Search Results (24,160)

The broad-spectrum insect growth regulator (IGR) and insecticide 2-((1-(4-Phenoxyphenoxy)propan-2-yl)oxy)pyridine (MPEP; also known as pyriproxyfen) is increasingly being used to address public health programs for vector control, initiated by the spread of Zika virus in 2015–2016. While considered relatively safe for humans under normal conditions, limited toxicology data are available. Current studies were undertaken to address the data gap regarding potential immunotoxicity of MPEP, with particular emphasis on host resistance to viral infection. Hsd:Harlan Sprague Dawley SD^® rats were treated for 28 days by oral gavage with doses of 0, 62.5, 125, 250 or 500 mg/kg/day of MPEP in corn oil. There was a dose-dependent increase in liver weights which is consistent with the liver playing a dominant role in MPEP metabolism. However, no histological correlates were observed. Following treatment, rats were subjected to a battery of immune tests as well as an established rat model of influenza virus infection to provide a comprehensive assessment of immune function and host resistance. While several of the immune tests showed minor exposure-related changes, evidenced by negative dose–response trends, most did not show significant differences in any of the MPEP treatment groups relative to vehicle control. Most notable was a negative trend in pulmonary mononuclear cell phagocytosis with increases in dose of MPEP. There was also a positive trend in early humoral immune response (5 days after immunization) to keyhole limpet hemocyanin (KLH) as evidenced by increased serum anti-KLH IgM antibodies which was followed later (14 days following immunization) by decreasing trends in anti-KLH IgM and IgG antibody levels. However, MPEP treatment had no effect on the ability of rats to clear the influenza virus nor the T-dependent IgM and IgG antibody response to the virus. The lack of effects of MPEP on host resistance to influenza suggests the immune effects were minimal and unlikely to present a hazard with respect to susceptibility to respiratory viral infection. Full article

Quality assurance programs are critical to ensuring the consistency and reliability of point-of-care surveillance test results. In 2022, we launched Laos’ inaugural quality control (QC) and external quality assessment (EQA) program for national HIV recent infection surveillance. Our study aims to implement the first QC and EQA program for national HIV recent infection surveillance in Laos, utilizing non-infectious dried tube specimens (DTS) for quality control testing. This initiative seeks to monitor and assure the quality of HIV infection surveillance. We employed the Asante HIV-1 Rapid Test for Recent Infection (HIV-1 RTRI) point-of-care kit, using plasma specimens from the Thai Red Cross Society to create dried tube specimens (DTS). The DTS panels, including HIV-1 negative, HIV-1 recent, and HIV-1 long-term samples, met ISO 13528:2022 standards to ensure homogeneity and stability. These panels were transported from the Thai National Institute of Health (Thai NIH) to the Laos National Center for Laboratory and Epidemiology (NCLE) and subsequently shipped to 12 remote laboratories at ambient temperature. The laboratory results were electronically transmitted to Thai NIH 15 days after receiving the panel for performance analysis. The concordance results with the sample types were scored, and laboratories that achieved 100% concordance across all sample panels were considered to have satisfactorily met the established standards. Almost all laboratories demonstrated satisfactory results with 100% concordance across all sample panels during all three rounds of QC: 11 out of 12 (92%) in June, 10 out of 12 (83%) in July, and 11 out of 12 (91%) in August. The two rounds of EQA performed in June and August 2022 were satisfied by 8 out of 11 (72%) and 5 out of 10 (50%) laboratories, respectively. QC and EQA monitoring identified errors such as testing protocol mistakes and insufficient DTS panel dissolution, leading to improvements in HIV recency testing quality. Laboratories that reported errors were corrected and implemented further preventive actions. The QC and EQA program for HIV-1 RTRI identified errors in HIV recent infection testing. Implementing a specialized QC and EQA program for DTS marks a significant advancement in improving the accuracy and consistency of HIV recent infection surveillance. Continuous assessment is vital for addressing recurring issues. Full article

The development of slicing equipment for Fritillariae Thunbergii Bulbus (FTB) has been constrained by the absence of precise and reliable simulation model parameters, which has hindered the optimization of structural design through simulation techniques. Taking FTB as the research object, this study aims to resolve this issue by conducting the calibration and experimental validation of the discrete element parameters for FTB. Both intrinsic and contact parameters were obtained through physical experiments, on the basis of which a discrete element model for FTB was established by using the Hertz–Mindlin with bonding model. To validate the calibrated bonding parameters of this model, the maximum shear force was selected as the evaluation index. Significant influencing factors were identified and analyzed through a single-factor test, a two-level factorial test, and the steepest ascent method. Response surface methodology was then applied for experimental design and parameter optimization. Finally, shear and compression tests were conducted to verify the accuracy of calibrated parameters. The results show that the mechanical properties of FTB are significantly affected by the normal stiffness per unit area, the tangential stiffness per unit area, and the bonding radius, with optimal values of 1.438 × 10⁸ N·m⁻³, 0.447 × 10⁸ N·m⁻³, and 1.362 mm, respectively. The relative errors in the shear and compression tests were all within 5.18%. The maximum error between the simulated and measured maximum shear force under three different types of blades was less than 5.11%. The percentages of the average shear force of the oblique blade were reduced by 52.23% and 29.55% compared with the flat and arc blades, respectively, while the force variation trends for FTB remained consistent. These findings confirm the reliability of the simulation parameters and establish a theoretical basis for optimizing the structural design of slicing equipment for FTB. Full article

In response to the challenges associated with weld treatment during the on-site corrosion protection of hydraulic steel gates, this paper proposes a method utilizing a magnetic adsorption climbing robot to perform corrosion protection operations. Firstly, a magnetic adsorption climbing robot with a multi-wheel independent drive configuration is proposed as a mobile platform. The robot body consists of six joint modules, with the two middle joints featuring adjustable suspension. The joints are connected in series via an EtherCAT bus communication system. Secondly, the kinematic model of the climbing robot is analyzed and a PID trajectory tracking control method is designed, based on the kinematic model and trajectory deviation information collected by the vision system. Subsequently, the proposed kinematic model and trajectory tracking control method are validated through Python3 simulation and actual operation tests on a curved trajectory, demonstrating the rationality of the designed PID controller and control parameters. Finally, an intelligent software system for weld defect detection based on computer vision is developed. This system is demonstrated to conduct defect detection on images of the current weld position using a trained model. Full article

Background: Handheld dynamometry (HHD) is widely utilized for assessing muscle strength, particularly in the wrist. However, variability in measurement reliability due to differences in testing protocols poses a challenge for clinical and research applications. Methods: The design of this study includes a scoping review of the literature, conducted following the PRISMA-ScR checklist methodology developed by the Joanna Briggs Institute. The databases most commonly cited in review articles were consulted: EBSCO, PEDro, PubMed, Scopus, and Cochrane Library. The following MeSH terms were used: “Handheld Dynamometer”, “Wrist”, “Forearm”, “Muscle”, and “Strength”. The search strings were built using combinations of these terms. Article screening was performed by three reviewers independently, blinded to each other’s selections. Results: The review indicates that HHD can provide reliable measurements when standardized protocols are used. Most studies reported high intra-examiner reliability with Intraclass Correlation Coefficients (ICCs) between 0.71 and 0.90. However, inter-examiner reliability showed more variability, particularly when more than two examiners were involved. The review also highlights the importance of precise dynamometer placement and consistent patient positioning in order to reduce measurement variability. Conclusions: While HHD is a valuable tool for wrist strength assessment, the effectiveness of its measurements largely depends on the testing procedure’s standardization. Implementing validated standardized protocols is essential in enhancing measurement reliability and ensuring their consistent application across clinical settings. Further research is needed to firmly implement these protocols and expand their application in clinical practice. Full article

With the gradual development of digital twin technology from theory to practice, the importance of the efficient reuse of existing digital twin models has become increasingly prominent in order to reduce the waste of resources and additional costs caused by repeated modeling. To address the difficulty of reusing multi-dimensional model information (MMI) in existing digital twin models during the conversion process from geometric models to digital twin models, this paper proposes a method for reusing MMI in discrete workshops. First, MMI and its representations are defined and constructed. Subsequently, a model-matching approach is introduced to identify appropriate MMIs for geometric models. Following this, a reuse strategy for workshop MMIs is thoroughly explained. Finally, the effectiveness of the proposed method is validated through case studies in the arc-welding workshop. The accuracy of single-model matching remains consistently at 1 across all model tests, and the proposed method reduces the total number of operations by 126 (94.7%) compared to existing methods in multi-device model construction. The results show that this method can effectively organize the workshop digital twin model, compensate for the shortage of digital twin model reuse, and help engineers reuse the existing MMI to build a digital twin model. Full article

This study investigates the mechanical properties of ABS parts fabricated via used deposition modeling (FDM) through integrated experimental and numerical approaches. ABS resin was used as the experimental material, and tensile tests were conducted using a universal testing machine. Finite element analysis (FEA) was performed via ANSYS 2021 to simulate stress deformation behavior, with key parameters including a gauge length of 10 mm (pre-stretching) and printing temperature gradients. The results show that the specimen exhibited a maximum tensile force of 7.3 kN, upper yield force of 3.7 kN, and lower yield force of 3.2 kN, demonstrating high strength and toughness. The non-proportional elongation reached 0.06 (6%), and the quantified enhancement multiple of AM relative to traditional manufacturing was 1.1, falling within the reasonable range for glass fiber-reinforced or specially formulated ABS. FEA results validated the experimental data, showing that the material underwent 15 mm of plastic deformation before fracture, consistent with ABS’s ductile characteristics. Full article

Objectives: The aim of this study was to indicate which variables are the most important determinants of swimming results in the 50 m front crawl among non-elite pre-pubertal female swimmers. Methods: The study group consisted of 14 female swimmers (at the time of the research commencement—biological age: 10.52 ± 0.37 years; body mass: 34.99 ± 2.77 kg; height: 146.00 ± 3.05 cm). The study was conducted over three years. The swimmers performed capacity training recommended by the British Swimming Federation. Every 6 months, in the participants the following parameters were measured: percentage of body fat; anthropometric measurements; aerobic and anaerobic capacity; and respiratory parameters: vital capacity—VC, forced expiratory volume—FEV1, and forced vital capacity—FVC. Additionally, a 50 m front crawl swim test was performed. Results: After adjusting for multicollinearity, the most influential determinants of swimming performance were anthropometric measures: shoulder width was the most influential predictor, with a regression coefficient of −0.66, followed by foot length (with a beta of −0.15) and chest depth (with a beta of 0.008). The remaining anthropometric and physical predictors did not contribute to the prediction of 50 m freestyle performance. Conclusions: These research results suggest to coaches and trainers that sports performance in sprint distances in pre-pubertal girls is not determined by aerobic and anaerobic capacity or body fat but is based on the somatic build of the swimmer. Full article

The Iridaceae family comprises approximately 1800 species, including Iris pallida Lam., which is widely recognized for its ornamental and aromatic properties and particularly adopted in the perfume industry. In this study, we evaluated the effects of planting density and maturity age on biomass production, morphological traits, rhizome biomass, and orris concrete yield in Iris pallida grown in Tuscany (Italy). The experiment consisted of four agricultural parcels, each one containing six plots arranged to test combinations of two planting densities (low density [LD], 8 plants/m² and high density [HD], 15 plants/m²) and harvesting age (2, 3, and 4 years). Results indicated that planting density significantly influenced biomass variables—including rhizome, bud, and stem biomass—with the low planting density (LD) exhibiting higher total biomass (5.48 ± 0.59 kg/m²) compared to that observed under high planting density (HD) (1.82 ± 0.54 kg/m²). Orris concrete yield varied significantly across planting densities and harvesting age, consistently favoring LD (0.055 ± 0.01%) over HD (0.045 ± 0.01%). Also, orris concrete yield showed a positive correlation with floral stem number (r = 0.73, p < 0.001), root biomass (r = 0.66, p < 0.01) and floral stem biomass (r = 0.63, p < 0.01), while no significant correlations were found between orris concrete yield and total biomass or rhizome biomass. A shorter production cycle under low-density planting may improve orris concrete yield without compromising biomass productivity. Full article

In this study, a new fibre combination for an interlayer hybrid fibre-reinforced polymer laminate was investigated to achieve pseudo-ductile behaviour in tensile tests. The chosen high-strain fibre for this purpose was S-Glass, and the low-strain fibre was flax. These materials were chosen because of their relatively low environmental impact compared to carbon/carbon and carbon/glass hybrids. An analytical model was used to find an ideal combination of the two materials. With that model, the expected stress–strain relation could also be predicted analytically. The modelling was based on preliminary tensile tests of the two basic components investigated in this research: unidirectional laminates reinforced with either flax fibres or S-Glass fibres. Hybrid specimens were then designed, produced in a heat-assisted pressing process, and subjected to tensile tests. The strain measurement was performed using distributed fibre optic sensing. Ultimately, it was possible to obtain repeatable pseudo-ductile stress–strain behaviour with the chosen hybrid when the specimens were subjected to quasi-static uniaxial tension in the direction of the fibres. The intended damage-mode, consisting of a controlled delamination at the flax-fibre/glass-fibre interface after the flax fibres failed, followed by a load transfer to the glass fibre layers, was successfully achieved. The pseudo-ductile strain averaged 0.52% with a standard deviation of 0.09%, and the average load reserve after delamination was 145.5 MPa with a standard deviation of 48.5 MPa. The integrated fibre optic sensors allowed us to monitor and verify the damage process with increasing strain and load. Finally, the analytical model was compared to the measurements and was partially modified by neglecting the Weibull strength distribution of the high-strain material. Full article

Background: Women with systemic autoimmune rheumatic disease (SARD) are at higher risk of developing infection-related complications, anxiety, and depression. Using the example of the COVID-19 pandemic, we aimed to explore the impact of this external stressor on symptoms of depression, anxiety, and stress in a sample of women with SARD in a cross-sectional study design. Methods: Females aged 18–50 with SARD were enrolled from 04/2021 to 04/2022 at the Medical University of Vienna or through an online self-help group, while snowball sampling was used to recruit an age-matched healthy control group. Participants completed questionnaires including: (1) demographic information, medical history, and access to healthcare; (2) the Depression, Anxiety, and Stress Scale (DASS-21); and (3) the Coronavirus Anxiety Scale (CAS). Parameters were compared between groups using Chi-squared, Fisher’s exact, and Mann–Whitney U tests. Linear regression analysis was used to investigate which individual factors predicted the DASS-21 in women with SARD. Results: The study sample consisted of 226 women (n = 99 with SARD and n = 127 healthy controls). Women with SARD reported lower DASS-21 stress (p = 0.008) and CAS scores (p = 0.057) than the control group. There were no significant differences in DASS-21 anxiety or depression scores. Among women with SARD, a linear regression model identified the most important predictors of DASS-21 as access to rheumatological care (p = 0.002) and recent disease activity (p = 0.028). Conclusions: Despite the pandemic, women with SARD reported mental health outcomes equal to or better than those of the healthy control group. Continued access to rheumatological care may serve as an important protective factor for their mental health during large-scale crises like pandemics. Full article

This paper explores the role of one-part alkali-activated cement, utilizing metakaolin as a precursor, in the long-term stabilization of mining tailings. Investigating three key factors (Si/Al and Na/Si ratios and curing period), this study reveals insights into the mechanical performance and microstructure of alkali-activated cemented iron ore tailings. Unconfined compressive strength test, statistical analysis, and Scanning Electron Microscopy analysis with Energy Dispersive Spectroscopy were performed. Findings indicate that the Si/Al ratio significantly influences strength, with an optimal ratio of 3.5. The Na/Si ratio introduces complexity, affecting alkali availability and reactivity, leading to nuanced strength variations. Extended curing periods consistently enhance the strength of alkali-activated cement, highlighting its dynamic nature. Notably, the 7-day specimens exhibit a less homogeneous distribution, weaker bonding, and decreased structural integrity compared to their 60-day counterparts. This research underscores the intricate nature of alkali-activated cement hydration, emphasizing the interdependence of Si/Al and Na/Si ratios. The observed strengthening effect with prolonged curing suggests the potential for tailoring these materials to specific applications. Addressing a research gap, especially in applying alkali-activation to mining tailings stabilization, this study highlights metakaolin’s role as a suitable precursor. Full article

This study examines the complex interactions among soil moisture, evaporation, extreme weather events, and lightning, and their influence on fire activity across the extratropical and Pan-Arctic regions. Leveraging reanalysis and remote-sensing datasets from 2000 to 2020, we applied cross-correlation analysis, a modified Mann–Kendall trend test, and assessments of interannual variability to key variables including soil moisture, fire frequency and risk, evaporation, and lightning. Results indicate a significant increase in dry days (up to 40%) and heatwave events across Central Eurasia and Siberia (up to 50%) and Alaska (25%), when compared to the 1980–2000 baseline. Upward trends have been detected in evaporation across most of North America, consistent with soil moisture trends, while much of Eurasia exhibits declining soil moisture. Fire danger shows a strong positive correlation with evaporation north of 60° N (r ≈ 0.7, p ≤ 0.005), but a negative correlation in regions south of this latitude. These findings suggest that in mid-latitude ecosystems, fire activity is not solely driven by water stress or atmospheric dryness, highlighting the importance of region-specific surface–atmosphere interactions in shaping fire regimes. In North America, most fires occur in temperate grasslands, savannas, and shrublands (47%), whereas in Eurasia, approximately 55% of fires are concentrated in forests/taiga and temperate open biomes. The analysis also highlights that lightning-related fires are more prevalent in Eastern Europe and Southeastern Asia. In contrast, Western North America exhibits high fire incidence in temperate conifer forests despite relatively low lightning activity, indicating a dominant role of anthropogenic ignition. These findings underscore the importance of understanding land–atmosphere interactions in assessing fire risk. Integrating surface conditions, climate extremes, and ignition sources into fire prediction models is crucial for developing more effective wildfire prevention and management strategies. Full article

To solve the issue that existing yield prediction methods do not fully capture the interaction between multiple factors, we propose a winter wheat yield prediction framework with triple cross-attention for multi-source data fusion. This framework consists of three modules: a multi-source data processing module, a multi-source feature fusion module, and a yield prediction module. The multi-source data processing module collects satellite, climate, and soil data based on the winter wheat planting range, and constructs a multi-source feature sequence set by combining statistical data. The multi-source feature fusion module first extracts deeper-level feature information based on the characteristics of different data, and then performs multi-source feature fusion through a triple cross-attention fusion mechanism. The encoder part in the production prediction module adds a graph attention mechanism, forming a dual branch with the original multi-head self-attention mechanism to ensure the capture of global dependencies while enhancing the preservation of local feature information. The decoder section generates the final predicted output. The results show that: (1) Using 2021 and 2022 as test sets, the mean absolute error of our method is 385.99 kg/hm², and the root mean squared error is 501.94 kg/hm², which is lower than other methods. (2) It can be concluded that the jointing-heading stage (March to April) is the most crucial period affecting winter wheat production. (3) It is evident that our model has the ability to predict the final winter wheat yield nearly a month in advance. Full article

The dynamic non-equilibrium effect (DNE) describes the non-unique character of saturation–capillary pressure relationships observed under static, steady-state, or monotonic hydrodynamic conditions. Macroscopically, the DNE manifests as variations in soil hydraulic characteristic curves arising from varying hydrodynamic testing conditions and is fundamentally governed by soil matrix particle size distribution. Changes in the DNE across porous media with discrete particle size fractions are investigated via stepwise drying experiments. Through quantification of saturation–capillary pressure hysteresis and DNE metrics, three critical signatures are identified: (1) the temporal lag between peak capillary pressure and minimum water saturation; (2) the pressure gap between transient and equilibrium states; and (3) residual water saturation. In the four experimental sets, with the finest material (Test 1), the peak capillary pressure consistently precedes the minimum water saturation by up to 60 s. Conversely, with the coarsest material (Test 4), peak capillary pressure does not consistently precede minimum saturation, with a maximum lag of only 30 s. The pressure gap between transient and equilibrium states reached 14.04 cm H₂O in the finest sand, compared to only 2.65 cm H₂O in the coarsest sand. Simultaneously, residual water saturation was significantly higher in the finest sand (0.364) than in the coarsest sand (0.086). The results further reveal that the intensity of the DNE scales inversely with particle size and linearly with wetting phase saturation (Sw), exhibiting systematic decay as Sw decreases. Coarse media exhibit negligible hysteresis due to suppressed capillary retention; this is in stark contrast with fine sands, in which the DNE is observed to persist in advanced drying stages. These results establish pore geometry and capillary dominance as fundamental factors controlling non-equilibrium fluid dynamics, providing a mechanistic framework for the refinement of multi-phase flow models in heterogeneous porous systems. Full article