• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.97-97
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• 2003

Embryonic stem (ES) cells, derived from preimplantation embryos, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES (hES, MB03) cells and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2 O_2$. Ratio of dying cells as determined by the relative amount of dye neutral red entrapped within the cells after the exposures. Cell death rates were not significantly different when either MB03 or HeLa were exposed up to 0.4 mM $H_2 O_2$. However, relative amount of dye entrapped within the cells sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2 O_2$, while it was approximately 54% in MB03. Pretreatment of cells with BSO (GSH chelator) and measurement of GSH content results suggest that cellular GSH is the major defensive mechanism of hES cells. Induction of apoptosis in hES cell was confirmed by DNA laddering, induction of Bax, and chromatin condensation. In summary, hES cells 1) are extremely resistant to oxidative stress, 2) utilize GSH as a major defensive mechanism. and 3) experience apoptosis upon exposure to oxidative stress.

• 한국세라믹학회지
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• 제21권3호
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• pp.221-230
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• 1984

In this study an investigation was made to determine optimum ratio between $SO_3$, MgO and $K_2O$ that maximizes $C_2S$ formation in Clinkering reaction Using response surface analysis method. It was proved that 1) Residual $K_2O$ int he clinker should be converted to $K_2SO_4$ because $K_2SO_4$ has less effect on the burnability than $K_2O$, 2) Optimum ratio if $SO_3$/K2O is 1.5, 3) Optimun balance between $CaSO_4$ and MgO is to be adjusted to such a level that w/o SO3=0.7(w/o MgO-2).4) In case of lack of $K_2O$ free CaO was minimized when $K_2SO_4$=2.3w/o and MgO=1.5w/o but if remaining $K_2O$ was 2w/o free CaI was minimized in the level that $K_2SO_4$=2.3w/o and MgO =1.5 w/o but if remaining $K_2O$ was 2 w/o free CaO was minimized in the level that $K_2SO_4$=4.5w/o and MgO =3.0 w/o.

• 대한한의학회지
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• 제22권4호
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• pp.114-120
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• 2001

Objectives : Man adapts himself to nature, so accordingly as he grows up, changes of body composition appear. This study measured the changes of body compositions on the ground of Sasang constitution and seasons Methods : 253 middle school students who live in Busan were studied from the 20th of March, 1999 to the 20th of March, 2001. We measured height and body compositions with Inbody 3.0, six times during that period. Results : According as they grew up, total body water, muscle area, body weight, BMI (Body Mass Index), BMR (Basal Metabolic Rate), ACM (Arm Muscle Circumference), and BCM (Body Cell Mass) increased, but fat body weight ratio decreased. From March to June, total body water, muscle area, height, ACM, and BCM increased. From September to December fat body weight, fat body weight ratio, waist hip ratio increased as compared with other seasons. Height of Soyangin and BMI of both Soyangin and Taeumin increased more than those of other groups, with statistical significance Conclusions : The growth of man is adapting oneself to changes of nature, and it corresponds to the theory of (correspondence between man and universe).

• 한방안이비인후피부과학회지
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• 제17권3호
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• pp.102-106
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• 2004

Obective : This study was designed to investigated clinical features and frequent parts of chronic paranasal sinusitis Method : The ratio of male and female, the distribution of symptoms, the frequent parts of paranasal sinusitis on PNS images were investigated in 26 patients who visited Department of otorhinolaryngology Semyung university Oriental medical hostipal during from march, 2004 to october, 2004. Results: 1. The ratio of male and female was 1:1.5 and the teens were high rate of age group 2. The results reveal1he most common symptoms as follows ; nasal stuffiness(28.1$\%$), rhinorrhea26.5$\%$), laryngopharyngial disorder(14$\%$). 3. The frequent parts of paranasal sinusitis on PNS images were ethmodial sinus, maxillary sinus, fronal sinus in good order. 4. 87.5$\%$ of patients show effective result in medical treatment Conclusion: We suggest that this results form the foundation of objectification of medical treatment of paranasal sinusitis

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.5-8
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• 2000

The population density of excited species in dc, rf and laser ablation plume plasmas has been measured using laser absorption spectroscopy. It was shown that, when the plasma was modulated by on and off with, the sensitivity and signal to noise (S/N) ratio became high. For example, the atomic O(3$^{5}$ S$^{o}$ $_2$) Population density, No* in $O_2$/He mixtures was obtained by the highest S/N ratio at a frequency of 2.7kHz. In a 20Torr room air, the lowest No* level to be detectable was shown to be an order of 10$^{7}$ cm$^{-3}$ . The population densities of resonance Ar(1S$_2$) and Xe(1S$_4$) levels were also measured in barrier discharges and laser ablation plasmas.

• Journal of Nutrition and Health
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• 제35권5호
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• pp.544-557
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• 2002

This study was performed to evaluate the quality of nutrient intakes of the hemodialysis patients (26 men and 23 women) according to the socioeconomic status by 3-day dietary recall in Daejeon city and Chungnam area, Korea. Mean age of the subjects was 50.7 yrs and BMI was 22.0 $\pm$ 0.4 kg/$m^2$. Education level was divided into two groups ($\leq$ 9 years： LE group, 9 years： HE group), and monthly family income level was divided into three groups (< 500,000 won: LI group, 500,000-1,499,999 won: MI group, $\geq$ 1,500,000 won : HI group). The data were analyzed by Student t-test and Oneway ANOVA using SPSS 9.0 version at p < 0.05 level. Intakes of energy, carbohydrates, cholesterol, potassium, thiamin and riboflavin were significantly higher in HE group than in LE group (p < 0.05). Intakes of all the nutrients except protein and phosphorus were less than Korean RDA, and INQs (Index of Nutritional Quality) of most nutrients were lower than 1.0 but cholesterol, phosphorus. thiamin and niacin being over 1.0 in HE group. MAR (Mean adequacy ratio) of all the nutrients (e.g., energy, protein, calcium, phosphorus, iron, vitamin A, vitamin C, thiamin, riboflavin and niacin) was significantly higher in HE group (0.61 $\pm$ 0.04) than in LE group (0.48 $\pm$ 0.03) at p = 0.036. Intakes of energy, protein (total, animal and plant), fat, cholesterol, potassium, calcium, phosphorus, iron, vitamin A, thiamin and riboflavin were also significantly higher in HI group than in LI and MI group (p < 0.05). Daily intakes of most nutrients were less than Korean RDA except protein ed phosphorus in HI poop, and INQs of thiamin, niacin and phosphorus were higher than 1.0, while those of calcium, iron, vitamin A and riboflavin were lower than 1.0. MAR of energy and 9 nutrients was significantly higher in HI group (0.70 $\pm$ 0.04) than in LI group (0. 56 0.04) and MI poop (0.47 $\pm$ 0.03) at p = 0.000. In conclusion, quality of nutrient intakes, especially energy and protein, was significantly influenced by socioeconomic status such as education and monthly income (p < 0.05). This result suggests that it would be very helpful to develop nutritional education programs considering hemodialysis patients' education levels, and to improve public supports (e.g., medical insurance system, low-rate lease system of dialysis equipments, etc.) focusing on the patients' family income levels f3r their better nutrition and health.

• 한국광학회지
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• 제1권2호
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• pp.155-161
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• 1990

메틸알코올 레이저의 여기용으로 저속축류형의 가변파장 $CO_2$ 레이저를 제작하였다. 파장가변은 ZnSe Brewster 창과 반사 회절격자를 사용하였으며, 반사 회절격자는 Blaze wavelength 10.6$\mu\textrm{m}$, 100grooves/mm 인 평면형이다. 실험은 $CO_2$ 레이저의 연속발진 출력특을 살펴보고, $CO_2$ 레이저의 전 발진구간을 파장가변시켜 얻어진 출력분포를 $CO_2$ 레이저의 이득 곡선과 비교하였다. 연속발진 출력은 기체 혼합비 $CO_2: N_2$ : He=1:3:10, 전류 55mA, 압력 14 torr 일 때 100W를 얻었다. 가변된 파장은 10.4$\mu\textrm{m}$ 영역의 R(6)-R(38), P(6)-P(36), 9.4$\mu\textrm{m}$ 영역의 R (10)-R(32), P(10)-P(38)의 약 60여개의 회전선이 발진함을 확인하였고, 이 때의 파장은 9.3295$\mu\textrm{m}$에서 10.7648$\mu\textrm{m}$까지 변화하였다. 각 영역에서 얻어진 출력분포는 $CO_2$ 레이저의 이득곡선과 잘 일치하였고, 최대 출력은 20W 정도였다.

• 한국결정성장학회지
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• 제16권4호
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• pp.149-156
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• 2006

For an aspect ratio (transport length-to-width) of 5, Pr = 2.89, Le = 0.018, Pe = 2.29, Cv = 1.11, $P_B$=40 Torr, solutally buoyancy-driven convection $(Gr_s=3.03{\times}10^5)$ due to the disparity in the molecular weights of the component A $(Hg_2Cl_2)$ and B (He) is stronger than thermally buoyancy-driven convection $(Cr_t=1.66{\times}10^4)$. The crystal growth rate is decreased exponentially for $2.5\;{\leq}\;Ar\;{\leq}\;5$, with (1) the linear temperature profile and a fixed temperature difference, (2) the imposed thermal profile, a fixed crystal region and varied temperature difference. This is related to the finding that the effects of side walls tend to stabilize convection in the growth reactor. But, with the imposed thermal profile, a fixed source region and varied temperature difference, the rate is increased far $2\;{\leq}\;Ar\;{\leq}\;3$, and remains nearly unchanged for $3\;{\leq}\;Ar\;{\leq}\;5$.

• 아시안잔디학회지
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• 제1권1호
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• pp.37-41
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• 1987

Effect of Rolling factor on the growth and thatch accumulation in tall fescue was studied from the viewpoint of estimate the rolling factor to obtain the highest values of growth characters and analysis of thatch accumulation. Rolling factors were 1.82, 3.33, 4.29 and 4.85, respectively. The results are may he summarized as follows ; 1. Rolling factor was affected to obstructive on the growth of tall fescue. Thus, the rolling factor ( RF) had significant negative correlated with the dry weight of plant ( DW ), leaf weight (LW), stem weight (SW), dry weight of thatch (Th), number of tillers (NT) and C / F ratio. 2. Rolling factor of 1.82 was an adequate rolling factor for the growth. 3. The dry weight of thatch(Th) had significant positive correlated with DW, LW, and NT, but negative correlated with the dry weight of thatch per a tiller ( th / NT). 4. Thatch accumulation system can be shown in following diagram. yield compnents - DW ~ Th - Rf (LW, SW, NT, C/F) th/NT 5. The dry weight of thatch per a tiller(th / NT) was a concerning factor for the losses of thatch.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1644-1650
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• 2023

In spent fuel reprocessing, UO₂(DBP)₂ (U-DBP) can be deposited in stainless steel equipment. U-DBP must be removed by dissolution and the process must not cause corrosion to stainless steel. This study was conducted to find the best scheme for dissolution. U-DBP was manufactured by the titrimetric sedimentation method. The effects of different factors on the dissolution of U-DBP were investigated. For example, solid-liquid ratio, hydrazine carbonate solutions with different mass components, mixed solutions containing different concentrations of H₂O₂, and different carbonates. The results indicated that U-DBP does not have a regular crystal morphology. With the increase of the solid-liquid ratio and the mass fraction of hydrazine carbonate, the concentration of U(VI) at the dissolution equilibrium increases gradually. The addition of H₂O₂ has a great promotion effect on the dissolution. However, when the concentration of H₂O₂ is greater than 0.5 M, the dissolution solution may have an erosive effect on the stainless steel. (NH₄)₂CO₃ can increase the dissolution capacity of dissolved U-DBP, but it may also accelerate the corrosion of stainless steel.