• 한국우주과학회:학술대회논문집(한국우주과학회보)
• /
• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
• /
• pp.17-17
• /
• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• KSBB Journal
• /
• 제21권3호
• /
• pp.204-211
• /
• 2006

IFN-${\gamma}$의 대량생산을 위한 기초연구로서 IFN-${\gamma}$의 아미노 말단에 glucagon과 ferritin을 융합파트너로 각각 결합시켜 재조합 IFN-${\gamma}$의 발현을 유도하였다. 대장균 내에서 발현되는 IFN-${\gamma}$는 그 자체로 매우 강한 소수성 결합의 양상을 나타내어 inclusion body 형태로 발현된다고 알려져 있으나 OrigamiTM(DE3) 균주로부터 50% 이상의 수용성 형태로 발현시켰다. IFN-${\gamma}$로부터 융합파트너를 제거할 수 있는 system을 개발하기 위해 융합파트너와 IFN-${\gamma}$ 사이에 enterokinase cleavage site를 도입하였으며, enterokinase에 의해 IFN-${\gamma}$에는 영향을 미치지 않고 효과적으로 융합파트너를 제거할 수 있었다. 재조합 IFN-${\gamma}$의 분리 및 정제를 위해 발현벡터상의 융합파트너와 IFN-${\gamma}$사이에 6X His-tag을 도입하였고 융합파트너의 N-말단에도 6X His-tag을 추가적으로 도입함으로써 융합파트너와 더불어 enterokinase에 의해 분해되지 않은 융합단백질을 Ni-NTA agarose column으로 제거함으로서 IFN-${\gamma}$를 완전 정제할 수 있었다. IFN-${\gamma}$의 발현을 유도하는 발현유도체로서 15 mM lactose를 이용하여 5 L 발효조에서 IFN-${\gamma}$의 발현을 검토한 결과, 재조합 균체의 단위 건조질량(dry cell weight, g)으로 약 11 g DCW/L 수준의 재조합 융합단백질을 얻을 수 있었다.

• 대한의용생체공학회:의공학회지
• /
• 제6권2호
• /
• pp.1-8
• /
• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.

• 생명과학회지
• /
• 제20권8호
• /
• pp.1254-1260
• /
• 2010

식물 근권미생물은 식물의 뿌리 표면과 내부에 정착하면서 식물생장 촉진물질을 분비하여 식물생육에 직접적인 영향을 주거나, 항균물질을 분비하여 병원균으로부터 식물 근권환경을 보호하여 식물의 생육을 촉진하게 된다. 이러한 활성을 갖고 있는 미생물을 분리하여 동정하며, 항균물질을 분리, 동정하여 지속농업의 발전과 농업환경의 보전을 위하여 연구를 실시하였다. 논토양으로부터 식물생육촉진활성과 항균활성을 갖는 RRj 228균주를 분리하여, 생리 생화학적방법과 유전학적 방법으로 동정한 결과, Pseudomonas sp.로 동정되었다. RRj 228균주는 B. cinerea, P. ultimum, P. capsici와 R. solani에도 높은 항균활성을 보였으며, 특히 고추탄저병원균인 C. acutatum에 강력한 항균활성을 나타냈다. RRj 228균의 배양여액을 C. acutatum, R. solani 및 P. ultimum에 대한 $ED_{50}$값을 측정한 결과 0.14, 0.16, 0.29 mg/ml로 나타났다. 항균활성물질은 RRj 228 배양여액으로부터 각종 크로마토그라피법으로 순수분리하고, NMR과 GC/MS 등의 기기분석을 실시하여 구조를 Phenazine-1-carboxylic acid (분자량 224)로 동정하였다.

• 한국수산과학회지
• /
• 제27권5호
• /
• pp.482-494
• /
• 1994

우리나라에서 대량 생산되고 있는 진주담치 근육에서 Triton X-100를 사용하여 carotenoprotein을 추출, 정제하여 그 특성을 실험한 결과를 요약하면 다음과 같다. Carotenoprotein(${\lambda}_{max}=462nm$)를 $20\%$(w/v) $(NH_4)_2SO_4$, DEAE-cellulose 이온교환수지 그리고 Sephacryl S-300 겔 크로마토그래피를 통해 정제한 결과, 정제도는 5배 증가하였고 수율은 $1.85\%$였으며, carotenoprotein의 분자량은 약 372KDa(gel filtration)이었고, SDS-PAG 전기영동으로 단백질의 subunit를 확인한 결과, 60KDa($23.70\%$), 46.9KDa($9.14\%$), 26KDa($49.14\%$) 및 13KDa($18.02\%$)로 이루어져 있었다. Carotenoprotein의 안정성은 pH 4.0 이하의 강산 및 pH 10.0 이상의 강알칼리에서는 단백질이 불안정하였고, SDS 변성제를 $0.2\%$(w/v)되게 첨가하여 녹인 후 가시부 영역($400{\sim}600nm$)에서 최대파장 변화를 보면 462nm에서 456nm로 약 6nm 단파장 영역으로 이동한 것을 알 수 있었다. Carotenoprotein의 구성아미노산 조성은 threonine이 $35.90\%$로 다른 아미노산에 비해 함량이 높았으며, 필수아미노산과 소수성 아미노산의 함량은 전체아미노산 함량의 각각 $62.76\%$와 $25.02\%$를 차지하였고, methionine, histidine 및 proline은 존재하지 않았다. Carotenoprotein 1g당 총지질의 함량은 256mg였고, 그 구성지방산의 조성은 polyene산이 $62.4\%$로 가장 많았고 다음으로 포화산($19.58\%$)및 monoene산($18\%$) 순이었다. 특히, 16:4n-3의 조성비가 $33.90\%$로 상당히 높게 나타났고, EPA, DHA 등 w3 계의 장쇄(長鎖)고도불포화지방산의 조성비가 $22.13\%$로 높게 나타났으며, 양적으로 많은 지방산은 포화산 중에는 palmitic acid($C_{16:0}$), monoene산 중에서는 palmitoleic acid($C_{16:1}$), polyene산 중에서는 hexadecatetraenoic acid($C_{16:4}$), eicosapentaenoic acid ($C_{20:5}$), docosahexaenoic acid($C_{22:6}$) 등이 함량이 많았다. Carotenoprotein으로부터 분리한 총 caroteoid 함량은 $8.80mg\%$였고, 주 carotenoid는 mytiloxanthin($74.79\%$), 3,4,3'-trihydroxy-7',8'-didehydro-${\beta}$-carotene($18.26\%$)였다.

• 미생물학회지
• /
• 제38권3호
• /
• pp.153-161
• /
• 2002

Sox4는 DNA 결합 도메인인 HMG-box와 전사 활성 도메인인 serine rich region (SRR)과 아직 그 기능이 알려져 있지 않은 glycine rich region (GRR)등의 세 개의 기능 도메인을 가지는 전사인자이다. 전사인자인 Sox4는 생체 내 초기 분화 시 중요한 역할을 하는 유전자로 알려져 있으나 여전히 그 정확한 생리적 기능 및 세포 내에서 이 유전자 산물이 전사 활성 에 어떻게 관여하는지 그 정확한 기전은 잘 밝혀져 있지 않다. 이에 본 연구에서는 Sox4의 생리적 기능을 이해하고 세포 내에서 Sox4의 기능 연구에 유용하게 사용할 수 있는 항체를 제조하기 위해 Sox4를 대장균에서 발현, 정제하였다. 모든 기능 도메인을 다 포함하는 Sox4는 대장균에서 발현 시 대부분 절단되는 양상을 나타내었다. Sox4의 각 도메인을 대장균에서 GST-융합 단백질로 발현, 정제하여 그 발현 양상을 비교해 본 바 N-말단을 제거한 Sox4 ($\Delta$HMG)의 경우 67 kDa 크기의 단백질이 생성되므로 이 단백질을 항원으로 이용하여 Sox4의 GRR에 특이적으로 반응하는 항체를 제조하였다. 또한, 67 kDa 크기의 단백질 외에 34 kDa 크기에서 GST-융합 단백질이 관찰되었다. 이 밴드는 Sox4 (GRR)를 발현, 정제시에도 관찰되는 동일한 크기의 밴드이며 thrombin과의 반응을 통해 7 kDa 크기로 절단되는 Sox4 밴드이다. 그러므로 이 들 결과로부터 GRR 내에 단백질 분해효소의 표적 부위가 존재함을 확인할 수 있었다. 본 연구결과는 아직 그 기능이 밝혀져 있는 않은 Sox4의 새로운 도메인인 GRR이 단백질 분해 효소의 표적 부위로 작용하여 Sox4의 안정성을 조절함으로써 Sox4의 활성에 중요한 역할을 수행할 수 있다는 가능성을 제시하고 있다.은 억제 회복 효과는 $Mg^{2+}$에 의한 리보자임의 td intron 구조적 안정성에 기인하는 것으로 추정된다.력이 뛰어난(adaptable) 인간적 요구사항을 충족시켜야 한다. 셋째, 다이내믹 시미트리는 역(逆, reciprocity)의 원리와 보상(補賞, complement)의 원리를 제 1의 구성원리로 하며 공간에서 서로에 대한 역과 공통성(common property)을 갖고 자기유사를 지닐 때 연속체(continuum)를 손상하지 않고 전체공간을 유기체적으로 분절한다.같은 pattern 이었다. 그러나 JR89주에서는 280kb 가 나타나지 않아 다른 분리균주와 구분되었다.과 밀가루국(麴) 사이에 차(差)가 별(別)로 없었다.果)에서 총지질(總脂質)을 구성(構咸)하는 지방산(脂肪酸) 조성(組成)은 $C_{18:2}$산(酸), $C_{16:0}$산(酸)의 순(順)으로 그 함량(含最)이 맞은데 비(比)하여 각획분(各劃分)의 지질(脂質)을 구성(構成)하는 지방산(脂肪酸) 조성(組成)은 $C_{16:0}$산(酸), $C_{18:2}$산(酸)의 순(順)으로 그 함량(含量)이 많은 것으로 나타났으며 동결건조후(凍結乾燥後) 저장(貯藏)하는 동안에$C_{18:2}$산(酸), $C_{18:3}$산(酸)의 함량(含量)이 계속(繼續) 감소(減少)하고 있었다. 5. 4-monomethylsterol fraction에는 cycloartenol(20.6%)이 비교적(比較的) 높은 함량(含量)으로 함유(含有)되어 있었고, 그 외(外) cyclolaudenol, cycloeucalenol 및 citrostadienol 등이 함유(含有)되어 있었다. 6. 4-desmethylsterol fraction에

• 생명과학회지
• /
• 제25권9호
• /
• pp.1027-1035
• /
• 2015

미생물유래 다당류 생산균주를 분리하기 위해 전국 각지의 토양시료로부터 가장 높은 점성과 다당류 생산성을 나타내는 균주 GP32를 분리하였으며, 분리균주 GP32의 동정을 분리균주의 형태학적, 생리학적 특성을 조사한 결과, Pseudomonas 속 세균으로 확인되었으며 최종적으로 Pseudomonas sp. GP32로 명명하였다. 플라스크 수준에서 Pseudomonas sp. GP32의 다당류 생산을 위한 가장 적합한 탄소원과 질소원은galactose와 (NH₄)₂SO₄를 이용하였을 때 가장 많은 다당류를 생산하는 것으로 확인되었으며, 다당류 생산을 위한 최적의 C/N ratio는 50이었다. 다당류 생산을 위한 최적 pH와 온도는 각각 7.5와 32℃였다. 최적화된 배지를 이용한 fermentor 배양에서 다당류 생산은 배양 70시간에 최고치를 나타내었으며, 이때 다당류 생산량은 15.7 g/l이었다. Pseudomonas sp. GP32로부터 생산된 다당류는 ethanol 침전, cetylpyridimium 침전과 gel permeation chromatography를 통하여 정제하였으며, 정제된 다당류는 Biopol32로 명명하였다. Biopol 32의 분자량은 3×10⁷ datons이었으며, Biopol32가 함유하고 있는 구성당은 galactose : glucose : gulcouronic acid : galactouronic acid 등이 1.85 : 3.24 : 1.00 : 1.42의 몰비로 함유되어있다. Biopol32 용액은 의가소성 성질을 갖는 고분자 화합물로서 Zoogloea ramigera가 생산하는 생물고분자인 zooglan보다 모든 농도에서 높은 점성을 나타내었다. Biopol32의 실제 폐수처리현장에서 응집제로의 사용 가능성을 검토하기 위하여 식품폐수, 섬유폐수와 제지폐수를 대상으로 응집효율을 조사한 결과, 높은 COD 감소율 (58.4~67.3%)과 SS제거율(82.6~91.3%)를 나타내어 실제 산업폐수에서 뛰어난 응집효율을 나타내었다.

• 한국식품과학회지
• /
• 제45권3호
• /
• pp.285-292
• /
• 2013

Ametoctradin은 triazolopyrimidine계에 속하는 살균제로 역병탄저병을 예방하는 약제이다. 증기압은 $2.1{\times}10^{-10}$ Pa ($20^{\circ}C$)으로 매우 낮아 분석을 위한 기기로 LC를 선택하였으며, HPLC-PDA기기를 사용하여 210 nm에서 400 nm까지 스캔한 결과, 최대흡광파장을 292 nm으로 확인하고 이를 분석파장으로 선택하였다. 추출용매는 물질의 용해도를 고려하여 methanol로 선정하였으며, 액-액 분배 및 정제과정에서는 약제의 n-octanol/water 분배계수($logP_{ow}$, $25^{\circ}C$)가 4.40 (pH 7, $20^{\circ}C$)의 비극성의 물리화학적 특징을 가짐을 고려하여 액-액 분배 단계에서는 dichloromethane, 정제 단계에서는 acetone/hexane (30/70, v/v)을 분석을 위한 용매로 사용하였다. 특히, 컬럼 충진제로 유지, 색소의 비용출성이 우수하고 극성의 물질을 넓은 범위에서 흡착하는 특성을 가지는 florisil을 선택하여 약제에 대한 선택성을 높일 수 있었다. 본 분석법은 회수율 측정(71.9-112.6%)을 통해 코덱스 가이드라인(CAC/GL 40)인 회수율 70-120%, 분석오차 10 미만에 적합함을 보여주어 분석법의 정확성을 확인하였으며, LC-MS를 통한 재확인 과정을 수행함으로써 시험법의 신뢰성과 선택성을 확보할 수 있었다. 또한 재현성을 위해 실험실간 검증을 실시하였으며 그 결과, RSDR(%)는 >0.01 mg/kg, ${\leq}0.1\;mg/kg$범위에서 3.02-14.63%, >0.1 mg/kg범위에서 1.27-7.67%로 코덱스 가이드라인 기준에 적합한 것으로 나타났다. 따라서 본 연구에서 개발한 시험법은 농산물에 잔류하는 ametoctradin을 분석하기 위한 공정 시험법으로 활용할 수 있을 것으로 판단된다.

• 한국식품위생안전성학회지
• /
• 제34권1호
• /
• pp.13-21
• /
• 2019

본 연구는 2018년 국내식품 중 신규 기준설정 예정 농약인 스트렙토마이신의 잔류 농약 검사를 위한 공정시험법을 마련하기 위하여 수행하였다. 스트렙토마이신은 아미노글리코사이드계 항생제로 소, 돼지, 닭 등 가축 및 가금에 동물용의약품으로 허가되어 세균성 질병치료에 사용되고 있다. 또한 우리나라에서는 감귤, 매실, 참다래, 복숭아 등에 발병하는 세균성 병해를 방지하기 위하여 농약으로 등록되어 있다. 국내에서는 스트렙토마이신의 잔류물의 정의를 스트렙토마이신과 디히드로스트렙토마이신의 합으로 정하여 관리하고 있으며 잔류허용기준은 동물용의 약품으로 사용 시 불검출부터 1.0 mg/kg까지 설정되어 있다. 농약으로 사용 시 농산물 중 잔류허용기준은 설정되어 있지 않으며 식품공전의 시험법 역시 동물용의약품에 적용되는 시험법으로 설정되어 있다. 이에 농산물 중 잔류허용기준 설정을 위한 시험법 마련이 시급하여 본 연구에서는 식품공전에서 정하고 있는 대표농산물 5종(현미, 감자, 대두, 감귤, 고추)을 포함한 잔류시험법을 개발하고자 하였다. 따라서 수용성 유기용매인 메탄올의 적용과 포름산을 이용한 pH 조절을 통한 추출법 및 HLB 카트리지를 이용한 정제법을 최적화하여 LC-MS/MS에 의한 분석법을 확립하였다. 스트렙토마이신과 디히드로스트렙토마이신의 시험법 정량한계는 0.01 mg/kg으로 PLS 제도에 맞는 잔류허용기준 수준을 만족하였다. 스트렙토마이신과 디히드로스트렙토마이신의 평균 회수율은 각각 72.0~116.5%와 72.1~116.0%이었고, 상대표준편차는 각각 12.3%와 12.5% 이하로 조사되어 이러한 결과는 국제식품규격위원회 가이드라인(CAC/GL 40-1993, 2003)의 잔류농약 분석기준 및 식품의약품안전평가원의 '식품등 시험법 마련 표준절차에 관한 가이드라인(2016)'에 적합한 수준임을 검증하였다. 따라서 본 연구에서 개발한 시험법은 농산물 중 스트렙토마이신의 잔류검사를 위한 공정시험법으로 활용할 수 있으며 유사 농산물에 대한 적용도 가능하리라 판단되어 향후 국내 농산물 중 농약의 잔류허용기준 신설 및 잔류농약 검사의 기초자료로 활용 가능할 것이다.