FHL1: A novel diagnostic marker for papillary thyroid carcinoma.

Although there are clear morphologic criteria for the diagnosis of papillary thyroid carcinoma (PTC), when the morphology is untypical or overlaps, accurate diagnostic indicators are necessary. Since few studies investigated the role of down-regulated genes in PTC, this article aims to further explore the molecular markers associated with PTC. We conducted bioinformatics analysis of gene microarrays of PTC and normal adjacent tissues. Besides, quantitative real-time quantitative polymerase chain reaction array and immunohistochemical staining were used to investigate the expression of the major down-regulated genes. The results indicated that several important down-regulated genes, including TLE1, BCL2, FHL1, GHR, KIT, and PPARGC1A were involved in the process of PTC. Compared to normal adjacent tissues, the mRNA expression of the major genes was down-regulated in PTC (p＜0.05). Immunohistochemically, FHL1 shows negative or low expression in PTC tissues (p＜0.05). BCL2 did not show a significant difference between PTC and normal thyroid tissues (p > 0.05). TLE1, KIT, PPARGC1A and GHR showed negative expression in both tumor and normal tissues. These results suggested that FHL1 could serve as a novel tumor marker for precise diagnosis of PTC.

Photolysis of dinotefuran and nitenpyram in water and ice phase: Influence mechanism of temperature over photolysis.

Neonicotinoids are widely used pesticides around the world, but the photolysis of neonicotinoids in cold agricultural region are still in blank. This paper aimed to study the influence of cold temperature over photolysis of neonicotinoids. To this end, the photolysis rates and photoproducts of dinotefuran and nitenpyram in water, ice and freeze-thawing condition were determined. Coupled with quantum chemistry calculation, the influence mechanisms of temperature and medium were investigated. The results showed the photolysis rates of neonicotinoids in water condition slightly declined with the lowered temperature due to the photolysis reactions were endothermic reactions. However, the photolysis rates increased by 89.8 %, 59.2 %, 49.4 % and 9.5 % for dinotefuran and nitenpyram in ice and thawing condition, respectively. This phenomenon was posed by the concentration-enhancing effect and change of photo-chemical properties of neonicotinoids in ice condition, which included lowered bond cleavage energy, lowered first excited singlet state energy and expanded light absorption range. The photolysis pathways of the two neonicotinoids did not change in different medium, but the concentration of carboxyl products was relatively higher than that of water condition due to the more amounts of reactive oxygen species in ice medium, which might increase the secondary pollution risk after ice-off in spring due to the higher ecotoxicity to nontarget organism of these photoproducts. The influence of cold temperature and medium change should be considered for the environmental fate and risk assessment of neonicotinoids in cold agricultural region.

Purification mechanism of city tail water by constructed wetland substrate with NaOH-modified corn straw biochar.

The pollution of corn straw to the environment had attracted much attention. The preparation and alkali modification of corn straw biochar as the constructed wetland (CW) substrate was conducive to solving the environment pollution caused by straw and improving the purification effect of CW. The NaOH modification mechanism of corn straw biochar was analyzed by measuring the surface morphology, element content, specific surface area (SSA), pore volume, crystal structure, surface functional groups and CO2 adsorption. Biochar prepared under relatively optimal NaOH-modified conditions was used as the vertical flow CW substrate to treat city tail water. The results showed that controlling the modification condition of NaOH (< 1.0 mol·L-1, ≤ 24 h) was conducive to prevent the biochar structure destruction and C element reduction. The SSA and pore volume of NaOH (0.1 mol·L-1) modified biochar are 360 m2·g-1 and 0.109 cm3·g-1, respectively. The biochar adsorption for CO2 conformed to the Langmuir and Freundlich isothermal adsorption theoretical model (R2 > 0.9). The maximum adsorption capacity of CO2 by modified biochar with NaOH (0.1 mol·L-1) was 64.516 cm3·g-1 and increased by 10.3%. The city tail water treated by CW with plants showed that the removal rates of ammonia nitrogen, total nitrogen and nitrate nitrogen reached about 90%. The research results improved the utilization value of straw, realized straw carbon sequestration and promoted the progress of CW technology.

Physicochemical modification of corn straw biochar to improve performance and its application of constructed wetland substrate to treat city tail water.

Corn straw is rich in resources, and the preparation of biochar as the constructed wetland (CW) substrate is an effective measure to realize high-value resource utilization. The objective of this paper was to improve the treatment effect of CW on city tail water, the freeze-thaw cycles (FTCs) modification and chemical modification (KMnO4, NaOH and H2SO4) of straw biochar and the utilization of modified straw biochar in CW were studied. The modification characteristics of straw biochar were discussed through scanning electron microscope, element determination, pore structure determination, X-ray diffraction analysis, Fourier transform infrared reflection analysis, CO2 adsorption and desorption experiment and application experiment of CW (no plants and plants). The results show that under the influence of strong oxidation of KMnO4, the combination of KMnO4 and FTCs modification is easy to cause the destruction of biochar structure, and the content of carbon element is reduced. Except for the combined modification of NaOH and FTCs, other composite modifications have little effect on the crystal structure and functional groups of straw biochar. The adsorption capacity of CO2 by FTCs modified biochar increased by 20.4%, and the adsorption capacity of CO2 by H2SO4 and FTCs composite modified biochar increased by 23.0%. The effect of H2SO4 modification of straw biochar based on FTCs modification is obviously better than that of NaOH and KMnO4. The research results are of great significance to improve the material structure of biochar and the purification effect of CW on city tail water.

GIS-based for prediction and prevention of environmental geological disaster susceptibility: From a perspective of sustainable development.

Geological disasters seriously threaten the safety of human life, property, ecological resources, and the environment. Effective control of geological disasters is the focus of achieving sustainable social development. The Helong City (Jilin Province, China) was selected as the case study. Combined with GIS technology, a new integrated prediction model of geological disaster susceptibility was developed to improve the accuracy of geological disaster assessment, reduce the cost of geological disaster treatment, and ensure the sustainable development of ecological environment. The research results showed that elevation and normalized difference vegetation index (NDVI) were the key factors affecting susceptibility. Compared with the conventional model, the accuracy of the developing integrated model FR-DT and FR-RF was improved by more than 6%, and the disaster points were more concentrated in the high susceptibility zone. Statistical results of disaster treatment cost estimation and gross domestic product (GDP) value showed that the integrated model can save about 10% of treatment cost, and the ratio of total GDP/disaster governance cost was higher. The performance of the integrated model FR-DT and FR-RF had obvious advantages over the conventional model in terms of prediction accuracy, prevention pertinence, and prevention cost. These research results promote the advancement of geological disaster prevention and control technology, ensure the safety of the geological environment, and are of great significance to the sustainable development of the regional economy.

Study on clogging mechanisms of constructed wetlands from the perspective of wastewater electrical conductivity change under different substrate conditions.

Constructed wetland (CW) has obvious advantages in wastewater treatment of medium and small towns. However, there is a lack of health monitoring research on CW system clogging. The electrical conductivity (EC) of wastewater purified by CW is related to the concentration of pollutants, which can reflect the CW clogging. The objectives of this study are to reveal the mechanisms of CWs substrate clogging from the perspective of wastewater EC changes, and provide an important reference for the health evaluation of CWs. The EC changes of nine CWs substrates (quartz sand, zeolite, gravel, coarse sand, straw biochar, sludge biochar, clay ceramsite, fly ash ceramsite and shale ceramsite) under different conditions (purified water, wastewater and wastewater + NaCl) were tested, and comparative analysis was used to reveal the influence of different substrate materials on the change of wastewater EC. The results show that the adsorption ability of substrate material isn't the main factor affecting the EC of wastewater, and the soluble component in the material is the important factor to cause the difference of EC increment. Under the condition of 0.4-1.0 g L-1 NaCl concentration, the adsorption of substrate materials had little effect on the EC of wastewater, and the effect of NaCl used in CW tracer experiment was good. Quartz sand, coarse sand, gravel and sludge biochar have little influence on the change of wastewater EC. Other materials that have great influence on the change of wastewater EC can be treated by modifying or controlling the mixing ratio. The results are of great significance to reveal the clogging state of CW system and to carry out health assessment research.

Preparation of ceramsite from municipal sludge and its application in water treatment: A review.

Municipal sludge is a solid waste material, and resource utilization is the optimal way to dispose of this material. The amount of municipal sludge produced in China is large, and it can be used in the preparation of ceramsite. The content of Al2O3 in drinking water treatment sludge is significantly higher than that in wastewater treatment sludge, while the content of K2O, Na2O and MgO in the two kinds of sludge is similar. When sludge is used to prepare ceramsite, the amount of sludge in most raw materials for ceramsite is less than 50%. The bulk density of the prepared sludge ceramsite is less than 1000 kg m-3, and the highest water absorption rate is close to 40%. The leaching content of heavy metals in municipal sludge-based ceramsite is within the standard health safety limit, and heavy metals are better stabilized. The fitting effect of the pseudo-second-order kinetic equation of the dynamic adsorption of sludge ceramsite is obviously better than that of the pseudo-first-order kinetic equation. Sludge ceramsite used in bio-filter media and constructed wetland (CW) substrates is good able to purify wastewater. In the future, the preparation method of municipal sludge ceramsite and purification research of CW substrates based on sludge ceramsite need to be further improved.

Response surface optimization, combustion characteristics and kinetic analysis of mixed fuels of Fenton/CaO conditioned municipal sewage sludge and rice husk.

The co-combustion characteristics and kinetics of Fenton/CaO conditioned MSS, and biomass rice husk (RH) are studied by thermogravimetry, and the condition optimization was carried out by response surface methodology (RSM). The results show that the mixed fuel with RH is helpful to decrease Ti and Tb values and increase combustion characteristic index (CCI). The CCI of MSS after conditioning is 0.59-0.88 times lower than that of the pure MSS. In addition, the total Em of S2, MSS/RH mixed combustion after Fenton/CaO conditioning is lower, the combustion reactivity is stronger. According to RSM, the optimum conditions are considered to be: RH mixing ratio 56%, Fenton/CaO conditioner dosage 147 mg g-1 dry solids, heating rate 30 K min-1, the maximum CCI 25.3305 × 10-7%2 °C-3 min-2, and the minimum Em 10.6403 kJ min-1. This study supplies new insights into combustion technology of sludge.

Scaling Effects on Chlorophyll Content Estimations with RGB Camera Mounted on a UAV Platform Using Machine-Learning Methods.

Timely monitoring and precise estimation of the leaf chlorophyll contents of maize are crucial for agricultural practices. The scale effects are very important as the calculated vegetation index (VI) were crucial for the quantitative remote sensing. In this study, the scale effects were investigated by analyzing the linear relationships between VI calculated from red-green-blue (RGB) images from unmanned aerial vehicles (UAV) and ground leaf chlorophyll contents of maize measured using SPAD-502. The scale impacts were assessed by applying different flight altitudes and the highest coefficient of determination (R2) can reach 0.85. We found that the VI from images acquired from flight altitude of 50 m was better to estimate the leaf chlorophyll contents using the DJI UAV platform with this specific camera (5472 × 3648 pixels). Moreover, three machine-learning (ML) methods including backpropagation neural network (BP), support vector machine (SVM), and random forest (RF) were applied for the grid-based chlorophyll content estimation based on the common VI. The average values of the root mean square error (RMSE) of chlorophyll content estimations using ML methods were 3.85, 3.11, and 2.90 for BP, SVM, and RF, respectively. Similarly, the mean absolute error (MAE) were 2.947, 2.460, and 2.389, for BP, SVM, and RF, respectively. Thus, the ML methods had relative high precision in chlorophyll content estimations using VI; in particular, the RF performed better than BP and SVM. Our findings suggest that the integrated ML methods with RGB images of this camera acquired at a flight altitude of 50 m (spatial resolution 0.018 m) can be perfectly applied for estimations of leaf chlorophyll content in agriculture.

Modified Red Blue Vegetation Index for Chlorophyll Estimation and Yield Prediction of Maize from Visible Images Captured by UAV.

The vegetation index (VI) has been successfully used to monitor the growth and to predict the yield of agricultural crops. In this paper, a long-term observation was conducted for the yield prediction of maize using an unmanned aerial vehicle (UAV) and estimations of chlorophyll contents using SPAD-502. A new vegetation index termed as modified red blue VI (MRBVI) was developed to monitor the growth and to predict the yields of maize by establishing relationships between MRBVI- and SPAD-502-based chlorophyll contents. The coefficients of determination (R2s) were 0.462 and 0.570 in chlorophyll contents' estimations and yield predictions using MRBVI, and the results were relatively better than the results from the seven other commonly used VI approaches. All VIs during the different growth stages of maize were calculated and compared with the measured values of chlorophyll contents directly, and the relative error (RE) of MRBVI is the lowest at 0.355. Further, machine learning (ML) methods such as the backpropagation neural network model (BP), support vector machine (SVM), random forest (RF), and extreme learning machine (ELM) were adopted for predicting the yields of maize. All VIs calculated for each image captured during important phenological stages of maize were set as independent variables and the corresponding yields of each plot were defined as dependent variables. The ML models used the leave one out method (LOO), where the root mean square errors (RMSEs) were 2.157, 1.099, 1.146, and 1.698 (g/hundred grain weight) for BP, SVM, RF, and ELM. The mean absolute errors (MAEs) were 1.739, 0.886, 0.925, and 1.356 (g/hundred grain weight) for BP, SVM, RF, and ELM, respectively. Thus, the SVM method performed better in predicting the yields of maize than the other ML methods. Therefore, it is strongly suggested that the MRBVI calculated from images acquired at different growth stages integrated with advanced ML methods should be used for agricultural- and ecological-related chlorophyll estimation and yield predictions.

Distribution, sources and health risk assessment of contaminations in water of urban park: A case study in Northeast China.

This case study was performed to determine whether the pollutants in water of urban park could bring health risk to human engaging in water-related activities such as swimming and provide evidence demonstrating the critical need for strengthened recreational water resources management of urban park. TN, NH4+-N, TP, Cu, Mn, Zn, Se, Pb, As, Cd and Cr(VI) contents were determined to describe the spatial distribution of contaminations; sources apportionment with the method of correlation analysis, factor analysis and cluster analysis were followed by health risk assessment for swimmers of different age groups. The results reveal that element contents in all sites do not exceed Chinese standard for swimming area and European Commission standard for surface water; all detected elements except Cr(VI) have a tendency to accumulate in the location of lake crossing bridge; Mn and Zn are considered to have the same pollution source including geogenic and anthropogenic sources by multivariable analysis. Carcinogenic risks of different age groups descend in the same order with non-carcinogenic risks. Among all elements, Zn and Mn contribute the lowest non-carcinogenic risk (5.1940E-06) and the highest non-carcinogenic risk (7.9921E-04) through skin contact pathway, respectively. The total average personal risk for swimmers in swimming area is 1.9693E-03, and this site is not suitable for swimming. Overall, it is possible that swimmers are exposed to risk via the dermal route when carrying out water-related activities, it is recommended that necessary precautions and management should be taken in other similar locations around the world.

Study of the potential of barnyard grass for the remediation of Cd- and Pb-contaminated soil.

In this study, the microwave digestion method was used to determine total cadmium (Cd) and lead (Pb) concentrations, the BCR method was used to determine different states of Cd and Pb, and atomic absorption spectroscopy (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to determine Cd and Pb concentrations in simulated soil and barnyard grass before and after planting barnyard grass to provide a theoretical basis for the remediation of Cd- and Pb-contaminated soil. The results showed that the bioconcentration factor changes with different Cd concentrations are relatively complex and that the removal rate increases regularly. The 100 mg kg-1 Cd treatment had the highest removal rate, which reached 36.66%. For Pb, the bioconcentration factor decreased and tended to reach equilibrium as the Pb concentration increased. The highest removal rate was 41.72% and occurred in the 500 mg kg-1 Pb treatment; however, this removal rate was generally lower than that of Cd. In addition, the reduction state had the highest change rate, followed by the residual, acid soluble and oxidation states. For Pb, the residual state has the highest change rate, followed by the acid soluble state, reduction state and oxidation state. In addition, a significant correlation was observed between the soil Pb and Cd concentrations and the concentrations of Pb and Cd that accumulated in the belowground biomass of the barnyard grass, but no significant correlation was observed between the soil Pb and Cd concentrations and the amounts of Pb and Cd that accumulated in the aboveground biomass of the barnyard grass. The highest transfer factor of Cd was 0.49, which occurred in the 5 mg kg-1 Cd treatment. The higher transfer factor of Pb was 0.48 in the 100 mg kg-1 Pb treatment. All of these factors indicate that the belowground biomass of barnyard grass plays a more important role in the remediation of Cd- and Pb-contaminated soils than the aboveground biomass of barnyard grass. Remediation should occur through phytostabilization. Thus, with its strong adaptability and lush growth, barnyard grass can be applied as a pioneer species for the phytoremediation of Cd- and Pb-contaminated soils.

Ecological risk assessment of heavy metals in soils surrounding oil waste disposal areas.

More attention is being devoted to heavy metal pollution because heavy metals can concentrate in higher animals through the food chain, harm human health and threaten the stability of the ecological environment. In this study, the effects of heavy metals (Cu, Cr, Zn, Pb, Cd, Ni and Hg) emanating from oil waste disposal on surrounding soil in Jilin Province, China, were investigated. A potential ecological risk index was used to evaluate the damage of heavy metals and concluded that the degree of potential ecological damage of heavy metals can be ranked as follows: Hg > Cd > Pb > Cu > Ni > Cr > Zn. The average value of the potential ecological harm index (Ri) is 71.93, thereby indicating light pollution. In addition, this study researched the spatial distribution of soil heavy metals by means of ArcGIS (geographic information system) spatial analysis software. The results showed that the potential ecological risk index (R) of the large value was close to the distance from the oil waste disposal area; it is relatively between the degree of heavy metals in soil and the distance from the waste disposal area.

Impact of aerosol concentration changes on carbon sequestration potential of rice in a temperate monsoon climate zone during the COVID-19: a case study on the Sanjiang Plain, China.

The emission reduction of atmospheric pollutants during the COVID-19 caused the change in aerosol concentration. However, there is a lack of research on the impact of changes in aerosol concentration on carbon sequestration potential. To reveal the impact mechanism of aerosols on rice carbon sequestration, the spatial differentiation characteristics of aerosol optical depth (AOD), gross primary productivity (GPP), net primary productivity (NPP), leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FPAR), and meteorological factors were compared in the Sanjiang Plain. Pearson correlation analysis and geographic detector were used to analyze the main driving factors affecting the spatial heterogeneity of GPP and NPP. The study showed that the spatial distribution pattern of AOD in the rice-growing area during the epidemic was gradually decreasing from northeast to southwest with an overall decrease of 29.76%. Under the synergistic effect of multiple driving factors, both GPP and NPP increased by more than 5.0%, and the carbon sequestration capacity was improved. LAI and FPAR were the main driving factors for the spatial differentiation of rice GPP and NPP during the epidemic, followed by potential evapotranspiration and AOD. All interaction detection results showed a double-factor enhancement, which indicated that the effects of atmospheric environmental changes on rice primary productivity were the synergistic effect result of multiple factors, and AOD was the key factor that indirectly affected rice primary productivity. The synergistic effects between aerosol-radiation-meteorological factor-rice primary productivity in a typical temperate monsoon climate zone suitable for rice growth were studied, and the effects of changes in aerosol concentration on carbon sequestration potential were analyzed. The study can provide important references for the assessment of carbon sequestration potential in this climate zone.

Research on the impact mechanism of changes in the production of medical solid waste in China before and after COVID-19.

The changes of medical solid waste (MSW) output in recent years have had a significant impact on the spread of the virus. There is a high-risk transmission of MSW in various stages such as storage, transportation, and treatment during the COVID-19. To cope with the risks brought by the epidemic, normalized prevention consumes a large amount of protective clothing, medical masks, goggles, packaging bags, and other related medical supplies. There is a significant uncertainty in the amount of MSW output that poses a risk of COVID-19 infection in the event of an emergency, which increases the difficulty of collecting and handling epidemic prevention MSW. The analysis of MSW data from 2000 to 2022 found a stable growth trend before 2019. However, the MSW data was a sudden increase trend from 2020 to 2022, and the COVID-19 in China was characterized by an initial stage, an outbreak stage, and a stable growth stage. The range of MSW output during the epidemic was (1.19-1.75) × 106 t a-1. The amount of MSW was approximately 1.19 × 106 t a-1 during the normalized epidemic period, and its treatment cost was as high as 3.57 × 109 yuan (RMB)·a-1. The distribution of MSW output was uneven due to factors such as climate conditions, population data, and local economy. This study has important reference value for epidemic medical material reserves and MSW treatment.

Study on H2SO4-modified corn straw biochar as substrate material of constructed wetland.

The high value resource utilization of corn straw is a long-term problem at present and in the future. Biochar preparation is an important utilization way of corn straw. The research on city tail water treated by constructed wetland (CW) with biochar was carried out to further increase the wastewater treatment capacity of the CW. Surface characterization, structural characteristics, and adsorption of straw biochar modified by different acids were measured. The study found that the ability of H2SO4 to remove ash from biochar was stronger than other acids and H2SO4-biochar was easy to be cleaned without H2SO4 residue. The performance of biochar modified by H2SO4 was obviously better than other acids, and the biochar adsorption was enhanced. The modification of biochar substrate modified by H2SO4 in CW reduced the change of electrical conductivity (EC) and promoted denitrification. H2SO4-modified biochar promoted the absorption of N and P by Iris pseudacorus L. The compound modification effect of straw biochar was obvious. The results revealed the acid modification characteristics of straw biochar, which were beneficial for increasing the wastewater treatment rate by CW. This study will promote the sustainable development of CW.

Dynamic simulation analysis of city tail water treatment by constructed wetland with biochar substrate.

Constructed wetland (CW) is an important method of ecological water treatment, and CW has obvious advantage in treating low-pollution water. In order to improve the treatment efficiency of CW, the first-order and second-order kinetics simulations of pollutant removal in CW were carried out to optimize operating conditions. The experimental study of city tail water treatment under unmodified biochar (different additions) or different modified biochar conditions showed that the first-order kinetic equation relatively accurately reflect the removal of pollutants by substrate. The relatively optimal range of biochar addition (2.21-3.79%) in the first-order kinetic analysis covered the relatively optimal mass ratio (2.95%). The first-order kinetic equation fitting showed that the half-life of ammonia nitrogen removal by NaOH (0.1 mol·L-1)-modified biochar was reduced by about 10% without plant. The half-life of total phosphorus removal by KMnO4 (0.1 mol·L-1) modified biochar was reduced by about 50%. The half-life of chemical oxygen demand removal by H2SO4 (0.75 mol·L-1) + 8 freeze-thaw cycles modified biochar was reduced by about 9.0%. When the half-life was small, the pollutant removal rate was high. The results of this study further confirmed the effectiveness of the simulation results of pollutant removal in CW with biochar by the first-order kinetic equation. This study further optimized the CW operating conditions and improved the treatment efficiency of nitrogen and phosphorus in the CW.

Characteristic of KMnO4-modified corn straw biochar and its application in constructed wetland to treat city tail water.

Biochar prepared from straw as constructed wetland (CW) substrate reduces straw pollution and simultaneously promotes the wastewater treatment efficiency of CW. In order to further analyze the pollutant removal mechanism of KMnO4-modified biochar substrate, the KMnO4-modified biochar was characterized. The experiment on city tail water treatment by CW with biochar was analyzed. The research showed that the surface property improvement on KMnO4 (0.1 mol/L)-modified biochar was the most obvious. The biochar modified by 0.1 mol/L KMnO4 increased the SSA and the number of oxygen functional groups and alcohol hydroxyl. KMnO4-modified biochar improved the removal efficiency of NO3--N in CW. KMnO4-modified biochar substrate with plants improved the TP removal efficiency (about 45%). KMnO4 as modifier reduced the influence of biochar on electrical conductivity tracing experiment. This study will improve the utilization value of straw and the removal efficiency of CW.

Blocking Cx43 alleviates neuropathic pain in rats with chronic constriction injury via the P2X4 and P38/ERK-P65 pathways.

Neuropathic pain is a growing concern in the medical community, and studies on new analgesic targets for neuropathic pain have become a new hot spot. Whether Connexin43 (Cx43) has a key role in neuropathic pain mediated by the purinergic 2X4 (P2X4) receptor in rats with chronic constriction injury (CCI) was explored in this study. Our experimental results show that blockade of Cx43 could attenuate neuropathic pain in rats suffering from CCI via the P2X4, p38, ERK, and NF-kB signalling pathways. These results suggest that Cx43 may be a promising therapeutic target for the development of novel pharmacological agents in the management of neuropathic pain.

Photolysis and photo-enhanced toxicity of three novel designed neonicotinoids: Impact of novel modifying groups.

Three novel neonicotinoids (cycloxaprid, flupyradifurone and sulfoxaflor) were designed to reduce the biotoxicity for non-target organisms. These neonicotinoids were photolyzed under light radiation, but it was unclear for the photo-enhanced toxicity and influences of the novel modifying group of the three neonicotinoids. The photolysis and photo-enhanced toxicity experiments were performed for the three neonicotinoids, coupled with quantum chemistry calculation, the mechanisms of photolysis, photo-enhanced toxicity and the influences of novel modifying groups were analyzed. The results showed the photolysis pathways were enriched as compared with previous neonicotinoids due to the composition of modifying groups, singlet oxygen and hydroxyl participated the photolysis of cycloxaprid and flupyradifurone. All tested neonicotinoids exhibited photo-enhanced toxicity to Vibrio fischeri. Due to the difference of photolysis mechanism and toxicity to V. fischeri, the photo-enhanced toxicity curves showed diverse variation when histidine, tert-butanol or dissolved organic matters was in presence of the test solutions. The impact of novel modifying groups over photolysis and photo-enhanced toxicity were analyzed based on the comparison with previous neonicotinoids, theoretically predicted UV-Vis spectra and photo-physical/chemical property descriptors. The data showed the composition of novel modifying group increased the light absorption and photo-chemical activities for the three neonicotinoids.