ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

ObjectiveTo investigate the effects of different fermentation methods and times on the fungal flora and chemical composition of Aurantii Fructus， in order to obtain the optimal fermentation conditions and flora structure， and to ensure the stability and controllability of the fermented varieties. MethodsScanning electron microscopy was used to observe and analyze the colony characteristics on the surface of Aurantii Fructus under different fermentation conditions. Internal transcribed spacer 2（ITS2） high-throughput sequencing， combined with fungal community diversity analysis and fungal community structure analysis， were used to obtain the fungal flora microbial categories of Aurantii Fructus under the conditions of traditional pressure-shelf fermentation and non-pressure-shelf natural fermentation for 7， 14， 21 d（numbered Y1-Y3 for the former， and numbered F1-F3 for the latter）， respectively. At the same time， the chemical components in the fermentation process were detected by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS）， combined with principal component analysis（PCA）， partial least squares-discriminant analysis（PLS-DA） and compound retention time， parent ions， characteristic fragment ions and other information， the differential compounds between the different fermentation samples were screened and identified. ResultsThe analysis of fungal community diversity showed that the dominant flora did not change at different fermentation time points in the traditional pressure-shelf fermentation method， while in the non-pressure-shelf natural fermentation method， there was a significant difference with the fermentation process， and at the genus level， the dominant genus of samples Y1， Y2， Y3 and F2 was Aspergillus， while the dominant genera of samples F1 and F3 were both Rhizopus. This indicated that the microbial growth environment provided by the traditional fermentation method was more stable， and the microbial community structure was more stable， which was more conducive to the stable and controllable fermentation process and fermented products. A total of 155 compounds were identified by compositional analysis， including 70 flavonoids， 38 coumarins， 10 alkaloids， 34 organic acids and 3 other compounds. After fermentation， two new components of ribalinine and pranferin were produced. Different fermentation conditions also brought about differences in chemical composition， multivariate statistical analysis obtained 26 differential compounds under two different fermentation methods， mainly including flavonoids， organic acids and coumarins. Comprehensively， the microbial community structure of samples fermented by the traditional pressure-shelf method of Aurantii Fructus for 14 d was stable， the species richness was high and the overall content of differential compounds was high， which was the optimal processing condition. ConclusionCompared with non-pressure-shelf natural fermentation， the traditional method has obvious advantages in terms of the stability of the microbial community structure and the content of chemical compounds， and the optimal condition is 14 days of fermentation. This study is helpful to promote the quality stability and fermentation bioavailability of fermented products of Aurantii Fructus， as well as to provide an experimental basis for the further improvement of the quality control methods of this variety.

ObjectiveTo investigate the effects of different fermentation methods and times on the fungal flora and chemical composition of Aurantii Fructus， in order to obtain the optimal fermentation conditions and flora structure， and to ensure the stability and controllability of the fermented varieties. MethodsScanning electron microscopy was used to observe and analyze the colony characteristics on the surface of Aurantii Fructus under different fermentation conditions. Internal transcribed spacer 2（ITS2） high-throughput sequencing， combined with fungal community diversity analysis and fungal community structure analysis， were used to obtain the fungal flora microbial categories of Aurantii Fructus under the conditions of traditional pressure-shelf fermentation and non-pressure-shelf natural fermentation for 7， 14， 21 d（numbered Y1-Y3 for the former， and numbered F1-F3 for the latter）， respectively. At the same time， the chemical components in the fermentation process were detected by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS/MS）， combined with principal component analysis（PCA）， partial least squares-discriminant analysis（PLS-DA） and compound retention time， parent ions， characteristic fragment ions and other information， the differential compounds between the different fermentation samples were screened and identified. ResultsThe analysis of fungal community diversity showed that the dominant flora did not change at different fermentation time points in the traditional pressure-shelf fermentation method， while in the non-pressure-shelf natural fermentation method， there was a significant difference with the fermentation process， and at the genus level， the dominant genus of samples Y1， Y2， Y3 and F2 was Aspergillus， while the dominant genera of samples F1 and F3 were both Rhizopus. This indicated that the microbial growth environment provided by the traditional fermentation method was more stable， and the microbial community structure was more stable， which was more conducive to the stable and controllable fermentation process and fermented products. A total of 155 compounds were identified by compositional analysis， including 70 flavonoids， 38 coumarins， 10 alkaloids， 34 organic acids and 3 other compounds. After fermentation， two new components of ribalinine and pranferin were produced. Different fermentation conditions also brought about differences in chemical composition， multivariate statistical analysis obtained 26 differential compounds under two different fermentation methods， mainly including flavonoids， organic acids and coumarins. Comprehensively， the microbial community structure of samples fermented by the traditional pressure-shelf method of Aurantii Fructus for 14 d was stable， the species richness was high and the overall content of differential compounds was high， which was the optimal processing condition. ConclusionCompared with non-pressure-shelf natural fermentation， the traditional method has obvious advantages in terms of the stability of the microbial community structure and the content of chemical compounds， and the optimal condition is 14 days of fermentation. This study is helpful to promote the quality stability and fermentation bioavailability of fermented products of Aurantii Fructus， as well as to provide an experimental basis for the further improvement of the quality control methods of this variety.

Objective To analyze the monitoring status of occupational hazard factors in key industry workplaces in a city of the Pearl River Delta area from 2019 to 2023. Methods A total of 1 548 enterprises in 12 key industries of the city were selected as the research subjects using the judgmental sampling method. Their monitoring data for dust, chemical factors, and noise, along with the occupational health management status of the enterprises were analyzed. Results Among the 1 548 enterprises, large and medium-sized enterprises accounted for 2.7% and 13.4%, while small and micro enterprises accounted for 83.9%. A total of 474 enterprises exceeded the national limit in the detection of occupational hazard factors, with an exceedance rate of 30.6%. The rates of workers exposed to occupational hazard factors, dust, chemical factors, and noise were 29.4%, 6.9%, 21.0%, and 13.0%, respectively, all showing a downward trend year by year (all P<0.05). The training rates for occupational health among enterprise managers, responsible persons, and workers were 84.1%, 84.2%, and 91.2%, respectively. The detection rates for abnormal occupational health examinations among workers exposed to dust, chemical factors, and noise were 0.2%, 0.3%, and 0.5%, respectively. The setting rates of warning signs and warning instructions among enterprises for dust, chemical toxins, and noise were 87.3%, 91.1%, and 89.5%, respectively. The setting rates for dust, toxic chemical, and noise control facilities were 72.4%, 75.4%, and 46.0%, with effectiveness rates of 70.5%, 56.6%, and 55.2%, respectively. The distribution rates of personal protective dust masks, gas masks, and noise earplugs/earmuffs were 91.9%, 83.8%, and 86.4%, with wearing rates of 80.8%, 70.5%, and 76.4%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the work site of occupational hazard factors were15.2%, 1.0%, and 21.6%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the workplace of occupational hazard factors were 2.4%, 2.5%, and 12.3%, respectively. The exceedance rate for noise in work site showed an upward trend year by year (P<0.01). Conclusion Occupational disease prevention and control work in the key industries of this city needs strengthening. It is essential to further enhance the regular monitoring and preventive measures of occupational hazard factors in enterprises, improve protective measures, strengthen the use of personal protective equipment, and enhance occupational health training and supervision, to effectively reduce the risk of occupational diseases and protect workers' occupational health rights.

Background/Aims: Dexamethasone (DEX) is a widely used exogenous therapeutic glucocorticoid in clinical settings. Its long-term use leads to many side effects. However, its effect on metabolic disorders in individuals on a high-fat diet (HFD) remains poorly understood. Methods: In this study, HFD-fed mice were intraperitoneally injected with DEX 2.5 mg/kg/day for 30 days. Lipid metabolism, adipocyte proliferation, and inflammation were assayed using typical approaches. Results: DEX increased the epididymal fat index and epididymal adipocyte size in HFD-fed mice. The number of epididymal adipocytes with diameters > 70 μm accounted for 0.5% of the cells in the control group, 30% of the cells in the DEX group, 19% of the cells in the HFD group, and 38% of all the cells in the D+H group. Adipocyte proliferation in the D+H group was inhibited by DEX treatment. Adipocyte enlargement in the D+H group was associated with increased the lipid accumulation but not the adipocyte proliferation. In contrast, the liver triglyceride and total cholesterol levels and their metabolism were downregulated by the same treatment, indicating the therapeutic potential of DEX for nonalcoholic fatty liver disease. Conclusions DEX synergizes with HFD to promote lipid deposition in adipose tissues. A high risk of obesity development in patients receiving HFD and DEX treatment is suggested.

Background/Aims: Dexamethasone (DEX) is a widely used exogenous therapeutic glucocorticoid in clinical settings. Its long-term use leads to many side effects. However, its effect on metabolic disorders in individuals on a high-fat diet (HFD) remains poorly understood. Methods: In this study, HFD-fed mice were intraperitoneally injected with DEX 2.5 mg/kg/day for 30 days. Lipid metabolism, adipocyte proliferation, and inflammation were assayed using typical approaches. Results: DEX increased the epididymal fat index and epididymal adipocyte size in HFD-fed mice. The number of epididymal adipocytes with diameters > 70 μm accounted for 0.5% of the cells in the control group, 30% of the cells in the DEX group, 19% of the cells in the HFD group, and 38% of all the cells in the D+H group. Adipocyte proliferation in the D+H group was inhibited by DEX treatment. Adipocyte enlargement in the D+H group was associated with increased the lipid accumulation but not the adipocyte proliferation. In contrast, the liver triglyceride and total cholesterol levels and their metabolism were downregulated by the same treatment, indicating the therapeutic potential of DEX for nonalcoholic fatty liver disease. Conclusions DEX synergizes with HFD to promote lipid deposition in adipose tissues. A high risk of obesity development in patients receiving HFD and DEX treatment is suggested.

Background/Aims: Dexamethasone (DEX) is a widely used exogenous therapeutic glucocorticoid in clinical settings. Its long-term use leads to many side effects. However, its effect on metabolic disorders in individuals on a high-fat diet (HFD) remains poorly understood. Methods: In this study, HFD-fed mice were intraperitoneally injected with DEX 2.5 mg/kg/day for 30 days. Lipid metabolism, adipocyte proliferation, and inflammation were assayed using typical approaches. Results: DEX increased the epididymal fat index and epididymal adipocyte size in HFD-fed mice. The number of epididymal adipocytes with diameters > 70 μm accounted for 0.5% of the cells in the control group, 30% of the cells in the DEX group, 19% of the cells in the HFD group, and 38% of all the cells in the D+H group. Adipocyte proliferation in the D+H group was inhibited by DEX treatment. Adipocyte enlargement in the D+H group was associated with increased the lipid accumulation but not the adipocyte proliferation. In contrast, the liver triglyceride and total cholesterol levels and their metabolism were downregulated by the same treatment, indicating the therapeutic potential of DEX for nonalcoholic fatty liver disease. Conclusions DEX synergizes with HFD to promote lipid deposition in adipose tissues. A high risk of obesity development in patients receiving HFD and DEX treatment is suggested.

ObjectiveTo screen and evaluate the antidepressant compounds of Curcumae Rhizoma， and explore its mechanism of regulating the nuclear factor erythroid 2-related factor 2（Nrf2）/glutathione（GSH） peroxidase 4（GPX4）/GSH pathway from an antioxidant perspective. MethodsThe antioxidant activities in vitro of 11 characteristic components from Curcumae Rhizoma， including curcumol， curgerenone， curdione， curzerene， curcumenol， curcumenone， dehydrocurdione， isocurcumenol， furanodienone， furanodiene and zederone， were detected using 1，1-diphenyl-2-picrylhydrazyl（DPPH） and 2，2'-azinobis-（3-ethylbenzothiazoline-6-sulphonic acid） diammonium salt（ABTS） radical scavenging assays. The depression in Drosophila melanogaster was induced by chronic unpredictable mild stress（CUMS）， and W1118 wild-type male D. melanogaster were randomly divided into blank group， model group， curcumol group， curgerenone group， curdione group， curzerene group， curcumenol group，curcumenone group， dehydrocurdione group， isocurcumenol group， furanodienone group， furanodiene group， zederone group and fluoxetine group（10 μmol·L^-1）. The treatment groups received a dose of 0.1 g·L^-1 of 11 characteristic components from Curcumae Rhizoma， while the blank and model groups were administered equivalent volumes of solvent. The sucrose preference test， climbing test and forced swimming test were used to evaluate the behavioral indicators of depression in D. melanogaster. Liquid chromatography-mass spectrometry（LC-MS） was used to detect the levels of 5-hydroxytryptamine（5-HT） and dopamine（DA） in the brain of D. melanogaster， and the entropy weight method was used to comprehensively evaluate neurobehavioral and neurotransmitter indicators， resulting in the identification of the antidepressant active components of Curcumae Rhizoma. In addition， a mouse depression model was established by CUMS， and C57BL/6J mice were randomly divided into blank group， model group， low and high dose groups of curzerene（0.5， 1 mg·kg^-1）， and fluoxetine group（10 mg·kg^-1） to confirm the antidepressant effect of the optimal active ingredient by behavioral analysis. Flow cytometry was used to detect the content of reactive oxygen species（ROS） in the hippocampus of mice from each group. Enzyme-linked immunosorbent assay was used to detect the contents of adenosine triphosphate（ATP）， superoxide dismutase（SOD）， catalase（CAT） and GSH. Transmission electron microscope（TEM） was used to observe the effect of curzerene on the ultrastructure of mitochondria in hippocampal tissue. Western blot was performed to determine the level of Nrf2 protein， and Nrf2 inhibitor（ML385） was used to verify the relationship between the antidepressant effect of curzerene and regulation of Nrf2. Real time fluorescence quantitative polymerase chain reaction（Real-time PCR） was employed to detect the effect of curzerene on the mRNA expression level of GPX. ResultsIn vitro antioxidant experiments showed that curzerene and curgerenone exhibited the most significant ability to scavenge free radicals， and comprehensive evaluation results of entropy weight method indicated that curzerene stood out as the most promising active component. Compared with the blank group， the model group exhibited a significant decrease in sucrose preference coefficient and the number of times entering the open field center（P<0.01）， as well as a significant increase in immobility time in the forced swimming and tail suspension tests（P<0.01）， and the ROS content in hippocampus significantly elevated（P<0.01）， while the ATP content significantly reduced（P<0.01）. In the hippocampal neurons of the model group， mitochondrial cristae were disordered， with vacuolation of the inner membrane and severe damage. Nrf2 protein expression level in the model group was significantly decreased（P<0.05）， and the antioxidant enzymes SOD， CAT and GSH contents were also significantly reduced（P<0.05， P<0.01）， and the gene expression levels of GPX1， GPX4 and GPX7 were significantly decreased（P<0.01）. Compared with the model group， the high-dose group of curzerene showed a significant increase in the sucrose preference coefficient and the number of times entering the open field center（P<0.05）， as well as a significant decrease in immobility time in the forced swimming and tail suspension tests（P<0.05， P<0.01）. The ROS content in the hippocampus of the high-dose group of curzerene was significantly reduced（P<0.01）， while the ATP content was significantly increased（P<0.05）. The neuronal mitochondrial damage in the hippocampus of the high-dose group of curzerene was alleviated， and the expression level of Nrf2 protein was significantly increased（P<0.05）. The Nrf2 inhibitor ML385 reversed the improvement of curzerene on depressive behaviors in CUMS mice. The GSH content in the hippocampal neurons of the high-dose group of curzerene was significantly increased（P<0.01）， while there were no significant differences in SOD and CAT contents. The expression level of GPX4 gene in the hippocampal neurons of the high-dose group of curzerene was significantly increased（P<0.05）， while there were no significant differences in other GPX genes. ConclusionCurzerene is the best component with antidepressant activity in Curcumae Rhizoma. It may improve mitochondrial dysfunction to exert its antidepressant effect by regulating Nrf2 and its downstream GPX4/GSH pathway rather than CAT or SOD pathways.

Guided by the turbidity toxin theory， it is believed that the key pathogenesis of constipation-predominant irritable bowel syndrome is the obstruction of turbidity toxin and the disruption of intestinal function. Treatment is based on the principles of dispelling turbidity toxin and promoting intestinal function. The clinical patterns can be divided into three types， turbidity toxin heat accumulation pattern， turbidity toxin combined with liver depression and qi stagnation pattern， and turbidity toxin combined with qi and yin deficiency pattern. The treatment can respectively use self-prescribed Tongfu Jiangzhuo Formula （通腑降浊方） to clear heat and unblock the bowels， direct the turbid downward and resolve toxins； use self-prescribed Shugan Jiangzhuo Formula （疏肝降浊方） to soothe the liver and move qi， direct the turbid downward and resolve toxins； use self-prescribed Mazhi Jiangzhuo Formula （麻枳降浊方） to boost qi and nourish yin， moisten the intestines to remove turbidity and resolve toxins.

As the number of patients with compromised immune function increases and fungal resistance develops, so does the risk of contracting deadly fungi in humans. Both fungi and humans are eukaryotes, so identifying unique targets for antifungal drug development is difficult. In addition, the existing antifungal drugs are limited by toxicity, drug interaction and drug resistance in practical application, which leads to the increasing incidence and fatal rate of fungal infections. Therefore, it is urgent to develop new antifungal drugs. The semi-synthetic technology using microbial fermentation products from natural sources as lead compounds has become the most used method in structural modification of antifungal drugs due to its advantages of few reaction steps and easy operation. This paper will introduce the current status of natural antifungal drugs in clinical use, as well as the latest progress in the research and development of new semi-synthetic antifungal drugs, and summarize their mechanism of action, structural modifications, advantages and disadvantages, so as to provide reference for the subsequent development of new antifungal drugs.