Exploring Dielectric Constant and Dissipation Factor of LTCC Using Machine Learning.

Low-temperature co-fired ceramics (LTCCs) have been attracting attention due to rapid advances in wireless telecommunications. Low-dielectric-constant (Dk) and low-dissipation-factor (Df) LTCCs enable a low propagation delay and high signal quality. However, the wide ranges of glass, ceramic filler compositions, and processing features in fabricating LTCC make property modulating difficult via experimental trial-and-error approaches. In this study, we explored Dk and Df values of LTCCs using a machine learning method with a Gaussian kernel ridge regression model. A principal component analysis and k-means methods were initially performed to visually analyze data clustering and to reduce the dimension complexity. Model assessments, by using a five-fold cross-validation, residual analysis, and randomized test, suggest that the proposed Dk and Df models had some predictive ability, that the model selection was appropriate, and that the fittings were not just numerical due to a rather small data set. A cross-plot analysis and property contour plot were performed for the purpose of exploring potential LTCCs for real applications with Dk and Df values less than 10 and 2 × 10-3, respectively, at an operating frequency of 1 GHz. The proposed machine learning models can potentially be utilized to accelerate the design of technology-related LTCC systems.

Antiproliferative effects of N-heterocyclic indolyl glyoxylamide derivatives on human lung cancer cells.

BACKGROUND: N-Heterocyclic indolyl glyoxylamide compounds are derived from the antimicrotubule agent D-24851, which exhibits anticancer activity after oral administration. The actions of these compounds on lung cancer cells are still unknown. Here, we investigated the effects of two N-heterocyclic indolyl glyoxylamides, BPR0C259 and BPR0C123, on non-small human lung cancer cells. MATERIALS AND METHODS: 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the half maximal inhibitory concentration (IC(50)), cell viability and radiation response of A549 cells and H1299 cells. Apoptosis was determined by sub-G(1) ratio, colony formation assay and caspase-3 activation. Cell cycle distribution was detected using flow cytometry. RESULTS: Both compounds were able to inhibit the viability of human lung cancer cells, although the IC(50) of BPR0C123 was lower than that of BPR0C259. Both compounds induced significant sub-G1 and caspase-3 activation as low as 0.1 µM in both cell lines. These effects were independent of p53 activation because the level of serine-15 phosphorylated p53 was not affected after drug treatment. Furthermore, both compounds induced similar levels of G(2)/M phase arrest and radiosensitivity in these lung cancer cells. CONCLUSION: Current data suggest that N-heterocyclic indolyl glyoxylamides can suppress the proliferation of and potentially increase radiosensitivity of human lung cancer cells.