Search Results (145)

Objectives: Hypospadias is one of the most common congenital malformations of the male genitourinary system, and postoperative complications remain a major concern affecting surgical outcomes and patients‘ quality of life. Whether machine learning models can effectively predict complication risk using routinely available clinical variables remains unclear. Methods: A retrospective analysis was performed on 671 hypospadias patients who underwent urethroplasty at the Department of Urology, Capital Children’s Medical Center, between December 2015 and September 2024. The final dataset included 671 patients (training set: 536; validation set: 135). The median follow-up duration was 48 months (range: 19 to 72 months). Least absolute shrinkage and selection operator (LASSO) regression with nested cross-validation within the training set was used for feature selection, followed by the development of five machine learning models (Random Forest, XGBoost, LightGBM, Logistic Regression, and Support Vector Machine). Model performance was evaluated using AUC, calibration curves, Brier score, and decision curve analysis. Feature importance was assessed using SHapley Additive exPlanations (SHAP). Results: LASSO retained four features for model development: hypospadias type, surgical technique, surgeon experience, and patient age. The overall complication rate was 22.9% (154/671). Among the models evaluated, the Support Vector Machine (SVM) showed the most balanced performance in the validation set, achieving an AUC of 0.810 and a Brier score of 0.157. LightGBM demonstrated comparable performance (AUC: 0.802). SHAP analysis identified surgical technique as the most influential predictor, followed by surgeon volume and hypospadias type, though these findings should be interpreted with caution given the confounding between surgical complexity and disease severity. Conclusions: An interpretable SVM-based prediction model was developed and internally validated to stratify risk for postoperative complications after hypospadias repair using routinely available clinical variables. SHAP provided clinicians with visual insights into key risk-associated factors. However, given the single-center retrospective design and lack of external validation, further multicenter prospective studies are warranted to confirm the generalizability of these findings before clinical implementation. Full article

Flywheel energy storage systems impose high demands on the mechanical properties and structural integrity of rotors, particularly in high-speed applications. This study focuses on the numerical analysis of gravity casting of a steel rotor manufactured from low alloy 34CrMo4 steel, with the aim of identifying critical regions related to molten metal flow, solidification behaviour and shrinkage defect formation. Numerical simulations were calculated using a MAGMASOFT^® 5.5 software environment based on the finite volume method and included both mold filling and subsequent solidification and cooling stages. Flow stability, temperature field distribution and solidification characteristics were researched thoroughly. The results showed that optimization of the gating and feeding system lowered porosity under 2% within the casting and relocated shrinkage defects to the risers. At the same time, solidification directionality was improved and the Hot Spot value was reduced. From the perspective of casting quality, the proposed design represents the most suitable solution, despite a lower metal utilization rate. The analysed casting forms the structural body of a hybrid flywheel rotor intended for the subsequent integration of high-density tungsten segments. Full article

Pancreatic ductal adenocarcinoma is highly malignant with poor prognosis. Its dense tumor microenvironment severely limits the efficacy of conventional chemotherapy and causes severe side-effects. Herein, we adopt the established Schiff-base crosslinked thermoresponsive injectable self-healing poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate-co-aldehyde 2-hydroxyethyl methacrylate)/carboxymethyl chitosan (APMOH/CMCS) hydrogel as the delivery scaffold. By regulating monomer composition, the volume phase transition temperature (T_VPT) of the hydrogel was tuned to around 43 °C to match the therapeutic temperature requirement. Subsequently, copper–metal organic framework (Cu-MOF) nanoparticles co-loaded with 2,2′-azobis(2-methylimidazoline) dihydrochloride (AIPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cationic radicals (ABTS·⁺) (denoted as AB@Cu-MOF) were uniformly incorporated into the hydrogel network. Under near-infrared (NIR) irradiation, ABTS·⁺ acts as a photothermal agent to generate hyperthermia for tumor ablation; the elevated temperature further activates AIPH to produce alkyl radicals, which can oxidize inactivated ABTS back to ABTS·⁺ and construct a sustainable photothermal therapy–thermodynamic therapy (PTT-TDT) circulation. Meanwhile, Cu-MOF can consume intracellular glutathione (GSH) to protect active components from deactivation and initiate chemodynamic therapy (CDT) via Fenton-like reactions to produce toxic reactive oxygen species. Benefiting from the thermoresponsive characteristic, the hydrogel undergoes volume shrinkage upon heating, achieving NIR-triggered on-demand drug release with a cumulative release rate of 81.1%. In vitro and in vivo experiments verified that this integrated platform realizes remarkable triple synergistic efficacy of PTT, TDT, and CDT. The tumor volume of the treatment group was merely 13.3% of the control group, and the system also exhibited excellent biocompatibility. Collectively, it offers a feasible and promising intelligent platform for precise local treatment of pancreatic cancer. Full article

With the development of deep Earth engineering, the stability of surrounding rocks subjected to high temperatures from fire hazards has become an increasingly prominent issue. Therefore, studying the physical and mechanical properties of rocks under different thermal treatment modes is of great significance for the design of underground engineering. Taking red sandstone as the research object, this paper conducts physical parameter tests, uniaxial compression tests, and X-ray diffraction (XRD) on specimens under real-time high temperatures and natural cooling in the range of 600–1000 °C, to analyze the variations in specimen composition, the correlation between physical and mechanical properties and temperature, and to explore the underlying mechanisms. The results show that under both real-time high temperatures and natural cooling, the volume of sandstone increases while the mass decreases with rising temperature. At 1000 °C, the volume expansion rates are 3.30% and 3.80%, and the mass loss rates are 6.30% and 5.60%, respectively. Mechanical parameters, including peak strength, elastic modulus, and peak strain under the two treatments, all deteriorate significantly compared with those at room temperature. At 1000 °C, peak strength decreases by 54.83% and 36.26%, elastic modulus decreases by 74.55% and 67.96%, and peak strain increases by 65.63% and 43.75%, respectively. High-temperature-induced changes in the internal mineral structure and composition of sandstone are the main causes of rock mechanical property deterioration. During the cooling process, thermal shrinkage and recrystallization of mineral particles densify the rock structure; therefore, the compressive strength of naturally cooled sandstone is higher than that under real-time high temperatures. This study can provide theoretical guidance for the repair and reinforcement of rock engineering after high-temperature action. Full article

At present, research on the long-term stability of multi-cavern coordinated injection–production operations for salt cavern compressed air energy storage (CAES) remains limited. Large-capacity energy storage utilizing multiple interconnected salt caverns has become an inevitable development trend for modern CAES power stations, highlighting the necessity and importance of stability evaluation and design optimization for underground salt cavern storage clusters. Based on the Anning 350 MW CAES demonstration project, this paper takes the abandoned salt caverns of the project as research objects. A three-dimensional geological and cavern model is established using the FLAC3D numerical simulation method, and stability analysis is carried out under static conditions and three long-term gas injection and production scenarios (the pressure conditions are provided by ground-based equipment). The characteristics of the plastic zone, displacement, stress distribution, and volume shrinkage of the caverns are systematically investigated. The results show that under static conditions, the internal pressure significantly controls the development of the plastic zone, and the caverns are generally stable at pressures above 4 MPa. During long-term operation, the plastic zones of each cavern gradually expand, displacements accumulate continuously, and stresses tend to stabilize after an initial accumulation period. After 30 years of operation, no through-going plastic zones appear in any cavern, and all volume shrinkage rates are below 30%. Among the three cases, Case 1 exhibits the best stability, while enhanced monitoring is required for local high-stress regions in Case 3. This study verifies that the salt cavern development for the Anning CAES project is safe and controllable during long-term operation. The layout spacing of caverns is reasonably designed and fully satisfies the stability requirements of salt cavern CAES power stations. The research results can provide a technical guarantee for the construction of the first CAES power station in Yunnan Province and also offer a reliable reference for the design and construction of similar multi-cavity salt cavern CAES projects. Full article

This paper explores the internal rock plugging rules induced by oily sludge profile control systems in oilfields. Three typical sludges including wastewater tank bottom sludge (WTBS), crude oil tank bottom sludge (CTBS) and floating scum sludge (FSS) are adopted. Combined with micro-CT scanning and digital core technology, this paper systematically investigates the pore–throat structure evolution and damage mechanism before and after sludge injection into rock cores. Key parameters such as plugging rate, average pore radius, throat radius, coordination number, shape factor, pore–throat ratio and pore–throat volume are quantitatively characterized macroscopically and microscopically, which reveal diverse damage modes and plugging mechanisms of the three sludges. The results indicate that pores of 10–50 μm are preferentially blocked by all sludges. CTBS causes the severest core damage with an average plugging rate of 79.67%, and the average coordination number decreases from 4 to 1, governed by the mechanism of adsorption diameter reduction and structural destruction. WTBS leads to uniform jamming of fine particles. Its average parameters change slightly, yet permeability declines due to broken critical throats. It follows the mechanism of uniform filling and weak adsorption with an average plugging rate of 56.75%, showing mild reservoir modification capacity. FSS causes moderate damage. Retained emulsion droplets trigger uniform slight shrinkage of pore throats under partial and overall selective filling mechanism, with an average plugging rate of 63.36% and favorable selective plugging performance. This study clarifies the inherent correlation between macroscopic damage and microscopic behaviors of oily sludge, offering microscopic theoretical references for differentiated management of sludge reinjection and oil displacement with composite sludge profile control agents. Full article

To promote the practical application of metakaolin-slag geopolymer materials in engineering repair, it is essential to clarify the influence of mix proportion parameters on macroscopic properties, given their inherent deficiencies of inferior toughness and volume stability. In this study, a five-factor and four-level orthogonal experimental design was adopted to systematically investigate the effects of slag content, water glass modulus, alkali equivalent, water–binder ratio, and sand–binder ratio on the fluidity, compressive strength, flexural strength, compressive-to-flexural strength ratio (toughness indicator), and drying shrinkage rate (volume stability indicator) of geopolymer mortar. Range analysis and variance analysis were conducted to clarify the primary and secondary order of influencing factors for each performance index, and the optimal mix proportion balancing multiple performance demands was determined. The results indicate that alkali equivalent is the core factor governing compressive and flexural strength, whereas slag content dominates the compressive-to-flexural ratio, fluidity and drying shrinkage. The geopolymer mortar achieves relatively optimal comprehensive performance when the slag content is 20%, the sodium silicate modulus is 1.6, the alkali equivalent is 12%, the water-to-binder ratio is 0.49, and the sand-to-binder ratio is 2:1, and all indicators meet the specification requirements for rigid repair mortar. Combined with SEM-EDS and XRD microstructural analysis, the main products of the metakaolin-slag system are amorphous N-A-S-H gel and C-(A)-S-H gel. Appropriate alkali equivalent and slag content can promote the dissolution of aluminosilicate raw materials and facilitate the formation of both gel products, providing microstructural support for the improvement of macroscopic performance. Full article

Background: Hemolysis and eryptosis of red blood cells (RBCs) contribute to chemotherapy-induced anemia, a marker of poor prognosis. Geraniol (GER) is an anticancer acyclic monoterpene alcohol found in several plant extracts, but a dearth of evidence exists regarding the potential toxicity of GER in RBCs. Methods: Hemolysis and eryptosis were evaluated using colorimetric and fluorescence-assisted cell-sorting methods, respectively. Phosphatidylserine (PS) exposure, loss of volume, and intracellular Ca²⁺ were measured by annexin-V-FITC, forward scatter (FSC), and Fluo4/AM staining. Cells were also examined by electron microscopy to identify membrane blebbing and by the Westergren method to assess erythrocyte sedimentation rate (ESR). Results: In a concentration-responsive fashion, GER induced hemolysis and PS exposure in addition to elevated ESR. GER-induced cell death was characterized by reduced FSC, membrane blebs, and increased Fluo4 fluorescence. Ca²⁺ deprivation prevented eryptosis, whereas concurrent Ca²⁺ deprivation and membrane depolarization prevented hemolysis, eryptosis, and cell shrinkage. Furthermore, whereas inhibition of cyclooxygenase (COX), casein kinase 1α (CK1α), or Rac1 GTPase ameliorated eryptosis and hemolysis, the latter was only prevented by caspase, nitric oxide synthase, or serine palmitoyltransferase inhibition. Exclusive reversal of eryptosis was rather only achieved in the presence of either caffeine or adenine. Conclusions: GER is a novel stimulator of hemolysis and eryptosis, an activity mediated through membrane hyperpolarization following Ca²⁺ elevation. In parallel, GER seems to involve the COX/CK1α/Rac1 GTPase axis to trigger its cytotoxic effects. Targeting the identified mechanisms in combination therapy may attenuate the off-target toxicity of GER and enhance its specificity to cancer cells. Full article

Perioptic meningiomas pose a therapeutic challenge due to their proximity to critical visual structures. Single-fraction stereotactic radiosurgery is known to effectively control the growth of meningiomas, but this subgroup carries the risk of optic neuropathy, which is minimized with the introduction of dose hypofractionation. The Leksell Gamma Knife Icon has perfected fractionated stereotactic radiosurgery, maintaining submillimeter accuracy in each dose fraction without the need for an invasive frame. This study analyzes the feasibility, safety, and efficacy of multi-fraction Gamma Knife Icon radiosurgery for perioptic meningiomas, taking into account tumor control rates, visual preservation, and treatment-related toxicity. We conducted a retrospective analysis of 100 patients with a perioptic meningioma treated with fractionated Gamma Knife Icon radiosurgery between September 2017 and December 2022. A total of 80 Patients were female, and 20 were male; the mean age was 61.7 years (range 35–84). The most frequent anatomical locations included: cavernous sinus (35 pts), anterior clinoid (17 pts), sphenoid wing (14 pts) and olfactory groove (11 pts). The median tumor volume was 5.6 mL (range 0.12–31.7 mL). Most patients (89%) received 25 Gy in five fractions. Tumor control was achieved in 98% of cases, with a mean radiological follow-up of 41.2 months. Tumor volume did not predict radiological shrinkage (p = 0.639). Tumor shrinkage was observed more frequently in the no prior surgery group (p = 0.035). The mean clinical follow-up was 45.3 months. Among symptomatic patients (35 pts) at baseline, symptoms remained stable in 27 (77%) cases, improved in 5 (14%), and worsened in 3 (9%). No new symptoms were observed in asymptomatic patients. Overall clinical deterioration occurred in three (3%) patients—one because of tumor progression; although, without statistical evidence (p = 0.217), worsened patients had notable larger mean tumor volumes (12.6 mL vs. 6.8 mL). The dosimetric advantages of Gamma Knife technology are empowered by the biological benefits of fractionation and the convenience of non-invasive immobilization. Excellent tumor control rates and positive visual outcomes favor its routine application in properly selected patients. Full article

Salt cavern CO₂ storage (SCCS) technology represents a crucial pathway for achieving large-scale carbon sequestration. However, its long-term operation faces the challenge of cavern shrinkage due to surrounding rock creep, which directly impacts storage safety and stability. Despite its importance, there is currently a lack of research focusing on the proactive control of SCCS cavern shrinkage and its collaborative optimization with operational economy. To fill this gap, this paper first investigated the effects of the stress state (f₁), height-to-diameter ratio (f₂), symmetry factor (f₃), and cavern volume (f₄) on the volumetric shrinkage rate through numerical simulations of regular caverns and univariate sensitivity analysis. The sensitivity ranking and quantitative relationships of these factors were clarified as $f_1(2.31)>f_4(0.309)>f_2(0.166)>f_3(0)$. Subsequently, a multi-objective nonlinear optimization model was established, and the primal-dual interior-point method was adopted as the solution algorithm. Using actual cavern data as a case study for the solution, the results demonstrate that the optimization model converges stably in approximately 1.1 s. The resulting optimal gas injection allocation scheme achieves a 14.77% improvement in the comprehensive score compared to the baseline scheme. This study provides a theoretical basis and a practical tool for the rapid generation of SCCS gas injection allocation schemes. Full article

Introduction: Evidence on the use of dopamine agonists (DAs) for managing residual or recurrent non-functioning pituitary adenomas (NFPAs) is limited. We aim to evaluate the use of cabergoline (CAB) for NFPAs. Methods: A retrospective cohort study was conducted at a single UK centre, between November 2011 and December 2025. Twenty-six patients were identified. Ten patients were excluded due to CAB intolerance or discontinuation (n = 5), insufficient data (n = 4), or invalid scan due to patient movement (n = 1). The remaining 16 patients (mean age 68.9 ± 4 years (range 42–89 years old), 7/16 females) were included. CAB was initiated in cases where surgery or radiotherapy were not appropriate (e.g., due to age and/or comorbidities, or patient choice). Radiological response was assessed using at least two scans separated by a minimum interval of six months. Tumour shrinkage was defined as a reduction in volume of 20% or more, growth as an increase of 20% or more, and stabilisation as interval change of less than 20%. Results: Overall, tumour shrinkage was observed in 7/16 (43.8%) patients, stabilisation in the remaining 9/16 (56.3%) patients, over 503 ± 51 days (range of 117–934 days) (from the date of CAB initiation to latest MRI scan). There was a statistically significant reduction in tumour volume (p = 0.0335). In five patients with documented tumour growth prior to CAB initiation, growth rates retarded or reversed post-CAB initiation. Conclusions: Our findings in this small cohort potentially suggests that cabergoline can retard, arrest, or even reverse tumour growth in selected patients with NFPAs. Our review also highlights ongoing uncertainty regarding optimal dosing, approaches to dose up-titration, follow-up imaging intervals, and objective criteria for defining radiological response. Our results may provide a proof of concept for future, larger-scale prospective studies and controlled trials to validate the conclusions drawn. Full article

Background: Transvaginal radiofrequency ablation (TRFA) is a minimally invasive, uterus-preserving technique for symptomatic uterine fibroids. This study evaluates its two-year clinical and volumetric outcomes, safety profile, patient satisfaction, and reintervention rates. Methods: In this single-center, retrospective, single-arm observational cohort study, 121 premenopausal women underwent outpatient TRFA under general anesthesia between 2018 and 2023. Follow-up visits at 1, 6, 12, and 24 months assessed fibroid volume reduction, symptom improvement using the Uterine Fibroid Symptom and Quality of Life Questionnaire (UFS-QoL), vascularity, satisfaction, complications, and the need for reintervention. A total of 169 fibroids were treated. Results: TRFA resulted in progressive fibroid shrinkage, with a mean volume reduction of 57.97% at 6 months and 60.75% at 24 months, accompanied by sustained improvement in UFS-QoL scores (from 30.19 at baseline to 14.97 at 24 months). Patient satisfaction was high (96.61%). Complications were infrequent and predominantly mild, and recovery was rapid, with short postoperative analgesia (mean 2.87 days) and limited sick leave (mean 3.34 days). The two-year reintervention rate was 24.79%, with a substantial proportion corresponding hysteroscopic procedures planned a priori as part of a sequential therapeutic strategy. Among 22 pregnancies recorded after TRFA, 81.82% resulted in term deliveries with favorable neonatal outcomes although fertility was not a predefined study endpoint. Conclusions: TRFA appears to be a safe, effective, and well-tolerated minimally invasive treatment for symptomatic uterine fibroids, offering durable symptom relief and significant volume reduction and rapid recovery, and encouraging reproductive outcomes. Within the limitations of its single-arm observational design, these results support TRFA as a valuable uterus-preserving therapeutic option. Full article

Thermoresponsive chitosan hydrogels hold significant promise for advancing biomedical technologies, yet their frequent reliance on petroleum-based polymers raises biosafety and environmental concerns. The present study utilized a molecular functionalization strategy to transform chitosan into thermoresponsive alkylated chitosan (ICS). The ICS was subsequently covalently crosslinked to construct a fully degradable, all-chitosan thermoresponsive hydrogel (TR-ICS_gel), showcasing the effective integration of structural design and functionality. By adjusting the ICS concentration, TR-ICS_gels with varying volume phase transition temperatures (VPTTs) were obtained. Above the VPTT, strengthened alkyl chain hydrophobic interactions triggered hydrogel dehydration and pronounced, reversible shrinkage–swelling. The hydrogel maintained a stable swelling response over 20 consecutive temperature-stimulus cycles. Further investigation was conducted on the effects of ionic strength and small-molecule solvents on the thermoresponsive behavior of TR-ICS_gel. Soil burial and buffer solution tests demonstrated that the hydrogel underwent almost complete degradation within 27 and 15 days, respectively, and the degradation rate could be regulated by the ICS concentration. The TR-ICS_gel’s all-chitosan framework ensured excellent biocompatibility, with cell viability maintained above 95%. This study presents a strategy for developing fully bio-based, degradable smart hydrogels, enhancing biosafety and environmental friendliness. Moreover, these results provide crucial performance data and theoretical support for their practical application. Full article

Shrinkage of injection-molded parts is a major challenge for dimensional accuracy, especially for semi-crystalline polymers where crystallization induces pronounced volume change and heat release during cooling. Because packing pressure is effective only before gate or local solidification, multi-stage packing is commonly used to regulate the overall shrinkage behavior. In practice, however, the solidification/transition temperature taken from standard material tests does not necessarily represent the actual in-cavity state behavior under specific cooling rate and pressure history, which compromises the consistency of P–V–T-based shrinkage prediction. In this study, a modified P–V–T-based framework (Tait equation) is developed for polypropylene (PP) by introducing a Thermal Enthalpy Transformation Method (TETM) to determine a process-relevant solidification time and crystallization-completion temperature (including the corresponding target specific volume) directly from in-cavity melt temperature monitoring using an infrared temperature sensor. The novelty TETM utilizes the crystallization-induced enthalpy release to identify the temperature–time plateau, from which one can identify the effective solidification point. Because the Tait equation adopts a two-domain formulation (molten and solidified states), accurate identification of the domain-switching temperature is critical for reliable shrinkage prediction in practical molding conditions. In the experiment execution, the optimum filling time was defined using the minimum pressure required for melt-filling. Four target specific volumes, three melt temperatures, and two mold temperatures were examined, and a two-stage packing strategy was implemented to achieve comparable shrinkage performance under different target specific volumes. A conventional benchmark based on the solidification temperature reported in the Moldex3D material database was used for comparison only. The results show that the target specific volume determined by the TETM exhibits a more consistent and near-linear relationship with the measured shrinkage rate, demonstrating that the TETM improves the robustness of solidification-time identification and the practical usability of P–V–T information for shrinkage control. Full article

Objectives: To explore if MRI can monitor treatment and predict outcome in patients with human epidermal growth factor 2 (HER2)-negative breast cancer receiving neoadjuvant chemotherapy (NACT) with or without bevacizumab. Methods: Multiparametric MRI was performed at baseline and after 12 and 25 weeks of NACT. MRI assessment included tumour size, apparent diffusion coefficient (ADC) from diffusion-weighted imaging (DWI), and signal intensity–time curves and vascular volume transfer constant (K^TRANS) from dynamic contrast-enhanced MRI (DCE). The reference standards were pathological complete response (pCR) at the time of surgery, and 10-year recurrence-free survival. Receiver operating characteristics analyses were performed to assess the predictive value of the MRI parameters. MRI findings and outcomes were compared between the treatment groups. Results: Seventy women were included from November 2008 to July 2012, with a median age of 49.5 years and median tumour diameter of 47 mm. Fourteen patients (20.0%) achieved pCR, while eleven (15.7%) had recurrence during the 10-year follow-up. The treatment significantly reduced tumour size, increased ADC, decreased K^TRANS, and shifted the signal intensity–time curves towards more benign shapes. The DCE parameters changed significantly more in the bevacizumab group. In the bevacizumab group, baseline K^TRANS predicted pCR (Area under curve (AUC) = 0.73), but the difference in pCR-rates between the treatment groups was not significant (p = 0.07). Only tumour size and shrinkage at 12 weeks predicted pCR (AUC = 0.71–0.85) regardless of size measuring method. No MRI parameters predicted survival. Conclusions: All MRI parameters reflected treatment response, but no parameter predicted survival or benefit from adding bevacizumab to chemotherapy. Full article