Dilution and clustering of Fe in the rutile phases of TiO2 and SnO2

ABSTRACT: Dilute magnetic semiconductors of Fe-doped SnO2 and TiO2 with the structure of rutile were prepared in forms of powder and thin films using the techniques of sol gel and pulsed-laser deposition. We present the results of measurement of vibrational density of states of Fe impurity dopants in these oxides and demonstrate the cases of dilution and clustering. The oxygen pressure during the film deposition was varied between 10−1 and 10−8 Torr. In TiO2 films made at 10−1 Torr, Fe is diluted, however, in films made at 10−8 Torr Fe is clustered. The case of true Fe dilution in SnO2 is also shown. In spite of larger mass defect for Fe in SnO2 than that for Fe in TiO2 the dilute Fe species probe the phonon states in SnO2 more faithfully than in TiO2. This result is understood in terms of the combined effect of mass defect and nearest-neighbor force-constant changes. The impurity modes are more pronounced in TiO2 than in SnO2 due to ca. 10% difference of the lattice cell volumes between these two rutile oxides

CELL KINETICS OF HUMAN SQUAMOUS CELL CARCINOMAS IN THE ORAL CAVITY

Cell proliferation characteristic of human malignant tumors has been related to the responses of tumors to various therapeutic means. The present study mainly concerns a routine method to measure cell kinetic parameters in human solid tumors. Proposed for this aim is the in vitro double labeling method under hyperbaric condition. For assessment of the method, two steps were taken. First, cell cycle parameters were compared in a mouse squamous cell carcinoma between this in vitro method and the in vivo percent labeled mitoses method. Second, the in vitro method was applied to eight cases of human squamous cell carcinomas. The results indicate that two sets of the cell cycle parameters of mouse squamous cell carcinoma measured by the two methods are in good agreement within an experimental error. DNA synthesis time, labeling index and cell cycle time of human squamous cell carcinoma varied among cases with a dispersion of 2 to 3-fold, that is, with ranges of 4.1-14.0 h, 14.3-28.7% and 21.2-52.9 h, respectively

Determinants of continuum of care for maternal, newborn, and child health services in rural Khammouane, Lao PDR.

IntroductionThe concept of continuum of care has gained attention as measures to improve maternal, newborn, and child health. However, little is known about the factors associated with the coverage level of continuum of care in Lao PDR. Therefore, this study was conducted 1) to investigate the coverage level of continuum of care and 2) to identify barriers and promoting factors that are associated with mothers' continuation in receiving services in rural Lao PDR.MethodsA community-based, cross sectional study was conducted in a rural district in Khammouane Province, Lao PDR, using a structured questionnaire. The outcome to the express continuum of care was assessed by the modified composite coverage index (CCI) that reflects ten maternal and child health services.ResultsIn total, 263 mothers were included in the final analyses. Only 6.8% of mothers continued to receive all MNCH services. Five factors were shown to have statistically significant associations with modified CCI score: higher educational attainment (B = 0.070, pConclusionsIn this study, we introduced the modified CCI to better explain the utilization of preventive maternal and child health services along with the continuum of care. By utilizing the modified CCI, we identified five factors as determinants of continuum of care. Furthermore, new and modifiable promoting factors were identified for continuum of care: receiving the first antenatal care within the first trimester and family and male involvement. Such demand side actions should be encouraged to improve the continuity of MNCH service use