Search Results (105)

Background/Objectives: The marginal adaptation of CAD/CAM restorations remains a key determinant of long-term clinical success, particularly in minimally invasive preparations. This in vitro study evaluated and compared the marginal gap of three CAD/CAM restorative materials—Cerasmart, G-CAM, and IPS Empress CAD—using standardized preparation and SEM measurement protocols. Methods: A total of 18 crowns were fabricated, of which 9 presented margins sufficiently interpretable under SEM and were included in the pooled quantitative analysis (n = 362 measurement points). Marginal gaps were recorded at 45×, 100× and 450× magnification using a Jeol JSM 25S scanning electron microscope. Normality and variance homogeneity were verified prior to parametric testing. Results: When pooled per material group, the mean ± SD marginal gap values were 18.53 ± 14.15 µm for Cerasmart, 21.60 ± 14.89 µm for G-CAM, and 47.09 ± 16.93 µm for IPS Empress CAD. All values fell below the contemporary clinical threshold of <70 µm for adhesive cementation. Pairwise comparison showed a large difference between IPS Empress CAD and the two resin-based materials, whereas the difference between Cerasmart and G-CAM was small. Conclusions: Hybrid and resin nano-ceramic CAD/CAM materials demonstrated narrower marginal gaps compared with the glass ceramic tested, likely due to their lower elastic modulus and greater seating accommodation during cementation. Within the limits of this in vitro design, all materials exhibited marginal adaptation consistent with current clinical acceptability criteria. Full article

Early-age cracking remains a major durability challenge for concrete. It is primarily caused by internal restraint stresses induced by humidity and temperature gradients during hydration. Conventional approaches often fail to capture the coupled and non-uniform nature of heat and moisture transport, limiting their ability to predict cracking risk and evaluate mitigation strategies. To address this limitation, we characterize the spatiotemporal evolution of internal humidity and temperature using a spatial coefficient of variation. From a numerical standpoint, the influence of polypropylene fibers (PPFs) on internal relative humidity is elucidated by adopting an unconditionally stable backward-Euler finite-difference scheme to resolve multiple coupled physicochemical processes—hydration, heat release, self-desiccation, heat and moisture diffusion to the environment—and their mutual interactions. Furthermore, a one-dimensional homogeneous random-field model is proposed to quantify the spatial non-uniformity of humidity in PPF concrete. On this basis, the effects of polypropylene fibers (PPFs) in mitigating internal humidity is quantitatively revealed. Good agreement is achieved between simulations and tests, with standard deviations of 0.0119 for normal concrete and 0.0041 for PPF concrete, thereby validating the model’s predictive capability for the spatiotemporal distribution of internal relative humidity (RH) in PPF concrete. According to the numerical analysis, owing to the moisture-sorption characteristics of PPFs, at a depth of 25 mm, the internal RH in PPF concrete has decreased by 16% at 28 days, whereas normal concrete exhibits a 28% decrease. With increasing depth, the RH reduction at 28 days is approximately 13% for both PPF concrete and plain concrete, and the time-dependent evolution of RH in PPF concrete is broadly similar to that of normal concrete. Furthermore, the mitigating influence of PPFs decreases with hydration age and distance from the surface, reflecting the gradual decline of diffusion heterogeneity over time and depth. These findings provide new numerical evidence for the effectiveness of PPFs in reducing the early-age cracking risk in concrete. Full article

Fractal dimension (Frac) and lacunarity (Lac) are frequently proposed as biomarkers of multiscale image complexity, but their incremental value over standardized radiomics remains uncertain. We position both measures within the Image Biomarker Standardisation Initiative (IBSI) feature space by running a fully reproducible comparison in two settings. In a baseline experiment, we analyze $N=1000$ simulated $64\times 64$ textured ROIs discretized to $N_g=64$, computing 92 IBSI descriptors together with Frac (box counting) and Lac (gliding box), for 94 features per ROI. In a wavelet-augmented experiment, we analyze $N=1000$ ROIs and add level-1 wavelet descriptors by recomputing first-order and GLCM features in each sub-band (LL, LH, HL, and HH), contributing $4\times (19+19)=152$ additional features and yielding 246 features per ROI. Feature similarity is summarized by a consensus score that averages z-scored absolute Pearson and Spearman correlations, distance correlation, maximal information coefficient, and cosine similarity, and is visualized with clustered heatmaps, dendrograms, sparse networks, PCA loadings, and UMAP and t-SNE embeddings. Across both settings a stable two-block organization emerges. Frac co-locates with contrast, difference, and short-run statistics that capture high-frequency variation; when wavelets are included, detail-band terms from LH, HL, and HH join this group. Lac co-locates with measures of large, coherent structure—GLSZM zone size, GLRLM long-run, and high-gray-level emphases—and with GLCM homogeneity and correlation; LL (approximation) wavelet features align with this block. Pairwise associations are modest in the baseline but become very strong with wavelets (for example, Frac versus GLCM difference entropy, which summarizes the randomness of gray-level differences, with $\left|r\right|\approx 0.98$; and Lac versus GLCM inverse difference normalized (IDN), a homogeneity measure that weights small intensity differences more heavily, with $\left|r\right|\approx 0.96$). The multimetric consensus and geometric embeddings consistently place Frac and Lac in overlapping yet separable neighborhoods, indicating related but non-duplicative information. Practically, Frac and Lac are most useful when multiscale heterogeneity is central and they add a measurable signal beyond strong IBSI baselines (with or without wavelets); otherwise, closely related variance can be absorbed by standard texture families. Full article

Cloud detection is an indispensable step in satellite remote sensing of cloud properties and objects under the influence of cloud occlusion. Nevertheless, interfering targets such as snow and haze pollution are easily misjudged as clouds for most of the current algorithms. Hence, a robust cloud detection algorithm is urgently needed, especially for regions with high latitudes or severe air pollution. This paper demonstrated that the passive satellite detector Advanced Geosynchronous Radiation Imager (AGRI) onboard the FY-4A satellite has a great possibility to misjudge the dense aerosols in haze pollution as clouds during the daytime, and constructed an algorithm based on the spectral information of the AGRI’s 14 bands with a concise and high-speed calculation. This study adjusted the previously proposed cloud mask rectification algorithm of Moderate-Resolution Imaging Spectroradiometer (MODIS), rectified the MODIS cloud detection result, and used it as the accurate cloud mask data. The algorithm was constructed based on adjusted Fisher discrimination analysis (AFDA) and spectral spatial variability (SSV) methods over four different underlying surfaces (land, desert, snow, and water) and two seasons (summer and winter). This algorithm divides the identification into two steps to screen the confident cloud clusters and broken clouds, which are not easy to recognize, respectively. In the first step, channels with obvious differences in cloudy and cloud-free areas were selected, and AFDA was utilized to build a weighted sum formula across the normalized spectral data of the selected bands. This step transforms the traditional dynamic-threshold test on multiple bands into a simple test of the calculated summation value. In the second step, SSV was used to capture the broken clouds by calculating the standard deviation (STD) of spectra in every 3 × 3-pixel window to quantify the spectral homogeneity within a small scale. To assess the algorithm’s spatial and temporal generalizability, two evaluations were conducted: one examining four key regions and another assessing three different moments on a certain day in East China. The results showed that the algorithm has an excellent accuracy across four different underlying surfaces, insusceptible to the main interferences such as haze and snow, and shows a strong detection capability for broken clouds. This algorithm enables widespread application to different regions and times of day, with a low calculation complexity, indicating that a new method satisfying the requirements of fast and robust cloud detection can be achieved. Full article

Many intrinsically disordered proteins (IDPs) are known to undergo liquid–liquid phase separation (LLPS), which is a physical process that drives the formation of biomolecular condensates and membraneless organelles in biological cells. Molecular dynamics (MD) simulations provide valuable tools to explore both the molecular mechanisms of LLPS and the physical properties of biomolecular condensates. However, a direct comparison of MD simulation results with phase diagrams obtained experimentally is normally prevented not only by the high computational costs of simulating large biomacromolecular systems on sufficient timescales but also by conceptual challenges. Specifically, there currently seems to be no standard or unambiguous method of defining and determining volumes occupied by coexisting phases at the nanoscale, with typically no more than a few hundred biomacromolecules in the simulation box. The goal of this work is to fill in this gap in the methodology. Focusing on $\alpha$-synuclein as a model IDP, we test and compare three methods for determining the molecular density of protein nanodroplets, or clusters, generated in MD simulations or using other molecular modeling approaches. Two of the methods are based on approximating nanodroplets with homogeneous spheres and ellipsoids, respectively. The third method, which is expected to yield the most physically accurate results, is based on the SPACEBALL algorithm, with optimized, cluster-specific radii for volume probes. Our results contribute to the construction of accurate phase diagrams on the basis of MD simulations of IDP systems. Full article

Background/Objectives: Accurate full-arch impressions are crucial for predictable prosthodontic outcomes. While intraoral scanners (IOSs) are increasingly adopted, evidence comparing their accuracy with conventional analog impressions across full mandibular arches—particularly under both laboratory and clinical conditions using an objective intraoral reference—is limited. Our study aims to evaluate the in vitro and in vivo accuracy of digital impressions compared to conventional methods in full-arch scans using an intraoral reference tool. Methods: In this study, a custom stainless steel transfer aid carrying four 5 mm steel spheres in a trapezoidal configuration, provided with known reference distances, was used. Ten mandibular Frasaco models (in vitro) and ten healthy young adults (18–30 yrs) with intact lower arches (in vivo) received the bonded spheres. Six inter-sphere distances were defined: intermolar (BL-BR), interpremolar (FL-FR), diagonals (BL-FR, FL-BR), and lateral spans (BL-FL, BR-FR). Each arch underwent a digital scan (Medit i700) and a conventional monophase PVS impression, which was poured in Type IV stone and digitized (GOM Scan 1). The inter-sphere linear distances were measured in GOM Inspect, and trueness (deviation from reference) and precision (SD) were calculated. Data normality and homogeneity were verified; parametric t-tests and one-sample tests (α = 0.05) assessed differences between workflows and against reference values. Results: In vitro, analog impressions closely matched reference distances, with only the long-span BL-BR showing minor deviation (0.053 mm, p < 0.001). Digital scans showed significantly greater deviations across all spans (max 0.117 mm), particularly over long distances. In vivo, both workflows demonstrated comparable accuracy: only BL-BR (analog) and BR-FR (digital) differed significantly from the reference, and all AMEs remained within clinical thresholds (≤0.10 mm), except for BL-BR and BL-FL spans. ICC values ranged from moderate to high. Direct paired comparisons revealed statistically equivalent performance across most spans. Conclusions: Analog impressions outperformed digital scans in vitro, particularly across longer spans, confirming their superior dimensional fidelity under controlled conditions. However, in vivo, both workflows delivered statistically comparable and clinically acceptable accuracy. These findings suggest that while analog impressions remain the gold standard for precision-demanding contexts, modern intraoral scanners—when used correctly—can offer reliable full-arch mandibular impressions. The four-sphere reference system proved valuable for objective, anatomy-independent measurement. Full article

Purpose: The aim of this in vitro study was to evaluate the influence of different models of commercially available portable dental radiometers on the measurement of light irradiance emitted by light-emitting diode (LED) photocuring units. Materials and Methods: Eight LED photocuring units, all emitting light in a single-wavelength spectrum, were tested. Light irradiance (mW/cm²) was measured using six portable dental radiometers: four digital models (D1–D4) and two analog models (A1, A2). Digital model D1 was used as the reference (control). All measurements were conducted under standardized conditions, and each LED–radiometer combination was tested in triplicate. Data were analyzed using Sigma Plot 12.0 (Palo Alto, CA, USA) to verify the assumptions of normality and homogeneity of variances. A one-way analysis of variance (ANOVA) was used to assess the effect of the radiometer model on irradiance values, followed by Tukey’s post hoc test for multiple comparisons. The significance level was set at α < 0.05. Results: No statistically significant difference in irradiance was found between D1 (control) and D2. However, significantly lower values were recorded with A2, while D3, D4, and A1 produced significantly higher irradiance values compared to the control (p < 0.05). Conclusion: Irradiance measurements can vary significantly depending on the radiometer model used. Clinicians should be aware of this variability and are encouraged to regularly check the irradiance of the light-curing units used in daily practice, ensure their proper maintenance, and implement periodic monitoring to maintain effective clinical performance. Full article

Matrix certified reference materials (mCRMs) are materials characterized by suitable homogeneity, stability, and traceability, with certified values, including uncertainties, and a specific matrix. mCRMs constitute a reference for instrumental analytical methods and ensure their metrological consistency. Matrix certified reference materials (mCRMs) are essential tools for ensuring the accuracy and traceability of analytical measurements, particularly for samples with complex matrices. These mCRMs are carefully manufactured materials that closely mimic the composition and properties of real samples, allowing laboratories to validate their analytical methods, calibrate analytical instruments, or check the classical methods. This article highlights the challenges associated with the production and characterization of these complex mCRMs, including obtaining homogeneous materials, establishing accurate target values, and ensuring stability for different types of materials, such as gases, liquids, and metal alloys. Additionally, the process of statistical evaluation through the use of advanced statistical methods is discussed, as is the systems approach associated with the implementation of the ISO 17034 standard, which specifies the requirements for manufacturers of reference materials. This paper also includes a summary of the current status in trends of normalization as well as mCRM production. Full article

Background/Objectives: Over the past three decades, emergency medicine in Romania has evolved from a developing specialty into a cornerstone of the national healthcare system. As we reflect on these 30 years, it becomes evident that the lessons learned and the systems developed form a vital foundation for the future. This study aims to explore how the accumulated experience can guide us toward building a more resilient emergency medical system, one that prioritizes quality, ensures patient and provider safety, and embraces modern principles of healthcare management. The objectives of this study were to explore the long-term perspectives of physicians and nurses working in emergency departments (EDs), to determine the triggering factors that may lead to abandoning the specialty, and to identify of malpractice risks arising from doctor–patient interaction. Methods: This study employed an observational design and utilized an opinion questionnaire to assess the participants’ perspectives. Qualitative data were presented as frequencies and percentages. Quantitative data were expressed as means and standard deviations after verifying normal distribution with the Shapiro–Wilk test. Comparisons between groups for qualitative variables were conducted using the chi-square test. For comparisons of quantitative variables between two groups, Student’s t-test was employed following confirmation of homogeneity of variances with Levene’s test. A p-value of < 0.05 was considered statistically significant. Results: Out of 1228 estimated responders, 641 completed the questionnaire. A total of 577 of participants met the inclusion criteria: 256 (44.4%) nurses and 321 (55.6%) doctors, with an average age of the responders of 40.06 years. Nurses reported the highest level of managerial support (83.2%, p < 0.001). EPs had the highest rate of non-participation in working groups for procedures/protocols/guidelines (49.5%, p < 0.001). Intensive care unit medical doctors (ICU-MDs) and EPs were the main groups reporting a deficiency in employer-provided resources to manage conflict situations (63.7%, 61.7%; p <0.001). EPs (28%) reported practicing defensive medicine (inadequate educational support, the absence of clear protocols). Workplace burnout was reported by the ICU-MDs and EPs responders (96.3%; 93.4%; p < 0.001), and 26% of EPs expressed interest in professional reorientation. Conclusions: This study highlights four strategic directions for rebuilding a resilient healthcare system focused on improving quality of care and safety: development of procedures/protocols, managerial reorganization, restoration of healthcare professionals’ trust through new strategies, and academic development. Full article

The zygomatic bone area experiences frequent mechanical damage in the middle craniofacial region, including the orbital floor. The orbital floor bone is very thin, ranging from 0.74 mm to 1.5 mm. Enhancing digitization, reconstruction, and CAD modeling procedures is essential to improving the visualization of this structure. Achieving a homogeneous surface with high manufacturing accuracy is crucial for developing precise surgical models and tools for creating titanium mesh implants to reconstruct the orbital floor geometry. This article improved the accuracy of reconstruction and CAD modeling using the example of the development of a prototype implant to replace the zygomatic bone and a tool to form the geometry of the titanium mesh within the geometry of the orbital floor. The masked stereolithography (mSLA) method was used in the model manufacturing process because it is low-cost and highly accurate. Two manufacturing modes (standard and ultra-light) were tested on an Anycubic Photon M3 Premium 3D printer to determine which mode produced a more accurate representation of the geometry. To verify the geometric accuracy of the manufactured models, a GOM Scan1 structured light scanner was used. In the process of evaluating the accuracy of the model preparation, the maximum deviation, mean deviation, range and standard deviation were determined. The maximum deviations for anatomical structures created using the normal mode ranged from ±0.6 mm to ±0.7 mm. In contrast, models produced with the ultra-light mode showed deviations of ±0.5 mm to ±0.6 mm. Furthermore, the results indicate that the ultra-light mode offers better surface accuracy for die and stamp models. More than 70% of the surface of the models is within the deviation range of ±0.3 mm, which is sufficient for planning surgical procedures. However, the guidelines developed in the presented publication need to optimize the CAD process and select 3D-printing parameters to minimize deviations, especially at the edges of manufactured models. Full article

The vulva is a complex anatomical organ that may present with a wide range of pathologies. Even if it can be easily investigated, correctly interpreting vulvar appearance is often challenging. Vulvar ultrasound is an emerging diagnostic technique that may be helpful in different aspects of vulvar pathology. We aimed to summarize the state of the art of vulvar ultrasound, provide the necessary theoretical bases of embryology and anatomy, describe the normal and pathological vulvar sonographic characteristics, and propose a feasible and reproducible methodology for vulvar ultrasound. Vulvar sonographic scan should be performed with a linear probe, preferably > 15 mHz, following a standardized methodology. The sonographic appearance of the normal vulva reflects the different histology of its structures and, thus, their embryogenetic origin. The description of a suspected vulvar lesion should include localization, dimensions, volume, type of growth, shape, appearance of the edges, depth of invasion, echogenicity, and identification of vascularization. Cystic dilatation of obstructed Bartolini ducts is the most common benign finding in the vulva (fluctuant structures in the posterior third of the labia majora containing clear mucous fluid). Malignant vulvar lesions appear as hypoechogenic or heterogeneous solid lesions with irregular margins and a high degree of vascularization. Extramammary Paget Disease presents a homogeneous hypoechogenic creeping area in the epidermis due to neoplastic cells typical of this disease. The potential applications of vulvar ultrasound are examining the content of a vulvar swelling to guide its management and assessing the response to medical treatment in the case of lichen sclerosus. In managing patients affected by vulvar malignancies, it may play a critical role in local staging, stromal invasion determination, measuring the distance from the midline, and assessing the eligibility for sentinel lymph node procedure. Vulvar ultrasound is a minimally invasive and economical test that can be performed with minimal equipment. Further studies will be necessary to validate the clinical applications, quantify the diagnostic performance, and evaluate the agreement between operators. Full article

Climate change and increasing water demand are causing supply problems in Mexico City and the State of Mexico. The lack of complete and up-to-date meteorological information makes it difficult to understand and analyze climate phenomena such as droughts. Climate Engine provides decades of climate data to analyze such changes. These data were used to calculate SPEI (Standardized Precipitation-Evapotranspiration index) at scales of 1, 3, 6, 9, 12, and 24 months between 1981 and 2023 in the study area. The Standard Normal Homogeneity Test (SNHT) indicated greater homogeneity in temperature data, while precipitation data exhibited potential inhomogeneities. The Mann–Kendall test showed no significant trend for precipitation but a clear increasing trend in temperature. Droughts have become more frequent and severe over the last decade, particularly in the western State of Mexico and the southwest of Mexico City. The wettest years within the last 14 years were 2010, 2015, and 2018, while the most severe droughts occurred in 2017, 2019, 2020, 2021, and 2023. The findings suggest intensifying drought conditions, likely driven by rising temperatures and climate variability. These trends emphasize the need for improved water resource management and adaptation strategies to mitigate the growing impact of droughts in central Mexico. Full article

The upper oesophagogastrointestinal (UEGI) tract histology, intestinal morphometry and lymphocyte subpopulations of healthy people is scarcely known. In research studies of inflammation involving the UEGI tract, there is a lack of adequate healthy controls. Aims: To evaluate the histology of the UEGI tract and the duodenal lymphocyte subpopulations of healthy volunteers and patients with gastroesophageal reflux disease (GERD), the latter to assess if it could replace healthy subjects. Healthy individuals were excluded if they had symptoms, comorbidities, pregnancy, toxics, medications or abnormal blood analysis. Subjects in both groups with abnormal duodenal intraepithelial lymphocyte (IEL) counts were also excluded. A total of 280 subjects were assessed, and 37 were included (23 healthy and 14 with GERD). The GERD group showed a higher IEL count (median [IQR]: 19.5 [17–22]), than healthy group: (15 [12–18]), p = 0.004. Eosinophils, mast cells and intestinal morphometry were similar in both groups. In the lamina propria, CD4+ T cells decreased (p = 0.008), and CD8+ T cells increased (p = 0.014). The total innate lymphoid cells (ILC) and CD3− cells decreased (p = 0.007) in GERD group compared to healthy controls. At the intraepithelial level, NKT cells increased (p = 0.036) and ILC3 decreased (p = 0.049) in the GERD group. This is the first study to comprehensively map the histology, morphometry and duodenal subpopulations of healthy volunteers to help define a “gold standard” of normality. The differences found between both groups suggest that, whenever possible, healthy subjects should be included in research studies. Alternatively, we can consider a well-defined homogenous group with GERD to serve as the control group. Full article

Rapid and accurate detection of protein content is essential for ensuring the quality of maize. Near-infrared spectroscopy (NIR) technology faces limitations due to surface effects and sample homogeneity issues when measuring the protein content of whole maize grains. Focusing on maize grain powder can significantly improve the quality of data and the accuracy of model predictions. This study aims to explore a rapid detection method for protein content in maize grain powder based on near-infrared spectroscopy. A method for determining protein content in maize grain powder was established using near-infrared (NIR) reflectance spectra in the 940–1660 nm range. Various preprocessing techniques, including Savitzky−Golay (S−G), multiplicative scatter correction (MSC), standard normal variate (SNV), and the first derivative (1D), were employed to preprocess the raw spectral data. Near-infrared spectral data from different varieties of maize grain powder were collected, and quantitative analysis of protein content was conducted using Partial Least Squares Regression (PLSR), Support Vector Machine (SVM), and Extreme Learning Machine (ELM) models. Feature wavelengths were selected to enhance model accuracy further using the Successive Projections Algorithm (SPA) and Uninformative Variable Elimination (UVE). Experimental results indicated that the PLSR model, preprocessed with 1D + MSC, yielded the best performance, achieving a root mean square error of prediction (RMSEP) of 0.3 g/kg, a correlation coefficient (R_p) of 0.93, and a residual predictive deviation (RPD) of 3. The associated methods and theoretical foundation provide a scientific basis for the quality control and processing of maize. Full article

The aim of this work is to investigate drought variability in Padua, northern Italy, over a nearly 300-year period, from 1725 to 2023. Two well-established and widely used indices are calculated, the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI). They are compatible with a data series starting in the early instrumental period, as both can be estimated using only temperature and precipitation data. The Padua daily precipitation and temperature series from the early 18th century, which were recovered and homogenized with current observations, are used as datasets. The standard approach to estimate SPI and SPEI based on gamma and log-logistic probability distribution functions, respectively, is questioned, assessing the fitting performance of different distributions applied to monthly precipitation data. The best-performing distributions are identified for each index and accumulation period at annual and monthly scales, and their normality is evaluated. In general, they detect more extreme drought events than the standard functions. Moreover, the main statistical values of SPI are very similar, regardless of the approach type, as opposed to SPEI. The difference between SPI and SPEI time series calculated with the best-fit approach has increased since the mid-20th century, in particular in spring and summer, and can be related to ongoing global warming, which SPEI takes into account. The innovative trend analysis applied to SPEI12 indicates a general increasing trend in droughts, while for SPI12, it is significant only for severe events. Summer and fall are the most affected seasons. The critical drought intensity–duration–frequency curves provide an easily understandable relationship between the intensity, duration and frequency of the most severe droughts and allow for the calculation of return periods for the critical events of a certain duration. Moreover, the longest and most severe droughts over the 1725–2023 period are identified. Full article