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Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A letter to the editor is presented concerning the article "Zero-phonon lines of nitrogen-cluster states in GaNx As1−x: H identified by time-resolved photoluminescence," from the April 8, 2008 issue.

The magneto-transport properties of granular paramagnetic–ferromagnetic GaAs:Mn/MnAs hybrids have been studied. Positive and negative magnetoresistivity can be observed in the paramagnetic matrix as well as in the GaAs:Mn/MnAs hybrid system. The experimental results and the respective relevant interactions are discussed. A phenomenological explanation from a microscopic point of view is presented. It is suggested that the paramagnetism of the matrix plays a major role in the magneto-resistive behavior of the hybrids, in contrast to diamagnetic–ferromagnetic hybrids where the magnetoresistance (MR) is dominated by the ferromagnetism of the clusters. [ABSTRACT FROM AUTHOR]

It is well established that the ferromagnetism of (Ga,Mn)As is mediated by holes. An important parameter in this context is the p–d exchange integral N0β as the RKKY interaction parameter JRKKY is proportional to ( N0β)2. In magnetic semiconductors, magnitude and sign of N0β are strongly dependent on the local electronic configuration of the Mn-ion and on the free carrier density. To investigate the correlation between the p–d exchange interaction and doping in Ga1− xMn xAs, paramagnetic samples with x ≈0.1% have been intentionally n-doped with Te. High-field Hall measurements at 1.6 K confirm that with increasing degree of Te co-doping, the samples change from p- to n-type. The magnetic field induced splitting of the excitonic and electronic states has been studied by various magneto-optical spectroscopic techniques at 1.8 K and external magnetic fields up to 7.5 T. The p–d exchange integral changes from N0β > 0 (ferromagnetic coupling) to N0β < 0 (antiferromagnetic coupling) with increasing degree of Te co-doping. Thus, N0β can be tuned and can even change its sign in dependence on the doping conditions of the Mn-containing layers. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a chronic skin disease with increasing prevalence and rising costs. Stigmatisation and pruritus are only some aspects of potential quality-of-life (QOL) impairments. AD is not curable and repeated treatments are often necessary. At present, treatment with topically-applied corticosteroids is state-of-the-art for mild to moderate flare-ups. However, many patients are worried about the use of corticosteroids due to the widespread fear of adverse effects. In this review the present literature is analysed concerning impact on quality of life for topically-applicable alternatives to the state-of-the-art treatment. For comparison reasons, data from other treatment modalities are additionally given. Characteristics of studies were analysed using ‘general’ (year and mode of publication, type and aim of study, number of patients, and clinical measurement) and ‘QOL specific’ criteria (type and number of QOL measurements including relevance for study aim and age group, validation in used language, sensitivity to change, and improvement at end of study). QOL data are published only in the minority of studies evaluating treatment efficacy and do not cover the variety of possible therapies. Data are available for tacrolimus, pimecrolimus, UVA/UVB combination and UVB narrowband (topical non-corticosteroidal treatments), as well as for topical corticosteroids, cyclosporin, and inpatient treatment. All studies provided a marked improvement in quality of life after therapy. One study assessed quality of life after a treatment-free follow-up period obtaining a clear increase in impact on quality of life. Since studies used different QOL measurements and vary in inclusion criteria, treatment schedules and presentation of results, a comparison of QOL improvement is not recommended. A single randomised study compared topically applied non-corticosteroidal treatment (UVA/UVB combination) with another treatment modality (cyclosporin) and found no difference in QOL improvement. At present, there is a clear lack of controlled randomised studies evaluating different active treatment modalities and their impact on quality of life. Consensus meetings are desirable to formulate guidelines for the selection and correct use of QOL measurements. Patients' fear of side effects (e.g. concerning corticosteroids) should be integrated in QOL questionnaires for evaluation of possible compliance problems and real costs. Since relapse after treatment is frequent in AD, QOL measurements should also be performed after a treatment-free follow-up period. At present, we can not answer the question ‘which treatment best improves quality of life in AD?’. [ABSTRACT FROM AUTHOR]

We studied the correlation between magnetoresistance (MR) effects and the type of conducti- vity in paramagnetic Ga1− xMn xAs with x < 0.5%. Series of samples of (Ga,Mn)As with different codoping levels of Te have been prepared by metal-organic vapor-phase epitaxy (MOVPE). With increasing Mn-content from doping levels to x = 0.5% in paramagnetic Ga1− xMn xAs, the MR at 1.6 K changes continuously from positive to strongly negative. This manifests the complex interplay between p–d exchange induced valence band splitting and the metal–insulator transition. Codoping with Te leads eventually to a dominant conduction band transport. It is characterized by a small negative contribution at low magnetic fields to the parabolic MR similar to that found in highly n-doped diamagnetic semiconductors. It shows that the Mn-induced conduction band splitting is much smaller than the valence band splitting, i.e., |N0α| ≪ |N0β|. [ABSTRACT FROM AUTHOR]

We investigate the impact of waveguide properties on the performance of surface-emitting second-harmonic generation (SESHG) devices. Using multi-layer AlGaAs/GaAs ridge waveguides that are optimized for SESHG at fundamental wavelengths λω = 1060 and 1550 nm, we achieve nonlinear cross-sections among the highest reported so far. In these devices, characteristics of the guided fundamental wave strongly determine the SESHG performance: multiple reflections in the longitudinal direction affect the conversion efficiency while higher order lateral waveguide modes modify the SESHG farfield. Both effects are significant for applications of SESHG in integrated photonic circuits. [ABSTRACT FROM AUTHOR]

Copyright of Der Hautarzt is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Data on the prevalence of adverse effects from dental cast alloys and on the characteristics of the related patient groups are scarce. Therefore, the aim of the present study was to investigate patients in a defined part of Germany attributing oral complaints or symptoms to dental cast alloys. All dentists in the area of Eastern Bavaria (with 1 million inhabitants) were asked to send corresponding patients to our department during a 3-year period. Out of this collection, patients with complaints or symptoms in the oral cavity were recruited and characterized with regard to number, age and sex distribution, type of subjective complaints and objective intraoral symptoms, and allergy status based on an alloy analysis. Patients reporting to our department with suspected local adverse effects from dental cast alloys represented 0.01% of the population. Thirty-four percent of the patients were 50–59 years old, with females prevailing (76%). A great variety of subjective complaints was reported, which mainly resembles those reported by patients with adverse effects attributed to other dental materials like amalgam or denture base materials. The main objective intraoral symptoms were gingivitis, anomalies of the tongue (lingua plicata, lingua geographica), discoloration of the gingiva, redness of the palate or tongue and lichenoid reactions of the oral mucosa. In not more than 10% of the patients, allergy was diagnosed as contributing to the complaints or symptoms. [ABSTRACT FROM AUTHOR]

In several phase II-trials encouraging tumour responses rates in advanced metastatic melanoma (stage IV; AJCC-classification) have been reported for the application of biochemotherapy containing interleukin 2. This study was designed to compare the efficacy of therapy with dacarbazine (DTIC) and interferon α (IFN-α) only to that of therapy with DTIC and IFN-α with the addition of interleukin 2 (IL-2) in terms of the overall survival time and rate of objective remissions and to provide an elaborated toxicity profile for both types of therapy. 290 patients were randomized to receive either DTIC (850 mg/m[SUP2] every 28 days) plus IFN-α2a/b (3 MIU/m[SUP2], twice on day 1, once daily from days 2 to 5; 5 MIU/m[SUP2]3 times a week from week 2 to 4) with or without IL-2 (4.5 MIU/m[SUP2]for 3 hours i.v. on day 3; 9.0 MIU/m[SUP2]i.v. day 3/4; 4.5 MIU/m[SUP2]s.c. days 4 to 7). The treatment plan required at least 2 treatment cycles (8 weeks of therapy) for every patient. Of 290 randomized patients 281 were eligible for an intention-to-treat analysis. There was no difference in terms of survival time from treatment onset between the two arms (median 11.0 months each). In 273 patients treated according to protocol tumour response was assessable. The response rates did not differ between both arms (P = 0.87) with 18.0% objective responses (9.7% PR; 8.3% CR) for DTIC plus IFN-α as compared to 16.1% (8.8% PR; 7.3% CR) for DTIC, IFN-α and IL-2. Treatment cessation due to adverse reactions was significantly more common in patients receiving IL-2 (13.9%) than in patients receiving DTIC/IFN-α only (5.6%). In conclusion, there was neither a difference in survival time nor in tumour response rates when IL-2, applied according to the combined intravenous and subcutaneous schedule used for this study, was added to DTIC and IFN-α. However, toxicity was increased in melanoma patients treated with IL-2. Further phase III trials with... [ABSTRACT FROM AUTHOR]

(GaIn)(NAs)/GaAs multiple quantum well (MQW) structures with high structural perfection as determined from high-resolution x-ray diffraction (XRD) analysis have been deposited by low-temperature metal organic vapor phase epitaxy (MOVPE) at 525°C using triethylgallium (TEGa) and trimethylindium (TMIn) in combination with 1,1-dimethylhydrazine (UDMHy) and tertiarybutylarsine (TBAs). The optical characteristics of as-grown MQW structures as a function of quaternary composition and of well width are established by PL spectroscopy at 300 K. With increasing N-content a reduction in PL efficiency and an increase in PL linewidth is observed. This behavior might be correlated to an increase in defect density with increasing N-content and/or to a bandstructure effect in this novel material system. For an increase in Inconcentration the tendency for a reduction in the extreme bowing of the band gap is detected. Strong quantization effects are observed for well widths below 5 nm only in this novel MQW system, which indicates significantly larger electron masses as compared to N-free (GaIn)As. [ABSTRACT FROM AUTHOR]

Natural minerals, such as widespread quartz and feldspars, have physical properties which enable them to be used as radiation dosimeters. The underlying luminescence phenomena have made it possible in recent decades to determine the age of a variety of materials important for quaternary geochronometry and archaeochronometry. We present a new luminescence dating method based on radioluminescence measurements of potassium feldspar. For the first time we have been able to investigate the light-emitting transition of electrons from the conduction band to an optically sensitive electron trap. Many advantages can be derived from such direct measurements of the metastable electron density in this particular trap, which produces the age-dependent signal. The method can be used to date the last light exposure of feldspar grains within a range of a few hundred to more than 200,000 years. Examples are presented of age determination of various waterlaid quaternary sands. The results of a basic study of feldspar radioluminescence also shed light on effects not sufficiently understood in conventional dating by luminescence techniques, especially in infrared optically stimulated luminescence dating of feldspar. [ABSTRACT FROM AUTHOR]

Lateral thickness modulations of epitaxial layers have been observed in symmetrically strained (GaIn)As/Ga(AsP) superlattices grown on misoriented (0 0 1) GaAs substrates by metallorganic vapour phase epitaxy. Systematic studies on the structural characteristics of the modulation as a function of the lattice mismatch of the individual layers and the misorientation of the substrates have been carried out by transmission electron microscopy (TEM) (cross-sectional and plan-view TEM, as well as high resolution TEM (HREM)). The modulation is periodic and anisotropic. The thickness maxima and minima of similar layers form a slab-like structure. The slabs are inclined from the growth direction and are parallel to the tilting axis of the misorientation of the substrates from (0 0 1), which is [1 1 0] where the misorientation is towards [1 1 0], and [1 0 0] where the misorientation is towards [0 1 0]. The onset of the modulation starts earlier during deposition in the case of higher mismatch strain. The modulation amplitudes increase as the deposition proceeds, and are larger when the mismatch strains are higher. The period of the modulation does not depend on the mismatch strain, and is larger when the width of the surface steps due to the misorientation is broader. The modulation is much less severe in (AlGaIn)As/Ga(AsP) strained layer superlattices. Surface migration of cations is considered to be the cause of redistribution of the equally spaced surface steps into step bunching, which leads to the thickness modulations. Also discussed are the roles of substrate misorientation, lattice mismatch and the cation species in the SLS. [ABSTRACT FROM AUTHOR]

We report the application of antisense RNA probes for in situ hybridization to identify collagen type I and type III mRNA synthesizing fibroblasts under in vitro and in vivo conditions in normal and wounded human skin. Non-specific hybridization was excluded by specific distribution patterns of α(I)-and α(III) probes in mouse fetuses. In addition, the specificity of hybridization was checked by sense probes, radioactively labelled transcripts of Gemini vectors and a keratin probe. In normal skin weakly activated fibroblasts were sparsely scattered within the dermis, while in wound healing processes mRNA both for α(I) and for α(III) was dramatically increased, thus suggesting that collagen synthesis is at least partly regulated at a pretranslational level. In addition, the intensity of the labelling, as defined by image analysis and the distribution pattern of collagen mRNA synthesizing cells, provide strong evidence that wound healing by primary intention starts within the deep dermis. [ABSTRACT FROM AUTHOR]

In this study, the use of a novel phosphorous precursor for low pressure metalorganic vapor phase epitaxy (LP-MOVPE) application has been investigated. Ditertiarybutyl phosphine ((CH)-P-H, DitBuPH) as substitute for the standardly used hydrid gas phosphine (PH) promises apart from strongly reduced toxicity due to the reduction of P-H bonds, an enhancement in cracking efficiency as well as a reduction in growth temperature. Layer quality has been examined by means of optical and scanning electron microscopy (SEM), temperature-dependent van der Pauw Hall as well as photoluminescence (PL) measurements. Uncompensated n-type InP-layers (1.0 x 1.5 cm; 59600 cmVs) at 77K) are realized using DitBuPH in combination with commercial TMIn. All results are compared with those obtained by using PH and commercial tertiarybutyl phosphine (TBP) as P-source, respectively. [ABSTRACT FROM AUTHOR]

In this work we investigate the lateral periodicity of symmetrically strained (GaIn)As/GaAs/Ga(PAs)/GaAs superlattices by means of X-ray scattering techniques. The multilayers were grown by metalorganic vapour phase epitaxy on (001)GaAs substrates, which were intentionally off-oriented towards the [011]-direction. The substrate off-oreintation and the strain distribution was found to affect the structural properties of the superlattices inducing the generation of laterally ordered macrosteps. Several high-resolution triple-crystal reciprocal space maps, which were recorded for different azimuth angles in the vicinity of the (004) Bragg diffraction and contour maps of the specular reflected beam collected in the vicinity of the (000) reciprocal lattice point, are reported and discussed. The reciprocal space maps clearly show a two-dimensional periodicity of the X-ray peak intensity distribution which can be ascribed to the superlattice periodicity in the direction of the surface normal and to a lateral periodicity in a crystallographic direction coinciding with the miscut orientation. The distribution and correlation of the vertical as well as of the lateral interface roughness was investigated by specular reflectivity and diffuse scattering measurements. Our results show that the morphology of the roughness is influenced by the off-orientation angle and can be described by a 2-dimensional waviness. [ABSTRACT FROM AUTHOR]

Femtosecond pulses of a collinearly pumped Optical Parametric Oscillator (OPO) are applied for investigations of the carrier dynamics in ternary and quaternary semiconductor quantum wells. The design and the specifications of the OPO are given in detail. We show that no measurable jitter exists between the pump pulses and the output pulses of the OPO. Therefore, it is possible to use the OPO and its pump laser for two-color experiments with a time resolution limited by the pulse lengths. We present and discuss results of transient four-wave mixing experiments on (InGa) As/InP quantum wells, and find a new kind of polarization-dependent quantum beat phenomenon. In addition, non-degenerate experiments on quantum wells from the quaternary (InGaAl) As material system, using two pulses at different wavelengths (one from the OPO and one from the pump laser), are discussed as a novel experimental technique to study carrier trapping into quantum wells. [ABSTRACT FROM AUTHOR]

Butylnitrosourea (BNU) was used to induce thymic lymphomas in BDF mice. During and after the 12-week BNU exposure the spontaneous NK cell activity against YAC-1 cells and that arising 4 days after stimulation with Corynebacterium parvum (CP) were measured, as were the mitogen responses of splenic T and B cells. In addition to BNU, groups of mice received multiple injections of the interferon inducer CP during or after the BNU exposure period. The results show a slight impairment of the NK cell activity by BNU and also after the injections of CP depending heavily on the treatment protocol. After the multiple injections of CP, either into BNU-treated mice or into controls, no further stimulation by CP was possible. The mitogen responses, reduced after BNU, were further reduced after the additional treatment. Both effects can be explained by the known induction of suppressor cells by CP. Although these treatments had pronounced effects on the parameters tested in vitro there was no significant influence on the development of thymic lymphomas in vivo. [ABSTRACT FROM AUTHOR]

Specific mRNA for α (I) collagen has been detected on a cellular level by in situ hybridization using radioactively labelled α (I) antisense RNA probes. We here present an automatic, quantitative, evaluation technique for the determination of grain densities using the high-resolution image analysis system IPS KONTRON. The reliability and objectivity of this method were evaluated by comparing the values of grains per cell obtained by conventional and automatic techniques following in situ hybridization with α (I) collagen DNA probes in various specimens. The correlation coefficients between conventional and automatic analysis of grain densities were 0.97 for fibroblasts embedded into a three-dimensional collagen gel, 0.94 for dermal fibroblasts in skin obtained from a patient with progressive systemic scleroderma, and 0.90 for fibroblasts in a 2-week-old scar. All correlation coefficients were significant on the P<0.0001 level. This new analysis technique therefore allows a more rapid and reliable quantitative evaluation of in situ hybridization and may also be helpful in differentiating between various cell populations characterized by different biosynthetic capacities. [ABSTRACT FROM AUTHOR]

Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i. e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values ( x) and standard deviations ( s) of the nuclear area ( x and s, p=0.00011), area of the nucleolus ( x, p=0.00043; s, p=0.00011), and area of the total cell ( x, p=0.00011; s, p=0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi. [ABSTRACT FROM AUTHOR]

In many cases of autoimmune blistering skin diseases indirect immunofluorescence with serum of patients on 1 M NaCl-separated skin represents a rapid diagnostic tool before the use of more complicated immunoelectron microscopy. The present study demonstrates that in skin samples from five adults, separated using 1 M NaCl, 0.15 M NaCl and 0.01 M phosphate buffered saline (PBS), the split formed within the lamina lucida at an identical ultrastructural level. The sub-basal dense plate (SDP) with a wreath of anchoring filaments remained on the epidermal side of the split adjacent to the hemidesmosomal part of the plasma membrane of basal keratinocytes. The base of the split blister was constituted from the lamina densa, with a remote possibility of some anchoring filaments attached. We demonstrate that antigens on the roof of the NaCl- or PBS-split blister may be associated, beside intracellular hemidesmosomal structures, with the SDP and basement membrane components between the SDP and the basal keratinocytes as well as with anchoring filaments attached to the SDP. The observations reported here allow a more precise mapping of antigen determinants in blistering skin diseases. [ABSTRACT FROM AUTHOR]

In order to investigate the temporal behavior of dynamic flow processes, a movie version of particle image velocimetry (PIV) with a high framing capability has been developed. The experimental setup includes a copper vapor laser capable to produce pulse sequences with more than 100 pulses with a repetition rate of up to 30 kHz and a rotating drum camera to record the Mie scattering signals from the particles seeded to the flow. With this setup, image sequences with a number of consecutive images (40-70 depending on the image size) of a dynamic process can be taken on high resolution 36 mm film. To evaluate the 2-dimensional velocity vector fields, an algorithm based on the crosscorrelation of subareas in consecutive images has been developed and optimized in terms of computing time. The technique was applied to resolve the instationary flow field in a single cylinder spark ignition (SI) engine during the compression stroke. [ABSTRACT FROM AUTHOR]

A PTA-technique for the in-plane determination of the three flow velocity vector components based on the defocused imaging of stray-particles has been investigated. The conventional setup for 2-D PTA has been modified by broadening the laser light-sheet to a width of approximately 1.5 mm and focusing the imaging optics in a plane in front of the laser light-sheet. Particles in the light-sheet are imaged out of focus and the image size of a particle therefore depends on its distance to the focal plane of the imaging optics. The increase of the particle image diameter within single particle tracks due to the defocusing was used to determine the velocity component perpendicular to the light-sheet. The results obtained with this technique in a well defined laminar air flow are in good agreement with LDV-data. [ABSTRACT FROM AUTHOR]

There are many methods by which values of the resonant frequencies of a system may be obtained. The purpose of this paper is to present one practical application of the Rayleigh-Ritz method. It is hoped that this will emphasize the versatility and relative accuracy of the energy procedure for vibration problems. The problem presented represents a high degree of complexity and, yet, solutions obtained exhibit a practical degree of accuracy as verified by experimental tests. [ABSTRACT FROM AUTHOR]

A new method for the determination of the velocity field with all three velocity components in a light sheet was demonstrated that combines conventional particle tracking anemometry (PTA) with an intensity analysis of the particle flecks. The correlation between intensity and the dimension perpendicular to the light sheet was obtained from the monotonous variation of the laser light intensity across the width of the light sheet. [ABSTRACT FROM AUTHOR]