• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.25-32
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• 2012

Cold start driving cycles exhibit an increases in friction losses due to the low temperatures of metal components and media compared to the normal operating engine conditions. These friction losses are adversely affected to fuel economy. Therefore, in recent years, various techniques for the improvement of fuel economy at cold start driving cycles have been introduced. The main techniques are the upward control of coolant temperature and the fast warm-up techniques. In particular, the fast warm-up techniques are implemented with the coolant flow-controlled water pump and the WHRS (waste heat recovery system). This paper deals with an effect of fast ATF (automatic transmission fluid) warm-up on fuel economy using a recovery system of EGR gas waste heat in a diesel engine. On a conventional diesel engine, two ATF coolers have been connected in series, i.e., an air-cooled ATF cooler is placed in front of the condenser of air conditioning system and a water-cooled one is embedded into the radiator header. However, the new system consists of only a water-cooled heat exchanger that has been changed into the integrated structure with an EGR cooler to have the engine coolant directly from the EGR cooler. The ATF cooler becomes the ATF warmer and cooler, i.e., it plays a role of an ATF warmer if the temperature of ATF is lower than that of coolant, and plays a role of an ATF cooler otherwise. Chassis dynamometer experiments demonstrated the fuel economy improvement of over 2.5% with rapid increase in the ATF temperature.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.5
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• pp.305-314
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• 2005

Diabetes mellitus is associated with vascular complications, including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive substances in various vasculature. In the present study, the authors have observed endothelin-B ($ET_B$) receptor agonist-induced relaxation in precontracted mesenteric arterial segments from streptozotocin (STZ)-induced diabetic rats, which was not shown from control rats or in other arterial segments from diabetic rats. Accordingly, the goal of this study was to investigate in what way STZ-induced diabetes altered reactivity of the mesenteric arterial bed and to examine the causal relaxation, if any, between this $ET_B$ receptor-mediated relaxation and endothelial paracrine function, especially nitric oxide (NO) production. The relaxation induced by $ET_B$ agonists was not observed in mesenteric arteries without endothelium. The relaxation to $ET_B$ agonists was completely abolished by pretreatment with BQ788, but not by BQ610. $N_{\omega}-nitro-L-arginine$ methyl ester and soluble guanylate cyclase inhibitors, methylene blue or LY83583 significantly attenuated the relaxant responses to $ET_B$ agonists, respectively. When the expression of eNOS and iNOS was evaluated on agarose gel stained with ethidium bromide, the expression of eNOS mRNA in diabetic rats was significantly decreased, but the expression of iNOS was increased compared with control rats. Furthermore, the iNOS-like immunostaining was densely detected in the endothelium and slightly in the arterial smooth muscle of diabetic rats, but not in control rats. These observations suggest that $ET_B$ receptor may not play a role in maintaining mesenteric vascular tone in normal situation. However, the alterations in $ET_B$ receptor sensitivity were found in diabetic rats and lead to the $ET_B$ agonist-induced vasorelaxation, which is closely related to NO production. In the state of increased vascular resistance of diabetic mesenteric vascular bed, enhanced NO production by activation of iNOS could lead to compensatory vasorelaxation to modulate adequate perfusion pressure to splanchnic area.

• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.355-361
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• 1986

Vibrio vulnificus, a halophilic Vibrio has gained worldwide attention as a cause of severe and frequently fatal wound infections and life-threatening septicemia. For this reason V. vulnificus is thought to produce extreme hemoconcentration and rapid death after infection, and because V. vulnificus is thought to be less susceptible to bactericidal activity of normal human serum, the present study was undertaken to assess the susceptibility of V. vulnificus to human serum bactericidal activity with that of V. parahemolyticus and V. cholerae and to assess the effect of Vibrio species, Salmonella typhimurium and E. coli on hematocrit values in experimentally infected mice. Serum bactericidal activity against both V. vulnificus and V. cholerae was higher than against V. parahemoltyicus. Survival of the test strains in heat-inactivated human serum was greater than that in heat-uninactiveted serum. Both V. parahemolyticus and V. cholerae produced slight hemoconcentration within 2 to 6 hr after intraperitoneal injection of $10^7$ viable bacteria into mice. In contrast, V. vulnificus, S. typhimurium and E. coli produced hemodilution rather than hemoconcentration after 4 or 6 hr after infection. With these results the author can conclude that V. vulnificus is more susceptible to serum bactericidal activity than other Vibrio species, and V. vulnificus did not produce hemoconcentration.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.3
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• pp.105-137
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• 2008

Objectives : The purpose of this study is to investigate the effect of Gupoongjeseuptang (GPJST) on atopic dermatitis by in vivo experiment using NC/Nga atopic dermatitis mouse, which has histological and clinical similarities to the atopic dermatitis of human. Methods : To investigate the effect of GPJST on atopic dermatifis, we evaluated atopic dermatitis-like skin lesions by clinical skin index and analyzed immunological parameters in peripheral blood mononuclear cells (PBMCs), splenocytes, draining lymph node (DLN) and performed skin histology in ears and dorsal skin of atopic dermatitis-like skin NC/Nga mouse in vivo. Results : In vivo, clinical skin severity score were significantly lower in GPJST group than control group. IgE, IL-6, $TNF-{\alpha}$, IgG1, IgM, IgG2a and IgG2b levels in serum decreased remarkably in GPJST group than control group. Also, total absolute number of $CD3^+CD69^+$, and $CCR3^+$ cells recovered as normal in PBMCs and $CD3^+$, $CD3^+CD69^+$ decreased significantly compared with control group in isolated DLN from NC/Nga mouse and total absolute number of $CD11b^+Gr-1^+$, $CCR3^+CD3^+$ in dorsal skin of NC/Nga mouse decreased by GPJST. We analyzed ear and neck-back skin after biopsy and dyeing by hematoxyline/eosin (H&E) and toluidine staining (mast cells marker) and obtained results that GPJST are very effective to histological symptoms (dermal and epidermal thickening, hyperkeratosis and inflammatory cell (CD4, $CCR3^+$) infiltration). Conclusions : This study demonstrates immunological activity of GPJST on atopic dermatitis-like model mice.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.116-124
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• 2013

Purpose: Tumor necrosis factor (TNF)-${\alpha}$ is thought to contribute to pulmonary hypertension. We aimed to investigate the effect of infliximab (TNF-${\alpha}$ antagonist) treatment on pathologic findings and gene expression in a monocrotaline-induced pulmonary hypertension rat model. Methods: Six-week-old male Sprague-Dawley rats were allocated to 3 groups: control (C), single subcutaneous injection of normal saline (0.1 mL/kg); monocrotaline (M), single subcutaneous injection of monocrotaline (60 mg/kg); and monocrotaline + infliximab (M+I), single subcutaneous injection of monocrotaline plus single subcutaneous injection of infliximab (5 mg/kg). The rats were sacrificed after 1, 5, 7, 14, or 28 days. We examined changes in pathology and gene expression levels of TNF-${\alpha}$, endothelin-1 (ET-1), endothelin receptor A (ERA), endothelial nitric oxide synthase (eNOS), matrix metalloproteinase (MMP) 2, and tissue inhibitor of matrix metalloproteinase (TIMP). Results: The increase in medial wall thickness of the pulmonary arteriole in the M+I group was significantly lower than that in the M group on day 7 after infliximab treatment (P<0.05). The number of intraacinar muscular arteries in the M+I group was lower than that in the M group on days 14 and 28 (P<0.05). Expression levels of TNF-${\alpha}$, ET-1, ERA, and MMP2 were significantly lower in the M+I group than in the M group on day 5, whereas eNOS and TIMP expressions were late in the M group (day 28). Conclusion: Infliximab administration induced early changes in pathological findings and expression levels of TNF-${\alpha}$, and MMP2 in a monocrotaline-induced pulmonary hypertension rat model.

• Clinical and Experimental Pediatrics
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• v.56 no.6
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• pp.242-246
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• 2013

Purpose: The cardiopulmonary exercise test (CPET) is an important clinical tool for evaluating exercise capacity and is frequently used to evaluate chronic conditions including congenital heart disease. However, data on the normal CPET values for Korean children and adolescents are lacking. The aim of this study was to provide reference data for CPET variables in children and adolescents. Methods: From August 2006 to April 2009, 76 healthy children and adolescents underwent the CPET performed using the modified Bruce protocol. Here, we performed a medical record review to obtain data regarding patient' demographics, medical history, and clinical status. Results: The peak oxygen uptake ($VO_{2Peak}$) and metabolic equivalent ($MET_{Max}$) were higher in boys than girls. The respiratory minute volume $(V_E)/CO_2$ production ($VCO_2$) slope did not significantly differ between boys and girls. The cardiopulmonary exercise test data did not significantly differ between the boys and girls in younger age group (age, 10 to 14 years). However, in older age group (age, 15 to 19 years), the boys had higher $VO_{2Peak}$ and $MET_{Max}$ values and lower $V_E/VCO_2$ values than the girls. Conclusion: This study provides reference data for CPET variables in case of children and adolescents and will make it easier to use the CPET for clinical decision-making.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.117-123
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• 2012

The starry flounder Platichthys stellatus, like all flatfish, exhibits conspicuous lateral asymmetry in numerous traits, most obvious of which is the migration of one eye to the other side of the head during metamorphosis. Additional changes related to eye migration include asymmetrical pigmentation, and a behavioral shift from larvae that exhibit upright, open-water swimming to juveniles and adults that lie on the ocean floor, eye side up. However, the morphology of these juveniles has been quite plastic in recent years, a phenomenon which is thought to be related to a diverse suite of semi-intensive and intensive larviculture methods. The cause of morphological abnormalities in the farmed flatfish is poorly understood. In the present study, we observe the features of morphological specificity and abnormality of immature fish (mean total length 23 cm) and survey the occurrence frequency of the specificity and abnormality of juvenile (mean total length 6.70 cm) in artificial culture facility. We find 2 types of abnormality (e.g., albino in ocular side and hypermelanosis in blind side) and 1 type of specificity (e.g., lateral polymorphism). These considerably differ from normal individuals (has sinistral eye and pigmented on only one side) by several characteristics (dextral eye, ocular side albinism, blind side hypermelanosis). The incidences of albinism, hypermelanosis, and body reversal are $10.1{\pm}2.56%$, $91.7{\pm}1.7%$, and $13.1{\pm}1.1%$, respectively. These suggest that these morphometric and morphological differences occur more in artificial environment during and just after metamorphosis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.4
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• pp.363-369
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• 2014

Obesity is a worldwide problem that contributes to serious diseases, including diabetes, hypertension, and atherosclerosis. Recently, much research has examined functional natural materials and their anti-obesity activity. This study investigated the effect of enzyme-treated Ecklonia cava extracts on mice fed a high fat diet. To test the anti-obesity effects of a diet containing the enzyme-treated E. cava extracts (EEc), C57BL/6NTacSam mice were divided into six groups : normal diet (ND), high-fat diet (HFD), high-fat with Garcinia extract diet (GHD), and three high-fat with EEc diet (EHD250, EHD500, and EHD1000) groups. After 9 weeks, body weight was increased significantly in the HFD group compared to all of the EHD groups, and the weights of the liver, perirenal fat and epididymal fat paralleled the increase in body weight. The serum GOT, GPT, triglyceride, total cholesterol, and LDL-cholesterol levels were lower in the EHD1000 group than in the HFD group. The glucose and leptin concentrations were lowest in the EHD1000 group and C/EBP family expression was decreased in a dose-dependent manner. These results indicate that E. cava extracts not only have anti-oxidation functions but also anti-obesity effects.

• Journal of Nutrition and Health
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• v.33 no.6
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• pp.632-638
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• 2000

This study was designed to observe the effect of green tea on colon tumor incidence and biomarkers of colon carcinogenesis in 1, 2-dimethlhydrazine-treated rats. Male Sprague Dawley rats at 7 weeks of age were divided into two groups: control and green tea(GT) groups. Control rats had distilled water as drinking water but GT group received green tea extracts(2.5%, w/v water) as drinking water throughout the experiment periods. All rats were fed the experimental diet containing 15% fat by weight for 20 weeks. and were i.m. injected with DMH for 6 weeks to give total dose of 180mg/kg body weight. Tumor incidence was reduced in GT group (39%) compared with control group (56%) Green tea significantly reduced cell proliferation (total cells per crypt, crypt length and proliferative zone) in colonic mucosa and also significantly reduced the levels of preformed prostalandin E2(PGE2) and thromboxance B2(TXB2) in colonic mucosa but the fatty acid profile of total lipid in colonic mucosa was not significantly influenced by green tea. However the relative percent of C20:4 and the levels f preformed PGE2 and TXB2. were significantly higher in tumor tissue compared with normal surrounding mucosa.Green tea increased the fecal excretion of total bile acid but not scondary bile acid which is known as one of promoters for colon cancer,. These results suggest that green tea could have preventive effect against colon cancer when consumed daily by influencing on antioxidant effect and the metabolism of arachidonic acid.

• CELLMED
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• v.4 no.3
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• pp.20.1-20.7
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• 2014

Ethanolic leaf extract of Bauhinia variegata has been tested for its possible antioxidant potentials against sodium arsenite induced toxicity in mice. Mice were randomized into two groups of five and fifty mice. Group I consisting of 5 mice without any treatment with food and water ad libitum which served as normal control. Group II mice were fed with sodium arsenite in drinking water at 100 ppm concentration for two monthsthen they were segregated into five groups which were treated differently. Group II a mice received only arsenic as sodium arsenite with drinking water, Group II b were fed chronically 1 : 20 alcohol to distilled water (vehicle), Group II c, d, e mice were orally fed 50 mg/kg, 150 mg/kg and 250 mg/kg of B. variegata leaf extract of once daily for 15 and 30 days respectively along with arsenic. Several toxicity marker enzymes such as gamma glutamyl transferase, lactate dehydrogenase, aspartate and alanine aminotransferase, acid and alkaline phosphatase, catalase and superoxide dismutase along with haematological variables such as glucose 6-phosphate dehydrogenase, creatinine, bilirubin, haemoglobin and sugar in different groups of treated and control mice were studied. Results obtained from the in vivo experiment revealed that administration of sodium arsenite caused a significant increase in some enzymes while decrease in some. A similar trend was also observed with haematological variables. In contrast B. variegata treatment at 150 mg/kg favourably modulated these alterations and maintained the antioxidant status than other two doses i.e. 50 mg/kg and 250 mg/kg thereby making it a good candidate to be used as supportive palliating measures in arsenic induced toxicity.