The study of the antigenic properties of tissues and organs of animals in ontogenesis
SummaryThe antigenic properties of the tissue of developing crystalline lens of ducks was studied with the aid of anaphylactic reaction with desensitization.Morphogenesis, the rate of growth of crystalline lens and content of ribonucleic acid (RNA) in it were investigated simultaneously. It was demonstrated that during the early stages of embryogenesis (90–130 hours) the antigens are present in the tissue of developing crystalline lens, which are specific only for the definite stage of development (stage-specific antigens). There is formation and intensive growth of the primary fibers of the crystalline lens and increased concentration of the RNA during this period.
Fetuin, a New Globulin Isolated from Serum
DURING a study on the fractionation of serum with ammonium sulphate, I thought it worth while to try whether some of the serum proteins could be isolated more easily from the serum of a newly born animal. Serum from calves not more than two weeks old was used for these fractionation experiments, which immediately indicated a pronounced difference between the serum from the calf and that from the cow. Ultracentrifugal examination of the different fractions revealed the presence of large amounts of a globulin with the sedimentation constant, s20, of the order 3S (1S (Svedberg) = 1 × 10−13 C.G.S.) as compared with the normal s20 ∼ 7S for serum globulin. The main part of the new protein was precipitated between the salt concentration limits 0.37 and 0.45 saturated ammonium sulphate. It was purified further by fractionation with ammonium sulphate and centrifugation in a high-speed air-driven centrifuge. Molecular weight determination gave a value of the order 50,0001.
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.