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Sample records for solutions exudate gels

  1. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel.

    Directory of Open Access Journals (Sweden)

    Lukas Böni

    Full Text Available Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v and with a soy emulsion (commercial soy milk to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making "soy slime", a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food

  2. Gelation of Soy Milk with Hagfish Exudate Creates a Flocculated and Fibrous Emulsion- and Particle Gel

    Science.gov (United States)

    Böni, Lukas; Rühs, Patrick A.; Windhab, Erich J.; Fischer, Peter; Kuster, Simon

    2016-01-01

    Hagfish slime is an ultra dilute, elastic and cohesive hydrogel that deploys within milliseconds in cold seawater from a glandularly secreted exudate. The slime is made of long keratin-like fibers and mucin-like glycoproteins that span a network which entraps water and acts as a defense mechanism against predators. Unlike other hydrogels, the slime only confines water physically and is very susceptible to mechanical stress, which makes it unsuitable for many processing operations and potential applications. Despite its huge potential, little work has been done to improve and functionalize the properties of this hydrogel. To address this shortcoming, hagfish exudate was mixed with a soy protein isolate suspension (4% w/v) and with a soy emulsion (commercial soy milk) to form a more stable structure and combine the functionalities of a suspension and emulsion with those of the hydrogel. Hagfish exudate interacted strongly with the soy systems, showing a markedly increased viscoelasticity and water retention. Hagfish mucin was found to induce a depletion and bridging mechanism, which caused the emulsion and suspension to flocculate, making “soy slime”, a cohesive and cold-set emulsion- and particle gel. The flocculation network increases viscoelasticity and substantially contributes to liquid retention by entrapping liquid in the additional confinements between aggregated particles and protein fibers. Because the mucin-induced flocculation resembles the salt- or acid-induced flocculation in tofu curd production, the soy slime was cooked for comparison. The cooked soy slime was similar to conventional cooked tofu, but possessed a long-range cohesiveness from the fibers. The fibrous, cold-set, and curd-like structure of the soy slime represents a novel way for a cold coagulation and fiber incorporation into a suspension or emulsion. This mechanism could be used to efficiently gel functionalized emulsions or produce novel tofu-like structured food products. PMID

  3. A comparative analysis of phloem exudate proteins from Cucumis melo, Cucumis sativus and Cucurbita maxima by polyacrylamide gel electrophoresis and isoelectric focusing.

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    Sabnis, D D; Hart, J W

    1976-01-01

    Proteins in sieve tube exudate from Cucumis melo L., Cucumis sativus L. and Cucurbita maxima Duch. were analysed by gel electrophoresis and isoelectric focusing. Estimated molecular weights and isoelectric points for the major and minor proteins from each plant species are presented. Electrophoresis revealed striking differences between the protein complements of exudatc from the two genera investigated. Similarly, although a few exudate proteins from the two species of Cucumis possessed identical molecular weights, several major proteins were peculiar to each species. Isoelectric focusing of proteins in exudate samples from the three plants confirmed the marked differences in their protein complements. Furthermore, focusing also revealed differences between cultivars of Cucumis sativus. Both Cucumis sativus and Cucurbita maxima possessed relatively large amounts of basic proteins; these were absent in exudate from Cucumis melo. The implications of these results are discussed in relation to present concepts regarding the interrelationships and possible functional roles of P-proteins.

  4. Electrophoresis of DNA in agarose gels, polyacrylamide gels and in free solution

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    Stellwagen, Nancy C.

    2009-01-01

    This review describes the electrophoresis of curved and normal DNA molecules in agarose gels, polyacrylamide gels and in free solution. These studies were undertaken to clarify why curved DNA molecules migrate anomalously slowly in polyacrylamide gels but not in agarose gels. Two milestone papers are cited, in which Ferguson plots were used to estimate the effective pore size of agarose and polyacrylamide gels. Subsequent studies on the effect of the electric field on agarose and polyacrylamide gel matrices, DNA interactions with the two gel matrices, and the effect of curvature on the free solution mobility of DNA are also described. The combined results suggest that the anomalously slow mobilities observed for curved DNA molecules in polyacrylamide gels are due primarily to preferential interactions of curved DNAs with the polyacrylamide gel matrix; the restrictive pore size of the matrix is of lesser importance. In free solution, DNA mobilities increase with increasing molecular mass until leveling off at a plateau value of (3.17 ± 0.01) × 10-4 cm2/Vs in 40 mM Tris-acetate-EDTA buffer at 20°C. Curved DNA molecules migrate anomalously slowly in free solution as well as in polyacrylamide gels, explaining why the Ferguson plots of curved and normal DNAs containing the same number of base pairs extrapolate to different mobilities at zero gel concentration. PMID:19517510

  5. Methods of plant root exudates analysis: a review

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    Peter Dundek

    2011-01-01

    Full Text Available The aim of this review is to summarise current knowledge on methods being used to determine individual compounds and properties of water-soluble plant root exudates. These compounds include amino acids, organic acids and simple sugars, as well as polysaccharides, proteins and organic substances. Qualitative composition of water-soluble root exudates and exudation rate are commonly measured with the aim of consequent synthetic preparation of plant root exudates to be supplied to soil to create artificial rhizosphere for different experimental purposes. Root exudates collection usually requires consequent filtration or centrifugation to remove solids, root detritus and microbial cell debris, and consequent concentration using an evaporator, lyophilizator or ultrafiltration. Methods used for analysis of total groups of compounds (total proteins and total carbohydrates and total organic carbon are simple. On the other hand, HPLC or GS/MS are commonly used to analyse individual low molecular weight organic molecules (sugars, organic acids and amino acids with separation using different columns. Other properties such as pH, conductivity or activity of different enzymes as well as gel electrophoresis of proteins are sometimes assessed. All of these methods are discussed in this work.

  6. A combinatory approach for analysis of protein sets in barley sieve-tube samples using EDTA-facilitated exudation and aphid stylectomy.

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    Gaupels, Frank; Knauer, Torsten; van Bel, Aart J E

    2008-01-01

    This study investigated advantages and drawbacks of two sieve-tube sap sampling methods for comparison of phloem proteins in powdery mildew-infested vs. non-infested Hordeum vulgare plants. In one approach, sieve tube sap was collected by stylectomy. Aphid stylets were cut and immediately covered with silicon oil to prevent any contamination or modification of exudates. In this way, a maximum of 1muL pure phloem sap could be obtained per hour. Interestingly, after pathogen infection exudation from microcauterized stylets was reduced to less than 40% of control plants, suggesting that powdery mildew induced sieve tube-occlusion mechanisms. In contrast to the laborious stylectomy, facilitated exudation using EDTA to prevent calcium-mediated callose formation is quick and easy with a large volume yield. After two-dimensional (2D) electrophoresis, a digital overlay of the protein sets extracted from EDTA solutions and stylet exudates showed that some major spots were the same with both sampling techniques. However, EDTA exudates also contained large amounts of contaminative proteins of unknown origin. A combinatory approach may be most favourable for studies in which the protein composition of phloem sap is compared between control and pathogen-infected plants. Facilitated exudation may be applied for subtractive identification of differentially expressed proteins by 2D/mass spectrometry, which requires large amounts of protein. A reference gel loaded with pure phloem sap from stylectomy may be useful for confirmation of phloem origin of candidate spots by digital overlay. The method provides a novel opportunity to study differential expression of phloem proteins in monocotyledonous plant species.

  7. Thermodynamic analysis of sol-gel transition of gelatin in terms of water activity in various solutions.

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    Miyawaki, Osato; Omote, Chiaki; Matsuhira, Keiko

    2015-12-01

    Sol-gel transition of gelatin was analyzed as a multisite stoichiometric reaction of a gelatin molecule with water and solute molecules. The equilibrium sol-gel transition temperature, Tt , was estimated from the average of gelation and melting temperature measured by differential scanning calorimetry. From Tt and the melting enthalpy, ΔHsol , the equilibrium sol-to-gel ratio was estimated by the van't Hoff equation. The reciprocal form of the Wyman-Tanford equation, which describes the sol-to-gel ratio as a function of water activity, was successfully applied to obtain a good linear relationship. From this analysis, the role of water activity on the sol-gel transition of gelatin was clearly explained and the contributions of hydration and solute binding to gelatin molecules were separately discussed in sol-gel transition. The general solution for the free energy for gel-stabilization in various solutions was obtained as a simple function of solute concentration. © 2015 Wiley Periodicals, Inc.

  8. Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

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    Dotto, Sidney Ricardo; Travassos, Rosana Maria Coelho; de Oliveira, Elias Pandonor Motcy; Machado, Manoel Eduardo de Lima; Martins, José Luiz

    2007-08-01

    The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

  9. Root exudation of phytosiderophores from soil-grown wheat

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    Oburger, Eva; Gruber, Barbara; Schindlegger, Yvonne; Schenkeveld, Walter D C; Hann, Stephan; Kraemer, Stephan M; Wenzel, Walter W; Puschenreiter, Markus

    2014-01-01

    For the first time, phytosiderophore (PS) release of wheat (Triticum aestivum cv Tamaro) grown on a calcareous soil was repeatedly and nondestructively sampled using rhizoboxes combined with a recently developed root exudate collecting tool. As in nutrient solution culture, we observed a distinct diurnal release rhythm; however, the measured PS efflux was c. 50 times lower than PS exudation from the same cultivar grown in zero iron (Fe)-hydroponic culture. Phytosiderophore rhizosphere soil solution concentrations and PS release of the Tamaro cultivar were soil-dependent, suggesting complex interactions of soil characteristics (salinity, trace metal availability) and the physiological status of the plant and the related regulation (amount and timing) of PS release. Our results demonstrate that carbon and energy investment into Fe acquisition under natural growth conditions is significantly smaller than previously derived from zero Fe-hydroponic studies. Based on experimental data, we calculated that during the investigated period (21–47 d after germination), PS release initially exceeded Fe plant uptake 10-fold, but significantly declined after c. 5 wk after germination. Phytosiderophore exudation observed under natural growth conditions is a prerequisite for a more accurate and realistic assessment of Fe mobilization processes in the rhizosphere using both experimental and modeling approaches. PMID:24890330

  10. Macromolecular composition of phloem exudate from white lupin (Lupinus albus L.

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    Mann Anthea J

    2011-02-01

    Full Text Available Abstract Background Members of the legume genus Lupinus exude phloem 'spontaneously' from incisions made to the vasculature. This feature was exploited to document macromolecules present in exudate of white lupin (Lupinus albus [L.] cv Kiev mutant, in particular to identify proteins and RNA molecules, including microRNA (miRNA. Results Proteomic analysis tentatively identified 86 proteins from 130 spots collected from 2D gels analysed by partial amino acid sequence determination using MS/MS. Analysis of a cDNA library constructed from exudate identified 609 unique transcripts. Both proteins and transcripts were classified into functional groups. The largest group of proteins comprised those involved in metabolism (24%, followed by protein modification/turnover (9%, redox regulation (8%, cell structural components (6%, stress and defence response (6% with fewer in other groups. More prominent proteins were cyclophilin, ubiquitin, a glycine-rich RNA-binding protein, a group of proteins that comprise a glutathione/ascorbate-based mechanism to scavenge oxygen radicals, enzymes of glycolysis and other metabolism including methionine and ethylene synthesis. Potential signalling macromolecules such as transcripts encoding proteins mediating calcium level and the Flowering locus T (FT protein were also identified. From around 330 small RNA clones (18-25 nt 12 were identified as probable miRNAs by homology with those from other species. miRNA composition of exudate varied with site of collection (e.g. upward versus downward translocation streams and nutrition (e.g. phosphorus level. Conclusions This is the first inventory of macromolecule composition of phloem exudate from a species in the Fabaceae, providing a basis to identify systemic signalling macromolecules with potential roles in regulating development, growth and stress response of legumes.

  11. Metabolite Profiling of Root Exudates of Common Bean under Phosphorus Deficiency

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    Keitaro Tawaraya

    2014-07-01

    Full Text Available Root exudates improve the nutrient acquisition of plants and affect rhizosphere microbial communities. The plant nutrient status affects the composition of root exudates. The purpose of this study was to examine common bean (Phaseolus vulgaris L. root exudates under phosphorus (P deficiency using a metabolite profiling technique. Common bean plants were grown in a culture solution at P concentrations of 0 (P0, 1 (P1 and 8 (P8 mg P L−1 for 1, 10 and 20 days after transplanting (DAT. Root exudates were collected, and their metabolites were determined by capillary electrophoresis time-of-flight mass spectrometry (CE-TOF MS. The shoot P concentration and dry weight of common bean plants grown at P0 were lower than those grown at P8. One hundred and fifty-nine, 203 and 212 metabolites were identified in the root exudates, and 16% (26/159, 13% (26/203 and 9% (20/212 of metabolites showed a P0/P8 ratio higher than 2.0 at 1, 10 and 20 DAT, respectively. The relative peak areas of several metabolites, including organic acids and amino acids, in root exudates were higher at P0 than at P8. These results suggest that more than 10% of primary and secondary metabolites are induced to exude from roots of common bean by P deficiency.

  12. Hagfish slime exudate stabilization and its effect on slime formation and functionality.

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    Böni, L J; Zurflüh, R; Widmer, M; Fischer, P; Windhab, E J; Rühs, P A; Kuster, S

    2017-07-15

    Hagfish produce vast amounts of slime when under attack. The slime is the most dilute hydrogel known to date, and is a highly interesting material for biomaterial research. It forms from a glandular secrete, called exudate, which deploys upon contact with seawater. To study slime formation ex vivo and to characterize its material properties, stabilization of the sensitive slime exudate is crucial. In this study, we compared the two main stabilization methods, dispersion in high osmolarity citrate/PIPES (CP) buffer and immersion in oil, and tested the influence of time, temperature and pH on the stability of the exudate and functionality of the slime. Using water retention measurements to assess slime functionality, we found that CP buffer and oil preserved the exudate within the first 5 hours without loss of functionality. For longer storage times, slime functionality decreased for both stabilization methods, for which the breakdown mechanisms differed. Stabilization in oil likely favored temperature-sensitive osmotic-driven swelling and rupture of the mucin vesicles, causing the exudate to gel and clump. Extended storage in CP buffer resulted in an inhibited unraveling of skeins. We suggest that a water soluble protein glue, which mediates skein unraveling in functional skeins, denatures and gradually becomes insoluble during storage in CP buffer. The breakdown was accentuated when the pH of the CP buffer was raised from pH 6.7 to pH 8.5, probably caused by increased denaturation of the protein glue or by inferior vesicle stabilization. However, when fresh exudate was mixed into seawater or phosphate buffer at pH 6-9, slime functionality was not affected, showing pH insensitivity of the slime formation around a neutral pH. These insights on hagfish exudate stabilization mechanisms will support hagfish slime research at a fundamental level, and contribute to resolve the complex mechanisms of skein unraveling and slime formation. © 2017. Published by The Company

  13. Root exudate as major player on soil-water retention dynamics

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    Albalasmeh, A. A.; Sweet, J. R.; Gebrenegus, T. B.; Ghezzehei, T. A.

    2012-12-01

    Plant roots and soil microbes release 5-60% of the entirety of photosynthetically fixed carbon in to the soil as exudates to adapt to their surrounding. There is indirect evidence suggesting that these exudates play a major role in altering the of the soil water retention properties. In this study, we used a uniformly sized (40 μm) glass beads and various concentrations (0, 2, 10, 20 and 29 g/L) of polygalacutronic acid (PGA) to mimic sandy soil and the organic exudates from plant roots, respectively. The samples were subjected to periods of drying and subsequent equilibration. At each stage, the water potential was measured using WP4C Dewpoint PotentiaMeter. The effect of root exudates on soil water retention can be attributed t at least two factors. The most widely speculated effect is through enhanced of soil aggregation. This effect is primarily due to capillary adhesion in fine pores within aggregates and is consistent was visual observation of pronounced aggregation in many rhizosphere soils. The second factor is related to osmotic effect of the exudate solution. Our observations show that the capillary effect is mostly to higher water potential regime (> -1 bar suction). Whereas the osmotic effect dominates in plant-soil relations.

  14. Rheology of Biopolymer Solutions and Gels

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    David R. Picout

    2003-01-01

    Full Text Available Rheological techniques and methods have been employed for many decades in the characterization of polymers. Originally developed and used on synthetic polymers, rheology has then found much interest in the field of natural (bio polymers. This review concentrates on introducing the fundamentals of rheology and on discussing the rheological aspects and properties of the two major classes of biopolymers: polysaccharides and proteins. An overview of both their solution properties (dilute to semi-dilute and gel properties is described.

  15. A Stable-Isotope Mass Spectrometry-Based Metabolic Footprinting Approach to Analyze Exudates from Phytoplankton

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    Mark R. Viant

    2013-10-01

    Full Text Available Phytoplankton exudates play an important role in pelagic ecology and biogeochemical cycles of elements. Exuded compounds fuel the microbial food web and often encompass bioactive secondary metabolites like sex pheromones, allelochemicals, antibiotics, or feeding attractants that mediate biological interactions. Despite this importance, little is known about the bioactive compounds present in phytoplankton exudates. We report a stable-isotope metabolic footprinting method to characterise exudates from aquatic autotrophs. Exudates from 13C-enriched alga were concentrated by solid phase extraction and analysed by high-resolution Fourier transform ion cyclotron resonance mass spectrometry. We used the harmful algal bloom forming dinoflagellate Alexandrium tamarense to prove the method. An algorithm was developed to automatically pinpoint just those metabolites with highly 13C-enriched isotope signatures, allowing us to discover algal exudates from the complex seawater background. The stable-isotope pattern (SIP of the detected metabolites then allowed for more accurate assignment to an empirical formula, a critical first step in their identification. This automated workflow provides an effective way to explore the chemical nature of the solutes exuded from phytoplankton cells and will facilitate the discovery of novel dissolved bioactive compounds.

  16. Changes of organic acid exudation and rhizosphere pH in rice plants under chromium stress

    International Nuclear Information System (INIS)

    Zeng Fanrong; Chen Song; Miao Ying; Wu Feibo; Zhang Guoping

    2008-01-01

    The effect of chromium (Cr) stress on the changes of rhizosphere pH, organic acid exudation, and Cr accumulation in plants was studied using two rice genotypes differing in grain Cr accumulation. The results showed that rhizosphere pH increased with increasing level of Cr in the culture solution and with an extended time of Cr exposure. Among the six organic acids examined in this experiment, oxalic and malic acid contents were relatively higher, and had a significant positive correlation with the rhizosphere pH, indicating that they play an important role in changing rhizosphere pH. The Cr content in roots was significantly higher than that in stems and leaves. Cr accumulation in plants was significantly and positively correlated with rhizosphere pH, and the exudation of oxalic, malic and citric acids, suggesting that an increase in rhizosphere pH, and exudation of oxalic, malic and citric acid enhances Cr accumulation in rice plants. - Rhizosphere pH and organic acid exudation of rice roots are markedly affected by chromium level in culture solution

  17. Marsh plant response to metals: Exudation of aliphatic low molecular weight organic acids (ALMWOAs)

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    Rocha, A. Cristina S.; Almeida, C. Marisa R.; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

    2016-03-01

    Metal exposure is known to induce the production and secretion of substances, such as aliphatic low molecular weight organic acids (ALMWOAs), into the rhizosphere by plant roots. Knowledge on this matter is extensive for soil plants but still considerably scarce regarding marsh plants roots adapted to high salinity media. Phragmites australis and Halimione portulacoides, two marsh plants commonly distributed in European estuarine salt marshes, were used to assess the response of roots of both species, in terms of ALMWOAs exudation, to Cu, Ni and Cd exposure (isolated and in mixture since in natural environment, they are exposed to mixture of metals). As previous studies were carried out in unrealistic and synthetic media, here a more natural medium was selected. Therefore, in vitro experiments were carried out, with specimens of both marsh plants, and in freshwater contaminated with two different Cu, Ni and Cd concentrations (individual metal and in mixture). Both marsh plants were capable of liberating ALMWOAs into the surrounding medium. Oxalic, citric and maleic acids were found in P. australis root exudate solutions and oxalic and maleic acids in H. portulacoides root exudate solutions. ALMWOA liberation by both plants was plant species and metal-dependent. For instance, Cu affected the exudation of oxalic acid by H. portulacoides and of oxalic and citric acids by P. australis roots. In contrast, Ni and Cd did not stimulate any specific response. Regarding the combination of all metals, H. portulacoides showed a similar response to that observed for Cu individually. However, in the P. australis case, at high metal concentration mixture, a synergetic effect led to the increase of oxalic acid levels in root exudate solution and to a decrease of citric acid liberation. A correlation between ALMWOAs exudation and metal accumulation could not be established. P. australis and H. portulacoides are considered suitable metal phytoremediators of estuarine impacted areas

  18. Carboxy methylation of cashew nut tree exudate gum

    International Nuclear Information System (INIS)

    Silva, Durcilene A. da; Paula, Regina C.M.

    2001-01-01

    Anacardium occidentale exudate polysaccharide was carboxymethylated with monochloroacetic acid. The samples were characterized by NMR, solution viscometry, GPC and thermal analysis. Carboxymethylated cashew gum (CMGC) with a degree of substitution between 0,1-0,16 was obtained. Solution viscometry and GPC analysis showed that polymer molar mass degradation occurred. Sample with higher DS shows higher peak molar mass, intrinsic viscosity and thermal stability. NMR spectrum indicated that the carboxy methylation reaction occurs preferentially in C-6 of galactose residue. (author)

  19. The inflow of Cs-137 in soil with root litter and root exudates of Scots pine

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    Shcheglov, Alexey; Tsvetnova, Olga; Popova, Evgenia

    2017-04-01

    In the model experiment on evaluation of Cs-137 inflow in the soil with litter of roots and woody plants root exudates on the example of soil and water cultures of Scots pine (Pinus sylvestris L.) was shown, that through 45 days after the deposit Cs-137 solution on pine needles (specific activity of solution was 3.718*106 Bk) of the radionuclide in all components of model systems has increased significantly: needles, small branches and trunk by Cs-137 surface contamination during the experiment; roots as a result of the internal distribution of the radionuclide in the plant; soil and soil solution due to the of receipt Cs-137 in the composition of root exudates and root litter. Over 99% of the total reserve of Cs-137 accumulated in the components of the soil and water systems, accounted for bodies subjected to external pollution (needles and small branches) and soil solution, haven't been subjected to surface contamination. At the same contamination of soil and soil solution by Cs-137 in the model experiment more than a> 99.9% was due to root exudates

  20. Colloidal probe dynamics in gelatin solution during the sol-gel transition.

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    Hong, Wei; Xu, Guozhi; Ou, Xiaogang; Sun, Weixiang; Wang, Tao; Tong, Zhen

    2018-05-16

    The dynamics of the colloidal probes in a gelatin solution during the time-dependent sol-gel transition was investigated by multi-particle tracking. The relationship between the relaxation of the medium at the critical gel point and the mean square displacement of the probes was elucidated. Based on this understanding, the critical gel point of gelatin and the corresponding critical exponent n were unambiguously determined by the loss angle criterion and the time-cure superposition. The shift factors of the latter are further used to estimate the time/length-scale evolution of the gelatin during the sol-gel transition. The growth of the medium length scale crossed with the two measuring length scales successively at the pre-gel regime. Coinciding with the length-scale crossovers, the probability density function (PDF) of the probe displacements displayed two transient peaks of non-Gaussianity. In the post-gel regime, the third peak of Gaussianity suggested inhomogeneity in the gel network. The non-Gaussianity results from the bifurcation of diffusivity. The present work showed that the non-Gaussian dynamics of the probes are not the direct equivalence of that of the medium, but an effect of length-scale coupling.

  1. Effect of timolol 0.5% gel and solution on pulmonary function in older glaucoma patients.

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    Stewart, W C; Day, D G; Holmes, K T; Stewart, J A

    2001-06-01

    To evaluate the effect of timolol maleate solution or gel forming solution versus placebo on pulmonary function in patients with primary open-angle glaucoma or ocular hypertension without reactive airway disease. After a screening visit, each patient was randomized by a Latin square technique to receive placebo twice daily, 0.5% timolol solution twice daily, or 0.5% timolol gel once a day (placebo given as second dose) to each eye for 2 weeks. Subjects then were crossed over to the two other treatments for 2-week treatment intervals. At each visit, patients were received a dose 15 minutes before pulmonary function testing. This study began with 25 patients, and 20 finished the trial. There was no difference between treatment groups for the forced expiratory volume at one second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio (P > 0.1). The mean FEV1 for timolol solution, timolol gel, and placebo was 2.42 L, 2.45 L, and 2.50 L, respectively. The mean FVC for timolol solution, timolol gel, and placebo was 3.33 L, 3.38 L, and 3.44 L, respectively. No difference in intraocular pressure was observed between the timolol solution (17.1 +/- 3.3 mm Hg) and timolol gel (17.1 +/- 3.6 mm Hg) between the treatment periods (P > 0.1). No difference in side effects was observed between treatment groups (P > 0.05). In older patients with primary open-angle glaucoma or ocular hypertension without reactive airway disease, nonselective beta-blockers should not worsen pulmonary function.

  2. Solution-mediated growth of NBA-ZSM-5 crystals retarded by gel entrapment

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    Aguilar-Mamani, Wilson; Akhtar, Farid; Hedlund, Jonas; Mouzon, Johanne

    2018-04-01

    The synthesis of flat tablet-shaped ZSM-5 crystals from a gel using metakaolin as aluminosilicate source and n-butyl amine as structure directing agent was investigated. The evolution inside the solid phase was characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetry and mass spectrometry. A kinetic study indicated that the nucleation of the majority crystals occurred concurrently with the formation of the gel upon heating the starting liquid suspension. Microstructural evidences undeniably showed that the gel precipitated on ZSM-5 crystals and mineral impurities originating from kaolin. As a result, crystal growth was retarded by gel entrapment, as indicated by the configuration and morphology of the embedded crystals. The results presented herein are harmonized with a solution-mediated nucleation and growth mechanism. Our observations differ from the autocatalytic model that suggests that the nuclei rest inside the gel until released when the gel is consumed. Our results show instead that it is crystals that formed in an early stage before entrapment inside the gel that rest inside the gel until exposed at the gel surface. These results illustrate the limitation of the classical method used in the field to determine nucleation profiles when the crystals become trapped inside the gel.

  3. PENGARUH KONSUMSI GEL DAN LARUTAN RUMPUT LAUT (Eucheuma cottonii TERHADAP HIPERKOLESTEROLEMIA DARAH TIKUS WISTAR [The Consumption Effect of Gel and Solution Types of Eucheuma cottonii Seaweeds on Hypercholesterolemic of Blood Wistar Rat

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    Hardoko

    2008-12-01

    Full Text Available The consumption effect of gel and solution of Eucheuma cottonii seaweed on blood lipid level were studied on hypercholesterolemic male wistar rat. The rat were made hypercholesterolemic by a ration that contained high lipid and cholesterol, and then they were given standard ration orally and 10, 15, and 20% (w/w feed of gel and solution seaweed parenterally. The results show that the standard ration could not reduce hypercholesterolemic to normal level while gel and solution of the seaweed could. The gel type of the seaweed has higher capacity decrease of cholesterol and triglyceride blood level. The consumption of seaweed gel 20% and 15% could reduce cholesterol to normal level in 9 and 15 days, respectively, while the solution type 20% needed 18 days. The seaweed gel 10%, solution 15% and 10% could reduce blood cholesterol level, but they could not reach to normal level in 18 days.

  4. Thermodynamic behavior of erythritol in aqueous solutions and in gelatine gels and its quantification

    International Nuclear Information System (INIS)

    Tyapkova, Oxana; Bader-Mittermaier, Stephanie; Schweiggert-Weisz, Ute

    2013-01-01

    Highlights: • Differential scanning calorimetry as a method to determine erythritol crystallization. • Determination of crystallization using solution enthalpy. • Erythritol crystallization influenced by area of air–water-interfaces. • DSC method is applicable for both aqueous solutions and gels. • Adaption of DSC method to other, more complex food matrices is possible. - Abstract: As crystallization of erythritol can cause a sandy mouth-feel in sugar-free products, strategies to avoid crystallization or adaption of food formulation should be elucidated. However, until now erythritol crystallization was only quantified in aqueous solutions, but not in model food systems. Differential scanning calorimetry (DSC) is a simple method for the quantification of phase transition in various systems. However, no methods for the quantification of crystallization from aqueous systems based on DSC have been published until now. In the present study DSC was found to be suitable for the quantification of crystallization using supersaturated aqueous solutions of erythritol and erythritol containing gelatine gels for the first time. The developed method was validated by comparing the crystallization values determined by gravimetric measurement of erythritol crystals and the values obtained by DSC. No significant differences (p < 0.05) have been obtained between the results of the two methods if an appropriate design of measurements was applied. Additionally, the method was adapted to gelatine gels to elucidate the transferability to model food systems. Hence, the method is suitable for quantification of the amount of erythritol crystals present in aqueous solutions and gels, respectively

  5. Physicochemical and functional parameters of Cochlospermum vitifolium (bototo gum exudate

    Directory of Open Access Journals (Sweden)

    Maritza Coromoto Martínez

    2016-12-01

    Full Text Available The physicochemical parameters of Cochlospermum vitifolium they were evaluated and were linked to certain functional properties of industrial interest. The physicochemical parameters were determined by the classic methodology used for carbohydrates and the functional properties, as reported in the literature. The results obtained showed that the gum object of this study is low soluble in water, which corresponds with relatively high values of swelling indexes and water absorption capacity. Also, the intrinsic viscosity of the C. vitifolium exudate was related to a high molar mass, in the order of 106. Its emulsifying capacity is high, which is attributed to hydrophobic groups present in its structure. The gum gels at a minimum concentration, similar to that of the gum karaya (4.5%, but the gel that forms agglomerates, it is not uniform. The C. vitifolium gum exhibits important physicochemical and functional parameters which could serve as a criterion for testing its use in various industries.

  6. MICROBIAL IMPACTS ON THE MIGRATION OF ACTINIDES -EFFECTS OF EXUDATES ON ADSORPTION-

    International Nuclear Information System (INIS)

    OHNUKI, T.; OZAKI, T.; YOSHIDA, T.; NANKAWA, T.; KOZAI, N.; SAKAMOTO, F.; SUZUKI, Y.; FRANCIS, A.J.

    2006-01-01

    The interaction of actinides with microorganisms has been extensively studied to elucidate migration behavior of actinides in the environments. However, the mechanisms of interaction of microorganisms and actinides are poorly understood. They have been conducting basic science on microbial accumulation of actinides in order to elucidate the environmental behavior of actinides under relevant conditions. The effect of exudates from bacteria cells on the sorption of Eu(III) and Cm(III) by Chlorella vulgaris was studied by a batch method. The pH dependence of log K d of Eu(III) and Cm(III) for cellulose, major component of C. vulgaris cell, differed from that for C. vulgaris. On the contrary, log K d of Eu(III) and Cm(III) for cellulose in the solution containing exudates from C. vulgaris cells in a 0.5% NaCl solution showed a similar pH dependence to that by C. vulgaris. These results strongly suggested that exudates affect on the sorption of Eu(III) and Cm(III) on C. vulgaris. Effect of desferrioxamine B (DFO), one of exudates to chelate the insoluble Fe(III), on the sorption of Pu(IV), Th(IV) and Eu(III) by Pseudomonas fluorescens was studied. In the presence of DFO the sorption of Pu(IV), Th(IV) and Eu(III) on the cells increased with a decrease in pH from 7 to 4. In contrast, without DFO most of Pu(IV), Th(IV) and Eu(III) were precipitated from solution. Adsorption of DFO on the cells was negligible in the solution with and without metals. Adsorption of Pu(IV), Th(IV) and Eu(III) on P. fluorescens cells decreased in the order Eu(III) > Th(IV) > Pu(IV), which corresponds to increasing stability constant of the DFO complexes. These results indicate that Th(IV), Pu(IV) and Eu(III) dissociate when in contact with cells, after which the metals are adsorbed

  7. Microbial impacts on the migration of actinides. Effects of exudates on adsorption

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko; Ozaki, Takuo; Nakawa, Takuya; Kozai, Naofumi; Sakamoto, Fuminori; Suzuki, Yosinori; Yoshida, Takahiro; Francis, Arokiasamy J.

    2007-01-01

    The interaction of actinides with microorganisms has been extensively studied to elucidate migration behavior of actinides in the environments. However, the mechanisms of interaction of microorganisms and actinides are poorly understood. We have been conducting basic science on microbial accumulation of actinides in order to elucidate the environmental behavior of actinides under relevant conditions. The effect of exudates from bacteria cells on the sorption of Eu(III) and Cm(III) by Chlorella vulgaris was studied by a batch method. The pH dependence of log K d of Eu(III) and Cm(III) for cellulose, major component of C. vulgaris cell, differed from that for C. vulgaris. On the contrary, log K d of Eu(III) and Cm(III) for cellulose in the solution containing exudates from C. vulgaris cells in a 0.5% NaCl solution showed a similar pH dependence to that by C. vulgaris. These results strongly suggested that exudates affect on the sorption of Eu(III) and Cm(III) on C. vulgaris. Effect of desferrioxamine B (DFO), one of exudates to chelate with insoluble Fe(III), on the sorption of Pu(IV), Th(IV) and Eu(III) by Pseudomonas fluorescens was studied. In the presence of DFO the sorption of Pu(IV), Th(IV) and Eu(III) on the cells increased with a decrease in pH from 7 to 4. In contrast, without DFO most of Pu(IV), Th(IV) and Eu(III) were precipitated from solution. Adsorption of DFO on the cells was negligible in the solution with and without metals. Adsorption of Pu(IV), Th(IV) and Eu(III) on P. fluorescens cells decreased in the order Eu(III) > Th(IV) > Pu(IV), which corresponds to increasing stability constant of the DFO complexes. These results indicate that Th(IV), Pu(IV) and Eu(III) dissociate when in contact with cells, after which the metals are adsorbed. (author)

  8. Studies on photosynthate distribution and root exudates of cinesische by 14C tracer technique

    International Nuclear Information System (INIS)

    Chen Junwei; Ni Zhuru; Liu Zhihong; Fu Zhijian

    1994-01-01

    Cinesische (Cunninghamia sinesis R. Br.) plants grown in nutrient solution were exposed to 14 CO 2 for 24 hours to study the photosynthate distribution and root exudates. One day after feeding 14 CO 2 , the majority of 14 C assimilate was remained in leaves, only 27.38% of 14 C assimilate was translocated into new shoots, main branches, lateral branches and roots. 3 days after feeding 14 CO 2 , the distribution rate of 14 C photosynthate in leaves was still the highest, but the percentage decreased and it correspondingly increased in other plant parts. 22 days after feeding 14 CO 2 , the distribution rate in new shoots became the highest, roots ranked the second, main branches were the third, leaves and lateral branches were the lowest. The photosynthate in the root could rapidly convert into root exudates. The amount of root exudates reached a peak after 4 days of feeding 14 CO 2 , afterward the amount of 14 C root exudates decreased rapidly. The amount of sugar was the highest among all kinds of root exudates, the amount of organic acid was the second, the content of amino acid was much lower than that of the other two root exudates

  9. SANS contrast in iota-carrageenan gels and solutions in D2O

    DEFF Research Database (Denmark)

    Mischenko, N.; Denef, B.; Mortensen, K.

    1997-01-01

    SANS of Na+-iota-carrageenan in D2O/saline solutions was measured as a function of concentration, temperature and type of counterions (K+ or Na+). High and low scattering-contrasted gels and solutions were detected. High contrast is caused by aggregation of low-hydrated chains at high concentration...

  10. Influence of Root Exudates and Soil on Attachment of Pasteuria penetrans to Meloidogyne arenaria.

    Science.gov (United States)

    Liu, Chang; Timper, Patricia; Ji, Pingsheng; Mekete, Tesfamariam; Joseph, Soumi

    2017-09-01

    The bacterium Pasteuria penetrans is a parasite of root-knot nematodes ( Meloidogyne spp.). Endospores of P. penetrans attach to the cuticle of second-stage juveniles (J2) and subsequently sterilize infected females. When encumbered by large numbers of spores, juveniles are less mobile and their ability to infect roots is reduced. This study looked at different factors that influence spore attachment of P. penetrans to the root-knot nematode Meloidogyne arenaria . Pretreatment of J2 with root exudates of eggplant ( Solanum melongena cv. Black beauty) reduced spore attachment compared with pretreatment with phosphate-buffered saline (PBS), suggesting that the nematode surface coat was altered or the spore recognition domains on the nematode surface were blocked. Spore attachment was equally reduced following exposure to root exudates from both host and nonhost plants for M. arenaria , indicating a common signal that affects spore attachment. Although phytohormones have been shown to influence the lipophilicity of the nematode surface coat, auxins and kinetins did not affect spore attachment compared with PBS. Root exudates reduced spore attachment more in sterilized soil than in natural soil. Sterilization may have eliminated microbes that consume root exudates, or altered the chemical components of the soil solution or root exudates. Root exudates caused a greater decrease in spore attachment in loamy sand than in a sandy loam soil. The sandy loam had higher clay content than the loamy sand, which may have resulted in more adsorption of compounds in the root exudates that affect spore attachment. The components of the root exudates could have also been modified by soil type. The results of this study demonstrate that root exudates can decrease the attachment of P. penetrans endospores to root-knot nematodes, indicating that when these nematodes enter the root zone their susceptibility to spore attachment may decrease.

  11. Optical signal response pf the alanine gel solution for photons and electrons clinical beams

    International Nuclear Information System (INIS)

    Silva, Cleber Feijo; Campos, Leticia Lucente

    2009-01-01

    Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The measure technique is based on the transformation of ferrous ions (Fe 2+ ) in ferric ions (Fe 3+ ) after irradiation. The DL-Alanine (C 3 H 7 NO 2 ) is an aminoacid tissue equivalent that improves the production of ferric ions in the solution. This work aims to study the comparison of optical signal response of the alanine gel solution for photons and electrons clinical beams. It was observed that the calibration factor can be considered independent of quality of the radiation for photons and electrons clinical beams. Therefore, it can be used the same calibration factor for evaluating the absorbed dose in photons and electrons fields in the energy of 6 MeV. Alanine Gel Dosimeter presents good performance and can be useful as alternative dosimeter in the radiotherapy area using MRI technique for 3D dose distribution evaluation. (author)

  12. Subretinal lipid exudation associated with untreated choroidal melanoma

    Directory of Open Access Journals (Sweden)

    C K Minija

    2011-01-01

    Full Text Available Subretinal lipid exudation in an untreated choroidal melanoma is very rare. It is seen following plaque radiotherapy in choroidal melanoma. There is only one case report of untreated choroidal melanoma with massive lipid exudation in a patient with metastatic hypernephroma. We report here a rare case of untreated choroidal melanoma with lipid exudation. Subretinal exudation that is rarely seen following plaque brachytherapy was noted at the borders of this untreated tumor. Lipid exudation partially resolved following brachytherapy.

  13. Solution Processable Electrochemiluminescent Ion Gels for Flexible, Low Voltage, Emissive Displays on Plastic

    Science.gov (United States)

    Moon, Hong Chul; Lodge, Timothy P.; Frisbie, C. Daniel

    2014-03-01

    We have expanded the functionality of ion gels and successfully demonstrated low voltage, flexible electrochemiluminescent (ECL) devices using patterned ECL gels. An ECL device composed of only an emissive gel and two electrodes was fabricated on an ITO-coated substrate by solution casting the ECL gel and brush-painting the top silver electrode. The device turned on at an AC voltage as low as 2.6 V (-1.3 V ~ +1.3 V) and showed a relatively rapid response (sub-ms). Also, we varied the mechanical properties of the ECL gel simply by substituting polystyrene-block-poly(methyl methacrylate)-block-polystyrene (SMS) with commercially available poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP)), enabling the fabrication of flexible ECL devices on any target substrate by the ``cut-and-stick'' strategy. This simple, rubbery ECL gel should be attractive for flexible electronics applications such as displays on packaging.

  14. Patterning titania with the conventional and modified micromolding in capillaries technique from sol–gel and dispersion solutions

    Directory of Open Access Journals (Sweden)

    Sajid Ullah Khan and Johan E ten Elshof

    2012-01-01

    Full Text Available We report TiO2 patterns obtained by a soft-lithographic technique called 'micromolding in capillaries' using sol–gel and dispersion solutions. A comparison between patterning with a sol–gel and dispersion solutions has been performed. The patterns obtained from sol–gel solutions showed good adhesion to the substrate and uniform shapes, but large shrinkage, whereas those obtained from dispersion solution had high solid content, but exhibited poor adhesion and non-uniform shapes. A fabrication method of a layer-by-layer structured pattern is also demonstrated. This type of pattern may find application in sensors, waveguides and other photonics elements. The occurrence of an undesirable residue layer, which hinders the fabrication of isolated patterns, is highlighted and a method of prevention is suggested.

  15. Adsorption and Desorption of Na+ and NO3− Ions on Thermosensitive NIPAM-co-DMAAPS Gel in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Eva Oktavia Ningrum

    2017-11-01

    Full Text Available Adsorbent gel with the ability to absorb and to desorb Na+ and NO3− ions simultaneously with temperature swing was synthesized by free radical copolymerization reaction of N-isopropylacrylamide (NIPAM and N,N-dimethyl-(acrylamidopropylammonium propane sulfonate (DMAAPS. In this study, NIPAM acts as a thermosensitive agent and DMAAPS as an adsorbent agent. The purpose of this research is to investigate the effect of temperature and solution concentration on the swelling, adsorption, and desorption behaviors of NIPAM-co-DMAAPS gel. The relationship between adsorption and desorption behaviors of the gel was also elucidated. NaNO3 solution was selected as the target solution in swelling, adsorption, and desorption test. It was observed that the swelling degree of the gel increased as temperature and solution concentration raised. The adsorption amount of ions decreased with the increase of temperature. In contrast, the amount of ions desorbed from the gel increased linearly with temperature.

  16. Determination of hexamethylene tetramine in the process solution of sol-gel method for nuclear fuel fabrication

    International Nuclear Information System (INIS)

    Ganatra, V.R.; Sawant, R.M.; Chaudhuri, N.K.; Vaidya, V.N.

    1998-01-01

    Hexamethylene tetramine (HMTA) was determined in the presence of large quantities of urea, formaldehyde and ammonium hydroxide by potentiometric titration with perchloric acid solution using an autotitrator coupled to a personal computer. This analysis is required for the process control of the sol-gel method in the production of ceramic metal oxide (e.g., oxides and mixed oxides of Th, U and Pu) microspheres using the internal gelation route. Feed solution used for preparation of microspheres contains large quantities of urea. The washings of gel microspheres produced after the internal gelation process contain urea, formaldehyde, urea-formaldehyde complex and ammonium hydroxide. The presence of these constituents in the feed solution and washings seriously interfere in the commonly used methods for the determination of HMTA. Using this method the relative standard deviation was found to be 0.27% in eleven determinations of a typical feed solution (3.0M HMTA) when the aliquots contained 75 to 125 mg of HMTA. Time required for each titration was 5-7 minutes. Feed and effluent solutions of sol-gel process were analysed. (author)

  17. Thermal decomposition and spectroscopic investigation of a new aqueous glycolato(-peroxo) Ti(IV) solution-gel precursor

    International Nuclear Information System (INIS)

    De Dobbelaere, Christopher; Mullens, Jules; Hardy, An; Van Bael, Marlies K.

    2011-01-01

    Highlights: → A totally water based glycolato-Ti(IV) precursor is presented and characterized. → The precursors' thermal decomposition profile depends on the ligand to metal ratio. → Titanium is coordinated in an unidentate fashion by the glycolate anion. → Smooth and uniform TiO 2 films can be prepared from the precursor solution. - Abstract: A new aqueous solution-gel precursor based on water soluble glycolato(-peroxo)-Ti(IV) complexes is developed for the preparation of TiO 2 films. With regard to the decomposition of complexes towards oxide formation, it is important to gain insight in the chemical transformations inside the precursor during thermal treatment. Therefore, the thermo-oxidative decomposition pathway of a gel obtained by slow evaporation of the precursor solution is described based on hyphenated thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). Pure glycolic acid is used as a reference system for this study. By varying the molar glycolic acid to Ti(IV) ratio, the thermal decomposition of the gel can be drastically shortened and the profile's course changed. Gel structure and chemical changes in the gel upon heating are also studied by means of off-line FTIR. A unidentate coordination of the titanium(IV) ion by the carboxylate group of the glycolato ligands and the involvement of the hydroxyl group is confirmed. Phase formation at certain points in the thermal decomposition is studied by X-ray diffraction and Raman spectroscopy. Finally, it is proven that the new precursor is a valuable candidate for the deposition of low carbon containing solution-gel films which can ultimately be converted into smooth and uniform TiO 2 films.

  18. Carbon black selection from simulated broth solution for ADU gel spheres

    International Nuclear Information System (INIS)

    Chai, Jeong Kyung; Ho, Eom Sung; Kim, Yeon Ku; Cho, Moon Seoung

    2012-01-01

    The VHTR (Very High Temperature Gas Reactor) is one of the reactor concepts in the Gen IV International Collaboration. The nuclear fuel of a VHTR in the US is based on microspheres containing a mixture of UO 2 and UC 2 coated with multi carbon layers and a SiC layer. This mixture is called a 'UCO (uranium oxi carbide)' kernel. The fabrication process of this kernel was based on the sol-gel method between an ADUN and HMTA and urea, a process referred to as internal gelation. UCO kernel microspheres were first prepared at ORNL in the late 1970s. CB(Carbon Black) as a carbon source in the final UCO kernel is added during the broth solution preparation, in the processing of UCO kernel fabrication. The preparation of a good quality UCO kernel is very difficult due to the homogeneous distribution of carbon in a UCO kernel. The key requirement to obtain a good quality kernel is a uniform distribution of carbon in the ADU gel sphere forming process before the thermal treatment, i.e., during the gel formation step. The internal gelation concept was adapted in ADU gel sphere fabrication in the ORNL process of the US. Generally, UO 2 kernel microspheres are prepared by an internal gelation method (USA, India) or external gelation method (Germany, China, Japan). The UCO kernel microspheres prepared only in the US, use an internal gelation method. A material flow chart on the preparation of the microsphere kernel is simply shown in Fig. 1. The broth solution preparation, the raw material, additives, and thermal steps such as calcining and sintering processes were different to compared with the external gelation and internal gelation methods. In this study, we first carried out the matching CB selection experiments among the various kinds of CBs in a broth solution, for UCO kernel preparation using an external gelation method.

  19. persimmon tannin-formaldehyde gel decontamination of dilute aqueous solutions

    International Nuclear Information System (INIS)

    Omar, H.A.

    2009-01-01

    in the present work, the extracted juice of unripe astringent persimmon fruit, designated as (kakishibu) was found to have an extremely high affinity for uranium ion. to develop efficient adsorbent for uranium ion the juice was immobilized in formaldehyde. the removal of uranium ion onto the formed gel was found to be affected by several factors such as, concentration of formaldehyde in gel, equilibration time, solution ph, concentration of uranium ion, mass of adsorbent, presence of some cations and anions . the sorption isotherm was discussed in the light of Freundlich and Langmuir models. from Freundlich equation, the exponent 1/n was found in the range of 1>1/n 0 , δS 0 and δG 0 were calculated . the capacity of adsorbent was also determined by column technique and found to 20.20 mg/g

  20. Action of plant root exudates in bioremediations: a review

    Directory of Open Access Journals (Sweden)

    Peter Dundek

    2011-01-01

    Full Text Available This work presents a summary of literature dealing with the use of plant root exudates in bioremediations. Bioremediation using plants (phytoremediation or rhizoremediation and associate rhizosphere to decontaminate polluted soil is a method based on the catabolic potential of root-associated microorganisms, which are supported by the organic substrates released from roots. These substrates are called “root exudates”. Root exudates support metabolism of pollutants-decomposing microorganisms in the rhizosphere, and affect sorption / desorption of pollutants. Awareness of exudation rates is necessary for testing soil decontamination. Commonly, water-soluble root exudates of different plants are studied for their qualitative composition which should be related to total carbon of exuded water-soluble compounds. This paper presents the determined rate of plant root exudation and the amount of root exudates carbon used to form artificial rhizosphere.

  1. The origin and composition of cucurbit "phloem" exudate.

    Science.gov (United States)

    Zhang, Cankui; Yu, Xiyan; Ayre, Brian G; Turgeon, Robert

    2012-04-01

    Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem.

  2. Exudate gums: occurrence, production, and applications.

    Science.gov (United States)

    Verbeken, D; Dierckx, S; Dewettinck, K

    2003-11-01

    This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.

  3. Thermal decomposition and spectroscopic investigation of a new aqueous glycolato(-peroxo) Ti(IV) solution-gel precursor

    Energy Technology Data Exchange (ETDEWEB)

    De Dobbelaere, Christopher, E-mail: christopher.dedobbelaere@uhasselt.be [Hasselt University, Institute for Materials Research, Inorganic and Physical Chemistry, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Mullens, Jules, E-mail: jules.mullens@uhasselt.be [Hasselt University, Institute for Materials Research, Inorganic and Physical Chemistry, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Hardy, An, E-mail: an.hardy@uhasselt.be [Hasselt University, Institute for Materials Research, Inorganic and Physical Chemistry, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Van Bael, Marlies K., E-mail: marlies.vanbael@uhasselt.be [Hasselt University, Institute for Materials Research, Inorganic and Physical Chemistry, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium)

    2011-06-10

    Highlights: {yields} A totally water based glycolato-Ti(IV) precursor is presented and characterized. {yields} The precursors' thermal decomposition profile depends on the ligand to metal ratio. {yields} Titanium is coordinated in an unidentate fashion by the glycolate anion. {yields} Smooth and uniform TiO{sub 2} films can be prepared from the precursor solution. - Abstract: A new aqueous solution-gel precursor based on water soluble glycolato(-peroxo)-Ti(IV) complexes is developed for the preparation of TiO{sub 2} films. With regard to the decomposition of complexes towards oxide formation, it is important to gain insight in the chemical transformations inside the precursor during thermal treatment. Therefore, the thermo-oxidative decomposition pathway of a gel obtained by slow evaporation of the precursor solution is described based on hyphenated thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). Pure glycolic acid is used as a reference system for this study. By varying the molar glycolic acid to Ti(IV) ratio, the thermal decomposition of the gel can be drastically shortened and the profile's course changed. Gel structure and chemical changes in the gel upon heating are also studied by means of off-line FTIR. A unidentate coordination of the titanium(IV) ion by the carboxylate group of the glycolato ligands and the involvement of the hydroxyl group is confirmed. Phase formation at certain points in the thermal decomposition is studied by X-ray diffraction and Raman spectroscopy. Finally, it is proven that the new precursor is a valuable candidate for the deposition of low carbon containing solution-gel films which can ultimately be converted into smooth and uniform TiO{sub 2} films.

  4. Automated detection of exudates for diabetic retinopathy screening

    International Nuclear Information System (INIS)

    Fleming, Alan D; Philip, Sam; Goatman, Keith A; Williams, Graeme J; Olson, John A; Sharp, Peter F

    2007-01-01

    Automated image analysis is being widely sought to reduce the workload required for grading images resulting from diabetic retinopathy screening programmes. The recognition of exudates in retinal images is an important goal for automated analysis since these are one of the indicators that the disease has progressed to a stage requiring referral to an ophthalmologist. Candidate exudates were detected using a multi-scale morphological process. Based on local properties, the likelihoods of a candidate being a member of classes exudate, drusen or background were determined. This leads to a likelihood of the image containing exudates which can be thresholded to create a binary decision. Compared to a clinical reference standard, images containing exudates were detected with sensitivity 95.0% and specificity 84.6% in a test set of 13 219 images of which 300 contained exudates. Depending on requirements, this method could form part of an automated system to detect images showing either any diabetic retinopathy or referable diabetic retinopathy

  5. Automated detection of exudates for diabetic retinopathy screening

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Alan D [Biomedical Physics, University of Aberdeen, Aberdeen, AB25 2ZD (United Kingdom); Philip, Sam [Diabetes Retinal Screening Service, David Anderson Building, Foresterhill Road, Aberdeen, AB25 2ZP (United Kingdom); Goatman, Keith A [Biomedical Physics, University of Aberdeen, Aberdeen, AB25 2ZD (United Kingdom); Williams, Graeme J [Diabetes Retinal Screening Service, David Anderson Building, Foresterhill Road, Aberdeen, AB25 2ZP (United Kingdom); Olson, John A [Diabetes Retinal Screening Service, David Anderson Building, Foresterhill Road, Aberdeen, AB25 2ZP (United Kingdom); Sharp, Peter F [Biomedical Physics, University of Aberdeen, Aberdeen, AB25 2ZD (United Kingdom)

    2007-12-21

    Automated image analysis is being widely sought to reduce the workload required for grading images resulting from diabetic retinopathy screening programmes. The recognition of exudates in retinal images is an important goal for automated analysis since these are one of the indicators that the disease has progressed to a stage requiring referral to an ophthalmologist. Candidate exudates were detected using a multi-scale morphological process. Based on local properties, the likelihoods of a candidate being a member of classes exudate, drusen or background were determined. This leads to a likelihood of the image containing exudates which can be thresholded to create a binary decision. Compared to a clinical reference standard, images containing exudates were detected with sensitivity 95.0% and specificity 84.6% in a test set of 13 219 images of which 300 contained exudates. Depending on requirements, this method could form part of an automated system to detect images showing either any diabetic retinopathy or referable diabetic retinopathy.

  6. Automated detection of exudates for diabetic retinopathy screening

    Science.gov (United States)

    Fleming, Alan D.; Philip, Sam; Goatman, Keith A.; Williams, Graeme J.; Olson, John A.; Sharp, Peter F.

    2007-12-01

    Automated image analysis is being widely sought to reduce the workload required for grading images resulting from diabetic retinopathy screening programmes. The recognition of exudates in retinal images is an important goal for automated analysis since these are one of the indicators that the disease has progressed to a stage requiring referral to an ophthalmologist. Candidate exudates were detected using a multi-scale morphological process. Based on local properties, the likelihoods of a candidate being a member of classes exudate, drusen or background were determined. This leads to a likelihood of the image containing exudates which can be thresholded to create a binary decision. Compared to a clinical reference standard, images containing exudates were detected with sensitivity 95.0% and specificity 84.6% in a test set of 13 219 images of which 300 contained exudates. Depending on requirements, this method could form part of an automated system to detect images showing either any diabetic retinopathy or referable diabetic retinopathy.

  7. Gel chromatographic behavior of Tc-99m-labeled compounds in aqueous solution

    International Nuclear Information System (INIS)

    Suzuki, T.; Wagner, H.N. Jr.; Burns, H.D.; Dannals, F.F.

    1984-01-01

    The purpose of this study was to elucidate the interaction of Tc-99m-labeled compounds (Tc-99m 0/sub 4/-bar, Tc-99m glucoheptonate, Tc-99m DTPA, Tc-99m disofenin) with the chromatographic gels, to determine their relative molecular sizes and molecular structures in aqueous solution, which are based on their biomenbrane transport mechanism and quality control analysis. Each Tc-99m-labeled compound was eluted and analyzed by three different gel chromatrography systems varying buffers: Sephadex G-25, Sephadex LH-20 and Bio-Gel P-4. The best separation between the elution peaks of all compounds except Tc-99m glucoheptonate was achieved on Sephadex G-25 in methanol-0.025OM Tris-HCL buffer (pH 7.6) (1:1) which could avoid the aromatic interaction with the gels. Tc-99m glucoheptonate was well eluted only on a Bio-Gel P-4 column but its elution peak was not separated from other compounds' peaks. The elution of Tc-99m disofenin was delayed on Sephadex G-25 gel and Bio-Gel P-4 columns in 0.9% NaCl and Tris-HCl buffer(ph 7.6) and on Sephadex LH-20 column in methanol-Tris-HCl buffer, because of the aromatic ring interaction with the gels. The relative molecular size index ( Kav ) calculated from the elution volume of the gel chromatography. Kav of Tc-99m 0/sub 4/-bar(MW=163), Tc-99m DTPA (MW=492?) and TC-99m disofenin (MW=707) on Sephadex G-25 in methanol-0.025OM Tris-HCl buffer(pH 7.6) (1:1), which was the most suitable combination of the gel and the buffer, were 0.976, 0.477 and 0.200, respectively. They inversely correlated with their estimated molecular weight. The interaction of Tc-99m-labeled compounds with the chromatographic gels should be considered in quality control procedure for Tc-99m radiopharamaceuticals

  8. In situ characterization of Ti-peroxy gel during formation on titanium surfaces in hydrogen peroxide containing solutions

    International Nuclear Information System (INIS)

    Muyco, Julie J.; Gray, Jeremy J.; Ratto, Timothy V.; Orme, Christine A.; McKittrick, Joanna; Frangos, John

    2006-01-01

    Three possible functions of Ti-peroxy gel are: reduction of the inflammatory response through the reduction of hydrogen peroxide and other reactive oxygen species; creation of a favorable surface for calcium phosphate nucleation; and as a transitional layer between the compliant surrounding tissue and the stiff titanium. Traditional surface characterization techniques operate in high vacuum environments that alter the actual sample-solution interface. Our studies used techniques that allowed samples to remain in solution and be observed over time. Atomic force microscopy (AFM) force-distance curves, electrochemical impedance spectroscopy (EIS), and Raman spectroscopy were each used in situ to define kinetic and mechanical properties of Ti-peroxy gel as it formed over time on titanium during exposure to hydrogen peroxide. Our studies enabled us to monitor real-time changes in the native oxide layer on titanium in hydrogen peroxide containing solution, including the formation of a Ti-peroxy gel layer above the native oxide. Peaks attributed to Ti-peroxy gel were seen to emerge over the course of several hours using in situ Raman spectroscopy. Force-distance curves suggest a layer that thickens with time on the titanium sample surface. EIS data showed that changes in the surface layers could be monitored in solution over time

  9. Spectroscopic characterization of the oxyferrous complex of prostacyclin synthase in solution and in trapped sol–gel matrix

    Science.gov (United States)

    Yeh, Hui-Chun; Hsu, Pei-Yung; Tsai, Ah-Lim; Wang, Lee-Ho

    2010-01-01

    Prostacyclin synthase (PGIS) is a member of the cytochrome P450 family in which the oxyferrous complexes are generally labile in the absence of substrate. At 4 °C, the on-rate constants and off-rate constants of oxygen binding to PGIS in solution are 5.9 × 105 m−1 ·s−1 and 29 s−1, respectively. The oxyferrous complex decays to a ferric form at a rate of 12 s−1. We report, for the first time, a stable oxyferrous complex of PGIS in a transparent sol–gel monolith. The encapsulated ferric PGIS retained the same spectroscopic features as in solution. The binding capabilities of the encapsulated PGIS were demonstrated by spectral changes upon the addition of O-based, N-based and C-based ligands. The peroxidase activity of PGIS in sol–gel was three orders of magnitude slower than that in solution owing to the restricted diffusion of the substrate in sol–gel. The oxyferrous complex in sol–gel was observable for 24 h at room temperature and displayed a much red-shifted Soret peak. Stabilization of the ferrous–carbon monoxide complex in sol–gel was observed as an enrichment of the 450-nm species over the 420-nm species. This result suggests that the sol–gel method may be applied to other P450s to generate a stable intermediate in the di-oxygen activation. PMID:18397321

  10. Optical and rheological studies on weak gel-sol transition in aqueous solutions of poly(N-isopropylacrylamide-block-polystyrene

    Directory of Open Access Journals (Sweden)

    S. Sanjeevi Prasath

    2017-07-01

    Full Text Available The optical and rheological properties of aqueous solutions of block copolymer composed of low molecular weight poly(N-isopropylacrylamide-b-polystyrene are studied as a function of temperature. From light scattering measurements the block copolymer solution is found to form micelles at very low concentrations and the critical micellar concentration is identified as 0.005 wt%. Apart from the concentration dependence, a unique temperature dependent micelle formation is noted at 34 °C. Further, temperature dependent refractive index measurements shows that the refractive index increases with temperature (beyond the lower critical solution temperature, 31.6 °C of the polymer, and is attributed to the stable rearrangement of the proximal hydrophobic isopropyl-polystyrene chains in the collapsed polymer so as to overcome the steric hindrance effects offered by the hydrophobic chains. In the polymer concentrations investigated for rheological studies, the solution flows, yet manifested solid like behavior with G' > G" with the modulus being frequency dependent and the magnitude of G' two-fold higher than G" implying a weak gel state. Weak gel states are in general noted at high temperatures in most of the polymer systems, contrary to this, in our studies weak gel state is observed at lower temperature. Further, a transition from weak gel to sol state is observed at slightly elevated temperatures. The reason for the existence of weak gel state below the lower critical solution temperature is due to the micellar entanglements of poly(N-isopropylacrylamide-b-polystyrene with one another and whereas above the lower critical solution temperature disentanglement of the micelles makes the system behave like a viscoelastic liquid.

  11. Effects of Tomato Root Exudates on Meloidogyne incognita.

    Directory of Open Access Journals (Sweden)

    Guodong Yang

    Full Text Available Plant root exudates affect root-knot nematodes egg hatch. Chemicals in root exudates can attract nematodes to the roots or result in repellence, motility inhibition or even death. However, until recently little was known about the relationship between tomato root exudates chemicals and root-knot nematodes. In this study, root exudates were extracted from three tomato rootstocks with varying levels of nematode resistance: Baliya (highly resistant, HR, RS2 (moderately resistant, MR and L-402 (highly susceptible, T. The effects of the root exudates on Meloidogyne incognita (M. incognita egg hatch, survival and chemotaxis of second-stage juveniles (J2 were explored. The composition of the root exudates was analysed by gas chromatography/mass spectrometry (GC/MS prior to and following M. incognita inoculation. Four compounds in root exudates were selected for further analysis and their allopathic effect on M. incognita were investigated. Root exudates from each tomato rootstocks (HR, MR and T strains suppressed M. incognita egg hatch and increased J2 mortality, with the highest rate being observed in the exudates from the HR plants. Exudate from HR variety also repelled M. incognita J2 while that of the susceptible plant, T, was demonstrated to be attractive. The relative amount of esters and phenol compounds in root exudates from HR and MR tomato rootstocks increased notably after inoculation. Four compounds, 2,6-Di-tert-butyl-p-cresol, L-ascorbyl 2,6-dipalmitate, dibutyl phthalate and dimethyl phthalate increased significantly after inoculation. The egg hatch of M. incognita was suppressed by each of the compound. L-ascorbyl 2,6-dipalmitate showed the most notable effect in a concentration-dependent manner. All four compounds were associated with increased J2 mortality. The greatest effect was observed with dimethyl phthalate at 2 mmol·L-1. Dibutyl phthalate was the only compound observed to repel M. incognita J2 with no effect being detected in

  12. In situ observation of sol-gel transition of agarose aqueous solution by fluorescence measurement.

    Science.gov (United States)

    Wang, Zheng; Yang, Kun; Li, Haining; Yuan, Chaosheng; Zhu, Xiang; Huang, Haijun; Wang, Yongqiang; Su, Lei; Fang, Yapeng

    2018-06-01

    Sol-gel transition behavior of agarose aqueous solution was investigated by using rheology and fluorescence measurement. On heating, the storage modulus G' decreased gradually, then deviated abruptly at the temperature of about 65°C, and finally decreased slowly again. For fluorescence measurement, the phase transition point kept almost at the temperature of 65°C, which was consistent with that in rheology measurement. Upon compression, it was indicated that the fluorescence lifetime for the probe in the agarose aqueous solution showed a dramatic change in the vicinity of the phase transition point. T vs. P phase diagram of agarose aqueous solution was constructed, which showed that the melting point was an increasing function of pressure. Based on the phase diagram, the agarose gels were prepared by cooling under atmospheric pressure and the pressure of 300MPa, respectively. From the result of the recovered samples studied by optical rheometry, it was found that agarose gel prepared under high pressure had a higher elasticity and lower viscosity index, compared with that under atmospheric pressure. It could be speculated that such kinds of properties might be attributed to the smaller pore size during gelation under high pressure. Copyright © 2018. Published by Elsevier B.V.

  13. Characterization of diverse soybean genotypes using 14 carbon for organic acid exudation under phosphorus stress and its relationship with phosphorus acquisition efficiency

    International Nuclear Information System (INIS)

    Vengavasi, Krishnapriya; Pandey, Renu

    2017-01-01

    To characterise the physiological aspects influencing organic acid exudation under low phosphorus (P) stress, experiment was conducted to screen a diverse soybean panel (comprising 116 genotypes) for total carbon exudation employing shoot labelling with 14 CO 2 technique. Among the traits measured at seedling stage, total carbon ( 14 C) exudation, P uptake and total dry weight contributed to the maximum genotypic variability in soybean. The proportion of organic acids (including oxalate, citrate, succinate and fumarate) was the highest among root-exuded compounds induced by low P stress in soybean. Improved root length, surface area and volume coupled with higher activity of enzymes in TCA cycle contributed to enhanced organic acid exudation under low P. Efficient soybean genotypes (EC-232019 and G-2344) exhibited superior growth and P acquisition efficiency under low soil P availability attributed to its higher root exudation potential aiding in mining fixed soil P. To understand the molecular mechanism differentially regulating root exudation potential in contrasting genotypes (EC-232019 and EC-113396), root proteome analysis at low P stress was carried out. Among the total proteins visualised by 2D-gel electrophoresis, 105 genotypes (32%) were differentially expressed between sufficient and low P levels. A total of 44 (14%) proteins were down-regulated by more than two-fold while 61 (15%) proteins were up-regulated by more than two-fold at low P. The differential proteins were involved in a myriad of functions including organic acid accumulation, carbohydrate, protein and lipid metabolism under low P stress. Characterisation of 17 proteins with unknown function indicated the role of novel genes under low P stress. The identified genotypes have potential to be used as donors in crop improvement programs to develop high-yielding P-efficient cultivars which may be an asset to low-input sustainable agriculture. (author)

  14. Agarose gel shift assay reveals that calreticulin favors substrates with a quaternary structure in solution

    DEFF Research Database (Denmark)

    Boelt, Sanne Grundvad; Houen, Gunnar; Højrup, Peter

    2015-01-01

    Here we present an agarose gel shift assay that, in contrast to other electrophoresis approaches, is loaded in the center of the gel. This allows proteins to migrate in either direction according to their isoelectric points. Therefore, the presented assay enables a direct visualization, separation...... structure. It is also demonstrated that the agarose gel shift assay is useful in the study of other protein interactions and can be used as an alternative method to native polyacrylamide gel electrophoresis....... measure of interactions. Therefore, no interaction studies between calreticulin and substrates in solution have been investigated previously. The results presented here indicate that calreticulin has a preference for substrates with a quaternary structure and primarily β-sheets in their secondary...

  15. Solution properties of targacanthin (water-soluble part of gum tragacanth exudate from Astragalus gossypinus).

    Science.gov (United States)

    Mohammadifar, Mohammad Amin; Musavi, Seyed Mohammad; Kiumarsi, Amir; Williams, Peter A

    2006-02-28

    Solution properties of tragacanthin (the water-soluble part of gum tragacanth) were studied by gel permeation chromatography (GPC) combined with multi-angle light scattering and viscometry at 25 degrees C. Photon correlation spectroscopy was used to determine the hydrodynamic radius. Ultrasonic degradation was applied to obtain biopolymer fractions of different molecular weights. The dependence of intrinsic viscosity [eta] and radius of gyration (s2)z(1/2) on weight average molecular mass M(w) for this biopolymer were found to be [eta] = 9.077 x 10(-5) M(w)(0.87) (dL g(-1)) and (s2)z(1/2) in the range of M(w) from 1.8 x 10(5) to 1.6 x 10(6). The conformational parameters of tragacanthin were calculated to be 1111 nm for molar mass per unit contour length (M(L)), 26 nm for persistence length (q) and 1.87 ratio of R(g)/R(h). It was found that the Smidsrød parameter B, the empirical stiffness parameter was 0.013, which is lower than that of several polysaccharides indicating the stiff backbone for tragacanthin. The rheological behavior of aqueous solutions of gum tragacanth and its insoluble and soluble fractions (bassorin and tragacanthin, respectively) were studied. For concentrations equal to 1%, at 25 degrees C and in the absence of salt, bassorin solution showed the highest viscosity and shear thinning behaviour. Power law and Williamson models were used to describe the rheological behaviour of bassorin and tragacanthin, respectively. Oscillatory shear experiments showed a gel like structure for the bassorin but for tragacanthin the oscillatory data were as would be expected for semi-dilute to concentrated solution of entangled, random coil polymers. NaCl changed the steady and oscillatory rheological properties of both fractions and in this way the final viscosity of bassorin was even less than tragacanthin. The calculated activation energy for bassorin and tragacanthin indicated a more rapid decrease in viscosity with temperature for tragacanthin. The plot of

  16. INFLUENCE OF QUARTZ CERAMICS SINGLE-STAGE PROCESSING BY GEL-FORMING WATER SOLUTIONS ON ITS STRENGTH

    Directory of Open Access Journals (Sweden)

    S. K. Evstropiev

    2014-09-01

    Full Text Available The main research results of the influence of quartz ceramics processing by silicon- and aluminum-containing gel- forming water solutions on its durability and porosity are given. Aqueous-alcoholic solutions based on tetraethoxysilane (TEOS, Si(C2H5O4 with additives of aluminum nitrate are proposed for impregnation of porous quartz ceramics samples. Ceramic samples are being impregnated with solutions at the room temperature for 12 minutes. After impregnation they are being exposed to drying at the room temperature for 24 hours and heat treatment in the electric muffle furnace. The made experiments show that impregnation of quartz ceramics porous samples by gel-forming solutions leads to durability growth of not burned samples by 6-7 times even without additional heat treatment. High-temperature heat treatment of previously impregnated ceramic samples leads to decomposition of aluminum nitrate and removal of fossils, and also to hardening of the formed additional bonds between material particles. It considerably improves strength characteristics of quartz ceramics as well. Thus, the possibility of considerable hardening of porous quartz ceramics and stability growth of its strength properties by preliminary impregnation of silicon- and aluminum-bearing gel-forming solutions even without additional heat treatment is experimentally shown. It is revealed that impregnation of porous quartz ceramic samples by these solutions leads only to insignificant reduction of porosity of samples. Subsequent heat treatment of the impregnated porous ceramic samples at the temperatures, equal to 900-1200oC, results in additional significant increase in their mechanical durability.

  17. Dosimetric evaluation of spectrophotometric response of alanine gel solution for gamma, photons, electrons and thermal neutrons radiations

    International Nuclear Information System (INIS)

    Silva, Cleber Feijo

    2009-01-01

    Alanine Gel Dosimeter is a new gel material developed at IPEN that presents significant improvement on Alanine system developed by Costa. The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. This work aims to analyse the main dosimetric characteristics this new gel material for future application to measure dose distribution. The performance of Alanine gel solution was evaluated to gamma, photons, electrons and thermal neutrons radiations using the spectrophotometry technique. According to the obtained results for the different studied radiation types, the reproducibility intra-batches and inter-batches is better than 4% and 5%, respectively. The dose response presents a linear behavior in the studied dose range. The response dependence as a function of dose rate and incident energy is better 2% and 3%, respectively. The lower detectable dose is 0.1 Gy. The obtained results indicate that the Alanine gel dosimeter presents good performance and can be useful as an alternative dosimeter in the radiotherapy area, using MRI technique for tridimensional dose distribution evaluation. (author)

  18. Micelles and gels of oxyethylene-oxybutylene diblock copolymers in aqueous solution: The effect of oxyethylene-block length

    DEFF Research Database (Denmark)

    Derici, L.; Ledger, S.; Mai, S.M.

    1999-01-01

    and in aqueous 0.2 mol dm(-3) K(2)SO(4)), yielding the micellar association numbers, the hydrodynamic and thermodynamic radii, and related expansion factors. Micellar parameters were also obtained by small-angle neutron scattering (SANS) for solutions of a similar copolymer, E(86)B(10), in water, i......Block copolymer E(90)B(10) (E = oxyethylene, B = oxybutylene) was synthesised and characterised by gel permeation chromatography and (13)C NMR spectroscopy. Dynamic light scattering (DLS) and static light scattering (SLS) were used to characterise the micelles in solution (both in water...... of water in the micelle core. Moderately concentrated solutions of copolymer E(90)B(10) were studied in the gel state by small-angle X-ray scattering (SAXS) in tandem with rheology (oscillatory shear). Values for the dynamic elastic modulus (G') of the gels significantly exceeded 10(4) Pa across the range...

  19. The administration of L-thyroxine as soft gel capsule or liquid solution.

    Science.gov (United States)

    Vita, Roberto; Fallahi, Poupak; Antonelli, Alessandro; Benvenga, Salvatore

    2014-07-01

    Levothyroxine (l-T4) is the mainstay of treating hypothyroidism. The tablet is the traditional formulation of l-T4. Tablet l-T4 malabsorption results from either hindered gastric dissolution of the tablet or binding of l-T4 by sequestrants in the intestinal lumen. This review provides an overview of the pharmacokinetics of l-T4 formulations available in the market: the tablet, the soft gel capsule and the oral solution. We review literature on the new formulations and anticipate the areas of future research. Failure of l-T4 treatment to reach target serum thyroid-stimulating hormone levels generally prompts the physicians to increase l-T4 daily dose. In vitro studies have shown that the soft gel capsule releases the active ingredient more consistently at varying pH than the tablet. In addition, in vivo studies have confirmed the in vitro data and have demonstrated that both the soft gel capsule and the liquid formulation are capable to solve tablet l-T4 malabsorption caused by certain drugs, bariatric surgery or coffee. These new formulations may be attractive also for patients who cannot/do not want to change their (improper) habits of l-T4 ingestion. Finally, the oral solution l-T4 could be suitable for patients who cannot swallow the solid formulations.

  20. Impact of Microcystis aeruginosa Exudate on the Formation and Reactivity of Iron Oxide Particles Following Fe(II) and Fe(III) Addition.

    Science.gov (United States)

    Garg, Shikha; Wang, Kai; Waite, T David

    2017-05-16

    Impact of the organic exudate secreted by a toxic strain of Microcystis aeruginosa on the formation, aggregation, and reactivity of iron oxides that are formed on addition of Fe(II) and Fe(III) salts to a solution of the exudate is investigated in this study. The exudate has a stabilizing effect on the particles formed with decreased aggregation rate and increased critical coagulant concentration required for diffusion-limited aggregation to occur. These results suggest that the presence of algal exudates from Microcystis aeruginosa may significantly influence particle aggregation both in natural water bodies where Fe(II) oxidation results in oxide formation and in water treatment where Fe(III) salts are commonly added to aid particle growth and contaminant capture. The exudate also affects the reactivity of iron oxide particles formed with exudate coated particles undergoing faster dissolution than bare iron oxide particles. This has implications to iron availability, especially where algae procure iron via dissolution of iron oxide particles as a result of either reaction with reducing moieties, light-mediated ligand to metal charge transfer and/or reaction with siderophores. The increased reactivity of exudate coated particles is attributed, for the most part, to the smaller size of these particles, higher surface area and increased accessibility of surface sites.

  1. Identification of proteins in a human pleural exudate using two-dimensional preparative liquid-phase electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Nilsson, C L; Puchades, M; Westman, A; Blennow, K; Davidsson, P

    1999-01-01

    Pleural effusion may occur in patients suffering from physical trauma or systemic disorders such as infection, inflammation, or cancer. In order to investigate proteins in a pleural exudate from a patient with severe pneumonia, we used a strategy that combined preparative two-dimensional liquid-phase electrophoresis (2-D LPE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and Western blotting. Preparative 2-D LPE is based on the same principles as analytical 2-D gel electrophoresis, except that the proteins remain in liquid phase during the entire procedure. In the first dimension, liquid-phase isoelectric focusing allows for the enrichment of proteins in liquid fractions. In the Rotofor cell, large volumes (up to 55 mL) and protein amounts (up to 1-2 g) can be loaded. Several low abundance proteins, cystatin C, haptoglobin, transthyretin, beta2-microglobulin, and transferrin, were detected after liquid-phase isoelectric focusing, through Western blotting analysis, in a pleural exudate (by definition, >25 g/L total protein). Direct MALDI-TOF-MS analysis of proteins in a Rotofor fraction is demonstrated as well. MALDI-TOF-MS analysis of a tryptic digest of a continuous elution sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) fraction confirmed the presence of cystatin C. By applying 2-D LPE, MALDI-TOF-MS, and Western blotting to the analysis of this pleural exudate, we were able to confirm the identity of proteins of potential diagnostic value. Our findings serve to illustrate the usefulness of this combination of methods in the analysis of pathological fluids.

  2. Examination of the concrete from an old Portuguese dam: Texture and composition of alkali-silica gel

    International Nuclear Information System (INIS)

    Fernandes, Isabel; Noronha, Fernando; Teles, Madalena

    2007-01-01

    Exudations and pop-outs were identified in the interior galleries of a large dam built in the 1960s. The samples collected were examined by a Scanning Electron Microscope. A dense material with a smooth surface and drying shrinkage cracks or a spongy texture were observed in the samples. The semi-quantitative composition was obtained by energy dispersive spectrometry (EDS) and it was concluded that this material corresponds to alkali-silica gel, composed of SiO 2 -Na 2 O-K 2 O-CaO. A viscous white product in contact with an aggregate particle in a cone sampled from a pop-out was observed through use of the scanning electron microscope and it has characteristics similar to the gel present in the exudations and cavities. Reference is made to the potential alkali reactivity of the aggregate present in the concrete. The texture and composition of the products probably resulting from an alkali-silica reaction are presented, set out in ternary diagrams, and discussed

  3. How Plant Root Exudates Shape the Nitrogen Cycle.

    Science.gov (United States)

    Coskun, Devrim; Britto, Dev T; Shi, Weiming; Kronzucker, Herbert J

    2017-08-01

    Although the global nitrogen (N) cycle is largely driven by soil microbes, plant root exudates can profoundly modify soil microbial communities and influence their N transformations. A detailed understanding is now beginning to emerge regarding the control that root exudates exert over two major soil N processes - nitrification and N 2 fixation. We discuss recent breakthroughs in this area, including the identification of root exudates as nitrification inhibitors and as signaling compounds facilitating N-acquisition symbioses. We indicate gaps in current knowledge, including questions of how root exudates affect newly discovered microbial players and N-cycle components. A better understanding of these processes is urgent given the widespread inefficiencies in agricultural N use and their links to N pollution and climate change. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Clinical efficacy of new aloe vera- and myrrh-based oral mucoadhesive gels in the management of minor recurrent aphthous stomatitis: a randomized, double-blind, vehicle-controlled study.

    Science.gov (United States)

    Mansour, Ghada; Ouda, Soliman; Shaker, Ahmed; Abdallah, Hossam M

    2014-07-01

    To evaluate the clinical efficacy, and safety of newly customized natural oral mucoadhesive gels, containing either aloe vera or myrrh as active ingredients, in the management of minor recurrent aphthous stomatitis (MiRAS). Ninety subjects with MiRAS were recruited from Oral Medicine Clinic, at Faculty of Dentistry, King Abdulaziz University, Saudi Arabia, for this randomized, double-blind, placebo-controlled study. Two new natural gels, containing aloe vera and myrrh, were prepared in a concentration of (0.5% w/w), in addition to a plain mucoadhesive gel used as a placebo. Patients with fresh ulcers (aloe gel showed complete ulcer healing, 86.7%, and 80% of them revealed subsidence of erythema and exudation, respectively, especially at day 6 visit, whereas 76.7% of myrrh-treated patients revealed almost absence of pain at day 6. No side effects were encountered with the use of any of the three gels. The new formulated aloe- and myrrh-based gels proved to be effective in topical management of MiRAS. Aloe was superior in decreasing ulcer size, erythema, and exudation; whereas myrrh resulted in more pain reduction. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. A review on exudates detection methods for diabetic retinopathy.

    Science.gov (United States)

    Joshi, Shilpa; Karule, P T

    2018-01-01

    The presence of exudates on the retina is the most characteristic symptom of diabetic retinopathy. As exudates are among early clinical signs of DR, their detection would be an essential asset to the mass screening task and serve as an important step towards automatic grading and monitoring of the disease. Reliable identification and classification of exudates are of inherent interest in an automated diabetic retinopathy screening system. Here we review the numerous early studies that used for automatic exudates detection with the aim of providing decision support in addition to reducing the workload of an ophthalmologist. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Transudative vs exudative pleural effusions: differentiation using Gd-DTPA-enhanced MRI

    International Nuclear Information System (INIS)

    Frola, C.; Cantoni, S.; Turtulici, I.; Leoni, C.; Loria, F.; Gaeta, M.; Derchi, L.E.

    1997-01-01

    The aim of this study was to investigate the capability of Gd-DTPA-enhanced MRI to differentiate between exudative and transudative pleural effusions. An MRI examination was performed on 22 patients with different types of pleural effusion (10 transudative and 12 exudative effusions). T1-weighted SE images were obtained before and 20 min after administration of Gd-DTPA (0.1 mmol/kg). The degree of enhancement of pleural effusions was evaluated both by visual assessement and by quantitative analysis of images. None of 10 transudative effusions showed significative enhancement, whereas 10 of 12 exudative effusions showed enhancement (sensitivity 83 %, specificity 100 %, positive predictive value 100 %). The postcontrast signal intensity ratios (SIRs) of exudates were significantly higher than corresponding precontrast ratios (P = 0.0109) and the postcontrast SIRs of exudates were significantly higher than those of transudates (P = 0.0300). Exudative pleural effusions show a significant enhancement following administration of Gd-DTPA. We presume that this may be caused by increased pleural permeability and more rapid passage of a large amount of Gd-DTPA from the blood into the pleural fluid in case of exudative effusions. In our limited group of patients, signal enhancement proved the presence of an exudative effusion. Absence of signal enhancement suggests a transudate, but does not exclude an exudate. (orig.). With 5 figs., 2 tabs

  7. Optical signal response pf the alanine gel solution for photons and electrons clinical beams;Resposta espectrofotometrica da solucao gel de alanina para feixes clinicos de fotons e eletrons

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo; Campos, Leticia Lucente [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The measure technique is based on the transformation of ferrous ions (Fe{sup 2+}) in ferric ions (Fe{sup 3+}) after irradiation. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an aminoacid tissue equivalent that improves the production of ferric ions in the solution. This work aims to study the comparison of optical signal response of the alanine gel solution for photons and electrons clinical beams. It was observed that the calibration factor can be considered independent of quality of the radiation for photons and electrons clinical beams. Therefore, it can be used the same calibration factor for evaluating the absorbed dose in photons and electrons fields in the energy of 6 MeV. Alanine Gel Dosimeter presents good performance and can be useful as alternative dosimeter in the radiotherapy area using MRI technique for 3D dose distribution evaluation. (author)

  8. Phosphorus acquisition by citrate- and phytase-exuding Nicotiana tabacum plant mixtures depends on soil phosphorus availability and root intermingling.

    Science.gov (United States)

    Giles, Courtney D; Richardson, Alan E; Cade-Menun, Barbara J; Mezeli, Malika M; Brown, Lawrie K; Menezes-Blackburn, Daniel; Darch, Tegan; Blackwell, Martin Sa; Shand, Charles A; Stutter, Marc I; Wendler, Renate; Cooper, Patricia; Lumsdon, David G; Wearing, Catherine; Zhang, Hao; Haygarth, Philip M; George, Timothy S

    2018-03-02

    Citrate and phytase root exudates contribute to improved phosphorus (P) acquisition efficiency in Nicotiana tabacum (tobacco) when both exudates are produced in a P deficient soil. To test the importance of root intermingling in the interaction of citrate and phytase exudates, Nicotiana tabacum plant-lines with constitutive expression of heterologous citrate (Cit) or fungal phytase (Phy) exudation traits were grown under two root treatments (roots separated or intermingled) and in two soils with contrasting soil P availability. Complementarity of plant mixtures varying in citrate efflux rate and mobility of the expressed phytase in soil was determined based on plant biomass and P accumulation. Soil P composition was evaluated using solution 31 P NMR spectroscopy. In the soil with limited available P, positive complementarity occurred in Cit+Phy mixtures with roots intermingled. Root separation eliminated positive interactions in mixtures expressing the less mobile phytase (Aspergillus niger PhyA) whereas positive complementarity persisted in mixtures that expressed the more mobile phytase (Peniophora lycii PhyA). Soils from Cit+Phy mixtures contained less inorganic P and more organic P compared to monocultures. Exudate-specific strategies for the acquisition of soil P were most effective in P-limited soil and depended on citrate efflux rate and the relative mobility of the expressed phytase in soil. Plant growth and soil P utilization in plant systems with complementary exudation strategies are expected to be greatest where exudates persist in soil and are expressed synchronously in space and time. This article is protected by copyright. All rights reserved.

  9. Solution-processable electrochemiluminescent ion gels for flexible, low-voltage, emissive displays on plastic.

    Science.gov (United States)

    Moon, Hong Chul; Lodge, Timothy P; Frisbie, C Daniel

    2014-03-05

    Ion gels comprising ABA triblock copolymers and ionic liquids have received much attention as functional materials in numerous applications, especially as gate dielectrics in organic transistors. Here we have expanded the functionality of ion gels by demonstrating low-voltage, flexible electrochemiluminescent (ECL) devices using patterned ion gels containing redox-active luminophores. The ECL devices consisted only of a 30 μm thick emissive gel and two electrodes and were fabricated on indium tin oxide-coated substrates (e.g., polyester) simply by solution-casting the ECL gel and brush-painting a top Ag electrode. The triblock copolymer employed in the gel was polystyrene-block-poly(methyl methacrylate)-block-polystyrene, where the solvophobic polystyrene end blocks associate into micellar cross-links in the versatile ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). An ECL gel containing ~6.25 wt % Ru(bpy)3Cl2 (relative to [EMI][TFSI]) as the luminophore turned on at an AC peak-to-peak voltage as low as 2.6 V (i.e., -1.3 to +1.3 V) and showed a relatively rapid response (sub-ms). The wavelength of maximum emission was 610 nm (red-orange). With the use of an iridium(III) complex, Ir(diFppy)2(bpy)PF6 [diFppy = 2-(2',4'-difluorophenyl)pyridine; bpy = 2,2'-bipyridyl], the emitting color was tuned to a maximum wavelength of 540 nm (green). Moreover, when a blended luminophore system containing a 60:40 mixture of Ru(bpy)3(2+) and Ir(diFppy)2(bpy)(+) was used in the emissive layer, the luminance of red-orange-colored light was enhanced by a factor of 2, which is explained by the generation of the additional excited state Ru(bpy)3(2+)* by a coreactant pathway with Ir(diFppy)2(bpy)(+)* in addition to the usual annihilation pathway. This is the first time that enhanced ECL has been achieved in ion gels (or ionic liquids) using a coreactant. Overall, the results indicate that ECL ion gels are attractive multifunctional materials for

  10. Comparison of Drug Concentrations in Human Aqueous Humor after the Administration of 0.3% Gatifloxacin Ophthalmic Gel, 0.3% Gatifloxacin and 0.5% Levofloxacin Ophthalmic Solutions.

    Science.gov (United States)

    Ding, Wenting; Ni, Weiling; Chen, Huilian; Yuan, Jingqun; Huang, Xiaodan; Zhang, Zheng; Wang, Yao; Yu, Yibo; Yao, Ke

    2015-01-01

    To investigate the penetration of 0.3% gatifloxacin ophthalmic gel, 0.3% gatifloxacin ophthalmic solution and 0.5% levofloxacin ophthalmic solution into aqueous humor after topical application. Age-related cataract patients (150 eyes in 150 cases) receiving phacoemulsification were randomly divided into three groups: a 0.3% gatifloxacin gel group (n=50), a 0.3% gatifloxacin solution group (n=50), and a 0.5% levofloxacin solution group (n=50). Each group was administered one drop of gel or solution every 15 minutes for four doses. Aqueous samples were collected at different time points after the last drop. High pressure liquid chromatography (HPLC) was applied to determine the concentrations. The one-way ANOVA analysis was performed. Our data indicated that the concentration of the gatifloxacin gel group was higher than that of the gatifloxacin solution group at all time points (P solution group at 120.0 min and 180.0 min (Psolutions reached their peak values at 60.0 min. 0.3% gatifloxacin ophthalmic gel application produced highest aqueous humor drug concentration, maintained the longest time, had the best penetration and bioavailability.

  11. The Origin and Composition of Cucurbit “Phloem” Exudate1[OA

    Science.gov (United States)

    Zhang, Cankui; Yu, Xiyan; Ayre, Brian G.; Turgeon, Robert

    2012-01-01

    Cucurbits exude profusely when stems or petioles are cut. We conducted studies on pumpkin (Cucurbita maxima) and cucumber (Cucumis sativus) to determine the origin and composition of the exudate. Morphometric analysis indicated that the exudate is too voluminous to derive exclusively from the phloem. Cold, which inhibits phloem transport, did not interfere with exudation. However, ice water applied to the roots, which reduces root pressure, rapidly diminished exudation rate. Sap was seen by microscopic examination to flow primarily from the fascicular phloem in cucumber, and several other cucurbit species, but primarily from the extrafascicular phloem in pumpkin. Following exposure of leaves to 14CO2, radiolabeled stachyose and other sugars were detected in the exudate in proportions expected of authentic phloem sap. Most of this radiolabel was released during the first 20 s. Sugars in exudate were dilute. The sugar composition of exudate from extrafascicular phloem near the edge of the stem differed from that of other sources in that it was high in hexose and low in stachyose. We conclude that sap is released from cucurbit phloem upon wounding but contributes negligibly to total exudate volume. The sap is diluted by water from cut cells, the apoplast, and the xylem. Small amounts of dilute, mobile sap from sieve elements can be obtained, although there is evidence that it is contaminated by the contents of other cell types. The function of P-proteins may be to prevent water loss from the xylem as well as nutrient loss from the phloem. PMID:22331409

  12. The variation of root exudates from the hyperaccumulator Sedum alfredii under cadmium stress: metabonomics analysis.

    Directory of Open Access Journals (Sweden)

    Qing Luo

    Full Text Available Hydroponic experiments were conducted to investigate the variation of root exudates from the hyperaccumulator Sedum alfredii under the stress of cadmium (Cd. S. alfredii was cultured for 4 days in the nutrient solution spiked with CdCl2 at concentrations of 0, 5, 10, 40, and 400 µM Cd after the pre-culture. The root exudates were collected and analyzed by GC-MS, and 62 compounds were identified. Of these compounds, the orthogonal partial least-squares discrimination analysis (OPLS-DA showed that there were a distinct difference among the root exudates with different Cd treatments and 20 compounds resulting in this difference were found out. Changing tendencies in the relative content of these 20 compounds under the different Cd treatments were analyzed. These results indicated that trehalose, erythritol, naphthalene, d-pinitol and n-octacosane might be closely related to the Cd stabilization, phosphoric acid, tetradecanoic acid, oxalic acid, threonic acid and glycine could be attributed to the Cd mobilization, and mannitol, oleic acid, 3-hydroxybutanoic acid, fructose, octacosanol and ribitol could copy well with the Cd stress.

  13. Bioavailable concentrations of germanium and rare earth elements in soil as affected by low molecular weight organic acids and root exudates

    Science.gov (United States)

    Wiche, Oliver; Székely, Balázs; Kummer, Nicolai-Alexeji; Heinemann, Ute; Tesch, Silke; Heilmeier, Hermann

    2014-05-01

    Availability of elements in soil to plant is generally dependent on the solubility and mobility of elements in soil solution which is controlled by soil, elemental properties and plant-soil interactions. Low molecular organic acids or other root exudates may increase mobility and availability of certain elements for plants as an effect of lowering pH in the rhizosphere and complexation. However, these processes take place in a larger volume in soil, therefore to understand their nature, it is also important to know in which layers of the soil what factors modify these processes. In this work the influence of citric acid and root exudates of white lupin (Lupinus albus L.) on bioavailable concentrations of germanium, lanthan, neodymium, gadolinium and erbium in soil solution and uptake in root and shoot of rape (Brassica napus L.), comfrey (Symphytum officinale L.), common millet (Panicum milliaceum L.) and oat (Avena sativa L.) was investigated. Two different pot experiments were conducted: (1) the mentioned plant species were treated with nutrient solutions containing various amount of citric acid; (2) white lupin was cultivated in mixed culture (0 % lupin, 33 % lupin) with oat (Avena sativa L.) and soil solution was obtained by plastic suction cups placed at various depths. As a result, addition of citric acid significantly increased germanium concentrations in plant tissue of comfrey and rape and increased translocation of germanium, lanthan, neodymium, gadolinium and erbium from root to shoot. The cultivation of white lupin in mixed culture with oat led to significantly higher concentrations of germanium and increasing concentrations of lanthan, neodymium, gadolinium and erbium in soil solution and aboveground plant tissue. In these pots concentrations of citric acid in soil solution were significantly higher than in the control. The results show, that low molecular organic acids exuded by plant roots are of great importance for the mobilization of germanium

  14. Plant exudates promote PCB degradation by a rhodococcal rhizobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Toussaint, Jean-Patrick; Pham, Thi Thanh My; Barriault, Diane; Sylvestre, Michel [Instiut National de la Recherche Scientifique INRS, Laval, QC (Canada). Inst. Armand-Frappier

    2012-09-15

    Rhodococcus erythropolis U23A is a polychlorinated biphenyl (PCB)-degrading bacterium isolated from the rhizosphere of plants grown on a PCB-contaminated soil. Strain U23A bphA exhibited 99% identity with bphA1 of Rhodococcus globerulus P6. We grew Arabidopsis thaliana in a hydroponic axenic system, collected, and concentrated the plant secondary metabolite-containing root exudates. Strain U23A exhibited a chemotactic response toward these root exudates. In a root colonizing assay, the number of cells of strain U23A associated to the plant roots (5.7 x 105 CFU g{sup -1}) was greater than the number remaining in the surrounding sand (4.5 x 104 CFU g{sup -1}). Furthermore, the exudates could support the growth of strain U23A. In a resting cell suspension assay, cells grown in a minimal medium containing Arabidopsis root exudates as sole growth substrate were able to metabolize 2,3,4'- and 2,3',4-trichlorobiphenyl. However, no significant degradation of any of congeners was observed for control cells grown on Luria-Bertani medium. Although strain U23A was unable to grow on any of the flavonoids identified in root exudates, biphenyl-induced cells metabolized flavanone, one of the major root exudate components. In addition, when used as co-substrate with sodium acetate, flavanone was as efficient as biphenyl to induce the biphenyl catabolic pathway of strain U23A. Together, these data provide supporting evidence that some rhodococci can live in soil in close association with plant roots and that root exudates can support their growth and trigger their PCB-degrading ability. This suggests that, like the flagellated Gram-negative bacteria, non-flagellated rhodococci may also play a key role in the degradation of persistent pollutants. (orig.)

  15. Sol-Gel Manufactured Energetic Materials

    Science.gov (United States)

    Simpson, Randall L.; Lee, Ronald S.; Tillotson, Thomas M.; Hrubesh, Lawrence W.; Swansiger, Rosalind W.; Fox, Glenn A.

    2005-05-17

    Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

  16. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    Science.gov (United States)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds, incorporating treatments examining biological decomposition of the exudates. When these exudates were added to a sandy loam soil, contact angle and drop penetration time increased exponentially with increasing exudate concentration. These wetting properties were strongly correlated with both exudate density and zero-shear viscosity, but not with exudate surface tension. Water holding capacity and water repellency of exudate mixed soil tremendously increased with exudate concentration, however they were significantly reduced on decomposition when measured after 14 days of incubation at 16C. Mechanical stability greatly increased with increasing exudate amendment to soils, which was assessed using a rheological amplitude sweep test near saturation, at -50 cm matric potential (field capacity) using indentation test, and at air-dry condition using the Brazilian test. This reflects that exudates not only attenuate plant water stress but also impart mechanical stability to the rhizosphere. These data are highly relevant to the understanding and modelling of rhizosphere development, which is the next phase of our research.

  17. Evolutionary Divergences in Root Exudate Composition among Ecologically-Contrasting Helianthus Species.

    Science.gov (United States)

    Bowsher, Alan W; Ali, Rifhat; Harding, Scott A; Tsai, Chung-Jui; Donovan, Lisa A

    2016-01-01

    Plant roots exude numerous metabolites into the soil that influence nutrient availability. Although root exudate composition is hypothesized to be under selection in low fertility soils, few studies have tested this hypothesis in a phylogenetic framework. In this study, we examined root exudates of three pairs of Helianthus species chosen as phylogenetically-independent contrasts with respect to native soil nutrient availability. Under controlled environmental conditions, seedlings were grown to the three-leaf-pair stage, then transferred to either high or low nutrient treatments. After five days of nutrient treatments, we used gas chromatography-mass spectrometry for analysis of root exudates, and detected 37 metabolites across species. When compared in the high nutrient treatment, species native to low nutrient soils exhibited overall higher exudation than their sister species native to high nutrient soils in all three species pairs, providing support for repeated evolutionary shifts in response to native soil fertility. Species native to low nutrient soils and those native to high nutrient soils responded similarly to low nutrient treatments with increased exudation of organic acids (fumaric, citric, malic acids) and glucose, potentially as a mechanism to enhance nutrition acquisition. However, species native to low nutrient soils also responded to low nutrient treatments with a larger decrease in exudation of amino acids than species native to high nutrient soils in all three species pairs. This indicates that species native to low nutrient soils have evolved a unique sensitivity to changes in nutrient availability for some, but not all, root exudates. Overall, these repeated evolutionary divergences between species native to low nutrient soils and those native to high nutrient soils provide evidence for the adaptive value of root exudation, and its plasticity, in contrasting soil environments.

  18. Metabolomics of meat exudate: Its potential to evaluate beef meat conservation and aging

    International Nuclear Information System (INIS)

    Castejón, David; García-Segura, Juan Manuel; Escudero, Rosa; Herrera, Antonio; Cambero, María Isabel

    2015-01-01

    In this study we analyzed the exudate of beef to evaluate its potential as non invasive sampling for nuclear magnetic resonance (NMR) based metabolomic analysis of meat samples. Exudate, as the natural juice from raw meat, is an easy to obtain matrix that it is usually collected in small amounts in commercial meat packages. Although meat exudate could provide complete and homogeneous metabolic information about the whole meat piece, this sample has been poorly studied. Exudates from 48 beef samples of different breeds, cattle and storage times have been studied by "1H NMR spectroscopy. The liquid exudate spectra were compared with those obtained by High Resolution Magic Angle Spinning (HRMAS) of the original meat pieces. The close correlation found between both spectra (>95% of coincident peaks in both registers; Spearman correlation coefficient = 0.945) lead us to propose the exudate as an excellent alternative analytical matrix with a view to apply meat metabolomics. 60 metabolites could be identified through the analysis of mono and bidimensional exudate spectra, 23 of them for the first time in NMR meat studies. The application of chemometric tools to analyze exudate dataset has revealed significant metabolite variations associated with meat aging. Hence, NMR based metabolomics have made it possible both to classify meat samples according to their storage time through Principal Component Analysis (PCA), and to predict that storage time through Partial Least Squares (PLS) regression. - Highlights: • NMR spectra from beef samples and their exudates are very strongly correlated. • 23 metabolites not reported in previous NMR meat studies have been identified. • Meat exudate NMR spectra allow monitoring of biochemical changes related to aging. • PCA of exudate NMR spectra classified meat samples by their storage time. • The aging of a meat sample can be predicted by PLS analysis of its exudate.

  19. Metabolomics of meat exudate: Its potential to evaluate beef meat conservation and aging

    Energy Technology Data Exchange (ETDEWEB)

    Castejón, David [Centro de Asistencia a la Investigación de Resonancia Magnética Nuclear y de Espín Electrónico, Universidad Complutense de Madrid, 28040 Madrid (Spain); García-Segura, Juan Manuel [Centro de Asistencia a la Investigación de Resonancia Magnética Nuclear y de Espín Electrónico, Universidad Complutense de Madrid, 28040 Madrid (Spain); Departamento de Bioquímica y Biología Molecular I, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Escudero, Rosa [Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria. Universidad Complutense de Madrid, 28040 Madrid (Spain); Herrera, Antonio [Departamento de Química Orgánica, Facultad de Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Cambero, María Isabel, E-mail: icambero@vet.ucm.es [Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria. Universidad Complutense de Madrid, 28040 Madrid (Spain)

    2015-12-11

    In this study we analyzed the exudate of beef to evaluate its potential as non invasive sampling for nuclear magnetic resonance (NMR) based metabolomic analysis of meat samples. Exudate, as the natural juice from raw meat, is an easy to obtain matrix that it is usually collected in small amounts in commercial meat packages. Although meat exudate could provide complete and homogeneous metabolic information about the whole meat piece, this sample has been poorly studied. Exudates from 48 beef samples of different breeds, cattle and storage times have been studied by {sup 1}H NMR spectroscopy. The liquid exudate spectra were compared with those obtained by High Resolution Magic Angle Spinning (HRMAS) of the original meat pieces. The close correlation found between both spectra (>95% of coincident peaks in both registers; Spearman correlation coefficient = 0.945) lead us to propose the exudate as an excellent alternative analytical matrix with a view to apply meat metabolomics. 60 metabolites could be identified through the analysis of mono and bidimensional exudate spectra, 23 of them for the first time in NMR meat studies. The application of chemometric tools to analyze exudate dataset has revealed significant metabolite variations associated with meat aging. Hence, NMR based metabolomics have made it possible both to classify meat samples according to their storage time through Principal Component Analysis (PCA), and to predict that storage time through Partial Least Squares (PLS) regression. - Highlights: • NMR spectra from beef samples and their exudates are very strongly correlated. • 23 metabolites not reported in previous NMR meat studies have been identified. • Meat exudate NMR spectra allow monitoring of biochemical changes related to aging. • PCA of exudate NMR spectra classified meat samples by their storage time. • The aging of a meat sample can be predicted by PLS analysis of its exudate.

  20. Enhancement of phloem exudation from Fraxinus uhdei Wenz. (evergreen ash) using ethylenediaminetetraacetic acid

    International Nuclear Information System (INIS)

    Costello, L.R.; Bassham, J.A.; Calvin, M.

    1982-01-01

    Ethylenediaminetetraacetic acid (EDTA) enhanced the exudation of 14 C-labeled assimilates from excised leaflets and whole plant specimens of Fraxinus uhdei Wenz. A 2 millimolar EDTA concentration was found to be most effective in promoting exudation from excised leaflets, while 10 millimolar EDTA was most effective in whole plants experiments. Exudation rate reached a maximum after 24 hours in both experiments. The continuous presence of EDTA throughout the treatment period was required for maximum exudation from excised leaflets. Stachyose, raffinose, verbascose, and sucrose were the principal compounds found to occur in exudate samples. These compounds are typically transported in sieve elements of various Fraxinus species suggesting the exudate was of phloem orgin. Electron microscope studies of petiolule sieve plate pores from excisd leaflets showed substantially less callose appearing after treatment with EDTA than after H 2 O treatment. It is suggested that EDTA enhances phloem exudation by inhibiting or reducing callose formation in sieve plate pores. The exudation enhancement technique described for whole plant specimens is suggested as a useful means of collecting phloem sap and studying translocation in woody plants

  1. Differentiation of exudative and transudative pleural effusion : MR appearances

    International Nuclear Information System (INIS)

    Kim, Tae Hoon; Lee, Sang Yoon; Kang, Ho Yeong; Kim, Soo Rhan; Yang, Sang Kyu; Shin, So Young; Lee, Shin Hyung; Lee, Chang Joon

    1996-01-01

    The purpose of this study is to determine whether MR images after intravenous administration of Gd-DTPA can differentiate exudative and transudative pleural effusion. We studied 18 patients with ten exudative and eight transudative pleural effusions diagnosed clinically and by thoracentesis. We analysed the relationship between T1 value(normalized to fat) and the ratio of effusion/serum protein of pleural effusion. We also assessed the contrast enhancement of exudative and transudative pleural effusion on T1 weighted SE images taken at 15 and 30minutes after administration of Gd-DTPA. The relationship between the effusion/serum protein ratio and T1 value(normalized to fat) was statistically not significant(r=0.27, P=0.381). On precontrast spin-echo T1WI, mean signal intensity of the transudate was 0.18(±0.04) and that of the exudate was 0.24(±0.07), values which were not significant differences(P>0.05). Postcontrast mean signal intensities of transudates at 15 and 30 were 0.20±0.06 and 0.26±0.08, respectively, values which were not significantly higher than that of precontrast mean signal intensity(P<0.05). Postcontrast mean signal intensity values of exudative pleural effusions at 15 and 30 minutes(0.32±0.06 and 0.39±0.06, respectively) were, on the other hand, significantly higher than that of precontrast mean signal intensity(P<0.05). Postcontrast T1-weighted SE images at 15 and 30 minutes can be helpful in the differentiation of transudative and exudative pleural effusion

  2. Exudative Retinal Detachment Treatment in a Patient with Thrombotic Thrombocytopenic Purpura

    Directory of Open Access Journals (Sweden)

    Magali Sampo

    2016-02-01

    Full Text Available Purpose: We report a case of unilateral exudative retinal detachment in a patient with thrombotic thrombocytopenic purpura (TTP, without associated hypertension, successfully treated with plasmapheresis. Case Report: A 46-year-old woman with a medical history of TTP presented with unilateral exudative retinal detachment. Biological and radiological assessment eliminated other causes of exudative retinal detachment, including hypertension. Plasma exchange was performed, followed by a rapid improvement in visual acuity and total disappearance of serous detachment. Conclusion: Exudative unilateral retinal detachment is a rare complication of TTP and can be successfully treated by plasma exchange.

  3. Chemical composition of essential oil of exudates of Dryobalanops ...

    African Journals Online (AJOL)

    Purpose: To identify the chemical composition of essential oil from the exudates of Dryobalanops aromatica from Malaysia. Methods: Exudate was collected from D. aromatica and subjected to fractional distillation to obtain essential oil. Gas chromatography-mass spectrometry (GC-MS) was used to characterize the ...

  4. Removal of lindane from an aqueous solution by using aminopropyl silica gel-immobilized calix[6]arene.

    Science.gov (United States)

    Tor, Ali; Aydin, Mehmet Emin; Aydin, Senar; Tabakci, Mustafa; Beduk, Fatma

    2013-11-15

    An aminopropyl silica gel-immobilized calix[6]arene (C[6]APS) has been used for the removal of lindane from an aqueous solution in batch sorption technique. The C[6]APS was synthesized with p-tert-butylcalix[6]arene hexacarboxylate derivative and aminopropyl silica gel in the presence of N,N'-diisopropyl carbodiimide coupling reagent. The sorption study was carried out as functions of solution pH, contact time, initial lindane concentration, C[6]APS dosage and ionic strength of solution. The matrix effect of natural water samples on the sorption efficiency of C[6]APS was also investigated. Maximum lindane removal was obtained at a wide pH range of 2-8 and sorption equilibrium was achieved in 2h. The isotherm analysis indicated that the sorption data can be represented by both Langmuir and Freundlich isotherm models. Increasing ionic strength of the solutions increased the sorption efficiency and matrix of natural water samples had no effect on the sorption of lindane. By using multilinear regression model, regression equation was also developed to explain the effects of the experimental variables. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Physicochemical properties of radiation-sterilized honey alginate wound dressing for exudating wounds

    International Nuclear Information System (INIS)

    Asa, Anie Day DC.; De Guzman, Zenaida M.; Baldos, Davison T.; Asaad, Celia O.

    2013-01-01

    Honey is a well-known natural cure in promoting healing of wounds. Alginate, on the other hand, is a polysaccharide with pharmaceutical applications such as wound dressing and control release drugs. Calcium-alginate wound dressings have a gel-forming capability. in that, upon ion exchange between calcium ions in the dressing, and sodium ions in wound fluid, the dressing transforms into a gel. Cross-linked alginate gels can absorb would fluid, and also maintain a moist environment to the wound area. Combined with anti-microbial properties of honey and absorption and gelling properties of alginate, a honey alginate wound dressing is developed and irradiated for sterility. Its physicochemical properties are then analyzed. The honey-alginate wound dressing has lower pH (4.40±0.02) than alginate alone dressings (5.40±0.04) which is more favorable for wound healing. The dressing also has low moisture content (10.25±1.11%). Analysis of moisture vapour transmission rate shows a general increase with time for 48 hours. The wound dressing also has an absorbency of 19.00±1.80 g/100 cm 2 with a gel fraction of 18.44±0.63%. The rate of absorption analysis, meanwhile, shows a very rapid absorption rate upon exposure to wound fluid. After some time, a decrease in rate is observed which is accounted to the release of honey to the wound environment. For tensile strength, irradiation causes an effect in tensile strength in machine direction but is insignificant for cross machine direction. Physicochemical properties of the radiation-sterilized honey alginate wound dressing e.g. acidic pH, absorbency, moisture vapor permeability and absorption rate ascertain its characteristic as a good wound dressing for exudating wounds. Its low moisture content, meanwhile, allows for longer shelf-life of the developed product. (author)

  6. LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

    Science.gov (United States)

    Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

    2010-06-01

    This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29-83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.

  7. Familial Exudative Vitreoretinopathy.

    Science.gov (United States)

    Sızmaz, Selçuk; Yonekawa, Yoshihiro; T Trese, Michael

    2015-08-01

    Familial exudative vitreoretinopathy (FEVR) is a hereditary disease associated with visual loss, particularly in the pediatric group. Mutations in the NDP, FZD4, LRP5, and TSPAN12 genes have been shown to contribute to FEVR. FEVR has been reported to have X-linked recessive, autosomal dominant, and autosomal recessive inheritances. However, both the genotypic and phenotypic features are variable. Novel mutations contributing to the disease have been reported. The earliest and the most prominent finding of the disease is avascularity in the peripheral retina. As the disease progresses, retinal neovascularization, subretinal exudation, partial and total retinal detachment may occur, which may be associated with certain mutations. With early diagnosis and prompt management visual loss can be prevented with laser photocoagulation and anti-VEGF injections. In case of retinal detachment, pars plana vitrectomy alone or combined with scleral buckling should be considered. Identifying asymptomatic family members with various degrees of insidious findings is of certain importance. Wide-field imaging with fluorescein angiography is crucial in the management of this disease. The differential diagnosis includes other pediatric vitreoretinopathies such as Norrie disease, retinopathy of prematurity, and Coats' disease.

  8. Familial Exudative Vitreoretinopathy

    Directory of Open Access Journals (Sweden)

    Selçuk Sızmaz

    2015-08-01

    Full Text Available Familial exudative vitreoretinopathy (FEVR is a hereditary disease associated with visual loss, particularly in the pediatric group. Mutations in the NDP, FZD4, LRP5, and TSPAN12 genes have been shown to contribute to FEVR. FEVR has been reported to have X-linked recessive, autosomal dominant, and autosomal recessive inheritances. However, both the genotypic and phenotypic features are variable. Novel mutations contributing to the disease have been reported. The earliest and the most prominent finding of the disease is avascularity in the peripheral retina. As the disease progresses, retinal neovascularization, subretinal exudation, partial and total retinal detachment may occur, which may be associated with certain mutations. With early diagnosis and prompt management visual loss can be prevented with laser photocoagulation and anti-VEGF injections. In case of retinal detachment, pars plana vitrectomy alone or combined with scleral buckling should be considered. Identifying asymptomatic family members with various degrees of insidious findings is of certain importance. Wide-field imaging with fluorescein angiography is crucial in the management of this disease. The differential diagnosis includes other pediatric vitreoretinopathies such as Norrie disease, retinopathy of prematurity, and Coats’ disease. (Turk J Ophthalmol 2015; 45: 164-168

  9. Recurrent Exudative Pleural Effusion with Flare up of Chronic ...

    African Journals Online (AJOL)

    We describe herein a young male patient who presented with exudative pleural effusion that appeared with flare up of chronic HBV infection and spontaneously recovered with the clinical and biochemical improvement of the hepatitis on two occasions five months apart. Other causes of hepatitis and exudative pleural ...

  10. ASSOCIATION BETWEEN RETINAL HARD EXUDATES AND DYSLIPIDEMIA IN TYPE 2 DIABETIC PATIENTS IN RURAL KARNATAKA

    Directory of Open Access Journals (Sweden)

    Arun Kumar B.

    2015-10-01

    Full Text Available AIM: To evaluate the association of elevated serum lipids with retinal hard exudates in type 2 diabetic patients in rural Karnataka. MATERIAL AND METHODS : Hospital based cross sectional study which included 60 (n=60 type 2 diabetic patients (60 eyes fulfilling the inclusion criteria. Patients were subjected to detailed ocular examination, fundus examination done under full dilatation using indirect ophth almoscope with 20D lens and slit lamp biomicroscope with 90D lens. Fundus photographs were obtained using fundus camera. Grading of retinal hard exudates performed by utilizing modified Airlie House classification. The modified Airlie House Classification used is as follows: Grade 0 - No evidence of hard exudates; Grade 1 : Questionable hard exudates present; Grade 2 : Hard exudates less than standard photograph 3; Grade 3 : Hard exudates greater than or equal to standard photograph 3, but less than standard p hotograph 5; Grade 4 : Hard exudates greater than or equal to standard photograph 5, but less than standard photograph 4 and Grade 5 : Hard exudates greater than or equal to standard photograph 4. These grades were further divided into three groups of patie nt severity as follows: Group 1 (absent or minimal hard exudates included patients with Grade 0, 1 or 2 hard exudates; Group 2 (hard exudates present included patients with Grade 3 or 4 hard exudates and Group 3 (prominent hard exudates included patient s with Grade 5 hard exudates. Fasting lipid profile including serum total cholesterol, low density lipoproteins, very low density lipoproteins, high density lipoproteins and triglycerides was obtained. Association of dyslipidemia with retinal hard exudates was analysed using one way ANOVA test. RESULTS: On statistical analysis with ANOVA test retinal hard exudates were significantly associated with elevated total cholesterol (p= .0001, triglycerides (p= .0001, serum LDL (p=.008, serum VLDL (p=.012, and negative correlation was found

  11. Comparative study on the effects of negatively-charged biopolymers on chitosan-based gels for the development of instantaneous gels

    International Nuclear Information System (INIS)

    Jimeno, Austin Ed B.; Chakraborty, Soma

    2015-01-01

    Polymeric electrolytic complexes are solutions of charged/ionized chains. These solutions of positive and negative charge can be combined to make instantaneous networks bonded by electrostatic interactions, a gel network. These electrostatic interaction allows for easy application in injectable gels as the network can be temporarily distributed with the application of force and reformed on the relief of it. Possible applications for these injectable gels include drug delivery and wound-healing. κ-Carrageenan, dextran sulfate, alginate, and chitosan are polyelectrolytic biocompatible polymers which are widely studied and used for a variety of biomedical applications. Gel networks are made by combining a negatively-charged (κ-Carrageenan, dextran sulfate, or alginate) and positively charged (chitosan) solutions. The strong electrostatic interaction between the opposite charges from the gel network and the inherent biocompatibility of the polymers allow future biomedical applications. Quat 188-modified chitosan has additional sites for electrostatic bonding, can be dissolved in neutral, basic, and acidic pH, and has shown inherent antibacterial activity. The objectives of this study are the following: to formulate chitosan-based gels mixing solutions of chitosan with solutions of either κ-Carrageenan, dextran sulfate, or alginate, study the gelation of the gels as function of time and pH (4, 7, and 9) using UV-Vis, characterize the chitosan-based gels through DSC and DMA, characterize the physiological degradation of the chitosan-based gels, and compare results with those from Quat 188-modified chitosan-based gels. Polyelectrolytic solutions of chitosan and negatively-charged biopolymer of similar viscosities were mixed. It was determined from the UV-Vis spectroscopy of the chitosan-carrageenan gels under pH7 buffer that the increase of concentration by a factor of 5 for 0.006M-0.0095M and 1.25 for 0.0095M-0.0150M Chitosan-Carrageenan gels improved gelation by the

  12. A stable-isotope mass spectrometry-based metabolic footprinting approach to analyze exudates from phytoplankton

    DEFF Research Database (Denmark)

    Weber, Ralf J. M.; Selander, Erik; Sommer, Ulf

    2013-01-01

    Phytoplankton exudates play an important role in pelagic ecology and biogeochemical cycles of elements. Exuded compounds fuel the microbial food web and often encompass bioactive secondary metabolites like sex pheromones, allelochemicals, antibiotics, or feeding attractants that mediate biological...... interactions. Despite this importance, little is known about the bioactive compounds present in phytoplankton exudates. We report a stable-isotope metabolic footprinting method to characterise exudates from aquatic autotrophs. Exudates from 13C-enriched alga were concentrated by solid phase extraction...

  13. Root Exudate Effect on Germination and Mycelial Growth of ...

    African Journals Online (AJOL)

    The effect of some root exudates on the germination and mycelial growth of sclerotia of Sclerotium rolfsii Sacc. was studied. Root exudates of 5 – 10 days old seedlings from five plants viz: - tomato (Lycopersicum esculenta) maize (Zea mays), garden egg (Solanum melongena), pigeon pea (Cajanus cajan), and pepper ...

  14. Exudation of organic acids by Lupinus albus and Lupinus angustifolius as affected by phosphorus supply

    Science.gov (United States)

    Hentschel, Werner; Wiche, Oliver

    2016-04-01

    In phytomining and phytoremediation research mixed cultures of bioenergy crops with legumes hold promise to enhance availability of trace metals and metalloids in the soil plant system. This is due to the ability of certain legumes to mobilize trace elements during acquisition of nutrients making these elements available for co-cultured species. The legumes achieve this element mobilization by exudating carboxylates and enzymes as well as by lowering the pH value in the rhizosphere. The aim of our research was to determine characteristics and differences in the exudation of Lupinus albus and Lupinus angustifolius regarding to quantitative as to qualitative aspects. Especially the affection by phosphorus (P) supply was a point of interest. Thus we conducted laboratory batch experiments, wherein the plants were grown over four weeks under controlled light, moisture and nutritional conditions on sand as substrate. Half of the plants were supplied with 12 mg P per kg substrate, the other half were cultivated under a total lack of P. After cultivation the plants were transferred from the cultivation substrate into a 0,05 mmolṡL-1 CaCl2 solution. After two hours the plants were removed, moist and dry mass off shoots and roots were measured together with the root length (Tennants' method). Concentrations of exudated carboxylates in the CaCl2 solution were determined via IC (column: Metrosept OrganicAcids, eluent 0.5 molṡL-1 H2SO4 + 15% acetone, pH=3; 0.5 mLṡmin-1). As a result four different organic acids were identified (citric acid, fumaric acid, tartaric acid, malic acid) in concentration ranges of 0.15 mgṡL-1 (fumaric acid) to 9.21 mgṡL-1 (citric acid). Lupinus angustifolius showed a higher exudation rate (in nmol per cm root length per hour) than Lupinus albus in the presence of phosphorus (e.g. regarding citric acid: 1.99 vs 0.64 nmolṡ(gṡh)-1). However, as the root complexity and length of L. albus were far higher than of L. angustifolius, the total

  15. Optical and energy dependent response of the alanine gel solution produced at IPEN to clinical photons and electrons beams

    International Nuclear Information System (INIS)

    Silva, Cleber F.

    2011-01-01

    The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent traditionally used as standard dosimetric material in EPR dosimetry. Recently, it has been studied to be applied in gel dosimetry, considering that the addition of Alanine in the Fricke gel solution improves the production of ferric ions radiation induced. The spectrophotometric evaluation technique can be used comparing the two spectrum wavelengths bands: 457 nm band that corresponds to ferrous ions and 588 nm band that corresponds to ferric ions concentration to evaluate the dosimetric properties of this material. The performance of the Alanine gel solution developed at IPEN has been firstly studied using the spectrophotometric technique aiming to apply this material to 3D clinical doses evaluations using MRI technique. In this work, the optical and the energy dependent response of this solution submitted to clinical photons and electrons beams were studied. Different batches of gel solutions were prepared and maintained at low temperature during 12 h to solidification. Before irradiation, the samples were maintained during 1 h at room temperature. The photons and electrons irradiations were carried out using a Varian 2100C Medical Linear Accelerator of the Radiotherapy Department of the Hospital das Clinicas of the University of Sao Paulo with absorbed doses between 1 and 40 Gy; radiation field of 10 x 10 cm 2 ; photon energies of 6 MeV and 15 MeV; and electron with energies between 6 and 15 MeV. The obtained results indicate that signal response dependence for clinical photons and electrons beams, to the same doses, for Alanine gel dosimeter is better than 3.6 % (1σ), and the energy dependence response, to the same doses, is better 3% (1σ) for both beams. These results indicate that the same calibration factor can be used and the optical response is energy independent in the studied dose range and clinical photons and electrons beams energies. (author)

  16. Transdermal delivery of paeonol using cubic gel and microemulsion gel

    Science.gov (United States)

    Luo, Maofu; Shen, Qi; Chen, Jinjin

    2011-01-01

    Background The aim of this study was to develop new systems for transdermal delivery of paeonol, in particular microemulsion gel and cubic gel formulations. Methods Various microemulsion vehicles were prepared using isopropyl myristate as an oil phase, polyoxyethylated castor oil (Cremophor® EL) as a surfactant, and polyethylene glycol 400 as a cosurfactant. In the optimum microemulsion gel formulation, carbomer 940 was selected as the gel matrix, and consisted of 1% paeonol, 4% isopropyl myristate, 28% Cremophor EL/polyethylene glycol 400 (1:1), and 67% water. The cubic gel was prepared containing 3% paeonol, 30% water, and 67% glyceryl monooleate. Results A skin permeability test using excised rat skins indicated that both the cubic gel and microemulsion gel formulations had higher permeability than did the paeonol solution. An in vivo pharmacokinetic study done in rats showed that the relative bioavailability of the cubic gel and microemulsion gel was enhanced by about 1.51-fold and 1.28-fold, respectively, compared with orally administered paeonol suspension. Conclusion Both the cubic gel and microemulsion gel formulations are promising delivery systems to enhance the skin permeability of paeonol, in particular the cubic gel. PMID:21904450

  17. Automatic Detection of Retinal Exudates using a Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Nualsawat HIRANSAKOLWONG

    2013-02-01

    Full Text Available Retinal exudates are among the preliminary signs of diabetic retinopathy, a major cause of vision loss in diabetic patients. Correct and efficient screening of exudates is very expensive in professional time and may cause human error. Nowadays, the digital retinal image is frequently used to follow-up and diagnoses eye diseases. Therefore, the retinal image is crucial and essential for experts to detect exudates. Unfortunately, it is a normal situation that retinal images in Thailand are poor quality images. In this paper, we present a series of experiments on feature selection and exudates classification using the support vector machine classifiers. The retinal images are segmented following key preprocessing steps, i.e., color normalization, contrast enhancement, noise removal and color space selection. On data sets of poor quality images, sensitivity, specificity and accuracy is 94.46%, 89.52% and 92.14%, respectively.

  18. Automatic detection of retinal exudates in fundus images of diabetic retinopathy patients

    Directory of Open Access Journals (Sweden)

    Mahsa Partovi

    2016-05-01

    Full Text Available Introduction: Diabetic retinopathy (DR is the most frequent microvascular complication of diabetes and can lead to several retinal abnormalities including microaneurysms, exudates, dot and blot hemorrhages, and cotton wool spots. Automated early detection of these abnormalities could limit the severity of the disease and assist ophthalmologists in investigating and treating the disease more efficiently. Segmentation of retinal image features provides the basis for automated assessment. In this study, exudates lesion on retinopathy retinal images was segmented by different image processing techniques. The objective of this study is detection of the exudates regions on retinal images of retinopathy patients by different image processing techniques. Methods: A total of 30 color images from retinopathy patients were selected for this study. The images were taken by Topcon TRC-50 IX mydriatic camera and saves with TIFF format with a resolution of 500 × 752 pixels. The morphological function was applied on intensity components of hue saturation intensity (HSI space. To detect the exudates regions, thresholding was performed on all images and the exudates region was segmented. To optimize the detection efficiency, the binary morphological functions were applied. Finally, the exudates regions were quantified and evaluated for further statistical purposes. Results: The average of sensitivity of 76%, specificity of 98%, and accuracy of 97% was obtained. Conclusion: The results showed that our approach can identify the exudate regions in retinopathy images.

  19. Transcriptomic profiling of Bacillus amyloliquefaciens FZB42 in response to maize root exudates

    LENUS (Irish Health Repository)

    Fan, Ben

    2012-06-21

    AbstractBackgroundPlant root exudates have been shown to play an important role in mediating interactions between plant growth-promoting rhizobacteria (PGPR) and their host plants. Most investigations were performed on Gram-negative rhizobacteria, while much less is known about Gram-positive rhizobacteria. To elucidate early responses of PGPR to root exudates, we investigated changes in the transcriptome of a Gram-positive PGPR to plant root exudates.ResultsBacillus amyloliquefaciens FZB42 is a well-studied Gram-positive PGPR. To obtain a comprehensive overview of FZB42 gene expression in response to maize root exudates, microarray experiments were performed. A total of 302 genes representing 8.2% of the FZB42 transcriptome showed significantly altered expression levels in the presence of root exudates. The majority of the genes (261) was up-regulated after incubation of FZB42 with root exudates, whereas only 41 genes were down-regulated. Several groups of the genes which were strongly induced by the root exudates are involved in metabolic pathways relating to nutrient utilization, bacterial chemotaxis and motility, and non-ribosomal synthesis of antimicrobial peptides and polyketides.ConclusionsHere we present a transcriptome analysis of the root-colonizing bacterium Bacillus amyloliquefaciens FZB42 in response to maize root exudates. The 302 genes identified as being differentially transcribed are proposed to be involved in interactions of Gram-positive bacteria with plants.

  20. THE SYSTEMATIC AND EVOLUTIONARY SIGNIFICANCE OF EXUDATE FLAVONOIDS IN AEONIUM

    NARCIS (Netherlands)

    STEVENS, JF; HART, HT; WOLLENWEBER, E

    Leaf exudates of 32 species of Aeonium were examined for the presence of flavonoids. Thirty two flavonoids were detected in exudates of half of the species. The flavonoids were identified as methyl ethers of kaempferol, 6-hydroxykaempferol, quercetin, myricetin and scutellarein. The distribution of

  1. Preparation of zirconium molybdate gel generator

    International Nuclear Information System (INIS)

    Charoen, S.; Aungurarat, G.; Laohawilai, S.; Sukontpradit, W.; Jingjit, S.

    1994-01-01

    A procedure for preparation of 99mTc generator based on conversion to zirconium molybdate gel of 99Mo produced by neutron activation was reported. The gel was prepared from zirconium oxychloride solution pH 1.6, ammonium molybdate solution pH 3-5 and mole ratio of Zr:Mo 1:1 which had water content about 7-8%. Small generators containing 1-1.5 g of gel were eluted with average efficiencies of 77% and the activity peak in the first 3 ml of 10 ml of saline solution. The amount of Mo and Zr in eluates were below the acceptance limit. The gel generators of activity about 100 mCi were prepared and had the good performance in elutability and stability

  2. Study of the confined solutions properties: case of gel formed during nuclear glass alteration

    International Nuclear Information System (INIS)

    Matar-Briman, I.

    2012-01-01

    In this study, we have investigated the thermodynamic properties, the structure and the dynamics of confined solutions in model gels and in a gel coming from glass alteration. The first step was to determine the structure and the dynamics of pure confined water in porous materials by using nuclear magnetic resonance and neutron scattering. Meso-porous silica was elaborated and grafted by sol-gel route to decrease the pore sizes from 2.7 to 2 nm and to modify pore surfaces to have Si-OH, Zr-OH and Al-OH. The second step involved determining the dynamics of water in leachate confined in the model gels and in the gel of altered glass by using neutron scattering. In the model gels and at a 10 -12 -10 -9 second timescale, two kinds of waters were highlighted: first, an interfacial water linked to the pore surfaces and second, a free water in the pore core. Their ratio depends on the pore size and pore surface composition. Whatever the pore surface, when the pore size decreases the free water ratio in the pore center also decreases. For pores smaller than 2.3 nm and pore surfaces with Zr-OH or Al-OH surfaces, water is strongly linked to the surface and few water molecules are mobile. This is due to the ability of alumina and zirconia to immobilize water molecules through chemical coordination bonds stronger than the physical bonds established between silica and water. The result also highlight that pore surface composition could be the predominant parameter affecting the fixed proton content. Moreover, the mobility of water confined in a leachate is not modified. The study of the water dynamics in a gel formed during alteration of glass constituted of SiO 2 , Al 2 O 3 and CaO, and having a porosity between 2 and 7 nm showed the same behavior as water confined in pores presenting an Al-OH surface. (author) [fr

  3. Organic acids, amino acids compositions in the root exudates and Cu-accumulation in castor (Ricinus communis L.) Under Cu stress.

    Science.gov (United States)

    Huang, Guoyong; Guo, Guangguang; Yao, Shiyuan; Zhang, Na; Hu, Hongqing

    2016-01-01

    Ricinus communis L. is a hyperaccumulation plant newly discovered in an abandoned land of Cu mine in China. A hydroponic experiment was then carried out to determine the root exudates in the Cu-tolerant castor (Ricinus communis L.). Plants were grown in nutrient solution with increasing level of Cu doses (0, 100, 250, 500, and 750 μmol/L Cu) in the form of CuSO4. Cu accumulation in the roots and shoots of castor, and root exudates collected from the castor were measured. The results indicated that the castor had a high Cu accumulation capacity and the Cu concentrations in the shoots and roots of the castor treated with 750 μmol/L Cu were 177.1, 14586.7 mg/kg, respectively. Tartaric was the largest in the root exudates in terms of concentrations, which reached up to 329.13 μmol/g (dry plant) in the level of 750 μmol/L Cu. There was a significantly positive linear relationship between the Cu concentration in root and the concentration of succinic (R = 0.92, P < 0.05), tartaric (R = 0.96, P < 0.01), and citric (R = 0.89, P < 0.05). These results indicated that the difference in root exudation from castor could affect their Cu tolerance. What is more, significant is that the high tartaric and citric, the low oxalic and cysteine in the root exudation of castor contributed to toleration of high Cu concentrations.

  4. Encapsulation of nanoclusters in dried gel materials via an inverse micelle/sol gel synthesis

    Science.gov (United States)

    Martino, Anthony; Yamanaka, Stacey A.; Kawola, Jeffrey S.; Showalter, Steven K.; Loy, Douglas A.

    1998-01-01

    A dried gel material sterically entrapping nanoclusters of a catalytically active material and a process to make the material via an inverse micelle/sol-gel synthesis. A surfactant is mixed with an apolar solvent to form an inverse micelle solution. A salt of a catalytically active material, such as gold chloride, is added along with a silica gel precursor to the solution to form a mixture. To the mixture are then added a reducing agent for the purpose of reducing the gold in the gold chloride to atomic gold to form the nanoclusters and a condensing agent to form the gel which sterically entraps the nanoclusters. The nanoclusters are normally in the average size range of from 5-10 nm in diameter with a monodisperse size distribution.

  5. Chemical Gel for Surface Decontamination

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Moon, J. K.; Won, H. J.; Lee, K. W.; Kim, C. K.

    2010-01-01

    Many chemical decontamination processes operate by immersing components in aggressive chemical solutions. In these applications chemical decontamination technique produce large amounts of radioactive liquid waste. Therefore it is necessary to develop processes using chemical gels instead of chemical solutions, to avoid the well-known disadvantages of chemical decontamination techniques while retaining their high efficiency. Chemical gels decontamination process consists of applying the gel by spraying it onto the surface of large area components (floors, walls, etc) to be decontaminated. The gel adheres to any vertical or complex surface due to their thixotropic properties and operates by dissolving the radioactive deposit, along with a thin layer of the gel support, so that the radioactivity trapped at the surface can be removed. Important aspects of the gels are that small quantities can be used and they show thixitropic properties : liquid during spraying, and solid when stationary, allowing for strong adherence to surfaces. This work investigates the decontamination behaviors of organic-based chemical gel for SS 304 metallic surfaces contaminated with radioactive materials

  6. Interaction of xylem and phloem during exudation and wound occlusion in Cucurbita maxima.

    Science.gov (United States)

    Zimmermann, Matthias R; Hafke, Jens B; van Bel, Aart J E; Furch, Alexandra C U

    2013-01-01

    Collection of cucurbit exudates from cut petioles has been a powerful tool for gaining knowledge on phloem sap composition without full notion of the complex exudation mechanism. Only few publications explicitly mentioned that exudates were collected from the basal side of the cut, which exudes more copiously than the apical side. This is surprising since only exudation from the apical side is supposedly driven by phloem pressure gradients. Composition of carbohydrates and pH values at both wounding sides are equal, whereas protein concentration is higher at the basal side. Apparently, exudation is far more complex than just the delivery of phloem sap. Xylem involvement is indicated by lower protein concentrations after elimination of root pressure. Moreover, dye was sucked into xylem vessels owing to relaxation of negative pressure after cutting. The lateral water efflux from the vessels increases turgor of surrounding cells including sieve elements. Simultaneously, detached parietal proteins (PP1/PP2) induce occlusion of sieve plates and cover wound surface. If root pressure is strong enough, pure xylem sap can be collected after removal of the occlusion plug at the wound surface. The present findings provide a mechanism of sap exudation in Cucurbita maxima, in which the contribution of xylem water is integrated. © 2012 Blackwell Publishing Ltd.

  7. CYTOLOGICAL FEATURES OF FENSPIRIDE USAGE IN TREATMENT OF CHRONIC EXUDATIVE OTITIS MEDIA

    OpenAIRE

    O. Yu. Mezentseva; F. N. Zavjyalov; A. A. Vorobjeva; L. P. Popova; M. V. Rodionova

    2012-01-01

    The cytological investigation of exudates, obtained during tympanostomies, showed the predomination of inflammatory-regenerative cytograms types when using Fenspiride (Eurespal) in treatment of secretory stage of chronic exudative otitis media. Received data confirm, that treatment with this drug shortens the course of exudative otitis media and contributes to more rapid change from destructive to reparative stage of inflammation, which prevents the development of adhesive process in the midd...

  8. Vegetable exudates as food for Callithrix spp. (Callitrichidae: exploratory patterns.

    Directory of Open Access Journals (Sweden)

    Talitha Mayumi Francisco

    Full Text Available Marmosets of the genus Callithrix are specialized in the consumption of tree exudates to obtain essential nutritional resource by boring holes into bark with teeth. However, marmoset preferences for particular tree species, location, type, and other suitable factors that aid in exudate acquisition need further research. In the current study, the intensity of exudate use from Anadenanthera peregrina var. peregrina trees by hybrid marmosets Callithrix spp. groups was studied in five forest fragments in Viçosa, in the state of Minas, Brazil. Thirty-nine A. peregrina var. peregrina trees were examined and 8,765 active and non-active holes were analyzed. The trunk of A. peregrina var. peregrina had a lower number of holes than the canopy: 11% were found on the trunk and 89% were found on the canopy. The upper canopy was the preferred area by Callithrix spp. for obtaining exudates. The intensity of tree exploitation by marmosets showed a moderate-to-weak correlation with diameter at breast height (DBH and total tree height. The overall results indicate that Anadenanthera peregrina var. peregrina provides food resources for hybrid marmosets (Callithrix spp. and these animals prefer to explore this resource on the apical parts of the plant, where the thickness, location, and age of the branches are the main features involved in the acquisition of exudates.

  9. VARIATION IN RHIZOBIUM GROWTH DUE TO SEED AND ROOT EXUDATES RELEASED FROM GAMMA IRRADIATED GLYCINE MAX SEEDS

    International Nuclear Information System (INIS)

    KAMEL, H.A.; ASKER, M.M.S

    2008-01-01

    In this study, seeds of Glycine max Giza 122 were irradiated with gamma rays from 60 Co source at various doses (10 to 200 Gy), sterilized and soaked into an aerated solution of CaSO 4 (1 mmol and pH 6.5). The capacities of the released seed exudates (SEs) and root exudates (REs) to promote Rhizobium leguminosarum growth were investigated as well as biochemical analysis of the exudates was carried out. SE of both control and gamma irradiated seeds resulted in a higher Rhizobium population and polysaccharide production than RE. Relative to control, the highly effective doses in Rhizobium growth and polysaccharide production were 25 and 200 Gy; the former was a promoter while the later was an inhibitor. HPLC analysis of soluble carbohydrates revealed the presence of glucose (Glu), rhamnose (Rha) and fructose (Fru) in the SE and RE. Protein content in SE was lower than that in RE; the highest values were due to 10 Gy and 25 Gy in SE and RE, respectively. Free amino acids content in SE was increased up to 25 Gy then decreased while RE was increased by increasing gamma doses from 10 to 200 Gy

  10. Nature and role of root exudates: Efficacy in bioremediation | Shukla ...

    African Journals Online (AJOL)

    Root exudate is one of the ways for plant communication to the neighboring plant and adjoining of microorganisms present in the rhizosphere of the root. The chemicals ingredients of the root exudates are specific to a particular plant species and also depend on the nearby biotic and abiotic environment. The chemical ...

  11. CYTOLOGICAL FEATURES OF FENSPIRIDE USAGE IN TREATMENT OF CHRONIC EXUDATIVE OTITIS MEDIA

    Directory of Open Access Journals (Sweden)

    O. Yu. Mezentseva

    2012-01-01

    Full Text Available The cytological investigation of exudates, obtained during tympanostomies, showed the predomination of inflammatory-regenerative cytograms types when using Fenspiride (Eurespal in treatment of secretory stage of chronic exudative otitis media. Received data confirm, that treatment with this drug shortens the course of exudative otitis media and contributes to more rapid change from destructive to reparative stage of inflammation, which prevents the development of adhesive process in the middle ear.

  12. Comparative Analysis of Automatic Exudate Detection between Machine Learning and Traditional Approaches

    Science.gov (United States)

    Sopharak, Akara; Uyyanonvara, Bunyarit; Barman, Sarah; Williamson, Thomas

    To prevent blindness from diabetic retinopathy, periodic screening and early diagnosis are neccessary. Due to lack of expert ophthalmologists in rural area, automated early exudate (one of visible sign of diabetic retinopathy) detection could help to reduce the number of blindness in diabetic patients. Traditional automatic exudate detection methods are based on specific parameter configuration, while the machine learning approaches which seems more flexible may be computationally high cost. A comparative analysis of traditional and machine learning of exudates detection, namely, mathematical morphology, fuzzy c-means clustering, naive Bayesian classifier, Support Vector Machine and Nearest Neighbor classifier are presented. Detected exudates are validated with expert ophthalmologists' hand-drawn ground-truths. The sensitivity, specificity, precision, accuracy and time complexity of each method are also compared.

  13. Colloid molecular weight estimation by gel chromatography/acrylamide gel electrophoresis

    International Nuclear Information System (INIS)

    Liberatore, F.A.; Dearborn, C.; Nigam, S.; Poon, C.; Camin, L.; Liteplo, M.

    1984-01-01

    Size or molecular weight (MW) estimation of radiolabeled collides in aqueous solutions has long been a problem. The authors have prepared several minimicroaggregated albumin colloids (mμAA) by heat denaturation of stannous-containing HSA solutions at pH 7.0, 7.5, and 8.5). The resulting colloids were labeled with Tc-99m and compared with Au-198 colloid and Tc-99m-antimony sulfide colloid (Tc-99m-Sb/sub 2/S3) by gel chromatography and gel electrophoresis. Tc-99mm-mμAA aggregated at pH 7.0 and the Au-198 colloid appeared in the external void volume of a BioRad A5.0 agarose column indicating an apparent MW of > 5 x 10/sup 6/ daltons. The pH7.5 Tc-99m-mμAA, migrated within the filtration range of the column as did a small fraction of Tc-99m-Sb/sub 2/S/sub 3/, suggesting that the MW is between 6 x 10/sup 4/ - 5 x 10/sup 6/ daltons. The Tc-99m-mμAA, aggregated at pH 8.5, had an apparent MW on gel filtration similar to that of untreated albumin, MW 6.6 x 10-/sup 4/ daltons. The mobilities of the colloids, on acrylamide disc gel electrophoresis, were consistent with the results on gel chromatography. The largest colloids, Au-198 colloid and pH 7.0 Tc-99m-mμAA, barely entered the separating gel; intermediate sized colloids, a small fraction of Tc-99m-Sb/sub 2/S/sub 3/ and pH 7.5 Tc-99m-mμAA migrated farther into the separating gel; while pH 8.5 Tc-99m-mμAA had mobility approaching that of untreated albumin. Lymphoscintigraphy studies using these colloids in animals showed the predicted, particle size-related differences in migration and clearance. The authors conclude that gel chromatography and gel electrophoresis are useful methods for estimating the apparent size of the colloidal particles

  14. Pleural mesothelioma in differential diagnostics of a tubercular exudative pleuritis

    Directory of Open Access Journals (Sweden)

    O.M. Raznatovskaya

    2017-02-01

    Full Text Available Background. Difficulties of differential diagnostics of exudative pleuritis due to pleura mesothelioma and such one of tubercular etiology can take a long time that is the reason of delayed well-timed and correct treatment order. Etiological diagnostics of exudative pleuritis has to be based on an integrated approach taking into account the data of clinical inspection of a patient, a laboratory research of pleural exudate, radial, instrumental, pathomorphological and surgical methods. The aim of our study is to establish the features of diagnosis of exudative pleuritis due to pleura mesothelioma by determining of informativeness and value of applied diagnostic methods for further use for differential diagnostics with exudative pleuritis of tubercular etiology on the cases of own clinical observations. Materials and methods. Four clinical cases of diagnostics of pleura mesothelioma in the patients with exudative pleuritis at Municipal Institution “Zaporizhzhia Regional Antituberculous Clinical Dispensary” were analyzed. Results. Four cases of pleura mesothelioma were diagnosed at Municipal Institution “Zaporizhzhia Regional Antituberculous Clinical Dispensary” within differential diagnostics of exudative pleuritis of obscure origin. In all cases the following similar features of pleura mesothelioma were observed: patients were male; patients complained about dyspnoea at exercise stress, thorax pain (on the side of mesothelioma localization, general weakness, periodic cough; the patients denied tuberculosis contact; the general blood test revealed only lymphopenia against the background of the accelerated ESR; micobacteria of tuberculosis were not revealed at all; steady accumulation of an exudate, despite its systematic evacuation; cytologic research of pleural liquid was characterized by a moderate turbidity, serous (serous and hemorrhagic character, with the specific weight of 1015–1016, rising of protein to 33–66 g/l, positive

  15. Sillica Gel-Amine from Geothermal Sludge

    Science.gov (United States)

    Muljani, S.; Pujiastuti, C.; Wicaksono, P.; Lutfianingrum, R.

    2018-01-01

    Silica Gel-Amine (SGA) has been made from geothermal sludge by grafting amine method. Sodium silicate solution is prepared by extracted geothermal sludge powder using sodium hidroxide solution then acidification in the range of pH 5 - 9 by using tartaric acid 1N. The grafting process uses 1 ml of ammonia solution and 10 ml of toluene at a rate of 0.1 ml min-1 accompanied by a reflux process. The amine grafting is done in two methods. The first method is grafting amine in silicate solution and the second method is grafting amine in washed gel. Product SGA was confirmed by FTIR, TGA-DTG and BET characterization. The results show that the pH affects the amount of amine that is grafted onto silica gel. Differences in grafting method affect the size of the pore and surface area. SGA product prepared by grafting washed gel at pH 8 have pore diameter of 12.06 nm, surface area of 173.44 m2g-1, and mass of decomposed amine compound 0.4 mg. In the presence of amine groups on the silica gel surface, these adsorbents may be able to selectively adsorb CO2 gas from natural gas.

  16. Structural and thermo-rheological analysis of solutions and gels of a β-lactoglobulin fraction isolated from bovine whey.

    Science.gov (United States)

    Estévez, Natalia; Fuciños, Pablo; Bargiela, Verónica; Pastrana, Lorenzo; Tovar, Clara Asunción; Luisa Rúa, M

    2016-05-01

    A β-Lactoglobulin fraction (r-βLg) was isolated from milk whey hydrolysates produced with cardosins from Cynara cardunculus. The impact of the technological process on the r-βLg structure and how in turn this determined its heat-induced gelation was investigated. Results were analysed taking pure β-Lg (p-βLg) as control sample. The process induced changes in the r-βLg native conformation causing exposure of hydrophobic groups, lower thermal stability and also, shorter thermal treatments needed to give rise to non-native and aggregated species. At pH 3.2, r-βLg and p-βLg solutions exhibited two gelation steps, with the advantage that r-βLg protein may form stable gels at lower temperature than p-βLg. At pH 7.2, a specific thermo-viscoelastic stability to 73 °C was found, which corresponded to the gel point in both protein solutions. The difference was that while for p-βLg solution in sol state δ45° (fluid-like). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Positron annihilation lifetime studies of sol-gel transition of carrageenan gels

    International Nuclear Information System (INIS)

    Wakabayashi, Y.; Ito, K.; Li, H.L.; Ujihara, Y.

    1996-01-01

    Positron annihilation lifetime measurement was applied to study the sol-gel transition of anionic polysaccharide aqueous solutions in terms of free-volume parameters the size, intensity, and size distribution of free volumes of the gelation of K-form κ-carrageenan solutions as a function of temperature. Slight variations of free volume size and intensity against temperature were observed near 295 K. The correlation of free-volume data with other physical properties vibrational spectra (IR and Raman), conductivity, SAXS, elastic measurement, differential scanning calorimetry were investigated to understand the mechanism of sol-gel transition of carrageenan. (author)

  18. Genetics Home Reference: familial exudative vitreoretinopathy

    Science.gov (United States)

    ... A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. ... Resources (2 links) GeneReview: Familial Exudative Vitreoretinopathy, Autosomal Dominant GeneReview: NDP-Related Retinopathies General Information from MedlinePlus ( ...

  19. Effect of intravitreal bevacizumab on diabetic macular edema with hard exudates

    Science.gov (United States)

    Jeon, Sohee; Lee, Won Ki

    2014-01-01

    Background We evaluated the efficacy of intravitreal bevacizumab on diabetic macular edema with subfoveal and perifoveal hard exudates. Materials and methods Eleven eyes (11 patients) exhibiting diabetic macular edema with subfoveal and perifoveal hard exudates were included in this prospective, nonrandomized interventional pilot study. All patients were treated with monthly scheduled intravitreal bevacizumab injections for 6 months. Changes in the Early Treatment Diabetic Retinopathy Study best corrected visual acuity, amount of hard exudates on fundus photography, and macular edema detected by central subfield thickness on spectral domain optical coherence tomography after six serial injections, were assessed. The amount of hard exudates at each visit was evaluated as pixels in fundus photography, using an Adobe Photoshop program. Results Ten of 11 patients completed follow-up. The mean Early Treatment Diabetic Retinopathy Study best corrected visual acuity was 59.9±5.7 letters (Snellen equivalent, 20/63) at baseline evaluation. The best corrected visual acuity exhibited no significant difference at month 6 compared with at baseline (57.9±6.0 letters or 20/70 at month 6; P=0.085). At month 6, mean central subfield thickness decreased from 370.4±56.5 to 334.6±65.0 μm (P=0.009). The mean amount of hard exudates increased from 4467.1±2736.1 to 6592.4±2498.3 pixels at month 6 (P=0.022). No serious adverse events occurred. Conclusion Continuous intravitreal bevacizumab was found to have no benefit in visual acuity and amount of hard exudates, despite the improvement of macular edema at 6 months. PMID:25143708

  20. The Effect of Testosterone Topical Solution in Hypogonadal Men With Suboptimal Response to a Topical Testosterone Gel.

    Science.gov (United States)

    Burns, Patrick R; Kim, Edward D; Ruff, Dustin D; Seftel, Allen D

    2018-05-01

    This study evaluated the effect of axillary administration of a 2% testosterone solution (Axiron ® ) in hypogonadal (HGN) men who had had a suboptimal response to treatment with a commercially available topical testosterone gel. HGN men averaging 57 years old, with a mean body mass index of 31.9 kg/m 2 and median baseline testosterone level (T-level) of 185.2 ng/dL, who had failed to reach normal T-levels with a topical testosterone gel (Androgel 1.62%, Androgel, Testim, or Fortesta) were treated with a 2% testosterone solution until T-levels reached a normal range (from ≥300 to ≤1,050 ng/dL) or for up to 9 weeks. Outcomes included the cumulative percentage of men with a serum T-level in the normal range during treatment with Axiron and improvement in symptoms of low energy level and low sexual drive. During the study, 95% of HGN men (72/78) attained a T-level in the normal range. The median T-level at endpoint was 495.7 ng/dL, a threefold increase over baseline, p levels within the first 2 weeks of treatment. In a post hoc analysis, all subjects with baseline body mass indexes >35 kg/m 2 ( n = 19) achieved T-levels in the normal range. Prior to treatment, over 61% of subjects (48/78) reported impairment in either energy level or sexual drive. After treatment (or testosterone normalization), energy level improved in 75% of subjects and sexual drive improved in 70%. Topical 2% testosterone solution is a safe and effective treatment for HGN men who have had a suboptimal response to previous treatment with topical testosterone gels.

  1. Multi-gel casting apparatus for vertical polyacrylamide gels with in-built solution flow system and liquid level detectors.

    Science.gov (United States)

    Maurye, Praveen; Basu, Arpita; Bandyopadhyay, Tapas Kumar; Biswas, Jayanta Kumar; Mohanty, Bimal Prasana

    2017-08-01

    PAGE is the most widely used technique for the separation and biochemical analysis of biomolecules. The ever growing field of proteomics and genomics necessitates the analysis of many proteins and nucleic acid samples to understand further about the structure and function of cells. Simultaneous analysis of multiple protein samples often requires casting of many PAGE gels. Several variants of multi-gel casting/electrophoresis apparatuses are frequently used in research laboratories. Requirement of supplementary gels to match the growing demand for analyzing additional protein samples sometimes become a cause of concern. Available apparatuses are not amenable to and therefore, not recommended for any modification to accommodate additional gel casting units other than what is prescribed by the manufacturer. A novel apparatus is described here for casting multiple PAGE gels comprising four detachable components that provide enhanced practicability and performance of the apparatus. This newly modified apparatus promises to be a reliable source for making multiple gels in less time without hassle. Synchronized functioning of unique components broaden the possibilities of developing inexpensive, safe, and time-saving multi-gel casting apparatus. This apparatus can be easily fabricated and modified to accommodate desired number of gel casting units. The estimated cost (∼$300) for fabrication of the main apparatus is very competitive and effortless assembly procedure can be completed within ∼30 min. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. AUTOMATIC RETINA EXUDATES SEGMENTATION WITHOUT A MANUALLY LABELLED TRAINING SET

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy which can be assessed by detecting exudates (a type of bright lesion) in fundus images. In this work, two new methods for the detection of exudates are presented which do not use a supervised learning step and therefore do not require ground-truthed lesion training sets which are time consuming to create, difficult to obtain, and prone to human error. We introduce a new dataset of fundus images from various ethnic groups and levels of DME which we have made publicly available. We evaluate our algorithm with this dataset and compare our results with two recent exudate segmentation algorithms. In all of our tests, our algorithms perform better or comparable with an order of magnitude reduction in computational time.

  3. Evaluation of lymphocytic exudative pleural effusion with pleural biopsy

    International Nuclear Information System (INIS)

    Khurram, M.; Jaffery, A.H.; Khar, Hamama-tul-Bushra; Malik, M.F.; Javed, S.; Burki, U.F.; Khan, B.A.; Ali, A.

    2002-01-01

    Objective: Evaluation of lymphocytic exudative pleural effusion by histopathological examination of pleural biopsy in patients with suspected tuberculous or malignant pleural effusion. Place and Duration of Study: The study was conducted at Pulmonology Department, Pakistan Institute of Medical Sciences, Islamabad and DHQ Teaching Hospital, Rawalpindi for two years 1999-2000. Subjects and Methods: A total of 120 patients with exudative pleural effusion underwent closed pleural biopsy with Abram's needle in standard way. Average 4 biopsy specimens were obtained in each patient which were examined histopathologically. Patients in whom a definite diagnosis was not possible were further investigated with repeat pleural biopsy, sputum examinations, bronchoscopy etc. Results definite histopathological diagnosis with pleural biopsy was possible in 59 (49.16% patients, including 13 diagnosed on repeat pleural biopsy. Two commonest diagnoses made were tuberculosis and adenocarcinoma, 64.40% and 13.55% respectively. Conclusion: Histopathological evaluation of pleural biopsy specimens can lead to diagnosis in 49.16% patients with exudative lymphocytic pleural effusion. (author)

  4. intra-species variation of the properties of gum exudates from Acacia

    African Journals Online (AJOL)

    a

    The results show that significant inter-species variation of the properties of the gum exudates from the two species exist, whereas only some parameters show significant intra-species variation. The specific optical rotations of the gum exudates have been found to vary from ---43.2o to ---52o for Acacia senegal var. senegal ...

  5. Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

    International Nuclear Information System (INIS)

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-01-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems.

  6. Rheological and micro-Raman time-series characterization of enzyme sol–gel solution toward morphological control of electrospun fibers

    Science.gov (United States)

    Oriero, Dennis A; Weakley, Andrew T; Aston, D Eric

    2012-01-01

    Rheological and micro-Raman time-series characterizations were used to investigate the chemical evolutionary changes of silica sol–gel mixtures for electrospinning fibers to immobilize an enzyme (tyrosinase). Results of dynamic rheological measurements agreed with the expected structural transitions associated with reacting sol–gel systems. The electrospinning sols exhibited shear-thinning behavior typical of a power law model. Ultrafine (200–300 nm diameter) fibers were produced at early and late times within the reaction window of approximately one hour from initial mixing of sol solutions with and without enzyme; diameter distributions of these fibers showed much smaller deviations than expected. The enzyme markedly increased magnitudes of both elastic and viscous moduli but had no significant impact on final fiber diameters, suggesting that the shear-thinning behavior of both sol–gel mixtures is dominant in the fiber elongation process. The time course and scale for the electrospinning batch fabrication show strong correlations between the magnitudes in rheological property changes over time and the chemical functional group evolution obtained from micro-Raman time-series analysis of the reacting sol–gel systems. PMID:27877486

  7. Increased root exudation of 14C-compounds by sorghum seedlings inoculated with nitrogen-fixing bacteria

    International Nuclear Information System (INIS)

    Lee, K.J.; Gaskins, M.H.

    1982-01-01

    Organic components leaked from Sorghum bicolor seedlings ('root exudates') were examined by recovering 14 C labelled compounds from root solutions of seedlings inoculated with Azospirillum brasilense, Azotobacter vinelandii or Klebsiella pneumoniae nif-. Up to 3.5% of the total 14 C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and Azotobacter increased the amounts of 14 C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria, the increase of 14 C in the solutions did not occur. Quantities of 14 C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with 14 CO 2 , about 15% of the total 14 C recovered within 48 hours exposure was found in soil leachates. (orig.)

  8. Solid phase extraction and metabolic profiling of exudates from living copepods

    DEFF Research Database (Denmark)

    Selander, Erik; Heuschele, Jan; Nylund, Göran M.

    2016-01-01

    describe the development of a closed loop solid phase extraction setup that allows for extraction of exuded metabolites from live copepods. We captured exudates from male and female Temora longicornis and analyzed the content with high resolution LC-MS. Chemometric methods revealed 87 compounds...... that solid phase extraction in combination with metabolic profiling of exudates is a useful tool to develop our understanding of the chemical interplay between pelagic organisms....... Copepodamide G, known to induce defensive responses in phytoplankton, was among the ten compounds of highest relative abundance in both male and female extracts. The presence of copepodamide G shows that the method can be used to capture and analyze chemical signals from living source organisms. We conclude...

  9. Dosimetric evaluation of spectrophotometric response of alanine gel solution for gamma, photons, electrons and thermal neutrons radiations; Avaliacao dosimetrica da resposta espectrofotometrica da solucao gel de alanina para radiacao gama, de fotons, de eletrons e de neutrons termicos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo

    2009-07-01

    Alanine Gel Dosimeter is a new gel material developed at IPEN that presents significant improvement on Alanine system developed by Costa. The DL-Alanine (C{sub 3}H{sub 7}NO{sub 2}) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. This work aims to analyse the main dosimetric characteristics this new gel material for future application to measure dose distribution. The performance of Alanine gel solution was evaluated to gamma, photons, electrons and thermal neutrons radiations using the spectrophotometry technique. According to the obtained results for the different studied radiation types, the reproducibility intra-batches and inter-batches is better than 4% and 5%, respectively. The dose response presents a linear behavior in the studied dose range. The response dependence as a function of dose rate and incident energy is better 2% and 3%, respectively. The lower detectable dose is 0.1 Gy. The obtained results indicate that the Alanine gel dosimeter presents good performance and can be useful as an alternative dosimeter in the radiotherapy area, using MRI technique for tridimensional dose distribution evaluation. (author)

  10. Zoospore exudates from Phytophthora nicotianae affect immune responses in Arabidopsis.

    Science.gov (United States)

    Kong, Ping; McDowell, John M; Hong, Chuanxue

    2017-01-01

    Zoospore exudates play important roles in promoting zoospore communication, homing and germination during plant infection by Phytophthora. However, it is not clear whether exudates affect plant immunity. Zoospore-free fluid (ZFF) and zoospores of P. nicotianae were investigated comparatively for effects on resistance of Arabidopsis thaliana Col-0 and mutants that affect signaling mediated by salicylic acid (SA) and jasmonic acid (JA): eds16 (enhanced disease susceptibility16), pad4 (phytoalexin deficient4), and npr1 (nonexpressor of pathogenesis-related genes1). Col-0 attracted more zoospores and had severe tissue damage when flooded with a zoospore suspension in ZFF. Mutants treated with ZFF alone developed disease symptoms similar to those inoculated with zoospores and requirements of EDS16 and PAD4 for plant responses to zoospores and the exudates was apparent. Zoospore and ZFFs also induced expression of the PR1 and PDF1.2 marker genes for defense regulated by SA and JA, respectively. However, ZFF affected more JA defense signaling, down regulating PR1 when SA signaling or synthesis is deficient, which may be responsible for Arabidopsis mutant plants more susceptible to infection by high concentration of P. nicotianae zoospores. These results suggest that zoospore exudates can function as virulence factors and inducers of plant immune responses during plant infection by Phytophthora.

  11. [Surgical treatment of patients with exudative otitis media].

    Science.gov (United States)

    Dmitriev, N S; Mileshina, N A

    2003-01-01

    The article concerns peculiarities of surgery for chronic exudative otitis media (CEOM). The significance of miringotomy, tympanostomy, tympanotomy and tympanoantrotomy is demonstrated. The experience of the authors in surgical treatment and postoperative management of CEOM is reviewed. Of primary importance is valid selection of patients for each operation and choice of ventilatory tubes depending on the disease stage. Incidence rate and causes of recurrences in respect to the patients' age are presented and the role of follow-up in prevention of CEOM recurrences is shown. Use of temporal bone computed tomography in CEOM is specified. Key words: exudative otitis media, tympanostomy, ventilation tubes, CT of the temporal bone.

  12. Diagnostic yield of pleural biopsy in exudative pleural effusion.

    Science.gov (United States)

    Devkota, K C; Chokhani, R; Gautam, S

    2014-09-01

    To know the diagnostic role of pleural biopsy in determining underlying etiological causes of exudative pleural effusion. A total of 47 patients, aged 16-104 years with mean age of 47.36 years, of either sex, with exudative pleural effusion underwent closed pleural biopsy with Abram's needle in standard way. Average 4-6 biopsy specimens were obtained from each patient, which were sent for histopathological examination. In this study, 47 cases of exudative pleural effusion were included, among them 26 (55.31%) cases were male and 21 (44.69%) were female with mean age 47.36 years. Cough was reported by 42 (89.36%) cases, expectoration 28 (59.57%), hemoptysis 3 (6.38%), breathlessness 27 (57.44%), wheezing 3 (6.38%), chest pain 38 (80.85%) and fever by 30 (63.82%) cases. Out of 47 cases, 28 (59.57%) cases had a positive yield, whereas in 19 (40.43%) cases the result was nonspecific inflammation. Out of 28 (59.57%) cases with positive yield 21 (44.68%) were found to have granulomatous inflammation and 10 (21.28%) cases were malignant. Among malignant pleural effusion, 4 cases were squamous cell carcinoma; 3 small cell carcinoma; 1 case adenocarcinoma and 1 case found to have mesothelioma. Tuberculosis and malignancy are the two most common causes of exudative pleural effusion in our set up. Pleural biopsy is a safe, simple and well validated diagnostic tool that helps us to differentiate between malignancy and tuberculosis.

  13. DESIGN AND DEVELOP A COMPUTER AIDED DESIGN FOR AUTOMATIC EXUDATES DETECTION FOR DIABETIC RETINOPATHY SCREENING

    Directory of Open Access Journals (Sweden)

    C. A. SATHIYAMOORTHY

    2016-04-01

    Full Text Available Diabetic Retinopathy is a severe and widely spread eye disease which can lead to blindness. One of the main symptoms for vision loss is Exudates and it could be prevented by applying an early screening process. In the Existing systems, a Fuzzy C-Means Clustering technique is used for detecting the exudates for analyzation. The main objective of this paper is, to improve the efficiency of the Exudates detection in diabetic retinopathy images. To do this, a three Stage – [TS] approach is introduced for detecting and extracting the exudates automatically from the retinal images for screening the Diabetic retinopathy. TS functions on the image in three levels such as Pre-processing the image, enhancing the image and detecting the Exudates accurately. After successful detection, the detected exudates are classified using GLCM method for finding the accuracy. The TS approach is experimented using MATLAB software and the performance evaluation can be proved by comparing the results with the existing approach’s result and with the hand-drawn ground truths images from the expert ophthalmologist.

  14. Fagopyrum esculentum Alters Its Root Exudation after Amaranthus retroflexus Recognition and Suppresses Weed Growth.

    Science.gov (United States)

    Gfeller, Aurélie; Glauser, Gaétan; Etter, Clément; Signarbieux, Constant; Wirth, Judith

    2018-01-01

    Weed control by crops through growth suppressive root exudates is a promising alternative to herbicides. Buckwheat ( Fagopyrum esculentum ) is known for its weed suppression and redroot pigweed ( Amaranthus retroflexus ) control is probably partly due to allelopathic root exudates. This work studies whether other weeds are also suppressed by buckwheat and if the presence of weeds is necessary to induce growth repression. Buckwheat and different weeds were co-cultivated in soil, separating roots by a mesh allowing to study effects due to diffusion. Buckwheat suppressed growth of pigweed, goosefoot and barnyard grass by 53, 42, and 77% respectively without physical root interactions, probably through allelopathic compounds. Root exudates were obtained from sand cultures of buckwheat (BK), pigweed (P), and a buckwheat/pigweed mixed culture (BK-P). BK-P root exudates inhibited pigweed root growth by 49%. Characterization of root exudates by UHPLC-HRMS and principal component analysis revealed that BK and BK-P had a different metabolic profile suggesting that buckwheat changes its root exudation in the presence of pigweed indicating heterospecific recognition. Among the 15 different markers, which were more abundant in BK-P, tryptophan was identified and four others were tentatively identified. Our findings might contribute to the selection of crops with weed suppressive effects.

  15. Actuator device utilizing a conductive polymer gel

    Science.gov (United States)

    Chinn, Douglas A.; Irvin, David J.

    2004-02-03

    A valve actuator based on a conductive polymer gel is disclosed. A nonconductive housing is provided having two separate chambers separated by a porous frit. The conductive polymer is held in one chamber and an electrolyte solution, used as a source of charged ions, is held in the second chamber. The ends of the housing a sealed with a flexible elastomer. The polymer gel is further provide with electrodes with which to apply an electrical potential across the gel in order to initiate an oxidation reaction which in turn drives anions across the porous frit and into the polymer gel, swelling the volume of the gel and simultaneously contracting the volume of the electrolyte solution. Because the two end chambers are sealed the flexible elastomer expands or contracts with the chamber volume change. By manipulating the potential across the gel the motion of the elastomer can be controlled to act as a "gate" to open or close a fluid channel and thereby control flow through that channel.

  16. A NOVEL GEL ELECTROLYTE FOR VALVE-REGULATED LEAD ACID BATTERY

    Directory of Open Access Journals (Sweden)

    Metin GENÇTEN

    2017-03-01

    Full Text Available A novel gel electrolyte system used in lead-acid batteries was investigated in this work. The gel systems were prepared by addition different amount of Al2O3, TiO2 and B2O3 into the gelled system consisting of 6 wt% fumed silica and 30 wt% sulfuric acid solution. The anodic peak currents and peak redox capacities of the gel electrolytes were characterized by cyclic voltammetric method. They decreased by the time B2O3 and Al2O3 were used as additives in fumed silica based gel electrolyte system. However, these values increased by the adding 3.0 wt% of TiO2. The solution and charge transfer resistances of the gel electrolytes were investigated by electrochemical impedance spectroscopy. While the solution resistances were lower in gel systems having different amount additives than pure fumed silica based gel, the charge transfer resistance was the lowest in gel electrolytes consisting fumed silica and fumed silica-TiO2. The battery performances were studied by obtaining discharge curves of prepared gel electrolytes. The performance of gelled systems were higher than that of non-gelled electrolyte at room temperature. The mixture of fumed silica-TiO2 was suggested an alternative gel formulation for gel VRLA batteries.

  17. Comparison of systemic absorption between ofloxacin ophthalmic in situ gels and ofloxacin conventional ophthalmic solutions administration to rabbit eyes by HPLC-MS/MS.

    Science.gov (United States)

    Li, Jiawei; Zhao, Hainan; Okeke, Chukwunweike Ikechukwu; Li, Lin; Liu, Zhidong; Yin, Zhongpeng; Zhuang, Pengwei; Sun, Jingtong; Wu, Tao; Wang, Meng; Li, Nan; Pi, Jiaxin; Zhang, Qian; Zhang, Rui; Ma, Li; Pang, Xiaochen; Liu, Zhanbiao; Zhang, Li; Fan, Lili

    2013-06-25

    In recent years, many pharmaceutical scientists have focused on developing the in situ gel-forming systems to overcome the poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions due to rapid pre-corneal elimination of the drug. The present work was to compare the systemic absorptions of ophthalmic ofloxacin in situ gel with the conventional ofloxacin eye drop after topical instillation to rabbit eyes by HPLC-MS/MS method and also determine the relative contribution of the nasal and the conjunctival mucosae to systemic ofloxacin absorption following topical instillation. The systemic AUC, Cmax, Tmax and Ke for ophthalmic in situ gel and ophthalmic solution after ocular instillation were 202.63±118.85 and 202.25±57.74 ng mL(-1) h, 54.22±28.31 and 48.4±25.97 ng mL(-1), 1.08±0.20 and 1.25±0.88 h, 0.0576±0.0207 and 0.0388±0.0248, respectively. And the values for the ratios of the AUC of anterior chamber of rabbit eye to blood plasma, AUCac/AUCpl, for ofloxacin conventional eye drop and in situ gel were 0.25 and 0.52, respectively. Statistic results showed that there was no significant difference in systemic absorption between the test groups and the reference groups (P>0.05) as both formulations have an AUCsa/AUCpl of 0.35. Therefore, the ophthalmic in situ gel may not decrease the drugs systemic absorption when administered in an equivalent dose as ophthalmic solutions into the rabbit eyes. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Chemical composition and functional properties of gum exudates from the trunk of the almond tree (Prunus dulcis).

    Science.gov (United States)

    Mahfoudhi, N; Chouaibi, M; Donsì, F; Ferrari, G; Hamdi, S

    2012-06-01

    The physicochemical components and functional properties of the gum exudates from the trunk of the almond tree (Prunus dulcis) have been investigated, along with the emulsification and foaming properties. The gum exudates are composed on dry weight basis by 2.45% of proteins, 0.85% of fats and 92.36% of carbohydrates. The latter consist of arabinose, xylitol, galactose and uronic acid (46.8 : 10.9 : 35.5 : 6.0 mass ratio) with traces of rhamnose, mannose and glucose. Moreover, gum exudates are rich in minerals, such as sodium, potassium, magnesium, calcium and iron. The emulsifying capacity was studied for a 20% w/w olive oil in water emulsion as a function of gum concentration (from 3% to 12% w/w in the aqueous phase) as well as pH levels (from 3.0 to 10.0). The most stable and homogeneous emulsion was prepared with an 8% w/w aqueous almond gum solution at a pH between 5.0 and 8.0. In particular, for the same formulation, the emulsion processed by high pressure homogenization (5 passes at 200 MPa) resulted to be extremely stable under accelerated ageing, exhibiting no significant change in droplet size distribution for 14 days at 55 °C. All the tested systems exhibited an extremely low foaming capacity.

  19. Zoospore exudates from Phytophthora nicotianae affect immune responses in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ping Kong

    Full Text Available Zoospore exudates play important roles in promoting zoospore communication, homing and germination during plant infection by Phytophthora. However, it is not clear whether exudates affect plant immunity. Zoospore-free fluid (ZFF and zoospores of P. nicotianae were investigated comparatively for effects on resistance of Arabidopsis thaliana Col-0 and mutants that affect signaling mediated by salicylic acid (SA and jasmonic acid (JA: eds16 (enhanced disease susceptibility16, pad4 (phytoalexin deficient4, and npr1 (nonexpressor of pathogenesis-related genes1. Col-0 attracted more zoospores and had severe tissue damage when flooded with a zoospore suspension in ZFF. Mutants treated with ZFF alone developed disease symptoms similar to those inoculated with zoospores and requirements of EDS16 and PAD4 for plant responses to zoospores and the exudates was apparent. Zoospore and ZFFs also induced expression of the PR1 and PDF1.2 marker genes for defense regulated by SA and JA, respectively. However, ZFF affected more JA defense signaling, down regulating PR1 when SA signaling or synthesis is deficient, which may be responsible for Arabidopsis mutant plants more susceptible to infection by high concentration of P. nicotianae zoospores. These results suggest that zoospore exudates can function as virulence factors and inducers of plant immune responses during plant infection by Phytophthora.

  20. Increased root exudation of /sup 14/C-compounds by sorghum seedlings inoculated with nitrogen-fixing bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.J. (Institute of Forest Genetics, Suweon (Republic of Korea)); Gaskins, M.H. (Florida Univ., Gainesville (USA). Dept. of Agriculture)

    1982-01-01

    Organic components leaked from Sorghum bicolor seedlings ('root exudates') were examined by recovering /sup 14/C labelled compounds from root solutions of seedlings inoculated with Azospirillum brasilense, Azotobacter vinelandii or Klebsiella pneumoniae nif-. Up to 3.5% of the total /sup 14/C recovered from shoots, roots, and nutrient solutions was found in the root solutions. Inoculation with Azospirillum and Azotobacter increased the amounts of /sup 14/C and decreased the amounts of carbohydrates in the root solutions. When sucrose was added as a carbon source for the bacteria, the increase of /sup 14/C in the solutions did not occur. Quantities of /sup 14/C found in the root solutions were proportional to amounts of mineral nitrogen supplied to the plants. Bacterial growth also was proportional to nitrogen levels. When sorghum plants were grown in soil and labelled with /sup 14/CO/sub 2/, about 15% of the total /sup 14/C recovered within 48 hours exposure was found in soil leachates.

  1. Effect of Sugar Maple Root Exudate on Seedlings of Northern Conifer Species

    Science.gov (United States)

    Carl H. Tubbs

    1976-01-01

    It has been shows that a root exudate of sugar maple reduces the growth of yellow birch. A laboratory test indicated that the growth of northern conifers is also reduced in sugar maple root exudate. Allelopathy may play an important role in survival of species on sites where sugar maple is abundant.

  2. Hard Retinal exudates and visual loss due to papilledema

    International Nuclear Information System (INIS)

    Rush, J.A.

    1982-01-01

    Bilateral papilledema developed in a patient with a cystic, grade 3 astrocytoma of the right frontal lobe. Despite successful neurosurgical treatment, 60 Co radiotherapy, and oral corticosteroid therapy, progressive visual loss occurred. At examination one year later, visual activity was 20/200 and 20/70, and extensive lipid exudates in the peripapillary retina and central macula of each eye were noted. Retinal lipid exudates rarely complicate the course of surviving patients who had papilledema from intracranial tumor; physicians involved in the multispecialty care of such patients should be aware of the possible ocular residuals of persistent papilledema in an otherwise successfully treated patient

  3. Aloe vera phenomenon: a review of the properties and modern uses of the leaf parenchyma gel

    Energy Technology Data Exchange (ETDEWEB)

    Grindlay, D.; Reynolds, T.

    1986-06-01

    The mucilaginous gel from the parenchymatous cells in the leaf pulp of Aloe vera has been used since early times for a host of curative purposes. This gel should be distinguished clearly from the bitter yellow exudate originating from the bundle sheath cells, which is used for its purgative effects. Aloe vera gel has come to play a prominent role as a contemporary folk remedy, and numerous optimistic, and in some cases extravagant, claims have been made for its medicinal properties. Modern clinical use of the gel began in the 1930s, with reports of successful treatment of X-ray and radium burns, which led to further experimental studies using laboratory animals in the following decades. The reports of these experiments and the numerous favourable case histories did not give conclusive evidence, since although positive results were usually described, much of the work suffered from poor experimental design and insufficiently large test samples. In addition some conflicting or inconsistent results were obtained. With the recent resurgence of interest in Aloe vera gel, however, new experimental work has indicated the possibility of distinct physiological effects. Chemical analysis has shown the gel to contain various carbohydrate polymers, notably either glucomannans or pectic acid, along with a range of other organic and inorganic components. Although many physiological properties of the gel have been described, there is no certain correlation between these and the identified gel components. 154 references.

  4. Disentangling the rhizosphere effect on nitrate reducers and denitrifiers: insight into the role of root exudates.

    Science.gov (United States)

    Henry, S; Texier, S; Hallet, S; Bru, D; Dambreville, C; Chèneby, D; Bizouard, F; Germon, J C; Philippot, L

    2008-11-01

    To determine to which extent root-derived carbon contributes to the effects of plants on nitrate reducers and denitrifiers, four solutions containing different proportions of sugar, organic acids and amino acids mimicking maize root exudates were added daily to soil microcosms at a concentration of 150 microg C g(-1) of soil. Water-amended soils were used as controls. After 1 month, the size and structure of the nitrate reducer and denitrifier communities were analysed using the narG and napA, and the nirK, nirS and nosZ genes as molecular markers respectively. Addition of artificial root exudates (ARE) did not strongly affect the structure or the density of nitrate reducer and denitrifier communities whereas potential nitrate reductase and denitrification activities were stimulated by the addition of root exudates. An effect of ARE composition was also observed on N(2)O production with an N(2)O:(N(2)O + N(2)) ratio of 0.3 in microcosms amended with ARE containing 80% of sugar and of 1 in microcosms amended with ARE containing 40% of sugar. Our study indicated that ARE stimulated nitrate reduction or denitrification activity with increases in the range of those observed with the whole plant. Furthermore, we demonstrated that the composition of the ARE affected the nature of the end-product of denitrification and could thus have a putative impact on greenhouse gas emissions.

  5. Effect of co-solute and gelation temperature on milk protein and gum tragacanth interaction in acidified gels.

    Science.gov (United States)

    Hatami, Masoud; Nejatian, Mohammad; Mohammadifar, Mohammad Amin

    2012-05-01

    The aim of this study was to investigate the role of process conditions and system composition on the acid-induced gelation of a mixture of milk protein and gum tragacanth. This was studied by determining the effects of co-solute (lactose) addition (3, 5 and 7%) and gelation temperature (25, 37 and 45°C) on the mixture's rheological properties and microstructure using a combination of techniques including small-deformation rheology and scanning electron microscopy. The presence of lactose played an important role in the microstructure formation of gels but did not change most rheological properties. The microstructure of gels formed in the presence of lactose was coarser and more particulate, but less interconnected; this can be explained by lactose's role in improving protein aggregation. Gels prepared at a lower temperature had a high structure strength, as indicated by their high storage modulus, τ(f) and G(f) values. Low gelation temperature also caused a more branched and homogenous microstructure. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. A multiscale optimization approach to detect exudates in the macula.

    Science.gov (United States)

    Agurto, Carla; Murray, Victor; Yu, Honggang; Wigdahl, Jeffrey; Pattichis, Marios; Nemeth, Sheila; Barriga, E Simon; Soliz, Peter

    2014-07-01

    Pathologies that occur on or near the fovea, such as clinically significant macular edema (CSME), represent high risk for vision loss. The presence of exudates, lipid residues of serous leakage from damaged capillaries, has been associated with CSME, in particular if they are located one optic disc-diameter away from the fovea. In this paper, we present an automatic system to detect exudates in the macula. Our approach uses optimal thresholding of instantaneous amplitude (IA) components that are extracted from multiple frequency scales to generate candidate exudate regions. For each candidate region, we extract color, shape, and texture features that are used for classification. Classification is performed using partial least squares (PLS). We tested the performance of the system on two different databases of 652 and 400 images. The system achieved an area under the receiver operator characteristic curve (AUC) of 0.96 for the combination of both databases and an AUC of 0.97 for each of them when they were evaluated independently.

  7. Thermotropic phase transition in aqueous polymer solutions and gels as studied by .sup.1./sup.H NMR methods

    Czech Academy of Sciences Publication Activity Database

    Spěváček, Jiří; Hanyková, L.; Starovoytova, L.; Ilavský, Michal

    2002-01-01

    Roč. 2, č. 3 (2002), s. 36-43 ISSN 1335-8243 R&D Projects: GA AV ČR IAA4050209 Grant - others:GA UK(XC) 164/2001B Institutional research plan: CEZ:AV0Z4050913 Keywords : thermotropic phase transition * collapse * D 2 O solutions and gels Subject RIV: CD - Macromolecular Chemistry

  8. Yield stress determination of a physical gel

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2013-01-01

    Pluronic F127 solutions form gels in water with high elastic moduli. Pluronic gels can, however, only withstand small deformations and stresses. Different steady shear and oscillatory methods traditionally used to determine yield stress values are compared. The results show that the yield stresses...... values of these gels depend on test type and measurement time, and no absolute yield stress value can be determined for these physical gels....

  9. Silica Sol-Gel Entrapment of the Enzyme Chloro peroxidase

    International Nuclear Information System (INIS)

    Le, T.; Chan, S.; Ebaid, B.; Sommerhalter, M.

    2015-01-01

    The enzyme chloro peroxidase (CPO) was immobilized in silica sol-gel beads prepared from tetramethoxysilane. The average pore diameter of the silica host structure (∼3 nm) was smaller than the globular CPO diameter (∼6 nm) and the enzyme remained entrapped after sol-gel maturation. The catalytic performance of the entrapped enzyme was assessed via the pyrogallol peroxidation reaction. Sol-gel beads loaded with 4 μg CPO per mL sol solution reached 9-12% relative activity compared to free CPO in solution. Enzyme kinetic analysis revealed a decrease in K_cat but no changes in K_M or K_I . Product release or enzyme damage might thus limit catalytic performance. Yet circular dichroism and visible absorption spectra of transparent CPO sol-gel sheets did not indicate enzyme damage. Activity decline due to methanol exposure was shown to be reversible in solution. To improve catalytic performance the sol-gel protocol was modified. The incorporation of 5, 20, or 40% methyltrimethoxysilane resulted in more brittle sol-gel beads but the catalytic performance increased to 14% relative to free CPO in solution. The use of more acidic casting buffers (ph 4.5 or 5.5 instead of 6.5) resulted in a more porous silica host reaching up to 18% relative activity

  10. Methylobacterium-plant interaction genes regulated by plant exudate and quorum sensing molecules

    Directory of Open Access Journals (Sweden)

    Manuella Nóbrega Dourado

    2013-12-01

    Full Text Available Bacteria from the genus Methylobacterium interact symbiotically (endophytically and epiphytically with different plant species. These interactions can promote plant growth or induce systemic resistance, increasing plant fitness. The plant colonization is guided by molecular communication between bacteria-bacteria and bacteria-plants, where the bacteria recognize specific exuded compounds by other bacteria (e.g. homoserine molecules and/or by the plant roots (e.g. flavonoids, ethanol and methanol, respectively. In this context, the aim of this study was to evaluate the effect of quorum sensing molecules (N-acyl-homoserine lactones and plant exudates (including ethanol in the expression of a series of bacterial genes involved in Methylobacterium-plant interaction. The selected genes are related to bacterial metabolism (mxaF, adaptation to stressful environment (crtI, phoU and sss, to interactions with plant metabolism compounds (acdS and pathogenicity (patatin and phoU. Under in vitro conditions, our results showed the differential expression of some important genes related to metabolism, stress and pathogenesis, thereby AHL molecules up-regulate all tested genes, except phoU, while plant exudates induce only mxaF gene expression. In the presence of plant exudates there is a lower bacterial density (due the endophytic and epiphytic colonization, which produce less AHL, leading to down regulation of genes when compared to the control. Therefore, bacterial density, more than plant exudate, influences the expression of genes related to plant-bacteria interaction.

  11. The role of haemorrhage and exudate detection in automated grading of diabetic retinopathy.

    Science.gov (United States)

    Fleming, Alan D; Goatman, Keith A; Philip, Sam; Williams, Graeme J; Prescott, Gordon J; Scotland, Graham S; McNamee, Paul; Leese, Graham P; Wykes, William N; Sharp, Peter F; Olson, John A

    2010-06-01

    Automated grading has the potential to improve the efficiency of diabetic retinopathy screening services. While disease/no disease grading can be performed using only microaneurysm detection and image-quality assessment, automated recognition of other types of lesions may be advantageous. This study investigated whether inclusion of automated recognition of exudates and haemorrhages improves the detection of observable/referable diabetic retinopathy. Images from 1253 patients with observable/referable retinopathy and 6333 patients with non-referable retinopathy were obtained from three grading centres. All images were reference-graded, and automated disease/no disease assessments were made based on microaneurysm detection and combined microaneurysm, exudate and haemorrhage detection. Introduction of algorithms for exudates and haemorrhages resulted in a statistically significant increase in the sensitivity for detection of observable/referable retinopathy from 94.9% (95% CI 93.5 to 96.0) to 96.6% (95.4 to 97.4) without affecting manual grading workload. Automated detection of exudates and haemorrhages improved the detection of observable/referable retinopathy.

  12. Nanocrystalline (U0.5Ce0.5)O2±x solid solutions through citrate gel-combustion

    Science.gov (United States)

    Maji, D.; Ananthasivan, K.; Venkata Krishnan, R.; Balakrishnan, S.; Amirthapandian, S.; Joseph, Kitheri; Dasgupta, Arup

    2018-04-01

    Nanocrystalline powders of (U0.5Ce0.5)O2±x solid solutions were synthesized in bulk (100-200 g) through the citrate gel combustion. The fuel (citric acid) to oxidant (nitrate) mole ratio (R) was varied from 0.1 to 1.0. Two independent lots of the products obtained through the gel-combustion were calcined at 973 K in air and in a mixture of argon containing 8% H2 respectively. All these powders were characterized for their bulk density, X-ray crystallite size, specific surface area, size distribution of the particles, porosity as well as residual carbon. The morphology and microstructures of these powders were studied by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. Nanocrystalline single phase fluorite solid solutions having a typical crystallite size of about (7-15 nm) were obtained. These powders were highly porous comprising cuboidal flaky agglomerates. The combustion mixture with an 'R' value of 0.25 was found to undergo volume combustion and was found to yield a product that was distinctly different. The systematic investigation on synthesis and characterization of nanocrystalline UCeO2 is reported for the first time.

  13. A multi-step system for screening and localization of hard exudates in retinal images

    Science.gov (United States)

    Bopardikar, Ajit S.; Bhola, Vishal; Raghavendra, B. S.; Narayanan, Rangavittal

    2012-03-01

    The number of people being affected by Diabetes mellitus worldwide is increasing at an alarming rate. Monitoring of the diabetic condition and its effects on the human body are therefore of great importance. Of particular interest is diabetic retinopathy (DR) which is a result of prolonged, unchecked diabetes and affects the visual system. DR is a leading cause of blindness throughout the world. At any point of time 25 - 44% of people with diabetes are afflicted by DR. Automation of the screening and monitoring process for DR is therefore essential for efficient utilization of healthcare resources and optimizing treatment of the affected individuals. Such automation would use retinal images and detect the presence of specific artifacts such as hard exudates, hemorrhages and soft exudates (that may appear in the image) to gauge the severity of DR. In this paper, we focus on the detection of hard exudates. We propose a two step system that consists of a screening step that classifies retinal images as normal or abnormal based on the presence of hard exudates and a detection stage that localizes these artifacts in an abnormal retinal image. The proposed screening step automatically detects the presence of hard exudates with a high sensitivity and positive predictive value (PPV ). The detection/localization step uses a k-means based clustering approach to localize hard exudates in the retinal image. Suitable feature vectors are chosen based on their ability to isolate hard exudates while minimizing false detections. The algorithm was tested on a benchmark dataset (DIARETDB1) and was seen to provide a superior performance compared to existing methods. The two-step process described in this paper can be embedded in a tele-ophthalmology system to aid with speedy detection and diagnosis of the severity of DR.

  14. Dosimetry for computed tomography using Fricke gel dosimetry and magnetic resonance imaging; Dosimetria em tomografia computadorizada empregando dosimetro Fricke gel e a tecnica de imageamento por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Capeleti, Felipe Favaro; Campos, Leticia L., E-mail: felipe@gmpbrasil.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-04-15

    In this work it was determined a new method for the determination of absorbed doses in Computed Tomography (CT) examinations using Fricke gel dosimetry developed at IPEN. Absorbed doses were determined by different methods of analysis, such as optical absorption spectrometry, ionization chambers and magnetic resonance imaging. Lower limit of sensitivity of the Fricke gel solution, the solution repeatability signal Fricke gel and CT equipment, detection sensitivity, among other tests were performed. Different equipment of computed tomography with multiple detectors were used. The Fricke gel solution showed better repeatability than ±5.5% using the technique of optical absorption spectrophotometry and computed tomography equipment showed repeatability better than ±0.2%. The Fricke gel solution features an easy and relatively quick preparation, but it is necessary to be careful not to contaminate and lose the solution. With the results, it was confirmed the application of this type of dosimetry for computed tomography equipment. (author)

  15. Prognostic value of pro-inflammatory cytokine and pro-angiogenesis factor in differentiating malignant from benign exudative effusion.

    Science.gov (United States)

    Elhefny, Radwa Ahmed; Shaban, Marwa Moawad; Shaker, Olfat Gamil

    2017-01-01

    The precise mechanism of pathogenesis in exudation of effusions is uncertain. Released factors in inflammation and malignancy of pleura are related to incremented permeability of the micro-pleural vessels. Angiopoietins (Ang) take part in development of angiogenesis and pleural inflammation. Interleukin-8 (IL-8) influences proliferation and tumor angiogenesis and it is expressed in cancer. The aims of this study were to investigate the relationship between inflammation, angiogenesis and etiologies of exudative effusions, and to evaluate the diagnostic value in differentiating malignant from benign. The study includes 49 pleural fluid (PF) samples. Ang-2 and IL-8 in PF and serum were estimated. Ten patients were transudative and 39 patients were exudative fluid, subdivided into 16 benign and 23 malignant effusion. Ang-2 and IL-8 either fluid level or ratio were in significantly high in exudative more than in transudative fluid (P = 0.002). Ang-2 and IL-8 in PF were in high level than in serum of exudative and transudative. Ang-2 fluid level and ratio were significantly high in benign exudative effusion (P = 0.01, P = 0.05, respectively), while IL-8 level was significantly high in malignant exudative effusion (P = 0.04). Cut-off points for PF Ang-2 and IL-8 in differentiating malignant from benign exudative were 15.67 ng/mL, 325.54 pg/mL, respectively. Our results support the evidence that angiogenesis and inflammatory pathways are linked, and that inflammation and vascular permeability of pleura constitutes the pathogenic basis of the majority of exudative effusion. © 2015 John Wiley & Sons Ltd.

  16. Root Exudation in Common Ragweed (Ambrosia Artemisiifolia L.)

    Czech Academy of Sciences Publication Activity Database

    Figala, J.; Hohnová, Barbora; Moravcová, Dana; Lvončík, S.; Lojková, L.; Formánek, P.

    2016-01-01

    Roč. 5, č. 5 (2016), s. 1034-1037 ISSN 2278-1862 Institutional support: RVO:68081715 Keywords : ambrosia artemisiifolia * root exudates * amino acids * aliphatic organic acids * allelopathy Subject RIV: CB - Analytical Chemistry, Separation

  17. Surface grafted chitosan gels. Part II. Gel formation and characterization

    DEFF Research Database (Denmark)

    Liu, Chao; Thormann, Esben; Claesson, Per M.

    2014-01-01

    Responsive biomaterial hydrogels attract significant attention due to their biocompatibility and degradability. In order to make chitosan based gels, we first graft one layer of chitosan to silica, and then build a chitosan/poly(acrylic acid) multilayer using the layer-by-layer approach. After...... cross-linking the chitosan present in the polyelectrolyte multilayer, poly(acrylic acid) is partly removed by exposing the multilayer structure to a concentrated carbonate buffer solution at a high pH, leaving a surface-grafted cross-linked gel. Chemical cross-linking enhances the gel stability against...... detachment and decomposition. The chemical reaction between gluteraldehyde, the cross-linking agent, and chitosan was followed in situ using total internal reflection Raman (TIRR) spectroscopy, which provided a molecular insight into the complex reaction mechanism, as well as the means to quantify the cross...

  18. Optical sensing of HCl with phenol red doped sol-gels

    International Nuclear Information System (INIS)

    Wang Enju; Chow, Kwok-Fan; Wang Wenqun; Wong, Crystal; Yee, Cynthia; Persad, Alvin; Mann, Jonathan; Bocarsly, Andrew

    2005-01-01

    A dye doped sol-gel for the sensing of hydrochloric acid in solution and/or gaseous phase is described. The sol-gel is obtained by acidic hydrolysis of tetraethoxysilane (TEOS) and phenyltriethoxysilane (Ph-TriEOS) in the presence of phenol red (PR) and further spin-coating onto glass slides. The sensitive response is based on an increase of the absorption band at 510 nm of phenol red entrapped in the sol-gel casting when exposed to HCl solution or gas, due to protonation of the dye. The detection limit of the sol-gel response to moisturized gaseous HCl is below 12 ppm, and its response to HCl in solution falls in the range of 0.01-6 M. The sol-gel coating has a response time of less than 40 s in steady-state, and life-time of more than a year. Weak acids such as acetic acid, benzoic acid, salicylate acid, citrate acid, and carbonic acid do not interfere the response. The responses in acid solutions are completely reversible. In the gaseous phase, response of HCl appears to be moisture sensitive

  19. Optical sensing of HCl with phenol red doped sol-gels

    Energy Technology Data Exchange (ETDEWEB)

    Wang Enju [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States)]. E-mail: wange@stjohns.edu; Chow, Kwok-Fan [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Wang Wenqun [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Wong, Crystal [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Yee, Cynthia [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Persad, Alvin [Department of Chemistry, St. John' s University, 8000 Utopia Parkway, Jamaica, NY 11439 (United States); Mann, Jonathan [Department of Chemistry, Princeton University, Princeton, NJ 08540 (United States); Bocarsly, Andrew [Department of Chemistry, Princeton University, Princeton, NJ 08540 (United States)

    2005-04-08

    A dye doped sol-gel for the sensing of hydrochloric acid in solution and/or gaseous phase is described. The sol-gel is obtained by acidic hydrolysis of tetraethoxysilane (TEOS) and phenyltriethoxysilane (Ph-TriEOS) in the presence of phenol red (PR) and further spin-coating onto glass slides. The sensitive response is based on an increase of the absorption band at 510 nm of phenol red entrapped in the sol-gel casting when exposed to HCl solution or gas, due to protonation of the dye. The detection limit of the sol-gel response to moisturized gaseous HCl is below 12 ppm, and its response to HCl in solution falls in the range of 0.01-6 M. The sol-gel coating has a response time of less than 40 s in steady-state, and life-time of more than a year. Weak acids such as acetic acid, benzoic acid, salicylate acid, citrate acid, and carbonic acid do not interfere the response. The responses in acid solutions are completely reversible. In the gaseous phase, response of HCl appears to be moisture sensitive.

  20. Naturally-assisted metal phytoextraction by Brassica carinata: Role ofroot exudates

    Energy Technology Data Exchange (ETDEWEB)

    Quartacci, Mike F., E-mail: mfquart@agr.unipi.i [Dipartimento di Chimica e Biotecnologie Agrarie, Universita di Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Irtelli, Barbara [Dipartimento di Chimica e Biotecnologie Agrarie, Universita di Pisa, Via del Borghetto 80, 56124 Pisa (Italy); Gonnelli, Cristina; Gabbrielli, Roberto [Dipartimento di Biologia Vegetale, Sezione di Ecologia e Fisiologia Vegetale, Universita di Firenze, Via Micheli 1, 50121 Firenze (Italy); Navari-Izzo, Flavia [Dipartimento di Chimica e Biotecnologie Agrarie, Universita di Pisa, Via del Borghetto 80, 56124 Pisa (Italy)

    2009-10-15

    Due to relatively high chelant dosages and potential environmental risks it is necessary to explore different approaches in the remediation of metal-contaminated soils. The present study focussed on the removal of metals (As, Cd, Cu, Pb and Zn) from a multiple metal-contaminated soil by growing Brassica carinata plants in succession to spontaneous metallicolous populations of Pinus pinaster, Plantago lanceolata and Silene paradoxa. The results showed that the growth of the metallicolous populations increased the extractable metal levels in the soil, which resulted in a higher accumulation of metals in the above-ground parts of B. carinata. Root exudates of the three metallicolous species were analysed to elucidate their possible role in the enhanced metal availability. The presence of metals stimulated the exudation of organic and phenolic acids as well as flavonoids. It was suggested that root exudates played an important role in solubilising metals in soil and in favouring their uptake by roots. - Phytoextraction of metals is enhanced in Brassica carinata grown in succession to metallicolous populations of spontaneous species.

  1. Naturally-assisted metal phytoextraction by Brassica carinata: Role ofroot exudates

    International Nuclear Information System (INIS)

    Quartacci, Mike F.; Irtelli, Barbara; Gonnelli, Cristina; Gabbrielli, Roberto; Navari-Izzo, Flavia

    2009-01-01

    Due to relatively high chelant dosages and potential environmental risks it is necessary to explore different approaches in the remediation of metal-contaminated soils. The present study focussed on the removal of metals (As, Cd, Cu, Pb and Zn) from a multiple metal-contaminated soil by growing Brassica carinata plants in succession to spontaneous metallicolous populations of Pinus pinaster, Plantago lanceolata and Silene paradoxa. The results showed that the growth of the metallicolous populations increased the extractable metal levels in the soil, which resulted in a higher accumulation of metals in the above-ground parts of B. carinata. Root exudates of the three metallicolous species were analysed to elucidate their possible role in the enhanced metal availability. The presence of metals stimulated the exudation of organic and phenolic acids as well as flavonoids. It was suggested that root exudates played an important role in solubilising metals in soil and in favouring their uptake by roots. - Phytoextraction of metals is enhanced in Brassica carinata grown in succession to metallicolous populations of spontaneous species.

  2. Recognition of root exudates by seeds of broomrape (Orobanche and Phelipanche) species

    Science.gov (United States)

    Fernández-Aparicio, M.; Flores, F.; Rubiales, D.

    2009-01-01

    Background and Aims The long co-existence of broomrapes and their hosts within the same environment has culminated in a strong adaptation and effective parasitism. As a first step of specialization in the parasitic process, seed receptors of parasitic plant species vary in their ability to recognize compounds released by their hosts. This work aims to investigate potential patterns for the reception requirements needed to activate germination within Orobanche and Phelipanche species. Methods Induction of the germination of seeds of nine Orobanche and Pheliphanche species by root exudates of 41 plant species was studied and subjected to biplot multivariate analysis. Key Results A high level of specialization in root exudate recognition was found in Orobanche densiflora, O. gracilis and O. hederae, which germinated almost exclusively in contact with root exudates from the plants they infect in nature. At the opposite extreme, Phelipanche aegyptiaca, P. ramosa and O. minor were highly generalist, germinating when in contact with the root exudates of most plant species. Orobanche crenata, O. cumana and O. foetida showed intermediate behaviour. Conclusions A universal germination stimulant for all broomrape species has not being identified to date. The synthetic stimulant GR24 is active against most of the weedy broomrape species, but fails with the non-weedy species tested in this study and with the very recent weedy species O. foetida. In addition, germination behaviour of broomrape species depends on the crop plant tested. Weedy broomrapes with a broad host spectrum respond better to the different exudates released by a wide range of crops and wild species than do non-weedy broomrapes, which have a narrow host spectrum and are more restricted to their host range. Root exudates of many plant species were active in stimulating germination of seeds of Orobanche and Phelipanche species for which they are not described as hosts, representing interesting examples of

  3. EXPERIENCE OF TREATMENT WITH FENSPIRIDE IN CHILDREN WITH CHRONIC EXUDATIVE OTITIS MEDIA AFTER TYMPANOSTOMY

    Directory of Open Access Journals (Sweden)

    L.A. Toropova

    2009-01-01

    Full Text Available The trial presents the analysis of factors predisposing to exudative otitis media development in 709 children, needing regular audiologist’s check-up. It was shown that dominating risk factor of auditory tube’s function disorders is hypertrophy of palatine tonsil (it was detected in 69% of children. Besides, doctors from children’s out-patient clinics often use conservative treatment in children with chronic exudative otitis media. Analysis of data obtained at the time of treatment of 180 hospitalized children under the age 1–17 years old with exudative otitis media showed that combination of tympanostomy with fenspiride (Erespal allows achieving of more significant decrease (1.3 times low audibility threshold of different oscillations than in children from control (treated without fenspiride.Key words: children, exudative otitis media, timpanostomy, fenspiride.(Voprosy sovremennoi pediatrii — Current Pediatrics. 2009;8(4:102-105

  4. Root exudates from grafted-root watermelon showed a certain contribution in inhibiting Fusarium oxysporum f. sp. niveum.

    Directory of Open Access Journals (Sweden)

    Ning Ling

    Full Text Available Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON, but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants.

  5. Chemical Analysis of the Resinous Exudate Isolated from Heliotropium taltalense and Evaluation of the Antioxidant Activity of the Phenolics Components and the Resin in Homogeneous and Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    René Torres

    2009-06-01

    Full Text Available H. taltalense (Phil. Johnst. (Heliotropiaceae is an endemic species of the northern coast of Chile that produces a resinous exudate that covers its foliar surface and stems. Its chemical composition was analyzed for the first time, and two aromatic geranyl derivatives: filifolinol and filifolinyl senecionate and three flavonoids – naringenin, 3-O-methylgalangin and 7-O-methyleriodictiol – were isolated. The antioxidant activity of the flavonoids and the resinous exudates was carried out by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH bleaching effect in ethanolic solution and in sodium dodecyl sulfate (SDS micelles. The influence of the reaction medium was analyzed. The initial velocity reactions for the pure compounds and for the extract were higher in SDS media than in ethanolic solution. The velocity of reaction observed was interpreted in terms of the reaction medium environment in the micelle.

  6. Chemical analysis of the resinous exudate isolated from Heliotropium taltalense and evaluation of the antioxidant activity of the phenolics components and the resin in homogeneous and heterogeneous systems.

    Science.gov (United States)

    Modak, Brenda; Rojas, Macarena; Torres, René

    2009-06-02

    H. taltalense (Phil.) Johnst. (Heliotropiaceae) is an endemic species of the northern coast of Chile that produces a resinous exudate that covers its foliar surface and stems. Its chemical composition was analyzed for the first time, and two aromatic geranyl derivatives: filifolinol and filifolinyl senecionate and three flavonoids - naringenin, 3-O-methylgalangin and 7-O-methyleriodictiol - were isolated. The antioxidant activity of the flavonoids and the resinous exudates was carried out by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching effect in ethanolic solution and in sodium dodecyl sulfate (SDS) micelles. The influence of the reaction medium was analyzed. The initial velocity reactions for the pure compounds and for the extract were higher in SDS media than in ethanolic solution. The velocity of reaction observed was interpreted in terms of the reaction medium environment in the micelle.

  7. Functional coatings: the sol-gel approach

    International Nuclear Information System (INIS)

    Belleville, Ph.

    2010-01-01

    CEA's sol-gel laboratory is specialized in the development of innovative sol-gel optical coatings and has extended its application field to membrane materials and coatings for energy conversion, to electric coatings for microelectronics devices and to thin films for gas sensing. This article describes, by way of examples, the laboratory's research on sol-gel functional coatings, including nano-material synthesis, organic-inorganic hybrid-based solution preparation as well as deposition process development and prototyping. (author)

  8. Affects N fertilization intensity and composition of root exudation from two plant species differing in their exploitation strategy?

    Science.gov (United States)

    Kotas, Petr; Kastovska, Eva

    2017-04-01

    The rhizosphere represents one of the most important hotspots of microbial activity in soil. As such, it controls soil element cycling and significantly contributes to important ecosystem processes like C and N sequestration. The close plant-microbe-soil interactions in the rhizosphere are mediated by the input of labile exudates into the surroundings of plant roots. Thus microbial performance is constrained by the intensity and composition of root exudation. However, it is poorly understood how closely root exudation corresponds with the plant metabolome and how it is related to plant traits and changing environmental conditions. To fill this gap, we determined the composition of the root metabolic pool and root exudates in two plant species differing in their exploitation type (conservative Carex acuta versus competitive Glyceria maxima) grown for two months in controlled conditions and treated weekly by two levels of foliar N fertilization. Based on previous studies, we knew that Glyceria has, compared to Carex, a lower tissue C:N ratio, higher photosynthetic rate, higher allocation belowground and also larger investment to exudation. Prior to extraction, the roots were cleaned by water and immediately frozen in liquid N2. The root exudates were collected from carefully cleaned roots of living plants encased in glass vials with water and subsequently lyophilised. Both sample types were silylated and analysed for their metabolic profiles using GC-MS/MS. Our results revealed that the metabolite content in root tissue (DW basis) of Glyceria was on average lower compared to Carex, but increased with fertilization, while the root tissue of Carex was characterized by significantly higher metabolite content in the low intensity fertilization treatment compared to both the control and high N fertilization intensity. In contrast, the amount of exuded compounds was much higher in Glyceria compared to Carex in the control plants, but decreased for Glyceria and increased

  9. Some physico-chemical properties of Prunus armeniaca L. gum exudates.

    Science.gov (United States)

    Fathi, Morteza; Mohebbi, Mohebbat; Koocheki, Arash

    2016-01-01

    The objectives of this paper were to investigate some physicochemical properties of Prunus armeniaca L. gum exudates (PAGE). PAGE had, on average, 66.89% carbohydrate, 10.47% uronic acids, 6.9% moisture (w.b.), 2.91% protein, 4% ash and 1.59% fat. PAGE was composed of monosaccharides including l-arabinose, d-galactose, xylose, mannose and rhamnose in molar percentages of 41.52%, 23.72%, 17.82%, 14.40% and 2.54%, respectively. Elemental analysis showed that PAGE had high values of nutrients. FTIR analysis demonstrated the presence of carboxyl, hydroxyl and methyl groups and glycoside bonds. The weight average molecular weight, number average molecular weight and polydispersity index were found to be approximately 5.69 × 10(5)g/mol, 4.33 g/mol and 1.31, respectively. Rheological measurement of PAGE solutions as a function of concentration (8, 10 and 12% (w/w)) and temperature (10, 20, 30 and 40°C) demonstrated that the gum solutions had a non Newtonian shear thinning behaviour. Intrinsic viscosity for PAGE in deionized water was 3.438 dl/g based on Kramer equation. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Stress differentially impacts reserve pools and root exudation: implications for ecosystem functioning and carbon balance

    Science.gov (United States)

    Landhäusser, Simon; Karst, Justine; Wiley, Erin; Gaster, Jacob

    2016-04-01

    Environmental stress can influence carbon assimilation and the accumulation and distribution of carbon between growth, reserves, and exudation; however, it is unclear how these processes vary by different stress types. Partitioning of carbon to growth and reserves in plants might also vary between different organs. Roots reserves are of particular interest as they link the plant with the soil carbon cycle through exudation. Simple models of diffusion across concentration gradients predict the more C reserves in roots, the more C should be exuded from roots. However, the mechanisms underlying the accumulation and loss of C from roots may differ depending on the stress experienced by the plants. In a controlled study we tested whether different types of stresses (shade, cold soil, and drought) have differential effects on the distribution, abundance, and form (sugar vs. starch) of carbohydrates in seedlings, and whether these changes alone could explain differences in root exudation between stress types. Non-structural carbohydrate (NSC) concentration and pool sizes varied by stress type and between organs. Mass-specific C exudation increased with fine root sugar concentration; however, stress type affected exudation independently of reserve concentration. Seedlings exposed to cold soils exuded the most C on a per root mass basis followed by shade and drought. Through 13C labeling, we also found that depending on the stress type, aspen seedlings may be less able to control the loss of C to the soil compared with unstressed seedlings, resulting in more C leaked to the rhizosphere. The loss of C beyond that predicted by simple concentration gradients might have important implications for ecosystem functioning and carbon balance. If stressed plants lose proportionally more carbon to the soil, existing interactions between plants and soils may decouple under stress, and may include unexpected C fluxes between trees, soils and the atmosphere with a changing climate.

  11. Risk factors for exudative age-related macular degeneration in a large French case-control study.

    Science.gov (United States)

    Zerbib, Jennyfer; Delcourt, Cécile; Puche, Nathalie; Querques, Giuseppe; Cohen, Salomon Yves; Sahel, José; Korobelnik, Jean-François; Le Goff, Mélanie; Souied, Eric H

    2014-06-01

    The purpose of the CAP (Creteil AMD PHRC-funded) Study was to analyze risk factors of exudative age-related macular degeneration (AMD) in a large French case-control population. One thousand and twenty-four patients with exudative AMD and 275 controls were recruited. Information about lifestyle, medical history, and dietary intake were collected. Associations of risk factors were estimated using logistic regression. After multivariate adjustment, CFH Y402H and ARMS2 A69S polymorphisms were associated with very high risk for exudative AMD (OR = 6.21 and OR = 11.7, respectively, p cooking oils rich in omega 3 fatty acids was significantly associated with a reduced risk of exudative AMD (OR = 0.55, 95 % CI: 0.36-0.84, p = 0.006), as well as a high consumption of fruits (OR = 0.60, 95 % CI: 0.37-0.98, p = 0.04), but not the consumption of fish, vegetables or oils rich in omega 6. High waist circumference was associated with increased risk for exudative AMD (OR = 2.53, p cooking oils harboring a beneficial omega-3 fatty acid profile.

  12. [Erespal effectiveness in exudative otitis media].

    Science.gov (United States)

    Levina, Iu V; Luchikhin, L A; Krasiuk, A A

    2003-01-01

    Standard conservative treatment of exudative otitis media (EOM) was performed in 82 patients, but 44 of them received adjuvant fenspiride (erespal) in a dose 80 mg per os 3 times a day for 10 days. Dynamic pure tone audiometry, tympanometry and subjective response demonstrated higher treatment efficiency in the erespal group. Therefore, it is recommended to include erespal in combined conventional therapy of EOM.

  13. Potential of Root Exudates from Wetland Plants and Their Potential Role for Denitrification and Allelopathic Interactions

    DEFF Research Database (Denmark)

    Zhai, Xu

    Root exudates from wetland plants have both positive and negative interactions among microbe, plants and ecosystems. Wetland species releasing organic carbon into the rhizosphere for providing energy to denitrifying bacteria fuel denitrification for removal nitrogen in subsurface flow constructed...... wetlands. Furthermore, environmental factors such as temperature and light-regime affect the photosynthetic carbon fixation, which continuously influence the compositions and quantity of root exudates released into rhizosphere. Conversely, root exudates from invasive species might contain some phytotoxic...... chemicals to suppress the growth of native species. Phragmites australis is recognized as the most invasive species in wetland ecosystems in North America, and allelopathy has been reported to be involved in the invasion success of the introduced exotic P. australis. The composition of the root exudates may...

  14. Chemical composition of essential oil of exudates of Dryobalanops ...

    African Journals Online (AJOL)

    Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia, ... Gas chromatography-mass spectrometry (GC-MS) was used to characterize the ... Conclusion: Essential oil from the exudates of D. aromatica contains ..... industries.

  15. [Effects of wheat root exudates on cucumber growth and soil fungal community structure].

    Science.gov (United States)

    Wu, Feng-Zhi; Li, Min; Cao, Peng; Ma, Ya-Fei; Wang, Li-Li

    2014-10-01

    With wheat as the donor plant and cucumber as the receptor plant, this study investigated the effects of root exudates from wheat cultivars with different allelopathic potentials (positive or negative) and companion cropping with wheat on soil fungal community structure by PCR-DGGE method and cucumber growth. Results showed that the wheat root exudates with positive allelopathic potential increased height and stem diameter of cucumber seedlings significantly, compared to the control seedlings (W) after 6 days and 12 days treatment, respectively. Also, wheat root exudates with both positive and negative allelopathic potential increased the seedling height of cucumber significantly after 18 days treatment. The wheat root exudates with different allelopathic potentials decreased the band number, Shannon and evenness indices of soil fungal community significantly in cucumber seedling rhizosphere, and those in the soil with the control seedlings (W) were also significantly higher than that in the control soil without seedlings (Wn) after 6 days treatment. The band number, Shannon and evenness indices in all the treatments were significantly higher than those in the control soil without seedlings (Wn) after 18 days treatment. Companion cropping with negative allelopathic potential wheat decreased the Shannon and evenness indices of soil fungi community significantly in the cucumber seedling rhizosphere, suggesting the wheat root exudates and companion cropping with wheat changed soil fungal community structure in the cucumber seedling rhizosphere. The results of DGGE map and the principal component analysis showed that companion cropping with wheat cultivars with different allelopathic potentials changed soil fungal community structure in cucumber seedling rhizosphere.

  16. Do microbial exudates control EH electrode measurements?

    Science.gov (United States)

    Markelova, E.; Parsons, C. T.; Smeaton, C. M.; Van Cappellen, P.

    2017-12-01

    Redox electrodes are widely used as simple, inexpensive monitoring devices to rapidly measure redox potentials (EH) of waterlogged soils, sediments, and aquifers. While a variety of physicochemical and biogeochemical factors have been involved to explain measured EH values, the role of microorganisms remains comparatively understudied and uncertain. Besides catalyzing many inorganic redox reactions (e.g., nitrate reduction), microorganisms produce a variety of redox-active organic compounds (e.g., NAD+/NADH, GSSG/2GSH, FAD/FADH2), which can be released into the surrounding environment via active secretion, passive diffusion, or cell lysis. To isolate different microbial effects on EH measurements, we performed batch experiments using S. oneidensis MR-I as a model heterotrophic microorganism and flavins as example microbial exudates [1]. We monitored EH and pH along with flavin production (fluorescence measurements) during dissimilatory nitrate reduction to ammonium (DNRA). Dissolved flavins increased to 0.2 mM (riboflavin equivalent) under anoxic conditions during complete consumption of 1 mM nitrate by DNRA at pH 7.4 and 30 °C over 80 hours. The observed redox cascade from +255 to -250 mV did not follow the EH predicted for the reduction of NO3- to NO2- and NO2- to NH4+ by the Nernst equation. However, a set of separate abiotic experiments on the photoreduction of synthetic flavins (LMC, RF, FMN, and FAD, Sigma Aldrich) under the same conditions indicated that measured EH values are buffered at +270 ± 20 mV and -230 ± 50 mV when oxidized and reduced flavin species dominate, respectively. Moreover, based on the temporal changes in EH, we speculate that NO3- reduction by S. oneidensis consumes reduced flavins (i.e., NO3- accepts electrons from reduced flavins) and generates oxidized flavins, thus buffering EH at +255 mV. By contrast, NO2- reduction to NH4+ is independent of flavin speciation, which leads to the accumulation of reduced flavins in the solution and

  17. The meaning of living with malodorous exuding ulcers.

    Science.gov (United States)

    Lindahl, Elisabeth; Norberg, Astrid; Söderberg, Anna

    2007-03-01

    This study illuminates the meaning of living with malodorous, exuding ulcers. Difficulties for patients with chronic ulcers and the ulcers' impact on patients' daily life are described in the literature. Suffering and consolation are also addressed in the literature as important issues in nursing care. The first author interviewed seven women and two men, aged 41-95, with various diagnoses. We interpreted the transcribed interviews using a phenomenological hermeneutic method. Two processes were identified: 'being struck down'- themes: feeling dirty, being trapped, losing confidence, losing hope, becoming frustrated and protecting oneself; and 'finding consolation'- themes: experiencing kinship, encountering genuineness and gaining control. The meaning of living with malodorous and exuding ulcers can be understood as being trapped in a debilitating process that slowly strikes one down. There is a longing for purity and wholeness and for one's life to improve. When people with malodorous, exuding ulcers encounter genuineness and feel loved, regarded and respected as fully human despite their ulcers, they feel purified. The contaminated body no longer contaminates their self-image and self-esteem and they feel restored and fully human again. Only when they feel fully human can they regain control and see life beyond their ulcers. Although nurses cannot make ulcers or smell disappear, they can contribute significantly to improve the patients' life. Finding consolation makes patients feel purified despite their contaminated body. This study points to the importance of seeing the human being beyond the ulcer and considering not only the body but the whole person.

  18. Reproducibility and signal response linearity of Alanine gel dosimeter

    International Nuclear Information System (INIS)

    Silva, Cleber Feijo Silva; Campos, Leticia Lucente

    2008-01-01

    Gel Dosimetry has been studied mainly for medical applications, because it presents signal response in the dose range used in radiotherapy treatments and it can be applied for three dimensional dosimetry. Alanine gel dosimeter is a new gel material developed at IPEN that presents significant improvement on previous alanine systems developed by Costa (1994). The DL-Alanine (C 3 H 7 NO 2 ) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. These ferric ions concentration can be measured by spectrophotometry technique. This work aims to study the reproducibility of the alanine gel solutions and the signal response as a function of gamma radiation dose, considering that these two properties are very important for characterizing and standardizing any dosimeter. (author)

  19. Decreased levels of matrix metalloproteinase-2 in root-canal exudates during root canal treatment.

    Science.gov (United States)

    Pattamapun, Kassara; Handagoon, Sira; Sastraruji, Thanapat; Gutmann, James L; Pavasant, Prasit; Krisanaprakornkit, Suttichai

    2017-10-01

    To determine the matrix metalloproteinase-2 (MMP-2) levels in root-canal exudates from teeth undergoing root-canal treatment. The root-canal exudates from six teeth with normal pulp and periradicular tissues that required intentional root canal treatment for prosthodontic reasons and from twelve teeth with pulp necrosis and asymptomatic apical periodontitis (AAP) were sampled with paper points for bacterial culture and aspirated for the detection of proMMP-2 and active MMP-2 by gelatin zymography and the quantification of MMP-2 levels by ELISA. By gelatin zymography, both proMMP-2 and active MMP-2 were detected in the first collection of root-canal exudates from teeth with pulp necrosis and AAP, but not from teeth with normal pulp, and their levels gradually decreased and disappeared at the last collection. Consistently, ELISA demonstrated a significant decrease in MMP-2 levels in the root-canal exudates of teeth with pulp necrosis and AAP following root canal procedures (papical lesions, similar to the clinical application of MMP-8 as a biomarker. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Metabolomes of Potato Root Exudates: Compounds That Stimulate Resting Spore Germination of the Soil-Borne Pathogen Spongospora subterranea.

    Science.gov (United States)

    Balendres, Mark A; Nichols, David S; Tegg, Robert S; Wilson, Calum R

    2016-10-12

    Root exudation has importance in soil chemical ecology influencing rhizosphere microbiota. Prior studies reported root exudates from host and nonhost plants stimulated resting spore germination of Spongospora subterranea, the powdery scab pathogen of potato, but the identities of stimulatory compounds were unknown. This study showed that potato root exudates stimulated S. subterranea resting spore germination, releasing more zoospores at an earlier time than the control. We detected 24 low molecular weight organic compounds within potato root exudates and identified specific amino acids, sugars, organic acids, and other compounds that were stimulatory to S. subterranea resting spore germination. Given that several stimulatory compounds are commonly found in exudates of diverse plant species, we support observations of nonhost-specific stimulation. We provide knowledge of S. subterranea resting spore biology and chemical ecology that may be useful in formulating new disease management strategies.

  1. Preparation of zirconium molybdate gel for 99mTc gel generator

    International Nuclear Information System (INIS)

    Aliludin, Z.; Ohkubo, Masatake; Kushita, Kouhei

    1988-09-01

    Zirconium molybdate gel has excellent characteristics for use as column matrix material of 99m Tc generators. In this work, zirconium molybdate gels were prepared under different conditions; pH's of molybdate solutions from 2.5 to 7.0, Mo:Zr molar ratios from 0.7:1.0 to 1.3:1.0, drying temperatures from an ambient temperature to 200 deg C, and drying times from 1 h to 25 h. Contents of water, nitrate, molybdenum and zirconium were measured to examine the fundamental conditions in gel preparation. The Mo:Zr molar ratio was 1.0:1.0 for the most of gels obtained. A 99m Tc generator was prepared with an amorphous zirconium molybdate containing a tracer level of 99 Mo as column matrix material. Elution of 99m Tc was rapid and the average elution efficiency was 90 % for 6 ml elutions. Contents of radionuclidic impurities, Zr and Mo in the eluates, were low enough to meet the pharmacopoeia requirements for human use. (author)

  2. Silica scintillating materials prepared by sol-gel methods

    International Nuclear Information System (INIS)

    Werst, D.W.; Sauer, M.C. Jr.; Cromack, K.R.; Lin, Y.; Tartakovsky, E.A.; Trifunac, A.D.

    1993-01-01

    Silica was investigated as a rad-hard alternative to organic polymer hosts for organic scintillators. Silica sol-gels were prepared by hydrolysis of tetramethoxysilane in alcohol solutions. organic dyes were incorporated into the gels by dissolving in methanol at the sol stage of gel formation. The silica sol-gel matrix is very rad-hard. The radiation stability of silica scintillators prepared by this method is dye-limited. Transient radioluminescence was measured following excitation with 30 ps pulses of 20 MeV electrons

  3. Low Light Availability Alters Root Exudation and Reduces Putative Beneficial Microorganisms in Seagrass Roots

    Directory of Open Access Journals (Sweden)

    Belinda C. Martin

    2018-01-01

    Full Text Available Seagrass roots host a diverse microbiome that is critical for plant growth and health. Composition of microbial communities can be regulated in part by root exudates, but the specifics of these interactions in seagrass rhizospheres are still largely unknown. As light availability controls primary productivity, reduced light may impact root exudation and consequently the composition of the root microbiome. Hence, we analyzed the influence of light availability on root exudation and community structure of the root microbiome of three co-occurring seagrass species, Halophila ovalis, Halodule uninervis and Cymodocea serrulata. Plants were grown under four light treatments in mesocosms for 2 weeks; control (100% surface irradiance (SI, medium (40% SI, low (20% SI and fluctuating light (10 days 20% and 4 days 100%. 16S rDNA amplicon sequencing revealed that microbial diversity, composition and predicted function were strongly influenced by the presence of seagrass roots, such that root microbiomes were unique to each seagrass species. Reduced light availability altered seagrass root exudation, as characterized using fluorescence spectroscopy, and altered the composition of seagrass root microbiomes with a reduction in abundance of potentially beneficial microorganisms. Overall, this study highlights the potential for above-ground light reduction to invoke a cascade of changes from alterations in root exudation to a reduction in putative beneficial microorganisms and, ultimately, confirms the importance of the seagrass root environment – a critical, but often overlooked space.

  4. Outcome of ultrasound-guided small-bore catheter drainage in exudative pleural effusions.

    Science.gov (United States)

    Kiranantawat, Nantaka; Sungsiri, Jitpreedee; Geater, Sarayut L

    2014-05-01

    To evaluate the outcome and safety of ultrasound-guided percutaneous catheter drainage of exudative pleural effusion. The present study was a retrospective analysis of 412 pleural effusions from 373 patients that underwent ultrasound-guided small-bore catheter drainage in exudative pleural effusions between 2004 and 2009. The two most common causes for drainage were parapneumonic effusion or empyema (52.2%) and malignant effusion (30.3%), while the remains were trauma, iatrogenic, and others. Overall clinical success rate was 76.5%. The success rate was lower among malignant pleural effusion (p = 0.003). Causes of effusion were the only independent predictors related to success. Only five (1.2%) patients developed complication during the procedure. Seventy-five of 412 effusions (15.8%) developed complication during the period of drainage; the majority were drain blockage (9%) and accidental dislodgment (4.1%). Ultrasound-guided small-bore catheter drainage was a safe and efficient procedure for exudative pleural effusions.

  5. Molecular responses in root-associative rhizospheric bacteria to variations in plant exudates

    Science.gov (United States)

    Abdoun, Hamid; McMillan, Mary; Pereg, Lily

    2015-04-01

    Plant exudates are a major factor in the interface of plant-soil-microbe interactions and it is well documented that the microbial community structure in the rhizosphere is largely influenced by the particular exudates excreted by various plants. Azospirillum brasilense is a plant growth promoting rhizobacterium that is known to interact with a large number of plants, including important food crops. The regulatory gene flcA has an important role in this interaction as it controls morphological differentiation of the bacterium that is essential for attachment to root surfaces. Being a response regulatory gene, flcA mediates the response of the bacterial cell to signals from the surrounding rhizosphere. This makes this regulatory gene a good candidate for analysis of the response of bacteria to rhizospheric alterations, in this case, variations in root exudates. We will report on our studies on the response of Azospirillum, an ecologically, scientifically and agriculturally important bacterial genus, to variations in the rhizosphere.

  6. Anti-Atherogenicity Following Administration of Exudate from Aloe ...

    African Journals Online (AJOL)

    Anti-Atherogenicity Following Administration of Exudate from Aloe barbadensis Leaves in Diabetic Rats. HU Nwanjo, GO Oze. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers ...

  7. Efficacy of a new tan doped sol-gel sorbent for uptake of zinc

    International Nuclear Information System (INIS)

    Khan, A.; Ahmed, S.; Riaz, M.; Mahmood, F.; Younas Khokhar, M.

    2003-01-01

    A TAN (1-(2-Thiazolylazo)-2-naphthol) doped sol gel silica sorbent (reddish colour, porous, stable, hard, non-swelling) were prepared and investigated for the removal of Zn (II) from aqueous solutions. The kinetics, adsorption isotherm, equilibration time and pH effect on the removal were studied from non competitive aqueous solution to optimize the conditions to be utilized on a large scale. Fast equilibration was observed and adsorption equilibria were reached within 30 minutes. Adsorption of zinc ions on the blank (un-doped) sol gel was found negligible. The maximum adsorption of Zn (II) ions onto the TAN doped sol-gel from single solutions were 2.33 mg/g (0.035 mmol/g). TAN doped sol gel can be regenerated through washing with a solution of 0.1 M HCl solution. The maximum regeneration value was as high as 99.0%. The TAN-doped sol gel silica is suitable at least for four adsorption-desorption cycles without experiencing considerable loss of adsorption capacity. The uptake route and the nature of the Zn-TAN complex have been discussed. (orig.)

  8. Root Exudation: The Ecological Driver of Hydrocarbon Rhizoremediation

    Directory of Open Access Journals (Sweden)

    Fanny Rohrbacher

    2016-03-01

    Full Text Available Rhizoremediation is a bioremediation technique whereby microbial degradation of organic contaminants occurs in the rhizosphere. It is considered to be an effective and affordable “green technology” for remediating soils contaminated with petroleum hydrocarbons. Root exudation of a wide variety of compounds (organic, amino and fatty acids, carbohydrates, vitamins, nucleotides, phenolic compounds, polysaccharides and proteins provide better nutrient uptake for the rhizosphere microbiome. It is thought to be one of the predominant drivers of microbial communities in the rhizosphere and is therefore a potential key factor behind enhanced hydrocarbon biodegradation. Many of the genes responsible for bacterial adaptation in contaminated soil and the plant rhizosphere are carried by conjugative plasmids and transferred among bacteria. Because root exudates can stimulate gene transfer, conjugation in the rhizosphere is higher than in bulk soil. A better understanding of these phenomena could thus inform the development of techniques to manipulate the rhizosphere microbiome in ways that improve hydrocarbon bioremediation.

  9. Chromium toxicity tolerance of Solanum nigrum L. and Parthenium hysterophorus L. plants with reference to ion pattern, antioxidation activity and root exudation.

    Science.gov (United States)

    UdDin, Islam; Bano, Asghari; Masood, Sajid

    2015-03-01

    Chromium (Cr), being a highly toxic metal, adversely affects the mineral uptake and metabolic processes in plants when present in excess. The current study was aimed at investigating the Cr accumulation in various plant tissues and its relation to the antioxidation activity and root exudation. Plants were grown in soil spiked with different concentrations of Cr for three weeks in pots and analysed for different growth, antioxidants and ion attributes. Furthermore, plants treated with different concentrations of Cr in pots were shifted to rhizobox-like system for 48h and organic acids were monitored in the mucilage dissolved from the plant root surface, mirroring rhizospheric solution. The results revealed that the Cr application at 1mM increased the shoot fresh and dry weight and root dry weight of Solanum nigrum, whereas the opposite was observed for Parthenium hysterophorus when compared with lower levels of Cr (0.5mM) or control treatment. In both plant species, Cr and Cl concentrations were increased while Ca, Mg and K concentrations in root, shoot and root exudates were decreased with increasing levels of Cr. Higher levels of Cr treatments enhanced the activities of SOD, POD and proline content in leaves of S. nigrum, whereas lower levels of Cr treatment were found to have stimulatory effects in P. hysterophorus. P. hysterophorus exhibited highest exudation of organic acid contents. With increasing levels of Cr treatments, citric acid concentration in root exudates increased by 35% and 44% in S. nigrum, whereas 20% and 76% in P. hysterophorus. Cr toxicity was responsible for the shoot growth reduction of S. nigrum and P. hysterophorus, however, shoot growth response was different at different levels of applied Cr. Consequently, Cr stress negatively altered the plant physiology and biochemistry. However, the enhanced antioxidant production, Cl uptake and root exudation are the physiological and biochemical indicators for the plant adaptations in biotic systems

  10. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Low temperature bonding of silicon wafers was achieved using sol-gel technology. The initial sol-gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The thickness and density of the sol-gel coating were characterised using ellipsometry. The corresponding bonded specimens were investigated using attenuated total reflectance Fourier transformed infrared spectroscopy to monitor their chemical composition, infrared imaging to control bond integrity, and cross-sectional transmission electron microscopy to study their microstructure. Their interfacial fracture energy was measured using microindentation. An optimum water-to-alkoxide molar ratio of 10 and hydrolysis water at pH = 2 were found. Such conditions led to relatively dense films (> 90%), resulting in bonds with a fracture energy of 3.5 J/m 2 , significantly higher than those obtained using classical hydrophilic bonding (typically 1.5-2.5 J/m 2 ). Ageing of the coating solution was found to decrease the bond strength

  11. DMSP synthesis and exudation in phytoplankton : a modeling approach

    NARCIS (Netherlands)

    Laroche, D; Vézina, A.F; Levasseur, M; Gosselin, M; Stefels, J.; Keller, M.D; Matrai, P.A; Kwint, R.L J

    1999-01-01

    In the marine environment, phytoplankton are the fundamental producers of dimethylsulfoniopropionate (DMSP), the precursor of the climatically active gas dimethylsulfide (DMS). DMSP is released by exudation, cell autolysis, and zooplankton grazing during phytoplankton blooms. In this study, we

  12. Exudate detection in color retinal images for mass screening of diabetic retinopathy.

    Science.gov (United States)

    Zhang, Xiwei; Thibault, Guillaume; Decencière, Etienne; Marcotegui, Beatriz; Laÿ, Bruno; Danno, Ronan; Cazuguel, Guy; Quellec, Gwénolé; Lamard, Mathieu; Massin, Pascale; Chabouis, Agnès; Victor, Zeynep; Erginay, Ali

    2014-10-01

    The automatic detection of exudates in color eye fundus images is an important task in applications such as diabetic retinopathy screening. The presented work has been undertaken in the framework of the TeleOphta project, whose main objective is to automatically detect normal exams in a tele-ophthalmology network, thus reducing the burden on the readers. A new clinical database, e-ophtha EX, containing precisely manually contoured exudates, is introduced. As opposed to previously available databases, e-ophtha EX is very heterogeneous. It contains images gathered within the OPHDIAT telemedicine network for diabetic retinopathy screening. Image definition, quality, as well as patients condition or the retinograph used for the acquisition, for example, are subject to important changes between different examinations. The proposed exudate detection method has been designed for this complex situation. We propose new preprocessing methods, which perform not only normalization and denoising tasks, but also detect reflections and artifacts in the image. A new candidates segmentation method, based on mathematical morphology, is proposed. These candidates are characterized using classical features, but also novel contextual features. Finally, a random forest algorithm is used to detect the exudates among the candidates. The method has been validated on the e-ophtha EX database, obtaining an AUC of 0.95. It has been also validated on other databases, obtaining an AUC between 0.93 and 0.95, outperforming state-of-the-art methods. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Current and future possibilities of sol-gel process

    International Nuclear Information System (INIS)

    Sakka, Sumio

    2004-01-01

    The sol-gel method is characterized by the low temperature processing. Since this method starts from solutions, the product is essentially nanomaterials. So far, various kinds of microstructures, including dense, porous, hybrid, amorphous and crystalline microstructures have been realized. Accordingly, sol-gel materials cover a wide range of functions, such as optical, electronic, mechanical, chemical and bio-functions. Future perspectives of the sol-gel method are described in the article. (author)

  14. Vanadium dioxide formed by the sol-gel process

    International Nuclear Information System (INIS)

    Potember, R.S.; Speck, K.R.; Hu, H.S.

    1990-01-01

    This patent describes a process for the deposition of a crystalline vanadium dioxide thin film. It comprises: providing a solution comprising a vanadium tetraalkoxide and solvent; allowing hydrolysis and condensation reactions to progressively form a homogeneous sol from the solution, applying a coating of the sol to the substrate; allowing a gel to form from the sol on the substrate by evaporating the solvent; dehydrating the gel by heat treatment under an inert atmosphere to form the crystalline vanadium dioxide film

  15. Salt-assisted and salt-suppressed sol-gel transitions of methylcellulose in water.

    Science.gov (United States)

    Xu, Y; Wang, C; Tam, K C; Li, L

    2004-02-03

    The effects of various salts on the sol-gel transition of aqueous methylcellulose (MC) solutions have been studied systematically by means of a micro differential scanning calorimeter. It was found that the heating process was endothermic while the cooling process was exothermic for both MC solutions with and without salts. The addition of salts did not change the patterns of gelation and degelation of MC. However, the salts could shift the sol-gel transition and the gel-sol transition to lower or higher temperatures from a pure MC solution, depending on the salt type. These opposite effects were termed the salt-assisted and salt-suppressed sol-gel transitions. Either the salt-assisted transition or the salt-suppressed sol-gel transition was a function of salt concentration. In addition, each salt was found to have its own concentration limit for producing a stable aqueous solution of MC at a given concentration of MC, which was related to the anionic charge density of the salt. Cations were proved to have weaker effects than anions. The "salt-out strength", defined as the salt effect per mole of anion, was obtained for each anion studied. The thermodynamic mechanisms involved in the salt-assisted and salt-suppressed sol-gel transitions are discussed.

  16. Classification of visualization exudates fundus images results using ...

    African Journals Online (AJOL)

    The kernel function settings; linear, polynomial, quadratic and RBF have an effect on the classification results. For SVM1, the best parameter in classifying pixels is linear kernel function. The visualization results using CAC and radar chart are classified using ts accuracy. It has proven to discriminated exudates and non ...

  17. Roles of abiotic losses, microbes, plant roots, and root exudates on phytoremediation of PAHs in a barren soil.

    Science.gov (United States)

    Sun, Tian-Ran; Cang, Long; Wang, Quan-Ying; Zhou, Dong-Mei; Cheng, Jie-Min; Xu, Hui

    2010-04-15

    Phytoremediation is an emerging technology for the remediation of polycyclic aromatic hydrocarbons (PAHs). In this study, pot experiments were conducted to evaluate the efficacy of phytoremediation of phenanthrene and pyrene in a typical low organic matter soil (3.75 g kg(-1)), and the contribution proportions of abiotic losses, microbes, plant roots, and root exudates were ascertained during the PAHs dissipation. The results indicated that contribution of abiotic losses from this soil was high both for phenanthrene (83.4%) and pyrene (57.2%). The contributions of root-exudates-enhanced biodegradation of phenanthrene (15.5%) and pyrene (21.3%) were higher than those of indigenous microbial degradation. The role of root exudates on dissipation of phenanthrene and pyrene was evident in this experiment. By the way, with the increasing of ring numbers in PAHs structures, the root-exudates-enhanced degradation became more and more important. BIOLOG-ECO plate analysis indicated that microbial community structure of the soil receiving root exudates had changed. The removal efficiency and substrate utilization rate in the treatment with plant roots were lower than the treatment only with root exudates, which suggested that possible competition between roots and microbes for nutrients had occurred in a low organic matter soil. 2009. Published by Elsevier B.V.

  18. Tuning of thermally induced sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid).

    Science.gov (United States)

    Jin, Naixiong; Zhang, Hao; Jin, Shi; Dadmun, Mark D; Zhao, Bin

    2012-03-15

    We report in this article a method to tune the sol-to-gel transitions of moderately concentrated aqueous solutions of doubly thermosensitive hydrophilic diblock copolymers that consist of two blocks exhibiting distinct lower critical solution temperatures (LCSTs) in water. A small amount of weak acid groups is statistically incorporated into the lower LCST block so that its LCST can be tuned by varying solution pH. Well-defined diblock copolymers, poly(methoxytri(ethylene glycol) acrylate)-b-poly(ethoxydi(ethylene glycol) acrylate-co-acrylic acid) (PTEGMA-b-P(DEGEA-co-AA)), were prepared by reversible addition-fragmentation chain transfer polymerization and postpolymerization modification. PTEGMA and PDEGEA are thermosensitive water-soluble polymers with LCSTs of 58 and 9 °C, respectively, in water. A 25 wt % aqueous solution of PTEGMA-b-P(DEGEA-co-AA) with a molar ratio of DEGEA to AA units of 100:5.2 at pH = 3.24 underwent multiple phase transitions upon heating, from a clear, free-flowing liquid (sol-to-gel transition temperature (T(sol-gel)) shifted to higher values, while the gel-to-sol transition (T(gel-sol)) and the clouding temperature (T(clouding)) of the sample remained essentially the same. These transitions and the tunability of T(sol-gel) originated from the thermosensitive properties of two blocks of the diblock copolymer and the pH dependence of the LCST of P(DEGEA-co-AA), which were confirmed by dynamic light scattering and differential scanning calorimetry studies. Using the vial inversion test method, we mapped out the C-shaped sol-gel phase diagrams of the diblock copolymer in aqueous buffers in the moderate concentration range at three different pH values (3.24, 5.58, and 5.82, all measured at ~0 °C). While the upper temperature boundaries overlapped, the lower temperature boundary shifted upward and the critical gelation concentration increased with the increase of pH. The AA content in PTEGMA-b-P(DEGEA-co-AA) was found to have a significant

  19. Low pH, aluminum, and phosphorus coordinately regulate malate exudation through GmALMT1 to improve soybean adaptation to acid soils.

    Science.gov (United States)

    Liang, Cuiyue; Piñeros, Miguel A; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V; Liao, Hong

    2013-03-01

    Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function.

  20. Preferential flow in the vadose zone and interface dynamics: Impact of microbial exudates

    Science.gov (United States)

    Li, Biting; Pales, Ashley R.; Clifford, Heather M.; Kupis, Shyla; Hennessy, Sarah; Liang, Wei-Zhen; Moysey, Stephen; Powell, Brian; Finneran, Kevin T.; Darnault, Christophe J. G.

    2018-03-01

    In the hydrological cycle, the infiltration process is a critical component in the distribution of water into the soil and in the groundwater system. The nonlinear dynamics of the soil infiltration process yield preferential flow which affects the water distribution in soil. Preferential flow is influenced by the interactions between water, soil, plants, and microorganisms. Although the relationship among the plant roots, their rhizodeposits and water transport in soil has been the subject of extensive study, the effect of microbial exudates has been studied in only a few cases. Here the authors investigated the influence of two artificial microbial exudates-catechol and riboflavin-on the infiltration process, particularly unstable fingered flow, one form of preferential flow. Flow experiments investigating the effects of types and concentrations of microbial exudates on unstable fingered flow were conducted in a two-dimensional tank that was filled with ASTM

  1. Exudation of Allelopathic Substances in Buckwheat (Fagopyrum esculentum Moench)

    Czech Academy of Sciences Publication Activity Database

    Kalinová, J.; Vrchotová, Naděžda; Tříska, Jan

    2007-01-01

    Roč. 55, č. 16 (2007), s. 6453-6459 ISSN 0021-8561 Institutional research plan: CEZ:AV0Z60870520 Keywords : Allelopathy * Epicatechin * Fagopyrum esculentum * palmitic acid * root exudates Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.532, year: 2007

  2. Real-time UV imaging of piroxicam diffusion and distribution from oil solutions into gels mimicking the subcutaneous matrix.

    Science.gov (United States)

    Ye, Fengbin; Larsen, Susan Weng; Yaghmur, Anan; Jensen, Henrik; Larsen, Claus; Østergaard, Jesper

    2012-05-12

    A novel real-time UV imaging approach for non-intrusive investigation of the diffusion and partitioning phenomena occurring during piroxicam release from medium chain triglyceride (MCT) solution into two hydrogel matrices is described. Two binary polymer/buffer gel matrices, 0.5% (w/v) agarose and 25% (w/v) Pluronic F127, were applied as simple models mimicking the subcutaneous tissue. The evolution of the absorbance maps as a function of time provided detailed information on the piroxicam release processes upon the exposure of the gel matrices to MCT. Using calibration curves, the concentration maps of piroxicam in the UV imaging area were determined. Regression of the longitudinal concentration-distance profiles, which were obtained using expressions derived from Fick's second law, provided the diffusivity and the distribution coefficients of piroxicam penetrated into the gels. The obtained MCT-agarose (pH 7.4) distribution coefficient of 1.4 was identical to the MCT-aqueous (pH 7.4) distribution coefficient determined by the shake-flask method whereas that of the MCT-Pluronic F127 system was four times less. The experimental data show that UV imaging may have considerable potential for investigating the transport properties of drug formulations intended for the subcutaneous administration. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. The Influence of Conditioning Agent on Phosphate Diffusion Coefficient through Polyacrylamide and Agarose Gel

    Directory of Open Access Journals (Sweden)

    Layta Dinira

    2013-03-01

    Full Text Available Excess phosphate in natural water can cause algae grow rapidly, to the extent causing many fish deaths that led to the extinction of certain species. Therefore, an analysis or periodic observations of phosphate levels in the water is needed. The commonly used method is diffusive gradient in thin films (DGT technique. The DGT technique is based on the ability of analyte to diffuse through a gel, which have a value named diffusion coefficient. This research was conducted in order to study the effect of different storage solution to the phosphate diffusion coefficient through polyacrylamide and agarose gels. Initial research performed with making the polyacrylamide and agarose gels. To observe the effect of different storage solutions, the gels partly stored in distilled water gel while the others are stored in a NaCl solution of 0.01 M. Phosphate diffusion coefficient was determined using Fick's Law after analyze the phosphate concentration using UV-Visible spectrophotometer. The results showed that phosphate diffusion coefficient was highest when polyacrylamide and agarose gels stored in NaCl solution of 0.01 M.

  4. Decision support system for the detection and grading of hard exudates from color fundus photographs

    Science.gov (United States)

    Jaafar, Hussain F.; Nandi, Asoke K.; Al-Nuaimy, Waleed

    2011-11-01

    Diabetic retinopathy is a major cause of blindness, and its earliest signs include damage to the blood vessels and the formation of lesions in the retina. Automated detection and grading of hard exudates from the color fundus image is a critical step in the automated screening system for diabetic retinopathy. We propose novel methods for the detection and grading of hard exudates and the main retinal structures. For exudate detection, a novel approach based on coarse-to-fine strategy and a new image-splitting method are proposed with overall sensitivity of 93.2% and positive predictive value of 83.7% at the pixel level. The average sensitivity of the blood vessel detection is 85%, and the success rate of fovea localization is 100%. For exudate grading, a polar fovea coordinate system is adopted in accordance with medical criteria. Because of its competitive performance and ability to deal efficiently with images of variable quality, the proposed technique offers promising and efficient performance as part of an automated screening system for diabetic retinopathy.

  5. Machine learning approach to automatic exudate detection in retinal images from diabetic patients

    Science.gov (United States)

    Sopharak, Akara; Dailey, Matthew N.; Uyyanonvara, Bunyarit; Barman, Sarah; Williamson, Tom; Thet Nwe, Khine; Aye Moe, Yin

    2010-01-01

    Exudates are among the preliminary signs of diabetic retinopathy, a major cause of vision loss in diabetic patients. Early detection of exudates could improve patients' chances to avoid blindness. In this paper, we present a series of experiments on feature selection and exudates classification using naive Bayes and support vector machine (SVM) classifiers. We first fit the naive Bayes model to a training set consisting of 15 features extracted from each of 115,867 positive examples of exudate pixels and an equal number of negative examples. We then perform feature selection on the naive Bayes model, repeatedly removing features from the classifier, one by one, until classification performance stops improving. To find the best SVM, we begin with the best feature set from the naive Bayes classifier, and repeatedly add the previously-removed features to the classifier. For each combination of features, we perform a grid search to determine the best combination of hyperparameters ν (tolerance for training errors) and γ (radial basis function width). We compare the best naive Bayes and SVM classifiers to a baseline nearest neighbour (NN) classifier using the best feature sets from both classifiers. We find that the naive Bayes and SVM classifiers perform better than the NN classifier. The overall best sensitivity, specificity, precision, and accuracy are 92.28%, 98.52%, 53.05%, and 98.41%, respectively.

  6. Exploring the transfer of recent plant photosynthates to soil microbes: mycorrhizal pathway vs direct root exudation

    Science.gov (United States)

    Kaiser, Christina; Kilburn, Matt R; Clode, Peta L; Fuchslueger, Lucia; Koranda, Marianne; Cliff, John B; Solaiman, Zakaria M; Murphy, Daniel V

    2015-01-01

    Plants rapidly release photoassimilated carbon (C) to the soil via direct root exudation and associated mycorrhizal fungi, with both pathways promoting plant nutrient availability. This study aimed to explore these pathways from the root's vascular bundle to soil microbial communities. Using nanoscale secondary ion mass spectrometry (NanoSIMS) imaging and 13C-phospho- and neutral lipid fatty acids, we traced in-situ flows of recently photoassimilated C of 13CO2-exposed wheat (Triticum aestivum) through arbuscular mycorrhiza (AM) into root- and hyphae-associated soil microbial communities. Intraradical hyphae of AM fungi were significantly 13C-enriched compared to other root-cortex areas after 8 h of labelling. Immature fine root areas close to the root tip, where AM features were absent, showed signs of passive C loss and co-location of photoassimilates with nitrogen taken up from the soil solution. A significant and exclusively fresh proportion of 13C-photosynthates was delivered through the AM pathway and was utilised by different microbial groups compared to C directly released by roots. Our results indicate that a major release of recent photosynthates into soil leave plant roots via AM intraradical hyphae already upstream of passive root exudations. AM fungi may act as a rapid hub for translocating fresh plant C to soil microbes. PMID:25382456

  7. Compositional differences in simulated root exudates elicit a limited functional and compositional response in soil microbial communities.

    Science.gov (United States)

    Strickland, Michael S; McCulley, Rebecca L; Nelson, Jim A; Bradford, Mark A

    2015-01-01

    Inputs of low molecular weight carbon (LMW-C) to soil - primarily via root exudates- are expected to be a major driver of microbial activity and source of stable soil organic carbon. It is expected that variation in the type and composition of LMW-C entering soil will influence microbial community composition and function. If this is the case then short-term changes in LMW-C inputs may alter processes regulated by these communities. To determine if change in the composition of LMW-C inputs influences microbial community function and composition, we conducted a 90 day microcosm experiment whereby soils sourced from three different land covers (meadows, deciduous forests, and white pine stands) were amended, at low concentrations, with one of eight simulated root exudate treatments. Treatments included no addition of LMW-C, and the full factorial combination of glucose, glycine, and oxalic acid. After 90 days, we conducted a functional response assay and determined microbial composition via phospholipid fatty acid analysis. Whereas we noted a statistically significant effect of exudate treatments, this only accounted for ∼3% of the variation observed in function. In comparison, land cover and site explained ∼46 and ∼41% of the variation, respectively. This suggests that exudate composition has little influence on function compared to site/land cover specific factors. Supporting the finding that exudate effects were minor, we found that an absence of LMW-C elicited the greatest difference in function compared to those treatments receiving any LMW-C. Additionally, exudate treatments did not alter microbial community composition and observable differences were instead due to land cover. These results confirm the strong effects of land cover/site legacies on soil microbial communities. In contrast, short-term changes in exudate composition, at meaningful concentrations, may have little impact on microbial function and composition.

  8. Patterns of organic acids exuded by pioneering fungi from a glacier forefield are affected by carbohydrate sources

    Science.gov (United States)

    Brunner, Ivano; Goren, Asena; Schlumpf, Alessandro

    2014-01-01

    Bare soils in the area of retreating glaciers are ideal environments to study the role of microorganisms in the early soil formation and in processes of mineral weathering. The aim of our study was to investigate whether the source of carbohydrate would influence the patterns of organic acids exuded by fungal species. Three pioneering fungus species, isolated from fine granitic sediments in front of the Damma glacier from the central Swiss Alps, have previously been found to have the capability to exude organic acids and dissolve granite powder. In batch experiments, various carbohydrates, including glucose, cellulose, pectin, pollen, and cell remnants of cyanobacteria, fungi, and algae, were applied as carbohydrate sources and the patterns of exuded organic acids recorded. The results showed that two fungi, the zygomycete fungus Mucor hiemalis and the ascomycete fungus Penicillium chrysogenum, released a significantly higher amount of organic acids in dependence on specific carbohydrate sources. Pollen and algae as carbohydrate sources triggered significantly the exudation of malate in M. hiemalis, and pollen and cellulose that of oxalate in P. chrysogenum. We conclude that the occurrence of complex carbohydrate sources in nutrient-deficient deglaciated soils may positively influence the exudation of organic acids of fungi. In particular, pollen and remnants of other microorganisms can trigger the exudation of organic acids of fungi in order to promote the weathering of minerals and to make nutrients available that would otherwise be trapped in that cryospheric environment.

  9. Patterns of organic acids exuded by pioneering fungi from a glacier forefield are affected by carbohydrate sources

    International Nuclear Information System (INIS)

    Brunner, Ivano; Goren, Asena; Schlumpf, Alessandro

    2014-01-01

    Bare soils in the area of retreating glaciers are ideal environments to study the role of microorganisms in the early soil formation and in processes of mineral weathering. The aim of our study was to investigate whether the source of carbohydrate would influence the patterns of organic acids exuded by fungal species. Three pioneering fungus species, isolated from fine granitic sediments in front of the Damma glacier from the central Swiss Alps, have previously been found to have the capability to exude organic acids and dissolve granite powder. In batch experiments, various carbohydrates, including glucose, cellulose, pectin, pollen, and cell remnants of cyanobacteria, fungi, and algae, were applied as carbohydrate sources and the patterns of exuded organic acids recorded. The results showed that two fungi, the zygomycete fungus Mucor hiemalis and the ascomycete fungus Penicillium chrysogenum, released a significantly higher amount of organic acids in dependence on specific carbohydrate sources. Pollen and algae as carbohydrate sources triggered significantly the exudation of malate in M. hiemalis, and pollen and cellulose that of oxalate in P. chrysogenum. We conclude that the occurrence of complex carbohydrate sources in nutrient-deficient deglaciated soils may positively influence the exudation of organic acids of fungi. In particular, pollen and remnants of other microorganisms can trigger the exudation of organic acids of fungi in order to promote the weathering of minerals and to make nutrients available that would otherwise be trapped in that cryospheric environment. (paper)

  10. Amoeba-like self-oscillating polymeric fluids with autonomous sol-gel transition.

    Science.gov (United States)

    Onoda, Michika; Ueki, Takeshi; Tamate, Ryota; Shibayama, Mitsuhiro; Yoshida, Ryo

    2017-07-13

    In the field of polymer science, many kinds of polymeric material systems that show a sol-gel transition have been created. However, most systems are unidirectional stimuli-responsive systems that require physical signals such as a change in temperature. Here, we report on the design of a block copolymer solution that undergoes autonomous and periodic sol-gel transition under constant conditions without any on-off switching through external stimuli. The amplitude of this self-oscillation of the viscosity is about 2,000 mPa s. We also demonstrate an intermittent forward motion of a droplet of the polymer solution synchronized with the autonomous sol-gel transition. This polymer solution bears the potential to become the base for a type of slime-like soft robot that can transform its shape kaleidoscopically and move autonomously, which is associated with the living amoeba that moves forward by a repeated sol-gel transition.

  11. Reduction of Exudates (Browning) in Sugarcane Micro Propagation ...

    African Journals Online (AJOL)

    ... of this variety, ascorbic acid and citric acid was added as constituent of the media using MS and stock at different concentrations. The browning was reduced drastically at the addition of 0.1g/litre ascorbic acid and 0.15g/litre citric acid. Keywords: reduction, exudates browning, micro propagation, sugarcane. Nig J. Biotech.

  12. High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration.

    Directory of Open Access Journals (Sweden)

    Laura Pertl

    Full Text Available High-density lipoproteins (HDL have long been implicated in the pathogenesis of age-related macular degeneration (AMD. However, conflicting results have been reported with regard to the associations of AMD with HDL-cholesterol levels. The present study is the first to assess HDL composition and metrics of HDL function in patients with exudative AMD and control patients.Blood samples were collected from 29 patients with exudative AMD and 26 age-matched control patients. Major HDL associated apolipoproteins were determined in apoB-depleted serum by immunoturbidimetry or ELISA, HDL-associated lipids were quantified enzymatically. To get an integrated measure of HDL quantity and quality, we assessed several metrics of HDL function, including cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities using apoB-depleted serum from study participants.In our study, we observed that the HDL associated acute phase protein serum amyloid A (SAA was significantly increased in AMD patients (p<0.01, whereas all other assessed apolipoproteins including ApoA-I, apoA-II, apoC-II, apoC-III and apoE as well as major HDL associated lipids were not altered. HDL efflux capacity, anti-oxidative capacity and arylesterase activity were not different in AMD patients when compared with the control group. The ability of apoB-depleted serum to inhibit monocyte NF-κB expression was significantly improved in AMD patients (mean difference (MD -5.6, p<0.01. Moreover, lipoprotein-associated phospholipase A2 activity, a marker of vascular inflammation, was decreased in AMD subjects (MD -24.1, p<0.01.The investigated metrics of HDL composition and HDL function were not associated with exudative AMD in this study, despite an increased content of HDL associated SAA in AMD patients. Unexpectedly, anti-inflammatory activity of apoB-depleted serum was even increased in our study. Our data suggest that the investigated parameters of serum HDL function showed no

  13. Exudative epidermitis in pigs caused by toxigenic Staphylococcus chromogenes.

    Science.gov (United States)

    Andresen, Lars Ole; Ahrens, Peter; Daugaard, Lise; Bille-Hansen, Vivi

    2005-02-25

    Staphylococcus chromogenes is closely related to Staphylococcus hyicus, which is recognised as the causative agent of exudative epidermitis (EE) in pigs. S. chromogenes is part of the normal skin flora of pigs, cattle and poultry and has so far been considered non-pathogenic to pigs. A strain of S. chromogenes producing exfoliative toxin type B, ExhB, was identified by the use of a multiplex PCR specific for the exfoliative toxins from S. hyicus. The exfoliative toxin from S. chromogenes reacted in immunoblot analysis with polyclonal and monoclonal antibodies specific to ExhB from S. hyicus and had an apparent molecular weight of 30 kDa. Sequencing the gene encoding the exfoliative toxin from S. chromogenes revealed that the molecular weight of the toxin with the signal peptide and the mature toxin was 30,553 and 26,694 Da, respectively. Comparison of the exhB genes from S. chromogenes strain VA654 and S. hyicus strain 1289D-88 showed differences in seven base pairs of the DNA sequences and in two amino acid residues in the deduced amino acid sequences. Pigs were experimentally inoculated with S. chromogenes strain VA654. By clinical observations and histopathological evaluation of the skin alterations, all pigs revealed development of generalized exudative epidermitis. No toxin producing S. hyicus was isolated from the pigs and all ExhB-positive bacterial isolates were identified as S. chromogenes. This confirmed that the disease-causing agent was the inoculated S. chromogenes strain VA654. The results of this study show that S. chromogenes may cause exudative epidermitis in pigs.

  14. SODIUM DI-N-DODECYL PHOSPHATE VESICLES IN AQUEOUS-SOLUTION - EFFECTS OF ETHANOL, PROPANOL, AND TETRAHYDROFURAN ON THE GEL TO LIQUID-PHASE TRANSITION

    NARCIS (Netherlands)

    BLANDAMER, MJ; BRIGGS, B; BUTT, MD; WATERS, M; CULLIS, PM; ENGBERTS, JBFN; HOEKSTRA, D; MOHANTY, RK

    1994-01-01

    For aqueous solutions containing vesicles formed by sodium di-n-dodecyl phosphate, the gel to liquid-crystal transition occurs near 35 degrees C, the temperature T-m. When ethanol is added, T-m decreases, but the scan shows evidence of several transitions as more alcohol is added. The effect of

  15. Sol-gel derived sorbents

    Science.gov (United States)

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  16. Experimental study and thermodynamic modelling of methane clathrate hydrate dissociation conditions in silica gel porous media in the presence of methanol aqueous solution

    International Nuclear Information System (INIS)

    Hashemi, Hamed; Javanmardi, Jafar; Zarifi, Mojdeh; Eslamimanesh, Ali; Mohammadi, Amir H.

    2012-01-01

    Highlights: ► Phase equilibria of hydrates of methane in confined silica gel pores are reported. ► Dissociation data in the presences of methanol aqueous solution are also measured. ► A thermodynamic model is developed for prediction of the obtained data. ► Acceptable agreement is found between the obtained data and the predicted results. - Abstract: In this work, the phase equilibria of clathrate hydrates of methane in the presence of pure water and 0.035 mass fraction of methanol aqueous solution in confined silica gel pores with (10 and 15) nm mean diameters are measured and reported. A thermodynamic model is also developed for prediction of the obtained experimental hydrate dissociation data. The Valderrama–Patel–Teja (VPT-EoS) equation of state (EoS) accompanied with the non-density dependent (NDD) mixing rules coupled with a previously developed activity model are applied to evaluate the fugacity of the species present and the activity coefficient of water in methanol aqueous solution. Acceptable agreement between the reported data and the predicted results using the proposed model and an existing method reported in the literature demonstrates the reliability of the presented model.

  17. Applications of sol gel ceramic coatings

    International Nuclear Information System (INIS)

    Barrow, D.

    1996-01-01

    The sol gel method is a chemical technique in which polycrystalline ceramic films are fabricated from a solution of organometallic precursors. The technique is attractive for many industrial applications because it is a simple (films are processed in air), flexible (can be used to coat complex geometries) and cost effective (does not require expensive equipment) process. In addition, dense, high quality coatings can be achieved at much lower temperatures than is generally required for sintering bulk ceramics. In this paper the conventional sol gel method and the new datec process are reviewed and potential applications of sol gel coatings in automotive, aerospace, petrochemical, nuclear and electronic industries are discussed. (orig.)

  18. Extraction of americium (III) by thermosensitive polymer gel copolymerized with acidic phosphorus compound

    International Nuclear Information System (INIS)

    Takeshita, Kenji; Nakano, Yoshio; Matsumura, Tatsuro

    2001-01-01

    A new gel-liquid extraction using a thermosensitive gel was proposed. The thermosensitive gel shows the conformational change of polymer network with temperature, which is known as the phase transition phenomena of gel. The extraction rate and equilibrium of Am(III) in an aqueous solution containing nitrate ion were measured batchwise by using a thermosensitive gel, N-isopropylacrylamide (NIPA) copolymerized with 2-methacryloyloxy- ethylacidphosphate (MR). The effects of the conformational change of polymer network on the extraction rate and equilibrium were discussed. The distribution ratio of Am(III) showed a large value at higher than LCST (low critical solution temperature; 34degC) and was decreased by the phase transition of gel from shrinking to swelling with decreasing temperature. The extraction of Am(III) in the aqueous solution and the release of Am(III) extracted in the gel were repeated stably by the temperature swing operation between 40 and 3degC. The extraction mechanism of Am(III) was described simply as Am 3+ + 3R - OH=(R-O) 3 Am + 3H + (R-OH: MR). The equilibrium constant at the shrinking state (40degC) was more than 3 times of that at swelling state (3degC). The gel-phase diffusivity of Eu(III) used as a substitute of Am(III) was evaluated as the order of 10 -12 m 2 /s at either of 3 or 40degC, which was similar to those for practical extraction chromatographic resins. The temperature-response of gel for the extraction of Eu(III) was very excellent without delay even for the rapid temperature change at 10degC/min. These results suggest that the extraction and release of Am(III) in an aqueous solution can be controlled by the conformational change of polymer network of thermosensitive gel. (author)

  19. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes.

    Science.gov (United States)

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C J

    2015-02-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Correlation between organic acid exudation and metal uptake by ectomycorrhizal fungi grown on pond ash in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ray, P.; Adholeya, A. [Energy & Resources Institute, New Delhi (India). India Habitat Centre

    2009-04-15

    Experiments were conducted to investigate the effect of coal ash on organic acid exudation and subsequent metal uptake by ectomycorrhizal fungi. Four isolates of ectomycorrhizal fungi namely, Pisolithus tinctorius (EM-1293 and EM-1299), Scleroderma verucosum (EM-1283) and Scleroderma cepa (EM-1233) were grown on pond ash moistened with Modified Melin-Norkans medium in vitro. Exudation of formic acid, malic acid and succinic acid by these fungi were detected by HPLC. Mycelial accumulation of Al, As, Cd, Cr, Ni and Pb by these fungi was assayed by atomic absorption spectrophotometer. Relationship between organic acid exudation and metal uptake was determined using classical multivariate linear regression model. Correlation between organic acid exudation and metal uptake could be substantiated when several metals are considered collectively. The finding supports the widespread role of low molecular weight organic acid as a function of tolerance, when exposed to metals in vitro.

  1. ADSORPSI ION SIANIDA DALAM LARUTAN MENGGUNAKAN ADSORBEN HIBRIDA AMINOPROPIL SILIKA GEL DARI SEKAM PADI TERIMPREGNASI ALUMINIUM (Adsorption of Cyanide Ions in Solution Using a Hybrid Adsorbent Aminopropyl Silica Gel from Rice Husks of Impregnated With

    Directory of Open Access Journals (Sweden)

    Amaria Amaria

    2012-03-01

    aminopropil silica gel from rice husk that has been impregnated with aluminum (APSG-Al and silica gel impregnated with aluminum (SG-Al of rice husk silica gel as the material for the adsorption of cyanide ions in solution. The interaction between the adsorbent with cyanide ions in solution performed in a batch system. The parameters examined in this study were the influence of medium pH, the effect of interaction time and the effect of initial concentration of cyanide ion adsorption ability of adsorbent hybrid amino silica gel impregnated with aluminum. Quantitative Analysis of cyanide ions left in the filtrate was tested by means of ion selective electrode. The effect of interaction time data were analyzed with kinetic model, the data of the influence of cyanide ion concentration was analyzed by Langmuir adsorption isotherm model and Freundlich. The results showed that the infrared spectroscopic identification results show APSG-Al adsorbent has silanol groups (Si-OH, siloxil (Si-O-Si, primary amine group, NH2. The result of XRD analysis of the price of 2θ at 65.51 indicates that the aluminum impregnated with the silica in the form of alumina Al2O3. The result of adsorption of cyanide by the hybrid silica gel impregnated with aluminum aminopropil (APSG-Al showed maximum adsorption occurred at pH 5 was 67.62%, silica gel impregnated with aluminum was 51,11%. Study the kinetics of the effect of interaction time showed that the adsorbent APSG-Al and SG-Al-Al has the adsorption rate constant k1 is 2.7, 10-3and 1.9,10-3 min-1, respectively. Adsorption equilibrium data showed that the adsorbent APSG-Al and SG-Al tend to follow the adsorption isotherm model Freundlich.

  2. Behavior of water gel permissibles in coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Ribovich, J.; Watson, R.W.

    1979-01-01

    This paper presents an overview of the successful use of water gel permissibles, since their introduction in 1970, with an emphasis on some problems of behavior in their field application. One is the metal clip or ties used to seal the water gel package. Miners are occasionally hit by the 2.4 mm metal wire expelled from boreholes in normal shooting operations. Manufacturers have consequently reduced the mass of the metal ties by 25-50%, providing a partial solution. Another problem concerned two reported instances of misfired water gel burning after coal shooting operations. Extensive tests have offered no satisfactory solution as yet, except to point up a principal shortcoming of water gels: that of pressure desensitization. Two other factors affecting sensitivity, and possibly resulting in misfires, are low temperature and aging. There is a decline in air-gap sensitivity with prolonged storage but all approved water gels seem capable of meeting requirements for long periods under normal storage conditions. Low temperature tests indicate the majority of water gels become insensitive to a No. 6 EBC at temperatures easily attained in cold weather storage. An attempt was made to determine the minimum temperature at which a nitroglycerin-sensitized permisslbe could be initiated with a No. 8 cap; a particularly granular one was initiated as low as minus 196 C. (5 refs.) (In English)

  3. THE HYDROGEN ION CONCENTRATION OF JOINT EXUDATES IN RHEUMATIC FEVER AND OTHER FORMS OF ARTHRITIS.

    Science.gov (United States)

    Boots, R H; Cullen, G E

    1922-09-30

    1. The hydrogen ion concentration of joint exudates aspirated from patients ill with acute rheumatic fever, arthritis of undetermined origin, and bacterial arthritis was determined. The hydrogen ion concentrations of the joint exudates from patients with acute rheumatic fever approximated the normal reaction of blood, varying from pH 7.27 to 7.42. Exudates from patients with arthritis of undetermined origin varied in pH from 7.33 to 7.47. The pH of a joint effusion occurring in a patient with myocardial insufficiency was 7.34. Bacteriologically, all of these fluids were sterile by ordinary means of cultivation. An exudate aspirated from a knee infected with Staphylococcus aureus had a pH of 6.69, while that from a patient having an arthritis due to Streptococcus hoemolyticus was also acid, having a pH of 6.19. 2. Since a definitely acid medium is necessary for the liberation of free salicylic acid and since all of the joint fluids from patients with acute rheumatic fever were slightly alkaline, no free salicylic acid could possibly exist in such joint fluids following the administration of salicylates.

  4. Effect of Dunaliella tertiolecta organic exudates on the Fe(II) oxidation kinetics in seawater.

    Science.gov (United States)

    González, A G; Santana-Casiano, J M; González-Dávila, M; Pérez-Almeida, N; Suárez de Tangil, M

    2014-07-15

    The role played by the natural organic ligands excreted by the green algae Dunaliella tertiolecta on the Fe(II) oxidation rate constants was studied at different stages of growth. The concentration of dissolved organic carbon increased from 2.1 to 7.1 mg L(-1) over time of culture. The oxidation kinetics of Fe(II) was studied at nanomolar levels and under different physicochemical conditions of pH (7.2-8.2), temperature (5-35 °C), salinity (10-37), and dissolved organic carbon produced by cells (2.1-7.1 mg L(-1)). The experimental rate always decreased in the presence of organic exudates with respect to that in the control seawater. The Fe(II) oxidation rate constant was also studied in the context of Marcus theory, where ΔG° was 39.31-51.48 kJ mol(-1). A kinetic modeling approach was applied for computing the equilibrium and rate constants for Fe(II) and exudates present in solution, the Fe(II) speciation, and the contribution of each Fe(II) species to the overall oxidation rate constant. The best fit model took into account two acidity equilibrium constants for the Fe(II) complexing ligands with pKa,1=9.45 and pKa,2=4.9. The Fe(II) complexing constants were KFe(II)-LH=3×10(10) and KFe(II)-L=10(7), and the corresponding computed oxidation rates were 68±2 and 36±8 M(-1) min(-1), respectively.

  5. Effect of Sol Concentration, Aging and Drying Process on Cerium Stabilization Zirconium Gel Produced by External Gelation

    Science.gov (United States)

    Sukarsono, R.; Rachmawati, M.; Susilowati, S. R.; Husnurrofiq, D.; Nurwidyaningrum, K.; Dewi, A. K.

    2018-02-01

    Cerium Stabilized Zirconium gel has been prepared using external gelation process. As the raw materials was used ZrO(NO3)2 and Ce(NO3)4 nitrate salt which was dissolved with water into Zr-Ce nitrate mixture. The concentration of the nitrate salt mixture in the sol solution was varied by varying the concentration of zirconium and cerium nitrate in the sol solution and the addition of PVA and THFA to produce a sol with a viscosity of 40-60 cP. The viscosity range of 40-60cP is the viscosity of the sol solution that was easy to produce a good gel in the gelation apparatus. Sol solution was casted in a gelation column equipped with following tools: a 1 mm diameter drip nozzle which was vibrated to adjust the best frequency and amplitude of vibration, a flow meter to measure the flow rate of sol, flowing of NH3 gas to presolidification process. Gelation column was contained NH4OH solution as gelation medium and gel container to collect gel product. Gel obtained from the gelation process than processed with ageing, washing, drying and calcinations to get round gel and not broken at calcinations up to 500°C. The parameters observed in this research are variation of Zr nitrate concentration, Ce nitrate concentration, ratio of Zr and Ce in the sol and ageing and drying process method which was appropriate to get a good gel. From the gelation processes that has been done, it can be seen that with the presolidification process can be obtained a round gel and without presolidification process, produce not round gel. In the process of ageing to get not broken gel, ageing was done on the rotary flask so that during the ageing, gels rotate in gelation media. Gels, then be washed by dilute ammonium nitrate, demireralized water and iso prophyl alcohol. The washed gel was then dried by vacuum drying to form pores on the gel which become the path for the gases resulting from decomposition of the gel to exit the gel. Vacuum drying can prevent cracking because the pores allow the gel

  6. Study of gel grown mixed crystals of Bax Ca ((IO3) 4

    Indian Academy of Sciences (India)

    The growth of mixed crystals of BaCa1–(IO3)4 were carried out with simple gel method. The effect of various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of reactants on the growth was studied. Crystals having different morphologies and habits were obtained. The grown ...

  7. Studies on the pathogenesis of fever. III. The leucocytic origin of endogenous pyrogen in acute inflammatory exudates.

    Science.gov (United States)

    KING, M K; WOOD, W B

    1958-02-01

    The evolution of an acute inflammatory exudate produced in rabbits by the intraperitoneal injection of saline has been described. Evidence has been presented that polymorphonuclear leucocytes release endogenous pyrogen into the cell-free fluid of the exudate. Leucocytes from such exudates have also been shown to release pyrogen into the surrounding medium during incubation in vitro at 37 degrees C. The results of parallel cytological studies have provided evidence which suggests that the leucocytes give up their pyrogen while functionally intact. These observations add further support to the hypothesis that polymorphonuclear leucocytes play a significant role in the pathogenesis of fever.

  8. Growth and study of some gel grown group II single crystals of iodate

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Single crystals of calcium iodate and barium iodate were grown by simple gel technique by single diffusion method. The optimum conditions were established by varying various parameters such as pH of gel solution, gel concentration, gel setting time, concentration of the reactants etc. Crystals having different.

  9. Effects of Selected Root Exudate Components on Nitrogen Removal and Development of Denitrifying Bacteria in Constructed Wetlands

    Directory of Open Access Journals (Sweden)

    Hailu Wu

    2017-06-01

    Full Text Available Root exudates, particularly low molecular weight carbon (LMWC substrates, are major drivers of bacterial diversity and activity in the rhizosphere environment. However, it is not well understood how specific LMWC compounds—such as organic acids, soluble sugars, and amino acids—influence the community structures of denitrifying bacteria or if there are specific functions of LMWC substrates that preferentially respond to nitrogen (N removal in constructed wetlands (CWs. To address these knowledge gaps, we added mixtures of artificial exudates to CW microcosms containing N pollutant. N removal efficiency was observed over a 48-h experimental period, and at the end of the experiment, DNA was extracted from microbial samples for assessment of the bacterial community. The removal efficiencies of TN for the exudates treatments were higher than for control groups by 47.1–58.67%. Organic acid and soluble sugar treatments increased N removal, while amino acids were negative to N removal. The microbial community was changed when artificial exudates were added, but there were no significant relationships between LMWC compounds and bacterial community composition. These results indicate that although the responses of community structures of denitrifying bacteria to LMWC additions are still uncertain, there is evidence for N removal in response to exudate additions across LMWC types.

  10. Immunotherapy for choroidal neovascularization in a laser-induced mouse model simulating exudative (wet) macular degeneration

    Science.gov (United States)

    Bora, Puran S.; Hu, Zhiwei; Tezel, Tongalp H.; Sohn, Jeong-Hyeon; Kang, Shin Goo; Cruz, Jose M. C.; Bora, Nalini S.; Garen, Alan; Kaplan, Henry J.

    2003-03-01

    Age-related macular degeneration (AMD) is the leading cause of blindness after age 55 in the industrialized world. Severe loss of central vision frequently occurs with the exudative (wet) form of AMD, as a result of the formation of a pathological choroidal neovasculature (CNV) that damages the macular region of the retina. We tested the effect of an immunotherapy procedure, which had been shown to destroy the pathological neovasculature in solid tumors, on the formation of laser-induced CNV in a mouse model simulating exudative AMD in humans. The procedure involves administering an Icon molecule that binds with high affinity and specificity to tissue factor (TF), resulting in the activation of a potent cytolytic immune response against cells expressing TF. The Icon binds selectively to TF on the vascular endothelium of a CNV in the mouse and pig models and also on the CNV of patients with exudative AMD. Here we show that the Icon dramatically reduces the frequency of CNV formation in the mouse model. After laser treatment to induce CNV formation, the mice were injected either with an adenoviral vector encoding the Icon, resulting in synthesis of the Icon by vector-infected mouse cells, or with the Icon protein. The route of injection was i.v. or intraocular. The efficacy of the Icon in preventing formation of laser-induced CNV depends on binding selectively to the CNV. Because the Icon binds selectively to the CNV in exudative AMD as well as to laser-induced CNV, the Icon might also be efficacious for treating patients with exudative AMD.

  11. Influence of Spirulina platensis exudates on the endocrine and nervous systems of a mammalian model

    OpenAIRE

    Samah M.M. Fathy; Ashraf M.M. Essa

    2015-01-01

    Objective: To investigate the effect of intra-peritoneal injection of purified exudates of axenic Spirulina platensis on the mammalian endocrine and nervous systems. Methods: The intra-peritoneal injection of the cyanobacterial exudates in mice was applied. Sex hormonal levels of testosterone and progesterone were measured using radioimmunoassay while the follicular stimulating hormone and luteinizing hormone were evaluated by direct chemiluminescence. In addition, superoxide dismutase, ca...

  12. Comparative effectiveness of the methods adenoidectomy in cнildren with exudative otitis media

    Directory of Open Access Journals (Sweden)

    Gusakov A.

    2016-03-01

    Full Text Available Actuality: A thorough sanation of the nasopharynx is essential for successful treatment of the exudative otitis media (EOM. The literature describes in detail the state of the nasopharynx after different types of adenoidectomy. The classifications of the location of the remnants of lymphoid tissue and the extent of scarring in the nasopharynx are given.The subject of this work is to trace the relationship of postoperative nasopharyngeal changes with recurrent EOM. Objective: To study the immediate and long-term results of different methods of surgical treatment of hypertrophy of the nasopharyngeal lymphoid tissue in children with exudative otitis media. Materials and Methods: This paper presents information on the results of treatment of 62 children of 5–7 years suffering from exudative otitis media. Observations were carried out in two groups of patients. The first group included 28 children previously undergone adenoidectomy, with the signs of recurrent exudative otitis. The second group included 34 children with exudative otitis previously untreated surgically. The task of the investigation is to study the effectiveness of endonasal and extranasal methods of surgical removal of nasopharengeal lymphoid tissue with a minimum probability of scar obliteration of the mouth of the Eustachian tube. Results and discussion: The priority method in nasopharengeal surgery in children is extranasal access with shaver technology in conjunction with cold plasma surgery. The using of these methods gives a clear visualization of the operating field under conditions of moderately bleeding wound. On the other hand, endonasal approach is associated with traumatization of the nasal mucosa with incomplete volume visualization of the surgical field. This combination can result in a longer healing of the surgical wound, the formation of adhesions of the nasal cavity and scarring in the nasopharynx. Complete visualization of the operating field significantly

  13. Synthesis and characterization of a cryo gel starting from chitosan and their study as adsorbent of Cu (II) ions in aqueous solution

    International Nuclear Information System (INIS)

    Arcos A, A. J.

    2012-01-01

    The present work consisted in the synthesis of cryo gels from chitosan, which were cross-linked with ethylene glycol diglycidyl ether to obtain a stable, porous and resistant material to the interaction with aqueous solutions, in order that can be used in metal sorption processes. The performed synthesis consisted in a aqueous chitosan gel preparation crosslinked with ethylene glycol diglycidyl ether (Edge), evaluating two levels of crosslinking (1 and 2%); later to obtain the cryo gels, the aqueous gels were subjected to an ice segregation induced self-assembly process (ISISA), considering two levels of speed of materials formation. The obtained materials were characterized first determining their solubility in aqueous solutions and to the pair was determined the degree of swelling of the materials. Later, were used techniques like: the sweeping electronic microscopy to be able to observe the morphology of the obtained cryo gels, X-ray diffraction to know the crystallinity of the same, zeta potential with the aim of know the electrical potential in the materials, specific area determination, Fourier transformation infrared spectroscopy (Ftir) and X-ray photoelectrons spectroscopy (XP S), to know the functional groups and chemical interactions of the present elements in the materials before and after the copper ions sorption. The evaluation of the cryo gels as sorbents was performed obtaining the sorption kinetics for the Cu (II) ion at 25 and 30 grades C, and adjusting the experimental data obtained to the Lagergren and Ho kinetic models, as well as was performed adsorption isotherms at 25 and 35 grades C for the copper ion, adjusting the obtained data to the Langmuir, Freundlich and Langmuir-Freundlich models. In general, it was observed that the obtained materials show a macroporous structure, which presents and uniform swelling without significant deformations. Furthermore, was observed that the speed of formation of the materials affects the pores size and the

  14. EXPERIENCE OF TREATMENT WITH FENSPIRIDE IN CHILDREN WITH CHRONIC EXUDATIVE OTITIS MEDIA AFTER TYMPANOSTOMY

    OpenAIRE

    L.A. Toropova; T.V. Zhuikova; N.I. Marysheva; A.I. Nikolaeva; Yu.S. Maiorova

    2009-01-01

    The trial presents the analysis of factors predisposing to exudative otitis media development in 709 children, needing regular audiologist’s check-up. It was shown that dominating risk factor of auditory tube’s function disorders is hypertrophy of palatine tonsil (it was detected in 69% of children). Besides, doctors from children’s out-patient clinics often use conservative treatment in children with chronic exudative otitis media. Analysis of data obtained at the time of treatment of 180 ho...

  15. Adsorption isotherm studies of chromium (VI) from aqueous solutions using sol-gel hydrotalcite-like compounds

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Ramirez, Esthela, E-mail: ramosre@quijote.ugto.mx [Centro de Investigaciones en Quimica Inorganica de la Universidad de Guanajuato, Noria Alta s/n, Col. Noria Alta, C.P. 36050, Guanajuato, Gto. (Mexico); Gutierrez Ortega, Norma L.; Conteras Soto, Cesar A. [Centro de Investigaciones en Quimica Inorganica de la Universidad de Guanajuato, Noria Alta s/n, Col. Noria Alta, C.P. 36050, Guanajuato, Gto. (Mexico); Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca s/n, km 36.5, La Marquesa, Coyoacan Mexico, C.P. 52750 (Mexico); Olguin Gutierrez, Maria T. [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca s/n, km 36.5, La Marquesa, Coyoacan Mexico, C.P. 52750 (Mexico)

    2009-12-30

    In under-developed countries, industries such as paint and pigment manufacturing, leather tanning, chrome plating and textile processing, usually discharge effluents containing Cr(VI) and Cr(III) into municipal sanitary sewers. It has been reported that Cr(VI) acts as a powerful epithelial irritant and as a human carcinogen. In the present work, hydrotalcite-like compounds with a Mg/Al ratio = 2 were synthesized by the sol-gel method. The hydrotalcite-like compounds and their corresponding thermally treated products were characterized by powder X-ray diffraction, infrared spectroscopy and N{sub 2} adsorption. The hydrotalcite-like compounds and the heated solids were used as adsorbents for Cr(VI) in aqueous solutions. Adsorption isotherm studies of Cr(VI) from aqueous solution are described. The adsorbent capacity was determined using the Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models. The Cr(VI) adsorption isotherm data fit best to the Langmuir isotherm model. The maximum Cr(VI) uptake by hydrotalcite and the heated solids was determined using the Langmuir equation and was found to range between 26 and 29 mg Cr(VI)/g adsorbent.

  16. Adsorption isotherm studies of chromium (VI) from aqueous solutions using sol-gel hydrotalcite-like compounds

    International Nuclear Information System (INIS)

    Ramos-Ramirez, Esthela; Gutierrez Ortega, Norma L.; Conteras Soto, Cesar A.; Olguin Gutierrez, Maria T.

    2009-01-01

    In under-developed countries, industries such as paint and pigment manufacturing, leather tanning, chrome plating and textile processing, usually discharge effluents containing Cr(VI) and Cr(III) into municipal sanitary sewers. It has been reported that Cr(VI) acts as a powerful epithelial irritant and as a human carcinogen. In the present work, hydrotalcite-like compounds with a Mg/Al ratio = 2 were synthesized by the sol-gel method. The hydrotalcite-like compounds and their corresponding thermally treated products were characterized by powder X-ray diffraction, infrared spectroscopy and N 2 adsorption. The hydrotalcite-like compounds and the heated solids were used as adsorbents for Cr(VI) in aqueous solutions. Adsorption isotherm studies of Cr(VI) from aqueous solution are described. The adsorbent capacity was determined using the Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models. The Cr(VI) adsorption isotherm data fit best to the Langmuir isotherm model. The maximum Cr(VI) uptake by hydrotalcite and the heated solids was determined using the Langmuir equation and was found to range between 26 and 29 mg Cr(VI)/g adsorbent.

  17. Adsorption isotherm studies of chromium (VI) from aqueous solutions using sol-gel hydrotalcite-like compounds.

    Science.gov (United States)

    Ramos-Ramírez, Esthela; Ortega, Norma L Gutiérrez; Soto, Cesar A Contreras; Gutiérrez, Maria T Olguín

    2009-12-30

    In under-developed countries, industries such as paint and pigment manufacturing, leather tanning, chrome plating and textile processing, usually discharge effluents containing Cr(VI) and Cr(III) into municipal sanitary sewers. It has been reported that Cr(VI) acts as a powerful epithelial irritant and as a human carcinogen. In the present work, hydrotalcite-like compounds with a Mg/Al ratio=2 were synthesized by the sol-gel method. The hydrotalcite-like compounds and their corresponding thermally treated products were characterized by powder X-ray diffraction, infrared spectroscopy and N(2) adsorption. The hydrotalcite-like compounds and the heated solids were used as adsorbents for Cr(VI) in aqueous solutions. Adsorption isotherm studies of Cr(VI) from aqueous solution are described. The adsorbent capacity was determined using the Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models. The Cr(VI) adsorption isotherm data fit best to the Langmuir isotherm model. The maximum Cr(VI) uptake by hydrotalcite and the heated solids was determined using the Langmuir equation and was found to range between 26 and 29 mg Cr(VI)/g adsorbent.

  18. Fibril Formation from Pea Protein and Sesequent Gel Formation

    NARCIS (Netherlands)

    Munialo, C.D.; Martin, A.H.; Linden, van der E.; Jongh, de H.H.J.

    2014-01-01

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20

  19. Fibril Formation from Pea Protein and Subsequent Gel Formation

    NARCIS (Netherlands)

    Munialo, XC.D.; Martin, A.H.; Linden, E. van der; Jongh, H.H.J de

    2014-01-01

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20

  20. Benzo[a]pyrene co-metabolism in the presence of plant root extracts and exudates: Implications for phytoremediation

    International Nuclear Information System (INIS)

    Rentz, Jeremy A.; Alvarez, Pedro J.J.; Schnoor, Jerald L.

    2005-01-01

    Benzo[a]pyrene, a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) was removed from solution by Sphingomonas yanoikuyae JAR02 while growing on root products as a primary carbon and energy source. Plant root extracts of osage orange (Maclura pomifera), hybrid willow (Salix albaxmatsudana), or kou (Cordia subcordata), or plant root exudates of white mulberry (Morus alba) supported 15-20% benzo[a]pyrene removal over 24 h that was similar to a succinate grown culture and an unfed acetonitrile control. No differences were observed between the different root products tested. Mineralization of 14 C-7-benzo[a]pyrene by S. yanoikuyae JAR02 yielded 0.2 to 0.3% 14 CO 2 when grown with plant root products. Collectively, these observations were consistent with field observations of enhanced phytoremediation of HMW PAH and corroborated the hypothesis that co-metabolism may be a plant/microbe interaction important to rhizoremediation. However, degradation and mineralization was much less for root product-exposed cultures than salicylate-induced cultures, and suggested the rhizosphere may not be an optimal environment for HMW PAH degradation by Sphingomonas yanoikuyae JAR02. - Bacterial benzo[a]pyrene cometabolism, a plant-microbe interaction affecting polycyclic aromatic hydrocarbon phytoremediation was demonstrated with Sphingomonas yanoikuyae JAR02 that utilized plant root extracts and exudates as primary substrates

  1. Total antioxidant potential of resinous exudates from Heliotropium species, and a comparison of the ABTS and DPPH methods.

    Science.gov (United States)

    Lissi, E A; Modak, B; Torres, R; Escobar, J; Urzua, A

    1999-06-01

    Total reactive antioxidant potential (TRAP) of resinous exudates from Heliotropium species was evaluated by measuring the bleaching of stable free radicals. The antioxidant capacity of the resinous exudates in Trolox equivalents, evaluated from the bleaching of ABTS derived radical cations, ranged from 2.0 M (H. huascoense) to 5.2 M (H. stenophyllum), indicating a very high concentration of phenolic compounds. Considerably smaller values were obtained by measuring the bleaching of DPPH radicals. The ratio between the values obtained employing ABTS derived radicals and DPPH, ranged from 37 (H. megalanthum) to 4.5 (H. chenopodiaceum variety typica). The magnitude of the difference can be considered as an indication of the relative reactivity of the antioxidants present in the exudates. Similar ratios were observed when stoichiometric coefficients were evaluated for representative purified flavonoids obtained from the resinous exudates.

  2. PRODUCTION, DIELECTRIC PROPERTY AND MICROWAVE ABSORPTION PROPERTY OF SiC(Fe SOLID SOLUTION POWDER BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    XIAOLEI SU

    2014-03-01

    Full Text Available SiC(Fe solid solution powders were synthesized by sol–gel method under different reaction time, using methyltriethoxysilane as the silicon and carbon source and analytic ferric chloride as the dopant, respectively. The synthesized powders have been characterized by XRD, SEM and Raman spectra. Results show that the lattice constant decreases with increasing reaction time. The electric permittivities of SiC samples were determined in the frequency range of 8.2 ~ 12.4 GHz. Results show that the permittivity of SiC decreases with increasing reaction time. The SiC(Fe solid solution powder with reaction time of 4 h with 2 mm thickness exhibit the best microwave absorption property in X-band range (8.2 - 12.4 GHz. The microwave absorption mechanism has been discussed.

  3. Effect of gum tragacanth exuded by three Iranian Astragalus on mixed milk protein system during acid gelation.

    Science.gov (United States)

    Nejatian, Mohammad; Hatami, Masoud; Mohammadifar, Mohammad Amin

    2013-02-01

    The effects of various concentrations of three species of gum tragacanth on the gelation process, microstructure and viscoelastic properties of milk protein mixed gels acidified at 37°C by glucono-δ-lactone (GDL) were investigated using dynamic rheometry and microscopy. According to rheological measurements, the addition of gum tragacanth in the range of 0.05-0.2% (w/w) into milk protein dispersions led to a weaker structure for the milk protein network, compared to the control sample. This weakening effect could be eliminated by adding 0.3% (w/w) gum tragacanth exudates from A. gossypinus; the compositional features of gum tragacanth may have been responsible for the improved protein-protein interactions, greater structural strength and reduced gelation time onset. It was determined by scanning electron microscopy that the addition of gum tragacanth at a low concentration caused the density of the matrix to increase, while an open structure was observed in the presence of a higher gum concentration. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Sol-gel method for encapsulating molecules

    Science.gov (United States)

    Brinker, C. Jeffrey; Ashley, Carol S.; Bhatia, Rimple; Singh, Anup K.

    2002-01-01

    A method for encapsulating organic molecules, and in particular, biomolecules using sol-gel chemistry. A silica sol is prepared from an aqueous alkali metal silicate solution, such as a mixture of silicon dioxide and sodium or potassium oxide in water. The pH is adjusted to a suitably low value to stabilize the sol by minimizing the rate of siloxane condensation, thereby allowing storage stability of the sol prior to gelation. The organic molecules, generally in solution, is then added with the organic molecules being encapsulated in the sol matrix. After aging, either a thin film can be prepared or a gel can be formed with the encapsulated molecules. Depending upon the acid used, pH, and other processing conditions, the gelation time can be from one minute up to several days. In the method of the present invention, no alcohols are generated as by-products during the sol-gel and encapsulation steps. The organic molecules can be added at any desired pH value, where the pH value is generally chosen to achieve the desired reactivity of the organic molecules. The method of the present invention thereby presents a sufficiently mild encapsulation method to retain a significant portion of the activity of the biomolecules, compared with the activity of the biomolecules in free solution.

  5. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  6. Method of making ionic liquid mediated sol-gel sorbents

    Science.gov (United States)

    Malik, Abdul; Shearrow, Anne M.

    2017-01-31

    Ionic liquid (IL)-mediated sol-gel hybrid organic-inorganic materials present enormous potential for effective use in analytical microextraction. One obstacle to materializing this prospect arises from high viscosity of ILs significantly slowing down sol-gel reactions. A method was developed which provides phosphonium-based, pyridinium-based, and imidazolium-based IL-mediated advanced sol-gel organic-inorganic hybrid materials for capillary microextraction. Scanning electron microscopy results demonstrate that ILs can serve as porogenic agents in sol-gel reactions. IL-mediated sol-gel coatings prepared with silanol-terminated polymers provided up to 28 times higher extractions compared to analogous sol-gel coatings prepared without any IL in the sol solution. This study shows that IL-generated porous morphology alone is not enough to provide effective extraction media: careful choice of the organic polymer and the precursor with close sol-gel reactivity must be made to ensure effective chemical bonding of the organic polymer to the created sol-gel material to be able to provide the desired sorbent characteristics.

  7. Spatially resolved speckle-correlometry of sol-gel transition

    Science.gov (United States)

    Isaeva, A. A.; Isaeva, E. A.; Pantyukov, A. V.; Zimnyakov, D. A.

    2018-04-01

    Sol-gel transition was studied using the speckle correlometry method with a localized light source and spatial filtering of backscattered radiation. Water solutions of technical or food gelatin with added TiO2 nanoparticles were used as studied objects. Structural transformation of "sol-gel" system was studied at various temperatures from 25°C to 50°C using analysis of the correlation and structure functions of speckle intensity fluctuations. The characteristic temperatures of "sol - gel" transition were evaluated for studied systems. Obtained results can be used for various applications in biomedicine and food industry.

  8. Sol-gel processing with inorganic metal salt precursors

    Science.gov (United States)

    Hu, Zhong-Cheng

    2004-10-19

    Methods for sol-gel processing that generally involve mixing together an inorganic metal salt, water, and a water miscible alcohol or other organic solvent, at room temperature with a macromolecular dispersant material, such as hydroxypropyl cellulose (HPC) added. The resulting homogenous solution is incubated at a desired temperature and time to result in a desired product. The methods enable production of high quality sols and gels at lower temperatures than standard methods. The methods enable production of nanosize sols from inorganic metal salts. The methods offer sol-gel processing from inorganic metal salts.

  9. Nasal mucosa secretion exudation response to cold air in bronchial asthma patients

    Directory of Open Access Journals (Sweden)

    Eduard V. Nekrasov

    2017-01-01

    Full Text Available Background. Combined airway hyper responsiveness to cold and hypoosmotic stimuli in asthma patients results in impairment of lung respiration function and poor disease control compared to patients with isolated airway hyper responsiveness to only one of the stimuli or without such responsiveness that can be connected with edema or mucus hypersecretion.Aim. The purpose of the study is the estimation of the processes of mucin secretion, plasma exudation and oxidative stress in response to cold air in asthma patients with combined airway responsiveness to cold and hypoosmotic stimuli using nasal mucosa as a model.Materials and methods. 23 patients with asthma participated in the study. For the nasal lavage procedure, a nasal cavity was pre-washed at least three times in 5-min intervals with 5 ml saline solution (~36 °C. A control nasal lavage was done 5 min after the last washing with a dwelling time of 1 min in the nasal cavity. Directly after the control lavage, a cold air nasal challenge was done: a participant was asked to breathe deeply at the pace of a metronome to ensure hyperventilation inhaling cold air (–20 °C through the nose and exhaling through the mouth for 5 min. Nasal lavages were taken at 1 min, 15, and 30 min after the challenge. Mucin secretion was estimated on the basis of total protein (TP content, total carbohydrates (TC, and water-soluble forms of mucins MUC5AC and MUC5B in the lavage fluids. For the estimation of plasma exudation, the concentration of α2-macroglobulin (α2-MG was measured. Oxidative stress was estimated by the content of thiobarbituric acid-reactive substances (TBARS in lavage fluid. Lung function and airway responsiveness were studied by the forced expiration spirometry method and the bronchial challenge tests with isocapnic cold air hyperventilation (CAHV and distilled water inhalation (DWI.Results. According to the bronchial challenge tests, the patients were divided into groups: 1 without airway

  10. Differential exudation of two benzoxazinoids--one of the determining factors for seedling allelopathy of Triticeae species.

    Science.gov (United States)

    Belz, Regina G; Hurle, Karl

    2005-01-26

    Benzoxazinoids (Bx) are natural phytotoxins that function as chemical defense compounds in several species. The release of Bx by intact plant roots associated these compounds with root allelopathy in Triticeae species; however, the significance of exudate concentrations of Bx for plant-plant interactions is still a controversial question. A biological screening of 146 cultivars of four Triticeae species (Triticum aestivum L., Triticum durum Desf., Triticum spelta L., and Secale cereale L.) demonstrated a high cultivar dependence to suppress the root growth of Sinapis alba L. by root allelopathy in a dose-response bioassay. Only a few cultivars possessed a marked high or low allelopathic activity, whereby high-performance liquid chromatography-diode array detection analysis of root exudates revealed that these cultivars differed considerably in their ability to exude the two Bx aglucones, DIBOA [2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one] and DIMBOA [2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one]. The total amount of DIBOA and DIMBOA exuded showed a significant correlation to the growth inhibition in bioassay with a statistically estimated contribution to the overall allelopathic effect of 48-72%. In a bioassay with pure phytotoxins, Bx concentrations consistent with the amounts quantified in the screening bioassay caused detrimental effects on S. alba and almost reproduced the statistically estimated contribution. The observed causal association between the allelopathic activity under laboratory conditions and the exudate concentrations of Bx suggests that this association might have implications for the interference of Triticeae species in natural plant communities.

  11. The increase in pH during aging of porous sol-gel silica spheres

    NARCIS (Netherlands)

    Titulaer, M.K.; Kegel, W.K.; Jansen, J.B.H.; Geus, John W.

    1994-01-01

    The increase in pH in the hydrothermal fluid is studied after hydrothermal aging of porous silica gel spheres of 1–3 mm diameter. The porous silica spheres are formed by the sol-gel process from a supersaturated silica solution. The increase of the pH of the hydrothermal solution affects the silica

  12. Pea-root exudates and their effect upon root-nodule bacteria

    NARCIS (Netherlands)

    Egeraat, van A.W.S.M.

    1972-01-01

    The main purpose of this investigation was to study the exudation (mechanism, sites) of various compounds by roots of pea seedlings in relation to the growth of Rhizobium leguminosarum.

    Chapter 1 gives a survey of the literature pertaining to plant-root

  13. Process for encapsulating active agents in gels

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Oosterhaven, J.

    2001-01-01

    The present invention relates to a process for encapsulating an active agent in a biopolymer in the form of a gel, comprising the steps of: a) forming a dispersion or solution of the biopolymer in water; and b) adding the active agent to the dispersion or solution obtained in step a); wherein the

  14. Clinical case of exudative pleuritis in stallion

    International Nuclear Information System (INIS)

    Kanukov, D.; Petkov, P.; Stoyanchev, K.

    2001-01-01

    A casual exudative pleuritis in 2 years old stallion, Holsteiner breed, has been outlined. The disease is extremely rare in this country. Comprehensive examinations have been made during the period of hospitalization: daily clinical examinations, double renthgenography; regular haematological and biochemical tests; microbiological culture tests with an antibioticogram; laboratory tests of punctate and periodical ultrasound tests. The examinations and tests have been carried out at the Internal Noncontagious Disease Clinic at the Veterinary Faculty of the Thracian University in Stara Zagora

  15. Low pH, Aluminum, and Phosphorus Coordinately Regulate Malate Exudation through GmALMT1 to Improve Soybean Adaptation to Acid Soils1[W][OA

    Science.gov (United States)

    Liang, Cuiyue; Piñeros, Miguel A.; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V.; Liao, Hong

    2013-01-01

    Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function. PMID:23341359

  16. Microcontroller based instrumentation for the fuel pin preparation facility by sol-gel method

    International Nuclear Information System (INIS)

    Suhasini, B.; Prabhakar Rao, J.; Srinivas, K.C.

    2009-01-01

    The fuel pin preparation facility by Sol-Gel route has been set up at Chemistry Group at Indira Gandhi Centre for Atomic Research, Kalpakkam. Sol-Gel, a solution-gelation process involves conversion of solutions of nitrates of uranium-plutonium (at 0 deg C) into gel microspheres. To measure the exact quantities of the above solutions and to ensure their temperatures, a variety of sensors have been used at various stages in the plant. To monitor and acquire the data of process parameters used in the production and for an automated operation of the plant, a PC (master)-microcontroller (slave) based instrumentation has been developed along with acquisition software and a GU interface developed in Visual Basic. (author)

  17. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Short, K.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Sol-gel bonds have been produced between smooth, clean silicon substrates by spin-coating solutions containing partially hydrolysed silicon alkoxides. The two coated substrates were assembled and the resulting sandwich fired at temperatures ranging from 60 to 600 deg. C. The sol-gel coatings were characterised using attenuated total reflectance Fourier transform infrared spectroscopy, ellipsometry, and atomic force microscopy, while the corresponding bonded specimens were investigated using scanning electron microscopy and cross-sectional transmission electron microscopy. Mechanical properties were characterised using both microindentation and tensile testing. Bonding of silicon wafers has been successfully achieved at temperatures as low as 60 deg. C. At 300 deg. C, the interfacial fracture energy was 1.55 J/m 2 . At 600 deg. C, sol-gel bonding provided superior interfacial fracture energy over classical hydrophilic bonding (3.4 J/m 2 vs. 1.5 J/m 2 ). The increase in the interfacial fracture energy is related to the increase in film density due to the sintering of the sol-gel interface with increasing temperature. The superior interfacial fracture energy obtained by sol-gel bonding at low temperature is due to the formation of an interfacial layer, which chemically bonds the two sol-gel coatings on each wafer. Application of a tensile stress on the resulting bond leads to fracture of the samples at the silicon/sol-gel interface

  18. Hard exudates segmentation based on learned initial seeds and iterative graph cut.

    Science.gov (United States)

    Kusakunniran, Worapan; Wu, Qiang; Ritthipravat, Panrasee; Zhang, Jian

    2018-05-01

    (Background and Objective): The occurrence of hard exudates is one of the early signs of diabetic retinopathy which is one of the leading causes of the blindness. Many patients with diabetic retinopathy lose their vision because of the late detection of the disease. Thus, this paper is to propose a novel method of hard exudates segmentation in retinal images in an automatic way. (Methods): The existing methods are based on either supervised or unsupervised learning techniques. In addition, the learned segmentation models may often cause miss-detection and/or fault-detection of hard exudates, due to the lack of rich characteristics, the intra-variations, and the similarity with other components in the retinal image. Thus, in this paper, the supervised learning based on the multilayer perceptron (MLP) is only used to identify initial seeds with high confidences to be hard exudates. Then, the segmentation is finalized by unsupervised learning based on the iterative graph cut (GC) using clusters of initial seeds. Also, in order to reduce color intra-variations of hard exudates in different retinal images, the color transfer (CT) is applied to normalize their color information, in the pre-processing step. (Results): The experiments and comparisons with the other existing methods are based on the two well-known datasets, e_ophtha EX and DIARETDB1. It can be seen that the proposed method outperforms the other existing methods in the literature, with the sensitivity in the pixel-level of 0.891 for the DIARETDB1 dataset and 0.564 for the e_ophtha EX dataset. The cross datasets validation where the training process is performed on one dataset and the testing process is performed on another dataset is also evaluated in this paper, in order to illustrate the robustness of the proposed method. (Conclusions): This newly proposed method integrates the supervised learning and unsupervised learning based techniques. It achieves the improved performance, when compared with the

  19. Trigoxazonane, a monosubstituted trioxazonane from Trigonella foenum-graecum root exudate, inhibits Orobanche crenata seed germination.

    Science.gov (United States)

    Evidente, Antonio; Fernández-Aparicio, Mónica; Andolfi, Anna; Rubiales, Diego; Motta, Andrea

    2007-10-01

    Orobanche crenata is a major threat to grain legume production. Fenugreek (Trigonella foenum-graecum) is an annual legume that has been shown to effectively reduce O. crenata infection when intercropped with grain legumes. In this paper, we point that this can be attributed to allelopathy, through inhibition of the germination of O. crenata by fenugreek root exudates. The main inhibitory metabolite was isolated and characterized. Allelopathy was demonstrated in different bioassays, by inhibition of O. crenata seeds germination both by growing fenugreek and pea plants together (intercropped), and by application of fenugreek root exudates. Fenugreek root exudates were extracted with organic solvent and fractionated giving several fractions, two of which showed moderate (27%) and strong (54%) inhibition of O. crenata seed germination, respectively. The most active metabolite is a new monosubstituted trioxazonane, characterized by spectroscopic methods as the 2-butyl-[1,4,7,2]trioxazonane and named trigoxazonane.

  20. SPI Conformance Gel Applications in Geothermal Zonal Isolation

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Lyle [Clean Tech Innovations, Bartlesville, OK (United States)

    2017-08-08

    Zonal isolation in geothermal injection and producing wells is important while drilling the wells when highly fractured geothermal zones are encountered and there is a need to keep the fluids from interfering with the drilling operation. Department of Energy’s (DOE) Energy Efficiency and Renewable Energy (EERE) objectives are to advance technologies to make it more cost effective to develop, produce, and monitor geothermal reservoirs and produce geothermal energy. Thus, zonal isolation is critical to well cost, reservoir evaluation and operations. Traditional cementing off of the lost circulation or thief zones during drilling is often done to stem the drilling mud losses. This is an expensive and generally unsuccessful technique losing the potential of the remaining fracture system. Selective placement of strong SPI gels into only the offending fractures can maintain and even improve operational efficiency and resource life. The SPI gel system is a unique silicate based gel system that offers a promising solution to thief zones and conformance problems with water and CO2 floods and potentially geothermal operations. This gel system remains a low viscosity fluid until an initiator (either internal such as an additive or external such as CO2) triggers gelation. This is a clear improvement over current mechanical methods of using packers, plugs, liners and cementing technologies that often severely damage the highly fractured area that is isolated. In the SPI gels, the initiator sets up the fluid into a water-like (not a precipitate) gel and when the isolated zone needs to be reopened, the SPI gel may be removed with an alkaline solution without formation damage occurring. In addition, the SPI gel in commercial quantities is expected to be less expensive than competing mechanical systems and has unique deep placement possibilities. This project seeks to improve upon the SPI gel integrity by modifying the various components to impart temperature stability for use in

  1. Quantitative and qualitative effects of phosphorus on extracts and exudates of sudangrass roots in relation to vesicular-arbuscular mycorrhiza formation.

    Science.gov (United States)

    Schwab, S M; Menge, J A; Leonard, R T

    1983-11-01

    A comparison was made of water-soluble root exudates and extracts of Sorghum vulgare Pers. grown under two levels of P nutrition. An increase in P nutrition significantly decreased the concentration of carbohydrates, carboxylic acids, and amino acids in exudates, and decreased the concentration of carboxylic acids in extracts. Higher P did not affect the relative proportions of specific carboxylic acids and had little effect on proportions of specific amino acids in both extracts and exudates. Phosphorus amendment resulted in an increase in the relative proportion of arabinose and a decrease in the proportion of fructose in exudates, but did not have a large effect on the proportion of individual sugars in extracts. The proportions of specific carbohydrates, carboxylic acids, and amino acids varied between exudates and extracts. Therefore, the quantity and composition of root extracts may not be a reliable predictor of the availability of substrate for symbiotic vesicular-arbuscular mycorrhizal fungi. Comparisons of the rate of leakage of compounds from roots with the growth rate of vesicular-arbuscular mycorrhizal fungi suggest that the fungus must either be capable of using a variety of organic substrates for growth, or be capable of inducing a much higher rate of movement of specific organic compounds across root cell membranes than occurs through passive exudation as measured in this study.

  2. The performance of gel technetium-99m generator

    International Nuclear Information System (INIS)

    Liu Yishu

    2004-01-01

    Technetium-99m, as one of the important radionuclides in nuclear medical science, has been widely used for diseases diagnosis in both developed and developing countries for many years. Technetium-99m can be obtained from both fission-type and gel-type Tc-99m generator. Fission-type generator was prepared by Molybdenum-99 separated from fission products of uranium-235 and gel-type was prepared by irradiating nature MoO 3 in reactor, and a series of chemical and physical processes. This paper briefly describes the manufacturing technical process of gel-type Technetium-99 generator, including the preparation of target containing nature MoO 3 , the target irradiation in reactor, gel preparation, gel filtration and drying, dried gel cracking, generator loading and activity calibration of generator. The performances of gel-type Technetium-99m generator, such as elution efficiency, elution profile, the pH, Mo breakthrough, Zirconium content, radiochemical purity, radionuclidic purity, sterility and pyrogencity of eluate, are also expatiated in detail. Comparing with fission-type Technetium-99m generator, the defects of gel-type Technetium-99m generator are enumerated and their overcoming solutions are recommended in this paper. (author)

  3. Antioxidant activity of the exudate from Aloe barbadensis leaves in ...

    African Journals Online (AJOL)

    The effects of the exudate of Aloe barbadensis leaves on oxidative stress and some antioxidant status of streptozotocin induced - diabetic rats were studied. There was significant reduction in scavenging enzymes like superoxide dismutase (SOD) activity and significant increase in signs of oxidative tissue damage, such as ...

  4. Synthesis and Application of Iron Oxide/Silica Gel Nanocomposite for Removal of Sulfur Dyes from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Naser Tavassoli

    2017-03-01

    Full Text Available Background & Aims of the Study: water pollution by synthetic organic dyes is mainly regarded as environmental and ecological critical issues worldwide. In this research, magnetite iron oxide/silica gel nanocomposite (termed as Fe3O4/SG was synthesized chemically and then used as an effective adsorbent for removal of sulfur dyes from aqueous solution. Materials and Methods: The various parameters such as pH, sorbent dosage, initial dye concentration, contact time and dye solution temperature were investigated in a batch system. The equilibrium data were analyzed by Langmuir and Freundlich isotherm models. Results: The experimental data fit well with pseudo-second-order kinetic model (R2≥0.998 and conformed better to Langmuir isotherm model (R2≥0.997. The maximum adsorption capacity for Fe3O4/SG obtained from the Langmuir model was 11.1mg/g. Evaluation of thermodynamic parameters proved that the adsorption process was normally feasible, spontaneous and exothermic. Conclusion: It can be concluded that the Fe3O4/SG can be considered as a cost-effective and an environmental friendly adsorbent for efficient removal of sulfur dyes from aqueous solutions.

  5. Core–shell Au/Ag nanoparticles embedded in silicate sol–gel ...

    Indian Academy of Sciences (India)

    Administrator

    Dedicated to the memory of the late Professor S K Rangarajan. *For correspondence. Core–shell Au/Ag nanoparticles embedded in silicate sol–gel network for sensor .... An immediate colour change was observed for the mixed solution, indicating the dis- persion of metal nanoparticles in the MTMOS sol– gel matrix.

  6. Status of Exudative Pleural Effusion in Adults of South Khorasan Province, Northeast Iran: Pleural Tuberculosis Tending toward Elderly

    Directory of Open Access Journals (Sweden)

    Sayyed Gholam Reza Mortazavi-Moghaddam

    2016-07-01

    Full Text Available The causes and situation of exudative pleural effusion vary from one area to another. A cross-sectional study was conducted on 327 patients with exudative pleural effusion in South Khorasan province (Iran. The patients were older than 12 years and comprised 172 (52.6% males and 155 (47.4% females. The study commenced in 2007 with seven years duration. The Light’s criteria were used to define exudative effusion. Procedures including pleural fluid analysis, microbiological study, pleural biopsy, and systemic investigations were conducted to determine the special cause of pleural effusion. The mean age of the patients was 63.4±18.4 years. Malignancies, tuberculosis, and parapneumonia pleural exudation were diagnosed in 125 (38.2%, 48 (14.7%, and 45 (13.8% cases, respectively. Among malignant effusions, metastasis from lung cancer made 48 (38.4% of the cases. The origin of metastasis was not determined in 44 (35.2% patients. The mean age of patients was not significantly different between malignant (66.9±14.3 years and tuberculosis (63.9±19.7 years cases (P=0.16. The older age of tuberculosis patients could be a new discussion point on the overall impression created on the subject of tuberculosis pleural exudation (TB-PLE occurring in young people.

  7. Extraction of silver by gels of sodium poly-acrylic-polyacrylate acid. Application: elimination of chloride anions; Extraction de l'argent par des gels d'acide polyacrylique-polyacrylate de sodium. Application a l'elimination des ions chlorures

    Energy Technology Data Exchange (ETDEWEB)

    Rifi, E.H. [Universite Ibn-Tofail, Lab. de Synthese Organique et Pocedes d' Extraction, Faculte des Sciences, Kenitra (Morocco); Lakkis, D.; Leroy, J.F.M. [Universite Louis Pasteur, Lab. de Chimie Analytique et Minerale, Ecole Europeenne de Chimie, Polymeres et Materiaux, 67 - Strasbourg (France)

    2005-05-01

    The extraction of silver from diluted aqueous solutions by gels of sodium poly-acrylic-polyacrylate acid was studied. The study of pH variations shows that the extraction is done by cation-cation exchange process. The highest loading of the gel by silver is obtained at R(moles of Ag{sup +} fixed by the gel/moles of -COO(H, Na))=0.75. The silver gel loaded allows the recovery of ions chlorides from the aqueous solutions. (authors)

  8. Production of cerium dioxide microspheres by an internal gelation sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Katalenich, Jeffrey A.

    2017-03-27

    An internal gelation sol-gel technique was used to prepare cerium dioxide microspheres with uniform diameters near 100 µm. In this process, chilled aqueous solutions containing cerium, hexamethylenetetramine (HMTA), and urea are transformed into a solid gel by heat addition and are subsequently washed, dried, and sintered to produce pure cerium dioxide. Cerous nitrate and ceric ammonium nitrate solutions were compared for their usefulness in microsphere production. Gelation experiments were performed with both cerous nitrate and ceric ammonium nitrate to determine desirable concentrations of cerium, HMTA, and urea in feed solutions as well as the necessary quantity of ammonium hydroxide added to cerium solutions. Analysis of the pH before and after sample gelation was found to provide a quantitative metric for optimal parameter selection along with subjective evaluations of gel qualities. The time necessary for chilled solutions to gel upon inserting into a hot water bath was determined for samples with a variety of parameters and also used to determine desirable formulations for microsphere production. A technique for choosing the optimal mixture of ceric ammonium nitrate, HMTA, and urea was determined using gelation experiments and used to produce microspheres by dispersion of the feed solution into heated silicone oil. Gelled spheres were washed to remove excess reactants and reaction products before being dried and sintered. X-ray diffraction of air-dried microspheres, sintered microspheres, and commercial CeO2 powders indicated that air-dried and sintered spheres were pure CeO2.

  9. Benzo[a]pyrene co-metabolism in the presence of plant root extracts and exudates: Implications for phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Rentz, Jeremy A [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States); Alvarez, Pedro J.J. [Civil and Environmental Engineering, Rice University, Houston, TX 77251 (United States); Schnoor, Jerald L [Civil and Environmental Engineering, University of Iowa, Iowa City, IA 52242 (United States)

    2005-08-15

    Benzo[a]pyrene, a high molecular weight (HMW) polycyclic aromatic hydrocarbon (PAH) was removed from solution by Sphingomonas yanoikuyae JAR02 while growing on root products as a primary carbon and energy source. Plant root extracts of osage orange (Maclura pomifera), hybrid willow (Salix albaxmatsudana), or kou (Cordia subcordata), or plant root exudates of white mulberry (Morus alba) supported 15-20% benzo[a]pyrene removal over 24 h that was similar to a succinate grown culture and an unfed acetonitrile control. No differences were observed between the different root products tested. Mineralization of {sup 14}C-7-benzo[a]pyrene by S. yanoikuyae JAR02 yielded 0.2 to 0.3% {sup 14}CO{sub 2} when grown with plant root products. Collectively, these observations were consistent with field observations of enhanced phytoremediation of HMW PAH and corroborated the hypothesis that co-metabolism may be a plant/microbe interaction important to rhizoremediation. However, degradation and mineralization was much less for root product-exposed cultures than salicylate-induced cultures, and suggested the rhizosphere may not be an optimal environment for HMW PAH degradation by Sphingomonas yanoikuyae JAR02. - Bacterial benzo[a]pyrene cometabolism, a plant-microbe interaction affecting polycyclic aromatic hydrocarbon phytoremediation was demonstrated with Sphingomonas yanoikuyae JAR02 that utilized plant root extracts and exudates as primary substrates.

  10. Sol-gel synthesis of lanthanum-gallate-based ceramic coatings

    International Nuclear Information System (INIS)

    Golubko, N.V.; Kaleva, G.M.; Roginskaya, Yu.E.; Politova, E.D.

    2007-01-01

    Phase-pure (La 0.9 Sr 0.1 )(Ga 0.7 Fe 0.3 )O 3-y and (Sr 1.8 La 0.2 )(GaFe)O 5.1 solid solutions with the perovskite and brownmillerite structures have been prepared from salt solutions by sol-gel processing at temperatures from 570 to 870 K. Ceramic coatings up to 100 μm in thickness have been produced by applying suspensions of the sol-gel powders to various substrates. The structure and microstructure of the ceramic coatings have been studied by X-ray diffraction and scanning electron microscopy [ru

  11. Preliminary study of diffusion effects in Fricke gel dosimeters

    International Nuclear Information System (INIS)

    Quiroga, A.; Vedelago, J.; Valente, M.

    2014-08-01

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, like Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, constraining strongly the time between irradiation and analysis. Due to required integral accuracy levels, special dedicated protocols are implemented with the aim of minimizing signal blurring due to diffusion effects. This work presents dedicated analytic modelling and numerical calculations of diffusion coefficients in Fricke gel radiation sensitive material. Samples are optically analysed by means of visible light transmission measurements capturing images with a Ccd camera provided with a monochromatic 585 nm filter corresponding to the X O-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered in order to assess specific initial conditions further studied by periodical sample image acquisitions. In a first analytic approach, experimental data are fit with linear models in order to achieve a value for the diffusion coefficient. The second approach to the problem consists on a group of computational algorithms based on inverse problem formulation, along with suitable 2D diffusion model capable of estimating diffusion coefficients by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons are performed by introducing an appropriate functional in order to analyse both experimental and numerical values. Solutions to second order diffusion equation are calculated in the framework of a dedicated method that incorporates Finite Element Method. Moreover, optimised solutions can be attained by gradient type minimisation algorithms. Knowledge about diffusion coefficient for Fricke gel radiation detector might be helpful in accounting for effects regarding elapsed time between dosimeter irradiation and further analysis. Hence, corrections might be included

  12. Sol-gel derived antireflective coatings for silicon

    Energy Technology Data Exchange (ETDEWEB)

    Brinker, C J; Harrington, M S

    1981-08-01

    The preparation of TiO2-SiO2 AR coatings, containing from 30 to 95 mol % TiO2, from alkoxide precursor solutions (titanium tetraethoxide and silicon tetraethoxide) by a sol-gel process is presented. The preparation of the solutions is described, which involves the separate partial hydrolysis of one or both alkoxides prior to their mixing (Yoldas, 1980). The solutions are applied to polished, circular (1 and 2 in. diameter) silicon wafers by a spinning process. The coated wafers are successively heated in air at each of the following temperatures: 200, 300, 350, 400, and 450 C, and optical measurements are performed on them after each heat treatment. The durability of 90 and 95% TiO2 coatings is evaluated in both acidic and basic environments, and reflectivity, film thickness, and refractive index are measured as a function of exposure time. It is shown that sol-gel films applied at 400 C reveal broad regions of antireflectance compared to other titanium-based films.

  13. Energy-Efficient Bioalcohol Recovery by Gel Stripping

    Science.gov (United States)

    Godbole, Rutvik; Ma, Lan; Hedden, Ronald

    2014-03-01

    Design of energy-efficient processes for recovering butanol and ethanol from dilute fermentations is a key challenge facing the biofuels industry due to the high energy consumption of traditional multi-stage distillation processes. Gel stripping is an alternative purification process by which a dilute alcohol is stripped from the fermentation product by passing it through a packed bed containing particles of a selectively absorbent polymeric gel material. The gel must be selective for the alcohol, while swelling to a reasonable degree in dilute alcohol-water mixtures. To accelerate materials optimization, a combinatorial approach is taken to screen a matrix of copolymer gels having orthogonal gradients in crosslinker concentration and hydrophilicity. Using a combination of swelling in pure solvents, the selectivity and distribution coefficients of alcohols in the gels can be predicted based upon multi-component extensions of Flory-Rehner theory. Predictions can be validated by measuring swelling in water/alcohol mixtures and conducting h HPLC analysis of the external liquid. 95% + removal of butanol from dilute aqueous solutions has been demonstrated, and a mathematical model of the unsteady-state gel stripping process has been developed. NSF CMMI Award 1335082.

  14. Brilliant molecular nanocrystals emerging from sol-gel thin films: towards a new generation of fluorescent biochips

    International Nuclear Information System (INIS)

    Dubuisson, E; Monnier, V; Sanz-Menez, N; Ibanez, A; Boury, B; Usson, Y; Pansu, R B

    2009-01-01

    To develop highly sensitive biosensors, we made directly available to biological aqueous solutions organic nanocrystals previously grown in the pores of sol-gel films. Through the controlled dissolution of the sol-gel surface, we obtained emerging nanocrystals that remained strongly anchored to the sol-gel coating for good mechanical stability of the final sensing device. We demonstrated that in the presence of a solution of DNA functionalized with a molecular probe, the nanocrystal fluorescence is strongly quenched by Foerster resonance energy transfer thus opening the way towards very sensitive fluorescent biosensors through biomolecules grafted onto fluorescent nanocrystals. Finally, this controlled dissolution, involving weak concentrated NaOH solution, is a generic process that can be used for the thinning of any kind of sol-gel layer.

  15. Root exudation and root development of lettuce (Lactuca sativa L. cv. Tizian) as affected by different soils.

    Science.gov (United States)

    Neumann, G; Bott, S; Ohler, M A; Mock, H-P; Lippmann, R; Grosch, R; Smalla, K

    2014-01-01

    Development and activity of plant roots exhibit high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for 10 years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian) was grown as a model plant under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes). Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils), root growth characteristics (root length, fine root development) as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue). The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes.

  16. Root exudation and root development of lettuce (Lactuca sativa L.cv. Tizian as affected by different soils

    Directory of Open Access Journals (Sweden)

    Günter eNeumann

    2014-01-01

    Full Text Available Development and activity of plant roots exhibits high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for ten years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian was used as a model plant, grown under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes. Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils, root growth characteristics (root length, fine root development as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue. The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes.

  17. Root exudation and root development of lettuce (Lactuca sativa L. cv. Tizian) as affected by different soils

    Science.gov (United States)

    Neumann, G.; Bott, S.; Ohler, M. A.; Mock, H.-P.; Lippmann, R.; Grosch, R.; Smalla, K.

    2014-01-01

    Development and activity of plant roots exhibit high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for 10 years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian) was grown as a model plant under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes). Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils), root growth characteristics (root length, fine root development) as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue). The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes. PMID:24478764

  18. Rhizoctonia solani and Bacterial Inoculants Stimulate Root Exudation of Antifungal Compounds in Lettuce in a Soil-Type Specific Manner

    Directory of Open Access Journals (Sweden)

    Saskia Windisch

    2017-06-01

    Full Text Available Previous studies conducted on a unique field site comprising three contrasting soils (diluvial sand DS, alluvial loam AL, loess loam LL under identical cropping history, demonstrated soil type-dependent differences in biocontrol efficiency against Rhizoctonia solani-induced bottom rot disease in lettuce by two bacterial inoculants (Pseudomonas jessenii RU47 and Serratia plymuthica 3Re-4-18. Disease severity declined in the order DS > AL > LL. These differences were confirmed under controlled conditions, using the same soils in minirhizotron experiments. Gas chromatography-mass spectrometry (GC-MS profiling of rhizosphere soil solutions revealed benzoic and lauric acids as antifungal compounds; previously identified in root exudates of lettuce. Pathogen inoculation and pre-inoculation with bacterial inoculants significantly increased the release of antifungal root exudates in a soil type-specific manner; with the highest absolute levels detected on the least-affected LL soil. Soil type-dependent differences were also recorded for the biocontrol effects of the two bacterial inoculants; showing the highest efficiency after double-inoculation on the AL soil. However, this was associated with a reduction of shoot growth and root hair development and a limited micronutrient status of the host plants. Obviously, disease severity and the expression of biocontrol effects are influenced by soil properties with potential impact on reproducibility of practical applications.

  19. Numerical modelling of glass dissolution: gel layer morphology

    Energy Technology Data Exchange (ETDEWEB)

    Devreux, F. E-mail: fd@pmc.polytechnique.fr; Barboux, P

    2001-09-01

    Numerical simulations of glass dissolution are presented. The glass is modelized as a random binary mixture composed of two species representing silica and soluble oxides, such as boron and alkali oxides. The soluble species are dissolved immediately when they are in contact with the solution. For the species which represents silica, one introduces dissolution and condensation probabilities. It is shown that the morphology and the thickness of the surface hydration layer (the gel) are highly dependent on the dissolution model, especially on the parameter which controls the surface tension. Simulations with different glass surface area to solution volume ratio (S/V) show that this experimental parameter has important effects on both the shrinkage and the gel layer thickness.

  20. Formation and rupture of Ca(2+) induced pectin biopolymer gels.

    Science.gov (United States)

    Basak, Rajib; Bandyopadhyay, Ranjini

    2014-10-07

    When calcium salts are added to an aqueous solution of polysaccharide pectin, ionic cross-links form between pectin chains, giving rise to a gel network in dilute solution. In this work, dynamic light scattering (DLS) is employed to study the microscopic dynamics of the fractal aggregates (flocs) that constitute the gels, while rheological measurements are carried out to study the process of gel rupture. As the calcium salt concentration is increased, DLS experiments reveal that the polydispersity of the flocs increase simultaneously with the characteristic relaxation times of the gel network. Above a critical salt concentration, the flocs become interlinked to form a reaction-limited fractal gel network. Rheological studies demonstrate that the limits of the linear rheological response and the critical stresses required to rupture these networks both decrease with the increase in salt concentration. These features indicate that the ion-mediated pectin gels studied here lie in a 'strong link' regime that is characterised by inter-floc links that are stronger than intra-floc links. A scaling analysis of the experimental data presented here demonstrates that the elasticities of the individual fractal flocs exhibit power-law dependences on the added salt concentration. We conclude that when both pectin and salt concentrations are increased, the number of fractal flocs of pectin increases simultaneously with the density of crosslinks, giving rise to very large values of the bulk elastic modulus.

  1. LABORATORY-SCALE PRODUCTION OF ADU GELS BY EXTERNAL GELATION FOR AN INTERMEDIATE HTGR NUCLEAR

    Directory of Open Access Journals (Sweden)

    S Simbolon

    2015-03-01

    Full Text Available LABORATORY-SCALE PRODUCTION OF ADU GELS BY EXTERNAL GELATION FOR AN INTERMEDIATE HTGR NUCLEAR. The The aim of this research is to produce thousands of microsphere ADU (Ammonium Diuranate gels by using external gelation for an intermediate HTGR (High Temperature Gas-cooled Reactor nuclear fuel in laboratory-scale. Microsphere ADU gels were based on sol-solution which was made from a homogeneous mixture of ADUN (Acid Deficient Uranyl Nitrate which was containing uranyl ion in high concentration, a water soluble organic compound PVA (Polyvinyl Alcohol and THFA (Tetrahydrofurfuryl Alcohol. The simple unified home made laboratory experimental machine was developed to replace test tube experiment method which was once used due to a tiny amount of microsphere ADU gels produced. It consists of four main parts: tank filled sol-solution connecting to peristaltic pump and vibrating nozzle, preliminary gelation and gelation column. The machine has successfully converted 150 mL sol-solution into thousands of drops which produced 120 - 130 drops in each minute in steady state in ammonia gas free sector. Preliminary gelation reaction was carried out in ammonia gas sector where drops react with ammonia gas in a bat an eye followed by gelation reaction in column containing ammonia solution 7 M. In ageing process, ADU gels were collected and submerged into a vessel containing ammonia solution which was shaken for 1 hour in a shaker device. Isopropyl alcohol (90% solution was used to wash ADU gels and a digital camera was used to measured spherical form of ADU gels. Diameters in spherical spheroid form were found between 1.8 mm until 2.2 mm. The spherical purity of ADU gels were 10% - 20% others were oblate, prolate spheroid and microsphere which have hugetiny of dimples on the surface.   PRODUKSI GEL ADU SKALA LABORATORIUM DENGAN MENGGUNAKAN GELASI EKSTERNAL UNTUK BAHAN BAKAR ANTARA HTGR. Penelitian ini bertujuan untuk membuat ribuan gel bulat ADU (Ammonium

  2. A Study of Dip-Coatable, High-Capacitance Ion Gel Dielectrics for 3D EWOD Device Fabrication

    Directory of Open Access Journals (Sweden)

    Carlos E. Clement

    2017-01-01

    Full Text Available We present a dip-coatable, high-capacitance ion gel dielectric for scalable fabrication of three-dimensional (3D electrowetting-on-dielectric (EWOD devices such as an n × n liquid prism array. Due to the formation of a nanometer-thick electric double layer (EDL capacitor, an ion gel dielectric offers two to three orders higher specific capacitance (c ≈ 10 μF/cm2 than that of conventional dielectrics such as SiO2. However, the previous spin-coating method used for gel layer deposition poses several issues for 3D EWOD device fabrication, particularly when assembling multiple modules. Not only does the spin-coating process require multiple repetitions per module, but the ion gel layer also comes in risks of damage or contamination due to handling errors caused during assembly. In addition, it was observed that the chemical formulation previously used for the spin-coating method causes the surface defects on the dip-coated gel layers and thus leads to poor EWOD performance. In this paper, we alternatively propose a dip-coating method with modified gel solutions to obtain defect-free, functional ion gel layers without the issues arising from the spin-coating method for 3D device fabrication. A dip-coating approach offers a single-step coating solution with the benefits of simplicity, scalability, and high throughput for deposition of high-capacitance gel layers on non-planar EWOD devices. An ion gel solution was prepared by combining the [EMIM][TFSI] ionic liquid and the [P(VDF-HFP] copolymer at various wt % ratios in acetone solvent. Experimental studies were conducted to fully understand the effects of chemical composition ratios in the gel solution and how varying thicknesses of ion gel and Teflon layers affects EWOD performance. The effectiveness and potentiality of dip-coatable gel layers for 3D EWOD devices have been demonstrated through fabricating 5 × 1 arrayed liquid prisms using a single-step dip-coating method. Each prism module has

  3. Association of exudative age-related macular degeneration with matrix metalloproteinases-2 (-1306 C/T rs243865 gene polymorphism

    Directory of Open Access Journals (Sweden)

    Rasa Liutkeviciene

    2018-01-01

    Full Text Available Purpose: Age-related macular degeneration (AMD is a disease of the macula that significantly affects eyesight and leads to irreversible central vision loss. Recent studies have demonstrated that angiogenesis is the most important mechanism of AMD development. It is associated with extracellular remodeling involving different proteolytic systems, among them matrix metalloproteinases (MMPs, which play an essential role in the etiopathogenesis of AMD. The main objective of the present study was to determine the relationship between exudative AMD and MMP-2 (-1306 C/T rs243865 polymorphism. Methods: The study enrolled 267 patients with exudative AMD and 318 controls. DNA was extracted from peripheral venous blood leukocytes by commercial kits. Genotyping of MMP-2 (-1306 C/T rs243865 was carried out using real-time polymerase chain reaction method. Results: The analysis of MMP-2 (-1306 C/T polymorphism did not reveal any differences in the distribution of CC, CT, and TT genotypes between the exudative AMD and control groups: 58.8%, 31.5% and 9.7% vs. 59.75%, 33.96% and 6.29%, respectively, P = 0.287. When the study population was subdivided into age groups, MMP-2 (-1306 C/T rs243865 CT genotype showed 5.7-fold increased the risk of exudative AMD development compared to CC and TT genotypes together in younger (<65 years males group (P = 0.05. Conclusion: MMP-2 (-1306 C/T polymorphism is associated with exudative AMD development in younger males.

  4. Compost and biochar alter mycorrhization, tomato root exudation and development of Fusarium oxysporum f. sp. lycopersici

    Directory of Open Access Journals (Sweden)

    Adnan eAkhter

    2015-07-01

    Full Text Available Soil amendments like compost and biochar are known to affect soil properties, plant growth as well as soil borne plant pathogens. Complex interactions based on microbial activity and abiotic characteristics are supposed to be responsible for suppressive properties of certain substrates, however, the specific mechanisms of action are still widely unknown. In the present study, the main focus was on the development of the soil borne pathogen, Fusarium oxysporum f.sp. lycopersici (Fol in tomato (Solanum lycopersicum L. and changes in root exudates of tomato plants grown in different soil substrate compositions, such as compost (Comp alone at application rate of 20 % (v/v, and in combination with wood biochar (WB; made from beech wood chips or green waste biochar (GWB, made from garden waste residues at application rate of 3 % (v/v, and/or with additional arbuscular mycorrhizal fungi (AMF. The association of GWB and AMF had a positive effect on tomato plants growth unlike to the plants grown in WB containing soil substrate. The AMF root colonization was not enhanced by the addition of WB or GWB in the soil substrate, though bio-protective effect of mycorrhization was evident in both biochar amended treatments against Fol. Compost and biochars altered root exudates differently, which is evident from variable response of in vitro growth and development of Fol. The microconidia germination was highest under in root exudates from plants grown in the soil containing compost and GWB, whereas root exudates of plants from substrate containing WB suppressed the mycelial growth and development of Fol. In conclusion, the plant growth response and disease suppression in biochar containing substrates with additional AMF was affected by the feedstock type. Moreover, application of compost and biochars in the soil influence the quality and composition of root exudates with respect to their effects on soil-dwelling fungi.

  5. Process for encapsulating active agents obtaining a gel

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.

    2001-01-01

    The present invention relates to a process for encapsulating an active agent in a biopolymer in the form of a gel, comprising the steps of: a) forming a dispersion or solution of the biopolymer in water; and b) adding the active agent to the dispersion or solution obtained in step a); wherein the

  6. Sol-gel Technology and Advanced Electrochemical Energy Storage Materials

    Science.gov (United States)

    Chu, Chung-tse; Zheng, Haixing

    1996-01-01

    Advanced materials play an important role in the development of electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. The sol-gel process is a versatile solution for use in the fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. This processing technique is particularly useful in producing porous materials with high surface area and low density, two of the most desirable characteristics for electrode materials. In addition,the porous surface of gels can be modified chemically to create tailored surface properties, and inorganic/organic micro-composites can be prepared for improved material performance device fabrication. Applications of several sol-gel derived electrode materials in different energy storage devices are illustrated in this paper. V2O5 gels are shown to be a promising cathode material for solid state lithium batteries. Carbon aerogels, amorphous RuO2 gels and sol-gel derived hafnium compounds have been studied as electrode materials for high energy density and high power density electrochemical capacitors.

  7. Staining of proteins in gels with Coomassie G-250 without organic solvent and acetic acid.

    Science.gov (United States)

    Lawrence, Ann-Marie; Besir, H Uuml Seyin

    2009-08-14

    In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80 mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staining of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compounds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

  8. Microstructure, chemical composition and mucilage exudation of chia (Salvia hispanica L.) nutlets from Argentina.

    Science.gov (United States)

    Capitani, Marianela I; Ixtaina, Vanesa Y; Nolasco, Susana M; Tomás, Mabel C

    2013-12-01

    The micromorphology and anatomy of nutlets, myxocarpy (mucilage exudation) and mucilage structure of Argentinean chia were described using scanning electron microscopy (SEM). The proximal composition of nutlets and mucilage was also studied. Chia nutlets are made up of a true seed and a pericarp enclosing the seed; they are small, glabrous, elliptic and apically rounded. The pericarp has cuticle, exocarp, mesocarp and bone cells vertically arranged and endocarp. The myxocarpy was carefully recorded by SEM. After 5 min in contact with water, the cuticle of nutlets is broken and the exocarp cell content gradually surrounds the rest of the nutlet. The proximal composition of chia nutlets was studied; fat is the major component (327 ± 8.0 g kg(-1)) followed by protein (293 ± 4.0 g kg(-1)) and fiber (276 ± 1.0 g kg(-1)). Extractions of chia nutlets with water at room temperature yielded 38 ± 1.0 g kg(-1) (dry basis) of mucilage. The fresh mucilage structure was similar to a network of open pores. The freeze-dried crude mucilage contained more ash, residual fat and protein than commercial guar and locust bean gum. The solubility of 10.0 g L(-1) w/v solution of chia freeze-dried crude mucilage in water increased with temperature, being maximal at 60 °C (870 g kg(-1)). The results obtained show a fast exudation of chia mucilage when nutlets are in contact with water. The freeze-dried crude mucilage hydrates easily in water, even at low temperatures. Chia nutlets have mucilaginous substances, with interesting functional properties from a technological and physiological point of view. © 2013 Society of Chemical Industry.

  9. Assessment of a gel-type chelating preparation containing 1-hydroxyethylidene-1, 1-bisphosphonate.

    Science.gov (United States)

    Girard, S; Paqué, F; Badertscher, M; Sener, B; Zehnder, M

    2005-11-01

    To test an aqueous gel containing 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) regarding its interactions with sodium hypochlorite, its calcium binding capacity, and its potential in preventing the formation of a smear layer when used in conjunction with rotary root canal preparation. The experimental aqueous gel consisted of (w/v) 2% alginate, 3% aerosil, 10% Tween 80 and 18% HEBP. Interactions of gel components with hypochlorite were assessed using iodometric titration and monochromatic ultraviolet spectrometry. Two commercial paste-type chelators containing ethylenediaminetetraacetic acid (EDTA) and peroxide (RC-Prep and Glyde) served as controls. Calcium-binding capacities were measured in mixtures with a Ca2+ standard solution buffered at pH 10 using a calcium-selective measuring chain. Finally, root canals of 16 extracted single-rooted premolars per group were instrumented using ProFile instruments dipped in the experimental gel, RC-Prep, or nothing. Additionally, canals were rinsed with 10 mL of a 1% NaOCl solution during/after preparation. Smear scores in instrumented teeth were monitored using scanning electron microscopy. None of the experimental gel components showed short-term interactions with hypochlorite, whilst EDTA, peroxide, RC-Prep and Glyde immediately reduced the hypochlorite in solution. The experimental gel chelated 30 mg Ca2+ g-1, compared with 16 mg Ca2+ g-1 and 11 mg Ca2+ g-1 chelated by RC-Prep and Glyde respectively. Smear scores obtained with the experimental gel were significantly (P<0.05) lower than with RC-Prep in coronal and middle root thirds, whilst no differences were observed in apical root thirds. Under the conditions of this study, an HEBP gel appeared advantageous over currently available products.

  10. A simple gel electrophoresis method for separating polyhedral gold nanoparticles

    Science.gov (United States)

    Kim, Suhee; Lee, Hye Jin

    2015-07-01

    In this paper, a simple approach to separate differently shaped and sized polyhedral gold nanoparticles (NPs) within colloidal solutions via gel electrophoresis is described. Gel running parameters for separating efficiently gold NPs including gel composition, added surfactant types and applied voltage were investigated. The plasmonic properties and physical structure of the separated NPs extracted from the gel matrix were then investigated using transmission electron microscopy (TEM) and UV-vis spectrophotometry respectively. Data analysis revealed that gel electrophoresis conditions of a 1.5 % agarose gel with 0.1 % sodium dodecyl sulfate (SDS) surfactant under an applied voltage of 100 V resulted in the selective isolation of ~ 50 nm polyhedral shaped gold nanoparticles. Further efforts are underway to apply the method to purify biomolecule-conjugated polyhedral Au NPs that can be readily used for NP-enhanced biosensing platforms.

  11. Low strigolactone root exudation: a novel mechanism of broomrape (Orobanche and Phelipanche spp.) resistance available for faba bean breeding.

    Science.gov (United States)

    Fernández-Aparicio, Mónica; Kisugi, Takaya; Xie, Xiaonan; Rubiales, Diego; Yoneyama, Koichi

    2014-07-23

    Faba bean yield is severely constrained in the Mediterranean region and Middle East by the parasitic weeds Orobanche crenata, O. foetida, and Phelipanche aegyptiaca. Seed germination of these weeds is triggered upon recognition of host root exudates. Only recently faba bean accessions have been identified with resistance based in low induction of parasitic seed germination, but the underlying mechanism was not identified. Strigolactones are a group of terpenoid lactones involved in the host recognition by parasitic plants. Our LC-MS/MS analysis of root exudates of the susceptible accession Prothabon detected orobanchol, orobanchyl acetate, and a novel germination stimulant. A time course analysis indicated that their concentration increased with plant age. However, low or undetectable amounts of these germination stimulants were detected in root exudates of the resistant lines Quijote and Navio at all plant ages. A time course analysis of seed germination induced by root exudates of each faba bean accession indicated important differences in the ability to stimulate parasitic germination. Results presented here show that resistance to parasitic weeds based on low strigolactone exudation does exist within faba bean germplasm. Therefore, selection for this trait is feasible in a breeding program. The remarkable fact that low induction of germination is similarly operative against O. crenata, O. foetida, and P. aegyptiaca reinforces the value of this resistance.

  12. Optimization of Large Gel 2D Electrophoresis for Proteomic Studies of Skeletal Muscle

    Science.gov (United States)

    Reed, Patrick W.; Densmore, Allison; Bloch, Robert J.

    2013-01-01

    We describe improved methods for large format, 2-dimensional gel electrophoresis (2-DE) that improve protein solubility and recovery, minimize proteolysis, and reduce the loss of resolution due to contaminants and manipulations of the gels, and thus enhance quantitative analysis of protein spots. Key modifications are: (i) the use of 7M urea + 2 M thiourea, instead of 9M urea, in sample preparation and in the tops of the gel tubes; (ii) standardized deionization of all solutions containing urea with a mixed bed ion exchange resin and removal of urea from the electrode solutions; and (iii) use of a new gel tank and cooling device that eliminate the need to run two separating gels in the SDS dimension. These changes make 2D-GE analysis more reproducible and sensitive, with minimal artifacts. Application of this method to the soluble fraction of muscle tissues reliably resolves ~1800 protein spots in adult human skeletal muscle and over 2800 spots in myotubes. PMID:22589104

  13. ENTIRELY AQUEOUS SOLUTION-GEL ROUTE FOR THE PREPARATION OF ZIRCONIUM CARBIDE, HAFNIUM CARBIDE AND THEIR TERNARY CARBIDE POWDERS

    Directory of Open Access Journals (Sweden)

    Zhang Changrui

    2016-07-01

    Full Text Available An entirely aqueous solution-gel route has been developed for the synthesis of zirconium carbide, hafnium carbide and their ternary carbide powders. Zirconium oxychloride (ZrOCl₂.8H₂O, malic acid (MA and ethylene glycol (EG were dissolved in water to form the aqueous zirconium carbide precursor. Afterwards, this aqueous precursor was gelled and transformed into zirconium carbide at a relatively low temperature (1200 °C for achieving an intimate mixing of the intermediate products. Hafnium and the ternary carbide powders were also synthesized via the same aqueous route. All the zirconium, hafnium and ternary carbide powders exhibited a particle size of ∼100 nm.

  14. Association of systemic risk factors with the severity of retinal hard exudates in a north Indian population with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Sachdev N

    2010-01-01

    Full Text Available Background: The various risk factors for diabetic retinopathy and its spectrum are still poorly understood in the Indian population. Aims: To study the association of various systemic risk factors with retinal hard exudates in type 2 diabetic north Indian patients and to measure the incidence of dyslipidemia in them. Settings and Design: A tertiary-hospital-based cross-sectional study. Materials and Methods: An observational case-study which included 180 type 2 diabetic patients (180 eyes of nonproliferative diabetic retinopathy (NPDR with clinically significant macular edema (CSME. In these patients the retinal hard exudates were graded on a central 500 fundus picture using modified Airlie House classification and divided into three groups of absent or minimal hard exudates (Group 1, hard exudates present (Group 2 and prominent hard exudates (Group 3. Their association with various risk factors, namely the age of onset of diabetes and its duration, gender, insulin therapy, and various systemic parameters like hypertension, blood hemoglobin, glycosylated hemoglobin, serum (s. creatinine levels, 24-h proteinuria and complete lipid profile including total s. cholesterol, low-density lipoprotein cholesterol (LDL, high-density lipoprotein cholesterol (HDL, very low-density lipoprotein cholesterol (VLDL and s. triglyceride (TG was studied. The incidence of dyslipidemia was also calculated among these groups of patients. Statistical Analysis: ANOVA test, linear regression analysis and Spearman′s correlation test. Results: On univariate analysis, the retinal hard exudates were significantly associated with s. creatinine (P=0.016, systolic blood pressure (P=0.014, s. cholesterol (P < 0.001, s. LDL (P=0.008 and s. TG (P=0.013 levels. While on linear regression analysis, s. cholesterol (P < 0.001 and s. LDL cholesterol (P=0.028 were found to be independent risk factors affecting the density of retinal hard exudates. On Spearman′s correlation test, the

  15. Growth and micro-topographical studies of gel grown cholesterol ...

    Indian Academy of Sciences (India)

    Unknown

    The single test-tube diffusion method (Henisch 1988) was employed ... solution was filtered and kept in a clean flask. ... vents in the gel will enhance the growth of crystals in the ... Results. 3.1 Effect of different solvents. In the first case the stock solution was mixed with acetone ... A 0⋅5% (w/v) solution of cholesterol in ace-.

  16. Effect of soil water content on spatial distribution of root exudates and mucilage in the rhizosphere

    Science.gov (United States)

    Holz, Maire; Zarebanadkouki, Mohsen; Kuzyakov, Yakov; Carminati, Andrea

    2016-04-01

    Water and nutrients are expected to become the major factors limiting food production. Plant roots employ various mechanisms to increase the access to these limited soil resources. Low molecular root exudates released into the rhizosphere increase nutrient availability, while mucilage improves water availability under low moisture conditions. However, studies on the spatial distribution and quantification of exudates in soil are scarce. Our aim was therefore to quantify and visualize root exudates and mucilage distribution around growing roots using neutron radiography and 14C imaging at different levels of water stress. Maize plants were grown in rhizotrons filled with a silty soil and were exposed to varying soil conditions, from optimal to dry. Mucilage distribution around the roots was estimated from the profiles of water content in the rhizosphere - note that mucilage increases the soil water content. The profiles of water content around different root types and root ages were measured with neutron radiography. Rhizosphere extension was approx. 0.7 mm and did not differ between wet and dry treatments. However, water content (i.e. mucilage concentration) in the rhizosphere of plants grown in dry soils was higher than for plants grown under optimal conditions. This effect was particularly pronounced near the tips of lateral roots. The higher water contents near the root are explained as the water retained by mucilage. 14C imaging of root after 14CO2 labeling of shoots (Pausch and Kuzyakov 2011) was used to estimate the distribution of all rhizodeposits. Two days after labelling, 14C distribution was measured using phosphor-imaging. To quantify 14C in the rhizosphere a calibration was carried out by adding given amounts of 14C-glucose to soil. Plants grown in wet soil transported a higher percentage of 14C to the roots (14Croot/14Cshoot), compared to plants grown under dry conditions (46 vs. 36 %). However, the percentage of 14C allocated from roots to

  17. Vascular Endothelial Growth Factor Concentration in Chronic Subdural Hematoma Fluid Is Related to Computed Tomography Appearance and Exudation Rate

    Science.gov (United States)

    Weigel, Ralf; Hohenstein, Axel

    2014-01-01

    Abstract Chronic subdural hematoma (CSH) is characterized by a net increase of volume over time. Major underlying mechanisms appear to be hemorrhagic episodes and a continuous exudation, which may be studied using labeled proteins to yield an exudation rate in a given patient. We tested the hypothesis that the concentration of vascular endothelial growth factor (VEGF) in hematoma fluid correlates with the rate of exudation. Concentration of VEGF was determined in 51 consecutive patients with CSH by the sandwich immune enzyme-linked immunosorbent assay technique. Mean values were correlated with exudation rates taken from the literature according to the appearance of CSH on computed tomography (CT) images. The CT appearance of each CSH was classified as hypodense, isodense, hyperdense, or mixed density. Mean VEGF concentration was highest in mixed-density hematomas (22,403±4173 pg/mL; mean±standard error of the mean; n=27), followed by isodense (9715±1287 pg/mL; n=9) and hypodense (5955±610 pg/mL; n=18) hematomas. Only 1 patient with hyperdense hematoma fulfilled the inclusion criteria, and the concentration of VEGF found in this patient was 24,200 pg/mL. There was a statistically significant correlation between VEGF concentrations and exudation rates in the four classes of CT appearance (r=0.98). The current report is the first to suggest a pathophysiological link between the VEGF concentration and the exudation rate underlying the steady increase of hematoma volume and CT appearance.With this finding, the current report adds another piece of evidence in favor of the pathophysiological role of VEGF in the development of CSH, including mechanisms contributing to hematoma growth and CT appearance. PMID:24245657

  18. A case of apathetic hyperthyroidism with exudative low SAAG ascites

    Directory of Open Access Journals (Sweden)

    Seyed Masood Tabib

    2009-12-01

    In this case report, we present a 73-year-old man who was referred to us with anorexia, severe weight loss, anemia, lower limbs pitting edema, and also exudative, low SAAG ascites. Extensive work up revealed that these constellation of signs & symptoms were consequent to decompensation of his chronic right-sided heart failure resulting from apathetic hyperthyroidism.

  19. New phenolic esters from the resinous exudate of Haplopappus taeda.

    Science.gov (United States)

    Faini, Francesca; Labbé, Cecilia; Torres, René; Rodilla, Jesús M; Silva, Lucía; Delle Monache, Franco

    2007-12-01

    Two new phenolic esters 9-trans-p-coumaroyloxy-alpha-terpineol (1) and 7-trans-p-coumaroyloxy-taedol (2), both endowed with free radical scavenger activity and cleroda-3,13 (E)-dien-15,18-diol (3) for which a cis stereochemistry at the decalin junction was found, were isolated from the resinous exudate from Haplopappus taeda upper parts.

  20. Role of blind closed pleural biopsy in the managment of pleural exudates.

    Science.gov (United States)

    Pereyra, Marco F; San-José, Esther; Ferreiro, Lucía; Golpe, Antonio; Antúnez, José; González-Barcala, Francisco-Javier; Abdulkader, Ihab; Álvarez-Dobaño, José M; Rodríguez-Núñez, Nuria; Valdés, Luis

    2013-01-01

    The performance of blind closed pleural biopsy (BCPB) in the study of pleural exudates is controversial. To assess the diagnostic yield of BCPB in clinical practice and its role in the study of pleural exudates. Data were retrospectively collected on all patients who underwent BCPB performed between January 1999 and December 2011. A total of 658 BCPBs were performed on 575 patients. Pleural tissue was obtained in 590 (89.7%) of the biopsies. A malignant pleural effusion was found in 35% of patients. The cytology and the BCPB were positive in 69.2% and 59.2% of the patients, respectively. Of the patients with negative cytology, 21 had a positive BCPB (diagnostic improvement, 15%), which would have avoided one pleuroscopy for every seven BCPBs that were performed. Of the 113 patients with a tuberculous effusion, granulomas were observed in 87 and the Lowenstein culture was positive in an additional 17 (sensitivity 92%). The overall sensitivity was 33.9%, with a specificity and positive predictive value of 100%, and a negative predictive value of 71%. Complications were recorded in 14.4% of patients (pneumothorax 9.4%; chest pain 5.6%; vasovagal reaction, 4.1%; biopsy of another organ 0.5%). BCPB still has a significant role in the study of a pleural exudate. If an image-guided technique is unavailable, it seems reasonable to perform BCPB before resorting to a pleuroscopy. These results support BCPB as a relatively safe technique.

  1. Lactoferrin, myeloperoxidase, lysozyme and eosinophil cationic protein in exudate in delayed type hypersensitivity

    DEFF Research Database (Denmark)

    Lerche, A; Bisgaard, H; Christensen, J D

    1988-01-01

    allergic patients with nickel challenge in the chamber medium showed a time-dependent increase of mononuclear cells, eosinophils and basophils and a concomitant decrease of polymorphonuclear granulocytes, characteristic of a combined specific and unspecific inflammation. The morphology of the exudate...... in contact allergic patients exposed to nickel showed a dominance of polymorphonuclear granulocytes throughout the study period, while mononuclear cells, eosinophils and basophils were detected at a much lower quantity and with a considerable delay. Further, we studied the kinetics of the leucocyte granule...... proteins: lactoferrin, myeloperoxidase, lysozyme and eosinophil cationic protein in exudate fluid in a parallel test. A significant higher flux was found for all during the second day of allergen exposure compared to contact allergic patients without allergen challenge as well as normal volunteers...

  2. Preliminary study of diffusion effects in Fricke gel dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Quiroga, A. [Centro de Investigacion y Estudios de Matematica de Cordoba, Oficina 318 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Vedelago, J. [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina); Valente, M., E-mail: aiquiroga@famaf.unc.edu [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Diffusion of ferric ions in ferrous sulfate (Fricke) gels represents one of the main drawbacks of some radiation detectors, like Fricke gel dosimeters. In practice, this disadvantage can be overcome by prompt dosimeter analysis, constraining strongly the time between irradiation and analysis. Due to required integral accuracy levels, special dedicated protocols are implemented with the aim of minimizing signal blurring due to diffusion effects. This work presents dedicated analytic modelling and numerical calculations of diffusion coefficients in Fricke gel radiation sensitive material. Samples are optically analysed by means of visible light transmission measurements capturing images with a Ccd camera provided with a monochromatic 585 nm filter corresponding to the X O-infused Fricke solution absorbance peak. Dose distributions in Fricke gels are suitably delivered in order to assess specific initial conditions further studied by periodical sample image acquisitions. In a first analytic approach, experimental data are fit with linear models in order to achieve a value for the diffusion coefficient. The second approach to the problem consists on a group of computational algorithms based on inverse problem formulation, along with suitable 2D diffusion model capable of estimating diffusion coefficients by fitting the obtained algorithm numerical solutions with the corresponding experimental data. Comparisons are performed by introducing an appropriate functional in order to analyse both experimental and numerical values. Solutions to second order diffusion equation are calculated in the framework of a dedicated method that incorporates Finite Element Method. Moreover, optimised solutions can be attained by gradient type minimisation algorithms. Knowledge about diffusion coefficient for Fricke gel radiation detector might be helpful in accounting for effects regarding elapsed time between dosimeter irradiation and further analysis. Hence, corrections might be included

  3. Sol-gel encapsulation for controlled drug release and biosensing

    Science.gov (United States)

    Fang, Jonathan

    The main focus of this dissertation is to investigate the use of sol-gel encapsulation of biomolecules for controlled drug release and biosensing. Controlled drug release has advantages over conventional therapies in that it maintains a constant, therapeutic drug level in the body for prolonged periods of time. The anti-hypertensive drug Captopril was encapsulated in sol-gel materials of various forms, such as silica xerogels and nanoparticles. The primary objective was to show that sol-gel silica materials are promising drug carriers for controlled release by releasing Captopril at a release rate that is within a therapeutic range. We were able to demonstrate desired release for over a week from Captopril-doped silica xerogels and overall release from Captopril-doped silica nanoparticles. As an aside, the antibiotic Vancomycin was also encapsulated in these porous silica nanoparticles and desired release was obtained for several days in-vitro. The second part of the dissertation focuses on immobilizing antibodies and proteins in sol-gel to detect various analytes, such as hormones and amino acids. Sol-gel competitive immunoassays on antibody-doped silica xerogels were used for hormone detection. Calibration for insulin and C-peptide in standard solutions was obtained in the nM range. In addition, NASA-Ames is also interested in developing a reagentless biosensor using bacterial periplasmic binding proteins (bPBPs) to detect specific biomarkers, such as amino acids and phosphate. These bPBPs were doubly labeled with two different fluorophores and encapsulated in silica xerogels. Ligand-binding experiments were performed on the bPBPs in solution and in sol-gel. Ligand-binding was monitored by fluorescence resonance energy transfer (FRET) between the two fluorophores on the bPBP. Titration data show that one bPBP has retained its ligand-binding properties in sol-gel.

  4. Tetragonal-cubic phase boundary in nanocrystalline ZrO2-Y2O3 solid solutions synthesized by gel-combustion

    International Nuclear Information System (INIS)

    Fabregas, Ismael O.; Craievich, Aldo F.; Fantini, Marcia C.A.; Millen, Ricardo P.; Temperini, Marcia L.A.; Lamas, Diego G.

    2011-01-01

    Research highlights: → Gel-combustion synthesis yields compositionally homogeneous, single-phased ZrO 2 -Y 2 O 3 nanopowders, that exhibit the presence at room temperature of three different phases depending on Y 2 O 3 content, namely two tetragonal forms (t' and t'') and the cubic phase. → Phase identification can be achieved by synchrotron XPD (SXPD) and Raman spectroscopy since the tetragonal forms and the cubic phase can be distinguished by these techniques. → The crystallographic features of ZrO 2 -Y 2 O 3 nanopowders were determined by SXPD. They are similar to those reported by Yashima and coworkers for compositionally homogeneous materials containing larger (micro)crystals. However, the lattice parameters are slightly different and the axial ratios c/a of our t' samples are smaller than those reported by these authors. → Compositional t'/t'' and t''/cubic phase boundaries are located at (9 ± 1) and (10.5 ± 0.5) mol% Y 2 O 3 , respectively. → For the whole series of nanocrystalline ZrO 2 -Y 2 O 3 solid solutions studied in the present work, no evidences of the presence of a mixture of phases - as reported by Yashima and coworkers for microcrystalline solid solutions - were detected. - Abstract: By means of synchrotron X-ray powder diffraction (SXPD) and Raman spectroscopy, we have detected, in a series of nanocrystalline and compositionally homogeneous ZrO 2 -Y 2 O 3 solid solutions, the presence at room temperature of three different phases depending on Y 2 O 3 content, namely two tetragonal forms and the cubic phase. The studied materials, with average crystallite sizes within the range 7-10 nm, were synthesized by a nitrate-citrate gel-combustion process. The crystal structure of these phases was also investigated by SXPD. The results presented here indicate that the studied nanocrystalline ZrO 2 -Y 2 O 3 solid solutions exhibit the same phases reported in the literature for compositionally homogeneous materials containing larger (micro

  5. Characterisation of a new alkoxide sol-gel hydroxyapatite

    International Nuclear Information System (INIS)

    Green, D.D.; Kannangara, G.S.K.; Milev, A.; Ben-Nissan, B.

    1999-01-01

    Hydroxyapatite (HAp) coatings have been used to promote bone growth and fixation towards implant surfaces to encourage faster recovery times for the recipient. Current coating processing techniques, capable of producing thin HAp layers are pulsed-laser deposition and sputtering (high-temperature processing). Other technologies are in vitro methods, electrodeposition and sol-gel, due to the fact that these techniques utilise lower processing temperatures they avoid structural instabilities of HAp at elevated temperatures. The term sol-gel encompasses any process of producing ceramic materials (single and mixed oxides, as well as non-oxides e.g. nitrides) from solutions. The sol-gel process was first identified by Ebelman, and has been used to produce ceramic powders, coatings, and bulk materials including glasses. The implementation of a sol-gel methodology enables increased stoichiometry and homogeneity, while having the ability to coat complex shapes. Sol-gel hydroxyapatite reported by Chai et al. employed tri ethyl phosphite [ P(OEt) 3 ] as the staring phosphorus alkoxide precursor, whereby it was established that in order to obtain monophasic hydroxyapatite upon firing there must be a 24 hour ripening period. The ripening period was determined to be an equilibrium step whereby the equilibrium intermediate phase lied in favour of a diethyl phosphite arrangement (species) within the sol. Therefore, the work here under taken was to produce hydroxyapatite using diethyl phosphite [HOP(OEt) 2 ] as a starting alkoxide precursor with a final aim to reduce or eliminate the ageing period as observed by Chai et al in P(OEt) 3 solutions

  6. Sol-gel process for thermal reactor fuel fabrication

    International Nuclear Information System (INIS)

    Mukerjee, S.K.

    2008-01-01

    Full text: Sol-gel processes have revolutionized conventional ceramic technology by providing extremely fine and uniform powders for the fabrication of ceramics. The use of this technology for nuclear fuel fabrication has also been explored in many countries. Unlike the conventional sol-gel process, sol-gel process for nuclear fuels tries to eliminate the preparation of powders in view of the toxic nature of the powders particularly those of plutonium and 233 U. The elimination of powder handling thus makes this process more readily amenable for use in glove boxes or for remote handling. In this process, the first step is the preparation of microspheres of the fuel material from a solution which is then followed by vibro-compaction of these microspheres of different sizes to obtain the required smear density of fuel inside a pin. The maximum achievable packing density of 92 % makes it suitable for fast reactors only. With a view to extend the applicability of sol-gel process for thermal reactor fuel fabrication the concept of converting the gel microspheres derived from sol-gel process, to the pellets, has been under investigation for several years. The unique feature of this process is that it combines the advantages of sol-gel process for the preparation of fuel oxide gel microspheres of reproducible quality with proven irradiation behavior of the pellet fuel. One of the important pre-requisite for the success of this process is the preparation of soft oxide gel microspheres suitable for conversion to dense pellets free from berry structure. Studies on the internal gelation process, one of the many variants of sol-gel process, for obtaining soft oxide gel microspheres suitable for gel pelletisation is now under investigation at BARC. Some of the recent findings related to Sol-Gel Microsphere Pelletisation (SGMP) in urania-plutonia and thoria-urania systems will be presented

  7. How do monomeric components of a polymer gel dosimeter respond to ionising radiation: A steady-state radiolysis towards preparation of a 3D polymer gel dosimeter

    International Nuclear Information System (INIS)

    Kozicki, Marek

    2011-01-01

    Ionising radiation-induced reactions of aqueous single monomer solutions and mixtures of poly(ethylene glycol) diacrylate (PEGDA) and N,N'-methylenebisacrylamide (Bis) in a steady-state condition are presented below and above gelation doses in order to highlight reactions in irradiated 3D polymer gel dosimeters, which are assigned for radiotherapy dosimetry. Both monomers are shown to undergo radical polymerisation and cross-linking, which result in the measured increase in molecular weight and radius of gyration of the formed polydisperse polymer coils. The formation of nanogels was also observed for Bis solutions at a low concentration. In the case of PEGDA-Bis mixtures, co-polymerisation is suggested as well. At a sufficiently high radiation dose, the formation of a polymer network was observed for both monomers and their mixture. For this reason a sol-gel analysis for PEGDA and Bis was performed gravimetrically and a proposition of an alternative to this method employing a nuclear magnetic resonance technique is made. The two monomers were used for preparation of 3D polymer gel dosimeters having the acronyms PABIG and PABIG nx . The latter is presented for the first time in this work and is a type of the formerly established PABIG polymer gel dosimeter. The elementary characteristics of the new composition are presented, underlining the ease of its preparation, low dose threshold, and slightly increased sensitivity but lower quasi-linear range of dose response in comparison to PABIG. - Highlights: → Steady-state radiolysis of Bis, PEGDA and Bis-PEGDA is examined. → High Mw products are formed at low absorbed doses. → Formation of Bis nanogels is likely; PEGDA solutions form hydrogels. → NMR technique can be used for sol-gel analysis. → Features of 3D polymer gel dosimeters made from PEGDA and Bis are shown.

  8. Determination of cadmium with 6-bromo-2-benzothiazolylazo-2-naphthol gel

    International Nuclear Information System (INIS)

    Lee, Yong-Keun; Ueno, Keihei.

    1980-01-01

    A simple and rapid semiquantitative procedure has been developed for the determination of sub-ppm level of cadmium in environmental aquatic samples by using an analytical micro-column packed with reagent gel beads. Reagent gel beads were prepared by treating the cross-linked polystyrene beads (2% divinylbenzene, (70 -- 100) mesh in dry condition) with 0.02% chlorobenzene solution of 6-bromo-2-benzothiazolylazo-2-naphthol (BTAN) for 24 h at room temperature. The gel beads were packed into a glass column (2.5 mm bore, 120 mm length). When a sample solution containing cadmium, buffered to pH 10 with Clark-Lubs buffer, was passed through the BTAN gel column at a flow rate of 0.2 ml/min, the original pink color of the reagent gel turned to red-violet from the up-stream of the column. As the length of colored band was proportional to the total amount of cadmium in the sample solution passed through the column, the concentration of cadmium can be determined from the calibration line which had been prepared by using the standard solution. Cadmium ion at (0.05 -- 0.1)ppm and (0.2 -- 0.5)ppm levels could be determined with +-10% and +-5% relative errors, respectively. Of the foreign metals, 40-fold excess of Cr(VI), 20-fold excess of Al and Ni, 10-fold excess of Co(II), Hg(II), Fe(III) and Ag, and 5-fold excess of Cu(II) could be masked with Zincon, Tiron, thiourea and sodium fluoride. As for Zn(II), interferences could be masked up to identical amount with Cd with Zincon. This method was successfully applied to the analysis of cadmium in environmental aquatic samples. (author)

  9. The diagnostic value of pleural effusion ferritin and the ratio of it to serum ferritin in differentiating exudates from transudates

    International Nuclear Information System (INIS)

    Yang Liu; Liu Junfeng; Yu Jiuru; Ju Ping; Ke Caiming

    2003-01-01

    To explore the diagnostic value of measuring the level of ferritin in pleural and peritoneal effusion for differentiating exudates from transudates, 128 effusion samples were initially detected for differentiating exudates from transudates by traditional method and Light's criteria. Ferritin in the effusions and serum ferritin were detected simultaneously, and the ratio of effusion ferritin (P Ft ) to serum ferritin (S Ft ) was counted. Based on the clinical data, the samples were divided into four groups and P Ft and P Ft /S Ft were compared. At the same time, the sensitivity and specificity of P Ft and P Ft /S Ft in differentiating exudates from transudates were compared with traditional method and Light's criteria. The results showed that in the groups of tuberculous pleurisy, non-tuberculous, benign pleurisy, and malignant tumor, the concentration of Ft in the effusions was significantly higher than that in the group of congestive heart failure and cirrhosis; and the Ft in exudates was significantly higher than that in transudates (P 0.05). If the cut-off value was set up for Ft in the effusion as 100 μg/L and P Ft /S Ft ratio as 0.5, respectively, the differentiating sensitivity and specificity were 94.2% and 87.0%, respectively. Conclusion was that the concentration of P Ft and P Ft /S Ft in exudates are higher than 100 μg/L and 0.5, respectively. On the contrary, they are lower than the cut-off level in transudates. P Ft and P Ft /S Ft have high sensitivity and high specificity in differentiating exudates from transudates, and have great diagnostic value

  10. Thermosetting gels with modulated gelation temperature for ophthalmic use: the rheological and gamma scintigraphic studies.

    Science.gov (United States)

    Wei, Gang; Xu, Hui; Ding, Ping Tian; Li, San Ming; Zheng, Jun Min

    2002-09-18

    For ophthalmic drug delivery, Pluronic F127 solutions have a phase transition temperature too low for them to be instilled into the eye at room temperature. Refrigerator storage is usually required to make administration easier, whereas the potential irritation of cold to the sensitive ocular tissues may result in poor topical bioavailability. The purpose of this study is to develop a thermosetting gel with a suitable phase transition temperature by combining Pluronic analogs and to examine the influence of incorporating mucoadhesive polysaccharide, sodium hyaluronate (HA-Na), on the ocular retention of the gel. Dynamic rheological method and single photon emission computing tomography (SPECT) technique were used to ex/in vivo evaluate the thermosetting gels, respectively. An optimized formulation containing 21% F127 and 10% F68 increased the phase transition temperature by 9 degrees C as evaluated by elasticity modulus compared to that of individual 21% F127 solution. Rheological behaviors of the Pluronic solutions showed that the combined Pluronic formulation was free flowing liquid below 25 degrees C and converted to a firm gel under the physiological condition. Furthermore, this formulation possessed the highest viscosity both before and after tear dilution at 35 degrees C. Gamma scintigraphic data demonstrated that the clearance of the thermosetting gel labeled with 99mTc-DTPA was significantly delayed with respect to the phosphate buffered solution, and at least a threefold increase of the corneal residence time was achieved. However, no further improvement in the ocular retention was observed when adding HA-Na into the thermosetting gel due to the substantially decreased gel strength. Copyright 2002 Elsevier Science B.V.

  11. Oil exudation and histological structures of duck egg yolks during brining.

    Science.gov (United States)

    Lai, K M; Chung, W H; Jao, C L; Hsu, K C

    2010-04-01

    Changes in oil exudation and histological structures of salted duck egg yolks during brining up to 5 wk were investigated. During brining, the salt contents of albumen, exterior yolk (hardened portion), and interior yolk (soft or liquid portion) gradually increased accompanied by slight decreases in moisture content. The hardening ratio of salted egg yolks increased rapidly to about 60% during the first week of brining and then reached 100% at the end of brining. After brining, part of the lipids in salted egg yolk became free due to the structural changes of low-density lipoprotein induced by dehydration and increase of salt content, and more free lipids in salted egg yolk were released after the cooking process. With the brining time increased up to 5 wk, the outer region of the cooked salted yolk gradually changed into dark brown, brown, orange, and then dark brown, whereas the center region changed into light yellow, yellow, dark yellow, and then yellow again. The microstructures of cooked salted egg yolks showed that the yolk spheres in the outer and middle regions retained their original shape, with some shrinking and being packed more loosely when brining time increased, and the exuded oil filled the space between the spheres. Furthermore, the yolk spheres in the center region transformed to a round shape but still showed granulation after 4 wk of brining, whereas they were mostly disrupted after 2 to 5 wk of brining. One of the most important characteristics of cooked salted egg yolks, gritty texture, contributed to oil exudation and granulated yolk spheres were observed at the brining time of 4 wk.

  12. Differential metabolic responses of Beauveria bassiana cultured in pupae extracts, root exudates and its interactions with insect and plant.

    Science.gov (United States)

    Luo, Feifei; Wang, Qian; Yin, Chunlin; Ge, Yinglu; Hu, Fenglin; Huang, Bo; Zhou, Hong; Bao, Guanhu; Wang, Bin; Lu, Ruili; Li, Zengzhi

    2015-09-01

    Beauveria bassiana is a kind of world-wide entomopathogenic fungus and can also colonize plant rhizosphere. Previous researches showed differential expression of genes when entomopathogenic fungi are cultured in insect or plant materials. However, so far there is no report on metabolic alterations of B. bassiana in the environments of insect or plant. The purpose of this paper is to address this problem. Herein, we first provide the metabolomic analysis of B. bassiana cultured in insect pupae extracts (derived from Euproctis pseudoconspersa and Bombyx mori, EPP and BMP), plant root exudates (derived from asparagus and carrot, ARE and CRE), distilled water and minimal media (MM), respectively. Principal components analysis (PCA) shows that mycelia cultured in pupae extracts and root exudates are evidently separated and individually separated from MM, which indicates that fungus accommodates to insect and plant environments by different metabolic regulation mechanisms. Subsequently, orthogonal projection on latent structure-discriminant analysis (OPLS-DA) identifies differential metabolites in fungus under three environments relative to MM. Hierarchical clustering analysis (HCA) is performed to cluster compounds based on biochemical relationships, showing that sphingolipids are increased in BMP but are decreased in EPP. This observation further implies that sphingolipid metabolism may be involved in the adaptation of fungus to different hosts. In the meantime, sphingolipids are significantly decreased in root exudates but they are not decreased in distilled water, suggesting that some components of the root exudates can suppress sphingolipid to down-regulate sphingolipid metabolism. Pathway analysis finds that fatty acid metabolism is maintained at high level but non-ribosomal peptides (NRP) synthesis is unaffected in mycelia cultured in pupae extracts. In contrast, fatty acid metabolism is not changed but NRP synthesis is high in mycelia cultured in root exudates

  13. Retreatment of Exudative Age-Related Macular Degeneration after Loading 3-Monthly Intravitreal Ranibizumab.

    Science.gov (United States)

    Sugiyama, Atsushi; Sakurada, Yoichi; Honda, Shigeru; Miki, Akiko; Matsumiya, Wataru; Yoneyama, Seigo; Kikushima, Wataru; Iijima, Hiroyuki

    2018-01-01

    The aim of this study was to investigate the clinical implications of required retreatment after 3-monthly intravitreal ranibizumab (IVR) injections followed by as-needed reinjections up to 5 years in eyes with exudative age-related macular degeneration (AMD). A retrospective cohort study was conducted for 165 treatment-naïve eyes from 165 patients with exudative AMD. Visual changes were investigated in terms of the required retreatments. Retreatment-free proportions were 37.0, 23.7, 16.6, 12.1, and 10.5% at 12, 24, 36, 48, and 60 months, respectively. Visual changes were significantly better in eyes which did not require retreatment at every yearly checkpoint within the 5 years. A multivariate logistic regression analysis revealed that requirement of additional IVR treatments in the first 12-24 months was associated with the T allele (risk allele) of ARMS2 A69S (p = 0.010 and 0.015, respectively). Cox regression analysis revealed that older age (p = 0.046) and the T allele of ARMS2 A69S (p = 0.036) were associated with required retreatment within the 5-year follow-up period. Age and the T allele of ARMS2 A69S are the risk factors requiring retreatments, leading to poor visual change in eyes with exudative AMD following the initial 3-monthly IVR. © 2017 S. Karger AG, Basel.

  14. Alkali Metal Modification of Silica Gel-Based Stationary Phase in Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Ashraf Yehia El-Naggar

    2013-01-01

    Full Text Available Modification of the precipitated silica gel was done by treatment with alkali metal (NaCl before and after calcination. The silica surfaces before and after modification were confirmed by infrared spectroscopy in order to observe the strength and abundance of the acidic surface OH group bands which play an important role in the adsorption properties of polar and nonpolar solutes. The surface-modified silica gels were tested as GC solid stationary phases in terms of the separation efficiency for various groups of non-polar and polar solutes. Also, thermodynamic parameters (ΔH, ΔG, and ΔS were determined using n-hexane as a probe in order to show the adsorbate-adsorbent interaction. It was observed that the non-polar solutes could be separated Independent on the reactivity and porosity of the silica surfaces. The efficiency of the surface-modified silica gels to separate the aromatic hydrocarbons seemed to be strongly influenced by the density of the surface hydroxyls.

  15. Applying of isoconversional analysis to calorimetric data on the gel melting

    Science.gov (United States)

    Dranca, I.; Lupascu, T.; Povar, I.

    2012-02-01

    The present study is concerned to the thermal stability of gelatin gels that is defined that their resistance to melting or, in other words, to the thermally stimulated transitions from gel to sol. The both sol-gel and gel-sol transitions were followed by regular Mettler-Toledo DSC 823e and stochastically modulated multi-frequency DSC (TOPEM® by Mettler-Toledo). The DSC data have been treated by using an advanced isoconversional method developed by Vyazovkin [1,2]. The method allows revealing a variation in the effective activation energy (Eα) with the extent of conversion (α). It has been discovered that an increase in the concentration of gelatin solutions causes an increase in the energy barrier to melting of non-isothermally prepared gels.

  16. Heliotropium huascoense resin exudate: chemical constituents and defensive properties.

    Science.gov (United States)

    Villarroel, L; Torres, R; Urzúa, A; Reina, M; Cabrera, R; González-Coloma, A

    2001-09-01

    From the resinous exudate of Heliotropium huascoense a new compound, rel-(8R,9R)-carrizaloic acid, (1) (3-[rel-(8R,9R-9-hydroxy-9,13,13-trimethyl-12-oxo-10-cyclohexenyl)methyl]-4-methoxybenzoic acid), and three known flavonoids, [3-methylgalangin, 3,7-dimethylgalangin, and (-)-alpinone] have been isolated. The structure of 1 was determined by spectral and chemical methods. Several plant defensive properties of 1 (insecticidal and antifungal) have been evaluated.

  17. Root exudate-induced alterations in Bacillus cereus cell wall contribute to root colonization and plant growth promotion.

    Directory of Open Access Journals (Sweden)

    Swarnalee Dutta

    Full Text Available The outcome of an interaction between plant growth promoting rhizobacteria and plants may depend on the chemical composition of root exudates (REs. We report the colonization of tobacco, and not groundnut, roots by a non-rhizospheric Bacillus cereus (MTCC 430. There was a differential alteration in the cell wall components of B. cereus in response to the REs from tobacco and groundnut. Attenuated total reflectance infrared spectroscopy revealed a split in amide I region of B. cereus cells exposed to tobacco-root exudates (TRE, compared to those exposed to groundnut-root exudates (GRE. In addition, changes in exopolysaccharides and lipid-packing were observed in B. cereus grown in TRE-amended minimal media that were not detectable in GRE-amended media. Cell-wall proteome analyses revealed upregulation of oxidative stress-related alkyl hydroperoxide reductase, and DNA-protecting protein chain (Dlp-2, in response to GRE and TRE, respectively. Metabolism-related enzymes like 2-amino-3-ketobutyrate coenzyme A ligase and 2-methylcitrate dehydratase and a 60 kDa chaperonin were up-regulated in response to TRE and GRE. In response to B. cereus, the plant roots altered their exudate-chemodiversity with respect to carbohydrates, organic acids, alkanes, and polyols. TRE-induced changes in surface components of B. cereus may contribute to successful root colonization and subsequent plant growth promotion.

  18. ZnCl 2- and NH 4Cl-hydroponics gel electrolytes for zinc-carbon batteries

    Science.gov (United States)

    Khalid, N. H.; Ismail, Y. M. Baba; Mohamad, A. A.

    Absorbency testing is used to determine the percentage of ZnCl 2 or NH 4Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl 2 or NH 4Cl solution decreases with increasing solution concentration. The conductivity of ZnCl 2- and NH 4Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm -1 at 3 M ZnCl 2 and 7 M NH 4Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 Ω, a maximum power density of 12.7 and 12.2 mW cm -2, and a short-circuit current density of 29.1 and 33.9 mA cm -2 for ZnCl 2- and NH 4Cl-HPG electrolytes, respectively.

  19. Detection of exudates in fundus imagery using a constant false-alarm rate (CFAR) detector

    Science.gov (United States)

    Khanna, Manish; Kapoor, Elina

    2014-05-01

    Diabetic retinopathy is the leading cause of blindness in adults in the United States. The presence of exudates in fundus imagery is the early sign of diabetic retinopathy so detection of these lesions is essential in preventing further ocular damage. In this paper we present a novel technique to automatically detect exudates in fundus imagery that is robust against spatial and temporal variations of background noise. The detection threshold is adjusted dynamically, based on the local noise statics around the pixel under test in order to maintain a pre-determined, constant false alarm rate (CFAR). The CFAR detector is often used to detect bright targets in radar imagery where the background clutter can vary considerably from scene to scene and with angle to the scene. Similarly, the CFAR detector addresses the challenge of detecting exudate lesions in RGB and multispectral fundus imagery where the background clutter often exhibits variations in brightness and texture. These variations present a challenge to common, global thresholding detection algorithms and other methods. Performance of the CFAR algorithm is tested against a publicly available, annotated, diabetic retinopathy database and preliminary testing suggests that performance of the CFAR detector proves to be superior to techniques such as Otsu thresholding.

  20. Synthesis of phthalocyanine doped sol-gel materials

    Science.gov (United States)

    Dunn, Bruce

    1993-01-01

    The synthesis of sol-gel silica materials doped with three different types of metallophthalocyanines has been studied. Homogeneous materials of good optical quality were prepared and the first optical limiting measurements of dyes in sol-gel hosts were carried out. The properties of these solid state limiters are similar to limiters based on phthalocyanine (Pc) in solution. Sol-gel silica materials containing copper, tin and germanium phthalocyanines were investigated. The initial step in all cases was to prepare silica sols by the sonogel method using tetramethoxy silane (TMOS), HCl and distilled water. Thereafter, the synthesis depended upon the specific Pc and its solubility characteristics. Copper phthalocyanine tetrasulfonic acid tetra sodium salt (CuPc4S) is soluble in water and various doping levels (1 x 10 (exp -4) M to 1 x 10 (exp -5) M) were added to the sol. The group IV Pc's, SnPc(OSi(n-hexyl)3)2 and GePc(OSi(n-hexyl)3)2, are insoluble in water and the process was changed accordingly. In these cases, the compounds were dissolved in THF and then added to the sol. The Pc concentration in the sol was 2 x 10(exp -5)M. The samples were then aged and dried in the standard method of making xerogel monoliths. Comparative nanosecond optical limiting experiments were performed on silica xerogels that were doped with the different metallophthalocyanines. The ratio of the net excited state absorption cross section (sigma(sub e)) to the ground state cross section (sigma(sub g)) is an important figure of merit that is used to characterize these materials. By this standard the SnPc sample exhibits the best limiting for the Pc doped sol-gel materials. Its cross section ratio of 19 compares favorably with the value of 22 that was measured in toluene. The GePc materials appear to not be as useful as those containing SnPc. The GePc doped solids exhibit a higher onset energy (2.5 mj and lower cross section ratio, 7. The CuPc4S sol-gel material has a still lower cross

  1. Aqueous sulfomethylated melamine gel-forming compositions and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Meltz, C.N.; Guetzmacher, G.D.; Chang, P.W.

    1989-04-18

    A method is described for the selective modification of the permeability of the strata of a subterranean bydrocarbon-containing reservoir consisting of introducing into a well in, communication with the reservoir; an aqueous gel-forming composition, comprising a 1.0-60.0 weight percent sulfomethylated melamine polymer solution. The solution is prepared with a 1.0 molar equivalent of a malemine, reacted with 3.0-6.7 molar equivalents of formaldehyde or a 2-6 carbon atom containing dialdehyde; 0.25-1.25 molar equivalents of an alkali metal or ammonium salt of surfurous acid; and 0.01-1.5 molar equivalents of a gel-modifying agent.

  2. Optical Studies on Sol-Gel Derived Lead Chloride Crystals

    OpenAIRE

    Rejeena, I; Lillibai, B; Nithyaja, B; Nampoori, P.N V; Radhakrishnan, P

    2013-01-01

    Optical characterization of lead chloride crystals prepared by sol-gel method is reported. The relevant sol-gel technique is used for the preparation of PbCl2 samples with five different types. In this paper, we report the absorption and fluorescence behaviour of pure, UV& IR irradiated and electric & magnetic field applied lead chloride crystal samples in solution phase at two different concentrations. Optical bandgap and emission studies of these crystals are also done.

  3. The mechanisms of root exudates of maize in improvement of iron nutrition of peanut in peanut/maize intercropping system by 14C tracer technique

    International Nuclear Information System (INIS)

    Zuo Yuanmei; Chen Qing; Zhang Fusuo

    2004-01-01

    The related mechanisms of root exudates of maize in improvement iron nutrition of peanut intercropped with maize was investigated by 14 C tracer technique. Neighboring roots between maize and peanut were separated by a 30 μm nylon net, the iron nutrition of peanut was also improved just like normal intercropping of maize and peanut. The results proved that root exudates of maize played an important role in improvement iron nutrition of peanut. The photosynthesis carbohydrate of maize could exuded into the rhizosphere of peanut and transfer into shoot and root of peanut in intercropping system. Root exudates of maize could increased efficiency of iron in soil and improved iron utilization of peanut

  4. Measurement of pH, exudate composition and temperature in wound healing: a systematic review.

    Science.gov (United States)

    Power, G; Moore, Z; O'Connor, T

    2017-07-02

    To assess the potential of measurements of pH, exudate composition and temperature in wounds to predict healing outcomes and to identify the methods that are employed to measure them. A systematic review based on the outcomes of a search strategy of quantitative primary research published in the English language was conducted. Inclusion criteria limited studies to those involving in vivo and human participants with an existing or intentionally provoked wound, defined as 'a break in the epithelial integrity of the skin', and excluded in vitro and animal studies. Data synthesis and analysis was performed using structured narrative summaries of each included study arranged by concept, pH, exudate composition and temperature. The Evidence Based Literature (EBL) Critical Appraisal Checklist was implemented to appraise the quality of the included studies. A total of 23 studies, three for pH (mean quality score 54.48%), 12 for exudate composition (mean quality score 46.54%) and eight for temperature (mean quality score 36.66%), were assessed as eligible for inclusion in this review. Findings suggest that reduced pH levels in wounds, from alkaline towards acidic, are associated with improvements in wound condition. Metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP), neutrophil elastase (NE) and albumin, in descending order, were the most frequently measured analytes in wounds. MMP-9 emerged as the analyte which offers the most potential as a biomarker of wound healing, with elevated levels observed in acute or non-healing wounds and decreasing levels in wounds progressing in healing. Combined measures of different exudate components, such as MMP/TIMP ratios, also appeared to offer substantial potential to indicate wound healing. Finally, temperature measurements are highest in non-healing, worsening or acute wounds and decrease as wounds progress towards healing. Methods used to measure pH, exudate composition and

  5. Antimicrobial susceptibility of Staphylococcus hyicus Isolated from exudative epidermitis in pigs

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar; Watts, J.L.; Salmon, S.A.

    1994-01-01

    for their activities against 100 S. hyicus strains isolated from pigs with exudative epidermitis. Novobiocin was the most active compound tested, with an MIC for 90% of the strains tested (MIC(90)) of less than or equal to 0.06 mu g/ml. Enrofloxacin, ampicillin, and ceftiofur were the next most active compounds...

  6. Use of hydrocapillary dressing in the management of highly exuding ulcers

    DEFF Research Database (Denmark)

    Norkus, A.; Dargis, V.; Thomsen, J.K.

    2005-01-01

    was conducted on 97 patients with an ankle brachial pressure index > or = 0.8 and a highly exuding leg ulcer. Ulcer duration was at least four weeks.Treatment continued until healing or for a maximum of 12 months. RESULTS: There was no statistically significant difference in healing time or wound area reduction...

  7. Yield of abrams needle pleural biopsy in exudative pleural effusion

    International Nuclear Information System (INIS)

    Khan, I.N.; Zaman, M.; Khan, N.; Jadoon, H.; Ahmed, A.

    2009-01-01

    Pleural effusion is the abnormal collection of fluid in the pleural space resulting from excessive fluid production or decreased absorption and it is one of the most common clinical conditions that we come across in pulmonology clinics and in hospitals. The objective of prospective study was to evaluate the diagnostic role of Abrams Needle Biopsy in Exudative Pleural Effusion The study was performed at the Department of Pulmonology, Ayub Teaching Hospital, Abbottabad over a period of 1 year, i.e., January 2008 to December 2008. Sixty-three patients of either sex and all ages with exudative pleural effusion, on whom Abrams Needle Biopsy was performed were included in the study. Minimum of four specimens from each patient were taken and histopathology done. Out of 63 patients, histopathology revealed the cause in 60 (95%) cases. Tuberculosis, malignancy and rheumatoid pleurisy were confirmed in 34, 24, and 2 cases respectively. Specimens of 3 patients did not reveal any result and showed non-specific inflammation and were further investigated accordingly. The diagnostic yield of Biopsy was 95%. Pleural biopsy is still a reliable and valuable investigation in diagnosing pleural effusion, provided that adequate pleural specimen is taken. (author)

  8. Thermochemical Properties of Hydrophilic Polymers from Cashew and Khaya Exudates and Their Implications on Drug Delivery

    Directory of Open Access Journals (Sweden)

    Emmanuel O. Olorunsola

    2016-01-01

    Full Text Available Characterization of a polymer is essential for determining its suitability for a particular purpose. Thermochemical properties of cashew gum (CSG extracted from exudates of Anacardium occidentale L. and khaya gum (KYG extracted from exudates of Khaya senegalensis were determined and compared with those of acacia gum BP (ACG. The polymers were subjected to different thermal and chemical analyses. Exudates of CSG contained higher amount of hydrophilic polymer. The pH of 2% w/v gum dispersions was in the order KYG < CSG < ACG. Calcium was the predominant ion in CSG while potassium was predominant in KYG. The FTIR spectra of CSG and KYG were similar and slightly different from that of ACG. Acacia and khaya gums exhibited the same thermal behaviour which is different from that of CSG. X-ray diffraction revealed that the three gums are the same type of polymer, the major difference being the concentration of metal ions. This work suggests the application of cashew gum for formulation of basic and oxidizable drugs while using khaya gum for acidic drugs.

  9. Dehydrocostus lactone is exuded from sunflower roots and stimulates germination of the root parasite Orobanche cumana.

    Science.gov (United States)

    Joel, Daniel M; Chaudhuri, Swapan K; Plakhine, Dina; Ziadna, Hammam; Steffens, John C

    2011-05-01

    The germination of the obligate root parasites of the Orobanchaceae depends on the perception of chemical stimuli from host roots. Several compounds, collectively termed strigolactones, stimulate the germination of the various Orobanche species, but do not significantly elicit germination of Orobanche cumana, a specific parasite of sunflower. Phosphate starvation markedly decreased the stimulatory activity of sunflower root exudates toward O. cumana, and fluridone - an inhibitor of the carotenoid biosynthesis pathway - did not inhibit the production of the germination stimulant in both shoots and roots of young sunflower plants, indicating that the stimulant is not a strigolactone. We identified the natural germination stimulant from sunflower root exudates by bioassay-driven purification. Its chemical structure was elucidated as the guaianolide sesquiterpene lactone dehydrocostus lactone (DCL). Low DCL concentrations effectively stimulate the germination of O. cumana seeds but not of Phelipanche aegyptiaca (syn. Orobanche aegyptiaca). DCL and other sesquiterpene lactones were found in various plant organs, but were previously not known to be exuded to the rhizosphere where they can interact with other organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Precipitation and ultimate pH effect on chemical and gelation properties of protein prepared by isoelectric solubilization/precipitation process from pale, soft, exudative (PSE)-like chicken breast meat1.

    Science.gov (United States)

    Zhao, X; Xing, T; Chen, X; Han, M-Y; Li, X; Xu, X-L; Zhou, G-H

    2017-05-01

    Pale, soft, exudative (PSE)-like chicken breast is considered deteriorated raw material in the poultry meat industry that has inferior processing ability. The chemical and gelation properties of PSE-like chicken breast meat paste were studied. These pastes were prepared by the pH adjustment method and protein isolation using the isoelectric solubilization/precipitation (ISP) process from PSE-like chicken meat. The ISP-isolated samples were solubilized at pH 11.0 and recovered at pH 5.5 and 6.2. The ultimate pH of the ISP-isolated protein and meat paste was adjusted to 6.2 and 7.0. The ultimate pH in this article referred to the final pH of the extracted protein and meat paste. Higher reactive sulfhydryl content and surface hydrophobicity were found in the precipitation at pH 6.2 than at pH 5.5. However, various ultimate pH values showed no significant influence on the surface hydrophobicity. The hardness of gel, as measured by textural profile analysis, was improved using 6.2 as the precipitation pH compared with pH 5.5. The viscoelastic modulus (G΄) of gel pastes prior to the thermal gelation was higher with ISP treatment. However, lower G΄ was seen after thermal gelation compared with the control. Dynamic rheological measurement demonstrated a different gel-forming mechanism for protein precipitated at pH values of 5.5 and 6.2 compared with the meat paste. The cooking loss showed that the recovered protein failed to form a gel with good water-retention capacity unless the ultimate pH was adjusted to 7.0. Gels made from protein extracted by the ISP method had higher yellowness and lower redness values, probably due to protein denaturation. Precipitation at pH 6.2 formed a harder gel with lower water-retention ability than that at pH 5.5, and this result was possibly due to higher surface hydrophobicity and S-S bridge formation. Overall, network characteristics of ISP-treated protein gels were strongly dependent on precipitation pH and ultimate pH. © 2016

  11. Processing of radioactive ruthenium with aluminosilicate gels

    International Nuclear Information System (INIS)

    Kanno, Takuji; Ichinose, Yasuhiro; Ito, Katsuo

    1979-01-01

    Coprecipitation of radioactive Ru with hydroxides has been studied for the purpose of the management of the high level waste from the nuclear fuel reprocessing. Aluminosilicate gel used as coprecipitant was prepared by addition of aqueous sodium hydroxide to sodium aluminate-sodium silicate solution containing ruthenium nitrate. Ruthenium quantitatively precipitates under the conditions, aluminate > 4 x 10 -2 M, Al/Si 0 C. However, volatilization rate of Ru is suppressed by coating with mullite phase into which aluminosilicate gel transformes above 900 0 C. The amount of Ru volatilized in Ar-flow was reduced to about 10% of that in air-flow. (author)

  12. Investigation on safety of gel decontamination technology

    International Nuclear Information System (INIS)

    Liu Zhihui; Song Fengli; Wang Yongxian; Zhang Taoge

    2014-01-01

    Gel decontamination technology is an advanced decontamination process of metal contaminated by radionuclide. It has the advantages such as simple operation process, high decontaminating factor, etc. But the disadvantages are that it has high spraying pressure and is strongly corrosive, which has safety risk to the operator and equipment. The effect of such factors as spraying pressure on operators was analyzed based on process feature, and it is proposed that it be worthwhile to make further study on the corrosion of gels to spraying equipment, taking into account corrosion feature of gels to stainless steel. Meanwhile, the safety issue was demonstrated on collecting and handling wastes from gel decontamination process. And then, protective measures, study methods, and solutions are put forward. The results show that protection should be strengthened during spraying to reduce the effect of splashing and fogging on workers; the equipment should be cleaned in time to reduce the effect of corrosion, and reducers should be added into waste liquid to eliminate the effect of residual detergent. (authors)

  13. Analysis of Two-Dimensional Electrophoresis Gel Images

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2002-01-01

    This thesis describes and proposes solutions to some of the currently most important problems in pattern recognition and image analysis of two-dimensional gel electrophoresis (2DGE) images. 2DGE is the leading technique to separate individual proteins in biological samples with many biological...

  14. Fabrication and characterization of poly(L-lactic acid) gels induced by fibrous complex crystallization with solvents

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Yasuhiro [ORNL; Fukatsu, Akinobu [Shizuoka University, Hamamatsu, Japan; Wang, Yangyang [ORNL; Miyamoto, Kazuaki [Shizuoka University, Hamamatsu, Japan; Mays, Jimmy [University of Tennessee, Knoxville (UTK); Tasaka, Shigeru [Shizuoka University, Hamamatsu, Japan

    2014-01-01

    Complex crystal induced gelation of poly(L-lactic acid) (PLLA) solutions was studied for a series of solvents, including N,N-dimethylformamide (DMF). By cooling the solutions prepared at elevated temperatures, PLLA gels were produced in solvents that induced complex crystals ( -crystals) with PLLA. Fibrous structure of PLLA in the gel with DMF was observed by polarizing optical microscopy, field emission electron microscopy, and atomic force microscopy. Upon heating, the crystal form of PLLA in the DMF gel changed from -crystal to a-crystal, the major crystal form in common untreated PLLA films, but the morphology and high elastic modulus of the gel remained until the a-crystal dissolved at higher temperature. In addition, a solvent exchanging method was developed, which allowed PLLA gels to be prepared in other useful solvents that do not induce -crystals without losing the morphology and mechanical properties.

  15. 3D MR gel dosimetry with lung equivalent gel

    International Nuclear Information System (INIS)

    Scherer, J.; Solleder, M.; Schiessl, I.; Bogner, L.; Herbst, M.

    1998-01-01

    The MR gel dosimetry is used to verify complex 3D treatment plans. Till now this method served only for dose evaluation in homogeneous phantoms. On the way to build a heterogeneous anthropomorphic gel phantom, a lung equivalent gel with the density 0.4 g/cm 3 was developed. First experiments show a 1.55 times higher dose reponse in the low density gel (LD gel). The comparison of a dose distribution in a gel/LD gel/gel slab phantom with Monte Carlo calculations shows good agreement within 5%. More over the accuray of the measuring device magnetic resonance imager was studied in respect to the now exclusive digital image processing with the software MRD (MR dosimetry). Because of the dimensions of the Fricke gel phantom an artefact correction, based on the data from the unirradiated phantom proved to be essential. (orig.) [de

  16. Sustained subconjunctival protein delivery using a thermosetting gel delivery system.

    Science.gov (United States)

    Rieke, Erin R; Amaral, Juan; Becerra, S Patricia; Lutz, Robert J

    2010-02-01

    An effective treatment modality for posterior eye diseases would provide prolonged delivery of therapeutic agents, including macromolecules, to eye tissues using a safe and minimally invasive method. The goal of this study was to assess the ability of a thermosetting gel to deliver a fluorescently labeled protein, Alexa 647 ovalbumin, to the choroid and retina of rats following a single subconjunctival injection of the gel. Additional experiments were performed to compare in vitro to in vivo ovalbumin release rates from the gel. The ovalbumin content of the eye tissues was monitored by spectrophotometric assays of tissue extracts of Alexa 647 ovalbumin from dissected sclera, choroid, and retina at time points ranging from 2 h to 14 days. At the same time points, fluorescence microscopy images of tissue samples were also obtained. Measurement of intact ovalbumin was verified by LDS-PAGE analysis of the tissue extract solutions. In vitro release of Alexa 488 ovalbumin into 37 degrees C PBS solutions from ovalbumin-loaded gel pellets was also monitored over time by spectrophotometric assay. In vivo ovalbumin release rates were determined by measurement of residual ovalbumin extracted from gel pellets removed from rat eyes at various time intervals. Our results indicate that ovalbumin concentrations can be maintained at measurable levels in the sclera, choroid, and retina of rats for up to 14 days using the thermosetting gel delivery system. The concentration of ovalbumin exhibited a gradient that decreased from sclera to choroid and to retina. The in vitro release rate profiles were similar to the in vivo release profiles. Our findings suggest that the thermosetting gel system may be a feasible method for safe and convenient sustained delivery of proteins to choroidal and retinal tissue in the posterior segments of the eye.

  17. Influence of starch origin on rheological properties of concentrated aqueous solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Željko P.

    2011-01-01

    Full Text Available The rheological properties of corn and potato starch concentrated aqueous solutions were investigated at 25ºC. The starches were previously dispersed in water and the solutions were obtained by heating of dispersions at 115-120ºC for 20 minutes. The solutions of potato starch were transparent, while the corn starch solutions were opalescent. The results of dynamic mechanical measurements showed that the values of viscosity, h, storage modulus, G′, and loss modulus, G″, of the corn starch solutions increased with the storage time. This phenomenon was not observed for the potato starch solutions. It was assumed that the increase of h, G′ and G″ is the result of starch solutions retrogradation. The potato starch solutions retrogradation did not occur probably because of the phosphates presence. The viscosity of 2 mass % corn starch solution is less than the viscosity of 2 mass % potato starch solution. By increasing the concentration of corn starch solution the gel with elastic behavior was formed. The corn starch solutions formed gel as early as at 4 mass % concentration, while potato starch solutions achieved the gel state at the concentration of 5 mass %. The value of exponent m (G′ and G″ µ wm during the transition of potato starch solutions to gel is 0.414, which gives the fractal dimensions for corn starch of 2.10. The obtained value of fractal dimension corresponds to slow aggregation. The corn starch solutions with the starch concentrations higher than 4 mass % form weak gels. For these solutions the values of modulus in rubber plateau were determined. It was found that the modulus in rubber plateau increased with the concentration by the exponent of 4.36. Such high exponent value was obtained in the case when the tridimensional network is formed, i.e. when supermolecular structures like associates or crystal domains are formed.

  18. Preparation and characterization of conductive and transparent ruthenium dioxide sol-gel films.

    Science.gov (United States)

    Allhusen, John S; Conboy, John C

    2013-11-27

    RuO2 conductive thin films were synthesized using the sol-gel method and deposited onto transparent insulating substrates. The optical transmission, film thickness, surface morphology and composition, resistivity, and spectroelectrochemical performance have been characterized. The optical transmission values of these films ranged from 70 to 89% in the visible region and from 56 to 88% in the infrared region. Resistivity values of the RuO2 sol-gel films varied from 1.02 × 10(-3) to 1.13 Ω cm and are highly dependent on the initial solution concentration of RuO2 in the sol-gel. The RuO2 sol-gel films were used as electrodes for the electrochemical oxidation and reduction of ferrocenemethanol. The electrochemical behavior of our novel RuO2 sol-gel films was compared to that of a standard platinum disk electrode and showed no appreciable differences in the half-wave potential (E1/2). The mechanical and chemical stability of the coatings was tested by physical abrasion and exposure to highly acidic, oxidizing Piranha solution. Repeated exposure to these extreme conditions did not result in any appreciable decline in electrochemical performance. Finally, the use of the novel RuO2 sol-gel conductive and transparent films was demonstrated in a spectroelectrochemistry experiment in which the oxidation and reduction of ferrocenemethanol was monitored via UV-vis spectroscopy as the applied potential was cycled.

  19. Influence of root exudates on attachment of Pasteuria penetrans to Meloidogyne arenaria

    Science.gov (United States)

    We hypothesized that root exudates would influence the spore attachment of Pasteuria penetrans to root-knot nematodes (Meloidogyne arenaria). An experiment was carried out using a factorial arrangement of two single spore (SS) lines cultured from P. penetrans and three single egg mass(SEM)lines cult...

  20. Some Structural Observations of Self-Assembling, Fibrillar Gels Composed of Two-Directional Bolaform Arborols

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.

    2005-01-12

    Arborols are dumbbell shaped molecules (bolaform amphiphiles) in which a hydrophobic spacer separates two hydrophilic end groups. They are a valuable model for naturally occurring fibers, such as actin or amyloid. Applications to materials science can be envisioned. On cooling from warm aqueous or methanolic solutions, arborols spontaneously assemble into long fibers. When the solutions are above a certain concentration that depends on the hydrophilic/hydrophobic balance, this leads to thermally reversible gels stabilized by a mechanism that is poorly understood. With the help of wide angle X-ray scattering, details of the arborol fiber and gel structure were obtained on wet gels. The characteristic dimensions of the fibers vary in a sensible fashion with the molecular specifics. Solvent character appears to affect the average domain length of arborols stacked into fibers. Fluorescently labeled arborols were prepared. The label does not prevent incorporation into the fibrillar structure, rendering fibril bundles visible in wet gels. Bundles are visible in concentrated gels, but not in less concentrated sols. These results are consistent with observations of dried arborols using atomic force microscopy and with previously published freeze-fracture electron microscopy and small angle X-ray scattering experiments on dried gels.

  1. Thin film composites in the BiFeO3–Bi4Ti3O12 system obtained by an aqueous solution-gel deposition methodology

    Directory of Open Access Journals (Sweden)

    Carlos Gumiel

    2018-01-01

    Full Text Available Thin film multiferroic composites, with a high quantity of interfaces between the different materials, represent a more feasible alternative to single phase systems in which the multifunctional response is usually hampered due to intrinsic physical constraints. Nowadays some of these composites can be produced by applying deposition techniques such as PLD, CVD, MBE or the like, which allow a high degree of crystallographic control. However, despite their effectiveness, all these techniques also involve a high consumption of energy in terms of temperature and/or vacuum. Within this frame, the present contribution proposes a sustainable chemical solution deposition process to prepare thin films of the multiferroic BiFeO3–Bi4Ti3O12 composite system. More specifically an aqueous solution-gel plus spin-coating methodology is employed which also avoids the organic solvents typically used in a conventional sol–gel method, so further keeping an eye on the environmentally friendly conditions. Attempts are conducted that demonstrate how by systematically controlling the processing parameters it is possible to obtain thin film composites with a promising 3-3 type connectivity at temperatures as low as 600 °C.

  2. Thin film composites in the BiFeO3–Bi4Ti3O12 system obtained by an aqueous solution-gel deposition methodology

    International Nuclear Information System (INIS)

    Gumiel, C.; Vranken, T.; Bernardo, M.S.; Jardiel, T.; Hardy, A.; Van Bael, M.K.; Peiteado, M.

    2018-01-01

    Thin film multiferroic composites, with a high quantity of interfaces between the different materials, represent a more feasible alternative to single phase systems in which the multifunctional response is usually hampered due to intrinsic physical constraints. Nowadays some of these composites can be produced by applying deposition techniques such as PLD, CVD, MBE or the like, which allow a high degree of crystallographic control. However, despite their effectiveness, all these techniques also involve a high consumption of energy in terms of temperature and/or vacuum. Within this frame, the present contribution proposes a sustainable chemical solution deposition process to prepare thin films of the multiferroic BiFeO3–Bi4Ti3O12 composite system. More specifically an aqueous solution-gel plus spin-coating methodology is employed which also avoids the organic solvents typically used in a conventional sol–gel method, so further keeping an eye on the environmentally friendly conditions. Attempts are conducted that demonstrate how by systematically controlling the processing parameters it is possible to obtain thin film composites with a promising 3-3 type connectivity at temperatures as low as 600°C. [es

  3. The components of rice and watermelon root exudates and their effects on pathogenic fungus and watermelon defense.

    Science.gov (United States)

    Ren, Lixuan; Huo, Hongwei; Zhang, Fang; Hao, Wenya; Xiao, Liang; Dong, Caixia; Xu, Guohua

    2016-06-02

    Watermelon (Citrullus lanatus) is susceptible to wilt disease caused by the fungus Fusarium oxysporum f. sp niveum (FON). Intercropping management of watermelon/aerobic rice (Oryza sativa) alleviates watermelon wilt disease, because some unidentified component(s) in rice root exudates suppress FON sporulation and spore germination. Here, we show that the phenolic acid p-coumaric acid is present in rice root exudates only, and it inhibits FON spore germination and sporulation. We found that exogenously applied p-coumaric acid up-regulated the expression of ClPR3 in roots, as well as increased chitinase activity in leaves. Furthermore, exogenously applied p-coumaric acid increased β-1,3-glucanase activity in watermelon roots. By contrast, we found that ferulic acid was secreted by watermelon roots, but not by rice roots, and that it stimulated spore germination and sporulation of FON. Exogenous application of ferulic acid down-regulated ClPR3 expression and inhibited chitinase activity in watermelon leaves. Salicylic acid was detected in both watermelon and rice root exudates, which stimulated FON spore germination at low concentrations and suppressed spore germination at high concentrations. Exogenously applied salicylic acid did not alter ClPR3 expression, but did increase chitinase and β-1,3-glucanase activities in watermelon leaves. Together, our results show that the root exudates of phenolic acids were different between rice and watermelon, which lead to their special ecological roles on pathogenic fungus and watermelon defense.

  4. SOL-Gel microspheres and nanospheres for controlled release applications

    International Nuclear Information System (INIS)

    Barbe, C.; Beyer, R.; Kong, L.; Blackford, M.; Trautman, R.; Bartlett, J.

    2002-01-01

    We present a novel approach to the synthesis of inorganic sol-gel microspheres for encapsulating organic and bioactive molecules, and controlling their subsequent release kinetics. The bioactive species are incorporated, at ambient temperature, into the inorganic particles using an emulsion gelation process. Independent control of the release rate (by adapting the nanostructure of the internal pore network to the physico-chemical properties of the bioactive molecules) and particle size (by tailoring the emulsion chemistry) is demonstrated. Sol-gel chemistry has been shown to be a flexible technique for producing inorganic silica matrices with tailored microstructures, which can be used for the encapsulation and controlled release of organic and bioactive molecules. The present paper extends this concept by combining sol-gel chemistry with an emulsion approach for producing inorganic particles with controlled dimensions, and demonstrates how the particle size and microstructure can be independently controlled. Sol-Gel Chemistry and Encapsulation of Model Compounds. A stock solution of 4-(2-hydroxy-l-naphthylazo) benzene sulfonic acid (Orange II) was produced by dissolving Orange II in water (0.1 wt%), and adjusting the pH to the required value. Sol-gel solutions were subsequently prepared by mixing the aqueous solution with tetramethylorthosilicate (TMOS) and methanol (MeOH), to achieve H 2 O:TMOS (W] and MeOH:TMOS mole ratios (D) of four. The resulting solution was stirred and left to age at ambient temperature for one day. A transparent emulsion was prepared by mixing selected surfactants and organic solvents. The surfactants used included sorbitan monooleate, sorbitan monolaurate and bis-2-ethylhexylsulfo-succinate (AOT), while the organic phase was typically chosen from the group consisting of kerosene, hexane, heptane, octane, decane, dodecane and cyclohexane. The sol-gel solution was added to the emulsion, and the resulting mixture was stirred at 500 rpm for

  5. Development of lidocaine gels for enhanced local anesthetic action.

    Science.gov (United States)

    Shin, Sang-Chul; Cho, Cheong-Weon; Yang, Kyu-Ho

    2004-12-09

    In relieving local pains, lidocaine, one of ester type local anesthetics, has been used. To develop the lidocaine gels of enhanced local anesthetic effects, hydroxypropyl methylcellulose (HPMC) based bioadhesive polymer gel containing an enhancer was formulated. As the drug concentration in the gels increased up to 3%, the permeation rate of drug linearly increased, thereafter reaching a plateau. As the temperature of surrounding solutions increased, the permeation of drug increased. The activation energy of drug permeation was 3.29 kcal/mol for lidocaine. The permeation rate of drug through skin was studied using various enhancers, such as glycols, non-ionic surfactants, and bile salts. Among the enhancers studied, diethylene glycol showed the greatest enhancing effects on drug permeation through skin. The analgesic activity was examined using a tail-flick analgesimeter. In the area under the efficacy curve (AUEC) of the rat-tail flick tests, lidocaine gel containing diethylene glycol showed about 3.89-fold increase in analgesic activity compared with the control. The addition of vasoconstrictor in the gels prolonged the analgesic effects. The result of this study supports that the bioadhesive gel with efficient anesthetic effect could be developed using HPMC with combination of enhancer and vasoconstrictor.

  6. Effect of microcystins on root growth, oxidative response, and exudation of rice (Oryza sativa).

    Science.gov (United States)

    Cao, Qing; Rediske, Richard R; Yao, Lei; Xie, Liqiang

    2018-03-01

    A 30 days indoor hydroponic experiment was carried out to evaluate the effect of microcystins (MCs) on rice root morphology and exudation, as well as bioaccumulation of MCs in rice. MCs were bioaccumulated in rice with the greatest concentrations being observed in the leaves (113.68μgg -1 Fresh weight (FW)) when exposed to 500μgL -1 MCs. Root activity at 500μgL -1 decreased 37%, compared to the control. MCs also induced disruption of the antioxidant system and lipid peroxidation in rice roots. Root growth was significantly inhibited by MCs. Root weight, length; surface area and volume were significantly decreased, as well as crown root number and lateral root number. After 30 days exposure to MCs, an increase was found in tartaric acid and malic acid while the other organic acids were not affected. Glycine, tyrosine, and glutamate were the only amino acids stimulated at MCs concentrations of 500μgL -1 . Similarly, dissolved organic carbon (DOC) and carbohydrate at 50 and 500μgL -1 treatments were significantly increased. The increase of DOC and carbohydrate in root exudates was due to rice root membrane permeability changes induced by MCs. Overall, this study indicated that MCs significantly inhibited rice root growth and affected root exudation. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Ultrasound guided pleural biopsy in undiagnosed exudative pleural effusion patients

    OpenAIRE

    Adel S. Ahmed; Mostafa I. Ragab; Alaa eldin M. Elgazaar; Nagwan A. Ismail

    2016-01-01

    Introduction: Pleural biopsy for pathological confirmation is the standard diagnostic procedure for pleural diseases, transthoracic ultrasonography (TUS) has evolved as an important imaging tool for diagnosing pleural and pulmonary conditions. Aim of the study: To assess the diagnostic yield of TUS guided pleural biopsy versus both CT guided and thoracoscopic pleural biopsy in the diagnosis of undiagnosed exudative pleural effusion. Patients and methods: The study was conducted at chest...

  8. Radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Baldock, C.

    2002-01-01

    shapes and sizes while sparing normal tissue. The situation is further complicated if the normal tissues are critical organs or are particularly sensitive to radiation. Radiotherapy techniques employed to obtain a closer conformation of the dose distribution to the tumour volume are referred to as conformal radiotherapy techniques. The clinical implementation of conformal therapy has been delayed by limitations in the verification of conformal dose distributions calculated by treatment planning systems prior to the irradiation of the patient and the verification of complex treatments during its delivery to the patient. There are several aspects of conformal therapy that complicate dose verification. To achieve the dose distributions conforming to complex 3D volumes, high dose gradients arise in the treatment volume. Further, overdose or underdose regions can exist when separate radiation fields are used to deliver additional radiation. These aspects require that practical dose measurement (dosimetry) techniques be able to integrate dose over time and easily measure dose distributions in 3D with high spatial resolution. Traditional dosimeters, such as ion chambers, thermoluminescent dosimeters and radiographic film do not fulfil these requirements. Novel gel dosimetry techniques are being developed in which dose distributions can potentially be determined in vitro in 3D using anthropomorphic phantoms to simulate a clinically irradiated situation. As long ago as the 1950's, radiation-induced colour change in dyes was used to investigate radiation doses in gels. It was subsequently shown that radiation induced changes in nuclear magnetic resonance (NMR) relaxation properties of gels infused with conventional Fricke dosimetry solutions could be measured using magnetic resonance imaging (MRI). In Fricke gels, Fe 2+ ions in ferrous sulphate solutions are usually dispersed throughout a gelatin, agarose or PVA matrix. Radiation-induced changes in the dosimeters are considered to

  9. Superconductive ceramics obtained with sol gel method

    International Nuclear Information System (INIS)

    Arcangeli, A.; Mosci, A.; Nardi, A.; Vatteroni, R.; Zondini, C.

    1988-01-01

    Several sol gel routes have been considered, studied and developed to produce large quantities of granulates which can be processed to obtain ceramics having good superconducting characteristics. In the considered process a mixture of commercial nitrates is atomized, at room temperature, in a solution 1:1 of Primene JMT and Benzene and a pale blue gel of the starting elements is suddently formed. The granulates obtained are free flowing, very reactive and well suited for pressing. For their intrinsic characteristics they could be very good precursors for the production of large quantities of superconductive ceramics in different forms. The precipitated gel is dried, calcinated, pressed in the form of cylindrical pellets which are sintered up to 960 degrees C. No griding or different thermal treatments are needed. The sintered material has low electric resistence, shows a clear Meissner effect and has a transition temperature of between 91 and 95 K

  10. Diagnosis of non-exudative (DRY) age related macular degeneration by non-invasive photon-correlation spectroscopy.

    Science.gov (United States)

    Fankhauser, Franz Ii; Ott, Maria; Munteanu, Mihnea

    2016-01-01

    Photon-correlation spectroscopy (PCS) (quasi-elastic light scattering spectroscopy, dynamic light scattering spectroscopy) allows the non-invasively reveal of local dynamics and local heterogeneities of macromolecular systems. The capability of this technique to diagnose the retinal pathologies by in-vivo investigations of spatial anomalies of retinas displaying non-exudative senile macular degeneration was evaluated. Further, the potential use of the technique for the diagnosis of the macular degeneration was analyzed and displayed by the Receiver Operating Curve (ROC). The maculae and the peripheral retina of 73 normal eyes and of 26 eyes afflicted by an early stage of non-exudative senile macular degeneration were characterized by time-correlation functions and analyzed in terms of characteristic decay times and apparent size distributions. The characteristics of the obtained time-correlation functions of the eyes afflicted with nonexudative macular degeneration and of normal eyes differed significantly, which could be referred to a significant change of the nano- and microstructure of the investigated pathologic maculas. Photon-correlation spectroscopy is able to assess the macromolecular and microstructural aberrations in the macula afflicted by non-exudative, senile macular degeneration. It has been demonstrated that macromolecules of this disease show a characteristic abnormal behavior in the macula.

  11. Raise of efficiency of flocculation-precipitation treatment of exuding water from reclaimed land by irradiation

    International Nuclear Information System (INIS)

    Sawai, Teruko; Yamazaki, Masao; Sawai, Takeshi

    1984-01-01

    When rain falls on the coastal reclaimed land filled with home garbage in Tokyo, a large quantity of water containing much organic contaminant flows out. It is difficult to treat this water exuding from reclaimed land by conventional method. Because the water with low BOD which is difficult to treat by biological process flows out for long period after the stabilization of reclaimed land. When the water is treated by flocculation and precipitation, the substances with high molecular weight are easily removed, but the rate of removal of fulvic acid with low molecular weight, which accounts for more than 60% of the composition of the water, is very poor. Therefore, it was examined to change the fulvic acid to high molecular weight by irradiation, and to improve the efficiency of the flocculation-precipitation treatment of exuding water. Exuding water was sampled in Tokyo Bay No.15 reclaimed land, and it was separated into humic acid and fulvic acid. The Co-60 gamma ray of 5 kCi was irradiated to the samples. The experimental method and the results are reported. The change of fulvic acid to high molecular weight by irradiation was most efficient at pH 2.2. More than 90% of organic contaminants was able to be removed. (Kako, I.)

  12. A sol-gel method to synthesize indium tin oxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

    2011-01-01

    Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 % of theoretical density (TD).

  13. Influence of ionic constituents and electrical conductivity on the propagation of charged nanoscale objects in passivated gel electrophoresis.

    Science.gov (United States)

    Bikos, Dimitri A; Mason, Thomas G

    2018-01-01

    When determining the electric field E acting on charged objects in gel electrophoresis, the electrical conductivity of the buffer solution is often overlooked; E is typically calculated by dividing the applied voltage by a separation distance between electrodes. However, as a consequence of electrolytic reactions, which occur at the electrodes, gradients in the ionic content of the buffer solution and its conductivity can potentially develop over time, thereby impacting E and affecting propagation velocities of charged objects, v, directly. Here, we explore how the types and concentrations of ionic constituents of the buffer solution, which largely control its conductivity, when used in passivated gel electrophoresis (P-gelEP), can influence E, thereby altering v of charged nanospheres propagating through large-pore gels. We measure the conductivity of the buffer solution in the center of the gel region near propagating bands of nanospheres, and we show that predictions of E based on conductivity closely correlate with v. We also explore P-gelEP involving two different types of passivation agents: nonionic polyethylene glycol (PEG) and anionic sodium dodecyl sulfate (SDS). Our observations indicate that using a conductivity model to determine E from the local current density and the conductivity where spheres are propagating can lead to a better estimate than the standard approach of a voltage divided by a separation. Moreover, this conductivity model also provides a starting point for interpreting the complex behavior created by amphiphilic ionic passivation agents, such as SDS, on propagating nanospheres used in some P-gelEP experiments. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Novel polymeric systems for lithium-ion batteries gel electrolytes

    International Nuclear Information System (INIS)

    Appetecchi, G.B.; Alessandrini, F.; Passerini, S.; Caporiccio, G.; Boutevin, B.; Guida-Pietrasanta, F.

    2004-01-01

    The investigation of chemically cross-linked, self-supporting gel-type electrolyte membranes, based on hybrid polyfluorosilicone polymers reinforced with nanosized silica, for lithium-ion battery systems is reported. The polyfluorosilicone materials were selected on the basis of their high chemical and thermal stabilities. The precursors were synthesized with functional groups capable to form inter-molecular cross-linking, thus obtaining three-dimensional polymer matrices. The latter were undergone to swelling processes in (non-aqueous, lithium salt containing) electrolytic solutions to obtain gel-type polymer electrolytes. Several kinds of membranes, based on different types of polyfluorosilicone precursor, were prepared and characterized in terms of swelling behavior, ionic conductivity and electrochemical stability. The properties of the swelled matrices were evaluated as a function of dipping time, temperature, kind of electrolytic solution and cross-linking initiator content

  15. Diversity and function of the microbial community on anodes of sediment microbial fuel cells fueled by root exudates

    Energy Technology Data Exchange (ETDEWEB)

    Cabezas da Rosa, Angela

    2010-11-26

    Anode microbial communities are essential for current production in microbial fuel cells. Anode reducing bacteria are capable of using the anode as final electron acceptor in their respiratory chain. The electrons delivered to the anode travel through a circuit to the cathode where they reduce oxygen to water generating an electric current. A novel type of sediment microbial fuel cell (SMFC) harvest energy from photosynthetically derived compounds released through the roots. Nothing is known about anode microbial communities of this type of microbial fuel cell. This work consists of three parts. The first part focuses on the study of bacterial and archaeal community compositions on anodes of SMFCs fueled by rice root exudates. By using terminal restriction fragment length polymorphism (T-RFLP), a profiling technique, and cloning / sequencing of 16S rRNA, we determined that the support type used for the plant (vermiculite, potting soil or rice field soil) is an important factor determining the composition of the microbial community. Finally, by comparing microbial communities of current producing anodes and non-current producing controls we determined that Desulfobulbus- and Geobacter-related populations were probably most important for current production in potting soil and rice field soil SMFCs, respectively. However, {delta}-proteobacterial Anaeromyxobacter spp., unclassified {delta}-proteobacteria and Anaerolineae were also part of the anode biofilm in rice field soil SMFCs and these populations might also play a role in current production. Moreover, distinct clusters of Geobacter and Anaeromyxobacter populations were stimulated by rice root exudates. Regarding Archaea, uncultured Euryarchaea were abundant on anodes of potting soil SMFCs indicating a potential role in current production. In both, rice field soil and potting soil SMFCs, a decrease of Methanosaeta, an acetotrophic methanogen, was detected on current producing anodes. In the second part we focused

  16. Tunable Temperature Response of a Thermochromic Photonic Gel Sensor Containing N-Isopropylacrylamide and 4-Acryloyilmorpholine

    Directory of Open Access Journals (Sweden)

    Hwanam Kye

    2017-06-01

    Full Text Available In this study, thermochromic photonic gels were fabricated using 2-hydroxyethyl methacrylate (HEMA as a hydrogel building block, and 4-Acryloyl morpholine (ACMO and N-isopropylacrylamide (NIPAAM as thermoresponsive monomers with different critical solution temperature behaviors. Rapid photopolymerization of opal-templated monomer mixtures of varying ACMO contents formed five individual thermochromic inverse opal photonic gels integrated on a single substrate. With temperature variation from 10 °C to 80 °C, the changes in reflective colors and reflectance spectra of the respective thermochromic gels were noted, and λpeak changes were plotted. Because NIPAAM exhibits a lower critical solution temperature (LCST at 33 °C, the NIPAAM-only gel showed a steep slope for dλpeak/dT below 40 °C, whereas the slope became flatter at high temperatures. As the ACMO content increased in the thermochromic gel, the curve of dλpeak/dT turned out to be gradual within the investigated temperature range, exhibiting the entire visible range of colors. The incorporation of ACMO in NIPAAM-based thermochromic gels therefore enabled a better control of color changes at a relatively high-temperature regime compared to a NIPAAM-only gel. In addition, ACMO-containing thermochromic gels exhibited a smaller hysteresis of λpeak for the heating and cooling cycle.

  17. Organic acid compounds in root exudation of Moso Bamboo (Phyllostachys pubescens) and its bioactivity as affected by heavy metals.

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Liu, Chen; Zhong, Bin; Guo, Hua; He, Lizhi; Liu, Dan

    2016-10-01

    Moso bamboo (Phyllostachys pubescens) has great potential as phytoremediation material in soil contaminated by heavy metals. A hydroponics experiment was conducted to determine organic acid compounds of root exudates of lead- (Pb), zinc- (Zn), copper- (Cu), and cadmium (Cd)-tolerant of Moso bamboo. Plants were grown in nutrients solution which included Pb, Zn, Cu, and Cd applied as Pb(NO 3 ) 2 (200 μM), ZnSO 4 ·7H 2 O (100 μM), CuSO 4 ·5H 2 O (25 μM), and CdCl 2 (10 μM), respectively. Oxalic acid and malic acid were detected in all treatments. Lactic acid was observed in Cu, Cd, and control treatments. The oxalic was the main organic acid exudated by Moso bamboo. In the sand culture experiment, the Moso bamboo significantly activated carbonate heavy metals under activation of roots. The concentration of water-soluble metals (except Pb) in sand were significantly increased as compared with control. Organic acids (1 mM mixed) were used due to its effect on the soil adsorption of heavy metals. After adding mixed organic acids, the Cu and Zn sorption capacity in soils was decreased markedly compared with enhanced Pb and Cd sorption capacity in soils. The sorption was analyzed using Langmuir and Freundlich equations with R 2 values that ranged from 0.956 to 0.999 and 0.919 to 0.997, respectively.

  18. Ionogel Electrolytes through Sol-Gel Processing

    Science.gov (United States)

    Horowitz, Ariel I.

    Electrical energy needs have intensified due to the ubiquity of personal electronics, the decarbonization of energy services through electrification, and the use of intermittent renewable energy sources. Despite developments in mechanical and thermal methods, electrochemical technologies are the most convenient and effective means of storing electrical energy. These technologies include both electrochemical cells, commonly called batteries, and electrochemical double-layer capacitors, or "supercapacitors", which store energy electrostatically. Both device types require an ion-conducting electrolyte. Current devices use solutions of complex salts in organic solvents, leading to both toxicity and flammability concerns. These drawbacks can be avoided by replacing conventional electrolytes with room-temperature molten salts, known as ionic liquids (ILs). ILs are non-volatile, non-flammable, and offer high conductivity and good electrochemical stability. Device mass can be reduced by combining ILs with a solid scaffold material to form an "ionogel," further improving performance metrics. In this work, sol-gel chemistry is explored as a means of forming ionogel electrolytes. Sol-gel chemistry is a solution-based, industrially-relevant, well-studied technique by which solids such as silica can be formed in situ. Previous works used a simple acid-catalyzed sol-gel reaction to create brittle, glassy ionogels. Here, both the range of products that can be accomplished through sol-gel processing and the understanding of interactions between ILs and the sol-gel reaction network are greatly expanded. This work introduces novel ionogel materials, including soft and compliant silica-supported ionogels and PDMS-supported ionogels. The impacts of the reactive formulation, IL identity, and casting time are detailed. It is demonstrated that variations in formulation can lead to rapid gelation and open pore structures in the silica scaffold or slow gelation and more dense silica

  19. Trivalent chromium removal from aqueous solutions by a sol–gel synthesized silica adsorbent functionalized with sulphonic acid groups

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Gonzalez, Sergio Efrain [Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. Marcelino García Barragán # 1421, esq. Calzada Olímpica, C.P. 44430 Guadalajara, Jalisco (Mexico); Carbajal-Arizaga, Gregorio Guadalupe [Departamento de Química, CUCEI, Universidad de Guadalajara, Blvd. Marcelino García Barragán # 1421, esq. Calzada Olímpica, C.P. 44430 Guadalajara, Jalisco (Mexico); Manriquez-Gonzalez, Ricardo [Departamento de Madera, Celulosa y Papel, CUCEI, Universidad de Guadalajara, Km 15.5, carretera Guadalajara-Nogales, Las Agujas, C.P. 45020 Zapopan, Jalisco (Mexico); De la Cruz-Hernandez, Wencel [Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 carretera Tijuana-Ensenada, C.P. 22830 Ensenada, Baja California (Mexico); Gomez-Salazar, Sergio, E-mail: sergio.gomez@cucei.udg.mx [Departamento de Ingeniería Química, Universidad de Guadalajara, Blvd. Marcelino García Barragán # 1421, esq. Calzada Olímpica, C.P. 44430 Guadalajara, Jalisco (Mexico)

    2014-11-15

    Highlights: • Corpuscular sulphonic acid-functionalized silica holds improved uptake of chromium. • Mesopores on adsorbent facilitate (CH{sub 3}COO){sub 2}Cr{sup +} ion uptake on sulphonate sites. • Formation of chromium acetate sulphonate complex proposed from XPS results. • Fixed bed chromium uptake results suggest potential industrial use. - Abstract: A high capacity hybrid silica adsorbent was synthesized via sol–gel processing with sulphonic acid groups as trivalent chromium complex ions chelators from aqueous solutions. The synthesis included co-condensation of tetraethoxysilane (TEOS) with 3-(mercaptopropyl)trimethoxysilane (MPS), and oxidation of thiol to sulphonic acid groups. Chromium uptake kinetic, batch and fixed-bed experiments were performed to assess the removal of this metal from aqueous solutions. {sup 13}C, {sup 29}Si CPMAS NMR, FTIR, XPS were used to characterize the adsorbent structure and the nature of chromium complexes on the adsorbent surface. Chromium maximum uptake was obtained at pH 3 (72.8 mg/g). Elemental analysis results showed ligand density of 1.48 mmol sulphonic groups/g. About 407 mL of Cr(III) solution (311 mg/L) were treated to breakthrough point reaching ≤0.06 mg/L at the effluent. These results comply with USEPA regulation for chromium concentration in drinking water (≤0.1 mg/L). The adsorbent shows potential to be used in chromium separations to the industrial level.

  20. Trivalent chromium removal from aqueous solutions by a sol–gel synthesized silica adsorbent functionalized with sulphonic acid groups

    International Nuclear Information System (INIS)

    Gomez-Gonzalez, Sergio Efrain; Carbajal-Arizaga, Gregorio Guadalupe; Manriquez-Gonzalez, Ricardo; De la Cruz-Hernandez, Wencel; Gomez-Salazar, Sergio

    2014-01-01

    Highlights: • Corpuscular sulphonic acid-functionalized silica holds improved uptake of chromium. • Mesopores on adsorbent facilitate (CH 3 COO) 2 Cr + ion uptake on sulphonate sites. • Formation of chromium acetate sulphonate complex proposed from XPS results. • Fixed bed chromium uptake results suggest potential industrial use. - Abstract: A high capacity hybrid silica adsorbent was synthesized via sol–gel processing with sulphonic acid groups as trivalent chromium complex ions chelators from aqueous solutions. The synthesis included co-condensation of tetraethoxysilane (TEOS) with 3-(mercaptopropyl)trimethoxysilane (MPS), and oxidation of thiol to sulphonic acid groups. Chromium uptake kinetic, batch and fixed-bed experiments were performed to assess the removal of this metal from aqueous solutions. 13 C, 29 Si CPMAS NMR, FTIR, XPS were used to characterize the adsorbent structure and the nature of chromium complexes on the adsorbent surface. Chromium maximum uptake was obtained at pH 3 (72.8 mg/g). Elemental analysis results showed ligand density of 1.48 mmol sulphonic groups/g. About 407 mL of Cr(III) solution (311 mg/L) were treated to breakthrough point reaching ≤0.06 mg/L at the effluent. These results comply with USEPA regulation for chromium concentration in drinking water (≤0.1 mg/L). The adsorbent shows potential to be used in chromium separations to the industrial level

  1. Determination of the optical properties of PNIPAAm gels used in biological applications

    CSIR Research Space (South Africa)

    Singh, A

    2009-07-01

    Full Text Available Poly(N-isopropylacrylamide) that is PNIPAAm is a temperature sensitive smart material which displays a lower critical solution temperature (LCST) at 33-35oC. At the lower critical solution temperature, the gel changes from hydrophilic to hydrophobic...

  2. Role of the plasma membrane H(+)-ATPase in the regulation of organic acid exudation under aluminum toxicity and phosphorus deficiency.

    Science.gov (United States)

    Yu, Wenqian; Kan, Qi; Zhang, Jiarong; Zeng, Bingjie; Chen, Qi

    2016-01-01

    Aluminum (Al) toxicity and phosphorus (P) deficiency are 2 major limiting factors for plant growth and crop production in acidic soils. Organic acids exuded from roots have been generally regarded as a major resistance mechanism to Al toxicity and P deficiency. The exudation of organic acids is mediated by membrane-localized OA transporters, such as ALMT (Al-activated malate transporter) and MATE (multidrug and toxic compound extrusion). Beside on up-regulation expression of organic acids transporter gene, transcriptional, translational and post-translational regulation of the plasma membrane H(+)-ATPase are also involved in organic acid release process under Al toxicity and P deficiency. This mini-review summarizes the current knowledge about this field of study on the role of the plasma membrane H(+)-ATPase in organic acid exudation under Al toxicity and P deficiency conditions.

  3. Role of alkyl alcohol on viscosity of silica-based chemical gels for decontamination of highly radioactive nuclear facilities

    International Nuclear Information System (INIS)

    Choi, B. S.; Yoon, S. B.; Jung, C. H.; Lee, K. W.; Moon, J. K.

    2012-01-01

    Silica-based chemical gel for the decontamination of nuclear facilities was prepared by using fumed silica as a viscosifier, a 0.5 M Ce (IV) solution dissolved in concentrated nitric acid as a chemical decontamination agent, and tripropylene glycol butyl ether (TPGBE) as a co-viscosifier. A new effective strategy for the preparation of the chemical gel was investigated by introducing the alkyl alcohols as organic solvents to effectively dissolve the co-viscosifier. The mixture solution of the co-viscosifier and alkyl alcohols was more effective in the control of viscosity than that of the co-viscosifier only in gel. Here, the alkyl alcohols played a key role as an effective dissolution solvent for the co-viscosifier in the preparation of the chemical gel, resulting in a reducing of the amount of the co-viscosifier and gel time compared with that of the chemical gel prepared without the alkyl alcohols. It was considered that the alkyl alcohols contributed to the effective dissolution of the co-viscosifier as well as the homogeneous mixing in the formation of the gel, while the co-viscosifier in an aqueous media of the chemical decontamination agent solution showed a lower solubility. The decontamination efficiency of the chemical gels prepared in this work using a multi-channel analyzer (MCA) showed a high decontamination efficiency of over ca. 94% and ca. 92% for Co-60 and Cs-137 contaminated on surface of the stainless steel 304, respectively. (authors)

  4. Preparation of YBa2Cu3O7-x superconducting solutions and films from alkoxide-based precursors using sol-gel method and investigation of their chemical reaction mechanisms

    International Nuclear Information System (INIS)

    Mutlu, Ibrahim Halil; Acun, Hediye; Celik, Erdal; Turkmen, Hasan

    2007-01-01

    In the development of coated superconductors sol-gel technique has been widely used as an effective processing method, especially in making long-length wires and tapes. However, one drawback associated with the deposition of YBa 2 Cu 3 O 7-x and Gd 2 O 3 buffer layer on Ni tape is the adhesion characteristic at interfaces YBCO-Gd 2 O 3 and Gd 2 O 3 -NiO and NiO-Ni substrate. In this paper, two strategies for adhesion enhancement of multilayered ceramic oxide coatings on Ni substrate were proposed: (1) formation of chemical bonds through surface condensation reactions, and development of ceramic networks through diffusion of alkoxide precursors. The current research has focused on the fabrication and adhesion of YBCO coatings on buffered Ni substrate using nine solutions prepared from Y, Ba and Cu alkoxides, solvent and chelating agent. Only two of YBCO solutions were successfully obtained while the rest of them were unsuccessful. Among these solutions we scrutinized chemical reaction mechanisms of a successful and an unsuccessful solution for comparison. How the chemical bonds and solubility were affected by the acids, base and solvents used in the solutions was demonstrated. It was shown that pH of the solution, homogeneity of the solution and gelation, steric affect of the chemicals in sol-gel solutions are significant issues to obtain high quality superconducting YBCO thin films. In addition, X-ray diffraction (XRD) was used to analyze phase structure of YBCO and compare results of chemical reactions obtained by a chemdraw programme. Scanning electron microscope (SEM) studies was carried out to examine microstructures of YBCO films produced from alkoxide precursors, solvent, chelating agent and modifying liquid chemical materials such as triethanolamine or ammonium hydroxide. It was found to be YBCO, Gd 2 O 3 , NiO and Ni phases in YBCO/Gd 2 O 3 /Ni sample from XRD analysis. That the solution prepared by using triethanolamine provided the best film quality and

  5. Standardization of the Fricke gel dosimetry method and tridimensional dose evaluation using the magnetic resonance imaging technique

    International Nuclear Information System (INIS)

    Cavinato, Christianne Cobello

    2009-01-01

    This study standardized the method for obtaining the Fricke gel solution developed at IPEN. The results for different gel qualities used in the preparation of solutions and the influence of the gelatin concentration in the response of dosimetric solutions were compared. Type tests such as: dose response dependence, minimum and maximum detection limits, response reproducibility, among others, were carried out using different radiation types and the Optical Absorption (OA) spectrophotometry and Magnetic Resonance (MR) techniques. The useful dose ranges for Co 60 gamma radiation and 6 MeV photons are 0,4 to 30,0 Gy and 0,5 to 100,0 Gy , using OA and MR techniques, respectively. A study of ferric ions diffusion in solution was performed to determine the optimum time interval between irradiation and samples evaluation; until 2,5 hours after irradiation to obtain sharp MR images. A spherical simulator consisting of Fricke gel solution prepared with 5% by weight 270 Bloom gelatine (national quality) was developed to be used to three-dimensional dose assessment using the Magnetic Resonance Imaging (MRI) technique. The Fricke gel solution prepared with 270 Bloom gelatine, that, in addition to low cost, can be easily acquired on the national market, presents satisfactory results on the ease of handling, sensitivity, response reproducibility and consistency. The results confirm their applicability in the three-dimensional dosimetry using MRI technique. (author)

  6. Chemical modification of silica gel with synthesized Schiff base hydrazone derivative and application for preconcentration and separation of U(VI) ions from aqueous solutions

    International Nuclear Information System (INIS)

    Gamze Karayel Incili; Gul Asiye Aycik

    2014-01-01

    Schiff base hydrazone derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of U(VI) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, Schiff base hydrazone derivative (HL) was chemically bonded to silica gel surface immobilized 3-aminopropyl trimethoxysilane, then analyzed by Fourier transform infrared, Brunauer-Emmett-Teller, scanning electron microscopy and elemental analysis. The influence of the solution pH, amount of sorbent, contact time, temperature, foreign ion effect and initial U(VI) concentration was investigated. The maximum U(VI) uptake capacity was found to be 8.46 mg/g. (author)

  7. Fibril formation from pea protein and subsequent gel formation.

    Science.gov (United States)

    Munialo, Claire Darizu; Martin, Anneke H; van der Linden, Erik; de Jongh, Harmen H J

    2014-03-19

    The objective of this study was to characterize fibrillar aggregates made using pea proteins, to assemble formed fibrils into protein-based gels, and to study the rheological behavior of these gels. Micrometer-long fibrillar aggregates were observed after pea protein solutions had been heated for 20 h at pH 2.0. Following heating of pea proteins, it was observed that all of the proteins were hydrolyzed into peptides and that 50% of these peptides were assembled into fibrils. Changes on a structural level in pea proteins were studied using circular dichroism, transmission electron microscopy, and particle size analysis. During the fibril assembly process, an increase in aggregate size was observed, which coincided with an increase in thioflavin T binding, indicating the presence of β-sheet aggregates. Fibrils made using pea proteins were more branched and curly. Gel formation of preformed fibrils was induced by slow acidification from pH 7.0 to a final pH of around pH 5.0. The ability of pea protein-based fibrillar gels to fracture during an amplitude sweep was comparable to those of soy protein and whey protein-based fibrillar gels, although gels prepared from fibrils made using pea protein and soy protein were weaker than those of whey protein. The findings show that fibrils can be prepared from pea protein, which can be incorporated into protein-based fibrillar gels.

  8. Improving transport container design to reduce broiler chicken PSE (pale, soft, exudative) meat in Brazil.

    Science.gov (United States)

    Spurio, Rafael S; Soares, Adriana L; Carvalho, Rafael H; Silveira Junior, Vivaldo; Grespan, Moisés; Oba, Alexandre; Shimokomaki, Massami

    2016-02-01

    Throughout the chicken production chain, transport from farm to the commercial abattoir is one of the most critical sources of stress, particularly heat stress. The aim of this work was to describe the performance of a new prototype truck container designed to improve the microenvironment and reduce the incidence of pale, soft and exudative (PSE) meat and dead on arrival (DOA) occurrences. Experiments were carried out for four different conditions: regular and prototype truck, both with and without wetting loaded cages at the farm (for bird thermal stress relief) just before transporting. While there was no difference in the DOA index (P ≥ 0.05), the prototype truck caused a reduction (P < 0.05) in the occurrence of PSE meat by 66.3% and 49.6% with and without wetting, respectively. The results of this experiment clearly revealed a low-cost solution for transporting chickens that yields better animal welfare conditions and improves meat quality. © 2015 Japanese Society of Animal Science.

  9. Measurement of Mechatronic Property of Biological Gel with Micro-Vibrating Electrode at Ultrasonic Frequency

    Directory of Open Access Journals (Sweden)

    Shigehiro Hashimoto

    2008-10-01

    Full Text Available A measurement system has been designed with a micro-vibrating electrode at ultrasonic frequency to measure local impedance of biological gel in vitro. The designed system consists of two electrodes, where one of the electrodes vibrates with a piezoelectric actuator. The component of variation at impedance between two electrodes with vibration of one electrode is analyzed at the corresponding spectrum. The manufactured system was applied to measure impedance of a physiological saline solution, a potassium chloride solution, a dextran aqueous solution, and an egg. The experimental results show that the designed system is effective to measure local mechatronic property of biological gel.

  10. Sol-Gel Process for Making Pt-Ru Fuel-Cell Catalysts

    Science.gov (United States)

    Narayanan, Sekharipuram; Valdez, Thomas; Kumta, Prashant; Kim, Y.

    2005-01-01

    A sol-gel process has been developed as a superior alternative to a prior process for making platinum-ruthenium alloy catalysts for electro-oxidation of methanol in fuel cells. The starting materials in the prior process are chloride salts of platinum and ruthenium. The process involves multiple steps, is time-consuming, and yields a Pt-Ru product that has relatively low specific surface area and contains some chloride residue. Low specific surface area translates to incomplete utilization of the catalytic activity that might otherwise be available, while chloride residue further reduces catalytic activity ("poisons" the catalyst). In contrast, the sol-gel process involves fewer steps and less time, does not leave chloride residue, and yields a product of greater specific area and, hence, greater catalytic activity. In this sol-gel process (see figure), the starting materials are platinum(II) acetylacetonate [Pt(C5H7O2)2, also denoted Pt-acac] and ruthenium(III) acetylacetonate [Ru(C5H7O2)3, also denoted Ru-acac]. First, Pt-acac and Ru-acac are dissolved in acetone at the desired concentrations (typically, 0.00338 moles of each salt per 100 mL of acetone) at a temperature of 50 C. A solution of 25 percent tetramethylammonium hydroxide [(CH3)4NOH, also denoted TMAH] in methanol is added to the Pt-acac/Ruacac/ acetone solution to act as a high-molecular-weight hydrolyzing agent. The addition of the TMAH counteracts the undesired tendency of Pt-acac and Ru-acac to precipitate as separate phases during the subsequent evaporation of the solvent, thereby helping to yield a desired homogeneous amorphous gel. The solution is stirred for 10 minutes, then the solvent is evaporated until the solution becomes viscous, eventually transforming into a gel. The viscous gel is dried in air at a temperature of 170 C for about 10 hours. The dried gel is crushed to make a powder that is the immediate precursor of the final catalytic product. The precursor powder is converted to the

  11. Sol-gel coatings on large area glass sheets for electrochromic devices

    NARCIS (Netherlands)

    Vroon, Z.A.E.P.; Spee, C.I.M.A.

    1997-01-01

    The preparation of vanadium and tungsten oxide coatings is described using vanadium oxide tri-2-propoxide/2-propanol and tungsten penta-ethoxide/2-propanol solutions. These solutions are dip coated onto K-glass substrates and cured. For vanadium oxide coatings it is shown that sol-gel/dip coat

  12. Antiprotozoal and Antiglycation Activities of Sesquiterpene Coumarins from Ferula narthex Exudate

    Directory of Open Access Journals (Sweden)

    Adnan Amin

    2016-09-01

    Full Text Available The exudate of Ferula narthex Boiss. (Apiaceae is widely used in the Indian subcontinent as a spice and because of its health effects. Six sesquiterpene coumarins have been isolated from this exudate: feselol, ligupersin A, asacoumarin A, 8′-O-acetyl-asacoumarin A, 10′R-karatavacinol and 10′R-acetyl-karatavacinol. Based on its use in infectious and diabetic conditions, the isolated constituents were evaluated for antimicrobial and antiglycation activities. Some compounds showed activity against protozoal parasites, asacoumarin A being the most active one against Plasmodium falciparum K1 (IC50 1.3 μM. With regard to antiglycation activity, in the BSA-glucose test, ligupersin A displayed the highest activity (IC50 0.41 mM, being more active than the positive control aminiguanidine (IC50 1.75 mM. In the BSA-MGO assay, the highest activity was shown by 8′-O-acetyl-asacoumarin A (IC50 1.03 mM, being less active than aminoguanidine (IC50 0.15 mM. Hence, the antiglycation activity of the isolated constituents was due to both oxidative and non-oxidative modes of inhibition.

  13. Linkage and candidate gene analysis of X-linked familial exudative vitreoretinopathy.

    Science.gov (United States)

    Shastry, B S; Hejtmancik, J F; Plager, D A; Hartzer, M K; Trese, M T

    1995-05-20

    Familial exudative vitreoretinopathy (FEVR) is a hereditary eye disorder characterized by avascularity of the peripheral retina, retinal exudates, tractional detachment, and retinal folds. The disorder is most commonly transmitted as an autosomal dominant trait, but X-linked transmission also occurs. To initiate the process of identifying the gene responsible for the X-linked disorder, linkage analysis has been performed with three previously unreported three- or four-generation families. Two-point analysis showed linkage to MAOA (Zmax = 2.1, theta max = 0) and DXS228 (Zmax = 0.5, theta max = 0.11), and this was further confirmed by multipoint analysis with these same markers (Zmax = 2.81 at MAOA), which both lie near the gene causing Norrie disease. Molecular genetic analysis further reveals a missense mutation (R121W) in the third exon of the Norrie's disease gene that perfectly cosegregates with the disease through three generations in one family. This mutation was not detected in the unaffected family members and six normal unrelated controls, suggesting that it is likely to be the pathogenic mutation. Additionally, a polymorphic missense mutation (H127R) was detected in a severely affected patient.

  14. Synthesis of hydroxyapatite nanopowders by sol–gel emulsion ...

    Indian Academy of Sciences (India)

    Administrator

    gel emulsion technique, where the sol (water medium) is emulsified, in a support ... The sol was prepared by mixing a 2 M solution of calcium acetate dissolved in ... powder using a punch and die set and a KBr press (model. M-15) with a ...

  15. ACUTE EXUDATIVE PARANEOPLASTIC POLYMORPHOUS VITELLIFORM MACULOPATHY DURING VEMURAFENIB AND PEMBROLIZUMAB TREATMENT FOR METASTATIC MELANOMA.

    Science.gov (United States)

    Sandhu, Harpal S; Kolomeyer, Anton M; Lau, Marisa K; Shields, Carol L; Schuchter, Lynn M; Nichols, Charles W; Aleman, Tomas S

    2017-06-13

    To describe a patient with BRAF mutation-positive cutaneous melanoma who developed acute exudative polymorphous vitelliform maculopathy during vemurafenib and pembrolizumab treatment for metastatic melanoma. Retrospective case report documented with wide-field fundus imaging, spectral domain optical coherence tomography, and fundus autofluorescence imaging. A 55-year-old woman with bilateral ductal breast carcinoma and BRAF mutation-positive metastatic cutaneous melanoma complained of bilateral blurred vision within 5 days of starting vemurafenib (BRAF inhibitor). She had been on pembrolizumab (program death receptor antibody) and intermittently on dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor), and had a normal ophthalmologic examination. On presentation three weeks after the introduction of vemurafenib, her visual acuity had declined to 20/40 in both eyes. Her examination showed diffuse elevation of the fovea with multifocal yellow-white, crescent-shaped subretinal deposits within the macula of both eyes and bilateral neurosensory retinal detachments by spectral domain optical coherence tomography. Discontinuation of vemurafenib and introduction of difluprednate and dorzolamide led to a gradual resolution (over four months) of the neurosensory detachments with recovery of vision. This case report suggests that acute exudative polymorphous vitelliform maculopathy may be directly associated with the use of BRAF inhibitors as treatment for metastatic cutaneous melanoma, or indirectly by triggering autoimmune-paraneoplastic processes. Future identification of similar associations is required to unequivocally link vemurafenib and/or pembrolizumab to acute exudative polymorphous vitelliform maculopathy in metastatic melanoma.

  16. Phytochemical screening of the exudate of Aloe otallensis and its effect on Leishmania donovani

    Directory of Open Access Journals (Sweden)

    Zerihun Tesfaye Nigusse

    2016-06-01

    Full Text Available Objective: To evaluate the antileishmanial activity of methanolic extract of Aloe otallensis (A. otallensis on the promastigote stage of Leishmania donovani (L. donovani as compared to standard drugs and to screen its phytochemical constituents. Methods: Phytochemical screening was done by using the method mentioned by Evans and Trease on methanolic extract of the exudates of Aloe otallensis leaves. The extract was also evaluated for in vitro antileishmanial activity against L. donavani which is found from the Parasitology Unit of Black Lion Hospital. The result was compared to standard drugs of sodium stibogluconate, milfostin and paramomycin. Results: The extract has a good antileishmanial activity with an IC50 of 0.1230 μg/mL on L. donovani (AM 563. The experimental data showed that relatively it had better activity than paramomycin and milfostin but less activity than sodium stibogluconate. The data analyses were done by GraphPad Prism version 5 software after it was read by ELISA reader at the wave length of 650 nm. The phytochemical screening of the exudates of A. otallensis showed the presence of phenol, alkaloid and saponin. Conclusions: The methanol extract of the exudates of A. otallensis has a good antileishmaniasis activity and this may be attributed to phenol, alkaloid and saponin present in the plant. But it needs further analysis for the conformation of which constituent presents in high concentration to know which one has the strongest effect.

  17. Diffusion-weighted MR imaging of pleural fluid: differentiation of transudative vs exudative pleural effusions

    International Nuclear Information System (INIS)

    Baysal, T.; Bulut, T.; Dusak, A.; Dogan, M.; Goekirmak, M.; Kalkan, S.

    2004-01-01

    The aim of this study was to evaluate the ability of diffusion-weighted MRI in differentiating transudative from exudative pleural effusions. Fifty-seven patients with pleural effusion were studied. Diffusion-weighted imaging (DWI) was performed with an echo-planar imaging (EPI) sequence (b values 0, 1000 s/mm 2 ) in 52 patients. The apparent diffusion coefficient (ADC) values were reconstructed from three different regions. Subsequently, thoracentesis was performed and the pleural fluid was analyzed. Laboratory results revealed 20 transudative and 32 exudative effusions. Transudates had a mean ADC value of 3.42±0.76 x 10 -3 mm 2 /s. Exudates had a mean ADC value of 3.18±1.82 x 10 -3 mm 2 /s. The optimum cutoff point for ADC values was 3.38 x 10 -3 mm 2 /s with a sensitivity of 90.6% and specificity of 85%. A significant negative correlation was seen between ADC values and pleural fluid protein, albumin concentrations and lactate dehydrogenase (LDH) measurements (r=-0.69, -0.66, and -0.46, respectively; p<0.01). The positive predictive value, negative predictive value, and diagnostic accuracy of ADC values were determined to be 90.6, 85, and 88.5%, respectively. The application of diffusion gradients to analyze pleural fluid may be an alternative to the thoracentesis. Non-invasive characterization of a pleural effusion by means of DWI with single-shot EPI technique may obviate the need for thoracentesis with its associated patient morbidity. (orig.)

  18. Preparation of gold nanoparticles-agarose gel composite and its application in SERS detection

    Science.gov (United States)

    Ma, Xiaoyuan; Xia, Yu; Ni, Lili; Song, Liangjing; Wang, Zhouping

    2014-03-01

    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Nanocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nanocomposites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules (NBA, MBA, 1NAT). Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal. Furthermore, the gel could be cleaned with washing solution and recycling could be achieved for Raman detection.

  19. Effect of Normothermic and Cold Eye Irrigation Solution (BSS and Viscoelastic Gel on the Consumption of Sedative Drugs in Phacoemulsification Cataract Surgery

    Directory of Open Access Journals (Sweden)

    Mojtaba Rahimi Varposhti

    2017-11-01

    Full Text Available Abstract Background: This study aimed to compare the effect of cold eye irrigation solution (BSS and viscoelastic gel with their combination in room temperature on the dosage of sedative drugs which we use in Phacoemulsification cataract surgery. Material and Methods: 190 patients scheduled for cataract surgery under sedation were randomly divided into two equal groups. During surgery, we used cold (4ºc and warm (room temperature BSS and viscoelastic gel in the first and second group respectively. For all patients, we started sedation with Midazolam and Fentanyl and in case that we needed additional drug, we used Sodium Thiopental till we reached desired sedation level. Ramsay sedation scores (before, during and after surgery and total sedative drug consumption were evaluated and compared between two groups and at the end of the surgery, we checked and recorded the satisfaction score of patients and surgeon about the quality of sedation. Results: The average dosage of Midazolam wasn’t significantly different between two groups, while the average dosage of Sodium Thiopental was significantly lower in cold group. Also, the average time on which we reached desired Ramsay sedation score and the level of Ramsay score were significantly different between two groups. Conclusion: Using cold BSS and viscoelastic gel in cataract surgery in comparison of their combination in room temperature will reduce the dosage of sedative drugs which we use during surgery and help us getting a more effective sedation and higher patient and surgeon satisfaction.

  20. A modified {sup 99} Mo- {sup 99} Tc generator on Zirconium molybdo- phosphate-{sup 99} Mo gel. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    El-Kolaly, M T; Talaat, H [Labelled Compounds Department, Cairo (Egypt); Botros, N [Radioistspe and Generator Department, Radioisotope Production and Sealed Source Division, Hot Laboratories Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    A modified {sup 99} Mo - {sup 99} Tc gel generator is described. The new generator is based on the use of zirconium molybdophosphate - {sup 99} Mo gel in which {sup 99} Mo chemically combined in the gel structure, where {sup 99m}Tc can be easily eluted with distilled water or saline. The gel was prepared via chemical reaction between zirconyl chloride and molybdophosphate - {sup 99} Mo solution. The PH of the reaction mixture was adjusted with NaOH. Different gels have been prepared by varying the molar ratio of Mo:Zr:p. The PH and time of digeston on complete gel formation was also investigated in order to optimize the condition of gel preparation. Molybdophosphate {sup 32} P solution was used to determine the phosphorous content in the gel and in the {sup 99m}Tc eluate. The temperature and time of drying of the gel and their effect on {sup 99m}Tc elution efficiency were also studied. From the data obtained, the optimum conditions for routine production of {sup 99} Mo - {sup 99m}Tc generator are presented and discussed. 2 figs., 6 tabs.

  1. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by sol-gel process

    Science.gov (United States)

    Bansal, Narottam P.

    1990-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water:TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, x ray diffraction, surface area and pore size distribution measurements.

  2. Rheological study of a gel-forming precursor for superconducting YBa2Cu3O/sub 7-//sub x/

    International Nuclear Information System (INIS)

    Khan, S.A.; Barboux, P.; Bagley, B.G.; Tarascon, J.M.

    1988-01-01

    Rheological measurements are used to monitor the sol-gel behavior of a superconducting precursor. A precursor made with an aged yttrium component [Y(OH) 3 ] has a much higher elastic modulus (G') and complex viscosity (eta*) but the same loss modulus (G'') compared to that made with a fresher yttrium solution. The G''/G' ratio is less than unity for the older solution but greater than 1 for the fresher sample, indicating that the former solution has a more gel-like character. The high viscosity sample gives better fired thick-film superconducting properties but has a shorter shelf life. Measurements on yttrium components of different age show differences in viscosity and G''/G' which correlate with the behavior of the oxide precursors. Reshearing the precursor solution at any stage during its gelation process can cause irreversible changes in the gel structure

  3. Influence of cadmium stress on root exudates of high cadmium accumulating rice line (Oryza sativa L.).

    Science.gov (United States)

    Fu, Huijie; Yu, Haiying; Li, Tingxuan; Zhang, Xizhou

    2018-04-15

    A hydroponic experiment with two different cadmium (Cd) accumulating rice lines of Lu527-8 (the high Cd accumulating rice line) and Lu527-4 (the normal rice line) was carried out to explore the links among Cd stress, root exudates and Cd accumulation. The results showed that (1) Cd stress increased quantities of organic acids, but had no effect on composition in root exudates of the two rice lines. In Cd treatments, the contents of every detected organic acid in root exudates of Lu527-8 were 1.76-2.43 times higher than those of Lu527-4. Significant positive correlations between organic acids contents and Cd contents in plants were observed in both rice lines, except that malic acid was only highly relevant to Lu527-8, but not to Lu527-4. (2) Both composition and quantities of amino acids in root exudates changed a lot under Cd stress and this change differed in two rice lines. In control, four amino acids (glutamic acid, glycine, tyrosine and histidine) were detected in two rice lines. Under Cd stress, eight amino acids in Lu527-8 and seven amino acids in Lu527-4 could be detected, among which phenylalanine was only secreted by Lu527-8 and alanine, methionine and lysine were secreted by both rice lines. The contents of those four newly secreted amino acids from Lu527-8 increased significantly with the increase of Cd dose and each had a high-positive correlation with Cd contents, but the same change did not appear in Lu527-4. The difference between two rice lines in secretion of organic acids and amino acids may be related to their different Cd uptake properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. New sesquiterpene lactones from sunflower root exudate as germination stimulants for Orobanche cumana.

    Science.gov (United States)

    Raupp, Frank M; Spring, Otmar

    2013-11-06

    Orobanche cumana is a serious threat for cultivation of sunflower in Europe and Asia. Germination of the parasite is induced by metabolites released from the host root system. The first germination stimulant from sunflower root exudate was recently identified as dehydrocostus lactone, a sesquiterpene lactone. Bioassay-guided fractionation of root exudates now showed the release of additional sesquiterpene lactones. Besides dehydrocostus lactone, costunolide, tomentosin, and 8-epixanthatin were purified and identified spectroscopically. All four compounds induced germination of O. cumana at nano- to micromolar concentrations. Costunolide and dehydrocostus lactone concentrations above 1 μM reduced the activity, and application of 100 μM inhibited germination irreversibly. Seeds of Phelipanche ramosa could not be induced with costunolide. O. cumana seeds also germinated with GR24, a synthetic strigolactone. No bioactive fraction of sunflower contained compounds of this type. This supports previous findings that sesquiterpene lactones instead of strigolactones trigger the sunflower/O. cumana interaction.

  5. Role of the plasma membrane H+-ATPase in the regulation of organic acid exudation under aluminum toxicity and phosphorus deficiency

    Science.gov (United States)

    Yu, Wenqian; Kan, Qi; Zhang, Jiarong; Zeng, Bingjie; Chen, Qi

    2016-01-01

    Aluminum (Al) toxicity and phosphorus (P) deficiency are 2 major limiting factors for plant growth and crop production in acidic soils. Organic acids exuded from roots have been generally regarded as a major resistance mechanism to Al toxicity and P deficiency. The exudation of organic acids is mediated by membrane-localized OA transporters, such as ALMT (Al-activated malate transporter) and MATE (multidrug and toxic compound extrusion). Beside on up-regulation expression of organic acids transporter gene, transcriptional, translational and post-translational regulation of the plasma membrane H+-ATPase are also involved in organic acid release process under Al toxicity and P deficiency. This mini-review summarizes the current knowledge about this field of study on the role of the plasma membrane H+-ATPase in organic acid exudation under Al toxicity and P deficiency conditions. PMID:26713714

  6. Ceramic protective coatings applied by sol-gel or electrophoresis

    International Nuclear Information System (INIS)

    Stoch, A.

    1993-01-01

    Sol-gel and electrophoresis are the complementary techniques which may be used for obtaining the ceramic coatings. The composition of such a coatings depends on the composition of electrophoresis bath or sol solution. Thermal treatment is used for densifying the coating and promoting the adherence of coating to the substrate. In presented work silica, silica-alumina or alumina coatings are applied by sol-gel dip coating procedure on steel, aluminium or ceramic substrates. Electrophoresis is employed for obtaining zirconia, alumina or hydroxyapatite coatings on stainless steel. (author). 7 refs

  7. Effect of dental adhesives on the exudative phase of the inflammatory process in subcutaneous tissue of rats

    Directory of Open Access Journals (Sweden)

    Nagem-Filho Halim

    2003-01-01

    Full Text Available The vascular changes in the subcutaneous connective tissue of rats induced by dentin bonding systems (one step was studied and compared to those induced by saline solution (negative control and Furacin (positive control, during the exudative phase of the inflammatory process. Twenty mg/kg of Evan's blue were injected intravenously in the vein of the rats' penises; 0.1 ml of each substance tested was inoculated in the subcutaneous tissue. After a 3 hour period the animals were sacrificed and their skins were excised and punched out with a standard steel 2.5 cm in diameter. The specimens were immediately immersed in 8 ml of formamide and taken to a double boiler for 72 hours at 37ºC, to remove the dye. The liquid containing the overflowed dye was filtered, analyzed in the spectrophotometer (620 nm and classified according to the criteria established by Nagem-Filho, Pereira (1976. After statistical analysis, the irritative potential of the substances was ranked as follows: Furacin (severe > Single Bond and Bond 1 (moderate - no significant differences between the dentin bonding systems tested > saline solution (not significant as regards the irritation degree.

  8. One step aqueous solution preparation of nanosize iron-doped tin oxide from SnO{sub 2}.xH{sub 2}O gel

    Energy Technology Data Exchange (ETDEWEB)

    Melghit, Khaled [Chemistry Department, College of Science, P.O. Box 36, Al-Khodh 123, Sultan Qaboos University (Oman)]. E-mail: melghit@squ.edu.om; Bouziane, Khalid [Physics Department, College of Science, P.O. Box 36, Al-Khodh 123, Sultan Qaboos University (Oman)

    2006-03-15

    Nanosized iron-doped tin oxide solid solution was prepared by mixing tin oxide gel SnO{sub 2}.xH{sub 2}O with a boiling solution of iron nitrate. The XRD data of the as-prepared and annealed sample at 773 K show that the patterns are indexed to the rutile phase without any trace of an extra phase. SEM and TEM results performed on different selected area of the samples reveal a homogeneous composition of 8 at.% of Fe content and a size of about 2 nm of the particles. The particles size was found to increase slightly with temperature; about 7 nm after 24 h at 773 K. Structural and magnetic results seem to indicate that Fe{sup 3+} substitute for Sn{sup 4+} on the as-prepared sample. The system presents some weak ferromagnetic character at room temperature.

  9. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    De Deene, Y; De Wagter, C; Van Duyse, B; Achten, E; De Neve, W [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J [Ghent Univ. (Belgium). Dept. of Magnetic Resonance

    1995-12-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.

  10. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W.; De Poorter, J.

    1995-01-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes

  11. Quality change of apple slices coated with Aloe vera gel during storage.

    Science.gov (United States)

    Song, Hye-Yeon; Jo, Wan-Shin; Song, Nak-Bum; Min, Sea C; Song, Kyung Bin

    2013-06-01

    Fresh-cut apples are easily susceptible to browning and microbial spoilage. In this study, an edible coating prepared from Aloe vera gel containing antibrowning solution was applied to preserve the quality of fresh-cut apples during storage. Fresh-cut apples were treated with both an Aloe vera gel and an Aloe vera gel containing 0.5% cysteine and then stored at 4 °C for 16 d. The color, firmness, weight loss, soluble solid content, titratable acidity, microbial analysis, and sensory evaluation were analyzed during storage. Fresh-cut apples coated with the Aloe vera gel showed delayed browning and reduced weight loss and softening compared to the control. The Aloe vera gel coating was also effective in reducing the populations of the total aerobic bacteria and yeast and molds. In particular, Aloe vera gel containing 0.5% cysteine was most effective in delaying browning and the reduction of microbial populations among the treatments. These results suggest that an Aloe vera gel coating can be used for maintaining the quality of fresh-cut apples. © 2013 Institute of Food Technologists®

  12. Alkaline sodium borohydride gel as a hydrogen source for PEMFC or an energy carrier for NaBH 4-air battery

    Science.gov (United States)

    Liu, B. H.; Li, Z. P.; Chen, L. L.

    In this preliminary study, we tried to use sodium polyacrylate as the super absorbent polymer to form alkaline NaBH 4 gel and explored its possibilities for borohydride hydrolysis and borohydride electro-oxidation. It was found that the absorption capacity of sodium polyacrylate decreased with increasing NaBH 4 concentration. The formed gel was rather stable in the sealed vessel but tended to slowly decompose in open air. Hydrogen generation from the gel was carried out using CoCl 2 catalyst precursor solutions. Hydrogen generation rate from the alkaline NaBH 4 gel was found to be higher and impurities in hydrogen were less than that from the alkaline NaBH 4 solution. The NaBH 4 gel also successfully powered a NaBH 4-air battery.

  13. Silica gel matrix immobilized Chlorophyta hydrodictyon africanum ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-08-05

    Aug 5, 2015 ... The algae-silica gel adsorbent was used for batch sorption studies of a cationic dye, ... traditional methods of treating industrial effluent, these ... Author(s) agree that this article remains permanently open access under the terms of the Creative ... sodium silicate solution (v/v) and 25 mL of distilled water. With.

  14. [The role of gastroesophageal reflux disease in the development of chronic exudative otitis media in the children during the first year of life].

    Science.gov (United States)

    Rakhmanova, I V; Soldatsky, Yu L; Matroskin, A G; Marenich, N S; Shelamova, V N

    2018-01-01

    The objective of the present study was the determination of the incidence of gastroesophageal reflux disease and the evaluation of its possible influence on the development and duration of chronic exudative otitis media in the children during the first year of life. A total of 141 infants at the age of 3 months presenting with exudative otitis media refractory to the conservative treatment throughout the first 1-1.5 months of life were available for the examination. The effectiveness of the anti-reflux therapy was estimated based on the middle ear condition (the presence or absence of exudate) within 3 and 6 months after the initiation of the treatment. The signs of aspiration of gastric chimus and gastroesophageal reflux disease were documented in 92% of the cases. The anti-reflux treatment during 3 months resulted in the disappearance of the manifestations of exudative otitis media in 43% of the patients. The further prolongation of such therapy up to 6 months allowed to normalize the state of the middle ear in 69% of the children although the remaining 40% failed to respond. It is concluded that the treatment of the children presenting with exudative otitis media during first year of life should be performed taking into consideration the possible involvement of gastroesophageal reflux disease in pathogenesis of this pathological condition.

  15. The amino acid distribution in rachis xylem sap and phloem exudate of Vitis vinifera 'Cabernet Sauvignon' bunches.

    Science.gov (United States)

    Gourieroux, Aude M; Holzapfel, Bruno P; Scollary, Geoffrey R; McCully, Margaret E; Canny, Martin J; Rogiers, Suzy Y

    2016-08-01

    Amino acids are essential to grape berry and seed development and they are transferred to the reproductive structures through the phloem and xylem from various locations within the plant. The diurnal and seasonal dynamics of xylem and phloem amino acid composition in the leaf petiole and bunch rachis of field-grown Cabernet Sauvignon are described to better understand the critical periods for amino acid import into the berry. Xylem sap was extracted by the centrifugation of excised leaf petioles and rachises, while phloem exudate was collected by immersing these structures in an ethylenediaminetetraacetic acid (EDTA) buffer. Glutamine and glutamic acid were the predominant amino acids in the xylem sap of both grapevine rachises and petioles, while arginine and glycine were the principal amino acids of the phloem exudate. The amino acid concentrations within the xylem sap and phloem exudate derived from these structures were greatest during anthesis and fruit set, and a second peak occurred within the rachis phloem at the onset of ripening. The concentrations of the amino acids within the phloem and xylem sap of the rachis were highest just prior to or after midnight while the flow of sugar through the rachis phloem was greatest during the early afternoon. Sugar exudation rates from the rachis was greater than that of the petiole phloem between anthesis and berry maturity. In summary, amino acid and sugar delivery through the vasculature to grape berries fluctuates over the course of the day as well as through the season and is not necessarily related to levels near the source. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Sequential determination of urea and HMTA in the process solution of sol-gel route of advanced nuclear fuel fabrication

    International Nuclear Information System (INIS)

    Sawant, R.M.; Chaudhuri, N.K.; Ramakumar, K.L.

    2002-01-01

    Determinations of hexamethylene tetramine (HMTA) and urea in the process solutions are required to optimize their concentrations for obtaining high quality ceramic oxide microspheres, for monitoring the washing procedure and for their subsequent recovery, recycling or waste disposal. Determination of urea is the feed solution by conventional procedures is difficult as it contains HMTA. It is more so in the effluent as it contains hydrolytic products like formaldehyde, methylol derivatives of urea, ammonium nitrate and ammonium hydroxide used for washing the gel microspheres. A derivative potentiometric method using a microprocessor-based autotitrator is described. Peaks on the first derivative of the titration plot corresponded to constituents of different basicities. Urea was selectively hydrolyzed at room temperature by the catalytic action of urease enzyme leaving HMTA unaffected. Ammonium hydroxide and ammonium bicarbonate produced from urea and HMTA were sequentially titrated for the analysis of the feed solution to obtain the three corresponding peaks respectively. Two separate titrations were required for the analysis of the effluent solution, which contained free ammonia also. One aliquot was first titrated directly without adding urease (for free ammonia and HMTA) and another aliquot was titrated after treatment with urease. The end points due to the ammonia used for washing and that from urea hydrolysis merged resulting in the appearance of three peaks again. Using this sequential method the relative standard deviations were found to be 0.81% and 1.38% for urea and HMTA, respectively, in eight determinations when the aliquots contained 50 to 75 mg of urea and 75 to 125 mg of HMTA. Feed and effluent solutions of the process stream were analyzed. (author)

  17. Sol-Gel Glasses

    Science.gov (United States)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  18. Entrapment of Probiotics in Water Extractable Arabinoxylan Gels: Rheological and Microstructural Characterization

    Directory of Open Access Journals (Sweden)

    Adriana Morales-Ortega

    2014-03-01

    Full Text Available Due to their porous structure, aqueous environment and dietary fiber nature arabinoxylan (AX gels could have potential applications for colon-specific therapeutic molecule delivery. In addition, prebiotic and health related effects of AX have been previously demonstrated. It has been also reported that cross-linked AX can be degraded by bacteria from the intestinal microbiota. However, AX gels have not been abundantly studied as carrier systems and there is no information available concerning their capability to entrap cells. In this regard, probiotic bacteria such as Bifidobacterium longum have been the focus of intense research activity lately. The objective of this research was to investigate the entrapment of probiotic B. longum in AX gels. AX solution at 2% (w/v containing B. longum (1 × 107 CFU/cm formed gels induced by laccase as cross-linking agent. The entrapment of B. longum decreased gel elasticity from 31 to 23 Pa, probably by affecting the physical interactions taking place between WEAX chains. Images of AX gels containing B. longum viewed under a scanning electron microscope show the gel network with the bacterial cells entrapped inside. The microstructure of these gels resembles that of an imperfect honeycomb. The results suggest that AX gels can be potential candidates for the entrapment of probiotics.

  19. Uranyl adsorption kinetics within silica gel: dependence on flow velocity and concentration

    Science.gov (United States)

    Dodd, Brandon M.; Tepper, Gary

    2017-09-01

    Trace quantities of a uranyl dissolved in water were measured using a simple optical method. A dilute solution of uranium nitrate dissolved in water was forced through nanoporous silica gel at fixed and controlled water flow rates. The uranyl ions deposited and accumulated within the silica gel and the uranyl fluorescence within the silica gel was monitored as a function of time using a light emitting diode as the excitation source and a photomultiplier tube detector. It was shown that the response time of the fluorescence output signal at a particular volumetric flow rate or average liquid velocity through the silica gel can be used to quantify the concentration of uranium in water. The response time as a function of concentration decreased with increasing flow velocity.

  20. A review of the influence of root-associating fungi and root exudates on the success of invasive plants

    Directory of Open Access Journals (Sweden)

    Cindy Bongard

    2012-08-01

    Full Text Available Plant-fungal interactions are essential for understanding the distribution and abundance of plants species. Recently, arbuscular mycorrhizal fungal (AMF partners of non-indigenous invasive plants have been hypothesized to be a critical factor influencing the invasion processes. AMF are known to improve nutrient and moisture uptake, as well as disrupt parasitic and pathogenic microbes in the host plant. Such benefits may enable invaders to establish significant and persistent populations in environments previously dominated by natives. Coupling these findings with studies on invader pathogen-disrupting root exudates is not well documented in the literature describing plant invasion strategies. The interaction effects of altered AMF associations and the impact of invader root exudates would be more relevant than understanding the AMF dynamics or the phytochemistry of successful invaders in isolation, particularly given that AMF and root exudates can have a similar role in pathogen control but function quite differently. One means to achieve this goal is to assess these strategies concurrently by characterizing both the general (mostly pathogens or commensals and AM-specific fungal colonization patterns found in field collected root samples of successful invaders, native plants growing within dense patches of invaders, and native plants growing separately from invaders. In this review I examine the emerging evidence of the ways in which AMF-plant interactions and the production of defensive root exudates provide pathways to invasive plant establishment and expansion, and conclude that interaction studies must be pursued to achieve a more comprehensive understanding of successful plant invasion.

  1. Quantification and enzyme targets of fatty acid amides from duckweed root exudates involved in the stimulation of denitrification.

    Science.gov (United States)

    Sun, Li; Lu, Yufang; Kronzucker, Herbert J; Shi, Weiming

    2016-07-01

    Fatty acid amides from plant root exudates, such as oleamide and erucamide, have the ability to participate in strong plant-microbe interactions, stimulating nitrogen metabolism in rhizospheric bacteria. However, mechanisms of secretion of such fatty acid amides, and the nature of their stimulatory activities on microbial metabolism, have not been examined. In the present study, collection, pre-treatment, and determination methods of oleamide and erucamide in duckweed root exudates are compared. The detection limits of oleamide and erucamide by gas chromatography (GC) (10.3ngmL(-1) and 16.1ngmL(-1), respectively) are shown to be much lower than those by liquid chromatography (LC) (1.7 and 5.0μgmL(-1), respectively). Quantitative GC analysis yielded five times larger amounts of oleamide and erucamide in root exudates of Spirodela polyrrhiza when using a continuous collection method (50.20±4.32 and 76.79±13.92μgkg(-1) FW day(-1)), compared to static collection (10.88±0.66 and 15.27±0.58μgkg(-1) FW day(-1)). Furthermore, fatty acid amide secretion was significantly enhanced under elevated nitrogen conditions (>300mgL(-1)), and was negatively correlated with the relative growth rate of duckweed. Mechanistic assays were conducted to show that erucamide stimulates nitrogen removal by enhancing denitrification, targeting two key denitrifying enzymes, nitrate and nitrite reductases, in bacteria. Our findings significantly contribute to our understanding of the regulation of nitrogen dynamics by plant root exudates in natural ecosystems. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Strippable gel for decontamination of contaminated metallic surfaces

    International Nuclear Information System (INIS)

    Banerjee, D.; Sandhya, U.; Khot, S.A.; Srinivas, C.; Wattal, P.K.

    2013-01-01

    Periodic decontamination of radioactive laboratories including fume hoods, glove boxes and all surfaces used for handling, processing and transporting radioactive materials is mandatory in all nuclear installations as this reduces spread of contamination and decreases total man rem exposure. Conventionally, chemical decontaminating agents or surfactant solutions are used for this purpose. However, this approach leads to generation of large volume of secondary radioactive waste. The use of strippable gel is an attractive alternative with low secondary waste generation particularly where removal of loose or weakly fixed contamination is necessary and also when the decontaminated material are to be reused, for e.g. decontamination of fume hoods, glove boxes, transport casks, spent fuel storage racks, control rod drive transport containers etc. Literature on gel formulations is scarce and mostly in the patent form. The sustained effort on gel formulation development has resulted in a basic gel formulation. The gel is a highly viscous water-based organic polymer, particularly suitable for application on vertical surfaces including difficult to reach metallic surfaces of complex geometry and not just limited to horizontal surfaces. The gel can be easily applied on contaminated surfaces by brushing or spraying. Curing of the gel is complete within 16-24 hours under ambient conditions and can then be removed by peeling as a dry sheet. While curing, the contaminants are trapped in gel either physically or chemically depending upon the nature of the contaminant. Salient features of cured gel include that it is water soluble and can be disposed off after immobilization in cement. Decontamination performance of the gel was initially evaluated by applying it on SS planchettes contaminated with known amount of radionuclides such as Cs(I), Co(II) and Ce(III). The measured decontamination factor was found to be in the range of 50-500, lowest for Ce(III) and highest for Co

  3. A new sol–gel synthesis of 45S5 bioactive glass using an organic acid as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Faure, J., E-mail: joel.faure@univ-reims.fr [Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2 (France); Drevet, R., E-mail: richard.drevet@univ-reims.fr [Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2 (France); Lemelle, A.; Ben Jaber, N.; Tara, A. [Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2 (France); El Btaouri, H. [Université de Reims Champagne-Ardenne UMR CNRS MEDyC, EA 7369, Campus Moulin de la Housse, 51687 REIMS Cedex 2 (France); Benhayoune, H. [Université de Reims Champagne-Ardenne, Laboratoire Ingénierie et Sciences des Matériaux, LISM EA 4695, 21 rue Clément ADER, 51685 REIMS Cedex 2 (France)

    2015-02-01

    In this paper a new sol–gel approach was explored for the synthesis of the 45S5 bioactive glass. We demonstrate that citric acid can be used instead of the usual nitric acid to catalyze the sol–gel reactions. The substitution of nitric acid by citric acid allows to reduce strongly the concentration of the acid solution necessary to catalyze the hydrolysis of silicon and phosphorus alkoxides. Two sol–gel powders with chemical compositions very close to that of the 45S5 were obtained by using either a 2 M nitric acid solution or either a 5 mM citric acid solution. These powders were characterized and compared to the commercial Bioglass®. The surface properties of the two bioglass powders were assessed by scanning electron microscopy (SEM) and by Brunauer–Emmett–Teller method (BET). The Fourier transformed infrared spectroscopy (FTIR) and the X-ray diffraction (XRD) revealed a partial crystallization associated to the formation of crystalline phases on the two sol–gel powders. The in vitro bioactivity was then studied at the key times during the first hours of immersion into acellular Simulated Body Fluid (SBF). After 4 h immersion into SBF we clearly demonstrate that the bioactivity level of the two sol–gel powders is similar and much higher than that of the commercial Bioglass®. This bioactivity improvement is associated to the increase of the porosity and the specific surface area of the powders synthesized by the sol–gel process. Moreover, the nitric acid is efficiently substituted by the citric acid to catalyze the sol–gel reactions without alteration of the bioactivity of the 45S5 bioactive glass. - Highlights: • Citric acid is employed as a catalyzer of the sol–gel process. • This catalyzer is used at a very low concentration for the hydrolysis reaction. • The chemical composition of the bioglass synthesized by the sol–gel process is optimized. • The properties of two sol–gel bioglasses are compared with those of the commercial

  4. A new sol–gel synthesis of 45S5 bioactive glass using an organic acid as catalyst

    International Nuclear Information System (INIS)

    Faure, J.; Drevet, R.; Lemelle, A.; Ben Jaber, N.; Tara, A.; El Btaouri, H.; Benhayoune, H.

    2015-01-01

    In this paper a new sol–gel approach was explored for the synthesis of the 45S5 bioactive glass. We demonstrate that citric acid can be used instead of the usual nitric acid to catalyze the sol–gel reactions. The substitution of nitric acid by citric acid allows to reduce strongly the concentration of the acid solution necessary to catalyze the hydrolysis of silicon and phosphorus alkoxides. Two sol–gel powders with chemical compositions very close to that of the 45S5 were obtained by using either a 2 M nitric acid solution or either a 5 mM citric acid solution. These powders were characterized and compared to the commercial Bioglass®. The surface properties of the two bioglass powders were assessed by scanning electron microscopy (SEM) and by Brunauer–Emmett–Teller method (BET). The Fourier transformed infrared spectroscopy (FTIR) and the X-ray diffraction (XRD) revealed a partial crystallization associated to the formation of crystalline phases on the two sol–gel powders. The in vitro bioactivity was then studied at the key times during the first hours of immersion into acellular Simulated Body Fluid (SBF). After 4 h immersion into SBF we clearly demonstrate that the bioactivity level of the two sol–gel powders is similar and much higher than that of the commercial Bioglass®. This bioactivity improvement is associated to the increase of the porosity and the specific surface area of the powders synthesized by the sol–gel process. Moreover, the nitric acid is efficiently substituted by the citric acid to catalyze the sol–gel reactions without alteration of the bioactivity of the 45S5 bioactive glass. - Highlights: • Citric acid is employed as a catalyzer of the sol–gel process. • This catalyzer is used at a very low concentration for the hydrolysis reaction. • The chemical composition of the bioglass synthesized by the sol–gel process is optimized. • The properties of two sol–gel bioglasses are compared with those of the commercial

  5. Photodegradation of indigo carmine and methylene blue dyes in aqueous solution by SiC-TiO{sub 2} catalysts prepared by sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Solis, Christian [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Juarez-Ramirez, Isaias, E-mail: isajua13@yahoo.com [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Moctezuma, Edgar [Facultad de Ciencias Quimicas, Universidad Autonoma de San Luis Potosi, San Luis Potosi Av. Manuel Nava 6, San Luis Potosi, S.L.P. 78290 (Mexico); Torres-Martinez, Leticia M. [Departamento de Ecomateriales y Energia, Facultad de Ingenieria Civil, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Photodegradation of organic dyes is possible using sol-gel SiC-TiO{sub 2} catalysts. Black-Right-Pointing-Pointer SiC-TiO{sub 2} makes a synergy effect that enhances its catalytic activity. Black-Right-Pointing-Pointer Sol-gel allows good dispersion and attachment of TiO{sub 2} particles on SiC surface. Black-Right-Pointing-Pointer SiC-TiO{sub 2} exhibits better activity than TiO{sub 2} (P25) on organic dyes degradation. Black-Right-Pointing-Pointer SiC-TiO{sub 2} catalysts are settled down and easily separated after photocatalysis. - Abstract: Indigo carmine and methylene blue dyes in aqueous solution were photodegraded using SiC-TiO{sub 2} catalysts prepared by sol-gel method. After thermal treatment at 450 Degree-Sign C, SiC-TiO{sub 2} catalysts prepared in this work showed the presence of SiC and TiO{sub 2} anatase phase. Those compounds showed specific surface area values around 22-25 m{sup 2} g{sup -1}, and energy band gap values close to 3.05 eV. In comparison with TiO{sub 2} (P25), SiC-TiO{sub 2} catalysts showed the highest activity for indigo carmine and methylene blue degradation, but this activity cannot be attributed to the properties above mentioned. Therefore, photocatalytic performance is due to the synergy effect between SiC and TiO{sub 2} particles caused by the sol-gel method used to prepare the SiC-TiO{sub 2} catalysts. TiO{sub 2} nanoparticles are well dispersed onto SiC surface allowing the transfer of electronic charges between SiC and TiO{sub 2} semiconductors, which avoid the fast recombination of the electron-hole pair during the photocatalytic process.

  6. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by the sol-gel process

    Science.gov (United States)

    Bansal, N. P.

    1992-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water: TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, X-ray diffraction, surface area and pore size distribution measurements.

  7. Sol-gel based mid-infrared evanescent wave sensors for detection of organophosphate pesticides in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Janotta, Markus; Karlowatz, Manfred; Vogt, Frank; Mizaikoff, Boris

    2003-10-31

    This work demonstrates the application of organically modified sol-gels as recognition layers combined with mid-infrared evanescent wave sensors for in situ detection of nitrated organics in aqueous media. Sol-gels were prepared by acid-catalyzed copolymerization of phenyltrimethoxysilane (PTMOS) and tetramethoxysilane (TMOS) and were spin-coated onto ZnSe attenuated total reflection (ATR) waveguides. These sensors were investigated with respect to their enrichment properties of selected organophosphates, i.e. parathion, fenitrothion and paraoxon, respectively, and their capability of suppressing interfering water background absorptions. Figures of merit are derived from calibration curves determined to assess sensitivity and reproducibility of the applied sensor system. It can be concluded that sol-gel coated infrared optical sensors enable reproducible detection of organophosphates down to the sub-ppm concentration range. Furthermore, measurement of spiked river water samples demonstrates feasibility as remote field sensor system. Once the required sensitivity is achieved, sol-gel based mid-infrared evanescent wave sensors have the potential of being an alternative to commonly applied biosensors for detection of organophosphates in environmental analysis, since they provide superior mechanical and chemical stability during application relevant periods of time.

  8. ZnCl{sub 2}- and NH{sub 4}Cl-hydroponics gel electrolytes for zinc-carbon batteries

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, N.H.; Ismail, Y.M. Baba; Mohamad, A.A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2008-01-21

    Absorbency testing is used to determine the percentage of ZnCl{sub 2} or NH{sub 4}Cl solution absorbed by a hydroponics gel (HPG). It is found that the absorbency of ZnCl{sub 2} or NH{sub 4}Cl solution decreases with increasing solution concentration. The conductivity of ZnCl{sub 2}- and NH{sub 4}Cl-HPG electrolytes is dependent on the solution concentration. A mixture of salt solution with HPG yields excellent gel polymer electrolytes with conductivities of 0.026 and 0.104 S cm{sup -1} at 3 M ZnCl{sub 2} and 7 M NH{sub 4}Cl, respectively. These gel electrolytes are then used to produce zinc-carbon cells. The fabricated cells give capacities of 8.8 and 10.0 mAh, have an internal resistance of 25.4 and 19.8 {omega}, a maximum power density of 12.7 and 12.2 mW cm{sup -2}, and a short-circuit current density of 29.1 and 33.9 mA cm{sup -2} for ZnCl{sub 2}- and NH{sub 4}Cl-HPG electrolytes, respectively. (author)

  9. Surface Decontamination Studies of Cs-137 and Sr-85 Using Polymer Gel

    International Nuclear Information System (INIS)

    Pham, L.; Nguyen, C.; Nguyen, L.

    2015-01-01

    Strippable polymer coating is one of the methods for effective surface decontamination to remove isotopes on the contaminated surface. This method is applying in nuclear facilities on the World. In this paper, we present the results obtained in our laboratory from product the polymer coating to apply to remove radioisotopes of "1"3"7Cs and "8"5Sr from surface of glass, stainless steel, mild steel, ceramic, PVC plastic. This polymer gel solution consist of water soluble polymer preferably polyvinyl alcohol (PVA), plasticizing agent (glycerine) and chelating agents, (citric acid) which can be sprayed or pasted on to contaminated surface. After some hours, these gel solutions was dried to form a strong thin film and it was easily peeled off from a contaminated surface with the radioactive isotopes and can be disposed off as radioactive solid waste. In this study infrared spectrophotometry technique was used to examine the interaction of the cesium and strontium ions with polyvinyl alcohol (PVA), polymer gel and the results of the study were also presented. The results showed that decontamination efficiency of "1"3"7Cs and "8"5Sr strongly depended on property, porosity and smoothness of the contaminated surface and obtained from 95-99% on glass and stainless steel, ceramic and PVC plastic surfaces. The decontamination efficiency also depended on activity and coating thickness. Optimization of film thickness is around 0.2 mm. Decontamination efficiency of Polymer gel were compared with Decongel 1101 (product from USA) on surfaces. IR spectra studies indicated that Cs and Sr ions interacted with PVA and citric acid in Polymer gel through cacboxyl (C = O) group. Polymer gel could remove of "1"3"7Cs and "8"5Sr better than PVA gel does because of citric acid, which can form chelating complex with Cs and Sr ion. (author)

  10. User`s guide and documentation manual for ``PC-Gel`` simulator

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ming-Ming; Gao, Hong W.

    1993-10-01

    PC-GEL is a three-dimensional, three-phase (oil, water, and gas) permeability modification simulator developed by incorporating an in-situ gelation model into a black oil simulator (BOAST) for personal computer application. The features included in the simulator are: transport of each chemical species of the polymer/crosslinker system in porous media, gelation reaction kinetics of the polymer with crosslinking agents, rheology of the polymer and gel, inaccessible pore volume to macromolecules, adsorption of chemical species on rock surfaces, retention of gel on the rock matrix, and permeability reduction caused by the adsorption of polymer and gel. The in-situ gelation model and simulator were validated against data reported in the literature. The simulator PC-GEL is useful for simulating and optimizing any combination of primary production, waterflooding, polymer flooding, and permeability modification treatments. A general background of permeability modification using crosslinked polymer gels is given in Section I and the governing equations, mechanisms, and numerical solutions of PC-GEL are given in Section II. Steps for preparing an input data file with reservoir and gel-chemical transport data, and recurrent data are described in Sections III and IV, respectively. Example data inputs are enclosed after explanations of each input line to help the user prepare data files. Major items of the output files are reviewed in Section V. Finally, three sample problems for running PC-GEL are described in Section VI, and input files and part of the output files of these problems are listed in the appendices. For the user`s reference a copy of the source code of PC-GEL computer program is attached in Appendix A.

  11. Optical coherence tomography-based decision making in exudative age-related macular degeneration: comparison of time- vs spectral-domain devices.

    Science.gov (United States)

    Cukras, C; Wang, Y D; Meyerle, C B; Forooghian, F; Chew, E Y; Wong, W T

    2010-05-01

    To determine whether optical coherence tomography (OCT) device-type influences clinical grading of OCT imaging in the context of exudative age-related macular degeneration (AMD). Ninety-six paired OCT scans from 49 patients with active exudative AMD were obtained on both the time-domain Stratus OCT system and the spectral-domain Cirrus OCT system at the same visit. Three independent graders judged each scan for the presence of intraretinal fluid (IRF) or subretinal fluid (SRF). The degree of grader consensus was evaluated and the ability of the systems to detect the presence of disease activity was analysed. Cirrus OCT generated a higher degree of inter-grader consensus than Stratus OCT with higher intraclass correlation coefficients for all parameters analysed. A pair-wise comparison of Cirrus OCT with Stratus OCT systems revealed that Cirrus-based gradings more frequently reported the presence of SRF and IRF and detected overall neovascular activity at a higher rate (P<0.05) compared with Stratus-based gradings. The choice of time-domain (Stratus) vs spectra-domain (Cirrus) OCT systems has a measurable impact on clinical decision making in exudative AMD. Spectral-domain OCT systems may be able to generate more consensus in clinical interpretation and, in particular cases, detect disease activity not detected by time-domain systems. Clinical trials using OCT-based clinical evaluations of exudative AMD may need to account for these inter-system differences in planning and analysis.

  12. Optical Coherence Tomography-Based Decision Making in Exudative Age-related Macular Degeneration: Comparison of Time- versus Spectral-Domain Devices

    Science.gov (United States)

    Cukras, Catherine; Wang, Yunqing D.; Meyerle, Catherine B.; Forooghian, Farzin; Chew, Emily Y.; Wong, Wai T.

    2010-01-01

    Purpose To determine if optical coherence tomography (OCT) device-type influences clinical grading of OCT imaging in the context of exudative age-related macular degeneration (AMD). Methods Ninety-six paired OCT scans from 49 patients with active exudative AMD were obtained on both the time-domain Stratus™ OCT system and the spectral-domain Cirrus™ OCT system at the same visit. Three independent graders judged each scan for the presence of intraretinal fluid (IRF) or subretinal fluid (SRF). The degree of grader consensus was evaluated and the ability of the systems to detect the presence of disease activity was analyzed. Results Cirrus™ OCT generated a higher degree of inter-grader consensus than Stratus OCT with higher intraclass correlation coefficients (ICC) for all parameters analyzed. A pair-wise comparison of Cirrus™ OCT to Stratus™ OCT systems revealed that Cirrus™-based gradings more frequently reported the presence of SRF and IRF and detected overall neovascular activity at a higher rate (p<0.05) compared to Stratus™-based gradings Conclusions The choice of time-domain (Stratus™) versus spectra-domain (Cirrus™) OCT systems has a measurable impact on clinical decision making in exudative AMD. Spectral-domain OCT systems may be able to generate more consensus in clinical interpretation and, in particular cases, detect disease activity not detected by time-domain systems. Clinical trials employing OCT-based clinical evaluations of exudative AMD may need to account for these inter-system differences in planning and analysis. PMID:19696804

  13. Tetragonal-cubic phase boundary in nanocrystalline ZrO{sub 2}-Y{sub 2}O{sub 3} solid solutions synthesized by gel-combustion

    Energy Technology Data Exchange (ETDEWEB)

    Fabregas, Ismael O. [CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Craievich, Aldo F.; Fantini, Marcia C.A. [Instituto de Fisica, Universidade de Sao Paulo, Travessa R da Rua do Matao, No. 187, Cidade Universitaria, 05508-900 Sao Paulo (Brazil); Millen, Ricardo P.; Temperini, Marcia L.A. [Instituto de Quimica, Universidade de Sao Paulo, Avenida Prof. Lineu Prestes 748, Cidade Universitaria, 05508-900 Sao Paulo (Brazil); Lamas, Diego G., E-mail: dlamas@uncoma.edu.ar [CINSO (Centro de Investigaciones en Solidos), CITEFA-CONICET, J.B. de La Salle 4397, 1603 Villa Martelli, Pcia. de Buenos Aires (Argentina); Laboratorio de Caracterizacion de Materiales, Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires 1400, (8300) Neuquen Capital, Prov. de Neuquen (Argentina)

    2011-04-21

    Research highlights: > Gel-combustion synthesis yields compositionally homogeneous, single-phased ZrO{sub 2}-Y{sub 2}O{sub 3} nanopowders, that exhibit the presence at room temperature of three different phases depending on Y{sub 2}O{sub 3} content, namely two tetragonal forms (t' and t'') and the cubic phase. > Phase identification can be achieved by synchrotron XPD (SXPD) and Raman spectroscopy since the tetragonal forms and the cubic phase can be distinguished by these techniques. > The crystallographic features of ZrO{sub 2}-Y{sub 2}O{sub 3} nanopowders were determined by SXPD. They are similar to those reported by Yashima and coworkers for compositionally homogeneous materials containing larger (micro)crystals. However, the lattice parameters are slightly different and the axial ratios c/a of our t' samples are smaller than those reported by these authors. > Compositional t'/t'' and t''/cubic phase boundaries are located at (9 {+-} 1) and (10.5 {+-} 0.5) mol% Y{sub 2}O{sub 3}, respectively. > For the whole series of nanocrystalline ZrO{sub 2}-Y{sub 2}O{sub 3} solid solutions studied in the present work, no evidences of the presence of a mixture of phases - as reported by Yashima and coworkers for microcrystalline solid solutions - were detected. - Abstract: By means of synchrotron X-ray powder diffraction (SXPD) and Raman spectroscopy, we have detected, in a series of nanocrystalline and compositionally homogeneous ZrO{sub 2}-Y{sub 2}O{sub 3} solid solutions, the presence at room temperature of three different phases depending on Y{sub 2}O{sub 3} content, namely two tetragonal forms and the cubic phase. The studied materials, with average crystallite sizes within the range 7-10 nm, were synthesized by a nitrate-citrate gel-combustion process. The crystal structure of these phases was also investigated by SXPD. The results presented here indicate that the studied nanocrystalline ZrO{sub 2}-Y{sub 2}O{sub 3} solid

  14. Combined sol–gel and carbothermal synthesis of ZrC–TiC powders for composites

    Energy Technology Data Exchange (ETDEWEB)

    Umalas, Madis [Institute of Physics, University of Tartu, Riia 142, 51014, Tartu (Estonia); Estonian Nanotechnology Competence Centre, Riia 142, 51014, Tartu (Estonia); Hussainova, Irina, E-mail: irina.hussainova@ttu.ee [Department of Materials Engineering, Tallinn University of Technology, Ehitajate 5, 19086, Tallinn (Estonia); ITMO University, Kronverksky 49, St. Petersburg, 197101 (Russian Federation); Reedo, Valter [Institute of Physics, University of Tartu, Riia 142, 51014, Tartu (Estonia); Young, Der-Liang [Department of Materials Engineering, Tallinn University of Technology, Ehitajate 5, 19086, Tallinn (Estonia); Cura, Erkin; Hannula, Simo-Pekka [Department of Materials Science and Engineering, Aalto University, School of Chemical Technology, POB 16200, Aalto, 00076 (Finland); Lõhmus, Rünno [Institute of Physics, University of Tartu, Riia 142, 51014, Tartu (Estonia); Estonian Nanotechnology Competence Centre, Riia 142, 51014, Tartu (Estonia); Lõhmus, Ants [Institute of Physics, University of Tartu, Riia 142, 51014, Tartu (Estonia)

    2015-03-01

    The TiC–ZrC binary compound of nanostructured powders was synthesised by combination of sol–gel and carbothermal reduction. The polymeric precursor of the blend was produced by sol–gel process from titanium tetrabutoxide, zirconium tetrabutoxide and benzene-1.4-diol; then carbothermally reduced to the TiC–ZrC blend at 1600 °C in an inert environment. The chemical reactions occurring in the system were monitored by infrared spectrometry. Stable alkoxide solution was obtained by adding acetylacetone to avoid premature gelation of the metal alkoxide mixture. A solid solution of ZrTiC{sub 2} was produced by spark plasma sintering at temperature of 2000 °C. - Highlights: • A polymeric precursor of TiC–ZrC blend was synthesised by sol–gel process. • The polymeric precursor synthesis was studied by infrared spectroscopy. • TiC–ZrC powder blend was carbothermally reduced from polymeric precursor. • TiC–ZrC powder blend was sintered to ZrTiC{sub 2} solid solution by spark plasma sintering. • Sintered ZrTiC{sub 2} have good mechanical properties.

  15. Combined sol–gel and carbothermal synthesis of ZrC–TiC powders for composites

    International Nuclear Information System (INIS)

    Umalas, Madis; Hussainova, Irina; Reedo, Valter; Young, Der-Liang; Cura, Erkin; Hannula, Simo-Pekka; Lõhmus, Rünno; Lõhmus, Ants

    2015-01-01

    The TiC–ZrC binary compound of nanostructured powders was synthesised by combination of sol–gel and carbothermal reduction. The polymeric precursor of the blend was produced by sol–gel process from titanium tetrabutoxide, zirconium tetrabutoxide and benzene-1.4-diol; then carbothermally reduced to the TiC–ZrC blend at 1600 °C in an inert environment. The chemical reactions occurring in the system were monitored by infrared spectrometry. Stable alkoxide solution was obtained by adding acetylacetone to avoid premature gelation of the metal alkoxide mixture. A solid solution of ZrTiC 2 was produced by spark plasma sintering at temperature of 2000 °C. - Highlights: • A polymeric precursor of TiC–ZrC blend was synthesised by sol–gel process. • The polymeric precursor synthesis was studied by infrared spectroscopy. • TiC–ZrC powder blend was carbothermally reduced from polymeric precursor. • TiC–ZrC powder blend was sintered to ZrTiC 2 solid solution by spark plasma sintering. • Sintered ZrTiC 2 have good mechanical properties

  16. Sol-gel synthesis of YBa2Cu3O7-x superconductor by mixed organic-inorganic polymerization

    International Nuclear Information System (INIS)

    Valente, I.; Sanchez, C.; Henry, M.; Livage, J.

    1989-01-01

    Sol-gel processes are quite attractive methods to produce films or fibers of high Tc superconducting materials. The gel step allows a good chemical homogeneity and generally provides a rather low processing temperature. Blue sols or monolithic gels can be easily produced using mixed organic-inorganic polymerisation of molecular precursors. An aqueous solution of copper, barium acetates and yttrium nitrate is mixed with an acrylic acid solution where a radical organic polymerisation process has been initiated. After pH adjustments, the viscosity of the resulting solution can be adjusted by heating. After drying at 150 0 C and calcination above 700 0 C, the YBaCuO network is formed and superconducting properties appears above 850 0 C. Fine particles (0.1-1 μm) are obtained which can be sintered to produce a ceramic material with a particularly narrow resistive transition [fr

  17. Use of resonance ionization spectroscopy to detect DNA bands on ultrathin spin-coated gels.

    Science.gov (United States)

    Doktycz, M J; Gibson, W A; Arlinghaus, H F; Allen, R C; Jacobson, K B

    1993-01-01

    Development of alternative electrophoresis procedures are necessary for large volume sequencing and mapping studies. The use of stable isotopes as DNA labels and ultrathin gels promises to greatly increase the rate of sequencing. Spin coating is presented as an alternative method for producing ultrathin polyacrylamide gels. The technique has the potential of producing gels of micron to submicron thicknesses by varying the viscosity of the acrylamide solution and the spinning speed. Thirty micron thick 6% (weight %) gels were produced in this manner. Tin-labeled DNA oligomers were electrophoresed and detected using sputter-initiated resonance ionization spectroscopy (SIRIS). The usefulness of SIRIS and laser atomization RIS (LARIS) to sample the surface and deeper layers of 240 microns thick gels was investigated. With LARIS, whole cross-sections of the gel can be atomized, possibly allowing complete sampling of labels.

  18. Agarose gel electrophoresis for the separation of DNA fragments.

    Science.gov (United States)

    Lee, Pei Yun; Costumbrado, John; Hsu, Chih-Yuan; Kim, Yong Hoon

    2012-04-20

    Agarose gel electrophoresis is the most effective way of separating DNA fragments of varying sizes ranging from 100 bp to 25 kb(1). Agarose is isolated from the seaweed genera Gelidium and Gracilaria, and consists of repeated agarobiose (L- and D-galactose) subunits(2). During gelation, agarose polymers associate non-covalently and form a network of bundles whose pore sizes determine a gel's molecular sieving properties. The use of agarose gel electrophoresis revolutionized the separation of DNA. Prior to the adoption of agarose gels, DNA was primarily separated using sucrose density gradient centrifugation, which only provided an approximation of size. To separate DNA using agarose gel electrophoresis, the DNA is loaded into pre-cast wells in the gel and a current applied. The phosphate backbone of the DNA (and RNA) molecule is negatively charged, therefore when placed in an electric field, DNA fragments will migrate to the positively charged anode. Because DNA has a uniform mass/charge ratio, DNA molecules are separated by size within an agarose gel in a pattern such that the distance traveled is inversely proportional to the log of its molecular weight(3). The leading model for DNA movement through an agarose gel is "biased reptation", whereby the leading edge moves forward and pulls the rest of the molecule along(4). The rate of migration of a DNA molecule through a gel is determined by the following: 1) size of DNA molecule; 2) agarose concentration; 3) DNA conformation(5); 4) voltage applied, 5) presence of ethidium bromide, 6) type of agarose and 7) electrophoresis buffer. After separation, the DNA molecules can be visualized under uv light after staining with an appropriate dye. By following this protocol, students should be able to: Understand the mechanism by which DNA fragments are separated within a gel matrix Understand how conformation of the DNA molecule will determine its mobility through a gel matrix Identify an agarose solution of appropriate

  19. Silica-gel structural characterization during the initial phases of gelation and drying

    International Nuclear Information System (INIS)

    Ferreira, Max Passos

    1996-01-01

    For centuries, glasses and ceramics have been made via melting or solid state reactions at temperatures above 100 deg C. The sol-gel process offers new approaches to the synthesis of glasses and ceramics, combining control of composition and structure at the molecular level with the ability to shape materials in bulk, powder, fiber and thin-film forms. The growth of sol-gel technology research is due to the many unique features of that class of materials. Major applications include optical elements and integrated optical devices, ceramic filters, membranes, supercondutors, magnetic, catalytic and manostructured materials to antioxidant, anticorrosion coatings and composite and biomedical materials. In this work a variety of techniques like spectroscopy, Raman spectroscopy, ultraviolet-visible spectroscopy, light scattering nuclear magnetic resonance, X ray diffraction and nitrogen adsorption have been employed to investigate the initial phase of the sol-gel transition of gamma ray irradiated tetramethoxysilane (TMOS) solutions and non-irradiated TMOS solution and to get information about the structure of the silica gels obtained under different gelation conditions. Typically the tetramethoxysilane solutions were prepared using a molar ratio of TMOS to demineralized water of 1 to 16. Some experiments were made under catalysed conditions. The mixing was carried out at room temperature. The turbidity and light scattering experiments on the polycondensation of tetramethoxysilane show that exists no drastic difference in the gelling time of a gamma ray irradiated and a non-irradiated TMOS+H 2 O (1+16 M) solution. In the absence of a catalyst, the gelling time for both reactions occurs in about 3.30 h. When HNO 3 (o.03 M) was used, the gelling time observed was 3 days. Raman and ultraviolet-visible spectroscopy show no drastic difference during the initial phase at the sol-gel transition under ambient temperature/pressure and under gamma radiation. The gels heated

  20. Intracranial drug-delivery scaffolds: Biocompatibility evaluation of sucrose acetate isobutyrate gels

    International Nuclear Information System (INIS)

    Lee, James; Jallo, George I.; Penno, Margaret B.; Gabrielson, Kathleen L.; Young, G. David; Johnson, Randolph M.; Gillis, Edward M.; Rampersaud, Charles; Carson, Benjamin S.; Guarnieri, Michael

    2006-01-01

    Introduction: Sucrose acetate isobutyrate (SAIB) is a water insoluble, biodegradable gel used for controlled-release oral and subcutaneous drug delivery. We investigated SAIB compatibility in the rat central nervous system (CNS) by implanting solutions of SAIB in adult and in neonatal brains. Methods: 10-15 μL solutions of SAIB gels in 0-30% ethanol were injected into the cerebral cortex of adult Fischer 344 rats. Control animals were implanted with a 10 mg biodegradable poly anhydride copolymer of poly [bis (p-carboxyphenoxy) propane] anhydride and sebacic acid (PCPP:SA). Adult rats were evaluated for signs of pain and distress, including changes in posture, facial signs, and grooming behavior. 1-2 μL solutions of SAIB gels in 15% ethanol were injected into brains of 12-24 h-old rats. Neonatal rats were evaluated for survival. Adult and neonatal brains were examined by histopathology 3-48 days after implant. Results: Gel implants produced elliptical compression of cortical tissue, cell loss, and inflammation. Cell loss appeared to be confined to the implantation wound and associated neuronal fields. In adult rats, neurophil compression, inflammation, and cell loss appeared similar with the 10-mg PCPP:SA implants and the 10-mg SAIB implants. There was no clinical evidence of pain or distress from SAIB implants. 1-2 μL implants of SAIB-15% ethanol had no effect on survival of neonatal animals. Conclusion: Brain implants of SAIB induce a mild to moderate inflammatory response and associated neuronal cell damage. The implants appeared to be biocompatible in adult and neonatal animals. These results suggest that further studies of SAIB as an injectable drug-delivery scaffold for CNS therapeutic agents are warranted

  1. Solvent cleanup using base-treated silica gel solid adsorbent

    International Nuclear Information System (INIS)

    Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

    1984-06-01

    A solvent cleanup method using silica gel columns treated with either sodium hydroxide (NaOH) or lithium hydroxide (LiOH) has been investigated. Its effectiveness compares favorably with that of traditional wash methods. After treatment with NaOH solution, the gels adsorb HNO 3 , dibutyl phosphate (DBP), UO 2 2+ , Pu 4+ , various metal-ion fission products, and other species from the solvent. Adsorption mechanisms include neutralization, hydrolysis, polymerization, and precipitation, depending on the species adsorbed. Sodium dibutyl phosphate, which partially distributes to the solvent from the gels, can be stripped with water; the stripping coefficient ranges from 280 to 540. Adsorption rates are diffusion controlled such that temperature effects are relatively small. Recycle of the gels is achieved either by an aqueous elution and recycle sequence or by a thermal treatment method, which may be preferable. Potential advantages of this solvent cleanup method are that (1) some operational problems are avoided and (2) the amount of NaNO 3 waste generated per metric ton of nuclear fuel reprocessed would be reduced significantly. 19 references, 6 figures, 12 tables

  2. The influence of Aloe vera gel incorporation on the physicochemical and mechanical properties of banana starch-chitosan edible films.

    Science.gov (United States)

    Pinzon, Magda I; Garcia, Omar R; Villa, Cristian C

    2018-01-27

    Aloe vera (AV) gel is a promising material in food conservation, given its widely reported antimicrobial and antioxidant activity; however, its application in the formation of edible films and coatings has been small owing its low film-forming capability. The aim of this study was to investigate the physicochemical properties of film-forming solutions and films prepared using unripe banana starch-chitosan and AV gel at different AV gel concentrations. Our results showed that AV gel considerably affected the rheological and optical properties of the edible coatings, mainly due to increased amounts of solids brought by the AV gel. Film-forming capacity and physicochemical properties were also studied; most of the film properties were affected by the inclusion of AV gel, with decreased water vapor permeability, tensile strength and elongation at break. Fourier transform infrared studies showed that the inclusion of AV gel disrupts the interaction between starch and chitosan molecules; however, further studies are needed to fully understand the specific interactions between the components of AV gel and both starch and chitosan molecules. Our results suggest that the addition of AV gel creates a crosslinking effect between the phenolic compounds in AV gel and starch molecules, which disrupts the starch-chitosan interaction and greatly affects the properties of both the film-forming solution and edible films. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  3. Neurogenic plasma exudation mediates grain dust-induced tissue injury in vivo.

    Science.gov (United States)

    Gao, X P; Von Essen, S; Rubinstein, I

    1997-02-01

    The purpose of this study was to determine whether an aqueous extract of grain sorghum dust (GDE) elicits neurogenic plasma exudation in the oral mucosa in vivo. Using intravital microscopy, we found that GDE elicited significant, concentration-dependent leaky site formation and an increase in clearance of fluorescein isothiocyanate-labeled dextran (FITC-dextran; mol mass 70 kDa) from the hamster cheek pouch (P grain sorghum dust elicits immediate oral mucosa inflammation in vivo.

  4. Preoperative povidone-iodine vaginal gel in abdominal hysterectomy: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Beigi A

    2007-09-01

    Full Text Available Background: Infectious complications of hysterectomy remain common despite the use of antibiotic. The usual existing methods of preoperative antisepsis do not control the vaginal bacteria that are the primary cause of contamination at the surgical site. Our goal was to assess whether febrile morbidity after total abdominal hysterectomy is decreased by the addition of povidone-iodine gel at the vaginal apex after the routine vaginal preparation with povidone-iodine solution.Methods: We carried out a prospective randomized trial on women admitted for elective abdominal hysterectomy. Inclusion criteria included planned abdominal hysterectomy for benign or malignant gynecologic conditions. Exclusion criteria consisted of emergency surgery, current treatment for pelvic infection, and known povidone-iodine allergy. A total of 168 patients were randomized to either the control group or the intervention group, who received 20 cc povidone-iodine gel placed at the vaginal apex immediately before the operation. Both groups received the routine preoperative preparation of antimicrobial prophylaxis, abdominal and vaginal scrubbing with povidone-iodine solution prior to the operation. The primary outcome was post-operative febrile morbidity. Other outcomes included abdominal wound infection, vaginal cuff cellulitis or pelvic abscess. Data was analyzed using Fisher's exact test. p<0.05 was considered statistically significant.Results: The overall rate of febrile morbidity was 20.5%. Febrile morbidity occurred in ten of 80 (12.5% women receiving the povidone-iodine gel preparation and 24 of 86 (27.9% women not receiving the gel (p<0.05. The rate of abdominal wound infection was 18.6% (16 in the control group, and 5% (4 in the gel group (p<0.05. Vaginal cuff cellulitis was seen in three patients from the control group versus one woman from the gel group (p>0.05. Pelvic abscess was diagnosed in one patient from the control group and in no patients from the

  5. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, Wenfeng; Piras, Daniele; Heijblom, Michelle; Steenbergen, Wiendelt; van Leeuwen, Ton G.; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  6. Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited

    NARCIS (Netherlands)

    Xia, W.; Piras, D.; Heijblom, M.; Steenbergen, Wiendelt; van Leeuwen, Ton; Manohar, Srirang

    2011-01-01

    A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F–T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where

  7. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Directory of Open Access Journals (Sweden)

    Margaret Salmon

    Full Text Available This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  8. Alternative Ultrasound Gel for a Sustainable Ultrasound Program: Application of Human Centered Design.

    Science.gov (United States)

    Salmon, Margaret; Salmon, Christian; Bissinger, Alexa; Muller, Mundenga Mutendi; Gebreyesus, Alegnta; Geremew, Haimanot; Wendel, Sarah K; Wendell, Sarah; Azaza, Aklilu; Salumu, Maurice; Benfield, Nerys

    2015-01-01

    This paper describes design of a low cost, ultrasound gel from local products applying aspects of Human Centered Design methodology. A multidisciplinary team worked with clinicians who use ultrasound where commercial gel is cost prohibitive and scarce. The team followed the format outlined in the Ideo Took Kit. Research began by defining the challenge "how to create locally available alternative ultrasound gel for a low-resourced environment? The "End-Users," were identified as clinicians who use ultrasound in Democratic Republic of the Congo and Ethiopia. An expert group was identified and queried for possible alternatives to commercial gel. Responses included shampoo, oils, water and cornstarch. Cornstarch, while a reasonable solution, was either not available or too expensive. We then sought deeper knowledge of locally sources materials from local experts, market vendors, to develop a similar product. Suggested solutions gleaned from these interviews were collected and used to create ultrasound gel accounting for cost, image quality, manufacturing capability. Initial prototypes used cassava root flour from Great Lakes Region (DRC, Rwanda, Uganda, Tanzania) and West Africa, and bula from Ethiopia. Prototypes were tested in the field and resulting images evaluated by our user group. A final prototype was then selected. Cassava and bula at a 32 part water, 8 part flour and 4 part salt, heated, mixed then cooled was the product design of choice.

  9. Modeling of Nonlinear Dynamics and Synchronized Oscillations of Microbial Populations, Carbon and Oxygen Concentrations, Induced by Root Exudation in the Rhizosphere

    Science.gov (United States)

    Molz, F. J.; Faybishenko, B.; Jenkins, E. W.

    2012-12-01

    Mass and energy fluxes within the soil-plant-atmosphere continuum are highly coupled and inherently nonlinear. The main focus of this presentation is to demonstrate the results of numerical modeling of a system of 4 coupled, nonlinear ordinary differential equations (ODEs), which are used to describe the long-term, rhizosphere processes of soil microbial dynamics, including the competition between nitrogen-fixing bacteria and those unable to fix nitrogen, along with substrate concentration (nutrient supply) and oxygen concentration. Modeling results demonstrate the synchronized patterns of temporal oscillations of competing microbial populations, which are affected by carbon and oxygen concentrations. The temporal dynamics and amplitude of the root exudation process serve as a driving force for microbial and geochemical phenomena, and lead to the development of the Gompetzian dynamics, synchronized oscillations, and phase-space attractors of microbial populations and carbon and oxygen concentrations. The nonlinear dynamic analysis of time series concentrations from the solution of the ODEs was used to identify several types of phase-space attractors, which appear to be dependent on the parameters of the exudation function and Monod kinetic parameters. This phase space analysis was conducted by means of assessing the global and local embedding dimensions, correlation time, capacity and correlation dimensions, and Lyapunov exponents of the calculated model variables defining the phase space. Such results can be used for planning experimental and theoretical studies of biogeochemical processes in the fields of plant nutrition, phyto- and bio-remediation, and other ecological areas.

  10. Genetic Determinism of Sensitivity to Corynespora cassiicola Exudates in Rubber Tree (Hevea brasiliensis).

    Science.gov (United States)

    Tran, Dinh Minh; Clément-Demange, André; Déon, Marine; Garcia, Dominique; Le Guen, Vincent; Clément-Vidal, Anne; Soumahoro, Mouman; Masson, Aurélien; Label, Philippe; Le, Mau Tuy; Pujade-Renaud, Valérie

    2016-01-01

    An indirect phenotyping method was developed in order to estimate the susceptibility of rubber tree clonal varieties to Corynespora Leaf Fall (CLF) disease caused by the ascomycete Corynespora cassiicola. This method consists in quantifying the impact of fungal exudates on detached leaves by measuring the induced electrolyte leakage (EL%). The tested exudates were either crude culture filtrates from diverse C. cassiicola isolates or the purified cassiicolin (Cas1), a small secreted effector protein produced by the aggressive isolate CCP. The test was found to be quantitative, with the EL% response proportional to toxin concentration. For eight clones tested with two aggressive isolates, the EL% response to the filtrates positively correlated to the response induced by conidial inoculation. The toxicity test applied to 18 clones using 13 toxinic treatments evidenced an important variability among clones and treatments, with a significant additional clone x treatment interaction effect. A genetic linkage map was built using 306 microsatellite markers, from the F1 population of the PB260 x RRIM600 family. Phenotyping of the population for sensitivity to the purified Cas1 effector and to culture filtrates from seven C. cassiicola isolates revealed a polygenic determinism, with six QTL detected on five chromosomes and percentages of explained phenotypic variance varying from 11 to 17%. Two common QTL were identified for the CCP filtrate and the purified cassiicolin, suggesting that Cas1 may be the main effector of CCP filtrate toxicity. The CCP filtrate clearly contrasted with all other filtrates. The toxicity test based on Electrolyte Leakage Measurement offers the opportunity to assess the sensitivity of rubber genotypes to C. cassiicola exudates or purified effectors for genetic investigations and early selection, without risk of spreading the fungus in plantations. However, the power of this test for predicting field susceptibility of rubber clones to CLF will have

  11. Diagnostic yield and safety of closed needle pleural biopsy in exudative pleural effusion.

    Science.gov (United States)

    Rajawat, Govind Singh; Batra, Supreet; Takhar, Rajendra Prasad; Rathi, Lalit; Bhandari, Chand; Gupta, Manohar Lal

    2017-01-01

    Closed pleural biopsy was previously considered a procedure of choice in cases of undiagnosed pleural effusion with good efficacy. Currently, the closed pleural biopsy has been replaced by thoracoscopic biopsy but not easily available in resource-limited setups. The objective of this study was to analyze the diagnostic yield and safety of closed needle pleural biopsy in exudative pleural effusion and assessment of patients' characteristics with the yield of pleural biopsy. This was a cross-sectional study. This study was conducted at Institute of Respiratory Diseases, SMS Medical College, Jaipur, a tertiary care center of West India. A total of 250 cases of pleural effusion were evaluated with complete pleural fluid biochemical, microbiological, and cytological examination. Out of these 250 patients, 59 were excluded from the study as the diagnosis could be established on initial pleural fluid examination. The remaining (191) patients were considered for closed pleural biopsy with Abrams pleural biopsy needle. The main outcome measure was diagnostic yield in the form of confirming diagnosis. Out of the 191 patients with exudative lymphocytic pleural effusion, 123 (64.40%) were diagnosed on the first pleural biopsy. Among the remaining 68 patients, 22 patients had repeat pleural biopsy with a diagnostic yield of 59.9%. The overall pleural biopsy could establish the diagnosis in 136 (71.20%) patients with pleural effusion. The most common diagnosis on pleural biopsy was malignancy followed by tuberculosis. Closed pleural biopsy provides diagnostic yield nearly comparative to thoracoscopy in properly selected patients of pleural effusions. In view of good yield, low cost, easy availability, and very low complication rate, it should be used routinely in all cases of undiagnosed exudative lymphocytic pleural effusion. There was no comparison with a similar group undergoing thoracoscopic pleural biopsy.

  12. GelTouch

    DEFF Research Database (Denmark)

    Miruchna, Viktor; Walter, Robert; Lindlbauer, David

    2015-01-01

    We present GelTouch, a gel-based layer that can selectively transition between soft and stiff to provide tactile multi-touch feedback. It is flexible, transparent when not activated, and contains no mechanical, electromagnetic, or hydraulic components, resulting in a compact form factor (a 2mm thin...... touchscreen layer for our prototype). The activated areas can be morphed freely and continuously, without being limited to fixed, predefined shapes. GelTouch consists of a poly(N-isopropylacrylamide) gel layer which alters its viscoelasticity when activated by applying heat (>32 C). We present three different...

  13. Organic anion exudation by ectomycorrhizal fungi and Pinus sylvestris in response to nutrient deficiences

    NARCIS (Netherlands)

    Schöll, van L.; Hoffland, E.; Breemen, van N.

    2006-01-01

    Low molecular weight organic anions (LMWOA) can enhance weathering of mineral grains. We tested the hypothesis that ectomycorrhizal (EcM) fungi and tree seedlings increase their exudation of LMWOA when supply of magnesium, potassium and phosphorus is low to enhance the mobilization of Mg, K and P

  14. MACULAR CHOROIDAL VOLUME CHANGES AFTER INTRAVITREAL BEVACIZUMAB FOR EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

    Science.gov (United States)

    Palkovits, Stefan; Seidel, Gerald; Pertl, Laura; Malle, Eva M; Hausberger, Silke; Makk, Johanna; Singer, Christoph; Osterholt, Julia; Herzog, Sereina A; Haas, Anton; Weger, Martin

    2017-12-01

    To evaluate the effect of intravitreal bevacizumab on the macular choroidal volume and the subfoveal choroidal thickness in treatment naïve eyes with exudative age-related macular degeneration. The macular choroidal volume and the subfoveal choroidal thickness were measured using enhanced depth imaging optical coherence tomography. After a screening examination, each patient received 3 monthly intravitreal injections of 1.25 mg bevacizumab. One month after the third injection was a final assessment. Forty-seven patients with a mean age of 80 ± 6.4 years were included. The macular choroidal volume decreased significantly from median 4.1 mm (interquartile range 3.4-5.9) to median 3.9 mm (interquartile range 3.1-5.6) between the baseline and final examination (difference -0.46 mm, 95% confidence interval: -0.57 to 0.35, P macular choroidal volume at baseline and subfoveal choroidal thickness at baseline were not associated with the response to treatment. The macular choroidal volume and the subfoveal choroidal thickness decreased significantly after 3 monthly bevacizumab injections for exudative age-related macular degeneration.

  15. Tumor Necrosis Factor-Alpha in Peripical Tissue Exudates of Teeth with Apical Periodontitis

    Directory of Open Access Journals (Sweden)

    Sonja Pezelj-Ribaric

    2007-01-01

    Full Text Available Aim. The aim of this study was to determine tumor necrosis factor-alpha (TNF-α levels in periapical exudates and to evaluate their relationship with radiological findings. Methodology. Periapical exudates were collected from root canals of 60 single-rooted teeth using absorbent paper points. TNF-α levels were determined by enzyme-linked immunosorbent assays. The samples were divided into three groups according to the periapical radiolucent area. Results. Nonparametric Kruskal-Wallis test revealed significant differences between TNF-α concentrations in control group (40, 57±28, 15 pg/mL and group with larger radiolucent areas (2365, 79±582, 95 pg/mL, as well as between control and canals with small radiolucent areas (507, 66±278, 97 (P<.05. Conclusions. The levels of TNF-α increase significantly in teeth with periapical pathosis, from smaller to bigger lesions. This research and its results have shown that objective analysis of the TNF-α levels enables establishment of a relationship between different concentrations of TNF-α and different radiological changes.

  16. New resin gel for uranium determination by diffusive gradient in thin films technique

    International Nuclear Information System (INIS)

    Gregusova, Michaela; Docekal, Bohumil

    2011-01-01

    A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10 2 mg L -1 . The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

  17. New resin gel for uranium determination by diffusive gradient in thin films technique

    Energy Technology Data Exchange (ETDEWEB)

    Gregusova, Michaela, E-mail: gregusova@iach.cz [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic); Docekal, Bohumil [Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic v.v.i., Veveri 97, 602 00 Brno (Czech Republic)

    2011-01-17

    A new resin gel based on Spheron-Oxin chelating ion-exchanger with anchored 8-hydroxyquinoline functional groups was tested for application in diffusive gradient in thin film technique (DGT) for determination of uranium. Selectivity of uranium uptake from model carbonate loaded solutions of natural water was studied under laboratory conditions and compared with selectivity of the conventional Chelex 100 based resin gel. The affinity of Spheron-Oxin functional groups enables determination of the overall uranium concentration in water containing carbonates up to the concentration level of 10{sup 2} mg L{sup -1}. The effect of uranium binding to the polyacrylamide (APA) and agarose diffusive gels (AGE) was also studied. Uranium is probably bound in both gels by a weak interaction with traces of acrylic acid groups in the structure of APA gel and with pyruvic and sulfonic acid groups in the AGE gel. These sorption effects can be eliminated to the negligible level by prolonged deployment of DGT probes or by disassembling probes after the 1-2 days post-sampling period that is sufficient for release of uranium from diffusive gel and its sorption in resin gel.

  18. The gel electrophoresis markup language (GelML) from the Proteomics Standards Initiative.

    Science.gov (United States)

    Gibson, Frank; Hoogland, Christine; Martinez-Bartolomé, Salvador; Medina-Aunon, J Alberto; Albar, Juan Pablo; Babnigg, Gyorgy; Wipat, Anil; Hermjakob, Henning; Almeida, Jonas S; Stanislaus, Romesh; Paton, Norman W; Jones, Andrew R

    2010-09-01

    The Human Proteome Organisation's Proteomics Standards Initiative has developed the GelML (gel electrophoresis markup language) data exchange format for representing gel electrophoresis experiments performed in proteomics investigations. The format closely follows the reporting guidelines for gel electrophoresis, which are part of the Minimum Information About a Proteomics Experiment (MIAPE) set of modules. GelML supports the capture of metadata (such as experimental protocols) and data (such as gel images) resulting from gel electrophoresis so that laboratories can be compliant with the MIAPE Gel Electrophoresis guidelines, while allowing such data sets to be exchanged or downloaded from public repositories. The format is sufficiently flexible to capture data from a broad range of experimental processes, and complements other PSI formats for MS data and the results of protein and peptide identifications to capture entire gel-based proteome workflows. GelML has resulted from the open standardisation process of PSI consisting of both public consultation and anonymous review of the specifications.

  19. Stacking gels: A method for maximising output for pulsed-field gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Heng See

    2009-01-01

    Full Text Available Pulsed field gel electrophoresis (PFGE, the gold standard of molecular typing methods, has a major disadvantage of an unusually long electrophoretic time. From the original protocol of 6 days, it was modified to 3 days and subsequently to a single day. We describe the procedure of stacking five to six gels one on top of another in order to increase and maximize the output in a shorter time without compromising the resolution and reproducibility. All the variables that affect pulsed field gels during electrophoresis were taken into consideration. We firstly optimized the parameters to be used and secondly determined whether stacking of five to six gels had any effect on the molecular separation during electrophoresis in comparison with a single gel run. DNA preparation, restriction, electrophoresis, staining and gel documentation was carried out based on previously published methods. Gels were analysed using BioNumerics and dice coefficient and unweighted pair group methods were used to generate dendrograms based on 1.5% tolerance values. Identical band profiles and band resolution-separation were seen in the PFGE patterns with single gel and multiple stacking gels. Cluster analysis further strengthened the fact that results from stacking gels were reproducible and comparable with a single gel run. This method of stacking gels saves time and maximizes the output at the same time. The run time for a single gel was about 28 hours, but with six stacked gels the run time was 54 hours compared with 28 x 6 = 168 hours if they were run separately as single gels thus saving time of 67.86%. Beside the big factor of saving time, stacking gels save resources (electricity, reagents, water, chemicals and working time by increasing the sample throughput in a shorter time without compromising on quality of data. But optimization of working parameters is vital depending on the PFGE system used.

  20. Formation and characterization of vitreous materials prepared by the sol-gel technique

    International Nuclear Information System (INIS)

    Martinez, J.R.; Ruiz, J.F.; Cruz M, J.A. de la; Villasenor G, P.

    1999-01-01

    A full process of preparation and characterization of silica gel, which can be implemented in a experimental course for undergraduate laboratories is presented. Samples of silica gel and sol-gel derived SiO 2 films on glass substrates were fabricated and characterized using atomic force microscopy, Raman and Infrared absorption techniques. Raman and Infrared spectroscopy were used to analyze the local structure. The microstructure characteristics of the films, fabricated by dip-coating, were monitored using atomic force microscopy. The samples were prepared from alcoholic solutions of tetraethylortosilicate (TEOS) keeping the H 2 O/TEOS and Et-OH/TEOS molar ratios constant and equal to 11.66 and 4 respectively. (Author)

  1. Compositional differences in simulated root exudates elicit a limited functional and compositional response in soil microbial communities

    Directory of Open Access Journals (Sweden)

    Michael S Strickland

    2015-08-01

    Full Text Available Inputs of low molecular weight carbon (LMW-C to soil −primarily via root exudates− are expected to be a major driver of microbial activity and source of stable soil organic carbon. It is expected that variation in the type and composition of LMW-C entering soil will influence microbial community composition and function. If this is the case then short-term changes in LMW-C inputs may alter processes regulated by these communities. To determine if change in the composition of LMW-C inputs influences microbial community function and composition, we conducted a 90 day microcosm experiment whereby soils sourced from three different land covers (meadows, deciduous forests, and white pine stands were amended, at low concentrations, with one of eight simulated root exudate treatments. Treatments included no addition of LMW-C, and the full factorial combination of glucose, glycine, and oxalic acid. After 90 days, we conducted a functional response assay and determined microbial composition via phospholipid fatty acid analysis. Whereas we noted a statistically significant effect of exudate treatments, this only accounted for ~3% of the variation observed in function. In comparison, land cover and site explained ~46 and ~41% of the variation, respectively. This suggests that exudate composition has little influence on function

  2. Alkaline sodium borohydride gel as a hydrogen source for PEMFC or an energy carrier for NaBH{sub 4}-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B.H. [Department of Materials and Engineering, Zhejiang University (China); Li, Z.P.; Chen, L.L. [Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2008-05-15

    In this preliminary study, we tried to use sodium polyacrylate as the super absorbent polymer to form alkaline NaBH{sub 4} gel and explored its possibilities for borohydride hydrolysis and borohydride electro-oxidation. It was found that the absorption capacity of sodium polyacrylate decreased with increasing NaBH{sub 4} concentration. The formed gel was rather stable in the sealed vessel but tended to slowly decompose in open air. Hydrogen generation from the gel was carried out using CoCl{sub 2} catalyst precursor solutions. Hydrogen generation rate from the alkaline NaBH{sub 4} gel was found to be higher and impurities in hydrogen were less than that from the alkaline NaBH{sub 4} solution. The NaBH{sub 4} gel also successfully powered a NaBH{sub 4}-air battery. (author)

  3. Antioxidant capacity of flavonoids and a new arylphenol of the resinous exudate from Heliotropium sinuatum.

    Science.gov (United States)

    Modak, Brenda; Torres, René; Lissi, Eduardo; delle Monache, Franco

    2003-12-01

    From the resinous exudate of Heliotropium sinuatum (family Boraginaceae), a new compound: 4-(3',5'-dihydroxynonadecyl)phenol 1, together with eight previously described flavonoids, were isolated and their antioxidant activities were assessed by quenching measurements with ABTS and DPPH cation radicals.

  4. Water holding of protein gels

    NARCIS (Netherlands)

    Urbonaite, V.

    2015-01-01

    Abstract

    Food products are typically multicomponent systems, where often the spatial volume is set by a protein continuous network. The ability of protein-based food products to entrap water and to prevent its exudation upon mechanical deformation is important for the

  5. Novel polymeric systems for lithium ion batteries gel electrolytes

    International Nuclear Information System (INIS)

    Appetecchi, G.B.; Alessandrini, F.; Passerini, S.; Caporiccio, G.; Boutevin, B.; Guida-PietraSanta, F.

    2005-01-01

    Cross-linked, self-supporting, membranes for lithium ion battery gel electrolytes were obtained by cross-linking a mixture of polyfluorosilicone (PFSi) and polysilicone containing ethylene oxide (EO) units [P(Si-EO)]. The membranes were also reinforced with nanosized silica. The two polymer precursors were synthesized with functional groups capable to form inter-molecular cross-linking, thus obtaining three-dimensional, polymer matrices. The precursors were dissolved in a common solvent and cross-linked to obtain free-standing PFSi/P(Si-EO):SiO 2 composite films. The latter were undergone to swelling processes in (non-aqueous, aprotic, lithium salt containing) electrolytic solutions to obtain gel-type polymer electrolytes. The properties of the swelled PFSi/P(Si-EO):SiO 2 samples were evaluated as a function of the electrolytic solutions and the dipping time. The PFSi/P(Si-EO):SiO 2 membranes exhibited large swelling properties, high ionic conductivity and good electrochemical stability

  6. Structure and amphoteric properties of titanium dioxide gels

    International Nuclear Information System (INIS)

    Kertesz, C.

    1991-01-01

    Mechanisms responsible for the in-solution ion retention by titanium dioxide are studied. Mineral oxide gel formation and structure are described and various titanium dioxide gel synthesis modes are presented. A two-phase model, taking into account the porous nature of the solid and allowing for the application of the mass action law, is adopted. The oxide amphoteric properties are studied with the potentiometric titration technique. Hysteresis loops are imputed to the slowness of the acid-basic neutralization reaction. The main characteristics are determined: isoelectric point, cation and anion retention capacity. Depending on the suspension agitation, the speed limiting factor may be the diffusion in the film or the diffusion in the particle. 60 fig., 128 ref

  7. Evaluation of the chemical composition of Dacryodes edulis and Raphia hookeri Mann and Wendl exudates used in herbal medicine in south eastern Nigeria.

    Science.gov (United States)

    Okwu, D E; Nnamdi, Fred U

    2008-01-22

    The phytochemical contents and medicinal values of Dacroydes edulis and Raphia hookeri exudates were investigated. Phytochemical screening of the plant showed that they contain the presence of bioactive compounds comprising saponins (2.08-3.98 mg 100 g(-1)), alkaloids (0.28-0.49 mg 100 g(-1)), tannins (0.47-0.72 mg 100 g(-1)), flavonoids (0.26-0.39 mg 100 g(-1)), and phenolic compounds (0.01-0.05 mg 100 g(-1)). The carbohydrates, lipids and protein content were 77.42-78.90%, 2.02-4.185% and 16.63-18.38% respectively. The exudates are a good source of water soluble vitamins; ascorbic acid (7.04-26.40 mg 100 g(-1)), niacin (3.12-4.00 mg 100 g(-1)), riboflavin (0.14-0.54 mg 100 g(-1)) and thiamine (0.15-0.22 mg 100 g(-1)). Both plants exudates are good sources of minerals such as Ca, Mg, P, Fe, Zn, Cu and Mn while Cr and Co were trace. These results indicate that exudates can be potential sources of feedstock for the pharmaceutical industry.

  8. Ultralow-density SiO2 aerogels prepared by a two-step sol-gel process

    International Nuclear Information System (INIS)

    Wang Jue; Li Qing; Shen Jun; Zhou Bin; Chen Lingyan; Jiang; Weiyang

    1996-01-01

    Low density SiO 2 gels are prepared by a two-step sol-gel process from TEOS. The influence of various solution ratios on the gelation process is investigated. The comparative characterization of gels using different solvent, such as ethanol, acetone and methyl cyanide, is also given. The ultralow-density SiO 2 aerogels with density less than 10 kg/m 3 are prepared by CO 2 supercritical drying technique. The structure difference between SiO 2 aerogels prepared by conventional single-step process and the two-step process is also presented

  9. 99mTc gel generators based on zirconium molybdate-99Mo: III: Influence of preparatory conditions of zirconium molybdate-99Mo gel on generator performance

    International Nuclear Information System (INIS)

    Saraswathy, P.; Sarkar, S.K.; Arjun, G.; Ramamoorthy, N.; Nandy, S.K.

    2004-01-01

    The effect of subtle variations on zirconium molybdate- 99 Mo gel preparatory conditions, such as stoichiometry of reactants, pH of gel formation, conditioning of gel granules etc., prior to elution were investigated primarily to arrive at the conditions resulting in high 99m Tc release and minimal 99 Mo breakthrough upon elution with normal saline. Zirconium molybdate- 99 Mo gels were prepared by reacting solutions of Zr and Mo in mole ratios of 0.75-1.5. Both water and normal saline were used for gel disintegration, and the release of 99m Tc and 99 Mo from gel columns into eluates was compared. Sharper elution profile of 99m Tc, but with significantly higher 99 Mo breakthrough (5-8 times), was obtained when water alone was used for disintegration and elution, in comparison to when saline was used. Gels exhibiting optimum characteristics were found to be formed at a pH of 4-5 by reacting [Zr]: [Mo] in the mole ratio of 1.25: 1 and after drying, the product was dispersed into granules by disintegration with normal saline. 99m Tc elution efficiency was found to be ∝ 75% and 99 Mo breakthrough ∝ 0.05%. The elution profile was sharp when a 6 g gel column coupled to a 2 g acidic alumina column (to trap 99 Mo) was eluted with 6-9 ml normal saline. Generators containing upto 23 GBq 99 Mo were prepared, eluted extensively without changing the alumina column and found to provide pertechnetate of good quality, commensurate with hospital radiopharmacy requirements. (orig.)

  10. A case of von Hippel-Lindau disease with exudative maculopathy

    Directory of Open Access Journals (Sweden)

    Basel T Ba′arah

    2009-01-01

    Full Text Available Von Hippel-Lindau (VHL disease is a rare multisystem familial tumor syndrome of autosomal dominant inheritance. Hallmark lesions include retinal, cerebellum and spinal cord hemangioblastomas, renal cell carcinomas, adrenal pheochromocytomas, angiomatous or cystic lesions of the kidneys, pancreas, and epididymis. We report a case of VHL disease in a 26-year-old patient who presented with exudative macular edema. Ocular and systemic studies revealed the presence of retinal and central nervous system hemangioblastomas, adrenal pheochromocytoma, multiple pancreatic, and kidney cysts. The retinal angiomas were successfully treated with argon laser photocoagulation and cryotherapy.

  11. Can Wound Exudate from Venous Leg Ulcers Measure Wound Pain Status?: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Taichi Goto

    Full Text Available We investigated the associations between the self-evaluated pain status and two pain biomarker candidates, nerve growth factor and S100A8/A9, in exudate from venous leg ulcer to finally develop an objective pain evaluation method. Patients with venous leg ulcer participated in this cross-sectional observational study conducted between April and October 2014 at two medical facilities. During routine wound care, each participant self-evaluated their pain status at each examination using the 10-point numerical rating scale (present pain intensity and the short-form McGill Pain Questionnaire 2 (continuous pain, intermittent pain, neuropathic pain, affective descriptors, and total score. Venous leg ulcer exudate sample was collected after wound cleansing. The nerve growth factor and S100A8/A9 concentrations in the venous leg ulcer exudate were measured by enzyme-linked immunosorbent assay and standardized according to the wound area. The association between each pain status and the two standardized protein concentrations was evaluated using Spearman's correlation coefficient. In 30 sample collected from 13 participants, the standardized nerve growth factor concentration was negatively correlated with continuous pain (ρ = -0.47, P = 0.01, intermittent pain (ρ = -0.48, P = 0.01, neuropathic pain (ρ = -0.51, P = 0.01, and total score (ρ = -0.46, P = 0.01. The standardized S100A8/A9 concentration was positively correlated with present pain intensity (ρ = 0.46, P = 0.03 and continuous pain (ρ = 0.48, P = 0.03. Thus, these two proteins may be useful for objective evaluation of wound pain in venous leg ulcer patients.

  12. An intelligent biopolymer gel with pendant L-proline methyl ester

    International Nuclear Information System (INIS)

    Yoshida, Masaru; Safranj, A.; Omichi, Hideki; Katakai, Ryoichi.

    1995-01-01

    Linear poly(acryloyl-L-proline methyl ester, A-ProOMe), obtained by radiation-induced polymerization of its monomer in ethanol, exhibits a lower critical solution temperature (LCST) at 14degC. A-ProOMe was copolymerized with a minor amount of 2-hydroxypropyl methacrylate (HPMA) or 2-hydroxyethyl methacrylate (HEMA), to obtain intelligent biopolymer gels for application in drug delivery systems. The poly(A-ProOMe/HPMA) gel was characterized by an initial rapid shrinkage at the surface in the swollen state, as resulting in formation of a rigid membrane barrier devoid of micropores. This gel is called a surface regulated matrix. In the case of poly(A-ProOMe/HEMA), no such a barrier formed, instead, the whole matrix shrunk without the disappearance of micropores. This gel is called a matrix pumping gel. Testosterone (T) was incorporated into the poly(A-ProOMe/HPMA) gel, and it was found that the daily dose of T released in vivo from this formulation remained constant at approximately 30 μg/day throughout an experimental period of 54 weeks. On the other hand, 9-β-D-arabinofuranosyladenine (Ara-A) was incorporated into the poly(A-ProOMe/HEMA) gel to evaluate the pulsatile drug release when cycled at 10 and 37degC. The in vitro release rate of Ara-A was found to be 11 ng/h at 10degC and 33 ng/h at 37degC. (author)

  13. The influence of Uranium-Thorium ratio and heating time during gelation using as a CCl4(NH3) on the Gel quality

    International Nuclear Information System (INIS)

    Indra-Suryawan; Sukarsono, R; Setyo-Sulardi

    1996-01-01

    Gel has been prepared from a uranium-thorium sol using CCI 4 (NH 3 ) as a gelling medium. The uranium-thorium ratio and the heating time during gelation have been chosen as variables. The sol was prepared by mixing Th(NO 3 ) 4 and UO 2 (NO 3 ) 2 solutions, heating the solution at 95 o C and adding NH 4 OH solution drop by drop until colloidal particles were formed. Sol was then fed into a gelation column containing CCI 4 (NH 3 ), where the sol was transformed into gel. A good gel has properties such as sphere in shape and elastic which it will not crack when it is dropped from 2 metres height. The experimental work resulted a good gel when the percentage of uranium was about 15 - 25 % at heating time of 40 - 50 minutes

  14. PERBANDINGAN KEMAMPUAN SILIKA GEL DARI ABU SABUT KELAPA DAN ABU SEKAM PADI UNTUK MENURUNKAN KADAR LOGAM Cd2+

    Directory of Open Access Journals (Sweden)

    AF Yusrin

    2015-07-01

    Full Text Available Penelitian mengenai pembuatan silika gel dari bahan baku abu sabut kelapa (ASK dan abu sekam padi (ASP telah dilakukan dengan memanfaatkan kandungan silikanya. Bahan baku ASK dan ASP ditambah larutan NaOH dengan pemanasan dan peleburan pada suhu 500C selama 30 menit menghasilkan larutan natrium silikat, kemudian larutan natrium silikat masing-masing diasamkan dengan HCl 3 M hingga pH 7 dan dikeringkan hingga menjadi silika gel abu sabut kelapa (SG-ASK dan silika gel abu sekam padi (SG-ASP. Hasil karakterisasi XRD menyatakan bahwa SG-ASK dan SG-ASP menghasilkan silika berbentuk amorf, sedangkan hasil analisis FT-IR menyatakan bahwa silika gel memiliki gugus fungsi Si-OH, Si-O dan Si-H. Hasil penelitian mengenai uji penyerapan ion logam Cd2+ menunjukkan bahwa penyerapan optimum ion logam Cd2+ dalam larutan oleh SG-ASK adalah pada pH 6, waktu kontak 60 menit dan konsentrasi optimum 7,45 ppm. Hasil uji penyerapan optimum ion logam Cd2+ dalam larutan oleh SG-ASP pada pH 7, waktu kontak 90 menit dan konsentrasi optimum 11,78 ppm. Hasil penelitian menunjukkan bahwa kemampuan SG-ASP lebih besar dibandingkan dengan kemampuan SG-ASK dalam menurunkan kadar ion logam Cd2+ dalam larutan.Research on the manufacture of gel silica from coconut husk ash (ASK and rice husk ash (ASP has been conducted by utilizing their silica contents. ASK and ASP were added by an NaOH solution, then by heated and melted at temperature 500C for 30 minutes to produce sodium silicate solution. The solution was then acidified separately with HCl 3 M up to pH 7 and dried into silica gel of coconut husk ash (SG-ASK and silica gel of rice husk ash (SG-ASP. The result of XRD characterization showed that SG-ASK and SG-ASP both produced amorphous silica, while the result of FT-IR analysis showed that silica gel had functional groups of Si-OH, Si-O and Si-H. The research on the test adsorption of Cd2+ metal ions showed that the optimum adsorption of Cd2+ metal ions in solution by SG

  15. Detection of human DNA polymorphisms with a simplified denaturing gradient gel electrophoresis technique

    International Nuclear Information System (INIS)

    Noll, W.W.; Collins, M.

    1987-01-01

    Single base pair differences between otherwise identical DNA molecules can result in altered melting behavior detectable by denaturing gradient gel electrophoresis. The authors have developed a simplified procedure for using denaturing gradient gel electrophoresis to detect base pair changes in genomic DNA. Genomic DNA is digested with restriction enzymes and hybridized in solution to labeled single-stranded probe DNA. The excess probe is then hybridized to complementary phage M13 template DNA, and the reaction mixture is electrophoresed on a denaturing gradient gel. Only the genomic DNA probe hybrids migrate into the gel. Differences in hybrid mobility on the gel indicate base pair changes in the genomic DNA. They have used this technique to identify two polymorphic sites within a 1.2-kilobase region of human chromosome 20. This approach should greatly facilitate the identification of DNA polymorphisms useful for gene linkage studies and the diagnosis of genetic diseases

  16. Electrochemical corrosion behavior of composite MAO/sol-gel coatings on magnesium alloy AZ91D using combined micro-arc oxidation and sol-gel technique

    International Nuclear Information System (INIS)

    Shang Wei; Chen Baizhen; Shi Xichang; Chen Ya; Xiao Xiang

    2009-01-01

    Protective composite coatings were obtained on a magnesium alloy by micro-arc oxidation (MAO) and sol-gel technique. The coatings consisted of a MAO layer and a sol-gel layer. The microstructure and composition of the MAO coating and the composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and total immersion tests were used to evaluate the corrosion behavior of these coatings in a 3.5 wt.% NaCl solution. The results show that the sol-gel layer provides corrosion protection by physically sealing the pores in the MAO coating and acting as a barrier. The composite coatings can suppress the corrosion process by preventing the corrosive ions from transferring or diffusing to the magnesium alloy substrate. This enhances the corrosion resistance of the magnesium alloy AZ91D significantly

  17. Nitrate Protects Cucumber Plants Against Fusarium oxysporum by Regulating Citrate Exudation.

    Science.gov (United States)

    Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Sun, Guomei; Zhu, Chen; Guo, Shiwei; Shen, Qirong

    2016-09-01

    Fusarium wilt causes severe yield losses in cash crops. Nitrogen plays a critical role in the management of plant disease; however, the regulating mechanism is poorly understood. Using biochemical, physiological, bioinformatic and transcriptome approaches, we analyzed how nitrogen forms regulate the interactions between cucumber plants and Fusarium oxysporum f. sp. cucumerinum (FOC). Nitrate significantly suppressed Fusarium wilt compared with ammonium in both pot and hydroponic experiments. Fewer FOC colonized the roots and stems under nitrate compared with ammonium supply. Cucumber grown with nitrate accumulated less fusaric acid (FA) after FOC infection and exhibited increased tolerance to chemical FA by decreasing FA absorption and transportation in shoots. A lower citrate concentration was observed in nitrate-grown cucumbers, which was associated with lower MATE (multidrug and toxin compound extrusion) family gene and citrate synthase (CS) gene expression, as well as lower CS activity. Citrate enhanced FOC spore germination and infection, and increased disease incidence and the FOC population in ammonium-treated plants. Our study provides evidence that nitrate protects cucumber plants against F. oxysporum by decreasing root citrate exudation and FOC infection. Citrate exudation is essential for regulating disease development of Fusarium wilt in cucumber plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Exudate Chemical Profiles Derived from Lespedeza and Other Tallgrass Prairie Plant Species

    Science.gov (United States)

    2017-05-01

    Chemical Profiles Derived from Lespedeza and Other Tall- grass Prairie Plant Species. ERDC TN-17-1. Vicksburg, MS: U.S. Army Engineer Re- search and...200-1-52. Washington, DC: U.S. Army Corps of Engineers Headquarters, Civil Works. https://www.wbdg.org/ffc/army-coe/public-works-technical-bulletins...ERDC TN-17-1 May 2017 Approved for public release; distribution is unlimited. Exudate Chemical Profiles Derived from Lespedeza and Other

  19. Remineralizing Efficacy of Fluorohydroxyapatite Gel on Artificial Dentinal Caries Lesion

    Directory of Open Access Journals (Sweden)

    Qianqian Wang

    2015-01-01

    Full Text Available The aim was to evaluate the remineralizing efficacy of fluorohydroxyapatite (FHA gel on artificial dentinal caries lesion in vitro. Artificial carious lesions were made on occlusal cavities of teeth by exposing the dentin surface to a demineralizing solution. Each cavity was capped with a 3 mm thick FHA gel for 4 weeks. After the FHA gel was removed, the surface morphology and structure of the dentin were characterized by scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FT-IR. The dentin mineral density (DMD was measured by micro-computed tomography (Micro-CT. A layer of dense and orderly hexagonal crystal structure, with average diameter of 1 μm and thickness of 4~5 μm, could be observed on dentin surface. These crystals exhibited elemental peaks for calcium, phosphorus, carbon, and oxygen and characteristic peaks of hydroxyapatite (HA and fluorapatite (FA via XRD and FT-IR. The DMD of dentin surface layer significantly increased after it was capped with FHA gel (P<0.05. In the present study, the FHA gel could rapidly construct apatite on the artificial dentin caries surface and significantly increase the mineral density, which suggests that FHA gel might be a proper IPT material with remineralizing function.

  20. Fabrication of YBa2Cu3O7-δ superconducting fibers by the sol-gel method

    International Nuclear Information System (INIS)

    Umeda, Tetsu; Kozuka, Hiromitsu; Sakka, Sumio

    1988-01-01

    High-T c superconducting oxide fibers were fabricated by the sol-gel method. An aqueous solution of metal acetates was concentrated to form a viscous sol, from which gel fibers were spun. The gel fibers, 5 to 1,000 μm in diameter, were converted to ceramic fibers by heating to 900 degree C. The fired fibers (T c (onset) of 94 K and T c (end) of 62.2 K) were rough and had porous microstructures

  1. A new sol-gel synthesis of 45S5 bioactive glass using an organic acid as catalyst.

    Science.gov (United States)

    Faure, J; Drevet, R; Lemelle, A; Ben Jaber, N; Tara, A; El Btaouri, H; Benhayoune, H

    2015-02-01

    In this paper a new sol-gel approach was explored for the synthesis of the 45S5 bioactive glass. We demonstrate that citric acid can be used instead of the usual nitric acid to catalyze the sol-gel reactions. The substitution of nitric acid by citric acid allows to reduce strongly the concentration of the acid solution necessary to catalyze the hydrolysis of silicon and phosphorus alkoxides. Two sol-gel powders with chemical compositions very close to that of the 45S5 were obtained by using either a 2M nitric acid solution or either a 5mM citric acid solution. These powders were characterized and compared to the commercial Bioglass®. The surface properties of the two bioglass powders were assessed by scanning electron microscopy (SEM) and by Brunauer-Emmett-Teller method (BET). The Fourier transformed infrared spectroscopy (FTIR) and the X-ray diffraction (XRD) revealed a partial crystallization associated to the formation of crystalline phases on the two sol-gel powders. The in vitro bioactivity was then studied at the key times during the first hours of immersion into acellular Simulated Body Fluid (SBF). After 4h immersion into SBF we clearly demonstrate that the bioactivity level of the two sol-gel powders is similar and much higher than that of the commercial Bioglass®. This bioactivity improvement is associated to the increase of the porosity and the specific surface area of the powders synthesized by the sol-gel process. Moreover, the nitric acid is efficiently substituted by the citric acid to catalyze the sol-gel reactions without alteration of the bioactivity of the 45S5 bioactive glass. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Adsorption of H[Ru(III) Cl2(H2EDTA)] complex on modified silica gel surface with [3-(2-aminoethyl)aminopropyl] trimethoxysilane in ethanol solutions

    International Nuclear Information System (INIS)

    Lazarin, Angelica Machi; Sernaglia, Rosana Lazara

    1999-01-01

    Silica gel was functionalized with [3-(2-aminoethyl) aminopropyl] trimethoxysilane group (SF-AEATS) and the characterization by chemical analysis (N) and infrared spectroscopy confirmed the functionalization. The capacity of the modified silica to adsorb the complex Ru (III) EDTA from ethanolic solution was studied. The selectivity coefficients of the complex formed on the support obtained was τn), 2,07 x 10 4 L/mol and the average number of ligand bonded by one metal ion on the support (n) was ∼1. (author)

  3. Influence of aluminum on growth, mineral nutrition and organic acid exudation of rambutan (Nephelium lappaceum)

    Science.gov (United States)

    A randomized complete block design experiment with six aluminum (Al) concentrations was carried out to evaluate the effect of aluminum on nutrient content, plant growth, dry matter production and Al-induced organic acid exudation in rambutan (Nephelium lappaceum). One rambutan cultivar was grown in...

  4. Deposition of tin oxide doped with fluorine produced by sol-gel method and deposited by spray-pyrolysis

    International Nuclear Information System (INIS)

    Maia, Paulo Herbert Franca; Lima, Francisco Marcone; Sena, Aline Cosmo de; Silva, Alvaro Neuton; Almeida, Ana Fabiola Leite de; Freire, Francisco Nivaldo Aguiar

    2014-01-01

    Solar energy is one of the most important sources of renewable energy today, but its production is based on silicon cells, expensive and difficult to produce, so the research seek new materials to replace them. This work aims to deposit tin oxide doped with fluorine on the glass substrate using the sol-gel method to provide a working solution and spray pyrolysis technique to perform the deposition. F-SnO2 (FTO) were synthesized by sol-gel method, employing NH_4F and SnCl_2 precursor in an ethanol solution. Before the formation of the gel phase, the entire solution was sprayed, with the aid of a pistol aerographic substrate under heated at 600 °C divided by 50 applications and cooled in the furnace. The substrates had resistances between 10 and 30 S.cm. The energy dispersive x-ray (EDS) revealed the presence of fluorine in the SnO_2 network. (author)

  5. Ternary Phase-Separation Investigation of Sol-Gel Derived Silica from Ethyl Silicate 40

    Science.gov (United States)

    Wang, Shengnan; Wang, David K.; Smart, Simon; Diniz da Costa, João C.

    2015-01-01

    A ternary phase-separation investigation of the ethyl silicate 40 (ES40) sol-gel process was conducted using ethanol and water as the solvent and hydrolysing agent, respectively. This oligomeric silica precursor underwent various degrees of phase separation behaviour in solution during the sol-gel reactions as a function of temperature and H2O/Si ratios. The solution composition within the immiscible region of the ES40 phase-separated system shows that the hydrolysis and condensation reactions decreased with decreasing reaction temperature. A mesoporous structure was obtained at low temperature due to weak drying forces from slow solvent evaporation on one hand and formation of unreacted ES40 cages in the other, which reduced network shrinkage and produced larger pores. This was attributed to the concentration of the reactive sites around the phase-separated interface, which enhanced the condensation and crosslinking. Contrary to dense silica structures obtained from sol-gel reactions in the miscible region, higher microporosity was produced via a phase-separated sol-gel system by using high H2O/Si ratios. This tailoring process facilitated further condensation reactions and crosslinking of silica chains, which coupled with stiffening of the network, made it more resistant to compression and densification. PMID:26411484

  6. Fabrication of Sericin/Agrose Gel Loaded Lysozyme and Its Potential in Wound Dressing Application

    Directory of Open Access Journals (Sweden)

    Meirong Yang

    2018-04-01

    Full Text Available Sericin is a biomaterial resource for its significant biodegradability, biocompatibility, hydrophilicity, and reactivity. Designing a material with superabsorbent, antiseptic, and non-cytotoxic wound dressing properties is advantageous to reduce wound infection and promote wound healing. Herein, we propose an environment-friendly strategy to obtain an interpenetrating polymer network gel through blending sericin and agarose and freeze-drying. The physicochemical characterizations of the sericin/agarose gel including morphology, porosity, swelling behavior, crystallinity, secondary structure, and thermal property were well characterized. Subsequently, the lysozyme loaded sericin/agarose composite gel was successfully prepared by the solution impregnation method. To evaluate the potential of the lysozyme loaded sericin/agarose gel in wound dressing application, we analyzed the lysozyme loading and release, antimicrobial activity, and cytocompatibility of the resulting gel. The results showed the lysozyme loaded composite gel had high porosity, excellent water absorption property, and good antimicrobial activities against Escherichia coli and Staphylococcus aureus. Also, the lysozyme loaded gel showed excellent cytocompatibility on NIH3T3 and HEK293 cells. So, the lysozyme loaded sericin/agarose gel is a potential alternative biomaterial for wound dressing.

  7. Controlled Sol-Gel Transitions of a Thermoresponsive Polymer in a Photoswitchable Azobenzene Ionic Liquid as a Molecular Trigger.

    Science.gov (United States)

    Wang, Caihong; Hashimoto, Kei; Tamate, Ryota; Kokubo, Hisashi; Watanabe, Masayoshi

    2018-01-02

    Producing ionic liquids (ILs) that function as molecular trigger for macroscopic change is a challenging issue. Photoisomerization of an azobenzene IL at the molecular level evokes a macroscopic response (light-controlled mechanical sol-gel transitions) for ABA triblock copolymer solutions. The A endblocks, poly(2-phenylethyl methacrylate), show a lower critical solution temperature in the IL mixture containing azobenzene, while the B midblock, poly(methyl methacrylate), is compatible with the mixture. In a concentrated polymer solution, different gelation temperatures were observed in it under dark and UV conditions. Light-controlled sol-gel transitions were achieved by a photoresponsive solubility change of the A endblocks upon photoisomerization of the azobenzene IL. Therefore, an azobenzene IL as a molecular switch can tune the self-assembly of a thermoresponsive polymer, leading to macroscopic light-controlled sol-gel transitions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Purification, characterization and cloning of an aspartic proteinase inhibitor from squash phloem exudate.

    Science.gov (United States)

    Christeller, J T; Farley, P C; Ramsay, R J; Sullivan, P A; Laing, W A

    1998-05-15

    Phloem exudate from squash fruit contains heat-inactivated material which inhibits pepsin activity. This inhibitory activity was purified by mild acid treatment, chromatography on trypsin-agarose, Sephadex G-75 and reverse-phase HPLC, resulting in the elution of three peaks with pepsin-inhibitory activity. N-terminal sequencing indicated a common sequence of MGPGPAIGEVIG and the presence of minor species with seven- or two-amino-acid N-terminal extensions beyond this point. Microheterogeneity in this end sequence was exhibited within and between two preparations. Internal sequencing of a major peak after a trypsin digestion gave the sequence FYNVVVLEK. The common N-terminal sequence was used to design a degenerate primer for 3' rapid amplification of cDNA ends and cDNA clones encoding two isoforms of the inhibitor were obtained. The open reading frames of both cDNAs encoded proteins (96% identical) which contained the experimentally determined internal sequence. The amino acid content calculated from the predicted amino acid sequence was very similar to that measured by amino acid analysis of the purified inhibitor. The two predicted amino acid sequences (96 residues) had neither similarity to any other aspartic proteinase inhibitor nor similarity to any other protein. The inhibitors have a molecular mass of 10,552 Da, measured by matrix-assisted laser-desorption ionisation time-of-flight mass spectrometry and approximately 10,000 Da by SDS/PAGE, and behave as dimers of approximately 21,000 Da during chromatography on Superdex G-75 gel-filtration medium. The calculated molecular masses from the predicted amino acid sequences were 10,551 Da and 10,527 Da. The inhibitor was capable of inhibiting pepsin (Ki = 2 nM) and a secreted aspartic proteinase from the fungus Glomerella cingulata (Ki = 20 nM). The inhibitor, which is stable over acid and neutral pH, has been named squash aspartic proteinase inhibitor (SQAPI).

  9. Both heavy metal-amendment of soil and aphid-infestation increase Cd and Zn concentrations in phloem exudates of a metal-hyperaccumulating plant.

    Science.gov (United States)

    Stolpe, Clemens; Giehren, Franziska; Krämer, Ute; Müller, Caroline

    2017-07-01

    Plants that are able to hyperaccumulate heavy metals show increased concentrations of these metals in their leaf tissue. However, little is known about the concentrations of heavy metals and of organic defence metabolites in the phloem sap of these plants in response to either heavy metal-amendment of the soil or biotic challenges such as aphid-infestation. In this study, we investigated the effects of heavy metal-exposure and of aphid-infestation on phloem exudate composition of the metal hyperaccumulator species Arabidopsis halleri L. O'Kane & Al-Shehbaz (Brassicaceae). The concentrations of elements and of organic defence compounds, namely glucosinolates, were measured in phloem exudates of young and old (mature) leaves of plants challenged either by amendment of the soil with cadmium and zinc and/or by an infestation with the generalist aphid Myzus persicae. Metal-amendment of the soil led to increased concentrations of Cd and Zn, but also of two other elements and one indole glucosinolate, in phloem exudates. This enhanced defence in the phloem sap of heavy metal-hyperaccumulating plants can thus potentially act as effective protection against aphids, as predicted by the elemental defence hypothesis. Aphid-infestation also caused enhanced Cd and Zn concentrations in phloem exudates. This result provides first evidence that metal-hyperaccumulating plants can increase heavy metal concentrations tissue-specifically in response to an attack by phloem-sucking herbivores. Overall, the concentrations of most elements, including the heavy metals, and glucosinolates were higher in phloem exudates of young leaves than in those of old leaves. This defence distribution highlights that the optimal defence theory, which predicts more valuable tissue to be better defended, is applicable for both inorganic and organic defences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Extraction of lanthanides ions (III) from aqueous solution by sodium salt of the N(4-amino-benzoate)-propyl-silica gel

    International Nuclear Information System (INIS)

    Retamero, R.C.

    1991-01-01

    The silica gel 60 of specific superficial area 486 m 2 .g -1 was modified chemically with the ligand 4-amino benzoate of sodium in water-ethanol environment (l:L). The adsorptions of metallic ions were from water solutions at approximately 2 x 10 -3 M of chloride of Pr(III), Nd(III), Eu(III) and Ho(III). In these experiments we could see that the system gets the equilibrium of adsorption rapidly and that the pH of the environment has a great influence on the process of adsorption, being that the number of metal mols adsorpted in the matrix varied between 10,00 and 17,00 x 10 -5 mols. g -1 with a pH of approximately 5 for all the lanthanides, where the adsorption curves reach equilibrium. (author)

  11. Detection of human DNA polymorphisms with a simplified denaturing gradient gel electrophoresis technique.

    OpenAIRE

    Noll, W W; Collins, M

    1987-01-01

    Single base pair differences between otherwise identical DNA molecules can result in altered melting behavior detectable by denaturing gradient gel electrophoresis. We have developed a simplified procedure for using denaturing gradient gel electrophoresis to detect base pair changes in genomic DNA. Genomic DNA is digested with restriction enzymes and hybridized in solution to labeled single-stranded probe DNA. The excess probe is then hybridized to complementary phage M13 template DNA, and th...

  12. Transport Phenomena in Gel

    Directory of Open Access Journals (Sweden)

    Masayuki Tokita

    2016-05-01

    Full Text Available Gel becomes an important class of soft materials since it can be seen in a wide variety of the chemical and the biological systems. The unique properties of gel arise from the structure, namely, the three-dimensional polymer network that is swollen by a huge amount of solvent. Despite the small volume fraction of the polymer network, which is usually only a few percent or less, gel shows the typical properties that belong to solids such as the elasticity. Gel is, therefore, regarded as a dilute solid because its elasticity is much smaller than that of typical solids. Because of the diluted structure, small molecules can pass along the open space of the polymer network. In addition to the viscous resistance of gel fluid, however, the substance experiences resistance due to the polymer network of gel during the transport process. It is, therefore, of importance to study the diffusion of the small molecules in gel as well as the flow of gel fluid itself through the polymer network of gel. It may be natural to assume that the effects of the resistance due to the polymer network of gel depends strongly on the network structure. Therefore, detailed study on the transport processes in and through gel may open a new insight into the relationship between the structure and the transport properties of gel. The two typical transport processes in and through gel, that is, the diffusion of small molecules due to the thermal fluctuations and the flow of gel fluid that is caused by the mechanical pressure gradient will be reviewed.

  13. Effects of cadmium amendments on low-molecular-weight organic acid exudates in rhizosphere soils of tobacco and sunflower.

    Science.gov (United States)

    Chiang, Po-Neng; Wang, Ming Kuang; Chiu, Chih Yu; Chou, Shu-Yen

    2006-10-01

    To recognize physiological response of plants to cadmium (Cd) toxicity in rhizosphere of plants, the pot experiments were employed to investigate how low-molecular-weight organic acids (LMWOAs) were exudated from tobacco and sunflower roots of Cd-amended soils. The aims of this study were to assess the effect of LMWOAs on uptake of Cd by tobacco and sunflower under pot experiments, thus comparing the ability of tobacco and sunflower for phytoremediation. Surface soils (0-20 cm) were collected from Taichung Experiment Station (TC) (silty loam). Cadmium chloride (CdCl(2)) was amended into TC soil, giving Cd concentrations of 1, 5, 10 mg kg(-1) soil. Soils with different concentrations of Cd were put into 12 cm (i.d.) pots for incubation, and then 2-week-old tobacco and sunflower seedlings were transplanted into the pots. Tobacco and sunflower were grown in greenhouse for 50 days, respectively. The rhizosphere and bulk soils, and fresh plant tissues were collected after harvest. The Cd concentrations in the plant and transfer factor values in the sunflower were higher than that in the tobacco. No LMWOAs were detected by gas chromatograph in bulk soils, and low amounts of LMWOAs were found in uncontaminated rhizosphere soils. Acetic, lactic, glycolic, malic, maleic, and succinic acids were found in the tobacco and sunflower rhizosphere soils. Concentrations of LMWOAs increased with increasing amendment of Cd concentrations in tobacco and sunflower rhizosphere soils. Correlation coefficient (r) of concentrations of Cd amendment versus LMWOAs exudates of tobacco and sunflower were 0.85 and 0.98, respectively. These results suggest that the different levels of LMWOAs present in the rhizosphere soil play an important role in the solubilization of Cd that bound with soil particle into soil solution and then uptake by plants.

  14. Luminescent hybrid porphyrinosilica obtained by sol gel chemistry

    Directory of Open Access Journals (Sweden)

    Neri Cláudio Roberto

    2003-01-01

    Full Text Available The sol-gel process is a methodology used to obtain organic-inorganic hybrid solids, which open new possibilities in the field of material science. The sol-gel technique offers a low temperature attractive approach for introducing organic molecules into amorphous materials. In order to introduce tetrakis (2-hydroxy-5-nitrophenylporphyrin covalently bounded to a silicate matrix, the inorganic precursor 3-isocyanatopropyltriethoxysilane was added (molar ratio 2:1 to the porphyrin solution in anhydrous dimethylformamide and triethylamine. The isolated porphyrin and the hybrid porphyrinosilica have excitation maximum centred at 400 nm and 424 nm, respectively and the emission spectra for both materials has bands centred at 650 nm and 713 nm. The formation of hybrid matrix was investigated by FTIR.

  15. Plant-microbe rhizosphere interactions mediated by Rehmannia glutinosa root exudates under consecutive monoculture

    Science.gov (United States)

    Wu, Linkun; Wang, Juanying; Huang, Weimin; Wu, Hongmiao; Chen, Jun; Yang, Yanqiu; Zhang, Zhongyi; Lin, Wenxiong

    2015-10-01

    Under consecutive monoculture, the biomass and quality of Rehmannia glutinosa declines significantly. Consecutive monoculture of R. glutinosa in a four-year field trial led to significant growth inhibition. Most phenolic acids in root exudates had cumulative effects over time under sterile conditions, but these effects were not observed in the rhizosphere under monoculture conditions. It suggested soil microbes might be involved in the degradation and conversion of phenolic acids from the monocultured plants. T-RFLP and qPCR analysis demonstrated differences in both soil bacterial and fungal communities during monoculture. Prolonged monoculture significantly increased levels of Fusarium oxysporum, but decreased levels of Pseudomonas spp. Abundance of beneficial Pseudomonas spp. with antagonistic activity against F. oxysporum was lower in extended monoculture soils. Phenolic acid mixture at a ratio similar to that found in the rhizosphere could promote mycelial growth, sporulation, and toxin (3-Acetyldeoxynivalenol, 15-O-Acetyl-4-deoxynivalenol) production of pathogenic F. oxysporum while inhibiting growth of the beneficial Pseudomonas sp. W12. This study demonstrates that extended monoculture can alter the microbial community of the rhizosphere, leading to relatively fewer beneficial microorganisms and relatively more pathogenic and toxin-producing microorganisms, which is mediated by the root exudates.

  16. Densification and crystallization behaviour of colloidal cordierite-type gels

    Directory of Open Access Journals (Sweden)

    LJILJANA KOSTIC-GVOZDENOVIC

    2001-05-01

    Full Text Available Three cordierite-type gels were prepared from an aqueous solution of Mg(NO32, a boehmite sol and silica sols of very small particle sizes. The effect of varying the silica particle size on the crystallization and densification behaviour was studied. Phase development was examined by thermal analysis and X-ray diffraction, while the densification behaviour was characterized by measuring the linear shrinkage of pellets. The activation energy of densification by viscous flow was determined using the Franckel model for non-isothermal conditions and a constant heating rate. The results show that spinel crystallizes from the colloidal gels prior to cristobalite, and their reaction gives a-cordierite, which is specific for three-phase gels. Decreasing the silica particles size lowers the cristobalite crystallization temperature and the a-cordierite formation temperature. The activation energy of densification by viscous flow is lower and the densification more efficient, the smaller the silica particles are.

  17. A relationship between Gel'fand-Levitan and Marchenko kernels

    International Nuclear Information System (INIS)

    Kirst, T.; Von Geramb, H.V.; Amos, K.A.

    1989-01-01

    An integral equation which relates the output kernels of the Gel'fand-Levitan and Marchenko inverse scattering equations is specified. Structural details of this integral equation are studied when the S-matrix is a rational function, and the output kernels are separable in terms of Bessel, Hankel and Jost solutions. 4 refs

  18. 14CO2 labeling: a reliable technique for rapid measurement of total root exudation capacity and vascular sap flow in crops

    International Nuclear Information System (INIS)

    Singh, Bhupinder; Ahuja, Sumedha; Pandey, Renu; Singhal, R.K.

    2014-01-01

    Ability of roots to release organic compounds in its rhizosphere is known to improve plant available nutrients and reduces heavy metal toxicity by immobilization. It is regarded as an important determinant of micro nutrient deficiency tolerance in plants. Uptake of nutrients and translocation of photoassimilates, on the other hand are governed by the strength of the transpiration stream and sink demand respectively. Measurement of vascular sap flow, thus, is critical for understanding of the translocation efficiency and consequently the sink demand that keeps changing during the crop growth cycle. Measurement of the root exudation capacity and the vascular sap flow is cumbersome and time consuming. Since, the exudates released by the roots and the photosynthates translocated between the source and the sink are essentially carbon compounds, use of labeled carbon as tag could potentially be exploited for a rapid and reliable measurement of exudation and vascular sap flow in crop plants. We report here the experimental results involving 14 C labeling of groundnut, a legume crop, as 14 CO 2 generated by acidification of sodium bicarbonate. An additional factor of seed gamma irradiation was used to generate variability in the root exudation and the sap flow. The 14 C release by the roots was compared against the 14 C transport in the vascular sap. An experimental hypothesis that a higher 14 C level in the vascular sap would indicate a higher root release of carbon by the roots into the rhizosphere was verified. (author)

  19. Functionalizable Sol-Gel Silica Coatings for Corrosion Mitigation

    Science.gov (United States)

    Gąsiorek, Jolanta; Babiarczuk, Bartosz; Kaleta, Jerzy; Jones, Walis; Krzak, Justyna

    2018-01-01

    Corrosion is constantly a major problem of the world economy in the field of metal products, metal processing and other areas that utilise metals. Previously used compounds utilizing hexavalent chromium were amongst the most effective materials for corrosion protection but regulations have been recently introduced that forbid their use. Consequently, there is a huge drive by engineers, technologists and scientists from different disciplines focused on searching a new, more effective and environmentally-friendly means of corrosion protection. One novel group of materials with the potential to solve metal protection problems are sol-gel thin films, which are increasingly interesting as mitigation corrosion barriers. These environmentally-friendly and easy-to-obtain coatings have the promise to be an effective alternative to hexavalent chromium compounds using for anti-corrosion industrial coatings. In this review the authors present a range of different solutions for slow down the corrosion processes of metallic substrates by using the oxides and doped oxides obtained by the sol-gel method. Examples of techniques used to the sol-gel coating examinations, in terms of anti-corrosion protection, are also presented. PMID:29373540

  20. Functionalizable Sol-Gel Silica Coatings for Corrosion Mitigation.

    Science.gov (United States)

    Gąsiorek, Jolanta; Szczurek, Anna; Babiarczuk, Bartosz; Kaleta, Jerzy; Jones, Walis; Krzak, Justyna

    2018-01-26

    Corrosion is constantly a major problem of the world economy in the field of metal products, metal processing and other areas that utilise metals. Previously used compounds utilizing hexavalent chromium were amongst the most effective materials for corrosion protection but regulations have been recently introduced that forbid their use. Consequently, there is a huge drive by engineers, technologists and scientists from different disciplines focused on searching a new, more effective and environmentally-friendly means of corrosion protection. One novel group of materials with the potential to solve metal protection problems are sol-gel thin films, which are increasingly interesting as mitigation corrosion barriers. These environmentally-friendly and easy-to-obtain coatings have the promise to be an effective alternative to hexavalent chromium compounds using for