Measuring oxytocin and vasopressin:bioassays, immunoassays and random numbers

In this review, we consider the ways in which vasopressin and oxytocin have been measured since their first discovery. Two different ways of measuring oxytocin in widespread use currently give values in human plasma that differ by two orders of magnitude, and the values measured by these two methods in the same samples show no correlation. The notion that we should accept this seems absurd. Either one (or both) methods is not measuring oxytocin, or, by ‘oxytocin’, the scientists that use these different methods mean something very different. If these communities are to talk to each other, it is important to validate one method and invalidate the other, or else to establish exactly what each community understands by ‘oxytocin’. A similar issue concerns vasopressin: again, different ways of measuring vasopressin give values in human plasma that differ by two orders of magnitude, and it appears that the same explanation for discrepant oxytocin measurements applies to discrepant vasopressin measurements. The first assays for oxytocin and vasopressin measured biological activity directly. When immunoassays were introduced, they encountered problems: high molecular weight factors in raw plasma interfered with the binding of antibodies to the hormones, leading to high and erroneous readings. When these interfering factors were removed by extraction of plasma samples, immunoassays gave measurements consistent with bioassays, with measures of turnover and with the sensitivity of target tissues to exogenous hormone. However, many recent papers use an enzyme‐linked immunoassay to measure plasma levels without extracting the samples. Like the first radioimmunassays of unextracted plasma, this generates impossibly high and wholly erroneous measurements

Hochleistungsdiodenlaser und diodengepumpte Festkoerperlaser. Thema: Optische und thermische Eigenschaften von Hochleistungslaserdioden Abschlussbericht

Investigations of optical and thermal properties of high power laser diodes (HLDs) provided a lot of new results for achieving a better diode performance by using the knowledge of optimization of the semiconductor structure and the thermal architecture of diode laser. Theoretical modeling was done for obtaining better understanding of the interaction between thermal and optical processes in laser diodes in particular in the facet region. The calculated temperatures of the laser facets for certain operation parameters were in good agreement with the data obtained in micro-Raman facet temperature measurements. Further theoretical and experimental results were achieved on the catastrophical optical damage (COD) mechanism in the facet region. Finite Elemente Modeling (FEM) was used to investigate the influence of different structure and material parameters e.g. layer thickness, material composition, doping concentration, and parameters of the thermal architecture on the thermal behavior of the diodes. The transient temperature behavior of high power laser diodes was monitored for different mounting configurations. The diode behavior from ns pulses up to cw-operation was measured in detail. Nondestructive methods have been developed for both strain characterization and defect estimation. A new optical scanning technique based on photocurrent spectroscopy was developed successfully to find out local weakpoints upon aging. With the near-field scanning optical microscopy (NSOM) technique these processes were characterized in sub-#mu#m region. Fourier transform spectroscopy was used to obtain the rise of the defect concentration and the levels depths of the defect created upon aging. (orig.)SIGLEAvailable from TIB Hannover: F98B470+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Grundlagenuntersuchungen zur Leistungs- und Lebensdauerbegrenzung, Alterung und Verspannung von Hochleistungslaserdioden Schlussbericht

SIGLEAvailable from TIB Hannover: F02B1160 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman