Revealing unexpected complex encoding but simple decoding mechanisms in motor cortex via separating behaviorally relevant neural signals.

In motor cortex, behaviorally relevant neural responses are entangled with irrelevant signals, which complicates the study of encoding and decoding mechanisms. It remains unclear whether behaviorally irrelevant signals could conceal some critical truth. One solution is to accurately separate behaviorally relevant and irrelevant signals at both single-neuron and single-trial levels, but this approach remains elusive due to the unknown ground truth of behaviorally relevant signals. Therefore, we propose a framework to define, extract, and validate behaviorally relevant signals. Analyzing separated signals in three monkeys performing different reaching tasks, we found neural responses previously considered to contain little information actually encode rich behavioral information in complex nonlinear ways. These responses are critical for neuronal redundancy and reveal movement behaviors occupy a higher-dimensional neural space than previously expected. Surprisingly, when incorporating often-ignored neural dimensions, behaviorally relevant signals can be decoded linearly with comparable performance to nonlinear decoding, suggesting linear readout may be performed in motor cortex. Our findings prompt that separating behaviorally relevant signals may help uncover more hidden cortical mechanisms.

Characterization of the CsCENH3 protein and centromeric DNA profiles reveal the structures of centromeres in cucumber.

Centromeres in eukaryotes mediate the accurate segregation of chromosomes during cell division. They serve as essential functional units of chromosomes and play a core role in the process of genome evolution. Centromeres are composed of satellite repeats and highly repetitive centromeric retrotransposons (CRs), which vary greatly even among closely related species. Cucumber (Cucumis sativus) is a globally cultivated and economically important vegetable and the only species in the Cucumis genus with seven pairs of chromosomes. Therefore, studying the centromeres of the Cucumis subgenus may yield valuable insights into its genome structure and evolution. Using chromatin immunoprecipitation (ChIP) techniques, we isolated centromeric DNA from cucumber reference line 9930. Our investigation into cucumber centromeres uncovered the centromeric satellite sequence, designated as CentCs, and the prevalence of Ty1/Copia long terminal repeat retrotransposons. In addition, active genes were identified in the CsCENH3 nucleosome regions with low transcription levels. To the best of our knowledge, this is the first time that characterization of centromeres has been achieved in cucumber. Meanwhile, our results on the distribution of CentCs and CsCRs in the subgenus Cucumis indicate that the content of centromeric repeats in the wild variants was significantly reduced compared with the cultivated cucumber. The results provide evidence for centromeric DNA amplification that occurred during the domestication process from wild to cultivated cucumber. Furthermore, these findings may offer new information for enhancing our understanding of phylogenetic relationships in the Cucumis genus.

An Ultrasound-Fenton Process for the Degradation of 2,4,6-Trinitrotoluene.

2,4,6-Trinitrotoluene (TNT), one of the main compounds in ammunition wastewater, is harmful to the environment. In this study, the treatment efficiency of 2,4,6-TNT by different treatment processes, including ferrous ion (Fe2+), hydrogen peroxide (H2O2), Fenton, ultrasound (US) irradiation, US + Fe2+, US + H2O2 and US-Fenton process, was compared. The results showed that US-Fenton was the most effective among all methods studied. The effects of initial pH, reaction time and H2O2 to Fe2+ molar ratio were investigated. The results showed that the removal of TNT, TOC and COD was maximum at an initial pH of 3.0 and H2O2 to Fe2+ molar ratio of 10:1. TNT, TOC and COD removal was fast in the first 30 min, reaching 83%, 57% and 50%, then increased gradually to 99%, 67% and 87% until 300 min, respectively. Semi-batch mode operation increased the removal of TNT and TOC by approximately 5% and 10% at 60 min, respectively. The average carbon oxidation number (ACON) was increased from -1.7 at 30 min to a steady-state value of 0.4, indicating the mineralization of TNT. Based on GC-MS analysis, 1,3,5-trinitrobenzene, 2,4,6-trinitrobenzene acid, 3,5-dinitrobenznamine and 3,5-dinitro-p-toluidine were the major byproducts from the US-Fenton process. The TNT degradation pathway was proposed, which involved methyl group oxidation, decarboxylation, aromatic ring cleavage and hydrolysis.

Genome-wide characterization, phylogenetic and expression analysis of Histone gene family in cucumber (Cucumis sativus L.).

Histones are essential components of chromatin and play an important role in regulating gene transcription and participating in DNA replication. Here, we performed a comprehensive analysis of this gene family. In this study, we identified 37 CsHistones that were classified into five groups (H1, H2A, H2B, H3 and H4). The closely linked subfamilies exhibited more similarity in terms of motifs and intron/exon numbers. Segmental duplication (SD) is the main driving force of cucumber CsHistones expansion. Analysis of cis-regulatory elements in the promoter region of CsHistones showed that CsHistones can respond to a variety of stresses. RNA-Seq analysis indicated that the expression of most CsHistones was associated with different stresses, including downy mildew, powdery mildew, wilt, heat, cold, salt stress, and waterlogging. Expression analysis showed that several genes of H3 group were highly expressed in different reproductive organs. Notably, CsCENH3 (CsHistone30) has the characteristics of a variant histone, and we demonstrated that CsCENH3 was localized on the nucleus and its proteins were expressed in centromere region. These findings provide valuable information for the identification and potential functions of Histone genes and ideas for the cultivation of CENH3-mediated haploid induction lines in cucumber.

Facilitated catalytic ozonation of atrazine over highly stabilized Zn-Al layered double oxides composites: efficacy and mechanism.

A series of Zn-Al Layered Double Oxides (ZnAl-LDO) composites were prepared by the hydrothermal and calcination method via employing the Zn-Al Layered Double Hydroxide (ZnAl-LDH) as the precursors in the present study. The structural properties and the catalytic ozonation activity of ZnrAl-T composites synthesized with different Zn/Al molar ratios and calcination temperatures were systematically investigated. Diversified characterizations were applied to analyze the phase structure and chemical composition of ZnrAl-T composites. As the calcination temperature increased, the layered ZnAl-LDH structure could be entirely destroyed and the crystallinity gradually improved. With the Zn/Al mole ratio of 4.0 and calcination temperature of 500°C, the Zn4Al-500 composite obtained the outstanding catalytic ozonation performance for atrazine (ATZ) degradation with the pseudo-first-order constant of 0.5080 min-1, which was 5 times more than that in O3 alone. Meanwhile, the ATZ degradation efficiency was gradually enhanced from 44.1% to 99.9% within 3.0 min when the solution pH ranged from 3.0 to 10.0. Besides, the Zn4Al-500 composite exhibited splendid stability over multiple reaction cycles. In addition, the radical scavenging test and electron spin resonance measurement demonstrated that superoxide radical and hydroxyl radical are the dominant reactive species in O3/Zn4Al-500 process. Moreover, nineteen and ten transformation products were detected in O3 alone and O3/Zn4Al-500 process, and possible degradation pathways of ATZ were further elucidated. Overall, the Zn4Al-500 composite would provide a potential alternative for pollutants removal due to its high catalytic ozonation efficiency, stability, and reusability.

Enhanced refractory organics removal by •OH and 1O2 generated in an electro-oxidation system with cathodic Fenton-like reaction.

Recently, carbon nanotubes coated carbon black and polytetrafluoroethylene (CNTs-C/PTFE) gas diffusion electrode was used as an air-cathode in an electro-oxidation (EO) system for effectively generating hydrogen peroxide (H2O2) through a 2-electron oxygen reduction reaction (ORR). This ORR-EO system not only lowered applied voltage and conserved energy, but the synergistic peroxone (O3/H2O2) reaction could increase hydroxyl radicals (•OH) generation for organics elimination. However, a significant proportion of H2O2 was left in the effluent of ORR-EO, which was a loss of resources and energy. In this study, a Fenton-like reaction for in-situ H2O2 decomposition to generate active oxidation species was inserted by introducing MnO2 into the cathodic catalyst layer, and the sole MnO2/CNTs-C/PTFE air-cathode could accomplish 90% of phenol degradation. When MnO2/CNTs-C/PTFE air-cathode combined with Ti/NATO anode in an ORR-EO system, all anodic oxidation, Fenton-like reaction, and peroxone took place to successfully generate •OH and singlet oxygen (1O2). Over 95% of TOC in phenol and landfill leachate bio-effluent was effectively eliminated, with 20% energy savings compared to the ORR-EO with CNTs-C/PTFE air cathode.

Simultaneous Determination and Health Risk Assessment of Four High Detection Rate Pesticide Residues in Pu'er Tea from Yunnan, China.

Four pesticides with a high detection rate in Pu'er tea have been determined by a QuEChERS (quick, easy, cheap, effective, rugged, safe) method with multiwalled carbon nanotubes (MWCNTs), and combined ultrahigh-performance liquid chromatography-triple quadrupole linear ion trap-tandem mass spectrometry (UHPLC-QTRAP-MS/MS). MWCNs have been compared with other common purification materials, and found to be superior. The matrix effect was systematically studied, and the results show that the MWCNs can quickly and effectively reduce matrix interference values, which were in the range from -17.8 to 13.8. The coefficients (R2) were greater than 0.99, with the limit of quantification ranging from 0.1 to 0.5 µg/kg, and the recovery rate ranging from 74.8% to 105.0%, while the relative standard deviation (RSD) ranged from 3.9% to 6.6%. A total of 300 samples, taken from three areas in which Yunnan Pu'er tea was most commonly produced, tested for four pesticides. The results show that the detection rate of tolfenpyrad in Pu'er tea was 35.7%, which is higher than other pesticides, and the lowest was indoxacarb, with 5.2%. The residual concentrations of chlorpyrifos, triazophos, tolfenpyrad and indoxacarb ranged from 1.10 to 5.28, 0.014 to 0.103, 1.02 to 51.8, and 1.07 to 4.89 mg/kg, respectively. By comparing with China's pesticide residue limits in tea (GB 2763-2021), the over standard rates of chlorpyrifos, tolfenpyrad, and indoxacarb were 4.35%, 0.87% and 0%, respectively. The risk assessment result obtained with the hazard quotient (HQ) method shows that the HQ of the four pesticides was far less than one, indicating that the risk is considered acceptable for the four pesticides in Pu'er tea. The largest HQ was found for tolfenpyrad, 0.0135, and the smallest was found for indoxacarb, 0.000757, but more attention should be paid to tolfenpyrad in daily diets in the future, because its detection rate, and residual and residual median were all relatively high.

Determination of new generation amide insecticide residues in complex matrix agricultural food by ultrahigh performance liquid chromatography tandem mass spectrometry.

Eight new generation amide insecticide residues analysis by multiwalled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS and ultrahigh performance liquid chromatography tandem mass spectrometry has been developed and successfully applied in complex matrix such as orange, celery, onion, litchi, mango, shallot, chives, avocado, garlic. The matric effect of MWCNs is optimized and compared with ordinary cleanup materials. The results show that the performance of MWCNs is fine and effectively reduce matrix interference. Through chemical structure skeletons analyzed, chlorantraniliprole, bromoantraniliprole, and cyantraniliprole can cause same product ions of m/z 286.0 or 177.1 in the ESI+ mode, then tetrachlorantraniliprole and cyclaniliprole can produce collective ions of m/z 146.9 in the ESI- mode. The coefficients (R2) were greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 µg/kg, the recovery rate ranges from 71.2 to 120%, and the relative standard deviation (RSD) ranges from 3.8 to 9.4%. The method is fast, simple, sensitive, and suitable for the rapid determination of amide pesticides in complex matrix agricultural food.

Robust neural decoding by kernel regression with Siamese representation learning.

Objective. Brain-machine interfaces (BMIs) provide a direct pathway between the brain and external devices such as computer cursors and prosthetics, which have great potential in motor function restoration. One critical limitation of current BMI systems is the unstable performance, partly due to the variability of neural signals. Studies showed that neural activities exhibit trial-to-trial variability, and the preferred direction of neurons frequently changes under different conditions. Therefore, a fixed decoding function does not work well.Approach. To deal with the problems, we propose a novel kernel regression framework. The nonparametric kernel regression is used to fit diverse decoding functions by finding similar neural patterns to handle neural variations caused by varying tuning functions. Further, the representations of raw neural signals are learned by Siamese networks and constrained by kinematic parameters, which can alleviate neural variations caused by intrinsic noises and task-irrelevant information. The representations are jointly learned with the kernel regression framework in an end-to-end manner so that neural variations can be tackled effectively.Main results. Experiments on two datasets demonstrate that our approach outperforms most existing methods and significantly improves the robustness in challenging situations such as limited samples and missing channels.Significance. The proposed approach demonstrates robust performance with different conditions and provides a new and inspiring perspective toward robust BMI control.

Degradation of triclosan by anodic oxidation/in-situ peroxone process: Kinetics, pathway and reaction mechanism.

Triclosan (TCS) is an emerging contaminant that threatens the environment and human health. This study was conducted to investigate TCS abatement by a novel electro-oxidation (EO) process, which used a Ti-based nickel and antimony doped tin oxide (NATO/Ti) anode and a carbon nanotubes (CNTs) doped carbon/PTFE (CNTs-C/PTFE) gas diffusion electrode (GDE) for oxygen reduction reaction (ORR). A comparative study was also performed for TCS degradation by using a traditional EO with a nickel foam cathode, termed as HER-EO. The optimal initial TCS concentration, current density and solution pH for TCS degradation during the ORR-EO and HER-EO were investigated. Results showed that ORR-EO removed more than 98% of TCS in 10-60 min under the concentration of 5-50 mg/L. The TCS degradation followed pseudo-first-order kinetics and its main intermediates were observed during the ORR-EO and HER-EO using liquid chromatography combined mass (LC-MS). The results of FED analysis and toxicity prediction by ECOSAR software showed that less intermediates accumulated during the ORR-EO and the residues were less harmful. The ORR-EO degradation mechanism for TCS was attacking on the ether bond and the benzene ring by •OH. This novel ORR-EO process exhibits a great merit in the field of emerging contaminants abatement.

Comparison of the chemical constituents of raw Fructus Aurantii and Fructus Aurantii stir-baked with bran, and the biological effects of auraptene.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Aurantii (FA) is a Chinese herbal medicine commonly used in clinical practice to improve gastrointestinal motility, treat dyspepsia, and relieve constipation. More than 20 processing methods of FA have been recorded, among which FA stir-baked with bran is the earliest, most time consuming, and the most popular one. Raw FA has a strong ability to promote qi-moving and has middle-energizer-soothing effects; therefore, it is often used to relieve hypochondrium distension and pain, and to relax the stagnation of the liver Qi. FA stir-baked with bran is more effective in nourishing the stomach and curing indigestion. AIM OF THE STUDY: In this study, the chemical composition and differences between raw FA and FA stir-baked with bran were systematically compared. The chemical components that increased after stir-baking FA and bran were separated and their pharmacodynamic characteristics were determined. Lastly, the processing mechanism of FA was further explained. MATERIALS AND METHODS: Twelve main chemicals in raw FA and FA stir-baked with bran were compared using high-performance liquid chromatography (HPLC). The main differential components were identified, separated, purified, and then analyzed using pharmacodynamic tests. The intestine-pushing test, in vitro smooth muscle test, and in vitro acetylcholinesterase (AchE) activity test in mice were performed to explain the mechanism of auraptene in improving gastrointestinal motility. RESULTS: Using HPLC, the primary chemical that differed between raw FA and FA stir-baked with bran was identified as auraptene. The processed FA was extracted, separated, and purified to obtain pure auraptene. The intestine-pushing test in mice showed that low (0.6 mg·kg-1) and medium doses (1.2 mg·kg-1) of auraptene could promote peristalsis of the small intestine, whereas a high dose (2.4 mg·kg-1) inhibited peristalsis. In vitro studies on the smooth muscle of mice showed that a low dose of auraptene (0.2 mmol·L-1, 10-800 µL) could promote contraction, whereas a high dose (0.2 mmol·L-1, >1000 µL) had the opposite effect. Auraptene has a mechanism of action similar to that of the acetylcholinesterase inhibitor, neostigmine. Additionally, auraptene could inhibit AchE activity in vitro. CONCLUSIONS: Auraptene is the main chemical constituent that differs between raw FA and FA stir-baked with bran. Pharmacodynamic tests showed that auraptene has a cholinergic effect, by virtue of its role as an acetylcholinesterase inhibitor. Moreover, auraptene could dually regulate the gastrointestinal smooth muscle. Auraptene was present in low levels and its content varied in FA stir-baked with bran, depending on the origin and source of FA, and the treatment procedures it was subjected to. In the Chinese Pharmacopoeia, the recommended dose of FA stir-baked with bran is a low dose of 3-10 g, which effectively promotes small-intestinal peristalsis. The mechanism of action is attributed to an increase in the relative content of acetylcholine by the inhibition of AchE activity to promote gastrointestinal motility. The increased levels of auraptene in FA stir-baked with bran are the main reason and the primary purpose for the change in its medicinal properties. This technique, therefore, has potential to be used as one of the main processing mechanisms of raw FA.

Efficient removal of refractory organics in landfill leachate concentrates by electrocoagulation in tandem with simultaneous electro-oxidation and in-situ peroxone.

Leachate concentrates, an effluent produced from nanofiltration and/or reverse osmosis, contains a high amount of salts and dissolved organics especially refractory organics. Thus, the treatment of leachate concentrates would consume high energy or a large amount of chemicals. The present study is to develop an effective treatment method by using coupled electrochemical methods with the least possible energy consumption. The leachate concentrates was pretreated by electrocoagulation (EC), with aluminum or iron electrodes as anodes, to decrease the dissolved organic content. EC with Al electrode was found to be more efficient by consuming 1.25 kWh/m3 energy to remove 70% of total organic carbon (TOC). EC effluent was further subjected to a novel simultaneous electro-oxidation and in-situ peroxone process, which used a Ti-based nickel and antimony doped tin dioxide (NATO) as anode and a carbon nanotube coated carbon-polytetrafluoroethylene (CNT-C/PTFE) as cathode for oxygen reduction reaction (ORR). Compared with a traditional EO with cathode for hydrogen evolution reaction (HER-EO), ORR-EO obtained higher efficiency and an energy consumption of 26.25 kWh/m3, which was much lower than 35.5 kWh/m3 for HER-EO. Results showed that after ORR-EO, a final TOC of 57.3 mg/L was obtained. Thus, EC in tandem with ORR-EO process has an excellent capability and economic merit in the field of treating leachate concentrates.

[Simultaneous determination of antibiotics and triphenylmethanes veterinary drug residues in fish and shrimp by dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry].

A method was established to rapidly determine 20 kinds of veterinary drug residues including three catagories of antibiotics (sulfonamides, quinolones, and chloramphenicols) and two kinds of triphenylmethanes (malachite green (MG) and leucomalachite green (LMG)) in fish and shrimp, based on dispersive solid phase extraction purification-ultra high performance liquid chromatography-tandem mass spectrometry. The samples were first hydrolyzed using a dipotassium hydrogen phosphate solution, and then extracted using acetonitrile. Afterward, the extraction solution was dehydrated and salted out with sodium chloride and condensed to nearly dry using a rotating evaporator. This residue was dissolved in 1.0 mL methanol. The resulting solution was purified by dispersive solid phase extraction method with C18 and PSA sorbents, and filtered through a filter. The target compounds were separated employing a ZORBAX C18 column. The mass spectrometer datas were acquired by multiple reaction monitoring (MRM) of positive and negative modes and quantitated applying the isotope internal standard method. The 20 veterinary drugs showed a good linear relationship in the range of 0.2-300 µg/L. The limits of detection and the limits of quantification were 0.1-0.6 and 0.3-1.8 µg/kg, respectively, while the correlation coefficients were greater than 0.99. The average recoveries at the three spiked levels (1, 5, and 20 times of quantitative limits) ranged between 72.5%-118%, with the relative standard deviations of 1.9%-9.8%. The advantages of method include a simple pretreatment, a high detection efficiency, and a low cost. Moreover, it is suitable for the simultaneous determination of multiple veterinary drug residues in fish and shrimp.

Enhanced catalytic ozonation towards oxalic acid degradation over novel copper doped manganese oxide octahedral molecular sieves nanorods.

A series of copper doped manganese oxide octahedral molecular sieves (Cu-OMSx-T) with different Cu/Mn ratios and hydrothermal temperatures were successfully synthesized and used for catalytic ozonation towards oxalic acid (OA) degradation. The as-prepared Cu-OMSx-T composites were comprehensively investigated by BET, FT-IR, XPS and etc. characterizations. The results indicated that the Cu doping would increase the specific surface area, change chemical bonds, and promote the transformation of multivalent metals and the generation of oxygen vacancies. It was noteworthy that the hydrothermal temperature played an important role in the morphology of Cu-OMSx-T composites and the Cu/Mn molar ratios greatly influenced the catalytic activities. Amongst, the Cu-OMS0.5-140 achieved the optimum catalytic activity with 97.3% of OA degradation efficiency and 98.8% of mineralization rate in 30 min at pH 6.0. Moreover, hydroxyl radical and superoxide radical were identified as the major reactive radicals and the catalytic mechanism for OA degradation enhancement was also elucidated. In addition, the Cu-OMS0.5-140 exhibited great stability and reusability with high OA mineralization rate (>90%) and low metal release after five times recycle. Overall, the results indicated that the synthesized Cu-OMS0.5-140 is an efficient, stable, and recyclable ozonation catalyst, and could be a promising alternative material for water purification.

Sampling for DUS Test of Flower Colors of Ranunculus asiaticus L. in View of Spatial and Temporal Changes of Flower Colorations, Anthocyanin Contents, and Gene Expression Levels.

Sampling for DUS test of flower colors should be fixed at the stages and sites that petals are fully colored, and besides, flower colorations are uniform among individuals and stable for a period of time to allow testers to get consistent results. It remains a problem since spatial and temporal flower colorations are reported a lot but their change traits are little discussed. In this study, expression state, uniformity and stability of color phenotypes, anthocyanin contents, and gene expression levels were taken into account based on measurements at 12 development stages and three layers (inner, middle, and outer petals) of two varieties of Ranunculus asiaticus L. to get their best sampling. Our results showed that, outer petals of L9⁻L10 (stage 9⁻stage 10 of variety 'Jiaoyan zhuanhong') and C5⁻C6 (stage 5⁻stage 6 of variety 'Jiaoyan yanghong') were the best sampling, respectively. For DUS test, it is suggested to track flower colorations continuously to get the best sampling as well as representative colors since different cultivars had different change traits, and moreover, full expression of color phenotypes came later and lasted for a shorter duration than those of anthocyanin contents and gene expressions. Our innovation exists in following two points. Firstly, a model of change dynamic was introduced to illustrate the change traits of flower colorations, anthocyanin contents, and gene expressions. Secondly, genes used for expression analysis were screened on account of tentative anthocyanins, which were identified based on comparison between liquid chromatography⁻mass spectrometry (LC⁻MS) results and molecular mass and mass fragment pattern (M²) of each putative anthocyanin and their fragments deduced in our previous study. Gene screening in this regard may also be interest for other non-model plant genera with little molecular background.

Diversity in flower colorations of Ranunculus asiaticus L. revealed by anthocyanin biosynthesis pathway in view of gene composition, gene expression patterns, and color phenotype.

Anthocyanin biosynthesis is one of the best studied secondary metabolisms. However, related pathways were generally concluded based on anthocyanin components; most studies focused on the backbone forming of anthocyanidins (cyanidin, delphinidin, and pelargonidin) of model or commercial plants, while anthocyanin modification was less discussed, and non-model plants with abundant colorations were less researched either. Ranunculus asiaticus L. has great diversity in flower colorations, not only indicating its value in researching anthocyanin biosynthesis but also implying it is unique in this regard. Based on transcriptome sequencing and gene annotation of three varieties (10 samples) of Ranunculus asiaticus L., 176 unigenes from 151,136 unigenes were identified as involved in anthocyanin biosynthesis, among which, 74 unigenes were related to anthocyanin modification; 61 unigenes were responsible for glycosylation at C3 and C5 with 3-monosaccharides of glucose, 3-biosides of rutinose, sophorose, or sambubiose to form 3Gly-, 3Gly5Gly-, 3Gly3'Gly-, 3Gly2''Gly-, 3Gly2''Xly-, 3Gly2''Rly-glycosylated anthocyanins, etc.; 2 unigenes transferred -CH3; 11 unigenes of BAHD family catalyzd the aromatic or malonyl acylation at 6'' / 6''''position of 3/5-O-glucoside. Based on gene composition, a putative pathway was established. The pathway was validated by flower colorations, and gene expression patterns where F3H, F3'H, 3GT, 5GT, and FMT2 were highly expressed in varieties colored as lateritious and carmine, while variety with purple flowers had high expression of F3'5'H and 3MAT. In view of anthocyanin biosynthesis pathway of Ranunculus asiaticus L., great diversity in its flower colorations was illustrated via the complete branches (F3H, F3'H and F3'5'H) as well as complete modifications (glycosylation, methylation, and acylation), and besides, via the higher percentage of C3 glycosylation than C5 glycosylation.

[Removal of Antibiotics During In-situ Sludge Ozone-reduction Process].

Two sequencing batch reactors were established at bench-scale, with one used as an in-situ sludge ozone-reduction system and the other as a control system. Both systems were continuously operated for 90 days to comparatively investigate the elimination of nine typical antibiotics (i.e., tetracycline, oxytetracycline, doxytetracycline, norfloxacin, ofloxacin, ciprofloxacin, lomefloxacin, enrofloxacin, and azithromycin) during the in-situ sludge ozone-reduction process. Results indicated that the presence of target antibiotics in the influent (100 µg·L-1 each) had an insignificant influence on the removal of COD, total nitrogen, ammonia, and total phosphorus by the activated sludge. The antibiotic concentrations in the effluent of the reduction system remained fairly stable over the entire operation period, and were similar to those in the effluent of the control system; however, the antibiotic concentrations in the sludge of the reduction system were obviously lower than those in the control system sludge. Mass balance calculations revealed that the input and output of target antibiotics gradually approached balance in both the systems. Ozone degradation and excess sludge discharge were the main pathways for target antibiotic removal in the reduction and the control systems, respectively. The influent antibiotics could be degraded by 83% in the sludge ozonation module of the reduction system, while 82% of the influent antibiotics were discharged with excess sludge in the control system. Therefore, the in-situ sludge ozone-reduction process could greatly reduce the release of antibiotics from the activated sludge system, which is of great importance in practice.

Behavior of tetracycline and macrolide antibiotics in activated sludge process and their subsequent removal during sludge reduction by ozone.

Ozonation is a promising means for the reduction of excess sludge in wastewater treatment plants. However, little information is available on the removal of antibiotics during sludge ozonation. Therefore, this study investigated first the behavior of four commonly-used hydrophobic antibiotics, including three tetracyclines (tetracycline, oxytetracycline, and doxycycline) and one macrolide (azithromycin) in activated sludge process and then their removal during sludge reduction by ozone. Results indicate that the studied antibiotics were primarily transferred into the solid phase of activated sludge via sorption, which was a reversible, spontaneous, and exothermic process governed by surface reactions. Sludge ozonation could effectively remove 86.4-93.6% of the antibiotics present in the sludge at an ozone dose of 102 mg per gram of mixed liquor suspended solids and pH 7.2. The removal of studied antibiotics mainly proceeded through desorption and subsequent oxidation. Increasing the initial pH from 5.0 to 9.5 obviously enhanced the antibiotic removal during sludge ozonation. This study demonstrated that the activated sludge process coupled with sludge ozonation can simultaneously reduce excess sludge and eliminate antibiotics.

An insight into the removal of fluoroquinolones in activated sludge process: Sorption and biodegradation characteristics.

The detailed sorption steps and biodegradation characteristics of fluoroquinolones (FQs) including ciprofloxacin, enrofloxacin, lomefloxacin, norfloxacin, and ofloxacin were investigated through batch experiments. The results indicate that FQs at a total concentration of 500µg/L caused little inhibition of sludge bioactivity. Sorption was the primary removal pathway of FQs in the activated sludge process, followed by biodegradation, while hydrolysis and volatilization were negligible. FQ sorption on activated sludge was a reversible process governed by surface reaction. Henry and Freundlich models could describe the FQ sorption isotherms well in the concentration range of 100-300µg/L. Thermodynamic parameters revealed that FQ sorption on activated sludge is spontaneous, exothermic, and enthalpy-driven. Hydrophobicity-independent mechanisms determined the FQ sorption affinity with activated sludge. The zwitterion of FQs had the strongest sorption affinity, followed by cation and anion, and aerobic condition facilitated FQ sorption. FQs were slowly biodegradable, with long half-lives (>100hr). FQ biodegradation was enhanced with increasing temperature and under aerobic condition, and thus was possibly achieved through co-metabolism during nitrification. This study provides an insight into the removal kinetics and mechanism of FQs in the activated sludge process, but also helps assess the environmental risks of FQs resulting from sludge disposal.

[Determination of 41 pesticide residues in vegetables by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry].

A multiresidue analytical method for the rapid determination of 41 pesticide residues in vegetables was developed by using QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), including recessive pesticides, banned pesticides and pesticides with restrict use, plant growth regulators and some other pesticides with high detection rates. The vegetable sample was extracted by 1% (v/v) acetic acid-acetonitrile, cleaned-up by primary secondary amine (PSA) and injected for analysis. The positive and negative ion modes and multiple reaction monitoring (MRM) mode were used in the analysis, and the analytes were quantified by the external standard method. Under the conditions of optimized QuEChERS, chromatography and mass spectrometry, the 41 pesticides showed good linearities in the range of 1.0 µg/L to 100 µg/L, with the correlation coefficients (r2) higher than 0.999. The limits of detection of the method were 0.003 µg/kg to 1.00 µg/kg. The average recoveries of the 41 pesticides in different matrices were in the range of 74.1%-120.4% with the relative standard deviations from 2.8% to 11.9%. The method has the advantages of rapidity, simplici- ty, high sensitivity and better purification effect. It is suitable for the rapid determination of the common pesticides in vegetables, and it provides a strong guarantee for the risk assessment of the quality and safety of vegetables.