ObjectiveTo evaluate the antitumor activity of Periplaneta americana extract（PAE） against human-derived lung adenocarcinoma organoids（LUAD-PDOs） and to elucidate its potential mechanism based on transcriptomics. MethodsFresh tumor and adjacent normal tissues from patients with LUAD were collected to construct LUAD-PDOs and normal lung organoid（Nor-PDOs） models using 3D organoid culture technology. The effective intervention concentration of PAE was determined using the cell counting kit-8（CCK-8） assay. Experimental groups included the model group（LUAD-PDOs）， normal group， model administration group（LUAD-PDOs+PAE）， and normal administration group（Nor-PDOs+PAE）. Hematoxylin-eosin（HE） staining was used to observe the pathological structures of PDOs， immunohistochemistry（IHC） was performed to detect the expressions of the proliferation marker Ki-67 and lung adenocarcinoma differentiation markers cytokeratin-7（CK-7） and Napsin A， TUNEL staining was applied to detect cell apoptosis. RNA sequencing（RNA-Seq） was conducted to identify differentially expressed genes（DEGs）， followed by Gene Ontology（GO）， Kyoto Encyclopedia of Genes and Genomes（KEGG）， and Gene Set Enrichment Analysis（GSEA）， alongside protein-protein interaction（PPI） network analysis to screen core mechanisms. Finally， key targets were validated by integrating external database analysis with immunofluorescence（IF）. ResultsNor-PDOs and LUAD-PDOs that highly recapitulated the pathological characteristics of the primary tissues were successfully established. The CCK-8 assay determined that the effective intervention concentration of PAE was 16 g·L^-1. Morphological observation showed that Nor-PDOs exhibited lumen-forming structures， whereas LUAD-PDOs displayed dense， solid structures. CCK-8 and TUNEL assays revealed that， compared with the model group， PAE intervention inhibited the proliferation of LUAD-PDOs and promoted apoptosis in LUAD cells， while showing no significant effect on the viability of Nor-PDOs. Transcriptomic analysis identified 719 DEGs that were significantly reversed after PAE intervention（347 up-regulated and 372 down-regulated）（P<0.05）. GO enrichment analysis indicated that DEGs in the model administration group were significantly enriched in biological processes related to cell cycle regulation compared to the model group. KEGG pathway analysis revealed that PAE affected pathways related to proliferation and metabolism， including pathways in cancer and the p53 signaling pathway. GSEA further confirmed that PAE significantly enhanced the activity of the p53 signaling pathway（P<0.05）. PPI network analysis indicated that breast cancer type 1 susceptibility protein（BRCA1） and checkpoint kinase 1（CHEK1） were the core down-regulated targets in the p53 pathway. IF verified the high expression of BRCA1 and CHEK1 in LUAD-PDOs and their significant downregulation after PAE intervention（P<0.05）. Furthermore， survival analysis based on The Cancer Genome Atlas（TCGA） database indicated that low expression of BRCA1 and CHEK1 was significantly associated with prolonged overall survival in patients with LUAD（P<0.05）. ConclusionPAE effectively inhibits proliferation of LUAD-PDOs and promotes their apoptosis， its anti-tumor mechanism is potentially associated with the activation of the p53 signaling pathway， with BRCA1 and CHEK1 genes likely serving as key downstream targets for the effects of PAE.

Based on LI Gao's Academic Thought， focusing on the process of qi transformation and taking the regulation and restoration of metabolism and immunity as the entry point， a "source-pivot-convergence" diagnostic and therapeutic model for malignant tumors is constructed. In this model， spleen and stomach internal injury is the source of malignant tumor occurrence， while the disorder of ascending and descending is the pivot of the disease development， and the generation of yin fire is the convergence of malignant tumor progression. Based on this， the three major therapeutic methods of clearing the source， harmonizing the pivot， and resolving the convergence are established. To fortify spleen and boost qi， consolidate the root and clear the source， modified Buzhong Yiqi Decoction（补中益气汤）can be used. To raise the clear and direct the turbid downward， regulate qi and harmonize the pivot， modified Shengyang Yiwei Decoction （升阳益胃汤） is suggested. To restore balance and promote circulation， disperse accumulation and resolve convergence， modified Shengyang Sanhuo Decoction （升阳散火汤） is selected. In clinical practice， these formulas can be used in combination according to the complexity of the pathogenesis， and further adapted with prescriptions for promoting dispersion and penetrating pathogenic factors， resolving phlegm and promoting circulation， activating blood and eliminating concretions， which can provide a reference for the prevention and treatment of tumor diseases.

Based on LI Gao's Academic Thought， focusing on the process of qi transformation and taking the regulation and restoration of metabolism and immunity as the entry point， a "source-pivot-convergence" diagnostic and therapeutic model for malignant tumors is constructed. In this model， spleen and stomach internal injury is the source of malignant tumor occurrence， while the disorder of ascending and descending is the pivot of the disease development， and the generation of yin fire is the convergence of malignant tumor progression. Based on this， the three major therapeutic methods of clearing the source， harmonizing the pivot， and resolving the convergence are established. To fortify spleen and boost qi， consolidate the root and clear the source， modified Buzhong Yiqi Decoction（补中益气汤）can be used. To raise the clear and direct the turbid downward， regulate qi and harmonize the pivot， modified Shengyang Yiwei Decoction （升阳益胃汤） is suggested. To restore balance and promote circulation， disperse accumulation and resolve convergence， modified Shengyang Sanhuo Decoction （升阳散火汤） is selected. In clinical practice， these formulas can be used in combination according to the complexity of the pathogenesis， and further adapted with prescriptions for promoting dispersion and penetrating pathogenic factors， resolving phlegm and promoting circulation， activating blood and eliminating concretions， which can provide a reference for the prevention and treatment of tumor diseases.

ObjectiveThis study aimed to investigate the optimal compatibility ratio of the Chuanxiong Rhizoma-Carthami Flos （CR-CF） couplet medicines in ischemic stroke （IS） therapy and its pharmacological action mechanism， providing a scientific basis for the clinical application of CR-CF couplet medicines in IS therapy. MethodsThe chemical composition of CR-CF was analyzed using liquid chromatography mass spectrometry （LC-MS/MS）. The contents of eight characteristic chemical components in aqueous extracts of CR-CF with common clinical compatibility ratios （1∶1， 1∶2， 1∶3， 3∶2， 2∶1） were determined by ultra-high performance liquid chromatography（UHPLC）. An oxygen-glucose deprivation/reoxygenation （OGD/R）-induced mouse hippocampal neuron HT22 cell injury model was established， and cells were treated with different CR-CF compatibility ratios. The collaborative index （CI） was calculated by using CompuSyn software. A cerebral artery occlusion/reperfusion （MCAO/R） model of rats was induced by using the modified Longa suture method. The rats were divided into the sham group， model group， Chuanxiong Rhizoma （CR） group （1.3 g·kg^-1）， Carthami Flos （CF） group （3.9 g·kg^-1）， CR-CF group （5.2 g·kg^-1）， and edaravone group （5 mg·kg^-1）. Neuronal defect scores were assessed by the Longa scoring method. Cerebral infarction volume was measured by 2，3，5-triphenyltetrazolium chloride（TTC） staining. Neuronal damage was observed via hematoxylin-eosin （HE） staining. Neuronal apoptosis of rats was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） staining， and the expression of apoptosis-related proteins was analyzed by Western blot. Label-free proteomics was employed to screen differentially expressed proteins， and Western blot was used to examine the expression of phosphatidylinositol 3-kinase/protein kinase B（PI3K/Akt） signaling pathway-related proteins. Finally， molecular docking was performed to predict the binding affinity of eight active constituents in CR-CF （1∶3） with PI3K. ResultsWhen CR-CF was combined at a 1∶3 ratio， the total content of the eight active constituents in the extract was the highest， and the synergistic protective effect on OGD/R-injured HT22 cells was the strongest （CI=0.308）. Animal experiments showed that compared with the sham group， the model group exhibited increased neuroecological score points （P<0.01）， larger cerebral infarction volumes （P<0.01）， aggravated brain tissue damage， elevated neuronal apoptosis （P<0.01）， and increased B-cell lymphoma-2（Bcl-2）-associated X protein （Bax）/Bcl-2 and cleaved Cysteinyl aspartate specific proteinase-3/Cysteinyl aspartate specific proteinase-3 （cleaved Caspase-3/Caspase-3） ratios （P<0.01）. Compared with the model group， CR-CF （1∶3） significantly reduced neurological scores （P<0.01）， significantly decreased cerebral infarction volume （P<0.01）， alleviated brain tissue damage， inhibited neuronal apoptosis （P<0.01）， and significantly lowered the Bax/Bcl-2 and cleaved Caspase-3/Caspase-3 ratios （P<0.01）. The therapeutic effect of CR-CF （1∶3） was superior to that of CR or CF alone. Proteomic analysis revealed that CR-CF （1∶3） activated the PI3K/Akt signaling pathway. Validation experiments demonstrated that compared with the sham group， the model group showed obviously reduced p-PI3K/PI3K and p-Akt/Akt （P<0.05）. Compared with the model group， p-PI3K/PI3K and p-Akt/Akt ratios （P<0.05） obviously increased. Compared with the CR-CF group， the 2-（4-morpholinyl）-8-phenyl-4H-1-benzopyran-4-one LY294002 inhibitor+CR-CF group exhibited obviously decreased p-PI3K/PI3K and p-Akt/Akt （P<0.05）. Molecular docking results indicated that the active constituents of CR-CF （1∶3） had strong binding affinity with PI3K. ConclusionThe CR-CF couplet medicines at a 1∶3 ratio exhibit optimal synergistic effects， and their anti-IS mechanism is closely related to activation of the PI3K/Akt signaling pathway and inhibition of neuronal apoptosis.

ObjectiveTo investigate the status of overlapping hepatitis B virus （HBV） infection in patients with chronic hepatitis C virus （HCV） infection and the serological characteristics of such patients. MethodsA total of 8 637 patients with HCV infection who were hospitalized from January 1， 2010 to December 31， 2020 and had complete data of HBV serological markers were enrolled， and the composition ratio of patients with overlapping HBV serological markers was analyzed among the patients with HCV infection. The patients were divided into groups based on age and year of birth， and serological characteristics were analyzed， and the distribution of HBV-related serological characteristics were analyzed across different HCV genotypes. ResultsThe patients with HCV/HBV overlapping infection accounted for 5.85%， and the patients with previous HBV infection accounted for 48.10%； the patients with protective immunity against HBV accounted for 14.67%， while the patients with a lack of protective immunity against HBV accounted for 31.39%. The patients were divided into groups based on age： in the 0 — 17 years group， the patients with protective immunity against HBV accounted for 61.41% （304 patients）； the 18 — 44 years group was mainly composed of patients with previous HBV infection （698 patients， 37.31%）， the 45 — 59 years group was predominantly composed of patients with previous HBV infection （1 945 patients， 50.38%）， and the ≥60 years group was also predominantly composed of patients with previous HBV infection （1 486 patients， 61.66%）. The patients were divided into groups based on the year of birth： in the pre-1992 group， the patients with previous HBV infection accounted for 51.63% （4 112 patients）； in the 1992 — 2005 group， the patients with protective immunity against HBV accounted for 54.72% （168 patients）； in the post-2005 group， the patients with protective immunity against HBV accounted for 64.38% （235 patients）. In this study， 6 301 patients underwent HCV genotype testing： the patients with genotype 1b accounted for the highest proportion of 51.71% （3 258 patients）， followed by those with genotype 2a （1 769 patients， 28.07%）， genotype 3b （63 patients， 1.00%）， genotype 3a （10 patients， 0.16%）， genotype 4 （21 patients， 0.33%）， and genotype 6a （5 patients， 0.08%）. ConclusionWith the implementation of hepatitis B planned vaccination program in China， there has been a significant reduction in the proportion of patients with previous HBV infection among the patients with HCV/HBV overlapping infection， but there is still a relatively high proportion of patients with a lack of protective immunity against HBV.

ObjectiveTo investigate the effect of Tougu Xiaotong capsules （TGXTC） on the regulation of chondrocyte PANoptosis， delay of chondrocyte degeneration， and improvement of the symptoms in knee osteoarthritis （KOA）. MethodsIn vivo experiments： 50 male C57BL/6 mice were randomly assigned into five groups （n=10 per group）： sham operation group， model group， low-dose TGXTC group （7.2 g·kg^-1）， high-dose TGXTC group （14.4 g·kg^-1）， and diclofenac sodium group （0.05 g·kg^-1）. Except for the sham group， KOA models were established in all other groups using the modified Hulth method. Following successful model induction， the TGXTC groups received daily oral gavage of 7.2 or 14.4 g·kg^-1 for 6 weeks， while the diclofenac sodium group received 0.05 g·kg^-1 solution daily over the same duration. Model evaluation was performed using Lequesne MG score； micro-computed tomography （micro-CT） was used to scan the knee， hematoxylin-eosin （HE） staining and safranin O-fast green staining were used to observe the morphology of cartilage， transmission electron microscopy （TEM） was used to determine ultrastructural changes of PANoptosis. Multiple immunofluorescence （IF） co-localization assays was performed to detect the co-localization of cleaved Caspase-3， receptor-interacting protein 3 （RlPK3）， and the N-terminal domain of gasdermin D （GSDMD-N） in cartilage tissue， while western blot was employed to detect the expression levels of cleaved Caspase-3， RIPK3， and GSDMD-N. In vitro experiments： The knee cartilages of 4-week-old SD rats were isolated， and a chondrocyte in vitro culture system was established through mechanical digestion with 0.2% type Ⅱ collagenase. Second-generation chondrocytes were divided into three groups： the control group， the model group （pretreated with 10 mg·L^-1 lipopolysaccharide （LPS） for 24 h followed by treatment with 1 μmol·L^-1 nigericin for 4 h）， and the TGXTC treatment group （pretreated with 10 mg·L^-1 LPS for 24 h， followed by exposure to 1 μmol·L^-1 nigericin for 4 h and subsequently treated with 100 mg·L^-1 TGXTC for an additional 24 h）. The levels of reactive oxygen species （ROS）， apoptosis， necroptosis， and pyroptosis of chondrocytes were evaluated via fluorescence microscopy following staining with ROS detection， AO/EB and YO-PRO-1/PI staining kits. Transmission electron microscopy was utilized to investigate the ultrastructural changes associated with PANoptosis in cartilage tissue of KOA mice. Inflammatory cytokine levels （IL-1β and IL-18） were measured using ELISA. Western blot was conducted to assess protein expressions related to PANoptosis， including cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3. ResultsCompared with the sham group， the Lequesne MG scores were significantly up-regulated（P<0.01） in the model group， and the pathological changes of cartilage were significantly， with joint spaces narrower， osteophyte formation increased， secere abrasion of cartilage surface. Ultrastructural analysis revealed pronounced chondrocyte apoptosis， necroptosis， and pyroptosis， along with markedly elevated expression of cleaved Caspase-3， RlPK3， and GSDMD-N in cartilage tissue （P<0.01）. In addition， The mean fluorescence intensities of ROS， orange-red fluorescence in AO/EB staining， green fluorescence and red fluorescence in YO-PRO-1/PI staining were increased of chondrocyte in the model group （P<0.01） . The levels of inflammatory factors IL-1β and IL-18 in the supernatant were increased （P<0.01）. The expression of PANoptosis related proteins （cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3） were also significantly upregulated（P<0.05）. Compared to the model group， the TGXTC group demonstrated a significant improvement in various parameters of mice. These included a reduction in the Lequesne MG score， an increase in joint space， a decrease in osteophyte formation， diminished cartilage damage， reduced release of ROS， and alleviation of apoptotic， necroptotic， and pyroptotic processes in chondrocytes. Additionally， mitochondrial swelling and endoplasmic reticulum dilation were also mitigated. The levels of ROS as well as IL-1β and IL-18 were significantly decreased （P<0.05）. Furthermore， the expression levels of proteins associated with PANoptosis in cartilage tissue showed marked reductions （P<0.05）. Similar results were observed in chondrocytes： cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3 exhibited significant decreases as well （P<0.05）. ConclusionTGXTC may mitigate chondrocytes degeneration and alleviate KOA symptoms by reducing oxidative stress and suppressing the activation of PANoptosis pathways.

ObjectiveTo investigate the effect of Tougu Xiaotong capsules （TGXTC） on the regulation of chondrocyte PANoptosis， delay of chondrocyte degeneration， and improvement of the symptoms in knee osteoarthritis （KOA）. MethodsIn vivo experiments： 50 male C57BL/6 mice were randomly assigned into five groups （n=10 per group）： sham operation group， model group， low-dose TGXTC group （7.2 g·kg^-1）， high-dose TGXTC group （14.4 g·kg^-1）， and diclofenac sodium group （0.05 g·kg^-1）. Except for the sham group， KOA models were established in all other groups using the modified Hulth method. Following successful model induction， the TGXTC groups received daily oral gavage of 7.2 or 14.4 g·kg^-1 for 6 weeks， while the diclofenac sodium group received 0.05 g·kg^-1 solution daily over the same duration. Model evaluation was performed using Lequesne MG score； micro-computed tomography （micro-CT） was used to scan the knee， hematoxylin-eosin （HE） staining and safranin O-fast green staining were used to observe the morphology of cartilage， transmission electron microscopy （TEM） was used to determine ultrastructural changes of PANoptosis. Multiple immunofluorescence （IF） co-localization assays was performed to detect the co-localization of cleaved Caspase-3， receptor-interacting protein 3 （RlPK3）， and the N-terminal domain of gasdermin D （GSDMD-N） in cartilage tissue， while western blot was employed to detect the expression levels of cleaved Caspase-3， RIPK3， and GSDMD-N. In vitro experiments： The knee cartilages of 4-week-old SD rats were isolated， and a chondrocyte in vitro culture system was established through mechanical digestion with 0.2% type Ⅱ collagenase. Second-generation chondrocytes were divided into three groups： the control group， the model group （pretreated with 10 mg·L^-1 lipopolysaccharide （LPS） for 24 h followed by treatment with 1 μmol·L^-1 nigericin for 4 h）， and the TGXTC treatment group （pretreated with 10 mg·L^-1 LPS for 24 h， followed by exposure to 1 μmol·L^-1 nigericin for 4 h and subsequently treated with 100 mg·L^-1 TGXTC for an additional 24 h）. The levels of reactive oxygen species （ROS）， apoptosis， necroptosis， and pyroptosis of chondrocytes were evaluated via fluorescence microscopy following staining with ROS detection， AO/EB and YO-PRO-1/PI staining kits. Transmission electron microscopy was utilized to investigate the ultrastructural changes associated with PANoptosis in cartilage tissue of KOA mice. Inflammatory cytokine levels （IL-1β and IL-18） were measured using ELISA. Western blot was conducted to assess protein expressions related to PANoptosis， including cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3. ResultsCompared with the sham group， the Lequesne MG scores were significantly up-regulated（P<0.01） in the model group， and the pathological changes of cartilage were significantly， with joint spaces narrower， osteophyte formation increased， secere abrasion of cartilage surface. Ultrastructural analysis revealed pronounced chondrocyte apoptosis， necroptosis， and pyroptosis， along with markedly elevated expression of cleaved Caspase-3， RlPK3， and GSDMD-N in cartilage tissue （P<0.01）. In addition， The mean fluorescence intensities of ROS， orange-red fluorescence in AO/EB staining， green fluorescence and red fluorescence in YO-PRO-1/PI staining were increased of chondrocyte in the model group （P<0.01） . The levels of inflammatory factors IL-1β and IL-18 in the supernatant were increased （P<0.01）. The expression of PANoptosis related proteins （cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3） were also significantly upregulated（P<0.05）. Compared to the model group， the TGXTC group demonstrated a significant improvement in various parameters of mice. These included a reduction in the Lequesne MG score， an increase in joint space， a decrease in osteophyte formation， diminished cartilage damage， reduced release of ROS， and alleviation of apoptotic， necroptotic， and pyroptotic processes in chondrocytes. Additionally， mitochondrial swelling and endoplasmic reticulum dilation were also mitigated. The levels of ROS as well as IL-1β and IL-18 were significantly decreased （P<0.05）. Furthermore， the expression levels of proteins associated with PANoptosis in cartilage tissue showed marked reductions （P<0.05）. Similar results were observed in chondrocytes： cleaved Caspase-3， cleaved Caspase-8， RIPK3， ZBP1， GSDMD-N， and NLRP3 exhibited significant decreases as well （P<0.05）. ConclusionTGXTC may mitigate chondrocytes degeneration and alleviate KOA symptoms by reducing oxidative stress and suppressing the activation of PANoptosis pathways.

Objective To investigate the feasibility, safety, and clinical value of endoscopic-assisted skin-sparing mastectomy combined with immediate implant-based breast reconstruction performed as day surgery for breast cancer, aiming to provide a reference for major hospitals seeking to implement a day surgery model for breast cancer treatment. Methods We retrospectively analyzed the patients who underwent endoscopic-assisted skin-sparing mastectomy combined with immediate implant-based breast reconstruction for breast cancer at West China Hospital of Sichuan University from June 2021 to December 2022, and they were divided into a day surgery group and a conventional inpatient group based on their admission model. The operative indicators, Breast-Q scores, preoperative waiting time, length of hospital stay, hospitalization costs and complications of the two groups were analyzed. Results Except for intraoperative bleeding (P=0.007), the difference between the two groups in comparison of the rest of the operative indicators was not statistically significant (all P>0.05); there was no significant difference between the two groups in preoperative and postoperative Breast-Q scores (all P>0.05); the preoperative waiting time and length of stay in hospital of the day surgery group were 4.0 (3.0, 11.0) days and 1.0 (1.0, 1.0) days, respectively, which were significantly shorter than that of the conventional inpatient group; the postoperative pain score in the day surgery group [1.0 (1.0, 1.0) points] was lower than that in the conventional inpatient group [3.0 (3.0, 3.0) points], with a statistically significant difference between the two groups (P<0.001). Additionally, the total hospitalization costs for the day surgery group and conventional inpatient group were 50 656.5 (48 145.3, 62 597.3) RMB and 53 689.3 (50 469.1, 64 826.5) RMB, respectively.The total hospitalization cost in the day surgery group was significantly lower than that in the conventional inpatient group, with a statistically significant difference between the two groups (P=0.001). There was no statistically significant difference in complications between the two groups (all P>0.05). Conclusion Endoscopic-assisted skin-sparing mastectomy combined with immediate implant-based breast reconstruction in day surgery is feasible and safe. Without increasing postoperative complications, it effectively reduces hospitalization costs and shortens medical care time, demonstrating significant clinical value.

Background: and Purpose Live cell-based assays (LCBA) are increasingly used for serological antibody detection due to their ability to preserve antigen conformation, offering moderately higher sensitivity than fixed cell-based assays. However, the clinical necessity of prioritizing LCBA for the detection of aquaporin-4 immunoglobulin G (AQP4-IgG) in neuromyelitis optica spectrum disorder (NMOSD) remains unclear, especially when compared to its established role in diagnosing myelin oligodendrocyte glycoprotein antibody-associated disease. Methods: We compared the performance of live cell-based assays using immunofluorescence (LCBA-IF) and fixed cell-based assays using immunofluorescence (FCBA-IF) in detecting AQP4-IgG in 90 cases of NMOSD meeting 2015 International Panel for Neuromyelitis Optica Diagnosis criteria, alongside 40 controls. Additionally, we further investigated the relationship between AQP4-IgG titers as measured by LCBA-IF and FCBA-IF and clinical parameters in NMOSD patients. Results: Results showed 96.9% agreement between LCBA-IF and FCBA-IF (Cohen’s κ=0.935), with a strong Spearman correlation (0.977, p<0.001). Both methods demonstrated 100% specificity, with LCBA-IF showing slightly higher sensitivity compared to FCBA-IF. Within LCBAIF-tested groups, statistically significant differences in annualized relapse rates were observed across all pairwise comparisons (low-titer vs. moderate-titer, low-titer vs. high-titer, and moderate-titer vs. high-titer; all p<0.050). However, this association reached statistical significance in some FCBA-IF-tested groups. Conclusions Overall, there is a strong concordance between LCBA-IF and FCBA-IF in detecting AQP4-IgG, where LCBA-IF shows slightly higher sensitivity. Furthermore, there is a potential link between elevated AQP4-IgG titers and an increased risk of relapse, and this correlation may appear more pronounced when using LCBA-IF.

Objective: To compare the effects of immediate versus delayed post-space preparation on the bond strength of fiber posts and the fracture resistance of roots after root canal obturation using iRoot SP and the single-cone technique, and to provide an experimental basis for the selection of the timing of clinical post-space preparation. Methods: This study was approved by the Medical Ethics Committee of the institution, and written informed consent was obtained from all participants. Seventy-two extracted human single-rooted premolars were randomly divided into two groups (n = 36 each): the immediate post-space preparation group (post-space preparation performed immediately after root canal obturation) and the delayed post-space preparation group (post-space preparation performed 1 week after root canal obturation). Cleanliness of the root canal walls was assessed with a dental microscope after preparation in both groups; the ultrastructural characteristics of the dentinal surface were examined via scanning electron microscopy; the fracture resistance of roots was measured with root fracture resistance tests; the bond strength of the fiber posts was measured with the thin-slice push-out test; and the bond failure modes were observed and analyzed under a stereomicroscope. Results: Under dental microscopy, the dentin surface of the immediate post-space preparation group appeared cleaner than that of the delayed post-space preparation group. Scanning electron microscopy revealed that most dentinal tubules remained open in the immediate post-space preparation group, while the tubules in the delayed post-space preparation group showed incomplete patency. The fracture resistance of the immediate post-space preparation group was (2 872 ± 241.5) N and that of the delayed post-space preparation group was (2 934 ± 353.1) N, with no statistically significant difference (t = -0.328, P = 0.751). The push-out bond strength of the immediate post-space preparation group (10.310 ± 2.907) MPa was significantly higher than that of the delayed post-space preparation group (7.917 ± 2.429) MPa, with a statistically significant difference (t = 4.457, P < 0.001). Analysis of failure modes showed that adhesive-to-dental interface failure was the predominant mode in both groups. Conclusion Following root canal obturation with iRoot SP using the single-cone technique, immediate post-space preparation yields superior fiber post bond strength compared to delayed post-space preparation, without compromising root fracture resistance.