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
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 234 (1987), S. 328-333 
    ISSN: 1432-1459
    Keywords: Oestrogen receptor ; Progesterone receptor ; Androgen receptor ; Monoclonal antibody ; Meningioma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Oestrogen receptor (ER) analysis was performed in 70 meningiomas with an enzyme immunoassay, using monoclonal antibodies against human oestrogen receptor protein (oestrophilin) and with a sensitive radioligand binding assay, using 125I-oestradiol as radioligand. Low levels of ER immunoreactivity were found in tumours from 51% of patients, whereas ER binding activity was demonstrated in 40% of the meningiomas examined. In 8 (11%) tissue samples multiple binding sites for oestradiol were observed. The immunoreactive binding sites corresponded to the classical, high-affinity ER. In ligand binding studies, however, measurement of classical ER was considerably influenced by a second low-affinity, high-capacity oestrogen binding component even at low ligand concentrations. 3H-methylpromegestone and 3H-methyltrienolone, a synthetic gestagen and androgen, were used for concurrent determination of the progesterone receptor (PR) and androgen receptor (AR) binding activity. High concentrations of PR were detected in 53 (76%), whereas moderate levels of AR binding sites were demonstrated in 33 (47%) tumours. A positive correlation between ER immunoreactivity and AR binding activity is indicative for an oestrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency for a dependence of receptor concentrations on the histological subtype could have implications for tumour therapy.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1572-9540
    Keywords: muon transfer ; exotic atom ; muonic molecule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The energy and time distributions of the decay X-rays of excited, metastable, molecular (dµHe)*-resonances were measured. The comparison of the observed energy spectra with calculated ones suggests that decay from the rotational state J = 1 dominates at the investigated conditions. The muon transfer rates from ground state deuterium to the helium isotopes 3He and 4He at low temperatures were determined from the time distributions of these spectra. Additionally, the temperature dependence of the muon transfer rate was clearly established in deuterium / 4He mixtures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1572-9540
    Keywords: exotic atom ; cascade
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The complex balance of processes occurring at the cascade of exotic H-atoms is usually described by the so-called standard cascade model, but this model neglects variations of the kinetic energy T of the exotic atom during the cascade which are crucial for the analysis of several important experiments. New experimental results on T µp at H2 pressures between 0.063 and 4 hPa demonstrate the importance of acceleration due to Coulomb de-excitation processes at highly excited µp levels n 〉 9. The data at the lowest density are sensitive to the initial values of the kinetic energy and n-levels at the moment of atomic capture. From the measured low-energy tail of the T µp-distribution it can be concluded that a considerable part of the µp(2s) atoms is metastable at pressures of a few hPa.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1572-9540
    Keywords: proton ; proton radius ; muon ; muonic hydrogen ; Lamb shift
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The contribution of the root mean square (RMS) proton charge radius to the Lamb shift (2S–2P energy difference) in muonic hydrogen (μp) amounts to 2%. Apart from the uncertainty on this charge radius, theory predicts the Lamb shift with a precision on the ppm level. We are going to measure ΔE (2 S1/2(F=1)–2 P3/2(F=2)) in a laser resonance experiment to a precision of 30 ppm (i.e., 10% of the natural linewidth) and to deduce the RMS proton charge radius with 10−3 relative accuracy, 20 times more precise than presently known. The most important requirement for the feasibility of such an experiment, namely the availability of a sufficient amount of long lived metastable μp atoms in the 2S state, has been investigated in a recent experiment at PSI. Our analysis shows that in the order of one percent of all muons stopped in low pressure hydrogen gas form a long lived μp(2S) with a lifetime of the order of 1 μs. The technical realization of our experiment involves a new high intensity low energy muon beam, an efficient low energy muon entrance detector, a randomly triggered 3 stage laser system providing the 0.5 mJ, 7 ns laser pulses at 6.02 μm wavelength, and a combination of a xenon gas proportional scintillation chamber (GPSC) and a microstrip gas chamber (MSGC) with a CsI coated surface to detect the 2 keV X rays from theμp(2P → 1S) transition.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1572-9540
    Keywords: exotic atom ; muonic molecule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present the results of an experiment performed at PSI to investigate muon catalyzed fusion in pure deuterium gas of 5% density (LHD) at temperatures ranging from 28 K to 350 K. Using a new high pressure ionization chamber the reactions dd → n + 3He and dd → p+t were observed with 100% detection efficiency. The rates of dμd formation were measured with the absolute precision of 1% and the μd spin-flip rates with 0.5%. The temperature dependence of molecular formation and spin-flip rates display pronounced resonance structures. A preliminary fit based on the Vesman mechanism of resonant muonic molecule formation was carried out yielding a dd fusion rate of 3.5·108 s-1 and a hfs splitting energy $$\delta \varepsilon _{d\mu d} $$ of 24.3 meV, both in good agreement with the theory.
    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...