Structure and properties of welded blanks for tools of new high-speed steels

Conclusions In a broad range of values of various factors (pressure during heating and forging, heating and forging time, relative speed of rotation) the torsional strength of welded samples of steels R12+45, R9K5+45, R6M5K5+45, R8M3K6S+45, and R9M4K8F+45 is constant with a confidence coefficient of 0.95 and meets the requirements. Within this region it is necessary to select friction welding conditions in conformity with the optima technicoeconomic parameters.S. M. Kirov Tomsk Polytechnic Institute. Tomsk Institute of Automatic Control Systems and Radioelectronics. Tomsk Factory of Cutting Tools. Translated from Metallovedenie i termicheskaya Obrabotka Metallov, No. 11, pp. 22–26, November, 1976.     

The College of American Pathologists, 1946-1996. Quality Assurance Service

Since its creation in 1970, the College of American Pathologists Quality Assurance Service Committee has provided important and highly respected interlaboratory programs for daily quality control. In 1988, this committee extended its domain by announcing Q-Probes, a unique benchmarking program for laboratory quality assurance. Because of the success and rapid growth of this program during the next 2 years, the Quality Assurance Service Committee expanded into two committees, namely, QAS-QC and QAS-QA, with expertise concentrated, respectively, in quality control and quality assurance. These committees have compiled a history of significant scientific and educational contributions to members, the international laboratory community, other physicians, and patients. New directions for both committees are now underway so that their contributions can continue in the rapidly changing field of pathology and laboratory medicine.     

Insights into carrier recombination processes in 1.3 μmGaInNAs-based semiconductor lasers attained using high pressure

The threshold current of 1.3 μm GaInNAs lasers increases by ~30%, up to a pressure of 1 GPa compared with a decrease of ~15% for Auger-dominated InGaAsP devices, indicating that direct band-to-band Anger recombination is not important in these materials. The lasing energy varies sub-linearly with pressure, indicative of the increasing interaction of the N-level with the conduction band     

Anisotropy of the spatial distribution of In(Ga)As quantum dots in In(Ga)As-GaAs multilayer heterostructures studied by X-ray and synchrotron diffraction and transmission electron microscopy

High-resolution X-ray and synchrotron (crystal truncation rods) diffraction methods and transmission electron microscopy have been employed to study MBE-grown multilayer In(Ga)As-GaAs heterostructures with arrays of vertically coupled In(Ga)As quantum dots (QDs) in a GaAs matrix. Additional (vertical and lateral) spatial ordering of QDs in perfect crystalline structures, giving rise to undulations of the crystalline planes and quasi-periodic elastic strain, was shown to be essentially anisotropic with respect to crystallographic directions of the [110] type. The anisotropy of the QD formational system of can be accounted for by assuming that the spatial ordering of the QDs and the corrugation of the crystal planes are the initial stages of relaxation of the elastic strain introduced into the system by the QDs. The anisotropic relief of the crystal planes (corrugated growth surface) results from the formation of a system of spatially ordered quantum quasi-wires uniformly filled with QDs. In a multilayer heterostructure with high crystal perfection, the anisotropic relief of the crystal planes is inherited by overlying layers and its amplitude decreases gradually with increasing distance from the source of elastic strain—the superstructure containing In(Ga)As QDs in the given case.     

An NMR flowmeter in an automatic liquid flowmeter test system

Translated from Izmeritel'naya Tekhnika, No. 10, pp. 34–35, October, 1989.     

Kainate-induced apoptosis in cultured murine cerebellar granule cells elevates expression of the cell cycle gene cyclin D1

Recent evidence suggests that neuronal apoptosis is the consequence of an inappropriate reentry into the cell cycle. Expression of the cell cycle gene cyclin D1, a G1-phase cell cycle regulator, was examined in primary cultures of murine cerebellar granule cells (CGCs) during kainate (KA)-mediated apoptosis. Using cultures of CGCs, we found that a 24-h exposure to KA (1-3,000 microM) induced a concentration-dependent cell death with neurons exhibiting characteristic apoptotic morphology and extensive labeling using the terminal transferase-mediated nick end-DNA labeling (TUNEL) method. KA induced a time- and concentration-dependent increase in expression of cyclin D1 as determined by immunocytochemistry and western blot analysis. KA-induced apoptosis and cyclin D1 expression exhibited a similar concentration dependence and were significantly attenuated by the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (50 microM), indicating a KA receptor-mediated effect. Here we present evidence for the first time that KA-induced apoptosis in cultured CGCs involves the induction of cyclin D1, suggesting its involvement in excitotoxic receptor-mediated apoptosis.