PREDICTION OF MICROPORE GROWTH DURING GASIFICATION REACTIONS

The concept of changing pore geometry during the course of a reaction allows the microscopic solid-gas reaction models to have the potential to describe the porosity change during the reaction. However, only the bulk porous properties can be predicted due to the pore size range chosen for most of these models. The two population systems, micropore and macropore, chosen by the model of Zygourakls et al. [1] provides a method for predicting micropore property changes. However, this model over-predicts micropore property changes because it assumes that the average micropore radius is enlarged. By examining several sets of published carbon gasification data, it is shown that the average micropore radii are not enlarged by gasification. The commonly-used concept that reaction will enlarge all the pore radii is the major reason for the prediction error. A new concept is proposed in which the reaction will not enlarge the size of the micropores and will maintain a constant micropore length by reacting at both ends of micropores at equal rates. Based upon this concept, the model of Zygourakls et al. [1] has been modified. Both the original and the modified models can predict the gasification rate well by utilizing data from the carbon activation study of Yanai [2]. The model of Zygourakls et al. [1] gives a micropore surface area change close to the measured value, but the reaction enlarged micropores result in predicting high of values of micropore volume changes and average micropore sizes. The steady-state micropore concept used in the improved model predicts more realistic micropore property changes.     

A novel approach for modeling deregulated electricity markets

The theoretical framework developed in this study allows development of a model of deregulated electricity markets that explains two familiar empirical findings; the existence of forward premiums and price-cost markups in the spot market. This is a significant contribution because electricity forward premiums have been previously explained exclusively by the assumptions of perfect competition and risk-averse behavior while spot markups are generally the outcome of a body of literature assuming oligopolistic competition. Our theoretical framework indicates that a certain premium for forward contracting is required for efficient allocation of generation capacity. However, due to the uniqueness of electricity and the design of deregulated electricity markets this premium might be substantially higher than its optimal level.     

Lack of DMBT1 expression in oesophageal, gastric and colon cancers

The cell-wall characteristics of Gardnerella vaginalis grown in conventional and biofilm systems were studied by electron microscopy. The gram-positive nature of the cell wall was confirmed. Novel cell-wall particles which appeared to be associated with cell division were also identified, particularly in organisms of biofilm origin.     

Tracheal intubation in infants

BACKGROUND: So far only a few cases of carcinoma in situ of the fallopian tube have been reported, but its detailed clinical and pathologic findings, including cytology, have not been fully described. CASE: A 70-year-old female was admitted to our hospital because of irregular genital bleeding. Endometrial smear revealed a small number of atypical cells with a clear background. Hysterectomy, bilateral salpingo-oophorectomy and omentectomy were performed. Grossly, a grayish white papillary tumor, measuring 1.5 x 1.0 cm, was observed within the lumen of the left fallopian tube. Microscopically, the diagnosis of papillary adenocarcinoma in situ of the left fallopian tube was made according to 1992 International Federation of Gynecologists and Obstetricians fallopian tube staging. CONCLUSION: Although endometrial brush cytology is not sensitive enough to detect a primary carcinoma of the fallopian tube, our case indicates that it may contribute useful information on extrauterine diseases and can detect a stage 0 cancer of the fallopian tube. Clinicians, as well as pathologists, should consider the possibility of fallopian tube cancer if cervical or endometrial cytology shows atypical cells with papillary patterns with a clear background but endometrial curettage cannot prove malignancy.     

Interactions between lonidamine and beta- or hydroxypropyl-beta-cyclodextrin

Equilibrium dialysis and Scatchard plots were used to establish that human and rabbit paraoxonases both have two calcium binding sites. Independent-site and stepwise constant analyses were used to calculate a higher affinity site (Kd1) of 3.6 +/- 0.9 x 10(-7) M for human A paraoxonase, and 1.4 +/- 0.5 x 10(-8) M for rabbit paraoxonase, and a lower affinity site (Kd2) of 6.6 +/- 1.2 x 10(-6) M for human A paraoxonase, and 5.3 +/- 0.94 x 10(-6) M for rabbit paraoxonase. In both species, the higher affinity sites were found to be essential to maintain hydrolytic activity; complete removal of calcium led to irreversible inactivation. The lower affinity sites were required for catalytic activity, and their binding of calcium was reversible. Experimentally estimated values of Kd2 based on the concentration of calcium required to obtain half the maximum enzymatic activity were 3 microM for human A and B paraoxonases, and also in the order of 3 microM for rabbit paraoxonase, using three different substrates. Calcium was the only metal found that protects against denaturation and also confers hydrolytic activity with these two mammalian paraoxonases.