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Search Results (1,195)

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17 pages, 675 KB  
Systematic Review
Stereotactic Radiosurgery for Recurrent Meningioma: A Systematic Review of Risk Factors and Management Approaches
by Yuka Mizutani, Yusuke S. Hori, Paul M. Harary, Fred C. Lam, Deyaaldeen Abu Reesh, Sara C. Emrich, Louisa Ustrzynski, Armine Tayag, David J. Park and Steven D. Chang
Cancers 2025, 17(17), 2750; https://doi.org/10.3390/cancers17172750 - 23 Aug 2025
Viewed by 56
Abstract
Background/Objectives: Recurrent meningiomas remain difficult to manage due to the absence of effective systemic therapies and comparatively high treatment failure rates, particularly in high-grade tumors. Stereotactic radiosurgery (SRS) offers a minimally-invasive and precise option, particularly for tumors in surgically complex locations. However, [...] Read more.
Background/Objectives: Recurrent meningiomas remain difficult to manage due to the absence of effective systemic therapies and comparatively high treatment failure rates, particularly in high-grade tumors. Stereotactic radiosurgery (SRS) offers a minimally-invasive and precise option, particularly for tumors in surgically complex locations. However, the risks associated with re-irradiation, and recent changes in the WHO classification of CNS tumors highlight the need for more personalized and strategic treatment approaches. This systematic review evaluates the safety, efficacy, and clinical considerations for use of SRS for recurrent meningiomas. Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature search was conducted using the PubMed, Scopus, and Web of Science databases for studies reporting outcomes of SRS in recurrent, pathologically confirmed intracranial meningiomas. Studies were excluded if they were commentaries, reviews, case reports with fewer than three cases, or had inaccessible full text. The quality and risk of bias of the included studies were assessed using the modified Newcastle-Ottawa Scale. Data on patient and tumor characteristics, SRS treatment parameters, clinical outcomes, adverse effects, and statistical analysis results were extracted. Results: Sixteen studies were included. For WHO Grade I tumors, 3- to 5-year progression-free survival (PFS) ranged from 85% to 100%. Grade II meningiomas demonstrated more variable outcomes, with 3-year PFS ranging from 23% to 100%. Grade III tumors had consistently poorer outcomes, with reported 1-year and 2-year PFS rates as low as 0% and 46%, respectively. SRS performed after surgery alone was associated with superior outcomes, with local control rates of 79% to 100% and 5-year PFS ranging from 40.4% to 91%. In contrast, tumors previously treated with radiotherapy, with or without surgery, showed substantially poorer outcomes, with 3- to 5-year PFS ranging from 26% to 41% and local control rates as low as 31%. Among patients with prior radiotherapy, outcomes were particularly poor in Grade II and III recurrent tumors. Toxicity rates ranged from 3.7% to 37%, and were generally higher for patients with prior radiation. Predictors of worse PFS included prior radiation, older age, and Grade III histology. Conclusions: SRS may represent a reasonable salvage option for carefully selected patients with recurrent meningioma, particularly following surgery alone. Outcomes were notably worse in high-grade recurrent meningiomas following prior radiotherapy, emphasizing the prognostic significance of both histological grade and treatment history. Notably, the lack of molecular and genetic data in most existing studies represents a key limitation in the current literature. Future prospective studies incorporating molecular profiling may improve risk stratification and support more personalized treatment strategies. Full article
(This article belongs to the Special Issue Meningioma Recurrences: Risk Factors and Management)
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14 pages, 2382 KB  
Article
Research on Viscous Dissipation Index Assessment of Polymer Materials Using High-Frequency Focused Ultrasound
by Zeqiu Yang, Yuebing Wang and Zhenwei Lu
Appl. Sci. 2025, 15(17), 9267; https://doi.org/10.3390/app15179267 - 22 Aug 2025
Viewed by 229
Abstract
Polymer viscoelasticity is crucial for mechanical performance, but conventional low-frequency methods struggle to isolate viscous loss—a key viscosity indicator. This study introduces a high-frequency ultrasonic method to differentiate the polymer viscous dissipation index by analyzing acoustic phase shifts. We employ ultrasonic phase-shift thermometry [...] Read more.
Polymer viscoelasticity is crucial for mechanical performance, but conventional low-frequency methods struggle to isolate viscous loss—a key viscosity indicator. This study introduces a high-frequency ultrasonic method to differentiate the polymer viscous dissipation index by analyzing acoustic phase shifts. We employ ultrasonic phase-shift thermometry to measure localized temperature increases resulting from minute variations in sound velocity during controlled heating. This allows for the quantification of viscous loss, which is then used to distinguish between different polymer formulations. Experimental and simulation results on a series of polyurethane specimens with varying Shore hardness levels demonstrate that decawatt-range (10–20 W) ultrasonic irradiation enables sensitive and precise differentiation. Notably, the Shore A70 polyurethane sample exhibited a significantly higher viscous dissipation index, evidenced by the largest temperature rise (27.5 °C) and the highest proportion of viscous heating to total power dissipation (93.1%) under 17 W acoustic irradiation. While this study focuses on commercially available polymers, the method can be extended to evaluate key performance parameters, such as tensile modulus and glass transition temperature, in polymers fabricated under various processing conditions, thereby offering a powerful tool for material quality assessment. Full article
(This article belongs to the Section Acoustics and Vibrations)
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16 pages, 7082 KB  
Article
Ultrasound-Responsive Drug Delivery System Based on Piezoelectric Catalytic Mechanisms
by Kaixi Cui, Tianzheng Li, Yifei Ma, Chuanjin Zhang, Ke Zhang, Chao Qi and Kaiyong Cai
J. Funct. Biomater. 2025, 16(8), 304; https://doi.org/10.3390/jfb16080304 - 21 Aug 2025
Viewed by 238
Abstract
Ultrasound-responsive nanomaterials represent a promising approach for achieving non-invasive and localized drug delivery within tumor microenvironments. In this study, we developed a piezocatalysis-assisted hydrogel system that integrates reactive oxygen species (ROS) generation with stimulus-responsive drug release. The platform combines piezoelectric barium titanate (BTO) [...] Read more.
Ultrasound-responsive nanomaterials represent a promising approach for achieving non-invasive and localized drug delivery within tumor microenvironments. In this study, we developed a piezocatalysis-assisted hydrogel system that integrates reactive oxygen species (ROS) generation with stimulus-responsive drug release. The platform combines piezoelectric barium titanate (BTO) nanoparticles with a ROS-sensitive hydrogel matrix, forming an ultrasound-activated dual-function therapeutic system. Upon ultrasound irradiation, the BTO nanoparticles generate ROS—predominantly hydroxyl radicals (OH) and singlet oxygen (1O2)—through the piezoelectric effect, which triggers hydrogel degradation and facilitates the controlled release of encapsulated therapeutic agents. The composition and kinetics of ROS generation were evaluated using radical scavenging assays and fluorescence probe techniques, while the drug release behavior was validated under simulated oxidative environments and acoustic fields. Structural and compositional characterizations (TEM, XRD, and XPS) confirmed the quality and stability of the nanoparticles, and cytocompatibility was assessed using 3T3 fibroblasts. This synergistic strategy, combining piezocatalytic ROS generation with hydrogel disintegration, demonstrates a feasible approach for designing responsive nanoplatforms in ultrasound-mediated drug delivery systems. Full article
(This article belongs to the Special Issue Biomaterials for Drug Delivery and Cancer Therapy)
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16 pages, 2363 KB  
Article
The Involvement of the S2P2 Intramembrane Protease in the Response of Arabidopsis thaliana Chloroplasts to High Light Stress
by Maria Ciesielska, Małgorzata Adamiec and Robert Luciński
Plants 2025, 14(16), 2584; https://doi.org/10.3390/plants14162584 - 20 Aug 2025
Viewed by 212
Abstract
High light intensity constitutes a critical abiotic stress factor that profoundly affects the structural and functional integrity of the photosynthetic apparatus. Excessive irradiance triggers accelerated degradation of the PsbA polypeptide, increases susceptibility to photoinhibition, and promotes overproduction of reactive oxygen species (ROS), thereby [...] Read more.
High light intensity constitutes a critical abiotic stress factor that profoundly affects the structural and functional integrity of the photosynthetic apparatus. Excessive irradiance triggers accelerated degradation of the PsbA polypeptide, increases susceptibility to photoinhibition, and promotes overproduction of reactive oxygen species (ROS), thereby inducing oxidative damage to proteins, lipids, and nucleic acids. Among the chloroplast-localized site-2 proteases of Arabidopsis thaliana, S2P2 remains the least characterized. In this study, our analyses revealed a pronounced upregulation of the S2P2 (AT1G05140) gene and a concomitant accumulation of the S2P2 protein under high light conditions. Functional characterization using two independent S2P2 insertional mutant lines lacking the protease demonstrated that loss of S2P2 significantly exacerbates photoinhibition. Mutants exhibited reduced photosystem II (PSII) efficiency, accompanied by accelerated degradation of the PSII core proteins PsbA, PsbD, and PsbC, as well as elevated ROS generation. These findings provide the first direct evidence that S2P2 plays a pivotal role in maintaining the stoichiometric balance of PSII core components and conferring resilience of the photosynthetic machinery to high light stress. This work expands the functional repertoire of chloroplast site-2 proteases and underscores S2P2 as a potential target for improving stress tolerance in plants. Full article
(This article belongs to the Special Issue Advances in Plant Photobiology)
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22 pages, 5884 KB  
Article
From Shadows to Signatures: Interpreting Bypass Diode Faults in PV Modules Under Partial Shading Through Data-Driven Models
by Hatice Gül Sezgin-Ugranlı
Electronics 2025, 14(16), 3270; https://doi.org/10.3390/electronics14163270 - 18 Aug 2025
Viewed by 307
Abstract
Bypass diode faults are among the most hard-to-detect but impactful anomalies in photovoltaic (PV) systems, especially under partial shading conditions, where their electrical signatures often resemble those caused by non-critical irradiance variations. This study presents a systematic simulation-based investigation into how different bypass [...] Read more.
Bypass diode faults are among the most hard-to-detect but impactful anomalies in photovoltaic (PV) systems, especially under partial shading conditions, where their electrical signatures often resemble those caused by non-critical irradiance variations. This study presents a systematic simulation-based investigation into how different bypass diode fault types—short-circuited, open-circuited, and healthy—affect the electrical behavior of PV strings under diverse irradiance profiles. A high-resolution MATLAB/Simulink model is developed to simulate 27 unique diode fault configurations across multiple shading scenarios, enabling the extraction of key features from resulting I–V curves. These features include global and local maximum power point parameters, open-circuit voltage, and short-circuit current. To address the challenge of feature redundancy and classification ambiguity, a preprocessing step is applied to remove near-duplicate instances and improve model generalization. An artificial neural network (ANN) model is then trained to classify the number of faulty bypass diodes based on these features. Comparative evaluations are conducted with support vector machines and random forests. The results indicate that the ANN achieves the highest test accuracy (93.57%) and average AUC (0.9925), outperforming other classifiers in both robustness and discriminative power. These findings highlight the importance of feature-informed, data-driven approaches for fault detection in PV systems and demonstrate the feasibility of diode fault classification without precise fault localization. Full article
(This article belongs to the Special Issue Renewable Energy Power and Artificial Intelligence)
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14 pages, 4450 KB  
Article
Photothermally Responsive Biomimetic Composite Scaffolds Based on Polydopamine-Functionalized Nanoparticles/Polyurethane for Bone Repair
by Ruqing Bai, Jiaqi Chen, Ting Zhang, Tao Chen, Xiaoying Liu, Weihu Yang, Tuck-Whye Wong, Jianwei Zhang and Li Wang
J. Funct. Biomater. 2025, 16(8), 294; https://doi.org/10.3390/jfb16080294 - 15 Aug 2025
Viewed by 524
Abstract
In this study, a shape-changeable 3D scaffold with photothermal effects was developed to address the clinical challenges of complex bone defects. The multifunctional construct was fabricated via in situ polymerization combined with a gas foaming technique, creating hierarchical porous architectures that mimic the [...] Read more.
In this study, a shape-changeable 3D scaffold with photothermal effects was developed to address the clinical challenges of complex bone defects. The multifunctional construct was fabricated via in situ polymerization combined with a gas foaming technique, creating hierarchical porous architectures that mimic the native bone extracellular matrix. By incorporating polydopamine (PDA)-modified amorphous calcium phosphate (CA) into poly(propylene glycol) (PPG)- and poly(ԑ-caprolactone) (PCL)-based polyurethane (PU). The obtained scaffolds achieved osteoinductive potential for bone tissue engineering. The surface PDA modification of CA enabled efficient photothermal shape conversion under near-infrared (NIR) irradiation, facilitating non-invasive remote control of localized hyperthermia. The optimized scaffolds exhibited interconnected porosity (approximately 70%) with osteoconductive pore channels (200–500 μm), resulting in good osteoinduction in cell culture, and precise shape-memory recovery at physiological temperatures (~40 °C) under NIR for minimally invasive delivery. The synergistic effect of osteogenesis promotion and photothermal transition demonstrated this programmable scaffold as a promising solution for integrated minimally invasive bone repair and defect reconstruction. Full article
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22 pages, 2811 KB  
Article
Deep Feature Selection of Meteorological Variables for LSTM-Based PV Power Forecasting in High-Dimensional Time-Series Data
by Husein Mauladdawilah, Mohammed Balfaqih, Zain Balfagih, María del Carmen Pegalajar and Eulalia Jadraque Gago
Algorithms 2025, 18(8), 496; https://doi.org/10.3390/a18080496 - 10 Aug 2025
Viewed by 409
Abstract
Accurate photovoltaic (PV) power forecasting is essential for grid integration, particularly in maritime climates with dynamic weather patterns. This study addresses high-dimensional meteorological data challenges by systematically evaluating 32 variables across four categories (solar irradiance, temperature, atmospheric, hydrometeorological) for day-ahead PV forecasting using [...] Read more.
Accurate photovoltaic (PV) power forecasting is essential for grid integration, particularly in maritime climates with dynamic weather patterns. This study addresses high-dimensional meteorological data challenges by systematically evaluating 32 variables across four categories (solar irradiance, temperature, atmospheric, hydrometeorological) for day-ahead PV forecasting using long short-term memory (LSTM) networks. Using six years of data from a 350 kWp solar farm in Scotland, we compare satellite-derived data and local weather station measurements. Surprisingly, downward thermal infrared flux—capturing persistent atmospheric moisture and cloud properties in maritime climates—emerged as the most influential predictor despite low correlation (1.93%). When paired with precipitation data, this two-variable combination achieved 99.81% R2, outperforming complex multi-variable models. Satellite data consistently surpassed ground measurements, with 9 of the top 10 predictors being satellite derived. Our approach reduces model complexity while improving forecasting accuracy, providing practical solutions for energy systems. Full article
(This article belongs to the Special Issue Algorithms for Feature Selection (3rd Edition))
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13 pages, 3882 KB  
Article
Thermal Damage Characterization of Detector Induced by Nanosecond Pulsed Laser Irradiation
by Zhilong Jian, Weijing Zhou, Hao Chang, Yingjie Ma, Xiaoyuan Quan and Zikang Wang
Photonics 2025, 12(8), 790; https://doi.org/10.3390/photonics12080790 - 5 Aug 2025
Viewed by 330
Abstract
Experimental and simulation analysis was conducted on the effects of 532 nm nanosecond laser-induced thermal damage on the front-side illuminated CMOS detector. The study examined CMOS detector output images at different stages of damage, including point damage, line damage, and complete failure, and [...] Read more.
Experimental and simulation analysis was conducted on the effects of 532 nm nanosecond laser-induced thermal damage on the front-side illuminated CMOS detector. The study examined CMOS detector output images at different stages of damage, including point damage, line damage, and complete failure, and correlated these with microscopic structural changes observed through optical and scanning electron microscopy. A finite element model was used to study the thermal–mechanical coupling effect during laser irradiation. The results indicated that at a laser energy density of 78.9 mJ/cm2, localized melting occurs within photosensitive units in the epitaxial layer, manifesting as an irreversible white bright spot appearing in the detector output image (point damage). When the energy density is further increased to 241.9 mJ/cm2, metal routings across multiple pixel units melt, resulting in horizontal and vertical black lines in the output image (line damage). Upon reaching 2005.4 mJ/cm2, the entire sensor area failed to output any valid image due to thermal stress-induced delamination of the silicon dioxide insulation layer, with cracks propagating to the metal routing and epitaxial layers, ultimately causing structural deformation and device failure (complete failure). Full article
(This article belongs to the Section Lasers, Light Sources and Sensors)
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18 pages, 4279 KB  
Article
Chemophotothermal Combined Therapy with 5-Fluorouracil and Branched Gold Nanoshell Hyperthermia Induced a Reduction in Tumor Size in a Xenograft Colon Cancer Model
by Sarah Eliuth Ochoa-Hugo, Karla Valdivia-Aviña, Yanet Karina Gutiérrez-Mercado, Alejandro Arturo Canales-Aguirre, Verónica Chaparro-Huerta, Adriana Aguilar-Lemarroy, Luis Felipe Jave-Suárez, Mario Eduardo Cano-González, Antonio Topete, Andrea Molina-Pineda and Rodolfo Hernández-Gutiérrez
Pharmaceutics 2025, 17(8), 988; https://doi.org/10.3390/pharmaceutics17080988 - 30 Jul 2025
Viewed by 770
Abstract
Background/Objectives: The heterogeneity of cancer disease and the frequent ineffectiveness and resistance observed with currently available treatments highlight the importance of developing new antitumor therapies. The properties of gold nanoparticles, such as their photon-energy heating, are attractive for oncology therapy; this can [...] Read more.
Background/Objectives: The heterogeneity of cancer disease and the frequent ineffectiveness and resistance observed with currently available treatments highlight the importance of developing new antitumor therapies. The properties of gold nanoparticles, such as their photon-energy heating, are attractive for oncology therapy; this can be effective and localized. The combination of chemotherapy and hyperthermia is promising. Our aim was to evaluate the combination therapy of photon hyperthermia with 5-fluorouracil (5-FU) both in vitro and in vivo. Methods: This study evaluated the antitumor efficacy of a combined chemo-photothermal therapy using 5-fluorouracil (5-FU) and branched gold nanoshells (BGNSs) in a colorectal cancer model. BGNSs were synthesized via a seed-mediated method and characterized by electron microscopy and UV–vis spectroscopy, revealing an average diameter of 126.3 nm and a plasmon resonance peak at 800 nm, suitable for near-infrared (NIR) photothermal applications. In vitro assays using SW620-GFP colon cancer cells demonstrated a ≥90% reduction in cell viability after 24 h of combined treatment with 5-FU and BGNS under NIR irradiation. In vivo, xenograft-bearing nude mice received weekly intratumoral administrations of the combined therapy for four weeks. The group treated with 5-FU + BGNS + NIR exhibited a final tumor volume of 0.4 mm3 on day 28, compared to 1010 mm3 in the control group, corresponding to a tumor growth inhibition (TGI) of 100.74% (p < 0.001), which indicates not only complete inhibition of tumor growth but also regression below the initial tumor volume. Thermographic imaging confirmed that localized hyperthermia reached 45 ± 0.5 °C at the tumor site. Results: These findings suggest that the combination of 5-FU and BGNS-mediated hyperthermia may offer a promising strategy for enhancing therapeutic outcomes in patients with colorectal cancer while potentially minimizing systemic toxicity. Conclusions: This study highlights the potential of integrating nanotechnology with conventional chemotherapy for more effective and targeted cancer treatment. Full article
(This article belongs to the Special Issue Advanced Nanotechnology for Combination Therapy and Diagnosis)
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13 pages, 873 KB  
Article
Recurrence Patterns, Treatment Outcomes, and Prognostic Factors of Thymic Carcinoma: A Multicenter Study
by Natsuo Tomita, Shunichi Ishihara, Yoshihito Nomoto, Akinori Takada, Katsumasa Nakamura, Kenta Konishi, Kohei Wakabayashi, Yukihiko Ohshima, Maho Yamada, Masayuki Matsuo, Masaya Ito, Katsuhiro Okuda, Taiki Takaoka, Dai Okazaki, Nozomi Kita, Seiya Takano and Akio Hiwatashi
Cancers 2025, 17(15), 2513; https://doi.org/10.3390/cancers17152513 - 30 Jul 2025
Viewed by 262
Abstract
Objectives: This multicenter study aimed to clarify the recurrence patterns; treatment outcomes; and prognostic factors of thymic carcinoma, a rare cancer. Methods: We analyzed 101 patients with thymic carcinoma who underwent multidisciplinary treatment, including radiotherapy. The median age was 62 years, with 27 [...] Read more.
Objectives: This multicenter study aimed to clarify the recurrence patterns; treatment outcomes; and prognostic factors of thymic carcinoma, a rare cancer. Methods: We analyzed 101 patients with thymic carcinoma who underwent multidisciplinary treatment, including radiotherapy. The median age was 62 years, with 27 patients in stage I–II; 44 in stage III; and 30 in stage IV by the TNM classification. Seventy-two patients underwent surgery with radiotherapy; and 29 patients underwent definitive radiotherapy. Image-guided radiotherapy (IGRT) and elective nodal irradiation (ENI) were used for 35 and 23 patients, respectively. Local recurrence-free survival (LRFS); progression-free survival (PFS); and overall survival (OS) were calculated, and univariate and multivariate analyses were performed. Results: With a median follow-up of 68 months, we observed 17 local recurrences; 27 regional recurrences; and 35 distant metastases. The 5-year LRFS; PFS; and OS were 82%, 41%, and 76%, respectively. Multivariate analysis revealed that stage was the only factor associated with LRFS; PFS; and OS (p = 0.040; p < 0.0001; and p = 0.048, respectively), while treatment modality was associated with only LRFS (p = 0.015). IGRT and ENI were also associated with LRFS (p = 0.002 and 0.013, respectively). PFS and OS of stage IV patients were comparable between the surgery with radiotherapy and definitive radiotherapy groups (p = 0.99 and 0.98, respectively). Conclusions: Our results suggest the importance of stage-specific treatment strategies rather than resectability, especially for stage IV patients. These results should be validated in a prospective study. Our results also suggest that radiotherapy methods influence recurrence Full article
(This article belongs to the Section Clinical Research of Cancer)
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10 pages, 1309 KB  
Proceeding Paper
A Sustainable Approach to Cooking: Design and Evaluation of a Sun-Tracking Concentrated Solar Stove
by Hasan Ali Khan, Malik Hassan Nawaz, Main Omair Gul and Mazhar Javed
Mater. Proc. 2025, 23(1), 4; https://doi.org/10.3390/materproc2025023004 - 29 Jul 2025
Viewed by 270
Abstract
Access to clean cooking remains a major challenge in rural and off-grid areas where traditional fuels are costly, harmful, or scarce. Solar cooking offers a sustainable solution, but many existing systems suffer from fixed positioning and low efficiency. This study presents a low-cost, [...] Read more.
Access to clean cooking remains a major challenge in rural and off-grid areas where traditional fuels are costly, harmful, or scarce. Solar cooking offers a sustainable solution, but many existing systems suffer from fixed positioning and low efficiency. This study presents a low-cost, dual-axis solar tracking parabolic dish cooker designed for such regions, featuring adjustable pot holder height and portability for ease of use. The system uses an Arduino UNO, LDR sensors, and a DC gear motor to automate sun tracking, ensuring optimal alignment throughout the day. A 0.61 m parabolic dish with ≥97% reflective silver-coated mirrors concentrates sunlight to temperatures exceeding 300 °C. Performance tests in April, June, and November showed boiling times as low as 3.37 min in high-irradiance conditions (7.66 kWh/m2/day) and 6.63 min under lower-irradiance conditions (3.86 kWh/m2/day). Compared to fixed or single-axis systems, this design achieved higher thermal efficiency and reliability, even under partially cloudy skies. Built with locally available materials, the system offers an affordable, clean, and effective cooking solution that supports energy access, health, and sustainability in underserved communities. Full article
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23 pages, 1585 KB  
Article
The Key Role of Thermal Relaxation Time on the Improved Generalized Bioheat Equation: Analytical Versus Simulated Numerical Approach
by Alexandra Maria Isabel Trefilov, Mihai Oane and Liviu Duta
Materials 2025, 18(15), 3524; https://doi.org/10.3390/ma18153524 - 27 Jul 2025
Viewed by 527
Abstract
The Pennes bioheat equation is the most widely used model for describing heat transfer in living tissue during thermal exposure. It is derived from the classical Fourier law of heat conduction and assumes energy exchange between blood vessels and surrounding tissues. The literature [...] Read more.
The Pennes bioheat equation is the most widely used model for describing heat transfer in living tissue during thermal exposure. It is derived from the classical Fourier law of heat conduction and assumes energy exchange between blood vessels and surrounding tissues. The literature presents various numerical methods for solving the bioheat equation, with exact solutions developed for different boundary conditions and geometries. However, analytical models based on this framework are rarely reported. This study aims to develop an analytical three-dimensional model using MATHEMATICA software, with subsequent mathematical validation performed through COMSOL simulations, to characterize heat transfer in biological tissues induced by laser irradiation under various therapeutic conditions. The objective is to refine the conventional bioheat equation by introducing three key improvements: (a) incorporating a non-Fourier framework for the Pennes equation, thereby accounting for the relaxation time in thermal response; (b) integrating Dirac functions and the telegraph equation into the bioheat model to simulate localized point heating of diseased tissue; and (c) deriving a closed-form analytical solution for the Pennes equation in both its classical (Fourier-based) and improved (non-Fourier-based) formulations. This paper investigates the nuanced relationship between the relaxation time parameter in the telegraph equation and the thermal relaxation time employed in the bioheat transfer equation. Considering all these aspects, the optimal thermal relaxation time determined for these simulations was 1.16 s, while the investigated thermal exposure time ranged from 0.01 s to 120 s. This study introduces a generalized version of the model, providing a more realistic representation of heat exchange between biological tissue and blood flow by accounting for non-uniform temperature distribution. It is important to note that a reasonable agreement was observed between the two modeling approaches: analytical (MATHEMATICA) and numerical (COMSOL) simulations. As a result, this research paves the way for advancements in laser-based medical treatments and thermal therapies, ultimately contributing to more optimized therapeutic outcomes. Full article
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18 pages, 1917 KB  
Article
Influence of Energetic Xe132 Ion Irradiation on Optical, Luminescent and Structural Properties of Ce-Doped Y3Al5O12 Single Crystals
by Ruslan Assylbayev, Gulnur Tursumbayeva, Guldar Baubekova, Zhakyp T. Karipbayev, Aleksei Krasnikov, Evgeni Shablonin, Gulnara M. Aralbayeva, Yevheniia Smortsova, Abdirash Akilbekov, Anatoli I. Popov and Aleksandr Lushchik
Crystals 2025, 15(8), 683; https://doi.org/10.3390/cryst15080683 - 27 Jul 2025
Viewed by 949
Abstract
The impact of 230-MeV Xe132 ion irradiation on the structural, optical, and luminescent properties of YAG:Ce single crystals is investigated over a fluence range of 1011–1014 ions/cm2. Optical absorption; cathodo-, X-ray, and photoluminescence; and X-ray diffraction are [...] Read more.
The impact of 230-MeV Xe132 ion irradiation on the structural, optical, and luminescent properties of YAG:Ce single crystals is investigated over a fluence range of 1011–1014 ions/cm2. Optical absorption; cathodo-, X-ray, and photoluminescence; and X-ray diffraction are employed to analyze radiation-induced changes. Irradiation leads to the formation of Frenkel (F, F+) and antisite defects and attenuates Ce3+ emission (via enhanced nonradiative processes and Ce3+ → Ce4+ recharging). A redistribution between the fast and slow components of the Ce3+-emission is considered. Excitation spectra show the suppression of exciton-related emission bands, as well as a shift of the excitation onset due to increased lattice disorder. XRD data confirm partial amorphization and a high level of local lattice disordering, both increasing with irradiation fluence. These findings provide insight into radiation-induced processes in YAG:Ce, which are relevant for its application in radiation–hard scintillation detectors. Full article
(This article belongs to the Special Issue Research Progress of Photoluminescent Materials)
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37 pages, 13718 KB  
Review
Photothermal and Photodynamic Strategies for Diagnosis and Therapy of Alzheimer’s Disease by Modulating Amyloid-β Aggregation
by Fengli Gao, Yupeng Hou, Yaru Wang, Linyuan Liu, Xinyao Yi and Ning Xia
Biosensors 2025, 15(8), 480; https://doi.org/10.3390/bios15080480 - 24 Jul 2025
Viewed by 686
Abstract
Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical [...] Read more.
Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical treatment and radiotherapy, phototherapy has the advantages, including short response time, significant efficacy, and minimal side effects in disease diagnosis and treatment. Recent studies have shown that local thermal energy or singlet oxygen generated by irradiating certain organic molecules or nanomaterials with specific laser wavelengths can effectively degrade Aβ aggregates and depress the generation of ROS, promoting progress in AD diagnosis and therapy. Herein, we outline the development of photothermal therapy (PTT) and photodynamic therapy (PDT) strategies for the diagnosis and therapy of AD by modulating Aβ aggregation. The materials mainly include organic photothermal agents or photosensitizers, polymer materials, metal nanoparticles, quantum dots, carbon-based nanomaterials, etc. In addition, compared to traditional fluorescent dyes, aggregation-induced emission (AIE) molecules have the advantages of good stability, low background signals, and strong resistance to photobleaching for bioimaging. Some AIE-based materials exhibit excellent photothermal and photodynamic effects, showing broad application prospects in the diagnosis and therapy of AD. We further summarize the advances in the detection of Aβ aggregates and phototherapy of AD using AIE-based materials. Full article
(This article belongs to the Special Issue Biosensors Based on Self-Assembly and Boronate Affinity Interaction)
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20 pages, 1106 KB  
Article
Synchrotron-Based Structural Analysis of Nanosized Gd2(Ti1−xZrx)2O7 for Radioactive Waste Management
by Marco Pinna, Andrea Trapletti, Claudio Minelli, Armando di Biase, Federico Bianconi, Michele Clemente, Alessandro Minguzzi, Carlo Castellano and Marco Scavini
Nanomaterials 2025, 15(14), 1134; https://doi.org/10.3390/nano15141134 - 21 Jul 2025
Viewed by 414
Abstract
Complex oxides with the general formula Gd2(Ti1−xZrx)2O7 are promising candidates for radioactive waste immobilization due to their capacity to withstand radiation by dissipating part of the free energy driving defect creation and phase transitions. [...] Read more.
Complex oxides with the general formula Gd2(Ti1−xZrx)2O7 are promising candidates for radioactive waste immobilization due to their capacity to withstand radiation by dissipating part of the free energy driving defect creation and phase transitions. In this study, samples with varying zirconium content (xZr = 0.00, 0.15, 0.25, 0.375, 0.56, 0.75, 0.85, 1.00) were synthesized via the sol–gel method and thermally treated at 500 °C to obtain nanosized powders mimicking the defective structure of irradiated materials. Synchrotron-based techniques were employed to investigate their structural properties: High-Resolution X-ray Powder Diffraction (HR-XRPD) was used to assess long-range structure, while Pair Distribution Function (PDF) analysis and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy provided insights into the local structure. HR-XRPD data revealed that samples with low Zr content (xZr ≤ 0.25) are amorphous. Increasing Zr concentration led to the emergence of a crystalline phase identified as defective fluorite (xZr = 0.375, 0.56). Samples with the highest Zr content (xZr ≥ 0.75) were fully crystalline and exhibited only the fluorite phase. The experimental G(r) functions of the fully crystalline samples in the low r range are suitably fitted by the Weberite structure, mapping the relaxations induced by structural disorder in defective fluorite. These structural insights informed the subsequent EXAFS analysis at the Zr-K and Gd-L3 edges, confirming the splitting of the cation–cation distances associated with different metal species. Moreover, EXAFS provided a local structural description of the amorphous phases, identifying a consistent Gd-O distance across all compositions. Full article
(This article belongs to the Section Physical Chemistry at Nanoscale)
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