Analysis of fluid force and flow fields during gliding in swimming using smoothed particle hydrodynamics method.

Gliding is a crucial phase in swimming, yet the understanding of fluid force and flow fields during gliding remains incomplete. This study analyzes gliding through Computational Fluid Dynamics simulations. Specifically, a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method for flow-object interactions is established. Fluid motion is governed by continuity, Navier-Stokes, state, and displacement equations. Modified dynamic boundary particles are used to implement solid boundaries, and steady and uniform flows are generated with inflow and outflow conditions. The reliability of the SPH model is validated by replicating a documented laboratory experiment on a circular cylinder advancing steadily beneath a free surface. Reasonable agreement is observed between the numerical and experimental drag force and lift force. After the validation, the SPH model is employed to analyze the passive drag, vertical force, and pitching moment acting on a streamlined gliding 2D swimmer model as well as the surrounding velocity and vorticity fields, spanning gliding velocities from 1 m/s to 2.5 m/s, submergence depths from 0.2 m to 1 m, and attack angles from -10° to 10°. The results indicate that with the increasing gliding velocity, passive drag and pitching moment increase whereas vertical force decreases. The wake flow and free surface demonstrate signs of instability. Conversely, as the submergence depth increases, there is a decrease in passive drag and pitching moment, accompanied by an increase in vertical force. The undulation of the free surface and its interference in flow fields diminish. With the increase in the attack angle, passive drag and vertical force decrease whereas pitching moment increases, along with the alteration in wake direction and the increasing complexity of the free surface. These outcomes offer valuable insights into gliding dynamics, furnishing swimmers with a scientific basis for selecting appropriate submergence depth and attack angle.

Effects of tourism resource search on folk sports project development fuzzy front-end performance: The moderating role of environmental dynamics change.

How to improve the success of new project development through the collection of resources in the preliminary stages of new project development is a new area of research. Given the speed and magnitude of changes in the folk sports market environment, this study analyses the impact of tapping folk tourism resources on sports projects at the project development stage. Through stratified regression analyses of 600 Chinese firms engaged in folk sports project development, this paper finds that tapping internal tourism resources positively affects the Fuzzy Front-End Performance of incremental innovative project development. In contrast, tapping external tourism resources positively affects the Fuzzy Front-End Performance of breakthrough innovation projects. The study also indicates that the speed of environmental change (SEC) positively moderates the relationship between exploring external tourism resources (ERS) and Fuzzy Front-End Performance of incremental innovation projects. In contrast, the magnitude of environmental change (MEC) negatively moderated the relationship between internal tourism resource exploration (IRS) and the FFE-P of similar projects.

Research Progress on Chinese Traditional Archery: A Visualization Analysis Based on CiteSpace / Progreso de la investigación sobre el tiro con arco tradicional chino: un análisis de visualización basado en CiteSpace

With the intensification of global interactions, domestic scholars have progressively recognized the imperative to rejuvenate traditional Chinese archery, embarking on dedicated research endeavours. However, the multifaceted nature of archery, encompassing elements of sport, skill, and weaponry, introduces considerable uncertainties regarding its prospective developmental trajectories. Bibliometric analysis has emerged as a novel methodological approach and scholarly focal point for addressing these uncertainties. This study sought to employ a quantitative methodology to assess the corpus of Chinese traditional archery literature, employing CiteSpace for bibliometric analysis to construct a systematic knowledge map of Chinese traditional archery research. Through a comprehensive review of pertinent literature in the realm of traditional Chinese archery, the aim was to discern the future trajectory of research in this domain, with a view to safeguarding and perpetuating traditional archery within contemporary society while preserving China's cultural heritage. The findings revealed a pivotal emphasis on investigating the educational value of traditional archery in China. Furthermore, discernible research trends indicated a growing interest in elucidating the positive effects of traditional archery on physical health and mental well-being. Additionally, research forefronts included the preservation and advancement of traditional archery skills, the application of cutting-edge technology to augment athletes' competitive prowess, and the integration of traditional archery into interdisciplinary university curricula. Subsequent research endeavours should prioritize delving into the educational significance of traditional archery and harnessing advanced technology to enhance athletes' competitive capabilities.(AU)

Diagnostic Value of Multislice Spiral Computed Tomography Combined with Serum AFP, TSGF, and GP73 Assay in the Diagnosis of Primary Liver Cancer.

Objective: To explore the diagnostic value of multislice spiral computed tomography (MSCT) scan combined with serum alpha-fetoprotein (AFP), tumor-specific growth factor (TSGF), and Golgi protein73 (GP73) assays in the diagnosis of primary liver cancer (PLC). Methods: Totally, 60 patients with PLC admitted to The Second Hospital of Dalian Medical University from January 2019 to January 2020 were included in group A, 60 patients with liver cirrhosis were included in group B, and 60 healthy subjects were included in group C. The serum AFP, TSGF, and GP73 levels were determined, and all participants received MSCT scanning. The diagnostic efficacy of MSCT, assays of serum AFP, TSGF, and GP73, and their combined detection was analyzed. Results: Group A had the highest levels of AFP, TSGF, and GP73, followed by group B, and then group C. The sensitivity, specificity, positive predictive value, and negative predictive value of MSCT for PLC were 80.0%,91.7%, 82.8%, and 90.2%, respectively, while those of combined detection of MSCT plus serum AFP, TSGF, and GP73 for PLC were 100.0%, 93.3%, 88.2%, and 100.0%. The combined detection was associated with significantly a higher detection rate of PLC versus stand-alone detection. Conclusion: MSCT plus serum AFP, TSGF, and GP73 has a higher detection rate versus stand-alone detection, which shows great potential in the diagnosis of PLC.

Head trauma complicated with primary cranial vault lymphoma: A case report.

RATIONALE: Primary cranial vault lymphoma (PCVL) is an extremely rare extranodal lymphoma in the skull. This case study investigates the clinical features, so as to improve the understanding of the diagnosis and therapy. PATIENT CONCERNS: A 31-year-old male presented painful scalp mass at the site of 1-month-old head trauma. DIAGNOSIS: The final diagnosis was plasma cell lymphoma, which is a rare subtype of diffuse large B-cell lymphoma based on biopsy and immunohistochemistry findings. INTERVENTIONS: The patient received total tumor resection in combination with chemotherapy OUTCOMES:: The patient survived without signs of systemic dissemination for 12 months after surgery at the time of last follow-up. LESSONS: Trauma may be one of the factors that induce PCVL. The final diagnosis of PCVL depends on pathology and immunohistochemistry findings. A combined treatment of surgery, chemotherapy, and radiotherapy can achieve favorable outcomes.