Inelastic structural analysis: Design implications and experience

The current status of inelastic structural analysis is reviewed relative to the needs and requirements for design of elevated temperature nuclear reactor components. The classes of inelastic problems that can be solved in a practical way are identified and the overall scope of ongoing validation programs is reviewed. Three classes of problems are identified where the further development of simplified analysis techniques is necessary to make them tractable for design application.     

Nucleic acids. 16. Orally active derivatives of ara-cytidine

Water-soluble derivatives of ara-cytidine (cytarabine, Cytosar) were prepared and tested for antitumor, immunosuppressive, and antiarthritic activities in animals after oral administration. The compounds tested included the 5'-palmitate, 5'-benzoate, and 5'-adamantoate esters of ara-cytidine, made water soluble by use of their hydrochloride salts of peptidyl derivatives, and two basic 5' esters (5'-nicotinoate and 5'-quinuclidinate) as their hydrochloride salts. Five of the compounds had antitumor activity superior to that found with ara-cytidine itself after oral administration in the L1210 leukemic mouse assay. One of these, 5'-adamantoyl-ara-cytidine hydrochloride, had antitumor activity after oral administration approaching that achieved with parenterally administered ara-cytidine.     

Even distribution of 133Xe bolus inhaled at residual volume in healthy subjects

We selected from among 46 healthy students (22 to 31-yr-old) 7 subjects (group A) in whom the normalized height of phase IV (height of phase IV/phase IIIx100), after inhaling a bolus of He at RV, was very small (10%). We compared them with 6 subjects (group B) selected on the basis of a tall phase IV (78%, A vs. P P less than 0.005). Age and height were comparable, but weight was lower (P less than 0.05) and RV/TLC ratio (but not other spirographic indices) was larger (P less than 0.025) in group A. The average amplitude of cardiac oscillations was 4 times higher in group B (P less than 0.005). He closing volume, but not closing capacity was less in group A (P less than 0.05). A bolus of 133Xe inhaled at RV was nearly uniformly distributed in group A while producing a large vertical gradient in group B. The difference between groups A and B may reflect a difference in the mechanical properties of the chest wall leading to a less complete empting of the lung in the former group.     

Ultrastructural and enzymic modulation of HeLa cells induced by sodium butyrate and the effects of cytochalasin B and colcemid

Sodium butyrate causes HeLa cells to assume an elongated and jagged shape. Ultrastructurally this change is associated with the formation of bundles of microfilaments. Desmosomes were present between adjacent cells. No increase in microtubules was observed in the butyrate-treated cells. Butyrate induces an increase in the activity of 2 membrane-bound enzymes, alkaline phosphatase and 5'-nucleotidase; however, the activity of a third membrane enzyme, acetylcholine esterase, is reduced. The activities of the several other enzymes with different subcellular localizations are not significantly increased. Colcemid and cytochalasin B prevent or reverse the butyrate-mediated change in HeLa cell morphology and also partially inhibit the induction of alkaline phosphatase activity in these cells. The effect of cytochalasin B on alkaline phosphatase induction may be caused by a reduction in protein synthesis produced by this fungal metabolite.     

Histamine-stimulated gastric secretion in rats with chronic renal insufficiency

Chronic uremia was induced by long-term maintenance of rats which had undergone sub-total nephrectomy, with sham-operated rats serving as controls. Chronic gastric cannulas and chronic vascular catheters (vena cava) were installed and the rats were stimulated with intravenous infusion of histamine. In uremic rats, the volume of gastric juice, output of HC1 and H+ concentration were significantly higher than in the controls during the 6-hour secretion experiments.     

Water recycle method for washing alkali-refined soybean oil

Vegetable oil refineries are faced today with cutting down on pollution caused by their waste water. A method was developed for washing alkali-refined soybean oil with treated, recirculated wash water. In this method, wash water passes through a cation exchange resin that removes Na, and the slightly acid water goes back into the system for continuous reuse. The disposal problem arising from current industrial practice can be largely or entirely avoided by this reuse method. The new method might well be applicable to other oilseed processing. Batch tests were first made by mixing water, alkalirefined soybean oil and cation exchange resin. The amount of Na in the soybean oil was reduced from 34 to less than 0.5 ppm. In continuous washing tests conducted in a Podbielniak contactor with water treated by a cation exchange resin, the Na level of a commercially refined oil (not water-washed) was reduced from 34 ppm to less than 1.5 ppm. These results are comparable to or better than those obtained by the conventional method of employing fresh water for washing soybean oil. Presented at the AOCS Meeting, Minneapolis, October 1969. Res. Dev. Div., ARS, USDA.