Background: With rapid advances in digital technology, tablet PC use among university students has increased significantly. While convenient, prolonged use often causes neck and shoulder discomfort due to poor posture, such as forward head posture and rounded shoulders. Although students commonly use tablets for writing, there is limited research on head movements during these tasks. Objects: To compare frontal plane head movements and tablet tilt angles between college students with and without neck pain during tablet PC use. Methods: Participants were divided into two groups based on neck pain presence (neck pain group and no pain group). Each participant sat at a table, adjusted the tablet stand angle independently, and placed the tablet accordingly. Participants wore earphones and dictated English sentences to ensure focused handwriting and the evaluator recorded all process. These video recordings of handwriting sessions were analyzed for frontal plane head movements using Kinovea software. The Wilcoxon signed-rank test was applied to reveal the group differences in tablet tilt angle, total head movement (THM), horizontal head movement (HHM), and vertical head movement (VHM). Results: There were no significant differences between the neck pain and no neck pain groups in tablet tilt angle or HHM (p > 0.05). In contrast, the neck pain group exhibited significantly greater THM (p < 0.001) and VHM (p < 0.01). Conclusion: The findings of this study indicate no significant relationship between neck pain and tablet tilt angle or HHM, but a significant association with increased VHM and THM. These findings provide basic knowledge for understanding movement patterns in individuals with neck pain.
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.
Background: Dairy cows exposed to heat stress have reduced milk production, milk quality, and conception rates, leading to lower profits. This study was conducted to analyze the effect of heat stress according to Temperature-Humidity Index (THI) on the milk production of Korean Holstein cows. Methods: Monthly maximum temperature and average relative humidity data from January 2017 to August 2024 were obtained from 62 observation points used by the Korea Meteorological Administration to calculate the national average. Using this data, the THI, a key indicator for assessing heat stress in Korean Holstein cows, was calculated. Additionally, data from 240,088 Korean Holstein cows, collected through tests conducted by the Dairy Cattle Improvement Center of the NH-Agri Business Group, were analyzed. Results: Comparative analysis of the relationship between THI and milk production revealed that milk yield remained relatively stable until THI reached the “very severe” heat stress threshold (THI ≥ 79). Beyond this level, milk production showed a tendency to decline. Conversely, when THI dropped below this threshold, milk yield tended to recover. Notably, the temperature in September, typically considered part of the autumn season, has been rising in recent years, with THI values now approaching the very severe stress level (THI ≥ 79). Conclusions: These findings suggest that establishing an appropriate farm environment and implementing systematic THI management are essential for mitigating the decline in milk production, as well as the associated economic losses, caused by rising domestic temperatures due to global warming.
본 연구는 우리나라에 자생하는 목본 관상용 식물인 먼나무 (Ilex rotunda)와 으름덩굴(Akebia quinata)을 대상으로 삽목 효율을 분석하였다. 삽수는 녹지와 숙지로 구분하고 생장조절 제 indole-3-butyric acid (IBA)와 시판용 발근촉진제 루톤 (Rootone)을 처리하여 대조군과 비교하였다. 그 결과, 발근율 (녹지, 숙지)은 먼나무(50.9, 19.0%) 및 으름덩굴(52.8, 28.5%) 로 두 수종 모두 숙지보다는 녹지가 손쉽게 발근되었다. 생장조절 제의 발근 촉진 효과는 녹지보다는 숙지에서 두드러졌으며, 생장 조절제 효과는 두 수종에서 상이하게 나타났으며, IBA와 루톤에 대한 두 수종의 발근 반응이 다르게 나타냈다. IBA 1,000ppm 처리는 먼나무의 발근을 촉진시켰고(65.9%) 으름덩굴에서는 고 사에 따른 발근율 저하를 야기하였으며(5.0%), 오히려 으름덩굴 은 루톤 처리로 발근이 촉진되었다(83.3%).
Amitriptyline hydrochloride (AMT), a tricyclic antidepressant, is known to exhibit antimicrobial effects against a wide range of bacterial species. This study aims to evaluate the effect of AMT on Brucella (B.) abortus infection in RAW 264.7 cells and ICR mice, which has not yet been clearly characterized. The results showed that all tested concentrations of AMT had no direct bactericidal effect on B. abortus survival at any incubation time point. Interestingly, RAW 264.7 cells pre-treated with a non-toxic high concentration of AMT before B. abortus infection showed a significant reduction in the phagocytosis of B. abortus at 20 min post-infection, compared to untreated cells. However, AMT treatment did not affect the intracellular replication of B. abortus compared to the control cells. Based on the reduced bacterial uptake observed in-vitro, an in-vivo experiment was conducted to assess whether daily oral administration of AMT at a dose of 20 mg/kg could inhibit B. abortus growth in ICR mice. The results showed that AMT treatment slightly increased both organ weights and bacterial loads, suggesting possible systemic effects of prolonged AMT exposure. In summary, these preliminary results provide initial insight into the potential effects of AMT on B. abortus infection both in-vitro and in-vivo. Therefore, further study should focus on dose optimization in-vivo and exploration of the underlying cellular mechanisms involved in AMT-mediated inhibition of phagocytosis during Brucella infection.
Recent global efforts to combat climate change have accelerated, with nations adopting carbon strategies such as carbon taxes and emission trading system (ETS) to support their net-zero commitments. These initiatives enable governments to enforce mitigation while maintaining their dual goal of fostering economic growth. Vietnam, a developing country, has emerged as a proactive participant by launching a national ETS, drawing from international best practices and domestic geographical advantages. This article examines the process and challenges involved in designing and implementing an ETS in Vietnam, exploring the necessary policy frameworks, institutional structures, and market mechanisms. It highlights key considerations such as the selection of sectors and entities to be covered, the allocation of emission allowances, and the establishment of new market management solutions. This article concludes with strategic recommendations to support the development of a successful and sustainable ETS mechanism in developing country like Vietnam.
곤충 Laccifer lacca의 분비물인 stick lac에서 얻어지는 락색소는 물에 용해되는 붉은색 식용 색소로, 식품에 붉 은 색을 더하는 착색제이다. 주요 성분은 안트라퀴논계 기 반의 laccaic acid로 A, B, C, D, E로 구성된다. 본 연구 의 목적은 HPLC-DAD를 활용하여 laccaic acid를 정량적 으로 분석할 수 있는 방법을 검증하는 것과 섭취 노출량 을 산출하는 것이다. 제안된 분석법은 특이성, 선형성, LOD, LOQ, 정확성, 정확도 등 다양한 검증 항목에서 평 가되었으며, 매트릭스 효과 또한 충분히 고려되었다. 모든 매트릭스에서 검량선은 높은 선형성 (R20.999)을 보였고, 락색소의 MDL과 MQL은 각각 1.93 mg/kg와 5.86 mg/ kg로 확인되었다. 일내 및 일간 회수율 시험에서 정확도 는 91.5-100.9% 사이였고, 정밀도는 0.8-2.6%RSD로 AOAC 기준을 충족하였다. 한국에서 유통되는 다양한 식 품들을 수집하여 락색소를 모니터링하여 식품 유형별 락 색소 섭취 노출량을 평가하였다. 락색소 섭취 수준의 범 위는 국민전체, 섭취자 각각 0.0000-0.0027 mg/kg·bw/day 와 0.0000 -0.0306 mg/kg·bw/day였다. 개발된 분석법은 다 양한 식품 유형에 적용 가능하여 락색소 추출물의 효과적 인 모니터링을 가능하게 하며, 섭취량 평가를 통해 락색 소의 안전성 평가에 추가적으로 활용될 수 있을 것이다.
Background: During daily activities, stability is maintained to enhance the function of muscles surrounding the lumbopelvic and hip structures. The core muscles such as the rectus abdominis (RA), external oblique (EO), and internal oblique (IO) responsible for this stability. One effective static exercise for strengthening these muscles is the plank. Objects: This study aimed to compare abdominal electromyographic activation when an unstable support surface was applied to the upper and lower extremities during a standard and a knee plank. Methods: A total of 30 adults (15 males and 15 females) participated in this study. Surface electromyography electrodes were placed on the RA, EO, and IO muscles. Data were collected under six conditions for males, including two plank postures (standard and knee planks) and three unstable surface conditions (a dynamic balance cushion applied to the upper extremities, lower extremities, or no cushion). Female participants performed only the knee plank. A mixed-effects model with a random intercept was used to analyze muscle activation across plank posture and surface position, with statistical significance set at α = 0.05. Results: In males, the standard plank elicited greater muscle activation than the knee plank across all muscles (p < 0.0001). Additionally, applying an unstable support surface to the upper extremities significantly increased muscle activation in both plank postures in EO and IO (p < 0.001). Other muscle, RA, was only affected by the unstable support surface in the standard plank position only. In females, the knee plank with upper limb instability resulted in the highest muscle activation for all muscles. Conclusion: These findings highlight the importance of surface instability in core muscle engagement. However, future studies should further investigate abdominal muscle activation with a more detailed analysis and the inclusion of a control group to enhance comparative validity.