• 대한인간공학회지
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• 제33권4호
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• pp.255-265
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• 2014

Objective: The purpose of this study was to evaluate comfort levels of functional and non-functional chairs using subjective comfort rating, interface pressure measurement, muscle activity measurement, and skin temperature measurement. Background: Chairs are used for a prolonged period of time for sitting in many places such as the office, at university, at school, in industry, and so on. Almost all people use chairs in their everyday life. The functional properties of the chair are associated with comfort. Method: The subjective evaluation contains questions regarding chair comfort which can be rated with five point scale. The body-seat interface pressure was measured using a pressure mat system. The symmetry of sitting was measured using electromyography. The change in body part (thigh and buttock) temperature before and after sitting on a chair was measured with an infrared camera. Results: Participants rated significantly (p < 0.05) higher comfort scores for the functional chair in relation to the buttock and thigh region. Also, the participants felt a better cushion effect in the functional chair. When using the functional chair, lower interface pressure, better thermal comfort, and better symmetry of erector spinae muscle activity were observed. Conclusion: Overall, interface pressure measurement, muscle activity measurement, thermal imaging and subjective comfort score results showed that the functional chair was more comfortable than the non-functional chair. Application: The adopted methodologies could be used to measure the seating comfort of train seats.

• Asian Pacific Journal of Cancer Prevention
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• 제17권11호
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• pp.4857-4861
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• 2016

Background: Imatinib mesylate, a tyrosine kinase inhibitor specifically targeting the BCR/ABL fusion protein, induces hematological remission in patients with chronic myeloid leukemia (CML). However, the majority of CML patients treated with imatinib develop resistance with prolonged therapy. Dendrophthoe pentandra (L.) Miq. is a Malaysian mistletoe species that has been used as a traditional treatment for several ailments such as smallpox, ulcers, and cancers. Methods: We developed a resistant cell line (designated as K562R) by long-term co-culture of a BCR/ABL positive CML cell line, K562, with imatinib mesylate. We then investigated the anti-proliferative effects of D. pentandra methanol extract on parental K562 and resistant K562R cells. Trypan blue exclusion assays were performed to determine the IC50 concentration; apoptosis and cell cycle analysis were conducted by flow cytometry. Results: D. pentandra extract had greater anti-proliferative effects towards K562R ($IC50=192{\mu}g/mL$) compared to K562 ($500{\mu}g/mL$) cells. Upon treatment with D. pentandra extract at the IC50. concentration: K562 but not K562R demonstrated increase in apoptosis and cell cycle arrest in the G2/M phase. Conclusion: D. pentandra methanol extract exerts potent anti-proliferative effect on BCR/ABL positive K562 cells.

• Macromolecular Research
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• 제17권11호
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• pp.850-855
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• 2009

Keratin is an important protein used in wound healing and tissue recovery. In this study, keratin was modified chemically with iodoacetic acid (IAA) to enhance its solubility in organic solvent. Poly(hydroxybutylate-co-hydroxyvalerate) (PHBV) and modified keratin were dissolved in hexafluoroisopropanol (HFIP) and electrospun to produce nanofibrous mats. The resulting mats were surface-characterized by ATR-FTIR, field-emission scanning electron microscopy (FE-SEM) and electron spectroscopy for chemical analysis (ESCA). The pure m-keratin mat was cross-linked with glutaraldehyde vapor to make it insoluble in water. The biodegradation test in vitro showed that the mats could be biodegraded by PHB depolymerase and trypsin aqueous solution. The results of the cell adhesion experiment showed that the NIH 3T3 cells adhered more to the PHBV/m-keratin nanofibrous mats than the PHBV film. The BrdU assay showed that the keratin and PHBV/m-keratin nanofibrous mats could accelerate the proliferation of fibroblast cells compared to the PHBV nanofibrous mats.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.216-233
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• 2021

In this work, Rhizophora spp. particleboard phantoms were made using SPI-based adhesives, modified with sodium hydroxide and itaconic acid polyamidoamine-epichlorohydrin (0, 5, 10, and 15 wt%). An X-ray computed tomography (CT) imaging system was used to ascertain the CT numbers and density distribution profiles of the particleboards. The SPI-based/NaOH/IA-PAE/Rhizophora spp. particleboard phantoms with 15 wt% IA-PAE addition level had the highest solid content, flexural strength, flexural modulus, and internal bonding strength of 36.06 ± 1.08%, 18.61 ± 0.38 Nmm^-2, 7605.76 ± 0.89 Nmm^-2, and 0.463 ± 0.053 Nmm^-2, respectively. The moisture content, mass density, water absorption, and dimensional stability were 6.93 ± 0.27%, 0.962 ± 0.037 gcm^-3, 22.36 ± 2.47%, and 10.90 ± 0.86%, respectively. The results revealed that the mass attenuation coefficients and effective atomic number values within the 16.59-25.26 keV photon energy region, were close to the calculated XCOM values in water, with a p-value of 0.077. Moreover, the CT images showed that the dissimilarities in the discrepancy of the profile density decreased as the IA-PAE concentrations increased. Therefore, these results support the appropriateness of the SPI-based/NaOH/IA-PAE/Rhizophora spp. particleboard with 15 wt% IA-PAE adhesive as a suitable tissue-equivalent phantom material for medical health applications.

• 한국의학물리학회지:의학물리
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• 제33권4호
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• pp.121-128
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• 2022

Purpose: This study evaluated the quality of plans based on magnetic resonance-guided radiotherapy (MRgRT) tri-Co-60, linac, and conventional linac-based volumetric modulated arc therapy (linac-VMAT) for prostate cancer. Methods: Twenty patients suffering from prostate cancer with intermediate risk who were treated by MAT were selected. Additional treatment plans (primary and boost plans) were generated based on MRgRT-tri-Co-60 and MRgRT-linac. The planning target volume (PTV) of MRgRT-based plans was created by adding a 3 mm margin from the clinical target volume (CTV) due to high soft-tissue contrast and real-time motion imaging. On the other hand, the PTV of conventional linac was generated based on a 1 cm margin from CTV. The targets of primary and boost plans were prostate plus seminal vesicle and prostate only, respectively. All plans were normalized to cover 95% of the target volume by 100% of the prescribed dose. Dosimetric characteristics were evaluated for each of the primary, boost, and sum plans. Results: For target coverage and conformity, the three plans showed similar results. In the sum plans, the average value of V_65Gy of the rectum of MRgRT-linac (2.62%±2.21%) was smaller than those of MRgRT tri-Co-60 (9.04%±3.01%) and linac-VMAT (9.73%±7.14%) (P<0.001). In the case of bladder, the average value of V_65Gy of MRgRT-linac was also smaller. Conclusions: In terms of organs at risk sparing, MRgRT-linac shows the best value while maintaining comparable target coverage among the three plans.

• Journal of Genetic Medicine
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• 제7권2호
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• pp.156-159
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• 2010

염색체의 역위는 균형재배열을 나타내는 구조적 이상 중 하나로 대부분 정상표현형을 나타낸다. 그러나 생식 세포의 감수 분열 단계에서 역위 고리를 만들어 염색체의 결실 또는 중복을 보이는 재조합 염색체가 형성되면 자녀에게 비정상 표현형이 나타나게 된다. 본 증례는 균형전좌를 가진 산모와 그 태아에 대한 정확한 핵형분석을 위해 세포유전학적인 방법과 분자유전학적인 방법을 함께 이용한 증례 보고이다. Trypsin과 Giemsa를 이용한 GTG 분염법의 결과에서 태아는 산모와는 다른 형태의 구조적 이상이 나타났으며, 정확한 분석을 위해 MLPA와 FISH를 시행하였다. 그 결과역위를 보인 9번 염색체 단완 말단 부위의 부분 소실과 13번 염색체에서는 장완 말단 부위의 부분 증폭이 확인되었다. 이는 생식세포의 감수분열시 상동염색체 사이의 교차에 의한 결과로써 드문 재조합 염색체로 판단된다. 따라서 이 태아의 최종 염색체 분석 결과는 46,XY,rec(9)t(9;13)(p22;q32)inv(9)(p12q13)mat로 보고 하였다. 세포유전학적인 방법을 기초로 한 FISH 또는 MLPA 등과 같은 분자유전학적 방법의 적극적인 이용은 복잡한 염색체 이상을 보이는 핵형 분석에 있어서 유용하고 효과적인 방법이라 하겠다.

• 생명과학회지
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• 제20권11호
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• pp.1738-1741
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• 2010

기존의 동물모델에서 암의 성장은 caliper를 이용하여 고형암 부피를 측정으로써 조사하였으나, 암 조직 속의괴사와 부종으로 인하여 부피측정에 신뢰성이 결여 되어 있다. 이러한 문제점을 해결하기 위해 발광 암세포를 이용하여 광학생체영상적으로 분석하는 방법이 개발 되었다. 본 연구에서는 전립선 발광 암세포를 제조하여 고형암 동물모델에서 B16 발광 암세포와 암 성장을 비교 측정하여 신규발광 암세포를 평가하였다. In vitro에서 세포 수와 발광강도는 높은 상관관계를 보였고($R^2$=0.99), 고형암 동물모델에서 암 성장 측정은 괴사에 의한 오차를 줄였다. 이러한 발광신호를 기반으로 한 측정방법은 caliper의 부피 측정에 비하여 높은 항암효과를 보임으로써 기존의 발광 암세포보다 신규 발광전립선 암세포의 유용성을 증명하였다.

• 대한의용생체공학회:의공학회지
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• 제41권2호
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• pp.84-93
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• 2020

Despite of a lot of studies about proprioception tests, there are little study results to investigate the relationship between the functional movement and proprioception level. In this study, we tried to perform quantitative analysis for the effect of ankle joint proprioception level on the one leg standing postural control ability. Nine healthy people volunteered for this study. Force and position aspects of proprioception were evaluated using the electromyography system (EMG) and mobile clinometer application, respectively. The center of pressure (COP) trajectories, measured by a pressure mat sensor, were used for quantitative analysis of balance for each subject. We computed indices and errors of force and position aspects of proprioception from the EMG and ankle angle. Mean velocity of total and anterior-posterior direction (Vm and Vm_ap), root mean squared distance in anterior-posterior direction (RDap), travel length (L), and area (A) of COP trajectories were also calculated as indices of postural control ability of subjects. Two aspects of proprioception showed the low correlation from each other as previous studies. However, the EMG error of gastrocnemius lateral activation showed a high correlation coefficient with COP variables such as Vm (ρ=0.817, p=0.007), Vm_ap (ρ=0.883, p=0.002), RDap (ρ=0.854, p=0.003), L (ρ=0.817, 0.007) and A (ρ=0.700, p=0.036). Within our knowledge, this is almost the first study that investigated the relationship between proprioception level and functional movement. These study results could support that the ankle joint proprioception facilitation exercise would have positive effects on functional balance rehabilitation interventions.

• 한국운동역학회지
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• 제25권1호
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• pp.95-101
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• 2015

Objective : The purpose of this study was to analyze the effects of multisensory exercise on foot pressure sensitivity and balance for the elderly. Method : The subjects were 17 elderly women (11 for the experimental group and 6 for the control group) with a mean age of 83. The subjects all lived in senior residence centers in Seoul. Multisensory exercise was done twice a week for 40 minutes during a 12 week period. Exercise programs were changed every 3 weeks according to the principal of gradual progress of the exercise. In order to train the vision system subjects were asked to open and close their eyes during exercise. When it came to training the vestibular system, subjects stood and walked on high elastic mats with their bare feet. For the somatasensory system subjects always stood and walked with their bare feet. The sub-Metatarsal Pad Elasticity Acquisition Instrument (MPEAI) was used to measure foot pressure sensitivity. MFT Balance test (V1.7) was used to measure anterior / posterior and medial / lateral directional balance. For the statistical analysis the IBM SPSS 21.0 was used to perform Repeatde measured ANOVA and Wilcoxon ranked test. Results : For the multisensory exercise group Hallux (after 6 weeks, 12 weeks), heel (after 6 weeks) and 2nd Metartarsal $40^{\circ}$ (after 6 weeks) pressure sensitivity increased statistically, but the control group didn't change. Also, balance didn't change for the experimental and control group statistically. Conclusion : Exercise with bare feet on a high elastic mat had a partially positive effect on foot sensitivity.

• 대한물리의학회지
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• 제14권4호
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• pp.19-27
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• 2019

PURPOSE: This study examined which stretching exercise had the most positive effect on increasing the range of motion (ROM) of the knee joint in healthy people and whether there was a difference between continuous stretching and intermittent stretching. METHODS: This study included 30 healthy university students from OOO University. The subjects were asked to sit on a mat and perform hamstring-stretching exercise during which the ROM and muscle tone were measured with pre and post-tests. Each subject was assigned randomly to a continuous stretching group (stretching without relaxation time group, n=10, G1) or intermittent stretching group (stretching with 10s relaxing time group, n=10, G2; and stretching with 20s relaxing time group, n=10, G3). The participants conducted hamstring stretching exercises with a sit-and-reach box at three different rest times (0s, 10s, and 20s). Subsequently, they underwent passive knee extension (PKE) tests, in which the ROM of the knee joint was measured with a goniometer, and the muscle tone was evaluated using a MyotonPro. RESULTS: Significant differences in muscle tone, stiffness, and ROM were observed between pre-test and post-test in each groups (p<.05). Although the post hoc tests indicated no significant differences in muscle tone and ROM between the continuous stretching group and intermittent stretching group (p>.05), the rate of change of the ROM showed that the intermittent stretching group developed more effective maintenance of the hamstring flexibility. CONCLUSION: No significant differences in the muscle tone of the hamstring and ROM of the knee joint were observed according to the hamstring stretching exercises with three different rest times. On the other hand, the rate of change of the ROM showed that intermittent stretching maintained the hamstring flexibility more effectively.