Search Results (32,870)

Among the various renewable-powered pathways for green hydrogen production, solar photovoltaic (PV) technology represents a particularly promising option due to its environmental sustainability, widespread availability, and declining costs. However, the inherent intermittency of solar irradiance presents operational challenges for electrolyzers, particularly in terms of stability and efficiency. This study presents a MATLAB-based dynamic model of an off-grid, DC-coupled solar PV-Anion Exchange Membrane (AEM) electrolyzer system, with a specific focus on realistically estimating hydrogen output. The model incorporates thermal energy management strategies, including electrolyte pre-heating during startup, and accounts for performance degradation due to load cycling. The model is designed for a comprehensive analysis of hydrogen production by employing a 10-year time series of irradiance and ambient temperature profiles as inputs. The results are compared with two simplified scenarios: one that does not consider the equipment response time to variable supply and another that assumes a fixed start temperature to evaluate their impact on productivity. Furthermore, to limit the effects of degradation, the algorithm has been modified to allow the non-sequential activation of the stacks, resulting in an improvement of the single stack efficiency over the lifetime and a slight increase in overall hydrogen production. Full article

Soil moisture is a key factor in the exchange of energy and matter between the soil and atmosphere, playing a vital role in the hydrological cycle and agricultural management. Traditional monitoring methods are limited in achieving large-scale, real-time observations, while deep learning offers new avenues to model the complex nonlinear relationships between spectral features and soil moisture content. This study focuses on the Wei-Ku Oasis in Xinjiang, using multi-source remote sensing data (Landsat series and Sentinel-1) and in situ multi-layer soil moisture measurements. The BOSS feature selection algorithm was applied to construct 46 feature parameters, including vegetation indices, soil indices, and microwave indices, and to identify optimal variable sets for each depth. Convolutional Neural Network (CNN), Long Short-Term Memory (LSTM), and their hybrid model (CNN-LSTM) were used to build soil moisture inversion models at various depths. Their performances were systematically compared on both training and testing sets, and the optimal model was used for spatiotemporal mapping. The results show that the CNN-LSTM-based multi-depth soil moisture inversion model achieved superior performance, with the 0–10 cm model showing the highest accuracy and a testing R² of 0.64, outperforming individual models. The testing R² values for the soil moisture inversion models at depths of 10–20 cm, 20–40 cm, and 40–60 cm were 0.59, 0.54, and 0.59, respectively. According to the mapping results, soil moisture in the 0–60 cm profile of the Wei-Ku Oasis exhibited a vertical gradient, increasing with depth. Spatially, soil moisture was higher in the central oasis and lower toward the periphery, forming a “center-high, edge-low” pattern. This study provides a high-accuracy method for multi-layer soil moisture remote sensing in arid regions, offering valuable data support for oasis water resource management and precision irrigation planning. Full article

Chrysanthemum has a long history of medicinal use with rich germplasm resources and extensive cultivation. Traditional chrysanthemum cultivation involves complex patterns and long flowering periods, with the ongoing expansion of planting areas complicating statistical surveys. Currently, reliable, timely, and universally applicable standardized monitoring methods for chrysanthemum cultivation areas remain underdeveloped. This research employed 16 m resolution satellite imagery spanning 2021 to 2023 alongside 2 m resolution data acquired in 2022 to quantify chrysanthemum cultivation extent across Sheyang County, Jiangsu Province, China. After evaluating multiple classifiers, Maximum Likelihood Classification was selected as the optimal method. Subsequently, time-series-based post-classification processing was implemented: initial cultivation information extraction was performed through feature comparison, supervised classification, and temporal analysis. Accuracy validation via Overall Accuracy, Kappa coefficient, Producer’s Accuracy, and User’s Accuracy identified critical issues, followed by targeted refinement of spectrally confused features to obtain precise area estimates. The chrysanthemum cultivation area in 2022 was quantified as 46,950,343 m² for 2 m resolution and 46,332,538 m² for 16 m resolution. Finally, the conversion ratio characteristics between resolutions were analyzed, yielding adjusted results of 38,466,192 m² for 2021 and 47,546,718 m² for 2023, respectively. These outcomes demonstrate strong alignment with local agricultural statistics, confirming method viability for chrysanthemum cultivation area computation. Full article

Background: Pelvic fractures are complex injuries often associated with significant morbidity and mortality, requiring multidisciplinary management. This case series highlights the presentation, management strategies, and outcomes of patients with pelvic fractures treated at our institution. Methods: The medical records of 13 patients diagnosed with pelvic fractures from 1 January 2020 through 31 December 2023 were retrospectively reviewed. Demographic data, mechanism of injury, fracture pattern, associated injuries, treatment modalities, and outcomes were analyzed. Results: A total of 13 patients were included in the study, with ages ranging from 18–95 years. Six of the patients were male and seven were female. The most common mechanisms of injury were falls and pedestrians struck by vehicles. Associated injuries included traumatic brain injury (TBI), fractures including extremities, ribs, and vertebrae, visceral injury, and spinal cord injury. Treatment strategies ranged from conservative, non-surgical management to operative intervention, including interventional radiology embolization, external traction, open reduction and internal fixation (ORIF), and percutaneous screw stabilization. Additional interventions included chest tube placement, exploratory laparotomy, and craniectomy. Two patients died while in the hospital, one was discharged to a shelter, and the remaining 10 were discharged to various inpatient rehab facilities. Conclusions: Pelvic fractures pose significant clinical challenges due to their complexity and associated injuries. This case series underscores the importance of multidisciplinary intervention and treatment strategies in optimizing outcomes. Further studies should focus on the effectiveness of interventions, utilization of new technology, and multidisciplinary team planning. Full article

The efficient and rational development of hydropower in the Lancang–Mekong River Basin can promote green energy transition, reduce carbon emissions, prevent and mitigate flood and drought disasters, and ensure the sustainable development of the entire basin. In this study, based on publicly available hydrometeorological observation data and satellite remote sensing monitoring data from 2001 to 2020, a machine learning model of the Lancang–Mekong Basin was developed to reconstruct the basin’s hydrological processes, and identify the occurrence patterns and influencing mechanisms of water-related hazards. The results show that, against the background of climate change, the Lancang–Mekong Basin is affected by the increasing frequency and intensity of extreme precipitation events. In particular, Rx1day, Rx5day, R10mm, and R95p (extreme precipitation indicators determined by the World Meteorological Organization’s Expert Group on Climate Change Monitoring and Extreme Climate Events) in the northwestern part of the Mekong River Basin show upward trends, with the average maximum daily rainfall increasing by 1.8 mm/year and the total extreme precipitation increasing by 18 mm/year on average. The risks of flood and drought disasters will continue to rise. The flood peak period is mainly concentrated in August and September, with the annual maximum flood peak ranging from 5600 to 8500 m³/s. The Stung Treng Station exhibits longer drought duration, greater severity, and higher peak intensity than the Chiang Saen and Pakse Stations. At the Pakse Station, climate change and hydropower development have altered the non-drought proportion by −12.50% and +15.90%, respectively. For the Chiang Saen Station, the fragmentation degree of the drought index time series under the baseline, naturalized, and hydropower development scenarios is 0.901, 1.16, and 0.775, respectively. These results indicate that hydropower development has effectively reduced the frequency of rapid drought–flood transitions within the basin, thereby alleviating pressure on drought management efforts. The regulatory role of the cascade reservoirs in the Lancang River can mitigate risks posed by climate change, weaken adverse effects, reduce flood peak flows, alleviate hydrological droughts in the dry season, and decrease flash drought–flood transitions in the basin. The research findings can enable basin managers to proactively address climate change, develop science-based technical pathways for hydropower dispatch, and formulate adaptive disaster prevention and mitigation strategies. Full article

Most crops accumulate above-ground biomass (AGB) through photosynthesis, inspiring the development of the Photosynthetic Accumulation Model (PAM) and Simplified PAM (SPAM). Both models estimate AGB based on time-series optical vegetation indices (VIs) and canopy height. To further enhance the model performance and evaluate its applicability across different crop types, an improved PAM model (IPAM) is proposed with three strategies. They are as follows: (i) using numerical integration to reduce reliance on dense observations, ($ii$) introduction of Fibonacci sequence-based structural correction to improve model accuracy, and ($iii$) non-photosynthetic area masking to reduce overestimation. Results from both soybean and cotton demonstrate the strong performance of the PAM-series models. Among them, the proposed IPAM model achieved higher accuracy, with mean $R^2$ and RMSE values of 0.89 and 207 g/m² for soybean and 0.84 and 251 g/m² for cotton, respectively. Among the vegetation indices tested, the recently proposed Near-Infrared Reflectance of vegetation (NIRv) and Kernel-based normalized difference vegetation index (Kndvi) yielded the most accurate results. Both Monte Carlo simulations and theoretical error propagation analyses indicate a maximum deviation percentage of approximately 20% for both crops, which is considered acceptable given the expected inter-annual variation in model transferability. In addition, this paper discusses alternatives to height measurements and evaluates the feasibility of incorporating synthetic aperture radar (SAR) VIs, providing practical insights into the model’s adaptability across diverse data conditions. Full article

This study examines the influence of different printing orientations and infill settings on the strength and flexibility of components produced using resin-based 3D printing, particularly with masked stereolithography (MSLA). Using a common photopolymer resin and a widely available desktop MSLA printer, we produced and tested a series of samples with varying tilt angles and internal structures. To understand their mechanical behavior, we applied a custom bending test combined with high-precision deformation tracking through the GOM ARAMIS digital image correlation system. The results obtained clearly show that both the angle of printing and the density of the internal infill structure play a significant role in how much strain the printed parts can handle before breaking. Notably, a 75° orientation provided the best deformation performance, and infill rates between 60% and 90% offered a good balance between strength and material efficiency. These findings highlight how adjusting print settings can lead to stronger parts while also saving time and resources—an important consideration for practical applications in engineering, design, and manufacturing. Full article

The Chating Cu-Au and Magushan Cu-Mo deposits in Anhui province are two representative deposits within the recently defined Nanling-Xuancheng ore concentration area in the Middle and Lower Yangtze River Metallogenic Belt (MLYB). Magmatism and mineralization for the area are not well known at present due to a lack of in-depth studies on the petrogenesis of ore-bearing intrusive rocks and their relationship with deposits. Here, the ore-bearing intrusive rocks of the two deposits are investigated through analyses of whole-rock geochemistry and Sr-Nd isotopes, zircon U-Pb ages, and zircon Hf isotopes. The results reflect the two intrusions, both formed in the Early Cretaceous (138.9 ± 0.8 Ma and 132.2 ± 1.3 Ma). They belong to the sub-alkaline high-K calc-alkaline series, while trace elements are enriched in LILEs and LREE and depleted in HFSEs. However, the intrusions of the Chating deposit (I_sr = 0.7064–0.7068; ε_Nd(t) = −8.5–−7.3; ε_Hf(t) = −11.9–−7.0) have obviously different Sr-Nd-Hf isotopic compositions from the intrusions of the Magushan deposit (I_sr = 0.7079–0.7081; ε_Nd(t) = −5.7–−5.4; ε_Hf(t) = −5.4–−3.6). The characteristics indicate that the two intrusions were formed in the same diagenetic ages and tectonic settings and derived from a crust–mantle mixture with predominant mantle-derived materials. But the crust materials of sources are different, which further leads to different metallogenic elements, showing that the Chating deposit is enriched in Cu and Au, while the Magushan deposit is enriched in Mo. Moreover, the characteristics and magma sources of two intrusions and metallogenic elements correspond respectively to the Tongling Cu-Au polymetallic ore concentration area in the MLYB and the southern Anhui Mo polymetallic ore concentration area in the Jiangnan orogen. The correlation implies differences in magmatism and mineralization between the northwestern and southeastern parts of the Nanling-Xuancheng ore concentration area, demarcated by the Jiangnan Deep Fault. These variations were mainly controlled by the Pre-Sinian crustal basement. Full article

Background/Objectives: Avascular necrosis of the femoral head is a debilitating condition that, if left untreated, leads to progressive arthritis necessitating total hip replacement (THR). In the younger adult population, there is a drive towards joint-preserving procedures, particularly where alternative techniques such as core decompression or vascularised bone grafting are anticipated to fail. Proximal femoral osteotomy is a technique that aims to remove the necrotic segment from the weight bearing area. The presented review aims to examine the efficacy of this technique in the management of avascular necrosis of the femoral head, reporting both rates of conversion to total hip replacement and patient reported outcomes. Methods: This systematic review was conducted according to PRISMA guidelines. A search was conducted of PubMed, Ovid Medline, EMBASE, and the Cochrane Library using pre-defined search terms. Data were extracted, and descriptive data presented. Quality of each study was assessed using the NIH quality assessment tool for case series studies. Results: Fifty-three studies with data for 2686 osteotomies are presented. Progression of radiological arthrosis was present in 40% of cases, with 20.3% of patients having undergone conversion to THR at a mean of 75.4 months (range 20–132 months). Patient-reported outcome measures were recorded in 1416 patients, of which the Harris Hip Score was the most commonly utilised. This score improved from a mean of 58.3 to 84.4 at a mean follow-up of 102 months. Conclusions: Osteotomy represented a valid head-preserving technique in the armamentarium against avascular necrosis of the femoral head, with conversion to THR required in 20.3% of patients at 7 years. In those patients who did not require THR, PROMS were similar to the arthroplasty population. Full article

Accurately predicting the ionosphere’s Total Electron Content (TEC) is significant for ensuring the regular operation of satellite navigation and communication systems and space weather prediction. To further improve the accuracy of TEC prediction, this paper proposes a TEC prediction model based on the grid-optimized Gate Recurrent Unit (GRU). This model has the following main features: (1) it uses statistical learning methods to interpolate the missing data of TEC observations; (2) it constructs a sliding time window by using the multi-dimensional time series features of two types of solar activity indices to support modeling; (3) It adopts grid search combined with optimization of network depth, time step length, and other hyperparameters to significantly enhance the model’s ability to extract the characteristics of the ionospheric 11-year cycle and seasonal variations. Taking the EGLIN station as an example, the proposed model is verified. The experimental results show that the root mean square error of the GRU model during the period from 2019 to 2020 was 0.78 TECU, which was significantly lower than those of the CCIR, URSI, and statistical machine learning models. Compared with the other three models, the RMSE error of the GRU model was reduced by 72.73%, 72.64%, and 57.38%, respectively. The above research verifies the advantages of the proposed model in predicting TEC and provides a new idea for ionospheric modeling. Full article

Background: Double-valve infective endocarditis (DVIE) accounts for 15–20% of all endocarditis and represents a challenge due to the increased incidence of embolic events and congestive heart failure compared to infective endocarditis (IE) affecting one valve. This study aims to evaluate patients’ characteristics, surgical procedures, complications, and mortality associated with DVIE in our tertiary hospital in Italy. The Endocarditis Registry STEADY includes patients admitted with IE from January 2009 to March 2024 (n = 398). Sixty-three of them (16%) had DVIE. Methods: We conducted a retrospective single-center observational study, analyzing demographic, clinical, and microbiological data in DVIE patients, comparing those treated surgically (surgical group, SG) with those treated medically (non-surgical group, NSG). Results: The groups were homogeneous in age, microbiological yields, type of valve involved, and risk factors for infective endocarditis. The surgical group presented significantly more cancer history, intracardiac complications, and new-onset arrhythmias compared to the non-surgical group. Median hospital stay was similar in both groups. In SG, the most common postoperative complication was new rhythm disorders; other complications such as cardiac tamponade, pericardial effusion, and pneumothorax were rare. In-hospital mortality was similar between groups; however, one-year survival was higher in the surgical group (72% vs. 54%, p = 0.031). In our series, 16 patients were over 75 years old (25%), and 7 of them (44%) underwent cardiac surgery. One-year survival in the surgical group was also higher in this subgroup. Conclusions: Surgical treatment, when indicated, may improve the prognosis of patients with DVIE, including elderly patients. Full article

Objectives: To evaluate the safety and efficacy of the simultaneous implantation of a monofocal capsular bag-fixated and a trifocal supplementary sulcus-fixated intraocular lens (duet procedure) in eyes with co-existing pathologies undergoing cataract or refractive lens surgery. Methods: In total, 80 eyes of 40 consecutive patients, who underwent refractive lens exchange or cataract surgery and received the duet procedure due to minor co-pathologies, were included in this retrospective case series. Preoperative assessment comprised slit-lamp biomicroscopy, optical biometry, posterior-segment optical coherence tomography, corneal endothelial specular microscopy, corneal tomography, manifest refraction and distance and near visual acuity testing. Three months postoperatively, uncorrected distance (UDVA) and uncorrected near visual acuity (UNVA) were recorded. Results: The preoperative manifest refractive spherical equivalent (MRSE) was −0.31 ± 4.29 diopters (D), with a mean refractive astigmatism of −0.80 ± 0.60 D. At three months postoperatively, monocular UDVA and binocular UNVA significantly improved from 0.52 ± 0.42 logMAR and 0.32 ± 0.27 logMAR to 0.05 ± 0.09 logMAR and −0.03 ± 0.10 logMAR, respectively (both p < 0.0001). Conclusions: Reversible multifocality provided by the duet procedure appears to be a feasible option in eyes with mild co-existing pathologies, as it yields satisfactory visual and refractive outcomes with high safety. Full article

Small lakes (<10 km²) provide a range of ecosystem services but are often overlooked in both monitoring efforts and limnological studies. Remote sensing has been increasingly used to complement in situ monitoring or to provide water colour data for unmonitored inland water bodies. However, due to spatial, radiometric, and spectral constraints, it has been heavily focused on large lakes. Sentinel-2 MSI is the first sensor with the capability to consistently retrieve a wide range of essential water quality variables, such as chlorophyll-a concentration (chl-a) and water transparency, in small water bodies, and to provide long time series. Here, we provide and validate a framework for retrieving two variables, chl-a and turbidity, over lakes with diverse optical characteristics using Sentinel-2 imagery. It is based on GRS for atmospheric and sun glint correction, WaterDetect for water detection, and inversion models that were automatically selected based on two different sets of optical water types (OWTs)—one for each variable; for chl-a, we produced a blended product for improved spatial representation. To validate the approach, we compared the products with more than 600 in situ data from 108 lakes located in the Adour–Garonne river basins, ranging from 3 to ∼5000 ha, as well as remote sensing reflectance (Rrs) data collected during 10 field campaigns during the summer and spring seasons. Rrs retrieval (n = 65) was robust for bands 2 to 5, with MAPE varying from 15 to 32% and achieving correlation from 0.74 up to 0.92. For bands 6 to 8A, the Rrs retrieval was much less accurate, being influenced by adjacency effects. Glint removal significantly enhanced Rrs accuracy, with RMSE improving from 0.0067 to 0.0021 sr⁻¹ for band 4, for example. Water quality retrieval showed consistent results, with an MAPE of 56%, an RMSE of 11.4 mg m⁻³, and an r of 0.76 for chl-a, and an MAPE of 47%, an RMSE of 9.7 NTU, and an r of 0.87 for turbidity, and no significant effect of lake area or lake depth on retrieval errors. The temporal and spatial representations of the selected parameters were also shown to be consistent, demonstrating that the framework is robust and can be applied over lakes as small as 3 ha. The validated methods can be applied to retrieve time series of chl-a and turbidity starting from 2016 and with a frequency of up to 5 days, largely expanding the database collected by water agencies. This dataset will be extremely useful for studying the dynamics of these small freshwater ecosystems. Full article

In this study, a series of novel alkoxylated resorcinarenes were synthesized using secondary and tertiary alcohols under mild catalytic conditions involving iminodiacetic acid. Structural characterization, including single-crystal X-ray diffraction, confirmed the successful incorporation of branched alkyl chains and highlighted the influence of substitution patterns on molecular packing. Notably, detailed mass spectrometric analysis revealed that, under specific conditions, the reaction pathway may shift toward the formation of defined oligomeric species with supramolecular characteristics—an observation that adds a new dimension to the synthetic potential of this system. To complement the chemical analysis, selected derivatives were evaluated for biological activity, focusing on bacterial growth and biofilm formation. Using four clinically relevant strains (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis), we assessed both planktonic proliferation (OD₆₀₀) and biofilm biomass (crystal violet assay). Compound 2c (2-pentanol derivative) consistently promoted biofilm formation, particularly in S. aureus and B. subtilis, while having limited cytotoxic effects. In contrast, compound 2e and the DMSO control exhibited minimal impact on biofilm development. The results suggest that specific structural features of the alkoxy chains may modulate microbial responses, potentially via membrane stress or quorum sensing interference. This work highlights the dual relevance of alkoxylated resorcinarenes as both supramolecular building blocks and modulators of microbial behavior. Full article

In this study, a series of novel β-phenylalanine derivatives were synthesised and evaluated for their anticancer activity. The 3-(4-methylbenzene-1-sulfonamido)-3-phenylpropanoic acid (2) was prepared using β-phenylalanine as a core scaffold. The β-amino acid derivative 2 was converted to the corresponding hydrazide 4, which enabled the development of structurally diverse heterocyclic derivatives including pyrrole 5, pyrazole 6, thiadiazole 8, oxadiazole 11, triazoles 9 and 12 with Schiff base analogues 13 and series1,2,4-triazolo [3,4-b][1,3,4]thiadiazines 14. These modifications were designed to enhance chemical stability, solubility, and biological activity. All compounds were initially screened for cytotoxicity against the A549 human lung adenocarcinoma cell line, identifying N-[3-(3,5-dimethyl-1H-pyrazol-1-yl)-3-oxo-1-phenylpropyl]-4-methylbenzenesulfonamide (5) and (E)-N-{2-[4-[(4-chlorobenzylidene)amino]-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl]-1-phenylethyl}-4-methylbenzenesulfonamide (13b) as the most active. The two lead candidates were further evaluated in H69 and H69AR small cell lung cancer lines to assess activity in drug-sensitive and multidrug-resistant models. Schiff base 13b containing a 4-chlorophenyl moiety, retained potent antiproliferative activity in both H69 and H69AR cells, comparable to cisplatin, while compound 5 lost efficacy in the resistant phenotype. These findings suggest Schiff base derivative 13b may overcome drug resistance mechanisms, a limitation commonly encountered with standard chemotherapeutics such as doxorubicin. These results demonstrate the potential role of β-phenylalanine derivatives, azole-containing sulphonamides, as promising scaffolds for the development of novel anticancer agents, particularly in the context of lung cancer and drug-resistant tumours. Full article