Predicting adsorption isotherms of low-volatile compounds by temperature programmed desorption: iodine on carbon

Equilibrium adsorption isotherms for low-volatile compounds are extremely difficult to measure. A simple technique using temperature programmed desorption (TPD) is proposed. It is demonstrated that the two parameters needed for constructing the Langmuir isotherm can be derived with data from the TPD technique alone. Thus, the Langmuir isotherms of iodine on AX-21 super-activated carbon were obtained with this technique. A series of TPD experiments for samples with different initial loadings of iodine were carried out by varying the heating rates which resulted in different peak desorption temperatures. The peak desorption temperature decreased as the initial loading was increased because of the re-adsorption effect. The Langmuir constant was derived from kinetic theory with the activation energy for desorption obtained from the experiment. The activation energy for desorption was 12.3 kcal/mol. The Langmuir constants determined by this technique were in comparable order of magnitude to the reported values for iodine on activated carbon. The saturation capacity of AX-21 for iodine could also be determined from the TPD data obtained from samples with different initial loadings. The estimated saturation capacity from the TPD experiment was 2.96 g I(2)/g AX-21, which was close to the experimentally measured saturation capacity of 3.25 g I(2)/g AX-21 for the same system.     

The characteristics of integrins expression in decidualized human endometrial stromal cell induced by 8-Br-cAMP in in vitro

Integrins are heterodimeric glycoproteins that have been found to undergo dynamic temporal and spatial changes in the endometrium during the menstrual cycle and in early pregnancy. Specificity of integrins is known to be different in human endometrial stromal cells and decidual cells. These shifts of integrins suggested to play an important role in embryo implantation and can be modulated by progesterone, cAMP derivatives, and cytokines. The mechanisms of decidualization and its precise physiological role are still not clearly understood and in vitro systems could provide an alternative that overcomes limitations of studying such complex biological phenomena in vivo at the time of implantation. This study was undertaken to establish an in vitro model system for human decidualization using 8-bromo-cAMP and to investigate the characteristics of stromal integrin expression in vitro by 8-Br-cAMP. Endometrial stromal cells were isolated and cultured, and then were induced to decidualize by 0.5 mM 8-Br-cAMP for 15 days. Immunofluorescence staining and flow cytometric analyses of the integrin subunits (alpha1, alpha4, alpha5, alpha6, beta1 and alphavbeta3) were performed at day 9. In the presence of 8-Br-cAMP, the staining intensity of alphavbeta3 was significantly higher than control and measurements for alpha1, alpha4, alpha5, alpha6, and beta1 were similar. Immunofluorescent localization of the integrins reflected the differences obtained from the flow cytometric analyses described above. In summary, the expression of alphavbeta3 integrin increased in stromal cells in vitro decidualized by 8-Br-cAMP and this up-regulation of alphavbeta3 integrin expression during decidualization might influence on human implantation.     

Uniqueness and clustering properties of Gibbs states for classical and quantum unbounded spin systems

We consider quantum unbounded spin systems (lattice boson systems) in -dimensional lattice space Z. Under appropriate conditions on the interactions we prove that in a region of high temperatures the Gibbs state is unique, is translationally invariant, and has clustering properties. The main methods we use are the Wiener integral representation, the cluster expansions for zero boundary conditions and for general Gibbs state, and explicitly -dependent probability estimates. For one-dimensional systems we show the uniqueness of Gibbs states for any value of temperature by using the method of perturbed states. We also consider classical unbounded spin systems. We derive necessary estimates so that all of the results for the quantum systems hold for the classical systems by straightforward applications of the methods used in the quantum case.