Search Results (214)

Objectives: Due to extra-axial forces, post and core (PC) treatment has the worst survival probability in abutment teeth for telescopic crown-retained dentures (TCDs). The reason for this is a mismatch regarding the mechanical properties between PC material and dentin or a poor accuracy of fit of PC, resulting in tooth fracture or decementation. However, the inclusion of severely damaged endodontically treated teeth needing PC is often mandatory in order to achieve a stable situation for TCD. Thus, an advancement of PC treatment for TCD is of high clinical interest. Recently it has become possible to fabricate customized PC with favourable mechanical properties by using CAD/CAM technology. Methods: Thus, the aim of this investigation was to compare the performance of these PC types (CAD/CAM PC) to customized cast PC (CPC) and prefabricated fibre-reinforced PC (PFPC) in a TCD set-up using a chewing simulator. Results: The investigation group with CAD/CAM PC showed neither tooth fracture nor decementation, in contrast to the CPC and PFPC groups, in which both types of failure were recorded. Thus, CAD/CAM PC showed significantly better performance than CPC and PFPC. Conclusions: Within the limitations, CAD/CAM PCs are therefore recommendable for PC treatment with TCD. Full article

The Numidian cypress (Cupressus sempervirens var. numidica, C. numidica hereafter) is a rare, almost unknown, endemic taxon of Tunisia whose conservation has long been hampered by human activities, taxonomic uncertainty and limited ecological knowledge, with only 64.33 ha of its populations remaining. Although recent genetic studies have confirmed its native status and long-term isolation, detailed information on its distribution, population structure and threats remain lacking. This study provides the first comprehensive assessment of C. numidica across its remaining range. Field surveys revealed that the species persists in only three small, fragmented forests, Bou Abdallah, Sidi Amer, and Dir Satour, covering a total of 64.33 ha. Soil analysis revealed some differences among sites, with Bou Abdallah showing higher clay content and Dir Satou exhibiting the highest levels of nitrogen, organic carbon, Olsen P, and available Mn and Mo. Climatic analyses indicate a semi-arid Mediterranean environment with pronounced summer droughts and a clear warming trend. Trees showed widespread damages, due to intensive grazing, tree cutting, crown dieback (drought), and pest and pathogen attacks. Natural regeneration was limited, and the condition of affected trees ranged from moderate to severe, with Bou Abdallah showing the highest levels of degradation. Notably, the severe fungal pathogen Seiridium cardinale, causal agent of cypress canker, was detected on C. numidica for the first time, highlighting an urgent conservation concern. Our results point to a staged conservation approach over time. In the immediate term (within 1 year), urgent monitoring and management of S. cardinale is needed. In the short term, efforts should focus on protecting carefully selected areas, about 5–10 regeneration microsites per forest, from grazing to support natural regeneration, reduce ongoing soil degradation, and establish clonal and seed-production plantations along with long-term seed storage. In the long term, the survival of C. numidica will only be possible with the active involvement of local communities, through awareness campaigns, adapting traditional practices such as gdel, and developing small-scale ecotourism that provides sustainable livelihoods while reinforcing support for conservation. Full article

The Draa Sfar polymetallic mine, located near Marrakech in Morocco, represents the deepest currently operating underground mine in North Africa, with workings extending beyond depths of −1200 m. At such depths, mining activities are conducted within weak, highly anisotropic foliated black pelites, where recurrent instability mechanisms, most notably rib buckling and crown deterioration, are frequently observed, especially in drifts developed parallel to the foliation planes. In this context, the present study integrates detailed structural field observations with two-dimensional finite-element modelling using RS2 in order to analyse excavation-scale stability within these schistose pelitic rocks. Both numerical simulations and field evidence indicate that increasing depth-related confinement, together with a dominant in situ stress regime, favours stress channelling and localized damage development, while the pronounced transverse weakness of the pelites exerts a primary control on failure kinematics, including schistosity-parallel spalling, asymmetric rib buckling, and shear along inclined foliation intersecting the excavation back. Instability processes are further intensified by excavation geometry and mine layout: angular, square-shaped profiles and foliation-parallel drift orientations generate steeper stress gradients and greater convergence compared to arched sections, while proximity to stopes and adjacent openings enhances mining-induced stress redistribution and associated deformation. Intersection areas emerge as the most critical configurations, where the superposition of stress perturbations and structurally controlled damage mechanisms accelerates wall convergence and roof sagging. Overall, these findings demonstrate that drift stability cannot be adequately evaluated using generic design criteria when excavation geometry, interaction effects, and structural anisotropy exert a dominant influence on mechanical behaviour. Consequently, a fully integrated approach that combines drift geometry optimisation, detailed structural mapping, site-calibrated numerical modelling, and in situ monitoring is required to achieve reliable stability assessment and control. Full article

The fatigue behaviour of a 90° long radius elbow, which is adjacent to the feedwater nozzle in a BWR, was analyzed. The start-up and shutdown transients were considered. A thermo-mechanical finite element analysis was carried out to determine the stresses induced by thermal transients, considering the environmental conditions in the reactor feedwater pipe. In addition, the Palmgren–Miner methodology and the ASME B&PVC code fatigue curve were applied to evaluate the accumulated damage and service life of the component. Environmental correction factors were considered to estimate environmentally assisted fatigue. Reductions in fatigue life were observed. In the second part of this paper, a part-through thickness semielliptical crack was also postulated in the internal surface of the elbow. It was aligned along the axial direction at the crown zone. Its growth was modelled using the Paris equation, evaluating the risk of failure using fracture parameters. It was found that the vulnerable area is located on the inner surface of the elbow, due to the concentration of stress caused by the curved geometry. Failure assessment diagrams (FADs) were plotted. It was found that the crack depth is the main factor governing crack behaviour under the conditions studied. The results provide a methodology for assessing the integrity of pipes subjected to specific environmental and operating conditions. Full article

Voids behind the lining that develop during long-term operation can seriously compromise the seismic safety performance of metro shield tunnels. To investigate the influence of such void defects on large-diameter shield tunnels, this study systematically analyzed the causes and distribution patterns of voids. A three-dimensional discontinuous finite element model was developed to simulate the interaction among lining segments, connecting bolts, and surrounding rock. The seismic responses, including circumferential stress, interface slip, interface opening, and bolt tensile stress, were analyzed considering coupled factors such as the void circumferential angle, radial depth, distribution location, and geological conditions. Single-factor and multi-factor sensitivity analyses were conducted to evaluate the significance of the above coupled factors on the overall seismic response. The results show that lining circumferential stress, displacement, interface opening, and bolt stress increase with void enlargement, a shift in void location from the crown to the haunch, and deterioration of geological conditions. A void located at the right haunch leads to a peak circumferential stress of 3.27 MPa, causing local segment damage. Sensitivity analysis reveals that void location is the most influential factor affecting the seismic response, while geological conditions exhibit lower sensitivity. A predictive model for the peak circumferential stress around the void was established using multiple linear regression, incorporating void position, circumferential angle, and radial depth. Within the parameter range considered in this study, this model provides a theoretical basis and practical reference for rapid seismic risk assessment and safety management of shield tunnels with void defects. Full article

Wheat Fusarium crown rot (FCR), predominantly caused by Fusarium species, is a devastating fungal disease that severely threatens global wheat production. In this study, we combined phytopathological assays, molecular techniques, and bioinformatic analyses to systematically identify the causal agents of FCR in Xinjiang and to screen for potential biocontrol bacteria. A total of 296 fungal isolates were obtained from 195 FCR samples, collected from Yumin County and Xinhe County. Morphological and phylogenetic analyses revealed that Fusarium culmorum was the predominant pathogen, accounting for 73.6% of the total isolates. To evaluate the resistance of local wheat cultivars, F. culmorum XN22-1, a highly virulent strain from Xinhe County, was inoculated to 30 wheat varieties. The results demonstrated that most cultivars lacked resistance to FCR, with the exception of three varieties—Xinchun 19, Xinchun 50, and Youpi 23, which showed a mid-resistance. Given the scarcity of resistant cultivars, we focused on biological control. To control FCR, Pseudomonas aeruginosa J-7, exhibiting broad-spectrum antagonistic activity, was successfully isolated from rhizosphere soil based on the analysis of healthy rhizosphere soil microbial diversity. Subsequently, pot experiments showed that P. aeruginosa J-7 could significantly reduce the disease incidence and lower the disease index of wheat FCR. Furthermore, whole-genome sequencing, in-plate metabolite analysis, and observation on inhibition of spores and mycelium revealed that P. aeruginosa J-7 mediates its biocontrol activity primarily through the production of phenazine and siderophores, which collectively inhibit conidial germination and cause structural damage to the mycelium. This study not only clarifies the composition of FCR pathogens in Xinjiang but also provides a promising biocontrol agent and new strategic insights for the management of wheat crown rot. Full article

Zirconia is a material that mimics human teeth and has been extensively studied and applied. This study investigated the surface modifications of dental zirconia induced by two UV-C wavelengths (222 and 254 nm). A total of 72 zirconia specimens were prepared and divided into groups for irradiation at varying distances (1, 6, 12 cm) and durations (40, 120, 480 and 1440 min), with three specimens retained as untreated controls. Surface changes were assessed by measuring colour difference (ΔE) and water contact angle, and by analyzing surface morphology and elemental composition using SEM and EDX, and XRD was employed to determine the crystalline structure. The results showed that both wavelengths induced clinically perceptible colour changes (ΔE > 2.0), with the most pronounced effect at 6 cm for 222 nm and 1 cm for 254 nm. WCA decreased significantly with irradiation time, showing a linear correlation with log(time), and 222 nm irradiation yielded lower WCA than 254 nm. While SEM revealed no morphological changes, both UV treatments significantly increased the Zr/O ratio compared to the control. XRD tests confirmed that UV-C irradiation does not damage the zirconium oxide crystal structure. It is concluded that both UV-C wavelengths can alter the colour and enhance the wettability of zirconia; these modifications are particularly relevant for dental restorative applications, specifically in the fabrication of anterior tooth crowns, where achieving a natural tooth-like appearance is desired. Full article

Storm damage poses an increasing risk to radiata pine (Pinus radiata D. Don) plantations in New Zealand as extreme wind events intensify under climate change. This study quantified wind damage following ex-tropical Cyclone Gabrielle in a seven-year-old genetics trial comprising 12 genotypes grown under four stand configurations defined by contrasting stocking (833 and 1282 stems/ha) and cultivation (with and without cultivation) treatments. The genotypes comprised a Pinus attenuata × P. radiata var. cedrosensis hybrid, ten anonymised radiata pine clones and an industry-standard radiata pine seedlot. Field assessments and unmanned aerial vehicle UAV laser scanning were used to classify damage into stem breakage and overturning and to derive structural metrics, including tree diameter, height, slenderness, volume, crown width and crown volume. Overall, 16.7% of trees were damaged, with stem breakage (10.2%) occurring more frequently than overturning (6.5%). Averaged across the four treatments, total damage significantly ranged from 10.4% in the high stocking cultivated treatment to 23.5% in the low stocking no cultivation treatment. Variation between the 12 genotypes was highly significant, with breakage, overturning and total damage ranging from 3.3%–25.4%, 1.4%–15.0% and 6.6%–29.5%, respectively, between the 12 genotypes. Two radiata pine clones with high growth rates and low to moderate wind damage had the highest post-storm total stem volume per hectare, which greatly exceeded that of the hybrid or the widely planted radiata pine seedlot. These findings highlight the potential of clones that combine high growth rates and resistance to wind damage to maintain high productivity under a changing climate with a greater frequency of extreme weather events. Full article

Objectives: This study aimed to determine whether surface wear, identified through the superimposition of intraoral scans (IOS), can predict subsurface damage progression detected by optical coherence tomography (OCT) during fatigue testing of computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns. Methods: Monolithic CAD/CAM composite crowns (Brilliant Crios; $n=8$) were adhesively luted to standardized prepared human teeth and artificially aged by cyclic loading in a mouth-motion simulator (50–500 N, 2 Hz, 37 °C). Under phantom-head condition, IOS (surface wear) and handheld swept-source (SS)-OCT (subsurface damage) were performed before loading and after every 250,000 cycles. OCT crack depth/width were normalized to local thickness and cusp-tip distance; correspondence between IOS- and OCT-derived metrics at each timepoint was assessed with Spearman’s rank correlation coefficient ($\rho$) to test whether surface wear can predict subsurface damage under the given conditions. Results: All specimens survived without catastrophic failure, and both modalities revealed progressive damage from the earliest observation interval. OCT consistently showed higher defect percentages and larger dispersion (e.g., mean vertical defects (25.47 ± 4.97)% OCT vs. (4.36 ± 0.91)% IOS at T1 and (66.79 ± 19.53)% OCT vs. (7.78 ± 3.19)% IOS at T5). Across all timepoints, no statistically significant associations between IOS and OCT were observed (p = 0.146 to 0.955). Conclusions: Within the limitations of this exploratory, single-material in vitro study, restricted to a CAD/CAM composite (Brilliant Crios), surface-based monitoring alone did not reliably reflect subsurface damage progression. Clinically, this suggests that surface wear assessment may underestimate subsurface fatigue damage. Intraoral OCT may provide complementary, non-invasive information alongside routine IOS for individualized monitoring, but its added value needs to be confirmed in larger studies and other CAD/CAM composite materials and additional restorative material classes. Full article

Reconstructing original cusp dimensions in worn molars represents a fundamental challenge across dentistry, anthropology, and paleontology, as dental wear obscures critical morphological information. In this proof-of-concept study, we present a standardized machine learning pipeline for predicting original cusp height, specifically the horn tips of the enamel–dentine junction (EDJ), in worn lower molars using three-dimensional morphometric data from micro-computed tomography (micro-CT). We analyzed 40 permanent lower first (M1) and second (M2) molars from four hominin groups, systematically evaluated across three wear stages: original, moderately worn (worn1), and severely worn (worn2). Morphometric variables including height, area, and volume were quantified for each cusp, with Random Forest and multiple linear regression models developed individually and combined through ensemble methods. To mimic realistic reconstruction scenarios while preserving a known ground truth, models were trained on unworn specimens (original EDJ morphology) and tested on other teeth after digitally simulated wear (worn1 and worn2). Predictive performance was evaluated using root mean square error (RMSE) and coefficient of determination (R²). Our results demonstrate that under moderate wear (worn1), the ensemble models achieved normalized RMSE values between 11% and 17%. Absolute errors typically below 0.25 mm for most cusps, with R² values up to ~0.69. Performance deteriorated under severe wear (worn2), particularly for morphologically variable cusps such as the hypoconid and entoconid, but generally remained within sub-millimetric error ranges for several structures. Random Forests and linear models showed complementary strengths, and the ensemble generally offered the most stable performance across cusps and wear states. To enhance transparency and accessibility, we provide a comprehensive, user-friendly software pipeline including pre-trained models, automated prediction scripts, standardized data templates, and detailed documentation. This implementation allows researchers without advanced machine learning expertise to explore EDJ-based reconstruction from standard morphometric measurements in new datasets, while explicitly acknowledging the limitations imposed by our modest and taxonomically unbalanced sample. More broadly, the framework represents an initial step toward predicting complete crown morphology, including enamel thickness, in worn or damaged teeth. As such, it offers a validated methodological foundation for future developments in cusp and crown reconstruction in both clinical and evolutionary dental research. Full article

Diplodia shoot blight is an opportunistic fungal pathogen infesting many conifer species and it has a global distribution. Depending on the duration and severity of the disease, affected needles appear yellow (chlorotic) for a brief period before becoming red or brown in colour. These symptoms can occur on individual branches or over the entire crown. Aerial sketch-mapping or the manual interpretation of aerial photography for tree health surveys are labour-intensive and subjective. Recently, however, the application of deep learning (DL) techniques to detect and classify tree crowns in high-spatial-resolution imagery has gained significant attention. This study evaluated two complementary DL approaches for the detection and classification of Pinus radiata trees infected with diplodia shoot blight across five geographically dispersed sites with varying topographies over two acquisition years: (1) object detection using YOLOv12 combined with Segment Anything Model (SAM) and (2) pixel-level semantic segmentation using U-Net, SegFormer, and EVitNet. The three damage classes for the object detection approach were ‘yellow’, ‘red-brown’ (both whole-crown discolouration) and ‘dead tops’ (partially discoloured crowns), while for the semantic segmentation the three classes were yellow, red-brown, and background. The YOLOv12m model achieved an overall mAP50 score of 0.766 and mAP50–95 of 0.447 across all three classes, with red-brown crowns demonstrating the highest detection accuracy (mAP50: 0.918, F1 score: 0.851). For semantic segmentation models, SegFormer showed the strongest performance (IoU of 0.662 for red-brown and 0.542 for yellow) but at the cost of longest training time, while EVitNet offered the most cost-effective solution achieving comparable accuracy to SegFormer but with a superior training efficiency with its lighter architecture. The accurate identification and symptom classification of crown damage symptoms support the calibration and validation of satellite-based monitoring systems and assist in the prioritisation of ground-based diagnosis or management interventions. Full article

Forests provide a wide range of ecosystem services, and their importance in supporting human well-being is widely recognized. As goods and benefits from forests are exhaustible, it is therefore essential to gather sound data for their monitoring and management. Remote sensing has gained increasing importance in collecting data on forests, driven by the growing demand for regularly updated environmental data. However, remote sensing modeling of vegetation requires reference data to be collected in the field. This article presents a dataset on tree crown cover—both total and by species—of 528 georeferenced forest plots located in the Eastern Alps, Italy, an area affected by extensive wind and snow damage and subsequent widespread damage caused by bark beetles. The characteristic species of the forest types in the dataset are widely distributed over the Eurasian continent, making the dataset potentially useful to many users and researchers studying forest biodiversity or remote sensing applications to monitor forest cover changes. Data were collected within a still ongoing project aimed at detecting crown cover changes in small forest patches. Full article

Calonectria ilicicola (anamorph: Cylindrocladium parasiticum) is a globally important soil-borne fungal pathogen, causing Cylindrocladium black rot (CBR) in peanuts (Arachis hypogaea) and red crown rot (RCR) in soybeans (Glycine max), two legume crops central to global food security. Under favorable conditions, these diseases can cause yield losses of 15–50%, with severe epidemics causing substantial economic damage. A defining feature of C. ilicicola is its production of melanized microsclerotia that persist in soil for up to seven years, complicating long-term disease management across major production regions worldwide. The recent spread of RCR into the U.S. Midwest highlights the adaptive potential of the pathogen and underscores the urgency of updated, integrated control strategies. This review synthesizes current knowledge on disease symptoms, pathogen biology, the life cycle, isolation techniques, and molecular diagnostics, with particular emphasis on recent genomic and multiomics advances. These approaches have identified key virulence-associated genes and core pathogenicity factors, providing new insights into host–pathogen interactions and enabling more targeted resistance breeding through marker-assisted selection and the use of wild germplasm. We critically evaluate integrated disease management strategies, including host resistance, chemical and biological control, cultural practices, and physical interventions, highlighting their complementarities and limitations. By integrating classical pathology with emerging molecular and ecological innovations, this review provides a comprehensive background for developing more effective and sustainable management approaches for CBR and RCR. Full article

The influence of crown illumination on leaf damage of horse chestnut species (Aesculus hippocastanum L., Aesculus glabra Willd, Aesculus flava Aiton, Aesculus pavia L., Aesculus × carnea Hayne, Aesculus parviflora Walter, Aesculus chinensis Bunge) affected by ohrid leaf miner (Cameraria ohridella Deschka & Dymić) was studied using some accessions from the arboretum botanical tree collection. A. hippocastanum, A. glabra, A. flava had the lowest chl a content in the foliage on the sunlit side of the crown, while in A. pavia, A. parviflora and A. chinensis this indicator was the highest. The chl a content in the leaves of A. hippocastanum and A. flava under shaded conditions was 1.3 and 2.4 times higher than in the sunlit part, while in A. pavia, A. parviflora and A. chinensis the chl a content on the shaded side was 1.2, 1.6 and 1.3 times lower. The quantitative content of chl b in the sunlit part of the crown in A. hippocastanum and A. flava was significantly higher than in the other species. Moreover, while A. flava and A. parviflora had the highest chl b content in the foliage of the shaded part of the crown, A. glabra and A. × carnea had the lowest. Similarly, differences in proline levels were found in the leaves of different horse chestnut species on the sunny side of the crown. Higher proline levels in less infested species were identified. Water content imbalances due to feeding by leaf miners were most characteristic of the severely affected species. Chlorophyll fluorescence determination revealed high photochemical activity with an effective defense system in resistant species, while non-resistant species exhibited weak defense mechanisms in both sunlight and shade. To assess horse chestnut species the hyperspectral analysis indices (DSWI and SIPI) were also successfully applied. Changes in chl a and chl b content, proline levels, and leaf water-holding properties can be used to assess the resistance of horse chestnut species using classical physiological and biochemical methods. Hyperspectral analysis indices (DSWI and SIPI) can also be successfully applied. Full article

Chemical and thermal shifts in the oral cavity can damage the surface of 3D-printed hybrid resin–ceramic materials, and research on these effects is still limited. This study investigated the effects of pH and temperature variations on the surface roughness (Ra) of two milled materials, a resin nanoceramic (Cerasmart^®; CS) and a polymer-infiltrated ceramic network (Vita Enamic^®; EN), and a 3D-printed (VarseoSmile Crown plus^®; VS) material. A total of 135 rectangular specimens (12 × 14 × 2 mm), 45 per material, were aged for 30 days under acidic (pH 5), alkaline (pH 9), cold (5 °C), and hot (60 °C) conditions, with neutral (pH 7, 37 °C) as a control. Ra was measured before and after aging using an optical micro-coordinate system. Two-way ANOVA and Tukey’s test assessed the effects of material type and aging condition. Paired t-tests evaluated changes over time. Variations in pH did not significantly increase Ra for any materials. Cold and hot temperatures increased Ra for the milled materials (p < 0.001). VS showed greater stability than the milled materials (CS and EN) despite its higher Ra both before and after aging under all conditions. All Ra values remained below the clinical threshold for biofilm accumulation (0.2 µm) under all conditions. Full article