• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.3
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• pp.189-196
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• 2003

In this study, the vertical opening of the non-float midwater pair trawl net was maintained by controlling the length of upper warp. This was because the head rope was able to be kept linearly and the working depth was not nearly as changed with the variation of flow speed as former experiments in this series of studies have demonstrated. We confirmed that the opening efficiency of the non-float midwater pair trawl net was able to be developed according to the increase in front weight and wing-end weight. In this study, we described the opening efficiency of the non-float midwater pair trawl net according to the variation of front weight and wing-end weight obtained by model experiment in circulation water channel. We compared the opening efficiency of the proto type with that of the non-float type. The results obtained can be summarized as follows：1. The hydrodynamic resistance was almost increased linearly in proportion to the flow speed and was increased in accordance with the increase in front weight and wing-end weight. The increasing rate of hydrodynamic resistance was displayed as an increasing tendency in accordance with the increase in flow speed. 2. The net height of the non-float type was almost decreased linearly in accordance with the increase in flow speed. As the reduced rate of the net height of the non-float type was smaller than that of the net height of the proto type against increase of flow speed, the net height of the non-float type was bigger than that of the proto type over 4.0 knot. The net width of the non-float type was about 10 m bigger than that of the proto type and the change rate of net width varied by no more than 2 m according to the variation of the front weight and wing-end weight. 3. The mouth area of the non-float type was maximized at 1.75 ton of the front weight and 1.11 ton of the wing-end weight, and was smaller than that of the proto type at 2.0∼3.0 knot, but was bigger than that of the proto type at 4.0∼5.0 knot. 4. The filtering volume was maximized at 3.0 knot in the proto type and at 4.0 knot in the non-float type. The optimal front weight was 1.40 ton.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.64-71
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• 1999

Purpose : The protective effects of dietary protein on the progression of renal failure were studied in subtotally nephrectomized rats. Methods : Treatment groups were as follows; 5/6 nephrectomy and a normal protein ($18.5\%$) diet (NP); 5/6 nephrectomy and a low protein ($6\%$) diet (LP): 5/6 nephrectomy, a normal protein diet and converting enzyme inhibitor, enalapril (NPE): 5/6 nephrectomy, a low protein diet and enalapril (LPE). Both diets were isocaloric and had the same phosphorus content. Proteinuria, remnant kidney weight, mesangial matrix expansion score and glomerular volume were assessed at 4, 12 and 16 weeks after renal ablation. Results : LP and NP developed progressive hypertension. Eight weeks after surgery, LPE and NPE controlled hypertension. LP, LPE, and NPE had significantly less proteinuria than NP at 16 weeks (P<0.05). Kidney weight in LP were markedly less enlarged than NP (P<0.05). There was no difference in kidney weight between LPE and NPE. At 12 and 16 weeks the mesangial matrix expansion score was significantly less in LP, LPE, and NPE compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume was significantly less in LP compared to NP (P<0.05). At 12 and 16 weeks mean glomerular volume in LPE was significantly less compared to NPE. Conclusion : Dietary protein restriction afforded considerable protection from renal injury in the rat remnant kidney model. During the enalapril treatment, there was no additional protective effect of dietary protein restriction against the development of renal lesions.

• Journal of Life Science
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• v.19 no.5
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• pp.652-658
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• 2009

The comparative activities of aqueous, ethanol, and methanol extracts from Aralia elata shoot (AES) and leaf (AEL) were tested by in vitro experimental models of linoleic acid peroxidation by thiocyanate and thiobarbituric acid (TBA) methods and scavenging activities of free radicals by DPPH (${\alpha}$,${\alpha}$'-diphenyl-${\beta}$-picrylhydrazyl). In addition, bio-active materials (phenolic compounds and minerals) were also measured. The extract yield of each solvent extracted from AES and AEL was 3.08% and 3.13% in aqueous, 0.58% and 0.66% in ethanol, and 0.81% and 1.73% in methanol, respectively. The highest extract yield was found in the aqueous extract from AEL. Major mineral contents (mg%) of AES and AEL were 575.7 and 759.3 in Ca, 353.5 and 330.0 in K, and 31.3 and 31.0 in Mg, respectively. The highest free radical scavenging activity was found in the aqueous extract by 28.69% at 0.1% additional level from AES and in the methanol extract by 92.36% at 0.1% additional level from AEL. Free radical scavenging activity was stronger in AEL than in AES. In antioxidative activities determined by thiocyanate and TBA methods against lipid peroxidation using linoleic acid, ethanol extracts from AEL showed the highest antioxidative activity at all treatment concentrations. These results may provide the basic data to understand the biological activities of bio-active materials derived from AES and AEL.

• The Journal of Internal Korean Medicine
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• v.33 no.4
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• pp.418-428
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• 2012

Objectives : Ojeok-san, a traditional herbal formula, has been used for the treatment of cold illness and its related symptoms such as headache, nausea and indigestion. This study was performed to compare effects of water (OJSW) and 70% ethanol extracts (OJSE) of Ojeok-san on inflammation and its related diseases atopy, asthma and obesity in vitro. Methods : We performed HPLC to investigate contents of index components of OJSW and OJSE. We investigated the effects of OJSW and OJSE with an in vitro model, using 5 cell lines, specifically RAW 264. 7, HaCaT, MC/9, BEAS-2B and 3T3-L1. Results : HPLC analysis displayed that the contents of index components were higher in OJSE than OJSW. In lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, OJSE significantly inhibited productions of interleukin (IL)-6, nitrite and prostaglandin $E_2$ ($PEG_2$). In TNF-${\alpha}$/IFN-${\gamma}$-treated HaCaT keratinocytes, OJSE significantly lowered levels of macrophage-derived chemokine (MDC) as well as regulated and normal T cell expressed and secreted (RANTES). OJSE also had a protective effect on inflammatory response by decreasing RANTES secretion in TNF-${\alpha}$-stimulated BEAS-2B cells. Conclusions : We conclude that OJSE could be more appropriate to enhance the biological activities against inflammation and its related diseases, and could be applied as a bioactive material for developing the potent anti-inflammatory agents.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.38-46
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• 2013

With increasing environmental issues from synthetic chemical herbicides, microbe-originated herbicides could be a fascinating alternative in current agriculture. We isolated Streptomyces strains that produced herbicidal active metabolite(s) against a grass weed Digitaria sanguinalis. According to the result from 16S rDNA sequence comparison with the close strains, the best isolate (Code name MS-80673) was identified as Streptomyces scopuliridis KR-001. The closest type strain was Streptomyces scopuliridis RB72 which was previously reported as a bacteriocin producer. The optimal culture condition of S. scopuliridis KR-001 was $28^{\circ}C$, pH 7.0 and culture period 4 to7 days. Both of soil and foliar application of the crude culture broth concentrate was effective on several troublesome or noxious weed species such as a Sciyos angulatus in a greenhouse and field condition. Phytotoxic symptoms of the culture broth concentrate of S. scopuliridis KR-001 by foliar application were wilting and burndown of leaves, and stems followed by discoloration and finally plant death. In crops such as rice, wheat, barley, hot pepper and tomato, growth inhibition was observed. These results suggest that the new S. scopuliridis KR-001 strain producing herbicidal metabolites may be a new bio-herbicide candidate and/or may provide a new lead molecule for a more efficient herbicide.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.1-22
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• 2017

'The worstest environment disaster', 'World's first biocide massacre', 'Home-based Sewol ferry disaster' are all phrases attached to the recent humidifier disinfectant disaster. In the spring of 2011, four of 8 pregnant women including 1 adult man passed away at a university hospital in Seoul due to breathing failure. Epidemiologic investigation conducted by the Korean CDC soon revealed the inhalation of humidifier disinfectant, which had been widely used in Korea during the winter, to be responsible for the disease. As well as lung fibrosis hardening of the lungs, other diseases including asthma, rhinitis, skin disease, liver disease, fetal disease or cancers have been researched for their relation with exposure to the products. By February 9, 2017, 5,342 cases had registered for health problems and 1,131 of them were already dead (20.8% mortality rate). Based on studies by government agencies and a telephone survey of the general population by Seoul National University and civic groups, around 20% of the general public of Korea has used these products. Since the market release of the first product by SK Chemical in 1994, over 7.1 million items from around 20 brands were sold up to 2011. Most of the products were manufactured by well-known large conglomerates such as SK, Lotte, Samsung, Shinsegye, LG, and GS, as well as some European companies including UK-based Reckitt Benckiser and TESCO, the German firm Henkel, the Danish firm KeTox, and an Irish company. Even though this disaster was unveiled in 2011 by the Korean government, the issue of the victims was neglected for over five years. In 2016, an unexpected but intensive investigation by prosecutors found that Reckitt Benckiser manipulated and concealed animal tests for its own brand and brought several university experts and company employees to court. The matter was an intense social issue in Korea from May to June with a surge in media coverage. The prosecutor's investigation and a nationwide boycott campaign organized by victims and environmental groups against Reckitt Benckiser, whose product had been used by more than 70% of victims, led to the producer's official apology and a compensation scheme. A legislative investigation organized after the April 2016 national election revealed the producers' faults and the government's responsibility, but failed to meet expectations. A special law for the victims passed the National Assembly in January 2017 and a punitive system together with a massive environmental epidemiology investigation are expected to be the only solutions for this tragedy. Sciences of medicine, toxicology and environmental health have provided decisive evidence so far, but for the remaining problems the perspectives of social sciences such as sociology and jurisprudence are highly necessary, similar to with the Minamata disease and Wonjin Rayon events. It may not be easy to follow this issue using unfamiliar terminology from medical and chemical science and the long, complicated history of the event. For these reasons the author has attempted to write this article in a question and answer format to render it easier to follow. The 17 questions are: Q1 What is humidifier disinfectant? Q2 What kind of health problems are caused by humidifier disinfectant? Q3 How many victims are there? Q4 What is the analysis of the 1,112 cases of death? Q5 What is the problem with the government's diagnostic criteria and the solution? Q6 Who made what brands? Q7 Has there been a recall? What is still on sale? Q8 Was safety not checked by any producers? Q9 What are the government's responsibilities? Q10 Is it true that these products were sold only in Korea? Q11 Why and how was it unveiled only in 2011 after 17 years of sales? Q12 What delayed the resolution of the victim issue? Q13 What is the background of the prosecutor's investigation in early 2016? Q14 Is it possible to report new victim cases without evidence of product purchase? Q15 What is happening with the victim issue? Q16 How does it compare with the cases of Minamata disease and Wonjin Rayon? Q17 Are there prevention measures and lessons?

• Journal of Life Science
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• v.18 no.7
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• pp.1005-1010
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• 2008

In this study, we investigated the inhibitory effect of four solvent fractions of Alnus firma on ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase activities. The inhibitory test showed that methanol (MeOH) extract and hexane (HX) fraction strongly inhibited pork pancreatin and salivary ${\alpha}-amylase$ activity. The MeOH extract and HX fraction of Alnus firma at the concentration of 4 mg/ml inhibited more than 70% of pancreatin and salivary ${\alpha}-amylase$ activity. The inhibitory effect of fractions has different specificities against ${\alpha}-amylase$ from pancreatin and salivary. In addition, the MeOH extract and butanol (BuOH) fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ at values of $IC_{50}$ $137.36\;{\mu}g/ml$ and $115.14\;{\mu}g/ml$ respectively. The MeOH extract and BuOH fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ than commercial agent such as 1-deoxynorjirimycin and acarbose. Inhibition kinetics of solvent fractions showed that ${\alpha}-glucosidase$ has been inhibited noncompetitively by the MeOH, EA and BuOH fraction. The aldose reductase from human muscle cell had been inhibited strongly by the MeOH extract and EA fraction at 57.996% and 83.293% at the concentration of $50\;{\mu}g/ml$, respectively. These findings may contribute to biological significance in that ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase inhibitory compounds could be used as a functional food and a drug for the symptomatic treatment of antidiabetic disease in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.133-148
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• 2014

In order to investigate community formation ability, herbaceous perennials such as Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka were planted in April 2009 at the levee slope of Gwangju Stream in South Korea. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. which grew in pots for two years and divided rhizomes of Arundinella hirta Tanaka gathered from fields were employed. Weeds growing on the experiment sites were removed twice a year until 2011 when the plant species were formed into community. Weeds were not eradicated during 2012 and 2013 to observe community sustainability of the species. T-tests on stem numbers and heights in May, July and September were conducted between 2011 and 2012, and between 2012 and 2013. Stem numbers of the five species in 2012 were significantly reduced(p<0.001) compared with those in 2011, which were attributed to weed growth in 2012. Heights of Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka in 2012 were significantly lower than those in 2011(p<0.001), which resulted from weed invasion. Heights of Miscanthus sacchariflorus Bentham in May and July 2012 were significantly decreased compared with those in 2011(p<0.001), however, heights of Miscanthus sacchariflorus Bentham in September 2012 were almost the same as those in 2011(p>0.05). Miscanthus sacchariflorus Bentham was able to compete against weeds in September 2012. Stem numbers and heights of Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. in 2013 were similar to those in 2012(p>0.05). However, stem numbers and heights of Arundinella hirta Tanaka in 2013 were significantly decreased compared with those in 2012(p<0.001). After community formation, Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. were able to maintain its community without weed removal. However, Arundinella hirta Tanaka was unable to establish its community due to the weed growth. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne are more suitable to stream levee slope environment in terms of community formation and maintenance, stream landscape enhancement and slope erosion control.

• Clinical and Experimental Pediatrics
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• v.52 no.7
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• pp.766-771
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• 2009

Purpose : The objective of this study was to compare the levels of adipocytokines in obesity group with those in control group and examine their correlation with insulin resistance. Methods : We enrolled 36 obese children (male:female [M:F]=17:19; age, $9.3{\pm}1.9yrs$) with ${\geq}95^{th}$ percentile body mass indexes (BMIs) (obesity group) and 35 healthy children (M:F=16:19; age, $9.1{\pm}2.1yrs$) with $25^{th}-75^{th}$ percentile BMIs (control group). We measured the serum leptin, adiponectin, and resistin levels and insulin resistance in both the groups. Results : The weights, heights, BMIs, fasting sugar levels, insulin levels, and homeostasis model assessment for insulin resistance (HOMA-IR) values were higher in the obesity group than in the control group. As compared to the control group, the obesity group showed significantly higher leptin levels and lower adiponectin levels; no significant difference was observed in the resistin levels. The leptin/adiponectin (L/A) ratio was higher in the obesity group than in the control group. In the obesity group, HOMA-IR showed significant positive correlations with weight, height, BMI, and leptin level. However, it was not correlated with age and adiponectin and resistin levels. In the obesity group, leptin level showed significant positive correlations with age, weight, height, and BMI, while adiponectin and resistin levels showed no such correlations with the other variables. Conclusion : We suggest that adiponectin plays an important protective role against weight gain in obese children. Further, L/A ratio can be used as a parameter for predicting the prognosis of obese children.

• Journal of Nutrition and Health
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• v.40 no.8
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• pp.736-744
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• 2007

Leptin, as an adipocyte-derived hormone, is an important regulator of food intake and energy expenditure. In the cross-sectional study, leptin was shown to be positively related to body adiposity and metabolic disorders in adults. However, there were very few studies which reported the leptin as a predictor of weight gain over time. We examined whether serum leptin can be used as an indicator of the present and 1-year past weight status in very young children. First grade students from elementary schools in Gwacheon City were enrolled in the study since 2005. The study subjects(total 375 students; 195 boys and 180 girls) participated in the investigation of both 2005 and 2006. Physical examinations including height, weight, waist circumference were done. To examine the prevalence of obesity, obesity index was used. Serum leptin was measured, and their nutritional status was also evaluated based on 3-Day dietary records. Serum leptin levels were strongly positively related with the value of the present BMI and with the value of the BMI one year before. We found no association with leptin levels and amount of energy intake and macronutrient intake in this children population. Children were divided into three groups according to leptin tertiles. The highest leptin tertile group showed highest prevalence of obesity in year 2006 as well as in year 2005. Serum leptin levels can reflect the weight status now and as well as 1-year before. Possibly serum leptin levels can predict the weight gain of year later. Without an action against the obesity on children with high leptin level, those children would maintain the excess adiposity growth and progress into the obesity-related metabolic disorders. Further studies are needed to predict the obesity as early as possible and preventive system then after.