Buchbesprechung: Oskar Cullmann, Unsterblichkeit der Seele oder Auferstehung der Toten? Stuttgart, 2. Aufl. 1962

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Seebeck coefficients of half-metallic ferromagnets

In this report the Co2 based Heusler compounds are discussed as potential materials for spin voltage generation. The compounds were synthesized by arcmelting and consequent annealing. Band structure calculations were performed and revealed the compounds to be half-metallic ferromagnets. Magnetometry was performed on the samples and the Curie temperatures and the magnetic moments were determined. The Seebeck coefficients were measured from low to ambient temperatures for all compounds. For selected compounds high temperature measurements up to 900 K were performed.Comment: accepted contribution o the Special Issue "Spin Caloritronics" of Solid State Communication

Bulk sensitive photo emission spectroscopy of C1b compounds

This work reports about bulk-sensitive, high energy photoelectron spectroscopy from the valence band of CoTiSb excited by photons from 1.2 to 5 keV energy. The high energy photoelectron spectra were taken at the KMC-1 high energy beamline of BESSY II employing the recently developed Phoibos 225 HV analyser. The measurements show a good agreement to calculations of the electronic structure using the LDA scheme. It is shown that the high energy spectra reveal the bulk electronic structure better compared to low energy XPS spectra.Comment: J. Electron Spectrosc. Relat. Phenom. accepte

Endovascular Treatment of Anterior Circulation Cerebral Aneurysms by Using Guglielmi Detachable Coils: A 10-Year Single-Center Experience with Special Emphasis on the Use of Three-Dimensional GDC

Purpose:: To analyze the immediate, long-term angiographic and clinical results of endovascular treatment of anterior circulation aneurysms with special regard to the use of three-dimensional Guglielmi detachable coils (3D-GDC). Patients and Methods:: Between 1993 and 2003, 116 patients with 116 anterior circulation aneurysms were treated. 88 patients (75.9%) underwent embolization due to high surgical risk. To analyze the use of 3D-GDC, patients treated before (group 1) and after (group 2) implementation of 3D-GDC in 1999 were compared. Mean duration of angiographic follow-up was 13.9 months. Clinical follow-up was set at hospital discharge and using a questionnaire for long-term follow-up (mean 46.8 months). Results:: Overall, at initial intervention, complete occlusion was achieved in 65 aneurysms (56.0%), neck remnant in 42 (36.2%), and incomplete occlusion in nine (7.8%). Procedure-related permanent morbidity was 4.3% and mortality 2.6%. Recanalization rate at radiologic follow-up was 16.7%. Occlusion success at initial treatment correlated with aneurysm neck size (p = 0.001). Clinical outcome at hospital discharge was dependent on Hunt & Hess grade at presentation (p = 0.01). Subgroup analysis revealed that the use of 3D-GDC produced a higher initial obliteration rate compared to standard coils, but did not reach statistical significance (p = 0.059). Neither aneurysm neck size nor aneurysm dome size nor the use of 3D-GDC significantly influenced recanalization rate. Conclusion:: GDC technology is effective and safe, particularly in case of patients with high surgical risk. Aneurysm neck size was predictive of occlusion rate and Hunt & Hess grade of clinical outcome. Introduction of 3D-GDC probably improved occlusion rate, but did not significantly influence recanalization rat

UNILAC Upgrades for Coulomb Barrier Energy Experiments

The GSI linear accelerator UNILAC provides heavy ion beams at Coulomb barrier energies for search and study of super heavy elements. Typical cross-sections of 55 fb require beam doses of 1.4·10¹⁹ according to a beam time of 117 days. Several upgrades will reduce the beam time to only 16 days. A second injection branch with a 28GHz-MS-ECRIS anticipates a factor of 10 in particle intensity. By a new cw rfq-structure all accelerator tanks are suitable for a duty cycle of at least 50% instead of 25% presently. Due to this, thermal power increase of 19 rf-amplifiers eased by higher ion charge states of the ECRIS is necessary. Finally the UNILAC timing system controlling 50Hz pulse-to-pulse operation of up to six beams differing in ion species and energy has to be modified considering beam diagnostics electronics and pulsable magnets. The front end comprising ECRIS, rfq- and IH-structure is cw suitable and will serve as injector for a new future sc-cw-linac

Endovascular and surgical treatment of spinal dural arteriovenous fistulas

Introduction: The aim of this retrospective study was to evaluate the clinical outcome of patients with spinal dural arteriovenous fistulas (SDAVFs) that were treated with surgery, catheter embolization, or surgery after incomplete embolization. Methods: The study included 21 consecutive patients with SDAVFs of the thoracic, lumbar, or sacral spine who were treated in our institution from 1994 to 2007. Thirteen patients were treated with catheter embolization alone. Four patients underwent hemilaminectomy and intradural interruption of the fistula. Four patients were treated by endovascular techniques followed by surgery. The clinical outcome was assessed using the modified Aminoff-Logue scale (ALS) for myelopathy and the modified Rankin scale (MRS) for general quality of life. Patient age ranged from 44 to 77years (mean 64.7years). Results: Surgical as well as endovascular treatment resulted in a significant improvement in ALS (−62.5% and −31.4%, respectively, p < 0.05) and a tendency toward improved MRS (−50% and −32%, respectively) scores. Patients that underwent surgery after endovascular treatment due to incomplete occlusion of the fistula showed only a tendency for improvement in the ALS score (−16.7%), whereas the MRS score was not affected. Conclusion: We conclude that both endovascular and surgical treatment of SDAVFs resulted in a good and lasting clinical outcome in the majority of cases. In specific situations, when a secondary neurosurgical approach was required after endovascular treatment to achieve complete occlusion of the SDAVF, the clinical outcome was rather poor. The best first line treatment modality for each individual patient should be determined by an interdisciplinary tea