Effect of high anodic polarization on the passive layer properties of superduplex stainless steel friction stir welds at different chloride electrolyte pH values and temperatures

The conditions used for friction stir welding of duplex stainless steels determine the resulting mechanical and corrosion performance of the material.This study investigates the corrosion resistance of UNS S32750 and S32760 superduplex stainless steels(SDSSs)joined by friction stir welding,employing cyclic polarization,Mott–Schottky,and microscopy techniques for analysis.The microscopy images indicated the presence of a deleterious intermetallic phase after electrolytic etching of S32760,as well as decreased corrosion resistance.The presence of molybdenum in the steels promoted better passive behavior at low pH.The Mott–Schottky curves revealed p-n heterojunction behavior of the passive oxide.Images acquired after the polarization test by scanning electron microscopy showed higher passivation propensity with increases of temperature and pH.     

Effect of heat treatment on the ATPase activity of various sarcoplasmic reticulum preparations

Summary Ca²⁺-stimulated ATPase activity of sarcoplasmic reticulum (SR) preparations is activated after a short period of preincubation at temperatures between 40 and 45°C, but for temperatures higher than 48°C pronounced denaturation is observed. Heat denaturation is decreased if Mg²⁺ or K⁺ are present during heat treatment.Acknowledgments. This work was supported by research grants from Instituto de Alta Cultura (Grant No. CB/2) and the Calouste Gulbenkian Foundation. We are grateful to Drs.A. P. Carvalho andV. M. C. Madeira for many discussions and suggestions during the course of this work.     

Electron microscopy of thin sections of reticulocytes

Zusammenfassung Retikulozyten von Meerschweinchen, in denen Anämie durch Blutentzug hervorgerufen worden war, wurden in Dünnschnitten elektronenmikroskopisch untersucht. Dabei wurden dieselben filamentösen Körper mit charakteristischer Mitochondrienstruktur, die auch nach teilweiser Trocknung hämolysierter Ausstriche von Retikulozyten auftreten, gefunden. Diese Filamente formen die durch Vitalfärbung (Janusgrün B) dargestellte innere Struktur der Retikulozyten und besitzen Affinität zu den spezifischen Mitochondrienfarbstoffen. Auf Grund dieser Feststellungen wird die Natur der «substantia granulo-filamentosa» für mitochondrienartig und somit präexistent gehalten.

---

---

This study has been aided by a grant from the Conselho Nacional de Pesquisas (Brazil).     

Effects of a crystalline proteinase fromBacillus subtilis (Nagarse) on angiotensins I and II

Zusammenfassung Nagarse, eine vomBacillus subtilis gewonnene kristalline Proteinase, bewirkte eine intensive Inaktivation von Angiotensin II, wobei keine Umwand-lung von Angiotensin I in Angiotensin II festzustellen war. Die mögliche Identität zwischen einem aus einer menschlichen Plasmafraktion gewonnenen Polypeptid nach Nagarse-Impfung mit Angiotensin II wird geprüft.     

Ultrastructure of a mucous gland cell found in the tube feet of the starfishAsterina stellifera

Resumen Es describida la ultraestrutura de un segundo tipo de célula glandular mucosa que es encontrada en el pié ambulacrario de la estrella del marAsterina stellifera. Los gránulos secretores de esta célula tienen en su interior una ultraestrutura en forma de pequeños puntos densos y delicadas fibrillas, mas faltando una organizatión, principalmente comparada con la organizatión del otro tipo de granulo mucoso, también encontrado en el mismo pié ambulacrario.     

Genetic analysis of modifier variability inDrosophila subobscura

Summary The previously detected modifier variability acting on the expression of the Bare (Ba) locus inDrosophila subobscura is demonstrated to be due to polygenes situated along the chromosome O. From crosses between isogenic lines of high and low modifier effect we ascertained the presence of approximately 5 modifier loci.We are grateful to Dr M. Green for valuable comments on the experimental design used in this paper.