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Phoxim is a pesticide extensively applied in mulberry fields, and residues may persist on leaves even after the recommended pre-harvest interval. However, the potential risks of these residues to Bombyx mori L. (Lepidoptera: Bombycidae) have long been overlooked. The results demonstrated that chronic low-dose exposure from the second to fifth instars significantly impaired silkworm development and silk production. Specifically, larvae in the 0.316 μg/mL treatment group (1/2 LC50) exhibited a significant reduction in body weight, while the cocoon shell ratio was significantly decreased in both the 0.079 μg/mL (1/8 LC50) and 1/2 LC50 groups. Cocoon deformities were observed in the 0.032 μg/mL (1/20 LC50), 1/8 LC50, and 1/2 LC50 groups. Histopathological analysis revealed silk gland damage in the treatment groups, with severity increasing with higher phoxim concentrations. Biochemical analyses indicated elevated malondialdehyde (MDA) levels accompanied by increased superoxide dismutase (SOD) and peroxidase (POD) activities. Notably, phoxim exposure selectively reduced juvenile hormone (JH) titers without affecting ecdysone titers. JH-regulated genes including the receptors Met1 and Met2, and transcription factors Kr-h1 and Dimm were downregulated, accompanied by suppressed expression of the fibroin synthesis gene Fib-H. These results collectively indicate that chronic low-concentration phoxim exposure disrupts endocrine regulation, damages silk gland integrity, and ultimately reduces silk production in silkworm.

As the first barrier of desert highway protection, sand-blocking fence is very important to the safety of the line. Based on the background of Wuma Expressway, this paper uses CFD numerical simulation to study the wind and sand-blocking effect of sand-blocking fence with different heights. The results show that: (1) Between the first and second sand-blocking fences, when the height of sand-blocking fence is 2m, 2.5m, 3.0m and 3.5m, the wind speed near the surface (0.1m ~ 0.3m) is reduced by 87% ~ 97% of the initial wind speed. Between the second and third sand-blocking fences, when the height of sand-blocking fence is 2.5m, the increase of wind speed is 13.87% lower than that of 2m height. The decrease is the largest, and sand particles are easy to deposit here in large quantities. When the height is 2.5m and above, the windbreak efficiency is greater than 90%, and the windbreak effect is significantly improved. (2) The change of sand barrier height has a significant effect on the windbreak efficiency between the second and third sand barriers. (3) Among the three sand-blocking fences, when the height of the sand-blocking fence is 2.5m, the thickness of the sand is 50.51% and 58.33% higher than that of the 2m high sand-blocking fence, and the sand-blocking effect is the most significant. After the height is increased to 3.5m, the thickness of the sand is no longer increased. (4) The height of sand-blocking fence is 2.5m, and the area of sand at the top of embankment is obviously reduced. The area of sand volume fraction 0.55–0.6 is 73.44% lower than that of 2m sand-blocking fence, and the effect of wind and sand prevention is the best.

Imidacloprid (IMI) is the first-generation neonicotinoid insecticide. But, the long-term use of IMI as a pesticide has caused severe water pollution. Recently, the toxicity of IMI to aquatic organisms has received increasing attention. This study aimed to investigate the absorption and distribution of IMI in various tissues (gills, intestine, liver, muscle, brain and gonads) of goldfish through short-term and continuous exposure tests over 28 days. The results of short-term exposure indicated that the concentration of IMI and its metabolites in tissues at the transfer stage decreased steadily after 1 day of 40 mg/L IMI water treatment and was below the detection limit after 3 days. Continuous exposure for 28 days at various treatment concentrations showed that the concentrations of IMI and its metabolites differed significantly among the different tissues of the goldfish. In the 20 mg/L treatment group (S1), the highest concentration of IMI was found in the liver (12.04 μg/gtissue), followed by the intestine (9.91 μg/gtissue), muscle (6.20 μg/gtissue), gill (6.11 μg/gtissue), gonads (5.22 μg/gtissue) and brain (2.87 μg/gtissue). In the 40 mg/L treatment group (S2), the order of the tissue concentrations was similar to that of the S1 group, with the highest concentration observed in the liver (12.04 μg/gtissue), followed by the intestine (9.91 μg/gtissue), muscle (6.20 μg/gtissue), gill (6.11 μg/gtissue), gonads (5.22 μg/gtissue) and brain (2.87 μg/gtissue). Furthermore, the study detected 5-hydroxy-IMI, IMI urea and 6-chloronicotinic acid in IMI metabolites in all tissues, while IMI was detected only in the intestine and liver. Overall, the results of this study contribute to a better understanding of the metabolic behavior of IMI in organisms and provide new data to support the assessment of IMI toxicity in fish.

Background 4-Hydroxycinnamyl alcohols are a class of natural plant secondary metabolites that include p -coumaryl alcohol, caffeyl alcohol, coniferyl alcohol and sinapyl alcohol, and have physiological, ecological and biomedical significance. While it is necessary to investigate the biological pathways and economic value of these alcohols, research is hindered because of their limited availability and high cost. Traditionally, these alcohols are obtained by chemical synthesis and plant extraction. However, synthesis by biotransformation with immobilized microorganisms is of great interest because it is environmentally friendly and offers high stability and regenerable cofactors. Therefore, we produced 4-hydroxycinnamyl alcohols using immobilized whole cells of engineered Escherichia coli as the biocatalyst. Results In this study, we used the recombinant E. coli strain, M15–4CL1–CCR, expressing the fusion protein 4-coumaric acid: coenzyme A ligase and the cinnamoyl coenzyme A reductase and a recombinant E. coli strain, M15–CAD, expressing cinnamyl alcohol dehydrogenase from Populus tomentosa ( P. tomentosa ). High performance liquid chromatography and mass spectrometry showed that the immobilized whole cells of the two recombinant E. coli strains could effectively convert the phenylpropanoic acids to their corresponding 4-hydroxycinnamyl alcohols. Further, the optimum buffer pH and the reaction temperature were pH 7.0 and 30 °C. Under these conditions, the molar yield of the p -coumaryl alcohol, the caffeyl alcohol and the coniferyl alcohol was around 58, 24 and 60%, respectively. Moreover, the highly sensitive and selective HPLC–PDA–ESI–MSn method used in this study could be applied to the identification and quantification of these aromatic polymers. Conclusions We have developed a dual-cell immobilization system for the production of 4 - hydroxycinnamyl alcohols from inexpensive phenylpropanoic acids. This biotransformation method is both simple and environmental-friendly, which is promising for the practical and cost effective synthesis of natural products. Graphical abstract Biotransformation process of phenylpropanoic acids by immobilized whole-cells

Fritillaria (Beimu in Chinese) is a well-known traditional Chinese medicinal herbal and valuable health food, which has attracted more and more attention. In this study, an efficient method was developed to determine pyraclostrobin, fluxapyroxad, difenoconazole, and azoxystrobin in plants, fresh Fritillaria , dry Fritillaria , and soil via liquid chromatography-tandem mass spectrometry. The average recoveries of the method were 78.9–109.7% with relative standard deviations of 0.94–11.1%. The dissipation half-lives of the four fungicides were 4.4–7.7 days in the Fritillaria plant and 11.6–18.2 days in the soil. The terminal residues of four fungicides were 0.033–0.13 mg/kg in fresh Fritillaria , 0.096–0.42 mg/kg in dry Fritillaria , and 0.12–0.74 mg/kg in soil. In the risk assessment of dietary exposure, all the chronic hazard quotient and acute hazard quotient index values were far below 100%, which were both acceptable to consumers. Accordingly, 7 days was recommended as the pre-harvest interval for the four fungicides in Fritillaria . This work could guide the safe use of these fungicides in Fritillaria and also give a reference for the Chinese government to establish the maximum residue limits (MRLs).

Cyclaniliprole, a novel diamide insecticide, can successfully control Spodoptera litura (Fabricius, 1775) in cabbage. Understanding the residual level of cyclaniliprole in crops and the risk related to its dietary intake is imperative for safe application. Here, we established a simplified, sensitive method for simultaneous analysis of cyclaniliprole and its metabolite NK-1375 (3-bromo-2-((2-bromo-4 H -pyrazolo[1,5-d]pyrido[3,2-b]-[1,4]oxazin-4-ylidene)amino)-5-chloro- N -(1-cyclopropylethyl)benzamide) in cabbage by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate their dissipation behavior and residual characteristics. Cyclaniliprole showed rapid dissipation in cabbage and had a half-life of 1.8–2.7 days. The highest residue of total cyclaniliprole (sum of cyclaniliprole and NK-1375) in cabbage from different pre-harvest intervals (3 and 5 days) was 0.25 mg/kg. Our results confirmed the generally low dietary risk quotient of cyclaniliprole (0.243–1.036%) among different age and gender groups in China. Therefore, cyclaniliprole did not pose an unacceptable risk to consumers. This study contributes to setting cyclaniliprole maximum residue limit in cabbage by assessing its dissipation fate and food safety risks.

This study adopts an interdisciplinary approach encompassing historical geography, religious sociology, and digital humanities, concentrating on the Great Tea Road (GTR) and Guan Yu Cult Sites (GYCS) within a 400 km radius of Hankou. It investigates their interaction mechanisms through three dimensions: the agglomeration of GYCS, the influence of GYCS within the GTR network, and the significance of nodes in the dissemination of belief. The integrated analysis of GIS and Gephi indicates that the spatial distribution of GYCS is closely linked to dynamic GTR, exhibiting considerable regional variation, while its cross-regional dissemination mostly relies on social network-mediated practical flexibility. This study establishes a quantitative framework for studying belief dissemination through cultural route dynamics, addresses deficiencies in the interaction between material and intangible aspects within global cultural route theory, and facilitates the application of world heritage and integrated protection.

Background 4-Hydroxycinnamaldehydes are important intermediates in several secondary metabolism pathways, including those involved in the biosynthesis of phenolic acids, flavonoids, terpenoids and monolignols. They are also involved in the biosynthesis and degradation of lignins, which are important limiting factors during the processes of papermaking and biofuel production. Access to these aromatic polymers is necessary to explore the secondary biometabolic pathways they are involved in. Coniferaldehyde, sinapaldehyde, p -coumaraldehyde and caffealdehyde are members of the 4-hydroxycinnamaldehyde family. Although coniferaldehyde and sinapaldehyde can be purchased from commercial sources, p -coumaraldehyde and caffealdehyde are not commercially available. Therefore, there is increasing interest in producing 4-hydroxycinnamaldehydes. Here, we attempted to produce 4-hydroxycinnamaldehydes using engineered Escherichia coli . Results 4-Coumaric acid: coenzyme A ligase (4CL1) and cinnamoyl coenzyme A reductase (CCR) were fused by means of genetic engineering to generate an artificial bifunctional enzyme, 4CL1–CCR, which was overexpressed in cultured E. coli supplemented with phenylpropanoic acids. Three 4-hydroxycinnamaldehydes, p -coumaraldehyde, caffealdehyde and coniferaldehyde, were thereby biosynthesized and secreted into the culture medium. The products were extracted and purified from the culture medium, and identically characterized by the HPLC–PDA–ESI–MSn. The productivity of this new metabolic system were 49 mg/L for p -coumaraldehyde, 19 mg/L for caffealdehyde and 35 mg/L for coniferaldehyde. Extracellular hydroxycinnamoyl-coenzyme A thioesters were not detected, indicating that these thioesters could not pass freely through the cellular membrane. The fusion enzyme 4CL1–CCR can catalyze sequential multistep reactions, thereby avoiding the permeability problem of intermediates, which reveals its superiority over a mixture of individual native enzymes. Moreover, we have described a highly sensitive and selective method for separation and identification of phenylpropanoic acids and their corresponding cinnamaldehydes in the present paper. The feasibility of this method has been proven in the application of the method to the analysis of the metabolites of whole-cell catalysts. Conclusions We have established a bioconversion pathway for the microbial production of valuable 4-hydroxycinnamaldehydes from phenylpropanoic acids. This biotransformation method is both convenient and environmentally friendly, and provides new insights into the biosynthesis of natural plant secondary products.

青头潜鸭 (Aythya baeri) 是近年来受到国际广泛关注的极危物种, 全球种群数量不足1000只, 中国作为其主要分布地, 种群数量约为600—800只。松嫩平原是其历史繁殖地, 而扎龙保护区是松嫩平原较有代表性且受到国际广泛关注的大面积湿地, 其内青头潜鸭的分布状况对其研究与保护有重要意义。本文综合野外实地观察及文献, 对青头潜鸭在扎龙保护区的分布状况进行了总结, 认为目前青头潜鸭在扎龙保护区的分布地主要在保护区的东北部、西北部及东南部。

青头潜鸭（Aythya baeri）是近年来受到国际广泛关注的极危物种，全球种群数量不足1000只，中国作为其主要分布地，种群数量约为600—800只。松嫩平原是其历史繁殖地，而扎龙保护区是松嫩平原较有代表性且受到国际广泛关注的大面积湿地，其内青头潜鸭的分布状况对其研究与保护有重要意义。本文综合野外实地观察及文献，对青头潜鸭在扎龙保护区的分布状况进行了总结，认为目前青头潜鸭在扎龙保护区的分布地主要在保护区的东北部、西北部及东南部。