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Sample records for alkaline sucrose density

  1. Rev1, Rev3, or Rev7 siRNA Abolishes Ultraviolet Light-Induced Translesion Replication in HeLa Cells: A Comprehensive Study Using Alkaline Sucrose Density Gradient Sedimentation

    PubMed Central

    Takezawa, Jun; Ishimi, Yukio; Aiba, Naomi; Yamada, Kouichi

    2010-01-01

    When a replicative DNA polymerase stalls upon encountering a lesion on the template strand, it is relieved by other low-processivity polymerase(s), which insert nucleotide(s) opposite the lesion, extend by a few nucleotides, and dissociate from the 3′-OH. The replicative polymerase then resumes DNA synthesis. This process, termed translesion replication (TLS) or replicative bypass, may involve at least five different polymerases in mammals, although the participating polymerases and their roles have not been entirely characterized. Using siRNAs originally designed and an alkaline sucrose density gradient sedimentation technique, we verified the involvement of several polymerases in ultraviolet (UV) light-induced TLS in HeLa cells. First, siRNAs to Rev3 or Rev7 largely abolished UV-TLS, suggesting that these 2 gene products, which comprise Polζ, play a main role in mutagenic TLS. Second, Rev1-targeted siRNA also abrogated UV-TLS, indicating that Rev1 is also indispensable to mutagenic TLS. Third, Polη-targeted siRNA also prevented TLS to a greater extent than our expectations. Forth, although siRNA to Polι had no detectable effect, that to Polκ delayed UV-TLS. To our knowledge, this is the first study reporting apparent evidence for the participation of Polκ in UV-TLS. PMID:21151666

  2. Characterization of a novel low-temperature-active, alkaline and sucrose-tolerant invertase

    PubMed Central

    Zhou, Junpei; He, Limei; Gao, Yajie; Han, Nanyu; Zhang, Rui; Wu, Qian; Li, Junjun; Tang, Xianghua; Xu, Bo; Ding, Junmei; Huang, Zunxi

    2016-01-01

    A glycoside hydrolase family 32 invertase from Bacillus sp. HJ14 was expressed in Escherichia coli. The purified recombinant enzyme (rInvHJ14) showed typical biochemical properties of low-temperature-active and alkaline enzymes: (i) rInvHJ14 was active and stable in the range of pH 7.0–9.5 with an apparent pH optimum of 8.0; (ii) rInvHJ14 was most active but not stable at 30–32.5 °C, with 19.7, 48.2 and 82.1% of its maximum activity when assayed at 0, 10 and 20 °C, respectively, and the Ea, ΔG* (30 °C), Km (30 °C) and kcat (30 °C) values for hydrolysis of sucrose by rInvHJ14 was 47.6 kJ mol−1, 57.6 kJ mol−1, 62.9 mM and 746.2 s−1, respectively. The enzyme also showed strong sucrose tolerance. rInvHJ14 preserved approximately 50% of its highest activity in the presence of 2045.0 mM sucrose. Furthermore, potential factors for low-temperature-active and alkaline adaptations of rInvHJ14 were presumed. Compared with more thermostable homologs, rInvHJ14 has a higher frequency of glycine residues and a longer loop but a lower frequency of proline residues (especially in a loop) in the catalytic domain. The catalytic pockets of acid invertases were almost negatively charged while that of alkaline rInvHJ14 was mostly positively charged. PMID:27553125

  3. Determination of the specific gravity of certain helminth eggs using sucrose density gradient centrifugation.

    PubMed

    David, E D; Lindquist, W D

    1982-10-01

    The specific gravities of ten species of helminth eggs were determined using sucrose density gradient centrifugation. Fecal or egg concentrate was layered over a 3 to 54% sucrose density gradient. The gradient was then centrifuged at 800 g for 20 min, allowing 5 min for acceleration and 5 for deceleration. Bands formed were identified and measured. Refractive index was measured at the middle of narrow bands, or at the level at which the concentration of eggs was highest, in the case of wide bands or when no band was formed. The specific gravity corresponding to this refractive index was taken as the specific gravity of the eggs. The ten species of helminth eggs studied and specific gravities measured on three or four gradients were: Toxascaris leonina, 1.0559; Ancylostoma caninum, 1.0559; Toxocara canis, 1.0900; Parascaris equorum, 1.0969; Toxocara cati (embryonated), 1.1005; Ascaris suum, 1.1299; Trichuris suis, 1.1299; Trichuris vulpis, 1.1453; Taenia sp., 1.2251; and Physaloptera sp., 1.2376. These determinations agree with or approximate those of previous workers. The specific gravities of P. equorum, T. suis, Taenia sp., and Physaloptera sp., are reported for the first time.

  4. [The study of the growth of tylosin producer using differential centrifugation of mycelium in a sucrose density gradient].

    PubMed

    Salamakha, O V; Rogatykh, N P; Savochkina, I V; Tikhomirova, L A; Bazarenko, I L

    1989-01-01

    The mycelium of Streptomyces fradiae was fractionated by differential centrifugation in a sucrose density gradient (SDG) using various samples of the inoculation material and aliquots of the cultural broth taken in the course of tylosin production. The mode of mycelium distribution in SDG made it possible to select the most active inoculation material. The mycelium was redistributed from sucrose layers with a high density to those with a lower density in the course of fermentation. The fractions differed in the antibiotic activity but none of them had an activity higher than in the control centrifuged in 30% sucrose and washed off just like the fractions. Therefore, mycelium fractionation in SDG would not elevate its antibiotic activity. The paper presents the cytological characteristics of different fractions changing in the course of fermentation.

  5. HbNIN2, a cytosolic alkaline/neutral-invertase, is responsible for sucrose catabolism in rubber-producing laticifers of Hevea brasiliensis (para rubber tree).

    PubMed

    Liu, Shujin; Lan, Jixian; Zhou, Binhui; Qin, Yunxia; Zhou, Yihua; Xiao, Xiaohu; Yang, Jianghua; Gou, Jiqing; Qi, Jiyan; Huang, Yacheng; Tang, Chaorong

    2015-04-01

    In Hevea brasiliensis, an alkaline/neutral invertase (A/N-Inv) is responsible for sucrose catabolism in latex (essentially the cytoplasm of rubber-producing laticifers, the source of natural rubber) and implicated in rubber yield. However, neither the gene encoding this enzyme nor its molecular and biochemical properties have been well documented. Three Hevea A/N-Inv genes, namely HbNIN1, 2 and 3, were first cloned and characterized in planta and in Escherichia coli. Cellular localizations of HbNIN2 mRNA and protein were probed. From latex, active A/N-Inv proteins were purified, identified, and explored for enzymatic properties. HbNIN2 was identified as the major A/N-Inv gene functioning in latex based on its functionality in E. coli, its latex-predominant expression, the conspicuous localization of its mRNA and protein in the laticifers, and its expressional correlation with rubber yield. An active A/N-Inv protein was partially purified from latex, and determined as HbNIN2. The enhancement of HbNIN2 enzymatic activity by pyridoxal is peculiar to A/N-Invs in other plants. We conclude that HbNIN2, a cytosolic A/N-Inv, is responsible for sucrose catabolism in rubber laticifers. The results contribute to the studies of sucrose catabolism in plants as a whole and natural rubber synthesis in particular.

  6. Density dependent mechanical properties and structures of a freeze dried biopharmaceutical excipient--sucrose.

    PubMed

    Devi, Sharmila; Williams, Daryl R

    2014-10-01

    Knowledge of the mechanical behaviour of freeze dried biopharmaceutical products is essential for designing of products with physical robustness that will not to crack, crumble or collapse during processing or transportation. The compressive mechanical deformation behaviour for freeze-dried sucrose cakes has been experimentally studied from a relative density (ρf/ρs) of 0.01-0.30 using a novel in-vial indentation test. Cakes exhibited more open like structures at lower densities and more closed structures at higher densities with some faces being present at all densities, as confirmed by SEM. The reduced elastic modulus Ef/Es=0.0044(ρf/ρs)(1) for all cake densities, indicating that face stretching was the dominant deformation mode assuming Gibson and Ashby's closed cell model. This linear scaling for the reduced elastic modulus is in line with various theoretical treatments based on tetrakaidecahedral cells and other experimental studies. Consistently, the wall thickness to cell diameter ratio scaled ρf/ρs with a power constant of 1.05. The maximum crushing stress was given by σmax=3800(ρf/ρs)(1.48) which agrees with a strut bending failure stress, assuming Gibson and Ashby's open cell model. Overall, the freeze dried cakes behaved as neither classic closed cell nor open cell materials, with their compressive elastic moduli reflecting a closed cell elastic response whilst their failure stresses reflecting an open cell failure mode. It was concluded that the mechanical response of freeze dried cellular materials depends upon their complex cellular structures and morphologies, and they cannot be rationalised using simple limiting case models of open or closed cell solids.

  7. Liquid density analysis of sucrose and alcoholic beverages using polyimide guided Love-mode acoustic wave sensors

    NASA Astrophysics Data System (ADS)

    Turton, Andrew; Bhattacharyya, Debabrata; Wood, David

    2006-02-01

    A liquid density sensor using Love-mode acoustic waves has been developed which is suitable for use in the food and drinks industries. The sensor has an open flat surface allowing immersion into a sample and simple cleaning. A polyimide waveguide layer allows cheap and simple fabrication combined with a robust chemically resistant surface. The low shear modulus of polyimide allows thin guiding layers giving a high sensitivity. A dual structure with a smooth reference device exhibiting viscous coupling with the wave, and a patterned sense area to trap the liquid causing mass loading, allows discrimination of the liquid density from the square root of the density-viscosity product (ρη)0.5. Frequency shift and insertion loss change were proportional to (ρη)0.5 with a non-linear response due to the non-Newtonian nature of viscous liquids at high frequencies. Measurements were made with sucrose solutions up to 50% and different alcoholic drinks. A maximum sensitivity of 0.13 µg cm-3 Hz-1 was achieved, with a linear frequency response to density. This is the highest liquid density sensitivity obtained for acoustic mode sensors to the best of our knowledge.

  8. Supermolecule density functional calculations suggest a key role for solvent in alkaline hydrolysis of p-nitrophenyl phosphate.

    PubMed

    Zhang, Lidong; Xie, Daiqian; Xu, Dingguo; Guo, Hua

    2007-04-28

    Supermolecule density functional theory calculations show that solvent is responsible for the concerted transition state in alkaline hydrolysis of p-nitrophenyl phosphate suggested by heavy atom kinetic isotope effects.

  9. A mathematical model of the maximum power density attainable in an alkaline hydrogen/oxygen fuel cell

    NASA Technical Reports Server (NTRS)

    Kimble, Michael C.; White, Ralph E.

    1991-01-01

    A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict the polarization behavior under various power loads. The major limitations to achieving high power densities are indicated and methods to increase the maximum attainable power density are suggested. The alkaline fuel cell model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions based on porous electrode theory applied to three phases. Fundamental equations of chemical engineering that describe conservation of mass and charge, species transport, and kinetic phenomena are used to develop the model by treating all phases as a homogeneous continuum.

  10. Cryopreservation of rabbit semen using non-permeable cryoprotectants: effectiveness of different concentrations of low-density lipoproteins (LDL) from egg yolk versus egg yolk or sucrose.

    PubMed

    Iaffaldano, N; Di Iorio, M; Rosato, M P; Manchisi, A

    2014-12-30

    This study was designed to identify the most effective non-permeable cryoprotectant (CPA) for the cryopreservation of rabbit semen by comparing the effects of different concentrations of low-density lipoproteins (LDL) on post-thaw sperm quality with those of whole egg yolk or sucrose. In a second experiment, the performance of the non-permeable CPAs identified as most effective was assessed in vivo by determining reproductive performances. Pooled semen samples were diluted to a ratio of 1:1 (v:v) in freezing extender (Tris-citrate-glucose and 16% dimethylsulfoxide as permeable CPA) containing as non-permeable CPAs 6, 8, 10 or 15% LDL from egg yolk, 0.1M sucrose, or 15% egg yolk. The semen was loaded in 0.25mL straws and frozen in liquid nitrogen vapor. After thawing, we determined sperm motility, viability, osmotic resistance, and acrosome and DNA integrity. Our results clearly revealed a significant effect of LDL concentration on semen quality. Also, at an optimal concentration of 10%, motility and acrosome integrity were improved over the values recorded for egg yolk (P<0.05). Based on the in vitro data, 3 groups of does (n=30 each) were inseminated with fresh semen or semen frozen using sucrose or 10% LDL. Sucrose led to a significantly higher conception rate than LDL and reproductive performance was similar to that observed for fresh semen. Our findings indicate the markedly better performance of sucrose in vivo as a non-permeable CPA for the cryopreservation of rabbit semen.

  11. High power density alkaline fuel cell technology for MMW space burst power

    NASA Astrophysics Data System (ADS)

    Preston, J. Lawrence, Jr.; Trocciola, John C.; Wertheim, Ronald J.

    The use of advanced alkaline regenerative fuel cell energy storage systems to provide 10's to 100's of MWe of sprint (burst) power for 100's of seconds per orbit of SDI weapons platform was studied. Recharge power is supplied by a multimegawatt space based nuclear power system. Regenerative fuel cell energy storage systems offer the potential for significant platform mass reduction by reducing the size and mass of the nuclear power source required. This is because the reactor can be sized for the smaller average power level for the energy storage system, rather than the sprint power level. The regenerative fuel cell is a particularly attractive energy storage device because the fuel cell is essentially a static power conversion device, which results in excellent platform stability for weapon pointing and tracking. Based upon the detailed point design and conceptual layout, the alkaline regenerative fuel cell energy storage system is an attractive choice for integration with a nuclear thermionic system for providing multimegawatt burst power and multi orbit capability.

  12. Density changes of bismuth and alkaline metals at the transition to the liquid state

    NASA Astrophysics Data System (ADS)

    Stankus, S. V.; Abdullaev, R. N.; Khairulin, R. A.

    2016-11-01

    Relative density changes δρ f of sodium, potassium, rubidium, and bismuth on melting-crystallization were studied using monochromatic gamma-ray attenuation technique. The measurement error of density changes was 0.1-0.12 %. A comparison of the obtained results with the known literature data was carried out, and the values of δρ f recommended as reference data were determined.

  13. Sucrose metabolism in lima bean seeds

    SciTech Connect

    Xu, Dianpeng; Sung, Shijean, S.; Black, C.C. )

    1989-04-01

    Developing and germinating lima bean (Phaseolus lunatus var Cangreen) seeds were used for testing the sucrose synthase pathway, to examine the competition for uridine diphosphate (UDP) and pyrophosphate (PPi), and to identify adaptive and maintenance-type enzymes in glycolysis and gluconeogenesis. In developing seeds, sucrose breakdown was dominated by the sucrose synthase pathway; but in the seedling embryos, both the sucrose synthase pathway and acid invertase were active. UDPase activity was low and seemingly insufficient to compete for UDP during sucrose metabolism in seed development or germination. In contrast, both an acid and alkaline pyrophosphatase were active in seed development and germination. The set of adaptive enzymes identified in developing seeds were sucrose synthase, PPi-dependent phosphofructokinase, plus acid and alkaline pyrophosphatase; and, the adaptive enzymes identified in germinating seeds included the same set of enzymes plus acid invertase. The set of maintenance enzymes identified during development, in the dry seed, and during germination were UDP-glucopyrophosphorylase, neutral invertase, ATP and UTP-dependent fructokinase, glucokinase, phosphoglucomutase, ATP and UTP-dependent phosphofructokinase and sucrose-P synthase.

  14. A Density Functional Theory Study of Codoping Characteristics of Sulfur with Alkaline Earth in Delafossite CuAlO2

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Jun; Qin, Han; Liu, Zheng-Tang

    2016-04-01

    The structural, electronic properties and formation energies of sulfur and alkaline earth codoped delafossite CuAlO2 have been investigated using the first-principles density functional theory calculations. Our results reveal that the volume of codoping systems increases with the increasing atomic radius of metal atoms. The formation energies under different growth conditions have been calculated, showing that the codoping systems are formed easily under O-rich growth conditions. Electronic band structures and density of states have been obtained. The decreased bandgaps, enhanced covalence and appearance of electron acceptors after codoping are all good for p-type conductivity. Supported by the National Natural Science Foundation of China under Grant Nos. 11347199, 51402244, and 11547311, the Specialized Research Fund for Doctoral Program of Higher Education of China under Grant No. 20130184120028, the Fundamental Research Fund for the Central Universities, China under Grant Nos. 2682014CX084, 2682014ZT30, and 2682014ZT31, and the fund of the State Key Laboratory of Solidification Processing in NWPU under Grant No. SKLSP201511

  15. Iron Sucrose Injection

    MedlinePlus

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...

  16. Sucrose and Related Oligosaccharides

    NASA Astrophysics Data System (ADS)

    Eggleston, Gillian

    Sucrose (α-D-glucopyranosyl-(1↔2)-β-D-fructofuranoside) is the most common low-molecular-weight sugar found in the plant kingdom. It is ubiquitously known as common table sugar and primarily produced industrially from sugarcane (Saccharum officinarum) and sugar beet (Beta vulgaris); the basics of the industrial manufacture of sucrose are outlined in this chapter. Commercial sucrose has a very high purity (> 99.9%) making it one of the purest organic substances produced on an industrial scale. Value-addition to sucrose via chemical and biotechnological reactions is becoming more important for the diversification of the sugar industry to maintain the industries' competitiveness in a world increasingly turning to a bio-based economy. The basis for the chemical reactivity of sucrose is the eight hydroxyl groups present on the molecule, although, sucrose chemical reactivity is regarded as difficult. Increasing use of enzymatic biotechnological techniques to derivatize sucrose is expected, to add special functionalities to sucrose products like biodegradability, biocompatibility, and non-toxicity. Analysis of sucrose by colorimetric, enzymatic, oxidation-reduction and chromatography methods are discussed. Oligosaccharides related to sucrose are outlined in detail and include sucrose-based plant, honey and in vitro oligosaccharides.

  17. The effects on DNA migration of altering parameters in the comet assay protocol such as agarose density, electrophoresis conditions and durations of the enzyme or the alkaline treatments.

    PubMed

    Ersson, Clara; Möller, Lennart

    2011-11-01

    The single cell gel electrophoresis (comet assay) is a popular method for measuring DNA migration as an estimate of DNA damage. No standardised comet assay protocol exists, which make comparisons between studies complicated. In a previous inter-laboratory validation study of the comet assay, we identified important parameters in the protocol that might affect DNA migration. The aim of this study was to assess how different comet assay protocols affect DNA migration. The results in this study suggest that (i) there is a significant linear dose-response relationship between the agarose gel's density and DNA migration and that damaged cells are more sensitive to the agarose gel's density; (ii) incubation with formamidopyrimidine DNA glycosylase for 10 min is inadequate, whereas 30 min is sufficient; (iii) the typically used 20 min of alkaline treatment might be to short when analysing samples that contain particular alkali-labile sites (ALS) and (iv) the duration of electrophoresis as well as the strength of the electric field applied affects the DNA migration. By using protocol-specific calibration curves, it is possible to reduce the variation in DNA migration caused by differences in comet assay protocols. This does, however, not completely remove the impact of the durations of alkaline treatment and electrophoresis when analysing cells containing ALS that are relatively resistant to high alkaline treatment.

  18. Sucrose signaling in plants

    PubMed Central

    Tognetti, Jorge A.; Pontis, Horacio G.; Martínez-Noël, Giselle M.A.

    2013-01-01

    The role of sucrose as a signaling molecule in plants was originally proposed several decades ago. However, recognition of sucrose as a true signal has been largely debated and only recently this role has been fully accepted. The best-studied cases of sucrose signaling involve metabolic processes, such as the induction of fructan or anthocyanin synthesis, but a large volume of scattered information suggests that sucrose signals may control a vast array of developmental processes along the whole life cycle of the plant. Also, wide gaps exist in our current understanding of the intracellular steps that mediate sucrose action. Sucrose concentration in plant tissues tends to be directly related to light intensity, and inversely related to temperature, and accordingly, exogenous sucrose supply often mimics the effect of high light and cold. However, many exceptions to this rule seem to occur due to interactions with other signaling pathways. In conclusion, the sucrose role as a signal molecule in plants is starting to be unveiled and much research is still needed to have a complete map of its significance in plant function. PMID:23333971

  19. Analysis of sucrose acetates in a crude 6-O-acetyl sucrose product by on-line hydrolysis-high-performance liquid chromatography with pulsed amperometric detection.

    PubMed

    Yan, Wenwu; Wang, Nani; Zhang, Peimin; Zhang, Jiajie; Wu, Shuchao; Zhu, Yan

    2016-06-03

    A standard-free and sensitive method was developed for analysis of sucrose acetates in a crude 6-O-acetyl sucrose (S-6-a) product by on-line hydrolysis-high-performance liquid chromatography with pulsed amperometric detection (PAD). Sucrose, three regio-isomers of acetyl sucrose and five regio-isomers of diacetyl sucrose were separated on a C18 column using 3% (v/v) acetonitrile in water as eluent within 25min. After purification with LC followed by semi-preparative HPLC, their chemical structures were identified by 1D, 2D NMR and LC-MS. Moreover, quantification of those regio-isomers was achieved by on-line alkaline hydrolysis to liberate sucrose using a post-column delivery system, and then detected by PAD for indirect estimation of the sucrose acetate content. Under optimal conditions, the linear ranges were from 0.03 to 150μmolL(-1) for sucrose corresponding to sucrose acetates with coefficient of determination as 0.9997 and detection limit as 0.01μmolL(-1) (S/N=3). Good repeatability was obtained (RSD<3%, n=6). Furthermore, this method has been successfully applied to the analysis of sucrose and sucrose acetates in a crude S-6-a product during synthesis, purification and structure elucidation studies. The recoveries were from 94.89% to 102.31% for sucrose and sucrose acetates.

  20. Sucrose and behavioral problems.

    PubMed

    Benton, David

    2008-05-01

    Various mechanisms by which sucrose could influence behavior are reviewed. Firstly there is food intolerance. There are dozens of foods to which an adverse reaction has been demonstrated, although a reaction to sucrose is less frequent than many other foods. A second possible mechanism is hypoglycemia. There is evidence that a tendency to develop low blood glucose levels, but higher than those that can be described clinically as hypoglycemic, is associated with irritability and violence. However, sucrose is not the predominant cause of swings in blood glucose levels. Thirdly, the role of sucrose intake on micro-nutrient status has been considered as studies have found that micro-nutrient supplementation decreased anti-social behavior. Micro-nutrient intake is more closely associated with the total energy rather than sucrose intake; typically the amount of sucrose in the diet does not lead to micro-nutrient deficiency. In fact meta-analysis of well designed studies that have examined the impact of sucrose on the behavior of children produced no evidence that it has an adverse influence.

  1. Effects of Soil Salinity on Sucrose Metabolism in Cotton Fiber

    PubMed Central

    Liu, Jingran; Luo, Junyu; Zhao, Xinhua; Dong, Helin; Ma, Yan; Sui, Ning; Zhou, Zhiguo; Meng, Yali

    2016-01-01

    Cotton (Gosspium hirsutum L.) is classified as a salt tolerant crop. However, its yield and fiber quality are negatively affected by soil salinity. Studies on the enzymatic differences in sucrose metabolism under different soil salinity levels are lacking. Therefore, field experiments, using two cotton cultivars, CCRI-79 (salt-tolerant) and Simian 3 (salt-sensitive), were conducted in 2013 and 2014 at three different salinity levels (1.15 dS m-1 [low soil salinity], 6.00 dS m-1 [medium soil salinity], and 11.46 dS m-1 [high soil salinity]). The objective was to elucidate the effects of soil salinity on sucrose content and the activity of key enzymes that are related to sucrose metabolism in cotton fiber. Results showed that as the soil salinity increased, cellulose content, sucrose content, and sucrose transformation rate declined; the decreases in cellulose content and sucrose transformation rate caused by the increase in soil salinity were more in Simian 3 than those in CCRI-79. With increase in soil salinity, activities of sucrose metabolism enzymes sucrose phophate synthase (SPS), acidic invertase, and alkaline invertase were decreased, whereas sucrose synthase (SuSy) activity increased. However, the changes displayed in the SuSy and SPS activities in response to increase in soil salinity were different and the differences were large between the two cotton cultivars. These results illustrated that suppressed cellulose synthesis and sucrose metabolism under high soil salinity were mainly due to the change in SPS, SuSy, and invertase activities, and the difference in cellulose synthesis and sucrose metabolism in fiber for the two cotton cultivars in response to soil salinity was determined mainly by both SuSy and SPS activities. PMID:27227773

  2. Sucrose Synthase: Expanding Protein Function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose synthase (SUS: EC 2.4.1.13), a key enzyme in plant sucrose catabolism, is uniquely able to mobilize sucrose into multiple pathways involved in metabolic, structural, and storage functions. Our research indicates that the biological function of SUS may extend beyond its catalytic activity. Th...

  3. Sugar (sucrose) holograms

    NASA Astrophysics Data System (ADS)

    Ponce-Lee, E. L.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2004-06-01

    Computer holograms made with sugar crystals are reported. This material is well known as a good sweetener; the sugar from sugar cane or sugar beet (sucrose). These sweetener can be applied as honey "water and diluted sugar" easily on any substrate such as plastics or glasses without critical conditions for developed process. This step corresponds only to the cured sucrose as a photopolymer process. The maximum absorption spectra is localized at UV region λ=240 nm. We record with lithographic techniques some gratings, showing a good diffraction efficiency around 45%. This material has good resolution to make diffraction gratings. These properties are attractive because they open the possibility to make phase holograms on candies. Mainly the phase modulation is by refraction index.

  4. Oligosaccharides Derived from Sucrose

    NASA Astrophysics Data System (ADS)

    Monsan, Pierre F.; Ouarné, Francois

    Sucrose is a non-reducing disaccharide, consisting of an α-D-glucopyranosyl residue and a β-D-fructofuranosyl residue linked covalently by their respective anomeric carbons (α-D-glucopyranosyl-1,2-β-D-fructofuranoside). It is not just a simple disaccharide, among others: in fact, the energy of its glycosidic bond is higher than that of a usual glycosidic bond. It is equal to 27.6 kJ/mol, which is similar to the energy of a nucleotide-sugar bond as in UDP-glucose or ADP-glucose. This means that sucrose is a protected and activated form of D-glucose (as well as of D-fructose), which plays a key role in the metabolism of plants, for a wide variety of synthesis reactions.

  5. CO2 capture properties of alkaline earth metal oxides and hydroxides: A combined density functional theory and lattice phonon dynamics study

    NASA Astrophysics Data System (ADS)

    Duan, Yuhua; Sorescu, Dan C.

    2010-08-01

    By combining density functional theory and lattice phonon dynamics, the thermodynamic properties of CO2 absorption/desorption reactions with alkaline earth metal oxides MO and hydroxides M(OH)2 (where M=Be,Mg,Ca,Sr,Ba) are analyzed. The heats of reaction and the chemical potential changes of these solids upon CO2 capture reactions have been calculated and used to evaluate the energy costs. Relative to CaO, a widely used system in practical applications, MgO and Mg(OH)2 systems were found to be better candidates for CO2 sorbent applications due to their lower operating temperatures (600-700 K). In the presence of H2O, MgCO3 can be regenerated into Mg(OH)2 at low temperatures or into MgO at high temperatures. This transition temperature depends not only on the CO2 pressure but also on the H2O pressure. Based on our calculated results and by comparing with available experimental data, we propose a general computational search methodology which can be used as a general scheme for screening a large number of solids for use as CO2 sorbents.

  6. Extraction of sucrose from molasses

    SciTech Connect

    Landis, A.M.

    1982-01-26

    Sucrose is extracted from molasses by passing an aqueous molasses solution over an adsorbent, e.g., calcined Al/sub 2/O/sub 3/-supported pyrolyzed C/sub 6/H/sub 6/. Thus, 10 mL molasses (approximately 46% solids) was run through a column containing 70 cubic centimetres above adsorbent with sucrose retention volume 21.4 and selectivity for sucrose - betaine 23.8.

  7. Characterization of Surface and Bulk Nitrates of γ-Al2O3-Supported Alkaline Earth Oxides using Density Functional Theory

    SciTech Connect

    Mei, Donghai; Ge, Qingfeng; Kwak, Ja Hun; Kim, Do Heui; Verrier, Christelle M.; Szanyi, Janos; Peden, Charles HF

    2009-05-14

    “Surface" and "bulk" nitrates formed on a series of alkaline earth oxides (AEOs), AE(NO3)2, were investigated using first-principles density functional theory calculations. The formation of these surface and bulk nitrates was modeled by the adsorption of NO2+NO3 pairs on gamma-Al2O3-supported monomeric AEOs (MgO, CaO, SrO, and BaO) and on the extended AEO(001) surfaces, respectively. The calculated vibrational frequencies of the surface and bulk nitrates based on our proposed models are in good agreement with experimental measurements of AEO/gamma-Al2O3 materials after prolonged NO2 exposure. This indicates that experimentally observed "surface" nitrates are most likely formed with isolated two dimensional (including monomeric) AEO clusters on the gamma-Al2O3 substrate, while the "bulk" nitrates are formed on exposed (including (001)) surfaces (and likely in the bulk as well) of large three dimensional AEO particles supported on the gamma-Al2O3 substrate. Also in line with the experiments, our calculations show that the low and high frequency components of the vibrations for both surface and bulk nitrates are systematically red shifted with the increasing basicity and cationic size of the AEOs. The adsorption strengths of NO2+NO3 pairs are nearly the same for the series of alumina-supported monomeric AEOs, while the adsorption strengths of NO2+NO3 pairs on the AEO surfaces increase in the order of MgO < CaO < SrO ~ BaO. Compared to the NO2+NO3 pair that only interacts with monomeric AEOs, the stability of NO2+NO3 pairs that interact with both the monomeric AEO and the gamma-Al2O3 substrate is enhanced by about 0.5 eV. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  8. Switching the mode of sucrose utilization by Saccharomyces cerevisiae

    PubMed Central

    Badotti, Fernanda; Dário, Marcelo G; Alves, Sergio L; Cordioli, Maria Luiza A; Miletti, Luiz C; de Araujo, Pedro S; Stambuk, Boris U

    2008-01-01

    Background Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomass-directed processes. It results from elevated sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high (e.g. 20 g/L) initial sugar concentrations. In this study, a S. cerevisiae strain lacking invertase activity was engineered to transport sucrose into the cells through a low-affinity and low-capacity sucrose-H+ symport activity, and the growth kinetics and biomass yields on sucrose analyzed using simple batch cultures. Results We have deleted from the genome of a S. cerevisiae strain lacking invertase the high-affinity sucrose-H+ symporter encoded by the AGT1 gene. This strain could still grow efficiently on sucrose due to a low-affinity and low-capacity sucrose-H+ symport activity mediated by the MALx1 maltose permeases, and its further intracellular hydrolysis by cytoplasmic maltases. Although sucrose consumption by this engineered yeast strain was slower than with the parental yeast strain, the cells grew efficiently on sucrose due to an increased respiration of the carbon source. Consequently, this engineered yeast strain produced less ethanol and 1.5 to 2 times more biomass when cultivated in simple batch mode using 20 g/L sucrose as the carbon source. Conclusion Higher cell densities during batch cultures on 20 g/L sucrose were achieved by using a S. cerevisiae strain engineered in the sucrose uptake system. Such result was accomplished by effectively reducing sucrose

  9. Vacuolar Acid Hydrolysis as a Physiological Mechanism for Sucrose Breakdown 1

    PubMed Central

    Echeverria, Ed; Burns, Jacqueline K.

    1989-01-01

    Sucrose breakdown in mature acidic `Persian' limes (Citrus aurantifolia [Christm.] Swing.) occurred at a rate of 30.6 picomoles per milliliter per day during 9 weeks storage at 15°C. Neither enzyme of sucrose catabolism (sucrose synthase or acid/alkaline invertase) was present in extracts of mature storage tissue. The average vacuolar pH, estimated by direct measurement of sap from isolated vacuoles and by the methylamine method, was about 2.0 to 2.2. In vitro acid hydrolysis of sucrose at physiological concentrations in a buffered solution (pH 2.2) occurred at identical rates as in matured limes. The results indicate that sucrose breakdown in stored mature acidic limes occurs by acid hydrolysis. PMID:16666803

  10. Purification, characterization and physiological role of sucrose synthase in the pea seed coat (Pisum sativum L.).

    PubMed

    Déjardin, A; Rochat, C; Maugenest, S; Boutin, J P

    1997-01-01

    The seed coat is a maternal organ which surrounds the embryo and is involved in the control of its nutrition. This study with pea (Pisum sativum L.) was conducted to understand more fully the sucrose/starch interconversions occurring in the seed coat. The concentrations of soluble sugars, the starch content, and the activities of the sucrose-metabolizing enzymes, sucrose synthase (Sus; EC 2.4.1.13), alkaline and soluble acid invertase (EC 3.2.1.26) and sucrose-phosphate synthase (SPS; EC 2.4.1.14) were compared at four developmental stages during seed filling. Among the four enzymes, only Sus activity was very high and strongly correlated with the starch concentration in the seed coat. Sucrose synthase catalyses the cleavage of sucrose in the presence of UDP into UDP-glucose and fructose. Sucrose synthase was purified from pea seed coats in a three-step protocol, consisting of diethylaminoethyl-Sephacel chromatography, gel filtration and affinity chromatography. The enzyme was characterized at the biochemical and molecular levels. Sucrose synthase exhibits biochemical properties which allow it to function in the direction of both sucrose cleavage and synthesis. The mass-action ratio of its four substrate was close to the theoretical equilibrium constant at the four developmental stages we studied. A labelling experiment on seed coats has shown that Sus activity is reversible in vivo and can produce 37% of neo-synthesized sucrose in the seed coat cells (minimum value). It is concluded that Sus could play a central role in the control of sucrose concentration in the seed coat cells in response to the demand for sucrose in the embryo during the development of the seed.

  11. Alkaline quinone flow battery.

    PubMed

    Lin, Kaixiang; Chen, Qing; Gerhardt, Michael R; Tong, Liuchuan; Kim, Sang Bok; Eisenach, Louise; Valle, Alvaro W; Hardee, David; Gordon, Roy G; Aziz, Michael J; Marshak, Michael P

    2015-09-25

    Storage of photovoltaic and wind electricity in batteries could solve the mismatch problem between the intermittent supply of these renewable resources and variable demand. Flow batteries permit more economical long-duration discharge than solid-electrode batteries by using liquid electrolytes stored outside of the battery. We report an alkaline flow battery based on redox-active organic molecules that are composed entirely of Earth-abundant elements and are nontoxic, nonflammable, and safe for use in residential and commercial environments. The battery operates efficiently with high power density near room temperature. These results demonstrate the stability and performance of redox-active organic molecules in alkaline flow batteries, potentially enabling cost-effective stationary storage of renewable energy.

  12. Advanced alkaline water electrolysis

    NASA Astrophysics Data System (ADS)

    Wakabayashi, N.; Torikai, E.; Kawami, Y.; Takenaka, H.

    Results are presented of experimental studies of possible separators and electrodes for use in advanced, high-temperature, high-pressure alkaline water electrolyzers. Material evaluations in alkaline water electrolyzers at temperatures from 100 to 120 C have shown a new type polytetrafluoroethylene membrane impregnated with potassium titanate to be the most promising when the separator is prepared by the hydrothermal treatment of a porous PFTE membrane impregnated with hydrated titanium oxide. Measurements of cell voltages in 30% KOH at current densities from 5 to 100 A/sq dm at temperatures up to 120 C with nickel electrodes of various structures have shown the foamed nickel electrode, with an average pore size of 1-1.5 mm, to have the best performance. When the foamed nickel is coated by fine powdered nickel, carbonyl nickel or Raney nickel to increase electrode surface areas, even lower cell voltages were found, indicating better performance.

  13. Sucrose diffusion in aqueous solution

    PubMed Central

    Murray, Benjamin J.

    2016-01-01

    The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes–Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle. PMID:27364512

  14. Effect of sucrose on physical properties of spray-dried whole milk powder.

    PubMed

    Ma, U V Lay; Ziegler, G R; Floros, J D

    2008-11-01

    Spray-dried whole milk powders were prepared from whole condensed milk with various sucrose concentrations (0%, 2.5%, 5%, 7.5%, and 10% w/w), and their glass transition temperature and some physical properties of importance in chocolate manufacture were evaluated. In milk powder samples, the glass transition temperature and free-fat content decreased in a nonlinear manner with sucrose addition. Moreover, increasing sucrose concentration reduced the formation of dents on the particle surface. Addition of sucrose in whole condensed milk increased linearly the apparent particle density and in a nonlinear manner the particle size of spray-dried milk powders. The particle size volume distribution of milk powders with the highest sucrose concentration differed from the log-normal distribution of the other samples due to the formation of large agglomerates. Neither vacuole volume, nor the amorphous state of milk powders was affected by sucrose addition.

  15. In Silico Alkaline Hydrolysis of Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine: Density Functional Theory Investigation.

    PubMed

    Sviatenko, Liudmyla K; Gorb, Leonid; Hill, Frances C; Leszczynska, Danuta; Shukla, Manoj K; Okovytyy, Sergiy I; Hovorun, Dmytro; Leszczynski, Jerzy

    2016-09-20

    HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine), an energetic material used in military applications, may be released to the environment during manufacturing, transportation, storage, training, and disposal. A detailed investigation of a possible mechanism of alkaline hydrolysis, as one of the most promising methods for HMX remediation, was performed by computational study at PCM(Pauling)/M06-2X/6-311++G(d,p) level. Obtained results suggest that HMX hydrolysis at pH 10 represents a highly exothermic multistep process involving initial deprotonation and nitrite elimination, hydroxide attachment accompanied by cycle cleavage, and further decomposition of cycle-opened intermediate to the products caused by a series of C-N bond ruptures, hydroxide attachments, and proton transfers. Computationally predicted products of HMX hydrolysis such as nitrite, 4-nitro-2,4-diazabutanal, formaldehyde, nitrous oxide, formate, and ammonia correspond to experimentally observed species. Based on computed reaction pathways for HMX decomposition by alkaline hydrolysis, the kinetics of the entire process was modeled. Very low efficiency of this reaction at pH 10 was observed. Computations predict significant increases (orders of magnitude) of the hydrolysis rate for hydrolysis reactions undertaken at pH 11, 12, and 13.

  16. Oligosaccharides from Sucrose via Glycansucrases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glycansucrases are a class of microbial enzymes that polymerize either the fructosyl or the glucosyl moiety of sucrose to give beta-D-fructans or alpha-D-glucans. They are also capable of transferring fructosyl or glucosyl units to acceptor molecules to yield oligosaccharides. Although the glycosy...

  17. Featured Molecules: Sucrose and Vanillin

    NASA Astrophysics Data System (ADS)

    Coleman, William F.; Wildman, Randall J.

    2003-04-01

    The WebWare molecules of the month for April relate to the sense of taste. Apple Fool, the JCE Classroom Activity, mentions sucrose and vanillin and their use as flavorings. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

  18. High-level expression of improved thermo-stable alkaline xylanase variant in Pichia Pastoris through codon optimization, multiple gene insertion and high-density fermentation

    PubMed Central

    Lu, Yihong; Fang, Cheng; Wang, Qinhong; Zhou, Yuling; Zhang, Guimin; Ma, Yanhe

    2016-01-01

    In paper industry, xylanases are used to increase the pulp properties in bleaching process as its eco-friendly nature. The xylanases activity is hindered by high temperature and alkaline conditions with high enzyme production cost in the paper industry. Here, XynHB, an alkaline stable xylanase from Bacillus pumilus HBP8 was mutated at N188A to XynHBN188A. Expressed mutant in E. coli showed 1.5-fold higher xylanase activity than XynHB at 60 °C. The mutant expressed in Pichia pastoris was glycosylated, remained stable for 30 min at 60 °C. XynHBN188A optimized based on codon usage bias for P. pastoris (xynHBN188As) showed an increase of 39.5% enzyme activity. The strain Y16 forming the largest hydrolysis halo in the xylan plate was used in shake flask experiments produced an enzyme activity of 6,403 U/ml. The Y16 strain had 9 copies of the recombinant xynHBN188As gene in the genome revealed by qPCR. The enzymatic activity increased to 48,241 U/ml in a 5 L fermentor. Supplement of 15 U/g xylanase enhanced the brightness of paper products by 2% in bleaching experiment, and thereby improved the tensile strength and burst factor by 13% and 6.5%, respectively. XynHBN188As has a great potential in paper industries. PMID:27897254

  19. High-level expression of improved thermo-stable alkaline xylanase variant in Pichia Pastoris through codon optimization, multiple gene insertion and high-density fermentation.

    PubMed

    Lu, Yihong; Fang, Cheng; Wang, Qinhong; Zhou, Yuling; Zhang, Guimin; Ma, Yanhe

    2016-11-29

    In paper industry, xylanases are used to increase the pulp properties in bleaching process as its eco-friendly nature. The xylanases activity is hindered by high temperature and alkaline conditions with high enzyme production cost in the paper industry. Here, XynHB, an alkaline stable xylanase from Bacillus pumilus HBP8 was mutated at N188A to XynHBN188A. Expressed mutant in E. coli showed 1.5-fold higher xylanase activity than XynHB at 60 °C. The mutant expressed in Pichia pastoris was glycosylated, remained stable for 30 min at 60 °C. XynHBN188A optimized based on codon usage bias for P. pastoris (xynHBN188As) showed an increase of 39.5% enzyme activity. The strain Y16 forming the largest hydrolysis halo in the xylan plate was used in shake flask experiments produced an enzyme activity of 6,403 U/ml. The Y16 strain had 9 copies of the recombinant xynHBN188As gene in the genome revealed by qPCR. The enzymatic activity increased to 48,241 U/ml in a 5 L fermentor. Supplement of 15 U/g xylanase enhanced the brightness of paper products by 2% in bleaching experiment, and thereby improved the tensile strength and burst factor by 13% and 6.5%, respectively. XynHBN188As has a great potential in paper industries.

  20. Episodic sucrose intake during food restriction increases synaptic abundance of AMPA receptors in nucleus accumbens and augments intake of sucrose following restoration of ad libitum feeding.

    PubMed

    Peng, X-X; Lister, A; Rabinowitsch, A; Kolaric, R; Cabeza de Vaca, S; Ziff, E B; Carr, K D

    2015-06-04

    Weight-loss dieting often leads to loss of control, rebound weight gain, and is a risk factor for binge pathology. Based on findings that food restriction (FR) upregulates sucrose-induced trafficking of glutamatergic AMPA receptors to the nucleus accumbens (NAc) postsynaptic density (PSD), this study was an initial test of the hypothesis that episodic "breakthrough" intake of forbidden food during dieting interacts with upregulated mechanisms of synaptic plasticity to increase reward-driven feeding. Ad libitum (AL) fed and FR subjects consumed a limited amount of 10% sucrose, or had access to water, every other day for 10 occasions. Beginning three weeks after return of FR rats to AL feeding, when 24-h chow intake and rate of body weight gain had normalized, subjects with a history of sucrose intake during FR consumed more sucrose during a four week intermittent access protocol than the two AL groups and the group that had access to water during FR. In an experiment that substituted noncontingent administration of d-amphetamine for sucrose, FR subjects displayed an enhanced locomotor response during active FR but a blunted response, relative to AL subjects, during recovery from FR. This result suggests that the enduring increase in sucrose consumption is unlikely to be explained by residual enhancing effects of FR on dopamine signaling. In a biochemical experiment which paralleled the sucrose behavioral experiment, rats with a history of sucrose intake during FR displayed increased abundance of pSer845-GluA1, GluA2, and GluA3 in the NAc PSD relative to rats with a history of FR without sucrose access and rats that had been AL throughout, whether they had a history of episodic sucrose intake or not. A history of FR, with or without a history of sucrose intake, was associated with increased abundance of GluA1. A terminal 15-min bout of sucrose intake produced a further increase in pSer845-GluA1 and GluA2 in subjects with a history of sucrose intake during FR

  1. 21 CFR 172.869 - Sucrose oligoesters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... mixtures of sucrose fatty acid esters with an average degree of esterification ranging from four to seven. It is produced by interesterification of sucrose with methyl esters of fatty acids derived from... preparation of sucrose oligoesters are dimethyl sulfoxide, isobutyl alcohol, and those solvents...

  2. 21 CFR 172.869 - Sucrose oligoesters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... mixtures of sucrose fatty acid esters with an average degree of esterification ranging from four to seven. It is produced by interesterification of sucrose with methyl esters of fatty acids derived from... preparation of sucrose oligoesters are dimethyl sulfoxide, isobutyl alcohol, and those solvents...

  3. Sucrose transport into stalk tissue of sugarcane

    SciTech Connect

    Thom, M.; Maretzki, A. )

    1990-05-01

    The productivity of higher plants is, in part, dependent on transport of photosynthate from source to sink (in sugarcane, stalk) and upon its assimilation in cells of the sink tissue. In sugarcane, sucrose has been reported to undergo hydrolysis in the apoplast before uptake into the storage parenchyma, whereas recently, sucrose was reported to be taken up intact. This work was based on lack of randomization of ({sup 14}C)fructosyl sucrose accumulated after feeding tissue slices with this sugar. In this report, we present evidence from slices of stalk tissue that sucrose is taken up intact via a carrier-mediated, energy-dependent process. The evidence includes: (1) uptake of fluorosucrose, an analog of sucrose not subject to hydrolysis by invertase; (2) little or no randomization of ({sup 14}C) fructosyl sucrose taken up; (3) the presence of a saturable as well as a linear component of sucrose uptake; and (4) inhibition of both the saturable and linear components of sucrose uptake by protonophore and sulhydryl agents. Hexoses can also be taken up, and at a greater efficiency than sucrose. It is probable that both hexose and sucrose can be transported across the plasma membrane, depending on the physiological status of the plant.

  4. Size-separation of silver nanoparticles using sucrose gradient centrifugation

    DOE PAGES

    Suresh, Anil K.; Pelletier, Dale A.; Moon, Ji Won; ...

    2015-08-28

    Size and shape distributions of nanoparticles can drastically contribute to the overall properties of nanoparticles, thereby influencing their interaction with different chemotherapeutic molecules, biological organisms and or materials and cell types. Therefore, to exploit the proper use of nanoparticles for various biomedical and biosensor applications, it is important to obtain well-separated monodispersed nanoparticles. However, gaining precise control over the morphological characteristics of nanoparticles during their synthesis is often a challenging task. Consequently, post-synthesis separation of nanoparticles is necessary. In the present study, we demonstrate the successful one-pot post-synthesis separation of anisotropic silver nanoparticles to near modispersities using sucrose density gradientmore » sedimentation. The separation of the nanoparticles was evidenced based on optical confirmation, and spectrophotometric and transmission electron microscopy measurements. Our results clearly demonstrate the facile separation of anisotropic silver nanoparticles using sucrose density gradient sedimentation and can enable the use of nanoparticles for various biomedical applications.« less

  5. Size-separation of silver nanoparticles using sucrose gradient centrifugation

    SciTech Connect

    Suresh, Anil K.; Pelletier, Dale A.; Moon, Ji Won; Phelps, Tommy; Doktycz, Mitchel John

    2015-08-28

    Size and shape distributions of nanoparticles can drastically contribute to the overall properties of nanoparticles, thereby influencing their interaction with different chemotherapeutic molecules, biological organisms and or materials and cell types. Therefore, to exploit the proper use of nanoparticles for various biomedical and biosensor applications, it is important to obtain well-separated monodispersed nanoparticles. However, gaining precise control over the morphological characteristics of nanoparticles during their synthesis is often a challenging task. Consequently, post-synthesis separation of nanoparticles is necessary. In the present study, we demonstrate the successful one-pot post-synthesis separation of anisotropic silver nanoparticles to near modispersities using sucrose density gradient sedimentation. The separation of the nanoparticles was evidenced based on optical confirmation, and spectrophotometric and transmission electron microscopy measurements. Our results clearly demonstrate the facile separation of anisotropic silver nanoparticles using sucrose density gradient sedimentation and can enable the use of nanoparticles for various biomedical applications.

  6. Development of alkaline fuel cells.

    SciTech Connect

    Hibbs, Michael R.; Jenkins, Janelle E.; Alam, Todd Michael; Janarthanan, Rajeswari; Horan, James L.; Caire, Benjamin R.; Ziegler, Zachary C.; Herring, Andrew M.; Yang, Yuan; Zuo, Xiaobing; Robson, Michael H.; Artyushkova, Kateryna; Patterson, Wendy; Atanassov, Plamen Borissov

    2013-09-01

    This project focuses on the development and demonstration of anion exchange membrane (AEM) fuel cells for portable power applications. Novel polymeric anion exchange membranes and ionomers with high chemical stabilities were prepared characterized by researchers at Sandia National Laboratories. Durable, non-precious metal catalysts were prepared by Dr. Plamen Atanassovs research group at the University of New Mexico by utilizing an aerosol-based process to prepare templated nano-structures. Dr. Andy Herrings group at the Colorado School of Mines combined all of these materials to fabricate and test membrane electrode assemblies for single cell testing in a methanol-fueled alkaline system. The highest power density achieved in this study was 54 mW/cm2 which was 90% of the project target and the highest reported power density for a direct methanol alkaline fuel cell.

  7. [Importance of sucrose in cognitive functions: knowledge and behavior].

    PubMed

    Zamora Navarro, Salvador; Pérez Llamas, Francisca

    2013-07-01

    Sucrose is not present in the internal milieu as such, so it is physically impossible that it may have a direct influence on cognitive functions, behaviour and knowledge. However, during the digestive process, disaccharides are released into monosaccharides, in the case of sucrose into glucose and fructose, which reach the liver via the portal vein. Finally, they go into bloodstream in the form of glucose and in some cases as very low-density lipoproteins (VLDL). Brain needs almost exclusively a constant supply of glucose from the bloodstream. Adult brain requires about 140 g of glucose per day, which represents up to a 50% of total carbohydrates consumed daily in the diet. The consumption of a food or beverage enriched with sucrose has been associated with improved mental alertness, memory, reaction time, attention and ability to solve mathematical problems, as well as a reduction in the feeling of fatigue, both in healthy individuals and patients with Alzheimer disease. An adequate nutrition of brain contributes to structural and functional integrity of neurons. It has been shown that in major mental illnesses such as schizophrenia, depression and Alzheimer's disease, nutritional deficiencies at cellular level are implicated. At present, several studies highlight the need to improve understanding of the processes involved in the deterioration of cognitive functions and mechanisms through which, the nutritive components of the diet, particularly the sucrose, may modulate such functions.

  8. Sucrose synthesis in gamma irradiated sweet potato

    SciTech Connect

    Ailouni, S.; Hamdy, M.K.; Toledo, R.T.

    1987-01-01

    Effect of ..cap alpha..-irradiation carbohydrate metabolism was examined to elucidate mechanism of sucrose accumulation in sweet potato (SP). Enzymes examined were: ..beta..-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase, sucrose phosphate synthetase and sucrose synthetase. Irradiated SP (Red Jewell) sucrose was synthesized to yield 10.7% after 4 d PI. Activities of sugar synthesizing enzymes in irradiated SP were enhanced to different degrees using 100-200 Krad and 3 d PI at 24/sup 0/C. Phosphorylase and phosphoglucomutases specific activities reached 2.4 and 1.8 folds, respectively compared to control SP. ..beta..-amylase, phosphoglucose isomerase, sucrose synthetase and sucrose phosphate synthetase were also affected to yield 1.2, 1.3, 1.3 and 1.2 folds, respectively compared to controls. It is believed that amylase hydrolyzed starch to glucose which is converted to fructose by phosphoglucose isomerase. Sucrose is then formed by sucrose phosphate synthetase and/or sucrose synthetase leading to its accumulation. The irradiated SP was used for alcohol fermentation leading to 500 gal. of 200 proof ethanol/acre (from 500-600 bushels tuber/acre).

  9. Characteristics Of Vacuum Deposited Sucrose Thin Films

    NASA Astrophysics Data System (ADS)

    Ungureanu, F.; Predoi, D.; Ghita, R. V.; Vatasescu-Balcan, R. A.; Costache, M.

    Thin films of sucrose (C12H22O11) were deposited on thin cut glass substrates by thermal evaporation technique (p ~ 10-5 torr). The surface morphology was putted into evidence by FT-IR and SEM analysis. The experimental results confirm a uniform deposition of an adherent sucrose layer. The biological tests (e.g., cell morphology and cell viability evaluated by measuring mitochondrial dehydrogenise activity with MTT assay) confirm the properties of sucrose thin films as bioactive material. The human fetal osteoblast system grown on thin sucrose film was used for the determination of cell proliferation, cell viability and cell morphology studies.

  10. Alkaline Capacitors Based on Nitride Nanoparticles

    NASA Technical Reports Server (NTRS)

    Aldissi, Matt

    2003-01-01

    High-energy-density alkaline electrochemical capacitors based on electrodes made of transition-metal nitride nanoparticles are undergoing development. Transition- metal nitrides (in particular, Fe3N and TiN) offer a desirable combination of high electrical conductivity and electrochemical stability in aqueous alkaline electrolytes like KOH. The high energy densities of these capacitors are attributable mainly to their high capacitance densities, which, in turn, are attributable mainly to the large specific surface areas of the electrode nanoparticles. Capacitors of this type could be useful as energy-storage components in such diverse equipment as digital communication systems, implanted medical devices, computers, portable consumer electronic devices, and electric vehicles.

  11. Sucrose accumulation in mature sweet melon fruits. [Cucumis melo

    SciTech Connect

    Schaffer, A.A.; Aloni, B.

    1987-04-01

    Mesocarp tissue from sucrose-accumulating sweet melon (Cucumis melo cv. Galia) showed sucrose synthase activity (ca 1 nkat/gfw) while soluble acid invertase and sucrose phosphate synthase activities were not observed. Sucrose uptake into mesocarp discs was linear with sucrose concentration (1-500 mM) and unaffected by PCMBS and CCCP. Sucrose compartmentation into the vacuole also increased linearly with sucrose concentration as indicated by compartmental efflux kinetics. Mesocarp discs incubated in /sup 14/C-fructose + UDP-glu synthesized /sup 14/C-sucrose and efflux kinetics indicated that the /sup 14/C-sucrose was compartmentalized. These data support the hypothesis that two mechanisms are involved in sucrose accumulation in sweet melon: (1) compartmentation of intact sucrose and (2) synthesis of sucrose via sucrose synthase and subsequent compartmentation in the vacuole.

  12. Sugarcane genes associated with sucrose content

    PubMed Central

    Papini-Terzi, Flávia S; Rocha, Flávia R; Vêncio, Ricardo ZN; Felix, Juliana M; Branco, Diana S; Waclawovsky, Alessandro J; Del Bem, Luiz EV; Lembke, Carolina G; Costa, Maximiller DL; Nishiyama, Milton Y; Vicentini, Renato; Vincentz, Michel GA; Ulian, Eugênio C; Menossi, Marcelo; Souza, Glaucia M

    2009-01-01

    Background - Sucrose content is a highly desirable trait in sugarcane as the worldwide demand for cost-effective biofuels surges. Sugarcane cultivars differ in their capacity to accumulate sucrose and breeding programs routinely perform crosses to identify genotypes able to produce more sucrose. Sucrose content in the mature internodes reach around 20% of the culms dry weight. Genotypes in the populations reflect their genetic program and may display contrasting growth, development, and physiology, all of which affect carbohydrate metabolism. Few studies have profiled gene expression related to sugarcane's sugar content. The identification of signal transduction components and transcription factors that might regulate sugar accumulation is highly desirable if we are to improve this characteristic of sugarcane plants. Results - We have evaluated thirty genotypes that have different Brix (sugar) levels and identified genes differentially expressed in internodes using cDNA microarrays. These genes were compared to existing gene expression data for sugarcane plants subjected to diverse stress and hormone treatments. The comparisons revealed a strong overlap between the drought and sucrose-content datasets and a limited overlap with ABA signaling. Genes associated with sucrose content were extensively validated by qRT-PCR, which highlighted several protein kinases and transcription factors that are likely to be regulators of sucrose accumulation. The data also indicate that aquaporins, as well as lignin biosynthesis and cell wall metabolism genes, are strongly related to sucrose accumulation. Moreover, sucrose-associated genes were shown to be directly responsive to short term sucrose stimuli, confirming their role in sugar-related pathways. Conclusion - Gene expression analysis of sugarcane populations contrasting for sucrose content indicated a possible overlap with drought and cell wall metabolism processes and suggested signaling and transcriptional regulators to be

  13. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  14. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  15. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  16. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... CONSUMPTION Multipurpose Additives § 172.859 Sucrose fatty acid esters. Sucrose fatty acid esters identified...) Sucrose fatty acid esters are the mono-, di-, and tri-esters of sucrose with fatty acids and are...

  17. Reducing sucrose loss in sugarbeet storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose loss in sugarbeet storage is a considerable problem which is negatively influenced by environmental conditions, stress on roots from disease problems in the field, rough handling during harvest and transport, and microbial growth. To reduce sucrose loss in sugarbeet storage, studies were in...

  18. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ....1854 Sucrose. (a) Sucrose (C12H22O11, CAS Reg. No. 57-50-11-1) sugar, cane sugar, or beet sugar is the... sugar beet juice that has been extracted by pressing or diffusion, then clarified and evaporated....

  19. [The determination of glucose, sucrose and fructose by the method of capillary electrophoresis].

    PubMed

    Yakuba, Yu F; Markovsky, M G

    2015-01-01

    The possibilities of different regimes of micellar capillary electrophoresis using negative polarity and alkaline electrolyte for determination of glucose, sucrose, fructose in extracts of vegetative organs of plants and products of fruits and grapes processing have been studied. A comparative evaluation of the limits of detection of glucose, sucrose, fructose for developed electrolytes have been performed, the advantages and disadvantages of techniques have been discussed. It is recommended to use an aqueous electrolyte containing 0.5% potassium sorbate, 0.62% cetyltrimethylammonium bromide, and 0.02% potassium hydroxide. The analyzed components were detected at 254 nm. The sample was dosed hydrodynamically (30 mbar, 5 sec). Negative voltage 16 kV is recommended, current--54 ± 4 µA, capillary thermostating at 24 °C is applied, the analysis time--15 min. The detection limits for fructose and glucose is 0.03 g/dm3 to 0.07 g of sucrose/dm3. Linearity is stored for each component to 5.0 g/dm 3 inclusive. Electrophoretic mobility of carbohydrates was (10(-4) sm2V(-1)sec(-1)): fructose--3.12, glucose--3.03, sucrose--2.74. Approximate time of release: glucose--13 min, sucrose--13.5 min, fructose--12.5 min. The developed options for mass concentration determining of mono- and disaccharides provide complete separation of the components. Anions, glycerol, ethylene glycol, propylene glycol and butylene isomers do not affect the analysis results.

  20. Sucrose-mediated transcriptional regulation of sucrose symporter activity in the phloem.

    SciTech Connect

    Matt Vaughn Greg Harrington Daniel R Bush

    2002-08-06

    This project was based on our discovery that sucrose acts as a signaling molecule that regulates the activity of a proton-sucrose symporter in sugar beet leaf tissue. A major objective here was determining how sucrose transporter activity is being regulated. When sucrose accumulates in the phloem sucrose transport activity drops dramatically. Western blots of plasma membrane proteins isolated from sucrose treated leaves showed that the loss of sucrose transport activity was proportional to a decline in symporter abundance, demonstrating that sucrose transport is regulated by changes in the amount of BvSUT1 protein. BvSUT1 transcript levels decreased in parallel with the loss of sucrose transport activity. Nuclear run-on experiments demonstrated that BvSUT1 gene transcription was repressed significantly in nuclei from leaves fed 100 mM exogenous sucrose, showing that sucrose-dependent modulation of BvSUT1 mRNA levels is mediated by changes in transcription. To identify which secondary messenger systems might be involved in regulating symporter activity, we used a variety of pharmacological agents to probe for a role of calcium or protein phosphorylation in sucrose signaling. In a detailed analysis, only okadaic acid altered sucrose transport activity. These results suggest a protein phosphatase is involved. We hypothesized that protein kinase inhibitors would have a neutral affect or increase symporter transcription. Transpirational feeding of the protein kinase inhibitor staurosporine had no impact on sucrose transport while calphostin C, an inhibitor of protein kinase C, caused a 60% increase. These data provided good evidence that protein phosphorylation plays a central role in regulating sucrose symporter expression and sucrose transport activity. To determine whether protein phosphorylation is involved in sucrose regulation of proton-sucrose symporter activity, we pre-fed leaves with staurosporine for 4 h and then fed the treated leaves water or 100 mM sucrose

  1. Impact of weighting agents and sucrose on gravitational separation of beverage emulsions.

    PubMed

    Chanamai, R; McClements, D J

    2000-11-01

    The influence of weighting agents and sucrose on gravitational separation in 1 wt % oil-in-water emulsions was studied by measuring changes in the intensity of backscattered light from the emulsions with height. Emulsions with different droplet densities were prepared by mixing weighting agents [brominated vegetable oil (BVO), ester gum (EG), damar gum (DG), or sucrose acetate isobutyrate (SAIB)] with soybean oil prior to homogenization. Sedimentation or creaming occurred when the droplet density was greater than or lower than the aqueous phase density, respectively. The weighting agent concentrations required to match the oil and aqueous phase densities were 25 wt % BVO, 55 wt % EG, 55 wt % DG, and 45 wt % SAIB. The efficiency of droplet reduction during homogenization also depended on weighting agent type (BVO > SAIB > DG, EG) due to differences in oil phase viscosity. The influence of sucrose (0-13 wt %) on the creaming stability of 1 wt % soybean oil-in-water emulsions was also examined. Sucrose increased the aqueous phase viscosity (retarding creaming) and increased the density contrast between droplets and aqueous phase (accelerating creaming). These two effects largely canceled one another so that the creaming stability was relatively insensitive to sucrose concentration.

  2. Enzymatic conversion of sucrose to hydrogen

    SciTech Connect

    Woodward, J.; Orr, M.

    1998-11-01

    The enzymatic conversion of sugars to hydrogen could be a promising method for alternative fuel production. Maple tree sap is a source of environmental sugar (e.g., sucrose) that has the potential to be converted into hydrogen using the enzymes invertase, glucose dehydrogenase (GDH), hydrogenase, and glucose isomerase (GI) and the cofactor NADP{sup +}/NADPH. The kinetics of hydrogen production have been studied, and optimal conditions for hydrogen production are described. At low initial sucrose concentrations, in the absence of glucose isomerase, stoichiometric yields of mol of H{sub 2}/mol of sucrose were achieved. At higher sucrose concentrations, the yield of hydrogen declined so that at an initial sucrose concentration of 292 mM only 7% yield of hydrogen was obtained. The reason for this low yield was studied and shown not to be caused by enzyme inactivation or a pH drop during the reaction but due to an instability of the cofactor NADP{sup +}. Although gluconic and inhibited both NADPH production and oxidation of GDH and hydrogenase, respectively, it was not the major cause of NADP{sup +} instability. Fructose was also shown to be converted to hydrogen if GI was present in the reaction mixture. Also, by starting with sucrose, 1.34 mol of H{sub 2}/mol of sucrose was obtained if GI was present in the reaction mixture.

  3. Functional Analysis of Arabidopsis Sucrose Transporters

    SciTech Connect

    John M. Ward

    2009-03-31

    Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.

  4. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  5. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sugar, or beet sugar is the chemical β-D-fructofuranosyl-α-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion,...

  6. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sugar, or beet sugar is the chemical β-D-fructofuranosyl-α-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion,...

  7. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sugar, or beet sugar is the chemical β-D-fructofuranosyl-α-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion,...

  8. 21 CFR 184.1854 - Sucrose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sugar, or beet sugar is the chemical β-D-fructofuranosyl-α-D-glucopyranoside. Sucrose is obtained by crystallization from sugar cane or sugar beet juice that has been extracted by pressing or diffusion,...

  9. 21 CFR 172.869 - Sucrose oligoesters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... dimethyl sulfoxide, isobutyl alcohol, and those solvents generally recognized as safe in food. (b) Sucrose... Convention, 12601 Twinbrook Pkwy., Rockville, MD 20852 (Internet address http://www.usp.org) (7) Residue...

  10. Structural development of sucrose-sweetened and sucrose-free sponge cakes during baking.

    PubMed

    Baeva, Marianna Rousseva; Terzieva, Vesselina Velichkova; Panchev, Ivan Nedelchev

    2003-06-01

    The influence of sucrose, wheat starch and sorbitol upon the heat- and mass-exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose-free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose-sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time--between 18th and 19th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven "Rahovetz-02", Bulgaria for 30 min at 180 degrees C). The water-losses at the end of baking (10.30% and 10.40% for the sucrose-sweetened cake and sucrose-free cake, respectively) and the final temperatures reached in the crumb central layers (96.6 degrees C and 96.3 degrees C for the sucrose-sweetened cake and sucrose-free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose-free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm3 and 984.25 cm3) of the sucrose-sweetened and sucrose-free sponge cakes, respectively. As a result, the sucrose-free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that ofthe sucrose-sweetened one.

  11. The quest for a thermostable sucrose phosphorylase reveals sucrose 6'-phosphate phosphorylase as a novel specificity.

    PubMed

    Verhaeghe, Tom; Aerts, Dirk; Diricks, Margo; Soetaert, Wim; Desmet, Tom

    2014-08-01

    Sucrose phosphorylase is a promising biocatalyst for the glycosylation of a wide range of compounds, but its industrial application has been hampered by the low thermostability of known representatives. Hence, in this study, the putative sucrose phosphorylase from the thermophile Thermoanaerobacterium thermosaccharolyticum was recombinantly expressed and fully characterised. The enzyme showed significant activity on sucrose (optimum at 55 °C), and with a melting temperature of 79 °C and a half-life of 60 h at the industrially relevant temperature of 60 °C, it is far more stable than known sucrose phosphorylases. Substrate screening and detailed kinetic characterisation revealed however a preference for sucrose 6'-phosphate over sucrose. The enzyme can thus be considered as a sucrose 6'-phosphate phosphorylase, a specificity not yet reported to date. Homology modelling and mutagenesis pointed out particular residues (Arg134 and His344) accounting for the difference in specificity. Moreover, phylogenetic and sequence analysis suggest that glycoside hydrolase 13 subfamily 18 might harbour even more specificities. In addition, the second gene residing in the same operon as sucrose 6'-phosphate phosphorylase was identified as well, and found to be a phosphofructokinase. The concerted action of both these enzymes implies a new pathway for the breakdown of sucrose, in which the reaction products end up at different stages of the glycolysis.

  12. Alkaline battery operational methodology

    DOEpatents

    Sholklapper, Tal; Gallaway, Joshua; Steingart, Daniel; Ingale, Nilesh; Nyce, Michael

    2016-08-16

    Methods of using specific operational charge and discharge parameters to extend the life of alkaline batteries are disclosed. The methods can be used with any commercial primary or secondary alkaline battery, as well as with newer alkaline battery designs, including batteries with flowing electrolyte. The methods include cycling batteries within a narrow operating voltage window, with minimum and maximum cut-off voltages that are set based on battery characteristics and environmental conditions. The narrow voltage window decreases available capacity but allows the batteries to be cycled for hundreds or thousands of times.

  13. 21 CFR 172.859 - Sucrose fatty acid esters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sucrose fatty acid esters. 172.859 Section 172.859... Sucrose fatty acid esters. Sucrose fatty acid esters identified in this section may be safely used in accordance with the following prescribed conditions: (a) Sucrose fatty acid esters are the mono-, di-,...

  14. Modulation of receptors and adenylate cyclase activity during sucrose feeding, food deprivation, and cold exposure

    SciTech Connect

    Scarpace, P.J.; Baresi, L.A.; Morley, J.E. Univ. of California, Los Angeles )

    1987-12-01

    Thermogenesis in brown adipose tissue (BAT) serves as a regulator of body temperature and weight maintenance. Thermogenesis can be stimulated by catecholamine activation of adenylate cyclase through the {beta}-adrenergic receptor. To investigate the effects of sucrose feeding, food deprivation, and cold exposure on the {beta}-adrenergic pathway, adenylate cyclase activity and {beta}-adrenergic receptors were assessed in rat BAT after 2 wk of sucrose feeding, 2 days of food deprivation, or 2 days of cold exposure. {beta}-Adrenergic receptors were identified in BAT using ({sup 125}I)iodocyanopindolol. Binding sites had the characteristics of mixed {beta}{sub 1}- and {beta}{sub 2}-type adrenergic receptors at a ratio of 60/40. After sucrose feeding or cold exposure, there was the expected increase in BAT mitochondrial mass as measured by total cytochrome-c oxidase activity but a decrease in {beta}-adrenergic receptor density due to a loss of the {beta}{sub 1}-adrenergic subtype. This BAT {beta}-adrenergic receptor downregulation was tissue specific, since myocardial {beta}-adrenergic receptors were unchanged with either sucrose feeding or cold exposure. Forskolin-stimulated adenylate cyclase activity increased in BAT after sucrose feeding or cold exposure but not after food deprivation. These data suggest that in BAT, sucrose feeding or cold exposure result in downregulation of {beta}-adrenergic receptors and that isoproterenol-stimulated adenylate cyclase activity was limited by receptor availability.

  15. Extended Exposure to Environmental Cues, but not to Sucrose, Reduces Sucrose Cue-reactivity in Rats

    PubMed Central

    Harkness, John H.; Wells, Jason; Webb, Sierra; Grimm, Jeffrey W.

    2015-01-01

    The present study examined the effect of extinction of sucrose-predictive contextual cues and/or sucrose satiation on the expression of sucrose cue-reactivity in a rat model of relapse. Context extinction was imposed by housing rats in their home cage or in the operant conditioning chamber for 17 hours prior to testing. For sucrose satiation, rats were allowed unlimited access to water or sucrose for 17 hours prior to testing. Cue-reactivity was assessed after either 1 (Day 1) or 30 (Day 30) days of forced abstinence from sucrose self-administration. An abstinence-dependent increase in sucrose cue-reactivity was observed in all conditions (“incubation of craving”). Context extinction dramatically reduced lever responding on both Day 1 and Day 30. Sucrose satiation had no significant effect on cue-reactivity in any condition. These results demonstrate that the context in which self-administration occurred maintains a powerful influence over cue-reactivity even after extended forced abstinence. In contrast, the primary reinforcer has little control over cue-reactivity. These findings highlight the important role of conditioned contextual cues in driving relapse behavior. PMID:26169836

  16. Current studies on sucrose isomerase and biological isomaltulose production using sucrose isomerase.

    PubMed

    Mu, Wanmeng; Li, Wenjing; Wang, Xiao; Zhang, Tao; Jiang, Bo

    2014-08-01

    Isomaltulose is a natural isomer of sucrose. It is widely used as a functional sweetener with promising properties, including slower digestion, lower glycemic index, prolonged energy release, lower insulin reaction, and less cariogenicity. It has been approved as a safe sucrose substitute by the Food and Drug Administration of the US; Ministry of Health, Labor and Welfare of Japan; and the Commission of the European Communities. This article presents a review of recent studies on the properties, physiological effects, and food application of isomaltulose. In addition, the biochemical properties of sucrose isomerases producing isomaltulose are compared; the heterologous expression, fermentation optimization, structural determination, and catalysis mechanism of sucrose isomerase are reviewed; and the biotechnological production of isomaltulose from sucrose is summarized.

  17. Fermentation pattern of sucrose to ethanol conversions by Zymomonas mobilis

    SciTech Connect

    Lyness, Ed.; Doelle, H.W.

    1981-07-01

    General patterns of sucrose fermentation by two strains of Zymomonas mobilis, designated Z7 and Z10, were established using sucrose concentrations from 50 to 200 g/liter. Strain Z7 showed a higher invertase activity than Z10. Strain Z10 showed a reduced specific growth rate a high sucrose concentrations while Z7 was unaffected. High sucrose hydrolyzing activity in strain Z7 lead to glucose accumulation in the medium at high sucrose concentrations. Ethanol production and fermentation time depend on the rate of catabolism of the products of sucrose hydrolysis, glucose and fructose. 10 refs.

  18. 27 CFR 21.131 - Sucrose octaacetate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... using phenolphthalein indicator. Percent acid as acetic acid=ml NaOH used×0.6/ weight of sample (c... phenolphthalein indicator. Percent sucrose octaacetate=(ml NaOH−ml H2SO4)×4.2412/weight of sample...

  19. 21 CFR 172.869 - Sucrose oligoesters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... milligram/kilogram “Atomic Absorption Spectrophotometric Graphite Furnace Method,” Method I, in the Food... recognized as safe in food. (b) Sucrose oligoesters meet the specifications in the methods listed in the table in this paragraph. The methods cited for determining compliance with each specification...

  20. 21 CFR 172.869 - Sucrose oligoesters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... milligram/kilogram “Atomic Absorption Spectrophotometric Graphite Furnace Method,” Method I, in the Food... recognized as safe in food. (b) Sucrose oligoesters meet the specifications in the methods listed in the table in this paragraph. The methods cited for determining compliance with each specification...

  1. Alkaline flooding injection strategy

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1992-03-01

    The objective of this project is to improved alkali-surfactant flooding methods, and this includes determining the proper design of injection strategy. Several different injection strategies have been used or suggested for recovering heavy oils with surfactant-enhanced alkaline flooding methods. Oil recovery was compared for four different injection strategies: (1) surfactant followed by polymer, (2) surfactant followed by alkaline polymer, (3) alkaline surfactant followed by polymer, and (4) alkali, surfactant, and polymer mixed in a single formulation. The effect of alkaline preflush was also studied under two different conditions. All of the oil recovery experiments were conducted under optimal conditions with a viscous, non-acidic oil from Hepler (KS) oil field. The coreflood experiments were conducted with Berea sandstone cores since field core was not available in sufficient quantity for coreflood tests. The Tucker sand of Hepler field is a Class I fluvial dominated deltaic reservoir, as classified by the Department of Energy, which has been selected as the site of a DOE-sponsored field pilot test.

  2. Fermentation pattern of sucrose to ethanol conversions by Zymomonas mobilis

    SciTech Connect

    Lyness, E.; Doelle, H.W.

    1981-07-01

    General patterns of sucrose fermentation by two strains of Zymomonas mobilis, designated Z7 and Z10, were established using sucrose concentrations from 50 to 200 g/liter. Strain Z7 showed a higher invertase activity than Z10. Strain Z10 showed a reduced specific growth rate at high sucrose concentrations while Z7 was unaffected. High sucrose hydrolyzing activity in strain Z7 lead to glucose accumulation in the medium at high sucrose concentrations. Ethanol production and fermentation time depend on the rate of catabolism of the products of sucrose hydrolysis, glucose and fructose. The metabolic quotients for sucrose utilization, qs, and ethanol production, qp (g/g.hr), are unsuitable for describing sucrose utilization by Zymomonas mobilis as the logarithmic phase of growth precedes the phase of highest substrate utilization (g/liter.hr) and ethanol production (g/liter.hr) in batch culture. (Refs. 10).

  3. Succinic acid production from sucrose by Actinobacillus succinogenes NJ113.

    PubMed

    Jiang, Min; Dai, Wenyu; Xi, Yonglan; Wu, Mingke; Kong, Xiangping; Ma, Jiangfeng; Zhang, Min; Chen, Kequan; Wei, Ping

    2014-02-01

    In this study, sucrose, a reproducible disaccharide extracted from plants, was used as the carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. During serum bottle fermentation, the succinic acid concentration reached 57.1g/L with a yield of 71.5%. Further analysis of the sucrose utilization pathways revealed that sucrose was transported and utilized via a sucrose phosphotransferase system, sucrose-6-phosphate hydrolase, and a fructose PTS. Compared to glucose utilization in single pathway, more pathways of A. succinogenes NJ113 are dependent on sucrose utilization. By changing the control strategy in a fed-batch culture to alleviate sucrose inhibition, 60.5g/L of succinic acid was accumulated with a yield of 82.9%, and the productivity increased by 35.2%, reaching 2.16g/L/h. Thus utilization of sucrose has considerable potential economics and environmental meaning.

  4. Contributions of sucrose synthase and invertase to the metabolism of sucrose in developing leaves: estimation by alternate substrate utilization

    SciTech Connect

    Schmalstig, J.G.; Hitz, W.D.

    1987-10-01

    The relative contributions of invertase and sucrose synthase to initial cleavage of phloem-imported sucrose was calculated for sink leaves of soybean (Glycine max L. Merr cv Wye) and sugar beet (Beta vulgaris L. monohybrid). Invertase from yeast hydrolyzed sucrose 4200 times faster than 1'-deoxy-1'-fluorosucrose (FS) while sucrose cleavage by sucrose synthase from developing soybean leaves proceeded only 3.6 times faster than cleavage of FS.(/sup 14/C)Sucrose and (/sup 14/C)FS, used as tracers of sucrose, were transported at identical rates to developing leaves through the phloem. The rate of label incorporation into insoluble products varied with leaf age from 3.4 to 8.0 times faster when (/sup 14/C)sucrose was supplied than when (/sup 14/C)FS was supplied. The discrimination in metabolism was related to enzymatic discriminations against FS to calculate the relative contributions of invertase and sucrose synthase to sucrose cleavage. In the youngest soybean leaves measured, 4% of final laminar length (FLL), all cleavage was by sucrose synthase. Invertase contribution to sucrose metabolism was 47% by 7.6% FLL, increased to 54% by 11% FLL, then declined to 42% for the remainder of the import phase. In sugar beet sink leaves at 30% FLL invertase contribution to sucrose metabolism was 58%.

  5. Functional analysis of sucrose phosphate synthase (SPS) and sucrose synthase (SS) in sugarcane (Saccharum) cultivars.

    PubMed

    Verma, A K; Upadhyay, S K; Verma, P C; Solomon, S; Singh, S B

    2011-03-01

    Sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13) are key enzymes in the synthesis and breakdown of sucrose in sugarcane. The activities of internodal SPS and SS, as well as transcript expression were determined using semi-quantitative RT-PCR at different developmental stages of high and low sucrose accumulating sugarcane cultivars. SPS activity and transcript expression was higher in mature internodes compared with immature internodes in all the studied cultivars. However, high sugar cultivars showed increased transcript expression and enzyme activity of SPS compared to low sugar cultivars at all developmental stages. SS activity was higher in immature internodes than in mature internodes in all cultivars; SS transcript expression showed a similar pattern. Our studies demonstrate that SPS activity was positively correlated with sucrose and negatively correlated with hexose sugars. However, SS activity was negatively correlated with sucrose and positively correlated with hexose sugars. The present study opens the possibility for improvement of sugarcane cultivars by increasing expression of the respective enzymes using transgene technology.

  6. Bifunctional sucrose phosphate synthase/phosphatase is involved in the sucrose biosynthesis by Methylobacillus flagellatus KT.

    PubMed

    But, Sergey Y; Khmelenina, Valentina N; Reshetnikov, Alexander S; Trotsenko, Yuri A

    2013-10-01

    The aerobic obligate methylotroph Methylobacillus flagellatus KT was shown to synthesize sucrose in the presence of 0.5-2% NaCl in the growth medium. In the genome of this bacterium, an open reading frame (ORF) encoding a predicted 84-kD polypeptide homologous to the plant and cyanobacterial sucrose phosphate synthases (SPSs) was found. Using heterologous expression of the putative sps gene in Escherichia coli, followed by affinity chromatography, pure recombinant protein SPS-His6 was obtained. The enzyme catalyzed two reactions: conversion of fructose 6-phosphate and UDP-glucose into sucrose 6-phosphate and hydrolysis of sucrose 6-phosphate to sucrose. The bifunctional sucrose phosphate synthase/phosphatase (SPS/SPP) was a 340 kDa homotetrameric Mg(2+) -dependent enzyme activated by fructose 1,6-phosphate2 and ATP but inhibited by glucose 6-phosphate, fructose 1-phosphate, AMP and inorganic phosphate. The amino acid sequence of the protein had a C-terminal domain homologous to SPPs. This correlated with the absence of the spp gene in the M. flagellatus chromosome. The ORFs homologous to the M. flagellatus SPS were found in the genomes of another obligate methylotroph Methylovorus glucosetrophus as well as the lithoautotrophic bacteria Acidithiobacillus ferrooxidans, Nitrosomonas europaea and Nitrosospira multiformis whose genomes lacked the spp genes. Thus, data extending the knowledge of biochemical properties of bacterial SPSs have been obtained.

  7. Fermentation of five sucrose isomers by human dental plaque bacteria.

    PubMed

    Matsuyama, J; Sato, T; Hoshino, E; Noda, T; Takahashi, N

    2003-01-01

    Sucrose has five structural isomers: palatinose, trehalulose, turanose, maltulose and leucrose. Although these isomers have been reported to be noncariogenic disaccharides, which cannot be utilized by mutans streptococci, there is no information about their fermentability by other bacteria in dental plaque. The purpose of the present study was to examine whether these isomers were fermented by predominant bacteria in human dental plaque. Clinical bacterial isolates obtained from dental plaque from 3 children aged 22 months to 50 months (146 strains) were inoculated into 3 ml of peptone-yeast extract (PY medium) containing glucose for 1 day, then an aliquot of 20 microl of culture medium was inoculated into 1 ml of PY medium containing 1% (w/v) of the respective test carbohydrates. After incubation for 1 day, the pH values and the optical density at 660 nm of the cultures were measured. Fermentation ability was measured by pH or=0.5. Of the clinical isolates, 33% fermented palatinose, and 69% of these were Actinomyces species. All of the palatinose-fermenting bacterial strains fermented trehalulose, 25% fermented turanose, 70% fermented maltulose and 23% fermented leucrose. We therefore conclude that, in human dental plaque, there are significant numbers of bacteria that are able to ferment sucrose isomers.

  8. Effect of exogenous sucrose on the enzymes of starch degradation and sucrose metabolism in cowpea (Vigna unguiculata L.) seedlings.

    PubMed

    Kaur, Narinder; Kaur, Harpreet; Gupta, Anil K

    2005-10-01

    Addition of exogenous sucrose and mannitol in the growth medium decreased the germination and growth of cowpea (Vigna unguiculata L. cv C-88) seedlings. The reduced seedling growth appeared to be due to the decreased acid invertase activity in growing parts of the seedlings. An exogenous supply of sucrose upregulated the sucrose phosphate synthase (SPS) activity in different parts of seedlings. Decreased amylase activity in cotyledons and the mobilization of starch from cotyledons to the growing axis was observed in the presence of exogenous sucrose and mannitol. High sucrose content observed in different tissues in the presence of exogenous sucrose and mannitol was possibly due to high SPS and low acid invertase activities and reduced conversion of sucrose to starch. It appears that exogenous sucrose acts mainly as an osmoticum, rather than a source of carbon for the growing seedlings.

  9. Characterization of a sucrose/starch matrix through positron annihilation lifetime spectroscopy: unravelling the decomposition and glass transition processes.

    PubMed

    Sharma, Sandeep Kumar; Roudaut, Gaëlle; Fabing, Isabelle; Duplâtre, Gilles

    2010-11-14

    The triplet state of positronium, o-Ps, is used as a probe to characterize a starch-20% w/w sucrose matrix as a function of temperature (T). A two-step decomposition (of sucrose, and then starch) starts at 440 K as shown by a decrease in the o-Ps intensity (I(3)) and lifetime (τ(3)), the latter also disclosing the occurrence of a glass transition. Upon sucrose decomposition, the matrix acquires properties (reduced size and density of nanoholes) that are different from those of pure starch. A model is successfully established, describing the variations of both I(3) and τ(3) with T and yields a glass transition temperature, T(g) = (446 ± 2) K, in spite of the concomitant sucrose decomposition. Unexpectedly, the starch volume fraction (as probed through thermal gravimetry) decreases with T at a higher rate than the free volume fraction (as probed through PALS).

  10. Prenatal ethanol increases sucrose reinforcement, an effect strengthened by postnatal association of ethanol and sucrose.

    PubMed

    Culleré, Marcela Elena; Spear, Norman E; Molina, Juan Carlos

    2014-02-01

    Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14-17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy.

  11. Prenatal Ethanol Increases Sucrose Reinforcement, an Effect Strengthened by Postnatal Association of Ethanol and Sucrose

    PubMed Central

    Culleré, Marcela Elena; Spear, Norman E.; Molina, Juan Carlos

    2014-01-01

    Late prenatal exposure to ethanol recruits sensory processing of the drug and of its motivational properties, an experience that leads to heightened ethanol affinity. Recent studies indicate common sensory and neurobiological substrates between this drug and sweet tastants. Using a recently developed operant conditioning technique for infant rats, we examined the effects of prenatal ethanol history upon sucrose self-administration (postnatal days, PDs 14–17). Prior to the last conditioning session, a low (0.5 g/kg) or a high (2.5 g/kg) ethanol dose were paired with sucrose. The intention was to determine if ethanol would inflate or devalue the reinforcing capability of the tastant and if these effects are dependent upon prenatal ethanol history. Male and female pups prenatally exposed to ethanol (2.0 g/kg) responded more when reinforced with sucrose than pups lacking this antenatal experience. Independently of prenatal status, a low ethanol dose (0.5 g/kg) enhanced the reinforcing capability of sucrose while the highest dose (2.5 g/kg) seemed to ameliorate the motivational properties of the tastant. During extinction (PD 18), two factors were critical in determining persistence of responding despite reinforcement omission. Pups prenatally exposed to ethanol that subsequently experienced the low ethanol dose paired with sucrose, showed higher resistance to extinction. The effects here reported were not associated with differential blood alcohol levels across prenatal treatments. These results indicate that fetal ethanol experience promotes affinity for a natural sweet reinforcer and that low doses of ethanol are also capable of enhancing the positive motivational consequences of sucrose when ethanol and sucrose are paired during infancy. PMID:24398347

  12. Translocation of labelled sucrose: A student exercise

    SciTech Connect

    Reiss, C. )

    1990-05-01

    Photosynthetic carbohydrates from the leaves are exported through the phloem to growing tips, roots, flowers and fruits. If sucrose labelled with {sup 14}C is applied to the leaves of bean plants, the pathway for sugar movement may be readily observed by autoradiography. Students apply the labelled sucrose during class time and return the next day to press their plants. During the next class, the pressed and dried plants are placed against X-ray film and left in the dark for four weeks. the film is then developed, examined for presence of label and compared to the pressed plants. Source to sink movement is clearly illustrated and information about the mechanism of phloem transport and loading is gained through experimental treatments, which include blocking the phloem pathway and inhibiting energy production.

  13. Withanolides and Sucrose Esters from Physalis neomexicana.

    PubMed

    Cao, Cong-Mei; Wu, Xiaoqing; Kindscher, Kelly; Xu, Liang; Timmermann, Barbara N

    2015-10-23

    Four withanolides (1-4) and two sucrose esters (5, 6) were isolated from the aerial parts of Physalis neomexicana. The structures of 1-6 were elucidated through a variety of spectroscopic techniques. Cytotoxicity studies of the isolates revealed that 2 inhibited human breast cancer cell lines (MDA-MB-231 and MCF-7) with IC50 values of 1.7 and 6.3 μM, respectively.

  14. Purification and properties of molecular-weight variants of human placental alkaline phosphatase

    PubMed Central

    Ghosh, Nimai K.; Fishman, William H.

    1968-01-01

    1. Alkaline phosphatase of human placenta was purified by a procedure involving homogenization with tris buffer, pH8·6, extraction with butanol, ammonium sulphate fractionation, exposure to heat, ethanol fractionation, gel filtration, triethylaminoethylcellulose anion-exchange chromatography, continuous curtain electrophoresis on paper and equilibrium dialysis. Methods for both laboratory-scale and large-scale preparation were devised. 2. Two major molecular-weight variants designated A and B were separated by molecular sieving with Sephadex G-200 and variant A was purified 4000-fold. 3. Variant B, which comes off the Sephadex G-200 column before variant A, is the electrophoretically slower-moving species on starch gel and is quite heterogeneous. 4. Purified variant A was fairly homogeneous on the basis of electrophoretic studies on starch gel and Sephadex gel, ultracentrifugation and immunodiffusion. 5. The respective molecular weights for variants A and B were 70000 and over 200000 on the basis of sucrose-density-gradient ultracentrifugation. Variant A exhibited a sedimentation coefficient of 4·2s. 6. Crystalline variant B could be converted into fast-moving variant A and vice versa. 7. Kinetic studies indicated no difference between the two variants. These include linear rates of hydrolysis, pH optimum, Michaelis constants and uncompetitive stereospecific l-phenylalanine inhibition. 8. The amino acid compositions of variants A and B and of placental albumin were determined. ImagesFig. 3.Fig. 5.Fig. 7.Fig. 8.Fig. 9. PMID:4970595

  15. ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS : II. THE INFLUENCE OF SUCROSE, GLYCEROL, AND UREA SOLUTIONS ON THE PHYSICAL NATURE OF VACCINE VIRUS.

    PubMed

    Smadel, J E; Pickels, E G; Shedlovsky, T

    1938-09-30

    ULTRACENTRIFUGAL STUDIES OF THE CL DERMAL STRAIN OF VACCINE VIRUS WARRANT THE FOLLOWING CONCLUSIONS: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest with sucrose and most marked with urea. The normal rate of sedimentation of Paschen bodies may be restored by resuspending them in dilute buffer solution. 2. The density of elementary bodies of vaccinia suspended in dilute buffer solutions is estimated to be 1.16 gm. per cc. Higher values for the density are found if the particles are suspended in solutions containing sucrose, glycerol, or urea. In 53 per cent sucrose, for example, the density is 1.25 gm. per cc. 3. Paschen bodies appear to be quite permeable to water and urea, less so to glycerol, and only slightly, if at all, to sucrose. 4. The increased density of the elementary bodies of vaccinia in sucrose solutions may be accounted for by an osmotic extraction of water from the particles. On this basis the water which can be thus extracted corresponds to at least a third of the original volume of the particles.

  16. Quantitation of pyrimidine dimer contents of nonradioactive deoxyribonucleic acid by electrophoresis in alkaline agarose gels

    SciTech Connect

    Sutherland, B.M.; Shih, A.G.

    1983-02-15

    We have developed a method of quantitating the pyrimidine dimer content of nonradioactive DNAs. DNA samples are treated with the UV-endonuclease from Micrococcus luteus and then separated according to molecular weight by electrophoresis on alkaline agarose gels. From their migration relative to known molecular weight standards, their median molecular weight and thus the number of dimers per DNA molecule in each sample can be calculated. Results of action spectra for dimer formation in T7 bacteriophage measured by this method agree well with action spectra for T7 killing. In addition, the method gives dimer yields in good agreement with those obtained by others using alkaline sucrose gradient sedimentation.

  17. PCR Primers for identification of high sucrose Saccharum genotypes.

    PubMed

    Vinayak, Vandana; Dhawan, Ashok K; Gupta, V K

    2010-01-01

    The progeny of a cross between high sucrose sugarcane clone S. officinarum 'Gungera' and a low sucrose clone S. spontaneum 'SES 603' resulted in interspecific hybrids that were named as ISH-1 to ISH-29 and graded on the basis of sucrose content. Hybrids ISH-1, ISH-5, ISH-17 and ISH-23 were selected as very high sucrose (65 to 100 mg/g tissue) genotypes, whereas ISH-10, ISH-11, ISH-12 and ISH-25 were very low sucrose (2 to 25 mg/g tissue) genotypes. DNA from leaves of both the parent clones, as also the progeny hybrids, was amplified using selected primers, in order to identify markers for sucrose content. Ten specific primers were examined: primers 'A' and 'B' that detect polymorphism in promoter region of sucrose synthase-2 gene; primers AI, SS and SPS that were designed on the basis of nucleotide sequences of genes for acid invertase, sucrose synthase and sucrose phosphate synthase enzymes, respectively and primers MSSCIR43, MSSCIRI, SMC226CG, SMC1039CG and SCB07 selected for relation to sucrose accumulation process. DNA products specific to low or high sucrose clones were identified. Primer 'A' and AI amplified DNA products of size 230 and 500 bp, respectively only in high sucrose genotypes ('Gungera', ISH-1, ISH-5, ISH-17 and ISH-23), while primer SMC226CG generated a DNA product of size 920 bp only in low sucrose genotypes ('SES 603', ISH-10, ISH-11, ISH-12 and ISH-25). Ten random decamer primers were also examined, but their products did not show relationship to sucrose content of genotypes.

  18. Alkaline fuel cells for prime power and energy storage

    NASA Astrophysics Data System (ADS)

    Stedman, J. K.

    Alkaline fuel cell technology and its application to future space missions requiring high power and energy storage are discussed. Energy densities exceeding 100 watthours per pound and power densities approaching 0.5 pounds per kilowatt are calculated for advanced systems. Materials research to allow reversible operation of cells for energy storage and higher temperature operation for peaking power is warranted.

  19. Sucrose secreted by the engineered cyanobacterium and its fermentability

    NASA Astrophysics Data System (ADS)

    Duan, Yangkai; Luo, Quan; Liang, Feiyan; Lu, Xuefeng

    2016-10-01

    The unicellular cyanobacterium, Synechococcus elongatus PCC 7942 (Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps (encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and cscB (encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing cscB only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.

  20. Evolution of Plant Sucrose Uptake Transporters

    PubMed Central

    Reinders, Anke; Sivitz, Alicia B.; Ward, John M.

    2012-01-01

    In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were not found in the chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean algae Chlorokybus atmosphyticus contains a SUT homolog (CaSUT1) and phylogenetic analysis indicated that it is basal to all other streptophyte SUTs analyzed. SUTs are present in both red algae and S. pombe but they are less related to plant SUTs than CaSUT1. Both Selaginella and Physcomitrella encode type II and III SUTs suggesting that both plasma membrane and vacuolar sucrose transporter activities were present in early land plants. It is likely that SUT transporters are important for scavenging sucrose from the environment and intracellular compartments in charophyte and non-vascular plants. Type I SUTs were only found in eudicots and we conclude that they evolved from type III SUTs, possibly through loss of a vacuolar targeting sequence. Eudicots utilize type I SUTs for phloem (vascular tissue) loading while monocots use type II SUTs for phloem loading. We show that HvSUT1 from barley, a type II SUT, reverted the growth defect of the Arabidopsis atsuc2 (type I) mutant. This indicates that type I and II SUTs evolved similar (and interchangeable) phloem loading transporter capabilities independently. PMID:22639641

  1. Comprehensive Mutational Analysis of Sucrose-Metabolizing Pathways in Streptococcus mutans Reveals Novel Roles for the Sucrose Phosphotransferase System Permease

    PubMed Central

    Zeng, Lin

    2013-01-01

    Sucrose is perhaps the most efficient carbohydrate for the promotion of dental caries in humans, and the primary caries pathogen Streptococcus mutans encodes multiple enzymes involved in the metabolism of this disaccharide. Here, we engineered a series of mutants lacking individual or combinations of sucrolytic pathways to understand the control of sucrose catabolism and to determine whether as-yet-undisclosed pathways for sucrose utilization were present in S. mutans. Growth phenotypes indicated that gtfBCD (encoding glucan exopolysaccharide synthases), ftf (encoding the fructan exopolysaccharide synthase), and the scrAB pathway (sugar-phosphotransferase system [PTS] permease and sucrose-6-PO4 hydrolase) constitute the majority of the sucrose-catabolizing activity; however, mutations in any one of these genes alone did not affect planktonic growth on sucrose. The multiple-sugar metabolism pathway (msm) contributed minimally to growth on sucrose. Notably, a mutant lacking gtfBC, which cannot produce water-insoluble glucan, displayed improved planktonic growth on sucrose. Meanwhile, loss of scrA led to growth stimulation on fructooligosaccharides, due in large part to increased expression of the fruAB (fructanase) operon. Using the LevQRST four-component signal transduction system as a model for carbohydrate-dependent gene expression in strains lacking extracellular sucrases, a PlevD-cat (EIIALev) reporter was activated by pulsing with sucrose. Interestingly, ScrA was required for activation of levD expression by sucrose through components of the LevQRST complex, but not for activation by the cognate LevQRST sugars fructose or mannose. Sucrose-dependent catabolite repression was also evident in strains containing an intact sucrose PTS. Collectively, these results reveal a novel regulatory circuitry for the control of sucrose catabolism, with a central role for ScrA. PMID:23222725

  2. Comprehensive mutational analysis of sucrose-metabolizing pathways in Streptococcus mutans reveals novel roles for the sucrose phosphotransferase system permease.

    PubMed

    Zeng, Lin; Burne, Robert A

    2013-02-01

    Sucrose is perhaps the most efficient carbohydrate for the promotion of dental caries in humans, and the primary caries pathogen Streptococcus mutans encodes multiple enzymes involved in the metabolism of this disaccharide. Here, we engineered a series of mutants lacking individual or combinations of sucrolytic pathways to understand the control of sucrose catabolism and to determine whether as-yet-undisclosed pathways for sucrose utilization were present in S. mutans. Growth phenotypes indicated that gtfBCD (encoding glucan exopolysaccharide synthases), ftf (encoding the fructan exopolysaccharide synthase), and the scrAB pathway (sugar-phosphotransferase system [PTS] permease and sucrose-6-PO(4) hydrolase) constitute the majority of the sucrose-catabolizing activity; however, mutations in any one of these genes alone did not affect planktonic growth on sucrose. The multiple-sugar metabolism pathway (msm) contributed minimally to growth on sucrose. Notably, a mutant lacking gtfBC, which cannot produce water-insoluble glucan, displayed improved planktonic growth on sucrose. Meanwhile, loss of scrA led to growth stimulation on fructooligosaccharides, due in large part to increased expression of the fruAB (fructanase) operon. Using the LevQRST four-component signal transduction system as a model for carbohydrate-dependent gene expression in strains lacking extracellular sucrases, a PlevD-cat (EIIA(Lev)) reporter was activated by pulsing with sucrose. Interestingly, ScrA was required for activation of levD expression by sucrose through components of the LevQRST complex, but not for activation by the cognate LevQRST sugars fructose or mannose. Sucrose-dependent catabolite repression was also evident in strains containing an intact sucrose PTS. Collectively, these results reveal a novel regulatory circuitry for the control of sucrose catabolism, with a central role for ScrA.

  3. Quantitation of radiation-, chemical-, or enzyme-induced single strand breaks in nonradioactive DNA by alkaline gel electrophoresis: application to pyrimidine dimers

    SciTech Connect

    Freeman, S.E.; Blackett, A.D.; Monteleone, D.C.; Setlow, R.B.; Sutherland, B.M.; Sutherland, J.C.

    1986-10-01

    The authors have developed an alkaline agarose gel method for quantitating single strand breaks in nanogram quantities of nonradioactive DNA. After electrophoresis together with molecular length standards, the DNA is neutralized, stained with ethidium bromide, photographed, and the density profiles recorded with a computer controller scanner. The medium lengths, number average molecular lengths, and length average molecular lengths of the DNAs can be computed by using the mobilities of the molecular length standards. The frequency of single strand breaks can then be determined by comparison of the corresponding average molecular lengths of DNAs treated and not treated with single stand break-inducing agents (radiation, chemicals, or lesion-specific endonuclease). Single stand break yields (induced at pyrimidine dimer sites in uv-irradiated human fibroblasts DNA by the dimer-specific endonuclease from Micrococcus luteus) from our method agree with values obtained for the same DNAs from alkaline sucrose gradient analysis. The method has been used to determined pyrimidine dimer yields in DNA from biopsies of human skin irradiated in situ. It will be especially useful in determining the frequency of single strand breaks (or lesions convertible to single stand breaks by specific cleaving reagents or enzymes) in small quantities of DNA from cells or tissues not amendable to radioactive labeling.

  4. Effect of salt on the response of birds to sucrose

    USGS Publications Warehouse

    Rogers, J.G.; Maller, O.

    1973-01-01

    The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

  5. Enhancing fermentative hydrogen production from sucrose.

    PubMed

    Perera, Karnayakage Rasika J; Nirmalakhandan, Nagamany

    2010-12-01

    This study evaluated the hypothesis that fermentative hydrogen production from organic-rich feedstock could be enhanced by supplementing with waste materials such as cattle manure that could provide nutritional needs, buffering capacity, and native hydrogen-producing organisms. This hypothesis was tested in batch reactors fed with sucrose blended with cattle manure run at 25 degrees C without any nutrient supplements, pH adjustments, buffering, or gas-sparging. Hydrogen production rates in these reactors ranged 16-30 mL H(2)/g DeltaCOD-day, while hydrogen content in the biogases ranged 50-59%. Compared to literature studies conducted at higher temperatures, hydrogen yields found in this study at 25 degrees C were higher in the range of 3.8-4.7 mol H(2)/mol sucrose added, with higher positive net energy yields (>14 kJ/L). This study demonstrated that cattle manure as a supplement could not only provide hydrogen-producing seed, nutritional needs, and buffering capacity, but also increase hydrogen yield by approximately 10%, improving the economic viability of fermentative biohydrogen production from sugary wastes.

  6. Sucrose-mediated giant cell formation in the genus Neisseria.

    PubMed

    Johnson, K G; McDonald, I J

    1976-03-01

    Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.

  7. Improving the alkaline stability of imidazolium cations by substitution.

    PubMed

    Dong, Huilong; Gu, Fenglou; Li, Min; Lin, Bencai; Si, Zhihong; Hou, Tingjun; Yan, Feng; Lee, Shuit-Tong; Li, Youyong

    2014-10-06

    Imidazolium cations are promising candidates for preparing anion-exchange membranes because of their good alkaline stability. Substitution of imidazolium cations is an efficient way to improve their alkaline stability. By combining density functional theory calculations with experimental results, it is found that the LUMO energy correlates with the alkaline stability of imidazolium cations. The results indicate that alkyl groups are the most suitable substituents for the N3 position of imidazolium cations, and the LUMO energies of alkyl-substituted imidazolium cations depend on the electron-donating effect and the hyperconjugation effect. Comparing 1,2-dimethylimidazolium cations (1,2-DMIm+) and 1,3-dimethylimidazolium cations (1,3-DMIm+) with the same substituents reveals that the hyperconjugation effect is more significant in influencing the LUMO energy of 1,3-DMIms. This investigation reveals that LUMO energy is a helpful aid in predicting the alkaline stability of imidazolium cations.

  8. Sucrose transport and phloem unloading in stem of Vicia faba: possible involvement of a sucrose carrier and osmotic regulation

    SciTech Connect

    Aloni, B.; Wyse, R.E.; Griffith, S.

    1986-06-01

    After pulse labeling of a source leaf with /sup 14/CO/sub 2/, stem sections of Vicia faba plants were cut and the efflux characteristics of /sup 14/C-labeled sugars into various buffered solutions were determined. Radiolabeled sucrose was shown to remain localized in the phloem and adjacent phloem parenchyma tissues after a 2-hour chase. Therefore, sucrose leakage from stem segments prepared following a 75-minute chase period was assumed to be characteristic of phloem unloading. The efflux of /sup 14/C assimilates from the phloem was enhanced by 1 millimolar p-chloromercuribenzene sulfonic acid (PCMBS) and by 5 micromolar carbonyl cyanide m-chlorophenly hydrazone (CCCP). However, PCMBS inhibited and CCCP enhanced general leakage of nonradioactive sugars from the stem segments. Sucrose at concentrations of 50 millimolar in the free space increased efflux of (/sup 14/C)sucrose, presumably through an exchange mechanism. This exchange was inhibited by PCMBS and abolished by 0.2 molar mannitol. Increasing the osmotic concentration of the efflux medium with mannitol reduced (/sup 14/C)sucrose efflux. However, this inhibition seems not to be specific to sucrose unloading since leakage of total sugars, nonlabeled sucrose, glucose, and amino acids from the bulk of the tissue was reduced in a similar manner. The data suggest that phloem unloading in cut stem segments is consistent with passive efflux of sucrose from the phloem to the apoplast and that sucrose exchange via a membrane carrier may be involved.

  9. Functionality of Inulin as a Sucrose Replacer in Cookie Baking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

  10. Oral sucrose and pain relief for preterm infants.

    PubMed

    Mitchell, Anita; Waltman, Patricia A

    2003-06-01

    The frequency of painful procedures performed on preterm infants in the neonatal intensive care unit (NICU) presents a challenge to nurses who are attempting to provide effective pain relief, and to the infants themselves who may suffer adverse consequences in response to repeated painful procedures. One new pain relief intervention under study is the administration of oral sucrose, which may activate endogenous opioid systems within the body. Studies with preterm infants that have examined the use of oral sucrose as an analgesic during heelsticks and venipunctures have shown that sucrose is effective in reducing pain. Sucrose may also be combined with nonnutritive sucking to provide significant pain relief. The use of oral sucrose is now recommended with a wide range of painful procedures in the NICU. Promising results have been observed in studies with both term and preterm infants, but less research has occurred with preterm infants. Additional research is warranted to determine the most effective approaches for the administration of sucrose, to examine the effectiveness of sucrose with additional types of painful procedures, and to examine the effects of long-term repeated use of sucrose.

  11. Comparative sucrose responsiveness in Apis mellifera and A. cerana foragers.

    PubMed

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y; Miao, Xiaoqing

    2013-01-01

    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources.

  12. 21 CFR 172.833 - Sucrose acetate isobutyrate (SAIB).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Section 172.833 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.833 Sucrose acetate isobutyrate (SAIB). Sucrose...

  13. Sucrose and Saccharomyces cerevisiae: a relationship most sweet.

    PubMed

    Marques, Wesley Leoricy; Raghavendran, Vijayendran; Stambuk, Boris Ugarte; Gombert, Andreas Karoly

    2016-02-01

    Sucrose is an abundant, readily available and inexpensive substrate for industrial biotechnology processes and its use is demonstrated with much success in the production of fuel ethanol in Brazil. Saccharomyces cerevisiae, which naturally evolved to efficiently consume sugars such as sucrose, is one of the most important cell factories due to its robustness, stress tolerance, genetic accessibility, simple nutrient requirements and long history as an industrial workhorse. This minireview is focused on sucrose metabolism in S. cerevisiae, a rather unexplored subject in the scientific literature. An analysis of sucrose availability in nature and yeast sugar metabolism was performed, in order to understand the molecular background that makes S. cerevisiae consume this sugar efficiently. A historical overview on the use of sucrose and S. cerevisiae by humans is also presented considering sugarcane and sugarbeet as the main sources of this carbohydrate. Physiological aspects of sucrose consumption are compared with those concerning other economically relevant sugars. Also, metabolic engineering efforts to alter sucrose catabolism are presented in a chronological manner. In spite of its extensive use in yeast-based industries, a lot of basic and applied research on sucrose metabolism is imperative, mainly in fields such as genetics, physiology and metabolic engineering.

  14. Alkaline battery, separator therefore

    NASA Technical Reports Server (NTRS)

    Schmidt, George F. (Inventor)

    1980-01-01

    An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition. When the salt is formed, it expands the polymeric chains of the binder to provide a film coating substantially permeable to electrolyte ion transfer but relatively impermeable to electrode ion transfer during use.

  15. Ameliorative Effect of Hydroethanolic Leaf Extract of Byrsocarpus coccineus in Alcohol- and Sucrose-Induced Hypertension in Rats

    PubMed Central

    Akindele, Abidemi J.; Iyamu, Endurance A.; Dutt, Prabhu; Satti, Naresh K.; Adeyemi, Olufunmilayo O.

    2014-01-01

    Hypertension remains a major health problem worldwide considering the prevalence of morbidity and mortality. Plants remain a reliable source of efficacious and better tolerated drugs and botanicals. This study was designed to investigate the effect of the chemo-profiled hydroethanolic leaf extract of Byrsocarpus coccineus in ethanol- and sucrose-induced hypertension. Groups of rats were treated orally (p.o.) with distilled water (10 ml/kg), ethanol (35%; 3 g/kg), sucrose (5-7%), and B. coccineus (100, 200, and 400 mg/kg), and nifedipine together with ethanol and sucrose separately for 8 weeks. At the end of the treatment period, blood pressure and heart rate of rats were determined. Blood was collected for serum biochemical parameters and lipid profile assessment, and the liver, aorta, kidney, and heart were harvested for estimation of in vivo antioxidants and malondialdehyde (MDA). Results obtained in this study showed that B. coccineus at the various doses administered reduced the systolic, diastolic, and arterial blood pressure elevated by ethanol and sucrose. Also, the extract reversed the reduction in catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) induced by ethanol and sucrose. The level of MDA was reduced compared to the ethanol- and sucrose-induced hypertensive group. With respect to lipid profile, administration of B. coccineus at the various doses reduced the levels of triglycerides, low-density lipoprotein (LDL), cholesterol, and atherogenic indices, compared to the ethanol and sucrose groups. In conclusion the hydroethanolic leaf extract of B. coccineus exerted significant antihypertensive effect and this is probably related to the antioxidant property and improvement of lipid profile observed in this study. PMID:25161923

  16. Sucrose behenate as a crystallization enhancer for soft fats.

    PubMed

    Domingues, Maria Aliciane Fontenele; da Silva, Thaís Lomonaco Teodoro; Ribeiro, Ana Paula Badan; Chiu, Ming Chih; Gonçalves, Lireny Aparecida Guaraldo

    2016-02-01

    The addition of sucrose behenate for the modification of the physical properties of soft fats, such as soybean oil-based interesterified fat, refined palm oil, and palm mid fraction was studied. The addition of sucrose behenate was verified to affect the crystalline network of fats, changing the hardness and solids profile. The isothermal crystallization behaviors of the fat blends with 1% sucrose behenate were analyzed at 20 and 25 °C. Temperature had a greater effect on the speed of crystallization (k) than the presence of the emulsifier. Sucrose behenate did, however, influence the crystallization mechanism, with changes observed in the Avrami exponent (n). These changes were also observed in the microstructure of the fats. Changes in the polymorphic behavior were observed with the addition of sucrose behenate, such as a possible delay in the α → β transition for interesterified fat, and the initial formation of the β polymorph in palm oil.

  17. A Diet High in Saturated Fat and Sucrose Alters Glucoregulation and Induces Aortic Fatty Streaks in New Zealand White Rabbits

    PubMed Central

    Yuan, Zhonghua; Wang, Zongbao; Yang, Baotang; Yang, Yongzong

    2002-01-01

    A new and convenient animal model for studying peripheral vascular and coronary artery disease in diabetes was established in this study. Male New Zealand White rabbits weighing approximately 2 kg were divided into 2 groups: a normal control group fed standard laboratory chow and a diabetogenic diet–fed group received a high-fat/high-sucrose diet. The high-fat/high-sucrose diet (contained 10% lard and 37% sucrose) feeding was maintained for 6 months. Plasma total cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, superoxide dismutase, nitric oxide, nitric oxide synthase, insulin, and glucose were quantitated at monthly or bimonthly intervals. The aortic fatty streak lesions were quantified following lipid staining with Sudan IV. The aortic samples were observed by electron microscopy. High plasma triglyceride and glucose concentrations were induced. At the end of 6 months, the aortic fatty streak lesions were present in the animals' vascular specimens. As far as we know, this is the first report that demonstrates that New Zealand White rabbits can develop obvious aortic fatty streaks by feeding a high-fat/high-sucrose diet. Our results suggest that NewZealand White rabbits fed a high-fat/high-sucrose diet would provide a convenient model for studying peripheral vascular and coronary artery disease in diabetes. PMID:12458659

  18. 78 FR 66743 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose; Availability

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... Recommendations for Iron Sucrose; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY... entitled ``Bioequivalence Recommendations for Iron Sucrose.'' The recommendations provide specific guidance... iron sucrose injection. The draft guidance is a revised version of a previously issued draft...

  19. The sucrose-trehalose 6-phosphate (Tre6P) nexus: specificity and mechanisms of sucrose signalling by Tre6P.

    PubMed

    Yadav, Umesh Prasad; Ivakov, Alexander; Feil, Regina; Duan, Guang You; Walther, Dirk; Giavalisco, Patrick; Piques, Maria; Carillo, Petronia; Hubberten, Hans-Michael; Stitt, Mark; Lunn, John Edward

    2014-03-01

    Trehalose 6-phosphate (Tre6P), the intermediate of trehalose biosynthesis, has a profound influence on plant metabolism, growth, and development. It has been proposed that Tre6P acts as a signal of sugar availability and is possibly specific for sucrose status. Short-term sugar-feeding experiments were carried out with carbon-starved Arabidopsis thaliana seedlings grown in axenic shaking liquid cultures. Tre6P increased when seedlings were exogenously supplied with sucrose, or with hexoses that can be metabolized to sucrose, such as glucose and fructose. Conditional correlation analysis and inhibitor experiments indicated that the hexose-induced increase in Tre6P was an indirect response dependent on conversion of the hexose sugars to sucrose. Tre6P content was affected by changes in nitrogen status, but this response was also attributable to parallel changes in sucrose. The sucrose-induced rise in Tre6P was unaffected by cordycepin but almost completely blocked by cycloheximide, indicating that de novo protein synthesis is necessary for the response. There was a strong correlation between Tre6P and sucrose even in lines that constitutively express heterologous trehalose-phosphate synthase or trehalose-phosphate phosphatase, although the Tre6P:sucrose ratio was shifted higher or lower, respectively. It is proposed that the Tre6P:sucrose ratio is a critical parameter for the plant and forms part of a homeostatic mechanism to maintain sucrose levels within a range that is appropriate for the cell type and developmental stage of the plant.

  20. Alkaline regenerative fuel cell systems for energy storage

    SciTech Connect

    Schubert, F.H.; Reid, M.A.; Martin, R.E.

    1981-01-01

    This paper presents the results of a preliminary design study of a Regenerative Fuel Cell Energy Storage system for application to future low-earth orbit space missions. This high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. 11 refs.

  1. Cariogenic Potential of Sucrose Associated with Maltodextrin on Dental Enamel.

    PubMed

    Rezende, Gabriela; Arthur, Rodrigo A; Grando, Debora; Hashizume, Lina N

    2017-01-26

    Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltodextrin could increase the cariogenic potential of sucrose. This was an in situ, randomized, crossover, split-mouth, and double-blind study. Volunteers wore palatal appliances containing bovine enamel blocks for 2 periods of 14 days. They dripped the following solutions on the enamel blocks 8 times per day: deionized distilled water (DDW), maltodextrin (M), sucrose + maltodextrin (S+M), or sucrose (S). At the end of each experimental period, biofilms were collected and analyzed for microbiological (mutans streptococci, lactobacilli, and total microorganisms counts) and biochemical (calcium, inorganic phosphate, fluoride, and insoluble extracellular polysaccharides concentrations) compositions. The enamel demineralization was assessed by microhardness. Treatments S and S+M resulted in a lower inorganic composition and higher concentration of insoluble extracellular polysaccharides in the biofilms, and higher enamel mineral loss compared to DDW and M. It can be concluded that the cariogenic potential of sucrose is not changed when this carbohydrate is associated with maltodextrin (dextrose equivalent 13-17).

  2. Viscous properties of microparticulated dairy proteins and sucrose.

    PubMed

    Onwulata, C I; Konstance, R P; Tomasula, P M

    2002-07-01

    Slurries of whey protein concentrate (WPC) or sodium caseinate (Na-CN) mixed with sucrose (36% T.S.) were subjected to microparticulation by a high shear homogenizer operated at 27,000 rpm for 2, 4, and 6 min to facilitate gel formation. After microparticulation treatment, the milk protein and sucrose slurries were evaporated at 85 degrees C for 60 min under a partial vacuum (20 to 45 mm of Hg) to form composite gels. Particle sizes and viscoelastic properties were determined before microparticulation treatment. Microparticulation reduced the particle size of WPC-sucrose slurries from an average size of 330 to 188 nm after 4 min and NaCN-sucrose slurries from 270 to 35 nm after 2 min. The WPC-sucrose composites were gel-like, but NaCN-sucrose composites did not gel. Viscoelastic properties of heated WPC-sucrose composites were liquid-like, exhibiting significant reduction in storage modulus and complex viscosity. Microparticulation reduced particle sizes, which resulted in softer gels as time of shearing increased.

  3. Functional Relationship between Sucrose and a Cariogenic Biofilm Formation

    PubMed Central

    Cai, Jian-Na; Jung, Ji-Eun; Dang, Minh-Huy; Kim, Mi-Ah; Yi, Ho-Keun; Jeon, Jae-Gyu

    2016-01-01

    Sucrose is an important dietary factor in cariogenic biofilm formation and subsequent initiation of dental caries. This study investigated the functional relationships between sucrose concentration and Streptococcus mutans adherence and biofilm formation. Changes in morphological characteristics of the biofilms with increasing sucrose concentration were also evaluated. S. mutans biofilms were formed on saliva-coated hydroxyapatite discs in culture medium containing 0, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, or 40% (w/v) sucrose. The adherence (in 4-hour biofilms) and biofilm composition (in 46-hour biofilms) of the biofilms were analyzed using microbiological, biochemical, laser scanning confocal fluorescence microscopic, and scanning electron microscopic methods. To determine the relationships, 2nd order polynomial curve fitting was performed. In this study, the influence of sucrose on bacterial adhesion, biofilm composition (dry weight, bacterial counts, and water-insoluble extracellular polysaccharide (EPS) content), and acidogenicity followed a 2nd order polynomial curve with concentration dependence, and the maximum effective concentrations (MECs) of sucrose ranged from 0.45 to 2.4%. The bacterial and EPS bio-volume and thickness in the biofilms also gradually increased and then decreased as sucrose concentration increased. Furthermore, the size and shape of the micro-colonies of the biofilms depended on the sucrose concentration. Around the MECs, the micro-colonies were bigger and more homogeneous than those at 0 and 40%, and were surrounded by enough EPSs to support their structure. These results suggest that the relationship between sucrose concentration and cariogenic biofilm formation in the oral cavity could be described by a functional relationship. PMID:27275603

  4. The alkaline and alkaline-carbonatite magmatism from Southern Brazil

    NASA Astrophysics Data System (ADS)

    Ruberti, E.; Gomes, C. D. B.; Comin-Chiaramonti, P.

    2015-12-01

    Early to Late Cretaceous lasting to Paleocene alkaline magmatism from southern Brazil is found associated with major extensional structural features in and around the Paraná Basin and grouped into various provinces on the basis of several data. Magmatism is variable in size, mode of occurrence and composition. The alkaline rocks are dominantly potassic, a few occurrences showing sodic affinity. The more abundant silicate rocks are evolved undersaturated to saturated in silica syenites, displaying large variation in igneous forms. Less evolved types are restricted to subvolcanic environments and outcrops of effusive suites occur rarely. Cumulatic mafic and ultramafic rock types are very common, particularly in the alkali-carbonatitic complexes. Carbonatite bodies are represented by Ca-carbonatites and Mg-carbonatites and more scarcely by Fe-carbonatites. Available radiometric ages for the alkaline rocks fit on three main chronological groups: around 130 Ma, subcoveal with the Early Cretaceous flood tholeiites of the Paraná Basin, 100-110 Ma and 80-90 Ma (Late Cretaceous). The alkaline magmatism also extends into Paleocene times, as indicated by ages from some volcanic lavas. Geochemically, alkaline potassic and sodic rock types are distinguished by their negative and positive Nb-Ta anomalies, respectively. Negative spikes in Nb-Ta are also a feature common to the associated tholeiitic rocks. Sr-Nd-Pb systematics confirm the contribution of both HIMU and EMI mantle components in the formation of the alkaline rocks. Notably, Early and Late Cretaceous carbonatites have the same isotopic Sr-Nd initial ratios of the associated alkaline rocks. C-O isotopic Sr-Nd isotopic ratios indicate typical mantle signature for some carbonatites and the influence of post-magmatic processes in others. Immiscibility of liquids of phonolitic composition, derived from mafic alkaline parental magmas, has been responsible for the origin of the carbonatites. Close association of alkaline

  5. Microscopic calculation of the compressibility of hydrides of alkaline metals

    NASA Astrophysics Data System (ADS)

    Krymov, V. A.; Fuks, D. L.

    1987-09-01

    Isotherms have been constructed and compressibilities and sound velocities have been calculated for the hydrides of alkaline metals on the basis of the functional theory of the local electron density, within the framework of the pseudopotential method. The expression obtained for the electron density distribution allows one to perform the analysis of the character of the binding forces and to determine the dependence of the degree of ionization on pressure in these compounds.

  6. Structural determinants of product specificity of sucrose isomerases.

    PubMed

    Ravaud, Stéphanie; Robert, Xavier; Watzlawick, Hildegard; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2009-06-18

    The healthy sweetener isomaltulose is industrially produced from the conversion of sucrose by the sucrose isomerase SmuA from Protaminobacter rubrum. Crystal structures of SmuA in native and deoxynojirimycin complexed forms completed with modeling studies unravel the characteristics of the isomaltulose synthases catalytic pocket and their substrate binding mode. Comparison with the trehalulose synthase MutB highlights the role of Arg(298) and Arg(306) active site residues and surface charges in controlling product specificity of sucrose isomerases (isomaltulose versus trehalulose). The results provide a rationale for the specific design of optimized enzymes.

  7. Honey promotes lower weight gain, adiposity, and triglycerides than sucrose in rats.

    PubMed

    Nemoseck, Tricia M; Carmody, Erin G; Furchner-Evanson, Allison; Gleason, Marsa; Li, Amy; Potter, Hayley; Rezende, Lauren M; Lane, Kelly J; Kern, Mark

    2011-01-01

    Various dietary carbohydrates have been linked to obesity and altered adipose metabolism; however, the influences of honey vs common sweeteners have not been fully explored. We hypothesized that in comparison with sucrose, a honey-based diet would promote lower weight gain, adiposity, and related biomarkers (leptin, insulin, and adiponectin) as well as a better blood lipid profile. Thirty-six male Sprague-Dawley rats (228.1 ± 12.5 g) were equally divided by weight into 2 groups (n = 18) and provided free access to 1 of 2 diets of equal energy densities differing only in a portion of the carbohydrate. Diets contained 20% carbohydrate (by weight of total diet) from either clover honey or sucrose. After 33 days, epididymal fat pads were excised and weighed, and blood was collected for analyses of serum concentrations of lipids, glucose, and markers of adiposity and inflammation. Body weight gain was 14.7% lower (P ≤ .05) for rats fed honey, corresponding to a 13.3% lower (P ≤ .05) consumption of food/energy, whereas food efficiency ratios were nearly identical. Epididymal fat weight was 20.1% lower (P ≤ .05) for rats fed honey. Serum concentrations of triglycerides and leptin were lower (P ≤ .05) by 29.6% and 21.6%, respectively, and non-high-density lipoprotein cholesterol was higher (P ≤ .05) by 16.8% for honey-fed rats. No significant differences in serum total cholesterol, high-density lipoprotein cholesterol, adiponectin, C-reactive protein, monocyte chemoattractant protein-1, glucose, or insulin were detected. These results suggest that in comparison with sucrose, honey may reduce weight gain and adiposity, presumably due to lower food intake, and promote lower serum triglycerides but higher non-high-density lipoprotein cholesterol concentrations.

  8. A reassessment of the role of sucrose synthase in the hypoxic sucrose-ethanol transition in Arabidopsis.

    PubMed

    Santaniello, Antonietta; Loreti, Elena; Gonzali, Silvia; Novi, Giacomo; Perata, Pierdomenico

    2014-10-01

    Plants under low-oxygen availability adapt their metabolism to compensate for the lower ATP production that arises from the limited respiratory activity in mitochondria. Anaerobic glycolysis requires continuous fuelling of carbon units, also provided from sucrose. The anaerobic catabolism of sucrose is thought to require the activity of sucrose synthase, being this enzymatic reaction more energetically favourable than that of invertase. The role of sucrose synthases (SUS) for aerobic sucrose catabolism in Arabidopsis has been recently questioned since SUS mutants fail to show altered phenotype or metabolic profile. In the present paper, we analysed the role of SUS1 and SUS4, both induced by low oxygen, in plant survival and ethanol production. The results showed that mutants lacking both SUS were as tolerant to low oxygen as the wild type in most of the experimental conditions tested. Only under conditions of limiting sugar availability the requirement of SUS1 and SUS4 for ethanol production was evident, although partly compensated by invertase activities, as revealed by the use of a double mutant lacking the two major cytosolic invertases. We conclude that, contrary to general belief, the sucrose synthase pathway is not the preferential route for sucrose metabolism under hypoxia.

  9. Sucrose substitutes and their role in caries prevention.

    PubMed

    Matsukubo, Takashi; Takazoe, Ichiro

    2006-06-01

    Many non- or low-cariogenic sucrose substitutes are currently available and are found as ingredients of a variety of candy, chewing gum, and drinks. Recently the role of sugar alcohols in promoting remineralisation of enamel has attracted much attention. Thus, the dental profession needs to understand the general characteristics and features of sugar substitutes to provide advice on oral health to patients as well as the general public. There are two critical requirements for sucrose substitutes, namely, being nutritionally appropriate and not being detrimental to the overall general health of the individual. The use of a greater variety of confectionary containing sucrose substitutes and the development of new substitutes with high nutritional value are essential in the battle against caries. In this paper we review in detail the characteristics of sucrose substitutes currently in use, their role in caries prevention and promotion of oral health.

  10. New sucrose esters from the fruits of Physalis solanaceus.

    PubMed

    Pérez-Castorena, Ana-Lidia; Luna, Minerva; Martínez, Mahinda; Maldonado, Emma

    2012-05-01

    Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR.

  11. Sucrose Improves Insecticide Activity Against Drosophila suzukii (Diptera: Drosophilidae).

    PubMed

    Cowles, Richard S; Rodriguez-Saona, Cesar; Holdcraft, Robert; Loeb, Gregory M; Elsensohn, Johanna E; Hesler, Steven P

    2015-04-01

    The addition of sucrose to insecticides targeting spotted wing drosophila, Drosophila suzukii (Matsumura), enhanced lethality in laboratory, semifield, and field tests. In the laboratory, 0.1% sucrose added to a spray solution enhanced spotted wing drosophila feeding. Flies died 120 min earlier when exposed to spinosad residues at label rates enhanced with sucrose. Added sucrose reduced the LC50 for dried acetamiprid residues from 82 to 41 ppm in the spray solution. Laboratory bioassays of spotted wing drosophila mortality followed exposure to grape and blueberry foliage and/or fruit sprayed and aged in the field. On grape foliage, the addition of 2.4 g/liter of sugar with insecticide sprays resulted in an 11 and 6% increase of spotted wing drosophila mortality at 1 and 2 d exposures to residues, respectively, averaged over seven insecticides with three concentrations. In a separate experiment, spinetoram and cyantraniliprole reduced by 95-100% the larval infestation of blueberries, relative to the untreated control, 7 d after application at labeled rates when applied with 1.2 g/liter sucrose in a spray mixture, irrespective of rainfall; without sucrose infestation was reduced by 46-91%. Adding sugar to the organically acceptable spinosyn, Entrust, reduced larval infestation of strawberries by >50% relative to without sugar for five of the six sample dates during a season-long field trial. In a small-plot field test with blueberries, weekly applications in alternating sprays of sucrose plus reduced-risk insecticides, spinetoram or acetamiprid, reduced larval infestation relative to the untreated control by 76%; alternating bifenthrin and phosmet (without sucrose) reduced infestation by 65%.

  12. Evolution of Sucrose Synthesis[w

    PubMed Central

    Lunn, John Edward

    2002-01-01

    Cyanobacteria and proteobacteria (purple bacteria) are the only prokaryotes known to synthesize sucrose (Suc). Suc-P synthase, Suc-phosphatase (SPP), and Suc synthase activities have previously been detected in several cyanobacteria, and genes coding for Suc-P synthase (sps) and Suc synthase (sus) have been cloned from Synechocystis sp. PCC 6803 and Anabaena (Nostoc) spp., respectively. An open reading frame in the Synechocystis genome encodes a predicted 27-kD polypeptide that shows homology to the maize (Zea mays) SPP. Heterologous expression of this putative spp gene in Escherichia coli, reported here, confirmed that this open reading frame encodes a functional SPP enzyme. The Synechocystis SPP is highly specific for Suc-6F-P (Km = 7.5 μm) and is Mg2+ dependent (Ka = 70 μm), with a specific activity of 46 μmol min−1 mg−1 protein. Like the maize SPP, the Synechocystis SPP belongs to the haloacid dehalogenase superfamily of phosphatases/hydrolases. Searches of sequenced microbial genomes revealed homologs of the Synechocystis sps gene in several other cyanobacteria (Nostoc punctiforme, Prochlorococcus marinus strains MED4 and MIT9313, and Synechococcus sp. WH8012), and in three proteobacteria (Acidithiobacillus ferrooxidans, Magnetococcus sp. MC1, and Nitrosomonas europaea). Homologs of the Synechocystis spp gene were found in Magnetococcus sp. MC1 and N. punctiforme, and of the Anabaena sus gene in N. punctiforme and N. europaea. From analysis of these sequences, it is suggested that Suc synthesis originated in the proteobacteria or a common ancestor of the proteobacteria and cyanobacteria. PMID:11950997

  13. Altered sucrose metabolism impacts plant biomass production and flower development.

    PubMed

    Coleman, Heather D; Beamish, Leigh; Reid, Anya; Park, Ji-Young; Mansfield, Shawn D

    2010-04-01

    Nicotiana tabacum (tobacco) was transformed with three genes involved in sucrose metabolism, UDP-glucose pyrophosphorylase (UGPase, EC 2.7.7.9), sucrose synthase (SuSy, EC 2.4.1.13) and sucrose phosphate synthase (SPS, EC 2.4.1.14). Plants harbouring the single transgenes were subsequently crossed to produce double and triple transgenic lines, including: 2 x 35S::UGPase x SPS, 4CL::UGPase x SPS, 2 x 35S::SuSy x SPS, 4CL::SuSy x SPS, 2 x 35S::UGPase x SuSy x SPS, and 4CL::UGPase x SuSy x SPS. The ultimate aim of the study was to examine whether it is possible to alter cellulose production through the manipulation of sucrose metabolism genes. While altering sucrose metabolism using UGPase, SuSy and SPS does not have an end effect on cellulose production, their simultaneous overexpression resulted in enhanced primary growth as seen in an increase in height growth, in some cases over 50%. Furthermore, the pyramiding strategy of simultaneously altering the expression of multiple genes in combination resulted in increased time to reproductive bud formation as well as altered flower morphology and foliar stipule formation in 4CL lines. Upregulation of these sucrose metabolism genes appears to directly impact primary growth and therefore biomass production in tobacco.

  14. Microbial sucrose isomerases: producing organisms, genes and enzymes.

    PubMed

    Goulter, Ken C; Hashimi, Saeed M; Birch, Robert G

    2012-01-05

    Sucrose isomerase (SI) activity is used industrially for the conversion of sucrose into isomers, particularly isomaltulose or trehalulose, which have properties advantageous over sucrose for some food uses. All of the known microbial SIs are TIM barrel proteins that convert sucrose without need for any cofactors, with varying kinetics and product specificities. The current analysis was undertaken to bridge key gaps between the information in patents and scientific publications about the microbes and enzymes useful for sucrose isomer production. This analysis shows that microbial SIs can be considered in 5 structural classes with corresponding functional distinctions that broadly align with the taxonomic differences between producing organisms. The most widely used bacterial strain for industrial production of isomaltulose, widely referred to as "Protaminobacter rubrum" CBS 574.77, is identified as Serratia plymuthica. The strain producing the most structurally divergent SI, with a high product specificity for trehalulose, widely referred to as "Pseudomonas mesoacidophila" MX-45, is identified as Rhizobium sp. Each tested SI-producer is shown to have a single SI gene and enzyme, so the properties reported previously for the isolated proteins can reasonably be associated with the products of the genes subsequently cloned from the same isolates and SI classes. Some natural isolates with potent SI activity do not catabolize the isomer under usual production conditions. The results indicate that their industrial potential may be further enhanced by selection for variants that do not catabolize the sucrose substrate.

  15. Waiting 2 minutes after sucrose administration—unnecessary?

    PubMed Central

    Meesters, Naomi; Simons, Sinno; van Rosmalen, Joost; Reiss, Irwin; van den Anker, John; van Dijk, Monique

    2017-01-01

    Background Worldwide, oral sucrose is standard of care in many neonatal intensive care units to relieve procedural pain in neonates. This study aims to determine if time interval between sucrose administration and heelstick correlates with pain scores. Methods Neonates were prospectively studied with variable time intervals and assessed with the Premature Infant Pain Profile-Revised (PIPP-R). Results 150 neonates were included with a median gestational age of 30+6 (IQR 27+6–33+2) weeks and a median time interval of 72 (IQR 39–115) seconds between sucrose administration and heelstick. In multiple regression analysis, this time interval was not significantly related to the PIPP-R (B=0.004, 95% CI −0.005 to 0.013, p=0.37). Providing non-nutritive sucking combined with sucrose was significantly related to lower PIPP-R scores (B=−3.50, 95% CI −4.7 to −2.3, p<0.001). Conclusions Our study suggests that there is no need to wait 2 min after sucrose administration before a painful procedure. Sucrose-induced non-nutritive sucking shows a fast pain-relieving effect in neonates. PMID:28157669

  16. Ethnic Variability in Glycemic Response to Sucrose and Isomaltulose.

    PubMed

    Tan, Wei Shuan Kimberly; Tan, Sze-Yen; Henry, Christiani Jeyakumar

    2017-04-01

    The aim of this study was to compare the glycemic response of Caucasians and Asians to two disaccharides of different glycemic index (GI), and to examine if ethnic groups that showed the largest glycemic response to sucrose would benefit the most when it is replaced with isomaltulose. Forty healthy participants (10 Chinese; 10 Malays; 10 Caucasians; and 10 Indians) consumed beverages containing 50 g of sucrose or isomaltulose on two separate occasions using a randomized crossover design. Capillary blood glucose was measured in a fasted state and at 15, 30, 45, 60, 90, and 120 min after beverage ingestion. Glycemic response to sucrose was significantly higher in Malays compared to Caucasians (p = 0.041), but did not differ between Caucasians vs. Chinese (p = 0.145) or vs. Indians (p = 0.661). When sucrose was replaced with isomaltulose, glycemic responses were significantly reduced in all ethnic groups, with the largest reduction in glycemic response being observed in Malays. Malays, who had the greatest glycemic response to sucrose, also showed the greatest improvement in glycemic response when sucrose was replaced with isomaltulose. This implies that Malays who are more susceptible to type 2 diabetes mellitus may benefit from strategies that replace high GI carbohydrate with lower GI alternatives to assist in glycemic control.

  17. Effect of starch on the cariogenic potential of sucrose.

    PubMed

    Ribeiro, Cecilia C C; Tabchoury, Cínthia P M; Del Bel Cury, Altair A; Tenuta, Livia M A; Rosalen, Pedro L; Cury, Jaime A

    2005-07-01

    Since in vitro and animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessed in situ the effects of this association applied in vitro on the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch+10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch+sucrose (P<0.05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P<0.05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose.

  18. Alkaline direct alcohol fuel cells using an anion exchange membrane

    NASA Astrophysics Data System (ADS)

    Matsuoka, Koji; Iriyama, Yasutoshi; Abe, Takeshi; Matsuoka, Masao; Ogumi, Zempachi

    Alkaline direct alcohol fuel cells using an OH-form anion exchange membrane and polyhydric alcohols were studied. A high open circuit voltage of ca. 800 mV was obtained for a cell using Pt-Ru/C (anode) and Pt/C (cathode) at 323 K, which was about 100-200 mV higher than that for a DMFC using Nafion ®. The maximum power densities were in the order of ethylene glycol > glycerol > methanol > erythritol > xylitol. Silver catalysts were used as a cathode catalyst to fabricate alkaline fuel cells, since silver catalyst is almost inactive in the oxidation of polyhydric alcohols. Alkaline direct ethylene glycol fuel cells using silver as a cathode catalyst gave excellent performance because higher concentrations of fuel could be supplied to the anode.

  19. Specialties of distributions of alkaline-earth metals in coal

    SciTech Connect

    Fan Jinchuan; Fan Minqiang

    1997-12-31

    Four different ranks of coal have been sampled and separated into different density fractions by Float-Sink. The contents of some trace elements in each density fraction has been analyzed by ICAP. The analyzed data show that the alkaline-earth metals (Be, Sr, and Ba) have their special distributions in coal: Be and Sr may exist in the form of organic matter. Ba often has the highest content in the middle density fraction (1.4--1.5). The relative relationship between ash (or sulfur) and the trace element in a certain type of coal was obtained by using linear regression approach. Results show that there is no significant correlation between the contents of ash or sulfur and those of Be, Sr, and Ba. On the other hand, the linear regression was done among the trace elements of 17 types of coal. The results also show that there is no significant correlation between ash or sulfur and alkaline-earth metals.

  20. On the identity of the last known stable radical in X-irradiated sucrose

    NASA Astrophysics Data System (ADS)

    Kusakovskij, Jevgenij; De Cooman, Hendrik; Sagstuen, Einar; Callens, Freddy; Vrielinck, Henk

    2017-04-01

    Identification of radiation-induced radicals in relatively simple molecules is a prerequisite for the understanding of reaction pathways of the radiation chemistry of complex systems. Sucrose presents an additional practical interest as a versatile radiation dosimetric system. In this work, we present a periodic density functional theory study aimed to identify the fourth stable radical species in this carbohydrate. The proposed model is a fragment suspended in the lattice by hydrogen bonds with an unpaired electron at the original C5' carbon of the fructose unit. It requires a double scission of the ring accompanied by substantial chemical and geometric reorganization.

  1. Effect of Dietary Intake of Avocado Oil and Olive Oil on Biochemical Markers of Liver Function in Sucrose-Fed Rats

    PubMed Central

    Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, Ma. Guadalupe; Melo Santiesteban, Guadalupe; Hayward-Jones, Patricia M.; Barradas-Dermitz, Dulce Ma.

    2014-01-01

    Metabolic changes, along with cardiovascular and hepatic factors, are associated with the development of diseases such as diabetes, dyslipidemia, and obesity. We evaluated the effect of avocado oil supplementation (centrifuged and solvent extracted), compared with olive oil, upon the hepatic function in sucrose-fed rats. Twenty-five rats were divided into five groups: control (basal diet), a sucrose-fed group (basal diet plus 30% sucrose solution), and three other groups (S-OO, S-AOC, and S-AOS, indicating basal diet plus 30% sucrose solution plus olive oil OO, avocado oil extracted by centrifugation AOC or using solvent AOS, resp.). Glucose, total cholesterol, triglycerides, total protein, albumin, globulin, direct bilirubin, glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, alkaline phosphatase, cholinesterase, and α-amylase concentrations were determined and avocado oil effect on them was studied. In some cases the induced metabolic alteration significantly affected total protein and bilirubin levels and also had a highly significant effect on α-amylase levels. AOC and AOS exhibited effects similar to those of olive oil, according to the nonsignificant difference in fatty acid profile observed by other authors. Avocado oil consumption could be beneficial in the control of altered metabolic profile illnesses as it presents effects on hepatic function biochemical markers similar to olive oil. PMID:24860825

  2. Comparative study of root growth and sucrose-cleaving enzymes in metallicolous and non-metallicolous populations of Rumex dentatus under copper stress.

    PubMed

    Cai, Shen-Wen; Huang, Wu-Xing; Xiong, Zhi-Ting; Ye, Feng-Ya; Ren, Cong; Xu, Zhong-Rui; Liu, Chen; Deng, Song-Qiang; Zhao, Jing

    2013-12-01

    Sucrose metabolism in roots of metallophytes is very important for root growth and maintenance of heavy metal tolerance. However, rare researches have been carried out on this topic so far. We tested here a hypothesis that roots of copper-tolerant plants should manifest higher activities of sucrose-cleaving enzymes than non-tolerant plants for maintaining root growth under Cu stress. Plants of two contrasting populations of metallophyte Rumex dentatus, one from an ancient Cu mine (MP) and the other from a non-mine site (NMP), were treated with Cu in controlled experiments. Cu treatment resulted in a higher root biomass and root/shoot biomass ratio in MP compared to NMP. More complicated root system architecture was showed in MP under Cu stress. Activities and transcript levels of acid invertase as well as contents of sucrose and reducing sugar in MP were elevated under Cu treatment, while activities of neutral/alkaline invertase and sucrose synthase showed no significant differences between two populations. The results indicate important roles of acid invertase in governing root growth under Cu stress.

  3. Differences between original intravenous iron sucrose and iron sucrose similar preparations.

    PubMed

    Toblli, Jorge Eduardo; Cao, Gabriel; Oliveri, Leda; Angerosa, Margarita

    2009-01-01

    Iron sucrose (Venofer; reference) has a good safety record and is prescribed in patients with anaemia and chronic kidney disease worldwide, but various iron sucrose similar (ISS) preparations are now utilized in clinical practice. This study evaluates possible differences between iron sucrose and ISS preparations on haemodynamic and oxidative stress markers in normal rats. 60 male and 60 female Sprague Dawley rats were divided into four groups and assigned to receive commercially available ISS test 1, ISS test 2, reference or isotonic saline solution (control). A single i.v. dose of iron (40 mg/kg) or saline (equivalent volume) was administered after 24 h and every 7 days for 4 weeks. Blood samples were collected for biological assessment of haemoglobin (Hb), serum iron and percentage transferrin saturation (TSAT), and urine samples were collected to investigate creatinine clearance and proteinuria. Animals were sacrificed after receiving an i.v. dose on days 1, 7 and 28, and kidney, liver, and heart homogenates were then collected to determine antioxidant enzyme levels. Tissues were processed using Prussian blue and immmunohistochemistry techniques to identify iron deposits, tissue ferritin and pro-inflammatory markers. Systolic blood pressure was significantly reduced in the ISS groups relative to the reference and control groups after 24 h and on days 7, 14 and 21 (p < 0.05). Creatinine clearance was reduced (p < 0.01) and proteinuria marked (p < 0.01) in the ISS groups at 24 h and on days 7 and 28 relative to the reference and control groups which did not differ throughout the study. Liver enzymes were also increased in the ISS groups at 24 h and on days 7 and 28. Both ISS test 1 and ISS test 2 groups presented a significant increase in catalase, thiobarbituric reactive species, Cu, Zn-superoxide dismutase (CuZnSOD) and glutathione peroxidase activity, and a decrease in glutathione levels (p < 0.01) in the liver, heart and kidney at 24 h and on day 7 relative

  4. Zinc electrode in alkaline electrolyte

    SciTech Connect

    McBreen, J.

    1995-12-31

    The zinc electrode in alkaline electrolyte is unusual in that supersaturated zincate solutions can form during discharge and spongy or mossy zinc deposits can form on charge at low overvoltages. The effect of additives on regular pasted ZnO electrodes and calcium zincate electrodes is discussed. The paper also reports on in situ x-ray absorption (XAS) results on mossy zinc deposits.

  5. Advanced-capability alkaline fuel cell powerplant

    NASA Astrophysics Data System (ADS)

    Deronck, Henry J.

    The alkaline fuel cell powerplant utilized in the Space Shuttle Orbiter has established an excellent performance and reliability record over the past decade. Recent AFC technology programs have demonstrated significant advances in cell durability and power density. These capabilities provide the basis for substantial improvement of the Orbiter powerplant, enabling new mission applications as well as enhancing performance in the Orbiter. Improved durability would extend the powerplant's time between overhaul fivefold, and permit longer-duration missions. The powerplant would also be a strong candidate for lunar/planetary surface power systems. Higher power capability would enable replacement of the Orbiter's auxiliary power units with electric motors, and benefits mass-critical applications such as the National AeroSpace Plane.

  6. Polyvinyl alcohol membranes as alkaline battery separators

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

    1982-01-01

    Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

  7. Acylglucuronide in alkaline conditions: migration vs. hydrolysis.

    PubMed

    Di Meo, Florent; Steel, Michele; Nicolas, Picard; Marquet, Pierre; Duroux, Jean-Luc; Trouillas, Patrick

    2013-06-01

    This work rationalizes the glucuronidation process (one of the reactions of the phase II metabolism) for drugs having a carboxylic acid moiety. At this stage, acylglucuronides (AG) metabolites are produced, that have largely been reported in the literature for various drugs (e.g., mycophenolic acid (MPA), diclofenac, ibuprofen, phenylacetic acids). The competition between migration and hydrolysis is rationalized by adequate quantum calculations, combing MP2 and density functional theory (DFT) methods. At the molecular scale, the former process is a real rotation of the drug around the glucuconic acid. This chemical-engine provides four different metabolites with various toxicities. Migration definitely appears feasible under alkaline conditions, making proton release from the OH groups. The latter reaction (hydrolysis) releases the free drug, so the competition is of crucial importance to tackle drug action and elimination. From the theoretical data, both migration and hydrolysis appear kinetically and thermodynamically favored, respectively.

  8. Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose-phosphate synthase (SPS), soluble acid (SAI) and cell-wall invertase (CWI) are importan...

  9. Drinking sucrose enhances quinpirole-induced yawning in rats.

    PubMed

    Baladi, Michelle G; Newman, Amy H; Thomas, Yvonne M; France, Charles P

    2011-12-01

    Food and drugs can activate brain dopamine systems and sensitivity to the effects of drugs acting on those systems is influenced by amount and content of food consumed. This study examined the effects of drinking sucrose on behavioral effects of the direct-acting dopamine receptor agonist quinpirole. Male Sprague-Dawley rats (n=6/group) had free access to water or 10% sucrose and quinpirole dose-response curves (yawning and hypothermia) were generated weekly for 8 weeks. Subsequently, all rats drank water for 8 weeks with quinpirole dose-response curves determined on weeks 9, 10, and 16. In rats drinking sucrose, the ascending (D3 receptor-mediated), but not descending (D2 receptor-mediated), limb of the yawning dose-response curve shifted leftward. The D3 receptor-selective antagonist PG01037 shifted the ascending limb of the dose-response curve to the right in all rats. When rats that previously drank sucrose drank water, their sensitivity to quinpirole did not return to normal. Quinpirole-induced hypothermia was not different between groups. These data show that drinking sucrose increases sensitivity to a dopamine D3, but not D2, receptor-mediated effect and that this change is long lasting. Dopamine receptors mediate the effects of many drugs and the actions of those drugs are likely impacted by dietary factors.

  10. SUCROSE SYNTHASE: ELUCIDATION OF COMPLEX POST-TRANSLATIONAL REGULATORY MECHANISMS

    SciTech Connect

    Steven C. Huber

    2009-05-12

    Studies have focused on the enzyme sucrose synthase, which plays an important role in the metabolism of sucrose in seeds and tubers. There are three isoforms of SUS in maize, referred to as SUS1, SUS-SH1, and SUS2. SUS is generally considered to be tetrameric protein but recent evidence suggests that SUS can also occur as a dimeric protein. The formation of tetrameric SUS is regulated by sucrose concentration in vitro and this could also be an important factor in the cellular localization of the protein. We found that high sucrose concentrations, which promote tetramer formation, also inhibit the binding of SUS1 to actin filaments in vitro. Previously, high sucrose concentrations were shown to promote SUS association with the plasma membrane. The specific regions of the SUS molecule involved in oligomerization are not known, but we identified a region of the SUS1 moelcule by bioinformatic analysis that was predicted to form a coiled coil. We demonstrated that this sequence could, in fact, self-associate as predicted for a coiled coil, but truncation analysis with the full-length recombinant protein suggested that it was not responsible for formation of dimers or tetramers. However, the coiled coil may function in binding of other proteins to SUS1. Overall, sugar availability may differentially influence the binding of SUS to cellular structures, and these effects may be mediated by changes in the oligomeric nature of the enzyme.

  11. Sucrose metabolism gene families and their biological functions

    PubMed Central

    Jiang, Shu-Ye; Chi, Yun-Hua; Wang, Ji-Zhou; Zhou, Jun-Xia; Cheng, Yan-Song; Zhang, Bao-Lan; Ma, Ali; Vanitha, Jeevanandam; Ramachandran, Srinivasan

    2015-01-01

    Sucrose, as the main product of photosynthesis, plays crucial roles in plant development. Although studies on general metabolism pathway were well documented, less information is available on the genome-wide identification of these genes, their expansion and evolutionary history as well as their biological functions. We focused on four sucrose metabolism related gene families including sucrose synthase, sucrose phosphate synthase, sucrose phosphate phosphatase and UDP-glucose pyrophosphorylase. These gene families exhibited different expansion and evolutionary history as their host genomes experienced differentiated rates of the whole genome duplication, tandem and segmental duplication, or mobile element mediated gene gain and loss. They were evolutionarily conserved under purifying selection among species and expression divergence played important roles for gene survival after expansion. However, we have detected recent positive selection during intra-species divergence. Overexpression of 15 sorghum genes in Arabidopsis revealed their roles in biomass accumulation, flowering time control, seed germination and response to high salinity and sugar stresses. Our studies uncovered the molecular mechanisms of gene expansion and evolution and also provided new insight into the role of positive selection in intra-species divergence. Overexpression data revealed novel biological functions of these genes in flowering time control and seed germination under normal and stress conditions. PMID:26616172

  12. The theoretical shape of sucrose crystals from energy calculations

    NASA Astrophysics Data System (ADS)

    Saska, Michael; Myerson, Allan S.

    1983-05-01

    The surface energies of individual crystallographic faces of crystalline sucrose were calculated using two forms of the 6-exp (Buckingham) potential. Hydrogen bond energies were calculated as a sum of O-H, O…H and O…O interactions where the Lippincott-Schroeder short-range potential was used for O-H and O…H pairs and the 6-exp potential for the non-bonded O…O interactions. Assuming that the surface energy equals half of the cohesive energy of the crystal, the attachment and surface energies of most of the faces found on as sucrose crystal were calculated. A computer program was written to draw the theoretical shape of crystals given the positions (central distances) of its faces. The resulting sucrose shapes are elongated along the c-axis. It is argued that the c-axis elongated habit is an intrinsic shape for vapor grown sucrose crystals (if realizable) and it is suggested that the usual shapes of solution grown sucrose crystals can be explained in terms of solvent (water) adsorption.

  13. Sucrose and polysaccharide induced obesity in the rat.

    PubMed

    Sclafani, A; Xenakis, S

    1984-02-01

    Adult male rats were fed, in addition to chow and water, solutions (32%) of either sucrose, Polycose (a bland-tasting polysaccharide), or Polycose sweetened with 0.2% saccharin. The solutions were available for two 30-day periods when the rats were 90-120, and 180-210 days of age. A control group received only chow and water during these periods. During the second 30-day test the Polycose and Saccharin- Polycose groups were hyperphagic and gained as much excess weight as did the Sucrose group. The sucrose-fed rats, however, did not overeat relative to the control animals. Adding saccharin to the Polycose failed to increase total caloric intake or weight gain, but did increase Polycose intake and percent carbohydrate intake. The intakes of both Polycose solutions were greater than that of the sucrose solution, although in brief two-bottle preference tests the sucrose solution was preferred over the Polycose and saccharin- Polycose solutions. A similar pattern of results was obtained during the first test period, but the group differences were less pronounced. The findings demonstrate that carbohydrate-induced obesity is not unique to sweet-tasting sugars, but can also be produced by bland-tasting polysaccharides. Sweet taste does increase polysaccharide preference and intake, however.

  14. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, David B.; Lao, Guifang

    1998-01-01

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium.

  15. Nucleotide sequences encoding a thermostable alkaline protease

    DOEpatents

    Wilson, D.B.; Lao, G.

    1998-01-06

    Nucleotide sequences, derived from a thermophilic actinomycete microorganism, which encode a thermostable alkaline protease are disclosed. Also disclosed are variants of the nucleotide sequences which encode a polypeptide having thermostable alkaline proteolytic activity. Recombinant thermostable alkaline protease or recombinant polypeptide may be obtained by culturing in a medium a host cell genetically engineered to contain and express a nucleotide sequence according to the present invention, and recovering the recombinant thermostable alkaline protease or recombinant polypeptide from the culture medium. 3 figs.

  16. The long-term effects of feeding honey compared with sucrose and a sugar-free diet on weight gain, lipid profiles, and DEXA measurements in rats.

    PubMed

    Chepulis, L; Starkey, N

    2008-01-01

    To determine whether honey and sucrose would have differential effects on weight gain during long-term feeding, 45 2-mo-old Sprague Dawley rats were fed a powdered diet that was either sugar-free or contained 7.9% sucrose or 10% honey ad libitum for 52 wk (honey is 21% water). Weight gain was assessed every 1 to 2 wk and food intake was measured every 2 mo. At the completion of the study blood samples were removed for measurement of blood sugar (HbA1c) and a fasting lipid profile. DEXA analyses were then performed to determine body composition and bone mineral densities. Overall weight gain and body fat levels were significantly higher in sucrose-fed rats and similar for those fed honey or a sugar-free diet. HbA1c levels were significantly reduced, and HDL-cholesterol significantly increased, in honey-fed compared with rats fed sucrose or a sugar free diet, but no other differences in lipid profiles were found. No differences in bone mineral density were observed between honey- and sucrose-fed rats, although it was significantly increased in honey-fed rats compared with those fed the sugar-free diet.

  17. Fatal anaphylactic reaction to iron sucrose in pregnancy.

    PubMed

    Mishra, Ajay; Dave, Nikhil; Viradiya, Kishor

    2013-01-01

    Iron-deficiency anemia in pregnancy can have serious deleterious effects for both mother and fetus. Parenteral iron therapy in iron-deficiency anemia is recommended in patients where oral iron therapy is ineffective due to malabsorption states and non-compliance. Compared to oral iron therapy, intravenous iron results in much more rapid resolution of iron-deficiency anemia with minimal adverse reactions. Iron sucrose has a favorable safety profile and is an alternative to other forms of parenteral iron therapy in correction of iron stores depletion. Immune mechanisms and iron agent releasing bioactive, partially unbound iron into the circulation, resulting in oxidative stress appears to cause severe adverse reactions. Although iron sucrose has a favorable safety profile in comparison to other parenteral iron preparations, this report highlights a fatal anaphylactic shock to iron sucrose in a pregnant woman with severe iron deficiency non-compliant to oral iron therapy.

  18. Changes in the physical state of sucrose during dark chocolate processing.

    PubMed

    Gloria, H; Sievert, D

    2001-05-01

    Dark chocolate tablets were manufactured using 100% crystalline sucrose, 50% crystalline and 50% amorphous sucrose, and 100% amorphous sucrose. The physical state of sucrose was determined by differential scanning calorimetry (DSC) and X-ray diffraction. DSC scans of dark chocolate samples containing amorphous sucrose were characterized by a glass transition at 63 degrees C, a sucrose crystallization peak at 105 degrees C, and a melting endotherm at 188 degrees C. Independent of the amount of amorphous or crystalline sucrose used for the preparation of dark chocolate, all final chocolate products provided a single melting endotherm at 188 degrees C and a crystalline X-ray diffraction pattern. These results indicated that sucrose crystallized during production of dark chocolate and that no amorphous sucrose was present in the final chocolate products.

  19. The Structure of Sucrose Synthase-1 from Arabidopsis thaliana and Its Functional Implications

    SciTech Connect

    Zheng, Yi; Anderson, Spencer; Zhang, Yanfeng; Garavito, R. Michael

    2014-10-02

    Sucrose transport is the central system for the allocation of carbon resources in vascular plants. During growth and development, plants control carbon distribution by coordinating sites of sucrose synthesis and cleavage in different plant organs and different cellular locations. Sucrose synthase, which reversibly catalyzes sucrose synthesis and cleavage, provides a direct and reversible means to regulate sucrose flux. Depending on the metabolic environment, sucrose synthase alters its cellular location to participate in cellulose, callose, and starch biosynthesis through its interactions with membranes, organelles, and cytoskeletal actin. The x-ray crystal structure of sucrose synthase isoform 1 from Arabidopsis thaliana (AtSus1) has been determined as a complex with UDP-glucose and as a complex with UDP and fructose, at 2.8- and 2.85-{angstrom} resolutions, respectively. The AtSus1 structure provides insights into sucrose catalysis and cleavage, as well as the regulation of sucrose synthase and its interactions with cellular targets.

  20. Deregulation of Sucrose-Controlled Translation of a bZIP-Type Transcription Factor Results in Sucrose Accumulation in Leaves

    PubMed Central

    Lee, Sung Shin; Yang, Seung Hwan; Zhu, XuJun; Imai, Ryozo; Takahashi, Yoshihiro; Kusano, Tomonobu

    2012-01-01

    Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S - stands for small) basic region-leucine zipper (bZIP)-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT). It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF) found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5′-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5′-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3–4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content. PMID:22457737

  1. The secondary alkaline zinc electrode

    NASA Astrophysics Data System (ADS)

    McLarnon, Frank R.; Cairns, Elton J.

    1991-02-01

    The worldwide studies conducted between 1975 and 1990 with the aim of improving cell lifetimes of secondary alkaline zinc electrodes are overviewed. Attention is given the design features and characteristics of various secondary alkaline zinc cells, including four types of zinc/nickel oxide cell designs (vented static-electrolyte, sealed static-electrolyte, vibrating-electrode, and flowing-electrolyte); two types of zinc/air cells (mechanically rechargeable consolidated-electrode and mechanically rechargeable particulate-electrode); zinc/silver oxide battery; zinc/manganese dioxide cell; and zinc/ferric cyanide battery. Particular consideration is given to recent research in the fields of cell thermodynamics, zinc electrodeposition, zinc electrodissolution, zinc corrosion, electrolyte properties, mathematical and phenomenological models, osmotic pumping, nonuniform current distribution, and cell cycle-life perforamnce.

  2. In vitro growth of Curcuma longa L. in response to five mineral elements and plant density in fed-batch culture systems.

    PubMed

    El-Hawaz, Rabia F; Bridges, William C; Adelberg, Jeffrey W

    2015-01-01

    Plant density was varied with P, Ca, Mg, and KNO3 in a multifactor experiment to improve Curcuma longa L. micropropagation, biomass and microrhizome development in fed-batch liquid culture. The experiment had two paired D-optimal designs, testing sucrose fed-batch and nutrient sucrose fed-batch techniques. When sucrose became depleted, volume was restored to 5% m/v sucrose in 200 ml of modified liquid MS medium by adding sucrose solutions. Similarly, nutrient sucrose fed-batch was restored to set points with double concentration of treatments' macronutrient and MS micronutrient solutions, along with sucrose solutions. Changes in the amounts of water and sucrose supplementations were driven by the interaction of P and KNO3 concentrations. Increasing P from 1.25 to 6.25 mM increased both multiplication and biomass. The multiplication ratio was greatest in the nutrient sucrose fed-batch technique with the highest level of P, 6 buds/vessel, and the lowest level of Ca and KNO3. The highest density (18 buds/vessel) produced the highest fresh biomass at the highest concentrations of KNO3 and P with nutrient sucrose fed-batch, and moderate Ca and Mg concentrations. However, maximal rhizome dry biomass required highest P, sucrose fed-batch, and a moderate plant density. Different media formulations and fed-batch techniques were identified to maximize the propagation and storage organ responses. A single experimental design was used to optimize these dual purposes.

  3. Novel aggregate formation of a frame-shift mutant protein of tissue-nonspecific alkaline phosphatase is ascribed to three cysteine residues in the C-terminal extension. Retarded secretion and proteasomal degradation.

    PubMed

    Komaru, Keiichi; Ishida, Yoko; Amaya, Yoshihiro; Goseki-Sone, Masae; Orimo, Hideo; Oda, Kimimitsu

    2005-04-01

    In the majority of hypophosphatasia patients, reductions in the serum levels of alkaline phosphatase activity are caused by various missense mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. A unique frame-shift mutation due to a deletion of T at cDNA number 1559 [TNSALP (1559delT)] has been reported only in Japanese patients with high allele frequency. In this study, we examined the molecular phenotype of TNSALP (1559delT) using in vitro translation/translocation system and COS-1 cells transiently expressing this mutant protein. We showed that the mutant protein not only has a larger molecular size than the wild type enzyme by approximately 12 kDa, reflecting an 80 amino acid-long extension at its C-terminus, but that it also lacks a glycosylphosphatidylinositol anchor. In support of this, alkaline phosphatase activity of the cells expressing TNSALP (1559delT) was localized at the juxtanucleus position, but not on the cell surface. However, only a limited amount of the newly synthesized protein was released into the medium and the rest was polyubiquitinated, followed by degradation in the proteasome. SDS/PAGE and analysis by sucrose-density-gradient analysis indicated that TNSALP (1559delT) forms a disulfide-bonded high-molecular-mass aggregate. Interestingly, the aggregate form of TNSALP (1559delT) exhibited a significant enzyme activity. When all three cysteines at positions of 506, 521 and 577 of TNSALP (1559delT) were replaced with serines, the aggregation disappeared and instead this modified mutant protein formed a noncovalently associated dimer, strongly indicating that these cysteine residues in the C-terminal region are solely responsible for aggregate formation by cross-linking the catalytically active dimers. Thus, complete absence of TNSALP on cell surfaces provides a plausible explanation for a severe lethal phenotype of a homozygote hypophosphatasia patient carrying TNSALP (1559delT).

  4. New rat models of iron sucrose-induced iron overload.

    PubMed

    Vu'o'ng Lê, Bá; Khorsi-Cauet, Hafida; Villegier, Anne-Sophie; Bach, Véronique; Gay-Quéheillard, Jérôme

    2011-07-01

    The majority of murine models of iron sucrose-induced iron overload were carried out in adult subjects. This cannot reflect the high risk of iron overload in children who have an increased need for iron. In this study, we developed four experimental iron overload models in young rats using iron sucrose and evaluated different markers of iron overload, tissue oxidative stress and inflammation as its consequences. Iron overload was observed in all iron-treated rats, as evidenced by significant increases in serum iron indices, expression of liver hepcidin gene and total tissue iron content compared with control rats. We also showed that total tissue iron content was mainly associated with the dose of iron whereas serum iron indices depended essentially on the duration of iron administration. However, no differences in tissue inflammatory and antioxidant parameters from controls were observed. Furthermore, only rats exposed to daily iron injection at a dose of 75 mg/kg body weight for one week revealed a significant increase in lipid peroxidation in iron-treated rats compared with their controls. The present results suggest a correlation between iron overload levels and the dose of iron, as well as the duration and frequency of iron injection and confirm that iron sucrose may not play a crucial role in inflammation and oxidative stress. This study provides important information about iron sucrose-induced iron overload in rats and may be useful for iron sucrose therapy for iron deficiency anemia as well as for the prevention and diagnosis of iron sucrose-induced iron overload in pediatric patients.

  5. Sucrose: A Prospering and Sustainable Organic Raw Material

    NASA Astrophysics Data System (ADS)

    Peters, Siegfried; Rose, Thomas; Moser, Matthias

    Sucrose (α-d-glucopyranosyl-(1→2)-β-d-fructofuranoside) is an inexpensive chemical produced by sugar cane and sugar beet cultivation. Chemical and/or biochemical transformations convert it into highly valuable synthetic intermediates such as 5-hydroxymethylfurfural (HMF), bioethylene, 1,2-propylene glycol and levulinic acid. Sucrose can also be converted into biodegradable polymers such as polyesters and polyurethanes, as well as into novel carbohydrates such as isomaltulose, trehalulose, inulin, levan, Neo-amylose, and dextran, highly valuable additives for food and cosmetics and materials for separation and purification technologies.

  6. Does sucrose or aspartame cause hyperactivity in children?

    PubMed

    Kanarek, R B

    1994-05-01

    Anecdotal evidence has led to the hypothesis that there is a relationship between sugar intake and hyperactive behavior. To assess this hypothesis, a recent study using a range of behavioral and cognitive measures evaluated the effects of diets high in sucrose, aspartame, and saccharin on the performance of school-aged children believed to be sensitive to sugar, and preschool children. Although intakes exceeded average dietary levels, neither sucrose nor aspartame negatively affected behavior. Taken together with previous work, these results indicate that sugar is not a major cause of hyperactivity.

  7. [Derivative gas chromatographic analysis of fructooligosaccharide in fermented sucrose].

    PubMed

    Cai, W M; Liu, H; Sun, X J

    2000-01-01

    As a new sweetener, fructooligosaccharide is paid more and more attention for its health improvement property. It includes trisaccharide, tetrasaccharide and pentasaccharide, and can be produced from sucrose by the fermentation of microorganism. In order to analyze the content of fructooligosaccharide in fermented sugar by gas chromatography, fructooligosaccharide was transformed into trimethylsilyl derivatives. Based on the modified gas chromatograph SP2308, and under the chosen chromatographic conditions with 0.53 mm capillary column of OV-101, the contents of fructose, glucose, sucrose and fructooligosaccharide were determined by programmed temperature chromatography. The recovery of fructooligosaccharide was satisfactory.

  8. Amperometric biosensors for determination of glucose, maltose, and sucrose

    NASA Astrophysics Data System (ADS)

    Zawicki, Ignacy; Filipiak, Marian; Jarzyna, Marta; Laskowska, Janina

    1995-06-01

    In the presented paper there are reported some results of the author's research on membranes containing glucose oxidase (GOx), enzymes hydrolyzing maltose and sucrose and on biosensors equipped with these membranes. The results relate to ways of extending the linear range of glucose sensors, influence of composition of the membranes on levels of the output signals of maltose and sucrose (saccharose) sensors, temperature dependence of the sensor's response and on disturbing effects of glucose in the sample on accuracy of determination of the disaccharides.

  9. Anharmonicity and hydrogen bonding in electrooptic sucrose crystal

    NASA Astrophysics Data System (ADS)

    Szostak, M. M.; Giermańska, J.

    1990-03-01

    The polarized absorption spectra of the sucrose crystal in the 5300 - 7300 cm -1 region have been measured. The assignments of all the eight OH stretching overtones are proposed and their mechanical anharmonicities are estimated. The discrepancies from the oriented gas model (OGM) in the observed relative band intensities, especially of the -CH vibrations, are assumed to be connected with vibronic couplings enhanced by the helical arrangement of molecules joined by hydrogen bondings. It seems that this kind of interactions might be important for the second harmonic generation (SHG) by the sucrose crystal.

  10. Method for converting sucrose to .beta.-D-glucose

    SciTech Connect

    Simmons,; Blake A.; Volponi, Joanne V.; Ingersoll, David; Walker, Andrew

    2009-07-07

    Disclosed is an apparatus and method for continuously converting sucrose to .beta.-D-glucose. The method comprises a three-stage enzymatic reactor in which an aqueous solution of sucrose is first converted into a solution of fructose and .alpha.-D-glucose by passing it through a porous, packed column containing an inert media on which invertase is immobilized. This solution is then sent through a second packed column containing glucose isomerase and finally a third packed column containing mutarotase. Solution temperature and pH are adjusted to maximize glucose output.

  11. Effects of agave nectar versus sucrose on weight gain, adiposity, blood glucose, insulin, and lipid responses in mice.

    PubMed

    Hooshmand, Shirin; Holloway, Brittany; Nemoseck, Tricia; Cole, Sarah; Petrisko, Yumi; Hong, Mee Young; Kern, Mark

    2014-09-01

    Agave nectar is a fructose-rich liquid sweetener derived from a plant, and is often promoted as a low glycemic alternative to refined sugar. However, little scientific research has been conducted in animals or humans to determine its metabolic and/or health effects. The aim of this study was to explore the influence of agave nectar versus sucrose on weight gain, adiposity, fasting plasma blood glucose, insulin, and lipid levels. Eighteen (n=18) male ICR mice (33.8±1.6 g) were divided into two groups (n=6 for agave nectar and n=12 for sucrose) and provided free access to one of two diets of equal energy densities differing only in a portion of the carbohydrate provided. Diets contained 20% carbohydrate (by weight of total diet) from either raw agave nectar or sucrose. Epididymal fat pads were excised, and blood was collected after 34 days. Weight gain (4.3±2.2 vs. 8.4±3.4 g), fat pad weights (0.95±0.54 vs. 1.75±0.66 g), plasma glucose (77.8±12.2 vs. 111.0±27.9 mg/dL), and insulin (0.61±0.29 vs. 1.46±0.81 ng/mL) were significantly lower (P≤.05) for agave nectar-fed mice compared to sucrose-fed mice respectively. No statistically significant differences in total cholesterol or triglycerides were detected. These results suggest that in comparison to sucrose, agave nectar may have a positive influence on weight gain and glucose control. However, more research with a larger sample of animals and/or with human subjects is warranted.

  12. The effect of sucrose on unfrozen water and syneresis of acidified sodium caseinate-xanthan gels.

    PubMed

    Braga, A L M; Cunha, R L

    2005-07-01

    The influence of the ingredients of acidified Na caseinate-xanthan-sucrose gels on thermophysical properties and syneresis of the gels was studied. Sucrose concentration affected all of the gel equilibrium properties and the rate of syneresis. The positive effect of sucrose on syneresis and unfrozen water (UFW) values was attributed to different effects. The amount of UFW was governed mainly by the colligative properties of sucrose whereas the equilibrium syneresis behaviour was associated with the changes in network dynamics caused by the kosmotropic properties of sucrose. The latter could enhance xanthan-sucrose association or favour xanthan-protein interactions.

  13. Direct Hydrothermal Precipitation of Pyrochlore-Type Tungsten Trioxide Hemihydrate from Alkaline Sodium Tungstate Solution

    NASA Astrophysics Data System (ADS)

    Li, Xiaobin; Li, Jianpu; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui

    2012-04-01

    Pyrochlore-type tungsten trioxide hemihydrate (WO3·0.5H2O) powder with the average particle size of 0.5 μm was prepared successfully from the weak alkaline sodium tungstate solution by using organic substances of sucrose or cisbutenedioic acid as the acidification agent. The influences of solution pH and acidification agents on the precipitation process were investigated. The results showed that organic acidification agents such as sucrose and cisbutenedioic acid could improve the precipitation of pyrochlore WO3·0.5H2O greatly from sodium tungstate solution compared with the traditional acidification agent of hydrochloric acid. In addition, the pH value of the hydrothermal system played a critical role in the precipitation process of WO3·0.5H2O, and WO3·0.5H2O precipitation mainly occured in the pH range of 7.0 to 8.5. The precipitation rate of tungsten species in the sodium tungstate solution could reach up to 98 pct under the optimized hydrothermal conditions. This article proposed also the hydrothermal precipitation mechanism of WO3·0.5H2O from the weak alkaline sodium tungstate solution. The novel method reported in this study has a great potential to improve the efficiency of advanced tungsten trioxide-based functional material preparation, as well as for the pollution-reducing and energy-saving tungsten extractive metallurgy.

  14. The influence of temperature, sucrose and lactose on dilute solution properties of basil (Ocimumbasilicum) seed gum.

    PubMed

    Mirabolhassani, Seyed Elias; Rafe, Ali; Razavi, Seyed M A

    2016-12-01

    Hydrocolloid interactions with solvent/cosolutes play a vital role in the resolution of their functional properties. Basil seed gum (BSG) is a plant-derived hydrocolloid which has been found many applications in food formulations as stabilizer, emulsifier, thickener and gelling agents. Sucrose and lactose are the most effective sugars in textural and sensorial properties of bakery and dairy products which adding them to solutions containing hydrocolloids can be helpful to approach a proper formula. In this paper, the effect of temperature (25-65°C), sucrose (10, 20, 30 and 40%) and lactose (5, 10 and 15%) were investigated through some molecular parameters of BSG. Results revealed high flexible chain (665.35), intrinsic viscosity (11.38 dl/g) and hydrogel content (73%) of BSG, which may be attributed to some extent by its high molecular weight (1.73×10(6)Da). The density and intrinsic viscosity of BSG were diminished by growing temperature from 25 to 55°C. Among five models, which were applied to estimate intrinsic viscosity, Higiro-2 was the most suitable model at varying temperatures and cosolutes concentrations. The sugars showed a significant effect on the molecular parameters of BSG such as swollen specific volume, shape function, hydration parameter, and coil dimensions. The sugars showed more impact on the [η] of BSG and its molecular parameters than that of temperature. However, lactose had a more prominent effect on the BSG dimensions than that of sucrose, which can be related to its molecular conformation and spatial orientation. It is feasible to make a proper formula by BSG and explain some phenomena in its applications in food and pharmaceutical systems.

  15. Reinforcement value and substitutability of sucrose and wheel running: implications for activity anorexia.

    PubMed

    Belke, Terry W; Pierce, W David; Duncan, Ian D

    2006-09-01

    Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained wheel-running reinforcement did not change. Overall, the results suggested that food-deprived rats were sensitive to qualitative changes in food supply (sucrose concentration) while continuing to defend a level of physical activity (wheel running). In the second study, 15 female Long Evans rats were exposed to concurrent variable ratio schedules of sucrose and wheel-running, wheel-running and wheel-running, and sucrose and sucrose reinforcement. For each pair of reinforcers, substitutability was assessed by the effect of income-compensated price changes on consumption of the two reinforcers. Results showed that, as expected, sucrose substituted for sucrose and wheel running substituted for wheel running. Wheel running, however, did not substitute for sucrose; but sucrose partially substituted for wheel running. We address the implications of the interrelationships of sucrose and wheel running for an understanding of activity anorexia.

  16. Avocado Oil Supplementation Modifies Cardiovascular Risk Profile Markers in a Rat Model of Sucrose-Induced Metabolic Changes

    PubMed Central

    Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, M. Guadalupe; Melo-Santiesteban, Guadalupe; Hayward-Jones, Patricia M.; Barradas-Dermitz, Dulce M.

    2014-01-01

    The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome. PMID:24719499

  17. Fabrication of carbon-felt-based multi-enzyme immobilized anodes to oxidize sucrose for biofuel cells.

    PubMed

    Handa, Yutaka; Yamagiwa, Kiyofumi; Ikeda, Yutaro; Yanagisawa, Yuichi; Watanabe, Shinya; Yabuuchi, Naoaki; Komaba, Shinichi

    2014-07-21

    A carbon-felt-based multi-enzyme immobilized bioanode for biofuel cells has been successfully developed. The combination of four enzymes, namely, invertase, mutarotase, glucose oxidase, and fructose dehydrogenase, makes it possible to use sucrose--a disaccharide--as fuel for the bioanode. The new electrode exhibits a high oxidation current density of about 12 mA cm(-2) (0.25 V vs. Ag/AgCl) in a McIlvaine buffer solution containing sucrose at pH 6.0 in the half-cell configuration. A sucrose/O(2) biofuel cell composed of the bioanode and an opposite biocathode, including bilirubin oxidase as the enzymatic electrocatalyst, was fabricated, and the new device demonstrated a maximum power density of 2.90 mW cm(-2) with an open-circuit voltage of 0.69 V in the McIlvaine buffer solution. The biofuel cell fabricated using our multi-enzyme anode operates in commercially available beverages that contain only sugar, even without glucose.

  18. Avocado oil supplementation modifies cardiovascular risk profile markers in a rat model of sucrose-induced metabolic changes.

    PubMed

    Carvajal-Zarrabal, Octavio; Nolasco-Hipolito, Cirilo; Aguilar-Uscanga, M Guadalupe; Melo-Santiesteban, Guadalupe; Hayward-Jones, Patricia M; Barradas-Dermitz, Dulce M

    2014-01-01

    The purpose of this study was to evaluate the effects of avocado oil administration on biochemical markers of cardiovascular risk profile in rats with metabolic changes induced by sucrose ingestion. Twenty-five rats were divided into five groups: a control group (CG; basic diet), a sick group (MC; basic diet plus 30% sucrose solution), and three other groups (MCao, MCac, and MCas; basic diet plus 30% sucrose solution plus olive oil and avocado oil extracted by centrifugation or using solvent, resp.). Glucose, total cholesterol, triglycerides, phospholipids, low- and high-density lipoproteins (LDL, HDL), very low-density lipoprotein (VLDL), lactic dehydrogenase, creatine kinase, and high sensitivity C-reactive protein concentration were analyzed. Avocado oil reduces TG, VLDL, and LDL levels, in the LDL case significantly so, without affecting HDL levels. An effect was exhibited by avocado oil similar to olive oil, with no significant difference between avocado oil extracted either by centrifugation or solvent in myocardial injury biochemical indicators. Avocado oil decreased hs-CRP levels, indicating that inflammatory processes were partially reversed. These findings suggested that avocado oil supplementation has a positive health outcome because it reduces inflammatory events and produces positive changes in the biochemical indicators studied, related to the development of metabolic syndrome.

  19. Sucrose Responsiveness, Learning Success, and Task Specialization in Ants

    ERIC Educational Resources Information Center

    Perez, Margot; Rolland, Uther; Giurfa,, Martin; d'Ettorre, Patrizia

    2013-01-01

    Social insects possess remarkable learning capabilities, which are crucial for their ecological success. They also exhibit interindividual differences in responsiveness to environmental stimuli, which underlie task specialization and division of labor. Here we investigated for the first time the relationships between sucrose responsiveness,…

  20. Regulation of sucrose synthesis in water stressed leaves

    SciTech Connect

    Daie, J.; Aloni, B. )

    1991-05-01

    Alteration in carbon metabolism and carbohydrate partitioning occur in drought stressed plants. Some species accumulate large quantities of starch in the chloroplast, which may be used to support sucrose synthesis under conditions of limited carbon supply. The authors monitored chemical partitioning of carbon between sugars and starch and the activity of sucrose phosphate synthase (SPS) and fructose 1,6 bisphosphatase (FBPase) in the source leaves of water stressed tomatoes. Plants were stressed by withdrawing water for 10 days and rewatered for recovery. Water potential dropped from {minus}0.8 to {minus}2.2MPA in 10 days, but recovered to control level 2 days after rewatering. Photosynthetic rates as measured by the activity of Rubisco followed similar patterns to those of water potential. After 10 days, leaf starch levels decreased to less than 50% of control. Sucrose levels did not increase significantly, but hexose levels increased 3-4 fold during the stress period, and decreased to control levels 1 day after rewatering. FBPase activity decreased and SPS activity increased under stress conditions. Upon rewatering, the activity of FBPase and SPS returned to control levels. Presence of large quantities of hexose and activation of SPS in stressed leaves suggested that additional sucrose synthesized under stress was hydrolyzed to hexoses, presumably due to enhanced invertase activity.

  1. Effects of sucrose ingestion on the behavior of hyperactive boys.

    PubMed

    Wolraich, M; Milich, R; Stumbo, P; Schultz, F

    1985-04-01

    A challenge design was used in two separate studies to investigate the effects of sucrose ingestion on the behavior and learning of hyperactive boys. In both studies, 16 boys were admitted to a clinical research center for 3 successive days, on each of which they were given a sucrose-free diet. On day 1, baseline levels on the learning tasks were established; on days 2 and 3 a challenge drink of either sucrose 1.75 gm/kg or a placebo (aspartame in equivalent sweetness) was presented, in a counterbalanced order. In the first study the challenge drink was administered 1 hour after lunch; in the second study it was given in the morning after an overnight fast. On days 2 and 3 of both studies, 37 behavioral (playroom observation and examiner ratings) and cognitive (learning and memory tasks) measures were collected, starting 1/2 hour after ingestion of the drink. The results of both studies revealed no differences between the boys' performance on the two challenge days. These findings undermine the hypothesis that sucrose plays a major role in accounting for the inappropriate behavior of hyperactive boys.

  2. Relationships among impurity components, sucrose, and sugarbeet processing quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sodium, potassium, amino-nitrogen, and invert sugar are naturally-occurring constituents of the sugarbeet (Beta vulgaris L.) root, referred to as impurities, which impede sucrose extraction during routine factory operations. Three germplasm lines selected for low sodium, potassium, or amino-nitrogen...

  3. Reducing sucrose loss in sugar beet storage with fungicides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root rots in sugar beet storage can lead to multi-million dollar losses because of reduced sucrose recovery. Thus, studies were conducted to establish better chemical control options and a better understanding of the fungi involved in the rot complex. A water check and three fungicides (Mertect, Pro...

  4. Synthesis of carbon-13 enriched disaccharides: lactose and sucrose

    SciTech Connect

    Walker, T.E.; Unkefer, P.J.; Unkefer, C.J.; Ehler, D.S.

    1986-05-01

    Disaccharides can be prepared enzymatically and by chemical synthesis. Lactose enriched with carbon-13 at C-1 can be synthesized by reacting K/sup 13/CN with a sugar having a one fewer carbon than the desired product. Thus, a mixture of 4-O-..beta..-D-galactopyranosyl-D-(1-/sup 13/C)glucose ((1-/sup 13/C)lactose) and 4-O-..beta..-D-galactopyranosyl-D-(1-/sup 13/C)mannose can be synthesized from 3-O-..beta..-D-galactopyranosyl-D-arabinose and K/sup 13/CN. (/sup 13/C)Sucrose is conveniently prepared in gram quantities from D-(/sup 13/C)fructose and UDP-glucose in a reaction catalyzed by the enzyme sucrose synthetase. This reaction proceeds smoothly at 25/sup 0/ over a period of hours to give an equilibrium mixture which can be separated chromatographically. The glucose portion of sucrose can be labeled using enzymatically-prepared UDP-(/sup 13/C)glucose. Labeled sucrose is important for the preparation of labeled starches to be used for structural and metabolic studies.

  5. Ocean Acidification: Coccolithophore's Light Controlled Effect on Alkalinity

    NASA Astrophysics Data System (ADS)

    Dobbins, W.

    2015-12-01

    Coccolithophorids, which play a significant role in the flux of calcite and organic carbon from the photic region to deeper pelagic and benthic zones, are potentially far more useful than siliceous phytoplankton for ocean fertilization projects designed to sequester CO2. However, the production of H+ ions during calcification (HCO3 + Ca+ —> CaCO3 + H+) has resulted in localized acidification around coccolithophore blooms. It has been hypothesized that under the correct light conditions photosynthesis could proceed at a rate such that CO2 is removed in amounts equimolar or greater than the H+ produced by calcification, allowing stable or increasing alkalinity despite ongoing calcification. Previously, this effect had not been demonstrated under laboratory conditions. Fifteen Emiliania huxleyi cultures were separated into equal groups with each receiving: 0, 6, 12, 18, or 24 hours of light each day for 24 days. Daily pH, cell density, and temperature measurements revealed a strong positive correlation between light exposure and pH, and no significant decline in pH in any of the cultures. Alkalinity increases were temperature independent and not strongly correlated with cell density, implying photosynthetic removal of carbon dioxide as the root cause. The average pH across living cultures increased from 7.9 to 8.3 over the first week and changed little for the reminder of the 24-day period. The results demonstrate coccolithophorids can increase alkalinity across a broad range of cell densities, despite the acidification inherent to the calcification process. If the light-alkalinity effect reported here proves scalable to larger cultures, Emiliania huxleyi are a strong candidate for carbon sequestration via targeted ocean fertilization.

  6. Diclofenac salts. III. Alkaline and earth alkaline salts.

    PubMed

    Fini, Adamo; Fazio, Giuseppe; Rosetti, Francesca; Angeles Holgado, M; Iruín, Ana; Alvarez-Fuentes, Josefa

    2005-11-01

    Diclofenac salts containing the alkaline and two earth alkaline cations have been prepared and characterized by scanning electron microscopy (SEM) and EDAX spectroscopy; and by thermal and thermogravimetric analysis (TGA): all of them crystallize as hydrate when precipitated from water. The salts dehydrate at room temperature and more easily on heating, but recovery the hydration, when placed in a humid environment. X-ray diffraction spectra suggest that on dehydration new peaks appear on diffractograms and the lattice of the salts partially looses crystallinity. This phenomenon is readily visible in the case of the calcium and magnesium salts, whose thermograms display a crystallization exotherm, before melting or decomposing at temperatures near or above 200 degrees C; these last salts appear to form solvates, when prepared from methanol. The thermogram of each salt shows a complex endotherm of dehydration about 100 degrees C; the calcium salt displays two endotherms, well separated at about 120 and 160 degrees C, which disappear after prolonged heating. Decomposition exotherms, before or soon after the melting, appear below 300 degrees C. The ammonium salt is thermally unstable and, when heated to start dehydration, dissociates and leaves acidic diclofenac.

  7. Characterization of Saccharomyces strains with respect to their ability to grow and ferment in the presence of ethanol and sucrose

    NASA Astrophysics Data System (ADS)

    Benitez, T.; Delcastillo, L.; Aguilera, A.; Conde, J.; Cerda-Olmedo, E.

    1982-12-01

    To optimize the conversion of carbohydrates to ethanol strains of several Saccharomyces species were examined for their ability to grow and ferment in a range of sucrose and ethanol concentrations. Isolated wine yeasts grew in the presence of 10% ethanol to the same final cell density as control cultures without ethanol. The best of these yeast strains grew in the presence of 15% ethanol and fermented in 18%. Ethanol accumulated, although at a reduced rate, after the cells stopped growing. Most yeast strains were highly fermentative in 50% sucrose. Some of them effectively utilized the carbohydrates of the culture, yielding final ethanol concentrations over 14%. Sixteen of the 35 strains were chosen for genetic analysis and breeding because of their capacity to sporulate. These strains are homothallic and their spores are viable.

  8. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

    PubMed

    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L

    2014-01-01

    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

  9. New insight into the catalytic properties of rice sucrose synthase.

    PubMed

    Huang, Yu-Chiao; Hsiang, Erh-Chieh; Yang, Chien-Chih; Wang, Ai-Yu

    2016-01-01

    Sucrose synthase (SuS), which catalyzes the reversible conversion of sucrose and uridine diphosphate (UDP) into fructose and UDP-glucose, is a key enzyme in sucrose metabolism in higher plants. SuS belongs to family 4 of the glycosyltransferases (GT4) and contains an E-X7-E motif that is conserved in members of GT4 and two other GT families. To gain insight into the roles of this motif in rice sucrose synthase 3 (RSuS3), the two conserved glutamate residues (E678 and E686) in this motif and a phenylalanine residue (F680) that resides between the two glutamate residues were changed by site-directed mutagenesis. All mutant proteins maintained their tetrameric conformation. The mutants E686D and F680Y retained partial enzymatic activity and the mutants E678D, E678Q, F680S, and E686Q were inactive. Substrate binding assays indicated that UDP and fructose, respectively, were the leading substrates in the sucrose degradation and synthesis reactions of RSuS3. Mutations on E678, F680, and E686 affected the binding of fructose, but not of UDP. The results indicated that E678, F680, and E686 in the E-X7-E motif of RSuS3 are essential for the activity of the enzyme and the sequential binding of substrates. The sequential binding of the substrates implied that the reaction catalyzed by RSuS can be controlled by the availability of fructose and UDP, depending on the metabolic status of a tissue.

  10. Alkaline fuel cell performance investigation

    NASA Technical Reports Server (NTRS)

    Martin, R. E.; Manzo, M. A.

    1988-01-01

    An exploratory experimental fuel cell test program was conducted to investigate the performance characteristics of alkaline laboratory research electrodes. The objective of this work was to establish the effect of temperature, pressure, and concentration upon performance and evaluate candidate cathode configurations having the potential for improved performance. The performance characterization tests provided data to empirically establish the effect of temperature, pressure, and concentration upon performance for cell temperatures up to 300 F and reactant pressures up to 200 psia. Evaluation of five gold alloy cathode catalysts revealed that three doped gold alloys had more that two times the surface areas of reference cathodes and therefore offered the best potential for improved performance.

  11. The Trehalose Phosphotransferase System (PTS) in E. coli W Can Transport Low Levels of Sucrose that Are Sufficient to Facilitate Induction of the csc Sucrose Catabolism Operon

    PubMed Central

    Steen, Jennifer A.; Bohlke, Nina; Vickers, Claudia E.; Nielsen, Lars K.

    2014-01-01

    Plasticity in substrate acceptance is a well-characterised phenomenon for disaccharide transporters. Sucrose, a non-reducing disaccharide, is usually metabolised via either the permease-mediated chromosomally-encoded sucrose catabolism (csc) regulon or the sucrose phosphotransferase system (PTS). E. coli W is a fast-growing strain which efficiently utilises sucrose at concentrations above 1% via the csc regulon. To examine if sucrose could be metabolised via other routes, a library of transposon mutants was generated and screened on 0.2% sucrose. One mutant identified from this library had an insertion in the repressor for the regulon controlling catabolism of the disaccharide trehalose (treR). A series of mutants was constructed to elucidate the mechanism of sucrose utilization in the treR insertion strain. Analysis of these mutants provided evidence that deletion of TreR enables uptake of sucrose via TreB, an enzyme II protein required for PTS-mediated uptake of trehalose. Once inside the cell, this sucrose is not processed by the TreC hydrolase, nor is it sufficient for growth of the strain. QRT-PCR analysis showed that levels of cscA (invertase) transcript increased in the WΔtreR mutant relative to the wild-type strain when grown under low sucrose conditions. This result suggests that the intracellular sucrose provided by TreB can facilitate de-repression of the csc regulon, leading to increased gene expression, sucrose uptake and sucrose utilization in the treR mutant. PMID:24586369

  12. Prolonged Consumption of Sucrose in a Binge-Like Manner, Alters the Morphology of Medium Spiny Neurons in the Nucleus Accumbens Shell

    PubMed Central

    Klenowski, Paul M.; Shariff, Masroor R.; Belmer, Arnauld; Fogarty, Matthew J.; Mu, Erica W. H.; Bellingham, Mark C.; Bartlett, Selena E.

    2016-01-01

    The modern diet has become highly sweetened, resulting in unprecedented levels of sugar consumption, particularly among adolescents. While chronic long-term sugar intake is known to contribute to the development of metabolic disorders including obesity and type II diabetes, little is known regarding the direct consequences of long-term, binge-like sugar consumption on the brain. Because sugar can cause the release of dopamine in the nucleus accumbens (NAc) similarly to drugs of abuse, we investigated changes in the morphology of neurons in this brain region following short- (4 weeks) and long-term (12 weeks) binge-like sucrose consumption using an intermittent two-bottle choice paradigm. We used Golgi-Cox staining to impregnate medium spiny neurons (MSNs) from the NAc core and shell of short- and long-term sucrose consuming rats and compared these to age-matched water controls. We show that prolonged binge-like sucrose consumption significantly decreased the total dendritic length of NAc shell MSNs compared to age-matched control rats. We also found that the restructuring of these neurons resulted primarily from reduced distal dendritic complexity. Conversely, we observed increased spine densities at the distal branch orders of NAc shell MSNs from long-term sucrose consuming rats. Combined, these results highlight the neuronal effects of prolonged binge-like intake of sucrose on NAc shell MSN morphology. PMID:27047355

  13. Consumption of sucrose from infancy increases the visceral fat accumulation, concentration of triglycerides, insulin and leptin, and generates abnormalities in the adrenal gland.

    PubMed

    Díaz-Aguila, Yadira; Castelán, Francisco; Cuevas, Estela; Zambrano, Elena; Martínez-Gómez, Margarita; Muñoz, Alvaro; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2016-03-01

    Consumption of sugar-sweetened beverages promotes the development of metabolic syndrome (MetS) and type 2 diabetes mellitus in humans. One factor related to the appearance of MetS components is the dysfunction of the adrenal gland. In fact, the experimental generation of hyperglycemia has been associated with morphological and microvascular changes in the adrenal glands of rats. We hypothesized that high sucrose consumption from infancy promotes histological disruption of the adrenal glands associated with the appearance of metabolic syndrome indicators. Male Wistar rats were separated at weaning (21 days old) into two groups: free access to tap water (control group, C) or 30 % sucrose diluted in water (sugar-fed group). After 12 weeks, high sucrose consumption promoted an increase in visceral fat accumulation, adipose cell number, and insulin resistance. Also, a rise in the concentration of triglycerides, very low-density lipoprotein, insulin and leptin was observed. In control rats, a histomorphometric asymmetry between the right and left adrenal glands was found. In the sugar-fed group, sucrose consumption produced a major change in adrenal gland asymmetry. No changes in corticosterone serum level were observed in either group. Our results suggest that a high sucrose liquid-diet from early life alters the morphology of adrenocortical zones, leading to MetS indicators.

  14. The Path of Carbon in Photosynthesis XIX. The Identification of Sucrose Phosphate in Sugar Beet Leaves

    DOE R&D Accomplishments Database

    Buchanan, J. G.

    1952-09-01

    The recognition and characterization of a sucrose phosphate as an intermediate in sucrose by synthesis by green plants is described. A tentative structure for this phosphate is proposed and its mode of formation suggested.

  15. Sucrose Synthase in Legume Nodules Is Essential for Nitrogen Fixation1

    PubMed Central

    Gordon, Anthony J.; Minchin, Frank R.; James, Caron L.; Komina, Olga

    1999-01-01

    The role of sucrose synthase (SS) in the fixation of N was examined in the rug4 mutant of pea (Pisum sativum L.) plants in which SS activity was severely reduced. When dependent on nodules for their N supply, the mutant plants were not viable and appeared to be incapable of effective N fixation, although nodule formation was essentially normal. In fact, N and C resources invested in nodules were much greater in mutant plants than in the wild-type (WT) plants. Low SS activity in nodules (present at only 10% of WT levels) resulted in lower amounts of total soluble protein and leghemoglobin and lower activities of several enzymes compared with WT nodules. Alkaline invertase activity was not increased to compensate for reduced SS activity. Leghemoglobin was present at less than 20% of WT values, so O2 flux may have been compromised. The two components of nitrogenase were present at normal levels in mutant nodules. However, only a trace of nitrogenase activity was detected in intact plants and none was found in isolated bacteroids. The results are discussed in relation to the role of SS in the provision of C substrates for N fixation and in the development of functional nodules. PMID:10398723

  16. A theoretical study on the sucrose gap technique as applied to multicellular muscle preparations. I. Saline-sucrose interdiffusion.

    PubMed Central

    Lammel, E

    1981-01-01

    Voltage-clamp analysis of membrane currents in multicellular muscle preparations by means of the sucrose gap method is complicated by diffusion of saline and sucrose in the interstitial fluid spaces. This paper is the first part of a theoretical study made to analyze electrical events related to this diffusion process. Concentration profiles of ions and sucrose (both axial and radial) were computed by solving diffusion equations with boundary conditions appropriate for the different types of preparations and experimental arrangements used. In addition to steady-state solutions, analytical expressions were derived that describe the time-course with which concentration profiles become established after a stepwise change of the solute concentration in one of the compartments of the sucrose gap apparatus. The model accounts for the presence of an endothelial surface layer, or endocardium, which acts as an external diffusion barrier and is important in determining concentration gradients of solutes within heart cell preparations. Results of numerical computations dealing with several cases of experimental interest are presented. PMID:7326323

  17. Characterization of divergent pseudo-sucrose isomerase from Azotobacter vinelandii: Deciphering the absence of sucrose isomerase activity.

    PubMed

    Jung, Jong-Hyun; Kim, Min-Ji; Jeong, Woo-Soo; Seo, Dong-Ho; Ha, Suk-Jin; Kim, Young Wan; Park, Cheon-Seok

    2017-01-29

    Among members of the glycoside hydrolase (GH) family, sucrose isomerase (SIase) and oligo-1,6-glucosidase (O16G) are evolutionarily closely related even though their activities show different specificities. A gene (Avin_08330) encoding a putative SIase (AZOG: Azotobacterglucocosidase) from the nitrogen-fixing bacterium Azotobacter vinelandii is a type of pseudo-SIase harboring the "RLDRD" motif, a SIase-specific region in 329-333. However, neither sucrose isomerization nor hydrolysis activities were observed in recombinant AZOG (rAZOG). The rAZOG showed similar substrate specificity to Bacillus O16G as it catalyzes the hydrolysis of isomaltulose and isomaltose, which contain α-1,6-glycosidic linkages. Interestingly, rAZOG could generate isomaltose from the small substrate methyl-α-glucoside (MαG) via intermolecular transglycosylation. In addition, sucrose isomers isomaltulose and trehalulose were produced when 250 mM fructose was added to the MαG reaction mixture. The conserved regions I and II of AZOG are shared with many O16Gs, while regions III and IV are very similar to those of SIases. Strikingly, a shuffled AZOG, in which the N-terminal region of SIase containing conserved regions I and II was exchanged with the original enzyme, exhibited a production of sucrose isomers. This study demonstrates an evolutionary relationship between SIase and O16G and suggests some of the main regions that determine the specificity of SIase and O16G.

  18. Transgene silencing of sucrose synthase in alfalfa stem vascular tissue by a truncated phosphoenolpyruvate carboxylase: sucrose synthase construct

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An important role of sucrose synthase (SUS, EC 2.4.1.13) in plants is to provide UDP-glucose needed for cellulose synthesis in cell walls. We examined if over-expressing SUS in alfalfa (Medicago sativa L.) would increase cellulose content of stem cell walls. Alfalfa plants were transformed with two ...

  19. Effect of protic ionic liquid on the volumetric properties and taste behaviour of sucrose.

    PubMed

    Singh, Vickramjeet; Chhotaray, Pratap K; Gardas, Ramesh L

    2015-02-15

    The volumetric properties and taste behaviour of sucrose in aqueous solutions of a protic ionic liquid (3-hydroxypropylammonium acetate) have been studied at temperatures, T=(293.15-318.15)K and at atmospheric pressure. Apparent molar volumes, V2,ϕ, apparent specific volumes, ASV, apparent molar isentropic compressibilities, Ks,2,ϕ, and apparent specific isentropic compressibilities, ASIC, were calculated from measured density, ρ and speed of sound, u data. Partial molar volumes, V2(°), and partial molar isentropic compressibilities, Ks,2(°) at infinite dilution, transfer parameters (ΔtV2(°) and ΔtKs,2(°)), expansion coefficients, [(∂V2(°)/∂T)P and (∂(2)V2(°)/∂T(2))P], interaction coefficients, (YAB and YABB) and hydration numbers, Nw, were also evaluated and discussed in terms of solute-cosolute interactions. Further, the effect of protic ionic liquid on the taste behaviour of sucrose has been discussed from ASV and ASIC parameters, as these parameters, which are sensitive to solvation behaviour of solute, are divided into four basic taste qualities occupying certain ranges.

  20. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  1. Aspects of sucrose transport in stem parenchyma of sweet sorghum. [Sorghum bicolor

    SciTech Connect

    Lingle, S.E.

    1987-08-01

    Sweet sorghum (Sorghum bicolor (L.) Moench) is a sucrose-storing crop with a storage tissue anatomically similar to that of sugarcane (Saccharum spp.). However, recent evidence suggests that sweet sorghum may be biochemically different from sugarcane. /sup 14/C-sucrose uptake was studied in excised tissue discs from fully-elongated internodes of Rio sweet sorghum. Washout studies gave results consistent with a 3 compartment system. After 3 hours of uptake, most of the /sup 14/C was found in the vacuole compartment, and was determined by HPLC to be sucrose. Total sucrose uptake consisted of a PCMBS-sensitive (active) and a PCMBS-insensitive (passive) component. Active sucrose uptake had a pH optimum of 4.5. Total sucrose uptake was negatively correlated with the internal sucrose content of the tissue. Fructosyl-labelled /sup 14/C-sucrose was not randomized during uptake, suggesting that sucrose cleavage is not a requirement for sucrose uptake in sweet sorghum. This data suggests that in sweet sorghum, sucrose is transported intact by a specific carrier, as opposed to the sucrose-cleavage-and-resynthesis transport system that apparently operates in sugarcane.

  2. Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

    ERIC Educational Resources Information Center

    Belke, Terry W.; Duncan, Ian D.; Pierce, W. David

    2006-01-01

    Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

  3. 77 FR 18827 - Draft Guidance for Industry on Bioequivalence Recommendations for Iron Sucrose Injection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ... Recommendations for Iron Sucrose Injection; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice... industry entitled ``Bioequivalence Recommendations for Iron Sucrose.'' The recommendations provide specific...) for iron sucrose injection. DATES: Although you can comment on any guidance at any time (see 21 CFR...

  4. Alkaline and alkaline earth metal phosphate halides and phosphors

    DOEpatents

    Lyons, Robert Joseph; Setlur, Anant Achyut; Cleaver, Robert John

    2012-11-13

    Compounds, phosphor materials and apparatus related to nacaphite family of materials are presented. Potassium and rubidium based nacaphite family compounds and phosphors designed by doping divalent rare earth elements in the sites of alkaline earth metals in the nacaphite material families are descried. An apparatus comprising the phosphors based on the nacaphite family materials are presented herein. The compounds presented is of formula A.sub.2B.sub.1-yR.sub.yPO.sub.4X where the elements A, B, R, X and suffix y are defined such that A is potassium, rubidium, or a combination of potassium and rubidium and B is calcium, strontium, barium, or a combination of any of calcium, strontium and barium. X is fluorine, chlorine, or a combination of fluorine and chlorine, R is europium, samarium, ytterbium, or a combination of any of europium, samarium, and ytterbium, and y ranges from 0 to about 0.1.

  5. Individual Differences Among Children in Sucrose Detection Thresholds

    PubMed Central

    Joseph, Paule Valery; Reed, Danielle R.; Mennella, Julie A.

    2016-01-01

    Background Little research has focused on whether there are individual differences among children in their sensitivity to sweet taste and, if so, the biological correlates of such differences. Objectives Our goal was to understand how variations in children’s sucrose detection thresholds relate to their age and gender, taste genotype, body composition, and dietary intake of added sugars. Methods Sucrose detection thresholds in 7- to 14-year-old children were tested individually using a validated, two-alternative, forced-choice, paired-comparison tracking method. Five genetic variants of taste genes were assayed: TAS1R3 and GNAT3 (sweet genes; one variant each) and the bitter receptor gene TAS2R38 (three variants). All children were measured for body weight and height. A subset of these children were measured for the percentage of body fat and waist circumference and provided added sugar intake by 24-hour dietary recall. Results Sucrose thresholds ranged from 0.23 to 153.8 mM with most of the children completing the threshold task (216/235; 92%). Some children were biologically related (i.e., siblings), and for the genetic analysis, one sibling from each family was studied. Variants in the bitter but not the sweet genes were related to sucrose threshold and sugar intake; children with two bitter-sensitive alleles could detect sucrose at lower concentrations (F(2,165) = 4.55, p = .01; rs1726866) and reported eating more added sugar (% kcal; F(2, 62) = 3.64, p = .03) than did children with less sensitive alleles. Age, gender, and indices of obesity also were related to child-to-child differences in sucrose threshold; girls were more sensitive than boys (t(214) = 2.0, p = .05), older children were more sensitive than younger children (r(214) = −.16, p = .02), and fatter (r(84) = −.22, p = .05) or more centrally obese children (r(84) = −.26, p = .02) were more sensitive relative to others. Discussion Inborn differences in bitter sensitivity may affect childhood

  6. Chemical degradation mechanisms of membranes for alkaline membrane fuel cells

    SciTech Connect

    Choe, Yoong-Kee; Henson, Neil J.; Kim, Yu Seung

    2015-12-31

    Chemical degradation mechanisms of membranes for alkaline membrane fuel cells have been investigated using density functional theory (DFT). We have elucidated that the aryl-ether moiety of membranes is one of the weakest site against attack of hydroxide ions. The results of DFT calculations for hydroxide initiated aryl-ether cleavage indicated that the aryl-ether cleavage occurred prior to degradation of cationic functional group. Such a weak nature of the aryl-ether group arises from the electron deficiency of the aryl group as well as the low bond dissociation energy. The DFT results suggests that removal of the aryl-ether group in the membrane should enhance the stability of membranes under alkaline conditions. In fact, an ether fee poly(phenylene) membrane exhibits excellent stability against the attack from hydroxide ions.

  7. Effect of alkaline treatment on the characterization of zalacca midrib wastes fibers

    NASA Astrophysics Data System (ADS)

    Raharjo, Wahyu Purwo; Soenoko, Rudy; Purnowidodo, Anindito; Choiron, Mochammad Agus; Triyono

    2016-03-01

    Nowadays, the need for new materials is urgent due to the scarcity of conventional materials and energy resources. The environmental issue requires materials which are biodegradable. There are many composites, arranged from synthetic fibers and matrix, which cannot be recyclable after their lifetime. In this research, the utilization potency of zalacca midrib wastes for their fibers as composite reinforcement were investigated, especially after the alkaline treatment to improve their characteristics. The influence of alkaline treatment on the density, functional groups of the fiber surface, thermal stability and crystallinity were measured and/or analyzed by linear-density-and-diameter-calculation, FTIR, TGA-DTA and XRD, respectively. The result showed that the zalacca midrib fibers had lower density than synthetic fibers and several natural fibers. Analysis of FTIR spectra indicated that the alkaline treatment of NaOH slightly raised their density because it removed several functional groups which attributed to the hemicellulose and lignin. TGA-DTA analysis indicated that zalacca fibers had good thermal stability until temperature of 220°C and it was improved by alkaline treatment. XRD analysis showed that the crystallinity of zalacca fibers was higher than several natural fibers like rice straw, sorghum stem and wheat straw fibers. Their crystallinity index was higher than wheat straw fiber. The alkaline treatment increases the crystallinity and crystallinity index rather than untreated fibers.

  8. The phase diagram of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/sucrose in the dry state. Sucrose substitution for water in lamellar mesophases.

    PubMed

    Hentschel, M; Miethe, P; Meyer, H W

    1989-04-14

    The phase diagram of the binary system, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/sucrose, was determined by DSC. In contrast to dry DPPC, which exhibits chain melting at 342.5 K, the main feature of the DPPC/sucrose system is eutectic melting at 320 K. This was supported earlier by Crowe, J.H., Crowe, L.M. and Chapman, D. (Science 223 (1984) 701-703), who reported a drastic decrease in the chain-melting temperature of the dry lipid in the presence of some mono- and disaccharides. Electron microscopy suggests that the phase structures on either side of the phase transition are of the lamellar type. Definite sugar saturation concentrations can be derived from this phase diagram. Up to about 17 mol% sucrose, i.e., 1 mol of sucrose per 5 mol of lipid is adopted by DPPC in the low-temperature phase Lc. In the high-temperature phase Lm the saturation concentration is well above 90 mol% sucrose at 320 K (eutectic point) but decreases with increasing temperature. The lower limit of 50 mol% sucrose is reached at 455 K. At this temperature, peritectic melting of sucrose occurs. Because of some similarities in the phase diagrams of DPPC/sucrose and DPPC/water, it is possible to understand the sucrose substitution for water in dry lamellar mesophases.

  9. Efficient microwave assisted synthesis of novel 1,2,3-triazole-sucrose derivatives by cycloaddition reaction of sucrose azides and terminal alkynes.

    PubMed

    Potewar, Taterao M; Petrova, Krasimira T; Barros, M Teresa

    2013-09-20

    Novel 1-(1',2,3,3',4,4',6-hepta-O-acetyl-6'-deoxy-sucros-6'-yl)-4-substituted-1,2,3-triazoles were synthesized by microwave assisted copper catalyzed 1,3-dipolar cycloaddition of sucrose derived azides with terminal alkynes in excellent yields and in short reaction times. The compound 1',2,3,3',4,4',6-hepta-O-acetyl-6'-azido-6'-deoxy-sucrose was regioselectively synthesized from sucrose by improved procedure and used for the cycloadditions. By combining carbohydrate and 1,2,3-triazole structural motifs, a library of 1,2,3-triazole-sucrose conjugates have been obtained.

  10. Genome-wide interacting effects of sucrose and herbicide-mediated stress in Arabidopsis thaliana: novel insights into atrazine toxicity and sucrose-induced tolerance

    PubMed Central

    Ramel, Fanny; Sulmon, Cécile; Cabello-Hurtado, Francisco; Taconnat, Ludivine; Martin-Magniette, Marie-Laure; Renou, Jean-Pierre; El Amrani, Abdelhak; Couée, Ivan; Gouesbet, Gwenola

    2007-01-01

    Background Soluble sugars, which play a central role in plant structure and metabolism, are also involved in the responses to a number of stresses, and act as metabolite signalling molecules that activate specific or hormone-crosstalk transduction pathways. The different roles of exogenous sucrose in the tolerance of Arabidopsis thaliana plantlets to the herbicide atrazine and oxidative stress were studied by a transcriptomic approach using CATMA arrays. Results Parallel situations of xenobiotic stress and sucrose-induced tolerance in the presence of atrazine, of sucrose, and of sucrose plus atrazine were compared. These approaches revealed that atrazine affected gene expression and therefore seedling physiology at a much larger scale than previously described, with potential impairment of protein translation and of reactive-oxygen-species (ROS) defence mechanisms. Correlatively, sucrose-induced protection against atrazine injury was associated with important modifications of gene expression related to ROS defence mechanisms and repair mechanisms. These protection-related changes of gene expression did not result only from the effects of sucrose itself, but from combined effects of sucrose and atrazine, thus strongly suggesting important interactions of sucrose and xenobiotic signalling or of sucrose and ROS signalling. Conclusion These interactions resulted in characteristic differential expression of gene families such as ascorbate peroxidases, glutathione-S-transferases and cytochrome P450s, and in the early induction of an original set of transcription factors. These genes used as molecular markers will eventually be of great importance in the context of xenobiotic tolerance and phytoremediation. PMID:18053238

  11. Sucrose Monoester Micelles Size Determined by Fluorescence Correlation Spectroscopy (FCS)

    PubMed Central

    Sanchez, Susana A.; Gratton, Enrico; Zanocco, Antonio L.; Lemp, Else; Gunther, German

    2011-01-01

    One of the several uses of sucrose detergents, as well as other micelle forming detergents, is the solubilization of different membrane proteins. Accurate knowledge of the micelle properties, including size and shape, are needed to optimize the surfactant conditions for protein purification and membrane characterization. We synthesized sucrose esters having different numbers of methylene subunits on the substituent to correlate the number of methylene groups with the size of the corresponding micelles. We used Fluorescence Correlation Spectroscopy (FCS) and two photon excitation to determine the translational D of the micelles and calculate their corresponding hydrodynamic radius, Rh. As a fluorescent probe we used LAURDAN (6-dodecanoyl-2-dimethylaminonaphthalene), a dye highly fluorescent when integrated in the micelle and non-fluorescent in aqueous media. We found a linear correlation between the size of the tail and the hydrodynamic radius of the micelle for the series of detergents measured. PMID:22216230

  12. Cryoprotection by Glucose, Sucrose, and Raffinose to Chloroplast Thylakoids 1

    PubMed Central

    Lineberger, R. Daniel; Steponkus, Peter L.

    1980-01-01

    Differential cryoprotection is afforded to chloroplast thylakoids against freeze-induced uncoupling of cyclic photophosphorylation by equimolar concentrations of glucose, sucrose, and raffinose. This differential protective effect appears to be due to nonideal activity-concentration profiles exhibited by the sugars during freezing. When cryoprotection is analyzed as a function of the mole fraction of NaCl to which the membranes are exposed during freezing, the pattern of protection to cyclic photophosphorylation and its component reactions is not dependent upon the chemical identity of the protective solute. Cryoprotective efficiency of glucose, sucrose, and raffinose can be accounted for by proposing an activity dependent alteration in the freezing environment rather than specific solute-membrane interactions. PMID:16661177

  13. Roles of alkaline phosphatase and labile internal mineral in matrix vesicle-mediated calcification. Effect of selective release of membrane-bound alkaline phosphatase and treatment with isosmotic pH 6 buffer.

    PubMed

    Register, T C; McLean, F M; Low, M G; Wuthier, R E

    1986-07-15

    The roles of alkaline phosphatase and labile internal mineral in matrix vesicle-mediated mineralization have been studied by selectively releasing the enzyme from a wide variety of matrix vesicle preparations using treatment with a bacterial phosphatidylinositol-specific phospholipase C and by demineralization of the vesicles using isosmotic pH 6 buffer. Following depletion of 50-90% of the alkaline phosphatase activity or treatment with citrate buffer, the vesicles were tested for their ability to accumulate 45Ca2+ and 32Pi from a synthetic cartilage lymph. Removal of alkaline phosphatase by phospholipase C treatment caused two principal effects, depending on the matrix vesicle preparation. In rapidly mineralizing vesicle fractions which did not require organic phosphate esters (Po) to accumulate mineral ions, release of alkaline phosphatase had only a minor effect. In slowly mineralizing vesicles preparations or those dependent on Po substrates for mineral ion uptake, release of alkaline phosphatase caused significant loss of mineralizing activity. The activity of rapidly calcifying vesicles was shown to be dependent on the presence of labile internal mineral, as demonstrated by major loss in activity when the vesicles were decalcified by various treatments. Ion uptake by demineralized vesicles or those fractionated on sucrose step gradients required Po and was significantly decreased by alkaline phosphatase depletion. Uptake of Pi, however, was not coupled with hydrolysis of the Po substrate. These findings argue against a direct role for alkaline phosphatase as a porter in matrix vesicle Pi uptake, contrary to previous postulates. The results emphasize the importance of internal labile mineral in rapid uptake of mineral ions by matrix vesicles.

  14. Low-temperature electrolytic coloration and spectral properties of sucrose crystals.

    PubMed

    Gu, Hongen; Tian, Pin; Guo, Meili; Li, Yutong; Hao, Xiaoqing

    2012-06-01

    Sucrose crystals are colored electrolytically at low temperatures and various voltages by using a pointed cathode and a flat anode. Caramels, carbonyl compounds, glycosylamines and free radicals are produced in colored sucrose crystals. No obvious characteristic absorption band in UV and visible wavelength regions is observed in absorption spectrum of uncolored sucrose crystal. Intense characteristic absorption bands of glycosylamines, carbonyl compounds and caramels are observed in absorption spectra of colored sucrose crystals. Production of caramels, carbonyl compounds, glycosylamines and free radicals are explained. Current-time curve for electrolytic coloration of sucrose crystal and its relationship with electrolytic coloration process are given.

  15. Low-temperature electrolytic coloration and spectral properties of sucrose crystals

    NASA Astrophysics Data System (ADS)

    Gu, Hongen; Tian, Pin; Guo, Meili; Li, Yutong; Hao, Xiaoqing

    2012-06-01

    Sucrose crystals are colored electrolytically at low temperatures and various voltages by using a pointed cathode and a flat anode. Caramels, carbonyl compounds, glycosylamines and free radicals are produced in colored sucrose crystals. No obvious characteristic absorption band in UV and visible wavelength regions is observed in absorption spectrum of uncolored sucrose crystal. Intense characteristic absorption bands of glycosylamines, carbonyl compounds and caramels are observed in absorption spectra of colored sucrose crystals. Production of caramels, carbonyl compounds, glycosylamines and free radicals are explained. Current-time curve for electrolytic coloration of sucrose crystal and its relationship with electrolytic coloration process are given.

  16. Sucrose increases calcium-dependent protein kinase and phosphatase activities in potato plants.

    PubMed

    Raíces, M; MacIntosh, G C; Ulloa, R M; Gargantini, P R; Vozza, N F; Téllez-Inón, M T

    2003-09-01

    The effect of sucrose on tuber formation, calcium-dependent protein kinase (CDPK) and phosphatase activities was analysed using in vitro cultured potato plants. In short treatments, sucrose induced CDPK and phosphatase activities. In long treatments, sucrose induced tuber formation in the absence of other tuber inducing stimuli. Sorbitol caused a minor increase in CDPK activity and affected plant morphology but did not induce tuber development. The addition of the protein kinase inhibitor Staurosporine precluded sucrose-induced tuberization. Altogether, our results suggest that phosphorylation/dephosphorylation events are involved in sucrose-induced tuber development.

  17. Closed type alkaline storage battery

    SciTech Connect

    Hayama, H.

    1980-06-10

    The alkaline storage battery employs a metallic hat shaped terminal closure which has a piercing needle as well as a puncturable metallic diaphragm positioned below the piercing needle. The needle is fixed by caulking at its peripheral edge portion to a edge of the closure. A comparatively thick and hard metal plate is placed on the inner surface of the diaphragm and is applied to an open portion of a tubular metallic container which has a battery element. A peripheral edge portion of the closure, the diaphragm and the metallic plate are clamped in airtight relationship through a packing between the caulked end portion and an inner annular step portion of the metallic container of the battery. A lead wire extends from one polarity electrode of the battery element and is connected to a central portion of the metallic plate.

  18. Central melanocortins regulate the motivation for sucrose reward.

    PubMed

    Pandit, Rahul; van der Zwaal, Esther M; Luijendijk, Mieneke C M; Brans, Maike A D; van Rozen, Andrea J; Oude Ophuis, Ralph J A; Vanderschuren, Louk J M J; Adan, Roger A H; la Fleur, Susanne E

    2015-01-01

    The role of the melanocortin (MC) system in feeding behavior is well established. Food intake is potently suppressed by central infusion of the MC 3/4 receptor agonist α-melanocyte stimulating hormone (α-MSH), whereas the MC 3/4 receptor inverse-agonist Agouti Related Peptide (AGRP) has the opposite effect. MC receptors are widely expressed in both hypothalamic and extra-hypothalamic brain regions, including nuclei involved in food reward and motivation, such as the nucleus accumbens (NAc) and the ventral tegmental area. This suggests that MCs modulate motivational aspects of food intake. To test this hypothesis, rats were injected intracerebroventricularly with α-MSH or AGRP and their motivation for sucrose was tested under a progressive ratio schedule of reinforcement. Food motivated behavior was dose-dependently decreased by α-MSH. Conversely, AGRP increased responding for sucrose, an effect that was blocked by pretreatment with the dopamine receptor antagonist α-flupenthixol. In contrast to progressive ratio responding, free intake of sucrose remained unaltered upon α-MSH or AGRP infusion. In addition, we investigated whether the effects of α-MSH and AGRP on food motivation were mediated by the NAc shell. In situ hybridization of MC3 and MC4 receptor expression confirmed that the MC4 receptor was expressed throughout the NAc, and injection of α-MSH and AGRP into the NAc shell caused a decrease and an increase in motivation for sucrose, respectively. These data show that the motivation for palatable food is modulated by MC4 receptors in the NAc shell, and demonstrate cross-talk between the MC and dopamine system in the modulation of food motivation.

  19. Steroid hormone excretion is enhanced by sucrose feeding to rats

    SciTech Connect

    Kruger, T.C.; Hsu, H.; Saunders, J.P.; Kim, S.S.; Given-Proctor, J.; Ahrens, R.A.

    1986-03-01

    The hypothesis tested was that feeding rats sucrose rather than invert sugar (50:50 mixture of glucose and fructose) or cornstarch would result in a more rapid excretion of intravenously injected 1,2-/sup 3/H aldosterone or 1,2,6,7-/sup 3/H cortisol. The three carbohydrate sources provided 45% of dietary energy when fed, respectively, to one of three groups of 10 male, Sprague Dawley rats. After 4 or 8 weeks of ad lib feeding of the three diets 5 ..mu..CI of /sup 3/H-labeled hormones were injected intravenously and % recovery in urine and feces was measured for 4 days by liquid scintillation counting. Nearly 90% of the /sup 3/H injected as 1,2-/sup 3/H aldosterone was recovered over 4 days in the excreta of the sucrose fed rats. This recovery of /sup 3/H from aldosterone was significantly greater (P < 0.01) than when invert sugar (65%) or cornstarch (60%) were fed. The recovery of /sup 3/H from intravenously injected 1,2,6,7-/sup 3/H cortisol followed a similar pattern. The authors anticipate that the excretion of all metabolic end products and xenobiotics excreted as glucuronides would be enhanced by sucrose feeding. Oxocarbonium ions from the glucose portion of sucrose digestion in the mammalian small intestine are thought to compete with oxocarbonium ions from the glucuronic acid portion of glucuronide hydrolysis. Such competition may slow glucuronide hydrolysis and promote glucuronide excretion, including the glucuronides derived from aldosterone and cortisol.

  20. Cultivation of marine shrimp in biofloc technology (BFT) system under different water alkalinities.

    PubMed

    Piérri, V; Valter-Severino, D; Goulart-de-Oliveira, K; Manoel-do-Espírito-Santo, C; Nascimento-Vieira, F; Quadros-Seiffert, W

    2015-08-01

    The aim of this study was to evaluate the influence of different levels of alkalinity for the superintensive cultivation of marine shrimp Litopenaeus vannamei in biofloc system. A total of 12 experimental circular units of 1000L were used supplied with 850L water from a nursery, populated at a density of 165 shrimps.m-3 and average weight of 5.6 g. The treatments, in triplicate, consisted in four levels of alkalinity in the water: 40, 80, 120 and 160 mg.L-1 of calcium carbonate. To correct the alkalinity was used calcium hydroxide (CaOH). It was observed a decrease in pH of the water in the treatments with lower alkalinity (p<0.05). The total suspended settleable solids were also lower in the treatment of low alkalinity. No significant difference was observed in other physico-chemical and biological parameters in the water quality assessed, as well as the zootechnical parameters of cultivation between treatments (p≥0.05). The results of survival and growth rate of shrimps were considered suitable for the cultivation system used in the different treatments. The cultivation of marine shrimp Litopenaeus vannamei in biofloc at density of 165 shrimps.m-3 can be performed in waters with alkalinity between 40 and 160 mg.L-1 of CaCO3, without compromising the zootechnical indexes of cultivation.

  1. Heterotrophic cultivation of Chlorella pyrenoidosa using sucrose as the sole carbon source by co-culture with Rhodotorula glutinis.

    PubMed

    Wang, Shikai; Wu, Yong; Wang, Xu

    2016-11-01

    Heterotrophic cultivation of microalgae is a feasible alternative strategy to avoid the light limitation of photoautotrophic culture, but the heterotrophic utilization of disaccharides is difficult for microalgae. Aimed at this problem, a co-culture system was developed by mix culture of C. pyrenoidosa and R. glutinis using sucrose as the sole carbon source. In this system, C. pyrenoidosa could utilize glucose and fructose which were hydrolyzed from sucrose by R. glutinis. The highest specific growth rate and final cell number proportion of algae was 1.02day(-1) and 45%, respectively, when cultured at the initial algal cell number proportion of 95.24% and the final algal cell density was 111.48×10(6)cells/mL. In addition, the lipid content was also promoted due to the synergistic effects in mix culture. This study provides a novel approach using sucrose-riched wastes for the heterotrophic culture of microalgae and may effectively decrease the cost of carbon source.

  2. Diffusion of Trehalose and Sucrose in Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Feick, E.; von Meerwall, E.; Ekdawi, N.; de Pablo, J.

    2000-10-01

    Trehalose is emerging as superior substitute for sucrose in solution as a cryoprotectant, e. g., to preserve organs destined for transplantation. We have used the proton NMR pulsed-gradient spin-echo method between T = 30 and 85 deg. C to study the self-diffusion of solvent and solute in aqueous solutions of these molecules as function of their concentration, c. We find that both solute molecules diffuse substantially more slowly than water at corresponding c and T; that addition of water accelerates solute diffusion more rapidly than that of water; and that while at a given c and T water diffusion is insensitive to solute identity, trehalose diffusion is slower than sucrose diffusion. The latter effect increases with c, approaching a factor of two at the highest c. In these respects our results correspond closely to those of our extensive numerical simulations of these systems. Free-volume theory is employed to explore the cooperative kinetic interactions between solvent and solutes, and to account tentatively for part of the superiority of trehalose to sucrose as preservation agent. Differences in crystallization behavior also seem to be involved.

  3. Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.

    PubMed

    Allan, Sandra A

    2011-06-01

    Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their lives. Development of toxic baits focusing on this carbohydrate-seeking behavior may potentially contribute to localized control. In the present study, ten insecticides were fed to female Culex quinquefasciatus, Anopheles quadrimaculatus, and Aedes taeniorhynchus in a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles, neonicotinoids, and macrocyclic lactones) were selected for comparison with commercial formulations used to facilitate incorporation of active ingredients into aqueous sucrose solutions. Sucrose as a phagostimulant significantly enhanced mortality to toxicants. In general, the most effective active ingredients were fipronil, deltamethrin and imidacloprid, followed by spinosad, thiamethoxam, bifenthrin, permethrin, and cyfluthrin. The least effective ingredients were chlorfenapyr and ivermectin. For some of the ingredients tested, Cx. quinquefasciatus was the least susceptible species. One-day-old male Cx. quinquefasciatus were more susceptible than females; however, no differences existed between one- and seven-day-old mosquitoes. There were no differences in susceptibility between unfed and gravid ten-day-old female Cx. quinquefasciatus to bifenthrin. In conclusion, several pesticides from different classes of compounds have potential for use in development of toxic baits for mosquitoes.

  4. Amphiphilic copolymers of sucrose methacrylate and acrylic monomers: bio-based materials from renewable resource.

    PubMed

    de Oliveira, Heitor F N; Felisberti, Maria Isabel

    2013-04-15

    Regioselective sucrose 1'-O-methacrylate obtained by transesterification catalyzed by Proteinase-N was copolymerized with hydrophilic N-isopropylacrylamide and hydrophobic methyl methacrylate in different molar ratios by free radical polymerization. The copolymers were characterized by (13)C nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry and thermogravimetry. Solubility and phase behavior of aqueous solutions were also investigated. The glass transition of the copolymers presents a positive deviation from the values of the homopolymers due to the high density of inter and intramolecular hydrogen bonding. Their solubility is strongly dependent on the composition. Copolymers poor in methyl methacrylate are water soluble, while copolymers richer in methyl methacrylate behaves as hydrogel. These hydrogels are not chemically crosslinked and their form can be design prior swelling by the conventional processing methods, such as solvent casting and extrusion for instance. Copolymers of N-isopropylacrylamide are water soluble and their aqueous solutions present a lower critical solution temperature behavior forming thermoreversible hydrogels.

  5. Effect of dietary copper and sucrose on catecholamine concentrations in the adrenal medulla

    SciTech Connect

    Koo, S.I.; Peterson, D.F.; Mason, P.A. KCOM, Kirksville, MO Air Force/SAM/RZP, Brooks AFB, TX )

    1991-03-11

    The severity of copper (Cu) deficiency in the rat is enhanced by dietary sucrose. Possible interactive effects of Cu status and sucrose on catecholamine concentrations in the adrenal medulla were investigated in Cu deficient rats fed a diet were investigated in Cu deficient rats fed a diet containing either glucose or sucrose, as compared with respective Cu-adequate controls. Catecholamines were analyzed by an HPLC method using 3,4-dihydroxybenxylamine as the internal standard. Cu deficiency caused pronounced decreases in norepinephrine and epinephrine, with no significant effect on dopamine, as expressed in nmoles/mg tissue. Dietary sucrose showed no appreciable effect on catecholamines in the adrenal medulla. The adrenal glands were markedly enlarged in Cu-deficient rats, whether fed glucose or sucrose. Adrenal weights were not affected by dietary sucrose. Data indicate that the increased severity of copper deficiency due to sucrose feeding is not associated with changes in adrenal catecholamine output.

  6. Evolution of alkaline phosphatases in primates.

    PubMed Central

    Goldstein, D J; Rogers, C; Harris, H

    1982-01-01

    Alkaline phosphatase [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] in placenta, intestine, liver, kidney, bone, and lung from a variety of primate species has been characterized by quantitative inhibition, thermostability, and immunological studies. Characteristic human placental-type alkaline phosphatase occurs in placentas of great apes (chimpanzee and orangutan) but not in placentas of other primates, including gibbon. It is also present in trace amounts in human lung but not in lung or other tissues of various Old and New World monkeys. However, a distinctive alkaline phosphatase resembling it occurs in substantial amounts in lungs from Old World monkeys but not New World monkeys. It appears that duplication of alkaline phosphatase genes and mutations of genetic elements controlling their tissue expression have occurred relatively recently in mammalian evolution. Images PMID:6950431

  7. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  8. Gap junction structures. V. Structural chemistry inferred from X-ray diffraction measurements on sucrose accessibility and trypsin susceptibility.

    PubMed

    Makowski, L; Caspar, D L; Phillips, W C; Goodenough, D A

    1984-04-15

    X-ray diffraction patterns have been recorded from partially oriented specimens of gap junctions isolated from mouse liver and suspended in sucrose solutions of different concentration and thus of different electron density. Analysis of these diffraction patterns has shown that sucrose is excluded from the 6-fold rotation axis of the junction lattice for a length of about 100 A. This indicates that the aqueous channel of the junctions is in the closed, high resistance state in these preparations. Mapping of the sucrose-accessible space in the junction indicates that the cross-sectional area of the channel entrance on the cytoplasmic side of the membrane could be up to five times larger than the area of the transmembrane channel. Sucrose does not penetrate more than 20 A into the membrane along the channel. Apparently the aqueous channel, 8 to 10 A in radius for most of its length, is narrowed or blocked by a small feature about 50 A from the center of the gap. Very close interactions exist between the gap junction protein and the lipid polar head groups on the cytoplasmic surface of the membrane. In this region, the protein intercalates between the polar head groups. These results suggest that the gap junction protein may have a functional two-domain structure. One domain, with a molecular weight of about 15,000, spans one bilayer and half of the gap and is contained largely within a radius of 25 A from the 6-fold axis. The second domain is smaller and occupies the cytoplasmic surface of the gap junction membrane. Trypsin digestion removes about 4000 Mr from the cytoplasmic surface domain of the junction protein. Most of the material susceptible to trypsin digestion is located more than 28 A from the 6-fold axis.

  9. Intermittent access to a sucrose solution for rats causes long-term increases in consumption.

    PubMed

    Eikelboom, Roelof; Hewitt, Randelle

    2016-10-15

    Intermittent access to palatable food can elevate consumption beyond an animal's immediate needs. If adult male rats (with ad lib access to food and water) are provided with a 4% sucrose solution, daily sucrose consumption is determined by the sucrose access schedule: access that is intermittent leads to high levels of consumption. In Experiment 1, sucrose solutions were first provided continuously or every second, third, or fourth day for 23.5h over 49days. Continuous-access sucrose consumption averaged 102g per day, while that for access every fourth day averaged 294g. Daily consumption averages for access every second and third day fell between these two extremes. When all rats were then given alternate-day access to sucrose for 24days in Phase II, the previously established consumption differences were maintained. Body weight was unaffected by sucrose access; rats adjusted their food consumption so that total calorie intake remained constant. In Experiment 2, compared to continuous 4% sucrose solution access, access every third day markedly elevated daily sucrose consumption after only four sucrose exposures. With this shorter Phase I, sucrose intake in the continuous group increased markedly when in Phase II all rats were given alternate day access. In Experiment 3, a lick-by-lick analysis of the difference in sucrose consumption between access every third day and continuous access revealed that all rats were consuming a similar number of sucrose meals; however, the meals were larger both in the first hour and over the whole 24h with intermittent access. This suggests a change in satiety as a mechanism underlying sucrose consumption difference.

  10. Engineering topology and kinetics of sucrose metabolism in Saccharomyces cerevisiae for improved ethanol yield.

    PubMed

    Basso, Thiago O; de Kok, Stefan; Dario, Marcelo; do Espirito-Santo, Júlio Cézar A; Müller, Gabriela; Schlölg, Paulo S; Silva, Carlos P; Tonso, Aldo; Daran, Jean-Marc; Gombert, Andreas K; van Maris, Antonius J A; Pronk, Jack T; Stambuk, Boris U

    2011-11-01

    Sucrose is a major carbon source for industrial bioethanol production by Saccharomyces cerevisiae. In yeasts, two modes of sucrose metabolism occur: (i) extracellular hydrolysis by invertase, followed by uptake and metabolism of glucose and fructose, and (ii) uptake via sucrose-proton symport followed by intracellular hydrolysis and metabolism. Although alternative start codons in the SUC2 gene enable synthesis of extracellular and intracellular invertase isoforms, sucrose hydrolysis in S. cerevisiae predominantly occurs extracellularly. In anaerobic cultures, intracellular hydrolysis theoretically enables a 9% higher ethanol yield than extracellular hydrolysis, due to energy costs of sucrose-proton symport. This prediction was tested by engineering the promoter and 5' coding sequences of SUC2, resulting in predominant (94%) cytosolic localization of invertase. In anaerobic sucrose-limited chemostats, this iSUC2-strain showed an only 4% increased ethanol yield and high residual sucrose concentrations indicated suboptimal sucrose-transport kinetics. To improve sucrose-uptake affinity, it was subjected to 90 generations of laboratory evolution in anaerobic, sucrose-limited chemostat cultivation, resulting in a 20-fold decrease of residual sucrose concentrations and a 10-fold increase of the sucrose-transport capacity. A single-cell isolate showed an 11% higher ethanol yield on sucrose in chemostat cultures than an isogenic SUC2 reference strain, while transcriptome analysis revealed elevated expression of AGT1, encoding a disaccharide-proton symporter, and other maltose-related genes. After deletion of both copies of the duplicated AGT1, growth characteristics reverted to that of the unevolved SUC2 and iSUC2 strains. This study demonstrates that engineering the topology of sucrose metabolism is an attractive strategy to improve ethanol yields in industrial processes.

  11. Nitrosative stress and apoptosis in non-anemic healthy rats induced by intravenous iron sucrose similars versus iron sucrose originator.

    PubMed

    Toblli, Jorge E; Cao, Gabriel; Angerosa, Margarita

    2015-04-01

    Iron can both induce and inhibit nitrosative stress. Intracellular iron levels play an important role in nitric oxide (NO(•)) signaling mechanisms. Depending on various factors, such as the cell's redox state and transition metal levels, NO(•) generation may lead to lipid peroxidation and DNA damage as well as both anti- and pro-apoptotic effects. Administration of intravenous iron sucrose originator (IS(ORIG)) has been shown not to cause significant tyrosine nitration or significantly increased caspase 3 levels in non-anemic rats. In this study, the potential of several marketed iron sucrose similars (ISSs) to induce tyrosine nitration and caspase 3 expression in non-anemic rats was assessed. Although the physico-chemical properties of most of the analyzed ISSs complied with the United States Pharmacopeia for iron sucrose injection, all ISSs resulted in higher levels of tyrosine nitration and increased the expression of caspase 3 versus IS(ORIG). Moreover, significant differences were detected in tissue iron distribution between IS(ORIG)- and ISS-treated animals. In general, ISORIG resulted in higher levels of ferritin deposits versus ISSs whereas ISSs showed higher Prussian blue-stainable iron(III) deposits than IS(ORIG). This result suggests that some iron from ISSs bypassed the tightly regulated pathway through resident macrophages of the liver, spleen and bone marrow thus, ending up in the cellular compartment that favors oxidative and or nitrosative stress as well as apoptosis. The results also confirm that polynuclear iron(III)-oxyhydroxide carbohydrates, such as iron sucrose, cannot be fully characterized by physico-chemical methods alone.

  12. Transforming a fructan:fructan 6G-fructosyltransferase from perennial ryegrass into a sucrose:sucrose 1-fructosyltransferase.

    PubMed

    Lasseur, Bertrand; Schroeven, Lindsey; Lammens, Willem; Le Roy, Katrien; Spangenberg, German; Manduzio, Hélène; Vergauwen, Rudy; Lothier, Jérémy; Prud'homme, Marie-Pascale; Van den Ende, Wim

    2009-01-01

    Fructosyltransferases (FTs) synthesize fructans, fructose polymers accumulating in economically important cool-season grasses and cereals. FTs might be crucial for plant survival under stress conditions in species in which fructans represent the major form of reserve carbohydrate, such as perennial ryegrass (Lolium perenne). Two FT types can be distinguished: those using sucrose (S-type enzymes: sucrose:sucrose 1-fructosyltransferase [1-SST], sucrose:fructan 6-fructosyltransferase) and those using fructans (F-type enzymes: fructan:fructan 1-fructosyltransferase [1-FFT], fructan:fructan 6G-fructosyltransferase [6G-FFT]) as preferential donor substrate. Here, we report, to our knowledge for the first time, the transformation of an F-type enzyme (6G-FFT/1-FFT) into an S-type enzyme (1-SST) using perennial ryegrass 6G-FFT/1-FFT (Lp6G-FFT/1-FFT) and 1-SST (Lp1-SST) as model enzymes. This transformation was accomplished by mutating three amino acids (N340D, W343R, and S415N) in the vicinity of the active site of Lp6G-FFT/1-FFT. In addition, effects of each amino acid mutation alone or in combination have been studied. Our results strongly suggest that the amino acid at position 343 (tryptophan or arginine) can greatly determine the donor substrate characteristics by influencing the position of the amino acid at position 340. Moreover, the presence of arginine-343 negatively affects the formation of neofructan-type linkages. The results are compared with recent findings on donor substrate selectivity within the group of plant cell wall invertases and fructan exohydrolases. Taken together, these insights contribute to our knowledge of structure/function relationships within plant family 32 glycosyl hydrolases and open the way to the production of tailor-made fructans on a larger scale.

  13. Evidence for the presence of a sucrose carrier in immature sugar beet tap roots. [Beta vulgaris L

    SciTech Connect

    Lemoine, R.; Daie, J.; Wyse, R. )

    1988-02-01

    The objectives of this work were to determine the path of phloem unloading and if a sucrose carrier was present in young sugar beet (Beta vulgaris L.) taproots. The approach was to exploit the characteristics of the sucrose analog, 1{prime}-fluorosucrose (F-sucrose) which is a poor substrate for acid invertase but is a substrate for sucrose synthase. Ten millimolar each of ({sup 3}H) sucrose and ({sup 14}C)F-sucrose were applied in a 1:1 ratio to an abraded region of an attached leaf for 6 hours. ({sup 14}C)F-sucrose was translocated and accumulated in the roots at a higher rate than ({sup 3}H)sucrose. This was due to ({sup 3}H)sucrose hydrolysis along the translocation path. Presence of ({sup 3}H)hexose and ({sup 14}C)F-sucrose in the root apoplast suggested apoplastic sucrose unloading with its subsequent hydrolysis. Labeled F-sucrose uptake by root tissue discs exhibited biphasic kinetics and was inhibited by unlabeled sucrose, indicating that immature roots have the ability for carrier-mediated sucrose transport from the apoplast. Collectively, in vivo and in vitro data indicate that despite sucrose hydrolysis by the wall-bound invertase, sucrose hydrolysis is not entirely essential for sugar accumulation in this tissue.

  14. Pontine and thalamic influences on fluid rewards: I. Operant responding for sucrose and corn oil.

    PubMed

    Liang, Nu-Chu; Freet, Christopher S; Grigson, Patricia S; Norgren, Ralph

    2012-01-18

    The reward strength of orosensory sucrose and corn oil was measured using fixed and progressive ratio operant schedules. Because the orosensory effects of the stimuli were of interest, Experiment 1 compared operant responses for sucrose in sham and real feeding rats. The results demonstrated that rats would work for sucrose solutions without the accompanying postingestive effects. Furthermore, the break points for high concentrations of sucrose (1.0 M or 2.0 M) were significantly higher in sham feeding rats than in real feeding controls. Experiment 2 investigated the role of the parabrachial nucleus (PBN) and of the thalamic orosensory area (TOA) in sucrose and corn oil reward. During free access, rats with PBN lesions (PBNx) licked significantly less sucrose solution than their controls, but both groups ingested a similar volume of corn oil emulsion. When an operant was imposed, these same PBNx rats failed to respond for sucrose and continued only modestly for corn oil. In contrast, the TOA lesioned rats (TOAx) showed no impairment in responding for sucrose or corn oil during either the free access or operant sessions. Furthermore, rats with TOA lesions demonstrated significantly higher break points for sucrose than did their controls. Together, the data imply that the PBN but not the TOA is critical for the perception of, or responding to the reward value of sucrose and corn oil.

  15. Expression profiling of sucrose metabolizing genes in Saccharum, Sorghum and their hybrids.

    PubMed

    Ramalashmi, K; Prathima, P T; Mohanraj, K; Nair, N V

    2014-10-01

    Sucrose phosphate synthase (SPS; EC 2.4.1.14), sucrose synthase (SuSy; EC 2.4.1.13) and soluble acid invertase (SAI; EC 3.2.1.26) are key enzymes that regulate sucrose fluxes in sink tissues for sucrose accumulation in sugarcane and sorghum. In this study, the expression profiling of sucrose-related genes, i.e. SPS, SuSy and SAI in two sets of hybrids viz., one from a Sorghum × Saccharum cross and the other from a Saccharum × Sorghum cross, high- and low-sucrose varieties, sweet and grain sorghum lines was carried out using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) at monthly intervals. The results indicated differential expression of the three genes in high- and low-sucrose forms. Expression of SPS and SuSy genes was high in high-sucrose varieties, Saccharum × Sorghum hybrids and sweet sorghum and lower in low-sucrose varieties, Sorghum × Saccharum hybrids and grain sorghum. SAI showed a lower expression in high-sucrose varieties, Saccharum × Sorghum hybrids and sweet sorghum and higher expression in low-sucrose varieties, Sorghum × Saccharum hybrids and the grain sorghum. This study describes the positive association of SPS and SuSy and negative association of SAI on sucrose accumulation. This is the first report of differential expression profiling of SPS, SuSy and SAI in intergeneric hybrids involving sugarcane and sorghum, which opens the possibility for production of novel hybrids with improved sucrose content and with early maturity.

  16. Influence of antioxidant structure on local molecular mobility in amorphous sucrose.

    PubMed

    Liang, Jun; Corradini, Maria G; Ludescher, Richard D

    2014-01-13

    The effect of the antioxidants gallic acid and methyl, propyl, and octyl gallate on the molecular mobility and hydrogen bond network in amorphous sucrose was studied. Solid amorphous sucrose films with and without the addition of antioxidants at a mole ratio of 1:5 (antioxidant/sucrose) were cast from solution onto quartz slides. Local molecular mobility from 0 to 70°C was measured using tryptophan amino acid as a luminescent probe dispersed in the films. Phosphorescence from the tryptophan probe provides spectroscopic characteristics-emission spectrum and lifetime-that are sensitive to changes in molecular mobility induced by the addition of antioxidants. Local molecular mobility detected by tryptophan increased in the following order: sucrose-octyl gallate<sucrose-propyl gallate⩽sucrose-methyl gallate⩽sucrose-gallic acid. The antioxidants also modulated the activation energy for matrix motions that quench the tryptophan phosphorescence in a structure-dependent manner. IR measurements as a function of temperature indicated that hydrogen bond strength in these amorphous films followed a rank order (sucrose-methyl gallate>sucrose-gallic acid>sucrose-propyl gallate>sucrose>sucrose-octyl gallate) that was nearly the reverse of that seen in matrix mobility. Analysis of the differential effects of the antioxidants suggests that the presence of the hydroxyl benzoyl head group increased matrix molecular mobility and hydrogen bond strength while the saturated carbon chain decreased mobility and bond strength. The influence of the carboxyl group on matrix properties was comparable to that of the formyloxy group. These results indicate that the addition of specific functional ingredients such as antioxidants may significantly affect the physical properties and consequently functional properties of amorphous edible films in ways that might condition their use. The observed changes are closely related to the chemical structure of the added species.

  17. Sex-dependent effects of early life inflammatory pain on sucrose intake and sucrose-associated hippocampal Arc expression in adult rats.

    PubMed

    Henderson, Yoko O; Nalloor, Rebecca; Vazdarjanova, Almira; Murphy, Anne Z; Parent, Marise B

    2017-05-01

    We hypothesize that dorsal hippocampal (dHC) neurons, which are critical for episodic memory, form a memory of a meal and inhibit the initiation of the next meal and the amount ingested during that meal. In support, we showed previously that (1) consuming a sucrose meal induces expression of the synaptic plasticity marker activity-regulated cytoskeleton-associated protein (Arc) in dHC neurons and (2) reversible inactivation of these neurons immediately following a sucrose meal accelerates the onset of the next meal and increases the size of that meal. These data suggest that hippocampal-dependent memory inhibits intake; therefore, the following experiments were conducted to determine whether hippocampal-dependent memory impairments are associated with increased intake. We reported recently that one episode of early life inflammatory pain impairs dHC-dependent memory in adult rats. The present study determined whether neonatal inflammatory pain also increases sucrose intake and attenuates sucrose-associated Arc expression. Male and female Sprague-Dawley rats were given an intraplantar injection of the inflammatory agent carrageenan (1%) on the day of birth and sucrose intake and sucrose-associated dHC Arc expression were measured in adulthood. Neonatal inflammatory pain increased sucrose intake in adult female and male rats, decreased sucrose-associated dHC Arc expression in female rats, and tended to have a similar effect on Arc expression in male rats. Neonatal inflammatory pain significantly decreased the interval between two sucrose meals in female but not in male rats. Morphine administration at the time of insult attenuated the effects of injury on sucrose intake. Collectively, these findings indicate that one brief episode of inflammatory pain on the day of birth has a long long-lasting, sex-dependent impact on intake of a palatable food in adulthood.

  18. Process for extracting technetium from alkaline solutions

    DOEpatents

    Moyer, Bruce A.; Sachleben, Richard A.; Bonnesen, Peter V.

    1995-01-01

    A process for extracting technetium values from an aqueous alkaline solution containing at least one alkali metal hydroxide and at least one alkali metal nitrate, the at least one alkali metal nitrate having a concentration of from about 0.1 to 6 molar. The solution is contacted with a solvent consisting of a crown ether in a diluent for a period of time sufficient to selectively extract the technetium values from the aqueous alkaline solution. The solvent containing the technetium values is separated from the aqueous alkaline solution and the technetium values are stripped from the solvent.

  19. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  20. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  1. An Experiment Using Sucrose Density Gradients in the Undergraduate Biochemistry Laboratory.

    ERIC Educational Resources Information Center

    Turchi, Sandra L.; Weiss, Monica

    1988-01-01

    Describes an experiment to be performed in an undergraduate biochemistry laboratory that is based on a gradient centrifugation system employing a simple bench top centrifuge, a freezer, and frozen surcose gradient solution to separate macromolecules and subcellular components. (CW)

  2. Nickel hydroxide deposited indium tin oxide electrodes as electrocatalysts for direct oxidation of carbohydrates in alkaline medium

    NASA Astrophysics Data System (ADS)

    Ganesh, V.; Farzana, S.; Berchmans, Sheela

    In this work, the direct electrochemical oxidation of carbohydrates using nickel hydroxide modified indium tin oxide (ITO) electrodes in alkaline medium is demonstrated; suggesting the feasibility of using carbohydrates as a novel fuel in alkaline fuel cells applications. The chosen monosaccharides are namely glucose and fructose; disaccharides such as sucrose and lactose; and sugar acid like ascorbic acid for this study. ITO electrodes are chemically modified using a hexagonal lyotropic liquid crystalline phase template electrodeposition of nickel. Structural morphology, growth, orientation and electrochemical behaviour of Ni deposits are characterized using SEM, XRD, XPS and cyclic voltammetry (CV), respectively. Further electrochemical potential cycling process in alkaline medium is employed to convert these Ni deposits into corresponding nickel hydroxide modified electrodes. These electrodes are used as novel platform to perform the electrocatalytic oxidation of various carbohydrates in alkaline medium. It was found that bare and Ni coated ITO electrodes are inactive towards carbohydrates oxidation. The heterogeneous rate constant values are determined and calculated to be two orders of magnitude higher in the case of template method when compared to non-template technique. The observed effect is attributed to the synergistic effect of higher surface area of these deposits and catalytic ability of Ni(II)/Ni(III) redox couple.

  3. Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems.

    PubMed

    Bihmidine, Saadia; Julius, Benjamin T; Dweikat, Ismail; Braun, David M

    2016-01-01

    Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed.

  4. Tonoplast Sugar Transporters (SbTSTs) putatively control sucrose accumulation in sweet sorghum stems

    PubMed Central

    Bihmidine, Saadia; Julius, Benjamin T; Dweikat, Ismail; Braun, David M

    2016-01-01

    ABSTRACT Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose accumulation. A model illustrating potential roles for different classes of sugar transport proteins in sorghum sugar partitioning is discussed. PMID:26619184

  5. The Martian ocean: First acid, then alkaline

    NASA Technical Reports Server (NTRS)

    Schaefer, M. W.

    1992-01-01

    In Mars' distant past, carbon dioxide and water may have been plentiful. Values of total outgassed CO2 from several to about 10 bar are consistent with present knowledge, and this amount of CO2 implies an amount of water outgassed equal to an equivalent depth of 500 to 1000 m. It is quite reasonable, therefore, to envision an early Mars in which there was a body or bodies of liquid water, perhaps in the northern plains, and a dense carbon dioxide atmosphere. Under such conditions, the pH of the water will be low, due to the dissolution of carbon dioxide in the water to form carbonic acid. This acidic water is capable of weathering the available rock quite intensely, particularly because this rock is likely to be heavily fractured (from meteorite bombardment) or even consist of fine particles (such as pyroclastic deposits). As time goes on, however, the carbon dioxide atmosphere will rapidly pass through the ocean to form carbonate deposits. As the density of the atmosphere decreases, so will the flux of carbonic acid into the ocean. Without this input of carbonic acid, the effect of the dissolved weathering products will be to increase the pH of the water. The ocean will then become alkaline. To study this process, I have developed a geochemical cycle model for the atmosphere-hydrosphere-regolith system of Mars. The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success. This method is capable of elegantly handling the interactions between the simultaneous chemical reactions needed to understand such a system.

  6. Martian alkaline basites chemically resemble basic rocks of the Lovozero alkaline massif, Kola peninsula

    NASA Astrophysics Data System (ADS)

    Kochemasov, G.

    The comparative wave planetology [1, 5] successfully overcomes the most principal martian test having now analyses of alkaline rocks from Columbia Hills [2, 3, 4]. This kind of rocks was predicted earlier on basis of the wave paradigm having stated that "the higher planetary relief range - the higher density difference between lithologies composing hypsometrically (tectonically) contrasting blocks [5]. This paradigm declares that "celestial bodies are dichotomic"(Theorem 1), "celestial bodies are sectoral" (Theorem 2), "celestial bodies are granular"(Theorem 3), "angular momenta of different level blocks tend to be equal" (Theorem 4)[1, 5]. Mars is a typical terrestrial planet but the farthest from Sun and thus with the smallest tide effects. Nevertheless it has the highest relief range and seems to be most distorted (ellipsoid in shape) and broken by deep fissures. The wave approach explains this by a warping action of standing waves of 4 ortho- and diagonal directions - they are the longest and highest in the martian case. These interfering warping waves caused by the elliptic keplerian orbits implying periodically changing accelerations and inertia-gravity forces produce inevitable tectonic dichotomy (the fundamental wave 1 long 2πR), sectoring (wave 2, πR, and other overtones), granulation. A granule size depends on an orbital frequency: the higher frequency the smaller granule. The Earth's granule, as a scale, is πR/4 (see it in NASA's PIA04159), Venus ` πR/6, Mercury's πR/16, Mars' πR/2 (the sizes are strictly tied to orb. fr.). Along with the granule sizes increase relief ranges ( Mercury ˜5 km, Venus 14, Earth 20, Mars ˜30) and compositional (density) difference between lowland and highland lithologies [5]. The lowland compositions become Fericher and denser: enstatite (Mercury), Mg-basalt (Venus), tholeiite (Earth), Fe-basalt (Mars). The highland compositions get less dense, lighter: anorthosite, alkaline basalt, andesite and conditional "albitite

  7. Hydroxide Self-Feeding High-Temperature Alkaline Direct Formate Fuel Cells.

    PubMed

    Li, Yinshi; Sun, Xianda; Feng, Ying

    2017-03-11

    Conventionally, both the thermal degradation of the anion-exchange membrane and the requirement of additional hydroxide for fuel oxidation reaction hinder the development of the high-temperature alkaline direct liquid fuel cells. The present work addresses these two issues by reporting a polybenzimidazole-membrane-based direct formate fuel cell (DFFC). Theoretically, the cell voltage of the high-temperature alkaline DFFC can be as high as 1.45 V at 90 °C. It has been demonstrated that a proof-of-concept alkaline DFFC without adding additional hydroxide yields a peak power density of 20.9 mW cm(-2) , an order of magnitude higher than both alkaline direct ethanol fuel cells and alkaline direct methanol fuel cells, mainly because the hydrolysis of formate provides enough OH(-) ions for formate oxidation reaction. It was also found that this hydroxide self-feeding high-temperature alkaline DFFC shows a stable 100 min constant-current discharge at 90 °C, proving the conceptual feasibility.

  8. Structure and ionic diffusion of alkaline-earth ions in mixed cation glasses

    SciTech Connect

    Konstantinou, Konstantinos; Sushko, Petr; Duffy, Dorothy M.

    2015-08-15

    A series of mixed cation silicate glasses of the composition A2O – 2MO – 4SiO2, with A=Li,Na,K and M=Ca,Sr,Ba has been investigated by means of molecular dynamics simulations in order to understand the effect of the nature of the cations on the mobility of the alkaline-earth ions within the glass network. The size of the alkaline-earth cation was found to affect the inter-atomic distances, the coordination number distributions and the bond angle distributions , whereas the medium-range order was almost unaffected by the type of the cation. All the alkaline-earth cations contribute to lower vibrational frequencies but it is observed that that there is a shift to smaller frequencies and the vibrational density of states distribution gets narrower as the size of the alkaline-earth increases. The results from our modeling for the ionic diffusion of the alkaline-earth cations are in a qualitative agreement with the experimental observations in that there is a distinct correlation between the activation energy for diffusion of alkaline earth-ions and the cation radii ratio. An asymmetrical linear behavior in the diffusion activation energy with increasing size difference is observed. The results can be described on the basis of a theoretical model that relates the diffusion activation energy to the electrostatic interactions of the cations with the oxygens and the elastic deformation of the silicate network.

  9. Effect of diets containing sucrose vs. D-tagatose in hypercholesterolemic mice.

    PubMed

    Police, Sara B; Harris, J Clay; Lodder, Robert A; Cassis, Lisa A

    2009-02-01

    Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr(-/-)) mice. LDLr(-/-) male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.

  10. Effect of Diets Containing Sucrose vs. D-tagatose in Hypercholesterolemic Mice

    PubMed Central

    Police, Sara B.; Harris, J. Clay; Lodder, Robert A.; Cassis, Lisa A.

    2010-01-01

    Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr−/−) mice. LDLr−/− male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis. PMID:19008872

  11. Effect of Diets Containing Sucrose vs. D-tagatose in Hypercholesterolemic Mice

    SciTech Connect

    Police, S.; Harris, J; Lodder, R; Cassis, L

    2008-01-01

    Effects of functional sweeteners on the development of the metabolic syndrome and atherosclerosis are unknown. The objective was to compare the effect of dietary carbohydrate in the form of sucrose (SUCR) to D-tagatose (TAG; an isomer of fructose currently used as a low-calorie sweetener) on body weight, blood cholesterol concentrations, hyperglycemia, and atherosclerosis in low-density lipoprotein receptor deficient (LDLr-/-) mice. LDLr-/- male and female mice were fed either standard murine diet or a diet enriched with TAG or SUCR as carbohydrate sources for 16 weeks. TAG and SUCR diets contained equivalent amounts (g/kg) of protein, fat, and carbohydrate. We measured food intake, body weight, adipocyte diameter, serum cholesterol and lipoprotein concentrations, and aortic atherosclerosis. Macrophage immunostaining and collagen content were examined in aortic root lesions. CONTROL and TAG-fed mice exhibited similar energy intake, body weights and blood glucose and insulin concentrations, but SUCR-fed mice exhibited increased energy intake and became obese and hyperglycemic. Adipocyte diameter increased in female SUCR-fed mice compared to TAG and CONTROL. Male and female SUCR-fed mice had increased serum cholesterol and triglyceride concentrations compared to TAG and CONTROL. Atherosclerosis was increased in SUCR-fed mice of both genders compared to TAG and CONTROL. Lesions from SUCR-fed mice exhibited pronounced macrophage immunostaining and reductions in collagen content compared to TAG and CONTROL mice. These results demonstrate that in comparison to sucrose, equivalent substitution of TAG as dietary carbohydrate does not result in the same extent of obesity, hyperglycemia, hyperlipidemia, and atherosclerosis.

  12. Alkaline tolerant dextranase from streptomyces anulatus

    DOEpatents

    Decker, Stephen R.; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.

    2003-01-01

    A process for production of an alkaline tolerant dextranase enzyme comprises culturing a dextran-producing microorganism Streptomyces anulatus having accession no. ATCC PTA-3866 to produce an alkaline tolerant dextranase, Dex 1 wherein the protein in said enzyme is characterized by a MW of 63.3 kDa and Dex 2 wherein its protein is characterized by a MW of 81.8 kDa.

  13. Technetium recovery from high alkaline solution

    DOEpatents

    Nash, Charles A.

    2016-07-12

    Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

  14. Toxicity of alkalinity to Hyalella azteca

    USGS Publications Warehouse

    Lasier, P.J.; Winger, P.V.; Reinert, R.E.

    1997-01-01

    Toxicity testing and chemical analyses of sediment pore water have been suggested for use in sediment quality assessments and sediment toxicity identification evaluations. However, caution should be exercised in interpreting pore-water chemistry and toxicity due to inherent chemical characteristics and confounding relationships. High concentrations of alkalinity, which are typical of sediment pore waters from many regions, have been shown to be toxic to test animals. A series of tests were conducted to assess the significance of elevated alkalinity concentrations to Hyalella azteca, an amphipod commonly used for sediment and pore-water toxicity testing. Toxicity tests with 14-d old and 7-d old animals were conducted in serial dilutions of sodium bicarbonate (NaHCO3) solutions producing alkalinities ranging between 250 to 2000 mg/L as CaCO3. A sodium chloride (NaCl) toxicity test was also conducted to verify that toxicity was due to bicarbonate and not sodium. Alkalinity was toxic at concentrations frequently encountered in sediment pore water. There was also a significant difference in the toxicity of alkalinity between 14-d old and 7-d old animals. The average 96-h LC50 for alkalinity was 1212 mg/L (as CaCO3) for 14-d old animals and 662 mg/L for the younger animals. Sodium was not toxic at levels present in the NaHCO3 toxicity tests. Alkalinity should be routinely measured in pore-water toxicity tests, and interpretation of toxicity should consider alkalinity concentration and test-organism tolerance.

  15. Sucrose Transporter ZmSut1 Expression and Localization Uncover New Insights into Sucrose Phloem Loading1[OPEN

    PubMed Central

    Baker, R. Frank; Leach, Kristen A.; Boyer, Nathanial R.; Skopelitis, Tara; Jackson, David; Braun, David M.

    2016-01-01

    Sucrose transporters (SUTs) translocate sucrose (Suc) across cellular membranes, and in eudicots, multiple SUTs are known to function in Suc phloem loading in leaves. In maize (Zea mays), the Sucrose Transporter1 (ZmSut1) gene has been implicated in Suc phloem loading based upon RNA expression in leaves, electrophysiological experiments, and phenotypic analysis of zmsut1 mutant plants. However, no previous studies have examined the cellular expression of ZmSut1 RNA or the subcellular localization of the ZmSUT1 protein to assess the gene’s hypothesized function in Suc phloem loading or to evaluate its potential roles, such as phloem unloading, in nonphotosynthetic tissues. To this end, we performed RNA in situ hybridization experiments, promoter-reporter gene analyses, and ZmSUT1 localization studies to elucidate the cellular expression pattern of the ZmSut1 transcript and protein. These data showed that ZmSut1 was expressed in multiple cell types throughout the plant and indicated that it functions in phloem companion cells to load Suc and also in other cell types to retrieve Suc from the apoplasm to prevent its accumulation and loss to the transpiration stream. Additionally, by comparing a phloem-mobile tracer with ZmSut1 expression, we determined that developing maize leaves dynamically switch from symplasmic to apoplasmic phloem unloading, reconciling previously conflicting reports, and suggest that ZmSut1 does not have an apparent function in either unloading process. A model for the dual roles for ZmSut1 function (phloem loading and apoplasmic recycling), Sut1 evolution, and its possible use to enhance Suc export from leaves in engineering C3 grasses for C4 photosynthesis is discussed. PMID:27621426

  16. Alkaline Water and Longevity: A Murine Study

    PubMed Central

    Magro, Massimiliano; Corain, Livio; Ferro, Silvia; Baratella, Davide; Bonaiuto, Emanuela; Terzo, Milo; Corraducci, Vittorino; Salmaso, Luigi; Vianello, Fabio

    2016-01-01

    The biological effect of alkaline water consumption is object of controversy. The present paper presents a 3-year survival study on a population of 150 mice, and the data were analyzed with accelerated failure time (AFT) model. Starting from the second year of life, nonparametric survival plots suggest that mice watered with alkaline water showed a better survival than control mice. Interestingly, statistical analysis revealed that alkaline water provides higher longevity in terms of “deceleration aging factor” as it increases the survival functions when compared with control group; namely, animals belonging to the population treated with alkaline water resulted in a longer lifespan. Histological examination of mice kidneys, intestine, heart, liver, and brain revealed that no significant differences emerged among the three groups indicating that no specific pathology resulted correlated with the consumption of alkaline water. These results provide an informative and quantitative summary of survival data as a function of watering with alkaline water of long-lived mouse models. PMID:27340414

  17. Performed surfactant-optimized aqueous alkaline flood

    SciTech Connect

    Thigpen, D.R.; Lawson, J.B.; Nelson, R.C.

    1991-11-26

    This paper describes improvement in a process for recovering oil from an acidic oil reservoir by injecting an aqueous alkaline solution comprising water, sodium chloride, and alkaline material for reacting with the reservoir oil forming a petroleum acid soap to form an in-situ surfactant system. The improvement comprises: selecting a preformed cosurfactant which is soluble in both the aqueous solution and the reservoir oil and has a solubility ratio which is grater than the solubility ratio of the petroleum acid soap where the solubility ratio is the ratio of solubility in the aqueous alkaline solution to the solubility in the reservoir oil; combining with the alkaline solution an amount of the preformed cosurfactant which will result in the in-situ surfacant system having a salinity about equal to a salinity which results in minimal interfacial tension between the oil in the reservoir and the in-situ surfactant system at reservoir temperature, wherein the amount of the preformed cosurfactant is about 0.3 percent by weight in the aqueous alkaline solution; and injecting the cosurfactant-aqueous alkaline solution mixture into the reservoir to displace oil toward a fluid production location.

  18. Specificity in lipases: A computational study of transesterification of sucrose

    PubMed Central

    Fuentes, Gloria; Ballesteros, Anthonio; Verma, Chandra S.

    2004-01-01

    Computational conformational searches of putative transition states of the reaction of sucrose with vinyl laurate catalyzed by lipases from Candida antarctica B and Thermomyces lanuginosus have been carried out. The dielectric of the media have been varied to understand the role of protein plasticity in modulating the observed regioselective transesterification. The binding pocket of lipase from Candida adapts to the conformational variability of the various substates of the substrates by small, local adjustments within the binding pocket. In contrast, the more constrained pocket of the lipase from Thermomyces adapts by adjusting through concerted global motions between subdomains. This leads to the identification of one large pocket in Candida that accommodates both the sucrose and the lauroyl moieties of the transition state, whereas in Thermomyces the binding pocket is smaller, leading to the localization of the two moieties in two distinct pockets; this partly rationalizes the broader specificity of the former relative to the latter. Mutations have been suggested to exploit the differences towards changing the observed selectivities. PMID:15557256

  19. Prospects for increasing starch and sucrose yields for bioethanol production.

    PubMed

    Smith, Alison M

    2008-05-01

    In the short term, the production of bioethanol as a liquid transport fuel is almost entirely dependent on starch and sugars from existing food crops. The sustainability of this industry would be enhanced by increases in the yield of starch/sugar per hectare without further inputs into the crops concerned. Efforts to achieve increased yields of starch over the last three decades, in particular via manipulation of the enzyme ADPglucose pyrophosphorylase, have met with limited success. Other approaches have included manipulation of carbon partitioning within storage organs in favour of starch synthesis, and attempts to manipulate source-sink relationships. Some of the most promising results so far have come from manipulations that increase the availability of ATP for starch synthesis. Future options for achieving increased starch contents could include manipulation of starch degradation in organs in which starch turnover is occurring, and introduction of starch synthesis into the cytosol. Sucrose accumulation is much less well understood than starch synthesis, but recent results from research on sugar cane suggest that total sugar content can be greatly increased by conversion of sucrose into a non-metabolizable isomer. A better understanding of carbohydrate storage and turnover in relation to carbon assimilation and plant growth is required, both for improvement of starch and sugar crops and for attempts to increase biomass production in second-generation biofuel crops.

  20. Biosynthesis of sucrose and mannitol as a function of leaf age in celery (Apium graveolens L. )

    SciTech Connect

    Davis, J.M.; Fellman, J.K.; Loescher, W.H.

    1988-01-01

    In celery (Apium graveolens L.), the two major translocated carbohydrates are sucrose and the acyclic polyol mannitol. Their metabolism, however, is different and their specific functions are uncertain. To compare their roles in carbon partitioning and sink-source transitions, developmental changes in /sup 14/CO/sub 2/ labeling, pool sizes, and key enzyme activities in leaf tissues were examined. The proportion of label in mannitol increased dramatically with leaf maturation whereas that in sucrose remained fairly constant. Mannitol content, however, was high in all leaves and sucrose content increased as leaves developed. Activities of mannose-6-P reductase, cytoplasmic and chloroplastic fructose-1,6-bis-phosphatases, sucrose phosphate synthase, and sucrose synthase increased with leaf maturation and decreased as leaves senesced. Ribulose bisphosphate carboxylase and nonreversible glyceraldehyde-3-P dehydrogenase activities rose as leaves developed but did not decrease. Thus, sucrose is produced in all photosynthetically active leaves whereas mannitol is synthesized primarily in mature leaves and stored in all leaves. Onset of sucrose export in celery may result from sucrose accumulation in expanding leaves, but mannitol export is clearly unrelated to mannitol concentration. Mannitol export, however, appears to coincide with increased mannitol biosynthesis. Although mannitol and sucrose arise from a common precursor in celery, subsequent metabolism and transport must be regulated separately.

  1. Sucrose in bloom-forming cyanobacteria: loss and gain of genes involved in its biosynthesis.

    PubMed

    Kolman, María A; Salerno, Graciela L

    2016-02-01

    Bloom-forming cyanobacteria are widely distributed in freshwater ecosystems. To cope with salinity fluctuations, cyanobacteria synthesize compatible solutes, such as sucrose, to maintain the intracellular osmotic balance. The screening of cyanobacterial genomes revealed that homologues to sucrose metabolism-related genes only occur in few bloom-forming strains, mostly belonging to Nostocales and Stigonematales orders. Remarkably, among Chroococcales and Oscillatoriales strains, homologues were only found in M. aeruginosa PCC 7806 and Leptolyngbya boryana PCC 6306, suggesting a massive loss of sucrose metabolism in bloom-forming strains of these orders. After a complete functional characterization of sucrose genes in M. aeruginosa PCC 7806, we showed that sucrose metabolism depends on the expression of a gene cluster that defines a transcriptional unit, unique among all sucrose-containing cyanobacteria. It was also demonstrated that the expression of the encoding genes of sucrose-related proteins is stimulated by salt. In view of its ancestral origin in cyanobacteria, the fact that most bloom-forming strains lack sucrose metabolism indicates that the genes involved might have been lost during evolution. However, in a particular strain, like M. aeruginosa PCC 7806, sucrose synthesis genes were probably regained by horizontal gene transfer, which could be hypothesized as a response to salinity fluctuations.

  2. Differential regulation of two sucrose transporters by defoliation and light conditions in perennial ryegrass.

    PubMed

    Furet, Pierre-Maxime; Berthier, Alexandre; Decau, Marie-Laure; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; Noiraud-Romy, Nathalie; Meuriot, Frédéric

    2012-12-01

    Sucrose transport between source and sink tissues is supposed to be a key-step for an efficient regrowth of perennial rye-grass after defoliation and might be altered by light conditions. We assessed the effect of different light regimes (high vs low light applied before or after defoliation) on growth, fructans and sucrose mobilization, as well as on sucrose transporter expression during 14 days of regrowth. Our results reported that defoliation led to a mobilization of C reserves (first sucrose and then fructans), which was parallel to an induction of LpSUT1 sucrose transporter expression in source and sink tissues (i.e. leaf sheaths and elongating leaf bases, respectively) irrespective to light conditions. Light regime (high or low light) had little effects on regrowth and on C reserves mobilization during the first 48 h of regrowth after defoliation. Thereafter, low light conditions, delaying the recovery of photosynthetic capacities, had a negative effect on C reserves re-accumulation (especially sucrose). Surprisingly, high light did not enhance sucrose transporter expression. Indeed, while light conditions had no effect on LpSUT1 expression, LpSUT2 transcripts levels were enhanced for low light grown plants. These results indicate that two sucrose transporter currently identified in Lolium perenne L. are differentially regulated by light and sucrose.

  3. Combined compared to dissociated oral and intestinal sucrose stimuli induce different brain hedonic processes

    PubMed Central

    Clouard, Caroline; Meunier-Salaün, Marie-Christine; Meurice, Paul; Malbert, Charles-Henri; Val-Laillet, David

    2014-01-01

    The characterization of brain networks contributing to the processing of oral and/or intestinal sugar signals in a relevant animal model might help to understand the neural mechanisms related to the control of food intake in humans and suggest potential causes for impaired eating behaviors. This study aimed at comparing the brain responses triggered by oral and/or intestinal sucrose sensing in pigs. Seven animals underwent brain single photon emission computed tomography (99mTc-HMPAO) further to oral stimulation with neutral or sucrose artificial saliva paired with saline or sucrose infusion in the duodenum, the proximal part of the intestine. Oral and/or duodenal sucrose sensing induced differential cerebral blood flow changes in brain regions known to be involved in memory, reward processes and hedonic (i.e., pleasure) evaluation of sensory stimuli, including the dorsal striatum, prefrontal cortex, cingulate cortex, insular cortex, hippocampus, and parahippocampal cortex. Sucrose duodenal infusion only and combined sucrose stimulation induced similar activity patterns in the putamen, ventral anterior cingulate cortex and hippocampus. Some brain deactivations in the prefrontal and insular cortices were only detected in the presence of oral sucrose stimulation. Finally, activation of the right insular cortex was only induced by combined oral and duodenal sucrose stimulation, while specific activity patterns were detected in the hippocampus and parahippocampal cortex with oral sucrose dissociated from caloric load. This study sheds new light on the brain hedonic responses to sugar and has potential implications to unravel the neuropsychological mechanisms underlying food pleasure and motivation. PMID:25147536

  4. Sucrose produces withdrawal and dopamine-sensitive reinforcing effects in planarians.

    PubMed

    Zhang, Charlie; Tallarida, Christopher S; Raffa, Robert B; Rawls, Scott M

    2013-03-15

    Sucrose produces physical dependence and reinforcing effects in rats. We hypothesized that similar effects could be demonstrated in planarians, the earliest animal with a centralized nervous system. We used two assays, one that quantifies withdrawal responses during drug absence as a reduction in motility and another that quantifies reinforcing effects using a conditioned place preference (CPP) design. In withdrawal experiments, planarians exposed to sucrose (1%) for 60 min and then tested in water for 5 min displayed reduced motility compared to water controls. Acute or continuous sucrose (1%) exposure did not affect motility. CPP experiments used a biased design to capitalize upon planarians' natural preference for the dark (pretest, sucrose conditioning in the light, posttest). Planarians conditioned with sucrose (1%) displayed a greater preference shift than sucrose-naïve planarians. Glucose (0.1, 1%), but not the non-digestible disaccharide lactulose (0.1, 1%), also produced a greater preference shift than water-exposed planarians. Development of sucrose-induced CPP was inhibited when sucrose (1%) conditioning was conducted in combination with dopamine receptor antagonists SCH 23390 (1 μM) or sulpiride (1 μM). These results suggest that the rewarding and reinforcing effects of sugar are highly conserved across species and that planarians offer an invertebrate model to provide insight into the pharmacological effects of sucrose and related sweeteners.

  5. Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose.

    PubMed

    Yadav, Rajeev; Sen, Pratik

    2013-11-01

    This study is devoted to understand the unfolding mechanism of a multidomain protein, human serum albumin (HSA), in absence and presence of the sucrose by steady-state and time-resolved fluorescence spectroscopy with domain specific marker molecules and is further being substantiated by molecular dynamics (MD) simulation. In water, the domain III of HSA found to unfold first followed by domains I and II as the concentration of GnHCl is increased in the medium. The sequential unfolding behavior of different domains of HSA remains same in presence of sucrose; however, a higher GnHCl concentration is required for unfolding, suggesting stabilizing effect of sucrose on HSA. Domain I is found to be most stabilized by sucrose. The stabilization of domain II is somewhat similar to domain I, but the effect of sucrose on domain III is found to be very small. MD simulation also predicted a similar behavior of sucrose on HSA. The stabilizing effect of sucrose is explained in terms of the entrapment of water molecules in between HSA surface and sucrose layer as well as direct interaction between HSA and sucrose.

  6. Sucrose delays senescence and preserves functional compounds in Asparagus officinalis L.

    PubMed

    Park, Me-Hea

    2016-11-11

    The high metabolic rate of harvested asparagus spears (Asparagus officinalis L.) causes rapid deterioration. To extend shelf life, we investigated the effect of sucrose treatment on asparagus during storage. Asparagus spears were treated with 3%, 5%, and 10% sucrose and stored at 2 °C for 20 h. Cellular respiration decreased, but other processes were unaltered by exogenous sucrose. The overall appearance of asparagus treated with 3% sucrose and stored at 2 °C for 18 days was rated as good and excellent, unlike that of untreated spears. Asparagus treated with sucrose maintained firmness for 15 days, while untreated spears lost firmness and showed increased water-soluble pectin content during storage. Carbohydrate levels were also higher in sucrose-treated than in control samples. Transcript levels of cell-wall-related genes, including xyloglucan endotransglycosylase (XET)1, XET2, and peroxidase (prx)1, prx2, and prx3 were upregulated by sucrose. Cyanidin 3-O-rutinoside and rutin levels immediately increased upon addition of sucrose and remained high relative to the control during storage. Thus, sucrose modulates asparagus cell wall components and maintains the functionality of important compounds during storage, thus effectively prolonging shelf life.

  7. Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose

    PubMed Central

    Yadav, Rajeev; Sen, Pratik

    2013-01-01

    This study is devoted to understand the unfolding mechanism of a multidomain protein, human serum albumin (HSA), in absence and presence of the sucrose by steady-state and time-resolved fluorescence spectroscopy with domain specific marker molecules and is further being substantiated by molecular dynamics (MD) simulation. In water, the domain III of HSA found to unfold first followed by domains I and II as the concentration of GnHCl is increased in the medium. The sequential unfolding behavior of different domains of HSA remains same in presence of sucrose; however, a higher GnHCl concentration is required for unfolding, suggesting stabilizing effect of sucrose on HSA. Domain I is found to be most stabilized by sucrose. The stabilization of domain II is somewhat similar to domain I, but the effect of sucrose on domain III is found to be very small. MD simulation also predicted a similar behavior of sucrose on HSA. The stabilizing effect of sucrose is explained in terms of the entrapment of water molecules in between HSA surface and sucrose layer as well as direct interaction between HSA and sucrose. PMID:24038622

  8. Exposure to sucrose during periods of withdrawal does not reduce cocaine-seeking behavior in rats

    PubMed Central

    Nicolas, Céline; Lafay-Chebassier, Claire; Solinas, Marcello

    2016-01-01

    Concomitant access to drugs of abuse and alternative rewards such as sucrose has been shown to decrease addiction-related behaviors in animals. Here we investigated whether access to sucrose during abstinence in contexts that are temporally and physically distinct from drug-related contexts could reduce subsequent drug seeking. In addition, we investigated whether a history of cocaine self-administration would alter the rewarding effects of sucrose. Rats self-administered cocaine for ten sessions, while yoked-saline rats received only saline injections, and then we subjected them to a 30-day withdrawal period during which they had access to water and sucrose continuously or intermittently according to a schedule that induces binge-drinking behavior. At the end of the withdrawal period, rats were tested for cocaine seeking behavior during a single 6 h session. We found that exposure to cocaine increased sucrose consumption only when rats had intermittent access to sucrose, but exposure to sucrose did not alter drug seeking regardless of the schedule of access. These results suggest that exposure to cocaine cross-sensitizes to the rewarding effects of sucrose, but exposure to sucrose during abstinence, temporally and physically distinct from drug-related environments, does not to reduce drug seeking. PMID:26997496

  9. Exposure to sucrose during periods of withdrawal does not reduce cocaine-seeking behavior in rats.

    PubMed

    Nicolas, Céline; Lafay-Chebassier, Claire; Solinas, Marcello

    2016-03-21

    Concomitant access to drugs of abuse and alternative rewards such as sucrose has been shown to decrease addiction-related behaviors in animals. Here we investigated whether access to sucrose during abstinence in contexts that are temporally and physically distinct from drug-related contexts could reduce subsequent drug seeking. In addition, we investigated whether a history of cocaine self-administration would alter the rewarding effects of sucrose. Rats self-administered cocaine for ten sessions, while yoked-saline rats received only saline injections, and then we subjected them to a 30-day withdrawal period during which they had access to water and sucrose continuously or intermittently according to a schedule that induces binge-drinking behavior. At the end of the withdrawal period, rats were tested for cocaine seeking behavior during a single 6 h session. We found that exposure to cocaine increased sucrose consumption only when rats had intermittent access to sucrose, but exposure to sucrose did not alter drug seeking regardless of the schedule of access. These results suggest that exposure to cocaine cross-sensitizes to the rewarding effects of sucrose, but exposure to sucrose during abstinence, temporally and physically distinct from drug-related environments, does not to reduce drug seeking.

  10. Body weight manipulation, reinforcement value and choice between sucrose and wheel running: a behavioral economic analysis.

    PubMed

    Belke, Terry W; Pierce, W David

    2009-02-01

    Twelve female Long-Evans rats were exposed to concurrent variable (VR) ratio schedules of sucrose and wheel-running reinforcement (Sucrose VR 10 Wheel VR 10; Sucrose VR 5 Wheel VR 20; Sucrose VR 20 Wheel VR 5) with predetermined budgets (number of responses). The allocation of lever pressing to the sucrose and wheel-running alternatives was assessed at high and low body weights. Results showed that wheel-running rate and lever-pressing rates for sucrose and wheel running increased, but the choice of wheel running decreased at the low body weight. A regression analysis of relative consumption as a function of relative price showed that consumption shifted toward sucrose and interacted with price differences in a manner consistent with increased substitutability. Demand curves showed that demand for sucrose became less elastic while demand for wheel running became more elastic at the low body weight. These findings reflect an increase in the difference in relative value of sucrose and wheel running as body weight decreased. Discussion focuses on the limitations of response rates as measures of reinforcement value. In addition, we address the commonalities between matching and demand curve equations for the analysis of changes in relative reinforcement value.

  11. Mechanism and models for zinc metal morphology in alkaline media

    NASA Technical Reports Server (NTRS)

    May, C. E.; Kautz, H. E.

    1981-01-01

    Based on experimental observations, a mechanism is presented to explain existence of the different morphologies of electrodeposited zinc in alkaline solution. The high current density dendrites appear to be due to more rapid growth on the nonbasal crystallographic planes than on the basal plane. The low current density moss apparently results from dissolution from the nonbasal planes at low cathodic voltages. Electrochemical models were sought which would produce such a phenomenon. The fundamental plating mechanism alone accounts only for different rates on different planes, not for zinc dissolution from a plane in the cathodic region. Fourteen models were explored; two models were in accord with the proposed mechanism. One involves rapid disproportionation of the zinc +1 species on the nonbasal planes. The other involves a redox reaction (corrosion) between the zinc-zincate and hydrogen-water systems.

  12. [Alkaline phosphatase in Amoeba proteus].

    PubMed

    Sopina, V A

    2005-01-01

    In free-living Amoeba proteus (strain B), 3 phosphatase were found after disc-electrophoresis of 10 microg of protein in PAGE and using 1-naphthyl phosphate as a substrate a pH 9.0. These phosphatases differed in their electrophoretic mobilities - "slow" (1-3 bands), "middle" (one band) and "fast" (one band). In addition to 1-naphthyl phosphate, "slow" phosphatases were able to hydrolyse 2-naphthyl phosphate and p-nitrophenyl phosphate. They were slightly activated by Mg2+, completely inhibited by 3 chelators (EDTA, EGTA and 1,10-phenanthroline), L-cysteine, sodium dodecyl sulfate and Fe2+, Zn2+ and Mn2+ (50 mM), considerably inactivated by orthovanadate, molybdate, phosphatase inhibitor cocktail 1, p-nitrophenyl phosphate, Na2HPO4, DL-dithiothreitol and urea and partly inhibited by H2O2, DL-phenylalanine, 2-mercaptoethanol, phosphatase inhibitor cocktail 2 and Ca2+. Imidazole, L-(+)-tartrate, okadaic acid, NaF and sulfhydryl reagents -p-(hydroxy-mercuri)benzoate and N-ethylmaleimide - had no influence on the activity of "slow" phosphatases. "Middle" and "fast" phosphatases, in contrast to "slow" ones, were not inactivated by 3 chelators. The "middle" phosphatase differed from the "fast" one by smaller resistance to urea, Ca2+, Mn2+, phosphates and H2O2 and greater resistance to dithiothreitol and L-(+)-tartrate. In addition, the "fast" phosphatase was inhibited by L-cysteine but the "middle" one was activated by it. Of 5 tested ions (Mg2+, Cu2+, Mn2+, Ca2+ and Zn2+), only Zn2+ reactivated "slow" phosphatases after their inactivation by EDTA treatment. The reactivation of apoenzyme was only partial (about 35 %). Thus, among phosphatases found in amoebae at pH 9.0, only "slow" ones are Zn-metalloenzymes and may be considered as alkaline phosphatases (EC 3.1.3.1). It still remains uncertain, to which particular phosphatase class "middle" and "fast" phosphatases (pH 9.0) may belong.

  13. A Novel Wistar Rat Model of Obesity-Related Nonalcoholic Fatty Liver Disease Induced by Sucrose-Rich Diet.

    PubMed

    Lima, Maria Luíza R P; Leite, Laura H R; Gioda, Carolina R; Leme, Fabíola O P; Couto, Claudia A; Coimbra, Cândido C; Leite, Virginia H R; Ferrari, Teresa Cristina A

    2016-01-01

    The pathogenesis of nonalcoholic fatty liver disease (NAFLD) is not fully understood, and experimental models are an alternative to study this issue. We investigated the effects of a simple carbohydrate-rich diet on the development of obesity-related NAFLD and the impact of physical training on the metabolic abnormalities associated with this disorder. Sixty Wistar rats were randomly separated into experimental and control groups, which were fed with sucrose-enriched (18% simple carbohydrates) and standard diet, respectively. At the end of each experimental period (5, 10, 20, and 30 weeks), 6 animals from each group were sacrificed for blood tests and liver histology and immunohistochemistry. From weeks 25 to 30, 6 animals from each group underwent physical training. The experimental group animals developed obesity and NAFLD, characterized histopathologically by steatosis and hepatocellular ballooning, clinically by increased thoracic circumference and body mass index associated with hyperleptinemia, and metabolically by hyperglycemia, hyperinsulinemia, hypertriglyceridemia, increased levels of very low-density lipoprotein- (VLDL-) cholesterol, depletion of the antioxidants liver enzymes superoxide dismutase and catalase, and increased hepatic levels of malondialdehyde, an oxidative stress marker. Rats that underwent physical training showed increased high-density lipoprotein- (HDL-) cholesterol levels. In conclusion, a sucrose-rich diet induced obesity, insulin resistance, oxidative stress, and NAFLD in rats.

  14. A Novel Wistar Rat Model of Obesity-Related Nonalcoholic Fatty Liver Disease Induced by Sucrose-Rich Diet

    PubMed Central

    Lima, Maria Luíza R. P.; Leite, Laura H. R.; Gioda, Carolina R.; Leme, Fabíola O. P.; Couto, Claudia A.; Coimbra, Cândido C.; Leite, Virginia H. R.; Ferrari, Teresa Cristina A.

    2016-01-01

    The pathogenesis of nonalcoholic fatty liver disease (NAFLD) is not fully understood, and experimental models are an alternative to study this issue. We investigated the effects of a simple carbohydrate-rich diet on the development of obesity-related NAFLD and the impact of physical training on the metabolic abnormalities associated with this disorder. Sixty Wistar rats were randomly separated into experimental and control groups, which were fed with sucrose-enriched (18% simple carbohydrates) and standard diet, respectively. At the end of each experimental period (5, 10, 20, and 30 weeks), 6 animals from each group were sacrificed for blood tests and liver histology and immunohistochemistry. From weeks 25 to 30, 6 animals from each group underwent physical training. The experimental group animals developed obesity and NAFLD, characterized histopathologically by steatosis and hepatocellular ballooning, clinically by increased thoracic circumference and body mass index associated with hyperleptinemia, and metabolically by hyperglycemia, hyperinsulinemia, hypertriglyceridemia, increased levels of very low-density lipoprotein- (VLDL-) cholesterol, depletion of the antioxidants liver enzymes superoxide dismutase and catalase, and increased hepatic levels of malondialdehyde, an oxidative stress marker. Rats that underwent physical training showed increased high-density lipoprotein- (HDL-) cholesterol levels. In conclusion, a sucrose-rich diet induced obesity, insulin resistance, oxidative stress, and NAFLD in rats. PMID:26788524

  15. Correlating the hydrogen evolution reaction activity in alkaline electrolytes with the hydrogen binding energy on monometallic surfaces

    SciTech Connect

    Sheng, WC; Myint, M; Chen, JGG; Yan, YS

    2013-05-01

    The slow reaction kinetics of the hydrogen evolution and oxidation reactions (HER/HOR) on platinum in alkaline electrolytes hinders the development of alkaline electrolysers, solar hydrogen cells and alkaline fuel cells. A fundamental understanding of the exchange current density of the HER/HOR in alkaline media is critical for the search and design of highly active electrocatalysts. By studying the HER on a series of monometallic surfaces, we demonstrate that the HER exchange current density in alkaline solutions can be correlated with the calculated hydrogen binding energy (HBE) on the metal surfaces via a volcano type of relationship. The HER activity varies by several orders of magnitude from Pt at the peak of the plot to W and Au located on the bottom of each side of the plot, similar to the observation in acids. Such a correlation suggests that the HBE can be used as a descriptor for identifying electrocatalysts for HER/HOR in alkaline media, and that the HER exchange current density can be tuned by modifying the surface chemical properties.

  16. HPA axis dampening by limited sucrose intake: reward frequency vs. caloric consumption.

    PubMed

    Ulrich-Lai, Yvonne M; Ostrander, Michelle M; Herman, James P

    2011-04-18

    Individuals often cope with stress by consuming calorically-dense, highly-palatable 'comfort' foods. The present work explores the stress-relieving properties of palatable foods in a rat model of limited sucrose intake. In this model, adult male rats with free access to chow and water are given additional access to a small amount of sucrose drink (or water as a control). A history of such limited sucrose intake reduces the collective (HPA axis, sympathetic, and behavioral-anxiety) stress response. Moreover, the stress-dampening by sucrose appears to be mediated primarily by its rewarding properties, since beneficial effects are reproduced by the noncaloric sweetener saccharin but not oral intragastric gavage of sucrose. The present work uses an alternate strategy to address the hypothesis that the rewarding properties of sucrose mediate its stress-dampening. This work varies the duration, frequency, and/or volume of sucrose and assesses the ability to attenuate HPA axis stress responses. The data indicate that HPA-dampening is optimal with a greater duration and/or frequency of sucrose, whereas increasing the volume of sucrose consumed is without effect. This finding suggests that the primary factor mediating stress-dampening is the number/rate of reward (i.e., sucrose) exposures, rather than the total sucrose calories consumed. Collectively, these data support the hypothesis that stress relief by limited palatable food intake is mediated primarily by its hedonic/rewarding properties. Moreover, the results support the contention that naturally rewarding behaviors are a physiological means to produce stress relief.

  17. Fructose and Sucrose Intake Increase Exogenous Carbohydrate Oxidation during Exercise

    PubMed Central

    Trommelen, Jorn; Fuchs, Cas J.; Beelen, Milou; Lenaerts, Kaatje; Jeukendrup, Asker E.; Cermak, Naomi M.; van Loon, Luc J. C.

    2017-01-01

    Peak exogenous carbohydrate oxidation rates typically reach ~1 g·min−1 during exercise when ample glucose or glucose polymers are ingested. Fructose co-ingestion has been shown to further increase exogenous carbohydrate oxidation rates. The purpose of this study was to assess the impact of fructose co-ingestion provided either as a monosaccharide or as part of the disaccharide sucrose on exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. Ten trained male cyclists (VO2peak: 65 ± 2 mL·kg−1·min−1) cycled on four different occasions for 180 min at 50% Wmax during which they consumed a carbohydrate solution providing 1.8 g·min−1 of glucose (GLU), 1.2 g·min−1 glucose + 0.6 g·min−1 fructose (GLU + FRU), 0.6 g·min−1 glucose + 1.2 g·min−1 sucrose (GLU + SUC), or water (WAT). Peak exogenous carbohydrate oxidation rates did not differ between GLU + FRU and GLU + SUC (1.40 ± 0.06 vs. 1.29 ± 0.07 g·min−1, respectively, p = 0.999), but were 46% ± 8% higher when compared to GLU (0.96 ± 0.06 g·min−1: p < 0.05). In line, exogenous carbohydrate oxidation rates during the latter 120 min of exercise were 46% ± 8% higher in GLU + FRU or GLU + SUC compared with GLU (1.19 ± 0.12, 1.13 ± 0.21, and 0.82 ± 0.16 g·min−1, respectively, p < 0.05). We conclude that fructose co-ingestion (0.6 g·min−1) with glucose (1.2 g·min−1) provided either as a monosaccharide or as sucrose strongly increases exogenous carbohydrate oxidation rates during prolonged exercise in trained cyclists. PMID:28230742

  18. Alkaline Phosphatase Assay for Freshwater Sediments: Application to Perturbed Sediment Systems

    PubMed Central

    Sayler, Gary S.; Puziss, Marla; Silver, Martin

    1979-01-01

    The p-nitrophenyl phosphate hydrolysis-phosphatase assay was modified for use in freshwater sediment. Laboratory studies indicated that the recovery of purified alkaline phosphatase activity was 100% efficient in sterile freshwater sediments when optimized incubation and sonication conditions were used. Field studies of diverse freshwater sediments demonstrated the potential use of this assay for determining stream perturbation. Significant correlations between phosphatase and total viable cell counts, as well as adenosine triphosphate biomass, suggested that alkaline phosphatase activity has utility as an indicator of microbial population density and biomass in freshwater sediments. PMID:16345464

  19. Suckling- and sucrose-induced analgesia in human newborns.

    PubMed

    Blass, E M; Watt, L B

    1999-12-01

    This experiment had three goals: 1. To identify the basis of sucking-induced analgesia in healthy, term, newborn humans undergoing the painful, routine, procedure of heel lance and blood collection. 2. To evaluate how taste-induced and sucking-induced analgesias combine to combat pain. 3. To determine whether facial grimacing was an accurate index of diminished pain, or whether it was linked to tissue trauma. We report that: 1. Sucking an unflavored pacifier was analgesic when and only when suck rate exceeded 30 sucks/min. 2. The combination of sucrose and nonnutritive sucking was remarkably analgesic; we saw no behavioral indication in nine of the ten infants that the heel lance had even occurred. 3. Grimacing was reduced to almost naught by procedures that essentially eliminated crying and markedly reduced heart rate during the blood harvesting procedure.

  20. Identification of sucrose synthase as an actin-binding protein

    NASA Technical Reports Server (NTRS)

    Winter, H.; Huber, J. L.; Huber, S. C.; Davies, E. (Principal Investigator)

    1998-01-01

    Several lines of evidence indicate that sucrose synthase (SuSy) binds both G- and F-actin: (i) presence of SuSy in the Triton X-100-insoluble fraction of microsomal membranes (i.e. crude cytoskeleton fraction); (ii) co-immunoprecipitation of actin with anti-SuSy monoclonal antibodies; (iii) association of SuSy with in situ phalloidin-stabilized F-actin filaments; and (iv) direct binding to F-actin, polymerized in vitro. Aldolase, well known to interact with F-actin, interfered with binding of SuSy, suggesting that a common or overlapping binding site may be involved. We postulate that some of the soluble SuSy in the cytosol may be associated with the actin cytoskeleton in vivo.

  1. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices....

  2. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices....

  3. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices....

  4. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices....

  5. 40 CFR 180.1222 - Sucrose octanoate esters; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Sucrose octanoate esters; exemption... FOOD Exemptions From Tolerances § 180.1222 Sucrose octanoate esters; exemption from the requirement of... octanoate esters in or on all food commodities when used in accordance with good agricultural practices....

  6. Evidence for the presence of a sucrose carrier in immature sugar-beet roots

    SciTech Connect

    Lemoine, R.; Daie, J.; Wyse, R.

    1987-04-01

    Unlike in mature sugar-beet roots, sucrose is assumed to be hydrolyzed by a wall-bound invertase prior to uptake by immature roots. To test this hypothesis, they used a sucrose analog, 1'fluorosucrose which is recognized by the carrier but is a poor substrate for invertases. Asymmetrically labeled sucrose (/sup 3/H-fructose) 1'fluorosucrose (/sup 14/C-glucose) were applied at 10 mM (/sup 3/H//sup 14/C=1) to an attached source leaf. After 6 h, sugars from plant parts in the translocation path were separated on HPLC. /sup 14/C-1'fluorosucrose was translocated and accumulated in the root at a higher rate than /sup 3/H-sucrose due to greater metabolism of /sup 3/H-sucrose in the shoot (indicated by the presence of /sup 3/H in hexose fractions and loss of asymmetry). In the root 25% of the /sup 3/H-sucrose was hydrolyzed to hexoses whereas no /sup 14/C was detected in hexose fractions. The data indicate that despite high cell-wall invertase and cytoplasmic sucrose synthase activities, young sugar-beet roots import and store sucrose without hydrolysis. Therefore, the function of a group translocator at the tonoplast is unclear.

  7. Water–solid interactions in amorphous maltodextrin-crystalline sucrose binary mixtures

    PubMed Central

    Ghorab, Mohamed K.; Toth, Scott J.; Simpson, Garth J.; Mauer, Lisa J.; Taylor, Lynne S.

    2016-01-01

    Amorphous and crystalline solids are commonly found together in a variety of pharmaceutical and food products. In this study, the influence of co-formulation of amorphous maltodextrins (MDs) and crystalline sucrose (S) on moisture sorption, deliquescence, and glass transition (Tg) properties of powder blends was investigated. Individual components and binary mixtures of four different molecular weight MDs with sucrose in 1:1 w/w ratios were exposed to various relative humidity (RH) environments and their equilibrium and dynamic moisture contents were monitored. The deliquescence point (RH0) and dissolution behavior of sucrose alone and in blends was also monitored by polarized light microscopy and second harmonic generation imaging. In S:MD blends, the deliquescence RH of sucrose was lower than the RH0 of sucrose alone, and synergistic moisture sorption also occurred at RHs lower than the RH0. Intimate contact of sucrose crystals with the amorphous MDs resulted in complete dissolution of sucrose at RH < RH0. When blends were stored at conditions exceeding the Tg of the individual MDs (25 °C and 60%, 49% and 34%RH for MD21, MD29 and MD40, respectively), the Tg of the blends was lower than that of individual MDs. Thus, co-formulation of amorphous MDs with crystalline sucrose sensitizes the blend to moisture, potentially leading to deleterious changes in the formulation if storage conditions are not adequately controlled. PMID:23477494

  8. Rats' preferences for high fructose corn syrup vs. sucrose and sugar mixtures.

    PubMed

    Ackroff, Karen; Sclafani, Anthony

    2011-03-28

    High fructose corn syrup (HFCS) has replaced sucrose in many food products, which has prompted research comparing these two sweeteners in rodents. The present study examined the relative palatability of HFCS and sucrose for rats, offering 11% carbohydrate solutions to match the content of common beverages for human consumption. The animals initially preferred HFCS to sucrose but after separate experience with each solution they switched to sucrose preference. Approximating the composition of HFCS with a mixture of fructose and glucose (55:45) yielded a solution that was less attractive than sucrose or HFCS. However, HFCS contains a small amount of glucose polymers, which are very attractive to rats. A 55:42:3 mixture of fructose, glucose and glucose polymers (Polycose) was equally preferred to HFCS and was treated similarly to HFCS in comparisons vs. sucrose. Post-oral effects of sucrose, which is 50% fructose and 50% glucose, may be responsible for the shift in preference with experience. This shift, and the relatively small magnitude of differences in preference for HFCS and sucrose, suggest that palatability factors probably do not contribute to any possible difference in weight gain responses to these sweeteners.

  9. Functional characterization of the sucrose isomerase responsible for trehalulose production in plant-associated Pectobacterium species.

    PubMed

    Nam, Cheon-Hyeon; Seo, Dong-Ho; Jung, Jong-Hyun; Koh, Young-Jin; Jung, Jae-Sung; Heu, Sunggi; Oh, Chang-Sik; Park, Cheon-Seok

    2014-02-05

    Fifty-three plant-associated microorganisms were investigated for their ability to convert sucrose to its isomers. These microorganisms included one Dickeya zeae isolate and 7 Enterobacter, 3 Pantoea, and 43 Pectobacterium species. Eleven out of the 53 strains (21%) showed the ability to transform sucrose to isomaltulose and trehalulose. Among those, Pectobacterium carotovorum KKH 3-1 showed the highest bioconversion yield (97.4%) from sucrose to its isomers. In this strain, the addition of up to 14% sucrose in the medium enhanced sucrose isomerase (SIase) production. The SIase activity at 14% sucrose (47.6 U/mg dcw) was about 3.6-fold higher than that of the negative control (13.3 U/mg dcw at 0% sucrose). The gene encoding SIase, which is comprised a 1776 bp open reading frame (ORF) encoding 591 amino acids, was cloned from P. carotovorum KKH 3-1 and expressed in Escherichia coli. The recombinant SIase (PCSI) was shown to have optimum activity at pH 6.0 and 40 °C. The reaction temperature significantly affected the ratio of sucrose isomers produced by PCSI. The amount of trehalulose increased from 47.5% to 79.1% as temperature was lowered from 50 °C to 30 °C, implying that SIase activity can be controlled by reaction temperature.

  10. Repeated Cocaine Experience Facilitates Sucrose-Reinforced Operant Responding in Enriched and Isolated Rats

    ERIC Educational Resources Information Center

    Klein, Emily D.; Gehrke, Brenda J.; Green, Thomas A.; Zentall, Thomas R.; Bardo, Michael T.

    2007-01-01

    The purpose of the present experiment was to determine whether repeated cocaine exposure differentially affects sucrose-reinforced operant responding in rats raised in an enriched condition (EC) or an isolated condition (IC). Specifically, the performance of EC and IC rats pressing a lever for sucrose under a high fixed-ratio schedule (FR 30)…

  11. Sugaring the pill: ethics and uncertainties in the use of sucrose for newborn infants.

    PubMed

    Wilkinson, Dominic J C; Savulescu, Julian; Slater, Rebeccah

    2012-07-01

    Sucrose is widely used for the management of procedural pain in newborn infants, including capillary blood sampling, venepuncture, and vascular cannulation. Multiple randomized controlled trials have demonstrated that sweet-tasting solutions reduce behavioral responses to acute painful stimuli. It has been claimed that sucrose should be a standard of care in neonatal units and that further placebo-controlled trials of sucrose are unnecessary and unethical. However, recently published data cast doubt on the analgesic properties of sucrose. We review this new evidence and analyze the philosophical and ethical questions that it raises, including the "problem of other minds." Sugar may be better understood not as an analgesic, removing or relieving pain, but as a compensating pleasure. There is a need for further research on the mechanism of sucrose's effect on pain behavior and on the long-term effects of sucrose treatment. Such trials will require comparison with placebo or with other interventions. Given uncertainty about the benefit of sucrose, it may be wise to use alternative analgesics or nonpharmacological interventions where these are available and appropriate. Sucrose may not be the answer to procedural pain in newborns.

  12. An in vivo invertebrate evaluation system for identifying substances that suppress sucrose-induced postprandial hyperglycemia

    PubMed Central

    Matsumoto, Yasuhiko; Ishii, Masaki; Sekimizu, Kazuhisa

    2016-01-01

    Sucrose is a major sweetener added to various foods and beverages. Excessive intake of sucrose leads to increases in blood glucose levels, which can result in the development and exacerbation of lifestyle-related diseases such as obesity and diabetes. In this study, we established an in vivo evaluation system using silkworms to explore substances that suppress the increase in blood glucose levels caused by dietary intake of sucrose. Silkworm hemolymph glucose levels rapidly increased after intake of a sucrose-containing diet. Addition of acarbose or voglibose, α-glycosidase inhibitors clinically used for diabetic patients, suppressed the dietary sucrose-induced increase in the silkworm hemolymph glucose levels. Screening performed using the sucrose-induced postprandial hyperglycemic silkworm model allowed us to identify some lactic acid bacteria that inhibit the increase in silkworm hemolymph glucose levels caused by dietary intake of sucrose. The inhibitory effects of the Lactococcus lactis #Ll-1 bacterial strain were significantly greater than those of different strains of lactic acid bacteria. No effect of the Lactococcus lactis #Ll-1 strain was observed in silkworms fed a glucose diet. These results suggest that the sucrose diet-induced postprandial hyperglycemic silkworm is a useful model for evaluating chemicals and lactic acid bacteria that suppress increases in blood glucose levels. PMID:27194587

  13. Sucrose regulation of ADP-glucose pyrophosphorylase subunit genes transcript levels in leaves and fruits

    NASA Technical Reports Server (NTRS)

    Li, Xiangyang; Xing, Jinpeng; Gianfagna, Thomas J.; Janes, Harry W.

    2002-01-01

    ADP-glucose pyrophosphorylase (AGPase, EC2.7.7.27) is a key regulatory enzyme in starch biosynthesis. The enzyme is a heterotetramer with two S and two B subunits. In tomato, there are three multiple forms of the S subunit gene. Agp S1, S2 and B are highly expressed in fruit from 10 to 25 days after anthesis. Agp S3 is only weakly expressed in fruit. Sucrose significantly elevates expression of Agp S1, S2 and B in both leaves and fruits. Agp S1 exhibits the highest degree of regulation by sucrose. In fact, sucrose may be required for Agp S1 expression. For excised leaves incubated in water, no transcripts for Agp S1 could be detected in the absence of sucrose, whereas it took up to 16 h in water before transcripts were no longer detectable for Agp S2 and B. Neither Agp S3 nor the tubulin gene is affected by sucrose, demonstrating that this response is specifically regulated by a carbohydrate metabolic signal, and is not due to a general increase in metabolism caused by sucrose treatment. Truncated versions of the promoter for Agp S1 indicate that a specific region 1.3-3.0 kb upstream from the transcription site is responsible for sucrose sensitivity. This region of the S1 promoter contains several cis-acting elements present in the promoters of other genes that are also regulated by sucrose. c2002 Elsevier Science Ireland Ltd. All rights reserved.

  14. Octopamine indirectly affects proboscis extension response habituation in Drosophila melanogaster by controlling sucrose responsiveness.

    PubMed

    Scheiner, Ricarda; Steinbach, Anne; Claßen, Gerbera; Strudthoff, Nicole; Scholz, Henrike

    2014-10-01

    Octopamine is an important neurotransmitter in insects with multiple functions. Here, we investigated the role of this amine in a simple form of learning (habituation) in the fruit fly Drosophila melanogaster. Specifically, we asked if octopamine is necessary for normal habituation of a proboscis extension response (PER) to different sucrose concentrations. In addition, we analyzed the relationship between responsiveness to sucrose solutions applied to the tarsus and habituation of the proboscis extension response in the same individual. The Tyramine-β-hydroxylase (Tβh) mutant lacks the enzyme catalyzing the final step of octopamine synthesis. This mutant was significantly less responsive to sucrose than controls. The reduced responsiveness directly led to faster habituation. Systemic application of octopamine or induction of octopamine synthesis by Tβh expression in a cluster of octopaminergic neurons within the suboesophageal ganglion restored sucrose responsiveness and habituation of octopamine mutants to control level. Further analyses imply that the reduced sucrose responsiveness of Tβh mutants is related to a lower sucrose preference, probably due to a changed carbohydrate metabolism, since Tβh mutants survived significantly longer under starved conditions. These findings suggest a pivotal role for octopamine in regulating sucrose responsiveness in fruit flies. Further, octopamine indirectly influences non-associative learning and possibly associative appetitive learning by regulating the evaluation of the sweet component of a sucrose reward.

  15. The analgesic effect of sucrose in full term infants: a randomised controlled trial.

    PubMed Central

    Haouari, N.; Wood, C.; Griffiths, G.; Levene, M.

    1995-01-01

    OBJECTIVE--To evaluate the effects of different sucrose concentrations on measures of neonatal pain. DESIGN--Randomised, double blind, placebo controlled trial of sterile water (control) or one of three solutions of sucrose--namely, 12.5%, 25%, and 50% wt/vol. SETTING--Postnatal ward. PATIENTS--60 healthy infants of gestational age 37-42 weeks and postnatal age 1-6 days randomised to receive 2 ml of one of the four solutions on to the tongue two minutes before heel prick sampling for serum bilirubin concentrations. MAIN OUTCOME MEASURE--Duration of crying over the first three minutes after heel prick. RESULTS--There was a significant reduction in overall crying time and heart rate after three minutes in the babies given 50% sucrose as compared with controls. This was maximal one minute after heel prick in the 50% sucrose group and became statistically significant in the 25% sucrose group at two minutes. There was a significant trend for a reduction in crying time with increasing concentrations of sucrose over the first three minutes. CONCLUSION--Concentrated sucrose solution seems to reduce crying and the autonomic effects of a painful procedure in healthy normal babies. Sucrose may be a useful and safe analgesic for minor procedures in neonates. PMID:7787595

  16. Pronounced Phenotypic Changes in Transgenic Tobacco Plants Overexpressing Sucrose Synthase May Reveal a Novel Sugar Signaling Pathway

    PubMed Central

    Nguyen, Quynh Anh; Luan, Sheng; Wi, Seung G.; Bae, Hanhong; Lee, Dae-Seok; Bae, Hyeun-Jong

    2016-01-01

    Soluble sugars not only serve as nutrients, but also act as signals for plant growth and development, but how sugar signals are perceived and translated into physiological responses in plants remains unclear. We manipulated sugar levels in transgenic plants by overexpressing sucrose synthase (SuSy), which is a key enzyme believed to have reversible sucrose synthesis and sucrose degradation functions. The ectopically expressed SuSy protein exhibited sucrose-degrading activity, which may change the flux of sucrose demand from photosynthetic to non-photosynthetic cells, and trigger an unknown sucrose signaling pathway that lead to increased sucrose content in the transgenic plants. An experiment on the transition from heterotrophic to autotrophic growth demonstrated the existence of a novel sucrose signaling pathway, which stimulated photosynthesis, and enhanced photosynthetic synthesis of sucrose, which was the direct cause or the sucrose increase. In addition, a light/dark time treatment experiment, using different day length ranges for photosynthesis/respiration showed the carbohydrate pattern within a 24-h day and consolidated the role of sucrose signaling pathway as a way to maintain sucrose demand, and indicated the relationships between increased sucrose and upregulation of genes controlling development of the shoot apical meristem (SAM). As a result, transgenic plants featured a higher biomass and a shorter time required to switch to reproduction compared to those of control plants, indicating altered phylotaxis and more rapid advancement of developmental stages in the transgenic plants. PMID:26793204

  17. Decreased sucrose content triggers starch breakdown and respiration in stored potato tubers (Solanum tuberosum).

    PubMed

    Hajirezaei, Mohammad-Reza; Börnke, Frederik; Peisker, Martin; Takahata, Yasuhiro; Lerchl, Jens; Kirakosyan, Ara; Sonnewald, Uwe

    2003-01-01

    To change the hexose-to-sucrose ratio within phloem cells, yeast-derived cytosolic invertase was expressed in transgenic potato (Solanum tuberosum cv. Desirée) plants under control of the rolC promoter. Vascular tissue specific expression of the transgene was verified by histochemical detection of invertase activity in tuber cross-sections. Vegetative growth and tuber yield of transgenic plants was unaltered as compared to wild-type plants. However, the sprout growth of stored tubers was much delayed, indicating impaired phloem-transport of sucrose towards the developing bud. Biochemical analysis of growing tubers revealed that, in contrast to sucrose levels, which rapidly declined in growing invertase-expressing tubers, hexose and starch levels remained unchanged as compared to wild-type controls. During storage, sucrose and starch content declined in wild-type tubers, whereas glucose and fructose levels remained unchanged. A similar response was found in transgenic tubers with the exception that starch degradation was accelerated and fructose levels increased slightly. Furthermore, changes in carbohydrate metabolism were accompanied by an elevated level of phosphorylated intermediates, and a stimulated rate of respiration. Considering that sucrose breakdown was restricted to phloem cells it is concluded that, in response to phloem-associated sucrose depletion or hexose elevation, starch degradation and respiration is triggered in parenchyma cells. To study further whether elevated hexose and/or hexose-phosphates or decreased sucrose levels are responsible for the metabolic changes observed, sucrose content was decreased by tuber-specific expression of a bacterial sucrose isomerase. Sucrose isomerase catalyses the reversible conversion of sucrose into palatinose, which is not further metabolizable by plant cells. Tubers harvested from these plants were found to accumulate high levels of palatinose at the expense of sucrose. In addition, starch content decreased

  18. Age-dependency of analgesia elicited by intraoral sucrose in acute and persistent pain models.

    PubMed

    Anseloni, Vanessa C Z; Weng, H-R; Terayama, R; Letizia, David; Davis, Barry J; Ren, Ke; Dubner, Ronald; Ennis, Matthew

    2002-05-01

    Treatment of pain in newborns is associated with problematic drug side effects. Previous studies demonstrate that an intraoral infusion of sucrose and other sweet components of mother's milk are effective in alleviating pain in infant rats and humans. These findings are of considerable significance, as sweet tastants are used in pain and stress management in a number of clinical procedures performed in human infants. The ability of sweet stimuli to induce analgesia is absent in adult rats, suggesting that this is a developmentally transient phenomenon. However, the age range over which intraoral sucrose is capable of producing analgesia is not known. We investigated the effects of intraoral sucrose (7.5%) on nocifensive withdrawal responses to thermal and mechanical stimuli in naive and inflamed rats at postnatal days (P) P0-21. In some rats, Complete Freund's adjuvant (CFA) was injected in a fore- or hindpaw to produce inflammation. In non-inflamed animals, for noxious thermal stimuli, sucrose-induced analgesia emerged at P3, peaked at P7-10, then progressively declined and was absent at P17. For mechanical forepaw stimuli, sucrose-induced analgesia emerged, and was maximal at approximately P10, then declined and was absent at P17. By contrast, maximal sucrose-induced analgesia for mechanical hindpaw stimuli was delayed (P13) compared to that for the forepaw, although it was also absent at P17. In inflamed animals, sucrose reduced hyperesthesia and hyperalgesia assessed with mechanical stimuli. Sucrose-induced analgesia in inflamed animals was initially present at P3 for the forepaw and P13 for the hindpaw, and was absent by P17 for both limbs. Intraoral sucrose produced significantly greater effects on responses in fore- and hindpaws in inflamed rats than in naive rats indicating that it reduces hyperalgesia and allodynia beyond its effects on responses in naive animals. These findings support the hypothesis that sucrose has a selective influence on analgesic

  19. Intermediate range order in alkaline borate glasses

    NASA Astrophysics Data System (ADS)

    Crupi, C.; Carini, G.; Ruello, G.; D'Angelo, G.

    2016-03-01

    We describe the neutron diffraction patterns of a series of alkaline borate glasses at different metal oxide content. Strong differences are observed in the intermediate range order as a function of the specific alkaline ion and of its concentration. On these results, we propose that the first sharp diffraction peak arises from correlations of atoms of voids and show that the compositional variation of this peak intensity in alkaline borate glasses is due to changes in the distribution of void sizes within the three-dimensional network. We argue that our interpretation in terms of interstitial (empty and/or filled) voids, having different sizes, provides a general explanation for all anomalous behaviours revealed for the first sharp diffraction peak.

  20. ( sup 14 C)-Sucrose uptake by guard cell protoplasts of pisum sativum, argenteum mutant

    SciTech Connect

    Rohrig, K.; Raschke, K. )

    1991-05-01

    Guard cells rely on import for their supply with reduced carbon. The authors tested by silicone oil centrifugation the ability of guard cell protoplasts to accumulated ({sup 14}C)-sucrose. Uptake rates were corrected after measurement of {sup 14}C-sorbitol and {sup 3}H{sub 2}O spaces. Sucrose uptake followed biphasic kinetics, with a high-affinity component below 1 mM external sucrose (apparent K{sub m} 0.8 mM at 25C) and a low-affinity nonsaturable component above. Uptake depended on pH (optimum at pH 5.0). Variations in the concentrations of external KCl, CCCP, and valinomycin indicated that about one-half of the sucrose uptake rate could be related to an electrochemical gradient across the plasmalemma. Total uptake rates measured at 5 mM external sucrose seem to be sufficient to replenish emptied plastids with starch within a few hours.

  1. Calcium is essential for fructan synthesis induction mediated by sucrose in wheat.

    PubMed

    Martínez-Noël, Giselle; Tognetti, Jorge; Nagaraj, Vinay; Wiemken, Andres; Pontis, Horacio

    2006-12-01

    The role of Ca(2+) in the induction of enzymes involved in fructan synthesis (FSS) mediated by sucrose was studied in wheat (Triticum aestivum). Increase of FSS enzyme activity and induction of the expression of their coding genes by sucrose were inhibited in leaf blades treated with chelating agents (EDTA, EGTA and BAPTA). Ca(2+) channel blockers (lanthanum chloride and ruthenium red) also inhibited the FSS response to sucrose, suggesting the participation of Ca(2+) from both extra- and intra- cellular stores. Sucrose induced a rapid Ca(2+) influx into the cytosol in wheat leaf and root tissues, shown with the Ca(2+ )sensitive fluorescent probe Fluo-3/AM ester. Our results support the hypothesis that calcium is a component of the sucrose signaling pathway that leads to the induction of fructan synthesis.

  2. A study of the direct dimethyl ether fuel cell using alkaline anolyte

    NASA Astrophysics Data System (ADS)

    Xu, Kan; Lao, Shao Jiang; Qin, Hai Ying; Liu, Bin Hong; Li, Zhou Peng

    The electrooxidation behavior of dimethyl ether (DME) dissolved in acidic, neutral or alkaline anolyte has been studied. The cyclic voltammetry measurements reveal that DME in alkaline anolyte demonstrates higher electrooxidation reactivity than that in acidic or neutral anolyte. With increasing the NaOH concentration in the anolyte, the electrooxidation reactivity of DME can be further improved. Direct dimethyl ether fuel cells (DDFCs) are assembled by using Nafion membrane as the electrolyte, Pt/C as the cathode catalyst, and Pt-Ru/C as the anode catalyst. It is found that the use of alkaline anolyte can significantly improve the performance of DDFCs. A maximum power density of 60 mW cm -2 has been achieved when operating the DDFC at 80 °C under ambient pressure.

  3. EMF radiations (1800 MHz)-inhibited early seedling growth of maize (Zea mays) involves alterations in starch and sucrose metabolism.

    PubMed

    Kumar, Arvind; Singh, Harminder Pal; Batish, Daizy R; Kaur, Shalinder; Kohli, Ravinder Kumar

    2016-07-01

    The present study investigated the impact of 1800-MHz electromagnetic field radiations (EMF-r), widely used in mobile communication, on the growth and activity of starch-, sucrose-, and phosphate-hydrolyzing enzymes in Zea mays seedlings. We exposed Z. mays to modulated continuous wave homogenous EMF-r at specific absorption rate (SAR) of 1.69±0.0 × 10(-1) W kg(-1) for ½, 1, 2, and 4 h. The analysis of seedlings after 7 days revealed that short-term exposure did not induce any significant change, while longer exposure of 4 h caused significant growth and biochemical alterations. There was a reduction in the root and coleoptile length with more pronounced effect on coleoptile growth (23 % reduction on 4-h exposure). The contents of photosynthetic pigments and total carbohydrates declined by 13 and 18 %, respectively, in 4-h exposure treatments compared to unexposed control. The activity of starch-hydrolyzing enzymes-α- and β-amylases-increased by ∼92 and 94 %, respectively, at an exposure duration of 4 h, over that in the control. In response to 4-h exposure treatment, the activity of sucrolytic enzymes-acid invertases and alkaline invertases-was increased by 88 and 266 %, whereas the specific activities of phosphohydrolytic enzymes (acid phosphatases and alkaline phosphatases) showed initial increase up to ≤2 h duration and then declined at >2 h exposure duration. The study concludes that EMF-r-inhibited seedling growth of Z. mays involves interference with starch and sucrose metabolism.

  4. An efficient protocol to enhance the extracellular production of recombinant protein from Escherichia coli by the synergistic effects of sucrose, glycine, and Triton X-100.

    PubMed

    Bao, Ru-Meng; Yang, Hong-Ming; Yu, Chang-Mei; Zhang, Wei-Fen; Tang, Jin-Bao

    2016-10-01

    Targeting recombinant proteins at highly extracellular production in the culture medium of Escherichia coli presents a significant advantage over cytoplasmic or periplasmic expression. In this work, a recombinant protein between ZZ protein and alkaline phosphatase (rZZ-AP) was constructed. Because rZZ-AP has the IgG-binding capacity and enzymatic activity, it can serve as an immunoreagent in immunoassays. However, only a very small portion of rZZ-AP is generally secreted into the aqueous medium under conventional cultivation procedure. Hence, we emphasized on the optimization of the culture procedures and attempted to dramatically enhance the yield of extracellular rZZ-AP from E. coli HB101 host cells by adding sucrose, glycine, and Triton X-100 in the culture medium. Results showed that the extracellular production of rZZ-AP in the culture medium containing 5% sucrose, 1% glycine, and 1% Triton X-100 was 18.6 mg/l, which was 18.6-fold higher than that without the three chemicals. And the β-galactosidase activity test showed that the increased extracellular rZZ-AP was not due to cell lysis. Further analysis suggested a significant interaction effect among the three chemicals for the enhancement of extracellular production. Ultrastructural analysis indicated that the enhancement may be due to the influence of sucrose, glycine, and Triton X-100 on the periplasmic osmolality, permeability, or integrity of the cell wall, respectively. This proposed approach presents a simple strategy to enhance the extracellular secretion of recombinant proteins in the E. coli system at the process of cell cultivation.

  5. Laser direct write of planar alkaline microbatteries

    NASA Astrophysics Data System (ADS)

    Arnold, C. B.; Kim, H.; Piqué, A.

    We are developing a laser engineering approach to fabricate and optimize alkaline microbatteries in planar geometries. The laser direct-write technique enables multicapability for adding, removing and processing material and provides the ability to pattern complicated structures needed for fabricating complete microbattery assemblies. In this paper, we demonstrate the production of planar zinc-silver oxide alkaline cells under ambient conditions. The microbattery cells exhibit 1.55-V open-circuit potentials, as expected for the battery chemistry, and show a flat discharge behavior under constant-current loads. High capacities of over 450 μAhcm-2 are obtained for 5-mm2 microbatteries.

  6. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  7. Sucrose importation into laticifers of Hevea brasiliensis, in relation to ethylene stimulation of latex production

    PubMed Central

    Dusotoit-Coucaud, Anaïs; Brunel, Nicole; Kongsawadworakul, Panida; Viboonjun, Unchera; Lacointe, André; Julien, Jean-Louis; Chrestin, Hervé; Sakr, Soulaïman

    2009-01-01

    Background and Aims The major economic product of Hevea brasiliensis is a rubber-containing cytoplasm (latex), which flows out of laticifers (latex cells) when the bark is tapped. The latex yield is stimulated by ethylene. Sucrose, the unique precursor of rubber synthesis, must cross the plasma membrane through specific sucrose transporters before being metabolized in the laticifers. The relative importance of sucrose transporters in determining latex yield is unknown. Here, the effects of ethylene (by application of Ethrel®) on sucrose transporter gene expression in the inner bark tissues and latex cells of H. brasiliensis are described. Methods Experiments, including cloning sucrose transporters, real time RT-PCR and in situ hybridization, were carried out on virgin (untapped) trees, treated or untreated with the latex yield stimulant Ethrel. Key Results Seven putative full-length cDNAs of sucrose transporters were cloned from a latex-specific cDNA library. These transporters belong to all SUT (sucrose transporter) groups and differ by their basal gene expression in latex and inner soft bark, with a predominance of HbSUT1A and HbSUT1B. Of these sucrose transporters, only HbSUT1A and HbSUT2A were distinctly increased by ethylene. Moreover, this increase was shown to be specific to laticifers and to ethylene application. Conclusion The data and all previous information on sucrose transport show that HbSUT1A and HbSUT2A are related to the increase in sucrose import into laticifers, required for the stimulation of latex yield by ethylene in virgin trees. PMID:19567416

  8. Sucrose transporters in two members of the Scrophulariaceae with different types of transport sugar.

    PubMed

    Knop, C; Voitsekhovskaja, O; Lohaus, G

    2001-05-01

    In order to study differences between sugar transport in oligosaccharide-translocating and sucrose-translocating species, two members of the Scrophulariaceae, Asarina barclaiana Pennell and Alonsoa meridionalis O. Kuntze, were analysed regarding minor-vein anatomy, sugar concentrations in leaves and phloem sap, and expression of sucrose transporters. The minor veins of Asarina barclaiana possess mainly transfer cells and modified intermediary cells and those of Alonsoa meridionalis have intermediary cells and ordinary companion cells. Phloem sap from these plants was collected by the laser-aphid-stylet technique. The main carbon transport forms in Asarina were sucrose and in Alonsoa raffinose and stachyose. The sum of the carbohydrate concentrations in the phloem sap of both species was as high as that in apoplastic phloem loaders. In Asarina the ratio of the sucrose concentration in the phloem to that in the cytosol of source cells was about 35 and the corresponding ratio in Alonsoa was about two. Sucrose transporter cDNAs were isolated from leaves of both species. By means of semi-quantitative reverse transcription-polymerase chain reaction, sucrose transporter mRNA was detected in different organs and also in the phloem sap. This is the first time that sucrose transporters have been found in oligosaccharide-translocating species and that the mRNA of these sucrose transporters has been localized directly in the phloem sap. Taken together, our observations indicate that Asarina is an apoplastic phloem loader, while the results for Alonsoa are ambiguous: some properties are typical of the symplastic phloem-loading mechanism, but probably a sucrose transporter is involved in loading and/or retrieval of sucrose into the phloem.

  9. Escherichia coli W shows fast, highly oxidative sucrose metabolism and low acetate formation.

    PubMed

    Arifin, Yalun; Archer, Colin; Lim, SooA; Quek, Lake-Ee; Sugiarto, Haryadi; Marcellin, Esteban; Vickers, Claudia E; Krömer, Jens O; Nielsen, Lars K

    2014-11-01

    Sugarcane is the most efficient large-scale crop capable of supplying sufficient carbon substrate, in the form of sucrose, needed during fermentative feedstock production. However, sucrose metabolism in Escherichia coli is not well understood because the two most common strains, E. coli K-12 and B, do not grow on sucrose. Here, using a sucrose utilizing strain, E. coli W, we undertake an in-depth comparison of sucrose and glucose metabolism including growth kinetics, metabolite profiling, microarray-based transcriptome analysis, labelling-based proteomic analysis and (13)C-fluxomics. While E. coli W grew comparably well on sucrose and glucose integration of the omics, datasets showed that during growth on each carbon source, metabolism was distinct. The metabolism was generally derepressed on sucrose, and significant flux rearrangements were observed in central carbon metabolism. These included a reduction in the flux of the oxidative pentose phosphate pathway branch, an increase in the tricarboxylic acid cycle flux and a reduction in the glyoxylate shunt flux due to the dephosphorylation of isocitrate dehydrogenase. But unlike growth on other sugars that induce cAMP-dependent Crp regulation, the phosphoenol-pyruvate-glyoxylate cycle was not active on sucrose. Lower acetate accumulation was also observed in sucrose compared to glucose cultures. This was linked to induction of the acetate catabolic genes actP and acs and independent of the glyoxylic shunt. Overall, the cells stayed highly oxidative. In summary, sucrose metabolism was fast, efficient and led to low acetate accumulation making it an ideal carbon source for industrial fermentation with E. coli W.

  10. Transcriptome Analysis of Sucrose Metabolism during Bulb Swelling and Development in Onion (Allium cepa L.).

    PubMed

    Zhang, Chunsha; Zhang, Hongwei; Zhan, Zongxiang; Liu, Bingjiang; Chen, Zhentai; Liang, Yi

    2016-01-01

    Allium cepa L. is a widely cultivated and economically significant vegetable crop worldwide, with beneficial dietary and health-related properties, but its sucrose metabolism is still poorly understood. To analyze sucrose metabolism during bulb swelling, and the development of sweet taste in onion, a global transcriptome profile of onion bulbs was undertaken at three different developmental stages, using RNA-seq. A total of 79,376 unigenes, with a mean length of 678 bp, was obtained. In total, 7% of annotated Clusters of Orthologous Groups (COG) were involved in carbohydrate transport and metabolism. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, "starch and sucrose metabolism" (147, 2.40%) constituted the primary metabolism pathway in the integrated library. The expression of sucrose transporter genes was greatest during the early-swelling stage, suggesting that sucrose transporters (SUTs) participated in sucrose metabolism mainly at an early stage of bulb development. A gene-expression analysis of the key enzymes of sucrose metabolism suggested that sucrose synthase, cell wall invertase, and invertase were all likely to participate in the hydrolysis of sucrose, generating glucose, and fructose. In addition, trehalose was hydrolyzed to two molecules of glucose by trehalase. From 15 to 40 days after swelling (DAS), both the glucose and fructose contents of bulbs increased, whereas the sucrose content decreased. The growth rate between 15 and 30 DAS was slower than that between 30 and 40 DAS, suggesting that the latter was a period of rapid expansion. The dataset generated by our transcriptome profiling will provide valuable information for further research.

  11. Transcriptome Analysis of Sucrose Metabolism during Bulb Swelling and Development in Onion (Allium cepa L.)

    PubMed Central

    Zhang, Chunsha; Zhang, Hongwei; Zhan, Zongxiang; Liu, Bingjiang; Chen, Zhentai; Liang, Yi

    2016-01-01

    Allium cepa L. is a widely cultivated and economically significant vegetable crop worldwide, with beneficial dietary and health-related properties, but its sucrose metabolism is still poorly understood. To analyze sucrose metabolism during bulb swelling, and the development of sweet taste in onion, a global transcriptome profile of onion bulbs was undertaken at three different developmental stages, using RNA-seq. A total of 79,376 unigenes, with a mean length of 678 bp, was obtained. In total, 7% of annotated Clusters of Orthologous Groups (COG) were involved in carbohydrate transport and metabolism. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, “starch and sucrose metabolism” (147, 2.40%) constituted the primary metabolism pathway in the integrated library. The expression of sucrose transporter genes was greatest during the early-swelling stage, suggesting that sucrose transporters (SUTs) participated in sucrose metabolism mainly at an early stage of bulb development. A gene-expression analysis of the key enzymes of sucrose metabolism suggested that sucrose synthase, cell wall invertase, and invertase were all likely to participate in the hydrolysis of sucrose, generating glucose, and fructose. In addition, trehalose was hydrolyzed to two molecules of glucose by trehalase. From 15 to 40 days after swelling (DAS), both the glucose and fructose contents of bulbs increased, whereas the sucrose content decreased. The growth rate between 15 and 30 DAS was slower than that between 30 and 40 DAS, suggesting that the latter was a period of rapid expansion. The dataset generated by our transcriptome profiling will provide valuable information for further research. PMID:27713754

  12. Real-time materials evolution visualized within intact cycling alkaline batteries

    SciTech Connect

    Gallaway, JW; Erdonmez, CK; Zhong, Z; Croft, M; Sviridov, LA; Sholklapper, TZ; Turney, DE; Banerjee, S; Steingart, DA

    2014-01-01

    The scientific community has focused on the problem of inexpensive, safe, and sustainable large-scale electrical energy storage, which is needed for a number of emerging societal reasons such as stabilizing intermittent renewables-based generation like solar and wind power. The materials used for large-scale storage will need to be low cost, earth-abundant, and safe at the desired scale. The Zn-MnO2 "alkaline" battery chemistry is associated with one-time use, despite being rechargeable. This is due to material irreversibilities that can be triggered in either the anode or cathode. However, as Zn and MnO2 have high energy density and low cost, they are economically attractive even at limited depth of discharge. As received, a standard bobbin-type alkaline cell costs roughly $20 per kW h. The U. S. Department of Energy ARPA-E $100 per kW h cost target for grid storage is thus close to the cost of alkaline consumer primary cells if re-engineered and/or cycled at 5-20% nominal capacity. Herein we use a deeply-penetrating in situ technique to observe ZnO precipitation near the separator in an alkaline cell anode cycled at 5% DOD, which is consistent with cell failures observed at high cycle life. Alkaline cells designed to avoid such causes of cell failure could serve as a low-cost baseload for large-scale storage.

  13. Investigation on phase transformation mechanism of zeolite NaY under alkaline hydrothermal conditions

    SciTech Connect

    Li, Peng Ding, Tian Liu, Liping Xiong, Guang

    2013-12-15

    The phase transformation mechanism of zeolite NaY under alkaline hydrothermal conditions was investigated by UV Raman spectroscopy, X-ray diffraction, X-ray fluorescence and scanning electron microscopy techniques. The results revealed that the products and transformation rate are dependent on the alkalinities. All of the starting and resulting zeolites are constructed with the 4-ring and 6-ring secondary building units. The products have lower Si/Al ratio, higher framework density and smaller pore size, which are more stable under alkaline hydrothermal condition. During the phase transformation the fragments of faujasite are formed, then the fragments combine to form different zeolites depending on basicity. Zeolite NaY crystals are consumed as the reservoir for the transformation products during the recrystallization process. For the first time, a 4-membered ring intermediate was found at the early stage of the recrystallization process. A cooperative interaction of liquid and solid phases is required for inducing the phase transformation. - Graphical Abstract: Phase transformation of NaY zeolite under alkaline hydrothermal condition is achieved by the cooperative interaction of the liquid and solid phases. A 4-membered ring species is an intermediate for recrystallization process. Highlights: • The products and transformation rate are dependent on the alkalinity. • A 4-membered ring species is an intermediate for recrystallization process. • A cooperative interaction of liquid and solid phases is required.

  14. Biochemical Stabilization of Glucagon at Alkaline pH

    PubMed Central

    Jackson, Melanie A.; Castle, Jessica R.; El Youssef, Joseph; Bakhtiani, Parkash A.; Bergstrom, Colin P.; Carroll, Julie M.; Breen, Matthew E.; Leonard, Gerald L.; David, Larry L.; Roberts, Charles T.; Ward, W. Kenneth

    2014-01-01

    Abstract Background: For patients with type 1 diabetes mellitus, a bihormonal artificial endocrine pancreas system utilizing glucagon and insulin has been found to stabilize glycemic control. However, commercially available formulations of glucagon cannot currently be used in such systems because of physical instability characterized by aggregation and chemical degradation. Storing glucagon at pH 10 blocks protein aggregation but results in chemical degradation. Reductions in pH minimize chemical degradation, but even small reductions increase protein aggregation. We hypothesized that common pharmaceutical excipients accompanied by a new excipient would inhibit glucagon aggregation at an alkaline pH. Methods and Results: As measured by tryptophan intrinsic fluorescence shift and optical density at 630 nm, protein aggregation was indeed minimized when glucagon was formulated with curcumin and albumin. This formulation also reduced chemical degradation, measured by liquid chromatography with mass spectrometry. Biological activity was retained after aging for 7 days in an in vitro cell-based bioassay and also in Yorkshire swine. Conclusions: Based on these findings, a formulation of glucagon stabilized with curcumin, polysorbate-80, l-methionine, and albumin at alkaline pH in glycine buffer may be suitable for extended use in a portable pump in the setting of a bihormonal artificial endocrine pancreas. PMID:24968220

  15. The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?

    PubMed Central

    Schwalfenberg, Gerry K.

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine. PMID:22013455

  16. The alkaline diet: is there evidence that an alkaline pH diet benefits health?

    PubMed

    Schwalfenberg, Gerry K

    2012-01-01

    This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

  17. Expression analysis of genes associated with sucrose accumulation in sugarcane (Saccharum spp. hybrids) varieties differing in content and time of peak sucrose storage.

    PubMed

    Chandra, A; Verma, P K; Islam, M N; Grisham, M P; Jain, R; Sharma, A; Roopendra, K; Singh, K; Singh, P; Verma, I; Solomon, S

    2015-05-01

    Sucrose synthesis/accumulation in sugarcane is a complex process involving many genes and regulatory sequences that control biochemical events in source-sink tissues. Among these, sucrose synthase (SuSy), sucrose phosphate synthase (SPS), soluble acid (SAI) and cell wall (CWI) invertases are important. Expression of these enzymes was compared in an early (CoJ64) and late (BO91) maturing sugarcane variety using end-point and qRT-PCR. Quantitative RT-PCR at four crop stages revealed high CWI expression in upper internodes of CoJ64, which declined significantly in both top and bottom internodes with maturity. In BO91, CWI expression was high in top and bottom internodes and declined significantly only in top internodes as the crop matured. Overall, CWI expression was higher in CoJ64 than in BO91. During crop growth, there was no significant change in SPS expression in bottom internodes in CoJ64, whereas in BO91 it decreased significantly. Apart from a significant decrease in expression of SuSy in mature bottom internodes of BO91, there was no significant change. Similar SAI expression was observed with both end-point and RT-PCR, except for significantly increased expression in top internodes of CoJ64 with maturity. SAI, being a major sucrose hydrolysing enzyme, was also monitored with end-point PCR expression in internode tissues of CoJ64 and BO91, with higher expression of SAI in BO91 at early crop stages. Enzyme inhibitors, e.g. manganese chloride (Mn(++) ), significantly suppressed expression of SAI in both early- and late-maturing varieties. Present findings enhance understanding of critical sucrose metabolic gene expression in sugarcane varieties differing in content and time of peak sucrose storage. Thus, through employing these genes, improvement of sugarcane sucrose content is possible.

  18. Use of the Biphasic (13)C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders.

    PubMed

    Opekun, Antone R; Balesh, Albert M; Shelby, Harold T

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase (13)C-sucrose/(13)C-glucose breath test ((13)C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When (13)C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to (13)CO2 is a proportional indicator of sucrase activity. Subsequently, (13)C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). (13)CO2 enrichment recovery ratio from (13)C-sucrose and secondary (13)C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, (13)C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing (13)CO2-breath enrichment with plasma (13)C-glucose enrichment. (13)C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. (13)CO2-breath enrichment correlated with the appearance of (13)C-sucrose-derived glucose in plasma (r (2) = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60', 0.92 at 75', and 0.96 at mean 60'-75' with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60', 0.77 at 75', and 0.76 at mean 60'-75' (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD.

  19. Use of the Biphasic 13C-Sucrose/Glucose Breath Test to Assess Sucrose Maldigestion in Adults with Functional Bowel Disorders

    PubMed Central

    Balesh, Albert M.; Shelby, Harold T.

    2016-01-01

    Sucrase insufficiency has been observed in children with of functional bowel disorders (FBD) and symptoms of dietary carbohydrate intolerance may be indistinguishable from those of FBD. A two-phase 13C-sucrose/13C-glucose breath test (13C-S/GBT) was used to assess sucrase activity because disaccharidase assays are seldom performed in adults. When 13C-sucrose is hydrolyzed to liberate monosaccharides, oxidation to 13CO2 is a proportional indicator of sucrase activity. Subsequently, 13C-glucose oxidation rate was determined after a secondary substrate ingestion (superdose) to adjust for individual habitus effects (Phase II). 13CO2 enrichment recovery ratio from 13C-sucrose and secondary 13C-glucose loads reflect the individualized sucrase activity [Coefficient of Glucose Oxidation for Sucrose (CGO-S)]. To determine if sucrase insufficiency could be a factor in FBD, 13C-S/GBT was validated using subjects with known sucrase gene mutation status by comparing 13CO2-breath enrichment with plasma 13C-glucose enrichment. 13C-S/GBT was used to assess sucrose digestion in FBD patients and asymptomatic controls. 13CO2-breath enrichment correlated with the appearance of 13C-sucrose-derived glucose in plasma (r2 = 0.80). Mean, control group CGO-S-enrichment outcomes were 1.01 at 60′, 0.92 at 75′, and 0.96 at mean 60′–75′ with normal CGO-S defined as >0.85 (95% C.I.). In contrast, FBD patients demonstrated lower CGO-S values of 0.77 at 60′, 0.77 at 75′, and 0.76 at mean 60′–75′ (Chi Square: 6.55; p < 0.01), which points to sucrose maldigestion as a cause of FBD. PMID:27579322

  20. Water vapor absorption into amorphous sucrose-poly(vinyl pyrrolidone) and trehalose-poly(vinyl pyrrolidone) mixtures.

    PubMed

    Zhang, J; Zografi, G

    2001-09-01

    Previous studies from this laboratory suggested that a solution model (Flory-Huggins equation) modified by a free volume model (Vrentas equation) could satisfactorily describe water absorption into an amorphous solid composed of a sugar or a polymer. This paper has extended the studies of single solutes to binary mixtures of trehalose-and sucrose-poly(vinyl pyrrolidone) (trehalose-PVP and sucrose-PVP, respectively) either co-lyophilized or individually lyophilized and then physically mixed. Water vapor absorption isotherms of the binary mixtures were determined at 30 degrees C. Co-lyophilized PVP-sugar mixtures take up essentially the same amount of water as predicted by the weight average of individual isotherms, whereas sugar crystallization is significant retarded in the molecular dispersions. The sugar-PVP interaction, as reflected in the Flory-Huggins chi interaction parameter, was estimated by fitting the high relative pressure (p/p(0)) region of the isotherm, at which the system is in a liquid state, with a three-component Flory-Huggins-type model. The estimated sugar-water PVP-water, and sugar-PVP interaction parameters suggest that the solute-water interactions are not significantly affected by the sugar-PVP interaction; that is, the solute-water interaction parameters in a binary solute system are similar to those in the corresponding single solute systems. Based on these interaction parameters, the sucrose-PVP interaction appears to be stronger than that of trehalose-PVP. Manipulation of the interaction parameters suggest that the water vapor absorption isotherm is not a sensitive indicator of possible sugar-PVP interactions. Density, glass transition temperature, T(g), and the heat capacity change, DeltaC(p), at T(g) were determined to estimate the excess water absorption energy due to the plasticizing effect of water using the structural relaxation model, as described by Vrentas. Results suggest that PVP is a better antiplasticizer for sucrose than for

  1. Evaluation of centrifugation parameters for density gradient experiments by means of a programmable pocket calculator.

    PubMed

    Kreutzfeldt, C

    1980-10-01

    A calculation program is proposed suitable for programmable pocket calculators (e.g. HP series) to estimate s20,w f omega2 dt values from density gradient centrifugation data. The program can be applied to linear or exponential density gradients prepared from sucrose or glycerol solutions spun in zonal rotors or swinging bucket rotors. A wide solute concentration range and temperature range is accounted for. Constants for empirical density calculation of glycerol and sucrose solutions concentrated in % (w/v) are estimated. Experimental verification of the program was carried out.

  2. Experimental model of postprandial hypertriglyceridemia in sucrose-fed rats and the effectiveness of atorvastatin in the model.

    PubMed

    Funatsu, Toshiyuki; Kakuta, Hirotoshi; Takasu, Toshiyuki; Noguchi, Masahiro; Suzuki, Masanori; Miyata, Keiji

    2003-05-01

    Although postprandial hypertriglyceridemia has drawn attention as an independent risk factor of cardiovascular disease, there is no established animal model that shows a physiological transitory change in lipoprotein metabolism after ingestion of a fatty meal. We developed an animal model of postprandial hypertriglyceridemia using sucrose-fed rats, and used this model to evaluate the effect of atorvastatin on this condition. Compared with normal rats, sucrose-fed rats orally loaded with olive oil showed a high and prolonged increase in plasma triglyceride (TG) concentration accompanied by both an increase in TG secretion and decrease in TG clearance. Atorvastatin (30 mg/kg orally) for 2 weeks reduced not only fasting plasma TG concentration, but also the postprandial TG concentration. Atorvastatin also suppressed rates of TG secretion in both chylomicron (CM)-rich (d < 0.96 g/mL) and very-low-density lipoprotein (VLDL) (d = 0.96 to 1.006 g/mL) fractions after oral fat loading. Further, atorvastatin improved the elimination time of exogenous TG emulsion only in the nonfasted, namely, high plasma TG condition. These results indicate that this animal model satisfactorily replicates the postprandial hypertriglyceridemia observed in humans and may therefore be useful in evaluation of lipid-lowering agents. Furthermore, atorvastatin not only improves fasting but also postprandial lipoprotein metabolism, presumably by reducing TG secretion from the liver or intestine or both, and by secondarily increasing TG-rich lipoprotein clearance by eliminating saturation.

  3. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  4. Alkaline electrochemical cells and method of making

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1970-01-01

    Equilibrated cellulose ether membranes of increased electrolytic conductivity for use as separators in concentrated alkaline electrochemical cells are investigated. The method of making such membranes by equilibration to the degree desired in an aqueous alkali solution mantained at a temperature below about 10 C is described.

  5. Kinetics of the alkaline hydrolysis of nitrocellulose.

    PubMed

    Christodoulatos, C; Su, T L; Koutsospyros, A

    2001-01-01

    Cellulose nitrate (nitrocellulose) is an explosive solid substance used in large quantities in various formulations of rocket and gun propellants. Safe destruction of nitrocellulose can be achieved by alkaline hydrolysis, which converts it to biodegradable products that can then be treated by conventional biological processes. The kinetics of the alkaline hydrolysis of munitions-grade nitrocellulose in sodium hydroxide solutions were investigated in completely mixed batch reactors. Experiments were conducted using solutions of alkaline strength ranging from 0.1 to 15% by mass and temperatures in the range of 30 to 90 degrees C. Regression analysis of the kinetic data revealed that alkaline hydrolysis of nitrocellulose is of the order 1.0 and 1.5 with respect to nitrocellulose and hydroxide concentration, respectively. The activation energy of the hydrolysis reaction was found to be 100.9 kJ/mol with a preexponential Arrhenius constant of 4.73 x 10(13). Nitrite and nitrate, in a 3:1 ratio, were the primary nitrogen species present in the posthydrolysis solution. The kinetic information is pertinent to the development and optimization of nitrocellulose chemical-biological treatment systems.

  6. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  7. ISSUES WITH ALKALINE TREATMENT OF SLUDGE

    EPA Science Inventory

    This presentation begins with a discussion of the use of lime and other alkaline materials from the very earliest times to the present for killing bacteria, viruses and parasites and for controlling odors in wastewaters and sludge. It answers the question "How did EPA arrive at i...

  8. Alkaline earth metal catalysts for asymmetric reactions.

    PubMed

    Kobayashi, Shū; Yamashita, Yasuhiro

    2011-01-18

    The group 2 alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba) are among the most common elements on Earth, abundant in both the sea and the Earth's crust. Although they are familiar in our daily lives, their application to organic synthesis has, so far, been limited. Some particularly useful properties of these elements include (i) low electronegativity, (ii) a stable oxidation state of +2, meaning that they can potentially form two covalent bonds with anions, and (iii) the ability to occupy a variety of coordination sites due to their large ionic radius. Furthermore, the alkaline earth metals, found between the group 1 and group 3 elements, show mild but significant Lewis acidity, which can be harnessed to control coordinative molecules via a Lewis acid-base interaction. Taken together, these characteristics make the metals Ca, Sr, and Ba very promising components of highly functionalized acid-base catalysts. In this Account, we describe the development of chiral alkaline earth metal catalysts for asymmetric carbon-carbon bond-forming reactions. Recently prepared chiral alkaline earth metal complexes have shown high diastereo- and enantioselectivities in fundamental and important chemical transformations. We chose chiral bisoxazoline (Box) derivatives bearing a methylene tether as a ligand for chiral modification. These molecules are very useful because they can covalently coordinate to alkaline earth metals in a bidentate fashion through deprotonation of the tether portion. It was found that chiral calcium-Box complexes could successfully promote catalytic asymmetric 1,4-addition and [3 + 2] cycloaddition reactions with high diastereo- and enantioselectivities. Both the calcium-Box complexes and chiral strontium-bis-sulfonamide and chiral barium-BINOLate complexes could catalyze asymmetric 1,4-addition reactions with high enantioselectivities. Furthermore, we designed a calcium-neutral coordinative ligand complex as a new type of chiral alkaline

  9. Sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure.

    PubMed

    Coleman, Heather D; Yan, Jimmy; Mansfield, Shawn D

    2009-08-04

    Overexpression of the Gossypium hirsutum sucrose synthase (SuSy) gene under the control of 2 promoters was examined in hybrid poplar (Populus alba x grandidentata). Analysis of RNA transcript abundance, enzyme activity, cell wall composition, and soluble carbohydrates revealed significant changes in the transgenic lines. All lines showed significantly increased SuSy enzyme activity in developing xylem. This activity manifested in altered secondary cell wall cellulose content per dry weight in all lines, with increases of 2% to 6% over control levels, without influencing plant growth. The elevated concentration of cellulose was associated with an increase in cell wall crystallinity but did not alter secondary wall microfibril angle. This finding suggests that the observed increase in crystallinity is a function of altered carbon partitioning to cellulose biosynthesis rather than the result of tension wood formation. Furthermore, the augmented deposition of cellulose in the transgenic lines resulted in thicker xylem secondary cell wall and consequently improved wood density. These findings clearly implicate SuSy as a key regulator of sink strength in poplar trees and demonstrate the tight association of SuSy with cellulose synthesis and secondary wall formation.

  10. Children's food intake following drinks sweetened with sucrose or aspartame: time course effects.

    PubMed

    Birch, L L; McPhee, L; Sullivan, S

    1989-02-01

    In two experiments, 2-5-year-old children's responsiveness to caloric density cues was examined. In a preloading protocol, consumption of fixed volumes of drinks (205 ml in Experiment 1; 150 ml in Experiment 2), sweetened with sucrose, aspartame, aspartame plus low glucose maltodextrin, or a water control, was followed by ad lib consumption from among a variety of foods. Caloric drinks had about 90 kcal in Experiment 1, 65 kcal in Experiment 2. The delay interval between the preload and the ad lib consumption was 0, 30 or 60 minutes. In Experiment 1, 24 4- and 5-year-old children participated in only one delay interval, while in Experiment 2, all 20 2- and 3-year-old children were seen in all conditions. Results revealed evidence of caloric compensation, but no evidence of preload x time delay interaction. In both experiments, aspartame also produced a significant suppression of intake relative to water, primarily due to the pattern at 30 min following the preload. Across conditions, the suppression following aspartame was usually significantly less than that produced by the caloric sweet drinks, providing evidence for postingestive effects. In Experiment 1, suppression of intake was related to the children's preferences for the foods, not to macronutrient content; consumption of nonpreferred foods was most suppressed. Consumption of sweetened drinks as long as 1 hour prior to eating suppressed food intake, and this common feeding practice may also reduce dietary variety.

  11. A minipig model of high-fat/high-sucrose diet-induced diabetes and atherosclerosis

    PubMed Central

    Xi, Shoumin; Yin, Weidong; Wang, Zongbao; Kusunoki, Masataka; Lian, Xin; Koike, Tomonari; Fan, Jianglin; Zhang, Qiuju

    2004-01-01

    Type 2 diabetes is a major risk factor of the development of atherosclerosis in humans. However, studies examining mechanisms underlying diabetes-accelerated atherosclerosis have been limited by the lack of suitable humanoid animal models. Pigs have a cardiovascular system that is very similar to that of humans and is useful as a model for human physiology and pathophysiology. In this study, we established a new miniature pig model for studying dyslipidaemia and atherosclerosis in diabetes. Chinese Guizhou minipigs were fed a normal control diet or a high-fat/high-sucrose diet (HFSD) for 6 months. Plasma total cholesterol (TC), high-density lipoprotein cholesterol, triglyceride (TG), insulin and glucose were quantified at monthly intervals. The induction of insulin resistance and dysfunction of the pancreatic β-cell were assessed by oral glucose tolerance test and insulin sensitivity test. The aortic fatty streak lesions were quantified following lipid staining with Sudan IV. During the feeding period, mild high plasma TC and TG were induced. At the end of 6 months, in HFSD-fed animals, the adipocytes were hypertrophic, fat deposit in the liver was observed, loss of pancreatic β-cells was observed, and the aortic fatty streak lesions were clearly present in the animals' aortas. Our study established that miniature pigs that were fed a HFSD without adding dietary cholesterol developed insulin resistance, mild diabetes and atherosclerotic lesions. HFSD-fed miniature pigs may be good animal models for research on the treatment of diabetic dyslipidaemia complicated with atherosclerosis. PMID:15312127

  12. β₂ adrenergic receptor activation suppresses bone morphogenetic protein (BMP)-induced alkaline phosphatase expression in osteoblast-like MC3T3E1 cells.

    PubMed

    Yamada, Takayuki; Ezura, Yoichi; Hayata, Tadayoshi; Moriya, Shuichi; Shirakawa, Jumpei; Notomi, Takuya; Arayal, Smriti; Kawasaki, Makiri; Izu, Yayoi; Harada, Kiyoshi; Noda, Masaki

    2015-06-01

    β adrenergic stimulation suppresses bone formation in vivo while its actions in osteoblastic differentiation are still incompletely understood. We therefore examined the effects of β2 adrenergic stimulation on osteoblast-like MC3T3-E1 cells focusing on BMP-induced alkaline phosphatase expression. Morphologically, isoproterenol treatment suppresses BMP-induced increase in the numbers of alkaline phosphatase-positive small foci in the cultures of MC3T3-E1 cells. Biochemically, isoproterenol treatment suppresses BMP-induced enzymatic activity of alkaline phosphatase in a dose-dependent manner. Isoproterenol suppression of alkaline phosphatase activity is observed even when the cells are treated with high concentrations of BMP. With respect to cell density, isoproterenol treatment tends to suppress BMP-induced increase in alkaline phosphatase expression more in osteoblasts cultured at higher cell density. In terms of treatment protocol, continuous isoproterenol treatment is compared to cyclic treatment. Continuous isoproterenol treatment is more suppressive against BMP-induced increase in alkaline phosphatase expression than cyclic regimen. At molecular level, isoproterenol treatment suppresses BMP-induced enhancement of alkaline phosphatase mRNA expression. Regarding the mode of isoproterenol action, isoproterenol suppresses BMP-induced BRE-luciferase activity. These data indicate that isoproterenol regulates BMP-induced alkaline phosphatase expression in osteoblast-like MC3T3E1 cells.

  13. Effect of repeated doses of sucrose during heel stick procedure in preterm neonates.

    PubMed

    Johnston, C C; Stremler, R; Horton, L; Friedman, A

    1999-03-01

    The purpose of this randomized clinical trial was to test the efficacy of repeated versus single dose sucrose to decrease pain from routine heel stick procedures in preterm neonates. Infants (n = 48) in the first week of life with a mean gestational age of 31 weeks received 0.05 ml of 24% sucrose solution or sterile water by mouth (1) 2 min prior to actual lancing of the heel; (2) just prior to lancing, and (3) 2 min after lancing. The single-dose group received sucrose for the first dose and water for the second and third dose; the repeated-dose group received sucrose three times, and the placebo group received only water. The Premature Infant Pain Profile (PIPP) scores were obtained for five 30-second blocks from lancing. Both sucrose groups had lower PIPP scores (single sucrose pain scores, 6.8-8.2, p = 0.07; repeated sucrose pain scores, 5.3-6. 2, p < 0.01) than water (pain scores 7.9-9.1), and in the last block, the repeated dose had lower scores than the single dose (6.2 vs. 8. 2, p < 0.05).

  14. A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes

    PubMed Central

    Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L.; Huang, Chun-Ming

    2016-01-01

    Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne. PMID:27834859

  15. Molecular and functional characterization of a unique sucrose hydrolase from Xanthomonas axonopodis pv. glycines.

    PubMed

    Kim, Hong-Suk; Park, Hyoung-Joon; Heu, Sunggi; Jung, Jin

    2004-01-01

    A novel sucrose hydrolase (SUH) from Xanthomonas axonopodis pv. glycines, a causative agent of bacterial pustule disease on soybeans, was studied at the functional and molecular levels. SUH was shown to act rather specifically on sucrose (K(m) = 2.5 mM) but not on sucrose-6-phosphate. Protein analysis of purified SUH revealed that, in this monomeric enzyme with an estimated molecular mass of 70,223 +/- 12 Da, amino acid sequences determined for several segments have corresponding nucleotide sequences in XAC3490, a protein-coding gene found in the genome of X. axonopodis pv. citri. Based on this information, the SUH gene, consisting of an open reading frame of 1,935 bp, was cloned by screening a genomic library of X. axonopodis pv. glycines 8ra. Database searches and sequence comparison revealed that SUH has significant homology to some family 13 enzymes, with all of the crucial invariant residues involved in the catalytic mechanism conserved, but it shows no similarity to known invertases belonging to family 32. suh expression in X. axonopodis pv. glycines requires sucrose induction, and insertional mutagenesis resulted in an absence of sucrose-inducible sucrose hydrolase activity in crude protein extracts and a sucrose-negative phenotype. Recombinant SUH, overproduced in Escherichia coli and purified, was shown to have the same enzymatic characteristics in terms of kinetic parameters.

  16. Distinct sucrose isomerases catalyze trehalulose synthesis in whiteflies, Bemisia argentifolii, and Erwinia rhapontici.

    PubMed

    Salvucci, Michael E

    2003-06-01

    Isomaltulose [alpha-D-glucopyranosyl-(1,6)-D-fructofuranose] and trehalulose [alpha-D-glucopyranosyl-(1,1)-D-fructofuranose] are commercially valuable sucrose-substitutes that are produced in several microorganisms by the palI gene product, a sucrose isomerase. Trehalulose also occurs in the silverleaf whitefly, Bemisia argentifoli, as the major carbohydrate in the insect's honeydew. To determine if the enzyme that synthesizes trehalulose in whiteflies was similar to the well-characterized sucrose isomerase from microbial sources, the properties of the enzymes from whiteflies and the bacterium, Erwinia rhapontici, were compared. Partial purification of both enzymes showed that the enzyme from whiteflies was a 116 kD membrane-associated polypeptide, in contrast to the enzyme from E. rhapontici, which was soluble and 66 kD. The enzyme from E. rhapontici converted sucrose to isomaltulose and trehalulose in a 5:1 ratio, whereas the enzyme from whiteflies produced only trehalulose. Unlike the E. rhapontici enzyme, the whitefly enzyme did not convert isomaltulose to trehalulose, but both enzymes catalyzed the transfer of fructose to trehalulose using sucrose as the glucosyl donor. The results indicate that trehalulose synthase from whiteflies is structurally and functionally distinct from the sucrose isomerases described in bacteria. The whitefly enzyme is the first reported case of an enzyme that converts sucrose to exclusively trehalulose.

  17. A Precision Microbiome Approach Using Sucrose for Selective Augmentation of Staphylococcus epidermidis Fermentation against Propionibacterium acnes.

    PubMed

    Wang, Yanhan; Kao, Ming-Shan; Yu, Jinghua; Huang, Stephen; Marito, Shinta; Gallo, Richard L; Huang, Chun-Ming

    2016-11-09

    Acne dysbiosis happens when there is a microbial imbalance of the over-growth of Propionibacterium acnes (P. acnes) in the acne microbiome. In our previous study, we demonstrated that Staphylococcus epidermidis (S. epidermidis, a probiotic skin bacterium) can exploit glycerol fermentation to produce short-chain fatty acids (SCFAs) which have antimicrobial activities to suppress the growth of P. acnes. Unlike glycerol, sucrose is chosen here as a selective fermentation initiator (SFI) that can specifically intensify the fermentation activity of S. epidermidis, but not P. acnes. A co-culture of P. acnes and fermenting S. epidermidis in the presence of sucrose significantly led to a reduction in the growth of P. acnes. The reduction was abolished when P. acnes was co-cultured with non-fermenting S. epidermidis. Results from nuclear magnetic resonance (NMR) analysis revealed four SCFAs (acetic acid, butyric acid, lactic acid, and succinic acid) were detectable in the media of S. epidermidis sucrose fermentation. To validate the interference of S. epidermidis sucrose fermentation with P. acnes, mouse ears were injected with both P. acnes and S. epidermidis plus sucrose or phosphate buffered saline (PBS). The level of macrophage-inflammatory protein-2 (MIP-2) and the number of P. acnes in ears injected with two bacteria plus sucrose were considerably lower than those in ears injected with two bacteria plus PBS. Our results demonstrate a precision microbiome approach by using sucrose as a SFI for S. epidermidis, holding future potential as a novel modality to equilibrate dysbiotic acne.

  18. Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm - caries model.

    PubMed

    Botelho, Juliana Nunes; Villegas-Salinas, Mario; Troncoso-Gajardo, Pía; Giacaman, Rodrigo Andrés; Cury, Jaime Aparecido

    2016-05-20

    Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day) to one of the following treatments: 0.9% NaCl (negative control), 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose). To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day) the culture medium pH. After 4 (dentine) or 5 (enamel) days of growth, biofilms (n = 9) were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001) on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

  19. Mycorrhizas alter sucrose and proline metabolism in trifoliate orange exposed to drought stress

    PubMed Central

    Wu, Hui-Hui; Zou, Ying-Ning; Rahman, Mohammed Mahabubur; Ni, Qiu-Dan; Wu, Qiang-Sheng

    2017-01-01

    Arbuscular mycorrhizal fungi (AMF) can enhance drought tolerance in plants, whereas little is known regarding AMF contribution to sucrose and proline metabolisms under drought stress (DS). In this study, Funneliformis mosseae and Paraglomus occultum were inoculated into trifoliate orange (Poncirus trifoliata) under well watered and DS. Although the 71-days DS notably (P < 0.05) inhibited mycorrhizal colonization, AMF seedlings showed significantly (P < 0.05) higher plant growth performance and leaf relative water content, regardless of soil water status. AMF inoculation significantly (P < 0.05) increased leaf sucrose, glucose and fructose concentration under DS, accompanied with a significant increase of leaf sucrose phosphate synthase, neutral invertase, and net activity of sucrose-metabolized enzymes and a decrease in leaf acid invertase and sucrose synthase activity. AMF inoculation produced no change in leaf ornithine-δ-aminotransferase activity, but significantly (P < 0.05) increased leaf proline dehydrogenase activity and significantly (P < 0.05) decreased leaf both Δ1-pyrroline-5-carboxylate reductase and Δ1-pyrroline-5-carboxylate synthetase activity, resulting in lower proline accumulation in AMF plants under DS. Our results therefore suggest that AMF strongly altered leaf sucrose and proline metabolism through regulating sucrose- and proline-metabolized enzyme activities, which is important for osmotic adjustment of the host plant. PMID:28181575

  20. Are sucrose transporter expression profiles linked with patterns of biomass partitioning in Sorghum phenotypes?

    PubMed Central

    Milne, Ricky J.; Byrt, Caitlin S.; Patrick, John W.; Grof, Christopher P. L.

    2013-01-01

    Sorghum bicolor is a genetically diverse C4 monocotyledonous species, encompassing varieties capable of producing high grain yields as well as sweet types which accumulate soluble sugars (predominantly sucrose) within their stems to high concentrations. Sucrose produced in leaves (sources) enters the phloem and is transported to regions of growth and storage (sinks). It is likely that sucrose transporter (SUT) proteins play pivotal roles in phloem loading and the delivery of sucrose to growth and storage sinks in all Sorghum ecotypes. Six SUTs are present in the published Sorghum genome, based on the BTx623 grain cultivar. Homologues of these SUTs were cloned and sequenced from the sweet cultivar Rio, and compared with the publically available genome information. SbSUT5 possessed nine amino acid sequence differences between the two varieties. Two of the remaining five SUTs exhibited single variations in their amino acid sequences (SbSUT1 and SbSUT2) whilst the rest shared identical sequences. Complementation of a mutant Saccharomyces yeast strain (SEY6210), unable to grow upon sucrose as the sole carbon source, demonstrated that the Sorghum SUTs were capable of transporting sucrose. SbSUT1, SbSUT4, and SbSUT6 were highly expressed in mature leaf tissues and hence may contribute to phloem loading. In contrast, SbSUT2 and SbSUT5 were expressed most strongly in sinks consistent with a possible role of facilitating sucrose import into stem storage pools and developing inflorescences. PMID:23805151

  1. Are sucrose transporter expression profiles linked with patterns of biomass partitioning in Sorghum phenotypes?

    PubMed

    Milne, Ricky J; Byrt, Caitlin S; Patrick, John W; Grof, Christopher P L

    2013-01-01

    Sorghum bicolor is a genetically diverse C4 monocotyledonous species, encompassing varieties capable of producing high grain yields as well as sweet types which accumulate soluble sugars (predominantly sucrose) within their stems to high concentrations. Sucrose produced in leaves (sources) enters the phloem and is transported to regions of growth and storage (sinks). It is likely that sucrose transporter (SUT) proteins play pivotal roles in phloem loading and the delivery of sucrose to growth and storage sinks in all Sorghum ecotypes. Six SUTs are present in the published Sorghum genome, based on the BTx623 grain cultivar. Homologues of these SUTs were cloned and sequenced from the sweet cultivar Rio, and compared with the publically available genome information. SbSUT5 possessed nine amino acid sequence differences between the two varieties. Two of the remaining five SUTs exhibited single variations in their amino acid sequences (SbSUT1 and SbSUT2) whilst the rest shared identical sequences. Complementation of a mutant Saccharomyces yeast strain (SEY6210), unable to grow upon sucrose as the sole carbon source, demonstrated that the Sorghum SUTs were capable of transporting sucrose. SbSUT1, SbSUT4, and SbSUT6 were highly expressed in mature leaf tissues and hence may contribute to phloem loading. In contrast, SbSUT2 and SbSUT5 were expressed most strongly in sinks consistent with a possible role of facilitating sucrose import into stem storage pools and developing inflorescences.

  2. Maltodextrin can produce similar metabolic and cognitive effects to those of sucrose in the rat.

    PubMed

    Kendig, Michael D; Lin, Candy S; Beilharz, Jessica E; Rooney, Kieron B; Boakes, Robert A

    2014-06-01

    In the context of the well-documented metabolic and behavioural effects of supplementing rats' diets with access to a sucrose solution, the aim of this study was to compare the impact of 10% sucrose with that of an isoenergetic (10.4%) solution of hydrolysed starch, maltodextrin. This polysaccharide is metabolised at least as rapidly as sucrose and is also very palatable to rats, but does not contain fructose. Each of three experiments contained three groups: one given a sucrose solution, one given a maltodextrin solution and a control group maintained on standard chow and water alone. In Experiment 1 the sucrose and maltodextrin groups were given their supplementary drinks for 2 h each day, while in Experiments 2 and 3 these groups had 24-h access to their supplements. Ad libitum access to maltodextrin produced at least as rapid weight gain as sucrose and in Experiment 2 retroperitoneal fat mass was greater in the two carbohydrate groups than in the control group. Moreover, in Experiment 3, impaired performance on a location recognition task was also found in both carbohydrate groups after only 17 days on the diets. These results indicate that the harmful effects of excess sucrose consumption can also be produced by another rapidly absorbed carbohydrate that does not contain fructose.

  3. Differential motivational profiles following adolescent sucrose access in male and female rats.

    PubMed

    Reichelt, Amy C; Abbott, Kirsten N; Westbrook, R Fred; Morris, Margaret J

    2016-04-01

    Adolescents are the highest consumers of sugar sweetened drinks. Excessive consumption of such drinks is a likely contributor to the development of obesity and may be associated with enduring changes in the systems involved in reward and motivation. We examined the impact of daily sucrose consumption in young male and female rats (N=12 per group) across the adolescent period on the motivation to perform instrumental responses to gain food rewards as adults. Rats were or were not exposed to a sucrose solution for 2 h each day for 28 days across adolescence [postnatal days (P) 28-56]. They were then trained as adults (P70 onward) to lever press for a palatable 15% cherry flavored sucrose reward and tested on a progressive ratio (PR) schedule to assess motivation to respond for reinforcement. Female rats exposed to sucrose had higher breakpoints on the PR schedule than controls, whereas male rats exposed to sucrose had lower breakpoints than controls. These results show that consumption of sucrose during adolescence produced sex-specific behavioral changes in responding for sucrose as adults.

  4. Measuring the Density of a Sugar Solution: A General Chemistry Experiment Using a Student-Prepared Unknown

    ERIC Educational Resources Information Center

    Peterson, Karen I.

    2008-01-01

    The experiment developed in this article addresses the concept of equipment calibration for reducing systematic error. It also suggests simple student-prepared sucrose solutions for which accurate densities are known, but not readily available to students. Densities are measured with simple glassware that has been calibrated using the density of…

  5. Alkaline regenerative fuel cell systems for energy storage

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Reid, M. A.; Martin, R. E.

    1981-01-01

    A description is presented of the results of a preliminary design study of a regenerative fuel cell energy storage system for application to future low-earth orbit space missions. The high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. In addition to providing energy storage, the system can provide hydrogen and oxygen for attitude control of the satellite and for life support. During the daylight portion of the orbit the electrolysis module uses power provided by the solar array to generate H2 and O2 from the product water produced by the fuel cell module. The fuel cell module supplies electrical power during the dark period of the orbit.

  6. Solid-State Water Electrolysis with an Alkaline Membrane

    SciTech Connect

    Leng, YJ; Chen, G; Mendoza, AJ; Tighe, TB; Hickner, MA; Wang, CY

    2012-06-06

    We report high-performance, durable alkaline membrane water electrolysis in a solid-state cell. An anion exchange membrane (AEM) and catalyst layer ionomer for hydroxide ion conduction were used without the addition of liquid electrolyte. At 50 degrees C, an AEM electrolysis cell using iridium oxide as the anode catalyst and Pt black as the cathode catalyst exhibited a current density of 399 mA/cm(2) at 1.80 V. We found that the durability of the AEM-based electrolysis cell could be improved by incorporating a highly durable ionomer in the catalyst layer and optimizing the water feed configuration. We demonstrated an AEM-based electrolysis cell with a lifetime of > 535 h. These first-time results of water electrolysis in a solid-state membrane cell are promising for low-cost, scalable hydrogen production.

  7. Crystal structure of alkaline cellulase K: insight into the alkaline adaptation of an industrial enzyme.

    PubMed

    Shirai, T; Ishida, H; Noda, J; Yamane, T; Ozaki, K; Hakamada, Y; Ito, S

    2001-07-27

    The crystal structure of the catalytic domain of alkaline cellulase K was determined at 1.9 A resolution. Because of the most alkaliphilic nature and it's highest activity at pH 9.5, it is used commercially in laundry detergents. An analysis of the structural bases of the alkaliphilic character of the enzyme suggested a mechanism similar to that previously proposed for alkaline proteases, that is, an increase in the number of Arg, His, and Gln residues, and a decrease in Asp and Lys residues. Some ion pairs were formed by the gained Arg residues, which is similar to what has been found in the alkaline proteases. Lys-Asp ion pairs are disfavored and partly replaced with Arg-Asp ion pairs. The alkaline adaptation appeared to be a remodeling of ion pairs so that the charge balance is kept in the high pH range.

  8. Downregulating the sucrose transporter VpSUT1 in Verbascum phoeniceum does not inhibit phloem loading

    PubMed Central

    Zhang, Cankui; Turgeon, Robert

    2009-01-01

    Sucrose is loaded into the phloem in the minor veins of leaves before export. Two active, species-specific loading mechanisms have been proposed. One involves transporter-mediated sucrose transfer from the apoplast into the sieve element-companion cell complex, so-called apoplastic loading. In the putative second mechanism, sucrose follows an entirely symplastic pathway, and the solute concentration is elevated by the synthesis of raffinose and stachyose in the phloem, not by transporter activity. Several sucrose-transporting plants have been shown to be apoplastic loaders by downregulating sucrose transporter 1 (SUT1), leading to accumulation of sugars and leaf chlorosis. In this study we compared the effect of downregulating SUT1 in Nicotiana tabacum, a sucrose transporter, and Verbascum phoeniceum, a species that transports raffinose and stachyose. To test the effectiveness of RNAi downregulation, we measured SUT1 mRNA levels and sucrose-H+ symport in leaf discs. Mild NtSUT1 downregulation in N. tabacum resulted in the pronounced phenotype associated with loading inhibition. In contrast, no such phenotype developed when VpSUT1 was downregulated in V. phoeniceum, leaving minimal sucrose transport activity. Only those plants with the most severe VpSUT1 downregulation accumulated more carbohydrate than usual and these plants were normal by other criteria: growth rate, photosynthesis, and ability to clear starch during the night. The results provide direct evidence that the mechanism of phloem loading in V. phoeniceum does not require active sucrose uptake from the apoplast and strongly supports the conclusion that the loading pathway is symplastic in this species. PMID:19846784

  9. Anhedonia in pigs? Effects of social stress and restraint stress on sucrose preference.

    PubMed

    Figueroa, Jaime; Solà-Oriol, David; Manteca, Xavier; Pérez, José Francisco; Dwyer, Dominic Michael

    2015-11-01

    The fact that consumption of normally palatable foods is affected by stress in both humans and rats suggests a means to assess hedonic reaction in non-verbal animals. However, little is known about anhedonia and stress in productive animals such as pigs. Thus we examined the separate effects of social stress and restraint stress in 42-day old pigs on the preference for dilute sucrose solutions over water. Pigs in the social stress group (SS) were mixed with unfamiliar animals from separate pens for two 20 minute periods (Experiment 1). Pigs in the restraint stress group (RS) were immobilized three times a day, for 3-min periods, on 3 consecutive days (Experiment 2). Consumption of dilute sucrose solutions and water was examined after these stress manipulations and in the unstressed control groups (CG). Pigs were tested in pairs (12 control and 12 experimental) with a choice between water and sucrose solutions (at either 0.5% or 1%) during 30 min sessions. In both experiments CG pigs showed higher intakes of 0.5% and 1% sucrose solutions over water. Neither SS nor RS pigs consumed more 0.5% sucrose than water, but both groups did consume more 1% sucrose than water. Both social stress and restraint stress reduced sucrose preference at low concentrations but not at higher concentrations suggesting that stress may limit food consumption in pigs unless a palatable feed is present. In addition, the results suggest that stress reduces the hedonic impact of dilute sucrose. Therefore, sucrose preference may be a useful test for the presence of stress and anhedonia in pigs.

  10. Sucrose-induced analgesia during early life modulates adulthood learning and memory formation.

    PubMed

    Nuseir, Khawla Q; Alzoubi, Karem H; Alabwaini, Jehad; Khabour, Omar F; Kassab, Manal I

    2015-06-01

    This study is aimed at examining the long-term effects of chronic pain during early life (postnatal day 0 to 8weeks), and intervention using sucrose, on cognitive functions during adulthood in rats. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution or paracetamol was administered for analgesia before the paw prick. Control groups include tactile stimulation to account for handling and touching the paws, and sucrose alone was used. All treatments were started on day one of birth and continued for 8weeks. At the end of the treatments, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM), as well as pain threshold via foot-withdrawal response to a hot plate apparatus. Additionally, the hippocampus was dissected, and blood was collected. Levels of neurotrophins (BDNF, IGF-1 and NT-3) and endorphins were assessed using ELISA. The results show that chronic noxious stimulation resulted in comparable foot-withdrawal latency between noxious and tactile groups. On the other hand, pretreatment with sucrose or paracetamol increased pain threshold significantly both in naive rats and noxiously stimulated rats (P<0.05). Chronic pain during early life impaired short-term memory, and sucrose treatment prevented such impairment (P<0.05). Sucrose significantly increased serum levels of endorphin and enkephalin. Chronic pain decreased levels of BDNF in the hippocampus and this decrease was prevented by sucrose and paracetamol treatments. Hippocampal levels of NT-3 and IGF-1 were not affected by any treatment. In conclusion, chronic pain induction during early life induced short memory impairment, and pretreatment with sucrose prevented this impairment via mechanisms that seem to involve BDNF. As evident in the results, sucrose, whether alone or in the presence of pre-noxious stimulation, increases pain threshold in such circumstances; most likely via a mechanism that involves an increase in endogenous

  11. A Rat Drinking in the Dark Model for Studying Ethanol and Sucrose Consumption

    PubMed Central

    Holgate, Joan Y.; Shariff, Masroor; Mu, Erica W. H.; Bartlett, Selena

    2017-01-01

    Background: The intermittent access 2-bottle choice (IA2BC) and drinking in the dark (DID) models were developed for studying rodent binge-like consumption. Traditionally, IA2BC was used with rats and DID with mice. Recently, IA2BC was adapted to study mouse ethanol consumption. However, it is unknown whether DID is suitable for rats or if one rat model is more advantageous than another for studying binge-like consumption. Methods: Male Wistar rats consumed 20% ethanol or 5% sucrose using IA2BC or DID for 12 weeks. IA2BC drinking sessions occurred on alternate days (Mondays–Fridays) and lasted 24 h, whereas DID sessions ran 4 h/day, 5 days/week (Monday–Friday). Average consumption/session, week and hour was measured. To explore DID model suitability for screening novel compounds for controlling ethanol and sucrose intake, varenicline (2 mg/kg) or vehicle was administered to DID rats. Results: IA2BC rats consume more ethanol/session and similar amounts of ethanol/week than DID rats. While, IA2BC rats consume more sucrose/session and week than DID rats. Although IA2BC rats had more ethanol and sucrose access time, DID rats had greater ethanol and sucrose intake/hour. Varenicline significantly reduced ethanol and sucrose consumption in DID rats, consistent with previously published IA2BC studies. Conclusions: Despite the shorter access time, the rat DID model induced higher initial intake and greater consumption/hour for both ethanol and sucrose. The shorter duration of DID sessions did not prevent detection of varenicline-induced reductions in ethanol or sucrose consumption, suggesting the DID model may be suitable for studying binge-like ethanol and sucrose consumption. PMID:28275340

  12. Transcriptional coordination and abscisic acid mediated regulation of sucrose transport and sucrose-to-starch metabolism related genes during grain filling in wheat (Triticum aestivum L.).

    PubMed

    Mukherjee, Shalini; Liu, Aihua; Deol, Kirandeep K; Kulichikhin, Konstanin; Stasolla, Claudio; Brûlé-Babel, Anita; Ayele, Belay T

    2015-11-01

    Combining physiological, molecular and biochemical approaches, this study investigated the transcriptional coordination and abscisic acid (ABA) mediated regulation of genes involved in sucrose import and its conversion to starch during grain filling in wheat. Sucrose import appears to be mediated by seed localized TaSUT1, mainly TaSUT1D, while sucrose cleavage by TaSuSy2. Temporal overlapping of the transcriptional activation of AGPL1 and AGPS1a that encode AGPase with that of the above genes suggests their significance in the synthesis of ADP-glucose; TaAGPL1A and TaAGPL1D contributing the majority of AGPL1 transcripts. ABA induced repressions of TaSUT1, TaSuSy2, TaAGPL1 and TaAGPS1a imply that ABA negatively regulates sucrose import into the endosperm and its subsequent metabolism to ADP-glucose, the substrate for starch synthesis. The formations of amyloses and amylopectin from ADP-glucose appear to be mediated by specific members of GBSS, and SS, SBE and DBE gene families, and the ABA-induced transcriptional change in most of these genes implies that ABA regulates amylose and amylopectin synthesis. The findings provide insights into the molecular mechanisms underlying the coordination and ABA mediated regulation of sucrose transport into the developing endosperm and its subsequent metabolism to starch during grain filling in wheat.

  13. Direct use of alcohols and sodium borohydride as fuel in an alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Verma, A.; Basu, S.

    The performance of an alkaline fuel cell (AFC) was studied at different electrolyte concentrations and temperatures for the direct feeding of methanol, ethanol and sodium borohydride as fuels. Potassium hydroxide is used as the electrolyte in the alkaline fuel cell. The anode was prepared by using Pt black, carbon paper and Nafion dispersion. Nickel mesh was used as the current collector. A standard cathode made of manganese dioxide/carbon paper/Ni-mesh/Teflon dispersion (Electro-Chem-Technic, UK) was used for testing the fuel cell performance. The experimental results showed that the current density increases with increase in KOH concentration. Maximum current densities of 300, 270 and 360 A m -2 were obtained for methanol, ethanol and sodium borohydride as fuel respectively with 3 M KOH electrolyte at 25 °C. The cell performance decreases with further increase in the KOH concentration. The current density of the alkaline fuel cell increases with increase in temperature for all the three fuels. The increase in current density with temperature is not as high as expected for sodium borohydride. These results are explained based on an electrochemical phenomenon and different associated losses.

  14. Influence of phosphate-buffered sucrose solution on early graft function in feline renal autotransplantation.

    PubMed

    Katayama, Masaaki; Okamura, Yasuhiko; Shimamura, Shunsuke; Katayama, Rieko; Kamishina, Hiroaki; Uzuka, Yuji

    2014-10-01

    Graft perfusion with cold heparinized saline has known to induce ischemia and reperfusion injury in feline kidney transplantation. In this study, the effects of phosphate-buffered sucrose solution and heparinized saline solution on early kidney graft function were compared in feline kidney autotransplantation. Perfusion of grafts with or without hypothermic storage with chilled phosphate-buffered sucrose solution prevented ischemia and reperfusion injury despite a very short ischemic time. The results of our study suggest that phosphate-buffered sucrose perfusion and storage solution should be effective to reduce ischemia and reperfusion injury despite a very short ischemic time in feline kidney transplantation.

  15. Amygdala response to sucrose consumption is inversely related to artificial sweetener use.

    PubMed

    Rudenga, K J; Small, D M

    2012-04-01

    Controversy exists over whether exposure to artificial sweeteners degrades the predictive relationship between sweet taste and its post-ingestive consequences. Here we tested whether brain response to caloric sucrose is influenced by individual differences in self-reported artificial sweetener use. Twenty-six subjects participated in fMRI scanning while consuming sucrose solutions. A negative correlation between artificial sweetener use and amygdala response to sucrose ingestion was observed. This finding supports the hypothesis that artificial sweetener use may be associated with brain changes that could influence eating behavior.

  16. Amygdala response to sucrose consumption is inversely related to artificial sweetener use

    PubMed Central

    Rudenga, KJ; Small, DM

    2011-01-01

    Controversy exists over whether exposure to artificial sweeteners degrades the predictive relationship between sweet taste and its post-ingestive consequences. Here we tested whether brain response to caloric sucrose is influenced by individual differences in self-reported artificial sweetener use. Twenty-six subjects participated in fMRI scanning while consuming sucrose solutions. A negative correlation between artificial sweetener use and amygdala response to sucrose ingestion was observed. This finding supports the hypothesis that artificial sweetener use may be associated with brain changes that could influence eating behavior. PMID:22178008

  17. The Spatial Distribution of Sucrose Synthase Isozymes in Barley.

    PubMed Central

    Guerin, J.; Carbonero, P.

    1997-01-01

    The sucrose (Suc) synthase enzyme purified from barley (Hordeum vulgare L.) roots is a homotetramer that is composed of 90-kD type 1 Suc synthase (SS1) subunits. Km values for Suc and UDP were 30 mM and 5 [mu]M, respectively. This enzyme can also utilize ADP at 25% of the UDP rate. Anti-SS1 polyclonal antibodies, which recognized both SS1 and type 2 Suc synthase (SS2) (88-kD) subunits, and antibodies raised against a synthetic peptide, LANGSTDNNFV, which were specific for SS2, were used to study the spatial distribution of these subunits by immunoblot analysis and immunolocalization. Both SS1 and SS2 were abundantly expressed in endosperm, where they polymerize to form the five possible homo- and heterotetramers. Only SS1 homotetramers were detected in young leaves, where they appeared exclusively in phloem cells, and in roots, where expression was associated with cap cells and the vascular bundle. In the seed both SS1 and SS2 were present in endosperm, but only SS1 was apparent in the chalazal region, the nucellar projection, and the vascular bundle. The physiological implications for the difference in expression patterns observed are discussed with respect to the maize (Zea mays L.) model. PMID:12223688

  18. Aspen SUCROSE TRANSPORTER3 allocates carbon into wood fibers.

    PubMed

    Mahboubi, Amir; Ratke, Christine; Gorzsás, András; Kumar, Manoj; Mellerowicz, Ewa J; Niittylä, Totte

    2013-12-01

    Wood formation in trees requires carbon import from the photosynthetic tissues. In several tree species, including Populus species, the majority of this carbon is derived from sucrose (Suc) transported in the phloem. The mechanism of radial Suc transport from phloem to developing wood is not well understood. We investigated the role of active Suc transport during secondary cell wall formation in hybrid aspen (Populus tremula × Populus tremuloides). We show that RNA interference-mediated reduction of PttSUT3 (for Suc/H(+) symporter) during secondary cell wall formation in developing wood caused thinner wood fiber walls accompanied by a reduction in cellulose and an increase in lignin. Suc content in the phloem and developing wood was not significantly changed. However, after (13)CO2 assimilation, the SUT3RNAi lines contained more (13)C than the wild type in the Suc-containing extract of developing wood. Hence, Suc was transported into developing wood, but the Suc-derived carbon was not efficiently incorporated to wood fiber walls. A yellow fluorescent protein:PttSUT3 fusion localized to plasma membrane, suggesting that reduced Suc import into developing wood fibers was the cause of the observed cell wall phenotype. The results show the importance of active Suc transport for wood formation in a symplasmically phloem-loading tree species and identify PttSUT3 as a principal transporter for carbon delivery into secondary cell wall-forming wood fibers.

  19. Carbon Partitioning during Sucrose Accumulation in Sugarcane Internodal Tissue.

    PubMed

    Whittaker, A.; Botha, F. C.

    1997-12-01

    The temporal relationship between sucrose (Suc) accumulation and carbon partitioning was investigated in developing sugarcane internodes. Radiolabeling studies on tissue slices, which contained Suc concentrations ranging from 14 to 42% of the dry mass, indicated that maturation coincided with a redirection of carbon from water-insoluble matter, respiration, amino acids, organic acids, and phosphorylated intermediates into Suc. It is evident that a cycle of Suc synthesis and degradation exists in all of the internodes. The decreased allocation of carbon to respiration coincides with a decreased flux from the hexose pool. Both the glucose and fructose (Fru) concentrations significantly decrease during maturation. The phosphoenolpyruvate, Fru-6-phosphate (Fru-6-P), and Fru-2,6-bisphosphate (Fru-2, 6-P2) concentrations decrease between the young and older internodal tissue, whereas the inorganic phosphate concentration increases. The calculated mass-action ratios indicate that the ATP-dependent phosphofructokinase, pyruvate kinase, and Fru-1,6-bisphosphatase reactions are tightly regulated in all of the internodes, and no evidence was found that major changes in the regulation of any of these enzymes occur. The pyrophosphate-dependent phosphofructokinase reaction is in apparent equilibrium in all the internodes. Substrate availability might be one of the prime factors contributing to the observed decrease in respiration.

  20. Multisite phosphorylation of spinach leaf sucrose-phosphate synthase

    SciTech Connect

    Huber, J.L.; Huber, S.C. )

    1990-05-01

    Spinach leaf sucrose-phosphate synthase is phosphorylated both in vivo and in vitro on serine residues. Phosphorylation of SPS in vivo yields twelve major phosphopeptides after a tryptic digest and two dimensional mapping. The in vivo labeling of three of these SPS P-peptides is reduced in illuminated leaves where the extracted enzyme is activated relative to that of dark leaves. Two of these inhibitory sites are phosphorylated as well when SPS is inactivated in vitro using ({sup 32}P)ATP. In vivo phosphorylation of two other sites is enhanced during mannose feeding of the leaves (in light or dark) which produces the highest activation state of SPS. Overall, the results confirm that light-dark regulation of SPS activity occurs as a result of regulatory seryl-phosphorylation and involves a balance between phosphorylation of sites which inhibit or stimulate activity. Regulation of the SPS protein kinase that inhibits activity is relatively unaffected by phosphate but inhibited by G1c 6-P (IC{sub 50}{approx}5 mM), which may explain the control of SPS activation state by light-dark signals.

  1. Characterization of the Highly Efficient Sucrose Isomerase from Pantoea dispersa UQ68J and Cloning of the Sucrose Isomerase Gene

    PubMed Central

    Wu, Luguang; Birch, Robert G.

    2005-01-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35°C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50°C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35°C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg−1, and the Kcat/Km was 1.79 × 104 M−1 s−1, compared to a Km of 76.0 mM, a Vmax of 423 U mg−1, and a Kcat/Km of 0.62 × 104 M−1 s−1 for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose. PMID:15746363

  2. Characterization of the highly efficient sucrose isomerase from Pantoea dispersa UQ68J and cloning of the sucrose isomerase gene.

    PubMed

    Wu, Luguang; Birch, Robert G

    2005-03-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35 degrees C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50 degrees C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35 degrees C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg(-1), and the Kcat/Km was 1.79 x 10(4) M(-1) s(-1), compared to a Km of 76.0 mM, a Vmax of 423 U mg(-1), and a Kcat/Km of 0.62 x 10(4) M(-1) s(-1) for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose.

  3. Drought induces fructan synthesis and 1-SST (sucrose:sucrose fructosyltransferase) in roots and leaves of chicory seedlings (Cichorium intybus L.).

    PubMed

    De Roover, J; Vandenbranden; Van Laere, A; Van den Ende, W

    2000-04-01

    Seeds of Cichorium intybus L. var. foliosum cv. Flash were sown in acid-washed vermiculite and grown in a controlled-environment growth chamber. After 1 month of growth, plantlets did not contain sucrose:sucrose 1-fructosyltransferase (1-SST), the key enzyme in fructan biosynthesis. No fructan could be observed. Some of the plants were submitted to drought for 2 weeks. Glucose, fructose and sucrose concentrations increased in roots and leaves of stressed plants and the fructan concentration in roots and leaves was ten times higher than in control plants. The onset of fructan synthesis coincided with the increase in 1-SST activity in roots. Expression of the 1-SST gene could be observed in roots and leaves of stressed plants.

  4. The sulphate-reduction alkalinity pump tested

    NASA Astrophysics Data System (ADS)

    Meister, Patrick; Petrishcheva, Elena

    2016-04-01

    Carbonate precipitation has been suggested to be induced by alkalinity increase during sulphate reduction under anoxic conditions. This mechanism may explain the formation of carbonate deposits in shallow marine environments, either within a redox stratified sediment inhabited by phototrophic microbial mats or in shallow water within the photic zone where sulphidic water is upwelling onto the shelf. The alkalinity pump may work as long as the sulphide is not reoxidized to sulphate, a process that would acidify the surrounding. The alkalinity effect of sulphate reduction was recently tested by Aloisi (2008) for microbial mats using a model approach. He found that sulphate reduction does not significantly increase or even decrease carbonate saturation and is unlikely to have played a significant role through Earth history. The model considers many environmental factors, including the effect of carbonate precipitation itself on the carbonate equilbrium and on the alkalinity. We used a modified version of Aloisi's (2008) model to simulate the saturation states of aragonite, calcite and dolomite without the effects of carbonate precipitation. This is necessary to evaluate the effect of microbial metabolisms exclusively on carbonate saturation, since carbonate precipitation is only the consequence, but not the cause of oversaturation. First results show that the saturation state is increased in the zone of phototrophic CO2 uptake. In contrast, the saturation state is strongly decreased in the zone where dissolved oxygen overlaps with dissolved sulphide. Aerobic sulphide oxidation consumes most of the HS- and dissipates most of the alkalinity produced in the sulphate reduction zone below. Hence, our results are consistent with the findings of Aloisi (2008), and they even more clearly show that sulphate reduction does not induce carbonate precipitation nor contributes to carbonate precipitation in combination with phototrophic CO2 uptake. The alkalinity effect of sulphate

  5. [Leucocyte alkaline phosphatase in normal and pathological pregnancy (author's transl)].

    PubMed

    Stark, K H; Zaki, I; Sobolewski, K

    1981-01-01

    The activities of leucocyte alkaline phosphatase were determined in 511 patients with normal and pathological pregnancy. Mean values were compared and the enzyme followed up, and the conclusion was drawn that leucocyte alkaline phosphatase was no safe indicator of foetal condition. No direct relationship were found to exist between leucocyte alkaline phosphatase, total oestrogens, HSAP, HLAP, HPL, and oxytocinase.

  6. Blue Maize Extract Improves Blood Pressure, Lipid Profiles, and Adipose Tissue in High-Sucrose Diet-Induced Metabolic Syndrome in Rats.

    PubMed

    Guzmán-Gerónimo, Rosa Isela; Alarcón-Zavaleta, Tania Margarita; Oliart-Ros, Rosa María; Meza-Alvarado, José Enrique; Herrera-Meza, Socorro; Chávez-Servia, José Luis

    2017-02-01

    The effect of blue maize extract in factors related to metabolic syndrome (MS) in Wistar rats was investigated. Total polyphenols, monomeric anthocyanins, and antioxidant activity were analyzed in blue maize. MS was induced in Wistar rats fed with high-sucrose (HS) diet for 12 weeks. During a period of 4 weeks, blue maize extract was administrated to HS groups fed with high-sucrose and high-cholesterol-high-sucrose (HS+C) diets. In the blue maize extract administered by orogastric cannulation, the levels of total polyphenols and anthocyanins were 9.97 and 2.92 mg/kg of weight, respectively. HS diet administered during a period of 12 weeks increased significantly systolic blood pressure, serum triglycerides, and decreased high-density lipoprotein cholesterol (HDL-C), alterations related to the MS. Abdominal adipose tissue was only increased in the HS + C group. Blue maize extract administration enhanced HDL-C and decreased systolic blood pressure, serum triglycerides, total cholesterol, and epididymal adipose tissue weight. The blue maize may represent a promising nutraceutical option for the treatment of MS.

  7. Sucrose-assisted loading of LiFePO4 nanoparticles on graphene for high-performance lithium-ion battery cathodes.

    PubMed

    Wu, Yongmin; Wen, Zhenhai; Feng, Hongbin; Li, Jinghong

    2013-04-26

    A simple approach for loading LiFePO4 (LFP) nanoparticles on graphene (G) that could assemble amorphous LiFePO4 nanoparticles into a stable, crystalline, graphene-modified layered materials (G-S-LFP, S=sucrose) by using graphene as building block and sucrose as a linker has yet to be developed. On the basis of differential scanning calorimetric and transmission electron microscopy analysis of the samples from controlled experiment, a possible mechanism was proposed to explain the "linker" process of LFP and graphene with sucrose as the linker. The electrochemical properties of the samples as cathode material for lithium-ion batteries were studied by cyclic voltammogrametry and galvanostatic methods. Results showed that G-S-LFP displayed superior lithium-storage capability with current density changes randomly form 0.5 to 10 C. The significant improvement for rate and cycle performance could be attributed to the high conductivity of the graphene host, the high crystallinity, and the layered structure.

  8. The effect of normally consumed amounts of sucrose or high fructose corn syrup on lipid profiles, body composition and related parameters in overweight/obese subjects.

    PubMed

    Lowndes, Joshua; Sinnett, Stephanie; Pardo, Sabrina; Nguyen, Von T; Melanson, Kathleen J; Yu, Zhiping; Lowther, Britte E; Rippe, James M

    2014-03-17

    The American Heart Association (AHA) has advocated that women and men not consume more than 100 and 150 kcal/day, respectively, from added sugars. These levels are currently exceeded by over 90% of the adult population in the United States. Few data exist on longer-term metabolic effects when sucrose and High Fructose Corn Syrup (HFCS), the principal sources of added dietary sugars, are consumed at levels typical of the general population. Sixty five overweight and obese individuals were placed on a eucaloric (weight stable) diet for 10-weeks, which incorporated sucrose- or HFCS-sweetened, low-fat milk at 10% or 20% of calories in a randomized, double-blinded study. All groups responded similarly (interaction p > 0.05). There was no change in body weight in any of the groups over the 10-week study, or in systolic or diastolic blood pressure. Likewise, there were no changes in total cholesterol, triglycerides, low-density lipoprotein (LDL), or apolipoprotein B (Apo B). We conclude that (1) when consumed as part of a eucaloric diet fructose--when given with glucose (as normally consumed) does not promote weight gain or an atherogenic lipid profile even when consumed at two to four times the level recently recommended by the AHA. (2) There were no differences between HFCS and sucrose on these parameters.

  9. Similarity of rpoB gene sequences of sucrose-fermenting and non-fermenting Corynebacterium diphtheriae strains.

    PubMed

    Hirata, R; Pacheco, L G; Soares, S C; Santos, L S; Moreira, L O; Sabbadini, P S; Santos, C S; Miyoshi, A; Azevedo, V A; Mattos-Guaraldi, A L

    2011-03-01

    During the last decades, the majority of Brazilian Corynebacterium diphtheriae isolates were shown to be capable to metabolize sucrose, sometimes leading to erroneous identification as a non-diphtheric Corynebacterium species. The sequencing of the polymorphic region of the RNA polymerase beta subunit-encoding gene (rpoB) is an important taxonomic tool for identification of corynebacteria. The present study aimed to investigate the rpoB gene polymorphic features of sucrose-fermenting and non sucrose-fermenting strains. The results showed that sucrose-fermenting strains presented rpoB gene polymorphic regions with more than 98% similarity with the sequences deposited in the gene bank corresponding to non sucrose-fermenting strains. Data indicate that sucrose-fermenting isolates may act as a variant of C. diphtheriae biotype mitis. In addition we alert that sucrose-fermenting strains should not be discarded as contaminants mainly in countries where the possibility of isolation of this variant is higher.

  10. The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

    NASA Astrophysics Data System (ADS)

    Whitney, Heather M.; Dyer, Adrian; Chittka, Lars; Rands, Sean A.; Glover, Beverley J.

    2008-09-01

    Several authors have found that flowers that are warmer than their surrounding environment have an advantage in attracting pollinators. Bumblebees will forage preferentially on warmer flowers, even if equal nutritional reward is available in cooler flowers. This raises the question of whether warmth and sucrose concentration are processed independently by bees, or whether sweetness detectors respond to higher sugar concentration as well as higher temperature. We find that bumblebees can use lower temperature as a cue to higher sucrose reward, showing that bees appear to process the two parameters strictly independently. Moreover, we demonstrate that sucrose concentration takes precedence over warmth, so that when there is a difference in sucrose concentration, bees will typically choose the sweeter feeder, even if the less sweet feeder is several degrees warmer.

  11. Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.

    PubMed

    Lipski, Alexandra; Watzlawick, Hildegard; Ravaud, Stéphanie; Robert, Xavier; Rhimi, Moez; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2013-02-01

    Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region.

  12. Possible mechanism of mannose inhibition of sucrose-supported growth in N2-fixing Azotobacter vinelandii.

    PubMed

    Wong, T Y

    1990-01-01

    When mannose was added to a sucrose-supported culture of Azotobacter vinelandii under N2-fixing conditions, cell growth was inhibited. The degree of inhibition was proportional to the amount of mannose and to the aeration rate (T.-Y. Wong, Appl. Environ. Microbiol. 54:473-475, 1988). In this report, we demonstrate that once inside the cell, mannose was phosphorylated to mannose 6-phosphate. It was then isomerized to fructose 6-phosphate and to glucose 6-phosphate. Mannose inhibited sucrose uptake noncompetitively. The decrease in sucrose uptake after mannose addition coincided with a lower rate of respiration and a decrease in nitrogenase activity. The decrease in sucrose uptake and in the ATP pool may decrease the electron flow and reduce protection of the nitrogenase from O2. Cells became very sensitive to O2, and therefore, cell growth was inhibited under high aeration conditions.

  13. Diverse Exopolysaccharide Producing Bacteria Isolated from Milled Sugarcane: Implications for Cane Spoilage and Sucrose Yield.

    PubMed

    Hector, Stanton; Willard, Kyle; Bauer, Rolene; Mulako, Inonge; Slabbert, Etienne; Kossmann, Jens; George, Gavin M

    2015-01-01

    Bacterial deterioration of sugarcane during harvesting and processing is correlated with significant loss of sucrose yield and the accumulation of bacterial polysaccharides. Dextran, a homoglucan produced by Leuconostoc mesenteroides, has been cited as the primary polysaccharide associated with sugarcane deterioration. A culture-based approach was used to isolate extracellular polysaccharide (EPS) producing bacterial strains from milled sugarcane stalks. Ribosomal RNA sequencing analysis grouped 25 isolates into 4 genera. This study identified 2 bacterial genera not previously associated with EPS production or sucrose degradation. All isolates produced polysaccharide when grown in the presence of sucrose. Monosaccharide analysis of purified polymers by Gas Chromatography revealed 17 EPSs consisting solely of glucose (homoglucans), while the remainder contained traces of mannose or fructose. Dextranase treatment of polysaccharides yielded full digestion profiles for only 11 extracts. Incomplete hydrolysis profiles of the remaining polysaccharides suggest the release of longer oligosaccharides which may interfere with sucrose crystal formation.

  14. Dextran synthesized by Leuconostoc mesenteroides BD1710 in tomato juice supplemented with sucrose.

    PubMed

    Han, Jin; Hang, Feng; Guo, Benheng; Liu, Zhenmin; You, Chunpin; Wu, Zhengjun

    2014-11-04

    The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches.

  15. Plasmid-Determined Ability of a Salmonella tennessee Strain to Ferment Lactose and Sucrose

    PubMed Central

    Johnson, E. M.; Wohlhieter, J. A.; Placek, Bruce P.; Sleet, R. B.; Baron, L. S.

    1976-01-01

    The ability of a Salmonella tennessee strain to ferment both lactose and sucrose was attributed to a conjugally transmissible plasmid, deoxyribonucleic acid molecular weight 164 × 106, bearing the genetic determinants of both fermentation characters. PMID:1107317

  16. Physicochemical and toxicological characterization of a new generic iron sucrose preparation.

    PubMed

    Meier, Thomas; Schropp, Patricia; Pater, Christian; Leoni, Anne-Laure; Khov-Tran, Van Van; Elford, Peter

    2011-01-01

    Intravenous iron preparations are key components in the management of anaemia of various etiologies. These iron-carbohydrate complexes permit safe systemic delivery of iron, whilst protecting from the potential toxic effects of over-saturation. This in turn permits efficient haematopoiesis following erythropoietin administration. Since the rate of release of iron is dependent upon the structure of this iron-carbohydrate complex, it is essential to ensure that an intravenous iron preparation is well characterized and its properties documented. This report describes physicochemical and toxicological studies into a new iron sucrose generic preparation, "Iron Sucrose Azad (ISA)", using the original iron sucrose product as reference. It could be demonstrated that the specifications and physicochemical characteristics of ISA reflect those of the reference product. Furthermore, in a rat model previously shown to identify possible toxicological effects of "unsimilar" iron sucrose preparations, ISA was found to have the same properties as the reference product, with both being well tolerated.

  17. NICU procedures are getting sweeter: development of a sucrose protocol for neonatal procedural pain.

    PubMed

    Mokhnach, Larisa; Anderson, Marilyn; Glorioso, Rachelle; Loeffler, Katie; Shinabarger, Kelly; Thorngate, Lauren; Yates, Marna; Diercks, Kristi; Berkan, Maureen; Hou, Shwu-Shin; Millar, April; Thomas, Karen A; Walker, Wendy; Zbirun, Ilona

    2010-01-01

    Neonates in the neonatal intensive care nursery experience multiple, painful, tissue-damaging procedures daily. Pain among neonates is often underestimated and untreated, producing untoward consequences. A literature review established strong evidence supporting the use of sucrose as an analgesic for minor procedural pain among neonates. A review of unit practices and nurses' experiential evidence initiated the production of a standardized protocol in our unit at the University of Washington Medical Center NICU in Seattle.Nursing practices surrounding sucrose use differed widely in dose, timing, and patient application. We carefully evaluated evidence documenting the effectiveness as well as the safety of sucrose administration and wrote a protocol and practice standards for our primarily premature patient population. This article describes the development and execution of a standardized, nurse-implemented, sucrose protocol to reduce procedural pain.

  18. Brain regions mediating alpha3beta4 nicotinic antagonist effects of 18-MC on methamphetamine and sucrose self-administration.

    PubMed

    Glick, Stanley D; Sell, Elizabeth M; Maisonneuve, Isabelle M

    2008-12-03

    The novel iboga alkaloid congener 18-methoxycoronaridine (18-MC) is a putative anti-addictive agent that has been shown, in rats, to decrease the self-administration of several drugs of abuse. Previous work has established that 18-MC is a potent antagonist at alpha3beta4 nicotinic receptors. Because high densities of alpha3beta4 nicotinic receptors occur in the medial habenula and the interpeduncular nucleus and moderate densities occur in the dorsolateral tegmentum, ventral tegmental area, and basolateral amygdala, the present study was conducted to determine if 18-MC could act in these brain areas to modulate methamphetamine self-administration in rats. Local administration of 18-MC into either the medial habenula, the interpeduncular area or the basolateral amygdala decreased methamphetamine self-administration. Similar results were produced by local administration into the same brain areas of two other alpha3beta4 nicotinic antagonists, mecamylamine and alpha-conotoxin AuIB. Local administration of 18-MC, or the other antagonists, into the dorsolateral tegmentum or the ventral tegmental area had no effect on methamphetamine self-administration. In contrast, local administration of 18-MC and the other antagonists decreased sucrose self-administration when administered into the dorsolateral tegmentum or basolateral amygdala but had no effect when infused into the medial habenula, interpeduncular nucleus, or ventral tegmental area. These data are consistent with the hypothesis that 18-MC decreases methamphetamine self-administration by indirectly modulating the dopaminergic mesolimbic pathway via blockade of alpha3beta4 nicotinic receptors in the habenulo-interpeduncular pathway and the basolateral amygdala. The data also suggest that the basolateral amygdala along with a different pathway involving alpha3beta4 receptors in the dorsolateral tegmentum mediate the effect of 18-MC on sucrose self-administration.

  19. Surfactant-enhanced alkaline flooding field project

    SciTech Connect

    French, T.R.

    1991-10-01

    The Tucker sand of Helper (KS) field is a candidate for surfactant-enhanced alkaline flooding. The geology of the Helper site is typical of many DOE Class I reservoirs. The Tucker sand of Helper field was deposited in a fluvial dominated deltaic environment. Helper oil can be mobilized with either chemical system 2 or chemical system 3, as described in this report. Oil fields in the Gulf Coast region are also good candidates for surfactant-enhanced alkaline flooding. The results from laboratory tests conducted in Berea sandstone cores with oil brine from Helper (KS) field are encouraging. The crude oil is viscous and non-acidic and, yet, was mobilized by the chemical formulations described in this report. Significant amounts of the oil were mobilized under simulated reservoir conditions. The results in Berea sandstone cores were encouraging and should be verified by tests with field core. Consumption of alkali, measured with field core, was very low. Surfactant loss appeared to be acceptable. Despite the good potential for mobilization of Helper oil, certain reservoir characteristics such as low permeability, compartmentalization, and shallow depth place constraints on applications of any chemical system in the Tucker sand. These constraints are typical of many DOE Class I reservoirs. Although Hepler field is not a perfect reservoir in which to apply surfactant- enhanced alkaline flooding, Hepler oil is particularly amenable to mobilization by surfactant-enhanced alkaline systems. A field test is recommended, dependent upon final evaluation of well logs and cores from the proposed pilot area. 14 refs., 21 figs., 10 tabs.

  20. The alkaline earth intercalates of molybdenum disulfide

    NASA Technical Reports Server (NTRS)

    Somoano, R. B.; Hadek, V.; Rembaum, A.; Samson, S.; Woollam, J. A.

    1975-01-01

    Molybdenum disulfide has been intercalated with calcium and strontium by means of the liquid ammonia technique. Chemical, X-ray, and superconductivity data are presented. The X-ray data reveal a lowering of crystal symmetry and increase of complexity of the structure upon intercalation with the alkaline earth metals. The Ca and Sr intercalates start to superconduct at 4 and 5.6 K, respectively, and show considerable anisotropy regarding the critical magnetic field.

  1. Alkaline earth cation extraction from acid solution

    DOEpatents

    Dietz, Mark; Horwitz, E. Philip

    2003-01-01

    An extractant medium for extracting alkaline earth cations from an aqueous acidic sample solution is described as are a method and apparatus for using the same. The separation medium is free of diluent, free-flowing and particulate, and comprises a Crown ether that is a 4,4'(5')[C.sub.4 -C.sub.8 -alkylcyclohexano]18-Crown-6 dispersed on an inert substrate material.

  2. Oxidation catalysts on alkaline earth supports

    DOEpatents

    Mohajeri, Nahid

    2017-03-21

    An oxidation catalyst includes a support including particles of an alkaline earth salt, and first particles including a palladium compound on the support. The oxidation catalyst can also include precious metal group (PMG) metal particles in addition to the first particles intermixed together on the support. A gas permeable polymer that provides a continuous phase can completely encapsulate the particles and the support. The oxidation catalyst may be used as a gas sensor, where the first particles are chemochromic particles.

  3. Inhibition of Alkaline Phosphatase by Several Diuretics

    DTIC Science & Technology

    1980-01-01

    August 20th, 1979) . . Summary , . Acetazolamide, furosemide, ethacrynic acid and chlorothiazide, diuretics of considerable structural diversity, inhibit...Ki is calculated to be 8.4, 7.0, 2.8 and 0.1 mmol/l for acetazolamide, furosemide, ethacrynic acid and chlorothiazide, respectively. Chlorothiazide...is a much more potent inhibitor of alkaline phos- phatase than the other three diuretics. The combination of ethacrynic acid and cysteine, itself an

  4. The effects of fruiting positions on cellulose synthesis and sucrose metabolism during cotton (Gossypium hirsutum L.) fiber development.

    PubMed

    Ma, Yina; Wang, Youhua; Liu, Jingran; Lv, Fengjuan; Chen, Ji; Zhou, Zhiguo

    2014-01-01

    Cotton (Gossypium hirsutum L.) boll positions on a fruiting branch vary in their contribution to yield and fiber quality. Fiber properties are dependent on deposition of cellulose in the fiber cell wall, but information about the enzymatic differences in sucrose metabolism between these fruiting positions is lacking. Therefore, two cotton cultivars with different sensitivities to low temperature were tested in 2010 and 2011 to quantify the effect of fruit positions (FPs) on fiber quality in relation to sucrose content, enzymatic activities and sucrose metabolism. The indices including sucrose content, sucrose transformation rate, cellulose content, and the activities of the key enzymes, sucrose phosphate synthase (SPS), acid invertase (AI) and sucrose synthase (SuSy) which inhibit cellulose synthesis and eventually affect fiber quality traits in cotton fiber, were determined. Results showed that as compared with those of FP1, cellulose content, sucrose content, and sucrose transformation rate of FP3 were all decreased, and the variations of cellulose content and sucrose transformation rate caused by FPs in Sumian 15 were larger than those in Kemian 1. Under FP effect, activities of SPS and AI in sucrose regulation were decreased, while SuSy activity in sucrose degradation was increased. The changes in activities of SuSy and SPS in response to FP effect displayed different and large change ranges between the two cultivars. These results indicate that restrained cellulose synthesis and sucrose metabolism in distal FPs are mainly attributed to the changes in the activities of these enzymes. The difference in fiber quality, cellulose synthesis and sucrose metabolism in response to FPs in fiber cells for the two cotton cultivars was mainly determined by the activities of both SuSy and SPS.

  5. Safety and efficacy of iron sucrose in patients sensitive to iron dextran: North American clinical trial.

    PubMed

    Van Wyck, D B; Cavallo, G; Spinowitz, B S; Adhikarla, R; Gagnon, S; Charytan, C; Levin, N

    2000-07-01

    Sensitivity to iron dextran is a potent obstacle to maintaining optimum iron status in patients with dialysis-associated anemia. As part of the North American clinical trials for iron sucrose injection, we examined the effect of intravenous (IV) iron sucrose in 23 hemodialysis patients with documented sensitivity to iron dextran, ongoing epoetin alfa therapy, and below-target-range hemoglobin (Hgb) levels (<11.0 g/dL). We assigned patients to treatment groups according to whether reactions they had experienced to iron dextran were judged to be mild (n = 16; group A) or severe (n = 7; group B). We prospectively examined adverse events and vital signs after administering 100 mg of IV iron sucrose in each of 10 consecutive dialysis treatment sessions and compared results with those recorded in each of three consecutive dialysis sessions without iron treatment. We administered iron sucrose by IV push over 5 minutes to group A patients and by IV push over 5 minutes or IV infusion over 15 to 30 minutes to group B patients. We did not administer a test dose. Results showed no serious adverse drug reactions after a total of 223 doses of iron sucrose (184 doses by IV push, 39 doses by IV infusion). Intradialytic blood pressure changes after IV iron sucrose injection did not differ from those recorded during dialysis sessions without treatment. An increase in values for Hgb, hematocrit, transferrin saturation, and ferritin, coupled with no significant change in epoetin dose and a decrease in total iron-binding capacity, confirmed the efficacy of iron sucrose injection in managing anemia. We conclude that iron sucrose injection is safe and effective in the management of anemia in patients sensitive to iron dextran and can be administered without a test dose by IV push or infusion.

  6. Role of orexin/hypocretin in conditioned sucrose-seeking in female rats

    PubMed Central

    Cason, Angie M.; Aston-Jones, Gary

    2014-01-01

    The orexin/hypocretin system has recently been implicated in reward-seeking, especially for highly salient food and drug rewards. Given that eating disorders affect women more than men, we reasoned that the orexin system may be strongly engaged in female rats, and during periods of food restriction as we recently reported in male rats. Therefore, the present study examined the involvement of the orexin system in operant responding for sucrose, and in cue-induced reinstatement of extinguished sucrose-seeking, in ad libitum fed vs. food-restricted female subjects. Female Sprague Dawley rats were trained to self-administer sucrose pellets, and we determined the effects of pretreatment with the OxR1 receptor antagonist SB 334867 (SB; 10-30 mg/kg) on fixed ratio (FR) sucrose self-administration, and on cue-induced reinstatement of extinguished sucrose-seeking. SB decreased sucrose self-administration in food-restricted but not in ad libitum-fed females. SB did not alter active lever responding during cue-induced reinstatement of sucrose-seeking in either feeding group. These results confirm our previous results in male rats that signaling at the OxR1 receptor is involved in the sucrose reinforcement and self-administration in food-restricted subjects. However, the finding that SB is ineffective at attenuating cue-induced reinstatement in females, but was effective in food-restricted males, leads us to conclude that food seeking induced by conditioned stimuli engages the orexin system differentially in males and females. PMID:25036612

  7. Role of orexin/hypocretin in conditioned sucrose-seeking in female rats.

    PubMed

    Cason, Angie M; Aston-Jones, Gary

    2014-11-01

    The orexin/hypocretin system has recently been implicated in reward-seeking, especially for highly salient food and drug rewards. Given that eating disorders affect women more than men, we reasoned that the orexin system may be strongly engaged in female rats, and during periods of food restriction as we recently reported in male rats. Therefore, the present study examined the involvement of the orexin system in operant responding for sucrose, and in cue-induced reinstatement of extinguished sucrose-seeking, in ad libitum fed vs. food-restricted female subjects. Female Sprague Dawley rats were trained to self-administer sucrose pellets, and we determined the effects of pretreatment with the OxR1 receptor antagonist SB 334867 (SB; 10-30 mg/kg) on fixed ratio (FR) sucrose self-administration, and on cue-induced reinstatement of extinguished sucrose-seeking. SB decreased sucrose self-administration in food-restricted but not in ad libitum-fed females. SB did not alter active lever responding during cue-induced reinstatement of sucrose-seeking in either feeding group. These results confirm our previous results in male rats that signaling at the OxR1 receptor is involved in the sucrose reinforcement and self-administration in food-restricted subjects. However, the finding that SB is ineffective at attenuating cue-induced reinstatement in females, but was effective in food-restricted males, leads us to conclude that food seeking induced by conditioned stimuli engages the orexin system differentially in males and females.

  8. Sucrose is an early modulator of the key hormonal mechanisms controlling bud outgrowth in Rosa hybrida

    PubMed Central

    Barbier, François; Péron, Thomas; Lecerf, Marion; Perez-Garcia, Maria-Dolores; Barrière, Quentin; Rolčík, Jakub; Boutet-Mercey, Stéphanie; Citerne, Sylvie; Lemoine, Remi; Porcheron, Benoît; Roman, Hanaé; Leduc, Nathalie; Le Gourrierec, José; Bertheloot, Jessica; Sakr, Soulaiman

    2015-01-01

    Sugar has only recently been identified as a key player in triggering bud outgrowth, while hormonal control of bud outgrowth is already well established. To get a better understanding of sugar control, the present study investigated how sugar availability modulates the hormonal network during bud outgrowth in Rosa hybrida. Other plant models, for which mutants are available, were used when necessary. Buds were grown in vitro to manipulate available sugars. The temporal patterns of the hormonal regulatory network were assessed in parallel with bud outgrowth dynamics. Sucrose determined bud entrance into sustained growth in a concentration-dependent manner. Sustained growth was accompanied by sustained auxin production in buds, and sustained auxin export in a DR5::GUS-expressing pea line. Several events occurred ahead of sucrose-stimulated bud outgrowth. Sucrose upregulated early auxin synthesis genes (RhTAR1, RhYUC1) and the auxin efflux carrier gene RhPIN1, and promoted PIN1 abundance at the plasma membrane in a pPIN1::PIN1-GFP-expressing tomato line. Sucrose downregulated both RwMAX2, involved in the strigolactone-transduction pathway, and RhBRC1, a repressor of branching, at an early stage. The presence of sucrose also increased stem cytokinin content, but sucrose-promoted bud outgrowth was not related to that pathway. In these processes, several non-metabolizable sucrose analogues induced sustained bud outgrowth in R. hybrida, Pisum sativum, and Arabidopsis thaliana, suggesting that sucrose was involved in a signalling pathway. In conclusion, we identified potential hormonal candidates for bud outgrowth control by sugar. They are central to future investigations aimed at disentangling the processes that underlie regulation of bud outgrowth by sugar. PMID:25873679

  9. Feeding behavior and social interactions of the Argentine ant Linepithema humile change with sucrose concentration.

    PubMed

    Sola, F J; Josens, R

    2016-08-01

    Liquid sugar baits are well accepted by the Argentine ant Linepithema humile and are suitable for the chemical control of this invasive species. We evaluated how sugar concentrations affect the foraging behavior of L. humile individuals. We quantified feeding variables for individual foragers (ingested load, feeding time and solution intake rate) when feeding on sucrose solutions of different concentrations, as well as post-feeding interactions with nestmates. Solutions of intermediate sucrose concentrations (10-30%) were the most consumed and had the highest intake rates, whereas solutions of high sucrose concentrations (60 and 70%) resulted in extended feeding times, low intake rates and ants having smaller crop loads. In terms of post-feeding interactions, individuals fed solutions of intermediate sucrose concentrations (20%) had the highest probability of conducting trophallaxis and the smallest latency to drop exposure (i.e. lowest time delay). Trophallaxis duration increased with increasing sucrose concentrations. Behavioral motor displays, including contacts with head jerking and walking with a gaster waggle, were lowest for individuals that ingested the more dilute sucrose solution (5%). These behaviors have been previously suggested to act as a communication channel for the activation and/or recruitment of nestmates. We show here that sucrose concentration affects feeding dynamics and modulates decision making related to individual behavior and social interactions of foragers. Our results indicate that intermediate sucrose concentrations (ca. 20%), appear to be most appropriate for toxic baits because they promote rapid foraging cycles, a high crop load per individual, and a high degree of stimulation for recruitment.

  10. Sucrose is an early modulator of the key hormonal mechanisms controlling bud outgrowth in Rosa hybrida.

    PubMed

    Barbier, François; Péron, Thomas; Lecerf, Marion; Perez-Garcia, Maria-Dolores; Barrière, Quentin; Rolčík, Jakub; Boutet-Mercey, Stéphanie; Citerne, Sylvie; Lemoine, Remi; Porcheron, Benoît; Roman, Hanaé; Leduc, Nathalie; Le Gourrierec, José; Bertheloot, Jessica; Sakr, Soulaiman

    2015-05-01

    Sugar has only recently been identified as a key player in triggering bud outgrowth, while hormonal control of bud outgrowth is already well established. To get a better understanding of sugar control, the present study investigated how sugar availability modulates the hormonal network during bud outgrowth in Rosa hybrida. Other plant models, for which mutants are available, were used when necessary. Buds were grown in vitro to manipulate available sugars. The temporal patterns of the hormonal regulatory network were assessed in parallel with bud outgrowth dynamics. Sucrose determined bud entrance into sustained growth in a concentration-dependent manner. Sustained growth was accompanied by sustained auxin production in buds, and sustained auxin export in a DR5::GUS-expressing pea line. Several events occurred ahead of sucrose-stimulated bud outgrowth. Sucrose upregulated early auxin synthesis genes (RhTAR1, RhYUC1) and the auxin efflux carrier gene RhPIN1, and promoted PIN1 abundance at the plasma membrane in a pPIN1::PIN1-GFP-expressing tomato line. Sucrose downregulated both RwMAX2, involved in the strigolactone-transduction pathway, and RhBRC1, a repressor of branching, at an early stage. The presence of sucrose also increased stem cytokinin content, but sucrose-promoted bud outgrowth was not related to that pathway. In these processes, several non-metabolizable sucrose analogues induced sustained bud outgrowth in R. hybrida, Pisum sativum, and Arabidopsis thaliana, suggesting that sucrose was involved in a signalling pathway. In conclusion, we identified potential hormonal candidates for bud outgrowth control by sugar. They are central to future investigations aimed at disentangling the processes that underlie regulation of bud outgrowth by sugar.

  11. Sucrose Exposure in Early Life Alters Adult Motivation and Weight Gain

    PubMed Central

    Frazier, Cristianne R. M.; Mason, Peggy; Zhuang, Xiaoxi; Beeler, Jeff A.

    2008-01-01

    The cause of the current increase in obesity in westernized nations is poorly understood but is frequently attributed to a ‘thrifty genotype,’ an evolutionary predisposition to store calories in times of plenty to protect against future scarcity. In modern, industrialized environments that provide a ready, uninterrupted supply of energy-rich foods at low cost, this genetic predisposition is hypothesized to lead to obesity. Children are also exposed to this ‘obesogenic’ environment; however, whether such early dietary experience has developmental effects and contributes to adult vulnerability to obesity is unknown. Using mice, we tested the hypothesis that dietary experience during childhood and adolescence affects adult obesity risk. We gave mice unlimited or no access to sucrose for a short period post-weaning and measured sucrose-seeking, food consumption, and weight gain in adulthood. Unlimited access to sucrose early in life reduced sucrose-seeking when work was required to obtain it. When high-sugar/high-fat dietary options were made freely-available, however, the sucrose-exposed mice gained more weight than mice without early sucrose exposure. These results suggest that early, unlimited exposure to sucrose reduces motivation to acquire sucrose but promotes weight gain in adulthood when the cost of acquiring palatable, energy dense foods is low. This study demonstrates that early post-weaning experience can modify the expression of a ‘thrifty genotype’ and alter an adult animal's response to its environment, a finding consistent with evidence of pre- and peri-natal programming of adult obesity risk by maternal nutritional status. Our findings suggest the window for developmental effects of diet may extend into childhood, an observation with potentially important implications for both research and public policy in addressing the rising incidence of obesity. PMID:18797507

  12. Alkaline flooding for enhanced oil recovery

    SciTech Connect

    Gittler, W.E.

    1983-09-01

    There are over 12 active projects of varying size using one of 3 major types of alkaline agents. These include sodium silicate, caustic soda, and soda ash. Among the largest pilots currently is the THUMS project in the Wilmington field, California. Plans called for the injection of a 4% weight concentration of sodium orthosilicate over a 60% PV. Through the first 3 yr, over 27 million bbl of chemicals have been injected. Gulf Oil is operating several alkaline floods, one of which is located off shore in the Quarantine Bay field, Louisiana. In this pilot, sodium hydroxide in a weight concentration of 5 to 12% is being injected. Belco Petroleum Corp. has reported that their pilot operating in the Isenhour Unit in Wyoming is using a .5% weight concentration of soda ash in conjunction with a polymer. Other uses for alkaline agents in chemical flooding include the use of silicate as a preflush or sacrificial agent in micellar/polymer and surfactant recovery systems. In addition, caustic has been tested in the surface-mixed caustic emulsion process while orthosilicate has been tested in a recovery method known as mobility-controlled caustic floods.

  13. Alkaline phosphatase of Physarum polycephalum is insoluble.

    PubMed

    Furuhashi, Kiyoshi

    2008-02-01

    The plasmodia of Physarum polycephalum grow as multinucleated cells in the presence of sufficient humidity and nutriment. Under non-illuminating conditions, stresses such as low temperature or high concentrations of salts transform the plasmodia into spherules whereas dehydration induces sclerotization. Some phosphatases including protein phosphatase and acid phosphatase have been purified from the plasmodia, but alkaline phosphatase remains to be elucidated. Phosphatase of the plasmodia, spherules and sclerotia was visualized by electrophoresis gel-staining assay using 5-bromo-4-chloro-3-indolyl phosphate. Insoluble fractions of the sclerotia were abundant in phosphatase activity. The phosphatase which was extracted by nonionic detergent was subjected to column chromatography and preparative electrophoresis. Purified phosphatase showed the highest activity at pH 8.8, indicating that this enzyme belongs to alkaline phosphatase. The apparent molecular mass from sodium dodecyl sulfate-polyacrylamide gel electrophoresis under non-reducing condition was estimated to be 100 kDa whereas that under reducing was 105 kDa. An amount of 1% sodium dodecyl sulfate or 0.5 M NaCl had no effects on the activity although the phosphatase showed heat instability, Mg(2+)-dependency and sensitivity to 2-glycerophosphate or NaF. The extracting conditions and enzymatic properties suggest that this alkaline phosphatase which is in a membrane-bound form plays important roles in phosphate metabolism.

  14. Protective effect of sucrose on spray drying of oxyhemoglobin.

    PubMed

    Labrude, P; Rasolomanana, M; Vigneron, C; Thirion, C; Chaillot, B

    1989-03-01

    As far as we know, spray drying has previously not been applied to oxyhemoglobin, undoubtedly because of the sensitivity of oxyhemoglobin to temperature and oxidation. Our experience with freeze drying encouraged us to perform spray-drying trials in order to compare the results of the two methods, in the absence and the presence of protective compounds. Spray drying of hemoglobin without a protective compound led, as in freeze drying, to formation of a percentage of methemoglobin (50%) that makes it unsuitable for transporting oxygen. In the presence of 0.25 M sucrose (optimum) and at 80-100 degrees C, the functional properties of the hemoglobin were well preserved (methemoglobin approximately 4%), and the residual humidity was limited to approximately 3%. Structural investigation by optical circular dichroism confirmed the results obtained by freeze drying: in the presence of an effective protector, the spectra were similar to those of control hemoglobin and the immediate environment of the heme did not undergo any major change. Electron spin resonance absorption bands in all samples were similar for each value of the spectral decomposition factor, g. This suggests that the structure of the heme is not altered by desiccation and that the protector does not penetrate into the heme pocket since it would have disturbed the symmetry of the crystalline field. Fundamentally, these results are equivalent or similar to those observed with freeze drying; since spray drying is a different process of dehydration, the results indicate a lack of specificity in the phenomena of oxidation or of protection affecting hemoglobin.

  15. Secondary relaxations in supercooled and glassy sucrose-borate aqueous solutions.

    PubMed

    Longinotti, M Paula; Corti, Horacio R; Pablo, Juan J de

    2008-10-13

    The dielectric relaxation spectra of concentrated aqueous solutions of sucrose-borate mixtures have been measured in the supercooled and glassy regions in the frequency range of 40Hz to 2MHz. The secondary (beta) relaxation process was analyzed in the temperature range 183-233K at water contents between 20 and 30wt%. The relaxation times were obtained, and the activation energy of that process was calculated. In order to assess the effect of borate on the relaxation of disaccharide-water mixtures, we also studied the dielectric behavior of sucrose aqueous solutions in the same range of temperatures and water contents. Our findings support the view that, beyond a water content of approximately 20wt%, the secondary relaxation of water-sucrose and water-sucrose-borate mixtures adopts a universal character that can be explained in terms of a simple exponential function of the temperature scaled by the glass transition temperature (T(g)). The behavior observed for water-sucrose and water-sucrose-borate mixtures is compared with previous results obtained in other water-carbohydrate systems.

  16. Sucrose-induced Receptor Kinase SIRK1 Regulates a Plasma Membrane Aquaporin in Arabidopsis*

    PubMed Central

    Wu, Xu Na; Sanchez Rodriguez, Clara; Pertl-Obermeyer, Heidi; Obermeyer, Gerhard; Schulze, Waltraud X.

    2013-01-01

    The transmembrane receptor kinase family is the largest protein kinase family in Arabidopsis, and it contains the highest fraction of proteins with yet uncharacterized functions. Here, we present functions of SIRK1, a receptor kinase that was previously identified with rapid transient phosphorylation after sucrose resupply to sucrose-starved seedlings. SIRK1 was found to be an active kinase with increasing activity in the presence of an external sucrose supply. In sirk1 T-DNA insertional mutants, the sucrose-induced phosphorylation patterns of several membrane proteins were strongly reduced; in particular, pore-gating phosphorylation sites in aquaporins were affected. SIRK1-GFP fusions were found to directly interact with aquaporins in affinity pull-down experiments on microsomal membrane vesicles. Furthermore, protoplast swelling assays of sirk1 mutants and SIRK1-GFP expressing lines confirmed a direct functional interaction of receptor kinase SIRK1 and aquaporins as substrates for phosphorylation. A lack of SIRK1 expression resulted in the failure of mutant protoplasts to control water channel activity upon changes in external sucrose concentrations. We propose that SIRK1 is involved in the regulation of sucrose-specific osmotic responses through direct interaction with and activation of an aquaporin via phosphorylation and that the duration of this response is controlled by phosphorylation-dependent receptor internalization. PMID:23820729

  17. Isomaltulose production from sucrose by Protaminobacter rubrum immobilized in calcium alginate.

    PubMed

    de Oliva-Neto, P; Menão, Paula T P

    2009-09-01

    Different culture conditions for Protaminobacter rubrum and enzymatic reaction parameters were evaluated with the goal of improving isomaltulose production. P. rubrum was grown in a medium with 1% (w/v) cane molasses and 0.5% yeast extract and achieved a maximum cell yield Y(x/s) of 0.295 g of cells/g sucrose and a specific growth rate (mu) of 0.192 h(-1). The immobilization of P. rubrum cells was carried out with calcium alginate, glutaraldehyde and polyethyleneimine. Stabile immobilized cell pellets were obtained and used 24 times in batch processes. Enzymatic conversion was carried out at different sucrose concentrations and in pH 6 medium with 70% (w/v) sucrose at 30 degrees C an isomaltulose yield of 89-94% (w/v) was obtained. The specific activity of the P. rubrum immobilized pellets in calcium alginate at 30 degrees C ranged from 1.6 to 4.0 g isomaltulose g(-1) pellet h(-1), respectively with 70% and 65% sucrose solution, while in lower sucrose concentration had higher specific activities presumably due to substrate inhibition of the isomaltulose synthase in higher sucrose concentrations.

  18. Is there a specific role for sucrose in sports and exercise performance?

    PubMed

    Wallis, Gareth A; Wittekind, Anna

    2013-12-01

    The consumption of carbohydrate before, during, and after exercise is a central feature of the athlete's diet, particularly those competing in endurance sports. Sucrose is a carbohydrate present within the diets of athletes. Whether sucrose, by virtue of its component monosaccharides glucose and fructose, exerts a meaningful advantage for athletes over other carbohydrate types or blends is unclear. This narrative reviews the literature on the influence of sucrose, relative to other carbohydrate types, on exercise performance or the metabolic factors that may underpin exercise performance. Inference from the research to date suggests that sucrose appears to be as effective as other highly metabolizable carbohydrates (e.g., glucose, glucose polymers) in providing an exogenous fuel source during endurance exercise, stimulating the synthesis of liver and muscle glycogen during exercise recovery and improving endurance exercise performance. Nonetheless, gaps exist in our understanding of the metabolic and performance consequences of sucrose ingestion before, during, and after exercise relative to other carbohydrate types or blends, particularly when more aggressive carbohydrate intake strategies are adopted. While further research is recommended and discussed in this review, based on the currently available scientific literature it would seem that sucrose should continue to be regarded as one of a variety of options available to help athletes achieve their specific carbohydrate-intake goals.

  19. Temporal kinetics of the transcriptional response to carbon depletion and sucrose readdition in Arabidopsis seedlings.

    PubMed

    Cookson, Sarah Jane; Yadav, Umesh Prasad; Klie, Sebastian; Morcuende, Rosa; Usadel, Björn; Lunn, John Edward; Stitt, Mark

    2016-04-01

    To investigate whether the transcriptional response to carbon (C) depletion and sucrose resupply depends on the duration and severity of the C depletion, Arabidopsis seedlings were grown in liquid culture and harvested 3, 6, 12, 24, 48 and 72 h after removing sucrose from the medium and 30 min after resupplying sucrose at each time. Expression profiling revealed early transcriptional inhibition of cell wall synthesis and remodelling of signalling, followed by induction of C recycling and photosynthesis and general inhibition of growth. The temporal sequence differed from the published response to progressive exhaustion of C during a night and extended night in vegetatively growing plants. The response to sucrose readdition was conserved across the C-depletion time course. Intriguingly, the vast majority of rapidly responding transcripts decreased rather than increased. The majority of transcripts that respond rapidly to sucrose and many transcripts that respond during C depletion also decrease after treating seedlings with the transcriptional inhibitor cordycepin A. Comparison with published responses to overexpression of otsA, AKIN10 and bZIP11 revealed that many genes that respond to C depletion, and especially sucrose resupply, respond to one or more of these C-signalling components. Thus, multiple factors contribute to C responsiveness, including many signalling components, transcriptional regulation and transcript turnover.

  20. Inulin and erythritol as sucrose replacers in short-dough cookies: sensory, fracture, and acoustic properties.

    PubMed

    Laguna, Laura; Primo-Martín, Cristina; Salvador, Ana; Sanz, Teresa

    2013-05-01

    The effect of sucrose replacement by erythritol and inulin was studied in short-dough cookies using instrumental and sensory analysis. Two levels of replacement were used (25% and 50% of total sucrose content). Descriptive sensory analysis showed that the sucrose replacement affects visual and texture cookies characteristics, being the differences perceived by mouth greater than by hand. In general, sucrose substitutes produced a less crispy cookie and lower consumer acceptability, with the exception of 25% sucrose replacement by inulin. Matrix aeration attributes such as open and crumbly obtained by trained panel were important properties, and correlated positively with consumer acceptance and negatively with maximum force at break (hardness). Inulin cookies sensory properties were more similar to the control than the erythritol cookies. Also, consumer overall acceptance decreased significantly with sucrose replacement by erythritol. The analysis of texture and sound revealed that inulin cookies were softer whereas erythritol cookies were harder in comparison with control cookies; despite this difference, inulin cookies had similar sound characteristics to erythritol cookies.

  1. Production of L-ornithine from sucrose and molasses by recombinant Corynebacterium glutamicum.

    PubMed

    Zhang, Yuan-Yuan; Bu, Yi-Fan; Liu, Jian-Zhong

    2015-09-01

    Sucrose and molasses are attractive raw materials for industrial fermentation. Although Corynebacterium glutamicum shows sucrose-utilizing activity, sucrose or molasses is only a fraction of carbon source used in the fermentation medium in most works. An engineered C. glutamicum strain was constructed for producing L-ornithine with sucrose or molasses as a sole carbon source by transferring Mannheimia succiniciproducens β-fructofuranosidase gene (sacC). The engineered strain, C. glutamicum ΔAPE6937R42 (pEC-sacC), produced 22.0 g/L of L-ornithine with sucrose as the sole carbon source, which is on par with that obtained by the parent strain C. glutamicum ΔAPE6937R42 with glucose as the sole carbon. The resulting strain C. glutamicum ΔAPE6937R42 (pEC-sacC) produced 27.0 g/L of L-ornithine with molasses as the sole carbon source, which is higher than that obtained by the parent strain C. glutamicum ΔAPE6937R42 with glucose as the sole carbon. This strategy can be applied for developing sucrose- or molasses-utilizing industrial strains.

  2. A nicotinic acetylcholine receptor agonist affects honey bee sucrose responsiveness and decreases waggle dancing.

    PubMed

    Eiri, Daren M; Nieh, James C

    2012-06-15

    A nicotinic acetylcholine receptor agonist, imidacloprid, impairs memory formation in honey bees and has general effects on foraging. However, little is known about how this agonist affects two specific aspects of foraging: sucrose responsiveness (SR) and waggle dancing (which recruits nestmates). Using lab and field experiments, we tested the effect of sublethal doses of imidacloprid on (1) bee SR with the proboscis extension response assay, and (2) free-flying foragers visiting and dancing for a sucrose feeder. Bees that ingested imidacloprid (0.21 or 2.16 ng bee(-1)) had higher sucrose response thresholds 1 h after treatment. Foragers that ingested imidacloprid also produced significantly fewer waggle dance circuits (10.5- and 4.5-fold fewer for 50% and 30% sucrose solutions, respectively) 24 h after treatment as compared with controls. However, there was no significant effect of imidacloprid on the sucrose concentrations that foragers collected at a feeder 24 h after treatment. Thus, imidacloprid temporarily increased the minimum sucrose concentration that foragers would accept (short time scale, 1 h after treatment) and reduced waggle dancing (longer time scale, 24 h after treatment). The effect of time suggests different neurological effects of imidacloprid resulting from the parent compound and its metabolites. Waggle dancing can significantly increase colony food intake, and thus a sublethal dose (0.21 ng bee(-1), 24 p.p.b.) of this commonly used pesticide may impair colony fitness.

  3. Intravenous Iron Sucrose for Children with Iron Deficiency Failing to Respond to Oral Iron Therapy

    PubMed Central

    Crary, Shelley E.; Hall, Katherine; Buchanan, George R.

    2010-01-01

    Background For decades parenteral iron has been used in patients with iron deficiency unresponsive to oral iron therapy and in hemodialysis-dependent patients receiving erythropoietin. Newer intravenous (IV) iron formulations such as iron sucrose have replaced high molecular weight iron dextran in dialysis patients; however, the use of parenteral iron in children without renal disease has not been well defined. Procedure Pharmacy records were reviewed on children (≤ 18 yrs of age) who received IV iron sucrose at Children's Medical Center Dallas between January 1, 2004 and June 30, 2009. Patients who received iron sucrose for chronic renal disease were excluded from analysis. Results Thirty-eight children received iron sucrose for non-renal indications, 13 with iron deficiency refractory to oral iron therapy, 13 with iron malabsorption or dependence on parenteral nutrition, 7 for chronic gastrointestinal blood loss, and 5 for miscellaneous indications. Among these 38 children, who received a total of 510 doses of IV iron sucrose, there were only 6 adverse reactions. Patients in all categories had a good response to the iron sucrose, with a median hemoglobin rise of 1.9 – 3.1 g/dl depending on the indication. Conclusions Parenteral iron is a safe and effective means to treat iron deficiency in children who cannot receive or do not respond to oral iron due to intolerance, poor adherence or iron malabsorption. PMID:21298748

  4. Kinetics and thermodynamics of sucrose hydrolysis from real-time enthalpy and heat capacity measurements.

    PubMed

    Tombari, E; Salvetti, G; Ferrari, C; Johari, G P

    2007-01-25

    We report a real time study of the enthalpy release and heat capacity during the course of HCl-catalyzed hydrolysis of sucrose to fructose and glucose. Measurements were performed during both isothermal conditions and during slow heating and then cooling at a controlled rate. The reaction rate constant of the first-order kinetics follows an Arrhenius relation with activation energy of 109.2 kJ/mol of sucrose. On hydrolysis, the enthalpy decreases by 14.4 kJ/mol of sucrose at 310 K, and the heat capacity, Cp, increases by 61 J mol-1 K-1 of sucrose in the solution. The enthalpy of hydrolysis decreases with increase in the temperature and DeltaCp on hydrolysis increases. The effects are attributed to change in the configurational and vibrational partition functions as one covalent bond in sucrose breaks to form two molecules, which then individually form additional hydrogen bonds and alter the water's structure in the solution. Cp of the solution increases with temperature less rapidly before sucrose hydrolysis than after it. This may reflect an increase in the configurational contribution to Cp as the hydrogen bond population changes.

  5. Frequency of sucrose exposure on the cariogenicity of a biofilm-caries model

    PubMed Central

    Díaz-Garrido, Natalia; Lozano, Carla; Giacaman, Rodrigo A.

    2016-01-01

    Objective: Although sucrose is considered the most cariogenic carbohydrate in the human diet, the question of how many exposures are needed to induce damage on the hard dental tissues remains unclear. To approach this question, different frequencies of daily sucrose exposure were tested on a relevant biological caries model. Materials and Methods: Biofilms of the Streptococcus mutans were formed on enamel slabs and exposed to cariogenic challenges with 10% sucrose for 5 min at 0, 1, 3, 5, 8, or 10 times per day. After 5 days, biofilms were retrieved to analyze biomass, protein content, viable bacteria, and polysaccharide formation. Enamel demineralization was evaluated by percentage of microhardness loss (percentage surface hardness loss [%SHL]). Results: Biomass, protein content, polysaccharide production, acidogenicity of the biofilm, and %SHL proportionally increased with the number of daily exposures to sucrose (P < 0.05). One daily sucrose exposure was enough to induce 20% more demineralization than the negative unexposed control. Higher frequencies induced greater demineralization and more virulent biofilms, but eight and ten exposures were not different between them in most of the analyzed variables (P > 0.05). Conclusions: Higher sucrose exposure seems to increase cariogenicity, in a frequency-dependent manner, by the modification of bacterial virulent properties. PMID:27403051

  6. [Effects of salicylic acid on sucrose metabolism of tomato seedlings under NaCl stress].

    PubMed

    Su, Yue; Li, Tian-Lai; Li, Nan; Yang, Feng-Jun; Lu, Shao-Wei

    2009-06-01

    A water culture experiment was conducted with the seedlings of tomato (Lycopersicon esculentum Mill.) cultivar Liaoyuanduoli to study the effects of salicylic acid (SA) on their sucrose metabolism under NaCl stress. The seedlings were treated with different concentrations (100, 300, and 500 mg x L(-1)) of SA, and the contents of sucrose, glucose, and fructose as well as the related enzyme activities of sucrose metabolism, including acid invertase (AI), neutral invertase (NI), sucrose phosphate synthase (SPS), and sucrose synthase (SS), in seedling leaves were determined. Under NaCl stress, SA could maintain or enhance the leaf fructose and glucose contents and the leaf AI, NI, SPS and SS activities, with the highest increment of fructose and glucose contents being 30.0% and 31.1% and that of AI, NI, SPS and SS activities being 24.7%, 27.9%, 22.0% and 24.5%, respectively, in comparing with no SA application, while had less effect on the leaf sucrose content, which suggested that SA could play a protective role in the NaCl-tolerance of tomato seedlings via enhancing the leaf invertase activity to increase leaf fructose and glucose contents. The best alleviating effect was observed at 500 mg x L(-1) of SA.

  7. Membrane Potentials of the Lobster Giant Axon Obtained by Use of the Sucrose-Gap Technique

    PubMed Central

    Julian, Fred J.; Moore, John W.; Goldman, David E.

    1962-01-01

    A method similar to the sucrose-gap technique introduced be Stäpfli is described for measuring membrane potential and current in singly lobster giant axons (diameter about 100 micra). The isotonic sucrose solution used to perfuse the gaps raises the external leakage resistance so that the recorded potential is only about 5 per cent less than the actual membrane potential. However, the resting potential of an axon in the sucrose-gap arrangement is increased 20 to 60 mv over that recorded by a conventional micropipette electrode when the entire axon is bathed in sea water. A complete explanation for this effect has not been discovered. The relation between resting potential and external potassium and sodium ion concentrations shows that potassium carries most of the current in a depolarized axon in the sucrose-gap arrangement, but that near the resting potential other ions make significant contributions. Lowering the external chloride concentration decreases the resting potential. Varying the concentration of the sucrose solution has little effect. A study of the impedance changes associated with the action potential shows that the membrane resistance decreases to a minimum at the peak of the spike and returns to near its initial value before repolarization is complete (a normal lobster giant axon action potential does not have an undershoot). Action potentials recorded simultaneously by the sucrose-gap technique and by micropipette electrodes are practically superposable. PMID:14452759

  8. Isolation of the catalytically competent small subunit of ribulose bisphosphate carboxylase/oxygenase from spinach under an extremely alkaline condition.

    PubMed

    Incharoensakdi, A; Takabe, T; Takabe, T; Akazawa, T

    1986-07-16

    A method for isolating the small subunit (B) of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from spinach leaf using an alkaline buffer (pH 11.2) in combination with sucrose gradient centrifugation is described. Although the yield of isolated subunit B (ca. 20%) was comparable to that previously described (ca. 25%) using the acid precipitation method [Andrews, T.J. and Lorimer, G.H. (1985) J. Biol. Chem. 260: 4632-4636], the isolated subunit B in this report suffered less denaturation (ca. 30%) as estimated from kinetic analysis of its reassembly with large subunit (A) derived from Aphanothece halophytica. Studies on the kinetic properties of the reassembled enzyme molecules suggested that spinach subunit B does not influence the affinity of the enzyme for substrate CO2. The catalytic core (A8) of spinach RuBisCO could not be isolated in the native form.

  9. Effect of different carbon sources on decolourisation of an industrial textile dye under alkaline-saline conditions.

    PubMed

    Ottoni, Cristiane; Lima, Luis; Santos, Cledir; Lima, Nelson

    2014-01-01

    White-rot fungal strains of Trametes versicolor and Phanerochaete chrysosporium were selected to study the decolourisation of the textile dye, Reactive Black 5, under alkaline-saline conditions. Free and immobilised T. versicolor cells showed 100 % decolourisation in the growth medium supplemented with 15 g l(-1) NaCl, pH 9.5 at 30 °C in liquid batch culture. Continuous culture experiments were performed in a fixed-bed reactor using free and immobilised T. versicolor cells and allowed 85-100 % dye decolourisation. The immobilisation conditions for the biomass and the additional supply of carbon sources improved the decolourisation performance during a long-term trial of 40 days. Lignin peroxidase, laccase and glyoxal oxidase activities were detected during the experiments. The laccase activity varied depending on carbon source utilized and glycerol-enhanced laccase activity compared to sucrose during extended growth.

  10. Mesozoic mafic alkaline magmatism of southern Scandinavia

    NASA Astrophysics Data System (ADS)

    Tappe, Sebastian

    2004-11-01

    More than 100 volcanic necks in central Scania (southern Sweden) are the product of Jurassic continental rift-related mafic alkaline magmatism at the southwest margin of the Baltic Shield. They are mainly basanites, with rarer melanephelinites. Both rock groups display overlapping primitive Mg-numbers, Cr and Ni contents, steep chondrite-normalized rare earth element patterns (LaN /YbN = 17 27) and an overall enrichment in incompatible elements. However, the melanephelinites are more alkaline and have stronger high field strength element enrichment than the basanites. The existence of distinct primary magmas is also indicated by heterogeneity in highly incompatible element ratios (e.g. Zr/Nb, La/Nb). Trace element modelling indicates that the magmas were generated by comparably low degrees of melting of a heterogeneous mantle source. Such a source can best be explained by a metasomatic overprint of the mantle lithosphere by percolating evolved melts. The former existence of such alkaline trace element-enriched melts can be demonstrated by inversion of the trace element content of green-core clinopyroxenes and anorthoclase which occur as xenocrysts in the melanephelinites and are interpreted as being derived from crystallization of evolved mantle melts. Jurassic magmatic activity in Scania was coeval with the generation of nephelinites in the nearby Egersund Basin (Norwegian North Sea). Both Scanian and North Sea alkaline magmas share similar trace element characteristics. Mantle enrichment processes at the southwest margin of the Baltic Shield and the North Sea Basin generated trace element signatures similar to those of ocean island basalts (e.g. low Zr/Nb and La/Nb) but there are no indications of plume activity during the Mesozoic in this area. On the contrary, the short duration of rifting, absence of extensive lithospheric thinning, and low magma volumes argue against a Mesozoic mantle plume. It seems likely that the metasomatic imprint resulted from the

  11. Alkaline and ultrasound assisted alkaline pretreatment for intensification of delignification process from sustainable raw-material.

    PubMed

    Subhedar, Preeti B; Gogate, Parag R

    2014-01-01

    Alkaline and ultrasound-assisted alkaline pretreatment under mild operating conditions have been investigated for intensification of delignification. The effect of NaOH concentration, biomass loading, temperature, ultrasonic power and duty cycle on the delignification has been studied. Most favorable conditions for only alkaline pretreatment were alkali concentration of 1.75 N, solid loading of 0.8% (w/v), temperature of 353 K and pretreatment time of 6 h and under these conditions, 40.2% delignification was obtained. In case of ultrasound-assisted alkaline approach, most favorable conditions obtained were alkali concentration of 1N, paper loading of 0.5% (w/v), sonication power of 100 W, duty cycle of 80% and pretreatment time of 70 min and the delignification obtained in ultrasound-assisted alkaline approach under these conditions was 80%. The material samples were characterized by FTIR, SEM, XRD and TGA technique. The lignin was recovered from solution by precipitation method and was characterized by FTIR, GPC and TGA technique.

  12. Alkaline solution/binder ratio as a determining factor in the alkaline activation of aluminosilicates

    SciTech Connect

    Ruiz-Santaquiteria, C.; Fernandez-Jimenez, A.; Palomo, A.

    2012-09-15

    This study investigates the effect of the alkaline solution/binder (S/B) ratio on the composition and nanostructure of the reaction products generated in the alkaline activation of aluminosilicates. The experiments used two mixtures of fly ash and dehydroxylated white clay and for each of these, varying proportions of the solution components. The alkali activator was an 8 M NaOH solution (with and without sodium silicate) used at three S/B ratios: 0.50, 0.75 and 1.25. The {sup 29}Si, {sup 27}Al MAS NMR and XRD characterisation of the reaction products reveal that for ratios nearest the value delivering suitable paste workability, the reaction-product composition and structure depend primarily on the nature and composition of the starting materials and the alkaline activator used. However, when an excess alkaline activator is present in the system, the reaction products tend to exhibit SiO{sub 2}/Al{sub 2}O{sub 3} ratios of approximately 1, irrespective of the composition of the starting binder or the alkaline activator.

  13. Density Visualization

    ERIC Educational Resources Information Center

    Keiter, Richard L.; Puzey, Whitney L.; Blitz, Erin A.

    2006-01-01

    Metal rods of high purity for many elements are now commercially available and may be used to construct a display of relative densities. We have constructed a display with nine metal rods (Mg, Al, Ti, V, Fe, Cu, Ag, Pb, and W) of equal mass whose densities vary from 1.74 to 19.3 g cm[superscript -3]. The relative densities of the metals may be…

  14. Alkaline degradation of invert sugar from molasses.

    PubMed

    Yang, Byung Y; Montgomery, Rex

    2007-11-01

    Sugar beet and sugar cane molasses have been shown to be suitable starting materials for producing de-icer preparations. The sucrose in the molasses is hydrolyzed to glucose and fructose by invertase. The reducing sugars are then degraded by NaOH, the alkali being neutralized by the sugar acids produced, resulting in an increase of the ionic strength and consequently depression of the freezing point of the resulting solution. For the preparation of de-icers, the desired freezing point depression to a temperature of less than about -20 degrees C can be achieved by adjusting the amount and concentration of the alkali metal hydroxide used. The resulting products are biodegradable and eliminate the corrosive effects associated with the use of conventional chloride salts. Degradation of invert sugar by NaOH has been achieved without an external heat source. The reaction products showed the same freezing point depression as seen in the degradation products from pure glucose.

  15. Cellulose Deficiency Is Enhanced on Hyper Accumulation of Sucrose by a H+-Coupled Sucrose Symporter1[OPEN

    PubMed Central

    Yeats, Trevor H.; Sorek, Hagit

    2016-01-01

    In order to understand factors controlling the synthesis and deposition of cellulose, we have studied the Arabidopsis (Arabidopsis thaliana) double mutant shaven3 shaven3-like1 (shv3svl1), which was shown previously to exhibit a marked cellulose deficiency. We discovered that exogenous sucrose (Suc) in growth medium greatly enhances the reduction in hypocotyl elongation and cellulose content of shv3svl1. This effect was specific to Suc and was not observed with other sugars or osmoticum. Live-cell imaging of fluorescently labeled cellulose synthase complexes revealed a slowing of cellulose synthase complexes in shv3svl1 compared with the wild type that is enhanced in a Suc-conditional manner. Solid-state nuclear magnetic resonance confirmed a cellulose deficiency of shv3svl1 but indicated that cellulose crystallinity was unaffected in the mutant. A genetic suppressor screen identified mutants of the plasma membrane Suc/H+ symporter SUC1, indicating that the accumulation of Suc underlies the Suc-dependent enhancement of shv3svl1 phenotypes. While other cellulose-deficient mutants were not specifically sensitive to exogenous Suc, the feronia (fer) receptor kinase mutant partially phenocopied shv3svl1 and exhibited a similar Suc-conditional cellulose defect. We demonstrate that shv3svl1, like fer, exhibits a hyperpolarized plasma membrane H+ gradient that likely underlies the enhanced accumulation of Suc via Suc/H+ symporters. Enhanced intracellular Suc abundance appears to favor the partitioning of carbon to starch rather than cellulose in both mutants. We conclude that SHV3-like proteins may be involved in signaling during cell expansion that coordinates proton pumping and cellulose synthesis. PMID:27013021

  16. Expression patterns, activities and carbohydrate-metabolizing regulation of sucrose phosphate synthase, sucrose synthase and neutral invertase in pineapple fruit during development and ripening.

    PubMed

    Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

    2012-01-01

    Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion.

  17. Development of an integrated electrochemical biosensor for sucrose and its implementation in a continuous flow system for the simultaneous monitoring of sucrose, fructose and glucose.

    PubMed

    Vargas, E; Gamella, M; Campuzano, S; Guzmán-Vázquez de Prada, A; Ruiz, M A; Reviejo, A J; Pingarrón, J M

    2013-02-15

    An integrated amperometric sucrose biosensor involving a 3-mercaptopropionic acid (MPA) self-assembled monolayer (SAM)-modified gold disk electrode (AuE) and coimmobilization of the enzymes invertase (INV) and fructose dehydrogenase (FDH) as well as the redox mediator tetrathiafulvalene (TTF) by means of a dialysis membrane is reported. Amperometry in stirred solutions at a detection potential of +0.10 V provided a linear calibration plot for sucrose over the 1.2 × 10(-6)-3.0 × 10(-3) mol L(-1) concentration range, with a limit of detection of 3.6 × 10(-7) mol L(-1). The practical usefulness of the biosensor was demonstrated by determining sucrose in condensed milk and in an infant food reference material with good results. Additionally, the biosensor was implemented together with commercial fructose and glucose amperometric biosensors in a continuous flow system to perform the multiplexed quantification of sucrose, fructose and glucose in a single experiment. The operational characteristics of the biosensors in this novel flow system were evaluated and their applicability was demonstrated through the simultaneous determination of the three sugars in the above-mentioned reference material.

  18. Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

    PubMed Central

    Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

    2012-01-01

    Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

  19. Differential roles of alkaline/neutral invertases in Nostoc sp. PCC 7120: Inv-B isoform is essential for diazotrophic growth.

    PubMed

    Vargas, Walter A; Nishi, Carolina N; Giarrocco, Laura E; Salerno, Graciela L

    2011-01-01

    The presence of two alkaline/neutral invertases (Inv-A and Inv-B) in the filaments of Nostoc (also named Anabaena) sp. strain PCC 7120 and the involvement of sucrose metabolism in nitrogen fixation led us to investigate the physiological function of those isoforms in cells growing under different nitrogen sources. The highest expression level of each encoding gene was obtained in the presence of ammonium. These results were paralleled by polypeptide and enzyme activity level. In cells of N(2)-fixing filaments, localization of gene expression and subcellular enzyme activity assays demonstrated that invA gene (alr1521) expresses only in vegetative cells, whereas for invB (alr0819), expression is detected in both vegetative cells and heterocysts. In contrast to invA, when invB was knocked out, the filaments were unable to grow on diazotrophic conditions and the accumulation of sucrose and glycogen was altered. Our results demonstrate an essential role for Inv-B for diazotrophic growth and that Inv-B plays a key role in the coordination of sucrose and glycogen metabolism. We can also suggest that invB is likely to integrate the repertoire of genes regulated by a cyanobacterial transcription factor (NtcA) that plays a central role in global nitrogen control.

  20. Kinetics of the alkaline phosphatase catalyzed hydrolysis of disodium p-nitrophenyl phosphate in frozen model systems.

    PubMed

    Terefe, Netsanet Shiferaw; Mokwena, Kereilemang Khanah; Loey, Ann Van; Hendrickx, Marc E

    2002-01-01

    The alkaline phosphatase catalyzed hydrolysis of disodium-p-nitrophenyl phosphate was studied in four model systems comprising sucrose, maltodextrin, carboxymethylcellulose (CMC), and CMC-lactose in a temperature range of -28 to 20 degrees C. In the maltodextrin and CMC-lactose model systems, the reaction rate decreased to a very low value as the glass transition temperature was approached. In the CMC and CMC-lactose systems with low initial solute concentration, as a consequence of freeze-concentration, a rate maximum around the initial freezing temperature was observed. The Arrhenius equation described the temperature dependence of the reaction rate both in the liquid and the glassy states in all systems studied, while a slightly curved Arrhenius plot was observed in the "rubbery" state of the CMC and CMC-lactose systems. The WLF equation with system-dependent coefficients described the kinetics in the rubbery state of all the model systems except sucrose, excluding the short temperature range where reaction rate enhancement with decreasing temperature was observed.

  1. Role of sucrose in colonization of Streptococcus mutans in conventional Sprague-Dawley rats.

    PubMed

    Van Houte, J; Upeslacis, V N; Jordan, H V; Skobe, Z; Green, D B

    1976-01-01

    The role of sucrose in the colonization of S mutans strain 6715 in conventional Sprague-Dawley rats was studied. A diet with 56% sucrose favored the oral colonization of the test strain compared to diets with 56% glucose or fructose or to laboratory chow as determined by recoveries from extracted teeth ground in tissue grinders. S mutans strain 6715 cells became well established in all rats fed a high sucrose diet with cell inoculums ranging from 10(8) to the lowest effective dose of 10(5) CFU once orally administered; in rats on nonsucrose diets, inoculation with even the highest dose only infrequently resulted in the establishment of S mutans strain 6715. Sucrose- and glucose- grown cells appeared to behave similarly. Colonization of S mutans strain 6715 occurred in all rats fed diets with a sucrose content ranging from 56 to as low as 1%. The establishment of S mutans strain 6715 on the teeth of rats fed diets with a sucrose concentration of 0.1 or 0.01% was impaired and comparable to the diet containing 56% glucose. In rats fed a high glucose diet, uniform establishment and persistence of the test strain occurred after frequent inoculations with about 5 X 10(8) CFU. The colonization under these conditions appeared to be independent of the intestinal canal as a bacterial cell source. These data suggest the possibility that S mutans can establish itself in the human mouth in the absence of dietary sucrose. In rats fed a high glucose diet and inoculated with 10(7) CFU or less, the cells gradually disappeared from the teeth; in contrast, the test strain implanted well in rats fed the sucrose favors firmer attachment of initially weakly attached cells via in situ new glucan synthesis. S mutans strain 6715 also appeared to have some affinity for teeth in the absence of dietary sucrose that may be of ecological significance. Once firmly established in rats fed a high sucrose diet, S mutans strain 6715 maintained itself in high numbers on the teeth after a switch to a

  2. Effects of dietary amylase and sucrose on productivity of cows fed low-starch diets.

    PubMed

    Vargas-Rodriguez, C F; Engstrom, M; Azem, E; Bradford, B J

    2014-07-01

    Recent studies have observed positive effects of both sucrose and exogenous amylase on the productivity of dairy cattle. Our objective was to evaluate direct effects and interactions of amylase and sucrose on dry matter intake (DMI), milk production, and milk components. Forty-eight multiparous Holstein cows between 70 and 130 d in milk were randomly assigned to each of 4 pens (12 cows/pen). Pens were randomly assigned to treatment sequence in a 4 × 4 Latin square design, balanced for carryover effects. Treatment periods were 28 d, with 24 d for diet adaptation and 4d for sample and data collection. The treatments were a control diet (36% NDF and 21% starch), the control diet with amylase [0.5 g/kg of DM; Ronozyme RumiStar 600 (CT); DSM Nutritional Products Ltd., Basel, Switzerland], a diet with sucrose replacing corn grain at 2% of DM, and the sucrose diet with amylase (0.5 g/kg of DM). All data were analyzed with mixed models, including the fixed effects of sugar, amylase, and their interaction, and the random effects of period and pen. Milk data included the random effects of cow nested within pen and pen × period to provide the error term for the pen-level analysis. Dry matter intake was not affected by treatments. Milk yield and milk composition were not altered by the inclusion of sucrose or amylase; however, a tendency for an amylase × sucrose interaction was observed for milk protein content, reflecting slightly lower milk protein concentrations for amylase and sucrose treatments (3.00 and 2.99 ± 0.03%) compared with the control and amylase + sucrose treatments (3.02 and 3.03 ± 0.03%). Solids-corrected and fat-corrected milk yields were not significantly altered by treatment, although the direct effect of amylase approached significance for both variables, suggesting possible small increases with amylase supplementation (~0.5 kg/d). Feed efficiency (energy-corrected milk divided by dry matter intake) numerically increased with either amylase (1.57 ± 0

  3. Nucleus accumbens shell and core dopamine responsiveness to sucrose in rats: role of response contingency and discriminative/conditioned cues.

    PubMed

    Bassareo, V; Cucca, F; Musio, P; Lecca, D; Frau, R; Di Chiara, G

    2015-03-01

    This study investigated by microdialysis the role of response contingency and food-associated cues in the responsiveness of dopamine transmission in the nucleus accumbens shell and core to sucrose feeding. In naive rats, single-trial non-contingent presentation and feeding of sucrose pellets increased dialysate shell dopamine and induced full habituation of dopamine responsiveness to sucrose feeding 24 and 48 h later. In rats trained to respond for sucrose pellets on a fixed ratio 1 (FR1) schedule, dialysate dopamine increased in the shell but not in the core during active responding as well as under extinction in the presence of sucrose cues. In rats yoked to the operant rats, the presentation of sucrose cues also increased dialysate dopamine selectively in the shell. In contrast, non-contingent sucrose presentation and feeding in FR1-trained and in yoked rats increased dialysate dopamine to a similar extent in the shell and core. It is concluded that, whereas non-contingent sucrose feeding activated dopamine transmission in the shell and core, response-contingent feeding activated, without habituation, dopamine transmission selectively in the shell as a result of the action of sucrose conditioned cues. These observations are consistent with a critical role of conditioned cues acquired during training and differential activation of shell vs. core dopamine for response-contingent sucrose feeding.

  4. Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels

    PubMed Central

    Anton, Stephen D.; Martin, Corby K.; Han, Hongmei; Coulon, Sandra; Cefalu, William T.; Geiselman, Paula; Williamson, Donald A.

    2010-01-01

    Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low-calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. Design: 19 healthy lean (BMI = 20.0 – 24.9) and 12 obese (BMI = 30.0 – 39.9) individuals 18 to 50 years old completed three separate food test days during which they received preloads containing stevia (290 kcal), aspartame (290 kcal), or sucrose (493 kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20 minutes after the lunch preload. Despite the caloric difference in preloads (290 vs. 493 kcals), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia = 301 kcal, p < .01; aspartame = 330 kcal, p < .01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly lowered postprandial glucose levels compared to sucrose preloads (p < .01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p < .05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload. PMID:20303371

  5. Metabolic engineering of Ralstonia eutropha for the production of polyhydroxyalkanoates from sucrose.

    PubMed

    Park, Si Jae; Jang, Young-Ah; Noh, Won; Oh, Young Hoon; Lee, Hyuk; David, Yokimiko; Baylon, Mary Grace; Shin, Jihoon; Yang, Jung Eun; Choi, So Young; Lee, Seung Hwan; Lee, Sang Yup

    2015-03-01

    A sucrose utilization pathway was established in Ralstonia eutropha NCIMB11599 and R. eutropha 437-540 by introducing the Mannheimia succiniciproducens MBEL55E sacC gene that encodes β-fructofuranosidase. These engineered strains were examined for the production of poly(3-hydroxybutyrate) [P(3HB)] and poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)], respectively, from sucrose as a carbon source. It was found that β-fructofuranosidase excreted into the culture medium could hydrolyze sucrose to glucose and fructose, which were efficiently used as carbon sources by recombinant R. eutropha strains. When R. eutropha NCIMB11599 expressing the sacC gene was cultured in nitrogen-free chemically defined medium containing 20 g/L of sucrose, a high P(3HB) content of 73.2 wt% could be obtained. In addition, R. eutropha 437-540 expressing the Pseudomonas sp. MBEL 6-19 phaC1437 gene and the Clostridium propionicum pct540 gene accumulated P(3HB-co-21.5 mol% LA) to a polymer content of 19.5 wt% from sucrose by the expression of the sacC gene and the Escherichia coli ldhA gene. The molecular weights of P(3HB) and P(3HB-co-21.5 mol%LA) synthesized in R. eutropha using sucrose as a carbon source were 3.52 × 10(5) (Mn ) and 2.19 × 10(4) (Mn ), respectively. The engineered R. eutropha strains reported here will be useful for the production of polyhydroxyalkanoates (PHAs) from sucrose, one of the most abundant and relatively inexpensive carbon sources.

  6. Differences in bingeing behavior and cocaine reward following intermittent access to sucrose, glucose or fructose solutions.

    PubMed

    Rorabaugh, J M; Stratford, J M; Zahniser, N R

    2015-08-20

    Daily intermittent access to sugar solutions results in intense bouts of sugar intake (i.e. bingeing) in rats. Bingeing on sucrose, a disaccharide of glucose and fructose, has been associated with a "primed" mesolimbic dopamine (DA) pathway. Recent studies suggest glucose and fructose engage brain reward and energy-sensing mechanisms in opposing ways and may drive sucrose intake through unique neuronal circuits. Here, we examined in male Sprague-Dawley rats whether or not (1) intermittent access to isocaloric solutions of sucrose, glucose or fructose results in distinctive sugar-bingeing profiles and (2) previous sugar bingeing alters cocaine locomotor activation and/or reward, as determined by conditioned place preference (CPP). To encourage bingeing, rats were given 24-h access to water and 12-h-intermittent access to chow plus an intermittent bottle that contained water (control) or 8% solutions of sucrose, glucose or fructose for 9days, followed by ad libitum chow diet and a 10-day cocaine (15mg/kg; i.p.) CPP paradigm. By day 4 of the sugar-bingeing diet, sugar bingeing in the fructose group surpassed the glucose group, with the sucrose group being intermediate. All three sugar groups had similar chow and water intake throughout the diet. In contrast, controls exhibited chow bingeing by day 5 without altering water intake. Similar magnitudes of cocaine CPP were observed in rats with a history of sucrose, fructose or chow (control) bingeing. Notably, the glucose-bingeing rats did not demonstrate a significant cocaine CPP despite showing similar cocaine-induced locomotor activity as the other diet groups. Overall, these results show that fructose and glucose, the monosaccharide components of sucrose, produce divergent degrees of bingeing and cocaine reward.

  7. Differences in bingeing behavior and cocaine reward following intermittent access to sucrose, glucose or fructose solutions

    PubMed Central

    Rorabaugh, Jacki M.; Stratford, Jennifer M.; Zahniser, Nancy R.

    2015-01-01

    Daily intermittent access to sugar solutions results in intense bouts of sugar intake (i.e. bingeing) in rats. Bingeing on sucrose, a disaccharide of glucose and fructose, has been associated with a “primed” mesolimbic dopamine (DA) pathway. Recent studies suggest glucose and fructose engage brain reward and energy sensing mechanisms in opposing ways and may drive sucrose intake through unique neuronal circuits. Here, we examined in male Sprague-Dawley rats whether or not (1) intermittent access to isocaloric solutions of sucrose, glucose or fructose results in distinctive sugar bingeing profiles and (2) previous sugar bingeing alters cocaine locomotor activation and/or reward, as determined by conditioned place preference (CPP). To encourage bingeing, rats were given 24-h access to water and 12 h-intermittent access to chow plus an intermittent bottle that contained water (control) or 8% solutions of sucrose, glucose or fructose for 9 days, followed by ad libitum chow diet and a 10 day cocaine (15 mg/kg; i.p.) CPP paradigm. By day 4 of the sugar bingeing diet, sugar bingeing in the fructose group surpassed the glucose group, with the sucrose group being intermediate. All three sugar groups had similar chow and water intake throughout the diet. In contrast, controls exhibited chow bingeing by day 5 without altering water intake. Similar magnitudes of cocaine CPP were observed in rats with a history of sucrose, fructose or chow (control) bingeing. Notably, the glucosebingeing rats did not demonstrate a significant cocaine CPP despite showing similar cocaine-induced locomotor activity as the other diet groups. Overall, these results show that fructose and glucose, the monosaccharide components of sucrose, produce divergent degrees of bingeing and cocaine reward. PMID:26079112

  8. A zinc finger protein from Candida albicans is involved in sucrose utilization.

    PubMed Central

    Kelly, R; Kwon-Chung, K J

    1992-01-01

    A sucrose-inducible alpha-glucosidase activity that hydrolyzes sucrose in Candida albicans has been demonstrated previously. The enzyme is assayable in whole cells and was inhibited by both sucrose and maltose. A C. albicans gene (CASUC1) that affects sucrose utilization and alpha-glucosidase activity was cloned by expression in a Saccharomyces cerevisiae suc2 mutant (2102) devoid of invertase genes. CASUC1 enabled the S. cerevisiae mutant to utilize both sucrose and maltose. DNA sequence analysis revealed that CASUC1 encodes a putative zinc finger-containing protein with 28% identity to a maltose-regulatory gene (MAL63) of S. cerevisiae. The gene products of CASUC1 and MAL63 are approximately the same size (501 and 470 amino acids, respectively), and each contains a single zinc finger located at the N terminus. The zinc fingers of CASUC1 and MAL63 comprise six conserved cysteines (C6 zinc finger) and are of the general form Cys-Xaa2-Cys-Xaa6-Cys-Xaavariable-Cys-Xaa2-Cys-+ ++Xaa6-Cys (where Xaan indicates a stretch of the indicated number of any amino acids). Both contain five amino acids in the variable region. CASUC1 also complemented the maltose utilization defect of an S. cerevisiae mutant (TCY-137) containing a defined mutation in a maltose-regulatory gene. The sucrose utilization defect of type II Candida stellatoidea, a sucrase-negative mutant of C. albicans, was corrected by CASUC1. Determinations of alpha-glucosidase activity in whole cells revealed that activity was restored in transformants cultivated on either sucrose or maltose. To our knowledge, this is the first zinc finger-encoding gene, as well as the first putative regulatory gene, to be identified in C. albicans. Images PMID:1729210

  9. Glucose and sucrose differentially modify cell proliferation in maize during germination.

    PubMed

    Lara-Núñez, Aurora; García-Ayala, Brendy B; Garza-Aguilar, Sara M; Flores-Sánchez, Jesús; Sánchez-Camargo, Victor A; Bravo-Alberto, Carlos E; Vázquez-Santana, Sonia; Vázquez-Ramos, Jorge M

    2017-04-01

    Glucose and sucrose play a dual role: as carbon and energy sources and as signaling molecules. In order to address the impact that sugars may have on maize seeds during germination, embryo axes were incubated with or without either of the two sugars. Expression of key cell cycle markers and protein abundance, cell patterning and de novo DNA synthesis in root meristem zones were analyzed. Embryo axes without added sugars in imbibition medium were unable to grow after 7 days; in sucrose, embryo axes developed seminal and primary roots with numerous root hairs, whereas in glucose axes showed a twisted morphology, no root hair formation but callus-like structures on adventitious and primary seminal roots. More and smaller cells were observed with glucose treatment in root apical meristems. de novo DNA synthesis was stimulated more by glucose than by sucrose. At 24 h of imbibition, expression of ZmCycD2;2a and ZmCycD4;2 was increased by sucrose and reduced by glucose. CDKA1;1 and CDKA2;1 expression was stimulated equally by both sugars. Protein abundance patterns were modified by sugars: ZmCycD2 showed peaks on glucose at 12 and 36 h of imbibition whereas sucrose promoted ZmCycD3 protein accumulation. In presence of glucose ZmCycD3, ZmCycD4 and ZmCycD6 protein abundance was reduced after 24 h. Finally, both sugars stimulated ZmCDKA protein accumulation but at different times. Overall, even though glucose appears to act as a stronger mitogen stimulator, sucrose stimulated the expression of more cell cycle markers during germination. This work provides evidence of a differential response of cell cycle markers to sucrose and glucose during maize germination that may affect the developmental program during plantlet establishment.

  10. Efficacy and safety of intravenous iron sucrose in treating adults with iron deficiency anemia

    PubMed Central

    Cançado, Rodolfo Delfini; de Figueiredo, Pedro Otavio Novis; Olivato, Maria Cristina Albe; Chiattone, Carlos Sérgio

    2011-01-01

    Background Iron deficiency is the most common disorder in the world, affecting approximately 25% of the world`s population and the most common cause of anemia. Objective To evaluate the efficacy and safety of intravenous iron sucrose (IS) in the treatment of adults with iron deficiency anemia Methods Eighty-six adult patients with iron deficiency anemia, who had intolerance or showed no effect with oral iron therapy, received a weekly dose of 200 mg of intravenous iron sucrose until the hemoglobin level was corrected or until receiving the total dose of intravenous iron calculated for each patient Results The mean hemoglobin and serum ferritin levels were 8.54 g/dL and 7.63 ng/mL (pre-treatment) and 12.1 g/dL and 99.0 ng/mL (post-treatment) (p-value < 0.0001), respectively. The average increases in hemoglobin levels were 3.29 g/dL for women and 4.58 g/dL for men; 94% of male and 84% of female patients responded (hemoglobin increased by at least 2 g/dL) to intravenous iron therapy. Correction of anemia was obtained in 47 of 69 (68.1%) female patients and in 12 of 17 male (70.6%) patients. A total of 515 intravenous infusions of iron sucrose were administered and iron sucrose was generally well tolerated with no moderate or serious adverse drug reactions recorded by the investigators. Conclusions Our data confirm that the use of intravenous iron sucrose is a safe and effective option in the treatment of adult patients with iron deficiency anemia who lack satisfactory response to oral iron therapy. Intravenous iron sucrose is well tolerated and with a clinically manageable safety profile when using appropriate dosing and monitoring. The availability of intravenous iron sucrose would potentially improve compliance and thereby reduce morbidities from iron deficiency. PMID:23049360

  11. Analgesic effects of oral sucrose and pacifier during eye examinations for retinopathy of prematurity.

    PubMed

    Mitchell, Anita; Stevens, Bonnie; Mungan, Nils; Johnson, William; Lobert, Sharon; Boss, Barbara

    2004-12-01

    Oral sucrose reduces pain during heel sticks and venipunctures in preterm infants, but no studies have been done to determine the effectiveness of sucrose during eye examinations for retinopathy of prematurity. Therefore, the purpose of this study was to determine the effectiveness of local anesthetic eye drops and a pacifier, plus repeated doses of 24% sucrose, to relieve pain associated with eye examinations for retinopathy of prematurity. In this double-blind randomized controlled trial, 30 preterm infants were randomly assigned to one of two treatments, in which they received either local anesthetic eye drops, a pacifier, plus three doses of sterile water or local anesthetic eye drops, a pacifier, plus three doses of 24% sucrose during the eye examination. Treatment effectiveness was determined using a validated infant pain measure, the Premature Infant Pain Profile (PIPP), which includes measures of facial expressions, heart rate, and oxygen saturation and takes behavioral state and gestational age into consideration. Data were collected before, during, and following an examination of the left eye. Statistically significant differences in mean PIPP scores were found between the sucrose and water groups during the left eye examination. The mean PIPP score was 8.8 for the sucrose group and 11.4 for the water group ( t = 2.87, p = .008 two-tailed). No significant differences were found in PIPP scores immediately following the procedure. Sucrose and a pacifier may be beneficial for minimizing pain during eye examinations in preterm infants and should be considered as a part of evidence-based guidelines for relieving pain during this procedure.

  12. Low density, resorcinol-formaldehyde aerogels

    DOEpatents

    Pekala, Richard W.

    1991-01-01

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "Clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density.ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100.circle.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  13. Low density, resorcinol-formaldehyde aerogels

    DOEpatents

    Pekala, Richard W.

    1989-01-01

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer "clusters". The covalent crosslinking of these "clusters" produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density .ltoreq.100 mg/cc; cell size .ltoreq.0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 .ANG.. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  14. Low density, resorcinol-formaldehyde aerogels

    DOEpatents

    Pekala, R.W.

    1989-10-10

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer clusters. The covalent crosslinking of these clusters produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density [<=]100 mg/cc; cell size [<=]0.1 microns). The aerogels are transparent, dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 [angstrom]. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron.

  15. Low density, resorcinol-formaldehyde aerogels

    DOEpatents

    Pekala, R.W.

    1988-05-26

    The polycondensation of resorcinol with formaldehyde under alkaline conditions results in the formation of surface functionalized polymer ''clusters''. The covalent crosslinking of these ''clusters'' produces gels which when processed under supercritical conditions, produce low density, organic aerogels (density less than or equal to100 mg/cc; cell size less than or equal to0.1 microns). The aerogels are transparent,dark red in color and consist of interconnected colloidal-like particles with diameters of about 100 A/degree/. These aerogels may be further carbonized to form low density carbon foams with cell size of about 0.1 micron. 1 fig., 1 tab.

  16. Desialylated alkaline phosphatase: activation by 4-nitrophenol.

    PubMed

    Nayudu, P R

    1984-01-01

    Mouse ileal alkaline phosphatase is a sialyl enzyme (12-14 moles per mole of enzyme). When partially desialylated by treatment with neuraminidase, the enzyme loses most of its activity, associated with reduced apparent Vmax and Km. Part of that loss, however, is recovered as the product 4-nitrophenol's concentration builds up in the cuvette. Experimental results are presented to demonstrate that the activation is due to the binding of 4-nitrophenol as a ligand by the partially desialylated enzyme and that both the loss of activity by sialic acid removal and activation by ligand-binding are correlated with changes in protein conformation.

  17. Partially flexible MEMS neural probe composed of polyimide and sucrose gel for reducing brain damage during and after implantation

    NASA Astrophysics Data System (ADS)

    Jeon, Myounggun; Cho, Jeiwon; Kim, Yun Kyung; Jung, Dahee; Yoon, Eui-Sung; Shin, Sehyun; Cho, Il-Joo

    2014-02-01

    This paper presents a flexible microelectromechanical systems (MEMS) neural probe that minimizes neuron damage and immune response, suitable for chronic recording applications. MEMS neural probes with various features such as high electrode densities have been actively investigated for neuron stimulation and recording to study brain functions. However, successful recording of neural signals in chronic application using rigid silicon probes still remains challenging because of cell death and macrophages accumulated around the electrodes over time from continuous brain movement. Thus, in this paper, we propose a new flexible MEMS neural probe that consists of two segments: a polyimide-based, flexible segment for connection and a rigid segment composed of thin silicon for insertion. While the flexible connection segment is designed to reduce the long-term chronic neuron damage, the thin insertion segment is designed to minimize the brain damage during the insertion process. The proposed flexible neural probe was successfully fabricated using the MEMS process on a silicon on insulator wafer. For a successful insertion, a biodegradable sucrose gel is coated on the flexible segment to temporarily increase the probe stiffness to prevent buckling. After the insertion, the sucrose gel dissolves inside the brain exposing the polyimide probe. By performing an insertion test, we confirm that the flexible probe has enough stiffness. In addition, by monitoring immune responses and brain histology, we successfully demonstrate that the proposed flexible neural probe incurs fivefold less neural damage than that incurred by a conventional silicon neural probe. Therefore, the presented flexible neural probe is a promising candidate for recording stable neural signals for long-time chronic applications.

  18. Effectiveness of oral sucrose and simulated rocking on pain response in preterm neonates.

    PubMed

    Johnston, C C; Stremler, R L; Stevens, B J; Horton, L J

    1997-08-01

    Feeding and carrying have been interventions used by caregivers throughout history in relieving distress in infants. Recent studies on the food substance sucrose have elucidated the comforting effect of the taste component of feeding while studies of rocking have examined the comforting effect of the vestibular component of carrying. The purpose of this study was to determine the effectiveness of sucrose and simulated rocking alone and in combination on diminishing pain response in preterm neonates undergoing routine heelstick procedure in the neonatal intensive care unit (NICU). Preterm infants (n = 85) between 25-34 weeks post-conceptual age (PCA) and 2-10 days postnatal age (PNA) were randomly assigned to one of four conditions for routine heelstick procedure. The conditions were (1) sucrose alone: 0.05 ml of 24% sucrose was placed on the anterior surface of the tongue just prior to the lancing of the heel; (2) simulated rocking alone: 15 min prior to and during the heelstick procedure, the infant was swaddled and put on an oscillating mattress; (3) combination of sucrose and simulated rocking; and (4) placebo: 0.05 ml sterile water administered just prior to heelstick. Physiological (heart rate) and behavioural (facial actions) responses from baseline across 90 s following heelstick were scored second-to-second. Facial actions were analysed with repeated measures MANCOVA and heart rate with repeated measures ANCOVA. Behavioural state and gestational age were covariates. The groups that received sucrose alone or in combination with simulated rocking showed less facial actions indicative of pain than the rocking alone or control group. The addition of rocking to the sucrose condition tended to further blunt the facial expression of pain, but this enhancement did not reach a significant level. Heart rate was not decreased by any intervention compared to the control condition. Although the simulated rocking did promote quiet sleep, which has been reported in

  19. Alkaline chemistry of transuranium elements and technetium and the treatment of alkaline radioactive wastes

    SciTech Connect

    Delegard, C.H.; Peretrukhin, V.F.; Shilov, V.P.; Pikaev, A.K.

    1995-05-01

    Goal of this survey is to generalize the known data on fundamental physical-chemical properties of TRUs and Tc, methods for their isolation, and to provide recommendations that will be useful for partitioning them from alkaline high-level wastes.

  20. Iron sucrose accelerates early atherogenesis by increasing superoxide production and upregulating adhesion molecules in CKD.

    PubMed

    Kuo, Ko-Lin; Hung, Szu-Chun; Lee, Tzong-Shyuan; Tarng, Der-Cherng

    2014-11-01

    High-dose intravenous iron supplementation is associated with adverse cardiovascular outcomes in patients with CKD, but the underlying mechanism is unknown. Our study investigated the causative role of iron sucrose in leukocyte-endothelium interactions, an index of early atherogenesis, and subsequent atherosclerosis in the mouse remnant kidney model. We found that expression levels of intracellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and adhesion of U937 cells increased in iron-treated human aortic endothelial cells through upregulated NADPH oxidase (NOx) and NF-κB signaling. We then measured mononuclear-endothelial adhesion and atherosclerotic lesions of the proximal aorta in male C57BL/6 mice with subtotal nephrectomy, male apolipoprotein E-deficient (ApoE(-/-)) mice with uninephrectomy, and sham-operated mice subjected to saline or parenteral iron loading. Iron sucrose significantly increased tissue superoxide production, expression of tissue cell adhesion molecules, and endothelial adhesiveness in mice with subtotal nephrectomy. Moreover, iron sucrose exacerbated atherosclerosis in the aorta of ApoE(-/-) mice with uninephrectomy. In patients with CKD, intravenous iron sucrose increased circulating mononuclear superoxide production, expression of soluble adhesion molecules, and mononuclear-endothelial adhesion compared with healthy subjects or untreated patients. In summary, iron sucrose aggravated endothelial dysfunction through NOx/NF-κB/CAM signaling, increased mononuclear-endothelial adhesion, and exacerbated atherosclerosis in mice with remnant kidneys. These results suggest a novel causative role for therapeutic iron in cardiovascular complications in patients with CKD.

  1. Impact of adolescent sucrose access on cognitive control, recognition memory, and parvalbumin immunoreactivity.

    PubMed

    Reichelt, Amy C; Killcross, Simon; Hambly, Luke D; Morris, Margaret J; Westbrook, R Fred

    2015-04-01

    In this study we sought to determine the effect of daily sucrose consumption in young rats on their subsequent performance in tasks that involve the prefrontal cortex and hippocampus. High levels of sugar consumption have been associated with the development of obesity, however less is known about how sugar consumption influences behavioral control and high-order cognitive processes. Of particular concern is the fact that sugar intake is greatest in adolescence, an important neurodevelopmental period. We provided sucrose to rats when they were progressing through puberty and adolescence. Cognitive performance was assessed in adulthood on a task related to executive function, a rodent analog of the Stroop task. We found that sucrose-exposed rats failed to show context-appropriate responding during incongruent stimulus compounds presented at test, indicative of impairments in prefrontal cortex function. Sucrose exposed rats also showed deficits in an on object-in-place recognition memory task, indicating that both prefrontal and hippocampal function was impaired. Analysis of brains showed a reduction in expression of parvalbumin-immunoreactive GABAergic interneurons in the hippocampus and prefrontal cortex, indicating that sucrose consumption during adolescence induced long-term pathology, potentially underpinning the cognitive deficits observed. These results suggest that consumption of high levels of sugar-sweetened beverages by adolescents may also impair neurocognitive functions affecting decision-making and memory, potentially rendering them at risk for developing mental health disorders.

  2. Electrical stimulation of the lateral habenula produces an inhibitory effect on sucrose self-administration.

    PubMed

    Friedman, Alexander; Lax, Elad; Dikshtein, Yahav; Abraham, Lital; Flaumenhaft, Yakov; Sudai, Einav; Ben-Tzion, Moshe; Yadid, Gal

    2011-01-01

    The lateral habenula (LHb) plays a role in prediction of negative reinforcement, punishment and aversive responses. In the current study, we examined the role that the LHb plays in regulation of negative reward responses and aversion. First, we tested the effect of intervention in LHb activity on sucrose reinforcing behavior. An electrode was implanted into the LHb and rats were trained to self-administer sucrose (20%; 16 days) until at least three days of stable performance were achieved (as represented by the number of active lever presses in self-administration cages). Rats subsequently received deep brain stimulation (DBS) of the LHb, which significantly reduced sucrose self-administration levels. In contrast, lesion of the LHb increased sucrose-seeking behavior, as demonstrated by a delayed extinction response to substitution of sucrose with water. Furthermore, in a modified non-rewarding conditioned-place-preference paradigm, DBS of the LHb led to aversion to the context associated with stimulation of this brain region. We postulate that electrical stimulation of the LHb attenuates positive reward-associated reinforcement by natural substances.

  3. Sucrose malabsorption in children: noninvasive diagnosis by interval breath hydrogen determination.

    PubMed

    Perman, J A; Barr, R G; Watkins, J B

    1978-07-01

    To assess whether malabsorption of specific sugars is easily detected in a pediatric population by interval measurement of breath hydrogen excretion, hydrogen concentration was determined following administration of oral sucrose to six sucrose-intolerant children with congenital sucrase-isomaltase deficiency and in 16 sucrose-tolerant control subjects. Breath samples were collected by means of a newly devised nasal prong technique not requiring active patient cooperation and suitable for use in all age groups. Breath hydrogen concentrations obtained by samples collected by this method correlated highly (r = 0.94) with the previously validated modified Haldane-Priestley tube method for sampling alveolar air. Identification of sucrose-intolerant individuals was achieved on the basis of hydrogen excretion: peak values, expressed as parts per million above baseline (deltappm), equalled 114 +/- 63 (mean +/- SD) versus 2.4 +/- 3.6 deltappm in control subjects (P = 0.007). Best discrimination between the groups occurred at 90 minutes postingestion. The findings validate this simple method for collection of expired air and demonstrate that breath hydrogen determination permits the noninvasive detection of sucrose malabsorption in children.

  4. Antisense repression of sucrose phosphate synthase in transgenic muskmelon alters plant growth and fruit development

    SciTech Connect

    Tian, Hongmei; Ma, Leyuan; Zhao, Cong; Hao, Hui; Gong, Biao; Yu, Xiyan; Wang, Xiufeng

    2010-03-12

    To unravel the roles of sucrose phosphate synthase (SPS) in muskmelon (Cucumis melo L.), we reduced its activity in transgenic muskmelon plants by an antisense approach. For this purpose, an 830 bp cDNA fragment of muskmelon sucrose phosphate synthase was expressed in antisense orientation behind the 35S promoter of the cauliflower mosaic virus. The phenotype of the antisense plants clearly differed from that of control plants. The transgenic plant leaves were markedly smaller, and the plant height and stem diameter were obviously shorter and thinner. Transmission electron microscope observation revealed that the membrane degradation of chloroplast happened in transgenic leaves and the numbers of grana and grana lamella in the chloroplast were significantly less, suggesting that the slow growth and weaker phenotype of transgenic plants may be due to the damage of the chloroplast ultrastructure, which in turn results in the decrease of the net photosynthetic rate. The sucrose concentration and levels of sucrose phosphate synthase decreased in transgenic mature fruit, and the fruit size was smaller than the control fruit. Together, our results suggest that sucrose phosphate synthase may play an important role in regulating the muskmelon plant growth and fruit development.

  5. Activation of physiological stress responses by a natural reward: Novel vs. repeated sucrose intake.

    PubMed

    Egan, Ann E; Ulrich-Lai, Yvonne M

    2015-10-15

    Pharmacological rewards, such as drugs of abuse, evoke physiological stress responses, including increased heart rate and blood pressure, and activation of the hypothalamic-pituitary-adrenal (HPA) axis. It is not clear to what extent the natural reward of palatable foods elicits similar physiological responses. In order to address this question, HPA axis hormones, heart rate, blood pressure and brain pCREB immunolabeling were assessed following novel and repeated sucrose exposure. Briefly, adult, male rats with ad libitum food and water were given either a single (day 1) or repeated (twice-daily for 14 days) brief (up to 30 min) exposure to a second drink bottle containing 4 ml of 30% sucrose drink vs. water (as a control for bottle presentation). Sucrose-fed rats drank more than water-fed on all days of exposure, as expected. On day 1 of exposure, heart rate, blood pressure, plasma corticosterone, and locomotion were markedly increased by presentation of the second drink bottle regardless of drink type. After repeated exposure (day 14), these responses habituated to similar extents regardless of drink type and pCREB immunolabeling in the hypothalamic paraventricular nucleus (PVN) also did not vary with drink type, whereas basolateral amygdala pCREB was increased by sucrose intake. Taken together, these data suggest that while sucrose is highly palatable, physiological stress responses were evoked principally by the drink presentation itself (e.g., an unfamiliar intervention by the investigators), as opposed to the palatability of the offered drink.

  6. Quick freezing of one-cell mouse embryos using ethylene glycol with sucrose.

    PubMed

    Rayos, A A; Takahashi, Y; Hishinuma, M; Kanagawa, H

    1992-03-01

    One-cell mouse embryos were frozen by direct plunging into liquid nitrogen (LN(2)) vapor after equilibration in 3 M ethylene glycol with 0.25 M sucrose (freezing medium) for 5 to 40 minutes. After thawing, the embryos were cultured in vitro and the effects of the equilibration period and dilution method were examined. No significant difference was observed in the in vitro survival of embryos when 0.5 or 1.0 M sucrose was used for the dilution of the cryoprotectant for each equilibration period. The highest survival rate (67.2%) was obtained when the embryos were equilibrated for 10 minutes, and the cryoprotectant diluted with either 0.5 or 1.0 M sucrose after thawing. Shorter (5 minutes) or prolonged (40 minutes) equilibration of embryos in the freezing medium yielded significantly lower survival rates. Dilution by direct transfer of the frozen-thawed embryos into PB1 resulted in lower survival rates than when 0.5 or 1.0 M sucrose was used. The in vitro development to the blastocyst stage of one-cell mouse embryos frozen after 10 minutes equilibration in the freezing medium and diluted after thawing in 0.5 M sucrose was significantly lower than the control (68.0 vs 92.7%). However, transfer of the blastocysts developing from frozen-thawed one-cell mouse embryos into the uterine horns of the recipients resulted in fetal development and implantation rates similar to the control.

  7. Apple pectin affects the efficacy of epigallocatechin gallate on oral sucrose tolerance test in adult mice.

    PubMed

    Tamura, M; Hori, S

    2011-11-01

    Epigallocatechin gallate (EGCg), a dietary polyphenol and a major tea catechin, is a known sucrase inhibitor. Since dietary pectin is known to modulate some of the functions of the gastrointestinal tract, we investigated whether it could specifically affect the efficacy of EGCg on an oral sucrose tolerance test in mice. Male Crj:CD-1 (ICR) mice (seven weeks old) were randomly divided into two groups and fed a 5 % apple pectin (PE) or 5 % cellulose (CE) diet (control diet) for 28 days. After the experimental diet period, all mice were fasted overnight. A volume of 0.2 mL EGCg (20 mg/mL) was orally administered to all the mice by stainless steel feeding needle via injection syringe and a sucrose tolerance test was performed. The blood glucose levels were measured in blood collected from the tail vein using the OneTouch® Ultra® blood glucose monitoring system. Blood glucose levels at 30 minutes and 60 minutes after sucrose loading in the PE group were significantly higher than initial blood glucose levels. However, blood glucose levels at 30 minutes, 60 minutes, and 120 minutes after sucrose loading in the CE group were not significantly higher than initial blood glucose levels. After laparotomy, plasma lipids were also measured. Plasma triglyceride concentrations were significantly greater in the PE group than in the CE (control) group. This demonstrates that dietary pectin can affect the efficacy of EGCg on the oral sucrose tolerance test in mice.

  8. Dynamic studies of proton diffusion in mesoscopic heterogeneous matrix: I. Concentrated solutions of sucrose.

    PubMed

    Gutman, M; Nachliel, E; Kiryati, S

    1992-07-01

    Biochemical systems lose their homogeneity at a mesoscopic scale; physical parameters vary sharply over a scale of a few nanometers.In this manuscript, we demonstrate how proton diffusion studies can report the microscopic properties of inhomogeneous systems.The method used for this purpose was the laser induced proton pulse and the reaction followed was the recombination of a proton with pyranine anion (8 hydroxy pyrene 1,3,6 trisulfonate) either in the excited state (subnanosecond dynamics) or in the ground state (microsecond time-scale measurements). The observed signals were analyzed by numeric integration of differential rate equations pertinent to the diffusion controlled reaction between proton and pyranine anion.The accuracy of the methodology was verified by measuring the dielectric constant of sucrose solutions. The results we obtained are identical with those published in the International Critical Tables (1933. Vol. VI, 82-101).The diffusion coefficient of proton was found to be independent of the sucrose concentration, up to 2M solution where the sucrose makes up 45% of the volume. This observation is interpreted in terms of the microscopic heterogeneity of the solution: the proton diffuses in the aqueous space between the sucrose molecules, while the continuity of the aqueous phase is maintained by the Brownian motion of the sucrose molecule, which allows the proton to pass between them at an unhindered rate.

  9. Postpartum depression in rats: differences in swim test immobility, sucrose preference and nurturing behaviors.

    PubMed

    Fernandez, Jamie Winderbaum; Grizzell, J Alex; Philpot, Rex M; Wecker, Lynn

    2014-10-01

    Postpartum depression (PPD) is a common disorder affecting both mothers and their offspring. Studies of PPD in laboratory animals have typically assessed either immobility on forced swim testing or sucrose preference in ovariectomized rats following hormone supplementation and withdrawal or in stress models. To date, few studies have related these measures to maternal behaviors, a potential indicator of depressive-like activity postpartum. Because a single measure may be insufficient to characterize depression, the present study determined the distribution of depressive-like behaviors in Sprague-Dawley rats postpartum. Nurturing and non-nurturing behaviors exhibited by undisturbed dams were recorded during the first 12 days postpartum, and immobility in the forced swim test and sucrose preference were determined thereafter. A median-split analysis indicated that 19% of dams exhibited high sucrose preference and low immobility, 30% exhibited either only high immobility or only low sucrose preference, and 21% exhibited both high immobility and low preference. Dams exhibiting depressive-like activity on either or both tests displayed increased self-directed behaviors and decreased active nurturing during the dark phase of the diurnal cycle. This is the first study to characterize undisturbed nurturing and non-nurturing behaviors, and use both sucrose preference and immobility in the forced swim test, to classify PPD endophenotypes exhibited by rat dams following parturition. The present study underscores the idea that multiple tests should be used to characterize depressive-like behavior, which is highly heterogeneous in both the human and laboratory animal populations.

  10. Efficient production of pullulan by Aureobasidium pullulans grown on mixtures of potato starch hydrolysate and sucrose.

    PubMed

    An, Chao; Ma, Sai-Jian; Chang, Fan; Xue, Wen-Jiao

    Pullulan is a natural exopolysaccharide with many useful characteristics. However, pullulan is more costly than other exopolysaccharides, which limits its effective application. The purpose of this study was to adopt a novel mixed-sugar strategy for maximizing pullulan production, mainly using potato starch hydrolysate as a low-cost substrate for liquid-state fermentation by Aureobasidium pullulans. Based on fermentation kinetics evaluation of pullulan production by A. pullulans 201253, the pullulan production rate of A. pullulans with mixtures of potato starch hydrolysate and sucrose (potato starch hydrolysate:sucrose=80:20) was 0.212h(-1), which was significantly higher than those of potato starch hydrolysate alone (0.146h(-1)) and mixtures of potato starch hydrolysate, glucose, and fructose (potato starch hydrolysate:glucose:fructose=80:10:10, 0.166h(-1)) with 100gL(-1) total carbon source. The results suggest that mixtures of potato starch hydrolysate and sucrose could promote pullulan synthesis and possibly that a small amount of sucrose stimulated the enzyme responsible for pullulan synthesis and promoted effective potato starch hydrolysate conversion effectively. Thus, mixed sugars in potato starch hydrolysate and sucrose fermentation might be a promising alternative for the economical production of pullulan.

  11. Memory enhancement produced by post-training exposure to sucrose-conditioned cues

    PubMed Central

    Holahan, Matthew R

    2013-01-01

    A number of aversive and appetitive unconditioned stimuli (such as shock and food) are known to produce memory enhancement when they occur during the post-training period. Post-training exposure to conditioned aversive stimuli has also been shown to enhance memory consolidation processes. The present study shows for the first time that post-training exposure to conditioned stimuli previously paired with consumption of a sucrose solution also enhances memory consolidation. Male Long Evans rats were trained on a one-session conditioned cue preference (CCP) task on a radial arm maze. Immediately or 2 hours after training, rats consumed a sucrose solution or were exposed to cues previously paired with consumption of sucrose or cues previously paired with water. Twenty-four hours later, the rats were tested for a CCP. Immediate, but not delayed, post-training consumption of sucrose enhanced memory for the CCP. Immediate, but not delayed, post-training exposure to cues previously paired with sucrose, but not with water, also enhanced CCP memory. The possibility that rewarding and aversive conditioned stimuli affect memory by a common physiological process is discussed. PMID:24358865

  12. Electrospun gelatin nanofibers: a facile cross-linking approach using oxidized sucrose.

    PubMed

    Jalaja, K; James, Nirmala R

    2015-02-01

    Gelatin nanofibers were fabricated via electrospinning with minimal toxicity from solvents and cross-linking agents. Electrospinning was carried out using a solvent system based on water and acetic acid (8:2, v/v). Acetic acid concentration was kept as minimum as possible to reduce the toxic effects. Electrospun gelatin nanofibers were cross-linked with oxidized sucrose. Sucrose was oxidized by periodate oxidation to introduce aldehyde functionality. Cross-linking with oxidized sucrose could be achieved without compromising the nanofibrous architecture. Cross-linked gelatin nanofibers maintained the fibrous morphology even after keeping in contact with aqueous medium. The morphology of the cross-linked nanofibrous mats was examined by scanning electron microscopy (SEM). Oxidized sucrose cross-linked gelatin nanofibers exhibited improved thermal and mechanical properties. The nanofibrous mats were evaluated for cytotoxicity and cell viability using L-929 fibroblast cells. The results confirmed that oxidized sucrose cross-linked gelatin nanofibers were non-cytotoxic towards L-929 cells with good cell viability.

  13. Fourier transform infrared detection in miniaturized total analysis systems for sucrose analysis.

    PubMed

    Lendl, B; Schindler, R; Frank, J; Kellner, R; Drott, J; Laurell, T

    1997-08-01

    In this work, a flow system containing a micromachined lamella-type porous silicon reactor and a novel mid-IR fiber-optic flow cell were used for the enzymatic determination of sucrose in aqueous solution. The method relies on the enzymatic hydrolysis of sucrose to fructose and glucose catalyzed by β-fructosidase and on the acquisition of FT-IR spectra before and after complete reaction. β-Fructosidase was covalently bound to the porous silicon surface of the channels in the microreactor. The porous silicon was achieved by anodization of the silicon reactor in a HF/ethanol mixture. For the measurement of small amounts of aqueous solution, a miniaturized flow cell was developed which consisted of two AgCl(x)Br(1)(-)(x) fiber tips (diameter, 0.75 mm) coaxially mounted in a PTFE block at a distance of 23 μm. The flowing stream was directed through the gap of the two fiber tips which served to define the optical path length and to bring the focused mid-IR radiation to the place of measurement. Using this construction, a probed volume of ∼10 nL was obtained. The calibration curve was linear between 10 and 100 mmol/L sucrose. Furthermore, the potential of this method was demonstrated by the analysis of binary sucrose/glucose mixtures showing no interference from glucose and by the successful determination of sucrose in real samples.

  14. Asteroid Densities

    NASA Astrophysics Data System (ADS)

    Britt, D. T.; Yeomans, D.; Housen, K.; Consolmagno, G.

    2005-01-01

    This data set contains a tabulation of asteroid masses, diameters, and bulk densities compiled by D. T. Britt and published in Table 1 of Britt, et al. (2002) [BRITTETAL2002] in the 'Asteroids III' volume.

  15. Behavioral and circuit basis of sucrose rejection by Drosophila females in a simple decision-making task.

    PubMed

    Yang, Chung-Hui; He, Ruo; Stern, Ulrich

    2015-01-28

    Drosophila melanogaster egg-laying site selection offers a genetic model to study a simple form of value-based decision. We have previously shown that Drosophila females consistently reject a sucrose-containing substrate and choose a plain (sucrose-free) substrate for egg laying in our sucrose versus plain decision assay. However, either substrate is accepted when it is the sole option. Here we describe the neural mechanism that underlies females' sucrose rejection in our sucrose versus plain assay. First, we demonstrate that females explored the sucrose substrate frequently before most egg-laying events, suggesting that they actively suppress laying eggs on the sucrose substrate as opposed to avoiding visits to it. Second, we show that activating a specific subset of DA neurons triggered a preference for laying eggs on the sucrose substrate over the plain one, suggesting that activating these DA neurons can increase the value of the sucrose substrate for egg laying. Third, we demonstrate that neither ablating nor inhibiting the mushroom body (MB), a known Drosophila learning and decision center, affected females' egg-laying preferences in our sucrose versus plain assay, suggesting that MB does not mediate this specific decision-making task. We propose that the value of a sucrose substrate- as an egg-laying option-can be adjusted by the activities of a specific DA circuit. Once the sucrose substrate is determined to be the lesser valued option, females execute their decision to reject this inferior substrate not by stopping their visits to it, but by actively suppressing their egg-laying motor program during their visits.

  16. Evaluation of the risk of fungal spoilage when substituting sucrose with commercial purified Stevia glycosides in sweetened bakery products.

    PubMed

    Rodríguez, Alicia; Magan, Naresh; Medina, Angel

    2016-08-16

    The objectives of this study were to compare the effect of different Stevia-based sugar substitutes (S1-S3), sucrose alone and a mixture of sucrose+S1 on: (a) humectant properties, (b) relative colonisation rates of sponge cake slices at 0.90 aw by strains of Aspergillus flavus, Eurotium amstelodami, Fusarium graminearum and Penicillium verrucosum at 20 and 25°C and (c) shelf-life periods in days prior to visible growth. Results showed that sucrose, S1 commercial sugar substitute and the mixture of sucrose+S1 in water solutions were able to reach water activity levels similar to those of glycerol and glucose mixtures. The S2 and S3 commercial sugar substitutes were unable to reduce aw levels significantly. At 25°C, colonisation of sponge cake slices by E. amstelodami, A. flavus and P. verrucosum occurred in all the treatments. Growth of F. graminearum only occurred on sponge cake slices containing S2 and S3 Stevia-based products at both temperatures. The best control of growth (30days) was achieved in cake slices modified with sucrose or S1 Stevia treatments inoculated with A. flavus and in the sucrose treatment for E. amstelodami at 20°C. F. graminearum growth was completely inhibited when sucrose alone, S1 or sucrose+S1 treatments were used at both temperatures. This study suggests that, as part of a hurdle technology approach, replacing sucrose with low calorie sugar substitutes based on Stevia glycosides needs to be done with care. This is because different products may have variable humectant properties and bulking agents which may shorten the potential shelf-life of intermediate moisture bakery products.

  17. Response of Desulfovibrio vulgaris to alkaline stress.

    PubMed

    Stolyar, Sergey; He, Qiang; Joachimiak, Marcin P; He, Zhili; Yang, Zamin Koo; Borglin, Sharon E; Joyner, Dominique C; Huang, Katherine; Alm, Eric; Hazen, Terry C; Zhou, Jizhong; Wall, Judy D; Arkin, Adam P; Stahl, David A

    2007-12-01

    The response of exponentially growing Desulfovibrio vulgaris Hildenborough to pH 10 stress was studied using oligonucleotide microarrays and a study set of mutants with genes suggested by microarray data to be involved in the alkaline stress response deleted. The data showed that the response of D. vulgaris to increased pH is generally similar to that of Escherichia coli but is apparently controlled by unique regulatory circuits since the alternative sigma factors (sigma S and sigma E) contributing to this stress response in E. coli appear to be absent in D. vulgaris. Genes previously reported to be up-regulated in E. coli were up-regulated in D. vulgaris; these genes included three ATPase genes and a tryptophan synthase gene. Transcription of chaperone and protease genes (encoding ATP-dependent Clp and La proteases and DnaK) was also elevated in D. vulgaris. As in E. coli, genes involved in flagellum synthesis were down-regulated. The transcriptional data also identified regulators, distinct from sigma S and sigma E, that are likely part of a D. vulgaris Hildenborough-specific stress response system. Characterization of a study set of mutants with genes implicated in alkaline stress response deleted confirmed that there was protective involvement of the sodium/proton antiporter NhaC-2, tryptophanase A, and two putative regulators/histidine kinases (DVU0331 and DVU2580).

  18. Autonomous in situ measurements of seawater alkalinity.

    PubMed

    Spaulding, Reggie S; DeGrandpre, Michael D; Beck, James C; Hart, Robert D; Peterson, Brittany; De Carlo, Eric H; Drupp, Patrick S; Hammar, Terry R

    2014-08-19

    Total alkalinity (AT) is an important parameter for describing the marine inorganic carbon system and understanding the effects of atmospheric CO2 on the oceans. Measurements of AT are limited, however, because of the laborious process of collecting and analyzing samples. In this work we evaluate the performance of an autonomous instrument for high temporal resolution measurements of seawater AT. The Submersible Autonomous Moored Instrument for alkalinity (SAMI-alk) uses a novel tracer monitored titration method where a colorimetric pH indicator quantifies both pH and relative volumes of sample and titrant, circumventing the need for gravimetric or volumetric measurements. The SAMI-alk performance was validated in the laboratory and in situ during two field studies. Overall in situ accuracy was -2.2 ± 13.1 μmol kg(-1) (n = 86), on the basis of comparison to discrete samples. Precision on duplicate analyses of a carbonate standard was ±4.7 μmol kg(-1) (n = 22). This prototype instrument can measure in situ AT hourly for one month, limited by consumption of reagent and standard solutions.

  19. Advanced inorganic separators for alkaline batteries

    NASA Technical Reports Server (NTRS)

    Sheibley, D. W. (Inventor)

    1982-01-01

    A flexible, porous battery separator comprising a coating applied to a porous, flexible substrate is described. The coating comprises: (1) a thermoplastic rubber-based resin which is insoluble and unreactive in the alkaline electrolyte; (2) a polar organic plasticizer which is reactive with the alkaline electrolyte to produce a reaction product which contains a hydroxyl group and/or a carboxylic acid group; and (3) a mixture of polar particulate filler materials which are unreactive with the electrolyte, the mixture comprising at least one first filler material having a surface area of greater than 25 meters sq/gram, at least one second filler material having a surface area of 10 to 25 sq meters/gram, wherein the volume of the mixture of filler materials is less than 45% of the total volume of the fillers and the binder, the filler surface area per gram of binder is about 20 to 60 sq meters/gram, and the amount of plasticizer is sufficient to coat each filler particle. A method of forming the battery separator is also described.

  20. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    SciTech Connect

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  1. Thermodynamic model for an alkaline fuel cell

    NASA Astrophysics Data System (ADS)

    Verhaert, Ivan; De Paepe, Michel; Mulder, Grietus

    Alkaline fuel cells are low temperature fuel cells for which stationary applications, e.g. cogeneration in buildings, are a promising market. In order to guarantee a long life, water and thermal management has to be done in a careful way. In order to better understand the water, alkali and thermal flows, a two-dimensional model for an Alkaline Fuel Cell is developed using a control volume approach. In each volume the electrochemical reactions together with the mass and energy balance are solved. The model is created in Aspen Custom Modeller, the development environment of Aspen Plus, where special attention is given to the physical flow of hydrogen, water and air in the system. In this way the developed component, the AFC-cell, can be built into stack configurations to understand its effect on the overall performance. The model is validated by experimental data from measured performance by VITO with their Cell Voltage Monitor at a test case, where the AFC-unit is used as a cogeneration unit.

  2. The effect of alkaline agents on retention of EOR chemicals

    SciTech Connect

    Lorenz, P.B.

    1991-07-01

    This report summarizes a literature survey on how alkaline agents reduce losses of surfactants and polymers in oil recovery by chemical injection. Data are reviewed for crude sulfonates, clean anionic surfactants, nonionic surfactants, and anionic and nonionic polymers. The role of mineral chemistry is briefly described. Specific effects of various alkaline anions are discussed. Investigations needed to improve the design of alkaline-surfactant-polymer floods are suggested. 62 refs., 28 figs., 6 tabs.

  3. Partitioning and transport of the translocates mannitol and sucrose in the light and dark in celery (Apium Graveolens L. )

    SciTech Connect

    Davis, J.M.; Loescher, W.H.

    1987-04-01

    Sucrose and mannitol are major photosynthetic products and translocates in celery. Assimilate partitioning and transport were studied by pulse-labeling leaves with /sup 14/CO/sub 2/ followed by different length chases in ambient air. After a 2 h chase in the light there was more /sup 14/C in sucrose than mannitol in source leaves and their petioles. In contrast after a 2 h dark chase leaves contained more /sup 14/C in mannitol than sucrose but petioles had more /sup 14/C in sucrose than mannitol. After a 15 h chase (6 h light; 9 h dark) labeled sucrose was higher in source petiole vascular bundles than in adjacent parenchyma tissue but label in glucose and fructose was higher in the parenchyma tissue. After the 15 h chase most of the /sup 14/C remaining in developing sink leaves and their petioles was in mannitol. Although in the light mannitol:sucrose ratios are the same in leaf and petiole tissues, in the dark sucrose is initially the major translocate with mannitol becoming more important as leaf sucrose pools are depleted. When synthesized, sucrose is rapidly transported and then metabolized to hexose sugars whereas mannitol is used both for transport and storage.

  4. In vivo sucrose stimulation of colour change in citrus fruit epicarps: Interactions between nutritional and hormonal signals.

    PubMed

    Iglesias, Domingo J.; Tadeo, Francisco R.; Legaz, Francisco; Primo-Millo, Eduardo; Talon, Manuel

    2001-06-01

    During ripening, citrus fruit-peel undergoes 'colour break', a process characterized by the conversion of chloroplast to chromoplast. The process involves the progressive loss of chlorophylls and the gain of carotenoids, changing peel colour from green to orange. In the present work, the in vivo and in vitro effects of supplemented nutrients (sucrose and nitrogen) and phytohormones (gibberellins [GA] and ethylene) on colour change in fruit epicarp of Satsuma mandarin (Citrus unshiu (Mak.) Marc., cv. Okitsu), were studied. The rate of colour break was correlated positively with sucrose content and negatively with nitrogen content. The removal of leaves blocked natural sucrose build-up and nitrogen reduction in the peel. Defoliation also inhibited chlorophyll disappearance and carotenoid accumulation, thereby preventing colour break. In vivo sucrose supplementation promoted sucrose accumulation and advanced colour break. In both in vivo and in vitro experiments, colour change promoted by sucrose was unaffected by ethylene but delayed by GA3. In non-supplemented plants, ethylene accelerated colour break while GA3 had no detectable effects. Ethylene inhibitors effectively counteracted the sucrose effects on colour change. Collectively, these results suggest that the chloroplast to chromoplast conversion in citrus fruit epicarps is stimulated by sucrose accumulation. The sugar regulation appears to operate via ethylene, whereas GA may act as a repressor of the sucrose-ethylene stimulation.

  5. The fungal UmSrt1 and maize ZmSUT1 sucrose transporters battle for plant sugar resources.

    PubMed

    Wittek, Anke; Dreyer, Ingo; Al-Rasheid, Khaled A S; Sauer, Norbert; Hedrich, Rainer; Geiger, Dietmar

    2017-03-15

    The biotrophic fungus Ustilago maydis causes the corn smut disease inducing tumor formation in its host Zea mays. Upon infection, the fungal hyphae invaginate the plasma membrane of infected maize cells establishing an interface where pathogen and host are separated only by their plasma membranes. At this interface the fungal and maize sucrose transporters, UmSrt1 and ZmSUT1, compete for extracellular sucrose in the corn smut/maize pathosystem. Here we biophysically characterized ZmSUT1 and UmSrt1 in Xenopus oocytes with respect to their voltage-, pH- and substrate-dependence and determined affinities towards protons and sucrose. In contrast to ZmSUT1, UmSrt1 has a high-affinity for sucrose and is relatively pH- and voltage-independent. Using these quantitative parameters, we developed a mathematical model to simulate the competition for extracellular sucrose at the contact zone between the fungus and the host plant. This approach revealed that UmSrt1 exploits the apoplastic sucrose resource, which forces the plant transporter into a sucrose export mode providing the fungus with sugar from the phloem. Importantly, the high sucrose concentration in the phloem appeared disadvantageous for the ZmSUT1, preventing sucrose recovery from the apoplastic space in the fungus/plant interface.

  6. REPEATED ETHANOL ADMINISTRATION MODIFIES THE TEMPORAL STRUCTURE OF SUCROSE INTAKE PATTERNS IN MICE: EFFECTS ASSOCIATED WITH BEHAVIORAL SENSITIZATION

    PubMed Central

    Pastor, Raúl; Kamens, Helen M.; McKinnon, Carrie S.; Ford, Matthew M.; Phillips, Tamara J.

    2010-01-01

    Neuroadaptations supporting behavioral sensitization to abused drugs are suggested to underlie pathological, excessive motivation toward drugs and drug-associated stimuli. Drug-induced sensitization has also been linked to increased appetitive responses for non-drug, natural reinforcers. The present research investigated whether ethanol (EtOH)-induced neural changes, inferred from psychomotor sensitization, can modify consumption and intake dynamics for the natural reinforcer, sucrose. The effects of EtOH-induced sensitization in mice on the temporal structure of sucrose intake patterns were measured using a lickometer system. Sucrose intake dynamics were measured after sensitization for 1 h daily for 7 days and indicated more rapid initial approach and consumption of sucrose in EtOH-sensitized groups; animals showed a shorter latency to the first intake bout and an increased number of sucrose bottle licks during the initial 15 min of the 1-h sessions. This effect was associated with increased frequency and size of bouts. For the total 1-h session, sucrose intake and bout dynamics were not different between groups, indicating a change in patterns of sucrose intake but not total consumption. When sensitization was prevented by the GABAB receptor agonist baclofen, the increased rate of approach and consumption of sucrose were also prevented. Thus, EtOH-induced sensitization, and not the mere exposure to EtOH, was associated with changes in sucrose intake patterns. These data are consistent with current literature suggesting an enhancing effect of drug-induced sensitization on motivational processes involved in reinforcement. PMID:20624153

  7. Assembly of a Cost-Effective Anode Using Palladium Nanoparticles for Alkaline Fuel Cell Applications

    PubMed Central

    2015-01-01

    Nanotechnology allows the synthesis of nanoscale catalysts, which offer an efficient alternative for fuel cell applications. In this laboratory experiment, the student selects a cost-effective anode for fuel cells by comparing three different working electrodes. These are commercially available palladium (Pd) and glassy carbon (GC) electrodes, and a carbon paste (CP) electrode that is prepared by the students in the laboratory. The GC and CP were modified with palladium nanoparticles (PdNP) suspensions. The electrodes efficiencies were studied for ethanol oxidation in alkaline solution using cyclic voltammetry techniques. The ethanol oxidation currents obtained were used to determine the current density using the geometric and surface area of each electrode. Finally, students were able to choose the best electrode and relate catalytic activity to surface area for ethanol oxidation in alkaline solution by completing a critical analysis of the cyclic voltammetry results. With this activity, fundamental electrochemical concepts were reinforced. PMID:25691801

  8. Polyhydroxyflavones as extractants. Communication 7. Solvent extraction of europrium complexes with morin from alkaline media

    SciTech Connect

    Blank, A.B.

    1985-09-01

    This paper studies the analytical application of europium (III)-morin complex which is formed in alkaline medium and has an intense color. The extent of europium extraction was determined by adding to the extract a morin solution in isoamyl alcohol in a 50-100-fold excess with respect to europium. The dependence of the optical density of the extracts on the ph in the system europium (III)-morin-water-organic solvent for different excesses of the reagent is shown: this indicates formation of two extractable complexes, one being dominant in the pH range 4-7, the other at pH greater than or equal to 8.5. The extraction of the europium (III)-morin complex from alkaline solution is used for direct extraction-photometric determination of europium(III) in compounds of elements having amphoteric properties or forming amines (Zns, Mo0/sub 3/).

  9. Electricity generation from macroalgae Enteromorpha prolifera hydrolysates using an alkaline fuel cell.

    PubMed

    Liu, Susu; Liu, Xianhua; Wang, Ying; Zhang, Pingping

    2016-12-01

    The goal of this work was to develop a method for the direct power generation using macroalgae Enteromorpha prolifera. The process conditions for the saccharification of macroalgae were optimized and a type of alkaline fuel cell contained no precious metal catalysts was developed. Under optimum conditions (170°C and 2% hydrochloric acid for 45min), dilute acid hydrolysis of the homogenized plants yielded 272.25g reducing sugar/kg dry algal biomass. The maximum power density reached 3.81W/m(2) under the condition of 3M KOH and 18.15g/L reducing sugar in hydrolysate, higher than any other reported algae-fed fuel cells. This study represents the first report on direct electricity generation from macroalgae using alkaline fuel cells, suggesting that there is great potential for the production of renewable energy using marine biomass.

  10. Assembly of a Cost-Effective Anode Using Palladium Nanoparticles for Alkaline Fuel Cell Applications.

    PubMed

    Feliciano-Ramos, Ileana; Casañas-Montes, Barbara; García-Maldonado, María M; Menéndez, Christian L; Mayol, Ana R; Díaz-Vázquez, Liz M; Cabrera, Carlos R

    2015-02-10

    Nanotechnology allows the synthesis of nanoscale catalysts, which offer an efficient alternative for fuel cell applications. In this laboratory experiment, the student selects a cost-effective anode for fuel cells by comparing three different working electrodes. These are commercially available palladium (Pd) and glassy carbon (GC) electrodes, and a carbon paste (CP) electrode that is prepared by the students in the laboratory. The GC and CP were modified with palladium nanoparticles (PdNP) suspensions. The electrodes efficiencies were studied for ethanol oxidation in alkaline solution using cyclic voltammetry techniques. The ethanol oxidation currents obtained were used to determine the current density using the geometric and surface area of each electrode. Finally, students were able to choose the best electrode and relate catalytic activity to surface area for ethanol oxidation in alkaline solution by completing a critical analysis of the cyclic voltammetry results. With this activity, fundamental electrochemical concepts were reinforced.

  11. Reaction rate modeling in cryoconcentrated solutions: alkaline phosphatase catalyzed DNPP hydrolysis.

    PubMed

    Champion, D; Blond, G; Le Meste, M; Simatos, D

    2000-10-01

    The hydrolysis of disodium p-nitrophenyl phosphate catalyzed by alkaline phosphatase was chosen as a model to study the kinetics of changes in frozen food products. The initial reaction rate was determined in concentrated sucrose solutions down to -24 degrees C, and the enzymatic characteristics K(M) and V(max) were calculated. The experimental data were compared to the kinetics predicted by assuming that the reaction was viscosity dependent. Indeed, an analysis of the enzymatic reaction demonstrated that both the diffusion of the substrate and the flexibility of the enzyme segments were controlled by the high viscosity of the media. When the temperature was too low for the viscosity to be measured simply, the Williams-Landel-Ferry equation was used to predict the viscosity, taking, as reference temperature, the glass transition temperature (T(g)) corresponding to the concentration of the freeze-concentrated phase at the test temperature. Predicted values of the reaction rate were very close to the experimental ones in the studied temperature range.

  12. Stability of thermostable alkaline protease from Bacillus licheniformis RP1 in commercial solid laundry detergent formulations.

    PubMed

    Sellami-Kamoun, Alya; Haddar, Anissa; Ali, Nedra El-Hadj; Ghorbel-Frikha, Basma; Kanoun, Safia; Nasri, Moncef

    2008-01-01

    The stability of crude extracellular protease produced by Bacillus licheniformis RP1, isolated from polluted water, in various solid laundry detergents was investigated. The enzyme had an optimum pH and temperature at pH 10.0-11.0 and 65-70 degrees C. Enzyme activity was inhibited by PMSF, suggesting that the preparation contains a serine-protease. The alkaline protease showed extreme stability towards non-ionic (5% Tween 20% and 5% Triton X-100) and anionic (0.5% SDS) surfactants, which retained 100% and above 73%, respectively, of its initial activity after preincubation 60 min at 40 degrees C. The RP1 protease showed excellent stability and compatibility with a wide range of commercial solid detergents at temperatures from 40 to 50 degrees C, suggesting its further application in detergent industry. The enzyme retained 95% of its initial activity with Ariel followed by Axion (94%) then Dixan (93.5%) after preincubation 60 min at 40 degrees C in the presence of 7 mg/ml of detergents. In the presence of Nadhif and New Det, the enzyme retained about 83.5% of the original activity. The effects of additives such as maltodextrin, sucrose and PEG 4000 on the stability of the enzyme during spray-drying and during subsequent storage in New Det detergent were also examined. All additives tested enhanced stability of the enzyme.

  13. Deficient sucrose synthase activity in developing wood does not specifically affect cellulose biosynthesis, but causes an overall decrease in cell wall polymers.

    PubMed

    Gerber, Lorenz; Zhang, Bo; Roach, Melissa; Rende, Umut; Gorzsás, András; Kumar, Manoj; Burgert, Ingo; Niittylä, Totte; Sundberg, Björn

    2014-09-01

    The biosynthesis of wood in aspen (Populus) depends on the metabolism of sucrose, which is the main transported form of carbon from source tissues. The largest fraction of the wood biomass is cellulose, which is synthesized from UDP-glucose. Sucrose synthase (SUS) has been proposed previously to interact directly with cellulose synthase complexes and specifically supply UDP-glucose for cellulose biosynthesis. To investigate the role of SUS in wood biosynthesis, we characterized transgenic lines of hybrid aspen with strongly reduced SUS activity in developing wood. No dramatic growth phenotypes in glasshouse-grown trees were observed, but chemical fingerprinting with pyrolysis-GC/MS, together with micromechanical analysis, showed notable changes in chemistry and ultrastructure of the wood in the transgenic lines. Wet chemical analysis showed that the dry weight percentage composition of wood polymers was not changed significantly. However, a decrease in wood density was observed and, consequently, the content of lignin, hemicellulose and cellulose was decreased per wood volume. The decrease in density was explained by a looser structure of fibre cell walls as shown by increased wall shrinkage on drying. The results show that SUS is not essential for cellulose biosynthesis, but plays a role in defining the total carbon incorporation to wood cell walls.

  14. Dietary Garcinia cambogia does not modify skin properties of mice with or without excessive sucrose intake.

    PubMed

    Oikawa, Daichi; Hirakawa, Hachidai; Hayamizu, Kohsuke; Nakamura, Yoshinori; Shiba, Nobuya; Nakanishi, Tomonori; Iwamoto, Hisao; Tachibana, Tetsuya; Furuse, Mitsuhiro

    2005-04-01

    The influence of 3.3% Garcinia cambogia extract on the properties of mouse skin with or without 10% sucrose water loading was investigated. Mice (7-week-old) were given free access to a control diet or a diet containing Garcinia cambogia extract. They were also given water alone or both water and sucrose water. Their skin was compared by both biochemical and histological methods. The collagen and triacylglycerol contents were not significantly different among the four groups. Similarly, electron microscopy revealed no differences in the thickness of the dermis layer or the subcutaneous tissue layer. Mice given the diet containing Garcinia cambogia tended to have a reduced total number of adipocytes, but not significantly. These results suggest that Garcinia cambogia supplementation for at least 4 weeks does not induce a negative effect on skin properties in mice irrespective of excessive sucrose intake.

  15. Cloning and expression of the sucrose phosphorylase gene from Leuconostoc mesenteroides in Escherichia coli.

    PubMed

    Lee, Jin-Ha; Moon, Young-Hwan; Kim, Nahyun; Kim, Young-Min; Kang, Hee-Kyoung; Jung, Ji-Yeon; Abada, Emad; Kang, Seong-Soo; Kim, Doman

    2008-04-01

    The gene encoding sucrose phosphorylase (742sp) in Leuconostoc mesenteroides NRRL B-742 was cloned and expressed in Escherichia coli. The nucleotide sequence of the transformed 742sp comprised an ORF of 1,458 bp giving a protein with calculated molecular mass of 55.3 kDa. 742SPase contains a C-terminal amino acid sequence that is significantly different from those of other Leu. mesenteroides SPases. The purified 742SPase had a specific activity of 1.8 U/mg with a K (m) of 3 mM with sucrose as a substrate; optimum activity was at 37 degrees C and pH 6.7. The purified 742SPase transferred the glucosyl moiety of sucrose to cytosine monophosphate (CMP).

  16. High efficiency dye sensitized solar cell made by carbon derived from sucrose

    NASA Astrophysics Data System (ADS)

    Kumar, Rahul; Nemala, Siva Sankar; Mallick, Sudhanshu; Bhargava, Parag

    2017-02-01

    Carbon materials represent an attractive alternative to platinum based counter electrodes in DSSCs. Graphitic carbon produced from carbonization of sucrose has been used for making counter electrode for DSSCs. It was observed that increment in thickness of carbon counter electrode improves the performance of DSSCs. Electrochemical impedance spectroscopy, Tafel polarization and cyclic voltammetry measurements suggest that sucrose derived carbon based counter electrode shows fast reduction rate of I3- compare with platinum based counter electrode. DSSCs based on sucrose derived carbon exhibit high power conversion efficiency (PCE) of 9.96% and fill factor (FF) of 0.72 which is higher than PCE of 9.39% and FF of 0.67 of the cells with platinum (Pt) based counter electrode.

  17. Determination of sucrose in equine serum using liquid chromatography-mass spectrometry (LC/MS).

    PubMed

    D'Arcy-Moskwa, E; Weston, L; Noble, G N; Raidal, S L

    2011-11-15

    Mucosal integrity may be objectively assessed by determination of the absorption of exogenous substances such as sucrose. Gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) have been reported for the accurate quantification of low concentrations of sucrose in serum. LC/MS offered the advantage of high sensitivity and mass selectivity without the need for extensive sample derivatization required for GC/MS methods. However, the high polarity and non-volatile nature of the sucrose molecule renders LC/MS techniques challenging. Previously published reports lacked sufficient detail to permit replication of methodology. Problems encountered with existing protocols included poor peak resolution and weak fragmentation of the parent molecule. This communication describes a LC/MS protocol developed to provide improved resolution and product detection.

  18. Expression, purification and preliminary crystallographic analysis of sucrose phosphate synthase (SPS) from Halothermothrix orenii

    SciTech Connect

    Huynh, Frederick; Tan, Tien-Chye; Swaminathan, Kunchithapadam; Patel, Bharat K. C.

    2005-01-01

    The first crystallographic study of a sucrose phosphate synthase from H. orenii, an organism that is both thermophilic and halophilic, is reported. The protein crystal diffracts X-rays to 3.01 Å. This is the first report of the crystallization of a sucrose phosphate synthase (SPS; EC 2.4.1.14). It also constitutes the first study of a sucrose phosphate synthase from a non-photosynthetic thermohalophilic anaerobic bacterium, Halothermothrix orenii. The purified recombinant spsA protein has been crystallized in the monoclinic space group C2, with unit-cell parameters a = 154.2, b = 47.9, c = 72.3 Å, β = 103.16°, using the hanging-drop vapour-diffusion method. The crystal diffracts X-rays to a resolution limit of 3.01 Å. Heavy-metal and halide-soaking trials are currently in progress to solve the structure.

  19. Dynamics modeling for sugar cane sucrose estimation using time series satellite imagery

    NASA Astrophysics Data System (ADS)

    Zhao, Yu; Justina, Diego Della; Kazama, Yoriko; Rocha, Jansle Vieira; Graziano, Paulo Sergio; Lamparelli, Rubens Augusto Camargo

    2016-10-01

    Sugarcane, as one of the most mainstay crop in Brazil, plays an essential role in ethanol production. To monitor sugarcane crop growth and predict sugarcane sucrose content, remote sensing technology plays an essential role while accurate and timely crop growth information is significant, in particularly for large scale farming. We focused on the issues of sugarcane sucrose content estimation using time-series satellite image. Firstly, we calculated the spectral features and vegetation indices to make them be correspondence to the sucrose accumulation biological mechanism. Secondly, we improved the statistical regression model considering more other factors. The evaluation was performed and we got precision of 90% which is about 20% higher than the conventional method. The validation results showed that prediction accuracy using our sugarcane growth modeling and improved mix model is satisfied.

  20. Sucrose and invertases, a part of the plant defense response to the biotic stresses

    PubMed Central

    Tauzin, Alexandra S.; Giardina, Thierry

    2014-01-01

    Sucrose is the main form of assimilated carbon which is produced during photosynthesis and then transported from source to sink tissues via the phloem. This disaccharide is known to have important roles as signaling molecule and it is involved in many metabolic processes in plants. Essential for plant growth and development, sucrose is engaged in plant defense by activating plant immune responses against pathogens. During infection, pathogens reallocate the plant sugars for their own needs forcing the plants to modify their sugar content and triggering their defense responses. Among enzymes that hydrolyze sucrose and alter carbohydrate partitioning, invertases have been reported to be affected during plant-pathogen interactions. Recent highlights on the role of invertases in the establishment of plant defense responses suggest a more complex regulation of sugar signaling in plant-pathogen interaction. PMID:25002866

  1. Determination of hydrophobicity of dry-heated wheat starch granules using sucrose fatty acid esters (SFAE).

    PubMed

    Tabara, Aya; Oneda, Hiroshi; Murayama, Ryuji; Matsui, Yuko; Hirano, Akira; Seguchi, Masaharu

    2014-01-01

    Sucrose fatty acid esters (SFAE) were adsorbed onto dry-heated (120 °C for 10, 20, 40, 60, and 120 min) wheat starch granules and extracted with ethyl ether in a Soxhlet apparatus without gelatinization of the starch granules. The amount of sucrose in the extracted SFAE was determined by the phenol sulfate method. A gradual increase of the sucrose from 159 to 712 μg, in SFAE per gram of starch, occurred with increasing dry-heating time and demonstrated the increased hydrophobicity of the starch granules. Increase of the SFAE was highly correlated (r = 0.9816) to increase of the oil-binding capacity of the dry-heated wheat starch granules. Non-waxy rice, waxy rice, sweet potato, and potato starch granules also showed higher hydrophobicity after dry-heating by this method.

  2. PCR-generated molecular markers for the invertase gene and sucrose accumulation in tomato.

    PubMed

    Hadas, R; Schaffer, A; Miron, D; Fogelman, M; Granot, D

    1995-06-01

    The green-fruited tomato species, Lycopersicon hirsutum, unlike the domesticated red-fruited species, L. esculentum, accumulates sucrose during the final stages of fruit development, concomitant with the loss of soluble acid invertase activity. In order to study the genetic linkage of sucrose accumulation to the invertase gene, part of the invertase gene from L. hirsutum was cloned, sequenced and the sequence compared with the invertase sequence of the red-fruited L. esculentum. Several base changes were found in the coding region of the two invertase genes. Based on these base -pair differences, we developed a species-specific PCR assay capable of determining, in a single PCR reaction, the origin of the invertase gene in segregating seedlings of an interspecific cross. Our results indicate that the invertase gene is genetically linked to sucrose accumulation in the green-fruited L. hirsutum.

  3. Decreased expression of two key enzymes in the sucrose biosynthesis pathway, cytosolic fructose-1,6-bisphosphatase and sucrose phosphate synthase, has remarkably different consequences for photosynthetic carbon metabolism in transgenic Arabidopsis thaliana.

    PubMed

    Strand, A; Zrenner, R; Trevanion, S; Stitt, M; Gustafsson, P; Gardeström, P

    2000-09-01

    Photosynthetic carbon metabolism was investigated in antisense Arabidopsis lines with decreased expression of sucrose phosphate synthase (SPS) and cytosolic fructose-1,6-bisphosphatase (cFBPase). In the light, triose phosphates are exported from the chloroplast and converted to sucrose via cFBPase and SPS. At night, starch is degraded to glucose, exported and converted to sucrose via SPS. cFBPase therefore lies upstream and SPS downstream of the point at which the pathways for sucrose synthesis in the day and night converge. Decreased cFBPase expression led to inhibition of sucrose synthesis; accumulation of phosphorylated intermediates; Pi-limitation of photosynthesis; and stimulation of starch synthesis. The starch was degraded to maintain higher levels of sugars and a higher rate of sucrose export during the night. This resembles the response in other species when expression of enzymes in the upper part of the sucrose biosynthesis pathway is reduced. Decreased expression of SPS inhibited sucrose synthesis, but phosphorylated intermediates did not accumulate and carbon partitioning was not redirected towards starch. Sugar levels and sucrose export was decreased during the night as well as during the day. Although ribulose-1,5-bisphosphate regeneration and photosynthesis were inhibited, the PGA/triose-P ratio remained low and the ATP/ADP ratio high, showing that photosynthesis was not limited by the rate at which Pi was recycled during end-product synthesis. Two novel responses counteracted the decrease in SPS expression and explain why phosphorylated intermediates did not accumulate, and why allocation was not altered in the antisense SPS lines. Firstly, a threefold decrease of PPi and a shift of the UDP-glucose/hexose phosphate ratio favoured sucrose synthesis and prevented the accumulation of phosphorylated intermediates. Secondly, there was no increase of AGPase activity relative to cFBPase activity, which would prevent a shift in carbon allocation towards

  4. Stability of low concentrations of guanine-based antivirals in sucrose or maltitol solutions.

    PubMed

    Desai, D; Rao, V; Guo, H; Li, D; Bolgar, M

    2007-09-05

    Three guanine-based antiviral drugs, entecavir, lobucavir, and acyclovir showed degradation in presence of sucrose in ready-to-use solutions held at 50 degrees C, with more degradation at pH 4 than at pH 6 or 7. LC/MS analysis of the solutions showed isomeric adducts of the drugs and reducing sugars. Sucrose, a disaccharide and a non-reducing sugar, was the source of monosaccharides, the reducing sugars. Sucrose showed pH-dependent hydrolysis at 50 degrees C into two monosaccharides, fructose and glucose, with more sucrose hydrolyzing at pH 4 than pH 6 or 7. Additionally, the three drugs showed pH-dependent degradation at 50 degrees C in fructose and glucose solutions with the following rank order: pH 7>pH 6>pH 4. This indicated that the increased degradation of the drugs in sucrose solutions at pH 4 was mainly due to more hydrolysis of sucrose into fructose and glucose compared to pH 6 or 7, and subsequent reactions of the fructose and glucose with the drugs. Based on structures of the major degradants, it is proposed that the main cause of the degradation was nucleophilic addition of the primary amine group of the drugs to the carbonyl group of the fructose and glucose. This reaction was facilitated as the solution pH increased from 4 to 7. All the drugs showed satisfactory stability regardless of the storage temperature or solution pH in maltitol, an alternate sweetener. The free aldehyde or ketone group in maltitol precursors is reduced to a hydroxyl group after the hydrogenation process making maltitol less susceptible to nucleophilic addition.

  5. A randomized trial of iron isomaltoside versus iron sucrose in patients with iron deficiency anemia

    PubMed Central

    Roman, Eloy; Modiano, Manuel R.; Achebe, Maureen M.; Thomsen, Lars L.; Auerbach, Michael

    2017-01-01

    Abstract Iron deficiency anemia (IDA) is common in many chronic diseases, and intravenous (IV) iron offers a rapid and efficient iron correction. This trial compared the efficacy and safety of iron isomaltoside and iron sucrose in patients with IDA who were intolerant of, or unresponsive to, oral iron. The trial was an open‐label, comparative, multi‐center trial. Five hundred and eleven patients with IDA from different causes were randomized 2:1 to iron isomaltoside or iron sucrose and followed for 5 weeks. The cumulative dose of iron isomaltoside was based on body weight and hemoglobin (Hb), administered as either a 1000 mg infusion over more than 15 minutes or 500 mg injection over 2 minutes. The cumulative dose of iron sucrose was calculated according to Ganzoni and administered as repeated 200 mg infusions over 30 minutes. The mean cumulative dose of iron isomaltoside was 1640.2 (standard deviation (SD): 357.6) mg and of iron sucrose 1127.9 (SD: 343.3) mg. The primary endpoint was the proportion of patients with a Hb increase ≥2 g/dL from baseline at any time between weeks 1‐5. Both non‐inferiority and superiority were confirmed for the primary endpoint, and a shorter time to Hb increase ≥2 g/dL was observed with iron isomaltoside. For all biochemical efficacy parameters, faster and/or greater improvements were found with iron isomaltoside. Both treatments were well tolerated; 0.6% experienced a serious adverse drug reaction. Iron isomaltoside was more effective than iron sucrose in achieving a rapid improvement in Hb. Furthermore, iron isomaltoside has an advantage over iron sucrose in allowing higher cumulative dosing in fewer administrations. Both treatments were well tolerated in a broad population with IDA. PMID:28052413

  6. Invertase-nanogold clusters decorated plant membranes for fluorescence-based sucrose sensor.

    PubMed

    Bagal-Kestwal, Dipali; Kestwal, Rakesh Mohan; Chiang, Been-Huang

    2015-04-12

    In the present study, invertase-mediated nanogold clusters were synthesized on onion membranes, and their application for sucrose biosensor fabrication was investigated. Transmission electron microscopy revealed free nanoparticles of various sizes (diameter ~5 to 50 nm) along with clusters of nanogold (~95 to 200 nm) on the surface of inner epidermal membranes of onions (Allium cepa L.). Most of the polydispersed nanoparticles were spherical, although some were square shaped, triangular, hexagonal or rod-shaped. Ultraviolet-visible spectrophotometric observations showed the characteristic peak for nanoparticles decorated invertase-onion membrane at approximately 301 nm. When excited at 320 nm in the presence of sucrose, the membranes exhibited a photoemission peak at 348 nm. The fluorescence lifetime of this nanogold modified onion membrane was 6.20 ns, compared to 2.47 ns for invertase-onion membrane without nanogold. Therefore, a sucrose detection scheme comprised of an invertase/nanogold decorated onion membrane was successfully developed. This fluorescent nanogold-embedded onion membrane drop-test sensor exhibited wide acidic to neutral working pH range (4.0-7.0) with a response time 30 seconds (<1 min). The fabricated quenching-based probe had a low detection limit (2x10(-9) M) with a linear dynamic range of 2.25x10(-9) to 4.25x10(-8) M for sensing sucrose. A microplate designed with an enzyme-nanomaterial-based sensor platform exhibited a high compliance, with acceptable percentage error for the detection of sucrose in green tea samples in comparison to a traditional method. With some further, modifications, this fabricated enzyme-nanogold onion membrane sensor probe could be used to estimate glucose concentrations for a variety of analytical samples. Graphical abstract Synthesis and characterization of invertase assisted nanogold clusters on onion membranes and their application for fluorescence-based sucrose sensor.

  7. Ghrelin O-acyltransferase knockout mice show resistance to obesity when fed high-sucrose diet.

    PubMed

    Kouno, Tetsuya; Akiyama, Nobuteru; Ito, Takahito; Okuda, Tomohiko; Nanchi, Isamu; Notoya, Mitsuru; Oka, Shogo; Yukioka, Hideo

    2016-02-01

    Ghrelin is an appetite-stimulating hormone secreted from stomach. Since the discovery that acylation of the serine-3 residue by ghrelin O-acyltransferase (GOAT) is essential for exerting its functions, GOAT has been regarded as an therapeutic target for attenuating appetite, and thus for the treatment of obesity and diabetes. However, contrary to the expectations, GOAT-knockout (KO) mice have not shown meaningful body weight reduction, under high-fat diet. Here, in this study, we sought to determine whether GOAT has a role in body weight regulation and glucose metabolism with a focus on dietary sucrose, because macronutrient composition of diet is important for appetite regulation. We found that peripherally administered acylated-ghrelin, but not unacylated one, stimulated sucrose consumption in a two-bottle-drinking test. The role of acylated-ghrelin in sucrose preference was further supported by the finding that GOAT KO mice consumed less sucrose solution compared with WT littermates. Then, we investigated the effect of dietary composition of sucrose on food intake and body weight in GOAT KO and WT mice. As a result, when fed on high-fat diet, food intake and body weight were similar between GOAT KO and WT mice. However, when fed on high-fat, high-sucrose diet, GOAT KO mice showed significantly reduced food intake and marked resistance to obesity, leading to amelioration of glucose metabolism. These results suggest that blockade of acylated-ghrelin production offers therapeutic potential for obesity and metabolic disorders caused by overeating of palatable food.

  8. Ketoprofen and antinociception in hypo-oestrogenic Wistar rats fed on a high sucrose diet.

    PubMed

    Jaramillo-Morales, Osmar Antonio; Espinosa-Juárez, Josué Vidal; García-Martínez, Betzabeth Anali; López-Muñoz, Francisco Javier

    2016-10-05

    Non-steroidal anti-inflammatory drugs such as ketoprofen are the most commonly used analgesics for the treatment of pain. However, no studies have evaluated the analgesic response to ketoprofen in conditions of obesity. The aim of this study was to analyse the time course of nociceptive pain in Wistar rats with and without hypo-oestrogenism on a high sucrose diet and to compare the antinociceptive response using ketoprofen. Hypo-oestrogenic and naïve rats received a hyper caloric diet (30% sucrose) or water ad libitum for 17 weeks, the thermal nociception ("plantar test" method) and body weight were tested during this period. A biphasic response was observed: thermal latency decreased in the 4th week (hyperalgesia), while from 12th to 17th week, thermal latency increased (hypoalgesia) in hypo-oestrogenic rats fed with high sucrose diet compared with the hypo-oestrogenic control group. At 4th and 17th weeks, different doses of ketoprofen (1.8-100mg/kg p.o.), were evaluated in all groups. The administration of ketoprofen at 4th and 17th weeks showed dose-dependent effects in the all groups; however, a greater pharmacological efficacy was observed in the 4th week in the hypo-oestrogenic animals that received sucrose. Nevertheless, in all the groups significantly diminish the antinociceptive effects in the 17th week. Our data showed that nociception was altered in the hypo-oestrogenic animals that were fed sucrose (hyperalgesia and hypoalgesia). Ketoprofen showed a dose-dependent antinociceptive effect at both time points. However, hypo-oestrogenism plus high-sucrose diet modifies the antinociceptive effect of ketoprofen.

  9. Trehalulose synthase native and carbohydrate complexed structures provide insights into sucrose isomerization.

    PubMed

    Ravaud, Stéphanie; Robert, Xavier; Watzlawick, Hildegard; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2007-09-21

    Various diseases related to the overconsumption of sugar make a growing need for sugar substitutes. Because sucrose is an inexpensive and readily available d-glucose donor, the industrial potential for enzymatic synthesis of the sucrose isomers trehalulose and/or isomaltulose from sucrose is large. The product specificity of sucrose isomerases that catalyze this reaction depends essentially on the possibility for tautomerization of sucrose, which is required for trehalulose formation. For optimal use of the enzyme, targeting controlled synthesis of these functional isomers, it is necessary to minimize the side reactions. This requires an extensive analysis of substrate binding modes and of the specificity-determining sites in the structure. The 1.6-2.2-A resolution three-dimensional structures of native and mutant complexes of a trehalulose synthase from Pseudomonas mesoacidophila MX-45 mimic successive states of the enzyme reaction. Combined with mutagenesis studies they give for the first time thorough insights into substrate recognition and processing and reaction specificities of these enzymes. Among the important outcomes of this study is the revelation of an aromatic clamp defined by Phe(256) and Phe(280) playing an essential role in substrate recognition and in controlling the reaction specificity, which is further supported by mutagenesis studies. Furthermore, this study highlights essential residues for binding the glucosyl and fructosyl moieties. The introduction of subtle changes informed by comparative three-dimensional structural data observed within our study can lead to fundamental modifications in the mode of action of sucrose isomerases and hence provide a template for industrial catalysts.

  10. Degradation of hydroxycinnamic acid mixtures in aqueous sucrose solutions by the Fenton process.

    PubMed

    Nguyen, Danny M T; Zhang, Zhanying; Doherty, William O S

    2015-02-11

    The degradation efficiencies and behaviors of caffeic acid (CaA), p-coumaric acid (pCoA), and ferulic acid (FeA) in aqueous sucrose solutions containing the mixture of these hydroxycinnamic acids (HCAs) were studied by the Fenton oxidation process. Central composite design and multiresponse surface methodology were used to evaluate and optimize the interactive effects of process parameters. Four quadratic polynomial models were developed for the degradation of each individual acid in the mixture and the total HCAs degraded. Sucrose was the most influential parameter that significantly affected the total amount of HCA degraded. Under the conditions studied there was a <0.01% loss of sucrose in all reactions. The optimal values of the process parameters for a 200 mg/L HCA mixture in water (pH 4.73, 25.15 °C) and sucrose solution (13 mass %, pH 5.39, 35.98 °C) were 77% and 57%, respectively. Regression analysis showed goodness of fit between the experimental results and the predicted values. The degradation behavior of CaA differed from those of pCoA and FeA, where further CaA degradation is observed at increasing sucrose and decreasing solution pH. The differences (established using UV/vis and ATR-FTIR spectroscopy) were because, unlike the other acids, CaA formed a complex with Fe(III) or with Fe(III) hydrogen-bonded to sucrose and coprecipitated with lepidocrocite, an iron oxyhydroxide.

  11. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee.

    PubMed

    Simcock, Nicola K; Gray, Helen E; Wright, Geraldine A

    2014-10-01

    Obtaining the correct balance of nutrients requires that the brain integrates information about the body's nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee's nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1M sucrose or 1M sucrose containing 100mM of isoleucine, proline, phenylalanine, or methionine 24h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously.

  12. High Sucrose Intake Ameliorates the Accumulation of Hepatic Triacylglycerol Promoted by Restraint Stress in Young Rats.

    PubMed

    Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Rodríguez, Ida Soto; Cuevas, Estela; Martínez-Gómez, Margarita; Castelán, Francisco; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2015-11-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. Stress promotes the onset of the NAFLD with a concomitant increment in the activity of the hepatic 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1). However, the interaction between the stress and a carbohydrate-enriched diet for the development of NAFLD in young animals is unknown. In the present study, we evaluated the impact of chronic stress on the hepatic triacylglycerol level of young rats fed or not with a high sucrose-diet. For doing this, 21-day old male Wistar rats were allocated into 4 groups: control (C), chronic restraint stress (St), high-sucrose diet (S30), and chronic restraint stress plus a 30 % sucrose diet (St + S30). Chronic restraint stress consisted of 1-hour daily session, 5 days per week and for 4 weeks. Rats were fed with a standard chow and tap water (C group) or 30 % sucrose diluted in water (S30 group). The St + S30 groups consumed less solid food but had an elevated visceral fat accumulation in comparison with the St group. The St group showed a high level of serum corticosterone and a high activity of the hepatic 11β-HSD-1 concomitantly to the augmentation of hepatic steatosis signs, a high hepatic triacylglycerol content, and hepatic oxidative stress. Conversely, the high-sucrose intake in stressed rats (St + S30 group) reduced the hepatic 11β-HSD-1 activity, the level of serum corticosterone, and the hepatic triacylglycerol content. Present findings show that a high-sucrose diet ameliorates the triacylglycerol accumulation in liver promoted by the restraint stress in young male rats.

  13. A randomized trial of iron isomaltoside versus iron sucrose in patients with iron deficiency anemia.

    PubMed

    Derman, Richard; Roman, Eloy; Modiano, Manuel R; Achebe, Maureen M; Thomsen, Lars L; Auerbach, Michael

    2017-03-01

    Iron deficiency anemia (IDA) is common in many chronic diseases, and intravenous (IV) iron offers a rapid and efficient iron correction. This trial compared the efficacy and safety of iron isomaltoside and iron sucrose in patients with IDA who were intolerant of, or unresponsive to, oral iron. The trial was an open-label, comparative, multi-center trial. Five hundred and eleven patients with IDA from different causes were randomized 2:1 to iron isomaltoside or iron sucrose and followed for 5 weeks. The cumulative dose of iron isomaltoside was based on body weight and hemoglobin (Hb), administered as either a 1000 mg infusion over more than 15 minutes or 500 mg injection over 2 minutes. The cumulative dose of iron sucrose was calculated according to Ganzoni and administered as repeated 200 mg infusions over 30 minutes. The mean cumulative dose of iron isomaltoside was 1640.2 (standard deviation (SD): 357.6) mg and of iron sucrose 1127.9 (SD: 343.3) mg. The primary endpoint was the proportion of patients with a Hb increase ≥2 g/dL from baseline at any time between weeks 1-5. Both non-inferiority and superiority were confirmed for the primary endpoint, and a shorter time to Hb increase ≥2 g/dL was observed with iron isomaltoside. For all biochemical efficacy parameters, faster and/or greater improvements were found with iron isomaltoside. Both treatments were well tolerated; 0.6% experienced a serious adverse drug reaction. Iron isomaltoside was more effective than iron sucrose in achieving a rapid improvement in Hb. Furthermore, iron isomaltoside has an advantage over iron sucrose in allowing higher cumulative dosing in fewer administrations. Both treatments were well tolerated in a broad population with IDA.

  14. Assessment of sucrose and ethanol reinforcement: the across-session breakpoint procedure.

    PubMed

    Czachowski, Cristine L; Legg, Brooke H; Samson, Herman H

    2003-01-01

    We have demonstrated previously that the use of an across-session progressive ratio procedure yields breakpoint values for 10% ethanol (10E) that are stable and comparable to those measured for other drugs of abuse [Alcohol. Clin. Exp. Res. 23 (1999) 1580]. The aims of the present experiment were twofold: (1). to determine whether this procedure is sensitive to changes in reinforcer magnitude using a reinforcer previously demonstrated to affect operant responding in a predictable fashion and (2). to determine whether ethanol reinforcement produced similar changes in behavior. Male, Long-Evans rats were trained to respond for either 3% sucrose (3S) or 10E using the sipper tube appetitive/consummatory procedure where the completion of a single response requirement results in access to a liquid solution for 20 min. Three successive breakpoints were determined for this "baseline" solution by increasing the response requirement each day until it was not completed. The concentration of the solutions was then manipulated such that breakpoints for the Sucrose Group were assessed for 1%, 3%, 5% and 10% sucrose, and breakpoints for the Ethanol Group were assessed for 2%, 5%, 10% and 20% ethanol. The concentration manipulation showed that sucrose concentration had a greater impact on seeking and consumption than did ethanol concentration. Breakpoints in the Sucrose Group were highly correlated with sucrose concentration, whereas in the Ethanol Group, breakpoint was unrelated to ethanol concentration. Ethanol intake patterns suggested that pharmacological factors might have been regulating intake, and that when physiologically detectable amounts of ethanol were consumed, there was a dissociation between seeking and intake with slightly elevated ethanol seeking. Overall, the across-session breakpoint procedure confirmed that sweet taste was highly related to seeking and consumption, whereas ethanol-motivated responding may be controlled by different regulatory mechanisms that

  15. Single amino acids in sucrose rewards modulate feeding and associative learning in the honeybee

    PubMed Central

    Simcock, Nicola K.; Gray, Helen E.; Wright, Geraldine A.

    2014-01-01

    Obtaining the correct balance of nutrients requires that the brain integrates information about the body’s nutritional state with sensory information from food to guide feeding behaviour. Learning is a mechanism that allows animals to identify cues associated with nutrients so that they can be located quickly when required. Feedback about nutritional state is essential for nutrient balancing and could influence learning. How specific this feedback is to individual nutrients has not often been examined. Here, we tested how the honeybee’s nutritional state influenced the likelihood it would feed on and learn sucrose solutions containing single amino acids. Nutritional state was manipulated by pre-feeding bees with either 1 M sucrose or 1 M sucrose containing 100 mM of isoleucine, proline, phenylalanine, or methionine 24 h prior to olfactory conditioning of the proboscis extension response. We found that bees pre-fed sucrose solution consumed less of solutions containing amino acids and were also less likely to learn to associate amino acid solutions with odours. Unexpectedly, bees pre-fed solutions containing an amino acid were also less likely to learn to associate odours with sucrose the next day. Furthermore, they consumed more of and were more likely to learn when rewarded with an amino acid solution if they were pre-fed isoleucine and proline. Our data indicate that single amino acids at relatively high concentrations inhibit feeding on sucrose solutions containing them, and they can act as appetitive reinforcers during learning. Our data also suggest that select amino acids interact with mechanisms that signal nutritional sufficiency to reduce hunger. Based on these experiments, we predict that nutrient balancing for essential amino acids during learning requires integration of information about several amino acids experienced simultaneously. PMID:24819203

  16. Dolomite Dissolution in Alkaline Cementious Media

    NASA Astrophysics Data System (ADS)

    Mittermayr, Florian; Klammer, Dietmar; Köhler, Stephan; Dietzel, Martin

    2010-05-01

    Chemical alteration of concrete has gained much attention over the past years as many cases of deterioration due to sulphate attack, thaumasite formation (TSA) or alkali silica reactions (ASR) have been reported in various constructions (Schmidt et al, 2009). Much less is known about the so called alkali carbonate reaction (ACR). It is believed that dolomite aggregates can react with the alkalis from the cement, dissolve and form calcite and brucite (Katayama, 2004). Due to very low solubility of dolomite in alkaline solutions this reaction seems doubtful. In this study we are trying to gain new insides about the conditions that can lead to the dissolution of dolomite in concrete. Therefore we investigated concrete samples from Austrian tunnels that show partially dissolved dolomite aggregates. Petrological analysis such as microprobe, SEM and Raman spectroscopy as well as a hydrochemical analysis of interstitial solutions and ground water and modelling with PhreeqC (Parkhurst and Appelo, 1999) are carried out. In addition a series of batch experiments is set up. Modelling approaches by PhreeqC show a thermodynamically possibility in the alkaline range when additional Ca2+ in solution causes dolomite to become more and more undersaturated as calcite gets supersaturated. Interacting ground water is enriched in Ca2+and saturated with respect to gypsum as marine evaporites are found in situ rocks. Furthermore it is more likely that Portlandite (Ca(OH)2) plays a more important role than Na and K in the cement. Portlandite acts as an additional Ca2+ source and is much more abundant than the alkalies. Some interstitial solutions are dominated mainly by Na+ and SO42- and reach concentrations up to 30 g/l TDS. It is believed that solutions can even reach thenardite saturation as efflorescences are found on the tunnel walls. In consequence dolomite solubility increases with increasing ionic strength. pH > 11 further accelerate the process of dedolomitization by the removal

  17. Transforming a Fructan:Fructan 6G-Fructosyltransferase from Perennial Ryegrass into a Sucrose:Sucrose 1-Fructosyltransferase1[C

    PubMed Central

    Lasseur, Bertrand; Schroeven, Lindsey; Lammens, Willem; Le Roy, Katrien; Spangenberg, German; Manduzio, Hélène; Vergauwen, Rudy; Lothier, Jérémy; Prud'homme, Marie-Pascale; Van den Ende, Wim

    2009-01-01

    Fructosyltransferases (FTs) synthesize fructans, fructose polymers accumulating in economically important cool-season grasses and cereals. FTs might be crucial for plant survival under stress conditions in species in which fructans represent the major form of reserve carbohydrate, such as perennial ryegrass (Lolium perenne). Two FT types can be distinguished: those using sucrose (S-type enzymes: sucrose:sucrose 1-fructosyltransferase [1-SST], sucrose:fructan 6-fructosyltransferase) and those using fructans (F-type enzymes: fructan:fructan 1-fructosyltransferase [1-FFT], fructan:fructan 6G-fructosyltransferase [6G-FFT]) as preferential donor substrate. Here, we report, to our knowledge for the first time, the transformation of an F-type enzyme (6G-FFT/1-FFT) into an S-type enzyme (1-SST) using perennial ryegrass 6G-FFT/1-FFT (Lp6G-FFT/1-FFT) and 1-SST (Lp1-SST) as model enzymes. This transformation was accomplished by mutating three amino acids (N340D, W343R, and S415N) in the vicinity of the active site of Lp6G-FFT/1-FFT. In addition, effects of each amino acid mutation alone or in combination have been studied. Our results strongly suggest that the amino acid at position 343 (tryptophan or arginine) can greatly determine the donor substrate characteristics by influencing the position of the amino acid at position 340. Moreover, the presence of arginine-343 negatively affects the formation of neofructan-type linkages. The results are compared with recent findings on donor substrate selectivity within the group of plant cell wall invertases and fructan exohydrolases. Taken together, these insights contribute to our knowledge of structure/function relationships within plant family 32 glycosyl hydrolases and open the way to the production of tailor-made fructans on a larger scale. PMID:18952861

  18. Hunger and negative alliesthesia to aspartame and sucrose in patients treated with antipsychotic drugs and controls.

    PubMed

    Khazaal, Y; Chatton, A; Claeys, F; Ribordy, F; Khan, R; Zullino, D

    2009-12-01

    The present study explores sweet stimuli effects on hunger and negative alliesthesia in patients treated with antipsychotic drugs and controls. Those phenomena were examined in relation to previous weight gain, eating and weight-related cognitions and type of sweet stimuli: aspartame or sucrose. Alliesthesia is delayed in participants who gained weight regardless of cross group differences. A similar reduction of hunger was observed after the intake of two kinds of sweet stimuli (aspartame or sucrose) whereas alliesthesia measures were not affected. Whereas atypical antipsychotic drug-induced weight gain is linked to delayed satiety, the phenomenon is similar in magnitude in non-psychiatric controls who gained weight.

  19. A vicilin-like seed protein of cycads: similarity to sucrose-binding proteins.

    PubMed

    Braun, H; Czihal, A; Shutov, A D; Bäumlein, H

    1996-04-01

    Seed storage globulins of the 7S and 11S type are synthesized in the seeds of angiosperms and gymnosperms. We have isolated and characterized a vicilin-like gene expressed in the cycad Zamia furfuraceae. Sequence comparisons reveal clear similarities to a sucrose-binding protein isolated from soybean. We suggest the existence of a superfamily of related genes including both vicilin-like and legumin-like seed globulin genes as well as genes coding for spherulins, germins and sucrose-binding-proteins.

  20. Correlation between caries incidence and frequency of chewing gum sweetened with sucrose or xylitol.

    PubMed

    Rekola, M

    1989-01-01

    The effect on caries incidence of the daily consumption of chewing gum sweetened with sucrose or xylitol was measured in 100 subjects included in the 1-year chewing gum study (Scheinin et al. 1975, Turku sugar Studies XVIII). The subjects were divided retrospectively into groups consuming 2-8 chewing gum pieces per day and their caries incidence was compared. With chewing gum sweetened with sucrose, the caries incidence increased in relation to the daily consumption of gum. In contrast, chewing gum sweetened with xylitol reduced the incidence of caries with increasing consumption.