Nanometrology for industrial applications

The development of continuously decreasing workpiece tolerances lies in one line with the perspective of nanotechnology. To fulfil metrological demands since about 1982 new high resolution and high precision measuring devices have been developed. These are computerized instruments and the measuring results are very illustrative figures of tested specimens. But the problem of calibration in the nanometric range is still an open question which normally is done only with high uncertainty. New ideas to find a solution for the problem of sufficiently accurate calibrating will make possible that this measurement technique will be used on a broad basis also in industry.     

Effect of tyrosine kinase and tyrosine phosphatase inhibitors on ATP- and thapsigargin-induced CA2+ entry in rat peritoneal macrophages

The production of eicosapentaenoic acid [20:5omega3; EPA] from Shewanella gelidimarina (ACAM 456T) was investigated with respect to growth temperature and growth on sole carbon sources. The percentage and quantitative yield of EPA remained relatively constant at all growth temperatures within or below the optimal growth temperature region. At higher growth temperatures, these values decreased greatly. Growth on differing sole carbon sources also influenced the percentage and amount of EPA produced, with the fatty acid composition influenced by provision of potential acyl chain primers as sole carbon sources. The highest amounts of EPA occurred from growth on propionic acid and L-leucine respectively, while the highest percentage of EPA occurred from growth on L-proline. Monounsaturated fatty acid components and EPA were concentrated in phosphatidylglycerol (PG), while the proportion of branched-chain fatty acids was elevated in phosphatidylethanolamine (PE); the two major phospholipid classes. Specific associations of EPA with other acyl chains were identified within cellular phospholipid classes. The association of EPA with 17:1 and 18:0 acyl chains in phospholipid species was specific to PG, whereas the association of EPA with i13:0/13:0 and 14:0/i14:0 was specific to PE. Such acyl chain 'tailoring' is indicative of the important role of EPA in bacterial membrane adaptive responses. EPA was also a large component (22%) of a non-esterified fatty acid (NEFA) fraction within the total lipid extract of the bacterium. This may point toward a particular role of NEFA in polyunsaturated fatty acid (PUFA) metabolism. The formation of EPA was investigated by labelling with L-[U-14C]serine and sodium [1-14C]acetate. The accumulation of radiolabel within unsaturated intermediates (di-, tri- and tetraunsaturated fractions) was low, indicating a rapid formation and derivatisation of these components. Similar results were found for the unsaturated fatty acid fractions of both PE and PG using sodium [1-14C]acetate radiolabel. The regulation of triunsaturated fatty acid components may be a potential control site in PUFA biosynthesis.     

Vorwort

Ohne Zusammenfassung     

Silizium — Mikrotechnik für thermische Sensoren

Recent developments in the fields of thin film technology processes and silicon micromachining results in thermal sensors with astonishing specifications. Evaporated germanium thermistors placed on membranes of CVD silicon nitride which in turn are fixed at micromachined silicon substrates can act as extremely sensitive thermometers, IR radiation detectors, flow sensors for liquid and gaseous media and sensors for acoustic flow, for example. This paper presents some results of the relevant work at the department of electrical engineering Vienna University of Technology.     

Anticarcinogenic effect of palustran on development of tumors induced by 3-(1-alpha-L-arabinopyranosyl)-1-methyl-1-nitrosourea (AMNU) in rats

Clinical manifestations of superior sagittal sinus (SSS) thrombosis are nonspecific but characterized by headache, papilledema, seizures, focal deficits, progressive coma and death. Recurrent transient focal neurologic deficit is an extremely rare manifestation in superior sagittal sinus thrombosis and the mechanism is unknown. A 45-year-old man presented with headache for two weeks and four episodes of transient (5-10 minutes) right or left hemiparesis for two days. Magnetic resonance image and transfemoral cerebral angiography revealed superior sagittal sinus thrombosis with numerous prominent collateral venous channels. There was no parenchymal lesion. After four days of heparinization, no further transient focal neurologic deficits developed. Follow-up angiography showed partial recanalization of the SSS. Possible mechanism of transient ischemic attacks in this patient is thought to be a transient functional disturbance due to a temporal reduction of tissue perfusion in the process of operating fully-enough collateral channels.     

Value of somatostatin receptor scintigraphy: a prospective study in gastrinoma of its effect on clinical management

BACKGROUND & AIMS: Recently [111In-DTPA-D-Phe1]-octreotide was approved for somatostatin receptor scintigraphy (SRS) of gastroenteropancreatic tumors. SRS and other tumor localization methods can be time consuming, expensive, and involve patient inconvenience. The role of SRS in comparison to other tumor localization modalities remains undefined because the relative effects of these methods on management have not been studied. The aim of this study was to determine whether SRS alters clinical management in Zollinger-Ellison syndrome. METHODS: One hundred twenty-two consecutive patients were studied prospectively. Each patient was assigned to one of five different clinical categories. Conventional imaging studies (ultrasonography, computerized tomography, magnetic resonance image, angiography, and bone scan) were performed, and the management was proposed. SRS was then performed. Clinical management was reassessed, and whether SRS altered management was determined based on six criteria. RESULTS: SRS was superior to any single imaging study. SRS altered management in 47% overall and in 22%-60% of patients in the five different clinical categories. Primary tumor localization and clarification of equivocal localization results from conventional studies were the principal reasons for altering management. SRS was equally useful in patients with or without metastatic liver disease. CONCLUSIONS: Because of the ability of SRS to alter clinical management combined with its superior sensitivity, high specificity, simplicity, and cost-effectiveness, SRS should be the initial imaging modality for patients with gastrinomas.     

Untersuchungen Zur Festigkeit labormäßig hergestellter Silicium-Mangan-legierter Sinterstähle

Investigations on Mechanical Properties of Si? Mn-sintered steels Produced under Laboratory Conditions The influence of graphite additions on microstructure and behaviour under static and cyclic loading is studied for a newly developed sintered steel. For an optimum carbon content fatigue tests are carried out on notched and unnotched specimens. The results of these constant amplitude axial loading experiments are promising and show some advantages compared with the results of commercial sintered steels.     

Die Karbonatschmelzen-Brennstoffzelle — Grundlagen für den Kraftwerkseinsatz

Conventional energy transforming techniques aiming at power production are based on the Carnot process, in which process heat is supplied by burning fossil combustibles. In the fuel cell, power is generated directly by the fuel, i.e. chemically bound energy, by means of a reversible electrochemical change. As for the stationary use in the energy industry, the Molten Carbonate Fuel Cell (MCFC) pertaining to the high temperature fuel cells is particularly adequate, as the operating temperature in the range of 650 °C allows for an optimal waste heat utilization. In this paper, the bases of MCFCs for the use in power plants is illustrated by the example of the 1 MW pilot project of Kawagoe (Japan) being under construction.