Angew Chem Int Ed Engl
December 2024
The 1,2-hydroxysilylation of alkenes is crucial for synthesizing organosilicon compounds which are key intermediates in material science, pharmaceuticals, and organic synthesis. The development of strategies employing hydrogen atom transfer pathways is currently hindered by the existence of various competing reactions. Herein, we reported a novel mechanochemical strategy for the triphasic 1,2-hydroxysilylation of alkenes through a single-electron-transfer pathway.
View Article and Find Full Text PDFMechanoredox chemistry is a rapidly evolving field at the intersection of mechanical forces and chemical reactions. Herein, we have reported a vicinal dibromination of unsaturated hydrocarbons using piezoelectric material (LiTiO) as a redox catalyst. Furthermore, the reaction can be efficiently scaled up to 10 mmol and performed under an air atmosphere at room temperature without solvents or external reductants, and LiTiO can be reused multiple times without a structural change.
View Article and Find Full Text PDFAryl fluorides are important structural motifs in many pharmaceuticals. Although the Balz-Schiemann reaction provides an entry to aryl fluorides from aryldiazonium tetrafluoroborates, it suffers from drawbacks such as long reaction time, high temperature, toxic solvent, toxic gas release, and low functional group tolerance. Here, we describe a general method for the synthesis of aryl fluorides from aryldiazonium tetrafluoroborates using a piezoelectric material as redox catalyst under ball milling conditions in the presence of Selectfluor.
View Article and Find Full Text PDFEarly forecasting of rice panicle blast is critical to the management of rice blast. To develop early forecasting models for rice panicle blast, the relationship between the seasonal maximum incidence of rice panicle blast () and the in the preceding crop, weather conditions, location, and acreage of susceptible varieties was analyzed. Results revealed that in the preceding crop, acreage of the susceptible varieties in class (), altitude, weather conditions 120 to 180 days before the PBx date (dbPBx) and 30 to 90 dbPBx were significantly correlated with the .
View Article and Find Full Text PDFA metal- and base-free 5--trig sulfonylative cyclization between 1,5-dienes, aryldiazonium salts and SO (from SOgen) is presented. This method could successfully produce sulfonylated pyrrolin-2-ones in one pot with excellent regioselectivity and good-to-excellent yields. This strategy features mild reaction conditions and broad substrate scope.
View Article and Find Full Text PDFObjective: To evaluate the association between maternal influenza and congenital heart defects (CHDs), and whether the use of traditional Chinese medicine (TCM) or Western medicine (antibiotics, antipyretic-analgesic drugs) modified this association.
Method: We analysed 294 fetuses with CHDs and 416 control fetuses without any abnormalities identified from February 2010 through October 2011 in this hospital-based case-control study. Participating mothers were interviewed to determine whether they had been infected with "influenza" during the early pregnancy period or had used any medicine (TCM, Western medicine) to treat influenza.
Background: Congenital heart disease (CHD) is one of the most prevalent birth defects. Housing renovations are a newly recognized source of indoor environmental pollution that is detrimental to health. A growing body of research suggests that maternal occupational exposure to renovation materials may be associated with an increased risk of giving birth to fetuses with CHD.
View Article and Find Full Text PDFObjective: This study aims to evaluate the association between folic acid (FA) supplementation and congenital heart defects (CHDs).
Methods: This hospital-based case-control study initiated in 2010 in China analyzed 358 cases and 422 controls. The adjusted odds ratio (AOR) calculated using a logistic model was used to assess the association between FA supplementation and CHDs.
Background: Maternal deaths occur mostly in developing countries and the majority of them are preventable. This study analyzes changes in maternal mortality and related causes in Henan Province, China, between 1996 and 2009, in an attempt to provide a reliable basis for introducing effective interventions to reduce the maternal mortality ratio (MMR), part of the fifth Millennium Development Goal.
Methods And Findings: This population-based maternal mortality survey in Henan Province was carried out from 1996 to 2009.
Objective: To identify the immediate economic impact of maternal death on rural Chinese households.
Methods: Results are reported from a study that matched 195 households who had suffered a maternal death to 384 households that experienced a childbirth without maternal death in rural areas of three provinces in China, using quantitative questionnaire to compare differences of direct and indirect costs between two groups.
Findings: The direct costs of a maternal death were significantly higher than the costs of a childbirth without a maternal death (US$4,119 vs.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao
February 2011
Objective: To investigate the change of cardiac reserve during abnormal pregnancy and explore its evaluation methods.
Methods: Totally 96 women with abnormal pregnancies (AP group), 356 women with normal pregnancies (NP group), and 100 women of childbearing age (CBA group) were monitored by the exercise cardiac contractility monitor (ECCM). Phonocardiogram of participants at resting status was recorded by ECCM.
This paper describes a large resource of multi-center and multi-topic heart sound databases, which were based on the measured data from more than 9,000 heart sound samples (saved in WAV file format). According to different research topics, these samples were respectively stored in different folders (corresponding to different research topics and distributed over various cooperative research centers), most of which as subfolds were stored in a pooled folder in the principal center. According to different research topics, the measured data from these samples were used to create different databases.
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