Search Results (1,271)

An integrated evaluation framework merging the analytic hierarchy process (AHP) and an improved matter–element extension model based on asymmetric proximity is developed to classify large deformation risk levels in soft-rock tunnel construction. From geological surveys and real-time monitoring, ten core indicators spanning three dimensions—geology (surrounding rock grade, groundwater condition, strength–stress ratio, adverse geological condition), design (excavation cross-sectional shape, excavation span, excavation cross-sectional area), and support (support stiffness, support installation timing, construction step length)—are selected. AHP constructs and validates a judgment matrix to derive subjective weights for each indicator. Within a three-tier hierarchy (indicator, criterion, and target layers), the asymmetric proximity quantifies each tunnel’s proximity to the matter–element representing predefined risk levels. Risk levels are then automatically assigned by selecting the maximum composite proximity. Application to representative soft-rock tunnel cases confirms the method’s high accuracy, stability, and operational feasibility, closely matching field observations. This framework enables precise risk stratification and intuitive visualization, offering critical technical support for optimizing tunnel design and operations, and ultimately enhancing the safety, resilience, and sustainability of large-scale infrastructure. Full article

Poly(L-lactide) (PLA) is a promising biopolymer for biomedical applications due to its biodegradability and biocompatibility; however, its brittleness restricts its use in fused deposition modeling (FDM). To overcome this limitation, flexible PLA monofilaments with enhanced mechanical performance and printability were developed. In this study, PLA was melt-blended with acetyl triethyl citrate (ATEC, 1.0–5.0 wt%) as a plasticizer and zinc phenyl phosphonate (TMC-200, 0.3 wt%) as a nucleating agent. It was found that the PLA with 3.0 wt% ATEC (PLA/A) exhibited the greatest flexibility, while the addition of TMC-200 further improved tensile strength and ductility. Specifically, the ternary blend of PLA/TMC-200/ATEC (PLA/T/A) exhibited a synergistic effect, achieving superior mechanical properties (tensile strength: 35.0 MPa, elongation at break: 232.0%, compared to 12.1% for pure PLA) and raising the degree of crystallinity (X_c) from 4.7% to 45.0%. Monofilaments (1.70 ± 0.05 mm) fabricated from PLA/T/A exhibited smooth surfaces, balanced mechanical performance, and excellent cytocompatibility (over 99% cell viability in L929 fibroblasts). Moreover, FDM-printed specimens retained enhanced mechanical and thermal performance, demonstrating material stability after processing. Shelf-life testing further confirmed the structural integrity of PLA/T/A monofilament after 8 weeks at 50 °C. Overall, PLA/T/A provides an effective strategy for producing high-performance, medical-grade PLA monofilaments with improved toughness, printability, and biocompatibility, enabling their application in biomedical 3D printing. Full article

The reclamation of exhausted open-pit coal mines is an energy-intensive and costly process. Traditional methods offer no economic return. This study explores the feasibility of using autonomous electric dump trucks (EDTs) to fill the pit, leveraging regenerative braking during descent to generate energy and reduce operational costs. A comprehensive energy balance model was developed based on the operational cycle of the Komatsu HD605-7 (E-Dumper) in the unique downhill-loaded logistics of the Pery quarry. The model incorporates vehicle dynamics equations, including rolling resistance, gradient, and aerodynamic forces, to calculate net energy consumption per cycle. Three energy storage system (ESS) configurations were compared: NMC/NCA batteries, LiFePO₄ (LFP) batteries, and a hybrid LFP + supercapacitor (SC) system. Simulation results demonstrate that the net energy per cycle decreases with increasing payload capacity, even becoming negative (net energy generation) for loads above 110 tons due to powerful regenerative braking on the 13% descent grade. The hybrid LFP + SC system proved most efficient, achieving the lowest specific energy consumption (kWh/ton) by effectively capturing high-power regenerative currents. While LFP batteries have a lower energy density, their superior cycle life, thermal stability, and safety make them the optimal choice for the harsh mining environment. The proposed operation strategy, utilizing EDTs in a downhill-loaded cycle, transforms mine reclamation from a cost center into a potentially energy-neutral or even energy-positive process. A hybrid ESS with LFP batteries and supercapacitors is recommended as the most reliable and efficient solution for this specific application. Full article

Despite advances in modern medicine and increased public awareness, cerebral stroke remains a leading cause of death and long-term disability worldwide. With over 600,000 new cases annually, innovative therapeutic strategies are being explored to enhance recovery outcomes. One promising approach is the use of human stem cell-derived extracellular vesicles (EVs), particularly exosomes, which function as mediators of intercellular communication. EVs have emerged as pivotal mediators of intercellular communication with immense potential in therapeutic applications. This review discusses the pioneering journey of EVs from their biogenesis and molecular cargo loading to their translation into clinical strategies for cerebral ischemic stroke therapy. While direct stem cell transplantation has faced limitations such as immune rejection, tumorigenicity, and short shelf life, human stem cell-derived EVs offer a cell-free alternative with enhanced safety, stability, and functional versatility. Preclinical studies reveal their capacity to modulate inflammation, protect neural tissue, and promote recovery through the transfer of bioactive molecules. Additionally, EVs isolated from biofluids such as blood and cerebrospinal fluid serve as promising biomarkers for stroke severity and prognosis. Despite this promise, several challenges persist—from standardizing isolation techniques and optimizing therapeutic cargo to scaling up production for clinical-grade use. This review critically examines the current understanding of EV biology, highlights the advances in stroke-related applications, and outlines key hurdles that must be addressed to unlock their full therapeutic potential. Full article

Background/Objectives: Knee osteoarthritis (OA) is a prevalent degenerative joint disorder associated with pain, impaired proprioception, and reduced physical function. While closed kinetic chain exercises (CKCEs) are commonly prescribed to enhance joint stability, their weight-bearing nature may exacerbate symptoms. Graded weight-bearing exercises (GWBEs) using anti-gravity treadmill training provide a novel approach to reduce joint loading while maintaining functional mobility. This study aimed to evaluate the effectiveness of GWBEs compared with CKCEs and open kinetic chain exercises (OKCEs) on pain, function, proprioception, and quadricep strength in patients with knee OA. Methods: Forty-five adults aged 40–60 years with radiographically confirmed knee OA were randomized into three groups: (1) GWBE + OKCE, (2) CKCE + OKCE, or (3) OKCE alone. Interventions were conducted three times per week for six-weeks. Outcomes included pain (Visual Analogue Scale), physical function (Western Ontario and McMaster Universities Osteoarthritis Index, 6-Minute Walk Test), proprioception (joint repositioning error at 45°), and quadriceps strength (isokinetic peak torque at 60°, 120°, and 180°/s). Results: All groups demonstrated significant improvements in pain and function (p < 0.05). Proprioception improved in the GWBE + OKCE and CKCE + OKCE groups but not in the OKCE group. No significant changes were observed in quadriceps strength across groups. The GWBE + OKCE group showed significantly greater improvements in pain, function, and proprioception compared to both comparator groups (p < 0.05). Conclusions: GWBE combined with OKCE is more effective than CKCE + OKCE and OKCE alone in improving pain, function, and proprioception in patients with knee OA. Full article

Crystal grain size control in steel is critical for achieving mechanical properties. This study investigates the effectiveness of microalloying with titanium, niobium, zirconium, and yttrium to inhibit grain growth with the pinning effect. The comparison of selected microalloying elements in the exact same conditions is crucial for understanding their effect and is novel. Hot-rolled samples were annealed across a wide range of temperatures (1050 to 1200 °C) for up to eight hours. Microstructural analysis confirmed the presence of stable precipitates and non-metallic inclusions such as Nb(C,N), Ti(C,N), ZrO₂, and Y₂O₃ acting as obstacles to grain boundary migration. All microalloying elements significantly outperformed the reference steel, but their effectiveness was highly dependent on the annealing temperature. Titanium was the most effective inhibitor at lower temperatures (1050 °C), while zirconium maintained control up to 1150 °C. Critically, at the highest temperature of 1200 °C, only the yttrium-alloyed steel retained a fine-grain structure, demonstrating superior thermal stability. Niobium, conversely, only showed a minimal effect at 1050 °C, though this grade also exhibited the highest hardness (up to 165 HB) due to precipitation hardening. The kinetics of grain growth were successfully modeled using the Arrhenius-type Sellars–Whiteman equation, accurately describing the behavior for up to four hours of annealing. The findings provide critical insight for selecting optimal microalloying strategies based on maximum operating temperature. Full article

Sirtuin 1 (SIRT1), an NAD⁺-dependent histone deacetylase, exerts complex and context-dependent effects in breast and gynecological cancers. By deacetylating histone and non-histone proteins such as p53, FOXO, and NF-κB, SIRT1 regulates essential processes including DNA repair, apoptosis, metabolism, and stress response. In breast cancer, SIRT1 may act as a tumor suppressor in early stages by maintaining genomic stability but promotes epithelial–mesenchymal transition, metastasis, and chemoresistance in aggressive subtypes such as triple-negative breast cancer. Similarly, in gynecological cancers, SIRT1 displays dual roles: promoting proliferation via estrogen signaling and p53/FOXO1 inhibition in Type I endometrial cancer yet potentially supporting DNA repair in high-grade Type II tumors. Its overexpression in ovarian and cervical cancers is linked to enhanced survival and drug resistance. Preclinical studies show that pharmacological inhibition of SIRT1 (e.g., with EX-527 or cambinol) restores chemosensitivity and reduces tumor cell viability, suggesting potential for SIRT1 inhibitors as adjuncts in cancer therapy. However, clinical trials specifically targeting SIRT1 in these cancers remain limited. Further investigation is needed to define therapeutic windows, molecular contexts, and combination strategies that could optimize SIRT1-targeted therapies. This review summarizes the current understanding of SIRT1’s roles in breast and gynecologic malignancies. Full article

Objective: To identify distinct subtypes of ICU patients with Acute Kidney Injury (AKI) using serum electrolyte data and assess their associations with in-hospital mortality risk. Methods: This study used the eICU Collaborative Research Database (eICU-CRD) as its primary data source. AKI patients were identified according to the KDIGO clinical practice guidelines. Using K-Medoids clustering, we identified distinct AKI subtypes based on the first serum electrolyte measurements taken within 24 h of AKI diagnosis in the ICU. Logistic regression analysis was then employed to assess associations between these subtypes and in-hospital mortality risk. Within each subtype, we further examined the relationship between two AKI-related treatments, diuretics and renal replacement therapy (RRT), and mortality risk. Finally, to validate the identified subtypes, we replicated the entire analysis using a critical care dataset from a grade A tertiary hospital in Beijing, China. Results: We identified three distinct AKI subtypes from 15,838 eligible patients in the eICU-CRD. Subtype 1 (6364 patients, 40.2%) showed the lowest risk of in-hospital death and had all serum electrolyte levels within normal ranges. Subtype 2 (6624 patients, 41.8%) carried a moderate death risk and was characterized by abnormally high chloride levels. Subtype 3 (2850 patients, 18.0%) had the highest death risk, presenting with high serum phosphate and low bicarbonate levels. Importantly, the associations between treatments and mortality risk differed significantly by subtype. In the high-risk Subtype 3, both diuretics (OR = 0.71, p = 0.010) and RRT (OR = 0.78, p = 0.045) were associated with a lower risk of in-hospital death. However, in Subtype 2, both diuretics (OR = 1.30, p = 0.044) and RRT (OR = 1.56, p = 0.003) were associated with an increased risk. Neither treatment showed a significant association with death risk in Subtype 1. These findings were validated in the critical care database (431 AKI patients) from a Chinese local hospital, where the same three subtypes emerged with consistent electrolyte patterns, death risk profiles, and associations between treatments and mortality risks, validating the stability of the identified subtypes. Conclusions: Serum electrolyte data can help identify ICU AKI subtypes with different mortality risks. Additionally, associations between treatments (diuretics and RRT) and mortality risk vary significantly across these subtypes. These results generate the hypothesis that AKI subtyping could potentially inform personalized management strategies. Full article

During water flooding processes, the high viscosity of heavy oil and significant reservoir heterogeneity often lead to severe water channeling and low sweep efficiency. Addressing the limitations of traditional hydrophobically associating polymer-based profile-control agents—such as significant adsorption loss, mechanical degradation during reservoir migration, resulting in a limited effective radius and short functional duration—this study developed a polymeric graded profile-control agent suitable for highly heterogeneous conditions. The physicochemical properties of the system were comprehensively evaluated through systematic testing of its apparent viscosity, salt tolerance, and anti-aging performance. The microscopic oil displacement mechanisms in porous media were elucidated by combining CT scanning and microfluidic visual displacement experiments. Experimental results indicate that the agent exhibits significant hydrophobic association behavior, with a critical association concentration of 1370 mg·L⁻¹, and demonstrates a “low viscosity at low temperature, high viscosity at high temperature” rheological characteristic. At a concentration of 3000 mg·L⁻¹, the apparent viscosity of the solution is 348 mPa·s at 30 °C, rising significantly to 1221 mPa·s at 70 °C. It possesses a salinity tolerance of up to 50,000 mg·L⁻¹, and a viscosity retention rate of 95.4% after 90 days of high-temperature aging, indicating good injectivity, reservoir compatibility, and thermal stability. Furthermore, within a concentration range of 500–3000 mg·L⁻¹, the agent can effectively emulsify Gudao heavy oil, forming O/W emulsion droplets with sizes ranging from 40 to 80 μm, enabling effective plugging of pore throats of corresponding sizes. CT scanning and microfluidic displacement experiments further reveal that the agent possesses a graded control function: in the near-wellbore high-concentration zone, it primarily relies on its aqueous phase viscosity-increasing capability to control the mobility ratio; upon entering the deep reservoir low-concentration zone, it utilizes “emulsion plugging” to achieve fluid diversion, thereby expanding the sweep volume and extending the effective treatment period. This research outcome provides a new technical pathway for the efficient development of highly heterogeneous heavy oil reservoirs. Full article

Background/Objectives: Whole-gland surgery or radiotherapy for localized prostate cancer (PCa) can cure the disease but often impair urinary and sexual function. Focal therapy with high-intensity focused ultrasound (HIFU) seeks to eradicate the tumor while sparing uninvolved tissue. We prospectively evaluated oncological control, functional outcomes and safety of MRI-guided focal HIFU in patients with low- or intermediate-risk PCa. Methods: In this prospective, single-arm, phase II feasibility trial (three Austrian centres, 2021–2024), treatment-naive patients with D’Amico low/intermediate-risk, PSA ≤ 15 ng/mL, clinical stage ≤ T2 and MRI-targeted, biopsy-confirmed index lesions underwent lesion-targeted HIFU (Focal One™). The primary endpoint was failure-free survival (FFS: absence of salvage whole-gland or systemic therapy, metastasis or PCa-specific death). Secondary endpoints included biopsy-proven cancer, prostate-specific antigen (PSA), patient-reported symptoms as International Prostate Symptom Score (IPSS), 5-item International Index of Erectile Function (IIEF), Gaudenz Incontinence Questionnaire and adverse events. Planned follow-up was 24 months with PSA every 3 months, mpMRI and biopsies at 12 months, and imaging- or PSA-triggered biopsies thereafter. Results: Fifty-one men were analysed in the per-protocol cohort (median age 67 years, median PSA 7.55 ng/mL). Median treated volume was 12 mL; median procedure time 85 min. At 24 months, FFS was 94.1%: 3/51 patients (5.9%) required salvage radiotherapy. Among 31 patients who underwent follow-up biopsy, 26 (83.9%) had no cancer; the five positives included three ISUP 1, one ISUP2 and one ISUP 4 lesion. Mean PSA fell by 69% at 3 months (to 2.3 ng/mL) and then stabilized under 3 ng/mL, with a mean of 2.7 ± 1.5 ng/mL at 24 months. Transient acute urinary retention occurred in 11/51 (21.6%); no Clavien–Dindo grade ≥ 4 events were reported. IPSS returned to or improved beyond baseline, erectile function largely recovered by 6–12 months, and only one new case of grade 2 incontinence was observed. Conclusions: MRI-guided focal HIFU achieved high two-year failure-free survival with low morbidity and preserved quality of life in carefully selected patients with low- or intermediate-risk PCa. These data support further randomized and longer-term investigations of focal HIFU as an organ-sparing alternative to whole-gland treatment. Full article

Primary meningeal melanocytoma is an uncommon, pigmented neoplasm that rarely undergoes malignant transformation, and therapeutic guidelines remain undefined. We report a 43-year-old woman who initially presented with a sudden headache and a right temporal intraparenchymal mass. Subtotal resection revealed a melanocytoma (WHO grade I); residual tumor was treated with Gamma Knife. About 15 months later, she deteriorated rapidly due to malignant transformation with cerebral hemorrhage and spinal leptomeningeal metastasis. Pembrolizumab was initiated within four weeks of the malignant diagnosis and produced transient neurological improvement. Due to symptomatic progression, ipilimumab plus nivolumab was commenced and achieved temporary radiographic stabilization, but the patient succumbed to diffuse progression later. Including this case, only five intracranial melanocytomas with malignant transformation treated with immune checkpoint inhibitors have been reported. Our experience supports initiating immunotherapy promptly after malignant transformation and suggests that sequential dual-agent blockade may modestly extend disease control. Full article

Cement-stabilized macadam often shows salt expansion deformation under the action of a sulfate attack, and its pore structure determines its ability to accommodate this deformation. In this paper, the influence of the pore structure of cement-stabilized macadam on its macroscopic deformation is analyzed using a single-grain salt expansion deformation test, scanning electron microscopy (SEM), and computerized tomography (CT) scanning. The results show that ettringite and sodium sulfate decahydrate crystals are key factors in salt expansion deformation. In addition, we find that when the sulfate content increases from 0% to 5%, the porosity of the mixture decreases by 1.5%, the proportion of primary pores increases by 12.1%, and the linear expansion rate increases by 0.05%. Finally, a salt expansion deformation prediction model for cement-stabilized macadam is proposed, which takes the porosity of the mixture, the proportion of graded pores, and the deformation influence factor as parameters, and the error is found to be less than 10%. Full article

Study develops and field-validates a SCADA-based real-time monitoring system to reduce unplanned dilution and hanging-wall over-break in underground long-hole stoping at a Zimbabwean gold mine. The objectives were to detect and constrain drilling deviation in real time, quantify the impact on stope stability and dilution, and evaluate operational and economic effects. The system integrates IMU inclinometers (hole angle), rotary encoders (depth), and LiDAR (collar spacing) with a Siemens S7 PLC (RS Americas, Fort Worth, TX, USA) and AVEVA™ InTouch HMI 2023 R2. Field trials across three production stopes (12L, 14L, 15L) compared baseline manual monitoring to SCADA control. Mean angular deviation fell from 0.8–1.6° to 0.2–0.3°, length deviation from 0.8–1.1 m to 0.05–0.08 m, and positional error from 0.25–0.32 m to 0.04–0.06 m; major collapses were eliminated, and ELOS dropped (e.g., 0.20 m to 0.05 m). Dilution decreased from 25% (typical 21–26%) to 16–18%, with mill feed grade rising from 1.90 to 2.25 g/t; production rates were maintained, with brief auto-stops in 5% of holes and rapid operator correction. Real-time drilling control materially reduces unplanned dilution and improves wall stability without productivity penalties, yielding compelling economics. Full article

The evolving bitumen market is increasingly complex due to variations in crude sources and transitions in refining processes, affecting the properties of bitumen. Unexpected additions of materials to alter bitumen’s properties could occur, where traditional PEN grade testing fails to detect modifications by inclusion of, for example, Re-refined Engine Oil Bottoms. This is the first study to comprehensively compare REOBs from European vs. North American sources and assess their effects on binder performance in a unified framework, performed by assessing the REOB-modified binders by identification, stability, compatibility, ageing susceptibility, and low-temperature properties. Two series of REOB-modified bitumen were prepared by blending 5, 10, and 15 wt.% REOB into hard grade bitumen. Results showed increased carbonyl formations (likely caused by lubricant additives) and phase instability during storage which can be attributed to saturates exudation. Rheological assessment demonstrated that REOB softens bitumen, although ageing causes a pronounced gain in stiffness. Low temperature rheological measurements showed that REOB-modified bitumen is prone to brittle fracture, suggesting a loss of relaxation properties. This study highlights that REOB is a material of inconsistent nature, with complex interactions with molecular groups of the base bitumen, causing increased ageing, phase instability, and brittle fracture susceptibilities. Full article

The conversion of low-grade heat into storable electrical energy using nanoporous carbon materials represents an efficient energy harvesting strategy. In this study, a reduced graphene oxide (RGO) and carbon nanotube (CNT) composite with a rich microporous structure was synthesized. A symmetrical thermoelectric cell was constructed to harvest thermal energy. The application of a temperature difference (ΔT) generated a stable equilibrium voltage (U_s), which scaled linearly with ΔT. The resulting thermoelectric coefficient (U_s/ΔT) increased markedly with the carbon nanotube (CNT) content, underscoring the effectiveness of CNT incorporation for improving thermoelectric properties. It also shows a non-monotonic dependence on KCl concentration, first increasing and then decreasing, with a maximum value of 4.17 mV/°C achieved in 0.1 M KCl using the RGO-5%CNTs electrode. When connected to an external load, the discharge voltage and current decay rapidly before stabilizing within seconds. Circuit analysis reveals that the incorporation of CNTs reduces internal resistance and increases the equivalent capacitance. Although instantaneous discharge power declines quickly, the addition of CNTs elevates its initial value and slows the decay rate. Both the average output power and thermoelectric conversion efficiency improve with increasing ΔT and are further enhanced at higher CNT content. Overall, the RGO-CNT composite demonstrates significantly superior thermoelectric performance compared to pure RGO. Full article