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  • 1
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    The @journal of organic chemistry 53 (1988), S. 3632-3634 
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 6013-6019 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: A vibrational analysis for the excitation and fluorescence spectra of the S1–S0 transition in jet-cooled indole and N-deuterated indole is presented. This analysis yields the frequencies for eight low-lying S1 vibrational modes of both isotopic species. Single vibronic level fluorescence spectra also enable us to refine many of the S0 vibrational frequencies. Quantum interference effects in the energy-resolved fluorescence decays for one vibrational level of S1 indole are observed as a result of picosecond laser excitation. Through analysis of the fluorescence spectra and the modulated fluorescence decays, the coupling responsible for the quantum beats was found to result from a zero-order in-plane mode coupled to a level which is described by several zero-order out-of-plane modes. The effect of the deuterium substitution on the quantum beats is also investigated.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 6261-6270 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The excited state dynamics of the indole(Ar)1, indole(d1)(Ar)1, indole(Ar)2, and indole(CH4)1 van der Waals clusters have been investigated in a free jet expansion. Excited state vibrational frequencies were determined using multiphoton ionization and fluorescence excitation spectroscopy. Time resolved emission spectroscopic techniques were used to determine vibrational predissociation rates and product state distributions. All of the clusters were found to predissociate when excited with sufficient vibrational energy in the S1 state. The predissociation dynamics were found to be consistent with a serial model in which energy transfer from the indole skeletal modes to the van der Waals modes precedes the dissociation step. The density of van der Waals vibrational states was found to be the most important factor in determining the predissociation dynamics.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 67-79 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: We have undertaken an extensive study of the spectroscopy and dynamics of the S1–S0 transition in jet-cooled 1-methylindole and 1-methyl(d3)indole. The energy-resolved fluorescence decays resulting from picosecond excitation of S1 vibrational modes display unusual quantum interference effects which have been attributed to the excitation of a large number of quasidegenerate states even at relatively low levels of vibrational excitation. This has been attributed to rovibrational coupling in which the selection rules are much less restrictive than is normally the case with rigid planar molecules. A significant rotational temperature dependence of the vibrational dynamics has been measured which serves to corroborate this model.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Daresbury Laboratory is currently completing the construction and commissioning of five new experimental research stations utilizing high flux hard x-ray radiation from a 6 T superconducting wiggler magnet. The broad areas of science covered by the new stations and the novel features are presented. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2027-2030 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The construction of a high-voltage (up to 1000 V) bipolar metal-oxide-semiconductor field-effect transistor square-wave generator is described. This generator is capable of producing both positive and negative going square waves with variable amplitude, repetition rate, and width. The circuit was designed for ferroelectrics research, however other applications are possible. The rise time of the prototype was 200 ns which was quite satisfactory for the present ferroelectric research project however the rise time can be decreased to 50 ns if necessary. The reader with a modest knowledge of electronics should be able to construct the circuit. Possible pitfalls and critical points are discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 2443-2448 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Fluctuations in laser beam geometry such as lateral beam movement and beam width variation can produce perturbations in the output signal of a laser interferometer through various coupling mechanisms. In order to avoid this type of laser noise from degrading the sensitivity of interferometers designed to detect gravitational radiation, currently planned long-base-line detectors will employ resonant optical filters called modecleaners to suppress beam geometry noise. Here we describe a prototype modecleaner cavity constructed at Glasgow having an optical path length of 18 m and containing four suspended mirrors. We present results detailing various aspects of its performance. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: In recent studies of transgenic models of Alzheimer's disease (AD), it has been reported that antibodies to aged beta amyloid peptide 1–42 (Aβ1−42) solutions (mixtures of Aβ monomers, oligomers and amyloid fibrils) cause conspicuous reduction of amyloid plaques and neurological improvement. In some cases, however, neurological improvement has been independent of obvious plaque reduction, and it has been suggested that immunization might neutralize soluble, non-fibrillar forms of Aβ. It is now known that Aβ toxicity resides not only in fibrils, but also in soluble protofibrils and oligomers. The current study has investigated the immune response to low doses of Aβ1−42 oligomers and the characteristics of the antibodies they induce. Rabbits that were injected with Aβ1−42 solutions containing only monomers and oligomers produced antibodies that preferentially bound to assembled forms of Aβ in immunoblots and in physiological solutions. The antibodies have proven useful for assays that can detect inhibitors of oligomer formation, for immunofluorescence localization of cell-attached oligomers to receptor-like puncta, and for immunoblots that show the presence of SDS-stable oligomers in Alzheimer's brain tissue. The antibodies, moreover, were found to neutralize the toxicity of soluble oligomers in cell culture. Results support the hypothesis that immunizations of transgenic mice derive therapeutic benefit from the immuno-neutralization of soluble Aβ-derived toxins. Analogous immuno-neutralization of oligomers in humans may be a key in AD vaccines.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1471-0528
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Objective To assess whether cervical cerclage in women deemed to be at increased risk of cervical incompetence prolongs pregnancy and thereby improves fetal and neonatal outcome.Design Multicentre randomised controlled trial.Setting Hospitals in the United Kingdom, France, Hungary, Norway, Italy, Belgium, Zimbabwe, South Africa, Iceland, Ireland, the Netherlands and Canada.Subjects One thousand two hundred and ninety-two pregnant women whose obstetricians were uncertain whether to recommend cervical cerclage, most of whom had a history of early delivery or cervical surgery.Interventions Cervical cerclage was compared with a policy of withholding the operation unless it was considered to be clearly indicated.Main outcome measures Delivery before 33 completed weeks, preterm delivery (〈37 weeks), and vital status of the baby after completion of the pregnancy.Results The overall preterm delivery rate was 28%. There were fewer deliveries before 33 weeks in the cerclage group (83 (13%) compared with 110 (17%), P=0.03) and this difference reflected deliveries characterised by features of cervical incompetence (painless cervical dilatation and prelabour rupture of the membranes). There was a corresponding difference in very low birthweight deliveries (63 (10%) compared with 86 (13%), P=0.05). The difference in the overall rate of miscarriage, stillbirth or neonatal death (55 (9%) compared with 68 (11%)) was less marked and was not statistically significant. The use of cervical cerclage was associated with increased medical intervention and a doubling of the risk of puerperal pyrexia.Conclusions These results suggest that the operation had an important beneficial effect in 1 in 25 cases in the trial (95% confidence interval (CI) 1 in 12 to 1 in 300 sutures). Its use is associated with increased medical intervention and puerperal pyrexia. Nevertheless, this trial suggests that, on balance, cervical cerclage should be offered to women at high risk, such as those with a history of three or more pregnancies ending before 37 weeks gestation.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: The effect of the Kunitz proteinase inhibitor (KPI) on potential β-amyloid precursor protein (βPP)-processing activities from control and Alzheimer's disease (AD) brains was examined using fluorogenic substrates designed to mimic the secretory and amyloidogenic cleavages in βPP. In addition, the level of secretion of KPI-containing βPP751 and KPI-lacking βPP695 from transfected cells was examined to assess the effect of the KPI on βPP secretion. βPP751 and βPP695, obtained from conditioned media of transfected cells, had no effect on proteinase activities against the secretory and amyloidogenic substrates in extracts from control and AD brains. At similar concentrations βPP751, but not βPP695, completely inhibited the activity of trypsin against these substrates. Serine proteinase inhibitors had only modest effects on activities from brain, whereas cysteine modification completely inhibited them, indicating that these proteinase activities were not of the serine type. Thus, the results do not support a role for the KPI in the secretion of βPP or in the amyloidogenic cleavage of βPP. The amounts of βPP695 and βPP751 collected from the media of transfected cells after 48 h of growth were similar, indicating an equal rate of secretion. This result suggests that the KPI domain in βPP751 did not inhibit the secretory cleavage in transfected cells.
    Materialart: Digitale Medien
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