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Phonon replicas are investigated at the electric field induced Γ-X transition in GaAs/AlAs coupled quantum well structures by photoluminescence spectroscopy. In the real- and k-space indirect regime the observed replicas are assigned to AlAs LO, TO and LA zone-edge phonons. At the indirect-direct transition those phonons disappear and a new replica emerges, which is assigned as a GaAs-LO phonon at the Γ-point. The observed phonon replicas are shown to be a local probe for the distribution of the ground state electronic wave function in the GaAs/AlAs coupled quantum well structure.

The photoluminescence (PL) of excitons confined in an electric field tunable coupled AlAs/GaAs quantum well has been investigated at T[MATH]350 mK and magnetic field H[MATH]14 T. In the indirect regime when electrons and holes are separated both in real- and in k-space, magnetic field was found to result in (i) a strong change of both the PL intensity and decay time which is attributed to the anomalies in the exciton transport and (ii) an appearance of a huge broad band noise in the PL intensity which is an evidence of exciton condensation.

Quantum wires and dots have been fabricated by local interdiffusion of undoped GaAs/AlGaAs quantum well structures. Thermal interdiffusion is induced by a focused laser beam. In periodic arrays of quantum wires the photoluminescence (PL) splitts into several predominant lines which are separated by up to about 8meV. These PL lines are attributed to the quantum number conserving optical transitions between 1-dimensional electron and hole levels. Sample inhomogeneities cause broadening of the lines. The transition peaks shift in energy scanning a PL probe with a size of only one micron across the structures. Inhomogeneous line broadening is eliminated by investigation of a single quantum dot. A series of dots with different size show a systematic behaviour of PL blueshift and PL peak splitting. The main peaks in PL and PL excitation (PLE) spectra coincide well in energy and they are separated by up to about 10meV. These peaks can be described by the allowed transitions between 0D single particle levels within the nearly parabolic potentials caused by interdiffusion. Detailed calculations of excitonic states within the structures result in similar optical spectra. The observation of intense luminescence from excited dot levels indicates a slowing down of the energy relaxation of carriers. This is in good agreement with calculated LA phonon emission rates of carriers in 0D systems. At low excitation density PL lines from a single quantum dot reveal widths of less than 0.5meV.

In this study the potential of combining high‐resolution hydraulic tomographic and geophysical tomographic measurements to define site‐specific relationships between geophysical and hydraulic parameters was investigated. We exploit the high‐spatial resolution of hydraulic and geophysical tomographic images to define a representative and reliable site‐specific relationship, if it exists, over an area, where geophysical and hydraulic tests are performed. The parameters involved in this study were: seismic P‐wave velocity derived from seismic tomography; resistivity and electrical conductivity derived from electrical tomography (ERT); diffusivity, hydraulic conductivity and specific storage derived from hydraulic tomography. We derived a site‐specific correlation function between the parameters P‐wave velocity and diffusivity that shows the highest correlation of all hydraulic and geophysical parameter combinations. The transformation of the P‐wave velocity field into a diffusivity field using the estimated site‐specific correlation function allowed us to increase the significance of hydraulic tomographic as well as seismic tomographic measurements with respect to the spatial diffusivity distribution in the near subsurface.

We present a micromechanically tunable long-wavelength vertical-cavity surface-emitting laser with a buried tunnel junction aperture and a stable half-symmetric cavity for full mode control. The conjunction of the active part 'half-VCSEL' and the curved MEMS-mirror in a two-chip assembly enables high output power singlemode emission exceeding 1 mW. Electrothermal actuation of the micromechanical chip allows us to extend the single wavelength performance to a continuously tunable, selectively wavelength-addressable spectrum of 28 nm. The concave curvature and the resulting long air-gap cavity are designed to favour the resonance of the fundamental mode, i.e. to match the phase front predicted by Gaussian beam theory corresponding to the aperture diameter of 10 µm. The spatial beam profile of the MEMS-VCSEL is measured in the far-field and compared with a conventional VCSEL with a fixed plane top mirror. The polarization is controlled by a dominating mirror asymmetry. High sidemode suppression over the whole tuning range with respect to both the transverse modes (>40 dB) and the polarization modes (>30 dB) is demonstrated.

Background The incidence of clinically relevant anastomotic leaks after upper gastrointestinal surgery is approximately 4% to 20%, and the associated mortality is up to 80%. Depending on the clinical presentation, the treatment options include surgery, conservative treatment with or without external drainage or endoscopic treatment. Methods This report presents nine cases of anastomotic leaks or fistulae after surgery for upper gastrointestinal cancers that were treated by insertion of a Vicryl plug and sealing with fibrin glue. Under sedation, all nine patients underwent endoscopic lavage of the cavity at the site of anastomotic leakage. The entrance to the cavity then was filled with Vicryl mesh and sealed off with fibrin glue. After the procedure, the patients underwent endoscopy and a water-soluble contrast study for assessment of the result. Results Seven of the nine patients had complete healing of the anastomotic leak or fistula after one to two endoscopic treatments. In one case, the treatment failed immediately because of a large and direct tracheoesophageal fistula. Another patient experienced recurrent intrathoracic abscesses after initial technical success. Conclusions Postoperative upper gastrointestinal fistulas or anastomotic leaks can be managed successfully with little morbidity by means of endoscopic insertion of Vicryl mesh with fibrin glue, thereby avoiding repetitive major surgery and its associated risks.

This is the first description of venocutaneous fistula, a late complication of elective laparoscopic cholecystectomy that arose 18 months after the initial operation. Postoperatively, the patient twice developed an abscess in the abdominal wall at the former site of the umbilical trocar. The first abscess occurred on the 6th postoperative day; the second, after 14 months. After an additional 4 months, a fistula opening appeared just below the umbilicus. Fistulography revealed a connection with the venous system of the omentum majus. During subsequent resection of the fistula, a pigment gallstone was retrieved from the base of the fistula.

The gain characteristics of stacked self-assembled InAs/GaAs quantum dots (QDs) with an inhomogeneous broadening of the order of 100 meV are studied in comparison to an InGaAs quantum well. The QDs exhibit gain already at low current densities of ∼25 Acm—2 per QD layer, but the peak gain rises slowly with increasing current density. The energy of the peak gain is shifted from the low energy tail of the QD emission at low injection towards the wetting-layer at high injection.

We report on vertical and lateral intersubband photocurrent (PC) spectroscopy on self-assembled In(Ga)As/GaAs quantum dots (QDs). Transitions from bound states in QDs to the GaAs continuum have been observed in vertical PC measurements. These transitions are nearly independent of polarization of the incident light. Transition from QD bound state to the wetting layer subband has been observed in lateral PC spectra. A fine structure of the first excited state in QD can be resolved with in-plane polarization dependent measurements. We present a consistent energy band diagram of self-assembled In(Ga)As/GaAs QDs by comparing photoluminescence and infrared photocurrent data.

In this paper, we investigate the dynamics of amplified spontaneous emission (ASE) in self-assembled InAs/GaAs quantum dots. Upconversion is used to time-resolve the emission from an edge-emitting waveguide structure at room temperature which is excited by short laser pulses in a stripe geometry. We demonstrate that increases in both the electron–hole pair density and the stripe length significantly decrease the emission decay time from around 2 ns, corresponding to spontaneous emission, to about 0.9 ns, corresponding to stimulated emission or ASE. A simulation of the ASE process in this geometry is in agreement with our experimental results.

We present results on spectrally resolved photo-resistance studies of optically induced charge storage effects in self-organized InAs quantum dots (QDs). The stored charge can be detected and erased electrically. Our results show that spectrally resolved optical QD charging provides information on carrier dynamics in the QDs. We find a difference in the charge redistribution effect within the inhomogeneous distribution of the QD ground state ensemble for stored electrons as compared to stored holes at a given temperature. For electron storage the spectrally resolved photo-resistance measurements show a shift of the stored charge ensemble with respect to the PL emission spectrum of the QD ensemble. For hole storage a symmetric broadening of the stored charge ensemble is found.

We investigate absorption of a single InGaAs/GaAs quantum dot by multi-channel photoluminescence excitation spectroscopy as a function of magnetic field. We find strong resonances corresponding to GaAs LO phonon-assisted absorption and unexpected phonon-assisted generation of biexciton states. Magnetic field induced detuning of the resonance conditions results in a twofold diagonal splitting of the exciton line. This indicates spin conservation in the phonon-assisted absorption process and the successive recombination process. In contrast to the exciton line a symmetric fourfold splitting is observed for the biexciton resonances. Those findings are explained in terms of sequential biexciton generation followed by sequential biexciton decay.

We report on the transmission electron microscopy characterization of InAs Stranski-Krastanov layers grown on GaAs (001) by molecular beam epitaxy at growth temperatures of 480 and 530 °C. Chemically sensitive reflections are used for the evaluation of the composition. The different influence of strain effects on the imaging with either the (002) or the (020) reflection is discussed. The considerations show that the (002) reflection can be used for an accurate measurement of the In concentration. The evaluation of concentration profiles of the wetting layers reveal a segregation probability of R = 0.77 ± 0.02 for TG = 480 °C and R = 0.82 ± 0.02 for TG = 530 °C.

AbstractFor the development of gene therapy protocols based on polyomavirus-like particles, we describe a method for fluorescence labelling of virions in order to study virus-cell interactions preceding gene delivery. Site-specific fluorescence labelling of polyomavirus-like particles is achieved via a single cysteine residue and maleimide conjugates of fluorescence dyes (fluorescein, Texas Red). Polyomavirus-like particles can be assembled in vitrofrom recombinant capsomers produced in E. coli. Since the assembly process is independent of disulfide bond formation, all cysteine residues of the wild-type protein were replaced by serines, and a new unique cysteine residue was introduced for the attachment of the fluorescence marker.

A selfconsistent second order perturbation theory on the basis of the pseudopotential method is used to calculate the disorder-induced corrections to the virtual crystal band-structure of the lattice-matched ternary alloys AlxGa1—xAs and AlxGa1—xP. The corrections are given in terms of a x- and k-dependent complex self-energy, which is found to be negligible at the valence band maximum in both AlxGa1—xAs and AlxGa1—xP. For the lowest conduction band the x- as well as the k-dependence of the corresponding real and imaginary parts are presented. In the case of AlxGa1—xAs the x-dependence of both the real and imaginary part shows partially significant deviations from a simple x(1—x) behaviour due to the direct-indirect crossover at xc  0.4. Nevertheless, by fitting the entire x-dependence of the real part with respect to —bx(1—x) bowing parameters b for the Γ- and X-gap have been obtained in remarkably good agreement with experimental values. For the less investigated L-gap a value of b  0.17 eV has been found. Investigation of the k-dependence of the real part around the Γ-point yields an increase of the Γ-electron effective mass with respect to the linear interpolated values especially in the direct gap region. The x-dependence of the imaginary part at the Γ-point reproduces the experimentally observed increase in the broadening of the Γ-electron states for x > xc very well. For the always indirect AlxGa1—xP the x-dependence of the real and imaginary part can be well described by relations ∝ x(1—x). The k-dependence is similiar to that of AlxGa1—xAs excepting the anomaly in the real-part behaviour near Γ.

The value of the pedicled intercostal muscle flap for the closure of postpneumonectomy bronchopleural fistulas was studied retrospectively.

Abstract: We report about spatially resolved experiments on self-assembled InGaAs quantum dots. Single quantum dots can be investigated by using STM-induced luminescence spectroscopy. The quantum dot occupancy can be increased via the STM tip current, which results in state filling and therefore in the onset of discrete excited state luminescence. In the limit of low injection currents, a single emission line from the ground state of the dot is observed. Using near-field spectroscopy through shadow masks, we have investigated the optical properties of single self-assembled InGaAs quantum dots as a function of occupancy and magnetic field. This allows us to fully resolve diamagnetic/orbital effects, Zeeman splitting, and to determine manybody-corrections. Photoluminescence excitation spectra further reveal a strong contribution of phonon assisted processes in quantum dot absorption.

A direct method for determining ultratrace inorganic impurities in high-purity water is presented, which consists in activation of a large volume of water (250 ml) by reactor neutron activation, subsequent gamma spectrometric assay and concentration evaluation by the monostandard procedure. The method requires neither preconcentration nor postconcentration and provides a sensitivity for a large number of elements in the concentration range of parts per trillion (ppt: 10-12 g/g) or even much less. Using the method, over twenty different ultratrace elements are quantitatively determined in two different high-purity waters, i.e., bidistilled water and water from a Super-Q system. Problems involved in analysing such highpurity waters are discussed.

Abstract: The dynamic Stark effect of the spectral lines Hβ and of the neutral helium lines λ=402.6 nm (23 P 0−53 D) and λ=438.8 nm (21 P 0−51 D) emitted from a discharge tube was used for probing rf electric fields in a transverse waveguide. Calculations accounting for the pertubation of the atomic states by strong unidirectional fields prove to be suitable in order to interprete the main experimental results. If the waveguide is terminated with a metallic reflector and the plasma in the discharge tube becomes overdense—then representing a slightly permeable mirror—a resonant enhancement of the electric field strength may be achieved by tuning. This enhancement is well recognizable in the spectral line contours.

The electronic properties of a p–i–n diode with a superlattice in the intrinsic region is investigated by optical and electrical measurements. The results of optical study clearly indicate a formation of localized Wannier-Stark states in the intrinsic region. In addition, the measured derivative of Zener current reveals several peaks which correspond well to the Wannier-Stark states.These results indicate that the observed peaks arise from Wannier-Stark resonance of Zener current which has been theoretically predicted.

We have investigated the energy spectrum of a superlattice with wide quantum wells under the bias of an electric field perpendicular to the superlattice layers. By using photocurrent spectroscopy, transitions of Wannier–Stark levels for the various electron and hole states are observed, and at low fields, further structures corresponding to miniband edge transitions are found. Various anticrossings could be observed at higher and lower electric fields. The anticrossings at high electric fields are due to energy alignment of different electronic sublevels in adjacent wells. The anticrossing structures at low fields could be interpreted as resonances between intrawell and interwell excitonic Wannier–Stark states with equal sublevel states, where the anticrossing is caused by differences in exciton binding energy. Fitting of transitions and anticrossings was done by using a semi-empirical model and we have extracted relevant fitting parameters like the quantum-confined Stark coefficient, binding energies for the excitonic Wannier–Stark levels and the resonant coupling strength for states involved in the various anticrossing transitions. Finally, insight into the excitonic influences on the coupling of the WS states could be obtained by comparing the fitted parameters for the various transitions.

A resonant coupling mechanism is presented which leads to nearly full absorption of an electromagnetic wave in an overdense plasma column. In the resonance case a strong enhancement of the electric field strength within the plasma is found. Under certain conditions this high electric field strength causes parametric excitation of plasma waves in the underdense edges of the discharge. It turned out that the occurance of this decay process is mainly determined by the density gradients in the plasma.

In 8 patients with idiopathic chronic urticaria suction blisters were produced simultaneously on lesional and perilesional skin in the periumbilical area without application of heat. The suction pressure was 250 mm Hg, and thus the blister production lasted from 60–120 min. The blister fluid histamine was determined with a modified autoanalyzer technique developed by Siraganian. In this method the extraction of histamine, the condensation of o-phthaldialdehyde with histamine and the measurement of the fluorochrome is automated. With the described method it is possible to measure values less than 0.5 ng/ml.

The lateral potential superlattice accompanying a surface acoustic wave on a semiconductor quantum well structure is employed to efficiently transform light into a long-lived electron–hole polarization that can be reassembled into photons after very long storage times. Both the location of the emission process on the sample and the storage-time can be chosen at will as the dynamical superlattice is able to transport the photogenerated excitations over macroscopic distances across the semiconductor sample. The ionization process of the photogenerated excitons in the piezoelectric fields of the sound wave can be directly observed by the absorption of a second sound wave probing the areal conductivity of the photogenerated charges.

Low temperature STM-cathodoluminescence spectroscopy has been performed on single self-assembled InGaAs quantum dots. Specially designed samples with an electron injector have been grown by MBE on a GaAs substrate, which allow for controlled state filling in the self-assembled dots. Our samples have been analyzed by both spatially resolved photoluminescence and STM-cathodoluminescence. In contrast to the inhomogeneously broadened photoluminescence the STM-cathodoluminescence shows sharp excitonic lines corresponding to discrete levels of a single dot. The occupancy of the dot can be increased in a controlled way via the STM tip current, which results in state filling and therefore in the onset of discrete excited state luminescence. In the limit of low injection currents a single emission line from the ground state of a single dot is observed.

We have investigated the influence of the final states of bound-to-continuum transitions within the conduction band of asymmetric quantum well structures on the photocurrent. This influence manifests itself by an energy-dependent oscillation of the current direction. We observe pronounced oscillations at zero bias voltage in a double quantum well structure, induced by an asymmetric excitation into continuum states with positive and negative momentum, i.e. by a photogalvanic effect (PGE). If this effect is superimposed on an asymmetric backrelaxation, similar oscillations are observed in the spectrum when the latter asymmetry is compensated by an external electric field. Theoretically, we find a strong relation between the PGE and a quantum interference effect occurring in the continuum.

Applying delayed?- r.f. coincidences and generalized centroid-shift analysis, nanosecond isomers in some odd-A iodine isotopes are studied in-beam. The reactions106Cd(12C,p2n) and116,118Sn(6Li,3n) have been used. The following half-lives were determined:T1/2(565 keV)=0.50±0.10 ns andT1/2(837 keV) =0.90±0.20 ns in115I,T1/2(687 keV)=5.50±0.50 ns andT1/2(2418 keV)=4.0±0.50 ns in119I as well asT1/2(812 keV)=0.35±0.20 ns andT1/2(445 keV)<0.10 ns in121I. A systematics of the absolute probabilities for the transitions deexciting thepg9/2 9/2+ andp11/2 11/21- band heads in115–125I is presented and discussed.

Abstract: Neutron activation analysis is shown as a useful diagnostic technique in semiconductor industry. A better acceptance of the method for applications in industry has been achieved through a specialized analytical service. Its main application is the characterization of high purity silicon in all stages of production. Irradiation of large sample volumes allowes a very sensitive detection of impurities in silicon with detection limits down to 10–16 g/g. Other applications discussed are the analysis of silicon carbide, quartz, pure water and titanium. Special techniques described are autoradiography, depth profiling and surface analysis. In semiconductor process technology NAA was used to monitor contamination of silicon wafers.

The mean lifetimes of the lower spin states of the superdeformed band in133Nd have been measured with the coincidence recoil distance method. The reaction used to populate the band was105Pd (32S, 2p2n)133Nd at a beam energy of 152 MeV, and the gamma-rays were detected with the POLYTESSA array. The differential decay curve method was used to analyse the data and transition quadrupole moments,Q0, were extracted from the measured lifetimes. The results obtained from the three lowest transitions in the superdeformed band are:Q0=6.3±0.9 eb (21+/2?17+/2),Q0=6.7±1.1 eb (25+/2?21+/2) andQ0>5.0 eb (29+/2?25+/2). These results are consistent with previous results for the high spin members of the band, and are compared to theoretical calculations of total routhian surfaces. The calculation of reduced transition probabilities for the transitions that feed out of the band, allows the effect of hindrance due to K-forbiddenness to be investigated.

By means of the generalized centroid-shift method, the following half-lives were determined:T1/2(3045 keV)=3.7±0.3 ns in113Sb using the reaction104Pd(12C,p2n) as well asT1/2 (1322.8 keV)=3.5±0.3 ns,T1/2(2779.8 keV) =0.50±0.15ns,T1/2(2874.9 keV)<0.2 ns andT1/2(3072.9 keV)<0.1 ns in117Sb using the116In(a, 2n) reaction. Three-quasiparticle configurations of the type pd5/2?(h11/2d3/2) in113,117Sb are found to dominate in the wave functions of the 19/2- states at 3045 and 2780 keV in113Sb and117Sb, respectively. TheB(E2, 19/2- ? 15/2-) values in113–119Sb are discussed.

In 196 children aged between 4 weeks and 16 2/12 years a sonographic investigation of kidneys was performed and put into relation to somatometric data including bodyweight (BW) bodylength (BL), length of the trunk and the upper and the lower limb, breadth of thorax and pelvic, head circumference, maximum cranial length and maximum cranial breadth. None of the children had signs of renal disorder. Morphometric data, as kidney length, width, depth, parenchymal areas in longitudinal and transverse sections and the prolate ellipsoid volume (PEV) were documented. The children were divided into five groups (group 1: 2–6 months, group 2: 6–31 months, group 3: 31–99 months, group 4: 99–131 months, group 5: 131–194 months). Mean values of all parameters were calculated. For each group a multiple regression analysis was performed and a regression equation of kidney length, parenchymal areas and volume was established. This method allows an individual determination of renal size and parenchymal mass.

In plasmas produced by microwave power the electron density displays a dependence on the magnetic field strength obviously asymmetric with respect to the harmonics of the electron cyclotron frequency. In regions of the magnetic field strength just above the harmonics there are extremely high values of electron density, the density values dropping sharply off towards the other wing of the harmonics.

We report about optical experiments on (i) natural quantum dots formed by well width fluctuations in narrow GaAs quantum wells and on (ii) self-assembled InGaAs quantum dots in GaAs. Contributions from a single natural quantum dot are isolated by spatially resolved spectroscopy and resonant charge injection in an electric-field-tunable coupled quantum well structure. In optical experiments the excitonic and bi-excitonic ground states are identified and growth related interface problems are analyzed. Spectral linewidths down to 50 meV allow thereby a complete separation of the individual levels and Zeeman sub-levels of the dot. The natural quantum dots with their fully resolved Zeeman levels are used as local probes to monitor the spin orientation and the creation of spin-polarized excitons in coupled quantum well structures. With cathodoluminescence excited by a scanning tunneling microscope tip and a special sample design we are able to excite selectively the ground state of a single self-assembled InGaAs quantum dot.

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Zusammenfassung Wir berichten über eine mittels Selektivkultur zufällig entdeckteLegionella pneumophila Typ I-Pneumonie bei gleichzeitigem Nachweis von Pneumokokken, Meningokokken undHaemophilus influenzae in der üblichen Sputumkultur. Ein 35jähriger Patient war nach tagelangen Prodromi mit den typischen Zeichen einer Legionellose zur stationären Aufnahme gekommen: Ausgeprägte Pneumonie mit den Zeichen einer kardialen, hepatischen, renalen und zerebralen Mitbeteiligung. Die übliche bakteriologische Sputumdiagnostik nach DGHM-Richtlinien erbrachte zunächst Pneumokokken, Meningokokken undH. influenzae in relevanter Konzentration. Auf dem routinemäßig mitgeführten Spezialnährboden nachEdelstein (BMPA a-Medium) wuchs wenig späterL. pneumophila Typ I. Der Nachweis von Legionella Typ I-spezifischen Serum-AK mittels IIFT erhärtete die Diagnose „Legionellose“. Unter der Therapie mit Amoxicillin-Clavulansäure und Cefoxitin erfolgte rasche Entfieberung mit Normalisierung der Laborparameter und Rückbildung des pulmonalen Infiltrates. Ohne die kulturelle Anzüchtung vonL. pneumophila wäre die Diagnose einer Legionellose nicht gestellt worden.

Water-soluble UV-A/B-absorbing pigments are secreted by cells of the cosmopolitan terrestrial cyanobacterium Nostoc commune. The pigments constitute a complex mixture of monomers with molecular masses of up to 1801 Da. Two different chromophores with absorption maxima at 312 and 335 nm are linked to different amino acids and to oligosaccharides consisting of galactose, glucose, xylose, glucuronic acid, and glucosamine. The 335 nm chromophore is a 1,3-diaminocyclohexen derivative, while the chromophore with an absorption maximum at 312 nm is most likely a 3-aminocyclohexen-1-one derivative. These UV-inducible substances are the first mycosporines to be described covalently linked to oligosaccharides. The pigments are located in the extracellular glycan sheath of Nostoc colonies, where they form complexes of extremely high molecular mass that are attached noncovalently to the glycan sheath. Pigments occur in concentrations that permit the cells to attenuate a significant part of incident UV-B radiation.

Summary Three femoral endoprosthetic stems implanted without cement, made off Ti-6Al-4V alloy, with implantation periods of between 2 and 4 years were examined histologically in the form of undecalcified thin ground sections after having been split into segments and embedded in plastic. During the implantation period total osseointegration in the metadiaphyseal region takes place, while in the proximal area reaction forms with direct contact between metal and bone on the one hand and with an interposed membrane of connective tissue and adjacent secondary bony shell on the other must be distinguished. The osseointegration of the stem is the result of a primary healing of the bone and is due to the biocompatibility of the metal alloy and to the primary stability obtained by the press-fit method.

A systematic investigation is presented of the variation of isochromat structures with threshold voltage (quantum energies). With a double focusing X-ray monochromator highly resolved bremsstrahlung isochromats of tungsten are measured in the quantum energy range from 0.15 to 6 keV. Crystals with lattice constants up to about 50 Å could be used as dispersing devices.

Zusammenfassung Die Autoren haben mittels der Radialimmundiffusionsmethode vonMancini, Carbonara, Heremans bei 64 gesunden Erwachsenen, 34 lymphoiden Leukamien und 16 Paraproteinämien die IgA-Konzentration von Serum und Speichel bestimmt. Auch bei den normalen Fällen bestand zwischen dem IgA-Spiegel des Serums und des Speichels keine Korrelation. Bei den myeloiden Leukämien zeigte das IgA des Serums eine mäßige, bei den lymphoiden Leukämien und Paraproteinämien eine signifikante Verminderung. Die IgA-Konzentration des Speichels hingegen war bei Leukämien eine mäßig erhöhte, bei Paraproteinämien stimmte sie im wesentlichen mit der Kontrolle überein.

In this work a radiofrequency powered helium discharge plasma (RFP) for optical or mass spectrometry purposes was developed and investigated. Research focussed on the spectroscopic properties of the RFP, and its suitability as an alternative excitation source for plasma spectroscopy was proved. Halogenated organic compounds were injected into the gas flow to detect fluorine, chlorine, bromine and iodine at their most intense spectral lines resolved from interferences. With this plasma, the detection of Cl down to 125 ng without background correction is possible. Injection of air samples causes few interferences and shows the robustness of the radiofrequency plasma against large sample volumes of up to 500 μL. A Cl selectivity against N₂, O₂ (both more than 5000:1) and C (250:1) is achieved without background correction. A fluorine quantification is possible for 0.25 μg only. I and Br detection also can be achieved down to 0.25 μg without any background correction.

From neck ligation experiments with last instar larvae of the cockroachPeriplaneta americanait was concluded that the head critical period is reached around day 17, which corresponds to 59% of the last larval stage. At the same stage the juvenile hormone III titre in the hemolymph dropped to undectable levels.

Yrast as well as non-yrast states of114Sn have been investigated via the100Mo(18O,4n) and the112Cd(a,2n) reaction by means of in-beam?-ray spectroscopy using the Compton-suppressed germanium detector array OSIRIS-Cube. A new rotational band including the band head with a tentative spin and parity assignment of 5- could be placed in the level scheme and might be a candidate for apg92/-1h11/2 intruder band.