Modern Health Science

Four Kinds of Forces Exerted on the Utricle

Hiroaki Ichijo, Hisako Ichijo — Sat, 31 May 2025 00:00:00 +0800

Objective:

The utricle is commonly understood to detect gravity and horizontal linear acceleration. We hypothesized that it may also respond to vertical linear acceleration, horizontal angular acceleration, and centrifugal force.

Methods:

We performed six physical analogy experiments using deformable media, spring-mounted masses, and human squatting tasks (five healthy humans). Observations included deformation patterns and eye movement recordings.

Results:

(1) Submerged lead deformed the pudding, modeling gravitational deformation. (2–3) Spring-mounted masses deflected opposite to the direction of acceleration. (4) Human vertical motion did not elicit nystagmus. (5) Sudden rotation caused tangential deflection. (6) Constant-speed circular motion led to outward (centrifugal) deflection.

Conclusion:

The utricle can detect four distinct forces—gravity, horizontal and vertical linear acceleration, tangential angular acceleration, and centrifugal force—which suggests broader roles in postural control. Although utricular hair cells are continuously stimulated by Earth’s gravity, no nystagmus is observed under static conditions. Thus, static utricular activation alone does not elicit nystagmus. However, further studies are needed to quantify these effects and determine their physiological significance.

Mechanism and Research Progress of Mitochondrial Quality Control in Osteoarthritis

Yan Li, Jiushe Kou — Tue, 22 Jul 2025 00:00:00 +0800

Osteoarthritis (OA) is a chronic disease characterized by degenerative lesions of articular cartilage, which is characterized by cartilage degeneration, bone redundancy formation and synovial inflammation. Recent studies have found that mitochondrial dysfunction is closely related to the development of OA. Mitochondrial quality control (MQC) mechanisms, including mitochondrial biogenesis, mitochondrial dynamics and mitochondrial autophagy, are essential for maintaining mitochondrial function. Therefore, targeted regulation of mitochondrial quality control is a promising therapeutic strategy. This article reviews the mechanism of MQC and its relationship with OA, as well as the research progress of targeting and regulating MQC to prevent and treat OA, aiming to provide a theoretical basis for the pathogenesis and preventive strategies of OA.

The Modulatory Effects of Tai Chi on the Circadian Rhythms and Sleep Quality of Seafarers in Different Navigational Regions

Mengjiao Guo, Haonan Zheng — Tue, 22 Jul 2025 00:00:00 +0800

The circadian rhythm and sleep quality of seafarers are critical for their health and maritime safety; however, both are highly susceptible to disruption by environmental factors specific to different navigational regions. In particular, trans-meridian (east-west) voyages involving rapid time-zone crossings, and high-latitude (north-south) voyages encountering polar day/night phenomena, can severely disrupt the human circadian system. This study aims to investigate the potential modulatory effects of Tai Chi, as a non-pharmacological and easily implementable mind-body intervention, on the circadian rhythms and sleep quality of seafarers under different navigational conditions and to explore its differential mechanisms. This paper first systematically analyzes the core challenges to circadian rhythms posed by two typical navigational regions: the former leading to phase desynchronization between the internal clock and the external environment, and the latter causing a deficiency or disturbance of the primary zeitgeber (light). Subsequently, the paper reviews the scientific evidence for Tai Chi’s role in regulating the autonomic nervous system, optimizing neuroendocrine rhythms, and improving sleep architecture. Based on this, a core theoretical model is proposed, positing that Tai Chi may act as a potent “non-photic zeitgeber”. Through regular, daily practice at a fixed time, it can provide a stable and predictable synchronizing signal to the seafarer’s internal biological clock. We further hypothesize that Tai Chi’s mechanism of action is context-dependent: during trans-meridian voyages, it primarily serves as a rhythmic anchor to accelerate phase re-entrainment and combat jet lag; during high-latitude voyages, it functions to substitute and enhance a weak or absent light signal, helping to maintain the stability of endogenous rhythms. To validate this model, a 2x2 factorial designed randomized controlled trial is proposed to prospectively compare changes in circadian rhythms (measured by actigraphy and salivary hormones) and subjective sleep quality between a Tai Chi intervention group and a control group across the two different navigational regions. This research not only aims to provide an innovative and scientific intervention for the sleep and rhythm problems faced by seafarers in extreme environments but also seeks to deepen the understanding of mind-body exercise as a form of behavioral chronotherapy, thereby opening new avenues for safeguarding the health and safety of special occupational populations.

Clinical Characteristics of Acute Anterior Talofibular Ligament Injury in Children with Negative X-ray Fractures

Yangkun Ding — Sun, 27 Jul 2025 00:00:00 +0800

The study aimed to explore the clinical characteristics of anterior talofibular ligament (ATFL) injury in children with negative X-ray fractures using musculoskeletal ultrasound.We analyzed a total of 85 children with low-energy ankle sprains who visited the orthopedic outpatient department of Jinan Children's Hospital from June 2023 to December 2024. All participants underwent X-ray and musculoskeletal ultrasound examinations.Based on the examination results, patients who showed fractures on X-rays and other soft tissue injuries such as ligaments on musculoskeletal ultrasound were further excluded.Finally, after strict screening, the included subjects were determined. Data on clinical examinations, X-rays, and musculoskeletal ultrasound examinations of all participants were collected. The degree of pain was assessed using the VAS pain scale, and the degree of ATFL injury was represented by the Kemmochi ultrasound standard.Finally, statistical analysis was conducted.The coincidence rate between the clinical diagnosis and ultrasound diagnosis of ATFL injury in 85 participants was 94.1%.The coincidence rate of X-ray and musculoskeletal ultrasound in the diagnosis of ankle fractures was 67.1%, and the Kappa value was 0.312. Ultimately, a total of 68 children with ATFL injury showing negative fracture results on X-rays were included, including 41 boys and 27 girls. The median age was 9.02 (95%CI,8.36-9.68), with 26 cases on the left side and 42 cases on the right side. The median injury time was 24 hours (95%CI,24.00-37.27). The median VAS pain score was 4.0 points (4.0,5.0). The most common musculoskeletal ultrasound classification was Kemmochi type V, accounting for 41.2%. In conclusion,ATFL injury is common in children with low-energy ankle sprain (94.1%). Clinical physical examination combined with musculoskeletal ultrasound diagnosis is of great significance. KemmochiⅤ was the most common type of ATFL injury with negative X-ray fractures.

Research on How Organizations can Effectively Reduce Occupational Stress and Burnout in the Long Term

Tianchen Tan — Wed, 06 Aug 2025 00:00:00 +0800

Occupational stress has become a rising problem in today’s job industries. Some jobs accumulate less stress than others and some accumulate more, however, almost every single employee in this decade has suffered at least some form of occupational stress in their career. Many researchers have been trying to study and resolve the trending problems. However, due to a lack of complete summarization and guide to counteracting the problem, many organizations and companies still struggle to provide a healthy working environment for their employees. This research will fill in the gap and accurately give the readers a complete summarization of strategies to reduce occupational stress and eliminate organizational ineffectiveness. In detail, this study will offer summarizations of topics of strategies to regulate employees’ well-being; how to take care of individuals’ mental health; how to spot occupational stress among employees; ways to spot organizational ineffectiveness within a group or company; past, well-known events that significantly increased employees’ occupational stress; and lastly how existing companies take care of their employees.