Search Results (92,065)

This research concerns the manufacture and characterisation of epoxy composites with the addition of carbonisate, obtained by the pyrolysis of MDF (medium-density fibreboard) furniture board waste. The laminated composites were made by hand lamination, with the carbonisate used as a filler to improve the mechanical properties of the composite. The carbonisate was obtained by the thermal decomposition of MDF waste in an anaerobic environment by pyrolysis, which is an efficient method of waste management and material recycling. The resulting carbonisate was integrated into an epoxy resin matrix to investigate its potential as a reinforcing agent. The article describes a study on the hardness of epoxy-resin-based composites to which carbonisate was added in different fractions and percentages. The aim of the research was to test the possibility of using char as a component in improving the mechanical properties of epoxy composites with a view towards creating a durable recycled material with optimal parameters. As part of the study, a statistical analysis of the results of hardness measurements was carried out to accurately assess the effect of the quantity and size of the carbonate particles on the mechanical properties of the materials. The analysis identified significant differences between samples and verified the repeatability of the results. It was found that the addition of carbonisate to the A0 base sample (without the addition of carbonisate) leads to a significant hardening of the material. This was confirmed by the higher medians of samples A01 (carbonisate 5% with a 0.5 mm fraction), A02 (carbonisate 7.5% with a 0.5 mm fraction), and A03 (carbonisate 5% with a 1.0 mm fraction) compared to the base sample. The most homogeneous hardness was shown in sample A02, with the highest concentration of results and the lowest values of standard deviation and spread. The results indicated that the addition of carbonate significantly increased the hardness of the composite materials, with optimal stability achieved at 7.5% (by weight) of carbonate with a 0.5 mm fraction. The conducted research precisely determined the influence of the amount and characteristics of carbonisate particles on the mechanical properties of the materials, which enables the more effective designing of future composites. The statistical results provide a reliable basis for evaluating the potential applications of these materials in various industrial sectors, such as construction, automotive and aerospace, where high hardness and durability are important. Full article

Operational risk management (ORM) is crucial for every aviation organization. The assessment of operational risk (OR) is a critical area of study, as organizations must continuously evaluate and mitigate potential risks to maintain high levels of performance and safety. The motivation for writing this paper was to address the cognitive gap identified through literature analysis. The aim of this paper is to assess the effectiveness of operational residual risk assessment in general aviation (GA) organizations, with a specific focus on its role within the decision-making process to enhance flight safety in line with sustainability. By addressing a cognitive gap identified in the literature, this study seeks to determine whether current risk management practices adequately assess and mitigate residual risks, especially in organizations where operational risk is inherently high. Based on a literature review, the authors present adopted concepts of ORM and OR. The survey methodology involved a questionnaire on OR assessment, consisting of 32 questions completed by respondents twice—before and after 63 series of flights. The survey was carried out across two groups with significantly varying levels of flying experience (students and instructor pilots), with a particular focus on the influence of human factors. The conclusions are based on a comparative analysis of the difference in the results obtained after and before the series of flights in both surveyed groups. The survey was conducted in three selected general aviation organizations in Poland using nonprobability convenience sampling. The results demonstrate an overall significant underestimation of OR in both student and instructor groups. Therefore, it can be concluded that operational risk assessment in the selected organizations was not sufficiently effective. Additionally, it was shown that staff experience affected the effectiveness of OR assessment. Moreover, this study identified specific aspects of operational risk that were most underestimated. By addressing the cognitive gap, this study enhances both the theoretical and practical understanding of residual risk management, particularly in relation to safety and efficient resource use in aviation. It also offers the Operational Residual Risk Underestimation Index (ORRUI) as an actionable parameter developed to quantify and standardize the level of underestimation of operational residual risks in civil aviation. Full article

In order to address the challenges associated with optimizing multi-timescale operations and allocating ultra-short-term energy storage for HWP integration, this study takes into account both the economic and reliability aspects of the HWP integration base. It proposes a model for optimizing operations and allocating energy storage capacity, achieving optimization across long-term, short-term, and ultra-short-term operations for an MECB. Initially, operation optimization is implemented for an entire group of terraced hydropower plants by regulating them with annual regulating capabilities on a long-term timescale. The objectives are to maximize the daily average minimum output and annual power generation. Subsequently, short-term operation optimization focuses on maximizing HWP power feed-in, minimizing new energy power curtailment, and reducing residual load standard deviation while ensuring the guaranteed output optimization results for the long term. Finally, to mitigate ultra-short-term fluctuations in new energy, a HESS with specified capacity and power is configured with the goal of minimizing comprehensive costs. Additionally, to address the challenge of smoothing negative fluctuations, which is hindered by charging and discharging efficiency limitations, a variable baseline is introduced, deviating from the conventional 0 MW baseline. A simulation study based on data from the hydro–wind–PV hybrid project in the Beipanjiang River Basin, China, demonstrates the following: (1) after long-term system optimization, the total power generation capacity of the system increases by 9.68%, while the peak-to-valley difference in output is significantly reduced; (2) short-term system optimization significantly reduces both the average variance in residual loads and the amount of power curtailed over five representative days; (3) the system incorporates 398.62 MWh of lithium-ion battery storage with a power of 412.47 MW and 51.09 MWh of supercapacitor storage with a power of 223.32 MW, which, together, completely smooth out the ultra-short-term fluctuations in new energy output. Full article

Neuroendocrine prostate cancer (NEPC), an aggressive and lethal subtype of prostate cancer (PCa), often arises as a resistance mechanism in patients undergoing hormone therapy for prostate adenocarcinoma. NEPC is associated with a significantly poor prognosis and shorter overall survival compared to conventional prostate adenocarcinoma due to its aggressive nature and limited response to standard of care therapies. This transdifferentiation, or lineage reprogramming, to NEPC is characterised by the loss of androgen receptor (AR) and prostate-specific antigen (PSA) expression, and the upregulation of neuroendocrine (NE) biomarkers such as neuron-specific enolase (NSE), chromogranin-A (CHGA), synaptophysin (SYP), and neural cell adhesion molecule 1 (NCAM1/CD56), which are critical for NEPC diagnosis. The loss of AR expression culminates in resistance to standard of care PCa therapies, such as androgen-deprivation therapy (ADT) which target the AR signalling axis. This review explores the drivers of NE transdifferentiation. Key genetic alterations, including those in the tumour suppressor genes RB1, TP53, and PTEN, and changes in epigenetic regulators, particularly involving EZH2 and cell-fate-determining transcription factors (TFs) such as SOX2, play significant roles in promoting NE transdifferentiation and facilitate the lineage switch from prostate adenocarcinoma to NEPC. The recent identification of several other key novel drivers of NE transdifferentiation, including MYCN, ASCL1, BRN2, ONECUT2, and FOXA2, further elucidates the complex regulatory networks and pathways involved in this process. We suggest that, given the multifactorial nature of NEPC, novel therapeutic strategies that combine multiple modalities are essential to overcome therapeutic resistance and improve patient outcomes. Full article

This study aims to predict the economic transition pathway for alternative fuels in accordance with the 2023 IMO GHG Strategy goals. The assessment considers the impact of alternative fuel transition on fuel costs (∆COST_Fuel,t), carbon emission costs (∆COST_{CO2 eq,t}), and ship new/retrofit costs (∆COST_ship). The parameters and boundary conditions were set based on the current status and trends in the international shipping industry, as determined from previous research, to predict the economic transition pathway for alternative fuels. The results show that in 2050, with a standardized economic efficiency of 130%, profit will reach its maximum value, approximately −54,000 million USD. The study standardized fuel ΔCOST_{j, normalized}, and ΔNPV%_{j, normalized} as a basis for adjusting penetration rates. At this time, considering fuel costs and NPV%, the composition of alternative fuels is as follows: bio-LNG, bio-Methanol, e-LNG, e-Methanol, e-Ammonia, BD, and Fossil-LNG, with shares of 18.56%, 4.00%, 25.64%, 6.00%, 10.00%, 28.00%, and 0%, respectively. Compared to conventional marine fuel HFO, the increase ranges from 23.54% to 69.50% in the 2030s, 0.52% to 0.55% in the 2040s, and decreases by 6.88%– 14.69% in 2050. Using more LNG and BD in the 2040s and 2050 is an alternative way to achieve a better economic fuel transition. Moreover, the economic penetration rate combination set in this study can achieve sufficiently small ∆COST_T,t and sufficiently large NPV_Δt under specific assumptions and boundary conditions, rather than an absolute minimum ∆COST_T,t or the absolute maximum NPV_Δt. The results revealed that no single alternative fuel has a comprehensive advantage in reducing carbon intensity and economic performance at all times. Given the uncertainties in the supply chain, cost-effectiveness, and infrastructure for Methanol and Ammonia, LNG and BD play a crucial role in the transition of international shipping fuels. Our work provides a fundamental and comprehensive prediction of fuel transition based on the current status and trends in the international shipping industry. Full article

The synthesis of tetra- and pentanorlabdane compounds with rearranged cycle B based on commercially available (+)-sclareolide is reported. Desired compounds were prepared from intermediate ketones via Baeyer–Villiger oxidation. The structures of synthesized compounds were confirmed by spectral IR, 1D (¹H, ¹³C, and DEPT), and 2D (H-COSY, H,C-HSQC, H,C-HMBC, H,N-HMBC, NOESY) NMR analyses, mass-spectrometry and single crystal X-rays diffraction. Two out of the four synthesized compounds showed high antifungal and antibacterial activities comparable to and exceeding standard antifungal (caspofungin) and antibacterial (kanamycin) agents. DFT calculations show that in gas and DCM, compound 4 is more stable than 3 with a difference in the Gibbs free energy of 23.3 kJ/mol and 20.7 kJ/mol, respectively. In water and methanol, compound 3 is slightly more stable, by 2.4 kJ/mol and 2.78 kJ/mol, respectively. Molecular docking to four targets DNA gyrase from E. coli (1KZN), Fabz from P. aeruginosa (1U1Z), dihydrofolate reductase from C. albicans (3QLS) and MurB from E. coli (2Q85) showed good agreement with the results of in vitro evaluation and confirmed the biological activity of compounds 3 and 4, with binding affinities comparable and for some targets exceeding that of Caspofungin and Kanamycin. Full article

Cloud image segmentation is a technique that divides images captured by meteorological satellites or ground-based observations into different regions or categories. By extracting the distribution, shape, and dynamic features of clouds, it provides precise data support for the meteorological and environmental fields, significantly influencing photovoltaic (PV) power generation forecasting, astronomical telescope observatory site selection, and weather forecasting. A ground-based cloud image segmentation model based on an improved U-Net is proposed, which adopts an overall encoder–decoder structure. In the encoder phase, this paper constructs a dilated convolution–atrous spatial pyramid pooling (ASPP)–dilated convolution structure to enhance early cloud feature extraction. Dilated convolution is a novel type of convolution that expands the receptive field by inserting holes into standard convolution, thereby capturing a larger range of contextual information. ASPP maintains high resolution while paying attention to both local details and global structures of the image. In the decoder stage, the bicubic interpolation method is used for up-sampling to restore the feature map resolution and improve the clarity of the segmented image. The bicubic interpolation method refers to the use of cubic polynomial functions to interpolate the pixel values of the input image. In addition, this paper designs a novel skip connection layer structure between the encoder and decoder, composed of a depthwise separable path (DS path) and an improved channel spatial attention module (Im-CSAM) connected in sequence. The DS path combines depthwise separable convolutions and residual structures to facilitate information exchange between high-level and low-level features. The Im-CSAM is a modular attention mechanism that focuses on important cloud features in spatial and channel dimensions to enhance segmentation accuracy. Experiments show that compared to the traditional U-Net, the accuracy, precision, and MIoU of this model improved by 2.2%, 4.1%, and 5.0%, respectively, in the SWINySEG dataset, and by 3.2%, 3.6%, and 5.8%, respectively, in the TCDD dataset, proving that the improved method has a better generalization ability and segmentation performance. Full article

In order to solve the dietary problems of patients with dysphagia, a mathematical model for predicting extrusion pressure is established. The predictive model parameters are determined with the aid of the finite element method, and a 3D printing nozzle capable of printing nutrient-rich sandwich food is designed according to the predictive model. Pumpkin puree and minced pork are verified according to IDDSI standards. Finally, the accuracy of the predictive model and the printing effect of the design nozzle are verified by extrusion and printing experiments, respectively. The results show that four groups of simulation experiments reveal that the extrusion pressure increases by 15.6%, 13.5%, 12.7% and 12.4%, respectively, with a 1 cm increase in nozzle length. When the nozzle length is in the range of 1–5 cm, the extrusion pressure increases with the increase of the volume flow rate in the extrusion cylinder. The extrusion speed has little correlation with the length of the nozzle outlet, but for every 1 cm³/s increase in the inlet volume flow rate, the extrusion speed increases by about 1.5%. The finite element simulation experiment determines that the parameters of the prediction model are σ₀ = 0.6, α = 1.1, m = 0.21, τ₀ = 0, β = 0.52 and n = 0.2; the error between the predictive value and the experimental value is 15%, and the printed sandwich food has smooth lines, good molding and complies with IDDSI standards. Full article

Considerable variation in soil often occurs within and across production fields, which can significantly impact farming input management strategies. Optimizing resource utilization while enhancing crop productivity is critical for achieving Sustainable Development Goals (SDGs). This paper proposes a low-cost retrofittable Variable Rate Applicator Controller (VRAC) designed to leverage soil variability and facilitate the adoption of Variable Rate Technologies. The controller operates using a Raspberry Pi platform, RTK—Global Navigation Satellite System (GNSS), a stepper motor, and an anti-slip wheel encoder. The VRAC allows precise, on-the-fly control of the Variable Rate application of farming inputs utilizing an accurate GNSS to pinpoint geographic coordinates in real time. A wheel encoder measures accurate distance travel, providing a real-time calculation of speed with a slip-resistant wheel design for precise RPM readings. The Raspberry Pi platform processes the data, enabling dynamic adjustments of variability based on predefined maps, while the motor driver controls the motor’s RPM. It is designed to be plug-and-play, user-friendly, and accessible for a broader range of farming practices, including seeding rates, dry fertilizer, and liquid fertilizer application. Data logging is performed from various field sensors. The controller exhibits an average of 0.864 s for rate changes from 267 to 45, 45 to 241, 241 to 128, 128 to 218, and 218 to 160 kg/ha at speeds of 8, 11, 16, 19, 24, and 32 km/h. It has an average coefficient of variation of 4.59, an accuracy of 97.17%, a root means square error (RMSE) of 4.57, an R square of 0.994, and an average standard deviation of 1.76 kg for seeding discharge. The cost-effectiveness and retrofitability of this technology offer an increase in precision agriculture adoption to a broader range of farmers and promote sustainable farming practices. Full article

Objectives: This systematic review evaluates the effectiveness of fecal microbiota transplantation (FMT) in treating Clostridioides difficile infection (CDI) in mouse models using a metabolomics-based approach. Methods: A comprehensive search was conducted in three databases (PubMed, Scopus, Google Scholar) from 10 April 2024 to 17 June 2024. Out of the 460 research studies reviewed and subjected to exclusion criteria, only 5 studies met all the inclusion criteria and were analyzed. Results: These studies consistently showed that FMT effectively restored gut microbiota and altered metabolic profiles, particularly increasing short-chain fatty acids (SCFAs) and secondary bile acids, which inhibited C. difficile growth. FMT proved superior to antibiotic and probiotic treatments in re-establishing a healthy gut microbiome, as evidenced by significant changes in the amino acid and carbohydrate levels. Despite its promise, variability in the outcomes—due to factors such as immune status, treatment protocols, and donor microbiome differences—underscores the need for standardization. Rather than pursuing immediate standardization, the documentation of factors such as donor and recipient microbiome profiles, preparation methods, and administration details could help identify optimal configurations for specific contexts and patient needs. In all the studies, FMT was successful in restoring the metabolic profile in mice. Conclusions: These findings align with the clinical data from CDI patients, suggesting that FMT holds potential as a therapeutic strategy for gut health restoration and CDI management. Further studies could pave the way for adoption in clinical practice. Full article

IgA nephropathy (IgAN), first described in 1968, is one of the most common forms of glomerulonephritis and can progress to end-stage kidney disease (ESKD) in 25 to 30 percent of patients within 20 to 25 years from the onset. It is histologically characterized by mesangial proliferation with prominent IgA deposition. The prognosis may be difficult to predict, but important risk factors for disease progression of kidney disease have been recognized: usually proteinuria above 0.75–1 g/day with or without hematuria, hypertension, high-risk histologic features (such as crescent formation, immune deposits in the capillary loops, mesangial deposits, glomerulosclerosis, tubular atrophy, interstitial fibrosis, and vascular disease), and a reduced Glomerular Filtration Rate (GFR). In the absence of reliable specific biomarkers, current standards of care are addressed to decrease proteinuria, as a surrogate endpoint, and control blood pressure. For a long time, corticosteroids have been considered the only cure for proteinuric patients or those at risk of progression to ESKF; however, unfortunately, like other immunosuppressive agents, they are burdened with high collateral risks. Therefore, optimal treatment remains a challenge, even if, to date, clinicians have many more options available. Here, we will review the main therapies proposed, such as the stronghold of RAAS inhibition and the use of SGLT2 inhibitors; it is expected that ongoing clinical trials may find other therapies, apart from corticosteroids, that may help improve treatment, including both immunosuppressive monoclonal antibodies and other strategies. At the current time, there are no disease-specific therapies available for IgAN, because no largescale RCTs have demonstrated a reduction in mortality or in major adverse kidney or cardiovascular events with any therapy. Full article

Hypericum perforatum, also known as St. John’s Wort, pericon, or yellow grass, is known for its antidepressant potential. It could represent a natural alternative to current pharmacological antidepressant treatments, which have a high incidence of side effects in patients and therefore lead to early dropouts. Through a bibliographic revision of clinical trials and information collected from scientific articles during the first period of 2020, we aimed to evaluate whether its administration could be beneficial in the treatment of mild-to-moderate depression, with fewer side effects compared to synthetic drugs. Among the main components, hypericin and hyperforin have been related to the observed antidepressant activity; therefore, their possible mechanism of action was reviewed and highlighted. Furthermore, patients receiving Hypericum extracts were less likely to withdraw from studies because of adverse effects compared to those receiving older standard antidepressants. This review aims to provide suggestions for an alternative treatment of mild-to-moderate depression disorder under the supervision of a medical doctor, since, although it appears to be a potentially efficient treatment with a low presence of adverse effects in comparison to synthetic antidepressants, it might also interact with other medications and lead to therapeutic failures if misused for self-medication. Full article

Immediate loading implant surgery has emerged as a significant advancement in the rehabilitation of edentulous patients. This approach requires meticulous planning and precise execution to ensure successful outcomes. Transferring established intermaxillary and occlusal relationships to the definitive prostheses can be challenging. However, with a digital approach, this procedure can be standardized in cases of fully guided surgery with a flapless technique or by using disposable guides. Conversely, when extensive open flap implant surgery is required, such as in the treatment of severely atrophic patients (e.g., with zygomatic implants or simultaneous bone augmentation), the digital workflow can be demanding. The impression reference technique was proposed to enhance the digital workflow for immediate loading in zygomatic implant rehabilitation. This study aims to describe the impression reference technique, applied to both upper and lower jaws for immediate loading open flap rehabilitations, using standard implants. Full article

Background/objectives: Lower limb cutaneous reflex amplitudes can modulate across gait, which helps humans adjust rhythmic motor outputs to maintain balance in an ever-changing environment. Preliminary evidence suggests people who suffer from repetitive ankle sprains and residual feelings of giving way demonstrate altered cutaneous reflex patterns in the gastrocnemius. However, before cutaneous reflex assessment can be implemented as a clinical outcome measure, there is a need to substantiate these early findings by measuring reflex amplitudes across longer latency periods and exploring the variability of reflexes within each subject. Methods: Forty-eight subjects with and without chronic ankle instability (CAI) walked on a treadmill at 4 km/h while activity of the lateral gastrocnemius (LG) was measured via surface electromyography. Non-noxious stimulations were elicited randomly to the ipsilateral sural nerve at the mid-stance phase of gait, and reflex amplitudes were calculated offline by comparing muscle activity during unstimulated and stimulated gait cycles. Two primary outcome measures were compared between groups at the middle latency (MLR: 80–120 ms) and late latency (LLR: 120–150 ms) time windows: (1) average reflex amplitudes and (2) standard deviation of reflex amplitudes for each subject across 10 trials. Results: Both groups demonstrated an equal amount of LG inhibition at the MLR and LG facilitation at the LLR. However, subjects with CAI showed significantly higher variability in LLR amplitude across trials than healthy controls. Conclusions: Increased variability of cutaneous reflex amplitudes may relate to symptoms associated with CAI. These findings suggest that reflex variability following sural nerve stimulation could serve as an objective measure to track treatment progress in patients with CAI, offering clinicians a new tool for conducting rehabilitation assessments in a controlled environment. Full article

The extraction of device-independent color values from affordable and accessible digital images based on a standard color space system is crucially necessary for agricultural applications, where color information for plant monitoring or diagnostics is required. This study aimed to develop a transformation matrix for obtaining XYZ color coordinates from the RGB values of digital images for agricultural applications. The calibration procedure was based on Munsell and Macbeth color charts. The color coordinates of eight color charts were measured, and the transformation matrices were built. Leaf samples of six different plants were used and compared based on the proposed transformation technique. The actual XYZ values of plant leaves were measured, and the RGB values were derived from the digital images. The results indicate that the Macbeth color chart with 24 colors had the best performance, with an average ∆ELAB and CIEDE2000 of less than 1.77 and 1.97, respectively. The findings demonstrate that the proposed transformation matrix was successful in converting RGB values to XYZ values and can be employed as a quick, easy, and inexpensive technique for obtaining standard color information. Full article