Detection of carbofuran in fruits and vegetables by Raman spectroscopy combined with immunochromatography.

It has long been desired to develop rapid methods for the rapid identification and quantification of pesticides and their metabolites. Carbofuran, a representative pesticide of the carbamate group, is highly systemic and is used on vegetables, fruits and grains, which has led many countries to test for residues in food and the environment. In this study, gold and silver composite core-shell (Au@Ag) nanoparticles were used to label the carbofuran antibody and Raman molecule 5,5-dithiobis-2-nitrobenzoic acid (DTNB) to synthesize Raman immune probes. The signal value of DTNB was read using a Raman spectrometer, and the quantitative detection technology of carbofuran was established based on lateral flow immunochromatographic assay (ICA) combined with surface-enhanced Raman spectroscopy (SERS). SERS-ICA is a rapid, quantitative and ultrasensitive test for the determination of carbofuran in fruits and vegetables with a sensitivity of 0.1 pg mL-1. Consequently, the results demonstrate that the SERS-based lateral flow immunosensor developed in this study has the advantages of excellent assay sensitivity and remarkable multiplexing capability, and thus it will have great application potential in food safety monitoring.

Prevalence of disability in an arsenic exposure area in Inner Mongolia, China.

UNLABELLED: Long term exposure to arsenic can cause adverse health effects and lead to different levels of disability. The prevalence of arsenical dermatosis is as high as 40% in the Hetao Plain area of Inner Mongolia, but the association between exposure to arsenic in drinking water and the occurrence of disability has not yet been fully examined. The aim of this study was to investigate the prevalence of disability in arsenic-affected villages in Inner Mongolia, China. METHODS: A cross-sectional study was performed to examine the prevalence of disability. A total of 320 villagers in the age range of 20-39 years were interviewed and examined for disability and arsenical skin lesions. The subjects were classified into a high arsenic group (50 microg L(-1)) and a low arsenic group (<50 microg L(-1)). The relationship between levels of arsenic in drinking water and disability was analyzed using multivariate logistic regression models to estimate the odds ratios and 95% confidence intervals. RESULTS: The prevalence of disability was 6.88% in the arsenic affected area of Inner Mongolia and 24.72% in the arsenic group 50 microg L(-1). A strong correlation was found between disability and arsenical skin lesions (OR=86.39, 95%CI: 25.45-293.20). CONCLUSION: This suggests that the level of arsenic exposure is a major risk factor for disability. Further research is needed to place the results in a wider context and to determine the exact relationship between arsenic exposure and disability.

Dielectric barrier discharge plasma as a novel approach for improving 1,3-propanediol production in Klebsiella pneumoniae.

Dielectric barrier discharge plasma was used to generate a stable strain of Klebsiella pneumoniae (designated to as Kp-M2) with improved 1,3-propanediol production. The specific activities of glycerol dehydrogenase, glycerol dehydratase and 1,3-propanediol oxidoreductase in the crude cell extract increased from 0.11, 9.2 and 0.15 U mg(-1), respectively, for wild type to 0.67, 14.4 and 1.6 U mg(-1) for Kp-M2. The glycerol flux of Kp-M2 was redistributed with the flux to the reductive pathway being increased by 20% in batch fermentation. The final 1,3-propanediol concentrations achieved by Kp-M2 in batch and fed-batch fermentations were 19.9 and 76.7 g l(-1), respectively, which were higher than those of wild type (16.2 and 49.2 g l(-1)). The results suggested that dielectric barrier discharge plasma could be used as an effective approach to improve 1,3-propanediol production in K. pneumoniae.

[Study of radicals in pulsed corona discharge by emission spectroscopy].

The emission spectra of OH(A2 sigma --> X2 pi, O-O), O(3p5 P --> 3s5 S2(0)) and H(a)(3P --> 2S) produced by the positive pulsed corona discharge of N2 and H2O mixture in a needle-plate reactor have been successfully recorded against a severe electromagnetic interference coming from the pulsed corona discharge at one atmosphere. The relative populations and the vibrational temperature of N2 (C, v') were determined. The emission intensity of OH(A2 sigma --> X2 pi, 0-0) is obtained through the simulation of the emission spectra of the delta v = +1 vibration transition band of N2(C3 pi(u) --> B3 pi(g)). Relative populations of OH(A2 sigma), O(3p5 P) and H(a)(3P) have been obtained by the emission intensity of OH(A2 sigma --> X2 pi, 0-0), O(3p5 P --> 3s5 S2(0)) and H(a)(3P --> 2S) and Einstein's transition probability. The effects of discharge voltage and pulse repetition rate and oxygen flow on the relative populations of OH(A2 sigma), O(3p5 P) and H(a)(3P) are investigated.