• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.457-462
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• 1995

Unlike the usual bone plate and screw fracture fixation, an improved plate fixation method, which can transfer gradually physiological load to bones, is described. The key feature of the present method is to use washers between the plate and the screw. Bio-absorbable materials or non-ferrous materials with good damping characteristics are used to manufacture the washers. The purpose of this paper is to discuss potential advantages of the proposed method, and to show experimentally its improved impact-absorbing characteristics. Vibration experiments are carried out for pig femurs and cow tibias with and without the proposed washers. This experiments show that the washers can drop the first peak value suite substantially in the FRF plots. Although in-vivo experiments have not been conducted, the present fixation method appears to be a simple and effective alternative to the presently used method.

• Korean Chemical Engineering Research
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• v.44 no.1
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• pp.46-51
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• 2006

As one of the $CO_2$ reduction strategies, a biological method was proposed to convert $CO_2$ to useful biomass with antioxidant carotenoids by photosynthetic microorganisms. One of the photoautotrophs, Haematococcus pluvialis is a freshwater green microalga and accumulates the secondary carotenoid astaxanthin during induction of green vegetative cells to red cyst cells. In this study, $CO_2$ fixation and astaxanthin production using H. pluvialis was conducted by photoautotrophic culture in the $CO_2$ supplemented photo-incubator. Maximum growth rate of H. pluvialis was obtained at a 5％ $CO_2$ environment on basic N and P conditions of NIES-C medium. The photoautotrophic induction consisted of 5％ $CO_2$ supply and high light illumination promoted astaxanthin synthesis in H. pluvialis, yielding an astaxanthin productivity of $9.6mg/L{\cdot}day$ and a $CO_2$ conversion rate of $27.8mg/L{\cdot}day$ to astaxanthin. From the results the sequential photoautotrophic culture and induction process using H. pluvialis is expecting an alternative $CO_2$ reduction technology with a function of valuable biosubstance production.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.181-184
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• 2001

The biological fixation of carbon dioxide using microalgae have many advantages over chemicals and remove carbon dioxide simultaneously. A ketocarotenoid astaxanthin is hyper-accumulated in the green freshwater microalga, Haematococcus pluvialis. In the present study, the combine effects of carbon dioxide concentration and light intensity on the growth of H. pluvilais were investigated. The carbon dioxide concentration above 10% caused a severe inhibition and around 5% is optimal for growth. Adaptation to high concentration of carbon dioxide enhanced the $CO_2$ tolerance. Specific growth rate calculated differently based upon cell number or dry weight because of the distinctive life cycle patterns of H. pluvialis : small-sized motile green cell and thick cell walled red cyst cell. Based on the light dependence of H. pluvialis, internally illuminated air-lift photobioreactor was designed and operated. Gradual increase of light supply gave more active growth and more effective productivity of astaxanthin than constant light supply.

• KSBB Journal
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• v.26 no.6
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• pp.561-564
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• 2011

In this study, we carried out the development of high performance photobioreactor, which can be used to develop the biological $CO_2$ fixation technology as well as the renewable biofuels, the microalgae Botryococcus braunii. When B. Braunii was cultured in Anti-biofouling photobioreator, growth rate of it showed about 3 times higher than that of bubble column photobioreactor at the same conditions. In case of photobioreactor without bead, after 3 days culture time, biofouling occur rapidly in wall of the photobioreactor. However, with bead 5% (V/V), biofouling do not occur all experimental days.

• Journal of Biomedical Engineering Research
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• v.2 no.1
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• pp.21-30
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• 1981

In this study, measuring eye movements with E.O.G. to targets beyond 20$^{\circ}$ from fixation point, results are as follows. (1) When the eyes turn toward targets of more than 20$^{\circ}$ eccentricity, the first saccadic eye movement falls short of the target. The presence of image of the target off the fovea(visual error signal) subsequent to such an undershoot elicits, after short interval, corrective saccadic eye movements(usually one) which place the image of the target on the fovea. (2) There are different programming modes at retina for eye movement to targets within and beyond 20$^{\circ}$ from the fixation point. (3) Saccadic system, preparing the direction and amplitude of eye movement completes the corrective saccadic eye movements. (4) Distribution of latency and intersaccadic interval(I.S.I.)are frequently multi modal, with a seperation between modes of 25[msec]. (5) There are two types of saccadic eye movements for the double-step targets. This fact suggests that the visual information is sampled stochastically. (6) The new model of saccadic system including the dissociation of visual functions dependent on retinal eccentricity is required.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.144-155
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• 1994

마이크로파 에너지로서 현미경 관찰을 위한 생체물질을 고정할 때, 고정효과는 화학 고정액을 사용할 때와 비교하여 보다 우수한 또는 적어도 동일한 고정효과를 볼 수 있다는 것은 알려진 사실이다. 그러나 기존의 마이크로파 오븐을 사용하여 생체물질을 고정하면 고정 정도에 일정성이 없는데, 이는 마이크로파가 균일하게 조사되지 않고 고정에 적절하도록 마이크로팍의 강도를 조절하기 어려우며, 이로 인하여 정확한 고정온도의 측정이 불가능하기 때문으로 생각된다. 이 연구에서는 마이크로파가 조사되는 동안 시료의 온도를 측정할 수 없는 기존의 마이크연.파 오븐의 단점을 보완하기 위하여 비접촉식 적외선 온도 감응기를 장착한 마이크로파 오븐을 개발하였으며 고정효과를 관찰하기 위하여는 포유류의 기준 조직으로 알려진 생쥐의 신장을 고정하였다 고정효과는 전체적인 구조와 세부 구조의 보존이 모두 우수하였고 최적의 고정온도는 28$\pm$1$^{\circ}C$(완충용액 20 ml, 10초) 이었다. 이와같이 고정된 재료는 고정효과 뿐만 아니라 염색성이 좋아서 조직화학 반응이 우수하고, 냉동절편법과 연계했을 때 전체 절편제작 과정이 2~4시간 내에 완료될 수 있었다 이때 절편의 질(질)은 화학 고정액이나 냉동절편 법에 의하여 제작된 것 보다 우수하였다.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.124-128
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• 1998

The procedures currently used for determining microbiological quality of natural mineral water recommend filtration through membrane filters. In this study, we evaluated the effect of vacuum pressure for the accurate detection of bacteria from water samples seeded with Escherichia coli. We observed that the number of E. coli detected increased with increasing vacuum pressure. In order to examine the retention rate of bacteria in the holes of the membranes under the different pressures, the membrane filters were removed after filtration, washed with sterile water by vortexing, and placed on m-Endo agar plates. With all the filters tested, the number of E. coli retained within the filters at negative 600 mmHg was approximately 10 to $20\%$ higher than that obtained with 100 mmHg. These results demonstrate that the vacuum pressure exerted during the filtration procedure may affect the fixation of bacteria into some portions of openings in the membrane filter.

• Molecules and Cells
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• v.23 no.3
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• pp.405-409
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• 2007

A putative type-I chalcone isomerase (CHI) cDNA clone EuNOD-CHI was previously isolated from the root nodule of Elaeagnus umbellata [Kim et al. (2003)]. To see if it encodes a functional CHI, we ectopically overexpressed it in the Arabidopsis (Arabidopsis thaliana) transparent testa 5 (tt5) mutant, which is defective in naringenin production and has yellow seeds due to proanthocyanidin deficiency. Ectopic overexpression of EuNOD-CHI resulted in recovery of normal seed coat color. Naringenin produced by CHI from naringenin chalcone was detected in the transgenic lines like in the wild-type, whereas it was absent from the tt5 mutant. We conclude that EuNOD-CHI encodes a functional type-I CHI. In situ hybridization revealed that EuNOD-CHI expression is localized to the infected cells of the fixation zone in root nodules.

• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.83-89
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• 2008

Study was developed the metallic plate for fixation in the femur fracture and plates has a firm place in fracture treatment. This plates can be stabilized for fracture fixation as well as biological and dynamical device. The device's designation and sizing has a optimization with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. The bending strength of the curved metallic long plate has to evaluate a 11,000N and the bending strength of the curved metallic short plate has to evaluate a 6,525N. This see the X-ray image of bending angle made certain of 15$^{\circ}$ at number 2 and same 82.87$^{\circ}$ at number 2, 4, 5, 7, 8, 9, 10 by outside angle, and confirmed 25.26$^{\circ}$ at number 3, 3.68$^{\circ}$ at number 6, 15.64$^{\circ}$ at number 9 by inside angle. This study shows that keep up the metallic plate for fixation in the femur fracture through X-ray Image and the device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture. Short plate have a wrapping of femur and long plate have to preserve a pole of femur.

• The Journal of the Korean dental association
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• v.55 no.10
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• pp.676-687
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• 2017

Objectives : The aim of this study was to evaluate the effects of a composite of bone substitute and collagen barrier membrane (bone patch) for local ridge augmentation at peri-implant dehiscence defects on the clinical efficacy and positional stability in dogs. Materials and methods : Implant placement and ridge augmentation procedure were performed at surgically created peri-implant dehiscence defects in canine mandible (n=6). Four treatment modalities were randomly applied: i) bone patch group, ii) Guided bone regeneration (GBR) without pin fixation group (bone graft and collagen membrane), iii) GBR with pin fixation group, and iv) negative control group. After 12 weeks, clinical, micro-CT and histological analyses were performed. Results : Histologic analysis showed that bone patch group had similar results to GBR group and GBR with fixation group in terms of new bone formation. Micro-CT analysis revealed similar results to histologic analysis in terms of total volume maintenance. Operating time was shorter in bone patch group compared to GBR group and GBR with fixation groups. Conclusions : GBR using bone patch could simplify the ridge augmentation procedure with reduced operating time and equivalent biological performance compared to the conventional procedure.