Search

Accurate and repeatable methods for recording tooth contacts are required for the clinical management of problems related to occlusion. A thorough understanding of the materials and procedures used in these methods is important to achieve desirable results in the treatment of such problems. This study compared three occlusal examination methods to determine the influence of materials and procedures on the number of tooth contacts recorded. Tooth contacts were analyzed at two lateral mandibular positions with each method. It was found that the method that uses black silicone recorded the highest number of tooth contacts. Thus the most frequent type of occlusal pattern observed was full-balanced occlusion. This study suggested that the disparities of results reported in literature on occlusal contact patterns could be the result of the different materials and methods used for occlusal registration.

Three packaging materials (tortilla-packing paper, low-density polyethylene and high density polyethylene) were used to evaluate tortilla shelf-life at two different temperatures (-10 degrees C and 5 degrees C). Tortilla quality changes upon storage were evaluated by measuring pH, total moisture, texture (puncture and cutting resistance) and sensory characteristics. Results were analyzed by means of covariance analysis and slope contrast between treatments with a 0.05 level of significance. At -10 degrees C, the quality of tortillas did not change significantly during 11 days of storage, and the influence of the packaging material was negligible. Tortilla kept at 5 degrees C in high or low-density polyethylenes, had significantly better quality than the paper-packaged product. Textural changes were best shown by the Instron puncture resistance test than by the cutting resistance test. At 5 degrees C, packaged tortillas had a microbiologically stable level for up to seven days, while that at -10 degrees C significantly improved over the storage period.

Screening for hypothyroidism has been achieved by seeking raised concentrations of thyroid stimulating hormone (h-TSH) in dried blood samples collected on absorbent paper from some 1700 newborn babies each week using double antibody radioimmunoassay and 125I-label counting on a NE1600 gamma counter linked to a HP9815S desk top calculator. Specificity, accuracy, and quality control of the assay have been investigated. The calculator programme stores all count, time, and calculated data and uses log-log function formation and third-power homoscedastic polynomial fit to the calibration data followed, if necessary, by elimination of outliers set at p= 0·5 %. Branching in the calculation procedure provides the ability to process sample data in subgroups, completely to reprocess data (including presentation in a form suitable for making a histogram plot), and to reset without loss of data in case of instrument or main power failure. Variance analysis was used to select the minimum duration of count (50 s), and it was demonstrated that homoscedasticity pertains in the regression calculation.

This paper describes the organosolv delignification of depithed bagasse using glycerol–water mixtures without a catalyst. The experiments were performed using two separate experimental designs. In the first experiment, two temperatures (150 and 190 °C), two time periods (60 and 240 min) and two glycerol contents (20% and 80%, v/v) were used. In the second experiment, which was a central composite design, the glycerol content was maintained at 80%, and a range of temperatures (141.7–198.3 °C) and time (23–277 min) was used. The best result, obtained with a glycerol content of 80%, a reaction time of 150 min and a temperature of 198.3 °C, produced pulps with 54.4% pulp yield, 7.75% residual lignin, 81.4% delignification and 13.7% polyose content. The results showed that high contents of glycerol tend to produce pulps with higher delignification and higher polyoses content in relation to the pulps obtained from low glycerol content reactions. In addition, the proposed method shows potential as a pretreatment for cellulose saccharification.

SUMMARY.— The method introduced by Strauss and Pochi (1961) for measuring the rate of sebum secretion has been critically investigated and a number of sources of error defined. These are choice and preparation of absorbing papers, the technique of sebum collection, weighing, and the ambient humidity. A decrease in the absorbency of the paper during the collection was not found. Modification of the method with careful attention to detail has increased the reproducibility of the results and there is good agreement of the results on both sides of the forehead and in collections made over a 7-week period. The amount of sebum collected in the first 3-hr, period was greater than in subsequent 3-hr, periods but there was a direct linear relationship between the amounts collected in the first 3 hr. and subsequent 3-hr, periods. The view that the method measures the sebum secretion rate is critically discussed in the light of this observation. It is suggested that the amount of sebum collected may be more directly related to the pool of sebum already secreted. Since the size of this pool is related to the rate of sebum secretion the method provides an indirect measure of this function. Until we know more precisely what we are measuring we prefer to use the descriptive term “rate of sebum excretion”.