Search Results (26)

Objective: This study aimed to assess the diagnostic value of contrast-enhanced ultrasound (CEUS) time–intensity curve (TIC) parameters in detecting non-ossified thyroid cartilage invasion in patients with laryngeal squamous cell carcinoma (SCC). Methods: A CEUS TIC analysis was performed on 32 cases from 27 patients with histologically confirmed laryngeal SCC. The diagnostic performance of time to peak (TTP), peak intensity (PI), wash-in slope (WIS), area under the curve (AUC), and their quantitative differences (∆TTP, ∆PI, ∆WIS, and ∆AUC) to discriminate between the invaded and the non-invaded non-ossified thyroid cartilage was determined using ROC analysis. A logistic regression analysis was employed to identify significant predictors. Results: In an ROC analysis, of all TIC parameters analyzed separately, ∆TTP showed the greatest diagnostic performance (AUC: 0.85). A ∆TTP cut-off of ≤ 8.9 s differentiated between the invaded and the non-invaded non-ossified thyroid cartilage with a sensitivity of 100%, specificity of 76.9%, and accuracy of 81.3%. A combination of ∆TTP and PI increased the AUC to 0.93, specificity to 100%, and accuracy to 96.8%, but reduced the sensitivity to 83.3%. Meanwhile, the visual assessment of enhancement on CEUS to detect cartilage invasion had 83.3% sensitivity and 84.6% specificity. In a univariate logistic regression, only ∆TTP was a significant predictor of non-ossified thyroid cartilage invasion (OR: 0.80; 95% CI: 0.64–1.00). For every second increase in ∆TTP, the probability of thyroid cartilage invasion decreased by 20%. Conclusions: CEUS TIC parameters, particularly a combination of ∆TTP and PI, showed high diagnostic performance in the detection of non-ossified thyroid cartilage invasion in laryngeal SCC. Full article

The Paleozoic strata in the Kongxi slope zone of the Dagang oilfield, Huanghua depression, exhibit significant hydrocarbon exploration potential. Although bitumen is widely present in the Paleozoic reservoirs, its formation process and genetic mechanism remain poorly understood. This study systematically investigates the occurrence, maturity, origin, and evolutionary processes of Paleozoic reservoir bitumen in the Kongxi zone through core observations, microscopic analyses, geochemical testing, and thermal simulation experiments. The results reveal that reservoir bitumen in the Kongxi slope zone is characteristically black with medium to medium-high maturity. In core samples, bitumen occurs as bands, veins, lines, and dispersions within partially filled fractures and breccia pores. Petrographic analysis shows bitumen partially occupying intergranular pores and intergranular pores of Lower Paleozoic carbonate rocks and Upper Paleozoic sandstones, either as complete or partial pore fills. Additional bitumen occurrences include strip-like deposits along microfractures and as bitumen inclusions. Dark brown bitumen fractions were also identified in crude oil separates. The formation and evolution of Paleozoic reservoir bitumen in the Kongxi slope zone occurred in two main stages. The first-stage bitumen originated from Ordovician marine hydrocarbon source rocks, subsequently undergoing oxidative water washing and biodegradation during tectonic uplift stage. This bitumen retains compositional affinity with crude oils from Lower Paleozoic carbonate rocks. Second-stage bitumen formed through the thermal evolution of Carboniferous crude oil during deeper burial, showing compositional similarities with Carboniferous source rocks and their oil. This two-stage bitumen evolution indicates charging events in the Paleozoic reservoirs. While early uplift and exposure destroyed some paleo-reservoirs, unexposed areas within the Dagang oilfield may still contain preserved primary accumulations. Furthermore, second-stage hydrocarbon, dominated condensates derived from Carboniferous coal-bearing sequences since the Eocene, experienced limited thermal evolution to form some bitumen. These condensate accumulations remain the primary exploration target in the Paleozoic Formations. Full article

The advent of geomatic techniques and novel sensors has opened the road to new approaches in mapping, including morphological ones. The evolution of a land portion and its graphical representation constitutes a fundamental aspect for scientific and land planning purposes. In this context, new paradigms for geomorphological mapping, which are useful for modernizing traditional, geomorphological mapping, become necessary for the creation of scalable digital representation of processes and landforms. A fully remote mapping approach, based on multi-source and multi-sensor applications, was implemented for the recognition of landforms and processes. This methodology was applied to a study site located in central Italy, characterized by the presence of ‘calanchi’ (i.e., badlands). Considering primarily the increasing availability of regional LiDAR products, an automated landform classification, i.e., Geomorphons, was adopted to map landforms at the slope scale. Simultaneously, by collecting and digitizing a time-series of historical orthoimages, a multi-temporal analysis was performed. Finally, surveying the area with an unmanned aerial vehicle, exploiting the high-resolution digital terrain model and orthoimage, a local-scale geomorphological map was produced. The proposed approach has proven to be well capable of identifying the variety of processes acting on the pilot area, identifying various genetic types of geomorphic processes with a nested hierarchy, where runoff-associated landforms coexist with gravitational ones. Large ancient mass movement characterizes the upper part of the basin, forming deep-seated gravity deformation, highly remodeled by a set of widespread runoff features forming rills, gullies, and secondary shallow landslides. The extended badlands areas imposed on Plio-Pleistocene clays are typically affected by sheet wash and rill and gully erosion causing high potential of sediment loss and the occurrence of earth- and mudflows, often interfering and affecting agricultural areas and anthropic elements. This approach guarantees a multi-scale and multi-temporal cartographic model for a full-coverage representation of landforms, representing a useful tool for land planning purposes. Full article

Mountain ecosystems are among the most difficult areas for plant cultivation due to water erosion occurring on the slopes. Growing plants in these areas may lead to a weakening of ecosystem functions and in degradation of these areas and threatens sustainability. In this experiment, the anti-erosion effectiveness of maize, oat and spring vetch were assessed through the measuring of LAI and sheet wash from a slope where cultivation had occurred. Averaged values from the six years field experiment (2017–2022) reveal that maize achieved maximum soil protection between the 115th and 128th day of vegetation (14 days), when the LAI value equals to 3.8–4.0. The corresponding values for oats were 63–81 days of vegetation (19 days; LAI 2.4–2.7). The longest period of maximum soil protection was achieved from the cultivation of spring vetch compared to maize and oats (between the 49th and 82nd day of its vegetation, i.e., 34 days), when the LAI value was in the range of 2.2–3.0. Soil cover at their maximum development is conservative compared to mountain ecosystems, and in the case of the studied plants, the protection time varied. These relationships were quantified by simple regression equations. Additionally, taking into account the compiled climate data, the average air temperature in the years of research (2017–2022) was higher than the multi-year average (1961–2000) by 2.15 °C, which may confirm the fact that the climate is warming in the region of Southern Poland. Full article

Accurate data mapping and visualization are of crucial importance for the detection and monitoring of slope morphodynamics, including erosion processes and studying small erosional landforms (rills and gullies). The purpose of the current research is to examine how the flight geometry of unmanned aerial systems (UASs) could affect the accuracy of photogrammetric processing products, concerning small erosion landforms that are a result of slope wash and temporary small streams formed by rain. In October 2021, three UAS flights with a different geometry were carried out in a hilly to a low-mountain area with an average altitude of about 650 m where erosion processes are observed. UAS imagery processing was carried out using structure-from-motion (SfM) photogrammetry. High-resolution products such as photogrammetric-based point clouds, digital surface models (DSMs) and orthophotos were generated. The obtained data were compared and evaluated by the root mean square error (RMSE), length measurement, cloud-to-cloud comparison, and 3D spatial GIS analysis of DSMs. The results show small differences between the considered photogrammetric products generated by nadir-viewing and oblique-viewing (45°—single strip and 60°—cross strips) geometry. The complex analysis of the obtained photogrammetric products gives an advantage to the 60°—cross strips imagery, in studying erosional terrains with slow slope morphodynamics. Full article

C-reactive protein is a well-studied host response biomarker, whose diagnostic performance depends on its accurate classification into concentration zones defined by clinical scenario-specific cutoff values. We validated a newly developed, bead-based, bound-free phase detection immunoassay (BFPD-IA) versus a commercial CE-IVD enzyme-linked immunosorbent assay (ELISA) kit and a commercial CE-IVD immunoturbidimetric assay (ITA) kit. The latter was performed on a fully automated DPC Konelab 60i clinical analyzer used in routine diagnosis. We classified 53 samples into concentration zones derived from four different sets of cutoff values that are related to antibiotic prescription scenarios in the case of respiratory tract infections. The agreements between the methods were ELISA/ITA at 87.7%, ELISA/BFPD-IA at 87.3%, and ITA/-BFPD-IA at 93.9%, reaching 98–99% in all cases when considering the calculated relative combined uncertainty of the single measurement of each sample. In a subgroup of 37 samples, which were analyzed for absolute concentration quantification, the scatter plot slopes’ correlations were as follows: ELISA/ITA 1.15, R² = 0.97; BFPD-IA/ELISA 1.12, R² = 0.95; BFPD-IA/ITA 0.95, R² = 0.93. These very good performances and the agreement between BFPD-IA and ITA (routine diagnostic), combined with BFPD-IA’s functional advantages over ITA (and ELISA)—such as quick time to result (~20 min), reduced consumed reagents (only one assay buffer and no washing), few and easy steps, and compatibility with nucleic-acid-amplification instruments—render it a potential approach for a reliable, cost-efficient, evidence-based point-of-care diagnostic test for guiding antibiotic prescriptions. Full article

Sandy slope erosion leads to coast degradation and exacerbates coastal zone instability and failure. As an eco-friendly engineering technology, microbial-induced calcium carbonate precipitation (MICP) can provide a protection method against sandy slope erosion. In this study, a series of flume tests were conducted to investigate the wave erosion resistance of the MICP-treated sandy slope. The penetration tests were conducted to measure the slope surface strength, and the calcium carbonate content was evaluated by the acid washing method. The scanning electron microscope (SEM) was employed to study the microstructures of MICP-treated sand particles. In addition, the influence of MICP treatment on the wave shape and the excess pore water pressure was also analyzed. Results show that after four MICP treatments, the erosion resistance of the slope is significantly promoted, and no apparent erosion occurs after wave actions. The penetration resistance is also improved after MICP treatments, and the maximum penetration resistance of untreated and four-time MICP-treated slopes are about 0.14 MPa and 2.04 MPa, respectively. The calcium carbonate content on the slope surface can reach 7%. SEM analyses indicate that the intergranular bridging calcium carbonate crystals promote the wave erosion resistance of the sandy slope. Full article

In the wake of Chernobyl and Fukushima accidents, radiocesium has become a radionuclide of most environmental concern. The ease with which this radionuclide moves through the environment and is taken up by plants and animals is governed by its chemical forms and site-specific environmental characteristics. Distinctions in climate and geomorphology, as well as ¹³⁷Cs speciation in the fallout, result in differences in the migration rates of ¹³⁷Cs in the environment and rates of its natural attenuation. In Fukushima areas, ¹³⁷Cs was strongly bound to soil and sediment particles, with its bioavailability being reduced as a result. Up to 80% of the deposited ¹³⁷Cs on the soil was reported to be incorporated in hot glassy particles (CsMPs) insoluble in water. Disintegration of these particles in the environment is much slower than that of Chernobyl-derived fuel particles. The higher annual precipitation and steep slopes in Fukushima-contaminated areas are conducive to higher erosion and higher total radiocesium wash-off. Among the common features in the ¹³⁷Cs behavior in Chernobyl and Fukushima are a slow decrease in the ¹³⁷Cs activity concentration in small, closed, and semi-closed lakes and its particular seasonal variations: increase in the summer and decrease in the winter. Full article

The flow–sediment relationship is important to understand soil erosion and sediment transport in severely eroded areas, such as Loess Plateau. Previous research focused on the variation and driving forces of runoff and sediment at the different scales in a watershed. However, the variations of the flow–sediment relationship on multispatial scales (slope, subgully, gully, and watershed scales) and multitemporal scales (annual, flood events, and flood process) were less focused. Taking the Peijiamao watershed, which includes whole slope runoff plot (0.25 ha, slope scale), branch gully (6.9 ha, subgully scale), gully (45 ha, gully scale), and watershed (3930 ha, watershed scale), four different geomorphic units located at the Chinese Loess Plateau, as the research site, a total of 31 flood events from 1986 to 2008 were investigated, and two flood process data were recorded across all the four geomorphic units. The results showed that on the annual timescale, the average sediment transport modulus and runoff depth at four scales exhibited a linear relationship, with determination coefficients of 0.81, 0.72, 0.74, and 0.77, respectively. At the flood event timescale, the relationships between sediment transport modulus and runoff depth at the gully and watershed scales could also be fitted with a linear relationship with high determination coefficients (from 0.77 to 0.99), but the determination coefficient at the slope scale was only 0.37 at the event scale. On the single rainfall event timescale, the flow–sediment relationship at the slope scale showed a figure-eight hysteretic pattern while those relationships at larger scales showed an anticlockwise loop hysteretic pattern. Under the same flow condition, the suspended sediment concentrations during the falling stage were significantly higher than those during the rising stage. Moreover, the difference was bigger as the spatial scale increased due to the wash loads in the downstream gullies, which favored the occurrence of hyper-concentration flow. The results of the study could provide useful insights into the temporal–spatial scale effects of sediment transport and their internal driving mechanisms at the watershed scale. Full article

Terracing is the oldest technique for water and soil conservation on natural hilly slopes. In Northern Thailand, terraced paddy fields were constructed long ago, but scientific questions remain on how terraced paddy fields and upland rice (non-terraced) differ for soil organic carbon (SOC) stocks, soil nutrients and soil erodibility. Therefore, this study aims to evaluate and compare SOC stocks, soil nutrients and soil erodibility between terraced paddy fields and upland rice at Ban Pa Bong Piang, Chiang Mai Province, Thailand. Topsoil (0–10 cm) was collected from terraced paddies and upland rice fields after harvest. Results showed that SOC stocks were 21.84 and 21.61 Mg·C·ha⁻¹ in terraced paddy and upland rice fields, respectively. There was no significant difference in soil erodibility between terraced paddies (range 0.2261–0.2893 t·h·MJ⁻¹·mm⁻¹) and upland rice (range 0.2238–0.2681 t·h·MJ⁻¹·mm⁻¹). Most soil nutrients (NH₄-N, NO₃-N, available K, available Ca and available Mg) in the terraced paddy field were lower than those in the upland rice field. It was hypothesized that the continuous water flows from plot-to-plot until lowermost plot caused dissolved nutrients to be washed and removed from the flat surface, leading to a short period for accumulating nutrients into the soil. An increase in soil erodibility was associated with decreasing SOC stock at lower toposequence points. This study suggested that increasing SOC stock is the best strategy to minimize soil erodibility of both cropping systems, while proper water management is crucial for maintaining soil nutrients in the terraced paddy field. Full article

Due to extreme rainfall in 2010 in the Lusatian Neisse River catchment area (in Poland), a flood event with a return period of over 100 years occurred, leading to the failure of the Niedów dam. The earth-type dam constructed for cooling the Turów power plant was washed away, resulting in the rapid release of nearly 8.5 million m³ of water and the flooding of the downstream area with substantial material losses. Here we analyze the conditions and causes of the dam’s failure, with special attention given to the mechanism and dynamics of the compound breaching process, in which the dam’s upstream slope reinforcement played a specific and remarkable role. The paper also describes a numerical approach for simulating a combined flood event downstream from the dam with the use of a two-dimensional hydrodynamic model (MIKE21). Considering the specific local conditions, i.e., wide floodplain, meandering character of the main channel, embankment overtopping, and available data set, an iterative solution of the unsteady state problem is proposed. This approach enables realistic flood propagation estimates to be delivered, the dam breach outflow to be reconstructed, and several important answers concerning the consequences of the dam’s failure to be provided. Finally, the paper presents the reconstruction of the dam that is more resilient to extreme hydrological conditions under changing climate. Full article

Mountainous regions present numerous obstacles to agriculture. These include the terrain, which is associated with surface erosion, as well as surface runoff, which washes away plant nutrients and weak soil. Spatial analysis is currently used in the study of various stochastic variables, especially those of high priority for soil water properties. Small watershed and basin-scale models were used to simulate the quantity of surface run-off, groundwater and predict the environmental impact of land use and land management practices. A new generation of the distributed hydrological models has greatly broadened simulation fields to soil and water diversified situations. The study also measured declines in slope and grain size distribution, factors impacting surface erosion and surface runoff. Multivariate statistics (canonical analysis) showed that soil moisture was most correlated both with agricultural land and forests, which is why it was used to create the model of spatial distribution. The model showed that salinity has the smallest forecast error in modeling, and thus best corresponds with the soil moisture. It is important to make a correct diagnosis of soil properties, and the degree of degradation. The assessment of the physiographic parameters of a basin will contribute to the development of proper usage and determine the quality of the water in the soil, which will be essential for forest resources and agricultural land in mountain areas exposed to surface erosion. Full article

Renal cell carcinoma (RCC) is the most common and a highly aggressive type of malignant renal tumor. In this manuscript, we aim to identify and integrate the optimal discriminating morphological, textural, and functional features that best describe the malignancy status of a given renal tumor. The integrated discriminating features may lead to the development of a novel comprehensive renal cancer computer-assisted diagnosis (RC-CAD) system with the ability to discriminate between benign and malignant renal tumors and specify the malignancy subtypes for optimal medical management. Informed consent was obtained from a total of 140 biopsy-proven patients to participate in the study (male = 72 and female = 68, age range = 15 to 87 years). There were 70 patients who had RCC (40 clear cell RCC (ccRCC), 30 nonclear cell RCC (nccRCC)), while the other 70 had benign angiomyolipoma tumors. Contrast-enhanced computed tomography (CE-CT) images were acquired, and renal tumors were segmented for all patients to allow the extraction of discriminating imaging features. The RC-CAD system incorporates the following major steps: (i) applying a new parametric spherical harmonic technique to estimate the morphological features, (ii) modeling a novel angular invariant gray-level co-occurrence matrix to estimate the textural features, and (iii) constructing wash-in/wash-out slopes to estimate the functional features by quantifying enhancement variations across different CE-CT phases. These features were subsequently combined and processed using a two-stage multilayer perceptron artificial neural network (MLP-ANN) classifier to classify the renal tumor as benign or malignant and identify the malignancy subtype as well. Using the combined features and a leave-one-subject-out cross-validation approach, the developed RC-CAD system achieved a sensitivity of $95.3\%\pm 2.0\%$, a specificity of $99.9\%\pm 0.4\%$, and Dice similarity coefficient of $0.98\pm 0.01$ in differentiating malignant from benign tumors, as well as an overall accuracy of $89.6\%\pm 5.0\%$ in discriminating ccRCC from nccRCC. The diagnostic abilities of the developed RC-CAD system were further validated using a randomly stratified 10-fold cross-validation approach. The obtained results using the proposed MLP-ANN classification model outperformed other machine learning classifiers (e.g., support vector machine, random forests, relational functional gradient boosting, etc.). Hence, integrating morphological, textural, and functional features enhances the diagnostic performance, making the proposal a reliable noninvasive diagnostic tool for renal tumors. Full article

Inadequate management practices for solid waste and wastewater are some of the main causes of eutrophication globally, especially in regions where intensive livestock, agricultural, and industrial activities are coupled with inexistent or ineffective waste and wastewater treatment infrastructure. In this study, a methodological approach is presented to spatially assess the trophic state of large territories based on public water quality databases. The trophic state index (TSI) includes total nitrogen, total phosphorus, chlorophyll A, chemical oxygen demand, and Secchi disk depth values as water quality indicators. A geographical information system (GIS) was used to manage the spatiotemporal attributes of the water quality data, in addition to spatially displaying the results of TSI calculations. As a case study, this methodological approach was applied to determine the critical regions for mitigating eutrophication in the state of Jalisco, Mexico. Although a decreasing trend was observed for the TSI values over time for most subbasins (2012–2019), a tendency for extreme hypereutrophication was observed in some regions, such as the Guadalajara metropolitan area and the Altos region, which are of high economic relevance at the state level. A correlation analysis was performed between the TSI parameters and rainfall measurements for all subbasins under analysis, which suggested a tendency for nutrient wash-off during the rainy seasons for most subbasins; however, further research is needed to quantify the real impacts of rainfall by including other variables such as elevation and slope. The relationships between the water quality indicators and land cover were also explored. The GIS methodology proposed in this study can be used to spatially assess the trophic state of large regions over time, taking advantage of available water quality databases. This will enable the efficient development and implementation of public policies to assess and mitigate the eutrophication of water sources, as well as the efficient allocation of resources for critical regions. Further studies should focus on applying integrated approaches combining on-site monitoring data, remote sensing data, and machine learning algorithms to spatially evaluate the trophic state of territories. Full article

Analysis of two small semi-mountainous catchments in central Evia island, Greece, highlights the advantages of Unmanned Aerial Vehicle (UAV) and Terrestrial Laser Scanning (TLS) based change detection methods. We use point clouds derived by both methods in two sites (S1 & S2), to analyse the effects of a recent wildfire on soil erosion. Results indicate that topsoil’s movements in the order of a few centimetres, occurring within a few months, can be estimated. Erosion at S2 is precisely delineated by both methods, yielding a mean value of 1.5 cm within four months. At S1, UAV-derived point clouds’ comparison quantifies annual soil erosion more accurately, showing a maximum annual erosion rate of 48 cm. UAV-derived point clouds appear to be more accurate for channel erosion display and measurement, while the slope wash is more precisely estimated using TLS. Analysis of Point Cloud time series is a reliable and fast process for soil erosion assessment, especially in rapidly changing environments with difficult access for direct measurement methods. This study will contribute to proper georesource management by defining the best-suited methodology for soil erosion assessment after a wildfire in Mediterranean environments. Full article