A FLUORESCENCE IMAGING DEVICE FOR ENDOSCOPIC DETECTION OF EARLY STAGE CANCER – INSTRUMENTAL and EXPERIMENTAL STUDIES

Abstract Visible detection of early stage cancer labelled with the fluorescing porphyrin mixture of dihematoporphyrin-ether and dihematoporphyrin-ester (DHE) is often limited by a high and inhomogeneously distributed level of autofluorescence. A new imaging method for reducing autofluo-rescence is described. The method uses alternating fluorescence excitation with laser light in the violet and blue spectral ranges. Subtraction of the corresponding fluorescence images results in contrast enhancement due to an effective reduction in the autofluorescence contribution. A prototype version of a highly sensitive fluorescence imaging device including a modified krypton ion laser, an image-intensified solid-state TV-camera, a digital image-processing system, and video recording and monitoring has been developed.
Experiments performed with this fluorescence imaging system on a tumorous dog bladder showed that a dose of 0.2 mg DHE kg⁻¹ body wt, which is far below the dose administered for photodynamic therapy (2-5 mg kg⁻'body wt), is sufficient to give a high-contrast fluorescence image. The corresponding excitation power density was about 1 W m⁻². Photobleaching of DHE was observed during fluorescence detection at excitation power densities exceeding 1 kW m⁻². At these high excitation levels DHE fades out nearly completely within 0.25 min.     

Lower Transport Bounds for One-dimensional Continuum Schrödinger Operators

We prove quantum dynamical lower bounds for one-dimensional continuum Schrödinger operators that possess critical energies for which there is slow growth of transfer matrix norms and a large class of compactly supported initial states. This general result is applied to a number of models, including the Bernoulli–Anderson model with a constant single-site potential.     

An ergodic theorem for Delone dynamical systems and existence of the integrated density of states

We study strictly ergodic Delone dynamical systems and prove an ergodic theorem for Banach space valued functions on the associated set of pattern classes. As an application, we prove existence of the integrated density of states in the sense of uniform convergence in distribution for the associated random operators. Dedicated to J. Voigt on the occasion of his 60th birthday Research partly supported by the DFG in the priority program Quasicrystals.     

Poly(alkyl α-chloroacrylates). IV. Tacticity analysis from 300 MHz proton magnetic resonance spectra

300 MHz proton magnetic resonance spectroscopy was applied to the determination of triad structures of three poly(alkyl α-chloroacrylates) of widely varying stereoregularities. Assignments and quantitative analyses were made for all of the tetrad peaks in the backbone methylene resonance of poly(methyl α-chloroacrylate), poly(ethyl α-chloroacrylate), and poly(isopropyl α-chloroacrylate). In addition the methyl singlet peaks of poly(methyl α-chloroacrylate), the methyl triplet peaks of poly(ethyl α-chloroacrylate) which had not been amenable previously to resolution at 220 MHz, and the methyl doublet peaks of poly(isopropyl α-chloroacrylate) were resolved, and the triad values which were obtained from these pendant ester group resonances compared favorably with triad values calculated from experimental tetrad values. As a demonstration of the internal agreement of the triad and tetrad peaks assignments, statistical calculations of the stereochemical structures of the actic and syndiotactic polymers were generally described well or to a first approximation by random selection statistics (Bernoullian) while the stereochemical statistics of the moderately to highly isotactic polymers were consistent with a nonrandom statistical process (first-order Markovian), as expected.     

The Δ-nucleus spin-orbit interaction in π-nucleus scattering

The role of the Δ-nucleus spin-orbit interaction in π-nucleus scattering is studied within the isobar-hole formalism. Due to the peripheral nature of the π-nucleus interaction, elastic scattering is very sensitive to the presence of such an L-S term. We report results for pion scattering on light nuclei in the resonance region. The systematics of the phenomenological Δ-nucleus optical potential are discussed.     

Über die Einführung einer absoluten Polarität in die projektive und affine Geometrie des Raumes

Ohne Zusammenfassung     

Über die Bedeckung ebener Punktmengen durch solche kleineren Durchmessers

Ohne ZusammenfassungHerrn Professor J. Lense zum 65. Geburtstag gewidmet