• 지식경영연구
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• 제22권2호
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• pp.209-225
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• 2021

제품수명주기관리(Product Lifecycle Management)는 8개의 지식영역으로 구성된 잘 정의된 관리방법이다. 4차 산업혁명이 스마트 팩토리와 밀접한 관련이 있기 때문에 궁극적으로 제품의 아이디어 생성에서 폐기까지의 전 과정을 효과적으로 관리하는 제품수명주기관리의 중요성이 부각되고 있다. 본 연구는 제품수명주기관리 분야의 전문가를 대상으로 제품수명주기관리의 지식영역의 현재와 향후 적용정도를 4차 산업혁명의 관점에서 분석하였다. 제품수명주기관리의 지식영역이 현장에서 어느 정도 적용되고 있는지를 현재의 관점과 가까운 미래의 관점에서 전문가 인식을 분석하였다. 제품수명주기관리의 지식영역의 현재 및 미래의 적용정도를 분석하고, 적용정도의 관점에서 지식영역 간의 차이가 있는지를 분석하였다. 분석된 결과를 중심으로 그 의미와 향후 흐름을 제시하였다.

• 센서학회지
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• 제30권2호
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• pp.109-113
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• 2021

In this study, an automated culture media replacement system was developed to analyze changes in the contraction characteristics of cardiomyocytes according to the state of the culture media. For the long-term storage of culture media, a Peltier refrigerator with a temperature of 5 to 8℃ was provided and a pH of 7.4 was maintained. The cell culture media of the cardiomyocytes was continuously replaced using interlocking pumps at a flow rate of 0.83 μl/h. The cardiomyocytes in which the culture media was replaced automatically demonstrated lower heartbeats per minute compared to samples in which there was no replacement. However, these cardiomyocytes moved more uniformly and produced greater displacement in one heartbeat cycle. It was observed that the sarcomere length of the cardiomyocytes increased due to the automated culture media replacement system. These cardiomyocytes were found to demonstrate better maturation compared to the control group. The maturation of cardiomyocytes was verified through staining images. The proposed automated culture media replacement system generates a uniform heart rate and improvements in contraction force. Based on the study, patient-specific drug toxicity assessments can be conducted using differentiated cardiomyocytes in induced pluripotent stem cells.

• 박물관보존과학
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• 제27권
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• pp.91-102
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• 2022

철기 문화재 복원에 사용되고 있는 실리카 계열의 무기질 충전제는 열팽창률감소, 흐름성 개선 등의 기능성 부여를 목적으로 사용되고 있다. 그러나 충전제의 양이 많을 수록 복원재의 물성저하 및 황변 현상 촉진의 원인이되며, 결과적으로 재처리로 이어져 유물의 피로도를 상승시키는 결과를 초래한다. 따라서 복원제와 충전제의 혼합 정량화 및 황변성 연구 필요성이 강조될 수 밖에 없다. 이를 보완하기 위해 실리카계 경량 충전제인 Micro Shell을 비교군으로 물성연구를 진행하였다. 실험 결과 기존에 사용하던 충전제에 비해 Micro Shell이 황변도 발생 수치가 최대 34% 낮았으며, 충전제의 배합양에 따라서 공통적으로 접착력과 비중의 물성 수치값이 좋은 것을 확인하였다. 본 연구 결과 Micro Shell의 사용 가능성에 대해 확인하였다.

• Biomolecules & Therapeutics
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• 제30권1호
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• pp.72-79
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• 2022

Licochalcone H (LCH) is a phenolic compound synthetically derived from licochalcone C (LCC) that exerts anticancer activity. In this study, we investigated the anticancer activity of LCH in human skin cancer A375 and A431 cells. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay was used to evaluate the antiproliferative activity of LCH. Cell cycle distribution and the induction of apoptosis were analyzed by flow cytometry. Western blotting assays were performed to detect the levels of proteins involved in cell cycle progression, apoptosis, and the JAK2/STAT3 signaling pathway. LCH inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay revealed that LCH induced apoptosis, and the LCH-induced apoptosis was accompanied by cell cycle arrest in the G1 phase. Western blot analysis showed that the phosphorylation of JAK2 and STAT3 was decreased by treatment with LCH. The inhibition of the JAK2/STAT3 signaling pathway by pharmacological inhibitors against JAK2/STAT3 (cryptotanshinone (CTS) and S3I-201) simulated the antiproliferative effect of LCH suggesting that LCH induced apoptosis by modulating JAK2/STAT3 signaling.

• Tuberculosis and Respiratory Diseases
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• 제85권2호
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• pp.147-154
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• 2022

Background: The expression of calcium signaling pathway molecules is altered in various carcinomas, which are related to the proliferation and altered characteristics of cancer cells. However, changes in calcium signaling in anti-cancer drug-resistant cells (bearing a T790M mutation in epidermal growth factor receptor [EGFR]) remain unclear. Methods: Afatinib-mediated changes in the level of store-operated Ca²⁺ entry (SOCE)-related proteins and intracellular Ca²⁺ level in non-small cell lung cancer cells with T790M mutation in the EGFR gene were analyzed using western blot and ratiometric assays, respectively. Afatinib-mediated autophagic flux was evaluated by measuring the cleavage of LC3B-II. Flow cytometry and cell proliferation assays were conducted to assess cell apoptosis and proliferation. Results: The levels of SOCE-mediating proteins (ORAI calcium release-activated calcium modulator 1 [ORAI1], stromal interaction molecule 1 [STIM1], and sarco/endoplasmic reticulum Ca²⁺ ATPase [SERCA2]) decreased after afatinib treatment in non-small cell lung cancer cells, whereas the levels of SOCE-related proteins did not change in gefitinib-resistant non-small cell lung cancer cells (PC-9/GR; bearing a T790M mutation in EGFR). Notably, the expression level of SOCE-related proteins in PC-9/GR cells was reduced also responding to afatinib in the absence of extracellular Ca²⁺. Moreover, extracellular Ca²⁺ influx through the SOCE was significantly reduced in PC-9 cells pre-treated with afatinib than in the control group. Additionally, afatinib was found to decrease the level of SOCE-related proteins through autophagic degradation, and the proliferation of PC-9GR cells was significantly inhibited by a lack of extracellular Ca²⁺. Conclusion: Extracellular Ca²⁺ plays important role in afatinib-mediated autophagic degradation of SOCE-related proteins in cells with T790M mutation in the EGFR gene and extracellular Ca²⁺ is essential for determining anti-cancer drug efficacy.

• 한방재활의학과학회지
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• 제32권3호
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• pp.29-35
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• 2022

Objectives The purpose of this systematic review is to analyse randomized controlled trials about acupuncture for patellofemoral pain syndrome (PFPS) and evaluate it's pain improvement effect. Methods Studies will be searched from ten databases (Medline/PubMed, Cochrane Library, EMBASE, China National Knowledge Infrastructure [CNKI], WanFang Data, Citation Information by NII [CiNII], ScienceON, Koreanstudies Information Service System [KISS], KMBASE, and KoreaMed). Participants will be patients diagnosed with PFPS, regardless of cause, gender, age or race, and interventions will be acupuncture, electroacupuncture, dry needling, fire needle, and acupotomy. Other treatments than interventions will be the control group and the main outcome will be reviewed by visual analogue scale (VAS). Results Data will be extracted and assessed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis flow chart and Cochrane risk of bias tools. Meta-analysis will be conducted using random effect model within 95% confidence interval. Conclusions We expect this systematic review to provide useful data about the pain improvements of patellofemoral pain using acupuncture and expect to stimulate and systematize acupuncture treatment on PFPS in the future.

• 중환자간호학회지
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• 제15권3호
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• pp.115-127
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• 2022

Purpose : This study aimed to investigate sleep parameters and to identify differences according to respiratory support therapy, sedation, and pain medication in intensive care unit (ICU) patients. Methods : In this observational study, sleep parameters were measured using actigraphy. We observed 45 sleep events in 30 ICU patients receiving respiratory support therapy. We measured the sleep parameters, time, efficiency, and wakefulness after sleep onset (WASO). The differences in sleep parameters according to the respiratory support therapy were analyzed using the Mann-Whitney U test. Results : The average daily sleep time of the participants was 776.66±276.71 minutes, of which more than 60% accounted for daytime sleep. During night sleep, the duration of WASO was 156.93±107.91 minutes, and the frequency of WASO was 26.02±25.82 times. The high flow nasal cannula (HFNC) group had a significantly shorter night sleep time (𝑥²=7.86, p =.049), a greater number of WASO (𝑥²=5.69, p =.128), and a longer WASO duration (𝑥²=8.75, p =.033) than groups of other respiratory therapies. Conclusion : ICU patients on respiratory support therapy experienced sleep disturbances such as disrupted circadian rhythm and sleep fragmentation. Among respiratory support regimens, HFNC was associated with poor sleep parameters, which appears to be associated with the insufficient use of analgesics. The results of this study warrant the development of interventions that can improve sleep in ICU patients receiving respiratory support, including HFNC.

• Geomechanics and Engineering
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• 제30권1호
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• pp.93-105
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• 2022

With the exploitation of natural resources in China, underground resource extraction and underground space development, as well as other engineering activities are increasing, resulting in the creation of many defective rocks. In this paper, uniaxial compression tests were performed on rocks with double holes and fractures at different angles using particle flow code (PFC2D) numerical simulations and laboratory experiments. The failure behavior and mechanical properties of rock samples with holes and fractures at different angles were analyzed. The failure modes of rock with defects at different angles were identified. The fracture propagation and stress evolution characteristics of rock with fractures at different angles were determined. The results reveal that compared to intact rocks, the peak stress, elastic modulus, peak strain, initiation stress, and damage stress of fractured rocks with different fracture angles around holes are lower. As the fracture angle increases, the gap in mechanical properties between the defective rock and the intact rock gradually decreased. In the force chain diagram, the compressive stress concentration range of the combined defect of cracks and holes starts to decrease, and the model is gradually destroyed as the tensile stress range gradually increases. When the peak stress is reached, the acoustic emission energy is highest and the rock undergoes brittle damage. Through a comparative study using laboratory tests, the results of laboratory real rocks and numerical simulation experiments were verified and the macroscopic failure characteristics of the real and simulated rocks were determined to be similar. This study can help us correctly understand the mechanical properties of rocks with defects and provide theoretical guidance for practical rock engineering.

• 한국건설순환자원학회논문집
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• 제10권4호
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• pp.498-505
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• 2022

본 연구에서는 Living Concrete의 품질특성 평가결과 유동성은 황토 혼합율 증가에 따라 테이블 플로우가 감소하는 경향이 나타났으며, 압축강도는 황토 혼합율 증가에 따라 감소하는 것으로 나타났다. 경량화를 위하여 밀도 특성 평가를 실시하였으며, 비교군으로 시멘트를 사용한 패널과 비교한 결과 시멘트 패널의 밀도에 비해 약 20 % 낮은 밀도가 측정되어 하중에 영향을 적게 받아 구조물에 설치가 가능할 것으로 판단된다. 패널온도 저감성을 평가한 결과 시간에 따른 온도 저감의 차이가 나타났으며, 이끼가 착근된 패널이 이끼가 착근되지 않은 패널보다 온도의 저감이 나타나 수직형 녹화시스템에 활용이 가능할 것으로 판단된다.

• Wind and Structures
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• 제35권6호
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• pp.419-430
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• 2022

In wind-resistant designs, wind velocity is assumed to be a Gaussian process; however, local complex topography may result in strong non-Gaussian wind features. This study investigates the non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers by the large eddy simulation (LES) model, and the turbulent inlet of LES is generated by the consistent discretizing random flow generation (CDRFG) method. The performance of LES is validated by two different complex terrains in Changsha and Mianyang, China, and the results are compared with wind tunnel tests and onsite measurements, respectively. Furthermore, the non-Gaussian parameters, such as skewness, kurtosis, probability curves, and gust factors, are analyzed in-depth. The results show that the LES method is in good agreement with both mean and turbulent wind fields from wind tunnel tests and onsite measurements. Wind fields in complex terrain mostly exhibit a left-skewed Gaussian process, and it changes from a softening Gaussian process to a hardening Gaussian process as the height increases. A reduction in the gust factors of about 2.0%-15.0% can be found by taking into account the non-Gaussian features, except for a 4.4% increase near the ground in steep terrain. This study can provide a reference for the assessment of extreme wind loads on structures in complex terrain.