Search Results (2,434)

Fats, oils, and grease (FOG) deposits are hardened, sticky, insoluble solids that accumulate in sewage systems globally. These deposits contribute to pipe blockages and sanitary sewer overflows, releasing pathogens and pollutants into the environment, posing significant environmental and public health risks. Current removal methods are labor-intensive and costly, emphasizing the need for alternatives. While biological strategies offer a viable alternative, the microbial breakdown of FOG is poorly understood. In this study, we evaluated the potential of individual microbial strains and synthetic microbial communities to biodegrade wastewater-derived FOG deposit samples. These biological agents were applied to a range of FOG samples, and biodegradation was assessed through visual observations such as color change or gas bubbles, particle size, cell counts, pH, weight loss, and changes in fatty acid profile. Results demonstrate that microbial augmentation can enhance FOG degradation, offering an alternative or complementary approach for reducing maintenance burdens and preventing sewer blockages. Full article

In the hydropower sector, accurate estimation of short-term reservoir inflows is an essential element to ensure efficient and safe management of water resources. Short-term forecasting supports the optimization of energy production, prevention of uncontrolled water discharges, planning of equipment maintenance, and adaption of operational strategies. In the absence of data on topography, vegetation, and basin characteristics (required in distributed or semi-distributed models), data-driven approaches can serve as effective alternatives for inflow prediction. This study proposes a novel hybrid approach that reverses the conventional LSTM (Long Short-Term Memory)—ARIMA (Autoregressive Integrated Moving Average) sequence: LSTM is first used to capture nonlinear hydrological patterns, followed by ARIMA to model residual linear trends.The model was calibrated using daily inflow data in the Izvorul Muntelui–Bicaz reservoir in Romania from 2012 to 2020, tested for prediction on the day ahead in a repetitive loop of 365 days corresponding to 2021 and further evaluated through multiple seven-day forecasts randomly selected to cover all 12 months of 2021. For the tested period, the proposed model significantly outperforms the standalone LSTM, increasing the R² from 0.93 to 0.96 and reducing RMSE from 9.74 m³/s to 6.94 m³/s for one-day-ahead forecasting. For multistep forecasting (84 values, randomly selected, 7 per month), the model improves R² from 0.75 to 0.89 and lowers RMSE from 18.56 m³/s to 12.74 m³/s. Thus, the hybrid model offers notable improvements in multi-step forecasting by capturing both seasonal patterns and nonlinear variations in hydrological data. The approach offers a replicable data-driven solution for inflow prediction in reservoirs with limited physical data. Full article

With the increasing age and traffic load of highway networks in China, preventive maintenance has become a critical strategy for extending pavement service life and improving infrastructure sustainability. However, the lack of standardized post-evaluation systems has hindered the scientific assessment of maintenance effectiveness. This study proposes a systematic post-evaluation framework for highway preventive maintenance projects based on the Hazard Analysis and Critical Control Points (HACCP)-Inspired methodology (Applying Principles of Hazard Analysis and CCP Identification). Adopting a full life-cycle perspective, the framework identifies critical control points (CCPs) across pre-, mid-, and post-implementation phases, targeting six key dimensions: ecological and environmental hazards, resource utilization hazard, engineering safety risks, engineering quality risks, socioeconomic benefit hazards, and social living environment hazards. A multi-level evaluation indicator system is constructed using hierarchical clustering and weighted through the Analytic Hierarchy Process (AHP). The framework is applied to a preventive maintenance project on the Jinghuan Expressway in Tianjin, China, demonstrating strong practical applicability. The final evaluation score of 84.1 out of 100 confirms the technical adequacy of the project while revealing areas for improvement in clean energy adoption and substructure monitoring. This framework provides a robust basis for standardizing post-evaluation practices and promoting sustainable highway maintenance management. Full article

Regulatory T cells (Tregs) are a distinctive subset of CD4⁺ T cells critical in self-tolerance maintenance to prevent the development of autoimmunity. The mechanisms by which these cells provide immune regulation are numerous and, consequently, deeply involved in the pathogenesis of many autoimmune disorders. Treg-based adoptive cell transfer (ACT) therapy has generated interest as a novel, promising strategy to restore self-tolerance in autoimmunity. Polyclonal Treg-based ACT therapy was first implemented in clinical trials, presenting adequate safety profiles. Subsequent preclinical studies have shown antigen-specific Tregs to be safer and more effective than polyclonal approaches, so research has recently moved in this direction. Antigen-specificity can be conferred to Tregs by viral transduction of genes coding for engineered T cell receptors (eTCRs) or chimeric antigen receptors (CARs), with encouraging outcomes in different animal models of autoimmunity. This review focuses on the biology of Tregs, as well as on current preclinical and clinical data for Treg-based ACT in the field of autoimmunity. Full article

Understanding how environmental design and institutional trust shape perceived security in nightlife settings is essential for enhancing customer experiences and business sustainability. This study examines how surveillance, access control, territoriality, maintenance, and trust in police influence customers’ perceptions of security in nightlife establishments in Colombia, and how these perceptions affect satisfaction and revisit intentions. A survey was conducted involving 400 customers in nightlife venues in Guadalajara de Buga, using Likert scales to evaluate the constructs. Data were analyzed using partial least squares structural equation modeling; Results indicate that maintenance (β = 0.304), surveillance (β = 0.264), trust in police (β = 0.203), and territoriality (β = 0.184) significantly influence perceived security, while access control does not. Perceived security strongly impacts satisfaction (β = 0.662) and revisit intention (β = 0.641). The model explains 47% of the variance in perceived security, 43% in satisfaction, and 41% in revisit intention. These findings highlight the value of integrating environmental design and institutional trust within service marketing and crime prevention, showing that investments in design and maintenance can yield commercial benefits. The study offers guidance for owners seeking to improve customer satisfaction and loyalty through targeted strategies. Full article

Background/Objectives: Lamotrigine has been widely investigated in the treatment and prevention of the emergence of symptoms of depression in unipolar and bipolar depression. This work systematically appraises published and unpublished double-blind randomised controlled trials of lamotrigine to provide up-to-date guidance on the use of lamotrigine in the presence of depressive symptoms. Methods: Systematic searches identified 32 randomised controlled trials, of which 24 were included in the meta-analysis, involving 2257 patients and 2320 controls. Results: Evidence supports the use of lamotrigine in the acute phase of bipolar depression in monotherapy vs. placebo (SMD: 0.155; CI: 0.005–0.305) in the absence of significant heterogeneity and small study effects. In the prophylaxis of bipolar depression, lamotrigine reduced the risk of the emergence of depressive symptoms (RR: 0.78; CI: 0.63, 0.98) and prolonged the duration of symptoms survival (RR: 1.59; CI: 1.19, 2.11) compared to placebo, with no evidence of publication and small study bias. Lamotrigine was not found to be superior to lithium in the acute treatment and prophylaxis of bipolar depression. In the treatment of unipolar depressive episodes, with the inclusion in the analyses of three unpublished studies, lamotrigine was not superior to placebo in monotherapy and as adjunct treatment. There were no maintenance studies in unipolar depression. Conclusions: There is evidence supporting the use of lamotrigine in monotherapy as acute and prophylactic treatment of bipolar depression. Evidence of the use of lamotrigine in unipolar disorders is lacking. PROSPERO registration ID: CRD42025633709. Full article

Space robots are vital for in-orbit maintenance of large satellites, but dense payloads and complex surface structures pose challenges for safe crawling operations. This study proposes an improved trajectory planning framework for three-dimensional satellite surfaces. In the path search stage, the traditional A* algorithm is enhanced with traction cost, reflecting surface adhesion, and proximity cost, ensuring collision avoidance. The resulting comprehensive cost function integrates path length, safety, and feasibility, producing paths more consistent with real mobility constraints. In the smoothing stage, cubic B-spline curves refine the discrete path, with real-time collision detection embedded in the optimization of control points to prevent trajectory penetration. Simulations show that the method achieves millisecond-level planning, with path length reduced by 6.82% and trajectory smoothness significantly improved, eliminating the phenomenon of sharp turns with folded corners. The approach ensures continuous, stable, and collision-free movement of space robots, highlighting its potential for reliable in-orbit operations. Full article

Between April and May 2025, an outbreak of travel-associated Legionnaires’ disease (TALD) occurred, involving six cases at a hotel in Crete, Greece. Including two cases reported in 2023 and two additional cases from 2016 to 2017, ten cases were associated with this accommodation site. All TALD cases were reported by the European Legionnaires’ Disease Surveillance Network (ELDSNet). In compliance with the European Centre for Disease Prevention and Control (ECDC) surveillance and investigation protocols for hotels associated with the patient’s stay, local public health authorities conducted on-site inspections at the hotel by collecting water samples and performing risk assessments, while simultaneously recording the required epidemiological, environmental, and physicochemical data. A total of 181 statistically analyzed water samples showed positive rates for L. pneumophila of 12.71% (95% CI: 7.86–17.56) for (≥50 CFU/L) and 6.08% (95% CI: 2.60–9.56) for (≥1000 CFU/L). Risk assessments identified 18 stagnation points, systemic maintenance deficiencies, and high cumulative structural (30/52) and water (36/71) system risk scores. Low microbiological positivity of water samples does not necessarily equate to low risk, thus necessitating continuous risk assessment, implementation of Water Safety Plans (WSPs), and integrated monitoring by accommodation facilities to prevent LD cases. Full article

Background: Saharan dust intrusions (SDIs) are associated with poor air quality and adverse respiratory outcomes. However, their impact on real-world inhaler utilization remains insufficiently characterized. We aimed to examine the association between SDI and the dispensing of short-acting beta-agonists (SABA) and inhaled corticosteroid–long-acting beta-agonist (ICS–LABA) combinations in the Canary Islands, Spain. Methods: Pharmaceutical sales data for SABA and ICS–LABA were collected from 60 pharmacies in Santa Cruz de Tenerife (TF) and Las Palmas de Gran Canaria (GC) between June 2017 and May 2022. SDI days were identified based on daily PM₁₀ concentrations > 40 µg/m³ from the regional air quality monitoring network. Linear regression models evaluated associations between drug dispensations and SDI presence, frequency, and intensity, adjusting for seasonality (winter vs. summer). Results: Over 60 months, SABA sales were 14.8% lower in TF compared with GC, while ICS–LABA sales were 10.9% higher. SDI presence was associated with significantly higher ICS–LABA dispensations in both provinces (+5.7% in TF, +10.2% in GC), whereas no association was found for SABA. ICS–LABA sales correlated weakly but significantly with both SDI frequency and PM₁₀ levels. Seasonal analysis revealed stronger effects in winter, with ICS–LABA dispensations increasing by 14.3% (TF) and 9.6% (GC) during SDI months. For SABA, seasonal differences were independent of SDI exposure. Conclusions: SDIs in the Canary Islands are independently associated with increased dispensing of ICS–LABA maintenance therapy, particularly during winter months. Dispensing data offer a valuable population-level indicator of respiratory impact from natural airborne pollution and support the integration of environmental alerts into preventive respiratory care strategies. Full article

Building maintenance is a critical component of ensuring long-term performance, safety, and cost-efficiency in both conventional and critical infrastructures. While traditional contracting approaches have often led to inefficiencies and rigid procurement systems, recent developments in performance-based maintenance, digital technologies, and multi-objective optimization provide opportunities to enhance both operational reliability and energy performance. From a resilience perspective, the ability to sustain functionality, adapt maintenance intensity, and recover performance under resource or operational stress is essential for ensuring infrastructure continuity and resilience. This study develops and validates an optimization model for the operation and maintenance of large campus infrastructures, addressing the persistent imbalance between over-maintenance, where costs exceed optimal levels by up to 300%, and under-maintenance, which compromises performance continuity and weakens resilience over time. The model integrates maintenance efficiency indicators, building performance indices, and energy-efficiency retrofits, particularly LED-based lighting upgrades, within a multi-choice goal programming framework. Using datasets from 15 campuses comprising over 2000 buildings, the model was tested through case studies, sensitivity analyses, and simulations under varying facility life cycle expectancies. The facilities were analyzed for alternative life cycles of 25, 50, 75, and 90 years, and the design life cycle was set for 50 years. The results show that the optimized approach can reduce maintenance costs by an average of 34%, with savings ranging from 1% to 55% across campuses. Additionally, energy retrofit strategies such as LED replacement yielded significant economic and environmental benefits, with payback periods of approximately 2–2.5 years. The findings demonstrate that integrated maintenance and energy-efficiency planning can simultaneously enhance building performance, reduce costs, and support sustainability objectives, offering a practical decision-support tool for managing large-scale campus infrastructures. Full article

Fault prediction and diagnosis are critical for enhancing the maintenance and reliability of power system equipment, reducing operational costs, and preventing potential failures. In power transformers, periodic oil sampling and gas ratio analysis provide valuable insights for predictive maintenance and life-cycle assessment. Machine learning methods, such as XGBoost, have proven to deliver more accurate results, especially when historical data is limited. However, the performance of XGBoost is highly dependent on the optimization of its hyperparameters. To address this, this paper proposes an improved Particle Swarm Optimization (IPSO) method to optimize the hyperparameters of XGBoost for transformer fault diagnosis. The PSO algorithm is enhanced by introducing topology optimization, adaptively adjusting the acceleration factor, dividing the swarm into master–slave particle groups to strengthen search capability, and dynamically adjusting inertia weights using a linear adaptive strategy. IPSO is applied to optimize key hyperparameters of the XGBoost model, improving both its diagnostic accuracy and generalization ability. Experimental results confirm the effectiveness of the proposed model in enhancing fault prediction and diagnosis in power systems. Full article

Understanding and predicting the damage to concrete caused by microorganisms in aquatic environments is challenging, highlighting the need for effective, simple, and inexpensive preventative methods. This paper presents the results of a study on the effect of calcium stearate addition on the kinetics of mass transfer processes occurring in cement stone exposed to Aspergillus niger fungi under humid conditions. Calcium stearate was added into the cement mix during sample preparation at concentrations of 0.5% and 1% by cement weight. After curing, the cement stone surfaces were inoculated with Aspergillus niger. To investigate mass transfer processes during biodegradation, the samples were immersed in water. Calcium leaching from the cement stone was quantified using complexometric titration of the water, while the calcium content within the cement stone was determined by derivatographic analysis. The quantitative indicators of calcium leaching in water from cement stone with calcium stearate additives were 2.5 times lower. The profiles of calcium concentrations in the thickness of cement samples demonstrated an increase in the intensity of mass transfer under the influence of fungi and a significant decrease in the processes in hydrophobic cement stone. The values of the mass conductivity coefficients for fungal-infected samples in water differed by two orders of magnitude from 10⁻⁹ and 10⁻¹¹ [m²/s] for conventional and hydrophobic concrete. The mass transfer parameters (flow density, mass conductivity coefficients, and mass transfer coefficients) revealed a 3-fold slowdown in mass transfer processes during fungal exposure in cement stone with a hydrophobic additive compared with control samples. A mathematical model of concrete biocorrosion was used to predict the durability of concrete under humid conditions with fungal exposure. The predicted maintenance-free service life of concrete without additives is 15 years, whereas for hydrophobic concrete, it is 25 to 30 years. The research results are used in the design of concrete structures in conditions of high humidity, in the development of new compositions of hydrophobic concretes, to predict the service life of concrete structures, and in the creation of methods for preventing biological damage to concrete structures. Full article

Preeclampsia is a severe complication affecting both maternal and neonatal health and is becoming a significant global public health issue. As a vital steroid hormone, progesterone (P4) plays a crucial role during pregnancy and in regulating various physiological processes. Recent studies have indicated that P4 is not only involved in pregnancy maintenance, but may also be closely related to preeclampsia pathogenesis and prevention. Previous research has suggested that P4 may participate in the mechanism of preeclampsia by regulating vascular function, immune responses, and placental function. Moreover, key enzymes and metabolites involved in the synthesis and metabolism of P4 are also associated with preeclampsia onset. Additionally, the potential value of clinically applying P4 in preventing and treating preeclampsia has been shown; however, the corresponding clinical practices require further validation and optimization. This study aimed to review the physiological effects, pathological functions, and clinical applications of P4 in preeclampsia, providing evidence for future research and clinical practice. Full article

Background: Despite efforts to rely on arteriovenous fistulas/grafts for maintenance hemodialysis, a significant number of patients still depend on tunnel hemodialysis catheters for treatment. This poses a risk factor for central line-associated bloodstream infection (CLABSI) and, subsequently, vascular access compromise. Method: We conducted a retrospective study in five dialysis centers to determine the potential factors resulting in vascular access loss, CLABSI incidence, and microbe distribution patterns in Saudi Arabia at centers under the Ministry of National Guard Health Affairs. Adults who regularly received hemodialysis and had positive blood cultures between January 2019 and December 2023 were the subjects of the study. Results: Our study identified the presence of tunnel infection (p < 0.001), the presence of a Gram-negative pathogen (p = 0.036), and a high body mass index (BMI > 30) (p = 0.04) as potential risk factors leading to the loss of tunnel central venous catheters. In contrast, there was a lower probability of central venous catheter loss due to Gram-positive pathogens (p = 0.01). The CLABSI rate was 1.55 per 100 patients per month over a five-year period. Patients with CVC required more hospital treatment and had a significantly higher rate of vascular access loss (p < 0.001). Both central and peripheral blood cultures had nearly identical microbe spectra. Methicillin-sensitive Staphylococcus aureus (MSSA), Methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus epidermidis had the highest prevalence rates among Gram-positive organisms. Among the Gram-negative bacteria, Enterobacter cloacae was the most common, followed by Klebsiella pneumonia and Pseudomonas aeruginosa. Conclusions: Our findings indicate the need for rigorous measures and interventions to prevent Gram-negative infections and decrease the reliance on central venous catheters, to decrease infections in hemodialysis patients, and decrease morbidity and cost. Strict hand hygiene, patient education, and surveillance programs are recommended to monitor these patients. Full article

Cracks are the initial manifestation of various diseases on highways. Preventive maintenance of cracks can delay the degree of pavement damage and effectively extend the service life of highways. However, existing crack detection methods have poor performance in identifying small cracks and are unable to calculate crack width, leading to unsatisfactory preventive maintenance results. This article proposes an integrated method for crack detection, segmentation, and width calculation based on digital image processing technology. Firstly, based on convolutional neural network, a optimized crack detection network called CFSSE is proposed by fusing the fast spatial pyramid pooling structure with the squeeze-and-excitation attention mechanism, with an average detection accuracy of 97.10%, average recall rate of 98.00%, and average detection precision at 0.5 threshold of 98.90%; it outperforms the YOLOv5-mobileone network and YOLOv5-s network. Secondly, based on the U-Net network, an optimized crack segmentation network called CBU_Net is proposed by using the CNN-block structure in the encoder module and a bicubic interpolation algorithm in the decoder module, with an average segmentation accuracy of 99.10%, average intersection over union of 88.62%, and average pixel accuracy of 93.56%; it outperforms the U_Net network, DeepLab v3+ network, and optimized DeepLab v3 network. Finally, a laser spot center positioning method based on information entropy combination is proposed to provide an accurate benchmark for crack width calculation based on parallel lasers, with an average error in crack width calculation of less than 2.56%. Full article