Distribution, Sources, and Risk Assessment of Organochlorine Pesticides in Water from Beiluo River, Loess Plateau, China.

The Loess Plateau has been a focus of public discussion and environmental concerns over the past three decades. In this study, in order to investigate the effect of OCP pollution in water of the Beiluo River, concentrations of 25 OCPs at 17 locations in the water were examined. The results showed that the concentration of ∑OCPs in the water ranged from 1.76 to 32.57 ng L-1, with an average concentration of 7.23 ng L-1. Compared with other basins in China and abroad, the OCP content in the Beiluo River was at a medium level. Hexachlorocyclohexane (HCH) pollution in the Beiluo River was mainly from the mixed input of lindane and technical HCHs. Dichlorodiphenyltrichloroethane (DDT) pollution was mainly from the mixed input of technical DDTs and dicofol. Most of the OCP pollution came from historical residues. The risk assessment results showed that hexachlorobenzene (HCB) and endosulfan had high ecological risks in the middle and lower reaches of the Beiluo River. Most residual OCPs were not sufficient to pose carcinogenic and non-carcinogenic health risks to humans. The results of this study can provide a reference for OCP prevention and control and watershed environmental management.

Fingerprinting Evaluation and Gut Microbiota Regulation of Polysaccharides from Jujube (Ziziphus jujuba Mill.) Fruit.

Jujube fruit was well-loved and praised by the broad masses due to its delicious taste, abundant nutritional value, and medicinal properties. Few studies reported the quality evaluation and gut microbiota regulation effect of polysaccharides of jujube fruits from different producing areas. In the present study, multi-level fingerprint profiling, including polysaccharides, oligosaccharides, and monosaccharides, was established for the quality evaluation of polysaccharides from jujube fruits. For polysaccharides, the total content in jujube fruits ranged from 1.31% to 2.22%, and the molecular weight distribution (MWD) ranged from 1.14 × 105 to 1.73 × 106 Da. The MWD fingerprint profiling of polysaccharides from eight producing areas was similar, but the profile of infrared spectroscopy (IR) showed differentiation. The characteristic signals were screened and used to establish a discrimination model for the identification of jujube fruits from different areas, and the accuracy of identification reached 100.00%. For oligosaccharides, the main components were galacturonic acid polymers (DP, 2-4), and the profile of oligosaccharides exhibited high similarity. The monosaccharides, GalA, Glc, and Ara, were the primary monosaccharides. Although the fingerprint of monosaccharides was semblable, the composing proportion of monosaccharides revealed significant differences. In addition, the polysaccharides of jujube fruits could regulate the gut microbiota composition and possess potential therapeutic effects on dysentery and nervous system diseases.

Fingerprint profiling and gut microbiota regulation of polysaccharides from Fritillaria species.

Few studies reported the quality evaluation and gut microbiota regulation effect of polysaccharides from Fritillaria species. In this study, polysaccharides extracted from ten Fritillaria species were compared and distinguished through multi-levels evaluation strategy and data fusion. Furthermore, the gut microbiota regulation effect of polysaccharides among different species was analyzed and evaluated. The fingerprint profiling of IR, molecular weight distribution of polysaccharides, chromatogram of partially hydrolyzed polysaccharides (oligosaccharides) and completely hydrolyzed polysaccharides (monosaccharides) were similar, and no exclusive signals were observed. However, the signal strength of functional group, oligosaccharides abundance and monosaccharides proportion showed obvious differences in inter- and intra-species. Glucan may be the main component of polysaccharides in Fritillaria species, CIRR derived from CIR, PRZ, DEL, TAI, UNI possessed higher total polysaccharides content, polymerization degree, oligosaccharides abundance (DP 2-4), and glucose content than the others. Meanwhile, data fusion model was established for identification of affinis and multi-original species, the accuracy of which proved to be 100 %. In addition, Fritillaria polysaccharides could increase the bacterial community richness and diversity, regulate the gut microbiota composition and possessed potential therapeutic effects on gastrointestinal diseases and nervous system diseases.

A stable and sensitive Au metal organic frameworks resonance Rayleigh scattering nanoprobe for detection of SO3 2- in food based on fuchsin addition reaction.

A stable Au metal organic frameworks (AuMOF) nanosol was prepared. It was characterized by electron microscopy and molecular spectral techniques. In pH 6.8 PBS buffer solution, AuMOF nanoprobes exhibit a strong resonance Rayleigh scattering (RRS) peak at 330 nm. After basic fuchsin (BF) adsorbing on the surface of AuMOF, the RRS energy of the nanoprobe donor can be transferred to BF receptor, resulting in a decrease in the RRS intensity at 330 nm. Both sulfite and BF taken place an addition reaction to form a colorless product (SBF) that exhibit weak RRS energy transfer (RRS-ET) between AuMOF and SBF, resulting in the enhancement of the RRS peak. As the concentration of SO3 2-increases, the RRS peak is linearly enhanced. Thus, a new and sensitive RRS-ET method for the detection of SO3 2- (0.160-5.00 µmol/L) was developed accordingly using AuMOF as nanoprobes, with a detection limit of 0.0800 µmol/L. This new RRS method was applied to determination of SO3 2- in food and SO2 in air samples. The recoveries of food and air samples were 97.1-106% and 92.9-106%, and the relative standard deviation (RSD) was 2.10-4.80% and 2.10-4.50%, respectively.

Effect of rhamnolipids on the biodegradation of m-dichlorobenzene in biotrickling filters: Performance and mechanism.

In this study, the effect of rhamnolipids (RL) on m-dichlorobenzene (m-DCB) removal and biofilm was investigated in two biotrickling filters (BTF) (BTF1: blank control; BTF2: RL addition). The critical micelle concentration (CMC) value of RL was 75.6 mg L-1, and the RL could significantly improve the solubilization of m-DCB. The results showed that the optimal concentration of RL was 180 mg L-1. The removal efficiency (RE) of m-DCB dropped by 42.4% for BTF1 no fed with RL and only 28.2% for BTF2 fed with RL when the inlet concentration increased from 200 to 1400 mg m-3 at an empty bed time (EBRT) of 60 s. RL increased the secretion of extracellular polymers (EPS) and the ratio of Protein/Polysaccharide, which improved the mass transfer of m-DCB to the biofilm. RL also had a facilitating effect on catechol-1,2-dioxygenase (C12O) enzyme activity. Furthermore, RL increased Zeta potential and facilitated microorganisms to form biofilm. The dominant microorganisms of microbial community were increased and the application of RL promoted the enrichment of them.

Microscopic analysis of "iron spot" on blue-and-white porcelain from Jingdezhen imperial kiln in early Ming dynasty (14th-15th century).

"Sumali," as an imported cobalt ore from overseas, was a sort of precious and valuable pigment used for imperial kilns only, which produces characteristic "iron spot" to blue-and-white porcelain in early Ming Dynasty (A.D. 14th-15th century). Although there were some old studies on it, the morphology and formation of iron spot has not been fully investigated and understood. Therefore, five selected samples with typical spot from Jingdezhen imperial kiln in Ming Yongle periods (A.D. 1403-1424) were analyzed by various microscopic analysis including 3D digital microscope, SEM-EDS and EPMA. According to SEM images, samples can be divided into three groups: un-reflected "iron spot" without crystals, un-reflected "iron spot" with crystals and reflected "iron spot" with crystals. Furthermore, 3D micro-images revealed that "iron spots" separate out dendritic or snow-shaped crystals of iron only on and parallel to the surface of glaze for which "iron spot" show strong metallic luster. Combining with microscopic observation and microanalysis on crystallization and non-crystallization areas, it indicates that firing oxygen concentration is the ultimate causation of forming reflective iron spot which has a shallower distribution below the surface and limits crystals growing down. More details about characters of "iron spot" used "Sumali" were found and provided new clues to coloration, formation mechanism and porcelain producing technology of imperial kiln from 14th to 15th centuries of China.