Direct Acylation of Unactivated Alkyl Halides with Aldehydes through N-Heterocyclic Carbene Organocatalysis.

Catalytic acylation of organohalides with aldehydes is an ideal strategy for the direct synthesis of ketones. However, the utilization of unactivated alkyl halides in such a transformation remains a formidable challenge. In this study, we developed a cross-coupling reaction of aldehydes with unactivated alkyl halides through N-heterocyclic carbene catalysis.

Indium Tin Oxide Thin-Film Thermocouple Probe Based on Sapphire Microrod.

Indium tin oxide (ITO) thin-film thermocouples monitor the temperature of hot section components in gas turbines. As an in situ measuring technology, the main challenge of a thin-film thermocouple is its installation on complex geometric surfaces. In this study, an ITO thin-film thermocouple probe based on a sapphire microrod was used to access narrow areas.

Carbetocin vs oxytocin for prevention of postpartum hemorrhage after vaginal delivery: A meta-analysis.

Objective: To evaluate the efficacy and safety of carbetocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery compared with oxytocin.

Methods: We conducted a systemic literature search in PubMed, the Cochrane Library, and Embase without language restrictions from inception of each of database to November 18th, 2018. Randomized controlled trials with outcome measure of blood loss ≥500 ml were eligible if they compared carbetocin with oxytocin to prevent postpartum hemorrhage during the third stage of labor in women undergoing vaginal delivery.

A Through-Hole Lead Connection Method for Thin-Film Thermocouples on Turbine Blades.

To solve the current problems with thin-film thermocouple signals on turbine blades in ultra-high temperature environments, this study explores the use of a through-hole lead connection technology for high-temperature resistant nickel alloys. The technique includes through-hole processing, insulation layer preparation, and filling and fixing of a high-temperature resistant conductive paste. The through-hole lead connection preparation process was optimized by investigating the influence of the inner diameter of the through-hole, solder volume, and temperature treatment on the contact strength and surface roughness of the thin-film for contact resistance.

Cervical Pessary for Prevention of Preterm Birth: A Meta-Analysis.

To investigate the efficacy of cervical pessary placement in preventing preterm birth and perinatal morbidity and mortality in asymptomatic women with a singleton pregnancy and a short cervix, we searched literature in relevant databases. The meta-analysis of the 3 included trials (1412 women) showed cervical pessary placement did not reduce the risk of spontaneous preterm birth <34 weeks in these women (risk ratio (RR), 0.71; 95% confidence interval (CI), 0.