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Reaction of 1,1-dichloro-2,5-diphenylcyclopropabenzene 6 with Meldrum's acid 8 in the presence of pyridine leads to coupling of the cycloproparenyl cation 7 with the stabilized diketo anion 9. Subsequent, spontaneous, base-induced dehydrochlorination gives the alkylidenecyclopropabenzene 11 in a one-pot reaction. Flash vacuum thermolysis of 11 at 650 °C ejects acetone and carbon dioxide, giving cyclopropabenzenylidenethenone 12 that is isolated in an Ar matrix at 20 K and characterized by a strong ketene band at 2107 cm^-1 in the IR spectrum.

Abstract: The haul-out and underwater activity patterns of five Weddell seals were investigated in relation to the tide. Electronic recorders measured the seals' dive depth and internal body temperature simultaneously. Diving and temperature data were analysed with the help of time series analyses tools. We identified a half-day (semicircadian) rhythm in underwater activity and body temperature. A close correlation was found between the rhythmicity of the tide and the timing of the seals' underwater activity and oscillations of their body temperature. We propose that the tide is the principal zeitgeber for the Weddell seals' ultradian cycle of behaviour during the austral summer.

Bulk Y1Ba2Cu3Oywas melt-textured without the use of seed crystals as well as by applying top-seeding with different seeds resulting in different orientations of the c-axis. Samples were examined by elastic neutron scattering and levitation force. The levitation force of the samples strongly depends on the orientation of the c-axis. The local superconducting parameters were found to be reduced with increasing distance from the seed. In order to study this influence, two cubes were prepared by top-seeding, but with seeds of Nd123 that had a parallel and perpendicular orientation of the c-axis of the Nd123-seed with respect to the contact area of the high-Tcsuperconductor. By this, different distances of the levitating surface, which is the surface that faces directly the magnet, from the seed were obtained. Results are presented and discussed.

Cochleomeatal scintigraphy (CMS) and CT or air CT cisternography are today the methods of choice for the detection or exclusion of a neurootologically suspect acoustic neuroma. Whereas CT as a morphological method of investigation provides better preoperative information, CMS is likely to be superior to CT as a functional investigation technique in relapse diagnosis.

Osteogenesis imperfecta (OI) is an autosomal-dominantly inherited connective tissue disorder characterized by abnormal bone fragility combined with blue sclerae. The association of OI with hearing impairment is commonly known as Van der Hoeve-de Kleyn syndrome. Besides typical symptoms we here report on findings by high resolution CT and by high resolving scintigraphy of the labyrinthine capsule in 3 families (9 patients) with OI, which resemble those in otosclerosis (OS): In 4 of 6 cases with OI and mixed hearing loss, severely decreased pericochlear bone density was established by CT. In these cases, increased bone metabolism could be revealed by high resolving tympano-cochlear scintigraphy (TCS) in the cochlear region. In 2 patients with mixed hearing loss and 3 cases without hearing impairment or with slight conductive hearing loss, bone alteration was not detectable by CT and TCS. These results raise the question whether OI and OS lead to similarlabyrinthine bone alterations, based on differentaetiologies or whether these diseases may co-exist, OS being part of OI.

The loss mechanisms associated with the combined effects of magnetic unbalance and hysteretic damping in a superconducting flywheel system have been modelled under the assumption that the dynamic characteristics of the bearing can be approximated by a linear, elastic isotropic spring with structural damping. The theoretical rundown equation of motion of such systems has been obtained by a Lagrangian approach, neglecting the effects of angular acceleration. The unknown parameters of the theoretical model have been determined by two different identification procedures starting from experimental time versus rotational speed curves obtained during rundown tests performed on a plastic flywheel with embedded permanent magnet, suspended on a highTcsuperconducting stator. In addition to magnetic friction and eddy current losses, the hysteretic nature of the superconducting magnetic bearing gives a significant contribution to the overall losses. Accordingly, the efficiency of the system can be increased by minimizing the unbalance of the rotor.

The temperature dependence of hyperfine interactions at 155Gd nuclei in Gd2Fe14B has been studied in the temperature range from 4.2 to 120 K. The results indicate that the Fe-Gd exchange interactions at the two Gd sites may be different. The frequency spectrum of Gd vibrations has been derived from the temperature dependence of the absorption intensity.

We discuss the results of inelastic neutron time-of-flight spectroscopy on powder samples of C60, K3C60 and Rb3C60. A well structured density of states is obtained from the raw data where the details can be attributed to translational acoustic/optic and librational modes. The intermolecular excitation spectra for all three compounds can be well understood within the frame-work of lattice dynamics of a molecular crystal. We show that a particular sample preparation is necessary to avoid impurity contributions in particular within the gap region between inter- and intramolecular vibrations. There are indications for a weak anomalous temperature dependence of low energy phonons in K3C60 atTc.

Without Abstract:

Es wird ein nuklearmedizinisches Verfahren zum nicht-invasiven Nachweis intraokularer Veränderungen vorgestellt.

Zusammenfassung Kurze Schilderung eines äußerst ungewöhnlich lokalisierten und begrenzten Spontan-Ventilpneumothorax mit differentialdiagnostischer. Abgrenzung desselben.

Description of a new nuclear medical method permitting the application of radioisotopes for otologic diagnosis. It is made possible by use of an specially constructed pinhole collimator for the Anger-camera. The evaluation is done by aid of a special Fortran IV computer program. For the ear scintigraphy the bone-seeking radiopharmacon 99mTc-MDP is applied, and, thus, patients suffering from operatively confirmed otosclerosis exhibit hot spots of the radioisotope in the regions of the oval and the round window or of the cochlea respectively. This method, for the first time, enables in vivo studies of the metabolic activity of otosclerotic foci in all the bony labyrinthine wall.

Abstract:  The emetics apomorphine hydrochloride and emetine dihydrochloride were tested on Weddell seals (Leptonychotes weddellii) to obtain stomach contents for dietary studies. The drugs prostaglandin F2α, carbachol, and hydergine, which have emetic side effects, were also used. None of the drugs induced regurgitation and possible reasons for this are discussed.

After administration of the tumoraffine radiopharmacon 99mTc-DTPA 18 patients with a tumor of the VIIIth. cranial nerve and 15 volunteers with unaffected ears have been studied by use of our high resolving scintigraphic system. In all 18 patients the tumor was ascertained preoperatively by computed tomography-native or only after intrathecal insufflation of air. In each of these cases scintigraphically there was found a pathologic accumulation of radioactivity in projection towards the inner ear canal or the cerebello-pontine-angle, respectively. The diagnosis was confirmed surgically and histologically. Thus, this method enables the scintigraphic demonstration of even small neuroma located merely within the temporal bone.

Fourty-five patients with the tentative diagnosis of Otosclerosis have been examined by use of our high resolving scintigraphic system. In all cases (n=31), where otosclerotic foci had been proven scintigraphically, the diagnosis was confirmed surgically.