Nickel-catalyzed γ-alkylation of cyclopropyl ketones with unactivated primary alkyl chlorides: balancing reactivity and selectivity via halide exchange.

A novel method was developed for synthesizing γ-alkyl ketones via nickel-catalyzed cross-electrophile coupling of cyclopropyl ketones and non-activated primary alkyl chlorides. High reactivity and selectivity can be achieved with sodium iodide as a crucial cocatalyst that generates a low concentration of alkyl iodide via halide exchange, thus avoiding the formation of alkyl dimers. This reaction possessed excellent regioselectivity and high step economy circumventing in situ or pregenerated organometallics.

Prevalence of Elevated Alanine Aminotransferase by Diagnostic Criterion, Age, and Gender among Adolescents.

BACKGROUND: Serum alanine aminotransferase (ALT) activity was measured not only to detect liver disease, but also to monitor overall health. The purpose of this study was to obtain the prevalence of elevated ALT levels among adolescents. METHODS: In a school-based cross-sectional study, a representative sample was analyzed from 9 middle and high schools in Shenzhen, China, during 2017 to 2018. Elevated ALT was defined as diagnostic criterion I (>30 U/L for boys and >19 U/L for girls) and diagnostic criterion II (>40 U/L). RESULTS: From the adolescent population, a total of 7281 students (boys, 4014, and girls, 3267) aged from 10 to 17 years were collected. The prevalence of elevated ALT was 7.11% (6.88% for boys and 7.41% for girls) by criterion I and 2.72% (3.96% for boys and 1.19% for girls) by criterion II. Based on the Shenzhen census and Chinese national census population, the adjusted prevalence of elevated ALT was 7.65% (boys 7.19% and girls 8.21%) and 6.79% (boys 6.07% and girls 7.56%) by criterion I and 2.85% (boys 4.20% and girls 1.16%) and 2.43% (boys 3.49% and girls 1.29%) by criterion II. For age, the overall trends were increasing progressively, regardless of the use of diagnostic criteria for an elevated ALT activity. CONCLUSIONS: This study supplements the gap that the prevalence of elevated ALT levels differed in gender, age, and criteria among adolescents of Shenzhen. We should take the prevalence as a predictor and continue to play a warning and preventive role in preparation for further intervention.

Steep Switching of In0.18Al0.82N/AlN/GaN MIS-HEMT (Metal Insulator Semiconductor High Electron Mobility Transistors) on Si for Sensor Applications †.

InAlN/Al/GaN high electron mobility transistors (HEMTs) directly on Si with dynamic threshold voltage for steep subthreshold slope (<60 mV/dec) are demonstrated in this study, and attributed to displacement charge transition effects. The material analysis with High-Resolution X-ray Diffraction (HR-XRD) and the relaxation by reciprocal space mapping (RSM) are performed to confirm indium barrier composition and epitaxy quality. The proposed InAlN barrier HEMTs exhibits high ON/OFF ratio with seven magnitudes and a steep threshold swing (SS) is also obtained with SS = 99 mV/dec for forward sweep and SS = 28 mV/dec for reverse sweep. For GaN-based HEMT directly on Si, this study displays outstanding performance with high ON/OFF ratio and SS < 60 mV/dec behaviors.