• Biomolecules & Therapeutics
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• 제31권3호
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• pp.264-275
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• 2023

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by tremors, bradykinesia, and rigidity. PD is caused by loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN) and therefore, replenishment of DA neurons via stem cell-based therapy is a potential treatment option. Astrocytes are the most abundant non-neuronal cells in the central nervous system and are promising candidates for reprogramming into neuronal cells because they share a common origin with neurons. The ability of neural progenitor cells (NPCs) to proliferate and differentiate may overcome the limitations of the reduced viability and function of transplanted cells after cell replacement therapy. Achaete-scute complex homolog-like 1 (Ascl1) is a well-known neuronal-specific factor that induces various cell types such as human and mouse astrocytes and fibroblasts to differentiate into neurons. Nurr1 is involved in the differentiation and maintenance of DA neurons, and decreased Nurr1 expression is known to be a major risk factor for PD. Previous studies have shown that direct conversion of astrocytes into DA neurons and NPCs can be induced by overexpression of Ascl1 and Nurr1 and additional transcription factors genes such as superoxide dismutase 1 and SRY-box 2. Here, we demonstrate that astrocytes isolated from the ventral midbrain, the origin of SN DA neurons, can be effectively converted into DA neurons and NPCs with enhanced viability. In addition, when these NPCs are inducted to differentiate, they exhibit key characteristics of DA neurons. Thus, direct conversion of midbrain astrocytes is a possible cell therapy strategy to treat neurodegenerative diseases.

• Journal of Korean Neurosurgical Society
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• 제66권3호
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• pp.228-238
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• 2023

Intraventricular hemorrhage (IVH) is a serious concern for preterm infants and can predispose such infants to brain injury and poor neurodevelopmental outcomes. IVH is particularly common in preterm infants. Although advances in obstetric management and neonatal care have led to a lower mortality rate for preterm infants with IVH, the IVH-related morbidity rate in this population remains high. Therefore, the present review investigated the pathophysiology of IVH and the evidence related to interventions for prevention. The analysis of the pathophysiology of IVH was conducted with a focus on the factors associated with cerebral hemodynamics, vulnerabilities in the structure of cerebral vessels, and host or genetic predisposing factors. The findings presented in the literature indicate that fluctuations in cerebral blood flow, the presence of hemodynamic significant patent ductus arteriosus, arterial carbon dioxide tension, and impaired cerebral venous drainage; a vulnerable or fragile capillary network; and a genetic variant associated with a mechanism underlying IVH development may lead to preterm infants developing IVH. Therefore, strategies focused on antenatal management, such as routine corticosteroid administration and magnesium sulfate use; perinatal management, such as maternal transfer to a specialized center; and postnatal management, including pharmacological agent administration and circulatory management involving prevention of extreme blood pressure, hemodynamic significant patent ductus arteriosus management, and optimization of cardiac function, can lower the likelihood of IVH development in preterm infants. Incorporating neuroprotective care bundles into routine care for such infants may also reduce the likelihood of IVH development. The findings regarding the pathogenesis of IVH further indicate that cerebrovascular status and systemic hemodynamic changes must be analyzed and monitored in preterm infants and that individualized management strategies must be developed with consideration of the risk factors for and physiological status of each preterm infant.

• Steel and Composite Structures
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• 제48권4호
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• pp.367-383
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• 2023

A coupled wall consists of two or more reinforced concrete (RC) shear walls (SWs) connected by RC coupling beams (CBs) or steel CBs (hybrid-coupled walls). To fill the gap in the literature on the plastic hinge length of coupled walls, including coupled and hybrid-coupled shear walls, a parametric study using experimentally validated numerical models was conducted considering the axial stress ratio (ASR) and coupling ratio (CR) as the study variables. A total of sixty numerical models, including both coupled and hybrid-coupled SWs, have been developed by varying the ASR and CR within the ranges of 0.027-0.25 and 0.2-0.5, respectively. A detailed analysis was conducted in order to estimate the ultimate drift, ultimate capacity, curvature profile, yielding height, and plastic hinge length of the models. Compared to hybrid-coupled SWs, coupled SWs possess a relatively higher capacity and curvature. Moreover, increasing the ASR changes the walls' behavior to a column-like member which decreases the walls' ultimate drift, ductility, curvature, and plastic hinge length. Increasing the CR of the coupled SWs increases the walls' capacity and the risk of abrupt shear failure but decreases the walls' ductility, ultimate drift and plastic hinge length. However, CR has a negligible effect on hybrid-coupled walls' ultimate drift and moment, curvature profile, yielding height and plastic hinge length. Lastly, using the obtained results two equations were derived as a function of CR and ASR for calculating the plastic hinge length of coupled and hybrid-coupled SWs.

• Ocean and Polar Research
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• 제45권2호
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• pp.71-87
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• 2023

Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

• Journal of Korean Neurosurgical Society
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• 제66권1호
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• pp.82-89
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• 2023

Objective : Rathke's cleft cysts (RCCs) are nonneoplastic cysts. Most of them are asymptomatic and stable; when symptomatic, RCCs are surgically fenestrated and drained. However, the outcomes remain unclear. The authors evaluated the outcomes of RCC decompression. Methods : Between 2004 and 2019, 32 RCCs were decompressed in a single tertiary institution. The clinical characteristics, intraoperative findings, postoperative complications, and endocrinological and surgical outcomes were retrospectively reviewed. Patients who underwent sequential imaging at least twice and at least 12 months after surgery were included in the analysis. Results : Patients' mean age was 40.8±14.9 years, and 62.5% were women. The mean follow-up duration was 62.3±48.6 months. In 21 patients (65.6%), no residual cysts were identified on postoperative magnetic resonance imaging. Of the 18 patients with preoperative visual field defects, 17 (94.4%) experienced postoperative visual improvement. Postoperative complications included endocrinological deterioration in 11 patients (34.4%), permanent diabetes insipidus in 11 (34.4%), infection in four (12.5%), intrasellar hemorrhage in three (9.4%), and cerebrospinal fluid leak in two (6.3%). Follow-up images revealed cyst recurrence in nine patients (28.1%), an average of 20.4 months after surgery; in three patients, the cysts were symptomatic, and resection was repeated. Multivariable analysis revealed that postoperative endocrinological deterioration was the only independent factor associated with cyst recurrence (p=0.028; hazard ratio, 6.800). Conclusion : Our findings showed that although only cyst fenestration for decompression was performed to preserve pituitary function, more pituitary dysfunction occurred than expected. Besides, the postoperative hormonal deterioration itself acted as a risk factor for cyst recurrence. In conclusion, surgery for RCC should be more careful.

• 한국안전학회지
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• 제38권1호
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• pp.70-77
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• 2023

Gas has replaced coal or petroleum as primary fuel because of its convenience. However, gas has risk of fire, explosion, or poisoning. To reduce gas-related accidents, many strategic projects have been being carried based on 'Gas Safety Management Basic Plans' on a domestic scale. In spite of those projects, the gas-related accident rate did not decrease over past decades. Thus, this study was conducted to analyze the effectiveness of ongoing projects, and to find out ways to make improvements. Conventional statistical analyses on accident data published by gas-related institutions were not useful to determine meaningful attributes to predict future. Whereas, accident case analyses adopted in the present study discovered differences in the type of people and their unsafe acts for each gas type. Meanwhile, the overall average priority of projects was not high in the aspect of System Safety Precedence. If the current trend is maintained, with sigmoid functions, it can be estimated that mean annual accident rate will decrease by only 2.0% in the next two decades. To improve the current trend, the present study made conclusions as followings: (1) safety projects should be designed with careful consideration of accident traits including gas type, unsafe acts, and persons involved and (2) alternative strategies should include system considerations such as minimum hazard design and safety devices prior to mere education or training. To summarize briefly, the present state related with gas accidents highlights the necessity of a system-based multidisciplinary approach.

• 융합정보논문지
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• 제12권3호
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• pp.55-65
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• 2022

파킨슨병 노인은 낙상의 신체적, 정신적 위험요인을 가진 비율이 비 파킨슨병 노인에 비해 높아, 파킨슨병 노인의 낙상 경험 유무에 따라 낙상에 영향을 주는 신체적, 정신적 위험요인을 한국 노인 전체를 모집단으로 하는 국가 데이터를 이용하여 규명하였다. 2017년 보건복지부의 노인실태 자료조사를 이용한 2차 분석연구로, 파킨슨병 노인은 총 103명이었으며 결측값을 제외하고 총 96명의 대상자를 분석하였다. 파킨슨병 노인에게서 낙상에 가장 큰 영향을 미치는 요인은 IADL로 나타났으며, IADL은 운동 조절기능과 관련이 있다. 운동 조절기능의 저하는 일상생활에 필수적으로 요구되는 신체 움직임에 제약을 가하며 위급상황에서의 자기 보호적 행동까지도 영향을 미쳐 낙상에 영향을 미친다. IADL이 낙상에 영향을 줄 수 있다는 본 연구결과를 바탕으로 파킨슨병 노인의 낙상 예방 중재를 위한 다양한 운동요법을 제안할 수 있을 것이다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.320-322
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• 2021

세계적으로 고령 인구가 증가함에 따라 시각장애인의 비율 역시 증가하고 있으며, 여전히 안전상에 문제, 안내정보 부족 등 시각장애인이 외부 활동을 하는 데에 있어서 많은 제약이 존재한다. 이를 해결하기 위해 광학 문자 인식(OCR) 기능이 탑재된 스마트 안경 등 스마트 기기에 관한 연구가 활발히 진행되고 있다. 본 논문에서는 전방에 장애물을 인식해 음성으로 정보를 알려주고, 목적지까지 길을 안내해주는 시스템을 제안한다. 딥러닝 객체 인식 모델인 Yolo를 이용하여 계단, 라바 콘과 같은 위험요소를 장애물로 인식하고 음성으로 정보를 전달해주며, 길 찾기 API와 음성인식, TTS 라이브러리를 사용하여 입력한 목적지까지 음성으로 길 안내를 해줌으로써 시각장애인의 외부 활동 범위가 확대되는 효과를 기대할 수 있다.

• 정보보호학회논문지
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• 제33권1호
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• pp.45-50
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• 2023

세계 1위 메타버스 플랫폼인 로블록스(Roblox)의 경우, 30억개 이상의 가입 계정과 1억 5천만명이상에달하는월간 활성 이용자수(MAU)를 기록하고 있다. 이렇듯 메타버스에 대한 높은 관심에도, 메타버스 환경의사이버공격위험성과 보안에 관한 연구는 매우 부족하다. 따라서, 본 연구에서는 대표적인 메타버스 환경인 로블록스에서의스테가노그래피 기반 은닉통신 기법에 대해 연구하였다. 구체적으로, 로블록스 체험 환경을 통해 은닉 메시지를이미지에삽입하고체험 참가자(user)들의 단말기에 자동으로 해당 이미지가 저장된 후 은닉한 메시지 역시 성공적으로추출됨을실험을통해 확인하고 결과를 제시한다. 이를 통해, 메타버스 환경에서 은밀한 비밀 지령 전파, 스테가노그래피봇넷구축, 악성 Malware 대량 유포 등 다양한 사이버공격과 범죄에 악용될 가능성을 확인하고 알리고자 한다.

• Journal of Hospice and Palliative Care
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• 제25권2호
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• pp.55-65
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• 2022

Caring for patients with cancer is highly stimulating and rewarding, attracting health professionals to the field who enjoy the challenge of managing a complex illness. Health professionals often form close bonds with their patients as they confront ongoing disease or treatment impacts, which may be associated with multiple losses involving function and/or eventual loss of life. Ongoing exposure to patient loss, along with a challenging work setting, may pose significant stress and impact health professionals' well-being. The prevalence rates of burnout and compassion fatigue (CF) are significant, yet health professionals have little knowledge on these topics. A 6-week continuing education program consisting of weekly small-group video-conferencing sessions, case-based learning, and an online community of practice was delivered to health care providers providing oncology care. Program content included personal, organization and team-related risk and protective factors associated with CF, grief models, and strategies to mitigate against CF. Content analysis was completed as part of the program evaluation. In total, 189 participants (93% nurses) completed the program, which was associated with significant improvements in confidence and knowledge of CF and strategies to support self and team resilience. Qualitative themes and vignettes from experiences with the program are presented. Key themes included knowledge gaps, a lack of support related to CF and strategies to support resilience, organization-and team-based factors that can inhibit expression about the impacts of clinical work, the health professional as a "person" in caregiving, and the role of personal variables, self-skill practices, and recommendations for education and support for self and teams.