• New & Renewable Energy
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• v.19 no.4
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• pp.11-19
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• 2023

Levulinic acid (LA) derived from cellulosic biomass, serves a crucial intermediate that can be used in various chemical conversions. This study focused on optimizing the production of LA using two types of pretreated rice husk (de-ashed and delignificated cellulosic biomass) in a batch reaction system through catalytic conversion with sulfuric acid. To determine the optimal conditions, the conversions of glucose and α-cellulose were examined to compare the effects of pretreatment on the rice husk. The experimental parameters covered a broad spectrum, including temperatures ranging from 140℃ to 200℃, a reaction time was up to 600 minutes, and a substrate to catalyst (acid solution) ratio of 100 g/L. The highest LA yield was 44.8%, achieved from de-ashed rice husk with 3.0 wt.% of sulfuric acid at 180℃ and with a reaction time of 180 minutes. In the case of the delignificated rice husk, a LA yield of 43.6% was obtained with 3.0 wt.% of sulfuric acid at 200℃ and with reaction time of 30 minutes.

• Korean journal of food and cookery science
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• v.12 no.4
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• pp.535-540
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• 1996

Potato slices were dipped in solution of 2% CaCl$_2$, and 1% chitosan or preheated in each of these solutions for refrigeration for 4 weeks at 5$^{\circ}C$. Changes in L value, content of total phenol and chlorogenic acid and po lyphenol oxidase activity were determined. During refrigeration, it was found that L values of potato slices treated with CaCl$_2$, (CaPS) and those treated with chitosan (ChPS) increased. Contents of total phenol and chlorogenic acid of potato slices decreased, While potato slices preheated in CaCl, solution (Hcaps) showed much decreases. And polyphenol oxidase (PPO) activity of potato slices decreased except CaPS and decreases in PPO activities were much larger in preheated potato slices. From these results, of those treatments used, chitosan treatment combined with preheating have shown to be effective to control enzymatic browning of potato slices during refrigeration.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1315-1323
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• 1998

Effect of oral taurine supplementation on plasma total and phospholidpid -fatty acid profiles and their metabolism were evaluated in healthy female adults. Among twenty five female volunteers(23.6$\pm$0.3 years old ) participated in the taruine supplementation program(6g taurine /day), twenty four subjects succesfully completed the 2 week program , and only nine subjects continued to take taurine for another 2 weeks. Levels of plasma fatty acids and taruine were measured by gas-liquid chromatobraphy and an automated amino acid analyzer based on ion exchange chromatography, respectively. Plasma taurine concentration s of the subjects were 108. 7$\pm$3.4 , 184.2$\pm$8.2 and 235.9$\pm$77.0$\mu$emol/L at 0 , 2 and 4 weeks of taurine supplementation. Fatty acid compositions and elongation and desaturation indices of polyunsaturated fatty acids (PUFA) in plasma total lipids were not influenced by oral taurine supplementation. However, fatty acid compositions and their metabolism in plasma phospholipids were significantly affected by taurine supplementation in female adults. Compared to the values for 0 week, the percentage of saturated fatty acids (SFA) in plasma phospholipid was significantly lowered at 2 weeks, but elevated at 4 weeks of taurine supplementation. In contrast , the percentage of phospholipid PUFA significantly increased at 2 weeks and decreased at 4 weeks of taurine supplementation from to the values for 0 weeks. Foru weeks of oral taurine supplementation signifinatly elevated the eongation index(20 : 4$\omega$6 ⇒22 : 4 $\omega$6, p<0.01), and decreased the desaturation index (20 : 3 $\omega$6 ⇒20 : 4 $\omega$6 , p<0.01) of $\omega$6 fatty acids in plasma phospholipids. Plasma taurine concentration was positively correlated with the percentage of 14 : 0 fatty acids and the enlongation index o f$\omega$3 fatty acids(20 : 5 $\omega$3 ⇒22 : 5 $\omega$3), and thenegatively correlated with the percentage of 20 : 0 in plasma phospholipids. These results indicate that oral taurine supplementation for 4 weeks signidicantly elelvated the percentage of SFA, and lowered the percentage of PUFA in plasma phospholipids with no influence on plasm total fatty aicd composition in healthy female adults.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.736-742
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• 1994

This study was designed to observe the effects of the mixed diets of edible mushrooms and vegetables oils on the lipid component and fatty acid composition in liver of the diet induced hydpercholesterolemic rats. Ten groups of male S.D. rats were fed a basal diet supplemented with 5% of one of three mushrooms(G.I, L.e, A.j) and 10% of one of three vegetable oils (olive ,safflower perilla) for three weeks. In liver, total cholesterol concentration was significantly low in group 3 (olive oil 10 % + L. edodes 5%) and 6 (safflower oil 10 % $_2$L. edodes 5%) , triglyceride concentration was low in groups 8 (perilla oil 10 % + g. lucidum 5%) and 9 (perilla oil 10% + L. edodes 5%) and phospholipid concentration was significantly low in groups 3, 5, (safflower oil 10 % + G.lucidum 5%), 6, 7 (safflower oil 10 % + A .judae 5%) 8, 9 and 10 (perilla oil 10% + a. judae 5%). in the fatty acid composition of total lipid inliver, monounsaturated fatty acid (MUFA) concentration s were high in groups 2 (olive oil 105 + g. lucidum 5%), 3, and 4 (olive oil 10% + A. judae 5%) and all the perilla oil groups, polyunsaturated fatty acid (PUFA) and linoleic aicd concentrations were signifciantly high in all the safflower oil groups. In the fatty acid composition of liver phospholipid , PUFA concentrations were ghih but MUFA concentrations were low. In the triglyceride component, MUFA were some more than saturated fatty acid (SFA) . In the cholesteryl ester component, MUFa concentrations were significantly high. In the fatty acid composition of liver lipid components, linholeic acid was high in the PUFA and so it was major fatty acid. Eicosapentaenoic acid (EPA) of phospholipid component in liver was significantly high.

• Korean journal of food and cookery science
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• v.13 no.2
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• pp.87-91
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• 1997

Egg yolk oil was obtained by roasting and Pressing egg yolks of hen's egg breeding on the open bin system and the cage system, respectively. Lipids in egg yolk oil were extracted with a mixture of chloroform and methanol (2 : 1, V/V), and fractionated into neutral lipid, glycolipid, and phospholipid by silicic aicd column chromatography. Fatty acid composition of each fraction was determined by gas chromatography. The major fatty acids of total lipids and neutral lipids are in sequence of oleic acid, palmitic acid, and linoleic acid. The major fatty acids of the glycolipids are palmitic acid, oleic acid, stearic acid, and lauric acid successively. The major fatty acids of phospholipids are oleic acid, lauric acid, and Palmitic acid consecutively. About the fatty acids composition of egg yolk oil in the open barn system, the contents of saturated fatty acid are lower and the contents of unsaturated fatty acid are higher than that of the case system. The contents of unsaturated fatty acid in egg yolk oil is higher than that of saturated fatty acid in total lipids and nutral lipids. Unsaturated fatty acid/saturated fatty acid of e99 yolk oil in the open barn system is higher than that of the cage system in glycolipids and phospholipids.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.266-274
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• 2001

The chemical properties and physiological activities of the freeze-dried stromata of Cordyceps militaris were examined. A proximate analysis exhibited that the stromata consisted mainly of crude carbohydrate (74.3%), crude protein (11.5%), and moisture content (8.7%), with a low content of crude ash (4.%) and fat (1.3%). The carbohydrate was mostly composed of glucose (88.6%). A large quantity of essential fatty acids, including linolenic acid (33.8%) was also observed. An analysis of the component amino acid showed a relatively high ratio of the essential amino acids, lysine (101.2 mg/g), methionine (62.7 mg/g), and acidic amino acids of glutamic aicd (57.5 mg/g) and aspartic acid (43.9 mg/g), whereas a low of tyrosine content (4.7 mg/g). An examination of the cordycepin content indicated tht the stromata and mycelium-embedded media (silkworm pupae) contained 0.2% and 0.5%, respectively. From the examination of the physiological activities, based on methanol extract (M), ethylacetate extract (EA), and hot-water extract (HW) fractions of the stromata, the hot-water extract (HW) fraction showed the most potent intestinal immune modulating activity, anticoagulant activity, and anticomplementary activity, whereas the ethylacetate extract (EA) fraction exhihited a radical scavenging activity. Therefore, the results from the present study indicate that the stromata of C. militaris contain various healthy chemical ingredients, and that especially boiled water extract of whole body would apprear to provide beneficial physiological activities.

• The Korean Journal of Pharmacology
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• v.9 no.2
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• pp.17-27
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• 1973

Modifying the technique described by Schmidt, et al. (1972) the duodenum and stomach of female rats were perfused separately and contiunously with saline solution under urethane anesthesia. Secretory response of caerulein (Prof. V. Erspamer, F.I. 6934 Caerulein, Farmitalia, Italia), a gastrin or CCK-PZ like peptide, on acid, pepsin, bicarbonate and amylase were studied with and without simultaneous administration of secretin, CCK-PZ or other agents known secretory suppressives. A significant increase of acid, pepsin and amylase output was induced by intravenous infusion of caerulein. The response of acid secretion by caerulein in doses of 140 ng/100g/hr was equivalent to the response of histamine in the doses of $280\;{\mu}g/100g/hr$ and on a weight basis the potency of caerulein was approximately 2,000 times greater than histamine in rats. Acid secretory response of caerulein in the doses of 140 ng/100 g/hr was inhibited by simultaneous infusion of secretin in the doses of 0.2 u/ 100 g/hr, and the acid response was partly inhibited by concomitant infusion of histamine in the doses of $280\;{\mu}g/100g/hr$, but the response was enhanced by infusion of CCK-PZ in the doses of 0.2 u/100 g/hr. The secretory response of both aicd and enzymes were inhibited following administration of atropine in doses of 0.2 mg/100 g, but the response were not affected by hexamethonium in doses of 0.5 mg/100 g. In summary, it is concluded that caerolein is every effective in an increase of acid, pepsin and amylase secretion in rats through, possibly in part, the muscarinic and/or histaminic mechanism(s).

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.165-174
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• 1995

The purpose of this study was to evaluated the improve method of demineralization and damage on the enamel stufece related to bonded orthodontic bracket. Enamel surface of the 40 Intact premolars were treated by aicd etching and various fluoride application methods and then maintained in the patient mouth of 3 months. After extraction of all the sampled premolars, enamel surfaces were evaluated by Scanning electron microscope. The obtained results were as follow. 1. Enamel surface relate to bonded orthodontic bracket showed demineralization and damage, slightly. 2. Group 6 treated by $2\%$ NaF iontophoresis presented and almost similarity to nomral enamel surface. 3. Group 2 treated by acid etching had demineralization and damage on the enamel surface much more than other groups treated by various fluoride application methods. 4. Demineralization and damage on the enamel surface caused by bonded orthodontic bracket is improved by various fluoride application methods.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.2
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• pp.103-108
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• 1998

A hydrophobic substrate triolein was hydrolyzed by lipase in a mono-phase reaction system containing cyclodextrin(CD) as emulsifier. The triolein was transformation to an emulsion-like state in the CD containing reaction system in contrast to the oil-droplet like state without CD due to the formation of an inclusion complex between the lipids and CDs. The hydyrolysis reaction increased substantially in the CD containing reaction system, and the optimum reaction conditions including the amount of lipase, ${\beta}$-CD concentration, and mixing ratio of triolein and ${\beta}$-CD, were determined. The performance of the enzyme reaction in a mono-phase reaction system was compared with that of a two-phase reaction system which used water immiscible hexane as the organic solvent. The role of a CD in the mono-phase reaction system was elucidated by comparing the degree of the inclusion complex formation with triolein and oleic acid, Km and Vmax values, and product inhibition by oleic aicd in aqueous and CD containing reaction systems. The resulting enhanced reaction seems to be caused by two phenomena; the increased accessibility of lipase to triolein and reduced product inhibition by oleic acid through the formation of an inclusion complex.

• Journal of Korean Society of Archives and Records Management
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• v.1 no.1
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• pp.177-200
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• 2001

The causes which affects the deterioation of paper arc paper structure, papermaking process, temperature and rative humidity, light and biological agents. Paper made from cllulose fibers by the wood and the nonwood, This paper structure is further hydrolyzed by acidic additive such as the sizing agents during the manufacturing process. These additives leave residual acids in the paper, which break the cellulose clown to simper molecules. The results is weak paper and bas caused most of the damage to book. This study was carried out to investigate the presevation and the deacidification for the permanenece by the book. The deacidification and the chemical agents aims to nutralized the aicd in paper and add alkaline to it as a buffer to withstand future acid attacks. By applying the system to the acid paper with a pH of 4.5 neutralized a pH of 8.5. The expected of alkaline reserved paper extend about 2times and 3times than acidic paper.