Search Results (241)

As the primary collision patterns on China’s freeways, in-depth exploration of the influencing factors of rear-end and sideswipe crashes has long been crucial for implementing targeted countermeasures. However, the structural and traffic flow continuity of freeways endows crash data with complex spatial and site correlations, which—if neglected in safety modeling—can lead to biased estimates of safety effects. To address this issue, this study develops a bivariate conditional autoregressive (CAR) model based on the Poisson lognormal (PLN) distribution: the copula joint distribution captures the site correlation between the two crash types, while the CAR model addresses spatial correlations across adjacent segments. Compared with univariate models and bivariate models with jointly distributed residuals, the proposed model achieves optimal performance and reveals the distinct determinants of the two crash types. For instance, factors such as spiral curve length and mean speed affect both crash types but to varying degrees, while continuous horizontal curve length only influences rear-end crashes. The proposed model and the identified influencing factors provide significant support for engineers to improve road safety. Full article

Grand-design spiral structures typically emerge in N-body simulations of disk galaxies as barred-spiral configurations forming during the early evolutionary stages of the system. In this study, we explore the dynamical conditions that allow for the formation and sustained presence of a non-barred, bisymmetric grand-design spiral pattern in fully self-consistent N-body models over considerable time periods. We present a model in which such non-barred morphologies persist for approximately 2.5 Gyr. The simulation is carried out using a standard implementation of the GADGET-3 code, incorporating both stellar and gaseous components in the disk and embedding them within a live dark matter halo. A characteristic feature of the simulation is that during its normal spiral grand-design phase the disk remains submaximal. Star formation is active throughout the model’s evolution. Analysis of the resulting morphology indicates that dominant inner, symmetric spiral arms extend between the inner Lindblad resonance (ILR) and the radial inner 4:1 resonance. This structure is evident in both the stellar and gaseous components, exhibiting extensions and bifurcations consistent with predictions from orbital theory. Full article

Pumped-storage power plants play a vital role in power systems by providing peak load regulation, frequency control, and phase modulation services. The safety and stability of these plants critically depend on understanding transient processes during frequent unit start–stop cycles and operational transitions. This study employs 1D–3D coupled numerical simulations to investigate a pump–turbine unit’s external characteristics, pressure pulsations, and internal flow dynamics under turbine runaway conditions. At the runaway rotational speed of 650.9 r/min, large-scale vortices with intensities exceeding 500 s⁻¹ form at the inlet of specific runner blade passages, severely obstructing flow. Concurrently, the tailwater pipe vortex structure transitions from a central spiral pattern to a wall-attached configuration. The concurrent occurrence of these phenomena induces abrupt runner force variations and significant pressure pulsations, primarily comprising high-frequency high-amplitude pulsations at 1× and 2× blade frequency attributable to runner dynamic-static interference; broad-spectrum high-amplitude pulsations resulting from operational transitions; and low-frequency high-amplitude pulsations induced by the tailwater pipe vortex belt. Full article

Background: The inner ear hosts several macrophage populations. Endolymphatic sac macrophages can phagocytose otoconia, and spiral limbus macrophages express genes for fluid shear stress sensing and bone remodeling. Obstruction of endolymph flow by saccular otoconia could be linked to endolymphatic hydrops. Since macrophages are strongly affected by inflammatory status, a role for them in otolith removal could provide a link between inflammation and hydrops. However, the distribution of macrophages around the reuniting duct (RD) and endolymphatic duct (ED), which are narrow structures likely prone to blockage, remains unexplored. Methods: We performed tissue clearing and light-sheet imaging on rat temporal bones. Autofluorescence and immunolabeling for collagen IV, smooth muscle actin, and Iba1 were used to visualize inner ear structures, blood vessels, and macrophages. Results: The connective tissue layer underlying the RD extended from the cochlear spiral limbus. The RD and spiral limbus hosted a continuous microvascular network and macrophage population, comprising both ameboid and ramified cells; macrophages also surrounded the underlying vestibulocochlear artery (VCA). A separate macrophage population, continuous with that of the saccular connective tissue, was found around the endolymphatic sinus and utriculo–endolymphatic (Bast’s) valve; macrophage patterns changed in the vestibular aqueduct and endolymphatic sac. Conclusions: Macrophages are observed in positions consistent with potential roles in sensing luminal changes and in the clearance of obstructive material from the RD and ED; functional confirmation will require targeted experiments. Full article

Binge drinking is defined as consuming a large amount of alcohol in a short period of time, whereas hangover is a cluster of unpleasant mental symptoms and physical signs that typically manifest the next day after binge drinking. Binge drinking is a prevalent pattern of alcohol consumption, especially in adolescents, with dualistic effects on social behavior. While some studies demonstrate that a single episode of binge drinking enhances sociability and preference for social novelty, other studies indicate that repeating cycles of binge drinking and hangover can lead to persistent negative affect and consequently social withdawal. This is an integrative narrative review synthesizing human studies and animal models of binge drinking (also known as alcohol intoxication) and hangover (also known as alcohol withdrawal). The major databases consulted were PubMed, Scopus, and Web of Science. The search terms used were “binge drinking” or “hangover”and “social behavior” or “social brain” in combination with “rats”, “mice” or “humans”. Finding the missing link between structural and functional changes in the social brain in the context of binge drinking and hangover is crucial for developing novel therapeutic strategies for alcohol intoxication and withdrawal. This review focuses on changes in hypothalamic neurohormones and extrahypothalamic neurotransmitters in these states, and concludes with the statement that targeting neuropeptides such as corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) and their receptors, which are involved in both binge drinking and social behavior, may prevent repeated cycles of binge drinking and hangover from spiraling into alcohol addiction and, ultimately, social isolation. Full article

Secondhand smoke (SHS), found in about 57.6% of global public areas as a widespread environmental hazard, has been associated with negative effects during pregnancy, such as preeclampsia (PE) and intrauterine growth restriction (IUGR). Our research investigated the impact of SHS on placental issues in a C57BL/6 model that simulates PE and IUGR in mice. We administered SHS to pregnant mice through a nose-only delivery method, beginning either on embryonic day 12.5 (prior to spiral artery (SA) invasion; labeled SHS-6D) or day 14.5 (following SA invasion; labeled SHS-4D), continuing up to E18.5. Control animals received only ambient air. We employed bulk RNA sequencing to assess and describe changes in placental gene expression patterns. For the SHS-4D group, which mimicked IUGR, compared to untreated controls, results showed elevated levels of inflammation-related genes (IL11RA, CHI3L1) alongside likely interference in pathways for antibody-triggered complement activation, marked by reduced expression of C1QA, C1QB, and C1QC. Immune profiling also indicated decreased macrophage activity in the placentas of the SHS-4D group relative to those from normal pregnancies at term. In contrast, the SHS-6D versus control analysis revealed lowered expression of collagen-related genes (COL1A1, COL4A5, COL4A6, COL17A1). Additionally, SHS-6D exhibited higher levels of genes associated with cell-based lysis processes compared to SHS-4D. An evaluation of the existing literature revealed that nearly every differentially expressed gene (DEG) identified in our work has been reported in studies associated with SHS exposure. Yet, few of these DEGs are discussed alongside PE or IUGR in prior reports, highlighting gaps in knowledge about how SHS triggers these conditions. Overall, we determined that the timing of SHS exposure in pregnant mice results in unique patterns of gene regulation and involvement in biological pathways. Full article

Background: Early detection of Parkinson’s disease (PD) is vital for improving patient outcomes, yet traditional diagnostic methods often depend on subjective clinical evaluations. Methods: This study proposes a novel deep learning framework for PD detection based on spiral and wave handwriting patterns from the PaHaW dataset. A comprehensive preprocessing pipeline is implemented, integrating histogram equalization and Canny edge detection. The processed spiral and wave images are evaluated independently using a fine-tuned EfficientNetV2-S architecture for binary classification. In addition to the EfficientNetV2-S experiments, a baseline Convolutional Neural Network (CNN) model is implemented separately for the spiral and wave handwriting images. The proposed model is further assessed using a 5-fold cross-validation strategy to ensure robustness and generalizability. Results: The models achieved validation accuracies of 98.68% on the spiral dataset and 98.10% on the wave dataset, with high Receiver Operating Characteristic–Area Under the Curve (ROC–AUC) scores, indicating robust discrimination between healthy and PD subjects. Analysis of the confusion matrix and classification results confirmed consistent sensitivity and specificity across the dataset. The 5-fold cross-validation yielded a standard deviation of ±0.0109. Conclusions: These results highlight the strong potential of handwriting analysis for early PD detection. Full article

The European part of Russia has been characterized by a remarkably low documented diversity of entomopathogenic fungi, particularly when compared to the high species richness recorded in the Russian Far East. This pattern has persisted through decades of primarily morphology-based studies, which require critical reassessment using modern molecular methods. Here, we introduce a new species, Cordyceps biarmica, described from its asexual stage collected in the taiga of Arkhangelsk Oblast, representing a notable addition to the known diversity of the genus Cordyceps in the region. The fungus was isolated from a poorly preserved lepidopteran cocoon with pulvinate, unbranched conidiomata. Morphological features of its pure culture revealed an Isaria-like asexual morph characterized by solitary or verticillate phialides on a subspherical to subcylindrical base, bearing conidia in imbricate chains twisted in spirals. Multilocus phylogenetic analysis of a five-locus dataset (ITS, nrLSU, rpb1, rpb2, and tef1-α) was conducted using Maximum Likelihood and Bayesian Inference. The isolate was robustly placed within Cordyceps s.s., forming a distinct monophyletic lineage separate from other closely related well-supported taxa, including Cordyceps cateniannulata, C. exasperata, C. locastrae, C. polyarthra, C. sandindaengensis, and C. spegazzinii. Full article

This study presents the design, modeling, and multi-platform simulation of NEPTUNE-R, a solar-powered autonomous hydro-robot developed for sustainable water purification and oxygenation. Mechanical design was performed in Fusion 360, trajectory optimization in MATLAB R2024a, and dynamic motion analysis in Roblox Studio, creating a reproducible digital twin environment. The proposed path-planning strategies—Boustrophedon and Archimedean spiral—achieved full surface coverage across various lake geometries, with an average efficiency of 97.4% ± 1.2% and a 12% reduction in energy consumption compared to conventional linear patterns. The integrated Euler-based force model ensured stability and maneuverability under ideal hydrodynamic conditions. The modular architecture of NEPTUNE-R enables scalable implementation of photovoltaic panels and microbubble-based oxygenation systems. The results confirm the feasibility of an accessible, zero-emission platform for aquatic ecosystem restoration and contribute directly to Sustainable Development Goals (SDGs) 6, 7, and 14 by promoting clean water, renewable energy, and life below water. Future work will involve prototype testing and experimental calibration to validate the numerical findings under real environmental conditions. Full article

The design of tubular flocculators has advanced in the pursuit of more efficient and compact water treatment systems. Helically coiled tube flocculators (HCTFs) are known for generating stable secondary flows and uniform hydrodynamic patterns after the development length. However, their constant geometry restricts the hydrodynamic variability required for optimized flocculation. This study introduces the spirally coiled tube flocculator (SCTF), characterized by a winding diameter that varies along its length. CFD simulations and laboratory-scale experiments compared HCTFs and SCTFs in terms of turbidity removal capacity, axial velocity profiles, secondary flows, streamlines, and global velocity gradients. The SCTF outperformed the HCTFs under all evaluated configurations, achieving up to 98.2% turbidity removal. The results emphasize the potential of spiral geometries to enhance process efficiency and highlight the need to reconsider hydrodynamic strategies in the design of tubular flocculators. Full article

Spiral finned tube heat exchangers are extensively used in petrochemical, power electronics, and metallurgical industries due to their high efficiency and compact design. However, fouling accumulation during operation significantly reduces heat transfer efficiency and increases pressure loss. This study develops a hybrid approach integrating discrete element method (DEM), finite element analysis (FEA), and HTRI Xchanger Suite 7 software to correlate fouling thickness with thermal performance and establish a prediction model for tube-side outlet temperature under varying conditions. DEM simulations analyze dust deposition patterns and determine equivalent fouling thickness distribution. A fouling-integrated FE model then evaluates how fouling thickness affects both heat transfer and flow resistance coefficients. Through orthogonal experimental design considering fouling thickness, ambient temperature, and inlet air velocity, thermal resistance values calculated from FEA are imported into HTRI to predict outlet temperature. A random forest algorithm is subsequently employed to develop a multivariable prediction model. Validation conducted on a spiral finned tube heat exchanger at Chongqing Xiangguosi Underground Gas Storage Co., Ltd. (Chongqing, China) confirmed close agreement between simulated and actual fouling patterns. The maximum relative error of the predicted outlet temperatures on the testing dataset was 0.1869%, demonstrating the proposed method’s potential to support performance evaluation and operational optimization of fouled heat exchangers. Full article

In many monitoring scenarios, repeated and operator-independent assessments are needed. Wearable ultrasound technology has the potential to continuously provide the vital information traditionally obtained from conventional ultrasound scanners, such as in fetal monitoring for high-risk pregnancies. This work is an engineering study motivated by that setting. A 144-element annular capacitive micromachined ultrasonic transducer (CMUT) is hereby proposed for 3-D ultrasound imaging. The array is characterized by its compact size and cost-effectiveness, with a geometry and low-voltage operation that make it a candidate for future wearable integration. To enhance the imaging performance, we propose the utilization of a Fermat’s spiral virtual source (VS) pattern for diverging wave transmission and conduct a performance comparison with other VS patterns and standard techniques, such as focused and plane waves. To facilitate this analysis, a simplified and versatile simulation framework, enhanced by GPU acceleration, has been developed. The validation of the simulation framework aligned closely with expected values (0.002 ≤ MAE ≤ 0.089). VSs following a Fermat’s spiral led to a balanced outcome across metrics, outperforming focused wave transmissions for this specific aperture. The proposed transducer presents imaging limitations that could be improved in future developments, but it establishes a foundational framework for the design and fabrication of cost-effective, compact 2-D transducers suitable for 3-D ultrasound imaging, with potential for future integration into wearable devices. Full article

Helicobacter pylori is a spiral microorganism capable of inducing a range of gastric diseases. Among different virulence determinants produced by this bacterium, VacA and CagA are of critical importance for the development of these conditions. Taking into account the ability to chronically colonize the stomach, drug-resistant strains of this pathogen can be repeatedly exposed to subinhibitory antibiotic concentrations, which in turn may reduce or enhance their extracellular vesicles (EVs)-derived virulence towards gastric cells. With the use of different experimental techniques, we were the first to demonstrate that subinhibitory antibiotic concentrations modify both the cytotoxicity and cytopathic effect induced by EVs of H. pylori in gastric cells. The ability to induce vacuolization and the hummingbird phenotype in gastric cells presented an antibiotic-specific pattern. At the highest doses tested, all EV types induced phenotypic changes and cytotoxicity in gastric cells; however, the highest lethal effect was observed for EVs isolated from native (antibiotic-unexposed) cells. This suggests that short-term exposure of H. pylori to subinhibitory antibiotic concentrations does not translate into exacerbation of its EVs-dependent virulence. Nevertheless, extensive research in this area is undoubtedly needed to confirm these observations. Full article

Polar patterns and topological defects are ubiquitous in active matter. In this paper, we study a paradigmatic polar active dumbbell system through numerical simulations, to clarify how polar patterns and defects emerge and shape evolution. We focus on the interplay between these patterns and morphology, domain growth, irreversibility, and compressibility, tuned by dumbbell rigidity and interaction strength. Our results show that, when separated through MIPS, dumbbells with softer interactions can slide one relative to each other and compress more easily, producing blurred hexatic patterns, polarization patterns extended across entire hexatically varied domains, and stronger compression effects. Analysis of isolated domains reveals the consistent presence of inward-pointing topological defects that drive cluster compression and generate non-trivial density profiles, whose magnitude and extension are ruled by the rigidity of the pairwise potential. Investigation of entropy production reveals instead that clusters hosting an aster/spiral defect are characterized by a flat/increasing entropy profile mirroring the underlying polarization structure, thus suggesting an alternative avenue to distinguish topological defects on thermodynamical grounds. Overall, our study highlights how interaction strength and defect–compression interplay affect cluster evolution in particle-based active models, and also provides connections with recent studies of continuum polar active field models. Full article

Background: Identifying factors that predispose futsal athletes to anterior cruciate ligament (ACL) injuries is crucial for developing effective prevention strategies. This study aimed to determine whether specific dermatoglyphic markers are associated with an increased risk of ACL injury in this population. Methods: This retrospective case–control study analyzed 212 former male futsal athletes, divided into an injury group (n = 85 with a history of ACL injury) and a control group (n = 127 without injury). Fingerprint patterns (arches, loops, and whorls) and quantitative line counts were collected and analyzed using the dermatoglyphics method. Chi-square tests and log-linear regression were used for statistical analysis. Results: While no significant differences were found in the quantitative line counts between groups (p > 0.05), a significant association was identified for specific fingerprint patterns. The spiral whorl (WS) pattern on the left index finger (p = 0.043) and the right little finger (p = 0.007) was significantly more frequent in the ACL injury group. Overall, athletes presenting the WS pattern had approximately twice the odds of having a history of ACL injury (OR = 2.028, 95% CI 1.493–2.756). Conclusions: The findings suggest that specific dermatoglyphic patterns, particularly the spiral whorl, may serve as an indicator of a potential biological predisposition to ACL injuries in futsal athletes. This finding suggests dermatoglyphics could be a potential component for future multifactorial risk assessment models in futsal. Full article