Search Results (294)

Background: Microwave ablation (MWA) is an effective, minimally invasive therapy for benign thyroid nodules; however, the treatment response varies considerably. Identifying imaging biomarkers that can predict volumetric outcomes may optimize patient selection. Diffusion-weighted MRI (DW-MRI) offers a noninvasive assessment of tissue microstructure through apparent diffusion coefficient (ADC) measurements, which may correlate with ablation efficacy. Methods: In this prospective study, 48 patients with 50 cytologically confirmed benign thyroid nodules underwent diffusion-weighted magnetic resonance imaging (DW-MRI) before minimally invasive ablation (MWA). Baseline ADC values were measured, and nodule volumes were assessed by ultrasound at baseline and 1, 3, and 6 months postprocedure. The volume reduction ratio (VRR) was calculated, and associations with baseline variables were analyzed via Pearson correlation and multivariable linear regression. ROC curve analysis was used to evaluate the diagnostic performance of ADC in predicting significant volume reduction (VRR ≥ 50%). Results: Lower baseline ADC values were strongly correlated with greater VRR at 3 months (r = −0.525, p < 0.001) and 6 months (r = −0.564, p < 0.001). Multivariable regression revealed that the baseline ADC was the sole independent predictor of the 6-month VRR (β = −19.52, p = 0.0004). ROC analysis demonstrated excellent discriminative performance (AUC = 0.915; 95% CI: 0.847–0.971), with an ADC cutoff of 2.20 × 10⁻³ mm²/s yielding 90.9% sensitivity and 83.3% specificity for predicting a favorable volumetric response. Conclusions: Baseline ADC values derived from DW-MRI strongly predict volumetric response following microwave ablation of benign thyroid nodules. Incorporating ADC assessment into preprocedural evaluation may enhance patient selection and improve therapeutic outcomes. Full article

Objectives: Obesity and atrial fibrillation (AF) are strongly linked and are both associated with significant left atrial (LA) pathology. This study aimed to assess differences in LA size and function between obese and non-obese AF patients and to evaluate AF recurrence in both groups. Materials and Methods: We retrospectively analyzed patients undergoing first-time ablation for AF. Obesity was defined as body mass index ≥30 kg/m², and patients were divided accordingly into obese and non-obese groups. Results: Among 672 patients (median age of 66 years; 39.1% women), 308 (45.8%) were obese. Obese patients had significantly larger LA dimensions (LA area, LA volume, and LAVI indexed to height² (but not that indexed to body surface area (BSA)); p < 0.001), as well as higher LA-pressure-related parameters (LA stiffness index (p = 0.004), E-wave velocity (p = 0.002), and E/e′ ratio (p < 0.001)) and invasively measured mean LA pressure (p < 0.0001). However, there were no significant differences in parameters directly reflecting LA function, such as LA emptying fraction, LA reservoir strain, or LA appendage velocity. These findings remained consistent in the sinus rhythm subgroup (n = 374). The 1-year AF recurrence rate did not differ between obese and non-obese groups (data available for 73.8% (496) patients; p = 0.40), regardless of baseline rhythm. Conclusions: In AF patients undergoing their first ablation, obesity was associated with a larger LA size and higher LA pressure. In obese individuals, indexing LA dimensions to height² seems to better reflect LA enlargement than indexing to BSA. LA function and AF recurrence rates after a 1-year follow-up period were similar between obese and non-obese patients. Full article

Background/Objectives: This secondary analysis aims to evaluate various prognostic factors for overall survival (OS) and hepatic progression-free survival (hPFS) and to perform subgroup analyses regarding OS of patients with unresectable and chemotherapy-refractory liver metastases from colorectal cancer (LMCRC) treated by the combination therapy of transarterial chemoembolization (TACE) and microwave ablation (MWA) or with MWA alone. Methods: A total of 251 patients with unresectable and chemotherapy-refractory LMCRC were included retrospectively. Group A consisted of 184 patients who received a combination of TACE and MWA. A total of 67 patients were included in group B, who received only MWA. Group C summarizes the total number of 251 patients treated. For all groups, the influence of age, sex, number of metastases, the diameter and volume of the largest metastasis, and the occurrence of recurrence on OS and hPFS was determined using univariate cox regression analysis. OS was compared between patients with more than three metastases and those with three or fewer, as well as between patients with a diameter of largest metastasis of 3 cm or less with patients with a diameter of largest metastasis of more than 3 cm. The analysis of OS was carried out using the Kaplan–Meier method. Results: For all three groups, the parameters of age, sex, number of metastases, diameter and volume of the largest metastasis, complete ablation status, and recurrence were not significant prognostic factors for OS. The number of metastases had a statistically significant influence on hPFS in group C (p = 0.034) and trended towards significance in group A (p = 0.057). The mean OS of patients with three metastases or less was in all groups longer than patients with more than three metastases, however, with no statistically significant differences (p = 0.83, 0.451 and 0.84 for groups A, B and C, respectively). There were no significant differences regarding OS between patients with diameter of largest metastasis of 3 cm or less compared to patients with diameter of largest metastasis more than 3 cm in all groups (p = 0.316, 0.812 and 0.45 for groups A, B and C, respectively). Conclusions: We could not observe significant prognostic factors in the treatment of LMCRC on OS. Accordingly, patients with three metastases or less had non-significant longer OS than patients with more than three metastases. The number of metastases had a significant impact on hPFS of the whole patient cohort and borderline significant impact on hPFS in patients treated with TACE combined with MWA. Full article

Background: Despite advances in ablation strategies, a substantial proportion of patients with atrial fibrillation (AF) experience arrhythmia recurrence, highlighting the need for improved preprocedural risk stratification. One of the emerging factors associated with arrhythmogenic remodeling is epicardial adipose tissue (EAT), particularly in the proximity of the left atrium (LA), due to its metabolic and inflammatory activity. Methods: This study investigated whether preprocedural assessment of EAT parameters on computed tomography (CT), including volume, mean attenuation, and attenuation dispersion, could predict AF recurrence following ablation. Seventy patients with AF underwent either pulsed field or cryoballoon ablation and were followed for 18 months. Results: Recurrence of AF occurred in 26 (37.1%) patients. Both higher LA-EAT attenuation (OR 1.09; 95% CI: 1.02–1.17) and greater total-EAT volume (OR 2.41; 95% CI: 1.16–4.99) were independently associated with arrhythmia recurrence. Subgroup analysis revealed that LA-EAT volume was highly predictive of recurrence in patients with persistent AF (AUC = 0.91), whereas LA-EAT attenuation demonstrated greater prognostic value in those with paroxysmal AF (AUC = 0.80). Conclusions: These findings suggest that quantitative evaluation of EAT using routine cardiac CT may enhance risk stratification before ablation. Full article

This study investigates the heat transfer characteristics of high-temperature alumina droplets impacting carbon–phenolic ablative materials in solid rocket motors using the Volume of Fluid (VOF) method. Simulations under varied droplet diameters, impact velocities, wall temperatures, and accelerations were carried out, and the simulation method was validated against experimental data. Results show that heat flux drops rapidly from 20 MW/m² to below 5 MW/m² after the non-dimensional time $t^{*}$ = 0.5, due to solidified layer formation at the droplet bottom, which shifts heat transfer from convection to conduction and increases thermal resistance. The solidified layer is thicker at the sides and thinner in the center, caused by weaker heat transfer in the thinner side regions. Acceleration is found to have a negligible influence on impact dynamics within wall temperatures of 25 °C to 1000 °C, as potential energy conversion during spreading is insignificant compared to kinetic energy. Thus, droplet–wall heat transfer dominates the process. These findings provide critical thermal boundaries for ablation modeling and improve design guidance for SRMs. Full article

(1) Background: In the context of cardiac radiofrequency (RF) ablation, it has been proposed that positioning the dispersive patch (DP) concordantly with the orientation of the ablation electrode may enhance lesion size. The objective of this study is to investigate how individual body size may modulate the extent of this effect. (2) Methods: Three computational models representing different body sizes were developed. An irrigated catheter ablation was simulated by delivering a 30 W pulse for 30 s to the endocardial surface of the anterior wall. Lesion sizes were then compared between two configurations of the dispersive patch (DP): an anterior (concordant) position and a posterior (discordant) position. (3) Results: Lesion size was consistently and significantly greater with concordant DP positioning compared to discordant positioning. Moreover, the magnitude of this difference decreased significantly with increasing body size, ranging from 0.65 ± 0.08 mm in the 35 kg swine model to 0.51 ± 0.06 mm in the human model. (4) Conclusions: Body size has a modest influence on the effect of dispersive patch positioning on RF lesion size. The potential advantage of a concordant DP configuration may be more significant in individuals with smaller body volume. Full article

In traditional in situ leaching (ISL) uranium mining, the injection volume depends on technicians’ on-site experience. Therefore, applying artificial intelligence technologies such as machine learning to analyze the relationship between injection volume and leaching rate in ISL uranium mining, thereby reducing human factor interference, holds significant guiding importance for production process control. This study proposes a novel uranium leaching rate prediction method based on a CNN–LSTM–LightGBM fusion model integrated with an attention mechanism. Ablation experiments demonstrate that the proposed fusion model outperforms its component models across three key metrics: Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Root Mean Square Error (RMSE). Furthermore, comparative experiments reveal that this fusion model achieves superior performance on MAE, MAPE, and RMSE metrics compared to six extensively utilized machine learning methods, including Multi-Layer Perceptron, Support Vector Regression, and K-Nearest Neighbors. Specifically, the model achieves an MAE of 0.085%, an MAPE of 0.833%, and an RMSE of 0.201%. This attention-enhanced fusion model provides technical support for production control in ISL uranium mining and offers valuable references for informatization and intelligentization research in uranium mining operations. Full article

With increasing urbanization and population growth, the volume of municipal solid waste (MSW) continues to rise. Efficient and environmentally responsible waste processing has become a core issue in sustainable development. Incineration plays a key role in reducing landfill usage and recovering energy from waste, contributing to circular economy initiatives. However, fluctuations in furnace temperature significantly affect combustion efficiency and emissions, undermining the environmental benefits of incineration. To address these challenges under dynamic operational conditions, this paper proposes a hybrid model combining an Improved Snow Ablation Optimizer (ISAO), Dual-Branch Convolutional Neural Network (DBCNN), and Bidirectional Long Short-Term Memory (BiLSTM). The model extracts dynamic features from control and condition variables and incorporates time series characteristics for accurate temperature prediction, thereby enhancing the overall efficiency of the incineration process. ISAO integrates Lévy flight, differential mutation, and elitism strategies to optimize parameters, contributing to better energy recovery and reduced emissions. Experimental results on real MSWI data demonstrate that the proposed method achieves high prediction accuracy and adaptability under varying operating conditions, showcasing its robustness and application potential in promoting sustainable waste management practices. By improving combustion efficiency and minimizing environmental impact, this model aligns with global sustainability goals, supporting a more efficient, eco-friendly waste-to-energy process. Full article

Background/Objectives: For many years, catheter ablation (CA) has been a cornerstone in atrial fibrillation (AF) rhythm control therapy; however, recurrence remains common. Multiple parameters have been proposed to quantify AF arrhythmogenic substrate, yet reliable predictors of long-term outcomes are lacking. To assess the value of non-invasive amplified P-wave duration (PWD), echocardiographic parameters, biomarkers, and electroanatomical mapping (EAM) were used in predicting left atrial (LA) fibrosis and arrhythmia recurrence after CA. Methods: We included 196 patients undergoing first CA for paroxysmal or persistent AF. Amplified 12-lead ECG PWD parameters [Pmax, Pmin and left atrial P-wave (LAP)], echocardiographic parameters, and biomarkers were assessed pre-procedure. We measured low-voltage areas (LVA, 0.2–0.5 mV) on high-density voltage EAM during sinus rhythm as a surrogate of fibrosis. Freedom from arrhythmia was evaluated at 6 and 12 months. Results: Patients with LVA on EAM had prolonged Pmax (148 vs. 135 ms, p < 0.0001), Pmin (111 vs. 101.5 ms, p = 0.0001), LAP (73.5 vs. 55.5 ms, p < 0.0001), larger LA diameter (p = 0.0002), area (p = 0.0365) and volume (p = 0.004), higher E/E’ (p = 0.0007) and E/A ratios (p = 0.037), more mitral regurgitation (p = 0.0315), and higher pro-BNP levels (p = 0.0094). Univariate analysis showed 12-month recurrence rates higher with greater Pmax, Pmin, LAP, LVA presence and extent; however, in multivariate analysis, only P-wave parameters remained independently associated with recurrence. Conclusions: Prolonged PWD parameters strongly reflect LA substrate (Pmax, Pmin) and independently predict post-ablation AF recurrence (Pmax, Pmin, and LAP). LA size, diastolic dysfunction, and mitral regurgitation were associated with LA fibrosis, while pro-BNP was associated with both fibrosis and arrhythmia recurrence. Integrating these simple, non-invasive markers into a multimodal assessment alongside EAM could improve pre-procedural risk stratification and guide individualized ablation strategies. Full article

Background: Liver function is a critical factor, both in the selection of treatment and in the prediction of prognosis in patients with hepatocellular carcinoma (HCC). The ALBI grade, introduced as a more objective method of assessing liver function, utilizes serum albumin (Alb) and total bilirubin (Bil) levels. Although albumin is widely recognized for its role in maintaining colloid osmotic pressure and regulating plasma volume, recent studies have implicated it in tumor progression, invasion, and metastasis. The purpose of this study is to determine the impact of serum albumin levels on overall survival (OS) and tumor invasion/metastasis in HCC patients with the same liver function (ALBI grade) at the time of diagnosis. Methods: In this study, 285 patients diagnosed with primary HCC at our institution from 2015 to 2019 were classified by ALBI grade and analyzed. Among them, 78 patients with ALBI grade 2 status were selected to evaluate the impact of albumin level. To further isolate the effect of albumin rather than bilirubin, patients in the ALBI grade 2 cohort were divided into two groups based on mean values of Alb (3.5 g/dL) and Bil (1.0 mg/dL). Alb normal group (Group A): Alb ≥ 3.5 g/dL, Bil ≥ 1.0 mg/dL (n = 42). Bil normal group (Group T): Alb < 3.5 g/dL, Bil < 1.0 mg/dL (n = 36). Liver function was almost the same in these two groups based on the ALBI grade. OS, progression-free survival (PFS), types of recurrence, and pathological findings were compared between the two groups. OS was analyzed by the log-rank test, and comparisons between the two groups were performed by the t-test and chi-square test, with p < 0.05 indicating statistical significance. Results: OS was significantly worse in Group T than in Group A before and after propensity score matching based on age, performance status, and HCC stage (p < 0.001 and p = 0.011). Among the 44 patients who received curative treatment (surgery or radiofrequency ablation), OS was also significantly worse in Group T (p < 0.001). An analysis of the recurrence patterns of 44 curatively treated patients revealed that Group T had significantly shorter PFS (p < 0.001), and all recurrence patterns were multiple (p = 0.002). Pathological analysis in 28 surgical patients showed that serosal invasion was present in significantly more patients in Group T (p = 0.003). Conclusions: Low serum albumin levels in patients with HCC indicate both liver dysfunction and increased tumor invasion and metastasis. Nutritional support and albumin supplementation may help reduce intrahepatic metastases and improve prognosis. Further studies are needed to explore the underlying mechanisms and therapeutic potential. Full article

Background/Objectives: Cryoablation is a minimally invasive treatment option for patients with a small renal mass (SRM). We aimed to present the long-term functional and oncologic outcomes of cryoablation for SRMs. Methods: We retrospectively reviewed patients treated with percutaneous or laparoscopic cryoablation for an SRM (≤4 cm in diameter) at our tertiary hospital between October 2001 and December 2011. Primary outcomes included technical failure (persistent CT enhancement post-ablation) and progression (local recurrence or metastasis). Trifecta is defined as the absence of severe complications (Clavien–Dindo > 2), no oncological progression, and ≤10% decline in eGFR. Results: A total of 129 patients with a median age of 67 (IQR 58–74) years were analyzed. The median (IQR) clinical and radiologic follow-ups across all patients were 136 (54–180) and 74 (23–147) months, respectively, with a median (IQR) tumor volume of 3.3 (1.6–6.6) cm³. Among those with available biopsy data (n = 86), 62 (72%) were diagnosed with Renal Cell Carcinoma (RCC), and 24 (28%) exhibited benign pathologies, including angiomyolipoma, oncocytic neoplasm, and non-diagnostic pathology. Of all patients, six experienced high-grade complications. Among non-solitary kidney patients with available creatinine values between 13 and 36 months post-treatment, 64% had ≤10% eGFR decline compared to baseline. Notably, 58% (26/48) of patients with RCC (non-solitary kidney) achieved our trifecta definition at 36 months. Metastasis-free, cancer-specific, and overall survival at 15-year follow-up were 85%, 96%, and 46%, respectively. Univariable regression identified tumor volume and solitary kidney status at ablation as significant predictors for oncological progression. Conclusions: Cryoablation for the SRM showed sustained oncological and functional efficacy over long-term follow-up. Full article

Objectives: There is a critical need for effective focal therapies for patients with inoperable or anatomically complex tumors where conventional ablation techniques pose high risk or are ineffective. Integrated Nanosecond Pulsed Irreversible Electroporation (INSPIRE) is a novel non-thermal ablation modality which uses real time temperature feedback during pulse delivery to safely treat tumors near critical structures. This study evaluated the impact of exposed electrode length on ablation zone size, reproducibility, and cardiac safety in a large animal model. Methods: INSPIRE treatments were performed in an in vivo healthy porcine liver model. All treatments administered 6000 V 1000 ns pulses with a 45 °C temperature set point. Treatments were administered percutaneously via an electrode and grounding pad approach using an internally cooled electrode applicator. The exposed electrode region at the distal end of the applicator was set to either 0.5, 1.0, 1.5, or 2.0 cm. Ablation zones were assessed via ultrasound, contrast-enhanced CT, and gross pathology one week post-treatment. Cardiac safety was evaluated by measuring pre- and post-treatment serum Troponin levels. Results: All treatments were completed without adverse events. Troponin levels remained stable (pre: 0.249 ng/mL; post: 0.224 ng/mL), indicating no measurable cardiac injury. The 1.5 cm exposure length produced the largest and most consistent ablation volumes, with a mean volume of 12.8 ± 2.6 cm³ and average dimensions of 3.7 × 2.7 cm in under 6 min. Increasing exposure length beyond 1.5 cm introduced greater variability and reduced treatment volumes. Conclusions: INSPIRE enables safe, large-volume, single-applicator ablation without a need for electrical pulse synchronization with R wave in cardiac rhythm. The 1.5 cm exposure length offers optimal balance between energy delivery and treatment consistency. These findings support further clinical investigation of INSPIRE for non-thermal ablation of inoperable tumors. Full article

The uptake and translocation of Pb, Cr, Cd, and Zn in tomato plants (Solanum lycopersicum L. Rally) were investigated. Tomato seedlings were grown for five weeks in pots containing 40 L of Hoagland nutrient solution (pH 7) or contaminated nutrient solutions at two concentration levels for each element: Cr (100 and 1000 ng/mL), Zn (100 and 1000 ng/mL), Pb (100 and 500 ng/mL), and Cd (50 and 500 ng/mL). The solutions were replenished weekly to maintain a volume of 40 L (pH 7), and 10 mL samples were collected for elemental analysis. After five weeks, the plants were harvested and separated into roots, stems, leaves, and fruits. These samples underwent microwave-assisted digestion, and the element concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS). The results revealed that the elements were mainly accumulated in the roots, with much lower concentrations determined in the fruits. Pb and Cr accumulated only minimally in fruits, with Pb levels of 0.0009 mg/kg wet weight at LI and 0.003 mg/kg wet weight at LII, and Cr levels of 0.028 mg/kg wet weight at LI and 0.031 mg/kg wet weight at LII. The Pb levels did not exceed the permissible limits set by EC regulations (0.05 mg/kg wet weight). Zn exhibited the highest accumulation in fruits, with 2.17 mg/kg wet weight at LI and 4.8 mg/kg wet weight at LII. By contrast, the Cd concentrations in fruits (0.25 mg/kg wet weight at LI and 1.1 mg/kg wet weight at LII) exceeded the EC regulatory limit of 0.02 mg/kg wet weight. The uptake of other essential elements into the tomato plant remained largely unaffected by the presence of contaminants. These results provide valuable insights into food safety. Laser ablation (LA)-ICP-MS imaging revealed an even distribution of Cd and Zn in the leaves of plants grown in contaminated nutrient solutions. By contrast, Cr and Pb were predominantly localized in the leaf veins and at the leaf apex, suggesting different transport mechanisms for these elements from the roots to the aerial parts of the plant. Full article

Background/Objectives: Benign prostatic hyperplasia (BPH) is a prevalent condition in aging men and a major cause of lower urinary tract symptoms (LUTSs). While traditional treatments such as transurethral resection of the prostate (TURP) are effective, they are associated with notable morbidity. Ultrasound-guided transperineal laser ablation (TPLA) has emerged as a minimally invasive alternative. This study aimed to assess the 12-month efficacy, safety, and functional outcomes of TPLA in patients with LUTS secondary to BPH. Methods: This was a single-center, retrospective observational cohort study including 53 patients with moderate-to-severe LUTS due to BPH who underwent TPLA between November 2021 and May 2024. Baseline and follow-up assessments were conducted at 1, 3, 6, and 12 months, including IPSS, Qmax, PVR, prostate volume (MRI), QoL, IIEF-5, and MSHQ-ED/Bother scores. The procedure was performed under local anesthesia using the EchoLaser™ system, and ablation was guided via real-time transrectal ultrasonography. Results: Statistically significant improvements were observed in IPSS (median decrease from 30 to 13), Qmax (5.5 to 13.0 mL/s), and PVR (200 to 85 mL). Prostate and adenoma volumes decreased by 41.2% and 58.3%, respectively. Quality of life scores improved, and erectile function remained stable. Ejaculatory function improved significantly based on MSHQ-ED and MSHQ-Bother scores. No major complications or conversions to surgery occurred. Conclusions: TPLA appears to be a safe, effective, and minimally invasive treatment modality for LUTS caused by BPH. It offers sustained symptomatic relief, prostate volume reduction, and preservation of sexual function, making it a promising alternative for patients unfit or unwilling to undergo invasive surgery. Full article

Glacial-lake outburst floods (GLOFs) threaten more than three million residents of south-east Kazakhstan, yet quantitative data on lake growth and storage are scarce. We inventoried 154 lakes on the northern flank of the Ile-Alatau and selected four moraine-dammed basins with the greatest historical flood activity for detailed study. Annual lake outlines (2016–2023) were extracted from 3 m PlanetScope imagery with a Normalised Difference Water Index workflow, while late-ablation echo-sounder surveys (2023–2024) yielded sub-metre bathymetric grids. A regionally calibrated area–volume power law translated each shoreline to water storage, and field volumes served as an independent accuracy check. The lakes display divergent trajectories. Rapid thermokarst development led to a 37% increase in the surface area of Lake 13bis, expanding from 0.039 km² to 0.054 km² over a 5-year period. In contrast, engineering-induced drawdown resulted in a 44% reduction in the area of Lake 6, from 0.019 km² to 0.011 km². Lakes 5 and 2, which are supplied by actively retreating glaciers, exhibited surface area increases of 4.8% and 15%, expanding from 0.077 km² to 0.088 km² and from 0.061 km² to 0.070 km², respectively. The empirical model reproduces field volumes to within ±25% for four lakes, confirming its utility for rapid hazard screening, but overestimates storage in low-relief basins and underestimates artificially drained lakes. This is the first study in Ile-Alatau to fuse daily 3 m multispectral imagery with ground-truth bathymetry, delivering an 8-year, volume-resolved record of lake evolution. The results identify Lake 5 and Lake 2 as priority targets for early-warning systems and demonstrate that sustained intervention can effectively suppress GLOF risk. Incorporating these storage trajectories into regional disaster plans will sharpen evacuation mapping, optimise resource allocation, and inform transboundary water-hazard policy under accelerating climate change. Full article