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Sample records for purple membrane fragments

  1. Surface-induced lamellar orientation of multilayer membrane arrays. Theoretical analysis and a new method with application to purple membrane fragments.

    PubMed Central

    Clark, N A; Rothschild, K J; Luippold, D A; Simon, B A

    1980-01-01

    The orientation of membrane fragments into a lamellar array by a flat surface is analyzed. This analysis includes processes such as centrifugation and drying and physical effects due to membrane fragment steric interactions, finite size, elasticity, and thermal fluctuations. Several model calculations of optimal orientational order in multilayer membrane arrays are presented. The predictions of a smectic A model agree quantitatively with the measured spatial dependence of the fluctuations in layer orientation in a multilamellar arrays. A new technique, based in part on this analysis, for the preparation of well-oriented multilamellar arrays of natural and artificial membranes, isopotential spin-dry centrifugation, is described. The method involves the use of specially designed inserts for the buckets of a standard vacuum ultracentrifuge. The membrane fragments to be oriented are sedimented from solution or suspension onto a substrate of a convenient material which forms a gravitational isopotential surface at high g. Sedimentation is accompanied by removal of the suspending medium at high g to produce oriented films with a selected degree of solvation. In addition, a method is described whereby small solute molecules can be maintained in constant concentration with the membrane fragments during this process. Initial application of the method to the orientation of purple membrane fragments is described. The degree of orientation obtained in this system is evaluated using freeze-fracture and scanning electron microscopy, optical birefringence, linear dichroism, and microscopy. Images FIGURE 9 FIGURE 10 FIGURE 12 FIGURE 15 PMID:7272434

  2. Electrodichroism of Purple Membrane

    PubMed Central

    Papp, E.; Fricsovszky, G.; Meszéna, G.

    1986-01-01

    The dichroism of purple membrane suspension was measured in dc and ac electric fields. From these measurements three parameters can be obtained: the permanent dipole moment, μ, the electrical polarizability, α, and the retinal angle, δ, (relative to the membrane normal). The functional dependence of the dichroism on the electric field is analyzed. There is a small decrease (∼2°) in retinal angle going from dark adapted to the light adapted form. No measurable difference in μ, α, and δ was found under the photocycle. The dichroism was measured in two different salt solutions (KCl and CaCl2) in the range 0-10 mM. The retinal angle increases from 64° to 68° with increasing ionic strength going through a minimum. This is attributed to the changing (decreasing) inner electric field in the membrane. The polarizability, α, consists of two parts. One component is related to the polarization of the purple membrane and the second component to the ionic cloud. The second component decreases with ion concentration approximately as κ-3 (κ is the Debye parameter) in agreement with a model calculation for the polarization of the ionic cloud. The origin of the slightly ionic strength dependent permanent dipole moment is not well understood. PMID:19431673

  3. Thermodynamic properties of purple membrane.

    PubMed Central

    Marque, J; Eisenstein, L; Gratton, E; Sturtevant, J M; Hardy, C J

    1984-01-01

    We measured the density, expansivity, specific heat at constant pressure, and sound velocity of suspensions of purple membrane from Halobacterium halobium and their constituent buffers. From these quantities we calculated the apparent values for the density, expansivity, adiabatic compressibility, isothermal compressibility, specific heat at constant pressure, and specific heat at constant volume for the purple membrane. These results are discussed with respect to previously reported measurements on globular proteins and lipids. Our data suggest a simple additive model in which the protein and lipid molecules expand and compress independently of each other. However, this simple model seems to fail to describe the specific heat data. Our compressibility data suggest that bacteriorhodopsin in native purple membrane binds less water than many globular proteins in neutral aqueous solution, a finding consistent with the lipid surround of bacteriorhodopsin in purple membrane. PMID:6498271

  4. Oriented adsorption of purple membrane to cationic surfaces.

    PubMed

    Fisher, K A; Yanagimoto, K; Stoeckenius, W

    1978-05-01

    We have investigated the orientation of isolated fragments of Halobacterium halobium purple membrane (PM) adsorbed to poly-L-lysine-treated glass (PL-glass), by quanitative electron microscopy. Three lines of evidence support the conclusion that the cytoplasmic side of the membrane is preferentially absorbed. First, monolayer freeze-fracture reveals nonrandom orientation; more fracture faces (89%) are particulate than smooth. Second, the amount of each membrane surface present can be assayed using polycationic ferritin; 90% of all adsorbed membrane fragments are labeled. Third, it is possible to distinguish two surfaces, "cracked" (the extracellular surface) and "pitted" (the cytoplasmic surface) , in slowly air-dried, platinum-carbon-shadowed membranes. When applied under standard conditions, more than 80% appear cracked. Selection for the cytoplasmic by the cationic substrate suggests that the isolated PM, buffered at pH 7.4 and in the light, has a higher negative charge on its cytoplasmic surface than on its extracellular surface. Nevertheless, cationic ferritin (CF) preferentially adsorbs to the extracellular surface. Orientation provides a striking example of biomembrane surface asymmetry as well as the means to examine the chemical reactivity and physical properties of surfaces of a purified, nonvesicular membrane fragment. PMID:649662

  5. Resonance Raman Spectroscopy of Purple Membrane from Halobacterium Halobium.

    NASA Astrophysics Data System (ADS)

    Argade, Pramod Vasant

    Purple membrane from the halophilic bacteria, Halobacterium halobium, contains the protein, bacteriorhodopsin, which functions as a light transducing proton pump. Understanding the molecular mechanism underlying the functioning of bacteriorhodopsin is a key problem in membrane biophysics. After absorbing a photon, this protein cycles through a series of characteristic intermeidate states and pumps H('+) ions across the membrane. In this way, the energy of the absorbed photon is stored in the electrochemical potential gradient formed across the membrane. This energy is subsequently available for metabolism by the bacterium. Bacteriorhodopsin consists of a retinal chromophore (which is responsible for the purple color) bound to the protein, bacterioopsin, whose sequence is known and consists of 248 amino acid residues. There is evidence that conformational changes in the chromophore may contribute to the proton pumping action. Resonance Raman light scattering provides a selective tool to monitor the conformational changes in the chromophore during the proton pumping cycle. This dissertation consists of applying resonance Raman light scattering in conjunction with a variety of newly developed experimental techniques to gain information about the mode of action of bacteriorhodopsin. By selective isotopic labelling of (epsilon)-amino nitrogen of the lysine residues of the protein, the site of attachment of the chromophore with the protein was verified by in situ measurements. Also, a model proposing a secondary interaction of the chromophore with a lysine residue other than the binding site of the chromophore was tested using this method. Furthermore, by selective isotopic labelling of only a part of the protein the location of the lysine on the protein to which the chromophore is bound, was found by in situ measurements to be the fragment consisting of amino acid residues 72 through 248 of the protein. This is inconsistent with the previously reported binding site at

  6. Light-induced reorientation in the purple membrane.

    PubMed Central

    Wan, C; Qian, J; Johnson, C K

    1993-01-01

    Reorientation of bacteriorhodopsin in the native purple membrane was studied by time-resolved linear dichroism spectroscopy (TRLD) over the millisecond time regime. The time responses observed in TRLD are distinctly different from the isotropic transient absorption (TA) at wavelengths in the range 550-590 nm, where the bacteriorhodopsin ground state absorbs. In contrast, the TA and TRLD responses have nearly identical time dependence at 410 and 690 nm, where the intermediates M and O, respectively, principally contribute. These results demonstrate ground-state bacteriorhodopsin reorientation triggered by the photocycle. The TRLD and TA data are analyzed to test models for reorientational motion. Rotational diffusion of ground-state bacteriorhodopsin cannot account for the details of the data. Rather, the results are shown to be consistent with a reversible reorientation of "spectator" (nonexcited) members of the bacteriorhodopsin trimer in the purple membrane in response to the photocycling member of the trimer. This response may be associated with cooperativity in the trimer. PMID:8218916

  7. Surface pH controls purple-to-blue transition of bacteriorhodopsin. A theoretical model of purple membrane surface.

    PubMed Central

    Szundi, I; Stoeckenius, W

    1989-01-01

    We have developed a surface model of purple membrane and applied it in an analysis of the purple-to-blue color change of bacteriorhodopsin which is induced by acidification or deionization. The model is based on dissociation and double layer theory and the known membrane structure. We calculated surface pH, ion concentrations, charge density, and potential as a function of bulk pH and concentration of mono- and divalent cations. At low salt concentrations, the surface pH is significantly lower than the bulk pH and it becomes independent of bulk pH in the deionized membrane suspension. Using an experimental acid titration curve for neutral, lipid-depleted membrane, we converted surface pH into absorption values. The calculated bacteriohodopsin color changes for acidification of purple, and titrations of deionized blue membrane with cations or base agree well with experimental results. No chemical binding is required to reproduce the experimental curves. Surface charge and potential changes in acid, base and cation titrations are calculated and their relation to the color change is discussed. Consistent with structural data, 10 primary phosphate and two basic surface groups per bacteriorhodopsin are sufficient to obtain good agreement between all calculated and experimental curves. The results provide a theoretical basis for our earlier conclusion that the purple-to-blue transition must be attributed to surface phenomena and not to cation binding at specific sites in the protein. Images FIGURE 1 PMID:2775832

  8. Magnetic birefringence studies of dilute purple membrane suspensions.

    PubMed Central

    Lewis, B A; Rosenblatt, C; Griffin, R G; Courtemanche, J; Herzfeld, J

    1985-01-01

    We have observed the magnetically induced orientation of purple membrane suspensions by measuring the birefringence as a function of concentration and temperature at fields up to 10.5 Tesla (T). At these fields, the orientation approaches saturation even in dilute solutions; therefore, the birefringence data, together with an estimate of the membrane size distribution obtained from electron microscopy, permits one to determine the diamagnetic susceptibility anisotropy. We find delta chi mole = 1.2 +/- 0.3 X 10(-3) erg G-2mol-1 of bacteriorhodopsin. If delta chi were due only to the oriented peptide bonds of the transmembrane alpha helices, this experimental value would indicate that delta K, the anisotropy per mole of peptide bonds, is considerably larger than previously suggested. On the other hand, the large value for delta chi mole of bacteriorhodopsin can also be explained by a net orientation of the aromatic amino acid side chains of bacteriorhodopsin with their planes perpendicular to the membrane surface. In addition, the present data analysis demonstrates the critical dependence of the calculated delta chi value on the values for the membrane size distribution. PMID:3978196

  9. Interfacial electric polarizability of purple membranes in solution.

    PubMed Central

    Todorov, G; Sokerov, S; Stoylov, S P

    1982-01-01

    An investigation of the scattered light (lambda = 632.8 nm) from purple membrane suspensions with different concentrations subjected to external AC and DC electric fields has been carried out. The electric pulses used were in the field strength range 0-3.2 X 10(4) Vm-1 and the frequency range 10 Hz-1 MHz, the pulse duration being less than or equal to 0.5 s. A concentration dependence of the relative changes in the scattered light intensity was obtained, the effect being positive on orienting the suspensions by an AC field at 1 and 10 kHz, and negative in the case of a DC field. The negative effects in the diluted samples decrease and turn positive as the strength of the field increases. The positive effects show the existence of an interfacial polarizability along the plane of the membrane, and the negative ones suggest the presence of a permanent dipole moment (p), perpendicular to the plane of the membrane. The values of gamma (induced polarizability) and p were found to be on the order of 10(-28)-10(-29) Fm2 and 10(-24) Cm, respectively. An explanation in terms of membrane aggregation for the observed dependence on concentration is given. PMID:7139031

  10. Spin-Controlled Photoluminescence in Hybrid Nanoparticles Purple Membrane System

    PubMed Central

    2016-01-01

    Spin-dependent photoluminescence (PL) quenching of CdSe nanoparticles (NPs) has been explored in the hybrid system of CdSe NP purple membrane, wild-type bacteriorhodopsin (bR) thin film on a ferromagnetic (Ni-alloy) substrate. A significant change in the PL intensity from the CdSe NPs has been observed when spin-specific charge transfer occurs between the retinal and the magnetic substrate. This feature completely disappears in a bR apo membrane (wild-type bacteriorhodopsin in which the retinal protein covalent bond was cleaved), a bacteriorhodopsin mutant (D96N), and a bacteriorhodopsin bearing a locked retinal chromophore (isomerization of the crucial C13=C14 retinal double bond was prevented by inserting a ring spanning this bond). The extent of spin-dependent PL quenching of the CdSe NPs depends on the absorption of the retinal, embedded in wild-type bacteriorhodopsin. Our result suggests that spin-dependent charge transfer between the retinal and the substrate controls the PL intensity from the NPs. PMID:27018195

  11. Determination of total proton release in purple membrane suspension by umbelliferone fluorescence quenching technique.

    PubMed

    Sonar, S; Singh, A K

    1992-06-01

    A technique for determining total proton release from purple membrane suspension under steady illumination has been described. Illuminated purple membrane is found to quench the fluorescence life-time of umbelliferone indicating the release of protons in the medium. Besides the "stoichiometric" release of protons from bacteriorhodopsin, there seems to be release of protons from sources other than protonated retinylidene Schiff base moiety also. PMID:1324883

  12. Reversal of the surface charge asymmetry in purple membrane due to single amino acid substitutions.

    PubMed Central

    Hsu, K C; Rayfield, G W; Needleman, R

    1996-01-01

    Twenty-seven mutant bacteriorhodopsin's were screened to determine the PKa for reversal of the permanent electric dipole moment. The photoelectric response of an aqueous purple-membrane suspension was used to determine the direction of the purple-membrane dipole moment as a function of pH. The pK(a) for the dipole reversal of wild-type bacteriorhodopsin is 4.5. Six of the 27 mutant bacteriorhodopsin's were found to have a pK(a) for dipole reversal larger than that of wild-type bacteriorhodopsin. Two of these mutants, L93T and L93W, involve a neutral amino acid substitution in the interior of the protein. The direction of the purple-membrane permanent electric dipole moment is determined by the purple-membrane surface charge asymmetry. We conclude that these two substitutions, which do not involve charge replacement, alter the pK(a) for the reversal of the purple-membrane surface charge asymmetry. We suggest that these changes to the pK(a) are due to altered protein folding at the surface of the purple-membrane induced by single-site substitutions in the protein interior. PMID:9172760

  13. Time-resolved x-ray diffraction study of photostimulated purple membrane.

    PubMed Central

    Frankel, R D; Forsyth, J M

    1985-01-01

    A nanosecond resolution laser-driven x-ray source has been used to perform a time-resolved, x-ray diffraction study of the purple membrane of the Halobacterium halobium. Alterations in diffraction patterns have been observed 1 ms after photostimulation, and are interpreted to show disorder of bacteriorhodopsin packing in the plane of the membrane with little bacteriorhodopsin structural change. PMID:3978209

  14. Analysis of the irreversible process of proton transport in the purple membrane of Halobacterium halobium.

    PubMed

    Hong, T; Manqi, T

    1980-04-01

    The proton transport across biological membrane, accompanied by energy transformation, is closely related with many basic processes involved in the maintenance of life. Active researches are carried out in this field, but so far we have not known a complete calculation. This paper presents a model of an open and closed photon-controlled ion pore with a quantitative analysis of the irreversible process of the proton transport across the purple membrane. Upon absorbing photon by the purple membrane, the deprotonation of the Schiff base causes the ion pore to open, but it will close when it returns to bR570. A set of nonlinear differential equations describing this model is given. The stability of the equations is discussed. The results of the numerical calculation for steady state are found in good agreement with the experimental data of Bakker. PMID:6250213

  15. [Estimation of the Index Value of Dielectric Permeability inside the Membranes of Purple Bacteria].

    PubMed

    Borisov, A Y; Kozlovsky, V S

    2015-01-01

    The joint application of the precise X-ray data for isolated bacteriochlorophyll complexes of reaction centers and the fundamental formulae for the energy of interaction between two equal dipoles enabled us to suggest a new methodical approach for determination of the values of the index of dielectric permeability in the micro volume enclosing special pairs in Rhodobacter sphaeroides reaction centers. The most probable value for this parameter was thus determined within 1.66-1.76. This approach was generalized for the inner layer of the membranes of purple bacteria and yielded the index value about 1.70-1.85. It is argued that this range of dielectric permeability is adequate for bacterial and plant membranes as well. Low magnitude of this parameter contributes to higher efficiency of energy migration from vast light-harvesting chlorophyll "antenna" to the energy converting reaction centers and hence to higher efficiency of the whole photosynthesis. PMID:26394473

  16. Picosecond fluorescence spectroscopy of the purple membrane of Halobacterium halobium in alkaline suspension

    NASA Astrophysics Data System (ADS)

    Kamiya, Narutoshi; Ishikawa, Mitsuru; Kasahara, Kaname; Kaneko, Manabu; Yamamoto, Noritaka; Ohtani, Hiroyuki

    1997-02-01

    The fluorescence lifetime of the light-adapted purple membrane of Halobacterium halobium in alkaline suspension was measured with a femtosecond-pulse laser-synchroscan streak camera system (< 10 ps resolution time, 620 nm excitation) at 22°C. The lifetimes of slow, fast and very fast decay components were found to be 62 ± 2, 9 ± 2 and < 1 ps, respectively. The fastest component is attributed to bacteriorhodopsin (bR 568). We examined the effect of pH and excitation power on the amplitude of the slow component and concluded that its origin is attributable to the Q intermediate, which is a photoproduct of the N intermediate formed in the later stage of the photocycle of bR 568. We found that Q is the same species as pseudo-bacteriorhodopsin (p-bR).

  17. A comparison of the second harmonic generation from light-adapted, dark-adapted, blue, and acid purple membrane.

    PubMed

    Chen, Z; Sheves, M; Lewis, A; Bouevitch, O

    1994-09-01

    The second order nonlinear polarizability and dipole moment changes upon light excitation of light-adapted bacteriorhodopsin (BR), dark-adapted BR, blue membrane, and acid purple membrane have been measured by second harmonic generation. Our results indicate that the dipole moment changes of the retinal chromophore, delta mu, are very sensitive to both the chromophore structure and protein/chromophore interactions. Delta mu of light-adapted BR is larger than that of dark-adapted BR. The acid-induced formation of the blue membrane results in an increase in the delta mu value, and formation of acid purple membrane, resulting from further reduction of pH to 0, returns the delta mu to that of light-adapted BR. The implications of these findings are discussed. PMID:7811928

  18. A comparison of the second harmonic generation from light-adapted, dark-adapted, blue, and acid purple membrane.

    PubMed Central

    Chen, Z; Sheves, M; Lewis, A; Bouevitch, O

    1994-01-01

    The second order nonlinear polarizability and dipole moment changes upon light excitation of light-adapted bacteriorhodopsin (BR), dark-adapted BR, blue membrane, and acid purple membrane have been measured by second harmonic generation. Our results indicate that the dipole moment changes of the retinal chromophore, delta mu, are very sensitive to both the chromophore structure and protein/chromophore interactions. Delta mu of light-adapted BR is larger than that of dark-adapted BR. The acid-induced formation of the blue membrane results in an increase in the delta mu value, and formation of acid purple membrane, resulting from further reduction of pH to 0, returns the delta mu to that of light-adapted BR. The implications of these findings are discussed. PMID:7811928

  19. Guided reconstitution of membrane protein fragments.

    PubMed

    Cohen, Leah S; Arshava, Boris; Kauffman, Sarah; Mathew, Elizabeth; Fracchiolla, Katrina E; Ding, Fa-Xiang; Dumont, Mark E; Becker, Jeffrey M; Naider, Fred

    2014-01-01

    Structural analysis by NMR of G protein-coupled receptors (GPCRs) has proven to be extremely challenging. To reduce the number of peaks in the NMR spectra by segmentally labeling a GPCR, we have developed a Guided Reconstitution method that includes the use of charged residues and Cys activation to drive heterodimeric disulfide bond formation. Three different cysteine-activating reagents: 5-5'-dithiobis(2-nitrobenzoic acid) [DTNB], 2,2'-dithiobis(5-nitropyridine) [DTNP], and 4,4'-dipyridyl disulfide [4-PDS] were analyzed to determine their efficiency in heterodimer formation at different pHs. Short peptides representing the N-terminal (NT) and C-terminal (CT) regions of the first extracellular loop (EL1) of Ste2p, the Saccharomyces cerevisiae alpha-factor mating receptor, were activated using these reagents and the efficiencies of activation and rates of heterodimerization were analyzed. Activation of NT peptides with DTNP and 4-PDS resulted in about 60% yield, but heterodimerization was rapid and nearly quantitative. Double transmembrane domain protein fragments were biosynthesized and used in Guided Reconstitution reactions. A 102-residue fragment, 2TM-tail [Ste2p(G31-I120C)], was heterodimerized with CT-EL1-tail(DTNP) at pH 4.6 with a yield of ∼75%. A 132-residue fragment, 2TMlong-tail [Ste2p(M1-I120C)], was expressed in both unlabeled and (15)N-labeled forms and used with a peptide comprising the third transmembrane domain, to generate a 180-residue segmentally labeled 3TM protein that was found to be segmentally labeled using [(15)N,(1)H]-HSQC analysis. Our data indicate that the Guided Reconstitution method would be applicable to the segmental labeling of a membrane protein with 3 transmembrane domains and may prove useful in the preparation of an intact reconstituted GPCR for use in biophysical analysis and structure determination. PMID:23897574

  20. Effects of light adaptation on the purple membrane structure of Halobacterium halobium.

    PubMed Central

    Becher, B; Cassim, J Y

    1976-01-01

    Absorption, circular dichroism and optical rotatory dispersion of the bacteriorhodopsin containing purple membrane form Halobacterium halobium were studied in regard to the structural stability of this membrane during the photoisomerization of the retinal of the bacteriorhodopsin from the 13-cis to the all-trans configuration. The following conclusions were reached: (a) the macromolecular structure (protein-protein interaction which may result in the possible exciton interaction of the retinal pi-pi* (NV1) transition moments and protein-lipid interaction) are not significantly altered, (b) possibilities of delocalized conformation changes of the apoprotein involving secondary and/or tertiary structure can be ruled out, (c) localized secondary structure conformation changes of the apoprotein must be limited to the involvement of no more than one or two amino acid residues and localized tertiary structure conformation changes of the apoprotein must be limited to a very short segment of the protein chain containing only a few aromatic amino acid residues, and (d) the interaction between the apoprotein and retinal seems to be relatively more pronounced when the retinal is in the all-trans form than the 13-cis from and also the apoprotein seems to impose a more pronounced dissymmetric constraint on the retinal in the all-trans form than in the 13-cis form. PMID:963198

  1. Deposition of Bacteriorhodopsin Protein in a Purple Membrane Form on Nitrocellulose Membranes for Enhanced Photoelectric Response

    PubMed Central

    Kim, Young Jun; Neuzil, Pavel; Nam, Chang-Hoon; Engelhard, Martin

    2013-01-01

    Bacteriorhodopsin protein (bR)-based systems are one of the simplest known biological energy converters. The robust chemical, thermal and electrochemical properties of bR have made it an attractive material for photoelectric devices. This study demonstrates the photoelectric response of a dry bR layer deposited on a nitrocellulose membrane with indium tin oxide (ITO) electrodes. Light-induced electrical current as well as potential and impedance changes of dried bR film were recorded as the function of illumination. We have also tested bR in solution and found that the electrical properties are strongly dependent on light intensity changing locally proton concentration and thus pH of the solution. Experimental data support the assumption that bR protein on a positively charged nitrocellulose membrane (PNM) can be used as highly sensitive photo- and pH detector. Here the bR layer facilitates proton translocation and acts as an ultrafast optoelectric signal transducer. It is therefore useful in applications related to bioelectronics, biosensors, bio-optics devices and current carrying junction devices. PMID:23271605

  2. Domestic wastewater treatment with purple phototrophic bacteria using a novel continuous photo anaerobic membrane bioreactor.

    PubMed

    Hülsen, Tim; Barry, Edward M; Lu, Yang; Puyol, Daniel; Keller, Jürg; Batstone, Damien J

    2016-09-01

    A key future challenge of domestic wastewater treatment is nutrient recovery while still achieving acceptable discharge limits. Nutrient partitioning using purple phototrophic bacteria (PPB) has the potential to biologically concentrate nutrients through growth. This study evaluates the use of PPB in a continuous photo-anaerobic membrane bioreactor (PAnMBR) for simultaneous organics and nutrient removal from domestic wastewater. This process could continuously treat domestic wastewater to discharge limits (<50 mgCOD L(-1), 5 mgN L(-1), 1.0 mgP L(-1)). Approximately 6.4 ± 1.3 gNH4-N and 1.1 ± 0.2 gPO4-P for every 100 gSCOD were removed at a hydraulic retention time of 8-24 h and volumetric loading rates of 0.8-2.5 COD kg m(3) d(-1). Thus, a minimum of 200 mg L(-1) of ethanol (to provide soluble COD) was required to achieve these discharge limits. Microbial community through sequencing indicated dominance of >60% of PPB, though the PPB community was highly variable. The outcomes from the current work demonstrate the potential of PPB for continuous domestic (and possibly industrial) wastewater treatment and nutrient recovery. Technical challenges include the in situ COD supply in a continuous reactor system, as well as efficient light delivery. Addition of external (agricultural or fossil) derived organics is not financially nor environmentally justified, and carbon needs to be sourced internally from the biomass itself to enable this technology. Reduced energy consumption for lighting is technically feasible, and needs to be addressed as a key objective in scaleup. PMID:27232993

  3. Light energy transduction by the purple membrane of halophilic bacteria; Proceedings of the Symposium, San Francisco, Calif., June 6, 1976

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Several aspects of bacteriorhodopsin, the retinal protein component of the purple membranes of Halobacterium halobium, are discussed. Structural studies are presented. Photochemical properties of the protein complex and of its chromophore are described. Proton translocation of bacteriorhodopsin is compared to that of a protein from a thermophilic bacterium. Ionophore activity of bacteriorhodopsin is considered with attention to conformational changes, light dependency, and electrical potential. Amino acid transport is also examined and the light-energy budget is investigated. Bacteriorhodopsin is of interest because of its similarity to rhodopsin, which plays a major role in mammalian vision, and also because its attainability and distinctive characteristics will facilitate studies of certain bacterial physiological functions, such as ion transport and membrane organization.

  4. Semiconductor quantum dots affect fluidity of purple membrane from Halobacterium salinarum through disruption of bacteriorhodopsin trimer organization

    NASA Astrophysics Data System (ADS)

    Bouchonville, Nicolas; Molinari, Michael; Le Cigne, Anthony; Troyon, Michel; Sukhanova, Alyona; Nabiev, Igor R.

    2012-10-01

    Bacteriorhodopsin (bR) is a unique protein of purple membranes (PMs) of the bacterium Halobacterium salinarum. Tight trimers of this integral photochromic protein form a highly ordered 2D hexagonal crystalline lattice within the PMs. Due to strong excitonic interactions between the bR chromophores (retinals) in the protein trimers, PMs exhibit a strong circular dichroism (CD) activity in the region of the retinal absorption band, which allows monitoring the regularity and stability of the bR trimer organization within the membrane. In this study, the effects of semiconductor quantum dots (QDs) on the bR intramembrane organization and the time course of bR monomerization caused by detergents have been analyzed. The results show that the interaction with QDs does not influence the bR structural organization but considerably accelerates the monomerization of the protein by detergents. These data have been confirmed by the results of atomic force microscopy (AFM) followed by Fourier transform analysis, which have shown that interactions with QDs cause an eightfold acceleration of bR monomerization with Triton. The data show that interactions of nanoparticles with biological membranes may modulate the membrane fluidity and the structural organization and function of integral proteins embedded in these membranes.

  5. Picosecond-millisecond dual-time-base spectroscopy of fluorescent photointermediates formed in the purple membrane of Halobacterium halobium

    NASA Astrophysics Data System (ADS)

    Ohtani, Hiroyuki; Kaneko, Manabu; Ishikawa, Mitsuru; Kamiya, Narutoshi; Yamamoto, Noritaka

    1999-01-01

    Dual-time-base fluorometry to measure both fluorescence lifetimes and the reaction kinetics of their origins was applied to the identification of two fluorescence (>660 nm) species T 9ps and T 62ps ( τF=9±2 and 62±2 ps, respectively) in the purple membrane of Halobacterium halobium in the photostationary state. Photocycles were driven with a 532-nm nanosecond laser and the τFs were measured at delay times ( td=0.05-90.5 ms) by a gated streak camera synchronized to a 626-nm picosecond laser. The td dependencies of the fluorescence of T 9ps and T 62ps were identical with the behaviors of the photointermediates O and Q, respectively.

  6. Identification of Genes Affecting Vacuole Membrane Fragmentation in Saccharomyces cerevisiae

    PubMed Central

    Michaillat, Lydie; Mayer, Andreas

    2013-01-01

    The equilibrium of membrane fusion and fission influences the volume and copy number of organelles. Fusion of yeast vacuoles has been well characterized but their fission and the mechanisms determining vacuole size and abundance remain poorly understood. We therefore attempted to systematically characterize factors necessary for vacuole fission. Here, we present results of an in vivo screening for deficiencies in vacuolar fragmentation activity of an ordered collection deletion mutants, representing 4881 non-essential genes of the yeast Saccharomyces cerevisiae. The screen identified 133 mutants with strong defects in vacuole fragmentation. These comprise numerous known fragmentation factors, such as the Fab1p complex, Tor1p, Sit4p and the V-ATPase, thus validating the approach. The screen identified many novel factors promoting vacuole fragmentation. Among those are 22 open reading frames of unknown function and three conspicuous clusters of proteins with known function. The clusters concern the ESCRT machinery, adaptins, and lipases, which influence the production of diacylglycerol and phosphatidic acid. A common feature of these factors of known function is their capacity to change membrane curvature, suggesting that they might promote vacuole fragmentation via this property. PMID:23383298

  7. Two-step mechanism of membrane disruption by Aβ through membrane fragmentation and pore formation.

    PubMed

    Sciacca, Michele F M; Kotler, Samuel A; Brender, Jeffrey R; Chen, Jennifer; Lee, Dong-kuk; Ramamoorthy, Ayyalusamy

    2012-08-22

    Disruption of cell membranes by Aβ is believed to be one of the key components of Aβ toxicity. However, the mechanism by which this occurs is not fully understood. Here, we demonstrate that membrane disruption by Aβ occurs by a two-step process, with the initial formation of ion-selective pores followed by nonspecific fragmentation of the lipid membrane during amyloid fiber formation. Immediately after the addition of freshly dissolved Aβ(1-40), defects form on the membrane that share many of the properties of Aβ channels originally reported from single-channel electrical recording, such as cation selectivity and the ability to be blockaded by zinc. By contrast, subsequent amyloid fiber formation on the surface of the membrane fragments the membrane in a way that is not cation selective and cannot be stopped by zinc ions. Moreover, we observed that the presence of ganglioside enhances both the initial pore formation and the fiber-dependent membrane fragmentation process. Whereas pore formation by freshly dissolved Aβ(1-40) is weakly observed in the absence of gangliosides, fiber-dependent membrane fragmentation can only be observed in their presence. These results provide insights into the toxicity of Aβ and may aid in the design of specific compounds to alleviate the neurodegeneration of Alzheimer's disease. PMID:22947931

  8. Myosin motors fragment and compact membrane-bound actin filaments

    PubMed Central

    Vogel, Sven K; Petrasek, Zdenek; Heinemann, Fabian; Schwille, Petra

    2013-01-01

    Cell cortex remodeling during cell division is a result of myofilament-driven contractility of the cortical membrane-bound actin meshwork. Little is known about the interaction between individual myofilaments and membrane-bound actin filaments. Here we reconstituted a minimal actin cortex to directly visualize the action of individual myofilaments on membrane-bound actin filaments using TIRF microscopy. We show that synthetic myofilaments fragment and compact membrane-bound actin while processively moving along actin filaments. We propose a mechanism by which tension builds up between the ends of myofilaments, resulting in compressive stress exerted to single actin filaments, causing their buckling and breakage. Modeling of this mechanism revealed that sufficient force (∼20 pN) can be generated by single myofilaments to buckle and break actin filaments. This mechanism of filament fragmentation and compaction may contribute to actin turnover and cortex reorganization during cytokinesis. DOI: http://dx.doi.org/10.7554/eLife.00116.001 PMID:23326639

  9. Real-Time UV-Visible Spectroscopy Analysis of Purple Membrane-Polyacrylamide Film Formation Taking into Account Fano Line Shapes and Scattering

    PubMed Central

    Gomariz, María; Blaya, Salvador; Acebal, Pablo; Carretero, Luis

    2014-01-01

    We theoretically and experimentally analyze the formation of thick Purple Membrane (PM) polyacrylamide (PA) films by means of optical spectroscopy by considering the absorption of bacteriorhodopsin and scattering. We have applied semiclassical quantum mechanical techniques for the calculation of absorption spectra by taking into account the Fano effects on the ground state of bacteriorhodopsin. A model of the formation of PM-polyacrylamide films has been proposed based on the growth of polymeric chains around purple membrane. Experimentally, the temporal evolution of the polymerization process of acrylamide has been studied as function of the pH solution, obtaining a good correspondence to the proposed model. Thus, due to the formation of intermediate bacteriorhodopsin-doped nanogel, by controlling the polymerization process, an alternative methodology for the synthesis of bacteriorhodopsin-doped nanogels can be provided. PMID:25329473

  10. Fragmentation of Integral Membrane Proteins in the Gas Phase

    PubMed Central

    2015-01-01

    Integral membrane proteins (IMPs) are of great biophysical and clinical interest because of the key role they play in many cellular processes. Here, a comprehensive top down study of 152 IMPs and 277 soluble proteins from human H1299 cells including 11 087 fragments obtained from collisionally activated dissociation (CAD), 6452 from higher-energy collisional dissociation (HCD), and 2981 from electron transfer dissociation (ETD) shows their great utility and complementarity for the identification and characterization of IMPs. A central finding is that ETD is ∼2-fold more likely to cleave in soluble regions than threshold fragmentation methods, whereas the reverse is observed in transmembrane domains with an observed ∼4-fold bias toward CAD and HCD. The location of charges just prior to dissociation is consistent with this directed fragmentation: protons remain localized on basic residues during ETD but easily mobilize along the backbone during collisional activation. The fragmentation driven by these protons, which is most often observed in transmembrane domains, both is of higher yield and occurs over a greater number of backbone cleavage sites. Further, while threshold dissociation events in transmembrane domains are on average 10.1 (CAD) and 9.2 (HCD) residues distant from the nearest charge site (R, K, H, N-terminus), fragmentation is strongly influenced by the N- or C-terminal position relative to that site: the ratio of observed b- to y-fragments is ∼1:3 if the cleavage occurs >7 residues N-terminal and ∼3:1 if it occurs >7 residues C-terminal to the nearest basic site. Threshold dissociation products driven by a mobilized proton appear to be strongly dependent on not only relative position of a charge site but also N- or C-terminal directionality of proton movement. PMID:24689519

  11. In Vitro excitation of purified membrane fragments by cholinergic agonists : I. Pharmalogical properties of the excitable membrane fragments.

    PubMed

    Kasai, M; Changeux, J P

    1971-03-01

    Excitation of membrane fragments by cholinergic agonists is measuredin vitro by a filtration technique. Membrane fragments which contain high levels of the enzyme acetylcholinesterase and presumably originate from the innervated excitable faces of electroplax are first purified from homogenates of electric organ ofElectrophorus electricus by centrifugation in a sucrose gradient. Then the fragments, which make closed vesicles or microsacs, are equilibrated overnight with a medium containing(22)Na(+). After equilibration of the inside of the microsacs with the outside medium, the suspension is diluted into a nonradioactive medium. The(22)Na(+) content of the microsacs as a function of time is then followed by rapid filtration on Millipore filters. In the presence of cholinergic agonists, the time course of(22)Na(+) release changes: the rate of(22)Na(+) release increases. This increase is blocked byd-tubocurarine and is absent with microsacs derived from the non-innervated inexcitable membrane of the electroplax. The response to cholinergic agonists is thus followed on a completely cell-free system, in a well-defined environment. The dose-response curves to cholinergic agents obtainedin vitro agree, quantitatively, with the dose-response curves recordedin vivo by electrophysiological methods. In particular, the dose-response curve to agonists is sigmoid, the antagonism betweend-tubocurarine and carbamylcholine competitive, and the antagonism between tetracaine and carbamylcholine noncompetitive. The effects of two different affinity labeling reagents on the response to agonists and on the catalytic activity of acetylcholinesterase are followed in parallel on the same microsac preparation. The effects of dithiothreitol and of gramicidin A on the microsacs are studied and are found to be similar to those observedin vivo with the isolated electroplax. PMID:24173287

  12. Photocycles of bacteriorhodopsin in light- and dark-adapted purple membrane studied by time-resolved absorption spectroscopy.

    PubMed Central

    Hofrichter, J; Henry, E R; Lozier, R H

    1989-01-01

    Nanosecond time-resolved absorption spectra have been measured throughout the photocycle of bacteriorhodopsin in both light-adapted and dark-adapted purple membrane (PM). The data from dark-adapted samples are interpretable as the superposition of two photocycles arising independently from the all-trans and 13-cis retinal isomers that coexist in the dark-adapted state. The presence of a photocycle in dark-adapted PM which is indistinguishable from that observed for light-adapted PM under the same experimental conditions is demonstrated by the observation of the same five relaxation rates associated with essentially identical changes in the photoproduct spectra. This cycle is attributed to the all-trans component. The cycle of the 13-cis component is revealed by scaling the data measured for the light-adapted sample and subtracting it from the data on the dark-adapted mixture. At times less than 1 ms, the resulting difference spectra are nearly time-independent. The peak of the difference spectrum is near 600 nm, although there appears to be a slight (approximately 2 nm) blue-shift in the first few microseconds. Subsequently the amplitude of this spectrum decays and the peak of the difference spectrum shifts in two relaxations. Most of the amplitude of the photoproduct difference spectrum (approximately 80%) decays in a single relaxation having a time constant of approximately 35 ms. The difference spectrum remaining after this relaxation peaks at approximately 590 nm and is indistinguishable from the classical light-dark difference spectrum, which we find, in experiments performed on a much longer time scale, to peak at 588 nm. The decay of this remaining photo-product is not resolvable in the nanosecond kinetic experiments, but dark adaptation of a completely light-adapted sample is found to occur exponentially with a relaxation time of approximately 2,000 s under the conditions of our experiments. PMID:2819234

  13. Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

    NASA Astrophysics Data System (ADS)

    Pieper, Jörg; Rusevich, Leonid; Hauß, Thomas; Renger, Gernot

    2016-02-01

    The effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å-1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å-1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657-663).

  14. Lamellar spacing of photosystem II membrane fragments upon dehydration studied by neutron membrane diffraction

    NASA Astrophysics Data System (ADS)

    Pieper, Jörg; Rusevich, Leonid; Hauß, Thomas; Renger, Gernot

    2015-12-01

    The effect of dehydration on the lamellar spacing of photosystem II (PS II) membrane fragments from spinach has been investigated using neutron membrane diffraction at room temperature. The diffraction data reveal a major peak at a scattering vector Q of 0.049 Å-1 at a relative humidity (r.h.) of 90% corresponding to a repeat distance D of about 129 Å. Upon dehydration to 44% r.h., this peak shifts to about 0.060 Å-1 corresponding to a distance of 104.7±2.5 Å. Within experimental error, the latter repeat distance remains almost the same at hydration levels below 44% r.h. indicating that most of the hydration water is removed. This result is consistent with the earlier finding that hydration-induced conformational protein motions in PS II membrane fragments are observed above 44% r.h. and correlated with the onset electron transfer in PS II (Pieper et al. 2008, Eur. Biophys. J. 37: 657-663).

  15. Membrane Disordering is not Sufficient for Membrane Permeabilization by Islet Amyloidogenic Polypeptide: Studies of IAPP(20-29) Fragments

    PubMed Central

    Brender, Jeffrey R.; Heyl, Deborah L.; Samisetti, Shyamprasad; Kotler, Samuel A.; Osborne, Joshua M.; Pesaru, Ranadheer R.; Ramamoorthy, Ayyalusamy

    2013-01-01

    A key factor in the development of type II diabetes is the loss of insulin-producing beta-cells. Human islet amyloid polypeptide protein (human-IAPP) is believed to play a crucial role in this process by forming small aggregates that exhibit toxicity by disrupting the cell membrane. The actual mechanism of membrane disruption is complex and appears to involve an early component before fiber formation and later component associated with fiber formation on the membrane. By comparing the peptide-lipid interactions derived from solid-state NMR experiments of two IAPP fragments that bind the membrane and cause membrane disordering to IAPP derived peptides known to cause significant early membrane permeabilization, we show here that membrane disordering is not likely to be sufficient by itself to cause the early membrane permeabilization observed by IAPP, and may play a lesser role in IAPP membrane disruption than expected. PMID:23493863

  16. Identification of specific restriction fragments associated with a membrane subparticle from Bacillus subtilis.

    PubMed Central

    Sargent, M G; Bennett, M F; Burdett, I D

    1983-01-01

    When lysates of Bacillus subtilis were treated with restriction endonucleases EcoRI or HindIII, almost all of the DNA was released from the major plasma membrane fraction that was sedimentable at low speed. However, a very small part of the released DNA, when centrifuged at high speed, appeared to be bound to small membrane fragments. On agarose gels, this material, prepared with either enzyme, contained only a small number of restriction fragments, and the DNA in the sample hybridized with 11 to 12 EcoRI or HindIII fragments of chromosomal DNA. This DNA was used after nick-translation to screen Charon 4A clone banks for phages containing membrane-bound fragments. One of these was studied in detail. Only a part (about 5 kilobases) of the region present in this clone is important in binding the DNA to the membrane subparticle. Images PMID:6304013

  17. Membrane disordering is not sufficient for membrane permeabilization by islet amyloid polypeptide: studies of IAPP(20-29) fragments.

    PubMed

    Brender, Jeffrey R; Heyl, Deborah L; Samisetti, Shyamprasad; Kotler, Samuel A; Osborne, Joshua M; Pesaru, Ranadheer R; Ramamoorthy, Ayyalusamy

    2013-06-21

    A key factor in the development of type II diabetes is the loss of insulin-producing beta-cells. Human islet amyloid polypeptide protein (human-IAPP) is believed to play a crucial role in this process by forming small aggregates that exhibit toxicity by disrupting the cell membrane. The actual mechanism of membrane disruption is complex and appears to involve an early component before fiber formation and a later component associated with fiber formation on the membrane. By comparing the peptide-lipid interactions derived from solid-state NMR experiments of two IAPP fragments that cause membrane disordering to IAPP derived peptides known to cause significant early membrane permeabilization, we show here that membrane disordering is not likely to be sufficient by itself to cause the early membrane permeabilization observed by IAPP, and may play a lesser role in IAPP membrane disruption than expected. PMID:23493863

  18. Role of the Cationic C-Terminal Segment of Melittin on Membrane Fragmentation.

    PubMed

    Therrien, Alexandre; Fournier, Alain; Lafleur, Michel

    2016-05-01

    The widespread distribution of cationic antimicrobial peptides capable of membrane fragmentation in nature underlines their importance to living organisms. In the present work, we determined the impact of the electrostatic interactions associated with the cationic C-terminal segment of melittin, a 26-amino acid peptide from bee venom (net charge +6), on its binding to model membranes and on the resulting fragmentation. In order to detail the role played by the C-terminal charges, we prepared a melittin analogue for which the four cationic amino acids in positions 21-24 were substituted with the polar residue citrulline, providing a peptide with the same length and amphiphilicity but with a lower net charge (+2). We compared the peptide bilayer affinity and the membrane fragmentation for bilayers prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/1,2-dipalmitoyl-sn-glycero-3-phospho-l-serine (DPPS) mixtures. It is shown that neutralization of the C-terminal considerably increased melittin affinity for zwitterionic membranes. The unfavorable contribution associated with transferring the cationic C-terminal in a less polar environment was reduced, leaving the hydrophobic interactions, which drive the peptide insertion in bilayers, with limited counterbalancing interactions. The presence of negatively charged lipids (DPPS) in bilayers increased melittin binding by introducing attractive electrostatic interactions, the augmentation being, as expected, greater for native melittin than for its citrullinated analogue. The membrane fragmentation power of the peptide was shown to be controlled by electrostatic interactions and could be modulated by the charge carried by both the membrane and the lytic peptide. The analysis of the lipid composition of the extracted fragments from DPPC/DPPS bilayers revealed no lipid specificity. It is proposed that extended phase separations are more susceptible to lead to the extraction of a lipid species in a specific manner

  19. Extensive autolytic fragmentation of membranous versus cytosolic calpain following myocardial ischemia-reperfusion.

    PubMed

    Gilchrist, James S C; Cook, Tom; Abrenica, Bernard; Rashidkhani, Babak; Pierce, Grant N

    2010-05-01

    We investigated calpain activation in the heart during ischemia-reperfusion (I-R) by immunologically mapping the fragmentation patterns of calpain and selected calpain substrates. Western blots showed the intact 78 kDa large subunit of membrane-associated calpain was autolytically fragmented to 56 and 43 kDa signature immunopeptides following I-R. Under these conditions, the 78 kDa calpain large subunit from crude cytosolic fractions was markedly less fragmented, with only weakly stained autolytic peptides detected at higher molecular weights (70 and 64 kDa). Western blots also showed corresponding calpain-like degradation products (150 and 145 kDa) of membrane-associated alpha-fodrin (240 kDa) following I-R, but in crude myofibrils alpha-fodrin degradation occurred in a manner uncharacteristic of calpain. For control hearts perfused in the absence of ischemia, autolytic fragmentation of calpain and calpain-like alpha-fodrin degradation were completely absent from most subcellular fractions. The exception was sarcolemma-enriched membranes, where significant calpain autolysis and calpain-like alpha-fodrin degradation were detected. In purified sarcoplasmic reticulum membranes, RyR2 and SERCA2 proteins were also highly degraded, but for RyR2 this did not occur in a manner characteristic of calpain. When I-R-treated hearts were perfused with peptidyl calpain inhibitors (ALLN or ALLM; 25 micromol/L), calpain autolysis and calpain-like degradation of alpha-fodrin were equally attenuated by each inhibitor. However, only ALLN protected against early loss of developed pressure in hearts following I-R, with no functionally protective effect of ALLM observed. Our studies suggest calpain is preferentially activated at membranes following I-R, possibly contributing to impaired ion channel function implicated by others in I-R injury. PMID:20555428

  20. Lipodisks integrated with weak affinity chromatography enable fragment screening of integral membrane proteins.

    PubMed

    Duong-Thi, Minh-Dao; Bergström, Maria; Edwards, Katarina; Eriksson, Jonny; Ohlson, Sten; Ying, Janet To Yiu; Torres, Jaume; Hernández, Víctor Agmo

    2016-02-01

    Membrane proteins constitute the largest class of drug targets but they present many challenges in drug discovery. Importantly, the discovery of potential drug candidates is hampered by the limited availability of efficient methods for screening drug-protein interactions. In this work we present a novel strategy for rapid identification of molecules capable of binding to a selected membrane protein. An integral membrane protein (human aquaporin-1) was incorporated into planar lipid bilayer disks (lipodisks), which were subsequently covalently coupled to porous derivatized silica and packed into HPLC columns. The obtained affinity columns were used in a typical protocol for fragment screening by weak affinity chromatography (WAC), in which one hit was identified out of a 200 compound collection. The lipodisk-based strategy, which ensures a stable and native-like lipid environment for the protein, is expected to work also with other membrane proteins and screening procedures. PMID:26673836

  1. Evidence for two types of P-700 in membrane fragments from a blue-green alga.

    PubMed

    Hiyama, T; McSwain, B D; Arnon, D I

    1977-04-11

    The mathematical analysis described in the preceding paper (Biochim. Biophys. Acta (1977) 460, 65-75), in which the steady-state photooxidation of P-700 was compared with overall electron flux in Photosystem I chloroplast fragments, was applied to membrane fragments from the blue-gree alga Nostoc muscorum (Strain 7119) noted for their high activity of both Photosystem I and Photosystem II. The same analysis, which gave good agreement between the photooxidation of P-700 and the overall light-induced electron flux (measured as NADP+ reduction) in Photosystem I chloroplast fragments, revealed in the algal membrane fragments two P-700 components: one responding to high light intensity (P-700 HI), the photooxidation of which was in good agreement with the overall electron flux (measured as NADP+ reduction by reduced 2,6-dichlorophenolindophenol), and the other component responding to low light intensity (P-700 LI), the photooxidation of which was not correlated with the reduction of NADP+ by reduced 2,6-dichlorophenolindophenol. PMID:403940

  2. A novel fragment based strategy for membrane active antimicrobials against MRSA.

    PubMed

    Li, Jianguo; Liu, Shouping; Koh, Jun-Jie; Zou, Hanxun; Lakshminarayanan, Rajamani; Bai, Yang; Pervushin, Konstantin; Zhou, Lei; Verma, Chandra; Beuerman, Roger W

    2015-04-01

    Membrane active antimicrobials are a promising new generation of antibiotics that hold the potential to avert antibiotic resistance. However, poor understanding of the action mechanism and the lack of general design principles have impeded their development. Here we extend the concept of fragment based drug design and propose a pharmacophore model based on first principles for the design of membrane active antimicrobials against Gram positive pathogens. Elaborating on a natural xanthone-based hydrophobic scaffold, two derivatives of the pharmacophore model are proposed, and these demonstrate excellent antimicrobial activity. Rigorous molecular dynamics simulations combined with biophysical experiments suggest a three-step mechanism of action (absorption-translocation-disruption) which allows us to identify key factors for the practical optimization of each fragment of the pharmacophore. Moreover, the model matches the structures of several membrane active antimicrobials which are currently in clinical trials. Our model provides a novel and rational approach for the design of bactericidal molecules that target the bacterial membrane. PMID:25582665

  3. Membrane effects of N-terminal fragment of apolipoprotein A-I: a fluorescent probe study.

    PubMed

    Trusova, Valeriya; Gorbenko, Galyna; Girych, Mykhailo; Adachi, Emi; Mizuguchi, Chiharu; Sood, Rohit; Kinnunen, Paavo; Saito, Hiroyuki

    2015-03-01

    The binding of monomeric and aggregated variants of 1-83 N-terminal fragment of apolipoprotein A-I with substitution mutations G26R, G26R/W@8, G26R/W@50 and G26R/W@72 to the model lipid membranes composed of phosphatidylcholine and its mixture with cholesterol has been investigated using fluorescent probes pyrene and Laurdan. Examination of pyrene spectral behavior did not reveal any marked influence of apoA-I mutants on the hydrocarbon region of lipid bilayer. In contrast, probing the membrane effects by Laurdan revealed decrease in the probe generalized polarization in the presence of aggregated proteins. suggesting that oligomeric and fibrillar apoA-I species induce increase in hydration degree and reduction of lipid packing density in the membrane interfacial region. These findings may shed light on molecular details of amyloid cytotoxicity. PMID:25595057

  4. Purple Urine Bag Syndrome.

    PubMed

    Abubacker, Naufal Rizwan Taraganar; Jayaraman, Senthil Manikandan Thirumanilayur; R, Kannan; Sivanesan, Magesh Kumar; Mathew, Renu

    2015-08-01

    Purple urine bag syndrome (PUBS) is a rare disorder seen in elderly persons, wherein the urinary bag and the tubing turn in to purple colour. It is usually seen in patients who are on urinary catheters for a long time. Purple coloured urine occurs due to the accumulation of indigo and indirubin, which are the end products of tryptophan metabolism due to the action of sulfatases and phosphatases formed by bacteria like Providencia, Citrobacter, Enterobacter, Klebsiella etc. We present this interesting phenomenon of purple urine in a young male who was on prolonged urinary catheterization. The urine culture was positive for Providencia and constipation was an added risk factor for the purple urine. The urinary catheter and tubing was changed along with a course of antibiotics which lead to the normalization of the urine colour. PMID:26435987

  5. The purple bag syndrome.

    PubMed

    McSherry, J A

    1980-10-01

    This is an account of an unusual case of purple discoloration of plastic disposable urethral catheters and urine collecting bags. The likely causes are discussed with reference to the analogous situation of purple diapers in children. In this instance it appears that the phenomenon may have been due to the presence of indigo in the urine as a degradation product of tryptophan in the bowel lumen. PMID:21293710

  6. Kinetic analysis of receptor-controlled tracer efflux from sealed membrane fragments

    PubMed Central

    Bernhardt, Julius; Neumann, Eberhard

    1978-01-01

    A detailed kinetic analysis is presented for activator-receptor-mediated efflux of tracer substances from vesicular membrane systems in general and from sealed fragments of excitable membranes in particular. Rate constants and amplitudes, as the primary measurable quantities of the efflux kinetics, are expressed in terms of fundamental properties of vesicular membrane systems containing receptors of chemical gating systems. The experimental determination and theoretical analysis of single contributions to a complex receptor-controlled efflux has been treated for the acetylcholine receptor system; also the effect of “pharmacological densensitization” on efflux is explicitly formulated. The dependence of the measured efflux parameters on the concentration of activators can be used to derive the kinetic and thermodynamic constants for receptor activation and inactivation processes; a general kinetic scheme and two limiting cases are analyzed. The efflux of 22Na from “excitable microsacs” of Torpedo marmorata is treated as an example, and the power of the rigorous analytical method is demonstrated. In particular, the analysis of efflux amplitudes from only a few data points offers an alternative to the longer lasting measurements for obtaining efflux curves when a safety factor is involved, as in the case of tracer ions like 22Na. PMID:16592553

  7. The 43-K protein, v1, associated with acetylcholine receptor containing membrane fragments is an actin-binding protein.

    PubMed Central

    Walker, J H; Boustead, C M; Witzemann, V

    1984-01-01

    Acetylcholine receptor enriched membrane fragments were obtained from the electric organs of Torpedo marmorata. The purified membrane fragments contained several proteins in addition to the acetylcholine receptor subunits. One of these was shown to be actin by means of immune blotting with a monoclonal antibody. Brief treatment of the membranes with pH 11.0 buffer removed actin and the other non-receptor proteins including the receptor-associated 43 000 mol. wt. polypeptide. This polypeptide was shown to bind actin after transferring the proteins from one- and two-dimensional polyacrylamide gels to nitrocellulose paper and incubating the nitrocellulose blots with actin. Specifically bound actin was demonstrated using the monoclonal antibodies to actin. No calcium or calmodulin dependency of binding was observed. The findings suggest that the 43 000 mol. wt. polypeptide is a link between the membrane-bound acetylcholine receptor and the cytoskeleton. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:6389118

  8. Purple Pelisse: a specialty fingerling potato with purple skin and purple flesh

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple Pelisse is a specialty fingerling potato with purple skin and dark purple flesh. It has medium maturity and sets a large number of smooth, small, fingerling-shaped tubers. The tubers have medium specific gravity and high levels of antioxidants. This potato variety is mainly intended for the f...

  9. An Arp2/3 nucleated F-actin shell fragments nuclear membranes at nuclear envelope breakdown in starfish oocytes.

    PubMed

    Mori, Masashi; Somogyi, Kálmán; Kondo, Hiroshi; Monnier, Nilah; Falk, Henning J; Machado, Pedro; Bathe, Mark; Nédélec, François; Lénárt, Péter

    2014-06-16

    Animal cells disassemble and reassemble their nuclear envelopes (NEs) upon each division. Nuclear envelope breakdown (NEBD) serves as a major regulatory mechanism by which mixing of cytoplasmic and nuclear compartments drives the complete reorganization of cellular architecture, committing the cell for division. Breakdown is initiated by phosphorylation-driven partial disassembly of the nuclear pore complexes (NPCs), increasing their permeability but leaving the overall NE structure intact. Subsequently, the NE is rapidly broken into membrane fragments, defining the transition from prophase to prometaphase and resulting in complete mixing of cyto- and nucleoplasm. However, the mechanism underlying this rapid NE fragmentation remains largely unknown. Here, we show that NE fragmentation during NEBD in starfish oocytes is driven by an Arp2/3 complex-nucleated F-actin "shell" that transiently polymerizes on the inner surface of the NE. Blocking the formation of this F-actin shell prevents membrane fragmentation and delays entry of large cytoplasmic molecules into the nucleus. We observe spike-like protrusions extending from the F-actin shell that appear to "pierce" the NE during the fragmentation process. Finally, we show that NE fragmentation is essential for successful reproduction, because blocking this process in meiosis leads to formation of aneuploid eggs. PMID:24909322

  10. Active Fragments from Pro- and Antiapoptotic BCL-2 Proteins Have Distinct Membrane Behavior Reflecting Their Functional Divergence

    PubMed Central

    Guillemin, Yannis; Lopez, Jonathan; Gimenez, Diana; Fuertes, Gustavo; Valero, Juan Garcia; Blum, Loïc; Gonzalo, Philippe; Salgado, Jesùs; Girard-Egrot, Agnès; Aouacheria, Abdel

    2010-01-01

    Background The BCL-2 family of proteins includes pro- and antiapoptotic members acting by controlling the permeabilization of mitochondria. Although the association of these proteins with the outer mitochondrial membrane is crucial for their function, little is known about the characteristics of this interaction. Methodology/Principal Findings Here, we followed a reductionist approach to clarify to what extent membrane-active regions of homologous BCL-2 family proteins contribute to their functional divergence. Using isolated mitochondria as well as model lipid Langmuir monolayers coupled with Brewster Angle Microscopy, we explored systematically and comparatively the membrane activity and membrane-peptide interactions of fragments derived from the central helical hairpin of BAX, BCL-xL and BID. The results show a connection between the differing abilities of the assayed peptide fragments to contact, insert, destabilize and porate membranes and the activity of their cognate proteins in programmed cell death. Conclusion/Significance BCL-2 family-derived pore-forming helices thus represent structurally analogous, but functionally dissimilar membrane domains. PMID:20140092

  11. Detection of Purple Sulfur Bacteria in Purple and Non-purple Dairy Wastewaters.

    PubMed

    Dungan, Robert S; Leytem, April B

    2015-09-01

    The presence of purple bacteria in manure storage lagoons is often associated with reduced odors. In this study, our objectives were to determine the occurrence of purple sulfur bacteria (PSB) in seven dairy wastewater lagoons and to identify possible linkages between wastewater properties and purple blooms. Community DNA was extracted from composited wastewater samples, and a conservative 16S rRNA gene sequence within and genes found in both purple sulfur and nonsulfur bacteria was amplified. Analysis of the genes indicated that all of the lagoons contained sequences that were 92 to 97% similar with . Sequences from a few lagoons were also found to be similar with other PSB, such as sp. (97%), (93-100%), and (95-98%). sequences amplified from enrichment and pure cultures were most similar to (93-96%). Carotenoid pigment concentrations, which were used as an indirect measure of purple bacteria levels in the wastewaters, were found to be positively correlated with salinity, nitrogen, total and volatile solids, and chemical oxygen demand; however, salinity could be the dominant factor influencing purple blooms. Due to the detection of PSB sequences in all lagoons, our findings suggest that the non-purple lagoons may have been purple in the past or may have the potential to become purple in the future. PMID:26436272

  12. Expression, purification and identification of an immunogenic fragment in the ectodomain of prostate-specific membrane antigen

    PubMed Central

    TAO, RONG; NI, ZHENHUA; LIU, CHONG; ZHU, MIN; JI, XIAOWEN; CHEN, XUEMIN; SHEN, JIANGFAN; TU, SHAOHUA

    2016-01-01

    The present study aimed to identify, express and purify an immunogenic fragment in the ectodomain of prostate-specific membrane antigen (PSMA) within a fusion protein. The PSMA amino acid sequence published in National Center for Biotechnology Information GenBank was used to determine sequence homology and immunogenic index analyses, additionally using BLASTN, Protean and ExPASy software to predict the polypeptide sequences of immunogenic epitopes. The gene sequence encoding the ectodomain of the polypeptide immunogenic fragments, containing the identified immunogenic epitopes, was generated using whole-gene synthesis. Prokaryotic expression vector pET-32a-r-ectodomain-PSMA was constructed and the recombinant plasmids were transformed into competent BL21 (DE3) Escherichia coli, which was followed by induction of recombinant protein expression using isopropyl-β-D-thiogalactopyranoside. Fusion proteins were isolated and purified using affinity chromatography and their immune activity was subsequently investigated using western blot analysis. Purified protein was used to immunize BALB/c mice in order to generate polyclonal antibodies, and the binding of polyclonal antibodies to prostate cancer cell lines in vitro was evaluated using flow cytometry. A total of 3 polypeptide fragments with high specificity were identified following analysis using numerous software packages, and the gene sequences encoding regions containing the 2 most immunogenic fragments were synthesized and successfully inserted into the prokaryotic expression vector pET-32a-r-ectodomain-PSMA. The recombinant PSMA protein fragment had a molecular weight of ~50 kDa and 95% purity. Western blot analysis revealed that the r-ectodomain-PSMA fusion protein specifically bound to the anti-PSMA ectodomain monoclonal antibody. Flow cytometry demonstrated that polyclonal antibodies raised against these recombinant proteins could specifically bind to PSMA-positive LNCaP cells, but not to PSMA-negative PC-3

  13. Directly probing redox-linked quinones in photosystem II membrane fragments via UV resonance Raman scattering.

    PubMed

    Chen, Jun; Yao, Mingdong; Pagba, Cynthia V; Zheng, Yang; Fei, Liping; Feng, Zhaochi; Barry, Bridgette A

    2015-01-01

    In photosynthesis, photosystem II (PSII) harvests sunlight with bound pigments to oxidize water and reduce quinone to quinol, which serves as electron and proton mediators for solar-to-chemical energy conversion. At least two types of quinone cofactors in PSII are redox-linked: QA, and QB. Here, we for the first time apply 257-nm ultraviolet resonance Raman (UVRR) spectroscopy to acquire the molecular vibrations of plastoquinone (PQ) in PSII membranes. Owing to the resonance enhancement effect, the vibrational signal of PQ in PSII membranes is prominent. A strong band at 1661 cm(-1) is assigned to ring CC/CO symmetric stretch mode (ν8a mode) of PQ, and a weak band at 469 cm(-1) to ring stretch mode. By using a pump-probe difference UVRR method and a sample jet technique, the signals of QA and QB can be distinguished. A frequency difference of 1.4 cm(-1) in ν8a vibrational mode between QA and QB is observed, corresponding to ~86 mV redox potential difference imposed by their protein environment. In addition, there are other PQs in the PSII membranes. A negligible anharmonicity effect on their combination band at 2130 cm(-1) suggests that the 'other PQs' are situated in a hydrophobic environment. The detection of the 'other PQs' might be consistent with the view that another functional PQ cofactor (not QA or QB) exists in PSII. This UVRR approach will be useful to the study of quinone molecules in photosynthesis or other biological systems. PMID:25791219

  14. Controlled release of human growth hormone fused with a human hybrid Fc fragment through a nanoporous polymer membrane

    NASA Astrophysics Data System (ADS)

    Kim, Eung-Sam; Jang, Do Soo; Yang, Seung Yun; Lee, Mi Nam; Jin, Kyeong Sik; Cha, Hyung Jin; Kim, Jin Kon; Sung, Young Chul; Choi, Kwan Yong

    2013-05-01

    Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG4 to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and structural integrity of hGH. Thus, the nanoporous release device could be a potential delivery system for the long-term controlled release of therapeutic proteins fused with the hybrid Fc fragment.Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG4 to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and

  15. Antimicrobial Peptides: Insights into Membrane Permeabilization, Lipopolysaccharide Fragmentation and Application in Plant Disease Control

    PubMed Central

    Datta, Aritreyee; Ghosh, Anirban; Airoldi, Cristina; Sperandeo, Paola; Mroue, Kamal H.; Jiménez-Barbero, Jesús; Kundu, Pallob; Ramamoorthy, Ayyalusamy; Bhunia, Anirban

    2015-01-01

    The recent increase in multidrug resistance against bacterial infections has become a major concern to human health and global food security. Synthetic antimicrobial peptides (AMPs) have recently received substantial attention as potential alternatives to conventional antibiotics because of their potent broad-spectrum antimicrobial activity. These peptides have also been implicated in plant disease control for replacing conventional treatment methods that are polluting and hazardous to the environment and to human health. Here, we report de novo design and antimicrobial studies of VG16, a 16-residue active fragment of Dengue virus fusion peptide. Our results reveal that VG16KRKP, a non-toxic and non-hemolytic analogue of VG16, shows significant antimicrobial activity against Gram-negative E. coli and plant pathogens X. oryzae and X. campestris, as well as against human fungal pathogens C. albicans and C. grubii. VG16KRKP is also capable of inhibiting bacterial disease progression in plants. The solution-NMR structure of VG16KRKP in lipopolysaccharide features a folded conformation with a centrally located turn-type structure stabilized by aromatic-aromatic packing interactions with extended N- and C-termini. The de novo design of VG16KRKP provides valuable insights into the development of more potent antibacterial and antiendotoxic peptides for the treatment of human and plant infections. PMID:26144972

  16. Detection of purple sulfur bacteria in purple and non-purple dairy wastewaters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple sulfur bacteria (PSB) in livestock wastewaters use reduced sulfur compounds and simple volatile organics as growth factors. As a result, the presence of PSB in manure storage ponds or lagoons is often associated with reduced odors. In this study, our objectives were to use molecular- and cult...

  17. Binding of alpha-bungarotoxin to proteolytic fragments of the alpha subunit of Torpedo acetylcholine receptor analyzed by protein transfer on positively charged membrane filters.

    PubMed Central

    Wilson, P T; Gershoni, J M; Hawrot, E; Lentz, T L

    1984-01-01

    Proteolytic fragments of the alpha subunit of the acetylcholine receptor retain the ability to bind alpha-bungarotoxin following resolution by polyacrylamide gel electrophoresis and immobilization on protein transfers. The alpha subunit of the acetylcholine receptor of Torpedo electric organ was digested with four proteases: Staphylococcus aureus V-8 protease, papain, bromelain, and proteinase K. The proteolytic fragments resolved on 15% polyacrylamide gels were electrophoretically transferred onto positively charged nylon membrane filters. When incubated with 0.3 nM 125I-labeled alpha-bungarotoxin and autoradiographed, the transfers yielded patterns of labeled bands characteristic for each protease. The molecular masses of the fragments binding toxin ranged from 7 to 34 kDa, with major groupings in the 8-, 18-, and 28-kDa ranges. The apparent affinity of the fragments for alpha-bungarotoxin as determined from the IC50 value was 6.7 X 10(-8) M. The labeling of fragments with alpha-bungarotoxin could be inhibited by prior affinity alkylation of receptor-containing membranes with 4-(N-maleimido)-alpha-benzyltrimethylammonium iodide. These findings demonstrate that immobilized proteolytic fragments as small as 1/5 the size of the alpha subunit retain the structural characteristics necessary for binding alpha-bungarotoxin, although the toxin is bound to the fragments with lower affinity than to the native receptor. The effect of affinity ligand alkylation demonstrates that the alpha-bungarotoxin binding site detected on the proteolytic fragments is the same as the affinity-labeled acetylcholine binding site on the intact acetylcholine receptor. Images PMID:6371817

  18. Solubilization and purification of the glucosyltransferase involved in the biosynthesis of teichuronic acid by fragments of Micrococcus luteus cell membranes

    SciTech Connect

    Hildebrandt, K.M.; Anderson, J.S.

    1987-05-01

    Enzymes involved in the biosynthesis of teichuronic acid have been demonstrated in cytoplasmic membrane fragments recovered from lysozyme treated Micrococcus luteus cells. Solubilization of the glucosyltransferase activity was effected with aqueous solutions of Triton X-100, Nonidet P-40, Tween 20, or Thesit. Thesit proved most amenable for recovery of glucosyltransferase activity as well as spectrophotometric protein determinations. Recovery of the glucosyltranferase activity was aided during purification by inclusion of 15% glycerol, 0.75% Thesit, 20 mM magnesium ion and 2 mM 2-mercaptoethanol in all buffers. Glucosyltransferase activity was monitored by the transfer of (/sup 14/C)glucose from UDP-(/sup 14/C)glucose to an artificial acceptor. Although the natural acceptor is presumed to be an undecaprenyl diphosphate-activated oligosaccharide, alternate acceptors such as isolated cell wall fractions containing teichuronic acid served equally well. Highly purified teichuronic acid devoid of peptidoglycan was the most effective alternate acceptor. The glucosyltransferase was purified by ammonium sulfate precipitation followed by ion exchange chromatography on DEAE-cellulose yielding an overall 200-fold increase in specific activity.

  19. Conserved stem fragment from H3 influenza hemagglutinin elicits cross-clade neutralizing antibodies through stalk-targeted blocking of conformational change during membrane fusion.

    PubMed

    Gong, Xin; Yin, He; Shi, Yuhua; Guan, Shanshan; He, Xiaoqiu; Yang, Lan; Yu, Yongjiao; Kuai, Ziyu; Jiang, Chunlai; Kong, Wei; Wang, Song; Shan, Yaming

    2016-04-01

    Currently available influenza vaccines typically fail to elicit/boost broadly neutralizing antibodies due to the mutability of virus sequences and conformational changes during protective immunity, thereby limiting their efficacy. This problem needs to be addressed by further understanding the mechanisms of neutralization and finding the desired neutralizing site during membrane fusion. This study specifically focused on viruses of the H3N2 subtype, which have persisted as a principal source of influenza-related morbidity and mortality in humans since the 1968 influenza pandemic. Through sequence alignment and epitope prediction, a series of highly conserved stem fragments (spanning 47 years) were found and coupled to the Keyhole Limpet Hemocyanin (KLH) protein. By application of a combinatorial display library and crystal structure modeling, a stem fragment immunogen, located at the turning point of the HA neck undergoing conformational change during membrane fusion with both B- and T-cell epitopes, was identified. After synthesis of the optimal stem fragment using a multiple antigen peptide (MAP) system, strong humoral immune responses and cross-clade neutralizing activities against strains from the H3 subtype of group 2 influenza viruses after animal immunizations were observed. By detection of nuclear protein immunofluorescence with acid bypass treatment, antisera raised against MAP4 immunogens of the stem fragment showed the potential to inhibit the conformational change of HA in stem-targeted virus neutralization. The identification of this conserved stem fragment provides great potential for exploitation of this site of vulnerability in therapeutic and vaccine design. PMID:26875772

  20. Purple Pelisse: A specialty fingerling potato with purple skin and flesh and medium specific gravity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple Pelisse is a specialty fingerling potato with purple skin and dark purple flesh. It has medium maturity and sets a large number of smooth, small, fingerling-shaped tubers. The tubers have medium specific gravity and high levels of antioxidants. This potato variety is mainly intended for the f...

  1. Biophysical insights into the membrane interaction of the core amyloid-forming Aβ40 fragment K16-K28 and its role in the pathogenesis of Alzheimer's disease.

    PubMed

    Bera, Swapna; Korshavn, Kyle J; Kar, Rajiv K; Lim, Mi Hee; Ramamoorthy, Ayyalusamy; Bhunia, Anirban

    2016-06-22

    The aggregation of amyloid-β (Aβ) on neuronal membranes is implicated in both neuronal toxicity and the progression of Alzheimer's disease. Unfortunately, the heterogeneous environment that results from peptide aggregation in the presence of lipids makes the details of these pathways difficult to interrogate. In this study, we report an investigation of the membrane interaction of an Aβ fragment (K16LVFFAEDVGSNK28, KK13), which maintains the amyloidogenic nature of the full-length peptide and is implicated in membrane-mediated folding, through a combination of NMR spectroscopy and molecular dynamics simulations. Despite KK13's ability to form amyloids in solution, the monomer remains unstructured in the presence of lipid bilayers, unlike its full-length parent peptide. Additionally, NMR and molecular dynamics simulation results support that the presence of GM1 ganglioside, a lipid which strongly promotes binding between Aβ and lipid bilayers, promotes KK13 binding to but not folding on the membrane. Finally, we show that the peptide partitions between the membrane and aqueous solution based on the hydrophobicity of the N-terminal residues, regardless of lipid composition. These results support previous discoveries suggesting the importance of GM1 ganglioside in exacerbating membrane-driven aggregation while identifying the potential importance of C-terminal residues in membrane binding and folding, which has previously been unclear. PMID:27282693

  2. Angle of the retinal of bacteriorhodopsin in blue membrane

    PubMed Central

    Tóth-Boconádi, R.; Taneva, S. G.; Keszthelyi, L.

    1989-01-01

    The electric dichroism of purple and cation-depleted (blue) membrane was measured in a.c. electric fields at saturation. A decrease of 5.5° in the direction of the chromophore transition moment with respect to the membrane normal was found upon removal of cations from purple membrane. PMID:19431744

  3. Biosynthesis of proteokeratan sulfate in the bovine cornea. 2) Isolation of subcellular membrane fragments from bovine cornea cells with keratan sulfate synthesizing activity.

    PubMed

    Keller, R; Stein, T; Weber, W; Kehrer, T; Stuhlsatz, H W; Greiling, H; Keyserlingk, D G

    1983-03-01

    Cornea cells were isolated from bovine corneae after collagenase treatment. Subcellular fragments were fractionated by density gradient centrifugation. The density gradient run was monitored by determination of the marker enzyme activities for mitochondria, plasma membranes, lysosomes and endoplasmatic reticulum, of the enzyme activities involved in keratan sulfate synthesis and of the protein content. The fractions were further investigated by electron microscopy. Two membrane fractions with keratan sulfate-synthesizing activity (UDP-N-acetylglucosamine:keratan-N-acetylglucosaminyl-transferase, UDPgalactose:keratan galactosyltransferase and keratan sulfotransferase) were detected: a heavy fraction separated from the other organells investigated and a light fraction exhibiting the same density as plasma membranes. The activities of the three enzymes were found in the same density gradient fractions with a similar distribution pattern between the fractions, which suggests a joint localization of these 3 enzymes at the same intracellular sites. PMID:6222957

  4. Effect of radiochemical modification on biodistribution of scFvD2B antibody fragment recognising prostate specific membrane antigen.

    PubMed

    Frigerio, Barbara; Benigni, Fabio; Luison, Elena; Seregni, Ettore; Pascali, Claudio; Fracasso, Giulio; Morlino, Sara; Valdagni, Riccardo; Mezzanzanica, Delia; Canevari, Silvana; Figini, Mariangela

    2015-11-01

    Antibody-based reagents represent a promising strategy as clinical diagnostic tools. Prostate cancer (PCa) is the second-leading cause of death in males in the Western population. There is a presently unmet need for accurate diagnostic tool to localize and define the extent of both primary PCa and occult recurrent disease. One of the most suitable targets for PCa is the prostate-specific membrane antigen (PSMA) recognised by the monoclonal antibody D2B that we re-shaped into the single chain Fv (scFv format). Aim of this study was to evaluate in preclinical in vivo models the target specificity of scFvD2B after labelling with different radionuclides. (111)In radiolabelling was performed via the chelator Bz-NOTA, and (131)I radioiodination was performed using iodogen. The potential for molecular imaging and the biological behaviour of the radiolabelled scFvD2B were evaluated in mice bearing two subcutaneous PCa isogenic cell lines that differed only in PSMA expression. Biodistribution studies were performed at 3, 9, 15 and 24h after injection to determine the optimal imaging time point. A significant kidney accumulation, as percentage of injected dose of tissue (%ID/g), was observed for (111)In-scFvD2B at 3h after injection (45%ID/g) and it was maintained up to 24h (26%ID/g). By contrast, kidney accumulation of (131)I-scFvD2B was only marginally (0.3%ID/g at 24h). At the optimal time point defined between 15h and 24h, regardless of the radionuclide used, the scFvD2B was able to localize significantly better in the PSMA expressing tumours compared to the negative control; with (131)I-scFvD2B yielding a significantly better target/background ratio compared to (111)In-scFvD2B. These data suggest that, besides antigen specificity, chemical modification may affect antibody fragment biodistribution. PMID:26404855

  5. Inhibition of nitrate transport by anti-nitrate reductase IgG fragments and the identification of plasma membrane associated nitrate reductase in roots of barley seedlings

    NASA Technical Reports Server (NTRS)

    Ward, M. R.; Tischner, R.; Huffaker, R. C.

    1988-01-01

    Membrane associated nitrate reductase (NR) was detected in plasma membrane (PM) fractions isolated by aqueous two-phase partitioning from barley (Hordeum vulgare L. var CM 72) roots. The PM associated NR was not removed by washing vesicles with 500 millimolar NaCl and 1 millimolar EDTA and represented up to 4% of the total root NR activity. PM associated NR was stimulated up to 20-fold by Triton X-100 whereas soluble NR was only increased 1.7-fold. The latency was a function of the solubilization of NR from the membrane. NR, solubilized from the PM fraction by Triton X-100 was inactivated by antiserum to Chlorella sorokiniana NR. Anti-NR immunoglobulin G fragments purified from the anti-NR serum inhibited NO3- uptake by more than 90% but had no effect on NO2- uptake. The inhibitory effect was only partially reversible; uptake recovered to 50% of the control after thorough rinsing of roots. Preimmune serum immunoglobulin G fragments inhibited NO3- uptake 36% but the effect was completely reversible by rinsing. Intact NR antiserum had no effect on NO3- uptake. The results present the possibility that NO3- uptake and NO3- reduction in the PM of barley roots may be related.

  6. Automating the Purple Crow Lidar

    NASA Astrophysics Data System (ADS)

    Hicks, Shannon; Sica, R. J.; Argall, P. S.

    2016-06-01

    The Purple Crow LiDAR (PCL) was built to measure short and long term coupling between the lower, middle, and upper atmosphere. The initial component of my MSc. project is to automate two key elements of the PCL: the rotating liquid mercury mirror and the Zaber alignment mirror. In addition to the automation of the Zaber alignment mirror, it is also necessary to describe the mirror's movement and positioning errors. Its properties will then be added into the alignment software. Once the alignment software has been completed, we will compare the new alignment method with the previous manual procedure. This is the first among several projects that will culminate in a fully-automated lidar. Eventually, we will be able to work remotely, thereby increasing the amount of data we collect. This paper will describe the motivation for automation, the methods we propose, preliminary results for the Zaber alignment error analysis, and future work.

  7. Clarification of purple carrot juice: analysis of the fouling mechanisms and evaluation of the juice quality.

    PubMed

    Ennouri, Monia; Ben Hassan, Ines; Ben Hassen, Hanen; Lafforgue, Christine; Schmitz, Philippe; Ayadi, Abdelmoneim

    2015-05-01

    Purple carrot juice was clarified by microfiltration. Two modes of filtration, batch concentration and total recycle were tested and the effect of microfiltration process on permeate flux and membrane fouling was studied. Intrinsic membrane resistance was negligible compared with the fouling resistances, which was less than 5 % of total resistance. Determination of membrane hydraulic permeability showed that water cleaning could permit a recovery of about 7 % of initial hydraulic flux. The analysis of color parameters of feed, permeate and concentrate juice during filtration shows that the a* and b* values decrease for the permeate corresponding respectively to changes from green to red and from blue to yellow. The total sugar and reducing sugars increase in permeate and decrease in concentrate. This work showed that it was possible to clarify the purple carrot juice by microfiltration with a real amelioration of the juice appearance. PMID:25892778

  8. Thermal degradation of anthocyanins from purple potato (Cv. Purple Majesty) and their impact on antioxidant capacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degradation parameters of purified anthocyanins from purple-fleshed potato (Purple Majesty cv.) heated at high temperatures (100 - 150 °C) was determined. Purified anthocyanins, prepared by removing salts, sugars and colorless non-anthocyanin phenolics from the crude extract, were quantified using H...

  9. Effect of a light-induced pH gradient on purple-to-blue and purple-to-red transitions of bacteriorhodopsin

    SciTech Connect

    Nasuda-Kouyama, A.; Fukuda, K.; Iio, T.; Kouyama, T. )

    1990-07-24

    Bacteriorhodopsin-containing vesicles that were able to alkalize the extravesicular medium by greater than 1.5 pH units under illumination, i.e., inside-out vesicles, were reconstituted by reverse-phase evaporation with Halobacterium halobium polar lipids or exogenous phospholipids. Acid titration of a dark-adapted sample was accompanied by a color change from purple to blue (pKa = 2.5-4.5 in 0.15 M K2SO4), and alkali titration resulted in the formation of a red species absorbing maximally at 480 nm (pKa = 7 to greater than 9), the pKa values and the extents of these color changes being dependent on the nature of lipid. When a vesicle suspension at neutral or weakly acidic pH was irradiated by continuous light so that a large pH gradient was generated across the membrane, either a purple-to-blue or a purple-to-red transition took place. The light-induced purple-to-red transition was significant in an unbuffered vesicle suspension and correlated with the pH change in the extravesicular medium. The result suggests that the purple-to-red transition is driven from the extravesicular side, i.e., from the C-terminal membrane surface. In the presence of buffer molecules outside, the dominant color change induced in the light was the purple-to-blue transition, which seemed to be due to a large decrease in the intravesicular pH. But an apparently inconsistent result was obtained when the extravesicular medium was acidified by a HCl pulse, which was accompanied by a rapid color change to blue. We arrived at the following explanation: The two bR isomers, one containing all-trans-retinal and the other 13-cis-retinal, respond differently to pH changes in the extravesicular and the intravesicular medium. In this relation, full light adaptation was not achieved when the light-induced purple-to-blue transition was significant.

  10. PMP1 18-38, a yeast plasma membrane protein fragment, binds phosphatidylserine from bilayer mixtures with phosphatidylcholine: a (2)H-NMR study.

    PubMed

    Roux, M; Beswick, V; Coïc, Y M; Huynh-Dinh, T; Sanson, A; Neumann, J M

    2000-11-01

    PMP1 is a 38-residue plasma membrane protein of the yeast Saccharomyces cerevisiae that regulates the activity of the H(+)-ATPase. The cytoplasmic domain conformation results in a specific interfacial distribution of five basic side chains, thought to strongly interact with anionic phospholipids. We have used the PMP1 18-38 fragment to carry out a deuterium nuclear magnetic resonance ((2)H-NMR) study for investigating the interactions between the PMP1 cytoplasmic domain and phosphatidylserines. For this purpose, mixed bilayers of 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphoserine (POPS) were used as model membranes (POPC/POPS 5:1, m/m). Spectra of headgroup- and chain-deuterated POPC and POPS phospholipids, POPC-d4, POPC-d31, POPS-d3, and POPS-d31, were recorded at different temperatures and for various concentrations of the PMP1 fragment. Data obtained from POPS deuterons revealed the formation of specific peptide-POPS complexes giving rise to a slow exchange between free and bound PS lipids, scarcely observed in solid-state NMR studies of lipid-peptide/protein interactions. The stoichiometry of the complex (8 POPS per peptide) was determined and its significance is discussed. The data obtained with headgroup-deuterated POPC were rationalized with a model that integrates the electrostatic perturbation induced by the cationic peptide on the negatively charged membrane interface, and a "spacer" effect due to the intercalation of POPS/PMP1f complexes between choline headgroups. PMID:11053135

  11. PMP1 18-38, a yeast plasma membrane protein fragment, binds phosphatidylserine from bilayer mixtures with phosphatidylcholine: a (2)H-NMR study.

    PubMed Central

    Roux, M; Beswick, V; Coïc, Y M; Huynh-Dinh, T; Sanson, A; Neumann, J M

    2000-01-01

    PMP1 is a 38-residue plasma membrane protein of the yeast Saccharomyces cerevisiae that regulates the activity of the H(+)-ATPase. The cytoplasmic domain conformation results in a specific interfacial distribution of five basic side chains, thought to strongly interact with anionic phospholipids. We have used the PMP1 18-38 fragment to carry out a deuterium nuclear magnetic resonance ((2)H-NMR) study for investigating the interactions between the PMP1 cytoplasmic domain and phosphatidylserines. For this purpose, mixed bilayers of 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphoserine (POPS) were used as model membranes (POPC/POPS 5:1, m/m). Spectra of headgroup- and chain-deuterated POPC and POPS phospholipids, POPC-d4, POPC-d31, POPS-d3, and POPS-d31, were recorded at different temperatures and for various concentrations of the PMP1 fragment. Data obtained from POPS deuterons revealed the formation of specific peptide-POPS complexes giving rise to a slow exchange between free and bound PS lipids, scarcely observed in solid-state NMR studies of lipid-peptide/protein interactions. The stoichiometry of the complex (8 POPS per peptide) was determined and its significance is discussed. The data obtained with headgroup-deuterated POPC were rationalized with a model that integrates the electrostatic perturbation induced by the cationic peptide on the negatively charged membrane interface, and a "spacer" effect due to the intercalation of POPS/PMP1f complexes between choline headgroups. PMID:11053135

  12. Cloning of a DNA fragment encoding a heme-repressible hemoglobin-binding outer membrane protein from Haemophilus influenzae.

    PubMed Central

    Jin, H; Ren, Z; Pozsgay, J M; Elkins, C; Whitby, P W; Morton, D J; Stull, T L

    1996-01-01

    Haemophilus influenzae is able to use hemoglobin as a sole source of heme, and heme-repressible hemoglobin binding to the cell surface has been demonstrated. Using an affinity purification methodology, a hemoglobin-binding protein of approximately 120 kDa was isolated from H. influenzae type b strain HI689 grown in heme-restricted but not in heme-replete conditions. The isolated protein was subjected to N-terminal amino acid sequencing, and the derived amino acid sequence was used to design corresponding oligonucleotides. The oligonucleotides were used to probe a Southern blot of EcoRI-digested HI689 genomic DNA. A hybridizing band of approximately 4.2 kb was successfully cloned into pUC19. Using a 1.9-kb internal BglII fragment of the 4.2-kb clone as a probe, hybridization was seen in both typeable and nontypeable H. influenzae but not in other bacterial species tested. Following partial nucleotide sequencing of the 4.2-kb insert, a putative open reading frame was subcloned into an expression vector. The host Escherichia coli strain in which the cloned fragment was expressed bound biotinylated human hemoglobin, whereas binding of hemoglobin was not detected in E. coli with the vector alone. In conclusion, we hypothesize that the DNA fragment encoding an approximately 120-kDa heme-repressible hemoglobin-binding protein mediates one step in the acquisition of hemoglobin by H. influenzae in vivo. PMID:8757844

  13. Antiproliferative and cytotoxic effects of purple pitanga (Eugenia uniflora L.) extract on activated hepatic stellate cells.

    PubMed

    Denardin, Cristiane C; Parisi, Mariana M; Martins, Leo A M; Terra, Silvia R; Borojevic, Radovan; Vizzotto, Márcia; Perry, Marcos L S; Emanuelli, Tatiana; Guma, Fátima T C R

    2014-01-01

    The presence of phenolic compounds in fruit- and vegetable-rich diets has attracted researchers' attention due to their health-promoting effects. The objective of this study was to evaluate the effects of purple pitanga (Eugenia uniflora L.) extract on cell proliferation, viability, mitochondrial membrane potential, cell death and cell cycle in murine activated hepatic stellate cells (GRX). Cell viability by 3-(4,5-dimethylthiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was significantly decreased on cells treated with 50 and 100 µg ml(-1) of purple pitanga extract for 48 and 72 h, and the percentage of dead cell stained with 7-amino-actinomycin D was significantly higher in treated cells. The reduction of cell proliferation was dose dependent, and we also observed alterations on cell cycle progression. At all times studied, GRX cells treated with 50 and 100 µg ml(-1) of purple pitanga showed a significant reduction in cellular mitochondrial content as well as a decrease in mitochondrial membrane potential. Furthermore, our results indicated that purple pitanga extract induces early and late apoptosis/necrosis and necrotic death in GRX cells. This is the first report describing the antiproliferative, cytotoxic and apoptotic activity for E. uniflora fruits in hepatic stellate cells. The present study provides a foundation for the prevention and treatment of liver fibrosis, and more studies will be carried to elucidate this effect. PMID:23475531

  14. Structural and biophysical characterization of an epitope-specific engineered Fab fragment and complexation with membrane proteins: implications for co-crystallization.

    PubMed

    Johnson, Jennifer L; Entzminger, Kevin C; Hyun, Jeongmin; Kalyoncu, Sibel; Heaner, David P; Morales, Ivan A; Sheppard, Aly; Gumbart, James C; Maynard, Jennifer A; Lieberman, Raquel L

    2015-04-01

    Crystallization chaperones are attracting increasing interest as a route to crystal growth and structure elucidation of difficult targets such as membrane proteins. While strategies to date have typically employed protein-specific chaperones, a peptide-specific chaperone to crystallize multiple cognate peptide epitope-containing client proteins is envisioned. This would eliminate the target-specific chaperone-production step and streamline the co-crystallization process. Previously, protein engineering and directed evolution were used to generate a single-chain variable (scFv) antibody fragment with affinity for the peptide sequence EYMPME (scFv/EE). This report details the conversion of scFv/EE to an anti-EE Fab format (Fab/EE) followed by its biophysical characterization. The addition of constant chains increased the overall stability and had a negligible impact on the antigen affinity. The 2.0 Å resolution crystal structure of Fab/EE reveals contacts with larger surface areas than those of scFv/EE. Surface plasmon resonance, an enzyme-linked immunosorbent assay, and size-exclusion chromatography were used to assess Fab/EE binding to EE-tagged soluble and membrane test proteins: namely, the β-barrel outer membrane protein intimin and α-helical A2a G protein-coupled receptor (A2aR). Molecular-dynamics simulation of the intimin constructs with and without Fab/EE provides insight into the energetic complexities of the co-crystallization approach. PMID:25849400

  15. Murine membranous nephropathy: immunization with α3(IV) collagen fragment induces subepithelial immune complexes and FcγR-independent nephrotic syndrome.

    PubMed

    Zhang, Jun-Jun; Malekpour, Mahdi; Luo, Wentian; Ge, Linna; Olaru, Florina; Wang, Xu-Ping; Bah, Maimouna; Sado, Yoshikazu; Heidet, Laurence; Kleinau, Sandra; Fogo, Agnes B; Borza, Dorin-Bogdan

    2012-04-01

    Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and a significant cause of end-stage renal disease, yet current therapies are nonspecific, toxic, and often ineffective. The development of novel targeted therapies requires a detailed understanding of the pathogenic mechanisms, but progress is hampered by the lack of a robust mouse model of disease. We report that DBA/1 mice as well as congenic FcγRIII(-/-) and FcRγ(-/-) mice immunized with a fragment of α3(IV) collagen developed massive albuminuria and nephrotic syndrome, because of subepithelial deposits of mouse IgG and C3 with corresponding basement membrane reaction and podocyte foot process effacement. The clinical presentation and histopathologic findings were characteristic of MN. Although immunized mice produced genuine anti-α3NC1 autoantibodies that bound to kidney and lung basement membranes, neither crescentic glomerulonephritis nor alveolitis ensued, likely because of the predominance of mouse IgG1 over IgG2a and IgG2b autoantibodies. The ablation of activating IgG Fc receptors did not ameliorate injury, implicating subepithelial deposition of immune complexes and consequent complement activation as a major effector pathway. We have thus established an active model of murine MN. This model, leveraged by the availability of genetically engineered mice and mouse-specific reagents, will be instrumental in studying the pathogenesis of MN and evaluating the efficacy of novel experimental therapies. PMID:22371398

  16. Structural and biophysical characterization of an epitope-specific engineered Fab fragment and complexation with membrane proteins: implications for co-crystallization

    PubMed Central

    Johnson, Jennifer L.; Entzminger, Kevin C.; Hyun, Jeongmin; Kalyoncu, Sibel; Heaner, David P.; Morales, Ivan A.; Sheppard, Aly; Gumbart, James C.; Maynard, Jennifer A.; Lieberman, Raquel L.

    2015-01-01

    Crystallization chaperones are attracting increasing interest as a route to crystal growth and structure elucidation of difficult targets such as membrane proteins. While strategies to date have typically employed protein-specific chaperones, a peptide-specific chaperone to crystallize multiple cognate peptide epitope-containing client proteins is envisioned. This would eliminate the target-specific chaperone-production step and streamline the co-crystallization process. Previously, protein engineering and directed evolution were used to generate a single-chain variable (scFv) antibody fragment with affinity for the peptide sequence EYMPME (scFv/EE). This report details the conversion of scFv/EE to an anti-EE Fab format (Fab/EE) followed by its biophysical characterization. The addition of constant chains increased the overall stability and had a negligible impact on the antigen affinity. The 2.0 Å resolution crystal structure of Fab/EE reveals contacts with larger surface areas than those of scFv/EE. Surface plasmon resonance, an enzyme-linked immunosorbent assay, and size-exclusion chromatography were used to assess Fab/EE binding to EE-tagged soluble and membrane test proteins: namely, the β-barrel outer membrane protein intimin and α-helical A2a G protein-coupled receptor (A2aR). Molecular-dynamics simulation of the intimin constructs with and without Fab/EE provides insight into the energetic complexities of the co-crystallization approach. PMID:25849400

  17. The Purple Rose of Virgo

    NASA Astrophysics Data System (ADS)

    2007-03-01

    Until now NGC 5584 was just one galaxy among many others, located to the West of the Virgo Cluster. Known only as a number in galaxy surveys, its sheer beauty is now revealed in all its glory in a new VLT image. Since 1 March, this purple cosmic rose also holds the brightest stellar explosion of the year, known as SN 2007af. Located about 75 million light years away towards the constellation Virgo ('the Virgin'), NGC 5584 is a galaxy slightly smaller than the Milky Way. It belongs, however, to the same category: both are barred spirals. ESO PR Photo 16/07 ESO PR Photo 16/07 The Purple Rose of Virgo Spiral galaxies are composed of a 'bulge' and a flat disc. The bulge hosts old stars and usually a central supermassive black hole. Younger stars reside in the disc, forming the characteristic spiral structures from which the galaxies get their name. Barred spirals are crossed by a bright band of stars. In 2000, using ESO's Very Large Telescope, astronomers discovered the smallest, faintest, and most massive spirals (see ESO PR 12/00 and 25/00). In this amazing new image of NGC 5584 two dominant spiral arms are clearly visible, while the others are deformed, probably due to interactions with other galaxies. Luminous patches are spread all over the disc, indicating that stars are being formed in this gigantic rose at a frantic pace. Something even brighter, however, catches the eye in this picture. Any image taken before the end of February would not have shown the luminous spot located at the lower right of the galaxy's centre. As can be seen, the newly found object is much brighter than the centre of the galaxy itself. Its name? SN 2007af, the 32nd supernova discovered this year. Its presence signals the dramatic death of a star with a mass comparable to that of the Sun. SN 2007af, the brightest supernova of the year (so far), was discovered on 1 March by the Japanese supernova hunter Koichi Itagaki. He pointed his 60-centimetre telescope towards the Virgo constellation

  18. Fire and nitrogen effects on purple threeawn invaded plant communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple threeawn (Aristida purpurea) is a native grass capable of rapidly increasing on rangelands, where it forms near monocultures, and alters succession. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, reducing over...

  19. Fire and nitrogen effects on purple threeawn invaded plant communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple threeawn (Aristida purpurea) is a native grass capable of rapidly increasing on rangelands, forming near monocultures, and arresting ecological succession. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, leadin...

  20. Purple Urine Bag Syndrome- An Alarming Situation

    PubMed Central

    Faridi, M S; Mibang, Naloh; Shantajit, N; Somarendra, Khumukchum

    2016-01-01

    Purple urine bag syndrome (PUBS) is an uncommon condition that occurs mainly in chronically catheterized patient and associated with urinary tract infection. It is characterised by purple discolouration of urine bag which leads to significant stress and anxiety to patient, care takers and health workers, so awareness regarding this condition is of utmost importance. In our report, an old gentleman with Benign Prostate Hyperplasia (BPH) on per urethral catheter (PUC) with past history of recurrent urinary tract infection developed burning micturition of urine with purple discoloration of urine bag. After proper antibiotic and catheter changed, discoloration subsided. In India, as life expectancy and geriatric care is improving, more patients are on PUC for various diseases. So, the incidence of PUBS will increase and awareness is required about the condition and its management. PMID:27042522

  1. Recognizing purple bag syndrome at first look.

    PubMed

    Canavese, Caterina; Airoldi, Andrea; Quaglia, Marco; Barbè, Maria Cristina; Brustia, Maddalena; Vidali, Matteo; Bagnati, Marco; Andreone, Stefano; Corrà, Tjibbo; Sciarrabba, Calogera; Bellomo, Giorgio; Stratta, Piero

    2013-01-01

    Purple urine bag syndrome is a clinical entity first described in 1978. Its typical discoloration is worrying for clinicians. In the past, these patients sometimes reached the emergency unit only because of this exceptional worrying urinary sign and underwent invasive diagnostic examinations including cystoscopy, without any abnormal finding. It is now clear that this astonishing phenomenon of double discoloration of the urine, appearing purple in the bag and dark blue in the test tube, results from the formation of 2 different pigments (indirubin and indigo) in very alkaline urines due to enzymes produced by gram-negative bacteria, such as indoxyl phosphatase/sulfatase, which can convert urinary metabolites of dietary tryptophan. Practicing physicians should identify purple urine bag syndrome as a usually benign medical condition diagnosed in asymptomatic patients, which only requires treatment of bacteriuria with antibiotics, prevention of constipation, substitution of catheter and acidification of the urine. After these measures, urine typically returns to its normal color. PMID:22941873

  2. Purple Urine Bag Syndrome- An Alarming Situation.

    PubMed

    Faridi, M S; Rahman, Md Jawaid; Mibang, Naloh; Shantajit, N; Somarendra, Khumukchum

    2016-02-01

    Purple urine bag syndrome (PUBS) is an uncommon condition that occurs mainly in chronically catheterized patient and associated with urinary tract infection. It is characterised by purple discolouration of urine bag which leads to significant stress and anxiety to patient, care takers and health workers, so awareness regarding this condition is of utmost importance. In our report, an old gentleman with Benign Prostate Hyperplasia (BPH) on per urethral catheter (PUC) with past history of recurrent urinary tract infection developed burning micturition of urine with purple discoloration of urine bag. After proper antibiotic and catheter changed, discoloration subsided. In India, as life expectancy and geriatric care is improving, more patients are on PUC for various diseases. So, the incidence of PUBS will increase and awareness is required about the condition and its management. PMID:27042522

  3. Antimicrobial action of histone H2B in Escherichia coli: evidence for membrane translocation and DNA-binding of a histone H2B fragment after proteolytic cleavage by outer membrane proteinase T.

    PubMed

    Kawasaki, Hiroaki; Koyama, Takumi; Conlon, J Michael; Yamakura, Fumiyuki; Iwamuro, Shawichi

    2008-01-01

    Previous studies have led to the isolation of histone H2B with antibacterial properties from an extract of the skin of the Schlegel's green tree frog Rhacophorus schlegelii and it is now demonstrated that the intact peptide is released into norepinephrine-stimulated skin secretions. In order to investigate the mechanism of action of this peptide, a maltose-binding protein (MBP)-fused histone H2B (MBP-H2B) conjugate was prepared and subjected to antimicrobial assay. The fusion protein showed bacteriostatic activity against Escherichia coli strain JCM5491 with a minimum inhibitory concentration of 11 microM. The lysate prepared from JCM5491 cells was capable of fragmenting MBP-H2B within the histone H2B region, but the lysate from the outer membrane proteinase T (OmpT) gene-deleted BL21(DE3) cells was not. FITC-labeled MBP-H2B (FITC-MBP-H2B) penetrated into the bacterial cell membrane of JCM5491 and ompT-transformed BL21(DE3) cells, but not into ompT-deleted BL21(DE3) cells. Gel retardation assay using MBP-H2B-deletion mutants indicated that MBP-H2B bound to DNA at a site within the N-terminal region of histone H2B. Consequently, it is proposed that the antimicrobial action of histone H2B involves, at least in part, penetration of an OmpT-produced N-terminal histone H2B fragment into the bacterial cell membrane with subsequent inhibition of cell functions. PMID:18706965

  4. Halosulfuron reduces purple nutsedge (Cyperus rotundus) tuber production and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple nutsedge is one of the most troublesome weeds of fresh-market vegetable crops in the Southern U.S. A perennial weed, purple nutsedge reproduces vegetatively by producing chains of tubers. Halosulfuron is an effective means of controlling purple nutsedge foliage and is registered for use in ...

  5. Purple glove syndrome: a dreadful complication of intravenous phenytoin administration

    PubMed Central

    Lalla, Rakesh; Malhotra, Hardeep Singh; Garg, Ravindra Kumar; Sahu, Ritesh

    2012-01-01

    Purple glove syndrome is an uncommon but dreaded complication of intravenous phenytoin administration characterised by pain, oedema and purple-blue discolouration of the limb distal to the site of injection. We describe a 37-year-old gentleman having the characteristic purple glove appearance after phenytoin loading, and discuss the salient features of this syndrome highlighting the pathophysiological and preventive aspects. PMID:22922927

  6. Characterization of the quinones in purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yuuka; Kawakami, Tomoaki; Yu, Long-Jiang; Yoshimura, Miku; Kobayashi, Masayuki; Wang-Otomo, Zheng-Yu

    2015-07-01

    Quinone distributions in the thermophilic purple sulfur bacterium Thermochromatium tepidum have been investigated at different levels of the photosynthetic apparatus. Here we show that, on average, the intracytoplasmic membrane contains 18 ubiquinones (UQ) and 4 menaquinones (MQ) per reaction center (RC). About one-third of the quinones are retained in the light-harvesting-reaction center core complex (LH1-RC) with a similar ratio of UQ to MQ. The numbers of quinones essentially remains unchanged during crystallization of the LH1-RC. There are 1-2 UQ and 1 MQ associated with the RC-only complex in the purified solution sample. Our results suggest that a large proportion of the quinones are confined to the core complex and at least five UQs remain invisible in the current LH1-RC crystal structure. PMID:26048701

  7. Murine membranous nephropathy: Immunization with α3(IV) collagen fragment induces subepithelial immune complexes and FcγR-independent nephrotic syndrome

    PubMed Central

    Zhang, Jun-Jun; Malekpour, Mahdi; Luo, Wentian; Ge, Linna; Olaru, Florina; Wang, Xu-Ping; Bah, Maimouna; Sado, Yoshikazu; Heidet, Laurence; Kleinau, Sandra; Fogo, Agnes B.; Borza, Dorin-Bogdan

    2012-01-01

    Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and a significant cause of end-stage renal disease, yet current therapies are non-specific, toxic, and often ineffective. The development of novel targeted therapies requires a detailed understanding of the pathogenic mechanisms, but progress is hampered by the lack of a robust mouse model of disease. We report that DBA/1 mice as well as congenic FcγRIII−/− and FcRγ−/− mice immunized with a fragment of α3(IV) collagen developed massive albuminuria and nephrotic syndrome, due to subepithelial deposits of mouse IgG and C3 with corresponding basement membrane reaction and podocyte foot process effacement. The clinical presentation and histopathologic findings were characteristic of MN. Even though immunized mice produced genuine anti-α3NC1 autoAbs which bound to kidney and lung basement membranes, neither crescentic glomerulonephritis nor alveolitis ensued, likely due to the predominance of mIgG1 over mIgG2a and mIgG2b autoAbs. The ablation of activating IgG Fc receptors did not ameliorate injury, implicating subepithelial deposition of immune complexes and consequent complement activation as a major effector pathway. We have thus established an active model of murine MN. This model, leveraged by the availability of genetically engineered mice and mouse-specific reagents, will be instrumental for studying the pathogenesis of MN and for evaluating the efficacy of novel experimental therapies. PMID:22371398

  8. Fluidity of the lipids next to the acetylcholine receptor protein of torpedo membrane fragments. Use of amphiphilic reversible spin-labels.

    PubMed

    Bienvenüe, A; Rousselet, A; Kato, G; Devaux, P F

    1977-03-01

    Choline esters of spin-labeled fatty acids (long-chain acylcholines) were used to probe the hydrophobic environment of the acetylcholine receptor protein in membrane fragments from Torpedo marmorata. These spin-labels competitively inhibit the binding of [3H]acetylcholine to the receptor site. Their inhibition constants (KI) were close to 200 nM. At the high membrane concentration required for electron spin resonance (ESR) experiments, the apparent inhibition constants (KIapp) differed from KI determined by using dilute membrane concentration. This is due to the amphiphilic character of long-chain acylcholine. For most spin-labels used, only difference ESR spectroscopy provided reliable spectra corresponding to receptor-bound spin-labeled acylcholines. Acetylcholine receptor agonists and antagonists displaced the acylcholine from the receptor sites, whereas choline had only a weak effect. This produced a modification in the ESR spectra of the bound acylcholines and provided evidence that the acylcholines bound to the receptor sites in a specific manner. The interpretation of the spectra of receptor-bound spin-labels favored a strong barrier to the motion of the probe when attached to the middle of the acyl chain. However, when the probe was close to the methyl terminal of a stearoylcholine molecule a much greater fluidity was found. Short-range spin-spin interactions were created between spin-labels bound to the receptor site and spin-labels in a fluid phase. This indicates that lipids next to the receptor protein are not completely immobilized in spite of the semicrystalline organization of the proteins in the postsynaptic region. PMID:191058

  9. Photocurrent response of bacteriorhodopsin adsorbed on bimolecular lipid membranes.

    PubMed

    Seta, P; Ormos, P; d'Epenoux, B; Gavach, C

    1980-06-10

    The photo response of bacteriorhodopsin adsorbed on a bimolecular lipid membrane has been investigated using short-circuit current measurements. The results revealed a biphasic current vs. time curve for the photocurrent at pH values of approx. 7. This phenomenon could be modified by altering either the value of the external applied electrical field or the proton concentration differences. The observed effects of the external applied voltage, pH gradient and lipophilic proton carriers enabled us to conclude that the bacteriorhodopsin can be adsorbed in two different states, which give rise to a pumping effect and a flux of protons in opposite directions. A theoretical analysis of the photocycle in relation to the electrical field which acts on the proton uptake and release is proposed. The main effect of this field is to diminish the pumping rate due to the proton motive force resulting from the creation of space-charge in the vicinity of purple membrane fragments. PMID:7388016

  10. [Purple urine bag syndrome: a case report].

    PubMed

    Lazimy, Yaël; Delotte, Jérôme; Machiavello, Jean-Christophe; Lallement, Michel; Imbenotte, Michel; Bongain, André

    2007-06-01

    The authors report a case of dark purple urine in a woman with bowel obstruction and bilateral percutaneous nephrostomy urinary diversion for 30 years. This colour was due to the presence of high urinary concentrations of 3-indoxyl sulphate due to the enzymatic activity of Providencia rettgeri. A favourable course was observed in response to antibiotics. PMID:17634003

  11. The One in the Purple Suit.

    ERIC Educational Resources Information Center

    Sargeant, Hope

    2003-01-01

    In this article, a parent of a gifted child muses on the challenges of raising her daughter, coping with her daughter's frustrations, her decision to stay home, and her brief envy of a doppelganger, a professional in a purple suit. (CR)

  12. Detergent-type membrane fragmentation by MSI-78, MSI-367, MSI-594, and MSI-843 antimicrobial peptides and inhibition by cholesterol: a solid-state nuclear magnetic resonance study.

    PubMed

    Lee, Dong-Kuk; Bhunia, Anirban; Kotler, Samuel A; Ramamoorthy, Ayyalusamy

    2015-03-17

    Multidrug resistance against the existing antibiotics is becoming a global threat, and any potential drug that can be designed using cationic antimicrobial peptides (AMP) could be an alternate solution to alleviate this existing problem. The mechanism of action of killing bacteria by an AMP differs drastically in comparison to that of small molecule antibiotics. The main target of AMPs is to interact with the lipid bilayer of the cell membrane and disrupt it to kill bacteria. Consequently, the modes of membrane interaction that lead to the selectivity of an AMP are very important to understand. Here, we have used different membrane compositions, such as negatively charged, zwitterionic, or mixed large unilamellar vesicles (LUVs), to study the interaction of four different synthetically designed cationic, linear antimicrobial peptides: MSI-78 (commercially known as pexiganan), MSI-367, MSI-594, and MSI-843. Our solid-state nuclear magnetic resonance (NMR) experiments confirmed that the MSI peptides fragmented LUVs through a detergent-like carpet mechanism depending on the amino acid sequence of the MSI peptide and/or the membrane composition of LUVs. Interestingly, the fragmented lipid aggregates such as SUVs or micelles are sufficiently small to produce an isotropic peak in the (31)P NMR spectrum. These fragmented lipid aggregates contain only MSI peptides bestowed with lipid molecules as confirmed by NMR in conjunction with circular dichroism spectroscopy. Our results also demonstrate that cholesterol, which is present only in the eukaryotic cell membrane, inhibits the MSI-induced fragmentation of LUVs, suggesting that the MSI peptides can discriminate the bacteria and the eukaryotic cell membranes, and this selectivity could be used for further development of novel antibiotics. PMID:25715195

  13. Nobel lecture. The photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis.

    PubMed Central

    Deisenhofer, J; Michel, H

    1989-01-01

    In our lectures we first describe the history and methods of membrane protein crystallization, before we show how the structure of the photosynthetic reaction centre from the purple bacterium Rhodopseudomonas viridis was solved. Then the structure of this membrane protein complex is correlated with its function as a light-driven electron pump across the photosynthetic membrane. Finally we draw conclusions on the structure of the photosystem II reaction centre from plants and discuss the aspects of membrane protein structure. Sections 1 (crystallization), 4 (conclusions on the structure of photosystem II reaction centre and evolutionary aspects) and 5 (aspects of membrane protein structure) were presented and written by H.M., Sections 2 (determination of the structure) and 3 (structure and function) by J.D. We have arranged the paper in this way in order to facilitate continuous reading. Images PMID:2676514

  14. Functions of a new photoreceptor membrane. [energy conversion via halobacteria rhodopsin changes

    NASA Technical Reports Server (NTRS)

    Oesterhelt, D.; Stoeckenius, W.

    1973-01-01

    In the investigation of light responses on halobacteria phototaxis; ATP synthesis; and changes in O2 consumption, purple membrane biosynthesis, and proton translocation were found. The last three effects are discussed, which suggest that the purple membrane may function as an energy-coupling membrane for light. It is also suggested that purple membrane, through cyclic light-induced conformational changes of its bacteriorhodopsin, directly converts absorbed light energy into a proton gradient and presumably also an electric potential difference across the membrane analogous to observations in other prokaryotic cells, mitochondria, and chloroplasts.

  15. [Purple glove syndrome - a case report].

    PubMed

    Warnecke, I C; Raute-Kreinsen, U; Schirmer, S; Kretschmer, F; Fansa, H

    2010-08-01

    The purple glove syndrome (PGS) is a soft tissue injury after peripheral intravenous phenytoin administration or oral overdosage. The incidence of PGS is described with 0-6%. Typical symptoms are purple discoloration, oedema, pain, and a decrease of range of motion. In severe cases PGS may lead to abscess, skin loss and compartment syndrome. The established treatment of PGS is immediate interruption of phenytoin injections, splinting, elevation, and close observation. In cases of severe complications (e. g., compartment syndrome), surgical intervention is necessary. The case of a 40-year-old female patient is reported who was transferred to our department 4 days after intravenous phenytoin administration and who underwent successful surgical revision. PMID:19847748

  16. Sun-beams, cucumbers, and purple bacteria : Historical milestones in early studies of photosynthesis revisited.

    PubMed

    Gest, H

    1988-10-01

    Discovery of the general outlines of plant and bacterial photosyntheses required the efforts of a large number of gifted scientists over the course of two centuries. The first to suggest that sunlight might affect plants in some way other than through conversion of light to heat was Stephen Hales, in 1725, and this notion was promptly satirized by Jonathan Swift in his description of the "cucumber project" inGulliver's Travels (1726). Considerably later, in 1772, Joseph Priestley reported the first experiments showing the production of "dephlogisticated air" (oxygen gas) by plants, and the interdependence of animal and plant life mediated by gases. Priestley and others, however, had difficulty repeating these experiments, mainly because they were unaware of the requirement for light in photosynthesis. The latter was clearly demonstrated in 1779 by Jan Ingen-Housz, who also determined that leaves were the primary sites of the photosynthetic production of oxygen by plants. When purple bacteria were first studied in the late 19th century by Theodor Engelmann, light-dependent O2 formation could not be detected. Contradictory observations in this connection were reported for a number of decades, but eventually the absence of O2 production in photosynthesis by purple bacteria was conclusively established. Attempts to explain why the bacteria do not evolve O2 led Cornelis van Niel to propose a "unified, comparative biochemical" explanation of photosynthetic processes that was widely accepted. This hypothesis, however, was abandoned soon after photophosphorylation by membranes from purple bacteria and plant chloroplasts was discovered in 1954. Unexpectedly, rapid progress in molecular biological and genetic studies of the membrane-bound reaction centers of purple bacteria indicate that current investigations are on the verge of revealing the detailed mechanisms by which energy conversion occurs in the reaction centers of all photosynthetic organisms. PMID:24425441

  17. Preparation and Antioxidant Activity of Purple Potato Wine

    PubMed Central

    Zhong-hua, Liu; Jie, Guo

    2015-01-01

    Purple potatoes were used as raw material to study the purple potato wine production process and antioxidant activity. This paper analyzed different fermentation time, fermentation temperature, yeast inoculum, initial pH, the initial sugar content on alcohol and anthocyanin contents of purple potato wine by single factor experiments and response surface methodology(RSM). The results showed that the optimum fermentation conditions of purple potato wine were as follows: fermentation temperature was 26oC, yeast inoculum was 0.15%, fermentation time was 7 d, initial pH was 3.0 and initial sugar content was 11 %. Under these conditions the alcohol and anthocyanin contents of purple potato wine could reach 10.55%/Vol and 6.42 μg/mL, respectively. The purple potato wine was purple, bright in colour, pleasant fragrance and pure taste. Prepared purple potato wine had the ability of reducing Fe3+ and scavenging superoxide anion radicals, which meant that purple potato wine had certain antioxidant activity. PMID:26998173

  18. An anaesthesiologist's encounter with purple glove syndrome

    PubMed Central

    Uma, B; Kochhar, Anjali

    2016-01-01

    Purple glove syndrome (PGS) is a devastating complication of intravenous (IV) phenytoin administration. Anaesthetic management during the amputation of the limb for such patients is very challenging due to limited clinical experience. A 65-year-old woman developed PGS of left upper extremity after IV administration of phenytoin following generalised tonic-clonic seizures. The condition progressed rapidly leading to gangrene of left hand extending to the mid arm. Amputation was carried out under general anaesthesia with a supraglottic airway device. We discuss the prevention and alternate managements in PGS, which is a rare clinical entity with limited data in the literature. PMID:27053784

  19. An anaesthesiologist's encounter with purple glove syndrome.

    PubMed

    Uma, B; Kochhar, Anjali

    2016-03-01

    Purple glove syndrome (PGS) is a devastating complication of intravenous (IV) phenytoin administration. Anaesthetic management during the amputation of the limb for such patients is very challenging due to limited clinical experience. A 65-year-old woman developed PGS of left upper extremity after IV administration of phenytoin following generalised tonic-clonic seizures. The condition progressed rapidly leading to gangrene of left hand extending to the mid arm. Amputation was carried out under general anaesthesia with a supraglottic airway device. We discuss the prevention and alternate managements in PGS, which is a rare clinical entity with limited data in the literature. PMID:27053784

  20. 50 CFR 21.53 - Control order for purple swamphens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... purple swamphens (Porphyrio porphyrio) or their nests or eggs at any time when they find them anywhere in... their nests or eggs if doing so is contrary to any State, territorial, tribal, or local laws or regulations. (2) You may not remove or destroy purple swamphens or their nests or eggs if doing so...

  1. 50 CFR 21.53 - Control order for purple swamphens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... purple swamphens (Porphyrio porphyrio) or their nests or eggs at any time when they find them anywhere in... their nests or eggs if doing so is contrary to any State, territorial, tribal, or local laws or regulations. (2) You may not remove or destroy purple swamphens or their nests or eggs if doing so...

  2. 50 CFR 21.53 - Control order for purple swamphens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... purple swamphens (Porphyrio porphyrio) or their nests or eggs at any time when they find them anywhere in... their nests or eggs if doing so is contrary to any State, territorial, tribal, or local laws or regulations. (2) You may not remove or destroy purple swamphens or their nests or eggs if doing so...

  3. The rotational diffusion of the acetylcholine receptor in Torpeda marmorata membrane fragments studied with a spin-labelled alpha-toxin: importance of the 43 000 protein(s).

    PubMed Central

    Rousselet, A; Cartaud, J; Devaux, P F; Changeux, J P

    1982-01-01

    The rotational diffusion of the acetylcholine (ACh) receptor in subsynaptic membrane fragments from Torpedo marmorata electric organ was investigated with a spin-labelled alpha-bungarotoxin. A toxin with two spin labels was first synthesized; the conventional electron spin resonance spectrum (e.s.r.) of this toxin bound to the receptor indicated: (1) a complete immobilization of the probes; and (2) a strong spin-spin interaction that was not, or barely, seen in solution. The modification of the degree of spin-spin interaction is taken as an indication of a toxin conformational change accompanying its binding to the ACh-receptor. To avoid spin-spin interaction a single-labelled toxin was made and used to follow the rotational diffusion of the receptor by saturation transfer e.s.r. (ST-e.s.r.). With native membranes a high immobilization of the ACh-receptor was noticed. Reduction of the membranes by dithiothreitol had little effect on this motion. Only extraction of the 43 000 protein(s) by pH 11 treatment was able to enhance the rotational diffusion of the ACh-receptor protein (rotational correlation time by ST-e.s.r. in the 0.5 - 1 X 10(-4) s range) and to allow its lateral diffusion in the plane of the membrane fragments (observed by electron microscopy after freeze-etching or negative staining). Images Fig. 3. Fig. 4. PMID:6329680

  4. Purple non-sulfur photosynthetic bacteria monitor environmental stresses.

    PubMed

    Kis, Mariann; Sipka, Gábor; Asztalos, Emese; Rázga, Zsolt; Maróti, Péter

    2015-10-01

    Heavy metal ion pollution and oxygen deficiency are major environmental risks for microorganisms in aqueous habitat. The potential of purple non-sulfur photosynthetic bacteria for biomonitoring and bioremediation was assessed by investigating the photosynthetic capacity in heavy metal contaminated environments. Cultures of bacterial strains Rhodobacter sphaeroides, Rhodospirillum rubrum and Rubrivivax gelatinosus were treated with heavy metal ions in micromolar (Hg(2+)), submillimolar (Cr(6+)) and millimolar (Pb(2+)) concentration ranges. Functional assays (flash-induced absorption changes and bacteriochlorophyll fluorescence induction) and electron micrographs were taken to specify the harmful effects of pollution and to correlate to morphological changes of the membrane. The bacterial strains and functional tests showed differentiated responses to environmental stresses, revealing that diverse mechanisms of tolerance and/or resistance are involved. The microorganisms were vulnerable to the prompt effect of Pb(2+), showed weak tolerance to Hg(2+) and proved to be tolerant to Cr(6+). The reaction center controlled electron transfer in Rvx. gelatinosus demonstrated the highest degree of resistance against heavy metal exposure. PMID:26232748

  5. Photooxidation Tolerance Characters of a New Purple Pepper

    PubMed Central

    Ou, Li-jun; Zhang, Zhu-qing; Dai, Xiong-ze; Zou, Xue-xiao

    2013-01-01

    Huai Zi (HZ) is a new purple mutant of green pepper (PI 631133) that is obtained from the United States Department of Agriculture. The net photosynthetic rate (PN), chlorophyll fluorescence parameters, antioxidant substances, antioxidant enzymes, photosystem 1 (PS1) and PS2 activities were studied through methyl viologen (MV) treatment. The results showed that the PN, actual photochemical efficiency of PS2 (ΦPS2), photochemical quenching coefficient (qP), PS1 and PS2 activities in HZ were lower than those in green pepper. HZ had a stronger ability to eliminate reactive oxygen species(O2•−) and accumulated less malondialdehyde (MDA) (a membrane lipid peroxidation product) than did green pepper, and had a higher content of antioxidants and antioxidant enzyme activity. This suggests that the lower light energy absorption and higher thermal dissipation and antioxidant activity of HZ contributed to a more stable PS2 photosynthetic capacity, which resulted in photooxidation tolerance. Hence, our study strongly suggests that pepper hybrids can achieve a modest ratio of chlorophyll and anthocyanin content, high PN and resistance to photooxidation, improving yield and resistance to adverse environments. PMID:23704924

  6. Incoming editorial: bigger, purple, pragmatic, and parsimony.

    PubMed

    Hilsenroth, Mark J

    2011-03-01

    It is with great excitement and enthusiasm that I write to you regarding several updates, new initiatives and changes with our journal. As you may have already noticed, this includes the change to a larger format, and a return to the color purple that helped define this journal from the early 1980s through the turn of the century, as well as to the original title "Psychotherapy." The change in format will allow us to benefit from the standard American Psychological Association (APA) journal design and layout, leading to more efficient processing and arrangement within their electronic journal system. I have found this first year as the Incoming Editor of Psychotherapy to be as challenging, rewarding, and intellectually stimulating as I imagined it would be, and I remain quite excited and enthusiastic about the work ahead. PMID:21401267

  7. Major anthocyanins from purple asparagus (Asparagus officinalis).

    PubMed

    Sakaguchi, Yumi; Ozaki, Yukio; Miyajima, Ikuo; Yamaguchi, Masaatsu; Fukui, Yuko; Iwasa, Keiko; Motoki, Satoru; Suzuki, Takashi; Okubo, Hiroshi

    2008-05-01

    Two major anthocyanins (A1 and A2) were isolated from peels of the spears of Asparagus officinalis cv. Purple Passion. They were purified by column, paper and high-performance liquid chromatographic separations, and their structures were elucidated by high-resolution Fourier transform ion cyclotron resonance mass spectrometry (HR-FT-ICR MS), 1H, 13C and two-dimensional NMR spectroscopic analyses and either acid or alkaline hydrolysis, respectively. A1 was identified as cyanidin 3-[3''-(O-beta-d-glucopyranosyl)-6''-(O-alpha-l-rhamnopyranosyl)-O-beta-d-glucopyranoside], whereas A2 was cyanidin 3-rutinoside, which is widely distributed in higher plants. Oxygen radical absorbance capacity (ORAC) assays proved their high antioxidant activities. PMID:18406435

  8. Antioxidant properties of various solvent extracts from purple basil.

    PubMed

    Yeşiloğlu, Yeşim; Sit, Latifşah

    2012-09-01

    Water, ethanol and acetone extracts from leaves and flowers of purple basil, one of the most popular spices consumed in the Thrace region of Turkey, were tested in vitro for their ability to inhibit peroxidation of lipids, to scavenge DPPH, hydrogen peroxide, superoxide anion, to reduce Fe(III) to Fe(II) and to chelate Fe(II) ions. The results showed that purple basil contained naturally occurring antioxidant components and possessed antioxidant activity which may be attributed to its lipid peroxidation inhibitory, radical scavenging and metal chelating activities. It was concluded that purple basil might be a potential source of antioxidants. PMID:22613128

  9. Antioxidant properties of various solvent extracts from purple basil

    NASA Astrophysics Data System (ADS)

    Yeşiloğlu, Yeşim; Şit, Latifşah

    2012-09-01

    Water, ethanol and acetone extracts from leaves and flowers of purple basil, one of the most popular spices consumed in the Thrace region of Turkey, were tested in vitro for their ability to inhibit peroxidation of lipids, to scavenge DPPH, hydrogen peroxide, superoxide anion, to reduce Fe(III) to Fe(II) and to chelate Fe(II) ions. The results showed that purple basil contained naturally occurring antioxidant components and possessed antioxidant activity which may be attributed to its lipid peroxidation inhibitory, radical scavenging and metal chelating activities. It was concluded that purple basil might be a potential source of antioxidants.

  10. New acylated anthocyanins from purple yam and their antioxidant activity.

    PubMed

    Moriya, Chiemi; Hosoya, Takahiro; Agawa, Sayuri; Sugiyama, Yasumasa; Kozone, Ikuko; Shin-Ya, Kazuo; Terahara, Norihiko; Kumazawa, Shigenori

    2015-01-01

    Purple yam (Dioscorea alata L.), which is widely distributed in tropical and subtropical regions, is characterized by its color and viscosity. Previous studies have shown that purple yams contain a variety of acylated anthocyanins that exhibit higher levels of antioxidant activity than the corresponding nonacylated compounds. In this study, the pigments found in purple yams from the Philippines (D. alata) were isolated and evaluated in terms of antioxidant activity. Four new acylated anthocyanins, alanins (1-4) were isolated from the MeOH extracts of purple yam, which were subsequently determined to be cyanidin (1, 2, and 4) and peonidin (3) type compounds, along with four known anthocyanins (5-8). The structures of 1-4 were determined by spectroscopic methods, including NMR and MS analyses. The antioxidant activities of anthocyanins 1-8 were investigated using oxygen radical absorbing capacity and ferric reducing antioxidant power assays. PMID:25848974

  11. View of Flume Tunnel #3 through Purple Mountain, showing flume ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Flume Tunnel #3 through Purple Mountain, showing flume entering into the tunnel. Looking south - Childs-Irving Hydroelectric Project, Childs System, Flume Tunnel No. 3, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  12. Structures of β-Amyloid Peptide 1–40, 1–42, and 1–55 -the 672–726 fragment of APP- in a membrane environment with implications for interactions with γ-secretase

    PubMed Central

    Miyashita, Naoyuki; Straub, John E.; Thirumalai, D.

    2009-01-01

    Aggregation Amyloid β (Aβ) peptide has been linked to the neurodegenerative Alzheimer’s Disease and implicated in other amyloid diseases including cerebral amyloid angiopathy. Aβ peptide is generated by cleavage of the amyloid precursor protein (APP) by transmembrane proteases. It is crucial to determine the structures of β-amyloid peptides in a membrane to provide a molecular basis for the cleavage mechanism. We report the structures of amyloid β peptide (Aβ1–40 and Aβ1–42) as well as the 672–726 fragment of APP (referred to as Aβ1–55) in a membrane environment determined by replica-exchange molecular dynamics simulation. Aβ1–40 is found to have two helical domains A (13–22) and B(30–35) and a type I β turn at 23–27. The peptide is localized at the interface between membrane and solvent. Substantial fluctuations in domain A are observed. The dominant simulated tertiary structure of Aβ1–40 is observed to be similar to the simulated Aβ1–42 structure. However, there are differences observed in the overall conformational ensemble as characterized by the two-dimensional free energy surfaces. The fragment of APP (Aβ1–55) is observed to have a long transmembrane helix. The position of the transmembrane region and ensemble of membrane structures are elucidated. The conformational transition between the transmembrane Aβ1–55 structure, prior to cleavage, and the Aβ1–40 structure, following cleavage, is proposed. PMID:19995075

  13. Identification, isolation, and sequence of the reaction center protein genes of the photosynthetic purple bacterium Rhodopseudomonas capsulata

    SciTech Connect

    Hearst, J.E.

    1984-07-01

    Reaction centers in photosynthetic membranes are the centers to which electronic excitation due to light absorption is transferred. This excitation brings about a charge separation between a bacteriochlorophyll molecule and two quinone molecules which ultimately leads to the formation of a hydroquinone. The reduced hydroquinone is then utilized to produce a proton gradient across the membrane and ultimately to produce ATP. We have focused our interest on the structure of the reaction center in the photosynthetic purple bacterium, Rhodopseudomonas capsulata, with the intention of establishing a detailed understanding of these first chemical steps in the natural fixation of sunlight. The methods used to identify and isolate the genes for the three reaction center subunits, L, M, and H, in Rps. capsulata are outlined. These genes have then been sequenced, and the sequences analyzed in detail for their similarity with sequences of comparable proteins from more advanced photosynthetic bacteria such as Anabena, from algae such as Euglena and Chlamydomonas, and from higher plants such as amaranthus, soybean, tobacco and spinach. Homology was found which has been tentatively interpreted to be in the region of quinone binding in all of these reaction centers. There is growing optimism that there will be substantial structural similarity between the reaction centers of the purple bacteria and those of photosystem II in higher plants. This conclusion is important because the x-ray crystal structures of several of the purple bacteria reaction center complexes are presently being worked on and will ultimately be solved.

  14. 1H- and 2H-NMR studies of a fragment of PMP1, a regulatory subunit associated with the yeast plasma membrane H(+)-ATPase. Conformational properties and lipid-peptide interactions.

    PubMed

    Beswick, V; Roux, M; Navarre, C; Coïc, Y M; Huynh-Dinh, T; Goffeau, A; Sanson, A; Neumann, J M

    1998-01-01

    PMP1 is a 38-residue polypeptide associated with the yeast plasma membrane H(+)-ATPase, found to regulate the enzyme activity. To investigate the molecular basis of the PMP1 biological function, the conformational properties of a synthetic PMP1 fragment, A18-F38, comprising the predicted C-terminal cytoplasmic domain and a part of the transmembrane anchor have been studied by 1H- and 2H-NMR spectroscopies. High resolution 1H-NMR experiments showed that, in deuterated DPC micelles, the A18-G34 segment adopts a well defined helix conformation. Our data suggest that the whole PMP1 molecule forms a unique helix whose axis might be slightly tilted with respect to the bilayer normal. Protonated DPC, DMPC and DMPS were incorporated in deuterated micelles containing the PMP1 fragment for studying lipid-peptide interactions. Unusually strong and selective intermolecular NOEs between lipid chain and peptide side chain protons, especially those of the unique Trp residue, were observed. Solid state 2H-NMR experiments performed on pure deuterated POPC and mixed deuterated POPC:POPS (5:1) bilayers revealed that the PMP1 fragment specifically interacts with negatively charged PS lipids. PMID:9782385

  15. Magma Fragmentation

    NASA Astrophysics Data System (ADS)

    Gonnermann, Helge M.

    2015-05-01

    Magma fragmentation is the breakup of a continuous volume of molten rock into discrete pieces, called pyroclasts. Because magma contains bubbles of compressible magmatic volatiles, decompression of low-viscosity magma leads to rapid expansion. The magma is torn into fragments, as it is stretched into hydrodynamically unstable sheets and filaments. If the magma is highly viscous, resistance to bubble growth will instead lead to excess gas pressure and the magma will deform viscoelastically by fracturing like a glassy solid, resulting in the formation of a violently expanding gas-pyroclast mixture. In either case, fragmentation represents the conversion of potential energy into the surface energy of the newly created fragments and the kinetic energy of the expanding gas-pyroclast mixture. If magma comes into contact with external water, the conversion of thermal energy will vaporize water and quench magma at the melt-water interface, thus creating dynamic stresses that cause fragmentation and the release of kinetic energy. Lastly, shear deformation of highly viscous magma may cause brittle fractures and release seismic energy.

  16. High Efficacy but Low Potency of δ-Opioid Receptor-G Protein Coupling in Brij-58-Treated, Low-Density Plasma Membrane Fragments

    PubMed Central

    Roubalova, Lenka; Vosahlikova, Miroslava; Brejchova, Jana; Sykora, Jan; Rudajev, Vladimir; Svoboda, Petr

    2015-01-01

    Principal Findings HEK293 cells stably expressing PTX-insensitive δ-opioid receptor-Gi1α (C351I) fusion protein were homogenized, treated with low concentrations of non-ionic detergent Brij-58 at 0°C and fractionated by flotation in sucrose density gradient. In optimum range of detergent concentrations (0.025–0.05% w/v), Brij-58-treated, low-density membranes exhibited 2-3-fold higher efficacy of DADLE-stimulated, high-affinity [32P]GTPase and [35S]GTPγS binding than membranes of the same density prepared in the absence of detergent. The potency of agonist DADLE response was significantly decreased. At high detergent concentrations (>0.1%), the functional coupling between δ-opioid receptors and G proteins was completely diminished. The same detergent effects were measured in plasma membranes isolated from PTX-treated cells. Therefore, the effect of Brij-58 on δ-opioid receptor-G protein coupling was not restricted to the covalently bound Gi1α within δ-opioid receptor-Gi1α fusion protein, but it was also valid for PTX-sensitive G proteins of Gi/Go family endogenously expressed in HEK293 cells. Characterization of the direct effect of Brij-58 on the hydrophobic interior of isolated plasma membranes by steady-state anisotropy of diphenylhexatriene (DPH) fluorescence indicated a marked increase of membrane fluidity. The time-resolved analysis of decay of DPH fluorescence by the “wobble in cone” model of DPH motion in the membrane indicated that the exposure to the increasing concentrations of Brij-58 led to a decreased order and higher motional freedom of the dye. Summary Limited perturbation of plasma membrane integrity by low concentrations of non-ionic detergent Brij-58 results in alteration of δ-OR-G protein coupling. Maximum G protein-response to agonist stimulation (efficacy) is increased; affinity of response (potency) is decreased. The total degradation plasma membrane structure at high detergent concentrations results in diminution of

  17. Report on New Capabilities for the Purple Development Environment

    SciTech Connect

    Futral, W S; Chambreau, C M; Gyllenhaal, J C; Wolfe, M E

    2006-12-12

    As part of the deliverables for the Development Environment for Purple, additional capabilities to improve the tools offerings and to address unique Purple system requirements, such as increased processor count, were expected. This report details some of the new capabilities that have been incorporated into the development environment tools for Purple. The shift on Purple to 64-bit applications (from 32-bit on White) initially broke many debugging and memory tools. Most tools were updated to support 64 bit well before Purple was delivered to LLNL, but the company that provided the popular heavy-weight 32-bit AIX memory tool, ZeroFault, was reluctant to port to 64 bit due to perceived lack of market. LLNL tried offering financial incentives to the ZeroFault developers, which were turned down, but eventually they did give vague promises to try to port to AIX 64-bit mode when they got time. The ZeroFault developers have been making intermittent and very slow progress over the last two plus years, but despite getting close, have not released a version of ZeroFault that yet meets our needs for 64-bit applications. However, given the critical need for memory tools and the uncertainty of ZeroFault development, other memory tool options were actively pursued and delivered.

  18. Forest Fragmentation

    EPA Science Inventory

    This indicator describes forest fragmentation in the contiguous United States circa 2001. This information provides a broad, recent picture of the spatial pattern of the nation’s forests and the extent to which they are being broken into smaller patches and pierced or interspe...

  19. View of Sally May/Purple Mountain Siphon Intake. Looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Sally May/Purple Mountain Siphon Intake. Looking southeast - Childs-Irving Hydroelectric Project, Childs System, Sally May-Purple Mountain Siphon Intake, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  20. The carboxyl modifier 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide (EDC) inhibits half of the high-affinity Mn-binding site in photosystem II membrane fragments

    SciTech Connect

    Preston, C.; Seibert, M. )

    1991-10-08

    The diphenylcarbazide (DPC)/Mn{sup 2+} assay was used to assess the amount of the high-affinity Mn-binding site in manganese-depleted photosystem II (PS II) membrane fragments from spinach and Scenedesmus obliquus. The assay mechanism at high DPC concentration was shown to involve noncompetitive inhibition of only half of the control level of DPC donation to PS II by micromolar concentrations of Mn at pH 6.5. At low DPC concentration both DPC and Mn{sup 2+} donate to PS II additively. Treatment with the carboxyl amino acid modifier 1-ethyl-3-(3(dimethylamino) propyl) carbodiimide (EDC) inhibited half of the high affinity Mn-binding site in spinach and Scenedesmus WT PS II membranes and all of the available site in Scenedesmus LF-1 mutant PS II membranes. A similar EDC concentration dependence was observed in all cases. This protection was specific for Mn{sup 2+}; six other divalent cations were ineffective. The authors conclude that EDC modifies that half of the high-affinity Mn-binding site that is insensitive to the histidine modifier diethyl pyrocarbonate (DEPC) and directly affects ligands that bind Mn. The effects of EDC and DEPC that influence the high-affinity site are mutually exclusive and are specific to the lumenal side of the PS II membrane. They suggest that carboxyl residues on reaction center proteins are associated with half of the high-affinity Mn-binding site in PS II and are involved along with histidine residues in binding Mn functional in the O{sub 2}-evolving process.

  1. Purple urine bag syndrome in an elderly patient from Colombia.

    PubMed

    Mondragón-Cardona, Alvaro; Jiménez-Canizales, Carlos Eduardo; Alzate-Carvajal, Verónica; Bastidas-Rivera, Fabricio; Sepúlveda-Arias, Juan Carlos

    2015-07-01

    A 71-year-old woman in a nursing home, with indwelling urinary catheter, bedridden, presented with a purple urine collector bag. The purple urine bag syndrome is a rare condition associated with the metabolism of tryptophan by overgrowth of intestinal bacteria. The purple color is formed by a combination of indigo and indirubin produced as a result of phosphatase and sulfatase enzymatic activity of bacteria on indoxyl sulfate, under alkaline pH of the urine. We present the second case of this syndrome reported in Colombia detailing the management of this rare syndrome associated with urinary tract infection. Several conditions should be considered in the differential diagnose of diseases that cause discoloration of the urine. PMID:26230133

  2. Crystal Structure of a Soluble Fragment of the Membrane Fusion Protein HlyD in a Type I Secretion System of Gram-Negative Bacteria.

    PubMed

    Kim, Jin-Sik; Song, Saemee; Lee, Minho; Lee, Seunghwa; Lee, Kangseok; Ha, Nam-Chul

    2016-03-01

    The protein toxin HlyA of Escherichia coli is exported without a periplasmic intermediate by the type I secretion system (T1SS). The T1SS is composed of an inner membrane ABC transporter HlyB, an outer-membrane channel protein TolC, and a membrane fusion protein HlyD. However, the assembly of the T1SS remains to be elucidated. In this study, we determine the crystal structure of a part of the C-terminal periplasmic domain of HlyD. The long α-helical domain consisting of three α helices and a lipoyl domain was identified in the crystal structure. Based on the HlyD structure, we modeled the hexameric assembly of HlyD with a long α-helical barrel, which formed a complex with TolC in an intermeshing cogwheel-to-cogwheel manner, as observed in tripartite RND-type drug efflux pumps. These observations provide a structural blueprint for understanding the type I secretion system in pathogenic Gram-negative bacteria. PMID:26833388

  3. [Purple urine bag syndrome in two institutionalised patients].

    PubMed

    Iglesias Barreira, Rebeca; Albiñana Pérez, M Sandra; Rodríguez Penín, Isaura; Bilbao Salcedo, José

    2013-01-01

    Purple urine bag syndrome (PUBS) is an uncommon but particularly striking phenomenon characterised by a chemical reaction involving the urine, plastic and certain enzymes from some sulphatase- and phosphatase-producing bacteria, including Proteus mirabilis, Escherichia coli and Morganella morganii, amongst others. Following this reaction, the catheter and the bag may be stained red, blue or purple. This phenomenon tends to occur in patients with multiple pathology and with urinary catheters, as part of a urinary tract infection. We describe two clinical cases of PUBS in institutionalised patients with permanent urinary catheters. PMID:23199817

  4. Dye-sensitized solar cells based on purple corn sensitizers

    NASA Astrophysics Data System (ADS)

    Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

    2016-09-01

    Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

  5. Warfarin and phenytoin drug interaction with possible purple glove syndrome.

    PubMed

    Hunter, Carolyn S; Phan, Stephanie V

    2016-01-01

    Though the impact of phenytoin on warfarin has been reported to potentiate the anticoagulant effect or interact in a biphasic manner, the effect of phenytoin on warfarin appears to be unpredictable and dependent upon multiple factors. Additionally, purple glove syndrome has rarely been reported secondary to therapeutic doses of oral phenytoin. We report on the case of a patient who experienced international normalized ratio (INR) fluctuations upon initiation of warfarin and phenytoin concurrently and who subsequently required discontinuation of therapeutic-dose phenytoin secondary to possible purple glove syndrome. PMID:27440955

  6. Cholesterol-dependent partitioning of PtdIns(4,5)P2 into membrane domains by the N-terminal fragment of NAP-22 (neuronal axonal myristoylated membrane protein of 22 kDa).

    PubMed Central

    Epand, Richard M; Vuong, Phan; Yip, Christopher M; Maekawa, Shohei; Epand, Raquel F

    2004-01-01

    A myristoylated peptide corresponding to the N-terminus of NAP-22 (neuronal axonal myristoylated membrane protein of 22 kDa) causes the quenching of the fluorescence of BODIPY-TMR-labelled PtdIns(4,5) P2 in bilayers of 1-palmitoyl-2-oleoyl phosphatidylcholine containing 40 mol% cholesterol and 0.1 mol% BODIPY-PtdIns(4,5)2. Both fluorescence spectroscopy and total internal reflectance fluorescence microscopy revealed the cholesterol-dependent nature of PtdIns(4,5) P2-enriched membrane-domain formation. PMID:14989697

  7. Halosulfuron reduced purple netsedge (Cyperus rotundus) tuber production and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weeds persist and cause economic losses in agricultural systems because they exploit an underutilized portion of that system. Reducing the impact of weeds on agroecosystems begins with minimizing the number of propagules (e.g, seeds and tubers) that are produced and returned to the soil. Purple nu...

  8. Halosulfuron reduced purple nutsedge (Cyperus rotundus) tuber production and viability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weeds persist and cause economic losses in agricultural systems because they exploit an underutilized portion of that system. Reducing the impact of weeds on agroecosystems begins with minimizing the number of propagules (e.g, seeds and tubers) that are produced and returned to the soil. Purple nu...

  9. Computer-Supported Study Strategies for Purple People.

    ERIC Educational Resources Information Center

    Tenny, John L.

    1992-01-01

    Describes how the computer can support the study process of students variously described as "multivariate, nonlinear thinkers,""dyslexic,""learning disabled," and "purple people." Describes features of a Macintosh program called "Inspiration" that enables easy test entry and manipulation in a graphic mode, placing emphasis on the considerable…

  10. [Adsorption and Desorption Characteristics of Endosulfan in Purple Soil].

    PubMed

    Zhao, Yan; Zheng, Guo-can; Zhu, Heng; Zhang, Jin-zhong; Zhu, Xiu-ying; Hu, Shu-chun; Wu, Ya-lin

    2015-09-01

    In order to reveal the residual process of endosulfan in purple soil and protect soil ecological environment, the adsorption and desorption characteristics of endosulfan in purple soil were investigated, and effects of temperature, adsorbent amount, and initial pH of adsorption solution on the adsorption capacity were also examined by static adsorption and desorption experiments. The results showed that the adsorption kinetic process could be well described by the second-order kinetic equation with the initial rate constants of α-, β-endosulfan as 0. 157 and 0. 115 mg.(g.min)-1, respectively. The adsorption thermodynamic process could be well described by the Langmuir isotherm with the maximum adsorption capacities of α-, β-endosulfan as 0. 257 mg . g -1 and 0. 155 mg . g -1, respectively. The adsorption process of endosulfan in purple soil may be an exothermic physicochemical process, and is dominated by physical adsorption. Under the experimental conditions examined in this study, the initial pH of adsorption solution had a relative great influence on the adsorption capacity, whereas the temperature and adsorbent amount had no significant influence. The desorption experiments found that the maximum desorption capacities of α-, β-endosulfan adsorbed in purple soil were 0. 029 mg . g -1 and 0. 017 mg . g -1 at 6 and 4 h, and accounted for 10. 5% and 16. 1% in the maximum adsorption capacities, respectively. PMID:26717711

  11. Alice Walker's Politics or the Politics of "The Color Purple."

    ERIC Educational Resources Information Center

    Hamilton, Cynthia

    1988-01-01

    Alice Walker's "The Color Purple" portrays Black women's oppression as the result of patriarchy, and proposes the acceptance of middle-class values--home ownership and entrepreneurship--as the solution to exploitation. She relies on stereotypes to characterize Black men and women, and depicts an ideology of submission. (BJV)

  12. Susceptibility of Different Potato Cultivars to Purple Top Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2002, Columbia Basin potato growers in Washington and Oregon began to experience serious outbreaks of potato purple top disease that have caused significant yield losses and reductions in tuber quality. It was determined that the beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma is...

  13. Formation of the light-harvesting complex I (B870) of anoxygenic phototrophic purple bacteria.

    PubMed

    Drews, G

    1996-09-01

    The light-harvesting (LH) complex I (B870) of anoxygenic photosynthetic purple bacteria is the oligomeric form of its subunit B820 consisting of the low-molecular-weight polypeptides alpha, beta, bacteriochlorophyll (BChl), and carotenoids in the stoichiometric ratio [alpha1 beta1 (BChl2) Crt1-2]n. LHI surrounds the photochemical reaction center (RC). The major absorption band of the LHI complex is species-specific and is found at 870-890 nm; those of the subunit and the monomeric BChl a (dissolved in methanol) absorb at 820 and 770 nm, respectively. The isolated LHI complex can be reversibly dissociated to the B820 subunit or to the polypeptides and pigments by addition of detergents. Reconstitution of the B820 or the functional B870 complex is still possible after partial truncation of the N- or C-terminal regions of the alpha- or beta-polypeptide or of the beta-polypeptide only. The minimal structural requirements for reconstitution of a spectrally wild-type form after truncation of the polypeptides and/or modifications of the BChl molecule are described. The insertion of the LHIalpha- and LHIbeta-polypeptides into the membrane and the in vivo assembly of LHI, studied in a cell-free system and in whole cells of Rhodobacter capsulatus, depend on the primary structures of both polypeptides, BChl, the chaperones DnaK and GroEL, membrane-bound proteins, and energized membranes. Exchanges, deletions, or insertions of amino acyl residues, especially in the conserved region of the N-terminus of the LHIalpha-polypeptide, prevent or reduce the efficiency and stability of the LHI assembly. Therefore, reconstitution of LHI in a detergent micelle does not exactly reproduce the formation of the LHI complex in the photosynthetic membrane in vivo. The N-terminal domains play a crucial role in the formation of the oligomeric protein scaffold and of the pigment array. Facultatively phototrophic bacteria such as Rhodospirillum (Rsp.) rubrum or Rhodobacter (Rba.) capsulatus can

  14. Membrane solubilization by the non-ionic detergent triton X-100. A comparative study including model and cell membranes.

    PubMed

    Macarulla, J M; Alonso, A; Arrondo, J L; González-Mañas, J M; Goñi, F M; Gurtubay, J I; Prado, A; Urbaneja, M A

    1989-01-01

    The solubilizing effects of the non-ionic detergent Triton X-100 have been examined on three membranous systems, namely rabbit sarcoplasmic reticulum, Halobacterium purple membrane and gramicidin A-phosphatidylcholine liposomes. The loss of membrane structure has been assessed through changes in suspension turbidity, while chemical analysis has revealed the differential solubilization of proteins and lipids. Solubilization data obtained on the above three systems are compared with previously published values concerning other membrane preparations. Also, solubilization of sarcoplasmic reticulum by Triton X-100 is monitored by Fourier-transform infrared spectroscopy and, similarly, purple membrane-surfactant interaction is studied using visible spectroscopy. The biochemical and spectroscopic data may be rationalized assuming a three-stage model of membrane-detergent interaction, incorporation of surfactant monomers into the membrane; disruption of the bilayer into mixed micelles, and separation of lipid and protein. PMID:2641811

  15. Perturbative fragmentation

    SciTech Connect

    Kopeliovich, B. Z.; Pirner, H.-J.; Potashnikova, I. K.; Schmidt, Ivan; Tarasov, A. V.

    2008-03-01

    The Berger model of perturbative fragmentation of quarks to pions is improved by providing an absolute normalization and keeping all terms in a (1-z) expansion, which makes the calculation valid at all values of fractional pion momentum z. We also replace the nonrelativistic wave function of a loosely bound pion by the more realistic procedure of projecting to the light-cone pion wave function, which in turn is taken from well known models. The full calculation does not confirm the (1-z){sup 2} behavior of the fragmentation function (FF) predicted in [E. L. Berger, Z. Phys. C 4, 289 (1980); Phys. Lett. 89B, 241 (1980] for z>0.5, and only works at very large z>0.95, where it is in reasonable agreement with phenomenological FFs. Otherwise, we observe quite a different z-dependence which grossly underestimates data at smaller z. The disagreement is reduced after the addition of pions from decays of light vector mesons, but still remains considerable. The process dependent higher twist terms are also calculated exactly and found to be important at large z and/or p{sub T}.

  16. Fragmentation of cancer cells

    NASA Astrophysics Data System (ADS)

    Vanapalli, Siva; Kamyabi, Nabiollah

    Tumor cells have to travel through blood capillaries to be able to metastasize and colonize in distant organs. Among the numerous cells that are shed by the primary tumor, very few survive in circulation. In vivo studies have shown that tumor cells can undergo breakup at microcapillary junctions affecting their survival. It is currently unclear what hydrodynamic and biomechanical factors contribute to fragmentation and moreover how different are the breakup dynamics of highly and weakly metastatic cells. In this study, we use microfluidics to investigate flow-induced breakup of prostate and breast cancer cells. We observe several different modes of breakup of cancer cells, which have striking similarities with breakup of viscous drops. We quantify the breakup time and find that highly metastatic cancer cells take longer to breakup than lowly metastatic cells suggesting that tumor cells may dynamically modify their deformability to avoid fragmentation. We also identify the role that cytoskeleton and membrane plays in the breakup process. Our study highlights the important role that tumor cell fragmentation plays in cancer metastasis. Cancer Prevention and Research Institute of Texas.

  17. Electroeluting DNA fragments.

    PubMed

    Zarzosa-Alvarez, Ana L; Sandoval-Cabrera, Antonio; Torres-Huerta, Ana L; Bermudez-Cruz, Rosa M

    2010-01-01

    Purified DNA fragments are used for different purposes in Molecular Biology and they can be prepared by several procedures. Most of them require a previous electrophoresis of the DNA fragments in order to separate the band of interest. Then, this band is excised out from an agarose or acrylamide gel and purified by using either: binding and elution from glass or silica particles, DEAE-cellulose membranes, "crush and soak method", electroelution or very often expensive commercial purification kits. Thus, selecting a method will depend mostly of what is available in the laboratory. The electroelution procedure allows one to purify very clean DNA to be used in a large number of applications (sequencing, radiolabeling, enzymatic restriction, enzymatic modification, cloning etc). This procedure consists in placing DNA band-containing agarose or acrylamide slices into sample wells of the electroeluter, then applying current will make the DNA fragment to leave the agarose and thus be trapped in a cushion salt to be recovered later by ethanol precipitation. PMID:20834225

  18. Native Mass Spectrometry Characterizes the Photosynthetic Reaction Center Complex from the Purple Bacterium Rhodobacter sphaeroides

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Harrington, Lucas B.; Lu, Yue; Prado, Mindy; Saer, Rafael; Rempel, Don; Blankenship, Robert E.; Gross, Michael L.

    2016-08-01

    Native mass spectrometry (MS) is an emerging approach to study protein complexes in their near-native states and to elucidate their stoichiometry and topology. Here, we report a native MS study of the membrane-embedded reaction center (RC) protein complex from the purple photosynthetic bacterium Rhodobacter sphaeroides. The membrane-embedded RC protein complex is stabilized by detergent micelles in aqueous solution, directly introduced into a mass spectrometer by nano-electrospray (nESI), and freed of detergents and dissociated in the gas phase by collisional activation. As the collision energy is increased, the chlorophyll pigments are gradually released from the RC complex, suggesting that native MS introduces a near-native structure that continues to bind pigments. Two bacteriochlorophyll a pigments remain tightly bound to the RC protein at the highest collision energy. The order of pigment release and their resistance to release by gas-phase activation indicates the strength of pigment interaction in the RC complex. This investigation sets the stage for future native MS studies of membrane-embedded photosynthetic pigment-protein and related complexes.

  19. Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 Variants per Genome Can Bind IgM via Its Fc Fragment Fcμ

    PubMed Central

    Jeppesen, Anine; Ditlev, Sisse Bolm; Soroka, Vladyslav; Stevenson, Liz; Turner, Louise; Dzikowski, Ron; Hviid, Lars

    2015-01-01

    The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) adhesive proteins expressed on the surfaces of infected erythrocytes (IEs) are of key importance in the pathogenesis of P. falciparum malaria. Several structurally and functionally defined PfEMP1 types have been associated with severe clinical manifestations, such as cerebral malaria in children and placental malaria in pregnant women. PfEMP1 that can bind the Fc part of IgM (Fcμ) characterizes one such type, although the functional significance of this IgM binding to PfEMP1 remains unclear. In this study, we report the identification and functional analysis of five IgM-binding PfEMP1 proteins encoded by P. falciparum NF54. In addition to the VAR2CSA-type PFL0030c protein, already known to bind Fcμ and to mediate chondroitin sulfate A (CSA)-specific adhesion of IEs in the placenta, we found four PfEMP1 proteins not previously known to bind IgM this way. Although they all contained Duffy binding-like ε (DBLε) domains similar to those in VAR2CSA-type PfEMP1, they did not mediate IE adhesion to CSA, and IgM binding did not shield IEs from phagocytosis of IgG-opsonized IEs. In this way, these new IgM-binding PfEMP1 proteins resemble the rosette-mediating and IgM-binding PfEMP1 HB3VAR06, but none of them mediated formation of rosettes. We could map the capacity for Fc-specific IgM binding to DBLε domains near the C terminus for three of the four PfEMP1 proteins tested. Our study provides new evidence regarding Fc-dependent binding of IgM to PfEMP1, which appears to be a common and multifunctional phenotype. PMID:26216422

  20. Development and dynamics of the photosynthetic apparatus in purple phototrophic bacteria.

    PubMed

    Niederman, Robert A

    2016-03-01

    The purple bacterium Rhodobacter sphaeroides provides a useful model system for studies of the assembly and dynamics of bacterial photosynthetic membranes. For the nascent developing membrane, proteomic analyses showed an ~2-fold enrichment in general membrane assembly factors, compared to chromatophores. When the protonophore carbonyl-cyanide m-chlorophenyl-hydrazone (CCCP) was added to an ICM inducing culture, an ~2-fold elevation in spectral counts vs. the control was seen for the SecA translocation ATPase, the preprotein translocase SecY, SecD and SecF insertion components, and chaperonins DnaJ and DnaK, which act early in the assembly process. It is suggested that these factors accumulated with their nascent polypeptides, as putative assembly intermediates in a functionally arrested state. Since in Synechocystis PCC 6803, a link has been established between Chl delivery involving the high-light HilD protein and the SecY/YidC-requiring cotranslational insertion of nascent polypeptides, such a connection between BChl biosynthesis and insertion and folding of nascent Rba. sphaeroides BChl binding proteins is likely to also occur. AFM imaging studies of the formation of the reaction center (RC)-light harvesting 1 (LH1) complex suggested a cooperative assembly mechanism in which, following the association between the RC template and the initial LH1 unit, addition of successive LH1 units to the RC drives the assembly process to completion. Alterations in membrane dynamics as the developing membrane becomes filled with LH2-rings were assessed by fluorescence induction/relaxation kinetics, which showed a slowing in RC electron transfer rate thought to mainly reflect alterations in donor side electron transfer. This was attributed to an increased distance for electron flow in cytochrome c2 between the RC and cytochrome bc1 complexes, as suggested in the current structural models. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic

  1. Chloroform-Methanol Residue of Coxiella burnetii Markedly Potentiated the Specific Immunoprotection Elicited by a Recombinant Protein Fragment rOmpB-4 Derived from Outer Membrane Protein B of Rickettsia rickettsii in C3H/HeN Mice

    PubMed Central

    Gong, Wenping; Wang, Pengcheng; Xiong, Xiaolu; Jiao, Jun; Yang, Xiaomei; Wen, Bohai

    2015-01-01

    The obligate intracellular bacteria, Rickettsia rickettsii and Coxiella burnetii, are the potential agents of bio-warfare/bio-terrorism. Here C3H/HeN mice were immunized with a recombinant protein fragment rOmp-4 derived from outer membrane protein B, a major protective antigen of R. rickettsii, combined with chloroform-methanol residue (CMR) extracted from phase I C. burnetii organisms, a safer Q fever vaccine. These immunized mice had significantly higher levels of IgG1 and IgG2a to rOmpB-4 and interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), two crucial cytokines in resisting intracellular bacterial infection, as well as significantly lower rickettsial loads and slighter pathological lesions in organs after challenge with R. rickettsii, compared with mice immunized with rOmpB-4 or CMR alone. Additionally, after challenge with C. burnetii, the coxiella loads in the organs of these mice were significantly lower than those of mice immunized with rOmpB-4 alone. Our results prove that CMR could markedly potentiate enhance the rOmpB-4-specific immunoprotection by promoting specific and non-specific immunoresponses and the immunization with the protective antigen of R. rickettsii combined with CMR of C. burnetii could confer effective protection against infection of R. rickettsii or C. burnetii. PMID:25909586

  2. Anticlastogenicity and Anticarcinogenicity of Purple Rice Extract in Rats.

    PubMed

    Punvittayagul, Charatda; Sankam, Paweena; Taya, Sirinya; Wongpoomchai, Rawiwan

    2016-01-01

    Oryza sativa L. var. indica cv. Kum Doi Saket is a pigmented rice variety grown in northern Thailand. Our previous study found that the methanol extract of purple rice seed had the highest level of antimutagenicity in a Salmonella mutation assay. The present study was designed to evaluate its in vivo anticlastogenic and anticarcinogenic potentials. The purple rice extract had no acute toxicity on rats. The oral administration of 1,000 mg/kg body weight (bw) of the extract for 28 days did not increase the number of micronucleated hepatocytes. Interestingly, it significantly reduced the amount of micronucleus formation in the liver of diethylnitrosamine (DEN)-treated rats. The inhibitory mechanism involved the induction of hepatic glutathione S-transferase (GST) activity. In addition, oral administration of 500 mg/kg bw extract for 10 weeks significantly decreased the number of hepatic GST placental form positive foci, but did not modulate the number of colonic aberrant crypt foci in DEN- and dimethylhydrazine-initiated rats. In conclusion, the methanol extract of purple rice seed showed no toxicity, clastogenicity, or carcinogenicity in laboratory rats. It did display chemopreventive activity against the early stages of rat hepatocarcinogenesis. PMID:27115481

  3. Interplay between excitation kinetics and reaction-center dynamics in purple bacteria

    NASA Astrophysics Data System (ADS)

    Caycedo-Soler, Felipe; Rodríguez, Ferney J.; Quiroga, Luis; Johnson, Neil F.

    2010-09-01

    Photosynthesis is arguably the fundamental process of life, since it enables energy from the Sun to enter the food chain on the Earth. It is a remarkable non-equilibrium process in which photons are converted to many-body excitations, which traverse a complex biomolecular membrane, where they are captured and fuel chemical reactions within a reaction center (RC) in order to produce nutrients. The precise nature of these dynamical processes—which lie at the interface between quantum and classical behavior and involve both noise and coordination—is still being explored. Here, we focus on a striking recent empirical finding concerning an illumination-driven transition in the biomolecular membrane architecture of the purple bacteria Rsp. photometricum. Using stochastic realizations to describe a hopping rate model for excitation transfer, we show numerically and analytically that this surprising shift in preferred architectures can be traced to the interplay between the excitation kinetics and the RC dynamics. The net effect is that the bacteria profit from efficient metabolism at low illumination intensities while using dissipation to avoid an oversupply of energy at high illumination intensities.

  4. A purple acid phosphatase plays a role in nodule formation and nitrogen fixation in Astragalus sinicus.

    PubMed

    Wang, Jianyun; Si, Zaiyong; Li, Fang; Xiong, Xiaobo; Lei, Lei; Xie, Fuli; Chen, Dasong; Li, Yixing; Li, Youguo

    2015-08-01

    The AsPPD1 gene from Astragalus sinicus encodes a purple acid phosphatase. To address the functions of AsPPD1 in legume-rhizobium symbiosis, its expression patterns, enzyme activity, subcellular localization, and phenotypes associated with its over-expression and RNA interference (RNAi) were investigated. The expression of AsPPD1 was up-regulated in roots and nodules after inoculation with rhizobia. Phosphate starvation reduced the levels of AsPPD1 transcripts in roots while increased those levels in nodules. We confirmed the acid phosphatase and phosphodiesterase activities of recombinant AsPPD1 purified from Pichia pastoris, and demonstrated its ability to hydrolyze ADP and ATP in vitro. Subcellular localization showed that AsPPD1 located on the plasma membranes in hairy roots and on the symbiosomes membranes in root nodules. Over-expression of AsPPD1 in hairy roots inhibited nodulation, while its silencing resulted in nodules early senescence and significantly decreased nitrogenase activity. Furthermore, HPLC measurement showed that AsPPD1 overexpression affects the ADP levels in the infected roots and nodules, AsPPD1 silencing affects the ratio of ATP/ADP and the energy charge in nodules, and quantitative observation demonstrated the changes of AsPPD1 transcripts level affected nodule primordia formation. Taken together, it is speculated that AsPPD1 contributes to symbiotic ADP levels and energy charge control, and this is required for effective nodule organogenesis and nitrogen fixation. PMID:26105827

  5. Low temperature treatment of domestic wastewater by purple phototrophic bacteria: Performance, activity, and community.

    PubMed

    Hülsen, Tim; Barry, Edward M; Lu, Yang; Puyol, Daniel; Batstone, Damien J

    2016-09-01

    Low wastewater temperatures affect microbial growth rates and microbial populations, as well as physical chemical characteristics of the wastewater. Wastewater treatment plant design needs to accommodate changing temperatures, and somewhat limited capacity is a key criticism of low strength anaerobic treatment such as Anaerobic Membrane Bioreactors (AnMBR). This study evaluates the applicability of an alternative platform utilizing purple phototrophic bacteria for low temperature domestic wastewater treatment. Two photo-anaerobic membrane bioreactors (PAnMBR) at ambient (22 °C) and low temperatures (10 °C) were compared to fully evaluate temperature response of critical processes. The results show good functionality at 10 °C in comparison with ambient operation. This enabled operation at 10 °C to discharge limits (TCOD < 100 mg L(-1); TN < 10 mg L(-1) and TP < 1 mg L(-1)) at a HRT < 1 d. While capacity of the system was not limited, microbial community showed a strong shift to a far narrower diversity, almost complete dominance by PPB, and of a single Rhodobacter spp. compared to a more diverse community in the ambient reactor. The outcomes of the current work enable applicability of PPB for domestic wastewater treatment to a broad range of regions. PMID:27235774

  6. Synthesis of High-Molecular-Weight Polyhydroxyalkanoates by Marine Photosynthetic Purple Bacteria

    PubMed Central

    Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Toyooka, Kiminori; Numata, Keiji

    2016-01-01

    Polyhydroxyalkanoate (PHA) is a biopolyester/bioplastic that is produced by a variety of microorganisms to store carbon and increase reducing redox potential. Photosynthetic bacteria convert carbon dioxide into organic compounds using light energy and are known to accumulate PHA. We analyzed PHAs synthesized by 3 purple sulfur bacteria and 9 purple non-sulfur bacteria strains. These 12 purple bacteria were cultured in nitrogen-limited medium containing acetate and/or sodium bicarbonate as carbon sources. PHA production in the purple sulfur bacteria was induced by nitrogen-limited conditions. Purple non-sulfur bacteria accumulated PHA even under normal growth conditions, and PHA production in 3 strains was enhanced by nitrogen-limited conditions. Gel permeation chromatography analysis revealed that 5 photosynthetic purple bacteria synthesized high-molecular-weight PHAs, which are useful for industrial applications. Quantitative reverse transcription polymerase chain reaction analysis revealed that mRNA levels of phaC and PhaZ genes were low under nitrogen-limited conditions, resulting in production of high-molecular-weight PHAs. We conclude that all 12 tested strains are able to synthesize PHA to some degree, and we identify 5 photosynthetic purple bacteria that accumulate high-molecular-weight PHA molecules. Furthermore, the photosynthetic purple bacteria synthesized PHA when they were cultured in seawater supplemented with acetate. The photosynthetic purple bacteria strains characterized in this study should be useful as host microorganisms for large-scale PHA production utilizing abundant marine resources and carbon dioxide. PMID:27513570

  7. Synthesis of High-Molecular-Weight Polyhydroxyalkanoates by Marine Photosynthetic Purple Bacteria.

    PubMed

    Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Toyooka, Kiminori; Numata, Keiji

    2016-01-01

    Polyhydroxyalkanoate (PHA) is a biopolyester/bioplastic that is produced by a variety of microorganisms to store carbon and increase reducing redox potential. Photosynthetic bacteria convert carbon dioxide into organic compounds using light energy and are known to accumulate PHA. We analyzed PHAs synthesized by 3 purple sulfur bacteria and 9 purple non-sulfur bacteria strains. These 12 purple bacteria were cultured in nitrogen-limited medium containing acetate and/or sodium bicarbonate as carbon sources. PHA production in the purple sulfur bacteria was induced by nitrogen-limited conditions. Purple non-sulfur bacteria accumulated PHA even under normal growth conditions, and PHA production in 3 strains was enhanced by nitrogen-limited conditions. Gel permeation chromatography analysis revealed that 5 photosynthetic purple bacteria synthesized high-molecular-weight PHAs, which are useful for industrial applications. Quantitative reverse transcription polymerase chain reaction analysis revealed that mRNA levels of phaC and PhaZ genes were low under nitrogen-limited conditions, resulting in production of high-molecular-weight PHAs. We conclude that all 12 tested strains are able to synthesize PHA to some degree, and we identify 5 photosynthetic purple bacteria that accumulate high-molecular-weight PHA molecules. Furthermore, the photosynthetic purple bacteria synthesized PHA when they were cultured in seawater supplemented with acetate. The photosynthetic purple bacteria strains characterized in this study should be useful as host microorganisms for large-scale PHA production utilizing abundant marine resources and carbon dioxide. PMID:27513570

  8. Effect of the Purple carbon black on the properties of NR/BR blend

    NASA Astrophysics Data System (ADS)

    Yanfang, Zhao; Dan, Liu; Shengbo, Lin; Binjian; Yinmei, Zhao; Shuangquan, Liao

    2014-08-01

    Purple black is light colored mineral filler mining in recent years in Hainan. The effect of the dosage of the purple carbon black and purple carbon black modificated by Si69 on the vulcanization characteristics, mechanical properties, thermal stability, the damping performance of NR/BR blend rubber were studied, and the blending adhesive tensile sections were analyzed by SEM. Research showed that, with the increasing dosage of the purple carbon black, vulcanization characteristics of NR/BR blend had a little change. Adding the purple carbon black into blending had a reinforcing effect. when the dosage of the purple carbon black was 20, the mechanical properties of blending adhesive was good; Coupling agent Si69 had a modification effect on the purple carbon black. With increasing dosage of Si69, performance of the rubber was improved initially and then decreased; when the mass fraction of Si69 was 8% of the dosage of the purple carbon black, rubber performance was optimal. Purple carbon black had no obvious effect on thermal stability of the rubber, but it improved the damping rubber temperature and damping factor.

  9. Gem-quality Turkish purple jade: Geological and mineralogical characteristics

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Başevirgen, Yasemin; Chamberlain, Steven C.

    2012-02-01

    In the Harmancık-Bursa region of the western Anatolia (Turkey), an extensive contact metamorphic aureole at the border between the Late Mesozoic coherent metaclastic rocks of blueschist facies and the Early Senozoic intrusive granodiorite stock hosts an interesting and unique gem material with a mineral assemblage consisting mainly of jadeite, quartz, orthoclase, epidote, chloritoid, and phlogopite as identified by X-ray diffraction spectroscopy and polarized-light microscopy. In addition, chemical analyses performed with X-ray fluorescence and inductive-coupled plasma-atomic emission spectroscopy show that the mass of the metamorphic aureole has a silica-rich, calc-alkaline chemical content. Therefore, some rock building elements (such as Al, Ca, Na, K, P, Sr, and B of which characterize an acidic-neutral rock formation) and trace elements (such as Fe, Cr, Mn, Be, Cu, Ga, La, Ni, Pb, and Zn) are remarkable high ratios. Pale purple-colored gem material of this composition appears to be unique to Turkey, also is only found in one narrow provenance in Turkey. Therefore, it is specially called "Turkish (and/or Anatolian) purple jade" on the worldwide gem market. Even though the mineral jadeite is the principal constituent, 40% by volume as determined with petrographic thin-section examination under a polarized-light microscope, the material cannot be considered pure jadeite. Specific gravity measurements of the jade using a hydrostatic balance confirm that it has a heterogeneous structure. The measured average specific gravity of 3.04, is significantly lower than the normal range for characterized jadeites of 3.24-3.43. Turkish purple jade samples were examined in detail using dispersive confocal micro-Raman spectroscopy (DCμRS) as well as other well-known analytical methods. The resulting strong micro-Raman bands that peaked at 1038, 984, 697, 571, 521, 464, 430, 372, 326, 307, 264, and 201 cm -1 are characteristics of the Turkish purple jade. The first most

  10. Menaquinone as pool quinone in a purple bacterium

    PubMed Central

    Schoepp-Cothenet, Barbara; Lieutaud, Clément; Baymann, Frauke; Verméglio, André; Friedrich, Thorsten; Kramer, David M.; Nitschke, Wolfgang

    2009-01-01

    Purple bacteria have thus far been considered to operate light-driven cyclic electron transfer chains containing ubiquinone (UQ) as liposoluble electron and proton carrier. We show that in the purple γ-proteobacterium Halorhodospira halophila, menaquinone-8 (MK-8) is the dominant quinone component and that it operates in the QB-site of the photosynthetic reaction center (RC). The redox potentials of the photooxidized pigment in the RC and of the Rieske center of the bc1 complex are significantly lower (Em = +270 mV and +110 mV, respectively) than those determined in other purple bacteria but resemble those determined for species containing MK as pool quinone. These results demonstrate that the photosynthetic cycle in H. halophila is based on MK and not on UQ. This finding together with the unusual organization of genes coding for the bc1 complex in H. halophila suggests a specific scenario for the evolutionary transition of bioenergetic chains from the low-potential menaquinones to higher-potential UQ in the proteobacterial phylum, most probably induced by rising levels of dioxygen 2.5 billion years ago. This transition appears to necessarily proceed through bioenergetic ambivalence of the respective organisms, that is, to work both on MK- and on UQ-pools. The establishment of the corresponding low- and high-potential chains was accompanied by duplication and redox optimization of the bc1 complex or at least of its crucial subunit oxidizing quinols from the pool, the Rieske protein. Evolutionary driving forces rationalizing the empirically observed redox tuning of the chain to the quinone pool are discussed. PMID:19429705

  11. Fire and nitrogen effects on Purple Threeawn (Aristida purpurea)abundance in northern mixed-grass prairie old fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple threeawn (Aristida purpurea Nutt. varieties) is a native grass capable of increasing on rangelands, forming near monocultures, and creating a stable state. Productive rangelands throughout the Great Plains and Intermountain West have experienced increases in purple threeawn abundance, reduci...

  12. Report on Challenges and Resolutions for the Purple Development Environment

    SciTech Connect

    Futral, W S; Gyllenhaal, J C; Wolfe, M E; Chambreau, C M

    2006-12-12

    Previous AIX development environment experience with ASC White and Early Delivery systems UV and UM was leveraged to provide a smooth and robust transition to the Purple development environment. Still, there were three major changes that initially caused serious problems for Purple users. The first was making 64-bit builds of executables the default instead of 32-bit. The second was requiring all executables to use large page memory. The third was the phase-out of the popular, but now defunct, third-party C++ compiler KCC, which required the migration of many codes to IBM's xlC C++ compiler. On Purple, the default build environment changed from 32-bit builds to 64-bit builds in order to enable executables to use the 4GB per processor (32GB per node) memory available, and in order for the MPI library to do collective optimizations that required the larger 64-bit address space. The 64-bit build environment was made default by setting the IBM environment variable OBJECT{_}MODE to 64 and wrapping third-party software (mainly the gnu compilers) in order to make them handle OBJECT{_}MODE properly. Because not all applications could port to 64-bit right away, (usually due to third-party constraints, such as python not supporting 64-bit AIX builds until very recently), 32-bit builds of the major common third-party libraries also had be supported. This combined 32/64 bit build support was accomplished fairly seamlessly using the AIX feature that allows both 32-bit and 64-bit versions of the code to appear in the same library file, and documentation with clear examples helped our library developers generate the required combined 32-bit and 64-bit libraries for Purple. In general, the port to 64-bit AIX executables went smoothly. The most common problem encountered with 64-bit was that many C codes didn't prototype malloc everywhere, via ''include '', which caused invalid pointers to be returned by unprototyped malloc calls. This was usually seen in old crusty C

  13. Challenges in plasma membrane phosphoproteomics

    PubMed Central

    Orsburn, Benjamin C; Stockwin, Luke H; Newton, Dianne L

    2011-01-01

    The response to extracellular stimuli often alters the phosphorylation state of plasma membrane-associated proteins. In this regard, generation of a comprehensive membrane phosphoproteome can significantly enhance signal transduction and drug mechanism studies. However, analysis of this subproteome is regarded as technically challenging, given the low abundance and insolubility of integral membrane proteins, combined with difficulties in isolating, ionizing and fragmenting phosphopeptides. In this article, we highlight recent advances in membrane and phosphoprotein enrichment techniques resulting in improved identification of these elusive peptides. We also describe the use of alternative fragmentation techniques, and assess their current and future value to the field of membrane phosphoproteomics. PMID:21819303

  14. Research on purple seed stain of soybean: germplasm screening and genetic resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean purple seed stain (PSS) causes seed decay and purple seed discoloration, resulting in overall poor seed quality and reduced market grade and value. It is a prevalent disease that also affects seed vigor and stand establishment. PSS is caused by the fungus Cercospora kikuchii and other Cercos...

  15. View of Sally May/Purple Mountain Siphon Intake house from the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Sally May/Purple Mountain Siphon Intake house from the south showing the flume existing. Looking north - Childs-Irving Hydroelectric Project, Childs System, Sally May-Purple Mountain Siphon Intake, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  16. View of Sally May/Purple Mountain Siphon. FS road #502 is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of Sally May/Purple Mountain Siphon. FS road #502 is in the bottom foreground. Looking west-southwest - Childs-Irving Hydroelectric Project, Childs System, Sally May-Purple Mountain Siphon, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  17. The purple cauliflower arises from activation of a MYB transcription factor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthocyanins are responsible for the color of many flowers, fruits, and vegetables. An interesting and unique Purple (Pr) gene mutation in cauliflower confers an abnormal pattern of anthocyanin accumulation, giving the striking mutant phenotype of intense purple color in curds and a few other tissue...

  18. The purple cauliflower arises from activation of a myb transcription factor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthocyanins are responsible for the color of many flowers, fruits, and vegetables. An interesting and unique Purple (Pr) gene mutation in cauliflower (Brassica oleracea var botrytis) confers an abnormal pattern of anthocyanin accumulation, giving the striking mutant phenotype of intense purple colo...

  19. Impact of the Columbia Basin potato purple top phytoplasma on potato tuber processing quality.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recently, the Columbia Basin potato purple top phytoplasma has been identified as the causal agent of the recent potato purple top disease outbreaks that occurred in the Columbia Basin of Washington and Oregon. It has also been determined that the beet leafhopper is the major vector of this plant pa...

  20. Bioavailability of Anthocyanins from Purple Carrot Juice: Effects of Acylation and Plant Matrix

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bioavailability of anthocyanins from juiced purple carrots was investigated through a human feeding study. Ten healthy adults consumed three doses of purple carrot juice, and bioavailability was assessed by appearance of anthocyanins in plasma for 8 hours after the dose. Doses were 50 mL, 150 mL, ...

  1. Screening a diverse soybean germplasm collection for reaction to purple seed stain caused by Cercospora kikuchii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple seed stain (PSS), caused by Cercospora kikuchii, is a prevalent soybean disease that causes latent seed infection, seed decay, purple seed discoloration, and overall quality deterioration. The objective of this research was to screen soybean accessions from the USDA germplasm collection for r...

  2. Anthocyanins and flavonols are responsible for purple color of Lablab purpureus (L.) sweet pods.

    PubMed

    Cui, Baolu; Hu, Zongli; Zhang, Yanjie; Hu, Jingtao; Yin, Wencheng; Feng, Ye; Xie, Qiaoli; Chen, Guoping

    2016-06-01

    Lablab pods, as dietary vegetable, have high nutritional values similar to most of edible legumes. Moreover, our studies confirmed that purple lablab pods contain the natural pigments of anthocyanins and flavonols. Compared to green pods, five kinds of anthocyanins (malvidin, delphinidin and petunidin derivatives) were found in purple pods by HPLC-ESI-MS/MS and the major contents were delphinidin derivatives. Besides, nine kinds of polyphenol derivatives (quercetin, myricetin, kaempferol and apigenin derivatives) were detected by UPLC-ESI-MS/MS and the major components were quercetin and myricetin derivatives. In order to discover their molecular mechanism, expression patterns of biosynthesis and regulatory gens of anthocyanins and flavonols were investigated. Experimental results showed that LpPAL, LpF3H, LpF3'H, LpDFR, LpANS and LpPAP1 expressions were significantly induced in purple pods compared to green ones. Meanwhile, transcripts of LpFLS were more abundant in purple pods than green or yellow ones, suggestind that co-pigments of anthocyanins and flavonols are accumulated in purple pods. Under continuously dark condition, no anthocyanin accumulation was detected in purple pods and transcripts of LpCHS, LpANS, LpFLS and LpPAP1 were remarkably repressed, indicating that anthocyanins and flavonols biosynthesis in purple pods was regulated in light-dependent manner. These results indicate that co-pigments of anthocyanins and flavonols contribute to purple pigmentations of pods. PMID:26995313

  3. Pressurized liquid extraction and quantification of anthocyanins in purple-fleshed sweetpotato genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analysis of anthocyanins responsible for the purple flesh color is important for breeding programs and development of value-added products. This study aimed to optimize the conditions for anthocyanin extraction from purple-fleshed sweet potatoes (PFSP) using pressurized-liquid extraction (PLE) metho...

  4. Membrane photobiophysics and photochemistry

    NASA Astrophysics Data System (ADS)

    Ti Tien, H.

    Life, as we know it, depends on solar energy, in particular in the visible range of the solar spectrum. However, visible light alone is useless to the living organism unless a means is available for its capture, transformation, and utilization. Nature, through its long evolution, has perfected a process known as photosynthesis by which visible light is transduced into electrical/ chemical energy. However, the heart of Nature's energy transducer is the thylakoid membrane whose molecular organization was not known until early in the 1960s. Then it was established that the bilayer lipid membrane was central to the design of the thylakoid membrane. To explain the light-driven reactions from water oxidation to carbon dioxide reduction, the so-called Z-scheme was proposed. Concurrent with the establishment of Mitchell's Chemiosmotic Hypothesis for electron transfer and phosphorylation, the experimental bilayer lipid membrane (BLM) system was developed in 1960. But what are the fundamental biophysical mechanisms involved in the phototransduction via pigmented bilayer lipid membrane-based transducers? One of the main purposes of this review is to consider these questions. A second main purpose is to introduce to the reader the experimental aspects of lipid bilayers in the investigation of photoactive biomembranes. The areas covered in this review include a brief summary of the laws of photochemistry relevant to membrane photobiophysics and photobiology. The current exploitation of the BLM system in relation to the thylakoid membrane and to the visual receptor membrane will be considered in turn. The purple membrane of H. Halobium is then discussed. Consideration will also be given to dye-sensitized BLMs, semiconducting BLMs, and BLMs formed from liquid crystals. A common characteristic in the topics covered in this review is the desire to stimulate further studies in the use of the BLM system, not only for the fundamental understanding of biomembranes, but also towards

  5. Purple drank prevalence and characteristics of misusers of codeine cough syrup mixtures.

    PubMed

    Agnich, Laura E; Stogner, John M; Miller, Bryan Lee; Marcum, Catherine D

    2013-09-01

    A mixture of codeine cough syrup with alcohol and/or a soft drink known as "purple drank" has gained media attention in recent years as a drug associated with professional athletes and southern rap music. The existing research on purple drank consumption has primarily utilized samples of African Americans residing in the Houston, Texas area. This is the first scholarly study of purple drank use outside of the Houston, Texas area among a general population of young adults, and indicates that purple drank use is not limited to African American males. The findings depict higher odds of the use of purple drank among other racial and ethnic groups, males, and homosexual, bisexual, and transgender college students from urban areas. PMID:23688907

  6. Expression pattern and subcellular localization of Arabidopsis purple acid phosphatase AtPAP9.

    PubMed

    Zamani, Katayoun; Lohrasebi, Tahmineh; Sabet, Mohammad S; Malboobi, Mohammad A; Mousavi, Amir

    2014-01-01

    Purple acid phosphatase (PAP; EC 3.1.3.2) enzymes are metallophosphoesterases that hydrolysis phosphate ester bonds in a wide range of substrates. Twenty-nine PAP-encoding loci have been identified in the Arabidopsis genome, many of which have multiple transcript variants expressed in response to diverse environmental conditions. Having analyzed T-DNA insertion mutants, we have provided strong pieces of evidence that AtPAP9 locus encodes at least two types of transcripts, designated as AtPAP9-1 and AtPAP9-2. These transcript variants expressed distinctly during the course of growth in medium containing sufficient phosphate or none. Further histochemical analysis by the use of AtPAP9-1 promoter fused to β-glucuronidase reporter gene indicated the expression of this gene is regulated in a tissue-specific manner. AtPAP9-1 was highly expressed in stipule and vascular tissue, particularly in response to fungal infection. Subcellular localization of AtPAP9-1:green fluorescent fusion protein showed that it must be involved in plasma membrane and cell wall adhesion. PMID:24012521

  7. Golgi fragmentation in Alzheimer's disease

    PubMed Central

    Joshi, Gunjan; Bekier, Michael E.; Wang, Yanzhuang

    2015-01-01

    The Golgi apparatus is an essential cellular organelle for post-translational modifications, sorting, and trafficking of membrane and secretory proteins. Proper functionality of the Golgi requires the formation of its unique cisternal-stacking morphology. The Golgi structure is disrupted in a variety of neurodegenerative diseases, suggesting a common mechanism and contribution of Golgi defects in neurodegenerative disorders. A recent study on Alzheimer's disease (AD) revealed that phosphorylation of the Golgi stacking protein GRASP65 disrupts its function in Golgi structure formation, resulting in Golgi fragmentation. Inhibiting GRASP65 phosphorylation restores the Golgi morphology from Aβ-induced fragmentation and reduces Aβ production. Perturbing Golgi structure and function in neurons may directly impact trafficking, processing, and sorting of a variety of proteins essential for synaptic and dendritic integrity. Therefore, Golgi defects may ultimately promote the development of AD. In the current review, we focus on the cellular impact of impaired Golgi morphology and its potential relationship to AD disease development. PMID:26441511

  8. Diversity of extremophilic purple phototrophic bacteria in Soap Lake, a Central Washington (USA) Soda Lake.

    PubMed

    Asao, Marie; Pinkart, Holly C; Madigan, Michael T

    2011-08-01

    Culture-based and culture-independent methods were used to explore the diversity of phototrophic purple bacteria in Soap Lake, a small meromictic soda lake in the western USA. Among soda lakes, Soap Lake is unusual because it consists of distinct upper and lower water bodies of vastly different salinities, and its deep waters contain up to 175 mM sulfide. From Soap Lake water new alkaliphilic purple sulfur bacteria of the families Chromatiaceae and Ectothiorhodospiraceae were cultured, and one purple non-sulfur bacterium was isolated. Comparative sequence analysis of pufM, a gene that encodes a key photosynthetic reaction centre protein universally found in purple bacteria, was used to measure the diversity of purple bacteria in Soap Lake. Denaturing gradient gel electrophoresis and subsequent phylogenetic analyses of pufMs amplified from Soap Lake water revealed that a significant diversity of purple bacteria inhabit this soda lake. Although close relatives of several of the pufM phylotypes obtained from cultured species could also be detected in Soap Lake water, several other more divergent pufM phylotypes were also detected. It is possible that Soap Lake purple bacteria are major contributors of organic matter into the ecosystem of this lake, especially in its extensive anoxic and sulfidic deep waters. PMID:21410624

  9. Transcriptome Analysis of Purple Pericarps in Common Wheat (Triticum aestivum L.)

    PubMed Central

    Chen, Wenjie; Zhang, Bo; Liu, Dengcai; Liu, Baolong; Zhang, Huaigang

    2016-01-01

    Wheat (Triticum aestivum L.) cultivars possessing purple grain arethought to be more nutritious because of high anthocyanin contents in the pericarp. Comparative transcriptome analysis of purple (cv Gy115) and white pericarps was carried out using next-generation sequencing technology. There were 23,642 unigenes significantly differentially expressed in the purple and white pericarps, including 9945 up-regulated and 13,697 down-regulated. The differentially expressed unigenes were mainly involved in encoding components of metabolic pathways, The flavonoid biosynthesis pathway was the most represented in metabolic pathways. In the transcriptome of purple pericarp in Gy115, most structural and regulatory genes biosynthesizing anthocyanin were identified, and had higher expression levels than in white pericarp. The largestunigene of anthocyanin biosynthesis in Gy115 was longer than the reference genes, which implies that high-throughput sequencing could isolate the genes of anthocyanin biosynthesis in tissues or organs with high anthocyanin content. Based on present and previous results, three unigenes of MYB gene on chromosome 7BL and three unigenes of MYC on chromosome 2AL were predicted as candidate genes for the purple grain trait. This article was the first to provide a systematic overview comparing the transcriptomes of purple and white pericarps in common wheat, which should be very valuable for identifying the key genes for the purple pericarp trait. PMID:27171148

  10. Occurrence of Purple Sulfur Bacteria in a Sewage Treatment Lagoon 1

    PubMed Central

    Holm, H. W.; Vennes, J. W.

    1970-01-01

    The ecology of purple sulfur bacteria in a sewage oxidation lagoon was investigated. Chemical changes in the lagoon were investigated by monitoring biochemical oxygen demand (BOD5), sulfide, sulfate, phosphate, total carbohydrates, volatile acids, alkalinity, and pH. Lagoon water temperatures were observed daily. Microbial ecological relationships were deduced by enumerating coliforms, total bacteria other than anaerobes [Tryptone Glucose Extract (TGE) agar], methane formers such as Methanobacterium formicicum, sulfate reducers, purple sulfur bacteria, and algae. Finally, two strains of purple sulfur bacteria were characterized. Two populations, purple sulfur bacteria and total bacteria (TGE agar), reached maximal concentrations in the warmest part of the 1967 summer. Purple sulfur bacteria reached maximal numbers as concentrations of sulfide and volatile acids were depleted, whereas carbohydrates and alkalinity remained unchanged. Low sulfate levels, which were not limiting for sulfate reducers, may be attributable to storage of sulfur within purple sulfur bacteria. No biological, chemical, or physical agent was linked to the removal of coliforms. The increase of algae in the late summer of 1967 may have been related to the low organic content of the lagoon during this period. Although lagoon pH (7.7 to 8.2) was favorable for purple sulfur bacterial growth, temperatures and sulfides were not optimal in the lagoon for these organisms. Chromatium vinosum and Thiocapsa floridana (the predominant lagoon purple sulfur organism in 1967 and 1968) utilized certain carbohydrates, amino acids, volatile acids, and Krebs cycle intermediates. Also purple sulfur bacteria lowered BOD levels as demonstrated by the growth of T. floridana in sterilized sewage. PMID:4917194

  11. Localization of glycolipids in membranes by in vivo labeling and neutron diffraction.

    PubMed

    Weik, M; Patzelt, H; Zaccai, G; Oesterhelt, D

    1998-02-01

    Evidence is accumulating for the lateral organization of cell membrane lipids and proteins in the context of sorting or intracellular signaling. So far, however, information has been lacking on the details of protein-lipid interactions in such aggregates. Purple membranes are patches made up of lipids and the protein bacteriorhodopsin in the plasma membrane of certain Archaea. Naturally crystalline, they provide a unique opportunity to study the structure of a natural membrane at submolecular resolution by diffraction methods. We present a direct structural determination of the glycolipids with respect to bacteriorhodopsin in these membranes. Deuterium labels incorporated in vivo into the sugar moieties of the major glycolipid were localized by neutron diffraction. The data suggest a role for specific aromatic residue-carbohydrate stacking interactions in the formation of the purple membrane crystalline patches. PMID:9660925

  12. Unique structural features of red kidney bean purple acid phosphatase.

    PubMed

    Cashikar, A G; Rao, M N

    1995-06-01

    Purple acid phosphatase from red kidney beans (Phaseolus vulgaris) has been purified to homogeneity and characterized. The enzyme is a homodimer of 60 kDa subunits each containing one atom of zinc and iron in the active site. Circular dichroism spectral studies on the purified enzyme reveals that a large portion of the peptide backbone is in the unordered and beta-turn conformation. A unique feature of the red kidney bean acid phosphatase, which we have found, is that one of the two cysteines of each subunit is involved in the formation of an inter-subunit disulphide. The thiol group of the other cysteine is not necessary for the activity of the enzyme. Western blot analysis with antibodies raised against kidney bean acid phosphatase could not recognize acid phosphatases from other sources except from potato. This paper emphasizes the fact that acid phosphatases are functionally, but not structurally, conserved enzymes. PMID:7590853

  13. Popping Balloons: A Case Study of Dynamical Fragmentation

    NASA Astrophysics Data System (ADS)

    Moulinet, Sébastien; Adda-Bedia, Mokhtar

    2015-10-01

    Understanding the physics of fragmentation is important in a wide range of industrial and geophysical applications. Fragmentation processes involve large strain rates and short time scales that take place during crack nucleation and propagation. Using rubber membranes, we develop an experimental analysis that enables us to track the fragmentation process in situ in both time and space. We find that bursting a highly stretched membrane yields a treelike fragmentation network that originates at a single seed crack, followed by successive crack tip-splitting events. We show that a dynamic instability drives this branching mechanism. Fragmentation occurs when the crack tip speed attains a critical velocity for which tip splitting becomes the sole available mechanism of releasing the stored elastic energy. Given the general character of the fragmentation processes, this framework should be applicable to other crack networks in brittle materials.

  14. Popping Balloons: A Case Study of Dynamical Fragmentation.

    PubMed

    Moulinet, Sébastien; Adda-Bedia, Mokhtar

    2015-10-30

    Understanding the physics of fragmentation is important in a wide range of industrial and geophysical applications. Fragmentation processes involve large strain rates and short time scales that take place during crack nucleation and propagation. Using rubber membranes, we develop an experimental analysis that enables us to track the fragmentation process in situ in both time and space. We find that bursting a highly stretched membrane yields a treelike fragmentation network that originates at a single seed crack, followed by successive crack tip-splitting events. We show that a dynamic instability drives this branching mechanism. Fragmentation occurs when the crack tip speed attains a critical velocity for which tip splitting becomes the sole available mechanism of releasing the stored elastic energy. Given the general character of the fragmentation processes, this framework should be applicable to other crack networks in brittle materials. PMID:26565468

  15. Selectable fragmentation warhead

    DOEpatents

    Bryan, Courtney S.; Paisley, Dennis L.; Montoya, Nelson I.; Stahl, David B.

    1993-01-01

    A selectable fragmentation warhead capable of producing a predetermined number of fragments from a metal plate, and accelerating the fragments toward a target. A first explosive located adjacent to the plate is detonated at selected number of points by laser-driven slapper detonators. In one embodiment, a smoother-disk and a second explosive, located adjacent to the first explosive, serve to increase acceleration of the fragments toward a target. The ability to produce a selected number of fragments allows for effective destruction of a chosen target.

  16. Selectable fragmentation warhead

    SciTech Connect

    Bryan, C.S.; Paisley, D.L.; Montoya, N.I.; Stahl, D.B.

    1992-12-31

    This report discusses a selectable fragmentation warhead which is capable of producing a predetermined number of fragments from a metal plate, and accelerating the fragments toward a target. A first explosive located adjacent to the plate is detonated at selected number of points by laser-driven slapper detonators. In one embodiment, a smoother-disk and a second explosive, located adjacent to the first explosive, serve to increase acceleration of the fragments toward a target. The ability to produce a selected number of fragments allows for effective destruction of a chosen target.

  17. The Modulatory Effect of Anthocyanins from Purple Sweet Potato on Human Intestinal Microbiota in Vitro.

    PubMed

    Zhang, Xin; Yang, Yang; Wu, Zufang; Weng, Peifang

    2016-03-30

    In order to investigate the modulatory effect of purple sweet potato anthocyanins (PSPAs) on human intestinal microbiota, PSPAs were prepared by column chromatography and their influence on intestinal microbiota was analyzed by monitoring the bacterial populations and analyzing short-chain fatty acid (SCFA) concentrations at different time points. The numbers (log10 cell/mL) of Bifidobacterium and Lactobacillus/Enterococcus spp., Bacteroides-Prevotella, Clostridium histolyticum, and total bacteria after 24 h of culture in anaerobic fermentation broth containing PSPAs were 8.44 ± 0.02, 8.30 ± 0.01, 7.80 ± 0.03, 7.60 ± 0.03, and 9.00 ± 0.02, respectively, compared with 8.21 ± 0.03, 8.12 ± 0.02, 7.95 ± 0.02, 7.77 ± 0.02, and 9.01 ± 0.03, respectively, in the controls. The results showed that PSPAs induced the proliferation of Bifidobacterium and Lactobacillus/Enterococcus spp., inhibited the growth of Bacteroides-Prevotella and Clostridium histolyticum, and did not affect the total bacteria number. Total SCFA concentrations in the cultures with PSPAs were significantly higher than in the controls (P < 0.05). Moreover, during the fermentation, the PSPAs were partially fragmented to phenolic acids, which may exert a better effect on intestinal microecology, suggesting that PSPAs may have prebiotic-like activity by generating SCFAs and modulating the intestinal microbiota, contributing to improvements in human health. PMID:26975278

  18. A unilateral purple urine bag syndrome in a patient with bilateral nephrostomy tubes.

    PubMed

    Karim, Adil; Abed, Firas; Bachuwa, Ghassan

    2015-01-01

    A change in the colour of urine is always of clinical significance, and a source of concern for the patient and his physician. Among the different urine colours observed, purple is the least common. Although purple discolouration of a catheter and a urine bag is an uncommon finding, it was reported in the literature as early as 1978, by Barlow and Dickson. We present a unique case of purple urine bag syndrome in a patient with bilateral nephrostomy tubes (NT) and associated urine bags (UB) with only the left nephrostomy tube and urine bag exhibiting the purple colour, which resolved with a course of appropriate antibiotics eradicating the causative bacterial pathogen, and change of NT and UB. PMID:26701992

  19. Anthocyanins in purple and blue wheat grains and in resulting bread: quantity, composition, and thermal stability.

    PubMed

    Bartl, Pavel; Albreht, Alen; Skrt, Mihaela; Tremlová, Bohuslava; Ošťádalová, Martina; Šmejkal, Karel; Vovk, Irena; Ulrih, Nataša Poklar

    2015-01-01

    The anthocyanin composition of blue (Triticum aestivum L., cv. Skorpion) and purple wheat (Triticum aethiopicum JAKUBZ cv. Abyssinskaja arrasajta cv. Abyssinskaja arrasajta), cultivated in the Czech Republic, and of the prepared whole blue and purple wheat bread was determined. In blue and purple wheat, 19 and 26 anthocyanins, respectively, were tentatively identified by liquid chromatography and mass spectrometry. The total content of anthocyanins determined in blue and purple wheat was 9.26 and 13.23 mgkg(-1), respectively. The breads were baked at 240 and 180 °C. Some significant differences in anthocyanins content were observed between breads prepared at different baking temperatures. The content of cyanidin-3-glucoside, delphinidin-3-glucoside and pelargonidin-3-glucoside was determinated in starting material, whole meal flours and baked breads. These kinds of wheat are suitable for baking bread, since intake of anthocyanins may play an important role in the prevention of human diseases. PMID:26088282

  20. The purple coloration of four late 19th century silk dresses: A spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Woodhead, Andrea L.; Cosgrove, Bronwyn; Church, Jeffrey S.

    2016-02-01

    Prior to the 19th century the use of purple dyes for textile coloration was expensive and usually limited to royalty. The discovery of several synthetic purple dyes during the 19th century made the production of purple textiles more affordable and thus more readily available. The identification of the source of the purple coloration is of historical interest. Small yarn samples from four late 19th century silk dresses were analyzed using a combination of thin layer chromatography and surface enhanced Raman spectroscopy, Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy. This combination of techniques enabled the analysis of the complex extraction products. While three of the dresses were found to be dyed using methyl violet, the fourth dress was found to be constructed from a warp yarn dyed with methyl violet in the presence of a tannic acid mordant, and a weft yarn dyed with mauve and a tin mordant.

  1. The purple coloration of four late 19th century silk dresses: A spectroscopic investigation.

    PubMed

    Woodhead, Andrea L; Cosgrove, Bronwyn; Church, Jeffrey S

    2016-02-01

    Prior to the 19th century the use of purple dyes for textile coloration was expensive and usually limited to royalty. The discovery of several synthetic purple dyes during the 19th century made the production of purple textiles more affordable and thus more readily available. The identification of the source of the purple coloration is of historical interest. Small yarn samples from four late 19th century silk dresses were analyzed using a combination of thin layer chromatography and surface enhanced Raman spectroscopy, Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy. This combination of techniques enabled the analysis of the complex extraction products. While three of the dresses were found to be dyed using methyl violet, the fourth dress was found to be constructed from a warp yarn dyed with methyl violet in the presence of a tannic acid mordant, and a weft yarn dyed with mauve and a tin mordant. PMID:26523685

  2. Purple toes syndrome associated with warfarin therapy in a patient with antiphospholipid syndrome.

    PubMed

    Talmadge, David B; Spyropoulos, Alex C

    2003-05-01

    Purple toes syndrome is an extremely uncommon, nonhemorrhagic, cutaneous complication associated with warfarin therapy. It is characterized by the sudden appearance of bilateral, painful, purple lesions on the toes and sides of the feet that blanch with pressure. The syndrome usually develops 3-8 weeks after the start of warfarin therapy. A 47-year-old man with a history of purple toes syndrome that resolved after discontinuing warfarin--prescribed for a deep vein thrombosis (DVT) in his right lower leg--experienced an acute, proximal DVT in his other leg. Warfarin again was prescribed; 1 week later, purple toes syndrome developed in that extremity. Warfarin therapy again was discontinued, and intravenous unfractionated heparin was started; the patient's clinical picture indicated a possible pulmonary embolism, and laboratory analysis suggested antiphospholipid syndrome. The patient's toe pain resolved, but the purple discoloration persisted. Follow-up laboratory analysis confirmed antiphospholipid syndrome, and warfarin was restarted with close monitoring. No further complications occurred with long-term therapy. Although a rare complication of therapy, clinicians should monitor for the development of purple toes syndrome in patients taking warfarin. PMID:12741443

  3. Non-invasive investigation on a VI century purple codex from Brescia, Italy.

    PubMed

    Aceto, Maurizio; Idone, Ambra; Agostino, Angelo; Fenoglio, Gaia; Gulmini, Monica; Baraldi, Pietro; Crivello, Fabrizio

    2014-01-01

    Purple codices are among the most relevant and prestigious book productions of Late Antique and Medieval age. They usually contained texts from Holy Writings written with golden or silver inks on parchment dyed in a purple hue. According to the tradition, the colour of parchment was obtained by the well renowned Tyrian purple dye. From the material point of view, however, very little is known about the compounds actually used in the manufacture of these manuscripts. Presently, the information available is limited to the ancient art treatises, with very few diagnostic evidences supporting them and, moreover, none confirming the presence of Tyrian purple. It is more than apparent, then, the need to have at disposal larger and more complete information at the concern, in order to verify what came to us from the literary tradition only. In this study, preliminary results are presented from non-invasive investigation on a VI century purple codex, the so-called CodexBrixianus, held in the Biblioteca Civica Queriniana at Brescia (Italy). Analyses were carried out with XRF spectrometry, UV-visible diffuse reflectance spectrophotometry, molecular spectrofluorimetry and optical microscopy. The results suggest the hypothesis that Tyrian purple had been used as a minor component mixed with other less precious dyes such as folium or orchil. PMID:23981412

  4. Non-invasive investigation on a VI century purple codex from Brescia, Italy

    NASA Astrophysics Data System (ADS)

    Aceto, Maurizio; Idone, Ambra; Agostino, Angelo; Fenoglio, Gaia; Gulmini, Monica; Baraldi, Pietro; Crivello, Fabrizio

    2014-01-01

    Purple codices are among the most relevant and prestigious book productions of Late Antique and Medieval age. They usually contained texts from Holy Writings written with golden or silver inks on parchment dyed in a purple hue. According to the tradition, the colour of parchment was obtained by the well renowned Tyrian purple dye. From the material point of view, however, very little is known about the compounds actually used in the manufacture of these manuscripts. Presently, the information available is limited to the ancient art treatises, with very few diagnostic evidences supporting them and, moreover, none confirming the presence of Tyrian purple. It is more than apparent, then, the need to have at disposal larger and more complete information at the concern, in order to verify what came to us from the literary tradition only. In this study, preliminary results are presented from non-invasive investigation on a VI century purple codex, the so-called CodexBrixianus, held in the Biblioteca Civica Queriniana at Brescia (Italy). Analyses were carried out with XRF spectrometry, UV-visible diffuse reflectance spectrophotometry, molecular spectrofluorimetry and optical microscopy. The results suggest the hypothesis that Tyrian purple had been used as a minor component mixed with other less precious dyes such as folium or orchil.

  5. Purple: A Modular System for Developing and Deploying Behavioral Intervention Technologies

    PubMed Central

    Schueller, Stephen M; Begale, Mark; Penedo, Frank J

    2014-01-01

    The creation, deployment, and evaluation of Web-based and mobile-based applications for health, mental health, and wellness within research settings has tended to be siloed, with each research group developing their own systems and features. This has led to technological features and products that are not sharable across research teams, thereby limiting collaboration, reducing the speed of dissemination, and raising the bar for entry into this area of research. This paper provides an overview of Purple, an extensible, modular, and repurposable system created for the development of Web-based and mobile-based applications for health behavior change. Purple contains features required to construct applications and to manage and evaluate research trials using these applications. Core functionality of Purple includes elements that support user management, content authorship, content delivery, and data management. We discuss the history and development of the Purple system guided by the rationale of producing a system that allows greater collaboration and understanding across research teams interested in investigating similar questions and using similar methods. Purple provides a useful tool to meet the needs of stakeholders involved in the creation, provision, and usage of eHealth and mHealth applications. Housed in a non-profit, academic institution, Purple also offers the potential to facilitate the diffusion of knowledge across the research community and improve our capacity to deliver useful and usable applications that support the behavior change of end users. PMID:25079298

  6. Proliferation of Purple Sulphur Bacteria at the Sediment Surface Affects Intertidal Mat Diversity and Functionality

    PubMed Central

    Hubas, Cédric; Jesus, Bruno; Ruivo, Mickael; Meziane, Tarik; Thiney, Najet; Davoult, Dominique; Spilmont, Nicolas; Paterson, David M.; Jeanthon, Christian

    2013-01-01

    There is a relative absence of studies dealing with mats of purple sulphur bacteria in the intertidal zone. These bacteria display an array of metabolic pathways that allow them to disperse and develop under a wide variety of conditions, making these mats important in terms of ecosystem processes and functions. Mass blooms of purple sulphur bacteria develop during summer on sediments in the intertidal zone especially on macroalgal deposits. The microbial composition of different types of mats differentially affected by the development of purple sulphur bacteria was examined, at low tide, using a set of biochemical markers (fatty acids, pigments) and composition was assessed against their influence on ecosystem functions (sediment cohesiveness, CO2 fixation). We demonstrated that proliferation of purple sulphur bacteria has a major impact on intertidal mats diversity and functions. Indeed, assemblages dominated by purple sulphur bacteria (Chromatiaceae) were efficient exopolymer producers and their biostabilisation potential was significant. In addition, the massive growth of purple sulphur bacteria resulted in a net CO2 degassing whereas diatom dominated biofilms represented a net CO2 sink. PMID:24340018

  7. Universality of fragment shapes.

    PubMed

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-01-01

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism. PMID:25772300

  8. Universality of fragment shapes

    PubMed Central

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-01-01

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism. PMID:25772300

  9. Universality of fragment shapes

    NASA Astrophysics Data System (ADS)

    Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea

    2015-03-01

    The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.

  10. Fragmentation properties of metals

    SciTech Connect

    Grady, D.E.; Kipp, M.E.

    1996-06-01

    In the present study we are developing an experimental fracture material property test method specific to dynamic fragmentation. Spherical test samples of the metals of interest are subjected to controlled impulsive stress loads by acceleration to high velocities with a light-gas launcher facility and subsequent normal impact on thin plates. Motion, deformation and fragmentation of the test samples are diagnosed with multiple flash radiography methods. The impact plate materials are selected to be transparent to the x-ray method so that only test metal material is imaged. Through a systematic series of such tests, both strain-to-failure and fragmentation resistance properties are determined through this experimental method. Fragmentation property data for several steels, copper, aluminum, tantalum and titanium have been obtained to date. Aspects of the dynamic data have been analyzed with computational methods to achieve a better understanding of the processes leading to failure and fragmentation, and to test an existing computational fragmentation model.

  11. Purple L1 Milestone Review Panel GPFS Functionality and Performance

    SciTech Connect

    Loewe, W E

    2006-12-01

    The GPFS deliverable for the Purple system requires the functionality and performance necessary for ASC I/O needs. The functionality includes POSIX and MPIIO compatibility, and multi-TB file capability across the entire machine. The bandwidth performance required is 122.15 GB/s, as necessary for productive and defensive I/O requirements, and the metadata performance requirement is 5,000 file stats per second. To determine success for this deliverable, several tools are employed. For functionality testing of POSIX, 10TB-files, and high-node-count capability, the parallel file system bandwidth performance test IOR is used. IOR is an MPI-coordinated application that can write and then read to a single shared file or to an individual file per process and check the data integrity of the file(s). The MPIIO functionality is tested with the MPIIO test suite from the MPICH library. Bandwidth performance is tested using IOR for the required 122.15 GB/s sustained write. All IOR tests are performanced with data checking enabled. Metadata performance is tested after ''aging'' the file system with 80% data block usage and 20% inode usage. The fdtree metadata test is expected to create/remove a large directory/file structure in under 20 minutes time, akin to interactive metadata usage. Multiple (10) instances of ''ls -lR'', each performing over 100K stats, are run concurrently in different large directories to demonstrate 5,000 stats/sec.

  12. Red, purple and pink: the colors of diffusion on pinterest.

    PubMed

    Bakhshi, Saeideh; Gilbert, Eric

    2015-01-01

    Many lab studies have shown that colors can evoke powerful emotions and impact human behavior. Might these phenomena drive how we act online? A key research challenge for image-sharing communities is uncovering the mechanisms by which content spreads through the community. In this paper, we investigate whether there is link between color and diffusion. Drawing on a corpus of one million images crawled from Pinterest, we find that color significantly impacts the diffusion of images and adoption of content on image sharing communities such as Pinterest, even after partially controlling for network structure and activity. Specifically, Red, Purple and pink seem to promote diffusion, while Green, Blue, Black and Yellow suppress it. To our knowledge, our study is the first to investigate how colors relate to online user behavior. In addition to contributing to the research conversation surrounding diffusion, these findings suggest future work using sophisticated computer vision techniques. We conclude with a discussion on the theoretical, practical and design implications suggested by this work-e.g. design of engaging image filters. PMID:25658423

  13. Characteristics of purple nonsulfur bacteria grown under Stevia residue extractions.

    PubMed

    Xu, J; Feng, Y; Wang, Y; Lin, X

    2013-11-01

    As a consequence of the large-scale cultivation of Stevia plants, releases of plant residues, the byproduct after sweetener extraction, to the environment are inevitable. Stevia residue and its effluent after batching up contain large amounts of organic matters with small molecular weight, which therefore are a potential pollution source. Meanwhile, they are favourite substrates for micro-organism growths. This investigation was aimed to utilize the simulated effluent of Stevia residue to enrich the representative purple nonsulfur bacterium (PNSB), Rhodopseudomonas palustris (Rps. palustris), which has important economic values. The growth profile and quality of Rps. palustris were characterized by spectrophotometry, compared to those grown in common PNSB mineral synthetic medium. Our results revealed that the simulated effluent of Stevia residue not only stimulated Rps. palustris growth to a greater extent, but also increased its physiologically active cytochrome concentrations and excreted indole-3-acetic acid (IAA) content. This variation in phenotype of Rps. palustris could result from the shift in its genotype, further revealed by the repetitive sequence-based PCR (rep-PCR) fingerprinting analysis. Our results showed that the effluent of Stevia residue was a promising substrate for microbial growth. PMID:23837648

  14. Calibration of Solar Radio Spectrometer of the Purple Mountain Observatory

    NASA Astrophysics Data System (ADS)

    Lei, LU; Si-ming, LIU; Qi-wu, SONG; Zong-jun, NING

    2015-10-01

    Calibration is a basic and important job in solar radio spectral observations. It not only deduces the solar radio flux as an important physical quantity for solar observations, but also deducts the flat field of the radio spectrometer to display the radio spectrogram clearly. In this paper, we first introduce the basic method of calibration based on the data of the solar radio spectrometer of Purple Mountain Observatory. We then analyze the variation of the calibration coefficients, and give the calibrated results for a few flares. These results are compared with those of the Nobeyama solar radio polarimeter and the hard X-ray observations of the RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) satellite, it is shown that these results are consistent with the characteristics of typical solar flare light curves. In particular, the analysis on the correlation between the variation of radio flux and the variation of hard X-ray flux in the pulsing phase of a flare indicates that these observations can be used to study the relevant radiation mechanism, as well as the related energy release and particle acceleration processes.

  15. Red, Purple and Pink: The Colors of Diffusion on Pinterest

    PubMed Central

    Bakhshi, Saeideh; Gilbert, Eric

    2015-01-01

    Many lab studies have shown that colors can evoke powerful emotions and impact human behavior. Might these phenomena drive how we act online? A key research challenge for image-sharing communities is uncovering the mechanisms by which content spreads through the community. In this paper, we investigate whether there is link between color and diffusion. Drawing on a corpus of one million images crawled from Pinterest, we find that color significantly impacts the diffusion of images and adoption of content on image sharing communities such as Pinterest, even after partially controlling for network structure and activity. Specifically, Red, Purple and pink seem to promote diffusion, while Green, Blue, Black and Yellow suppress it. To our knowledge, our study is the first to investigate how colors relate to online user behavior. In addition to contributing to the research conversation surrounding diffusion, these findings suggest future work using sophisticated computer vision techniques. We conclude with a discussion on the theoretical, practical and design implications suggested by this work—e.g. design of engaging image filters. PMID:25658423

  16. Identification and quantification of anthocyanins in transgenic purple tomato.

    PubMed

    Su, Xiaoyu; Xu, Jianteng; Rhodes, Davina; Shen, Yanting; Song, Weixing; Katz, Benjamin; Tomich, John; Wang, Weiqun

    2016-07-01

    Anthocyanins are natural pigments derived from the phenylpropanoid pathway. Most tomatoes produce little anthocyanins, but the transgenic purple tomato biosynthesizes a high level of anthocyanins due to expression of two transcription factors (Del and Ros1). This study was to identify and quantify anthocyanins in this transgenic tomato line. Seven anthocyanins, including two new anthocyanins [malvidin-3-(p-coumaroyl)-rutinoside-5-glucoside and malvidin-3-(feruloyl)-rutinoside-5-glucoside], were identified by LC-MS/MS. Petunidin-3-(trans-coumaroyl)-rutinoside-5-glucoside and delphinidin-3-(trans-coumaroyl)-rutinoside-5-glucoside were the most abundant anthocyanins, making up 86% of the total anthocyanins. Compared to undetectable anthocyanins in the wild type, the contents of anthocyanins in the whole fruit, peel, and flesh of the Del/Ros1-transgenic tomato were 5.2±0.5, 5.1±0.5, and 5.8±0.3g/kg dry matter, respectively. Anthocyanins were undetectable in the seeds of both wide-type and transgenic tomato lines. Such novel and high levels of anthocyanins obtained in this transgenic tomato may provide unique functional products with potential health benefits. PMID:26920283

  17. Towards a semiquantitative non invasive characterisation of Tyrian purple dye composition: Convergence of UV-Visible reflectance spectroscopy and fast-high temperature-high performance liquid chromatography with photodiode array detection.

    PubMed

    Clementi, Catia; Nowik, Witold; Romani, Aldo; Cardon, Dominique; Trojanowicz, Marek; Davantès, Athénaïs; Chaminade, Pierre

    2016-07-01

    In this paper, partial least square (PLS) regression is innovatively applied for a semi-quantitative non invasive study of the most precious dye of Antiquity: Tyrian purple. This original approach for the study of organic dyes in the cultural heritage field, is based on the correlation of spectrophotometric (UV-Visible) and chromatographic (Fast-HT-HPLC-PDA) data from an extensive set of textiles prepared with different snail species according to historical recipes. A cross-validated PLS model, based on the quantity of 6,6'-dibromoindigotin, displays an excellent correlation factor (R(2)Y = 0.987) between values determined by chromatography and those predicted from reflectance spectra. This indicates that the spectral features of Tyrian purple on textile fibre is strictly related to the amount of this indigoid component whose content may be non invasively predicted from reflectance spectrum. The studied correlation also highlights that, independently of the dyeing method and nature of the textile fibre used, the relative content of 6,6'-dibromindigotin may be used as a parameter to distinguish samples prepared with Hexaplex trunculus L. snails from those prepared with further mollusc species. To validate this model, archaeological textile fragments dating from the Roman period were successfully examined. The results achieved open an absolutely new way in Tyrian purple analysis in cultural heritage by non invasive spectroscopic techniques attesting their convergence with HPLC and giving them a semi-quantitative value. PMID:27216389

  18. Optical and electric signals from dried oriented purple membrane of bacteriorhodopsins.

    PubMed

    Tóth-Boconádi, R; Dér, A; Keszthelyi, L

    2011-04-01

    All the intermediates of the bacteriorhodopsin photocycle are excitable with light of suitable wavelength. This property might regulate the activity in the cells when they are exposed in the nature to high light intensity. On the other hand this property is involved in many applications. In this study the ground state and M intermediate of dried oriented samples of wild-type bacteriorhodopsin and its mutant D96N were excited with 406 nm laser flashes. Substantial M populations were generated with quasi-continuous illumination. The decay of the absorption of M intermediate had three components: their lifetimes were very different for laser flash and quasi-continuous illuminations in cases of both bacteriorhodopsin species. The optical answer for the excitation of M intermediate had a lifetime of 2.2 ms. Electric signals for M excitation had large fast negative components and small positive components in the 100 μs time domain. The results are expected to have important implications for bioelectronic applications of bacteriorhodopsin. PMID:21236739

  19. Fragments and Coherence

    ERIC Educational Resources Information Center

    Watson, Anne

    2008-01-01

    Can teachers contact the inner coherence of mathematics while working in a context fragmented by always-new objectives, criteria, and initiatives? How, more importantly, can learners experience the inner coherence of mathematics while working in a context fragmented by testing, modular curricular, short-term learning objectives, and lessons that…

  20. Fluctuations in nuclear fragmentation

    SciTech Connect

    Aranda, A.; Dorso, C.O.; Furci, V.; Lopez, J.A.

    1995-12-01

    Heavy ion collisions can be used to study the thermodynamics of hot and dense nuclear matter only if the initial mass and energy fluctuations that lead to fragmentation are of thermal origin and survive the disassembly process. If this is the case, the observed fragment multiplicity should be directly related to those initial fluctuations and to the conditions of temperature and density causing them. The feasibility of this scenario is demonstrated with a molecular dynamics study of the evolution of mass and energy fluctuations, and fluctuations of the phase-space density. First, it is verified that the fluctuations leading to fragmentation are indeed early ones. Second, it is determined that different initial conditions of density and temperature can indeed produce varying final fragment multiplicities. The {rho}-{ital T} plane is mapped to the fragment multiplicity with good precision. This mapping should be easily reproducible with existing experimental data.

  1. Photoelectric conversion by bacteriorhodopsin in charged synthetic membranes.

    PubMed Central

    Singh, K; Korenstein, R; Lebedeva, H; Caplan, S R

    1980-01-01

    Photoelectroactivity of oriented purple membrane layers attached to an ion exchange film has been investigated. The action spectrum of the photocurrent followed the absorption spectrum of bacteriorhodopsin. The intactness of structure and function of bacteriorhodopsin was demonstrated by studies of absorption and photocycle kinetics. The direction of the photocurrent suggests that the extracellular surface of purple membrane is more positive. Photocurrents as high as 20 microA cm-2 were obtained in some preparations. The dependence of steady-state photocurrents on intensity of illumination and temperature was also studied. The initial rate of build-up of photocurrent depends linearly on the intensity of illumination while the off rate does not exhibit any dependence on the intensity of illumination. With rise in temperature an increase in the steady state photocurrent has been observed. This dependence was found to be linear when increase of the photocurrent due to proton translocation alone was considered. PMID:7260294

  2. Comparison of loess and purple rill erosions measured with volume replacement method

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-yan; Huang, Yu-han; Zhao, Yu; Mo, Bin; Mi, Hong-xing

    2015-11-01

    Rills are commonly found on sloping farm fields in both the loess and the purple soil regions of China. A comparative study on rill erosion between the two soils is important to increase research knowledge and exchange application experiences. Rill erosion processes of loess and purple soils were determined through laboratory experiments with the volume replacement method. Water was used to refill the eroded rill segments to compute eroded volume before sediment concentration distribution along the rill was computed using the soil bulk density, flow rate, and water flow duration. The experimental loess soil materials were from the Loess Plateau and purple soil from the southwestern part of China, Chongqing City. A laboratory experimental platform was used to construct flumes to simulate rills with 12.0 m length, 0.1 m width, and 0.3 m depth. Soil materials were filled into the flumes at a bulk density of 1.2 g cm-3 to a depth of 20 cm to form rills for experiments on five slope gradients (5°, 10°, 15°, 20°, and 25°) and three flow rates (2, 4, and 8 L/min). After each experimental run under the given slope gradient and flow rate, the rill segments from the upper slope between 0-0.5, 0.5-1, 1-2, 2-3, …, 7-8, 8-10, and 10-12 m were lined with plastic sheets before be re-filled with water to determine sediment concentration after the eroded volumes was measured. Rill erosion differed between the two soils. As purple soil started to erode at a higher erosive force than loess soil, it possibly exhibits higher resistance to water erosion. The subsequent erosion process in the eroding purple rill was similar to that in the loess rill. However, the total erosion in the eroding loess rill was more than that in the eroding purple rill. The maximum sediment concentration transported by the eroding purple rills was significantly lower, approximately 55% of those transported by the loess rills under the same flow rate and slope gradient. Hence, less purple sediments can

  3. Purple Urine Bag Syndrome in Two Elderly Men with Urinary Tract Infection

    PubMed Central

    Van Keer, Jan; Detroyer, Daan; Bammens, Bert

    2015-01-01

    Purple urine bag syndrome is a rare condition in which purple discoloration of urine inside its collection bag occurs. We describe two illustrative cases. The first patient is an 81-year-old man who was hospitalized for a newly diagnosed lymphoma with acute obstructive renal failure for which a nephrostomy procedure was performed. During the hospitalization, a sudden purple discoloration of the suprapubic catheter urine was noted, while the nephrostomy urine had a normal color. Urine culture from the suprapubic catheter was positive for Pseudomonas aeruginosa and Enterococcus faecalis; urine from the nephrostomy was sterile. The second case is an 80-year-old man who was admitted for heart failure with cardiorenal dilemma and who was started on intermittent hemodialysis. There was a sudden purple discoloration of the urine in the collection bag from his indwelling catheter. He was diagnosed with an E. coli urinary infection and treated with amoxicillin and removal of the indwelling catheter. These two cases illustrate the typical characteristics of purple urine bag syndrome. PMID:26351597

  4. Purple Urine Bag Syndrome in Two Elderly Men with Urinary Tract Infection.

    PubMed

    Van Keer, Jan; Detroyer, Daan; Bammens, Bert

    2015-01-01

    Purple urine bag syndrome is a rare condition in which purple discoloration of urine inside its collection bag occurs. We describe two illustrative cases. The first patient is an 81-year-old man who was hospitalized for a newly diagnosed lymphoma with acute obstructive renal failure for which a nephrostomy procedure was performed. During the hospitalization, a sudden purple discoloration of the suprapubic catheter urine was noted, while the nephrostomy urine had a normal color. Urine culture from the suprapubic catheter was positive for Pseudomonas aeruginosa and Enterococcus faecalis; urine from the nephrostomy was sterile. The second case is an 80-year-old man who was admitted for heart failure with cardiorenal dilemma and who was started on intermittent hemodialysis. There was a sudden purple discoloration of the urine in the collection bag from his indwelling catheter. He was diagnosed with an E. coli urinary infection and treated with amoxicillin and removal of the indwelling catheter. These two cases illustrate the typical characteristics of purple urine bag syndrome. PMID:26351597

  5. Baltikinin: A New Myotropic Tryptophyllin-3 Peptide Isolated from the Skin Secretion of the Purple-Sided Leaf Frog, Phyllomedusa baltea.

    PubMed

    Shi, Daning; Xi, Xinping; Wang, Lei; Gao, Yitian; Ma, Chengbang; Chen, Hang; Zhou, Mei; Chen, Tianbao; Shaw, Chris

    2016-01-01

    Here we report the identification of a novel tryptophyllin-3 peptide with arterial smooth muscle relaxation activity from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea. This new peptide was named baltikinin and had the following primary structure, pGluDKPFGPPPIYPV, as determined by tandem mass spectrometry (MS/MS) fragmentation sequencing and from cloned skin precursor-encoding cDNA. A synthetic replicate of baltikinin was found to have a similar potency to bradykinin in relaxing arterial smooth muscle (half maximal effective concentration (EC50) is 7.2 nM). These data illustrate how amphibian skin secretions can continue to provide novel potent peptides that act through functional targets in mammalian tissues. PMID:27399779

  6. Baltikinin: A New Myotropic Tryptophyllin-3 Peptide Isolated from the Skin Secretion of the Purple-Sided Leaf Frog, Phyllomedusa baltea

    PubMed Central

    Shi, Daning; Xi, Xinping; Wang, Lei; Gao, Yitian; Ma, Chengbang; Chen, Hang; Zhou, Mei; Chen, Tianbao; Shaw, Chris

    2016-01-01

    Here we report the identification of a novel tryptophyllin-3 peptide with arterial smooth muscle relaxation activity from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea. This new peptide was named baltikinin and had the following primary structure, pGluDKPFGPPPIYPV, as determined by tandem mass spectrometry (MS/MS) fragmentation sequencing and from cloned skin precursor-encoding cDNA. A synthetic replicate of baltikinin was found to have a similar potency to bradykinin in relaxing arterial smooth muscle (half maximal effective concentration (EC50) is 7.2 nM). These data illustrate how amphibian skin secretions can continue to provide novel potent peptides that act through functional targets in mammalian tissues. PMID:27399779

  7. A new banding technique for nesting adult purple martins

    USGS Publications Warehouse

    Klimkiewicz, M.K.; Jung, P.D.

    1977-01-01

    Mery (1966) showed an almost equal sex ratio, males returned more frequently than females, over 50% of returns paired with other returns, an adult return rate of 20%, and no pair bonds maintained for more than one season. Her study lasted 13 years. Our study has shown that the return rate of locals to parent colonies is 4.1%, sex ratios are nearly equal (combination of banding and observation), return rate of locals to nearby colonies is 0.9,one pair maintained the pair bond for two years, SY females lay fewer eggs than ASY's, SY adults occasionally do not feed frequently enough to maintain the normal growth pattern of the young, SY adults often build poorly constructed nests with little or no mud, overall nest success is lower in SY adults, adults do indeed return to the same colony (19.6%) box and/or compartment, sexes are balanced in a stable colony, males or females are sometimes in excess in a new colony, SY adults are predominate in a new colony, the limiting factor in colony size is most likely the number of boxes and/or compartments available for nesting and,finally, adults and young do indeed use the boxes for roosting after nesting and fledging is complete (even boxes not their own). All of our results are tentative and subject to change after f rther study. Much additional study will be required before we can come up with conclusive answers to many of these questions about the Purple Martin.

  8. Origin of optical activity in the purple bacterial photoreaction center

    SciTech Connect

    Mar, T.; Gingras, G.

    1995-07-18

    The photoreaction center (RC) of purple bacteria contains four bacteriochlorophyll (Bph) and two bacteriopheophytin (Bph) molecules as prosthetic groups. Their optical activity, as measured by circular dichroism (CD) spectroscopy, is largely increased in situ as compared to organic solutions. The all-exciton hypothesis posits that this enhanced optical activity is entirely due to excitonic interactions between the electronic transitions of all six bacteriochlorin molecules. Using the simple exciton theory, this model predicts that the near-infrared CD spectra should be conservative. The fact that they are not, whether the special pair of Bch (SP) that constitutes the primary electron donor is reduced or oxidized, has been explained by hyperchromic effects. The present work tests this hypothesis by successively eliminating the absorption and, therefore, the optical activity of the Bphs and of the non-special-pair (non-SP) Bchs. This was accomplished by trapping these pigments in their reduced state. RC preparations with the four non-SP bacteriochlorins trapped in their reduced state and, therefore, with an intact SP displayed conservative CD spectra. RC preparations with only the electronic transitions of SP and of one non-SP Bch also showed conservative CD spectra. These conservative CD spectra and their corresponding absorption spectra were simulated using simple exciton theory without assuming hyperchromic effects. Bleaching half of the 755-nm absorption band by phototrapping one of the two Bph molecules led to the complete disappearance of the corresponding CD band. This cannot be explained by the all-exciton hypothesis. These results suggest that the optical activity of the SP alone, or with one non-SP Bch, is due to excitonic interactions. They also suggest that the optical activity of the other three bacteriochlorins is due to other factors, such as pigment-protein interaction. 32 refs., 9 figs., 2 tabs.

  9. Behavioral thermoregulation in Hemigrapsus nudus, the amphibious purple shore crab.

    PubMed

    McGaw, I J

    2003-02-01

    The thermoregulatory behavior of Hemigrapsus nudus, the amphibious purple shore crab, was examined in both aquatic and aerial environments. Crabs warmed and cooled more rapidly in water than in air. Acclimation in water of 16 degrees C (summer temperatures) raised the critical thermal maximum temperature (CTMax); acclimation in water of 10 degrees C (winter temperatures) lowered the critical thermal minimum temperature (CTMin). The changes occurred in both water and air. However, these survival regimes did not reflect the thermal preferences of the animals. In water, the thermal preference of crabs acclimated to 16 degrees C was 14.6 degrees C, and they avoided water warmer than 25.5 degrees C. These values were significantly lower than those of the crabs acclimated to 10 degrees C; these animals demonstrated temperature preferences for water that was 17 degrees C, and they avoided water that was warmer than 26.9 degrees C. This temperature preference was also exhibited in air, where 10 degrees C acclimated crabs exited from under rocks at a temperature that was 3.2 degrees C higher than that at which the 16 degrees C acclimated animals responded. This behavioral pattern was possibly due to a decreased thermal tolerance of 16 degrees C acclimated crabs, related with the molting process. H. nudus was better able to survive prolonged exposure to cold temperatures than to warm temperatures, and there was a trend towards lower exit temperatures with the lower acclimation (10 degrees C) temperature. Using a complex series of behaviors, the crabs were able to precisely control body temperature independent of the medium, by shuttling between air and water. The time spent in either air or water was influenced more strongly by the temperature than by the medium. In the field, this species may experience ranges in temperatures of up to 20 degrees C; however, it is able to utilize thermal microhabitats underneath rocks to maintain its body temperature within fairly narrow

  10. Opaque rock fragments

    SciTech Connect

    Abhijit, B.; Molinaroli, E.; Olsen, J.

    1987-05-01

    The authors describe a new, rare, but petrogenetically significant variety of rock fragments from Holocene detrital sediments. Approximately 50% of the opaque heavy mineral concentrates from Holocene siliciclastic sands are polymineralic-Fe-Ti oxide particles, i.e., they are opaque rock fragments. About 40% to 70% of these rock fragments show intergrowth of hm + il, mt + il, and mt + hm +/- il. Modal analysis of 23,282 opaque particles in 117 polished thin sections of granitic and metamorphic parent rocks and their daughter sands from semi-arid and humid climates show the following relative abundances. The data show that opaque rock fragments are more common in sands from igneous source rocks and that hm + il fragments are more durable. They assume that equilibrium conditions existed in parent rocks during the growth of these paired minerals, and that the Ti/Fe ratio did not change during oxidation of mt to hm. Geothermometric determinations using electron probe microanalysis of opaque rock fragments in sand samples from Lake Erie and the Adriatic Sea suggest that these rock fragments may have equilibrated at approximately 900/sup 0/ and 525/sup 0/C, respectively.

  11. Selectable fragmentation warhead

    SciTech Connect

    Bryan, C.S.; Paisley, D.L.; Montoya, N.I.; Stahl, D.B.

    1993-07-20

    A selectable fragmentation warhead is described comprising: a case having proximal and distal ends; a fragmenting plate mounted in said distal end of said casing; first explosive means cast adjacent to said fragmenting plate for creating a predetermined number of fragments from said fragmenting plate; three or more first laser-driven slapper detonators located adjacent to said first explosive means for detonating said first explosive means in a predetermined pattern; smoother-disk means located adjacent to said first means for accelerating said fragments; second explosive means cast adjacent to said smoother-disk means for further accelerating said fragments; at least one laser-driven slapper detonators located in said second explosive means; a laser located in said proximal end of said casing; optical fibers connecting said laser to said first and second laser-driven slapper detonators; and optical switch means located in series with said optical fibers connected to said plurality of first laser-driven slapper detonators for blocking or passing light from said laser to said plurality of first laser-driven slapper detonators.

  12. Stratification of gallstone fragments: the key to more effective fragmentation.

    PubMed

    Alderfer, J T; Laufer, I; Wisniewski, F; Malet, P F

    1992-04-01

    During previous experiments with in vitro fragmentation in a simulated gallbladder, we noticed that stone fragments tended to stratify with the dust and smaller fragments settled to the dependent portion, while the larger fragments settled on top. We reviewed the oral cholecystogram (OCG) of 10 patients examined 6 months following gallstone lithotripsy. In all cases with adequate visualization of stone fragments, the stratification phenomenon was observed. We hypothesized that adjusting the shock wave focus to target on these large fragments would improve the efficiency of fragmentation. To test this hypothesis, we fragmented three matched pairs of gallstones in vitro. For each pair, the stones were removed from the same gallbladder and the stone weights of the two stones were within 10%. The smaller member of each pair was fragmented using the "old method" with the focus on the fragment line. The larger stone was fragmented with the "new method" with the focus in the acoustic shadow deep to the echogenic line caused by the dust and small fragments in the dependent portion. The distribution of fragments was analyzed by passing the fragments through a series of filters. With the new method of targeting, the proportion of fragments less than 1.5 mm was doubled while the fragments greater than 5 mm were eliminated. The new method of targeting, taking into account the stratification of stone fragments, produces more effective fragmentation and should lead to more rapid clearance of fragments from the gallbladder. PMID:10149180

  13. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, K.D.; Chu, T.J.; Pitt, W.G.

    1992-05-12

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through amino groups contained on the surface. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to the target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membranes may be reprobed numerous times. No Drawings

  14. Purple Level - 1 Milestone Review Committee I/O and Archive Follow-up Demonstration

    SciTech Connect

    Gary, M R

    2006-12-05

    On July 7th 2006, the Purple Level-1 Review Committee convened and was presented with evidence of the completion of Level-2 Milestone 461 (Deploy First Phase of I/O Infrastructure for Purple) which was performed in direct support of the Purple Level-1 milestone. This evidence included a short presentation and the formal documentation of milestone No.461 (see UCRL-TR-217288). Following the meeting, the Committee asked for the following additional evidence: (1) Set a speed measurement/goal/target assuming a number of files that the user needs to get into the archives. Then redo the benchmark using whatever tool(s) the labs prefer (HTAR, for example). Document how long the process takes. (2) Develop a test to read files back to confirm that what the user gets out of the archive is what the user put into the archive. This evidence has been collected and is presented here.

  15. Efficient Dye-Sensitized Solar Cells Using Red Turnip and Purple Wild Sicilian Prickly Pear Fruits

    PubMed Central

    Calogero, Giuseppe; Di Marco, Gaetano; Cazzanti, Silvia; Caramori, Stefano; Argazzi, Roberto; Di Carlo, Aldo; Bignozzi, Carlo Alberto

    2010-01-01

    Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO2 films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm2) and a high IPCE value (65% at λ = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm2, corresponding to a solar to electrical power conversion of 1.26%. PMID:20162014

  16. Purple top symptoms are associated with reduction of leaf cell death in phytoplasma-infected plants

    PubMed Central

    Himeno, Misako; Kitazawa, Yugo; Yoshida, Tetsuya; Maejima, Kensaku; Yamaji, Yasuyuki; Oshima, Kenro; Namba, Shigetou

    2014-01-01

    Plants exhibit a wide variety of disease symptoms in response to pathogen attack. In general, most plant symptoms are recognized as harmful effects on host plants, and little is known about positive aspects of symptoms for infected plants. Herein, we report the beneficial role of purple top symptoms, which are characteristic of phytoplasma-infected plants. First, by using plant mutants defective in anthocyanin biosynthesis, we demonstrated that anthocyanin accumulation is directly responsible for the purple top symptoms, and is associated with reduction of leaf cell death caused by phytoplasma infection. Furthermore, we revealed that phytoplasma infection led to significant activation of the anthocyanin biosynthetic pathway and dramatic accumulation of sucrose by about 1000-fold, which can activate the anthocyanin biosynthetic pathway. This is the first study to demonstrate the role and mechanism of the purple top symptoms in plant–phytoplasma interactions. PMID:24531261

  17. Biohydrogen production by purple non-sulfur bacteria Rhodobacter sphaeroides: Effect of low-intensity electromagnetic irradiation.

    PubMed

    Gabrielyan, Lilit; Sargsyan, Harutyun; Trchounian, Armen

    2016-09-01

    The present work was focused on the effects of low-intensity (the flux capacity was of 0.06mWcm(-2)) electromagnetic irradiation (EMI) of extremely high frequencies or millimeter waves on the growth and hydrogen (H2) photoproduction by purple non-sulfur bacteria Rhodobacter sphaeroides MDC6521 (from Armenian mineral springs). After exposure of R. sphaeroides, grown under anaerobic conditions upon illumination, to EMI (51.8GHz and 53.0GHz) for 15min an increase of specific growth rate by ~1.2-fold, in comparison with control (non-irradiated cells), was obtained. However, the effect of EMI depends on the duration of irradiation: the exposure elongation up to 60min caused the delay of the growth lag phase and the decrease specific growth rate by ~1.3-fold, indicating the bactericidal effect of EMI. H2 yield of the culture, irradiated by EMI for 15min, determined during 72h growth, was ~1.2-fold higher than H2 yield of control cells, whereas H2 production by cultures, irradiated by EMI for 60min was not observed during 72h growth. This difference in the effects of extremely high frequency EMI indicates a direct effect of radiation on the membrane transfer and the enzymes of these bacteria. Moreover, EMI increased DCCD-inhibited H(+) fluxes across the bacterial membrane and DCCD-sensitive ATPase activity of membrane vesicles, indicating that the proton FoF1-ATPase is presumably a basic target for extremely high frequency EMI related to H2 production by cultures. PMID:27479839

  18. Fragment capture device

    DOEpatents

    Payne, Lloyd R.; Cole, David L.

    2010-03-30

    A fragment capture device for use in explosive containment. The device comprises an assembly of at least two rows of bars positioned to eliminate line-of-sight trajectories between the generation point of fragments and a surrounding containment vessel or asset. The device comprises an array of at least two rows of bars, wherein each row is staggered with respect to the adjacent row, and wherein a lateral dimension of each bar and a relative position of each bar in combination provides blockage of a straight-line passage of a solid fragment through the adjacent rows of bars, wherein a generation point of the solid fragment is located within a cavity at least partially enclosed by the array of bars.

  19. Identification and Characterization of DcUSAGT1, a UDP-Glucose: Sinapic Acid Glucosyltransferase from Purple Carrot Taproots.

    PubMed

    Chen, Yi-Yun; Xu, Zhi-Sheng; Xiong, Ai-Sheng

    2016-01-01

    Purple carrots accumulate abundant cyanidin-based anthocyanins in taproots. UDP-glucose: sinapic acid glucosyltransferase (USAGT) can transfer the glucose moiety to the carboxyl group of sinapic acid thereby forming the ester bond between the carboxyl-C and the C1 of glucose (1-O-sinapoylglucose). 1-O-sinapoylglucose can serve as an acyl donor in acylation of anthocyanins and generate cyanidin 3-xylosyl (sinapoylglucosyl) galactoside in purple carrots. This final product helps stabilize the accumulation of anthocyanins. In this study, a gene named DcUSAGT1 encoding USAGT was cloned from 'Deep purple' carrot taproots. Enzymatic activity was determined using high performance liquid chromatography (HPLC). The optimal temperature and pH value were 30°C and 7.0, respectively. Kinetic analysis suggested a Km (sinapic acid) of 0.59 mM. Expression profiles of DcUSAGT1 showed high expression levels in the taproots of all the three purple carrot cultivars but low expression levels in those of non-purple carrot cultivars. The USAGT activity of different carrots in vitro indicated that crude enzyme extracted from the purple carrot taproots rather than non-purple carrot taproots exhibited USAGT activity. These results indicated that DcUSAGT1 may influence anthocyanin biosynthesis of purple carrot taproots. PMID:27171142

  20. Transcriptional activation of a MYB gene controls the tissue-specific anthocyanin accumulation in a purple cauliflower mutant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonoids such as anthocyanins possess significant health benefits to humans and play important physiological roles in plants. An interesting Purple gene mutation in cauliflower confers an abnormal pattern of anthocyanin accumulation, giving intense purple color in very young leaves, curds, and see...

  1. [Characteristics of Adsorption Leaching and Influencing Factors of Dimethyl Phthalate in Purple Soil].

    PubMed

    Wang, Qiang; Song, Jiao-yan; Zeng, Wei; Wang, Fa

    2016-02-15

    The typical soil-purple soil in Three Gorges Reservoir was the tested soil, the characteristics of adsorption leaching of dimethyl phthalate (DMP) in contaminated water by the soil, and the influencing factors in the process were conducted using soil column leaching experiment. The results showed that the parabolic equation was the best equation describing adsorption kinetics of DMP by soils. The concentration of DMP in the leaching solution had significant effect on the adsorption amounts of DMP. With the increasing concentration of DMP in the leaching solution, the adsorption capacities of DMP by purple soil increased linearly. The ionic strength and pH in leaching solution had significant effects on adsorption of DMP. On the whole, increasing of the ionic strength restrained the adsorption. The adsorption amounts at pH 5.0-7.0 were more than those under other pH condition. The addition of exogenous organic matter (OM) in purple soil increased the adsorption amount of DMP by purple soil. However, the adsorption amount was less than those with other addition amounts of exogenous OM when the addition of exogenous OM was too high (> or = 30 g x kg(-1)). The addition of surfactant sodium dodecylbenzene sulfonic acid (SDBS) in purple soil increased the adsorption amount of DMP by purple soil. The adsorption amount was maximal when the addition amount of SDBS was 50 mg x kg(-1). However, the adsorption amounts decreased with increasing addition amounts of SDBS although the adsorption amounts were still more than that of the control group, and the adsorption amount was almost equal to that of the control group when the addition amount of SDBS was 800 mg x kg(-1). Continuous leaching time affected the vertical distribution of DMP in the soil column. When the leaching time was shorter, the upper soil column adsorbed more DMP, while the DMP concentrations in upper and lower soil columns became similar with the extension of leaching time. PMID:27363166

  2. [Chemical composition and chromaticity characteristic of purple-gold glaze of Jingdezhen imperial kiln].

    PubMed

    Wu, Jun-Ming; Li, Qi-Jiang; Zhang, Mao-Lin; Ding, Yin-Zhong; Cao, Jian-Wen; Liu, Xiao-Jing

    2014-03-01

    Color glaze is one of the four famous traditional ceramics of Jingdezhen, especially for the products from Ming and Qing Dynasties' official kilns which have rich connotation of technology and culture. The chemical composition and chromaticity characteristic of glaze and body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties' official kilns were analyzed by energy dispersive X ray fluorescence (EDXRF) and colorimeter. Preliminary study on the composition, formula and chromaticity characteristic of glaze of purple-gold glaze samples of different period was carried out and the intrinsic causes of ifferences were discussed. The result shows that the concentration of magnesium and calcium in purple-gold glaze is different from the other glazes in Jingdezhen in the same time, probably due to the addition of auburn or brown limestone which is rich in magnesium. The purple-gold glaze sample of Ming Dynasty is darker chiefly because the concentration of magnesium and calcium is higher than the sample of Ming Dynasty which led to iron crystal separated, reducing the brightness and glossiness of glaze. In addition, the body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties' official kilns has the characteristics of high silicon and low aluminum and the molar ratio of silicon to aluminum of samples from Ming Dynasty to Qing Dynasty declined, showing that the concentration of kaolin of sample's body of Ming dynasty was increased. The result of this experiment fill deficiency in the ceramic science and technology research in our country about purple-gold glaze from Ming and Qing Dynasties' official kilns and provides scientific material for comprehensive understanding of porcelain marking technology and intrinsic value of Jingdezhen official kiln. PMID:25208422

  3. Fracture tooth fragment reattachment

    PubMed Central

    Maitin, Nitin; Maitin, Shipra Nangalia; Rastogi, Khushboo; Bhushan, Rajarshi

    2013-01-01

    Coronal fractures of the anterior teeth are a common form of dental trauma and its sequelae may impair the establishment and accomplishment of an adequate treatment plan. Among the various treatment options, reattachment of a crown fragment is a conservative treatment that should be considered for crown fractures of anterior teeth. This clinical case reports the management of two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment using glass-fibre-reinforced composite post. PMID:23853012

  4. Green tea from purple leaf coloured tea clones in Kenya- their quality characteristics.

    PubMed

    Kilel, E C; Faraj, A K; Wanyoko, J K; Wachira, F N; Mwingirwa, V

    2013-11-15

    The Kenyan tea industry wishes to diversify its tea products, and in line with this, anthocyanin - rich teas were developed at the Tea Research Foundation of Kenya. These teas have purple-coloured leaves and the green colour is masked. In total, 12 accessions of the purple leaf coloured teas and 2 standard tea varieties were studied. Clones Hanlu and Yabukita are Chinese and Japanese tea varieties, respectively, known for good green tea, and they were used as reference standards. Little if any research had been done to characterize the quality of these purple leaf coloured teas and this study investigated their total polyphenols (TPP), catechins, caffeine, gallic acid and theanine. These are the major green tea quality parameters. Results showed that the new Kenyan tea clones had higher total polyphenols than had the reference standard tea varieties, which had 17.2% and 19.7% while the lowest among the Kenyan clones was 20.8%. On catechin quality index, K-purple and TRFK 91/1 showed high index values of 15.9 and 13.3, respectively, while clones TRFK 83/1 and 73/5 showed low index values of 0.74 and 1.0, respectively. Hanlu had the highest caffeine level with 2.42% while clones TRFK KS 3, TRFK KS 2 and TRFK 83/1 had relatively high caffeine levels among the purple leaf coloured teas, with 2.33%, 2.22% and 2.21%, respectively. Clone TRFK 73/5 had the lowest caffeine content, with 1.16%. Theanine analysis showed that most purple leaf coloured teas had more theanine than had the reference standard clones, except TRFK 83/1 and K-purple, which were lower than the reference standard clones. The implication of the green tea chemical quality parameters is also discussed. It is concluded that all the studied clones/varieties have above the minimum 14% of total polyphenols. Clones K-purple and TRFK 91/1 showed high green tea quality indices with the latter doubling with high levels of theanine; hence its highly recommended for green tea manufacture. PMID:23790846

  5. DNA sequencing using fluorescence background electroblotting membrane

    DOEpatents

    Caldwell, Karin D.; Chu, Tun-Jen; Pitt, William G.

    1992-01-01

    A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof. The DNA fragments chemically bound to the membrane are subjected to hybridization probing with a tagged probe specific to the sequence of the DNA fragments. The tagging may be by either fluorophores or radioisotopes. The tagged probes hybridized to said target DNA fragments are detected and read by laser induced fluorescence detection or autoradiograms. The use of aminated low fluorescent background membranes allows the use of fluorescent detection and reading even when the available amount of DNA to be sequenced is small. The DNA bound to the membrances may be reprobed numerous times.

  6. Manipulation of Developing Juvenile Structures in Purple Sea Urchins (Strongylocentrotus purpuratus) by Morpholino Injection into Late Stage Larvae

    PubMed Central

    2014-01-01

    Sea urchins have been used as experimental organisms for developmental biology for over a century. Yet, as is the case for many other marine invertebrates, understanding the development of the juveniles and adults has lagged far behind that of their embryos and larvae. The reasons for this are, in large part, due to the difficulty of experimentally manipulating juvenile development. Here we develop and validate a technique for injecting compounds into juvenile rudiments of the purple sea urchin, Strongylocentrotus purpuratus. We first document the distribution of rhodaminated dextran injected into different compartments of the juvenile rudiment of sea urchin larvae. Then, to test the potential of this technique to manipulate development, we injected Vivo-Morpholinos (vMOs) designed to knock down p58b and p16, two proteins involved in the elongation of S. purpuratus larval skeleton. Rudiments injected with these vMOs showed a delay in the growth of some juvenile skeletal elements relative to controls. These data provide the first evidence that vMOs, which are designed to cross cell membranes, can be used to transiently manipulate gene function in later developmental stages in sea urchins. We therefore propose that injection of vMOs into juvenile rudiments, as shown here, is a viable approach to testing hypotheses about gene function during development, including metamorphosis. PMID:25436992

  7. Thiocapsa imhoffii, sp. nov., an alkaliphilic purple sulfur bacterium of the family Chromatiaceae from Soap Lake, Washington (USA).

    PubMed

    Asao, Marie; Takaichi, Shinichi; Madigan, Michael T

    2007-12-01

    An alkaliphilic purple sulfur bacterium, strain SC5, was isolated from Soap Lake, a soda lake located in east central Washington state (USA). Cells of strain SC5 were gram-negative, non-motile, and non-gas vesiculate cocci, often observed in pairs or tetrads. In the presence of sulfide, elemental sulfur was deposited internally. Liquid cultures were pink to rose red in color. Cells contained bacteriochlorophyll a and spirilloxanthin as major photosynthetic pigments. Internal photosynthetic membranes were of the vesicular type. Optimal growth of strain SC5 occurred in the absence of NaCl (range 0-4%), pH 8.5 (range pH 7.5-9.5), and 32 degrees C. Photoheterotrophic growth occurred in the presence of sulfide or thiosulfate with only a limited number of organic carbon sources. Growth factors were not required, and cells could fix N2. Dark, microaerobic growth occurred in the presence of both an organic carbon source and thiosulfate. Sulfide and thiosulfate served as electron donors for photoautotrophy, which required elevated levels of CO2. Phylogenetic analysis placed strain SC5 basal to the clade of the genus Thiocapsa in the family Chromatiaceae with a 96.7% sequence similarity to its closest relative, Thiocapsa roseopersicina strain 1711T (DSM217T). The unique assemblage of physiological and phylogenetic properties of strain SC5 defines it as a new species of the genus Thiocapsa, and we describe strain SC5 herein as Tca. imhoffii, sp. nov. PMID:17661016

  8. Anti-Escherichia coli O157:H7 properties of purple prairie clover and sainfoin condensed tannins.

    PubMed

    Liu, Xiu-Li; Hao, Yong-Qing; Jin, Long; Xu, Zhong-Jun; McAllister, Tim A; Wang, Yuxi

    2013-01-01

    Condensed tannins (CT) from purple prairie clover (PPC; Dalea purpurea Vent.) and sainfoin (SF; Onobrychis viciifolia) were assessed for anti-Escherichia coli activity by comparing their ability to react with proteins and liposome, cause cell aggregation, and alter outer membrane (OM) morphology and permeability. The PPC CT had greater (P < 0.01) protein-precipitating capacity than SF CT using either bovine serum albumin or ribulose 1,5-disphosphate carboxylase as model proteins. Minimum inhibitory concentration of PPC CT for two strains of E. coli and five strains of E. coli O157:H7 was four to six times lower than that of SF CT. E. coli exposed to 10 µg/mL of both CT had higher (P < 0.05) OM permeability than controls and was greater (P < 0.05) for PPC than for SF CT. Addition of both CT at 50 and 200 µg/mL caused cell aggregation which was more evident (P < 0.05) for PPC than for SF CT. Transmission electron microscopy showed electron dense material on the cell surface when cells were exposed to 50 µg/mL of PPC CT. The greater anti-E. coli activity of PPC than SF CT was due to its enhanced ability to precipitate protein that increased OM permeability and promoted cell aggregation. PMID:23396143

  9. [Rhodobaculum claviforme gen. nov., sp. nov., a New Alkaliphilic Nonsulfur Purple Bacterium].

    PubMed

    Bryantseva, I A; Gaisin, V A; Gorlenko, V M

    2015-01-01

    Two alkaliphilic strains of nonsulfur purple bacteria (NPB), B7-4 and B8-2, were isolated from southeast Siberia moderately saline alkaline steppe lakes with pH values above 9.0. The isolates were motile, polymorphous cells (from short rods to long spindly cells) 2.0-3.2 x 9.6-20.0 μm. Intracellular membranes of vesicular type were mostly located at the cell periphery. The microorganisms contained bacteriochlorophyll a and carotenoids of the spheroidene and spirilloxanthin series. The photosynthetic apparatus was represented by LH2 and LH1 light-harvesting complexes. In the presence of organic compounds, the strains grew aerobically in the dark or anaerobically in the light. Capacity for photo- and chemoautotrophic growth was not detected. The cbbl gene encoding RuBisCO was not revealed. Optimal growth of both strains occurred at 2% NaCl (range from 0.5 to 4%), pH 8.0-8.8 (range from 7.5 to 9.7), and 25-35 degrees C. The DNA G+C content was 67.6-69.8 mol %. Pairwise comparison of the nucleotides of the 16S rRNA genes revealed that strains B7-4 and B8-2 belonged to the same species (99.9% homology) and were most closely related to the aerobic alkaliphilic bacteriochlorophyll a-containing anoxygenic phototrophic bacterium (APB) Roseibacula alcaliphilum De (95.2%) and to NPB strains Rhodobaca barguzinensis VKM B-2406(T) (94.2%) and Rbc. bogoriensis LBB1(T) (93.9%). The isolates were closely related to the NPB Rhodobacter veldkampii DSM 11550(T) (94.8%) and to aerobic bacteriochlorophyll a-containing bacteria Roseinatronobacter monicus ROS 35(T) and Roseicitreum antarcticul ZS2-28(T) (93.5 and 93.9%, respectively). New strains were described as a new NPB genus and species of the family Rhodobacteriaceae, Rhodobaculum claviforme gen. nov., sp. nov., with B7-4(T) (VKM B-2708, LMG 28126) as the type strain. PMID:26263629

  10. Purple Prairie Clover (Dalea purpurea Vent) Reduces Fecal Shedding of Escherichia coli in Pastured Cattle.

    PubMed

    Jin, L; Wang, Y; Iwaasa, A D; Li, Y; Xu, Z; Schellenberg, M P; Liu, X L; McAllister, T A; Stanford, K

    2015-08-01

    A 3-year (2009 to 2011) grazing study was conducted to assess the effects of purple prairie clover (PPC; Dalea purpurea Vent) on fecal shedding of total Escherichia coli in cattle. Three pasture types were used in the experiment: bromegrass (Check), mixed cool season grasses with PPC (Simple), and mixed cool and warm grasses with PPC (Complex). Pastures were rotationally grazed during a summer and fall grazing period. PPC was grazed in summer at the vegetative or early flower stage and at the flower or early seed stage during the fall. Fecal samples were collected for enumeration of E. coli and chemical analyses. Forage samples were collected throughout grazing for analysis. Condensed tannins (CT) were only detected in Simple and Complex pastures that contained PPC, with higher concentrations found in the fall than in the summer. Fecal counts of E. coli in cattle grazing Simple and Complex pastures linearly decreased (P < 0.05) over summer to fall in all 3 years, an outcome not observed in cattle grazing the Check pasture. Across the three grazing seasons, fecal E. coli was lower (P < 0.05) in cattle grazing Simple and Complex pastures than in those grazing the Check pasture during the fall. During the fall, feces collected from cattle grazing the Check pasture had higher (P < 0.05) values for pH, N, NH3-N, total volatile fatty acids, and branched-chain volatile fatty acids, but a lower (P < 0.05) acetate:propionate ratio than feces collected from cattle grazing Simple or Complex pastures. In a second experiment, two strains of E. coli were cultured in M9 medium containing 25 to 200 μg/ml of PPC CT. Growth of E. coli was linearly (P < 0.01) reduced by increasing levels of PPC CT. Scanning electron micrographs showed electron-dense filamentous material associated with the outer membrane of E. coli cells exposed to CT. Incorporation of PPC into forage reduced the fecal shedding of E. coli from grazing cattle, likely due to the anti-E. coli properties of PPC CT. PMID

  11. Heavy fragment radioactivities

    SciTech Connect

    Price, P.B.

    1987-12-10

    This recently discovered mode of radioactive decay, like alpha decay and spontaneous fission, is believed to involve tunneling through the deformation-energy barrier between a very heavy nucleus and two separated fragments the sum of whose masses is less than the mass of the parent nucleus. In all known cases the heavier of the two fragments is close to doubly magic /sup 208/Pb, and the lighter fragment has even Z. Four isotopes of Ra are known to emit /sup 14/C nuclei; several isotopes of U as well as /sup 230/Th and /sup 231/Pa emit Ne nuclei; and /sup 234/U exhibits four hadronic decay modes: alpha decay, spontaneous fission, Ne decay and Mg decay.

  12. Fragment screening: an introduction.

    PubMed

    Leach, Andrew R; Hann, Michael M; Burrows, Jeremy N; Griffen, Ed J

    2006-09-01

    There are clearly many different philosophies associated with adapting fragment screening into mainstream Drug Discovery Lead Generation strategies. Scientists at Astex, for instance, focus entirely on strategies involving use of X-ray crystallography and NMR. However, AstraZeneca uses a number of different fragment screening strategies. One approach is to screen a 2000 compound fragment set (with close to "lead-like" complexity) at 100 microM in parallel with every HTS such that the data are obtained on the entire screening collection at 10 microM plus the extra samples at 100 microM; this provides valuable compound potency data in a concentration range that is usually unexplored. The fragments are then screen-specific "privileged structures" that can be searched for in the rest of the HTS output and other databases as well as having synthesis follow-up. A typical workflow for a fragment screen within AstraZeneca is shown below (Figure 24) and highlights the desirability (particularly when screening >100 microM) for NMR and X-ray information to validate weak hits and give information on how to optimise them. In this chapter, we have provided an introduction to the theoretical and practical issues associated with the use of fragment methods and lead-likeness. Fragment-based approaches are still in an early stage of development and are just one of many interrelated techniques that are now used to identify novel lead compounds for drug development. Fragment based screening has some advantages, but like every other drug hunting strategy will not be universally applicable. There are in particular some practical challenges associated with fragment screening that relate to the generally lower level of potency that such compounds initially possess. Considerable synthetic effort has to be applied for post-fragment screening to build the sort of potency that would be expected to be found from a traditional HTS. However, if there are no low-hanging fruit in a screening

  13. Migration and control of purple loosestrife (Lythrum salicaria L.) along highway corridors

    USGS Publications Warehouse

    Wilcox, Douglas A.

    1989-01-01

    The east-west density gradient and the pattern and mode of migration of the wetland exotic, purple loosestrife (Lythrum salicaria L.), were assessed in a survey of populations along the New York State Thruway from Albany to Buffalo to determine if the highway corridor contributed to the spread of this species. During the peak flowering season of late July to early August, individual colonies of purple loosestrife were identified and categorized into three size classes in parallel belt transects consisting of the median strip and highway rights-of-way on the north and south sides of the road. Data were also collected on the presence of colonies adjacent to the corridor and on highway drainage patterns. Although a distinct east-west density gradient existed in the corridor, it corresponded to the gradient on adjacent lands and was greatly influenced by a major infestation at Montezuma National Wildlife Refuge. The disturbed highway corridor served as a migration route for purple loosestrife, but topographic features dictated that this migration was a short-distance rather than long-distance process. Ditch and culvert drainage patterns increased the ability of purple loosestrife to migrate to new wetland sites. Management strategies proposed to reduce the spread of this wetland threat include minimizing disturbance, pulling by hand, spraying with glyphosate, disking, and mowing.

  14. Increased purple nutsedge (Cyperus rotundus) tuber sprouting with diurnally fluctuating temperatures.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple nutsedge is among the most troublesome weeds of vegetables in the Southeast US and a substantial impediment in the search for methyl bromide alternatives. Greater understanding of the environmental cues that regulate tuber sprouting may assist in improved nutsedge management. Experiments we...

  15. Genome Sequence of Marichromatium gracile YL-28, a Purple Sulfur Bacterium with Bioremediation Potential

    PubMed Central

    Zhang, Xiaobo; Zhao, Chungui; Hong, Xuan

    2016-01-01

    The draft genome sequence of Marichromatium gracile YL-28 contains 3,840,251 bp, with a G+C content of 68.84%. The annotated genome sequence provides the genetic basis for revealing its role as a purple sulfur bacterium in the harvesting of energy and the development of bioremediation applications. PMID:27151789

  16. 50 CFR 21.45 - Depredation order for depredating purple gallinules in Louisiana.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Control of Depredating and Otherwise Injurious Birds § 21.45 Depredation order for depredating purple gallinules in Louisiana... be necessary to bury or otherwise destroy the carcasses of such birds is permitted: Provided,...

  17. 50 CFR 21.45 - Depredation order for depredating purple gallinules in Louisiana.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Control of Depredating and Otherwise Injurious Birds § 21.45 Depredation order for depredating purple gallinules in Louisiana... be necessary to bury or otherwise destroy the carcasses of such birds is permitted: Provided,...

  18. Purple Computational Environment With Mappings to ACE Requirements for the General Availability User Environment Capabilities

    SciTech Connect

    Barney, B; Shuler, J

    2006-08-21

    Purple is an Advanced Simulation and Computing (ASC) funded massively parallel supercomputer located at Lawrence Livermore National Laboratory (LLNL). The Purple Computational Environment documents the capabilities and the environment provided for the FY06 LLNL Level 1 General Availability Milestone. This document describes specific capabilities, tools, and procedures to support both local and remote users. The model is focused on the needs of the ASC user working in the secure computing environments at Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratories, but also documents needs of the LLNL and Alliance users working in the unclassified environment. Additionally, the Purple Computational Environment maps the provided capabilities to the Trilab ASC Computing Environment (ACE) Version 8.0 requirements. The ACE requirements reflect the high performance computing requirements for the General Availability user environment capabilities of the ASC community. Appendix A lists these requirements and includes a description of ACE requirements met and those requirements that are not met for each section of this document. The Purple Computing Environment, along with the ACE mappings, has been issued and reviewed throughout the Tri-lab community.

  19. Genetic mapping of resistance to purple seed stain in PI 80837 soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple seed stain (PSS) of soybean caused by Cercospora kikuchii is an important disease that reduces market grade and can affect seed germination and vigor. A single dominant gene was shown to confer PSS resistance in PI 80837. The objective of this research was to map the PSS resistance gene in P...

  20. Susceptibility of Different Potato Cultivars to Purple Top Disease in the Columbia Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, Columbia Basin potato growers in Washington and Oregon have experienced serious outbreaks of potato purple top disease that caused significant yield losses and a reduction in tuber quality. The beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma is the causal agent of the di...

  1. Use of purple durum wheat to produce naturally functional fresh and dry pasta.

    PubMed

    Ficco, Donatella Bianca Maria; De Simone, Vanessa; De Leonardis, Anna Maria; Giovanniello, Valentina; Del Nobile, Matteo Alessandro; Padalino, Lucia; Lecce, Lucia; Borrelli, Grazia Maria; De Vita, Pasquale

    2016-08-15

    In this study, the effects of different milling procedures (roller-milling vs. stone-milling) and pasta processing (fresh vs. dried spaghetti), and cooking on the antioxidant components and sensory properties of purple durum wheat were investigated. Milling and pasta processing were performed using one purple and one conventional non-pigmented durum wheat genotypes, and the end-products were compared with commercial pasta. The results show that the stone milling process preserved more compounds with high health value (total fibre and carotenoids, and in the purple genotype, also anthocyanins) compared to roller-milling. The drying process significantly (p<0.05) reduced the content of anthocyanins (21.42 μg/g vs. 46.32 μg/g) and carotenoids (3.77 μg/g vs. 4.04 μg/g) with respect to the pasteurisation process involved in fresh pasta production. The sensory properties of pasta from the purple genotype did not significantly differ from commercial wholemeal pasta, and its in vitro glycemic index was even lower. Thus, it is possible to consider this genetic material as a good ingredient for the production of functional foods from cereals naturally rich in bioactive compounds. PMID:27006230

  2. Susceptibility of Different Potato Plant Growth Stages to Purple Top Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, potato growers in the Columbia Basin of Washington and Oregon have experienced outbreaks of potato purple top disease that have caused significant yield losses and reductions in tuber quality. It was determined that the beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma is ...

  3. Glyphosate Hinders Purple Nutsedge (Cyperus rotundus) and Yellow Nutsedge (Cyperus esculentus) Tuber Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple and yellow nutsedge are among the most troublesome weeds of cucurbit and fruiting vegetable production in the Southeast US. The phase-out of methyl bromide will necessitate alternative management options that target tubers, the primary means of nutsedge reproduction. Greenhouse studies wer...

  4. Identification of soybean purple acid phosphatase genes and their expression responses to phosphorus availability and symbiosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Aims Purple acid phosphatases (PAPs) are members of the metallo-phosphoesterase family and have been known to play important roles in phosphorus (P) acquisition and recycling in plants. Low P availability is a major constraint to growth and production of soybean, Glycine max. Comparat...

  5. Development of a frozen yogurt fortified with a nano-emulsion containing purple rice bran oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to develop and evaluate a frozen yogurt (FY) fortified with a nano-emulsion containing purple rice bran oil (NPRBO). A nano-emulsion with a droplet size range of 150-300 nm was produced by sonication followed by ultra-shear homogenization. The nano-emulsion was mi...

  6. Genome Sequence of Marichromatium gracile YL-28, a Purple Sulfur Bacterium with Bioremediation Potential.

    PubMed

    Zhang, Xiaobo; Zhao, Chungui; Hong, Xuan; Chen, Shicheng; Yang, Suping

    2016-01-01

    The draft genome sequence of Marichromatium gracile YL-28 contains 3,840,251 bp, with a G+C content of 68.84%. The annotated genome sequence provides the genetic basis for revealing its role as a purple sulfur bacterium in the harvesting of energy and the development of bioremediation applications. PMID:27151789

  7. Anthocyanin content, antioxidant activity and selected physical properties of flowable purple-fleshed sweetpotato purees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With high levels of polyphenolic compounds, purple-fleshed sweetpotatoes (PFSP) have been utilized as a healthy food commodity and source of natural food colorants in Asia. In the sweetpotato industry of the United States, there are growing interests in exploring these market opportunities for PFSP...

  8. Evaluation of maturity group III soybean lines for resistance to purple seed stain in Mississippi, 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple seed stain (PSS) of soybean is an important disease caused by Cercospora kikuchii. PSS reduces seed quality and market grade, affects seed germination and vigor, and has been reported wherever soybeans are grown worldwide. In 2009, PSS caused 6.4 million bushels of yield losses in 16 southern...

  9. Role of gibberellic acid in tomato defense response to potato purple top phytoplasma infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection of tomato by potato purple top (PPT) phytoplasma causes disruption of gibberellin (GA) homeostasis in the plant host. Such pathologically-induced GA deficiency can be partially reversed by exogenous application of GA. The present study was designed to explore the role of GA in tomato defe...

  10. Fire and nitrogen fertilization effects on Purple Threeawn in vitro fermentation and gas production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple threeawn (Aristida purpurea) is a native perennial bunchgrass with poor forage quality. The grass often dominates sites where soils have been disturbed and persists with continued severe grazing of preferred species due to livestock avoidance of threeawn. Nitrogen fertilization and fire hav...

  11. Effect of the Purple Corn Beverage “Chicha Morada” in Composite Resin during Dental Bleaching

    PubMed Central

    Acuña, Eric Dario; Delgado-Cotrina, Leyla; Rumiche, Francisco Aurelio

    2016-01-01

    During dental bleaching the staining potential of the surface would increase. This study aims to evaluate the staining susceptibility of one bleached composite resin after the exposure to three different beverages: Peruvian purple corn based beverage (chicha morada), green tea, and distilled water. Thirty disk-shaped specimens of one nanofill composite resin were prepared. The specimens were then divided into six groups (n = 5): purple corn (P), purple corn + bleaching (PB), green tea (T), green tea + bleaching (TB), distilled water (W), and distilled water + bleaching (WB). In groups that received bleaching, two sessions of bleaching with 35% hydrogen peroxide were done. Following bleaching, specimens were exposed to each liquid thirty minutes daily. Color was measured with a digital spectrophotometer. For statistical analysis, color measurement differences between the obtained results were used: during bleaching, after bleaching, and during + after bleaching. Two-way ANOVA was used to compare the color changes in the resins of all groups (p < 0.05). We conclude that all the evaluated beverages produced changes of color in the composite resin regardless of the bleaching procedure. However, purple corn was the only beverage that caused a perceptible color change (ΔE > 3.3). PMID:27034897

  12. Antidiabetic Potential of Purple and Red Rice (Oryza sativa L.) Bran Extracts.

    PubMed

    Boue, Stephen M; Daigle, Kim W; Chen, Ming-Hsuan; Cao, Heping; Heiman, Mark L

    2016-07-01

    Pigmented rice contains anthocyanins and proanthocyanidins that are concentrated in the bran layer. In this study, we determined the phenolic, flavonoid, anthocyanin, and proanthocyanidin content of five rice bran (1 brown, 2 red, and 2 purple) extracts. Each bran extract was evaluated for inhibitory effects on α-amylase and α-glucosidase activity, two key glucosidases required for starch digestion in humans. All purple and red bran extracts inhibited α-glucosidase activity, however only the red rice bran extracts inhibited α-amylase activity. Additionally, each bran extract was examined for their ability to stimulate glucose uptake in 3T3-L1 adipocytes, a key function in glucose homeostasis. Basal glucose uptake was increased between 2.3- and 2.7-fold by exposure to the red bran extracts, and between 1.9- and 3.1-fold by exposure to the purple bran extracts. In red rice bran, the highest enzyme inhibition and glucose uptake was observed with a proanthocyanidin-enriched fraction. Both IITA red bran and IAC purple bran increased expression of GLUT1 and GLUT4 mRNA, and genes encoding insulin-signaling pathway proteins. PMID:27285791

  13. 50 CFR 21.45 - Depredation order for depredating purple gallinules in Louisiana.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Control of Depredating and Otherwise Injurious Birds § 21.45 Depredation order for depredating purple gallinules in Louisiana... be necessary to bury or otherwise destroy the carcasses of such birds is permitted: Provided,...

  14. 50 CFR 21.45 - Depredation order for depredating purple gallinules in Louisiana.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD PERMITS Control of Depredating and Otherwise Injurious Birds § 21.45 Depredation order for depredating purple gallinules in Louisiana... be necessary to bury or otherwise destroy the carcasses of such birds is permitted: Provided,...

  15. Processing conditions for producing french fries from purple-fleshed sweetpotatoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of processing conditions and cooking methods on the physical quality, anthocyanin content and sensory attributes of frozen purple-fleshed sweetpotato (PFSP) French fries were investigated. PFSP strips were blanched in boiling water for 0, 5 or 10 min, par-fried at 180ºC for 0 or 1 min an...

  16. A View from the Mountain Top: The Purple Mountain Observatory Library, China

    ERIC Educational Resources Information Center

    Zhang, Jian

    2012-01-01

    This paper discusses the author's experience directing the Purple Mountain Observatory Library, Chinese Academy of Sciences (CAS) in Nanjing, China. Routine collection development, management and preservation issues are described, and the unique challenges and opportunities involved in operating a remote observatory library are highlighted.

  17. Potato purple top phytoplasma-induced disruption of gibberellin homeostasis in tomato plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytoplasmas are phloem-inhabiting, cell wall-less bacteria that cause numerous plant diseases worldwide. Plants infected by phytoplasmas often exhibit various symptoms indicative of hormonal imbalance. In the present study, we investigated the effects of potato purple top (PPT) phytoplasma infect...

  18. Transcriptome sequencing of purple petal spot region in tree peony reveals differentially expressed anthocyanin structural genes

    PubMed Central

    Zhang, Yanzhao; Cheng, Yanwei; Ya, Huiyuan; Xu, Shuzhen; Han, Jianming

    2015-01-01

    The pigmented cells in defined region of a petal constitute the petal spots. Petal spots attract pollinators and are found in many angiosperm families. Several cultivars of tree peony contain a single red or purple spot at the base of petal that makes the flower more attractive for the ornamental market. So far, the understanding of the molecular mechanism of spot formation is inadequate. In this study, we sequenced the transcriptome of the purple spot and the white non-spot of tree peony flower. We assembled and annotated 67,892 unigenes. Comparative analyses of the two transcriptomes showed 1,573 differentially expressed genes, among which 933 were up-regulated, and 640 were down-regulated in the purple spot. Subsequently, we examined four anthocyanin structural genes, including PsCHS, PsF3′H, PsDFR, and PsANS, which expressed at a significantly higher level in the purple spot than in the white non-spot. We further validated the digital expression data using quantitative real-time PCR. Our result uncovered transcriptome variance between the spot and non-spot of tree peony flower, and revealed that the co-expression of four anthocyanin structural genes was responsible for spot pigment in tree peony. The data will further help to unravel the genetic mechanism of peony flower spot formation. PMID:26583029

  19. Alexandrite-like effect in purple flowers analyzed with newly devised round RGB diagram.

    PubMed

    Kasajima, Ichiro

    2016-01-01

    The gemstone alexandrite is known for its feature to change color depending on the spectral quality of the incident light. Thus, the stone looks green when illuminated by white LED light but looks red when illuminated by incandescent light. This effect (alexandrite effect) is caused by a special relationship between the spectral quality of the incident light and the absorbance spectrum of the stone. Here we report an alexandrite-like effect in the petals of torenia and cyclamen flowers. These flowers are purple in sunlight but magenta (reddish) in incandescent light, and violet (bluish purple) in white LED light. The m-n, triangle and round diagrams are devised to calculate the colors of visible light spectra, based on the RGB color-matching function. Using these calculations, the alexandrite-like effect in purple flowers was successfully analyzed in terms of the interaction between the incident light spectrum and the absorbance spectrum of their purple anthocyanin. This analysis allows both logical and intuitive understanding of the colors exhibited by any object showing alexandrite-like properties. PMID:27404088

  20. Assessing the Impact of Purple Top Disease Pathogen on Potatoes in the Columbia Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, Columbia Basin potato growers in Washington and Oregon have experienced serious outbreaks of potato purple top disease that caused significant yield losses and a reduction in tuber quality. The beet leafhopper-transmitted virescence agent (BLTVA) phytoplasma is the causal agent of the di...

  1. Potato Purple Top Disease and Beet Leafhoppers in the Columbia Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recent epidemic of purple top disease of potato occurred in the Columbia Basin of Washington and Oregon and caused significant yield losses to potato fields and reduction in tuber quality. Symptoms in affected potato plants include an upward rolling of the top leaves with reddish or purplish disco...

  2. Continuous flow microwave-assisted processing and aseptic packaging of purple-fleshed sweetpotato purees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pumpable purees from purple-flesh sweetpotatoes (PFSP) were subjected to microwave heating using a 915 MHz continuous flow system, followed by aseptic packaging in flexible containers to obtain a shelf-stable product. Initial test runs were conducted using a 5 kW microwave unit to measure dielectr...

  3. Application of Polyacrylamide to Reduce Phosphorus Losses from Chinese Purple Soil: A Laboratory and Field Investigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of anionic polyacrylamide (PAM) for the control of phosphorus (P) losses from a steeply sloping Chinese purple soil was studied in both a laboratory soil column experiment and a field experiment. The results showed that PAM has an important inhibitory impact on vertical P transport i...

  4. 75 FR 48896 - Endangered and Threatened Wildlife and Plants; Removing the Tennessee Purple Coneflower From the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-12

    ... notice in the Federal Register (40 FR 27873) accepting the Smithsonian report as a petition to list taxa... those plants. Echinacea tennesseensis was included in that report (40 FR 27880). Tennessee purple.... On June 16, 1976, we published a proposed rule in the Federal Register (41 FR 24524) to...

  5. Peter Wilcox: A new purple-skin, yellow flesh fresh market potato cultivar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peter Wilcox is a new, medium-maturing, purple-skin, yellow-flesh potato cultivar for fresh market. Peter Wilcox also produces light-colored chips, although it is being released primarily as a fresh market potato because of its skin and flesh colors. Tubers of Peter Wilcox are attractive, smooth, wi...

  6. Induction of Purple Sulfur Bacterial Growth in Dairy Wastewater Lagoons by Circulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To determine if circulation of diary wastewater induces the growth of phototrophic purple sulfur bacteria (PSB). Methods and Results: Two dairy wastewater lagoons that were similar in size, geographic location, number and type of cattle loading the lagoons were chosen. The only obvious diffe...

  7. Anthocyanin, phenolics and antioxidant activity changes in purple waxy corn as affected by traditional cooking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antioxidant components, including anthocyanins and phenolic compounds, antioxidant activity, and their changes during traditional cooking of fresh purple waxy corn were investigated. As compared to the raw corn, thermal treatment caused significant (p < 0.05) decreases in each antioxidant compound a...

  8. Alexandrite-like effect in purple flowers analyzed with newly devised round RGB diagram

    NASA Astrophysics Data System (ADS)

    Kasajima, Ichiro

    2016-07-01

    The gemstone alexandrite is known for its feature to change color depending on the spectral quality of the incident light. Thus, the stone looks green when illuminated by white LED light but looks red when illuminated by incandescent light. This effect (alexandrite effect) is caused by a special relationship between the spectral quality of the incident light and the absorbance spectrum of the stone. Here we report an alexandrite-like effect in the petals of torenia and cyclamen flowers. These flowers are purple in sunlight but magenta (reddish) in incandescent light, and violet (bluish purple) in white LED light. The m-n, triangle and round diagrams are devised to calculate the colors of visible light spectra, based on the RGB color-matching function. Using these calculations, the alexandrite-like effect in purple flowers was successfully analyzed in terms of the interaction between the incident light spectrum and the absorbance spectrum of their purple anthocyanin. This analysis allows both logical and intuitive understanding of the colors exhibited by any object showing alexandrite–like properties.

  9. Migration and control of purple loosestrife (Lythrum salicaria L.) along highway corridors

    NASA Astrophysics Data System (ADS)

    Wilcox, Douglas A.

    1989-05-01

    The east-west density gradient and the pattern and mode of migration of the wetland exotic, purple loosestrife ( Lythrum salicaria L.), were assessed in a survey of populations along the New York State Thruway from Albany to Buffalo to determine if the highway corridor contributed to the spread of this species. During the peak flowering season of late July to early August, individual colonies of purple loosestrife were identified and categorized into three size classes in parallel belt transects consisting of the median strip and highway rights-of-way on the north and south sides of the road. Data were also collected on the presence of colonies adjacent to the corridor and on highway drainage patterns. Although a distinct east-west density gradient existed in the corridor, it corresponded to the gradient on adjacent lands and was greatly influenced by a major infestation at Montezuma National Wildlife Refuge. The disturbed highway corridor served as a migration route for purple loosestrife, but topographic features dictated that this migration was a short-distance rather than long-distance process. Ditch and culvert drainage patterns increased the ability of purple loosestrife to migrate to new wetland sites. Management strategies proposed to reduce the spread of this wetland threat include minimizing disturbance, pulling by hand, spraying with glyphosate, disking, and mowing.

  10. LC-PDA-EIS/MSn identification of new anthocyanins in purple radish (Raphanus sativus L. variety)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An LC-PDA-ESI/MSn profiling method was used for a comprehensive study of the anthocyanins of purple Bordeaux radish. This study identified 57 anthocyanins: 23 acylated cyanidin 3-sophoroside-5-diglucosides, 12 acylated cyanidin 3-(glucosylacyl) acylsophoroside-5-diglucosides, and 22 acylated cyanid...

  11. Effect of the Purple Corn Beverage "Chicha Morada" in Composite Resin during Dental Bleaching.

    PubMed

    Acuña, Eric Dario; Delgado-Cotrina, Leyla; Rumiche, Francisco Aurelio; Tay, Lidia Yileng

    2016-01-01

    During dental bleaching the staining potential of the surface would increase. This study aims to evaluate the staining susceptibility of one bleached composite resin after the exposure to three different beverages: Peruvian purple corn based beverage (chicha morada), green tea, and distilled water. Thirty disk-shaped specimens of one nanofill composite resin were prepared. The specimens were then divided into six groups (n = 5): purple corn (P), purple corn + bleaching (PB), green tea (T), green tea + bleaching (TB), distilled water (W), and distilled water + bleaching (WB). In groups that received bleaching, two sessions of bleaching with 35% hydrogen peroxide were done. Following bleaching, specimens were exposed to each liquid thirty minutes daily. Color was measured with a digital spectrophotometer. For statistical analysis, color measurement differences between the obtained results were used: during bleaching, after bleaching, and during + after bleaching. Two-way ANOVA was used to compare the color changes in the resins of all groups (p < 0.05). We conclude that all the evaluated beverages produced changes of color in the composite resin regardless of the bleaching procedure. However, purple corn was the only beverage that caused a perceptible color change (ΔE > 3.3). PMID:27034897

  12. Alexandrite-like effect in purple flowers analyzed with newly devised round RGB diagram

    PubMed Central

    Kasajima, Ichiro

    2016-01-01

    The gemstone alexandrite is known for its feature to change color depending on the spectral quality of the incident light. Thus, the stone looks green when illuminated by white LED light but looks red when illuminated by incandescent light. This effect (alexandrite effect) is caused by a special relationship between the spectral quality of the incident light and the absorbance spectrum of the stone. Here we report an alexandrite-like effect in the petals of torenia and cyclamen flowers. These flowers are purple in sunlight but magenta (reddish) in incandescent light, and violet (bluish purple) in white LED light. The m-n, triangle and round diagrams are devised to calculate the colors of visible light spectra, based on the RGB color-matching function. Using these calculations, the alexandrite-like effect in purple flowers was successfully analyzed in terms of the interaction between the incident light spectrum and the absorbance spectrum of their purple anthocyanin. This analysis allows both logical and intuitive understanding of the colors exhibited by any object showing alexandrite–like properties. PMID:27404088

  13. Evaluation of maturity group IV soybean lines for resistance to purple seed stains in Mississippi 2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple seed stain (PSS) of soybean is an important disease caused by Cercospora kikuchii. PSS reduces seed quality and market grade, affects seed germination and vigor, and has been reported wherever soybeans are grown worldwide. In 2009, PSS caused 6.4 million bushels of yield losses in 16 southern...

  14. Purple Nutsedge Tuber Productivity as Affected by Organic Mulches in a Watermelon Production System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research was conducted in Isabela, Puerto Rico, to determine the tuber productivity of the weed purple nutsedge (PN) and the yield of ‘Crimson Sweet' watermelon when grown with or without organic soil bed mulches [hays of millet (Pennisetum glaucum), nutsedge (Cyperus rotundus), sunnhemp (Crotalaria...

  15. IMPACT fragmentation model developments

    NASA Astrophysics Data System (ADS)

    Sorge, Marlon E.; Mains, Deanna L.

    2016-09-01

    The IMPACT fragmentation model has been used by The Aerospace Corporation for more than 25 years to analyze orbital altitude explosions and hypervelocity collisions. The model is semi-empirical, combining mass, energy and momentum conservation laws with empirically derived relationships for fragment characteristics such as number, mass, area-to-mass ratio, and spreading velocity as well as event energy distribution. Model results are used for several types of analysis including assessment of short-term risks to satellites from orbital altitude fragmentations, prediction of the long-term evolution of the orbital debris environment and forensic assessments of breakup events. A new version of IMPACT, version 6, has been completed and incorporates a number of advancements enabled by a multi-year long effort to characterize more than 11,000 debris fragments from more than three dozen historical on-orbit breakup events. These events involved a wide range of causes, energies, and fragmenting objects. Special focus was placed on the explosion model, as the majority of events examined were explosions. Revisions were made to the mass distribution used for explosion events, increasing the number of smaller fragments generated. The algorithm for modeling upper stage large fragment generation was updated. A momentum conserving asymmetric spreading velocity distribution algorithm was implemented to better represent sub-catastrophic events. An approach was developed for modeling sub-catastrophic explosions, those where the majority of the parent object remains intact, based on estimated event energy. Finally, significant modifications were made to the area-to-mass ratio distribution to incorporate the tendencies of different materials to fragment into different shapes. This ability enabled better matches between the observed area-to-mass ratios and those generated by the model. It also opened up additional possibilities for post-event analysis of breakups. The paper will discuss

  16. Identification and Characterization of DcUSAGT1, a UDP-Glucose: Sinapic Acid Glucosyltransferase from Purple Carrot Taproots

    PubMed Central

    Chen, Yi-Yun; Xu, Zhi-Sheng; Xiong, Ai-Sheng

    2016-01-01

    Purple carrots accumulate abundant cyanidin-based anthocyanins in taproots. UDP-glucose: sinapic acid glucosyltransferase (USAGT) can transfer the glucose moiety to the carboxyl group of sinapic acid thereby forming the ester bond between the carboxyl-C and the C1 of glucose (1-O-sinapoylglucose). 1-O-sinapoylglucose can serve as an acyl donor in acylation of anthocyanins and generate cyanidin 3-xylosyl (sinapoylglucosyl) galactoside in purple carrots. This final product helps stabilize the accumulation of anthocyanins. In this study, a gene named DcUSAGT1 encoding USAGT was cloned from ‘Deep purple’ carrot taproots. Enzymatic activity was determined using high performance liquid chromatography (HPLC). The optimal temperature and pH value were 30°C and 7.0, respectively. Kinetic analysis suggested a Km (sinapic acid) of 0.59 mM. Expression profiles of DcUSAGT1 showed high expression levels in the taproots of all the three purple carrot cultivars but low expression levels in those of non-purple carrot cultivars. The USAGT activity of different carrots in vitro indicated that crude enzyme extracted from the purple carrot taproots rather than non-purple carrot taproots exhibited USAGT activity. These results indicated that DcUSAGT1 may influence anthocyanin biosynthesis of purple carrot taproots. PMID:27171142

  17. Purple carrot extract protects against cadmium intoxication in multiple organs of rats: Genotoxicity, oxidative stress and tissue morphology analyses.

    PubMed

    Claudio, Samuel Rangel; Gollucke, Andrea Pittelli Boiago; Yamamura, Hirochi; Morais, Damila Rodrigues; Bataglion, Giovana Anceski; Eberlin, Marcos Nogueira; Peres, Rogerio Correa; Oshima, Celina Tizuko Fujiyama; Ribeiro, Daniel Araki

    2016-01-01

    The aim of this study was to investigate if purple carrot extract is able to protect against the noxious activities induced by cadmium exposure in multiple organs of rats. For this purpose, histopathological analysis, genotoxicity and oxidative status were investigated in this setting. A total of twenty Wistar rats weighing 250g on the average, and 8 weeks age were distributed into four groups (n=5), as follows: Control group (non-treated group, CTRL); Cadmium group (Cd) and Purple carrot extract groups at 400mg/L or 800mg/L. Histopathological analysis revealed that liver from animals treated with purple carrot extract improved tissue degeneration induced by cadmium intoxication. Genetic damage was reduced in blood and hepatocytes as depicted by comet and micronucleus assays in animals treated with purple carrot extract. SOD-CuZn and cytocrome C gene expression increased in groups treated with purple carrot extract. Purple carrot extract also reduced the 8OHdG levels in liver cells when compared to cadmium group. Taken together, our results demonstrate that purple carrot extract is able to protect against cadmium intoxication by means of reducing tissue regeneration, genotoxicity and oxidative stress in multiple organs of Wistar rats. PMID:26653742

  18. Fragment Screening of Human Aquaporin 1.

    PubMed

    To, Janet; Torres, Jaume

    2016-01-01

    Aquaporins (AQPs) are membrane proteins that enable water transport across cellular plasma membranes in response to osmotic gradients. Phenotypic analyses have revealed important physiological roles for AQPs, and the potential for AQP water channel modulators in various disease states has been proposed. For example, AQP1 is overexpressed in tumor microvessels, and this correlates with higher metastatic potential and aggressiveness of the malignancy. Chemical modulators would help in identifying the precise contribution of water channel activity in these disease states. These inhibitors would also be important therapeutically, e.g., in anti-cancer treatment. This perceived importance contrasts with the lack of success of high-throughput screens (HTS) to identify effective and specific inhibitors of aquaporins. In this paper, we have screened a library of 1500 "fragments", i.e., smaller than molecules used in HTS, against human aquaporin (hAQP1) using a thermal shift assay and surface plasmon resonance. Although these fragments may not inhibit their protein target, they bound to and stabilized hAQP1 (sub mM binding affinities (KD), with an temperature of aggregation shift ΔTagg of +4 to +50 °C) in a concentration-dependent fashion. Chemically expanded versions of these fragments should follow the determination of their binding site on the aquaporin surface. PMID:27023529

  19. Crystal structures of a purple acid phosphatase, representing different steps of this enzyme's catalytic cycle

    PubMed Central

    Schenk, Gerhard; Elliott, Tristan W; Leung, Eleanor; Carrington, Lyle E; Mitić, Nataša; Gahan, Lawrence R; Guddat, Luke W

    2008-01-01

    Background Purple acid phosphatases belong to the family of binuclear metallohydrolases and are involved in a multitude of biological functions, ranging from bacterial killing and bone metabolism in animals to phosphate uptake in plants. Due to its role in bone resorption purple acid phosphatase has evolved into a promising target for the development of anti-osteoporotic chemotherapeutics. The design of specific and potent inhibitors for this enzyme is aided by detailed knowledge of its reaction mechanism. However, despite considerable effort in the last 10 years various aspects of the basic molecular mechanism of action are still not fully understood. Results Red kidney bean purple acid phosphatase is a heterovalent enzyme with an Fe(III)Zn(II) center in the active site. Two new structures with bound sulfate (2.4 Å) and fluoride (2.2 Å) provide insight into the pre-catalytic phase of its reaction cycle and phosphorolysis. The sulfate-bound structure illustrates the significance of an extensive hydrogen bonding network in the second coordination sphere in initial substrate binding and orientation prior to hydrolysis. Importantly, both metal ions are five-coordinate in this structure, with only one nucleophilic μ-hydroxide present in the metal-bridging position. The fluoride-bound structure provides visual support for an activation mechanism for this μ-hydroxide whereby substrate binding induces a shift of this bridging ligand towards the divalent metal ion, thus increasing its nucleophilicity. Conclusion In combination with kinetic, crystallographic and spectroscopic data these structures of red kidney bean purple acid phosphatase facilitate the proposal of a comprehensive eight-step model for the catalytic mechanism of purple acid phosphatases in general. PMID:18234116

  20. Characterizing the Purple Earth: Modeling the globally integrated spectral variability of the Archean Earth

    SciTech Connect

    Sanromá, E.; Pallé, E.; López, R.; Montañés-Rodríguez, P.; Kiang, N. Y.; Gutiérrez-Navarro, A. M.

    2014-01-01

    Ongoing searches for exoplanetary systems have revealed a wealth of planets with diverse physical properties. Planets even smaller than the Earth have already been detected and the efforts of future missions are aimed at the discovery, and perhaps characterization, of small rocky exoplanets within the habitable zone of their stars. Clearly, what we know about our planet will be our guideline for the characterization of such planets. However, the Earth has been inhabited for at least 3.8 Gyr and its appearance has changed with time. Here, we have studied the Earth during the Archean eon, 3.0 Gyr ago. At that time, one of the more widespread life forms on the planet was purple bacteria. These bacteria are photosynthetic microorganisms and can inhabit both aquatic and terrestrial environments. Here, we use a radiative transfer model to simulate the visible and near-infrared radiation reflected by our planet, taking into account several scenarios regarding the possible distribution of purple bacteria over continents and oceans. We find that purple bacteria have a reflectance spectrum that has a strong reflectivity increase, similar to the red edge of leafy plants, although shifted redward. This feature produces a detectable signal in the disk-averaged spectra of our planet, depending on cloud amount and purple bacteria concentration/distribution. We conclude that by using multi-color photometric observations, it is possible to distinguish between an Archean Earth in which purple bacteria inhabit vast extensions of the planet and a present-day Earth with continents covered by deserts, vegetation, or microbial mats.

  1. Characterizing the Purple Earth: Modeling the Globally Integrated Spectral Variability of the Archean Earth

    NASA Astrophysics Data System (ADS)

    Sanromá, E.; Pallé, E.; Parenteau, M. N.; Kiang, N. Y.; Gutiérrez-Navarro, A. M.; López, R.; Montañés-Rodríguez, P.

    2014-01-01

    Ongoing searches for exoplanetary systems have revealed a wealth of planets with diverse physical properties. Planets even smaller than the Earth have already been detected and the efforts of future missions are aimed at the discovery, and perhaps characterization, of small rocky exoplanets within the habitable zone of their stars. Clearly, what we know about our planet will be our guideline for the characterization of such planets. However, the Earth has been inhabited for at least 3.8 Gyr and its appearance has changed with time. Here, we have studied the Earth during the Archean eon, 3.0 Gyr ago. At that time, one of the more widespread life forms on the planet was purple bacteria. These bacteria are photosynthetic microorganisms and can inhabit both aquatic and terrestrial environments. Here, we use a radiative transfer model to simulate the visible and near-infrared radiation reflected by our planet, taking into account several scenarios regarding the possible distribution of purple bacteria over continents and oceans. We find that purple bacteria have a reflectance spectrum that has a strong reflectivity increase, similar to the red edge of leafy plants, although shifted redward. This feature produces a detectable signal in the disk-averaged spectra of our planet, depending on cloud amount and purple bacteria concentration/distribution. We conclude that by using multi-color photometric observations, it is possible to distinguish between an Archean Earth in which purple bacteria inhabit vast extensions of the planet and a present-day Earth with continents covered by deserts, vegetation, or microbial mats.

  2. Target fragmentation in radiobiology

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Cucinotta, Francis A.; Shinn, Judy L.; Townsend, Lawrence W.

    1993-01-01

    Nuclear reactions in biological systems produce low-energy fragments of the target nuclei seen as local high events of linear energy transfer (LET). A nuclear-reaction formalism is used to evaluate the nuclear-induced fields within biosystems and their effects within several biological models. On the basis of direct ionization interaction, one anticipates high-energy protons to have a quality factor and relative biological effectiveness (RBE) of unity. Target fragmentation contributions raise the effective quality factor of 10 GeV protons to 3.3 in reasonable agreement with RBE values for induced micronuclei in bean sprouts. Application of the Katz model indicates that the relative increase in RBE with decreasing exposure observed in cell survival experiments with 160 MeV protons is related solely to target fragmentation events. Target fragment contributions to lens opacity given an RBE of 1.4 for 2 GeV protons in agreement with the work of Lett and Cox. Predictions are made for the effective RBE for Harderian gland tumors induced by high-energy protons. An exposure model for lifetime cancer risk is derived from NCRP 98 risk tables, and protraction effects are examined for proton and helium ion exposures. The implications of dose rate enhancement effects on space radiation protection are considered.

  3. Membrane stabilizer

    DOEpatents

    Mingenbach, William A.

    1988-01-01

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material.

  4. Tracing of backward energy transfer from LH1 to LH2 in photosynthetic membranes grown under high and low irradiation.

    NASA Astrophysics Data System (ADS)

    Lüer, L.; Moulisová, V.; Henry, S.; Polli, D.; Brotosudarmo, T. H. P.; Hoseinkhani, S.; Brida, D.; Lanzani, G.; Cerullo, G.; Cogdell, R. J.

    2013-03-01

    By introducing derivative transient absorption spectroscopy, we obtain rate constants for backward and forward energy transfer between LH1 and LH2 complexes in purple bacterial membranes. We find that backward energy transfer is strongly reduced in membranes grown under low irradiation conditions, compared to high light grown ones. We conclude that backward energy transfer is managed actively by the bacteria to avoid LH1 exciton deactivation under high irradiation conditions. The analytical method is generally applicable to excitonically coupled systems.

  5. A method for estimation of permittivity in photosynthetic membranes and the effect of permittivity on the photosynthetic quantum yield

    NASA Astrophysics Data System (ADS)

    Borisov, A. Yu.

    2013-02-01

    A new method for estimation of the internal permittivity of photosynthetic membranes is based on joint analysis of the optical data with high spectral resolution and precise X-ray data. The permittivity of the bacteriochlorophyll-containing membranes of purple bacteria ranges from 1.62 to 1.75. The relatively low permittivity of photosynthetic organisms provides a significant increase in the efficiency of energy migration from multiple antenna chlorophylls to reaction centers and photosynthetic efficiency in general.

  6. Shielding and fragmentation studies.

    PubMed

    Zeitlin, C; Guetersloh, S; Heilbronn, L; Miller, J

    2005-01-01

    Radiation dosimetry for manned spaced missions depends on the ability to adequately describe the process of high-energy ion transport through many materials. Since the types of possible nuclear interactions are many and complex, transport models are used which depend upon a reliable source of experimental data. To expand the heavy ion database used in the models we have been measuring charge-changing cross sections and fragment production cross sections from heavy-ion interactions in various elementa targets. These include materials flown on space missions such as carbon and aluminium, as well as those important in radiation dosimetry such as hydrogen, nitrogen and water. Measuring heavy-ion fragmentation through these targets also gives us the ability to determine the effectiveness of new materials proposed for shielding such as graphite composites and polyethylene hybrids. Measurement without a target present gives an indication of the level of contamination of the primary beam, which is also important in radiobiology experiments. PMID:16604611

  7. Extreme Genetic Structure in a Small-Bodied Freshwater Fish, the Purple Spotted Gudgeon, Mogurnda adspersa (Eleotridae)

    PubMed Central

    Hughes, Jane M.; Real, Kathryn M.; Marshall, Jonathan C.; Schmidt, Daniel J.

    2012-01-01

    Freshwater fish are a group that is especially susceptible to biodiversity loss as they often exist naturally in small, fragmented populations that are vulnerable to habitat degradation, pollution and introduction of exotic species. Relatively little is known about spatial dynamics of unperturbed populations of small-bodied freshwater fish species. This study examined population genetic structure of the purple spotted gudgeon (Mogurnda adspersa, Eleotridae), a small-bodied freshwater fish that is widely distributed in eastern Australia. The species is threatened in parts of its range but is common in coastal streams of central Queensland where this study took place. Microsatellite (msat) and mitochondrial DNA (mtDNA) variation was assessed for nine sites from four stream sections in two drainage basins. Very high levels of among population structure were observed (msat FST = 0.18; mtDNA ΦST = 0.85) and evidence for contemporary migration among populations was rare and limited to sites within the same section of stream. Hierarchical structuring of variation was best explained by stream section rather than by drainage basin. Estimates of contemporary effective population size for each site was low (range 28 – 63, Sibship method), but compared favorably with similar estimates for other freshwater fish species, and there was no genetic evidence for inbreeding or recent population bottlenecks. In conclusion, within a stable part of its range, M adspersa exists as a series of small, demographically stable populations that are highly isolated from one another. Complimentary patterns in microsatellites and mtDNA indicate this structuring is the result of long-term processes that have developed over a remarkably small spatial scale. High population structure and limited dispersal mean that recolonisation of locally extinct populations is only likely to occur from closely situated populations within stream sections. Limited potential for recolonisation should be

  8. Fracture, failure, and fragmentation

    SciTech Connect

    Dienes, J.K.

    1984-01-01

    Though continuum descriptions of material behavior are useful for many kinds of problems, particularly those involving plastic flow, a more general approach is required when the failure is likely to involve growth and coalescence of a large number of fractures, as in fragmentation. Failures of this kind appear frequently in rapid dynamic processes such as those resulting from impacts and explosions, particularly in the formation of spall fragments. In the first part of this paper an approach to formulating constitutive relations that accounts for the opening, shear and growth of an ensemble of cracks is discussed. The approach also accounts for plastic flow accompanying fragmentation. The resulting constitutive relations have been incorporated into a Lagrangean computer program. In the second part of this paper a theoretical approach to coalescence is described. The simplest formulation makes use of a linear Liouville equation, with crack growth limited by the mean free path of cracks, assumed constant. This approach allows for an anisotropic distribution of cracks. An alternative approach is also described in which the decrease of the mean free path with increasing crack size is accounted for, but the crack distribution is assumed isotropic. A reduction of the governing Liouville equation to an ordinary differential equation of third order is possible, and the result can be used to determine how mean-free-path decreases with increasing crack size.

  9. Fragment-based lead design

    NASA Astrophysics Data System (ADS)

    Filz, O. A.; Poroikov, Vladimir V.

    2012-02-01

    State-of-the-art approaches to the fragment-based design of organic compounds with desired properties are considered. The review covers methods, which are used in different steps of the design, such as computational methods for fragment library design, experimental and computational methods for fragment discovery and methods for the generation of structures of organic compounds. Examples are given of drug candidates, which were constructed using the fragment-based approach. The bibliography includes 156 references.

  10. Phenolic composition and antioxidant capacity of yellow and purple-red Ecuadorian cultivars of tree tomato (Solanum betaceum Cav.).

    PubMed

    Espin, Susana; Gonzalez-Manzano, Susana; Taco, Verónica; Poveda, Cristina; Ayuda-Durán, Begoña; Gonzalez-Paramas, Ana M; Santos-Buelga, Celestino

    2016-03-01

    Tree tomato fruits from the yellow giant, giant purple and New Zealand purple cultivars, cultivated in Ecuador were analysed for their phenolic composition and antioxidant capacity. Twelve hydroxycinnamoyl derivatives and four anthocyanins (in the purple cultivars) were detected and identified. The hydroxycinnamoyl derivatives mostly derived from caffeic acid, being 3-O-caffeoylquinic acid and rosmarinic acid the majority compounds. Furthermore, various rosmarinic acid glucosides, caffeoyl glucoside, feruloyl glucoside and two ferulic acid dehydrodimers were tentatively identified. The presence of rosmarinic acid is particularly relevant as it constituted a majority phenolic compound in the four studied tree tomato cultivars and it had not been reported previously in this fruit. In the purple cultivars main anthocyanins were pelargonidin 3-O-rutinoside and delphinidin 3-O-rutinoside. The New Zealand purple cultivar was by far the richest sample in both hydroxycinnamates (421.6mg/100g dry pulp) and anthocyanins (168.9mg/100g dry pulp). Antioxidant capacity, as determined by FRAP, ABTS and ORAC assays, followed the same pattern as phenolic contents, with the New Zealand purple cultivar being the one with the highest and the yellow giant cultivar with the lowest values. PMID:26471655

  11. Stoichiometric and kinetic studies of phenolic antioxidants from Andean purple corn and red-fleshed sweetpotato.

    PubMed

    Cevallos-Casals, Bolívar A; Cisneros-Zevallos, Luis

    2003-05-21

    Stoichiometric and kinetic values of phenolics against DPPH (2,2-diphenyl-1-picrylhydrazyl) were determined for Andean purple corn (Zea mays L.) and red sweetpotato (Ipomoea batatas). Both crops had higher antioxidant capacity and antiradical kinetics than blueberries and higher or similar anthocyanin and phenolic contents. The second-order rate constant (k(2)) was 1.56, 1.12, 0.57, and 0.26 (mg antiradical/mL)(-1) s(-1) for red sweetpotato, Trolox, purple corn, and blueberry, respectively. On the molar basis of active hydroxyl groups, k(2)' showed the same order as for k(2). Corn cob and sweetpotato endodermis contributed the most in phenolic compounds and antioxidant capacity. Both crops studied can be considered as excellent novel sources of natural antioxidants for the functional food and dietary supplement markets. PMID:12744660

  12. An analytical pipeline to compare and characterise the anthocyanin antioxidant activities of purple sweet potato cultivars.

    PubMed

    Hu, Yijie; Deng, Liqing; Chen, Jinwu; Zhou, Siyu; Liu, Shuang; Fu, Yufan; Yang, Chunxian; Liao, Zhihua; Chen, Min

    2016-03-01

    Purple sweet potato (Ipomoea batatas L.) is rich in anthocyanin pigments, which are valuable constituents of the human diet. Techniques to identify and quantify anthocyanins and their antioxidant potential are desirable for cultivar selection and breeding. In this study, we performed a quantitative and qualitative chemical analysis of 30 purple sweet potato (PSP) cultivars, using various assays to measure reducing power radical-scavenging activities, and linoleic acid autoxidation inhibition activity. Grey relational analysis (GRA) was applied to establish relationships between the antioxidant activities and the chemical fingerprints, in order to identify key bioactive compounds. The results indicated that four peonidin-based anthocyanins and three cyanidin-based anthocyanins make significant contributions to antioxidant activity. We conclude that the analytical pipeline described here represents an effective method to evaluate the antioxidant potential of, and the contributing compounds present in, PSP cultivars. This approach may be used to guide future breeding strategies. PMID:26471525

  13. Calf thymus DNA-binding ability study of anthocyanins from purple sweet potatoes ( Ipomoea batatas L.).

    PubMed

    Wang, Dan; Wang, Xirui; Zhang, Chao; Ma, Yue; Zhao, Xiaoyan

    2011-07-13

    A total of 10 anthocyanin compounds were identified from five purple sweet potato ( Ipomoea batatas L.) varieties, Qunzi, Zishu038, Ji18, Jingshu6, and Ziluolan, by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to assess their calf thymus DNA-binding ability in vitro. The interaction between anthocyanins and calf thymus DNA in Tris-HCl buffer solution (pH 6.9) was evaluated by fluorescence spectroscopy. Using ethidium bromide (EB) as a fluorescence probe, fluorescence quenching of the emission peak was seen in the DNA-EB system when anthocyanins were added, indicating that the anthocyanins bound with DNA. The acylated groups influenced the ability of the interaction with DNA. Anthocyanins from purple sweet potato with more acylated groups in sorphorose have a stronger binding ability with DNA. PMID:21678894

  14. A purple-colored 1M mica clay from Silverton, Colorado

    USGS Publications Warehouse

    Tien, P.-L.

    1969-01-01

    A purple-colored clay of 1M mica polymorph in association with lead-zinc ore was collected from an abandoned mine dump near Silverton, Colorado. Electron micrographs show that the crystallites of the clay are less than 2?? in size and have poorly developed hexagonal outlines. Differential thermal and i.r. absorption analyses indicate similarity with those of muscovite. The structural formula of the 1M mica polymorph is (K1??45Na0??02) (Al3??75Mg0??19) (Si6??90Al1??10) O20(OH)4. The purple color may be related to trace amounts of manganese in the clay. ?? 1969.

  15. Tuning photoluminescence of reduced graphene oxide quantum dots from blue to purple

    SciTech Connect

    Liu, Fuchi; Tang, Tao; Feng, Qian; Li, Ming; Liu, Yuan; Tang, Nujiang Zhong, Wei; Du, Youwei

    2014-04-28

    Reduced graphene oxide quantum dots (rGOQDs) were synthesized by annealing GOQDs in H{sub 2} atmosphere. The photoluminescence (PL) properties of GOQDs and the rGOQDs samples were investigated. The results showed that compared to GOQDs, a blue to purple tunable PL of rGOQDs can be obtained by regulating the annealing temperature. The increase fraction of the newly formed isolated sp{sup 2} clusters may be responsible for the observed tunable PL.

  16. A Simple Evaluation of Soil Quality of Waterlogged Purple Paddy Soils with Different Productivities

    PubMed Central

    Liu, Zhanjun; Zhou, Wei; Lv, Jialong; He, Ping; Liang, Guoqing; Jin, Hui

    2015-01-01

    Evaluation of soil quality can be crucial for designing efficient farming systems and ensuring sustainable agriculture. The present study aimed at evaluating the quality of waterlogged purple paddy soils with different productivities in Sichuan Basin. The approach involved comprehensive analyses of soil physical and chemical properties, as well as enzyme activities and microbial community structure measured by phospholipid fatty acid analysis (PLFA). A total of 36 soil samples were collected from four typical locations, with 12 samples representing high productivity purple paddy soil (HPPS), medium productivity purple paddy soil (MPPS) and low productivity purple paddy soil (LPPS), respectively. Most measured soil properties showed significant differences (P ≤ 0.05) among HPPS, MPPS and LPPS. Pearson correlation analysis and principal component analysis were used to identify appropriate soil quality indicators. A minimum data set (MDS) including total nitrogen (TN), available phosphorus (AP), acid phosphatase (ACP), total bacteria (TB) and arbuscular mycorrhizal fungi was established and accounted for 82.1% of the quality variation among soils. A soil quality index (SQI) was developed based on the MDS method, whilst HPPS, MPPS and LPPS received mean SQI scores of 0.725, 0.536 and 0.425, respectively, with a ranking of HPPS > MPPS > LPPS. HPPS showed relatively good soil quality characterized by optimal nutrient availability, enzymatic and microbial activities, but the opposite was true of LPPS. Low levels of TN, AP and soil microbial activities were considered to be the major constraints limiting the productivity in LPPS. All soil samples collected were rich in available N, K, Si and Zn, but deficient in available P, which may be the major constraint for the studied regions. Managers in our study area should employ more appropriate management in the LPPS to improve its rice productivity, and particularly to any potential limiting factor. PMID:25997107

  17. Modeling the globally-integrated spectral variability of the Archean Earth: The purple planet

    NASA Astrophysics Data System (ADS)

    Palle, E.; Sanroma, E.; Parenteau, M. N.; Kiang, N. Y.; Gutierrez-Navarro, A. M.; Lopez, R.; Montañes-Rodríguez, P.

    2014-03-01

    Ongoing searches for exoplanetary systems have revealed a wealth of planets with diverse physical properties. Planets even smaller than the Earth have already been detected and the efforts of future missions are aimed at the discovery, and perhaps characterization, of small rocky exoplanets within the habitable zone of their stars. Clearly, what we know about our planet will be our guideline for the characterization of such planets. But the Earth has been inhabited for at least 3.8 Gyr and its appearance has changed with time. Here, we have studied the Earth during the Archean eon, 3 Gyr ago. At that time, one of the more widespread life forms on the planet were purple bacteria. These bacteria are photosynthetic microorganisms and can inhabit both aquatic and terrestrial environments. Here, we use a radiative transfer model to simulate the visible and near-infrared radiation reflected by our planet, taking into account several scenarios regarding the possible distribution of purple bacteria over continents and oceans. We find that purple bacteria have a reflectance spectrum that has a strong reflectivity increase, similar to the red edge of leafy plants, although shifted redward. This feature produces a detectable signal in the disk-averaged spectra of our planet, depending on cloud amount and bacteria concentration/ distribution. We conclude that by using multi-color photometric observations, it is possible to distinguish between an Archean Earth in which purple bacteria inhabit vast extensions of the planet and a present-day Earth with continents covered by deserts, vegetation, or microbial mats.

  18. The Diagnostic Accuracy of Purple Line in Prediction of Labor Progress in Omolbanin Hospital, Iran

    PubMed Central

    Kordi, Masoumeh; Irani, Morvarid; Tara, Fatemeh; Esmaily, Habibollah

    2014-01-01

    Background: Currently, vaginal examination is the gold standard for assessment of labor progress. The World Health Organization emphasizes that the number of vaginal examinations should be limited where it is necessary. Objectives: Therefore, this study aimed to determine the diagnostic accuracy of purple line in the prediction of labor progress. Patients and Methods: In this cross-sectional study, 350 women with a single pregnancy in vertex presentation and gestational age of 38-42 weeks without any medical disorder, admitted to government hospitals of Mashhad, were selected using convenience sampling. Vaginal examination and observation of the line each hour in the active phase of labor were measured. Abnormal progress of labor was defined as cervical dilatation less than 1 centimeter/hour in the active phase for two consecutive hours and fetal head descend less than 1cm/h or duration of more than two hours for nulliparous and one hour for multiparous In the second stage of labor. Data was analyzed by SPSS version 16 using chi -square test. Results: The purple line appeared in 75.3% of women during the active phase of labor. Appearance of the purple line in the prediction of labor progress had 90.2% sensitivity, 45.3% specificity, 88.1% positive predictive value, 51.0% negative predictive value in the first stage of labor and had 87.6% sensitivity, 52.4% specificity, 96.5% positive predictive value, 22.0% negative predictive value in the second stage of labor and has 68.57% sensitivity, 42.66% specificity, 85.32% positive predictive value, and 43.85% negative predictive value for the total labor. Conclusions: According to the appearance of the purple line in most of the cases and its high sensitivity and specificity, we can use it as a non-invasive complementary method for clinical assessment of labor progress. PMID:25763210

  19. Comparative Transcriptome Analysis of White and Purple Potato to Identify Genes Involved in Anthocyanin Biosynthesis

    PubMed Central

    Liu, Yuhui; Lin-Wang, Kui; Deng, Cecilia; Warran, Ben; Wang, Li; Yu, Bin; Yang, Hongyu; Wang, Jing; Espley, Richard V.; Zhang, Junlian; Wang, Di; Allan, Andrew C.

    2015-01-01

    Introduction The potato (Solanum tuberosum) cultivar ‘Xin Daping’ is tetraploid with white skin and white flesh, while the cultivar ‘Hei Meiren’ is also tetraploid with purple skin and purple flesh. Comparative transcriptome analysis of white and purple cultivars was carried out using high-throughput RNA sequencing in order to further understand the mechanism of anthocyanin biosynthesis in potato. Methods and Results By aligning transcript reads to the recently published diploid potato genome and de novo assembly, 209 million paired-end Illumina RNA-seq reads from these tetraploid cultivars were assembled on to 60,930 transcripts, of which 27,754 (45.55%) are novel transcripts and 9393 alternative transcripts. Using a comparison of the RNA-sequence datasets, multiple versions of the genes encoding anthocyanin biosynthetic steps and regulatory transcription factors were identified. Other novel genes potentially involved in anthocyanin biosynthesis in potato tubers were also discovered. Real-time qPCR validation of candidate genes revealed good correlation with the transcriptome data. SNPs (Single Nucleotide Polymorphism) and indels were predicted and validated for the transcription factors MYB AN1 and bHLH1 and the biosynthetic gene anthocyanidin 3-O-glucosyltransferase (UFGT). Conclusions These results contribute to our understanding of the molecular mechanism of white and purple potato development, by identifying differential responses of biosynthetic gene family members together with the variation in structural genes and transcription factors in this highly heterozygous crop. This provides an excellent platform and resource for future genetic and functional genomic research. PMID:26053878

  20. Control of yellow and purple nutsedge in elevated CO2 environments with glyphosate and halosulfuron.

    PubMed

    Marble, S Christopher; Prior, Stephen A; Runion, G Brett; Torbert, H Allen

    2015-01-01

    Atmospheric concentrations of carbon dioxide (CO2) have significantly increased over the past century and are expected to continue rising in the future. While elevated levels of CO2 will likely result in higher crop yields, weed growth is also highly likely to increase, which could increase the incidence of herbicide resistant biotypes. An experiment was conducted in 2012 to determine the effects of an elevated CO2 environment on glyphosate and halosulfuron efficacy for postemergence control of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.). Both species of nutsedge where grown in 3.0-L containers under either ambient or elevated (ambient + 200 μmol mol(-1)) CO2 in open-top field chambers and treated with either 0.5×, 1.0×, or 1.5× of the manufacturer's labeled rate of halosulfuron, glyphosate, or a tank mix of the two herbicides. The growth of both nutsedge species responded positively to elevated CO2, purple nutsedge had increased shoot and root dry weights and yellow nutsedge had increased shoot, root, and tuber dry weights and counts. Few treatment differences were observed among the herbicides at any of the rates tested. At 3 weeks following herbicide application, both purple and yellow nutsedge were adequately controlled by both herbicides and combinations at all rates tested, regardless of CO2 concentration. Based on this study, it is likely that predicted future CO2 levels will have little impact on the efficacy of single applications of halosulfuron or glyphosate for control of purple and yellow nutsedge at the growth stages described here, although scenarios demanding more persistent control efforts remain a question. PMID:25653664

  1. Control of yellow and purple nutsedge in elevated CO2 environments with glyphosate and halosulfuron

    PubMed Central

    Marble, S. Christopher; Prior, Stephen A.; Runion, G. Brett; Torbert, H. Allen

    2015-01-01

    Atmospheric concentrations of carbon dioxide (CO2) have significantly increased over the past century and are expected to continue rising in the future. While elevated levels of CO2 will likely result in higher crop yields, weed growth is also highly likely to increase, which could increase the incidence of herbicide resistant biotypes. An experiment was conducted in 2012 to determine the effects of an elevated CO2 environment on glyphosate and halosulfuron efficacy for postemergence control of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.). Both species of nutsedge where grown in 3.0-L containers under either ambient or elevated (ambient + 200 μmol mol−1) CO2 in open-top field chambers and treated with either 0.5×, 1.0×, or 1.5× of the manufacturer's labeled rate of halosulfuron, glyphosate, or a tank mix of the two herbicides. The growth of both nutsedge species responded positively to elevated CO2, purple nutsedge had increased shoot and root dry weights and yellow nutsedge had increased shoot, root, and tuber dry weights and counts. Few treatment differences were observed among the herbicides at any of the rates tested. At 3 weeks following herbicide application, both purple and yellow nutsedge were adequately controlled by both herbicides and combinations at all rates tested, regardless of CO2 concentration. Based on this study, it is likely that predicted future CO2 levels will have little impact on the efficacy of single applications of halosulfuron or glyphosate for control of purple and yellow nutsedge at the growth stages described here, although scenarios demanding more persistent control efforts remain a question. PMID:25653664

  2. Virtual fragment preparation for computational fragment-based drug design.

    PubMed

    Ludington, Jennifer L

    2015-01-01

    Fragment-based drug design (FBDD) has become an important component of the drug discovery process. The use of fragments can accelerate both the search for a hit molecule and the development of that hit into a lead molecule for clinical testing. In addition to experimental methodologies for FBDD such as NMR and X-ray Crystallography screens, computational techniques are playing an increasingly important role. The success of the computational simulations is due in large part to how the database of virtual fragments is prepared. In order to prepare the fragments appropriately it is necessary to understand how FBDD differs from other approaches and the issues inherent in building up molecules from smaller fragment pieces. The ultimate goal of these calculations is to link two or more simulated fragments into a molecule that has an experimental binding affinity consistent with the additive predicted binding affinities of the virtual fragments. Computationally predicting binding affinities is a complex process, with many opportunities for introducing error. Therefore, care should be taken with the fragment preparation procedure to avoid introducing additional inaccuracies.This chapter is focused on the preparation process used to create a virtual fragment database. Several key issues of fragment preparation which affect the accuracy of binding affinity predictions are discussed. The first issue is the selection of the two-dimensional atomic structure of the virtual fragment. Although the particular usage of the fragment can affect this choice (i.e., whether the fragment will be used for calibration, binding site characterization, hit identification, or lead optimization), general factors such as synthetic accessibility, size, and flexibility are major considerations in selecting the 2D structure. Other aspects of preparing the virtual fragments for simulation are the generation of three-dimensional conformations and the assignment of the associated atomic point charges

  3. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    PubMed Central

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R2 = 0.90) and ascorbic acid (R2 = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  4. Characterization of Bacterial Communities Associated with the Tyrian Purple Producing Gland in a Marine Gastropod

    PubMed Central

    Ngangbam, Ajit Kumar; Baten, Abdul; Waters, Daniel L. E.; Whalan, Steve; Benkendorff, Kirsten

    2015-01-01

    Dicathais orbita is a marine mollusc recognised for the production of anticancer compounds that are precursors to Tyrian purple. This study aimed to assess the diversity and identity of bacteria associated with the Tyrian purple producing hypobranchial gland, in comparison with foot tissue, using a high-throughput sequencing approach. Taxonomic and phylogenetic analysis of variable region V1-V3 of 16S rRNA bacterial gene amplicons in QIIME and MEGAN were carried out. This analysis revealed a highly diverse bacterial assemblage associated with the hypobranchial gland and foot tissues of D. orbita. The dominant bacterial phylum in the 16S rRNA bacterial profiling data set was Proteobacteria followed by Bacteroidetes, Tenericutes and Spirochaetes. In comparison to the foot, the hypobranchial gland had significantly lower bacterial diversity and a different community composition, based on taxonomic assignment at the genus level. A higher abundance of indole producing Vibrio spp. and the presence of bacteria with brominating capabilities in the hypobranchial gland suggest bacteria have a potential role in biosynthesis of Tyrian purple in D. orbita. PMID:26488885

  5. Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.

    PubMed

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R(2) = 0.90) and ascorbic acid (R(2) = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  6. Preventive effect of Zea mays L. (purple waxy corn) on experimental diabetic cataract.

    PubMed

    Thiraphatthanavong, Paphaphat; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Wipawee, Thukham-mee; Wannanon, Panakaporn; Terdthai, Tong-un; Suriharn, Bhalang; Lertrat, Kamol

    2014-01-01

    Recently, substances possessing antioxidant can prevent cataractogenesis of diabetic cataract. Therefore, this study was carried out to determine the anticataract effect of Zea mays L. (purple waxy corn), a flavonoids rich plant, in experimental diabetic cataract. Enucleated rat lenses were incubated in artificial aqueous humor containing 55 mM glucose with various concentrations of Zea mays L. (purple waxy corn) ranging between 2, 10, and 50 mg/mL at room temperature for 72 h. At the end of the incubation period, the evaluation of lens opacification, MDA level, and the activities of SOD, CAT, GPx, and AR in lens were performed. The results showed that both medium and high doses of extract decreased lens opacity together with the decreased MDA level. In addition, medium dose of extract increased GPx activity while the high dose decreased AR activity. No other significant changes were observed. The purple waxy corn seeds extract is the potential candidate to protect against diabetic cataract. The mechanism of action may occur via the decreased oxidative stress and the suppression of AR. However, further research in vivo is still essential. PMID:24527449

  7. Composition and thermal stability of anthocyanins from chinese purple corn ( Zea mays L.).

    PubMed

    Zhao, Xiaoyan; Corrales, Margarita; Zhang, Chao; Hu, Xiaosong; Ma, Yue; Tauscher, Bernhard

    2008-11-26

    Chinese purple corn extracts ( Zea mays L., Zhuozhou, Hebei, China) (EZPC) were selected among five Chinese purple corn hybrids due to their higher anthocyanin content, and their thermal stability was evaluated. The total anthocyanin content and total phenolic content of EZPC were 304.5 +/- 16.32 mg of cyanidin-3-glucoside equiv/100 g of dry seeds and 489.8 +/- 24.90 mg of gallic acid equiv/100 g of dry seeds, respectively. Moreover, the individual anthocyanins of EZPC were determined by HPLC-DAD/ESI-MS analysis. Seven main compounds were determined, including cyanidin-3-(malonylglucoside), cyanidin-3-O-glucoside-2-malonylglucoside, cyanidin-3-O-glucoside, peonidin-3-O-glucoside, peonidin-3-(malonylglucoside), pelargonidin-3-(6''-malonylglucoside), and peonidin-3-(dimalonylglucoside). The thermal stability of EZPC was studied by differential scanning calorimetry. Thermodynamic analysis showed that the conversion of EZPC followed an Arrhenius relationship, where the delta enthalpy (H) and activation energy (E(a)) were 97.0 J/g and 204 +/- 2.72 kJ/mol, respectively. Furthermore, the relationships between the degree of conversion of EZPC and time or temperature were reported. This study demonstrated that the evaluated Chinese purple corn hybrids are a natural source of anthocyanins and are stable over a wide range of temperatures and times. PMID:18950186

  8. Food and feeding ecology of purple sandpipers Calidris maritima on rocky intertidal habitats (Helgoland, German Bight)

    NASA Astrophysics Data System (ADS)

    Dierschke, Volker

    On the island of Helgoland (German Bight) Purple Sandpipers Calidris maritima feed mainly in the intertidal of piers and rocky shores. The main prey species are Littorina saxatilis and Mytilus edulis, complemented by crustaceans, polychaetes, other molluscs and green algae. Beach habitats are used as alternative feeding sites during storms. Feeding sites seem to be selected according to rates of assimilated energy intake. The most profitable habitat (wrack beds on the high-tide line with kelp-fly larvae, 16.8 W) is used after arrival in October but is not available during winter. Because of high intake rates in rocky habitats (13.1 W on piers, 5.5 W on mussel beds), which allow short daily feeding times, and available alternative feeding sites during storms, Purple Sandpipers do not need to carry fat reserves in winter like other waders wintering in central and Western Europe. This, and the ever accessible food supply of epibenthic macrofauna on rocky shores, may enable Purple Sandpipers to winter further north than other wader species.

  9. Spatial and temporal variation in results of purple urchin (Strongylocentrotus purpuratus) toxicity tests with zinc

    SciTech Connect

    Phillips, B.M.; Anderson, B.S.; Hunt, J.W.

    1998-03-01

    Purple urchins (Strongylocentrotus purpuratus) were maintained in year-round spawning condition in the laboratory for use in fertilization and larval development experiments designed to assess temporal variability in response to zinc. Results of these tests were compared to those from tests using gametes obtained from a field-collected population. Fertilization and larval development tests were also conducted comparing field-collected purple urchins from three geographically distinct groups on the West Coast of the United States. Fertilization tests conducted to assess temporal variability produced variable median effects concentrations (EC50s) ranging from 4.1 to >100 {micro}g/L zinc. Larval development tests did not demonstrate significant differences in response to zinc between geographically distinct purple urchin populations. Fertilization test variability was examined in terms of sperm concentration and sperm collection method during two seasons. Reduced variability was found with dry sperm collection in tests conducted in March 1995 but increased again in tests conducted in June 1995, regardless of sperm collection method. Increased variability in response to zinc may be caused by seasonal temperature effects.

  10. Anthocyanin accumulation and transcriptional regulation of anthocyanin biosynthesis in purple bok choy (Brassica rapa var. chinensis).

    PubMed

    Zhang, Yanjie; Chen, Guoping; Dong, Tingting; Pan, Yu; Zhao, Zhiping; Tian, Shibing; Hu, Zongli

    2014-12-24

    Bok choy (Brassica rapa var. chinensis) is an important dietary vegetable cultivated and consumed worldwide for its edible leaves. The purple cultivars rich in health-promoting anthocyanins are usually more eye-catching and valuable. Fifteen kinds of anthocyanins were separated and identified from a purple bok choy cultivar (Zi He) by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. To investigate the molecular mechanisms underlying anthocyanin accumulation in bok choy, the expression profiles of anthocyanin biosynthetic and regulatory genes were analyzed in seedlings and leaves of the purple cultivar and the green cultivar (Su Zhouqing). Compared with the other tissues, BrTT8 and most of the anthocyanin biosynthetic genes were significantly up-regulated in the leaves and light-grown seedlings of Zi He. The results that heterologous expression of BrTT8 promotes the transcription of partial anthocyanin biosynthetic genes in regeneration shoots of tomato indicate that BrTT8 plays an important role in the regulation of anthocyanin biosynthesis. PMID:25419600

  11. Characterization of Bacterial Communities Associated with the Tyrian Purple Producing Gland in a Marine Gastropod.

    PubMed

    Ngangbam, Ajit Kumar; Baten, Abdul; Waters, Daniel L E; Whalan, Steve; Benkendorff, Kirsten

    2015-01-01

    Dicathais orbita is a marine mollusc recognised for the production of anticancer compounds that are precursors to Tyrian purple. This study aimed to assess the diversity and identity of bacteria associated with the Tyrian purple producing hypobranchial gland, in comparison with foot tissue, using a high-throughput sequencing approach. Taxonomic and phylogenetic analysis of variable region V1-V3 of 16S rRNA bacterial gene amplicons in QIIME and MEGAN were carried out. This analysis revealed a highly diverse bacterial assemblage associated with the hypobranchial gland and foot tissues of D. orbita. The dominant bacterial phylum in the 16S rRNA bacterial profiling data set was Proteobacteria followed by Bacteroidetes, Tenericutes and Spirochaetes. In comparison to the foot, the hypobranchial gland had significantly lower bacterial diversity and a different community composition, based on taxonomic assignment at the genus level. A higher abundance of indole producing Vibrio spp. and the presence of bacteria with brominating capabilities in the hypobranchial gland suggest bacteria have a potential role in biosynthesis of Tyrian purple in D. orbita. PMID:26488885

  12. Membrane stabilizer

    DOEpatents

    Mingenbach, W.A.

    1988-02-09

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material. 10 figs.

  13. Tube Fragmentation of Multiple Materials

    SciTech Connect

    Thornhill, T. F.; Chhabildas, L. C.; Vogler, T. J.

    2006-07-28

    In the current study we are developing an experimental fracture material property test method specific to dynamic fragmentation. This test method allows the study of fracture fragmentation in a reproducible laboratory environment under well-controlled loading conditions. Motion and fragmentation of the specimen are diagnosed using framing camera, VISAR and soft recovery methods. Fragmentation properties of several steels, nitinol, tungsten alloy, copper, aluminum, and titanium have been obtained to date. The values for fragmentation toughness, and failure threshold will be reported, as well as effects in these values as the material strain-rate is varied through changes in wall thickness and impact conditions.

  14. Tube fragmentation of multiple materials.

    SciTech Connect

    Thornhill, Tom Finley, III; Vogler, Tracy John; Chhabildas, Lalit Chandra

    2003-07-01

    In the current study we are developing an experimental fracture material property test method specific to dynamic fragmentation. This test method allows the study of fracture fragmentation in a reproducible laboratory environment under well-controlled loading conditions. Motion and fragmentation of the specimen are diagnosed using framing camera, VISAR and soft recovery methods. Fragmentation properties of several steels, nitinol, tungsten alloy, copper, aluminum, and titanium have been obtained to date. The values for fragmentation toughness, and failure threshold will be reported, as well as effects in these values as the material strain-rate is varied through changes in wall thickness and impact conditions.

  15. New Scalings in Nuclear Fragmentation

    SciTech Connect

    Bonnet, E.; Bougault, R.; Galichet, E.; Gagnon-Moisan, F.; Guinet, D.; Lautesse, P.; Marini, P.; Parlog, M.

    2010-10-01

    Fragment partitions of fragmenting hot nuclei produced in central and semiperipheral collisions have been compared in the excitation energy region 4-10 MeV per nucleon where radial collective expansion takes place. It is shown that, for a given total excitation energy per nucleon, the amount of radial collective energy fixes the mean fragment multiplicity. It is also shown that, at a given total excitation energy per nucleon, the different properties of fragment partitions are completely determined by the reduced fragment multiplicity (i.e., normalized to the source size). Freeze-out volumes seem to play a role in the scalings observed.

  16. Peripheral Light-Harvesting LH2 Complex Can Be Assembled in Cells of Nonsulfur Purple Bacterium Rhodoblastus acidophilus without Carotenoids.

    PubMed

    Bol'shakov, M A; Ashikhmin, A A; Makhneva, Z K; Moskalenko, A A

    2015-09-01

    The effect of carotenoids on the assembly of LH2 complex in cells of the purple nonsulfur bacterium Rhodoblastus acidophilus was investigated. For this purpose, the bacterial culture was cultivated with an inhibitor of carotenoid biosynthesis - 71 µM diphenylamine (DPA). The inhibitor decreased the level of biosynthesis of the colored carotenoids in membranes by ~58%. It was found that a large amount of phytoene was accumulated in them. This carotenoid precursor was bound nonspecifically to LH2 complex and did not stabilize its structure. Thermostability testing of the isolated LH2 complex together with analysis of carotenoid composition revealed that the population of this complex was heterogeneous with respect to carotenoid composition. One fraction of the LH2 complex with carotenoid content around 90% remains stable and was not destroyed under heating for 15 min at 50°C. The other fraction of LH2 complex containing on average less than one molecule of carotenoid per complex was destroyed under heating, forming a zone of free pigments (and polypeptides). The data suggest that a certain part of the LH2 complexes is assembled without carotenoids in cells of the nonsulfur bacterium Rbl. acidophilus grown with DPA. These data contradict the fact that the LH2 complex from nonsulfur bacteria cannot be assembled without carotenoids, but on the other hand, they are in good agreement with the results demonstrated in our earlier studies of the sulfur bacteria Allochromatium minutissimum and Ectothiorhodospira haloalkaliphila. Carotenoidless LH2 complex was obtained from these bacteria with the use of DPA (Moskalenko, A. A., and Makhneva, Z. K. (2012) J. Photochem. Photobiol., 108, 1-7; Ashikhmin, A., et al. (2014) Photosynth. Res., 119, 291-303). PMID:26555469

  17. Photovoltage kinetics of the acid-blue and acid-purple forms of bacteriorhodopsin: evidence for no net charge transfer.

    PubMed Central

    Moltke, S; Heyn, M P

    1995-01-01

    Time-resolved photovoltage measurements were performed with the acid-blue (bR605A) and acid-purple (bR565A) forms of bacteriorhodopsin (bR) in the time range from 25 ns to 100 s. The bR605A and bR565A pigments were formed by titration with H2SO4 in the absence and presence of 150 mM KCI, respectively. Qualitatively the kinetics of the charge displacement in these two states are similar and consist of two fast phases in one direction (100 ns bandwidth limited and approximately 1 microsecond) followed by a decay in the opposite direction via one component for bR605A (4.4 +/- 0.6 ms) or two components for bR565A (33 +/- 8 microseconds and 3.6 +/- 0.5 ms). The transient photovoltage signal returns exactly to the initial value after several milliseconds, well before the passive discharge of the electrical measuring system at 2 s. We conclude that no net charge transfer occurs in either bR605A or bR565A. The direction of the fast components is opposite that of net proton translocation in bR at pH 7. So, if the charge that moves back and forth is due to a proton, it moves first in the direction of the cytoplasmic side of the membrane (< 1 microsecond) and returns to its initial position via the 4.4 ms (bR605A) or the 33 microseconds and 3.6 ms (bR565A) decay components. The amplitude of the charge motion in both low pH forms is too large to be due to isomerization alone and is comparable to one of the major components in bR at pH 7.2 PMID:8580350

  18. Scaling behavior of fragment shapes.

    PubMed

    Kun, F; Wittel, F K; Herrmann, H J; Kröplin, B H; Måløy, K J

    2006-01-20

    We present an experimental and theoretical study of the shape of fragments generated by explosive and impact loading of closed shells. Based on high speed imaging, we have determined the fragmentation mechanism of shells. Experiments have shown that the fragments vary from completely isotropic to highly anisotropic elongated shapes, depending on the microscopic cracking mechanism of the shell. Anisotropic fragments proved to have a self-affine character described by a scaling exponent. The distribution of fragment shapes exhibits a power-law decay. The robustness of the scaling laws is illustrated by a stochastic hierarchical model of fragmentation. Our results provide a possible improvement of the representation of fragment shapes in models of space debris. PMID:16486594

  19. Fragment Screening of Human Aquaporin 1

    PubMed Central

    To, Janet; Torres, Jaume

    2016-01-01

    Aquaporins (AQPs) are membrane proteins that enable water transport across cellular plasma membranes in response to osmotic gradients. Phenotypic analyses have revealed important physiological roles for AQPs, and the potential for AQP water channel modulators in various disease states has been proposed. For example, AQP1 is overexpressed in tumor microvessels, and this correlates with higher metastatic potential and aggressiveness of the malignancy. Chemical modulators would help in identifying the precise contribution of water channel activity in these disease states. These inhibitors would also be important therapeutically, e.g., in anti-cancer treatment. This perceived importance contrasts with the lack of success of high-throughput screens (HTS) to identify effective and specific inhibitors of aquaporins. In this paper, we have screened a library of 1500 “fragments”, i.e., smaller than molecules used in HTS, against human aquaporin (hAQP1) using a thermal shift assay and surface plasmon resonance. Although these fragments may not inhibit their protein target, they bound to and stabilized hAQP1 (sub mM binding affinities (KD), with an temperature of aggregation shift ΔTagg of +4 to +50 °C) in a concentration-dependent fashion. Chemically expanded versions of these fragments should follow the determination of their binding site on the aquaporin surface. PMID:27023529

  20. Temperature-dependent phase transitions of a complex biological membrane in zeptoliter volumes

    SciTech Connect

    Nikiforov, Maxim; Hohlbauch, Sophia; King, William P; Voitchovsky, K; Contera, S Antoranz; Jesse, Stephen; Kalinin, Sergei V; Proksch, Roger

    2011-01-01

    Phase transitions in purple membrane have been a topic of debate for the past two decades. In this work we present studies of a reversible transition of purple membrane in the 50 60 C range in zeptoliter volumes under different heating regimes (global heating and local heating). The temperature of the reversible phase transition is 52 5 C for both local and global heating, supporting the hypothesis that this transition is mainly due to a structural rearrangement of bR molecules and trimers. To achieve high resolution measurements of temperature-dependent phase transitions, a new scanning probe microscopy-based method was developed. We believe that our new technique can be extended to other biological systems and can contribute to the understanding of inhomogeneous phase transitions in complex systems.

  1. Fragment oriented molecular shapes.

    PubMed

    Hain, Ethan; Camacho, Carlos J; Koes, David Ryan

    2016-05-01

    Molecular shape is an important concept in drug design and virtual screening. Shape similarity typically uses either alignment methods, which dynamically optimize molecular poses with respect to the query molecular shape, or feature vector methods, which are computationally less demanding but less accurate. The computational cost of alignment can be reduced by pre-aligning shapes, as is done with the Volumetric-Aligned Molecular Shapes (VAMS) method. Here, we introduce and evaluate fragment oriented molecular shapes (FOMS), where shapes are aligned based on molecular fragments. FOMS enables the use of shape constraints, a novel method for precisely specifying molecular shape queries that provides the ability to perform partial shape matching and supports search algorithms that function on an interactive time scale. When evaluated using the challenging Maximum Unbiased Validation dataset, shape constraints were able to extract significantly enriched subsets of compounds for the majority of targets, and FOMS matched or exceeded the performance of both VAMS and an optimizing alignment method of shape similarity search. PMID:27085751

  2. Fibril Fragmentation Enhances Amyloid Cytotoxicity*♦

    PubMed Central

    Xue, Wei-Feng; Hellewell, Andrew L.; Gosal, Walraj S.; Homans, Steve W.; Hewitt, Eric W.; Radford, Sheena E.

    2009-01-01

    Fibrils associated with amyloid disease are molecular assemblies of key biological importance, yet how cells respond to the presence of amyloid remains unclear. Cellular responses may not only depend on the chemical composition or molecular properties of the amyloid fibrils, but their physical attributes such as length, width, or surface area may also play important roles. Here, we report a systematic investigation of the effect of fragmentation on the structural and biological properties of amyloid fibrils. In addition to the expected relationship between fragmentation and the ability to seed, we show a striking finding that fibril length correlates with the ability to disrupt membranes and to reduce cell viability. Thus, despite otherwise unchanged molecular architecture, shorter fibrillar samples show enhanced cytotoxic potential than their longer counterparts. The results highlight the importance of fibril length in amyloid disease, with fragmentation not only providing a mechanism by which fibril load can be rapidly increased but also creating fibrillar species of different dimensions that can endow new or enhanced biological properties such as amyloid cytotoxicity. PMID:19808677

  3. Association of a new type of gliding, filamentous, purple phototrophic bacterium inside bundles of Microcoleus chthonoplastes in hypersaline cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    D'Amelio, E. D.; Cohen, Y.; Des Marais, D. J.

    1987-01-01

    An unidentified filamentous purple bacterium, probably belonging to a new genus or even a new family, is found in close association with the filamentous, mat-forming cyanobacterium Microcoleus chthonoplastes in a hypersaline pond at Guerrero Negro, Baja California Sur, Mexico, and in Solar Lake, Sinai, Egypt. This organism is a gliding, segmented trichome, 0.8-0.9 micrometer wide. It contains intracytoplasmic stacked lamellae which are perpendicular and obliquely oriented to the cell wall, similar to those described for the purple sulfur bacteria Ectothiorhodospira. These bacteria are found inside the cyanobacterial bundle, enclosed by the cyanobacterial sheath. Detailed transmission electron microscopical analyses carried out in horizontal sections of the upper 1.5 mm of the cyanobacterial mat show this cyanobacterial-purple bacterial association at depths of 300-1200 micrometers, corresponding to the zone below that of maximal oxygenic photosynthesis. Sharp gradients of oxygen and sulfide are established during the day at this microzone in the two cyanobacterial mats studied. The close association, the distribution pattern of this association and preliminary physiological experiments suggest a co-metabolism of sulfur by the two-membered community. This probable new genus of purple bacteria may also grow photoheterotrophically using organic carbon excreted by the cyanobacterium. Since the chemical gradients in the entire photic zone fluctuate widely in a diurnal cycle, both types of metabolism probably take place. During the morning and afternoon, sulfide migrates up to the photic zone allowing photoautotrophic metabolism with sulfide as the electron donor. During the day the photic zone is highly oxygenated and the purple bacteria may either use oxidized species of sulfur such as elemental sulfur and thiosulfate in the photoautotrophic mode or grow photoheterotrophically using organic carbon excreted by M. chthonoplastes. The new type of filamentous purple sulfur

  4. Membrane tension and membrane fusion.

    PubMed

    Kozlov, Michael M; Chernomordik, Leonid V

    2015-08-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually large membrane tensions or, alternatively, low line tensions of the pore resulting from accumulation in the pore rim of membrane-bending proteins. Increase of the inter-membrane distance facilitates the reaction. PMID:26282924

  5. Membrane tethering

    PubMed Central

    Chia, Pei Zhi Cheryl

    2014-01-01

    Membrane trafficking depends on transport vesicles and carriers docking and fusing with the target organelle for the delivery of cargo. Membrane tethers and small guanosine triphosphatases (GTPases) mediate the docking of transport vesicles/carriers to enhance the efficiency of the subsequent SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-mediated fusion event with the target membrane bilayer. Different classes of membrane tethers and their specific intracellular location throughout the endomembrane system are now well defined. Recent biochemical and structural studies have led to a deeper understanding of the mechanism by which membrane tethers mediate docking of membrane carriers as well as an appreciation of the role of tethers in coordinating the correct SNARE complex and in regulating the organization of membrane compartments. This review will summarize the properties and roles of membrane tethers of both secretory and endocytic systems. PMID:25343031

  6. Chapter 4 embedded metal fragments.

    PubMed

    Kalinich, John F; Vane, Elizabeth A; Centeno, Jose A; Gaitens, Joanna M; Squibb, Katherine S; McDiarmid, Melissa A; Kasper, Christine E

    2014-01-01

    The continued evolution of military munitions and armor on the battlefield, as well as the insurgent use of improvised explosive devices, has led to embedded fragment wounds containing metal and metal mixtures whose long-term toxicologic and carcinogenic properties are not as yet known. Advances in medical care have greatly increased the survival from these types of injuries. Standard surgical guidelines suggest leaving embedded fragments in place, thus individuals may carry these retained metal fragments for the rest of their lives. Nursing professionals will be at the forefront in caring for these wounded individuals, both immediately after the trauma and during the healing and rehabilitation process. Therefore, an understanding of the potential health effects of embedded metal fragment wounds is essential. This review will explore the history of embedded fragment wounds, current research in the field, and Department of Defense and Department of Veterans Affairs guidelines for the identification and long-term monitoring of individuals with embedded fragments. PMID:25222538

  7. Effects of Feeding Purple Rice (Oryza sativa L. Var. Glutinosa) on the Quality of Pork and Pork Products

    PubMed Central

    Jaturasitha, Sanchai; Ratanapradit, Punnares; Piawong, Witapong; Kreuzer, Michael

    2016-01-01

    Purple rice is a strain of glutaneous rice rich in anthocyanins and γ-oryzanol. Both types of compounds are involved in antioxidant and lipid metabolism of mammals. Three experimental diet types were used which consisted approximately by half either of purple rice, white rice or corn. Diets were fed to 3×10 pigs growing from about 30 to 100 kg. Meat samples were investigated either as raw or cured loin chops or as smoked bacon produced from the belly. Various physicochemical traits were assessed and data were evaluated by analysis of variance. Traits describing water-holding capacity (drip, thaw, and cooking losses) and tenderness (sensory grading, shear force) of the meat were mostly not significantly affected by the diet type. However, purple rice feeding of pigs resulted in lower fat and cholesterol contents of loin and smoked bacon compared to white rice, but not compared to corn feeding except of the fat content of the loin. The shelf life of the raw loin chops was improved by purple rice as well. In detail, the occurrence of thiobarbituric acid reactive substances after 9 days of chilled storage was three to four times higher in the white rice and corn diets than with purple rice. The n-6:n-3 ratio in the raw loin chops was 9:1 with purple rice and clearly higher with 12:1 with the other diets, meat lipids. Level and kind of effect of purple rice found in raw meat was not always recovered in the cured loin chops and the smoked bacon. Still the impression of flavor and color, as well as overall acceptability were best in the smoked bacon from the purple-rice fed pigs, whereas this effect did not occur in the cured loin chops. These findings suggest that purple rice has a certain, useful, bioactivity in pigs concerning meat quality, but some of these effects are of low practical relevance. Further studies have to show ways how transiency and low recovery in meat products of some of the effects can be counteracted. PMID:26949957

  8. Effects of Feeding Purple Rice (Oryza sativa L. Var. Glutinosa) on the Quality of Pork and Pork Products.

    PubMed

    Jaturasitha, Sanchai; Ratanapradit, Punnares; Piawong, Witapong; Kreuzer, Michael

    2016-04-01

    Purple rice is a strain of glutaneous rice rich in anthocyanins and γ-oryzanol. Both types of compounds are involved in antioxidant and lipid metabolism of mammals. Three experimental diet types were used which consisted approximately by half either of purple rice, white rice or corn. Diets were fed to 3×10 pigs growing from about 30 to 100 kg. Meat samples were investigated either as raw or cured loin chops or as smoked bacon produced from the belly. Various physicochemical traits were assessed and data were evaluated by analysis of variance. Traits describing water-holding capacity (drip, thaw, and cooking losses) and tenderness (sensory grading, shear force) of the meat were mostly not significantly affected by the diet type. However, purple rice feeding of pigs resulted in lower fat and cholesterol contents of loin and smoked bacon compared to white rice, but not compared to corn feeding except of the fat content of the loin. The shelf life of the raw loin chops was improved by purple rice as well. In detail, the occurrence of thiobarbituric acid reactive substances after 9 days of chilled storage was three to four times higher in the white rice and corn diets than with purple rice. The n-6:n-3 ratio in the raw loin chops was 9:1 with purple rice and clearly higher with 12:1 with the other diets, meat lipids. Level and kind of effect of purple rice found in raw meat was not always recovered in the cured loin chops and the smoked bacon. Still the impression of flavor and color, as well as overall acceptability were best in the smoked bacon from the purple-rice fed pigs, whereas this effect did not occur in the cured loin chops. These findings suggest that purple rice has a certain, useful, bioactivity in pigs concerning meat quality, but some of these effects are of low practical relevance. Further studies have to show ways how transiency and low recovery in meat products of some of the effects can be counteracted. PMID:26949957

  9. [Influence of Three Low-Molecular-Weight Organic Acids on the Adsorption of Phenanthrene in Purple Soil].

    PubMed

    Xie, Li; Chen, Ben-shou; Zhang, Jin-zhong; Lu, Song; Jiang, Tao

    2016-03-15

    The effects of three low-molecular-weight organic acids (citric acid, malic acid and oxalic acid) on the adsorption of phenanthrene in purple soil were studied by static adsorption experiment. The results showed that the adsorption kinetic process of phenanthrene in purple soil could be described by the second-order kinetic model, and the adsorption rate constant would significantly decrease in the presence of the three low-molecular-weight organic acids ( LMWOAs). The adsorption thermodynamic process could be well described by linear adsorption model, which was dominated by distribution role. The three LMWOAs could promote the adsorption of phenantherene in purple soil when their concentrations were less than 5 mmol · L⁻¹, whereas inhibit the adsorption when their concentrations were more than 10 mmol · L⁻¹, and the inhibition would increase with increasing concentrations. Moreover, the inhibitory ability displayed a decreasing order of citric acid, oxalic acid, and malic acid when their concentrations were 20 mmol · L⁻¹, which is related to the molecular structure and acidity of the three LMWOAs. Compared with the control, the content of dissolved organic matter (DOM) released from purple soil showed a trend of first decrease and then increase with increasing LMWOAs concentration, and the adsorption capacity of phenanthrene in purple soil was negatively related to DOM content. PMID:27337897

  10. Microbial community in microbial fuel cell (MFC) medium and effluent enriched with purple photosynthetic bacterium (Rhodopseudomonas sp.)

    PubMed Central

    2014-01-01

    High power densities have been obtained from MFC reactors having a purple color characteristic of Rhodopseudomonas. We investigated the microbial community structure and population in developed purple MFC medium (DPMM) and MFC effluent (DPME) using 16S rRNA pyrosequencing. In DPMM, dominant bacteria were Comamonas (44.6%), Rhodopseudomonas (19.5%) and Pseudomonas (17.2%). The bacterial community of DPME mainly consisted of bacteria related to Rhodopseudomonas (72.2%). Hydrogen oxidizing bacteria were identified in both purple-colored samples: Hydrogenophaga and Sphaerochaeta in the DPMM, and Arcobacter, unclassified Ignavibacteriaceae, Acinetobacter, Desulfovibrio and Wolinella in the DPME. The methanogenic community of both purple-colored samples was dominated by hydrogenotrophic methanogens including Methanobacterium, Methanobrevibacter and Methanocorpusculum with significantly lower numbers of Methanosarcina. These results suggeste that hydrogen is actively produced by Rhodopseudomonas that leads to the dominance of hydrogen consuming microorganisms in both purple-colored samples. The syntrophic relationship between Rhodopseudomonas and hydrogenotrophic microbes might be important for producing high power density in the acetate-fed MFC under light conditions. PMID:24949257

  11. Physical and chemical characteristics of golden-yellow and purple-red varieties of tamarillo fruit (Solanum betaceum Cav.).

    PubMed

    Vasco, Catalina; Avila, Jenny; Ruales, Jenny; Svanberg, Ulf; Kamal-Eldin, Afaf

    2009-01-01

    Golden-yellow and purple-red tamarillos (Solanum betaceum Cav.) cultivated in Ecuador were studied for their physical properties, proximate composition, pH, degrees Brix, acidity, sugars, organic acids, minerals, vitamin C and beta-carotene content in the edible part. Results were compared with those for Spanish fruits. The golden-yellow and purple-red Ecuadorian fruits were larger (107 and 188 g) than the respective Spanish fruits (43 and 63 g), softer but generally similar in chemical composition except for fat (0.72 and 0.6%) and malic acid (0.32 and 0.53%) contents in the golden-yellow and purple-red Ecuadorian fruits. Tamarillo fruits are a good source of potassium (approximately 400 mg/100 g fresh weight). Total phenolics in the golden-yellow and purple-red varieties were 125 and 187 mg gallic acid equivalents/100 g fresh weight, respectively. The golden-yellow variety had weaker anti-DPPH radical activity than the purple-red variety. Flavonols were only found in the peel of both varieties, while hydroxycinnamic acid derivatives were found in peel and pulp. PMID:19657848

  12. Soluble and bound phenolic compounds in different Bolivian purple corn ( Zea mays L.) cultivars.

    PubMed

    Cuevas Montilla, Elyana; Hillebrand, Silke; Antezana, Amalia; Winterhalter, Peter

    2011-07-13

    In nine Bolivian purple corn ( Zea mays L.) varieties the content of phenolic compounds as well as the anthocyanin composition has been determined. The phenotypes under investigation included four red and five blue varieties (Kulli, Ayzuma, Paru, Tuimuru, Oke, Huaca Songo, Colorado, Huillcaparu, and Checchi). In purple corn, phenolic compounds were highly concentrated in cell walls. Thus, simultaneous determination of soluble and bound-form phenolics is essential for analysis, extraction, and quantification. The present study reports the determination of soluble and insoluble-bound fraction of phenolic compounds by HPLC-DAD and HPLC-ESI-MS(n) in Bolivian purple corn varieties. Enzymatic, thermal, and alkaline hydrolyses were used to obtain the cell wall-linked phenolic compounds. Ferulic acid values ranged from 132.9 to 298.4 mg/100 g, and p-coumaric acid contents varied between 251.8 and 607.5 mg/100 g dry weight (DW), respectively, and were identified as the main nonanthocyanin phenolics. The total content of phenolic compounds ranged from 311.0 to 817.6 mg gallic acid equivalents (GAE)/100 g DW, and the percentage contribution of bound to total phenolics varied from 62.1 to 86.6%. The total monomeric anthocyanin content ranged from 1.9 to 71.7 mg cyanidin-3-glucoside equivalents/100 g DW. Anthocyanin profiles are almost the same among the different samples. Differences are observed only in the relative percentage of each anthocyanin. Cyanidin-3-glucoside and its malonated derivative were detected as major anthocyanins. Several dimalonylated monoglucosides of cyanidin, peonidin, and pelargonidin were present as minor constituents. PMID:21639140

  13. Phenytoin-Induced Purple Glove Syndrome: A Case Report and Review of the Literature

    PubMed Central

    Okogbaa, John I.; Arije, Oluwatoyin A.; Harris, Martha B.; Lillis, Rebecca A.

    2015-01-01

    Objective: To present a case report and literature review of phenytoin-induced purple glove syndrome (PGS). Case summary: A 54-year-old African American male presented to our hospital’s emergency department (ED) following a seizure episode, cardiac arrest, and loss of consciousness. On arrival to the ED, the patient’s total phenytoin level was subtherapeutic at 4.1 mcg/mL and his corrected total phenytoin level was subtherapeutic at 5.1 mcg/mL. In the ED, the patient received a loading dose of intravenous (IV) phenytoin 1,000 mg once via the left cephalic vein, at a rate of 50 mg/min, and was admitted to the medicine service. A day following IV phenytoin administration, a nurse noticed an IV fluid infiltration on the skin tissue around the left cephalic vein. The area appeared dark blue and purple in color, swollen, erythematous, and warm to touch. An ultrasound of the left upper extremity was performed and revealed subcutaneous fluid collection without evidence of thrombosis. Discussion: The Naranjo Adverse Drug Reaction Probability Scale assigned a score of 7, indicating phenytoin as the probable cause of purple glove syndrome (PGS). The patient’s PGS was managed with a combination of dry dressing material, left forearm elevation, collagenase topical cream, 0.1% IV bupivacaine, and IV fentanyl. The patient’s injury was resolving at the time of discharge to a rehabilitation facility. Conclusion: PGS is a rare complication of IV phenytoin therapy. The risk of PGS for this patient may have been abated by decreasing the phenytoin infusion rate from 50 mg/min to less than 25 mg/min. PMID:26405326

  14. Response Characteristics of Soil Fractal Features to Different Land Uses in Typical Purple Soil Watershed

    PubMed Central

    Luo, Bang-lin; Chen, Xiao-yan; Ding, Lin-qiao; Huang, Yu-han; Zhou, Ji; Yang, Tian-tian

    2015-01-01

    As a fundamental characteristic of soil physical properties, the soil Particle Size Distribution (PSD) is important in the research on soil moisture migration, solution transformation, and soil erosion. In this research, the PSD characteristics with distinct methods in different land uses are analyzed. The results show that the upper bound of the volume domain of the clay domain ranges from 5.743μm to 5.749μm for all land-use types. For the silt domain of purple soil, the value ranges among 286.852~286.966 μm. For all purple soil land-use types, the order of the volume domain fractal dimensions is DclayDsilt(U)>Dsand (U)>Dsand and Dsilt>Dsilt(U)>Dsand>Dsand(U), respectively. As it is compared with all Dvi, the Dsilt has the most significant correlativity to the soil texture and organic matter in different land uses of the typical purple soil watersheds. Therefore, Dsilt will be a potential indictor for evaluating the proportion of fine particles in the PSD, as well as a key measurement in soil quality and productivity studies. PMID:25856376

  15. Response characteristics of soil fractal features to different land uses in typical purple soil watershed.

    PubMed

    Luo, Bang-lin; Chen, Xiao-yan; Ding, Lin-qiao; Huang, Yu-han; Zhou, Ji; Yang, Tian-tian

    2015-01-01

    As a fundamental characteristic of soil physical properties, the soil Particle Size Distribution (PSD) is important in the research on soil moisture migration, solution transformation, and soil erosion. In this research, the PSD characteristics with distinct methods in different land uses are analyzed. The results show that the upper bound of the volume domain of the clay domain ranges from 5.743 μm to 5.749 μm for all land-use types. For the silt domain of purple soil, the value ranges among 286.852~286.966 μm. For all purple soil land-use types, the order of the volume domain fractal dimensions is D clayD silt(U)>D sand (U)>D sand and D silt>D silt(U)>D sand>D sand(U), respectively. As it is compared with all Dvi, the D silt has the most significant correlativity to the soil texture and organic matter in different land uses of the typical purple soil watersheds. Therefore, Dsilt will be a potential indictor for evaluating the proportion of fine particles in the PSD, as well as a key measurement in soil quality and productivity studies. PMID:25856376

  16. Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method.

    PubMed

    Shrestha, Kushal; Jakubikova, Elena

    2015-08-20

    Light-harvesting antennas are protein-pigment complexes that play a crucial role in natural photosynthesis. The antenna complexes absorb light and transfer energy to photosynthetic reaction centers where charge separation occurs. This work focuses on computational studies of the electronic structure of the pigment networks of light-harvesting complex I (LH1), LH1 with the reaction center (RC-LH1), and light-harvesting complex II (LH2) found in purple bacteria. As the pigment networks of LH1, RC-LH1, and LH2 contain thousands of atoms, conventional density functional theory (DFT) and ab initio calculations of these systems are not computationally feasible. Therefore, we utilize DFT in conjunction with the energy-based fragmentation with molecular orbitals method and a semiempirical approach employing the extended Hückel model Hamiltonian to determine the electronic properties of these pigment assemblies. Our calculations provide a deeper understanding of the electronic structure of natural light-harvesting complexes, especially their pigment networks, which could assist in rational design of artificial photosynthetic devices. PMID:26215074

  17. Local measurements of phase transitions in Bacteriorhodopsin membrane

    NASA Astrophysics Data System (ADS)

    Proksch, R.; Nikiforov, M. P.; Hohlbauch, S.; King, W. P.; Antoraz Contera, S.; Voïtchovsky, K.; Kalinin, S. V.

    2010-03-01

    Phase transitions play an important role in biology. Specifically the thermodynamic stability of internal membrane proteins is an important issue of biophysics. Purple membrane from Halobacterium halobium contain bacteriorhodopsin (bR), an integral protein 70-80% of whole mass is intramembraneous. There are heated debates in the field about the parameters of thermal denaturation of bR, such as the denaturation temperature, enthalpy etc. Recently, bR was proposed as a component of biomolecular electronics. Thus, reliable information about the phase transitions of supported samples of bR membranes is necessary. Phase transitions in polymer/biopolymer materials are associated with the large changes in mechanical properties of the samples. We developed the technique for the measurements of the temperature dependence of the mechanical properties with high spatial resolution. This technique is based on the measurements of the contact stiffness of the atomic force microscopy tip -- sample system as a function of temperature.

  18. The functions of tryptophan residues in membrane proteins

    SciTech Connect

    Schiffer, M.; Chang, C.H.; Stevens, F.J.

    1994-08-01

    Membrane proteins in general have a significantly higher Trp content than do soluble proteins. This is especially true for the M and L subunits of the photosynthetic reaction center from purple bacteria. The Trp residues are located mostly in the segments that connect the transmembrane helices. Further, they are concentrated at the periplasmic side of the complex. Within the protein subunits, many form hydrogen bonds with carbonyl oxygens of the main chain, thereby stabilizing the protein. On the surface of the molecule, they are correctly positioned to form hydrogen bonds with the lipid head groups while their hydrophobic rings are immersed in the lipid part of the bilayer. We suggest that Trp residues are involved in the translocation of protein through the membrane and that following translocation, Trp residues serve as anchors on the periplasmic side of the membrane.

  19. Fluorescence enhancement of light-harvesting complex 2 from purple bacteria coupled to spherical gold nanoparticles

    SciTech Connect

    Bujak, Ł.; Czechowski, N.; Piatkowski, D.; Litvin, R.; Mackowski, S.; Brotosudarmo, T. H. P.; Pichler, S.; Cogdell, R. J.; Heiss, W.

    2011-10-24

    The influence of plasmon excitations in spherical gold nanoparticles on the optical properties of a light-harvesting complex 2 (LH2) from the purple bacteria Rhodopseudomonas palustris has been studied. Systematic analysis is facilitated by controlling the thickness of a silica layer between Au nanoparticles and LH2 complexes. Fluorescence of LH2 complexes features substantial increase when these complexes are separated by 12 nm from the gold nanoparticles. At shorter distances, non-radiative quenching leads to a decrease of fluorescence emission. The enhancement of fluorescence originates predominantly from an increase of absorption of pigments comprising the LH2 complex.

  20. Fluorescence enhancement of light-harvesting complex 2 from purple bacteria coupled to spherical gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Bujak, Ł.; Czechowski, N.; Piatkowski, D.; Litvin, R.; Mackowski, S.; Brotosudarmo, T. H. P.; Cogdell, R. J.; Pichler, S.; Heiss, W.

    2011-10-01

    The influence of plasmon excitations in spherical gold nanoparticles on the optical properties of a light-harvesting complex 2 (LH2) from the purple bacteria Rhodopseudomonas palustris has been studied. Systematic analysis is facilitated by controlling the thickness of a silica layer between Au nanoparticles and LH2 complexes. Fluorescence of LH2 complexes features substantial increase when these complexes are separated by 12 nm from the gold nanoparticles. At shorter distances, non-radiative quenching leads to a decrease of fluorescence emission. The enhancement of fluorescence originates predominantly from an increase of absorption of pigments comprising the LH2 complex.

  1. Efficiency of photochemical stages of photosynthesis in purple bacteria (a critical survey).

    PubMed

    Borisov, A Yu

    2014-03-01

    Based on currently available data, the energy transfer efficiency in the successive photophysical and photochemical stages has been analyzed for purple bacteria. This analysis covers the stages starting from migration of the light-induced electronic excitations from the bulk antenna pigments to the reaction centers up to irreversible stage of the electron transport along the transmembrane chain of cofactors-carriers. Some natural factors are revealed that significantly increase the rates of efficient processes in these stages. The influence on their efficiency by the "bottleneck" in the energy migration chain is established. The overall quantum yield of photosynthesis in these stages is determined. PMID:24821449

  2. Molecular Regulation of Photosynthetic Carbon Dioxide Fixation in Nonsulfur Purple Bacteria

    SciTech Connect

    Tabita, Fred Robert

    2015-12-01

    The overall objective of this project is to determine the mechanism by which a transcriptional activator protein affects CO2 fixation (cbb) gene expression in nonsulfur purple photosynthetic bacteria, with special emphasis to Rhodobacter sphaeroides and with comparison to Rhodopseudomonas palustris. These studies culminated in several publications which indicated that additional regulators interact with the master regulator CbbR in both R. sphaeroides and R. palustris. In addition, the interactive control of the carbon and nitrogen assimilatory pathways was studied and unique regulatory signals were discovered.

  3. Purple sea urchin Strongylocentrotus purpuratus gamete manipulation using optical trapping and microfluidics

    NASA Astrophysics Data System (ADS)

    Chandsawangbhuwana, Charlie; Shi, Linda Z.; Zhu, Qingyuan; Berns, Michael W.

    2013-04-01

    A system has been developed that allows for optical and fluidic manipulation of gametes. The optical manipulation is performed by using a single-point gradient trap with a 40× oil immersion PH3 1.3 NA objective on a Zeiss inverted microscope. The fluidic manipulation is performed by using a custom microfluidic chamber designed to fit into the short working distance between the condenser and objective. The system is validated using purple sea urchin Strongylocentrotus purpuratus gametes and has the potential to be used for mammalian in vitro fertilization and animal husbandry.

  4. Evaluation of Period of PURPLE Crying, an abusive head trauma prevention program.

    PubMed

    Reese, Laura Schwab; Heiden, Erin O; Kim, Kimberly Q; Yang, Jingzhen

    2014-01-01

    The Period of PURPLE Crying program is used to educate parents and caregivers about normal infant crying and the dangers of infant shaking. We evaluated nurse-led, hospital-based implementation of the program using a nonexperimental, posttest-only design. New mothers rated the program as useful, and the program was effective in teaching mothers about normal infant crying, the dangers of infant shaking, and soothing and coping techniques. The findings support the feasibility and need for broad dissemination of the program. PMID:25134950

  5. Potential Role for Purple Acid Phosphatase in the Dephosphorylation of Wall Proteins in Tobacco Cells1[W

    PubMed Central

    Kaida, Rumi; Serada, Satoshi; Norioka, Naoko; Norioka, Shigemi; Neumetzler, Lutz; Pauly, Markus; Sampedro, Javier; Zarra, Ignacio; Hayashi, Takahisa; Kaneko, Takako S.

    2010-01-01

    It is not yet known whether dephosphorylation of proteins catalyzed by phosphatases occurs in the apoplastic space. In this study, we found that tobacco (Nicotiana tabacum) purple acid phosphatase could dephosphorylate the phosphoryl residues of three apoplastic proteins, two of which were identified as α-xylosidase and β-glucosidase. The dephosphorylation and phosphorylation of recombinant α-xylosidase resulted in a decrease and an increase in its activity, respectively, when xyloglucan heptasaccharide was used as a substrate. Attempted overexpression of the tobacco purple acid phosphatase NtPAP12 in tobacco cells not only decreased the activity levels of the glycosidases but also increased levels of xyloglucan oligosaccharides and cello-oligosaccharides in the apoplast during the exponential phase. We suggest that purple acid phosphatase controls the activity of α-xylosidase and β-glucosidase, which are responsible for the degradation of xyloglucan oligosaccharides and cello-oligosaccharides in the cell walls. PMID:20357138

  6. Cyclocoelid ( Morishitium sp.) Trematodes from an Air Sac of a Purple Sandpiper, Calidris maritima (Brünnich).

    PubMed

    Shutler, Dave; Mallory, Mark L; Elderkin, Mark; McLaughlin, J Daniel

    2016-06-01

    Like many shorebirds, purple sandpipers ( Calidris maritima [Brünnich] Charadriiformes: Scolopacidae) have experienced population declines in recent years, but causes of these declines have not been established. As part of a larger study to identify causes of these declines, we collected and examined 25 purple sandpipers in coastal Nova Scotia, Canada during March 2013. In the course of dissections to collect tissue samples, we detected a cluster of trematodes in the air sac of 1 bird that were subsequently identified as cyclocoelids belonging to the genus Morishitium Witenberg, 1928, which we believe is the first report of this genus of parasites in this host. Cyclocoelids have been reported from other scolopacids and other shorebird families, but we are unaware of reports of serious pathology arising from these trematodes. Given this and the low prevalence (4%) in our sample, our data cannot ascribe declines in purple sandpiper populations to these trematodes, but our sample is limited both spatially and temporally. PMID:26779884

  7. Fragmentation pathways of polymer ions.

    PubMed

    Wesdemiotis, Chrys; Solak, Nilüfer; Polce, Michael J; Dabney, David E; Chaicharoen, Kittisak; Katzenmeyer, Bryan C

    2011-01-01

    Tandem mass spectrometry (MS/MS) is increasingly applied to synthetic polymers to characterize chain-end or in-chain substituents, distinguish isobaric and isomeric species, and determine macromolecular connectivities and architectures. For confident structural assignments, the fragmentation mechanisms of polymer ions must be understood, as they provide guidelines on how to deduce the desired information from the fragments observed in MS/MS spectra. This article reviews the fragmentation pathways of synthetic polymer ions that have been energized to decompose via collisionally activated dissociation (CAD), the most widely used activation method in polymer analysis. The compounds discussed encompass polystyrenes, poly(2-vinyl pyridine), polyacrylates, poly(vinyl acetate), aliphatic polyester copolymers, polyethers, and poly(dimethylsiloxane). For a number of these polymers, several substitution patterns and architectures are considered, and questions regarding the ionization agent and internal energy of the dissociating precursor ions are also addressed. Competing and consecutive dissociations are evaluated in terms of the structural insight they provide about the macromolecular structure. The fragmentation pathways of the diverse array of polymer ions examined fall into three categories, viz. (1) charge-directed fragmentations, (2) charge-remote rearrangements, and (3) charge-remote fragmentations via radical intermediates. Charge-remote processes predominate. Depending on the ionizing agent and the functional groups in the polymer, the incipient fragments arising by pathways (1)-(3) may form ion-molecule complexes that survive long enough to permit inter-fragment hydrogen atom, proton, or hydride transfers. PMID:20623599

  8. Proteomic analysis of thylakoid membranes.

    PubMed

    Yadavalli, Venkateswarlu; Nellaepalli, Sreedhar; Subramanyam, Rajagopal

    2011-01-01

    Chlamydomonas is a model organism to study photosynthesis. Thylakoid membranes comprise several proteins belonging to photosystems I and II. In this chapter, we show the accurate proteomic measurements in thylakoid membranes. The chlorophyll-containing membrane protein complexes were precipitated using chloroform/methanol solution. These complexes were separated using two-dimensional gel electrophoresis, and the resolved spots were exercised from the gel matrix and digested with trypsin. These peptide fragments were separated by MALDI-TOF, and the isotopic masses were blasted to a MASCOT server to obtain the protein sequence. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF). The method discussed here would be a useful method for the separation and identification of thylakoid membrane proteins. PMID:20960129

  9. Evaluation of organic and plastic mulches for purple nutsedge (Cyperus rotundus)suppression in a sustainable watermelon production system in Puerto Rico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experiment was conducted in Isabela, Puerto Rico, to determine the efficacy of eight organic mulches (dry shoots of millet, purple nutsedge, sunnhemp, sorghum, cowpea, cogongrass, bahiagrass, and rye) and two plastic mulches (black and IRT) to suppress purple nutsedge growth on the soil beds in a...

  10. Fragment-based drug design.

    PubMed

    Feyfant, Eric; Cross, Jason B; Paris, Kevin; Tsao, Désirée H H

    2011-01-01

    Fragment-based drug design (FBDD), which is comprised of both fragment screening and the use of fragment hits to design leads, began more than 15 years ago and has been steadily gaining in popularity and utility. Its origin lies on the fact that the coverage of chemical space and the binding efficiency of hits are directly related to the size of the compounds screened. Nevertheless, FBDD still faces challenges, among them developing fragment screening libraries that ensure optimal coverage of chemical space, physical properties and chemical tractability. Fragment screening also requires sensitive assays, often biophysical in nature, to detect weak binders. In this chapter we will introduce the technologies used to address these challenges and outline the experimental advantages that make FBDD one of the most popular new hit-to-lead process. PMID:20981527

  11. Toxicity, absorption, translocation, and metabolism of chlorimuron in yellow and purple nutsedge (Cyperus esculentus and C. rotundus)

    SciTech Connect

    Reddy, K.N.

    1987-01-01

    Greenhouse, laboratory, and field studies were conducted to investigate the activity of soil and foliar applied chlorimuron on yellow and purple nutsedge. Soil-applied chlorimuron (10 to 60 g/ha) significantly decreased tuber sprouting, shoot emergence, and shoot growth in both yellow and purple nutsedge. Previous exposure to soil-applied chlorimuron was not effective in reducing parent tuber sprouting at any rate in yellow nutsedge, while in purple nutsedge parent tuber sprouting was reduced significantly at 60 g/ha. Shoots of both yellow and purple nutsedge propagules absorbed greater amounts of /sup 14/C than did roots and tubers. However, translocation of /sup 14/C was greater from the roots and tuber than from the shoot. Toxicity of foliar-applied chlorimuron (5 to 30 g/ha) was evident by stunted growth, leaf discoloration, and death in both species. Application of chlorimuron at 20 g/ha gave 84% control in yellow nutsedge and 100% control in purple nutsedge. Chlorimuron treatments reduced shoot dry weight, inhibited secondary shoot production, and killed parent tubers attached to treated plants, regardless of rats, in both species. Over 13% of the foliar-applied /sup 14/C recovered was absorbed and over 15% of that absorbed was translocated at 1 day after application in both species. This increased two-fold by 8 days after application. /sup 14/C translocation was both acropetal and basipetal. Over 68% of the absorbed /sup 14/C in yellow nutsedge and 63% in purple nutsedge was retained in the treated area at 8 days after application. Overall, the basal bulb, rhizomes, and tuber had the least amounts of /sup 14/C in both species.

  12. Photoreversible conformational changes in membrane proteins using light-responsive surfactants.

    PubMed

    Zhang, Jing; Wang, Shao-Chun; Lee, C Ted

    2009-06-25

    Photoreversible control of the conformation of bacteriorhodopsin in the presence of a light-responsive surfactant is demonstrated through combined UV-vis, FT-IR, and (31)P NMR spectroscopy and dynamic light scattering (DLS) measurements. The azobenzene-based surfactant photoisomerizes upon 434 nm visible (trans, relatively hydrophobic) and 350 nm UV (cis, relatively hydrophilic) illumination, allowing surfactant micellization to be reversibly controlled. This leads to partitioning of the membrane protein into micelles in the unfolded state under visible light, while UV light leads to solubilization of the protein within purple membrane bilayers in the folded state. A three-stage model of purple membrane-photosurfactant interactions is examined through NMR and DLS measurements. Phototriggered unfolding of bacteriorhodopsin, occurring through alpha(II) --> alpha(I) and reverse beta-turn --> extended beta-strand transitions, requires approximately 20 s for completion, while light-induced refolding requires a somewhat longer 80 s as the membrane protein repartitions into the reformed bilayer membrane. Each of these conformational changes can be precisely and reversibly controlled with simple light illumination, providing a novel technique to probe membrane protein folding. PMID:19485396

  13. Elimination of 2,4,5,2',4',5'-hexachlorobiphenyl by the purple sea urchin, Strongylocentrotus purpuratus, following single exposure

    SciTech Connect

    Tjeerdema, R.S.; Jacobs, R.S.

    1987-06-01

    Understanding the fate of a single PCB isomer in a resident species may aid in assessing the risk to the marine community. Therefore, the elimination of 2,4,5,2',4',5'-hexachlorobiphenyl (HCBP) by the purple sea urchin, Strongylocentrotus purpuratus, following a single exposure, was investigated. The purple sea urchin was chosen because of its economic importance and ability to proliferate in certain polluted conditions. Single exposure may best mimic the effects of intermittent oceanic incineration or disposal, and 2,4,5,2',4',5'-HCBP was chosen due to its presence in common PCB mixtures and high chlorine content, thus strong lipophilicity.

  14. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Sadler, Mary E; Greiner, Anthony D; Aguinaldo, Jorge; Min, Kyungnan; Zhang, Kai; Arabi, Sara; Burbano, Marie S; Kent, Fraser; Shoaf, Robert

    2015-10-01

    This review, for literature published in 2014, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, fixed film and anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:26420079

  15. Membrane Processes.

    PubMed

    Pellegrin, Marie-Laure; Burbano, Marie S; Sadler, Mary E; Diamond, Jason; Baker, Simon; Greiner, Anthony D; Arabi, Sara; Wong, Joseph; Doody, Alexandra; Padhye, Lokesh P; Sears, Keith; Kistenmacher, Peter; Kent, Fraser; Tootchi, Leila; Aguinaldo, Jorge; Saddredini, Sara; Schilling, Bill; Min, Kyungnan; McCandless, Robert; Danker, Bryce; Gamage, Neranga P; Wang, Sunny; Aerts, Peter

    2016-10-01

    This review, for literature published in 2015, contains information related to membrane processes for municipal and industrial applications. This review is a subsection of the Treatment Systems section of the annual Water Environment Federation literature review and covers the following topics: pretreatment, membrane bioreactor (MBR) configuration, design, nutrient removal, operation, industrial treatment, anaerobic membrane systems, reuse, microconstituents removal, membrane technology advances, membrane fouling, and modeling. Other sub-sections of the Treatment Systems section that might relate to this literature review include: Biological Fixed-Film Systems, Activated Sludge and Other Aerobic Suspended Culture Processes, Anaerobic Processes, Water Reclamation and Reuse. The following sections might also have related information on membrane processes: Industrial Wastes, Hazardous Wastes, and Fate and Effects of Pollutants. PMID:27620084

  16. Multicomponent membranes

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    1988-01-01

    A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

  17. "Candidatus Phytoplasma americanum", a phytoplasma associated with a potato purple top wilt disease complex.

    PubMed

    Lee, Ing-Ming; Bottner, Kristi D; Secor, Gary; Rivera-Varas, Viviana

    2006-07-01

    Potato purple top wilt (PPT) is a devastating disease that occurs in various regions of North America and Mexico. At least three distinct phytoplasma strains belonging to three different phytoplasma groups (16SrI, 16SrII and 16SrVI) have been associated with this disease. A new disease with symptoms similar to PPT was recently observed in Texas and Nebraska, USA. Two distinct phytoplasma strain clusters were identified. One belongs to the 16SrI phytoplasma group, subgroup A, and the other is a novel phytoplasma that is most closely related to, and shares 96.6 % 16S rRNA gene sequence similarity with, a member of group 16SrXII. Phylogenetic analysis of 16S rRNA gene sequences of the novel PPT-associated phytoplasma strains, previously described 'Candidatus Phytoplasma' organisms and other distinct unnamed phytoplasmas indicated that the novel phytoplasma, termed American potato purple top wilt (APPTW) phytoplasma, represents a distinct lineage and shares a common ancestor with stolbur phytoplasma, "Candidatus Phytoplasma australiense", "Candidatus Phytoplasma japonicum", "Candidatus Phytoplasma fragariae", bindweed yellows phytoplasma (IBS), "Candidatus Phytoplasma caricae" and "Candidatus Phytoplasma graminis". On the basis of unique 16S rRNA gene sequences and biological properties, it is proposed that the APPTW phytoplasma represents "Candidatus Phytoplasma americanum", with APPTW12-NE as the reference strain. PMID:16825635

  18. A closer look at the feather coloration in the male purple sunbird, Nectarinia asiatica.

    PubMed

    Mahapatra, Biswa Bhusana; Marathe, Sandhya Amol; Meyer-Rochow, Victor Benno; Mishra, Monalisa

    2016-06-01

    During the breeding season male, but not female, individuals of the purple sunbird possess colourful plumage of chiefly blue and black coloration with a splatter of orange and yellow on the chest. Representative feathers of these colours were collected from male birds during the breeding season and analyzed by reflectance and scanning electron microscopy. The rachis, which is the central support of a feather on which various barbs and barbules are arranged, is spongy and made up of keratin layers with rod-shaped melanosomes sparsely distributed within these layers. Barbs and barbules are the structural units of the feather and depending on how they are arranged provide a characteristic shape to the feather. X-Ray diffraction (XRD) analyses of the feathers revealed the presence of various metal elements that might contribute to the feathers' colorations. Blue feathers are iridescent and contain mainly iron, copper, zinc and cobalt (in that order of abundance); black feathers were also found to contain mainly iron and copper, but chromium instead of zinc and cobalt, while yellow feathers were found to contain predominantly cobalt and nickel. The metal content of the feathers in an as yet unknown way may be involved in the production of the distinct absorbance and reflectance patterns that the brilliant plumage of the purple sunbird is renowned for. PMID:27088228

  19. Optimization conditions for anthocyanin and phenolic content extraction form purple sweet potato using response surface methodology.

    PubMed

    Ahmed, Maruf; Akter, Mst Sorifa; Eun, Jong-Bang

    2011-02-01

    Purple sweet potato flour could be used to enhance the bioactive components such as phenolic compounds and anthocyanin content that might be used as nutraceutical ingredients for formulated foods. Optimization of anthocyanin and phenolic contents of purple sweet potato were investigated using response surface methodology. A face-centered cube design was used to investigate the effects of three independent variables: namely, drying temperature 55-65°C, citric acid concentration 1-3% w/v and soaking time 1-3 min. The optimal conditions for anthocyanin and phenolic contents were 62.91°C, 1.38%, 2.53 min and 60.94°C, 1.04% and 2.24 min, respectively. However, optimal conditions of anthocyanin content were not apparent. The experimental value of anthocyanin content was 19.78 mg/100 g and total phenolic content was 61.55 mg/g. These data showed that the experimental responses were reasonably close to the predicted responses. Therefore, the results showed that treated flours could be used to enhance the antioxidant activities of functional foods. PMID:20858156

  20. Effects of growing conditions on purple corncob (Zea mays L.) anthocyanins.

    PubMed

    Jing, Pu; Noriega, Victor; Schwartz, Steven J; Giusti, M Mónica

    2007-10-17

    Purple corn ( Zea mays L.) has been used for centuries as a natural food colorant in South America and, more recently, in Asia and Europe. However, limited information is available on the factors affecting their anthocyanin concentration and profiles. In this study, 18 purple corn samples grown under different conditions in Peru were evaluated for quantitative and qualitative anthocyanin composition as well as total phenolics. High variability was observed on monomeric anthocyanin and phenolic contents with yields ranging from 290 to 1333 mg/100 g dry weight (DW) and from 950 to 3516 mg/100 g DW, respectively, while 30.5-47.1% of the total phenolics were anthocyanins. The major anthocyanins present were cyanidin-3-glucoside, pelargonidin-3-glucoside, peonidin-3-glucoside, cyanidin-3-maloylglucoside, pelargonidin-3-maloylglucoside, and peonidin-3-maloylglucoside, and 35.6-54.0% of the anthocyanins were acylated. Potassium sources/concentrations on the soil and seedling density did not significantly affect anthocyanin composition. The growing location affected anthocyanin levels and the percentage of anthocyanins to total phenolics ( p < 0.01) and should be taken into account when choosing a material for color production. PMID:17880157

  1. Methylation mediated by an anthocyanin, O-methyltransferase, is involved in purple flower coloration in Paeonia.

    PubMed

    Du, Hui; Wu, Jie; Ji, Kui-Xian; Zeng, Qing-Yin; Bhuiya, Mohammad-Wadud; Su, Shang; Shu, Qing-Yan; Ren, Hong-Xu; Liu, Zheng-An; Wang, Liang-Sheng

    2015-11-01

    Anthocyanins are major pigments in plants. Methylation plays a role in the diversity and stability of anthocyanins. However, the contribution of anthocyanin methylation to flower coloration is still unclear. We identified two homologous anthocyanin O-methyltransferase (AOMT) genes from purple-flowered (PsAOMT) and red-flowered (PtAOMT) Paeonia plants, and we performed functional analyses of the two genes in vitro and in vivo. The critical amino acids for AOMT catalytic activity were studied by site-directed mutagenesis. We showed that the recombinant proteins, PsAOMT and PtAOMT, had identical substrate preferences towards anthocyanins. The methylation activity of PsAOMT was 60 times higher than that of PtAOMT in vitro. Interestingly, this vast difference in catalytic activity appeared to result from a single amino acid residue substitution at position 87 (arginine to leucine). There were significant differences between the 35S::PsAOMT transgenic tobacco and control flowers in relation to their chromatic parameters, which further confirmed the function of PsAOMT in vivo. The expression levels of the two homologous AOMT genes were consistent with anthocyanin accumulation in petals. We conclude that AOMTs are responsible for the methylation of cyanidin glycosides in Paeonia plants and play an important role in purple coloration in Paeonia spp. PMID:26208646

  2. Effects of ultrasound treatment in purple cactus pear (Opuntia ficus-indica) juice.

    PubMed

    Zafra-Rojas, Quinatzin Yadira; Cruz-Cansino, Nelly; Ramírez-Moreno, Esther; Delgado-Olivares, Luis; Villanueva-Sánchez, Javier; Alanís-García, Ernesto

    2013-09-01

    Cactus pear (Opuntia ficus-indica) fruit is a berry with a tasty pulp full of seeds that constitutes about 10-15% of the edible pulp. In Mexico, cactus pear is mainly consumed fresh, but also has the potential to be processed in other products such as juice. The objective of this study was to evaluate the effect of different ultrasound conditions at amplitude levels ranging (40% and 60% for 10, 15, 25 min; 80% for 3, 5, 8, 10, 15 and 25 min) on the characteristics of purple cactus pear juice. The evaluated parameters were related with the quality (stability, °Brix, pH), microbial growth, total phenolic compounds, ascorbic acid and antioxidant activity (ABTS, DPPH and % chelating activity) of purple cactus pear juices. The ultrasound treatment for time period of 15 and 25 min significantly reduced the microbial count in 15 and 25 min, without affecting the juice quality and its antioxidant properties. Juice treated at 80% of amplitude level showed an increased of antioxidant compounds. Our results demonstrated that sonication is a suitable technique for cactus pear processing. This technology allows the achievement of juice safety and quality standards without compromising the retention of antioxidant compounds. PMID:23545106

  3. Characterisation and stability of anthocyanins in purple-fleshed sweet potato P40.

    PubMed

    Xu, Jianteng; Su, Xiaoyu; Lim, Soyoung; Griffin, Jason; Carey, Edward; Katz, Benjamin; Tomich, John; Smith, J Scott; Wang, Weiqun

    2015-11-01

    Purple-fleshed sweet potato P40 has been shown to prevent colorectal cancer in a murine model. This study is to identify anthocyanins by using HPLC/MS-MS and assess the stability during various cooking conditions. P40 possesses a high content of anthocyanins up to 14 mg/g dry matter. Total 12 acylated anthocyanins are identified. Top three anthocyanins, e.g., cyanidin 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside, peonidin 3-caffeoyl sophoroside-5-glucoside, and cyanidin 3-(6"-caffeoyl-6"-feruloylsophoroside)-5-glucoside, account for half of the anthocyanin contents. Over 80% of anthocyanins measured by acid hydrolysis were cyanidin derivatives, indicating P40 is unique when compared with other purple-fleshed sweet potatoes that usually contain more peonidin than cyanidin. Steaming, pressure cooking, microwaving, and frying but not baking significantly reduced 8-16% of total anthocyanin contents. Mono-acylated anthocyanins showed a higher resistance against heat than di- and non-acylated. Among of which, cyanidin 3-p-hydroxybenzoylsophoroside-5-glucoside exhibited the best thermal stability. The stable acylated and cyanidin-predominated anthocyanins in P40 may provide extra benefits for cancer prevention. PMID:25976796

  4. Purple potato (Solanum tuberosum L.) anthocyanins attenuate alcohol-induced hepatic injury by enhancing antioxidant defense.

    PubMed

    Jiang, Zhihui; Chen, Chen; Wang, Jian; Xie, Wenyan; Wang, Meng; Li, Xinsheng; Zhang, Xiaoying

    2016-01-01

    Alcoholic liver disease (ALD) is a serious and challenging health issue. In the past decade, natural components possessing hepatoprotective properties have gained more attention for ALD intervention. In this study, the phytochemical components of anthocyanins from purple potato were assessed using UPLC-MS/MS, and the hepatoprotective effects of purple potato anthocyanins (PPAs) were investigated in the ALD mouse model. Serum and liver biochemical parameters were determined, along with histopathological changes in liver tissue. In addition, the major contributors to alcohol-induced oxidative stress were assessed. The results indicated that the levels of aspartate transaminase and alanine transaminase were lower in the serum of the PPA-treated group than the alcohol-treated group. PPAs significantly inhibited the reduction of total cholesterol and triglycerides. Higher levels of superoxide dismutase and reduced glutathione enzymes as well as a reduction in the formation of malondialdehyde occurred in mice fed with PPAs. In addition, PPAs protected against increased alcohol-induced levels and activity of cytochrome P450 2E1 (CYP2E1), which demonstrates the effects of PPAs against alcohol-induced oxidative stress and liver injury. This study suggests that PPAs could be an effective therapeutic agent in alcohol-induced liver injuries by inhibiting CYP2E1 expression and thereby strengthening antioxidant defenses. PMID:26481011

  5. Rhodoferax antarcticus sp. nov., a moderately psychrophilic purple nonsulfur bacterium isolated from an Antarctic microbial mat

    NASA Technical Reports Server (NTRS)

    Madigan, M. T.; Jung, D. O.; Woese, C. R.; Achenbach, L. A.

    2000-01-01

    A new species of purple nonsulfur bacteria isolated from an Antarctic microbial mat is described. The organism, designated strain ANT.BR, was mildly psychrophilic, growing optimally at 15-18 degrees C with a growth temperature range of 0-25 degrees C. Cells of strain ANT.BR were highly motile curved rods and spirals, contained bacteriochlorophyll a, and showed a multicomponent in vivo absorption spectrum. A specific phylogenetic relationship was observed between strain ANT.BR and the purple bacterium Rhodoferax fermentans FR2T, and the two organisms shared several physiological and other phenotypic properties, with the notable exception of growth temperature optimum. Tests of genomic DNA hybridization, however, showed Rfx. fermentans FR2T and strain ANT.BR to be genetically distinct bacteria. Because of its unique set of properties, especially its requirement for low growth temperatures, we propose to recognize strain ANT.BR as a new species of the genus Rhodoferax, Rhodoferax antarcticus, named for its known habitat, the Antarctic.

  6. Carotenoid profile and retention in yellow-, purple- and red-fleshed potatoes after thermal processing.

    PubMed

    Kotíková, Zora; Šulc, Miloslav; Lachman, Jaromír; Pivec, Vladimír; Orsák, Matyáš; Hamouz, Karel

    2016-04-15

    This research aimed to investigate the effect of thermal processing on carotenoid profile, quantity and stability in 22 colour-fleshed potato cultivars grown in the Czech Republic. The total of nine carotenoids was analysed by HPLC using a C30 column and PDA detection. The total carotenoid content for all cultivars ranged from 1.44 to 40.13 μg/g DM. Yellow cultivars showed a much higher average total carotenoid content (26.22 μg/g DM) when compared to red/purple-fleshed potatoes (5.69 μg/g DM). Yellow cultivars were dominated by antheraxanthin, whereas neoxanthin was the main carotenoid in red/purple cultivars. Thermal processing significantly impacted all potato cultivars. Boiling decreased the total carotenoids by 92% compared to baking (88%). Lutein was the most stable carotenoid against thermal processing (decreased by 24-43%) followed by β-carotene (decreased by 78-83%); other carotenoids were degraded nearly completely. Increased formation of (Z)-isomers by thermal processing has not been confirmed. PMID:26617045

  7. Purple sweet potato color inhibits endothelial premature senescence by blocking the NLRP3 inflammasome.

    PubMed

    Sun, Chunhui; Fan, Shaohua; Wang, Xin; Lu, Jun; Zhang, Zifeng; Wu, Dongmei; Shan, Qun; Zheng, Yuanlin

    2015-10-01

    Purple sweet potato color (PSPC), flavonoids isolated from purple sweet potato, has been well demonstrated for the pharmacological properties. In the present study, we attempt to explore whether the antisenescence was involved in PSPC-mediated protection against endothelium dysfunction in type 2 diabetes mellitus (T2DM) and, if involved, what are the possible mechanisms. The results showed that atherogenesis and endothelial senescence in the thoracic aorta were promoted in mice with prediabetes; meanwhile, PSPC attenuated the deterioration of vascular vessel and inhibited the endothelial senescence. Diabetes mellitus is a documented high-risk factor for the development of atherosclerosis. Studies show that D-galactose (D-gal) promotes endothelial cell senescence in vitro. In our study, we have determined that PSPC could suppress the D-gal-induced premature senescence and the abnormal endothelial function, discovered in the early stages of atherosclerosis induced by T2DM. We have discovered that the PSPC down-regulates reactive oxygen species (ROS) accumulation and the NLRP3 inflammasome functions. Furthermore, the premature senescence induced by D-gal was inhibited after attenuation of ROS and deactivation of NLRP3 inflammasomes. However, once the NLRP3 inflammasomes are overactivated, PSPC could not restrain cell senescence. These data imply that the beneficial effects of PSPC on diabetes-induced endothelial dysfunction and senescence are mediated through ROS and NLRP3 signaling pathways, suggesting a potential target for the prevention of endothelial senescence-related cardiovascular diseases. PMID:26164602

  8. Characterization, antioxidant and antitumor activities of polysaccharides from purple sweet potato.

    PubMed

    Wu, Qiongying; Qu, Hongsen; Jia, Junqiang; Kuang, Cong; Wen, Yan; Yan, Hui; Gui, Zhongzheng

    2015-11-01

    Three polysaccharides, PSPP1-1, PSPP2-1 and PSPP3-1, were isolated from purple sweet potato. The three polysaccharides belonged to β-type polysaccharides and contained low proportions of proteins and uronic acids. PSPP1-1 and PSPP3-1 with molecular weights of 33.3 and 75.3 kDa, respectively, were composed of rhamnose, xylose, glucose and galactose, whereas PSPP2-1 with molecular weight of 17.8 kDa was composed of rhamnose and galactose. The three polysaccharides possessed in vitro antioxidant (scavenging DPPH radicals, chelating ferrous ions and reducing power) and antitumor activities (against SGC7901 and SW620 cells) in a dose-dependent manner. Among the three polysaccharides, PSPP2-1 exhibited the strongest reducing power, scavenging activity on DPPH radicals and chelating capability on ferrous ions. PSPP1-1 showed the strongest inhibitory activities on the growth of SGC7901 and SW620 cells. In addition, flow cytometry results showed that PSPP1-1 could induce apoptosis in SGC7901 and SW620 cells. These results suggest that polysaccharides from purple sweet potato are potential natural antioxidant and antitumor agents that can be used as drugs or functional food ingredients. PMID:26256321

  9. Methylation mediated by an anthocyanin, O-methyltransferase, is involved in purple flower coloration in Paeonia

    PubMed Central

    Du, Hui; Wu, Jie; Ji, Kui-Xian; Zeng, Qing-Yin; Bhuiya, Mohammad-Wadud; Su, Shang; Shu, Qing-Yan; Ren, Hong-Xu; Liu, Zheng-An; Wang, Liang-Sheng

    2015-01-01

    Anthocyanins are major pigments in plants. Methylation plays a role in the diversity and stability of anthocyanins. However, the contribution of anthocyanin methylation to flower coloration is still unclear. We identified two homologous anthocyanin O-methyltransferase (AOMT) genes from purple-flowered (PsAOMT) and red-flowered (PtAOMT) Paeonia plants, and we performed functional analyses of the two genes in vitro and in vivo. The critical amino acids for AOMT catalytic activity were studied by site-directed mutagenesis. We showed that the recombinant proteins, PsAOMT and PtAOMT, had identical substrate preferences towards anthocyanins. The methylation activity of PsAOMT was 60 times higher than that of PtAOMT in vitro. Interestingly, this vast difference in catalytic activity appeared to result from a single amino acid residue substitution at position 87 (arginine to leucine). There were significant differences between the 35S::PsAOMT transgenic tobacco and control flowers in relation to their chromatic parameters, which further confirmed the function of PsAOMT in vivo. The expression levels of the two homologous AOMT genes were consistent with anthocyanin accumulation in petals. We conclude that AOMTs are responsible for the methylation of cyanidin glycosides in Paeonia plants and play an important role in purple coloration in Paeonia spp. PMID:26208646

  10. Diversity of purple nonsulfur bacteria in shrimp ponds with varying mercury levels.

    PubMed

    Mukkata, Kanokwan; Kantachote, Duangporn; Wittayaweerasak, Banjong; Techkarnjanaruk, Somkiet; Boonapatcharoen, Nimaradee

    2016-07-01

    This research aimed to study the diversity of purple nonsulfur bacteria (PNSB) and to investigate the effect of Hg concentrations in shrimp ponds on PNSB diversity. Amplification of the pufM gene was detected in 13 and 10 samples of water and sediment collected from 16 shrimp ponds in Southern Thailand. In addition to PNSB, other anoxygenic phototrophic bacteria (APB) were also observed; purple sulfur bacteria (PSB) and aerobic anoxygenic phototrophic bacteria (AAPB) although most of them could not be identified. Among identified groups; AAPB, PSB and PNSB in the samples of water and sediment were 25.71, 11.43 and 8.57%; and 27.78, 11.11 and 22.22%, respectively. In both sample types, Roseobacter denitrificans (AAPB) was the most dominant species followed by Halorhodospira halophila (PSB). In addition two genera, observed most frequently in the sediment samples were a group of PNSB (Rhodovulum kholense, Rhodospirillum centenum and Rhodobium marinum). The UPGMA dendrograms showed 7 and 6 clustered groups in the water and sediment samples, respectively. There was no relationship between the clustered groups and the total Hg (HgT) concentrations in the water and sediment samples used (<0.002-0.03 μg/L and 35.40-391.60 μg/kg dry weight) for studying the biodiversity. It can be concluded that there was no effect of the various Hg levels on the diversity of detected APB species; particularly the PNSB in the shrimp ponds. PMID:27298580

  11. Effect of the applied drying method on the physical properties of purple carrot pomace

    NASA Astrophysics Data System (ADS)

    Janiszewska, E.; Witrowa-Rajchert, D.; Kidoń, M.; Czapski, J.

    2013-03-01

    The aim of the study was to determine the effect of different drying methods on selected physical properties of pomace obtained from purple carrot cv. Deep Purple. Drying was performed using four methods: convective, microwave-convective, infrared-convective and freeze-drying. The freeze-dried material had the lowest apparent density (422 kg m-3), which was caused by slight shrinkage, and indicated high porosity. Apparent density was almost three times greater in dried materials produced using the other drying methods as compared to the freeze-dried variants. Freeze-dried pomace adsorbed vapour more quickly than the other dried variants, which was caused by its high porosity and relatively low degree of structural damage. Rehydration characteristicswere significantly affected by the dryingmethod. The highest mass increase and losses of soluble substance were recorded for the freeze-dried samples. Conversely, the traditional convective drying method resulted in the lowest mass increase and soluble substance leaching. A positive linear correlation was found between the loss of soluble dry substance components and the absorbance of liquid obtained during rehydration.

  12. Characterization of Secondary Metabolites from Purple Ipomoea batatas Leaves and Their Effects on Glucose Uptake.

    PubMed

    Lee, Chia-Lin; Lee, Shou-Lun; Chen, Chao-Jung; Chen, Hsin-Chun; Kao, Ming-Ching; Liu, Chuan-Hao; Chen, Jau-Yang; Lai, Yen-Ting; Wu, Yang-Chang

    2016-01-01

    Ipomoea batatas has long been used in folk medicine for the treatment of hyperglycemia or as a food additive for the prevention of type 2 diabetes. However, neither the plant extract nor its active components have been evaluated systematically. In this work four crude extracts, including n-hexane- (IBH), 95% MeOH- (IBM), n-BuOH- (IBB), and H₂O-soluble (IBW) fractions, were prepared by fractionation of a methanolic extract of purple I. batatas leaves. Twenty-four pure compounds 1-24 were then isolated by various chromatographic techniques and their structures identified from NMR and MS data. Glucose uptake assays in differentiated 3T3-L1 adipocytes and rat primary hepatocytes, as well as western blot analysis, were carried out to evaluate the antidiabetic activity of this species. The IBH crude fraction, with methyl decanoate (22) as a major and active compound, showed the greatest effect on glucose uptake, most likely via activation of Glut4 and regulation of the PI3K/AKT pathway. Quercetin 3-O-β-d-sophoroside (1), quercetin (3), benzyl β-d-glucoside (10), 4-hydroxy-3-methoxybenzaldehyde (12), and methyl decanoate (22) could be important components contributing to the antidiabetic effects. We conclude that purple I. batatas leaves have potential as an antidiabetic plant source and the active constituents 1, 3, 10, 12, and 22 are promising lead candidates for future investigation. PMID:27338312

  13. Tailored fragments of roseophilin selectively antagonize Mcl-1 in vitro

    PubMed Central

    Bracken, Jack D.; Carlson, Andrew D.; Frederich, James H.; Nguyen, Mai; Shore, Gordon C.; Harran, Patrick G.

    2015-01-01

    We have discovered a fragment of the natural product roseophilin, a member of the prodiginine family, that antagonizes Mcl-1 functions in a liposome-based assay for mitochondrial membrane permeabilization. By tailoring this substance such that it can participate in salt bridging with the protein surface, we have prepared the first prodiginine inspired structure that shows direct, saturable binding to a recombinant Bcl-2 family member in vitro. PMID:26019371

  14. Fragmentation Function in Thermofield Dynamics

    NASA Astrophysics Data System (ADS)

    Ladrem, M.; Chekerker, M.; Khanna, F. C.; Santana, A. E.

    2013-04-01

    The fragmentation function at high energy experiments is introduced by using thermofield dynamics (TFD), a real-time finite-temperature quantum field formalism. Due to the structure of TFD, the results at T = 0 and T ≠ 0 are split in a direct way. As an application, we consider the temperature effect on the fragmentation function of a hadron leading to quark-antiquark pairs. Using a definition of Wilson-loop in real-time, we find that the fragmentation function decreases in magnitude with an increase in the temperature.

  15. Velocity fluctuations of fission fragments

    NASA Astrophysics Data System (ADS)

    Llanes-Estrada, Felipe J.; Carmona, Belén Martínez; Martínez, Jose L. Muñoz

    2016-02-01

    We propose event by event velocity fluctuations of nuclear fission fragments as an additional interesting observable that gives access to the nuclear temperature in an independent way from spectral measurements and relates the diffusion and friction coefficients for the relative fragment coordinate in Kramers-like models (in which some aspects of fission can be understood as the diffusion of a collective variable through a potential barrier). We point out that neutron emission by the heavy fragments can be treated in effective theory if corrections to the velocity distribution are needed.

  16. Fragmentation of drying paint layers

    NASA Astrophysics Data System (ADS)

    Bakos, Katinka; Dombi, András; Járai-Szabó, Ferenc; Néda, Zoltán

    2013-11-01

    Fragmentation of thin layers of drying granular materials on a frictional surface are studied both by experiments and computer simulations. Besides a qualitative description of the fragmentation phenomenon, the dependence of the average fragment size as a function of the layer thickness is thoroughly investigated. Experiments are done using a special nail polish, which forms characteristic crack structures during drying. In order to control the layer thickness, we diluted the nail polish in acetone and evaporated in a controlled manner different volumes of this solution on glass surfaces. During the evaporation process we managed to get an instable paint layer, which formed cracks as it dried out. In order to understand the obtained structures a previously developed spring-block model was implemented in a three-dimensional version. The experimental and simulation results proved to be in excellent qualitative and quantitative agreement. An earlier suggested scaling relation between the average fragment size and the layer thickness is reconfirmed.

  17. (Natural fragmentation of exploding cylinders)

    SciTech Connect

    Grady, D.E.; Hightower, M.M.

    1990-01-01

    The natural fragmentation of a 4140 steel cylinder fully loaded with RX-35-AN insensitive high explosive is investigated through experiment and analysis. Methods of Taylor and Gurney are used to determine the fracture strain and kinematic state of the expanding cylinder. Energy methods based on mechanisms of both tension fracture and adiabatic shear fracture are used to calculate the circumferential fragmentation intensity. 9 refs., 5 figs.

  18. Characterization of anthocyanins and anthocyanidins in purple-fleshed sweetpotatoes by HPLC-DAD and LC-ESI/MS-MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple-fleshed sweetpotatoes (PFSP) can be a healthy food choice for consumers and a potential source for natural food colorants. This study aimed to identify anthocyanins and anthocyanidins in PFSP, and to evaluate the effect of thermal processing on these polyphenolic compounds. Freeze-dried powde...

  19. Effect of steam-cooking and parboiling on phenolics and antioxidant capacities of red and purple rice cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red and purple rice cultivars contain high concentrations of phenolics, such as proanthocyanidins and anthocyanins, respectively. We investigated the effect of cooking processes on these antioxidants and antioxidant capacities of pigmented and common light-brown bran rice. The cooking processes incl...

  20. An emerging potato purple top disease caused by a new 16SrIII group phytoplasma in Montana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato purple top (PPT) is a devastating disease that occurs in the United States, Canada, Mexico, Russia, and elsewhere. There are at least seven distinct phytoplasma strains belonging to five different phytoplasma groups (16SrI, 16SrII, 16SrVI, 16SrXII, and 16SrXVIII) that were reported to cause p...

  1. Characterization of the regulatory network of BoMYB2 in controlling anthocyanin biosynthesis in purple cauliflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple cauliflower (Brassica oleracea L. var. botrytis) Graffiti represents a unique mutant in conferring ectopic anthocyanin biosynthesis, which is caused by the tissue specific activation of BoMYB2, an ortholog of Arabidopsis PAP2 or MYB113. To gain a better understanding of the regulatory network...

  2. Evaluation of hay, green, and plastic mulches for the suppression of purple and yellow nutsedges in tomato production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple and yellow nutsedges (Cyperus rotundus and C. esculentus) are the most troublesome weeds in the cropping systems in Florida and the Caribbean where they have been reported to cause yield losses of 20-89% in different horticultural crops. Production systems based on plastic mulching and methyl...

  3. Extraction of anthocyanins from industrial purple-fleshed sweetpotatoes and enzymatic hydrolysis of residues for fermentable sugars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent trends in health and wellness as well as fossil fuel dependent markets provide opportunities for agricultural crops as renewable resources in partial replacement of synthetic components in food, clothing and fuels. This investigation focused on purple-fleshed industrial sweetpotatoes (ISPs), ...

  4. Quality of fresh-cut purple fleshed sweet potatoes after x-ray irradiation treatment and refrigerated storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of x-ray irradiation on the quality of fresh-cut, refrigerated purple-fleshed sweetpotato (PFSP) cubes was investigated. Packaged sweetpotato cubes were treated with 0, 250, 500, 750 or 1000 Gy x-ray irradiation and stored at 4 ± 1 ºC for 14 days. After 14 days, total aerobic bacteria cou...

  5. Mass production and application of Dactylaria higginsii, a bioherbicide for purple and yellow nutsedges, in solid substrate of plant material

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purple and yellow nutsedges (Cyperus rotundus & C. esculentus) are serious weeds in the cropping systems in Florida and in many parts of the world. They have been reported to cause yield losses of 20-89% in various crops. When methyl bromide is phased out, the losses due to nutsedge competition are ...

  6. Certification of Completion of Level-2 Milestone 461: Deploy First Phase of I/O Infrastructure for Purple

    SciTech Connect

    Gary, M; Wiltzius, D

    2005-11-17

    This report describes the deployment and demonstration of the first phase of the I/O infrastructure for Purple. The report and the references herein are intended to certify the completion of the following Level 2 Milestone from the ASC FY04-05 Implementation Plan, due at the end of Quarter 4 in FY05. The milestone is defined as follows: ''External networking infrastructure installation and performance analysis will be completed for the initial delivery of Purple. The external networking infrastructure includes incorporation of a new 10 Gigabit Ethernet fabric linking the platform to the LLNL High Performance Storage System (HPSS) and other center equipment. The LLNL archive will be upgraded to HPSS Release 5.1 to support the requirements of the machine and performance analysis will be completed using the newly deployed I/O infrastructure. Demonstrated throughput to the archive for this infrastructure will be a minimum of 1.5GB/s with a target of 3GB/s. Since Purple delivery is not scheduled until late Q3, demonstration of these performance goals will use parts of Purple and/or an aggregate of other existing resources.''

  7. Preparative isolation of anthocyanins from Japanese purple sweet potato (Ipomoea batatas L.) varieties by high-speed countercurrent chromatography.

    PubMed

    Montilla, Elyana Cuevas; Hillebrand, Silke; Butschbach, Daniela; Baldermann, Susanne; Watanabe, Naoharu; Winterhalter, Peter

    2010-09-22

    Purple-fleshed sweet potatoes (Ipomoea batatas L.) contain a very complex anthocyanin profile due to the presence of several non-, mono-, and diacylated glucosides of cyanidin and peonidin. In this study, the anthocyanin composition of four Japanese purple sweet potato cultivars (Chiran Murasaki, Tanegashima Murasaki, Naka Murasaki, and Purple Sweet) were investigated by HPLC-DAD and ESI-MSn analyses. The HPLC chromatograms of the different cultivars show a remarkable variation of the two major pigments, cyanidin-3-(6''-caffeoylsophoroside)-5-glucoside and peonidin-3-(6''-caffeoylsophoroside)-5-glucoside, respectively. According to this, they can be categorized into two groups on the basis of the peonidin/cyanidin ratio: the cultivars Chiran Murasaki and Purple Sweet showed a high content of peonidin derivatives (peonidin type), whereas the varieties Tanegashima Murasaki and Naka Murasaki were classified as cyanidin types. By means of high-speed countercurrent chromatography (HSCCC) the nonacylated 3-sophoroside-5-glucoside of cyanidin was isolated on a preparative scale. Furthermore, it was possible to isolate the monoacylated cyanidin-3-(6''-caffeoylsophoroside)-5-glucoside as well as three diacylated major pigments, cyanidin-3-(6'',6'''-dicaffeoylsophoroside)-5-glucoside, cyanidin-3-(6''-caffeoyl-6'''-p-hydroxy-benzoylsophoroside)-5-glucoside, and peonidin-3-(6''-caffeoyl-6'''-p-hydroxybenzoyl-sophoroside)-5-glucoside. The purity and identity of the so-obtained pigments were confirmed by NMR measurements. PMID:20731350

  8. Fragmentation of hot classical drops

    SciTech Connect

    Vicentini, A.; Jacucci, G.; Pandharipande, V.R.

    1985-05-01

    Time evolution of hot drops of matter containing approx.230 or approx.130 particles is studied by classical molecular dynamics. Initially, the drops have uniform density and a sharp surface. The chosen initial conditions include three values of density and a range of temperatures wide enough to study the phenomena of evaporation, fragmentation, and total vaporization in a unified fashion. The average density and temperature of central matter is measured periodically to obtain trajectories of the evolution in the rho,T plane. These trajectories indicate that the matter expands almost adiabatically until it reaches the region of adiabatic instabilities. Density inhomogeneities develop in this region, but the matter fragments only if the expansion continues to average densities of less than one-fourth the liquid density, otherwise it recondenses into a single blob. The recondensed matter and fragments have very crooked surfaces. If the temperature is high enough, the expanding matter does not enter the region of adiabatic instabilities and totally vaporizes. For initial densities of the order of equilibrium density, matter does not fragment or develop large inhomogeneities in the region enclosed by the isothermal and adiabatic spinodals. Thus it appears unlikely that fragmentation of small drops (nuclei) can be used to study the isothermal critical region of gas-liquid phase transition. A detailed tabulation of the energies and number of monomers, dimers, light, and heavy fragments emitted in each event is presented.

  9. Photocurrents Generated by Bacteriorhodopsin Adsorbed on Nano-Black Lipid Membranes

    PubMed Central

    Horn, Christian; Steinem, Claudia

    2005-01-01

    Purple membranes were adsorbed on freestanding lipid bilayers, termed nano-black lipid membranes (nano-BLMs), suspending the pores of porous alumina substrates with average pore diameters of 280 nm. Nano-BLMs were obtained by first coating the upper surface of the highly ordered porous alumina substrates with a thin gold layer followed by chemisorption of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol and subsequent addition of a droplet of 1,2-diphytanoyl-sn-glycero-3-phosphocholine and octadecylamine dissolved in n-decane onto the hydrophobic submonolayer. By means of impedance spectroscopy, the quality of the nano-BLMs was verified. The electrical parameters confirm the formation of single lipid bilayers with high membrane resistances covering the porous matrix. Adsorption of purple membranes on the nano-BLMs was followed by recording the photocurrents generated by bacteriorhodopsin upon continuous light illumination. The membrane system exhibits a very high long-term stability with the advantage that not only transient but also stationary currents are recordable. By adding the proton ionophore carbonyl cyanide-m-chlorophenylhydrazone the conductivity of the nano-BLMs increases, resulting in a higher stationary current, which proves that proton conductance occurs across the nano-BLMs. PMID:15908580

  10. Nanomechanical properties of proteins and membranes depend on loading rate and electrostatic interactions.

    PubMed

    Medalsy, Izhar D; Müller, Daniel J

    2013-03-26

    Knowing the dynamic mechanical response of tissue, cells, membranes, proteins, nucleic acids, and carbohydrates to external perturbations is important to understand various biological and biotechnological problems. Atomic force microscopy (AFM)-based approaches are the most frequently used nanotechnologies to determine the mechanical properties of biological samples that range in size from microscopic to (sub)nanoscopic. However, the dynamic nature of biomechanical properties has barely been addressed by AFM imaging. In this work, we characterizethe viscoelastic properties of the native light-driven proton pump bacteriorhodopsin of the purple membrane of Halobacterium salinarum. Using force-distance curve (F-D)-based AFM we imaged purple membranes while force probing their mechanical response over a wide range of loading rates (from ∼0.5 to 100 μN/s). Our results show that the mechanical stiffness of protein and membrane increases with the loading rate up to a factor of 10 (from ∼0.3 to 3.2 N/m). In addition, the electrostatic repulsion between AFM tip and sample can alter the mechanical stiffness measured by AFM up to ∼60% (from ∼0.8 to 1.3 N/m).These findings indicate that the mechanical response of membranes and proteins and probably of other biomolecular systems should be determined at different loading rates to fully understand their properties. PMID:23442147

  11. Top-Down Mass Spectrometry Analysis of Membrane-Bound Light-Harvesting Complex 2 from Rhodobacter sphaeroides.

    PubMed

    Lu, Yue; Zhang, Hao; Cui, Weidong; Saer, Rafael; Liu, Haijun; Gross, Michael L; Blankenship, Robert E

    2015-12-15

    We report a top-down proteomic analysis of the membrane-bound peripheral light-harvesting complex LH2 isolated from the purple photosynthetic bacterium Rhodobacter sphaeroides. The LH2 complex is coded for by the puc operon. The Rb. sphaeroides genome contains two puc operons, designated puc1BAC and puc2BA. Although previous work has shown consistently that the LH2 β polypeptide coded by the puc2B gene was assembled into LH2 complexes, there are contradictory reports as to whether the Puc2A polypeptides are incorporated into LH2 complexes. Furthermore, post-translational modifications of this protein offer the prospect that it could coordinate bacteriochlorophyll a (Bchl a) by a modified N-terminal residue. Here, we describe the components of the LH2 complex on the basis of electron-capture dissociation fragmentation to confirm the identity and sequence of the protein's subunits. We found that both gene products of the β polypeptides are expressed and assembled in the mature LH2 complex, but only the Puc1A-encoded polypeptide α is observed here. The methionine of the Puc2B-encoded polypeptide is missing, and a carboxyl group is attached to the threonine at the N-terminus. Surprisingly, one amino acid encoded as an isoleucine in both the puc2B gene and the mRNA is found as valine in the mature LH2 complex, suggesting an unexpected and unusual post-translational modification or a specific tRNA recoding of this one amino acid. PMID:26574182

  12. Fragmentation Pathways in the Uracil Radical Cation

    SciTech Connect

    Zhou, Congyi; Matsika, Spiridoula; Kotur, Marija; Weinacht, Thomas C.

    2012-08-24

    We investigate pathways for fragmentation in the uracil radical cation using ab initio electronic structure calculations. We focus on the main fragments produced in pump–probe dissociative ionization experiments. These are fragments with mass to charge ratios (m/z) of 69, 28, 41, and 42. Barriers to dissociation along the ground ionic surface are reported, which provide an estimate of the energetic requirements for the production of the main fragments. Finally, direct and sequential fragmentation mechanisms have been analyzed, and it is concluded that sequential fragmentation after production of fragment with m/z 69 is the dominant mechanism for the production of the smaller fragments.

  13. Conspecific brood parasitism in the tropics: an experimental investigation of host responses in common moorhens and American purple gallinules.

    PubMed

    McRae, Susan B

    2011-11-01

    Species occupying a broad latitudinal range may show greater phenotypic plasticity in behavior than species with smaller ranges or more specific habitat requirements. This study investigates for the first time the occurrence of conspecific brood parasitism (CBP) in sympatric tropical populations of the common moorhen (Gallinula chloropus pauxilla Bangs) and the American purple gallinule (Porphyrula martinica L.). CBP occurred in at least 20% (N = 76) of common moorhen nests on the Rio Chagres in Panama. Half (N = 20) of the parasitic eggs were accepted, but 10 were destroyed or ejected from host nests. Introductions of experimental eggs into nests revealed hosts were more likely to accept parasitism later in the host's laying period and during incubation, consistent with expectation of an adaptive response. CBP was not detected in a small sympatric population of American purple gallinules. Members of this population did not eject experimental eggs, suggesting a lack of experience with costly CBP. Contrasting ecological factors help explain why these two species of rail (Family Rallidae) differ in regard to CBP. Purple gallinule territories were sparse, owing to the distribution of preferred habitat. Moorhens flocked outside of the breeding season. They nested more synchronously, at higher densities, and primarily in ephemeral floating vegetation. Further, moorhens suffered a rate of nest loss nearly double that of American purple gallinules, and this increased over the course of the breeding season. Moorhen clutches were larger on average, and more variable in size than those of purple gallinules. Reproductive effort and rate (seasonality) constitute important life history differences between these species that may constrain the evolution of reproductive tactics. Comparing these sympatric populations, and others differing in life-history traits and ecological constraints, highlights the role of risk management in the evolution of CBP. PMID:22393503

  14. Functional assembly of protein fragments induced by spatial confinement.

    PubMed

    Yu, Yongsheng; Wang, Jianpeng; Liu, Jiahui; Ling, Daishun; Xia, Jiang

    2015-01-01

    Natural proteins are often confined within their local microenvironments, such as three-dimensional confinement in organelles or two-dimensional confinement in lipid rafts on cytoplasmic membrane. Spatial confinement restricts proteins' entropic freedom, forces their lateral interaction, and induces new properties that the same proteins lack at the soluble state. So far, the phenomenon of environment-induced protein functional alteration still lacks a full illustration. We demonstrate here that engineered protein fragments, although being non-functional in solution, can be re-assembled within the nanometer space to give the full activity of the whole protein. Specific interaction between hexahistidine-tag (His-tag) and NiO surface immobilizes protein fragments on NiO nanoparticles to form a self-assembled protein "corona" on the particles inside the nanopores of mesoporous silica. Site-specific assembly forces a shoulder-by-shoulder orientation and promotes fragment-fragment interaction; this interaction together with spatial confinement of the mesopores results in functional re-assembly of the protein half fragments. To our surprise, a single half fragment of luciferase (non-catalytic in solution) exhibited luciferase activity when immobilized on NiO in the mesopores, in the absence of the complimentary half. This shows for the first time that spatial confinement can induce the folding of a half fragment, reconstitute the enzyme active site, and re-gain the catalytic capability of the whole protein. Our work thereby highlights the under-documented notion that aside from the chemical composition such as primary sequence, physical environment of a protein also determines its function. PMID:25875003

  15. Crystalline Membranes

    NASA Technical Reports Server (NTRS)

    Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)

    2008-01-01

    In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

  16. Photoprotection Mechanism of Light-Harvesting Antenna Complex from Purple Bacteria.

    PubMed

    Kosumi, Daisuke; Horibe, Tomoko; Sugisaki, Mitsuru; Cogdell, Richard J; Hashimoto, Hideki

    2016-02-11

    Photosynthetic light-harvesting apparatus efficiently capture sunlight and transfer the energy to reaction centers, while they safely dissipate excess energy to surrounding environments for a protection of their organisms. In this study, we performed pump-probe spectroscopic measurements with a temporal window ranging from femtosecond to submillisecond on the purple bacterial antenna complex LH2 from Rhodobacter sphaeroides 2.4.1 to clarify its photoprotection functions. The observed excited state dynamics in the time range from subnanosecond to microsecond exhibits that the triplet-triplet excitation energy transfer from bacteriochlorophyll a to carotenoid takes place with a time constant of 16.7 ns. Furthermore, ultrafast spectroscopic data suggests that a molecular assembly of bacteriochlorophyll a in LH2 efficiently suppresses a generation of triple bacteriochlorophyll a. PMID:26800035

  17. A Case of Purple Urine Bag Syndrome in a Spastic Partial Quadriplegic Male

    PubMed Central

    Khan, Salman; Dave, Atman; Morrison, Amelia Jane A; Jain, Swapna; Hermanns, David

    2016-01-01

    Purple bag urine syndrome (PUBS) is a benign and unique phenomenon of the urine turning a deep violet color within the urinary catheter tubing and bag. This phenomenon is commonly encountered in patients indicated with long-term catheter placement or, in certain conditions like chronic constipation, alkaline urine, limited ambulation, and, in terms of gender distribution, the female sex, predominates. PUBS gets its name from a unique phenomenon that takes places inside the gut where tryptophan (an amino acid) is metabolized, producing blue and red hues which together emanate a deep violet color. Here, the case of a middle-aged male patient with a suprapubic catheter in situ, following trauma causing spastic partial quadriplegia, is being presented with PUBS due to UTI secondary to Proteus vulgaris. The risk factors, in this case, include chronic constipation and recurrent urinary tract infections (UTIs).​ PMID:27182466

  18. Decoherence dynamics of coherent electronic excited states in the photosynthetic purple bacterium Rhodobacter sphaeroides

    NASA Astrophysics Data System (ADS)

    Liang, Xian-Ting; Zhang, Wei-Min; Zhuo, Yi-Zhong

    2010-01-01

    In this paper, we present a theoretical description to the quantum coherence and decoherence phenomena of energy transfer in photosynthesis observed in a recent experiment [Science 316, 1462 (2007)]. As a successive two-color laser pulses with selected frequencies cast on a sample of the photosynthetic purple bacterium Rb. sphaeroides two resonant excitations of electrons in chromophores can be generated. However, this effective two-level subsystem will interact with its protein environment and decoherence is inevitable. We describe this subsystem coupled with its environment as a dynamical spin-boson model. The non-Markovian decoherence dynamics is described using a quasiadiabatic propagator path integral (QUAPI) approach. With the photon-induced effective time-dependent level splitting energy and level flip coupling coefficient between the two excited states and the environment-induced non-Markovian decoherence dynamics, our theoretical result is in good agreement with the experimental data.

  19. Calibration of the Purple Crow Lidar vibrational Raman water-vapour mixing ratio and temperature measurements

    NASA Astrophysics Data System (ADS)

    Argall, P. S.; Sica, R. J.; Bryant, C. R.; Algara-Siller, M.; Schijns, H.

    2007-02-01

    Purple Crow Lidar (PCL) measurements of the vibrational Raman-shifted backscatter from water vapour and nitrogen molecules allows height profiles of the water-vapour mixing ratio to be measured from 500 m up into the lower stratosphere. In addition, the Raman nitrogen measurements allow the determination of temperature profiles from about 10 to 40 km altitude. However, external calibration of these measurements is necessary to compensate for instrumental effects, uncertainties in our knowledge of the relevant molecular cross sections, and atmospheric transmission. A comparison of the PCL-derived water-vapour concentration and temperature profiles with routine radiosonde measurements from Detroit and Buffalo on 37 and 141 nights, respectively, was undertaken to provide this calibration. The calibration is then applied to the measurements and monthly mean-temperature and water-vapour profiles are determined.

  20. Accumulation and depuration of paralytic shellfish poisoning toxins by laboratory cultured purple clam Hiatula diphos Linnaeus.

    PubMed

    Chou, Hong Nong; Huang, Chen Ping; Chen, Chih Yu

    2005-10-01

    Purple clams (Hiatula diphos Linnaeus) accumulate paralytic shellfish poisoning (PSP) toxins produced by a toxic strain of the dinoflagellate Alexandrium minutum Halim in a laboratory study. The maximal toxicity of PSP toxins attained 31.3m MU/g after 20 days exposure. The toxin profile of H. diphos was similar to that reported for A. minutum at the end of the exposure period; and GTX1 was dominant. GTX congeners were found in muscle on day 16 and day 20, these substances could be detected during the depuration period as well. GTX1 was detected in the siphon only on day 32. The results show that H. diphos accumulates PSP toxins according to the amount and toxin profile of ingested A. minutum. PMID:16137734

  1. Conventional, ultrasound-assisted, and accelerated-solvent extractions of anthocyanins from purple sweet potatoes.

    PubMed

    Cai, Zhan; Qu, Ziqian; Lan, Yu; Zhao, Shujuan; Ma, Xiaohua; Wan, Qiang; Jing, Pu; Li, Pingfan

    2016-04-15

    Purple sweet potatoes (PSPs) are rich in anthocyanins. In this study, we investigated the extraction efficiency of anthocyanins from PSPs using conventional extraction (CE), ultrasound-assisted extraction (UAE), and accelerated-solvent extraction (ASE). Additionally, the effects of these extraction methods on antioxidant activity and anthocyanin composition of PSP extracts were evaluated. In order of decreasing extraction efficiency, the extraction methods were ASE>UAE>CE for anthocyanins (218-244 mg/100 g DW) and CE>UAE>ASE for total phenolics (631-955 mg/100 g DW) and flavonoids (28-40 mg/100 g DW). Antioxidant activities of PSP extracts were CE≈UAE>ASE for ORAC (766-1091 mg TE/100 g DW) and ASE>CE≈UAE for FRAP (1299-1705 mg TE/100 g DW). Twelve anthocyanins were identified. ASE extracts contained more diacyl anthocyanins and less nonacyl and monoacyl anthocyanins than CE and ASE extracts (P<0.05). PMID:26616949

  2. Depleted Uranium Toxicity, Accumulation, and Uptake in Cynodon dactylon (Bermuda) and Aristida purpurea (Purple Threeawn).

    PubMed

    Butler, Afrachanna D; Wynter, Michelle; Medina, Victor F; Bednar, Anthony J

    2016-06-01

    Yuma Proving Grounds (YPG) in western Arizona is a testing range where Depleted uranium (DU) penetrators have been historically fired. A portion of the fired DU penetrators are being managed under controlled conditions by leaving them in place. The widespread use of DU in armor-penetrating weapons has raised environmental and human health concerns. The present study is focused on the onsite management approach and on the potential interactions with plants local to YPG. A 30 day study was conducted to assess the toxicity of DU corrosion products (e.g., schoepite and meta-schoepite) in two grass species that are native to YPG, Bermuda (Cynodon dactylon) and Purple Threeawn (Aristida purpurea). In addition, the ability for plants to uptake DU was studied. The results of this study show a much lower threshold for biomass toxicity and higher plant concentrations, particularly in the roots than shoots, compared to previous studies. PMID:27016940

  3. Peltomexicanin, a Peltogynoid Quinone Methide from Peltogyne Mexicana Martínez Purple Heartwood.

    PubMed

    Gutiérrez-Macías, Paulina; Peralta-Cruz, Javier; Borja-de-la-Rosa, Amparo; Barragán-Huerta, Blanca E

    2016-01-01

    Peltomexicanin (7,10-dihydroxy-6,12-dioxa-5H-tetraphen-3-one) is a new peltogynoid quinone methide isolated from Palo Morado (Peltogyne mexicana Martínez) heartwood by column chromatography. Its chemical structure was elucidated by IR, NMR (¹H, (13)C), 2D NMR experiments (COSY, NOESY, HMQC, and HSQC), ESI-MS, and UV-Vis spectroscopic analysis. According to HPLC quantification, this compound is the main pigment and accounts for 1.21% of Palo Morado heartwood material. The antioxidant activity of peltomexicanin and dried methanolic extract (DEx) of purple heartwood was evaluated using the radical of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, and the corresponding values expressed as Trolox equivalents (µmol TE/mg sample) were 4.25 and 4.57, respectively. PMID:26861267

  4. Characterization and Prebiotic Effect of the Resistant Starch from Purple Sweet Potato.

    PubMed

    Zheng, Yafeng; Wang, Qi; Li, Baoyu; Lin, Liangmei; Tundis, Rosa; Loizzo, Monica R; Zheng, Baodong; Xiao, Jianbo

    2016-01-01

    Purple sweet potato starch is a potential resource for resistant starch production. The effects of heat-moisture treatment (HMT) and enzyme debranching combined heat-moisture treatment (EHMT) on the morphological, crystallinity and thermal properties of PSP starches were investigated. The results indicated that, after HMT or EHMT treatments, native starch granules with smooth surface was destroyed to form a more compact, irregular and sheet-like structure. The crystalline pattern was transformed from C-type to B-type with decreasing relative crystallinity. Due to stronger crystallites formed in modified starches, the swelling power and solubility of HMT and EHMT starch were decreased, while the transition temperatures and gelatinization enthalpy were significantly increased. In addition, HMT and EHMT exhibited greater effects on the proliferation of bifidobacteria compared with either glucose or high amylose maize starch. PMID:27447598

  5. Electronic Structures of Purple Bronze KMo6O17 Studied by X-Ray Photoemission Spectra

    NASA Astrophysics Data System (ADS)

    Qin, Xiaokui; Wei, Junyin; Shi, Jing; Tian, Mingliang; Chen, Hong; Tian, Decheng

    X-ray photoemission spectroscopy study has been performed for the purple bronze KMo6O17. The structures of conduction band and valence band are analogous to the results of ultraviolet photoemission spectra and are also consistent with the model of Travaglini et al., but the gap between conduction and valence band is insignificant. The shape of asymmetric and broadening line of O-1s is due to unresolved contributions from the many inequivalent oxygen sites in this crystal structure. Mo 3d core-level spectrum reveals that there are two kinds of valence states of Molybdenum (Mo+5 and Mo+6). The calculated average valence state is about +5.6, which is consistent with the expectation value from the composition of this material. The tail of Mo-3d spectrum toward higher binding energy is the consequence of the excitation of electron-hole pairs with singularity index of 0.21.

  6. Reduction of MTT to Purple Formazan by Vitamin E Isomers in the Absence of Cells

    PubMed Central

    Lim, Su-Wen; Loh, Hwei-San; Ting, Kang-Nee; Bradshaw, Tracey Dawn; Allaudin, Zeenathul Nazariah

    2015-01-01

    The yellow tetrazolium salt 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) is widely used to determine cell viability in cell proliferation and cytotoxic assays. MTT is reduced by metabolically active cells to form an insoluble purple formazan product that is quantifiable by spectrophotometry. It is the most common and direct assay for cell viability. However, in this present study, we demonstrated that the vitamin E isomers α-β-γ-δ-tocotrienols and α-tocopherol were able to reduce MTT into a formazan product, despite the absence of living cells. For comparison, a second method for determining cell viability, which is the neutral red uptake assay, was used in parallel with the MTT assay. The results showed that neutral red did not interact with the vitamin E isomers. Our findings suggest that the MTT assay is not suitable for studying the proliferative effects of vitamin E isomers on cell growth. PMID:26868595

  7. Applications of the Phytomedicine Echinacea purpurea (Purple Coneflower) in Infectious Diseases

    PubMed Central

    Hudson, James B.

    2012-01-01

    Extracts of Echinacea purpurea (EP, purple coneflower) have been used traditionally in North America for the treatment of various types of infections and wounds, and they have become very popular herbal medicines globally. Recent studies have revealed that certain standardized preparations contain potent and selective antiviral and antimicrobial activities. In addition, they display multiple immune-modulatory activities, comprising stimulation of certain immune functions such as phagocytic activity of macrophages and suppression of the proinflammatory responses of epithelial cells to viruses and bacteria, which are manifested as alterations in secretion of various cytokines and chemokines. These immune modulations result from upregulation or downregulation of the relevant genes and their transcription factors. All these bioactivities can be demonstrated at noncytotoxic concentrations of extract and appear to be due to multiple components rather than the individual chemical compounds that characterize Echinacea extracts. Potential applications of the bioactive extracts may go beyond their traditional uses. PMID:22131823

  8. Antioxidant effects of gastrointestinal digested purple carrot extract on the human cells of colonic mucosa.

    PubMed

    Olejnik, Anna; Rychlik, Joanna; Kidoń, Marcin; Czapski, Janusz; Kowalska, Katarzyna; Juzwa, Wojciech; Olkowicz, Mariola; Dembczyński, Radosław; Moyer, Mary Pat

    2016-01-01

    Purple carrot (PC) is a potential dietary constituent, which represents a valuable source of antioxidants and can modulate the reactive oxygen species (ROS) level in the gastrointestinal tract. Antioxidant capacity of a PC extract subjected to digestion process simulated in the artificial alimentary tract, including the stomach, small intestine and colon, was analyzed in normal human cells of colon mucosa. Results indicated that the extract obtained upon passage through the gastrointestinal tract, which could come into contact with the colonic cells in situ, was less potent than the extract, which was not subjected to digestion process. Digested PC extract exhibited intracellular ROS-inhibitory capacity, with 1mg/mL showing the ROS clearance of 18.4%. A 20.7% reduction in oxidative DNA damage due to colon mucosa cells' treatment with digested PC extract was observed. These findings indicate that PC extract is capable of colonic cells' protection against the adverse effects of oxidative stress. PMID:26213078

  9. Triplet excited state spectra and dynamics of carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum

    SciTech Connect

    Niedzwiedzki, Dariusz; Kobayashi, Masayuki; Blankenship, R. E.

    2011-01-13

    Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll-a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll-a Q{sub x} band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.

  10. Purple phototrophic bacterium enhances stevioside yield by Stevia rebaudiana Bertoni via foliar spray and rhizosphere irrigation.

    PubMed

    Wu, Jing; Wang, Yiming; Lin, Xiangui

    2013-01-01

    This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant (-1) by 69.2% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms. PMID:23825677

  11. A Case of Purple Urine Bag Syndrome in a Spastic Partial Quadriplegic Male.

    PubMed

    Tul Llah, Sibghat; Khan, Salman; Dave, Atman; Morrison, Amelia Jane A; Jain, Swapna; Hermanns, David

    2016-01-01

    Purple bag urine syndrome (PUBS) is a benign and unique phenomenon of the urine turning a deep violet color within the urinary catheter tubing and bag. This phenomenon is commonly encountered in patients indicated with long-term catheter placement or, in certain conditions like chronic constipation, alkaline urine, limited ambulation, and, in terms of gender distribution, the female sex, predominates. PUBS gets its name from a unique phenomenon that takes places inside the gut where tryptophan (an amino acid) is metabolized, producing blue and red hues which together emanate a deep violet color. Here, the case of a middle-aged male patient with a suprapubic catheter in situ, following trauma causing spastic partial quadriplegia, is being presented with PUBS due to UTI secondary to Proteus vulgaris. The risk factors, in this case, include chronic constipation and recurrent urinary tract infections (UTIs).​. PMID:27182466

  12. Microencapsulation of purple Brazilian cherry juice in xanthan, tara gums and xanthan-tara hydrogel matrixes.

    PubMed

    Rutz, Josiane K; Zambiazi, Rui C; Borges, Caroline D; Krumreich, Fernanda D; da Luz, Suzane R; Hartwig, Naralice; da Rosa, Cleonice G

    2013-11-01

    The purple Brazilian cherry (Eugenia uniflora L.) juice was encapsulated in xanthan, tara and xanthan-tara hydrogel matrixes. Encapsulation efficiency, Differential Scanning Calorimetry (DSC), X-ray diffractometry, release profile, stability of carotenoids, phenolic compounds and antioxidant activity of microparticles were evaluated. Encapsulation was confirmed. The highest encapsulation efficiency was obtained with xanthan gum and hydrogel was mostly indicated for the release of carotenoids in GFS and IFS medium. Phenolic compounds had the highest release rate but not in a gradually way, regardless of wall material and fluids under analysis. Stored microparticles at 4 and 25 °C, showed carotenoid degradation. Xanthan and hydrogel wall material provided the greatest stability to these compounds. The microparticles' anti-oxidant activity decreased during storage due to the degradation of carotenoids. PMID:24053801

  13. Excitonic energy transfer in light-harvesting complexes in purple bacteria

    NASA Astrophysics Data System (ADS)

    Ye, Jun; Sun, Kewei; Zhao, Yang; Yu, Yunjin; Kong Lee, Chee; Cao, Jianshu

    2012-06-01

    Two distinct approaches, the Frenkel-Dirac time-dependent variation and the Haken-Strobl model, are adopted to study energy transfer dynamics in single-ring and double-ring light-harvesting (LH) systems in purple bacteria. It is found that the inclusion of long-range dipolar interactions in the two methods results in significant increase in intra- or inter-ring exciton transfer efficiency. The dependence of exciton transfer efficiency on trapping positions on single rings of LH2 (B850) and LH1 is similar to that in toy models with nearest-neighbor coupling only. However, owing to the symmetry breaking caused by the dimerization of BChls and dipolar couplings, such dependence has been largely suppressed. In the studies of coupled-ring systems, both methods reveal an interesting role of dipolar interactions in increasing energy transfer efficiency by introducing multiple intra/inter-ring transfer paths. Importantly, the time scale (4 ps) of inter-ring exciton transfer obtained from polaron dynamics is in good agreement with previous studies. In a double-ring LH2 system, non-nearest neighbor interactions can induce symmetry breaking, which leads to global and local minima of the average trapping time in the presence of a non-zero dephasing rate, suggesting that environment dephasing helps preserve quantum coherent energy transfer when the perfect circular symmetry in the hypothetic system is broken. This study reveals that dipolar coupling between chromophores may play an important role in the high energy transfer efficiency in the LH systems of purple bacteria and many other natural photosynthetic systems.

  14. Spectral effects of LEDs on chlorophyll fluorescence and pigmentation in Phalaenopsis 'Vivien' and 'Purple Star'.

    PubMed

    Ouzounis, Theoharis; Fretté, Xavier; Ottosen, Carl-Otto; Rosenqvist, Eva

    2015-06-01

    We examined the effect of light emitting diode (LED) lighting in greenhouse facilities on growth, chlorophyll fluorescence and pigmentation in Phalaenopsis 'Vivien' and 'Purple Star' under purpose-built LED arrays yielding c. 200 µmol m(-2)  s(-1) at plant height for 14 h per day and 24/18°C day/night temperature, respectively, from January to April 2013. The light treatments were (1) 40% blue in 60% red (40% B/R), (2) 0% blue in 100% red (0% B/R) and (3) white LEDs with 32% blue in white (32% B/W, control), with background daylight under shade screens. The plants were harvested twice for leaf growth and pigmentation. There was no clear pattern in the spectral effect on growth since the order of leaf size differed between harvests in March and April. Fv /Fm was in the range of 0.52-0.72, but overall slightly higher in the control, which indicated a permanent downregulation of PSII in the colored treatments. The fluorescence quenching showed no acclimation to color in 'Purple Star', while 'Vivien' had lower ETR and higher NPQ in the 40% B/R, resembling low light acclimation. The pigmentation showed corresponding spectral response with increasing concentration of lutein while increasing the fraction of blue light, which increased the light absorption in the green/yellow part of the spectrum. The permanent downregulation of PSII moved a substantial part of the thermal dissipation from the light regulated NPQ to non-regulated energy losses estimated by ΦNPQ and ΦNO and the difference found in the balance between ΦPSII and ΦNPQ in 'Vivien' disappeared when ΦNO was included in the thermal dissipation. PMID:25302638

  15. An experimental study of rill sediment delivery in purple soil, using the volume-replacement method

    PubMed Central

    Huang, Yuhan; Luo, Banglin; Ding, Linqiao; Gong, Chunming

    2015-01-01

    Experimental studies provide a basis for understanding the mechanisms of rill erosion and can provide estimates for parameter values in physical models simulating the erosion process. In this study, we investigated sediment delivery during rill erosion in purple soil. We used the volume-replacement method to measure the volume of eroded soil and hence estimate the mass of eroded soil. A 12 m artificial rill was divided into the following sections: 0–0.5 m, 0.5–1 m, 1–2 m, 2–3 m, 3–4 m, 4–5 m, 5–6 m, 6–7 m, 7–8 m, 8–10 m, and 10–12 m. Erosion trials were conducted with three flow rates (2 L/min, 4 L/min, and 8 L/min) and five slope gradients (5°, 10°, 15°, 20°, and 25°). The eroded rill sections were refilled with water to measure the eroded volume in each section and subsequently calculate the eroded sediment mass. The cumulative sediment mass was used to compute the sediment concentration along the length of the rill. The results show that purple soil sediment concentration increases with rill length before eventually reaching a maximal value; that is, the rate of increase in sediment concentration is greatest at the rill inlet and then gradually slows. Steeper slopes and higher flow rates result in sediment concentration increasing more rapidly along the rill length and the maximum sediment concentration being reached at an earlier location in the rill. Slope gradient and flow rate both result in an increase in maximal sediment concentration and accumulated eroded amount. However, slope gradient has a greater influence on rill erosion than flow rate. The results and experimental method in this study may provide a reference for future rill-erosion experiments. PMID:26734498

  16. Biosynthesis and Isotopic Composition of Bacteriochlorophyll a and Okenone in Purple Sulfur Bacteria

    NASA Astrophysics Data System (ADS)

    Smith, D.; Scott, J. H.; Steele, A.; Cody, G. D.; Ohara, S.; Bowden, R.; Fogel, M. L.

    2011-12-01

    Phototrophic sulfur bacteria play an integral part in the anaerobic cycling of sulfur. Bacteriochloroyphll a (Bchl a) is a well-studied photosynthetic compound required for photosynthesis in the organisms that possess it. The only known fossil of purple sulfur bacteria (PSB) in the geologic record is okenane, believed to be of biologic origin originating from the carotenoid pigment okenone, which has only been documented in eleven species of Chromatiaceae. Organic geochemical studies have identified okenane in preserved organic matter in rocks and ancient sediments and further, okenone production has been observed in modern water columns and sediment surfaces. We have undertaken a comprehensive study on the biosynthesis of bacterial pigments including okenone and C, N, and S isotopic fractionation during various growth modes in controlled laboratory experiments of purple sulfur bacteria. Cultures of Marichromatium purpuratum 1591, M. purpuratum 1711, Thiocapsa marina 5653, and FGL21 (isolated from the chemocline of Fayetteville Green Lake, NY) were grown under autotrophic and photoheterotrophic (e.g. acetate or pyruvate) conditions in batch cultures. Concentrations of okenone and Bchl a were quantified as a function of time and growth by Ultra Performance-Liquid Chromatography-Mass Spectrometry (UP-LC-MS) and spectrophotometry. Overall okenone and Bchl a concentrations reached μM levels in the cultures. At stationary phase, all four strains achieved concentrations of okenone and Bchl a that were approximately 2.5 fM and 0.2 fM per cell, respectively, with okenone to Bchl a ratios of approximately 12 to 1. Isotope Ratio Mass Spectrometry (IRMS) was performed on bulk cells and compound specific analysis of Bchl a and okenone to better understand the fractionation associated with the production of the compounds.

  17. Purple perilla extracts with α-asarone enhance cholesterol efflux from oxidized LDL-exposed macrophages.

    PubMed

    Park, Sin-Hye; Paek, Ji Hun; Shin, Daekeun; Lee, Jae-Yong; Lim, Soon Sung; Kang, Young-Hee

    2015-04-01

    The cellular accumulation of cholesterol is critical in the development and progression of atherosclerosis. ATP-binding cassette (ABC) transporters play an essential role in mediating the efflux of excess cholesterol. In the current study, we investigated whether purple Perilla frutescens extracts (PPE) at a non-toxic concentration of 1-10 µg/ml stimulate the induction of the ABC transporters, ABCA1 and ABCG1, and cholesterol efflux from lipid-laden J774A.1 murine macrophages exposed to 50 ng/ml oxidized low-density lipoprotein (LDL). Purple perilla, an annual herb in the mint family and its constituents, have been reported to exhibit antioxidant and cytostatic activity, as well as to exert anti-allergic effects. Our results revealed that treatment with oxidized LDL for 24 h led to the accumulation of lipid droplets in the macrophages. PPE suppressed the oxidized LDL-induced foam cell formation by blocking the induction of scavenger receptor B1. However, PPE promoted the induction of the ABC transporters, ABCA1 and ABCG1, and subsequently accelerated cholesterol efflux from the lipid-loaded macrophages. The liver X receptor (LXR) agonist, TO-091317, and the peroxisome proliferator-activated receptor (PPAR) agonist, pioglitazone, increased ABCA1 expression and treatment with 10 µg/ml PPE further enhanced this effect. PPE did not induce LXRα and PPARγ expression per se, but enhanced their expression in the macrophages exposed to oxidized LDL. α-asarone was isolated from PPE and characterized as a major component enhancing the induction of ABCA1 and ABCG1 in macrophages exposed to oxidized LDL. α-asarone, but not β-asarone was effective in attenuating foam cell formation and enhancing cholesterol efflux, revealing an isomeric difference in their activity. The results from the present study demonstrate that PPE promotes cholesterol efflux from macrophages by activating the interaction of PPARγ-LXRα-ABC transporters. PMID:25673178

  18. Is it turquoise + fuchsia = purple or is it turquoise + fuchsia = blue?

    NASA Astrophysics Data System (ADS)

    Beretta, Giordano B.; Moroney, Nathan M.

    2011-01-01

    The first step in communicating color is to name it. The second step is color semiotics. The third step is introducing structure in the set of colors. In color education at all levels, this structure often takes the form of formulæ, like red + green = yellow, or turquoise + red = black. In recent times, Johannes Itten's color theory and its associated color wheel have been very influential, mostly through its impact on Bauhaus, although a number of color order systems and circles have been introduced over the centuries. Students get confused when they are trying to formulate the color name arithmetic using the structure of color order systems and concepts like complementary colors and opponent colors. Suddenly turquoise + fuchsia = purple instead of blue; purple and violet become blurred, and finally the student's head explodes under the epistemological pressures of Itten, Albers, Goethe, Runge, Newton, da Vinci, and all the other monsters of color structure. In this contribution we propose a systematic presentation of structure in color, from color theories to color naming. We start from the concept of color perception introduced by da Vinci and work ourselves through color measurement, color formation, and color naming, to develop the basis for a robust system based on table lookup and interpolation. One source of confusion is that color naming has been quite loose in color theory, where for example red can be used interchangeably with fuchsia, and blue with turquoise. Furthermore, common color terms are intermingled with technical colorant terms, for example cyan and aqua or fuchsia and magenta. We present the evolution of a few color terms, some of which have experienced a radical transition over the centuries, and describe an experiment showing the robustness of crowd-sourcing for color naming.

  19. Plasma biochemistry values of recently wild-caught purple mouth moray eels (Gymnothorax vicinus).

    PubMed

    Erlacher-Reid, Claire; Hoffman, Walter E; Priede, Megan; Pulver, Robert; Tuttle, Allison D

    2011-12-01

    The primary purpose of this study was to establish plasma biochemistry parameters for healthy recently wild-caught purple mouth moray eels (Gymnothorax vicinus) to provide a baseline of data for improved medical care in an aquarium or zoologic setting and for wild health assessments. Thirty-one clinically healthy purple mouth moray eels of unknown age and sex were caught from the wild, and were anesthetized 50 days following capture for blood collection from the ventral coccygeal vein. The median plasma biochemistry values were as follows: hematocrit = 21%, creatinine kinase = 2,100 U/L, lactate dehydrogenase = 97 U/L, aspartate aminotransferase = 88 U/L, alanine aminotransferase = 51 U/L, alkaline phosphatase 3,939 U/L, gamma-glutamyl transpeptidase = 1 U/L, amylase = 40 U/L, blood urea nitrogen = < 11 mg/dl, glucose = 21 mg/dl, calcium = 12.5 mg/dl, triglyceride = 206 mg/dl, creatinine = 0.1 mg/dl, cholesterol = 334 mg/dl, total bilirubin = < 0.1 mg/dl, phosphorus = 6.5 mg/dl, total protein = 4.2 g/dl, albumin = 1.5 g/dl, globulin = 2.7 g/dl, albumin/ globulin ratio = 0.6, sodium = 185 mmol/L, potassium = 3.7 mmol/L, and chloride = 175 mmol/L. Alkaline phosphatase isoenzyme results indicate that the majority of the plasma alkaline phosphatase is the liver isoenzyme. The data acquired in this study also provide baseline values for cholesterol and triglycerides in recently wild-caught moray eels to aid in monitoring elevations to these values in an aquarium setting over time so adjustments to the dietary regime may be utilized to prevent or improve conditions such as lipid keratopathy. PMID:22204062

  20. Anthocyanin-rich purple corn extract inhibit diabetes-associated glomerular angiogenesis.

    PubMed

    Kang, Min-Kyung; Lim, Soon Sung; Lee, Jae-Yong; Yeo, Kyung Mok; Kang, Young-Hee

    2013-01-01

    Diabetic nephropathy (DN) is one of the major diabetic complications and the leading cause of end-stage renal disease. Abnormal angiogenesis results in new vessels that are often immature and play a pathological role in DN, contributing to renal fibrosis and disrupting glomerular failure. Purple corn has been utilized as a daily food and exerts disease-preventive activities. This study was designed to investigate whether anthocyanin-rich purple corn extract (PCE) prevented glomerular angiogenesis under hyperglycemic conditions. Human endothelial cells were cultured in conditioned media of mesangial cells exposed to 33 mM high glucose (HG-HRMC-CM). PCE decreased endothelial expression of vascular endothelial growth factor (VEGF) and hypoxia inducible factor (HIF)-1α induced by HG-HRMC-CM. Additionally, PCE attenuated the induction of the endothelial marker of platelet endothelial cell adhesion molecule (PECAM)-1 and integrin β3 enhanced in HG-HRMC-CM. Endothelial tube formation promoted by HG-HRMC-CM was disrupted in the presence of PCE. In the in vivo study employing db/db mice treated with 10 mg/kg PCE for 8 weeks, PCE alleviated glomerular angiogenesis of diabetic kidneys by attenuating the induction of VEGF and HIF-1α. Oral administration of PCE retarded the endothelial proliferation in db/db mouse kidneys, evidenced by its inhibition of the induction of vascular endothelium-cadherin, PECAM-1 and Ki-67. PCE diminished the mesangial and endothelial induction of angiopoietin (Angpt) proteins under hypeglycemic conditions. The induction and activation of VEGF receptor 2 (VEGFR2) were dampened by treating PCE to db/db mice. These results demonstrate that PCE antagonized glomerular angiogenesis due to chronic hyperglycemia and diabetes through disturbing the Angpt-Tie-2 ligand-receptor system linked to renal VEGFR2 signaling pathway. Therefore, PCE may be a potent therapeutic agent targeting abnormal angiogenesis in DN leading to kidney failure. PMID:24278186

  1. Unraveling the size distributions of surface properties for purple soil and yellow soil.

    PubMed

    Tang, Ying; Li, Hang; Liu, Xinmin; Zhu, Hualing; Tian, Rui

    2015-06-01

    Soils contain diverse colloidal particles whose properties are pertinent to ecological and human health, whereas few investigations systematically analyze the surface properties of these particles. The objective of this study was to elucidate the surface properties of particles within targeted size ranges (i.e. >10, 1-10, 0.5-1, 0.2-0.5 and <0.2 μm) for a purple soil (Entisol) and a yellow soil (Ultisol) using the combined determination method. The mineralogy of corresponding particle-size fractions was determined by X-ray diffraction. We found that up to 80% of the specific surface area and 85% of the surface charge of the entire soil came from colloidal-sized particles (<1 μm), and almost half of the specific surface area and surface charge came from the smallest particles (<0.2 μm). Vermiculite, illite, montmorillonite and mica dominated in the colloidal-sized particles, of which the smallest particles had the highest proportion of vermiculite and montmorillonite. For a given size fraction, the purple soil had a larger specific surface area, stronger electrostatic field, and higher surface charge than the yellow soil due to differences in mineralogy. Likewise, the differences in surface properties among the various particle-size fractions can also be ascribed to mineralogy. Our results indicated that soil surface properties were essentially determined by the colloidal-sized particles, and the <0.2 μm nanoparticles made the largest contribution to soil properties. The composition of clay minerals within the diverse particle-size fractions could fully explain the size distributions of surface properties. PMID:26040734

  2. Purple sweet potato anthocyanin attenuates fat-induced mortality in Drosophila melanogaster.

    PubMed

    Wang, Lijun; Li, Yuk Man; Lei, Lin; Liu, Yuwei; Wang, Xiaobo; Ma, Ka Ying; Zhang, Chengnan; Zhu, Hanyue; Zhao, Yimin; Chen, Zhen-Yu

    2016-09-01

    A high fat diet induces the accumulation of lipid hydroperoxides (LPO), accelerates the ageing process and causes a greater mortality in Drosophila melanogaster. Purple sweet potato is rich in antioxidant anthocyanin. The purpose of the present study was to examine if supplementation of purple sweet potato anthocyanin (PSPA) could reduce the mortality of fruit flies fed a high-fat diet. Results showed that the mean lifespan of fruit flies was shortened from 56 to 35days in a dose-dependent manner when lard in the diet increased from 0% to 20%. PSPA supplementation partially attenuated the lard-induced mortality. The maximum lifespan and 50% survival time were 49 and 27days, respectively, for the 10% lard control flies, in contrast, these parameters increased to 57 and 30days in the PSPA-supplemented fruit flies. Similarly, addition of lard into diet increased the total body LPO, while addition of PSPA partially attenuated its increase. Real-time PCR analysis indicated that PSPA-supplemented diet significantly up-regulated the mRNA of superoxide dismutase (SOD), catalase (CAT) and Rpn11, compared with the control lard diet. The western blot analysis also demonstrated that PSPA supplementation was associated with up-regulation protein mass of SOD1, SOD2, and CAT. In addition, PSPA supplementation could restore the climbing ability of fruit flies fed a 10% lard diet. We could conclude that the lifespan-prolonging activity of PSPA was potentially mediated by modulating the genes of SOD, CAT and Rpn11. PMID:27329928

  3. Fragmentation and ablation during entry

    SciTech Connect

    Canavan, G.H.

    1997-09-01

    This note discusses objects that both fragment and ablate during entry, using the results of previous reports to describe the velocity, pressure, and fragmentation of entering objects. It shows that the mechanisms used there to describe the breakup of non-ablating objects during deceleration remain valid for most ablating objects. It treats coupled fragmentation and ablation during entry, building on earlier models that separately discuss the entry of objects that are hard, whose high heat of ablation permits little erosion, and those who are strong whose strength prevents fragmentation, which are discussed in ``Radiation from Hard Objects,`` ``Deceleration and Radiation of Strong, Hard, Asteroids During Atmospheric Impact,`` and ``Meteor Signature Interpretation.`` This note provides a more detailed treatment of the further breakup and separation of fragments during descent. It replaces the constraint on mass per unit area used earlier to determine the altitude and magnitude of peak power radiation with a detailed analytic solution of deceleration. Model predictions are shown to be in agreement with the key features of numerical calculations of deceleration. The model equations are solved for the altitudes of maximum radiation, which agree with numerical integrations. The model is inverted analytically to infer object size and speed from measurements of peak power and altitude to provide a complete model for the approximate inversion of meteor data.

  4. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  5. Membranous nephropathy

    MedlinePlus

    ... to reduce cholesterol and triglyceride levels (most often statins) may be recommended. A low-salt diet may ... of membranous nephropathy Your symptoms get worse or don't go away You develop new symptoms You have ...

  6. Membrane characteristics for biological blast overpressure testing using blast simulators.

    PubMed

    Alphonse, Vanessa D; Siva Sai Sujith Sajja, Venkata; Kemper, Andrew R; Rizel, Dave V; Duma, Stefan M; VandeVord, Pamela J

    2014-01-01

    Blast simulators often use passive-rupture membranes to generate shock waves similar to free-field blasts. The purpose of this study was to compare rupture patterns and pressure traces of three distinct membrane materials for biological and biomechanical blast studies. An Advanced Blast Simulator (ABS) located at the Center for Injury Biomechanics at Virginia Tech was used to test membrane characteristics. Acetate, Mylar, and aluminum sheets with different thicknesses were used to obtain pressures between 70–210 kPa. Static pressure was measured inside the tube at the test section using piezoelectric pressure sensors. Peak overpressure, positive duration, and positive impulse were calculated for each test. Rupture patterns and characteristic pressure traces were unique to each membrane type and thickness. Shock wave speed ranged between 1.2-1.8 Mach for static overpressures of 70–210 kPa. Acetate membranes fragmented sending pieces down the tube, but produced ideal (Friedlander) pressure traces. Mylar membranes bulged without fragmenting, but produced less-than-ideal pressure traces. Aluminum membranes did not fragment and produced ideal pressure traces. However, the cost of manufacturing and characterizing aluminum membranes should be considered during membrane selection. This study illustrates the advantages and disadvantages of using Mylar, acetate, and aluminum for passive rupture membranes for blast simulators. PMID:25405432

  7. pH-dependence of the phospholipid interaction of diphtheria-toxin fragments.

    PubMed Central

    Montecucco, C; Schiavo, G; Tomasi, M

    1985-01-01

    Photoreactive phospholipids have been used to probe the lipid interaction of diphtheria toxin. Low pH values induce the membrane insertion of both the binding and enzymic fragments of the toxin. The efficiency of this process is much higher with asolectin than with egg lecithin (phosphatidylcholine)/cholesterol liposomes. The low-pH-induced interaction of the toxin fragments with the membrane hydrocarbon phase is more evident for the enzymic A-chain than for the binding B-chain, and it is fully reversed by returning the pH to neutrality. PMID:4062882

  8. Biological restorations using tooth fragments.

    PubMed

    Busato, A L; Loguercio, A D; Barbosa, A N; Sanseverino, M do C; Macedo, R P; Baldissera, R A

    1998-02-01

    A "biological" restoration technique using dental fragments and adhesive materials is described. These fragments were obtained from extracted human teeth which had been previously sterilized and stored in a tooth bank. The advantages are: the use of extracted teeth as restorative material, esthetics, and treatment cost. The positive sensation of having back the missing tooth was the most mentioned comment among patients. The disadvantages are: the difficulty of obtaining teeth with the needed characteristics, problems of making an indirect restoration, matching the original color, and the non-acceptance by some patients who consider it strange to have other people's teeth placed in their mouths. PMID:9823086

  9. OMA1 mediates OPA1 proteolysis and mitochondrial fragmentation in experimental models of ischemic kidney injury

    PubMed Central

    Xiao, Xiao; Hu, Yanzhong; Quirós, Pedro M.; Wei, Qingqing; López-Otín, Carlos

    2014-01-01

    Acute kidney injury (AKI) is associated with mitochondrial fragmentation, which contributes to mitochondrial damage and tubular cell apoptosis. Mitochondrial fragmentation involves the cleavage of both mitochondrial outer and inner membranes. Cleavage of the outer membrane results from Drp-1-mediated fission activation and Bak-promoted fusion arrest, but the molecular mechanism of inner membrane cleavage remains elusive. OMA1-mediated proteolysis of OPA1, a key inner membrane fusion protein, was recently suggested to account for inner membrane cleavage during cell stress. In this study, we determined the role of OMA1 in OPA1 proteolysis and mitochondrial fragmentation in experimental models of ischemic AKI. In ATP-depletion injury, knockdown of OMA1 suppressed OPA1 proteolysis, mitochondrial fragmentation, cytochrome c release, and consequent apoptosis in renal proximal tubular cells. In mice, OMA1 deficiency prevented ischemic AKI as indicated by better renal function, less tubular damage, and lower apoptosis. OPA1 proteolysis and mitochondrial injury during ischemic AKI were ameliorated in OMA1-deficient mice. Thus, OMA1-mediated OPA1 proteolysis plays an important role in the disruption of mitochondrial dynamics in ischemic AKI. PMID:24671334

  10. Nuclear energy release from fragmentation

    NASA Astrophysics Data System (ADS)

    Li, Cheng; Souza, S. R.; Tsang, M. B.; Zhang, Feng-Shou

    2016-08-01

    It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting 230,232Th and 235,238U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for 230,232Th and 235,238U are around 0.7-0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.

  11. Percolative fragmentation and spontaneous agglomeration

    SciTech Connect

    Hurt, R.; Davis, K.

    1999-03-01

    Captive particle imaging experiments were performed on over 200 coal and char particles in the pulverized size range from four coals of various rank at oxygen concentration from 3--19 mol% and at gas temperatures of about 1250 K. Despite wide variations in single-particle behavior, the data set reveals two clear trends that provide new information on the nature of char combustion. First, the low-rank coal chars are observed to maintain their high reactivity through the late stages of combustion, thus avoiding the near-extinction events and long burnout tails observed for bituminous coal chars. Secondly, percolative fragmentation in the late stages of combustion is a rare event under these conditions. Some particles reach a percolation threshold rate in combustion, but typically undergo spontaneous agglomeration rather than liberation of the incipient fragments. It is concluded that percolative fragmentation behavior in the pulverized size range is determined not only by solid-phase connectivity, but also by a real competition between disruptive and cohesive forces present at the time of formation of the colloidal-sized incipient fragments.

  12. Fission fragment driven neutron source

    DOEpatents

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  13. Economical technique for fragmentation testing

    NASA Technical Reports Server (NTRS)

    Smith, T. H., III; Snoke, B. A.

    1974-01-01

    Automatic rifle was modified for remote, single-shot use. To simulate statistically--determined fragment size from rocket-motor casing blunt-nosed bullet was made of same alloy. Cartridge was loaded with enough powder to make bullet reach target at same estimated velocity as shrapnel from rocket casing.

  14. Functional Assembly of Protein Fragments Induced by Spatial Confinement

    PubMed Central

    Yu, Yongsheng; Wang, Jianpeng; Liu, Jiahui; Ling, Daishun; Xia, Jiang

    2015-01-01

    Natural proteins are often confined within their local microenvironments, such as three-dimensional confinement in organelles or two-dimensional confinement in lipid rafts on cytoplasmic membrane. Spatial confinement restricts proteins' entropic freedom, forces their lateral interaction, and induces new properties that the same proteins lack at the soluble state. So far, the phenomenon of environment-induced protein functional alteration still lacks a full illustration. We demonstrate here that engineered protein fragments, although being non-functional in solution, can be re-assembled within the nanometer space to give the full activity of the whole protein. Specific interaction between hexahistidine-tag (His-tag) and NiO surface immobilizes protein fragments on NiO nanoparticles to form a self-assembled protein "corona" on the particles inside the nanopores of mesoporous silica. Site-specific assembly forces a shoulder-by-shoulder orientation and promotes fragment−fragment interaction; this interaction together with spatial confinement of the mesopores results in functional re-assembly of the protein half fragments. To our surprise, a single half fragment of luciferase (non-catalytic in solution) exhibited luciferase activity when immobilized on NiO in the mesopores, in the absence of the complimentary half. This shows for the first time that spatial confinement can induce the folding of a half fragment, reconstitute the enzyme active site, and re-gain the catalytic capability of the whole protein. Our work thereby highlights the under-documented notion that aside from the chemical composition such as primary sequence, physical environment of a protein also determines its function. PMID:25875003

  15. Effects of elevated atmospheric CO2 on invasive plants: comparison of purple and yellow nutsedge (Cyperus rotundus L. and C. esculentus L.).

    PubMed

    Rogers, H H; Runion, G B; Prior, S A; Price, A J; Torbert, H A; Gjerstad, D H

    2008-01-01

    The rise in atmospheric CO(2) concentration coupled with its direct, often positive, effect on the growth of plants raises the question of the response of invasive plants to elevated atmospheric CO(2) levels. Response of two invasive weeds [purple nutsedge (Cyperus rotundus L.) and yellow nutsedge (Cyperus esculentus L.)] to CO(2) enrichment was tested. Plants were exposed to ambient (375 micromol mol(-1)) or elevated CO(2) (ambient + 200 micromol mol(-1)) for 71 d in open top chambers. Photosynthetic rate did not differ between CO(2) treatments for either species. Conductance was lower in purple nutsedge and tended to be lower in yellow nutsedge. Purple nutsedge had higher instantaneous water use efficiency; a similar trend was noted for yellow nutsedge. Purple nutsedge had greater leaf area, root length and numbers of tubers and tended to have more tillers under high CO(2). In yellow nutsedge, only tuber number increased under CO(2) enrichment. Leaf dry weight was greater for both species when grown under elevated CO(2). Only purple nutsedge made seed heads; CO(2) level did not change seed head dry weight. Root dry weight increased under the high CO(2) treatment for purple nutsedge only, but tuber dry weight increased for both. Total dry weight of both species increased at elevated CO(2). Purple nutsedge (under elevated CO(2)) tended to increase allocation belowground, which led to greater root-to-shoot ratio (R:S); R:S of yellow nutsedge was unaffected by CO(2) enrichment. Findings suggest both species, purple more than yellow nutsedge, may be more invasive in a future high-CO(2) world. PMID:18268302

  16. Fragmentation in the First Galaxies

    NASA Astrophysics Data System (ADS)

    Safranek-Shrader, Chalence; Bromm, Volker; Milosavljević, Miloš

    2010-11-01

    Motivated by recent simulations of galaxy formation in which protogalaxies acquire their baryonic content through cold accretion, we study the gravitational fragmentation of cold streams flowing into a typical first galaxy. We use a one-zone hydrodynamical model to examine the thermal evolution of the gas flowing into a 108 M sun dark matter halo at redshift z = 10. The goal is to gain an understanding of the expected fragmentation mass scale and thus the characteristic mass of the first population of stars to form by shock fragmentation. Our model accurately describes the chemical and thermal evolution of the gas as we are specifically concerned with how the chemical abundances and initial conditions of the low-density, metal-enriched, cold accretion streams that pass an accretion shock alter the cooling properties and tendency to fragment in the post-shock gas. Cold accretion flows are not shock heated at the virial radius but instead flow along high-baryonic-density filaments of the cosmic web and penetrate deep into the host halo of the protogalaxy. In this physical regime, if molecular cooling is absent because of a strong Lyman-Werner background, we find there to be a sharp drop in the fragmentation mass at a metallicity of Z ~ 10-4 Z sun. If, however, H2 and HD molecules are present, they dominate the cooling at T < 104 K, and metallicity then has no effect on the fragmentation properties of the cold stream. For a solar abundance pattern of metallicity, O is the most effective metal coolant throughout the evolution, while for a pair instability supernova (PISN) metallicity yield, Si+ is the most effective coolant. PISN abundance patterns also exhibit a slightly smaller critical metallicity. Dust grains are not included in our chemical model, but we argue that their inclusion would not significantly alter the results. We also find that this physical scenario allows for the formation of stellar clusters and large, 104 M sun bound fragments, possibly the

  17. FRAGMENTATION IN THE FIRST GALAXIES

    SciTech Connect

    Safranek-Shrader, Chalence; Bromm, Volker; Milosavljevic, Milos

    2010-11-10

    Motivated by recent simulations of galaxy formation in which protogalaxies acquire their baryonic content through cold accretion, we study the gravitational fragmentation of cold streams flowing into a typical first galaxy. We use a one-zone hydrodynamical model to examine the thermal evolution of the gas flowing into a 10{sup 8} M{sub sun} dark matter halo at redshift z = 10. The goal is to gain an understanding of the expected fragmentation mass scale and thus the characteristic mass of the first population of stars to form by shock fragmentation. Our model accurately describes the chemical and thermal evolution of the gas as we are specifically concerned with how the chemical abundances and initial conditions of the low-density, metal-enriched, cold accretion streams that pass an accretion shock alter the cooling properties and tendency to fragment in the post-shock gas. Cold accretion flows are not shock heated at the virial radius but instead flow along high-baryonic-density filaments of the cosmic web and penetrate deep into the host halo of the protogalaxy. In this physical regime, if molecular cooling is absent because of a strong Lyman-Werner background, we find there to be a sharp drop in the fragmentation mass at a metallicity of Z {approx} 10{sup -4} Z{sub sun}. If, however, H{sub 2} and HD molecules are present, they dominate the cooling at T < 10{sup 4} K, and metallicity then has no effect on the fragmentation properties of the cold stream. For a solar abundance pattern of metallicity, O is the most effective metal coolant throughout the evolution, while for a pair instability supernova (PISN) metallicity yield, Si{sup +} is the most effective coolant. PISN abundance patterns also exhibit a slightly smaller critical metallicity. Dust grains are not included in our chemical model, but we argue that their inclusion would not significantly alter the results. We also find that this physical scenario allows for the formation of stellar clusters and large

  18. Electronic band structure and charge density wave transition in quasi-2D KMo6O17 purple bronze

    NASA Astrophysics Data System (ADS)

    Valbuena, M. A.; Avila, J.; Vyalikh, D. V.; Guyot, H.; Laubschat, C.; Molodtsov, S. L.; Asensio, M. C.

    2008-03-01

    High resolution angle-resolved photoemission of quasi-2D KMo6O17 purple bronze has been performed in the range from room temperature to 130 K, slightly above the charge density wave (CDW) transition (Tc = 110 K), and down to 35 K (well below Tc). In this paper we report a detailed study of how electronic band structure is affected by this transition driven by the hidden nesting scenario. The expected spectroscopic fingerprints of the CDW phase transition have been found and discussed according to the hidden one dimension and the development of a quasi-commensurate CDW. The excellent agreement between theory and our experimental results makes of potassium purple bronze a reference system for studying this type of instabilities.

  19. Purple photochromism in Sr2SnO4:Eu3+ with layered perovskite-related structure

    NASA Astrophysics Data System (ADS)

    Kamimura, Sunao; Yamada, Hiroshi; Xu, Chao-Nan

    2013-01-01

    We report photochromism (PC) in Sr2SnO4:Eu3+ with layered perovskite-related structure. The Sr2SnO4:Eu3+ turned purple upon irradiation with UV light (λ < 350 nm), and the colored Sr2SnO4:Eu3+ returned to its initial colorless state when visible light (λ = 400-700 nm) was irradiated. Furthermore, the PC was strongly dependent on the firing temperature; purple color upon UV irradiation can be enhanced by increasing the firing temperature, which was attributed to an increase of the Sr vacancies in the host lattice from the results of crystal structure analysis. This suggests that controlling the lattice defect plays an important role for enhancing the PC performance.

  20. Production of recombinant antibody fragments in Bacillus megaterium

    PubMed Central

    Jordan, Eva; Hust, Michael; Roth, Andreas; Biedendieck, Rebekka; Schirrmann, Thomas; Jahn, Dieter; Dübel, Stefan

    2007-01-01

    Background Recombinant antibodies are essential reagents for research, diagnostics and therapy. The well established production host Escherichia coli relies on the secretion into the periplasmic space for antibody synthesis. Due to the outer membrane of Gram-negative bacteria, only a fraction of this material reaches the medium. Recently, the Gram-positive bacterium Bacillus megaterium was shown to efficiently secrete recombinant proteins into the growth medium. Here we evaluated B. megaterium for the recombinant production of antibody fragments. Results The lysozyme specific single chain Fv (scFv) fragment D1.3 was succesfully produced using B. megaterium. The impact of culture medium composition, gene expression time and culture temperatures on the production of functional scFv protein was systematically analyzed. A production and secretion at 41°C for 24 h using TB medium was optimal for this individual scFv. Interestingly, these parameters were very different to the optimal conditions for the expression of other proteins in B. megaterium. Per L culture supernatant, more than 400 μg of recombinant His6-tagged antibody fragment were purified by one step affinity chromatography. The material produced by B. megaterium showed an increased specific activity compared to material produced in E. coli. Conclusion High yields of functional scFv antibody fragments can be produced and secreted into the culture medium by B. megaterium, making this production system a reasonable alternative to E. coli. PMID:17224052

  1. Cell-free methods to produce structurally intact mammalian membrane proteins.

    PubMed

    Shinoda, Takehiro; Shinya, Naoko; Ito, Kaori; Ishizuka-Katsura, Yoshiko; Ohsawa, Noboru; Terada, Takaho; Hirata, Kunio; Kawano, Yoshiaki; Yamamoto, Masaki; Tomita, Taisuke; Ishibashi, Yohei; Hirabayashi, Yoshio; Kimura-Someya, Tomomi; Shirouzu, Mikako; Yokoyama, Shigeyuki

    2016-01-01

    The crystal structures of four membrane proteins, from bacteria or a unicellular alga, have been solved with samples produced by cell-free protein synthesis. In this study, for mammalian membrane protein production, we established the precipitating and soluble membrane fragment methods: membrane proteins are synthesized with the Escherichia coli cell-free system in the presence of large and small membrane fragments, respectively, and are simultaneously integrated into the lipid environments. We applied the precipitating membrane fragment method to produce various mammalian membrane proteins, including human claudins, glucosylceramide synthase, and the γ-secretase subunits. These proteins were produced at levels of about 0.1-1.0 mg per ml cell-free reaction under the initial conditions, and were obtained as precipitates by ultracentrifugation. Larger amounts of membrane proteins were produced by the soluble membrane fragment method, collected in the ultracentrifugation supernatants, and purified directly by column chromatography. For several proteins, the conditions of the membrane fragment methods were further optimized, such as by the addition of specific lipids/detergents. The functional and structural integrities of the purified proteins were confirmed by analyses of their ligand binding activities, size-exclusion chromatography profiles, and/or thermal stabilities. We successfully obtained high-quality crystals of the complex of human claudin-4 with an enterotoxin. PMID:27465719

  2. Cell-free methods to produce structurally intact mammalian membrane proteins

    PubMed Central

    Shinoda, Takehiro; Shinya, Naoko; Ito, Kaori; Ishizuka-Katsura, Yoshiko; Ohsawa, Noboru; Terada, Takaho; Hirata, Kunio; Kawano, Yoshiaki; Yamamoto, Masaki; Tomita, Taisuke; Ishibashi, Yohei; Hirabayashi, Yoshio; Kimura-Someya, Tomomi; Shirouzu, Mikako; Yokoyama, Shigeyuki

    2016-01-01

    The crystal structures of four membrane proteins, from bacteria or a unicellular alga, have been solved with samples produced by cell-free protein synthesis. In this study, for mammalian membrane protein production, we established the precipitating and soluble membrane fragment methods: membrane proteins are synthesized with the Escherichia coli cell-free system in the presence of large and small membrane fragments, respectively, and are simultaneously integrated into the lipid environments. We applied the precipitating membrane fragment method to produce various mammalian membrane proteins, including human claudins, glucosylceramide synthase, and the γ-secretase subunits. These proteins were produced at levels of about 0.1–1.0 mg per ml cell-free reaction under the initial conditions, and were obtained as precipitates by ultracentrifugation. Larger amounts of membrane proteins were produced by the soluble membrane fragment method, collected in the ultracentrifugation supernatants, and purified directly by column chromatography. For several proteins, the conditions of the membrane fragment methods were further optimized, such as by the addition of specific lipids/detergents. The functional and structural integrities of the purified proteins were confirmed by analyses of their ligand binding activities, size-exclusion chromatography profiles, and/or thermal stabilities. We successfully obtained high-quality crystals of the complex of human claudin-4 with an enterotoxin. PMID:27465719

  3. [Effect of Different Purple Parent Rock on Removal Rates of Nitrogen, Phosphorus and Organics in Landscape Water].

    PubMed

    Huang, Xue-jiao; Liu, Xiao-chen; Li, Zhen-lun; Shi, Wen-hao; Yang, Shan

    2015-05-01

    In order to understand the impacts of physicochemical properties of purple parent rock on the removal rates of nitrogen, phosphorus and organics in landscape water systems, four types of purple parent rocks including Peng-lai-zhen Formation (S1) , Sha-xi-miao Formation (S2) , Fei-xian-guan Formation (S3) and Sui-ning Formation (S4) , which distribute widely in Chongqing, were selected and autoclaved, and added to unsterile landscape water collected from Chong-de Lake in Southwest University, and the landscape water only was used as control. And several indicators such as total nitrogen and phosphorus and so on of every disposal were investigated periodically. The results indicated that: (1) The highest removal rates of total nitrogen, total phosphorus and Ammonia nitrogen were observed in Sl, which were 45.1%, 62.3% and 90%, respectively; the highest removal rate of COD was 94.5% in S4; the ammonia nitrogen content in the purple parent rocks was not obviously changed before and after the experiments, which indicated that the adsorption of ammonia nitrogen on purple parent rock surface was not the main reason for the decrease of ammonia nitrogen in water. (2) Arsenate had inhibitory effect on the sulfate-reducing bacteria, while copper and magnesium had promoting effect on gram-negative bacteria. (3) The microbial diversity was positively correlated to total nitrogen in water. (4) Based on the PCA analyses of microbial community structure and environmental factors, the mineral elements released from parent rock affected the structure and composition of microbial community in the test water, and then influenced the removal rates of nitrogen, phosphorus and organics in water systems. PMID:26314110

  4. Fragments

    ERIC Educational Resources Information Center

    Moreira, Claudio

    2008-01-01

    This performance autoethnography shows the author's struggle in finding his place, scholarship, voice, and body, into the academic setting. Mixing together memories of his lived experience with sugar cane workers, notes, and leftovers of different fieldworks, plus 6 years of life as grad student at the University of Illinois, the author looks for…

  5. Pigment production and isotopic fractionations in continuous culture: okenone producing purple sulfur bacteria Part II.

    PubMed

    Smith, D A; Steele, A; Fogel, M L

    2015-05-01

    Okenone is a carotenoid pigment unique to certain members of Chromatiaceae, the dominant family of purple sulfur bacteria (PSB) found in euxinic photic zones. Diagenetic alteration of okenone produces okenane, the only recognized molecular fossil unique to PSB. The in vivo concentrations of okenone and bacteriochlorophyll a (Bchl a) on a per cell basis were monitored and quantified as a function of light intensity in continuous cultures of the purple sulfur bacterium Marichromatium purpuratum (Mpurp1591). We show that okenone-producing PSB have constant bacteriochlorophyll to carotenoid ratios in light-harvesting antenna complexes. The in vivo concentrations of Bchl a, 0.151 ± 0.012 fmol cell(-1), and okenone, 0.103 ± 0.012 fmol cell(-1), were not dependent on average light intensity (10-225 Lux) at both steady and non-steady states. This observation revealed that in autotrophic continuous cultures of Mpurp1591, there was a constant ratio for okenone to Bchl a of 1:1.5. Okenone was therefore constitutively produced in planktonic cultures of PSB, regardless of light intensity. This confirms the legitimacy of okenone as a signature for autotrophic planktonic PSB and by extrapolation water column euxinia. We measured the δ(13)C, δ(15)N, and δ(34)S bulk biomass values from cells collected daily and determined the isotopic fractionations of Mpurp1591. There was no statistical relationship in the bulk isotope measurements or stable isotope fractionations to light intensity or cell density under steady and non-steady-state conditions. The carbon isotope fractionation between okenone and Bchl a with respect to overall bulk biomass ((13)ε pigment - biomass) was 2.2 ± 0.4‰ and -4.1 ± 0.9‰, respectively. The carbon isotopic fractionation (13ε pigment-CO2) for the production of pigments in PSB is more variable than previously thought with our reported values for okenone at -15.5 ± 1.2‰ and -21.8 ± 1.7‰ for Bchl a. PMID:25857754

  6. Crystallization of Tyrian purple (6,6‧-dibromoindigo) thin films: The impact of substrate surface modifications

    NASA Astrophysics Data System (ADS)

    Truger, Magdalena; Jones, Andrew O. F.; Coclite, Anna Maria; Pachmajer, Stefan; Kriegner, Dominik; Röthel, Christian; Simbrunner, Josef; Salzmann, Ingo; Resel, Roland

    2016-08-01

    The pigment 6,6‧-dibromoindigo (Tyrian purple) shows strong intermolecular hydrogen bonds and the film formation is, therefore, expected to be influenced by the polar character of the substrate surface. Thin films of Tyrian purple were prepared by physical vapor deposition on a variety of substrates with different surface energies: from highly polar silicon dioxide surfaces to hydrophobic polymer surfaces. The crystallographic properties were investigated by X-ray diffraction techniques such as X-ray reflectivity and grazing incidence X-ray diffraction. In all cases, crystallites with "standing" molecules relative to the substrate surface were observed independently of the substrate surface energy. In the case of polymer surfaces, additional crystallites are formed containing "lying" molecules with their aromatic planes parallel to the substrate surface. Small differences in the crystallographic lattice constants were observed as a function of substrate surface energy, the corresponding small changes in the molecular packing are explained by a variation of the hydrogen bond geometries. This work reveals that despite the limited influence of the surface energy on the molecular orientation, the crystalline packing of Tyrian purple within thin films is altered and slightly different structures form.

  7. Rare white-flowered morphs increase the reproductive success of common purple morphs in a food-deceptive orchid.

    PubMed

    Dormont, L; Delle-Vedove, R; Bessière, J-M; Hossaert-Mc Key, M; Schatz, B

    2010-01-01

    How floral colour polymorphism can be maintained in evolutionary time is still debated. In rewardless orchids, it is unknown whether rare white-flowered morphs differ in scent chemistry from pigmented morphs, and whether such intraspecific variation in floral signals may have an impact on reproductive success. We compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of Orchis mascula, and recorded the fruit set of both colour morphs. We also used white ping-pong balls to mimic white-flowered morphs in field bioassays. We found that colour polymorphism was not associated with floral odour polymorphism. Surprisingly, when populations of purple-flowered plants included a few white-flowered individuals, the fruit set of the purple morph increased significantly (from 6 to 27%), while that of the white morph remained low. We obtained the same fourfold increase in fruit set when using ping-pong balls as visual lures, demonstrating the association between colour variation and fruit set, and the key role of visual signals in pollinator attraction. Our results are incompatible with negative frequency-dependent selection, a hypothesis invoked to explain colour polymorphism in other rewardless orchids. We propose several hypotheses to explain the maintenance of white morphs in O. mascula. PMID:19825015

  8. Purple rice bran extract attenuates the aflatoxin B1-induced initiation stage of hepatocarcinogenesis by alteration of xenobiotic metabolizing enzymes.

    PubMed

    Suwannakul, Nattawan; Punvittayagul, Charatda; Jarukamjorn, Kanokwan; Wongpoomchai, Rawiwan

    2015-01-01

    Pigmented rice bran has been suggested to be a valuable source of beneficial phytochemicals. We investigated genotoxic and anti-genotoxic effects of purple rice bran extract (PRBE) in rats using a liver micronucleus assay. Purple rice bran was extracted with methanol, obtaining large amounts of phenolic compounds, including anthocyanins and small amounts of gamma-oryzanol. The experimental protocols were divided into two sets. Male rats were divided into three groups. Group 1 was a negative control, while Groups 2 and 3 were fed with 100 and 500 mg/kg bw of PRBE, respectively, for 28 days. PRBE had no effect on micronucleus formation or xenobiotic metabolizing enzymes in rat liver. Experiments concerning the effect of PRBE on AFB1 showed that PRBE significantly lessened the amount of micronucleated hepatocytes in AFB1 treated rats. Furthermore, it modulated metabolic activation of AFB1 metabolism in the liver by suppressing activity and protein expression of CYP1A2, CYP3A and CYP 450 reductase, and enhancing phase II enzymes including GST and UGT. Overall, purple rice bran extract was not genotoxic in rats. It exhibited anti-genotoxicity by modulation some xenobiotic enzymes active in AFB1 metabolism. PMID:25921147

  9. Improved solar efficiency by introducing graphene oxide in purple cabbage dye sensitized TiO2 based solar cell

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, Ahmed A.; Gupta, R. K.; Kahol, P. K.; Wageh, S.; Al-Turki, Y. A.; El Shirbeeny, W.; Yakuphanoglu, F.

    2014-04-01

    Natural dye extracted from purple cabbage was used for fabrication of TiO2 dye-sensitized solar cells (DSSCs). The effect of light intensity on the solar efficiency of the device was investigated. It was observed that the efficiency of the DSSC increases with increasing the light intensity e.g. the efficiency of the solar cell increases from 0.013±0.002% to 0.150±0.020% by increase in light intensity from 30 to 100 mW/cm2, respectively. The solar efficiency of the natural dye used in this research was compared with commercial dye (N 719) under similar experimental conditions and observed that the natural (purple cabbage) dye has higher efficiency (0.150±0.020%) than N 719 (0.078±0.002%). It was further evaluated that the efficiency of the fabricated solar cell could improve by incorporating graphene oxide. The efficiency of the TiO2 dye-sensitized solar cell was found to increase from 0.150±0.020% to 0.361±0.009% by incorporating graphene oxide into purple cabbage dye.

  10. Membrane magic

    SciTech Connect

    Buecker, B.

    2005-09-01

    The Kansas Power and Light Co.'s La Cyne generating station has found success with membrane filtration water pretreatment technology. The article recounts the process followed in late 2004 to install a Pall Aria 4 microfilter in Unit 1 makeup water system at the plant to produce cleaner water for reverse osmosis feed. 2 figs., 2 photos.

  11. Energy production using fission fragment rockets

    NASA Astrophysics Data System (ADS)

    Chapline, G.; Matsuda, Y.

    1991-08-01

    Fission fragment rockets are nuclear reactors with a core consisting of thin fibers in a vacuum, and which use magnetic fields to extract the fission fragments from the reactor core. As an alternative to ordinary nuclear reactors, fission fragment rockets would have the following advantages: approximately twice the efficiency if the fission fragment energy can be directly converted into electricity; reduction of the buildup of a fission fragment inventory in the reactor could avoid a Chernobyl type disaster; and collection of the fission fragments outside the reactor could simplify the waste disposal problem.

  12. Workflow Design Using Fragment Composition

    NASA Astrophysics Data System (ADS)

    Mosser, Sébastien; Blay-Fornarino, Mireille; France, Robert

    The Service-Oriented Architecture (Soa) paradigm supports the assembly of atomic services to create applications that implement complex business processes. Assembly can be accomplished by service orchestrations defined by Soa architects. The Adore method allows Soa architects to model complex orchestrations of services by composing models of smaller orchestrations called orchestration fragments. The Adore method can also be used to weave fragments that address new concerns into existing application models. In this paper we illustrate how the Adore method can be used to separate and compose process aspects in a Soa design of the Car Crash Crisis Management System. The paper also includes a discussion of the benefits and limitations of the Adore method.

  13. Fragmentation of the Chelyabinsk Fireball

    NASA Astrophysics Data System (ADS)

    Melosh, J.

    2013-12-01

    The most intense bolide since the 1908 Tunguska event occurred in the early morning hours of 15 February 2013 near the Russian town of Chelyabinsk. The impacting asteroid ranged between 17 and 20 m diameter with a mass of about 10,000 tons. Its estimated pre-atmospheric velocity was about 18.6 km/sec at a low angle of 20° from the horizontal. The resulting airburst occurred at an altitude of about 23 km and released an estimated total energy of about 440 kT (1.7 x 1015 J). The blast wave shattered windows on the ground over a wide area and collapsed the roof of a zinc factory. In spite of the size of the initital asteroid, only small fragments (a few kg, so far) have been recovered. The entry of an asteroid into Earth's atmosphere and its aerodynamic fragmentation and deceleration has been modeled by a number of authors over the past few decades. Full-featured numerical simulations are presently limited in their ability to simultaneously incorporate fragmentation, energy coupling between solid fragments and the atmosphere, and thermal radiation, but an approximate treatment of the fragmentation and dispersion of a large entering meteoroid called the 'pancake model' has achieved good fits to other observed events, including the Tunguska explosion, the 1947 Shikote-Alin fall and strewn fields from larger iron meteorite falls, such as the Henbury craters. Simulations using the pancake model can fit the overall observations of the Chelyabinsk event using an 18 m diameter asteroid of density 3000 kg/m3 following the observed trajectory and possessing an initial strength of about 7 MPa, which is relatively high for a stony meteoroid. This suggests that the asteroid was not a strengthless rubble pile, but in fact possessed considerable strength, compared to other stony meteorites of similar type. Aerodynamic breakup begins at an altitude of 31 km and the final airburst occurs at 22 km, releasing about 250 kT at this time. Subsequent to this airburst, large fragments

  14. Asymmetry effects in fragment production

    NASA Astrophysics Data System (ADS)

    Kaur, Manpreet; Kaur, Varinderjit

    2016-05-01

    The production of different fragments has been studied by taking into account the mass asymmetry of the reaction and employing the momentum dependent interactions. Two different set of asymmetric reactions have been analyzed while keeping Atotal fixed using soft momentum dependent equation of state. Our results indicate that the impact of momentum dependent interactions is different in lighter projectile systems as compared to heavier ones. The comparative analysis of IQMD simulations with the experimental data in case of heavier projectile and lighter target system for the reaction of 197Au+27Al (η = 0.7) at E = 600 MeV/nucleon shows that with the inclusion of MDI we are able, upto some extent, to reproduce the experimental universality of rise and fall of intermediate mass fragments (IMFs).

  15. Fragmentation of suddenly heated liquids

    SciTech Connect

    Blink, J.A.

    1985-03-01

    Fragmentation of free liquids in Inertial Confinement Fusion reactors could determine the upper bound on reactor pulse rate. The x-ray ablated materials must cool and recondense to allow driver beam propagation. The increased surface area caused by fragmentation will enhance the cooling and condensation rates. Relaxation from the suddenly heated state will move a liquid into the negative pressure region under the liquid-vapor P-V dome. The lithium equation of state was used to demonstrate that neutron-induced vaporization uses only a minor fraction of the added heat, much less than would be required to drive the expansion. A 77% expansion of the lithium is required before the rapid vaporization process of spinodal decomposition could begin, and nucleation and growth are too slow to contribute to the expansion.

  16. Differential Expression Patterns in Chemosensory and Non-Chemosensory Tissues of Putative Chemosensory Genes Identified by Transcriptome Analysis of Insect Pest the Purple Stem Borer Sesamia inferens (Walker)

    PubMed Central

    Zhang, Ya-Nan; Jin, Jun-Yan; Jin, Rong; Xia, Yi-Han; Zhou, Jing-Jiang; Deng, Jian-Yu; Dong, Shuang-Lin

    2013-01-01

    Background A large number of insect chemosensory genes from different gene subfamilies have been identified and annotated, but their functional diversity and complexity are largely unknown. A systemic examination of expression patterns in chemosensory organs could provide important information. Methodology/Principal Findings We identified 92 putative chemosensory genes by analysing the transcriptome of the antennae and female sex pheromone gland of the purple stem borer Sesamia inferens, among them 87 are novel in this species, including 24 transcripts encoding for odorant binding proteins (OBPs), 24 for chemosensory proteins (CSPs), 2 for sensory neuron membrane proteins (SNMPs), 39 for odorant receptors (ORs) and 3 for ionotropic receptors (IRs). The transcriptome analyses were validated and quantified with a detailed global expression profiling by Reverse Transcription-PCR for all 92 transcripts and by Quantitative Real Time RT-PCR for selected 16 ones. Among the chemosensory gene subfamilies, CSP transcripts are most widely and evenly expressed in different tissues and stages, OBP transcripts showed a clear antenna bias and most of OR transcripts are only detected in adult antennae. Our results also revealed that some OR transcripts, such as the transcripts of SNMP2 and 2 IRs were expressed in non-chemosensory tissues, and some CSP transcripts were antenna-biased expression. Furthermore, no chemosensory transcript is specific to female sex pheromone gland and very few are found in the heads. Conclusion Our study revealed that there are a large number of chemosensory genes expressed in S. inferens, and some of them displayed unusual expression profile in non-chemosensory tissues. The identification of a large set of putative chemosensory genes of each subfamily from a single insect species, together with their different expression profiles provide further information in understanding the functions of these chemosensory genes in S. inferens as well as other

  17. Calcium ions are required for the enhanced thermal stability of the light-harvesting-reaction center core complex from thermophilic purple sulfur bacterium Thermochromatium tepidum.

    PubMed

    Kimura, Yukihiro; Yu, Long-Jiang; Hirano, Yu; Suzuki, Hiroaki; Wang, Zheng-Yu

    2009-01-01

    Thermochromatium tepidum is a thermophilic purple sulfur photosynthetic bacterium collected from the Mammoth Hot Springs, Yellowstone National Park. A previous study showed that the light-harvesting-reaction center core complex (LH1-RC) purified from this bacterium is highly stable at room temperature (Suzuki, H., Hirano, Y., Kimura, Y., Takaichi, S., Kobayashi, M., Miki, K., and Wang, Z.-Y. (2007) Biochim. Biophys. Acta 1767, 1057-1063). In this work, we demonstrate that thermal stability of the Tch. tepidum LH1-RC is much higher than that of its mesophilic counterparts, and the enhanced thermal stability requires Ca2+ as a cofactor. Removal of the Ca2+ from Tch. tepidum LH1-RC resulted in a complex with the same degree of thermal stability as that of the LH1-RCs purified from mesophilic bacteria. The enhanced thermal stability can be restored by addition of Ca2+ to the Ca2+-depleted LH1-RC, and this process is fully reversible. Interchange of the thermal stability between the two forms is accompanied by a shift of the LH1 Qy transition between 915 nm for the native and 880 nm for the Ca2+-depleted LH1-RC. Differential scanning calorimetry measurements reveal that degradation temperature of the native LH1-RC is 15 degrees C higher and the enthalpy change is about 28% larger than the Ca2+-depleted LH1-RC. Substitution of the Ca2+ with other metal cations caused a decrease in thermal stability of an extent depending on the properties of the cations. These results indicate that Ca2+ ions play a dual role in stabilizing the structure of the pigment-membrane protein complex and in altering its spectroscopic properties, and hence provide insight into the adaptive strategy of this photosynthetic organism to survive in extreme environments using natural resources. PMID:18977753

  18. The fragmentation of Kosmos 2163

    NASA Technical Reports Server (NTRS)

    1992-01-01

    On 6 Dec. 1991 Kosmos 2163, a maneuverable Soviet spacecraft which had been in orbit for 58 days, experienced a major breakup at an altitude of approximately 210 km. Although numerous pieces of debris were created, the fragments decayed rapidly leaving no long-term impact on the near-Earth environment. The assessed cause of the event is the deliberate detonation of an explosive device. Details of this event are presented.

  19. Telomere Restriction Fragment (TRF) Analysis

    PubMed Central

    Mender, Ilgen; Shay, Jerry W.

    2016-01-01

    While telomerase is expressed in ~90% of primary human tumors, most somatic tissue cells except transiently proliferating stem-like cells do not have detectable telomerase activity (Shay and Wright, 1996; Shay and Wright, 2001). Telomeres progressively shorten with each cell division in normal cells, including proliferating stem-like cells, due to the end replication (lagging strand synthesis) problem and other causes such as oxidative damage, therefore all somatic cells have limited cell proliferation capacity (Hayflick limit) (Hayflick and Moorhead, 1961; Olovnikov, 1973). The progressive telomere shortening eventually leads to growth arrest in normal cells, which is known as replicative senescence (Shay et al., 1991). Once telomerase is activated in cancer cells, telomere length is stabilized by the addition of TTAGGG repeats to the end of chromosomes, thus enabling the limitless continuation of cell division (Shay and Wright, 1996; Shay and Wright, 2001). Therefore, the link between aging and cancer can be partially explained by telomere biology. There are many rapid and convenient methods to study telomere biology such as Telomere Restriction Fragment (TRF), Telomere Repeat Amplification Protocol (TRAP) (Mender and Shay, 2015b) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this protocol paper we describe Telomere Restriction Fragment (TRF) analysis to determine average telomeric length of cells. Telomeric length can be indirectly measured by a technique called Telomere Restriction Fragment analysis (TRF). This technique is a modified Southern blot, which measures the heterogeneous range of telomere lengths in a cell population using the length distribution of the terminal restriction fragments (Harley et al., 1990; Ouellette et al., 2000). This method can be used in eukaryotic cells. The description below focuses on the measurement of human cancer cells telomere length. The principle of this method relies on the lack of

  20. Modeling of Fragmentation of Asteroids

    NASA Technical Reports Server (NTRS)

    Agrawal, Parul; Prabhu, Dinesh K.; Carlozzi, Alexander; Hart, Kenneth; Bryson, Katie; Sears, Derek

    2015-01-01

    The objective of this study is to understand fragmentation and fracture of a given asteroid and mechanisms of break-up. The focus of the present work is to develop modeling techniques for stony asteroids in 10m-100m range to answer two questions: 1) What is the role of material makeup of an asteroid in the stress distribution? 2)How is stress distribution altered in the presence of pre-existing defects?

  1. HCD Fragmentation of Glycated Peptides.

    PubMed

    Keilhauer, Eva C; Geyer, Philipp E; Mann, Matthias

    2016-08-01

    Protein glycation is a concentration-dependent nonenzymatic reaction of reducing sugars with amine groups of proteins to form early as well as advanced glycation (end-) products (AGEs). Glycation is a highly disease-relevant modification but is typically only studied on a few blood proteins. To complement our blood proteomics studies in diabetics, we here investigate protein glycation by higher energy collisional dissociation (HCD) fragmentation on Orbitrap mass spectrometers. We established parameters to most efficiently fragment and identify early glycation products on in vitro glycated model proteins. Retaining standard collision energies does not degrade performance if the most dominant neutral loss of H6O3 is included into the database search strategy. Glycation analysis of the entire HeLa proteome revealed an unexpected intracellular preponderance for arginine over lysine modification in early and advanced glycation (end-) products. Single-run analysis from 1 μL of undepleted and unenriched blood plasma identified 101 early glycation sites as well as numerous AGE sites on diverse plasma proteins. We conclude that HCD fragmentation is well-suited for analyzing glycated peptides and that the diabetic status of patients can be directly diagnosed from single-run plasma proteomics measurements. PMID:27425404

  2. Fractionalization beyond Luttinger Liquid in the spectroscopy of Lithium Purple Bronze

    NASA Astrophysics Data System (ADS)

    Natalia, Lera; Jose, Alvarez

    We offer an interpretation for the departures of ARPES and STS spectroscopies experiments in quasi-one-dimensional Lithium Purple Bronze (LiPB) from single-band Luttinger Liquid (LL) theory. We base our calculation on a phenomenological description of the published data proposed in the original experiments and consider two bands crossing the Fermi level. We discuss the breakdown of the LL scaling relation η = α - 1 , the separation of the spinon edge and the holon peak, the phenomenological TL fit to the Energy Distribution Curves (EDC) and the survival of power-like density of states down to 4K. We consider non-critical fluctuations in one of the separated modes in which the electron fractionalize, and discuss under which conditions could be related with the upturn in the resistivity at 20-30K. We discuss the possibility of a gap in such separated mode and its role on the robust one-dimensional behavior. The connection with the proposed triplet superconductivity is at T = 1 . 4 K is also studied. We acknowledge financial support from MINECO FIS2012-37549-C05-03.

  3. Antimutagenic and antioxidant properties of phenolic fractions from Andean purple corn (Zea mays L.).

    PubMed

    Pedreschi, Romina; Cisneros-Zevallos, Luis

    2006-06-28

    The antimutagenic and antioxidant properties of various phenolic fractions obtained from Andean purple corn were examined by the Ames test and the DPPH antiradical assay. An anthocyanin-rich water fraction (WF) and an ethyl acetate fraction (EAF) showed a dose-dependent antimutagenic behavior against the food mutagen Trp-P-1 with IC50 values of 321.7 +/- 21.36 and 95.2 +/- 10.95 microg of chlorogenic acid equiv/plate, respectively, indicating that EAF was a more potent antimutagen. The antioxidant activities for WF and EAF were 1.019 +/- 0.05 and 0.838 +/- 0.11 microg of Trolox equiv/mug of phenolics, respectively. Further fractionation of WF and EAF revealed an ethyl acetate subfraction, EA-IV, with high antimutagen potency that contained a quercetin derivative. The mechanism of antimutagenic action of the WF is predominantly a blocking effect on the S-9 Mix activation system of the mutagen, whereas for the EAF, it is a dual mechanism involving blocking of the S-9 Mix and a scavenging action on Trp-P-1 electrophiles. PMID:16786998

  4. Role of Anthocyanin-enriched Purple-fleshed Sweet Potato P40 in Colorectal Cancer Prevention

    PubMed Central

    Lim, Soyoung; Xu, Jianteng; Kim, Jaeyong; Chen, Tzu-Yu; Su, Xiaoyu; Standard, Joseph; Carey, Edward; Griffin, Jason; Herndon, Betty; Katz, Benjamin; Tomich, John; Wang, Weiqun

    2013-01-01

    Scope Anthocyanins, the natural pigments in plant foods, have been associated with cancer prevention. However, the content of anthocyanins in staple foods is typically low and the mechanisms by which they exert anti-cancer activity is not yet fully defined. Methods and results We selected an anthocyanin-enriched purple-fleshed sweet potato clone, P40, and investigated its potential anti-cancer effect in both in vitro cell culture and in vivo animal model. In addition to a high level of total phenolics and antioxidant capacity, P40 possesses a high content of anthocyanins at 7.5 mg/g dry matter. Treatment of human colonic SW480 cancer cells with P40 anthocyanin extracts at 0–40 μM of peonidin-3-glucoside equivalent resulted in a dose-dependent decrease in cell number due to cytostatic arrest of cell cycle at G1 phase but not cytotoxicity. Furthermore, dietary P40 at 10–30% significantly suppressed azoxymethane-induced formation of aberrant crypt foci in the colons of CF-1 mice in conjunction with, at least in part, a lesser proliferative PCNA and a greater apoptotic caspase-3 expression in the colon mucosal epithelial cells. Conclusion These observations, coupled with both in vitro and in vivo studies reported here, suggest anthocyanin-enriched sweet potato P40 may protect against colorectal cancer by inducing cell cycle arrest, anti-proliferative and apoptotic mechanisms. PMID:23784800

  5. Pre-heating and polyphenol oxidase inhibition impact on extraction of purple sweet potato anthocyanins.

    PubMed

    de Aguiar Cipriano, Paula; Ekici, Lutfiye; Barnes, Ryan C; Gomes, Carmen; Talcott, Stephen T

    2015-08-01

    Purple sweet potatoes (PSP) have been used as a natural food colorant with high acylated anthocyanins concentrations. Commercially extracting pigments from PSP can be challenging due to firm texture and high polyphenol oxidase (PPO) content. These studies evaluated hot water immersions (30, 50, 70, and 90°C for 10 min) as pre-heating treatments and addition of PPO inhibitors (citric acid, oxalic acid, and sodium borate) to aqueous extraction solutions to aid pigment recovery. Predominant PSP anthocyanins included acylated cyanidin or peonidin derivatives. Non-pigmented cinnamates acted as oxidase substrates and induced co-oxidation reactions with anthocyanins. Pre-heating PSP significantly increased polyphenolic yields in a temperature-dependent manner, consistent with tissue softening and PPO inactivation. The use of solvent modifiers in the extraction solution associated with heat helped minimize enzyme action and increased polyphenolic recovery. Minimizing the impact of PPO with heat was critical to the extraction and recovery of PSP anthocyanins, suitable for food use. PMID:25766822

  6. Band structure of the quasi two-dimensional purple molybdenum bronze

    NASA Astrophysics Data System (ADS)

    Guyot, H.; Balaska, H.; Perrier, P.; Marcus, J.

    2006-09-01

    The molybdenum purple bronze KMo 6O 17 is quasi two-dimensional (2D) metallic oxide that shows a Peierls transition towards a metallic charge density wave state. Since this specific transition is directly related to the electron properties of the normal state, we have investigated the electronic structure of this bronze at room temperature. The shape of the Mo K1s absorption edge reveals the presence of distorted MoO 6 octahedra in the crystallographic structure. Photoemission experiments evidence a large conduction band, with a bandwidth of 800 meV and confirm the metallic character of this bronze. A wide depleted zone separates the conduction band from the valence band that exhibits a fourfold structure, directly connected to the octahedral symmetry of the Mo sites. The band structure is determined by ARUPS in two main directions of the (0 0 1) Brillouin zone. It exhibits some unpredicted features but corroborates the earlier theoretical band structure and Fermi surface. It confirms the hidden one-dimensionality of KMo 6O 17 that has been proposed to explain the origin of the Peierls transition in this 2D compound.

  7. An Approach to More Accurate Model Systems for Purple Acid Phosphatases (PAPs).

    PubMed

    Bernhardt, Paul V; Bosch, Simone; Comba, Peter; Gahan, Lawrence R; Hanson, Graeme R; Mereacre, Valeriu; Noble, Christopher J; Powell, Annie K; Schenk, Gerhard; Wadepohl, Hubert

    2015-08-01

    The active site of mammalian purple acid phosphatases (PAPs) have a dinuclear iron site in two accessible oxidation states (Fe(III)2 and Fe(III)Fe(II)), and the heterovalent is the active form, involved in the regulation of phosphate and phosphorylated metabolite levels in a wide range of organisms. Therefore, two sites with different coordination geometries to stabilize the heterovalent active form and, in addition, with hydrogen bond donors to enable the fixation of the substrate and release of the product, are believed to be required for catalytically competent model systems. Two ligands and their dinuclear iron complexes have been studied in detail. The solid-state structures and properties, studied by X-ray crystallography, magnetism, and Mössbauer spectroscopy, and the solution structural and electronic properties, investigated by mass spectrometry, electronic, nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and Mössbauer spectroscopies and electrochemistry, are discussed in detail in order to understand the structures and relative stabilities in solution. In particular, with one of the ligands, a heterovalent Fe(III)Fe(II) species has been produced by chemical oxidation of the Fe(II)2 precursor. The phosphatase reactivities of the complexes, in particular, also of the heterovalent complex, are reported. These studies include pH-dependent as well as substrate concentration dependent studies, leading to pH profiles, catalytic efficiencies and turnover numbers, and indicate that the heterovalent diiron complex discussed here is an accurate PAP model system. PMID:26196255

  8. Biochemical characterization of the purple form of Marinobacter hydrocarbonoclasticus nitrous oxide reductase

    PubMed Central

    Dell'Acqua, Simone; Pauleta, Sofia R.; Moura, José J. G.; Moura, Isabel

    2012-01-01

    Nitrous oxide reductase (N2OR) catalyses the final step of the denitrification pathway—the reduction of nitrous oxide to nitrogen. The catalytic centre (CuZ) is a unique tetranuclear copper centre bridged by inorganic sulphur in a tetrahedron arrangement that can have different oxidation states. Previously, Marinobacter hydrocarbonoclasticus N2OR was isolated with the CuZ centre as CuZ*, in the [1Cu2+ : 3Cu+] redox state, which is redox inert and requires prolonged incubation under reductive conditions to be activated. In this work, we report, for the first time, the isolation of N2OR from M. hydrocarbonoclasticus in the ‘purple’ form, in which the CuZ centre is in the oxidized [2Cu2+ : 2Cu+] redox state and is redox active. This form of the enzyme was isolated in the presence of oxygen from a microaerobic culture in the presence of nitrate and also from a strictly anaerobic culture. The purple form of the enzyme was biochemically characterized and was shown to be a redox active species, although it is still catalytically non-competent, as its specific activity is lower than that of the activated fully reduced enzyme and comparable with that of the enzyme with the CuZ centre in either the [1Cu2+ : 3Cu+] redox state or in the redox inactive CuZ* state. PMID:22451106

  9. Comparative theoretical studies of the phosphomonoester hydrolysis mechanism by purple acid phosphatases.

    PubMed

    Retegan, M; Milet, A; Jamet, H

    2010-07-01

    We present here the first ONIOM (our own n-layered integrated molecular orbital + molecular mechanics method) studies of a purple acid phosphatase enzyme. Our study focused on the structures of the red kidney bean PAP (kbPAP) complexed with phosphate and with phenyl phosphate and on the mechanism of the phenyl phosphate hydrolysis by the enzyme. Density functional theory (DFT) calculations were also performed using models of different sizes for comparison purpose. Results show that the inclusion of three histidine residues, His202, His295, and His296, with their protein surrounding, is crucial to properly describe the coordination of the substrates. They induce a conformation with the substrate closer to the nucleophilic mu-hydroxyde bridge. In the mechanistic study, a transition state is stabilized by a strong hydrogen bond between His202 and the leaving group of the substrate. Consequently, a smaller value for the activation energy barrier is obtained from DFT calculations including this histidine to the same calculations without this histidine. Using the ONIOM method, this activation energy barrier is even more reduced. So the mechanism, which considers the hydroxo group bridging the two metal ions as nucleophile, becomes really convincing, contrary to the results obtained with a small model at the DFT level. PMID:20550096

  10. Competition for sulfide among colorless and purple sulfur bacteria in cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    Jorgensen, B. B.; Des Marais, D. J.

    1986-01-01

    The vertical zonation of light, O2, H2S, pH, and sulfur bacteria was studied in two benthic cyanobacterial mats from hypersaline ponds at Guerrero Negro, Baja California, Mexico. The physical-chemical gradients were analyzed in the upper few mm at < or = 100 micrometers spatial resolution by microelectrodes and by a fiber optic microprobe. In mats, where oxygen produced by photosynthesis diffused far below the depth of the photic zone, colorless sulfur bacteria (Beggiatoa sp.) were the dominant sulfide oxidizing organisms. In a mat, where the O2-H2S interface was close to the photic zone, but yet received no significant visible light, purple sulfur bacteria (Chromatium sp.) were the dominant sulfide oxidizers. Analysis of the spectral light distribution here showed that the penetration of only 1% of the incident near-IR light (800-900 nm) into the sulfide zone was sufficient for the mass development of Chromatium in a narrow band of 300 micromoles thickness. The balance between O2 and light penetration down into the sulfide zone thus determined in micro-scale which type of sulfur bacteria became dominant.

  11. Hydrolysis of phosphodiesters by diiron complexes: design of nonequivalent iron sites in purple acid phosphatase models.

    PubMed

    Verge, François; Lebrun, Colette; Fontecave, Marc; Ménage, Stéphane

    2003-01-27

    New mu-oxo-diferric complexes have been designed for hydrolysis of phosphodiesters. To mimic the diiron active site of purple acid phosphatase, a combinatorial method has been used to select complexes containing two distinct iron coordination spheres. The introduction of a bidentate ligand, a substituted phenanthroline (L) into complex 1, [Fe2O(bipy)4(OH2)2](NO3)4, generates in solution the complex [Fe2O(bipy)3(L)(OH2)2](NO3)4 as shown by ESI/MS and 1H NMR studies. The latter complex was found to be 20-fold more active than complex 1. On the basis of kinetic studies, we demonstrated that the complex [Fe2O(bipy)3(L)(OH)(OH2)](NO3)3 was the active species and the reaction proceeded through the formation of a ternary complex in which one iron binds a hydroxide and the second, the substrate. At nonsaturating concentrations of the substrate, the increased activity with increased methyl substituents in L was due to an increased affinity of the complex for the substrate. The activity of [Fe2O(bipy)3(33'44'Me2-Phen)(OH2)2](NO3)4 [33'44'Me2Phen = 3,3',4,4'-dimethyl-1,10-phenanthroline] was found to be comparable to that reported for Co(III) or Ce(IV) complexes. PMID:12693232

  12. Characterisation of the LH2 spectral variants produced by the photosynthetic purple sulphur bacterium Allochromatium vinosum.

    PubMed

    Carey, Anne-Marie; Hacking, Kirsty; Picken, Nichola; Honkanen, Suvi; Kelly, Sharon; Niedzwiedzki, Dariusz M; Blankenship, Robert E; Shimizu, Yuuki; Wang-Otomo, Zheng-Yu; Cogdell, Richard J

    2014-11-01

    This study systematically investigated the different types of LH2 produced by Allochromatium (Alc.) vinosum, a photosynthetic purple sulphur bacterium, in response to variations in growth conditions. Three different spectral forms of LH2 were isolated and purified, the B800-820, B800-840 and B800-850 LH2 types, all of which exhibit an unusual split 800 peak in their low temperature absorption spectra. However, it is likely that more forms are also present. Relatively more B800-820 and B800-840 are produced under low light conditions, while relatively more B800-850 is produced under high light conditions. Polypeptide compositions of the three different LH2 types were determined by a combination of HPLC and TOF/MS. The B800-820, B800-840 and B800-850 LH2 types all have a heterogeneous polypeptide composition, containing multiple types of both α and β polypeptides, and differ in their precise polypeptide composition. They all have a mixed carotenoid composition, containing carotenoids of the spirilloxanthin series. In all cases the most abundant carotenoid is rhodopin; however, there is a shift towards carotenoids with a higher conjugation number in LH2 complexes produced under low light conditions. CD spectroscopy, together with the polypeptide analysis, demonstrates that these Alc. vinosum LH2 complexes are more closely related to the LH2 complex from Phs. molischianum than they are to the LH2 complexes from Rps. acidophila. PMID:25111749

  13. Energy transfer in spectrally inhomogeneous light-harvesting pigment-protein complexes of purple bacteria.

    PubMed Central

    Hess, S; Akesson, E; Cogdell, R J; Pullerits, T; Sundström, V

    1995-01-01

    Energy transfer within the peripheral light-harvesting antenna of the purple bacteria Rhodobacter sphaeroides and Rhodopseudomonas palustris was studied by one- and two-color pump-probe absorption spectroscopy with approximately 100-fs tunable pulses at room temperature and at 77 K. The energy transfer from B800 to B850 occurs with a time constant of 0.7 +/- 0.05 ps at room temperature and 1.8 +/- 0.2 ps at 77 K and is similar in both species. Anisotropy measurements suggest a limited but fast B800 <--> B800 transfer time (tau approximately 0.3 ps). This is analyzed as incoherent hopping of the excitation in a system of spectrally inhomogeneous antenna pigment-protein complexes, by a master equation approach. The simulations show that the measured B800 dynamics is well described as energy transfer with a characteristic average nearest-neighbor pairwise transfer time of 0.35 ps among approximately 10 Bchl molecules in a circular arrangement, in good agreement with the recent high-resolution structure of LH2. The possible presence of fast intramolecular relaxation processes within the Bchl a molecule was investigated by measurement of time-resolved difference absorption spectra and kinetics of Bchl a in solution and in low-temperature glasses. From these measurements it is concluded that fast transients observed at room temperature are due mainly to solvation processes, whereas at 77 K predominantly slower (> 10-ps) relaxation occurs. Images FIGURE 11 PMID:8599629

  14. Molecular phylogeny of four homeobox genes from the purple sea star Pisaster ochraceus.

    PubMed

    Matassi, Giorgio; Imai, Janice Hitomi; Di Gregorio, Anna

    2015-11-01

    Homeobox genes cloned from the purple sea star Pisaster ochraceus (Phylum Echinodermata/Class Asteroidea) were used along with related sequences available from members of other representative animal phyla to generate molecular phylogenies for Distal-less/Dlx, Hox5, Hox7, and Hox9/10 homeobox genes. Phylogenetic relationships were inferred based on the predicted 60 amino acid homeodomain, using amino acid (AA) and nucleotide (NT) models as well as the recently developed codon substitution models of sequence evolution. The resulting phylogenetic trees were mostly congruent with the consensus species-tree, grouping these newly identified genes with those isolated from other Asteroidea. This analysis also allowed a preliminary comparison of the performance of codon models with that of NT and AA evolutionary models in the inference of homeobox phylogeny. We found that, overall, the NT models displayed low reliability in recovering major clades at the Superphylum/Phylum level, and that codon models were slightly more dependable than AA models. Remarkably, in the majority of cases, codon substitution models seemed to outperform both AA and NT models at both the Class level and homeobox paralogy-group level of classification. PMID:26432455

  15. Viscoelastic characteristics and phytochemical properties of purple-rice drinks following ultrahigh pressure and pasteurization

    NASA Astrophysics Data System (ADS)

    Worametrachanon, Srivilai; Apichartsrangkoon, Arunee

    2014-10-01

    This study investigated how pressure (500, 600 MPa/20 min) altered the viscoelastic characteristics and phytochemical properties of germinated and non-germinated purple-rice drinks in comparison with pasteurization. Accordingly, color parameters, storage and loss moduli, anthocyanin content, γ-oryzanol, γ-aminobutyric acid (GABA), total phenolic compounds and 2,2-diphenyl-1-picrylthydrazyl (DPPH) capacity of the processed drinks were determined. The finding showed that germinated and pressurized rice drink had lower Browning Index than the non-germinated and pasteurized rice drink. The plots of storage and loss moduli for processed rice drinks indicated that time of pressurization had greater impact on gel structural modification than the level of pressure used. The phytochemicals, including total phenolics, and DPPH capacity in pressurized rice drinks retained higher quantity than those in pasteurized drink, despite less treatment effects on anthocyanin. On the contrary, both γ-oryzanol and GABA were found in high amounts in germinated rice drink with little variation among processing effects.

  16. Biochemical Characterization and Subcellular Localization of the Red Kidney Bean Purple Acid Phosphatase.

    PubMed Central

    Cashikar, A. G.; Kumaresan, R.; Rao, N. M.

    1997-01-01

    Phosphatases are known to play a crucial role in phosphate turnover in plants. However, the exact role of acid phosphatases in plants has been elusive because of insufficient knowledge of their in vivo substrate and subcellular localization. We investigated the biochemical properties of a purple acid phosphatase isolated from red kidney bean (Phaseolus vulgaris) (KBPAP) with respect to its substrate and inhibitor profiles. The kinetic parameters were estimated for five substrates. We used 31P nuclear magnetic resonance to investigate the in vivo substrate of KBPAP. Chemical and enzymological estimation of polyphosphates and ATP, respectively, indicated the absence of polyphosphates and the presence of ATP in trace amounts in the seed extracts. Immunolocalization using antibodies raised against KBPAP was unsuccessful because of the non-specificity of the antiserum toward glycoproteins. Using histoenzymological methods with ATP as a substrate, we could localize KBPAP exclusively in the cell walls of the peripheral two to three rows of cells in the cotyledons. KBPAP activity was not detected in the embryo. In vitro experiments indicated that pectin, a major component of the cell wall, significantly altered the kinetic properties of KBPAP. The substrate profile and localization suggest that KBPAP may have a role in mobilizing organic phosphates in the soil during germination. PMID:12223752

  17. In Vitro and in Vivo antioxidant activity of ethyl acetate extraction of purple rice.

    PubMed

    Shen, Y; Chen, L; Zhang, H; Zhang, Y; Zhang, H; Wang, L; Qian, H; Qi, X; Zhang, H

    2016-01-01

    The antioxidant activities of ethyl acetate extraction of purple rice (EAEPR) were evaluated by various methods in vitro and in vivo. In in vitro antioxidant assays, EAEPR was found to have strong 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity hydroxyl radical, reducing power and metal-ion chelating activity. In in vivo antioxidant assays, mice were administered with EAEPR via gavage for 42 consecutive days. As a result, administration of EAEPR significantly enhanced the activities of glutathione peroxidase in serums and livers of mice. EAEPR could improve the lipid status, especially total cholesterol and low-density lipoprotein cholesterol levels. In addition, total phenolic content of EAEPR was 188.21mg/g. The main phenolic compounds in EAEPR analyzed by ultra-high performance liquid chromatography tandem mass spectrometry were determined as ferulic acid and quercetin. The contents of ferulic acid and quercetin in EAEPR were 14.21mg/g and 35.28mg/g, respectively. The Nrf2 expression was significantly elevated after administration of EAEPR.These results suggested that EAEPR had potent antioxidant activity and could be explored as a novel natural antioxidant. PMID:27188742

  18. Domestic cooking methods affect the phytochemical composition and antioxidant activity of purple-fleshed potatoes.

    PubMed

    Tian, Jinhu; Chen, Jianle; Lv, Feiyan; Chen, Shiguo; Chen, Jianchu; Liu, Donghong; Ye, Xingqian

    2016-04-15

    The effects of domestic cooking methods (boiling, baking, steaming, microwaving, frying, and stir-frying) and a new cooking method (air-frying) on the composition of phytochemicals (phenolics, anthocyanins, and carotenoids) and the antioxidant activity in purple-fleshed potatoes were investigated. Compared with raw potatoes, reductions of 23.59-90.42%, 7.09-72.44%, 7.45-83.15%, and 20.15-76.16% in the vitamin C, total phenolic, anthocyanin and carotenoid contents, respectively, was observed after cooking. Decreases of 7.88%, 21.55%, 22.48, 6.31%, and 61.38% in DPPH radical-scavenging activity was also observed after boiling, steaming, baking, microwaving and stir-frying, respectively, whereas an increase of 30.52% was noted after air-frying. A correlation analysis revealed that the antioxidant activity was in accordance with the total phenolic content and that this activity showed the lowest correlation with the vitamin C content. Among all of the cooking methods investigated in this study, stir-frying retained only slight levels of the phytochemicals and antioxidant activity observed in raw potatoes, whereas steaming and microwaving were able to retain most of the health-promoting compounds found in raw potatoes and may thus be suitable methods for cooking potatoes. PMID:26675866

  19. Biotransformation of anthocyanins from two purple-fleshed sweet potato accessions in a dynamic gastrointestinal system.

    PubMed

    Kubow, Stan; Iskandar, Michèle M; Sabally, Kebba; Azadi, Behnam; Sadeghi Ekbatan, Shima; Kumarathasan, Premkumari; Das, Dharani Dhar; Prakash, Satya; Burgos, Gabriela; Zum Felde, Thomas

    2016-02-01

    Cooked, milled purple-fleshed sweet potato (PFSP) accessions, PM09.812 and PM09.960, underwent digestion in a dynamic human gastrointestinal (GI) model that simulates gut digestive conditions to study the bioaccessibility and biotransformation of anthocyanins. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed accession-dependent variations in anthocyanin release and degradation. After 24h, more anthocyanin species were detected in the small intestinal vessel relative to other vessels for accession PM09.960 whereas more species appeared in the ascending colonic vessel for accession PM09.812. The ferric reducing antioxidant power was increased in the small intestinal vessel for PM09.960 and in the ascending colonic vessel for accession PM09.812, corresponding to the appearance of a majority of anthocyanins for each accession. These results show that intestinal and colonic microbial digestion of PFSP leads to an accession-dependent pattern for anthocyanin bioaccessibility and degradation. PMID:26304335

  20. Density-functional studies of purple bronze: A paradigm Tomonaga-Luttinger liquid

    NASA Astrophysics Data System (ADS)

    Popovic, Zoran; Satpathy, Sashi

    2003-03-01

    Using density-functional band structure calculations, we examine the electronic structure of the purple bronze Li_0.9Mo_6O_17, which exhibits a quasi-one-dimensional Tomonaga-Luttinger liquid behavior. Most of the physical properties are governed by the peculiar double zigzag chains found in the crystal structure of this compound. Our calculations show that the most relevant states around the Fermi level (E_f), are formed from the 4d t_2g orbitals belonging to Mo atoms that are positioned on the zigzag chains. The overall shape and dispersion width of the bands around Ef are consistent with recent ARPES tearpes measurements. We determine the Fermi surface to consist of two slightly warped planes perpendicular to the direction of the zigzag chains. The calculated nesting vector is in very good agreement with the ARPES tearpes data. * Work supported by the U. S. Department of Energy. 00 [*]bymitPermanent address: Institute for Nuclear Sciences-``Vinča'', PO Box: 522, 11001 Belgrade, Yugoslavia arpes G.-H. Gweon, et al., J. of Elect. Spect. and Related Phenomena, 117-118, 481 (2001) thebibliography

  1. Diversification of innate immune genes: lessons from the purple sea urchin.

    PubMed

    Smith, L Courtney

    2010-01-01

    Pathogen diversification can alter infection virulence, which in turn drives the evolution of host immune diversification, resulting in countermeasures for survival in this arms race. Somatic recombination of the immunoglobulin gene family members is a very effective mechanism to diversify antibodies and T-cell receptors that function in the adaptive immune system. Although mechanisms to diversify innate immune genes are not clearly understood, a seemingly unlikely source for insight into innate immune diversification may be derived from the purple sea urchin, which has recently had its genome sequenced and annotated. Although there are many differences, some characteristics of the sea urchin make for a useful tool to understand the human immune system. The sea urchin is phylogenetically related to humans although, as a group, sea urchins are evolutionarily much older than mammals. Humans require both adaptive and innate immune responses to survive immune challenges, whereas sea urchins only require innate immune functions. Genes that function in immunity tend to be members of families, and the sea urchin has several innate immune gene families. One of these is the Sp185/333 gene family with about 50 clustered members that encode a diverse array of putative immune response proteins. Understanding gene diversification in the Sp185/333 family in the sea urchin may illuminate new mechanisms of diversification that could apply to gene families that function in innate immunity in humans, such as the killer immunoglobulin-like receptor genes. PMID:20354110

  2. Amplified protein sensing using deep purple fluorophores on homogeneous Au substrates.

    PubMed

    Xie, Fang; Goldys, Ewa; Baker, Mark

    2007-01-01

    We report here the first observation of appreciable enhancement of fluorescence induced by large Au colloids. Au monolayers with Au colloids of 40 nm, 59 nm, and 81 nm in radii, were formed on silane modified glass surfaces, respectively. The nanoparticle densities were varied by varying the deposition times and documented by scanning electron microscopy. Two types of samples were prepared, with large inter-particle distance and hence little or no inter-particle coupling and small inter-particle distance with inter-particle coupling. The fluorescence enhancement was examined by using a self assembled monolayer of the fluorophore-protein conjugate with Deep Purple as a fluorophore and Bovine Serum Albumin as protein (DP-BSA). The data show the over 15 fold enhancement under optimized conditions and reveal strong variations with both inter-particle distance and particle size. Nanostructures of appropriate size with optimized inter-particle distance thus prepared can produce promising substrates for decent fluorescence enhancement. We demonstrated that the Au colloid monolayers on glass surfaces are promising substrates for fluorescence enhancement with outstanding macroscopic homogeneity. This important feature will pave the way for the application of our substrates in biotechnology and life sciences such as imaging and sensing of biomolecules in proteomics. PMID:18607074

  3. Ophthalmic indications of amniotic membrane transplantation in Mexico: an eight years Amniotic Membrane Bank experience.

    PubMed

    Chávez-García, César; Jiménez-Corona, Aída; Graue-Hernández, Enrique O; Zaga-Clavellina, Verónica; García-Mejía, Mariana; Jiménez-Martínez, María Carmen; Garfias, Yonathan

    2016-06-01

    Amniotic membrane, the inner layer of the placenta, has biological properties (e.g. promotes epithelization, reduces fibrosis, secretes antimicrobial products and inhibits immune responses) which make it a useful option for several ophthalmologic procedures, especially those involving the ocular surface. Its use in eye surgery has been reported by other authors. To our knowledge, there is a lack of descriptive studies on surgical indications using amniotic membrane in Mexican population. Here we describe the eight years Amniotic Membrane Bank experience in Mexico, including a detailed protocol of the donors selection, tissue harvesting, preparation, storage and distribution of amniotic membrane since its establishment in 2007. Moreover, we describe the Ophthalmological indications of amniotic membrane transplantation of the total of 1686 amniotic membranes fragments used during eight years. The five most common indications for amniotic membrane transplantation were pterygium (46 %), corneal ulcers (12.6 %), conjunctival surface repair (11.1 %), neoplasms (7.4 %), and persistent epithelial defects (7.3 %). In addition, we compared the indications of amniotic membrane use in two different types of Institutions: general hospitals and ophthalmologic reference hospitals. We found interesting differences between the indications and use rates between these institutions, although pterygium was the most frequent pathology that amniotic membrane fragments were used in both institutions, there was up to a five-fold increase in the use of amniotic membrane for correction of persistent epithelial defects in reference hospitals which could be explained due to the more complex and severe ophthalmological pathologies admitted in reference hospitals. In conclusion, Amniotic Membrane is used in a numerous ocular pathologies and especially on pterygium in our Mexican population. PMID:26675894

  4. Characterization of the major cyanogen bromide fragment of alpha-A crystallin

    NASA Technical Reports Server (NTRS)

    Ifeanyi, F.; Takemoto, L.; Spooner, B. S. (Principal Investigator)

    1991-01-01

    Alpha crystallin from the bovine lens has been digested with cyanogen bromide, and the major fragment (CB-1) has been purified using reverse phase HPLC. Characterization of this fragment by Edman degradation and antisera to synthetic peptides indicates that it originates from alpha-A crystallin, but lacks the N-terminal methionine and the last 35 amino acids from the C-terminus of the molecule. The purified CB-1 fragment binds as well as native alpha crystallin to lens membrane, but is unable to self-assemble into the correct size of high molecular weight oligomeric complexes characteristic of the intact alpha-A chain. Together, these results demonstrate that the alpha-A chain is comprised of at least two functional domains, one of which is involved in binding of alpha-A crystallin to lens membrane, and another which is necessary for correct self-assembly of the molecule into high molecular weight oligomers.

  5. Fragmentation of cosmic-string loops

    NASA Technical Reports Server (NTRS)

    York, Thomas

    1989-01-01

    The fragmentation of cosmic string loops is discussed, and the results of a simulation of this process are presented. The simulation can evolve any of a large class of loops essentially exactly, including allowing fragments that collide to join together. Such reconnection enhances the production of small fragments, but not drastically. With or without reconnections, the fragmentation process produces a collection of nonself-intersecting loops whose typical length is on the order of the persistence length of the initial loop.

  6. Comparison of calculations of fragment production

    SciTech Connect

    Canavan, G.H.

    1998-01-01

    This note compares estimates of fragment production rates in debris collisions through calculations performed with consistent debris distribution functions implicit in integrated collision frequencies provided by Attachment A. Differences between estimates of fragment production rates in space debris collisions are shown to be due primarily to different choices of the exponent in the fragment production function and the distinction between catastrophic and all collisions. Sensitivity to the fragment production parameter over the range of values consistent with experimental data is discussed.

  7. Bimodal Behavior of the Heaviest Fragment Distribution in Projectile Fragmentation

    SciTech Connect

    Bonnet, E.; Borderie, B.; Rivet, M. F.; Dayras, R.; Gagnon-Moisan, F.; Guinet, D.; Lautesse, P.; Parlog, M.; Rosato, E.; Vigilante, M.

    2009-08-14

    The charge distribution of the heaviest fragment detected in the decay of quasiprojectiles produced in intermediate energy heavy-ion collisions has been observed to be bimodal. This feature is expected as a generic signal of phase transition in nonextensive systems. In this Letter, we present new analyses of experimental data from Au on Au collisions at 60, 80, and 100 MeV/nucleon showing that bimodality is largely independent of the data selection procedure and of entrance channel effects. An estimate of the latent heat of the transition is extracted.

  8. UNUSUAL PHENOLIC COMPOUNDS CONTRIBUTE TO ECOPHYSIOLOGICAL PERFORMANCE IN THE PURPLE-COLORED GREEN ALGA ZYGOGONIUM ERICETORUM (ZYGNEMATOPHYCEAE, STREPTOPHYTA) FROM A HIGH-ALPINE HABITAT

    PubMed Central

    Aigner, Siegfried; Remias, Daniel; Karsten, Ulf; Holzinger, Andreas

    2013-01-01

    The filamentous green alga Zygogonium ericetorum (Zygnematophyceae, Streptophyta) was collected in a high-alpine rivulet in Tyrol, Austria. Two different morphotypes of this alga were found: a purple morph with a visible purple vacuolar content and a green morph lacking this coloration. These morphotypes were compared with respect to their secondary metabolites, ultrastructure, and ecophysiological properties. Colorimetric tests with aqueous extracts of the purple morph indicated the presence of soluble compounds such as phenolics and hydrolyzable tannins. High-performance liquid chromatography-screening showed that Z. ericetorum contained several large phenolic peaks with absorption maxima at ∼280 nm and sometimes with minor maxima at ∼380 nm. Such compounds are uncommon for freshwater green microalgae, and could contribute to protect the organism against increased UV and visible (VIS) irradiation. The purple Z. ericetorum contained larger amounts (per dry weight) of the putative phenolic substances than the green morph; exposure to irradiation may be a key factor for accumulation of these phenolic compounds. Transmission electron microscopy of the purple morph showed massive vacuolization with homogenous medium electron-dense content in the cell periphery, which possibly contains the secondary compounds. In contrast, the green morph had smaller, electron-translucent vacuoles. The ecophysiological data on photosynthesis and desiccation tolerance indicated that increasing photon fluence densities led to much higher relative electron transport rates (rETR) in the purple than in the green morph. These data suggest that the secondary metabolites in the purple morph are important for light acclimation in high-alpine habitats. However, the green morph recovered better after 4 d of rehydration following desiccation stress. PMID:25810559

  9. Unusual phenolic compounds contribute to ecophysiological performance in the purple-colored green alga zygogonium ericetorum (zygnematophyceae, streptophyta) from a high-alpine habitat.

    PubMed

    Aigner, Siegfried; Remias, Daniel; Karsten, Ulf; Holzinger, Andreas

    2013-08-01

    The filamentous green alga Zygogonium ericetorum (Zygnematophyceae, Streptophyta) was collected in a high-alpine rivulet in Tyrol, Austria. Two different morphotypes of this alga were found: a purple morph with a visible purple vacuolar content and a green morph lacking this coloration. These morphotypes were compared with respect to their secondary metabolites, ultrastructure, and ecophysiological properties. Colorimetric tests with aqueous extracts of the purple morph indicated the presence of soluble compounds such as phenolics and hydrolyzable tannins. High-performance liquid chromatography-screening showed that Z. ericetorum contained several large phenolic peaks with absorption maxima at ∼280 nm and sometimes with minor maxima at ∼380 nm. Such compounds are uncommon for freshwater green microalgae, and could contribute to protect the organism against increased UV and visible (VIS) irradiation. The purple Z. ericetorum contained larger amounts (per dry weight) of the putative phenolic substances than the green morph; exposure to irradiation may be a key factor for accumulation of these phenolic compounds. Transmission electron microscopy of the purple morph showed massive vacuolization with homogenous medium electron-dense content in the cell periphery, which possibly contains the secondary compounds. In contrast, the green morph had smaller, electron-translucent vacuoles. The ecophysiological data on photosynthesis and desiccation tolerance indicated that increasing photon fluence densities led to much higher relative electron transport rates (rETR) in the purple than in the green morph. These data suggest that the secondary metabolites in the purple morph are important for light acclimation in high-alpine habitats. However, the green morph recovered better after 4 d of rehydration following desiccation stress. PMID:25810559

  10. Spectral, electron microscopic and chemical investigations of gamma-induced purple color zonings in amethyst crystals from the Dursunbey-Balıkesir region of Turkey

    NASA Astrophysics Data System (ADS)

    Hatipoğlu, Murat; Kibar, Rana; Çetin, Ahmet; Can, Nurdoğan; Helvacı, Cahit; Derin, H.

    2011-07-01

    Amethyst crystals on matrix specimens from the Dursunbey-Balıkesir region in Turkey have five representative purple color zonings: dark purple, light purple, lilac, orchid, and violet. The purple color zonings have been analyzed with optical absorption spectra in the visible wavelength region, chemical full trace element analyses (inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectroscopy), and scanning electron microscopic images with high magnification. It can be proposed that the production of the purple color in amethyst crystals is due to three dominant absorption bands centered at 375, 530, and 675 nm, respectively. In addition, the purple color zonings are also due to four minor absorption bands centered at 435, 480, 620, and 760 nm. X-ray diffraction graphics of the investigated amethyst crystals indicate that these crystals are composed of a nearly pure alpha-quartz phase and do not include any moganite silica phase and/or other mineral implications. Trace element analyses of the amethyst crystals show five representative purple color zonings, suggesting that the absorption bands can be mainly attributed to extrinsic defects (chemical impurities). However, another important factor that influences all structural defects in amethyst is likely to be the gamma irradiation that exists during amethyst crystallization and its inclusion in host materials. This gamma irradiation originates from the large underlying intrusive granitoid body in the region of amethyst formation. Irradiation modifies the valence values of the impurity elements in the amethyst crystals. It is observed that the violet-colored amethyst crystals have the most stable and the least reversible coloration when exposed to strong light sources. This situation can be related to the higher impurity content of Fe (2.50 ppm), Co (3.1 ppm), Ni (38 ppm), Cu (17.9 ppm), Zn (10 ppm), Zr (3.9 ppm), and Mo (21.8 ppm).

  11. [Membranous nephropathy].

    PubMed

    Mercadal, Lucile

    2013-12-01

    Membranous nephropathy is characterized by immune complex deposits on the outer side of the glomerular basement membrane. Activation of complement and of oxidation lead to basement membrane lesions. The most frequent form is idiopathic. At 5 and 10 years, renal survival is around 90 and 65% respectively. A prognostic model based on proteinuria, level and duration, progression of renal failure in a few months can refine prognosis. The urinary excretion of C5b-9, β2 and α1 microglobuline and IgG are strong predictors of outcome. Symptomatic treatment is based on anticoagulation in case of nephrotic syndrome, angiotensin conversion enzyme inhibitors, angiotensin II receptor blockers and statins. Immunosuppressive therapy should be discussed for patients having a high risk of progression. Corticoids alone has no indication. Treatment should include a simultaneous association or more often alternating corticoids and alkylant agent for a minimum of 6 months. Adrenocorticoid stimulating hormone and steroids plus mycophenolate mofetil may be equally effective. Steroids plus alkylant decrease the risk of end stage renal failure. Cyclosporine and tacrolimus decrease proteinuria but are associated with a high risk of recurrence at time of withdrawal and are nephrotoxic. Rituximab evaluated on open studies needs further evaluations to define its use. PMID:24315535

  12. Fractal avalanche ruptures in biological membranes

    NASA Astrophysics Data System (ADS)

    Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

    2010-11-01

    Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

  13. Multipass Membrane Protein Structure Prediction Using Rosetta

    PubMed Central

    Yarov-Yarovoy, Vladimir; Schonbrun, Jack; Baker, David

    2006-01-01

    We describe the adaptation of the Rosetta de novo structure prediction method for prediction of helical transmembrane protein structures. The membrane environment is modeled by embedding the protein chain into a model membrane represented by parallel planes defining hydrophobic, interface, and polar membrane layers for each energy evaluation. The optimal embedding is determined by maximizing the exposure of surface hydrophobic residues within the membrane and minimizing hydrophobic exposure outside of the membrane. Protein conformations are built up using the Rosetta fragment assembly method and evaluated using a new membrane-specific version of the Rosetta low-resolution energy function in which residue–residue and residue–environment interactions are functions of the membrane layer in addition to amino acid identity, distance, and density. We find that lower energy and more native-like structures are achieved by sequential addition of helices to a growing chain, which may mimic some aspects of helical protein biogenesis after translocation, rather than folding the whole chain simultaneously as in the Rosetta soluble protein prediction method. In tests on 12 membrane proteins for which the structure is known, between 51 and 145 residues were predicted with root-mean-square deviation <4Å from the native structure. PMID:16372357

  14. Fragmentation methods in laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; Whitehurst, Colin; King, Terence A.

    1991-07-01

    Following a series of opto-acoustic-mechanical and spectroscopic studies into the basic mechanisms of laser lithotripsy, a plasma-mediated opto-mechanical energy transfer model is presented. Laser energy, first absorbed by the calculi material at the surface and couples into the initiated plasma following ionization of vaporized material, is finally transformed into destructive mechanical energy via a shock wave induced by the impulsive expansion of the resulting plasma. This leads to the fragmentation of the calculi. The laser-plasma energy coupling gives a new definition for the fluence threshold to laser induced breakdown, which agrees with shock wave detection and analysis. A laser pulse shape with initial low intensity and sufficient fluence to vaporize a required amount of target material (lasting a few microsecond(s) ) and terminating in a short, intense pulse of about 1microsecond(s) or less, to couple most of the laser energy into the dense young plasma and so create high pressures, is required to produce optimum effect for laser lithotripsy. An opto-mechanical coupler has been designed which transfers the maximum laser energy into mechanically destructive energy, and successfully fragments various types of urinary and biliary calculi even including those calculi with poor surface absorptance, like pure white cystine. A solid state laser, Ho:YAG (2.1 micrometers wavelength and 150 microsecond(s) pulse width), has also been tested as an alternative to the flashlamp-excited dye laser. The underwater shock wave induced by this laser has been measured and has successfully fragmented calculi with poor absorptance in the visible region.

  15. Fission fragment excited laser system

    DOEpatents

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  16. The fragmentation process at HERMES

    SciTech Connect

    Maiheu, B.

    2005-10-06

    In semi-inclusive deep-inelastic scattering one can study the fragmentation process of partons by extracting multiplicity distributions for the resulting hadrons. At the HERMES experiment a unique possibility exists to study this hadronization at a {radical}(s) of 7.2 GeV. Making full use of the hadron identification capabilities of a Ring Imaging Cerenkov (RICH) detector, we were able to extract charge-separated pion and kaon multiplicities. Significant effort was put reducing the model dependence of the result by tuning the used MC generator and using an unfolding method to correct for experimental inefficiencies and migration of events due to both radiative and detector smearing.

  17. An 1O2 Route to γ-Hydroxyalkenal Phospholipids by Vitamin E Induced Fragmentation of Hydroperoxydiene-derived Endoperoxides

    PubMed Central

    Gu, Xiaodong; Zhang, Wujuan; Choi, Jaewoo; Li, Wei; Chen, Xi; Laird, James M.; Salomon, Robert G.

    2011-01-01

    Biologically active phospholipids that incorporate an oxidatively truncated acyl chain terminated by a γ-hydroxyalkenal are generated in vivo. The γ-hydroxyalkenal moiety protrudes from lipid bilayers like whiskers that serve as ligands for the scavenger receptor CD36, fostering endocytosis, e.g., of oxidatively damaged photoreceptor cell outer segments by retinal pigmented endothelial cells. They also covalently modify proteins generating carboxyalkyl pyrroles incorporating the ε-amino group of protein lysyl residues. We postulated that γ-hydroxyalkenals could be generated, e.g., in the eye, through fragmentation of hydroperoxy endoperoxides produced in the retina through reactions of singlet molecular oxygen with polyunsaturated phospholipids. Since phospholipid esters are far more abundant in the retina than free fatty acids, we examined the influence of a membrane environment on the fate of hydroperoxy endoperoxides. We now report that linoleate hydroperoxy endoperoxides in thin films and their phospholipid esters in bio-mimetic membranes fragment to γ-hydroxyalkenals, and fragmentation is stoichiometrically induced by vitamin E. The product distribution from fragmentation of the free acid in the homogeneous environment of a thin film is remarkably different than that from the corresponding phospholipid in a membrane. In the membrane, further oxidation of the initially formed γ-hydroxyalkenal to a butenolide is disfavored. A conformational preference for the γ-hydroxyalkenal, to protrude from the membrane into the aqueous phase, may protect it from oxidation induced by lipid hydroperoxides that remain buried in the lipophilic membrane core. PMID:21568309

  18. Screening of condensed tannins from Canadian prairie forages for anti-Escherichia coli O157:H7 with an emphasis on purple prairie clover (Dalea purpurea Vent).

    PubMed

    Wang, Y; Jin, L; Ominski, K H; He, M; Xu, Z; Krause, D O; Acharya, S N; Wittenberg, K M; Liu, X L; Stanford, K; McAllister, T A

    2013-04-01

    Tannins from forages grown (n = 10) on the Canadian prairie, as well as from Quebracho, Rhus semialata, and brown seaweed (Ascophyllum nodosum), were screened for anti-Escherichia coli O157:H7 activity against E. coli O157:H7 strain 3081 at a concentration of 400 μg/ml for each tannin type, except for brown seaweed, which was at 50 μg/ml. Growth of the bacteria was assessed by measuring the optical density at 600 nm over 24 h. Tannin from seaweed at a concentration of 50 μg/ml inhibited growth of strain 3081. Among the terrestrial forages, only condensed tannins (CT) from purple prairie clover (Dalea purpurea Vent; PPC) increased (P < 0.05) the lag time and reduced (P < 0.05) the growth rate of E. coli O157:H7. The anti-E. coli O157:H7 activity of PPC CT was further assessed by culturing E. coli strain ATCC 25922 and eight strains of E. coli O157:H7 with PPC CT at 0, 25, 50, 100, or 200 μg/ml. Selected strains were enumerated after 0, 6, and 24 h of incubation, and fatty acid composition was determined after 24 h of incubation. E. coli strain 25922 was cultured with 0, 50, or 200 μg of CT per ml and harvested during the exponential growth phase for examination by transmission electron microscopy. Increasing CT concentration linearly increased (P < 0.001) the lag times of seven strains and linearly reduced (P < 0.001) the growth rates of eight E. coli O157:H7 strains. Proportions of unsaturated fatty acids in the total fatty acids were decreased (P < 0.01) by CT at 50 μg/ml. Transmission electron microscopy showed that CT disrupted the outer membrane structure. Anti-E. coli O157:H7 activity of PPC CT at levels of up to 200 μg/ml was bacteriostatic rather than bactericidal, and the mechanism of anti-E. coli activity may involve alteration in the fatty acid composition and disruption of the outer membrane of the cell. PMID:23575115

  19. Ternary fission of nuclei into comparable fragments

    SciTech Connect

    Karpeshin, F. F.

    2015-07-15

    The problem of nuclear fission into three comparable fragments is considered. A mechanism of true ternary fission is proposed. In contrast to sequential fission, where the three fragments arise upon two sequential events of binary fission, the mechanism in question relies on a scenario that originally involves fission into three fragments. This mechanism is driven by a hexadecapole deformation of the fissioning nucleus, in contrast to binary fission associated with quadrupole vibrations of the nuclear surface. The fragment-mass ratios are estimated. The dynamics of formation of collinear fragments and their subsequent motion in opposite directions is traced. The calculated probability of true ternary fission complies with observed values.

  20. Velocity distribution of fragments of catastrophic impacts

    NASA Technical Reports Server (NTRS)

    Takagi, Yasuhiko; Kato, Manabu; Mizutani, Hitoshi

    1992-01-01

    Three dimensional velocities of fragments produced by laboratory impact experiments were measured for basalts and pyrophyllites. The velocity distribution of fragments obtained shows that the velocity range of the major fragments is rather narrow, at most within a factor of 3 and that no clear dependence of velocity on the fragment mass is observed. The NonDimensional Impact Stress (NDIS) defined by Mizutani et al. (1990) is found to be an appropriate scaling parameter to describe the overall fragment velocity as well as the antipodal velocity.