• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.192-195
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• 2005

The silicon thin film solar cells were fabricated by 13.56 MHz PECVD (Plasma-Enhanced Chemical-Vapor Deposition) and 60 MHz VHF PECVD (Very High-Frequency Plasma-Enhanced Chemical-Vapor Deposition). We focus on textured ZnO:Al films prepared by RF sputtering and post deposition wet chemical etching and studied the surface morphology and optical properties. These films were optimized the light scattering properties of the textured ZnO:Al after wet chemical etching. Finally, the textured ZnO:Al films were successfully applied as substrates for silicon thin films solar cells. The efficiency of tandem solar cells with $0.25 cm^2$ area was $11.8\%$ under $100mW/cm^2$ light intensity. The electrical properties of tandem solar cells were measured with solar simulator (AM 1.5, $100 mW/cm^2)$ and spectral response measurements.

• 열처리공학회지
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• 제17권2호
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• pp.87-93
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• 2004

Nitrocarburizing was carried out with various $CH_4$ gas composition with 4 torr gas pressure at $570^{\circ}C$ for 3 hours and post oxidation was carried out with 100% $O_2$ gas atmosphere with 4 torr at different temperatures for various time. In the case of plasma nitrocarburizing, It is that the ratio of ${\varepsilon}-Fe_{2-3}$(N, C) and ${\gamma}^{\prime}-Fe_4$(C, N), which comprise the compound layer phase, depend on concentrations of $N_2$ gas and $CH_4$ such that when the concentration of $N_2$ and $CH_4$ increased, the ratio of ${\gamma}^{\prime}-Fe_4$(C, N) decreased, but the ratio of ${\varepsilon}-Fe_{2-3}$(N, C) increased. The thickness of compound layer consistently increased as gas concentration increased regardless of $N_2$ and $CH_4$ expect when the concentration of $CH_4$ was 3.5 volume%, it decreased insignificantly. When oxidizing for 15min in the temperature range of $460{\sim}570{^\circ}C$, the study found small amount of $Fe_3O_4$ at the temperature of $460{^\circ}C$ and also found that amounts of $Fe_2O_3$. and $Fe_3O_4$ on the surface and amount of ${\gamma}^{\prime}-Fe_4$(C, N) in the compound layer increased as the increased over $460^{\circ}C$, but the thickness of the compound layer decreased. Corrosion resistance was influenced by oxidation times and temperature.

• Journal of Nutrition and Health
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• 제42권4호
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• pp.309-317
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• 2009

As far as we know, there were no studies of the effect of L-arginine on bone metabolism in post-menopausal women or ovariectomized rats. The primary objective of the current study was to determine whether arginine supplementation was associated with alterations in femoral and spinal bone mineral density (BMD) and bone markers in ovariectomized (Ovx) rats. Forty female Sprague-Dawley rats were divided into two groups, Ovx and sham groups, which were each randomly divided into two subgroups that were fed control and arginine supplemented diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. Bone resorption was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, insulin-like growth factor-1 (IGF-1), parathyroid hormone (PTH) and calcitonin were analyzed using radioimmunoassay kits. Bone mineral density (BMD) and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur. The serum and urine concentrations of Ca and P were determined. The plasma was analyzed for arginine. Diet did not affect weight gain, mean food intake, and plasma arginine concentration. Urinary Ca excretion was decreased by arginine supplementation in Ovx rats, but statistically not significant. The Ovx rats fed arginine-supplemented diet were not significantly different in ALP, osteocalcin, crosslinks value, PTH, calcitonin and IGF-1 compared to those fed control diet. The arginine-supplemented group had significantly higher serum Ca and growth hormone than control group. Spine and femur BMD were significantly increased by arginine supplementation on 5th and 9th weeks after feeding. Our findings indicate that dietary L-arginine supplementation decreased bone mineral density loss in Ovx rats. Therefore, dietary arginine supplementation may represent a potentially useful strategy for the management of osteoporosis.

• Journal of Nutrition and Health
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• 제39권7호
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• pp.641-648
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• 2006

This study was designed to evaluate the effect of the individual nutrition education for type 2 diabetes who participate the diabetes buffet. The subjects were 66 patients and divided into education (n=34) and control groups (n=32). The mean age of education and control groups were 59.8 and 56.6 years old, respectively. There were no differences in age and body mass index (BMI) between two groups. Initial glycosylated hemoglobin (HbA1c), post prandial plasma glucose (PP2), total plasma cholesterol, and blood pressure were not different between two groups. But fasting blood sugar (FBS) was higher in education group than in control group. On completion of the study, the education group showed significant decreases in body weight, BMI, FBS and PP2, however, the control group showed no changes in body weight, BMI and PP2, and showed a significant increase in FBS. Initial calorie and protein intakes of the education group did not meet the prescribed amount, however, mineral and vitamin intakes were higher than estimated average requirement (EAR). By the end of study, calorie and protein intakes were significantly increased to meet the prescription. In order to evaluate the effect of diet education, awareness of calorie requirement was used as an index of understanding diet prescription. The degree of awareness of calorie requirement was dependent on age: younger patients showed higher awareness than older subjects. The subject who showed better understanding of diet prescription showed lower levels of HbA1c, FBS, and PP2 at the end of the experiment period. The results of this study clearly show that individual diabetes diet education is effective to make the patient understand their diet prescription, and is effective to control body weight and blood sugar level. Awareness of calorie requirement could be used as an index of understanding of prescribed diet. Since age is an important variable to determine the awareness of calorie requirement, different strategies of nutrition education should be developed for different age groups, especially patients over 70 years old.

• 한국양식학회지
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• 제20권3호
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• pp.173-177
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• 2007

희석액과 동해방지제로 각각 ASP와 DMSO를 사용하여 1년 동안 냉동보존한 후 해동한 강도다리(Platichthys stellatus) 정자의 운동속도는 10% 농도에서 가장 빨랐다. Methanol의 경우 $10{\sim}20%$ 범위에서 유의한 차이를 보이지 않았지만 15%에서 가장 높은 값을 보였다. Glycerol을 동해방지제로 사용하였을 때는 첨가농도가 높아질수록 정자의 운동성과 운동속도가 낮아졌다. 희석액으로 SS를 사용한 경우도 ASP와 비슷한 결과를 보였다. 투과형전자현미경으로 관찰한 냉동하지 않은 신선한 강도다리 정자는 머리, 중편부 및 꼬리로 구성되어 있으며, 치밀한 핵질로 충만한 구형의 머리에는 첨체구조가 관찰되지 않았다. 동해방지제 없이 냉동보존한 경우, 대부분의 정자들이 머리가 찌그러지거나 부분적으로 수축되는 경우가 많았으며 머리의 원형질막이 이탈되고 염색질이 과립상으로 변하거나 균질화되지 않았다. 반면에 냉동보존을 위해 동해방지제를 사용한 경우 부분적으로 정자의 구조적 손상이 관찰되었으나 대부분의 정자는 냉동과 해동과정에서 손상을 입지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.181-189
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• 2011

Cryopreservation protocols induce partially irreversible damage to mammalian sperm plasma membranes. Previous studies have indicated that adding cholesterol to the plasma membrane, as cholesterol-loaded-cyclodextrins, improves cryosurvival of sperm. Therefore, the purpose of this study was to determine if treating sperm of Markhoz bucks with cholesterol-loaded-cyclodextrins (CLC) (0, 0.75, 1.5, 2.25 and 3 mg/ml diluted $240{\times}10^6$ sperm/ml) in Tris-citric acid-glucose diluents with and without egg yolk (containing 5% glycerol) would improve the post-thaw sperm quality. The motion characteristics were evaluated with a Computer Assisted System Analyzer (CASA); acrosome integrity and vitality were measured with the triple-stain technique. Samples were recovered before and after freezing by means of putting straws into $37^{\circ}C$ water for 30 sec and then parameters were assessed. The results showed that the treatments significantly affected motility, progressive motility, recovery rate, curvilinear velocity, beat cross frequency, live sperm with reacted acrosome, live sperm with unreacted acrosome, dead sperm with reacted acrosorne, and dead sperm with unreacted acrosome during freezing (p<0.05). However; no significant differences were found for average path velocity, straight line velocity, amplitude of lateral head displacement, straightness and linearity (p>0.05). The best results were observed for extender containing 2.25 mg/ml ($240{\times}10^6$ sperm/ml) CLC supplemented with 2.6% egg yolk. In conclusion, the findings of this study indicate improved Markhoz sperm viability and motility following treatment in the presence of egg yolk.

• Journal of Korean Neurosurgical Society
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• 제51권1호
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• pp.8-13
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• 2012

Objective : This is prospective study of clinical outcomes of percutaneous plasma disc coagulation Therapy (PDCT) in patients with herniated lumbar disc disease (HLD) to evaluate the safety and efficacy in its clinical application and usefulness as a reliable alternative to microscopic discectomy. Methods : Forty-six patients were enrolled in this study from April 2006 to June 2010. All patients had one-level HLD. Disc degeneration was graded on routine T2-weighted magnetic resonance Image (MRI) using the Pfirrmann's grading system and all index levels were grade 3 and grade 4. Indications for surgery were radiculopathy caused by disc protrusion with soft consistency. MRI was done at one month after the procedure in all patients to check post-PDCT change. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria. Results : This study was approved by the Institutional Review Board of our institution. The age of the study population ranged from 16 to 59 years with a mean age of 37.2 years. There were 29 males and 17 females in this study. The mean period of clinical follow-up was 21 months. The average preoperative VAS score for radiculopathy was $7.4{\pm}1.4$, while the final follow-up VAS score was $1.4{\pm}0.7$ (p<0.001). In MacNab's criteria, 41 patients (89.1%) had achieved favorable improvement (excellent and good) until later follow-up. There were one patient from infection and two patients who needed to convert to open discectomy. Conclusion : PDCT is a safe and efficient treatment modality in a selective patient with HLD.

• 대한수의학회지
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• 제58권1호
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• pp.9-16
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• 2018

A preliminary study into the protective mechanisms of adaptive immunity against porcine reproductive and respiratory syndrome virus (PRRSV) in piglets (n = 9) born to a gilt challenged intranasally with a type-2 PRRSV. Immune parameters (neutralizing antibodies, $CD3^+CD4^+$, $CD3^+CD8^+$, $CD3^+CD4^+CD8^+$ T-lymphocytes, and PRRSV-specific interferon $(IFN)-{\gamma}$ secreting T-lymphocytes) were compared with infection parameters (macro- and microscopic lung lesion, and PRRSV-infected porcine alveolar macrophages ($CD172{\alpha}^+PRRSV-N^+\;PAM$) as well as with plasma and lymphoid tissue viral loads. Percentages of three T-lymphocyte phenotypes in 14-days post-birth (dpb) peripheral blood mononuclear cell (PBMC) had significant negative correlations with percentages of $CD172{\alpha}^+PRRSV-N^+\;PAM$ (p < 0.05) as well as with macroscopic lung lesion (p < 0.01). Plasma and tissue viral loads had significant (p < 0.05) negative correlations with $CD3^+CD4^+CD8^+$ T-lymphocyte percentage in PBMC. Frequencies of $CD3^+CD8^+$ and $CD3^+CD4^+$ T-lymphocytes in 14-dpb PBMC had significant negative correlations with of lymph node (p = 0.04) and lung (p = 0.002) viral loads. $IFN-{\gamma}$-secreting T-lymphocytes frequency had a significant negative correlation with gross lung lesion severity (p = 0.002). However, neutralizing antibody titers had no significant negative correlation (p > 0.1) with infection parameters. The results indicate that T-lymphocytes contribute to controlling PRRSV replication in young piglets born after in-utero infection.

• 한국산업보건학회지
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• 제30권2호
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• pp.196-204
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• 2020

Objective: Chronic obstructive pulmonary disease(COPD) is characterized by persistent airflow limitations associated with chronic inflammatory response due to noxious particles or gases in the lung. Increasing oxidative stress associated with COPD. The aim of this study was to evaluate the influencing factors of biomarkers for oxidative stress in retired miners with COPD. Methods: The levels of total peroxide(TPx), total antioxidant capacity(TAC), and oxidative stress index(TPx/TAC ratio, OSI) in plasma as biomarkers for oxidative stress, serum C-reactive protein(CRP) as a biomarker for inflammation, and general characteristics were measured in 93 male subjects with COPD. COPD was defined as post bronchodilator FEV₁/FVC<0.7 by spirometry. Results: Mean levels of TPx(p=0.013), TAC(p=0.010), OSI(p=0.040), and CRP(p=0.024) were higher in current smokers. Levels of TPx(β=0.445, p<0.001), TAC(β=0.490, p<0.001), and OSI(β=0.351, p<0.001) were related to CRP levels, and CRP levels were related to %FEV₁ predicted(β=-0.295, p=0.003) and current smoking(β=0.214, p=0.032). Conclusions: These results suggest that oxidative stress was related to inflammation, and inflammation were related to decreasing %FEV₁ predicted and current smoking in retired miners with COPD.

• 한국분말재료학회지
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• 제18권5호
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• pp.430-436
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• 2011

Joining of NiO-YSZ to 316 stainless steel was carried out with B-Ni2 brazing alloy (3 wt% Fe, 4.5 wt% Si, 3.2 wt% B, 7 wt% Cr, Ni-balance, m.p. 971-$999^{\circ}C$) to seal the NiO-YSZ anode/316 stainless steel interconnect structure in a SOFC. In the present research, interfacial (chemical) reactions during brazing at the NiO-YSZ/316 stainless steel interconnect were enhanced by the two processing methods, a) addition of an electroless nickel plate to NiO-YSZ as a coating or b) deposition of titanium layer onto NiO-YSZ by magnetron plasma sputtering method, with process variables and procedures optimized during the pre-processing. Brazing was performed in a cold-wall vacuum furnace at $1080^{\circ}C$. Post-brazing interfacial morphologies between NiO-YSZ and 316 stainless steel were examined by SEM and EDS methods. The results indicate that B-Ni2 brazing filler alloy was fused fully during brazing and continuous interfacial layer formation depended on the method of pre-coating NiO-YSZ. The inter-diffusion of elements was promoted by titanium-deposition: the diffusion reaction thickness of the interfacial area was reduced to less than 5 ${\mu}m$ compared to 100 ${\mu}m$ for electroless nickel-deposited NiO-YSZ cermet.