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  • 1
    Electronic Resource
    Electronic Resource
    The absolute value of the quantum yield of the fluorescence of the 1B3u 0–0 state of pyrazine as a function of the rotational quantum numbers (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 4004-4010 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In this paper we fit low-resolution spectra of pyrazine by assuming Coriolis coupling between S1 and {S0}. Evidence for Coriolis coupling is particularly obvious in the rovibronic spectra of pyrazine-d3h1 of which we give high resolution examples. For the lowest rotational temperature we noticed a non-Boltzmann distribution of the J‘=0 ground state, which is probably caused by a bottleneck for ΔJ‘=−2 transitions. Using the lifetimes of molecular eigenstates belonging to P(1) we can calculate the absolute quantum yield of the vibrationless and rotationless 1B3u state. Using this number and the obtained interstate Coriolis coupling rate constants we calculate the variation of the absolute quantum yield across the rotational contour. For low J we get satisfactory agreement with experiments, but for high J our calculations drop off too fast with J. We explain this by the fact that at high J values triplet decay becomes dominant because of K scrambling in the triplet manifold.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.451909
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  • 2
    Electronic Resource
    Electronic Resource
    The fast component in the decay of pyrazine (1986)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 538-539 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.450125
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  • 3
    Electronic Resource
    Electronic Resource
    Yield of exoelectrons from cluster bombardment of metallic surfaces (1988)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 92 (1988), S. 5749-5754 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100331a040
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  • 4
    Electronic Resource
    Electronic Resource
    Radiationless transitions and the quantum yield for nonresonant light scattering (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 588-597 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The quantum yield for fluorescence can be defined as the ratio of the amount of light scattered as fluorescence or as Rayleigh or Raman scattering to the amount of light removed from an incident beam. Clearly then the quantum yield should go to one for a nonresonant excitation. The conventional theory of radiationless transitons (the Bixon–Jortner model) does not yield this result. We therefore postulate an intermediate state in the radiationless pathway. Then the model does yield the desired frequency dependence of the quantum yield. It may be that the arbitrary variation of the quantum yields of organic molecules may be due to the absence or presence of such an intermediate state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.454185
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  • 5
    Electronic Resource
    Electronic Resource
    Self-Assembled Monolayers of Resorcin[4]arene Tetrasulfides on Gold (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 6853-6862 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00131a007
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  • 6
    Electronic Resource
    Electronic Resource
    Lack of association between five polymorphisms in the human glucocorticoid receptor gene and glucocorticoid resistance (1997)
    Springer
    Human genetics 〈Berlin〉 99 (1997), S. 663-668 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Glucocorticoid resistance due to mutations in the gene for the glucocorticoid receptor has been suggested to be more common than is thought at present, owing to the relative mildness of its symptoms and the difficulty of its diagnosis. To investigate the prevalence of mutations in the glucocorticoid receptor gene responsible for relative insensitivity to glucocorticoids, we carried out polymerase chain reaction/single-strand conformation analysis of the glucocorticoid receptor gene in a group of 20, otherwise healthy, persons with a reduced response in a dexamethasone suppression test and in 20 controls. We did not find mutations or polymorphisms associated with a reduced sensitivity to glucocorticoids. However, we identified five novel polymorphisms in the gene for the human glucocorticoid receptor, which may be useful in analyzing whether loss of (part of) the glucocorticoid receptor gene plays a role in glucocorticoid-resistant malignancies. Although relative resistance to glucocorticoids seems to be rather frequent in otherwise healthy persons, it is not usually associated with mutations or polymorphisms in the glucocorticoid receptor gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004390050425
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  • 7
    Electronic Resource
    Electronic Resource
    Conditional inhibition of β-glucuronidase expression by antisense gene fragments in petunia protoplasts (1993)
    Springer
    Plant molecular biology 23 (1993), S. 45-55 
    Details
    ISSN: 1573-5028
    Keywords: Key words ; antisense RNA ; β-glucuronidase ; protoplasts ; transient gene expression ; PCR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Antisense RNA-mediated inhibition of gene expression is a valuable tool to induce mutant phenotypes. We are interested in the application of antisense gene fragments with the aim to improve the efficiency of inhibition and to be able to selectively suppress gene family members in plants. Protoplasts may provide a rapid system to screen the efficiency of antisense gene segments. As a first step, we set up a transient expression system for leaf protoplasts of Petunia hybrida and used as a model system the inhibition of β-glucuronidase (uidA) expression by uidA antisense gene segments. Both GUS enzyme activities and uidA RNA levels were measured. Co-introducing equal amounts of a full-length uidA antisense gene and a uidA sense gene reduced GUS activity by 60–70%. Various uidA antisense fragments also inhibited expression although with different efficiencies and we show that strong antisense fragments can be retrieved from weak antisense gene fragments. A promoter-less antisense gene did not reduce uidA expression indicating that the inhibition is mediated by antisense transcripts. Using quantitative PCR on first-strand cDNA we show that expression of functional antisense genes lead to reduced levels of uidA mRNA. This suggests that the mechanism of antisense RNA inhibition in protoplasts is similar to that in transgenic plants and that the protoplast system in combination with PCR can be used to preselect antisense fragments of any gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00021418
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  • 8
    Electronic Resource
    Electronic Resource
    Inhibition of flower pigmentation by antisense CHS genes: promoter and minimal sequence requirements for the antisense effect (1990)
    Springer
    Plant molecular biology 14 (1990), S. 457-466 
    Details
    ISSN: 1573-5028
    Keywords: antisense RNA ; chalcone synthase (CHS) gene ; Petunia hybrida
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Introduction of a constitutive antisense full-length chalcone synthase (CHS) cDNA gene in petunia can result in an inhibition of flower pigmentation. We have evaluated some of the factors which may be important for the effectiveness of an antisense CHS gene. Antisense CHS genes encoding half-length or quarter-length RNA complementary to the 3′ half of CHS mRNA are able to affect flower pigmentation, while a gene encoding RNA complementary to the 5′ half of CHS mRNA did not show phenotypic effects in transgenic petunia plants. We demonstrate that the RNA encoded by the latter gene has a much lower average steady-state level in leaf tissue than the RNAs encoded by the other antisense gene constructs. We have compared the CaMV 35S and endogenous CHS promoter strengths and intrinsic stabilities of sense and antisense CHS RNAs. From the data we conclude that the constitutive antisense CHS genes are not likely to provide an excess of antisense RNA compared to the CHS mRNA derived from the endogenous genes. Effective inhibition of flower pigmentation is also observed when the antisense CHS gene is under control of the homologous CHS promoter. The results indicate that the mechanism of antisense inhibition cannot solely operate via RNA duplex formation between sense and antisense RNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00027492
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  • 9
    Electronic Resource
    Electronic Resource
    Antisense chalcone synthase genes in petunia: Visualization of variable transgene expression (1990)
    Springer
    Molecular genetics and genomics 220 (1990), S. 204-212 
    Details
    ISSN: 1617-4623
    Keywords: Flavonoids ; Antisense genes ; Chalcone synthase ; Chalcone flavanone isomerase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The constitutive expression of an antisense chalcone synthase (CHS) gene in transgenic petunia plants results with high frequency in a reduced flower pigmentation due to a reduction in the CHS mRNA steady-state level in floral tissue. Here we show that this reduction is specific for CHS mRNA; chalcone flavanone isomerase (CHI) and dihydroflavonol reductase (DFR) mRNA steady-state levels are unaffected. However, in white floral tissue a severe reduction in CHI specific activity is found, accompanied by an altered signal for CHI protein on western blots. We find no correlation between the phenotypic effect of the antisense CHS gene and its chromosomal position. For some of the antisense CHS transformants the flower phenotype is highly variable. We demonstrate that pigmentation in these plants can be influenced by gibberellic acid and light, suggesting that the variable flower phenotype is caused by changes in physiological conditions during flower development. The results not only indicate that flower pigmentation in these plants reveals the variable expression of the antisense transgene, but also show that genomic sequences flanking the transgene may render its expression extremely susceptible to physiological conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00260483
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