Identification of 130 kDa cell surface LDL-binding protein from smooth muscle cells as a partially processed T-cadherin precursor

Atypical cell surface lipoprotein-binding proteins of 105 kDa and 130 kDa are present in membranes of vascular smooth muscle cells. We recently identified the 105 kDa protein from human aortic media as T-cadherin, an unusual glycosylphosphatidylinositol (GPI)-anchored member of the cadherin family of cell adhesion proteins. The goal of the present study was to determine the identity of 130 kDa lipoprotein-binding protein of smooth muscle cells. We applied different approaches that included protein sequencing of purified protein from human aortic media, the use of human T-cadherin peptide-specific antisera, and enzymatic treatment of cultured cells with trypsin and GPI-specific phospholipase C. Our results indicate that the 130 kDa protein is a partially processed form of T-cadherin which is attached to the membrane surface of smooth muscle cells via a GPI anchor and contains uncleaved N-terminal propeptide sequence. Our data disclose that, in contrast to classical cadherins, T-cadherin is expressed on the cell surface in both its precursor (130 kDa) and mature (105 kDa) forms.     

Thermal expansion of specimens of niobium and tantalum pentoxides obtained by melting in an optical furnace

Thermal expansion of high-purity niobium and tantalum pentoxides is studied. It is shown that specimens of Nb₂O₅ and Ta₂O₅ obtained by melting in an optical furnace and subsequent rapid cooling in air to room temperature possess a domain of negative thermal expansion and hysteresis of the dependence of the elongation on the temperatures of heating and cooling. Since the volume of a test cell computed from data of x-ray measurement increases with growth in the temperature, the negative values of the elongation of specimens of melted Nb₂O₅ and Ta₂O₅ can be explained by merging of microcracks formed due to anisotropy of the thermal expansion when the ingots are cooled. When designing and fabricating ceramic articles with protective coatings from niobium and titanium pentoxides to be used at 1000°C, preference should be given to ceramics with low and even negative values of CLTE. __________ Translated from Novye Ogneupory, No. 4, pp. 38–43, April, 2007.     

Improving the Steel Degassing Technique by Use of Large-Diameter Snorkels

Test results for degassers equipped with large-diameter snorkels are reported. Increasing the snorkel diameter from 570 to 720 mm made it possible to accelerate the metal circulation through the degassing chamber, to reduce the metal processing time, and to minimize the air-duct crusting. A program is under way aimed at the improvement of durability of the refractory lining for the snorkels, a new design of the lining brickwork, and the development of advanced refractory materials. __________ Translated from Novye Ogneupory, No. 1, pp. 12 – 15, January, 2005.     

Refining and Out-of-Furnace Treatment of IF-Steel in the Oxygen-Converter Shop at the MMK

The Magnitogorsk Metallurgical Combine has mastered the production of galvanized cold-rolled automobile sheet from high-strength IF-type steel with an ultralow carbon content. The steel also has superior stampability. The article describes a technology that the oxygen-converter shop of the MMK is using for the production and out-of-furnace treatment of IF-steel of the required chemical composition. The article touches on several of the factors that help reduce production costs and improve the service properties of cold-rolled sheet obtained from the steel. __________ Translated from Metallurg, No. 8, pp. 44–45, August, 2005.     

Rate of material destruction under unilateral heating

A linear dependence is established between the quasistationary rate of mass entrainment and the square root of the enthalpy of the stagnation flow. An equation is proposed for its computation in a broad range of external action parameters.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. A, pp. 533–540, April, 1987.