Background: The progressive digitalization of contemporary life, coupled with prolonged sedentary behavior, has contributed to the widespread occurrence of forward head posture (FHP) in the general population. Among the various exercise interventions aimed at correcting FHP, stretching exercises and proprioceptive training have garnered significant attention. Objectives: To investigate the effects of stretching exercises and proprioceptive training on craniovertebral angle (CVA), an indicator of forward head posture (FHP), and on the muscle tone of the suboccipital muscles. Design: Randomized controlled trial. Methods: Thirty participants were randomly assigned to either the stretching exercise group (n=15) or the proprioceptive training group (n=15), and each group underwent intervention three times per week for six weeks. CVA and muscle tone of the suboccipital muscles were measured before and after the six-week intervention, and the results were statistically analyzed for comparison. Results: Both groups showed a significant increase in CVA after the intervention (P<.05), with no significant difference between the groups. The muscle tone of the suboccipital muscles did not show statistically significant changes either within or between the groups. Conclusion: Six weeks of stretching exercise and proprioceptive training both resulted in a significant increase in CVA, demonstrating that both interventions are effective in improving FHP. However, neither intervention produced significant changes in the muscle tone of the suboccipital muscles.

The objective of this study was to assess the effects of gypsum application on dry matter yield (DMY), mineral content of alfalfa (Medicago sativa L.), and soil properties in reclaimed tidal land in South Korea. The experiment was conducted in Seokmun, located on the west coast of South Korea, which is reclaimed with approximately 70 cm depth of degraded island soil. Treatments consisted of a control with no gypsum application (G0), 2 ton ha-1 (G2), and 4 ton ha-1 (G4) of gypsum application. The first harvest was carried out when the alfalfa reached 10% flowering, and subsequent harvests were conducted at 35-day intervals. Over the three-year experimental periods (2019-2021), the total DMY of G2 treatment was significantly higher than those of G0 and G4 (p<0.05). Although both G2 and G4 gypsum application treatments lowered soil pH, the G4 treatment increased the electrical conductivity (EC) content of the soil. Additionally, gypsum application affected the mineral contents of alfalfa, resulting in reduced concentration of sodium (Na) and Magnesium (Mg). Therefore, this present study suggests that a gypsum application rate of 2 ton ha-1 is optimal for improving alfalfa dry matter yield and mineral balance, as well as enhancing soil chemical properties in reclaimed tidal land in South Korea.

Virtual Reality Head Mounted Display (VR HMD)-based flight simulators have recently emerged as promising tools for enhancing pilot training effectiveness. This study aims to establish a set of evaluation criteria for the development of VR HMD-based flight simulators and to determine their relative importance and priority using the Analytic Hierarchy Process (AHP). Through an extensive review of the literature, a hierarchical evaluation model was constructed, consisting of three primary criteria and ten sub-criteria. A structured questionnaire was administered to experienced pilots, and the collected data were analyzed using the AHP methodology to assess the relative weights of each criterion. The analysis revealed that the fidelity of system performance is the most influential factor in evaluating VR HMD-based flight simulators. These findings present a structured evaluation framework and offer practical insights for guiding the strategic development and optimization of VR HMD-based flight training systems.

본 사례 보고는 소아 뇌 자기공명영상(MRI) 검사에서 협조가 원활하지 않아 움직임에 의한 인공물이 발생하고, 이로 인해 시간차 자기공명혈관촬영(TOF MRA) 영상의 획득이 어려운 상황에서, 삼차원 구조화 자기공명영상(3D MPRAGE)을 수평면(axial) 방향으로 획득한 후 최대강도투사(MIP) 기법을 적용하여 혈관 형태를 성공적으로 시각 화한 사례를 소개하고, 그 임상적 유용성을 평가하고자 한다. 영상 획득 시, TOF MRA는 약 7분, 3D MPRAGE는 약 4~5분의 검사 시간이 소요되었으며, 3D MPRAGE는 짧은 촬영 시간과 인코딩 방향 변경으로 인한 움직임 감소 효과를 보였다. 수평면 3D MPRAGE 영상은 주요 뇌혈관을 효과적으로 시각화하였고, 진단 해상도 면에서도 TOF 영상과 비교해 손색이 없었다. 본 사례 보고는 특히 협조가 어려운 1세에서 7세 사이의 소아 환자에서 3D MPRAGE 기반 MIP 영상이 TOF 영상의 효과적인 대안이 될 수 있음을 시사한다. 또한 혈류 흐름 방향에 맞추어 MPRAGE의 획득 단면을 조정하고 수평면 영상에 MIP 기법을 적용함으로써 뇌혈관 구조 시각화를 최적화할 수 있었다. 비록 미세혈관 표현에는 TOF 영상 대비 한계가 있었으나, 주요 대혈관 영상은 충분한 진단 정보를 제공하였다. TOF 영상 이 혈관에 특화된 반면, 3D MPRAGE는 뇌 실질 영상과 함께 뇌혈관 형태 영상까지 제공할 수 있어, 진정이 필요한 소아 환자에게 보다 유리한 대안이 될 수 있다. 이러한 접근은 검사 시간을 단축시키고, 뇌혈관 질환과 관련된 부가 적인 임상 정보를 함께 제공함으로써 영상의 진단적 가치를 향상시킬 것으로 기대된다.

Maca has been reported to alleviate male menopause symptoms in humans and experimental animals; however, its mechanism of action in improving male menopause has not been clearly identified. This study aimed to investigate the mechanism of action of gelatinized maca in improving male menopause by analyzing serum testosterone, testicular androgen receptor (AR) expression, and testicular oxidation-antioxidation balance. Gelatinized maca was administered orally to aged male C57BL/6 mice at three doses (500, 1,000, and 1,500 mg/kg/day) for 28 consecutive days. Serum biochemical analysis showed an increase in serum hydroxysteroid 17-beta-dehydrogenase 13 (HSD17β13) concentration at 1,500 mg/kg/day and a decrease in serum sex hormone-binding globulin (SHBG) concentration at ≥ 1,000 mg/kg/day. Gelatinized maca administration also resulted in the increased expression levels of testicular AR and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) at 1,500 mg/kg/day. Oxidative stress analysis showed an increase in testicular superoxide dismutase and glutathione reductase activities and a decrease in testicular malondialdehyde at 1,500 mg/kg/day. In conclusion, gelatinized maca administration to aged male mice increased HSD17β13, AR and CREB expression, and antioxidant capacity and decreased serum SHBG. The results of the present study suggest that gelatinized maca may be a useful substance that can help alleviate male menopause symptoms.