Morphology and dynamic mechanical spectra of crystalline copolymers of ethylene and acenaphthylene

In a previous paper, results of morphological studies using electron microscopy and X-ray diffraction were reported concerning random and non-random olefin copolymers of ethylene. As comonomers, relatively low concentrations of n-alpha alkenes and 5-methyl norbornene-2 were used. It was tentatively concluded that one possibility for morphological changes observed in the n-alpha alkene copolymers was a change in direction of chain folding. These studies have been continued with copolymers of ethylene and acenaphthylene. The intent was to pursue effects of vicinal substitution; however, the result was to produce ethylene copolymers of quite high comonomer content which were crystalline and showed no evidence of an independent beta mechanical transition. Further, definite evidence was found to indicate a change in the direction of chain folding in the polymer crystals.     

Long spacings of six alkyl esters of two octadecenoic acids

X-ray powder diffraction data are presented for some normal alkyl esters of two octadecenoic acids. The crystal long spacings observed for esters of elaidic acid are shown to be linearly related to the length of the carbon chain of the ester group. Little difference in crystal long spacings was observed between esters ofcis andtrans acids. Melting points of alkyl esters of elaidic acid are reported.     

Preparation of some mixed diesters of aliphatic diols and their evaluation as plasticizers

Mixed diesters of three diols-ethylene glycol, diethylene glycol, and 2-butene-1,4-diol—were prepared wherein one of the ester moieties was benzoate. The laurates were shown to be excellent plasticizers for polyvinyl chloride (PVC) resin. Diesters containing two aroyl groups, or benzoyl and a short branched-chain alkanoyl group were also shown to be compatible plasticizers for PVC resin. Longer chain acids, including oleic and erucic, gave incompatible plasticizers. Benzoyloxyethoxyethyl laurate plasticized PVC had low temperature properties, volatility, and thermal stability superior to PVC plasticized with di-2-ethylhexyl phthalate.     

Synthesis and purification of trisulphoindigo and reversed-phase high performance liquid chromatographic determination of trisulphoindigo in FD & C Blue No.2

The effect of temperature on product formation during the sulphonation of indigo with concentrated sulphuric acid and 30 % fuming sulphuric acid was studied with the aid of high performance liquid chromatographic (HPLC) analysis. Trisulphoindigo was prepared by the sulphonation of indigo with concentrated sulphuric acid at 160°C. The di- and tetra-sulphoindigo side products formed during the reaction were removed by preparative HPLC to yield a product of high chromatographic purity. The trisulphoindigo content of the food dye FD & C Blue No. 2 and the purity of commercially available trisulphoindigo were determined by HPLC analysis.     

The microbiological profile of chilled and frozen chicken

To determine the effect of different refrigeration and freezer temperatures on the microbiological profile of chicken, 50 commercially processed broiler chickens were each split in half on the day of processing. Equal groups were held at 4, 0, -4, -12, and -18 degrees C (40, 32, 26, 10, and 0 degrees F), respectively for 7 days. One half of each group was then transferred to a 0 degrees F holding chamber for an additional 7 days. Carcass halves were rinse sampled with 100 ml of phosphate-buffered saline and the diluent sampled for mesophilic, psychrotropic, coliform, and salmonellae counts after the initial 7 days at different temperatures and after 7 additional days at -18 degrees C. Ten carcass halves were sampled on the day of processing to give baseline counts. Mesophilic bacteria counts/ml were about log 4.6 on day 0, increased by 2 log after 7 days on carcasses held at 4 degrees C, and were unchanged at all other storage temperatures. Psychrotropic counts/ml were about log 3.6 on day 0 and increased during the initial 7 days by about 3.9, 1.9, and 1.4 logs, respectively on carcasses held at 4, 0, and -4 degrees C and had less than 1 log increase at -12 and -18 degrees C. Coliform counts were about log 2.2/ml on day 0 and had declined to about log 1.5/ml or less by day 7 for all storage temperatures. Escherichia coli counts/ml were about log 2 on day 0 and were reduced about 1 log or more at other storage days. Salmonellae counts were about log 1.5 on salmonellae-positive carcasses and did not change appreciably at any storage temperature. No counts for any organism significantly changed after placement at -18 degrees C.     

Beta-glucuronidase in human mammary carcinomas

The result of prompt squatting is an increase of the venous return and of the arterial resistance. Consequences are increasing of the end-diastolic and systolic chamber pressure, stroke volume, average arterial blood pressure as well as decreasing of the frequency of the pulse controlled by baro-receptors. The regulatory mechanism both change the intensity of heart murmurs of various cardiopathies and of functional heart murmurs in children. Only the systolic murmur of muscular subvalvular aortic stenosis softens. The experiment is most valuable for the recognition of mild insufficiency of semilunar valves.     

The response of Golgi tendon organs to single motor unit contractions

1. Cross-correlation analysis has been used to quantify the responses of cat soleus tendon organs to repetitive twitch contractions of: (a) different motor units within the muscle, (b) single motor units at different muscle lengths, and (c) single motor units when the pulse-train pattern of stimulation delivered to the motor unit axon was altered. 2. Ib afferents were observed which responded to each of several hundred successive motor unit twitches with identical numbers of spikes and with relatively invariant latencies. 3. The present results show that tendon organs are sensitive to subtle alterations in motor unit twitch wave form and amplitude, and that this sensitivity is reflected in the precise timings of their afferent discharge. 4. Examination of these tendon organ responses indicates that the forces produced by single motor units couples to the receptor capsule are well above threshold. Calculations based on these results, and earlier soleus motor unit and muscle fibre data, suggest that the absolute force threshold for tendon organs may be as little as 4 mg, which is less than the estimated minimum twitch force generated by individual soleus muscle fibres. 5. Considering the number of tendon organs in a muscle, and the likelihood that every motor unit is connected with at least one receptor, the sensitivity of tendon organs ensures that every twitch of every motor unit will be reflected in the population of afferent signals projecting to the spinal cord.     

Electrocardiographic abnormalities in hypothyroidism before and after exercise

Eleven men and 50 women with severe hypothyroidism were studied. All patients had a serum PBI less than 3.0 mug/100 ml, 131I 24 hours uptake less than 13% and a a photomotogram contraction and half relaxation time of 380 msec or more. Before exercise the mean +/- SE heart rate was 68.39 +/- 3.26/min, the PR interval 17.08 +/- 0.37 csec, the QRS voltage (sum of the QRS amplitude in leads I, II and III) 16.44 +/- 0.89 mm (10mm = 1.0 mV) and the T wave amplitude 0.06 +/- 0.15 mm. A significant correlation (p less than 0.05) existed between the PBI values and the QRS voltage. Following exercise there was a significant acceleration of the heart rate (+ 23.39/min, p less than 0.001), shortening of the PR interval (-0.66 csec, p less than 0.02) and T wave elevation (+ 0.40 mm, p less than 0.001). ST segment changes were not observed in any case. Replacement treatment in 7 cases resulted in a significant change in the resting heart rate (+ 11.86/min. p less than 0.025), PR interval (-3.28 mm, p less than 0.025) and T wave height (+ 2.50 mm, p less than 0.01). These findings suggest that exercise may be used in the differentiation between hypothyroidism and coronary heart disease. The theoretical importance of these findings is also discussed. An increase in cardiac energy demands during exercise may be the cause for some of the ECG changes observed on exertion.     

Systemic lupus erythematosus in children: the complex problems of diagnosis and treatment encountered in 101 such patients at the Mayo Clinic

Between 1945 and 1970, 101 children (86 girls and 15 boys) with systemic lupus erythematosus were evaluated at the Mayo Clinic. Only 9 children were less than 9 years old at the time of diagnosis. The most frequent presenting complaint was arthralgia; fever, fatigue, and a "butterfly" malar rash also were common. Renal involvement, found in more than 76 per cent of patients, was a prognostically poor sign. The overall survival of children with renal involvement is improved by the use of adequate steroid therapy.