• Journal of Biomedical Engineering Research
• /
• v.21 no.3 s.61
• /
• pp.321-331
• /
• 2000

Multiple 15-hue tests were designed and implemented on a PC in the study so as to quickly and quantitatively evaluate color vision acuity. Difficulty of the test was control)ed by the value of CDBACC (color difference between adjacent color chips) calculated using a CIELAB formula. The multiple 15-hue tests consist of eight of the hue tests (test 3-10) and three of the basic color (red, green, blue) tests (test 11-13). The 15 colors used for the hue tests were specified by the 15 color coordinates that were located at a constant distance (d = 2. 3. 5. 7, 10, 20, 30. 40) from white reference in the CIE chromaticity coordinate system and were separated by a constant color difference (CDBACC = 0.75, 1.1, 1.8. 2.5. 3.5. 7.5. 11, 14) from the adjacent chips. The color coordinates for the 15 chips for the basic color tests were the same as those of the 15 points spaced equally by a constant color difference (6.87 for the green color test. 7.27 for the red color test, 7.86 for the blue color test) from the white reference along the axis of red, green and blue. Thirty normal subjects who were not color blind were taken to undergo the multiple 15-hue tests. It was observed that most of the subjects correctly arranged color chips for the tests with CDBACC greater than 5, whereas no one correctly answered for those with CDBACC less than 2. Rapid changes in the number of the subjects correctly arranged took place when CDBACC of the tests was between 2 and 4.5. In the basic color tests, unlike the hue tests having similar values of CDBACC, it was seen that the subjects arranged color chips even less correctly. It was found that JNCD (just noticeable color difference) - a measure of color vision acuity was about 3 in average for the subjects. The JNCD was chosen as the value of the CDBACC of the test for which about $50\%$ of the subjects failed to successfully arrange color chips. ERCCA (error rate of color chips arrangement) for the test with CDBACC the same as the JNCD was shown to be about $20\%$. It is expected that the multi 15-hue tests implemented on a PC in the study will be an economical tool to quickly and quantitatively evaluate color vision acuity and, accordingly, the tests can be used for early diagnosis to massive potential patients suffering from diseases (ex. diabetes, glaucoma) which may induce changes in color vision acuity.

• Journal of Biomedical Engineering Research
• /
• v.25 no.6
• /
• pp.599-604
• /
• 2004

Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

• Journal of Biomedical Engineering Research
• /
• v.19 no.4
• /
• pp.393-401
• /
• 1998

Based on clinical observations, it is suspected that the bone-tendon origin is the site where piratical failure, leading to pathophysiological changes in the humeral epicondyle after repetitive loading, is initiated Mechanical properties and failure patterns of the common extensor and flexor tendons of the humeral epicondyle under static and repetitive loading have not been well documented. Our goal was to determine mechanical properties of failure strength and strain changes, to correlate strain changes and the number of cyclic repetitions, and to identify the failure pattern of bone-tendon specimens of common extensor and flexor tendons of the humeral epicondyle. Mechnaical properties of human cadaver bone-tendon specimens of the common extensor and flexor tendons of the humeral epicondyle were tested under two different loading rates. No statistically significant difference in ultimate tensile strength was found between male and female specimens or between slow (10 mm/sec) and fast elongation (100 mm/sec) rates. However, a statistically significant difference in ultimate tensile strength between the common extensor (1190.0 N/$cm^2{\pm}$388.8) and flexor 1922.0 N/$cm^2{\pm}$764.4)tendons was found (p<0.05). When loads of 25%, 33%, and 41% of the ultimate tensile strength of their contralateral sides were applied, the number of cycles required to reach 24% strain change for the common extersor and flexor tendons were approximately 8,893, 1,907, and 410, respectively. The relationship between cycles and loads was correlated ($R^2$=0.46) Histological observation showed that complete or partial failure after tensile or cyclic loadings occurred at the transitional zone, which is the uncalcified fibrocartilage zone between tendon and bone of the humeral epicondyle. Sequential histological sections revealed that failure initiated at the upper, medial aspect of the extensor carpi radialis brevis tendon origin. Biomechanical and hstological data obtained in this study indicated that the uncalcified fibrocartilage zone at the bone-tendon origin of the common extensor and flexor tendons is the weak anatomical structure of the humeral epicondyle.

• Korean Journal of Food Science and Technology
• /
• v.30 no.6
• /
• pp.1470-1475
• /
• 1998

Two kinds of Korean rice-wine (Yakju) with different process and ingredients, and Japanese rice-wine (Sake) were chosen for this study, and throughly dried and solubilized in water or cell culture medium. In vitro cytotoxicity assays of the solubilized wine solids exhibited that maximum dilution factors for inhibition of B 16BL6 mouse melanoma cell growth were 16X for herbal medicine-added rice-wine (Korean rice-wine I) and typical Korean rice-wine (Korean rice-wine II), and 8X for Japanese rice-wine. Their cytotoxic effects on HRT18 human colon adenocarcinoma cells were even lower than those on B16BL6 cells. The morphology of the tumor cells were changed by addition of the solubilized wine solids. Inhibitory effect of the rice-wine on in vivo tumor growth and metastasis were monitored after implantation of B16BL6 cells into C57BL/6 mice with daily feeding the solubilized wine solids. Compared to non-fed control groups, B16BL6 tumor growth and metastasis to lung were clearly inhibited by feeding the wine solids, in order of Korean rice-wine I > Korean rice-wine II > Japanese rice-wine. The data of in vitro cytotoxicity and the cell shape changes indicate that the inhibitory effect of tumor progression may be attributed to tumor cell differentiation or immune stimulation induced by certain components in the rice-wine, rather than direct cytotoxicity of the components.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.10
• /
• pp.1371-1377
• /
• 2012

Biological activities of Korean Panax ginseng 55% ethanol extract (KPGE) were investigated. The measured total polyphenol content of KPGE was 357.45 mg/100 g. KPGE showed the highest ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) radical scavenging activities of 80% and 86% at 1,000 ${\mu}g/mL$, respectively. DPPH and ABTS radical scavenging activities significantly increased in a KPGE concentration-dependent manner. SOD-like activity of KPGE (1, 10, and 100 ${\mu}g/mL$) increased from 22% up to 33% at KPGE concentrations of 500 and 1,000 ${\mu}g/mL$. KPGE treatment significantly suppressed the generation of pro-inflammatory mediators, including nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), and cytokines (tumor necrosis factor-alpha: TNF-${\alpha}$, interleukin-6: IL-6, interleukin-$1{\beta}$: IL-$1{\beta}$), in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. KPGE demonstrated strong anti-inflammatory activity that reduced NO and $PGE_2$ production in LPS-stimulated RAW 264.7 cells. Even low concentrations of KPGE (1 and 10 ${\mu}g/mL$) reduced $PGE_2$ and NO production in RAW 264.7 macrophages without LPS-stimulation, respectively. At concentrations of 100, 500, and 1,000 ${\mu}g/mL$, TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 production were significantly suppressed. The results of our study suggest the potential of Korean Panax ginseng as an excellent antioxidant substance for inhibiting inflammatory mediators. Therefore, Korean Panax ginseng (KPGE) may be used as a therapeutic approach to various inflammatory diseases.

• Microbiology and Biotechnology Letters
• /
• v.42 no.1
• /
• pp.58-66
• /
• 2014

In the course of study for a use for non-edible parts of broccoli (Brassica oleracea L), and the development of processed food utilizing these parts, edible floret and non-edible stalk were extracted with ethanol and different organic solvent fractions were prepared. With 10 different extracts and fractions, their useful components and various biological activities, such as antioxidant, antimicrobial and anti-proliferation activity, were investigated. The stalk has more abundant water soluble carbohydrate when compared with the floret, and floret has higher hexane-soluble pigments. Analysis of total flavonoid and total polyphenol contents showed that the floret has 1.5~1.99 times higher concentrations than the stalk. Among the fractions, ethylacetate (EA) fractions have the highest amount of total flavonoid and total polyphenol. The stalk and floret possessed 9.45 and 42.01 mg-total flavonoid/g, respectively. In the antioxidation activity assay, the EA fraction of floret showed strong radical scavenging activity and reducing power, while the n-hexane fraction of the stalk exhibited nitrite scavenging activity. In the antimicrobial activity assay, the EA fraction of floret showed a strong and broad-range of antibacterial activity, irrespective of gram positive or gram negative bacteria. In a while, the hexane and EA fractions revealed anti-proliferative effects against the human colorectal cancer cell HCT-116. Strong anti-proliferative activities were found in the hexane fraction of stalk (18.4% of cell viability), and the n-butanol fraction of floret (6.9% of cell viability). Our results suggest that the further study of the characterization of active fractions and the identification of active components from different parts of broccoli are needed to develop functional foods or novel plant-derived medicines.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.1
• /
• pp.43-52
• /
• 2000

Deodorization characteristics and removal rate of sulfur-containing odor have been investigated in the soil filter reactors packed with montmorillonites (Mont.), rice hulls(Rh.), and thickening-activated sludge(Ts.). And variation of pH and $SO_4{^{2-}}$ with the removal of malodorous sulfur compounds have been investigated together. As compared removal rate of montmorillonites between wet and dry condition for sulfur compounds through batch test, it showed that wet condition was better than dry one; removal ratio, as wet/dry, was $H_2S$ of 1.2 and $CH_3SH$ of 1.9, and decrease of pH and increase of $SO_4{^{2-}}$ concentration in the wet condition also showed to be larger than in dry condition. In continuous test for biological deodorization experiment, removal rate of sulfur compounds in reactor packed with Mont., Rh. and Ts, was more than 98 %, and the variation of static pressure was maintained stably under condition of SV $150h^{-1}$, LV 4.2 mm/sec and SV $200h^{-1}$, LV 5.6 mm/sec, and in reactor packed with Mont. and Rh., $H_2S$ was 76.4 % to 87.2 % and $CH_3SH$ was 87.8 % to 93.3 % under the same condition. From above results, it ascertained that it can obtain the high deodorization efficiency by inoculating thickening-activated sludge in soil filter using montmorillonites.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.11
• /
• pp.783-789
• /
• 2011

Recently, auto-thermal thermophilic aerobic digestion (ATAD) has a great attention for destruction of wasted sludge biomass in wastewater treatment plant. Reduction of sludge concentration has been successfully achieved with pilot scale ATAD and ceramic filtration process in field condition. However, high concentration of COD, total nitrogen (TN) and total phosphorus (TP) was observed in filtrate, which should be treated before recirculation of filtrate to biological wastewater treatment plant. This study was focused on removal of nitrogen and phosphorus contained in the filtrate of ATAD, using struvite crystallization method. The effect of operational and environmental parameters (such as, N, P and Mg ion concentration and molar ratio, pH, reaction time, agitation strength, seed dosage, and reaction temperature) on the treatment of TN and TP with struvite crystallization were evaluated. Magnesium (as $MgCl_26H_2O$) and phosphorus (as $K_2HPO_4$) ions were, if necessary, added to increase nitrogen removal efficiency by the crystal formation. Average concentration of $NH_4^+-N$ and $PO_4^{3-}-P$ of the filtrate were 1716.5 mg/L and 325.5 mg/L, respectively. Relationship between removal efficiencies of nitrogen and phosphorus and molar ratios of $Mg^{2+}$ and $PO_4^{3-}-P$ to $NH_4^+-N$ was examined. Crystal formation and nitrogen removal efficiencies were significantly increased as increasing molar ratios of magnesium and phosphorus to nitrogen. As molar ratio of $Mg^{2+}:PO_4^{3-}-P:NH_4^+-N$ were maintained to 2 : 1 : 1 and 2 : 2 : 1, removal efficiencies of nitrogen and phosphorus were 71.6% and 99.9%, and 93.8% and 98.6%, respectively. However, the effect of reaction time, mixing intensity, seed dose and temperature on the struvite crystallization reaction was not significant, comparing to those of molar ratios. Settled sludge volume after struvite crystallization was observed to be reduced with increase of seed dose and to be increased at high temperature.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.1
• /
• pp.25-31
• /
• 2011

In this study, model-based $NH_4-N$ predictive control algorithm by using influent pattern was developed and evaluated for effective control application in $A^2/O$ process. A pilot-scale $A^2/O$process at S wastewater treatment plant in B city was selected. The behaviors of organic, nitrogen and phosphorous in the biological reactors were described by using the modified ASM3+Bio-P model. A one-dimensional double exponential function model was selected for modeling of the secondary settlers. The effluent $NH_4-N$ concentration on the next day was predicted according to model-based simulation by using influent pattern. After the objective effluent quality and simulation result were compared, the optimal operational condition which able to meet the objective effluent quality was deduced through repetitive simulation. Next the effluent $NH_4-N$ control schedule was generated by using the optimal operational condition and this control schedule on the next day was applied in pilot-scale $A^2/O$ process. DO concentration in aerobic reactor in predictive control algorithm was selected as the manipulated variable. Without control case and with control case were compared to confirm the control applicability and the study of the applied $NH_4-N$control schedule in summer and winter was performed to confirm the seasonal effect. In this result, the effluent $NH_4-N$concentration without control case was exceeded the objective effluent quality. However the effluent $NH_4-N$ concentration with control case was not exceeded the objective effluent quality both summer and winter season. As compared in case of without predictive control algorithm, in case of application of predictive control algorithm, the RPM of air blower was increased about 9.1%, however the effluent $NH_4-N$ concentration was decreased about 45.2%. Therefore it was concluded that the developed predictive control algorithm to the effluent $NH_4-N$ in this study was properly applied in a full-scale wastewater treatment process and was more efficient in aspect to stable effluent.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.3
• /
• pp.295-303
• /
• 2011

BACKGROUND: Anaerobic digestion process is recently adapted technology for treatment of organic waste such as animal manure because the energy embedded in the waste can be recovered from the waste while the organic waste were digested. Ever increased demand for consumption of meat resulted in the excessive use of antimicrobials to the livestocks for more food production. Most antimicrobials administered to animals are excreted through urine and feces, which might highly affect the biological treatment processes of the animal manure. The aim of this study was to investigate the effects of antimicrobials on the efficiency of anaerobic digestion process and to clarify the interactions between antimicrobials and anaerobes. METHODS AND RESULTS: The experiment was consisted of two parts 1) batch test to investigate the effects of individual antibiotic compounds on production of methane and VFAs(volatile fatty acids), and removal efficiency of organic matter, and 2) the continuous reactor test to elucidate the effects of mixed antimicrobials on the whole anaerobic digestion process. The batch test showed no inhibitions in the rate of methane and VFAs production, and the rate of organic removal were observed with treatment at 1~10 mg/L of antimicrobials while temporary inhibition was observed at 50 mg/L treatment. In contrast, treatment of 100 mg/L antimicrobials resulted in continuous decreased in the rate of methane production and organic removal efficiency. The continuous reactor test conduced to see the influence of the mixed antimicrobials showed only small declines in the methane production and organic matter removal when 1~10 mg/L of combined antimicrobials were applied but this was not significant. In contrast, with the treatment of 50 mg/L of combined antimicrobials, the rate of organic removal efficiency in effluent decreased by 2~15% and the rate of biogas production decreased by 30%. CONCLUSION(s): The antimicrobials remained in the animal manure might not be removed during the anaerobic digestion process and hence, is likely to be released to the natural ecosystem. Therefore, the efforts to decline the usage of antimicrobials for animal farming would be highly recommended.