefficients of water in polyamide-6,6, over a wide range of temperatures and pressures, agree with experimental data. PMID:21031194

  9. Diffusion and solubility of hydrogen and water in periclase

    NASA Astrophysics Data System (ADS)

    Joachim, Bastian; Wohlers, Anke; Norberg, Nicholas; Gardés, Emmanuel; Petrishcheva, Elena; Abart, Rainer

    2013-01-01

    Cylinders of synthetic periclase single crystals were annealed at 0.15-0.5 GPa and 900-1200 °C under water-saturated conditions for 45 min to 72 h. Infrared spectra measured on the quenched products show bands at 3,297 and 3,312 cm-1 indicating V {OH/-} centers (OH-defect stretching vibrations in a half-compensated cation vacancy) in the MgO structure as a result of proton diffusion into the crystal. For completely equilibrated specimens, the OH-defect concentration, expressed as H2O equivalent, was calculated to 3.5 wt ppm H2O at 1,200 °C and 0.5 GPa based on the calibration method of Libowitzky and Rossmann (Am Min 82:1111-1115, 1997). This value was confirmed via Raman spectroscopy, which shows OH-defect-related bands at identical wavenumbers and yields an H2O equivalent concentration of about 9 wt ppm using the quantification scheme of Thomas et al. (Am Min 93:1550-1557, 2008), revised by Mrosko et al. (Am Mineral 96:1748-1759, 2011). Results of both independent methods give an overall OH-defect concentration range of 3.5-9 (+4.5/-2.6) ppm H2O. Proton diffusion follows an Arrhenius law with an activation energy E a = 280 ± 64 kJ mol-1 and the logarithm of the pre-exponential factor logDo (m2 s-1) = -2.4 ± 1.9. IR spectra taken close to the rims of MgO crystals that were exposed to water-saturated conditions at 1,200 °C and 0.5 GPa for 24 h show an additional band at 3,697 cm-1, which is related to brucite precipitates. This may be explained by diffusion of molecular water into the periclase, and its reaction with the host crystal during quenching. Diffusion of molecular water may be described by logDH2O (m2 s-1) = -14.1 ± 0.4 (2σ) at 1,200 °C and 0.5 GPa, which is ~ 2 orders of magnitude slower than proton diffusion at identical P-T conditions.

  10. Dynamic Nuclear Polarization with a Water-soluble Rigid Biradical

    PubMed Central

    Kiesewetter, Matthew K.; Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.; Swager, Timothy M.

    2012-01-01

    A new biradical polarizing agent, bTbtk-py, for dynamic nuclear polarization (DNP) experiments in aqueous media is reported. The synthesis is discussed in light of the requirements of the optimum, theoretical, biradical system. To date, the DNP NMR signal enhancement resulting from bTbtk-py is the largest of any biradical in the ideal glycerol/water solvent matrix, ε = 230. EPR and X-ray crystallography are used to characterize the molecule and suggest approaches for further optimizing the biradical distance and relative orientation. PMID:22372769

  11. Metabolic behaviour of water-soluble fluorescent whitening agents in the rat and bean plant.

    PubMed

    Muecke, W; Dupuis, G; Esser, H O

    1975-01-01

    The behaviour of three representative water-soluble fluorescent whitening agents (FWAs) was studied in rats and bean plants using 14C-labelled compounds. Following oral doses of 5 mg/kg of each of the FWAs to rats, rapid and complete excretion of radioactive material was observed, with an excretion half life ranging from 7-13 hours. Faeces were practically the only route of excretion, indicating, in combination with the short half life times, that no significant amounts of whitener were absorbed from the digestive tract. No radioactive residues were found in blood, liver, kidney, brain, muscle, or fat 96 hours after dosing (limit of quantitative determination 0.005-0.01 ppm Fwa equivalents). Whereas, after application of compound (1) and compound (3), radioactive material was completely extractable from faeces in the form of unchanged parent compounds, that in the compound (2) experiments was not extractable. When bean plants (Phaseolus vulgaris) were grown in the presence of 14C-labelled compound (3) in nutrient solution (11.5 ppm) and in soil (,7.5 ppm), approximately 55% and 2% of the applied radioactive material, respectively, was absorbed by the plants. More than 90% of thie material was bound to the roots in both experiments 40 days after the application. Eight percent of the radioactive material absorbed in the soil experiment was translocated mainly into the stems whereas only trace amounts of the order of less than 0.1 ppm reached the leaves and bean pods. It is concluded from these experiments with extremely high concentrations of compound (3) that under the conditions which may occur in practice residues of water-soluble FWAs do not appear in substantial amounts in edible parts of crops. PMID:1064534

  12. New cytotoxic and water-soluble bis(2-phenylazopyridine)ruthenium(II) complexes.

    PubMed

    Hotze, Anna C G; Bacac, Marina; Velders, Aldrik H; Jansen, Bart A J; Kooijman, Huub; Spek, Anthony L; Haasnoot, Jaap G; Reedijk, Jan

    2003-04-24

    New water-soluble bis(2-phenylazopyridine)ruthenium(II) complexes, all derivatives of the highly cytotoxic alpha-[Ru(azpy)(2)Cl(2)] (alpha denoting the coordinating pairs Cl, N(py), and N(azo) as cis, trans, cis, respectively) have been developed. The compounds 1,1-cyclobutanedicarboxylatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(cbdca-O,O')] (1), oxalatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(ox)] (2), and malonatobis(2-phenylazopyridine)ruthenium(II), alpha-[Ru(azpy)(2)(mal)] (3), have been synthesized and fully characterized. X-ray analyses of 1 and 2 are reported, and compound 1 is the first example in which the cbdca ligand is coordinated to a ruthenium center. The cytotoxicity of this series of water-soluble bis(2-phenylazopyridine) complexes has been determined in A2780 human ovarian carcinoma and A2780cisR, the corresponding cisplatin-resistant cell line. For comparison reasons, the cytotoxicity of the complexes alpha-[Ru(azpy)(2)Cl(2)], alpha-[Ru(azpy)(2)(NO(3))(2)], beta-[Ru(azpy)(2)Cl(2)] (beta indicating the coordinating pairs Cl, N(py), and N(azo) as cis, cis, cis, respectively), and beta-[Ru(azpy)(2)(NO(3))(2)] have been determined in this cell line. All the bis(2-phenylazopyridine)ruthenium(II) compounds display a promising cytotoxicity in the A2780 cell line (IC(50) = 0.9-10 microM), with an activity comparable to that of cisplatin and even higher than the activity of carboplatin. Interestingly, the IC(50) values of this series of ruthenium compounds (except the beta isomeric compounds) are similar in the cisplatin-resistant A2780cisR cell line compared to the normal cell line A2780, suggesting that the activity of these compounds might not be influenced by the multifactorial resistance mechanism that affect platinum anticancer agents. PMID:12699392

  13. Selectivity differences of water-soluble vitamins separated on hydrophilic interaction stationary phases.

    PubMed

    Yang, Yuanzhong; Boysen, Reinhard I; Hearn, Milton T W

    2013-06-01

    In this study, the retention behavior and selectivity differences of water-soluble vitamins were evaluated with three types of polar stationary phases (i.e. an underivatized silica phase, an amide phase, and an amino phase) operated in the hydrophilic interaction chromatographic mode with ESI mass spectrometric detection. The effects of mobile phase composition, including buffer pH and concentration, on the retention and selectivity of the vitamins were investigated. In all stationary phases, the neutral or weakly charged vitamins exhibited very weak retention under each of the pH conditions, while the acidic and more basic vitamins showed diverse retention behaviors. With the underivatized silica phase, increasing the salt concentration of the mobile phase resulted in enhanced retention of the acidic vitamins, but decreased retention of the basic vitamins. These observations thus signify the involvement of secondary mechanisms, such as electrostatic interaction in the retention of these analytes. Under optimized conditions, a baseline separation of all vitamins was achieved with excellent peak efficiency. In addition, the effects of water content in the sample on retention and peak efficiency were examined, with sample stacking effects observed when the injected sample contained a high amount of water. PMID:23554360

  14. Luminescence temperature antiquenching of water-soluble CdTe quantum dots: role of the solvent.

    PubMed

    Wuister, Sander F; de Mello Donegá, Celso; Meijerink, Andries

    2004-08-25

    Luminescence temperature antiquenching (LTAQ) is observed for water-soluble CdTe quantum dots (QDs) capped with aminoethanethiol (AET). The efficient exciton emission (quantum efficiency of approximately 40% at 300 K) is quenched almost completely as the QD solutions are cooled to below 230 K and is fully recovered around 270 K upon warming up to room temperature (LTAQ). Temperature-dependent lifetime measurements show that the quenching rate is high, resulting in an on/off behavior. No LTAQ is observed for CdTe QDs capped with aminoundecanethiol (AUT). The LTAQ is explained by the influence of solvent freezing on the surface of the QD core. Freezing of the solvation water molecules surrounding the QD will induce strain in the capping shell, due to the interaction between water and the charged heads of the capping molecules. Short carbon chains (AET) will propagate the strain to the QD surface, creating surface quenching states, whereas long and flexible chains (AUT) will dissipate the strain, thus avoiding surface distortion. Freezing-point depression by the addition of methanol results in a lowering of the transition temperature. Additional support is provided by the size dependence of the LTAQ: smaller particles, with higher local ionic strength due to a higher density of charged NH(3)(+) surface groups, experience a lower transition temperature due to stronger local freezing-point depression. PMID:15315455

  15. Quantitative oral dosing of water soluble and lipophilic contaminants in the Japanese medaka (Oryzias latipes)

    SciTech Connect

    Schultz, Irv; Reed, Stacey M.; Pratt, Amanda V.; Skillman, Ann D.

    2007-02-01

    Quantitative oral dosing in fish can be challenging, particularly with water soluble contaminants, which can leach into the aquarium water prior to ingestion. We applied a method of bioencapsulation using newly hatched brine shrimp (Artemia franciscana) nauplii to study the toxicokinetics of five chlorinated and brominated halogenated acetic acids (HAAs), which are drinking water disinfection by-products. These results are compared to those obtained in a previous study using a polybrominated diphenyl ether (PBDE-47), a highly lipophilic chemical. The HAAs and PBDE-47 were bioencapsulated using freshly hatched A. franciscana nauplii after incubation in concentrated solutions of the study chemicals for 18 h. Aliquots of the brine shrimp were quantitatively removed for chemical analysis and fed to individual fish that were able to consume 400–500 nauplii in less than 5min. At select times after feeding, fish were euthanized and the HAA or PBDE-47 content determined. The absorption of HAAs was quantitatively similar to previous studies in rodents: rapid absorptionwith peak body levels occurringwithin 1–2 h, then rapidly declining with elimination half-life of 0.3–3 h depending on HAA. PBDE-47 was more slowly absorbed with peak levels occurring by 18 h and very slowly eliminated with an elimination half-life of 281 h.

  16. Structural Characterization and Reactivity of Pyrogenic Water-Soluble Organic Matter Derived from Biomass Combustion

    NASA Astrophysics Data System (ADS)

    Norwood, M. J.; Louchouarn, P.; Kuo, L.

    2011-12-01

    Combustion processes, whether from natural or anthropogenic origin, are major sources of particulate matter (PM), black carbon (BC), and volatile organic carbon to the atmosphere as well as soils and aquatic environments. The ubiquitous presence of biomass combustion by-products in atmospheric particles and soils could potentially lead to a large transfer of pyrogenic water-soluble organic matter (Pyr-WSOM) to the surface of watersheds and aquatic systems. In spite of this, there is a dearth of studies that have characterized the sources, and particularly the fate, of Pyr-WSOM to aquatic systems. In the present study, Pyr-WSOM was extracted from plant-derived chars (feedstocks: honey mesquite, cordgrass, and loblolly pine) produced at a range of temperatures (150-850C), and were then characterized using elemental analyses and ATR-FTIR. Low temperature (250C) Pyr-WSOM, extracted from honey mesquite and cordgrass biochars, were then incubated with aliquots of filtered water from the Trinity River (TX) for one month under dark conditions. Consistent with prior studies on combustion molecular markers such as anhydrosugars and methoxylated phenols, the total amount of dissolved organic carbon (DOC) released from biochars peaks around 200-250C and then decreases with increasing temperature of combustion. Elemental and structural analyses of biochar-derived WSOM reflect the selective solubility of certain functional groups. For example, despite the predominance of aromatic units and soot structures in biochars formed at high temperatures, such functionalities are not as predominant in their respective Pyr-WSOM. In addition, the high proportion of O-containing functionalities suggests that Pyr-WSOM may be more biodegradable than the particulate residues of biomass combustion. Indeed, low temperature Pyr-WSOM decomposed rapidly with half-lives ranging ~30 days for total DOC to 4-5 days for specific molecular markers of biomass combustion. These rapid turnover rates are in

  17. Single-mode lasing from colloidal water-soluble CdSe/CdS quantum dot-in-rods.

    PubMed

    Di Stasio, Francesco; Grim, Joel Q; Lesnyak, Vladimir; Rastogi, Prachi; Manna, Liberato; Moreels, Iwan; Krahne, Roman

    2015-03-18

    Core-shell CdSe/CdS nanocrystals are a very promising material for light emitting applications. Their solution-phase synthesis is based on surface-stabilizing ligands that make them soluble in organic solvents, like toluene or chloroform. However, solubility of these materials in water provides many advantages, such as additional process routes and easier handling. So far, solubilization of CdSe/CdS nanocrystals in water that avoids detrimental effects on the luminescent properties poses a major challenge. This work demonstrates how core-shell CdSe/CdS quantum dot-in-rods can be transferred into water using a ligand exchange method employing mercaptopropionic acid (MPA). Key to maintaining the light-emitting properties is an enlarged CdS rod diameter, which prevents potential surface defects formed during the ligand exchange from affecting the photophysics of the dot-in-rods. Films made from water-soluble dot-in-rods show amplified spontaneous emission (ASE) with a similar threshold (130 μJ/cm(2)) as the pristine material (115 μJ/cm(2)). To demonstrate feasibility for lasing applications, self-assembled microlasers are fabricated via the "coffee-ring effect" that display single-mode operation and a very low threshold of ∼10 μJ/cm(2). The performance of these microlasers is enhanced by the small size of MPA ligands, enabling a high packing density of the dot-in-rods. PMID:25335769

  18. Maltotriose-conjugation to a fluorinated chlorin derivative generating a PDT photosensitizer with improved water-solubility.

    PubMed

    Narumi, Atsushi; Tsuji, Takahiro; Shinohara, Kosuke; Yamazaki, Hiromi; Kikuchi, Moriya; Kawaguchi, Seigou; Mae, Tomoya; Ikeda, Atsushi; Sakai, Yuichi; Kataoka, Hiromi; Inoue, Masahiro; Nomoto, Akihiro; Kikuchi, Jun-ichi; Yano, Shigenobu

    2016-04-14

    Photoactive molecules with the frameworks of chlorin and/or porphyrin possessing four perfluorinated aromatic rings were conjugated with maltotriose (Mal3) via the nucleophilic aromatic substitution reaction and subsequent deprotection reaction of the oligosaccharide moieties. The resulting oligosaccharide-conjugated molecules are ultimately improved as compared to the previously reported monosaccharide-counterparts in terms of water-solubility. In particular, a water-soluble chlorin derivative surrounded by four Mal3 molecules showed an excellent biocompatibility, strong photoabsorption in the longer wavelength regions, and a very high photocytotoxicity. Thus, the present synthetic route combined with the use of an oligosaccharide was shown to be a straightforward strategy to develop a third generation photosensitizer for photodynamic therapy (PDT). PMID:26978428

  19. SOA Precursors: A Comparison of Semi-Volatile and Water Soluble Organic Gases During SOAS

    NASA Astrophysics Data System (ADS)

    Carlton, A. M. G.; Sareen, N.; Turpin, B. J.

    2014-12-01

    It is well-established that a major pathway for secondary organic aerosol (SOA) formation is via the partitioning of semi-volatile products of gas-phase photochemical reactions into preexisting organic particulate matter. Semi-volatile partitioning theory is widely used while modeling SOA. Despite its significance, parameterizations based solely on this formation pathway are unable to reproduce trends in SOA mass, particularly high atmospheric O/C ratios and enrichment of organic aerosol aloft. Recent studies have also highlighted the importance of formation of SOA through reactions of water-soluble organic gases (WSOG) in atmospheric waters (clouds, fogs, and wet aerosols). In order to understand the relative magnitude of potential precursors to SOA via both formation pathways, we modeled semi-volatile and WSOG concentrations during the Secondary Organic and Aerosol Study (SOAS) conducted in Brent, Alabama during June-July 2013. CMAQ 5.0.1 is used to predict mixing ratios of semi-volatile gases and WSOG over the continental US for a 10 day time period during SOAS. Our modeling results indicate that WSOG concentrations are an order of magnitude greater, on average, than the sum of semi-volatile gases. Interestingly, concentrations of semi-volatile gases increase aloft, unlike concentrations of WSOG. These results suggest that the potential for SOA formation from WSOG was high, and provide support for efforts to accurately model that multiphase chemistry in order to develop more effective air quality management strategies.

  20. Water-Soluble Luminescent Hybrid Composites Consisting of Oligosilsesquioxanes and Lanthanide Complexes and their Sensing Ability for Cu(2.).

    PubMed

    Xu, Qianqian; Li, Zhiqiang; Li, Huanrong

    2016-02-01

    Water-soluble hybrid composites with great potential for selective and sensitive sensing and that are obtained through simple, rapid, and environmentally friendly methods are highly desirable and remain a challenging task. Herein, we present luminescent hybrid composites that were realized by linking Na3 [Ln(dpa)3 ] (dpa=2,6-pyridinedicarboxylic acid) to octa-amino functionalized polyhedral oligomeric silsesquioxane (POSS-NH2 ) through hydrogen-bonding interactions between the oxygen atoms of the carboxylate groups of dpa and the hydrogen-bond-donor amino groups. The resulting hybrid composites Ln(dpa)3 @POSS-NH2 are highly soluble in aqueous solutions and the quantum yield of Eu(dpa)3 @POSS-NH2 is as high as 56.5 % or 46.3 % in the solid state and in aqueous solution, respectively, as determined by using the integrating sphere method. The novel water-soluble luminescent hybrid composites exhibit high thermal and photostability, and the emitted colors of the resulting hybrid composite can be finely tuned by changing the Eu(3+) /Tb(3+) ratio. Interestingly, Eu(dpa)3 @POSS-NH2 hybrid composites exhibited an effective switch-off fluorescence response to Cu(2+) over other common metal ions in aqueous media. PMID:26808058

  1. Antimicrobial Effect of Water-Soluble Muscadine Seed Extracts on Escherichia coli O157:H7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-soluble extracts were prepared from purple (cultivar Ison) and bronze (cultivar Carlos) muscadine seeds with or without heating. The Ison extracts had strong antimicrobial activity against a cocktail of three strains of Escherichia coli O157:H7. This extract had higher acidity (pH 3.39 to 3.43...

  2. 43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594.5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  3. 43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594.5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  4. 43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594.5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  5. 43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594.5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000)...

  6. Inactivation of Enterobacter sakazakii by Water-soluble Muscadine Seed Extracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hot and cold water-soluble muscadine (Vitis rotundifolia) seed extracts and their polar and polyphenol fractions from two Muscadine cultivars (‘Ison’, purple and ‘Carlos’, bronze) were investigated for their inhibition of Enterobacter sakazakii. The heat treatment on each seed extract not only incre...

  7. Profiling and relationship of water-soluble sugar and protein compositions in soybean seeds.

    PubMed

    Yu, Xiaomin; Yuan, Fengjie; Fu, Xujun; Zhu, Danhua

    2016-04-01

    Sugar and protein are important quality traits in soybean seeds for making soy-based food products. However, the investigations on both compositions and their relationship have rarely been reported. In this study, a total of 35 soybean germplasms collected from Zhejiang province of China, were evaluated for both water-soluble sugar and protein. The total water-soluble sugar (TWSS) content of the germplasms studied ranged from 84.70 to 140.91 mg/g and the water-soluble protein (WSP) content varied from 26.5% to 36.0%. The WSP content showed positive correlations with the TWSS and sucrose contents but negative correlations with the fructose and glucose contents. The clustering showed the 35 germplasms could be divided into four groups with specific contents of sugar and protein. The combination of water-soluble sugar and protein profiles provides useful information for future breeding and genetic research. This investigation will facilitate future work for seed quality improvement. PMID:26593554

  8. Polyoxometalate-directed assembly of water-soluble AgCl nanocubes.

    PubMed

    Neyman, Alevtina; Wang, Yifeng; Sharet, Shelly; Varsano, Neta; Botar, Bogdan; Kögerler, Paul; Meshi, Louisa; Weinstock, Ira A

    2012-02-21

    "Out-of-pocket" association of Ag(+) to the tetradentate defect site of mono-vacant Keggin and Wells-Dawson polyoxometalate (POM) cluster-anions is used to direct the formation of water-soluble AgCl nanocubes. PMID:22252035

  9. SURFACE PROPERTIES OF WATER SOLUBLE STARCH, STARCH ACETATES AND STARCH ACETATES/ALKENYLSUCCINATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface and interfacial tensions with hexadecane were measured for starch and water soluble starch ester solutions in order to determine their potential as stabilizers or emulsifiers. The surface tension for an acid hydrolysed starch (maltodextrin) initially declined with concentration and then rea...

  10. Simultaneous Determination of Water Soluble Vitamins in Dietary Supplements and Fortified Foods by LC-MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent work in our laboratory has focused on development of LC methods with diode array and/or mass spectrometry (ms) detection for the simultaneous determination in supplement tablets and fortified foods of several water-soluble vitamins (WSV) including: thiamin, niacin, pyridoxine, pantothenic ac...

  11. Role of protein solubility in water-holding capacity of broiler breast meat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role muscle protein denaturation plays in determining water-holding capacity (WHC) in broiler breast meat is not well understood. Alterations in muscle protein solubility due to postmortem pH and temperature decline can be used as indicators of protein denaturation. In order to determine the i...

  12. A water-soluble gadolinium metallofullerenol: facile preparation, magnetic properties and magnetic resonance imaging application.

    PubMed

    Li, Jie; Wang, Taishan; Feng, Yongqiang; Zhang, Ying; Zhen, Mingming; Shu, Chunying; Jiang, Li; Wang, Yuqing; Wang, Chunru

    2016-06-01

    A new water-soluble gadolinium metallofullerenol was prepared through a solid-liquid reaction. It was characterized to have an enhanced effective magnetic moment, and improved T1-weighted relaxivity and magnetic resonance imaging performance in the liver. This material prepared by a facile method has wide application as a contrast agent and biological medicine. PMID:27064096

  13. 40 CFR 799.6786 - TSCA water solubility: Generator column method.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false TSCA water solubility: Generator...: Generator column method. (a) Scope—(1) Applicability. This section is intended to meet the testing... the saturated solutions produced by the generator column. After extraction onto a...

  14. 40 CFR 799.6786 - TSCA water solubility: Generator column method.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false TSCA water solubility: Generator...: Generator column method. (a) Scope—(1) Applicability. This section is intended to meet the testing... the saturated solutions produced by the generator column. After extraction onto a...

  15. 40 CFR 799.6786 - TSCA water solubility: Generator column method.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false TSCA water solubility: Generator...: Generator column method. (a) Scope—(1) Applicability. This section is intended to meet the testing... the saturated solutions produced by the generator column. After extraction onto a...

  16. FATE OF WATER SOLUBLE AZO DYES IN THE ACTIVATED SLUDGE PROCESS

    EPA Science Inventory

    The objective of this study was to determine the partitioning of water soluble azo dyes in the activated sludge process (ASP). Azo dyes are of concern because some of the dyes, dye precursors , and/or their degradation products such as aromatic amines (which are also dye precurso...

  17. Solubility products and thermodynamic functions for the lanthanon fluoride-water systems

    SciTech Connect

    Menon, M.P.

    1988-12-01

    The specific objectives of this research were: (1) to measure the solubilities, solubility products and thermodynamic functions for the dissolution of the fluorides of six lanthanons (lanthanum, praseodymium, neodymium, samarium, gadolinium and lutetium) using radiometric, conductometric and potentiometric techniques; (2) to measure the stability constants of the fluoride complexes of each of the above lanthanide ions using a simplified potentiometric technique; and (3) to establish the general trend in the solubilities and thermodynamic functions for the lanthanon fluoride-water systems. Experimental results indicate that the solubilities and pk/sub sp/ values of lanthanon trifluorides do not follow a pattern of gradual increase or decrease with the atomic number of lanthanons. The solubilities of all lanthanon trifluorides in buffered solutions of constant ionic strength (0.5 M) show a minimum at a pH between 3 and 4. Standard enthalpy and free energy changes for the dissolution of the fluorides in water are both positive, while the entropy changes, except for YbF/sub 3/, are negative. Although the stability constant for the monofluoride complexes can be measured with great precision those for difluoride complexes have considerable error in measurement. The report includes six tables and five graphics containing experimental results and trends. (CAF)

  18. Size-dependent molecule-like to plasmonic transition in water-soluble glutathione stabilized gold nanomolecules

    NASA Astrophysics Data System (ADS)

    Kothalawala, Nuwan; Lee West, James, IV; Dass, Amala

    2013-12-01

    A size-dependent transition from molecule-like to plasmonic behaviour is demonstrated in the case of water soluble Au:SG nanomolecules. This was achieved using PAGE separation of smaller and larger nanomolecules, resulting in an unprecedented 26 bands, in a wide-range from 10's to 1000's of Au-atoms. PAGE separation of larger plasmonic nanomolecules is demonstrated for the first time. High resolution ESI-MS, with isotopic resolution, of smaller nanoparticles is reported, including the first time report of Au43(SG)26. This report will aid in the fundamental understanding of size-dependent properties of nanomolecules. The synthetic procedure employs a green approach with non-toxic chemicals and processes. The water solubility, non-toxicity and biocompatibility will lead to applications in biomedicine.A size-dependent transition from molecule-like to plasmonic behaviour is demonstrated in the case of water soluble Au:SG nanomolecules. This was achieved using PAGE separation of smaller and larger nanomolecules, resulting in an unprecedented 26 bands, in a wide-range from 10's to 1000's of Au-atoms. PAGE separation of larger plasmonic nanomolecules is demonstrated for the first time. High resolution ESI-MS, with isotopic resolution, of smaller nanoparticles is reported, including the first time report of Au43(SG)26. This report will aid in the fundamental understanding of size-dependent properties of nanomolecules. The synthetic procedure employs a green approach with non-toxic chemicals and processes. The water solubility, non-toxicity and biocompatibility will lead to applications in biomedicine. Electronic supplementary information (ESI) available: Detailed synthetic conditions, expanded MS, and optical spectra. This material is available free of charge via the Internet at http://pubs.acs.org. See DOI: 10.1039/c3nr03657j

  19. Water-soluble naphthalene diimides as singlet oxygen sensitizers.

    PubMed

    Doria, Filippo; Manet, Ilse; Grande, Vincenzo; Monti, Sandra; Freccero, Mauro

    2013-08-16

    Bromo- and/or alkylamino-substituted and hydrosoluble naphthalene diimides (NDIs) were synthesized to study their multimodal photophysical and photochemical properties. Bromine-containing NDIs (i.e., 11) behaved as both singlet oxygen ((1)O2) photosensitizers and fluorescent molecules upon irradiation at 532 nm. Among the NDIs not containing Br, only 12 exhibited photophysical properties similar to those of Br-NDIs, by irradiation above 610 nm, suggesting that for these NDIs both singlet and triplet excited-state properties are strongly affected by length, structure of the solubilizing moieties, and pH of the solution. Laser flash photolysis confirmed that the NDI lowest triplet excited state was efficiently populated, upon excitation at both 355 and 532 nm, and that free amine moieties quenched both the singlet and triplet excited states by intramolecular electron transfer, with generation of detectable radical anions. Time-resolved experiments, monitoring the 1270 nm (1)O2 phosphorescence decay generated upon laser irradiation at 532 nm, allowed a ranking of the NDIs as sensitizers, based on their (1)O2 quantum yields (ΦΔ). The tetrafunctionalized 12, exhibiting a long-lived triplet state (τ ~ 32 μs) and the most promising absorptivity for photodynamic therapy application, was tested as efficient photosensitizers in the photo-oxidations of 1,5-dihydroxynaphthalene and 9,10-anthracenedipropionic acid in acetonitrile and water. PMID:23869544

  20. Consequences of chirality on the dynamics of a water-soluble supramolecular polymer.

    PubMed

    Baker, Matthew B; Albertazzi, Lorenzo; Voets, Ilja K; Leenders, Christianus M A; Palmans, Anja R A; Pavan, Giovanni M; Meijer, E W

    2015-01-01

    The rational design of supramolecular polymers in water is imperative for their widespread use, but the design principles for these systems are not well understood. Herein, we employ a multi-scale (spatial and temporal) approach to differentiate two analogous water-soluble supramolecular polymers: one with and one without a stereogenic methyl. Initially aiming simply to understand the molecular behaviour of these systems in water, we find that while the fibres may look identical, the introduction of homochirality imparts a higher level of internal order to the supramolecular polymer. Although this increased order does not seem to affect the basic dimensions of the supramolecular fibres, the equilibrium dynamics of the polymers differ by almost an order of magnitude. This report represents the first observation of a structure/property relationship with regard to equilibrium dynamics in water-soluble supramolecular polymers. PMID:25698667

  1. Consequences of chirality on the dynamics of a water-soluble supramolecular polymer

    PubMed Central

    Baker, Matthew B.; Albertazzi, Lorenzo; Voets, Ilja K.; Leenders, Christianus M.A.; Palmans, Anja R.A.; Pavan, Giovanni M.; Meijer, E.W.

    2015-01-01

    The rational design of supramolecular polymers in water is imperative for their widespread use, but the design principles for these systems are not well understood. Herein, we employ a multi-scale (spatial and temporal) approach to differentiate two analogous water-soluble supramolecular polymers: one with and one without a stereogenic methyl. Initially aiming simply to understand the molecular behaviour of these systems in water, we find that while the fibres may look identical, the introduction of homochirality imparts a higher level of internal order to the supramolecular polymer. Although this increased order does not seem to affect the basic dimensions of the supramolecular fibres, the equilibrium dynamics of the polymers differ by almost an order of magnitude. This report represents the first observation of a structure/property relationship with regard to equilibrium dynamics in water-soluble supramolecular polymers. PMID:25698667

  2. Consequences of chirality on the dynamics of a water-soluble supramolecular polymer

    NASA Astrophysics Data System (ADS)

    Baker, Matthew B.; Albertazzi, Lorenzo; Voets, Ilja K.; Leenders, Christianus M. A.; Palmans, Anja R. A.; Pavan, Giovanni M.; Meijer, E. W.

    2015-02-01

    The rational design of supramolecular polymers in water is imperative for their widespread use, but the design principles for these systems are not well understood. Herein, we employ a multi-scale (spatial and temporal) approach to differentiate two analogous water-soluble supramolecular polymers: one with and one without a stereogenic methyl. Initially aiming simply to understand the molecular behaviour of these systems in water, we find that while the fibres may look identical, the introduction of homochirality imparts a higher level of internal order to the supramolecular polymer. Although this increased order does not seem to affect the basic dimensions of the supramolecular fibres, the equilibrium dynamics of the polymers differ by almost an order of magnitude. This report represents the first observation of a structure/property relationship with regard to equilibrium dynamics in water-soluble supramolecular polymers.

  3. Superhydrophilic molecularly imprinted polymers based on a water-soluble functional monomer for the recognition of gastrodin in water media.

    PubMed

    Ji, Wenhua; Zhang, Mingming; Wang, Daijie; Wang, Xiao; Liu, Jianhua; Huang, Luqi

    2015-12-18

    In this study, the first successfully developed superhydrophilic molecularly imprinted polymers (MIPs) for gastrodin recognition have been described. MIPs were prepared via the bulk polymerization process in an aqueous solution using alkenyl glycosides glucose (AGG) as the water-soluble functional monomer. The non-imprinted polymers (NIPs) were also synthesized using the same method without the use of the template. The dynamic water contact angles and photographs of the dispersion properties confirmed that the molecularly imprinted polymers displayed excellent superhydrophilicity. The results demonstrated that the MIPs exhibited high selectivity and an excellent imprinting effect. A molecularly imprinted solid phase extraction (MISPE) method was established. Optimization of various parameters affecting MISPE was investigated. Under the optimized conditions, a wide linear range (0.001-100.0μgmL(-1)) and low limits of detection (LOD) and quantification (LOQ) (0.03 and 0.09ngmL(-1), respectively) were achieved. When compared with the NIPs, higher recoveries (90.5% to 97.6%) of gastrodin with lower relative standard deviations values (below 6.4%) using high performance liquid chromatography were obtained at three spiked levels in three blank samples. These results demonstrated one efficient, highly selective and environmentally-friendly MISPE technique with excellent reproducibility for the purification and pre-concentration of gastrodin from an aqueous extract of Gastrodia elata roots. PMID:26627582

  4. Dynamics of heat, water, and soluble gas exchange in the human airways: 1. A model study.

    PubMed

    Tsu, M E; Babb, A L; Ralph, D D; Hlastala, M P

    1988-01-01

    In order to provide a means for analysis of heat, water, and soluble gas exchange with the airways during tidal ventilation, a one dimensional theoretical model describing heat and water exchange in the respiratory airways has been extended to include soluble gas exchange with the airway mucosa and water exchange with the mucous layer lining the airways. Not only do heat, water, and gas exchange occur simultaneously, but they also interact. Heating and cooling of the airway surface and mucous lining affects both evaporative water and soluble gas exchange. Water evaporation provides a major source of heat exchange. The model-predicted mean airway temperature profiles agree well with literature data for both oral and nasal breathing validating that part of the model. With model parameters giving the best fit to experimental data, the model shows: (a) substantial heat recovery in the upper airways, (b) minimal respiratory heat and water loss, and (c) low average mucous temperatures and maximal increases in mucous thickness. For resting breathing of room air, heat and water conservation appear to be more important than conditioning efficiency. End-tidal expired partial pressures of very soluble gases eliminated by the lungs are predicted to be lower than the alveolar partial pressures due to the absorption of the expired gases by the airway mucosa. The model may be usable for design of experiments to examine mechanisms associated with the local hydration and dehydration dynamics of the mucosal surface, control of bronchial perfusion, triggering of asthma, mucociliary clearance and deposition of inhaled pollutant gases. PMID:3228218

  5. 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). PMID:15811411

  6. Occurrence of selected volatile organic compounds and soluble pesticides in Texas public water-supply source waters, 1999-2001

    USGS Publications Warehouse

    Mahler, Barbara June; Canova, Michael G.; Gary, Marcus O.

    2002-01-01

    During 1999?2001, the U.S. Geological Survey, in cooperation with the Texas Natural Resource Conservation Commission, collected samples of untreated water from 48 public water-supply reservoirs and 174 public water-supply wells. The samples were analyzed for volatile organic compounds (VOCs) and soluble pesticides; in addition, well samples were analyzed for nitrite plus nitrate and tritium. This fact sheet summarizes the findings of the source-water sampling and analyses. Both VOCs and pesticides were detected much more frequently in surface water than in ground water. The only constituent detected at concentrations exceeding the maximum contaminant level for drinking water was nitrate. These results will be used in the Texas Source-Water Assessment Program to evaluate the susceptibility of public water-supply source waters to contamination.

  7. Lysozyme Solubility and Conformation in Neat Ionic Liquids and Their Mixtures with Water.

    PubMed

    Strassburg, Stephen; Bermudez, Harry; Hoagland, David

    2016-06-13

    The room temperature solubility of a number of model proteins is assessed for a diverse set of neat ionic liquids (ILs). For two soluble protein-IL pairs, lysozyme in [C2MIM][EtSO4] (1-ethyl-3-methylimidazolium ethylsulfate) and in [C2,4,4,4P][Et2PO4] (tributyl(ethyl)phosphonium diethylphosphate), protein solubility and structure at various temperatures are probed by dynamic light scattering (assessing dissolved molecular size), turbidimetry (reflecting degree of solubility), and Fourier transform infrared spectroscopy (uncovering helical secondary structure). As compared to aqueous environments, [C2,4,4,4P][Et2PO4] thermally stabilizes protein size and secondary structure while [C2MIM][EtSO4] does the opposite. Lysozyme denatured in [C2MIM][EtSO4] does not aggregate, presumably due to an absence of hydrophobic interactions, and the denaturation appears thermally reversible. Both ILs at room temperature are miscible with water in all proportions, but to create the corresponding ternary mixtures with protein, the order of mixing is important. Mixed to avoid additions of water to IL-dissolved protein, stable solutions are obtained with [C2MIM][EtSO4] at all solvent compositions. When water is added to IL-rich solutions, liquid-liquid demixing is noted. PMID:27159556

  8. Synthesis of water soluble glycosides of pentacyclic dihydroxytriterpene carboxylic acids as inhibitors of α-glucosidase.

    PubMed

    Xu, Jiancong; Nie, Xuliang; Hong, Yanping; Jiang, Yan; Wu, Guoqiang; Yin, Xiaoli; Wang, Chunrong; Wang, Xiaoqiang

    2016-04-01

    A series of compounds were synthesized by glycosylation of maslinic acid (MA) and corosolic acid (CA) with monosaccharides and disaccharides, and the structures of the derivatives were elucidated by standard spectroscopic methods including (1)H NMR, (13)C NMR and HRMS. The α-glucosidase inhibitory activities of all the novel compounds were evaluated in vitro. The solubility and inhibitory activity of α-glucosidase assays showed that the bis-disaccharide glycosides of triterpene acids possessed higher water solubility and α-glucosidase inhibitory activities than the bis-monosaccharide glycosides. Among these compounds, maslinic acid bis-lactoside (8e, IC50 = 684 µM) and corosolic acid bis-lactoside (9e, IC50 = 428 µM) had the best water solubility, and 9e exhibited a better inhibitory activity than acarbose (IC50 = 478 µM). However, most of glycosylated derivatives possessed lower inhibitory activities than the parent compounds, although their water solubility was enhanced obviously. Moreover, the kinetic inhibition studies indicated that 9e was a non-competitive inhibitor, and structure-activity relationships of the derivatives are also discussed. PMID:26974355

  9. Biodesulfurization of water-soluble coal-derived material by Rhodococcus rhodochrous IGTS8

    SciTech Connect

    Kilbane, J.J. II; Jackowski, K.

    1991-01-01

    Rhodococcus rhodochrous IGTS8 was previously isolated because of its ability to use coal as its sole source of sulfur for growth. Subsequent growth studies have revealed that IGTS8 is capable of using a variety of organosulfur compounds as sources of sulfur but not carbon. In this paper, the ability of IGTS8 to selectively remove organic sulfur from water-soluble coal-derived material is investigated. The microbial removal of organic sulfur from coal requires microorganisms capable of cleaving carbonsulfur bonds and the accessibility of these bonds to microorganisms. The use of water-soluble coal-derived material effectively overcomes the problem of accessibility and allows the ability of microorganisms to cleave carbonsulfur bonds present in coal-derived material to be assessed directly. Three coals, two coal solubilization procedures, and two methods of biodesulfurization were examined. The results of these experiments reveal that the microbial removal of significant amounts of organic sulfur from watersoluble coal-derived material with treatment times as brief as 24 hours is possible. Moreover, the carbon content and calorific value of biotreated products are largely unaffected. Biotreatment does, however, result in increases in the hydrogen and nitrogen content and a decreased oxygen content of the coal-derived material. The aqueous supernatant obtained from biodesulfurization experiments does not contain sulfate, sulfite, or other forms of soluble sulfur at increased concentrations in comparison with control samples. Sulfur removed from water-soluble coal-derived material appears to be incorporated into biomass.

  10. Water solubility of selected C9-C18 alkanes using a slow-stir technique: Comparison to structure - property models.

    PubMed

    Letinski, Daniel J; Parkerton, Thomas F; Redman, Aaron D; Connelly, Martin J; Peterson, Brian

    2016-05-01

    Aqueous solubility is a fundamental physical-chemical substance property that strongly influences the distribution, fate and effects of chemicals upon release into the environment. Experimental water solubility was determined for 18 selected C9-C18 normal, branched and cyclic alkanes. A slow-stir technique was applied to obviate emulsion formation, which historically has resulted in significant overestimation of the aqueous solubility of such hydrophobic liquid compounds. Sensitive GC-MS based methods coupled with contemporary sample extraction techniques were employed to enable reproducible analysis of low parts-per billion aqueous concentrations. Water solubility measurements for most of the compounds investigated, are reported for the first time expanding available data for branched and cyclic alkanes. Measured water solubilities spanned four orders of magnitude ranging from 0.3 μg/L to 250 μg/L. Good agreement was observed for selected alkanes tested in this work and reported in earlier literature demonstrating the robustness of the slow-stir water solubility technique. Comparisons of measured alkane water solubilities were also made with those predicted by commonly used quantitative structure-property relationship models (e.g. SPARC, EPIWIN, ACD/Labs). Correlations are also presented between alkane measured water solubilities and molecular size parameters (e.g. molar volume, solvent accessible molar volume) affirming a mechanistic description of empirical aqueous solubility results and prediction previously reported for a more limited set of alkanes. PMID:26924078

  11. Irreversible Catalyst Activation Enables Hyperpolarization and Water Solubility for NMR Signal Amplification by Reversible Exchange

    PubMed Central

    2015-01-01

    Activation of a catalyst [IrCl(COD)(IMes)] (IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; COD = cyclooctadiene)] for signal amplification by reversible exchange (SABRE) was monitored by in situ hyperpolarized proton NMR at 9.4 T. During the catalyst-activation process, the COD moiety undergoes hydrogenation that leads to its complete removal from the Ir complex. A transient hydride intermediate of the catalyst is observed via its hyperpolarized signatures, which could not be detected using conventional nonhyperpolarized solution NMR. SABRE enhancement of the pyridine substrate can be fully rendered only after removal of the COD moiety; failure to properly activate the catalyst in the presence of sufficient substrate can lead to irreversible deactivation consistent with oligomerization of the catalyst molecules. Following catalyst activation, results from selective RF-saturation studies support the hypothesis that substrate polarization at high field arises from nuclear cross-relaxation with hyperpolarized 1H spins of the hydride/orthohydrogen spin bath. Importantly, the chemical changes that accompanied the catalyst’s full activation were also found to endow the catalyst with water solubility, here used to demonstrate SABRE hyperpolarization of nicotinamide in water without the need for any organic cosolvent—paving the way to various biomedical applications of SABRE hyperpolarization methods. PMID:25372972

  12. Electrospun water-soluble polymer nanofibers for the dehydration and storage of sensitive reagents

    NASA Astrophysics Data System (ADS)

    Dai, Minhui; Senecal, Andre; Nugen, Sam R.

    2014-06-01

    The ability to preserve and deliver reagents remains an obstacle for the successful deployment of self-contained diagnostic microdevices. In this study we investigated the ability of bacteriophage T7 to be encapsulated and preserved in water soluble nanofibers. The bacteriophage T7 was added to mixtures of polyvinylpyrrolidone and water and electrospun onto a grounded plate. Trehalose and magnesium salts were added to the mixtures to determine their effect on the infectivity of the bacteriophage following electrospinning and during storage. The loss of T7 infectivity was determined immediately following electrospinning and during storage using agar overlay plating and plaque counting. The results indicate that the addition of magnesium salts protects the bacteriophage during the relatively violent and high voltage electrospinning process, but is not as effective as a protectant during storage of the dried T7. Conversely, the addition of trehalose into the electrospinning mix has little effect on the electrospinning, but a more significant role as a protectant during storage.

  13. Formulation and particle size reduction improve bioavailability of poorly water-soluble compounds with antimalarial activity.

    PubMed

    Wang, Hongxing; Li, Qigui; Reyes, Sean; Zhang, Jing; Xie, Lisa; Melendez, Victor; Hickman, Mark; Kozar, Michael P

    2013-01-01

    Decoquinate (DQ) is highly effective at killing malaria parasites in vitro; however, it is extremely insoluble in water. In this study, solid dispersion method was used for DQ formulation which created a suitable physical form of DQ in aqueous phase for particle manipulation. Among many polymers and surfactants tested, polyvinylpyrrolidone 10, a polymer, and L- α -phosphatidylcholine or polysorbate, two surfactants, were chosen as DQ formulation components. The formulation particles were reduced to a mean size between 200 to 400 nm, which was stable in aqueous medium for at least three weeks. Pharmacokinetic (PK) studies showed that compared to DQ microparticle suspension, a nanoparticle formulation orally dosed to mice showed a 14.47-fold increase in area under the curve (AUC) of DQ plasma concentration and a 4.53-fold increase in AUC of DQ liver distribution. WR 299666, a poorly water-soluble compound with antimalarial activity, was also tested and successfully made into nanoparticle formulation without undergoing solid dispersion procedure. We concluded that nanoparticles generated by using appropriate formulation components and sufficient particle size reduction significantly increased the bioavailability of DQ and could potentially turn this antimalarial agent to a therapeutic drug. PMID:23766925

  14. Structural investigation of water-soluble polysaccharides extracted from the fruit bodies of Coprinus comatus.

    PubMed

    Li, Bo; Dobruchowska, Justyna M; Gerwig, Gerrit J; Dijkhuizen, Lubbert; Kamerling, Johannis P

    2013-01-01

    Water-soluble polysaccharide material, extracted from the stipes of the fruit bodies of Coprinus comatus by hot water, was fractionated by sequential weak anion-exchange and size-exclusion chromatography. The relevant fractions were subjected to structural analysis, including (d/l) monosaccharide/methylation analysis and 1D/2D NMR spectroscopy. Besides the disaccharide α,α-trehalose [α-D-Glcp-(1↔1)-α-D-Glcp], high-molecular-mass α-D-glucans (the most abundant component) consisting of [→4)-α-D-Glcp-(1→](n) backbones with ~10% branching at C-6 by terminal α-D-Glcp-(1→6)- or α-D-Glcp-(1→6)-α-D-Glcp-(1→6)- units, lower-molecular-mass linear β-D-glucans consisting of [→6)-β-D-Glcp-(1→](m) sequences, and a lower-molecular-mass pentasaccharide-repeating α-L-fuco-α-D-galactan, {→6)-α-D-Galp-(1→6)-[α-L-Fucp-(1→2)-]α-D-Galp-(1→6)-α-D-Galp-(1→6)-α-D-Galp-(1→}(p), were found to be present. PMID:23044138

  15. Chemical properties and antioxidant activity of a water-soluble polysaccharide from Dendrobium officinale.

    PubMed

    Luo, Qiu-Lian; Tang, Zhuan-Hui; Zhang, Xue-Feng; Zhong, Yong-Hong; Yao, Su-Zhi; Wang, Li-Sheng; Lin, Cui-Wu; Luo, Xuan

    2016-08-01

    In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-β-d-mannopyranosyl and (1→4)-linked-β-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities. PMID:27131730

  16. Electrospun water-soluble polymer nanofibers for the dehydration and storage of sensitive reagents.

    PubMed

    Dai, Minhui; Senecal, Andre; Nugen, Sam R

    2014-06-01

    The ability to preserve and deliver reagents remains an obstacle for the successful deployment of self-contained diagnostic microdevices. In this study we investigated the ability of bacteriophage T7 to be encapsulated and preserved in water soluble nanofibers. The bacteriophage T7 was added to mixtures of polyvinylpyrrolidone and water and electrospun onto a grounded plate. Trehalose and magnesium salts were added to the mixtures to determine their effect on the infectivity of the bacteriophage following electrospinning and during storage. The loss of T7 infectivity was determined immediately following electrospinning and during storage using agar overlay plating and plaque counting. The results indicate that the addition of magnesium salts protects the bacteriophage during the relatively violent and high voltage electrospinning process, but is not as effective as a protectant during storage of the dried T7. Conversely, the addition of trehalose into the electrospinning mix has little effect on the electrospinning, but a more significant role as a protectant during storage. PMID:24815520

  17. Characterization and biodegradation of water-soluble biomarkers and organic carbon extracted from low temperature chars

    SciTech Connect

    Norwood, Matt J.; Louchouarn, Patrick; Kuo, Li-Jung; Harvey, Omar

    2013-03-16

    This study demonstrates that wildfires/biomass combustion may be an important source of labile pyrogenic water-soluble organic matter (Py-WSOM) to aquatic systems. Spectroscopic analysis (of the solid char and Py-WSOM) with Fourier transform infrared spectroscopy (FTIR) indicated that the Py-WSOM extracted from two low temperature chars (one wood, one grass) was dominated by polar moieties (-OH and C-O) derived from depolymerization and fragmentation of lignocellulose. Incubation experiments under aerobic conditions with unsterilized river water suggested that Py-WSOM and associated biomarkers may have turnover rates on the order of weeks to months, consistent with mixing and transport conditions of riverine systems. For example, pyrogenic dissolved organic carbon (Py-DOC) had a half-life of 30-40 days. Turnover rate for the combustion biomarkers was shorter, with levoglucosan and free lignin phenols having a half-life around 3-4 days and polymeric lignin components 13-14 days. The latter observations contradict earlier studies on the biodegradation of dissolved lignin and point to the need for re-assessment of lignin degradation kinetics in well-mixed riverine systems, particularly when such lignin components are derived from thermally altered plant material that may exist in a form more labile than that in highly processed riverine DOM.

  18. Extraction, characterization and antioxidant activity of water-soluble polysaccharides from Tuber huidongense.

    PubMed

    Chen, Guangjing; Zhang, Shiqi; Ran, Chunxia; Wang, Lisha; Kan, Jianquan

    2016-10-01

    Single-factor experiment and Box-Behnken design were employed to optimize the ultrasonic-assisted extraction (UAE) of water-soluble polysaccharides from Chinese truffle Tuber huidongense (THWP). The optimal extraction conditions with an extraction yield of 7.17±0.22% crude THWP were determined as follows: ultrasonic power 99.65W, extraction time 40.39min, ratio of water to raw material 24.65mL/g, and extraction temperature 70.1°C. Two purified fractions, THWP-1 and THWP-2 with molecular weights of 128kDa and 729kDa, respectively, were obtained from crude THWP by Cellulose DEAE-52 and Sephadex G-100 chromatography. Monosaccharide component analysis by high performance liquid chromatography (HPLC) indicated that THWP-1 was composed of Glc, Man, and Gal with their corresponding mole percentages of 60.56%, 20.12% and 19.32%, respectively and that THWP-2 contained only Glc. Evaluation of the antioxidant activity in vitro suggested that THWP-1 and THWP-2 had effective scavenging activity of 2,2'-azinobis-(3-ethylbenzothiazolin-6-sulfonicacid) (ABST), hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Accordingly, the polysaccharides from Chinese truffle might serve as a natural antioxidant in functional foods. PMID:27259646

  19. Water-soluble platinum phthalocyanines as potential antitumor agents.

    PubMed

    Bologna, Giuseppina; Lanuti, Paola; D'Ambrosio, Primiano; Tonucci, Lucia; Pierdomenico, Laura; D'Emilio, Carlo; Celli, Nicola; Marchisio, Marco; d'Alessandro, Nicola; Santavenere, Eugenio; Bressan, Mario; Miscia, Sebastiano

    2014-06-01

    Breast cancer represents the second cause of death in the European female population. The lack of specific therapies together with its high invasive potential are the major problems associated to such a tumor. In the last three decades platinum-based drugs have been considered essential constituents of many therapeutic strategies, even though with side effects and frequent generation of drug resistance. These drugs have been the guide for the research, in last years, of novel platinum and ruthenium based compounds, able to overcome these limitations. In this work, ruthenium and platinum based phthalocyanines were synthesized through conventional techniques and their antiproliferative and/or cytotoxic actions were tested. Normal mammary gland (MCF10A) and several models of mammarian carcinoma at different degrees of invasiveness (BT474, MCF-7 and MDA-MB-231) were used. Cells were treated with different concentrations (5-100 μM) of the above reported compounds, to evaluate toxic concentration and to underline possible dose-response effects. The study included growth curves made by trypan blue exclusion test and scratch assay to study cellular motility and its possible negative modulation by phthalocyanine. Moreover, we investigated cell cycle and apoptosis through flow cytometry and AMNIS Image Stream cytometer. Among all the tested drugs, tetrasulfonated phthalocyanine of platinum resulted to be the molecule with the best cytostatic action on neoplastic cell lines at the concentration of 30 μM. Interestingly, platinum tetrasulfophtalocyanine, at low doses, had no antiproliferative effects on normal cells. Therefore, such platinum complex, appears to be a promising drug for mammarian carcinoma treatment. PMID:24699848

  20. Dry heat or gaseous chemical resistance of Bacillus subtilis var. niger spores included within water-soluble crystals.

    PubMed

    Mullican, C L; Hoffman, R K

    1968-08-01

    Inclusion of spores of Bacillus subtilis var. niger in water-soluble crystals increased the resistance of the spores to dry heat and to a gaseous mixture of methyl bromide and ethylene oxide. Resistance of spores in glycine crystals to dry heat at 125 C was increased 5 to 24 times compared to unprotected spores. There appeared to be a positive correlation between the size of the crystal and the degree of resistance. The resistance to dry heat of spores included in sodium chloride crystals was about six times greater than unprotected spores. A gaseous mixture of methyl bromide (964 mg/liter) and ethylene oxide (642 mg/liter) at 37% relative humidity was ineffective in sterilizing spores enclosed within these water-soluble crystals, as was ethylene oxide alone. However, if the relative humidity was sufficiently high to dissolve the crystals during exposure to the vapor, viable-spore counts were drastically reduced or were negative. The surfaces of crystals grossly contaminated with dry spores were sterilized by exposure to gaseous ethylene oxide. Sterilization of heat-labile or moisture-labile materials with a critical requirement for sterility, as in planetary probes or drugs, may be complicated by the presence of spores in naturally occurring water-soluble crystals. This phenomenon is similar to the protection afforded spores entrapped in solid plastics. PMID:4970891

  1. Dry Heat or Gaseous Chemical Resistance of Bacillus subtilis var. niger Spores Included Within Water-soluble Crystals

    PubMed Central

    Mullican, Charles L.; Hoffman, Robert K.

    1968-01-01

    Inclusion of spores of Bacillus subtilis var. niger in water-soluble crystals increased the resistance of the spores to dry heat and to a gaseous mixture of methyl bromide and ethylene oxide. Resistance of spores in glycine crystals to dry heat at 125 C was increased 5 to 24 times compared to unprotected spores. There appeared to be a positive correlation between the size of the crystal and the degree of resistance. The resistance to dry heat of spores included in sodium chloride crystals was about six times greater than unprotected spores. A gaseous mixture of methyl bromide (964 mg/liter) and ethylene oxide (642 mg/liter) at 37% relative humidity was ineffective in sterilizing spores enclosed within these water-soluble crystals, as was ethylene oxide alone. However, if the relative humidity was sufficiently high to dissolve the crystals during exposure to the vapor, viable-spore counts were drastically reduced or were negative. The surfaces of crystals grossly contaminated with dry spores were sterilized by exposure to gaseous ethylene oxide. Sterilization of heat-labile or moisture-labile materials with a critical requirement for sterility, as in planetary probes or drugs, may be complicated by the presence of spores in naturally occurring water-soluble crystals. This phenomenon is similar to the protection afforded spores entrapped in solid plastics. PMID:4970891

  2. Simultaneous determination of water-soluble vitamins in beverages and dietary supplements by LC-MS/MS.

    PubMed

    Kakitani, Ayano; Inoue, Tomonori; Matsumoto, Keiko; Watanabe, Jun; Nagatomi, Yasushi; Mochizuki, Naoki

    2014-01-01

    An LC-MS/MS method was developed for the simultaneous determination of 15 water-soluble vitamins that are widely used as additives in beverages and dietary supplements. This combined method involves the following simple pre-treatment procedures: dietary supplement samples were prepared by centrifugation and filtration after an extraction step, whereas beverage samples were diluted prior to injection. Chromatographic analysis in this method utilised a multi-mode ODS column, which provided reverse-phase, anion- and cation-exchange capacities, and therefore improved the retention of highly polar analytes such as water-soluble vitamins. Additionally, the multi-mode ODS column did not require adding ion pair reagents to the mobile phase. We optimised the chromatographic separation of 15 water-soluble vitamins by adjusting the mobile phase pH and the organic solvent. We also conducted an analysis of a NIST Standard Reference Material (SRM 3280 Multi-vitamin/Multi-element tablets) using this method to verify its accuracy. In addition, the method was applied to identify the vitamins in commercial beverages and dietary supplements. By comparing results with the label values and results obtained by official methods, it was concluded that the method could be used for quality control and to compose nutrition labels for vitamin-enriched products. PMID:25325190

  3. The water-soluble fraction of carbon, sulfur, and crustal elements in Asian aerosols and Asian soils

    NASA Astrophysics Data System (ADS)

    Duvall, R. M.; Majestic, B. J.; Shafer, M. M.; Chuang, P. Y.; Simoneit, B. R. T.; Schauer, J. J.

    We quantified the water-soluble species in 24 h average TSP (Dunhuang and Gosan) and PM1.0 (Gosan only) samples associated with the Spring 2001 Asian Dust season. Samples were analyzed for water-soluble organic carbon, water-soluble sulfur, and water-soluble crustal elements, as well as their bulk chemical composition. Water-soluble organic carbon in Gosan accounted for 28-83% (average=63%) of the particle-phase TSP total organic carbon, and 1-69% (average=23%) of the particle-phase PM1.0 organic carbon. Water-soluble sulfur, primarily in the form of sulfate, accounted for 2-22% of the TSP mass in Gosan, and 0.9-11% of the TSP mass in Dunhuang. The absolute concentrations and the soluble fraction of crustal elements in TSP samples collected at Gosan were found to correlate with the air mass source region as determined by back-trajectory analysis. For example, elevated levels of water-soluble sodium, potassium, and calcium were observed during dust events. These observations are likely the result of differences in anthropogenic sources, mineralogical composition of resuspended crustal materials, and atmospheric processing of the aerosols. Experiments were conducted using Asian soil samples to study the impact of acidification by nitric acid vapor on the solubility of crustal elements present in Asian desert and non-desert dusts. These experiments demonstrated that gaseous nitric acid attack leads to significant increases (>100% increase) in water-soluble calcium, magnesium, aluminum, manganese, and iron, while little or no increases in water-soluble sodium and potassium were observed in the soils.

  4. Spectrophotometric Determination of Poorly Water Soluble Drug Rosiglitazone Using Hydrotropic Solubilization technique

    PubMed Central

    Sherje, A. P.; Desai, K. J.

    2011-01-01

    In the present investigation, hydrotropic solution of urea was employed as a solubilizing agent for spectrophotometric determination of poorly water-soluble drug rosiglitazone maleate. In solubility determination study, it was found that there was more than 14-folds enhancement in solubility of rosiglitazone maleate in a 6M solution of urea. Rosiglitazone maleate obeys Beer's law in concentration range of 5-300 μg/ml. Linearity of rosiglitazone maleate was found in the range of 80-120% of the label claim. The proposed method has been applied successfully to the analysis of the cited drug in pharmaceutical formulations with good accuracy and precision. The method herein described is new, simple, eco-friendly, economic, and accurate and can be utilized in routine analysis of rosiglitazone maleate in bulk drug and tablet dosage form. PMID:22923874

  5. Spectrophotometric Determination of Poorly Water Soluble Drug Rosiglitazone Using Hydrotropic Solubilization technique.

    PubMed

    Sherje, A P; Desai, K J

    2011-09-01

    In the present investigation, hydrotropic solution of urea was employed as a solubilizing agent for spectrophotometric determination of poorly water-soluble drug rosiglitazone maleate. In solubility determination study, it was found that there was more than 14-folds enhancement in solubility of rosiglitazone maleate in a 6M solution of urea. Rosiglitazone maleate obeys Beer's law in concentration range of 5-300 μg/ml. Linearity of rosiglitazone maleate was found in the range of 80-120% of the label claim. The proposed method has been applied successfully to the analysis of the cited drug in pharmaceutical formulations with good accuracy and precision. The method herein described is new, simple, eco-friendly, economic, and accurate and can be utilized in routine analysis of rosiglitazone maleate in bulk drug and tablet dosage form. PMID:22923874

  6. Green synthesis of water soluble semiconductor nanocrystals and their applications

    NASA Astrophysics Data System (ADS)

    Wang, Ying

    well as high-throughput and simplicity of photolithography. Photoconductive LBL thin films are fabricated from Te nanowires. The thin film has distinctively metallic mirror-like appearance and displays strong photoconductance effect characteristic of narrow band-gap semiconductors. In-situ reduction of gold results in formation of Au nanoparticles adhering to Te nanowires, which leads to the disappearance of photoconductivity of the Te thin film. Those nanomaterials are considered for various applications, such as light emitting devices, data storage materials, biosensors, photodetectors.

  7. β-Cyclodextrin functionalized carbon quantum dots as sensors for determination of water-soluble C60 fullerenes in water.

    PubMed

    Cayuela, Angelina; Laura Soriano, M; Valcárcel, Miguel

    2016-04-25

    A selective photoluminescence method based on Carbon Quantum Dots (CQDs) functionalized with carboxymethyl-β-cyclodextrin for the direct determination of water-soluble C60 fullerene has been developed. CQDs were synthesized using a top-down methodology from multiwall carbon nanotubes (MWCNTs) and further functionalized with N-Boc-ethylenediamine to confer monoprotected amine groups onto their surface. Once amine-functionalized CQDs were obtained after deprotection, an amidation reaction with carboxymethyl-β-cyclodextrin cavitands was achieved and the obtained fluorescent β-cyclodextrin functionalized Carbon Quantum Dots (cd-CQDs) were investigated for the inclusion complexation of water-soluble C60. Quenching of their fluorescence was observed owing to the non-covalent self-assembly of cd-CQDs and C60, making possible the quantification of C60. A method to determine water-soluble C60 is then proposed with detection and quantification limits of 0.525 and 1.751 μg mL(-1), respectively. The method was validated by determining soluble C60 fullerene in spiked river water. One added value of the paper is the fact that it can be ascribed to the "Third Way in Analytical Nanoscience and Nanotechnology". PMID:26870854

  8. Direct atmospheric deposition of water-soluble nitrogen to the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Jordan, C. E.; Talbot, R. W.

    2000-12-01

    Measurements were made at New Castle, New Hampshire, on the shore of the Gulf of Maine from 1994 to 1997 to assess direct atmospheric deposition of water-soluble nitrogen to the surface waters of the gulf. Daily dry deposition was highly variable and ranged from ˜ 1 to 144 μmol N m-2 d-1 (median 16 μmol N m-2 d-1). Wet deposition dominated dry deposition, contributing 80-90% of the total flux annually. Wet deposition was also highly variable and ranged from 3 to 4264 μmol N m-2 d-1 (median 214 μmol N m-2 d-1). Fog water nitrogen deposition could contribute as much as large precipitation nitrogen deposition events, in excess of 500 μmol N m-2d-1. Dissolved organic nitrogen (DON) in precipitation constituted only a small fraction (3%) of the total precipitation nitrogen flux most of the year, except in spring where it comprised 14%, on average, of the total. The total atmospheric direct nitrogen (ADN) deposition numbers reported here do not include the contributions of fog and DON as they were not sampled regularly over the course of this study. The total ADN flux ranged from 1 to 4262 μmol N m-2 d-1 (median 23 μmol N m-2 d-1), depositing 52 mmol N m-2 yr-1 to the surface waters of the Gulf of Maine, 3% of the total N input to those waters annually. However, this deposition was highly episodic with events over 500 μmol N m-2 d-1 occurring in 8% of the days sampled but contributing 56% of the total measured flux and events in excess of 1000 μmol N m-2 d-1 occurring in 2% of the samples and contributing 22% of the total measured flux. It is these large events that may influence biological productivity of the Gulf of Maine. The annual wet deposition of inorganic N measured at New Castle exceeded that reported by two National Atmospheric Deposition Program (NADP) sites by 42% on average of that reported from Cape Cod, Massachusetts, and by 69% ofthat at Mt. Dessert Island, Maine. Estimates of the episodic atmospheric nitrogen flux to the surface waters of the

  9. Solubility and some crystallization properties of conglomerate forming chiral drug guaifenesin in water.

    PubMed

    Fayzullin, Robert R; Lorenz, Heike; Bredikhina, Zemfira A; Bredikhin, Alexander A; Seidel-Morgenstern, Andreas

    2014-10-01

    The solubility of 3-(2-methoxyphenoxy)-propane-1,2-diol, the well-known chiral drug guaifenesin 1, in water has been investigated by means of polythermal and isothermal approaches. It was found that the solubilities of racemic and enantiomeric diols rac- and (R)-1 depend strongly on temperature. The ternary phase diagram of the guaifenesin enantiomers in water in the temperature range between 10°C and 40°C was constructed. Clear evidence was obtained that rac-1 crystallizes as a stable conglomerate. The Meyerhoffer coefficient for the guaifenesin-water system is more than two and strongly depends on temperature. Neither crystalline hydrates nor polymorphs were detected within the range of conditions covered. Metastable zone width data with regard to primary nucleation were also collected for rac-1 and (R)-1. On the basis of the knowledge acquired, the resolution of racemic guaifenesin by preferential crystallization from solution could be realized successfully. PMID:25091705

  10. Photophysical Properties and Singlet Oxygen Generation Efficiencies of Water-Soluble Fullerene Nanoparticles

    PubMed Central

    Stasheuski, Alexander S; Galievsky, Victor A; Stupak, Alexander P; Dzhagarov, Boris M; Choi, Mi Jin; Chung, Bong Hyun; Jeong, Jin Young

    2014-01-01

    As various fullerene derivatives have been developed, it is necessary to explore their photophysical properties for potential use in photoelectronics and medicine. Here, we address the photophysical properties of newly synthesized water-soluble fullerene-based nanoparticles and polyhydroxylated fullerene as a representative water-soluble fullerene derivative. They show broad emission band arising from a wide-range of excitation energies. It is attributed to the optical transitions from disorder-induced states, which decay in the nanosecond time range. We determine the kinetic properties of the singlet oxygen (1O2) luminescence generated by the fullerene nanoparticles and polyhydroxylated fullerene to consider the potential as photodynamic agents. Triplet state decay of the nanoparticles was longer than 1O2 lifetime in water. Singlet oxygen quantum yield of a series of the fullerene nanoparticles is comparably higher ranging from 0.15 to 0.2 than that of polyhydroxylated fullerene, which is about 0.06. PMID:24893622

  11. Method of cross-linking polyvinyl alcohol and other water soluble resins

    NASA Technical Reports Server (NTRS)

    Phillipp, W. H.; May, C. E.; Hsu, L. C.; Sheibley, D. W. (Inventor)

    1980-01-01

    A self supporting sheet structure comprising a water soluble, noncrosslinked polymer such as polyvinyl alcohol which is capable of being crosslinked by reaction with hydrogen atom radicals and hydroxyl molecule radicals is contacted with an aqueous solution having a pH of less than 8 and containing a dissolved salt in an amount sufficient to prevent substantial dissolution of the noncrosslinked polymer in the aqueous solution. The aqueous solution is then irradiated with ionizing radiation to form hydrogen atom radicals and hydroxyl molecule radicals and the irradiation is continued for a time sufficient to effect crosslinking of the water soluble polymer to produce a water insoluble polymer sheet structure. The method has particular application in the production of battery separators and electrode envelopes for alkaline batteries.

  12. A recipe for designing water-soluble, beta-sheet-forming peptides.

    PubMed Central

    Mayo, K. H.; Ilyina, E.; Park, H.

    1996-01-01

    Based on observations of solubility and folding properties of peptide 33-mers derived from the beta-sheet domains of platelet factor-4 (PF4), interleukin-8 (IL-8), and growth related protein (Gro-alpha), as well as other beta-sheet-forming peptides, general guidelines have been developed to aid in the design of water soluble, self-association-induced beta-sheet-forming peptides. CD, 1H-NMR, and pulsed field gradient NMR self-diffusion measurements have been used to assess the degree of folding and state of aggregation. PF4 peptide forms native-like beta-sheet tetramers and is sparingly soluble above pH 6. IL-8 peptide is insoluble between pH 4.5 and pH 7.5, yet forms stable, native-like beta-sheet dimers at higher pH. Gro-alpha peptide is soluble at all pH values, yet displays no discernable beta-sheet structure even when diffusion data indicate dimer-tetramer aggregation. A recipe used in the de novo design of water-soluble beta-sheet-forming peptides calls for the peptide to contain 40-50% hydrophobic residues, usually aliphatic ones (I, L, V, A, M) (appropriately paired and mostly but not always alternating with polar residues in the sheet sequence), a positively charged (K, R) to negatively charged (E, D) residue ratio between 4/2 and 6/2, and a noncharged polar residue (N, Q, T, S) composition of about 20% or less. Results on four de novo designed, 33-residue peptides are presented supporting this approach. Under near physiologic conditions, all four peptides are soluble, form beta-sheet structures to varying degrees, and self-associate. One peptide folds as a stable, compact beta-sheet tetramer, whereas the others are transient beta-sheet-containing aggregates. PMID:8819163

  13. Dendrimer-curcumin conjugate: a water soluble and effective cytotoxic agent against breast cancer cell lines.

    PubMed

    Debnath, Shawon; Saloum, Darin; Dolai, Sukanta; Sun, Chong; Averick, Saadyah; Raja, Krishnaswami; Fata, Jimmie E

    2013-12-01

    Curcumin, which is derived from the plant Curcuma longa, has received considerable attention as a possible anti-cancer agent. In cell culture, curcumin is capable of inducing apoptosis in cancer cells at concentrations that do not affect normal cells. One draw-back holding curcumin back from being an effective anti-cancer agent in humans is that it is almost completely insoluble in water and therefore has poor absorption and subsequently poor bioavailability. Here we have generated a number of curcumin derivatives (tetrahydro-curcumin, curcumin mono-carboxylic acid, curcumin mono-galactose, curcumin mono-alkyne and dendrimer-curcumin conjugate) to test whether any of them display both cytotoxicity and water solubility. Of those tested only dendrimer-curcumin conjugate exhibited both water solubility and cytotoxicity against SKBr3 and BT549 breast cancer cells. When compared to curcumin dissolved in DMSO, dendrimer-curcumin conjugate dissolved in water was significantly more effective in inducing cytotoxicity, as measured by the MTT assay and effectively induced cellular apoptosis measured by caspase-3 activation. Since dendrimer-curcumin conjugate is water soluble and capable of inducing potent cytotoxic effects on breast cancer cell lines, it may prove to be an effective anti-cancer therapy to be used in humans. PMID:23387971

  14. Experimental Solubility Approach to Determine PDMS-Water Partition Constants and PDMS Activity Coefficients.

    PubMed

    Grant, Sharon; Schacht, Veronika J; Escher, Beate I; Hawker, Darryl W; Gaus, Caroline

    2016-03-15

    Freely dissolved aqueous concentration and chemical activity are important determinants of contaminant transport, fate, and toxic potential. Both parameters are commonly quantified using Solid Phase Micro-Extraction (SPME) based on a sorptive polymer such as polydimethylsiloxane (PDMS). This method requires the PDMS-water partition constants, KPDMSw, or activity coefficient to be known. For superhydrophobic contaminants (log KOW >6), application of existing methods to measure these parameters is challenging, and independent measures to validate KPDMSw values would be beneficial. We developed a simple, rapid method to directly measure PDMS solubilities of solid contaminants, SPDMS(S), which together with literature thermodynamic properties was then used to estimate KPDMSw and activity coefficients in PDMS. PDMS solubility for the test compounds (log KOW 7.2-8.3) ranged over 3 orders of magnitude (4.1-5700 μM), and was dependent on compound class. For polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs), solubility-derived KPDMSw increased linearly with hydrophobicity, consistent with trends previously reported for less chlorinated congeners. In contrast, subcooled liquid PDMS solubilities, SPDMS(L), were approximately constant within a compound class. SPDMS(S) and KPDMSw can therefore be predicted for a compound class with reasonable robustness based solely on the class-specific SPDMS(L) and a particular congener's entropy of fusion, melting point, and aqueous solubility. PMID:26881312

  15. Enhanced water-solubility, antibacterial activity and biocompatibility upon introducing sulfobetaine and quaternary ammonium to chitosan.

    PubMed

    Chen, Yuxiang; Li, Jianna; Li, Qingqing; Shen, Yuanyuan; Ge, Zaochuan; Zhang, Wenwen; Chen, Shiguo

    2016-06-01

    Chitosan (CS) has attracted much attention due to its good antibacterial activity and biocompatibility. However, CS is insoluble in neutral and alkaline aqueous solution, limiting its biomedical application to some extent. To circumvent this drawback, we have synthesized a novel N-quaternary ammonium-O-sulfobetaine-chitosan (Q3BCS) by introducing quaternary ammonium compound (QAC) and sulfobetaine, and its water-solubility, antibacterial activity and biocompatibility were evaluated compare to N-quaternary ammonium chitosan and native CS. The results showed that by introducing QAC, antibacterial activities and water-solubilities increase with degrees of substitution. The largest diameter zone of inhibition (DIZ) was improved from 0 (CS) to 15mm (N-Q3CS). And the water solution became completely transparent from pH 6.5 to pH 11; the maximal waters-solubility was improved from almost 0% (CS) to 113% at pH 7 (N-Q3CS). More importantly, by further introducing sulfobetaine, cell survival rate of Q3BCS increased from 30% (N-Q3CS) to 85% at 2000μg/ml, which is even greater than that of native CS. Furthermore, hemolysis of Q3BCS was dropped sharply from 4.07% (N-Q3CS) to 0.06%, while the water-solution and antibacterial activity were further improved significantly. This work proposes an efficient strategy to prepare CS derivatives with enhanced antibacterial activity, biocompatibility and water-solubility. Additionally, these properties can be finely tailored by changing the feed ratio of CS, glycidyl trimethylammonium chloride and NCO-sulfobetaine. PMID:27083366

  16. Silica gel as a particulate carrier of poorly water-soluble substances in aquatic toxicity testing.

    PubMed

    Breitholtz, Magnus; Ricklund, Niklas; Bengtsson, Bengt-Erik; Persson, N Johan

    2007-05-31

    Aquatic toxicity tests were originally developed for water-soluble substances. However, many substances are hydrophobic and thus poorly water-soluble, resulting in at least two major implications. Firstly, toxicity may not be reached within the range of water solubility of the tested compound(s), which may result in the formation of solids or droplets of the tested substance and consequently an uneven exposure. Secondly, because of multi-phase distribution of the tested substance it may be complicated to keep exposure concentrations constant. To overcome such problems, we have introduced silica gel as a particulate carrier in a toxicity test with the benthic copepod Nitocra spinipes. The main objective of the current study was to evaluate whether a controlled exposure could be achieved with the help of silica gel for testing single poorly water-soluble substances. A secondary objective was to evaluate whether an equilibrium mass balance model could predict internal concentrations that were consistent with the toxicity data and measured internal concentrations of two model hydrophobic substances, i.e., the polybrominated diphenyl ethers BDE-47 and BDE-99. Larval N. spinipes were exposed for 6 days to BDE-47 and BDE-99, respectively, in the silica gel test system and, for comparative reasons, in a similar and more traditional semi-static water test system. Via single initial amounts of the model substances administered on the silica gel, effects on both larval development and mortality resulted in higher and more concentration-related toxicity than in the water test system. We conclude that the silica gel test system enables a more controlled exposure of poorly water-soluble substances than the traditional water test system since the concentration-response relationship becomes distinct and there is no carrier solvent present during testing. Also, the single amount of added substance given in the silica gel test system limits the artefacts (e.g., increased chemical

  17. Conductive methyl blue-functionalized reduced graphene oxide with excellent stability and solubility in water

    SciTech Connect

    Cai, Xiang; Tan, Shaozao; Xie, Agui; Lin, Minsong; Liu, Yingliang; Zhang, Xiuju; Lin, Zhidan; Wu, Ting; Mai, Wenjie

    2011-12-15

    Graphical abstract: MB-rGO was synthesized by making use of {pi} stacking and water-solubility of MB to assist the hydrazine mediated reduction of graphene oxide (GO) in aqueous solution. The resulting MB-rGO shows excellent solubility and stability in aqueous solution, and the electrical conductivity of MB-rGO is almost two orders of magnitude larger than that of GO. Highlights: Black-Right-Pointing-Pointer Methyl blue (MB) stacks onto the plane of reduced graphene oxide (rGO) by strong {pi}-{pi} interactions. Black-Right-Pointing-Pointer Sulfo groups of MB prevent rGO from aggregating by electrostatic and steric repulsions. Black-Right-Pointing-Pointer MB-functionalized rGO (MB-rGO) shows excellent solubility and stability in aqueous solution. Black-Right-Pointing-Pointer Electrical conductivity of MB-rGO is almost two orders of magnitude larger than that of GO. -- Abstract: {pi} stacking and water-solubility of methyl blue (MB) are expected to facilitate the hydrazine mediated reduction of graphene oxide (GO) in aqueous environment. Our newly obtained MB-functionalized reduced graphene oxide (MB-rGO) exhibited excellent solubility and stability in water. The results showed that the MB molecules stacked non-covalently onto the basal plane of rGO while the sulfo groups of MB prevented the rGO from aggregation. In addition, the better electrical conductivity of MB-rGO than that of GO was analyzed. This novel conductive MB-rGO should have promising applications in diverse nanotechnological areas, such as electronic and optoelectronic devices, photovoltaics, sensors, and microfabrication.

  18. Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong

    NASA Astrophysics Data System (ADS)

    Ho, K. F.; Lee, S. C.; Cao, J. J.; Li, Y. S.; Chow, J. C.; Watson, J. G.; Fung, K.

    2006-10-01

    To determine the levels and variations of carbonaceous aerosol in Hong Kong, PM2.5 and PM10 samples were collected by high volume (Hi-vol) samplers at three monitoring stations (representing middle-scale roadside, urban-, and regional-scale environments) during winter (November 2000 to February 2001) and summer (June 2001 to August 2001) periods. The highest concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were found at the middle-scale roadside site with the lowest at the regional-scale site. The percentages of WSOC in total carbon at these sites were inversely correlated with their concentrations (i.e., the highest percentages of WSOC were observed at the regional-scale site). A high WSOC fraction may be associated with aged aerosol because of the secondary formation by photochemical oxidation of organic precursors of anthropogenic pollutants during transport. The annual average of isotope abundances (δ13C) of OC and EC were -26.9±0.5‰ and -25.6±0.1‰, respectively. There were no notable differences for seasonal distributions of carbon isotopic composition, consistent with motor vehicle emissions being the main source contributors of carbonaceous aerosol in Hong Kong. OC 13C abundances at the regional-scale site were higher than those at the middle-scale roadside and urban sites, consistent with secondary organic aerosols of biogenic origin.

  19. Variability of organic and elemental carbon, water soluble organic carbon, and isotopes in Hong Kong

    NASA Astrophysics Data System (ADS)

    Ho, K. F.; Lee, S. C.; Cao, J. J.; Li, Y. S.; Chow, J. C.; Watson, J. G.; Fung, K.

    2006-06-01

    To determine the levels and variations of carbonaceous aerosol in Hong Kong, PM2.5 and PM10 samples were collected by high volume (Hi-vol) samplers at three monitoring stations (representing middle-scale roadside, urban-, and regional-scale environments) during winter (November 2000 to February 2001) and summer (June 2001 to August 2001) periods. The highest concentrations of organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were found at the middle-scale roadside site with the lowest at the regional-scale site. The percentages of WSOC in total carbon at these sites were inversely correlated with their concentrations (i.e., the highest percentages of WSOC were observed at the regional-scale site). A high WSOC fraction may be associated with aged aerosol because of the secondary formation by photochemical oxidation of organic precursors of anthropogenic pollutants during transport. The annual average of isotope abundances (δ13C) of OC and EC were -26.9±0.5 and -25.6±0.1, respectively. There were no notable differences for seasonal distributions of carbon isotopic composition, consistent with motor vehicle emissions being the main source contributors of carbonaceous aerosol in Hong Kong. OC 13C abundances at the regional-scale site were higher than those at the middle-scale roadside and urban sites, consistent with secondary organic aerosols of biogenic origin.

  20. Fluorescent polystyrene photonic crystals self-assembled with water-soluble conjugated polyrotaxanes

    NASA Astrophysics Data System (ADS)

    Di Stasio, Francesco; Berti, Luca; McDonnell, Shane O.; Robbiano, Valentina; Anderson, Harry L.; Comoretto, Davide; Cacialli, Franco

    2013-10-01

    We demonstrate control of the photoluminescence spectra and decay rates of water-soluble green-emitting conjugated polyrotaxanes by incorporating them in polystyrene opals with a stop-band spectrally tuned on the rotaxane emission (405-650 nm). We observe a suppression of the luminescence within the photonic stop-band and a corresponding enhancement of the high-energy edge (405-447 nm). Time-resolved measurements reveal a wavelength-dependent modification of the emission lifetime, which is shortened at the high-energy edge (by ˜11%, in the range 405-447 nm), but elongated within the stop-band (by ˜13%, in the range 448-482 nm). We assign both effects to the modification of the density of photonic states induced by the photonic crystal band structure. We propose the growth of fluorescent composite photonic crystals from blends of "solvent-compatible" non-covalently bonded nanosphere-polymer systems as a general method for achieving a uniform distribution of polymeric dopants in three-dimensional self-assembling photonic structures.

  1. Diagnostic image quality of hysterosalpingography: ionic versus non ionic water soluble iodinated contrast media

    PubMed Central

    Mohd Nor, H; Jayapragasam, KJ; Abdullah, BJJ

    2009-01-01

    Objective To compare the diagnostic image quality between three different water soluble iodinated contrast media in hysterosalpingography (HSG). Material and method In a prospective randomised study of 204 patients, the diagnostic quality of images obtained after hysterosalpingography were evaluated using Iopramide (106 patients) and Ioxaglate (98 patients). 114 patients who had undergone HSG examination using Iodamide were analysed retrospectively. Image quality was assessed by three radiologists independently based on an objective set of criteria. The obtained results were statistically analysed using Kruskal-Wallis and Mann-Whitney U test. Results Visualisation of fimbrial rugae was significantly better with Iopramide and Ioxaglate than Iodamide. All contrast media provided acceptable diagnostic image quality with regard to uterine, fallopian tubes outline and peritoneal spill. Uterine opacification was noted to be too dense in all three contrast media and not optimal for the assessment of intrauterine pathology. Higher incidence of contrast intravasation was noted in the Iodamide group. Similarly, the numbers of patients diagnosed with bilateral blocked fallopian tubes were also higher in the Iodamide group. Conclusion HSG using low osmolar contrast media (Iopramide and Ioxaglate) demonstrated diagnostic image qualities similar to HSG using conventional high osmolar contrast media (Iodamide). However, all three contrast media were found to be too dense for the detection of intrauterine pathology. Better visualisation of the fimbrial outline using Ioxaglate and Iopramide were attributed to their low contrast viscosity. The increased incidence of contrast media intravasation and bilateral tubal blockage using Iodamide are probably related to the high viscosity. PMID:21611058

  2. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    SciTech Connect

    Smith, B.F.; Gibson, R.R.; Jarvinen, G.D.; Jones, M.M.; Lu, M.T.; Robison, T.W.; Schroeder, N.C.; Stalnaker, N.

    1997-12-31

    Routine counting methods and ICP-MS are unable to directly measure the new US Department of Energy (DOE) regulatory level for discharge waters containing alpha-emitting radionuclides of 30 pCi/L total alpha or the 0.05 pCi/L regulatory level for Pu or Am activity required for surface waters at the Rocky Flats site by the State of Colorado. This inability indicates the need to develop rapid, reliable, and robust analytical techniques for measuring actinide metal ions, particularly americium and plutonium. Selective separation or preconcentration techniques would aid in this effort. Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for {sup 241}Am(III) and {sup 238}Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4.

  3. Rapid isolation, reliable characterization, and water solubility improvement of polymethoxyflavones from cold-pressed mandarin essential oil.

    PubMed

    Russo, Marina; Rigano, Francesca; Arigò, Adriana; Sciarrone, Danilo; Calabrò, Maria Luisa; Farnetti, Sara; Dugo, Paola; Mondello, Luigi

    2016-06-01

    Polymethoxyflavones possess many biological properties, as lipid-lowering, hypoglycaemic, anti-inflammatory, antioxidant, and anticancer activities, therefore, they may be employed as nutraceuticals or therapeutic agents. The scarcity of pure polymethoxyflavones on the market as well as their low water solubility limited in vivo studies and the use of polymethoxyflavones as food or pharmaceutical supplements. Since mandarin peels are a rich source of polymethoxyflavones, tangeretin, nobiletin, sinensetin, tetra-O-methyl scutellarein, and heptamethoxyflavone were purified from a nonvolatile residue of a cold-pressed mandarin essential oil using a multidimensional preparative liquid chromatographic system coupled with a photodiode array detector and a single quadrupole mass spectrometer. A new prototype, consisting of a nano-liquid chromatography system coupled with an electron ionization mass spectrometer, was used for the characterization of the pure isolated molecules. Finally, due to the collection of highly pure nobiletin and tangeretin, the ability of 2-hydroxypropyl-β-cyclodextrin to enhance the water solubility of both polymethoxyflavones was evaluated by phase solubility studies and Job's plot method. PMID:27060470

  4. Size distribution of water-soluble components in particulate matter emitted from biomass burning

    NASA Astrophysics Data System (ADS)

    Park, Seung-Shik; Sim, Soo Young; Bae, Min-Suk; Schauer, James J.

    2013-07-01

    Size-resolved measurements of particulate matter (PM) emissions from 10 biomass materials (rice straw, soybean stem, green perilla stem, red pepper stem, pine needles, cherry leaves, cherry stem, maple leaves, gingko leaves and gingko stem) were conducted in a laboratory hood chamber environment using a 10-stage MOUDI. Samples were analyzed to determine the mass, water soluble organic carbon (WSOC), and water soluble inorganic species. This study examines how particle emissions and size distributions of chemical components vary with biomass materials. Mass fractions of water soluble organic mass (WSOM) (=1.6 × WSOC) and ionic species to the PM1.8 emissions varied significantly depending on the biomass type burned. The percent mass of WSOM in PM1.8 emissions ranged from 19.8% (green perilla stem) to 41.9% (red pepper stem) for agricultural crop residues, while the tree category accounted for 9.6% (gingko leaves) to 44.0% (gingko stem) of the PM1.8 emissions. Total ionic species contents in the PM1.8 mass ranged from 7.4% (rice straw) to 26.9% (green perilla stem) for the agricultural waste category, and 5.8% (maple leaves) to 23.5% (gingko stem) for the tree category. The ionic species fraction of the PM1.8 emission was dominated by K+, Cl-, and SO, while Ca2+ was important in the coarse mode particles (>3.1 μm). PM1.8 emissions of K+, Cl-, and SO were as high as 16.9%, 9.0%, and 5.8%, respectively, and were from the green perilla stem, red pepper stem, and gingko stem emissions. Normalized size distributions of mass, WSOC, K+, Cl-, SO, and oxalate in the biomass burning emissions showed a unimodal size distribution, peaking in the size ranges of 0.32-0.55 μm and 0.55-1.0 μm. Size-resolved PM mass fractions of WSOM, K+, Cl-, and SO showed fairly consistent distributions for each biomass type, with higher fractions in the ultrafine mode (<0.10 μm) and lower fractions in the accumulation mode of 0.32-1.0 μm. The size distributions of WSOC were strongly

  5. Preparation of starch macrocellular foam for increasing the dissolution rate of poorly water-soluble drugs.

    PubMed

    Zhao, Ying; Wu, Chao; Zhao, Zongzhe; Hao, Yanna; Xu, Jie; Yu, Tong; Qiu, Yang; Jiang, Jie

    2016-09-01

    Starch macrocellular foam (SMF), a novel natural bio-matrix material, was prepared by the hard template method in order to improve the dissolution rate and oral bioavailability of poorly water-soluble drugs. Nitrendipine (NDP) was chosen as a model drug and was loaded into SMF by the solvent evaporation method. SMF and the loaded SMF samples (NDP-SMF) were characterized by scanning electron microscopy, differential scanning calorimetry, X-ray powder diffraction and Fourier transform infrared spectroscopy. In vitro drug release studies showed that SMF significantly increased the dissolution rate of NDP. In vivo studies showed that the NDP-SMF tablets clearly increased the oral bioavailability of NDP in comparison with the reference commercial tablets. All the results obtained demonstrated that SMF was a promising carrier for the oral delivery of poor water-soluble drugs. PMID:26166407

  6. Chemical synthesis of water-soluble, chiral conducting-polymer complexes

    DOEpatents

    Wang, Hsing-Lin; McCarthy, Patrick A.; Yang, Sze Cheng

    2003-01-01

    The template-guided synthesis of water-soluble, chiral conducting polymer complexes is described. Synthesis of water-soluble polyaniline complexes is achieved by carefully controlling the experimental parameters such as; acid concentration, ionic strength, monomer/template ratio, total reagent concentration, and order of reagent addition. Chiral (helical) polyaniline complexes can be synthesized by addition of a chiral inducing agent (chiral acid) prior to polymerization, and the polyaniline helix can be controlled by the addition of the (+) or (-) form of the chiral acid. Moreover the quantity of chiral acid and the salt content has a significant impact on the degree of chirality in the final polymer complexes. The polyaniline and the template have been found to be mixed at the molecular level which results in chiral complexes that are robust through repeated doping and dedoping cycles.

  7. Bioavailability of water-soluble CoQ10 in beagle dogs.

    PubMed

    Prosek, Mirko; Butinar, Janos; Lukanc, Barbara; Fir, Maja Milivojevic; Milivojevic, Luka; Krizman, Mitja; Smidovnik, Andrej

    2008-08-01

    The bioavailability of a novel water-soluble inclusion complex of CoQ10, prepared in our laboratory was determined and compared with the bioavailability of commercially available oil-based form of CoQ10. Experimental work consisted of single dose comparative bioavailability study on seven beagle dogs, with a 14-day washout period between treatments. Identification and quantification of CoQ10 was done with HPLC-MS method using positive APCI ionization and SIM mode, M+ m/z 863.4. The bioavailability results confirm that the water-soluble formulation has nearly three times higher AUC(0-48 h), two times higher Cmax, and Tmax is shortened from 6 to 4 h. PMID:18495407

  8. Design of Chitosan and Its Water Soluble Derivatives-Based Drug Carriers with Polyelectrolyte Complexes

    PubMed Central

    Wu, Qing-Xi; Lin, Dong-Qiang; Yao, Shan-Jing

    2014-01-01

    Chitosan, the cationic polysaccharide derived from the natural polysaccharide chitin, has been studied as a biomaterial for more than two decades. As a polycationic polymer with favorable properties, it has been widely used to form polyelectrolyte complexes with polyanions for various applications in drug delivery fields. In recent years, a growing number of studies have been focused on the preparation of polyelectrolyte complexes based on chitosan and its water soluble derivatives. They have been considered well-suited as biomaterials for a number of vital drug carriers with targeted/controlled release profiles, e.g., films, capsules, microcapsules. In this work, an overview highlights not only the favorable properties of chitosan and its water soluble derivatives but also the good performance of the polyelectrolyte complexes produced based on chitosan. Their various types of applications as drug carriers are reviewed in detail. PMID:25532565

  9. Delivery of floxuridine derivatives to cancer cells by water-soluble organometallic cages.

    PubMed

    Yi, Jeong Wu; Barry, Nicolas P E; Furrer, Mona A; Zava, Olivier; Dyson, Paul J; Therrien, Bruno; Kim, Byeang Hyean

    2012-03-21

    The self-assembly of 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine (tpt) triangular panels with p-cymene (pPr(i)C(6)H(4)Me) ruthenium building blocks and 2,5-dioxydo-1,4-benzoquinonato (dobq) or 5,8-dioxydo-1,4-naphthoquinonato (donq) bridges, in the presence of a pyrenyl-nucleoside derivatives (pyreneR), affords the triangular prismatic host-guest compounds [(pyrene-R)⊂Ru(6)(pPr(i)C(6)H(4)Me)(6)(tpt)(2)(dobq)(3)](6+) ([(pyrene-R)⊂1](6+)) and [(pyrene-R)⊂Ru(6)(pPr(i)C(6)H(4)Me)(6)(tpt)(2)(donq)(3)](6+) ([(pyrene-R)⊂2](6+)), respectively. The inclusion of six monosubstitutedpyrenyl-nucleosides (pyrene-R1 = 5'-(1-pyrenyl butanoate)-2'-deoxyuridine, pyrene-R2 = 5-fluoro-5'-(1-pyrenyl butanoate)-2'-deoxyuridine, pyrene-R3 = 5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-glycyl}-2'-deoxyuridine, pyrene-R4 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-glycyl}-2'-deoxyuridine, pyrene-R5 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-phenylalanyl}-2'-deoxyvuridine, pyrene-R6 = 5-fluoro-5'-{N-[1-oxo-4-(1-pyrenyl)butyl]-phenylalanyl}-2'-deoxyuridine) has been accomplished. The carceplex nature of [(pyrene-R)⊂1](6+) with the pyrenyl moiety firmly encapsulated in the hydrophobic cavity of the cage with the nucleoside groups pointing outward was confirmed by NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS), while the host-guest nature of [(pyrene-R)⊂2](6+) was studied in solution by NMR techniques. In contrast to the floxuridine compounds used in the clinic, the host-guest complexes are highly water-soluble. Consequently, the cytotoxicities of these water-soluble compounds have been established using human ovarian A2780 and A2780cisR cancer cells. All the host-guest systems are more cytotoxic than the empty cages alone [1][CF(3)SO(3)](6) (IC(50) = 23 μM) and [2][CF(3)SO(3)](6) (IC(50) = 10 μM), the most active compound [pyrene-R4⊂1][CF(3)SO(3)](6)being 2 orders of magnitude more cytotoxic (IC(50) = 0.3 μM) on these human ovarian cancer cell lines (A2780 and A2780

  10. 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.

  11. Biosynthetic Studies on Water-Soluble Derivative 5c (DTX5c)

    PubMed Central

    Vilches, Tamara S.; Norte, Manuel; Daranas, Antonio Hernández; Fernández, José J.

    2012-01-01

    The dinoflagellate Prorocentrum belizeanum is responsible for the production of several toxins involved in the red tide phenomenon known as Diarrhetic Shellfish Poisoning (DSP). In this paper we report on the biosynthetic origin of an okadaic acid water-soluble ester derivative, DTX5c, on the basis of the spectroscopical analysis of 13C enriched samples obtained by addition of labelled sodium [l-13C], [2-13C] acetate to artificial cultures of this dinoflagellate. PMID:23170080

  12. Synthesis of Water-Soluble, Thiolate-Protected Gold Nanoparticles Uniform in Size.

    PubMed

    Azubel, Maia; Kornberg, Roger D

    2016-05-11

    By a modification of the method of Brust et al., water-soluble, thiolate-protected gold nanoparticles that are uniform in size were synthesized with no requirement for purification. The modification of the method was equilibration in the first step, which proved crucial for achieving size homogeneity. The thiol-to-gold ratio controlled the size of the particles, and the choice of thiol controlled the reactivity of the particles toward thiol exchange. PMID:27042759

  13. NASA Workmanship Hot Topics: Water Soluble Flux and ESD Charge Device Model

    NASA Technical Reports Server (NTRS)

    Plante, Jeannette F.

    2009-01-01

    This slide presentation reviews two topics of interest to NASA Workmanship: (1) Water Soluble Flux (WSF) and Electrostatic Discharge (ESD) safety. In the first topic, WSF, the presentation reviews voiding and the importance of cleanliness in using WSF for welding and soldering operations. The second topic reviews the NASA-HDBK-8739.21 for Human Body Model, and Machine Model safety methods, and challenges associated with the Charged Device Model (CDM)

  14. Quinlobelane: A water-soluble lobelane analogue and inhibitor of VMAT2

    PubMed Central

    Vartak, Ashish P.; Deaciuc, A. Gabriela; Dwoskin, Linda P.; Crooks, Peter A.

    2013-01-01

    Replacing the phenyl groups in the structure of the VMAT2 inhibitor, lobelane with either pyridyl, quinolyl or indolyl groups affords novel analogues with improved water solubility. The synthetic methodologies reported herein also underscore the paucity of hydrogenation methods that offer selectivity in the synthesis of the different classes of heteroaromatic lobelane analogues. The quinolyl group was the only replacement for the phenyl group in lobelane that retained VMAT2 inhibition. PMID:20494575

  15. Water-soluble rhamnose-coated Fe3O4 nanoparticles.

    PubMed

    Lartigue, Lenaic; Oumzil, Khalid; Guari, Yannick; Larionova, Joulia; Guérin, Christian; Montero, Jean-Louis; Barragan-Montero, Veronique; Sangregorio, Claudio; Caneschi, Andrea; Innocenti, Claudia; Kalaivani, T; Arosio, P; Lascialfari, A

    2009-07-16

    Water-soluble biocompatible rhamnose-coated Fe(3)O(4) nanoparticles of 4.0 nm are obtained by covalent anchorage of rhamnose on the nanoparticles surface via a phosphate linker. These nanoparticles present superparamagnetic behavior and nuclear relaxivities in the same order of magnitude as Endorem that make them potential magnetic resonance imaging (MRI) contrast agents of a second generation, where the saccharides represent also specific ligands able to target lectins on skin cells. PMID:19545163

  16. 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. PMID:20214530

  17. Multimodel Predictive System for Carbon Dioxide Solubility in Saline Formation Waters

    SciTech Connect

    Wang, Zan; Small, Mitchell J; Karamalidis, Athanasios K

    2013-02-05

    The prediction of carbon dioxide solubility in brine at conditions relevant to carbon sequestration (i.e., high temperature, pressure, and salt concentration (T-P-X)) is crucial when this technology is applied. Eleven mathematical models for predicting CO{sub 2} solubility in brine are compared and considered for inclusion in a multimodel predictive system. Model goodness of fit is evaluated over the temperature range 304–433 K, pressure range 74–500 bar, and salt concentration range 0–7 m (NaCl equivalent), using 173 published CO{sub 2} solubility measurements, particularly selected for those conditions. The performance of each model is assessed using various statistical methods, including the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC). Different models emerge as best fits for different subranges of the input conditions. A classification tree is generated using machine learning methods to predict the best-performing model under different T-P-X subranges, allowing development of a multimodel predictive system (MMoPS) that selects and applies the model expected to yield the most accurate CO{sub 2} solubility prediction. Statistical analysis of the MMoPS predictions, including a stratified 5-fold cross validation, shows that MMoPS outperforms each individual model and increases the overall accuracy of CO{sub 2} solubility prediction across the range of T-P-X conditions likely to be encountered in carbon sequestration applications.

  18. Water Solubility in Lower Mantle Minerals and the Role of Peridotite and Basalt in Water Storage in the Lower Mantle

    NASA Astrophysics Data System (ADS)

    Litasov, K.; Ohtani, E.

    2002-12-01

    Recent experimental and theoretical studies suggest water plays a key role in the geodynamics of the Earth's interior. Experimental data on water solubility in minerals of the Earth's mantle suggest that upper mantle, transition zone and lower mantle could have different potential to store water. Transition zone should be an important water reservoir due to significant water solubility in wadsleyite and ringwoodite (Mg,Fe)2SiO4. However, water storage capacity of lower mantle is still very controversial. Meade et al. (1994) reported results of in situ FTIR measurement of water solubility in MgSiO3-perovskite and suggest water content of 60 ppm. Bolfan-Casanova et al. (2000; 2002) showed absence of water (<1 ppm H2O) in MgSiO3-perovskite and 20 ppm H2O in magnesiowustite. In the contrary Murakami et al., 2002 measured 0.1-0.4 wt% H2O in peridotite-related Al-Fe-Mg-perovskite, 0.3-0.4 wt% H2O in Ca-perovskite and about 0.2 wt% H2O in magnesiowustite. Recently, we obtained data on phase relation in hydrous MORB at 20-26 GPa (Litasov and Ohtani, 2002) and found, that stability field of Al-Fe-Mg-perovskite shifts to the lower pressure. This fact suggests that these perovskites of exotic Fe-rich composition may also accommodate water. Our new FTIR data on water solubility in lower mantle minerals at 25 GPa and 1200-1600°C suggest water content in pure MgSiO3-perovskite is <90 ppm (bands at 3397, 3423, 3448, and 3482 cm-1). Water content in Al-Fe-Mg-perovskite (Al2O3=13-17 wt%; Mg#=58-61) observed in MORB is <100 ppm (bands at 3397 and 3423 cm-1). Water content in Al-Fe-Mg-perovskite (Al2O3=5-6 wt.%; Mg#=88-90) observed in peridotite is 1400-1800 ppm (band at 3397 cm-1). Water content in magnesiowustite (Mg0.8Fe0.2O) is 20-60 ppm (band at 3320 cm-1). Therefore, we confirmed that peridotite-related Mg-perovskite is a major water reservoir in the lower mantle; however role of Ca-perovskite and magnesiowustite is not clear. Using data on water solubility in Mg

  19. Synthesis of Water Soluble Camptothecin-Polyoxetane Conjugates via Click Chemistry

    PubMed Central

    Zolotarskaya, Olga Yu.; Wagner, Alison F.; Beckta, Jason M.; Valerie, Kristoffer; Wynne, Kenneth J.; Yang, Hu

    2012-01-01

    Water soluble camptothecin (CPT)-polyoxetane conjugates were synthesized using a clickable polymeric platform P(EAMO) that was made by polymerization of acetylene-functionalized 3-ethyl-3-hydroxymethyl oxetane (i.e., EAMO). CPT was first modified with a linker 6-azidohexanoic acid via an ester linkage to yield CPT-azide. CPT-azide was then click coupled to P(EAMO) in dichloromethane using bromotris(triphenylphosphine) copper(I)/N,N-diisopropylethylamine. For water solubility and cytocompatibility improvement, methoxypolyethylene glycol azide (mPEG-azide) was synthesized from mPEG 750 gmol−1 and click grafted using copper(II) sulfate and sodium ascorbate to P(EAMO)-g-CPT. 1H NMR spectroscopy confirmed synthesis of all intermediates and the final product P(EAMO)-g-CPT/PEG. CPT was found to retain its therapeutically active lactone form. The resulting P(EAMO)-g-CPT/PEG conjugates were water soluble and produced dose-dependent cytotoxicity to human glioma cells and increased γ-H2AX foci formation, indicating extensive cell cycle-dependent DNA damage. Altogether, we have synthesized CPT-polymer conjugates able to induce controlled toxicity to human cancer cells. PMID:23051100

  20. Synthesis of water soluble glycine capped silver nanoparticles and their surface selective interaction

    SciTech Connect

    Agasti, Nityananda; Singh, Vinay K.; Kaushik, N.K.

    2015-04-15

    Highlights: • Synthesis of water soluble silver nanoparticles at ambient reaction conditions. • Glycine as stabilizing agent for silver nanoparticles. • Surface selective interaction of glycine with silver nanoparticles. • Glycine concentration influences crystalinity and optical property of silver nanoparticles. - Abstract: Synthesis of biocompatible metal nanoparticles has been an area of significant interest because of their wide range of applications. In the present study, we have successfully synthesized water soluble silver nanoparticles assisted by small amino acid glycine. The method is primarily based on reduction of AgNO{sub 3} with NaBH{sub 4} in aqueous solution under atmospheric air in the presence of glycine. UV–vis spectroscopy, transmission electron microscopy (TEM), X–ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG) and differential thermal analysis (DTA) techniques used for characterization of resulting silver nanoparticles demonstrated that, glycine is an effective capping agent to stabilize silver nanoparticles. Surface selective interaction of glycine on (1 1 1) face of silver nanoparticles has been investigated. The optical property and crystalline behavior of silver nanoparticles were found to be sensitive to concentration of glycine. X–ray diffraction studies ascertained the phase specific interaction of glycine on silver nanoparticles. Silver nanoparticles synthesized were of diameter 60 nm. We thus demonstrated an efficient synthetic method for synthesis of water soluble silver nanoparticles capped by amino acid under mild reaction conditions with excellent reproducibility.

  1. Gastrointestinal effects associated with soluble and insoluble copper in drinking water.

    PubMed Central

    Pizarro, F; Olivares, M; Araya, M; Gidi, V; Uauy, R

    2001-01-01

    The aim of this study was to determine whether total copper or soluble copper concentration is associated with gastrointestinal signs and symptoms. Forty-five healthy adult women (18-55 years of age), living in Santiago, Chile, ingested tap water with 5 mg/L of copper containing different ratios of soluble copper (copper sulfate) and insoluble copper (copper oxide) over a 9-week period. Three randomized sequences of the different copper ratios (0:5, 1:4, 2:3, 3:2, and 5:0 mg/L) were followed. Subjects recorded their water consumption and gastrointestinal symptoms daily on a special form. Mean water consumption was similar among groups. Serum copper levels, ceruloplasmin, and activities of liver enzymes were within normal limits. No differences were detected between the means of biochemical parameters at the beginning and at the end of the study. Twenty subjects presented gastrointestinal disturbances at least once during the study, 9 suffered diarrhea (with or without abdominal pain and vomiting), and the other 11 subjects reported abdominal pain, nausea, or vomiting. No differences were found in incidence of abdominal pain, nausea, vomiting, and diarrhea regardless of the ratio of copper sulfate to copper oxide. In conclusion, both copper sulfate (a soluble compound) and copper oxide (an insoluble compound) have comparable effects on the induction of gastrointestinal manifestations, implying that similar levels of ionic copper were present in the stomach. PMID:11673125

  2. Abalone water-soluble matrix for self-healing biomineralization of tooth defects.

    PubMed

    Wen, Zhenliang; Chen, Jingdi; Wang, Hailiang; Zhong, Shengnan; Hu, Yimin; Wang, Zhili; Zhang, Qiqing

    2016-10-01

    Enamel cannot heal by itself if damaged. Hydroxyapatite (HAP) is main component of human enamel. Formation of enamel-like materials for healing enamel defects remains a challenge. In this paper, we successfully isolated the abalone water-soluble matrix (AWSM) with 1.53wt% the abalone water-soluble protein (AWSPro) and 2.04wt% the abalone water-soluble polysaccharide (AWSPs) from abandoned abalone shell, and self-healing biomineralization of tooth defects was successfully achieved in vitro. Based on X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), hot field emission scanning electron microscopy (HFESEM) and energy dispersive spectrometer (EDS) analysis, the results showed that the AWSM can efficiently induce remineralization of HAP. The enamel-like HAP was successfully achieved onto etched enamel's surface due to the presence of the AWSM. Moreover, the remineralized effect of eroded enamel was growing with the increase of the AWSM. This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shell, and we provides a new method for self-healing remineralization of enamel defects by AWSM and develops a novel dental material for potential clinical dentistry application. PMID:27287112

  3. Characterization of two water-soluble lignin metabolites with antiproliferative activities from Inonotus obliquus.

    PubMed

    Wang, Qingjie; Mu, Haibo; Zhang, Lin; Dong, Dongqi; Zhang, Wuxia; Duan, Jinyou

    2015-03-01

    The chaga mushroom, Inonotus obliquus has long been recognized as a remedy for cancer, gastritis, ulcers, and tuberculosis of the bones since the 16th century. Herein we reported the identification of two homogenous biological macromolecules, designated as IOW-S-1 and IOW-S-2 with anti-tumor activities from the hot-water extract of I. obliquus. Their molecular weights were determined to be 37.9 and 24.5kDa by high performance gel permeation chromatography (HPGPC) respectively. Chemical and spectral analysis indicated that both IOW-S-1 and IOW-S-2 were predominant in lignin, along with ∼20% carbohydrates. Examination of cytotoxicity showed that these two lignin-carbohydrate complexes induced cell death in a concentration dependent manner, while this apoptosis induction was largely cell-cycle independent. Further investigation demonstrated that IOW-S-1 or IOW-S-2 inhibited the activation of the nuclear transcription factor in cancer cells. These findings implied that soluble lignin derivatives were one of bioactive components in I. obliquus, and further provided insights into the understanding of molecular basis for diverse medicinal and nutritional values of this mushroom. PMID:25583019

  4. Aqueous solubility and octan-1-ol to water partition coefficients of aliphatic hydrocarbons

    SciTech Connect

    Coates, M.; Connell, D.W.; Barron, D.M.

    1985-07-01

    The aqueous solubility (S) and octanol-water partition coefficients (P) of homologous series of n-, 2-methyl-, and 3-methylalkanes, as well as 1-alkenes, have been determined by extrapolation of known results, direct measurement, and high-pressure liquid chromatography (HP-LC). Long-term equilibration experiments, used to reduce aggregate formation, indicated that n-dodecane and n-tetradecane have S values in agreement with those obtained by extrapolation of the data on lower members. HPLC data from reverse-phase columns further validated the use of extrapolation. By use of published values for P and S for lower n-alkanes, the relationships between log P, log S, and N/sub c/ were obtained. Cochromatography of n-alkanes with members of the other series then allowed these relationships to be determined for the 2- and 3-methylalkanes and the 1-alkenes. The derived S values were in reasonable agreement with values from previous work and those obtained by extrapolation. The log P values have not been previously determined for these compounds.

  5. Method for production of polymer and carbon nanofibers from water-soluble polymers.

    PubMed

    Spender, Jonathan; Demers, Alexander L; Xie, Xinfeng; Cline, Amos E; Earle, M Alden; Ellis, Lucas D; Neivandt, David J

    2012-07-11

    Nanometer scale carbon fibers (carbon nanofibers) are of great interest to scientists and engineers in fields such as materials science, composite production, and energy storage due to their unique chemical, physical, and mechanical properties. Precursors currently used for production of carbon nanofibers are primarily from nonrenewable resources. Lignin is a renewable natural polymer existing in all high-level plants that is a byproduct of the papermaking process and a potential feedstock for carbon nanofiber production. The work presented here demonstrates a process involving the rapid freezing of an aqueous lignin solution, followed by sublimation of the resultant ice, to form a uniform network comprised of individual interconnected lignin nanofibers. Carbonization of the lignin nanofibers yields a similarly structured carbon nanofiber network. The methodology is not specific to lignin; nanofibers of other water-soluble polymers have been successfully produced. This nanoscale fibrous morphology has not been observed in traditional cryogel processes, due to the relatively slower freezing rates employed compared to those achieved in this study. PMID:22716198

  6. Water-soluble benzylidene cyclopentanone based photosensitizers for in vitro and in vivo antimicrobial photodynamic therapy

    PubMed Central

    Fang, Yanyan; Liu, Tianlong; Zou, Qianli; Zhao, Yuxia; Wu, Feipeng

    2016-01-01

    Antimicrobial photodynamic therapy (aPDT) has been proposed to cope with the increasing antibiotic resistance among pathogens. As versatile pharmacophores, benzylidene cyclopentanone based photosensitizers (PSs) have been used in various bioactive materials. However, their reports as aPDT agents are very limited, and relationships between their chemical structures and antibacterial abilities have not been systematically discussed. Here, nine water-soluble benzylidene cyclopentanone PSs modified by polyethylene glycol (PEG), carboxylate anionic or pyridyl cationic agents are studied for aPDT. It is found that the binding/uptake abilities and aPDT effects of these PSs toward bacterial cells vary significantly when adjusting the number and position of their terminal charged groups. Though the comparable (also best) binding/uptake amounts are achieved by both cationic PS P3 and anionic PS Y1, only Y1 exhibits much more excellent aPDT activities than other PSs. Antibacterial mechanisms reveal that, relative to the favorable cell wall-binding of cationic PS P3, the anionic PS Y1 can accumulate more in the spheroplast/protoplast of methicillin-resistant Staphylococcus aureus (MRSA), which ensures its high efficient aPDT abilities both in vitro and in vivo. This study suggests the great clinical application potential of Y1 in inactivation of MRSA. PMID:27323899

  7. Synthesis of water-soluble dinuclear mn-porphyrin with multiple antioxidative activities.

    PubMed

    Kubota, Riku; Imamura, Shinya; Shimizu, Takahiko; Asayama, Shoichiro; Kawakami, Hiroyoshi

    2014-06-12

    Superoxide dismutase (SOD) and catalase activities of a drug are of great importance for its effective protection against reactive oxygen species (ROS)-induced injury. Achievement of catalase activity of a synthetic compound remains a challenge. Water-soluble Mn-porphyrins have high SOD and peroxynitrite (ONOO(-)) reducing activities, but not catalase-like activity. Herein, we are able to retain the fair SOD-like activity of a mononuclear Mn-5-(N-methylpyridinium-4-yl)-10,15,20-triphenyl porphyrin (MnM4PyP3P), while gaining in catalase-like activity with its dinuclear complex, 1,3-di[5-(N-methylene-pyridinium-4-yl)-10,15,20-triphenyl porphynato manganese] benzene tetrachloride (MnPD). Mechanistic study indicates that catalase-like activity of MnPD is due to synergism of two Mn active sites, where hydroxo-Mn(IV) complex is formed as an intermediate. The in vivo experiments demonstrate that MnPD significantly restores the treadmill-running ability of SOD-deficient mouse and thus indicates the therapeutic potential of MnPD. Furthermore, MnPD may serve as a mechanistic tool and indicate the new directions in the synthesis of catalase-like mimics. PMID:24944735

  8. New water soluble phosphonate and polycarboxylate complexants for enhanced f element separations

    SciTech Connect

    Nash, K.L.; Rickert, P.G.; Lessmann, E.P.; Mendoza, M.D.; Feil, J.F.; Sullivan, J.C.

    1994-08-01

    While lipophilic extractant molecules and ion exchange polymeric materials are clearly essential to efficient separation of metal ions by solvent extraction or ion exchange, the most difficult separations often could not be accomplished without the use of water soluble complexants. This report focuses on recent developments in design, synthesis and characterization of phosphonic acid and polycarboxylic acid ligands for enhanced f element separations. Emphasis is on the basic solution chemistry and crystal structures of complexes of the f elements with selected amino-derivatives of methanediphosphonic acid and with tetrahydrofuran-2,3,4,5-tetracarboxylic acid. The former series of compounds exhibit high affinity for lanthanides and actinides in acidic solutions. The latter ligand exhibits an unusual (and very useful) ``anti-selectivity`` for uranyl ion in a solvent extraction process, which permits efficient separation of uranyl from more radioactive components of nuclear wastes. Most of the observed effects can be explained through examination of the structure of the ligand, and comparison of the spectroscopic and thermodynamic parameters for complexation of various metal ions.

  9. Analysis of water-soluble ions and their precursor gases over diurnal cycle

    NASA Astrophysics Data System (ADS)

    Shon, Zang-Ho; Ghosh, Samik; Kim, Ki-Hyun; Song, Sang-Keun; Jung, Kweon; Kim, Nam-Jin

    2013-10-01

    A detailed description of an interactive relationship is made between water-soluble ionic components in PM2.5 and their precursor gases using the hourly resolution data measured at an urban monitoring site in Seoul during the year of 2010. Their diurnal variability was found to be correlated with their precursor gases (HNO3 and NH3). In the case of NO3- and NH4+, a close similarity was seen in their diurnal trends, especially during spring. There were no noticeable differences in the formation pathway of NO3-, SO42- , and NH4+ aerosols between day and night. For NO3- formation, heterogeneous hydrolysis of N2O5 might play a significant role in the nighttime enhancement of the oxidation rate. In addition, the concentrations of major anions (e.g. NO3-, SO42- , and Cl-) exhibited highly diverse seasonal patterns with their maximum values occurring in spring, summer, and winter, respectively. The overall results of this study suggest that the formation pathway of NO3- and SO42- aerosols should be regulated by a competing relationship between the NH3-lean (spring and winter) and NH3-rich conditions (summer and fall).

  10. Water-soluble chlorophyll protein is involved in herbivore resistance activation during greening of Arabidopsis thaliana

    PubMed Central

    Boex-Fontvieille, Edouard; Rustgi, Sachin; von Wettstein, Diter; Reinbothe, Steffen; Reinbothe, Christiane

    2015-01-01

    Water-soluble chlorophyll proteins (WSCPs) constitute a small family of unusual chlorophyll (Chl)-binding proteins that possess a Kunitz-type protease inhibitor domain. In Arabidopsis thaliana, a WSCP has been identified, named AtWSCP, that forms complexes with Chl and the Chl precursor chlorophyllide (Chlide) in vitro. AtWSCP exhibits a quite unexpected expression pattern for a Chl binding protein and accumulated to high levels in the apical hook of etiolated plants. AtWSCP expression was negatively light-regulated. Transgenic expression of AtWSCP fused to green fluorescent protein (GFP) revealed that AtWSCP is localized to cell walls/apoplastic spaces. Biochemical assays identified AtWSCP as interacting with RD21 (RESPONSIVE TO DESICCATION 21), a granulin domain-containing cysteine protease implicated in stress responses and defense. Reconstitution experiments showed tight interactions between RD21 and WSCP that were relieved upon Chlide binding. Laboratory feeding experiments with two herbivorous isopod crustaceans, Porcellio scaber (woodlouse) and Armadillidium vulgare (pillbug), identified the apical hook as Achilles’ heel of etiolated plants and that this was protected by RD21 during greening. Because Chlide is formed in the apical hook during seedling emergence from the soil, our data suggest an unprecedented mechanism of herbivore resistance activation that is triggered by light and involves AtWSCP. PMID:26016527

  11. Water-soluble chlorophyll protein is involved in herbivore resistance activation during greening of Arabidopsis thaliana.

    PubMed

    Boex-Fontvieille, Edouard; Rustgi, Sachin; von Wettstein, Diter; Reinbothe, Steffen; Reinbothe, Christiane

    2015-06-01

    Water-soluble chlorophyll proteins (WSCPs) constitute a small family of unusual chlorophyll (Chl)-binding proteins that possess a Kunitz-type protease inhibitor domain. In Arabidopsis thaliana, a WSCP has been identified, named AtWSCP, that forms complexes with Chl and the Chl precursor chlorophyllide (Chlide) in vitro. AtWSCP exhibits a quite unexpected expression pattern for a Chl binding protein and accumulated to high levels in the apical hook of etiolated plants. AtWSCP expression was negatively light-regulated. Transgenic expression of AtWSCP fused to green fluorescent protein (GFP) revealed that AtWSCP is localized to cell walls/apoplastic spaces. Biochemical assays identified AtWSCP as interacting with RD21 (responsive to desiccation 21), a granulin domain-containing cysteine protease implicated in stress responses and defense. Reconstitution experiments showed tight interactions between RD21 and WSCP that were relieved upon Chlide binding. Laboratory feeding experiments with two herbivorous isopod crustaceans, Porcellio scaber (woodlouse) and Armadillidium vulgare (pillbug), identified the apical hook as Achilles' heel of etiolated plants and that this was protected by RD21 during greening. Because Chlide is formed in the apical hook during seedling emergence from the soil, our data suggest an unprecedented mechanism of herbivore resistance activation that is triggered by light and involves AtWSCP. PMID:26016527

  12. Water-soluble benzylidene cyclopentanone based photosensitizers for in vitro and in vivo antimicrobial photodynamic therapy.

    PubMed

    Fang, Yanyan; Liu, Tianlong; Zou, Qianli; Zhao, Yuxia; Wu, Feipeng

    2016-01-01

    Antimicrobial photodynamic therapy (aPDT) has been proposed to cope with the increasing antibiotic resistance among pathogens. As versatile pharmacophores, benzylidene cyclopentanone based photosensitizers (PSs) have been used in various bioactive materials. However, their reports as aPDT agents are very limited, and relationships between their chemical structures and antibacterial abilities have not been systematically discussed. Here, nine water-soluble benzylidene cyclopentanone PSs modified by polyethylene glycol (PEG), carboxylate anionic or pyridyl cationic agents are studied for aPDT. It is found that the binding/uptake abilities and aPDT effects of these PSs toward bacterial cells vary significantly when adjusting the number and position of their terminal charged groups. Though the comparable (also best) binding/uptake amounts are achieved by both cationic PS P3 and anionic PS Y1, only Y1 exhibits much more excellent aPDT activities than other PSs. Antibacterial mechanisms reveal that, relative to the favorable cell wall-binding of cationic PS P3, the anionic PS Y1 can accumulate more in the spheroplast/protoplast of methicillin-resistant Staphylococcus aureus (MRSA), which ensures its high efficient aPDT abilities both in vitro and in vivo. This study suggests the great clinical application potential of Y1 in inactivation of MRSA. PMID:27323899

  13. Water-soluble Co(III) complexes of substituted phenanthrolines with cell selective anticancer activity.

    PubMed

    Jagadeesan, Sivaraman; Balasubramanian, Vimalkumar; Baumann, Patric; Neuburger, Markus; Häussinger, Daniel; Palivan, Cornelia G

    2013-11-01

    Transition metal complexes with substituted phenanthrolines as ligands represent potential anticancer products without the drawbacks of platinum complexes that are currently marketed. Here, we report the synthesis and cell selective anticancer activity of five new water-soluble Co(III) complexes with methyl substituted phenanthroline ligands. The complexes were characterized by elemental analysis, NMR, FAB-mass spectrometry, FTIR, electronic spectroscopy, and single crystal X-ray diffraction. Possible interaction of these complexes with DNA was assessed by a combination of circular dichroism, UV-vis spectroscopy titration, and ethidium bromide displacement assay, and the results indicated that DNA interaction is weak for these complexes. Cellular uptake and cytotoxicity of complexes at low concentrations were assessed by flow cytometry on PC-3 cells, while their effect on intracellular mitochondrial function was measured by MTS assay on HeLa and PC-3 cell lines. These complexes showed selective cytotoxicity with a significantly higher effect on intracellular mitochondrial function in PC-3 cells than in HeLa cells. At low concentrations, complex 2 had the highest cytotoxic effect on PC-3 cells, inducing around 38% cell death, and the correlation of cytotoxicity of these complexes to their hydrophobicity indicates that an appropriate value of the hydrophobicity is essential for high antitumor activity. PMID:24127683

  14. Susceptibility of representative dental pathogens to inactivation by the PDT with water-soluble photosensitizers

    NASA Astrophysics Data System (ADS)

    Angelov, Ivan; Mantareva, Vanya; Kussovski, Veselin; Worle, Diter; Kisov, Hristo; Belcheva, Marieta; Georgieva, Tzvetelina; Dimitrov, Slavcho

    2010-09-01

    In the recent decade the applications of photodynamic therapy (PDT) rapidly increase in several topics and one of areas where the PDT in the future will be play significant role is dentistry. The different photosensitizing complexes with a good water solubility and with absorption with an intensive maximum in the red region (630-690 nm), which makes them suitable for photodynamic treatments, were investigated. The photochemical properties of complexes for singlet oxygen generation were investigated and were shown relations between uptake levels and light intensity to achieve increase in photodynamic efficacy. Photodynamic efficacy against fungi Candida albicans and bacteria's E. faecalis, MRSA and S. Mutans in planktonic media was evaluated. The high photodynamic efficacy was shown for SiPc at very low concentrations (0.9 μM) and light doses of 50 J cm-2 by intensity of light 60 mW cm-2. The photodynamic response for E. faecalis, MRSA and S. Mutans, after treatments with different photosensitizers show strong dependence on concentrations of photsensitzers and micro organisms. The level of inactivation of the pathogen bacteria's from 1-2 degree of initial concentration up to full inactivation was observed. The studied complexes were compared to the recently studied Methylene blue, Haematoporphyrine and tetra-methylpirydiloxy Zn(II)- phthalocyanines and experimental results show that some of them have a good potential for inactivation of representative pathogenic bacterial strains. Experimental results also indicate that photodynamic therapy appears an effective method for inactivation of oral pathogenic bacterias and fungi.

  15. Susceptibility of representative dental pathogens to inactivation by the PDT with water-soluble photosensitizers

    NASA Astrophysics Data System (ADS)

    Angelov, Ivan; Mantareva, Vanya; Kussovski, Veselin; Worle, Diter; Kisov, Hristo; Belcheva, Marieta; Georgieva, Tzvetelina; Dimitrov, Slavcho

    2011-02-01

    In the recent decade the applications of photodynamic therapy (PDT) rapidly increase in several topics and one of areas where the PDT in the future will be play significant role is dentistry. The different photosensitizing complexes with a good water solubility and with absorption with an intensive maximum in the red region (630-690 nm), which makes them suitable for photodynamic treatments, were investigated. The photochemical properties of complexes for singlet oxygen generation were investigated and were shown relations between uptake levels and light intensity to achieve increase in photodynamic efficacy. Photodynamic efficacy against fungi Candida albicans and bacteria's E. faecalis, MRSA and S. Mutans in planktonic media was evaluated. The high photodynamic efficacy was shown for SiPc at very low concentrations (0.9 μM) and light doses of 50 J cm-2 by intensity of light 60 mW cm-2. The photodynamic response for E. faecalis, MRSA and S. Mutans, after treatments with different photosensitizers show strong dependence on concentrations of photsensitzers and micro organisms. The level of inactivation of the pathogen bacteria's from 1-2 degree of initial concentration up to full inactivation was observed. The studied complexes were compared to the recently studied Methylene blue, Haematoporphyrine and tetra-methylpirydiloxy Zn(II)- phthalocyanines and experimental results show that some of them have a good potential for inactivation of representative pathogenic bacterial strains. Experimental results also indicate that photodynamic therapy appears an effective method for inactivation of oral pathogenic bacterias and fungi.

  16. Super Aryl-Extended Calix[4]pyrroles: Synthesis, Binding Studies, and Attempts To Gain Water Solubility.

    PubMed

    Escobar, Luis; Aragay, Gemma; Ballester, Pablo

    2016-09-12

    We describe the synthesis of unprecedented calix[4]pyrrole receptors featuring "super aryl extended" (SAE) cavities. We elaborated the aromatic cavity provided by the αααα-isomer of para-tetraiodo-meso-phenyl calix[4]pyrrole by installing ethynyl-aryl substituents at its upper rim. We report the binding properties of the prepared SAE-calix[4]pyrrole tetraester towards pyridyl-N-oxides. The binding data revealed the formation of thermodynamically and kinetically highly stable 1:1 complexes. The complexation-induced chemical shifts indicated the formation of hydrogen bonds and aromatic interactions with the calix-core adopting the cone conformation. We quantified the additional interactions established between the four terminal aryl groups and the para-phenyl substituent of 4-phenyl pyridine N-oxide to be in the order of 1 kcal mol(-1) . The complex formation rate was found to be close to the diffusion control suggesting that the free host adopted a 1,3-alternate conformation. Finally, we attempted to gain water solubility of SAE-calix[4]pyrroles using derivatives that display four ionizable or charged groups at their upper rims. PMID:27505617

  17. Using FGD gypsum to remove soluble phosphorus from agricultural drainage waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After several decades of applying chicken litter to meet crop demands for nitrogen, high levels of legacy phosphorus (P) in soils of the Delmarva Peninsula are a major source of soluble P entering drainage ditches that empty to the Chesapeake Bay. In April, 2007, Flue Gas Desulfurization (FGD) gypsu...

  18. An accurate formulation of the solubility of Co{sub 2} in water, for geothermal applications

    SciTech Connect

    Iglesias, Eduardo R.; Moya, Sara L.

    1992-01-01

    The solubility correlations for the H{sub 2}O-CO{sub 2} system applied so far for numerical simulation of geothermal reservoir and well flows are crude. This is due, at least partly, to the significant disagreement existing between the solubility models and results published in the specialized literature. In this work we analyze the reasons underlying this disagreement. On this basis, we propose a thermodynamically correct, and numerically accurate model for the solubility of carbon dioxide in water. Its range of validity is up to 350 C and 500 bar. Our main contributions are: (a) the adoption of an equation of state for the gas phase that realistically accounts for the non-ideal behavior of both components and that of the mixture, within the P-T range considered; and (b) to accurately include the effects of temperature and pressure on the solubility of carbon dioxide in the liquid phase. The proposed model fits the available phase equilibrium data for the H{sub 2}O-CO{sub 2} system nicely. In particular, it does not present the severe conflict between the linearity of the model and the lack of linearity of the data, evident in earlier models. The tight fit obtained with our model indicates that the complexities of H{sub 2}-CO{sub 2} phase equilibrium are well represented by it.

  19. Molecular dynamics study of salt–solution interface: Solubility and surface charge of salt in water

    SciTech Connect

    Kobayashi, Kazuya; Liang, Yunfeng E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Matsuoka, Toshifumi E-mail: matsuoka@earth.kumst.kyoto-u.ac.jp; Sakka, Tetsuo

    2014-04-14

    The NaCl salt–solution interface often serves as an example of an uncharged surface. However, recent laser-Doppler electrophoresis has shown some evidence that the NaCl crystal is positively charged in its saturated solution. Using molecular dynamics (MD) simulations, we have investigated the NaCl salt–solution interface system, and calculated the solubility of the salt using the direct method and free energy calculations, which are kinetic and thermodynamic approaches, respectively. The direct method calculation uses a salt–solution combined system. When the system is equilibrated, the concentration in the solution area is the solubility. In the free energy calculation, we separately calculate the chemical potential of NaCl in two systems, the solid and the solution, using thermodynamic integration with MD simulations. When the chemical potential of NaCl in the solution phase is equal to the chemical potential of the solid phase, the concentration of the solution system is the solubility. The advantage of using two different methods is that the computational methods can be mutually verified. We found that a relatively good estimate of the solubility of the system can be obtained through comparison of the two methods. Furthermore, we found using microsecond time-scale MD simulations that the positively charged NaCl surface was induced by a combination of a sodium-rich surface and the orientation of the interfacial water molecules.

  20. Film-coated matrix mini-tablets for the extended release of a water-soluble drug.

    PubMed

    Mohamed, Faiezah A A; Roberts, Matthew; Seton, Linda; Ford, James L; Levina, Marina; Rajabi-Siahboomi, Ali R

    2015-04-01

    Extended release (ER) of water-soluble drugs from hydroxypropylmethylcellulose (HPMC) matrix mini-tablets (mini-matrices) is difficult to achieve due to the large surface area to volume ratio of the mini matrices. Therefore, the aims of this study were to control the release of a water-soluble drug (theophylline) from mini-matrices by applying ER ethylcellulose film coating (Surelease®), and to assess the effects of Surelease®:pore former (Opadry®) ratio and coating load on release rates. Mini-matrices containing 40%w/w HPMC K100M CR were coated with 100:0, 85:15, 80:20, 75:25 or 70:30 Surelease®:Opadry® to different coating weight gains (6-20%). Non-matrix mini-tablets were also produced and coated with 80:20 Surelease®:Opadry® to different coating weight gains. At low coating weight gains, nonmatrix mini-tablets released the entire drug within 0.5 h, while at high coating weight gains only a very small amount (<5%) of drug was released after 12 h. The gel formation of HPMC prevented disintegration of mini-matrices at low coating weight gains but contributed to rupture of the film even at high coating weight gains. As a result, drug release from mini-matrices was slower than that from nonmatrix mini-tablets at low coating weight gains, yet faster at high coating weight gains. An increase in the lag time of drug release from mini-matrices was observed as the concentration of Opadry® reduced or the coating weight gain increased. This study has demonstrated the possibility of extending the release of a water-soluble drug from HPMC mini-matrices by applying ER film coating with appropriate levels of pore former and coating weight gains to tailor the release rate. PMID:24564797

  1. Fuels production by photoelectrolysis of water and photooxidation of soluble biomass materials

    SciTech Connect

    Sammells, A.F.; St. John, M.R.

    1984-03-20

    A process and apparatus for production of fuels by photoelectrolysis of water and photooxidation of water soluble biomass and a process for preparation of Schottky-type metalized, appropriately doped n-type semiconductor photochemical diodes suitable for use in the above process and apparatus. The production of hydrogen by photoelectrolysis of water as the cathodic reaction of an optically illuminated photochemical diode is effected in an aqueous electrolyte which comprises a biomass product which may be monosaccharides, polysaccharides, lignins, their partially oxidized products, and mixtures thereof which are oxidized as the anodic reaction of the photochemical diode producing liquid fuels and useful chemicals. Molecular oxygen evolution is avoided and utilization of biomass product provides a cost effective material to increase fuels and useful chemical production by photoelectrolysis of water at potentials substantially less than required for normal water electrolysis involving oxygen evolution.

  2. Oil-soluble and water-soluble BTPhens and their europium complexes in octanol/water solutions: interface crossing studied by MD and PMF simulations.

    PubMed

    Benay, G; Wipff, G

    2013-01-31

    Bistriazinyl-phenantroline "BTPhen" ligands L display the remarkable feature to complex trivalent lanthanide and actinide ions, with a marked selectivity for the latter. We report on molecular dynamics studies of tetrasubstituted X(4)BTPhens: L(4+) (X = (+)Et(3)NCH(2)-), L(4-) (X = (-)SO(3)Ph-), and L(0) (X = CyMe(4)) and their complexes with Eu(III) in binary octanol/water solutions. Changes in free energies upon interface crossing are also calculated for typical solutes by potential of mean force PMF simulations. The ligands and their complexes partition, as expected, to either the aqueous or the oil phase, depending on the "solubilizing" group X. Furthermore, most of them are found to be surface active. The water-soluble L(4+) and L(4-) ligands and their (L)Eu(NO(3))(3) complexes adsorb at the aqueous side of the interface, more with L(4-) than with L(4+). The oil soluble ligand L(0) is not surface active in its endo-endo form but adsorbs on the oil side of the interface in its most polar endo-exo form, as well as in its protonated L(0)H(+) and complexed (L(0))Eu(NO(3))(3) states. Furthermore, comparing PMFs of the Eu(III) complexes with and without nitric acid shows that acidifying the aqueous phase has different effects, depending on the ligand charge. In particular, acid promotes the Eu(III) extraction by L(0) via the (L(0))(2)Eu(NO(3))(2+) complex, as observed experimentally. Overall, the results point to the importance of interfacial adsorption for the liquid-liquid extraction of trivalent lanthanide and actinide cations by BTPhens and analogues. PMID:23293892

  3. Modeling of the hydrophobic microenvironment of water-soluble molybdoenzymes in an aqueous micellar solution.

    PubMed

    Hasenaka, Yuki; Okamura, Taka-aki; Onitsuka, Kiyotaka

    2015-07-28

    A toluene-soluble molybdenum(vi) complex containing a bulky hydrophobic substituent, (Et4N)2[Mo(VI)O2{1,2-S2-3,6-(RCONH)2C6H2}2] (R = (4-(t)BuC6H4)3C), was dissolved in the hydrophobic core of a micelle in an aqueous medium and catalyzed the biomimetic reduction of an amine N-oxide by an NADH analog. The kinetic isotope effect of solvent water clearly indicates that water molecules are essential for catalysis and are involved in the rate-determining step. PMID:26076318

  4. Water-soluble chelating polymers for removal of actinides from watewater

    SciTech Connect

    Jarvinen, G.

    1996-10-01

    Polymer filtration is a technology being developed to recover valuable or regulated metal ions selectively from process or wastewaters. Water-soluble chelating polymers are specially designed to bind selectively with metal ions in aqueous solutions. The polymers molecular weight is large enough so they can be separated and concentrated using available ultrafiltration technology. Water and smaller unbound components of the solution pass freely through the ultrafiltration membrane. The polymers can then be reused by changing the solution conditions to release the metal ions, which are recovered in concentrated form, for recycle or disposal.

  5. In vitro and in vivo antioxidant activity of a water-soluble polysaccharide from dendrobium denneanum

    USGS Publications Warehouse

    Luo, A.; Ge, Z.; Fan, Y.; Chun, Z.; Jin, He X.

    2011-01-01

    The water-soluble crude polysaccharide (DDP) obtained from the aqueous extracts of the stem of Dendrobium denneanum through hot water extraction followed by ethanol precipitation, was found to have an average molecular weight (Mw) of about 484.7 kDa. Monosaccharide analysis revealed that DDP was composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.66:8.92:34.20:10.16. The investigation of antioxidant activity both in vitro and in vivo showed that DDP is a potential antioxidant. ?? 2011.

  6. Balanced charge injection in multilayer polymer light-emitting diode with water soluble nonconjugated polymer dispersed by ionic compounds

    NASA Astrophysics Data System (ADS)

    Park, Dong-Kyu; Chun, A.-Rum; Kim, Soo-Hong; Kim, Min-Sook; Kim, Choong-Gi; Kwon, Tae-Woo; Cho, Seong-Jin; Woo, Hyung-Suk; Lee, Jae-Gyoung; Lee, Suck-Hyun; Guo, Zhi-Xin

    2007-07-01

    The authors have fabricated highly efficient polymeric light-emitting diode (PLED) from ionic compound dispersed water soluble nonconjugated polymer, polyurethane (PU), which was used as an ultrathin hole blocking and electron injection layer (HB-EIL) on the top of commercially available blue-emitting polymer, polyfluorene. The device with HB-EIL showed a maximum quantum efficiency of 1.7%, while the one without HB-EIL showed an efficiency of 0.6%. They propose that the better performance in PLED with PU layer was due to a well balanced charge injection in emitting layer after the enhanced electron injection due to ionic compound in the insulating PU layer.

  7. Fructans and other water soluble carbohydrates in vegetative organs and fruits of different Musa spp. accessions

    PubMed Central

    Cruz-Cárdenas, Carlos I.; Miranda-Ham, María L.; Castro-Concha, Lizbeth A.; Ku-Cauich, José R.; Vergauwen, Rudy; Reijnders, Timmy; Van den Ende, Wim; Escobedo-GraciaMedrano, Rosa M.

    2015-01-01

    The water soluble carbohydrates (WSC) glucose, fructose, and sucrose are well-known to the great public, but fructans represent another type of WSC that deserves more attention given their prebiotic and immunomodulatory properties in the food context. Although the occurrence of inulin-type fructo-oligosaccharides (FOS) was proposed in the fruit of some banana accessions, little or no information is available neither on the exact identity of the fructan species, nor on the fructan content in different parts of banana plants and among a broader array of banana cultivars. Here, we investigated the WSC composition in leaves, pulp of ripe fruits and rhizomes from mature banana plants of 11 accessions (I to XI), including both cultivated varieties and wild Musa species. High performance anion exchange chromatography with integrated pulsed amperometric detection (HPAEC-IPAD) showed the presence of 1-kestotriose [GF2], inulobiose [F2], inulotriose [F3], 6-kestotriose and 6G-kestotriose (neokestose) fructan species in the pulp of mature fruits of different accessions, but the absence of 1,1-nystose and 1,1,1 kestopentaose and higher degree of polymerization (DP) inulin-type fructans. This fructan fingerprint points at the presence of one or more invertases that are able to use fructose and sucrose as alternative acceptor substrates. Quantification of glucose, fructose, sucrose and 1-kestotriose and principal component analysis (PCA) identified related banana groups, based on their specific WSC profiles. These data provide new insights in the biochemical diversity of wild and cultivated bananas, and shed light on potential roles that fructans may fulfill across species, during plant development and adaptation to changing environments. Furthermore, the promiscuous behavior of banana fruit invertases (sucrose and fructose as acceptor substrates besides water) provides a new avenue to boost future work on structure-function relationships on these enzymes, potentially leading to

  8. Fructans and other water soluble carbohydrates in vegetative organs and fruits of different Musa spp. accessions.

    PubMed

    Cruz-Cárdenas, Carlos I; Miranda-Ham, María L; Castro-Concha, Lizbeth A; Ku-Cauich, José R; Vergauwen, Rudy; Reijnders, Timmy; Van den Ende, Wim; Escobedo-GraciaMedrano, Rosa M

    2015-01-01

    The water soluble carbohydrates (WSC) glucose, fructose, and sucrose are well-known to the great public, but fructans represent another type of WSC that deserves more attention given their prebiotic and immunomodulatory properties in the food context. Although the occurrence of inulin-type fructo-oligosaccharides (FOS) was proposed in the fruit of some banana accessions, little or no information is available neither on the exact identity of the fructan species, nor on the fructan content in different parts of banana plants and among a broader array of banana cultivars. Here, we investigated the WSC composition in leaves, pulp of ripe fruits and rhizomes from mature banana plants of 11 accessions (I to XI), including both cultivated varieties and wild Musa species. High performance anion exchange chromatography with integrated pulsed amperometric detection (HPAEC-IPAD) showed the presence of 1-kestotriose [GF2], inulobiose [F2], inulotriose [F3], 6-kestotriose and 6G-kestotriose (neokestose) fructan species in the pulp of mature fruits of different accessions, but the absence of 1,1-nystose and 1,1,1 kestopentaose and higher degree of polymerization (DP) inulin-type fructans. This fructan fingerprint points at the presence of one or more invertases that are able to use fructose and sucrose as alternative acceptor substrates. Quantification of glucose, fructose, sucrose and 1-kestotriose and principal component analysis (PCA) identified related banana groups, based on their specific WSC profiles. These data provide new insights in the biochemical diversity of wild and cultivated bananas, and shed light on potential roles that fructans may fulfill across species, during plant development and adaptation to changing environments. Furthermore, the promiscuous behavior of banana fruit invertases (sucrose and fructose as acceptor substrates besides water) provides a new avenue to boost future work on structure-function relationships on these enzymes, potentially leading to

  9. Ubiquitous Water-Soluble Molecules in Aquatic Plant Exudates Determine Specific Insect Attraction

    PubMed Central

    Sérandour, Julien; Reynaud, Stéphane; Willison, John; Patouraux, Joëlle; Gaude, Thierry; Ravanel, Patrick; Lempérière, Guy; Raveton, Muriel

    2008-01-01

    Plants produce semio-chemicals that directly influence insect attraction and/or repulsion. Generally, this attraction is closely associated with herbivory and has been studied mainly under atmospheric conditions. On the other hand, the relationship between aquatic plants and insects has been little studied. To determine whether the roots of aquatic macrophytes release attractive chemical mixtures into the water, we studied the behaviour of mosquito larvae using olfactory experiments with root exudates. After testing the attraction on Culex and Aedes mosquito larvae, we chose to work with Coquillettidia species, which have a complex behaviour in nature and need to be attached to plant roots in order to obtain oxygen. This relationship is non-destructive and can be described as commensal behaviour. Commonly found compounds seemed to be involved in insect attraction since root exudates from different plants were all attractive. Moreover, chemical analysis allowed us to identify a certain number of commonly found, highly water-soluble, low-molecular-weight compounds, several of which (glycerol, uracil, thymine, uridine, thymidine) were able to induce attraction when tested individually but at concentrations substantially higher than those found in nature. However, our principal findings demonstrated that these compounds appeared to act synergistically, since a mixture of these five compounds attracted larvae at natural concentrations (0.7 nM glycerol, <0.5 nM uracil, 0.6 nM thymine, 2.8 nM uridine, 86 nM thymidine), much lower than those found for each compound tested individually. These results provide strong evidence that a mixture of polyols (glycerol), pyrimidines (uracil, thymine), and nucleosides (uridine, thymidine) functions as an efficient attractive signal in nature for Coquillettidia larvae. We therefore show for the first time, that such commonly found compounds may play an important role in plant-insect relationships in aquatic eco-systems. PMID:18841203

  10. IUPAC-NIST Solubility Data Series. 91. Phenols with Water. Part 1. C6 and C7 Phenols with Water and Heavy Water

    NASA Astrophysics Data System (ADS)

    Góral, Marian; Shaw, David G.; Måczyński, Andrzej; Wiśniewska-Gocłowska, Barbara

    2011-09-01

    The mutual solubilities and related liquid-liquid equilibria of nine binary systems of C6 and C7 phenols with water are exhaustively and critically reviewed. Reports of experimental determination of solubility that appeared in the primary literature prior to the end of 2009 are compiled. For four systems, sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units.

  11. Chemical stability limits of water-soluble polymers used in oil recovery processes

    SciTech Connect

    Ryles, R.G.

    1988-02-01

    This work describes long-term thermal stability limits of water-soluble polymers under anaerobic conditions. Polymers investigated included polyacrylamide, xanthan, scleroglucan, cellulose sulfate, and a heteropolysaccharide of unknown structure. The primary mechanism of polyacrylamide degradation was found to be amide group hydrolysis. Interaction between hydrolyzed polyacrylamide and divalent metal ions present in solution caused significant losses in solution viscosity, and phase separation ultimately occurred in extreme conditions of high degrees of hydrolysis or high concentrations of divalent ions. The rate of hydrolysis was found to depend mostly on temperature. At 50/sup 0/C (122/sup 0/F), the rate was quite slow and polyacrylamide solutions were stable for many months, even in the presence of high concentrations of divalent ions. At 60 to 70/sup 0/C (140 to 158/sup 0/F), the rate of hydrolysis was moderate and the rate of viscosity loss depended on the precise temperature and divalent ion concentration. At 90/sup 0/C (194/sup 0/F), hydrolysis was rapid and polyacrylamide solutions were stable to precipitation only when the divalent ion concentration was less than about 200 ppm. When the divalent ion concentration was zero, solution viscosity increased because of a further expansion of the polyelectrolyte coil. The stability of xanthan was determined primarily by temperature and was independent of divalent ions. Although performance varies from xanthan to xanthan, the useful limit was generally found to be <70/sup 0/C (<158/sup 0/F). Viscosity retention was also found to be extremely shear-rate dependent. Other naturally occurring polymers exhibited variable performance. In alkaline brines, polyacrylamides were stable up to 90/sup 0/C (194/sup 0/F) for long periods of time, whereas xanthan was degraded at >50/sup 0/C (>122/sup 0/F).al

  12. Nanoemulsion-based delivery systems for poorly water-soluble bioactive compounds: Influence of formulation parameters on Polymethoxyflavone crystallization

    PubMed Central

    Li, Yan; Zheng, Jinkai; Xiao, Hang; McClements, David Julian

    2012-01-01

    Polymethoxyflavones (PMFs) extracted from citrus peel exhibit potent anti-cancer activity, but are highly hydrophobic molecules with poor solubility in both water and oil at ambient and body temperature, which limits their bioavailability. The possibility of encapsulating PMFs within nanoemulsion-based delivery systems to facilitate their application in nutraceutical and pharmaceutical products was investigated. The influence of oil type (corn oil, MCT, orange oil), emulsifier type (β-lactoglobulin, lyso-lecithin, Tween, and DTAB), and neutral cosolvents (glycerol and ethanol) on the formation and stability of PMF-loaded nanoemulsions was examined. Nanoemulsions (r < 100 nm) could be formed using high pressure homogenization for all emulsifier types, except DTAB. Lipid droplet charge could be altered from highly cationic (DTAB), to near neutral (Tween), to highly anionic (β-lactoglobulin, lyso-lecithin) by varying emulsifier type. PMF crystals formed in all nanoemulsions after preparation, which had a tendency to sediment during storage. The size, morphology, and aggregation of PMF crystals depended on preparation method, emulsifier type, oil type, and cosolvent addition. These results have important implications for the development of delivery systems for bioactive components that have poor oil and water solubility at application temperatures. PMID:22685367

  13. Nanoemulsion-based delivery systems for poorly water-soluble bioactive compounds: Influence of formulation parameters on Polymethoxyflavone crystallization.

    PubMed

    Li, Yan; Zheng, Jinkai; Xiao, Hang; McClements, David Julian

    2012-06-01

    Polymethoxyflavones (PMFs) extracted from citrus peel exhibit potent anti-cancer activity, but are highly hydrophobic molecules with poor solubility in both water and oil at ambient and body temperature, which limits their bioavailability. The possibility of encapsulating PMFs within nanoemulsion-based delivery systems to facilitate their application in nutraceutical and pharmaceutical products was investigated. The influence of oil type (corn oil, MCT, orange oil), emulsifier type (β-lactoglobulin, lyso-lecithin, Tween, and DTAB), and neutral cosolvents (glycerol and ethanol) on the formation and stability of PMF-loaded nanoemulsions was examined. Nanoemulsions (r < 100 nm) could be formed using high pressure homogenization for all emulsifier types, except DTAB. Lipid droplet charge could be altered from highly cationic (DTAB), to near neutral (Tween), to highly anionic (β-lactoglobulin, lyso-lecithin) by varying emulsifier type. PMF crystals formed in all nanoemulsions after preparation, which had a tendency to sediment during storage. The size, morphology, and aggregation of PMF crystals depended on preparation method, emulsifier type, oil type, and cosolvent addition. These results have important implications for the development of delivery systems for bioactive components that have poor oil and water solubility at application temperatures. PMID:22685367

  14. Interfacial self-assembly of water-soluble cationic porphyrins for the reduction of oxygen to water.

    PubMed

    Olaya, Astrid J; Schaming, Delphine; Brevet, Pierre-Francois; Nagatani, Hirohisa; Xu, Hai-Jun; Meyer, Michel; Girault, Hubert H

    2012-06-25

    Meet at the border: Assembly of the water-soluble cobalt tetrakis(N-methylpyridinium-4-yl)porphyrin [CoTMPyP](4+) at soft interfaces is enhanced and stabilized by its interfacial interaction with the lipophilic anion (C(6)F(5))(4)B(-). The supramolecular structure thus formed provides excellent catalytic activity in the four-electron reduction of oxygen. PMID:22615211

  15. Computing gas solubility in reservoir waters for environmental chemistry applications: the role of satellite observations

    NASA Astrophysics Data System (ADS)

    Rosa, R.; Lima, I.; Ramos, F.; Bambace, L.; Assireu, A.; Stech, J.; Novo, E.; Lorenzeti, L.

    Atmospheric greenhouse gases concentration has increased during the past centuries basically due to biogenic and pyrogenic anthopogenic emissions Recent investigations have shown that gas emission methane as an important example from tropical hydroelectric reservoirs may comprise a considerable fraction of the total anthropogenic bulk In order to evaluate the concentration of gases of potential importance in environmental chemistry the solubility of such gases have been collected and converted into a uniform format using the Henry s law which states that the solubility of a gas in a liquid is directly proportional to its partial pressure However the Henry s law can be derived as a function of temperature density molar mixing ratio in the aqueous phase and molar mass of water In this paper we show that due to the complex temperature variation and water composition measured in brazilian tropical reservoirs as Serra da Mesa and Manso expressive secular variation on the traditional solubility constants concentration of a species in the aqueous phase by the partial pressure of that species in the gas phase can change in a rate of approximately 30 in 6 decades This estimation comes from a computational analysis of temperature variation measured during 6 months in Serra da Mesa and Manso reservoirs taking into account a simulated density and molar mass variation of the aqueous composition in these environments As an important global change issue from this preliminary analysis we discuss its role in the current estimations on the concentration emission rates

  16. Characterization of the water soluble component of inedible residue from candidate CELSS crops

    NASA Technical Reports Server (NTRS)

    Garland, Jay

    1992-01-01

    Recycling of inorganic nutrients required for plant growth will be a necessary component of a fully closed, bioregenerative life support system. This research characterized the recovery of plant nutrients from the inedible fraction of three crop types (wheat, potato, and soybean) by soaking, or leaching, in water. A considerable portion of the dry weight of the inedible biomass was readily soluble (29 percent for soybean, 43 percent for wheat, and 52 percent for potato). Greater weight loss from potato was a result of higher tissue concentrations of potassium, nitrate, and phosphate. Approximately 25 percent of the organic content of the biomass was water soluble, while the majority of most inorganic nutrients, except for calcium and iron, were recovered in the leachate. Direct use of the leachates in hydroponic media could provide between 40-90 percent of plant nutrient demands for wheat, and 20-50 percent of demand for soybean and potato. Further evaluation of leaching as a component of resource recovery scheme in a bioregenerative system requires study of (1) utilization of plant leachates in hydroponic plant culture; and (2) conversion of organic material (both soluble and insoluble) into edible, or other useful, products.

  17. Effect of glycosylation with xylose on the mechanical properties and water solubility of peanut protein films.

    PubMed

    Lin, Wei-Jing; Liu, Hong-Zhi; Shi, Ai-Min; Liu, Li; Wang, Qiang; Adhikari, Benu

    2015-10-01

    This study aimed at improving the mechanical properties and water solubility of peanut protein isolate (PPI) films by glycosylating with xylose (X). The modification process of glycosylation was optimized by using response surface methodology (RSM). The effects of pH, temperature and time on degrees of glycosylation (DG), tensile strength (TS), elongation (E), solubility and microstructure of xylose glycosylated PPI films (PPI-XF) were determined. The changes of DG in different conditions indicated that crosslinking should occur between PPI and xylose during the modification. Optimum glycosylation conditions were found to be pH 9.5, 91.5 °C and 95 min. Under these conditions, TS and E values of PPI-XF were 10.37 MPa and 96.47 %, respectively. Due to glycosylation, solubility of PPI-XF decreased from 96.64 to 35.94 % and these films remained intact in water for 24 h. The microstructure of PPI-XF was denser and more compact than the unmodified PPI films. These results suggest that the xylose glycosylated PPI films have potentiality of being used as biodegradable films in food packaging application. PMID:26396370

  18. Targeted delivery of a poorly water-soluble compound to hair follicles using polymeric nanoparticle suspensions.

    PubMed

    Morgen, Michael; Lu, Guang Wei; Du, Daniel; Stehle, Randall; Lembke, Franz; Cervantes, Jessica; Ciotti, Susan; Haskell, Roy; Smithey, Dan; Haley, Kevin; Fan, Conglin

    2011-09-15

    This study explored the utility of topically applied polymeric nanoparticle suspensions to target delivery of poorly water-soluble drugs to hair follicles. Several formulations of amorphous drug/polymer nanoparticles were prepared from ethyl cellulose and UK-157,147 (systematic name (3S,4R)-[6-(3-hydroxyphenyl)sulfonyl]-2,2,3-trimethyl-4-(2-methyl-3-oxo-2,3-dihydropyridazin-6-yloxy)-3-chromanol), a potassium channel opener, using sodium glycocholate (NaGC) as a surface stabilizer. Nanoparticle suspensions were evaluated to determine if targeted drug delivery to sebaceous glands and hair follicles could be achieved. In in vitro testing with rabbit ear tissue, delivery of UK-157,147 to the follicles was demonstrated with limited distribution to the surrounding dermis. Delivery to hair follicles was also demonstrated in vivo, based on stimulation of hair growth in tests of 100-nm nanoparticles with a C3H mouse model. The nanoparticles were well-tolerated, with no visible skin irritation. In vivo tests of smaller nanoparticles with a hamster ear model also indicated targeted delivery to sebaceous glands. The nanoparticles released drug rapidly in in vitro nonsink dissolution tests and were stable in suspension for 3 months. The present results show selective drug delivery to the follicle by follicular transport of nanoparticles and rapid release of a poorly water-soluble drug. Thus, nanoparticles represent a promising approach for targeted topical delivery of low-solubility compounds to hair follicles. PMID:21722722

  19. Cyclodextrin and Meglumine-Based Microemulsions as a Poorly Water-Soluble Drug Delivery System.

    PubMed

    Aloisio, Carolina; G de Oliveira, Anselmo; Longhi, Marcela

    2016-09-01

    Cyclodextrins (CDs) and meglumine (MEG) are pharmaceutical excipients widely used to improve solubility of poorly water-soluble drugs. The purpose of this work was to study the effect of CDs or MEG on the internal microstructure of soya oil-based O/W microemulsions (MEs) and on the modulation of the solubility and release rate of Class II model hydrophobic drugs, sulfamerazine and indomethacin. The pseudoternary phase diagrams revealed that higher proportions of oil phase, as well as the presence of β-cyclodextrin (ßCD), methyl-ßCD, and MEG, favored the incorporation of the drugs. The conductivity studies, particle size, and zeta potential analysis showed that the O/W ME structure remained unaffected and that the ME presented reduced droplet sizes after the incorporation of the ligands. The drug-component interactions were assessed by proton nuclear magnetic resonance studies. The highest incorporations of sulfamerazine (35.6 mg/mL) and indomethacin (73.1 mg/mL) were obtained with the ME with W = 5%, MEG and W = 1.8% ßCD in a phosphate buffer solution of pH 8, respectively. In addition, the ligands in ME significantly enhanced the released amount of the drugs, probably due to a solubilizing effect that facilitates the drug to penetrate the unstirred water layer adjacent to membranes. PMID:26886337

  20. Solubilization and Stabilization of Macular Carotenoids by Water Soluble Oligosaccharides and Polysaccharides

    PubMed Central

    Apanasenko, Irina E.; Selyutina, Olga Yu.; Polyakov, Nikolay E.; Suntsova, Lyubov P.; Meteleva, Elizaveta S.; Dushkin, Alexander V.; Vachali, Preejith; Bernstein, Paul S.

    2015-01-01

    Xanthophyll carotenoids zeaxanthin and lutein play a special role in the prevention and treatment of visual diseases. These carotenoids are not produced by the human body and must be consumed in the diet. On the other hand, extremely low water solubility of these carotenoids and their instability restrict their practical application as components of food or medicinal formulations. Preparation of supramolecular complexes of zeaxanthin and lutein with glycyrrhizic acid, its disodium salt and the natural polysaccharide arabinogalactan allows one to minimize the aforementioned disadvantages when carotenoids are used in food processing as well as for production of therapeutic formulations with enhanced solubility and stability. In the present study, the formation of supramolecular complexes was investigated by NMR relaxation, surface plasmon resonance (SPR) and optical absorption techniques. The complexes increase carotenoid solubility more than 1000-fold. The kinetics of carotenoid decay in reactions with ozone molecules, hydroperoxyl radicals and metal ions were measured in water and organic solutions, and significant increases in oxidation stability of lutein and zeaxanthin in arabinogalactan and glycyrrhizin complexes were detected. PMID:25527162

  1. Hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their influence on the water uptake of ammonium sulfate

    NASA Astrophysics Data System (ADS)

    Wu, Z. J.; Nowak, A.; Poulain, L.; Herrmann, H.; Wiedensohler, A.

    2011-03-01

    The hygroscopic behavior of atmospherically relevant water-soluble carboxylic salts and their effects on ammonium sulfate was investigated using a hygroscopicity tandem differential mobility analyzer (H-TDMA). No hygroscopic growth is observed for sodium oxalate, while ammonium oxalate shows slight growth (growth factor = 1.05 at 90%). The growth factors at 90% RH for sodium acetate, sodium malonate, sodium succinate, sodium tartrate, ammonium tartrate, sodium pyruvate, sodium maleate, and humic acid sodium salt are 1.79, 1.78, 1.69, 1.54, 1.29, 1.70, 1.78, and 1.19, respectively. The mixtures of organic salts with ammonium sulfate, which are prepared simulating the atmospheric aerosols, are determined. A clear shift in DRH of mixture to lower RH is observed with increasing organic mass fraction. Above RH = 80%, the humidograms of the different mixtures are quite close to that of pure ammonium sulfate. Köhler theory is used to predict the effective hygroscopicity parameter, κ, for mixtures at 90% RH. The results show that Köhler theory underestimated kappa for mixtures without considering the water solubility of ammonium oxalate. However, if the water solubility of ammonium oxalate is taken into account, the results show a much better agreement with those derived from H-TDMA measurements.

  2. Solubility of KF in water by molecular dynamics using the Kirkwood integration method

    NASA Astrophysics Data System (ADS)

    Ferrario, Mauro; Ciccotti, Giovanni; Spohr, Eckhard; Cartailler, Thierry; Turq, Pierre

    2002-09-01

    We have studied the solubility of potassium fluoride in aqueous solution at near ambient condition, using a simple modeling for the ion and water interactions and computing the values of the chemical potential by molecular dynamics within the framework of Kirkwood generalized thermodynamic integration approach for the evaluation of free energy differences. We report the details of the procedure we used, which is based--at variance with previous attempts--on the individual determination of the chemical potential for the ions in solution. We explore a wide range of salt concentrations up to more than 25 M and determine the solubility. The agreement with the experimental value is reasonable, taking account of the rather crude model used.

  3. Water Soluble Organic Compounds over the Eastern Mediterranean: Study of their occurrence and sources

    NASA Astrophysics Data System (ADS)

    Tziaras, T.; Spyros, A.; Mandalakis, M.; Apostolaki, M.; Stephanou, E. G.

    2010-05-01

    detects. The sampling period was 2007-2008. Measurements of collective parameters such as organic/elemental carbon (OC/EC), dissolved organic carbon (DOC), and aerosol surface active substances as methylene blue active substances (MBAS) were also performed. The concentration ranges for total suspended particles (TSP) was 12.3-61.1 microg m-3, for OC and EC 0.6-2.2 microg m-3 and 0.1-0.4 microg m-3 respectively, for DOC 0.7-1.8 microg m-3, and for MBAS 7.4-15.4 ng m-3. The average ratio OC/EC was 6.9 (+/- 3.5) and the proportion of DCO in relation to OC was 83 (+/-13) %, indicating a high degree of oxidation in the water-soluble organic matter. OC and DOC were statistically strongly correlated with the intensity of fire events in southern Europe. The analysis of the water soluble organic extract by GC/MS, NMR and revealed the presence of 130 individual organic compounds which made the 17% of DOC. The most significant categories were: I) Twenty (20) amino acids were determined as free (FAA) and combined (CAA) amino acids with an average concentration of 16 and 66 ng m-3 respectively. The average concentration of total amino acids (TAA) was 82 ng m-3. Glycine, glutamine, glutamic acid, aspartic acid and alanine made the 87% of the FAA fraction and glycine, alanine, glutamic acid, aspartic acid, valine and leucine the 87% of CAA. Statistically significant correlations were found between FAA and CAA, and MBAS and the intensity of fire events. II) Twenty six (26) n-alkanoic acids (C2-C14) were detected with an average concentration of 145 ng m-3. Acetic acid, tridecanoic and heneicosanoic acids demonstrated the highest correlation with fire events. III) Twenty two (22) saturated, unsaturated and branched dicarboxylic acids were analysed with an average concentration of 526 ng m-3. The highest statistical correlation with fire events was determined for the concentration of dicarboxylic acids with Cn larger than 6. IV) Thirty one (31) hydroxy-, oxo- and keto- carboxylic and

  4. Improved intestinal absorption of a poorly water-soluble oral drug using mannitol microparticles containing a nanosolid drug dispersion.

    PubMed

    Nishino, Yukiko; Kubota, Aya; Kanazawa, Takanori; Takashima, Yuuki; Ozeki, Tetsuya; Okada, Hiroaki

    2012-11-01

    A nozzle for a spray dryer that can prepare microparticles of water-soluble carriers containing various nanoparticles in a single step was previously developed in our laboratory. To enhance the solubility and intestinal absorption of poorly water-soluble drugs, we used probucol (PBL) as a poorly water-soluble drug, mannitol (MAN) as a water-soluble carrier for the microparticles, and EUDRAGIT (EUD) as a polymer vehicle for the solid dispersion. PBL-EUD-acetone-methanol and aqueous MAN solutions were simultaneously supplied through different liquid passages of the spray nozzle and dried together. PBL-EUD solid dispersion was nanoprecipitated in the MAN solution using an antisolvent mechanism and rapidly dried by surrounding it with MAN. PBL in the dispersion vehicle was amorphous and had higher physical stability according to powder X-ray diffraction and differential scanning calorimetry analysis. The bioavailability of PBL in PBL-EUD S-100-MAN microparticles after oral administration in rats was markedly higher (14- and 6.2-fold, respectively) than that of the original PBL powder and PBL-MAN microparticles. These results demonstrate that the composite microparticles containing a nanosized solid dispersion of a poorly water-soluble drug prepared using the spray nozzle developed by us should be useful to increase the solubility and bioavailability of drugs after oral administration. PMID:22864998

  5. Noncovalently-functionalized reduced graphene oxide sheets by water-soluble methyl green for supercapacitor application

    SciTech Connect

    Ren, Xiaoying; Hu, Zhongai Hu, Haixiong; Qiang, Ruibin; Li, Li; Li, Zhimin; Yang, Yuying; Zhang, Ziyu; Wu, Hongying

    2015-10-15

    Graphical abstract: Electroactive methyl green (MG) is selected to functionalize reduced graphene oxide (RGO) through non-covalent modification and the composite achieves high specific capacitance, good rate capability and excellent long life cycle. - Highlights: • MG–RGO composites were firstly prepared through non-covalent modification. • The mass ratio in composites is a key for achieving high specific capacitance. • MG–RGO 5:4 exhibits the highest specific capacitance of 341 F g{sup −1}. • MG–RGO 5:4 shows excellent rate capability and long life cycle. - Abstract: In the present work, water-soluble electroactive methyl green (MG) has been used to non-covalently functionalize reduced graphene oxide (RGO) for enhancing supercapacitive performance. The microstructure, composition and morphology of MG–RGO composites are systematically characterized by UV–vis absorption, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical performances are investigated by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS). The fast redox reactions from MG could generate additional pseudocapacitance, which endows RGO higher capacitances. As a result, the MG–RGO composite (with the 5:4 mass ratio of MG:RGO) achieve a maximum value of 341 F g{sup −1} at 1 A g{sup −1} within the potential range from −0.25 to 0.75 V and provide a 180% enhancement in specific capacitance in comparison with pure RGO. Furthermore, excellent rate capability (72% capacitance retention from 1 A g{sup −1} to 20 A g{sup −1}) and long life cycle (12% capacitance decay after 5000 cycles) are achieved for the MG–RGO composite electrode.

  6. Isolation and antiviral activity of water-soluble Cynomorium songaricum Rupr. polysaccharides.

    PubMed

    Tuvaanjav, Suvdmaa; Shuqin, Han; Komata, Masashi; Ma, Chunjie; Kanamoto, Taisei; Nakashima, Hideki; Yoshida, Takashi

    2016-01-01

    The plant, Cynomorium songaricum Rupr., is used as a traditional medicine in China and Mongolia. In the present study, two new water-soluble polysaccharides isolated from C. songaricum Rupr. were purified by successive Sephadex G-75 and G-50 column chromatographies and then characterized by high resolution NMR and IR spectroscopies. The molecular weights of two polysaccharides were determined by an aqueous GPC to be [Formula: see text] = 3.7 × 10(4) and 1.0 × 10(4), respectively. In addition, it was found that the polysaccharide with the larger molecular weight was an acidic polysaccharide. It was found that the iodine-starch reaction of both isolated polysaccharides was negative and the methylation analysis gave 2, 4, 6-tri-O-methyl alditol acetate as a main product. NMR and IR measurements and sugar analysis revealed that both polysaccharides had a (1 → 3)-α-d-glucopyranosidic main chain with a small number of branches. After sulfation, the sulfated C. songaricum Rupr. polysaccharides were found to have a potent inhibitory effect on HIV infection of MT-4 cells at a 50% effective concentration of 0.3-0.4 μg/ml, a concentration that has almost the same high activity as standard dextran and curdlan sulfates, EC50 = 0.35 and 0.14 μg/ml, respectively. The 50% cytotoxic concentration was low, CC50>1000 μg/ml. In addition, the interaction between the sulfated polysaccharides and poly-l-lysine as a model protein compound was investigated by a surface plasmon resonance to reveal the anti-HIV mechanism. PMID:26838028

  7. Phase equilibrium for surfactant Ls-54 in liquid CO2 with water and solubility estimation using the Peng-Robinson equation of state

    PubMed Central

    Tarafa, Pedro J.; Matthews, Michael A.

    2010-01-01

    It is known that the commercial surfactant Dehypon® Ls-54 is soluble in supercritical CO2 and that it enables formation of water-in-CO2 microemulsions. In this work we observed phase equilibrium for the Ls-54/CO2 and Ls-54/water/CO2 systems in the liquid CO2 region, from 278.15 - 298.15 K. In addition, the Peng-Robinson equation of state (PREOS) was used to model the phase behavior of Ls-54/CO2 binary system as well as to estimate water solubilities in CO2. Ls-54 in CO2 can have solubilities as high as 0.086 M at 278.15 K and 15.2 MPa. The stability of the microemulsion decreases with increasing concentration of water, and lower temperatures favor increased solubility of water into the one-phase microemulsion. The PREOS model showed satisfactory agreement with the experimental data for both Ls-54/CO2 and water/CO2 systems. PMID:21037962

  8. Dissolution and Solubility Enhancement of the Highly Lipophilic Drug Phenytoin via Interaction with Poly(N-isopropylacrylamide-co-vinylpyrrolidone) Excipients.

    PubMed

    Widanapathirana, Lakmini; Tale, Swapnil; Reineke, Theresa M

    2015-07-01

    Excipients of natural or synthetic origin play an important role in pharmaceutical performance to enhance the solubility, bioavailability, release, and stability of insoluble drugs. Herein, a series of seven excipient models was prepared by both homopolymerization and copolymerization of 1-vinyl-2-pyrrolidone (VP) and N-isopropylacrylamide (NIPAAm) by free radical polymerization yielding two homopolymers poly(VP) and poly(NIPAAm) and five copolymers of poly(NIPAAm-co-VP) at difference compositions. While the VP monomer provided aqueous solubility at a variety of conditions to the excipient, the incorporation of NIPAAm into the copolymer offered additional hydrogen bond donating sites to optimize the drug-polymer interactions in the system. Due to the presence of NIPAAm, the copolymers were sensitive to temperature as well. It was found that as the proportion of VP was increased (from 0 to 100%), the lower critical solution temperature (LCST) and the water solubility of the polymer models increased. To examine the role of specific drug-polymer interactions during dissolution on drug solubility and bioavailability, the polymers were formulated with the anticonvulsant drug phenytoin, which is a poorly water-soluble BCS class II drug where oral absorption is limited by the drug solubility. Amorphous solid dispersions (ASD) were prepared via spray drying of phenytoin with the polymer excipient models to contain 10% and 25% by weight drug loading. Physical characterization of the ASDs by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) revealed that the polymers held the drug in a high-energy amorphous phase in all the formulations prepared. All ASDs exhibited improved in vitro dissolution rates compared to drug only and physical mixtures of the polymers and the drug. Drug solubility was the highest with the ASDs containing poly(NIPAAm-co-VP) 60:40 and 50:50, which showed a solubility enhancement of near 14-fold increase compared to pure drug

  9. Chemical composition of water-soluble fraction in soils on glaciolacustrine deposits of the Russian Plain

    NASA Astrophysics Data System (ADS)

    Panova, E. G.; Oleinikova, G. A.; Matinyan, N. N.; Bakhmatova, K. A.

    2016-06-01

    The behavior of some chemical elements was studied in soils and their liquid phase. Two reference soil profiles on glaciolacustrine clays (soddy-eluvial-metamorphic soil) and sands (soddy podzol) were investigated on the Russian Plain. A colloidal fraction (particles <1 μm) was isolated with deionized hot water from a soil sample of 30 g at the soil: water ratio of 1: 10. The suspension was mixed for 6 h, settled for 24 h, and filtrated using a membrane filter (<1 μm). The soil sample and its water-soluble fraction (WSF) were analyzed by mass spectrometry with inductively coupled plasma. The chemical characteristics of the extracted liquid phase of the soil reflect its water-soluble component properties. The comparison of the data obtained with the results of the analysis for the whole soil allows assessment of a share of easily mobile and difficultly mobile forms of chemical compounds. This is the necessary basis for the development of a model describing the transport of metals in soil.

  10. Mutual solubility of water and structural/positional isomers of N-alkylpyridinium-based ionic liquids.

    PubMed

    Freire, Mara G; Neves, Catarina M S S; Shimizu, Karina; Bernardes, Carlos E S; Marrucho, Isabel M; Coutinho, João A P; Canongia Lopes, José N; Rebelo, Luís Paulo N

    2010-12-01

    Despite many previous important contributions to the characterization of the liquid-liquid phase behavior of ionic liquids (ILs) plus water systems, a gap still exists as far as the effect of isomers (of ILs) is concerned. Therefore, in this work, a comprehensive study of the liquid-liquid equilibria between water and isomeric pyridinium-based ionic liquids has been performed. Atmospheric pressure mutual solubilities between water and pyridinium-based ionic liquids combined with the common anion bis[(trifluoromethyl)sulfonyl]imide were experimentally determined between (288.15 and 318.15) K. The main goal of this work is to study the isomeric effects on the pyridinium-based cation, namely, the structural and positional isomerism, as well as the alkyl side chain length. To the best of our knowledge, the influence of both structural and positional isomerism on the liquid-liquid behavior in ionic-liquid-water-containing systems is an unexplored field and is here assessed for the first time. Moreover, from the experimental solubility data, several infinite dilution molar thermodynamic functions of solution, namely, the Gibbs energy, the enthalpy, and the entropy, were estimated and discussed. In addition, aiming at gathering a broader picture of the underlying thermodynamic solvation phenomenon, molecular dynamics simulations were also carried out for the same experimental systems. PMID:21077599

  11. The ultrafast reactions in the photochromic cycle of water-soluble fulgimide photoswitches.

    PubMed

    Slavov, C; Boumrifak, C; Hammer, C A; Trojanowski, P; Chen, X; Lees, W J; Wachtveitl, J; Braun, M

    2016-04-21

    Photochromic switches are essential for the control and manipulation of nanoscale reactions and processes. The expansion of their application to aqueous environments depends strongly on the development of optimized water-soluble photoswitches. Here we present a femtosecond time-resolved investigation of the photochromic reactions (transition between the open and the closed form) of a water-soluble indolylfulgimide. We observe a pronounced effect of the protic nature of water as a solvent on the ultrafast ring-opening reaction. Typically, the excited state of the closed form has a larger dipole moment than the ground state, which leads to stabilization of the excited state in polar solvents and hence a lifetime (3 ps) longer than in non-polar solvents (2 ps). However, in water, despite the increased solvent polarity and the increased excited state dipole moment, the opposite trend for the excited state lifetime is observed (1.8 ps). This effect is caused by the opening of a new excited state deactivation pathway involving proton transfer reactions. PMID:27020260

  12. Water-soluble germanium(0) nanocrystals: cell recognition and near-infrared photothermal conversion properties.

    PubMed

    Lambert, Timothy N; Andrews, Nicholas L; Gerung, Henry; Boyle, Timothy J; Oliver, Janet M; Wilson, Bridget S; Han, Sang M

    2007-04-01

    Surfactant-passivated germanium nanocrystals (Ge(0) NCs) 3-5 nm in diameter were synthesized and encapsulated with functionalized phospholipids to yield water-soluble Ge(0) NCs. Upon encapsulation, the NCs retained their cubic crystalline phase and displayed good resistance to oxidation, as determined by transmission electron microscopy and X-ray photoelectron spectroscopy. As a test of their cell compatibility, the ability of carboxyfluorescein (CF)-labeled dinitrophenyl (DNP)-functionalized Ge(0) NCs to crosslink dinitrophenol-specific immunoglobulin E antibodies on the surface of mast cells (RBL-2H3) was examined in vitro. Treatment with a multivalent DNP antigen (i.e., DNP-Ge(0) NCs or CF-DNP-Ge(0) NCs) caused crosslinking of FcepsilonRI receptors and cellular responses, which were evaluated with morphological and colorimetric assays and live-cell fluorescence microscopy. Incubation of RBL-2H3 cells with Ge(0) NCs for approximately 24 h gave less than a 2 % increase in cell death as compared to DNP-functionalized bovine serum albumin. When irradiated with near-infrared (NIR) radiation (lambda(exc)=770 nm, 1.1 W cm(-2)) from a continuous-wave Ti:sapphire laser, the bulk-solution temperature of a toluene solution containing 20 mg mL(-1) Ge(0) NCs increased by approximately 35 degrees C within 5 min. Phospholipid-encapsulated water-soluble Ge(0) NCs at concentrations of 1.0 mg mL(-1) also displayed stable photothermal behavior under repetitive and prolonged NIR laser exposures in water, to yield a temperature increase of approximately 20 degrees C within 5 min (lambda(exc)=770 nm, 0.9 W cm(-2)). The photothermal efficiency of water-soluble Ge(0) NCs compares favorably with a recent report for Au nanoshells. PMID:17299826

  13. Water-soluble noncovalent adducts of the heterometallic copper subgroup complexes and human serum albumin with remarkable luminescent properties.

    PubMed

    Chelushkin, P S; Krupenya, D V; Tseng, Yu-Jui; Kuo, Ting-Yi; Chou, Pi-Tai; Koshevoy, I O; Burov, S V; Tunik, S P

    2014-01-25

    Novel water-soluble noncovalent adducts of the heterometallic copper subgroup complexes and human serum albumin (HSA) display strong phosphorescence, internalize into HeLa cells and can be used in time-resolved fluorescent imaging. PMID:24296768

  14. Performance of porcine corneal opacity and permeability assay to predict eye irritation for water-soluble cosmetic ingredients.

    PubMed

    Van den Berghe, C; Guillet, M C; Compan, D

    2005-09-01

    The purpose of this paper is to report on the ability of an in-house porcine corneal opacity and permeability assay (PCOP) to predict eye irritation for cosmetic ingredients. Preliminary studies showed that the PCOP assay could accurately predict eye irritation class for liquid and water soluble materials. To broaden our experience a larger study on 50 cosmetic ingredients of this group was conducted. A prediction model (PM) was obtained based on only one endpoint-permeability measured after 30-min exposure O.D.30. This PM allows to distinguish nonirritating compounds (if O.D.30 < 0.35) from irritating (if O.D.30 > or = 0.35). Forty-nine of the 50 ingredients tested in the PCOP assay were accurately classified. The agreement was high (concordance 98%-kappa = 0.96). For 43 of the test substances an equation PM was obtained to predict the MAS. Despite satisfactory statistical coefficients this algorithm is not recommended due to wide 95% confidence intervals. These results confirm the usefulness of the PCOP for water-soluble cosmetic ingredients to discriminate nonirritants (MAS < or = 15) and irritants (MAS >15). For this type of ingredients the PCOP seems to be better than the BCOP to predict irritation class. Future work will be done to compare the BCOP and PCOP performances and to develop an appropriate protocol for water insoluble compounds. PMID:15922552

  15. The influence of sulfur on platinum solubility in water-saturated silicate melts

    NASA Astrophysics Data System (ADS)

    Gorbachev, Pavel; Bezmen, Nikolay

    2010-05-01

    P.N. Gorbachev1 (IGEM RAS), N.I. Bezmen2 (IEM RAS), 1Institute of Ore Deposits, Petrography, Mineralogy and Geochemistry (I.G.E.M.), Russian Academy of Sciences; p_gor@mail.ru 2 Institute of Experimental Mineralogy Russian Academy of Sciences; bezmen@iem.ac.ru In order to assess the influence of sulfur on Pt solubility in silicate melts we studied the Pt solubility in S- and H2O-bearing silicate melt. Experimental conditions were the same that the previous studies with S-free silicate melts [1]. Platinum solubility was determined in silicate melt of Di55An35Ab10 composition at oxygen fugacities varying between the HM and IW buffer at 1200°C and fluid pressure from 2129 to 3211 kbars. Hydrogen mole fraction varied from 0.002 to 0.248; lg fO2 from -6.53 at MMO buffer to -11.86 at IW buffer. Experiments were conducted in a vertically orientated internally heated gas high pressure vessel under conditions of known gas speciation and controlled fugacities. Glass samples were polished before analysis to remove possible contamination by the metal of the capsule and then boiled for 1 h in concentrated HCl. The oxygen fugacity was controlled by the double capsule buffer technique in oxidizing conditions (NM-NNO buffers) and by an Ar-H2-gas mixture at reducing conditions (XH2 > 0.05). Durations of all experiments were 3 days. Platinum concentrations were determined by instrumental neutron activation analysis (INNA). A significant similarity on Pt solubility in the S-bearing and S-free melts was observed. At reducing conditions (log fO2 < NNO buffer) a systematic decrease of the Pt solubility with decreasing fO2 was observed (from 32.870 to 23.849 ppm for S-bearing and 76.200 to 20.610 ppm for S-free melts respectively). At oxidizing conditions with a higher S concentration in the melt an increase in Pt concentrations was observed (from 24.660 to 54.960 and from 23.400 to 54.781 respectively). The presence of sulfur has a insignificant effect on Pt solubility. Although our

  16. Sources and their contribution to two water-soluble organic carbon fractions at a roadway site

    NASA Astrophysics Data System (ADS)

    Park, Seung-Shik; Schauer, James J.; Cho, Sung-Yong

    2013-10-01

    24-h PM2.5 samples were collected at a roadway site every 6th day for one year (September 2010 through August 2011) and analyzed for organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), hydrophilic and hydrophobic fractions of WSOC (WSOCHPI and WSOCHPO), and ionic species, to provide important seasonal quantitative information on the primary and secondary sources of two WSOC fractions. Five minute black carbon (BC) concentrations were also measured using a seven-channel wavelength aethalometer to investigate the relationship of biomass burning (BB)-derived BC data from a BC@880 nm tracer method and WSOC. There has been increased interest in the light adsorption of WSOC and water-insoluble OC but most of the tools that have been used to understand these relationships have limited to extracts of filter-based samples. The impact of BB emissions on WSOC fractions was examined using the relationship between ΔBC (=BC@370 nm - BC@880 nm) and WSOC (or K+), and between BB tracers (WSOC and K+) and BB-derived BC (BCBB) estimated. The moderate correlation (R2 = 0.41) of WSOC and ΔBC during the cold months of November through April may support the contribution of BB emissions to the observed WSOC. Predicted BCBB correlated well with K+, WSOCHPI, and WSOCHPO concentrations (R2 of 0.65, 0.43, and 0.61, respectively), suggesting BB emissions may have an influence on the WSOC fractions observed. Contributions of non-BB, BB, and secondary OC (SOC) to both WSOCHPI and WSOCHPO were estimated using a multiple linear regression analysis. The monthly average contribution of non-BB emissions ranged from 12.6% to 29.4% of the WSOCHPI and from 21.5% to 44.1% of the WSOCHPO, with high contributions occurring during the cold months and low contributions occurred during the warm months. BB emissions contributed more to WSOCHPI (2.7%-13.1%) than WSOCHPO (0.2%-1.1%), and the SOC contribution to both WSOC fractions was significant. SOC accounted for 57.2%-79.7% of

  17. Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

    NASA Astrophysics Data System (ADS)

    Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

    2008-12-01

    The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

  18. 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. PMID:18075217

  19. PLUTONIUM SOLUBILITY IN HIGH-LEVEL WASTE ALKALI BOROSILICATE GLASS

    SciTech Connect

    Marra, J.; Crawford, C.; Fox, K.; Bibler, N.

    2011-01-04

    The solubility of plutonium in a Sludge Batch 6 (SB6) reference glass and the effect of incorporation of Pu in the glass on specific glass properties were evaluated. A Pu loading of 1 wt % in glass was studied. Prior to actual plutonium glass testing, surrogate testing (using Hf as a surrogate for Pu) was conducted to evaluate the homogeneity of significant quantities of Hf (Pu) in the glass, determine the most appropriate methods to evaluate homogeneity for Pu glass testing, and to evaluate the impact of Hf loading in the glass on select glass properties. Surrogate testing was conducted using Hf to represent between 0 and 1 wt % Pu in glass on an equivalent molar basis. A Pu loading of 1 wt % in glass translated to {approx}18 kg Pu per Defense Waste Processing Facility (DWPF) canister, or about 10X the current allowed limit per the Waste Acceptance Product Specifications (2500 g/m{sup 3} of glass or about 1700 g/canister) and about 30X the current allowable concentration based on the fissile material concentration limit referenced in the Yucca Mountain Project License Application (897 g/m{sup 3}3 of glass or about 600 g Pu/canister). Based on historical process throughput data, this level was considered to represent a reasonable upper bound for Pu loading based on the ability to provide Pu containing feed to the DWPF. The task elements included evaluating the distribution of Pu in the glass (e.g. homogeneity), evaluating crystallization within the glass, evaluating select glass properties (with surrogates), and evaluating durability using the Product Consistency Test -- Method A (PCT-A). The behavior of Pu in the melter was evaluated using paper studies and corresponding analyses of DWPF melter pour samples.The results of the testing indicated that at 1 wt % Pu in the glass, the Pu was homogeneously distributed and did not result in any formation of plutonium-containing crystalline phases as long as the glass was prepared under 'well-mixed' conditions. The

  20. Sulfur speciation and stable isotope trends of water-soluble sulfates in mine tailings profiles.

    PubMed

    Dold, Bernhard; Spangenberg, Jorge E

    2005-08-01

    Sulfur speciation and the sources of water-soluble sulfate in three oxidizing sulfidic mine tailings impoundments were investigated by selective dissolution and stable isotopes. The studied tailings impoundments--Piuquenes, Cauquenes, and Salvador No. 1--formed from the exploitation of the Rio Blanco/La Andina, El Teniente, and El Salvador Chilean porphyry copper deposits, which are located in Alpine, Mediterranean, and hyperarid climates, respectively. The water-soluble sulfate may originate from dissolution of primary ore sulfates (e.g., gypsum, anhydrite, jarosite) or from oxidation of sulfide minerals exposed to aerobic conditions during mining activity. With increasing aridity and decreasing pyrite content of the tailings, the sulfur speciation in the unsaturated oxidation zones showed a trend from dominantly Fe(III) oxyhydroxide fixed sulfate (e.g., jarosite and schwertmannite) in Piuquenes toward increasing presence of water-soluble sulfate at Cauquenes and Salvador No. 1. In the saturated primary zones, sulfate is predominantly present in water-soluble form (mainly as anhydrite and/or gypsum). In the unsaturated zone at Piuquenes and Cauquenes, the delta34S(SO4)values ranged from +0.5 per thousand to +2.0 per thousand and from -0.4 per thousand to +1.4 per thousand Vienna Canyon Diablo Troilite (V-CDT), respectively, indicating a major sulfate source from pyrite oxidation (delta34S(pyrite) = -1.1 per thousand and -0.9 per thousand). In the saturated zone at Piuquenes and Cauquenes, the values ranged from -0.8 per thousand to +0.3 per thousand and from +2.2 per thousand to +3.9 per thousand, respectively. At Cauquenes the 34S enrichment in the saturated zone toward depth indicates the increasing contribution of isotopically heavy dissolved sulfate from primary anhydrite (approximately +10.9 per thousand). At El Salvador No. 1, the delta34S(SO4) average value is -0.9 per thousand, suggesting dissolution of supergene sulfate minerals (jarosite, alunite, gypsum