Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Analytical Chemistry and Spectroscopy  (2)
  • Aleurone  (1)
  • Atomic, Molecular and Optical Physics  (1)
  • Endosperm  (1)
  • 1
    ISSN: 1432-2048
    Keywords: Aleurone ; Endosperm ; Triticum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Early cellularization of the free-nuclear endosperm and subsequent differentation of the aleurone cells in the ventral region of the developing wheatgrain (Triticumaestivum L. cv. Heron) were examined using both light and electron microscopy. In ovules harvested 1 d after anthesis, irregular wall ingroths typical of transfer cells protrude into the multinucleate cytoplasm. Initital cellularization occurs by a process of free wall formation in much the same fashion as in the dorsal region of the grain. In places, sheets of endoplasmic reticulum and dictyosomes appear to be closely associated with the growing wall. Like the wall ingrowths noted earlier, the freely growing walls are intensely fluorescent after staining with aniline blue. Initiatal cellularization is complete 2–3 days after anthesis. Unlike the first-formed cells in the dorsal region of the developing grain, those in the ventral region are not meristematic. These amitotic cells become the groove aleurone cells which at an early stage of development are set apart from the rest of the endosperm by their irregularly thickened walls and dense cytoplasm. Autofluorescence is first apparent in the walls of those cells next to the degenerating nucellus. In contrast to the aleurone cells in the dorsal region of the grain, at maturity only the inner wall layer of each of the groove aleurone cells remains autofluorescent. The aleurone grains are highly variable in appearance and contain no Type II inclusions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 1 (1967), S. 161-167 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On étudie les informations relatives aux indices de réfraction pour quelques gaz pour obtenir des formules analytiques. De celles-ci on obtient le coéfficient du terme principal de l'interaction de longue portée entre deux corps ainsi que celui de l'interaction de longue portée non-additive entre trois corps. On calcule les coéfficients correspondants pour des mélanges des gases He, Ne, A, Kr, Ze, H2, N2 et CH4, l'erreur probable étant 5%.
    Abstract: Gewisse Brechungsindexinformationen für mehrere Gase sind zu analytischen Formeln angepasst. Von diesen berechnet man die Koeffiziente des Prinzipalglieds der Wechselwirkung zwei entfernter Körper und der non-additiven Wechselwirkung drei entfernter Körper. Koeffizienten sind für Mischungen der Gase He, Ne, A, Kr, Xe, H2, N2 und CH4 berechnet, mit einem wahrscheinlichen Fehler von 5%.
    Notes: The refractive index data for various gases are fitted to analytical formulae from which may be calculated the coefficient of the leading term of the long-range two-body interactions and the coefficient of the leading term of the long-range non-additive three-body interactions. Coefficients are obtained for mixtures of the gases He, Ne, A, Kr, Xe, H2, N2 and CH4, the probable error being 5%.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 23 (1994), S. 71-74 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Using gas chromatography/mass spectrometry we have observed six peaks in the single ion chromatograph at m/z 674 of the alkaline extract of barley straw cell walls. The breakdown pattern of these ions suggests that they could all be isomers of 5,5′-bis-dehydroferulic acid. Since only the 5,5′ linkage is reported to be present in plants this tentatively suggests that these compounds exhibit stable orientational isomerism about this bond. Plausible breakdown mechanisms are presented which allow for the complete assignment of structure to all the isomers. These mechanisms suggest that the two pairs of breakdown ions at m/z 556 and 467, and 265 and 193 are representative of trans and cis double bonds, respectively.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 6 (1992), S. 46-53 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Substituted cinnamic acids were dimerized, under fluorescent or UV light, as a glassy coating on a vial then subsequently analysed by GC/MS. Mass Spectrometric analysis of the dimers formed by each acid allowed the assignment of the dimer as a truxillic or truxinic structure since these structures had distinctive fragmentation patterns; the breakdown of the truxillic acids involves a McLafferty rearrangment before fragmentation occurs, whereas the truxinic acids, which have both carboxy groups on one side and both aromatic groups on the other, fragment asymmetrically to give characteristic stilbene and dicarboxylate fragments. It is apparent from the results of the dimerization of the lcinnamic acids that, under the conditions used here, if the monomeric acid had the capacity for hydrogen bonding using the ring substituent as well as the carboxy group, the dimerization products would be overshelmingly truxillic in structure. However, if only the carboxy group could hydrogen bond, the products would be almost exclusively traxinic in structure.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...