3D 프린팅 기술을 활용한 낙상충격 보호패드 구조설계 및 필라멘트 소재에 따른 특성 비교

박정현,정희경,이정란,Park, Jung Hyun,Jung, Hee-Kyeong,Lee, Jeong Ran 한국의류학회 2017 한국의류학회지 Vol.41 No.5

This study uses 3D printing technology to design and fabricate a fall impact protection pad with a spacer fabric structure. The design of the pads consists of hexagonal three-dimensional units connected in a honey-comb shape; in addition, the unit consists of a surface layer and a spacer layer. Protect pads were designed as either a hexagonal type or diamond type according to the surface layer structure; subsequently, a spacer filament was also designed as the most basic I-shape type. Designed pads were printed using four types of flexible filaments to select suitable material for a fall impact protection pad. Impact protection performance and bending stiffness were evaluated for the eight type of pad outputs. As a result of the impact protection performance evaluation, when the force of 6,500N was applied, the force passed through the pad was in the range of 1,370-2,132N. FlexSolid$^{(R)}$ and Skinflex$^{TM}$ showed good protection performance and cubicon flexible filament showed the lowest protection. NinjaFlex$^{(R)}$ was found to be the most flexible in the bending stiffness evaluation.

The effects of saline soaking on the removal torque of titanium implants in rabbit tibia after 10 days

박정현,조성암,Park, Jung-Hyun,Cho, Sung-Am The Korean Academy of Prosthodonitics 2019 대한치과보철학회지 Vol.57 No.4

목적: 0.9% NaCl solution 에 2주간 담근 레이저 처리 임플란트 표면의 친수성 증가현상을 확인하고 그것이 각 임플란트의 초기 치유기간 10일 후에 임플란트의 회전 제거력에 미치는 영향을 확인하고자 한다. 재료 및 방법: 지름 3 mm, 길이 8 mm 되는 10개의 선반 가공된 티타늄 임플란트를 대조군은 레이저 처리하고, 다른 실험군 10개는 레이저 처리 후 2주간 0.9% 생리적 식염수에 담근 후 뉴질랜드산 흰 토끼의 경골에 식립한후, 10일 후에 각각 회전 제거력을 측정하였다. 각 시편의 젖음각과 표면조성 및 형태를 분석하였다. 결과: 10일 후에 실험군의 회전 제거력이 대조군보다 의미있는 증가세를 보였다 (P = .002, < .05). 주사전자 현미경 성분분석과, 형태는 별다른 차이를 보이지 않았다. 결론: 식염수에 담그는 과정은 의미있는 회전 제거력의 증진을 초기기간(10일 후)에 나타낼 수 있다. Purpose: The aim of this study was to confirm if Laser-treated implants were soaked in 0.9% NaCl solution for 2 weeks could increase the surface hydrophilicity, and the Remoal Torque of each implant that inserted in rabbit tibia for initial healing period of 10 days. Materials and methods: Twenty machined titanium surface screws were produced with a diameter 3 mm, length 8 mm. Ten screws had their surface treated with a laser only (laser treated group), and the other 10 were soaked in saline for 2 weeks after surface treatment with a laser (laser treated + saline soaked group). Implants were inserted in rabbit tibia (ten adult New Zealand white rabbits), and the RTQ of each implant was measured after 10 days. The wettability among implants was compared by measuring the contact angle. Surface composition and surface topography were analyzed. Results: After 10 days, the laser treat + soaking group implants had a significantly higher mean RTQ than the laser treated implants (P = .002, < .05). There were no significant morphological differences between groups, and no remarkable differences were found between the two groups in the SEM analysis. Conclusion: Saline soaking implants is expected to produce excellent RTQ and surface analysis results.

Application of Fluorescence Polarization Immunoassay for the Screening of Ochratoxin A in Unpolished Rice

박정현,정덕화,이인선,Park, Jung-Hyun,Chung, Duck-Hwa,Lee, In-Seon Korean Society of Life Science 2006 생명과학회지 Vol.16 No.6

To High Throughput Screening (HTS), a homogeneous fluorescence polarization immunoassay (FPIA) was developed for the quantitative determination of ochratoxin A(OTA) using a $Victor^3$ (PerkinElmer). The homologous tracer, fluorescein-labelled OTA-EDF were synthesized and a specific OTA antibody has been used in the development of the method. It allowed the determination of OTA in the concentration range 0.5-200 ng/ml, with the detection limit of 0.3 ng/ml. The method developed was highly specific and reproducible. OTA spikes in unpolished rice extracts were determinable by FPIA with good recovery. For naturally contaminated unpolished rice samples some disagreement was observed between the results obtained by FPIA and HPLC, which could be related to the a little matrix effect observed for FPIA. Further research is needed to validate the procedure. On the basis of these initial results, this FPIA appears to meet the performance criteria for OTA screening of food samples without a complicated clean-up. 식품안전에 대한 관심이 증가되고 있는 현재, 생물학적 화학적 위해요소로 분류되고 있고, 현재 많은 나라에서 규제치를 설정하고 있는 곰팡이 독소인 ochratoxin A(OTA)에 대한 정량적 측정이 가능한 고속검색법을 개발 하고자 단클론성 항체를 이용하여, 측정시 분리과정이 필요 없는 형광편광면역분석법(FPIA)을 개발하고 최적화 시켰다. 동일구조를 가지는 형광물질 표식자인 OTA-EDF를 합성하여 OTA에 대한 특이항체와 경쟁반응을 시켜 나타나는 형광-편광도(mP)의 변화를 측정하였다. 이는 면역분석법의 특이성과 민감성을 충분히 만족하였다. OTA의 검출범위는 0.5-200 ng/ml였고, 검출한계는 0.3 ng/ml였다. 개발된 분석법은 다른 곰팡이 독소들과의 교차반응은 없었고 높은 특이성과 재현성 및 회수율을 나타내었다. HPLC 방법에 의한 회수율은 88-84%로 다소낮게, FPlA법의 회수율은 90-110%로 다소 높게 나타났다. 16점의 현미시료를 분석하였을 때, 2점이 상관관계가 높게 12-20 ppb 정도 오염된 것으로 나타났다. 4점은 FPIA 및 HPLC 모두에서 음성으로 판정되었다. 개발된 FPIA는 복잡한 전처리 방법이 필요 없는 신속한 검색이 가능하므로, 식품 및 환경에서의 OTA 잔류 검사에 유용하게 사용될 수 있을 것이다.

PSZ, Al₂O₃, TiO₂를 반응소결하여 제조한 쾌삭(快削) 세라믹스

박정현,정동식,이원재,김일수,Park, Jeong Hyun,Jung, Dong Sik,Lee, Won Jae,Kim, Il Soo 한국세라믹학회 2012 한국세라믹학회지 Vol.49 No.6

Machinability is important in engineering applications, especially in the current micro-electronics industry. Most ceramic components have complex shapes and hence require machining generally with diamond tools, which incurs a high production cost. Recently, h-BN-containing machinable ceramics have been developed, but these materials are very expensive due to the high raw materials and production costs. Therefore, the development of low-cost machinable ceramics is necessary. In this study, inexpensive $Al_2TiO_5$ was studied as a replacement for h-BN. $Al_2O_3$, $TiO_2$ and partially stabilized $ZrO_2$(PSZ) powders were mixed with various mole ratios and were sintered at $1500^{\circ}C$ for 1 h. The density, hardness and strength were then measured. The phase analysis and microstructures were observed by XRD and SEM, respectively. The machinability of each specimen was tested by micro-hole machining. The results of this research showed that the produced composites could be used as low-cost machinable ceramics.

학동기이전 소아 안와골절 환자의 임상양상과 예후

박정현,김대현,Jung Hyun Park,Dae Hyun Kim 대한안과학회 2011 대한안과학회지 Vol.52 No.12

Purpose: To evaluate the clinical aspects associated with the preoperative and postoperative state of blow-out fractures in preschool children. Methods: The authors of the present study retrospectively reviewed 11 cases of blow-out fracture repaired by orbital reconstruction. Results: The most common cause of fracture was a traffic accident (45%); there were 7 cases (63%) of inferior wall fracture and 7 cases (63%) of trapdoor-type fracture. All patients with trapdoor-type fractures had nausea and vomiting. After the operation, the majority of patients (88%) had mild ocular motility restriction and diplopia. Conclusions: In preschool children, systemic symptoms such as nausea and vomiting presented frequently. In addition, complications such as restriction in ocular movement and diplopia often developed postoperatively. J Korean Ophthalmol Soc 2011;52(12):1490-1495

노년 여성을 위한 낙상충격 보호팬츠의 착의평가

박정현,이정란,Park, Jung Hyun,Lee, Jeong Ran 한국의류학회 2017 한국의류학회지 Vol.41 No.4

This study conducted a wearing evaluation of fall impact protective clothing developed in the previous study that evaluated activity, appearance, and practicality for elderly women. A total of 6 kinds of pants, which consisted of the three kinds of pads and two kinds of designs, were evaluated and the results are as follows. First, the activity of the protective clothing was tested with six women in their 60's and scored highly in most criterions that indicated satisfactory activity. The honeycomb type pad was superior in four of ten criterions for the activity evaluation results by pad types. Design B without a knee pad was evaluated as more comfortable on two motions that put pressure on the knee area. Second, the expert group considered design A to be better than design B, while the subject group preferred design B over design A in design appearance evaluation. Both the subject group and expert group evaluated that design A is better than design B in consideration of pads. Third, in the assessment of practicability, both the expert group and the subject group provided the highest score on the question of if elderly women needed protective clothing. The evaluation of washing ability indicated no noticeable change in the clothing form and size before and after washing.

백서(白鼠)의 B16-F10 Melanoma에 대한 한련초약침(旱蓮草藥鍼)의 항암(抗癌) 및 면역증강효과(免疫增强效果)

박정현,김영일,홍권의,임윤경,이현,이병렬,Park, Jung-hyeun,Kim, Young-il,Hong, Kwon-eui,Yim, Yun-kyoung,Lee, Hyun,Lee, Byung-ryul 대한침구의학회 2004 대한침구의학회지 Vol.21 No.6

Objective & Methods : To study the effects of anti-cancer, anti-metastasis and immune response improvement of herbal-acupuncture with Eclipta prostrata diffusae herba infusion solution(ELP-HAS), we injected ELP-HAS into Chung-wan(CV12) of C57BL/6 mice implanted intravenously with B16-F10 melanoma. We have reached the following conclusion through the effect on the percentage of $CD25^+/CD4^+$, $CD8^+/CD3e^+$, $CD69^+/B220^+$, $NK1.1^+/CD3e^+$cells in mouse PBMCs, the effect on the pulmonary colony formation number, and the effect on MST(Median Survival Time) and ILS(Increase of Life Span) of C57BL/6 mice implanted intravenously with B16-F10 melanoma. Results : The results were obtained as follows : 1. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the spleen cell proliferation in BALB/c mouse was significantly increased compared with control group. 2. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the percentage of $CD25^+/CD4^+$, $CD8^+/CD3e^+$, $CD69^+/B220^+$, $NK1.1^+/CD3e^+$cells in C57BL/6 mouse PBMCs was increased compared with control group. 3. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, the pulmonary colony formation number of C57BL/6 mice implanted intravenously with B16-F10 melanoma was decreased significantly compared with control group. 4. In the experiment groups treated with ELP(Ecliptae Herba) Herbal acupuncture, MST(Median Survival Time) and ILS(Increase of Life Span) of C57BL/6 mice implanted intravenously with B16-F10 melanoma were increased significantly compared with control group. Conclusions : ELP Herbal acupuncture injection into Chung-wan(CV12) of C57BL/6 mice is considered to be effective in anti-cancer, anti-metastasis and immune response improvement.

임플란트 완성 환자의 구강건강관련 삶의 질과 관련 요인

박정현,엄상화,권현숙,조갑숙,허승주,이소영,유병철,Park, Jung-Hyun,Urm, Sang-Hwa,Kwun, Hyeon-Sook,Cho, Gab-Suk,Heo, Seung-Ju,Lee, So-Young,Yu, Byeng-Chul 한국치위생학회 2011 한국치위생학회지 Vol.10 No.2

Objectives : This study was purposed to estimate the level of oral health quality of life and the relationship between health-related factors and oral health quality of life in patients with successful dental implants. Methods : This questionnaire survey was conducted during the period from December 2009 to March 2010 with 126 patients confirmed successful dental implants in Busan. The oral health related quality of life and oral health-related factors were estimated with OHIP-14 and 8 oral health characteristics, respectively. Data analysis was performed with descriptive analysis, t-test, ANOVA, multiple regression analysis using SAS(ver 9.1) program. Results : The score of oral health quality of life in patients with successful dental implants was $12.25{\pm}7.82$. The scores of subscale of the oral health quality of life were $1.24{\pm}1.35$ in social disability, $1.60{\pm}1.37$ in handicap, $1.60{\pm}1.44$ in psychological disability, $1.70{\pm}1.38$ in functional limitation, $1.81{\pm}1.35$ in physical disability, $2.14{\pm}1.46$ in physical pain, $2.17{\pm}1.46$ in psychological discomfort, respectively. The related factors of oral health quality of life in patients with successful dental implants were absence of other type prosthesis and experience of tooth brushing education. Conclusions : The oral health related quality of life in patients with successful dental implants was relatively good condition. Social supports and chances for high quality denture and tooth brushing educations are needed to improve oral health related quality of life in patients with dental implants.

Stem Cell Based Strategies for the Treatment of Degenerative Retinal Diseases

박정현,구승엽,조명수,이학섭,최영민,문신용,유형곤,Park, Jung-Hyun,Ku, Seung-Yup,Cho, Myung-Soo,Lee, Hak-Sup,Choi, Young-Min,Moon, Shin-Yong,Yu, Hyeong-Gon The Korean Society for Reproductive Medicine 2010 Clinical and Experimental Reproductive Medicine Vol.37 No.3

망막 질환에서의 줄기세포 치료는 이전까지 치료가 불가능하다고 여겨졌던 환자들에서 시력을 향상시킬 수 있는 가능성 때문에 주목 받고 있다. 본문에서는 망막 전구세포의 분화를 위해 사용되는 태아 줄기세포, 배아줄기세포 및 성체줄기세포 등 다양한 세포 종류와, 내인적, 외인적 인자 및 이식 방법에 대해 논의하였다. 망막색소상피세포뿐만 아니라 시각세포 전구체로 성공적으로 분화시킨 실험적 연구가 보고되고 있다. 줄기세포기반치료는 아직 한계가 있지만 망막 질환 환자에서 시력을 회복하기 위한 보다 근본적인 치료 방법으로 기대되고 있다. Stem-cell therapy has the potential to improve vision in patients with untreatable retinal disease. Various types of cell source including fetal, embryonic and adult stem cells, intrinsic and extrinsic factors for differentiation into retinal progenitors and transplantation mode were discussed in this review. Experimental approaches have successfully induced photoreceptor precursor cells and retinal pigment epithelium. Stem-cell-based therapy is a promising treatment to restore vision in patients with retinal disease, in spite of the challenges.

케미컬 라이트에 의한 각결막 화상 1예

박정현,송낭희,지남철,고재웅,Jung Hyun Park,MD,Nang Hee Song,MD,Nam Chul Chi,MD,PhD,Jae Woong Koh,MD,PhD 대한안과학회 2010 대한안과학회지 Vol.51 No.9

Purpose: Chemical lights, also called Luminous Sticks, consist of a solution of diphenyl oxalate (C14H10O4) and hydrogen peroxide (H2O2). Human tissue can be damaged when the mixed solution contacts the human body. The authors report a single case of chemical injury of keratoconjunctiva by exposure to chemical lights. Case summary: A 47-year-old man’s right eye accidentally contacted the fluorescent material when breaking a Luminous Stick 7 days before being referred to our clinic. He had pain in the right eye and experienced visual loss. The patient’s best corrected visual acuity in the right eye was 20/50. An ulcerative lesion with edema at the inferior bulbar and palpebral conjunctiva and coneal epithelial defect was observed upon biomicroscopic examination. The patient was hospitalized and antibiotics, steroids, mydriatic and artificial tear eye drops were applied for treatment. After 9 days of treatment, the best corrected visual acuity of the patient recovered to 20/20, and the conjunctiva and cornea were mostly healed. No complication was observed. Conclusions: Chemical lights are commonly used in concerts and festivals. If the contents contact the eyes when breaking the chemical lights, various chemical burns can occur and cause ophthalmologic complications. Since no regulations have been passed regarding chemical lights, safety education and supervision are considered to be necessary for children. J Korean Ophthalmol Soc 2010;51(9):1282-1286