Application of Inverse Design Approaches to the Discovery of Nonlinear Optical Switches.

Molecular switches, in which a stimulus induces a large and reversible change in molecular properties, are of significant interest in the domain of photonics. Due to their commutable redox states with distinct nonlinear optical (NLO) properties, hexaphyrins have emerged as a novel platform for multistate switches in nanoelectronics. In this study, we employ an inverse design algorithm to find functionalized 26R→28R redox switches with maximal ßHRS contrast. We focus on the role of core modifications, since a synergistic effect with meso-substitutions was recently found for the 30R-based switch. In contrast to these findings, the inverse design optima and subsequent database analysis of 26R-based switches confirm that core modifications are generally not favored when high NLO contrasts are targeted. Moreover, while push-pull combinations enhance the NLO contrast for both redox switches, they prefer a different arrangement in terms of electron-donating and electron-withdrawing functional groups. Finally, we aim at designing a three-state 26R→28R→ 30R switch with a similar NLO response for both ON states. Even though our best-performing three-state switch follows the design rules of the 30R-based component, our chemical compound space plots show that well-performing three-state switches can be found in regions shared by high-responsive 26R and 30R structures.

The Intergenerational Transmission of Low Birth Weight and Intrauterine Growth Restriction: A Large Cross-generational Cohort Study in Taiwan.

Objectives Our research provides evidence on the intergenerational fetal programming effect by examining associations in the low birth weight (LBW, birth weight <2500 g) and intrauterine growth restriction (IUGR) status between two adjacent generations from both the maternal and paternal sides. Methods Birth certificate data of the entire Taiwanese population are used to construct three-consecutive-generational samples. The final samples consist of the third-generation children born during 1999-2006 to at least one second-generation (G2) parent born during 1978-1985. Maternal and paternal samples are distinguished based on the gender of G2. We first fit the samples with linear probability models while including extensive explanatory variables to control for myriad confounding factors. We then include G2 sibling fixed effects to account for family-specific heterogeneity. Alternative explanations of sample selection, parents' assortative mating, and grandmothers' postnatal investment are examined. Results We find that significant intergenerational associations in LBW and IUGR only occur matrilineally. Children born to LBW mothers are 2.28 (95% CI, 0.71-3.85; p < 0.01) percentage points, corresponding to 36%, more likely to be LBW compared to children born to non-LBW mothers who are sisters. These associations cannot be explained by the above alternative explanations. Conclusions Under G2 sibling comparisons, children born to LBW (IUGR) mothers are more likely to be LBW (IUGR), but children born to LBW (IUGR) fathers are not. The findings suggest that maternal health is pertinent and that socio-economic interventions may not yield the desired outcomes within a short period of time.