Quantitation and Dietary Risk Assessment of Hexazinone Residue in Blueberry Fruit

In order to determine the residue of hexazinone in blueberry fruit, field experiments in Zhejiang, Jilin, Liaoning and Beijing, China were conducted using 75% hexazinone water dispersible granules. An analytical method was established for determining residual hexazinone in blueberry fruit utilizing ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with an electrospray ionization source in the positive ion mode (ESI+). The samples were extracted with acetonitrile while vortexing, salted out, and then purified on a column packed with primary secondary amine (PSA) and C18 before measurement. The linearity, matrix effect, limit of quantification (LOQ), trueness (recovery rate) and precision (relative standard deviation (RSD)) of the proposed method were studied. Good linearity (r > 0.999 8) was found in the concentration range from 0.000 1 to 0.01 mg/L. The matrix effect was −7.7%. The LOQ was 0.01 mg/kg. The average recovery of hexazinone from blueberry fruit at spiked concentration levels of 0.01, 0.1 and 1.0 mg/kg ranged from 87% to 91%, with a RSD less than 3.7%. The field experiments showed that the residual level of hexazinone in blueberry fruit was below 0.01 mg/kg at 90 and 100 days after application, which was lower than the maximum residue limits (MRL) established in the US, Japan and South Korea (0.6, 0.2 and 0.05 mg/kg, respectively). The results of chronic dietary risk assessment showed that the estimated daily intake of hexazinone for general populations was 0.002 2 mg. The dietary risk quotient (RQ) was only 0.084%, indicating a low risk of dietary hexazinone intake. Therefore, it is recommended that 75% hexazinone water dispersible granules (WG) be applied in a single dose up to 1 800 g/hm2 to blueberry orchards; the pre-harvest interval (PHI) be 90 days

The PRC Police Image: The Trust Index in the Context of Metaphorical Representation on Media Video Hosting Platforms

В статье рассматриваются основные средства метафорической репрезентации полиции Китая в интернет-дискурсе.The article presents an attempt to analyze the main means of metaphorical representation of the Chinese police in the Internet discourse and to reveal the correlation between the generated vector of perception of the police and the data provided in the reports on the China Police Trust Index (or the “transparency index”)

Effects of increased pH and inorganic carbon on growth and photosynthesis in the macroalga Gracilaria lemaneiformis (Gigartinales, Rhodophyta)

The marine red macroalga Gracilaria lemaneiformis usually experiences a changing carbonate system during mariculture. Thalli of G. lemaneiformis collected from Nanao Island, Shantou, China, were cultured in six treatments, with two inorganic carbon (Ci) levels (ambient-Ci, AC; elevated-Ci, EC) and three pH levels (8.2, 9.0, and 9.4), to examine the influence of increased Ci concentrations and high seawater pH on growth and photosynthesis in this farmed algal species. The capacity to extract HCO3- from seawater was relatively stable, as pH compensation points of G. lemaneiformis remained unchanged (9.54-9.59) in the six treatments. Relative growth rate (RGR) and net photosynthetic rate (Pn) of G. lemaneiformis showed no significant differences between treatments of AC and EC at pH 8.2. However, RGR and Pn were higher at EC than at AC at pH 9.4. In addition, RGR and Pn at AC treatments were 67% +/- 12% and 76% +/- 6% lower at pH 9.4 than at pH 8.2, respectively. At AC, total pigment content, effective quantum yield of PSII (Yield), and maximum relative electron transport rate (rETR(m)) were all lower at pH 9.4 than at 8.2. However, reductions of these parameters were significantly ameliorated when thalli of G. lemaneiformis were cultured at EC conditions. We conclude that increasing atmospheric CO2 is conducive to the aquaculture of G. lemaneiformis through the decline of pH and the concurrent increase of Ci in seawater

Effects of stocking density and decreased carbon supply on the growth and photosynthesis in the farmed seaweed, Pyropia haitanensis (Bangiales, Rhodophyta)

During seaweed mariculture the stocking density increases with growth season, which would potentially affect the inorganic carbon availability for photosynthesis. In the present study, the red macroalgal species, Pyropia haitanensis, collected from the cultivation site located at Nan'ao Island, Shantou, China (23(o)20'N, 116(o)40'E), was cultured under high and low stocking density level (5 and 1 g L-1) and two different carbon concentrations (ca. 390 and 20 ppm CO2 in air), to investigate how the stocking density and carbon supply affect the growth and photosynthesis of this alga. The relative growth rate (RGR), nitrate reductase (NR) activity, and photosynthetic rates of high stocking density-grown P. haitanensis thalli were decreased compared with low stocking density-grown thalli. The lowered carbon supply in culture inhibited the RGR, NR activity, photosynthetic rates, and photosystem II activity of the algae. It was shown that high stocking density exhibited similar negative effect compared with reduction of carbon supply on the photosynthesis of P. haitanensis. Moreover, high stocking density aggravated the effect resulting from decreased carbon supply on photosynthesis. We proposed that it is necessary to strive to maintain the relative low stocking density to obtain a sustained high rate of biomass increase in P. haitanensis mariculture

Photoresponsive hydrogel-based soft robot: A review

Soft robots have received a lot of attention because of their great human-robot interaction and environmental adaptability. Most soft robots are currently limited in their applications due to wired drives. Photoresponsive soft robotics is one of the most effective ways to promote wireless soft drives. Among the many soft robotics materials, photoresponsive hydrogels have received a lot of attention due to their good biocompatibility, ductility, and excellent photoresponse properties. This paper visualizes and analyzes the research hotspots in the field of hydrogels using the literature analysis tool Citespace, demonstrating that photoresponsive hydrogel technology is currently a key research direction. Therefore, this paper summarizes the current state of research on photoresponsive hydrogels in terms of photochemical and photothermal response mechanisms. The progress of the application of photoresponsive hydrogels in soft robots is highlighted based on bilayer, gradient, orientation, and patterned structures. Finally, the main factors influencing its application at this stage are discussed, including the development directions and insights. Advancement in photoresponsive hydrogel technology is crucial for its application in the field of soft robotics. The advantages and disadvantages of different preparation methods and structures should be considered in different application scenarios to select the best design scheme

Study on the Pressure Relief Mechanism and Engineering Application of Segmented Enlarged-Diameter Boreholes

Ensuring the stability of surrounding rock while conducting pressure relief is key to roadway stability control and preventing rock burst. In this paper, segmented enlarged-diameter borehole destressing technology is proposed. The stress distribution around the borehole is analysed based on the theory of elasto-plastic mechanics, and the mechanism of pressure relief for segmented enlarged-diameter boreholes is studied. Secondly, The effects of the diameter of enlarged-diameter section, length of the enlarged-diameter section, and borehole space on pressure relief and roadway deformation were investigated. Finally, the optimal drilling parameters for Tangkou coal mine 6307 working face are analysed. The key parameters of segmented enlarged-diameter borehole pressure relief technology for the 6307 working face were determined and applied in field practice. Field monitoring results showed that the accumulated energy can be effectively reduced using segmented enlarged-diameter pressure relief boreholes, effectively controlling roadway deformation and providing reference for rock burst prevention and roadway stability control

Effects of Different Hydrolysis Methods on the Hydrolysate Characteristics and Photo-Fermentative Hydrogen Production Performance of Corn and Sorghum Straw

The effects of hydrolysis methods (hydrothermal, acid, alkali, hydrothermal-enzyme, acid-enzyme, and alkali-enzyme) on hydrolysate characteristics and photo fermentative hydrogen production (PFHP) of corn straw (CS) and sorghum straw (SS) were investigated. The optimum production of reducing the sugar of straw in different solvent environments was studied by one-step hydrolysis and co-enzymatic hydrolysis pretreatment through a 3,5-dinitrosalicylic acid method. The hydrogen production process by photolytic fermentation of hydrolysates of Rhodobacter sphaeroides HY01 was further analyzed through a gas chromatograph, including the differences in accumulated PFHP yield, chemical oxygen consumption (COD), and volatile fatty acid (VFA) composition. The results showed that the highest reducing sugar yield was obtained by the acid method among one-step hydrolysis. In contrast, acid-enzyme hydrolysis can further increase the reducing sugar yield, which reached 0.42 g·g−1-straw of both straws. Both CS and SS had the highest hydrogen yield from acid-enzyme hydrolysate, 122.72 ± 3.34 mL·g−1-total solid of straw (TS) and 170.04 ± 4.12 mL·g−1-TS, respectively, compared with their acid hydrolysates with 40.46% and 10.53% higher hydrogen yields, respectively. The use of enzymatic hydrolysis showed a significantly higher hydrogen yield for CS compared to SS, indicating that acid hydrolysis was more suitable for SS and acid-enzyme hydrolysis was more suitable for CS

NCs-Delivered Pesticides: A Promising Candidate in Smart Agriculture

Pesticides have been used extensively in the field of plant protection to maximize crop yields. However, the long-term, unmanaged application of pesticides has posed severe challenges such as pesticide resistance, environmental contamination, risk in human health, soil degradation, and other important global issues. Recently, the combination of nanotechnology with plant protection strategies has offered new perspectives to mitigate these global issues, which has promoted a rapid development of NCs-based pesticides. Unlike certain conventional pesticides that have been applied inefficiently and lacked targeted control, pesticides delivered by nanocarriers (NCs) have optimized formulations, controlled release rate, and minimized or site-specific application. They are receiving increasing attention and are considered as an important part in sustainable and smart agriculture. This review discussed the limitation of traditional pesticides or conventional application mode, focused on the sustainable features of NCs-based pesticides such as improved formulation, enhanced stability under harsh condition, and controlled release/degradation. The perspectives of NCs-based pesticides and their risk assessment were also suggested in this view for a better use of NCs-based pesticides to facilitate sustainable, smart agriculture in the future

Limonene formulation exhibited potential application in the control of mycelial growth and deoxynivalenol production in Fusarium graminearum

Preventing grain from fungi and subsequent mycotoxins contamination has attracted notable attention. Present study demonstrated the limonene-formulated product Wetcit®, might be a biocontrol agent and potential alternative to synthetic fungicides to control Fusarium graminearum growth and deoxynivalenol (DON) production. The limonene formulation exhibited antifungal activity against F. graminearum with the EC50 at 1.40 μl/ml, electron microscopy and staining analysis showed limonene formulation could significantly decrease the quantity, length and septa of conidia, caused hyphal break and shrink, damaged the structures of cell membrane, cell wall, vacuoles and organelles in the hypha. Further study revealed the antifungal and antitoxic mechanism of limonene formulation against F. graminearum, limonene formulation significantly inhibited the toxisome and DON formation, was associated with the down-regulation of trichothecenes biosynthesis genes expression and many energy metabolism pathways as well as the inhibition of lipid droplets, the disturbed energy homeostasis and intracellular structures might ultimately inhibit fungal growth and DON production. In addition, limonene formulation enhanced the antifungal activity of triazole fungicides tebuconazole and mefentrifluconazole against F. graminearum, indicated limonene formulation has valuable potential as a bio-alternative fungicide and eco-friendly compound preparation for the effective management of F. graminearum and DON contamination in agriculture