• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.29-37
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• 2005

This study was prospectively designed to determine the physiologic effects of normothermic CPB and to compare its influences with hypothermic CPB. Material and Method: Thirty-six adult patients scheduled for el­ective cardiac surgery were randomly assigned to moderate hypothermic (hypothermic group nasopharyngeal tem­perature $26\~28^{\circ}C,\;n=18)$ ornormothermic (normothermic group, nasopharyngeal temperature > $35.5^{\circ}C\;n=18)$ CPB. Arterial blood samples were taken before CPB (Pre-CPB), 10 minutes after the start of CPB (CPB-10), and imme­diately after CPB stop (CPB-off) for determining total leukocyte counts, neuron-specific enolase (NSE), interleukin-6 (IL-6), endothelin-1 (ET-1), cortisol, troponin I (TNI), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, blood urea nitrogen (BUN), and the pulmonary index $(Pi,\;PaO_{2}/FiO_{2}),$Other parameters such as urine output, mechanical ventilating period, ICU-staying period, postoperative complications and hospitalized days were also evaluated. Result: Total leukocyte counts, increased rate in NSE, in IL-6 and in cortisol at CPB-10 and CPB-off were significantly higher in normothermic group than in hyphothermic group. Urine output during CPB was lower in normothermic group than in hyphothermic group. The duration of mechanical ventilation, ICU-stay, and hospitalization were longer in normothermic group than in hyphothermic group. Conclusion: These findings sug­gested that normothermic CPB caused higher inflammatory and stress responses than hypothermic CPB during car­diac surgery using cold crystalloid cardioplegia. However, further studies with large number of cases should be carried out to validate this hypothesis.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.366-375
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• 2006

Background: Hypomagnesemia is a common complication after cardiac surgery with cardiopulmonary bypass. The purpose of this study was to assess the clinical beneficial effect of administration of magnesium sulfate in cardiac surgery. Material and Method: Thirty five patients scheduled for elective cardiac surgery were randomly assigned to magnesium group (n=20) which received magnesium sulfate in priming solution (1 g) and cardioplegic solution (1 g) or control group (n=15) which did not receive it. Arterial blood samples were drawn for measuring $Mg^{++}$ and electrolytes contents, blood gas analysis, CBC, total protein, albumin, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, tumor necrosis factor-${\alpha}$ $(TNF-{\alpha})$, interleukin-6 (IL-6), interleukin-10 (IL-10), creatine phosphokinase (CpK), creatine kinase-MB (CK-MB), lactate dehydrogenase(LDH), troponin-1 (TNI), prothrombin time (PT) and activated pratial thromboplastin time level (aPTT). Venous blood samples were drawn before and after the operation for measuring activated clotting time level (ACT). Result: $Mg^{++}$ levels in magensium group were higher than those of control group at intraoperative and post-operative periods (p<0.05). dysrhythmias were lower in magnesium group (8 cases out of 17 patients, 46.4%) than in control group (10 cases out of 10, 100%, p=0.050). Conclusion: These results showed that administration of low dose magnesium sulfate during cardiac surgery prevented hypomagnesemia and lowered incidence of dysrhythmia.

• Journal of Oral Medicine and Pain
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• v.35 no.2
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• pp.101-110
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• 2010

Helicobacter pylori(H. pylori) is bacterial infection, with more than half of the world population infected and oral cavity is considered second reservoir of H. pylori infection. The purpose of this study was to evaluate role of oral cavity in H. pylori infection by comparison of the mode H. pylori infection in oral cavity and stomach. We recruited 100 subjects without systemic disease including gastrointestinal disease. Samples in oral cavity taken on gingival sulcus fluid(GSF) of lower left central incisor and 1st molar, area of buccal mucosa, dorsum of the tongue, palatal and saliva. We analyzed by Nested polymerase chain reaction(PCR) for oral infection and Urea Breath Test(UBT) for gastric infection. The results were as follows : 1. Among these 100 subjects, 36(36%) were positive by Nested PCR and 33(33%) were positive by UBT(p>0.05). 2. In detection rate of H. pylori in sites taken sample, 11(11%), 8(8%), 9(9%), 3(3%), 9(9%), 7(7%) were positive on GSF of lower left central incisor and 1st molar, area of buccal mucosa, dorsum of the tongue, palatal and saliva, respectively. Statical significance was observed in samples of GSF of lower left central incisor and area of dorsum of the tongue(p<0.05). 3. In comparison of the mode of H. pylori infection in oral cavity and stomach by analytic method, positive in oral cavity and stomach was 10(10%), negative in oral cavity and positive in stomach was 23(23%), positive in oral cavity and negative in stomach was 26(26%) and negative in oral cavity and stomach was 41(41%)(p>0.05). Conclusively, we can guess that oral H. pylori is not associated with gastric H. pylori infection and normal flora.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.147-155
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• 2024

Gallium-68-prostate-specific membrane antigen-11 (⁶⁸Ga-PSMA-11) is a positron emission tomography radiopharmaceutical that labels a Glu-urea-Lys-based ligand with ⁶⁸Ga, binding specifically to the PSMA. It is used widely for imaging recurrent prostate cancer and metastases. On the other hand, the preparation and quality control testing of ⁶⁸Ga-PSMA-11 in medical institutions takes over 60 minutes, limiting the daily capacity of ⁶⁸Ge/⁶⁸Ga generators. While the generator provides 1,110 MBq (30 mCi) nominally, its activity decreases over time, and the labeling yield declines irregularly. Consequently, additional preparations are needed, increasing radiation exposure for medical technicians, prolonging patient wait times, and necessitating production schedule adjustments. This study aimed to reduce the ⁶⁸Ga-PSMA-11 preparation time and optimize the automated synthesis system. By shortening the reaction time between ⁶⁸Ga and the PSMA-11 precursor and adjusting the number of purification steps, a faster and more cost-effective method was tested while maintaining quality. The final synthesis time was reduced from 30 to 20 minutes, meeting the standards for the HEPES content, residual solvent EtOH content, and radiochemical purity. This optimized procedure minimizes radiation exposure for medical technicians, reduces patient wait times, and maintains consistent production schedules, making it suitable for clinical application.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.223.2-223.2
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• 2010

용융탄산염 연료전지(MCFC)는 $650^{\circ}C$에서 작동하는 고온형 연료전지 시스템이다. 이 시스템은 천연가스 등을 개질하여 생산된 수소를 바로 전기로 생산할 수 있는 시스템으로 열효율이 높으며, 현재 대체 발전시스템으로 각광을 받고 있다. MCFC는 개질방식에 따라 내부개질 방식과 외부개질 방식이 있다. 내부개질 방식은 수소를 생산하는 개질기가 스택내부에 장착된 형식으로 천연가스를 스택내부에서 개질하여 바로 전기를 생산하는 방식이다. 이 내부개질반응에 사용되는 촉매로는 알루미나에 담지된 니켈(Ni) 계열촉매이 주로 쓰이고 있다. 또한 내부개질촉매의 형태는 작은 원주형의 촉매형태로 성형되어 사용된다. 이 성형된 촉매의 크기가 바로 내부개질 스택의 크기를 결정하는 중요한 요소이다. 그래서 촉매의 크기는 되도록이면 작게 성형하는 것이 중요하다. 그러나 촉매의 크기가 너무 작으면 촉매를 성형하는데 큰 어려움이 생기게 된다. 본 연구에서는 니켈 촉매를 공침법이 아닌 균일용액침전법을 이용하여 제조하였으며, 이 촉매를 이용하여 지름이 약 2 mm 이하로 촉매를 압출성형하는 방법을 연구하였다. 먼저 요소(urea)를 이용한 균일용액침전법으로 촉매를 제조하였다. 최적의 촉매 합성조건을 살펴보기 위해서, 반응 온도를 80, 85, 90, 95, $100^{\circ}C$로 변화 시키면서 제조된 촉매의 특성을 살펴보았다. 그리고 촉매의 적절한 니켈 양을 알아보기 위해서 니켈의 양을 30, 40, 50, 60, 70 wt%로 변화 시켰으며, 조촉매로 사용되는 MgO 양을 5, 10, 15, 20 wt%로 변화 시켜서 제조된 촉매의 특성을 살펴보았다. 물성을 비교하기 위해서, X-선 회절분석(XRD) 및 TPR, 물리화학흡착을 하였다. 그 결과 침전반응온도가 $80^{\circ}C$에서 촉매가 가장 좋은 물성을 보였으며, 우수한 개질성능을 보였다. 그리고 촉매 활성물질인 니켈의 함량은 50 wt% 정도가 가장 적절한 함량이었으며, MgO의 함량이 15 wt%일 때 가장 우수한 물성과 개질 성능을 보여주었다. 이 촉매들은 공침법으로 제조된 상용촉매와 비교하였을 때, 보다 우수한 물성과 개질성능 보였다. 그래서 이 촉매를 균일침전법을 이용하여 대량으로 제조한 다음 압출성형 방법을 이용하여 촉매를 원주형으로 제조하였다. 먼저 제조된 촉매는 별도의 분쇄작업(볼밀 혹은 제트밀)을 거치지 않아도 입자사이즈가 약 $4{\mu}m$ 수준이 나오도록 촉매 제조조건을 조절 하였다. 그리고 소량의 Methyl cellulose(MC) 바이더와 물만 사용하여 촉매를 혼합한 다음 스크류 압출기를 이용하여 촉매를 성형하였다. 이 촉매는 지름이 약 2 mm 이하로 제조할 수 있었으며, 기계적 강도는 타정기로 성형한 상용촉매보다 우수하였다. 그리고 촉매 성능 또한 상용촉매와 비교하였을 때, 우수한 성능 보였다. MCFC용 내부개질 촉매로 균일용액침전법을 사용한 촉매가 적합하다고 판단되며, 압출성형에도 적합하다고 판단되었다.

• Journal of Animal Science and Technology
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• v.57 no.9
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• pp.35.1-35.8
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• 2015

Background: An experiment was conducted in Vietnam to test the hypothesis that total dry matter (DM) intake and liveweight (LW) gain would increase in a curvilinear manner with increasing amounts of concentrate offered. Method: There were five treatments: a basal diet of Guinea grass fed at 1 % of LW and rice straw fed ad libitum (T0), or this diet supplemented with concentrate at 0.6 (T1), 1.2 (T2), 1.8 (T3), or 2.4 % of LW (T4). The concentrate comprised locally available ingredients, namely cassava chips, rice bran, crushed rice grain, fishmeal, salt, and urea, mixed manually. Results: Concentrate intake increased from T0 to T3, but there was no difference in concentrate intake between T3 and T4. Total feed intake increased in a curvilinear manner from 4.0 to 6.4 kg DM/d as the quantity of concentrate consumed increased. The substitution of concentrate for grass and rice straw increased with increasing consumption of concentrate and was as high as 0.49 kg DM reduction per kg of concentrate consumed. LW gain increased curvilinearly, with significant differences between T0 (0.092 kg/d), T1 (0.58 kg/d) and T2 (0.79 kg/d); but there were no significant differences in LW gain between T2, T3 (0.83 kg/d) and T4 (0.94 kg/d).With increasing amount of concentrate in the diet, the digestibilities of dry matter, organic matter, crude protein, and crude fat increased, but NDF digestibility decreased. Conclusion: Based on these results, young Vietnamese Brahman-cross growing cattle will respond to a locally-sourced concentrate mix offered at a level of up to 1.2 % of LW.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.645-650
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• 1998

Alumina- and yttria-coated SiC powder was prepared by the surface-induced precipitation method, and sintered properties of silicon carbide prepared from this powder were investigated. After a well dispersion of SiC powders in the aqueous solution of $Al_2(SO_4)_3$ and $Y_2(SO_4)_3$, the mixed precursors of aluminum hydroxide, aluminum carbonate, yttrium hydroxide, and yttrium carbonate were precipitated on the surfaces of SiC particles through the hydrolysis reaction of urea. SiC specimens with alumina and yttria exhibit, 97.8% of theoretical density after the sintering at $1900^{\circ}C$ for 2 hrs. During annealing at $2000^{\circ}C$, $\beta$longrightarrow$\alpha$ phase transformation of SiC had taken place and resulted with a rodlike microstructure. Toughness of sintered SiC was enhanced by crack deflection around the rodlike grains. In case of annealing less than that of 3 hr, the fracture toughness of SiC was slightly improved with increasing the amount of sintering aid. However, annealed specimens for a long time showed constant fracture toughness even though the amount of sintering aid increased. It is resulted that the main factor for toughening in annealed SiC for a long time is the pullout effect of rodlike grains during the propagation of cracks, and the amount of sintering aids is less effective on the fracture toughness of SiC.

• Journal of Nutrition and Health
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• v.18 no.3
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• pp.201-208
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• 1985

The purpose of this study was to estimate the sodium and potassium intakes of university students in Korea and to evaluate the relationship between blood pressure and related variables. Two hundred and eighty five subjects were selected from among healthy university students aged 17 to 28. The urinary (sodium, potassium urea nitrogen and creatinine) excretions in 24 hrs. were evaluated from the analysis of urine samples gathered for 12hrs. At the same time, dietary intakes of sodium and potassium were assessed by the modified convenient method with the same subjects. The results were as follows : 1) The urinary sodium excretions of male and female students in 24hrs. were estimated at 199.1mEq and 174.5mEq respectively. Daily sodium intakes by the questionnaire were calculated to be 218.5mEq for male students and 218.1mEq for female students. 2) The urinary potassium excretions in male and female students were 48.3mEq/24hr and 43.9mEq/24hr. respectively, and the potassium intakes 48.6mEq/24hr. and 47.4mEq/24h. each 3) No correlations were found between blood pressure and the urinary excretions of sodium potassium or urinary Na/K ratio in college students.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.155-155
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• 2011

용융탄산염 연료전지(MCFC)는 $650^{\circ}C$에서 작동하는 고온형 연료전지 시스템이다. 이 시스템은 천연가스 등을 개질하여 생산된 수소를 바로 전기로 생산할 수 있는 시스템으로 열효율이 높으며, 현재 대체 발전시스템으로 각광을 받고 있다. MCFC는 개질방식에 따라 내부개질 방식과 외부개질 방식이 있다. 내부개질 방식은 수소를 생산하는 개질기가 스택내부에 장착된 형식으로 천연가스를 스택내부에서 개질하여 바로 전기를 생산하는 방식이다. 이 내부개질반응에 사용되는 촉매로는 알루미나에 고함량 (약 50 wt.%)으로 담지된 니켈(Ni) 계열촉매이 주로 쓰이고 있다. 이 고함량으로 담지된 촉매는 대부분 높은 활성을 보인다. 비교적 낮은 온도 운전조건 (약 $580{\sim}620^{\circ}C$)을 가지는 MCFC 내부개질에 적용하기 위해서는 활성점인 니켈을 최대한 담지체에 고르게 분산 시켜야한다. 이를 위해서 MgO를 이용하여 촉매의 활성점을 높게 분산시키는 연구를 진행 하였다. 촉매를 제조하는 방법으로 요소(urea)를 이용한 균일용액침전법을 이용하였다. 니켈함량은 50 wt.%로 고정을 한 다음, MgO 양과 $Al_2O_3$ 양을 각각 0 ~ 45 wt.%와 5 ~ 50 wt.%로 조절하면서 촉매를 제조하여 그 특성들을 분석하였다. 물성을 비교하기 위해서, X-선 회절분석 (XRD) 및 TPR, 물리화학흡착 실험을 하였다. 촉매의 활성을 살펴보기 위해서, fresh 상태 및 피독 상태에서 메탄수증기 개질활성 실험을 실시하였다. MgO 함량이 없거나 적은 촉매에서는 높은 BET surface area와 작은 NiO, metallic Ni 결정 크기가 나타났다. 반면 MgO 함량이 높은 촉매에서 낮은 BET surface area와 비교적 큰 NiO, metallic Ni 결정 크기가 나타났다. 또한 XRD 분석에서 MgO 함량이 증가할 수 록 MgO 결정 피크가 명확히 나타났으며, $MgAl_2O_4$ 피크는 나타나지 않았다. TPR 분석에서 촉매들의 환원 피크를 측정한 결과, 저함량의 MgO를 포함한 촉매는 $700^{\circ}C$ 부근에 환원 피크가 관찰되었고 MgO가 고함량인 촉매는 환원 피크가 $400^{\circ}C$ 부근에서 관찰되었다. 촉매의 초기 fresh 상태에서의 활성은 고함량 MgO를 포함한 Ni-90M10A 샘플을 제외하고 모든 촉매가 거의 비슷하게 나타났다. 그러나 $K_2CO_3$ 피독 상태에서는 MgO 함량이 증가할 수 록 활성이 좋지 않았음을 알 수 있었다. 따라서 MgO가 소량 포함된 촉매의 경우 fresh 상태에서는 우수한 물성과 활성을 보이지만, 피독상태에서는 MgO가 포함되지 않은 Ni-$Al_2O_3$ 촉매가 우수한 활성을 보였다.

• Toxicological Research
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• v.25 no.2
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• pp.71-78
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• 2009

We investigated the pathogenesis of liver tissue damage during the lipid peroxidation and fibrogenesis with the observation of correlations between the parameters of collagen synthesis (and deposition) and lipid peroxidation in liver fibrosis (cirrhosis) rats. Rats were randomly divided into two groups, normal and $CCl_4$-thiopental sod. intoxicated group. And the one group was treated intragastrically with the mixture of $CCl_4$-thiopental sod. 3 times per week for 3 weeks. The liver tissue and sera were used for the measurement of hydroxyproline (HYP), malonedialdehyde (MDA) and superoxide dismutase (SOD). Biochemical parameters such as aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total-bilirubin and blood urea nitrogen (BUN) were measured. Additionally, the expression of collagen ${\alpha}1$(III) and $\beta$-actin mRNA was observed by RTPCR. The histological change in liver tissue was also observed by Masson's trichrome and H&E staining. Correlation analysis was carried by Spearman's rho method. All biochemical parameters except total-bilirubin were significantly higher in the $CCl_4$-thiopental sod. treated group than that of the normal group (p < 0.01). In the $CCl_4$-thiopental sod. treated group, Hyp as a parameter of collagen synthesis (deposition) and MDA as a metabolite of lipid peroxidation, were significantly elevated by 1.98 and 2.11 times higher than that of the normal group (p < 0.001) respectively. The activity of SOD in the $CCl_4$-thiopental sod. treated group is decreased significantly by 44.8% (p < 0.001). And collagen ${\alpha}1$(III) mRNA was more expressed in the $CCl_4$-thiopental sod. treated group than that of the normal group. However, the expression of $\beta$-actin mRNA is showed similar in both of groups. A good correlation was observed between the content of hyp and MDA concentration (r = 0.70, n = 40) in the two groups. And the correlation between the levels of hyp and SOD (r = -0.71, n = 25) is also reliable. However, no correlation were observed between MDA concentration and SOD (r = -0.40, n = 25) in the two groups. Elevated levels of MDA in $CCl_4$-thiopental sod. treated rats indicated enhancement of lipid peroxidation, which is accompanied by a decrease in SOD activity. Moreover, we could confirm that the parameters of collagen synthesis (and deposition) is in good correlation with the metabolite of lipid peroxidation (MDA) and the lipid peroxidation antagonizing enzyme (SOD). Hence, we propose that (1) lipid peroxidation and collagen synthesis (and deposition) could be enhanced by intragastrically application of $CCl_4$-thiopental sod. during a short terms. And (2) the intoxication of $CCl_4$-thiopental sod. could be used for monitoring of lipid peroxidation and collagen synthesis (and deposition) for test of antioxidant and antifibrotic agent.