In vitro dynamic digestion properties and fecal fermentation of Dictyophora indusiata polysaccharide: Structural characterization and gut microbiota.

The in vitro dynamic digestive model more realistically simulates the human digestive system compared to static digestive model. In this study, the dynamic in vitro stomach-intestine digestive system and fecal fermentation was used to investigate the dynamic digestion properties and fermentation properties of Dictyophora indusiata polysaccharide. The results showed that there were no significant changes in molecular weight, functional groups and surface morphology after the in vitro dynamic simulated digestion, indicating that D. indusiata polysaccharide maintained a relatively stable structure during the dynamic in vitro salivary-gastrointestinal digestion. In addition, D. indusiata polysaccharide improved the abundance of beneficial bacteria, including Blautia, Coprobacter and Fusicatenibacter. It is remarkable that D. indusiata polysaccharide significantly increased the level of acetic acid and propionic acid. In conclusion, these results suggested that D. indusiata polysaccharide was a potential source of prebiotics, which provides a basis for the development of D. indusiata polysaccharide in the food or medical field.

Qingrexiaoji Recipe Regulates the Differentiation of M2 TAM via miR-29 in GC.

BACKGROUND: Gastric cancer, one of the most familiar adenocarcinomas of the gastrointestinal tract, ranks third in the world in cancer-related deaths. Traditional Chinese medicine can suppress the growth of tumors, and the underlying mechanism may be associated with the tumor microenvironment. Here, we investigated the anti-cancer effects of the Qingrexiaoji recipe on gastric cancer and the underlying molecular mechanism. METHODS: An in vivo nude mouse model was established, and the expression of CD206, CD80, and M2 phenotype-related proteins (Arg-1, Fizz1) was obtained by flow cytometry and western blotting. The expressions of the M2 phenotype-related cytokines were examined by ELISA. RESULTS: Qingrexiaoji recipe inhibited gastric tumor growth and downregulated the expression of CD206, IFN-γ, IL-13, IL-4, and TNF-α in vivo. Qingrexiaoji recipe deceased M2 phenotypic polarization by upregulating microRNA (miR)-29a-3p level. Luciferase activity assays showed that HDAC4 is a potential target of miR-29a-3p. In cells co-transfected with HDAC4 siRNA and miR-29a-3p inhibitor and treated with IL-4 and Qingrexiaoji recipe, the miR-29a-3p inhibitorinduced increase of M2 phenotypic polarization was reversed. CONCLUSION: In summary, these results suggested that the Qingrexiaoji recipe regulated M2 macrophage polarization by regulating miR-29a-3p/HDAC4, providing a different and innovative treatment for gastric cancer.

ARID1A loss sensitizes colorectal cancer cells to floxuridine.

The loss-of-function mutation of AT-rich interactive domain 1A (ARID1A) frequently occurs in various types of cancer, making it a promising therapeutic target. In the present study, we performed a screening of an FDA-approved drug library in ARID1A isogenic colorectal cancer (CRC) cells and discovered that ARID1A loss sensitizes CRC cells to floxuridine (FUDR), an antineoplastic agent used for treating hepatic metastases from CRC, both in vivo and in vitro. As a pyrimidine analogue, FUDR induces DNA damage by inhibiting thymidylate synthase (TS) activity. ARID1A, as a regulator of DNA damage repair, when lost, exacerbates FUDR-induced DNA damage, leading to increased cell apoptosis. Specifically, ARID1A deficiency impairs DNA damage repair by downregulating Chk2 phosphorylation, thereby sensitizing cancer cells to FUDR. Notably, we found that FUDR exhibited increased sensitivity in ARID1A-deficient cells compared to 5-fluorouracil (5-FU), a commonly used anticancer drug for CRC. This suggests that FUDR is superior to 5-FU in treating ARID1A-deficient CRC. In conclusion, ARID1A loss significantly heightens sensitivity to FUDR by promoting FUDR-induced DNA damage in CRC. These findings offer a novel therapeutic approach for the treatment of CRC characterized by ARID1A loss-of-function mutations.

Relevance of combined influence of nutritional and inflammatory status on non-alcoholic fatty liver disease and advanced fibrosis: A mediation analysis of lipid biomarkers.

BACKGROUND AND AIM: This study aimed to investigate the relationship between advanced lung cancer inflammation index (ALI) and non-alcoholic fatty liver disease (NAFLD) and advanced liver fibrosis (AF). METHODS: A total of 5642 individuals from the National Health and Nutrition Examination Survey (NHANES) between 2017 and 2020 were examined. Limited cubic spline regression model, and weighted logistic regression were employed to determine if ALI levels were related to the prevalence of NAFLD and AF. Additionally, a mediating analysis was conducted to investigate the role of lipid biomarkers, such as total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C), in the effects of ALI on the prevalence of NAFLD and AF. RESULTS: After adjusting for potential confounders, a significant positive association was found between ALI with NAFLD and AF prevalence. Compared with those in ALI Tertile 1, participants in Tertile 3 had higher odds of NAFLD prevalence (odds ratio [OR]: 3.16; 95% confidence interval [CI]: 2.52-3.97) and AF (OR: 3.17; 95% CI: 2.30-4.36). Participants in both Tertile 2 and Tertile 3 had lower odds of developing AF (P for trend = 0.005). Moreover, we discovered a nonlinear association between ALI and NAFLD. An inflection point of 74.25 for NAFLD was identified through a two-segment linear regression model. Moreover, TC and HDL-C levels mediated the association between ALI and NAFLD by 10.2% and 4.2%, respectively (both P < 0.001). CONCLUSION: Our findings suggest that higher ALI levels are positively associated with an increased prevalence of NAFLD and AF, partly mediated by lipid biomarkers.

Highly stable and active catalyst in fuel cells through surface atomic ordering.

Shape-controlled alloy nanoparticle catalysts have been shown to exhibit improved performance in the oxygen reduction reaction (ORR) in liquid half-cells. However, translating the success to catalyst layers in fuel cells faces challenges due to the more demanding operation conditions in membrane electrode assembly (MEA). Balancing durability and activity is crucial. Here, we developed a strategy that limits the atomic diffusion within surface layers, fostering the phase transition and shape retention during thermal treatment. This enables selective transformation of platinum-iron nanowire surfaces into intermetallic structures via atomic ordering at a low temperature. The catalysts exhibit enhanced MEA stability with 50% less Fe loss while maintaining high catalytic activity comparable to that in half-cells. Density functional calculations suggest that the ordered intermetallic surface stabilizes morphology against rapid corrosion and improves the ORR activity. The surface engineering through atomic ordering presents potential for practical application in fuel cells with shape-controlled Pt-based alloy catalysts.

Background-Free Imaging of Food Freshness Using Curcumin-Functionalized Upconversion Reversible Hydrogel Patch.

Functionalized upconversion nanomaterials can overcome the drawbacks faced of strong background interference, photodamage, and spectral overlap by conventional optical labeling. Here, curcumin-functionalized upconversion hydrogel patch is designed with background-free and reversible for food freshness monitoring by ultra-sensitive response to biogenic amines. By loading the probes onto hydrogel patch, utilizing the good ductility to solve the problem of non-smooth surface coverage, thus accurately capturing biogenic amines. The presence of biogenic amines leads to the conversion of the diketone group on the probe to enolate ions, which triggers fluorescence resonance energy transfer (FRET) and ultimately causes the upconverted fluorescence to gradually change from green to red. The probe exhibits good detection capability for biogenic amines with a low limit of detection (LOD) of 2.73 µm. Interestingly, the patch can be restored to its initial state after water rinsing, realizing reversible detection of biogenic amines. Additionally, combining the color recognition system of smartphone can convert the imaging signal into a data signal to achieve quantitative analysis and show a reliable assessment comparable to the results of high performance liquid chromatography (HPLC). This study demonstrates the practical applicability in real-time monitoring of freshness, suggests great potential in developing optical nano-sensing strategy to ensure food safety.

Influence of Si on the Elevated-Temperature Mechanical and Creep Properties of Al-Cu 224 Cast Alloys during Thermal Exposure.

The influence of Si content (0.1-0.8 wt.%) on the development of precipitation microstructures and the resultant mechanical and creep properties during thermal exposure, up to 1000 h at 300 °C, in Al-Cu 224 cast alloys, was systematically investigated. The room and elevated temperature yield strength (YS) increased with increasing Si content under the T7 condition, which was attributed to the fact that the Si promoted the precipitation of fine θ'. However, Si increased the coarsening of θ' during thermal exposure at 300 °C, and the alloys with low Si exhibited a higher YS and creep resistance at elevated temperatures than high Si alloys. The mechanical strength and creep resistance were mainly controlled by the precipitation strengthening of the predominant θ' phase. Because of the high mechanical strength and creep resistance of the 0.1Si alloy during long-term thermal exposure, the Si level in Al-Cu alloys should be maintained at a low level of 0.1 wt.% for high-temperature applications. The strengthening mechanisms were quantitatively analyzed, based on the characteristics of the precipitate. The predicted YS values under different exposure conditions agreed well with the experimentally measured values.

A 47-Year-old Asian female with tracheobronchial space-occupying lesions caused by chronic lymphocytic leukemia.

CASE PRESENTATION: A 47-year-old Asian woman was admitted with worsening chest tightness and dyspnea for 10 days. Computed tomography (CT) showed changes in the trachea and segmental bronchi. Pulmonary function results suggestive of severe obstructive ventilatory dysfunction. Bronchoscopic findings showed the presence of multiple nodular lesions in the patient's trachea and left and right main bronchi. Bronchoscopic biopsy, lymph node biopsy and bone marrow aspiration flow cytometry test results led to a definitive diagnosis of chronic lymphocytic leukemia (CLL), staged as Binet stage B and Rai stage 2.

Chemical structure and prebiotic activity of a Dictyophora indusiata polysaccharide fraction.

This study aimed to investigate the chemical structure and prebiotic activity of a Dictyophora indusiata polysaccharide fraction DIP0p. Our results indicated that DIP0p belongs to a heteropolysaccharide composed of glucose, galactose, mannose and xylose, accounting for 53.25 %, 24.18 %, 19.19 % and 3.37 %, respectively. Methylation and NMR results suggested that the main glycosidic bonds of DIP0p is →3)-Glcp-(1 â†’ with →4)-Glcp-(1→, →3,4)-Glcp-(1→, →3,4)-Galp-(1 â†’ and →6)-Manp-(1 â†’ branches. In addition, DIP0p increased the abundance of benificial bacteria during the in vitro fecal fermentation, including Phascolarctobacterium, Parabacteroides and Bifidobacterium. It is remarkable that DIP0p improved the level of acetic acid, propionic acid, and butyric acid of the fermentation system, which were 1.31, 1.52, and 2.64 folds higher than the Controls, respectively. In summary, this study comprehensively analyzed the structure and probiotic activity of DIP0p, which providing a theoretical basis for the development of the functional foods.

Experimental Evaluation of an Ultrasound-Guided High-Intensity-Focused Ultrasound Probe for Sonication of Artery.

OBJECTIVES: This study aimed to develop an ultrasound-guided high-intensity-focused ultrasound (USgHIFU) probe for arterial sonication and to evaluate vascular contraction. METHODS: The USgHIFU probe comprised two confocal spherical transducers for sonication and a US color Doppler flow imaging probe for guidance. A vessel-mimicking phantom was sonicated in two directions. In the vascular radial direction, an isolated rabbit aorta embedded in ex vivo pork liver was sonicated at different acoustic powers (245 and 519 W), flow rates (25, 30, and 50 mL/minute), and sonication energies (519, 980, and 1038 J). Changes in the postsonication vessels were evaluated using US imaging, microscopic observation, and histopathological analysis. RESULTS: Beam focusing along the vascular radial direction caused significant deformation of both tube walls (n = 4), whereas focusing along the axial direction only affected the contraction of the anterior wall (n = 4). The contraction index (Dc) of the vessel sonicated at 245 W and 980 J was 56.2 ± 9.7% (n = 12) with 25 mL/minute. The Dc of the vessel sonicated at 519 W and 1038 J was 56.5 ± 7.8% (n = 17). The Dc of the vessel sonicated at 519 J total energy was 18.3 ± 5.1% (n = 12). CONCLUSION: The developed USgHIFU probe induced greater vascular contractions by covering a larger area of the vessel wall in the radial direction. Sonication energy affects vascular contraction through temperature elevation of the vessel wall. When the acoustic power was high, an increase in acoustic power, even with comparable sonication energy, did not result in greater vessel contraction.

The pathways and the mechanisms by which Cryptococcus enters the brain.

Generally, Cryptococcus initially infects the respiratory tract, but can spread, eventually crossing the blood-brain barrier (BBB) and causing meningitis or meningoencephalitis. Specifically, Cryptococcus invades the vascular endothelial cells of the BBB, from which it enters the brain. The main mechanisms through which Cryptococcus crosses the BBB are transcellular traversal, the paracellular pathway, and via Trojan horse. In this paper, the mechanisms by which Cryptococcus crosses the BBB were explained in detail. In addition to pathways of entry to the brain, this paper presents a discussion on some rare cryptococcal infections and provides some insights for future research directions.

Tinidazole mouth rinse for the treatment of oral lichen planus: an observational pilot study.

BACKGROUND: Given the limited treatment options available for oral lichen planus (OLP), a study was undertaken to obtain preliminary information on the therapeutic efficacy of tinidazole mouth rinse in patients with OLP. METHODS: A prospective, open-label pilot study was conducted to assess the efficacy of thrice-daily tinidazole mouth rinse for one week in OLP patients (n = 27). Reticulation/erythema/ulceration (REU) scores and visual analog scale (VAS) scores were used to measure lesions at baseline and after one week of treatment. Mucosal samples were collected, and the abundance of Fusobacterium nucleatum was quantified using RT-PCR. Statistical analysis using t-test, Wilcoxon signed rank test and Pearson correlation test. RESULTS: After treatment, VAS scores significantly decreased in both reticular (P = 0.03) and erosive OLP patients (P = 0.003). However, REU scores significantly decreased only in erosive OLP patients (P = 0.002). The relative abundance of Fusobacterium nucleatum on the damaged mucosa surface significantly decreased in all OLP patients (P = 0.01). In erosive OLP patients, the triamcinolone group showed a significantly greater improvement in VAS scores compared to the tinidazole group (P = 0.01). However, there was no statistically significant correlation between the relative abundance of Fusobacterium nucleatum and REU scores in OLP patients (r = 0.0754, P = 0.61). CONCLUSION: Tinidazole mouth rinse showed potential in reducing disease severity in OLP patients and was well-tolerated, suggesting its viability as a local therapeutic option. However, randomized controlled studies are warranted to confirm these preliminary findings.

Sheep (Ovis aries) Milk Exosomal miRNAs Attenuate Dextran Sulfate Sodium-Induced Colitis in Mice via TLR4 and TRAF-1 Inhibition.

Mammalian milk exosomal miRNAs play an important role in maintaining intestinal immune homeostasis and protecting epithelial barrier function, but the specific miRNAs and whether miRNA-mediated mechanisms are responsible for these benefits remain a matter of investigation. This study isolated sheep milk-derived exosomes (sheep MDEs), identifying the enriched miRNAs in sheep MDEs, oar-miR-148a, and oar-let-7b as key components targeting TLR4 and TRAF1, which was validated by a dual-luciferase reporter assay. In dextran sulfate sodium-induced colitis mice, administration of sheep MDEs alleviated colitis symptoms, reduced colonic inflammation, and systemic oxidative stress, as well as significantly increased colonic oar-miR-148a and oar-let-7b while reducing toll-like receptor 4 (TLR4) and TNF-receptor-associated factor 1 (TRAF1) level. Further characterization in TNF-α-challenged Caco-2 cells showed that overexpression of these miRNAs suppressed the TLR4/TRAF1-IκBα-p65 pathway and reduced IL-6 and IL-12 production. These findings indicate that sheep MDEs exert gastrointestinal anti-inflammatory effects through the miRNA-mediated modulation of TLR4 and TRAF1, highlighting their potential in managing colitis.

Application research on the diagnosis of classic trigeminal neuralgia based on VB-Net technology and radiomics.

BACKGROUND: This study aims to utilize the deep learning method of VB-Net to locate and segment the trigeminal nerve, and employ radiomics methods to distinguish between CTN patients and healthy individuals. METHODS: A total of 165 CTN patients and 175 healthy controls, matched for gender and age, were recruited. All subjects underwent magnetic resonance scans. VB-Net was used to locate and segment the bilateral trigeminal nerve of all subjects, followed by the application of radiomics methods for feature extraction, dimensionality reduction, feature selection, model construction, and model evaluation. RESULTS: On the test set for trigeminal nerve segmentation, our segmentation parameters are as follows: the mean Dice Similarity Coefficient (mDCS) is 0.74, the Average Symmetric Surface Distance (ASSD) is 0.64 mm, and the Hausdorff Distance (HD) is 3.34 mm, which are within the acceptable range. Analysis of CTN patients and healthy controls identified 12 features with larger weights, and there was a statistically significant difference in Rad_score between the two groups (p < 0.05). The Area Under the Curve (AUC) values for the three models (Gradient Boosting Decision Tree, Gaussian Process, and Random Forest) are 0.90, 0.87, and 0.86, respectively. After testing with DeLong and McNemar methods, these three models all exhibit good performance in distinguishing CTN from normal individuals. CONCLUSIONS: Radiomics can aid in the clinical diagnosis of CTN, and it is a more objective approach. It serves as a reliable neurobiological indicator for the clinical diagnosis of CTN and the assessment of changes in the trigeminal nerve in patients with CTN.

Thin Liquid Film View and Shear Stress During the Sliding of Air Bubbles on Tilted Plates.

The challenge when studying the impact and sliding of free-rising air bubbles on tilted surfaces is an experimental limitation in obtaining the film thickness of thin liquid film (TLF) during the bubbles' sliding on tilted surfaces. In this work, spatiotemporal evolution in the film thickness of the moving TLF between a sliding air bubble and a tilted plate was monitored by using a two-wavelength synchronized reflection interferometry microscopy (SRIM) technique. The evolution of the film thickness was directly determined from a timed series of monochromatic interference fringes recorded simultaneously at two different wavelengths. From the film thickness profile, a shear stress map at a given time was determined at different bubble sizes and inclination angles. Results showed that the film thickness of TLFs during the bubbles' sliding on tilted surfaces was in the range of 300-1200 nm, depending on bubble size and tilting angles. Sliding of air bubbles on tilted plates over a thin gap with a few hundred nanometers thickness yielded shear stress in the order of 10-50 Pa. Both the larger bubble size and higher tilting angles yielded a higher shear stress. Experimental results were quantitatively compared to numerical results obtained using the Reynolds lubrication theory. A good match between the two results was achieved. Numerical results suggested that a maximum shear stress exerted on a tilted plate occurred at a 25° tilting angle. This is the first time that the spatiotemporal evolution of TLF during bubbles' sliding on tilted surfaces has been achieved, and the shear stress exerted on the tilted surface has been directly determined.

The MYB transcription factor PpMYB5 regulates Pp4CL1/Pp4CL2 expression to promote lignin biosynthesis of fruit russeting in the flat nectarine.

KEY MESSAGE: Transcription factor PpMYB5 promotes lignin synthesis by directly binding to the Pp4CL1/Pp4CL2 promoter and affecting their expression, which may be related to nectarine russeting formation. Nectarine russeting is usually considered to be a non-invasive physiological disease that usually occurs on late-maturing cultivars and seriously affects their appearance quality and commercial value. The cause of nectarine fruit rust is currently unknown. In this study, we compared two flat nectarine cultivars, 'zhongyoupanweidi' (HD; russeting-free cultivar) and 'zhongyoupanweihou' (TH; russeting-prone cultivar), with respect to nectarine russeting by means of microscopy, transcriptomics, and hormone analysis. Compared to HD fruits, TH fruits had a broken cuticle, missing wax layer, and heavy lignin deposition. RNA sequencing (RNA-seq) revealed significant alternations in the expression of genes related to lignin synthesis. Moreover, structure genes Pp4CL1 and Pp4CL2, MYB transcription factor (TF) gene PpMYB5 were identified through weighted gene co-expression network analysis (WGCNA). Molecular experiments and transgenic evidence suggested that PpMYB5 regulates Pp4CL1/Pp4CL2 expression to promote lignin synthesis. Overall, in addition to providing new insights into the formation of mechanisms for nectarine russeting, our study also establishes a foundation for nectarine russeting prevention.

3D-Printed Breast Prosthesis that Smartly Senses and Targets Breast Cancer Relapse.

Breast reconstruction is essential for improving the appearance of patients after cancer surgery. Traditional breast prostheses are not appropriate for those undergoing partial resections and cannot detect and treat locoregional recurrence. Personalized shape prostheses that can smartly sense tumor relapse and deliver therapeutics are needed. A 3D-printed prosthesis that contains a therapeutic hydrogel is developed. The hydrogel, which is fabricated by crosslinking the polyvinyl alcohol with N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium, is responsive to reactive oxygen species (ROS) in the tumor microenvironment. Specifically, RSL3, a ferroptosis inducer that is loaded in hydrogels, can trigger tumor ferroptosis. Intriguingly, RSL3 encapsulated in the ROS-responsive hydrogel exerts antitumor effects by increasing the numbers of tumor-infiltrated CD4+ T cells, CD8+ T cells, and M1 macrophages while reducing the number of M2 macrophages. Therefore, this new prosthesis not only allows personalized shape reconstruction, but also detects and inhibits tumor recurrence. This combination of aesthetic appearance and therapeutic function can be very beneficial for breast cancer patients undergoing surgery.

Dictyophora indusiata polysaccharide attenuated LPS-induced intestinal inflammation of mice via the TLR4/JNK signaling pathway.

BACKGROUND: Dictyophora indusiata polysaccharide is an important bioactive component of D. indusiata, playing an important role in alleviating inflammation. The present study aimed to investigate the anti-inflammatory effect and mechanism of D. indusiata polysaccharide on lipopolysaccharide (LPS)-induced intestinal inflammation in mice. RESULTS: Our results indicated that D. indusiata polysaccharide ameliorated intestinal inflammation of mice by increasing the body weight, the number of goblet cells and decreasing inflammatory cell infiltration. In addition, D. indusiata polysaccharide significantly up-regulated expression of ZO-1, Occuldin mRNA, which were 2.55-fold and 2.28-fold higher than the LPS group, respectively. In particular, D. indusiata polysaccharide effectively inhibited the Toll-like receptor 4 (TLR4)/ c-Jun NH2-terminal kinase (JNK) signalling pathway which was 0.34-fold and 0.49-fold of gene expression and 0.41-fold and 0.39-fold of protein expression in the LPS group, respectively. CONCLUSION: The results of the present study suggested that D. indusiata polysaccharide exerted anti-inflammatory and intestinal protective effects by inhibiting the TLR4/JNK signaling pathway, which will provide a basis for the potential value of D. indusiata polysaccharide as prebiotics in food applications. © 2024 Society of Chemical Industry.

Frontiers and hotspots in anxiety disorders: A bibliometric analysis from 2004 to 2024.

Objective: This study aimed to analyze research on anxiety disorders using VOSviewer and CiteSpace to identify research hotspots and future directions. Methods: We conduct ed a comprehensive search on the Web of Science Core Collection (WoSCC) for relevant studies about anxiety disorders published within the past two decades (from 2004 to 2024). VOSviewer and CiteSpace were mainly used to analyze the authors, institutions, countries, publishing journals, reference co-citation patterns, keyword co-occurrence, keyword clustering, and other aspects to construct a knowledge atlas. Results: A total of 22,267 publications related to anxiety disorders were retrieved. The number of publications about anxiety disorders has generally increased over time, with some fluctuations. The United States emerged as the most productive country, with Harvard University identified as the most prolific institution and Brenda W. J. H. Penninx as the most prolific author in the field. Conclusion: This research identified the most influential publications, authors, journals, institutions, and countries in the field of anxiety research. Future research directions are involved advanced treatments based on pharmacotherapy, psychotherapy and digital interventions, mechanism exploration to anxiety disorders based on neurobiological and genetic basis, influence of social and environmental factors on the onset of anxiety disorders.

A Comparative Study of Methods for Calculating the Dislocation Density in GaN-on-Si Epitaxial Wafers.

A series of characterization methods involving high-resolution X-ray diffraction (HR-XRD), electron channel contrast imaging (ECCI), cathodoluminescence microscopy (CL), and atomic force microscopy (AFM) were applied to calculate the dislocation density of GaN-on-Si epitaxial wafers, and their performance was analyzed and evaluated. The ECCI technique, owing to its high lateral resolution, reveals dislocation distributions on material surfaces, which can visually characterize the dislocation density. While the CL technique is effective for low-density dislocations, it is difficult to accurately identify the number of dislocation clusters in CL images as the density increases. The AFM technique analyzes surface dislocation characteristics by detecting surface pits caused by dislocations, which are easily affected by sample and probe conditions. A prevalent method for assessing the crystal quality of GaN is the rocking curve of HR-XRD (ω-scan), which calculates the dislocation density based on the FWHM value of the curves. By comparing the above four dislocation characterization methods, the advantages and limitations of each method are clarified, which also verifies the applicability of DB=ß29b2 for GaN-on-Si epitaxial wafers. This provides an important reference value for dislocation characterization in GaN-on-Si materials. The accuracy evaluation of dislocation density can truly and reliably reflect crystal quality, which is conducive to further optimization. Furthermore, this study can also be applied to other heterogeneous or homogeneous epitaxial materials.