• Childhood Kidney Diseases
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• v.2 no.2
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• pp.125-132
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• 1998

Purpose : To study whether a low protein diet increase the efficacy of antihypertensive therapy on the progression of renal failure, we conducted an experimental study using 5/6 nephrectomized rats(n=63). Methods : At 7 days after surgery, rats were randomly assigned to three groups according to receiving antihypertensive drug: no antihypertensive drug (U), enalapril (E), and nicardipine (N), respectively and fed a low protein diet (6$\%$ protein). Proteinuria, mesangial matrix expansion score and glomerular volume were assessed at 4, 12 and 16 weeks after renal ablation. Results : Group U rats on a low protein diet developed progressive hypertension ($140{\pm}8,\;162{\pm}5,\;171{\pm}5\;and\;184{\pm}11\;mmHg$ at 4, 8, 12 and 16 weeks) which were controlled by E and N. Group U rats on a low protein diet developed proteinuria ($74{\pm}15\;mg/day$ at 16 weeks) which were decreased by E ($42{\pm}12 mg/day$) or N ($48{\pm}8 mg/day$) (p<0.05). Mesangial matrix expansion score and glomerular volume were not different between groups U, E and N on a low protein diet regardless of the antihypertensive drugs administered. Conclusion : A low protein diet did not affect blood pressure. Enalapril and nicardipine-treated rats on a low protein diet did not have different mesangial matrix expansion and glomerular volumes from rats on a low protein diet at 12 weeks and 16 weeks, in spite of the better controlling of systemic hypertension and lessening of proteinuria. Thus, combined treatment with a low protein diet and antihypertensive drugs didn't appear to show any addition,11 effects to attenuate glomerular injury.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.138-144
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• 1998

Purpose : The use of cyclosporine and mitomycin in various immunologic or neoplastic disorders has been known to cause wide-ranged nephrotoxic effects including thrombotic microangiopathy. However, the mechanism of nephrotoxicity of these drugs has not been studied adequately, so that present experimental study has been undertaken to find out whether these drugs can cause direct damage to the kidney and to clarify the pathogenetic mechanism of nephrotoxic effect of these drugs. Materials and methods : Sprague-Dawley rats weighing 250-300 gm were used for experimental animals and unilateral renal perfusion technique, modified from the method described by Hoyer et al was used. Isolation of left kidney from systemic circulation was made by clamping aorta and left renal vein and a hole was punctured in the anterior wall of the left renal vein. Cyclosporine (2.5 mg in 4 ml solution) and mitomycin (1.6 mg in 4ml solution) were infused through left renal artery and normal saline was used in control rats. Forty-eight hours after infusion of the drugs, animals were sacrificed and left kidney removed and processed for histologic examination. Total ischemic time of left kidney was less than 15 minutes: Results : Cyclosporine-perfused group showed severe swelling of glomerular endothelial ceil along with swelling of glomerular epithelial cell and interstitial vascular endothelial cell. Mitomycin-perfused group also showed severe swelling of glomerular endothelial and epithelial cells. And in addition to these findings, they demonstrated platelets aggregation, swelling and degranulation of platelets and fibrin accumulation in some of the capillaries, indicating occurrance of thrombotic microangiopathy. Conclusion : present experiment indicates that cyclosporine and mitomycin can cause direct toxic injury to renal endothelial cell. And this direct toxic damage to endothelial cell seems to be an important initiating event for the development of thrombotic microangiopathy.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.44-48
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• 2017

Purpose Estradiol (E2) is a steroid hormone mainly produced in women and is a useful indicator for diagnosis of gynecological diseases, menstrual cycle, menopause, and precocious puberty. E2 measurement is performed by diluting the $^{125}I$ radioactive tracer and tracer buffer in the kit. However, It was not precisely specified when the period of tracer is available after activating. The purpose of this study was to determine the appropriate dilution time based on the measurement value with dilution time. Materials and Methods From December 2016 to February 2017, 60 E2 samples with concentrations ranging from 8 to 4577 pg/mL were divided into low, medium, and high concentrations. Dilution of the $^{125}I$ tracer was performed on a 230 RPM agitator for 30 minutes, 1 hour 30 minutes, and 2 hours 30 minutes, respectively. 24 hour dilution was gently shaken and refrigerated. To verify the difference and significance of the results according to the dilution time, a test of normality was performed using SPSS 18.0 and analyzed by Kruskal-Wallis test. The measured value according to the dilution time was compared with the interquartile range of the absolute error. Results The results of Kruskal-Wallis test were not significant (P>0.05). Measurement results are showed as interquartile range of absolute error. At low concentration, it is 0.052 between 1 hour 30 minutes and 2 hours 30 minutes, and 0.105 between 30 minutes and 1 hour 30 minutes. At medium concentration, 0.062 between 30 minutes and 1 hour 30 minutes, and 0.038 between 1 hour 30 minutes and 2 hours 30 minutes. At high concentration, it is 0.029 between 1 hour 30 minutes and 2 hours 30 minutes, and 0.06 between 2 hours 30 minutes and 24 hours. Conclusion There were no statistically significant differences. However, the change in the measured value is the smallest between 1 hour and 30 minutes to 2 hours and 30 minutes. Therefore, we recommend diluting time between 1 hour 30 minutes and 2 hours 30 minutes.

• Korean Journal of Organic Agriculture
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• v.24 no.2
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• pp.235-251
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• 2016

After carrying out on-the-spot observation targeting each farmhouse of large-scale environment-friendly agricultural district (LEAD), Suncheon, Sancheong, Jangheung, Yeongam, Hamyang, Okcheon, and Jeongseon in 2015, only one LEAD, a farmhouse in Jangheung had used sustainable compost coming out under their own non-antibiotic livestock. The soil pH and EC at a depth of 0-20 cm in the seven LEADs were ranged between 5.3-6.6 and $0.4-1.2dS\;m^{-1}$, respectively, with 0.03- 0.27% for T-N concentration, $22-322mg\;kg^{-1}$ for P, and $0.05-0.29mg\;kg^{-1}$, which were, in particular, low a farmhouse in Jeongseon. When intensively surveying on each farmhouse of Suncheon, Jangheung, and Okcheon for a growing period, seasonal soil pH was maintained above 6.0 and high in a farmhouse in Okcheon, with similar soil EC observed among the three LEADs. Seasonal soil T-N was 0.1% higher on the farmhouse in Suncheon than other two LEADs, with higher seasonal soil P observed on the farmhouse in Okcheon and higher soil K in the Jangheung. T-N concentration in rice (Oryza sativa L.) crops was the highest in Jangheung, and concentrations of T-N, P, and K decreased in a season. Plant height and number of tillers per hill were the highest on the farmhouse in Okcheon, where was similar or low plant diameter and SPAD levels compared to other two LEADs. Dry weight (DW) before harvest was ranged between 52-63 g, and DW, rough rice yield (kg), brown rice/rough rice (%), brown rice yield (kg), head rice (%), and broken rice (%) were not significantly different among the three LEADs. Total annual gross production ha-1 was the highest on the farmhouse in Okcheon (16,230,000 won) planting with high class of variety, 'Milky queen' at early maturation, which was expected to be increased on an agricultural income. However, high amount of fertilizer was applied for growing the following crops on the farmhouse in Okcheon, affecting the highest balance of T-N, P, and K more than $200kg\;ha^{-1}$.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.851-860
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• 2015

The objective of this study was to manufacture the wood based roughage using lumber from thinning of oak and pitch pine (Pinus rigida). And the study also aimed to investigate a feed value evaluation of wood based roughages. To investigate the optimization condition of steam-digestion treatment for roughage, the wood chips of oak and pitch pine were steam-digestion treated at $160^{\circ}C$ under pressure 6 atm depending on treatment times (60 min, 90 min and 120 min) followed by the content of essential oils analyzed. The essential oil content of steam-digestion treated roughages for 90 min and 120 min were under 0.1 mL/kg. The evaluation of feed value was carried out from steam-digestion treated roughages for 90 min through feed chemical composition analysis, NRC (National research Council) modeling, ruminal degradability analysis and relative economic value analysis. The feed chemical compositions including DM (dry mater), CP (crude protein), EE (ether extract), NDF (neutral detergent fiber), ADF (acid detergent fiber), ADL (acid detergent lignin), NFC (nonfiber carbohydrate) in oak roughage were 95.4, 1.36, 3.11, 90.05, 83.85, 17.33, 6.50%, respectively, and in pitch pine roughage were 94.37, 1.33, 5.48, 87.89, 86.88, 30.56, 6.32%, respectively. Both roughages showed low level of protein and very high level of NDF. The TDN (total digestible nutrient) levels using NRC (2001) model in oak and pitch pine roughages were 40.55, 31.22%, respectively. The ruminal in situ dry matter degradability was higher in oak roughage (23.84%) than in pitch pine roughage (10.02%). The economic values of oak and pitch pine rough-ages were 235, and 210 \, respectively.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.520-527
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• 2008

Purpose: This study was conducted to evaluate the shear bond strength of composite resin to dentin when etched with laser instead of phosphoric acid. Material and methods: Recently extracted forty molars, completely free of dental caries, were embedded into acrylic resin. After exposing dentin with diamond saw, teeth surface were polished with a series of SiC paper. The teeth were divided into four groups composed of 10 specimens each; 1) no surface treated group as a control 2) acid-etched with 35%-phosphoric acid 3) Er:YAG laser treated 4) Er,Cr:YSGG laser treated. A dentin bonding agent (Adapter Single Bond2, 3M/ESPE) was applied to the specimens and then transparent plastic tubes (3 mm of height and diameter) were placed on each dentin. The composite resin was inserted into the tubes and cured. All the specimens were stored in distilled water at $37^{\circ}C$ for 24 hours and the shear bond strength was measured using a universal testing machine (Z020, Zwick, Germany). The data of tensile bond strength were statistically analyzed by one-way ANOVA and Duncan's test at ${\alpha}$= 0.05. Results: The bond strengths of Er:YAG laser-treated group was $3.98{\pm}0.88$ MPa and Er,Cr:YSGG laser-treated group showed $3.70{\pm}1.55$ MPa. There were no significant differences between two laser groups. The control group showed the lowest bond strength, $1.52{\pm}0.42$ MPa and the highest shear bond strength was presented in acid-etched group, $7.10{\pm}1.86$ MPa (P < .05). Conclusion: Laser-etched group exhibited significantly higer bond strength than that of control group, while still weaker than that of the phosphoric acid-etched group.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

• Journal of Aquaculture
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• v.4 no.2
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• pp.111-128
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• 1991

In puan area the environmental surveys were carried out at two farms of hard clam, Meretrix lusoria from April 1987 to November 1978 in order to know heather the farm environments could be rehabilitated for the cultivation of hard clam or not. The range of temperature of surface seawater was $10.7{\~}27.4^{\circ}C$, pH $7.6{\~}8.2$, salinity $22.3{\~}30.3$ ppt, COD $0.20{\~}4.71\;mg/{\ell}$, sulfide $0.04{\~}0.22\;{\mu}g-at./{\ell}$, suspended solid $34.8{\~}199.3\;mg/{\ell}$ chlorophyll a $3.71{\~}49.02\;mg/m^3$, TIN $2.01{\~}24.47\;{\mu}g-a5./{\ell}$, phosphate $0.60{\~}11.03\;{\mu}g-at./{\ell}$ and silicate $4.04{\~}476.36\;{\mu}g-at./{\ell}$. The range of temperature of substratum (bottom soil) was $14.2{\~}29.7^{\circ}C$, pH $8.3{\~}9.5$, water content of substratum was $0.28{\~}0.49\;mg/g$ dried mud, COD $2.80{\~}50.94\;mg/g$ dried mud, total organic matter $1.05{\~}1.97\%$ concentration of total Kjedhal nitrogen $31.9{\~}194.9\;{\mu}g./{\ell}$ dried mud, and sulfide $0.032{\~}0.133\;mg/g$ dried mud. Fine sand was dominant ranging over $92{\~}95\%$ and silt and clay was $2.8{\~}8.1\%$ of the composition of substratum. Some residual agricultural chemicals, ${\alpha},\;{\beta},\;{\gamma}$-BHC, heptachlor, heptachlor-epoxide, aldrin, DDE, DDT and dieldrin were detected in hard clams collected from Puan areas. Especialy, more chemical were detected during the period of rainfalls. From above results, it is considered that the hard clam frams were not yet recovered from deteriorated conditions for aquaculture.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1197-1203
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• 2013

This study investigated the effects of endurance exercise and ginsenoside $Rb_1$ on AMP-activated protein kinase (AMPK), phosphatidylinositol 3-kinase (PI3K) protein expression and glucose uptake in the skeletal muscle of rats. A total of 32 rats were randomly divided into four groups: CON (Control group, n=8), Ex (Exercise group; 25 m/min for 1 h, 6 days/week, 2 weeks, n=8), $Rb_1$ (Ginsenoside $Rb_1$ group; n=8), and $Rb_1/Ex$ ($Rb_1$+Exercise group, n=8). The $Rb_1$ and $Rb_1/Ex$ groups were incubated in ginsenoside $Rb_1$ (KRBP buffer, $100{\mu}g/mL$) for 60 min after a 2-week experimental treatment. After 2 weeks, the expression of phosphorylated $AMPK{\alpha}$ $Thr^{172}$, total $AMPK{\alpha}$, the p85 subunit of PI3K, pIRS-1 $Tyr^{612}$, and pAkt $Ser^{473}$ were determined in the soleus muscle. Muscle glucose uptake was measured using 2-deoxy-D-[$^3H$] glucose in epitroclearis muscle. Muscle glucose uptake was significantly higher in the three experimental groups (Ex, $Rb_1$, $Rb_1/Ex$) compared to the CON group (P<0.05). The expression of $tAMPK{\alpha}$ and $pAMPK{\alpha}$ $Thr^{172}$ was significantly higher in the Ex, $Rb_1$, and $Rb_1/Ex$ groups compared to the CON group (P<0.05). The expression of pAkt $Ser^{473}$ was significantly higher in the $Rb_1$ group compared to the CON and EX groups. However, the expression of pIRS-1 $Tyr^{612}$ and the p85 subunit of PI3K were not significantly different between the four groups. Overall, these results suggest that ginsenoside $Rb_1$ significantly stimulates glucose uptake in the skeletal muscle of rats through increasing phosphorylation in the AMPK pathway, similar to the effects of exercise.

• Neonatal Medicine
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• v.18 no.1
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• pp.89-95
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• 2011

Purpose: Hypernatremia most frequently occurs in the immature newborn and be severe in association with intraventricular hemorrhage (IVH). This study examined the frequency, onset and risk factors of hypernatremia, and the relationship between hypernatremia and IVH in very low birth weight (VLBW; <1,250 g) infants. Methods: We retrospectively reviewed the medical records of 55 VLBW infants admitted between January 2006 and December 2009 to the neonatal intensive care unit of Wonkwang University Hospital and who survived over 7 days. Serum sodium concentration, sodium intake, fluid and weight loss, as suggested risk factors of hypernatremia, and the incidence of IVH were evaluated. The infants were divided into a hypernatremia group (${\geq}$150 mEq/L) and nonhypernatremia group, and were compared. Results: Incidence of hypernatremia in the VLBW infants was 52.7%, and mean starting time of hypernatremia was 2.8${\pm}$1.3 days. There were no differences in the sodium and fluid intake between the two groups. Weight loss at day 3 after birth was significantly higher in the hypernatremia compared to the nonhypernatremia group (P<0.05); thereafter weight loss was non-significantly higher. The incidence of IVH in VLBW infants was 38.2%, and the difference between the two groups was not significant. Conclusion: Hypernatremia occurs commonly in VLBW infants and is most commonly caused by weight loss in the early days after birth. Incidence of IVH is not likely influenced by hypernatremia with marginally elevated sodium concentration.