1.Efficacy and safety of simultaneous resection versus staged resection for initially resectable rectal cancer with synchronous liver metastases
Zhekun HUANG ; Yang LÜ ; Songbin LIN ; Jianmin XU ; Wentao TANG
Chinese Journal of Clinical Medicine 2025;32(3):355-361
Objective To evaluate the safety and efficacy of simultaneous resection for initially resectable rectal cancer with synchronous liver metastases. Methods A retrospective analysis was conducted on 305 patients with initially resectable rectal cancer with synchronous liver metastases. These patients were diagnosed at Zhongshan Hospital, Fudan University from January 2016 to June 2020. Among them, 191 underwent simultaneous rectum and liver resection and 114 underwent staged resection. Propensity score matching (PSM) was performed at a 1∶1 ratio. Clinical data were compared and Kaplan-Meier survival curves were plotted. Results After PSM, 85 patients were included in each group. General data showed no significant differences. Except for liver metastasis resection method, no statistical differences were found in primary tumor surgery approach, intraoperative blood loss, intraoperative complications, time to first flatus and defecation, 30-day mortality, and postoperative hospital stay between the simultaneous resection group and the staged resection group. The overall complication rate was higher in the simultaneous resection group (48.2% vs 29.4%, P=0.04). Specifically, the grade Ⅱ complications were significantly higher (29.4% vs 14.1%, P=0.016), but there’s no differences in severe complications (grade Ⅲ-Ⅴ). No statistically differences were observed in median progression-free survival (HR=0.70, 95%CI 0.50-0.97, P=0.103) and 5-year overall survival (HR=0.95, 95%CI 0.63-1.44, P=0.259). Conclusions Simultaneous resection demonstrates comparable safety and efficacy to staged resection for initially resectable rectal cancer with synchronous liver metastases.
2.Prediction of Potential Regulatory Pathways Involving The Notch Signaling Pathway and Its Associated Non-coding RNAs in Alzheimer’s Disease Based on Database Analysis
Meng-Lin LÜ ; Xing-Ran LIU ; Xian-Juan KOU
Progress in Biochemistry and Biophysics 2025;52(8):1942-1957
Alzheimer’s disease (AD) is a chronic, progressive, and irreversible neurodegenerative disorder that typically begins with a subtle onset and progresses slowly. Pathologically, it is characterized by two hallmark features: the extracellular accumulation of amyloid β-protein (Aβ), forming senile plaques, and the intracellular hyperphosphorylation of tau protein, resulting in neurofibrillary tangles (NFTs). These pathological changes are accompanied by substantial neuronal and synaptic loss, particularly in critical brain regions such as the cerebral cortex and hippocampus. Clinically, AD presents as a gradual decline in memory, language abilities, and spatial orientation, significantly impairing the quality of life of affected individuals. With the aging population steadily increasing in China, the incidence of AD is rising, making it a major public health concern that requires urgent attention. The growing societal and economic burden of AD underscores the pressing need to identify effective diagnostic biomarkers and develop novel therapeutic strategies. Among the various molecular signaling pathways involved in neurological disorders, the Notch signaling pathway is especially noteworthy due to its evolutionary conservation and regulatory roles in cell proliferation, differentiation, development, and apoptosis. In the central nervous system, Notch signaling is essential for neurodevelopment and synaptic plasticity and has been implicated in several neurodegenerative processes. Although some studies suggest that Notch signaling may influence AD-related pathology, its precise role in AD remains poorly understood. In particular, the interaction between Notch signaling and non-coding RNAs (ncRNAs)—key regulators of gene expression—has received limited attention. NcRNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are known to exert extensive regulatory functions at both transcriptional and post-transcriptional levels. Dysregulation of these molecules has been widely associated with various diseases, including cancers, cardiovascular conditions, and neurodegenerative disorders. Notably, interactions between ncRNAs and major signaling pathways such as Notch can produce widespread biological effects. While such interactions have been increasingly reported in several disease models, comprehensive studies investigating the regulatory relationship between Notch signaling and ncRNAs in the context of AD remain scarce. Given the capacity of ncRNAs to modulate signaling cascades and form complex regulatory networks, a deeper understanding of their crosstalk with the Notch pathway could provide novel insights into AD pathogenesis and reveal potential targets for diagnosis and treatment. In this study, we investigated the regulatory landscape involving the Notch signaling pathway and associated ncRNAs in AD using bioinformatics approaches. By integrating data from multiple public databases, we systematically identified significantly dysregulated Notch pathway-related genes and their interacting ncRNAs in AD. Based on this analysis, we constructed a lncRNA-miRNA-mRNA regulatory network to elucidate the potential mechanisms linking Notch signaling to ncRNA-mediated gene regulation in AD pathogenesis. Furthermore, we explored the internal relationships and molecular mechanisms within this network and assessed the feasibility and clinical relevance of these molecules as early diagnostic biomarkers and potential therapeutic targets for AD. This study aims to deepen our understanding of the molecular basis of AD and offer novel strategies for its diagnosis and treatment.
3.The Role of Skeletal Muscle Satellite Cells-mediated Muscle Regeneration in The Treatment of Age-related Sarcopenia
Wei-Xiu JI ; Jia-Lin LÜ ; Yi-Fan MA ; Yun-Gang ZHAO
Progress in Biochemistry and Biophysics 2025;52(8):2033-2050
Age-related sarcopenia is a progressive, systemic skeletal muscle disorder associated with aging. It is primarily characterized by a significant decline in muscle mass, strength, and physical function, rather than being an inevitable consequence of normal aging. Despite ongoing research, there is still no globally unified consensus among physicians regarding the diagnostic criteria and clinical indicators of this condition. Nonetheless, regardless of the diagnostic standards applied, the prevalence of age-related sarcopenia remains alarmingly high. With the global population aging at an accelerating rate, its incidence is expected to rise further, posing a significant public health challenge. Age-related sarcopenia not only markedly increases the risk of physical disability but also profoundly affects patients’ quality of life, independence, and overall survival. As such, the development of effective prevention and treatment strategies to mitigate its dual burden on both societal and individual health has become an urgent and critical priority. Skeletal muscle regeneration, a vital physiological process for maintaining muscle health, is significantly impaired in age-related sarcopenia and is considered one of its primary underlying causes. Skeletal muscle satellite cells (MSCs), also known as muscle stem cells, play a pivotal role in generating new muscle fibers and maintaining muscle mass and function. A decline in both the number and functionality of MSCs is closely linked to the onset and progression of sarcopenia. This dysfunction is driven by alterations in intrinsic MSC mechanisms—such as Notch, Wnt/β‑Catenin, and mTOR signaling pathways—as well as changes in transcription factors and epigenetic modifications. Additionally, the MSC microenvironment, including both the direct niche formed by skeletal muscle fibers and their secreted cytokines, and the indirect niche composed of extracellular matrix proteins and various cell types, undergoes age-related changes. Mitochondrial dysfunction and chronic inflammation further contribute to MSC impairment, ultimately leading to the development of sarcopenia. Currently, there are no approved pharmacological treatments for age-related sarcopenia. Nutritional intervention and exercise remain the cornerstone of therapeutic strategies. Adequate protein intake, coupled with sufficient energy provision, is fundamental to both the prevention and treatment of this condition. Adjuvant therapies, such as dietary supplements and caloric restriction, offer additional therapeutic potential. Exercise promotes muscle regeneration and ameliorates sarcopenia by acting on MSCs through various mechanisms, including mechanical stress, myokine secretion, distant cytokine signaling, immune modulation, and epigenetic regulation. When combined with a structured exercise regimen, adequate protein intake has been shown to be particularly effective in preventing age-related sarcopenia. However, traditional interventions may be inadequate for patients with limited mobility, poor overall health, or advanced sarcopenia. Emerging therapeutic strategies—such as miRNA mimics or inhibitors, gut microbiota transplantation, and stem cell therapy—present promising new directions for MSC-based interventions. This review comprehensively examines recent advances in MSC-mediated muscle regeneration in age-related sarcopenia and systematically discusses therapeutic strategies targeting MSC regulation to enhance muscle mass and strength. The goal is to provide a theoretical foundation and identify future research directions for the prevention and treatment of this increasingly prevalent condition.
4.Epidemiological characteristics of dengue fever in Shenzhen City in 2024
Jia WAN ; Cong NIU ; Wei LIU ; Liangqiang LIN ; Fan YANG ; Ziquan LÜ ; Zhen ZHANG ; Tiejian FENG ; Jianhua LU ; Dongfeng KONG
Chinese Journal of Schistosomiasis Control 2025;37(5):517-523
Objective To investigate the epidemiological characteristics of dengue fever in Shenzhen City in 2024, so as to provide insights into formulation of the preventive and control measures for dengue fever. Methods The epidemiological data of dengue cases reported in Shenzhen City in 2024 were extracted from the China Disease Prevention and Control Information System and field epidemiological survey data of dengue fever in Shenzhen City, and the temporal, regional and population distributions of dengue fever cases, source of acquire dengue virus infections, disease diagnosis and treatment and outbreaks were analyzed. The dengue virus nucleic acid was tested and the serotypes of dengue virus were characterized using real-time quantitative reverse transcription PCR (RT-qPCR) assay, and the dengue virus gene was sequenced using next-generation sequencing (NGS). In addition, the surveillance on the density of Aedes albopictus was performed using Breteau index (BI) and mosquito oviposition index (MOI). Results A total of 1 735 dengue fever cases were reported in Shenzhen City in 2024, including 952 local cases and 783 imported cases. Most imported dengue fever cases acquired infections from eight cities of Foshan, Guangzhou, Zhongshan, Jiangmen, Dongguan, Zhaoqing, Huizhou, and Zhuhai in the Pearl River Delta region (664 cases, 84.8% of total imported cases) into Baoan, Longgang, and Nanshan districts. The epidemic exhibited an early onset and rapid progression, peaking during the period between September and November (1 632 cases, 94.1% of total cases), and dengue fever cases were distributed across 73 subdistricts in 10 districts, with most cases reported in densely populated central and western regions. The dengue fever cases had a male-to-female ratio of 1.9∶1.0, and a median age of 37 (21) years, with a higher median age among local cases than among imported cases [40 (20) years vs. 33(15) years; Z = -10.30, P < 0.05]. Housework, unemployment, workers, and business service were predominant occupations (1 405 cases, 81.0% of total cases), and there was a significant difference in the constituent ratio of occupations between local and imported cases (χ2 = 92.30, P < 0.05). Among the 1 735 dengue fever cases, the median duration from onset to definitive diagnosis was 3.3 (2.9) days, and 1 686 cases (97.2%) were identified in healthcare facilities, with a low rate of hospitalization and isolation seen in 1 701 inpatients with available epidemiological data (485 cases, 28.5% of total inpatients). A total of 29 outbreaks of dengue fever occurred in Shenzhen City across 2024, which primarily in construction sites (27 outbreaks, 93.1% of total). Dengue virus type I was the dominant serotype causing dengue fever in Shenzhen City in 2024. Sequencing showed that the genomes of dengue virus from multiple dengue fever cases in Shenzhen City shared a high sequence homology with those from cities neighboring Shenzhen City, and there might be intra-city transmission of dengue virus among multiple construction sites in Shenzhen City. The Aedes albopictus density was significantly higher in Shenzhen City in 2024 than in 2023, peaking from May to September. The annual MOI values ranged from 0.9 to 14.0, and the BI values ranged from 0.6 to 6.0. Conclusions The overall epidemic of dengue fever was severe in Shenzhen City in 2024, which was greatly affected by case importation from neighboring cities, construction sites-centered local transmission, and the effectives of routine mosquito vector control was not satisfactory. Integrated dengue fever control measures should be implemented, focusing on regional joint prevention and control mechanisms, capacity building for mosquito vector control, addressing challenges in epidemic containment at construction sites, and strengthening case detection and management systems.
5.Antagonistic effect of Lactobacillus reuteri on testicular reproductive toxicity of neonicotinoid insecticides in mice.
Zhen-Han XU ; Pei-Gen CHEN ; Jin-Tao GUO ; Lin-Yan LÜ ; Hai-Cheng CHEN ; Gui-Hua LIU
National Journal of Andrology 2025;31(2):131-137
OBJECTIVE:
To explore the effect of Lactobacillus reuteri on testicular injury in mice exposed to neonicotinoid insecticides (NNI).
METHODS:
Fifteen C57BL/6 male mice were randomly divided into control group (CTRL group), exposure group (NNI group) and Lactobacillus intervention group (NNI-L group). The mice in CTRL group were given 0.02ml/g of 0.5% carboxymethyl cellulose sodium solution by gavage for 14 days. The mice in NNI group were given 0.02 ml/g of NNI mixture by gavage for 14 days. The mice in NNI-L group were given 0.02 ml/g of NNI mixture by gavage and 5×108cfu/ml of Lactobacillus reuteri powder solution for 14 days. Then, the histomorphology and function of testicle were evaluated by hematoxylin-eosin staining, immunofluorescence staining and RNA sequencing.
RESULTS:
Compared with CTRL group, the thickness of testicular seminiferous epithelium in the NNI group was significantly thinner. And the decline in the number of spermatogenic cells and sperm was observed. And the expression of spermatogonial stem cell marker UCHL1 was down-regulated which was significantly improved in NNI-L group compared with the NNI group. The abnormal expressions of hormone and sperm methylation related genes in testis of NNI group were detected by RNA sequencing, with significant down-regulation being found in NPFF and IGF2. While the expression of HSD3B8 was significantly up-regulated. The abnormal expression of these genes could be significantly improved after oral administration of Lactobacillus reuteri.
CONCLUSION
Testicular spermatogenesis and endocrine function can be damaged by NNI exposure. And oral administration of Lactobacillus reuteri protects testis from the adverse effects of NNI toxicity.
Animals
;
Male
;
Limosilactobacillus reuteri
;
Testis/pathology*
;
Mice
;
Mice, Inbred C57BL
;
Insecticides/toxicity*
;
Neonicotinoids/toxicity*
;
Probiotics
;
Spermatogenesis/drug effects*
6.Rapid Analysis of Cyanide Based on a Ratiometric Fluorescent Probe Using Gold Nanoclusters-Fluorescein
Tai-Shen HE ; Zhong-Jiang LÜ ; Yi-Ming SUN ; Yu-Yang LI ; Yi YE ; Yao LIN ; Lin-Chuan LIAO
Journal of Forensic Medicine 2025;41(4):340-347
Objective To establish a rapid analysis method for cyanide based on a ratiometric fluores-cent probe,providing a quantitative strategy for on-site visual and rapid detection of cyanide.Methods A dual-emission ratiometric fluorescent probe(AuNCs-FL)was constructed by using bovine serum al-bumin(BSA)-stabilized gold nanoclusters(AuNCs,fluorescence emission at 660 nm)as the responsive signal unit and fluorescein(FL,emission at 515 nm)as the internal reference.Results The etching effect of cyanide on AuNCs resulted in fluorescence quenching at 660 nm,while the fluorescence inten-sity of FL at 515 nm remained unchanged,enabling a rapid response analysis of cyanide shift from red to green fluorescence.The developed probe enabled rapid analysis of cyanide within 3 min,with a limit of detection(LOD)of 3.4 mg/L and a visual detection range of 10-100 mg/L.Conclusion The AuNCs-FL fluorescent probe is structurally simple,low-cost,and easy to operate,delivering rapid and accurate results.It also avoids the interference from sulfides encountered in commercial cyanide test kits,making it suitable for the on-site rapid detection of suspected powder samples in cyanide poisoning cases.
7.PERK-mediated inhibition of endoplasmic reticulum stress in lipopolysaccharide-induced inflammatory responses in microglia
Jia-Xin DING ; Meng-Jun LÜ ; Lin-Xia LU ; Ci-Li JIFU ; Jun XIA ; Jing-Tao WANG
Acta Anatomica Sinica 2025;56(4):421-430
Objective To explore the role of the protein kinase R-like endoplasmic reticulum kinase(PERK)-mediated endoplasmic reticulum stress pathway in a model of lipopolysaccharide(LPS)-induced microglia inflammation.Methods To investigate its effects on endoplasmic reticulum(ER)stress,an inflammation model of microglia was established by stimulating with LPS at gradient concentrations for 24 hours and with 1 mg/L LPS for different durations.Cell viability was assessed by the CCK-8 assay;The mRNA and protein expression levels of related inflammatory factors were measured by Real-time PCR and ELISA kits.Cellular oxidative stress was evaluated by detecting reactive oxygen species(ROS),and Real-time PCR and Western blotting were used to examine the mRNA and protein expression levels of ER stress pathway markers associated with inflammation.Results 1.The effects of different concentrations of LPS on cell viability and morphology were not statistically significant after acting on BV-2 cells for 24 hours(P>0.05);2.1 mg/L LPS incubated with BV-2 cells for different times and the cell viability decreased with the increase of time;3.Compared with the 0 hour group,the levels of pro-inflammatory cytokine interleukin(IL)-1β,tumor necrosis factor-α(TNF-α)mRNA and protein expression increased significantly(P<0.05)in the LPS-stimulated 9 hours,12 hours,and 24 hours groups,and the inflammation model was successfully established;4.Compared with the 0 hour group,the protein and mRNA expression levels of the endoplasmic reticulum stress pathway-related indexes in the LPS-stimulated 9 hours,12 hours,and 24 hours groups increased significantly(P<0.01),which showed the time-dependence;5.After adding the PERK inhibitor GSK2606414,the mRNA and protein expression levels of endoplasmic reticulum stress-related indicators in the PERK inhibitor group were significantly reduced compared with those in the LPS group(P<0.05);6.The mRNA and protein expression levels of pro-inflammatory cytokines and the fluorescence intensity of ROS in the PERK inhibitor group were significantly reduced compared with those in the LPS group(P<0.01).Conclusion Targeting PERK-mediated endoplasmic reticulum stress inhibits LPS-induced inflammatory responses in microglia.
8.Evaluation of radiation-induced intestinal injury via a new human intestinal organ-on-a-chip model
Liang HU ; Lin LÜ ; Xuan TANG ; Sihan WANG ; Zuyin YU ; Yanhua LI
Military Medical Sciences 2025;49(3):171-177
Objective To establish a human intestinal organ-on-a-chip model using a multi-array chip array to simulate the microphysiological structure of the human intestine and to investigate the impact of ionizing radiation on radiation-induced damage to human intestinal cells.Methods Caco-2 and human umbilical vein endothelial cells(HUVECs)were co-cultured in an organ chip.The cells were subjected to fluid shear stress via a precision shaker.After 7 days of dynamic culture,the morphological structure of intestinal epithelial cells and venous endothelial cells within the intestinal organ chip was examined using phase contrast microscopy,immunofluorescence staining,and confocal microscopy for three-dimensional(3D)imaging.γ-H2AX and TUNEL immunofluorescence staining were employed to assess DNA damage and apoptosis in intestinal epithelial cells two days post-irradiation.Villin immunofluorescence staining was used to evaluate villus height three days post-irradiation.EdU incorporation assay and Ki67 immunofluorescence staining were conducted to observe the effects of ionizing radiation on the proliferation of intestinal epithelial cells.Results After 7 days of dynamic culture,phase contrast microscopy and immunofluorescence staining combined with confocal 3D imaging revealed that the upper intestinal epithelial cells in the middle compartment of the chip formed a 3D intestinal villus structure,while the vascular endothelial cells in the lower compartment developed a vascular network structure.The chip was subsequently irradiated by 10 Gy X-ray.Immunofluorescence staining results indicated that the mean fluorescence intensity of γ-H2AX and TUNEL in the irradiated group was significantly higher than in the non-irradiated group 2 days after irradiation(P<0.01),and that the proportion of EDU+and Ki67+cells in the irradiated group was significantly lower than in the non-irradiated group three days after irradiation(P<0.05).Conclusion Caco-2 cells and HUVECs co-culture on an organ chip can generate the biomimetic structure of human intestinal villus.Ionizing radiation has been found to shorten intestinal villus,increase DNA damage and apoptosis in intestinal epithelial cells,and inhibit the proliferation of these cells.
9.Endo-beta-N-acetylglucosaminidase: Possible Functions and Mechanisms
Xin-Rong LU ; Yong-Liang TONG ; Wei-Li KONG ; Lin ZOU ; Dan-Feng SHEN ; Shao-Xian LÜ ; Rui-Jie LIU ; Shao-Xing ZHANG ; Yu-Xin ZHANG ; Lin-Lin HOU ; Gui-Qin SUN ; Li CHEN
Progress in Biochemistry and Biophysics 2024;51(5):985-999
Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.
10.Impact of drought on Oncomelania hupensis snails breeding in the Poyang Lake area
Fei HU ; Shangbiao LÜ ; Yifeng LI ; Zongguang LI ; Tingting HE ; Jingzi XIE ; Min YUAN ; Dandan LIN
Chinese Journal of Schistosomiasis Control 2024;36(4):370-375
Objective To examine the impact of arid climates on distribution of Oncomelania hupensis snails in the Poyang Lake area, so as to provide insights into precision control of O. hupensis snails in the Poyang Lake area. Methods O. hupensis snails-infested grass islands in Hukou County, Lianxi District and Lushan City in the northern Poyang Lake area, and Jinxian County, Nanchang County and Poyang County in the southern Poyang Lake area were selected as the study areas, and the occurrence of frames with living snails and the mean density of living snails were captured from snail surveys in the study areas in spring and autumn each year from 2006 to 2023. Five years 2007, 2011, 2013, 2019 and 2022 were selected as drought years, and the mean daily water levels were collected at the Xingzi hydrological station in the drought years, normal flow year (2012) and flood year (2020). The numbers of days with water levels ranging from the lower elevation (11 m) to the upper elevation (16 m) for snail survival and the numbers of days with water levels of 11 m and below were collected in the Poyang Lake area, and the changes of snail indicators were compared in different grass islands in the Poyang Lake area before and after drought. Results The numbers of days with water levels ranging from 11 to 16 m were 110, 88, 136 d and 125 d at the Xingzi hydrological station in four drought years 2007, 2011, 2013 and 2019, which were less than in the flow year and flood year, and the days with water levels of 11 m and below were 242, 277, 220 d and 198 d in four drought years 2007, 2011, 2013 and 2019, which were longer than in the flow year and flood year. A total of 416 snails-infested marshlands were surveyed in the Poyang Lake area from 2006 to 2021, and the survey marshlands accounted for 43.12% (307/712) and 46.98% (109/232) of total marshlands in the southern and northern Poyang Lake areas, respectively. The median occurrence of frames with living snails and mean density of living snails were 0.60% (interquartile range, 4.04%) and 0.010 1 snail/0.1 m2 (interquartile range, 0.076 1 snail/0.1 m2) in drought years, which were both lower than those [1.33% (5.19%) and 0.022 8 (0.098 9) snail/0.1 m2] in non-drought years (χ2= 42.170 and 44.911, both P values < 0.01). The proportion of grass islands with a continuous decline in snail indicators was higher in the southern Poyang Lake area than in the northern Poyang Lake area after the next year of drought (24.24% vs. 2.33%; χ2 = 10.633, P < 0.01), and the proportion of grass islands with rebounding snail indicators was higher in the northern Poyang Lake area than in the southern Poyang Lake area (53.49% vs. 15.76%; χ2 = 26.966, P < 0.01). A longitudinal analysis of snail indicators in marshlands with rebounding snail indicators after drought showed 1 to 5 years for return to pre-drought snail status, with a median of 2 (interquartile range, 1) years, and snail status was more likely to rebound if the occurrence of frames with living snails and the mean density of living snails were 2.11% and 0.025 5 snail/0.1 m2 and greater in snails-infested grass islands. Conclusions Drought causes a remarkable decline in O. hupensis snail indicators in the Poyang Lake area, with a more remarkable impact in the southern Poyang Lake area, and 1 to 5 years are required for return to pre-drought snail status.

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