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Egg production is an important economic trait in layer ducks and understanding the genetics basis is important for their breeding. In this study, a genome-wide association study (GWAS) for egg production traits in 303 female Longyan Shan-ma ducks was performed based on a genotyping-by-sequencing strategy. Sixty-two single nucleotide polymorphisms (SNPs) associated with egg weight traits were identified (P< 9.48 × 10-5), including 8 SNPs at 5% linkage disequilibrium (LD)-based Bonferroni-corrected genome-wide significance level (P< 4.74 × 10-6). One hundred and nineteen SNPs were associated with egg number traits (P< 9.48 × 10-5), including 13 SNPs with 5% LD-based Bonferroni-corrected genome-wide significance (P< 4.74 × 10-6). These SNPs annotated 146 target genes which contained known candidate genes for egg production traits, such as prolactin and prolactin releasing hormone receptor. This study identified that these associated genes were significantly enriched in egg production-related pathways (P< 0.05), such as the oxytocin signaling, MAPK signaling, and calcium signaling pathways. It was notable that 18 genes were differentially expressed in ovarian tissues between higher and lower egg production in Shan-ma ducks. The identified potential candidate genes and pathways provide insight into the genetic basis underlying the egg production trait of layer ducks.

Sulfites are used widely in food and beverage production to prevent browning or oxidation. However, the overingestion of sulfites is harmful to human health and may cause medical complications. Chinese herbal teas have been widely consumed for centuries. However, sulfite levels in Chinese herbal teas are rarely investigated and reported. Here, we present a simple, sensitive, and quantitative method to determine sulfites in Chinese herbal teas using ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) coupled with dispersive solid phase extraction. The method utilized a SeQuant ZIC-HILIC column for separation, and the optimal gradient eluents consisted of acetonitrile and aqueous solution with 0.1% acetic acid and 10 mM ammonium acetate. Porous chitosan/partially reduced graphene oxide/diatomite (CS/prGO/DM) composites were used as efficient dispersive solid phase extraction adsorbents for sample preparation. Several parameters were investigated during the extraction process, including sample-to-extraction solvent volume ratios, the extraction procedure and dosage of the adsorbent. Under the optimum conditions, the developed method gave a good determination coefficient (r2> 0.99), low detection limits (0.51–12.1 μg kg−1) and high recoveries in the range of 83.8–102.7% at different spiked levels. The method has the great advantages of being time saving, good reproducibility and much lower detection limits when compared to titration methods. The method was further applied to analyze real herbal tea samples collected from the local market, demonstrating that our developed method is robust and useful for determining sulfites in practical application.

Polymethoxyflavones (PMFs) are a subgroup of flavonoids possessing various health benefits. 3,5,7,4′-Tetramethoxyflavone (1), 5,6,7,4′-tetramethylflavone (2), 3,7,3′,4′-tetramethoxyflavone (3), 5,7,3′,4′-tetramethoxyflavone (4), 5-hydroxy-3,7,2′,4′-tetramethoxyflavone (5), 3,5,7,2′,4′-pentamethoxyflavone (6), 5-hydroxy-3,7,3′,4′-tetramethoxyflavone (7), 3-hydroxy-5,7,3′,4′-tetramethylflavone (8), 3,5,7,3′,4′-pentamethoxyflavone (9), 5-hydroxy-3,7,3′,4′,5′-pentamethoxyflavone (10), 3-hydroxy-5,7,3′,4′,5′-pentamethoxyflavone (11), and 3,5,7,3′,4′,5′-hexamethoxylflavone (12) were 12 bioactive and available PMFs. The aim of this study was to investigate the pharmacokinetic, metabolite, and antitumor activities as well as the structure–pharmacokinetic–antitumor activity relationships of these 12 PMFs to facilitate further studies of their medicinal potentials. The cytotoxicity of PMFs with a hydroxy group toward HeLa, A549, HepG2, and HCT116 cancer cell lines was generally significantly more potent than that of PMFs without a hydroxy group. Compounds 5, 7, 8, 10, and 11were all undetectable in rat plasma, while compounds 1–4, 6, 9, and 12were detectable. Both the number and position of hydroxy and methoxy groups played an important role in modulating PMF pharmacokinetics and metabolites.

Flavin-dependent halogenases (FDHs) are well known to introduce carbon halide bonds (mainly C-Cl and C-Br) into natural products with the assistance of a partner protein flavin reductase to generate reduced flavin (FADH2or FMNH2). Compared with the common chloride- and bromide-containing natural products (approximately 5,000 compounds), iodinated natural products (approximately 100 compounds) are very limited. Specific iodinases have also rarely been identified in nature to date. This study discovered a novel relationship between iodination and flavin reductases for the first time. Through mechanistic studies, it was identified that peroxide (H2O2) was released from the uncoupling reaction of flavin reductases and then reacted with iodide ions (I−) to produce hypoiodous acid (IOH) for the final iodination. Furthermore, this study also unintentionally verified that the recently reported flavin-dependent iodinase VirX1 from the marine virus and its two homologs (MBG and NCV) did not catalyze iodination in the in vitrobiochemical system but likely belonged to a new phylogenetic clade in the tryptophan halogenase superfamily. As a consequence, actual flavin-dependent iodinases in nature remain to be discovered by the scientific community in the future.

AbstractSynaptic plasticity plays an important role in learning and memory in the developing hippocampus. However, the precise molecular mechanism in lead exposure models remains to be studied. UCP2, an inner mitochondrial anion carrier, regulates synaptic plasticity through uncoupling neurons. And hnRNP K, an RNA binding protein, plays a role in modulating the expression of transcripts coding synaptic plasticity. We aim to investigate whether lead exposure affects UCP2 and hnRNP K expression levels. The Sprague-Dawley rats were exposed to different lead acetate concentrations (0 g/l, 0.5 g/l, 2.0 g/l) during gestational and lactational periods. PC12 cells were also exposed to different lead acetate concentrations (0 μM, 1 μM and 100 μM). We found that the expression levels of UCP2 and hnRNP K had significant declines in the lead exposure rat hippocampus and PC12 cells. Furthermore, the up-regulation of hnRNP K expression level could reverse the expression level of UCP2 in lead exposure models. In conclusion, these results suggest that lead exposure can reduce the expression level of UCP2 which is mediated by decreasing the expression level of hnRNP K.

As a widely used plant growth regulator, the gibberellic acid (GA3) residue in tea has potential risk for human health. Herein, the degradation of GA3and its conversion into main metabolites were investigated during tea planting, manufacturing, and brewing using ultrahigh-performance liquid chromatography tandem mass spectrometry. The metabolite iso-GA3was first discovered during the tea production chain and identified using Q-Exactive Orbitrap mass spectrometry. GA3dissipated following first-order kinetics in tea shoots with half-lives ranging from 2.46 to 2.74 days. It was degraded into iso-GA3in tea shoots, which had a longer residual period than GA3. Meanwhile, external application of GA3could increase the proportion of growth-promoting endogenous phytohormones and lead to rapid growth of tea plants. During tea manufacturing, iso-GA3was quickly and massively converted from GA3. Fixing (heat at 220–230 °C) played an important role in the dissipation of GA3and iso-GA3during green tea manufacturing, but there were high residues of iso-GA3in black tea. High transfer rates (77.3 to 94.5%) of GA3and iso-GA3were observed during tea brewing. These results could provide a practical reference for food safety in tea and other agricultural products and the guidance for scientific application of GA3in tea planting.

The spectroscopy of surface-enhanced Raman scattering (SERS), with its high sensitivity and specific chemical fingerprinting, has received increasing attention. A stable substrate is extraordinarily important for the trace detection of the SERS technique, but the challenge of SERS substrate production with high stability and uniformity still imposes the unavoidable barriers. In this paper, we design a multilayer core–shell-nanostructured ZrO2@Ag@SiO2nanoparticle through liquid extraction. First, we regulated the usage of AgNO3(1 wt %) to obtain Ag@SiO2which is silver coated with uniform distribution; on the surface of silica, the number of silver particles is abundant. Then, we discussed the influence when different concentrations of zirconium propoxide are added on the zirconia layer’s thickness. Then, we applied FDTD simulation to explain the position of SERS “hotpots” with and without ZrO2coating. We have found that the detection capability of ZrO2@Ag@SiO2can be up to 10–9M for 4-ATP; with ZrO2@Ag@SiO2SERS substrates exposed to the atmospheric environment for up to 30 days, we could still obtain the excellent SERS signal performance contributed by the good chemical stability of ZrO2, when ZrO2is coated on the surface of Ag@SiO2, the zirconia layer formed has a protective role . These experimental results have indicated that the outer zirconia layer could prevent the silver surface from being oxidized, ensuring its stability , which is quite crucial for the applied SERS.

In order to accelerate the development of the sports industry in China, the State Council requires the "better play of the role of the government". The economic development since the reform and opening up has proved that "intergovernmental relations" have a crucial impact on the role of the government. As the embodiment of "intergovernmental relations" in the development of sports industry, the development competition of local sports industry will largely influence the development speed and quality of China's future sports industry. Competition can generate multiple positive values, including promoting innovation, optimizing the industrial structure, and creating a friendly development environment. On the other hand, practice shows that competition has brought about many negative effects such as excessive government intervention and weakening of market mechanisms, isomorphic development and excessive competition, local protectionism and unfair competition. The key to exerting the positive value of competition in the sports industry and suppressing its negative influence is to establish a benign competitive order, including rationally exerting the role of the government, promoting differentiated development, and establishing sports industry cooperation between local governments. [ABSTRACT FROM AUTHOR]

Perchlorate is an environmental contaminant interrupting thyroid hormone production, and perchlorate in tea has raised wide concern recently. In this study, an accurate method was developed for the determination of perchlorate in tea using hydrophilic interaction chromatography-tandem mass spectrometry and a simplified QuEChERS procedure. The method utilized a zwitterion HILIC column for separation, and the optimal gradient eluents consisted of acetonitrile and aqueous solution with 0.1% formic acid and 20 mmol L−1ammonium formate. Calibration curves were fitted by the quadratic model with 1/xweight instead of the linear model. As perchlorate was only partially extractable when using acetonitrile or methanol as the extraction solvent, acetonitrile/water (1 : 1, v/v) was chosen to extract perchlorate from tea samples. Graphitized carbon black was used as the dispersive solid phase extraction sorbent to clean up tea extracts. The method exhibited satisfactory accuracy with recoveries of 81.4–100.9% and relative standard deviations of 1.3–14.5% for green and black teas. The limit of quantitation was 0.005 mg kg−1, while the limits of detection were 0.0011 mg kg−1for green tea and 0.0013 mg kg−1for black tea, indicating an excellent sensitivity of this method. A 100% positive rate of perchlorate was found in 100 real tea samples, and the concentrations ranged from 0.0030 mg kg−1to 0.78 mg kg−1. This accurate, sensitive and rapid method would be suitable for monitoring, risk assessment and source identification of perchlorate in tea.

TiO2is modified by Fe-doping reduction method to regulate the pore structure of TiO2. When the Fe/Ti molar ratio of 0.05, the Fe–Mn/TiO2(0.05Fe) catalyst shows an almost 100% NO conversion and N2selectivity in the range of 170–250 °C. The catalyst exhibits a catalytic activity above 95% even in the presence of SO2and water. The N2adsorption–desorption, XRD, H2-TPR, XPS, TG and TEM are used to characterize the catalysts. The results show that the modification of Fe in the TiO2carrier enlarges the catalysts’ BET surface area, increases the proportion of the high valence states of Mn on the surface, and promotes more defect of the lattice oxygen, and makes TiO2be coated and protected. All these modification keeps the catalyst having a high and stable SCR activity and sulfur and water resistance at low temperature.

The increasingly widespread usage of silver (Ag) nanoparticles has raised concerns regarding their environmental risk. The behavior of Ag and its transfer risk to the food chain were investigated using a long-term field experiment that commenced in 1942 in which Ag-containing sewage sludge was repeatedly applied to the soil (25 applications during 20 years). The speciation of the Ag in both the sludge and the soils retrieved from the long-term experimental archive was examined using synchrotron-based X-ray absorption spectroscopy, and extractable Ag concentrations from soils were determined using 0.01 M Ca(NO3)2and 0.005 M DTPA. The total Ag in the sludge during the time period of 1942–1961 ranged from 155 to 463 mg kg–1. These values are 1–2 orders of magnitude higher than those in currently produced sludge (ca. 0.5–20 mg kg–1). Long-term repeated applications of these sludges resulted in an increase of Ag in soils from 1.9 mg kg–1in the control to up to 51 mg kg–1. The majority (>80%) of the Ag in both the sludge and the sludge-treated soils was present as insoluble Ag2S, thereby markedly reducing the bioavailability of this Ag. Concentrations of Ag in the archived crop samples were generally <0.70 mg kg–1in edible tissues, much less than those in diets that may cause an adverse effects in animals and humans (>100 mg kg–1). These data indicate that the transfer of Ag (derived from both traditional Ag industry and current nano Ag industry) to the terrestrial food chain is limited.

A rapid and sensitive method for the simultaneous determination of bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in tea using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. Sample preparation was based on a modified QuEChERS procedure through extraction of the target analytes using acetonitrile with 0.7% acetic acid followed by a dispersive solid phase extraction (d-SPE) clean up procedure using C18, MWCNTs and SCX as the adsorbent mixture to eliminate tea co-extracts. The linearity of the method with correlation coefficients (R2) higher than 0.99 was obtained. The limits of detection (LODs), and limits of quantitation (LOQs) were 8.0 and 20.0 μg kg−1for BPA and 0.4 and 1.0 μg kg−1for TBBPA, respectively. Satisfactory mean recoveries of BPA and TBBPA at three fortification levels ranged from 88% to 109% and 77% to 99%, respectively, while intra-day and inter-day precisions were below 15%. The developed method was successfully applied to determine BPA and TBPA in 136 tea samples.

Potential changes in the symbiotic relationship between rice (Oryza sativa) and microorganisms have occurred during the domestication of Asian cultivated rice (O. sativa) from common wild rice (O. rufipogon) and in response to global climate change, along with evolving adaptations to the environment. The potential genes may express differently or dominate the symbiotic relationships between AMF and plants, which may be beneficial in rice breeding. To date, research on this important topic has been limited. In this study, we aimed to examine the symbiotic relationship of common wild rice and Asian cultivated rice species with arbuscular mycorrhizal fungi (AMF). By conducting a comparative metagenomic analysis of the rhizospheres of wild and cultivated rice species, we identified differences in Rhizophagus intraradices-related genes associated with wild and cultivated rice, as well as functional genes of AMF. Furthermore, we obtained root-related genes associated with AMF from transcriptome data of rice roots. Our results collectively suggest that R. intraradices-related genes in the rhizosphere of wild rice may be more conducive to its colonization. Additionally, bacteria from the Nitrosomonadaceae and Nitrospiraceae families identified in the rhizosphere of wild rice exhibited positive correlations with R. intraradices-related genes 1480749 and 1871253, which may indicate that nitrobacteria can enhance the functions of R. intraradicesin association with wild rice. Next, in a case study using comparative transcriptome analysis of root samples obtained from R. intraradices-inoculated wild and cultivated rice plants, we found significantly higher expression levels of the strigolactone pathway-related genes DWARF 3 (D3) and D14 in R. intraradices-inoculated common wild rice than in R. intraradices-inoculated cultivated rice. This study provides a theoretical basis for identifying the effects of domestication on mycorrhizal symbiosis-related genes, which could be promoted in wild rice in the future.

Leptin is widely distributed in many tissues, including the nervous system. However, the ontogeny of leptin expression in the dorsal root ganglion (DRG) is unclear. Recent studies have shown that leptin is involved in the regulation of neuropathic pain induced by nerve injury. Our previous results showed that exogenous leptin administration alleviated the pain behaviors induced by chronic constriction sciatic nerve injury. In the present study, the ontogenic expression of leptin was detected in the DRG of the mouse embryo at days 15.5 (E15.5), E17.5, and E19.5 of gestation and in the postnatal mouse at days 5 (P5), P15, and P25, and in the adult mouse. Leptin immunoreactivity and mRNA were not found in DRG at E15.5. The percentage of leptin immunopositive (leptin+) neurons was about 27% at E17.5. It continued to increase to about 70% at P5. From P5 to P15, there was no significant change. The proportion of DRG neurons positive for leptin decreased after P15 and there were about 41% leptin+neurons in adults. The expression profile of leptin mRNA is similar to leptin immunoreactivity. Oxaliplatin (OXA) is an effective platinum-based drug used as first-line chemotherapy for advanced colorectal cancer. However, it may induce neuropathic pain. In the current study, we found that the expression of leptin was increased in the lumbar 4–6 DRG of OXA-treated mice. These results indicate that leptin is involved in the regulation of DRG development and OXA-induced neuropathic pain.

The self-assembly property of ursolic acid (UA) without any modification was reported here for the first time. The results showed that ursolic acid could aggregate into organogels in bromobenzene and some alcoholic solvents. It was proved that the driving forces for gel formation were intermolecular hydrogen bonding and packing interaction between the rigid backbones of ursolic acid through Fourier-transform infrared (FT-IR) spectra.The self-assembly property of ursolic acid (UA) without any modification was reported here for the first time. The results showed that ursolic acid could aggregate into organogels in bromobenzene and some alcohols solvents. It was proved that the driving forces for gel formation was intermolecular hydrogen bonding and packing interaction between the rigid backbones of ursolic acid.

The commercialization of lithium–sulfur batteries (LSBs) is obstructed by several technical challenges, the most severe of which is the irreversible loss of soluble polysulfide intermediates. These soluble polysulfides must be anchored or confined in the cathode side to maintain the long life of the LSBs. Here, 1T MoS2–MnO2/CC heterostructure functional covering layer is designed to regulate the rate-determining step from the liquid-to-solid reaction to solid-to-solid reaction. Rapid and uniform nucleation of solid Li2S2/Li2S is therefore achieved, and the loss of soluble polysulfides is retarded. The Li–S batteries assembled with 1T MoS2–MnO2/CC covering layer therefore deliver outstanding rate capabilities even under high sulfur loads and large current rates. This study paves a novel way to suppress the polysulfides’ “farewell effect” from the perspective of the kinetics.

A novel three-component reaction was developed via a one-pot strategy for the construction of diarylmethanol esters by using a halobenzene and an ester in N,N-dimethylformamide (DMF) under mild conditions. The reaction involves the direct functionalization of halobenzene under the Sm–CuI catalyst system. It was proved that 10% (mol) of CuI is sufficient to realize the reductive coupling reaction. Influences of substituents were illustrated from both electronic and steric effects. The reaction mechanism was also discussed.