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ZusammenfassungIn den letzten Jahren wurden bedeutsame Daten zur Biologie und Therapie des Riesenzelltumor des Knochens (RZTK) veröffentlicht. Ein entscheidender Durchbruch für die Diagnostik von RZTK war die Entdeckung der hoch tumorcharakteristischen Mutation im H3F3A-Gen, die zum Aminosäureaustausch G34W im Histon H3 führt. Zudem konnte sich in der Therapie die Behandlung von inoperablen RZTK mit dem anti-RANKL Antikörper Denosumab etablieren. Im Zusammenhang mit einer Denosumab-Therapie gibt es allerdings auch Berichte einer malignen Transformation des Tumors, wobei der konkrete Einfluss von Denosumab nicht eindeutig geklärt ist. Die Arbeitsgemeinschaft Knochentumoren (AGKT e. V.) hat daher eine multi-institutionelle Studie initiiert, um ein Kollektiv von RZTK zu etablieren mit dem Ziel a) morphologische Veränderungen unter Denosumab-Therapie detailliert zu beschreiben; b) Faktoren hinsichtlich einer potentiellen Malignisierung in ein Sarkom im Sinne einer Risikostratifizierung zu identifizieren; c) im direkten Vergleich RZTK im Rezidiv zu analysieren und mögliche Risikofaktoren hinsichtlich eines Rezidivs zu erarbeiten. Dafür wurden 26 RZTK vor und nach Denosumab-Therapie und 14 RZTK im Vergleich Primarius zu Rezidiv ohne Denosumab-Behandlung paarweise in die Studie eingeschlossen. Eingesetzte Techniken sind zunächst die histologische Beurteilung der morphologischen Veränderungen und die immunhistologische Analyse mittels eines breiten Panels an Markern. Das klinisch gut definierte Kollektiv soll im weiteren als Grundlage für eine Daten- und Gewebebank für zusätzliche molekularpathologische Analysen dienen.

Biopsy followed by histopathological assessment is the key procedure to establish the correct diagnosis of unclear bone or soft tissue tumors. There are several possibilities to obtain a biopsy specimen. The indication for biopsy should be established in a specialized center, as should the type of biopsy (fine needle, incisional, excisional, percutaneous CT-guided/navigated biopsy), which must be performed according to established guidelines. The tumor biopsy must be representative and adequate in terms of quantity, to enable a conclusive histopathological diagnosis and planning of appropriate treatment. For the correct biopsy tract, the surgical approach for definitive resection must be considered; thus, biopsy should be conducted in the center where the subsequent resection will be performed. Of note, patients whose biopsy is performed at a specialized musculoskeletal tumor center benefit in terms of improved local tumor control.

Tumourous destruction of the periacetabular region and the proximal femur is a typical consequence of either primary malignant bone tumour manifestation or skeletal metastatic diseases. Pathological fractures of the proximal femur and periacetabular regions due to primary manifestation or metastatic disorders are frequent.Presentation of the most common complications of tumour endoprostheses at the hip and a description of management strategies, including therapeutic recommendations and concepts for complication avoidance.The current knowledge and our own experience of complication management with the use of megaprostheses around the hip are presented.Compared to elective/primary total hip arthroplasty, megaprosthetic reconstructions following tumour resections have an increased rate of postoperative deep infections, dislocations, incidence of pathological and periprosthetic fractures and of deep vein thrombosis. The postoperative mortality and local tumour recurrence along with deep infections represent the most serious complications.In comparison to primary arthroplasty, the risk of failure and complications following tumour-endoprosthetic replacement is increased. Precise surgical planning and careful selection and preoperative preparation of suitable patients should be performed in close interdisciplinary cooperation with final decision-making on an interdisciplinary tumour board. Wide resection and advanced reconstruction, as well as complicated palliative stabilization due to malignant bone tumour growth around the hip joint should be performed in musculoskeletal tumour centres with profound expertise in osteosynthetic and endoprosthetic reconstruction and consecutive complication management of the pelvis and the proximal femur.

Tritium betavoltaics are one of the family of nuclear batteries which convert natural radioactive decay from a radioisotope into electricity that can provide continuous power without the requirement for replacement or recharging. Tritium is ideally suited to this application due to its high specific activity, low shielding requirements and relatively high availability. Owing to safety and environmental concerns over tritium leakage, metal tritides films are preferred as tritium betavoltaic sources. Titanium hydride and deuteride films were studied as analogues to titanium tritide films. The quality of the films depended on the temperature of hydrogen loading as films loaded at elevated temperatures (>100 °C) were brittle and delaminated from the semiconductor substrate while those exposed to hydrogen at room temperature continued to adhere to the substrate. For the latter films, evidence of hydrogen isotope loss was observed when left under ambient conditions over the course of a few weeks.

Tumor endoprostheses are available as modular systems with which bone defects can be partially reconstructed, usually close to the joints, or as a total replacement of long tubular bones. As a result of continuously improved survival times, they are used with bone tumors, skeletal metastases and, increasingly, in revision arthroplasty.Presentation of the most common complications of tumor endoprostheses and a description of their management, including treatment recommendations.The current knowledge and our own experience of complication management with the use of megaprostheses are presented.The number of tumor endoprostheses procedures is limited, so that a limited number of studies and classifications are available. Periprosthetic infections involving the soft tissues represent the most serious failure after perioperative dying and local recurrence of the tumor. Two-stage revision remains the gold standard in periprosthetic infection, even if one-stage revision is justifiable in selective indications. Periprosthetic infection and local recurrence is associated with the risk of secondary amputations. Mechanical failure can be treated more easily. Specific socket systems for proximal femoral replacement and attachment tubing allow for adequate soft tissue reconstruction, restoration of joint function, and minimize the risk of dislocation.In comparison to primary arthroplasty, the risk of failure following tumor endoprosthetic replacement is increased but is basically controllable by revision surgery.

This manuscript presents the design and utilisation of a unique environmental chamber allowing specimens to be heated and cooled, under tensile load and controlled atmosphere, while in a neutron beam, offering a unique opportunity for in-situ neutron diffraction experiments. The chamber was built to gain insight into the impact of parameters such as tensile stress, temperature and exposed atmosphere on the hydrogen solubility of materials and on the mechanisms relating to delayed hydride cracking, hydrogen embrittlement and hydrogen ingress. The investigation presented in this work shows the chamber's performance up to 450°C and 275 MPa applied tensile stress. The effect of tensile stresses and temperature on hydrogen solubility in Zr-2.5Nb is presented for samples nominally charged to hydrogen concentration equivalents of 200 and 500 wppm (mg/kg). Due to kinetic factors, no significant effect of tensile stress on the hydrogen solubility of our samples was found for temperatures up to 300°C and at tensile stresses up to 275 MPa.

Fus und Sprunggelenksregion sind eine seltene Lokalisation muskuloskelettaler Tumoren. Das Spektrum umfasst benigne, lokal aggressive und maligne Knochen- und Weichteiltumoren. Grosere klinische Studien sind daher rar. Klinische Erstmanifestationen sind v. a. unspezifische Schwellungen und Schmerzen. Pathologische Frakturen als Erstsymptom sind nicht selten. Die onkologische Diagnostik und Therapie erfolgt interdisziplinar. Das onkochirurgische Spektrum reicht von palliativen Stabilisierungen, intralasionalen Verfahren bei benignen Tumoren oder tumorahnlichen Lasionen zu radikalen weiten Resektionen bei lokal aggressiven oder High-grade-Tumoren. Extremitatenerhaltende Eingriffe sind infolge der komplexen Anatomie etwas geringer als bei anderen Extremitatenlokalisationen. Unspezifische Klinik, geringe Inzidenz und komplexe Anatomie machen sowohl die Exzision von Tumoren am Fus als auch die ossare/plastische Defektrekonstruktion zu einer therapeutischen Herausforderung.

The magnetic structure of the in-plane skyrmions in epitaxial MnSi/Si(111) thin films is probed in three dimensions by the combination of polarized neutron reflectometry (PNR) and small angle neutron scattering (SANS). We demonstrate that skyrmions exist in a region of the phase diagram above at temperature of 10 K. PNR shows the skyrmions are confined to the middle of the film due to the potential well formed by the surface twists. However, SANS shows that there is considerable disorder within the plane indicating that the magnetic structure is a 2D skyrmion glass.

Benign bone lesions are much more common than malignant lesions. Some benign bone tumors have a characteristic and typical radiographic appearance, while others are more challenging. Therapy of benign bone tumors differs greatly. While the majority of benign bone tumors do not require surgical therapy, other specific lesions, e. g. aneurysmal bone cysts or giant cell tumors (GCT) of the bone require surgery due to their locally aggressive behavior.The major challenge for the radiologist and/or pathologist is the differentiation between a benign and low-grade malignant lesion (e. g. enchondroma versus low-grade chondrosarcoma) for which all available clinical and radiographic information is mandatory. Therefore, surgical therapy is rather more often performed than necessary due to uncertainty in many cases.Novel systemic therapies are available for fibrous dysplasia and GCT of the bone: Fibrous dysplasia can be treated with bisphosphonates, and GCT responds to denosumab. In fact, denosumab has been approved for the treatment of irresectable GCT. Osteoid osteoma is fairly easy to recognize and also to treat given the characteristic clinical presentation and rapid and effective response to local therapy (possible as percutaneous thermo-/laser ablation). In summary, several therapeutic options exist for benign bone tumors, and the choice depends upon the tendency/risk of local recurrence, the rate of surgical complications, options for defect reconstruction, postoperative functional deficits, and specific patient characteristics.

Purpose: The aim of this study was to characterize and understand the therapy-induced changes in diffusion parameters in rectal carcinoma under chemoradiotherapy (CRT). The current literature shows conflicting results in this regard. We applied the intravoxel incoherent motion model, which allows for the differentiation between diffusion (D) and perfusion (f) effects, to further elucidate potential underlying causes for these divergent reports. Materials and methods: Eighteen patients with primary rectal carcinoma undergoing preoperative CRT were examined before, during, and after neoadjuvant CRT using diffusion-weighted imaging. Using the intravoxel incoherent motion approach, f and D were extracted and compared with postoperative tumor downstaging and volume. Results: Initial diffusion-derived parameters were within a narrow range (D1 = 0.94 ± 0.12 × 10−3 mm2/s). At follow-up, D rose significantly (D2 = 1.18 ± 0.13 × 10−3 mm2/s; P

Purpose The clinical potential of the diffusion imaging-based analysis of fine brain structures such as fornix or cingulum is high due to the central role of these structures in psychiatric diseases. However, the quantification of diffusion parameters in fine structures is especially prone to partial volume effects (PVEs). Methods In this study, a phantom for the investigation of PVEs and their influence on diffusion parameters in fine structures of different diameter is presented. The phantom is produced by winding wet polyester fibers onto a spindle. The resulting fiber strands have well defined square cross-sections of 1–25 mm2 and provide a homogeneous and high fractional anisotropy (FA ≈ 0.9). Results Several PVEs are demonstrated and analyzed. It is shown that inferred results such as the fiber geometry and diffusion parameters strongly depend on the relative position of the structure of interest to the voxel-grid. Several implications of PVEs on post-processing methods such as Tract-based Spatial Statistics and fiber tractography are demonstrated. Conclusion These results show that the handling of PVEs in common post-processing tasks can be problematic, and that the presented phantom provides a valuable tool for the improvement and evaluation of these effects. Magn Reson Med 71:1108–1116, 2014. © 2013 Wiley Periodicals, Inc.

Diffusion-weighted imaging (DWI) can be used to quantitatively assess functional parameters in rectal carcinoma that are relevant for prognosis and treatment response assessment. However, there is no consensus on the histopathological background underlying the findings derived from DWI. The aim of this study was to perform a comparison of DWI and histologic parameters in two groups of rectal carcinoma patients without (n=12) and after (n=9) neoadjuvant chemoradiotherapy (CRT). The intravoxel incoherent motion (IVIM) model was used to calculate the diffusion coefficient D and the perfusion fraction f in rectal carcinoma, the adjacent rectum and fat in the two patient groups. Immunohistological analysis was performed to assess the cellularity, vascular area fraction and vessel diameter for comparison and correlation. Out of 36 correlations between parameters from DWI and histology, four were found to be significant. In rectal carcinoma of patients without CRT, the diffusion D and the perfusion f correlated with the vascular area fraction, respectively, which could not be found in the group of patients who received CRT. Further correlations were found for the rectum and fat. Histological evaluation revealed significant differences between the tissues on the microscopic level concerning the cellular and vascular environment that influence diffusion and perfusion. In conclusion, DWI produces valuable biomarkers for diffusion and perfusion in rectal carcinoma and adjacent tissues that are highly dependent of the underlying cellular microenvironment influenced by structural and functional changes as well as the administered treatment, and consequently can be beyond histological ascertainability.

The apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging (DWI) correlates inversely with tumor proliferation rates. High-grade gliomas are typically heterogeneous and the delineation of areas of high and low proliferation is impeded by partial volume effects and blurred borders. Commonly used manual delineation is further impeded by potential overlap with cerebrospinal fluid and necrosis. Here we present an algorithm to reproducibly delineate and probabilistically quantify the ADC in areas of high and low proliferation in heterogeneous gliomas, resulting in a reproducible quantification in regions of tissue inhomogeneity. We used an expectation maximization (EM) clustering algorithm, applied on a Gaussian mixture model, consisting of pure superpositions of Gaussian distributions. Soundness and reproducibility of this approach were evaluated in 10 patients with glioma. High- and low-proliferating areas found using the clustering correspond well with conservative regions of interest drawn using all available imaging data. Systematic placement of model initialization seeds shows good reproducibility of the method. Moreover, we illustrate an automatic initialization approach that completely removes user-induced variability. In conclusion, we present a rapid, reproducible and automatic method to separate and quantify heterogeneous regions in gliomas.

SummaryBackground: Diffusion-MRI provides a unique window on brain anatomy and insights into aspects of tissue structure in living humans that could not be studied previously. There is a major effort in this rapidly evolving field of research to develop the algorithmic tools necessary to cope with the complexity of the datasets.Objectives: This work illustrates our strategy that encompasses the development of a modularized and open software tool for data processing, visualization and interactive exploration in diffusion imaging research and aims at reinforcing sustainable evaluation and progress in the field.Methods: In this paper, the usability and capabilities of a new application and toolkit component of the Medical Imaging and Interaction Toolkit (MITK, www.mitk.org), MITKDI, are demonstrated using in-vivo datasets.Results: MITK-DI provides a comprehensive software framework for high-performance data processing, analysis and interactive data exploration, which is designed in a modular, extensible fashion (using CTK) and in adherence to widely accepted coding standards (e.g. ITK, VTK). MITK-DI is available both as an open source software development toolkit and as a ready-to-use in stallable application.Conclusions: The open source release of the modular MITK-DI tools will increase verifiability and comparability within the research community and will also be an important step towards bringing many of the current techniques towards clinical application.

Purpose: Computed tomography (CT) guided minimally invasive interventions such as biopsies or ablation therapies often involve insertion of a needle-shaped instrument into the target organ (e.g., the liver). Today, these interventions still require manual planning of a suitable trajectory to the target (e.g., the tumor) based on the slice data provided by the imaging modality. However, taking into account the critical structures and other parameters crucial to the success of the intervention—such as instrument shape and penetration angle—is challenging and requires a lot of experience. Methods: To overcome these problems, we present a system for the automatic or semiautomatic planning of optimal trajectories to a target, based on 3D reconstructions of all relevant structures. The system determines possible insertion zones based on so-calledhard constraints and rates the quality of these zones by so-called soft constraints. The concept of pareto optimality is utilized to allow for a weight-independent proposal of insertion trajectories. In order to demonstrate the benefits of our method, automatic trajectory planning was applied retrospectively to n = 10 data sets from interventions in which complications occurred. Results: The efficient (graphics processing unit-based) implementation of the constraints results in a mean overall planning time of about 9 s. The examined trajectories, originally chosen by the physician, have been rated as follows: in six cases, the insertion point was labeled invalid by the planning system. For two cases, the system would have proposed points with a better rating according to thesoft constraints. For the remaining two cases the system would have indicated poor rating with respect to one of the soft constraints. The paths proposed by our system were rated feasible and qualitatively good by experienced interventional radiologists. Conclusions: The proposed computer-assisted trajectory planning system is able to detect unsafe and propose safe insertion trajectories and may especially be helpful for interventional radiologist at the beginning or during their interventional training.

In this article, we show how neutron reflectometry (NR) can provide deep insight into the absorption and desorption properties of commercially promising hydrogen storage materials. NR benefits from the large negative scattering length of hydrogen atoms, which changes the reflectivity curve substantially, so that NR can determine not only the total amount of stored hydrogen but also the hydrogen distribution along the film normal, with nanometer resolution. To use NR, the samples must have smooth surfaces, and the film thickness should range between 10 and 200 nm. We performed a systematic study on thin Mg1–xAlx alloy films (x = 0.2, 0.3, 0.4, 0.67) capped with a Pd catalyst layer. Our NR experiments showed that Mg0.7Al0.3 is the optimum alloy composition with the highest amount of stored hydrogen and the lowest desorption temperature. All the thin films expand by about 20% because of hydrogen absorption, and the hydrogen is stored only in the MgAl layer with no hydrogen content in the Pd layer.

For the validation of complex diffusion imaging techniques like q-ball imaging that aim to resolve multiple fiber directions, appropriate phantoms are highly desirable. However, previous q-ball imaging phantoms had diffusion anisotropies well below those of in vivo white matter. In this work, fiber phantoms of well-defined geometry are presented. The fibers are wound on a spherical spindle yielding high packing densities and consequently high diffusion anisotropies (fractional anisotropy 0.93 ± 0.02 at b = 500 s/mm2). Phantoms with 90° and 45° crossing angle were constructed both with two crossing types. In the “stacked” crossing, two fiber strings were wound consecutively to simulate two touching fibers, in the “interleaved” crossing, fibers were wound alternately. The stacked crossing allows the alteration of partial volumes, whereas the interleaved crossing provides constant partial volumes, allowing e.g. the easy alteration of the SNR by varying the slice thickness. Exemplary q-ball imaging validation measurements using different b-values and slice thicknesses are presented. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc.

Zusammenfassung Die physikalischen Prinzipien der bisher bekannten Methoden der rontgenologisch-photometrischen Bestimmung des Aschegehaltes im Knochen werden dargelegt. In Anlehnung an die Untersuchungen von Heuck und Schmidt (1960), die das vorliegende Problem fur die Humanmedizin grundlegend bearbeitet haben, fand bei unseren Versuchen die quantitative Vergleichsmethode mit photometrischer Auswertung Anwendung. Der von uns hergestellte Vergleichskorper besteht aus Piacryl, in das aus Rinderknochenspongiosa gewonnene Knochenasche homogen einpolymerisiert ist. Die Methodik der Rontgenaufnahme des 7. Schwanzwirbelknochens, der gleichzeitig mit dem Vergleichskorper in einem Wasserbad gerontgt wird, sowie die photooptische Registrierung und photometrische Auswertung der Rontgenfilme erfahren eine ausfuhrliche Beschreibung. Die von 29 klinisch gesunden Jungbullen rontgenologisch-photometrisch ermittelten Aschewerte der proximalen Diaphyse des 7. Schwanzwirbels liegen zwischen 222 und 385 mg/cm3. Die gefundenen Einzelwerte sind statistisch bearbeitet. Ein Vergleich der rontgenologisch-photometrisch erhaltenen Werte des Aschegehaltes in der Volumeneinheit Knochengewebe mit denen der chemisch-analytischen Untersuchung ergibt eine maximale Abweichung von ±12,6%. Summary A method of determining the ash content of cattle bones by X-ray photometry The physical principles of the known methods for determining the content of bone by x-ray photometry are described. The authors used quantitative methods like those investigated extensively by Heuck and Schmidt, 1960, in human medicine. The standard wedge was constructed from the plastic piacryl in which cattle bone ash was incorporated by polymerization. Radiographs were taken of the seventh caudal vertebra, with the standard wedge alongside it, both in a container of water. The ash values of the proximal diaphysis of the seventh caudal vertebra of 29 clinically healthy young bulls ranged from 222 to 385 mg./cc. The values were examined statistically. Comparison of the values obtained by X-ray photometry with those obtained by the usual methods of chemical analysis gave a maximal difference of ±12.6%. Resume Le dosage de la teneur en cendres des os du Boeuf par photometrie radiologique Les auteurs exposent les principes physiques des methodes deja connues pour determiner la teneur en cendres des os par photometrie radiologique. A la suite des recherches de Heuck et Schmidt (1960) qui ont resolu ce probleme en medecine humaine, les auteurs ont utilise une methode de comparaison quantitative avec etude photometrique. Le corps de comparaison fabrique a cet effet se compose de piacryl dans lequel on a incorpore par polymerisation des cendres d'os obtenues a partir de tissu spongieux de squelette bovin. On donne une description detaillee de la methode d'examen radiographique de la 7e vertebre caudale radiographiee en meme temps que le corps de comparaison dans un bain d'eau, ainsi que l'enregistrement photo-optique et l'interpretation photometrique des films radiographiques. Les taux trouves pour 29 taurillons cliniquement sains obtenus par cette methode dans la diaphyse proximale de la 7e vertebre caudale varient entre 222 et 385 mg/cm3. Les valeurs trouvees ont ete soumises a une etude statistique. Une comparaison des valeurs obtenues pour la teneur en cendres par unite de volume de tissu osseux avec ceux de l'analyse chimique donne une difference maximale de ±12,6%. Resumen Tecnica de la determinacion roentgenologico-fotometrica del contenido en ceniza de los huesos de bovidos Se exponen los fundamentos fisicos de las tecnicas conocidas hasta la fecha de la determinacion roentgenologico-fotometrica del contenido en ceniza de los huesos. Inspirados en los trabajos de Heuck y Schmidt (1960), los cuales agotaron de forma primordial el presente problema en medicina humana, en nuestros ensayos aplicamos la tecnica comparativa cuantitativa con valoracion fotometrica. El cuerpo comparativo preparado por nosotros es de piacrylo, dentro del cual se ha polimerizado homogeneamente ceniza osea obtenida de la parte esponjosa de huesos de bovidos. A una descripcion detalladisima se someten la tecnica radiografica de la 7a vertebra coccigea, la cual se impresiona al mismo tiempo que el cuerpo comparativo en un bano maria, asi como el registro fotooptico y la valoracion fotometrica de las peliculas Roentgen. Los valores de ceniza de la diafisis proximal de la 7a vertebra coccigea, determinados de forma roentgenologico-fotometrica en 29 toros jovenes clinicamente sanos, oscilaban entre 222 y 385 mg/cm3. Los valores aislados hallados se han elaborado estadisticamente. La comparacion de los valores del contenido en ceniza en la unidad de volumen de tejido oseo, obtenidos roentgenologico-fotometricamente, con los del examen quimico-analitico ofrece una desviacion maxima de ±12,6%.

Using unpolarized neutron diffraction the magnetic structure of 30 nm thick Cr(1 1 0) films of a V/Cr multilayer was investigated in a horizontal field of 2.6 T and a vertical field of 7.5 T at a temperature of 270 and 2 K. The horizontal field was applied parallel to the [0 1 0] and [1 0 0] direction, whereas the vertical field was applied along the [ 1 1 ¯ 0 ] direction. In bulk chromium, a field of 2 T parallel to the Cr polarization leads to a rotation of the polarization perpendicular to the applied field. In contrast, our experiments on thin Cr(1 1 0) films show no change of the magnetic structure in a magnetic field up to 7.5 T. A comparison of these measurements to earlier experiments on Fe / Cr ( 1 1 0 ) multilayers where the Cr polarization could be rotated easily by rotating the Fe magnetization proves the huge exchange coupling present at the Fe/Cr interface.

Interaction between oocyte and follicle cells, cumulus oophorus and theca cells is the subject of research. Based both on fundamental research and first clinical experience, the role of cumulus cells for the oocyte within the framework of IVF/ICSI treatment is discussed. The connection between cumulus cells and oocytes via gap junctions makes the bidirectional exchange of chemical messengers possible. This exchange, in turn, contributes to the optimal development of the oocytes. FSH, LH and EGF as chemical messengers play an important role with regard to the development of oocytes. Furthermore, the cumulus-oocyte complex produces chemical messengers which attract sperm. The extent to which both the apoptosis of cumulus cells and the anti Mullerian hormone can be used as predictive factors for ART is discussed. The role that GnRH, FSH, LH and estradiol (E2) play in oocyte maturation within the framework of the cumulus-oocyte complex is described. FSH and LH are important factors for folliculogenesis and oogenesis. Threshold effects appear to exist for FSH and LH which affect oocyte quality and ultimately also pregnancy rate. The retrospective subanalysis of a comparative trial with hMG-HP vs. rFSH in GnRH agonist downregulated ovarian stimulation cycles showed that the hMG-HP stimulated cycles led to a significantly higher pregnancy rate among IVF patients than did those with rFSH. Further prospective randomized studies must now clarify whether, as a result of cumulus-oocyte communication, IVF patients profit more from hMG-HP stimulation than from rFSH with respect to pregnancy rate.

We observed a complete suppression of the incommensurate spin-density wave in thin Cr layers of a V/Cr multilayer in a temperature range from 550 K down to 2 K. The (110)-oriented V/Cr multilayer consisting of 30 nm thick Cr layers and 5 nm thick V layers was investigated by neutron and X-ray diffraction (XRD). From the XRD experiments we were able to determine that the epitaxial strain of the Cr layers in the V/Cr multilayer is about 90% larger than in earlier studied Fe/Cr(110) multilayers. That leads to a completely different magnetic phase diagram as revealed by neutron diffraction experiments. The existence of the commensurate antiferromagnetic structure in the Cr layers can be observed in the whole temperature range without a phase transition to an incommensurate spin-density wave at lower temperatures. In order to elucidate the proximity effects further we also performed experiments in an external magnetic field. Up to a field of 4 T we found no change in the magnetic structure of the Cr films whereas in earlier experiments on Fe/Cr(110) multilayers we could observe a strong perpendicular pinning of the Cr polarization to the Fe magnetization.

Einleitung. Dem axillaren Lymphknotenstatus kommt beim Mammakarzinom aufgrund seiner prognostischen Bedeutung ein besonderer Stellenwert zu. Eine Aufgabe dieser Studie war es, die Durchfuhrbarkeit und Verlasslichkeit der "Sentinel Node Biopsy" (SNB) im klinischen Alltag aufzuzeigen, eine weitere die Uberprufung dieses Konzeptes auch bei Patienten nach praoperativer Chemotherapie (PC) und bei multizentrischen Tumoren (MC).

We studied the off-specular intensity in polarized neutron reflectivity from regular arrays of circular and rectangular Co dots with sizes in the micrometer range. The dots were lithographically prepared and placed on a square lattice with a period of 10 μm, the rectangular dots having an aspect ratio of 4:1. In both cases, we observed enhanced intensity at particular angles off the specular condition. The positions of these satellites are correlated to the lateral periodicity of the ferromagnetic dots. The magnetic information could be revealed by measuring the off-specular intensity as a function of the magnetic field applied in-plane parallel to the rows of the dots. The magnetization reversal process could be analyzed by separating the spin-flip and non-spin-flip contributions to the off-specular signal. The measured spin-flip intensities clearly prove that for both samples the magnetization reversal is dominated by domain wall movement and not by a uniform rotation of single-domain particles.

The interaction of short nucleotide duplexes with bis-netropsins, in which netropsin fragments are linked in the tail-to-tail orientation via cis-diammineplatinum group ( ) or aliphatic pentamethylene chain ( ), has been studied. Both the bis-netropsins have been shown to bind to DNA oligomer 5'-CCTATATCC-3' (I) as a hairpin with parallel orientation of netropsin fragments in 1:1 stoichiometry. Monodentate binding has been detected upon binding of bis-netropsins to other duplexes of sequences 5'-CCXCC-3'--where X = TTATT (II), TTAAT (III), TTTTT (IV), and AATTT (V)--along with the binding of bis-netropsins as a hairpin. The formation of dimeric antiparallel motif between the halves of two bound bis-netropsin molecules has been observed in the complexes of with DNA oligomers IV and V. The ratio of binding constant of bis-netropsin as a hairpin (K2) to monodentate binding constant (K1) has been shown to correlate with the width and/or conformational lability of DNA in the binding site. The share of bis-netropsin bound as a hairpin decreases in the order: TATAT > TTATT > TTAAT > TTTTT > AATTT, whereas the contribution of monodentate binding rises. The minimal strong binding site for and binding as a hairpin has been found to be DNA duplex 5'-CGTATACG-3'.

Thin epitaxial W(1 1 0)/Co and Au(1 1 1)/Co films were prepared by molecular beam epitaxy on single crystal sapphire Al 2 O 3 (1 1 2 0) substrates and investigated by means of low energy electron diffraction and Auger electron spectroscopy. The growth of W on Al 2 O 3 (1 1 2 0) was found to depend strongly on substrate temperature and film thickness. W films deposited at a substrate temperature T p =1200 K with a film thickness d W ⩾100 A revealed a bcc(1 1 0) structure with a mean terrace size of 40 A. Epitaxial growth of Au was achieved at T p =300 K with a layer thickness d Au =30 A for a deposition onto the W(1 1 0) substrate layers. The structural properties of thin Co films grown at T p =300 K on the W(1 1 0) and Au(1 1 1) substrate layers were studied as a function of Co film thickness for wedge-shaped layers. The Co films were found to grow epitaxially in both cases with distinct growth modes and lattice strains.

Obwohl die donogene Insemination (DI) eine effektive Methode zur Erfullung des Kindeswunsches bei Infertilitat des Mannes ist, geniest sie kein groses Ansehen. Vorbehalte entstehen bereits, indem das Recht auf eigene Kinder infrage gestellt wird. Es ist erforderlich, ein besseres Verstandnis fur die Sterilitat als Storung von Krankheitswert zu entwickeln. Bei Infertilitat des Ehemannes entsteht eine einschneidende Lebenskrise mit Stigmatisation des Mannes. Auser der Adoption eines Kindes kann eine donogene Insemination hilfreich sein, aber Behauptungen von einer Gefahrdung des Familiengluckes und des Kindeswohls verunsichern manche Gynakologen und viele sterile Ehepaare. Diese Postulate werden diskutiert. Befragungen der selbst behandelten Patientenehepaare und Publikationen der meisten Reproduktionsmediziner widerlegen die moralisch uberheblichen Behauptungen vom gefahrdeten Familiengluck nach donogener Insemination.

Recently we created La/Fe multilayers with a helical magnetic structure imprinted from the conditions of growth rather than by the magnetic interactions between layers. Each sublayer was 30 A thick, and during deposition the sample was rotated in an external field of 3 Oe, a field strong enough to magnetize the Fe layer being deposited but not sufficient to perturb the magnetization of the Fe layers already grown. As a result adjacent Fe layers formed a helical structure with a chirality and periodicity determined by the rotational direction and speed of the substrate and the rate of deposition. Following this discovery an extensive set of experiments (mainly using Kerr effect magnetometry and polarized neutron reflectivity) was undertaken to ascertain the stability of imprinted magnetic structures, and to understand the onset of magnetization during growth. La/Fe imprinted helical magnetic structures (of different La and Fe thicknesses) were found to be stable in time and to be permanently erased only by...