Search Results (2,900)

The construction of the Archaeological Site Prediction Model (ASPM) and quantitative research on the driving mechanisms of influencing factors are key to better understanding the multidimensional interactions between ancient humans and the environment. They also constitute an essential technical approach for guiding field archaeological survey and excavation. This study aims to develop a highly stable, accurate, and interpretable predictive model for archaeological sites in the Chongqing Three Gorges region (CQTGR). BP neural network prediction (BPNN) has been applied in various fields, but its random initial weights and thresholds often lead to suboptimal accuracy and weak interpretability. To address these issues, this study constructs BPNN optimized with a Bayesian algorithm to enhance its accuracy. Additionally, it integrates the SHAP model to quantitatively identify nonlinear interactions and threshold effects of influencing factors, thereby improving its interpretability. The results indicate that: (1) The BPNN-based prediction model outperforms other conventional models. After hyperparameter optimization using the Bayesian algorithm, the AUC (area under the ROC curve) on the test set increases by 0.0812, reaching a final value of 0.8815. This indicates that the optimization model is effective and that the model exhibits strong predictive capability. (2) Archaeological sites exhibit a tiered and linear corridor distribution pattern along the Yangtze River and its major tributaries. This pattern can be divided into five concentric tiers radiating outward from the core of the main river systems. High-probability zones are particularly clustered in the low-lying and flat river valleys. (3) The distribution of archaeological sites is comprehensively influenced by both the natural environment and human activities. Elevation and river systems are key driving factors, with NDVI and land use also exerting significant influence. The major factors demonstrate notable threshold and interaction effects. Areas where the interaction between factors exhibits positive enhancement are often the core areas of archaeological site distribution. This research not only provides a precise scientific basis for the preventive protection and monitoring of potential distribution areas of archaeological sites but also offers decision support for the spatial conservation planning of these sites. Full article

Uranium is a naturally occurring radioactive heavy metal, and drinking water and food are the primary sources of non-occupational exposure for the general population. The aim of the present study was to evaluate urinary uranium concentrations among cancer patients and healthy residents living in uranium legacy-affected areas and to compare them with those of individuals residing in a region with a more favorable radiological environment, accounting for urinary creatinine levels. An observational human biomonitoring study was conducted among 80 adults divided into four groups (n = 20 each): cancer patients and healthy residents from the exposed area and cancer patients and healthy residents from the comparison area. Twenty-four-hour urine samples were analyzed for uranium using inductively coupled plasma mass spectrometry, and urinary creatinine was measured using the kinetic Jaffe method. Urinary uranium concentrations ranged from 0.01 to 1.30 µg/L, with the highest values observed in cancer patients from the exposed area. After creatinine adjustment, median uranium concentrations were 0.0974 µg/g creatinine in exposed cancer patients, 0.0888 µg/g creatinine in exposed healthy residents, 0.0515 µg/g creatinine in comparison-area cancer patients, and 0.0607 µg/g creatinine in comparison-area healthy residents. Significant differences were observed between exposed and comparison populations among both cancer patients (p = 0.0066) and healthy residents (p = 0.0499). Residence in the exposed area was positively associated with urinary uranium levels (ρ = 0.292, p = 0.012). These findings suggest higher internal uranium exposure among residents of uranium legacy-affected areas and support the use of urinary uranium as a biomarker of environmental exposure. This study contributes to the assessment of internal uranium exposure in residents of uranium legacy-affected areas, including both cancer patients and healthy residents. However, the findings should be interpreted as differences in exposure biomarkers and do not establish a causal relationship between uranium exposure and cancer. Full article

Colombia ranks third among South American countries in terms of fungal diversity (including lichens); however, the lichen diversity of tropical dry forest ecosystems, particularly those in the Caribbean region, remains relatively understudied. The typical lichens found in tropical dry forest are crustose/corticolous microlichens (adapted to the xerophytic environments), which produce certain secondary metabolites that act as protective agents against ultraviolet radiation/decomposition/depredators; nonetheless, secondary metabolites of most of these lichens have not yet been described. This study focused on the compositional analysis and the extrolite content of seven lichens: Cryptothecia sp., Cryptothecia scripta, Graphis dendrogramma, Leucodecton occultum, Helminthocarpon leprevostii, Pyrenula ochraceoflava, and Allographa seminuda, using thin-layer chromatography, high-performance liquid chromatography–diode array detector, liquid chromatography–electrospray–mass spectrometry and/or liquid chromatography–tandem mass spectrometry. The main findings were: (i) two Cryptothecia spp. contained 2′-O-methylperlatolic acid (97%) or ovoic/gyrophoric acids (67%/28%); (ii) two specimens of G. dendrogramma had stictic/norstictic acids (33–60%/40%); (iii) three samples of L. occultum were characterized by norstictic acid (42–82%); (iv) schizopeltic/3-O-methylschizopeltic acids (58%/32%) were found in one specimen of H. leprevostii; (v) one sample of P. ochraceoflava was represented by unidentified xanthone-type metabolite/7-chloroemodin/ (26%/24%); and, (vi) the extrolite content in one specimen of A. seminuda was negligible. Finally, 10 of the 11 lichen specimens studied from the Department of Atlántico within Colombia contained certain secondary metabolites that likely reflect the common types of extrolites, namely, di-/tri-depsides, depsidones, dibenzofurans, and chlorinated anthraquinones/xanthones, which could be hypothetically related to the evolutionary patterns of this type of organism. Full article

This study investigates shading technologies used to protect vertical green façades (VGF) from excessive solar exposure and climate-related stresses. A scoping review of 176 publications from the past decade was conducted, focusing on innovative materials and components applied in adaptive and passive shading systems relevant to Central and Southern European climates (BSh, Csa, Csb, Cfa, Cfb, Dfb). Only technologies that reached at least the prototype or small-scale trial stage were included. The review identifies several categories of emerging adaptive solutions—such as smart materials, pneumatic systems, PCM-integrated, PV-integrated, algae-based, hygromorphic, electro-optic, fluidic, and mechanical or mechatronic devices—which show potential to improve microclimatic regulation and user comfort, though their long-term durability and integration with VGFs remain insufficiently documented. Advances in digital fabrication and optimisation support the development of high-performance passive elements, while experimental and simulation studies indicate that dynamic shading can offer promising outcomes across diverse climatic contexts. To strengthen the plant-centred perspective, each shading category is evaluated through four criteria: PAR transmission, microclimatic regulation, evapotranspiration behaviour, and integration constraints. Climate projections suggest that radiation and heat stress may increasingly challenge certain VGF species in warmer regions, highlighting the need for shading strategies aligned with plant requirements, local conditions, user needs, and long-term maintenance. Full article

Nuclear infrastructure requires reliable gamma radiation shielding, for which heavyweight concrete offers a practical, structural solution. Conventional concrete provides poor gamma shielding and heat durability, demanding a denser alternative. Prior studies show that magnetite enhances attenuation and strength, while dolomite improves thermal/mechanical stability, yet findings are dispersed across materials and test conditions. Hybrid magnetite–dolomite concrete requires systematic evaluation for simultaneous optimal gamma shielding and mechanical performance under nuclear conditions. Two mixes were produced by partial replacement of coarse aggregate (Mix 1: 50% magnetite, 25% dolomite; Mix 2: 25% magnetite, 50% dolomite), casted and cured per standard practice with compressive strength measured at 7 and 28 days. Gamma attenuation was quantified using Cs-137 and Co-60. Mix 1 achieved 78.78% attenuation for Cs-137 and 76.86% for Co-60, while Mix 2 reached 77.65% and 74.68%, respectively. At 28 days, peak compressive strengths were 25.8 MPa (magnetite), 22.6 MPa (dolomite), and 20.6 MPa (control), with pre-peak energy capacity ranking as follows: magnetite > dolomite > control. Magnetite increased strength and attenuation but sharpened post-peak softening, whereas dolomite enhanced deformability and energy dissipation with minimal loss in shielding. Hybrid concrete satisfied shielding and strength targets and outperformed conventional concrete, with a magnetite-forward blend offering the best overall protection. Full article

Radiation-induced bystander effect (RIBE) contributes to oxidative and nitrosative stress in non-irradiated tissues following ionizing radiation (IR). This study investigated the protective effects of propolis and caffeic acid phenethyl ester (CAPE) against RIBE-mediated renal injury after total cranial irradiation in rats. Forty-eight male Sprague–Dawley rats were assigned to six groups: IR, IR + propolis, IR + CAPE, propolis control, CAPE control, and sham. A single 5 Gy cranial gamma irradiation was administered. Propolis (80 mg/kg/day, orally) and CAPE (10 μmol/kg/day, intraperitoneally) were given for 10 days. Renal antioxidant (SOD, GSH-Px, GST), oxidative (XO, MDA), and nitrosative (NOS, NO) parameters were evaluated. Multivariate analyses, including principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA), were performed. IR significantly decreased SOD activity and increased XO, MDA, NOS, and NO levels. Both propolis and CAPE effectively reversed these alterations, with propolis showing a more pronounced effect on oxidative stress markers. GSH-Px and GST activities remained unchanged. The findings suggest that propolis and CAPE attenuated oxidative/nitrosative changes in kidney tissue, consistent with a possible bystander-associated systemic response. Full article

Background: This study aimed to assess cone-beam computed tomography (CBCT) knowledge, adherence to justification criteria, field-of-view (FOV) selection practices, and awareness of radiation protection guidelines among dental practitioners in the Asir region. In Saudi Arabia, the Saudi Food and Drug Authority (SFDA) and the Nuclear and Radiological Regulatory Commission are the regulatory bodies responsible for radiation protection and the safe use of dental imaging; limited awareness of their roles may undermine regulatory compliance and patient safety. Accordingly, the specific objectives of this study were: (i) to assess knowledge of CBCT justification criteria and radiation-dose magnitudes; (ii) to evaluate adherence to the requirement for a prior 2D radiograph; (iii) to examine FOV selection across standardized clinical vignettes; (iv) to explore factors associated with knowledge scores; and (v) to identify perceived barriers to appropriate CBCT prescribing. Methods: A cross-sectional descriptive-analytical survey targeted 73 dental practitioners in Abha, Saudi Arabia. A validated 30-item questionnaire was distributed via Google Forms using snowball convenience sampling. The effective target population comprised dental practitioners and interns working in Abha during the study period. Because recruitment used open snowball distribution without a fixed sampling frame, a formal response rate could not be calculated. Results: The mean knowledge score was 5.47/10 (standard deviation: 1.86). Item-level correct rates were 82.2% for caries detection, 80.8% for the requirement for a prior 2D radiograph, and 58.9% for paediatric CBCT justification. FOV selection across four clinical vignettes ranged from 27.4% to 68.5% correct, with the lower-left-molar implant vignette showing the lowest rate (27.4%) and the six-unit anterior implant bridge vignette also poorly answered (37.0%), reflecting a frequent tendency to select an inappropriately large FOV. Guideline awareness was low: 65.8% were completely unaware of the Safety and Efficacy of a New and Emerging Dental X-ray Modality Computed Tomography (SEDENTEX CT) 2012 guidelines, while 54.8% did not know that the American Dental Association publishes specific radiation guidelines. In an exploratory multivariable model, no factor was a statistically significant predictor of the knowledge score; formal CBCT training showed a small, non-significant association (B = 0.585; 95% confidence interval [−0.27, 1.44]; p = 0.175). Conclusions: In this preliminary survey, CBCT knowledge among dental practitioners in Abha was moderate but suboptimal, with almost half of respondents scoring below the satisfactory threshold and with significant gaps in FOV optimisation and guideline awareness. Given the small, non-probability sample, these findings should be regarded as preliminary and hypothesis-generating. Full article

In this study, daily reference evapotranspiration (ET₀) values for the period 2025–2030 for Lake Burdur, located in the Mediterranean climate zone and within the Burdur closed basin, were estimated using nested architecture focused on high accuracy. The ET₀ target corresponds to the FAO-56 Penman–Monteith reference evapotranspiration variable provided by the Open-Meteo Historical Weather API, and it is treated throughout as a standardized measure of atmospheric evaporative demand rather than as actual lake-surface evaporation or basin water loss. For this purpose, daily mean air temperature, relative humidity, shortwave surface radiation, and evapotranspiration data for the period 1984–2024 were obtained from the Open-Meteo platform. In the first stage of the study (Model 1), separate SARIMAX (statistical), XGBoost (machine learning), and LSTM (deep learning) models were applied for temperature, relative humidity, and radiation series; the model with the highest validation mean for each variable was selected. Accordingly, LSTM (Mean $R^2$ = 0.967) was determined to be the most successful model for temperature, SARIMA(X) (Mean $R^2$ = 0.812) for relative humidity, and XGBoost (Mean $R^2$ = 0.845) for the radiation variable, which is non-linear, has strong autocorrelation, and exhibits distinct seasonality. In the second stage (Model 2), these best climate predictions were used as independent variables for evapotranspiration, and LSTM provided the highest success for evapotranspiration (Mean $R^2$ = 0.941). Trend analyses revealed that the increase in temperature and evapotranspiration and the decrease in relative humidity observed in the past period will continue in the near future. The uncertainty analysis conducted using the Monte Carlo/resampling approach on historical data showed that the 95% prediction intervals largely protected the upward trend in evapotranspiration against random fluctuations. These intervals reflect residual-based uncertainty under the fitted model rather than the full predictive uncertainty of future basin evapotranspiration. The findings indicate that designing model selection appropriate to the structure of the variables within a nested prediction framework significantly improves forecast accuracy and can provide a viable decision support input for sustainable water management in Mediterranean basins experiencing water scarcity. Full article

This study describes a comparative assessment of the structural properties, mechanical properties and gamma-ray shielding effectiveness of monzogranite to determine whether or not they can be used for sustainable shielding construction materials. The results of the petrographic, X-ray fluorescence (XRF), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS) analyses reveal that the monzogranite is composed essentially of quartz, K-feldspar, plagioclase and biotite. The SiO₂ contents of all the monzogranite studied also indicated that they are highly crystalline (70.77% to 73.34% SiO₂ by weight) and chemically stable (therefore, monzogranite); other properties such as density (2.70 to 3.06 g/cm³), porosity (19 to 23%) and water absorption (12 to 15%) demonstrated the structural compactness and durability of the samples studied. Additionally, the mechanical properties of all of the samples were extremely high, and included: (a) the unconfined compressive strength ranged from 89.28 to 240.20 MPa; (b) the engineering modulus ranged from 40.6 to 66.5 GPa; (c) the Brazilian tensile strength ranged from 7.4 to 15.2 MPa; and (d) the flexural strength ranged from 9.3 to 16.4 MPa. The shielding effectiveness against gamma rays was rated over a wide range of photon energies (0.015–15 MeV) via Phy-X/PSD and experimentally using NaI (Tl) spectroscopy at specific gamma photon energies 0.662 MeV, 1.173 MeV and 1.332 MeV. The experimental measurements of gamma-ray attenuation were validated with Phy-X/PSD calculations, with the average variation being 5.8% and no single variation over 10%, and therefore, reliability has been successfully demonstrated. The linear attenuation coefficients (LACs) were measured from 24.674 cm⁻¹ at 0.015 MeV to 0.065 cm⁻¹ at 15 MeV, which illustrates the dependence of gamma-ray interactions’ mechanisms on the energy of the incoming radiation. The half value layer (HVL) went from 0.028 cm to 10.621 cm and the mean free path (MFP) increased from 0.041 cm to 15.323 cm. The best measured performance properties were attributed to specimen MB3, as it had the highest radiation protective efficiency (88.58% at 0.15 MeV) and the lowest radiation transmission (72.16% at 0.09 MeV) in comparison to all of the experimental conditions considered. The high attenuation properties of MB3 were attributed to its high density and high levels of iron oxide, Fe₂O₃. The present work demonstrates that monzogranite, specifically sample MB3, provides excellent mechanical strength, as well as effective shielding from gamma radiation. Therefore, monzogranite, and particularly MB3, is a creative alternative for sustainable construction, as it provides materials that will be used for radiation shielding in nuclear, medical and industrial applications. Full article

Two major factors influence the expected recovery of the ozone layer: a decline in ozone-depleting substances (ODSs) due to implementation of the Montreal Protocol and stratospheric cooling due to increasing greenhouse gas (GHG) concentration. We investigate the largest spring Arctic ozone anomalies revealed in three ensemble calculations of the chemistry–climate model (CCM) SOCOLv3 under moderate (SSP2-4.5) and severe (SSP5-8.5) scenarios of GHG growth, accounting for the expected decline in ODS concentrations over 2015–2099. During the first half of the 21st century, the coldest winters could still produce Arctic total ozone content (TOC) anomalies comparable with the record spring 2020 values, despite the overall recovery of the ozone layer by mid-century. In March and April, TOC may occasionally drop below 220 Dobson Units. According to estimates from the Moscow State University (MSU) radiation model, the lowest TOC values under cloudless midday conditions could increase surface UV radiation by a factor of 1.5–2, reaching a UV index of 5–6 (and up to ~8 in April)—levels requiring sun protection measures. Full article

To address insufficient representativeness and the potential risk of the underestimation of the long-term atmospheric diffusion assessment of nuclear facility gaseous effluents, a CFD numerical simulation framework based on annual joint-frequency weighting of 16 wind directions, 6 wind speed classes and 6 atmospheric stability classes is proposed and applied to a representative multi-source nuclear facility. The regulation law of near-surface flow field of the building complex and the diffusion characteristics of uranium aerosol is analyzed. The results indicate: Complex building matrix facilitates the formation of recirculating wake regions, which may serve as potential zones for aerosol accumulation. The uranium aerosol concentration weighted by joint frequency presents a distribution characteristic of central agglomeration and asymmetric gradient attenuation. Compared with the single most-frequent meteorological scenario, the joint-frequency-weighted field shows a higher expected peak and a 237 m shift in peak position. This shows that the joint-frequency weighting framework can reduce directional bias and underestimation of hotspot extent relative to a most-frequent meteorological condition. The method may provide quantitative support for refined radiation protection management and the environmental monitoring layout of nuclear facilities. Full article

Chronic ultraviolet B (UVB) radiation drives cutaneous photoaging—clinically manifesting as erythema, edema, scaling, deep wrinkling, loss of elasticity, and barrier disruption—through mitochondrial reactive oxygen species (mtROS) overproduction and quality-control failure. Here we identify α-ketoglutarate (AKG; also known as 2-oxoglutarate), a TCA-cycle intermediate and essential co-substrate for α-ketoglutarate-dependent dioxygenases (α-KGDDs), as a metabolic corrector of mitochondrial redox homeostasis in UVB-induced photoaging. In a 10-week chronic UVB SKH1 hairless mouse model, microneedle-assisted transdermal delivery of AKG dose-dependently attenuated macroscopic erythema, scaling, and erosive lesions, restored skin barrier function and dermal elasticity, preserved epidermal–dermal architecture, and protected collagen and elastic fiber integrity, with efficacy comparable to all-trans retinoic acid. Mechanistically, AKG reactivated α-KGDD/prolyl hydroxylase (PHD) catalytic function and promoted proteasomal clearance of aberrantly stabilized HIF-1α under normoxia; this was accompanied by restored AMPK Thr172 phosphorylation downstream of constitutive LKB1 and recovery of PGC-1α-driven mitochondrial biogenesis. AKG preferentially attenuated mitochondrial superoxide over total cellular ROS through a co-substrate-mediated mechanism distinct from direct radical scavenging, and its protective effects were largely abrogated by DMOG (an α-KGDD inhibitor) or compound C (an AMPK inhibitor). These findings position AKG, delivered via microneedle-assisted topical application, as a candidate metabolite-based intervention targeting the α-KGDD/HIF-1α/AMPK axis for photoaging. Full article

To systematically examine the effects of ambient wind speed on the fire behavior of inclined tunnel cables, this paper determines the combustion characteristics of ZR-RVV cable combustion parameters using synchronous thermal analysis and cone calorimetry. A 1:20 scaled tunnel platform was established based on Froude similarity criterion to conduct combustion experiments under varying wind speeds (0–0.7 m/s) and inclination angles (−30°–30°). Results indicate the ignition time of the cable decreases gradually with increasing external heating radiation intensity (25–50 kW/m²), with ignition at 295.1 °C. A modified Richardson number (Ri*) is introduced to quantitatively identify the dominant flow regime. It is confirmed that when |θ| ≈ 20°, Ri* ≈ 1, and the fire behavior transitions from “domination” (Ri* < 0.5) to “buoyancy-driven stack effect domination” (Ri* > 2). This critical inclination angle provides decisive guidance for fire source localization, smoke control, and exhaust design. Increasing ambient wind speed significantly reduces the fire temperature and dilutes the smoke; at a wind speed of 0.7 m/s, the maximum temperature drop at the ceiling monitoring point reaches 67%, while CO/CO₂ concentrations decrease correspondingly. The findings provide a theoretical basis for smoke exhaust design and fire monitoring in tunnel fire protection. Full article

Skin functionalities are instrumental in four main domains: protection, regulation, sensation, and support. However, excessive exposure to ultraviolet (UV) radiation can compromise skin integrity and, in turn, affect its functions, by generating reactive oxygen species (ROS). Aiming to protect skin from UV radiation, sunscreens incorporate UV filters and antioxidants that absorb/reflect UV rays and neutralise free radicals, respectively. Nevertheless, undesired side and ecological effects of conventional UV filters have spurred the search for safer alternatives. Among synthetic antioxidants, thioethers have attracted attention for their redox power and potential medicinal properties. In this context, a library of aminopyrimidine–arylthioether conjugates was synthesised and evaluated for their antioxidant, enzyme-inhibitory and antibacterial activities, as well as for their cytotoxicity in HaCaT cells and potential photoprotective properties. Among the aminopyrimidine-thioethers studied, compound C5 stood out for its antioxidant potential, exhibiting a value of 566.39 mM FeSO₄ equivalents per mM of the compound, while compound C2 showed the highest anti-enzymatic potential, inhibiting elastase (45.58%) and tyrosinase activities (34.66%). Regarding photoprotective activity, compound C13 reduced by 33.74% the ROS production induced by UV radiation exposure, at 100 μM, a non-cytotoxic concentration. Finally, compound C7 inhibited the growth of Staphylococcus epidermidis, Staphylococcus hominis and Cutibacterium acnes, at 30 μM. These preliminary results demonstrate that aminopyrimidine–arylthioethers constitute a new class of compounds warranting further investigation for skin protection. Compound C5 showed antioxidant activity in the FRAP assay, comparable to that of the positive control, BHT. Full article

To address the issue of radioactive waste generated by the large-scale promotion and use of nuclear energy, safety evaluations of disposal sites in various surrounding rocks are essential. These evaluations are a prerequisite for ensuring the long-term safe disposal of radioactive waste. This study focuses on the blocking capacity of clay rocks concerning the advection–dispersion behavior of representative radionuclides such as ¹³⁷Cs, ⁷⁹Se, and ⁹⁹Tc. It further examines the effects of competitive adsorption that arise when these three radionuclides coexist. (Since ⁷⁹Se is difficult to obtain, ⁷⁵Se was used as a substitute nuclide. In the mixed-nuclide experiments, the stable isotope Re was used to replace ⁹⁹Tc.) The experimental findings revealed that competitive adsorption can significantly reduce the adsorption capability of clay rocks for ¹³⁷Cs and ⁷⁹Se, altering the adsorption mechanism. During the advection–dispersion process, the weak adsorption sites of ¹³⁷Cs and ⁷⁹Se on clay rocks become active after the strong adsorption sites are preferentially occupied, resulting in a decline in both adsorption quantity and rate. In the case of ⁹⁹Tc, competitive adsorption weakens the effect of anion repulsion, leading to a reduction in the immobile liquid regions (θ_im). Full article