Analysis of different measurement setups for a programmable Josephson voltage standard

The electrical characteristics of two different 1-V binary programmable Josephson arrays, an superconductor/insulator/normal conductor/insulator/superconductor-type Josephson array, and an externally shunted superconductor/insulator/superconductor-type Josephson array, were investigated at ten metrology institutes. Various operational parameters were evaluated and compared using different Josephson array voltage standard setups at microwave frequencies around 70 GHz. The results of the measurements show that both arrays have been working very well and the main differences were not imposed by the arrays themselves, but by the different measurement setups of the laboratories

Cardiac Troponin I and Troponin T: Recent Players in the Field of Myocardial Markers

The troponin (Tn) complex consists of three subunits referred to as TnT, TnI and TnC. Myocardium contains TnT and TnI isoforms which are not present in skeletal muscles and which can be separated from the muscular isoforms by immunological techniques. Using commercially available immunoassays, clinical laboratories are able to determine cardiac TnT and TnI (cTnT and cTnI) quickly and reliably as classical cardiac markers. After acute myocardial infarction, cTnT and cTnI concentrations start to increase in serum in a rather similar way than CK-MB, but return to normal after longer periods of time (approximately one week). Because of their excellent cardiac specificity, Tn subunits appear ideally suited for the differential diagnosis of myocardial and muscular damage, for example in noncardiac surgery patients, in patients with muscular trauma or with chronic muscular diseases, or after intense physical exercise. cTnT and cTnI may also be used for detecting evidence of minor myocardial damage: therefore they have found new clinical applications, in particular risk stratification in patients with unstable angina. In spite of the possible reexpression of cTnT in human skeletal muscles, and of the lack of standardization of cTnI assays, Tn subunits are not far to meet the criteria of ideal markers for acute myocardial injury. Only an insufficient sensitivity in the first hours following the acute coronary syndroms requiries to maintain an early myocardial marker in the cardiac panel for routine laboratory testing