Robust underwater image enhancement with cascaded multi-level sub-networks and triple attention mechanism.

With the growing exploration of marine resources, underwater image enhancement has gained significant attention. Recent advances in convolutional neural networks (CNN) have greatly impacted underwater image enhancement techniques. However, conventional CNN-based methods typically employ a single network structure, which may compromise robustness in challenging conditions. Additionally, commonly used UNet networks generally force fusion from low to high resolution for each layer, leading to inaccurate contextual information encoding. To address these issues, we propose a novel network called Cascaded Network with Multi-level Sub-networks (CNMS), which encompasses the following key components: (a) a cascade mechanism based on local modules and global networks for extracting feature representations with richer semantics and enhanced spatial precision, (b) information exchange between different resolution streams, and (c) a triple attention module for extracting attention-based features. CNMS selectively cascades multiple sub-networks through triple attention modules to extract distinct features from underwater images, bolstering the network's robustness and improving generalization capabilities. Within the sub-network, we introduce a Multi-level Sub-network (MSN) that spans multiple resolution streams, combining contextual information from various scales while preserving the original underwater images' high-resolution spatial details. Comprehensive experiments on multiple underwater datasets demonstrate that CNMS outperforms state-of-the-art methods in image enhancement tasks.

Inhibiting the NLRP3 Inflammasome with MCC950 Alleviates Neurological Impairment in the Brain of EAE Mice.

Multiple sclerosis (MS) is a chronic disease that is characterized by demyelination and neuronal damage. Experimental autoimmune encephalomyelitis (EAE) mice are used to model the disease progression of MS and mirror MS-like pathology. Previous researches have confirmed that inhibition of NLRP3 inflammasome significantly alleviated the severity of EAE mice and the demyelination of spinal cord, but its effect on neuronal damage and oligodendrocyte loss in the brain remains unclear. In this study, female C57BL/6 mice were immunized with MOG35-55 and PTX to establish experimental autoimmune encephalomyelitis (EAE) model. MCC950, a selective NLRP3 inflammasome inhibitor, was used to investigate the effect of NLRP3 inflammasome on the pathological changes and glial cell activation in the brain of EAE mice by immunohistochemistry. Our results demonstrated that MCC950 ameliorated the neuronal damage, demyelination, and oligodendrocyte loss in the brain of EAE mice. This protective effect of MCC950 may be attributed to its ability to suppress the activation of glial cells and prevents microglia polarization to M1 phenotype. Our work indicates that inhibition of NLRP3 inflammasome has the therapeutic effects of neuroprotection through immunomodulation and is a promising therapeutic strategy for MS.

The response of ecological security to land use change in east and west subtropical China.

Regional land use change and ecological security have received considerable attention in recent years. The rapid economic development of Kunming and Fuzhou has resulted in environmental damage such as water pollution and urban heat island effect. It is thus important to conduct a comparative analysis of the ecological security response to land use/land cover change (LUCC) in different natural zones. Using the Google Earth Engine (GEE) platform, random forest and support vector machine methods were used to classify land cover types in the study area, after which the ArcGIS platform was used to analyze LUCC. The driving force-pressure-state-impact-response (DPSIR) model and entropy weight method were used to construct an ecological security evaluation system, and gray correlation was used to compare the ecological security responses to LUCC in Kunming and Fuzhou. The findings revealed that: (1) The average dynamic degrees of comprehensive land use in Kunming and Fuzhou from 1995 to 2020 were 1.05% and 0.55%, respectively; (2) From 1995 to 2020, the ecological security index values for Kunming and Fuzhou increased from 0.42 to 0.52 and from 0.36 to 0.68, respectively, indicating that Fuzhou's index is rising more rapidly; and (3)There is a strong correlation between LUCC and ecological security, the correlation between the woodland and the ecological security index is very strong in both places. The expansion of construction land may be an important reason for the reduced ecological security level in Fuzhou City, while water resources have a significant impact on the ecological security level of Kunming City.

Anti-obesity effects exerted by Dioscorea opposita Thunb. polysaccharides in diet-induced obese mice.

Obesity is characterized by chronic inflammation, insulin resistance, and gut microbiota dysbiosis. Dioscorea opposita Thunb. is a traditional food and medicine homolog from China. In the present study, polysaccharides isolated from a water extract of Dioscorea opposita Thunb. (DOTPs) were prepared. We showed that DOTPs reduced body weight, accumulation of fat tissues, insulin resistance, and inflammation in high-fat diet (HFD)-fed mice. Further experiments showed that DOTPs could regulate the composition of the gut microbiota in HFD mice. DOTPs supplementation in HFD-fed mice resulted in the reduction of the Firmicutes-to-Bacteroidetes ratio. We further demonstrated that DOTPs supplementation enhanced bacterial levels of Akkermansia and reduced levels of Ruminiclostridium_9. A significant reduction of glycolysis metabolism related to obesity and gut microbiota dysbiosis was also observed upon administration of DOTPs. Our results suggest that DOTPs can produce significant anti-obesity effects, by inhibiting systematic inflammation and ameliorating gut microbiota dysbiosis in diet-induced obese mice.

Dual-path joint correction network for underwater image enhancement.

Acquired underwater images often suffer from severe quality degradation, such as color shift and detail loss due to suspended particles' light absorption and scattering. In this paper, we propose a Dual-path Joint Correction Network (DJC-NET) to cope with the above degenerate issues, preserving different unique properties of underwater images in a dual-branch way. The design of the light absorption correction branch is to improve the selective absorption of light in water and remove color distortion, while the light scattering correction branch aims to improve the blur caused by scattering. Concretely, in the light absorption correction path, we design the triplet color feature extraction module, which balances the triplet color distribution of the degraded image through independent feature learning between R, G, and B channels. In the light scattering correction path, we develop a dual dimensional attention mechanism to extract the texture information from the features, aiming to recover sufficient details by more effective feature extraction. Furthermore, our method utilizes the multi-scale U-net to adaptively fusion features from different paths to generate enhanced images. Extensive visual and objective experimental results demonstrate that our method outperforms state-of-the-art methods in various underwater scenes.

Underwater image enhancement via two-level wavelet decomposition maximum brightness color restoration and edge refinement histogram stretching.

Underwater images suffer color distortions and low contrast. This is because the light is absorbed and scattered when it travels through water. Different underwater scenes result in different color deviations and levels of detail loss in underwater images. To address these issues of color distortion and low contrast, an underwater image enhancement method that includes two-level wavelet decomposition maximum brightness color restoration, and edge refinement histogram stretching is proposed. First, according to the Jaffe-McGlamery underwater optical imaging model, the proportions of the maximum bright channel were obtained to correct the color of underwater images. Then, edge refinement histogram stretching was designed, and edge refinement and denoising processing were performed while stretching the histogram to enhance contrast and noise removal. Finally, wavelet two-level decomposition of the color-corrected and contrast-stretched underwater images was performed, and the decomposed components in equal proportions were fused. The proposed method can restore the color and detail and enhance the contrast of the underwater image. Extensive experiments demonstrated that the proposed method achieves superior performance against state-of-the-art methods in visual quality and quantitative metrics.

Underwater image restoration via background light estimation and depth map optimization.

In underwater images, the significant sources of distortion are light attenuation and scattering. Existing underwater image restoration technologies cannot deal with the poor contrast and color distortion bias of underwater images. This work provides a new underwater image restoration approach relying on depth map optimization and background light (BL) estimation. First, we build a robust BL estimation model that relies on the prior features of blurriness, smoothness, and the difference between the intensity of the red and blue-green channels. Second, the red-light intensity, difference between light and dark channels, and disparity of red and green-blue channels by considering the hue are used to calculate the depth map. Then, the effect of artificial light sources on the underwater image is removed using the adjusted reversed saturation map. Both the subjective and objective experimental results reveal that the images produced by the proposed technology provide more remarkable visibility and superior color fidelity.

Ecological security assessment at different spatial scales in central Yunnan Province, China.

Healthy ecosystems are the basis of social and economic development. It is of great significance to conduct ecological security assessments in rapidly urbanization areas. Based on the driving forces, pressure, state, impact, and response (DPSIR) model, five years (1995, 2000, 2005, 2010 and 2015) of remote sensing images, social and economic statistics, and field survey data were used to establish an ecological security assessment index system. The ecological security assessment of central Yunnan Province (CYP) urban agglomeration was conducted at the 1 km × 1 km pixel scale and at the county scale based on the multilevel weighted comprehensive index method. The results showed that: (1) With 2005 as the turning point, the ecological security situation in CYP first decreased and then increased. (2) The ecological security at the county scale was mainly categorized as unsafe. At the pixel scale, ecologically unsafe and relatively unsafe areas were mainly distributed in central, northern, and western CYP. (3) The ecological security deterioration and strengthened spatial distribution differences were caused by habitat fragmentation, different physical geographical conditions, and population agglomeration. These results can provide a basis for the coordination and sustainability of economic development and environmental protection in urban agglomerations with rapid urbanization.

Underwater image restoration by red channel compensation and underwater median dark channel prior.

Underwater images often show low contrast, blurring, and color distortion due to the absorption and scattering of light. In contrast to existing underwater image restoration methods, we propose an underwater image restoration method with red channel compensation and blue-green channel restoration. First, a proposed approach relies on the hue and attenuation differences between different color channels of the underwater image to estimate the background light. Then, the red channel is enhanced according to a perfect reflection assumption algorithm. Finally, a new median underwater dark channel prior (MUDCP) is proposed to precisely estimate the blue-green channel transmission map. Experimental results show that our method significantly improves contrast, removes color bias, and preserves more detail than other underwater restoration techniques.

Lupeol triggers oxidative stress, ferroptosis, apoptosis and restrains inflammation in nasopharyngeal carcinoma via AMPK/NF-κB pathway.

OBJECTIVE: Nasopharyngeal carcinoma is a malignant tumor with high incidence in Asia. This study investigated the anti-tumor capacities of lupeol in nasopharyngeal carcinoma. METHODS: CCK-8 assay was employed to select the suitable concentration and intervention time of lupeol in 5-8 F and CNE1 cells. The anti-cancer impacts of lupeol were evaluated by flow cytometry, ROS generation, western blotting, ELISA, iron assay, lipid peroxidation, mitochondrial membrane potential (MMP), TUNEL, and immunohistochemistry assays. Additionally, levels of AMPK/NF-κB pathway-related proteins were tested by western blotting. RESULTS: Cell viability was notably decreased after administration of lupeol ≧ 20 µM. 20 µM and 40 µM lupeol induced cell apoptosis, enhanced oxidative stress and restrained immune response in nasopharyngeal carcinoma cells to some extent, as evidenced by the elevation of apoptotic rate, Bax and cleaved caspase-3 expression, ROS production and malondialdehyde level, and reduction of levels of Bcl-2, MMP, superoxide dismutase, TNF-α, IL-6 and IL-1ß. Also, lupeol promoted the iron secretion and lipid peroxidation, the effects of which were reversed by ferroptosis inhibitor (Fer-1). The inhibitory impacts of lupeol at the doses of 20 µM and 40 µM on glutathione and GPX4 levels were observed. Importantly, lupeol significantly elevated AMPKα phosphorylation, and reduced the levels of p-IκBα and nuclear NF-κB p65. Rescue assay stated that siAMPK could neutralize the above impacts of lupeol. Moreover, lupeol suppressed tumorigenesis of xenografts in nude mice. CONCLUSION: Lupeol exerted the anti-cancer impacts by inducing oxidative stress, ferroptosis and apoptosis, and suppressing inflammation via the AMPK/NF-κB pathway in nasopharyngeal carcinoma.

Ribophorin II promotes the epithelial-mesenchymal transition and aerobic glycolysis of laryngeal squamous cell carcinoma via regulating reactive oxygen species-mediated Phosphatidylinositol-3-Kinase/Protein Kinase B activation.

Ribophorin II (RPN2), a part of an N-oligosaccharyl transferase complex, plays vital roles in the development of multiple cancers. Nevertheless, its biological role in laryngeal squamous cell carcinoma (LSCC) remains unclear. The RPN2 expression levels in LSCC tissues and cell lines (AMC-HN-8 and TU212) were measured using real-time PCR, immunohistochemistry, or Western blot. The influences of RPN2 on the proliferation, migration, epithelial-mesenchymal transition, and aerobic glycolysis of LSCC cells were investigated after upregulation or downregulation of RPN2 in vitro and in vivo. Mechanically, we assessed the impact of RPN2 on the reactive oxygen species (ROS)/Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (Akt) signaling pathway. We found that compared with the control, RPN2 was highly expressed in LSCC tissues and cells. Overexpression of RPN2 elevated the proliferation, migration, glucose uptake, lactate production release, and levels of Vimentin, hexokinase-2 (HK-2), pyruvate dehydrogenase kinase 1 (PDK1), lactate dehydrogenase A (LDHA), and ROS, but inhibited E-cadherin expression in AMC-HN-8 cells. Knockdown of RPN2 in TU212 cells showed opposite effects on the above indexes. Meanwhile, RPN2 upregulation increased the levels of p-PI3K/PI3K and p-Akt/Akt, which were attenuated by N-acetyl-L-cysteine (NAC), an ROS inhibitor. Both NAC and PI3K inhibitor LY294002 could reverse the effects of RPN2 overexpression on the malignant phenotypes of LSCC cells. In xenografted mice, silencing RPN2 expression reduced tumor growth, ROS production, and levels of Ki-67, Vimentin, LDHA, and p-Akt/Akt, but enhanced E-cadherin expression. In conclusion, our data suggested that RPN2 promoted the proliferation, migration, EMT, and glycolysis of LSCC via modulating ROS-mediated PI3K/Akt activation.

Precursor-Directed Biosynthesis of Talaroenamine Derivatives Using a Yellow River Wetland-Derived Penicillium malacosphaerulum.

Precursor-directed biosynthesis was used to introduce selected aniline derivatives into the talaroenamine pathway, which had recently been defined from a Yellow River wetland-derived Penicillim malacosphaerulum HPU-J01. The known talaroenamine B (1) and six previously undescribed talaroenamine derivatives, talaroenamines F-K (2-7), were generated and structurally characterized. The aniline derivatives are introduced via nonenzymatic addition to the reactive intermediate cyclohexanedione. Compound 2 was active against Bacillus cereus with an MIC value of 0.85 µg/mL.

Underwater image restoration via depth map and illumination estimation based on a single image.

For the enhancement process of underwater images taken in various water types, previous methods employ the simple image formation model, thus obtaining poor restoration results. Recently, a revised underwater image formation model (i.e., the Akkaynak-Treibitz model) has shown better robustness in underwater image restoration, but has drawn little attention due to its complexity. Herein, we develop a dehazing method utilizing the revised model, which depends on the scene depth map and a color correction method to eliminate color distortion. Specifically, we first design an underwater image depth estimation method to create the depth map. Subsequently, according to the depth value of each pixel, the backscatter is estimated and removed by the channel based on the revised model. Furthermore, we propose a color correction approach to adjust the global color distribution of the image automatically. Our method only uses a single underwater image as input to eliminate lightwave absorption and scattering influence. Compared with state-of-the-art methods, both subjective and objective experimental results show that our approach can be applied to various real-world underwater scenes and has better contrast and color.

Underwater image restoration via feature priors to estimate background light and optimized transmission map.

Underwater images frequently suffer from color casts and poor contrast, due to the absorption and scattering of light in water medium. To address these two degradation issues, we propose an underwater image restoration method based on feature priors inspired by underwater scene prior. Concretely, we first develop a robust model to estimate the background light according to feature priors of flatness, hue, and brightness, which can effectively relieve color distortion. Next, we compensate the red channel of color corrected image to revise the transmission map of it. Coupled with the structure-guided filter, the coarse transmission map is refined. The refined transmission map preserves the edge information while improving the contrast. Extensive experiments on diverse degradation scenes demonstrate that our method achieves superior performance against several state-of-the-art methods.

BMS-599626, a Highly Selective Pan-HER Kinase Inhibitor, Antagonizes ABCG2-Mediated Drug Resistance.

Multidrug resistance (MDR) associated with the overexpression of ABC transporters is one of the key causes of chemotherapy failure. Various compounds blocking the function and/or downregulating the expression of these transporters have been developed over the last few decades. However, their potency and toxicity have always been a concern. In this report, we found that BMS-599626 is a highly potent inhibitor of the ABCG2 transporter, inhibiting its efflux function at 300 nM. Our study repositioned BMS-599626, a highly selective pan-HER kinase inhibitor, as a chemosensitizer in ABCG2-overexpressing cell lines. As shown by the cytotoxicity assay results, BMS-599626, at noncytotoxic concentrations, sensitizes ABCG2-overexpressing cells to topotecan and mitoxantrone, two well-known substrates of ABCG2. The results of our radioactive drug accumulation experiment show that the ABCG2-overexpressing cells, treated with BMS-599626, had an increase in the accumulation of substrate chemotherapeutic drugs, as compared to their parental subline cells. Moreover, BMS-599626 did not change the protein expression or cell surface localization of ABCG2 and inhibited its ATPase activity. Our in-silico docking study also supports the interaction of BMS-599626 with the substrate-binding site of ABCG2. Taken together, these results suggest that administration of chemotherapeutic drugs, along with nanomolar concentrations (300 nM) of BMS-599626, may be effective against ABCG2-mediated MDR in clinical settings.

Shikonin inhibits growth, invasion and glycolysis of nasopharyngeal carcinoma cells through inactivating the phosphatidylinositol 3 kinase/AKT signal pathway.

Nasopharyngeal carcinoma (NPC) is a malignant tumor which is commonly found in East Asia and Africa. The present clinical treatment of NPC is still mainly based on chemotherapeutics and is prone to drug resistance and adverse reactions. Shikonin has been demonstrated to play the antitumor effect in various cancers. However, the specific effects and related regulatory mechanism of Shikonin in NPC have not been clearly declared yet. Cell viability was valued through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation was detected through colony formation assay and Bromodeoxyuridine (BrdU) assay. Hochest 33258 staining was used to value cell apoptosis. Cell migration and invasion were valued through wound healing and transwell invasion assay, respectively. Glucose uptake, lactate release, ATP level and pyruvate kinase M2 isoform (PKM2) activity were measured using corresponding assay kits. Western blotting was used to examine the expression of proteins related to cell proliferation, cell apoptosis, cell migration and the phosphatidylinositol 3 kinase (PI3K)/AKT signal pathway. We found that Shikonin treatment effectively suppressed cell proliferation and induced obvious cell apoptosis compared with the control. Besides, Shikonin treatment suppressed cell migration and invasion effectively. The detection about glycolysis showed that Shikonin treatment suppressed cell glucose uptake, lactate release and ATP level. The activity of PKM2 was also largely inhibited by Shikonin. Further study revealed that the PI3K/AKT signal pathway was inactivated by Shikonin treatment. In addition, the inducer of the PI3K/AKT signal pathway largely abolished the antitumor effect of Shikonin on cell proliferation, cell apoptosis, cell mobility and aerobic glycolysis in NPC cells. Shikonin inhibits growth and invasion of NPC cells through inactivating the PI3K/AKT signal pathway.

High SRC-1 and Twist1 expression predicts poor prognosis and promotes migration and invasion by inducing epithelial-mesenchymal transition in human nasopharyngeal carcinoma.

Steroid receptor coactivator 1 (Src-1) and Twist1 are aberrantly upregulated in a variety of tumors and play an important role in tumor progression. However, the exact role of Src-1 and Twist1 in nasopharyngeal carcinoma (NPC) is uncertain. In this study, we investigated the possible prognostic value and biological effect of Src-1 and Twist1 in NPC. Src-1 and Twist1 expression was detected in a cohort of NPC patients (n = 134) by qRT-PCR. Kaplan-Meier survival analysis was used comparing overall survival (OS) and progression-free survival (PFS). Multivariate analysis was performed using the Cox proportional hazard regression model. Biologic effect of Src-1 and Twist1 in NPC cell lines was evaluated by western blot, colony formation assay, soft agar assay, scratch wound healing assay, transwell invasion assay and tumor xenografts growth. We have found that Src-1 and Twist1 were aberrantly upregulated in human NPC tissues, and associated with advanced tumor stage, distant metastasis and unfavorable prognosis. Knockdown of Src-1 or Twist1 in human NPC cell line CNE-1 suppressed colony formation, anchorage-independent growth, cell migration, invasion and tumor xenografts growth, while enforced expression of Src-1 or Twist1 in human NPC cell line HNE-2 promotes anchorage-independent growth, cell migration and invasion. In addition, Src-1 and Twist1 could suppress E-cadherin expression and increase Vimentin expression, thus suggested that Src-1 and Twist1 enhanced the malignant behaviors of NPC cells via inducing epithelial-mesenchymal transition (EMT). Our data indicated that Src-1 and Twist1 could be possible prognostic biomarkers and potential therapy targets for patients with NPC.

Preparation of non-sintered fly ash filter (NSFF) for ammonia nitrogen adsorption.

In accordance with China's goal of 'treating wastes with wastes, turning wastes into treasure', a non-sintered fly ash filter (NSFF) with sewage sludge as additive was prepared. It consists of 70.9% fly ash, 7% sewage sludge, 9% cement, 7.1% CaO, 1% NaHCO3 and 5% sodium silicate solution. After mixing, 34 g/(100 g dry material) water was added, and then was granulated and steam cured under 80°C for 16 h. NSFF's main performance indexes include specific surface area (SSA) of 17.038 m2 g-1, filter media breaking rate (FMBR) of 2.2%, apparent density (AD) of 1140 kg m-3, and porosity of 41.67%, meeting the Chinese Standard CJ/T 299-2008. This NSFF has a larger SSA and a lower AD comparing with the other similar non-sintered fly ash ceramsite products. Moreover, leaching toxicity of the NSFF has met the Chinese Standards for Hazardous Wastes (GB5085.3-2007). Therefore, the NSFF is effective and safe to use as a water treatment filter media. The NSFF's adsorption characteristics for ammonia nitrogen was investigated. Results showed that the optimized parameters for ammonia nitrogen adsorption are as follows, NSFF dosage at 5 g, initial ammonia nitrogen concentration of 225 mg L-1, pH at 7, contact time of 12 h and temperature at 30°C. Under the optimum conditions, the adsorption capacity of NSFF for ammonia nitrogen was 4.25 mg g-1. The adsorption process can be best described by Langmuir isotherm and pseudo-second-order kinetic model. The proposed adsorption mechanism include adsorption and cation exchange.

Anti-tumor effect of HOTAIR-miR-613-SNAI2 axis through suppressing EMT and drug resistance in laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) is the main pathological type of laryngeal cancer, which attacks the head and neck. Our present study aims to investigate the effect of long non-coding RNA (LncRNA) HOX transcript antisense RNA (HOTAIR) on epithelial mesenchymal transition (EMT) and drug resistance in LSCC. Firstly, the level of HOTAIR was found to be overexpressed in LSCC tissues compared with normal healthy tissues. Then, increased EMT and drug resistance were suppressed by specific HOTAIR shRNA effectively in LSCC cell lines. Besides, miR-613 was predicted to be a target of HOTAIR through bioinformatics analysis. Meanwhile, we found that a down-regulated level of miR-613 could be increased by HOTAIR shRNA and suppressed by LncRNA HOTAIR transfection in LSCC cells. The targeting relationship between miR-613 and HOTAIR was further demonstrated by a luciferase report assay. What is more, the inhibiting effect of HOTAIR shRNA on EMT and drug resistance was obviously abolished by the miR-613 inhibitor. Moreover, SNAI2, a critical regulator of EMT, was predicted as a target of miR-613 through bioinformatics analysis and luciferase report assays. As expected, the level of SNAI2 could be suppressed by HOTAIR shRNA and increased by the miR-613 inhibitor. Additionally, we discovered that SANI2 shRNA had similar inhibiting effect on EMT and drug resistance with HOTAIR shRNA in LSCC cells. Finally, the in vivo experiment further demonstrated that HOTAIR shRNA restricted tumor growth, EMT and drug resistance. Additionally, HOTAIR shRNA transfection could also increase the level of miR-613 and decrease the level of SNAI2 in vivo. Taken together, our research for the first time revealed the effect of the HOTAIR-miR-613-SNAI2 axis on EMT and drug resistance in LSCC, providing new targets for LSCC diagnosis and treatment.

Efficacy of chitosan dressing on endoscopic sinus surgery: a systematic review and meta-analysis.

Chitosan dressing might be promising to promote the recovery following endoscopic sinus surgery (ESS). However, the results remain controversial. We conducted a systematic review and meta-analysis to explore the influence of chitosan dressing on ESS. PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of chitosan dressing on endoscopic sinus surgery were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcomes were synechia and hemostasis. Meta-analysis was performed using random-effect model. Four RCTs involving 268 patients were included in the meta-analysis. Overall following ESS, compared with control intervention, chitosan dressing significantly reduced synechia (RR = 0.25; 95% CI 0.13-0.49; P < 0.0001) and promoted hemostasis (RR = 1.70; 95% CI 1.37-2.11; P < 0.00001), but showed no impact on granulations (RR = 1.18; 95% CI 0.72-1.95; P = 0.52), mucosal edema (RR = 0.88; 95% CI 0.60-1.29; P = 0.51), crusting (RR = 0.85; 95% CI 0.48-1.53; P = 0.60), and infection (RR = 0.88; 95% CI 0.51-1.52; P = 0.64). Compared to control intervention, chitosan dressing could significantly decrease edema and improve hemostasis, but had no effect on granulations, mucosal edema, crusting and infection.