Antiplasticization and transition to marked nonlinear viscoelasticity in poly(vinyl chloride)/acrylonitrile–butadiene copolymer blends

A series of PVC/NBR blends with varying acrylonitrile (AN) content in the NBR has been studied in uniaxial tension creep tests. The tests have been carried out at 21.5 ± 0.5°C covering creep times from 10 to 1000 sec. NBR with low AN content, having poor compatibility with PVC, gives the blends with higher compliance and increased time dependence of the compliance. A higher AN content in the NBR gives the blends with the opposite properties when the NBR is added in small amounts. NBR with 40 wt-% AN is found to act as an antiplasticizer giving minimal creep compliance when 7 wt-% NBR is added. The antiplasticization reveals a considerably increased stress level at which the transition from approximatively linear to marked nonlinear viscoelasticity occurs and a decreased stress dependence of the creep compliance in the nonlinear viscoelastic range. Since the antiplasticization is also associated with a suppression of the β-transition mechanism, the results provide a demonstration of the importance of β-mechanism in the stress activated processes responsible for the appearance of nonlinear viscoelasticity in solid polymers.     

Urinary complications of the resectable cancers of the cervix uteri (author's transl)

The authors studied the urinary complications following 721 operations performed between 1960 and 1974 for cervix uterin carcinoma. The surgical method was the one used at the Fondation Curie according to the protocol of treatment. They have noted that: --first, the surgical act as primary treatment (672 cases) was innocuous, as this series showed only 0,6% of the severe complications; in contrast, when the surgery is performed for a recurrence after a total dose irradiation, the severe complications raised to 8%; --secondly, the uretero-hydronephroses following this type of surgery are relatively frequent on the systematic urograms, but most of them are quite asymptomatic and without later sequelae only 0,3% of them required a surgical treatment. The authors analyse the factors influencing the ureteral stenoses, especially the extent of lymphadenectomy and the associated external irradiation. They studied too the ureteral stenoses due to a local recurrence.     

Complete atrioventricular block and acute pancreatitis

A new, specific haemolytic assay for C2 is described using EAC43 (Antrypol) cells and serum deficient in C4 and C2 from a patient with hereditary angio-oedema. The method is simple and the results in pathological and normal sera correlate well with those obtained using the EA and C2-deficient serum method.     

Single-column chromatographic analysis of labeled glutamine and other amino acids in whole blood.

A method is presented for single-column analysis of the concentrations and specific activities of the free amino acids in both whole blood and plasma. Interference from glutathione in whole blood was eliminated by the use of sodium sulfite although losses of about one-half of the cystine and methionine occurred. Seventy-five percent +/- 1 of the glutamine was recovered consistently in both whole blood and plasma so that corrections for this loss readily could be made. Elimination of the baseline shift due to ammonia was accomplished by passing the buffers through ion-exchange columns before entering the sample loops. There were several significant differences between amino acid concentrations and specific activities in whole blood and in plasma, indicating that care should be taken in interpreting data on metabolism of amino acids.