Forgotten memory storage and retrieval in Drosophila.

Inaccessibility of stored memory in ensemble cells through the forgetting process causes animals to be unable to respond to natural recalling cues. While accumulating evidence has demonstrated that reactivating memory-stored cells can switch cells from an inaccessible state to an accessible form and lead to recall of previously learned information, the underlying cellular and molecular mechanisms remain elusive. The current study used Drosophila as a model to demonstrate that the memory of one-trial aversive olfactory conditioning, although inaccessible within a few hours after learning, is stored in KCαß and retrievable after mild retraining. One-trial aversive conditioning triggers protein synthesis to form a long-lasting cellular memory trace, approximately 20 days, via creb in KCαß, and a transient cellular memory trace, approximately one day, via orb in MBON-α3. PPL1-α3 negatively regulates forgotten one-trial conditioning memory retrieval. The current study demonstrated that KCαß, PPL1-α3, and MBON-α3 collaboratively regulate the formation of forgotten one-cycle aversive conditioning memory formation and retrieval.

Aversive conditioning information transmission in Drosophila.

Animals rapidly acquire surrounding information to perform the appropriate behavior. Although social learning is more efficient and accessible than self-learning for animals, the detailed regulatory mechanism of social learning remains unknown, mainly because of the complicated information transfer between animals, especially for aversive conditioning information transmission. The current study revealed that, during social learning, the neural circuit in observer flies used to process acquired aversive conditioning information from demonstrator flies differs from the circuit used for self-learned classic aversive conditioning. This aversive information transfer is species dependent. Solitary flies cannot learn this information through social learning, suggesting that this ability is not an innate behavior. Neurons used to process and execute avoidance behavior to escape from electrically shocked flies are all in the same brain region, indicating that the fly brain has a common center for integrating external stimuli with internal states to generate flight behavior.

Novel discovery of schisandrin A regulating the interplay of autophagy and apoptosis in oligoasthenospermia by targeting SCF/c-kit and TRPV1 via biosensors.

Oligoasthenospermia is the primary cause of infertility. However, there are still enormous challenges in the screening of critical candidates and targets of oligoasthenospermia owing to its complex mechanism. In this study, stem cell factor (SCF), c-kit, and transient receptor potential vanilloid 1 (TRPV1) biosensors were successfully established and applied to studying apoptosis and autophagy mechanisms. Interestingly, the detection limit reached 2.787 × 10-15 g/L, and the quantitative limit reached 1.0 × 10-13 g/L. Furthermore, biosensors were used to investigate the interplay between autophagy and apoptosis. Schisandrin A is an excellent candidate to form a system with c-kit similar to SCF/c-kit with a detection constant (KD) of 5.701 × 10-11 mol/L, whereas it had no affinity for SCF. In addition, it also inhibited autophagy in oligoasthenospermia through antagonizing TRPV1 with a KD of up to 4.181 × 10-10 mol/L. In addition, in vivo and in vitro experiments were highly consistent with the biosensor. In summary, high-potency schisandrin A and two potential targets were identified, through which schisandrin A could reverse the apoptosis caused by excessive autophagy during oligoasthenospermia. Our study provides promising insights into the discovery of effective compounds and potential targets via a well-established in vitro-in vivo strategy.

Occurrence and ecological risks of flonicamid and its metabolites in multiple substrates from intensive rice-vegetable rotations in tropical China.

Rice-vegetable rotations are dominant in (sub)-tropical agriculture worldwide. However, fate and risks of the insecticide flonicamid (FLO) and its main degradates (collectively called FLOMs) in multiple substrates from those cropping systems remain largely unknown. In this study, we characterized residual concentrations, driving factors, transport, and potential ecological risks of FLOMs in different substrates in 28 tropical rice-vegetable rotations. Concentrations (median) of FLOMs were 0.013-3.03 (0.42) ng g-1 in plants, 0.012-1.92 (0.23) ng g-1 in soil, 0.029-0.63 (0.126) µg L-1 in water, and 0.002-0.398 (0.055) ng g-1 in sediments. Flonicamid and its metabolite N-(4-trifluoromethylnicotinoyl) glycine were the dominant species in the four substrates (84.1 % to 88.5 %). Plants had the highest levels of FLOMs, with the highest bioconcentration factor in peppers. According to boosted regression trees coupled with a partial least squares structural equation model, levels and composition of FLOMs showed high spatiotemporal and crop-related patterns in different substrates, with patterns highly codetermined by agricultural practices (e.g., crop type and FLO/neonicotinoid/pyrethroid applications), substrate parameters (e.g., pH, organic matter or total organic carbon), and climate features (e.g., wet/dry seasons). Moreover, a fugacity method indicated differences in transport and partitioning patterns in different substrates during rice and vegetable planting periods. Integrated substrate risk assessment of FLOMs contamination was conducted based on species-sensitive distributions and substrate weight index. Although overall risks of FLOM contamination in tropical rice-vegetable rotations were negligible to low, the highest risks were in soils, vegetable planting periods, and a central intensively planted area.

Neonicotinoids in draining micro-watersheds dominated by rice-vegetable rotations in tropical China: Multimedia occurrence, influencing factors, transport, and associated ecological risks.

Multimedia contamination by neonicotinoid (NEO) residues has attracted global attention. However, data regarding the multimedia polluted status under certain typical cropping scenarios and the associated risks are scarce. Here, the multimedia occurrence, spatiotemporal distribution, driving factors, transport, and ecological risks of NEOs from tropical rice-vegetable rotation fields were characterized. The heavy NEOs resided in multiple media, and imidacloprid and acetamiprid were the prevailing NEOs, with concentration contributions of 65-80%. The pollution levels of the NEOs, rather than their compositions, exhibited significant spatiotemporal heterogeneity and were highly correlated with the collective (agricultural practices and climate conditions) and differential (e.g., media properties) factors identified using an auto linear regression model. Furthermore, the multimedia transport of NEOs was largely similar but non-negligibly different during the rainy and dry seasons. A new multimedia ecological risk assessment revealed that 50.6% sites were at high risk, and the risk hotspots occurred in the central areas and the winter planting period. The risks were largely contributed by imidacloprid and thiamethoxam, indicating that there were non-ignorable ecological risks. Our results highlight the differential pollution patterns (distribution, transport, and driving factors) of the prevailing NEOs under tropical agricultural scenarios, and the fact that special attention should be paid to the risks posed by NEOs.

Occurrence, distribution, and driving factors of current-use pesticides in commonly cultivated crops and their potential risks to non-target organisms: A case study in Hainan, China.

Multiple pesticides are heavily applied in crops grown in China's tropics due to the prevalence of diseases and pests, thus posing potential risks to nontarget organisms (e.g., honeybees, lacewings, ladybugs, and humans). However, there is little information on this topic. This study is the first assessment of the occurrence, driving factors, and ecological/human health risks of 32 current-use pesticides (CUPs) in 10 frequently-planted crops collected from practicing rice-vegetable rotation systems in Hainan, China. Of the 132 whole crop samples, 44 (33.3 %) residues from ≥8 pesticides were detected in 9.09 % of crop samples with concentrations ≥0.5 mg kg-1. Six pesticide residues, namely carbendazim, pyraclostrobin, acetamiprid, thiophanate methyl, phoxim, and imidacloprid, were detected in 72.7 % of samples, with concentrations ranging from 0.0021 to 13.5 (median = 0.032) mg kg-1. Among them, carbendazim, pyraclostrobin, and acetamiprid were the most common, contributions from 10.2 to 25.5 % and a detection frequency ranging from 25.6 to 56.1 %. The order of total concentration of 32 CUPs (∑32 CUP) concentrations during the year was January > May > November > August and vegetables > rice, being highly related with pesticides usage pattern, crop type, plant accumulation/dissipation and plant lipid contents. The ecological risk quotients (RQs) to four beneficial terrestrial organisms showed that 9.6-39.1 % of samples posed a potential medium or high ecological risk, with 13.6-65.9 % of samples at ∑RQ > 1 being highly affected by the residues of neonicotinoids and emamectin benzoate. Emamectin benzoate (8.9 %) and acetamiprid (5.6 %) exceeded the individual Maximum Residue Levels based on Chinese legislation (GB2763-2021). Moreover, cumulative dietary exposure presented a higher risk to humans in 11.0 and 22.0 % of the cases for acute and chronic, mainly originating from the higher concentration contributors of systemic pesticides in edible crops. Therefore, the regulation and monitoring of CUP residues is imperative for rice-vegetable rotation systems in tropical China to avoid negative effects on nontarget organisms.

Molecular linkages between chemodiversity and MCPA complexation behavior of dissolved organic matter in paddy soil: Effects of land conversion.

Complexation of dissolved organic matter (DOM) plays a crucial role in regulating the fate and risk of agrochemicals. Here, taking a toxic herbicide MCPA (4-chloro-2- methylphenoxyacetic acid) as the target, the effect of land conversion on complexation behavior of DOM to agrochemicals was investigated in paddy soil. Furthermore, the mechanisms were explored in a new perspective of DOM chemodiversity. Soil DOMs were selected from four long-term cropping systems, including paddy field (PF), vegetable field (VF), rice-vegetable rotation (RV) and abandoned land (AL). The results showed that the DOMs in PF and AL were rich in hydrophilic substances (e.g., carbohydrates or protein-like molecules) with low aromaticity. However, after converting PF to VF and RV, abundant aromatic macromolecules and aliphatic alkanes were observed in DOM. Due to those changes in DOM chemodiversity, the binding site and capability of DOM were highest in VF and RV, and were positively correlated with DOM aromaticity, MW, humus and polar groups (e.g., amino). This was because the complexation of "DOM-MCPA" was static binding via ligand exchange and H-bonding among polar groups and hydrophobic interaction among aromatic skeletons. The EEM-PARAFAC confirmed that microbial humic-like substances dominated the complexation of DOM rather than terrestrial humic-like and tryptophan-like matters. The 2D-COS analysis further revealed that the complexation of DOM preferentially occurred in amino, polysaccharide C-O and aliphatic C-H for PF and AL, but in aromatic C=C, amide C=N for RV and VF. In summary, these findings provide molecular insight into the effect of land conversion on DOM complexation activity, which highlight the importance of DOM chemodiversity. These results will contribute to the risk assessments of agrochemicals in paddy soil.

Polycyclic aromatic hydrocarbons (PAHs) in surface soils of tropical reef islands in China under external plant and soil introduction: Occurrence, sources, risks, and relationships with soil properties, vegetation cover, and soil source.

This study explored the levels, sources, and risks of PAHs in soils from Yongle Atoll (YLA) and Xuande Atoll (XDA) of the Xisha Islands (XSIs) in the South China Sea, China, under different vegetation cover types and soil sources. The results clearly showed that the levels of 16 US EPA priority PAHs (Σ16PAHs) are relatively low in XDA and YLA, with concentrations ranging from not detected (ND) to 151 ng/g (average 15.7 ng/g) and ND to 5.8 ng/g (average 2.1 ng/g), respectively. Three- and four-ring PAHs (62.3% and 53.8%) were widely distributed in YLA and XDA. The average concentration of Σ16PAHs in soils with shrub cover was 1.4, 1.8, 4.8, and 5.0 times higher than that in soils with herbaceous cover, vegetable cover, arbor cover, and no plant cover, respectively. Source analysis using binary diagnostic ratios and the positive matrix factorization (PMF) model suggested that PAHs have similar sources (gasoline/coal combustion, coke production, and biomass combustion), but different contributions in native soil and introduced soil. Moreover, diesel-related vehicular emission was identified to be an additional source of PAHs in native soil. Pearson's correlations revealed strong relationships between PAHs and organic matter or total organic carbon. The cancer risk of PAHs varied among different vegetation cover types and soil sources, following the orders herbaceous cover > vegetable cover > shrub cover > arbor cover > no plant cover and introduced soil > mixed soil > native soil. Nevertheless, the risk remained lower than the risk threshold (10-6), suggesting low carcinogenesis risk in the two atolls. Our findings provide new evidence for the introduction of external vegetation/soil acting as a driver of changes in the characteristics of PAHs in islands, and also underline the negligibility of the PAH increase in soils in the South China Sea, China, from the perspective of health hazards.

Anthrahydroquinone-2-6-disulfonate is a novel, powerful antidote for paraquat poisoning.

Paraquat (PQ) is a widely used fast-acting pyridine herbicide. Accidental ingestion or self-administration via various routes can cause severe organ damage. Currently, no effective antidote is available commercially, and the mortality rate of poisoned patients is exceptionally high. Here, the efficacy of anthrahydroquinone-2-6-disulfonate (AH2QDS) was observed in treating PQ poisoning by constructing in vivo and ex vivo models. We then explored the detoxification mechanism of AH2QDS. We demonstrated that, in a rat model, the PQ concentration in the PQ + AH2QDS group significantly decreased compared to the PQ only group. Additionally, AH2QDS protected the mitochondria of rats and A549 cells and decreased oxidative stress damage, thus improving animal survival and cell viability. Finally, the differentially expressed genes were analysed in the PQ + AH2QDS group and the PQ group by NextGen sequencing, and we verified that Nrf2's expression in the PQ + AH2QDS group was significantly higher than that in the PQ group. Our work identified that AH2QDS can detoxify PQ by reducing PQ uptake and protecting mitochondria while enhancing the body's antioxidant activity.

[Critical quality attribute assessment of big brand traditional Chinese medicine: quality control method of Huangjing Zanyu Capsules based on chemical properties of characteristic components].

The chemical properties of characteristic components are significant to the manufacturing quality control of big brand traditional Chinese medicine. In this study, the Huangjing Zanyu Capsules were used as the research carrier to determine the content of five characteristic components including icraiin, emodin, schisandrin A, 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside, and osthole simultaneously by high-performance liquid chromatography(HPLC). The results showed that the chemical properties of five cha-racteristic components had a good linear relationship(r>0.999 9) within the quantitative range; the relative standard deviations(RSD) was 0.11%-2.0% and 0.25%-2.8% respectively for intra-day and inter-day precision; the RSD of repeatability was 1.8%-2.6%; the RSD of stability within 48 hours was 0.19%-2.8%, and the average recovery rate was 95.52%-100.1%, all meeting the requirements of pharmaceutical quantitative analysis. Additionally, the interval estimation method was used to directly reflect the distribution of samples with abnormal chemical properties of characteristic components, and the results showed ten samples were detected beyound the 95% control line of confidence level. Multivariate statistical process control(MSPC) method was used to monitor the abnormal samples of Huangjing Zanyu Capsules collectively, and the results showed that two samples were beyond the 95% control line of Hotelling's T~2 and three samples beyond the 95% control line of squared prediction error(SPE), indicating consistent quality control of Huangjing Zanyu Capsules. In conclusion, the proposed method is not only accurate and efficient but also a compensation for the traditional single-component quality control method, providing a scientific basis for the quality control in manufacturing process of Huangjing Zanyu Capsules. Furthermore, it could also serve as a reference method for the quality control in manufacturing big brand traditional Chinese medicine.

Mechanisms by which different polar fractions of dissolved organic matter affect sorption of the herbicide MCPA in ferralsol.

Exogenous dissolved organic matter (DOM) modifies the sorption of 4-chloro-2-methylphenoxyacetic acid (MCPA, a polar herbicide) in soil. However, how the chemodiversity and diverse fractions of DOM affect MCPA sorption is still unknown. Here, DOM was extracted from compost and rice straw; the structure-activity correlations between DOM chemodiversity and their effects on MCPA sorption were investigated by redundancy analysis. Moreover, the mechanism involved was explored by spectroscopic techniques, microbeam and modeling. DOM mainly affected MCPA sorption by altering soil surface properties and MCPA complexed form. Hydrophobic neutral (HON) and acid insoluble matter (AIM) were the fractions of DOM that most inhibited MCPA sorption through soil pore blockage, and were related to the humic-like substances with high aromaticity and large molecular weight. The hydrophobic acid fraction (HOA) only showed an intermediate inhibition on the sorption, although the largest competitive sorption occurred. This was because HOA contained abundant aromatic acid and polar groups with moderate polarity. Thus, the reduced effect caused by competitive sorption was partly compensated by the greatest co-sorption by HOA. The hydrophilic matter (HIM) had the weakest inhibition on MCPA sorption, because this fraction was rich in simple sugars, poly- and oligosaccharides, but lacked aryl groups. The results will aid in the risk assessments and prevention of MCPA in DOM-introduced soil.

Pesticides in surface waters of tropical river basins draining areas with rice-vegetable rotations in Hainan, China: Occurrence, relation to environmental factors, and risk assessment.

Pesticides are heavily applied in rice-vegetable rotations in tropical China, yet publicly available information on the contamination and risk of currently used pesticides (CUPs) and legacy pesticides (LPs) in surface waters of river basins draining these areas is very limited. Therefore, in two tropical river basins (Nandu River and Wanquan River basins) dominated by rice-vegetable rotations in Hainan, China, pesticides were analyzed in 256 surface water samples in wet and dry seasons. Forty-one pesticides were detected, and total concentrations ranged from not detectable to 24.2 µg/L. Carbendazim and imidacloprid were the two most prevalent CUPs, detected in 59.8% and 17.7%, respectively, of surface water samples at concentrations above 0.1 µg/L. Chlorpyrifos was the main LP, detected in 9.0% of samples at a concentration above 0.05 µg/L. The fungicides difenoconazole and emamectin benzoate, the herbicide butachlor, and the insecticide acetamiprid occurred in ≥12.5% samples at concentrations above 0.1 µg/L. Surface waters typically (85.2%) contained 5 to 15 residues, with an average of nine. Seasonally, the concentrations of the 41 pesticides were in the order January > July > November > September. Spatially, the composition of the main CUPs (not LPs) was significantly different depending on position in the drainage, which also changed with seasons. Crop and pest types and wet and dry seasons were the key factors controlling the spatiotemporal distribution of CUPs and LPs in surface waters. On the basis of evaluations of the exposures to individual pesticides and the dominant combinations with ≥8 pesticides, multiple pesticides were likely a significant risk to aquatic organisms, although noncarcinogenic and carcinogenic risks to humans were low. This study provides valuable data to better understand pesticide occurrence and ecological risks in river basins draining areas with rice-vegetable rotation systems in tropical China.

Efficacious CO2 Photoconversion to C2 and C3 Hydrocarbons on Upright SnS-SnS2 Heterojunction Nanosheet Frameworks.

In this work, SnS-SnS2 heterostructured upright nanosheet frameworks are constructed on FTO substrates, which demonstrate promising photocatalytic performances for the conversion of CO2 and water to C2 (acetaldehyde) and C3 (acetone) hydrocarbons without H2 formation. With post annealing in designated atmospheres, the photocatalytic activity of the SnS-SnS2 heterostructured nanosheet framework is critically enhanced by increasing the fraction of crystalline SnS in nanosheets through partial transformation of the SnS2 matrix to SnS but not obviously influenced by improving the crystallinity of the SnS2 matrix. DFT calculations indicate that transformed SnS possesses the CO2 adsorption sites with significantly lower activation energy for the rate-determining step to drive efficient CO2 conversion catalysis. The experimental results and DFT calculations suggest that the SnS-SnS2 heterojunction nanosheet framework photocatalyst experiences Z-scheme charge transfer dynamic to allow the water oxidation and CO2 reduction reactions occurring on the surfaces of SnS2 and SnS, respectively. The Z-scheme SnS-SnS2 heterostructured nanosheet framework photocatalyst exhibits not only efficient charge separation but also highly catalytic active sites to boost the photocatalytic activity for CO2 conversion to C2 and C3 hydrocarbons.

The Soil Nutrient Environment Determines the Strategy by Which Bacillus velezensis HN03 Suppresses Fusarium wilt in Banana Plants.

Biological control agents (BCAs) are considered as one of the most important strategies for controlling Fusarium wilt, and bioorganic fertilizer, in particular, has been extensively investigated. However, little is known regarding how a biocontrol microorganism affects the suppression mechanisms when combined with different amendments. In this study, a pot experiment was performed using banana plants to investigate the different mechanisms by which the biocontrol bacterium Bacillus velezensis HN03 (isolated from our laboratory) and amendments suppress Fusarium wilt. The incidence of banana wilt was decreased under HN03 and was reduced further when HN03 was combined with compost, particularly wormcast. In the suppression of Fusarium wilt, HN03 was found to influence the soil environment in various ways. HN03 increased the peroxidase level, which improves plant defense, and was highest when combined with wormcast, being 69 times higher than when combined with cow dung compost. The high accumulation of Mg and P in the "HN03 + wormcast" and Zn and Mn in the "HN03 + cow dung" treatments was negatively correlated with disease incidence. Furthermore, HN03 re-established the microbial community destroyed by the pathogen and further increased the level of suppression in the wormcast. HN03 also enhanced the functional traits of the soil, including defensive mechanism-related traits, and these traits were further enhanced by the combination of HN03 + wormcast.

A Newly Discovered Humic-Reducing Bacterium, Pseudomonas geniculata PQ01, Isolated From Paddy Soil Promotes Paraquat Anaerobic Transformation.

Due to toxicity and persistence of paraquat (a widely used herbicide), eco-friendly remediation approaches to its contamination and effective antidotes to its poisoning have been highly desired and raised increasing concerns. Paraquat degradation was lesser in aerobic soil in comparison with anaerobic soil, and humic-reducing microorganisms (HRMs) play a key role in paraquat anaerobic transformation process. However, the degradation pathways and related mechanisms remain poorly understood. In this study, we investigated the specific interaction mechanisms of the paraquat transformation processes mediated by a humic-reducing strain under anaerobic conditions. A strain of pure culture, designated as PQ01, was successfully isolated from paddy soil using anaerobic enrichment procedure, and identified as Pseudomonas geniculata using phenotypic and phylogenetic analysis. Sucrose, glucose, pyruvate, formic acid, and acetic acid were shown to be favorable electron donors for the reduction of anthrahydroquinone-2,6-disulfonate (AQDS) reduction by PQ01. The strain also had the ability of reducing Fe(III) (hydr)oxides in the presence of sucrose with efficiencies in the order of ferrihydrite > α-FeOOH/γ-FeOOH > γ-Fe2O3 > α-Fe2O3. In the "PQ01 + paraquat + AQDS + sucrose" system, AQDS reduction and paraquat biotransformation by strain PQ01 occurred simultaneously, and the presence of sucrose significantly enhanced the biotransformation. Specific mechanisms of the electron transfer processes are promoted by both PQ01 and AQDS, and proceed in two aspects: (1) paraquat served as electron donor in the anaerobic reduction of AQDS by strain PQ01; (2) AQDS was reduced by PQ01 anaerobic metabolism to produce AH2QDS, which can directly react with paraquat under anaerobic conditions to generate a single crystal compound (molecular formula of the unit structure is C2 6H2 0N2O8S2), causing the paraquat to decline dramatically. In conclusion, this main mechanism included the microbial reduction of AQDS to AH2QDS, followed by the abiotic reaction between AH2QDS and paraquat. This study reported the new characteristics of P. geniculata capable of reducing humics analogs, Fe(III) (hydr)oxides, and paraquat, and proposed a novel electron transformation mechanism of the HRMs' mediated degradation of organic contaminants.

Characteristic of dissolved organic matter polar fractions with variable sources by spectrum technologies: Chemical properties and interaction with phenoxy herbicide.

Dissolved organic matter (DOM) is ubiquitous with high biological and chemical activity. The large intake of DOM from compost, plant residues or soil can modify the behaviors of agrochemicals. Phenoxy herbicide is the third widely used herbicide around the world with both aromaticity and polarity. However, how the diverse fractions of DOM interacting with phenoxy herbicide and the underlying mechanisms remain unknown. Thus, it is crucial to investigate the heterogeneous chemical properties of DOM fractions from variable sources and explore the interactive mechanisms. In this study, polar DOM derived from compost, rice straw and soil were fractionated, and the chemical properties of fractions were analyzed by spectrum technology and the complex interaction with phenoxy herbicide was assessed by infrared spectroscopy. Results showed that hydrophobic acid (HOA) was the largest component (49.6%) in compost DOM, while hydrophilic matter (HIM) was the main component in the polar DOM from rice straw and soil. The 4-chloro-2-methylphenoxyac etic acid (MCPA) as one representative of phenoxy herbicides was used in our study, and the results showed the interaction between different DOM fractions and MCPA was heterogeneous. HOA containing abundant fulvic-like component and polar groups resulted a greatly complex interaction with MCPA mainly via hydrophobic force, ligand exchange and hydrogen bonding. Hydrophobic neutral fraction and acid-insoluble matter showed a medium interaction with MCPA as a result of enrichment with the high aromatic humic-like molecules. Inversely, no significant interaction between HIM and MCPA was observed. Our research revealed that the aromatic framework associated with polar groups in DOM dominated the interaction with phenoxy herbicide, which might affect the bioavailability, toxicity, and mobility of phenoxy herbicide.

Pesticide residues in agricultural topsoil from the Hainan tropical riverside basin: Determination, distribution, and relationships with planting patterns and surface water.

Pesticide residues were assessed in rice-vegetable rotation topsoil from tropical riverside basin. The 256 tropical topsoil samples from the Nandu River Basin (NRB) and Wanquan River Basin (WRB) in Hainan (China) were taken from 2018 to 2019. A total of 32 current-use pesticides (CUPs) and nine legacy pesticides (LPs) were detected using a method based on a QuEChERS technique. The highest residues were from the fungicide carbendazim (257.2 µg/kg) and the insecticide imidacloprid (139.4 µg/kg). The nine LPs (8 organochlorine pesticides and chlorpyrifos) were detected in 84.4% of the samples with mean concentrations ranging from 0.02 to 675.4 µg/kg. The two most commonly detected pesticides were imidacloprid and emamectin benzoate with detection rates of 96.8% and 91.8%, respectively. The highest total concentration of pesticides from the NRB and WRB was detected in July. The highest average number of multi-residues (16) was recorded in January, compared to 14 and 12 in July and November, respectively. There was a significant correlation between the multiple pesticide residues in soil and vegetable planting types (p < 0.01). There was a significant positive correlation between the pesticide number in topsoil and the pesticide number in water (p < 0.01). The multiple pesticide residues found in surface water were consistent with those in topsoil, suggesting a potential risk of water contamination in the rice-vegetable rotation.

Eupatilin Alleviates Lipopolysaccharide-Induced Acute Lung Injury by Inhibiting Inflammation and Oxidative Stress.

BACKGROUND Eupatilin, an active flavone separated from Artemisia species, has various biological activity such as anti-inflammatory activity. The aim of the present study was to find out the influence of eupatilin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. MATERIAL AND METHODS The administration of LPS was used to induce ALI; eupatilin was given 1 hour before the LPS administration. Lung structural damage of rats was analyzed by hematoxylin and eosin staining and the wet/dry lung ratio. The related inflammatory factors and lung injury markers were examined by enzyme-linked immunosorbent assay. The oxidative stress factors were analyzed by corresponding kits. The expression of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) was assayed by western blot and immunohistochemical staining. RESULTS The results showed that eupatilin alleviated LPS-induced structural damage and decreased the wet/dry lung ratio concentration-dependently. Eupatilin decreased the level of surfactant protein (SP)-A, SP-D, and inflammatory factors such as interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and monocyte chemo-attractant protein (MCP)-1. LPS trigged nitric oxide (NO) generation, improved the production of malondialdehyde (MDA) and lactate dehydrogenase (LDH) and decreased the activity of superoxide dismutase (SOD), which were reversed when rats treated with eupatilin in a concentration-dependent way. Besides, the expression of PPAR-a was increased under the treatment of eupatilin. CONCLUSIONS Collectively, eupatilin alleviated LPS-induced ALI through inhibiting inflammation and oxidative stress in a concentration-dependent way, which was likely to be closely related with the activation of PPAR-alpha.

Remediation effectiveness of vermicompost for a potentially toxic metal-contaminated tropical acidic soil in China.

Potentially toxic metal (PTM) contamination coupled with soil acidification has posed a severe threat to agricultural sustainability of tropical region in the world. In this study, a vermicopomst (VC) produced from vermicomposting cattle manure under tropical environment was applied to remediating a tropical acidic soil in Hainan, China. The effectiveness of VC in reducing available PTMs in soils was evaluated by incubation experiments with a Cd, Cr or Ni spiked soil and a Cd contaminated field soil. The dynamic changes of soil physical, chemical and biological properties after VC amendment were determined to understand the mechanisms of PTM immobilization. The results showed that VC amendment significantly reduced 0.01M CaCl2 extractable amounts of Cd, Ni and Cr in the spiked soils, and CaCl2 extractable Cd was reduced by 49.3% when VC was amended to the Cd contaminated field soil. Thermodynamic studies showed that VC had a high adsorption capacity for Cd, Ni and Cr, with the maximum adsorption (obtained from the Langmuir model) of 33.45, 26.17, and 20.88 mg/g, respectively. The reduction in CaCl2 extractable metals after VC amendment was consistent with the order of maximum adsorption of VC for Cd, Ni, and Cr. Vermicompost amendment increased soil pH by 0.7 to 1.5 units, which is positively related with VC rate, but negatively with the decrease in extractable metals. These results indicates that adsorption of metals onto VC and an increase in soil pH after VC amendment are likely responsible for the decreased availability of Cd, Ni, and Cr in the contaminated soil. In addition, the addition of stable organic substances and subsequent formation of water-stable aggregates may be also beneficial for immobilizing PTMs and improving tropical soil quality.

The pharmacokinetics, pharmacodynamics, and mucosal responses to maraviroc-containing pre-exposure prophylaxis regimens in MSM.

OBJECTIVE: HIV Prevention Trials Network 069/AIDS Clinical Trials Group A5305 was a study of 48-week oral pre-exposure prophylaxis (PrEP) regimens in MSM and transgender women. A rectal substudy was included to evaluate drug concentrations in rectal compartment vs. blood, gut-associated lymphoid tissue (GALT) responses to four antiretroviral PrEP regimens [maraviroc (MVC), MVC + emtricitabine (FTC), MVC + tenofovir (TFV) disoproxil fumarate, and TFV disoproxil fumarate + FTC], and to determine whether ARV exposure was associated with ex-vivo suppression of HIV infection in colorectal explants. METHODS: C-C chemokine receptor type 5 (CCR5) genotype was characterized using PCR. At baseline and at Weeks 24, 48, and 49, GALT phenotype was characterized by flow cytometry, rectal biopsies were challenged with HIV-1BaL, and tissue and plasma pharmacokinetics were measured via mass spectrometry. RESULTS: Exposure to MVC was not associated with increased expression of CD4+/CCR5+ HIV target T cells. Significant ex-vivo viral suppression compared with baseline was seen at Weeks 24 and 48, ranging from 1.4 to 1.8 log10 for all study regimens except the MVC-alone arm which did not show statistically significant viral suppression at Week 48. Tissue concentrations of TFV, TFV-diphosphate, and FTC were correlated with viral suppression. CONCLUSION: MVC-containing HIV PrEP regimens did not increase GALT CD4+ T-cell activation or the CD4+/CCR5+ phenotype. No virologic suppression was seen with MVC-alone at Week 48 compared with combination regimens, suggesting MVC monotherapy might be less effective than combination antiretroviral PrEP regimens.