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Sample records for solution sorbitol molecules

  1. Theoretical investigation of interaction of sorbitol molecules with alcohol dehydrogenase in aqueous solution using molecular dynamics simulation.

    Science.gov (United States)

    Bahrami, Homayoon; Zahedi, Mansour; Moosavi-Movahedi, Ali Akbar; Azizian, Homa; Amanlou, Massoud

    2011-03-01

    The nature of protein-sorbitol-water interaction in solution at the molecular level, has been investigated using molecular dynamics simulations. In order to do this task, two molecular dynamics simulations of the protein ADH in solution at room temperature have been carried out, one in the presence (about 0.9 M) and another in the absence of sorbitol. The results show that the sorbitol molecules cluster and move toward the protein, and form hydrogen bonds with protein. Also, coating by sorbitol reduces the conformational fluctuations of the protein compared to the sorbitol-free system. Thus, it is concluded that at moderate concentration of sorbitol solution, sorbitol molecules interact with ADH via many H-bonds that prevent the protein folding. In fact, at more concentrated sorbitol solution, water and sorbitol molecules accumulate around the protein surface and form a continuous space-filling network to reduce the protein flexibility. Namely, in such solution, sorbitol molecules can stabilize a misfolded state of ADH, and prevent the protein from folding to its native structure.

  2. The Interaction of Sorbitol with Caffeine in Aqueous Solution.

    Science.gov (United States)

    Tavagnacco, Letizia; Brady, John W; Cesàro, Attilio

    2013-09-01

    Molecular dynamics simulations were carried out on a system of caffeine interacting with the sugar alcohol sorbitol. The system examined had a caffeine concentration 0.083 m and a sugar concentration 1.08 m. The trajectories of all molecules in the system were collected over a period of 80 ns and analyzed to determine whether there is any tendency for sorbitol to bind to caffeine, and if so, by what mechanism. The results show that the sorbitol molecules have an affinity for the caffeine molecules and that the binding occurred by the interaction of the aliphatic hydrophobic protons of the sugar with the caffeine face. This intermolecular association via face-to-face stacking, as suggested by simulation studies, is similar to that found for sucrose and for D-glucose, which overwhelmingly exists in the pyranose ring chair form in aqueous solution, as well as for caffeine-caffeine association. The sorbitol molecules, however, exist as relatively extended chains and are, therefore, topologically quite different from the sugars sucrose and glucose. The comparison of the average conformation of sorbitol molecules bound to caffeine with that of molecules in the free state shows a substantial similarity.

  3. The Interaction of Sorbitol with Caffeine in Aqueous Solution

    OpenAIRE

    Tavagnacco, Letizia; Brady, John W.; Cesàro, Attilio

    2013-01-01

    Molecular dynamics simulations were carried out on a system of caffeine interacting with the sugar alcohol sorbitol. The system examined had a caffeine concentration 0.083 m and a sugar concentration 1.08 m. The trajectories of all molecules in the system were collected over a period of 80 ns and analyzed to determine whether there is any tendency for sorbitol to bind to caffeine, and if so, by what mechanism. The results show that the sorbitol molecules have an affinity for the caffeine mole...

  4. The vapour pressure of water as a function of solute concentration above aqueous solutions of fructose, sucrose, raffinose, erythritol, xylitol, and sorbitol

    DEFF Research Database (Denmark)

    Cooke, S.A.; Jonsdottir, Svava Osk; Westh, Peter

    2002-01-01

    The vapour pressure of water above an aqueous solution of sucrose at T = 298.06 K has been measured for 9 sucrose mole fractions up to 0.12. Vapour pressure measurements have also been made on aqueous solutions of meso-erythritol, xylitol, sorbitol, fructose, and raffinose at T = 317.99 K...

  5. Energetics of the molecular interactions of L-alanine and L-serine with xylitol, D-sorbitol, and D-mannitol in aqueous solutions at 298.15 K

    Science.gov (United States)

    Mezhevoi, I. N.; Badelin, V. G.

    2013-04-01

    Integral enthalpies of dissolution Δsol H m of L-alanine and L-serine are measured via the calorimetry of dissolution in aqueous solutions of xylitol, D-sorbitol, and D-mannitol. Standard enthalpies of dissolution (Δsol H ○) and the transfer (Δtr H ○) of amino acids from water to binary solvent are calculated from the experimental data. Using the McMillan-Mayer theory, enthalpy coefficients of pairwise interactions h xy of amino acids with molecules of polyols are calculated that are negative. The obtained results are discussed within the theory of the prevalence of different types of interactions in mixed solutions and the effect of the structural features of interacting biomolecules on the thermochemical parameters of dissolution of amino acids.

  6. Comparison of Intermolecular Forces in Anhydrous Sorbitol and Solvent Cocrystals.

    Science.gov (United States)

    Dierks, Teresa M; Korter, Timothy M

    2017-08-03

    The hygroscopicity of solid sorbitol is important for its utilization as a sweetener in the pharmaceutical and food industries. The molecular foundations of sorbitol hydration characteristics are explored here using two solvated cocrystals, sorbitol-water and sorbitol-pyridine. In this work, solid-state density functional theory and terahertz time-domain spectroscopy were used to evaluate the relative stabilities of these cocrystals as compared to anhydrous sorbitol in terms of conformational and cohesive energies. The modification of the hydrogen-bonding network in crystalline sorbitol by solvent molecules gives new insight into the origins of the notable stability of sorbitol-water as compared to similar solids such as mannitol-water. In particular, the energy analysis reveals that the relative instability of the mannitol hydrate is based primarily in the lack of water-water interactions which provide considerable stabilization in the sorbitol-water crystal.

  7. Electron impact ionization of the gas-phase sorbitol

    Science.gov (United States)

    Chernyshova, Irina; Markush, Pavlo; Zavilopulo, Anatoly; Shpenik, Otto

    2015-03-01

    Ionization and dissociative ionization of the sorbitol molecule by electron impact have been studied using two different experimental methods. In the mass range of m/ z = 10-190, the mass spectra of sorbitol were recorded at the ionizing electron energies of 70 and 30 eV. The ion yield curves for the fragment ions have been analyzed and the appearance energies of these ions have been determined. The relative total ionization cross section of the sorbitol molecule was measured using monoenergetic electron beam. Possible fragmentation pathways for the sorbitol molecule were proposed.

  8. Protein crowding in solution, frozen and freeze-dried states: small-angle neutron and X-ray scattering study of lysozyme/sorbitol/water systems

    Science.gov (United States)

    Krueger, Susan; Khodadadi, Sheila; Clark, Nicholas; McAuley, Arnold; Cristiglio, Viviana; Theyencheri, Narayanan; Curtis, Joseph; Shalaev, Evgenyi

    2015-03-01

    For effective preservation, proteins are often stored as frozen solutions or in glassy states using a freeze-drying process. However, aggregation is often observed after freeze-thaw or reconstitution of freeze-dried powder and the stability of the protein is no longer assured. In this study, small-angle neutron and X-ray scattering (SANS and SAXS) have been used to investigate changes in protein-protein interaction distances of a model protein/cryoprotectant system of lysozyme/sorbitol/water, under representative pharmaceutical processing conditions. The results demonstrate the utility of SAXS and SANS methods to monitor protein crowding at different stages of freezing and drying. The SANS measurements of solution samples showed at least one protein interaction peak corresponding to an interaction distance of ~ 90 Å. In the frozen state, two protein interaction peaks were observed by SANS with corresponding interaction distances at 40 Å as well as 90 Å. On the other hand, both SAXS and SANS data for freeze-dried samples showed three peaks, suggesting interaction distances ranging from ~ 15 Å to 170 Å. Possible interpretations of these interaction peaks will be discussed, as well as the role of sorbitol as a cryoprotectant during the freezing and drying process.

  9. Effects of sorbitol and glycerol on the structure, dynamics, and stability of Mycobacterium tuberculosis pyrazinamidase

    Directory of Open Access Journals (Sweden)

    Mehrnoosh Khajehzadeh

    2016-01-01

    Conclusion: It can be concluded that the native conformation of the enzyme was stabilized in the sorbitol and glycerol and tend to exclude from the PZase surface, forcing the enzyme to keep it in the compactly folded conformation. The glycerol molecules stabilized PZase by decreasing the loops flexibility and then compacting the enzyme structure. It appears that more stability of PZase in glycerol solution correlates with its amphiphilic orientation, which decreases the unfavorable interactions of hydrophobic regions.

  10. Structure elucidation and quantification of impurities formed between 6-aminocaproic acid and the excipients citric acid and sorbitol in an oral solution using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Schou-Pedersen, Anne Marie V; Cornett, Claus; Nyberg, Nils

    2015-01-01

    Concentrated solutions containing 6-aminocaproic acid and the excipients citric acid and sorbitol have been studied at temperatures of 50 °C, 60 °C, 70 °C and 80 °C as well as at 20 °C. It has previously been reported that the commonly employed citric acid is a reactive excipient, and it is there......Concentrated solutions containing 6-aminocaproic acid and the excipients citric acid and sorbitol have been studied at temperatures of 50 °C, 60 °C, 70 °C and 80 °C as well as at 20 °C. It has previously been reported that the commonly employed citric acid is a reactive excipient...... and cyclized 6-aminocaproic acid, i.e., caprolactam. No reaction products between d-sorbitol and 6-aminocaproic acid could be observed. 3-Hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid, dimer and caprolactam were also observed after storage at 20 °C for 3 months. The findings imply that an oral solution of 6...

  11. Polyol specificity of recombinant Arabidopsis thaliana sorbitol dehydrogenase studied by enzyme kinetics and in silico modeling

    Directory of Open Access Journals (Sweden)

    María Francisca eAguayo

    2015-02-01

    Full Text Available Polyols are enzymatically-produced plant compounds which can act as compatible solutes during periods of abiotic stress. NAD+-dependent SORBITOL DEHYDROGENASE (SDH, E.C. 1.1.1.14 from Arabidopsis thaliana L. (AtSDH is capable of oxidizing several polyols including sorbitol, ribitol and xylitol. In the present study, enzymatic assays using recombinant AtSDH demonstrated a higher specificity constant for xylitol compared to sorbitol and ribitol, all of which are C2 (S and C4 (R polyols. Enzyme activity was reduced by preincubation with ethylenediaminetetraacetic acid (EDTA, indicating a requirement for zinc ions. In humans, it has been proposed that sorbitol becomes part of a pentahedric coordination sphere of the catalytic zinc during the reaction mechanism. In order to determine the validity of this pentahedric coordination model in a plant SDH, homology modeling and Molecular Dynamics simulations of AtSDH ternary complexes with the three polyols were performed using crystal structures of human and Bemisia argentifolii (Genn. (Hemiptera: Aleyrodidae SDHs as scaffolds. The results indicate that the differences in interaction with structural water molecules correlate very well with the observed enzymatic parameters, validate the proposed pentahedric coordination of the catalytic zinc ion in a plant SDH, and provide an explanation for why AtSDH shows a preference for polyols with a chirality of C2 (S and C4 (R.

  12. Colon Necrosis Due to Sodium Polystyrene Sulfonate with and without Sorbitol: An Experimental Study in Rats.

    Science.gov (United States)

    Ayoub, Isabelle; Oh, Man S; Gupta, Raavi; McFarlane, Michael; Babinska, Anna; Salifu, Moro O

    2015-01-01

    Based on a single rat study by Lillemoe et al, the consensus has been formed to implicate sorbitol rather than sodium polystyrene sulfonate (SPS) as the culprit for colon necrosis in humans treated with SPS and sorbitol. We tested the hypothesis that colon necrosis by sorbitol in the experiment was due to the high osmolality and volume of sorbitol rather than its chemical nature. 26 rats underwent 5/6 nephrectomy. They were divided into 6 groups and given enema solutions under anesthesia (normal saline, 33% sorbitol, 33% mannitol, SPS in 33% sorbitol, SPS in normal saline, and SPS in distilled water). They were sacrificed after 48 hours of enema administration or earlier if they were very sick. The gross appearance of the colon was visually inspected, and then sliced colon tissues were examined under light microscopy. 1 rat from the sorbitol and 1 from the mannitol group had foci of ischemic colonic changes. The rats receiving SPS enema, in sorbitol, normal saline, distilled water, had crystal deposition with colonic necrosis and mucosal erosion. All the rats not given SPS survived until sacrificed at 48 h whereas 11 of 13 rats that received SPS in sorbitol, normal saline or distilled water died or were clearly dying and sacrificed sooner. There was no difference between sorbitol and mannitol when given without SPS. In a surgical uremic rat model, SPS enema given alone or with sorbitol or mannitol seemed to cause colon necrosis and high mortality rate, whereas 33% sorbitol without SPS did not.

  13. Overexpression, purification and crystallization of the tetrameric form of SorC sorbitol operon regulator

    International Nuclear Information System (INIS)

    Sanctis, Daniele de; Rêgo, Ana T.; Marçal, David; McVey, Colin E.; Carrondo, Maria A.; Enguita, Francisco J.

    2007-01-01

    The sorbitol operon regulator from K. pneumoniae has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 3.2 Å. The sorbitol operon regulator (SorC) regulates the metabolism of l-sorbose in Klebsiella pneumonia. SorC was overexpressed in Escherichia coli and purified, and crystals were obtained of a tetrameric form. A single crystal showed X-ray diffraction to 3.20 Å. The crystal belongs to space group P2 1 2 1 2 1 , with unit-cell parameters a = 91.6, b = 113.3, c = 184.1 Å. Analysis of the molecular-replacement solution indicates the presence of four SorC molecules in the asymmetric unit

  14. Lattice diffusion of a single molecule in solution

    Science.gov (United States)

    Ruggeri, Francesca; Krishnan, Madhavi

    2017-12-01

    The ability to trap a single molecule in an electrostatic potential well in solution has opened up new possibilities for the use of molecular electrical charge to study macromolecular conformation and dynamics at the level of the single entity. Here we study the diffusion of a single macromolecule in a two-dimensional lattice of electrostatic traps in solution. We report the ability to measure both the size and effective electrical charge of a macromolecule by observing single-molecule transport trajectories, typically a few seconds in length, using fluorescence microscopy. While, as shown previously, the time spent by the molecule in a trap is a strong function of its effective charge, we demonstrate here that the average travel time between traps in the landscape yields its hydrodynamic radius. Tailoring the pitch of the lattice thus yields two different experimentally measurable time scales that together uniquely determine both the size and charge of the molecule. Since no information is required on the location of the molecule between consecutive departure and arrival events at lattice sites, the technique is ideally suited to measurements on weakly emitting entities such as single molecules.

  15. Time Resolved X-Ray Scattering of molecules in Solution

    DEFF Research Database (Denmark)

    Brandt van Driel, Tim

    The dissertation describes the use of Time-Resolved X-ray Diffuse Scattering (TR-XDS) to study photo-induced structural changes in molecules in solution. The application of the technique is exemplified with experiments on two bimetallic molecules. The main focus is on the data-flow and process......)42+ obtained at European Synchrotron Radiation Facility (ESRF) are presented to exemplify TR-XDS at synchrotrons. Similarly, measurements on Ir2(dimen)42+ are used to show the XFEL data-flow and how it deviates from the prior. A method to identify and account for systematic fluctuations...

  16. Integrated Computational Solution for Predicting Skin Sensitization Potential of Molecules.

    Directory of Open Access Journals (Sweden)

    Konda Leela Sarath Kumar

    Full Text Available Skin sensitization forms a major toxicological endpoint for dermatology and cosmetic products. Recent ban on animal testing for cosmetics demands for alternative methods. We developed an integrated computational solution (SkinSense that offers a robust solution and addresses the limitations of existing computational tools i.e. high false positive rate and/or limited coverage.The key components of our solution include: QSAR models selected from a combinatorial set, similarity information and literature-derived sub-structure patterns of known skin protein reactive groups. Its prediction performance on a challenge set of molecules showed accuracy = 75.32%, CCR = 74.36%, sensitivity = 70.00% and specificity = 78.72%, which is better than several existing tools including VEGA (accuracy = 45.00% and CCR = 54.17% with 'High' reliability scoring, DEREK (accuracy = 72.73% and CCR = 71.44% and TOPKAT (accuracy = 60.00% and CCR = 61.67%. Although, TIMES-SS showed higher predictive power (accuracy = 90.00% and CCR = 92.86%, the coverage was very low (only 10 out of 77 molecules were predicted reliably.Owing to improved prediction performance and coverage, our solution can serve as a useful expert system towards Integrated Approaches to Testing and Assessment for skin sensitization. It would be invaluable to cosmetic/ dermatology industry for pre-screening their molecules, and reducing time, cost and animal testing.

  17. 21 CFR 184.1835 - Sorbitol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sorbitol. 184.1835 Section 184.1835 Food and Drugs... Substances Affirmed as GRAS § 184.1835 Sorbitol. (a) Sorbitol is the chemical 1,2,3,4,5,6-hexanehexol.... Sorbitol is produced by the electrolytic reduction, or the transition metal catalytic hydrogenation of...

  18. X-ray crystal structure and small-angle X-ray scattering of sheep liver sorbitol dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Yennawar, Hemant [Pennsylvania State University, 8 Althouse Laboratory, University Park, PA 16802 (United States); Møller, Magda [Cornell High Energy Synchrotron Source, Ithaca, NY 14853 (United States); University of Copenhagen, DK-2100 Copenhagen (Denmark); Gillilan, Richard [Cornell High Energy Synchrotron Source, Ithaca, NY 14853 (United States); Yennawar, Neela, E-mail: nhy1@psu.edu [Pennsylvania State University, 8 Althouse Laboratory, University Park, PA 16802 (United States)

    2011-05-01

    The X-ray crystal structure and a small-angle X-ray scattering solution structure of sheep liver sorbitol dehydrogenase have been determined. The details of the interactions that enable the tetramer scaffold to be the functional biological unit have been analyzed. The X-ray crystal structure of sheep liver sorbitol dehydrogenase (slSDH) has been determined using the crystal structure of human sorbitol dehydrogenase (hSDH) as a molecular-replacement model. slSDH crystallized in space group I222 with one monomer in the asymmetric unit. A conserved tetramer that superposes well with that seen in hSDH (despite belonging to a different space group) and obeying the 222 crystal symmetry is seen in slSDH. An acetate molecule is bound in the active site, coordinating to the active-site zinc through a water molecule. Glycerol, a substrate of slSDH, also occupies the substrate-binding pocket together with the acetate designed by nature to fit large polyol substrates. The substrate-binding pocket is seen to be in close proximity to the tetramer interface, which explains the need for the structural integrity of the tetramer for enzyme activity. Small-angle X-ray scattering was also used to identify the quaternary structure of the tetramer of slSDH in solution.

  19. The effects of xylitol and sorbitol on lysozyme- and peroxidase-related enzymatic and candidacidal activities.

    Science.gov (United States)

    Kim, Bum-Soo; Chang, Ji-Youn; Kim, Yoon-Young; Kho, Hong-Seop

    2015-07-01

    To investigate whether xylitol and sorbitol affect enzymatic and candidacidal activities of lysozyme, the peroxidase system, and the glucose oxidase-mediated peroxidase system. Xylitol and sorbitol were added to hen egg-white lysozyme, bovine lactoperoxidase, glucose oxidase-mediated peroxidase, and whole saliva in solution and on hydroxyapatite surfaces. The enzymatic activities of lysozyme, peroxidase, and glucose oxidase-mediated peroxidase were determined by the turbidimetric method, the NbsSCN assay, and production of oxidized o-dianisidine, respectively. Candidacidal activities were determined by comparing colony forming units using Candida albicans ATCC strains 10231, 11006, and 18804. While xylitol and sorbitol did not affect the enzymatic activity of hen egg-white lysozyme both in solution and on hydroxyapatite surfaces, they did inhibit the enzymatic activity of salivary lysozyme significantly in solution, but not on the surfaces. Xylitol and sorbitol enhanced the enzymatic activities of both bovine lactoperoxidase and salivary peroxidase significantly in a dose-dependent manner in solution, but not on the surfaces. Sorbitol, but not xylitol, inhibited the enzymatic activity of glucose oxidase-mediated peroxidase significantly. Both xylitol and sorbitol did not affect candidacidal activities of hen egg-white lysozyme, the bovine lactoperoxidase system, or the glucose oxidase-mediated bovine lactoperoxidase system. Xylitol and sorbitol inhibited salivary lysozyme activity, but enhanced both bovine lactoperoxidase and salivary peroxidase activities significantly in solution. Xylitol and sorbitol did not augment lysozyme- and peroxidase-related candidacidal activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Structure elucidation and quantification of impurities formed between 6-aminocaproic acid and the excipients citric acid and sorbitol in an oral solution using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Schou-Pedersen, Anne Marie V; Cornett, Claus; Nyberg, Nils; Østergaard, Jesper; Hansen, Steen Honoré

    2015-03-25

    Concentrated solutions containing 6-aminocaproic acid and the excipients citric acid and sorbitol have been studied at temperatures of 50°C, 60°C, 70°C and 80°C as well as at 20°C. It has previously been reported that the commonly employed citric acid is a reactive excipient, and it is therefore important to thoroughly investigate a possible reaction between 6-aminocaproic acid and citric acid. The current study revealed the formation of 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid between 6-aminocaproic acid and citric acid by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance spectroscopy (NMR). Less than 0.03% of 6-aminocaproic acid was converted to 3-hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid after 30 days of storage at 80°C. Degradation products of 6-aminocaproic acid were also observed after storage at the applied temperatures, e.g., dimer, trimer and cyclized 6-aminocaproic acid, i.e., caprolactam. No reaction products between D-sorbitol and 6-aminocaproic acid could be observed. 3-Hydroxy-3,4-dicarboxy-butanamide-N-hexanoic acid, dimer and caprolactam were also observed after storage at 20°C for 3 months. The findings imply that an oral solution of 6-aminocaproic acid is relatively stable at 20°C at the pH values 4.00 and 5.00 as suggested in the USP for oral formulations. Compliance with the ICH guideline Q3B is expected. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. High performance photovoltaic applications using solution-processed small molecules.

    Science.gov (United States)

    Chen, Yongsheng; Wan, Xiangjian; Long, Guankui

    2013-11-19

    Energy remains a critical issue for the survival and prosperity of humancivilization. Many experts believe that the eventual solution for sustainable energy is the use of direct solar energy as the main energy source. Among the options for renewable energy, photovoltaic technologies that harness solar energy offer a way to harness an unlimited resource and minimum environment impact in contrast with other alternatives such as water, nuclear, and wind energy. Currently, almost all commercial photovoltaic technologies use Si-based technology, which has a number of disadvantages including high cost, lack of flexibility, and the serious environmental impact of the Si industry. Other technologies, such as organic photovoltaic (OPV) cells, can overcome some of these issues. Today, polymer-based OPV (P-OPV) devices have achieved power conversion efficiencies (PCEs) that exceed 9%. Compared with P-OPV, small molecules based OPV (SM-OPV) offers further advantages, including a defined structure for more reproducible performance, higher mobility and open circuit voltage, and easier synthetic control that leads to more diversified structures. Therefore, while largely undeveloped, SM-OPV is an important emerging technology with performance comparable to P-OPV. In this Account, we summarize our recent results on solution-processed SM-OPV. We believe that solution processing is essential for taking full advantage of OPV technologies. Our work started with the synthesis of oligothiophene derivatives with an acceptor-donor-acceptor (A-D-A) structure. Both the backbone conjugation length and electron withdrawing terminal groups play an important role in the light absorption, energy levels and performance of the devices. Among those molecules, devices using a 7-thiophene-unit backbone and a 3-ethylrhodanine (RD) terminal unit produced a 6.1% PCE. With the optimized conjugation length and terminal unit, we borrowed from the results with P-OPV devices to optimize the backbone. Thus we

  2. 75 FR 39277 - Sorbitol From France; Determination

    Science.gov (United States)

    2010-07-08

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-44 (Third Review)] Sorbitol From France... U.S.C. 1675d(c)) (the Act), that revocation of the antidumping duty order on sorbitol from France... views of the Commission are contained in USITC Publication 4164 (June 2010), entitled Sorbitol from...

  3. 21 CFR 582.5835 - Sorbitol.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sorbitol. 582.5835 Section 582.5835 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... § 582.5835 Sorbitol. (a) Product. Sorbitol. (b) Conditions of use. This substance is generally...

  4. Structural characterization of the thermostable Bradyrhizobium japonicumD-sorbitol dehydrogenase.

    Science.gov (United States)

    Fredslund, Folmer; Otten, Harm; Gemperlein, Sabrina; Poulsen, Jens Christian N; Carius, Yvonne; Kohring, Gert Wieland; Lo Leggio, Leila

    2016-11-01

    Bradyrhizobium japonicum sorbitol dehydrogenase is NADH-dependent and is active at elevated temperatures. The best substrate is D-glucitol (a synonym for D-sorbitol), although L-glucitol is also accepted, giving it particular potential in industrial applications. Crystallization led to a hexagonal crystal form, with crystals diffracting to 2.9 Å resolution. In attempts to phase the data, a molecular-replacement solution based upon PDB entry 4nbu (33% identical in sequence to the target) was found. The solution contained one molecule in the asymmetric unit, but a tetramer similar to that found in other short-chain dehydrogenases, including the search model, could be reconstructed by applying crystallographic symmetry operations. The active site contains electron density consistent with D-glucitol and phosphate, but there was not clear evidence for the binding of NADH. In a search for the features that determine the thermostability of the enzyme, the T m for the orthologue from Rhodobacter sphaeroides, for which the structure was already known, was also determined, and this enzyme proved to be considerably less thermostable. A continuous β-sheet is formed between two monomers in the tetramer of the B. japonicum enzyme, a feature not generally shared by short-chain dehydrogenases, and which may contribute to thermostability, as may an increased Pro/Gly ratio.

  5. A fiber-optic sorbitol biosensor based on NADH fluorescence detection toward rapid diagnosis of diabetic complications.

    Science.gov (United States)

    Gessei, Tomoko; Arakawa, Takahiro; Kudo, Hiroyuki; Mitsubayashi, Kohji

    2015-09-21

    Accumulation of sorbitol in the tissue is known to cause microvascular diabetic complications. In this paper, a fiber-optic biosensor for sorbitol which is used as a biomarker of diabetic complications was developed and tested. The biosensor used a sorbitol dehydrogenase from microorganisms of the genus Flavimonas with high substrate specificity and detected the fluorescence of reduced nicotinamide adenine dinucleotide (NADH) by the enzymatic reaction. An ultraviolet light emitting diode (UV-LED) was used as the excitation light source of NADH. The fluorescence of NADH was detected using a spectrometer or a photomultiplier tube (PMT). The UV-LED and the photodetector were coupled using a Y-shaped optical fiber. In the experiment, an optical fiber probe with a sorbitol dehydrogenase immobilized membrane was placed in a cuvette filled with a phosphate buffer containing the oxidized form of nicotinamide adenine dinucleotide (NAD(+)). The changes in NADH fluorescence intensity were measured after adding a standard sorbitol solution. According to the experimental assessment, the calibration range of the sorbitol biosensor systems using a spectrometer and a PMT was 5.0-1000 μmol L(-1) and 1.0-1000 μmol L(-1), respectively. The sorbitol biosensor system using the sorbitol dehydrogenase from microorganisms of the genus Flavimonas has high selectivity and sensitivity compared with that from sheep liver. The sorbitol biosensor allows for point-of-care testing applications or daily health care tests for diabetes patients.

  6. Sorbitol Can Fuel Mouse Sperm Motility and Protein Tyrosine Phosphorylation via Sorbitol Dehydrogenase1

    OpenAIRE

    Cao, Wenlei; Aghajanian, Haig K.; Haig-Ladewig, Lisa A.; Gerton, George L.

    2009-01-01

    Energy sources that can be metabolized to yield ATP are essential for normal sperm functions such as motility. Two major monosaccharides, sorbitol and fructose, are present in semen. Furthermore, sorbitol dehydrogenase (SORD) can convert sorbitol to fructose, which can then be metabolized via the glycolytic pathway in sperm to make ATP. Here we characterize Sord mRNA and SORD expression during mouse spermatogenesis and examine the ability of sorbitol to support epididymal sperm motility and t...

  7. Radioluminescence of aromatic molecule solutions in atactic and isotactic polystyrene

    International Nuclear Information System (INIS)

    Lisovskaya, I.A.; Alfimov, M.V.; Milinchuk, V.K.; Skvortsov, V.G.

    1975-01-01

    The generation of excited states of naphthalene-d 8 and carbazole molecules in polystyrene (PS) under X-ray illumination was investigated using luminescence method. A comparison of the concentration dependences of radioluminescence of the aromatic additives to solid PS and to toluene as well as the pattern of concentration versus photoluminescence of naphthalene-d 8 in PS demonstrates that unlike toluene there is no singlet-triplet conversion in PS owing to the formation of excimers. It is shown that the excited ststes of the aromatic additives in PS are populated under radiolysis via an energy transfer from singlet to triplet molecules of the matrix. Under the radiolysis the excited states of PS molecules may generate upon charge recombination. A comparison of radio luminescence spectra of the corresponding aromatic additives in two isomeric PS structures (atacting and isotactic) shows different processes with charge participation. The difference detected in the radioluminescence spectra of aromatic additives in the atactic and isotactic PS explained by the greater number of defects in atactic PS competing with the polymer molecule ion for charge capture

  8. Photonics of dyes molecules in reverse micellar solution

    International Nuclear Information System (INIS)

    Ibragimova, M.R.; Laurinas, V.Ch.

    2001-01-01

    Spectral luminescent characteristics of the dye acridine orange and eosin has been studied in reverse micellar solutions of sodium bis(2-ethyl-hexyl)sulfosuccinate. It was shown that the increase of the nucleus volume of reverse micelles. (author)

  9. Magnetic study of iron sorbitol

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, F.J. E-mail: osoro@posta.unizar.es; Larrea, A.; Abadia, A.R.; Romero, M.S

    2002-09-01

    A magnetic study of iron sorbitol, an iron-containing drug to treat the iron deficiency anemia is presented. Transmission electron microscopy reveals that the system contains nanometric particles with an average diameter of 3 nm whose composition is close to two-line ferrihydrite. The characterisation by magnetisation and AC susceptibility measurements indicates superparamagnetic behaviour with progressive magnetic blocking starting at 8 K. The quantitative analysis of the magnetic results indicates that the system consists of an assembly of very small magnetic moments, presumably originated by spin uncompensation of the antiferromagnetic nanoparticles, with Arrhenius type magnetic dynamics.

  10. Combinatorial expressions of the solutions to initial value problems of the discrete and ultradiscrete Toda molecules

    International Nuclear Information System (INIS)

    Kamioka, Shuhei; Takagaki, Tomoaki

    2013-01-01

    Combinatorial expressions are presented of the solutions to initial value problems of the discrete and ultradiscrete Toda molecules. For the discrete Toda molecule, a subtraction-free expression of the solution is derived in terms of non-intersecting paths, for which two results in combinatorics, Flajolet’s interpretation of continued fractions and Gessel–Viennot’s lemma on determinants, are applied. By ultradiscretizing the subtraction-free expression, the solution to the ultradiscrete Toda molecule is obtained. It is finally shown that the initial value problem of the ultradiscrete Toda molecule is exactly solved in terms of shortest paths on a specific graph. The behavior of the solution is also investigated in comparison with the box–ball system. (paper)

  11. Molecular dynamics studies of the conformation of sorbitol

    Science.gov (United States)

    Lerbret, A.; Mason, P.E.; Venable, R.M.; Cesàro, A.; Saboungi, M.-L.; Pastor, R.W.; Brady, J.W.

    2009-01-01

    Molecular dynamics simulations of a 3 m aqueous solution of D-sorbitol (also called D-glucitol) have been performed at 300 K, as well as at two elevated temperatures to promote conformational transitions. In principle, sorbitol is more flexible than glucose since it does not contain a constraining ring. However, a conformational analysis revealed that the sorbitol chain remains extended in solution, in contrast to the bent conformation found experimentally in the crystalline form. While there are 243 staggered conformations of the backbone possible for this open-chain polyol, only a very limited number were found to be stable in the simulations. Although many conformers were briefly sampled, only eight were significantly populated in the simulation. The carbon backbones of all but two of these eight conformers were completely extended, unlike the bent crystal conformation. These extended conformers were stabilized by a quite persistent intramolecular hydrogen bond between the hydroxyl groups of carbon C-2 and C-4. The conformational populations were found to be in good agreement with the limited available NMR data except for the C-2–C-3 torsion (spanned by the O-2–O-4 hydrogen bond), where the NMR data supports a more bent structure. PMID:19744646

  12. 21 CFR 862.1670 - Sorbitol dehydrogenase test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sorbitol dehydrogenase test system. 862.1670... Systems § 862.1670 Sorbitol dehydrogenase test system. (a) Identification. A sorbitol dehydrogenase test system is a device intended to measure the activity of the enzyme sorbitol dehydrogenase in serum...

  13. Adaptive resolution simulation of an atomistic DNA molecule in MARTINI salt solution

    NARCIS (Netherlands)

    Zavadlav, J.; Podgornik, R.; Melo, M.n.; Marrink, S.j.; Praprotnik, M.

    2016-01-01

    We present a dual-resolution model of a deoxyribonucleic acid (DNA) molecule in a bathing solution, where we concurrently couple atomistic bundled water and ions with the coarse-grained MAR- TINI model of the solvent. We use our fine-grained salt solution model as a solvent in the inner shell

  14. Sorbitol Can Fuel Mouse Sperm Motility and Protein Tyrosine Phosphorylation via Sorbitol Dehydrogenase1

    Science.gov (United States)

    Cao, Wenlei; Aghajanian, Haig K.; Haig-Ladewig, Lisa A.; Gerton, George L.

    2008-01-01

    Energy sources that can be metabolized to yield ATP are essential for normal sperm functions such as motility. Two major monosaccharides, sorbitol and fructose, are present in semen. Furthermore, sorbitol dehydrogenase (SORD) can convert sorbitol to fructose, which can then be metabolized via the glycolytic pathway in sperm to make ATP. Here we characterize Sord mRNA and SORD expression during mouse spermatogenesis and examine the ability of sorbitol to support epididymal sperm motility and tyrosine phosphorylation. Sord mRNA levels increased during the course of spermatogenic differentiation. SORD protein, however, was first detected at the condensing spermatid stage. By indirect immunofluorescence, SORD was present along the length of the flagella of caudal epididymal sperm. Furthermore, immunoelectron microscopy showed that SORD was associated with mitochondria and the plasma membranes of sperm. Sperm incubated with sorbitol maintained motility, indicating that sorbitol was utilized as an energy source. Sorbitol, as well as glucose and fructose, were not essential to induce hyperactive motility. Protein tyrosine phosphorylation increased in a similar manner when sorbitol was substituted for glucose in the incubation medium used for sperm capacitation. These results indicate that sorbitol can serve as an alternative energy source for sperm motility and protein tyrosine phosphorylation. PMID:18799757

  15. 75 FR 16839 - Sorbitol From France

    Science.gov (United States)

    2010-04-02

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-44 (Third Review)] Sorbitol From France AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject review. DATES: Effective Date: Date of Commission approval. FOR FURTHER INFORMATION CONTACT: Dana Lofgren (202...

  16. Effect of nonabsorbed amounts of a fructose-sorbitol mixture on small intestinal transit in healthy volunteers

    DEFF Research Database (Denmark)

    Madsen, Jan L; Linnet, Jan; Rumessen, Jüri J

    2006-01-01

    Although malabsorption of small amounts of fructose-sorbitol mixtures occurs frequently in healthy humans, insights into their effects on gastrointestinal motility are poor. The present study addresses the hypothesis that malabsorption of a fructose-sorbitol challenge changes the small intestinal...... transit rate. Eleven healthy volunteers participated in a double-blind crossover investigation. In random order, the subjects ingested 30 g glucose or a mixture of 25 g fructose and 5 g sorbitol as 10% solutions. As a radiolabeled marker, (99m)Tc-diethylenetriaminepentaacetic acid was added to each test...... solution. Breath hydrogen and methane concentrations and gastrointestinal progress of the radiolabeled marker were followed for the next 6-hr period. Malabsorption of small amounts of the fructose-sorbitol mixture was evident in all subjects. The area under the gastric radioactivity-time curve after...

  17. Effect of nonabsorbed amounts of a fructose-sorbitol mixture on small intestinal transit in healthy volunteers

    DEFF Research Database (Denmark)

    Madsen, Jan L; Linnet, Jan; Rumessen, Jüri J

    2006-01-01

    transit rate. Eleven healthy volunteers participated in a double-blind crossover investigation. In random order, the subjects ingested 30 g glucose or a mixture of 25 g fructose and 5 g sorbitol as 10% solutions. As a radiolabeled marker, (99m)Tc-diethylenetriaminepentaacetic acid was added to each test......Although malabsorption of small amounts of fructose-sorbitol mixtures occurs frequently in healthy humans, insights into their effects on gastrointestinal motility are poor. The present study addresses the hypothesis that malabsorption of a fructose-sorbitol challenge changes the small intestinal...... solution. Breath hydrogen and methane concentrations and gastrointestinal progress of the radiolabeled marker were followed for the next 6-hr period. Malabsorption of small amounts of the fructose-sorbitol mixture was evident in all subjects. The area under the gastric radioactivity-time curve after...

  18. Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review

    International Nuclear Information System (INIS)

    Sharma, G. D.

    2011-01-01

    Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm 2 has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

  19. Humectancies of d-tagatose and d-sorbitol.

    Science.gov (United States)

    Lu, Y

    2001-06-01

    Most toothpastes contain either d-sorbitol or glycerin, or both, as humectants. Both compounds are about half as sweet as sucrose. This level of sweetness is not as intense as desired by most people when brushing teeth. Therefore, many brands of toothpaste add saccharin, a high-intensity sweetener, to increase product sweetness to acceptable levels. While this combination provides the required bulk, humectancy and sweetness, the last characteristic suffers from the widely perceived metallic, or bitter, aftertaste of saccharin. d-tagatose, a full-bulk, low-calorie, sucrose-like sweetener with about twice the sweetness of d-sorbitol, and which does not promote tooth decay, holds promise as a sole sweetener for toothpastes. The only untested aspect of this use of d-tagatose was its humectancy, the characteristic that retains the required level of moisture in toothpaste. The current study was made to investigate this important property, to make a direct comparison of the humectancies of d-tagatose and d-sorbitol as pure substances, and to determine whether the humectancy of d-tagatose is sufficient to counter the crystallizing potentiation of the abrasives used in toothpastes. The humectancies of d-tagatose and d-sorbitol were tested through measuring their water activity (a(w)) vs. water content. By comparing their desorption curves, d-tagatose was seen to have a humectancy equal to that of d-sorbitol when a(w) in the d-tagatose solution was above 0.62. d-Tagatose was then tested in toothpastes containing typical abrasives to determine whether the abrasives would induce crystallization of the sweetener. The addition of 20-25% wt/wt of d-tagatose to the Tom of Maine's toothpastes imparted a satisfactory sweetness. It was found that, within that range of concentration, d-tagatose retained its humectancy, and did not crystallize in the popular brands of commercial toothpastes tested. Thus, d-tagatose could be used as a humectant sweetener in toothpastes, although further

  20. Finding Solutions to Different Problems Simultaneously in a Multi-molecule Simulated Reactor

    Directory of Open Access Journals (Sweden)

    Jaderick P. Pabico

    2014-12-01

    Full Text Available – In recent years, the chemical metaphor has emerged as a computational paradigm based on the observation of different researchers that the chemical systems of living organisms possess inherent computational properties. In this metaphor, artificial molecules are considered as data or solutions, while the interactions among molecules are defined by an algorithm. In recent studies, the chemical metaphor was used as a distributed stochastic algorithm that simulates an abstract reactor to solve the traveling salesperson problem (TSP. Here, the artificial molecules represent Hamiltonian cycles, while the reactor is governed by reactions that can re-order Hamiltonian cycles. In this paper, a multi-molecule reactor (MMR-n that simulates chemical catalysis is introduced. The MMR-n solves in parallel three NP-hard computational problems namely, the optimization of the genetic parameters of a plant growth simulation model, the solution to large instances of symmetric and asymmetric TSP, and the static aircraft landing scheduling problems (ALSP. The MMR-n was shown as a computational metaphor capable of optimizing the cultivar coefficients of CERES-Rice model, and at the same time, able to find solutions to TSP and ALSP. The MMR-n as a computational paradigm has a better computational wall clock time compared to when these three problems are solved individually by a single-molecule reactor (MMR-1.

  1. Small molecule solution-processed bulk heterojunction solar cells with inverted structure using porphyrin donor

    Science.gov (United States)

    Yamamoto, Takaki; Hatano, Junichi; Nakagawa, Takafumi; Yamaguchi, Shigeru; Matsuo, Yutaka

    2013-01-01

    Utilizing tetraethynyl porphyrin derivative (TE-Por) as a small molecule donor material, we fabricated a small molecule solution-processed bulk heterojunction (BHJ) solar cell with inverted structure, which exhibited 1.6% power conversion efficiency (JSC (short-circuit current) = 4.6 mA/cm2, VOC (open-circuit voltage) = 0.90 V, and FF (fill factor) = 0.39) in the device configuration indium tin oxide/TiOx (titanium sub-oxide)/[6,6]-phenyl-C61-butyric acid methyl ester:TE-Por (5:1)/MoOx (molybdenum sub-oxide)/Au under AM1.5 G illumination at 100 mW/cm2. Without encapsulation, the small molecule solution-processed inverted BHJ solar cell also showed remarkable durability to air, where it kept over 73% of its initial power conversion efficiency after storage for 28 days under ambient atmosphere in the dark.

  2. Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

    Directory of Open Access Journals (Sweden)

    Carla Eliana Todero Ritter

    2013-01-01

    Full Text Available The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v soy bran; 0.1% (w/v wheat bran; and a solution of salts. The highest filter paper activity (FPA ( IU·mL−1 was obtained on the seventh day in the medium containing 0.5% (w/v sorbitol and 0.5% (w/v cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day ( IU·mL−1 in the medium containing 0.75% (w/v sorbitol and 0.75% (w/v cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v sorbitol and 0.25% (w/v cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

  3. Differentiation between Trichophyton mentagrophytes and T. rubrum by sorbitol assimilation.

    OpenAIRE

    Rezusta, A; Rubio, M C; Alejandre, M C

    1991-01-01

    Trichophyton rubrum was easily differentiated from T. mentagrophytes by its ability to assimilate sorbitol with an API 20C AUX strip. One hundred percent of 36 T. rubrum strains and none of 147 T. mentagrophytes strains assimilated sorbitol.

  4. Structure-property relation in HPMC polymer films plasticized with Sorbitol

    Science.gov (United States)

    Prakash, Y.; Somashekarappa, H.; Mahadevaiah, Somashekar, R.

    2013-06-01

    A correlation study on physical and mechanical properties of Hydroxy propyl-methylcellulose (HPMC) polymer films plasticized with different weight ratio of Sorbitol, prepared using solution casting method, was carried out using wide angle X-ray technique and universal testing machine. It is found that the crystallanity decreases as the concentration of Sorbitol increases up to a certain concentration and there afterwards increases. Measured Physical Properties like tensile strength decreases and elongation (%) increases indicating increase in the flexibility of the films. These observations confirm the correlation between microstructal parameters and mechanical properties of films. These films are suitable for packaging food products.

  5. Solution-processed white organic light-emitting devices based on small-molecule materials

    International Nuclear Information System (INIS)

    Wang Dongdong; Wu Zhaoxin; Zhang Xinwen; Wang Dawei; Hou Xun

    2010-01-01

    We investigated solution-processed films of 4,4'-bis(2,2-diphenylvinyl)-1,1'-bibenyl (DPVBi) and its blends with N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD) by atomic force microscopy (AFM). The AFM result shows that the solution-processed films are pin-free and their morphology is smooth enough to be used in OLEDs. We have developed a solution-processed white organic light-emitting device (WOLEDs) based on small-molecules, in which the light-emitting layer (EML) was formed by spin-coating the solution of small-molecules on top of the solution-processed hole-transporting layer. This WOLEDs, in which the EML consists of co-host (DPVBi and TPD), the blue dopant (4,4'-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl) and the yellow dye (5,6,11,12-tetraphenylnaphtacene), has a current efficiency of 6.0 cd/A at a practical luminance of 1000 cd/m 2 , a maximum luminance of 22500 cd/m 2 , and its color coordinates are quite stable. Our research shows a possible approach to achieve efficient and low-cost small-molecule-based WOLEDs, which avoids the complexities of the co-evaporation process of multiple dopants and host materials in vacuum depositions.

  6. Considerable improvement in the stability of solution processed small molecule OLED by annealing

    Energy Technology Data Exchange (ETDEWEB)

    Mao Guilin [Key Laboratory of Photonics Technology for Information, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic and Information Engineering, Xi' an Jiaotong University, Xi' an, 710049 (China); Wu Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn [Key Laboratory of Photonics Technology for Information, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic and Information Engineering, Xi' an Jiaotong University, Xi' an, 710049 (China); He Qiang [Key Laboratory of Photonics Technology for Information, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic and Information Engineering, Xi' an Jiaotong University, Xi' an, 710049 (China); Department of UAV, Wuhan Ordnance Noncommissioned Officers Academy, Wuhan, 430075 (China); Jiao Bo; Xu Guojin; Hou Xun [Key Laboratory of Photonics Technology for Information, Key Laboratory for Physical Electronics and Devices of the Ministry of Education, School of Electronic and Information Engineering, Xi' an Jiaotong University, Xi' an, 710049 (China); Chen Zhijian; Gong Qihuang [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing, 100871 (China)

    2011-06-15

    We investigated the annealing effect on solution processed small organic molecule organic films, which were annealed with various conditions. It was found that the densities of the spin-coated (SC) films increased and the surface roughness decreased as the annealing temperature rose. We fabricated corresponding organic light emitting diodes (OLEDs) by spin coating on the same annealing conditions. The solution processed OLEDs show the considerable efficiency and stability, which were prior or equivalent to the vacuum-deposited (VD) counterparts. Our research shows that annealing process plays a key role in prolonging the lifetime of solution processed small molecule OLEDs, and the mechanism for the improvement of the device performance upon annealing was also discussed.

  7. The effects of urea, guanidinium chloride and sorbitol on porphyrin ...

    Indian Academy of Sciences (India)

    This paper compares the inhibition effect of porphyrin aggregation in the presence of urea, guanidinium chloride (Gdn) and sorbitol by molecular dynamics simulation. It demonstrates that porphyrin aggregation increases in sorbitol, but decreases towards addition of urea and Gdn. It shows that urea, Gdn and sorbitol can ...

  8. Sorbitol as an efficient reducing agent for laser-induced copper deposition

    Science.gov (United States)

    Kochemirovsky, V. A.; Logunov, L. S.; Safonov, S. V.; Tumkin, I. I.; Tver'yanovich, Yu. S.; Menchikov, L. G.

    2012-10-01

    We have pioneered in revealing the fact that sorbitol may be used as an efficient reducing agent in the process of laser-induced copper deposition from solutions; in this case, it is possible to obtain copper lines much higher quality than by using conventional formalin.

  9. Quantum mechanical computations and spectroscopy: from small rigid molecules in the gas phase to large flexible molecules in solution.

    Science.gov (United States)

    Barone, Vincenzo; Improta, Roberto; Rega, Nadia

    2008-05-01

    Interpretation of structural properties and dynamic behavior of molecules in solution is of fundamental importance to understand their stability, chemical reactivity, and catalytic action. While information can be gained, in principle, by a variety of spectroscopic techniques, the interpretation of the rich indirect information that can be inferred from the analysis of experimental spectra is seldom straightforward because of the subtle interplay of several different effects, whose specific role is not easy to separate and evaluate. In such a complex scenario, theoretical studies can be very helpful at two different levels: (i) supporting and complementing experimental results to determine the structure of the target molecule starting from its spectral properties; (ii) dissecting and evaluating the role of different effects in determining the observed spectroscopic properties. This is the reason why computational spectroscopy is rapidly evolving from a highly specialized research field into a versatile and widespread tool for the assignment of experimental spectra and their interpretation in terms of chemical physical effects. In such a situation, it becomes important that both computationally and experimentally oriented chemists are aware that new methodological advances and integrated computational strategies are available, providing reliable estimates of fundamental spectral parameters not only for relatively small molecules in the gas phase but also for large and flexible molecules in condensed phases. In this Account, we review the most significant methodological contributions from our research group in this field, and by exploiting some recent results of their application to the computation of IR, UV-vis, NMR, and EPR spectral parameters, we discuss the microscopic mechanisms underlying solvent and vibrational effects on the spectral parameters. After reporting some recent achievements for the study of excited states by first principle quantum mechanical

  10. Single molecule dynamics at a mechanically controllable break junction in solution at room temperature.

    Science.gov (United States)

    Konishi, Tatsuya; Kiguchi, Manabu; Takase, Mai; Nagasawa, Fumika; Nabika, Hideki; Ikeda, Katsuyoshi; Uosaki, Kohei; Ueno, Kosei; Misawa, Hiroaki; Murakoshi, Kei

    2013-01-23

    The in situ observation of geometrical and electronic structural dynamics of a single molecule junction is critically important in order to further progress in molecular electronics. Observations of single molecular junctions are difficult, however, because of sensitivity limits. Here, we report surface-enhanced Raman scattering (SERS) of a single 4,4'-bipyridine molecule under conditions of in situ current flow in a nanogap, by using nano-fabricated, mechanically controllable break junction (MCBJ) electrodes. When adsorbed at room temperature on metal nanoelectrodes in solution to form a single molecule junction, statistical analysis showed that nontotally symmetric b(1) and b(2) modes of 4,4'-bipyridine were strongly enhanced relative to observations of the same modes in solid or aqueous solutions. Significant changes in SERS intensity, energy (wavenumber), and selectivity of Raman vibrational bands that are coincident with current fluctuations provide information on distinct states of electronic and geometrical structure of the single molecule junction, even under large thermal fluctuations occurring at room temperature. We observed the dynamics of 4,4'-bipyridine motion between vertical and tilting configurations in the Au nanogap via b(1) and b(2) mode switching. A slight increase in the tilting angle of the molecule was also observed by noting the increase in the energies of Raman modes and the decrease in conductance of the molecular junction.

  11. Line printing solution-processable small molecules with uniform surface profile via ink-jet printer.

    Science.gov (United States)

    Liu, Huimin; Xu, Wei; Tan, Wanyi; Zhu, Xuhui; Wang, Jian; Peng, Junbiao; Cao, Yong

    2016-03-01

    Line printing offers a feasible approach to remove the pixel well structure which is widely used to confine the ink-jet printed solution. In the study, a uniform line is printed by an ink-jet printer. To achieve a uniform surface profile of the printed line, 10vol% low-volatile solvent DMA (3,4-Dimethylanisole) is mixed with high-volatile solvent Pxy (p-xylene) as the solvent. After a solution-processable small molecule is dissolved, the surface tension of DMA solution becomes lower than that of Pxy solution, which creates an inward Marangoni flow during the solvent evaporation. The inward Marangoni flow balances out the outward capillary flow, thereby forming a flat film surface. The line width of the printed line depends on the contact angle of the solution on the hole injection layer. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Real-time monitoring and manipulation of single bio-molecules in free solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hung-Wing [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    The observation and manipulation of single biomolecules allow their dynamic behaviors to be studied to provide insight into molecular genetics, biochip assembly, biosensor design, DNA biophysics. In a PDMS/glass microchannel, a nonuniform electroosmotic flow (EOF) was created. By using a scanning confocal fluorescence microscope and total internal-reflection fluorescence microscope (TIRFM), we demonstrated that negatively charged DNA molecules were focused by the nonuniform EOF into a thin layer at the glass surface. This phenomenon was applied to selectively detect target DNA molecules without requiring the separation of excessive probes and can be applied continuously to achieve high throughput. A variable-angle-TIRFM was constructed for imaging single DNA molecule dynamics at a solid/liquid interface. Implications we have are that the measured intensities cannot be used directly to determine the distances of molecules from the surface and the experimental counting results depict the distance-dependent dynamics of molecules near the surface; Molecules at low ionic strengths experience electrostatic repulsion at distances much further away from the surface than the calculated thickness of the electrical double layer. {delta}-DNA was employed as a nanoprobe for different functionalized surfaces to elucidate adsorption in chromatography. The 12-base unpaired ends of this DNA provide exposed purine and pyrimidine groups for adsorption. Patterns of self-assembled monolayers (SAMs) and patterns of metal oxides are generated. By recording the real-time dynamic motion of DNA molecules at the SAMs/aqueous interface, the various parameters governing the retention of an analyte during chromatographic separation can be studied. Even subtle differences among adsorptive forces can be revealed. Dynamic conformational changes of the prosthetic group, flavin adenine dinucleotide (FAD), in flavoprotein NADH peroxidase, in thioredoxin reductase, and in free solution were monitored

  13. Fluorescent molecule incorporated metal-organic framework for fluoride sensing in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xudong, E-mail: zhaoxd_tykj@163.com; Wang, Yuanyang; Hao, Xiuli; Liu, Wen, E-mail: 13700509372@163.com

    2017-04-30

    Highlights: • Fluorescein sodium was successfully encapsulated in UiO-66 via in-situ synthesis. • FS@UiO-66 is one of the few Zr-MOF-based probes for fluoride so far. • FS@UiO-66 is a highly effective, fast-response and naked-eye sensor for fluoride. - Abstract: In this work, the fluorescent molecule (fluorescein sodium, FS) was successfully incorporated in the zirconium-based MOF (UiO-66) via in-situ synthesis method, which can be confirmed by FTIR spectra and fluorescence microscopic images. Based on this in-situ synthesis strategy, FS molecule can be immobilized tightly in the framework. Furthermore, the resulting FS@UiO-66 demonstrates to be a highly selective, real-time and naked-eye chemical sensor for fluoride in aqueous solution, which is mainly due to the release of FS molecule from FS@UiO-66 into the aqueous solution. Meanwhile, to the best of our knowledge, such Zr-MOF-based fluoride sensor is very rare so far. These results provide a promising approach to rationally design novel MOF-based fluorescent sensor for the target molecules.

  14. Chromatin-associated regulation of sorbitol synthesis in flower buds of peach.

    Science.gov (United States)

    Lloret, Alba; Martínez-Fuentes, Amparo; Agustí, Manuel; Badenes, María Luisa; Ríos, Gabino

    2017-11-01

    PpeS6PDH gene is postulated to mediate sorbitol synthesis in flower buds of peach concomitantly with specific chromatin modifications. Perennial plants have evolved an adaptive mechanism involving protection of meristems within specialized structures named buds in order to survive low temperatures and water deprivation during winter. A seasonal period of dormancy further improves tolerance of buds to environmental stresses through specific mechanisms poorly known at the molecular level. We have shown that peach PpeS6PDH gene is down-regulated in flower buds after dormancy release, concomitantly with changes in the methylation level at specific lysine residues of histone H3 (H3K27 and H3K4) in the chromatin around the translation start site of the gene. PpeS6PDH encodes a NADPH-dependent sorbitol-6-phosphate dehydrogenase, the key enzyme for biosynthesis of sorbitol. Consistently, sorbitol accumulates in dormant buds showing higher PpeS6PDH expression. Moreover, PpeS6PDH gene expression is affected by cold and water deficit stress. Particularly, its expression is up-regulated by low temperature in buds and leaves, whereas desiccation treatment induces PpeS6PDH in buds and represses the gene in leaves. These data reveal the concurrent participation of chromatin modification mechanisms, transcriptional regulation of PpeS6PDH and sorbitol accumulation in flower buds of peach. In addition to its role as a major translocatable photosynthate in Rosaceae species, sorbitol is a widespread compatible solute and cryoprotectant, which suggests its participation in tolerance to environmental stresses in flower buds of peach.

  15. Comparison of 3% sorbitol vs psyllium fibre as oral contrast agents in MR enterography.

    Science.gov (United States)

    Saini, Sidharth; Colak, Errol; Anthwal, Shalini; Vlachou, Paraskevi A; Raikhlin, Antony; Kirpalani, Anish

    2014-10-01

    To compare the degree of small bowel distension achieved by 3% sorbitol, a high osmolarity solution, and a psyllium-based bulk fibre as oral contrast agents (OCAs) in MR enterography (MRE). This retrospective study was approved by our institutional review board. A total of 45 consecutive normal MRE examinations (sorbitol, n = 20; psyllium, n = 25) were reviewed. The patients received either 1.5 l of 3% sorbitol or 2 l of 1.6 g kg(-1) psyllium prior to imaging. Quantitative small bowel distension measurements were taken in five segments: proximal jejunum, distal jejunum, proximal ileum, distal ileum and terminal ileum by two independent radiologists. Distension in these five segments was also qualitatively graded from 0 (very poor) to 4 (excellent) by two additional independent radiologists. Statistical analysis comparing the groups and assessing agreement included intraclass coefficients, Student's t-test and Mann-Whitney U-test. Small bowel distension was not significantly different in any of the five small bowel segments between the use of sorbitol and psyllium as OCAs in both the qualitative (p = 0.338-0.908) and quantitative assessments (p = 0.083-0.856). The mean bowel distension achieved was 20.1 ± 2.2 mm for sorbitol and 19.8 ± 2.5 mm for psyllium (p = 0.722). Visualization of the ileum was good or excellent in 65% of the examinations in both groups. Sorbitol and psyllium are not significantly different at distending the small bowel and both may be used as OCAs for MRE studies. This is the first study to directly compare the degree of distension in MRE between these two common, readily available and inexpensive OCAs.

  16. Toda molecule and Tomimatsu-Sato solution-towards the complete proof of Nakamura's conjecture

    International Nuclear Information System (INIS)

    Fukuyama, Takeshi; Koizumi, Kozo

    2011-01-01

    We discuss the Nakamura's conjecture stating that the Tomimatsu-Sato black hole solution with an integer deformation parameter n is composed of the special solutions of the Toda molecule equation at the nth lattice site. From the previous work, in which the conjecture was partly analytically proved, we go further towards the final full proof by rearranging the rotation parameter. The proof is explicitly performed for the highest and lowest orders. Though the proof for all orders still remains unsolved, the prospect to the full proof becomes transparent and workable by our method. (paper)

  17. Solution of problem of determining spin properties of molecules in unitary formalism of quantum chemistry

    International Nuclear Information System (INIS)

    Klimko, G.T.; Luzanov, A.V.

    1988-01-01

    An analysis has been made of the problem of calculating one- and two-particle spin densities, which are needed in calculations of spin-orbit and spin-spin coupling. The proposed solution is oriented toward the application of computational algorithms using unitary group representations; the solution consists of explicit expressions for the matrix elements of spin density operators in terms of the means of products of spin-free generators. This has eliminated a serious problem encountered previously in determining spin characteristics of molecules within the framework of unitary formalism

  18. Multi-solution processes of small molecule for flexible white organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Yu-Sheng, E-mail: ystsai@nfu.edu.tw [Institute of Electro-optical and Materials Science, National Formosa University, Yunlin 63201, Taiwan, ROC (China); Chittawanij, Apisit; Hong, Lin-Ann; Guo, Siou-Wei [Institute of Electro-optical and Materials Science, National Formosa University, Yunlin 63201, Taiwan, ROC (China); Wang, Ching-Chiun [Department of Solid State Lighting Technology, Mechanical and Systems Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan, ROC (China); Juang, Fuh-Shyang [Institute of Electro-optical and Materials Science, National Formosa University, Yunlin 63201, Taiwan, ROC (China); Lai, Shih-Hsiang [Department of Solid State Lighting Technology, Mechanical and Systems Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan, ROC (China); Lin, Yang-Ching [Institute of Electro-optical and Materials Science, National Formosa University, Yunlin 63201, Taiwan, ROC (China)

    2016-04-01

    Most small molecule organic light emitting diode (SM-OLED) device structures are made in one layer using solution-based processing because the solution is usually a high dissolvent material that easily attacks the layer below it. We demonstrate a simple and reliable stamping technique for fabricating multi-solution process flexible white SM-OLEDs. The structure is anode/spin-hole injection layer/spin-emitting layer/stamping-electron transport layer/cathode. Poly(di-methyl silane) (PDMS) stamp is used for transferring electron transport layer. An intermediate ultraviolet-ozone surface treatment is introduced to temporarily modify the PDMS stamp surface. Then, the solution-based electron transport layer film can therefore be uniformly formed on top of the PDMS surface. After that the electron transport layer film on the PDMS stamp is transfer-printed onto the emitting layer with suitable heating and pressing. A solution-based processing is successfully established to efficiently fabricate flexible white SM-OLEDs. The SM-OLEDs were obtained at the current density of 20 mA/cm{sup 2}, luminance of 1062 cd/m{sup 2}, current efficiency of 5.57 cd/A, and Commission internationale de l'éclairage coordinate of (0.32, 0.35). - Highlights: • All solution-processed small molecule materials (emitting layer, electron transport layer). • Poly(di-methylsilane) (PDMS) stamp is subsequently used for stamping transfer. • The flexible white SM-OLEDs are based on solution-processes with a low-cost method.

  19. Multi-solution processes of small molecule for flexible white organic light-emitting diodes

    International Nuclear Information System (INIS)

    Tsai, Yu-Sheng; Chittawanij, Apisit; Hong, Lin-Ann; Guo, Siou-Wei; Wang, Ching-Chiun; Juang, Fuh-Shyang; Lai, Shih-Hsiang; Lin, Yang-Ching

    2016-01-01

    Most small molecule organic light emitting diode (SM-OLED) device structures are made in one layer using solution-based processing because the solution is usually a high dissolvent material that easily attacks the layer below it. We demonstrate a simple and reliable stamping technique for fabricating multi-solution process flexible white SM-OLEDs. The structure is anode/spin-hole injection layer/spin-emitting layer/stamping-electron transport layer/cathode. Poly(di-methyl silane) (PDMS) stamp is used for transferring electron transport layer. An intermediate ultraviolet-ozone surface treatment is introduced to temporarily modify the PDMS stamp surface. Then, the solution-based electron transport layer film can therefore be uniformly formed on top of the PDMS surface. After that the electron transport layer film on the PDMS stamp is transfer-printed onto the emitting layer with suitable heating and pressing. A solution-based processing is successfully established to efficiently fabricate flexible white SM-OLEDs. The SM-OLEDs were obtained at the current density of 20 mA/cm"2, luminance of 1062 cd/m"2, current efficiency of 5.57 cd/A, and Commission internationale de l'éclairage coordinate of (0.32, 0.35). - Highlights: • All solution-processed small molecule materials (emitting layer, electron transport layer). • Poly(di-methylsilane) (PDMS) stamp is subsequently used for stamping transfer. • The flexible white SM-OLEDs are based on solution-processes with a low-cost method.

  20. 3,3′-Bicarbazole-Based Host Molecules for Solution-Processed Phosphorescent OLEDs

    Directory of Open Access Journals (Sweden)

    Jungwoon Kim

    2018-04-01

    Full Text Available Solution-processed organic light-emitting diodes (OLEDs are attractive due to their low-cost, large area displays, and lighting features. Small molecules as well as polymers can be used as host materials within the solution-processed emitting layer. Herein, we report two 3,3′-bicarbazole-based host small molecules, which possess a structural isomer relationship. 9,9′-Di-4-n-butylphenyl-9H,9′H-3,3′-bicarbazole (BCz-nBuPh and 9,9′-di-4-t-butylphenyl-9H,9′H-3,3′-bicarbazole (BCz-tBuPh exhibited similar optical properties within solutions but different photoluminescence within films. A solution-processed green phosphorescent OLED with the BCz-tBuPh host exhibited a high maximum current efficiency and power efficiency of 43.1 cd/A and 40.0 lm/W, respectively, compared to the device with the BCz-nBuPh host.

  1. The metabolic fate of exogenous sorbitol in the rat

    International Nuclear Information System (INIS)

    Ertel, N.H.; Akgun, S.; Kemp, F.W.; Mittler, J.C.

    1983-01-01

    Dietary sorbitol is rapidly converted to fructose and other carbohydrates in the liver, but its metabolic fate has not been studied rigorously. Twenty-four rats were given 20.4 muCi [ 14 C]sorbitol with 100 mg of sorbitol, and groups of six were killed at 1, 3, 6, and 24 hours after sorbitol administration. Rats were also fed 6.9 muCi [ 14 C]sorbitol for 7 or 14 days. Serum, liver, and lens were analyzed for 14 C-labeled sorbitol, fructose, and glucose by using high-performance liquid chromatography. Negligible radioactivity (1.1%) was found in the gastrointestinal content at 24 hours indicating virtually complete absorption. Most of the radioactivity was recovered in the glucose fraction in serum, liver and lens. Glucose and fructose concentrations showed some decline by day 14 compared with day 7 in serum and liver. However, in the lens, sorbitol showed a peak value at the end of the 14th day (37.5 +/- 9.9 micrograms/pair). These findings suggest that: 1) after oral administration, sorbitol is completely absorbed, and 2) that there is a finite accumulation of sorbitol and fructose in the lens in 14 days. Although the radioactive label indicated the exogenous origin of these carbohydrates, it is not certain whether the sorbitol is converted to glucose before entering and accumulating in the lens

  2. Detection of electrically neutral and nonpolar molecules in ionic solutions using silicon nanowires

    Science.gov (United States)

    Wu, Ying-Pin; Chu, Chia-Jung; Tsai, Li-Chu; Su, Ya-Wen; Chen, Pei-Hua; Moodley, Mathew K.; Huang, Ding; Chen, Yit-Tsong; Yang, Ying-Jay; Chen, Chii-Dong

    2017-04-01

    We report on a technique that can extend the use of nanowire sensors to the detection of interactions involving nonpolar and neutral molecules in an ionic solution environment. This technique makes use of the fact that molecular interactions result in a change in the permittivity of the molecules involved. For the interactions taking place at the surface of nanowires, this permittivity change can be determined from the analysis of the measured complex impedance of the nanowire. To demonstrate this technique, histidine was detected using different charge polarities controlled by the pH value of the solution. This included the detection of electrically neutral histidine at a sensitivity of 1 pM. Furthermore, it is shown that nonpolar molecules, such as hexane, can also be detected. The technique is applicable to the use of nanowires with and without a surface-insulating oxide. We show that information about the changes in amplitude and the phase of the complex impedance reveals the fundamental characteristics of the molecular interactions, including the molecular field and the permittivity.

  3. Fractionation of hydrogen and oxygen isotopes between hydrated and free water molecules in aqueous urea solution

    International Nuclear Information System (INIS)

    Kakiuchi, M.; Matsuo, S.

    1985-01-01

    Ratios of D/H and 18 O/ 16 O in the vapor phase in equilibrium with aqueous urea solution with different urea molalities were measured at 15 and 25 0 C. Under the assumption that urea solutions consist of two species, i.e., the urea-water cluster and free water, the results are interpreted to give the average hydration number, i.e., the number of water molecules per urea molecule in the urea-water cluster. Good agreement was obtained for the hydration number estimated independently from hydrogen and oxygen isotopic fractions. On the basis of hydrogen isotopic data at 25 0 C, the average hydration number of urea in the cluster is 6.3 +/- 0.8 at 2.1 m and 2.75 +/- 0.08 at saturation (20.15 m). The corresponding average hydration numbers based on oxygen isotopic data were calculated to be 6.7 +/- 2.4 at 2.1 m and 2.75 +/- 0.25 at urea saturation. HD 16 O is enriched in the urea-water cluster and H 2 18 O is enriched in free water. Isotopic partitioning between the cluster and free water is markedly different from those between hydration spheres and free water in aqueous electrolyte solutions. 29 references, 6 figures, 5 tables

  4. Single molecule diffusion and the solution of the spherically symmetric residence time equation.

    Science.gov (United States)

    Agmon, Noam

    2011-06-16

    The residence time of a single dye molecule diffusing within a laser spot is propotional to the total number of photons emitted by it. With this application in mind, we solve the spherically symmetric "residence time equation" (RTE) to obtain the solution for the Laplace transform of the mean residence time (MRT) within a d-dimensional ball, as a function of the initial location of the particle and the observation time. The solutions for initial conditions of potential experimental interest, starting in the center, on the surface or uniformly within the ball, are explicitly presented. Special cases for dimensions 1, 2, and 3 are obtained, which can be Laplace inverted analytically for d = 1 and 3. In addition, the analytic short- and long-time asymptotic behaviors of the MRT are derived and compared with the exact solutions for d = 1, 2, and 3. As a demonstration of the simplification afforded by the RTE, the Appendix obtains the residence time distribution by solving the Feynman-Kac equation, from which the MRT is obtained by differentiation. Single-molecule diffusion experiments could be devised to test the results for the MRT presented in this work. © 2011 American Chemical Society

  5. Differential response of nucleus pulposus intervertebral disc cells to high salt, sorbitol, and urea.

    Science.gov (United States)

    Mavrogonatou, Eleni; Kletsas, Dimitris

    2012-03-01

    Nucleus pulposus intervertebral disc cells are routinely confronted with high osmolality in their microenvironment and respond to this stress in vitro by regulating cell cycle progression and by activating a DNA repair machinery in order to counteract its genotoxic effect. In the present study, we attempted to identify the origin of this osmo-regulatory response, by using an ionic NaCl/KCl solution, the compatible osmolyte sorbitol, and the readily permeant urea. High salt and sorbitol were found to activate similar molecular pathways, including the p38 MAPK and the p53-p21(WAF1)-pRb axis, that were not stimulated by high urea. On the other hand, only high urea led to the phosphorylation of ERKs and JNKs. Furthermore, salt- and sorbitol-treated cells were able to phosphorylate histone H2A.X on Ser139, in contrast to cells exposed to urea, indicating a common mechanism for DNA repair, which was achieved by a p53-dependent activation of the G1 checkpoint by both solutes. DNA repair, as directly measured by a host cell reactivation assay, occurred under conditions of hyperosmolar salt and sorbitol, although to a lesser extent in sorbitol-treated cells than in cells exposed to high salinity. Taken as a whole, our findings suggest that the hyperosmolality-provoked DNA damage and the responses of nucleus pulposus cells induced by this genotoxic stress most probably originate from cell volume alterations mediated by hypertonicity and not from increased intracellular ionic concentration. Copyright © 2011 Wiley Periodicals, Inc.

  6. Production of liquid alkanes by controlling reactivity of sorbitol hydrogenation with a Ni/HZSM-5 catalyst in water

    International Nuclear Information System (INIS)

    Zhang, Qing; Wang, Tiejun; Xu, Ying; Zhang, Qi; Ma, Longlong

    2014-01-01

    Graphical abstract: MCM-41-modified Ni/HZSM-5 catalyst was developed by impregnation method with high catalytic performance for sorbitol hydrogenation in water. Appropriate amount of MCM-41 addition can distinctly promote the improvement in the surface structure and modulation of acidic sites of the catalyst. The scission of C–O bond in the sorbitol molecule into liquid alkanes was easily carried out on the catalyst containing more Lewis acidic sites. - Highlights: • Ni/HZSM-5 promoted with MCM-41 is active for sorbitol hydrogenation to liquid alkanes. • Lewis acidic sites of Ni/HZSM-5 can be modulated by pure silica MCM-41. • MCM-41 added can distinctly decrease carbon deposition on the catalyst surface. - Abstract: Liquid fuels derived from renewable biomass are of great importance on the potential substitution for diminishing fossil fuels. The conversion of sorbitol (a product of biomass-derived glucose hydrogenation) into liquid alkanes such as pentane and hexane over the Ni/HZSM-5 catalysts with or without MCM-41 addition was investigated in the presence of hydrogen in water medium. The production distribution of sorbitol hydrogenation can be controlled by adjusting the acidity of the catalyst. The scission of C–C bond in the sorbitol molecule into light C 1 –C 4 alkanes was mainly carried out over Ni/HZSM-5 containing strong Brønsted acid sites, while C–O bond scission into heavier alkanes was dominated over the catalysts added by MCM-41 containing weak Lewis acid sites. The sorbitol conversion and total liquid alkanes selectivity were found to be 67.1% and 98.7% over 2%Ni/HZSM-5 modified by 40 wt% of MCM-41, whereas the corresponding value was 40% and 35.6% over 2%Ni/HZSM-5 in the absence of MCM-41. The effect of MCM-41 on the structure, acidity, and reducibility of Ni/HZSM-5 was investigated by using XRD, Py-IR, IR, and H 2 -TPR. Meanwhile, the resistance of carbon deposition over the catalyst modified by MCM-41 was studied by using TG

  7. Lipase-Catalyzed Production of 6-O-cinnamoyl-sorbitol from D-sorbitol and Cinnamic Acid Esters.

    Science.gov (United States)

    Kim, Jung-Ho; Bhatia, Shashi Kant; Yoo, Dongwon; Seo, Hyung Min; Yi, Da-Hye; Kim, Hyun Joong; Lee, Ju Hee; Choi, Kwon-Young; Kim, Kwang Jin; Lee, Yoo Kyung; Yang, Yung-Hun

    2015-05-01

    To overcome the poor properties of solubility and stability of cinnamic acid, cinnamate derivatives with sugar alcohols were produced using the immobilized Candida antarctica lipase with vinyl cinnamate and D-sorbitol as substrate at 45 °C. Immobilized C. antarctica lipase was found to synthesize 6-O-cinnamoyl-sorbitol and confirmed by HPLC and (1)H-NMR and had a preference for vinyl cinnamate over other esters such as allyl-, ethyl-, and isobutyl cinnamate as co-substrate with D-sorbitol. Contrary to D-sorbitol, vinyl cinnamate, and cinnamic acid, the final product 6-O-cinnamoyl-sorbitol was found to have radical scavenging activity. This would be the first report on the biosynthesis of 6-O-cinnamoyl-sorbitol with immobilized enzyme from C. antarctica.

  8. Ambipolar Small-Molecule:Polymer Blend Semiconductors for Solution-Processable Organic Field-Effect Transistors.

    Science.gov (United States)

    Kang, Minji; Hwang, Hansu; Park, Won-Tae; Khim, Dongyoon; Yeo, Jun-Seok; Kim, Yunseul; Kim, Yeon-Ju; Noh, Yong-Young; Kim, Dong-Yu

    2017-01-25

    We report on the fabrication of an organic thin-film semiconductor formed using a blend solution of soluble ambipolar small molecules and an insulating polymer binder that exhibits vertical phase separation and uniform film formation. The semiconductor thin films are produced in a single step from a mixture containing a small molecular semiconductor, namely, quinoidal biselenophene (QBS), and a binder polymer, namely, poly(2-vinylnaphthalene) (PVN). Organic field-effect transistors (OFETs) based on QBS/PVN blend semiconductor are then assembled using top-gate/bottom-contact device configuration, which achieve almost four times higher mobility than the neat QBS semiconductor. Depth profile via secondary ion mass spectrometry and atomic force microscopy images indicate that the QBS domains in the films made from the blend are evenly distributed with a smooth morphology at the bottom of the PVN layer. Bias stress test and variable-temperature measurements on QBS-based OFETs reveal that the QBS/PVN blend semiconductor remarkably reduces the number of trap sites at the gate dielectric/semiconductor interface and the activation energy in the transistor channel. This work provides a one-step solution processing technique, which makes use of soluble ambipolar small molecules to form a thin-film semiconductor for application in high-performance OFETs.

  9. Sorbitol dehydrogenase is a cytosolic protein required for sorbitol metabolism in Arabidopsis thaliana.

    Science.gov (United States)

    Aguayo, María Francisca; Ampuero, Diego; Mandujano, Patricio; Parada, Roberto; Muñoz, Rodrigo; Gallart, Marta; Altabella, Teresa; Cabrera, Ricardo; Stange, Claudia; Handford, Michael

    2013-05-01

    Sorbitol is converted to fructose in Rosaceae species by SORBITOL DEHYDROGENASE (SDH, EC 1.1.1.14), especially in sink organs. SDH has also been found in non-Rosaceae species and here we show that the protein encoded by At5g51970 in Arabidopsis thaliana (L.) Heynh. possesses the molecular characteristics of an SDH. Using a green fluorescent protein-tagged version and anti-SDH antisera, we determined that SDH is cytosolically localized, consistent with bioinformatic predictions. We also show that SDH is widely expressed, and that SDH protein accumulates in both source and sink organs. In the presence of NAD+, recombinant SDH exhibited greatest oxidative activity with sorbitol, ribitol and xylitol as substrates; other sugar alcohols were oxidized to a lesser extent. Under standard growth conditions, three independent sdh- mutants developed as wild-type. Nevertheless, all three exhibited reduced dry weight and primary root length compared to wild-type when grown in the presence of sorbitol. Additionally, under short-day conditions, the mutants were more resistant to dehydration stress, as shown by a reduced loss of leaf water content when watering was withheld, and a greater survival rate on re-watering. This evidence suggests that limitations in the metabolism of sugar alcohols alter the growth of Arabidopsis and its response to drought. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. Temperature Dependence of Charge Localization in High-Mobility, Solution-Crystallized Small Molecule Semiconductors Studied by Charge Modulation Spectroscopy

    DEFF Research Database (Denmark)

    Meneau, Aurélie Y. B.; Olivier, Yoann; Backlund, Tomas

    2016-01-01

    In solution-processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined fi eld-effect tran......In solution-processable small molecule semiconductors, the extent of charge carrier wavefunction localization induced by dynamic disorder can be probed spectroscopically as a function of temperature using charge modulation spectroscopy (CMS). Here, it is shown based on combined fi eld......-effect transistor and CMS measurements as a function of temperature that in certain molecular semiconductors, such as solution-processible pentacene, charge carriers become trapped at low temperatures in environments in which the charges become highly localized on individual molecules, while in some other molecules...

  11. Preparation and Characterization of HPMC/PVP Blend Films Plasticized with Sorbitol

    OpenAIRE

    Somashekarappa, H.; Prakash, Y.; Hemalatha, K.; Demappa, T.; Somashekar, R.

    2013-01-01

    The aim of this present work is to investigate the effect of plasticizers like Sorbitol on microstructural and mechanical properties of hydroxypropyl methylcellulose (HPMC) and Polyvinylpyrrolidone (PVP) blend films. The pure blend and plasticized blend films were prepared by solution casting method and investigated using wide angle X-ray scattering (WAXS) method. WAXS analysis confirms that the plasticizers can enter into macromolecular blend structure and destroy the crystallinity of the f...

  12. Radical Cationic Pathway for the Decay of Ionized Glyme Molecules in Liquid Solution.

    Science.gov (United States)

    Taletskiy, Konstantin S; Borovkov, Vsevolod I; Schegoleva, Lyudmila N; Beregovaya, Irina V; Taratayko, Andrey I; Molin, Yuriy N

    2015-11-12

    Chemical stability of primary radical cations (RCs) generated in irradiated matter determines substantially the radiation resistance of organic materials. Transformations of the RCs of the glyme molecules, R(-O-CH2-CH2-)nO-R (R = CH3, n = 1-4) has been studied on the nanosecond time scale by measuring the magnetic field effects in the recombination fluorescence from irradiated liquid solutions of the glymes. In all cases, the RCs observed were different from that expected for the primary ones and revealed very similar hyperfine couplings independent of the poly(ethylene oxide) chain length and of the substitution of terminal methyl groups by C2H5 or CH2CH2Cl, as has been shown with diglyme as an example. Quantum chemical analysis of possible chemical transformations for the monoglyme RC as a model system allowed us to discover the reaction pathway yielding the methyl vinyl ether RC. The pathway involves intramolecular proton transfer followed by C-O bond cleavage. Only one (-O-CH2-CH2-O-) fragment is involved in this transformation, which is nearly barrierless due to the catalytic effect of adjacent glyme molecules. The rapid formation of the methyl vinyl ether RC in the irradiated monoglyme was confirmed by the numerical simulation of the experimental curves of the time-resolved magnetic field effect. These findings suggest that the R'-O-CH═CH2(•+) formation is a typical decay pathway for the primary RCs in irradiated liquid glymes.

  13. Enhanced Sorbitol Production under Submerged Fermentation using Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Khan Nadiya Jan

    2017-04-01

    Full Text Available Background and Objective: Sorbitol is a non-toxic and slightly hygroscopic compound with different applications. Zymomonas mobiles produces sorbitol from sucrose or mixtures of glucose and fructose (formation is coupled with the dehydrogenation of glucose to glucono-δ- lactone. Recombinant Zymomonas mobilis may produce sorbitol and gluconic acid from glucose and fructose using different divalent metal ions with reduced the ethanol yield andsignificantly increased yield of sorbitol. Current study envisaged to alter the media components, physical process parameters and supplementation of amino acids for enhanced sorbitol production.Material and Methods: Several process variables were evaluated on sorbitol production including carbon sources (glucose, fructose, maltose, sucrose, carbon concentrations (5, 10, 20 and 25 g l-1, nitrogen sources (peptone, tryptone, yeast extract, beef extract and organic nitrogen mix, temperatures (25, 29, 33, 37, 41°C, pH (6, 6.5, 7 , 7.5 ,8, agitation rate (50, 100, 150, 200 rpm and amino acids (cysteine, cystine, tryptophanin batch cultivation ofLactobacillus plantarum NCIM 2912. Shake flask cultivation performed under optimum conditions like temperature 37°C, pH 7.0 and agitation rate of 150 rpm, resulted in enhanced sorbitol production. Comparative study of sorbitol production in solid state fermentation and submerged fermentation was also evaluated.Results and Conclusion: Batch cultivation under submerged conditions further performed in 7.5-l lab scale bioreactor (working volume 3.0-l under optimized conditions resulted in maximum cell biomass of 8.95±0.03 g g-1 and a sorbitol content of 9.78±0.04 g l-1 after 42.0 h of fermentation. Scale up study on bioreactor resulted in maximum sorbitol yield (Yp/x and productivity of 1.11 g g-1 and 0.50 g l-1 h under submerged fermentation, respectively.Conflict of interest: The authors declare no conflict of interest.

  14. 75 FR 51015 - Sorbitol From France: Notice of Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2010-08-18

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-427-001] Sorbitol From France: Notice... order on sorbitol from France. The review covers one producer/exporter of sorbitol, Syral S.A.S. (Syral... Products International (CP), domestic producers of sorbitol, we are now rescinding this administrative...

  15. Generic Schemes for Single-Molecule Kinetics. 3: Self-Consistent Pathway Solutions for Nonrenewal Processes.

    Science.gov (United States)

    Piephoff, D Evan; Cao, Jianshu

    2018-04-23

    We recently developed a pathway analysis framework (paper 1) for describing single-molecule kinetics for renewal (i.e., memoryless) processes based on the decomposition of a kinetic scheme into generic structures. In our approach, waiting time distribution functions corresponding to such structures are expressed in terms of self-consistent pathway solutions and concatenated to form measurable probability distribution functions (PDFs), affording a simple way to decompose and recombine a network. Here, we extend this framework to nonrenewal processes, which involve correlations between events, and employ it to formulate waiting time PDFs, including the first-passage time PDF, for a general kinetic network model. Our technique does not require the assumption of Poissonian kinetics, permitting a more general kinetic description than the usual rate approach, with minimal topological restrictiveness. To demonstrate the usefulness of this technique, we provide explicit calculations for our general model, which we adapt to two generic schemes for single-enzyme turnover with conformational interconversion. For each generic scheme, wherein the intermediate state(s) need not undergo Poissonian decay, the functional dependence of the mean first-passage time on the concentration of an external substrate is analyzed. When conformational detailed balance is satisfied, the enzyme turnover rate (related to the mean first-passage time) reduces to the celebrated Michaelis-Menten functional form, consistent with our previous work involving a similar scheme with all rate processes, thereby establishing further generality to this intriguing result. Our framework affords a general and intuitive approach for evaluating measurable waiting time PDFs and their moments, making it a potentially useful kinetic tool for a wide variety of single-molecule processes.

  16. D-sorbitol-induced phase control of TiO2 nanoparticles and its application for dye-sensitized solar cells

    Science.gov (United States)

    Shaikh, Shoyebmohamad F.; Mane, Rajaram S.; Min, Byoung Koun; Hwang, Yun Jeong; Joo, Oh-Shim

    2016-02-01

    Using a simple hydrothermal synthesis, the crystal structure of TiO2 nanoparticles was controlled from rutile to anatase using a sugar alcohol, D-sorbitol. Adding small amounts of D-sorbitol to an aqueous TiCl4 solution resulted in changes in the crystal phase, particle size, and surface area by affecting the hydrolysis rate of TiCl4. These changes led to improvements of the solar-to-electrical power conversion efficiency (η) of dye-sensitized solar cells (DSSC) fabricated using these nanoparticles. A postulated reaction mechanism concerning the role of D-sorbitol in the formation of rutile and anatase was proposed. Fourier-transform infrared spectroscopy, 13C NMR spectroscopy, and dynamic light scattering analyses were used to better understand the interaction between the Ti precursor and D-sorbitol. The crystal phase and size of the synthesized TiO2 nanocrystallites as well as photovoltaic performance of the DSSC were examined using X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and photocurrent density-applied voltage spectroscopy measurement techniques. The DSSC fabricated using the anatase TiO2 nanoparticles synthesized in the presence of D-sorbitol, exhibited an enhanced η (6%, 1.5-fold improvement) compared with the device fabricated using the rutile TiO2 synthesized without D-sorbitol.

  17. Temperature-Dependent Fermentation of d-Sorbitol in Escherichia coli O157:H7

    OpenAIRE

    Bouvet, O. M. M.; Pernoud, S.; Grimont, P. A. D.

    1999-01-01

    The influence of growth temperature on the ability to ferment d-sorbitol was investigated in Escherichia coli O157:H7. It was found that O157:H7 strains have a temperature-sensitive sorbitol phenotype. d-Sorbitol transport and sorbitol-6-phosphate dehydrogenase activities were expressed in sorbitol-fermenting cells grown at 30°C but only at a low level at 40°C. Sorbitol-positive variants able to transport d-sorbitol were easily selected at 30°C from culture of Sor− E. coli O157:H7 strains.

  18. Pra Desain Pabrik Sorbitol dari Tepung Tapioka dengan Hidrogenasi Katalitik

    Directory of Open Access Journals (Sweden)

    Hellen Kartika Dewi

    2014-03-01

    Full Text Available Sorbitol yang dikenal juga sebagai glusitol, adalah suatu gula alkohol yang dimetabolisme lambat di dalam tubuh. Sorbitol banyak digunakan sebagai bahan baku untuk industri barang konsumsi dan makanan seperti pasta gigi, permen, kosmetika, farmasi, vitamin C, termasuk industri tekstil dan kulit. Pembuatan sorbitol dari bahan baku tepung tapioka. Pabrik sorbitol ini direncanakan akan didirikan di Propinsi Jawa Tengah tepatnya di Kabupaten Batang dengan kapasitas produksi 30.000 ton/tahun. Proses produksi Sorbitol menggunakan proses hidrogenasi katalitik. Pembuatan sorbitol dari bahan baku pati melalui dua tahap proses utama yaitu proses perubahan starch menjadi glukosa melalui hidrolisa double enzym. Enzim yang digunakan yaitu α-amylase dan glukoamylase. Proses hidrogenasi katalitik dilakukan dengan mereaksikan larutan dekstrose dan gas hidrogen bertekanan tinggi dengan menambahkan katalis nikel dalam reaktor (Reaktor Hidrogenasi. Gas hidrogen masuk dari bawah reaktor secara bubbling dan larutan dekstrose diumpankan dari atas reaktor sehingga kontak yang terjadi semakin baik. Sorbitol yang di hasilkan dalam pradesain pabrik sorbitol ini dengan konsentrasi 58,2%. Pendirian pabrik sorbitol memerlukan biaya investasi modal tetap (fixed capital sebesar Rp 168.801.192.952, modal kerja (working capital  Rp 29.788.445.815, investasi total Rp 198.589.638.767, Biaya produksi per tahun Rp 368.832.813.809 dan  hasil penjualan per tahun Rp 540.000.078.750. Dari analisa ekonomi didapatkan BEP sebesar 26,32%. ROI sesudah pajak 48,5 %, POT sesudah pajak 2,14 tahun. Dari segi teknis dan ekonomis, pabrik ini layak untuk didirikan.

  19. Finite-bias electronic transport of molecules in a water solution

    KAUST Repository

    Rungger, Ivan; Chen, X.; Sanvito, Stefano; Schwingenschlö gl, Udo

    2010-01-01

    The effects of water wetting conditions on the transport properties of molecular nanojunctions are investigated theoretically by using a combination of empirical-potential molecular-dynamics and first-principles electronic-transport calculations. These are at the level of the nonequilibrium Green’s-function method implemented for self-interaction corrected density-functional theory. We find that water effectively produces electrostatic gating to the molecular junction with a gating potential determined by the time-averaged water dipole field. Such a field is large for the polar benzene-dithiol molecule, resulting in a transmission spectrum shifted by about 0.6 eV with respect to that of the dry junction. The situation is drastically different for carbon nanotubes (CNTs). In fact, because of their hydrophobic nature the gating is almost negligible so that the average transmission spectrum of wet Au/CNT/Au junctions is essentially the same as that in dry conditions. This suggests that CNTs can be used as molecular interconnects also in water-wet situations, for instance, as tips for scanning tunnel microscopy in solution or in biological sensors.

  20. Finite-bias electronic transport of molecules in a water solution

    KAUST Repository

    Rungger, Ivan

    2010-06-04

    The effects of water wetting conditions on the transport properties of molecular nanojunctions are investigated theoretically by using a combination of empirical-potential molecular-dynamics and first-principles electronic-transport calculations. These are at the level of the nonequilibrium Green’s-function method implemented for self-interaction corrected density-functional theory. We find that water effectively produces electrostatic gating to the molecular junction with a gating potential determined by the time-averaged water dipole field. Such a field is large for the polar benzene-dithiol molecule, resulting in a transmission spectrum shifted by about 0.6 eV with respect to that of the dry junction. The situation is drastically different for carbon nanotubes (CNTs). In fact, because of their hydrophobic nature the gating is almost negligible so that the average transmission spectrum of wet Au/CNT/Au junctions is essentially the same as that in dry conditions. This suggests that CNTs can be used as molecular interconnects also in water-wet situations, for instance, as tips for scanning tunnel microscopy in solution or in biological sensors.

  1. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinay, E-mail: drvinaygupta@netscape.net [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Upreti, Tanvi; Chand, Suresh [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)

    2013-12-16

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl) bis(6-fluoro-4-(5′-hexyl-[2,2′-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh{sub 2}){sub 2}: Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh{sub 2}){sub 2}: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe::60:40 leads to a short circuit current density (J{sub sc}) = 5.45 mA/cm{sup 2}, open circuit voltage (V{sub oc}) = 0.727 V, and fill factor (FF) = 51%, and a power conversion efficiency = 2.02% at 100 mW/cm{sup 2} under AM1.5G illumination. The J{sub sc} and FF are sensitive to the ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe, which is a crucial factor for the device performance.

  2. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    International Nuclear Information System (INIS)

    Gupta, Vinay; Upreti, Tanvi; Chand, Suresh

    2013-01-01

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl) bis(6-fluoro-4-(5′-hexyl-[2,2′-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh 2 ) 2 : Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh 2 ) 2 : CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh 2 ) 2 :CdSe::60:40 leads to a short circuit current density (J sc ) = 5.45 mA/cm 2 , open circuit voltage (V oc ) = 0.727 V, and fill factor (FF) = 51%, and a power conversion efficiency = 2.02% at 100 mW/cm 2 under AM1.5G illumination. The J sc and FF are sensitive to the ratio of p-DTS(FBTTh 2 ) 2 :CdSe, which is a crucial factor for the device performance

  3. The effect of increasing chitosan on the characteristics of bioplastic from starch talas (Colocasia esculenta) using plasticizer sorbitol

    Science.gov (United States)

    Ginting, M. H. S.; Lubis, M.; Sidabutar, T.; Sirait, T. P.

    2018-03-01

    The aims of this research to determine the profile of starch gelatinization, bioplastic and the effect of increasing chitosan and sorbitol to the properties of tensile strength and elongation of break bioplastic. Preparation of bioplastics was used by casting method, that is 30% w/v solution of starch mixed with chitosan solution (0.5 w/v; 1 w/v; 1.5 w/v; 2 w/v; and 2.5 w/v) and plasticizer sorbitol (10 % w/w; 20 % w/w; 30 % w/w; 40 % w/w and 50 % w/w) were heated using a hotplate magnetic stirrer at 750C. The results of Rapid Visco Analyzer (RVA) obtained by starch and bioplastic gelatinization temperature of 72.94°C 77.72°C with peak viscosity 6632 cP and 3476 cP. Analysis of Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) obtained the change a functional group of bioplastic OH at wave number 3765 cm-1 and uneven chitosan distribution, and there is still an empty fraction. The addition of chitosan and sorbitol had an effect on tensile strength and elongation at break, tensile strength and elongation at break the highest of 8.36 MPa and 22.06% in starch composition 30%, 2.5 w/v chitosan and sorbitol 30% w/w.

  4. Sensitization of glycine (spectrophotometric read-out) dosimetric system using sorbitol

    International Nuclear Information System (INIS)

    Shinde, S.H.; Mukherjee, T.

    2009-01-01

    Glycine spectrophotometric read-out systems have a useful dose range of 15-4000 Gy. An attempt was made to sensitize it using sorbitol as a sensitizer. Optimum compositions of aqueous acidic solutions of ferrous ammonium sulphate-xylenol orange (XO), i.e. FX and sorbitol-ferrous ammonium sulphate-xylenol orange, i.e. SFX, for 400 mg of glycine, which gives maximum dosimetric response for any given dose, were established. Molar absorption coefficient values of ferric-XO-glycine complex, i.e. ε-values, were determined for glycine system in FX and SFX. These values were found to be 8410 and 15,000 m 2 mol -1 respectively, indicating that an enhancement or sensitivity factor of about 1.78 can be achieved by sorbitol for glycine in SFX. This factor was further confirmed by measuring the gamma dose response of glycine in FX and in SFX for four different doses, viz. 37.8, 75.5, 151 and 302 Gy. It was observed that dose response of glycine in SFX is about 77% more than that of glycine in FX. The maximum variation observed in response of glycine in FX or SFX was found to be within ±1.5%.

  5. A-π-D-π-A Electron-Donating Small Molecules for Solution-Processed Organic Solar Cells: A Review.

    Science.gov (United States)

    Wang, Zhen; Zhu, Lingyun; Shuai, Zhigang; Wei, Zhixiang

    2017-11-01

    Organic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution-processed solar cells containing A-π-D-π-A-type small molecules and fullerenes have reached 11%. However, the method for designing high-performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A-π-D-π-A electron-donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Malabsorption of fructose-sorbitol mixtures. Interactions causing abdominal distress

    DEFF Research Database (Denmark)

    Rumessen, J J; Gudmand-Høyer, E

    1987-01-01

    Hydrogen breath tests were performed on 10 healthy adults after they had ingested a mixture of sorbitol and fructose, in which these substances were present in amounts corresponding to the individual absorption capacities. A significant malabsorption of this mixture was evident in 7 of 10 subjects....... The mixture caused mild to severe gastrointestinal distress in five subjects. When the carbohydrates were given separately, symptoms were absent. There was a significant correlation between the individual absorption capacities of fructose and of sorbitol. A mixture containing a similar amount of fructose......, but given as sucrose, and a similar amount of sorbitol was further given to four of the seven subjects showing malabsorption of the fructose-sorbitol mixture. Malabsorption now failed to appear, and symptoms were absent. These findings are of potential importance for the understanding of the physiologic...

  7. Pronounced microheterogeneity in a sorbitol-water mixture observed through variable temperature neutron scattering.

    Science.gov (United States)

    Chou, Shin G; Soper, Alan K; Khodadadi, Sheila; Curtis, Joseph E; Krueger, Susan; Cicerone, Marcus T; Fitch, Andrew N; Shalaev, Evgenyi Y

    2012-04-19

    In this study, the structure of concentrated d-sorbitol-water mixtures is studied by wide- and small-angle neutron scattering (WANS and SANS) as a function of temperature. The mixtures are prepared using both deuterated and regular sorbitol and water at a molar fraction of sorbitol of 0.19 (equivalent to 70% by weight of regular sorbitol in water). Retention of an amorphous structure (i.e., absence of crystallinity) is confirmed for this system over the entire temperature range, 100-298 K. The glass transition temperature, Tg, is found from differential scanning calorimetry to be approximately 200 K. WANS data are analyzed using empirical potential structure refinement, to obtain the site-site radial distribution functions (RDFs) and coordination numbers. This analysis reveals the presence of nanoscaled water clusters surrounded by (and interacting with) sorbitol molecules. The water clusters appear more structured compared to bulk water and, especially at the lowest temperatures, resemble the structure of low-density amorphous ice (LDA). Upon cooling to 100 K the peaks in the water RDFs become markedly sharper, with increased coordination number, indicating enhanced local (nanometer-scale) ordering, with changes taking place both above and well below the Tg. On the mesoscopic (submicrometer) scale, although there are no changes between 298 and 213 K, cooling the sample to 100 K results in a significant increase in the SANS signal, which is indicative of pronounced inhomogeneities. This increase in the scattering is partly reversed during heating, although some hysteresis is observed. Furthermore, a power law analysis of the SANS data indicates the existence of domains with well-defined interfaces on the submicrometer length scale, probably as a result of the appearance and growth of microscopic voids in the glassy matrix. Because of the unusual combination of small and wide scattering data used here, the present results provide new physical insight into the

  8. Direct catalytic production of sorbitol from waste cellulosic materials.

    Science.gov (United States)

    Ribeiro, Lucília Sousa; Órfão, José J de Melo; Pereira, Manuel Fernando Ribeiro

    2017-05-01

    Cotton wool, cotton textile, tissue paper and printing paper, all potential waste cellulosic materials, were directly converted to sorbitol using a Ru/CNT catalyst in the presence of H 2 and using only water as solvent, without any acids. Conversions up to 38% were attained for the raw substrates, with sorbitol yields below 10%. Ball-milling of the materials disrupted their crystallinity, allowing reaching 100% conversion of cotton wool, cotton textile and tissue paper after 4h, with sorbitol yields around 50%. Mix-milling these materials with the catalyst greatly enhanced their conversion rate, and the materials were efficiently converted to sorbitol with a yield around 50% in 2h. However, ball- and mix-milled printing paper presented a conversion of only 50% after 5h, with sorbitol yields of 7%. Amounts of sorbitol of 0.525, 0.511 and 0.559g could be obtained from 1g of cotton wool, cotton textile and tissue paper, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Non-climacteric ripening and sorbitol homeostasis in plum fruits.

    Science.gov (United States)

    Kim, Ho-Youn; Farcuh, Macarena; Cohen, Yuval; Crisosto, Carlos; Sadka, Avi; Blumwald, Eduardo

    2015-02-01

    During ripening fruits undergo several physiological and biochemical modifications that influence quality-related properties, such as texture, color, aroma and taste. We studied the differences in ethylene and sugar metabolism between two genetically related Japanese plum cultivars with contrasting ripening behaviors. 'Santa Rosa' (SR) behaved as a typical climacteric fruit, while the bud sport mutant 'Sweet Miriam' (SM) displayed a non-climacteric ripening pattern. SM fruit displayed a delayed ripening that lasted 120 days longer than that of the climacteric fruit. At the full-ripe stage, both cultivars reached similar final size and weight but the non-climacteric fruits were firmer than the climacteric fruits. Fully ripe non-climacteric plum fruits, showed an accumulation of sorbitol that was 2.5 times higher than that of climacteric fruits, and the increase in sorbitol were also paralleled to an increase in sucrose catabolism. These changes were highly correlated with decreased activity and expression of NAD(+)-dependent sorbitol dehydrogenase and sorbitol oxidase and increased sorbitol-6-phosphate dehydrogenase activity, suggesting an enhanced sorbitol synthesis in non-climacteric fruits. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Studies of muonium-substituted molecules in 2-propanone and in aqueous solutions of 2-propanone

    International Nuclear Information System (INIS)

    Cox, S.F.J.; Renzi, R. De; Scott, C.A.; Hill, A.; Symons, M.C.R.; Bucci, C.; Vecli, A.

    1984-04-01

    The paper deals with muonium substituted molecules, which are formed when positive muons are implanted in pure 2-propanone and in binary aqueous systems; and are studied by the muon spin rotation technique. Studies of muonium substituted molecules are discussed under five topic headings: hyperfine interaction, influence of the solvent, radical formation, diamagnetic fraction and linewidths. (U.K.)

  11. Trehalose and sorbitol alter the kinetic pattern of inactivation of glutamate dehydrogenase during drying in levitated microdroplets.

    Science.gov (United States)

    Lorenzen, Elke; Lee, Geoffrey

    2013-12-01

    A single-droplet acoustic levitator was used to determine the drying rate and the kinetics of inactivation of glutamate dehydrogenase in the presence of added trehalose or sorbitol. The solution was also spray dried under the same process condition of drying gas temperature on a bench-top machine. Both trehalose and sorbitol delay the point of onset of enzyme inactivation which lies after the critical point of drying. Both carbohydrates also reduce the apparent rate constant of inactivation calculated during the subsequent inactivation phase. The carbohydrates stabilise, therefore, the enzyme during droplet drying and particle formation mainly during the falling rate drying period. There is no difference between the stabilising effects of the two carbohydrates when examined as levitated single droplets. This suggests the importance of water replacement as a stabilising mechanism in the levitated droplets/particles. On spray drying, the trehalose stabilises the enzyme better than does the sorbitol at a drying gas (outlet) temperature of 60°C. This suggests glass formation with the trehalose but not the sorbitol during the very rapid drying process of small-atomised droplets in the spray dryer. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  12. Determination of structural and mechanical properties, diffractometry, and thermal analysis of chitosan and hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol

    Directory of Open Access Journals (Sweden)

    Jefferson Rotta

    2011-06-01

    Full Text Available In this work, the structural, mechanical, diffractometric, and thermal parameters of chitosan-hydroxypropylmethylcellulose (HPMC films plasticized with sorbitol were studied. Solutions of HPMC (2% w/v in water and chitosan (2% w/v in 2% acetic acid solution were prepared. The concentration of sorbitol used was 10% (w/w to both polymers. This solutions were mixed at different proportions (100/0; 70/30; 50/50; 30/70, and 0/100 of chitosan and HPMC, respectively, and 20 mL was cast in Petri dishes for further analysis of dried films. The miscibility of polymers was assessed by X-ray diffraction, scanning electronic microscopy (SEM, differential scanning calorimetry (DSC, and thermal gravimetric analysis (TGA. The results obtained indicate that the films are not fully miscible at a dry state despite the weak hydrogen bonding between the polymer functional groups.

  13. Use of a commercially available nucleating agent to control the morphological development of solution-processed small molecule bulk heterojunction organic solar cells

    KAUST Repository

    Sharenko, Alexander; Treat, Neil D.; Love, John A.; Toney, Michael F.; Stingelin, Natalie; Nguyen, Thuc-Quyen

    2014-01-01

    © the Partner Organisations 2014. The nucleating agent DMDBS is used to modulate the crystallization of solution-processed small molecule donor molecules in bulk heterojunction organic photovoltaic (BHJ OPV) devices. This control over donor molecule crystallization leads to a reduction in optimized thermal annealing times as well as smaller donor molecule crystallites, and therefore more efficient devices, when using an excessive amount of solvent additive. We therefore demonstrate the use of nucleating agents as a powerful and versatile processing strategy for solution-processed, small molecule BHJ OPVs. This journal is

  14. Use of a commercially available nucleating agent to control the morphological development of solution-processed small molecule bulk heterojunction organic solar cells

    KAUST Repository

    Sharenko, Alexander

    2014-08-12

    © the Partner Organisations 2014. The nucleating agent DMDBS is used to modulate the crystallization of solution-processed small molecule donor molecules in bulk heterojunction organic photovoltaic (BHJ OPV) devices. This control over donor molecule crystallization leads to a reduction in optimized thermal annealing times as well as smaller donor molecule crystallites, and therefore more efficient devices, when using an excessive amount of solvent additive. We therefore demonstrate the use of nucleating agents as a powerful and versatile processing strategy for solution-processed, small molecule BHJ OPVs. This journal is

  15. Study of dynamic behavior of EDTA molecule in solution using perturbed gamma-gamma angular correlation spectroscopy

    International Nuclear Information System (INIS)

    Amaral, Antonio A.; Silva, Andreia dos S.; Carbonari, Arthur W.; Lapolli, Andre L.

    2009-01-01

    In this work, PAC spectroscopy has been used to obtain the hyperfine parameters in EDTA molecules in solutions with pH 4.3 and pH 10.5 both measured at 77 K and 295 K using 181 Hf( 181 Ta) as probe nuclei. Both dynamic and static interactions were measured in aqueous solution, crystallized and re-hydrated samples in order to examine the motion and structure of EDTA-molecules. The hyperfine parameters, quadrupole interaction frequency (ν Q ), asymmetry (η), and the dynamic interaction frequency (λ) were obtained. The outcomes show that the rotational correlation time (τ CR ) is larger than the half-life of the intermediate state of probe nuclei. For samples with pH 4.3 and pH 10.5, it was observed an increase in ν Q when the temperature decreases, as expected, and also a variation of η, which is an evidence of a change in the EDTA molecule structure. 181 Hf is bound only to a single molecule site when the pH was 4.3, differently from the results for pH 10.5 sample, which showed two fractions with different ν Q indicating the possibility of 181 Hf being bonded to two different sites of the molecule. Measurements of the dehydrated sample presented different results leading us to conclude that the preparation procedure can causes alterations in the chemical bounds. Concluding, these results showed a systematic behavior of the 181 Hf-EDTA, with the variation of pH from 4 to approximately 11, and they are important to the knowledge of the dynamic behavior of this molecule. (author)

  16. Direct numerical solution of the Ornstein-Zernike integral equation and spatial distribution of water around hydrophobic molecules

    Science.gov (United States)

    Ikeguchi, Mitsunori; Doi, Junta

    1995-09-01

    The Ornstein-Zernike integral equation (OZ equation) has been used to evaluate the distribution function of solvents around solutes, but its numerical solution is difficult for molecules with a complicated shape. This paper proposes a numerical method to directly solve the OZ equation by introducing the 3D lattice. The method employs no approximation the reference interaction site model (RISM) equation employed. The method enables one to obtain the spatial distribution of spherical solvents around solutes with an arbitrary shape. Numerical accuracy is sufficient when the grid-spacing is less than 0.5 Å for solvent water. The spatial water distribution around a propane molecule is demonstrated as an example of a nonspherical hydrophobic molecule using iso-value surfaces. The water model proposed by Pratt and Chandler is used. The distribution agrees with the molecular dynamics simulation. The distribution increases offshore molecular concavities. The spatial distribution of water around 5α-cholest-2-ene (C27H46) is visualized using computer graphics techniques and a similar trend is observed.

  17. Numerical solutions of anharmonic vibration of BaO and SrO molecules

    Energy Technology Data Exchange (ETDEWEB)

    Pramudito, Sidikrubadi; Sanjaya, Nugraha Wanda [Theoretical Physics Division, Department of Physics, Bogor Agricultural University, Jalan Meranti Kampus IPB Dramaga Bogor 16680 (Indonesia); Sumaryada, Tony, E-mail: tsumaryada@ipb.ac.id [Theoretical Physics Division, Department of Physics, Bogor Agricultural University, Jalan Meranti Kampus IPB Dramaga Bogor 16680 (Indonesia); Computational Biophysics and Molecular Modeling Research Group (CBMoRG), Department of Physics, Bogor Agricultural University, Jalan Meranti Kampus IPB Dramaga Bogor 16680 (Indonesia)

    2016-03-11

    The Morse potential is a potential model that is used to describe the anharmonic behavior of molecular vibration between atoms. The BaO and SrO molecules, which are two almost similar diatomic molecules, were investigated in this research. Some of their properties like the value of the dissociation energy, the energy eigenvalues of each energy level, and the profile of the wavefunctions in their correspondence vibrational states were presented in this paper. Calculation of the energy eigenvalues and plotting the wave function’s profiles were performed using Numerov method combined with the shooting method. In general we concluded that the Morse potential solved with numerical methods could accurately produce the vibrational properties and the wavefunction behavior of BaO and SrO molecules from the ground state to the higher states close to the dissociation level.

  18. A naphthodithiophene-diketopyrrolopyrrole donor molecule for efficient solution-processed solar cells.

    Science.gov (United States)

    Loser, Stephen; Bruns, Carson J; Miyauchi, Hiroyuki; Ortiz, Rocío Ponce; Facchetti, Antonio; Stupp, Samuel I; Marks, Tobin J

    2011-06-01

    We report the synthesis, characterization, and first implementation of a naphtho[2,3-b:6,7-b']dithiophene (NDT)-based donor molecule in highly efficient organic photovoltaics (OPVs). When NDT(TDPP)(2) (TDPP = thiophene-capped diketopyrrolopyrrole) is combined with the electron acceptor PC(61)BM, a power conversion efficiency (PCE) of 4.06 ± 0.06% is achieved-a record for a PC(61)BM-based small-molecule OPV. The substantial PCE is attributed to the broad, high oscillator strength visible absorption, the ordered molecular packing, and an exceptional hole mobility of NDT(TDPP)(2). © 2011 American Chemical Society

  19. Skeletal Muscle Sorbitol Levels in Diabetic Rats with and without Insulin Therapy and Endurance Exercise Training

    Science.gov (United States)

    Sánchez, O. A.; Walseth, T. F.; Snow, L. M.; Serfass, R. C.; Thompson, L. V.

    2009-01-01

    Sorbitol accumulation is postulated to play a role in skeletal muscle dysfunction associated with diabetes. The purpose of this study was to determine the effects of insulin and of endurance exercise on skeletal muscle sorbitol levels in streptozotocin-induced diabetic rats. Rats were assigned to one experimental group (control sedentary, control exercise, diabetic sedentary, diabetic exercise, diabetic sedentary no-insulin). Diabetic rats received daily subcutaneous insulin. The exercise-trained rats ran on a treadmill (1 hour, 5X/wk, for 12 weeks). Skeletal muscle sorbitol levels were the highest in the diabetic sedentary no-insulin group. Diabetic sedentary rats receiving insulin had similar sorbitol levels to control sedentary rats. Endurance exercise did not significantly affect sorbitol levels. These results indicate that insulin treatment lowers sorbitol in skeletal muscle; therefore sorbitol accumulation is probably not related to muscle dysfunction in insulin-treated diabetic individuals. Endurance exercise did not influence intramuscular sorbitol values as strongly as insulin. PMID:20016800

  20. The metabolism of sorbitol and fructose in isolated chloroplasts of Santa Rosa plum leaves

    International Nuclear Information System (INIS)

    De Villiers, O.T.

    1979-01-01

    Aqueously as well as non-aqueously isolated chloroplasts from Santa Rosa plum leaves readily metabolised sorbitol- 14 C to fructose, glucose and sucrose. Likewise, fructose- 14 C was converted to sorbitol, glucose and sucrose [af

  1. Complexation of Polyelectrolytes with Hydrophobic Drug Molecules in Salt-Free Solution: Theory and Simulations.

    Science.gov (United States)

    Lei, Qun-Li; Hadinoto, Kunn; Ni, Ran

    2017-04-18

    The delivery and dissolution of poorly soluble drugs is challenging in the pharmaceutical industry. One way to significantly improve the delivery efficiency is to incorporate these hydrophobic small molecules into a colloidal polyelectrolyes(PE)-drug complex in their ionized states. Despite its huge application value, the general mechanism of PE collapse and complex formation in this system has not been well understood. In this work, by combining a mean-field theory with extensive molecular simulations, we unveil the phase behaviors of the system under dilute and salt-free conditions. We find that the complexation is a first-order-like phase transition triggered by the hydrophobic attraction between the drug molecules. Importantly, the valence ratio between the drug molecule and PE monomer plays a crucial role in determining the stability and morphology of the complex. Moreover, the sign of the zeta potential and the net charge of the complex are found to be inverted as the hydrophobicity of the drug molecules increases. Both theory and simulation indicate that the complexation point and complex morphology and the electrostatic properties of the complex have a weak dependence on chain length. Finally, the dynamics aspect of PE-drug complexation is also explored, and it is found that the complex can be trapped into a nonequilibrium glasslike state when the hydropobicity of the drug molecule is too strong. Our work gives a clear physical picture behind the PE-drug complexation phenomenon and provides guidelines to fabricate the colloidal PE-drug complex with the desired physical characteristics.

  2. Caloric utilization of sorbitol and isomalt in the rat

    International Nuclear Information System (INIS)

    Figdor, S.K.; Allingham, R.P.; Kita, D.A.; Hobbs, D.C.

    1987-01-01

    Sorbitol and isomalt are modified saccharides used to substitute for the physical properties of sucrose in various prepared foods. The merits of the various methods for determining caloric availability were reviewed. Balance and growth curve methods are inaccurate and inappropriate for determination of the caloric availability of these substances when present in diets at low concentrations, whereas the radiolabel disposition method is a direct and precise measure of utilization. Accordingly, the authors administered uniformly 14 C-labeled material to rats and collected excreta and expired air. The appearance of about half of the label in CO 2 indicated that, by comparison with labeled glucose, about 80% of the orally administered sorbitol and isomalt was calorically available to the rat. The high caloric availabilities of these materials were confirmed by the appearance in feces of only 14 and 12% of the administered label from sorbitol and isomalt, respectively

  3. 40 CFR 180.1262 - Sorbitol octanoate; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Sorbitol octanoate; exemption from the... Exemptions From Tolerances § 180.1262 Sorbitol octanoate; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of sorbitol octanoate in or on all...

  4. 75 FR 42380 - Revocation of Antidumping Duty Order on Sorbitol From France

    Science.gov (United States)

    2010-07-21

    ... Duty Order on Sorbitol From France AGENCY: Import Administration, International Trade Administration... sunset review of the antidumping duty order on sorbitol from France. See Initiation of Five-year... the existing antidumping duty order on sorbitol from France would not be likely to lead to...

  5. Selective on site separation and detection of molecules in diluted solutions with super-hydrophobic clusters of plasmonic nanoparticles

    KAUST Repository

    Gentile, Francesco T.; Coluccio, Maria Laura; Proietti Zaccaria, Remo; Francardi, Marco; Cojoc, Gheorghe; Perozziello, Gerardo; Raimondo, Raffaella; Candeloro, Patrizio; Di Fabrizio, Enzo M.

    2014-01-01

    Super-hydrophobic surfaces are bio-inspired interfaces with a superficial texture that, in its most common evolution, is formed by a periodic lattice of silicon micro-pillars. Similar surfaces reveal superior properties compared to conventional flat surfaces, including very low friction coefficients. In this work, we modified meso-porous silicon micro-pillars to incorporate networks of metal nano-particles into the porous matrix. In doing so, we obtained a multifunctional-hierarchical system in which (i) at a larger micrometric scale, the super-hydrophobic pillars bring the molecules dissolved in an ultralow-concentration droplet to the active sites of the device, (ii) at an intermediate meso-scale, the meso-porous silicon film adsorbs the low molecular weight content of the solution and, (iii) at a smaller nanometric scale, the aggregates of silver nano-particles would measure the target molecules with unprecedented sensitivity. In the results, we demonstrated how this scheme can be utilized to isolate and detect small molecules in a diluted solution in very low abundance ranges. The presented platform, coupled to Raman or other spectroscopy techniques, is a realistic candidate for the protein expression profiling of biological fluids. © 2014 the Partner Organisations.

  6. An introduction to radiation induced degradation of biological molecules in aqueous solutions

    International Nuclear Information System (INIS)

    Lal, Manohar

    1991-01-01

    Radiation chemistry of aqueous systems is the chemistry of H, OH, e aq - , H 3 O + and H 2 O * formed when a solute in aqueous solutions is exposed to ionising radiation. The pulse radiolysis technique has helped in the production, the detection and understanding of the reactions of primary species with solutes. A great deal of data on radiation biochemical studies e.g. degradation of DNA, its constituents and their protection, radiation protection and sensitisation, generation of superoxide ion and their reactions has already been reported but a great deal still needs to be done for the understanding of radiation biology. (author). 12 refs

  7. 1H NMR analysis of complexation of hydrotropic agents nicotinamide and caffeine with aromatic biologically active molecules in aqueous solution

    Science.gov (United States)

    Lantushenko, Anastasia O.; Mukhina, Yulia V.; Veselkov, Kyrill A.; Davies, David B.; Veselkov, Alexei N.

    2004-07-01

    NMR spectroscopy has been used to elucidate the molecular mechanism of solubilization action of hydrotropic agents nicotinamide (NA) and caffeine (CAF). Hetero-association of NA with riboflavine-mononucleotide (FMN) and CAF with low soluble in aqueous solution synthetic analogue of antibiotic actinomycin D, actinocyl-bis-(3-dimethylaminopropyl) amine (Actill), has been investigated by 500 MHz 1H NMR spectroscopy. Concentration and temperature dependences of proton chemical shifts have been analysed in terms of a statistical-thermodynamic model of indefinite self- and heteroassociation of aromatic molecules. The obtained results enable to conclude that NA-FMN and CAF-Actill intermolecular complexes are mainly stabilized by the stacking interactions of the aromatic chromophores. Hetero-association of the investigated molecules plays an important role in solubilization of aromatic drugs by hydrotropic agents nicotinamide and caffeine.

  8. Impact of the electron-transport layer on the performance of solution-processed small-molecule organic solar cells.

    Science.gov (United States)

    Long, Guankui; Wan, Xiangjian; Kan, Bin; Hu, Zhicheng; Yang, Xuan; Zhang, Yi; Zhang, Mingtao; Wu, Hongbing; Huang, Fei; Su, Shijian; Cao, Yong; Chen, Yongsheng

    2014-08-01

    Although the performance of polymer solar cells has been improved significantly recently through careful optimization with different interlayers for the same materials, more improvement is needed in this respect for small-molecule-based solar cells, particularly for the electron-transport layers (ETLs). In this work, three different solution-processed ETLs, PFN, ZnO nanoparticles, and LiF, were investigated and compared in the performance of small-molecule-based devices, and power conversion efficiencies (PCEs) of 8.32, 7.30, and 7.38% were achieved, respectively. The mechanism for the ETL-induced enhancement has been studied, and different ETLs have a significantly different impact on the device performance. The clearly improved performance of PFN is attributed to the combination of reduced bimolecular recombination and increased effective photon absorption in the active layer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. X-ray diffraction study on the structure of concentrated aqueous solutions involving alanine molecules with different optical activities

    International Nuclear Information System (INIS)

    Kameda, Yasuo; Okuyama, Aya; Amo, Yuko; Usuki, Takeshi; Kohara, Shinji

    2007-01-01

    X-ray diffraction measurements on aqueous 2.5 mol% DL-, L-, and D-alanine solutions in D 2 O were carried out at 26±2degC in order to obtain information concerning the difference in the hydrogen-bonded structure between aqueous solutions involving amino acid molecules with different optical activities. The difference function, Δi inter (Q), between intermolecular interference term observed for DL- and L-alanine and between DL- and D-alanine solutions both exhibited a first peak at Q=1.6 A -1 , followed by oscillatory features extending to higher-Q region, implying that there is a difference in the intermolecular structure is present between these solutions. The difference distribution function, Δg inter (r), obtained from the Fourier transform of the Δi inter (Q) between DL- and L-, and between DL- and D-alanine solutions showed an obvious negative peak at r=2.8 A, which was attributed to the nearest neighbor hydrogen-bonded O...O interaction. The least squares fitting analysis of the observed Δi inter (Q) showed that the intermolecular O...O distance and the difference in the coordination number between DL- and L-, and between DL- and D-alanine solutions are 2.76(2) A and -0.18(1), and 2.81(3) A and -0.18(1), respectively. It was concluded that the intermolecular hydrogen-bonded network in aqueous L- and D-alanine solutions is stronger than that in the DL-alanine solution. (author)

  10. Solution-Processed Organic Solar Cells from Dye Molecules: An Investigation of Diketopyrrolopyrrole:Vinazene Heterojunctions

    KAUST Repository

    Walker, Bright

    2012-01-25

    Although one of the most attractive aspects of organic solar cells is their low cost and ease of fabrication, the active materials incorporated into the vast majority of reported bulk heterojunction (BHJ) solar cells include a semiconducting polymer and a fullerene derivative, classes of materials which are both typically difficult and expensive to prepare. In this study, we demonstrate that effective BHJs can be fabricated from two easily synthesized dye molecules. Solar cells incorporating a diketopyrrolopyrrole (DPP)-based molecule as a donor and a dicyanoimidazole (Vinazene) acceptor function as an active layer in BHJ solar cells, producing relatively high open circuit voltages and power conversion efficiencies (PCEs) up to 1.1%. Atomic force microscope images of the films show that active layers are rough and apparently have large donor and acceptor domains on the surface, whereas photoluminescence of the blends is incompletely quenched, suggesting that higher PCEs might be obtained if the morphology could be improved to yield smaller domain sizes and a larger interfacial area between donor and acceptor phases. © 2011 American Chemical Society.

  11. Sorbitol dehydration into isosorbide in a molten salt hydrate medium

    NARCIS (Netherlands)

    Li, J.; Spina, A.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less

  12. Interaction of silicon nanoparticles with the molecules of bovine serum albumin in aqueous solutions

    International Nuclear Information System (INIS)

    Anenkova, K A; Sergeeva, I A; Petrova, G P; Fedorova, K V; Osminkina, L A; Timoshenko, Viktor Yu

    2011-01-01

    Using the method of photon-correlation spectroscopy, the coefficient of translational diffusion D t and the hydrodynamic radius R of the particles in aqueous solutions of the bovine serum albumin, containing silicon nanoparticles, are determined. The character of the dependence of these parameters on the concentration of the protein indicates the absence of interaction between the studied particles in the chosen range of albumin concentrations 0.2 - 1.0 mg mL -1 . (optical technologies in biophysics and medicine)

  13. Hardware solution for continuous time-resolved burst detection of single molecules in flow

    Science.gov (United States)

    Wahl, Michael; Erdmann, Rainer; Lauritsen, Kristian; Rahn, Hans-Juergen

    1998-04-01

    Time Correlated Single Photon Counting (TCSPC) is a valuable tool for Single Molecule Detection (SMD). However, existing TCSPC systems did not support continuous data collection and processing as is desirable for applications such as SMD for e.g. DNA-sequencing in a liquid flow. First attempts at using existing instrumentation in this kind of operation mode required additional routing hardware to switch between several memory banks and were not truly continuous. We have designed a hard- and software system to perform continuous real-time TCSPC based upon a modern solid state Time to Digital Converter (TDC). Short dead times of the fully digital TDC design combined with fast Field Programmable Gay Array logic permit a continuous data throughput as high as 3 Mcounts/sec. The histogramming time may be set as short as 100 microsecond(s) . Every histogram or every single fluorescence photon can be real-time tagged at 200 ns resolution in addition to recording its arrival time relative to the excitation pulse. Continuous switching between memory banks permits concurrent histogramming and data read-out. The instrument provides a time resolution of 60 ps and up to 4096 histogram channels. The overall instrument response function in combination with a low cost picosecond diode laser and an inexpensive photomultiplier tube was found to be 180 ps and well sufficient to measure sub-nanosecond fluorescence lifetimes.

  14. Modulating β-lactoglobulin nanofibril self-assembly at pH 2 using glycerol and sorbitol.

    Science.gov (United States)

    Dave, Anant C; Loveday, Simon M; Anema, Skelte G; Jameson, Geoffrey B; Singh, Harjinder

    2014-01-13

    β-Lactoglobulin (β-lg) forms fibrils when heated at 80 °C, pH 2, and low ionic strength (sorbitol (0-50% w/v) on β-lg self-assembly at pH 2. Glycerol and sorbitol stabilize native protein structure and modulate protein functionality by preferential exclusion. In our study, both polyols decreased the rate of β-lg self-assembly but had no effect on the morphology of fibrils. The mechanism of these effects was studied using circular dichroism spectroscopy and SDS-PAGE. Sorbitol inhibited self-assembly by stabilizing β-lg against unfolding and hydrolysis, resulting in fewer fibrillogenic species, whereas glycerol inhibited nucleation without inhibiting hydrolysis. Both polyols increased the viscosity of the solutions, but viscosity appeared to have little effect on fibril assembly, and we believe that self-assembly was not diffusion-limited under these conditions. This is in agreement with previous reports for other proteins assembling under different conditions. The phenomenon of peptide self-assembly can be decoupled from protein hydrolysis using glycerol.

  15. Effect of sorbitol on dough rheology and quality of sugar replaced cookies

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Shariati

    2018-02-01

    Full Text Available A high amount of sugar is used in bakery products, which may cause diabetes, high blood glucose levels and obesity. Due to these reasons, sugar is being replaced with substitutes. There is different carbohydrate-based sugar substitutes (polyols that can efficiently replace sugar. Among polyols, sorbitol is an efficient replacer that can mimic sugar with minimal effects on cookie quality. Effects of different sorbitol levels (0 to 12.5% were seen on the dough rheology. Mixographic studies showed that peak height and mixing time reduced with the addition of sorbitol. Farinographic studies showed that water absorption and the mixing tolerance index of dough reduced with the supplementation of sorbitol, whereas dough development time, arrival time, dough stability time and softening of dough increased. Extensographic studies revealed that sorbitol substitution produced hard, cohesive, adhesive and elastic dough. Sugar in cookies formulations was reduced from 100 to 50% by replacing with sorbitol 0 to 50%. Physical analysis of sorbitol containing cookies showed that the diameter and spread factor of cookies decreased with higher levels of sorbitol, whereas thickness, color, hardness and water activity of cookies increased. The calorific value of cookies decreased with the increasing levels of sorbitol. At upto 20% replacement of sugar, other parameters of cookies were not affected. Sensory evaluation of the cookies showed that hedonic points for sensory evaluation parameters reduced with the increasing levels of sorbitol, T2 (20% replacement showed maximum overall acceptability. Normal 0 false false false EN-GB X-NONE AR-SA

  16. Solution-Processed Small-Molecule Bulk Heterojunctions: Leakage Currents and the Dewetting Issue for Inverted Solar Cells.

    Science.gov (United States)

    Destouesse, Elodie; Chambon, Sylvain; Courtel, Stéphanie; Hirsch, Lionel; Wantz, Guillaume

    2015-11-11

    In organic photovoltaic (PV) devices based on solution-processed small molecules, we report here that the physicochemical properties of the substrate are critical for achieving high-performances organic solar cells. Three different substrates were tested: ITO coated with PSS, ZnO sol-gel, and ZnO nanoparticles. PV performances are found to be low when the ZnO nanoparticles layer is used. This performance loss is attributed to the formation of many dewetting points in the active layer, because of a relatively high roughness of the ZnO nanoparticles layer, compared to the other layers. We successfully circumvented this phenomenon by adding a small quantity of polystyrene (PS) in the active layer. The introduction of PS improves the quality of film forming and reduces the dark currents of solar cells. Using this method, high-efficiency devices were achieved, even in the case of substrates with higher roughness.

  17. Selective electrocatalytic oxidation of sorbitol to fructose and sorbose.

    Science.gov (United States)

    Kwon, Youngkook; de Jong, Ed; van der Waal, Jan Kees; Koper, Marc T M

    2015-03-01

    A new electrocatalytic method for the selective electrochemical oxidation of sorbitol to fructose and sorbose is demonstrated by using a platinum electrode promoted by p-block metal atoms. By the studying a range of C4, C5 and C6 polyols, it is found that the promoter interferes with the stereochemistry of the polyol and thereby modifies its reactivity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sorbitol counteracts high hydrostatic pressure-induced denaturation of inulin fructotransferase.

    Science.gov (United States)

    Li, Yungao; Miao, Ming; Liu, Miao; Jiang, Bo; Zhang, Tao; Chen, Xiangyin

    2014-09-01

    Inulin fructotransferase (IFTase), a novel hydrolase for inulin, was exposed to high hydrostatic pressure (HHP) at 400 and 600 MPa for 15 min in the presence or absence of sorbitol. Sorbitol protected the enzyme against HHP-induced activity loss. The relative residual activity increased nearly 3.1- and 3.8-fold in the presence of 3 mol/L sorbitol under 400 MPa and 600 MPa for 15 min, respectively. Circular dichroism results indicated that the original chaotic unfolding conformation of the enzyme under HHP shifted toward more ordered and impact with 3 mol/L sorbitol. Fluorescence and UV spectra results suggested that sorbitol prevented partially the unfolding of the enzyme and stabilized the conformation under high pressure. These results might be attributed to the binding of sorbitol on the surface of IFTase to rearrange and strengthen intra- and intermolecular hydrogen bonds. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Current characteristics of λ-DNA molecules/polystyrene nanoparticles in TBE buffer solution through micro/nanofluidic capillaries under DC electric field

    Science.gov (United States)

    Duan, Yifei; Zhao, Wei; Xue, Jing; Sun, Dan; Wang, Kaige; Wang, Guiren; Li, Junjie; Bai, Jintao; Gu, Changzhi

    2017-03-01

    In practical applications of biochips and bio-sensors, electrokinetic mechanisms are commonly employed to manipulate single bio-molecules and analyze their characteristics. To accurately and flexibly control the movement of single-molecule within micro/nanofluidic channels which are the basic components of Lab-chips, the current signals in micro/nanocapillaries filled with solutions of DNA molecules or polystyrene (PS) nanoparticles are systematically studied. Experimental results indicate that the current response along the micro/nanocapillaries can be significantly influenced by the diameter of the capillaries and the pH value of the solutions. Specifically, when there is only a pure (TBE) solution, the electric conductance does not monotonically decrease with decreasing the diameter of the capillaries, but slightly increases with decreasing the capillary diameter. When λ-DNA molecules or PS nanoparticles are added into the TBE buffer, the size effect on the electric conductance of the solutions are quite different. Although in the former, the electric conductance behaves differently from that in the pure TBE solution and decreases with the decreasing diameter, in the latter, the change is similar to that in the pure TBE solution. Besides, an abnormal ‘falling’ of the electric conductance is observed in a capillary with diameter of 200 nm. The investigation will significantly enhance the understanding on the electric properties of the solutions of biomolecules and particles in micro/nanofluidics. This is especially helpful for designing functional Lab-chip devices.

  20. Current characteristics of λ -DNA molecules/polystyrene nanoparticles in TBE buffer solution through micro/nanofluidic capillaries under DC electric field

    International Nuclear Information System (INIS)

    Duan, Yifei; Zhao, Wei; Xue, Jing; Sun, Dan; Wang, Kaige; Wang, Guiren; Bai, Jintao; Li, Junjie; Gu, Changzhi

    2017-01-01

    In practical applications of biochips and bio-sensors, electrokinetic mechanisms are commonly employed to manipulate single bio-molecules and analyze their characteristics. To accurately and flexibly control the movement of single-molecule within micro/nanofluidic channels which are the basic components of Lab-chips, the current signals in micro/nanocapillaries filled with solutions of DNA molecules or polystyrene (PS) nanoparticles are systematically studied. Experimental results indicate that the current response along the micro/nanocapillaries can be significantly influenced by the diameter of the capillaries and the pH value of the solutions. Specifically, when there is only a pure (TBE) solution, the electric conductance does not monotonically decrease with decreasing the diameter of the capillaries, but slightly increases with decreasing the capillary diameter. When λ -DNA molecules or PS nanoparticles are added into the TBE buffer, the size effect on the electric conductance of the solutions are quite different. Although in the former, the electric conductance behaves differently from that in the pure TBE solution and decreases with the decreasing diameter, in the latter, the change is similar to that in the pure TBE solution. Besides, an abnormal ‘falling’ of the electric conductance is observed in a capillary with diameter of 200 nm. The investigation will significantly enhance the understanding on the electric properties of the solutions of biomolecules and particles in micro/nanofluidics. This is especially helpful for designing functional Lab-chip devices. (paper)

  1. Photo-stability study of a solution-processed small molecule solar cell system: correlation between molecular conformation and degradation.

    Science.gov (United States)

    Newman, Michael J; Speller, Emily M; Barbé, Jérémy; Luke, Joel; Li, Meng; Li, Zhe; Wang, Zhao-Kui; Jain, Sagar M; Kim, Ji-Seon; Lee, Harrison Ka Hin; Tsoi, Wing Chung

    2018-01-01

    Solution-processed organic small molecule solar cells (SMSCs) have achieved efficiency over 11%. However, very few studies have focused on their stability under illumination and the origin of the degradation during the so-called burn-in period. Here, we studied the burn-in period of a solution-processed SMSC using benzodithiophene terthiophene rhodamine:[6,6]-phenyl C 71 butyric acid methyl ester (BTR:PC 71 BM) with increasing solvent vapour annealing time applied to the active layer, controlling the crystallisation of the BTR phase. We find that the burn-in behaviour is strongly correlated to the crystallinity of BTR. To look at the possible degradation mechanisms, we studied the fresh and photo-aged blend films with grazing incidence X-ray diffraction, UV-vis absorbance, Raman spectroscopy and photoluminescence (PL) spectroscopy. Although the crystallinity of BTR affects the performance drop during the burn-in period, the degradation is found not to originate from the crystallinity changes of the BTR phase, but correlates with changes in molecular conformation - rotation of the thiophene side chains, as resolved by Raman spectroscopy which could be correlated to slight photobleaching and changes in PL spectra.

  2. Electron-rich anthracene semiconductors containing triarylamine for solution-processed small-molecule organic solar cells.

    Science.gov (United States)

    Choi, Hyeju; Ko, Haye Min; Cho, Nara; Song, Kihyung; Lee, Jae Kwan; Ko, Jaejung

    2012-10-01

    New electron-rich anthracene derivatives containing triarylamine hole stabilizers, 2,6-bis[5,5'-bis(N,N'-diphenylaniline)-2,2'-bithiophen-5-yl]-9,10-bis-[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT-TPA) and 2,6-bis(5,5'-bis{4-[bis(9,9-dimethyl-9H-fluoren-2-yl)amino]phenyl}-2,2'-bithiophen-5-yl)-9,10-bis-[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT-bisDMFA), linked with π-conjugated bithiophene bridges, were synthesized and their photovoltaic characteristics were investigated in solution-processed small-molecule organic solar cells (SMOSCs). These new materials exhibited superior intramolecular charge transfer from triarylamine to anthracene, leading to a more electron-rich anthracene core that facilitated electron transfer into phenyl-C(61)-butyric acid methyl ester. Compared with TIPSAntBT and triarylamine, these materials show a threefold improvement in hole-transporting properties and better photovoltaic performance in solution-processed SMOSCs, with the best power conversion efficiency being 2.96 % at a high open-circuit voltage of 0.85 V. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Biomass electrochemistry : from cellulose to sorbitol

    NARCIS (Netherlands)

    Kwon, Youngkook

    2013-01-01

    The primary goal of this thesis is to study the potential role of electrochemistry in finding new routes for sustainable chemicals from biomass in aqueous-phase solutions. In order to assess the potential of electrochemistry in biomass conversion, we developed an online HPLC system by using a

  4. Computational modeling of chemical reactions and interstitial growth and remodeling involving charged solutes and solid-bound molecules.

    Science.gov (United States)

    Ateshian, Gerard A; Nims, Robert J; Maas, Steve; Weiss, Jeffrey A

    2014-10-01

    Mechanobiological processes are rooted in mechanics and chemistry, and such processes may be modeled in a framework that couples their governing equations starting from fundamental principles. In many biological applications, the reactants and products of chemical reactions may be electrically charged, and these charge effects may produce driving forces and constraints that significantly influence outcomes. In this study, a novel formulation and computational implementation are presented for modeling chemical reactions in biological tissues that involve charged solutes and solid-bound molecules within a deformable porous hydrated solid matrix, coupling mechanics with chemistry while accounting for electric charges. The deposition or removal of solid-bound molecules contributes to the growth and remodeling of the solid matrix; in particular, volumetric growth may be driven by Donnan osmotic swelling, resulting from charged molecular species fixed to the solid matrix. This formulation incorporates the state of strain as a state variable in the production rate of chemical reactions, explicitly tying chemistry with mechanics for the purpose of modeling mechanobiology. To achieve these objectives, this treatment identifies the specific theoretical and computational challenges faced in modeling complex systems of interacting neutral and charged constituents while accommodating any number of simultaneous reactions where reactants and products may be modeled explicitly or implicitly. Several finite element verification problems are shown to agree with closed-form analytical solutions. An illustrative tissue engineering analysis demonstrates tissue growth and swelling resulting from the deposition of chondroitin sulfate, a charged solid-bound molecular species. This implementation is released in the open-source program FEBio ( www.febio.org ). The availability of this framework may be particularly beneficial to optimizing tissue engineering culture systems by examining the

  5. Trehalose 6-phosphate signal is closely related to sorbitol in apple (Malus domestica Borkh. cv. Gala)

    Science.gov (United States)

    Zhang, Wen; Lunn, John E.; Feil, Regina; Wang, Yufei; Zhao, Jingjing; Tao, Hongxia; Zhao, Zhengyang

    2017-01-01

    ABSTRACT Trehalose-6-phosphate (Tre6P) is a precursor of trehalose, which is widespread in nature and greatly influences plant growth and development. Tre6P acts as a signal of carbon availability in many plants, but little is known about the function of Tre6P in rosaceous plants, which have specific sorbitol biosynthesis and transportation pathways. In the present study, Tre6P levels and Sorbitol:Tre6P ratios were analyzed in apple (Malus domestica, Borkh. cv. Gala). Tre6P levels were positively correlated with sorbitol content but negatively correlated with sucrose, glucose, and fructose content in developing fruit. However, under sorbitol-limited conditions, Tre6P levels were positively correlated with both sorbitol and sucrose. In the presence of different exogenous sugar supply, Tre6P levels increased corresponding with sorbitol, but this was not the case with sucrose. In addition, Tre6P content and sorbitol:Tre6P ratios were more highly correlated with ADP-glucose levels under sorbitol-limited conditions and fruit development stages, respectively. These results suggest that Tre6P is more closely related to sorbitol than other soluble sugars and has an important role in influencing carbon metabolism in apple. PMID:28069587

  6. Exposure to sorbitol during lactation causes metabolic alterations and genotoxic effects in rat offspring.

    Science.gov (United States)

    Cardoso, Felipe S; Araujo-Lima, Carlos F; Aiub, Claudia A F; Felzenszwalb, Israel

    2016-10-17

    Sorbitol is a polyol used by the food industry as a sweetener. Women are consuming diet and light products containing sorbitol during pregnancy and in the postnatal period to prevent themselves from excessive weight gain and maintain a slim body. Although there is no evidence for the genotoxicity of sorbitol in the perinatal period, this study focused on evaluating the effects of the maternal intake of sorbitol on the biochemical and toxicological parameters of lactating Wistar rat offspring after 14days of mother-to-offspring exposure. A dose-dependent reduction of offspring length was observed. An increase in sorbitol levels determined in the milk was also observed. However, we detected an inverse relationship between the exposition dose in milk fructose and triacylglycerols concentrations. There was an increase in the plasmatic levels of ALT, AST and LDLc and a decrease in proteins, cholesterol and glucose levels in the offspring. Sorbitol exposure caused hepatocyte genotoxicity, including micronuclei induction. Maternal sorbitol intake induced myelotoxicity and myelosuppression in their offspring. The Comet assay of the blood cells detected a dose-dependent genotoxic response within the sorbitol-exposed offspring. According to our results, sorbitol is able to induce important metabolic alterations and genotoxic responses in the exposed offspring. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Trehalose 6-phosphate signal is closely related to sorbitol in apple (Malus domestica Borkh. cv. Gala

    Directory of Open Access Journals (Sweden)

    Wen Zhang

    2017-02-01

    Full Text Available Trehalose-6-phosphate (Tre6P is a precursor of trehalose, which is widespread in nature and greatly influences plant growth and development. Tre6P acts as a signal of carbon availability in many plants, but little is known about the function of Tre6P in rosaceous plants, which have specific sorbitol biosynthesis and transportation pathways. In the present study, Tre6P levels and Sorbitol:Tre6P ratios were analyzed in apple (Malus domestica, Borkh. cv. Gala. Tre6P levels were positively correlated with sorbitol content but negatively correlated with sucrose, glucose, and fructose content in developing fruit. However, under sorbitol-limited conditions, Tre6P levels were positively correlated with both sorbitol and sucrose. In the presence of different exogenous sugar supply, Tre6P levels increased corresponding with sorbitol, but this was not the case with sucrose. In addition, Tre6P content and sorbitol:Tre6P ratios were more highly correlated with ADP-glucose levels under sorbitol-limited conditions and fruit development stages, respectively. These results suggest that Tre6P is more closely related to sorbitol than other soluble sugars and has an important role in influencing carbon metabolism in apple.

  8. Solution-processed small molecules as mixed host for highly efficient blue and white phosphorescent organic light-emitting diodes.

    Science.gov (United States)

    Fu, Qiang; Chen, Jiangshan; Shi, Changsheng; Ma, Dongge

    2012-12-01

    The widely used hole-transporting host 4,4',4″-tris(N-carbazolyl)-triphenylamine (TCTA) blended with either a hole-transporting or an electron-transporting small-molecule material as a mixed-host was investigated in the phosphorescent organic light-emitting diodes (OLEDs) fabricated by the low-cost solution-process. The performance of the solution-processed OLEDs was found to be very sensitive to the composition of the mixed-host systems. The incorporation of the hole-transporting 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) into TCTA as the mixed-host was demonstrated to greatly reduce the driving voltage and thus enhance the efficiency due to the improvement of hole injection and transport. On the basis of the mixed-host of TCTA:TAPC, we successfully fabricated low driving voltage and high efficiency blue and white phosphorescent OLEDs. A maximum forward viewing current efficiency of 32.0 cd/A and power efficiency of 25.9 lm/W were obtained in the optimized mixed-host blue OLED, which remained at 29.6 cd/A and 19.1 lm/W at the luminance of 1000 cd/m(2) with a driving voltage as low as 4.9 V. The maximum efficiencies of 37.1 cd/A and 32.1 lm/W were achieved in a single emissive layer white OLED based on the TCTA:TAPC mixed-host. Even at 1000 cd/m(2), the efficiencies still reach 34.2 cd/A and 23.3 lm/W and the driving voltage is only 4.6 V, which is comparable to those reported from the state-of-the-art vacuum-evaporation deposited white OLEDs.

  9. Colonic necrosis due to calcium polystyrene sulfonate (Kalimate not suspended in sorbitol

    Directory of Open Access Journals (Sweden)

    María Dolores Castillo-Cejas

    2013-04-01

    Full Text Available Cation-exchange resins are used in the management of hyperkalemia, particularly in patients with end-stage renal disease. These resins were associated with gastrointestinal tract lesions, especially sodium polystyrene sulfonate (Kayexalate mixed with sorbitol. We present a case of colonic necrosis after the administration of calcium polystyrene sulfonate (Kalimate not suspended in sorbitol.

  10. Conductivity, work function, and environmental stability of PEDOT:PSS thin films treated with sorbitol

    NARCIS (Netherlands)

    Nardes, A.M.; Kemerink, M.; Kok, de M.M.; Vinken, E.; Maturova, K.; Janssen, R.A.J.

    2008-01-01

    The electrical properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) thin films deposited from aqueous dispersion using different concentrations of sorbitol have been studied in detail. Although it is well known that sorbitol enhances the conductivity of PEDOT:PSS thin

  11. Polar silica-based stationary phases. Part II- Neutral silica stationary phases with surface bound maltose and sorbitol for hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Rathnasekara, Renuka; El Rassi, Ziad

    2017-07-28

    Two neutral polyhydroxylated silica bonded stationary phases, namely maltose-silica (MALT-silica) and sorbitol-silica (SOR-silica), have been introduced and chromatographically characterized in hydrophilic interaction liquid chromatography (HILIC) for a wide range of polar compounds. The bonding of the maltose and sorbitol to the silica surface was brought about by first converting bare silica to an epoxy-activated silica surface via reaction with γ-glycidoxypropyltrimethoxysilane (GPTMS) followed by attaching maltose and sorbitol to the epoxy surface in the presence of the Lewis acid catalyst BF 3 .ethereate. Both silica based columns offered the expected retention characteristics usually encountered for neutral polar surface. The retention mechanism is majorly based on solute' differential partitioning between an organic rich hydro-organic mobile phase (e.g., ACN rich mobile phase) and an adsorbed water layer on the surface of the stationary phase although additional hydrogen bonding was also responsible in some cases for solute retention. The MALT-silica column proved to be more hydrophilic and offered higher retention, separation efficiency and resolution than the SOR-silica column among the tested polar solutes such as derivatized mono- and oligosaccharides, weak phenolic acids, cyclic nucleotide monophosphate and nucleotide-5'-monophosphates, and weak bases, e.g., nucleobases and nucleosides. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. UNIQUAC interaction parameters for molecules with -OH groups on adjacent carbon atoms in aqueous solution determined by molecular mechanics - glycols, glycerol and glucose

    DEFF Research Database (Denmark)

    Jonsdottir, Svava Osk; Klein, R. A.

    1997-01-01

    UNIQUAC interaction parameters have been determined, using molecular mechanics calculations, for 1,2-ethanediol, 1,2-propanediol, glycerol and glucose with water in aqueous solution. Conformational space for individual pairs of molecules was explored using a stochastic method, the Boltzmann Jump...

  13. EFFECT OF XYLITOL AND SORBITOL IN CHEWING-GUMS ON MUTANS STREPTOCOCCI, PLAQUE PH AND MINERAL LOSS OF ENAMEL

    NARCIS (Netherlands)

    WENNERHOLM, K; ARENDS, J; BIRKHED, D; RUBEN, J; EMILSON, CG; DIJKMAN, AG

    1994-01-01

    Seventeen subjects with more than 3 x 10(5) mutans streptococci per millilitre of saliva completed this randomised, cross-over study. Four different chewing-gums, containing: (1) 70% xylitol, (2) 35% xylitol + 35% sorbitol, (3) 17.5% xylitol + 52.5% sorbitol, and (4) 70% sorbitol, were tested. The

  14. Sorbitol dehydrogenase of Aspergillus niger, SdhA, is part of the oxido-reductive D-galactose pathway and essential for D-sorbitol catabolism.

    Science.gov (United States)

    Koivistoinen, Outi M; Richard, Peter; Penttilä, Merja; Ruohonen, Laura; Mojzita, Dominik

    2012-02-17

    In filamentous fungi D-galactose can be catabolised through the oxido-reductive and/or the Leloir pathway. In the oxido-reductive pathway D-galactose is converted to d-fructose in a series of steps where the last step is the oxidation of d-sorbitol by an NAD-dependent dehydrogenase. We identified a sorbitol dehydrogenase gene, sdhA (JGI53356), in Aspergillus niger encoding a medium chain dehydrogenase which is involved in D-galactose and D-sorbitol catabolism. The gene is upregulated in the presence of D-galactose, galactitol and D-sorbitol. An sdhA deletion strain showed reduced growth on galactitol and growth on D-sorbitol was completely abolished. The purified enzyme converted D-sorbitol to D-fructose with K(m) of 50±5 mM and v(max) of 80±10 U/mg. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  15. Direct sorbitol proton exchange membrane fuel cell using moderate catalyst loadings

    International Nuclear Information System (INIS)

    Oyarce, Alejandro; Gonzalez, Carlos; Lima, Raquel Bohn; Lindström, Rakel Wreland; Lagergren, Carina; Lindbergh, Göran

    2014-01-01

    Highlights: •The performance of a direct sorbitol fuel cell was evaluated at different temperatures. •The performance was compared to the performance of a direct glucose fuel cell. •The mass specific peak power density of the direct sorbitol fuel cell was 3.6 mW mg −1 totalcatalystloading at 80 °C. •Both sorbitol and glucose fuel cell suffer from deactivation. -- Abstract: Recent progress in biomass hydrolysis has made it interesting to study the use of sorbitol for electricity generation. In this study, sorbitol and glucose are used as fuels in proton exchange membrane fuel cells having 0.9 mg cm −2 PtRu/C at the anode and 0.3 mg cm −2 Pt/C at the cathode. The sorbitol oxidation was found to have slower kinetics than glucose oxidation. However, at low temperatures the direct sorbitol fuel cell shows higher performance than the direct glucose fuel cell, attributed to a lower degree of catalyst poisoning. The performance of both fuel cells is considerably improved at higher temperatures. High temperatures lower the poisoning, allowing the direct glucose fuel cell to reach a higher performance than the direct sorbitol fuel cell. The mass specific peak power densities of the direct sorbitol and direct glucose fuel cells at 65 °C was 3.2 mW mg −1 catalyst and 3.5 mW mg −1 catalyst , respectively. Both of these values are one order of magnitude larger than mass specific peak power densities of earlier reported direct glucose fuel cells using proton exchange membranes. Furthermore, both the fuel cells showed a considerably decrease in performance with time, which is partially attributed to sorbitol and glucose crossover poisoning the Pt/C cathode

  16. Effects of sorbitol on porcine oocyte maturation and embryo development in vitro.

    Science.gov (United States)

    Lin, Tao; Zhang, Jin Yu; Diao, Yun Fei; Kang, Jung Won; Jin, Dong-Il

    2015-04-01

    In the present study, a porcine system was supplemented with sorbitol during in vitro maturation (IVM) or in vitro culture (IVC), and the effects of sorbitol on oocyte maturation and embryonic development following parthenogenetic activation were assessed. Porcine immature oocytes were treated with different concentrations of sorbitol during IVM, and the resultant metaphase II stage oocytes were activated and cultured in porcine zygote medium-3 (PZM-3) for 7 days. No significant difference was observed in cumulus expansion and the nuclear maturation between the control and sorbitol-treated groups, with the exception of the 100 mM group, which showed significantly decreased nuclear maturation and cumulus expansion. There was no significant difference in the intracellular reactive oxygen species (ROS) levels between oocytes matured with 10 or 20 mM sorbitol and control groups, but 50 and 100 mM groups had significantly higher ROS levels than other groups. The 20 mM group showed significant increases in intracellular glutathione and subsequent blastocyst formation rates following parthenogenetic activation compared with the other groups. During IVC, supplementation with sorbitol significantly reduced blastocyst formation and increased the apoptotic index compared with the control. The apoptotic index of blastocysts from the sorbitol-treated group for entire culture period was significantly higher than those of the partially sorbitol-exposed groups. Based on these findings, it can be concluded that the addition of a low concentration of sorbitol (20 mM) during IVM of porcine oocytes benefits subsequent blastocyst development and improves embryo quality, whereas sorbitol supplement during IVC has a negative effect on blastocyst formation.

  17. Real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentration by electromagnetic sensing.

    Science.gov (United States)

    Harnsoongnoen, Supakorn; Wanthong, Anuwat

    2017-10-01

    Magnetic sensing at microwave frequencies for real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations is reported. The sensing element was designed based on a coplanar waveguide (CPW) loaded with a split ring resonator (SRR), which was fabricated on a DiClad 880 substrate with a thickness of 1.6mm and relative permittivity (ε r ) of 2.2. The magnetic sensor was connected to a Vector Network Analyzer (VNA) and the electromagnetic interaction between the samples and sensor was analyzed. The magnitude of the transmission coefficient (S 21 ) was used as an indicator to detect the solution sample concentrations ranging from 0.04 to 0.20g/ml. The experimental results confirmed that the developed system using microwaves for the real-time monitoring of sucrose, sorbitol, d-glucose and d-fructose concentrations gave unique results for each solution type and concentration. Moreover, the proposed sensor has a wide dynamic range, high linearity, fast operation and low-cost. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Femtosecond Mid-Infrared Study of the Aqueous Solution Photochemistry of a CO-Releasing Molecule (CORM

    Directory of Open Access Journals (Sweden)

    Schatzschneider U.

    2013-03-01

    Full Text Available Ultraviolet irradiation of CO-releasing molecules (CORMs in water eventually leads to the loss of several carbon monoxide ligands.We show for an exemplary manganese tricarbonyl CORM that only one ligand is photolyzed off on an ultrafast timescale and that some molecules may undergo geminate recombination.

  19. Stochastic models (cooperative and non-cooperative) for NMR analysis of the hetero-association of aromatic molecules in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Evstigneev, Maxim P. [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine)], E-mail: max_evstigneev@mail.ru; Davies, David B. [School of Biological and Chemical Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX (United Kingdom); Veselkov, Alexei N. [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine)

    2006-01-25

    Stochastic cooperative (STOCH-C) and non-cooperative (STOCH-NC) models have been developed for NMR analysis of the hetero-association of aromatic compounds in solution, in order to take into account all physically meaningful association reactions of molecules in which there are no limitations on the lengths of the aggregates and complexes. These algorithmical approaches are compared with previously published basic (BASE) and generalized (GEN) analytical statistical thermodynamical models of hetero-association of biologically active aromatic molecules using the same sets of published NMR data measured under the same solution conditions (0.1 M phosphate buffer, pD = 7.1, T = 298 K). It is shown that, within experimental errors, the BASE analytical model may be used to describe molecular systems characterized by relatively small contributions of hetero-association reactions, whereas the GEN model may be applied to hetero-association reactions of any aromatic compound with different self-association properties. The STOCH-C computational algorithm enabled the effect on hetero-association of the interactions of molecules with different cooperativity parameters of self-association to be estimated for the first time and it is proposed that the algorithm for the stochastic models has great potential for detailed investigation and understanding of the interactions of aromatic molecules in solution.

  20. Stochastic models (cooperative and non-cooperative) for NMR analysis of the hetero-association of aromatic molecules in aqueous solution

    International Nuclear Information System (INIS)

    Evstigneev, Maxim P.; Davies, David B.; Veselkov, Alexei N.

    2006-01-01

    Stochastic cooperative (STOCH-C) and non-cooperative (STOCH-NC) models have been developed for NMR analysis of the hetero-association of aromatic compounds in solution, in order to take into account all physically meaningful association reactions of molecules in which there are no limitations on the lengths of the aggregates and complexes. These algorithmical approaches are compared with previously published basic (BASE) and generalized (GEN) analytical statistical thermodynamical models of hetero-association of biologically active aromatic molecules using the same sets of published NMR data measured under the same solution conditions (0.1 M phosphate buffer, pD = 7.1, T = 298 K). It is shown that, within experimental errors, the BASE analytical model may be used to describe molecular systems characterized by relatively small contributions of hetero-association reactions, whereas the GEN model may be applied to hetero-association reactions of any aromatic compound with different self-association properties. The STOCH-C computational algorithm enabled the effect on hetero-association of the interactions of molecules with different cooperativity parameters of self-association to be estimated for the first time and it is proposed that the algorithm for the stochastic models has great potential for detailed investigation and understanding of the interactions of aromatic molecules in solution

  1. Production of sorbitol and ethanol from Jerusalem artichokes by Saccharomyces cerevisiae ATCC 36859

    Energy Technology Data Exchange (ETDEWEB)

    Duvnjak, Z.; Duan, Z.D. (Ottawa Univ., ON (Canada). Dept. of Chemical Engineering); Turcotte, G. (Acadia Univ., Wolfville, NS (Canada). Dept. of Food Science)

    1991-09-01

    This study shows the possible use of Jerusalem artichokes for the production of sorbitol and ethanol by Saccharomyces cerevisiae ATCC 36859. Ethanol was produced from the beginning of the process, while sorbitol production started after glucose had been entirely consumed from Jerusalem artichoke (J.a.) juice. The importance of yeast extract and inoculum concentrations on the production of sorbitol from the above raw material was demonstrated. With a low initial biomass concentration sorbitol was not produced in pure J.a. juice. When the juice was supplemented with 3% yeast extract, the concentration of sorbitol was 4.6%. The sorbitol, ethanol and biomass yields (gram of product produced per gram of sugars consumed) were 0.259, 0.160 and 0.071 at the end of the process respectively. Adding glucose to increase its concentration to about 9% in the J.a. juice with 3% yeast extract had a positive effect on the production of ethanol, while commencement of the production of sorbitol was delayed and its final concentration was less than 50% of its concentration in the medium without added glucose. The effect of glucose was much stronger when it was added during the process than when added at the beginning of the process. (orig.).

  2. Effect of Sorbitol Plasticizer on the Structure and Properties of Melt Processed Polyvinyl Alcohol Films.

    Science.gov (United States)

    Tian, Huafeng; Liu, Di; Yao, Yuanyuan; Ma, Songbai; Zhang, Xing; Xiang, Aimin

    2017-12-01

    Poly (vinyl alcohol) (PVA) possesses wide applications as food packaging materials, but is difficult to melt process for its strong inter/intra hydrogen bonding. In this work, flexible PVA films with different content of sorbitol plasticizers were prepared by melt processing with the assistance of water. And the influence of sorbitol plasticizer content on the crystallinity, optical transparency, water-retaining capability, mechanical properties, thermal stability and oxygen and water permeability were investigated. The results indicated that sorbitol dramatically improved the melt processing ability of PVA. Sorbitol could interact with PVA to form strong hydrogen bonding interactions, which would decrease the original hydrogen bonding of the matrix, resulting in the decrease of crystallinity degrees. The glass transition, melting and crystallization peak temperatures decreased with the increase of sorbitol. All the films exhibited fine optical transparency. The water retaining capability were improved with the increase of sorbitol. Especially, an increase in elongation at break and decrease in Young's modulus and tensile strength were observed indicating good plasticizing effect of sorbitol on PVA films. In addition, the PVA films prepared in this work exhibited fine barrier properties against oxygen and water, suggesting wide application potential as packaging materials. © 2017 Institute of Food Technologists®.

  3. Sorbitol crystallization-induced aggregation in frozen mAb formulations.

    Science.gov (United States)

    Piedmonte, Deirdre Murphy; Hair, Alison; Baker, Priti; Brych, Lejla; Nagapudi, Karthik; Lin, Hong; Cao, Wenjin; Hershenson, Susan; Ratnaswamy, Gayathri

    2015-02-01

    Sorbitol crystallization-induced aggregation of mAbs in the frozen state was evaluated. The effect of protein aggregation resulting from sorbitol crystallization was measured as a function of formulation variables such as protein concentration and pH. Long-term studies were performed on both IgG1 and IgG2 mAbs over the protein concentration range of 0.1-120 mg/mL. Protein aggregation was measured by size-exclusion HPLC (SE-HPLC) and further characterized by capillary-electrophoresis SDS. Sorbitol crystallization was monitored and characterized by subambient differential scanning calorimetry and X-ray diffraction. Aggregation due to sorbitol crystallization is inversely proportional to both protein concentration and formulation pH. At high protein concentrations, sorbitol crystallization was suppressed, and minimal aggregation by SE-HPLC resulted, presumably because of self-stabilization of the mAbs. The glass transition temperature (Tg ') and fragility index measurements were made to assess the influence of molecular mobility on the crystallization of sorbitol. Tg ' increased with increasing protein concentration for both mAbs. The fragility index decreased with increasing protein concentration, suggesting that it is increasingly difficult for sorbitol to crystallize at high protein concentrations. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Ileocolic Perforation Secondary to Sodium Polystyrene Sulfonate in Sorbitol Use: A Case Report

    Directory of Open Access Journals (Sweden)

    Vincent Trottier

    2009-01-01

    Full Text Available Hyperkalemia is a common condition encountered in medical and surgical patients. It can lead to various complications including cardiac arrhythmias. Sodium polystyrene sulfonate (SPS in sorbitol is an ion-exchange resin that can be used to treat hyperkalemia. It can be used in enema or in oral form. The present article describes the case of an intensive care unit patient who experienced severe, diffuse, intestinal perforation induced by the use of SPS-sorbitol, requiring multiple laparotomies, followed by a brief review of the relevant literature and recommendations regarding the use of SPS-sorbitol.

  5. Ileocolic perforation secondary to sodium polystyrene sulfonate in sorbitol use: A case report

    Science.gov (United States)

    Trottier, Vincent; Drolet, Sébastien; Morcos, Mohib W

    2009-01-01

    Hyperkalemia is a common condition encountered in medical and surgical patients. It can lead to various complications including cardiac arrhythmias. Sodium polystyrene sulfonate (SPS) in sorbitol is an ion-exchange resin that can be used to treat hyperkalemia. It can be used in enema or in oral form. The present article describes the case of an intensive care unit patient who experienced severe, diffuse, intestinal perforation induced by the use of SPS-sorbitol, requiring multiple laparotomies, followed by a brief review of the relevant literature and recommendations regarding the use of SPS-sorbitol. PMID:19826644

  6. The effect of glicerol and sorbitol plasticizers toward disintegration time of phyto-capsules

    Science.gov (United States)

    Pudjiastuti, Pratiwi; Hendradi, Esti; Wafiroh, Siti; Harsini, Muji; Darmokoesoemo, Handoko

    2016-03-01

    The aim of research is determining the effect of glycerol and sorbitol toward the disintegration time of phyto-capsules, originated capsules from plant polysaccharides. Phyto-capsules were made from polysaccharides and 0.5% (v/v) of glycerol and sorbitol of each. The seven capsules of each were determined the disintegration time using Erweka disintegrator. The mean of disintegration time of phyto-capsules without plasticizers, with glycerol and sorbitol were 25'30"; 45'15" and 35'30" respectively. The color and colorless gelatin capsules showed the mean of disintegration time 7'30" and 2'35" respectively.

  7. Reliable structural interpretation of small-angle scattering data from bio-molecules in solution--the importance of quality control and a standard reporting framework.

    Science.gov (United States)

    Jacques, David A; Guss, Jules Mitchell; Trewhella, Jill

    2012-05-17

    Small-angle scattering is becoming an increasingly popular tool for the study of bio-molecular structures in solution. The large number of publications with 3D-structural models generated from small-angle solution scattering data has led to a growing consensus for the need to establish a standard reporting framework for their publication. The International Union of Crystallography recently established a set of guidelines for the necessary information required for the publication of such structural models. Here we describe the rationale for these guidelines and the importance of standardising the way in which small-angle scattering data from bio-molecules and associated structural interpretations are reported.

  8. Alternate economical starchy substrates for the production of 70% sorbitol

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, C.M. (Sarabhai Research Centre, Baroda (India). Industrial Enzymes Dept.); Nehete, P.N. (Sarabhai Research Centre, Baroda (India). Industrial Fermentation Div.); Shah, D.N. (GSFC Research and Development Centre, Fertilizernagar (India). Biotechnology Dept.); Shah, N.K. (Armour Chemicals Pvt. Ltd., Ankleshwar (India)); Shankar, V. (National Chemical Lab., Pune (India). Biochemistry Div.); Kothari, R.M. (Thapar Corporate Research and Development Centre, Patiala (India). Biotechnology Div.)

    1991-03-01

    In view of the soaring prices of corn and tapioca starch, use of their hydrolysate in the production of 70% sorbitol became less remunerative. Therefore, an economical alternative is explored by using hydrolysates of cereal flours, namely, rice (Oryzae sativa), wheat (Triticum aestivum), jowar (Sorghum vulgare) and bajra (Pennisetum typhoideum). A protocol is devised to (a) prepare their high DE hydrolysates, (b) purify it after saccharification, (c) monitor the chemical chracteristics of concentrated hydrolysate, as feedstock for Raney nickel catalyzed pressure hydrogenation and (d) finally prepare 70% sorbital. Merits and demerits of hydrolysates of these cereal flours are discussed in terms of operational limitations and percentage recovery, the governing factors for their industrial acceptability. Rice flour hydrolysate appears to be an alternative substrate, operationally and economically. (orig.).

  9. Organic molecules based on dithienyl-2,1,3-benzothiadiazole as new donor materials for solution-processed organic photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhonglian; Fan, Benhu; Ouyang, Jianyong [Department of Materials Science and Engineering, National University of Singapore, Singapore 117574 (Singapore); Xue, Feng [Department of Chemistry, National University of Singapore, Singapore 117573 (Singapore); Adachi, Chihaya [Center for Future Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan)

    2010-12-15

    Polymers based on dithienyl-2,1,3-benzothiadiazole (TBT) have received strong attention as the donor materials of polymer photovoltaic cells (PVs), since they can have a low band gap. But soluble small organic molecules based on TBT have been rarely studied. This paper reports the synthesis of two small organic molecules based on TBT and their application as the donor materials of solution-processed bulk heterojunction organic photovoltaic cells (OPVs). These compounds were soluble in common organic solvents, such as chloroform, chlorobenzene and tetrahydrofuran. They have band gaps comparable to poly(3-hexylthiophene) (P3HT) and lower HOMO and LUMO (HOMO: highest occupied molecular orbital, LUMO: lowest unoccupied molecular orbital) levels than P3HT. These molecules and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were used as the donors and acceptor to fabricate bulk heterojunction OPVs through solution processing. After optimization of the experimental conditions, power conversion efficiency (PCE) of 0.66% was achieved on the solution-processed OPVs under AM 1.5G, 100 mW cm{sup -2} illumination. (author)

  10. Perylene-Diimide Based Donor-Acceptor-Donor Type Small-Molecule Acceptors for Solution-Processable Organic Solar Cells

    Science.gov (United States)

    Ganesamoorthy, Ramasamy; Vijayaraghavan, Rajagopalan; Sakthivel, Pachagounder

    2017-12-01

    Development of nonfullerene acceptors plays an important role in the commercial availability of plastic solar cells. We report herein synthesis of bay-substituted donor-acceptor-donor (D-A-D)-type perylene diimide (PDI)-based small molecules (SM-1 to SM-4) by Suzuki coupling method and their use as acceptors in bulk heterojunction organic solar cells (BHJ-OSCs) with poly(3-hexylthiophene) (P3HT) polymer donor. We varied the number of electron-rich thiophene units and the solubilizing side chains and also evaluated the optical and electrochemical properties of the small molecules. The synthesized small molecules were confirmed by Fourier-transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and high-resolution mass spectroscopy (HR-MS). The small molecules showed extensive and strong absorption in the ultraviolet-visible (UV-Vis) region up to 750 nm, with bandgap (E_{{g}}^{{opt}} ) reduced below use as electron-accepting materials. The small molecules showed good thermal stability up to 300°C. BHJ-OSCs with SM-1 and P3HT polymer donor showed maximum power conversion efficiency (PCE) of 0.19% with V oc of 0.30 V, J sc of 1.72 mA cm-2, and fill factor (FF) of 37%. The PCE decreased with the number of thiophene units. The PCE of SM-2 was lower than that of SM-1. This difference in PCE can be explained by the higher aggregation tendency of the bithiophene compared with the thiophene unit. Introduction of the solubilizing group in the bay position increased the aggregation property, leading to much lower PCE than for the small molecules without solubilizing group.

  11. Molar concentrations of sorbitol and polyethylene glycol inhibit the Plasmodium aquaglyceroporin but not that of E. coli: involvement of the channel vestibules.

    Science.gov (United States)

    Song, Jie; Almasalmeh, Abdulnasser; Krenc, Dawid; Beitz, Eric

    2012-05-01

    The aquaglyceroporins of Escherichia coli, EcGlpF, and of Plasmodium falciparum, PfAQP, are probably the best characterized members of the solute-conducting aquaporin (AQP) subfamily. Their crystal structures have been elucidated and numerous experimental and theoretical analyses have been conducted. However, opposing reports on their rates of water permeability require clarification. Hence, we expressed EcGlpF and PfAQP in yeast, prepared protoplasts, and compared water and glycerol permeability of both aquaglyceroporins in the presence of different osmolytes, i.e. sucrose, sorbitol, PEG300, and glycerol. We found that water permeability of PfAQP strongly depends on the external osmolyte, with full inhibition by sorbitol, and increasing water permeability when glycerol, PEG300, and sucrose were used. EcGlpF expression did not enhance water permeability over that of non-expressing control protoplasts regardless of the osmolyte. Glycerol permeability of PfAQP was also inhibited by sorbitol, but to a smaller extent, whereas EcGlpF conducted glycerol independently of the osmolyte. Mixtures of glycerol and urea passed PfAQP equally well under isosmotic conditions, whereas under hypertonic conditions in a countercurrent with water, glycerol was clearly preferred over urea. We conclude that PfAQP has high and EcGlpF low water permeability, and explain the inhibiting effect of sorbitol on PfAQP by its binding to the extracellular vestibule. The preference for glycerol under hypertonic conditions implies that in a physiological setting, PfAQP mainly acts as a water/glycerol channel rather than a urea facilitator. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Effect of sugar alcohol sorbitol on in vitro shoot development of Dianthus serotinus Waldst. et Kit.

    Directory of Open Access Journals (Sweden)

    Marković Marija

    2014-01-01

    Full Text Available The aim of this study was to investigate the effect of different concentrations of sorbitol on the development of the in vitro culture of D. serotinus in the multiplication phase. The obtained results showed that sorbitol generally had a positive effect, depending on its concentration and explant type. In addition, the presence of sorbitol affected the change of pH value of the media after autoclaving and after 25 days of in vitro culture, which could affect the availability of certain ions to plants. Therefore, the obtained results indicate that sorbitol can be used as an energy source for the in vitro culture of D. serotinus, but this should be further investigated. [Projekat Ministarstva nauke Republike Srbije, br. 43007

  13. Effect of sorbitol in callus induction and plant regeneration in wheat

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-01

    Dec 1, 2009 ... Key words: Callus induction, plant regeneration, wheat, 2,4-D, sorbitol. INTRODUCTION ... regeneration is better on hormone-free medium or that .... AB (interaction). 15 ... element and creates osmotic stress as reported by.

  14. Reagentless D-sorbitol biosensor based on D-sorbitol dehydrogenase immobilized in a sol-gel carbon nanotubes-poly(methylene green) composite.

    Science.gov (United States)

    Wang, Zhijie; Etienne, Mathieu; Urbanova, Veronika; Kohring, Gert-Wieland; Walcarius, Alain

    2013-04-01

    A reagentless D-sorbitol biosensor based on NAD-dependent D-sorbitol dehydrogenase (DSDH) immobilized in a sol-gel carbon nanotubes-poly(methylene green) composite has been developed. It was prepared by durably immobilizing the NAD(+) cofactor with DSDH in a sol-gel thin film on the surface of carbon nanotubes functionalized with poly(methylene green). This device enables selective determination of D-sorbitol at 0.2 V with a sensitivity of 8.7 μA mmol(-1) L cm(-2) and a detection limit of 0.11 mmol L(-1). Moreover, this biosensor has excellent operational stability upon continuous use in hydrodynamic conditions.

  15. Thin layer chromatography of glucose and sorbitol on Cu(II)-impregnated silica gel plates

    Energy Technology Data Exchange (ETDEWEB)

    Hadzija, O. (Ruder Boskovic Inst., Zagreb (Croatia)); Spoljar, B. (Ruder Boskovic Inst., Zagreb (Croatia)); Sesartic, L. (Inst. of Immunology, Zagreb (Croatia))

    1994-04-01

    A thin-layer chromatographic (TLC) separation of glucose and sorbitol on CU(II)-impregnated silica gel plates with n-propanol: Water (4:1) v/v as developer and potassium permanganate as detecting reagent has been worked out. The new impregnant is completely insoluble in water and thus enables the use of an aqueous developer. The R[sub f]-values are 55 and 10 for glucose and sorbitol, respectively. (orig.)

  16. Improved cryopreservability of stallion sperm using a sorbitol-based freezing extender.

    Science.gov (United States)

    Pojprasath, T; Lohachit, C; Techakumphu, M; Stout, T; Tharasanit, T

    2011-06-01

    Cryopreservation of stallion semen is often associated with poor post-thaw sperm quality. Sugars are among the important components of a freezing extender and act as non-permeating cryoprotectants. This study aimed to compare the quality of stallion sperm frozen with glucose, fructose or sorbitol-containing freezing extenders. Semen was collected from six stallions of proven fertility and cryopreserved using a freezing extender containing different types of monosaccharide sugars (glucose, fructose or sorbitol). After thawing, the semen was examined for sperm motility, viability, acrosome integrity, plasma membrane functionality and sperm longevity. The fertility of semen frozen in the presence of sorbitol was also tested by artificial insemination. Sperm quality was significantly decreased following freezing and thawing (P sorbitol and glucose (P sorbitol-based extender when examined at 2 and 4 h post-thaw, all of these parameters plus plasma membrane functionality were improved for sperm frozen in the sorbitol extender than in the glucose extender when examined 10 min post-thaw. Two of four mares (50%) inseminated with semen frozen with a sorbitol-containing freezing extender became pregnant. It is concluded that different sugars have different abilities to protect against cryoinjury during freezing and thawing of stallion sperm. This study demonstrated that an extender containing sorbitol as primary sugar can be used to successfully cryopreserve equine sperm; moreover, the quality of frozen-thawed sperm appeared to be better than when glucose or fructose was the principle sugar in the freezing extender. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Translocation of sorbitol and other photosynthates in golden delicious apple shoots

    International Nuclear Information System (INIS)

    Steenkamp, J.; Terblanche, J.H.; De Villiers, O.T.

    1982-01-01

    This study was undertaken to determine to what extent sorbitol and other photosynthates are translocated in Golden Delicious apple shoots. The distribution of radioactivity in the different fractions, after the leaves had been exposed to radiocarbon, was found in segment of the shoots directly below the treatment leaves. The highest 14 C activity was in the carbohydrate fraction. The results indicate that sorbitol is the principal carbohydrate transported in Golden Delicious apple shoots

  18. Sorbitol treatment extends lifespan and induces the osmotic stress response in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Devon eChandler-Brown

    2015-10-01

    Full Text Available The response to osmotic stress is a highly conserved process for adapting to changing environmental conditions. Prior studies have shown that hyperosmolarity by addition of sorbitol to the growth medium is sufficient to increase both chronological and replicative lifespan in the budding yeast, Saccharomyces cerevisiae. Here we report a similar phenomenon in the nematode Caenorhabditis elegans. Addition of sorbitol to the nematode growth medium induces an adaptive osmotic response and increases C. elegans lifespan by about 35%. Lifespan extension from 5% sorbitol behaves similarly to dietary restriction in a variety of genetic backgrounds, increasing lifespan additively with mutation of daf-2(e1370 and independently of daf-16(mu86, sir-2.1(ok434, aak-2(ok524, and hif-1(ia04. Dietary restriction by bacterial deprivation or mutation of eat-2(ad1113 fails to further extend lifespan in the presence of 5% sorbitol. Two mutants with constitutive activation of the osmotic response, osm-5(p813 and osm-7(n1515, were found to be long-lived, and lifespan extension from sorbitol required the glycerol biosynthetic enzymes GPDH-1 and GPDH-2. Taken together, these observations demonstrate that exposure to sorbitol at levels sufficient to induce an adaptive osmotic response extends lifespan in worms and define the osmotic stress response pathway as a longevity pathway conserved between yeast and nematodes.

  19. Comparison of the effect of sorbitol and glucose on calcium absorption in postmenopausal women

    International Nuclear Information System (INIS)

    Francis, R.M.; Peacock, M.; Barkworth, S.A.; Marshall, D.H.

    1986-01-01

    It has been suggested that the oral administration of sorbitol promotes calcium absorption, while glucose has no effect. We have therefore compared the effect of oral sorbitol and glucose on the absorption of radiocalcium from low and high carrier loads in healthy postmenopausal women. In a control group of 20 women given neither sorbitol nor glucose, the mean +/- SEM fractional radiocalcium absorption rate from a low carrier load was 0.65 +/- 0.05 (fraction of dose/h). In a second group of 10 women the fractional absorption rate from the low carrier load was lower (p less than 0.05) with 10 g sorbitol (0.48 +/- 0.05) than with 10 g glucose (0.65 +/- 0.08). Fractional absorption of radiocalcium from a high carrier load measured in a third group of seven women using two isotopes (oral 45Ca, IV 47Ca) was also lower (p less than 0.001) with 10 g sorbitol (0.22 +/- 0.01, fraction/3 h) than with 10 g glucose (0.29 +/- 0.02). The results suggest that calcium absorption from a low carrier load is unaltered by glucose but that absorption of calcium from both low and high carrier loads is lower with sorbitol than with glucose

  20. Effect of Guar Gum with Sorbitol Coating on the Properties and Oil Absorption of French Fries.

    Science.gov (United States)

    Jia, Bo; Fan, Daming; Li, Jinwei; Duan, Zhenhua; Fan, Liuping

    2017-12-13

    This paper investigated the effects of guar gum with sorbitol coating on the oil absorption of French fries by combined dye oil methods, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The results showed that pretreatment of blanching with calcium ions and coating with guar gum and sorbitol could significantly reduce the structural oil (STO) and penetrated surface oil (PSO) of French fries and have no negative effects on its texture and also effectively control the final moisture content ( p French fries with guar gum and sorbitol reduced by 50.8%, 33.1% and 30.6%, respectively. CLSM photographs confirmed that STO significantly reduced after coating with guar gum and sorbitol, followed by PSO. In the process of frying, the coatings of guar gum or guar gum with sorbitol could effectively prevent oil from infiltrating the potato tissue, which can be seen in the SEM photographs. The barrier properties of French fries were enhanced by coating guar gum, and sorbitol was added to avoid pores and cracks. Blanching with calcium ion can significantly reduce the final moisture content of coating French fries.

  1. Peranan sorbitol dalam mempertahankan kestabilan pH saliva pada proses pencegahan karies (The role of sorbitol in maintaining saliva’s pH to prevent caries process

    Directory of Open Access Journals (Sweden)

    Diana Soesilo

    2006-03-01

    Full Text Available People in Indonesia often consume food containing sucrose. If the sucrose consumed is in a large amount, it will decrease saliva’s pH and soon teeth destruction will happen. To avoid it, it is necessary to change sucrose consumption habit into another kind of sugar, namely sorbitol. Sorbitol is preferred to use, because it is cheaper and easier to get. Sorbitol is made from cassava, which is plentifully grown in Indonesia. Sorbitol is not good media for bacteria to grow. Because sorbitol has a diol, so it’s difficult to catalyst by glucosyltransferase enzyme, which is produced by bacteria Streptococcus mutans. The conclusion is that sorbitol is difficult to be fermented by Streptococcus mutans so it will not decrease saliva’s pH.

  2. Look fast: Crystallization of conjugated molecules during solution shearing probed in-situ and in real time by X-ray scattering

    KAUST Repository

    Smilgies, Detlef Matthias; Li, Ruipeng; Giri, Gaurav; Chou, Kang Wei; Diao, Ying; Bao, Zhenan; Amassian, Aram

    2012-01-01

    High-speed solution shearing, in which a drop of dissolved material is spread by a coating knife onto the substrate, has emerged as a versatile, yet simple coating technique to prepare high-mobility organic thin film transistors. Solution shearing and subsequent drying and crystallization of a thin film of conjugated molecules is probed in situ using microbeam grazing incidence wide-angle X-ray scattering (μGIWAXS). We demonstrate the advantages of this approach to study solution based crystal nucleation and growth, and identify casting parameter combinations to cast highly ordered and laterally aligned molecular thin films. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Look fast: Crystallization of conjugated molecules during solution shearing probed in-situ and in real time by X-ray scattering

    KAUST Repository

    Smilgies, Detlef Matthias

    2012-12-20

    High-speed solution shearing, in which a drop of dissolved material is spread by a coating knife onto the substrate, has emerged as a versatile, yet simple coating technique to prepare high-mobility organic thin film transistors. Solution shearing and subsequent drying and crystallization of a thin film of conjugated molecules is probed in situ using microbeam grazing incidence wide-angle X-ray scattering (μGIWAXS). We demonstrate the advantages of this approach to study solution based crystal nucleation and growth, and identify casting parameter combinations to cast highly ordered and laterally aligned molecular thin films. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. A novel method for determining the solubility of small molecules in aqueous media and polymer solvent systems using solution calorimetry.

    Science.gov (United States)

    Fadda, Hala M; Chen, Xin; Aburub, Aktham; Mishra, Dinesh; Pinal, Rodolfo

    2014-07-01

    To explore the application of solution calorimetry for measuring drug solubility in experimentally challenging situations while providing additional information on the physical properties of the solute material. A semi-adiabatic solution calorimeter was used to measure the heat of dissolution of prednisolone and chlorpropamide in aqueous solvents and of griseofulvin and ritonavir in viscous solutions containing polyvinylpyrrolidone and N-ethylpyrrolidone. Dissolution end point was clearly ascertained when heat generation stopped. The heat of solution was a linear function of dissolved mass for all drugs (solution of 9.8 ± 0.8, 28.8 ± 0.6, 45.7 ± 1.6 and 159.8 ± 20.1 J/g were obtained for griseofulvin, ritonavir, prednisolone and chlorpropamide, respectively. Saturation was identifiable by a plateau in the heat signal and the crossing of the two linear segments corresponds to the solubility limit. The solubilities of prednisolone and chlopropamide in water by the calorimetric method were 0.23 and 0.158 mg/mL, respectively, in agreement with the shake-flask/HPLC-UV determined values of 0.212 ± 0.013 and 0.169 ± 0.015 mg/mL, respectively. For the higher solubility and high viscosity systems of griseofulvin and ritonavir in NEP/PVP mixtures, respectively, solubility values of 65 and 594 mg/g, respectively, were obtained. Solution calorimetry offers a reliable method for measuring drug solubility in organic and aqueous solvents. The approach is complementary to the traditional shake-flask method, providing information on the solid properties of the solute. For highly viscous solutions, the calorimetric approach is advantageous.

  5. Efficacy of vinegar, sorbitol and sodium benzoate in mitigation of Salmonella contamination in betel leaf

    Directory of Open Access Journals (Sweden)

    Al Asmaul Husna

    2015-06-01

    Full Text Available The present study was undertaken to mitigate Salmonella from betel leaf in Mymensingh. A total of 35 betel leaf samples were collected from 2 baroujes and 5 local markets in Mymensingh. The samples were sub-divided into two groups: (i phosphate buffer solution (PBS washed, and (ii grinded sample. There was control and treated (with 1.5% vinegar, sorbitol, and sodium benzoate sub-groups in both groups. Mitigation of Salmonella was determined by comparing Total Viable Count (TVC and Total Salmonella Count (TSAC of control with treated groups. No bacterial growth was observed in the betel leaf samples collected directly from barouj level. At market level, when grinded, there was no growth of bacteria in Plate Count Agar (PCA and Salmonella- Shigella (SS or Xylose Lysine De-oxy-chocolate (XLD in both treated and untreated groups. But when the PBS washed samples were used, the TVC (mean log CFU±SD/mL of betel leaf ranged from 5.16±0.82 to 5.96±1.11, whereas the TSAC value ranged from 4.87±0.58 to 5.56±1.00 for untreated group. In vinegar, there was no growth, but when treated with sorbitol, the TVC (mean log CFU±SD/mL value reduced to 5.00±0.54 to 5.66±1.09, and TSAC (mean log CFU±SD/mL value reduced to 4.28±0.71 to 4.78±0.64. When treated with sodium benzoate, the TVC (mean log CFU±SD/mL value reduced to 5.06±0.53 to 5.75±1.02, and TSAC (mean log CFU±SD/mL value reduced to 4.34±0.79 to 4.92±0.64. Data of this study indicates that all the three chemicals were effective in terms of reducing bacterial load but vinegar (1.5% was found to be the most effective against Salmonella as well as some other bacteria when treated for 10 min.

  6. Diffusion of flexible, charged, nanoscopic molecules in solution: Size and pH dependence for PAMAM dendrimer

    Science.gov (United States)

    Maiti, Prabal K.; Bagchi, Biman

    2009-12-01

    In order to understand self-diffusion (D) of a charged, flexible, and porous nanoscopic molecule in water, we carry out very long, fully atomistic molecular dynamics simulation of PAMAM dendrimer up to eight generations in explicit salt water under varying pH. We find that while the radius of gyration (Rg) varies as N1/3, the self-diffusion constant (D ) scales, surprisingly, as N-α, with α =0.39 at high pH and 0.5 at neutral pH, indicating a dramatic breakdown of Stokes-Einstein relation for diffusion of charged nanoscopic molecules. The variation in D as a function of radius of gyration demonstrates the importance of treating water and ions explicitly in the diffusion process of a flexible nanoscopic molecule. In agreement with recent experiments, the self-diffusion constant increases with pH, revealing the importance of dielectric friction in the diffusion process. The shape of a dendrimer is found to fluctuate on a nanosecond time scale. We argue that this flexibility (and also the porosity) of the dendrimer may play an important role in determining the mean square displacement of the dendrimer and the breakdown of the Stokes-Einstein relation between diffusion constant and the radius.

  7. Use of bovine catalase and manganese dioxide for elimination of hydrogen peroxide from partly oxidized aqueous solutions of aromatic molecules - Unexpected complications

    Science.gov (United States)

    Kovács, Krisztina; Sági, Gyuri; Takács, Erzsébet; Wojnárovits, László

    2017-10-01

    Being a toxic substance, hydrogen peroxide (H2O2) formed during application of advanced oxidation processes disturbs the biological assessment of the treated solutions. Therefore, its removal is necessary when the concentration exceeds the critical level relevant to the biological tests. In this study, H2O2 removal was tested using catalase enzyme or MnO2 as catalysts and the concentration changes were measured by the Cu(II)/phenanthroline method. MnO2 and Cu(II) were found to react not only with H2O2 but also with the partly oxidized intermediates formed in the hydroxyl radical induced degradation of aromatic antibiotic and pesticide compounds. Catalase proved to be a milder oxidant, it did not show significant effects on the composition of organic molecules. The Cu(II)/phenanthroline method gives the correct H2O2 concentration only in the absence of easily oxidizable compounds, e.g. certain phenol type molecules.

  8. Tracking problems and possible solutions in the quantitative determination of small molecule drugs and metabolites in biological fluids using liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Bakhtiar, Ray; Majumdar, Tapan K

    2007-01-01

    During the last decade, quantification of low molecular weight molecules using liquid chromatography-tandem mass spectrometry in biological fluids has become a common procedure in many preclinical and clinical laboratories. This overview highlights a number of issues involving "small molecule drugs", bioanalytical liquid chromatography-tandem mass spectrometry, which are frequently encountered during assay development. In addition, possible solutions to these issues are proposed with examples in some of the case studies. Topics such as chromatographic peak shape, carry-over, cross-talk, standard curve non-linearity, internal standard selection, matrix effect, and metabolite interference are presented. Since plasma is one of the most widely adopted biological fluid in drug discovery and development, the focus of this discussion will be limited to plasma analysis. This article is not intended to be a comprehensive overview and readers are encouraged to refer to the citations herein.

  9. An exploratory study; the therapeutic effects of premixed activated charcoal-sorbitol administration in patients poisoned with organophosphate pesticide.

    Science.gov (United States)

    Moon, Jeongmi; Chun, Byeongjo; Song, Kyounghwan

    2015-02-01

    The effects of activated charcoal (AC) mixed with cathartics for gastric decontamination in the management of organophosphate (OP) poisoning remain unknown due to limited clinical evidence. This exploratory study assessed the effectiveness of premixed AC-sorbitol as a treatment for OP poisoning. This retrospective observational case study included patients who either did not receive AC-sorbitol or received a single dose of AC-sorbitol within 24 h after OP ingestion. The patients were divided into three groups: no AC-sorbitol treatment, patients who received AC-sorbitol within 1 h of OP ingestion, and patients who received AC-sorbitol more than 1 h after OP ingestion. Mortality, the development of respiratory failure, and the duration of mechanical ventilation were used as outcome measurements for effectiveness, whereas aspiration pneumonia and electrolyte imbalance were employed as safety measurements. Among 262 patients with OP poisoning, 198 were included. Of these, 133 patients did not receive AC-sorbitol, whereas 14 and 51 patients received AC-sorbitol within 1 h or more than 1 h after ingestion, respectively. The time from ingestion to hospital arrival and time from ingestion to administration of atropine and pralidoxime differed among the groups, whereas other characteristics, including age, amount ingested, and type of ingested OP, were similar among the groups. Univariate and multivariate analysis demonstrated that the administration of AC-sorbitol was not associated with outcome measures for effectiveness and did not significantly increase either aspiration pneumonia or electrolyte imbalances during hospitalization. The administration of AC-sorbitol exerted neither beneficial nor harmful effects on the outcomes of OP-poisoned patients regardless of the time from OP ingestion to administration, compared with those of patients who did not receive AC-sorbitol. However, this study enrolled a small number of patients who received AC-sorbitol; further qualified

  10. Development of hydrogel TentaGel shell-core beads for ultrahigh throughput solution-phase screening of encoded OBOC combinatorial small molecule libraries.

    Science.gov (United States)

    Baek, Hyoung Gee; Liu, Ruiwu; Lam, Kit S

    2009-01-01

    The one-bead one-compound (OBOC) combinatorial library method enables the rapid generation and screening of millions of discrete chemical compounds on beads. Most of the OBOC screening methods require the library compounds to remain tethered to the bead during screening process. Methods have also been developed to release library compounds from immobilized beads for in situ solution phase or "lawn" assays. However, this latter approach, while extremely powerful, is severely limited by the lack of suitable solid supports for such assays. Here, we report on the development of a novel hydrogel TentaGel shell-core (HTSC) bead in which hydrogel is grafted onto the polystyrene-based TentaGel (TG) bead as an outer shell (5-80 mum thick) via free radical surface-initiated polymerization. This novel shell-core bilayer resin enables the preparation of encoded OBOC combinatorial small molecule libraries, such that the library compounds reside on the highly hydrophilic outer layer and the coding tags reside in the polystyrene-based TG core. Using fluorescein as a model small molecule compound, we have demonstrated that fluorescein molecules that have been linked covalently to the hydrogel shell via a disulfide bond could readily diffuse out of the hydrogel layer into the bead surrounding after reduction with dithiothreitol. In contrast, under identical condition, the released fluorescein molecules remained bound to unmodified TG bead. We have prepared an encoded OBOC small molecule library on the novel shell-core beads and demonstrated that the beads can be readily decoded.

  11. Solution-processed small molecule-polymer blend organic thin-film transistors with hole mobility greater than 5 cm 2/Vs

    KAUST Repository

    Smith, Jeremy N.

    2012-04-10

    Using phase-separated organic semiconducting blends containing a small molecule, as the hole transporting material, and a conjugated amorphous polymer, as the binder material, we demonstrate solution-processed organic thin-film transistors with superior performance characteristics that include; hole mobility >5 cm 2/Vs, current on/off ratio ≥10 6 and narrow transistor parameter spread. These exceptional characteristics are attributed to the electronic properties of the binder polymer and the advantageous nanomorphology of the blend film. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Solution-processed small molecule-polymer blend organic thin-film transistors with hole mobility greater than 5 cm 2/Vs

    KAUST Repository

    Smith, Jeremy N.; Zhang, Weimin; Sougrat, Rachid; Zhao, Kui; Li, Ruipeng; Cha, Dong Kyu; Amassian, Aram; Heeney, Martin J.; McCulloch, Iain A.; Anthopoulos, Thomas D.

    2012-01-01

    Using phase-separated organic semiconducting blends containing a small molecule, as the hole transporting material, and a conjugated amorphous polymer, as the binder material, we demonstrate solution-processed organic thin-film transistors with superior performance characteristics that include; hole mobility >5 cm 2/Vs, current on/off ratio ≥10 6 and narrow transistor parameter spread. These exceptional characteristics are attributed to the electronic properties of the binder polymer and the advantageous nanomorphology of the blend film. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Current-voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution.

    Science.gov (United States)

    Briechle, Bernd M; Kim, Youngsang; Ehrenreich, Philipp; Erbe, Artur; Sysoiev, Dmytro; Huhn, Thomas; Groth, Ulrich; Scheer, Elke

    2012-01-01

    We report on an experimental analysis of the charge transport through sulfur-free photochromic molecular junctions. The conductance of individual molecules contacted with gold electrodes and the current-voltage characteristics of these junctions are measured in a mechanically controlled break-junction system at room temperature and in liquid environment. We compare the transport properties of a series of molecules, labeled TSC, MN, and 4Py, with the same switching core but varying side-arms and end-groups designed for providing the mechanical and electrical contact to the gold electrodes. We perform a detailed analysis of the transport properties of TSC in its open and closed states. We find rather broad distributions of conductance values in both states. The analysis, based on the assumption that the current is carried by a single dominating molecular orbital, reveals distinct differences between both states. We discuss the appearance of diode-like behavior for the particular species 4Py that features end-groups, which preferentially couple to the metal electrode by physisorption. We show that the energetic position of the molecular orbital varies as a function of the transmission. Finally, we show for the species MN that the use of two cyano end-groups on each side considerably enhances the coupling strength compared to the typical behavior of a single cyano group.

  14. Current–voltage characteristics of single-molecule diarylethene junctions measured with adjustable gold electrodes in solution

    Directory of Open Access Journals (Sweden)

    Bernd M. Briechle

    2012-11-01

    Full Text Available We report on an experimental analysis of the charge transport through sulfur-free photochromic molecular junctions. The conductance of individual molecules contacted with gold electrodes and the current–voltage characteristics of these junctions are measured in a mechanically controlled break-junction system at room temperature and in liquid environment. We compare the transport properties of a series of molecules, labeled TSC, MN, and 4Py, with the same switching core but varying side-arms and end-groups designed for providing the mechanical and electrical contact to the gold electrodes. We perform a detailed analysis of the transport properties of TSC in its open and closed states. We find rather broad distributions of conductance values in both states. The analysis, based on the assumption that the current is carried by a single dominating molecular orbital, reveals distinct differences between both states. We discuss the appearance of diode-like behavior for the particular species 4Py that features end-groups, which preferentially couple to the metal electrode by physisorption. We show that the energetic position of the molecular orbital varies as a function of the transmission. Finally, we show for the species MN that the use of two cyano end-groups on each side considerably enhances the coupling strength compared to the typical behavior of a single cyano group.

  15. The Importance of End Groups for Solution-Processed Small-Molecule Bulk-Heterojunction Photovoltaic Cells.

    Science.gov (United States)

    Duan, Ruomeng; Cui, Yong; Zhao, Yanfei; Li, Chen; Chen, Long; Hou, Jianhui; Wagner, Manfred; Baumgarten, Martin; He, Chang; Müllen, Klaus

    2016-05-10

    End groups in small-molecule photovoltaic materials are important owing to their strong influence on molecular stability, solubility, energy levels, and aggregation behaviors. In this work, a series of donor-acceptor pentads (D2 -A-D1 -A-D2 ) were designed and synthesized, aiming to investigate the effect of the end groups on the materials properties and photovoltaic device performance. These molecules share identical central A-D1 -A triads (with benzodithiophene as D1 and 6-carbonyl-thieno[3,4-b]thiophene as A), but with various D2 end groups composed of alkyl-substituted thiophene (T), thieno[3,2-b]thiophene (TT), and 2,2'-bithiophene (BT). The results indicate a relationship between conjugated segment/alkyl chain length of the end groups and the photovoltaic performance, which contributes to the evolving molecular design principles for high efficiency organic solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Increased sorbitol levels in the hypertrophic ligamentum flavum of diabetic patients with lumbar spinal canal stenosis.

    Science.gov (United States)

    Luo, Jiaquan; Huang, Lu; Chen, Zhuo; Zeng, Zhaoxun; Miyamoto, Takeshi; Wu, Hao; Zhang, Zhongzu; Pan, Zhimin; Fujita, Nobuyuki; Hikata, Tomohiro; Iwanami, Akio; Tsuji, Takashi; Ishii, Ken; Nakamura, Masaya; Matsumoto, Morio; Watanabe, Kota; Cao, Kai

    2017-05-01

    The pathomechanism of the ligamentum flavum (LF) hypertrophy in diabetic patients with lumbar spinal canal stenosis (LSCS) remains unclear. A cross-sectional study was undertaken to investigate the mechanism of LF hypertrophy in these patients. Twenty-four diabetic and 20 normoglycemic patients with LSCS were enrolled in the study. The structure of the LF in the study subjects was evaluated using histological and immunohistochemical methods, and the levels of sorbitol, pro-inflammatory cytokines, and the fibrogenic factor, TGF-β1, in the LF were analyzed. In vitro experiments were performed using NIH3T3 fibroblasts to evaluate the effect of high-glucose conditions and an aldose reductase inhibitor on the cellular production of sorbitol, pro-inflammatory factors, and TGF-β1. We found that the LF of diabetic patients exhibited significantly higher levels of sorbitol and pro-inflammatory cytokines, TGF-β1 and of CD68-positive staining than that of the normoglycemic subjects. The diabetic LF was significantly thicker than that of the controls, and showed evidence of degeneration. The high glucose-cultured fibroblasts exhibited significantly higher levels of sorbitol, pro-inflammatory factors, and TGF-β1 compared to the low glucose-cultured cells, and these levels were dose-dependently reduced by treatment with the aldose reductase inhibitor. Taken together, our data suggests that increased sorbitol levels in the LF of diabetic patients results in increased production of pro-inflammatory and fibrogenic factor, which contribute to LF hypertrophy, and could increase the susceptibility of diabetic patients to LSCS. Furthermore, aldose reductase inhibition effectively reduced the levels of sorbitol and sorbitol-induced pro-inflammatory factor expression in high glucose-cultured fibroblasts. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1058-1066, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  17. Synthesis of sorbitol by Zymomonas mobilis under high osmotic pressure Síntese de sorbitol por Zymomonas mobilis sob elevada pressão osmótica

    Directory of Open Access Journals (Sweden)

    Márcio de Barros

    2006-09-01

    Full Text Available The bacterium Zymomonas mobilis presents potential for sorbitol production when grown in culture medium with high sugar concentration. Sorbitol is produced and accumulated in the periplasma of the bacterium to protect the cells from the harmful effects of high osmotic pressure that results from the action of invertase on sucrose. The conversion of sucrose into glucose and fructose increases the osmolarity of the medium. However, an excessive increase in the osmotic pressure may decrease the sorbitol production. In this work Saccharomyces cerevisiae invertase was added two media containing sucrose 200 and 300 g.L-1. Sorbitol production in sucrose at 200 g.L-1 was 42.35 and 38.42 g.L-1, with and without the invertase treatment, respectively. In the culture medium with 300 g.L-1 sucrose, production reached 60.4 g.L-1 and with invertase treatment was 19.14 g.L-1. These results indicated that the excessive rise in osmotic pressure led to a significant decrease in sorbitol production by the Zymomonas mobilis bacterium in the sucrose medium treated with invertase.A bactéria Zymomonas mobilis, apresenta potencial para produção de sorbitol quando crescida em meio com alta concentração de açúcar. O sorbitol produzido é acumulado no periplasma da bactéria para conter os efeitos prejudiciais da elevada pressão osmótica, que resulta pela ação da enzima invertase, que promove hidrólise da sacarose. A conversão da sacarose em glicose e frutose aumentando a osmolaridade do meio. Entretanto, um aumento excessivo na pressão osmótica pode inibir a produção de sorbitol pela bactéria. Este trabalho empregou invertase de Saccharomyces cerevisiae nos meios de fermentação com sacarose a 200 e 300 g.L-1. A produção de sorbitol no meio com sacarose a 200 g.L-1 foi de 42,35 g.L-1 e 38,42 g.L-1 com e sem tratamento com invertase respectivamente. No meio com 300 g.L-1 sem tratamento, a produção foi de 60,42 e com tratamento 19,14 g.L-1. Estes

  18. Corrosion resistance and durability of superhydrophobic surface formed on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution.

    Science.gov (United States)

    Ishizaki, Takahiro; Masuda, Yoshitake; Sakamoto, Michiru

    2011-04-19

    The corrosion resistant performance and durability of the superhydrophobic surface on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution were investigated using electrochemical and contact angle measurements. The durability of the superhydrophobic surface in corrosive 5 wt% NaCl aqueous solution was elucidated. The corrosion resistant performance of the superhydrophobic surface formed on magnesium alloy was estimated by electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements and appropriate equivalent circuit models revealed that the superhydrophobic surface considerably improved the corrosion resistant performance of magnesium alloy AZ31. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test was performed to investigate the adhesion of the superhydrophobic film to the magnesium alloy surface. The corrosion formation mechanism of the superhydrophobic surface formed on the magnesium alloy was also proposed. © 2011 American Chemical Society

  19. Reliable structural interpretation of small-angle scattering data from bio-molecules in solution - the importance of quality control and a standard reporting framework

    Directory of Open Access Journals (Sweden)

    Jacques David A

    2012-05-01

    Full Text Available Abstract Small-angle scattering is becoming an increasingly popular tool for the study of bio-molecular structures in solution. The large number of publications with 3D-structural models generated from small-angle solution scattering data has led to a growing consensus for the need to establish a standard reporting framework for their publication. The International Union of Crystallography recently established a set of guidelines for the necessary information required for the publication of such structural models. Here we describe the rationale for these guidelines and the importance of standardising the way in which small-angle scattering data from bio-molecules and associated structural interpretations are reported.

  20. Reaction analogues in the radiation-induced deamination and dephosphorylation of bio-organic molecules 2: Oxygenated solutions

    International Nuclear Information System (INIS)

    Garrison, W.M.

    1988-02-01

    The OH-induced deamination and dephosphorylation of simple peptides and phosphate esters in oxygenated solutions involve the fomation and subsequent degradation of the perodyl radicals RCONHC(/dot O/)R 2 and /bigcirc P/ OC(/dot O/ 2 )R 2 respectively. Reaction analogues in the degradation of peroxyl and alkoxyl radicals in these two systems are evaluated with reference to the OH-induced main-chain cleavage of protein and DNA. 25 refs

  1. Molar mass, radius of gyration and second virial coefficient from new static light scattering equations for dilute solutions: application to 21 (macro)molecules.

    Science.gov (United States)

    Illien, Bertrand; Ying, Ruifeng

    2009-05-11

    New static light scattering (SLS) equations for dilute binary solutions are derived. Contrarily to the usual SLS equations [Carr-Zimm (CZ)], the new equations have no need for the experimental absolute Rayleigh ratio of a reference liquid and solely rely on the ratio of scattered intensities of solutions and solvent. The new equations, which are based on polarizability equations, take into account the usual refractive index increment partial differential n/partial differential rho(2) complemented by the solvent specific polarizability and a term proportional to the slope of the solution density rho versus the solute mass concentration rho(2) (density increment). Then all the equations are applied to 21 (macro)molecules with a wide range of molar mass (0.2equations clearly achieve a better agreement with supplier M values. For macromolecules (M>500 kg mol(-1)), for which the scattered intensity is no longer independent of the scattering angle, the new equations give the same value of the radius of gyration as the CZ equation and consistent values of the second virial coefficient.

  2. Molecular evidence of sorbitol dehydrogenase in tomato, a non-Rosaceae plant.

    Science.gov (United States)

    Ohta, Kazuhiro; Moriguchi, Ryo; Kanahama, Koki; Yamaki, Shohei; Kanayama, Yoshinori

    2005-12-01

    The enzyme NAD-dependent sorbitol dehydrogenase (SDH) is well characterized in the Rosaceae family of fruit trees, which synthesizes sorbitol as a translocatable photosynthate. Expressed sequence tags of SDH-like sequences have also been generated from various non-Rosaceae species that do not synthesize sorbitol as a primary photosynthetic product, but the physiological roles of the encoded proteins in non-Rosaceae plants are unknown. Therefore, we isolated an SDH-like cDNA (SDL) from tomato (Lycopersicon esculentum Mill.). Genomic Southern blot analysis suggested that SDL exists in the tomato genome as a single-copy gene. Northern blot analysis showed that SDL is ubiquitously expressed in tomato plants. Recombinant SDL protein was produced and purified for enzymatic characterization. SDL catalyzed the interconversion of sorbitol and fructose with NAD (H). SDL showed highest activity for sorbitol among the several substrates tested. SDL showed no activity with NADP+. Thus, SDL was identified as a SDH, although the Km values and substrate specificity of SDL were significantly different from those of SDH purified from the Japanese pear (Pyrus pyrifolia), a Rosaceae fruit tree. In addition, tomato was transformed with antisense SDL to evaluate the contribution of SDL to SDH activity in tomato. The transformation decreased SDH activity to approximately 50% on average. Taken together, these results provide molecular evidence of SDH in tomato, and SDL was renamed LeSDH.

  3. Effect of seasonal and geographical differences on skin and effect of treatment with an osmoprotectant: Sorbitol.

    Science.gov (United States)

    Muizzuddin, Neelam; Ingrassia, Michael; Marenus, Kenneth D; Maes, Daniel H; Mammone, Thomas

    2013-01-01

    Human skin maintains an optimal permeability barrier function in a terrestrial environment that varies considerably in humidity. Cells cultured under hyperosmotic stress accumulate osmolytes including sorbitol. Epidermal keratinocytes experience similar high osmolality under dry environmental conditions because of increased transepidermal water loss (TEWL) and concomitant drying of the skin. This study was designed to determine if epidermal keratinocytes, in vitro, could be protected from high osmotic stress, with the exogenous addition of sorbitol. In addition, we evaluated the effect of a formulation containing topical sorbitol on skin barrier and moisturization of subjects living in arid and humid regions in summer as well as in winter. Results from in vitro experiments showed that 50 mM sorbitol protected epidermal keratinocytes from osmotic toxicity induced by sodium chloride. Clinical studies indicated that skin chronically exposed to hot, dry environment appeared to exhibit stronger skin barrier and a lower baseline TEWL. In addition, skin barrier was stronger in summer than in winter. Sorbitol exhibited significant improvement in both barrier repair and moisturization, especially in individuals subjected to arid environmental conditions.

  4. Biosynthesis of sorbitol and other compounds in Golden Delicious apple leaves

    International Nuclear Information System (INIS)

    Steenkamp, J.; Terblanche, J.H.; De Villiers, O.T.

    1981-01-01

    The distribution of radioactivity in the principal alcohol-soluble fractions of Golden Delicious apple leaves after exposure to 14 CO 2 for periods from 5 s to 60 min showed that the main products of photosynthesis were located in the phosphorylated and sugar fractions. Although the phosphorylated fraction consistently contained the highest radioactivity, no attempt was made to separate and identify the different compounds. As the percentage activity in the sugar (and sorbitol) and phosphorylated fractions increased with time, that in the organic acid and amino acid fractions decreased. Since the sugar and sorbitol fraction contained 45% of the total radioactivity after 60 min exposure to 14 CO 2 , and since sorbitol contained 82% of the radioactivity in this fraction, it appears that sorbitol is the principal non-phosphorylated end-product of photosynthesis in Golden Delicious apple leaves. Similar results were obtained with plum and apricot leaves. Since after only 60 s of photosynthesis sorbitol contained the highest radioactivity, it is apparent that the formation of this compound is very rapid, plays a role in the metabolism of Golden Delicious apple leaves, and that it is probably associated with the chloroplasts, as was found for plum leaves. The fact that amino acids and other organic acids also contained an appreciable amount of radioactivity (especially after short periods of photosynthesis) indicates a close relationship between these compounds and the primary products of photosynthesis

  5. Studies of extractant molecules in solution and at liquid-liquid interfaces: structural and mechanistic aspects of synergy effects

    International Nuclear Information System (INIS)

    Baaden, Marc

    2000-01-01

    Molecular dynamics simulations reported herein provide new important insights into cation recognition and complexation in solution as well as liquid-liquid extraction, with a particular focus on the microscopic events taking place at the interface between two immiscible liquids. Preliminary studies concerned the representation of the trivalent rare earth cations La 3+ , Eu 3+ and Yb 3+ in force field simulations, probing structural and energetic features on an experimentally characterized model system based on substituted pyridine dicarboxamide ligands. Complexation of such cations by a novel calixarene derivative was investigated showing unexpected features, such as the position of the cation in the complex. Independent experimental studies published subsequently support these findings. Another part of the work is related to industrial liquid-liquid extraction systems using tri-n-butyl phosphate (TBP) as co-solvent, extractant, surfactant and synergist. We investigate 1) concentration effects simulating up to 60 TBP at a water/chloroform interface, 2) acidity using a neutral and ionic model of HNO 3 and 3) synergistic aspects of mixed TBP/calixarene extraction systems. These simulations provide the first microscopic insights into such issues. We finally addressed the topic of solute transfer across the water/chloroform interface. The potential of mean force for such a process has been calculated by both standard methods and novel approaches [fr

  6. Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Tina Kuo Fung [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25°C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB-, with all complexes containing only one NPB- per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH)4- (aq.), i.e. the complexation constants increase with increasing number of -OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB-) at higher concentrations. The -OH group on the NPB- which is left uncomplexed after one solute molecule had bound to the other two -OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA+ can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB-. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

  7. Long-range correlations, geometrical structure, and transport properties of macromolecular solutions. The equivalence of configurational statistics and geometrodynamics of large molecules.

    Science.gov (United States)

    Mezzasalma, Stefano A

    2007-12-04

    A special theory of Brownian relativity was previously proposed to describe the universal picture arising in ideal polymer solutions. In brief, it redefines a Gaussian macromolecule in a 4-dimensional diffusive spacetime, establishing a (weak) Lorentz-Poincaré invariance between liquid and polymer Einstein's laws for Brownian movement. Here, aimed at inquiring into the effect of correlations, we deepen the extension of the special theory to a general formulation. The previous statistical equivalence, for dynamic trajectories of liquid molecules and static configurations of macromolecules, and rather obvious in uncorrelated systems, is enlarged by a more general principle of equivalence, for configurational statistics and geometrodynamics. Accordingly, the three geodesic motion, continuity, and field equations could be rewritten, and a number of scaling behaviors were recovered in a spacetime endowed with general static isotropic metric (i.e., for equilibrium polymer solutions). We also dealt with universality in the volume fraction and, unexpectedly, found that a hyperscaling relation of the form, (average size) x (diffusivity) x (viscosity)1/2 ~f(N0, phi0) is fulfilled in several regimes, both in the chain monomer number (N) and polymer volume fraction (phi). Entangled macromolecular dynamics was treated as a geodesic light deflection, entaglements acting in close analogy to the field generated by a spherically symmetric mass source, where length fluctuations of the chain primitive path behave as azimuth fluctuations of its shape. Finally, the general transformation rule for translational and diffusive frames gives a coordinate gauge invariance, suggesting a widened Lorentz-Poincaré symmetry for Brownian statistics. We expect this approach to find effective applications to solutions of arbitrarily large molecules displaying a variety of structures, where the effect of geometry is more explicit and significant in itself (e.g., surfactants, lipids, proteins).

  8. X-ray crystal structure and small-angle X-ray scattering of sheep liver sorbitol dehydrogenase

    DEFF Research Database (Denmark)

    Yennawar, Hemant; Møller, Magda; Gillilan, Richard

    2011-01-01

    The X-ray crystal structure of sheep liver sorbitol dehydrogenase (slSDH) has been determined using the crystal structure of human sorbitol dehydrogenase (hSDH) as a molecular-replacement model. slSDH crystallized in space group I222 with one monomer in the asymmetric unit. A conserved tetramer...

  9. Effect of sorbitol and glycerol on the stability of trypsin and difference between their stabilization effects in the various solvents.

    Science.gov (United States)

    Pazhang, Mohammad; Mehrnejad, Faramarz; Pazhang, Yaghub; Falahati, Hanieh; Chaparzadeh, Nader

    2016-01-01

    The effect of glycerol and sorbitol on the stability of porcine pancreas trypsin was investigated in this work. Molecular dynamics simulation and thermostability results showed that trypsin has two flexible regions, and polyols (sorbitol and glycerol) stabilize the enzyme by decreasing the flexibility of these regions. Radial distribution function results exhibited that sorbitol and glycerol were excluded from the first water layer of the enzyme, therefore decrease the flexibility of the regions by preferential exclusion. Also, results showed that the stabilization effect of sorbitol is more than glycerol. This observation could be because of the larger decrease in the fluctuations of trypsin in the presence of sorbitol. We also examined the role of solvent's hydrophobicity in enzyme stabilization by sorbitol and glycerol. To do so, the thermostability of trypsin was evaluated in the presence of solvents with different hydrophobicity (methanol, ethanol, isopropanol and n-propanol) in addition to the polyols. Our results depicted that glycerol is a better stabilizer than sorbitol in the presence of hydrophobic solvents (n-propanol), whereas sorbitol is a better stabilizer than glycerol in the presence of hydrophilic solvents (methanol). © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  10. Modulation of δ-Aminolevulinic Acid Dehydratase Activity by the Sorbitol-Induced Osmotic Stress in Maize Leaf Segments.

    Science.gov (United States)

    Jain, M; Tiwary, S; Gadre, R

    2018-01-01

    Osmotic stress induced with 1 M sorbitol inhibited δ-aminolevulinic acid dehydratase (ALAD) and aminolevulinic acid (ALA) synthesizing activities in etiolated maize leaf segments during greening; the ALAD activity was inhibited to a greater extent than the ALA synthesis. When the leaves were exposed to light, the ALAD activity increased for the first 8 h, followed by a decrease observed at 16 and 24 h in both sorbitol-treated and untreated leaf tissues. The maximum inhibition of the enzyme activity was observed in the leaf segments incubated with sorbitol for 4 to 8 h. Glutamate increased the ALAD activity in the in vitro enzymatic preparations obtained from the sorbitol-treated leaf segments; sorbitol inhibited the ALAD activity in the preparations from both sorbitol-treated and untreated leaves. It was suggested that sorbitol-induced osmotic stress inhibits the enzyme activity by affecting the ALAD induction during greening and regulating the ALAD steady-state level of ALAD in leaf cells. The protective effect of glutamate on ALAD in the preparations from the sorbitol-treated leaves might be due to its stimulatory effect on the enzyme.

  11. Granule fraction inhomogeneity of calcium carbonate/sorbitol in roller compacted granules

    DEFF Research Database (Denmark)

    Bacher, Charlotte; Olsen, P.M.; Bertelsen, P.

    2008-01-01

    The granule fraction inhomogeneity of roller compacted granules was examined on mixtures of three different morphologic forms of calcium carbonate and three particle sizes of sorbitol. The granule fraction inhomogeneity was determined by the distribution of the calcium carbonate in each of the 10...... size fractions between 0 and 2000 µm and by calculating the demixing potential. Significant inhomogeneous occurrence of calcium carbonate in the size fractions was demonstrated, depending mostly on the particles sizes of sorbitol but also on the morphological forms of calcium carbonate......, the ability of the powder to agglomerate in the roller compactor was demonstrated to be related to the ability of the powder to be compacted into a tablet, thus the most compactable calcium carbonate and the smallest sized sorbitol improved the homogeneity by decreasing the demixing potential....

  12. Development of a promoter shutoff system in Aspergillus oryzae using a sorbitol-sensitive promoter.

    Science.gov (United States)

    Oda, Ken; Terado, Shiho; Toyoura, Rieko; Fukuda, Hisashi; Kawauchi, Moriyuki; Iwashita, Kazuhiro

    2016-09-01

    Promoter shutoff is a general method for analyzing essential genes, but in the fungus Aspergillus oryzae, no tightly repressed promoters have been reported. To overcome the current limitations of conditional promoters, we examined sorbitol- and galactose-responsive genes using microarrays to identify regulatable genes with only minor physiological and genetic effects. We identified two sorbitol-induced genes (designated as sorA and sorB), cloned their promoters, and built a regulated egfp and brlA expression system. Growth medium-dependent enhanced green fluorescence protein (EGFP) fluorescence and conidiation were confirmed for egfp and brlA under the control of their respective promoters. We also used this shutoff system to regulate the essential rhoA, which demonstrated the expected growth inhibition under repressed growth conditions. Our new sorbitol promoter shutoff system developed can serve as a valuable new tool for essential gene analyses of filamentous fungi.

  13. Isohexide and Sorbitol-Derived, Enzymatically Synthesized Renewable Polyesters with Enhanced Tg.

    Science.gov (United States)

    Gustini, Liliana; Lavilla, Cristina; de Ilarduya, Antxon Martínez; Muñoz-Guerra, Sebastián; Koning, Cor E

    2016-10-10

    Sugar-based polyesters derived from sorbitol and isohexides were obtained via solvent-free enzymatic catalysis. Pendant hydroxyl groups, coming from the sorbitol units, were present along the polyester backbone, whereas the two isohexides, namely, isomannide and isoidide dimethyl ester monomers, were selected to introduce rigidity into the polyester chains. The feasibility of incorporating isomannide as a diol compared to the isoidide dimethyl ester as acyl-donor via lipase-catalyzed polycondensation was investigated. The presence of bicyclic units resulted in enhanced T g with respect to the parent sorbitol-containing polyester lacking isohexides. The different capability of the two isohexides to boost the thermal properties confirmed the more flexible character provided by the isoidide diester derivative. Solvent-borne coatings were prepared by cross-linking the sugar-based polyester polyols with polyisocyanates. The increased rigidity of the obtained sugar-based polyester polyols led to an enhancement in hardness of the resulting coatings.

  14. Physicochemical, mechanical and thermal properties of chitosan films with and without sorbitol.

    Science.gov (United States)

    Liu, Mei; Zhou, Yibin; Zhang, Yang; Yu, Chen; Cao, Shengnan

    2014-09-01

    The effect of sorbitol on the physicochemical, mechanical and thermal properties of chitosan films with different degrees of deacetylation (DD; i.e., DD85% and DD95%) was investigated. The thickness, moisture content (MC), water solubility (WS) and water-vapor permeability (WVP) of the films were evaluated. Sorbitol addition reduced MC, increased WS and significantly (psorbitol increased the strain and decreased stress for both DD films, but DD95% could sustain higher strain and DD85% could sustain higher stress. Thermogravimetrics analysis and differential scanning calorimetry showed that sorbitol elicited a lower degradation temperature for both films, and that DD95% films exhibited higher thermal stability than DD85% films. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. A physicochemical study of sugar palm (Arenga Pinnata) starch films plasticized by glycerol and sorbitol

    Science.gov (United States)

    Poeloengasih, Crescentiana D.; Pranoto, Yudi; Hayati, Septi Nur; Hernawan, Rosyida, Vita T.; Prasetyo, Dwi J.; Jatmiko, Tri H.; Apriyana, Wuri; Suwanto, Andri

    2016-02-01

    The present work explores the physicochemical characteristics of sugar palm starch film for a potential hard capsule purpose. Sugar palm (Arenga pinnata) starch films were plasticized with glycerol or sorbitol in various concentrations (30% up to 50% w/w starch). Their effects on physicochemical properties of the films were investigated. The results showed that sugar palm starch was successfully developed as the main material of film using casting method. Incorporation of both glycerol or sorbitol affected the properties of films in different ways. It was found that thickness and solubility increased as plasticizer concentration increased, whereas retraction ratio, swelling degree and swelling thickness decreased with the increased plasticizer concentration.

  16. Sorbitol-modified hyaluronic acid reduces oxidative stress, apoptosis and mediators of inflammation and catabolism in human osteoarthritic chondrocytes.

    Science.gov (United States)

    Mongkhon, John-Max; Thach, Maryane; Shi, Qin; Fernandes, Julio C; Fahmi, Hassan; Benderdour, Mohamed

    2014-08-01

    Our study was designed to elucidate the precise molecular mechanisms by which sorbitol-modified hyaluronic acid (HA/sorbitol) exerts beneficial effects in osteoarthritis (OA). Human OA chondrocytes were treated with increasing doses of HA/sorbitol ± anti-CD44 antibody or with sorbitol alone and thereafter with or without interleukin-1beta (IL-1β) or hydrogen peroxide (H2O2). Signal transduction pathways and parameters related to oxidative stress, apoptosis, inflammation, and catabolism were investigated. HA/sorbitol prevented IL-1β-induced oxidative stress, as measured by reactive oxygen species, p47-NADPH oxidase phosphorylation, 4-hydroxynonenal (HNE) production and HNE-metabolizing glutathione-S-transferase A4-4 expression. Moreover, HA/sorbitol stifled IL-1β-induced metalloproteinase-13, nitric oxide (NO) and prostaglandin E2 release as well as inducible NO synthase expression. Study of the apoptosis process revealed that this gel significantly attenuated cell death, caspase-3 activation and DNA fragmentation elicited by exposure to a cytotoxic H2O2 dose. Examination of signaling pathway components disclosed that HA/sorbitol prevented IL-1β-induced p38 mitogen-activated protein kinase and nuclear factor-kappa B activation, but not that of extracellular signal-regulated kinases 1 and 2. Interestingly, the antioxidant as well as the anti-inflammatory and anti-catabolic effects of HA/sorbitol were attributed to sorbitol and HA, respectively. Altogether, our findings support a beneficial effect of HA/sorbitol in OA through the restoration of redox status and reduction of apoptosis, inflammation and catabolism involved in cartilage damage.

  17. Cloning, Expression, and Characterization of Sorbitol Transporters from Developing Sour Cherry Fruit and Leaf Sink Tissues1

    Science.gov (United States)

    Gao, Zhifang; Maurousset, Laurence; Lemoine, Remi; Yoo, Sang-Dong; van Nocker, Steven; Loescher, Wayne

    2003-01-01

    The acyclic polyol sorbitol is a primary photosynthetic product and the principal photosynthetic transport substance in many economically important members of the family Rosaceace (e.g. almond [Prunus dulcis (P. Mill.) D.A. Webber], apple [Malus pumila P. Mill.], cherry [Prunus spp.], peach [Prunus persica L. Batsch], and pear [Pyrus communis]). To understand key steps in long-distance transport and particularly partitioning and accumulation of sorbitol in sink tissues, we have cloned two sorbitol transporter genes (PcSOT1 and PcSOT2) from sour cherry (Prunus cerasus) fruit tissues that accumulate large quantities of sorbitol. Sorbitol uptake activities and other characteristics were measured by heterologous expression of PcSOT1 and PcSOT2 in yeast (Saccharomyces cerevisiae). Both genes encode proton-dependent, sorbitol-specific transporters with similar affinities (Km sorbitol of 0.81 mm for PcSOT1 and 0.64 mm for PcSOT2). Analyses of gene expression of these transporters, however, suggest different roles during leaf and fruit development. PcSOT1 is expressed throughout fruit development, but especially when growth and sorbitol accumulation rates are highest. In leaves, PcSOT1 expression is highest in young, expanding tissues, but substantially less in mature leaves. In contrast, PcSOT2 is mainly expressed only early in fruit development and not in leaves. Compositional analyses suggest that transport mediated by PcSOT1 and PcSOT2 plays a major role in sorbitol and dry matter accumulation in sour cherry fruits. Presence of these transporters and the high fruit sorbitol concentrations suggest that there is an apoplastic step during phloem unloading and accumulation in these sink tissues. Expression of PcSOT1 in young leaves before completion of the transition from sink to source is further evidence for a role in determining sink activity. PMID:12692316

  18. Crystalline self-assembly of organic molecules with metal ions at the air-aqueous solution interface. A grazing incidence X-ray scattering study

    DEFF Research Database (Denmark)

    Weissbuch, I.; Buller, R.; Kjær, K.

    2002-01-01

    The advent of intense X-rays from synchrotron sources made possible to probe, at the molecular level, the structural aspects of self-assemblies generated at interfaces. Here we present the two-dimensional (2-D) packing arrangements of two-, three- and multi-component organo-metallic self......-assemblies formed via interfacial reaction at the air-aqueous solution interface, as determined by grazing incidence X-ray diffraction (GIRD) and X-ray specular reflectivity techniques. GIXD yields structural information on the crystalline part of the Langmuir film, including the ions and counterions lateral order...... of metal ions bound to the polar head groups of amphipilic molecules; use of bolaamphiphiles to generate oriented thin films with metal ions arranged in periodic layers; delineation of differences in the lateral organization of metal ions at interfaces as induced by racemates and enantiomerically pure...

  19. Electronic excitation of molecules in solution calculated using the symmetry-adapted cluster–configuration interaction method in the polarizable continuum model

    International Nuclear Information System (INIS)

    Fukuda, Ryoichi; Ehara, Masahiro

    2015-01-01

    The effects from solvent environment are specific to the electronic states; therefore, a computational scheme for solvent effects consistent with the electronic states is necessary to discuss electronic excitation of molecules in solution. The PCM (polarizable continuum model) SAC (symmetry-adapted cluster) and SAC-CI (configuration interaction) methods are developed for such purposes. The PCM SAC-CI adopts the state-specific (SS) solvation scheme where solvent effects are self-consistently considered for every ground and excited states. For efficient computations of many excited states, we develop a perturbative approximation for the PCM SAC-CI method, which is called corrected linear response (cLR) scheme. Our test calculations show that the cLR PCM SAC-CI is a very good approximation of the SS PCM SAC-CI method for polar and nonpolar solvents

  20. Improvement of the impedance measurement reliability by some new experimental and data treatment procedures applied to the behavior of copper in neutral chloride solutions containing small heterocycle molecules

    International Nuclear Information System (INIS)

    Blajiev, O.L.; Breugelmans, T.; Pintelon, R.; Hubin, A.

    2006-01-01

    The electrochemical behavior of copper in chloride solutions containing 0.001 M concentrations of small five- and six-ring member heterocyclic molecules was investigated by means of impedance spectroscopy. The investigation was performed by a new technique based on a broadband multisine excitation. This method allows for a quantification and separation of the measurement and stohastic nonlinear noises and for an estimation of the bias non-linear contribution. It as well reduces the perturbation brought to studied system by the measurement process itself. The measurement data for some experimental conditions was quantified by fitting into a equivalent circuit corresponding to a physical model both of them developed earlier. In general, the experimental results obtained show that the number of atoms in the heterocyclic ring and the molecular conformation have a significant influence on the electrochemical response of copper in the investigated environments

  1. Investigations of solution-processed charge generation unit with low concentration of small molecule doped in p-type/HAT-CN{sub 6} for tandem OLED

    Energy Technology Data Exchange (ETDEWEB)

    Talik, N.A., E-mail: azrina_talik@hotmail.com [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yeoh, K.H. [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Centre for Photonics and Advanced Materials Research (CPR), Lee Kong Chian Faculty of Engineering and Science, University Tunku Abdul Rahman, 43000 Kajang, Selangor (Malaysia); Ng, C.Y.B. [Low Dimensional Material Research Centre (LDMRC), Physics Dept., Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Tan, C.Y. [Centre of Advanced Manufacturing & Material Processing (AMMP), Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Yap, B.K., E-mail: kbyap@uniten.edu.my [Centre of Microelectronic and Nano Engineering (CeMNE), College of Engineering, Universiti Tenaga Nasional, 43000 Kajang, Selangor (Malaysia)

    2016-01-15

    We investigated the charge generation and injection mechanism in solution processed charge generation unit (CGU) used in our high performance tandem organic light emitting diode (OLED) via capacitance–voltage (C–V) and current density–voltage (J–V) measurements. By doping 2 wt% of small molecule 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) into Poly (N-vinylcarbazole) (PVK) as p-type layer of the CGU, we obtained more than two folds improvement in the tandem device efficiency compared to single device. The performance improvement of the TAPC doped CGU could be attributed to low built-in potential, large vacuum level shift as well as high charge density for efficient charge generation. - Highlights: • Charge-generation and injection mechanism in CGU for tandem OLED is investigated. • Small molecule, TAPC doped in p-type/HAT-CN{sub 6} has been used for tandem OLED. • The improvement attributes to the lower V{sub bi} and larger ΔV{sub L} in doped layer. • Narrower W and high carrier density also contribute to efficiency improvement.

  2. Investigations of solution-processed charge generation unit with low concentration of small molecule doped in p-type/HAT-CN6 for tandem OLED

    International Nuclear Information System (INIS)

    Talik, N.A.; Yeoh, K.H.; Ng, C.Y.B.; Tan, C.Y.; Yap, B.K.

    2016-01-01

    We investigated the charge generation and injection mechanism in solution processed charge generation unit (CGU) used in our high performance tandem organic light emitting diode (OLED) via capacitance–voltage (C–V) and current density–voltage (J–V) measurements. By doping 2 wt% of small molecule 1,1-bis-(4-bis(4-tolyl)-aminophenyl) cyclohexene (TAPC) into Poly (N-vinylcarbazole) (PVK) as p-type layer of the CGU, we obtained more than two folds improvement in the tandem device efficiency compared to single device. The performance improvement of the TAPC doped CGU could be attributed to low built-in potential, large vacuum level shift as well as high charge density for efficient charge generation. - Highlights: • Charge-generation and injection mechanism in CGU for tandem OLED is investigated. • Small molecule, TAPC doped in p-type/HAT-CN 6 has been used for tandem OLED. • The improvement attributes to the lower V bi and larger ΔV L in doped layer. • Narrower W and high carrier density also contribute to efficiency improvement.

  3. Enhancement of Performance and Mechanism Studies of All-Solution Processed Small-Molecule based Solar Cells with an Inverted Structure.

    Science.gov (United States)

    Long, Guankui; Wu, Bo; Yang, Xuan; Kan, Bin; Zhou, Ye-Cheng; Chen, Li-Chuan; Wan, Xiangjian; Zhang, Hao-Li; Sum, Tze Chien; Chen, Yongsheng

    2015-09-30

    Both solution-processed polymers and small molecule based solar cells have achieved PCEs over 9% with the conventional device structure. However, for the practical applications of photovoltaic technology, further enhancement of both device performance and stability are urgently required, particularly for the inverted structure devices, since this architecture will probably be most promising for the possible coming commercialization. In this work, we have fabricated both conventional and inverted structure devices using the same small molecular donor/acceptor materials and compared the performance of both device structures, and found that the inverted structure based device gave significantly improved performance, the highest PCE so far for inverted structure based device using small molecules as the donor. Furthermore, the inverted device shows a remarkable stability with almost no obvious degradation after three months. Systematic device physics and charge generation dynamics studies, including optical simulation, light-intensity-dependent current-voltage experiments, photocurrent density-effective voltage analyses, transient absorption measurements, and electrical simulations, indicate that the significantly enhanced performance using inverted device is ascribed to the increasing of Jsc compared to the conventional device, which in turn is mainly attributed to the increased absorption of photons in the active layers, rather than the reduced nongeminate recombination.

  4. Follow-up of coeliac disease with the novel one-hour 13C-sorbitol breath test versus the H2-sorbitol breath test.

    Science.gov (United States)

    Tveito, Kari; Hetta, Anne Kristine; Askedal, Mia; Brunborg, Cathrine; Sandvik, Leiv; Løberg, Else Marit; Skar, Viggo

    2011-07-01

    We recently developed a (13)C-sorbitol breath test ((13)C-SBT) as an alternative to the H(2)-sorbitol breath test (H(2)-SBT) for coeliac disease. In this study we compared the diagnostic properties of the H(2)-SBT and the (13)C-SBT in follow-up of coeliac disease. Twenty-seven coeliac patients on a gluten-free diet (GFD) performed the breath tests. All had been tested before treatment in the initial study of the (13)C-SBT, in which 39 untreated coeliac patients, 40 patient controls, and 26 healthy volunteers participated. Five gram sorbitol and 100 mg (13)C-sorbitol were dissolved in 250 ml tap water and given orally. H(2), CH(4) and (13)CO(2) were measured in end-expiratory breath samples every 30 min for 4 h. Increased H(2) concentration ≥20 ppm from basal values was used as cut-off for the H(2)-SBT. Sixty minutes values were used as diagnostic index in the (13)C-SBT. (13)CO(2) levels at 60 min increased in 20/26 treated coeliac patients (77%) after GFD, but were significantly lower than in control groups. Out of 20 patients who had a positive H(2)-SBT before GFD, 12 had a negative H(2)-SBT after GFD. Peak H(2) concentrations were not correlated with (13)C-SBT results. The study confirms the sensitivity of a one-hour (13)C-SBT for small intestinal malabsorption. The (13)C-SBT has superior diagnostic properties compared with the H(2)-SBT in follow-up of coeliac disease.

  5. A biopolymer-based carbon nanotube interface integrated with a redox shuttle and a D-sorbitol dehydrogenase for robust monitoring of D-sorbitol

    International Nuclear Information System (INIS)

    Sefcovicova, J.; Filip, J.; Gemeiner, P.; Bucko, M.; Magdolen, P.; Tkac, J.; Tomcik, P.

    2011-01-01

    We describe the preparation and characterization of a glassy carbon electrode modified with a bionanocomposite consisting of a hyaluronic acid, dispersed carbon nanotubes, and electrostatically bound toluidine blue. The electrode was used to detect NADH in the batch and flow-injection mode of operation. The electrode was further modified by immobilizing sorbitol dehydrogenase to result in biosensor for D-sorbitol that displays good operational stability, a sensitivity of 10.6 μA mM -1 cm -2 , a response time of 16 s, and detection limit in the low micromolar range. The biosensor was successfully applied to off-line monitoring of D-sorbitol during its bioconversion into L-sorbose (a precursor in the synthesis of vitamin C) by Gluconobacter oxydans. The sample assay precision is 2.5% (an average RSD) and the throughput is 65 h -1 if operated in the flow-injection mode. The validation of this biosensor against a reference HPLC method resulted in a slope of correlation of 1.021 ± 0.001 (R 2 = 0.99997). (author)

  6. Comparing and correlating solubility parameters governing the self-assembly of molecular gels using 1,3:2,4-dibenzylidene sorbitol as the gelator.

    Science.gov (United States)

    Lan, Yaqi; Corradini, Maria G; Liu, Xia; May, Tim E; Borondics, Ferenc; Weiss, Richard G; Rogers, Michael A

    2014-12-02

    Solvent properties play a central role in mediating the aggregation and self-assembly of molecular gelators and their growth into fibers. Numerous attempts have been made to correlate the solubility parameters of solvents and gelation abilities of molecular gelators, but a comprehensive comparison of the most important parameters has yet to appear. Here, the degree to which partition coefficients (log P), Henry's law constants (HLC), dipole moments, static relative permittivities (ε(r)), solvatochromic E(T)(30) parameters, Kamlet-Taft parameters (β, α, and π), Catalan's solvatochromic parameters (SPP, SB, and SA), Hildebrand solubility parameters (δ(i)), and Hansen solubility parameters (δ(p), δ(d), δ(h)) and the associated Hansen distance (R(ij)) of 62 solvents (covering a wide range of properties) can be correlated with the self-assembly and gelation of 1,3:2,4-dibenzylidene sorbitol (DBS) gelation, a classic molecular gelator, is assessed systematically. The approach presented describes the basis for each of the parameters and how it can be applied. As such, it is an instructional blueprint for how to assess the appropriate type of solvent parameter for use with other molecular gelators as well as with molecules forming other types of self-assembled materials. The results also reveal several important insights into the factors favoring the gelation of solvents by DBS. The ability of a solvent to accept or donate a hydrogen bond is much more important than solvent polarity in determining whether mixtures with DBS become solutions, clear gels, or opaque gels. Thermodynamically derived parameters could not be correlated to the physical properties of the molecular gels unless they were dissected into their individual HSPs. The DBS solvent phases tend to cluster in regions of Hansen space and are highly influenced by the hydrogen-bonding HSP, δ(h). It is also found that the fate of this molecular gelator, unlike that of polymers, is influenced not only by

  7. Advanced glycation end products and sorbitol in blood from differently compensated diabetic dogs.

    Science.gov (United States)

    Comazzi, S; Bertazzolo, W; Bonfanti, U; Spagnolo, V; Sartorelli, P

    2008-06-01

    Canine diabetes mellitus (DM) is a common metabolic disorder with long term complications, most of which are caused by glycosylation of structural proteins, decreases in antioxidant concentrations, altered osmotic balance and hypoxia due to impaired oxygen transport. Previous studies have demonstrated that under hyperglycemic conditions canine erythrocytes undergo swelling, probably due to activation of the polyol pathway. The present work aimed to assess the plasma concentration of advanced glycation end (AGE) products, stable Amadori-products generated by non-enzymatic glycosylation of proteins and the intracellular concentration of sorbitol, produced by the activation of polyol pathway in 34 blood samples from diabetic dogs and in 14 controls. AGE products were significantly higher (pdogs compared with control animals. The sorbitol concentration in erythrocytes was also significantly higher in diabetic dogs and, in particular, in poorly compensated animals and in dogs with ketonuria. In five cases that were analysed before and after clinical improvement, sorbitol concentration was found to correlate with improvement. These results suggest that non-specific glycosylation is increased and that the polyol pathway is activated in diabetic dogs in a manner that is proportionate to the severity of disease. Moreover, the concentration of AGE products and sorbitol may be useful for monitoring the onset of diabetic complications and assessing the most appropriate therapeutic approaches for management of canine DM.

  8. Carbon-coated ceramic membrane reactor for production of hydrogen via aqueous phase reforming of sorbitol

    NARCIS (Netherlands)

    Neira d'Angelo, M.F.; Ordomskiy, V.; Schouten, J.C.; Schaaf, van der J.; Nijhuis, T.A.

    2014-01-01

    Hydrogen was produced by aqueous-phase reforming (APR) of sorbitol in a carbon-on-alumina tubular membrane reactor (4 nm pore size, 7 cm long, 3 mm internal diameter) that allows the hydrogen gas to permeate to the shell side, whereas the liquid remains in the tube side. The hydrophobic nature of

  9. Simultaneous hydrolysis and hydrogenation of cellobiose to sorbitol in molten salt hydrate media

    NARCIS (Netherlands)

    Li, J.; Soares, H.S.M.P.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The hydrolysis and hydrogenation of cellobiose (4-O-b-D-glucopyranosyl-D-glucose) in ZnCl2_4H2O solvent was studied to optimize the conditions for conversion of lignocellulose (the most abundant renewable resource) into sorbitol (D-glucitol). Water at neutral pH does not allow hydrolysis of

  10. Ordered Mesoporous NiCeAl Containing Catalysts for Hydrogenolysis of Sorbitol to Glycols

    Science.gov (United States)

    Zhou, Zhiwei; Zhang, Jiaqi; Qin, Juan; Li, Dong; Wu, Wenliang

    2018-03-01

    Cellulose-derived sorbitol is emerging as a feasible and renewable feedstock for the production of value-added chemicals. Highly active and stable catalyst is essential for sorbitol hydrogenolysis. Ordered mesoporous M- xNi yCeAl catalysts with different loadings of nickel and cerium species were successfully synthesized via one-pot evaporation-induced self-assembly strategy (EISA) and their catalytic performance were tested in the hydrogenolysis of sorbitol. The physical chemical properties for the catalysts were characterized by XRD, N2 physisorption, H2-TPR, H2 impulse chemisorption, ICP and TEM techniques. The results showed that the ordered mesopores with uniform pore sizes can be obtained and the Ni nanoparticles around 6 nm in size were homogeneously dispersed in the mesopore channels. A little amount of cerium species introduced would be beneficial to their textural properties resulting in higher Ni dispersion, metal area and smaller size of Ni nanoparticles. The M-10Ni2CeAl catalyst with Ni and Ce loading of 10.9 and 6.3 wt % shows better catalytic performance than other catalysts, and the yield of 1,2-PG and EG can reach 56.9% at 493 K and 6 MPa pressure for 8 h after repeating reactions for 12 times without obvious deterioration of physical and chemical properties. Ordered mesoporous M-NiCeAl catalysts are active and stable in sorbitol hydrogenolysis.

  11. Management of constipation in residents with dementia: sorbitol effectiveness and cost.

    Science.gov (United States)

    Volicer, Ladislav; Lane, Patricia; Panke, JoAnn; Lyman, Paul

    2004-01-01

    The objective of this report is to describe a cost-effective strategy for management of constipation in nursing home residents with dementia. We conducted a prospective observational quality improvement study of 41 residents with chronic constipation and receiving an osmotic laxative. Sorbitol was substituted for lactulose. The study was conducted at a dementia special care unit at a Veterans Administration hospital. We measured the number and amount of laxative use over a period of 4 weeks that were required to maintain regular bowel function. There was no difference in efficacy of lactulose and sorbitol. Use of additional laxatives was infrequent: Milk of Magnesia on approximately 10% of days/patient, bisacodyl suppository on 2% to 4% of days/patient, and Fleet enema only on 3 occasions. The cost of constipation management using routine administration of sorbitol and as-needed use of other laxatives was 27% to 55% lower than the cost of other constipation management strategies reported in the literature. Substitution of sorbitol for lactulose does not change efficacy of the treatment and decreases cost. Regular use of an osmotic laxative avoids the costs and discomforts of rectal laxatives.

  12. The relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation using Zymomonas mobilis 2716

    Energy Technology Data Exchange (ETDEWEB)

    Doelle, M.B.; Doelle, H.W. (Queensland Univ., St. Lucia (Australia). Dept. of Microbiology); Greenfield, P.F. (Queensland Univ., St. Lucia (Australia). Dept. of Chemical Engineering)

    1990-11-01

    Investigations into the relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation by Zymomonas mobilis 2716 revealed two distinct phenomena responsible for carbon flow diversion, a 'sucrose effect' and a 'salt effect'. Neither of the two phenomena affects sucrose hydrolysis, but they divert carbon flow of the fructose monomer leading to its own accumulation, sorbitol or oligosaccharide formation. Sucrose concentrations in excess of 15% (w/v) led to sorbitol formation, the level of which may exceed 2% (w/v) depending upon glucose accumulation during sucrose hydrolysis. Increasing mineral ion concentrations led initially to carbon losses and finally to fructose accumulation instead of sorbitol formation. This carbon loss can be corrected by the addition of invertase, which in turn leads to an increase in sorbitol, fructose and ethanol. Potassium and chloride are the dominant ions responsible for suppression of sorbitol formation and fructose uptake, encouraging oligosaccharide formation. These fructooligosaccharides must be of a type which can be converted to fructose, sorbitol and ethanol through the action of invertase. The requirement of invertase addition to prevent fructooligosaccharide formation is indirect evidence that Z. mobilis 2716 does not produce invertase. (orig.).

  13. A quantitative study of methanol/sorbitol co-feeding process of a Pichia pastoris Mut⁺/pAOX1-lacZ strain.

    Science.gov (United States)

    Niu, Hongxing; Jost, Laurent; Pirlot, Nathalie; Sassi, Hosni; Daukandt, Marc; Rodriguez, Christian; Fickers, Patrick

    2013-04-08

    One of the main challenges for heterologous protein production by the methylotrophic yeast Pichia pastoris at large-scale is related to its high oxygen demand. A promising solution is a co-feeding strategy based on a methanol/sorbitol mixture during the induction phase. Nonetheless, a deep understanding of the cellular physiology and the regulation of the AOX1 promoter, used to govern heterologous protein production, during this co-feeding strategy is still scarce. Transient continuous cultures with a dilution rate of 0.023 h(-1) at 25°C were performed to quantitatively assess the benefits of a methanol/sorbitol co-feeding process with a Mut+ strain in which the pAOX1-lacZ construct served as a reporter gene. Cell growth and metabolism, including O2 consumption together with CO2 and heat production were analyzed with regard to a linear change of methanol fraction in the mixed feeding media. In addition, the regulation of the promoter AOX1 was investigated by means of β-galactosidase measurements. Our results demonstrated that the cell-specific oxygen consumption (qO2) could be reduced by decreasing the methanol fraction in the feeding media. More interestingly, maximal β-galactosidase cell-specific activity (>7500 Miller unit) and thus, optimal pAOX1 induction, was achieved and maintained in the range of 0.45 ~ 0.75 C-mol/C-mol of methanol fraction. In addition, the qO2 was reduced by 30% at most in those conditions. Based on a simplified metabolic network, metabolic flux analysis (MFA) was performed to quantify intracellular metabolic flux distributions during the transient continuous cultures, which further shed light on the advantages of methanol/sorbitol co-feeding process. Finally, our observations were further validated in fed-batch cultures. This study brings quantitative insight into the co-feeding process, which provides valuable data for the control of methanol/sorbitol co-feeding, aiming at enhancing biomass and heterologous protein productivities

  14. A quantitative study of methanol/sorbitol co-feeding process of a Pichia pastoris Mut+/pAOX1-lacZ strain

    Science.gov (United States)

    2013-01-01

    Background One of the main challenges for heterologous protein production by the methylotrophic yeast Pichia pastoris at large-scale is related to its high oxygen demand. A promising solution is a co-feeding strategy based on a methanol/sorbitol mixture during the induction phase. Nonetheless, a deep understanding of the cellular physiology and the regulation of the AOX1 promoter, used to govern heterologous protein production, during this co-feeding strategy is still scarce. Results Transient continuous cultures with a dilution rate of 0.023 h-1 at 25°C were performed to quantitatively assess the benefits of a methanol/sorbitol co-feeding process with a Mut+ strain in which the pAOX1-lacZ construct served as a reporter gene. Cell growth and metabolism, including O2 consumption together with CO2 and heat production were analyzed with regard to a linear change of methanol fraction in the mixed feeding media. In addition, the regulation of the promoter AOX1 was investigated by means of β-galactosidase measurements. Our results demonstrated that the cell-specific oxygen consumption (qO2) could be reduced by decreasing the methanol fraction in the feeding media. More interestingly, maximal β-galactosidase cell-specific activity (>7500 Miller unit) and thus, optimal pAOX1 induction, was achieved and maintained in the range of 0.45 ~ 0.75 C-mol/C-mol of methanol fraction. In addition, the qO2 was reduced by 30% at most in those conditions. Based on a simplified metabolic network, metabolic flux analysis (MFA) was performed to quantify intracellular metabolic flux distributions during the transient continuous cultures, which further shed light on the advantages of methanol/sorbitol co-feeding process. Finally, our observations were further validated in fed-batch cultures. Conclusion This study brings quantitative insight into the co-feeding process, which provides valuable data for the control of methanol/sorbitol co-feeding, aiming at enhancing biomass and

  15. Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate. [1,2-propanediol

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Tina Kuo Fung.

    1992-05-01

    The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25{degree}C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB{sup {minus}}, with all complexes containing only one NPB{sup {minus}} per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH){sub 4}{sup {minus}} (aq.), i.e. the complexation constants increase with increasing number of {minus}OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB{sup {minus}}) at higher concentrations. The {minus}OH group on the NPB{sup {minus}} which is left uncomplexed after one solute molecule had bound to the other two {minus}OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA{sup +} can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB{sup {minus}}. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.

  16. Effect of Secondary Doping Using Sorbitol on Structure and Transport Properties of PEDOT-PSS Thin Films

    Science.gov (United States)

    Khasim, Syed; Pasha, Apsar; Roy, Aashish S.; Parveen, Ameena; Badi, Nacer

    2017-07-01

    Poly(3,4-ethylene dioxythiophene):poly(styrenesulphonate) (PEDOT-PSS) in the recent past has emerged as one of the most fascinating conducting polymers for many device applications. The unique feature of PEDOT-PSS is its transparency in the entire visible spectrum with excellent thermal stability. The PEDOT-PSS as prepared as an aqueous dispersion has very low conductivity, and it hinders the performance of a device. In this work we report the conductivity enhancement of PEDOT-PSS thin films through secondary doping using a polar organic solvent such as sorbitol. The mechanism of conductivity enhancement was studied through various physical and chemical characterizations. The effect of sorbitol concentration on structure and transport properties of PEDOT-PSS thin films was investigated in detail. The structural and morphological modifications in PEDOT-PSS due to the addition of sorbitol was studied through Fourier transform spectroscopy, Ultra Violet-visible spectroscopy, theromogravimetric analysis, scanning electron microscopy and atomic force microscopy. The interactions resulting from conformational changes of PEDOT chains that changes from coiled to linear structure due to the sorbitol treatment significantly improves the conductivity of PEDOT-PSS films. The secondary doping of sorbitol reduces the energy barrier that facilitates the charge carrier hopping leading to enhanced conductivity. We have observed that the conductivity of PEDOT-PSS thin films was increased by two fold due to sorbitol treatment when compared to conductivity of pure PEDOT-PSS. We have carried out detailed analysis of dielectric parameters of sorbitol-treated PEDOT-PSS films and found that sorbitol treatment has a significant effect on various dielectric attributes of PEDOT-PSS films. Hence, secondary doping using sorbitol could be a useful way to effectively tailor the conductivity and dielectric properties of PEDOT-PSS thin films that can be used as flexible electrodes in

  17. Elucidating the weak protein-protein interaction mechanisms behind the liquid-liquid phase separation of a mAb solution by different types of additives.

    Science.gov (United States)

    Wu, Guoliang; Wang, Shujing; Tian, Zhou; Zhang, Ning; Sheng, Han; Dai, Weiguo; Qian, Feng

    2017-11-01

    Liquid-liquid phase separation (LLPS) has long been observed during the physical stability investigation of therapeutic protein formulations. The buffer conditions and the presence of various excipients are thought to play important roles in the formulation development of monoclonal antibodies (mAbs). In this study, the effects of several small-molecule excipients (histidine, alanine, glycine, sodium phosphate, sodium chloride, sorbitol and sucrose) with diverse physical-chemical properties on LLPS of a model IgG1 (JM2) solutions were investigated by multiple techniques, including UV-vis spectroscopy, circular dichroism, differential scanning calorimetry/fluorimetry, size exclusion chromatography and dynamic light scattering. The LLPS of JM2 was confirmed to be a thermodynamic equilibrium process with no structural changes or irreversible aggregation of proteins. Phase diagrams of various JM2 formulations were constructed, suggesting that the phase behavior of JM2 was dependent on the solution pH, ionic strength and the presence of other excipients such as glycine, alanine, sorbitol and sucrose. Furthermore, we demonstrated that for this mAb, the interaction parameter (k D ) determined at low protein concentration appeared to be a good predictor for the occurrence of LLPS at high concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Children's acceptance of milk with xylitol or sorbitol for dental caries prevention

    Directory of Open Access Journals (Sweden)

    Castillo Ramon

    2005-07-01

    Full Text Available Abstract Background Xylitol, a polyol sugar, has been shown to reduce dental caries when mixed with food or chewing gum. This study examines the taste acceptability of xylitol in milk as a first step toward measuring the effectiveness of xylitol in milk for the reduction of dental caries in a public health program. Methods Three different types of milk (Ultra High Temperature (UHT, powder and evaporated were tested for acceptability by 75 Peruvian children (25 per milk group, ages 4 to 7 years. Each group evaluated xylitol and sorbitol in one type of milk. In the first phase, each child was presented with a tray of four plastic cups containing 50 ml of milk with 0.021 g/ml xylitol, 0.042 g/ml xylitol, 0.042 g/ml sorbitol or no sugar. Each child was asked to taste the samples in a self-selected order. After tasting each sample, the child placed the milk cup in front of one of three cartoon faces (smile, frown or neutral representing the child's response to the taste of each sample. In the second phase, the child was asked to rank order the milk samples within each category (smile, frown or neutral. Ranks within categories were then combined to obtain a rank ordering for all the test samples. Results The ranking from best to worst for the samples across categories (UHT, powder, evaporated was xylitol (0.0.042 g/ml, sorbitol (0.042 g/ml, xylitol (0.021 g/ml and milk alone (Friedman's ANOVA. Xylitol and sorbitol were preferred over milk alone, and xylitol (0.042 g/ml was preferred to sorbitol (0.042 g/ml(p Conclusion Milk sweetened with xylitol is well accepted by Peruvian children ages 4–7 years.

  19. Increased risk of cataract development in WNIN-obese rats due to accumulation of intralenticular sorbitol.

    Science.gov (United States)

    Reddy, Paduru Yadagiri; Giridharan, Nappan Veettil; Balakrishna, Nagalla; Validandi, Vakdevi; Pullakhandam, Raghu; Reddy, Geereddy Bhanuprakash

    2013-05-01

    Epidemiological studies have reported an association between obesity and increased incidence of ocular complications including cataract, yet the underlying biochemical and molecular mechanisms remained unclear. Previously we had demonstrated accumulation of sorbitol in the lens of obese rats (WNIN/Ob) and more so in a related strain with impaired glucose tolerance (WNIN/GR-Ob). However, only a few (15-20%) WNIN/Ob and WNIN/GR-Ob rats develop cataracts spontaneously with age. To gain further insights, we investigated the susceptibility of eye lens proteins of these obese rat strains to heat- and UV-induced aggregation in vitro, lens opacification upon glucose-mediated sorbitol accumulation ex vivo, and onset and progression of cataract was followed by galactose feeding and streptozotocin (STZ) injection. The results indicated increased susceptibility toward heat- or UV-induced aggregation of lens proteins in obese animals compared to their littermate lean controls. Further, in organ culture studies glucose-induced sorbitol accumulation was found to be higher and thus the lens opacification was faster in obese animals compared to their lean littermates. Also, the onset and progression of galactose- or STZ-induced cataractogenesis was faster in obese animals compared to lean control. These results together with our previous observations suggest that obesity status could lead to hyperaccumulation of sorbitol in eye lens, predisposing them to cataract, primarily by increasing their susceptibility to environmental and/or physiological factors. Further, intralenticular sorbitol accumulation beyond a threshold level could lead to cataract in WNIN/Ob and WNIN/GR-Ob rats. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  20. Determination of mannitol sorbitol and myo-inositol in olive tree roots and rhizospheric soil by gas chromatography and effect of severe drought conditions on their profiles.

    Science.gov (United States)

    Mechri, Beligh; Tekaya, Meriem; Cheheb, Hechmi; Hammami, Mohamed

    2015-01-01

    This study reports a method for the analysis of mannitol, sorbitol and myo-inositol in olive tree roots and rhizospheric soil with gas chromatography. The analytical method consists of extraction with a mixture of dichloromethane:methanol (2:1, v/v) for soil samples and a mixture of ethanol:water (80:20) for root samples, silylation using pyridine, hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS). The recovery of mannitol sorbitol and myo-inositol (for extraction and analysis in dichloromethane:methanol and ethanol:water) was acceptable and ranged from 100.3 to 114.7%. The time of analysis was <24 min. Among identified polyols extracted from rhizosphere and roots of olive plants, mannitol was the major compound. A marked increase in mannitol content occurred in rhizosphere and roots of water-stressed plants, suggesting a much broader role of mannitol in stress response based on its ability to act as a compatible solute. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    overall absorption spectrum of a molecule is a superposition of many such sharp lines .... dilute solution of the enzyme and the substrate over few drops of silicone oil placed ..... Near-field Scanning Optical Microscopy (NSOM): Development.

  2. Simultaneous saccharification of inulin and starch using commercial glucoamylase and the subsequent bioconversion to high titer sorbitol and gluconic acid.

    Science.gov (United States)

    An, Kehong; Hu, Fengxian; Bao, Jie

    2013-12-01

    A new bioprocess for production of sorbitol and gluconic acid from two low-cost feedstocks, inulin and cassava starch, using a commercially available enzyme was proposed in this study. The commercial glucoamylase GA-L NEW from Genencor was found to demonstrate a high inulinase activity for hydrolysis of inulin into fructose and glucose. The glucoamylase was used to replace the expensive and not commercially available inulinase enzyme for simultaneous saccharification of inulin and starch into high titer glucose and fructose hydrolysate. The glucose and fructose in the hydrolysate were converted into sorbitol and gluconic acid using immobilized whole cells of the recombinant Zymomonas mobilis strain. The high gluconic acid concentration of 193 g/L and sorbitol concentration of 180 g/L with the overall yield of 97.3 % were obtained in the batch operations. The present study provided a practical production method of sorbitol and gluconic acid from low cost feedstocks and enzymes.

  3. Simultaneous catalytic conversion of cellulose and corncob xylan under temperature programming for enhanced sorbitol and xylitol production.

    Science.gov (United States)

    Ribeiro, Lucília Sousa; Órfão, José J de Melo; Pereira, Manuel Fernando Ribeiro

    2017-11-01

    Sorbitol and xylitol yields can be improved by converting cellulose and xylan simultaneously, due to a synergetic effect between both substrates. Furthermore, both yields can be greatly enhanced by simply adjusting the reaction conditions regarding the optimum for the production of each product, since xylitol (from xylan) and sorbitol (from cellulose) yields are maximized when the reaction is carried out at 170 and 205°C, respectively. Therefore, the combination of a simultaneous conversion of cellulose and xylan with a two-step temperature approach, which consists in the variation of the reaction temperature from 170 to 205°C after 2h, showed to be a good strategy for maximizing the production of sorbitol and xylitol directly from mixture of cellulose and xylan. Using this new and environmentally friendly approach, yields of sorbitol and xylitol of 75 and 77%, respectively, were obtained after 6h of reaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Caloric restriction counteracts age-related changes in the activities of sorbitol metabolizing enzymes from mouse liver

    Science.gov (United States)

    Hagopian, Kevork; Ramsey, Jon J.; Weindruch, Richard

    2009-01-01

    The influence of caloric restriction (CR) on hepatic sorbitol-metabolizing enzyme activities was investigated in young and old mice. Aldose reductase and sorbitol dehydrogenase activities were significantly lower in old CR mice than in old controls. Young CR mice showed decreased aldose reductase activity and a trend towards decreased sorbitol dehydrogenase when compared to controls. Metabolites of the pathway, namely sorbitol, glucose and fructose were decreased by CR in young and old mice. Pyruvate levels were decreased by CR in both young and old mice, while lactate decreased only in old CR. Malate levels increased in old CR but remained unchanged in young CR, when compared with controls. Accordingly, the lactae/pyruvate and malate/pyruvate ratios in young and old CR mice were increased, indicating increased NADH/NAD and NADPH/NADP redox couples, respectively. The results indicate that decreased glucose levels under CR conditions lead to decreased sorbitol pathway enzyme activities and metabolite levels, and could contribute to the beneficial effects of long-term CR through decreased sorbitol levels and NADPH sparing. PMID:18953666

  5. A highly efficient sorbitol dehydrogenase from Gluconobacter oxydans G624 and improvement of its stability through immobilization.

    Science.gov (United States)

    Kim, Tae-Su; Patel, Sanjay K S; Selvaraj, Chandrabose; Jung, Woo-Suk; Pan, Cheol-Ho; Kang, Yun Chan; Lee, Jung-Kul

    2016-09-16

    A sorbitol dehydrogenase (GoSLDH) from Gluconobacter oxydans G624 (G. oxydans G624) was expressed in Escherichia coli BL21(DE3)-CodonPlus RIL. The complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. GoSLDH exhibited Km and kcat values of 38.9 mM and 3820 s(-1) toward L-sorbitol, respectively. The enzyme exhibited high preference for NADP(+) (vs. only 2.5% relative activity with NAD(+)). GoSLDH sequencing, structure analyses, and biochemical studies, suggested that it belongs to the NADP(+)-dependent polyol-specific long-chain sorbitol dehydrogenase family. GoSLDH is the first fully characterized SLDH to date, and it is distinguished from other L-sorbose-producing enzymes by its high activity and substrate specificity. Isothermal titration calorimetry showed that the protein binds more strongly to D-sorbitol than other L-sorbose-producing enzymes, and substrate docking analysis confirmed a higher turnover rate. The high oxidation potential of GoSLDH for D-sorbitol was confirmed by cyclovoltametric analysis. Further, stability of GoSLDH significantly improved (up to 13.6-fold) after cross-linking of immobilized enzyme on silica nanoparticles and retained 62.8% residual activity after 10 cycles of reuse. Therefore, immobilized GoSLDH may be useful for L-sorbose production from D-sorbitol.

  6. Suppressing Sorbitol Synthesis Substantially Alters the Global Expression Profile of Stress Response Genes in Apple (Malus domestica) Leaves.

    Science.gov (United States)

    Wu, Ting; Wang, Yi; Zheng, Yi; Fei, Zhangjun; Dandekar, Abhaya M; Xu, Kenong; Han, Zhenhai; Cheng, Lailiang

    2015-09-01

    Sorbitol is a major product of photosynthesis in apple (Malus domestica) that is involved in carbohydrate metabolism and stress tolerance. However, little is known about how the global transcript levels in apple leaves respond to decreased sorbitol synthesis. In this study we used RNA sequencing (RNA-seq) profiling to characterize the transcriptome of leaves from transgenic lines of the apple cultivar 'Greensleeves' exhibiting suppressed expression of aldose-6-phosphate reductase (A6PR) to gain insights into sorbitol function and the consequences of decreased sorbitol synthesis on gene expression. We observed that, although the leaves of the low sorbitol transgenic lines accumulate higher levels of various primary metabolites, only very limited changes were found in the levels of transcripts associated with primary metabolism. We suggest that this is indicative of post-transcriptional and/or post-translational regulation of primary metabolite accumulation and central carbon metabolism. However, we identified significantly enriched gene ontology terms belonging to the 'stress related process' category in the antisense lines (P-value sorbitol plays a role in the responses of apple trees to abiotic and biotic stresses. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Erythritol Is More Effective Than Xylitol and Sorbitol in Managing Oral Health Endpoints

    Directory of Open Access Journals (Sweden)

    Peter de Cock

    2016-01-01

    Full Text Available Objective. To provide a comprehensive overview of published evidence on the impact of erythritol, a noncaloric polyol bulk sweetener, on oral health. Methods. A literature review was conducted regarding the potential effects of erythritol on dental plaque (biofilm, dental caries, and periodontal therapy. The efficacy of erythritol on oral health was compared with xylitol and sorbitol. Results. Erythritol effectively decreased weight of dental plaque and adherence of common streptococcal oral bacteria to tooth surfaces, inhibited growth and activity of associated bacteria like S. mutans, decreased expression of bacterial genes involved in sucrose metabolism, reduced the overall number of dental caries, and served as a suitable matrix for subgingival air-polishing to replace traditional root scaling. Conclusions. Important differences were reported in the effect of individual polyols on oral health. The current review provides evidence demonstrating better efficacy of erythritol compared to sorbitol and xylitol to maintain and improve oral health.

  8. Dose response of xylitol and sorbitol for epr retrospective dosimetry with applications to chewing gum

    International Nuclear Information System (INIS)

    Israelsson, A.; Gustafsson, H.; Lund, E.

    2013-01-01

    The purpose of this investigation was to study the radiation-induced electron paramagnetic resonance signal in sweeteners xylitol and sorbitol for use in retrospective dosimetry. For both sweeteners and chewing gum, the signal changed at an interval of 1-84 d after irradiation with minimal changes after 4-8 d. A dependence on storage conditions was noticed and the exposure of the samples to light and humidity was therefore minimised. Both the xylitol and sorbitol signals showed linearity with dose in the measured dose interval, 0-20 Gy. The dose-response measurements for the chewing gum resulted in a decision threshold of 0.38 Gy and a detection limit of 0.78 Gy. A blind test illustrated the possibility of using chewing gums as a retrospective dosemeter with an uncertainty in the dose determination of 0.17 Gy (1 SD). (authors)

  9. Fructose production by Zymomonas mobilis in fed-batch culture with minimal sorbitol formation

    Energy Technology Data Exchange (ETDEWEB)

    Edye, L A; Johns, M R; Ewings, K N

    1989-08-01

    Fed-batch cultures of Zymomonas mobilis (UQM 2864), a mutant unable to metabolise fructose, grown on diluted sugar cane syrup (200 g/l sucrose) achieved yields of 90.5 g/l fructose and 48.3 g/l ethanol with minimal sorbitol formation and complete utilization of the substrate. The effect of inoculum size on sorbitol formation in the batch stage of fed-batch fermentation are reported. Fermentation of sucrose (350 g/l) supplemented with nutrients yielded 142 g/l fructose and 76.5 g/l ethanol. Some fructose product loss at high fructose concentrations was observed. The fed-batch fermentation process offers a method for obtaining high concentrations of fructose and ethanol from sucrose materials. (orig.).

  10. Self-assembly mechanism of 1,3:2,4-di(3,4-dichlorobenzylidene)-D-sorbitol and control of the supramolecular chirality.

    Science.gov (United States)

    Li, Jingjing; Fan, Kaiqi; Guan, Xidong; Yu, Yingzhe; Song, Jian

    2014-11-11

    Dibenzylidene-D-sorbitol (DBS) and its derivatives are known to form gels in organic solvents; however, the mechanism of the gel formation has been a subject of much debate. The present work is undertaken to elucidate the organization mechanism of a DBS derivative, 1,3:2,4-di(3,4-dichlorobenzylidene)-D-sorbitol (DCDBS), by taking into account the solvent effects and comparing the experiment data with theoretical calculation. These molecules form smooth nonhelical fibers with a rest circular dichroism (CD) signal in polar solvents, in contrast to rope-liked left-helical fibers with a strong negative CD signal observed in nonpolar solvents. The molecular complexes thus formed were characterized by means of Fourier transform infrared spectra, ultraviolet-visible spectra, X-ray diffraction patterns, static contact angles, and theoretical calculations. It was proposed that the interactions between the gelator and the solvents could subtly change the stacking of the molecules and hence their self-assembled nanostructures. In nonpolar solvents, the gelator molecules appear as a distorted T-shaped structure with the 6-OH forming intermolecular hydrogen bonds with the acetal oxygens of adjacent gelator molecule. In addition, because of differential stacking interactions on both sides of the 10-member ring skeleton of the gelator, the oligomers may assemble in a helix fashion to minimize the energy, leading to helical fibers. In polar solvents, however, the gelator molecules show a rigid planelike structure and thus stack on top of each other because of strong parallel-displaced π interactions. The balanced driving force on both sides of the 10-member ring skeleton made it difficult for the dimers to bend, thus resulting in nonhelical nanostructure. As expected from the mechanisms proposed here, twisted ribbon fibers with a medium strength CD signal were obtained when solvents of different polarities were mixed. Thus, solvent effects revealed in this work represent an

  11. Effect of xylitol versus sorbitol: a quantitative systematic review of clinical trials.

    Science.gov (United States)

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2012-08-01

    This study aimed to appraise, within the context of tooth caries, the current clinical evidence and its risk for bias regarding the effects of xylitol in comparison with sorbitol. Databases were searched for clinical trials to 19 March 2011. Inclusion criteria required studies to: test a caries-related primary outcome; compare the effects of xylitol with those of sorbitol; describe a clinical trial with two or more arms, and utilise a prospective study design. Articles were excluded if they did not report computable data or did not follow up test and control groups in the same way. Individual dichotomous and continuous datasets were extracted from accepted articles. Selection and performance/detection bias were assessed. Sensitivity analysis was used to investigate attrition bias. Egger's regression and funnel plotting were used to investigate risk for publication bias. Nine articles were identified. Of these, eight were accepted and one was excluded. Ten continuous and eight dichotomous datasets were extracted. Because of high clinical heterogeneity, no meta-analysis was performed. Most of the datasets favoured xylitol, but this was not consistent. The accepted trials may be limited by selection bias. Results of the sensitivity analysis indicate a high risk for attrition bias. The funnel plot and Egger's regression results suggest a low publication bias risk. External fluoride exposure and stimulated saliva flow may have confounded the measured anticariogenic effect of xylitol. The evidence identified in support of xylitol over sorbitol is contradictory, is at high risk for selection and attrition bias and may be limited by confounder effects. Future high-quality randomised controlled trials are needed to show whether xylitol has a greater anticariogenic effect than sorbitol. © 2012 FDI World Dental Federation.

  12. Rapid conversion of sorbitol to isosorbide in hydrophobic ionic liquids under microwave irradiation.

    Science.gov (United States)

    Kamimura, Akio; Murata, Kengo; Tanaka, Yoshiki; Okagawa, Tomoki; Matsumoto, Hiroshi; Kaiso, Kouji; Yoshimoto, Makoto

    2014-12-01

    Sorbitol was effectively converted to isosorbide by treatment with [TMPA][NTf2 ] in the presence of catalytic amounts of TsOH under microwave heating at 180 °C. The reaction completed within 10 min and isosorbide was isolated to about 60%. Ionic liquids were readily recovered by an extraction treatment and reused several times. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Enhanced production of L-sorbose from D-sorbitol by improving the mRNA abundance of sorbitol dehydrogenase in Gluconobacter oxydans WSH-003.

    Science.gov (United States)

    Xu, Sha; Wang, Xiaobei; Du, Guocheng; Zhou, Jingwen; Chen, Jian

    2014-10-18

    Production of L-sorbose from D-sorbitol by Gluconobacter oxydans is the first step to produce L-ascorbic acid on industrial scale. The sldhAB gene, which encodes the sorbitol dehydrogenase (SLDH), was overexpressed in an industrial strain G. oxydans WSH-003 with a strong promoter, P tufB . To enhance the mRNA abundance, a series of artificial poly(A/T) tails were added to the 3'-terminal of sldhAB gene. Besides, their role in sldhAB overexpression and their subsequent effects on L-sorbose production were investigated. The mRNA abundance of the sldhAB gene could be enhanced in G. oxydans by suitable poly(A/T) tails. By self-overexpressing the sldhAB gene in G. oxydans WSH-003 with an optimal poly(A/T) tail under the constitutive promoter P tufB , the titer and the productivity of L-sorbose were enhanced by 36.3% and 25.0%, respectively, in a 1-L fermenter. Immobilization of G. oxydans-sldhAB6 cells further improved the L-sorbose titer by 33.7% after 20 days of semi-continuous fed-batch fermentation. The artificial poly(A/T) tails could significantly enhance the mRNA abundance of the sldhAB. Immobilized G. oxydans-sldhAB6 cells could further enlarge the positive effect caused by enhanced mRNA abundance of the sldhAB.

  14. Effect of Xylitol on Growth of Streptococcus pneumoniae in the Presence of Fructose and Sorbitol

    Science.gov (United States)

    Tapiainen, Terhi; Kontiokari, Tero; Sammalkivi, Laura; Ikäheimo, Irma; Koskela, Markku; Uhari, Matti

    2001-01-01

    Xylitol is effective in preventing acute otitis media by inhibiting the growth of Streptococcus pneumoniae. To clarify this inhibition we used fructose, which is known to block similar growth inhibition observed in Streptococcus mutans. In addition, we evaluated the efficacy of sorbitol in inhibiting the growth of pneumococci, as sorbitol is widely used for indications similar to those for which xylitol is used. The addition of 5% xylitol to the growth medium resulted in marked growth inhibition, an effect which was totally eliminated in the presence of 1, 2.5, or 5% fructose but not in the presence of 1 or 5% glucose, 1% galactose, or 1% sucrose. This finding implies that xylitol-induced inhibition of pneumococcal growth is mediated via the fructose phosphotransferase system in a way similar to that in which mutans group streptococcal growth is inhibited. The addition of sorbitol at concentrations of 1, 2.5, or 5% to the growth medium did not affect the growth of pneumococci and neither inhibited nor enhanced the xylitol-induced growth impairment. Thus, it seems that xylitol is the only commercially used sugar substitute proven to have an antimicrobial effect on pneumococci. PMID:11120960

  15. The influence of sorbitol on the production of cellulases and xylanases in an airlift bioreactor.

    Science.gov (United States)

    Ritter, Carla Eliana Todero; Fontana, Roselei Claudete; Camassola, Marli; da Silveira, Maurício Moura; Dillon, Aldo José Pinheiro

    2013-11-01

    The production of cellulases and xylanases by Penicillium echinulatum in an airlift bioreactor was evaluated. In batch production, we tested media with isolated or associated cellulose and sorbitol. In fed-batch production, we tested cellulose addition at two different times, 30 h and 48 h. Higher liquid circulation velocities in the downcomer were observed in sorbitol 10 g L(-1) medium. In batch production, higher FPA (filter paper activity) and endoglucanase activities were obtained with cellulose (7.5 g L(-1)) and sorbitol (2.5 g L(-1)), 1.0 U mL(-1) (120 h) and 6.4 U m L(-1) (100 h), respectively. For xylanases, the best production condition was cellulose 10 g L(-1), which achieved 5.5 U mL(-1) in 64 h. The fed-batch process was favorable for obtaining xylanases, but not for FPA and endoglucanases, suggesting that in the case of cellulases, the inducer must be added early in the process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Pt nanocatalysts supported on reduced graphene oxide for selective conversion of cellulose or cellobiose to sorbitol.

    Science.gov (United States)

    Wang, Ding; Niu, Wenqi; Tan, Minghui; Wu, Mingbo; Zheng, Xuejun; Li, Yanpeng; Tsubaki, Noritatsu

    2014-05-01

    Pt nanocatalysts loaded on reduced graphene oxide (Pt/RGO) were prepared by means of a convenient microwave-assisted reduction approach with ethylene glycol as reductant. The conversion of cellulose or cellobiose into sorbitol was used as an application reaction to investigate their catalytic performance. Various metal nanocatalysts loaded on RGO were compared and RGO-supported Pt exhibited the highest catalytic activity with 91.5 % of sorbitol yield from cellobiose. The catalytic performances of Pt nanocatalysts supported on different carbon materials or on silica support were also compared. The results showed that RGO was the best catalyst support, and the yield of sorbitol was as high as 91.5 % from cellobiose and 58.9 % from cellulose, respectively. The improvement of catalytic activity was attributed to the appropriate Pt particle size and hydrogen spillover effect of Pt/RGO catalyst. Interestingly, the size and dispersion of supported Pt particles could be easily regulated by convenient adjustment of the microwave heating temperature. The catalytic performance was found to initially increase and then decrease with increasing particle size. The optimum Pt particle size was 3.6 nm. These findings may offer useful guidelines for designing novel catalysts with beneficial catalytic performance for biomass conversion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Subcellular localization and vacuolar targeting of sorbitol dehydrogenase in apple seed.

    Science.gov (United States)

    Wang, Xiu-Ling; Hu, Zi-Ying; You, Chun-Xiang; Kong, Xiu-Zhen; Shi, Xiao-Pu

    2013-09-01

    Sorbitol is the primary photosynthate and translocated carbohydrate in fruit trees of the Rosaceae family. NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), which mainly catalyzes the oxidation of sorbitol to fructose, plays a key role in regulating sink strength in apple. In this study, we found that apple NAD-SDH was ubiquitously distributed in epidermis, parenchyma, and vascular bundle in developing cotyledon. NAD-SDH was localized in the cytosol, the membranes of endoplasmic reticulum and vesicles, and the vacuolar lumen in the cotyledon at the middle stage of seed development. In contrast, NAD-SDH was mainly distributed in the protein storage vacuoles in cotyledon at the late stage of seed development. Sequence analysis revealed there is a putative signal peptide (SP), also being predicated to be a transmembrane domain, in the middle of proteins of apple NAD-SDH isoforms. To investigate whether the putative internal SP functions in the vacuolar targeting of NAD-SDH, we analyzed the localization of the SP-deletion mutants of MdSDH5 and MdSDH6 (two NAD-SDH isoforms in apple) by the transient expression system in Arabidopsis protoplasts. MdSDH5 and MdSDH6 were not localized in the vacuoles after their SPs were deleted, suggesting the internal SP functions in the vacuolar targeting of apple NAD-SDH. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. Sweet taste in apple: the role of sorbitol, individual sugars, organic acids and volatile compounds

    Science.gov (United States)

    Aprea, Eugenio; Charles, Mathilde; Endrizzi, Isabella; Laura Corollaro, Maria; Betta, Emanuela; Biasioli, Franco; Gasperi, Flavia

    2017-03-01

    Sweetness is one of the main drivers of consumer preference, and thus is given high priority in apple breeding programmes. Due to the complexity of sweetness evaluation, soluble solid content (SSC) is commonly used as an estimation of this trait. Nevertheless, it has been demonstrated that SSC and sweet taste are poorly correlated. Though individual sugar content may vary greatly between and within apple cultivars, no previous study has tried to investigate the relationship between the amount of individual sugars, or ratios of these, and apple sweetness. In this work, we quantified the major sugars (sucrose, glucose, fructose, xylose) and sorbitol and explored their influence on perceived sweetness in apple; we also related this to malic acid content, SSC and volatile compounds. Our data confirmed that the correlation between sweetness and SSC is weak. We found that sorbitol content correlates (similarly to SSC) with perceived sweetness better than any other single sugar or total sugar content. The single sugars show no differentiable importance in determining apple sweetness. Our predictive model based on partial least squares regression shows that after sorbitol and SSC, the most important contribution to apple sweetness is provided by several volatile compounds, mainly esters and farnesene.

  19. Control of glucokinase translocation in rat hepatocytes by sorbitol and the cytosolic redox state.

    Science.gov (United States)

    Agius, L

    1994-02-15

    In rat hepatocytes cultured in 5 mM glucose, glucokinase activity is present predominantly in a bound state, and during permeabilization of the cells with digitonin in the presence of Mg2+ less than 20% of glucokinase activity is released. However, incubation of hepatocytes with a higher [glucose] [concn. giving half-maximal activation (A50) 15 mM] or with fructose (A50 50 microM) causes translocation of glucokinase from its Mg(2+)-dependent binding site to an alternative site [Agius and Peak (1993) Biochem. J. 296, 785-796]. A comparison of various substrates showed that sorbitol (A50 8 microM) was 6-fold more potent than fructose at causing glucokinase translocation, whereas tagatose was as potent and mannitol was > 10-fold less potent (A50 550 microM). These substrates also stimulate glucose conversion into glycogen with a similar relative potency, suggesting that conversion of glucose into glycogen is dependent on the binding and/or location of glucokinase within the hepatocyte. Ethanol and glycerol inhibited the effects of fructose, sorbitol and glucose on glucokinase translocation, whereas dihydroxy-acetone had a small additive effect at sub-maximal substrate stimulation. The converse effects of glycerol and dihydroxy-acetone suggest a role for the cytosolic NADH/NAD+ redox state in controlling glucokinase translocation. Titrations with three competitive inhibitors of glucokinase did not provide evidence for involvement of glucokinase flux in glucose-induced glucokinase translocation: N-acetylglucosamine inhibited glucose conversion into glycogen, but not glucose-induced glucokinase translocation; glucosamine partially suppressed glucose-induced and fructose-induced glucokinase translocation, at concentrations that caused total inhibition of glucose conversion into glycogen; D-mannoheptulose increased glucokinase release and had an additive effect with glucose. 3,3'-Tetramethylene-glutaric acid (5 mM), an inhibitor of aldose reductase, inhibited glucokinase

  20. Tuning the self-assembled 1,3:2,4-di(3,4-dimethylbenzylidene) sorbitol nanoarchitectures using the phase inversion method

    Science.gov (United States)

    Lai, Wei-Chi; Tseng, Shen-Jhen

    2013-11-01

    1,3:2,4-Di(3,4-dimethylbenzylidene) sorbitol (DMDBS) molecules can self-assemble into nanoscaled structures in organic solvents and polymer melts. The nanofibril structures were the mostly found. In this study, we used two phase inversion methods, i.e., dry and wet methods, to obtain different DMDBS nanoarchitectures. Poly(vinylidene fluoride) (PVDF) was chosen as polymer matrix, and the DMDBS structures were tuned by the process of PVDF membrane formation (crystallization and liquid-liquid demixing). When the membrane was prepared using the dry method, the DMDBS structure is controlled by the PVDF crystallization. Fewer DMDBS nanofibrils formed on the surfaces, and no nanofibrils were found in the cross-sections. On the other hand, when the membrane was prepared using the wet method, the liquid-liquid demixing (nonsolvent induced phase separation) occurred simultaneously as PVDF crystallized, and thus influenced the aggregation of DMDBS molecules. DMDBS is an amphiphilic molecule with two hydrophilic hydroxyl groups. The addition of nonsolvent (water) caused a large number of DMDBS molecules to aggregate outside the hydrophobic PVDF. In addition, a new structure "nanomat" was found. The mat was composed of DMDBS nanofibrils with diameters of 10-20 nm, similar to those observed in the dry method membranes. Fourier transform infra-red spectroscopy indicates that the DMDBS molecules self-assembled (aggregated) mainly through intermolecular hydrogen bonding in the presence of PVDF. The more intermolecular hydrogen bonding between DMDBS existed, the more excessive amounts of DMDBS molecules were, leading to the formation of nanomats.

  1. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex, E [Brookfield, IL; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL; Diaz, Rocio [Chicago, IL; Vukovic, Lela [Westchester, IL

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  2. Dietary sorbitol and mannitol: food content and distinct absorption patterns between healthy individuals and patients with irritable bowel syndrome.

    Science.gov (United States)

    Yao, C K; Tan, H-L; van Langenberg, D R; Barrett, J S; Rose, R; Liels, K; Gibson, P R; Muir, J G

    2014-04-01

    Sorbitol and mannitol are naturally-occurring polyol isomers. Although poor absorption and induction of gastrointestinal symptoms by sorbitol are known, the properties of mannitol are poorly described. We aimed to expand data on food composition of these polyols, and to compare their absorptive capacities and symptom induction in patients with irritable bowel syndrome (IBS) and healthy individuals. Food samples were analysed for sorbitol and mannitol content. The degree of absorption measured by breath hydrogen production and gastrointestinal symptoms (visual analogue scales) was evaluated in a randomised, double-blinded, placebo-controlled study in 21 healthy and 20 IBS subjects after challenges with 10 g of sorbitol, mannitol or glucose. Certain fruits and sugar-free gum contained sorbitol, whereas mannitol content was higher in certain vegetables. Similar proportions of patients with IBS (40%) and healthy subjects (33%) completely absorbed sorbitol, although more so with IBS absorbed mannitol (80% versus 43%; P = 0.02). Breath hydrogen production was similar in both groups after lactulose but was reduced in patients with IBS after both polyols. No difference in mean (SEM) hydrogen production was found in healthy controls after sorbitol [area-under-the-curve: 2766 (591) ppm 4 h(-1) ] or mannitol [2062 (468) ppm 4 h(-1) ] but, in patients with IBS, this was greater after sorbitol [1136 (204) ppm 4 h(-1) ] than mannitol [404 (154) ppm 4 h(-1) ; P = 0.002]. Overall gastrointestinal symptoms increased significantly after both polyols in patients with IBS only, although they were independent of malabsorption of either of the polyols. Increased and discordant absorption of mannitol and sorbitol occurs in patients with IBS compared to that in healthy controls. Polyols induced gastrointestinal symptoms in patients with IBS independently of their absorptive patterns, suggesting that the dietary restriction of polyols may be efficacious. © 2013 The

  3. Fructose and/or Sorbitol Intolerance in a Subgroup of Lactose Intolerant Patients

    Directory of Open Access Journals (Sweden)

    SR Mishkin

    1994-01-01

    Full Text Available The diagnosis and treatment of lactose intolerance often does not resolve all the symptoms of postcibal bloating and flatulence. Included in this study were 104 lactose intolerant patients (71 female, 33 male who complained of residual postcibal discomfort in spite of adherence to and benefit from appropriate measures for their documented lactose intolerance (at least 20 ppm H2 after 25 g lactose as well as appropriate symptomatic discomfort. Clinical characteristics common to this group included: symptomatic diarrhea (12.5%, history of foreign travel (5.8%, endoscopic and pathological evidence of gastritis and helicobacter infection (19.2 and 8.7%, respectively, nonspecific abnormalities of small bowel follow-through (15.4%, Crohn’s disease (8.7% and colonic cliverticulosis (14.4%. Intolerance co fructose (at least 10 ppm H2 after 25 g fructose plus appropriate symptoms or sorbitol (at least 10 ppm H2 after 5 g sorbitol plus appropriate symptoms was documented in 17.3 and 18.3%, respectively. Intolerance to both fructose and sorbicol (administered as separate challenges, more than twice as common as intolerance to either one alone, occurred in 41.4% and was independent of sex. In conclusion, additional carbohydrate intolerances contribute to postcibal discomfort in more than 75% of lactose intolerant patients who remain symptomatic in spite of adherence to appropriate measures for this condition. While 62% of all patients had benefited significantly (greater than 50% from appropriate dietary measures and enzyme replacement for lactose intolerance, only 40% of those who were also fructose intolerant and 47% who were sorbitol intolerant benefited (greater than 50% from appropriate dietary measures (no enzyme replacement yet available for intolerance to these sugars.

  4. One-pot aqueous phase catalytic conversion of sorbitol to gasoline over nickel catalyst

    International Nuclear Information System (INIS)

    Weng, Yujing; Qiu, Songbai; Xu, Ying; Ding, Mingyue; Chen, Lungang; Zhang, Qi; Ma, Longlong; Wang, Tiejun

    2015-01-01

    Highlights: • Directly production gasoline (C5–C12 alkanes) from biomass-derived sugar alcohol sorbitol. • Temperature of STG (553–593 K) was lower than that of traditional methanol to gasoline (MTG) (623–773 K). • Gasoline yield of 46.9% and C7–C12 hydrocarbons reached up to 45.5% in the gasoline products. - Abstract: The carbon chain extension and hydrodeoxygenation steps play critical roles in the high-energy-density hydrocarbons production. In this paper, a systematic study had been carried out to investigate one-pot aqueous phase catalytic conversion of sorbitol to gasoline (STG) over bifunctional Ni-based catalysts. Characterization technologies of N 2 physisorption, X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and NH 3 temperature-programmed desorption (NH 3 -TPD) were used to study the textural properties, phase compositions, acid behavior and morphologies of the catalysts. The catalytic performances were tested in a fixed bed reactor. It was found that the physically mixed Ni/HZSM-5 and Ni/silica-gel (mesoporous SG) catalyst realized the carbon chain extension and exhibited excellent performances on hydrodeoxygenation (HDO) reaction (46.9% of gasoline (C5–C12) yield and 45.5% of C7–C12 hydrocarbons in the gasoline products). Especially, the temperature of STG (553–593 K) was lower obviously than that of the traditional methanol to gasoline (MTG) process (623–773 K). It provided a novel transformation of sorbitol to long-chain alkanes by one-pot process over the bifunctional catalyst (Ni@HZSM-5/SG), wherein hydrodeoxygenation, ketonization and aldol condensation steps were integrated

  5. A mannitol/sorbitol receptor stimulates dietary intake in Tribolium castaneum.

    Science.gov (United States)

    Takada, Tomoyuki; Sato, Ryoichi; Kikuta, Shingo

    2017-01-01

    In insects, perception of chemical stimuli is involved in the acceptance or rejection of food. Gustatory receptors (Grs) that regulate external signals in chemosensory organs have been found in many insects. Tribolium castaneum, a major pest of stored products, possesses over 200 Gr genes. An expanded repertoire of Gr genes appears to be required for diet recognition in species that are generalist feeders; however, it remains unclear whether T. castaneum recognizes a suite of chemicals common to many products or whether its feeding is activated by specific chemicals, and whether its Grs are involved in feeding behavior. It is difficult to determine the food preferences of T. castaneum based on dietary intake due to a lack of appropriate methodology. This study established a novel dietary intake estimation method using gypsum, designated the TribUTE (Tribolium Urges To Eat) assay. For this assay, T. castaneum adults were fed a gypsum block without added organic compounds. Sweet preference was determined by adding sweeteners and measuring the amount of gypsum in the excreta. Mannitol was the strongest activator of T. castaneum dietary intake. In a Xenopus oocyte expression, TcGr20 was found to be responsible for mannitol and sorbitol responses, but not for responses to other tested non-volatile compounds. The EC50 values of TcGr20 for mannitol and sorbitol were 72.6 mM and 90.6 mM, respectively, suggesting that TcGr20 is a feasible receptor for the recognition of mannitol at lower concentrations. We used RNAi and the TribUTE assay to examine whether TcGr20 expression was involved in mannitol recognition. The amounts of excreta in TcGr20 dsRNA-injected adults decreased significantly, despite the presence of mannitol, compared to control adults. Taken together, our results indicate that T. castaneum adults recognized mannitol/sorbitol using the TcGr20 receptor, thereby facilitating the dietary intake of these compounds.

  6. Simultaneous separation and determination of fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD.

    Science.gov (United States)

    Ma, Chunmei; Sun, Zhen; Chen, Changbao; Zhang, Lili; Zhu, Shuhua

    2014-02-15

    A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was optimised for simultaneous determination of fructose, sorbitol, glucose and sucrose in fruits. The analysis was carried out on a Phenomenex Luna 5u NH₂ 100A column (250 mm × 4.60mm, 5 micron) with isocratic elution of acetonitrile:water (82.5:17.5, v/v). Drift tube temperature of the ELSD system was set to 82 °C and nitrogen flow rate was 2.0 L min⁻¹. The regression equation revealed good linear relationship (R = 0.9967-0.9989) within test ranges. The limits of detection (LOD) and quantification (LOQ) for four analytes (peach, apple, watermelon, and cherry fruits) were in the range of 0.07-0.27 and 0.22-0.91 mg L⁻¹, respectively. The proposed HPLC-ELSD method was validated for quantification of sugars in peach, apple, watermelon, and cherry fruits, and the results were satisfactory. The results showed that the contents of the four sugars varied among fruits. While fructose (5.79-104.01 mg g⁻¹) and glucose (9.25-99.62 mg g⁻¹) emerged as common sugars in the four fruits, sorbitol (8.70-19.13 mg g⁻¹) were only found in peach, apple and cherry fruits, and sucrose (15.82-106.39 mg g⁻¹) were in peach, apple and watermelon. There was not detectable sorbitol in watermelon and sucrose in cherry fruits, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Solvent-Free Polymerization of L-Aspartic Acid in the Presence of D-Sorbitol to Obtain Water Soluble or Network Copolymers

    Science.gov (United States)

    L-aspartic acid was thermally polymerized in the presence of D-sorbitol with the goal of synthesizing new, higher molecular weight water soluble and absorbent copolymers. No reaction occurred when aspartic acid alone was heated at 170 or 200 degrees C. In contrast, heating sorbitol and aspartic ac...

  8. Efeito da sacarose e sorbitol na conservação in vitro de Passiflora giberti N. E. Brown Sucrose and sorbitol effect in the in vitro conservation of Passiflora giberti N. E. Brown

    Directory of Open Access Journals (Sweden)

    Gláucia Amorim Faria

    2006-08-01

    Full Text Available Este trabalho teve como objetivo estudar o efeito da sacarose e do sorbitol na conservação in vitro de um acesso de Passiflora giberti N. E. Brown. Para isso, foi instalado um experimento no delineamento inteiramente casualizado, em que foi comparado o tratamento-testemunha (MS padrão com o meio MS suplementado com três concentrações de sacarose (0; 15 e 30 g L-1 em combinação com três concentrações de sorbitol (10; 20 e 40 g L-1. As avaliações foram realizadas aos 30; 60; 90 e 120 dias de incubação, observando-se o comprimento das brotações (cm, número de raízes, número e coloração das folhas. Os resultados mostram ser possível conservar sob crescimento lento, por quatro meses, microplantas de maracujazeiro em meio de cultura MS suplementado com 10 ou 20 g L-1 de sorbitol, na ausência de sacarose, e mantidas sob condições de fotoperíodo de 16 h (22 µE m-2s-1 e temperatura de 27 ± 1 ºC. A sacarose promoveu maior desenvolvimento de microplantas. A rizogênese é afetada pelo sorbitol na concentração de 40 g L-1 e pela ausência de sacarose no meio de cultura.This work objectified the study of sucrose and sorbitol effect in the in vitro conservation for Passiflora giberti N. E. Brown, access. Therefore, an experiment was conducted in a completely randomized design to compare control treatment (standard MS to MS medium supplemented with three sucrose concentrations (0, 15 and 30 g L-1 combined with three sorbitol concentrations (10, 20 and 40 g L-1, in a total of 10 treatments with 20 replicas. The experiment evaluation was carried out at 30, 60, 90 and 120 days of incubation, whereas the height of shoots (cm, number of roots, number and color of leaves were observed. The results showed the possibility to maintain passion-fruit microplants for a four months period under slow growth in MS medium supplemented with 10 or 20 g L-1 of sorbitol, without sucrose, and kept under 16 hours photoperiod (22 µ E m-2 s-1 and

  9. Consistent evidence to support the use of xylitol- and sorbitol-containing chewing gum to prevent dental caries

    DEFF Research Database (Denmark)

    Twetman, Svante

    2009-01-01

    DATA SOURCES: Studies were identified using searches with Medline, the Cochrane Library and Google Scholar. STUDY SELECTION: Studies were screened independently and were included if they evaluated the effect of one or more chewing gums containing at least one polyol (xylitol, sorbitol, mannitol...... randomised controlled trials (RCT) of which four were cluster RCT, nine controlled clinical trials (CCT) and four cohort studies]. Two RCT had a Jadad score of three or higher. The mean preventive fraction for the four main gum types are shown in the table 1, results of all except the sorbitol -mannitol...... blend were statistically significant. Sensitivity analyses confirmed the robustness of the findings. CONCLUSIONS: Although research gaps exist, particularly on optimal dosing and relative polyol efficacy, there is consistent evidence to support the use of xylitol- and sorbitol-containing chewing gum...

  10. Cryopreservation of boar semen by egg yolk-based extenders containing lactose or fructose is better than sorbitol.

    Science.gov (United States)

    Chanapiwat, Panida; Kaeoket, Kampon; Tummaruk, Padet

    2012-03-01

    The present study determined the effect of different types of sugars (lactose, fructose, glucose and sorbitol) used in egg yolk-based extender on the post-thawed boar semen quality. Twenty-two ejaculates from 6 fertility-proven Yorkshire boars were cryopreserved by liquid nitrogen vapor method. Sperm motility, viability, acrosome integrity and intact functional plasma membrane were determined at 0, 2 and 4 hr after thawing. It was found that the lactose-based extender resulted in a higher percentage of post-thawed sperm motility, viability, intact acrosome and functional plasma membrane than sorbitol-based extender (Pextender yielded a higher post-thawed sperm motility and viability than sorbitol-based extender (Pboar semen.

  11. Best combination of promoter and micellar catalyst for the rapid conversion of sorbitol to glucose

    Science.gov (United States)

    Mukherjee, Kakali; Ghosh, Aniruddha; Saha, Rumpa; Sar, Pintu; Malik, Susanta; Saha, Bidyut

    2014-03-01

    Kinetic data for oxidation of D-sorbitol to glucose by hexavalent chromium in aqueous medium and aqueous surfactant medium (SDS, TX-100) have been reported. Effect of promoter such as PA, bipy and phenanthroline on the reaction has been investigated. The reaction is performed under pseudo first order condition with an excess of substrate over the oxidant. The reaction is first order with respect to substrate and oxidant. The micelles have a catalytic effect on the reaction. Combination of phen and TX-100 produces almost twelve times increase in rate of oxidation.

  12. Edible Film from Polyblend of Ginger Starch, Chitosan, and Sorbitol as Plasticizer

    Science.gov (United States)

    Sariningsih, N.; Putra, Y. P.; Pamungkas, W. P.; Kusumaningsih, T.

    2018-03-01

    Polyblend ginger starch/chitosan based edible film has been succesfully prepared and characterized. The purpose of this research was to produce edible film from polyblend of ginger starch, chitosan, and sorbitol as plasticizer. The resulted edible film were characterized by using FTIR, TGA and UTM. Edible film of ginger starch had OH vibration (3430 cm-1). Besides, edible film had elongation up to 15.63%. The thermal degradation of this material reached 208°C indicating high termal stability. The water uptake of the edible film was 42.85%. It concluded that edible film produce in this research has potential as a packaging.

  13. Solution-processed small molecule:fullerene bulk-heterojunction solar cells: impedance spectroscopy deduced bulk and interfacial limits to fill-factors.

    Science.gov (United States)

    Guerrero, Antonio; Loser, Stephen; Garcia-Belmonte, Germà; Bruns, Carson J; Smith, Jeremy; Miyauchi, Hiroyuki; Stupp, Samuel I; Bisquert, Juan; Marks, Tobin J

    2013-10-21

    Using impedance spectroscopy, we demonstrate that the low fill factor (FF) typically observed in small molecule solar cells is due to hindered carrier transport through the active layer and hindered charge transfer through the anode interfacial layer (IFL). By carefully tuning the active layer thickness and anode IFL in BDT(TDPP)2 solar cells, the FF is increased from 33 to 55% and the PCE from 1.9 to 3.8%. These results underscore the importance of simultaneously optimizing active layer thickness and IFL in small molecule solar cells.

  14. Activation of sorbitol pathway in metabolic syndrome and increased susceptibility to cataract in Wistar-Obese rats.

    Science.gov (United States)

    Reddy, Paduru Yadagiri; Giridharan, Nappan Veettil; Reddy, Geereddy Bhanuprakash

    2012-01-01

    Obesity is a major public health problem worldwide, and of late, epidemiological studies indicate a preponderance of cataracts under obesity conditions. Although cataract is a multifactorial disorder and various biochemical mechanisms have been proposed, the influence of obesity on cataractogenesis has yet to be investigated. In such a scenario, a suitable animal model that develops cataract following the onset of obesity will be a welcome tool for biomedical research. Therefore, we investigated the molecular and biochemical basis for predisposition to cataract in the obese mutant rat models established in our institute because 15%-20% of these rats develop cataracts spontaneously as they reach 12-15 months of age. We analyzed the major biochemical pathways in the normal lenses of different age groups of our obese mutant rat strains, Wistar/Obese (WNIN/Ob) and WNIN/GR-Ob, the former with euglycemia and the latter with an additional impaired glucose tolerance trait. In addition, sorbitol levels were estimated in the cataractous lenses of the obese rats. Except for the polyol pathway, all the principal pathways of the lens remained unaltered. Therefore, sorbitol levels were found to be high in the normal eye lenses of obese rats (WNIN/Ob and WNIN/GR-Ob) compared to their lean controls from three months of age onwards. Between WNIN/Ob and WNIN/GR-Ob, the levels of sorbitol were higher in the latter, suggesting a synergistic effect of impaired glucose tolerance along with obesity in the activation of the sorbitol pathway. Either way, an elevated sorbitol pathway seemed to be the predisposing factor responsible for cataract formation in these mutant rats. Activation of the sorbitol pathway indeed enhances the risk of cataract development in conditions such as metabolic syndrome. These rat models thus may be valuable tools for investigating obesity-associated cataract and for developing intervention strategies, based on these findings.

  15. FORMULA OPTIMATION OF SENGGUGU ROOT BARK EXTRACT LOZENGES (Clerodendrum serratum (L. Moon. AS MUCOLYTIC AGENT WITH LACTOSE – SORBITOL FILLER COMBINATION

    Directory of Open Access Journals (Sweden)

    Wahyono Wahyono

    2015-11-01

    Full Text Available Senggugu root bark has mucolytic activity and has been used empirically, so it needs to be formulated as lozengeswhich can be used practically and comfortable for the patients. Senggugu root bark powder was extracted by maceration using aethanol 70%. Lozenges was optimized using lactose-sorbitol filler mix through three formulas, formula A ( 100% lactose, formula B (100% sorbitol, formula C (50% lactose-50% sorbitol. Lozenges was made by wet granulation method. The optimum formula was obtained from theresults of physical granul test and lozenges using SLD, and analyzed by its granul flow, hardness, dissolution time, and taste responsiveness, and also qualitative and quantitative analysis. The results show that lactose-sorbitol filler mix can increase hardness and taste responsiveness, decrease granul flow and dissolution time. The oprimum formula from this research is 100% sorbitol:0% lactose.

  16. Substrate inhibition: Oxidation of D-sorbitol and D-mannitol by potassium periodate in alkaline medium

    Science.gov (United States)

    Lakshman Kumar, Y.; Venkata Nadh, R.; Radhakrishnamurti, P. S.

    2014-05-01

    In the oxidation of D-sorbitol and D-mannitol by potassium periodate in alkaline media, substrate inhibition was observed with both substrates, i.e., a decrease in the rate of the reaction was observed with an increase in the concentration of substrate. The substrate inhibition was attributed to the formation of stable complex between the substrate and periodate. The reactions were found to be first order in case of periodate and a positive fractional order with hydroxide ions. Arrhenius parameters were calculated for the oxidation of sorbitol and mannitol by potassium periodate in alkali media.

  17. Plasma glucagon-like peptide 1 and peptide YY levels are not altered in symptomatic fructose-sorbitol malabsorption

    DEFF Research Database (Denmark)

    Valeur, Jørgen; Øines, Eliann; Morken, Mette Helvik

    2008-01-01

    consecutive patients with functional abdominal complaints, referred to our clinic for investigation of self-reported food hypersensitivity, were included in the study and compared with 15 healthy volunteers. All subjects ingested a mixture of 25 g fructose and 5 g sorbitol. Pulmonary hydrogen and methane...... excretion and plasma glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) levels were measured during the next 3 h. Both habitual and post-test symptoms were assessed. RESULTS: Malabsorption of fructose and sorbitol was present in 61% of the patients and 73% of the controls. Nevertheless, the patients...

  18. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 4. Molecule Matters – van der Waals Molecules - History and Some Perspectives on Intermolecular Forces. E Arunan. Feature Article Volume 14 Issue 4 April 2009 pp 346-356 ...

  19. Aging of the Johari-Goldstein relaxation in the glass-forming liquids sorbitol and xylitol

    Science.gov (United States)

    Yardimci, Hasan; Leheny, Robert L.

    2006-06-01

    Employing frequency-dependent dielectric susceptibility we characterize the aging in two supercooled liquids, sorbitol and xylitol, below their calorimetric glass transition temperatures. In addition to the alpha relaxation that tracks the structural dynamics, the susceptibility of both liquids possesses a secondary Johari-Goldstein relaxation at higher frequencies. Following a quench through the glass transition, the susceptibility slowly approaches the equilibrium behavior. For both liquids, the magnitude of the Johari-Goldstein relaxation displays a dependence on the time since the quench, or aging time, that is quantitatively very similar to the age dependence of the alpha peak frequency. The Johari-Goldstein relaxation time remains constant during aging for sorbitol while it decreases slightly with age for xylitol. Hence, one cannot sensibly assign a fictive temperature to the Johari-Goldstein relaxation. This behavior contrasts with that of liquids lacking distinct Johari-Goldstein peaks for which the excess wing of the alpha peak tracks the main part of the peak during aging, enabling the assignment of a single fictive temperature to the entire spectrum. The aging behavior of the Johari-Goldstein relaxation time further calls into question the possibility that the relaxation time possesses stronger temperature dependence in equilibrium than is observed in the out-of-equilibrium state below the glass transition.

  20. Metabolic engineering of Escherichia coli to enhance shikimic acid production from sorbitol.

    Science.gov (United States)

    Liu, Xianglei; Lin, Jun; Hu, Haifeng; Zhou, Bin; Zhu, Baoquan

    2014-09-01

    Shikimic acid (SA) is the key synthetic material of Oseltamivir, which is an effective drug for the prevention and treatment of influenza. In this study, to block the downstream metabolic pathway of SA, the shikimate kinase isoenzyme genes aroK and aroL were deleted by Red recombination. Moreover, the key enzyme genes aroG, aroB, tktA and aroE of SA pathway were co-expressed by constructing the recombinant vector pETDuet-GBAE. As a result, SA production of E. coli BW25113 (∆aroL/aroK, DE3)/pETDuet-GBAE reached 1,077.6 mg/l when low amounts of sorbitol (5 g/l) were fed in shake flasks. The yield was 3.7 times that when glucose was used (P sorbitol was an optimized carbon source for the high efficient accumulation of SA for the first time, which was applicable to use in the industry for high yields and low consumption.

  1. Acoustic excitations in glassy sorbitol and their relation with the fragility and the boson peak

    Science.gov (United States)

    Ruta, B.; Baldi, G.; Scarponi, F.; Fioretto, D.; Giordano, V. M.; Monaco, G.

    2012-12-01

    We report a detailed analysis of the dynamic structure factor of glassy sorbitol by using inelastic X-ray scattering and previously measured light scattering data [B. Ruta, G. Monaco, F. Scarponi, and D. Fioretto, Philos. Mag. 88, 3939 (2008), 10.1080/14786430802317586]. The thus obtained knowledge on the density-density fluctuations at both the mesoscopic and macroscopic length scale has been used to address two debated topics concerning the vibrational properties of glasses. The relation between the acoustic modes and the universal boson peak (BP) appearing in the vibrational density of states of glasses has been investigated, also in relation with some recent theoretical models. Moreover, the connection between the elastic properties of glasses and the slowing down of the structural relaxation process in supercooled liquids has been scrutinized. For what concerns the first issue, it is here shown that the wave vector dependence of the acoustic excitations can be used, in sorbitol, to quantitatively reproduce the shape of the boson peak, supporting the relation between BP and acoustic modes. For what concerns the second issue, a proper study of elasticity over a wide spatial range is shown to be fundamental in order to investigate the relation between elastic properties and the slowing down of the dynamics in the corresponding supercooled liquid phase.

  2. Highly efficient red fluorescent organic light-emitting diodes by sorbitol-doped PEDOT:PSS

    Science.gov (United States)

    Zheng, Yan-Qiong; Yu, Jun-Le; Wang, Chao; Yang, Fang; Wei, Bin; Zhang, Jian-Hua; Zeng, Cheng-Hui; Yang, Yang

    2018-06-01

    This work shows a promising approach to improve device performance by optimizing the electron transport and hole injection layers for tetraphenyldibenzoperiflanthene (DBP):rubrene-based red fluorescent organic light-emitting diodes (OLEDs). We compared the effect of two electron transport layers (ETLs), and found that the rubrene/bathophenanthroline (Bphen) ETL-based OLED showed a much higher external quantum efficiency (EQE) (4.67%) than the Alq3 ETL-based OLED (EQE of 3.08%). The doping ratio of DBP in rubrene was tuned from 1.0 wt% to 4.5 wt%, and the 1.5 wt%-DBP:rubrene-based OLED demonstrated the highest EQE of 5.24% and lowest turn-on voltage of 2.2 V. Atomic force microscopy images indicated that 1.5 wt% DBP-doped rubrene film exhibited a regular strip shape, and this regular surface was favorable to the hole and electron recombination in the emitting layer. Finally, the sorbitol-doped poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was used to further improve the EQE; doping with 6 wt% sorbitol achieved the highest current efficiency of 7.03 cd A‑1 and an EQE of 7.50%. The significantly enhanced performance implies that the hole injection is a limiting factor for DBP:rubrene-based red fluorescent OLEDs.

  3. Reference interaction site model with hydrophobicity induced density inhomogeneity: An analytical theory to compute solvation properties of large hydrophobic solutes in the mixture of polyatomic solvent molecules

    International Nuclear Information System (INIS)

    Cao, Siqin; Sheong, Fu Kit; Huang, Xuhui

    2015-01-01

    Reference interaction site model (RISM) has recently become a popular approach in the study of thermodynamical and structural properties of the solvent around macromolecules. On the other hand, it was widely suggested that there exists water density depletion around large hydrophobic solutes (>1 nm), and this may pose a great challenge to the RISM theory. In this paper, we develop a new analytical theory, the Reference Interaction Site Model with Hydrophobicity induced density Inhomogeneity (RISM-HI), to compute solvent radial distribution function (RDF) around large hydrophobic solute in water as well as its mixture with other polyatomic organic solvents. To achieve this, we have explicitly considered the density inhomogeneity at the solute-solvent interface using the framework of the Yvon-Born-Green hierarchy, and the RISM theory is used to obtain the solute-solvent pair correlation. In order to efficiently solve the relevant equations while maintaining reasonable accuracy, we have also developed a new closure called the D2 closure. With this new theory, the solvent RDFs around a large hydrophobic particle in water and different water-acetonitrile mixtures could be computed, which agree well with the results of the molecular dynamics simulations. Furthermore, we show that our RISM-HI theory can also efficiently compute the solvation free energy of solute with a wide range of hydrophobicity in various water-acetonitrile solvent mixtures with a reasonable accuracy. We anticipate that our theory could be widely applied to compute the thermodynamic and structural properties for the solvation of hydrophobic solute

  4. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    International Nuclear Information System (INIS)

    Maulida; Siagian, M; Tarigan, P

    2016-01-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment. (paper)

  5. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    Science.gov (United States)

    Maulida; Siagian, M.; Tarigan, P.

    2016-04-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment.

  6. Hybrid neural network model for simulating sorbitol synthesis by glucose-fructose oxidoreductase in Zymomonas mobilis CP4

    Directory of Open Access Journals (Sweden)

    Bravo S.

    2004-01-01

    Full Text Available A hybrid neural network model for simulating the process of enzymatic reduction of fructose to sorbitol process catalyzed by glucose-fructose oxidoreductase in Zymomonas mobilis CP4 is presented. Data used to derive and validate the model was obtained from experiments carried out under different conditions of pH, temperature and concentrations of both substrates (glucose and fructose involved in the reaction. Sonicated and lyophilized cells were used as source of the enzyme. The optimal pH for sorbitol synthesis at 30º C is 6.5. For a value of pH of 6, the optimal temperature is 35º C. The neural network in the model computes the value of the kinetic relationship. The hybrid neural network model is able to simulate changes in the substrates and product concentrations during sorbitol synthesis under pH and temperature conditions ranging between 5 and 7.5 and 25 and 40º C, respectively. Under these conditions the rate of sorbitol synthesis shows important differences. Values computed using the hybrid neural network model have an average error of 1.7·10-3 mole.

  7. Atkins' molecules

    CERN Document Server

    Atkins, Peters

    2003-01-01

    Originally published in 2003, this is the second edition of a title that was called 'the most beautiful chemistry book ever written'. In it, we see the molecules responsible for the experiences of our everyday life - including fabrics, drugs, plastics, explosives, detergents, fragrances, tastes, and sex. With engaging prose Peter Atkins gives a non-technical account of an incredible range of aspects of the world around us, showing unexpected connections, and giving an insight into how this amazing world can be understood in terms of the atoms and molecules from which it is built. The second edition includes dozens of extra molecules, graphical presentation, and an even more accessible and enthralling account of the molecules themselves.

  8. Interstellar Molecules

    Science.gov (United States)

    Solomon, Philip M.

    1973-01-01

    Radioastronomy reveals that clouds between the stars, once believed to consist of simple atoms, contain molecules as complex as seven atoms and may be the most massive objects in our Galaxy. (Author/DF)

  9. Fed-batch methanol feeding strategy for recombinant protein production by Pichia pastoris in the presence of co-substrate sorbitol.

    Science.gov (United States)

    Celik, Eda; Calik, Pinar; Oliver, Stephen G

    2009-09-01

    Batch-wise sorbitol addition as a co-substrate at the induction phase of methanol fed-batch fermentation by Pichia pastoris (Mut(+)) was proposed as a beneficial recombinant protein production strategy and the metabolic responses to methanol feeding rate in the presence of sorbitol was systematically investigated. Adding sorbitol batch-wise to the medium provided the following advantages over growth on methanol alone: (a) eliminating the long lag-phase for the cells and reaching 'high cell density production' at t = 24 h of the process (C(X) = 70 g CDW/l); (b) achieving 1.8-fold higher recombinant human erythropoietin (rHuEPO) (at t = 18 h); (c) reducing specific protease production 1.2-fold; (d) eliminating the lactic acid build-up period; (e) lowering the oxygen uptake rate two-fold; and (f) obtaining 1.4-fold higher overall yield coefficients. The maximum specific alcohol oxidase activity was not affected in the presence of sorbitol, and it was observed that sorbitol and methanol were utilized simultaneously. Thus, in the presence of sorbitol, 130 mg/l rHuEPO was produced at t = 24 h, compared to 80 mg/l rHuEPO (t = 24 h) on methanol alone. This work demonstrates not only the ease and efficiency of incorporating sorbitol to fermentations by Mut(+) strains of P. pastoris for the production of any bio-product, but also provides new insights into the metabolism of the methylotrophic yeast P. pastoris.

  10. Sorbitol increases muscle glucose uptake ex vivo and inhibits intestinal glucose absorption ex vivo and in normal and type 2 diabetic rats.

    Science.gov (United States)

    Chukwuma, Chika Ifeanyi; Islam, Md Shahidul

    2017-04-01

    Previous studies have suggested that sorbitol, a known polyol sweetener, possesses glycemic control potentials. However, the effect of sorbitol on intestinal glucose absorption and muscle glucose uptake still remains elusive. The present study investigated the effects of sorbitol on intestinal glucose absorption and muscle glucose uptake as possible anti-hyperglycemic or glycemic control potentials using ex vivo and in vivo experimental models. Sorbitol (2.5% to 20%) inhibited glucose absorption in isolated rat jejuna (IC 50 = 14.6% ± 4.6%) and increased glucose uptake in isolated rat psoas muscle with (GU 50 = 3.5% ± 1.6%) or without insulin (GU 50 = 7.0% ± 0.5%) in a concentration-dependent manner. Furthermore, sorbitol significantly delayed gastric emptying, accelerated digesta transit, inhibited intestinal glucose absorption, and reduced blood glucose increase in both normoglycemic and type 2 diabetic rats after 1 h of coingestion with glucose. Data of this study suggest that sorbitol exhibited anti-hyperglycemic potentials, possibly via increasing muscle glucose uptake ex vivo and reducing intestinal glucose absorption in normal and type 2 diabetic rats. Hence, sorbitol may be further investigated as a possible anti-hyperglycemic sweetener.

  11. Effects of olestra and sorbitol consumption on objective measures of diarrhea: impact of stool viscosity on common gastrointestinal symptoms.

    Science.gov (United States)

    McRorie, J; Zorich, N; Riccardi, K; Bishop, L; Filloon, T; Wason, S; Giannella, R

    2000-02-01

    The aim of this study was to determine the effects of olestra and sorbitol consumption on three accepted objective measures of diarrhea (stool output >250 g/day, liquid/watery stools, bowel movement frequency >3/day), and how stool composition influences reports of common gastrointestinal symptoms. A double-blind, placebo-controlled study compared the effects of sorbitol (40 g/day in candy), a poorly absorbed sugar-alcohol with known osmotic effects, with those of olestra (20 or 40 g/day in potato chips), a nonabsorbed fat, on objective measures of stool composition and GI symptoms. Sixty-six subjects resided on a metabolic ward for 12 days: 2 days lead-in, 4 days baseline, 6 days treatment. Sorbitol 40 g/day resulted in loose/liquid stools within 1-3 h of consumption. In contrast, olestra resulted in a dose-responsive stool softening effect after 2-4 days of consumption. Subjects reported "diarrhea" when mean stool apparent viscosity (peak force (PF), g) decreased from a perceived "normal" (mean +/- SE, 1355 +/- 224 g PF; firm stool) to loose (260 +/- 68 g PF) stool. Mean apparent viscosity of stool during treatment: placebo, 1363 +/- 280 g (firm); olestra 20 g/day 743 +/- 65 g (soft); olestra 40 g/day, 563 +/- 105 g (soft); and sorbitol 40 g/day, 249 +/- 53 g (loose). Of the 1098 stool samples collected, 38% (419/1098) were rated by subjects as "diarrhea," yet only 2% of treatment days (all in the sorbitol treatment group) met commonly accepted criteria for a clinical diarrhea. Sorbitol, but not olestra, increased the severity of abdominal cramping, urgency and nausea compared to placebo. Olestra consumption, at levels far in excess of normal snacking conditions, resulted in a gradual stool softening effect after several days of consumption, did not meet any of the three objective measures of diarrhea, and did not increase GI symptoms. Sorbitol consumption, at only 80% of the dose requiring a "laxative effect" information label, resulted in rapid onset loose

  12. A mannitol/sorbitol receptor stimulates dietary intake in Tribolium castaneum.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Takada

    Full Text Available In insects, perception of chemical stimuli is involved in the acceptance or rejection of food. Gustatory receptors (Grs that regulate external signals in chemosensory organs have been found in many insects. Tribolium castaneum, a major pest of stored products, possesses over 200 Gr genes. An expanded repertoire of Gr genes appears to be required for diet recognition in species that are generalist feeders; however, it remains unclear whether T. castaneum recognizes a suite of chemicals common to many products or whether its feeding is activated by specific chemicals, and whether its Grs are involved in feeding behavior. It is difficult to determine the food preferences of T. castaneum based on dietary intake due to a lack of appropriate methodology. This study established a novel dietary intake estimation method using gypsum, designated the TribUTE (Tribolium Urges To Eat assay. For this assay, T. castaneum adults were fed a gypsum block without added organic compounds. Sweet preference was determined by adding sweeteners and measuring the amount of gypsum in the excreta. Mannitol was the strongest activator of T. castaneum dietary intake. In a Xenopus oocyte expression, TcGr20 was found to be responsible for mannitol and sorbitol responses, but not for responses to other tested non-volatile compounds. The EC50 values of TcGr20 for mannitol and sorbitol were 72.6 mM and 90.6 mM, respectively, suggesting that TcGr20 is a feasible receptor for the recognition of mannitol at lower concentrations. We used RNAi and the TribUTE assay to examine whether TcGr20 expression was involved in mannitol recognition. The amounts of excreta in TcGr20 dsRNA-injected adults decreased significantly, despite the presence of mannitol, compared to control adults. Taken together, our results indicate that T. castaneum adults recognized mannitol/sorbitol using the TcGr20 receptor, thereby facilitating the dietary intake of these compounds.

  13. Small Molecules Derived from Thieno[3,4-c]pyrrole-4,6-dione (TPD) and Their Use in Solution Processed Organic Solar Cells.

    Science.gov (United States)

    Garcias-Morales, Cesar; Romero-Borja, Daniel; Maldonado, José-Luis; Roa, Arián E; Rodríguez, Mario; García-Merinos, J Pablo; Ariza-Castolo, Armando

    2017-09-30

    In this work, microwave synthesis, chemical, optical and electrochemical characterization of three small organic molecules, TPA-TPD , TPA-PT-TPD and TPA-TT-TPD with donor-acceptor structure and their use in organic photovoltaic cells are reported. For the synthesis, 5-(2-ethylhexyl)-4 H -thieno[3,4- c ]pyrrole-4,6(5 H )-dione was used as electron withdrawing fragment while the triphenylamine was used as electron donating fragment. Molecular electronic geometry and electronic distribution density were established by density functional theory (DFT) calculations and confirmed by optical and chemical characterization. These molecules were employed as electron-donors in the active layer for manufacturing bulk heterojunction organic solar cells, where [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) was used as electron-acceptor. As cathode, Field's metal (FM), an eutectic alloy (Bi/In/Sn: 32.5%, 51%, and 16.5%, respectively) with a melting point above 62 °C, was easily deposited by drop casting under vacuum-free process and at air atmosphere. Prepared devices based on TPA-TPD :PC71BM (1:4 w / w ratio) presented a large V OC = 0.97 V, with J SC = 7.9 mA/cm², a FF = 0.34, then, a power conversion efficiency (PCE) of 2.6%.

  14. Synergistic Inhibition of Protein Fibrillation by Proline and Sorbitol: Biophysical Investigations.

    Directory of Open Access Journals (Sweden)

    Sinjan Choudhary

    Full Text Available We report here interesting synergistic effects of proline and sorbitol, two well-known chemical chaperones, in the inhibition of fibrillation of two proteins, insulin and lysozyme. A combination of many biophysical techniques has been used to understand the structural morphology and modes of interaction of the chaperones with the proteins during fibrillation. Both the chaperones establish stronger polar interactions in the elongation and saturation stages of fibrillation compared to that in the native stage. However, when presented as a mixture, we also see contribution of hydrophobic interactions. Thus, a co-operative adjustment of polar and hydrophobic interactions between the chaperones and the protein surface seems to drive the synergistic effects in the fibrillation process. In insulin, this synergy is quantitatively similar in all the stages of the fibrillation process. These observations would have significant implications for understanding protein folding concepts, in general, and for designing combination therapies against protein fibrillation, in particular.

  15. Interfacial enhancement of polypropylene composites modified with sorbitol derivatives and siloxane-silsesquioxane resin

    Science.gov (United States)

    Dobrzyńska-Mizera, Monika; Dutkiewicz, Michał; Sterzyński, Tomasz; Di Lorenzo, Maria Laura

    2015-12-01

    Composites based on polypropylene (iPP) modified with a sorbitol derivative (NX8000) and siloxane-silsesquioxane resin (SiOPh) containing maleated polypropylene (MAPP) as compatibilizer were prepared by melt extrusion. Calorimetric investigations were carried out using differential scanning calorimetry (DSC), whereas the morphological and mechanical properties were investigated by scanning electron microscopy (SEM) and static tensile tests. DSC measurements revealed no influence of SiOPh and a slight effect of MAPP addition on the crystallization kinetics of polypropylene. Additionally, the introduction of MAPP into the iPP+NX8000+SiOPh composites increased plastic properties of the samples. All the above was attributed to the compatibilizing effect of MAPP which improved interfacial adhesion between iPP, NX8000 and SiOPh. This phenomenon was also confirmed by the SEM images illustrating more homogenous distribution of the filler in the compatibilized samples.

  16. Synergistic Inhibition of Protein Fibrillation by Proline and Sorbitol: Biophysical Investigations.

    Science.gov (United States)

    Choudhary, Sinjan; Save, Shreyada N; Kishore, Nand; Hosur, Ramakrishna V

    2016-01-01

    We report here interesting synergistic effects of proline and sorbitol, two well-known chemical chaperones, in the inhibition of fibrillation of two proteins, insulin and lysozyme. A combination of many biophysical techniques has been used to understand the structural morphology and modes of interaction of the chaperones with the proteins during fibrillation. Both the chaperones establish stronger polar interactions in the elongation and saturation stages of fibrillation compared to that in the native stage. However, when presented as a mixture, we also see contribution of hydrophobic interactions. Thus, a co-operative adjustment of polar and hydrophobic interactions between the chaperones and the protein surface seems to drive the synergistic effects in the fibrillation process. In insulin, this synergy is quantitatively similar in all the stages of the fibrillation process. These observations would have significant implications for understanding protein folding concepts, in general, and for designing combination therapies against protein fibrillation, in particular.

  17. Change in organic molecule adhesion on α-alumina (Sapphire) with change in NaCl and CaCl2 solution salinity

    DEFF Research Database (Denmark)

    Juhl, Klaus; Bovet, Nicolas Emile; Hassenkam, Tue

    2014-01-01

    We investigated the adhesion of two functional groups to α-alumina as a model for the adsorption of organic molecules on clay minerals. Interactions between organic compounds and clay minerals play an important role in processes such as drinking water treatment, remediation of contaminated soil...... the growth of bones, teeth, and shells. Adhesion of carboxylic acid, -COO(H), and pyridine, -C5H5N(H+), on the {0001} plane of α-alumina wafers has been investigated with atomic force microscopy (AFM) in chemical force mapping (CFM) mode. Both functional groups adhered to α-alumina in deionized water at p...... in surface properties, controlling surface tension (i.e., contact angle) and adsorption affinity on α-alumina and, by analogy, on clay minerals....

  18. Effective Production of Sorbitol and Mannitol from Sugars Catalyzed by Ni Nanoparticles Supported on Aluminium Hydroxide

    Directory of Open Access Journals (Sweden)

    Rodiansono Rodiansono

    2013-06-01

    Full Text Available Effective production of hexitols (sorbitol and mannitol was achieved from sugars by means of nickel nanoparticles supported on aluminium hydroxide (NiNPs/AlOH catalyst. NiNPs/AlOH catalyst was prepared by a simple and benign environmentally procedure using less amount of sodium hydroxide. ICP-AES and XRD analyses confirmed that the NiNPs/AlOH catalysts comprised a large amount of remained aluminium hydroxide (i.e. bayerite and gibbsite. The presence of aluminium hydroxide caused a high dispersion Ni metal species. The average Ni crystallite sizes that derived from the Scherrer`s equation for former R-Ni and NiNPs/AlOH were 8.6 nm and 4.1 nm, respectively. The catalyst exhibited high activity and selectivity both hydrogenolysis of disaccharides (sucrose and cellobiose and monosaccharides (glucose, fructose, and xylose at 403 K for 24 h. The NiNPs/AlOH catalyst was found to be reusable for at least five consecutive runs without any significant loss of activity and selectivity. © 2013 BCREC UNDIP. All rights reservedReceived: 21st December 2012; Revised: 7th February 2013; Accepted: 10th February 2013[How to Cite: Rodiansono, R., Shimazu, S. (2013. Effective Production of Sorbitol and Mannitol from Sug-ars Catalyzed by Ni Nanoparticles Supported on Aluminium Hydroxide. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 40-46. (doi:10.9767/bcrec.8.1.4290.40-46][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4290.40-46] | View in  |

  19. Demonstration of a SANEX Process in Centrifugal Contactors using the CyMe{sub 4}-BTBP Molecule on a Genuine Fuel Solution

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, D.; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D. [European Commiss, Joint Res Ctr, Inst Transuranium Elements, D-76125 Karlsruhe, (Germany); Foreman, M.R.S. [Univ Reading, Dept Chem, Reading RG6 6AD, Berks, (United Kingdom); Geist, A. [Forschungszentrum Karlsruhe, Inst Nukl Entsorgung, D-76021 Karlsruhe, (Germany); Modolo, G. [Forschungszentrum Julich, Inst Energy Res Safety Res and Reactor Technol, D-52425 Julich, (Germany); Sorel, C. [Commissariat Energie Atom Valrho, CEA, DRCP SCPS, F-30207 Bagnols Sur Ceze, (France)

    2009-07-01

    Efficient recovery of minor actinides from a genuine spent fuel solution has been successfully demonstrated by the CyMe{sub 4}-BTBP/DMDOHEMA extractant mixture dissolved in octanol. The continuous countercurrent process, in which actinides(III) were separated from lanthanides(III), was carried out in laboratory centrifugal contactors using an optimized flow-sheet involving a total of 16 stages. The process was divided into 9 stages for extraction from a 2 M nitric acid feed solution, 3 stages for lanthanide scrubbing, and 4 stages for actinide back-extraction. Excellent feed decontamination factors for Am (7000) and Cm (1000) were obtained and the recoveries of these elements were higher than 99.9%. More than 99.9% of the lanthanides were directed to the raffinate except Gd for which 0.32% was recovered in the product. (authors)

  20. Adhesion molecules

    CERN Document Server

    Preedy, Victor R

    2016-01-01

    This book covers the structure and classification of adhesion molecules in relation to signaling pathways and gene expression. It discusses immunohistochemical localization, neutrophil migration, and junctional, functional, and inflammatory adhesion molecules in pathologies such as leukocyte decompression sickness and ischemia reperfusion injury. Highlighting the medical applications of current research, chapters cover diabetes, obesity, and metabolic syndrome; hypoxia; kidney disease; smoking, atrial fibrillation, and heart disease, the brain and dementia; and tumor proliferation. Finally, it looks at molecular imaging and bioinformatics, high-throughput technologies, and chemotherapy.

  1. Hydroxy protons as structural probes to reveal hydrogen bonding properties of polyols in aqueous solution by NMR spectroscopy

    Science.gov (United States)

    Oruc, Gizem; Varnali, Tereza; Bekiroglu, Somer

    2018-05-01

    The solution properties of ethylene glycol (ethane-1,2-diol), glycerol (propane-1,2,3-triol), erythritol ((2R,3S)-butane-1,2,3,4-tetraol), D-xylitol ((2R,3r,4S)-pentane-1,2,3,4,5-pentaol), D-mannitol ((2R,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), and D-sorbitol ((2S,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), constituting a subgroup of polyalcohols/polyols of maximum six carbon atoms have been investigated using 1H NMR chemical shifts, coupling constants, temperature coefficients, and chemical exchange rates of hydroxy protons in aqueous medium. Relative within a molecule, minimum two-fold difference in rate of exchange values and higher temperature dependence of chemical shifts of the hydroxy protons on terminal carbon atoms confirm that sustainable hydrogen bonding interactions is accentuated for the hydroxyl groups on secondary carbons. Compared to the primary carbons i.e. terminal ones, the hydroxy protons on second and third carbon atoms exhibit much lower rate of exchange and smaller temperature coefficients, indicating that they are further involved in transient hydrogen bonding interactions. Scalar 3JOH,CH-couplings ranging between 3.9 and 7.2 Hz imply that the hydroxyl groups are practically in free rotation regime. Examination of the chemical shift differences with respect to the shift of glycol hydroxy proton reveals that the disparity between terminal and inner hydroxyl groups disclosed by the exchange rates and temperature coefficients is sustained with the exception of 0.003 and 0.053 ppm for O(3)H of mannitol and O(5)H of sorbitol respectively. The experimental findings have been augmented by quantum chemical calculations targeting theoretical NMR chemical shifts, as well as the conformational analysis of the structures.

  2. Structural and thermodynamic aspects of aqueous solution of trivalent lanthanides complexation by hydrophobic compounds of tartaric acid, by gluconic acid and related molecules. Outlook for liquid-liquid extraction of these cations

    International Nuclear Information System (INIS)

    Giroux, Sebastien

    1999-01-01

    This work deals with the complexation of lanthanide(III) ions by different molecules and with the synthesis of hydrophobic molecules able to extract them of an aqueous solution. Its aim is to describe the systems obtained by the determination of the formation constants of the species and by the description of their structure. The aim of this work is also to obtain a selective complexation of lanthanides(III) towards actinides(III), because this aim presents a great interest in the reprocessing of radioactive wastes. The complexation studies have been followed by potentiometry, NMR, UV-visible spectroscopy and circular dichroism. The first mixtures studied are the couples: lanthanide(III)-gluconic acid (LH). The complexes system they formed has been described and the structures have been specified; a strong complexation has been revealed. The MLH -2 specie induces a selectivity between the lanthanides(III) equivalent to those obtained with EDTA and its uncharged character allows to consider the use of gluconic acid as extractant. The use of ligands as glucosaminic acid or glucamine slows the beginning of the complexation until pH= 6-7. The neutral specie MLH -2 is formed too. In order to use the complexing properties of gluconic acid and its selective character towards lanthanides(III), the synthesis of molecules derived containing a long alkyl chain with a hydrophobic character has been carried out for using them as extracting agents. An original method of the preparation of tartramides is presented. This preparation consists of an amidation of one of the carboxylic functions of the tartaric acid by a fatty amine. These molecules, surface-active, complex the lanthanides(III) and extract them in an organic phase using the tri-n-butyl phosphate as co-extractant. (O.M.)

  3. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule Matters - Dinitrogen. A G Samuelson J Jabadurai. Volume 16 Issue 12 ... Author Affiliations. A G Samuelson1 J Jabadurai1. Department of Inroganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  4. Molecule Matters

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. Molecule Matters - A Chromium Compound with a Quintuple Bond. K C Kumara Swamy. Feature Article Volume 11 Issue 9 September 2006 pp 72-75. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Determination of bromide in aqueous solutions via the TlBr molecule using high-resolution continuum source graphite furnace molecular absorption spectrometry

    Science.gov (United States)

    Cacho, Frantisek; Machynak, Lubomir; Nemecek, Martin; Beinrohr, Ernest

    2018-06-01

    The paper describes the determination of bromide by evaluating the molecular absorption of thallium mono-bromide (TlBr) at the rotational line at 342.9815 nm by making use a high-resolution continuum source graphite furnace atomic absorption spectrometer. The effects of variables such as the wavelength, graphite furnace program, amount of Tl and the use of a modifier were investigated and optimized. Various chemical modifiers have been studied, such as Pd, Mg, Ag and a mixture of Pd/Mg. It was found that best results were obtained by using Ag which prevents losses of bromide during pyrolysis step through precipitation of bromide as AgBr. In this way, a maximum pyrolysis temperature of 400 °C could be used. The optimum molecule forming temperature was found to be 900 °C. Bromide concentrations in various water samples (CRM, bottled drinking water and tap water) were determined. The quantification was made by both linear calibration and standard addition techniques. The results were matched well those of the reference method. The calibration curve was linear in the range between 1 and 1000 ng Br with a correlation coefficient R = 0.999. The limit of detection and characteristic mass of the method were 0.3 ng and 4.4 ng of Br.

  6. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine

    International Nuclear Information System (INIS)

    Riviere, Ch.

    2000-01-01

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  7. Effects of solubilization of short and medium-chain molecules in the self-assembly of two amphiphilic drugs in solution

    International Nuclear Information System (INIS)

    Barbosa, Silvia; Cheema, Mohammad Arif; Siddiq, Mohammad; Taboada, Pablo; Mosquera, Victor

    2009-01-01

    The effect of short and medium chain length alcohols ethanol, propanol, and butanol on the thermodynamic properties of aqueous solutions of the ionic amphiphilic antidepressants imipramine and clomipramine hydrochlorides has been investigated at T = 293 K. Critical concentrations of the drugs were obtained from ultrasound velocity measurements. Experimental results have shown a strong dependence of the ultrasound velocity with the alcohol concentration and chain length. Differences in the aggregate properties of both amphiphiles arise from the presence of the extra Cl - substituent on the ring system of clomipramine. Density and ultrasound measurements have been used to obtain the apparent molar volumes, V φ , and isentropic apparent molar compressibilities, K φ(S) , for the aqueous drug/water-alcohol solutions. The distribution coefficient of the amount solubilized between water and the aggregates, K, has been determined using an indirect method based on the pseudo-phase model by using apparent molar volume values. This method allows the calculation of the distribution coefficients at concentrations below saturation. The standard molar Gibbs free energy change on transfer from the aqueous to the micellar, ΔG 0 , phase was calculated from the partition coefficient. The results have highlighted the structural differences between both amphiphiles

  8. Relationship between solute permeability and osmotic remediability in a galactose-negative strain of Saccharomyces cerevisiae.

    Science.gov (United States)

    Bassel, J; Douglas, H C

    1970-11-01

    An osmotic remedial allele, gal 7-1, in the galactose pathway of Saccharomyces cerevisiae responds to either penetrating (ethylene glycol and diethylene glycol) or nonpenetrating (KCl, NaCl, and sorbitol) solutes in the growth medium. Extracts from cells grown under restrictive conditions gave no increase in enzyme activity (gal-1-phosphate, uridylyl transferase) when exposed to the penetrating solutes; thus protein synthesis or possibly polymer assembly is proposed as the critical step remedied by the addition of the solutes.

  9. Proteins involved in difference of sorbitol fermentation rates of the toxigenic and nontoxigenic Vibrio cholerae El Tor strains revealed by comparative proteome analysis

    Science.gov (United States)

    2009-01-01

    Background The nontoxigenic V. cholerae El Tor strains ferment sorbitol faster than the toxigenic strains, hence fast-fermenting and slow-fermenting strains are defined by sorbitol fermentation test. This test has been used for more than 40 years in cholera surveillance and strain analysis in China. Understanding of the mechanisms of sorbitol metabolism of the toxigenic and nontoxigenic strains may help to explore the genome and metabolism divergence in these strains. Here we used comparative proteomic analysis to find the proteins which may be involved in such metabolic difference. Results We found the production of formate and lactic acid in the sorbitol fermentation medium of the nontoxigenic strain was earlier than of the toxigenic strain. We compared the protein expression profiles of the toxigenic strain N16961 and nontoxigenic strain JS32 cultured in sorbitol fermentation medium, by using fructose fermentation medium as the control. Seventy-three differential protein spots were found and further identified by MALDI-MS. The difference of product of fructose-specific IIA/FPR component gene and mannitol-1-P dehydrogenase, may be involved in the difference of sorbitol transportation and dehydrogenation in the sorbitol fast- and slow-fermenting strains. The difference of the relative transcription levels of pyruvate formate-lyase to pyruvate dehydrogenase between the toxigenic and nontoxigenic strains may be also responsible for the time and ability difference of formate production between these strains. Conclusion Multiple factors involved in different metabolism steps may affect the sorbitol fermentation in the toxigenic and nontoxigenic strains of V. cholerae El Tor. PMID:19589152

  10. Blending of soluble corn fiber with pullulan, sorbitol, or fructose attenuates glycemic and insulinemic responses in the dog and affects hydrolytic digestion in vitro.

    Science.gov (United States)

    de Godoy, M R C; Knapp, B K; Bauer, L L; Swanson, K S; Fahey, G C

    2013-08-01

    The objective of these experiments was to measure in vitro hydrolytic digestion and glycemic and insulinemic responses of select carbohydrate blends, all containing the novel carbohydrate soluble corn fiber (SCF). Two SCF that varied in their method of production were used to formulate the carbohydrate blends. One set of blends contained a SCF that was spray dried (SCFsd) and then blended with different amounts of either pullulan, sorbitol, or fructose. The other set of blends contained a SCF produced using longer evaporation time (SCF) and then blended with different ratios of pullulan, sorbitol, and fructose. Free sugar concentrations found in the individual SCFsd and SCF substrates were low but varied. Spray-dried soluble corn fiber had a reduced free sugar concentration compared with SCF (2.8 vs. 14.2%). Glucose was the main free sugar found in both SCFsd and SCF but at different concentrations (2.7 vs. 12.7%, respectively). The majority of the SCFsd blends were completely hydrolyzed to their monosaccharide components. Glucose accounted for most of the hydrolyzed monosaccharides for SCFsd and all the SCFsd blends. Hydrolyzed monosaccharide concentrations for the SCF:pullulan:sorbitol:fructose blends followed similar trends to the SCFsd blends where greater percentages of fructose and sorbitol resulted in decreased (P sorbitol. Total released monosaccharides were high in SCFsd blends containing either 50% fructose or sorbitol, but the combination resulted in reduced concentrations of glucose released (P sorbitol:fructose blends also had intermediate to high released monosaccharides as a result of in vitro hydrolytic digestion. All SCF blends resulted in decreased glycemic and insulinemic responses compared with the maltodextrin control (P sorbitol in the blends had the greatest impact on glycemic and insulinemic responses, even at concentrations as low as 5% of the blends. Overall, SCF and their blends may prove beneficial as components of low glycemic

  11. Labelled molecules, modern research implements

    International Nuclear Information System (INIS)

    Pichat, L.; Langourieux, Y.

    1974-01-01

    Details of the synthesis of carbon 14- and tritium-labelled molecules are examined. Although the methods used are those of classical organic chemistry the preparation of carbon 14-labelled molecules differs in some respects, most noticeably in the use of 14 CO 2 which requires very special handling techniques. For the tritium labelling of organic molecules the methods are somewhat different, very often involving exchange reactions. The following are described in turn: the so-called Wilzbach exchange method; exchange by catalysis in solution; catalytic hydrogenation with tritium; reductions with borotritides. Some applications of labelled molecules in organic chemistry, biochemistry and pharmacology are listed [fr

  12. Putative metabolic pathway of mannitol and sorbitol and in sugarcane Provável via metabólica de manitol e sorbitol em cana-de-açúcar

    Directory of Open Access Journals (Sweden)

    Celso Luís Marino

    2003-12-01

    Full Text Available Until the mid 1950s, boron was believed to play an important role in the transport of sugars in plants. However, boron actually depends on sugar alcohols to be taken up by the plant. In some cases, the main sugars involved in this process are sorbitol and mannitol which form stable complexes with boron. In this study, the sequences of the SugarCane EST Genome Project (SUCEST database were searched for enzymes involved in the metabolism of these sugars by comparing them with enzymes from other organisms. Eighteen contigs from sugarcane (Saccharum sp. presented high similarity with 11 enzymes involved in the putative biosynthetic pathway of sorbitol and mannitol from fructose in sugarcane. Seven of these contigs had high homology with sequences deposited in GenBank.Até meados da década de 50 acreditava-se que o boro tinha uma importante função no transporte de açúcares em plantas. Na verdade, o boro depende de açúcares álcoois para serem mobilizados dentro da planta. Em alguns organismos os principais açúcares envolvidos neste processo são o sorbitol e o manitol, que formam complexos estáveis com o micronutriente. O objetivo deste estudo foi procurar seqüências no banco de dados SugarCane EST Genome Project (SUCEST que codificam enzimas participantes na via metabólica destes açúcares através da comparação de enzimas de outros organismos. Dezoito "contigs" de cana-de-açúcar (Saccharum sp. apresentaram similaridade com onze seqüências de enzimas que compõem a provável via metabólica de sorbitol e manitol a partir de frutose. Destes "contigs", sete apresentaram uma alta similaridade entre as seqüências depositadas no GenBank.

  13. Neural Network Molecule: a Solution of the Inverse Biometry Problem through Software Support of Quantum Superposition on Outputs of the Network of Artificial Neurons

    Directory of Open Access Journals (Sweden)

    Vladimir I. Volchikhin

    2017-12-01

    Full Text Available Introduction: The aim of the study is to accelerate the solution of neural network biometrics inverse problem on an ordinary desktop computer. Materials and Methods: To speed up the calculations, the artificial neural network is introduced into the dynamic mode of “jittering” of the states of all 256 output bits. At the same time, too many output states of the neural network are logarithmically folded by transitioning to the Hamming distance space between the code of the image “Own” and the codes of the images “Alien”. From the database of images of “Alien” 2.5 % of the most similar images are selected. In the next generation, 97.5 % of the discarded images are restored with GOST R 52633.2-2010 procedures by crossing parent images and obtaining descendant images from them. Results: Over a period of about 10 minutes, 60 generations of directed search for the solution of the inverse problem can be realized that allows inversing matrices of neural network functionals of dimension 416 inputs to 256 outputs with restoration of up to 97 % information on unknown biometric parameters of the image “Own”. Discussion and Conclusions: Supporting for 10 minutes of computer time the 256 qubit quantum superposition allows on a conventional computer to bypass the actual infinity of analyzed states in 5050 (50 to 50 times more than the same computer could process realizing the usual calculations. The increase in the length of the supported quantum superposition by 40 qubits is equivalent to increasing the processor clock speed by about a billion times. It is for this reason that it is more profitable to increase the number of quantum superpositions supported by the software emulator in comparison with the creation of a more powerful processor.

  14. Conversion of biomass-derived sorbitol to glycols over carbon-materials supported Ru-based catalysts

    Science.gov (United States)

    Guo, Xingcui; Guan, Jing; Li, Bin; Wang, Xicheng; Mu, Xindong; Liu, Huizhou

    2015-11-01

    Ruthenium (Ru) supported on activated carbon (AC) and carbon nanotubes (CNTs) was carried out in the hydrogenolysis of sorbitol to ethylene glycol (EG) and 1,2-propanediol (1,2-PD) under the promotion of tungsten (WOx) species and different bases. Their catalytic activities and glycols selectivities strongly depended on the support properties and location of Ru on CNTs, owning to the altered metal-support interactions and electronic state of ruthenium. Ru located outside of the tubes showed excellent catalytic performance than those encapsulated inside the nanotubes. Additionally, the introduction of WOx into Ru/CNTs significantly improved the hydrogenolysis activities, and a complete conversion of sorbitol with up to 60.2% 1,2-PD and EG yields was obtained on RuWOx/CNTs catalyst upon addition of Ca(OH)2. Stability study showed that this catalyst was highly stable against leaching and poisoning and could be recycled several times.

  15. Intracellular trehalose and sorbitol synergistically promoting cell viability of a biocontrol yeast, Pichia anomala, for aflatoxin reduction.

    Science.gov (United States)

    Hua, Sui Sheng T; Hernlem, Bradley J; Yokoyama, Wallace; Sarreal, Siov Bouy L

    2015-05-01

    Pichia anomala (Wickerhamomyces anomalus) WRL-076 was discovered by a visual screening bioassay for its antagonism against Aspergillus flavus. The yeast was shown to significantly inhibit aflatoxin production and the growth of A. flavus. P. anomala is a potential biocontrol agent for reduction of aflatoxin in the food chain. Maintaining the viability of biocontrol agents in formulated products is a great challenge for commercial applications. Four media, NYG, NYGS, NYGT and NYGST are described which support good growth of yeast cells and were tested as storage formulations. Post growth supplement of 5 % trehalose to NYGST resulted in 83 % viable yeast cells after 12 months in cold storage. Intracellular sorbitol and trehalose concentrations were determined by HPLC analysis at the beginning of the storage and at the end of 12 month. Correlation of cell viability to both trehalose and sorbitol suggested a synergistic effect. Bonferroni (Dunn) t Test, Tukey's Studentized Range (HSD) Test and Duncan's Multiple Range Test, all showed that yeast cell viability in samples with both intracellular trehalose and sorbitol were significantly higher than those with either or none, at a 95 % confidence level. DiBAC4(5) and CFDA-AM were used as the membrane integrity fluorescent stains to create a two-color vital staining scheme with red and green fluorescence, respectively. Yeast cells stored in formulations NYG and NYGS with no detectable trehalose, displayed mostly red fluorescence. Yeast cells in NYGST+5T showed mostly green fluorescence.

  16. Freeze-dried snake antivenoms formulated with sorbitol, sucrose or mannitol: comparison of their stability in an accelerated test.

    Science.gov (United States)

    Herrera, María; Tattini, Virgilio; Pitombo, Ronaldo N M; Gutiérrez, José María; Borgognoni, Camila; Vega-Baudrit, José; Solera, Federico; Cerdas, Maykel; Segura, Alvaro; Villalta, Mauren; Vargas, Mariángela; León, Guillermo

    2014-11-01

    Freeze-drying is used to improve the long term stability of pharmaceutical proteins. Sugars and polyols have been successfully used in the stabilization of proteins. However, their use in the development of freeze-dried antivenoms has not been documented. In this work, whole IgG snake antivenom, purified from equine plasma, was formulated with different concentrations of sorbitol, sucrose or mannitol. The glass transition temperatures of frozen formulations, determined by Differential Scanning Calorimetry (DSC), ranged between -13.5 °C and -41 °C. In order to evaluate the effectiveness of the different stabilizers, the freeze-dried samples were subjected to an accelerated stability test at 40 ± 2 °C and 75 ± 5% relative humidity. After six months of storage at 40 °C, all the formulations presented the same residual humidity, but significant differences were observed in turbidity, reconstitution time and electrophoretic pattern. Moreover, all formulations, except antivenoms freeze-dried with mannitol, exhibited the same potency for the neutralization of lethal effect of Bothrops asper venom. The 5% (w:v) sucrose formulation exhibited the best stability among the samples tested, while mannitol and sorbitol formulations turned brown. These results suggest that sucrose is a better stabilizer than mannitol and sorbitol in the formulation of freeze-dried antivenoms under the studied conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Molecular motions in sucrose-PVP and sucrose-sorbitol dispersions-II. Implications of annealing on secondary relaxations.

    Science.gov (United States)

    Bhattacharya, Sisir; Bhardwaj, Sunny P; Suryanarayanan, Raj

    2014-10-01

    To determine the effect of annealing on the two secondary relaxations in amorphous sucrose and in sucrose solid dispersions. Sucrose was co-lyophilized with either PVP or sorbitol, annealed for different time periods and analyzed by dielectric spectroscopy. In an earlier investigation, we had documented the effect of PVP and sorbitol on the primary and the two secondary relaxations in amorphous sucrose solid dispersions (1). Here we investigated the effect of annealing on local motions, both in amorphous sucrose and in the dispersions. The average relaxation time of the local motion (irrespective of origin) in sucrose, decreased upon annealing. However, the heterogeneity in relaxation time distribution as well as the dielectric strength decreased only for β1- (the slower relaxation) but not for β2-relaxations. The effect of annealing on β2-relaxation times was neutralized by sorbitol while PVP negated the effect of annealing on both β1- and β2-relaxations. An increase in local mobility of sucrose brought about by annealing could be negated with an additive.

  18. Simultaneous determination of glucose, fructose, sucrose and sorbitol in the leaf and fruit peel of different apple cultivars by the HPLC-RI optimized method.

    Science.gov (United States)

    Filip, Miuţa; Vlassa, Mihaela; Coman, Virginia; Halmagyi, Adela

    2016-05-15

    A high performance liquid chromatography method with refractive index detection (HPLC-RI), for simultaneous determination of glucose, fructose, sucrose and sorbitol in leaf and/or apple peel samples from nine apple (Malus domestica Borkh.) cultivars and rootstocks, originating from a germplasm collection, has been developed and validated. Box-Behnken design of response surface methodology was applied for the method optimization. The Carbosep Coregel 87H3 column was used under the optimum conditions predicted: mobile phase of H2SO4 0.005 mol L(-1) solution, flow rate of 0.3 mL min(-1) and column temperature of 35°C. The method was validated for linearity (R(2)>0.99), limits of detection (2.67-4.83 μg mL(-1)) and quantification (8.9-16.1 μg mL(-1)), precision (%RSD<5.05) and recovery (93.94-103.06%) and satisfactory results obtained. The sugars content varied across micropropagated plants in vitro, plants regenerated after cryostorage, growing trees in vivo, and fruit peel. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. PRODUKSI ANTIBIOTIKA OLEH Bacillus subtilis M10 DALAM MEDIA UREA-SORBITOL

    Directory of Open Access Journals (Sweden)

    Supartono Supartono

    2012-04-01

    Full Text Available PRODUCTION OF ANTIBIOTICS BY Bacillus subtilis M10 IN UREA-SORBITOL MEDIUM. Infection diseases still become the main health problems that suffered by people in Indonesia. Besides, there were many pathogen bacteria found to be resistant to the some antibiotics. Therefore, the efforts to get a new antibiotic require to be done continuously. A new local strain of Bacillus subtilis BAC4 has been known producing an antibiotic that inhibit Serratia marcescens ATCC 27117 growth. To make efficient the local strain, mutation on Bacillus subtilis BAC4 was done by using acridine orange and a mutant cell of Bacillus subtilis M10 that overproduction for producing antibiotic was obtained. Nevertheless, the production kinetics of antibiotic by this mutant has not been reported. The objective of this research was to study the production kinetics of antibiotic by Bacillus subtilis M10 mutant. The production of antibiotic was conducted using batch fermentation and antibiotic assay was performed with agar absorption method using Serratia marcescens ATCC 27117 as bacteria assay. Research result provided that Bacillus subtilis M10 mutant with overproduction of antibiotic produced an antibiotic since 8th hour’s fermentation and optimum of it production was at 14th hours after inoculation.  Penyakit infeksi masih menjadi masalah yang utama diderita oleh masyarakat Indonesia. Di samping itu, banyak bakteri patogen yang ditemukan resisten terhadap beberapa antibiotika. Oleh karena itu, upaya-upaya untuk mendapatkan antibiotika baru perlu dilakukan secara terus-menerus. Suatu galur lokal baru Bacillus subtilis BAC4 teridentifikasi memproduksi senyawa antibiotika yang menghambat pertumbuhan Serratia marcescens ATCC27117. Untuk memberdayakan galur tersebut, terhadap Bacillus subtilis BAC4 dilakukan mutasi dengan larutan akridin oranye dan diperoleh mutan Bacillus subtilis M10 yang memproduksi antibiotika berlebihan. Namun, kinetika produksi antibiotika oleh Bacillus

  20. Study of two examples of non linear interaction of a laser wave with matter: laser-induced damage of dielectrics and non linear optical properties of organometallic molecules in solution

    International Nuclear Information System (INIS)

    Gaudry, Jean-Baptiste

    2000-01-01

    This research thesis reports the study of two mechanisms of non linear interaction of a laser wave with matter. More particularly, it reports the experimental investigation of non linear optical properties of organometallic molecules in solution, as well as the damage of perfect silica under laser irradiation by using simulation codes. As far as optical properties are concerned, the author highlights the influence of the electronic configuration of the metal present in the organometallic compound, and the influence of the ligand on the second-order non-linear response. As far as the simulation is concerned, some experimental results have been reproduced. This work can be useful for the investigation of the extrinsic damage of imperfect materials, and for the design of experiments of transient measurements of excited silica [fr

  1. Sorbitol-based osmotic diarrhea: possible causes and mechanism of prevention investigated in rats.

    Science.gov (United States)

    Islam, Md Shahidul; Sakaguchi, Ei

    2006-12-21

    To study the possible causes of sorbitol (S)-based diarrhea and its mechanism of reduction by rice gruel (RG) in cecectomized rats. S was dissolved either in distilled water or in RG (50 g/L) and ingested as a single oral dose (1.2 g/kg body mass, containing 0.5 g/L phenol red as a recovery marker) by S (control) and S + RG groups (n = 7), respectively. This dose is over the laxative dose for humans. Animals were sacrificed exactly 1 h after dose ingestion, without any access to drinking water. The whole gastro-intestinal tract was divided into seven segments and sampled to analyze the S and marker remaining in its contents. Gastric-emptying and intestinal transit were comparatively slower in the S + RG group. Also, the S absorption index in the 3(rd) and last quarter of the small intestine (24.85 +/- 18.88% vs 0.0 +/- 0.0% and 39.09 +/- 32.75% vs 0.0 +/- 0.0%, respectively, P osmotic diarrhea. Where RG enhanced the absorption of S through passive diffusion, the degree of diarrhea was reduced in cecectomized rats.

  2. Colitis induced by sodium polystyrene sulfonate in sorbitol: A report of six cases.

    Science.gov (United States)

    Jacob, Sheba S K; Parameswaran, Ashok; Parameswaran, Sarojini Ashok; Dhus, Ubal

    2016-03-01

    Drug-related injury has been noted in virtually all organ systems, and recognition of the patterns of injury associated with medication enables modification of treatment and reduces the morbidity associated with the side effects of drugs. With the large number of new drugs being developed, documentation of the morphology of the changes seen as an adverse effect becomes important to characterize the pattern of injury. The pathologist is often the first to identify these abnormalities and correlate them with a particular drug. Kayexalate or sodium polystyrene sulfonate (SPS), a linear polymer derived from polystyrene containing sulfonic acid and sulfonate functional groups is used to treat hyperkalemia. It is usually administered with an osmotic laxative sorbitol orally or as retention enema. This combination has been implicated in causing damage to different parts of the gastrointestinal (GI) tract especially the colon and causes an established pattern of injury, recognizable by the presence of characteristic crystals, is presented to create a greater awareness of the Kayexalate colitis. This entity should be included in the differential diagnosis of lower GI mucosal injury in a setting of uremia and hyperkalemia.

  3. Improving the performance of solution-processed organic solar cells by incorporating small molecule acceptors into a ternary bulk heterojunction based on DH6T:Mq3:PCBM (M = Ga, Al)

    International Nuclear Information System (INIS)

    Muhammad, Fahmi F.; Yahya, Mohd Yazid; Sulaiman, Khaulah

    2017-01-01

    Improvement in the overall performance of solution-processed organic solar cells based on a ternary heterostructure was realized by means of incorporating small molecules of tris(8-hydroxyquinoline) gallium (Gaq3) or Alq3 electron acceptors. The donor host polymer was α,ω-dihexyl-sexithiophene (DH6T), while the ultimate acceptor was fullerene (PC 61 BM). The results showed that short circuit current (I Sc ), open circuit voltage (V oc ), and fill factor (FF) of the devices were pronouncedly enhanced by the inclusion of Gaq3 or Alq3. The maximum output power and conversion efficiency of the ternary devices were increased by an order of 5.8 times compared to that of the control devices. These improvements were ascribed to the broadened light absorption, energy levels alignment between the donor-acceptor components, a balanced charge transfer, and increased crystallinity of the devices active layer. The results were ascertained and analyzed by means of UV–Vis, PL, XRD, IV and TEM investigations. - Highlights: • Ternary solution-processed OSCs including Gaq3 and Alq3 acceptors were realized. • The power and efficiency of the devices were increased by an order of 5.8. • Broadened absorption and improved crystallinity were achieved for the active layers.

  4. Improving the performance of solution-processed organic solar cells by incorporating small molecule acceptors into a ternary bulk heterojunction based on DH6T:Mq3:PCBM (M = Ga, Al)

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Fahmi F. [Center for Composites, Institute for Vehicle Systems & Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Soft Materials & Devices Lab, Department of Physics, Faculty of Science & Health, Koya University, Koya, Kurdistan Region (Iraq); Development Center for Research and Training, University of Human Development, Sulaimani, Kurdistan Region (Iraq); Yahya, Mohd Yazid, E-mail: yazidyahya@utm.my [Center for Composites, Institute for Vehicle Systems & Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Sulaiman, Khaulah [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2017-02-15

    Improvement in the overall performance of solution-processed organic solar cells based on a ternary heterostructure was realized by means of incorporating small molecules of tris(8-hydroxyquinoline) gallium (Gaq3) or Alq3 electron acceptors. The donor host polymer was α,ω-dihexyl-sexithiophene (DH6T), while the ultimate acceptor was fullerene (PC{sub 61}BM). The results showed that short circuit current (I{sub Sc}), open circuit voltage (V{sub oc}), and fill factor (FF) of the devices were pronouncedly enhanced by the inclusion of Gaq3 or Alq3. The maximum output power and conversion efficiency of the ternary devices were increased by an order of 5.8 times compared to that of the control devices. These improvements were ascribed to the broadened light absorption, energy levels alignment between the donor-acceptor components, a balanced charge transfer, and increased crystallinity of the devices active layer. The results were ascertained and analyzed by means of UV–Vis, PL, XRD, IV and TEM investigations. - Highlights: • Ternary solution-processed OSCs including Gaq3 and Alq3 acceptors were realized. • The power and efficiency of the devices were increased by an order of 5.8. • Broadened absorption and improved crystallinity were achieved for the active layers.

  5. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan. Feature Article Volume 14 Issue 12 December 2009 pp 1210-1222 ...

  6. Enzyme Molecules in Solitary Confinement

    Directory of Open Access Journals (Sweden)

    Raphaela B. Liebherr

    2014-09-01

    Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  7. Effects of dormancy progression and low-temperature response on changes in the sorbitol concentration in xylem sap of Japanese pear during winter season.

    Science.gov (United States)

    Ito, Akiko; Sugiura, Toshihiko; Sakamoto, Daisuke; Moriguchi, Takaya

    2013-04-01

    In order to elucidate which physiological event(s) are involved in the seasonal changes of carbohydrate dynamics during winter, we examined the effects of different low temperatures on the carbohydrate concentrations of Japanese pear (Pyrus pyrifolia (Burm.) Nakai). For four winter seasons, large increases in the sorbitol concentration of shoot xylem sap occurred during mid- to late December, possibly due to the endodormancy completion and low-temperature responses. When trees were kept at 15 °C from 3 November to 3 December in order to postpone the initiation and completion of chilling accumulation that would break endodormancy, sorbitol accumulation in xylem sap was always higher from trees with sufficient chilling accumulation than from trees that received insufficient chilling. However, an additional increase in xylem sap sorbitol occurred around late December in trees regardless of whether their chilling accumulation naturally progressed or was postponed. To examine different temperature effects more closely, we compared the carbohydrate concentrations of trees subjected to either 6 or 0 °C treatment. The sorbitol concentration in xylem sap tremendously increased at 0 °C treatment compared with 6 °C treatment. However, an additional increase in xylem sap sorbitol occurred at both the temperatures when sufficient chilling accumulated with a peak coinciding with the peak expression in shoots of the sorbitol transporter gene (PpSOT2). Interestingly, the total carbohydrate concentration of shoots tremendously increased with exposure to 0 °C compared with exposure to 6 °C, but was not affected by the amount of accumulated chilling. Instead, as chilling accumulated the ratio of sorbitol to total soluble sugars in shoots increased. We presumed that carbohydrates in the shoot tissues may be converted to sorbitol and loaded into the xylem sap so that the sorbitol accumulation patterns were synchronized with the progression of dormancy, whereas the total

  8. Vancomycin-resistant Enterococcus faecium bacteraemia as a complication of Kayexalate (sodium polystyrene sulfonate, SPS) in sorbitol-induced ischaemic colitis.

    Science.gov (United States)

    Cerrud-Rodriguez, Roberto Christian; Alcaraz-Alvarez, Diego; Chiong, Brian Bobby; Ahmed, Abdurhman

    2017-11-09

    We present the case report of an 80-year-old woman with chronic kidney disease stage G5 admitted to the hospital with fluid overload and hyperkalaemia. Sodium polystyrene sulfonate (SPS, Kayexalate) in sorbitol suspension was given orally to treat her hyperkalaemia, which precipitated an episode of SPS in sorbitol-induced ischaemic colitis with the subsequent complication of vancomycin-resistant Enterococcus (VRE) bacteraemia. SPS (Kayexalate) in sorbitol suspension has been implicated in the development of intestinal necrosis. Sorbitol, which is added as a cathartic agent to decrease the chance of faecal impaction, may be primarily responsible through several proposed mechanisms. The gold standard of diagnosis is the presence of SPS crystals in the colon biopsy. On a MEDLINE search, no previous reports of a VRE bacteraemia as a complication of biopsy-confirmed SPS in sorbitol ischaemic colitis were found. To the best of our knowledge, ours would be the first such case ever reported. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. OMG: Open Molecule Generator.

    Science.gov (United States)

    Peironcely, Julio E; Rojas-Chertó, Miguel; Fichera, Davide; Reijmers, Theo; Coulier, Leon; Faulon, Jean-Loup; Hankemeier, Thomas

    2012-09-17

    Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG), which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  10. OMG: Open Molecule Generator

    Directory of Open Access Journals (Sweden)

    Peironcely Julio E

    2012-09-01

    Full Text Available Abstract Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG, which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck.

  11. Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

    International Nuclear Information System (INIS)

    Blodgett, M.B.; Ziemer, S.P.; Brown, B.R.; Niederhauser, T.L.; Woolley, E.M.

    2007-01-01

    Apparent molar volumes V φ were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C p,φ of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg -1 ) of the solutions were in the range (0.02 ≤ m ≤ 3.2) for adonitol, (0.02 ≤ m ≤ 0.15) for dulcitol, (0.02 ≤ m ≤ 5.0) for glycerol, (0.02 ≤ m ≤ 3.0) for meso-erythritol, (0.02 ≤ m ≤ 0.5) for myo-inositol, (0.02 ≤ m ≤ 2.0) for D-sorbitol, and (0.02 ≤ m ≤ 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V φ and C p,φ for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available

  12. Apparent molar volumes and apparent molar heat capacities of aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Blodgett, M.B. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Ziemer, S.P. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Brown, B.R. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Niederhauser, T.L. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States); Woolley, E.M. [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84602-5700 (United States)]. E-mail: earl_woolley@byu.edu

    2007-04-15

    Apparent molar volumes V {sub {phi}} were determined for aqueous adonitol, dulcitol, glycerol, meso-erythritol, myo-inositol, D-sorbitol, and xylitol at temperatures from (278.15 to 368.15) K and at the pressure 0.35 MPa, and apparent molar heat capacities C {sub p,{phi}} of the same solutions were determined at temperatures from (278.15 to 363.15) K at the same pressure. Molalities m/(mol . kg{sup -1}) of the solutions were in the range (0.02 {<=} m {<=} 3.2) for adonitol, (0.02 {<=} m {<=} 0.15) for dulcitol, (0.02 {<=} m {<=} 5.0) for glycerol, (0.02 {<=} m {<=} 3.0) for meso-erythritol, (0.02 {<=} m {<=} 0.5) for myo-inositol, (0.02 {<=} m {<=} 2.0) for D-sorbitol, and (0.02 {<=} m {<=} 2.7) for xylitol. A vibrating tube densimeter was used to obtain solution densities and a fixed-cell temperature scanning calorimeter was used to obtain heat capacities. Values of V {sub {phi}} and C {sub p,{phi}} for these sugar alcohols are discussed relative to one another and compared to values from the literature, where available.

  13. Effect of sorbitol, single, and multidose activated charcoal administration on carprofen absorption following experimental overdose in dogs.

    Science.gov (United States)

    Koenigshof, Amy M; Beal, Matthew W; Poppenga, Robert H; Jutkowitz, L Ari

    2015-01-01

    To compare the effectiveness of single dose activated charcoal, single dose activated charcoal with sorbitol, and multidose activated charcoal in reducing plasma carprofen concentrations following experimental overdose in dogs. Randomized, four period cross-over study. University research setting. Eight healthy Beagles. A 120 mg/kg of carprofen was administered orally to each dog followed by either (i) a single 2 g/kg activated charcoal administration 1 hour following carprofen ingestion (AC); (ii) 2 g/kg activated charcoal with 3.84 g/kg sorbitol 1 hour following carprofen ingestion (ACS); (iii) 2 g/kg activated charcoal 1 hour after carprofen ingestion and repeated every 6 hours for a total of 4 doses (MD); (iv) no treatment (control). Plasma carprofen concentrations were obtained over a 36-hour period following carprofen ingestion for each protocol. Pharmacokinetic modeling was performed and time versus concentration, area under the curve, maximum plasma concentration, time to maximum concentration, and elimination half-life were calculated and compared among the groups using ANOVA followed by Tukey's multiple comparisons test. Activated charcoal, activated charcoal with sorbitol (ACS), and multiple-dose activated charcoal (MD) significantly reduced the area under the curve compared to the control group. AC and MD significantly reduced the maximum concentration when compared to the control group. MD significantly reduced elimination half-life when compared to ACS and the control group. There were no other significant differences among the treatment groups. Activated charcoal and ACS are as effective as MD in reducing serum carprofen concentrations following experimental overdose in dogs. Prospective studies are warranted to evaluate the effectiveness of AC, ACS, and MD in the clinical setting. © Veterinary Emergency and Critical Care Society 2015.

  14. Conversion of cellulose and cellobiose into sorbitol catalyzed by ruthenium supported on a polyoxometalate/metal-organic framework hybrid.

    Science.gov (United States)

    Chen, Jinzhu; Wang, Shengpei; Huang, Jing; Chen, Limin; Ma, Longlong; Huang, Xing

    2013-08-01

    Cellulose and cellobiose were selectively converted into sorbitol over water-tolerant phosphotungstic acid (PTA)/metal- organic-framework-hybrid-supported ruthenium catalysts, Ru-PTA/MIL-100(Cr), under aqueous hydrogenation conditions. The goal was to investigate the relationship between the acid/metal balance of bifunctional catalysts Ru-PTA/MIL-100(Cr) and their performance in the catalytic conversion of cellulose and cellobiose into sugar alcohols. The control of the amount and strength of acid sites in the supported PTA/MIL-100(Cr) was achieved through the effective control of encapsulated-PTA loading in MIL-100(Cr). This design and preparation method led to an appropriately balanced Ru-PTA/MIL-100(Cr) in terms of Ru dispersion and hydrogenation capacity on the one hand, and acid site density of PTA/MIL-100(Cr) (responsible for acid-catalyzed hydrolysis) on the other hand. The ratio of acid site density to the number of Ru surface atoms (nA /nRu ) of Ru-PTA/MIL-100(Cr) was used to monitor the balance between hydrogenation and hydrolysis functions; the optimum balance between the two catalytic functions, that is, 8.84sorbitol of 57.9% at complete conversion of cellulose, and 97.1% yield in hexitols with a selectivity for sorbitol of 95.1% at complete conversion of cellobiose) were obtained using a Ru-PTA/MIL-100(Cr) catalyst with loadings of 3.2 wt % for Ru and 16.7 wt % for PTA. This research thus opens new perspectives for the rational design of acid/metal bifunctional catalysts for biomass conversion. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Photosystem I shows a higher tolerance to sorbitol-induced osmotic stress than photosystem II in the intertidal macro-algae Ulva prolifera (Chlorophyta).

    Science.gov (United States)

    Gao, Shan; Zheng, Zhenbing; Gu, Wenhui; Xie, Xiujun; Huan, Li; Pan, Guanghua; Wang, Guangce

    2014-10-01

    The photosynthetic performance of the desiccation-tolerant, intertidal macro-algae Ulva prolifera was significantly affected by sorbitol-induced osmotic stress. Our results showed that photosynthetic activity decreased significantly with increases in sorbitol concentration. Although the partial activity of both photosystem I (PS I) and photosystem II (PS II) was able to recover after 30 min of rehydration, the activity of PS II decreased more rapidly than PS I. At 4 M sorbitol concentration, the activity of PS II was almost 0 while that of PS I was still at about one third of normal levels. Following prolonged treatment with 1 and 2 M sorbitol, the activity of PS I and PS II decreased slowly, suggesting that the effects of moderate concentrations of sorbitol on PS I and PS II were gradual. Interestingly, an increase in non-photochemical quenching occurred under these conditions in response to moderate osmotic stress, whereas it declined significantly under severe osmotic stress. These results suggest that photoprotection in U. prolifera could also be induced by moderate osmotic stress. In addition, the oxidation of PS I was significantly affected by osmotic stress. P700(+) in the thalli treated with high concentrations of sorbitol could still be reduced, as PS II was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), but it could not be fully oxidized. This observation may be caused by the higher quantum yield of non-photochemical energy dissipation in PS I due to acceptor-side limitation (Y(NA)) during rehydration in seawater containing DCMU. © 2014 Scandinavian Plant Physiology Society.

  16. Utilization starch of jackfruit seed (Artocarpus heterophyllus) as raw material for bioplastics manufacturing using sorbitol as plasticizer and chitosan as filler

    Science.gov (United States)

    Lubis, M.; Harahap, M. B.; Manullang, A.; Alfarodo; Ginting, M. H. S.; Sartika, M.

    2017-01-01

    Starch is a natural polymer that can be used for the production of bioplastics because its source is abundant, renewable and easily degraded. Jackfruit seeds can be used as raw material for bioplastics because its contains starch. The aim of this study to determine the characteristics of jackfruit seeds and determine the effect of chitosan and sorbitol on the physicochemical properties of bioplastics from jackfruit seeds. Starch is extracted from jackfruit seeds were then characterized to determine its chemical composition. In the manufacture of bioplastics starch composition jackfruit seeds - chitosan used was 7: 3, 8: 2 and 9: 1 (g/g), while the concentration of sorbitol used was 20%, 25%, 30%, 35%, and 40% by weight dry ingredients. From the analysis of jackfruit seed starch obtained water content of 6.04%, ash content of 1.08%, the starch content of 70.22%, 16.39% amylose content, amylopectin content of 53.83%, 4.68% protein content, fat content 0.54%. The best conditions of starch bioplastics jackfruit seeds obtained at a ratio of starch: chitosan (w/w) = 8: 2 and the concentration of plasticizer sorbitol 25% with tensile strength 13.524 MPa. From the results of FT-IR analysis indicated an increase for the OH group and the group NH on bioplastics due to the addition of chitosan and sorbitol. The results of mechanical tests is further supported by analysis of scanning electron microscopy (SEM) showing jackfruit seed starch has a small granule size with the size of 7.6 μm and in bioplastics with chitosan filler and plasticizer sorbitol their fracture surface is smooth and slightly hollow compared bioplastics without fillers chitosan and plasticizer sorbitol.

  17. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine; Etude de la selectivite de molecules extractantes polyazotees dans la complexation des actinides (III) et des lanthanides (III) en solution dans la pyridine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, Ch

    2000-10-05

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  18. Functional assignment of gene AAC16202.1 from Rhodobacter capsulatus SB1003: new insights into the bacterial SDR sorbitol dehydrogenases family.

    Science.gov (United States)

    Sola-Carvajal, Agustín; García-García, María Inmaculada; Sánchez-Carrón, Guiomar; García-Carmona, Francisco; Sánchez-Ferrer, Alvaro

    2012-11-01

    Short-chain dehydrogenases/reductases (SDR) constitute one of the largest enzyme superfamilies with over 60,000 non-redundant sequences in the database, many of which need a correct functional assignment. Among them, the gene AAC16202.1 (NCBI) from Rhodobacter capsulatus SB1003 has been assigned in Uniprot both as a sorbitol dehydrogenase (#D5AUY1) and, as an N-acetyl-d-mannosamine dehydrogenase (#O66112), both enzymes being of biotechnological interest. When the gene was overexpressed in Escherichia coli Rosetta (DE3)pLys, the purified enzyme was not active toward N-acetyl-d-mannosamine, whereas it was active toward d-sorbitol and d-fructose. However, the relative activities toward xylitol and l-iditol (0.45 and 6.9%, respectively) were low compared with that toward d-sorbitol. Thus, the enzyme could be considered sorbitol dehydrogenase (SDH) with very low activity toward xylitol, which could increase its biotechnological interest for determining sorbitol without the unspecific cross-determination of added xylitol in food and pharma compositions. The tetrameric enzyme (120 kDa) showed similar catalytic efficiency (2.2 × 10(3) M(-1) s(-1)) to other sorbitol dehydrogenases for d-sorbitol, with an optimum pH of 9.0 and an optimum temperature of 37 °C. The enzyme was also more thermostable than other reported SDH, ammonium sulfate being the best stabilizer in this respect, increasing the melting temperature (T(m)) up to 52.9 °C. The enzyme can also be considered as a new member of the Zn(2+) independent SDH family since no effect on activity was detected in the presence of divalent cations or chelating agents. Finally, its in silico analysis enabled the specific conserved sequence blocks that are the fingerprints of bacterial sorbitol dehydrogenases and mainly located at C-terminal of the protein, to be determined for the first time. This knowledge will facilitate future data curation of present databases and a better functional assignment of newly described

  19. Autodisplay of active sorbitol dehydrogenase (SDH) yields a whole cell biocatalyst for the synthesis of rare sugars.

    Science.gov (United States)

    Jose, Joachim; von Schwichow, Steffen

    2004-04-02

    Whole cell biocatalysts are attractive technological tools for the regio- and enantioselective synthesis of products, especially from substrates with several identical reactive groups. In the present study, a whole cell biocatalyst for the synthesis of rare sugars from polyalcohols was constructed. For this purpose, sorbitol dehydrogenase (SDH) from Rhodobacter sphaeroides, a member of the short-chain dehydrogenase/reductase (SDR) family, was expressed on the surface of Escherichia coli using Autodisplay. Autodisplay is an efficient surface display system for Gram-negative bacteria and is based on the autotransporter secretion pathway. Transport of SDH to the outer membrane was monitored by SDS-PAGE and Western blotting of different cell fractions. The surface exposure of the enzyme could be verified by immunofluorescence microscopy and fluorescence activated cell sorting (FACS). The activity of whole cells displaying SDH at the surface was determined in an optical test. Specific activities were found to be 12 mU per 3.3 x 10(8) cells for the conversion of D-glucitol (sorbitol) to D-fructose, 7 mU for the conversion D-galactitol to D-tagatose, and 17 mU for the conversion of L-arabitol to L-ribulose. The whole cell biocatalyst obtained by surface display of SDH could also produce D-glucitol from D-fructose (29 mU per 3.3 x 10(8) cells).

  20. Small Intestinal Bacterial Overgrowth May Increase the Likelihood of Lactose and Sorbitol but not Fructose Intolerance False Positive Diagnosis.

    Science.gov (United States)

    Perets, Tsachi Tsadok; Hamouda, Dalal; Layfer, Olga; Ashorov, Olga; Boltin, Doron; Levy, Sigal; Niv, Yaron; Dickman, Ram

    2017-08-01

    Small intestinal bacterial overgrowth (SIBO) is defined as a bacterial count of more than 10 5 colony-forming units per milliliter in duodenal aspirate. It shares many symptoms with carbohydrate intolerance, which makes the clinical distinction of the disorders difficult. The aim of the study was to examine the relationship between a positive carbohydrate breath test and the presence of SIBO suggested by a positive lactulose hydrogen breath test. The electronic database of the gastroenterology laboratory of a tertiary medical center was searched for all patients clinically tested for SIBO in 2012-2013 for whom previous results for lactose, fructose, and/or sorbitol breath test were available. The correlation between positive findings for carbohydrate intolerance and for SIBO was statistically analyzed. The study group included 349 patients, 231 female and 118 male, of mean age 53±19 years. All had symptoms of abdominal bloating and gas. There was a statistically significant difference in rates of a positive breath test for lactose and sorbitol at ≤90 minutes between patients who were positive and negative for SIBO [χ 2 (1)=12.8, p <0.01 and χ 2 (1)=9.5, p <0.01 respectively]. Findings for fructose were not significant. There was no effect of age or gender. SIBO may represent an important reversible cause of carbohydrate intolerance. It may be especially prudent to exclude SIBO patients with an early peak (≤90 minutes) in H 2 excretion. © 2017 by the Association of Clinical Scientists, Inc.

  1. Prevalence of sorbitol non-fermenting Shiga toxin-producing Escherichia coli in Black Bengal goats on smallholdings.

    Science.gov (United States)

    Das Gupta, M; Das, A; Islam, M Z; Biswas, P K

    2016-09-01

    A cross-sectional survey was carried out in Bangladesh with the sampling of 514 Black Bengal goats on smallholdings to determine the presence of sorbitol non-fermenting (SNF) Shiga toxin-producing E. coli (STEC). Swab samples collected from the recto-anal junction were plated onto cefixime and potassium tellurite added sorbitol MacConkey (CT-SMAC) agar, a selective medium for STEC O157 serogroup, where this serogroup and other SNF STEC produce colourless colonies. The SNF E. coli (SNF EC) isolates obtained from the survey were investigated by PCR for the presence of Shiga toxin-producing genes, stx1 and stx2, and two other virulence genes, eae and hlyA that code for adherence factor (intimin protein) and pore-forming cytolysin, respectively. The SNF EC isolates were also assessed for the presence of the rfbO157 gene to verify their identity to O157 serogroup. The results revealed that the proportions of goats carrying SNF EC isolates and stx1 and stx2 genes were 6·2% (32/514) [95% confidence interval (CI) 4·4-8·7)], 1·2% (95% CI 0·5-2·6) and 1·2% (95% CI 0·5-2·6), respectively. All the SNF STEC tested negative for rfbO157, hlyA and eae genes. The risk for transmission of STEC from Black Bengal goats to humans is low.

  2. Molecular Characterization of Human Atypical Sorbitol-Fermenting Enteropathogenic Escherichia coli O157 Reveals High Diversity.

    Science.gov (United States)

    Kossow, Annelene; Zhang, Wenlan; Bielaszewska, Martina; Rhode, Sophie; Hansen, Kevin; Fruth, Angelika; Rüter, Christian; Karch, Helge; Mellmann, Alexander

    2016-05-01

    Alongside the well-characterized enterohemorrhagic Escherichia coli (EHEC) O157:H7, serogroup O157 comprises sorbitol-fermenting typical and atypical enteropathogenic E. coli (EPEC/aEPEC) strains that carry the intimin-encoding gene eae but not Shiga toxin-encoding genes (stx). Since little is known about these pathogens, we characterized 30 clinical isolates from patients with hemolytic uremic syndrome (HUS) or uncomplicated diarrhea with respect to their flagellin gene (fliC) type and multilocus sequence type (MLST). Moreover, we applied whole-genome sequencing (WGS) to determine the phylogenetic relationship with other eae-positive EHEC serotypes and the composition of the rfbO157 region. fliC typing resulted in five fliC types (H7, H16, H34, H39, and H45). Isolates of each fliC type shared a unique ST. In comparison to the 42 HUS-associated E. coli (HUSEC) strains, only the stx-negative isolates with fliCH7 shared their ST with EHEC O157:H7/H(-) strains. With the exception of one O157:H(-) fliCH16 isolate, HUS was exclusively associated with fliCH7. WGS corroborated the separation of the fliCH7 isolates, which were closely related to the EHEC O157:H7/H(-) isolates, and the diverse group of isolates exhibiting different fliC types, indicating independent evolution of the different serotypes. This was also supported by the heterogeneity within the rfbO157 region that exhibited extensive recombinations. The genotypic subtypes and distribution of clinical symptoms suggested that the stx-negative O157 strains with fliCH7 were originally EHEC strains that lost stx The remaining isolates form a distinct and diverse group of atypical EPEC isolates that do not possess the full spectrum of virulence genes, underlining the importance of identifying the H antigen for clinical risk assessment. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan. Feature Article Volume 15 Issue 7 July 2010 pp 667-674. Fulltext. Click here to view fulltext PDF. Permanent link:

  4. A Novel Aqueous Micellar Two-Phase System Composed of Surfactant and Sorbitol for Purification of Pectinase Enzyme from Psidium guajava and Recycling Phase Components

    Science.gov (United States)

    Murshid, Fara Syazana; Manap, Mohd Yazid; Hussin, Muhaini

    2015-01-01

    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme. PMID:25756051

  5. A novel aqueous micellar two-phase system composed of surfactant and sorbitol for purification of pectinase enzyme from Psidium guajava and recycling phase components.

    Science.gov (United States)

    Amid, Mehrnoush; Murshid, Fara Syazana; Manap, Mohd Yazid; Hussin, Muhaini

    2015-01-01

    A novel aqueous two-phase system composed of a surfactant and sorbitol was employed for the first time to purify pectinase from Psidium guajava. The influences of different parameters, including the type and concentration of the surfactant and the concentration and composition of the surfactant/sorbitol ratio, on the partitioning behavior and recovery of pectinase were investigated. Moreover, the effects of system pH and the crude load on purification fold and the yield of purified pectinase were studied. The experimental results indicated that the pectinase was partitioned into surfactant-rich top phase, and the impurities were partitioned into the sorbitol-rich bottom phase with the novel method involving an ATPS composed of 26% (w/w) Triton X-100 and 23% (w/w) sorbitol at 54.2% of the TLL crude load of 20% (w/w) at pH 6.0. The enzyme was successfully recovered by this method with a high purification factor of 15.2 and a yield of 98.3%, whereas the phase components were also recovered and recycled at rates above 96%. This study demonstrated that this novel ATPS method can be used as an efficient and economical alternative to the traditional ATPS for the purification and recovery of the valuable enzyme.

  6. Foodborne transmission of sorbitol-fermenting Escherichia coli O157:[H7] via ground beef: an outbreak in northern France, 2011.

    Science.gov (United States)

    King, L A; Loukiadis, E; Mariani-Kurkdjian, P; Haeghebaert, S; Weill, F-X; Baliere, C; Ganet, S; Gouali, M; Vaillant, V; Pihier, N; Callon, H; Novo, R; Gaillot, O; Thevenot-Sergentet, D; Bingen, E; Chaud, P; de Valk, H

    2014-12-01

    Sorbitol-fermenting Escherichia coli O157:[H7] is a particularly virulent clone of E. coli O157:H7 associated with a higher incidence of haemolytic uraemic syndrome and a higher case fatality rate. Many fundamental aspects of its epidemiology remain to be elucidated, including its reservoir and transmission routes and vehicles. We describe an outbreak of sorbitol-fermenting E. coli O157:[H7] that occurred in France in 2011. Eighteen cases of paediatric haemolytic uraemic syndrome with symptom onset between 6 June and 15 July 2011 were identified among children aged 6 months to 10 years residing in northern France. A strain of sorbitol-fermenting E. coli O157:[H7] stx2a eae was isolated from ten cases. Epidemiological, microbiological and trace-back investigations identified multiply-contaminated frozen ground beef products bought in a supermarket chain as the outbreak vehicle. Strains with three distinct pulsotypes that were isolated from patients, ground beef preparations recovered from patients' freezers and from stored production samples taken at the production plant were indistinguishable upon molecular comparison. This investigation documents microbiologically confirmed foodborne transmission of sorbitol-fermenting of E. coli O157 via beef and could additionally provide evidence of a reservoir in cattle for this pathogen. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  7. A new selective fluorene-based fluorescent internal charge transfer (ICT) sensor for sugar alcohols in aqueous solution.

    Science.gov (United States)

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona

    2016-03-01

    Sugar alcohols, such as sorbitol, are commonly used as a replacement for sucrose in the food industry, applied as starting material for vitamin C synthesis, and involved as one of the causative factors in diabetic complications. Therefore, their detection and quantification in aqueous solution are necessary. The reversible covalent interactions between boronic acids and diols are the basis of efficient methods for the detection of saccharides. Herein, we report a new internal charge transfer (ICT) fluorene-based fluorescent boronic acid sensor (1) 2-[(9,9-dimethyl-9H-fluoren-2-yl-amino)methyl] phenyl boronic acid that shows significant fluorescence changes upon addition of saccharides. The boronic acid has high affinity (K a = 1107.9 M(-1)) and selectivity for sorbitol at pH = 8.31. It showed a linear response toward sorbitol in the concentration range from 1.0 × 10(-5) to 6.0 × 10(-4) mol L(-1) with the detection limit of 7.04 × 10(-6) mol L(-1). Sensor 1 was used to detect sorbitol in real samples with good recovery.

  8. Contrasting dynamics of fragile and non-fragile polyalcohols through the glass, and dynamical, transitions: A comparison of neutron scattering and dielectric relaxation data for sorbitol and glycerol.

    Science.gov (United States)

    Migliardo, F; Angell, C A; Magazù, S

    2017-01-01

    Glycerol and sorbitol are glass-forming hydrogen-bonded systems characterized by intriguing properties which make these systems very interesting also from the applications point of view. The goal of this work is to relate the hydrogen-bonded features, relaxation dynamics, glass transition properties and fragility of these systems, in particular to seek insight into their very different liquid fragilities. The comparison between glycerol and sorbitol is carried out by collecting the elastic incoherent neutron scattering (EINS) intensity as a function of temperature and of the instrumental energy resolution. Intensity data vs temperature and resolution are analyzed in terms of thermal restraint and Resolution Elastic Neutron Scattering (RENS) approaches. The number of OH groups, which are related to the connecting sites, is a significant parameter both in the glass transition and in the dynamical transition. On the other hand, the disordered nature of sorbitol is confirmed by the existence of different relaxation processes. From the applications point of view, glycerol and sorbitol have remarkable bioprotectant properties which make these systems useful in different technological and industrial fields. Furthermore, polyols are rich in glassforming liquid phenomenology and highly deserving of study in their own right. The comparison of EINS and calorimetric data on glycerol and sorbitol helps provide a connection between structural relaxation, dynamical transition, glass transition, and fragility. The evaluation of the inflection point in the elastic intensity behavior as a function of temperature and instrumental energy resolution provides a confirmation of the validity of the RENS approach. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo. Copyright © 2016. Published by Elsevier B.V.

  9. Lactase Non-Persistence Genotyping: Comparison of Two Real-Time PCR Assays and Assessment of Concomitant Fructose/Sorbitol Malabsorption Rates.

    Science.gov (United States)

    Enko, Dietmar; Pollheimer, Verena; Németh, Stefan; Pühringer, Helene; Stolba, Robert; Halwachs-Baumann, Gabriele; Kriegshäuser, Gernot

    2016-01-01

    Genetic testing is a standard technique for the diagnosis of primary adult-type hypolactasia, also referred to as lactase non-persistence. The aim of this study was to compare the lactase gene (LCT) C/T-13910 polymorphism genotyping results of two commercially available real-time (RT)-PCR assays in patients referred to our outpatient clinic for primary lactose malabsorption testing. Furthermore, concomitant conditions of fructose/sorbitol malabsorption were assessed. Samples obtained from 100 patients were tested in parallel using the LCT T-13910C ToolSet for Light Cycler (Roche, Rotkreuz, Switzerland) and the LCT-13910C>T RealFast Assay (ViennaLab Diagnostics GmbH, Vienna, Austria). Additionally, patients were also screened for the presence of fructose/sorbitol malabsorption by functional hydrogen (H2)/methane (CH4) breath testing (HMBT). Cohen's Kappa (κ) was used to calculate the agreement between the two genotyping methods. The exact Chi-Square test was performed to compare fructose/sorbitol HMBT with LCT genotyping results. Twenty-one (21.0%) patients had a LCT C/C-13910 genotype suggestive of lactase non-persistence, and 79 (79.0%) patients were identified with either a LCT T/C-13910 or T/T-13910 genotype (i.e., lactase persistence). In all genotype groups, concordance between the two RT-PCR assays was 100%. Cohen's κ demonstrated perfect observed agreement (p sorbitol malabsorption was observed in 13/100 (13.0%) and 25/100 (25.0%) individuals, respectively. Both RT-PCR assays are robust and reliable LCT genotyping tools in a routine clinical setting. Concomitant fructose and/or sorbitol malabsorption should be considered in individuals with suspected lactase-non-persistence. However, standardization of clinical interpretation of laboratory HMBT results is required.

  10. Single-molecule dynamics in nanofabricated traps

    Science.gov (United States)

    Cohen, Adam

    2009-03-01

    The Anti-Brownian Electrokinetic trap (ABEL trap) provides a means to immobilize a single fluorescent molecule in solution, without surface attachment chemistry. The ABEL trap works by tracking the Brownian motion of a single molecule, and applying feedback electric fields to induce an electrokinetic motion that approximately cancels the Brownian motion. We present a new design for the ABEL trap that allows smaller molecules to be trapped and more information to be extracted from the dynamics of a single molecule than was previously possible. In particular, we present strategies for extracting dynamically fluctuating mobilities and diffusion coefficients, as a means to probe dynamic changes in molecular charge and shape. If one trapped molecule is good, many trapped molecules are better. An array of single molecules in solution, each immobilized without surface attachment chemistry, provides an ideal test-bed for single-molecule analyses of intramolecular dynamics and intermolecular interactions. We present a technology for creating such an array, using a fused silica plate with nanofabricated dimples and a removable cover for sealing single molecules within the dimples. With this device one can watch the shape fluctuations of single molecules of DNA or study cooperative interactions in weakly associating protein complexes.

  11. Analise térmica e microscópica de laminados biodegradáveis obtidos a partir de farinha de mandioca, sorbitol e poli (butileno adipato co-tereftalato PBAT. Thermal and microscopic analysis of biodegradable laminates made from cassava flour, sorbitol and poly (butylene adipate-co-terephthalate PBAT - doi: 10.4025/actascitechnol.v35i4.13183

    Directory of Open Access Journals (Sweden)

    Henrique Tirolli Rett

    2013-10-01

    Full Text Available O objetivo deste trabalho foi desenvolver blendas de materiais laminados biodegradáveis, utilizando farinha de mandioca como fonte de amido, fibras naturais, sorbitol como plastificante e PBAT. Primeiro obteve-se peletes de três formulações diferentes e a partir destes, utilizou-se a termoprensagem a alta temperatura como alternativa na formação dos laminados. A caracterização foi feita através de microscopia eletrônica de varredura (MEV e calorimetria diferencia de varredura (CDV. A quantidade se sorbitol que melhor se ajustou à extrusão foi a de 15% (peso/peso; a formulação do laminado mais homogêneo, observada pela microscopia, foi de 55:40:15 (farinha/sorbitol/PBAT. As fibras ficaram dispersas por toda a superfície nos três tratamentos estudados, porém, por dentre eles, observaram-se zonas dispersas das fibras. Conforme se aumentou o teor de farinha, houve aumento no ponto de fusão dos laminados em comparação ao PBAT puro.Blends of biodegradable laminated materials were developed using cassava flour as starch and natural fibers source, sorbitol as a plasticizer and PBAT as a biodegradable polyester. After obtaining pellets from three different formulations, high temperature thermopressure was used to form laminates. The characterization was performed by scanning electron microscopy (SEM and by differential scanning calorimetry (DSC. The amount of sorbitol for the best extrusion process was 15% (weight/weight and the formulation of the best homogeneity observed by microscopy was 55:40:15 (flour/sorbitol/PBAT. Although fibers were dispersed throughout the surface in the three treatments, scattered areas of fibers could be found among them. As rates of flour increased, an increase in the melting point of the laminates occurred when compared to pure PBAT.  

  12. Primary double contrast study of the colon with citrate-sorbitol-barium suspension in the diagnosis of chronic colitis

    International Nuclear Information System (INIS)

    Sidorov, V.S.

    1991-01-01

    X-ray investigation of the colon was conducted in 292 patients with clinically diagnosed chronic colitis: standard 3-phase irrigoscopy-in 189 patients and a primary double contrast study of the colon with citrate-sorbitol-barium suspenzion - in 103. Basing on X-ray and morphological findings, the diagnosis was confirmed in 128 patients of the 1st group (68.2 %) and in 89 patients of the 2nd group (86 %). The primary double contrast study of the colon was found more effective as it permitted the detection of elements of the mucosal microcontours: transversal strips, not coinciding with haustration, focal granularity, diffuse granularity, small barium suspension depots or niches, nodular granularity. It permitted the recommendation of the method for a wide clinical use

  13. Copper-zinc electrodeposition in alkaline-sorbitol medium: Electrochemical studies and structural, morphological and chemical composition characterization

    Science.gov (United States)

    de Almeida, M. R. H.; Barbano, E. P.; de Carvalho, M. F.; Tulio, P. C.; Carlos, I. A.

    2015-04-01

    The galvanostatic technique was used to analyze the electrodeposition of Cu-Zn on to AISI 1010 steel electrode from an alkaline-sorbitol bath with various proportions of the metal ions in the bath: Cu70/Zn30, Cu50/Zn50 and Cu30/Zn70. Coloration of Cu-Zn films were whitish golden, light golden, golden/gray depending on the Cu2+/Zn2+ ratios in the electrodeposition bath, deposition current density (jdep) and charge density (qdep). The highest current efficiency was ∼54.0%, at jdep -1.0 mA cm-2 and qdep 0.40 C cm-2 in the Cu70/Zn30 bath. Energy dispersive spectroscopy indicated that electrodeposits produced from the bath Cu70/Zn30 showed higher Cu content at lower jdep. Also, for same jdep the Cu content increased with qdep. Scanning electron microscopy showed that Cu-Zn electrodeposits of high quality were obtained from the Cu70/Zn30 bath, since the films were fine-grained, except the obtained at jdep -20.0 mA cm-2 and qdep 10.0 C cm-2. Also, these electrodeposits did not present cracks. X-ray analysis of the Cu-Zn electrodeposits obtained at jdep -8.0, -20.0 and -40.0 mA cm-2, in each case, with qdep 2.0 and 10.0 C cm-2, in the Cu70/Zn30 bath, suggested the occurrence of a mixture of the following phases, CuZn, CuZn5 and Cu5Zn8. Galvanostatic electrodeposits of Cu-Zn obtained from sorbitol-alkaline baths exhibited whitish golden color, with good prospects for industrial applications, especially for decorative purposes.

  14. Association study of sorbitol dehydrogenase -888G>C polymorphism with type 2 diabetic retinopathy in Caucasian-Brazilians.

    Science.gov (United States)

    Ferreira, Fábio Netto; Crispim, Daisy; Canani, Luís Henrique; Gross, Jorge Luiz; dos Santos, Kátia Gonçalves

    2013-10-01

    Diabetic retinopathy (DR) is a common chronic complication of diabetes and remains the leading cause of blindness in working-aged people. Hyperglycemia increases glucose flux through the polyol pathway, in which aldose reductase converts glucose into intracellular sorbitol, which is subsequently converted to fructose by sorbitol dehydrogenase (SDH). The accelerated polyol pathway triggers a cascade of events leading to retinal vascular endothelial dysfunction and the eventual development of DR. Polymorphisms in the gene encoding aldose reductase have been consistently associated with DR. However, only two studies have analyzed the relationship between polymorphisms in the gene encoding SDH (SORD) and DR. In this case-control study, we investigated whether the -888G > C polymorphism (rs3759890) in the SORD gene is associated with the presence or severity of DR in 446 Caucasian-Brazilians with type 2 diabetes (241 subjects with and 205 subjects without DR). The -888G > C polymorphism was also examined in 105 healthy Caucasian blood donors, and the genotyping of this polymorphism was carried out by real-time PCR. The genotype and allele frequencies of the -888G > C polymorphism in patients with type 2 diabetes were similar to those of blood donors (G allele frequency = 0.16 in both groups of subjects). Similarly, the genotype and allele frequencies in patients with DR or the proliferative form of DR were similar to those of patients without this complication (P > 0.05 for all comparisons). Thus, our findings suggest that the -888G > C polymorphism in the SORD gene is not involved in the pathogenesis of DR in type 2 diabetes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Generalizations of the Toda molecule

    Science.gov (United States)

    Van Velthoven, W. P. G.; Bais, F. A.

    1986-12-01

    Finite-energy monopole solutions are constructed for the self-dual equations with spherical symmetry in an arbitrary integer graded Lie algebra. The constraint of spherical symmetry in a complex noncoordinate basis leads to a dimensional reduction. The resulting two-dimensional ( r, t) equations are of second order and furnish new generalizations of the Toda molecule equations. These are then solved by a technique which is due to Leznov and Saveliev. For time-independent solutions a further reduction is made, leading to an ansatz for all SU(2) embeddings of the Lie algebra. The regularity condition at the origin for the solutions, needed to ensure finite energy, is also solved for a special class of nonmaximal embeddings. Explicit solutions are given for the groups SU(2), SO(4), Sp(4) and SU(4).

  16. Structure and equilibria of Ca 2+-complexes of glucose and sorbitol from multinuclear ( 1H, 13C and 43Ca) NMR measurements supplemented with molecular modelling calculations

    Science.gov (United States)

    Pallagi, A.; Dudás, Cs.; Csendes, Z.; Forgó, P.; Pálinkó, I.; Sipos, P.

    2011-05-01

    Ca 2+-complexation of D-glucose and D-sorbitol have been investigated with the aid of multinuclear ( 1H, 13C and 43Ca) NMR spectroscopy and ab initio quantum chemical calculations. Formation constants of the forming 1:1 complexes have been estimated from one-dimensional 13C NMR spectra obtained at constant ionic strength (1 M NaCl). Binding sites were identified from 2D 1H- 43Ca NMR spectra. 2D NMR measurements and ab initio calculations indicated that Ca 2+ ions were bound in a tridentate manner via the glycosidic OH, the ethereal oxygen in the ring and the OH on the terminal carbon for the α- and β-anomers of glucose and for sorbitol simultaneous binding of four hydroxide moieties (C1, C2, C4 and C6) was suggested.

  17. Filming the Birth of Molecules and Accompanying Solvent Rearrangement

    DEFF Research Database (Denmark)

    Lee, Jae Hyuk; Wulff, Michael; Bratos, Savo

    2013-01-01

    Molecules are often born with high energy and large-amplitude vibrations. In solution, a newly formed molecule cools down by transferring energy to the surrounding solvent molecules. The progression of the molecular and solute−solvent cage structure during this fundamental process has been elusiv...

  18. Improving Performance and Operational Stability of Porcine Interferon-α Production by Pichia pastoris with Combinational Induction Strategy of Low Temperature and Methanol/Sorbitol Co-feeding.

    Science.gov (United States)

    Gao, Min-Jie; Zhan, Xiao-Bei; Gao, Peng; Zhang, Xu; Dong, Shi-Juan; Li, Zhen; Shi, Zhong-Ping; Lin, Chi-Chung

    2015-05-01

    Various induction strategies were investigated for effective porcine interferon-α (pIFN-α) production by Pichia pastoris in a 10 L fermenter. We found that pIFN-α concentration could be significantly improved with the strategies of low-temperature induction or methanol/sorbitol co-feeding. On this basis, a combinational strategy of induction at lower temperature (20 °C) with methanol/sorbitol co-feeding has been proposed for improvement of pIFN-α production. The results reveal that maximal pIFN-α concentration and antiviral activity reach the highest level of 2.7 g/L and 1.8 × 10(7) IU/mg with the proposed induction strategy, about 1.3-2.1 folds higher than those obtained with other sub-optimal induction strategies. Metabolic analysis and online multi-variable measurement results indicate that energy metabolic enrichment is responsible for the performance enhancement of pIFN-α production, as a large amount of ATP could be simultaneously produced from both formaldehyde oxidation pathway in methanol metabolism and tricarboxylic acid (TCA) cycle in sorbitol metabolism. In addition, the proposed combinational induction strategy enables P. pastoris to be resistant to high methanol concentration (42 g/L), which conceivably occur associating with the error-prone methanol over-feeding. As a result, the proposed combinational induction strategy simultaneously increased the targeted protein concentration and operational stability leading to significant improvement of pIFN-α production.

  19. The effect of the addition of sorbitol and glycerol towards the edible film characteristics of the belitung taro starch and the lime leaves as antimicrobial

    Science.gov (United States)

    Asria, Merry; Elizarni, Samah, dan Selfa Dewati

    2015-12-01

    Plastics have been generally used for food packaging, but plastics using causing environmental problem for as non biodegradable. Resolving the problem need another alternative packaging that environmental friendly such as the edible film as biodegradable packing material. This research intend to determination the effects of sorbitol and glycerol (concentration of 1%, 2%, 3%, and 4%) as addition to the edible film characteristics from the belitung taro starch (Xanthosoma sagitifolium). Lime leaves (Citrus aurantifolia) extract used as an antimicrobial film (2%, 4%, 6%, 8%, and 10% respectively). From the research obtained that using sorbitol has given more rigid and hard film texture, while glycerol provides more elastic and flexible texture. Sorbitol give best performance at 2% where thickness 0.17 mm; tensile strength 41.60 MPa; yield strength 34.28 MPa; modulus of elasticity 7983.71 MPa; and maximum strain 29,8%. While, glycerol (2%) provides thickness 0.18 mm; tensile strength 35.72 MPa; yield strength 30.78 MPa; modulus of elasticity 9065.90 MPa; and maximum strain 14.4% for best performance. SEM and FTIR analysis applied to determine film surface morphology's characterization and determine the functional groups of the film materials. The addition of lime leaves extract as antimicrobial gives the growth inhibition activity against the Staphylococcus aureus bacteria.

  20. JNK signaling pathway regulates sorbitol-induced Tau proteolysis and apoptosis in SH-SY5Y cells by targeting caspase-3.

    Science.gov (United States)

    Olivera Santa-Catalina, Marta; Caballero Bermejo, Montaña; Argent, Ricardo; Alonso, Juan C; Centeno, Francisco; Lorenzo, María J

    2017-12-15

    Growing evidence suggests that Diabetes Mellitus increases the risk of developing Alzheimer's disease. It is well known that hyperglycemia, a key feature of Diabetes Mellitus, may induce plasma osmolarity disturbances. Both hyperglycemia and hyperosmolarity promote the altered post-translational regulation of microtubule-associated protein Tau. Interestingly, abnormal hyperphosphorylation and cleavage of Tau have been proven to lead to the genesis of filamentous structures referred to as neurofibrillary tangles, the main pathological hallmark of Alzheimer's disease. We have previously described that hyperosmotic stress induced by sorbitol promotes Tau proteolysis and apoptosis in SH-SY5Y cells via caspase-3 activation. In order to gain insights into the regulatory mechanisms of such processes, in this work we explored the intracellular signaling pathways that regulate these events. We found that sorbitol treatment significantly enhanced the activation of conventional families of MAPK in SH-SY5Y cells. Tau proteolysis was completely prevented by JNK inhibition but not affected by either ERK1/2 or p38 MAPK blockade. Moreover, inhibition of JNK, but not ERK1/2 or p38 MAPK, efficiently prevented sorbitol-induced apoptosis and caspase-3 activation. In summary, we provide evidence that JNK signaling pathway is an upstream regulator of hyperosmotic stress-induced Tau cleavage and apoptosis in SH-SY5Y through the control of caspase-3 activation. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Fractal aspects of the flow and shear behaviour of free-flowable particle size fractions of pharmaceutical directly compressible excipient sorbitol.

    Science.gov (United States)

    Hurychová, Hana; Lebedová, Václava; Šklubalová, Zdenka; Dzámová, Pavlína; Svěrák, Tomáš; Stoniš, Jan

    Flowability of powder excipients is directly influenced by their size and shape although the granulometric influence of the flow and shear behaviour of particulate matter is not studied frequently. In this work, the influence of particle size on the mass flow rate through the orifice of a conical hopper, and the cohesion and flow function was studied for four free-flowable size fractions of sorbitol for direct compression in the range of 0.080-0.400 mm. The particles were granulometricaly characterized using an optical microscopy; a boundary fractal dimension of 1.066 was estimated for regular sorbitol particles. In the particle size range studied, a non-linear relationship between the mean particle size and the mass flow rate Q10 (g/s) was detected having amaximum at the 0.245mm fraction. The best flow properties of this fraction were verified with aJenike shear tester due to the highest value of flow function and the lowest value of the cohesion. The results of this work show the importance of the right choice of the excipient particle size to achieve the best flow behaviour of particulate material.Key words: flowability size fraction sorbitol for direct compaction Jenike shear tester fractal dimension.

  2. A comparative study on cellulose nanocrystals extracted from bleached cotton and flax and used for casting films with glycerol and sorbitol plasticisers.

    Science.gov (United States)

    Csiszár, Emilia; Nagy, Sebestyén

    2017-10-15

    Cellulose nanocrystals (CNCs) were released from bleached cotton and flax by a sulphuric acid hydrolysis with about 40 and 34% yield, respectively. The rod-like cotton-CNC particles were slightly longer and wider and had a less pronounced aggregation ability in aqueous suspension than the flax-CNC ones. Films were cast from the CNC suspensions with sorbitol and glycerol plasticisers. The concept behind this research was to explore how the plasticisers - with similar structure but different molecular weight - and their concentrations affect the perceptible and measured properties of CNC films. Results revealed that the type of plasticiser determined the morphology and the optical and tensile properties of films. The best quality CNC film with an averaged thickness of 50μm was obtained with 20% sorbitol from cotton-CNC. It was proved that behaviour of sorbitol and glycerol plasticisers in CNC films was very similar to that reported previously for starch films. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Development of selective and differential medium for Shigella sonnei using three carbohydrates (lactose, sorbitol, and xylose) and X-Gal.

    Science.gov (United States)

    Na, G N; Kim, S A; Kwon, O C; Rhee, M S

    2015-08-01

    The aim of this study was to develop a new selective and differential medium for isolating Shigella sonnei (designated 3SD medium). The new medium was based on three carbohydrates (lactose, sorbitol, and xylose) and a chromogenic substrate (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside, X-Gal). S. sonnei cannot ferment lactose, sorbitol, or xylose, but can ferment X-Gal, which generates turquoise-blue colonies with rough edges. Other bacteria (54 strains of foodborne pathogens and spoilage bacteria) produced visually distinct colonies on 3SD medium (colorless or pink-violet colonies), or their growth was inhibited on 3SD medium. The optimum concentration of 50 mg/L X-Gal was selected because it yielded the highest level of morphological discrimination between S. sonnei and other bacteria, and this concentration was cost-effective. Bile salt concentration optimization was performed using healthy, heat-injured, and acid-injured S. sonnei. The recovery rate differed significantly depending on the bile salt concentration; media containing >1.0 g/L bile salt showed significantly lower recovery of stress-injured cells than medium containing 0.5 g/L bile salt (P<0.05). Growth of all Gram-positive bacteria was inhibited on medium containing 0.5 g/L bile salt; therefore, this concentration was used as the optimal concentration. Previous media used to isolate Shigella spp. (MacConkey, xylose lysine desoxycholate, and Salmonella-Shigella agar) showed poor performance when used to support the growth of injured S. sonnei cells, whereas 3SD medium supported a high growth rate of injured and healthy cells (equivalent to that obtained with nutrient-rich tryptic soy agar). To validate the performance of 3SD medium with real specimens, S. sonnei and other bacteria were spiked into samples such as untreated water, carrot, salad, and oyster. 3SD medium showed superior specificity (100%) and sensitivity (100%) for S. sonnei, and yielded no false-positive or false-negative results

  4. Diffusion of aqueous solutions of ionic, zwitterionic, and polar solutes

    Science.gov (United States)

    Teng, Xiaojing; Huang, Qi; Dharmawardhana, Chamila Chathuranga; Ichiye, Toshiko

    2018-06-01

    The properties of aqueous solutions of ionic, zwitterionic, and polar solutes are of interest to many fields. For instance, one of the many anomalous properties of aqueous solutions is the behavior of water diffusion in different monovalent salt solutions. In addition, solutes can affect the stabilities of macromolecules such as proteins in aqueous solution. Here, the diffusivities of aqueous solutions of sodium chloride, potassium chloride, tri-methylamine oxide (TMAO), urea, and TMAO-urea are examined in molecular dynamics simulations. The decrease in the diffusivity of water with the concentration of simple ions and urea can be described by a simple model in which the water molecules hydrogen bonded to the solutes are considered to diffuse at the same rate as the solutes, while the remainder of the water molecules are considered to be bulk and diffuse at almost the same rate as pure water. On the other hand, the decrease in the diffusivity of water with the concentration of TMAO is apparently affected by a decrease in the diffusion rate of the bulk water molecules in addition to the decrease due to the water molecules hydrogen bonded to TMAO. In other words, TMAO enhances the viscosity of water, while urea barely affects it. Overall, this separation of water molecules into those that are hydrogen bonded to solute and those that are bulk can provide a useful means of understanding the short- and long-range effects of solutes on water.

  5. Efecto del sorbitol sobre la relajación estructural en películas de gelatina en estado vítreo

    Directory of Open Access Journals (Sweden)

    Paulo Díaz-Calderón

    2015-12-01

    Full Text Available El objetivo de este trabajo fue evaluar el efecto del sorbitol sobre la cinética de relajación estructural de películas de gelatina almacenadas bajo la temperatura de transición vítrea (Tg. Películas de gelatina de bovino y sorbitol fueron preparadas mediante casting en frío. El sorbitol fue agregado en fracciones en peso (Qs de 0,0, 0,06 y 0,10. Las películas fueron acondicionadas en un ambiente de humedad relativa constante (44% utilizando una solución saturada de carbonato de potasio, obteniéndose fracciones de contenido de humedad en peso (Qw de 0,18, 0,16 y 0,18 respectivamente. La entalpía de relajación (∆H fue determinada mediante Calorimetría Diferencial de Barrido (DSC. Las muestras utilizadas en este estudio presentaron valores de Tg de 48ºC (Qs=0,0, 35ºC (Qs=0,06 y 30ºC (Qs=0,10. Luego de eliminar el historial térmico (30ºC sobre Tg, 15min, las muestras fueron almacenadas isotérmicamente a 10ºC bajo Tgonset entre 2 y 80 horas. La adición de sorbitol produjo una reducción signifi cativa (p<0,05 en la cinética de relajación estructural. La linealización del valor de entalpía de relajación (∆H en función del logaritmo del tiempo de almacenamiento mostró una reducción de la pendiente en las muestras plastifi cadas con sorbitol. La reducción en la cinética de relajación estaría relacionada con el efecto de empaquetamiento molecular asociado a la presencia de polioles en matrices en estado vítreo recientemente reportada mediante espectroscopía de positrones (PALS

  6. Physics of atoms and molecules

    International Nuclear Information System (INIS)

    Bransden, B.H.; Joachain, C.J.

    1983-01-01

    This book presents a unified account of the physics of atoms and molecules at a level suitable for second- and third-year undergraduate students of physics and physical chemistry. Following a brief historical introduction to the subject the authors outline the ideas and approximation methods of quantum mechanics to be used later in the book. Six chapters look at the structure of atoms and the interactions between atoms and electromagnetic radiation. The authors then move on to describe the structure of molecules and molecular spectra. Three chapters deal with atomic collisions, the scattering of electrons by atoms and the scattering of atoms by atoms. The concluding chapter considers a few of the many important applications of atomic physics within astrophysics, laser technology, and nuclear fusion. Problems are given at the end of each chapter, with hints at the solutions in an appendix. Other appendices include various special topics and derivations together with useful tables of units. (author)

  7. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  8. Jet-Fuel Range Hydrocarbons from Biomass-Derived Sorbitol over Ni-HZSM-5/SBA-15 Catalyst

    Directory of Open Access Journals (Sweden)

    Yujing Weng

    2015-12-01

    Full Text Available Aromatics and cyclic-hydrocarbons are the significant components of jet fuel with high energy-density. However, conventional technologies for bio-fuel production cannot produce these products without further aromatization and isomerization. In this work, renewable liquid fuel with high content of aromatics and cyclic-hydrocarbons was obtained through aqueous catalytic conversion of biomass sorbitol over Ni-HZSM-5/SBA-15 catalyst. Texture characteristics of the catalyst were determined by physisorption of N2, which indicated its bimodal pore structures were microporous (HZSM-5, pore width: 0.56 nm and mesoporous (SBA-15, pore width: 8 nm. The surface acidity included weak and strong acid sites, predominantly Lewis type, and was further confirmed by the NH3-TPD and Py-IR analysis. The catalytic performances were tested in a fixed-bed reactor under the conditions of 593 K, WHSV of 0.75 h−1, GHSV of 2500 h−1 and 4.0 MPa of hydrogen pressure, whereby oil yield of 40.4 wt. % with aromatics and cyclic-hydrocarbons content of 80.0% was obtained.

  9. Carbon-coated ceramic membrane reactor for the production of hydrogen by aqueous-phase reforming of sorbitol.

    Science.gov (United States)

    Neira D'Angelo, M F; Ordomsky, V; Schouten, J C; van der Schaaf, J; Nijhuis, T A

    2014-07-01

    Hydrogen was produced by aqueous-phase reforming (APR) of sorbitol in a carbon-on-alumina tubular membrane reactor (4 nm pore size, 7 cm long, 3 mm internal diameter) that allows the hydrogen gas to permeate to the shell side, whereas the liquid remains in the tube side. The hydrophobic nature of the membrane serves to avoid water loss and to minimize the interaction between the ceramic support and water, thus reducing the risks of membrane degradation upon operation. The permeation of hydrogen is dominated by the diffusivity of the hydrogen in water. Thus, higher operation temperatures result in an increase of the flux of hydrogen. The differential pressure has a negative effect on the flux of hydrogen due to the presence of liquid in the larger pores. The membrane was suitable for use in APR, and yielded 2.5 times more hydrogen than a reference reactor (with no membrane). Removal of hydrogen through the membrane assists in the reaction by preventing its consumption in undesired reactions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Influence of sorbitol on mechanical and physico-chemical properties of soy protein-based bioplastics processed by injection molding

    Directory of Open Access Journals (Sweden)

    Manuel Felix

    Full Text Available Abstract Soy Protein Isolate (SPI has been evaluated as useful candidate for the development of protein-based bioplastic materials processed by injection molding. The influence of sorbitol (SB as plasticizer in mechanical properties and water uptake capacity was evaluated in SPI-based bioplastics. A mixing rheometer that allows monitoring torque and temperature during mixing and a small-scale-plunger-type injection molding machine were used to obtain SPI/Plasticizer blends and SPI-based bioplastics, respectively. Dynamic measurements were carried out to obtain mechanical spectra of different bioplastics. Moreover, the mechanical characterization was supplemented with uniaxial tensile tests. Additionally, the influence of SB in water uptake capacity was also evaluated. The introduction of SB leads to increase the rigidity of bioplastics as well as the water uptake capacity after 24h, however it involves a decrease in strain at break. Final bioplastics are plastic materials with both adequate properties for the substitution of conventional petroleum plastics and high biodegradability.

  11. Severe Outbreak of Sorbitol-Fermenting Escherichia coli O157 via Unpasteurized Milk and Farm Visits, Finland 2012.

    Science.gov (United States)

    Jaakkonen, A; Salmenlinna, S; Rimhanen-Finne, R; Lundström, H; Heinikainen, S; Hakkinen, M; Hallanvuo, S

    2017-09-01

    Shiga toxin-producing, sorbitol-fermenting Escherichia coli O157 (SF O157) has emerged as a cause of severe human illness. Despite frequent human findings, its transmission routes and reservoirs remain largely unknown. Foodborne transmission and reservoir in cattle have been suspected, but with limited supporting evidence. This study describes the outbreak of SF O157 that occurred in Finland in 2012. The outbreak originated from a recreational farm selling unpasteurized milk, as revealed by epidemiologic and microbiological investigations, and involved six hospitalized children and two asymptomatic adults with culture-confirmed infection. An identical strain of SF O157 was isolated from patients, cattle and the farm environment, and epidemiologic analysis suggested unpasteurized milk as the vehicle of transmission. This study reports the first milkborne outbreak of SF O157, provides supporting evidence of cattle as a reservoir and highlights the health risks related to the consumption of unpasteurized milk. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

  12. Free fatty acid suppositories are as effective as docusate sodium and sorbitol enemas in treating constipation in children.

    Science.gov (United States)

    Ormarsson, Orri Thor; Asgrimsdottir, Gudrun Marta; Loftsson, Thorsteinn; Stefansson, Einar; Lund, Sigrun Helga; Bjornsson, Einar Stefan

    2016-06-01

    A well-documented, clinically proven per rectum treatment for childhood constipation is needed. This phase two clinical trial evaluated the efficacy of suppositories containing free fatty acids (FFA) compared with Klyx docusate sodium and sorbitol enemas. A randomised, controlled, single-blind study was undertaken on 77 children aged between one and 17 who presented to an emergency department in Iceland and were diagnosed with constipation. In stage one, 23 patients were randomised to receive lower dose FFA suppositories or Klyx (n = 33). In stage two, 21 different patients were randomised to receive higher dose suppositories and compared with the same Klyx control subjects. The suppositories were effective at bowel emptying in 39% of the group who received the lower FFA doses and 81% of the group receiving higher doses, compared with 88% in the Klyx control group. Symptom relief was obtained in 30% of the group receiving the lower doses and 71% of the group receiving the higher doses, compared with 73% in the control group. The higher dose FFA suppositories were as effective as the Klyx enemas with regard to bowel emptying and symptom relief and might provide an important and less invasive alternative for childhood constipation. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  13. 1,2,3,4-bis(p-methylbenzylidene sorbitol) accelerates crystallization and improves hole mobility of poly(3-hexylthiophene)

    Science.gov (United States)

    Yuan, Nana; Huo, Hong

    2016-02-01

    The addition of 1,2,3,4-bis(p-methylbenzylidene sorbitol) (MDBS) does not change the nucleation mechanism or the crystal form of poly(3-hexylthiophene) (P3HT), but its presence increases the crystallization temperature (T c) of P3HT, decreases the crystallization half-time (t 1/2) and accelerates P3HT crystallization, which indicates that MDBS is an effective nucleating agent for P3HT. An acceleration of P3HT crystallization by the addition of MDBS decreases the crystalline size and crystallinity of P3HT, and enhances the connectivity between ordered regions of P3HT, leading to the hole mobility rising from 1.99 × 10-6 to 7.57 × 10-5 cm2 V-1s-1 in P3HT:PCBM blend based hole-only devices with sandwich configurations. Our results suggest that accelerating P3HT crystallization by adding a nucleating agent might be an important factor to improve the hole mobility and balance the electron and hole mobility in a photovoltaic blend.

  14. Green Synthesis of Silver Nanoparticles Using Polyalthia longifolia Leaf Extract along with D-Sorbitol: Study of Antibacterial Activity

    Directory of Open Access Journals (Sweden)

    S. Kaviya

    2011-01-01

    Full Text Available Synthesis of silver nanoparticles (AgNPs using Polyalthia longifolia leaf extract as reducing and capping agent along with D-sorbitol used to increase the stability of the nanoparticles has been reported. The reaction is carried out at two different concentrations (10−3 M and 10−4 M of silver nitrate, and the effect of temperature on the synthesis of AgNPs is investigated by stirring at room temperature (25°C and at 60°C. The UV-visible spectra of NPs showed a blue shift with increasing temperature at both concentrations. FT-IR analysis shows that the biomoites played an important role in the reduction of Ag+ ions and the growth of AgNPs. TEM results were utilized for the determination of the size and morphology of nanoparticles. The synthesized silver nanoparticles are found to be highly toxic against Gram-positive bacteria than Gram-negative bacteria.

  15. Chitin hydrolysis assisted by cell wall degrading enzymes immobilized of Thichoderma asperellum on totally cinnamoylated D-sorbitol beads

    International Nuclear Information System (INIS)

    Fernandes, Kátia F.; Cortijo-Triviño, David; Batista, Karla A.; Ulhoa, Cirano J.; García-Ruiz, Pedro A.

    2013-01-01

    In this study, cell wall degrading enzymes produced by Thrichoderma asperellum (TCWDE) were immobilized on totally cinnamoylated D-sorbitol (TCNSO) beads and used for chitin hydrolysis. In order to optimize immobilization efficiency, the reaction time was varied from 2 to 12 h and reactions were conducted in the presence or absence of Na 2 SO 4 . Immobilized enzymes were analysed concerning to thermal and operational stability. Immobilization in presence of Na 2 SO 4 was 54% more efficient than immobilization in absence of salt. After optimization, 32% of the total enzyme offered was immobilized, with 100% of bounding efficiency, measured as the relation between protein and enzyme immobilized. Free and TCNSO–TCWDE presented very similar kinetics with maximum hydrolysis reached at 90 min of reaction. Thermal stability of both free and TCNSO–TCWDE was similar, with losses in activity after 55 °C. Moreover, free and TCNSO–TCWDE retained 100% activity after 3 h incubation at 55 °C. TCNSO–TCWDE were used in a bath-wise reactor during 14 cycles, producing 1825 μg of N-acetylglucosamine (NAG) maintaining 83% of initial activity. - Highlights: • TCWDE immobilized on TCNSO, a support with highly hydrophobic character • New immobilization strategy for immobilization on a hydrophobic support • TCNSO–TCWDE were retained during washes and during incubation at 55 °C for 3 h

  16. Chitin hydrolysis assisted by cell wall degrading enzymes immobilized of Thichoderma asperellum on totally cinnamoylated D-sorbitol beads

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Kátia F., E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Instituo de Ciências Biológicas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970 Goiânia, GO (Brazil); Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Cortijo-Triviño, David [Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain); Batista, Karla A.; Ulhoa, Cirano J. [Departamento de Bioquímica e Biologia Molecular, Instituo de Ciências Biológicas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970 Goiânia, GO (Brazil); García-Ruiz, Pedro A. [Grupo de Química de Carbohidratos y Biotecnología de Alimentos (QCBA), Departamento de Química Orgánica, Facultad de Química, Universidad de Murcia, E-30100 Espinardo, Murcia (Spain)

    2013-07-01

    In this study, cell wall degrading enzymes produced by Thrichoderma asperellum (TCWDE) were immobilized on totally cinnamoylated D-sorbitol (TCNSO) beads and used for chitin hydrolysis. In order to optimize immobilization efficiency, the reaction time was varied from 2 to 12 h and reactions were conducted in the presence or absence of Na{sub 2}SO{sub 4}. Immobilized enzymes were analysed concerning to thermal and operational stability. Immobilization in presence of Na{sub 2}SO{sub 4} was 54% more efficient than immobilization in absence of salt. After optimization, 32% of the total enzyme offered was immobilized, with 100% of bounding efficiency, measured as the relation between protein and enzyme immobilized. Free and TCNSO–TCWDE presented very similar kinetics with maximum hydrolysis reached at 90 min of reaction. Thermal stability of both free and TCNSO–TCWDE was similar, with losses in activity after 55 °C. Moreover, free and TCNSO–TCWDE retained 100% activity after 3 h incubation at 55 °C. TCNSO–TCWDE were used in a bath-wise reactor during 14 cycles, producing 1825 μg of N-acetylglucosamine (NAG) maintaining 83% of initial activity. - Highlights: • TCWDE immobilized on TCNSO, a support with highly hydrophobic character • New immobilization strategy for immobilization on a hydrophobic support • TCNSO–TCWDE were retained during washes and during incubation at 55 °C for 3 h.

  17. Sol-gel method for encapsulating molecules

    Science.gov (United States)

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

    2002-01-01

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

  18. The status of molecules

    International Nuclear Information System (INIS)

    Barnes, T.; Oak Ridge National Lab., TN; Tennessee Univ., Knoxville, TN

    1994-06-01

    This report summarizes the experimental and theoretical status of hadronic molecules, which are weakly-bound states of two or more hadrons. We begin with a brief history of the subject and discuss a few good candidates, and then abstract some signatures for molecules which may be of interest in the classification of possible molecule states. Next we argue that a more general understanding of 2 → 2 hadron-hadron scattering amplitudes will be crucial for molecule searches, and discuss some of our recent work in this area. We conclude with a discussion of a few more recent molecule candidates (notably the f o (1710)) which are not well established as molecules but satisfy some of the expected signatures. (Author)

  19. Cold Rydberg molecules

    Science.gov (United States)

    Raithel, Georg; Zhao, Jianming

    2017-04-01

    Cold atomic systems have opened new frontiers at the interface of atomic and molecular physics. These include research on novel types of Rydberg molecules. Three types of molecules will be reviewed. Long-range, homonuclear Rydberg molecules, first predicted in [1] and observed in [2], are formed via low-energy electron scattering of the Rydberg electron from a ground-state atom within the Rydberg atom's volume. The binding mostly arises from S- and P-wave triplet scattering. We use a Fermi model that includes S-wave and P-wave singlet and triplet scattering, the fine structure coupling of the Rydberg atom and the hyperfine structure coupling of the 5S1/2 atom (in rubidium [3]). The hyperfine structure gives rise to mixed singlet-triplet potentials for both low-L and high-L Rydberg molecules [3]. A classification into Hund's cases [3, 4, 5] will be discussed. The talk further includes results on adiabatic potentials and adiabatic states of Rydberg-Rydberg molecules in Rb and Cs. These molecules, which have even larger bonding length than Rydberg-ground molecules, are formed via electrostatic multipole interactions. The leading interaction term of neutral Rydberg-Rydberg molecules is between two dipoles, while for ionic Rydberg molecules it is between a dipole and a monopole. NSF (PHY-1506093), NNSF of China (61475123).

  20. Variações do conteúdo de glucose, frutose e sorbitol em gemas e ramos de macieira durante a dormência Variations of glucose, frutose and sorbitol content in buds and stems of apple tree during the dormancy period

    Directory of Open Access Journals (Sweden)

    Ruy Inacio Neiva de Carvalho

    2006-12-01

    Full Text Available O objetivo deste trabalho foi determinar as variações do conteúdo de glucose, frutose e sorbitol em gemas e ramos de um ano de macieira durante o período de dormência. Os ramos da cultivar "Imperial Gala" foram coletados em Porto Amazonas-PR, em intervalos de 21 dias, de abril a agosto (19/04, 10/05, 31/05, 21/06, 12/07, 02/08 e 23/08, e receberam ou não tratamento com frio suplementar de 1.440 horas à temperatura de 4 a 7°C. As análises dos carboidratos foram realizadas em gemas e porções de ramos adjacentes às primeiras por cromatografia líquida de alta eficiência (HPLC. Ocorreu um acúmulo de glucose, frutose e sorbitol nas gemas de macieira durante a dormência. O acúmulo de glucose e frutose nos ramos aconteceu até o início de agosto quando, em seguida, houve redução, enquanto o sorbitol decresceu até junho e, em seguida, elevou-se até o final de agosto. O tratamento com frio ao longo da dormência modificou as variações dos conteúdos de carboidratos nas gemas e ramos de macieira.This research was aimed at evaluating the variations of glucose, frutose and sorbitol content in one year old buds and stems of apple trees during the dormancy period. The stems of cv. Imperial Gala were collected in Porto Amazonas, Parana State, Brazil, at intervals of 21 days from April to August (April 19th, May 10th, May 31st, June 21st, July 12th, August 2nd and August 23rd and were treated or not with 1,440 hours of chill (4 to 7°C. The carbohydrates were analysed in buds and stem tissues close to buds by high performance liquid chromatography (HPLC. There was an increase of glucose, frutose and sorbitol content in apple tree buds during the dormancy. An increase of glucose and frutose content in stems occured until August 2nd followed by a significative reduction, while the sorbitol content decreased until June 21st followed by an increase until August 31st. The chill treatment during the dormancy period modified the variations of

  1. Transparent and Highly Responsive Phototransistors Based on a Solution-Processed, Nanometers-Thick Active Layer, Embedding a High-Mobility Electron-Transporting Polymer and a Hole-Trapping Molecule.

    Science.gov (United States)

    Caranzi, Lorenzo; Pace, Giuseppina; Sassi, Mauro; Beverina, Luca; Caironi, Mario

    2017-08-30

    Organic materials are suitable for light sensing devices showing unique features such as low cost, large area, and flexibility. Moreover, transparent photodetectors are interesting for smart interfaces, windows, and display-integrated electronics. The ease of depositing ultrathin organic films with simple techniques enables low light absorbing active layers, resulting in the realization of transparent devices. Here, we demonstrate a strategy to obtain high efficiency organic photodetectors and phototransistors based on transparent active layers with a visible transmittance higher than 90%. The photoactive layer is composed of two phases, each a few nanometers thick. First, an acceptor polymer, which is a good electron-transporting material, on top of which a small molecule donor material is deposited, forming noncontinuous domains. The small molecule phase acts as a trap for holes, thus inducing a high photoconductive gain, resulting in a high photoresponsivity. The organic transparent detectors proposed here can reach very high external quantum efficiency and responsivity values, which in the case of the phototransistors can be as high as ∼74000% and 340 A W -1 at 570 nm respectively, despite an absorber total thickness below 10 nm. Moreover, frequency dependent 2D photocurrent mapping allows discrimination between the contribution of a fast but inefficient and highly spatially localized photoinduced injection mechanism at the electrodes, and the onset of a slower and spatially extended photoconductive process, leading to high responsivity.

  2. Molecule of the Month

    Indian Academy of Sciences (India)

    Atoms in a molecule generally prefer, particularly among the neighbouring ones, certain optimmn geometrical relationships. These are manifested in specific ranges of bond lengths, bond angles, torsion angles etc. As it always happens, chemists are interested in making molecules where these 'standard relationships' are ...

  3. Molecule of the Month

    Indian Academy of Sciences (India)

    Cyclo bu tadiene (1) has been one of the most popular molecules for experimentalists and theoreticians. This molecule is unstable as . it is antiaromatic ( 4,n electrons in a cyclic array). Even though some highly substituted cyclobutadienes, for example, compound 2 and the Fe(CO)3 complex of cyclobutadiene (3) are ...

  4. Single-Molecule Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 2. Single-Molecule Spectroscopy: Every Molecule is Different! Kankan Bhattacharyya. General Article Volume 20 Issue 2 February 2015 pp 151-164. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Single molecule conductance

    NARCIS (Netherlands)

    Willems, R.

    2008-01-01

    This thesis represents an excursion into the world of molecular electronics, i.e. the field of research trying to use individual (organic) molecules as electronic components; in this work various experimental methods have been explored to connect individual molecules to metallic contacts and

  6. Molecules in stars

    International Nuclear Information System (INIS)

    Tsuji, T.

    1986-01-01

    Recently, research related to molecules in stars has rapidly expanded because of progress in related fields. For this reason, it is almost impossible to cover all the topics related to molecules in stars. Thus, here the authors focus their attention on molecules in the atmospheres of cool stars and do not cover in any detail topics related to circumstellar molecules originating from expanding envelopes located far from the stellar surface. However, the authors do discuss molecules in quasi-static circumstellar envelopes (a recently discovered new component of circumstellar envelopes) located near the stellar surface, since molecular lines originating from such envelopes show little velocity shift relative to photospheric lines, and hence they directly affect the interpretation and analysis of stellar spectra

  7. Effect of cephalandra indica against advanced glycation end products, sorbitol accumulation and aldose reductase activity in homoeopathic formulation

    Directory of Open Access Journals (Sweden)

    Lalit Kishore

    2018-01-01

    Full Text Available Background: Extreme generation of free radicals leads to oxidative stress which has been apprehensive in several disease processes such as diabetic complications and vascular and neurodegenerative diseases. Objective: The present study was designed to evaluate the potential of homoeopathic preparations of Cephalandra indica L. against oxidative stress. Materials and Methods: Potencies of Cephalandra indica (mother tincture, 6C and 30C were procured from Dr. Willmar Schwabe India Pvt. Ltd. The antioxidant activity of Cephalandra indica was evaluated by employing various in vitro antioxidant methods. Results: The total phenol content was found to be 1905, 849 and 495 mg/g gallic acid equivalents in mother tincture, 6C and 30C of Cephalandra indica and total antioxidant capacity was found to be 2710, 759 and 510 μM/g ascorbic acid equivalents, respectively. Mother tincture, 6C and 30C of Cephalandra indica was found to have strong reducing power, 2,2-diphenyl-1-picrylhydrazyl radical, hydrogen peroxide, nitric oxide and superoxide radical scavenging activity. Percentage inhibition of AGEs formation by mother tincture, 6C and 30C of Cephalandra indica (10–50 μl was found to be 30.34%–91.77%, 29.98%–65.71% and 33.05%–57.75%, respectively. Mother tincture, 6C and 30C of Cephalandra indica showed inhibitory effect against sorbitol accumulation with IC50value of 26.12 μl, 203.10 μl and 897.3 μl, respectively, whereas, in aldose reductase inhibition assay, the IC50value was 32.54 μl, 175.02 μl and 834.34 μl, respectively. Conclusion: The results revealed that homoeopathic preparations of Cephalandra indica exhibit protective effect against oxidative stress.

  8. Approach to corrosion mechanisms for a carbon steel in a solution of sodium chloride at 3 pc and its inhibition by means of organic molecules. Compared benefit of the use of stationary and transient electrochemical methods

    International Nuclear Information System (INIS)

    Duprat, Michel

    1981-01-01

    Within the context of an increased use of seawater as coolant in various industrial installations, this research thesis had two main objectives: the search for inhibitor organic compounds with optimal efficiency, and a better understanding of the mechanisms of corrosion inhibition by the best compounds within the considered organic compounds. After having reported a bibliographical study on carbon steel corrosion in seawater or in a sodium chloride solution at 3 pc, and on the inhibition of this corrosion, the author presents the experimental conditions (materials and methods). He reports the use of stationary and un-stationary electrochemical methods for the study of the steel-solution interface without inhibitor in order to get a better knowledge of corrosion electrochemical processes and to determine more precisely the corrosion rate. The last part addresses the study of the same interface but in presence of various inhibitors

  9. Influence of methanol/sorbitol co-feeding rate on pAOX1 induction in a Pichia pastoris Mut+ strain in bioreactor with limited oxygen transfer rate.

    Science.gov (United States)

    Carly, F; Niu, H; Delvigne, F; Fickers, P

    2016-04-01

    High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen limitation in bioreactor. In the literature, there is lack of report about AOX1 promoter regulation with regard to dissolved oxygen level (DO). Therefore, in this work, chemostat cultures were performed to investigate the cell growth, metabolism and regulation of the AOX1 promoter (pAOX1) regarding co-feeding rate of optimized methanol/sorbitol mixture (methanol fraction 0.60 C-mol/C-mol) using a P. pastoris Mut+/pAOX1-lacZ strain. The oxygen transfer rates (OTR) in bioreactor were kept in the range of typical values of large bioreactor, i.e., 4-8 g/(L h) if DO equals 30 % saturation or 5-10 g/(L h) if DO nears zero. For DO >0, an increase of the carbon fed led to an increase of pAOX1 induction. By contrast, when dissolved oxygen was completely depleted, methanol accumulated, causing a 30 % decrease of pAOX1 induction. However, this decrease is more likely to be lined to methanol accumulation than to low level of dissolved oxygen (sorbitol co-feeding allowed cells to adapt to oxygen transient limitations that often occur at industrial scale with reduced effect on pAOX1 induction. The optimal feeding rate tested here was 6.6 mmol C (DCW h)(-1) at an OTR of 8.28 g O2(L h)(-1) with over fivefold pAOX1 induction (probably directly associated with target protein productivity) compared with previous work.

  10. Preparation and properties of 1-tetradecanol/1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol gelatinous form-stable phase change materials

    International Nuclear Information System (INIS)

    Tian, Tuo; Song, Jian; Niu, Libo; Feng, Rongxiu

    2013-01-01

    Graphical abstract: The 1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol can self-assemble to form three-dimensional network and immobilized the 1-tetradecanol. As a result, the gel-to-sol transition temperature of the composite PCM increased and the 1-tetradecanol leakage decreased. Highlights: ► First used of 1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol in alcohol-based PCMs. ► A new method of doping with exfoliated graphite is presented. ► A possible mechanism for decreasing leakage has been proposed based on SEM results. ► The prepared composite PCMs showed a high-energy storage density. ► The addition of exfoliated graphite enhanced the thermal conductivity of the PCMs. - Abstract: A 1-tetradecanol (TD)/1,3:2,4-di-(3,4-dimethyl) benzylidene sorbitol (DMDBS) composite was prepared as a novel form-stable phase change material (PCM), and the properties of the composites such as the gel-to-sol transition temperature, the latent heat, the microstructure and the thermal storage performance were characterized. The composite was prepared by impregnating DMDBS into TD and the maximum feasible weight percentage of TD was determined to be 94.2 wt%. The gel-to-sol transition temperature of the composite PCM was 158.3–180.0 °C, which is well above the melting point of 1-tetradecanol. Differential scanning calorimeter (DSC) was used to determine the melting and freezing enthalpies of 1-tetradecanol in the composite PCM and the values are 218.5 and 215.3 J g −1 , respectively. Scanning electron microscopy (SEM) results showed that 1-tetradecanol dispersed in the three-dimensional network formed by DMDBS. The relationship between the amount of DMDBS additive and the leakage was also discussed. The thermal conductivity of the composite PCM was improved by doping with exfoliated graphite

  11. Association of prescription of oral sodium polystyrene sulfonate with sorbitol in an inpatient setting with colonic necrosis: a retrospective cohort study.

    Science.gov (United States)

    Watson, Maura A; Baker, Thomas P; Nguyen, Annie; Sebastianelli, Mary E; Stewart, Heather L; Oliver, David K; Abbott, Kevin C; Yuan, Christina M

    2012-09-01

    Colonic necrosis has been reported after sodium polystyrene sulfonate (SPS)/sorbitol use, but the incidence and relative risk (RR) are not established. Retrospective cohort study. 123,391 adult inpatients at a tertiary medical center. Receipt of SPS prescriptions (exposed) or a prescription other than SPS (unexposed internal comparison group) between September 1, 2001, and October 31, 2010. The main outcome measure was tissue-confirmed diagnosis of colonic necrosis, considered SPS-associated if SPS was prescribed 30 or fewer days before tissue accession date. Demographics, serum chemistry test results, hospital location, and International Classification of Diseases, Ninth Revision diagnostic codes. SPS was prescribed to 2,194 inpatients. 82 inpatient colonic necrosis cases were identified. 3 received oral SPS (1 gram per 4 milliliters of 33% sorbitol) 30 or fewer days before the colonic necrosis accession date (3.7% of inpatient colonic necrosis cases). The data were linked with 123,391 individuals who received inpatient prescriptions between the same dates. Colonic necrosis incidence was 0.14% (95% CI, 0.03%-0.40%) in those prescribed SPS versus 0.07% (95% CI, 0.05-0.08%) in those not prescribed SPS (RR, 2.10; 95% CI, 0.68-6.48; P = 0.2). The number needed to harm was 1,395 (95% CI, 298-5,100). Subgroup analysis (age >65 years; estimated glomerular filtration rate, sorbitol prescription was not associated significantly with an increased RR of colonic necrosis in this retrospective cohort analysis. Multivariate analysis would require retrospective clinical cohorts from larger or more than one hospital system(s). Published by Elsevier Inc.

  12. Dynamics of Activated Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, Amy S. [Univ. of Maryland, College Park, MD (United States)

    2016-11-16

    Experimental studies have been performed to investigate the collisional energy transfer processes of gas-phase molecules that contain large amounts of internal energy. Such molecules are prototypes for molecules under high temperature conditions relevant in combustion and information about their energy transfer mechanisms is needed for a detailed understanding and modeling of the chemistry. We use high resolution transient IR absorption spectroscopy to measure the full, nascent product distributions for collisions of small bath molecules that relax highly vibrationally excited pyrazine molecules with E=38000 cm-1 of vibrational energy. To perform these studies, we developed new instrumentation based on modern IR light sources to expand our experimental capabilities to investigate new molecules as collision partners. This final report describes our research in four areas: the characterization of a new transient absorption spectrometer and the results of state-resolved collision studies of pyrazine(E) with HCl, methane and ammonia. Through this research we have gained fundamental new insights into the microscopic details of relatively large complex molecules at high energy as they undergo quenching collisions and redistribute their energy.

  13. Hierarchical organization in aggregates of protein molecules

    DEFF Research Database (Denmark)

    Bohr, Henrik; Kyhle, Anders; Sørensen, Alexis Hammer

    1997-01-01

    of the solution and the density of protein are varied shows the existence of specific growth processes resulting in different branch-like structures. The resulting structures are strongly influenced by the shape of each protein molecule. Lysozyme and ribonuclease are found to form spherical structures...

  14. Dissociation in small molecules

    International Nuclear Information System (INIS)

    Dehmer, P.M.

    1982-01-01

    The study of molecular dissociation processes is one of the most interesting areas of modern spectroscopy owing to the challenges presented bt even the simplest of diatomic molecules. This paper reviews the commonly used descriptions of molecular dissociation processes for diatomic molecules, the selection rules for predissociation, and a few of the principles to be remembered when one is forced to speculate about dissociation mechanisms in a new molecule. Some of these points will be illustrated by the example of dissociative ionization in O 2

  15. MATHEMATICAL MODELING, AUTOMATION AND CONTROL OF THE BIOCONVERSION OF SORBITOL TO SORBOSE IN THE VITAMIN C PRODUCTION PROCESS I. MATHEMATICAL MODELING

    Directory of Open Access Journals (Sweden)

    A. Bonomi

    1997-12-01

    Full Text Available In 1990, the Biotechnology and the Control Systems Groups of IPT started developing a system for the control and automation of fermentation processes, applied to the oxidation of sorbitol to sorbose by the bacteria Gluconobacter oxydans, the microbial step of the vitamin C production process, that was chosen as a case study. Initially, a thirteen-parameter model was fitted to represent the batch operation of the system utilizing a nonlinear regression analysis, the flexible polyhedron method. Based on these results, a model for the continuous process (with the same kinetic equations was constructed and its optimum operating point obtained

  16. Coherent Bichromatic Force Deflection of Molecules

    Science.gov (United States)

    Kozyryev, Ivan; Baum, Louis; Aldridge, Leland; Yu, Phelan; Eyler, Edward E.; Doyle, John M.

    2018-02-01

    We demonstrate the effect of the coherent optical bichromatic force on a molecule, the polar free radical strontium monohydroxide (SrOH). A dual-frequency retroreflected laser beam addressing the X˜2Σ+↔A˜2Π1 /2 electronic transition coherently imparts momentum onto a cryogenic beam of SrOH. This directional photon exchange creates a bichromatic force that transversely deflects the molecules. By adjusting the relative phase between the forward and counterpropagating laser beams we reverse the direction of the applied force. A momentum transfer of 70 ℏk is achieved with minimal loss of molecules to dark states. Modeling of the bichromatic force is performed via direct numerical solution of the time-dependent density matrix and is compared with experimental observations. Our results open the door to further coherent manipulation of molecular motion, including the efficient optical deceleration of diatomic and polyatomic molecules with complex level structures.

  17. Single molecules and nanotechnology

    CERN Document Server

    Vogel, Horst

    2007-01-01

    This book focuses on recent advances in the rapidly evolving field of single molecule research. These advances are of importance for the investigation of biopolymers and cellular biochemical reactions, and are essential to the development of quantitative biology. Written by leading experts in the field, the articles cover a broad range of topics, including: quantum photonics of organic dyes and inorganic nanoparticles their use in detecting properties of single molecules the monitoring of single molecule (enzymatic) reactions single protein (un)folding in nanometer-sized confined volumes the dynamics of molecular interactions in biological cells The book is written for advanced students and scientists who wish to survey the concepts, techniques and results of single molecule research and assess them for their own scientific activities.

  18. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  19. Molecules to Materials

    Indian Academy of Sciences (India)

    evolved as a new line of thinking wherein a single molecule or perhaps a collection .... In photonic communication processes, laser light has to be modulated and .... The author wishes to thank G Rajaram for a critical reading of the manuscript.

  20. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  1. Molecule of the Month

    Indian Academy of Sciences (India)

    Molecule of the Month - Adamantane - A Plastic Piece of Diamond. J Chandrasekhar. Volume 16 Issue 12 ... Keywords. Adamantane; diamondoid systems; plastic crystals. ... Resonance – Journal of Science Education | News. © 2017 Indian ...

  2. Theoretical study of intermolecular energy transfer involving electronically excited molecules: He(/sup 1/S) + H/sub 2/(B /sup 1/. sigma. /sub u//sup +/). [Solution for coupled channel equations

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, R.M.

    1986-11-01

    To further understanding of gas phase collision dynamics involving electronically-excited molecules, a fully quantum mechanical study of He + H/sub 2/(B /sup 1/..sigma../sub u//sup +/) was undertaken. Iterative natural orbital configuration interaction (CI) calculations were performed to obtain the interaction potential between He and H/sub 2/(B /sup 1/..sigma../sub u//sup +/). The potential energy surface (PES) is highly anisotropic and has a van der Waals well of about 0.03 eV for C/sub 2v/ approach. Avoided PES crossings occur with He + H/sub 2/(E,F /sup 1/..sigma../sub g//sup +/) and with He + H/sub 2/(X /sup 1/..sigma../sub g//sup +/) and cause a local maximum and a deep minimum in the He + H/sub 2/(B /sup 1/..sigma../sub u//sup +/) PES, respectively. The crossing with He + H/sub 2/(X /sup 1/..sigma../sub g//sup +/) provides a mechanism for fluorescence quenching. The computed CI energies were combined with previous multi-reference double excitation CI calculations and fit with analytic functions for convenience in scattering calculations. Accurate dipole polarizabilities and quadrupole moment of H/sub 2/(B /sup 1/..sigma../sub u//sup +/) were computed for use in the multipole expansion, which is the analytic form of the long-range PES. 129 refs., 28 figs., 35 tabs.

  3. Quantitative real-time PCR as a sensitive protein-protein interaction quantification method and a partial solution for non-accessible autoactivator and false-negative molecule analysis in the yeast two-hybrid system.

    Science.gov (United States)

    Maier, Richard H; Maier, Christina J; Hintner, Helmut; Bauer, Johann W; Onder, Kamil

    2012-12-01

    Many functional proteomic experiments make use of high-throughput technologies such as mass spectrometry combined with two-dimensional polyacrylamide gel electrophoresis and the yeast two-hybrid (Y2H) system. Currently there are even automated versions of the Y2H system available that can be used for proteome-wide research. The Y2H system has the capacity to deliver a profusion of Y2H positive colonies from a single library screen. However, subsequent analysis of these numerous primary candidates with complementary methods can be overwhelming. Therefore, a method to select the most promising candidates with strong interaction properties might be useful to reduce the number of candidates requiring further analysis. The method described here offers a new way of quantifying and rating the performance of positive Y2H candidates. The novelty lies in the detection and measurement of mRNA expression instead of proteins or conventional Y2H genetic reporters. This method correlates well with the direct genetic reporter readouts usually used in the Y2H system, and has greater sensitivity for detecting and quantifying protein-protein interactions (PPIs) than the conventional Y2H system, as demonstrated by detection of the Y2H false-negative PPI of RXR/PPARG. Approximately 20% of all proteins are not suitable for the Y2H system, the so-called autoactivators. A further advantage of this method is the possibility to evaluate molecules that usually cannot be analyzed in the Y2H system, exemplified by a VDR-LXXLL motif peptide interaction. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Single molecule microscopy and spectroscopy: concluding remarks.

    Science.gov (United States)

    van Hulst, Niek F

    2015-01-01

    Chemistry is all about molecules: control, synthesis, interaction and reaction of molecules. All too easily on a blackboard, one draws molecules, their structures and dynamics, to create an insightful picture. The dream is to see these molecules in reality. This is exactly what "Single Molecule Detection" provides: a look at molecules in action at ambient conditions; a breakthrough technology in chemistry, physics and biology. Within the realms of the Royal Society of Chemistry, the Faraday Discussion on "Single Molecule Microscopy and Spectroscopy" was a very appropriate topic for presentation, deliberation and debate. Undoubtedly, the Faraday Discussions have a splendid reputation in stimulating scientific debates along the traditions set by Michael Faraday. Interestingly, back in the 1830's, Faraday himself pursued an experiment that led to the idea that atoms in a compound were joined by an electrical component. He placed two opposite electrodes in a solution of water containing a dissolved compound, and observed that one of the elements of the compound accumulated on one electrode, while the other was deposited on the opposite electrode. Although Faraday was deeply opposed to atomism, he had to recognize that electrical forces were responsible for the joining of atoms. Probably a direct view on the atoms or molecules in his experiment would have convinced him. As such, Michael Faraday might have liked the gathering at Burlington House in September 2015 (). Surely, with the questioning eyes of his bust on the 1st floor corridor, the non-believer Michael Faraday has incited each passer-by to enter into discussion and search for deeper answers at the level of single molecules. In these concluding remarks, highlights of the presented papers and discussions are summarized, complemented by a conclusion on future perspectives.

  5. The role of the ion-molecule and molecule-molecule interactions in the formation of the two-ion average force interaction potential

    CERN Document Server

    Ajrian, E A; Sidorenko, S N

    2002-01-01

    The effect of the ion-molecule and intermolecular interactions on the formation of inter-ion average force potentials is investigated within the framework of a classical ion-dipole model of electrolyte solutions. These potentials are shown to possess the Coulomb asymptotics at large distances while in the region of mean distances they reveal creation and disintegration of solvent-shared ion pairs. The calculation results provide a qualitatively authentic physical picture which is experimentally observed in strong electrolytes solutions. In particular, an increased interaction between an ion and a molecule enhances formation of ion pairs in which the ions are separated by one solvent molecule

  6. Radiolysis of carbohydrates as studied by ESR and spin-trapping—II. Glycerol- d8 xylitol, dulcitol, d-sorbitol and d-mannitol

    Science.gov (United States)

    Kuwabara, M.; Zhang, Z.-Y.; Inanami, O.; Yoshii, G.

    Studies concerning the radicals produced in glycerol by reactions with OH radicals have been carried out by investigating deuterated glycerol (glycerol-d 8) by spin-trapping with 2-methyl-2-nitrosopropane. Free radicals produced in linear carbohydrates such as xylitol, dulcitol, D-sorbitol and D-mannitol by reactions with OH radicals as well as by direct γ-radiolysis have been also investigated by spin-trapping. The ESR spectra of the spin-trapped radicals were analysed on the basis of the results from ESR and spin-trapping experiments on glycerol and deuterated glycerol, and the formation of three radical species, CHO-CH-, CH 2-CO- and HO-CH-, due to both OH reactions and direct γ-radiolysis was confirmed for all compounds. The presence of a radical, -CO-CH-, was detected for xylitol, D-sorbitol and D-mannitol. General reactions processes induced by OH reactions or γ-radiolysis in the solid state are discussed.

  7. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation.

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-07-10

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Enhanced porcine circovirus Cap protein production by Pichia pastoris with a fuzzy logic DO control based methanol/sorbitol co-feeding induction strategy.

    Science.gov (United States)

    Ding, Jian; Zhang, Chunling; Gao, Minjie; Hou, Guoli; Liang, Kexue; Li, Chunhua; Ni, Jianping; Li, Zhen; Shi, Zhongping

    2014-05-10

    Porcine circovirus Cap protein production by P. pastoris with strong AOX promoter suffered with the problems with traditional pure methanol induction: (1) inefficient methanol metabolism; (2) extensive oxygen supply load; (3) difficulty in stable DO control; (4) low protein titer. In this study, based on the difference of DO change patterns in response to methanol and sorbitol additions, a novel fuzzy control system was proposed to automatically regulate the co-feeding rates of methanol and sorbitol for efficient Cap protein induction. With aid of the proposed control system when setting DO control level at 10%, overall fermentation performance was significantly improved: (1) DO could be stably controlled under mild aeration condition; (2) methanol consumption rate could be restricted at moderate level and the major enzymes involved with methanol metabolism were largely activated; (3) Cap protein concentration reached a highest level of 198mg/L, which was about 64% increase over the best one using the pure methanol induction strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation*

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-01-01

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. PMID:25998127

  10. A comparative study of glycerol and sorbitol as co-substrates in methanol-induced cultures of Pichia pastoris: temperature effect and scale-up simulation.

    Science.gov (United States)

    Berrios, Julio; Flores, María-Olga; Díaz-Barrera, Alvaro; Altamirano, Claudia; Martínez, Irene; Cabrera, Zaida

    2017-03-01

    The production of recombinant proteins by Pichia pastoris under AOX1 promoter is usually performed using methanol together with either glycerol or sorbitol as co-substrate. Although both co-substrates have been widely used, comparative studies are scarce. In addition, these comparisons have been performed at different specific growth rate (µ) that it is well known that has an important effect on productivity. Thus, the effect of using these co-substrates on the production of Rhyzopus oryzae lipase (ROL) by P. pastoris was compared in continuous cultures growing at the same µ at either 22 or 30 °C. Results show that using glycerol as co-substrate led to higher volumetric productivities, and lower specific and volumetric methanol consumption rates. Scale-up simulation with 10-10,000 L bioreactor sizes indicated that glycerol produced the highest volumetric productivity of ROL with lower aeration requirements. Therefore, glycerol rises as a better option than sorbitol in ROL production.

  11. Electron-molecule collisions

    International Nuclear Information System (INIS)

    Shimamura, I.; Takayanagi, K.

    1984-01-01

    The study of collision processes plays an important research role in modern physics. Many significant discoveries have been made by means of collision experiments. Based on theoretical, experimental, and computational studies, this volume presents an overview detailing the basic processes of electron-molecule collisions. The editors have collected papers-written by a group of international experts-that consider a diverse range of phenomena occurring in electronmolecule collisions. The volume discusses first the basic formulation for scattering problems and then gives an outline of the physics of electron-molecule collisions. The main topics covered are rotational transitions, vibrational transitions, dissociation of molecules in slow collisions, the electron-molecule collision as a spectroscopic tool for studying molecular electronic structures, and experimental and computational techniques for determining the cross sections. These well-referenced chapters are self-contained and can be read independently or consecutively. Authoritative and up-to-date, Electron-Molecule Collisions is a useful addition to the libraries of students and researchers in the fields of atomic, molecular, and chemical physics, and physical chemistry

  12. New Directions of Research in Molecules and Materials

    Indian Academy of Sciences (India)

    Wintec

    New Directions of Research in Molecules and Materials. Foreword. 'Materials' has ... Solution phase chemistry is a central aspect of materials as demonstrated by. Panchakarla and ... Changes at the atomic scale affect bulk properties such as ...

  13. Freezing-induced self-assembly of amphiphilic molecules

    Science.gov (United States)

    Albouy, P. A.; Deville, S.; Fulkar, A.; Hakouk, K.; Impéror-Clerc, M.; Klotz, M.; Liu, Q.; Marcellini, M.; Perez, J.

    The self-assembly of amphiphilic molecules usually takes place in a liquid phase, near room temperature. Here, using small angle X-ray scattering (SAXS) experiments performed in real time, we show that freezing of aqueous solutions of copolymer amphiphilic molecules can induce self-assembly below 0{\\deg}C.

  14. MOLECULES IN η CARINAE

    International Nuclear Information System (INIS)

    Loinard, Laurent; Menten, Karl M.; Güsten, Rolf; Zapata, Luis A.; Rodríguez, Luis F.

    2012-01-01

    We report the detection toward η Carinae of six new molecules, CO, CN, HCO + , HCN, HNC, and N 2 H + , and of two of their less abundant isotopic counterparts, 13 CO and H 13 CN. The line profiles are moderately broad (∼100 km s –1 ), indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO + do not appear to be underabundant in η Carinae. On the other hand, molecules containing nitrogen or the 13 C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of η Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  15. A Circularly Arranged Sextuple Triptycene Gear Molecule.

    Science.gov (United States)

    Ube, Hitoshi; Yamada, Ryo; Ishida, Jun-Ichi; Sato, Hiroyasu; Shiro, Motoo; Shionoya, Mitsuhiko

    2017-11-22

    Herein we report the synthesis of a circularly arranged sextuple triptycene gear molecule, hexakis(10-dodecyloxy-9-triptycyl)ethynylbenzene, via the trimerization of the corresponding triyne with a cobalt catalyst. The six triptycene gears are closely engaged with each other as confirmed by single crystal X-ray structure analysis, and their motion in solution was established by NMR spectroscopy. Notably, when one bulky RuCp* complex was attached to one triptycene gear, the whole movement of the six gears was highly restricted via their mechanical engagement. Development of such a multigear molecule would provide a structural basis for molecular motion transmission systems with a switching function.

  16. Nanoscale methods for single-molecule electrochemistry.

    Science.gov (United States)

    Mathwig, Klaus; Aartsma, Thijs J; Canters, Gerard W; Lemay, Serge G

    2014-01-01

    The development of experiments capable of probing individual molecules has led to major breakthroughs in fields ranging from molecular electronics to biophysics, allowing direct tests of knowledge derived from macroscopic measurements and enabling new assays that probe population heterogeneities and internal molecular dynamics. Although still somewhat in their infancy, such methods are also being developed for probing molecular systems in solution using electrochemical transduction mechanisms. Here we outline the present status of this emerging field, concentrating in particular on optical methods, metal-molecule-metal junctions, and electrochemical nanofluidic devices.

  17. Formation of an Ion-Pair Molecule with a Single NH+...Cl- Hydrogen Bond: Raman spectra of 1,1,3,3-Tetramethylguanidinium chloride in the solid state, in solution and in the vapor phase

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Riisager, Anders; Fehrmann, Rasmus

    2008-01-01

    Some ionic compounds (salts) form liquids when heated to temperatures in the range of 200-300 °C. They may be referred to as moderate temperature ionic liquids. An example of such a compound is the 1,1,3,3- tetramethylguanidinium chloride, [TMGH]Cl, melting at ∼212 °C. The chemistry of this compo......Some ionic compounds (salts) form liquids when heated to temperatures in the range of 200-300 °C. They may be referred to as moderate temperature ionic liquids. An example of such a compound is the 1,1,3,3- tetramethylguanidinium chloride, [TMGH]Cl, melting at ∼212 °C. The chemistry...... and the dimeric chloride ion-pair salt converged to give geometries near the established crystal structure of [TMGH]Cl. The structures and their binding energies are given as well as calculated vibrational harmonic normal modes (IR and Raman band wavenumbers and intensities). Experimentally obtained Raman...... scattering spectra are presented and assigned, by comparing to the quantum mechanical calculations. It is concluded that dimeric molecular ion pairs with four N-H+ · · · Cl- hydrogen bonds probably exist in the solutions and are responsible for the relatively high solubility of the “salt” in ethanol...

  18. Electron Accumulative Molecules.

    Science.gov (United States)

    Buades, Ana B; Sanchez Arderiu, Víctor; Olid-Britos, David; Viñas, Clara; Sillanpää, Reijo; Haukka, Matti; Fontrodona, Xavier; Paradinas, Markos; Ocal, Carmen; Teixidor, Francesc

    2018-02-28

    With the goal to produce molecules with high electron accepting capacity and low reorganization energy upon gaining one or more electrons, a synthesis procedure leading to the formation of a B-N(aromatic) bond in a cluster has been developed. The research was focused on the development of a molecular structure able to accept and release a specific number of electrons without decomposing or change in its structural arrangement. The synthetic procedure consists of a parallel decomposition reaction to generate a reactive electrophile and a synthesis reaction to generate the B-N(aromatic) bond. This procedure has paved the way to produce the metallacarboranylviologen [M(C 2 B 9 H 11 )(C 2 B 9 H 10 )-NC 5 H 4 -C 5 H 4 N-M'(C 2 B 9 H 11 )(C 2 B 9 H 10 )] (M = M' = Co, Fe and M = Co and M' = Fe) and semi(metallacarboranyl)viologen [3,3'-M(8-(NC 5 H 4 -C 5 H 4 N-1,2-C 2 B 9 H 10 )(1',2'-C 2 B 9 H 11 )] (M = Co, Fe) electron cumulative molecules. These molecules are able to accept up to five electrons and to donate one in single electron steps at accessible potentials and in a reversible way. By targeted synthesis and corresponding electrochemical tests each electron transfer (ET) step has been assigned to specific fragments of the molecules. The molecules have been carefully characterized, and the electronic communication between both metal centers (when this situation applies) has been definitely observed through the coplanarity of both pyridine fragments. The structural characteristics of these molecules imply a low reorganization energy that is a necessary requirement for low energy ET processes. This makes them electronically comparable to fullerenes, but on their side, they have a wide range of possible solvents. The ET from one molecule to another has been clearly demonstrated as well as their self-organizing capacity. We consider that these molecules, thanks to their easy synthesis, ET, self-organizing capacity, wide range of solubility, and easy processability, can

  19. A single amino acid change (Y318F) in the L-arabitol dehydrogenase (LadA) from Aspergillus niger results in a significant increase in affinity for D-sorbitol

    Science.gov (United States)

    2009-01-01

    Background L-arabitol dehydrogenase (LAD) and xylitol dehydrogenase (XDH) are involved in the degradation of L-arabinose and D-xylose, which are among the most abundant monosaccharides on earth. Previous data demonstrated that LAD and XDH not only differ in the activity on their biological substrate, but also that only XDH has significant activity on D-sorbitol and may therefore be more closely related to D-sorbitol dehydrogenases (SDH). In this study we aimed to identify residues involved in the difference in substrate specificity. Results Phylogenetic analysis demonstrated that LAD, XDH and SDH form 3 distinct groups of the family of dehydrogenases containing an Alcohol dehydrogenase GroES-like domain (pfam08240) and likely have evolved from a common ancestor. Modelling of LadA and XdhA of the saprobic fungus Aspergillus niger on human SDH identified two residues in LadA (M70 and Y318), that may explain the absence of activity on D-sorbitol. While introduction of the mutation M70F in LadA of A. niger resulted in a nearly complete enzyme inactivation, the Y318F resulted in increased activity for L-arabitol and xylitol. Moreover, the affinity for D-sorbitol was increased in this mutant. Conclusion These data demonstrates that Y318 of LadA contributes significantly to the substrate specificity difference between LAD and XDH/SDH. PMID:19674460

  20. Replacement of Oxygen by Sulfur in Small Organic Molecules. 3. Theoretical Studies on the Tautomeric Equilibria of the 2OH and 4OH-Substituted Oxazole and Thiazole and the 3OH and 4OH-Substituted Isoxazole and Isothiazole in the Isolated State and in Solution

    Directory of Open Access Journals (Sweden)

    Peter I. Nagy

    2016-07-01

    Full Text Available This follow-up paper completes the author’s investigations to explore the in-solution structural preferences and relative free energies of all OH-substituted oxazole, thiazole, isoxazole, and isothiazole systems. The polarizable continuum dielectric solvent method calculations in the integral-equation formalism (IEF-PCM were performed at the DFT/B97D/aug-cc-pv(q+(dz level for the stable neutral tautomers with geometries optimized in dichloromethane and aqueous solution. With the exception of the predictions for the predominant tautomers of the 3OH isoxazole and isothiazole, the results of the IEF-PCM calculations for identifying the most stable tautomer of the given species in the two selected solvents agreed with those from experimental investigations. The calculations predict that the hydroxy proton, with the exception for the 4OH isoxazole and 4OH isothiazole, moves preferentially to the ring nitrogen or to a ring carbon atom in parallel with the development of a C=O group. The remaining, low-fraction OH tautomers will not be observable in the equilibrium compositions. Relative solvation free energies obtained by the free energy perturbation method implemented in Monte Carlo simulations are in moderate accord with the IEF-PCM results, but consideration of the ΔGsolv/MC values in calculating ΔGstot maintains the tautomeric preferences. It was revealed from the Monte Carlo solution structure analyses that the S atom is not a hydrogen-bond acceptor in any OH-substituted thiazole or isothiazole, and the OH-substituted isoxazole and oxazole ring oxygens may act as a weak hydrogen-bond acceptor at most. The molecules form 1.0−3.4 solute−water hydrogen bonds in generally unexplored numbers at some specific solute sites. Nonetheless, hydrogen-bond formation is favorable with the NH, C=O and OH groups.

  1. Molecule of the Month

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Molecule of the Month Isomers of Benzene - Still Pursuing Dreams. J Chandrasekhar. Feature Article Volume 1 Issue 2 February 1996 pp 80-83. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Atoms, Molecules, and Compounds

    CERN Document Server

    Manning, Phillip

    2007-01-01

    Explores the atoms that govern chemical processes. This book shows how the interactions between simple substances such as salt and water are crucial to life on Earth and how those interactions are predestined by the atoms that make up the molecules.

  3. Electrons in Molecules

    Indian Academy of Sciences (India)

    structure and properties (includingreactivt'ty) - both static (independent of time) and ... Furthermore, since the energy of H2 + in the ground state must be lower than that of .... (Figure 2b); note also that dp is positive in parts of the antibinding regions behind the two ... But, now both the sizes and shapes of molecules enter into.

  4. Molecule of the Month

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Molecule of the Month - A Stable Dibismuthene - A Compound with a Bi-Bi Double Bond. V Chandrasekhar. Volume 16 ... Author Affiliations. V Chandrasekhar1. Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, India.

  5. OMG: Open molecule generator

    NARCIS (Netherlands)

    Peironcely, J.E.; Rojas-Chertó, M.; Fichera, D.; Reijmers, T.; Coulier, L.; Faulon, J.-L.; Hankemeier, T.

    2012-01-01

    Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG), which for a given elemental composition produces all non-isomorphic chemical

  6. Molecule-based magnets

    Indian Academy of Sciences (India)

    Administrator

    Employing self-assembly methods, it is possible to engineer a bulk molecular material ... synthesis of molecular magnets in 1986, a large variety of them have been synthesized, which can be catego- ... maintained stably per organic molecule, stabilization of a ..... rotating freely under an applied field because it is a magne-.

  7. Molecule of the Month

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 5. Molecule of the Month Molecular–Chameleon: Solvatochromism at its Iridescent Best! Photon Rao. Feature Article Volume 2 Issue 5 May 1997 pp 69-72. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Exotic helium molecules

    International Nuclear Information System (INIS)

    Portier, M.

    2007-12-01

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range 4 He 2 (2 3 S 1 -2 3 P 0 ) molecule, or a 4 He 2 (2 3 S 1 -2 3 S 1 ) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 ± 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range 4 He 2 (2 3 S 1 -2 3 S 1 ) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime τ = (1.4 ± 0.3) μs is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  9. Proteins in solution: Fractal surfaces in solutions

    Directory of Open Access Journals (Sweden)

    R. Tscheliessnig

    2016-02-01

    Full Text Available The concept of the surface of a protein in solution, as well of the interface between protein and 'bulk solution', is introduced. The experimental technique of small angle X-ray and neutron scattering is introduced and described briefly. Molecular dynamics simulation, as an appropriate computational tool for studying the hydration shell of proteins, is also discussed. The concept of protein surfaces with fractal dimensions is elaborated. We finish by exposing an experimental (using small angle X-ray scattering and a computer simulation case study, which are meant as demonstrations of the possibilities we have at hand for investigating the delicate interfaces that connect (and divide protein molecules and the neighboring electrolyte solution.

  10. Comparative study of efficacy, tolerability and compliance of oral iron preparations (iron edetate, iron polymatose complex) and intramuscular iron sorbitol in iron deficiency anaemia in children

    International Nuclear Information System (INIS)

    Afzal, M.; Qureshi, S.M.; Lutafullah, M.

    2009-01-01

    To compare the efficacy, tolerability and compliance of oral iron preparations(iron edetate and Iron polymaltose complex) with each other and with intramuscular iron sorbitol in iron deficiency anaemia in children. A Randomized Controlled Trial (RCT) was carried out at the Paediatric Department of Combined Military Hospital (CMH) from January 2006 to December 2007. In total 146 children, up to 12 years age having haemoglobin (Hb%) less than 8 gm% were included. They were randomly distributed into three groups. Group A(64 cases) received oral sodium iron edetate (SIE), Group B (40 cases) received oral iron polymaltose complex (IPC) and group C (42 cases) received intramuscular iron sorbitol (IS) in recommended dosages. Rise in Hb%>10 gm% was kept as desired target. Maximum duration of treatment planned was 2 weeks for parenteral iron (group C) and 12 weeks for oral iron (groups A and B). Haematological parameters- Hb%, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) were measured at induction followed at 2 weeks, 4 weeks, 8 weeks and 12 weeks after start of treatment. Compliance and drop out rates were determined on each visit. Data was analyzed using SPSS version 10. ANOVA was used to analyze difference in rise in Hb% at various intervals. Statistically significant increase in mean Hb%, MCV, MCHC after 02 weeks was observed in group C (IS). Rise in these parameters became significant in group A (SIE) and B (IPC) after 04 weeks. Persistent rise was observed in oral groups at 08 and 12 weeks. Rise in Hb% was much faster in group C (IS). It took 2 weeks to achieve mean Hb% > 10 gm% and compliance rate was 40.5%, while to achieve same target, duration required was 8 weeks in group A (SIE) and 12 weeks in group B (IPC) and compliance rate was 39% and 30% respectively. Adverse effects were much more common with group A (SIE) as compared to other two groups. Intramuscular iron sorbitol is a reliable and

  11. Self-dual monopoles and toda molecules

    Science.gov (United States)

    Ganoulis, N.; Goddard, P.; Olive, D.

    1982-07-01

    Stable static solutions to a gauge field theory with a Higgs field in the adjoint representation and with vanishing self-coupling are self-dual in the sense of Bogomolny. Leznov and Saveliev showed that a specific form of spherical symmetry reduces these equations to a modified form of the Toda molecule equations associated with the overall gauge symmetry G. Values of the constants of integration are found in terms of the distant Higgs field, guaranteeing regularity of the solution at the origin. The expressions hold for any simple Lie group G, depending on G via its root system.

  12. Single-Molecule Nanomagnets

    Science.gov (United States)

    Friedman, Jonathan R.; Sarachik, Myriam P.

    2010-04-01

    Single-molecule magnets straddle the classical and quantum mechanical worlds, displaying many fascinating phenomena. They may have important technological applications in information storage and quantum computation. We review the physical properties of two prototypical molecular nanomagnets, Mn12-acetate and Fe8: Each behaves as a rigid, spin-10 object and exhibits tunneling between up and down directions. As temperature is lowered, the spin-reversal process evolves from thermal activation to pure quantum tunneling. At low temperatures, magnetic avalanches occur in which the magnetization of an entire sample rapidly reverses. We discuss the important role that symmetry-breaking fields play in driving tunneling and in producing Berry-phase interference. Recent experimental advances indicate that quantum coherence can be maintained on timescales sufficient to allow a meaningful number of quantum computing operations to be performed. Efforts are under way to create monolayers and to address and manipulate individual molecules.

  13. Superexcited states of molecules

    International Nuclear Information System (INIS)

    Nakamura, Hiroki; Takagi, Hidekazu.

    1990-01-01

    The report addresses the nature and major features of molecule's superexcited states, focusing on their involvement in dynamic processes. It also outlines the quantum defect theory which allows various processes involving these states to be treated in a unified way. The Rydberg state has close relation with an ionized state with a positive energy. The quantum defect theory interprets such relation. Specifically, the report first describes the quantum defect theory focusing on its basic principle. The multi-channel quantum defect theory is then outlined centering on how to describe a Rydberg-type superexcited state. Description of a dissociative double-electron excited state is also discussed. The quantum defect theory is based on the fact that the physics of the motion of a Rydberg electron vary with the region in the electron's coordinate space. Finally, various molecular processes that involve a superexcited state are addressed focusing on autoionization, photoionization, dissociative recombination and bonding ionization of diatomic molecules. (N.K.)

  14. Atoms, molecules & elements

    CERN Document Server

    Graybill, George

    2007-01-01

    Young scientists will be thrilled to explore the invisible world of atoms, molecules and elements. Our resource provides ready-to-use information and activities for remedial students using simplified language and vocabulary. Students will label each part of the atom, learn what compounds are, and explore the patterns in the periodic table of elements to find calcium (Ca), chlorine (Cl), and helium (He) through hands-on activities.

  15. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  16. Interstellar molecules and masers

    International Nuclear Information System (INIS)

    Nguyen-Q-Rieu; Guibert, J.

    1978-01-01

    The study of dense and dark clouds, in which hydrogen is mostly in molecular form, became possible since the discovery of interstellar molecules, emitting in the centimeter and millimeter wavelengths. The molecular lines are generally not in local thermal equilibrium (LTE). Their intensity can often be explained by invoking a population inversion mechanism. Maser emission lines due to OH, H 2 O and SiO molecules are among the most intense molecular lines. The H 2 CO molecule, detected in absorption in front of the cold cosmic background radiation of 2.7 K, illustrates the inverse phenomenon, the antimaser absorption. For a radio transition of frequency v, the inversion rate Δn (relative population difference between the upper and lower level) as well as the maser gain can be determined from the radio observations. In the case of the OH lines in the 2 PIsub(3/2), J=3/2 state, the inversion rates approximately 1 to 2% derived from the observations, are comparable with those obtained in the laboratory. The determination of the excitation mechanisms of the masers, through the statistical equilibrium and radiative transfer equations, implies the knowledge of collisional and radiative transition probabilities. A pumping model, which can satisfactorily explain the radio observations of some interstellar OH clouds, will be discussed [fr

  17. Molecule of the Month

    Indian Academy of Sciences (India)

    having solutions coloured red in methanol, violet in etha- nol, blue in isopropyl alcohol, green in acetone and green- ish-yellow in anisole. The electronic ... concentrated sulfuric acid to obtain a symmetric triphenylpyrelium. Box 1. Compounds ...

  18. Stepwise metabolic engineering of Gluconobacter oxydans WSH-003 for the direct production of 2-keto-L-gulonic acid from D-sorbitol.

    Science.gov (United States)

    Gao, Lili; Hu, Yudong; Liu, Jie; Du, Guocheng; Zhou, Jingwen; Chen, Jian

    2014-07-01

    2-Keto-L-gulonic acid (2-KLG), the direct precursor of vitamin C, is currently produced by a two-step fermentation route from D-sorbitol. However, this route involves three bacteria, making the mix-culture system complicated and redundant. Thus, replacement of the conventional two-step fermentation process with a one-step process could be revolutionary in vitamin C industry. In this study, different combinations of five L-sorbose dehydrogenases (SDH) and two L-sorbosone dehydrogenases (SNDH) from Ketogulonicigenium vulgare WSH-001 were introduced into Gluconobacter oxydans WSH-003, an industrial strain used for the conversion of d-sorbitol to L-sorbose. The optimum combination produced 4.9g/L of 2-KLG. In addition, 10 different linker peptides were used for the fusion expression of SDH and SNDH in G. oxydans. The best recombinant strain (G. oxydans/pGUC-k0203-GS-k0095) produced 32.4g/L of 2-KLG after 168h. Furthermore, biosynthesis of pyrroloquinoline quinine (PQQ), a cofactor of those dehydrogenases, was enhanced to improve 2-KLG production. With the stepwise metabolic engineering of G. oxydans, the final 2-KLG production was improved to 39.2g/L, which was 8.0-fold higher than that obtained using independent expression of the dehydrogenases. These results bring us closer to the final one-step industrial-scale production of vitamin C. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  19. INTERPLAY OF SORBITOL PATHWAY OF GLUCOSE METABOLISM, 12/15-LIPOXYGENASE, AND MITOGEN-ACTIVATED PROTEIN KINASES IN THE PATHOGENESIS OF DIABETIC PERIPHERAL NEUROPATHY

    Science.gov (United States)

    Stavniichuk, Roman; Shevalye, Hanna; Hirooka, Hiroko; Nadler, Jerry L.; Obrosova, Irina G.

    2012-01-01

    The interactions among multiple pathogenetic mechanisms of diabetic peripheral neuropathy largely remain unexplored. Increased activity of aldose reductase, the first enzyme of the sorbitol pathway, leads to accumulation of cytosolic Ca++, essentially required for 12/15-lipoxygenase activation. The latter, in turn, causes oxidative-nitrosative stress, an important trigger of MAPK phosphorylation. This study therefore evaluated the interplay of aldose reductase, 12/15-lipoxygenase, and MAPKs in diabetic peripheral neuropathy. In experiment 1, male control and streptozotocin-diabetic mice were maintained with or without the aldose reductase inhibitor fidarestat, 16 mg kg−1 d−1, for 12 weeks. In experiment 2, male control and streptozotocin-diabetic wild-type (C57Bl6/J) and 12/15-lipoxygenase-deficient mice were used. Fidarestat treatment did not affect diabetes-induced increase in glucose concentrations, but normalized sorbitol and fructose concentrations (enzymatic spectrofluorometric assays) as well as 12(S) hydroxyeicosatetraenoic concentration (ELISA), a measure of 12/15-lipoxygenase activity, in the sciatic nerve and spinal cord. 12/15-lipoxygenase expression in these two tissues (Western blot analysis) as well as dorsal root ganglia (immunohistochemistry) was similarly elevated in untreated and fidarestat-treated diabetic mice. 12/15-lipoxygenase gene deficiency prevented diabetesassociated p38 MAPK and ERK, but not SAPK/JNK, activation in the sciatic nerve (Western blot analysis) and all three MAPK activation in the dorsal root ganglia (immunohistochemistry). In contrast, spinal cord p38 MAPK, ERK, and SAPK/JNK were similarly activated in diabetic wild-type and 12/15-lipoxygenase−/− mice. These findings identify the nature and tissue specificity of interactions among three major mechanisms of diabetic peripheral neuropathy, and suggest that combination treatments, rather than monotherapies, can sometimes be an optimal choice for its management. PMID

  20. Efeito de soluções fluoretadas contendo xilitol e sorbitol no número de estreptococos do grupo mutans na saliva de seres humanos

    Directory of Open Access Journals (Sweden)

    Gonçalves Nilza Cristina Lopes Afonso de Valor

    2001-01-01

    Full Text Available O objetivo do estudo foi avaliar o efeito de soluções de fluoreto de sódio a 0,05% contendo 2,5% ou 12,5% de xilitol no número de estreptococos do grupo mutans presentes na saliva. Participaram do estudo duplo cego, do tipo cruzado, 50 meninos entre 8 e 16 anos, distribuídos aleatoriamente em quatro grupos. Destes, 33 finalizaram o estudo. As soluções utilizadas foram: solução placebo; solução de fluoreto de sódio a 0,05%; solução de fluoreto de sódio a 0,05% + 2,5% xilitol + 2% sorbitol; solução de fluoreto de sódio a 0,05% + 12,5% xilitol + 2% sorbitol. Os indivíduos utilizaram 20 mL de uma das soluções, duas vezes ao dia. Cada solução foi utilizada por um período experimental de 28 dias. Os períodos experimentais foram intercalados por períodos de descanso de 10 dias. As soluções contendo xilitol a 2,5% e 12,5% não apresentaram diferença significativa (P = 0,32 em termos do logaritmo do número de estreptococos do grupo mutans. No entanto, a diferença foi significativa quando essas soluções foram comparadas às soluções de fluoreto de sódio e placebo (P < 0,001. Os resultados sugerem que a solução de fluoreto de sódio a 0,05% com adição de xilitol a 2,5% ou 12,5% reduziu significativamente o número de estreptococos do grupo mutans.

  1. Single-Molecule Interfacial Electron Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, H. Peter [Bowling Green State Univ., Bowling Green, OH (United States). Dept. of Chemistry and Center for Photochemical Sciences

    2017-11-28

    This project is focused on the use of single-molecule high spatial and temporal resolved techniques to study molecular dynamics in condensed phase and at interfaces, especially, the complex reaction dynamics associated with electron and energy transfer rate processes. The complexity and inhomogeneity of the interfacial ET dynamics often present a major challenge for a molecular level comprehension of the intrinsically complex systems, which calls for both higher spatial and temporal resolutions at ultimate single-molecule and single-particle sensitivities. Combined single-molecule spectroscopy and electrochemical atomic force microscopy approaches are unique for heterogeneous and complex interfacial electron transfer systems because the static and dynamic inhomogeneities can be identified and characterized by studying one molecule at a specific nanoscale surface site at a time. The goal of our project is to integrate and apply these spectroscopic imaging and topographic scanning techniques to measure the energy flow and electron flow between molecules and substrate surfaces as a function of surface site geometry and molecular structure. We have been primarily focusing on studying interfacial electron transfer under ambient condition and electrolyte solution involving both single crystal and colloidal TiO2 and related substrates. The resulting molecular level understanding of the fundamental interfacial electron transfer processes will be important for developing efficient light harvesting systems and broadly applicable to problems in fundamental chemistry and physics. We have made significant advancement on deciphering the underlying mechanism of the complex and inhomogeneous interfacial electron transfer dynamics in dyesensitized TiO2 nanoparticle systems that strongly involves with and regulated by molecule-surface interactions. We have studied interfacial electron transfer on TiO2 nanoparticle surfaces by using ultrafast single-molecule

  2. Single-Molecule Plasmon Sensing: Current Status and Future Prospects.

    Science.gov (United States)

    Taylor, Adam B; Zijlstra, Peter

    2017-08-25

    Single-molecule detection has long relied on fluorescent labeling with high quantum-yield fluorophores. Plasmon-enhanced detection circumvents the need for labeling by allowing direct optical detection of weakly emitting and completely nonfluorescent species. This review focuses on recent advances in single molecule detection using plasmonic metal nanostructures as a sensing platform, particularly using a single particle-single molecule approach. In the past decade two mechanisms for plasmon-enhanced single-molecule detection have been demonstrated: (1) by plasmonically enhancing the emission of weakly fluorescent biomolecules, or (2) by monitoring shifts of the plasmon resonance induced by single-molecule interactions. We begin with a motivation regarding the importance of single molecule detection, and advantages plasmonic detection offers. We describe both detection mechanisms and discuss challenges and potential solutions. We finalize by highlighting the exciting possibilities in analytical chemistry and medical diagnostics.

  3. Quark chemistry: charmonium molecules

    International Nuclear Information System (INIS)

    De Rujula, A.; Jaffe, R.L.

    1977-01-01

    The theoretical and experimental evidence for two quark-two antiquark hadrons is reviewed. Concentration is placed on predictions for S-wave ''charmonium molecules,'' built of a c anti c charmonium pair and a light quark-antiquark pair. Their spectrum and quantum numbers are predicted and an estimate of their decay couplings and their prediction in monochromatic pion decays from charmonium resonances produced in e + e - -annihilation is given. Some S-wave charmonium resonances should be detectable in these decays, but typical branching ratios are only at the 1% level. 19 references

  4. Ultra-cold molecule production

    International Nuclear Information System (INIS)

    Ramirez-Serrano, Jamie; Chandler, David W.; Strecker, Kevin; Rahn, Larry A.

    2005-01-01

    The production of Ultra-cold molecules is a goal of many laboratories through out the world. Here we are pursuing a unique technique that utilizes the kinematics of atomic and molecular collisions to achieve the goal of producing substantial numbers of sub Kelvin molecules confined in a trap. Here a trap is defined as an apparatus that spatially localizes, in a known location in the laboratory, a sample of molecules whose temperature is below one degree absolute Kelvin. Further, the storage time for the molecules must be sufficient to measure and possibly further cool the molecules. We utilize a technique unique to Sandia to form cold molecules from near mass degenerate collisions between atoms and molecules. This report describes the progress we have made using this novel technique and the further progress towards trapping molecules we have cooled

  5. Comparison between DSC and TMDSC in the investigation into frozen aqueous cryoprotectants solutions.

    Science.gov (United States)

    Santoveña, A; Piñero, M J; Llabrés, M

    2010-12-01

    The influence of thermal parameters in the observation of thermal events and in the calculation of heat transformation in aqueous cryoprotectant solutions after freezing was investigated using conventional differential scanning calorimetry (DSC) and temperature-modulated DSC (TMDSC), respectively. The systems under study were formed by pure water and diluted aqueous solutions of mannitol, trehalose, sucrose, sorbitol, and glycine. The influence of different combinations of frequency and amplitude was analyzed in heating-cooling and heating-iso TMDSC scans. Trehalose, sucrose, and sorbitol present a lesser critical temperature of primary drying than other cryoprotectants studied. The calorimetric variables selection is crucial to detect or not the thermal events, or to detect so with different numerical values. Then, the values of the calorimetric parameters determined are different if measured in a mode of heating-cooling or heating-iso. The TMDSC method-1 used in this study employs a higher number of cycles in each thermal event. The use of Lissajous figures and the study of the C(p in-phase) signal evolution will allow us to understand the complexity of the events detected. The comparative study of both techniques points to the selection of conventional or modulated technique depending on the type of system and the nature of the studied events.

  6. Passing Current through Touching Molecules

    DEFF Research Database (Denmark)

    Schull, G.; Frederiksen, Thomas; Brandbyge, Mads

    2009-01-01

    The charge flow from a single C-60 molecule to another one has been probed. The conformation and electronic states of both molecules on the contacting electrodes have been characterized using a cryogenic scanning tunneling microscope. While the contact conductance of a single molecule between two...

  7. Structure and dynamics of solutions

    CERN Document Server

    Ohtaki, H

    2013-01-01

    Recent advances in the study of structural and dynamic properties of solutions have provided a molecular picture of solute-solvent interactions. Although the study of thermodynamic as well as electronic properties of solutions have played a role in the development of research on the rate and mechanism of chemical reactions, such macroscopic and microscopic properties are insufficient for a deeper understanding of fast chemical and biological reactions. In order to fill the gap between the two extremes, it is necessary to know how molecules are arranged in solution and how they change their pos

  8. Lanthanide single molecule magnets

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Jinkui; Zhang, Peng [Chinese Academy of Sciences, Changchun (China). Changchun Inst. of Applied Chemistry

    2015-10-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures - an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and explore new directions.

  9. Lanthanide single molecule magnets

    CERN Document Server

    Tang, Jinkui

    2015-01-01

    This book begins by providing basic information on single-molecule magnets (SMMs), covering the magnetism of lanthanide, the characterization and relaxation dynamics of SMMs, and advanced means of studying lanthanide SMMs. It then systematically introduces lanthanide SMMs ranging from mononuclear and dinuclear to polynuclear complexes, classifying them and highlighting those SMMs with high barrier and blocking temperatures – an approach that provides some very valuable indicators for the structural features needed to optimize the contribution of an Ising type spin to a molecular magnet. The final chapter presents some of the newest developments in the lanthanide SMM field, such as the design of multifunctional and stimuli-responsive magnetic materials as well as the anchoring and organization of the SMMs on surfaces. In addition, the crystal structure and magnetic data are clearly presented with a wealth of illustrations in each chapter, helping newcomers and experts alike to better grasp ongoing trends and...

  10. Molecules in the Spotlight

    Energy Technology Data Exchange (ETDEWEB)

    Cryan, James

    2010-01-26

    SLAC has just unveiled the world's first X-ray laser, the LCLS. This machine produces pulses of X-rays that are ten billion times brighter than those from conventional sources. One of the goals of this machine is to make movies of chemical reactions, including reactions necessary for life and reactions that might power new energy technologies. This public lecture will show the first results from the LCLS. As a first target, we have chosen nitrogen gas, the main component of the air we breathe. Using the unprecedented power of the LCLS X-rays as a blasting torch, we have created new forms of this molecule and with unique electronic arrangements. Please share with us the first insights from this new technology.

  11. Magnetic field modification of ultracold molecule-molecule collisions

    International Nuclear Information System (INIS)

    Tscherbul, T V; Suleimanov, Yu V; Aquilanti, V; Krems, R V

    2009-01-01

    We present an accurate quantum mechanical study of molecule-molecule collisions in the presence of a magnetic field. The work focuses on the analysis of elastic scattering and spin relaxation in collisions of O 2 ( 3 Σ g - ) molecules at cold (∼0.1 K) and ultracold (∼10 -6 K) temperatures. Our calculations show that magnetic spin relaxation in molecule-molecule collisions is extremely efficient except at magnetic fields below 1 mT. The rate constant for spin relaxation at T=0.1 K and a magnetic field of 0.1 T is found to be as large as 6.1x10 -11 cm -3 s -1 . The magnetic field dependence of elastic and inelastic scattering cross sections at ultracold temperatures is dominated by a manifold of Feshbach resonances with the density of ∼100 resonances per Tesla for collisions of molecules in the absolute ground state. This suggests that the scattering length of ultracold molecules in the absolute ground state can be effectively tuned in a very wide range of magnetic fields. Our calculations demonstrate that the number and properties of the magnetic Feshbach resonances are dramatically different for molecules in the absolute ground and excited spin states. The density of Feshbach resonances for molecule-molecule scattering in the low-field-seeking Zeeman state is reduced by a factor of 10.

  12. Influence of polymers on lysozyme molecules association

    Directory of Open Access Journals (Sweden)

    Gromovoy T. Yu

    2011-12-01

    Full Text Available Aim. Study of lysozyme molecules behaviour at immobilization in gelatin and carboxymethyl cellulose sodium salt solutions by matrix-assisted laser desorption/ionization (MALDI. Methods. Determination of the activity of lysozyme, both free and entrapped in gelatin and carboxymethyl cellulose sodium salt (Na-CMC solutions, was conducted by bacteriolytic method. The enzyme interaction with polymers was confirmed by viscometry and mass-spectrometry methods. Results. The occurrence of lysozyme associates in aqueous solution in monomeric and oligomeric forms was shown. A non-valent interaction of the enzyme with solutions of polymers results in the dissociation of oligomeric associates into subunits, which depends on the support nature and mass ratio of lysozyme to polymer. The quantitative retention of immobilized lysozyme hydrolytic activity was established, which favours obtaining mucoadhesive film forms with bacteriolytic action. Conclusions. The lysozyme immobilization by non-valent interactions in gelatin solution and Na-CMC solutions causes dissociation of the enzyme oligomeric structures; a stronger lysozyme coupling with NaCMC was noted.

  13. Plugging solution

    Energy Technology Data Exchange (ETDEWEB)

    Sharipov, A U; Yangirov, I Z

    1982-01-01

    A clay-powder, cement, and water-base plugging solution is proposed having reduced solution viscosity characteristics while maintaining tensile strength in cement stone. This solution utilizes silver graphite and its ingredients, by mass weight, are as follows: cement 51.2-54.3%; claypowder 6.06-9.1%; silver graphite 0.24-0.33%; with water making up the remainder.

  14. Evaluación de los efectos en las propiedades fisicoquímicas, sensoriales y texturales de polidextrosa, fructosa y sorbitol como sustitutos de azúcar en la elaboración de arequipe

    OpenAIRE

    Valencia García, Francia Elena; Millán Cardona, Leonidas de Jesús; Ramírez Herrera, Nathalia

    2008-01-01

    Introduction. The concern on the excessive consumption of sugar in the diet has provoked a modification of traditional products to reduce their sucrose content and, at the same time, keep their sensorial and physical-chemical characteristics similar to those of other products made with normal sucrose content. Objective. To evaluate the effects of sugar substitutes such as polydextrose, fructose and sorbitol in the physical, chemical, sensorial and textural propertie...

  15. Structure formation in bis(terpyridine) derivative adlayers: molecule-substrate versus molecule-molecule interactions.

    Science.gov (United States)

    Hoster, Harry E; Roos, Matthias; Breitruck, Achim; Meier, Christoph; Tonigold, Katrin; Waldmann, Thomas; Ziener, Ulrich; Landfester, Katharina; Behm, R Jürgen

    2007-11-06

    The influence of the substrate and the deposition conditions-vapor deposition versus deposition from solution-on the structures formed upon self-assembly of deposited bis(terpyridine) derivative (2,4'-BTP) monolayers on different hexagonal substrates, including highly oriented pyrolytic graphite (HOPG), Au(111), and (111)-oriented Ag thin films, was investigated by high-resolution scanning tunneling microscopy and by model calculations of the intermolecular energies and the lateral corrugation of the substrate-adsorbate interaction. Similar quasi-quadratic network structures with almost the same lattice constants obtained on all substrates are essentially identical to the optimum configuration expected from an optimization of the adlayer structure with C-H...N-type bridging bonds as a structure-determining factor, which underlines a key role of the intermolecular interactions in adlayer order. Slight distortions from the optimum values to form commensurate adlayer structures on the metal substrates and the preferential orientation of the adlayer with respect to the substrate are attributed to the substrate-adsorbate interactions, specifically, the lateral corrugation in the substrate-adsorbate interaction upon lateral displacement and rotation of the adsorbed BTP molecules. The fact that similar adlayer structures are obtained on HOPG under ultrahigh vacuum conditions (solid|gas interface) and on HOPG in trichlorobenzene (solid|liquid interface) indicates that the intermolecular interactions are not severely affected by the solvent.

  16. Molecular studies on di-sodium tartrate molecule

    Science.gov (United States)

    Divya, P.; Jayakumar, S.; George, Preethamary; Shubashree, N. S.; Ahmed. M, Anees

    2015-06-01

    Structural characterization is important for the development of new material. The acoustical parameters such as Free Length, Internal Pressure have been measured from ultrasonic velocity, density for di sodium tartrate an optically active molecule at different temperatures using ultrasonic interferometer of frequency (2MHZ). The ultrasonic velocity increases with increase in concentration there is an increase in solute-solvent interaction. The stability constant had been calculated. SEM with EDAX studies has been done for Di-sodium tartrate an optically active molecule.

  17. Sorbitol-Fermenting Enterohemorrhagic Escherichia coli O157:H- Isolates from Czech Patients with Novel Plasmid Composition Not Previously Seen in German Isolates.

    Science.gov (United States)

    Bauwens, Andreas; Marejková, Monika; Middendorf-Bauchart, Barbara; Prager, Rita; Kossow, Annelene; Zhang, Wenlan; Karch, Helge; Mellmann, Alexander; Bielaszewska, Martina

    2017-12-01

    Sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:H - strains, first identified in Germany, have emerged as important pathogens throughout Europe. Besides chromosomally encoded Shiga toxin 2a (the major virulence factor), several putative virulence loci, including the hly , etp , and sfp operons, encoding EHEC hemolysin, type II secretion system proteins, and Sfp fimbriae, respectively, are located on the 121-kb plasmid pSFO157 in German strains. Here we report novel SF EHEC O157:H - strains isolated from patients in the Czech Republic. These strains share the core genomes and chromosomal virulence loci encoding toxins ( stx 2a and the cdtV -ABC operon) and adhesins ( eae -γ, efa1 , lpfA O157OI-141 , and lpfA O157OI-154 ) with German strains but differ essentially in their plasmids. In contrast to all previously detected SF EHEC O157:H - strains, the Czech strains carry two plasmids, of 79 kb and 86 kb. The 79-kb plasmid harbors the sfp operon, but neither of the plasmids contains the hly and etp operons. Sequence analyses demonstrated that the 79-kb plasmid (pSFO157 258/98-1) evolved from pSFO157 of German strains by deletion of a 41,534-bp region via homologous recombination, resulting in loss of the hly and etp operons. The 86-kb plasmid (pSFO157 258/98-2) displays 98% sequence similarity to a 92.7-kb plasmid of an extraintestinal pathogenic E. coli bloodstream isolate. Our finding of this novel plasmid composition in SF EHEC O157:H - strains extends the evolutionary history of EHEC O157 plasmids. Moreover, the unique molecular plasmid characteristics permit the identification of such strains, thereby facilitating further investigations of their geographic distribution, clinical significance, and epidemiology. IMPORTANCE Since their first identification in Germany in 1989, sorbitol-fermenting enterohemorrhagic Escherichia coli O157:H - (nonmotile) strains have emerged as important causes of the life-threatening disease hemolytic

  18. Sorbitol-Fermenting Enterohemorrhagic Escherichia coli O157:H− Isolates from Czech Patients with Novel Plasmid Composition Not Previously Seen in German Isolates

    Science.gov (United States)

    Bauwens, Andreas; Marejková, Monika; Middendorf-Bauchart, Barbara; Prager, Rita; Kossow, Annelene; Zhang, Wenlan; Karch, Helge

    2017-01-01

    ABSTRACT Sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:H− strains, first identified in Germany, have emerged as important pathogens throughout Europe. Besides chromosomally encoded Shiga toxin 2a (the major virulence factor), several putative virulence loci, including the hly, etp, and sfp operons, encoding EHEC hemolysin, type II secretion system proteins, and Sfp fimbriae, respectively, are located on the 121-kb plasmid pSFO157 in German strains. Here we report novel SF EHEC O157:H− strains isolated from patients in the Czech Republic. These strains share the core genomes and chromosomal virulence loci encoding toxins (stx2a and the cdtV-ABC operon) and adhesins (eae-γ, efa1, lpfAO157OI-141, and lpfAO157OI-154) with German strains but differ essentially in their plasmids. In contrast to all previously detected SF EHEC O157:H− strains, the Czech strains carry two plasmids, of 79 kb and 86 kb. The 79-kb plasmid harbors the sfp operon, but neither of the plasmids contains the hly and etp operons. Sequence analyses demonstrated that the 79-kb plasmid (pSFO157 258/98-1) evolved from pSFO157 of German strains by deletion of a 41,534-bp region via homologous recombination, resulting in loss of the hly and etp operons. The 86-kb plasmid (pSFO157 258/98-2) displays 98% sequence similarity to a 92.7-kb plasmid of an extraintestinal pathogenic E. coli bloodstream isolate. Our finding of this novel plasmid composition in SF EHEC O157:H− strains extends the evolutionary history of EHEC O157 plasmids. Moreover, the unique molecular plasmid characteristics permit the identification of such strains, thereby facilitating further investigations of their geographic distribution, clinical significance, and epidemiology. IMPORTANCE Since their first identification in Germany in 1989, sorbitol-fermenting enterohemorrhagic Escherichia coli O157:H− (nonmotile) strains have emerged as important causes of the life-threatening disease hemolytic

  19. Detecting and identifying small molecules in a nanopore flux capacitor

    International Nuclear Information System (INIS)

    Bearden, Samuel; Zhang, Guigen; McClure, Ethan

    2016-01-01

    A new method of molecular detection in a metallic-semiconductor nanopore was developed and evaluated with experimental and computational methods. Measurements were made of the charging potential of the electrical double layer (EDL) capacitance as charge-carrying small molecules translocated the nanopore. Signals in the charging potential were found to be correlated to the physical properties of analyte molecules. From the measured signals, we were able to distinguish molecules with different valence charge or similar valence charge but different size. The relative magnitude of the signals from different analytes was consistent over a wide range of experimental conditions, suggesting that the detected signals are likely due to single molecules. Computational modeling of the nanopore system indicated that the double layer potential signal may be described in terms of disruption of the EDL structure due to the size and charge of the analyte molecule, in agreement with Huckel and Debye’s analysis of the electrical atmosphere of electrolyte solutions. (paper)

  20. Single-Molecule Electronics: Chemical and Analytical Perspectives.

    Science.gov (United States)

    Nichols, Richard J; Higgins, Simon J

    2015-01-01

    It is now possible to measure the electrical properties of single molecules using a variety of techniques including scanning probe microcopies and mechanically controlled break junctions. Such measurements can be made across a wide range of environments including ambient conditions, organic liquids, ionic liquids, aqueous solutions, electrolytes, and ultra high vacuum. This has given new insights into charge transport across molecule electrical junctions, and these experimental methods have been complemented with increasingly sophisticated theory. This article reviews progress in single-molecule electronics from a chemical perspective and discusses topics such as the molecule-surface coupling in electrical junctions, chemical control, and supramolecular interactions in junctions and gating charge transport. The article concludes with an outlook regarding chemical analysis based on single-molecule conductance.

  1. Friction mediated by redox-active supramolecular connector molecules.

    Science.gov (United States)

    Bozna, B L; Blass, J; Albrecht, M; Hausen, F; Wenz, G; Bennewitz, R

    2015-10-06

    We report on a friction study at the nanometer scale using atomic force microscopy under electrochemical control. Friction arises from the interaction between two surfaces functionalized with cyclodextrin molecules. The interaction is mediated by connector molecules with (ferrocenylmethyl)ammonium end groups forming supramolecular complexes with the cyclodextrin molecules. With ferrocene connector molecules in solution, the friction increases by a factor of up to 12 compared to control experiments without connector molecules. The electrochemical oxidation of ferrocene to ferrocenium causes a decrease in friction owing to the lower stability of ferrocenium-cyclodextrin complex. Upon switching between oxidative and reduction potentials, a change in friction by a factor of 1.2-1.8 is observed. Isothermal titration calorimetry reveals fast dissociation and rebinding kinetics and thus an equilibrium regime for the friction experiments.

  2. Electron-excited molecule interactions

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Tennessee Univ., Knoxville, TN

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

  3. Electrode redox reactions with polarizable molecules

    Science.gov (United States)

    Matyushov, Dmitry V.

    2018-04-01

    A theory of redox reactions involving electron transfer between a metal electrode and a polarizable molecule in solution is formulated. Both the existence of molecular polarizability and its ability to change due to electron transfer distinguish this problem from classical theories of interfacial electrochemistry. When the polarizability is different between the oxidized and reduced states, the statistics of thermal fluctuations driving the reactant over the activation barrier becomes non-Gaussian. The problem of electron transfer is formulated as crossing of two non-parabolic free energy surfaces. An analytical solution for these free energy surfaces is provided and the activation barrier of electrode electron transfer is given in terms of two reorganization energies corresponding to the oxidized and reduced states of the molecule in solution. The new non-Gaussian theory is, therefore, based on two theory parameters in contrast to one-parameter Marcus formulation for electrode reactions. The theory, which is consistent with the Nernst equation, predicts asymmetry between the cathodic and anodic branches of the electrode current. They show different slopes at small electrode overpotentials and become curved at larger overpotentials. However, the curvature of the Tafel plot is reduced compared to the Marcus-Hush model and approaches the empirical Butler-Volmer form with different transfer coefficients for the anodic and cathodic currents.

  4. Organic Molecules in Meteorites

    Science.gov (United States)

    Martins, Zita

    2015-08-01

    Carbonaceous meteorites are primitive samples from the asteroid belt, containing 3-5wt% organic carbon. The exogenous delivery of organic matter by carbonaceous meteorites may have contributed to the organic inventory of the early Earth. The majority (>70%) of the meteoritic organic material consist of insoluble organic matter (IOM) [1]. The remaining meteoritic organic material (meteorites contain soluble organic molecules with different abundances and distributions, which may reflect the extension of aqueous alteration or thermal metamorphism on the meteorite parent bodies. Extensive aqueous alteration on the meteorite parent body may result on 1) the decomposition of α-amino acids [5, 6]; 2) synthesis of β- and γ-amino acids [2, 6-9]; 3) higher relative abundances of alkylated polycyclic aromatic hydrocarbons (PAHs) [6, 10]; and 4) higher L-enantiomer excess (Lee) value of isovaline [6, 11, 12].The soluble organic content of carbonaceous meteorites may also have a contribution from Fischer-Tropsch/Haber-Bosch type gas-grain reactions after the meteorite parent body cooled to lower temperatures [13, 14].The analysis of the abundances and distribution of the organic molecules present in meteorites helps to determine the physical and chemical conditions of the early solar system, and the prebiotic organic compounds available on the early Earth.[1] Cody and Alexander (2005) GCA 69, 1085. [2] Cronin and Chang (1993) in: The Chemistry of Life’s Origin. pp. 209-258. [3] Martins and Sephton (2009) in: Amino acids, peptides and proteins in organic chemistry. pp. 1-42. [4] Martins (2011) Elements 7, 35. [5] Botta et al. (2007) MAPS 42, 81. [6] Martins et al. (2015) MAPS, in press. [7] Cooper and Cronin (1995) GCA 59, 1003. [8] Glavin et al. (2006) MAPS. 41, 889. [9] Glavin et al. (2011) MAPS 45, 1948. [10] Elsila et al. (2005) GCA 5, 1349. [11] Glavin and Dworkin (2009) PNAS 106, 5487. [12] Pizzarello et al. (2003) GCA 67, 1589. [13] Chan et al. (2012) MAPS. 47, 1502

  5. Electrochemical proton relay at the single-molecule level

    DEFF Research Database (Denmark)

    Kuznetsov, A. M.; Medvedev, I. G.; Ulstrup, Jens

    2009-01-01

    A scheme for the experimental study of single-proton transfer events, based on proton-coupled two-electron transfer between a proton donor and a proton acceptor molecule confined in the tunneling gap between two metal leads in electrolyte solution is suggested. Expressions for the electric current...... are derived and compared with formalism for electron tunneling through redox molecules. The scheme allows studying the kinetics of proton and hydrogen atom transfer as well as kinetic isotope effects at the single-molecule level under electrochemical potential control....

  6. Tunnelling of a molecule

    International Nuclear Information System (INIS)

    Jarvis, P.D.; Bulte, D.P.

    1998-01-01

    A quantum-mechanical description of tunnelling is presented for a one-dimensional system with internal oscillator degrees of freedom. The 'charged diatomic molecule' is frustrated on encountering a barrier potential by its centre of charge not being coincident with its centre of mass, resulting in transitions amongst internal states. In an adiabatic limit, the tunnelling of semiclassical coherent-like oscillator states is shown to exhibit the Hartman and Bueuttiker-Landauer times t H and t BL , with the time dependence of the coherent state parameter for the tunnelled state given by α(t) = α e -iω(t+Δt) , Δt = t H - it BL . A perturbation formalism is developed, whereby the exact transfer matrix can be expanded to any desired accuracy in a suitable limit. An 'intrinsic' time, based on the oscillator transition rate during tunnelling, transmission or reflection, is introduced. In simple situations the resulting intrinsic tunnelling time is shown to vanish to lowest order. In the general case a particular (nonzero) parametrisation is inferred, and its properties discussed in comparison with the literature on tunnelling times for both wavepackets and internal clocks. Copyright (1998) CSIRO Australia

  7. Single molecule tracking

    Science.gov (United States)

    Shera, E. Brooks

    1988-01-01

    A detection system is provided for identifying individual particles or molecules having characteristic emission in a flow train of the particles in a flow cell. A position sensitive sensor is located adjacent the flow cell in a position effective to detect the emissions from the particles within the flow cell and to assign spatial and temporal coordinates for the detected emissions. A computer is then enabled to predict spatial and temporal coordinates for the particle in the flow train as a function of a first detected emission. Comparison hardware or software then compares subsequent detected spatial and temporal coordinates with the predicted spatial and temporal coordinates to determine whether subsequently detected emissions originate from a particle in the train of particles. In one embodiment, the particles include fluorescent dyes which are excited to fluoresce a spectrum characteristic of the particular particle. Photones are emitted adjacent at least one microchannel plate sensor to enable spatial and temporal coordinates to be assigned. The effect of comparing detected coordinates with predicted coordinates is to define a moving sample volume which effectively precludes the effects of background emissions.

  8. Structure and hydrodynamic properties of plectin molecules.

    Science.gov (United States)

    Foisner, R; Wiche, G

    1987-12-05

    Plectin is a cytoskeletal, high molecular weight protein of widespread and abundant occurrence in cultured cells and tissues. To study its molecular structure, the protein was purified from rat glioma C6 cells and subjected to chemical and biophysical analyses. Plectin's polypeptide chains have an apparent molecular weight of 300,000, as shown by one-dimensional sodium dodecyl sulfate/polyacrylamide electrophoresis. Cross-linking of non-denatured plectin in solution with dimethyl suberimidate and electrophoretic analyses on sodium dodecyl sulfate/agarose gels revealed that the predominant soluble plectin species was a molecule of 1200 X 10(3) Mr consisting of four 300 X 10(3) Mr polypeptide chains. Hydrodynamic properties of plectin in solution were obtained by sedimentation velocity centrifugation and high-pressure liquid chromatography analysis yielding a sedimentation coefficient of 10 S and a Stokes radius of 27 nm. The high f/fmin ratio of 4.0 indicated a very elongated shape of plectin molecules and an axial ratio of about 50. Shadowing and negative staining electron microscopy of plectin molecules revealed multiple domains: a rigid rod of 184 nm in length and 2 nm in diameter, and two globular heads of 9 nm diameter at each end of the rod. Circular dichroism spectra suggested a composition of 30% alpha-helix, 9% beta-structure and 61% random coil or aperiodic structure. The rod-like shape, the alpha-helix content as well as the thermal transition within a midpoint of 45 degrees C and the transition enthalpy (168 kJ/mol) of secondary structure suggested a double-stranded, alpha-helical coiled coil rod domain. Based on the available data, we favor a model of native plectin as a dumb-bell-like association of four 300 X 10(3) Mr polypeptide chains. Electron microscopy and turbidity measurements showed that plectin molecules self-associate into various oligomeric states in solutions of nearly physiological ionic strength. These interactions apparently involved

  9. Spectral simulations of polar diatomic molecules immersed in He clusters: application to the ICl (X) molecule

    International Nuclear Information System (INIS)

    Villarreal, P; Lara-Castells, M P de; Prosmiti, R; Delgado-Barrio, G; Lopez-Duran, D; Gianturco, F A; Jellinek, J

    2007-01-01

    A recently developed quantum-chemistry-like methodology to study molecules solvated in atomic clusters is applied to the ICl (iodine chloride) polar diatomic molecule immersed in clusters of He atoms. The atoms of the solvent clusters are treated as the 'electrons' and the solvated molecule as a structured 'nucleus' of the combined solvent-solute system. The helium-helium and helium-dopant interactions are represented by parametrized two-body and ab initio three-body potentials, respectively. The ground-state wavefunctions are used to compute the infrared (IR) spectra of the solvated molecule. In agreement with the experimental observations, the computed spectra exhibit considerable differences depending on whether the solvent cluster is comprised of bosonic ( 4 He) or fermionic ( 3 He) atoms. The source of these differences is attributed to the different spin-statistics of the solvent clusters. The bosonic versus fermionic nature of the solvent is reflected in the IR absorption selection rules. Only P and R branches with single state transitions appear in the spectrum when the molecule is solvated in a bosonic cluster. On the other hand, when the solvent represents a fermionic environment, quasi-degenerate multiplets of spin states contribute to each branch and, in addition, the Q-branch becomes also allowed. Combined, these two factors explain the more congested nature of the spectrum in the fermionic case

  10. Theoretical Investigations Regarding Single Molecules

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind

    Neoclassical Valence Bond Theory, Quantum Transport, Quantum Interference, Kondo Effect, and Electron Pumping. Trap a single organic molecule between two electrodes and apply a bias voltage across this "molecular junction". When electrons pass through the molecule, the different electron paths can...... interfere destructively or constructively. Destructive interference effects in electron transport could potentially improve thermo-electrics, organic logic circuits and energy harvesting. We have investigated destructive interference in off-resonant transport through organic molecules, and have found a set...

  11. Nanospiral Formation by Droplet Drying: One Molecule at a Time

    Directory of Open Access Journals (Sweden)

    Wan Lei

    2011-01-01

    Full Text Available Abstract We have created nanospirals by self-assembly during droplet evaporation. The nanospirals, 60–70 nm in diameter, formed when solvent mixtures of methanol and m-cresol were used. In contrast, spin coating using only methanol as the solvent produced epitaxial films of stripe nanopatterns and using only m-cresol disordered structure. Due to the disparity in vapor pressure between the two solvents, droplets of m-cresol solution remaining on the substrate serve as templates for the self-assembly of carboxylic acid molecules, which in turn allows the visualization of solution droplet evaporation one molecule at a time.

  12. Biofuels: from microbes to molecules

    National Research Council Canada - National Science Library

    Lu, Xuefeng

    2014-01-01

    .... The production of different biofuel molecules including hydrogen, methane, ethanol, butanol, higher chain alcohols, isoprenoids and fatty acid derivatives, from genetically engineered microbes...

  13. Pitfall in quantum mechanical/molecular mechanical molecular dynamics simulation of small solutes in solution.

    Science.gov (United States)

    Hu, Hao; Liu, Haiyan

    2013-05-30

    Developments in computing hardware and algorithms have made direct molecular dynamics simulation with the combined quantum mechanical/molecular mechanical methods affordable for small solute molecules in solution, in which much improved accuracy can be obtained via the quantum mechanical treatment of the solute molecule and even sometimes water molecules in the first solvation shell. However, unlike the conventional molecular mechanical simulations of large molecules, e.g., proteins, in solutions, special care must be taken in the technical details of the simulation, including the thermostat of the solute/solvent system, so that the conformational space of the solute molecules can be properly sampled. We show here that the common setup for classical molecular mechanical molecular dynamics simulations, such as the Berendsen or single Nose-Hoover thermostat, and/or rigid water models could lead to pathological sampling of the solutes' conformation. In the extreme example of a methanol molecule in aqueous solution, improper and sluggish setups could generate two peaks in the distribution of the O-H bond length. We discuss the factors responsible for this somewhat unexpected result and evoke a simple and ancient technical fix-up to resolve this problem.

  14. Growing interstellar molecules with ion-molecule reactions

    International Nuclear Information System (INIS)

    Bohme, D.K.

    1989-01-01

    Laboratory measurements of gas-phase ion-molecule reactions continue to provide important insights into the chemistry of molecular growth in interstellar environments. It is also true that the measurements are becoming more demanding as larger molecules capture our interest. While some of these measurements are motivated by current developments in chemical models of interstellar environments or by new molecular observations by astronomers, others explore novel chemistry which can lead to predictions of new interstellar molecules. Here the author views the results of some recent measurements, taken in the Ion Chemistry Laboratory at York University with the SIFT technique, which address some of the current needs of modellers and observers and which also provide some new fundamental insight into molecular growth, particularly when it occurs in the presence of large molecules such as PAH molecules which are now thought to have a major influence on the chemistry of interstellar environments in which they are present

  15. Effect of three-year consumption of erythritol, xylitol and sorbitol candies on various plaque and salivary caries-related variables.

    Science.gov (United States)

    Runnel, Riina; Mäkinen, Kauko K; Honkala, Sisko; Olak, Jana; Mäkinen, Pirkko-Liisa; Nõmmela, Rita; Vahlberg, Tero; Honkala, Eino; Saag, Mare

    2013-12-01

    The objective of the present paper is to report results from oral biologic studies carried out in connection with a caries study. Samples of whole-mouth saliva and dental plaque were collected from initially 7- to 8-year-old subjects who participated in a 3-year school-based programme investigating the effect of the consumption of polyol-containing candies on caries rates. The subjects were randomized in three cohorts, consumed erythritol, xylitol, or sorbitol candies. The daily polyol consumption from the candies was approximately 7.5 g. A significant reduction in dental plaque weight from baseline (psorbitol groups. Usage of polyol candies had no significant or consistent effect on the levels of plaque protein, glucose, glycerol, or calcium, determined yearly in connection with caries examinations. After three years, the plaque of erythritol-receiving subjects contained significantly (psorbitol. Lactic acid levels partly followed the same pattern. The consumption of erythritol was generally associated with significantly (psorbitol candies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Self-assembled structures of 1,3:2,4-di(3,4-dimethylbenzylidene) sorbitol in hydrophobic polymer matrices prepared using different heat treatments

    Science.gov (United States)

    Lai, Wei-Chi; Tseng, Shen-Jhen; Huang, Po-Hsun

    2015-11-01

    We report a method for tuning the nanoarchitectures of 1,3:2,4-di(3,4-dimethylbenzylidene) sorbitol (DMDBS) with poly(vinylidene fluoride) (PVDF) polymer matrices. Hydrophobic PVDF facilitated the formation of nanofibrils during heating. The self-assembly behaviors of DMDBS were further tuned by altering the different heat treatments. When the samples were prepared with a rapid heating rate (shorter annealing time), smaller amounts of melted PVDF were excluded due to the shorter time for aggregation of DMDBS, leading to larger complex structures of DMDBS and PVDF. Therefore, longer and thicker nanofibrils (around 100 nm) were observed using scanning electron microscopy. As the samples were prepared with a slow heating rate (longer annealing time), DMDBS had more time to aggregate, and therefore, larger amounts of melted PVDF were excluded. Smaller complex structures of DMDBS and PVDF caused the formation of shorter and thinner nanofibrils (around 40 nm). In addition, small-angle X-ray scattering results indicated that the longer and thicker nanofibrils were mostly excluded outside the PVDF crystalline bundles after cooling because they were too large to be easily incorporated between the PVDF crystalline lamellae. However, a large portion of the smaller and thinner nanofibrils was trapped between the crystalline lamellae after cooling due to their smaller sizes. As expected, the PVDF spherulitic morphologies were affected, but the PVDF crystalline microstructures were not significantly altered by the addition of DMDBS, as shown by the results from polarized optical microscopy and Fourier transform infrared spectroscopy.

  17. Sorbitol-fermenting Bifidobacteria are indicators of very recent human faecal pollution in streams and groundwater habitats in urban tropical lowlands

    Science.gov (United States)

    2010-01-01

    Sorbitol-fermenting Bifidobacteria (SFB) proved to be an excellent indicator of very recent human faecal pollution (hours to days) in the investigated tropical stream and groundwater habitats. SFB were recovered from human faeces and sources potentially contaminated with human excreta. SFB were undetectable in animal faeces and environmental samples not contaminated with human faeces. Microcosm studies demonstrated a rapid die-off rate in groundwater (T90 value 0.6 days) and stream water (T90 value 0.9–1.7 days). Discrimination sensitivity analysis, including E. coli, faecal coliforms, total coliforms and Clostridium perfringens spores, revealed high ability of SFB to distinguish differing levels of faecal pollution especially for streams although high background levels of interfering bacteria can complicate its recovery on the used medium. Due to its faster die-off, as compared to many waterborne pathogens, SFB cannot replace microbiological standard parameters for routine water quality monitoring but it is highly recommendable as a specific and complementary tool when human faecal pollution has to be localized or verified. Because of its exclusive faecal origin and human specificity it seems also worthwhile to include SFB in future risk evaluation studies at tropical water resources in order to evaluate under which situations risks of infection may be indicated. PMID:20375476

  18. S-Mercuration of rat sorbitol dehydrogenase by methylmercury causes its aggregation and the release of the zinc ion from the active site.

    Science.gov (United States)

    Kanda, Hironori; Toyama, Takashi; Shinohara-Kanda, Azusa; Iwamatsu, Akihiro; Shinkai, Yasuhiro; Kaji, Toshiyuki; Kikushima, Makoto; Kumagai, Yoshito

    2012-11-01

    We previously developed a screening method to identify proteins that undergo aggregation through S-mercuration by methylmercury (MeHg) and found that rat arginase I is a target protein for MeHg (Kanda et al. in Arch Toxicol 82:803-808, 2008). In the present study, we characterized another S-mercurated protein from a rat hepatic preparation that has a subunit mass of 42 kDa, thereby facilitating its aggregation. Two-dimensional SDS-polyacrylamide gel electrophoresis and subsequent peptide mass fingerprinting using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry revealed that the 42 kDa protein was NAD-dependent sorbitol dehydrogenase (SDH). With recombinant rat SDH, we found that MeHg is covalently bound to SDH through Cys44, Cys119, Cys129 and Cys164, resulting in the inhibition of its catalytic activity, release of zinc ions and facilitates protein aggregation. Mutation analysis indicated that Cys44, which ligates the active site zinc atom, and Cys129 play a crucial role in the MeHg-mediated aggregation of SDH. Pretreatment with the cofactor NAD, but not NADP or FAD, markedly prevented aggregation of SDH. Such a protective effect of NAD on the aggregation of SDH caused by MeHg is discussed.

  19. Zero-mode waveguide nanophotonic structures for single molecule characterization

    Science.gov (United States)

    Crouch, Garrison M.; Han, Donghoon; Bohn, Paul W.

    2018-05-01

    Single-molecule characterization has become a crucial research tool in the chemical and life sciences, but limitations, such as limited concentration range, inability to control molecular distributions in space, and intrinsic phenomena, such as photobleaching, present significant challenges. Recent developments in non-classical optics and nanophotonics offer promising routes to mitigating these restrictions, such that even low affinity (K D ~ mM) biomolecular interactions can be studied. Here we introduce and review specific nanophotonic devices used to support single molecule studies. Optical nanostructures, such as zero-mode waveguides (ZMWs), are usually fabricated in thin gold or aluminum films and serve to confine the observation volume of optical microspectroscopy to attoliter to zeptoliter volumes. These simple nanostructures allow individual molecules to be isolated for optical and electrochemical analysis, even when the molecules of interest are present at high concentration (µM–mM) in bulk solution. Arrays of ZMWs may be combined with optical probes such as single molecule fluorescence, single molecule fluorescence resonance energy transfer, and fluorescence correlation spectroscopy for distributed analysis of large numbers of single-molecule reactions or binding events in parallel. Furthermore, ZMWs may be used as multifunctional devices, for example by combining optical and electrochemical functions in a single discrete architecture to achieve electrochemical ZMWs. In this review, we will describe the optical properties, fabrication, and applications of ZMWs for single-molecule studies, as well as the integration of ZMWs into systems for chemical and biochemical analysis.

  20. Magnetic properties of 1 : 4 complexes of CoCl2 and pyridines carrying carbenes (S(0) = 4/2, 6/2, and 8/2) in diluted frozen solution; influence of carbene multiplicity on heterospin single-molecule magnets.

    Science.gov (United States)

    Karasawa, Satoru; Nakano, Kimihiro; Tanokashira, Jun-ichi; Yamamoto, Noriko; Yoshizaki, Takahito; Koga, Noboru

    2012-11-28

    The microcrystalline sample of a parent complex, [CoCl(2)(py)(4)], showed a single-molecule magnet (SMM) behavior with an effective activation barrier, U(eff)/k(B), of 16 K for reversal of the magnetism in the presence of a dc field of 3 kOe. Pyridine ligands having 2-4 diazo moieties, DYpy; Y = 2, 3l, 3b, and 4, were prepared and confirmed to be quintet, septet, septet, and nonet in the ground state, respectively, after irradiation. The 1 : 4 complexes, CoCl(2)(DYpy)(4); Y = 2, 3l, 3b, and 4 in frozen solutions after irradiation showed the magnetic behaviors of SMMs with total spin multiplicity, S(total) = 17/2, 25/2, 25/2, and 33/2, respectively. Hysteresis loops depending on the temperature were observed and the values of coercive force, H(c), at 1.9 K were 12, 8.4, 11, and 8.1 kOe for CoCl(2)(CYpy)(4); Y = 2, 3l, 3b, and 4, respectively. In dynamic magnetic susceptibility experiments, ac magnetic susceptibility data obeyed the Arrhenius law to give U(eff)/k(B) values of 94, 92, 93, and 87 K for CoCl(2)(CYpy)(4); Y = 2, 3l, 3b, and 4, respectively, while the relaxation times for CoCl(2)(CYpy)(4); Y = 2 and 3l, obtained by dc magnetization decay in the range of 3.5-1.9 K slightly deviated downward from Arrhenius plots on cooling. The dynamic magnetic behaviors for CoCl(2)(CYpy)(4) including [CoCl(2)(py)(4)] and CoCl(2)(C1py)(4) suggested that the generated carbenes interacted with the cobalt ion to increase the relaxation time, τ(q), due to the spin quantum tunneling magnetization, which became larger with increasing S(total) of the complex.

  1. Application of a small molecule radiopharmaceutical concept to improve kinetics

    International Nuclear Information System (INIS)

    Jeong, Jae Min

    2016-01-01

    Recently, large molecules or nanoparticles are actively studied as radiopharmaceuticals. However, their kinetics is problematic because of a slow penetration through the capillaries and slow distribution to the target. To improve the kinetics, a two-step targeting method can be applied by using small molecules and very rapid copper-free click reaction. Although this method might have limitations such as internalization of the first targeted conjugate, it will provide high target-to-non-target ratio imaging of radiopharmaceuticals. The majority of radiopharmaceuticals belong to small molecules of which the molecular weight is less than 2000 Da, and the molecular size is smaller than 2 nm generally. The outstanding feature of the small molecule radiopharmaceuticals compared to large molecules is with their kinetics. Their distribution to target and clearance from non-target tissues are very rapid, which is the essential requirement of radiopharmaceuticals. In conclusion, the small molecule radiopharmaceuticals generally show excellent biodistribution properties; however, they show poor efficiency of radioisotope delivery. Large molecule or nanoparticle radiopharmaceuticals have advantages of multimodal and efficient delivery, but lower target-to-non-target ratio. Two-step targeting using a bio-orthogonal copper-free click reaction can be a solution of the problem of large molecule or nanoparticle radiopharmaceuticals. The majority of radiopharmaceuticals belong to small molecules of which the molecular weight is less than 2000 Da, and the molecular size is smaller than 2 nm generally. The outstanding feature of the small molecule radiopharmaceuticals compared to large molecules is with their kinetics. Their distribution to target and clearance from non-target tissues are very rapid, which is the essential requirement of radiopharmaceuticals

  2. Application of a small molecule radiopharmaceutical concept to improve kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Dept. of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    Recently, large molecules or nanoparticles are actively studied as radiopharmaceuticals. However, their kinetics is problematic because of a slow penetration through the capillaries and slow distribution to the target. To improve the kinetics, a two-step targeting method can be applied by using small molecules and very rapid copper-free click reaction. Although this method might have limitations such as internalization of the first targeted conjugate, it will provide high target-to-non-target ratio imaging of radiopharmaceuticals. The majority of radiopharmaceuticals belong to small molecules of which the molecular weight is less than 2000 Da, and the molecular size is smaller than 2 nm generally. The outstanding feature of the small molecule radiopharmaceuticals compared to large molecules is with their kinetics. Their distribution to target and clearance from non-target tissues are very rapid, which is the essential requirement of radiopharmaceuticals. In conclusion, the small molecule radiopharmaceuticals generally show excellent biodistribution properties; however, they show poor efficiency of radioisotope delivery. Large molecule or nanoparticle radiopharmaceuticals have advantages of multimodal and efficient delivery, but lower target-to-non-target ratio. Two-step targeting using a bio-orthogonal copper-free click reaction can be a solution of the problem of large molecule or nanoparticle radiopharmaceuticals. The majority of radiopharmaceuticals belong to small molecules of which the molecular weight is less than 2000 Da, and the molecular size is smaller than 2 nm generally. The outstanding feature of the small molecule radiopharmaceuticals compared to large molecules is with their kinetics. Their distribution to target and clearance from non-target tissues are very rapid, which is the essential requirement of radiopharmaceuticals.

  3. Ions, solutes and solvents, oh my!

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Daniel David [Iowa State Univ., Ames, IA (United States)

    2009-08-01

    Modern methods in ab initio quantum mechanics have become efficient and accurate enough to study many gas-phase systems. However, chemists often work in the solution phase. The presence of solvent molecules has been shown to affect reaction mechanisms1, lower reaction energy barriers2, participate in energy transfer with the solute3 and change the physical properties of the solute4. These effects would be overlooked in simple gas phase calculations. Careful study of specific solvents and solutes must be done in order to fully understand the chemistry of the solution phase. Water is a key solvent in chemical and biological applications. The properties of an individual water molecule (a monomer) and the behavior of thousands of molecules (bulk solution) are well known for many solvents. Much is also understood about aqueous microsolvation (small clusters containing ten water molecules or fewer) and the solvation characteristics when bulk water is chosen to solvate a solute. However, much less is known about how these properties behave as the cluster size transitions from the microsolvated cluster size to the bulk. This thesis will focus on species solvated with water clusters that are large enough to exhibit the properties of the bulk but small enough to consist of fewer than one hundred solvent molecules. New methods to study such systems will also be presented.

  4. Organizing and addressing magnetic molecules.

    Science.gov (United States)

    Gatteschi, Dante; Cornia, Andrea; Mannini, Matteo; Sessoli, Roberta

    2009-04-20

    Magnetic molecules ranging from simple organic radicals to single-molecule magnets (SMMs) are intensively investigated for their potential applications in molecule-based information storage and processing. The goal of this Article is to review recent achievements in the organization of magnetic molecules on surfaces and in their individual probing and manipulation. We stress that the inherent fragility and redox sensitivity of most SMM complexes, combined with the noninnocent role played by the substrate, ask for a careful evaluation of the structural and electronic properties of deposited molecules going beyond routine methods for surface analysis. Detailed magnetic information can be directly obtained using X-ray magnetic circular dichroism or newly emerging scanning probe techniques with magnetic detection capabilities.

  5. Ion-Molecule Reaction Dynamics.

    Science.gov (United States)

    Meyer, Jennifer; Wester, Roland

    2017-05-05

    We review the recent advances in the investigation of the dynamics of ion-molecule reactions. During the past decade, the combination of single-collision experiments in crossed ion and neutral beams with the velocity map ion imaging detection technique has enabled a wealth of studies on ion-molecule reactions. These methods, in combination with chemical dynamics simulations, have uncovered new and unexpected reaction mechanisms, such as the roundabout mechanism and the subtle influence of the leaving group in anion-molecule nucleophilic substitution reactions. For this important class of reactions, as well as for many fundamental cation-molecule reactions, the information obtained with crossed-beam imaging is discussed. The first steps toward understanding micro-solvation of ion-molecule reaction dynamics are presented. We conclude with the presentation of several interesting directions for future research.

  6. Phase space structure of triatomic molecules

    International Nuclear Information System (INIS)

    Lu, Z.; Kellman, M.E.

    1997-01-01

    The bifurcation structure is investigated for a Hamiltonian for the three coupled nonlinear vibrations of a highly excited triatomic molecule. The starting point is a quantum Hamiltonian used to fit experimental spectra. This Hamiltonian includes 1:1 Darling endash Dennison resonance coupling between the stretches, and 2:1 Fermi resonance coupling between the stretches and bend. A classical Hamiltonian is obtained using the Heisenberg correspondence principle. Surfaces of section show a pronounced degree of chaos at high energies, with a mixture of chaotic and regular dynamics. The large-scale bifurcation structure is found semianalytically, without recourse to numerical solution of Hamilton close-quote s equations, by taking advantage of the fact that the spectroscopic Hamiltonian has a conserved polyad quantum number, corresponding to an approximate constant of the motion of the molecule. Bifurcation diagrams are analyzed for a number of molecules including H 2 O, D 2 O, NO 2 , ClO 2 , O 3 , and H 2 S. copyright 1997 American Institute of Physics

  7. Solution preparation

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  8. Single Molecule Electronics and Devices

    Science.gov (United States)

    Tsutsui, Makusu; Taniguchi, Masateru

    2012-01-01

    The manufacture of integrated circuits with single-molecule building blocks is a goal of molecular electronics. While research in the past has been limited to bulk experiments on self-assembled monolayers, advances in technology have now enabled us to fabricate single-molecule junctions. This has led to significant progress in understanding electron transport in molecular systems at the single-molecule level and the concomitant emergence of new device concepts. Here, we review recent developments in this field. We summarize the methods currently used to form metal-molecule-metal structures and some single-molecule techniques essential for characterizing molecular junctions such as inelastic electron tunnelling spectroscopy. We then highlight several important achievements, including demonstration of single-molecule diodes, transistors, and switches that make use of electrical, photo, and mechanical stimulation to control the electron transport. We also discuss intriguing issues to be addressed further in the future such as heat and thermoelectric transport in an individual molecule. PMID:22969345

  9. A linear algebraic approach to electron-molecule collisions

    International Nuclear Information System (INIS)

    Collins, L.A.; Schnieder, B.I.

    1982-01-01

    The linear algebraic approach to electron-molecule collisions is examined by firstly deriving the general set of coupled integrodifferential equations that describe electron collisional processes and then describing the linear algebraic approach for obtaining a solution to the coupled equations. Application of the linear algebraic method to static-exchange, separable exchange and effective optical potential, is examined. (U.K.)

  10. Single molecule magnet behaviour in robust dysprosium-biradical complexes.

    Science.gov (United States)

    Bernot, Kevin; Pointillart, Fabrice; Rosa, Patrick; Etienne, Mael; Sessoli, Roberta; Gatteschi, Dante

    2010-09-21

    A Dy-biradical complex was synthesized and characterized down to very low temperature. ac magnetic measurements reveal single molecule magnet behaviour visible without any application of dc field. The transition to the quantum tunneling regime is evidenced. Photophysical and EPR measurements provide evidence of the excellent stability of these complexes in solution.

  11. Self-consistent field theory of polymer-ionic molecule complexation

    OpenAIRE

    Nakamura, Issei; Shi, An-Chang

    2010-01-01

    A self-consistent field theory is developed for polymers that are capable of binding small ionic molecules (adsorbates). The polymer-ionic molecule association is described by Ising-like binding variables, C_(i)^(a)(kΔ)(= 0 or 1), whose average determines the number of adsorbed molecules, nBI. Polymer gelation can occur through polymer-ionic molecule complexation in our model. For polymer-polymer cross-links through the ionic molecules, three types of solutions for nBI are obtained, depending...

  12. Spin tunneling in magnetic molecules

    Science.gov (United States)

    Kececioglu, Ersin

    In this thesis, we will focus on spin tunneling in a family of systems called magnetic molecules such as Fe8 and Mn12. This is comparatively new, in relation to other tunneling problems. Many issues are not completely solved and/or understood yet. The magnetic molecule Fe 8 has been observed to have a rich pattern of degeneracies in its magnetic spectrum. We focus on these degeneracies from several points of view. We start with the simplest anisotropy Hamiltonian to describe the Fe 8 molecule and extend our discussion to include higher order anisotropy terms. We give analytical expressions as much as we can, for the degeneracies in the semi-classical limit in both cases. We reintroduce jump instantons to the instanton formalism. Finally, we discuss the effect of the environment on the molecule. Our results, for all different models and techniques, agree well with both experimental and numerical results.

  13. Experimental decoherence in molecule interferometry

    International Nuclear Information System (INIS)

    Hackermueller, L.; Hornberger, K.; Stibor, A.; Zeilinger, A.; Arndt, M.; Kiesewetter, G.

    2005-01-01

    Full text: We present three mechanisms of decoherence that occur quite naturally in matter wave interferometer with large molecules. One way molecules can lose coherence is through collision with background gas particles. We observe a loss of contrast with increasing background pressure for various types of gases. We can understand this phenomenon quantitatively with a new model for collisional decoherence which corrects older models by a factor of 2 π;. The second experiment studies the thermal emission of photons related to the high internal energy of the interfering molecules. When sufficiently many or sufficiently short photons are emitted inside the interferometer, the fringe contrast is lost. We can continuously vary the temperature of the molecules and compare the loss of contrast with a model based on decoherence theory. Again we find good quantitative agreement. A third mechanism that influences our interference pattern is dephasing due to vibrations of the interference gratings. By adding additional vibrations we study this effect in more detail. (author)

  14. Photoionization of atoms and molecules

    International Nuclear Information System (INIS)

    Samson, J.A.R.

    1976-01-01

    A literature review on the present state of knowledge in photoionization is presented. Various experimental techniques that have been developed to study photoionization, such as fluorescence and photoelectron spectroscopy, mass spectroscopy, are examined. Various atoms and molecules were chosen to illustrate these techniques, specifically helium and xenon atoms and hydrogen molecules. Specialized photoionization such as in positive and negative ions, excited states, and free radicals is also treated. Absorption cross sections and ionization potentials are also discussed

  15. Low pressure tritiation of molecules

    International Nuclear Information System (INIS)

    Moran, T.F.; Powers, J.C.; Lively, M.O.

    1980-01-01

    A method is described of tritiating sensitive biological molecules by depositing molecules of the substance to be tritiated on a supporting substrate in an evacuated vacuum chamber near, but not in the path of, an electron beam which traverses the chamber, admitting tritium gas into the chamber, and subjecting the tritium to the electron beam. Vibrationally excited tritium gas species are generated which collide and react with the substance thus incorporating tritium atoms into the substance. (U.K.)

  16. Osmosis and thermodynamics explained by solute blocking.

    Science.gov (United States)

    Nelson, Peter Hugo

    2017-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult's law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed; others can be tested experimentally or by simulation.

  17. Osmosis and thermodynamics explained by solute blocking

    Science.gov (United States)

    Nelson, Peter Hugo

    2016-01-01

    A solute-blocking model is presented that provides a kinetic explanation of osmosis and ideal solution thermodynamics. It validates a diffusive model of osmosis that is distinct from the traditional convective flow model of osmosis. Osmotic equilibrium occurs when the fraction of water molecules in solution matches the fraction of pure water molecules that have enough energy to overcome the pressure difference. Solute-blocking also provides a kinetic explanation for why Raoult’s law and the other colligative properties depend on the mole fraction (but not the size) of the solute particles, resulting in a novel kinetic explanation for the entropy of mixing and chemical potential of ideal solutions. Some of its novel predictions have been confirmed, others can be tested experimentally or by simulation. PMID:27225298

  18. Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

    Science.gov (United States)

    de Castro, Eduardo da S G; Cassella, Ricardo J

    2016-05-15

    Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Thermal ion-molecule reactions in oxygen-containing molecules

    International Nuclear Information System (INIS)

    Kumakura, Minoru

    1981-02-01

    The energetics of ions and the thermal ion-molecule reactions in oxygen-containing molecules have been studied with a modified time-of-flight mass spectrometer. It was found that the translational energy of ion can be easily obtained from analysis of the decay curve using the time-of-flight mass spectrometer. The condensation-elimination reactions proceeded via cross- and homo-elimination mechanism in which the nature of intermediate-complex could be correlated with the nature of reactant ion. It was elucidated that behavior of poly-atomic oxygen-containing ions on the condensation-elimination reactions is considerably influenced by their oxonium ion structures having functional groups. In addition, the rate constants of the condensation-elimination reactions have affected with the energy state of reactant ion and the dipole moment and/or the polarizability of neutral molecule. It was clarified that the rate constants of the ion-molecule clustering reactions in poly-atomic oxygen-containing molecules such as cyclic ether of six member rings are very large and the cluster ions are stable owing to the large number of vibrational degree of freedom in the cluster ions. (author)

  20. The Molecule Cloud - compact visualization of large collections of molecules

    Directory of Open Access Journals (Sweden)

    Ertl Peter

    2012-07-01

    Full Text Available Abstract Background Analysis and visualization of large collections of molecules is one of the most frequent challenges cheminformatics experts in pharmaceutical industry are facing. Various sophisticated methods are available to perform this task, including clustering, dimensionality reduction or scaffold frequency analysis. In any case, however, viewing and analyzing large tables with molecular structures is necessary. We present a new visualization technique, providing basic information about the composition of molecular data sets at a single glance. Summary A method is presented here allowing visual representation of the most common structural features of chemical databases in a form of a cloud diagram. The frequency of molecules containing particular substructure is indicated by the size of respective structural image. The method is useful to quickly perceive the most prominent structural features present in the data set. This approach was inspired by popular word cloud diagrams that are used to visualize textual information in a compact form. Therefore we call this approach “Molecule Cloud”. The method also supports visualization of additional information, for example biological activity of molecules containing this scaffold or the protein target class typical for particular scaffolds, by color coding. Detailed description of the algorithm is provided, allowing easy implementation of the method by any cheminformatics toolkit. The layout algorithm is available as open source Java code. Conclusions Visualization of large molecular data sets using the Molecule Cloud approach allows scientists to get information about the composition of molecular databases and their most frequent structural features easily. The method may be used in the areas where analysis of large molecular collections is needed, for example processing of high throughput screening results, virtual screening or compound purchasing. Several example visualizations of large

  1. Flexible single molecule simulation of reaction-diffusion processes

    International Nuclear Information System (INIS)

    Hellander, Stefan; Loetstedt, Per

    2011-01-01

    An algorithm is developed for simulation of the motion and reactions of single molecules at a microscopic level. The molecules diffuse in a solvent and react with each other or a polymer and molecules can dissociate. Such simulations are of interest e.g. in molecular biology. The algorithm is similar to the Green's function reaction dynamics (GFRD) algorithm by van Zon and ten Wolde where longer time steps can be taken by computing the probability density functions (PDFs) and then sample from the distribution functions. Our computation of the PDFs is much less complicated than GFRD and more flexible. The solution of the partial differential equation for the PDF is split into two steps to simplify the calculations. The sampling is without splitting error in two of the coordinate directions for a pair of molecules and a molecule-polymer interaction and is approximate in the third direction. The PDF is obtained either from an analytical solution or a numerical discretization. The errors due to the operator splitting, the partitioning of the system, and the numerical approximations are analyzed. The method is applied to three different systems involving up to four reactions. Comparisons with other mesoscopic and macroscopic models show excellent agreement.

  2. Molecule-by-Molecule Writing Using a Focused Electron Beam

    DEFF Research Database (Denmark)

    Van Dorp, Willem F.; Zhang, Xiaoyan; Feringa, Ben L.

    2012-01-01

    atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor...... on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated...

  3. Physics of Complex Polymeric Molecules

    Science.gov (United States)

    Kelly, Joshua Walter

    The statistical physics of complex polymers with branches and circuits is the topic of this dissertation. An important motivation are large, single-stranded (ss) RNA molecules. Such molecules form complex ``secondary" and ``tertiary" structures that can be represented as branched polymers with circuits. Such structures are in part directly determined by the nucleotide sequence and in part subject to thermal fluctuations. The polymer physics literature on molecules in this class has mostly focused on randomly branched polymers without circuits while there has been minimal research on polymers with specific structures and on polymers that contain circuits. The dissertation is composed of three parts: Part I studies branched polymers with thermally fluctuating structure confined to a potential well as a simple model for the encapsidation of viral RNA. Excluded volume interactions were ignored. In Part II, I apply Flory theory to the study of the encapsidation of viral ss RNA molecules with specific branched structures, but without circuits, in the presence of excluded volume interaction. In Part III, I expand on Part II and consider complex polymers with specific structure including both branching and circuits. I introduce a method based on the mathematics of Laplacian matrices that allows me to calculate density profiles for such molecules, which was not possible within Flory theory.

  4. Quantum transport through organic molecules

    International Nuclear Information System (INIS)

    Maiti, Santanu K.

    2007-01-01

    We investigate the electronic transport for the model of benzene-1, 4-dithiolate (BDT) molecule and some other geometric models of benzene molecule attached with two semi-infinite metallic electrodes by the use of Green's function technique. An analytic approach for the electronic transport through the molecular bridges is presented, based on the tight-binding model. Transport of electrons in such molecular bridges is strongly affected by the geometry of the molecules and their coupling strength with the electrodes. Conductance (g) shows resonance peaks associated with the molecular energy eigenstates. In the weak molecule-to-electrodes coupling limit current (I) passing through the molecules shows staircase-like behavior with sharp steps, while, it varies quite continuously in the limit of strong molecular coupling with the applied bias voltage (V). In presence of the transverse magnetic field conductance gives oscillatory behavior with flux φ, threaded by the molecular ring, showing φ 0 ( = ch/e) flux-quantum periodicity. Though conductance changes with the application of transverse magnetic field, but the current-voltage characteristics remain same in presence of this magnetic field for these molecular bridge systems

  5. Soil Solution

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    The characteristics of the soil solution in the root environment in the greenhouse industry differ much from those for field grown crops. This is caused firstly by the growing conditions in the greenhouse, which strongly differ from those in the field and secondly the function attributed to the soil

  6. Seeding Solutions

    International Development Research Centre (IDRC) Digital Library (Canada)

    The Crucible Group operates on the basis of good faith –– producing best effort non-consensus texts. ..... science and technology-based solutions to agricultural production constraints, it is ...... In 1997 researchers at Case Western Reserve Medical School in Ohio (US) ...... Is there a need to update the system-wide IP audit?

  7. Circular Solutions

    NARCIS (Netherlands)

    Annevelink, E.; Bos, H.L.; Meesters, K.P.H.; Oever, van den M.J.A.; Haas, de W.; Kuikman, P.J.; Rietra, R.P.J.J.; Sikirica, N.

    2016-01-01

    The fifth part of this report on Circular Solutions is about the circular principle From Waste to Resource. The purpose of this study is to select promising options for the implementation of this circular principle and to elaborate these options further.

  8. Podcast solutions

    CERN Document Server

    Geoghegan, Michael W

    2005-01-01

    Podcasting is the art of recording radio show style audio tracks, then distributing them to listeners on the Web via podcasting software such as iPodder. From downloading podcasts to producing a track for fun or profit, ""Podcast Solutions"" covers the entire world of podcasting with insight, humor, and the unmatched wisdom of experience.

  9. Dissociation and decay of ultracold sodium molecules

    International Nuclear Information System (INIS)

    Mukaiyama, T.; Abo-Shaeer, J.R.; Xu, K.; Chin, J.K.; Ketterle, W.

    2004-01-01

    The dissociation of ultracold molecules was studied by ramping an external magnetic field through a Feshbach resonance. The observed dissociation energies directly yielded the strength of the atom-molecule coupling. They showed nonlinear dependence on the ramp speed. This was explained by a Wigner threshold law which predicts that the decay rate of the molecules above threshold increases with the density of states. In addition, inelastic molecule-molecule and molecule-atom collisions were characterized

  10. Rotation-vibrational spectra of diatomic molecules and nuclei with Davidson interactions

    CERN Document Server

    Rowe, D J

    1998-01-01

    Complete rotation-vibrational spectra and electromagnetic transition rates are obtained for Hamiltonians of diatomic molecules and nuclei with Davidson interactions. Analytical results are derived by dynamical symmetry methods for diatomic molecules and a liquid-drop model of the nucleus. Numerical solutions are obtained for a many-particle nucleus with quadrupole Davidson interactions within the framework of the microscopic symplectic model. (author)

  11. Small molecule fluoride toxicity agonists.

    Science.gov (United States)

    Nelson, James W; Plummer, Mark S; Blount, Kenneth F; Ames, Tyler D; Breaker, Ronald R

    2015-04-23

    Fluoride is a ubiquitous anion that inhibits a wide variety of metabolic processes. Here, we report the identification of a series of compounds that enhance fluoride toxicity in Escherichia coli and Streptococcus mutans. These molecules were isolated by using a high-throughput screen (HTS) for compounds that increase intracellular fluoride levels as determined via a fluoride riboswitch reporter fusion construct. A series of derivatives were synthesized to examine structure-activity relationships, leading to the identification of compounds with improved activity. Thus, we demonstrate that small molecule fluoride toxicity agonists can be identified by HTS from existing chemical libraries by exploiting a natural fluoride riboswitch. In addition, our findings suggest that some molecules might be further optimized to function as binary antibacterial agents when combined with fluoride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Double photoionisation spectra of molecules

    CERN Document Server

    Eland, John

    2017-01-01

    This book contains spectra of the doubly charged positive ions (dications) of some 75 molecules, including the major constituents of terrestrial and planetary atmospheres and prototypes of major chemical groups. It is intended to be a new resource for research in all areas of molecular spectroscopy involving high energy environments, both terrestrial and extra-terrestrial. All the spectra have been produced by photoionisation using laboratory lamps or synchrotron radiation and have been measured using the magnetic bottle time-of-flight technique by coincidence detection of correlated electron pairs. Full references to published work on the same species are given, though for several molecules these are the first published spectra. Double ionisation energies are listed and discussed in relation to the molecular electronic structure of the molecules. A full introduction to the field of molecular double ionisation is included and the mechanisms by which double photoionisation can occur are examined in detail. A p...

  13. Radical inactivation of a biological sulphydryl molecule

    International Nuclear Information System (INIS)

    Lin, W.S.; Lal, M.; Gaucher, G.M.; Armstrong, D.A.

    1977-01-01

    Reactive species produced from the free radical-induced chain oxidation of low molecular weight sulphydryl-containing molecules in aerated solutions deactivate the sulphydryl-containing enzyme papain, forming both reparable mixed disulphides and non-reparable products. This inactivation is highly efficient for penicillamine and glutathione, but almost negligible with cysteine, which is a protector of papain for [cysteine] / [papain] >= 5 under all conditions used. In the case of glutathione, superoxide dismutase caused only a small reduction in the inactivation and peroxide yields were small, implying that the deactivating species are not .O 2 - but RSOO. radicals or products from them. For penicillamine, however, dimutase was highly effective and the peroxide yields were relatively large, demonstrating that .O 2 - or a radical with similar capabilities for forming H 2 O 2 and being deactivated by dismutase was involved. Although in the presence of dismutase penicillamine is a better protector of non-reparable papain inactivation than glutathione, it suffers from a deficiency in that the papain-penicillamine mixed disulphide, which is always formed, cannot be repaired by spontaneous reaction with RSH molecules. (author)

  14. Technetium-aspirin molecule complexes

    International Nuclear Information System (INIS)

    El-Shahawy, A.S.; Mahfouz, R.M.; Aly, A.A.M.; El-Zohry, M.

    1993-01-01

    Technetium-aspirin and technetium-aspirin-like molecule complexes were prepared. The structure of N-acetylanthranilic acid (NAA) has been decided through CNDO calculations. The ionization potential and electron affinity of the NAA molecule as well as the charge densities were calculated. The electronic absorption spectra of Tc(V)-Asp and Tc(V)-ATS complexes have two characteristic absorption bands at 450 and 600 nm, but the Tc(V)-NAA spectrum has one characteristic band at 450 nm. As a comparative study, Mo-ATS complex was prepared and its electronic absorption spectrum is comparable with the Tc-ATS complex spectrum. (author)

  15. Teaching lasers to control molecules

    International Nuclear Information System (INIS)

    Judson, R.S.; Rabitz, H.

    1992-01-01

    We simulate a method to teach a laser pulse sequences to excite specified molecular states. We use a learning procedure to direct the production of pulses based on ''fitness'' information provided by a laboratory measurement device. Over a series of pulses the algorithm learns an optimal sequence. The experimental apparatus, which consists of a laser, a sample of molecules and a measurement device, acts as an analog computer that solves Schroedinger's equation n/Iexactly, in real time. We simulate an apparatus that learns to excite specified rotational states in a diatomic molecule

  16. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  17. Exotic helium molecules; Molecules exotiques d'helium

    Energy Technology Data Exchange (ETDEWEB)

    Portier, M

    2007-12-15

    We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

  18. Solution Prototype

    DEFF Research Database (Denmark)

    Efeoglu, Arkin; Møller, Charles; Serie, Michel

    2013-01-01

    This paper outlines an artifact building and evaluation proposal. Design Science Research (DSR) studies usually consider encapsulated artifact that have relationships with other artifacts. The solution prototype as a composed artifact demands for a more comprehensive consideration in its systematic...... environment. The solution prototype that is composed from blending product and service prototype has particular impacts on the dualism of DSR’s “Build” and “Evaluate”. Since the mix between product and service prototyping can be varied, there is a demand for a more agile and iterative framework. Van de Ven......’s research framework seems to fit this purpose. Van de Ven allows for an iterative research approach to problem solving with flexible starting point. The research activity is the result between the iteration of two dimensions. This framework focuses on the natural evaluation, particularly on ex...

  19. Neutron scattering study of dilute supercritical solutions

    International Nuclear Information System (INIS)

    Cochran, H.D.; Wignall, G.D.; Shah, V.M.; Londono, J.D.; Bienkowski, P.R.

    1994-01-01

    Dilute solutions in supercritical solvents exhibit interesting microstructures that are related to their dramatic macroscopic behavior. In typical attractive solutions, solutes are believed to be surrounded by clusters of solvent molecules, and solute molecules are believed to congregate in the vicinity of one another. Repulsive solutions, on the other hand, exhibit a local region of reduced solvent density around the solute with solute-solute congregation. Such microstructures influence solubility, partial molar volume, reaction kinetics, and many other properties. We have undertaken to observe these interesting microstructures directly by neutron scattering experiments on dilute noble gas systems including Ar. The three partial structure factors for such systems and the corresponding pair correlation functions can be determined by using the isotope substitution technique. The systems studied are uniquely suited for our objectives because of the large coherent neutron scattering length of the isotope 36 Ar and because of the accurate potential energy functions that are available for use in molecular simulations and theoretical calculations to be compared with the scattering results. We will describe our experiment, the unique apparatus we have built for it, and the neutron scattering results from our initial allocations of beam time. We will also describe planned scattering experiments to follow those with noble gases, including study of long-chain molecules in supercritical solvents. Such studies will involve hydrocarbon mixtures with and without deuteration to provide contrast

  20. 1,3:2,4-Dibenzylidene-D-sorbitol (DBS) and its derivatives--efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future.

    Science.gov (United States)

    Okesola, Babatunde O; Vieira, Vânia M P; Cornwell, Daniel J; Whitelaw, Nicole K; Smith, David K

    2015-06-28

    Dibenzylidene-D-sorbitol (DBS) has been a well-known low-molecular-weight gelator of organic solvents for over 100 years. As such, it constitutes a very early example of a supramolecular gel--a research field which has recently developed into one of intense interest. The ability of DBS to self-assemble into sample-spanning networks in numerous solvents is predicated upon its 'butterfly-like' structure, whereby the benzylidene groups constitute the 'wings' and the sorbitol backbone the 'body'--the two parts representing the molecular recognition motifs underpinning its gelation mechanism, with the nature of solvent playing a key role in controlling the precise assembly mode. This gelator has found widespread applications in areas as diverse as personal care products and polymer nucleation/clarification, and has considerable potential in applications such as dental composites, energy technology and liquid crystalline materials. Some derivatives of DBS have also been reported which offer the potential to expand the scope and range of applications of this family of gelators and endow the nansocale network with additional functionality. This review aims to explain current trends in DBS research, and provide insight into how by combining a long history of application, with modern methods of derivatisation and analysis, the future for this family of gelators is bright, with an increasing number of high-tech applications, from environmental remediation to tissue engineering, being within reach.