Distribution of one of the ascitic fluid antigens of ovarian cancer patients in malignant tumors of the stomach and intestines

The indirect immunofluorescent technique was used to study the distribution of the ascitic fluid antigen (AgD) on histological sections from surgical specimens of gastric and colon tumours from proximal to distal lines of resection. AgD was found in gastric tumours exceptionally in the tumour area and in colon cancer--both in the tumour stroma and in surrounding histologically normal mucosa.     

Engineering in Action

Improvements in operational performance of the refractory lining of a direct-current electric furnace for cobalt smelting achieved at the Ufaleinikel Joint-Stock Co. in collaboration with the Kombinat Magnezit Joint-Stock Co. are reported.     

Increasing the precision of a device used to determine the dynamic coefficient of friction

A theoretical evaluation of the potential application of a device with inclined plane for determining the dynamic coefficient of friction is given. Structural changes in the device that make it possible to increase its precision are proposed. Computational equations for estimating the resolution of the device are presented. __________ Translated from Izmeritel’naya Tekhnika, No. 11, pp. 24–26, November, 2007.     

Analyzing conductance-frequency curves of metal-insulator-semiconductor structures subject to surface-potential fluctuations and electrically active states inside the insulator

For metal-insulator-semiconductor structures, a technique is described of analyzing the normalized conductance measured as a function of frequency with regard to the random variation of surface potential and the presence of electrically active states inside the insulator. Parameters are selected that are to be used in evaluating the amount by which the conductance-frequency characteristic is broadened. Analytical expressions are derived for the parameters. A method is proposed for separating the respective contributions of the tunneling and fluctuation mechanisms of the broadening. It enables one to evaluate the depth of the electrically active states and the variance of the surface potential when the two factors make comparable contributions to the inhomogeneity of the insulator-semiconductor interface.     

Effect of the Molecule Structure of Acetylene Compounds on the Kinetics of the Electrode Reactions of Iron in Hydrochloric and Sulfuric Acids

The electrochemical interaction of acetylene compounds, both with and without -hydrogen, with iron in hydrochloric and sulfuric acids was investigated by potentiostatic voltammetry on a rotating disk electrode and capacitance measurements on a stationary electrode. The tendency of acetylene compounds to electrochemical reduction correlates with their ability to polymerize on iron in acidic solutions. The presence of -hydrogen atom determines the ability of an acetylene compound to polymerize on iron, thus inducing the secondary inhibition. The compound containing no -hydrogen manifests only adsorption mechanism.     

Synthesis of Intercalation Compounds in the Graphite–HNO3–H3PO4System

The highly oriented pyrolytic graphite–HNO₃–H₃PO₄system was studied by x-ray diffraction and potentiometry at different acid concentrations. The results demonstrate that chemical and electrochemical intercalation in the graphite–98% HNO₃–85% H₃PO₄system yields graphite nitrate, a binary graphite intercalation compound (GIC). H₃PO₄is shown to have an ambiguous effect on the concentration ranges of different stages of graphite nitrate, shifting them to lower HNO₃concentrations as compared to the graphite–HNO₃–H₂O system. In the graphite–98% HNO₃–100% H₃PO₄system, a stage II ternary GIC is obtained, with an intercalate layer thickness d _i 4.7 Å. Stages II–VI of this GIC were prepared via exchange reaction between graphite nitrate and 100% H₃PO₄. A mechanism for the formation of the ternary GIC is proposed. The synthesis of the cointercalated GIC is likely to involve two steps: in the first step, graphite nitrate is formed; subsequent reaction in the intercalate layer leads to partial replacement of solvated HNO₃by H₃PO₄molecules.     

Organ-specific antigens of the human intestines detectable in tumors

Rabbit antisera to an organospecific intestinal antigen are obtained. This antigen has beta 2-electromobility, is thermolabile, is not extracted by perchloric acid and phenol and immunologically differs from CEA. The antigen is found in bottom zone of colonic crypt and in carcinomas of colon and rectum.