OBJECTIVES: To characterize the biological properties of double-negative T (DNT) cells isolated from leukoreduction filter residues. METHODS: Leukoreduction filters containing residues from 400 mL whole blood units (n=6) were collected from a blood center. Filters were back-flushed with normal saline, and the eluate was concentrated to obtain leukoreduction filter residues. Leukocytes in the residues were counted by dual-fluorescence staining. DNT cells were then isolated from the residues using antibody-mediated adsorption and density gradient centrifugation. Both cryopreserved and fresh unstimulated DNT cells derived from the residues were subjected to in vitro culture. Following culture, cells were assessed for expansion fold, viability, immunophenotype, differentiation status, and cytotoxicity against target cells using dual-fluorescence staining and flow cytometry, with comparisons made to DNT cells derived from whole blood. RESULTS: The leukocyte recovery rate achieved through reverse flushing of the leukocyte reduction filter was (41.9±14.7)%. Compared to whole blood, the DNT cell starting material obtained from filter residues showed no significant difference in total T-cell content (P>0.05). However, the viability and purity of the resulting DNT cell starting materials were significantly lower (both P<0.05). After 17 days of culture, DNT cells from filter residues and whole blood showed no significant differences in expansion fold, immunophenotype, differentiation status, or cytotoxicity toward target cells (all P>0.05). However, the viability of DNT cells from residues was significantly lower than that of whole blood-derived DNT cells [(86.0±4.2)% vs. (92.2±1.2)%, P<0.05]. After thawing (post 3 or 15 days of cryopreservation) and 17 days of culture, DNT cell starting materials from residues showed comparable immunophenotype, expansion fold, and differentiation status to their non-cryopreserved counterparts from the same source (all P>0.05). However, the viability of DNT cells cryopreserved for 3 days [92.4% (91.8%, 92.8%)] and the cytotoxicity against target cells of those cryopreserved for 15 days [91.3% (89.4%, 95.1%)] were significantly higher than those of non-cryopreserved DNT cells [87.8% (82.0%, 89.0%) and 70.9% (67.3%, 80.2%), respectively] (P<0.05). CONCLUSIONS DNT cells derived from leukoreduction filter residues exhibited highly comparable characteristics to those from whole blood in terms of expansion, purity, differentiation, and biological potency. Furthermore, their biological activity post-cryopreservation and revival remained largely similar to non-cryopreserved cells. These findings suggest that leukoreduction filter residues represent a promising alternative source of starting material for manufacturing off-the-shelf, allogeneic DNT cell therapeutics.

Metformin has been demonstrated to attenuate hyperglycaemia by modulating the gut microbiota. However, the mechanisms through which the microbiome mediates metformin monotherapy failure (MMF) are unclear. Herein, in a prospective clinical cohort study of newly diagnosed type 2 diabetes mellitus (T2DM) patients treated with metformin monotherapy, metagenomic sequencing of faecal samples revealed that Phocaeicola vulgatus abundance was approximately 12 times higher in nonresponders than in responders. P. vulgatus rapidly hydrolysed taurine-conjugated bile acids, leading to ceramide accumulation and reversing the improvements in glucose intolerance conferred by metformin in high-fat diet-fed mice. Interestingly, C22:0 ceramide bound to mitochondrial fission factor to induce mitochondrial fragmentation and impair hepatic oxidative phosphorylation in P. vulgatus-colonized hyperglycaemic mice, which could be exacerbated by metformin. This work suggests that metformin may be unsuitable for P. vulgatus-rich T2DM patients and that clinicians should be aware of metformin toxicity to mitochondria. Suppressing P. vulgatus growth with cefaclor or improving mitochondrial function using adenosylcobalamin may represent simple, safe, effective therapeutic strategies for addressing MMF.

Although a single nucleotide polymorphism for N-acetyltransferase 10 (NAT10) has been identified in patients with early-onset stroke, the role of NAT10 in ischemic injury and the related underlying mechanisms remains elusive. Here, we provide evidence that NAT10, the only known RNA N4-acetylcytidine (ac4C) modification "writer", is increased in the damaged cortex of patients with acute ischemic stroke and the peri-infarct cortex of mice subjected to photothrombotic (PT) stroke. Pharmacological inhibition of NAT10 with remodelin on Days 3-7 post-stroke or astrocytic depletion of NAT10 via targeted virus attenuates ischemia-induced infarction and improves functional recovery in PT mice. Mechanistically, NAT10 enhances ac4C acetylation of the inflammatory cytokine tissue inhibitor of metalloproteinase 1 (Timp1) mRNA transcript, which increases TIMP1 expression and results in the accumulation of microtubule-associated protein 1 light chain 3 (LC3) and progression of astrocyte autophagy. These findings demonstrate that NAT10 regulates astrocyte autophagy by targeting Timp1 ac4C after stroke. This study highlights the critical role of ac4C in the regulation of astrocyte autophagy and proposes a promising strategy to improve post-stroke outcomes via NAT10 inhibition.

Objective: To identify an optimal back-flush solution for leukocyte-depleted filters that maximizes peripheral blood mononuclear cell (PBMC) recovery with high viability, long-term storage stability, and sterility of the harvested residues, thereby providing a clinically translatable strategy. Methods: Three sterile bag-packaged solutions—Saline, Solvent, and Hanks' balanced salt solution (HBSS)—were used to back-flush randomly assigned leukocyte-depleted filters. Nucleated cell recovery rate and viability of the harvested residues were compared. The optimal solution identified was applied to an expanded sample set. PBMC viability and yield were evaluated after 1h vs 48h storage of the residues. PBMCs isolated from the residues were cryopreserved in liquid nitrogen for 1 month, followed by post-thaw comparisons of viability and T-cell expansion capacity. Results: The Solvent group achieved the highest and most consistent nucleated cell recovery rate. Post-flush recovery rate from filters after 400 mL whole blood processing was (21.3±1.6)% for the Solvent group, significantly higher than Saline group (19.2±6.3)% and HBSS group (11.2±5.0)%, with residues from all groups maintaining viability >90%. No biologically significant difference in residue viability was observed between 48h vs 1h storage groups (93.3±2.3)% vs (95.7±1.8)%). PBMC recovery rates from residues showed no statistical difference between 48h vs 1h storage groups [(48.2%±9.5%)vs (40.41%±8.35%), P>0.05], with (17.7±2.6)×10 cells. After 1-month cryopreservation and 10-day expansion, PBMCs isolated from 48-hour-stored residues retained (91.2±3.2)% viability and achieved a (61.9±15.9)-fold expansion. Conclusion: The bag-packaged Solvent, as a back-flush solution, enables sterile acquisition of leukocyte-depleted filter residues through closed-system tubing connections. These residues maintained PBMC viability and recovery rates after 48h storage at 2℃-8℃, with post-cryopreservation (1-month liquid nitrogen) viability and expansion capacity remaining stable. This protocol complies with blood bank regulatory criteria, addresses the concerns about the infectious window period in cell therapy raw materials, and provides a clinically translatable strategy for PBMC-based applications.

Objective:To compare the efficacy of Ilizarov ring external fixation and unilateral rail external fixation in the treatment of infected bone defects following surgery for tibial fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 50 patients with infected bone defects after surgery for tibial fractures, who were admitted to the 940th Hospital of the Joint Logistics Support Force of the PLA from August 2019 to November 2021, including 37 males and 13 females, aged 19-59 years [(42.2±8.8)years]. After debridement and osteotomy, 28 patients were treated with Ilizarov ring external fixation (Ilizarov group) and 22 with unilateral rail external fixation (unilateral fixation group). All the patients in the two groups had previously undergone internal fixation with plates or Kirschner wires for tibial fracture before bone transport. Bone transport started at one week for three stages after successful infection control and osteotomy and was conducted. The following parameters were compared between the two groups: frame-wearing time and healing index after bone transport, self-rating anxiety scale (SAS) grade at 6 months after bone transport, Paley score and Association for the Study and Application of the Method of Ilizarov (ASAMI) score at the last follow-up, Hospital for Special Surgery (HSS) knee score and Baird-Jackson ankle score on admission, after external fixator removal and at the last follow-up, and incidence of postoperative complications.Results:All the patients were followed up for 28-36 months [(32.5±1.6)months]. There were no significant differences in frame-wearing time or healing index between the two groups after bone transport ( P>0.05). At 6 months after bone transport, the SAS grade in the unilateral fixation group (13 patients with mild anxiety, 8 with moderate anxiety, and 1 with severe anxiety) was better than that in the Ilizarov group (6 patients with mild anxiety, 19 with moderate anxiety, 3 with severe anxiety) ( P<0.01). No significant differences were found in the Paley score or ASAMI score between the two groups at the last follow-up ( P>0.05). There were no significant differences in HSS knee score or Baird-Jackson ankle score between the two groups on admission, after external fixator removal or at the last follow-up ( P>0.05). No significant differences were observed in the incidence of pin tract infection, poor healing, infection in the bone elongation area, or re-fracture between the two groups ( P>0.05). The incidence of postoperative axial deviation was 0 in the Ilizarov group, lower than 18% in the unilateral fixation group (4/22) ( P<0.05). Conclusion:Although Ilizarov ring external fixation and unilateral rail external fixation demonstrate comparable efficacy in the treatment of infected bone defects after surgery for tibial fractures, the former provides superior mechanical stability and postoperative axial deviation correction, while the latter offers advantages in reducing psychological burden and enhancing treatment tolerance.

Objective:To investigate the effect of the sizes of osteon-like concentric microgroove structures on the osteoclastic differentiation of macrophages on titanium surfaces, and to provide reference for the surface modification of implants.Methods:The silicon wafers sputtered with titanium were selected as the control group (smooth surface specimens) and four concentric groups (concentric circles with the maximum diameter of 200 μm, the minimum diameter of 20 μ m, the spacing of concentric circles of 10 or 30 μm, the width of microgrooves of 10 or 30 μm, and the depth of microgrooves of 5 or 10 μm) specimens (the total sample size in each group was 27). The width of microgrooves of C10-5 and C10-10 groups was 10 μm, the depth was 5 and 10 μm, and the width of microgrooves of C30-5 and C30-10 groups was 30 μ m, the depth was 5 and 10 μ m, respectively. The physicochemical properties of the material surfaces were characterized using scanning electron microscopy and contact-angle measurement. The proliferation, adhesion of macrophage-like cell line RAW264.7 and the formation of osteoclast actin-rings on the specimen surfaces were observed by cell counting kit-8 (CCK-8), immunofluorescence staining and laser confocal microscopy. Tartrate resistant acid phosphatase (TRAP) quantitative detection, real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to investigate the regulation of osteon-like concentric microgroove structures on the specimen surfaces on the osteoclastic differentiation of macrophages.Results:Macrophages aggregated and grew disorderly on the surface of the smooth group, and arranged in concentric circles along the microgroove structures on the surfaces of the concentric groups. After 5 days of culture, the cell proliferation of C30 groups (the A values of C30-5 group and C30-10 group were 1.335±0.018 and 1.340±0.033, respectively) was significantly higher than that of C10 groups (the A values of C10-5 group and C10-10 group were 0.967±0.015 and 1.182±0.020, respectively)(all P<0.05). The cell proliferation of the four concentric groups was significantly higher than that of the control group (the A value was 0.796±0.012), with statistical significance (all P<0.05). After osteoclastic induction for 5 days the osteoclasts induced in the C10-5 and C10-10 groups exhibited smaller actin rings and fewer numbers. The TRAP activity in each concentric group was significantly lower than that in the control group ( P<0.05). The expression levels of osteoclast differentiation-related genes TRAP (0.610±0.022) in the C10-10 group was lowest, and CtsK (0.489±0.136, 0.445±0.037) in the C10-5 and C10-10 groups were lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05), the expression levels of osteoclast differentiation-related proteins TRAP (0.648±0.041), MMP-9 (0.688±0.026) in the C10-10 group were lowest, and CtsK (0.491±0.016, 0.453±0.010) in the C10-10 and C30-10 groups were also lower compared to the smooth group and other concentric groups, with statistical significance (all P<0.05). Conclusions:The osteon-like concentric microgroove structures inhibit the osteoclastic differentiation of macrophage-like cell line RAW264.7, with the microgrooves 10 μm wide and 10 μm deep showing the most significant inhibitory effect on the osteoclastic differentiation.

Objective:To compare and analyze the similarities and differences in clinical manifestations, laboratory findings, pathological characteristics, and prognosis between urticarial vasculitis (UV) and chronic spontaneous urticaria with pigmentation (CSUwp) .Methods:A retrospective analysis was conducted on the clinical data and follow-up results from 35 UV patients and 54 CSUwp patients who attended the Department of Dermatology, Southwest Hospital, Army Medical University from 2014 to 2024. The clinical characteristics (duration of rash, pigmentation, petechiae and ecchymosis, itching, burning sensation, fever, fatigue, skin lesion characteristics, etc.) , laboratory test results, pathological features, and prognosis were compared between the two groups. Statistical analysis was carried out by t test, chi-square test, Mann-Whitney U test, and Kaplan-Meier survival analysis. Results:There were no significant differences in gender, age, or age of onset between the UV group and CSUwp group (all P < 0.05) . The proportions of patients with petechiae/purpura (68.57% [24/35] vs. 11.11% [6/54]) , and those with burning sensation (22.86% [8/35] vs. 3.70% [2/54]) were significantly higher in the UV group than in the CSUwp group (both P < 0.05) . Compared with the CSUwp patients, the UV patients presented with a greater number of lesions, larger lesion areas, and more frequent involvement of the lower limbs (all P < 0.05) , also showed significantly higher incidence rates of peripheral blood complement reduction, perivascular neutrophil infiltration, nuclear dust, fibrinoid necrosis of the vessel wall, and erythrocyte extravasation (all P < 0.05) , as well as more extensive dermal perivascular inflammation ( Z = -4.506, P < 0.001) . Among patients who achieved remission, the natural disease course was significantly longer in the CSUwp patients than in the UV patients (6.00 [2.5, 24] months vs. 2.00 [0.5, 24] months; Z = -2.618, P = 0.009]. However, the survival analysis showed no significant difference in the natural disease course or clinical outcomes between the two groups ( χ2 = 2.771, P = 0.096) . There were also no significant differences in rash duration or in the incidence rates of itching, angioedema, or joint pain between the two groups (all P > 0.05) . Conclusions:UV patients exhibited certain differences from CSUwp patients in clinical characteristics, laboratory test results, histopathological features, and prognosis. However, whether their natural disease courses differ requires further follow-up studies to confirm.

Objective:To evaluate the clinical equivalence between a domestic calcipotriol/betamethasone dipropionate ointment and the originator product in the treatment of stable plaque psoriasis.Methods:A multicenter, randomized, double-blind, three-arm, parallel-group, active- and placebo-controlled study was conducted, and 449 patients aged 18 - 65 years with stable plaque psoriasis were enrolled from 25 hospitals (such as the First Affiliated Hospital of China Medical University). Eligible patients had a baseline physician's global assessment (PGA) score of ≥ 3 points, baseline body surface area (BSA) involvement of 5% - 30%, and a target lesion psoriasis area and severity index (TL-PASI) for plaque elevation of ≥ 3 points. Participants were randomly assigned in a 2:2:1 ratio to the test group ( n = 179), reference group ( n = 180), and placebo group ( n = 90), and applied the domestic calcipotriol/betamethasone dipropionate ointment, originator product, and ointment base respectively, once daily in the evening for 4 weeks. Efficacy and safety were assessed at weeks 1, 2, and 4. The primary efficacy endpoints were the treatment success rates and clinical success rates in each group at week 4. The per-protocol set (PPS) was used for the primary efficacy analysis, and the intention-to-treat (ITT) set for supplementary efficacy analysis. Equivalence between the test and reference preparations was tested using the Cochran-Mantel-Haenszel method adjusted for randomization strata. Superiority of the test and reference preparations over the placebo was also tested. Measurement data were compared among the 3 groups using analysis of variance or non-parametric tests, while treatment success rates, clinical success rates, and incidence rates of adverse reactions were compared using the chi-square test. Results:The ITT, PPS, and safety sets included 447, 420, and 448 patients, respectively. In the ITT set, patients were aged 43.6 ± 12.8 years, including 320 (71.6%) males and 127 (28.4%) females, and the disease duration was 11.21 ± 9.05 years; 316 (70.7%) had a PGA score of 3 points and 131 (29.3%) had a PGA score of 4 - 5 points. No significant differences in the baseline characteristics (including age, sex, disease duration and disease severity) were observed among the 3 groups (all P > 0.05). Based on the PPS analysis, the treatment success rates were 57.9% (99/171) in the test group, 50.3% (86/171) in the reference group, and 7.7% (6/78) in the placebo group, and the clinical success rates were 57.9% (99/171), 50.3% (86/171), and 10.3% (8/78), respectively; both the test and reference groups were superior to the placebo group in both treatment and clinical success rates (all P < 0.001) ; the rate differences for treatment success (90% confidence interval [ CI]: -1.3% - 16.4%) and clinical success (90% CI: -1.3% - 16.3%) between the test and reference groups were entirely within the pre-defined equivalence margin (-20% - 20%). Subgroup analyses by baseline PGA scores: for patients with a baseline PGA score of 3 points, the treatment success rates in the test, reference, and placebo groups were 60.8% (73/120), 52.1% (62/119), and 11.1% (6/54), respectively, and the corresponding clinical success rates were 61.7% (74/120), 53.8% (64/119), and 13% (7/54), respectively; the test and reference groups did not differ significantly in treatment or clinical success rates (both P > 0.05), but both showed higher success rates than the placebo group (all P < 0.001) ; the results of statistical comparisons among the 3 groups in patients with a baseline PGA score of 4 - 5 points were consistent with those observed in patients with a baseline PGA score of 3 points. The percentage reductions in PGA and TL-PASI scores from baseline to weeks 1, 2, and 4 showed significant differences among the 3 groups, which were significantly higher in the test and reference groups than in the placebo group (all P < 0.001), but did not differ between the test and reference groups (all P > 0.05). The primary adverse reactions were local skin reactions, such as pruritus, pain, and erythema. The incidence rates of adverse reactions were 8.9% (16/179) in the test group, 7.3% (13/179) in the reference group, and 7.8% (7/90) in the placebo group, with no significant difference among the 3 groups ( P > 0.05) . Conclusions:The domestic calcipotriol/betamethasone dipropionate ointment demonstrated clinical equivalence to the originator product in the treatment of stable plaque psoriasis, and the two agents exhibited comparable efficacy for patients with varying degrees of disease severity, and were comparable in the speed and degree of clinical improvement, with similar favorable safety profiles.

Objective:To investigate the clinical manifestations, pathological features, and genetic variant characteristics of children with glycogen storage disease type Ⅸa (GSD Ⅸa).Methods:A retrospective case series analysis was conducted to collected and analyzed the medical history, biochemical markers, liver ultrasound results, liver histopathological findings, genotypes, treatment regimens, and follow-up data of 4 pediatric patients diagnosed with GSD IXa in the Department of Infectious Diseases at Xiamen Children′s Hospital from January 2018 to May 2024. All patients were confirmed by genetic testing.Results:All 4 pediatric patients diagnosed with GSD Ⅸa were male. The ages of onset were 8 months, 2 years, 3 years and 3 months, 1 year and 5 months, respectively, with initial presentations including chronic diarrhea (Case 1), incidentally detected transaminase elevation during routine examinations (Cases 2 and 3), and delayed motor development (Case 4). Diagnosis was confirmed at ages 10 months, 3 years, 3 years 4 months and 1 year 6 months, respectively.At diagnosis, anthropometric parameters and biochemical profiles revealed:Height: 68 cm (< P3), 96 cm ( P25-50), 94 cm ( P3-10), and 94 cm ( P3-10).Weight: 7 kg (< P3), 17 kg ( P90-97), 14.4 kg ( P25-50), and 10.5 kg ( P25-50).Alanine aminotransferase: 299, 500, 271, and 313 U/L (reference range 0-40 U/L).Aspartate aminotransferase: 285, 543, 337 and 357 U/L (reference range 0-40 U/L).Fasting glucose: 2.80, 3.67, 2.98, and 3.66 mmol/L (reference range 3.90-6.10 mmol/L).Lactate: 4.3, 2.1, 1.3, and 2.6 mmol/L (reference range 0.5-2.2 mmol/L).Triglycerides: 5.22, 1.38, 1.32, and 1.88 mmol/L (reference range 0.56-1.70 mmol/L).Case 1 exhibited poor adherence to uncooked cornstarch therapy during initial treatment, with no significant improvement in biochemical parameters. Follow-up imaging at age 4 revealed hepatic adenoma. Subsequent improvement in therapeutic compliance led to biochemical normalization, reduced hepatic adenoma size, and growth parameters of 113 cm ( P10-25) and 26 kg ( P90-97) at 6 years 2 months. Cases 2-4 demonstrated biochemical improvement with regular uncooked cornstarch therapy and no evidence of hepatic adenoma.Liver histopathology in Cases 1-3 confirmed glycogen accumulation consistent with GSD, without cirrhotic changes. Genetic analysis identified PHKA2 variations in all cases: 2 missense variants, 1 frameshift variant and 1 nonsense variant. The c.2839dup and c.3267G>A variants represent novel pathogenic mutations. Conclusions:GSD Ⅸa in pediatric patients is predominantly characterized by hepatomegaly, hepatic dysfunction, and hypoglycemia. While uncooked cornstarch therapy typically yields favorable prognoses, a subset of patients may develop hepatic adenomas. Notably, children with hepatic adenoma exhibited younger age of onset, significant growth retardation, and more severe metabolic disturbances, suggesting that hepatic adenoma development may be closely linked to the severity of metabolic dysregulation.

Objective:This study aims to explore the predictive value of the ratio of caliceal pelvic height to infundibular length（CPH/IL）for the stone-free rate（SFR）in the treatment of lower calyx stones using flexible ureteroscopic lithotripsy（FURL）combined with a distally bendable negative pressure suction sheath.Methods:A retrospective analysis was conducted on the clinical data and anatomical parameters of 312 patients with lower calyx stones or combined lower calyx stones admitted to the Third Xiangya Hospital of Central South University from September 2022 to December 2023，all of whom were treated with FURL combined with a distally bendable negative pressure suction sheath. Stone clearance was defined as no residual stones or residual stones with a diameter of ≤3 mm without any symptoms. Patients were divided into the clearance group（265 cases，84.90%）and the non-clearance group（47 cases，15.10%）. There were no significant differences in gender（male/female：173/92 cases vs. 29/18 cases），age［（44.69 ± 13.14）years vs.（42.60 ± 10.93）years］，degree of hydronephrosis（no hydronephrosis/mild hydronephrosis/moderate to severe hydronephrosis：122/85/58 cases vs. 21/12/14 cases），side of lower calyx stones（left/right：157/108 cases vs. 31/16 cases），maximum diameter of stones（MDS）［（19.23 ± 6.41）mm vs.（17.77 ± 6.18）mm］，and CT value of stones［（993.46 ± 249.12）Hu vs.（1013.43 ± 300.90）Hu］between the two groups（ P > 0.05），indicating comparability between groups. There was no significant difference in the distance from the midpoint of the lower lip of the renal pelvis to the ureter at the lowest plane of the lower calyx（K-A line）between the clearance and non-clearance groups［（26.16 ± 5.18）mm vs.（25.70 ± 8.66）mm， P > 0.05］. However，significant differences were observed in the infundibulopelvic angle（IPA）［（53.97 ± 15.72）° vs.（37.43 ± 15.39）°］，infundibular length（IL）［（27.26 ± 5.11）mm vs.（33.04 ± 7.38）mm］，infundibular width（IW）［（8.27 ± 2.82）mm vs.（7.09 ± 3.20）mm］，caliceal pelvic height（CPH）［（19.96 ± 4.63）mm vs.（30.32 ± 7.56）mm］，ureter-lower calyx distance（ULD）［（23.00 ± 5.59）mm vs.（18.78 ± 6.31）mm］，CPH/IL ratio［（0.73 ± 0.11）vs.（0.92 ± 0.09）］，and curvature of the lower calyx of the renal pelvis［（0.06 ± 0.01）mm -1 vs.（0.08 ± 0.03）mm -1］between the two groups（ P <0.05）. Univariate and logistic multivariate regression analyses were used to identify the independent risk factors affecting the postoperative SFR of FURL-treated lower calyx stones and to assess the value of CPH/IL for SFR in the treatment of lower calyx stones using FURL combined with a distally bendable negative pressure suction sheath. A logistic multivariate regression model and a corresponding nomogram were constructed，and the predictive ability of the model for SFR was evaluated using the receiver operating characteristic（ROC）curve. The calibration curve and the Hosmer -Lemeshow test were used to assess the consistency and accuracy of the model. The clinical utility of the model was evaluated using decision curve analysis（DCA）. Results:Univariate analysis revealed that seven anatomical parameters differed significantly between the clearance and non-clearance groups（all P < 0.05）：infundibulopelvic angle（IPA， OR = 0.27，95% CI 0.17-0.42， P < 0.01），infundibular length（IL， OR = 2.52，95% CI 1.83-3.47， P < 0.01），infundibular width（IW， OR = 0.64，95% CI 0.45-0.90， P = 0.011），caliceal pelvic height（CPH， OR = 5.78，95% CI 3.67-9.10， P < 0.01），ureter-lower calyx distance（ULD， OR = 0.43，95% CI 0.30-0.63， P < 0.01），CPH/IL ratio（ OR = 13.62，95% CI 6.86-27.03， P < 0.01），and curvature of the lower calyx of the renal pelvis（ O = 3.15，95% CI 2.08-4.78， P < 0.01）. Multivariate logistic regression further identified CPH/IL（ OR = 9.87，95% CI 4.92-19.79， P < 0.01），IPA（ OR = 0.41，95% CI 0.23-0.71， P = 0.001），and ULD（ OR = 0.50，95% CI 0.29-0.87， P = 0.014）as independent risk factors influencing the stone-free rate after flexible ureteroscopic lithotripsy combined with a distally bendable negative-pressure suction sheath. The area under the ROC curve（AUC）of the univariate regression model showed that for IPA，the AUC was 0.788（95% CI 0.711-0.864）；for IL，it was 0.731（95% CI 0.643-0.819）；for ULD，it was 0.677（95% CI 0.586-0.767）；for CPH，it was 0.867（95% CI 0.804-0.929）；for IW，it was 0.628（95% CI 0.535-0.721）；for CPH/IL，it was 0.906（95% CI 0.850-0.961）with an optimal cutoff value of 0.882，corresponding to a sensitivity of 83.02% and a specificity of 92.08%；and for curvature of the lower calyx of the renal pelvis，it was 0.744（95% CI 0.662-0.827）. The AUC of the multivariate regression model was 0.929（95% CI 0.884-0.974）with an optimal cutoff value of 0.364，corresponding to a sensitivity of 82.98% and a specificity of 95.09%. Calibration curves demonstrated close agreement between the predicted and actual stone-free rates after FURL（C-index = 0.921）. The Hosmer-Lemeshow goodness-of-fit test indicated no significant discrepancy between predicted and observed probabilities（ P = 0.135，>0.05）. Decision-curve analysis further revealed that basing clinical decisions on the model ，s predicted probability yields a higher net clinical benefit than either withholding FURL for all patients or treating all patients regardless of risk，and it also outperforms strategies guided by any single independent predictor alone. Conclusions:IPA，IL，IW，CPH，ULD，CPH/IL ratio，and curvature of the lower calyx of the renal pelvis can all predict the postoperative SFR of FURL combined with a distally bendable negative pressure suction sheath for the treatment of lower calyx stones to varying degrees. Among them，CPH/IL has the highest predictive value. When CPH/IL >0.88，it may be difficult to use FURL to treat lower calyx stones.