Investigation of the refractive index repeatability for tantalum pentoxide coatings, prepared by physical vapor film deposition techniques.

Random effects in the repeatability of refractive index and absorption edge position of tantalum pentoxide layers prepared by plasma-ion-assisted electron-beam evaporation, ion beam sputtering, and magnetron sputtering are investigated and quantified. Standard deviations in refractive index between 4*10-4 and 4*10-3 have been obtained. Here, lowest standard deviations in refractive index close to our detection threshold could be achieved by both ion beam sputtering and plasma-ion-assisted deposition. In relation to the corresponding mean values, the standard deviations in band-edge position and refractive index are of similar order.

Limits on Momentum-Dependent Asymmetric Dark Matter with CRESST-II.

The usual assumption in direct dark matter searches is to consider only the spin-dependent or spin-independent scattering of dark matter particles. However, especially in models with light dark matter particles O(GeV/c^{2}), operators which carry additional powers of the momentum transfer q^{2} can become dominant. One such model based on asymmetric dark matter has been invoked to overcome discrepancies in helioseismology and an indication was found for a particle with a preferred mass of 3 GeV/c^{2} and a cross section of 10^{-37} cm^{2}. Recent data from the CRESST-II experiment, which uses cryogenic detectors based on CaWO_{4} to search for nuclear recoils induced by dark matter particles, are used to constrain these momentum-dependent models. The low energy threshold of 307 eV for nuclear recoils of the detector used, allows us to rule out the proposed best fit value above.

Temperature-stable bandpass filters deposited with plasma ion-assisted deposition.

Plasma ion-assisted deposition with an advanced plasma source was investigated to produce narrow-bandpass filters in the near-infrared spectral range for telecommunication applications. The multilayer coatings were qualified by the optical performance, the vacuum-to-air behavior, the temperature stability, and the film stress. TiO(2)/SiO(2) and Ta(2) O(5)/SiO (2) material combinations were used and compared. The coating system produced low absorbing multilayers with a very low coefficient of expansion and low stress. The coefficient of expansion was in the low 10(-6) °C range, and film stress values in the range between 1 and 2 × 10(8) N/m(2) were obtained. TiO(2)/SiO(2) was the preferred material combination. The optical monitoring system allowed the production of bandpass filters with a performance close to that of the theoretical values.

[Intestinal accumulation of 99mTc-HMDP: an unusual finding in bone scintigraphy]. / Intestinale Anreicherung von 99mTc-HMDP: Ein ungewöhnlicher Befund bei der Skelettszintigraphie.

In a 61-year old female with a history of breast cancer the whole-body scan (4 h p.i.) after intravenous injection of 576 MBq 99mTc-HMDP showed an accumulation of activity in the stomach and the whole intestines. The reason was an oral urine intake ("uropotia") taking place between the injection and the whole-body bone scan.

[A case of Maffucci's syndrome]. / Ein Fall von Mafucci-Syndrom.

A 14-year old girl had developed, at the age of 6, a swelling on the left shank. 4 years later, additional tumours appeared. 1990, at the age of 12, she had to be operated because of serious discomfort in the left ankle. The histological diagnosis was haemangioma plus enchondroma. At the age of 14 further haemangiomas developed and in early 1992 she had to undergo another operation of the left thigh. Histologically and immunohistochemically a Mafucci syndrome was diagnosed--a very rare affection belonging to the group of osteochondrodysplasia that usually goes with haemangioma and enchondroma. Radiological, scintigraphic and MTR findings are presented.

Comparison of gall bladder bile and endoscopically obtained duodenal bile.

In 10 patients with gall stone disease (eight women, two men; mean (SD) age 47.4 (13) years), bile was obtained by endoscopic aspiration after stimulation of the gall bladder with ceruletid and also by fine needle puncture of the gall bladder under local anaesthetic. The total lipid concentration of the puncture bile samples was mean (SD) 11.9 (4.7) g/dl, significantly higher than the endoscopic bile samples (3.9 (3.3) g/dl, p less than 0.001). Total bile acids, phospholipids, and biliary cholesterol (expressed in mol%) and cholesterol saturation index showed no significant differences between the two types of samples. The glycocholic acid concentration in the endoscopically obtained bile (27.7 (6.6) mol% v 23.3 (5.4) mol%; p less than 0.01) was significantly higher than the puncture bile samples. Puncture bile exhibited a significantly shorter nucleation time (3.5 (3.3) days v 19.6 (11.9) days; p less than 0.001). For determination of the nucleation time, endoscopic bile aspiration after gall bladder stimulation with ceruletid led to adequately concentrated samples in 50% of the study subjects. Cholesterol monohydrate crystal formation in native bile was observed in six samples of puncture bile and in three samples of the endoscopically obtained bile. The presence of cholesterol crystals and the determination of nucleation time in the puncture bile were the best discriminants between cholesterol and pigment gall stones and correlated well with computed tomogram analysis.

[Morphological changes in the gallbladder after extracorporeal shock-wave lithotripsy]. / Morphologische Veränderungen der Gallenblase nach extrakorporaler Stosswellenlithotripsie.

The present study reports on 51 patients with symptomatic cholecystolithiasis, who accordingly underwent extracorporeal shock-wave lithotripsy (ESWL). In all cases, computed tomography (CT) was performed prior to and after the therapeutic procedure to delineate changes in gall-bladder morphology. Slight edematous thickening of the gall-bladder wall was found in 15 patients. One patient presented a rupture of the gall-bladder with formation of a bilioma in the adjacent liver tissue. In case of calcific concrements, CT revealed a characteristic pattern of fragment distribution following shock-wave treatment, and fragments of various sizes exhibited distinct adhesion to the gall-bladder wall.

[Percutaneous transhepatic lysis of gallstones]. / Zur perkutan-transhepatischen Lyse von Konkrementen der Gallenblase.

The present study reports on morphological findings obtained from 15 patients who were submitted to percutaneous transhepatic contact dissolution of gallbladder concrements with methyl-tert.-butyl ether (MTBE) and--in case of slightly calcified gallstones (n = 10)--with ethylene diamine tetraacetic acid (EDTA). At a maximum intracystic catheter placement time of four days complete lysis was obtained in 12 patients. As could be depicted by CT, the solvents induced significant regional or disseminated chemical cholecystitis in the majority of all cases. However, these changes proved to be completely reversible within about five weeks. It is concluded that with certain types of gallstones contact dissolution can be an effective alternative therapeutic technique which, however, requires meticulous morphological controlling in view of the time-consuming treatment of calcified concrements.

Computed tomography evaluation of radiolucent gallstones in vivo.

Computed tomography facilitates an in vivo classification of gallstones and can aid in the identification of calcifications that escape detection with conventional radiologic procedures. Of patients with radiolucent stones, 54.8% exhibited calcifications either in the form of discrete rims (41.9%) or at the center of the stone (12.9%). Densities of the noncalcified areas of partially calcified stones averaged 40.68 +/- 6.8 Hounsfield units (HU), which was not significantly higher than the average of 31.85 +/- 3.19 HU for noncalcified stones. Calcified regions showed significantly higher densities (240.0 +/- 28.6 HU, p less than 0.001, x +/- SEM). Of the identified stones, 16.1% showed densities greater than 50 HU. These were primarily bilirubin stones, which cannot yet be treated successfully with conservative therapeutic modalities.

Radiographic aspects in transcatheter contact dissolution of calcified gallbladder concrements.

The present study on 10 patients reports upon an attempt to perform percutaneous contact dissolution of partially calcified gallbladder concrements. These gallstones, which exhibited structural calcifications on CT scans, required time-consuming complex dissolution procedures with transcatheter administration of methyl tert-butyl ether (MTBE) and ethylene diamine tetraacetic acid (EDTA). Insertion of the catheter system (5 F) was performed via a percutaneous transhepatic route. Catheter placement was maintained for a maximum of 4 days. Complete lysis was achieved in seven of the ten cases. In six patients, significant regional or disseminated chemically induced cholecystitis and pericholecystitis could be observed on CT examination. However, on follow-up CT examinations, these changes proved to be completely reversible. It has been demonstrated that tolerance of the gallbladder wall and adjacent tissue layer against the lytic media employed is rather limited and that meticulous controlling of the morphological reaction can be helpful in minimizing complications.