Cystic tumours of the breast

A retrospective survey of cystic tumours of the breast seen at the North Middlesex and St Bartholomew's Hospitals, London, has been undertaken to determine their incidence and clinical features. During the years 1967-76 4530 histological examinations were carried out on breast tissue and 1277 breast cancers diagnosed. Intracystic papillary tumours, both benign and malignant, were the least uncommon of cyst tumours, but the malignant type accounted for 0.55% of all the breast cancers. Aspects suggesting the possible presence of an intracystic tumour are discussed.     

Erythrocyte sodium and potassium in patients with hypokalaemia

1. The erythrocyte content of sodium and of potassium were measured in 231 unselected patients with hypokalaemia, and together with net ouabain-sensitive sodium efflux in patients with severe hypokalaemia, before (20 patients) and during potassium repletion (14 patients). 2. The erythrocytes of the patients with hypokalaemia compared with control subjects had on average an increase in sodium content, a decrease in potassium content and a reduction in the rate constant of ouabain-sensitive sodium efflux. All three changes had a similar curvilinear relation to the concentration of potassium in plasma with relatively little change in the measured variable unless the plasma potassium was very low. 3. There was a similar curvilinear relation between the final sodium and potassium content of normal erythrocytes and the potassium concentration of the medium in which they were incubated for 48 h in vitro. 4. These results suggest that the changes in the sodium and potassium content of erythrocytes in hypokalaemia are due to a direct inhibiting effect of the hypokalaemia on the activity of the sodium pump. 5. In many patients with hypokalaemia of moderate degree the increase in erythrocyte sodium content was less than expected from the effect in vitro of a low extracellular potassium concentration. This finding suggests that a compensatory change, presumably an increase in the number of sodium pumps, is a common event even in moderate hypokalaemia.     

Haftfeste Metallisierung von Filtermedien mit Vakuum‐Arc‐Technologie

Adhesive metallization of filter media by means of vacuum arc technology Textile filter media made of high‐performance fibres are used for separation of pollutants from industrial exhaust gases with higher temperatures. PVD‐coating is an innovative process for antistatic finishing of high‐temperature resistant textiles. PVD‐metallizations are extremely adherent, conductive and does not affect the throughput of gas. The results are the base for the industrial use in different textile applications.     

Heavy-tailed mixture GARCH volatility modeling and Value-at-Risk estimation

This paper presents a heavy-tailed mixture model for describing time-varying conditional distributions in time series of returns on prices. Student-t component distributions are taken to capture the heavy tails typically encountered in such financial data. We design a mixture MT(m)-GARCH(p, q) volatility model for returns, and develop an EM algorithm for maximum likelihood estimation of its parameters. This includes formulation of proper temporal derivatives for the volatility parameters. The experiments with a low order MT(2)-GARCH(1, 1) show that it yields results with improved statistical characteristics and economic performance compared to linear and nonlinear heavy-tail GARCH, as well as normal mixture GARCH. We demonstrate that our model leads to reliable Value-at-Risk performance in short and long trading positions across different confidence levels.     

Altered proton extrusion in cells adapted to growth at low extracellular pH

Coronary vasodilator and hemodynamic profiles of JTV-506, a newly synthesized 2,2-bis-methoxymethyl benzopyran-derivative potassium channel opener, were evaluated in conscious dogs. JTV-506 (2.5-10 microg/kg, i.v.) elicited dose-dependent increases in coronary blood flow (CBF) and heart rate (HR) but only slight changes in mean blood pressure (MBP). Other vasodilators such as levcromakalim, nicorandil, diltiazem, and nitroglycerin, when administered intravenously, elicited increases in CBF and HR and a decrease in MBP. When dosed orally JTV-506 (0.01-0.1 mg/kg), levcromakalim (0.01-0.1 mg/kg), nicorandil (1-10 mg/kg), and nifedipine (3-30 mg/kg) also elicited increases in CBF and HR and a decrease in MBP. JTV-506 caused a marked increase in CBF with slight changes in HR and MBP. In contrast to JTV-506, however, the changes caused by levcromakalim, nicorandil, and nifedipine were accompanied by a marked increase in HR and a marked decrease in MBP. These results suggest that the action of JTV-506 on hemodynamics is different from that of other vasodilators, including reference potassium channel openers, and that the profile of cardiovascular action of JTV-506 may be useful in the treatment of angina pectoris.     

Motion Control of Mobile Robots—From Static Targets to Fast Drives in Moving Crowds

Motion control of vehicles under uncertain, noisy, and discontinuous positioning is essential in autonomous navigation in unknown environments. This article suggests two methods for motion control, where the initial parameters of the on-line control are physically explainable, the resulting trajectory as well as the control parameters are asymptotically converging and glitches in the localization are handled robustly. The differences to a known method based on Lyapunov functions are discussed theoretically as well as in terms of actual motion measurements. Physical experiments with landbound vehicles show the reliability and limitations of these different methods in setups employing static attractors, systematically moving targets and fast, unpredictable moving targets in highly dynamical environments. Mainly due to the physical meaning of the control parameters the adaptation to actual kinematics and dynamics is significantly simplified.     

Berechnung und Optimierung von Geometrie und Eingriffsverhalten von Zahnformen beliebiger Achslage

The main benefit, the economical manufacturability of traditional gear profiles, such as an involute, are no longer of major importance in times of computer-aided design and production. Due to existing modern production techniques standard and more sophisticated gear types can be produced with high precision and maintainable financial effort. Especially for non-standard gear types modern gear production systems ensure high quality and reliability to the operator with regard to flank and meshing geometry. Depending on the context of application different gear types have advantages and disadvantages concerning load carrying capacity, effectiveness or noise excitation. Developing an optimized gearing for the desired application is thus a complex and elementary goal within the design process.