• Proceedings of the Korean Society of Veterinary Pathology Conference
• /
• 2002.11a
• /
• pp.148-148
• /
• 2002

수분부족 및 hyperoxaluria가 유도된 랫드에서 enrofloxacin 투여로 인한 신장손상을 알아보기 위하여 본 실험을 실시하였다. 랫드는 모두 4 그룹으로 나누어 실험에 공하였다. 실험은 72시간 탈수를 유발시킨 랫드 (Group 1), 3％ sodium oxalate를 음수로 7 일간 급여해서 hyperoxaluria 상태를 유발시킨 랫드 (Group 2, 3) 그리고 sodium oxalate 30mg/Kg을 1회 복강내 투여로 급성 hyperoxaluria 상태를 유발시킨 랫드(Group 4)에 각각 enrofloxacin을 용량별 (0mg/Kg, 50mg/Kg, 500mg/Kg)로 1일 혹은 7일 동안 투여한 후 임상 및 병리조직학적 소견을 추구하였던 바 다음과 같은 결과를 얻었다. 수분부족이나 hyperoxaluria 가 유도된 상태의 전 그룹에서 enrofloxacin 투여용량이 증가할수록 식욕감소, 음수량 감소, 행동둔화 등의 임상증상과 사구체의 손상, 신장피질내 충혈, 세뇨관의 변성, 공포화, 괴사 등의 변화가 현저히 진행되는 것을 알 수 있었고, Group 2, 3, 4 실험군의 소변을 원심분리하여 침전된 뇨침사를 현미경으로 검사한 결과 모든 군에서 calcium oxalate crystal이 검출되었고 일부는 magnesium ammonium phosphate crystal이 검출되었다. 이상의 결과를 종합해 볼 때, 탈수상태나 혈중 oxalate함량이 높은 랫드에서 enrofloxacin의 투여는 신장에 손상을 주어 결석을 형성할 수도 있는 것으로 사료되며 이러한 개체에서 enrofloxacin의 사용상 주의가 요구된다.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.1
• /
• pp.129-129
• /
• 2003

본 연구는 음식물 퇴비의 합리적인 시용량을 검증하고, 3년 연용에 의한 토양 변화 및 고추 생육과 수량에 미치는 영향을 평가하고 돈분퇴비를 시용한 대조구와 생육 및 품질 면에서 비교 분석하여 적정한 퇴비 시용량을 설정하기 위하여 실시하였다. 처리구는 1, 2, 3차 연도 모두 동일한 방법으로 무처리구, 대조구(2ton/10a의 돈분퇴비), 음식물 퇴비 2t, 4t, 6t, 8ton/10a을 사용한 처리구 등 6개를 두었으며 3반복, 난괴법을 이용하였다. 음식물 퇴비와 돈분 퇴비의 이화학적 특성을 분석한 결과, 음식물 퇴비의 경우 1차 연도는 유기물과 NaCl 모두 부산물 비료의 공정규격에 적합하였으나, 2차 연도는 유기물이, 3차 연도는 NaCl이 공정규격에 적합하지 않았다. 그리고 돈분 퇴비의 경우 수분함량이 약간의 차이를 보였으나 공정규격을 벗어나지는 않았다. 토양은 음식물 퇴비 시용량이 증가할수록 대부분의 화학적 특성이 증가하였고, 연용에 의해서도 유기물, 치환성양이온, NaCl 등의 양이 증가함을 보여 염류집적이 일어나고 있음을 확인할 수 있었다. 또, 음식물 퇴비 시용량증가에 따라 비중은 낮아지고 공극률이 증가하여 물리성 개선에 도움을 주었으나, 1, 2, 3차 연도를 비교해 보았을 때 큰 차이는 없었다. 고추의 생육과 수량에 있어서도 음식물 퇴비 시용량이 증가할수록 초기 생육이 저조하였으며, 그로 인해 수량이 감소하였다. 또한 3년 연용으로 인한 음식물 퇴비의 축적으로 수량의 감소와 품질 저하를 초래하였다. 음식물 퇴비의 연용에서 2ton/10a 이상의 시용은 수량의 감소를 초래하였다. 이러한 결과로 볼 때 음식물 퇴비를 2ton/10a 이하로 사용하면 큰 무리는 없겠지만 장기 연용은 삼가는 것이 좋을 것이라 판단된다. 따라서 음식물 퇴비를 다른 일반 퇴비 제조의 중간 원료나, 또는 혼합 사용하는 시험을 계속 진행 중에 있다.

• Journal of Chest Surgery
• /
• v.31 no.9
• /
• pp.837-844
• /
• 1998

Background: Adenosine is secreted by myocardial cells during myocardial ischemia or hypoxia. It has many beneficial effects on arrhythmias, myocardial ischemia, and reperfusion ischemia. Although many investigators have demonstrated that cardioplegia that includes adenosine shows protective effects in myocardial ischemia or reperfusion injury, reports of the optimal dose of adenosine in cardioplegic solutions vary. We reported the results of beneficial effects of single dosage(0.75 mg/Kg/min) adenosine by use of self-made Langendorff system. But it is uncertain that dosage was optimal. The objective of this study is to determine the optimal dose of adenosine in cardioplegic solutions. Material and Method: We used a self-made Langendorff system to evaluate the myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas' Hospital cardioplegia including adenosine. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegia. Three groups of hearts were studied: (1) group 1 (n=10) : adenosine - 0.5 mg/Kg/min, (2) group 2(n=10): adenosine -0.75 mg/Kg/min, (3) group 3 (n=10) : adenosine -1 mg/Kg/min. Result: Group 3 resulted in a significantly rapid arrest time of the heart beat(p<0.05) but significantly slow recovery time of the heart beat after reperfusion(p<0.05) compared to groups 1 and 2. Group 2 showed a better percentage of recovery(p<0.05) in systolic aortic pressure, aortic overflow volume, coronary flow volume, and cardiac output compared to groups 1 and 3. Group 1 showed a a better percentage of recovery(p<0.05) in the heart rate compared to the others. In biochemical study of drained reperfusates, CPK and lactic acid levels did not show significant differences in all of the groups. Conclusion: We concluded that group 2 [adenosine(0.75 mg/Kg/min) added to cardioplegia] has better recovery effects after reperfusion in myocardial ischemia and is the most appropriate dosage compared to group 1 and 3.

• Journal of the Korean Electrochemical Society
• /
• v.4 no.3
• /
• pp.94-97
• /
• 2001

Electro-conducting Polypyrrole(PPy) films were Prepared by applying constant current in various electrolytes solutions and their capacitance properties were investigated using cyclic voltammetry. Capacitance values were strongly dependent on the electrolytes solution used in electrochemical polymerization. PPy prepared in PC/AN mixture solution containing 0.5M $LiClO_4$ with small amount water showed 401 F/g and that electrogenerated in $AN/H_2O$ mixture solution containing 0.5M $LiClO_4$ retained $70\%$ of initial capacitance after 2000 cycles.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.02a
• /
• pp.320-321
• /
• 2000

전기장 발광현상(Electroluminescence, 이하 EL)은 1936년 Destriau$^{[1]}$ 가 ZnS:Cu 분말에서 처음 전기장 발광현상을 발견한 이래 TFEL(Thin Film EL)소자의 구동전압을 감소시키는 문제는 ACTFEL(Alternating Current Thin Film EL)소자의 개발이후 계속적인 관심의 대상이 되어왔다. TFEL 소자는 전기적으로 용량소자이므로 전기장 인가시 각 층의 정전용량의 역수에 비례하는 전압이 분배되므로 동일한 조건의 형광막 사용시 소자의 구동전압을 낮추기 위해서는 절연박막의 두께를 줄이는 방법과 유전율이 높은 물질을 사용하는 방법이 있으나, 전자의 경우에는 박막의 결함이 생기기 쉬워 한계가 있기 때문에 고유전율 특성을 갖는 새로운 물질을 개발하는 것이 바람직하다. Ta$_2$O$_{5}$ 박막의 경우 작은 누설전류 특성과 고유전율 특성으로 인해 고집적을 요하는 반도체 분야에서 많은 연구가 진행되어 왔다. 또한 EL소자 응용시 효율면에서 우수한 특성이 기대되며, 특히 수분에 강한 특성을 가지고 있어 EL소자의 안정성이 예견되는 바이다. 본 연구에서는 Ta$_2$O$_{5}$ 박막의 산소 결핍에 따른 전기적 특성에 대해 연구하였고 Ta$_2$O$_{5}$ 박막을 이용한 저전압에서 구동가능한 전기장 발광소자를 제작하여 전기광학적 특성에 대해 연구하였다. (중략

• Korean Journal of Plant Resources
• /
• v.27 no.5
• /
• pp.546-555
• /
• 2014

The final aim of this study is to develop a biofiltration system integrated with plant vegetation for improving indoor air quality effectively depending on indoor space and characteristics. However, to approach this final goal, several requirements such as constant pressure drops (PDs) and soil moisture contents (SMCs), which influence the capacity design for a proper ventilation rate of biofiltration system, should be satisfied. Thus, this fundamental experiment was carried out to adjust a proper wind speed and to ensure a stabilization of initial SMCs within biofilter for uniform distribution of SMCs and PDs, and for normal plant growth, especially avoiding root stress by wind. Therefore, we designed horizontal biofliter models and manufactured them, and then calculated the ventilation rate, air residence time, and air-liquid ration based on the biofilter depending on three levels of wind speed (1, 2, and $3cm{\cdot}s^{-1}$). The relative humidity (RH) and PD of the humidified air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of lettuce and duffy fern grown within biofilter were measured depending on the three levels of wind speed. As a result of wind speed test, $3{\cdot}sec^{-1}$ was suitable to keep up a proper RH, SMC, and plant growth. Thus, the next experiment was set up to be two levels of initial SMCs (low and high initial SMC, 18.5 and 28.7%) within each biofilter operated and a non-biofiltered control (initial SMC, 29.7%) on the same wind speed ($3cm{\cdot}sec^{-1}$), and measured on the RH and PD of the air coming out through the soil within the biofilter, and SMC of the soil and plant growth parameters of Humata tyermani grown within biofilter. This result was similar to the first results on RHs, SMCs, and PDs keeping up with constant levels, and three SMCs did not show any significant difference on plant growth parameters. However, two biofiltered SMCs enhanced dry weights of the plants slightly than non-biofiltered SMC. Thus, the stability of this biofiler system keeping up major physical factors (SMC and PD) deserved to be adopted for designing an advanced integrated biofilter model in the near future.

• Journal of Dairy Science and Biotechnology
• /
• v.34 no.2
• /
• pp.117-135
• /
• 2016

The present study was performed to develop a functional raw food material from hydrolyzed whey protein powder (23%-GNANA) medication containing sialic acid as a marker compound that is naturally occurring at 7% concentration in GMP (glycomacropeptide). GMP is used worldwide in foodstuffs for babies and infants and is obtained from the milk protein as safe food. While the purpose of our detailed evaluation was aimed to assess preliminary NOAEL values for and above 2,000 mg/kg/day, a clinical dose allowance for 23%-GNANA (as per characteristic of a functional health product, a highly refined test substance of 23% (v/v) sialic acid combined in GMP), at the same time we also wanted to assess the safety of GMP hydrolyzate lacking sialic acid but with identical properties as GMP. Animal safety evaluation was conducted using 23%-GNANA as the test substance, produced from hydrolyzed whey protein powder (product name: HELICOBACTROL-23; provided by Medinutrol Inc. [Korea]; composed of 23% sialic acid and GMP protein) after isolating the sialic acid using enzymes approved as food additives, with GMP as a raw material, and subsequently increasing the content of xx up to 23% through 80% (v/v) ethanol soaking and concentrating, in accordance with GLP Guideline. The animal safety evaluation mentioned above was made on the basis of toxicity in SPF Sprague-Dawley female and male rats dosed with 10 mL of the test substance diluted to 0, 1,250, 2,500, and 5,000 mg/kg directly into their stomachs for 90 d. This was determined in terms of the general symptoms and animal viability, weight and amount of feed intake, eye examination, uracrasia tests, hematological and blood biochemical disorder tests, blood coagulation test, abnormal intestine weight, abnormalities during postmortem and histopathological examinations. Statistical significance was set at P<0.05. Based on the toxicity determination, a certain minor effect associated with the test substance was observed in male rats with no major effects of the tested substance, in comparison with the control group dosed with sterilized water. Nevertheless, the NOAEL value, evaluated as per toxicity criteria, was verified as 5,000 mg/kg/day (P<0.05). Similarly, for female rats, a certain minor effect associated with the test substance was observed in 5,000 mg/kg/day dosed group, with no major effect, yet the NOAEL value (as assessed as per toxicity criteria) was determined to be 5,000 mg/kg/day (P<0.05), which was the same as for male rats. Accordingly, the NOAEL values of the test substances for all female and male rats were finally verified as 5,000 mg/kg/day (P<0.05). In conclusion, it was determined that the 23%-GNANA test substance exceeds 2,000 mg/kg/day, the clinical allowance characteristic for functional health food, and was finally evaluated to cause no safety concerns when used as a raw material in functional health food production, which was the ultimate goal of the present study.

• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.1
• /
• pp.30-34
• /
• 1984

A pot experiment was conducted to investigate the dry matter weight of soybean plant, fertilization efficiency, and the changes of p uptake with different p application levels in cultivated and uncultivated soils controlling the soil moisture content to 2 levels. 1. The effect of irrigation was higher in cultivated soil than in uncultivated soil, and was higher in larger amount of p application than in small amount of p. 2. Efficiency of phosphate fertilization for soybean growth was higher in cultivated soil compared with uncultivated soil, and increased by irrigation to optimum soil moisture content for crop growth. 3. Adjustment of soil moisture content to optimum level for soybean growth increased the concentration of phosphate in plant and decreased the content of phosphate in soil. Therefore, it was obvious that soybean plant absorbed the high amount of p in the optimum soil moisture level and in large amount of p application.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.3
• /
• pp.159-164
• /
• 1991

A field microplot(D 20cm, L 85cm) experiment filled with Bonryang sandy loam soil (Typic Udifluvents) was conducted to obtain quantitative information on the movement of applied nutrients under diffetent soil moisture regimes and ladino clover cultivation. Chloride moved rapidly with soil water. When soil moisture tension was maintained at loer than 0.2 bar most of the Cl appeared to move outside the microplot 4 month after the microplot installation. Regardless of soil moisture condition, Cl was not detected in the soil due to the fast movement of the Cl beyond the microplot after 5.5 months Although large amount of P and water were applied to the soil of high available P during the field experiment, movement of P was negligible and most of P remained in thc place where applied due to the low solubility of the fused and superphosphate. Phosphate in the soil extracted by Bray No.1 solution and taken up by plant increased with soil moisture. Under the condition of irrigation at 0.2 bar, plant took up 23% of the applied P, and 24% of the P was extracted by Bray NO.1 solution, while plant took up 14% and 13% of the P was turned out to be Bray No.1 P. at thc nonirrigated condition after final harvest.

• Journal of the Korea Concrete Institute
• /
• v.14 no.6
• /
• pp.813-822
• /
• 2002

The purpose of the present study is first to refine the mathematical material models for moisture and temperature distributions in early-age concrete and then to incorporate those models into finite element procedure. The three dimensional finite element program developed in the present study can determine the degree of hydration, temperature and moisture distribution in hardening concrete. It is assumed that temperature and humidity fields are fully uncoupled and only the degree of hydration is coupled with two state variables. Mathematical formulation of degree of hydration Is based on the combination of three rate functions of reaction. The effect of moisture condition as well as temperature on the rate of reaction is considered in the degree of hydration model. In moisture transfer, diffusion coefficient is strongly dependent on the moisture content in pore system. Many existing models describe this phenomenon according to the composition of mixture, especially water to cement ratio, but do not consider the age dependency. Microstructure is changing with the hydration and thus transport coefficients at early ages are significantly higher because the pore structure in the cement matrix is more open. The moisture capacity and sink are derived from age-dependent desorption isotherm. Prediction of a moisture sink due to the hydration process, i.e. self-desiccation, is related to autogenous shrinkage, which may cause early-age cracking in high strength and high performance concrete. The realistic models and finite element program developed in this study provide fairly good results on the temperature and moisture distribution for early-age concrete and correlate very well with actual test data.