• KSBB Journal
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• 제15권1호
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• pp.55-59
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• 2000

생난황으로부터 시알산 함유 올리고당을 직접 생산하기 위한 biphasic system(water-immiscible hexane system)의 최적 조건을 조사하였다. Biphasic system I은 II보다 생산수율이 높았으며, 온도, 함수율 및 반응 시간의 최적조건은 각각 $30^{\circ}C$, 20%, 12시간이었다. Biphasic system I 에서, 난황을 가수분해하기 위한 3종류의 효소(protease A, corolase 7089, neutrase 0.5L)의 활성은 함수율과 온도에 강하게 영향을 받았으나, biphasic system II에서는 온도($30^{\circ}C$와 $50^{\circ}C$)의 영향을 거의 받지 않았다. 두 종류의 biphasic system에서 반응시간 12시간까지는 시알산 함유 올리고당의 생산량이 증가되었으나, 15시간 이후에는 거의 증가하지 않았다.

• The Korean Journal of Physiology and Pharmacology
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• 제27권6호
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• pp.541-553
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• 2023

Retinal prostheses have shown some clinical success in restoring vision in patients with retinitis pigmentosa. However, the post-implantation visual acuity does not exceed that of legal blindness. The reason for the poor visual acuity might be that (1) degenerate retinal ganglion cells (RGCs) are less responsive to electrical stimulation than normal RGCs, and (2) electrically-evoked RGC spikes show a more widespread not focal response. The single-biphasic pulse electrical stimulation, commonly used in artificial vision, has limitations in addressing these issues. In this study, we propose the benefit of multiple consecutive-biphasic pulse stimulation. We used C57BL/6J mice and C3H/HeJ (rd1) mice for the normal retina and retinal degeneration model. An 8 × 8 multi-electrode array was used to record electrically-evoked RGC spikes. We compared RGC responses when increasing the amplitude of a single biphasic pulse versus increasing the number of consecutive biphasic pulses at the same stimulus charge. Increasing the amplitude of a single biphasic pulse induced more RGC spike firing while the spatial resolution of RGC populations decreased. For multiple consecutive-biphasic pulse stimulation, RGC firing increased as the number of pulses increased, and the spatial resolution of RGC populations was well preserved even up to 5 pulses. Multiple consecutive-biphasic pulse stimulation using two or three pulses in degenerate retinas induced as much RGC spike firing as in normal retinas. These findings suggest that the newly proposed multiple consecutive-biphasic pulse stimulation can improve the visual acuity in prosthesis-implanted patients.

• 대한의용생체공학회:의공학회지
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• 제45권4호
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• pp.173-178
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• 2024

We present an improved biphasic electrical nerve stimulator designed to overcome limitations. Traditional electrical nerve stimulators lacking a microcontroller unit (MCU) have restrictions in terms of frequency, pulse duration, and amplitude control, making them insufficient for medical applications requiring a broader range of pulse specifications. To address this, we developed a stimulator with enhanced capabilities. By not using an MCU, the design reduces power consumption and the required area, simplifying the overall design and increasing efficiency. In addition, our approach optimizes oscillator parameters to achieve wide frequency and pulse duration ranges. Specifically, we expanded the frequency range of the stimulator up to from 1 mHz to 100 kHz and the pulse duration up to from 5 ㎲ to 500 s. Improved amplitude control mechanisms were implemented for adjustable and high biphasic amplitudes. Furthermore, we added a balancing circuit to ensure proper discharging for tissue safety when biphasic pulses do not occur. The improved stimulator demonstrated an increase in operational range compared to traditional MCU-less designs, producing consistent biphasic pulses with adjustable amplitude and duration. The balancing circuit effectively managed discharging, reducing the risk of tissue damage and ensuring safety and efficacy.

• 한국식품과학회지
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• 제33권1호
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• pp.66-71
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• 2001

가열에 의한 품종별 고구마 조직의 변화에 대한 반응속도론적 상수를 biphasic model과 fractional conversion method를 사용하여 결정하였다. Biphasic model에 따라 고구마의 가열에 의한 조직의 변화는 2단계의 연속적인 1차 반응식으로 표시할 수 있었으며, 활성화에너지는 고구마의 품종에 따라 $71.0{\sim}75.1\;kJ/mol$ 및 $48.4{\sim}59.6\;kJ/mol$이었다. 또한 고구마의 가열에 의한 조직변화를 fractional conversion method를 사용하여 1개의 1차 반응식으로 표시할 수 있었는데, 이 때의 활성화에너지는 $67.5{\sim}75.3\;kJ/mol$로서 biphasic model에 의한 제 1단계의 반응에 대한 값과 유사한 값을 나타냈다. 이들 방법으로 결정된 반응속도론적 상수들 사이에는 kinetic compensation 효과가 있었으며, 두 방법 모두 고구마의 가열에 의한 조직변화에 대한 반응속도론적 상수들을 결정하는데 적용할 수 있음을 알 수 있었다.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.171-178
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• 2008

Purpose: The aim of this study was to evaluated biphasic calcium phosphate applied in surgically created 1-wall periodontal intrabony defects in dogs by histometrical analysis. Material and Method: Critical sized($4\;mm\;{\times}\;4\;mm$), one wall periodontal intrabony defects were surgically produced at the proximal aspect of mandibular premolars in either right and left jaw quadrants in four canines. The control group was treated with debridement alone, and experimental group was treated with debridement and biphasic calcium phosphate application. The healing processes were histologically and histometrically observed after 8 weeks. Results: In biphasic calcium phosphate group, more new bone and cementum formation, less epithelium and connective tissue attachment were observed compared to other groups. But there was no statistical significance. Conclusion: Though the statistically significant difference could not be found, it seemed that there was more new bone and cementum formation with applying biphasic calcium phosphate in 1 wall intrabony defects in dogs by preventing junctional epithelium migration.

• Tuberculosis and Respiratory Diseases
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• 제50권5호
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• pp.641-644
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• 2001

Pulmonary blastoma is a family of tumors in which the glands or mesenchyme composing the neoplasm are primitive or embryonic in appearance. There are three subtypes, which include well differentiated fetal adenocarcinoma (pulmonary endodermal tumor), biphasic pulmonary blastoma, and cystic and pleuropulmonary blastomas in children. Among them, biphasic pulmonary blastoma is a primary malignancy of the lung originating from multipotential pulmonary blastema including both the malignant fetal epithelial and mesenchymal components. These make up 0.25 to 0.5 percent of all primary malignant lung tumors. This tumor is usually symptomatic and appears as a large, solitary peripheral mass, with a tendency to favor the upper lobe. Here we report a case where a small sized asymptomatic peripheral lung mass was diagnosed as a biphasic pulmonary blastoma, prior to the operation, A subsequent percutaneous needle biopsy was performed, which revealed features of a large cell neuroendocrine tumor. In addition, a review of the relevant literature is provided.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4843-4845
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• 2012

Cancer is now a worldwide problem. Although we have obtained a deeper understanding of the disease with the help of the science and technology, we still cannot reach the essence of cancer. Based on the former theory of carcinogenic and researches, we submit a new theory called "Spatial -Temporal Biphasic Carcinogenesis" to explain its development from the viewpoints of time and space.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2761-2764
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• 2003

본 논문에서는 개발된 biphasic 자동형 제세동기 시스템의 임상적 효용성을 동물실험을 통하여 검증하였다. 개발된 제세동기 시스템은 기존의 monophasic 제세동기와는 달리 낮은 에너지로 세동을 제거하는 biphasic 형으로, 이미 실험실 환경의 테스트를 통해 시스템의 안정성과 알고리즘의 탁월한 검출 능력이 확인되었다. 시스템의 임상적 안전성 및 효용성을 확인하기 위하여 8마리의 돼지를 사용하여 시스템의 적절한 세동 검출 및 세동제거능력을 실험하였고, 그 후 시스템의 효용성을 향상시키기 위한 연구로 같은 양의 에너지를 다른 전압 레벨에서 방전시켜 이에 따른 제 세동 효율을 조사하고, 또한 세동 신호의 규칙성과 방전시점에 따른 제 세동 효과를 평가하였다.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.814-819
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• 2015

The natural crosslinking agent genipin has been applied widely in biomedicines and foods nowadays. Because of the special hemiacetal ring structure in its molecule, it can only be prepared by hydrolysis of geniposide according to biocatalysis. In this research, strategies including aqueous-organic biphasic catalysis and substrate fed-batch mode were adopted to improve the biocatalysis process of genipin. A 10 L ethyl acetate-aqueous biphasic system with geniposide fed-batch led to a satisfying genipin yield. With Fusarium solani ACCC 36223, 15.7 g/l genipin in the ethyl acetate phase was obtained, corresponding to space-time yields of 0.654 g l^-1 h^-1.

• Tuberculosis and Respiratory Diseases
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• 제55권4호
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• pp.408-412
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• 2003

본례에서는 자연적으로 발생한 기흉으로 발견된 이상성 폐 모세포종을 수술과 cisplatin에 의한 화학요법을 시행하여 성공적으로 시험하였기에 문헌 고찰과 함께 보고하는 바이다.