목적 : 본 연구는 DIMS(Defocus Integrated Multiple Segments) 렌즈와 HALT(High Aspureral Lenslet Target) 렌즈의 근시 진행 지연 효과를 평가하는 것이다. 방법 : 본 연구는 6세에서 16세 사이의 어린이를 대상으로 두 개의 시험군과 대조군으로 나누어 12개월 간 진 행하였다. 근시 조절을 위해 근시성 디포커스 원리를 사용하는 두 가지 유형의 안경 렌즈가 사용되었다. 효과를 평 가하기 위해 디포커스 다중 세그먼트(DIMS) 및 고도 비구면 마이크로렌즈(HALT)가 사용되었다. 대상자는 102명 (204안)이며, DIMS 그룹은 34명, HALT 그룹은 35명, SV 그룹은 33명이었다. 초기 변화를 평가하기 위해 3개월, 6개월, 12개월에 측정하였고, 등가구면굴절력(SER)과 안축장(AL) 길이의 변화를 비교 분석하였다. 결과 : 모든 그룹에서 처음 방문 검사는 조절마비 후 검사를 시행하였고, 등가구면굴절력은 평균–2.94±0.11 D, 안축장은 평균 24.73±0.06 mm였다. DIMS와 HALT 두 시험군에서 등가구면굴절력 평균은 0.30±0.02 D, 0.23± 0.02 D, 대조군(SV) 그룹에서 0.50±0.04 D였다. 평균 안축장의 변화는 DIMS와 HALT 및 SV 그룹에서 각각 0.13±0.01 mm, 0.13±0.01 mm, 0.21±0.03 mm였다. 등가구면굴절력 변화에 의한 근시 진행은 DIMS 와 HALT 그룹의 대상자가 대조군 그룹에 비해 각각 39.45%, 53.03% 더 느리게 진행되었다(P<0.05). 안축장 길 이 변화에 의한 근시 진행은 DIMS와 HALT 그룹의 대상자가 대조군 그룹에 비해 각각 39.23%, 41.01% 더 느리 게 진행되었다(P<0.05). 결론 : 1년 동안 근시진행을 비교한 결과, DIMS와 HALT 그룹 모두 SV 그룹보다 등가구면굴절력 변화와 안축 장 길이 증가를 현저히 감소시켰다. 따라서 두 가지의 광학적 방법인 DIMS 렌즈와 HALT 렌즈를 사용하는 것이 소아·청소년의 근시 조절에 효과적인 전략임을 시사한다.
Industrial activities that utilize nuclear technology can cause radioactive contamination in the ecosystems. In particular, cesium (Cs) has problems, such as neurological diseases, when it is exposed and accumulated in the bodies of animals, plants, and humans for a long time. Therefore, the development of simple and economical adsorbents for Cs removal is required. In this study, the surface of petroleum residue pitch was modified using NaClO and it was used to remove Cs from an aqueous solution. Batch experiments and characterization of the modified adsorbent were performed to determine the adsorption mechanism between the adsorbent and Cs. From these results, chemical and monolayer adsorption were found to occur at the carboxyl groups on the adsorbent surface, along with a cation exchange reaction occurred due to the sodium ions on the surface. Through this modification process, the total acidity, including phenolic, lactonic and carboxylic functional groups, was improved to 1.563 mmol/g and the maximum adsorption capacity of Cs for the modified adsorbent was 65.8 mg/g.
The purpose of this study is to analyze effect of Army Risk Assessment System(ARAS) which is used to prevent safety accident in ROK army. Based on prior research, we select 4 indicators which are related to accident prevention effect and analyze the differences before and after ARAS operation for each indicators by using Paired-Samples T-Test. Also, we analyze the correlation between degree of ARAS operation and status of safety accidents of 112 ROK Army units. We conduct an evaluation of each function within the system using IPA method. The results of this study are as follows; All 4 indicators are improved compared to before ARAS operation, and the differences are statistically significant. Also, there is negative correlation between the degree of ARAS operation and the occurrence of safety accidents. So, the operation of ARAS has a positive effect on preventing safety accidents. Finally among the 15 functions of ARAS, 4 functions require improvement. The findings of this study have implications for proposing necessity of computerized system in enforcing Risk Assessment. Also, whether or not operating ARAS is important, but it is also important to operate it well. Lastly, We propose improvement plans for each function to operate it well.
Drug-induced liver injury (DILI) is considered to be a significant cause of drug wastage. To mitigate clinical DILI risks, assessing drugs using human liver models is crucial since animal studies may fall short due to species-specific liver pathway variations. Cell-based preclinical hepatotoxicity testing is often pertinent. In the present study, cells from a human liver cancer line (HepG2 and HepaRG) were cultured in both formats of 2D and 3D spheroids to explore their responses to drugs. Liver-specific marker expressions across cell lines and culture formats were also examined to assess disparities in DILI marker expressions. After treating each cell with the drugs, cytotoxicity and liver injury markers aspartate aminotransferase and alanine aminotransferase were increased. In addition, liver specific markers albumin and urea decreased in a drug concentration-dependent manner. These findings were consistent with drug sensitivity. Additionally, mRNA expression levels of cytochrome P450 enzymes (CYPs) involved in hepatocellular drug metabolism were compared following treatment with enzyme inducers. CYP1A2 and CYP2C9 were not epxressed in HepG2 cells. HepaRG cells exhibited significantly increased expression of CYP1A2, 2C9, and 3A4 post-treatment. Notably, enzyme expression was notably higher in 3D cultures than in 2D cultures. Collectively, these findings suggest that HepaRG cells and 3D cultures hold promise for evaluating DILI during early-stage drug development.
Background: Sleep accounts for approximately one-third of a person’s lifetime. It is a relaxing activity that relieves mental and physical fatigue. Pillows of different sizes, shapes, and materials have been designed to improve sleep quality by achieving an optimal sleep posture. Objects: This study aimed to determine which pillow provides the most comfortable and supports the head and neck during sleep, which may enhance sleep quality. Methods: Twenty-eight healthy adults (19 males and 9 females) with an average age of 29 years participated in this cross-sectional study. This experiment was conducted while the participants laid down for 5 minutes in four different pillow conditions: (1) no pillow (NP), (2) neck support foam pillow (NSFP), (3) standard microfiber filled pillow (SFP), and (4) hybrid foam pillow (HFP). The head-neck peak pressure, cranio-vertebral angle in supine (CVAs), cranio-horizontal angle in supine (CHAs), chin-sternum distance (CSD), and muscle tone of sternocleidomastoid were analyzed using one-way repeated measures analysis of variance (ANOVA). The significance level was set at p < 0.05. Results: The head-neck peak pressure was the highest in the NSFP condition, followed by the NP, SFP, and HFP conditions. The CVAs, CHAs, and CSD of the SFP were lower than those of the other pillows. Muscle tone was the highest in the NP condition, followed by the of NSFP, HFP, and SFP conditions. The participants subjective comfort level in both the supine and side-lying postures was highest in the HFP condition, followed by the SFP and NSFP conditions. Conclusion: This study can be used to establish the importance of pillow selection for highquality sleep. The results of this study, suggest that a hybrid pillow with a good supportive core and appropriate fluffiness can maintain comfort and correct cervical spine alignment during sleep.
본 논문의 목적은 한국이 직면한 뉴테러리즘 양상과 위협 요인을 분석해보고, 선제적으로 대응할 수 있는 과제에 대해 제시해 봄에 있다. 현재 한국은 포괄적 안보상황 하에서 대중과 다중이용시설 대상 무차별적 공격의 사전 차단 및 대량살상 등 전방위적으로 테러위협에 대응하고 있다. 이에 이 논문에서는 테러 수단의 첨단화 및 고도화되고 있는 뉴테러리즘에 대해 선제적으로 국가 및 국민적 인식을 강화하고 취약점 보완을 위해 법률적, 제도적 대응 방안을 제시했다. 또 포괄적 안보 상황을 반영하여 국내 테러 양상을 분석하고, 테러예방시스템 구축을 위한 통합방위법 및 테러방지법의 상호 연계성과 사법집행 강화를 위한 근거를 마련해야 한다. 특히 AI 기반의 테러예방 및 대응 시스템 등 4차 산업혁명의 신기술 적용을 토대로 테러위협을 선제적 으로 차단하고 이 같은 기술을 활용하는 대테러업무 담당자를 대상 으로 교육훈련을 강화할 수 있는 방안 역시 마련해야 한다.
Abstract Purpose : The purpose of this study is to compare corneal curvature, corneal topography, and non-surgical in refraction correction surgery to determine the difference in corneal curvature and shape between the two groups. Methods : The subjects of this study were 30 persons (60 eyes) who underwent refractive surgery and 30 non-surgery persons (60 eyes) who had no systemic or eye disease over the age of 20. The research method measured refractive error and corneal curvature in two groups using an autorefractor-keratometer, measured curvature by area of the cornea using corneal topography, and compared refractive surgery eyes and non-surgery eyes. Results : In area-specific corneal curvature, the plan for refractive surgery was 8.48±1.05 mm in area A (0~1.5 mm), 8.49±1.58 mm in area B (1.5~4.5 mm), 8.19±1.87 mm in area C (4.5~7.5 mm), and 7.93±2.87 mm in area D (7.5~10.0 mm). In non-surgery procedures, the corneal curvature by area was 7.65±0.82 mm in area A, 7.77±1.56 mm in area B, 7.70±2.27 mm in area C, and 7.88±3.42 mm in area D. Conclusion : A side effect of refractive surgery, it is believed that it can be used as data to understand the shape of the cornea while using an Autorefractor-keratometer and a corneal topography as prior tests. Key words : Corneal topography, Keratometer, Refractive surgery
Changes in the microstructure and mechanical properties of as-roll-bonded AA6061/AA5052/AA1050 threelayered sheet with increasing annealing temperature were investigated in detail. The commercial AA6061, AA5052 and AA1050 sheets with 2 mm thickness were roll-bonded by multi-pass rolling at ambient temperature. The roll-bonded Al sheets were then annealed for 1 h at various temperatures from 200 to 400 °C. The specimens annealed up to 250 °C showed a typical deformation structure where the grains are elongated in the rolling direction in all regions. However, after annealing at 300 °C, while AA6061 and AA1050 regions still retained the deformation structure, but AA5052 region changed into complete recrystallization. For all the annealed materials, the fraction of high angle grain boundaries was lower than that of low angle grain boundaries. In addition, while the rolling texture of the {110}<112> and {123}<634> components strongly developed in the AA6061 and AA1050 regions, in the AA5052 region the recrystallization texture of the {100}<001> component developed. After annealing at 350 °C the recrystallization texture developed in all regions. The as-rolled material exhibited a relatively high tensile strength of 282 MPa and elongation of 18 %. However, the tensile strength decreased and the elongation increased gradually with the increase in annealing temperature. The changes in mechanical properties with increasing annealing temperature were compared with those of other three-layered Al sheets fabricated in previous studies.
Various types of radioactive liquid and solid wastes are generated during the operation and decommissioning of nuclear power plants. To remove radionuclides Co-60, Cs-137 etc. from a liquid waste, the ion-exchange process based on organic resins has been commonly used for the operation of nuclear facilities. Due to the considerations for the final disposal of process endproduct, other treatment methods such as adsorption, precipitation using some inorganic materials have been suggested to prepare for large amounts of waste during decommissioning. This study evaluated sintering characteristics for radioactive precipitates generated during the liquid waste treatment process. The volume reduction efficiency and compressive strength of sintered pellets were the major parameters for the evaluation. Major components of a simulated precipitate were some coagulated (oxy) hydroxides containing light elements, such as Si, Al, Mg, Ca, and zeolite particles. Green pellets compressed to around 100 MPa were heated at a range of 750~850°C to synthesize sintered pellets. It was observed that the volume reduction percentages were higher than 50% in the appropriate sintering conditions. The volume reduction was caused by the reduction of void space between particles, which is an evidence of partial glassification and ceramization of the precipitates. This result can also be attributed to conversion reactions of zeolite particles into other minerals. The compressive strength ranged from 6 to 19 MPa. These results also showed a significant correlation with the volume reduction of sintered body. Although our lab-scale experiments showed many benefits of sintering for the precipitates, optimized conditions are needed for large-scale practical applications. Evaluation of sintering characteristics as a function of pellet size and further testing will be conducted in the future.
Various dry active wastes (DAWs) have been accumulated in nuclear power plants since the DAWs are mostly combustible. KAERI has developed a thermochemical treatment process for the used decontamination paper as an operational waste to substitute for incineration process and to decontaminate radionuclides from the DAWs. The thermochemical process is composed of thermal decomposition in a closed vessel, chlorination of carbonated DAWs, separation of soluble chlorides captured in water by hydroxide precipitation, and immobilization of the precipitate. This study examined the third and fourth steps in the process to immobilize Co-60 by fabricating a stable wasteform. Precipitation behaviors were investigated in the chloride solution by adding 10 M KOH. It was shown that the precipitates were composed of Mg(OH)2 and Al(OH)3. Then, the glass-ceramic wasteform for the precipitates were produced by adding additive mixtures in which silica and boron oxide were blended with various ratios. The wasteform was evaluated in terms of volume reduction ratio, bulk density, compressive strength, and leachability.
With the importance of permanent disposal of high-level radioactive waste (HLW) generated in Korea, the deep geological disposal system based on the KBS-3 type is being developed. Since the deep geological repository must provide the long-term isolation of HLW from the surface environment and normal habitats for humans, plants, and animals, it is essential to assess the longterm performance of the disposal facility considering thermal-hydraulic-mechanical-chemical (TH- M-C) evolution. Decay heat dissipated from HLW contained in the canister causes an increase in temperature in the adjacent area. The requirement for the maximum temperature is established in consideration of the possibility of bentonite degradation. Therefore, when designing the repository, the temperature in the region of interest should be identified in detail through the thermal evolution assessment to ensure that the design requirement is satisfied. In the thermal evolution analysis, it is needed to evaluate the temperature distribution over the entire area of the disposal panel to consider the heat generated from both a single canister and adjacent canisters. Computational fluid dynamics (CFD) codes are widely used for detailed temperature analysis but are limited to simulating a wide range. Accordingly, in this study, we developed an analytical solution-based program for efficiently calculating the temperature distribution throughout the deposition panel, which is based on threedimensional heat conduction equations. The code developed can assess the temperature distribution of engineered and natural barrier systems. Principal parameters to be inputted are as follows: (a) geometry of the panel (e.g. width, length, height, spacing between canisters), (b) geometry of the canister (e.g. diameter, height), (c) thermal properties of bentonite and host-rock, (d) initial conditions (e.g. residual heat, temperature), and (e) time information (e.g. canister emplacement rate, time-interval, period). Through the calculation for the conceptual problem of a deposition panel capable of accommodating 900 (i.e. 30×30) canisters, it was confirmed that the program can adequately predict when and where the maximum temperature will occur. It is expected that the overall temperature distribution within the panel can be obtained by the evaluation of the entire region using this program reflecting the detailed design of the repository to be developed in the future. In addition, the thermal evolution analysis considering the influence of other canisters can be performed by applying the results as boundary conditions in the CFD analysis.
꽃노랑총채벌레(Frankliniella occidentalis)는 고추를 가해하는 주요 병해충 가운데 하나이다. 유충과 성충이 긁어빠는 구기로 잎과 열매에 가해하는 직접피해는 물론이고 일명 칼라병이라 일컬어지는 토마토반점위조바 이러스를 전파하는 간접피해를 주고 있다. 다양한 바이러스 내병성 품종이 농가에서 재배되고 있으나, 칼라병의 발병은 해를 거듭하며 증가하고 있다. 놀라운 사실은 일부 내병성 품종에 대해서 총채벌레의 유인력이 감수성 품종에 비해 높다는 사실이다. 본 연구는 꽃노랑총채벌레에 대한 고추의 항객성 기작을 분석하였다. 총채벌레에 이미 피해를 받은 고추는 다른 총채벌레의 접근을 억제하는 것은 물론이고 천적인 미끌애꽃노린재를 유인하였 다. 이 고추 내부에는 자스모닉산 생합성 관여 유전자의 발현이 증가하였다. 고추가 생산하는 향기성분을 SPME 방식으로 모아 분석한 결과 Green leaf volatile과 terpene류의 증가를 보였다. 시판되는 10개의 고추 품종을 대상으 로 항객성 생물 검정과 향기성분 분석을 실시한 결과 이상의 항객성 기작을 뒷받침하였다. 또한 근권세균 가운데 일부는 고추로 하여금 이러한 항객성을 유도하였다.
Background: A breast cancer is the second leading cause of cancer death in women worldwide and among different types of breast cancers, triple-negative breast cancer (TNBC) has a poor prognosis. Methods: We investigated the potential of ginsenoside compound K (CK), an active ingredient in the bio-transformed ginsenoside, to be used as a therapeutic ingredient by examining the effects of CK on cell proliferation, apoptosis, and cancer-related gene expressions in breast cancer cells. Results: From the results of treating MCF-7, an ER and PR-positive breast cancer cells, and MDA-MB-231 (TNBC) with CK at a concentration of 0-100 μM, the half maximal inhibitory concentration (IC50) values for each cell were 52.17 μM and 29.88 μM, respectively. And also, it was confirmed that cell migration was inhibited above the IC50 concentration. In addition, fluorescence analysis of Apoptosis/Necrosis showed that CK induced apoptosis rather than necrosis of breast cancer cells. Through qPCR, it was confirmed that the expression of genes related to apoptosis and cell cycle arrest was increased in CK-treated breast cancer cells, and it acted more effectively on TNBC. However, the expression of genes related to tumor invasion and metastasis is also increased, so it is necessary to consider the timing of application of CK as a potential therapeutic anticancer compound. Conclusions: CK showed a stronger inhibitory effect in TNBC with poor prognosis but considering the high tumor invasion and metastasis-related gene expression, the timing of application of CK should be considered.
Background: This study has mainly focused on finding pharmacological effects of ginsenosides that can reduce the unwanted side effects of the cytotoxic anticancer drugs and are highly effective on prostate cancer, colorectal cancer, liver cancer, hormone-dependent breast cancer, triple-negative breast cancer, and brain cancer (neuroblastoma). Methods: Minor and rare ginsenosides (GS) of Rh2 which have a high absorption ability and excellent pharmacological actions were treated with the 6 different types of cancer cell lines and their anticancer activities were investigated by analyzing gene expressions associated with various cancers through qPCR and other relevant methods. Results: In cancer cells exposed to Rh2, cell viability and cell migration were reduced, and apoptosis was induced. Each cancer cell was divided into three groups according to the cell proliferation response by Rh2; 1) A group in which the cell viability decreases inversely to an increase in Rh2 treatment concentration; 2) A group in which the cell viability rapidly decreases in Rh2 treatment above a certain level of concentration; 3) A group in which the cell viability was not suppressed below 20-30% even with 100 μL of Rh2, the highest concentration used in this study. Conclusions: It was shown that Rh2 has a significant effect on inhibiting the proliferation of prostate cancer cells and hormone-dependent breast cancer cells.
Background: Smartphone addiction has emerged as a significant social problem. Numerous studies have indicated the association between smartphone use and discomfort in the musculoskeletal system of the upper extremities.
Objects: This cross-sectional survey aimed to compare the characteristics of musculoskeletal pain in the neck, trunk, and upper limbs between individuals with smartphone addiction and those without addiction.
Methods: We collected a total of 326 healthy individuals’ data from China and Korea who had owned and used smartphones for more than 5 years between 20–50s through an online questionnaire consisting of 84 questions in four major sections. The first part contained basic information on the participant's personal characteristics and smartphones. The second part contained questions about smartphone use and posture. The third part was the smartphone addiction. The fourth part was to investigate musculoskeletal pain in various upper body parts.
Results: Smartphone addiction has a weak negative correlation with age (r = –0.20, p < 0.01) and a weak positive correlation with the hours of smartphone use (r = 0.376, p < 0.01). Frequent musculoskeletal pain symptoms related to smartphone use were observed in the neck, shoulder, lower back, and wrists. The hours of smartphone use was slightly positively associated with the prevalence of musculoskeletal pain in the shoulder (r = 0.162, p < 0.05) and lower back (r = 0.125, p < 0.05). The prevalence of musculoskeletal pain in the neck (χ2 = 3.993, p < 0.05), shoulder (χ2 = 6.465, p < 0.05), and wrist (χ2 = 4.645, p < 0.05) was significantly higher among females than males.
Conclusion: The results suggest that smartphone addiction should be recognized as a dual concern encompassing both physical health and psychosocial aspects. Furthermore, healthcare professionals, including physicians and physical therapists, should consider clients' smartphone usage patterns when assessing and treating with musculoskeletal pain.