Polar and hydrogen-bonding effects of alcohols on the emission spectrum of styrene-triethylamine system

The emission spectra of styrene (ST)-triethylamine (TEA) systems were measured under steady-state illumination conditions in some THF-protic solvent mixtures. The fluorescence spectrum of the ST-TEA system in THF consists of two bands (band A at 304 nm (fluorescence of ST) and band B at 460 nm (emission from an exciplex)). The intensity of band A increased and that of band B decreased with increasing amounts of protic solvents in THF-protic solvent mixtures. The increase in the intensity of band A was explained by the decrease in the concentration of free amine owing to the hydrogen-bonding interaction (or protonation) between TEA and protic solvents. The decrease in the intensity of band B was considered to be caused by the decrease in the concentration of free amine on the addition of protic solvents and the enhanced conversion of the exciplex to an ion pair with increasing solvent polarity. The polar effect was expressed as a function of the relative permittivity of the solution.</p

Polar and hydrogen-bonding effects of alcohols on the emission spectrum of styrene-triethylamine system Polar and Hydrogen-Bonding Effects of Alcohols on the Emission Spectrum of Styrene-Triethylamine System

The emission spectra of styrene (ST)-triethylamine (TEA) systems were measured under steady-state illumination conditions in some tetrahydrofuran (THF)-protic solvent mixtures. The fluorescence spectrum of the ST-TEA system in THF consists of two bands (band A at 304 nm (fluorescence of ST) and band B at 460 nm (emission from an exciplex)). The intensity of band A increased and that of band B decreased with increasing amounts of protic solvents in THF-protic solvent mixtures. The increase in the intensity of band A was explained by the decrease in the concentration of free amine owing to the hydrogen-bonding interaction (or protonation) between TEA and protic solvents. The decrease in the intensity of band B was considered to be caused by the decrease in the concentration of free amine upon the addition of protic solvents and the enhanced conversion of the exciplex to an ion pair with increasing solvent polarity. The polar effect was expressed as a function of the relative permittivity of the solution

Degenerate Fubini-Type Polynomials and Numbers, Degenerate Apostol–Bernoulli Polynomials and Numbers, and Degenerate Apostol–Euler Polynomials and Numbers

In this paper, by introducing degenerate Fubini-type polynomials, with the help of the Faà di Bruno formula and some properties of partial Bell polynomials, the authors provide several new explicit formulas and recurrence relations for Fubini-type polynomials and numbers, associate the newly defined degenerate Fubini-type polynomials with degenerate Apostol–Bernoulli polynomials and degenerate Apostol–Euler polynomials of order α. These results enable one to present additional relations for some degenerate special polynomials and numbers

Degenerate Fubini-Type Polynomials and Numbers, Degenerate Apostol&ndash;Bernoulli Polynomials and Numbers, and Degenerate Apostol&ndash;Euler Polynomials and Numbers

In this paper, by introducing degenerate Fubini-type polynomials, with the help of the Fa&agrave; di Bruno formula and some properties of partial Bell polynomials, the authors provide several new explicit formulas and recurrence relations for Fubini-type polynomials and numbers, associate the newly defined degenerate Fubini-type polynomials with degenerate Apostol&ndash;Bernoulli polynomials and degenerate Apostol&ndash;Euler polynomials of order &alpha;. These results enable one to present additional relations for some degenerate special polynomials and numbers

Prevalence of birth defects and risk-factor analysis from a population-based survey in Inner Mongolia, China

<p>Abstract</p> <p>Background</p> <p>Birth Defects are a series of diseases that seriously affect children's health. Birth defects are generally caused by several interrelated factors. The aims of the article is to estimate the prevalence rate and types of birth defects in Inner Mongolia, China, to compare socio-demographic characteristics among the children with birth defects and to analyze the association between risk factors and birth defects.</p> <p>Methods</p> <p>Data used in this study were obtained through baseline survey of Inner Mongolia Birth Defects Program, a population-based survey conducted from 2005 to 2008. The survey used cluster sampling method in all 12 administrative districts of Inner Mongolia. Sampling size is calculated according to local population size at a certain percentage. All live births, stillbirths and abortions born from October 2005 to September 2008, whose families lived in Inner Mongolia at least one year, were included. The cases of birth defects were diagnosed by the clinical doctors according to their experiences with further laboratory tests if needed. The inclusion criteria of the cases that had already dead were decided according to death records available at local cites. We calculated prevalence rate and 95% confidence intervals of different groups. Outcome variable was the occurrence of birth defects and associations between risk factors and birth defects were analyzed by using Poisson regression analysis.</p> <p>Results</p> <p>976 children with birth defects were diagnosed. The prevalence rate of birth defects was 156.1 per 10000 births (95%CI: 146.3-165.8). The prevalence rate of neural tube defect (20.1 per 10000 births) including anencephaly(6.9 per 10000), spina bifida (10.6 per 10000), and encephalocele (2.7 per 10000) was the highest, followed by congenital heart disease (17.1 per 10000). The relative risk (RR) for maternal age less than 25 was 2.22 (95%CI: 2.05, 2.41). The RR of the ethnic Mongols was lower than Han Chinese (RR: 0.84; 95%CI: 0.80-0.89). The RR of the third and second pregnancy was significantly higher than the first pregnancy while a slight difference between the second and the first pregnancy was also found. Alcohol drinking of mothers, familial inheritance and living area were also found to be related to the occurrence of the birth defects.</p> <p>Conclusions</p> <p>Relatively higher birth defect rates were found in Inner Mongolia. This study found that maternal age less than 25, alcohol drinking, familiar inheritance, lower education level of mothers, times of pregnancies and living in rural areas may increase the risk of birth defects. Ethnic Mongols were less likely to have birth defects than Han Chinese.</p