목적: 코로나19의 상황에서 대학생을 대상으로 스마트폰을 포함한 디지털기기의 사용이 눈과 근육뼈대계 통증에 미치는 영향을 알아보고자 하였다. 방법: 2022년 11월 온라인 설문조사에 응답한 대학생 156명의 자료를 분석하였다. 설문은 대상자의 일반적 특성을 포함하여 코로나19 대유행 동안 디지털기기의 사용시간과 종류, 컴퓨터시각증후군(computer vision syndrome, CVS) 16항목, 그리고 근육뼈대계 관련 11문항으로 구성하였다. CVS의 빈도는 0~2점, 강도는 1~2점으로 평가하였고, 근육뼈대계 통증은 약한 증상, 경도, 그리고 심한 증상으로 구분하여 3점 척도로 평가하여 총점을 산출하였다. 결과: 일일 평균 디지털기기의 사용은 7.97±3.46시간으로 온라인 수업을 위해 노트북(47.4%), 태블릿(33.3%), 데스크톱(12.2%), 그리고 스마트폰(7.1%)을 사용하였다. 매일 규칙적으로 운동하는 경우는 대상자의 22.4% 이었다. 컴퓨터시각증후군 관련 증상은 건조감이 가장 높은 점수를 보였고, 근육뼈대계 항목은 목 통증이 가장 심했다. 디지털기 기의 사용시간이 증가할수록 몸통(목, 등, 허리)과 전체 근육뼈대 통증이 심해졌고, 노트북이나 스마트폰을 이용해서 온라인 수업을 듣는 경우에는 데스크톱을 사용하는 경우와 비교해 상지통증 점수가 높게 나타났다. 매일 규칙적인 운동을 하는 경우에는 하지 않는 경우에 비해 컴퓨터시각증후군과 근육뼈대 통증의 통증이 작았다. 결론 : 디지털기기의 장시간 사용과 온라인 수업 동안에 사용하는 기기의 종류는 눈과 근육뼈대계 통증에 영향 을 미쳤다. 본 연구결과를 통해 이러한 환경에서 향후 눈과 근육뼈대계의 융합적인 연구와 관리가 함께 필요함을 알 수 있었다.

We have analyzed 42 research papers regarding on the solar astronomy written by North Korea scientists to investigate the current status of astronomical activities in North Korea. The papers are surveyed from the ‘Bulletin of Astronomy’, the ‘Physics’, the ‘Bulletin of Academy of Science’, and the ‘Natural Science’ in North Korea, and SCI journals. In addition, we refer to the presentation material announced in the 2015 IAU by director of Pyongyang Astronomical Observatory (PAO) and the 2013 OAD/IAU reports. We have analyzed the papers statistically according to three criteria such as research subject, research field, and research members. The main research subjects are the sunspot (28%), observation system (21%), and space environments (19%). The research fields are distributed with data analysis (50%), numerical method (29%), and instrument development (21%). There have been 25 and 9 researchers in the solar astronomy and space environment, respectively since 1995. North Korea’s solar research activities were also investigated in three area: instrument, solar physics, and international research linkage. PAO has operated two of sunspot telescope and solar horizontal telescope for spectroscopy and polarimetry, but there is no specific information on solar radio telescopes. North Korea has cooperated in solar research with Europe and China. We expect that the results of this study will be used as useful resource in supporting astronomical cooperation between South and North Korea in the future.

We investigate the solar cycle variation of microwave and extreme ultraviolet (EUV) intensity in latitude to compare microwave polar brightening (MPB) with the EUV polar coronal hole (CH). For this study, we used the full-sun images observed in 17 GHz of the Nobeyama Radioheliograph from 1992 July to 2016 November and in two EUV channels of the Atmospheric Imaging Assembly (AIA) 193 A° and 171 A° on the Solar Dynamics Observatory (SDO) from 2011 January to 2016 November. As a result, we found that the polar intensity in EUV is anti-correlated with the polar intensity in microwave. Since the depression of EUV intensity in the pole is mostly owing to the CH appearance and continuation there, the anti-correlation in the intensity implies the intimate association between the polar CH and the MPB. Considering the report of Gopalswamy et al. (1999) that the enhanced microwave brightness in the CH is seen above the enhanced photospheric magnetic field, we suggest that the pole area during the solar minimum has a stronger magnetic field than the quiet sun level and such a strong field in the pole results in the formation of the polar CH. The emission mechanism of the MPB and the physical link with the polar CH are not still fully understood. It is necessary to investigate the MPB using high resolution microwave imaging data, which can be obtained by the high performance large-array radio observatories such as the ALMA project.

The interest in the role of antioxidants in human health has prompted research in the fields of food science and horticulture to assess fruit and vegetable antioxidants such as ascorbic acid, anthocyanin, flavonoid, phenolic compounds, and total antioxidant activity. Free radicals have been known to cause degenerative diseases: cardiovascular disease, cancer, diabetes, and brain dysfunction. In this study, five cultivars of blueberries (Nelson, Duke, Bluejay, Toro, and Eliot) were harvested in two different maturity stages (unripe and ripe) to evaluate antioxidant activities and anti-dementia activities. Total phenolics and flavonoids of blueberries inthe ripe stage were higher than those in the unripe stage; alsothe total anthocyanin contentswere much higher in ripe fruits thanin unripe fruits. Antioxidant activities of ripen blueberries were greater than unripe fruits, especially; ‘Nelson’ and ‘Toro’ were higher than other cultivars. Total antioxidant activity was highly correlated with total flavonoids (r=0.8568) and phenolics (r=0.9637). However, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition of blueberries showed that unripe fruits were significantly higher than ripe fruits. In conclusion, there were several differences in antioxidant activities and anti-dementia activities of blueberry depending on fruit cultivars and the maturity stage at harvest. Therefore, unripe fruits also have potential health promoting bioactive compounds as a functional foodingredient.

Recently, Choe & Cheng (2002) have demonstrated that multiple magnetic flux systems with closed configurations can have more magnetic energy than the corresponding open magnetic fields. In relation to this issue, we have addressed two questions: (1) how much fraction of eruptive solar active regions shows multiple flux system features, and (2) what winding angle could be an eruption threshold. For this investigation, we have taken a sample of 105 front-side halo CMEs, which occurred from 1996 to 2001, and whose source regions were located near the disk center, for which magnetic polarities in SOHO/MDI magnetograms are clearly discernible. Examining their soft X-ray images taken by Yohkoh SXT in pre-eruption stages, we have classified these events into two groups: multiple flux system events and single flux system events. It is found that 74% (78/105) of the sample events show multiple flux system features. Comparing the field configuration of an active region with a numerical model, we have also found that the winding angle of the eruptive flux system is slightly above 1.5π.