Mechanochemical Vicinal Dibromination of Unactivated Alkenes and Alkynes Using Piezoelectric Material as a Redox Catalyst.

Mechanoredox 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 (Li2TiO3) 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 Li2TiO3 can be reused multiple times without a structural change.

Mechanochemical Synthesis of Aryl Fluorides by Using Ball Milling and a Piezoelectric Material as the Redox Catalyst.

Aryl 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. This approach effectively addresses the aforementioned limitations. Furthermore, the piezoelectric material can be recycled multiple times. Mechanistic investigations indicate that this fluorination reaction may proceed via a radical pathway, and Selectfluor plays a dual role as both a source of fluorine and a terminal reductant.

Development of Two Early Forecasting Models for Predicting Incidence of Rice Panicle Blast in China.

Early 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 (PBx) and the PBx in the preceding crop, weather conditions, location, and acreage of susceptible varieties was analyzed. Results revealed that PBx in the preceding crop, acreage of the susceptible varieties in class (SVC), altitude, weather conditions 120 to 180 days before the PBx date (dbPBx) and 30 to 90 dbPBx were significantly correlated with the PBx. Subsequently, a logistic model and a two-step hurdle model were developed to predict rice panicle blast. The logistic model was developed to predict whether the PBx was 0 or not based on the preceding PBx, altitude, acreage of susceptible varieties, the longest stretch of days with soil temperatures between 16 and 24°C for the period 120 to 150 dbPBx, and the longest stretch of rainy days in the period 120 to 180 dbPBx. The hurdle model predicted if the PBx was greater than 0 at the first step, and if the prediction was greater than 0, then a regression model was developed for predicting PBx based on the preceding PBx, SVC, altitude, and weather data 180 to 30 dbPBx. Validation with the test datasets showed that the logistic model could correctly predict whether PBx was 0 at a mean test accuracy of 78.39% and that the absolute prediction error of PBx by the two-step hurdle model was smaller than 6.16% for 90% of the records. The model developed in this study will be helpful in management decisions for rice growers and policy makers and offer a useful basis for further studies on the epidemiology and forecasting of rice panicle blast.

Metal- and base-free tandem sulfonylation/cyclization of 1,5-dienes with aryldiazonium salts via the insertion of sulfur dioxide.

A metal- and base-free 5-endo-trig sulfonylative cyclization between 1,5-dienes, aryldiazonium salts and SO2 (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. Moreover, a scale-up reaction and three synthetic applications demonstrate the practicality of this method. Lastly, control experiments indicate that the 5-endo-trig sulfonylative cyclization may proceed in a radical pathway.

Maternal influenza-like illness, medication use during pregnancy and risk of congenital heart defects in offspring.

OBJECTIVE: 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. A logistic regression model was used to calculate ORs and 95% CIs while controlling for potential confounders. RESULTS: There were significant associations between maternal influenza and CHDs in the aggregate (AOR, 1.60; 95%CI, 1.12 to 2.28) and specific subtypes, namely septal defects (AOR, 2.12; 95%CI, 1.38 to 3.26) and conotruncal defects (AOR, 1.60; 95%CI, 1.01 to 2.51). Maternal medication use (i.e. TCM or Western medicine) in the setting of influenza tended to decrease these associations. CONCLUSIONS: Maternal influenza during second-third months of pregnancy increased the risk for CHDs, with septal defects and conotruncal defects in particular being observed. The use of medication for influenza might attenuate such associations.

Association between maternal exposure to housing renovation and offspring with congenital heart disease: a multi-hospital case-control study.

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. However, the effect of indoor housing renovation exposure on CHD occurrence has not been reported. METHODS: A multi-hospital case-control study was designed to investigate the association between maternal periconceptional housing renovation exposure and the risk of CHD for offspring. In total, 346 cases and 408 controls were enrolled in this study from four hospitals in China. Exposure information was based on a questionnaire given to women during pregnancy. The association between housing renovation exposure and CHD occurrence was assessed by estimating odds ratios (OR) with logistic regression models adjusted for potential confounders. RESULTS: The risk for CHD in offspring was significantly associated with maternal exposure to housing renovations (AOR: 1.89, 95% CI: 1.29-2.77). There were similar risks for cardiac defects with or without extra-cardiac malformation (AOR of 2.65 and 1.76, respectively). Maternal housing renovation exposure may increase the fetus' risk of suffering from conotruncal defect or anomalous venous return. There were significant risks for cardiac defects if the pregnant woman moved into a new house within one month after decoration at either 3 months before pregnancy (AOR: 2.38, 95% CI: 1.03 to 5.48) or during first trimester (AOR: 4.00, 95% CI: 1.62 to 9.86). CONCLUSIONS: Maternal exposure to housing renovations may have an increased risk of giving birth to fetuses with some selected types of CHD. This relationship was stronger for women who moved into a newly decorated house. However, considering the limited number of subjects and the problem of multiple exposures, more research is needed to clarify the effects seen here.

The association between periconceptional folic acid supplementation and congenital heart defects: a case-control study in China.

OBJECTIVE: 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. RESULTS: Compared with a mother who reported no FA supplementation, mothers who reported FA supplementation were less likely to have offspring with isolated CHD(s) (AOR=0.52, 0.34-0.78) and multiple complex conditions (AOR=0.27, 0.14-0.55). However, mothers who reported FA supplementation for less than 1 month regardless of the start time of supplementation, did not have a significantly lower risk of having an offspring with isolated or multiple complex conditions. Mothers who reported FA supplementation for ≧3 months beginning before conception had a significantly lower risk of having children with isolated CHD(s) (AOR=0.31, 0.18-0.54). CONCLUSION: FA-supplementation is associated with reduced risk of CHDs. The earlier FA supplementation begins before pregnancy and the longer supplementation lasts, the lower the risk of CHDs is.

Maternal mortality in Henan Province, China: changes between 1996 and 2009.

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. Basic information was obtained from the health care network for women and children and the vital statistics system, from specially trained monitoring personnel in 25 selected monitoring sites and by household survey in each case of maternal death. This data was subsequently reported to the Henan Provincial Maternal and Child Healthcare Hospital. The total MMR in Henan Province declined by 78.4%, from 80.1 per 100 000 live births in 1996 to 17.3 per 100 000 live births in 2009. The decline was more pronounced in rural than in urban areas. The most common causes of maternal death during this period were obstetric hemorrhage (43.8%), pregnancy-induced hypertension (15.8%), amniotic fluid embolism (13.9%) and heart disease (8.0%). The MMR was higher in rural areas with lower income, less education and poorer health care. CONCLUSION: There was a remarkable decrease in the MMR in Henan Province between 1996 and 2009 mainly in the rural areas and MMR due to direct obstetric causes such as obstetric hemorrhage. This study indicates that improving the health care network for women, training of obstetric staff at basic-level units, promoting maternal education, and increasing household income are important interventional strategies to reduce the MMR further.

The immediate economic impact of maternal deaths on rural Chinese households.

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. $370, p<0.001). More than 40% of the direct costs were attributed to funeral expenses. Hospitalization and emergency care expenses were the largest proportion of non-funeral direct costs and were higher in households with maternal death than the comparison group (US$2,248 vs. $305, p<0.001). To cover most of the high direct costs, 44.1% of affected households utilized compensation from hospitals, and the rest affected households (55.9%) utilized borrowing money or taking loans as major source of money to offset direct costs. The median economic burden of the direct (and non-reimbursed) costs of a maternal death was quite high--37.0% of the household's annual income, which was approximately 4 times as high as the threshold for an expense being considered catastrophic. CONCLUSION: The immediate direct costs of maternal deaths are extremely catastrophic for the rural Chinese households in three provinces studied.

Multi-center, multi-topic heart sound databases and their applications.

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. Relevant data for a specific topic can be pooled in a large database for further analysis. This resource is shared by members of related centers for their own specific topic. The applications of this resource include evaluation of cardiac safety of pregnant women, evaluation of cardiac reserve for children, athletes, addicts, astronauts, and general populations, as well as studies on a bedside method for evaluating cardiac energy, reversal of S1-S2 ratio, etc.

Change of cardiac reserve during abnormal pregnancy and its evaluation / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the change of cardiac reserve during abnormal pregnancy and explore its evaluation methods.</p><p><b>METHODS</b>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. The amplitude of first heart sound (S1), the amplitude of second heart sound (S2), cardiac cycle, diastolic duration (D), and systolic duration (S) were detected and then the S1/S2 ratio,the D/S ratio, and heart rate (HR) were calculated.</p><p><b>RESULTS</b>Compared with the CBA group, S1/S2 ratio and HR were significantly higher and D/S was significantly lower in both AP group and NP group (all P<0.001). Compared with the NP group, S1/S2 ratio and HR were significantly higher in AP group and D/S was significnatly lower (all P<0.001). A D/S ratio less than 1.1 or S1/S2 ratio higher than 1.8 was associated with higher risk of poor pregnancy outcomes. Among four common pregnancy-associated abnormalities, the level of cardiac reserve was lowest in eclampsia, followed by twins, gestational diabetes mellitus, and gestational hypertension.</p><p><b>CONCLUSIONS</b>Cardiac reserve is mobilized during pregnancy, and is especially during the abnormal pregnancies due to the heavy cardiac burden. S1/S2 ratio, D/S ratio, and HR are useful in evaluating the cardiac reserve during abnormal pregnancy.</p>