• Journal of Welding and Joining
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• 제17권1호
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• pp.71-76
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• 1999

The real-time holographic interferometer with digital high-speed camera is applied to the experimental study of laser induced plasma/plume in pulsed Nd:YAG laser welding. A pulsed Nd:YAG laser with 1.2 kW average power is applied to generate laser induced plume. The recording speed of the high-speed camera is 3,000 f/s. The high speed photographs of weld plume without another visualization method, are compared with the visualization photographs with holographic interferometer. The radiation intensity from the laser induced plume is recorded by the high speed photographs, which fluctuated during laser radiation and disappeared after laser end. The density distribution of the plume is recorded by the holographic visualization method. The experimental results show the process of generation of the laser induced plasma/plume, and give the feasibility of quantitative measurement of laser induced plume in laser welding.

• Journal of Nutrition and Health
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• 제33권2호
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• pp.167-178
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• 2000

The effect of oral vitamin e (800IU/day) and C (500mg/day) supplementation for 10 days and/or smoking cessation for 5 days on oxidative damage to the red blood cells (RBC) of male smokers (22.2$\pm$0.2 years old) was studied. RBC were tested for their ability to protect against smoking-induced oxidative damage by measuring heme proteins (carboxyhemoglobin, hemoglobin, methemoglobin, oxyhemoglobin), hemolysis and thiobarbiturinc acid reactive substances (TBARS). Plasma levels of vitamin c, A, E, $\beta$-catotene, total cholesterol, glutamic pyruvic transaminase(GPT) and glutamic oxaloacetic transaminase(GOT) were also analyzed. In experiment one, a comparison was made of heme proteins and lipid damage to RBC, plasma antioxidant status (indexed by plasma levels of vitamin C, E, A and $\beta$-carotene) between smokers(n=56) and non-smokers (n=16). No differences were found in plasma antioxidant status, heme protein damage and TBARS concentration of RBC. In experiment two, 46 fasting male smokers from experiment one were divided into 4 groups. The groups were smoking with placebo group(SP, n=14), smoking cessation with vitamins supplementatin group (SV, n=13), smoking cessation with placebo group (NSP, n=9) and smoking cessation with vitamins supplementation group (NSV, n=10). After supplementing antioxidant vitamins, significant increases were seen in plasma vitamins supplementation group (NSV, n=10). After supplementing antioxidant vitamins, significant increases were seen plasma vitamin C (p<0.05) and vitamin E levels (p<0.05). The plasma vitamin E level was highest in the NSV group. Vitmain E and C supplementation provided some protection against heme proteins and lipid damage by lowering methemoglobin, hemolysis and TBARS concentration of RBC. Smoking cessation significantly decreased TBARS of RBC and plasma total cholesterol concentration. Supplementing vitamin E and C with smoking cessation considerably lowered plasma total cholesterol. These results point to a special association among smoking, oxidative damage and plasma antioxidant vitamin status. They indicate that increases in plasma antioxidant status can be detected after the supplementation of vitamin C and E and that smoking cessation had an additional effect on plasma vitamin E level. The present data suggest that improved antioxidant status induced by antioxidant supplementation or smoking cessation may help prevent oxidative damage in smokers.

• Nutritional Sciences
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• 제6권2호
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• pp.85-93
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• 2003

The purpose of this study was to investigate the effects of a butanol fraction of fraction of Alisma canaliculatum All. Braun et Bouche (Ac), and of selenium (Se), on plasma gllucose and lipid levee in streptozotocin (STD-induced diabetic rats. Male Sprague-Dawley rats, fed the AIN-93 recommended diet, were divided into five groups: a non-diabetic control group (no STZ treatment), and four 572-induced diabetic groups which consisted of a diabetic-control group, an Ac-treated group, an Ac-Se treated group, and a Se-treated group. Diabetes was induced in the rats by an injection of STZ into the tail vein at a dose of 45 mg/kg body weight. The butanol (BuOH) fraction of Ac was orally administered at a rate of 400 mg/kg body weight for 21 days to both the Ac and Ac-Se groups. The supplementation of selenium in the Se and Ac-Se groups was achieved by adding (freshly, every day) 2 mg of Se as Na$_2$SeO$_3$ per kg of feed. The rats'body weights and hematocrit (Hct) levels were measured, along with plasma levels of glucose, insulin, cholesterol, HDL-cholesterol, triglyceride (TG), and free fatty acids (FFA). Aminotransferase activities were also analyzed. The non-diabetic rats gained weight, while the diabetic rats lost weight - except in the Ac-Se group, which maintained their initial weight. The blood glucose levels of the Ac group and the Se group were significantly lower than for the diabetic-control group. The plasma triglyceride levels were lowered when both Ac and Se were administered to diabetic rats. The concentrations of plasma FFA in the Ac-Se group were significantly lower compared with the diabetic-control group. Plasma cholesterol levels and alanine aminotransferase activity in the Ac, Ac-Se, and Se groups were significantly lower when compared with the diabetic-control group. Aspartate aminotransferase activity was significantly lower in the Se group compared to the other diabetic groups. These data show that treatment with a butanol fraction of Ac in combination with Se has no synergistic effect. Plasma glucose levels tended to be low when Se was administered to diabetic rats. Supplementation of Se in diabetic rats did not elicit a significant increase in plasma insulin levels or result in hypolipemic effects.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.366-370
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• 2002

The objective of this study was to examine whether feeding induced hypovolemia (decrease in plasma volume) acts on the regulation of feed intake in goats fed on dry forage. In order to prevent feeding induced hypovolemia, a 2 h intravenous infusion (16-18 ml/min) of isotonic mannitol solution was begun 1 h prior to feeding and continued until 1 h after the start of the 2 h feeding period. The intravenous infusion of isotonic mannitol solution (MI) decreased plasma osmolality by 1.0%, plasma total protein concentration by 4.2% and hematocrit by 5.9%, respectively. In comparison with no infusion (NI), MI significantly decreased thirst level by approximately 13%. At the completion of the 2 h feeding period, cumulative feed intake had been increased by 43% by MI. In conclusion, feeding induced hypovolemia in goats fed on dry forage increased thirst level more than the increase in plasma osmolality did. The results demonstrate that feeding induced hypovolemia is one of the factors controlling feed intake in goats fed on dry forage.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.333-337
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• 2001

The pharmacokinetic changes of diltiazem (DTZ) and its main metabolite, deacetyldiltiazem (DAD) were studied after oral administration of DTZ to normal rabbits and mild and medium folate-induced renal failure rabbits. DTZ 10 mg/kg was given to the rabbits either orally (n=6). Plasma concentrations of DTZ and DAD were determined by a high performance liquid chromatography assay. The area under the plasma concentration-time curves (AUC) and maximum plasma concentration ($C_{max}$) of DTZ were significantly increased in mild and medium folate-induced renal failure rabbits. The metabolite ratio of the DTZ to DAD were significantly decreased in mild and medium folate-induced renal failure rabbits. The volume of distribution ($V_{d}$) and total body clearance ($CL_{t}$) of DTZ were significantly decreased in mild and medium folate-induced renal failure rabbits. The elimination rate constant ($\beta$) of DTZ was significantly decreased in folate-induced renal failure rabbits, but that of DAD was significantly increased. These findings suggest that the hepatic metabolism of DTZ was inhibited and the $V_{d}$, $CL_{t}$ and $\beta$ of DTZ were significantly decreased in mild and medium folate-induced renal failure rabbits.

• 한국연소학회지
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• 제10권4호
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• pp.24-32
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• 2005

Various types of plasma source applied in $CH_4$ decomposition process are compared. DBD by pulse and AC power, spark by pulse and AC power, rotating arc and hollow cathode plasma are chosen to be compared. The results show that $CH_4$ conversion per given unit power is relatively high in hollow cathode plasma and rotating arc that induces rather high temperature condition and that is why both thermal dehydration and plasma induced decomposition contribute for the overall process. In case of DBD wherein high temperature electron and low temperature gas molecule coexist, the process shows low conversion rate, for in rather low temperature condition the contribution of thermal dehydration is lowered. Selectivity of $C_2H_6$ and $C_2H_2$ is shown to be a good parameter of the relative contribution of plasma chemistry in the overall process. From the results we concluded that required condition of plasma source for a cost effective and high yield $CH_4$ decomposition is to have characteristics of both thermal plasma and non thermal plasma in which temperature is high above a certain threshold state for thermal dehydration and electron induced collision is maximized in the same breath.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.138-138
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• 2002

Oxidative stress has been associated with a number of diseases in human. Among the sources that can generate oxidative stress, it has been reported that iron can generate reactive oxygen species (ROS)with thiol. In iron overload state, increased thiol levels in plasma appeared to be associated with human mortality. In this study we examined whether iron could interact with thiols in plasma, generating ROS. In human plasma, unlike with Fe(III), Fe(II) increased lucigenin-enhanced chemiluminescence in concentration-dependent manner, and this was inhibited by SOD. Boiling of plasma did not affect chemiluminescence induced by Fe(II). Hovever, thiol depletion in plasma by pretreatment with N-ethylmaleimide (NEM)decreased Fe(II)-induced chemiluminescence significantly, suggesting that Fe(II) generated superoxide anion by the nonenzymatic reaction with plasma thiol. Consistent with this findings, albumin, the major thiol contributor in plasma, also generated ROS with Fe(II) and this generation was inhibited by pretreatment with NEM. Treatment with Fe(II) to plasma resulted un significant reduction of oxygen radical absorbance capacity (ORAC) value, suggest that total antioxidant capacity could diminished in iron overload state. In conclusion, In iron overload state, plasma may be affected by oxidative stress mediated by nonenzymatic reaction of Fe (II)with plasma thiol.

• Molecules and Cells
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• 제19권1호
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• pp.74-80
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• 2005

Stress is known to inhibit granule cell proliferation in the hippocampus. However, recent studies suggest that the commonly used dose of bromodeoxyuridine (BrdU) is insufficient to label all fractions of granule cells. Furthermore, stress-induced changes in BrdU availability may influence the labeling of newly born cells. To investigate whether changes in BrdU availability affect measurements of stress-induced granule cell proliferation, granule cell proliferation was assessed using injection of high doses of BrdU before and after restraint stress lasting 1 h. In addition, to determine whether stress-induced changes in plasma corticosterone levels were influenced by the BrdU, time-dependent changes in plasma corticosterone levels over 2 h after BrdU injection were compared with total accumulated plasma corticosterone levels [as determined by areas under the curve (AUC)]. Restraint stress significantly reduced the numbers of BrdU-labeled cells and clusters in the granule cell layer (GCL) of rats that received BrdU after stress, and decreases of similar magnitude were observed when the rats were given BrdU before stress. BrdU injection enhanced the stress-induced plasma corticosterone response, but there was no difference between the mean AUCs of plasma corticosterone levels of animals injected with BrdU before or after stress. These observations suggest that restraint stress decreases granule cell proliferation, and that this may be influenced by the extent and duration of plasma corticosterone increases rather than by changes in the availability of BrdU.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.518-521
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• 2004

The degradation characteristics of MgO protective layer and phosphors have been investigated in terms of the ion-induced secondary electron emission coefficient ${\gamma}$ and static margin of discharge voltages, respectively, in this experiment. The ion-induced secondary electron emission coefficients ${\gamma}$ for the degraded MgO protective layer and phosphors have been studied by ${\gamma}$ -focused ion beam system. The energy of Ne+ ions used is from 80 eV to 200 eV in this experiment. The degraded MgO and phosphor layers are found to have higher ${\gamma}$ than that of normal ones without degradations or aged one. Also, the static margin of discharge voltages for test panels with degraded MgO protective layer and phosphors been found to be seriously decreased in comparison with those of normal ones without degradations.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.188-192
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• 2004

The main aim of this study was to investigate the sterilization effects of microwave-induced argon plasma at atmospheric pressure on paper materials contaminated with fungi. Plasma-treated filter papers showed no evidence to an unaided eye of burning or paper discoloration due to the plasma treatment. All fungi were perfectly sterilized in less than 1 sec, regardless of strains. These results indicate that this sterilization method for paper materials is easy to use, requires significantly less time than other traditional methods and different plasma sterilization methods, and is also nontoxic.