• Korean Journal of Food Science and Technology
• /
• v.36 no.5
• /
• pp.804-811
• /
• 2004

Mean concentration of 2 artificial sweeteners, sodium saccharin and acesulfame K, in food samples and their daily intakes were estimated. Among 755 food samples, 57 contained these artificial sweeteners. Contribution rate to total estimated daily intake (%) of artificial sweeteners in food categories were high in danmooji for sodium saccharin and ice cream for acesulfame K. Total estimated daily intakes $({\Sigma}EDI)$ for different age groups were high in 30-49 year-old group for sodium saccharin and 13-19 year-old group for acesulfame K. Total estimated daily intakes $({\Sigma}EDI)$ of men and women were 5.91 and 4.89 mg/man/day, respectively. Total estimated daily intakes $({\Sigma}EDI)$ based on mean body weight of 55 kg were 4.13 and 1.25 mg/man/day for sodium saccharin and acesulfame K, respectively. These values ranged within 0.2-1.5% of acceptable daily intake (ADI) evaluated by FAO/WHO and 1.2-13.5% of theoretical maximum daily intake (TMDI), and, therefore, judged to be safe.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.2
• /
• pp.174-179
• /
• 2007

This study was carried out to investigate the effect of Gastrodiae elata Blume fractions on systolic blood pressure and serum lipid profiles in spontaneously hypertensive rats (SHR/NCrj) fed high fat diet. Twenty-four males SHR weighing approximately 160 g were randomly divided into four groups; A (low molecule, GR-1), B (polysaccharide, GR-2), C (protein, GR-3) fractions of G. elata Blume, respectively, and D (high fat diet as control). After orally tube feeding the fractions of G. elata Blume, there were no differences in final body weights among the treatment groups. Diet intake was somewhat high in the control group (D), but there were no significant differences in feed efficiency ratios. In terms of serum lipid profiles, total-cholesterol level was statistically higher in the control group (D) than in G. elata Blume fraction groups (p<0.05). Triglyceride levels of low molecule (A) and polysaccharide (B) groups were lower by 16% and 11%, respectively than that of the control group (D). HDL-cholesterol level was remarkably higher (p<0.05), whereas LDL-cholesterol level was significantly lower (by 25%) in the group B as compared to the control group (D). Atherogenic index (AI) of G. elata Blume fraction groups were significantly lower than in the control group (p<0.05). Reference blood pressure (RBP) showed an average of $180\sim190mmHg$ at 8 weeks old after 3 weeks on feeding high fat diet. Compared with RBP, final blood pressure of treatment groups (35 days after feeding the fractions of G. elata Blume gractions) were decreased by 1.7% (A), 5.5% (B) and 3.6% (C), respectively, but the control group (D) contrarily showed an increase of 2.6%. Especially, final systolic blood pressure of the polysaccharide group (B) was lower by 22 mmHg than that of the control group (D). From these findings, it can be suggested that polysaccharide fraction may improve blood serum lipids and should be considered as effective in lowering of blood pressure.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.33 no.2
• /
• pp.111-115
• /
• 2007

It is inevitable to use germicidal agents like parabens, imidazolidinyl urea, phenoxyethanol and chlorphenesin to preserve the cosmetics. Although effective in reducing microblological contamination, chemical preservatives are irritative, allergenic and even toxic to human skin. So it is needed to decrease or eliminate usage of preservatives in cosmetic products Glycerin, butylene glycol (BG), prorylene glycol (PG), and dipropylene glycol (DPG) are widely used in cosmetics as skin conditioning agent or solvents. At high concentrations, they have antimicrobial activities, but deteriorate product quality like sensory feeling or safety. The purpose of study is to evaluate the effects of polyols on antimicrobial and preservative efficacy and confirm whether using adjusted polyols can decrease the contents of preservatives without deterioration of the quality of cosmetics. Effects of common polyols on antimicrobial activities of general preservatives were measured. BG and PG significantly (p < 0.05) increased activities of preservatives, but glycerin influenced little. It was inferred from the regression analysis of the results with S. aureus that adding 1% of PG increased activities of preservatives up to $2.1{\sim}8.4 %$ and BG improved activities of preservatives up to $1.8{\sim}8.4 %$. The challenge test results for oil in water lotions and creams showed that BG and PG improved the efficacy of preservative systems up to 40 % at a range of $5.5{\sim}9.9 %$, but glycerin had little effect on it. The measured rates of improvement were analogous to the inferences from regression analysis. It can be concluded that is possible to reduce total chemical preservatives up to 40 %, consequently improve the safety and sensory quality of cosmetics with the precision control of polyols. Added to that, using this paradigm, low preservative contents, praraben-free system, and even preservative-free systems can be expected in the near future.

• Journal of the Korea Concrete Institute
• /
• v.27 no.2
• /
• pp.185-193
• /
• 2015

Ultra high performance concrete (UHPC) has been developed to overcome the low tensile strengths and brittleness of conventional concrete. Considering that UHPC, owing to its composition and the use of steel fibers, develops a compressive strength of 180 MPa as well as high stiffness, the top flange of the steel girder may be superfluous in the composite beam combining a slab made of UHPC and the steel girder. In such composite beam, the steel girder takes the form of an inverted-T shaped structure without top flange in which the studs needed for the composition of the steel girder with the UHPC slab are disposed in the web of the steel girder. This study investigates experimentally and analytically the flexural behavior of this new type of composite beam to propose details like stud spacing and slab thickness for further design recommendations. To that goal, eight composite beams with varying stud spacing and slab thickness were fabricated and tested. The test results indicated that stud spacing running from 100 mm to 2 to 3 times the slab thickness can be recommended. In view of the relative characteristic slip limit of Eurocode-4, the results showed that the composite beam developed ductile behavior. Moreover, except for the members with thin slab and large stud spacing, most of the specimens exhibited results different to those predicted by AASHTO LRFD and Eurocode-4 because of the high performance developed by UHPC.

• Journal of the Korea Concrete Institute
• /
• v.23 no.6
• /
• pp.711-722
• /
• 2011

Beam-column gravity or Intermediate Moment frames subjected to unexpected large displacements are vulnerable when no seismic details are provided, which is typical. Conversely, economic efficiency of those frames is decreased if unnecessary special detailing is applied as the beam and column size becomes quite large and steel congestion is caused by joint transverse reinforcement in beam-column connections. Moderate seismic design is used in Korea for beam-column connections of buildings with structural walls, which are to be destroyed when the unexpected large earthquake occurs. Nonetheless, performance of such beamcolumn connections may be substantially improved by the addition of steel fibers. This study was conducted to investigate the effect of steel fibers in reinforced concrete exterior beam-column connections and possibility for the replacement of some joint transverse reinforcement. Ten half-scale beam-column connections with non-seismic details were tested under cyclic loads with two cycles at each drift up to 19 cycles. Main test parameters used were the volume ratio of steel fibers (0%, 1%, 1.5%) and joint transverse reinforcement amount. The test results show that maximum capacity, energy dissipation capacity, shear strength and bond condition are improved with the application of steel fibers to substitute transverse reinforcement of beam-column connections. Furthermore, several shear strength equations for exterior connections were examined, including the proposed equation for steel fiber-reinforced concrete exterior connections with non-seismic details.

• Journal of the Korean earth science society
• /
• v.24 no.3
• /
• pp.205-215
• /
• 2003

A precise and dense Bouguer anomaly is one of the most important data to improve the knowledge of our environment in the aspect of geophysics and physical geodesy. Besides the precise absolute gravity station net, we should consider two parts; one is to improve the precision in gravity measurement and correction of it, and the other is the density of measurement both in number and distribution. For the precise positioning, we have tested how we could use the GPS properly in gravity measurement, and deduced that the GPS measurement for 5 minutes would be effective when we used DGPS with two geodetic GPS receivers and the baseline was shorter than 40km. In this case we should use a precise geoid model such as PNU95. By applying this method, we are able to reduce the cost, time, and number of surveyors, furthermore we also get the benefit of improving in quality. Two kind of computer programs were developed to correct crossover errors and to calculate terrain effects more precisely. The repeated measurements on the same stations in gravity surveying are helpful not only to correct the drifts of spring but also to approach the results statistically by applying network adjustment. So we can find out the blunders of various causes easily and also able to estimate the quality of the measurements. The recent developments in computer technology, digital elevation data, and precise positioning also stimulate us to improve the Bouguer anomaly by more precise terrain correction. The gravity data of various sources, such as land gravity data (by Choi, NGI, etc.), marine gravity data (by NORI), Bouguer anomaly map of North Korea, Japanese gravity data, altimetry satellite data, and EGM96 geopotential model, were collected and processed to get a precise and dense Bouguer anomaly in and around the Korean Peninsula.

• Journal of Korean Society of Forest Science
• /
• v.102 no.2
• /
• pp.210-215
• /
• 2013

Litterfall production represents a major contribution of carbon and nutrient cycling in forest ecosystems. This study was carried out to determine the litterfall production in a broadleaved deciduous forest at the Mt. Keumsan Long Term Ecological Research (LTER) site, Southern Korea. Littefall was collected monthly or bimonthly from the site for 7 years from 2004 to2010. Leaf and reproductive (catkins) litters showed a seasonal variation, but litters of needle, branch, and barks were not changed across the seasons. Annual leaf litter of Quercus serrata and Carpinus laxiflora were significantly different (p<0.05) but that of C. cordata, Chamaecyparis obtusa, and Pinus thunbergii was not significantly changed for 7 years (p>0.05). Annual average litterfall production was 5,223 kg/ha, but annual variations were very large with minimum of 4,110 kg/ha/yr in 2004 and maximum of 6,002 kg/ha/yr in 2007. Total litterfall comprised of 2,323 kg/ha/yr in Q. serrata, 442 kg/ha/yr in C. laxiflora, 157 kg/ha/yr in C. cordata, 131 kg/ha/yr in Acer pseudosieboldianum, 390 kg/ha/yr in other deciduous tree species, 74 kg/ha/yr in P. thunbergii, 37 kg/ha/yr in C. obtusa, 672 kg/ha/yr in branches, 515 kg/ha/yr in miscellaneous, 448 kg/ha/yr in reproductive parts, and 54 kg/ha/yr in barks. respectively. The results indicate that litterfall production of the Mt. Keumsan LTER site was yearly fructurated with the positive linear relationship between leaf or total litterfall and annual mean temperature if no disturbance such as a typoon, and was lower than that of other Korean LTER sites.

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.2
• /
• pp.217-224
• /
• 2000

Background : It is well known that when macrophages are stimulated with endotoxin, they produce a wide variety of cytokine mediators, including TNF-$\alpha$ and IL-1$\beta$. However, there is an alteration in the macrophages' responsiveness when they are challenged with repeated bouts of endotoxin, termed "endotoxin tolerance" which is regarded as a self-protective phenomenon from continuous stimulation. In this study, endotoxin tolerance in the peripheral blood monocytes of sepsis patients was evaluated. Methods : Fourteen patients with organism-documented sepsis were included. The severity of illness was evaluated by APACHE II score. Peripheral blood monocytes were isolated from the patients and diluted to $1{\times}10^5$ well. After stimulation with endotoxin (LPS of E. coli O114 : B4, 100 ng/ml), they were incubated at $37^{\circ}C$ in 5% $CO_2$ incubator for 24 hours. Supernatant was collected for the measurement of TNF-$\alpha$ and IL-1$\beta$ with ELISA method. Peripheral blood monocytes of seven healthy volunteers were used as control. Results : The APACHE II score (mean$\pm$SD) of the patients at the time of blood sampling was 12.2$\pm$5.7. The primary infection foci were urinary tract infection, pneumonia, subacute bacterial endocarditis, and catheter related infection, etc. The causative organisms were gram negative rods (10 cases), gram positive cocci (6 cases) with two cases of mixed infection. Serum TNF-$\alpha$ could be measured in 4 cases with 29.9$\pm$27.7 pg/ml. Serum IL-1$\beta$was measurable in only one patient. The TNF-$\alpha$ level of supernatant of cultured peripheral blood monocytes was 2,703$\pm$2,066 pg/ml in patients and 2,102$\pm$1914 pg/ml in controls. The IL-1$\beta$level of supernatant was 884$\pm$1,050 pg/ml in patients and 575$\pm$558 pg/ml in controls. There was no difference of TNF-$\alpha$ and IL-1$\beta$ level between patients and controls. Conclusion : We cannot prove the phenomenon of endotoxin tolerance in this study. Future study needs to be focused on the more severe sepsis patients who were taken for sampling earlier. Addition of serum to the culture medium could be an another valuable option for the success of this study.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.3
• /
• pp.331-338
• /
• 1996

Background : Lung cancer continues to be the leading cause of cancer death in the United States and it's incidence has been rapidly increasing in Korea, too. The overall cure rate for non-small cell lung cancer(NSCLC) is approximately 10%, and the cure is generally achieved by surgery. Unfortunately, however, less than 15% of all patients and less than 25% of those who present with localized disease are candidates for curative surgical resection. So preoperative staging evaluation followed by curative resection has a major role in determining the long tenn prognosis of NSCLC patients. Therefore, we have conducted this study to compare pre-operative and post-operative staging and the long-tenn relapse-free survival rates in NSCLC patients according to its stage. Methods : We analyzed the medical records of 217 NSCLC patients who were operated on for curative resection in Seoul National University Hospital, retrospectively. Among them, 170 patients who were completely resected were selected to determine the long term relapse-free survival rates. Results : Among 217 NSCLC patients, men were 157 and women were 30. The median age was 58 and the difference between men and women was not found. The discrepancy rate between preoperative and postoperative staging was 40.1%. Its major cause was due to the difference of nodal staging. The 3-year relapse-free survival rates were 73%, 53% and 48% in stage I, II and IIIa, respectively. There was no difference of relapse-free duration in recurred patients according to the stage or histologic types. Conclusion : The postoperative pathologic staging determines the long tenn prognosis of patients with NSCLC after surgery, but current preoperative clinical staging can not predict the postoperative pathologic staging correctly. So the improved modality of staging system is required to predict the pathologic staging more correctly.

• Tuberculosis and Respiratory Diseases
• /
• v.48 no.6
• /
• pp.956-963
• /
• 2000

Backgrounds : Obstructive sleep apnea syndrome(OSA) can divided into two groups, positional(PP) and non-positional(NPP) obstructive sleep apnea syndrome, according to the body position while sleeping. In this study, we evaluated the differences of anthropometric data and polysomnographic recordings between the two types of sleep apnea syndrome. Materials : Fifty patients with OSA were divided two groups by Cartwright's criteria. The supine respiratory disturbance index (RDI) was at least two times higher than the lateral RDI in the PP group, and the supine RDI was less than twice the lateral RDI in the NPP group. This patients underwent standardized polysomnographic recordings. The anthropometric data and polysomnographic data were analyzed, statistically. Results : Of all 50 patients, 30% were found to be positional OSA. BMI was significantly higher in the PP group(p<0.05). Total sleep time was significantly longer in the PP group (350.6$\pm$28.2min, 333.3$\pm$46.0min, (p<0.05). Sleep efficiency was high in the PP group(89.6$\pm$6.4%, 85.6$\pm$9.9%, p<0.05). Deep sleep was significantly higher and light sleep was lower in the PP group than in the NPP group but no difference was observed in REM sleep between the two groups. Apnea index(AI) and RDI were significantly lower( 17.0$\pm$10.6, 28.5$\pm$13.3, p<0.05) and mean arterial oxygen saturation was higher in the PP group(92.7$\pm$1.8%. p<0.05) than in the NPP group. Conclusion : Body position during sleep has a profound effect on the frequency and severity of breathing abnormalities in OSA patients. A polysomnographic evaluation for suspected OSA patients must include monitoring of the body position. Breathing function in OSA patients can be improved by controlling their obesity and through postural therapy.