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  • 1
    Electronic Resource
    Electronic Resource
    FT-IR and near-infrared FT-Raman study of aggregation of bacteriochlorophyll c in solutions: evidence for involvement of the ester group in the aggregation (1995)
    s.l. : American Chemical Society
    Biochemistry 34 (1995), S. 7854-7860 
    Details
    ISSN: 1520-4995
    Source: ACS Legacy Archives
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/bi00024a009
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  • 2
    Electronic Resource
    Electronic Resource
    Evaluation of the Resistance of Euglena gracilis to Ion Beam Radiation (2004)
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 51 (2004), S. 0 
    Details
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . The resistance of Euglena (E.) gracilis to ionizing radiation was investigated using seven kinds of ion beams each with different energy characteristics. The minimum effective dose of the most lethal ion beams was 40 Gy. Given its substantially high resistance to heavy ion beams, E. gracilis possesses great potential in acting as an effective support system to produce food and regenerate oxygen in a space station. The lethal effect of ionizing radiation was dependent on the linear energy transfer value of the heavy ion beams, and reached a maximum at 196 keV/μm. This value was different from those obtained by previous irradiation experiments using mammalian and plant cells, suggesting that the radiation response of E. gracilis is distinct from that of mammalian and plant cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1550-7408.2004.tb00573.x
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  • 3
    Electronic Resource
    Electronic Resource
    The formation and characterization of the in vitro polymeric aggregates of bacteriochlorophyllc homologs fromChlorobium limicola in aqueous suspension in the presence of monogalactosyl diglyceride (1994)
    Springer
    Photosynthesis research 41 (1994), S. 235-243 
    Details
    ISSN: 1573-5079
    Keywords: bacteriochlorophyll ; chlorosomeChlorobium limicola ; green bacteria ; photosynthesis ; monogalactosyl diglyceride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Artificial aggregates of bacteriochlorophyllc (BChlc) were formed in an aqueous medium in the presence of a lipid, monogalactosyl diglyceride (MGDG), and the optical properties of those aggregates were studied by absorption and circular dichroism (CD) mainly. Four BChlc homologs, ([E,E]BChlc F, [P,E]BChlc F, [E,M]BChlc F and [I,E]BChlc F), were isolated from the green photosynthetic bacteriumChlorobium limicola strain 6230. Above 0.0004%, MGDG induced a red-shift of the absorption maxima of BChlc aggregates. At 0.003% MGDG BChlc aggregates showed absorption maxima in the range of 724 to 745 (±3) nm with a shift of 12 to 24 (±3) nm depending on the homolog species. Four kinds of BChlc-MGDG aggregates showed characteristic CD spectra. [E,M]BChlc F gave rise to a CD spectrum similar to that of chlorosomes, while the other three gave spectra of opposite sign. These aggregates are sensitive to 1-hexanol treatment; in a saturating amount (0.85%) of 1-hexanol, all the homologs gave a monomer-like absorption spectrum peaking at 670nm. At an intermediate concentration (0.5%), [E,M]BChlc F showed an enhanced CD intensity, as observed in native chlorosomes. Resonance Raman spectra of the monomer-like BChlc samples indicated that the keto vibrational band at ca. 1640 cm−1 was considerably weakened by the 0.85% 1-hexanol treatment, however the 1680 cm−1 band characteristic of a free keto group did not appear. These results indicate that the artificial aggregates formed by purified BChlc homologs and MGDG are good models for studying chlorosomes structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02184164
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  • 4
    Electronic Resource
    Electronic Resource
    Aggregation of bacteriochlorophyll c homologs to dimers, tetramers, and polymers in water-saturated carbon tetrachloride (1992)
    Springer
    Photosynthesis research 33 (1992), S. 251-257 
    Details
    ISSN: 1573-5079
    Keywords: bacteriochlorophyll c ; Chlorobium limicola ; chlorosome ; circular dichroism ; green photosynthetic bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Three homologs of BChl c, 2-(R)-(1-hydroxyethyl)-4-n-propyl-5-ethyl-farnesyl BChl c (PEF-BChl c), 2-(R)-(1-hydroxyethyl)-4-ethyl-5-ethyl-farnesyl BChl c (EEF-BChl c), and 2-(S)-(1-hydroxyethyl)-4-isobutyl-5-methyl/ethyl-farnesyl BChl c (iBM/EF-BChl c), formed aggregates in water-saturated carbon tetrachloride (H2O-satd CCl4). The water content was about 100 times higher than that of the dried CCl4 previously used. Absorption spectra were recorded for 8 concentrations for the three homologs of BChl c and were deconvoluted in terms of standard spectra of monomer, dimer, tetramer and polymer (747-nm aggregate, Olson and Pedersen (1990) Photosynthe Res 25: 25). PEF- and EEF-BChl c formed dimers (680 nm maximum) and tetramers (705–710 nm maximum), but iBM/EF-BChl c formed polymers. Inhibition of dimer formation by water faciliated the study of the initial stages of the polymerization of BChl c. When the logarithm of polymer concentration was plotted versus the logarithm of the monomer concentration for iBM/EF-BChl c, the initial slope was 30±10 and indicated the cooperation of 20–40 BChl c molecules to form a polymer from a seed. Circular dichroism spectra of the polymers with positive and negative bands at 743 and 760 nm, respectively, were similar to those for chlorosomes (Brune et al. (1990) Photosynth Res 24: 253).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00030035
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  • 5
    Electronic Resource
    Electronic Resource
    How the formation process influences the structure of BChl c aggregates (1999)
    Springer
    Photosynthesis research 60 (1999), S. 229-239 
    Details
    ISSN: 1573-5079
    Keywords: BChl c-stacking size ; chlorosomes ; high aggregates ; ordering of BChl c molecules ; time variation of absorption spectra ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The change of absorption spectra has been measured during the drying process of (31 R)bacteriochlorophyll (BChl) c from diethyl ether, dichloromethane (CH2Cl2) and carbon tetrachloride (CCl4) solutions. Absorption maxima of the Qy(0–0) transition of BChl c appear at 659 nm in diethyl ether, 680 nm in CH2Cl2 and 710 nm in CCl4. All these peaks are red-shifted to about 740 nm with formation of solid high aggregates when the solutions are completely dried. Fourier transform infrared spectra of the three solid aggregates are almost identical. However, magnetic circular dichroism and circular dichroism spectra are different and can be explained in terms of variations in stacking size of the aggregates and molecular arrangement of BChl c. Small-angle X-ray diffraction has been observed only for the aggregates treated with CH2Cl2, and the same sample gave rise to highly resolved cross polarization/magic angle spinning 13C nuclear magnetic resonance spectrum. The results suggest that molecular ordering of the solid-state BChl c aggregates is highly dependent on the formation process which is largely determined by the solvent used.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006258029191
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  • 6
    Electronic Resource
    Electronic Resource
    Syntheses of squarylium-substituted alanine and its peptide, and formation of their thin films onto a poly(3-methylthiophene)/Au electrode (1998)
    New York : Wiley-Blackwell
    Biopolymers 47 (1998), S. 179-183 
    Details
    ISSN: 0006-3525
    Keywords: non-natural amino acid ; peptide ; squarylium dye ; thin film ; poly(3-methylthiophene) ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We designed a polypeptide that behaves as a photodevice by using a non-natural amino acid with replacement of an α-hydrogen by a squarylium dye and succeeded in syntheses of the non-natural amino acid derivative containing a squarylium and its peptide with trialanine Ala-Ala-Ala. Strong dye-dye interactions were confirmed by absorption and CD spectra for the peptide in 2,2,2-trifluoroethanol solution and in water suspension. The non-natural amino acid derivative could be deposited onto a PMeT/Au electrode by the micelle disruption method. © 1998 John Wiley & Sons, Inc. Biopoly 47: 179-183, 1998
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Photovoltaic effect based on wet poly(vinyl alcohol)/merocyanine dye junction (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 35 (1988), S. 1759-1767 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The sandwich cell, Au/wet poly(vinyl alcohol) (PVA)/merocyanine (MD)/Au, based on the PVA/MD junction exhibited photovoltaic and rectifying effects. Forward dark current from the MD/Au electrode to the counter PVA/Au electrode through the cell was observed. The Au/MD electrode showed a positive photovoltage with respect to the PVA/Au electrode regardless of the direction of the incident light. It was suggested that a heterojunction barrier similar to the Schottky type formed at polymer/dye interface was responsible for the photo charge separation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070350704
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  • 8
    Electronic Resource
    Electronic Resource
    Fabrication and optoelectrical properties of polypyrrole-rhodamine B two-layer organic photovoltaic cell (1988)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 26 (1988), S. 95-98 
    Details
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1988.140260206
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  • 9
    Electronic Resource
    Electronic Resource
    Undoping effect of electropolymerized polymer for two-layer organic photovoltaic ceils based on polymer/dye junction (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 48 (1993), S. 2207-2212 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The undoping effects of electropolymerized poly(3-methylthiophene) (PMeT) and poly(N-methylpyrrole) (PMPy) on the open-circuit photovoltage Voc and on short-circuit pho-tocurrent Jsc were investigated for two-layer organic photovoltaic cells based on the PMeT or PMPy / vacuumevaporated rhodamine B (RB) under the electrochemical doping level between -3 and +3 V. The value of Voc of the undoped-polymer / RB cell was larger than that of the doped-polymer / RB cell. PMeT/RB and PMPy/RB cells gave the minimum value of Jsc at a doping level of 0 V. It was suggested that polarons and bipolarons states formed at a doping level of 0 V may work as a trap site for the carrier to decrease in Jsc. Undoping of the PMeT improved Voc and Jsc of the PMeT/RB two-layer organic pho-tovoltaic cell together with its durability. © 1993 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070481214
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  • 10
    Electronic Resource
    Electronic Resource
    Polymerizations of chloral, styrene oxide, and methyl methacrylate initiated by the binary system of bis(acetylacetonato)metal(II) and chloral (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 707-717 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The binary system of bis(acetylacetonato)metal(II) [M(acac)2] and chloral induced the polymerization of chloral [M = Mn(II), Co(II), Mg(II), and Cu(II)], the ring-opening polymerization of styrene oxide [M = Co(II) and Mg(II)], and the radical polymerization of methyl methacrylate [M = Mn(II) and Co(II)]. The similar order of activity of M(acac)2 as the catalyst for the polymerization of chloral and for the aldol reaction of chloral with acetylacetone, the deactivation of the catalyst by the introduction of a substituent at the 3-position of M(acac)2, the presence of saturated β-diketone at the end of the polymer of chloral and that of styrene oxide, and the visible light spectral data supporting the formation of the β-ketoalcoholate intermediate in the binary system of Co(acac)2 and chloral are all experimental findings which suggest that M(acac)2 is subject to the aldol addition by chloral at the 3-position of the chelated acetylacetone and that the resultant β-ketoalcoholate is a common active species for these polymerizations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170150317
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