• 대한안전경영과학회지
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• 제8권6호
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• pp.29-39
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• 2006

The effect of parameters on the consequence of the flash fire accident by the release of heavy gas(in this study, xylene vapor) was analyzed. Simulation results showed that the distance with the lower flammable limit($X_{LFL}$) was increased with the increase of the release hole diameter. For the case of the elevated release, $X_{LFL}$ was increased with the increase of the wind speed and the release height, but $X_{LFL}$ was not affected by the wind speed for the release on the ground level. Therefore, the accident in the elevated release was more dangerous than the release on the ground level. In this condition, the release height had more effect on $X_{LFL}$ at the night time than the daytime and in the urban area than the rural area.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.207-213
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• 1989

This study was performed to investigate the mechanism of in vitro cytotosic actions of polyacetylenes which are panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C. A. Meyer. DNA synthesis of L1210 cells was significantly inhibited with dose dependent pattern when L1210 cells were treated for 1 hour with over 5 .mu.g/ml of polyacetylenes. Panaxydol which had the most potent cytotoxicity among three polyacetylenes showed also the strongest inhibitory effect on DNA synthesis. Intracellular cyclic AMP levels of L1210 cells treated with 2.5 $\mu$g/ml of panaxydol or panaxytriol were significantly elevated on the incubation duration. The elevation of cyclic AMP levels by panaxytriol was higher than that by panaxydol, but no significant increase in cyclic AMP by panaxynol was observed. All three polyacetylenes had no effect on glycolysis of L1210 cells. Electron microscopic observations revealed that polyacetylenes caused damage to plasma membranes of L1210 cells in proportion to their cytotoxicities at each $ED_{50}$ value (panaxydol > panaxynol> panaxytriol). These results suggest that cytotoxicities of polyacetylenes against L1210 cells might be mediated by elevated cyclic AMP level, even though the relationship among their cytotoxicities, inhibitory effect on DNA synthesis and ability to elevation of cyclic AMP level are not fully agreed, and might be also related to membrane damage.

• Journal of Pharmaceutical Investigation
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• 제16권3호
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• pp.110-117
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• 1986

Plasma disappearance of amaranth (AM), a model compound of organic anionic drugs, was retarded by intravenous infusion of taurodeoxycholate (TDC), a representative bile acid, in the rat. Biliary excretion accounted for 30-60% of the systemic excretion of AM. AM seemed to be metabolised in the hepatocyte to form a compound that is excreted more rapidly into the bile than AM itself, considering apparent biliary clearance, $CL_{bil}$, is much larger than systemic clearance, $CL_s$. Decrease in $CL_{bil}$ by TDC infusion might be due to elevated plasma level rather than decreased biliary excretion of AM. Decreased distribution or urinary excretion of AM by TDC was supposed to be one of the probable reasons of elevated plasma level. Competitive inhibition between AM and TDC on tissue distribution and urinary excretion might explain the mechanism. The effect of TDC on the $CL_{bil}$ of methylene blue, a cationic dye, was quite different from that of AM, as reported previously by us. More intensive study would be necessary to elucidate the difference of biliary excretion between organic anions and cations.

• Applied Science and Convergence Technology
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• 제27권5호
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• pp.100-104
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• 2018

Herein, we present the behavior of plasma-doped graphene upon high-temperature vacuum annealing. An ammonia plasma-treated graphene sample underwent vacuum annealing for 1 h at temperatures ranging from 100 to $500^{\circ}C$. According to Raman analysis, the structural healing of the plasma-treated sample is more pronounced at elevated annealing temperatures. The crystallite size of the plasma-treated sample increases from 13.87 to 29.15 nm after vacuum annealing. In addition, the doping level by plasma treatment reaches $2.2{\times}10^{12}cm^{-2}$ and maintains a value of $1.6{\times}10^{12}cm^{-2}$, even after annealing at $500^{\circ}C$, indicating high doping stability. A relatively large decrease in the pyrrolic bonding components is observed by X-ray photoelectron spectroscopy as compared to other configurations, such as pyridinic and amino bindings, after the annealing. This study indicates that high-vacuum annealing at elevated temperatures provides a method for the structural reorganization of plasma-treated graphene without a subsequent decrease in doping level.

• 한국조리학회지
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• 제13권3호
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• pp.199-206
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• 2007

Hypoglycemic efficacy of natural functional mixture(FM) and level of the diabete related hormones in streptozotocin(STZ)-induced diabetic rats were investigated. Male Sprague-Dawley rats were divided into three groups (normal, diabetic fed diets with/without FM). Supplement of FM did not affect the body weight and feed intake of STZ-induced diabetic rats. The increase in the weight of liver of STZ-induced diabetic rats was weakened by supplement of FM, whereas the weight of kidney and heart was not affected. Blood glucose level was slightly, and glucose tolerance of post-feeding was significantly improved by functional mixture. The mixture significantly reduced the elevated HbA1C level of diabetic rats by 15%, and it increased the level of insulin and C-peptide in blood and decreased glucagon level. Therefore, we conclude that FM in this study has a potency of prevention and treatment of diabetes mellitus.

• Journal of Preventive Medicine and Public Health
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• 제46권5호
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• pp.213-225
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• 2013

Objectives: The aim of this study was to evaluate the association between Agent Orange exposure and self-reported diseases in Korean Vietnam veterans. Methods: A postal survey of 114 562 Vietnam veterans was conducted. The perceived exposure to Agent Orange was assessed by a 6-item questionnaire. Two proximity-based Agent Orange exposure indices were constructed using division/brigade-level and battalion/ company-level unit information. Adjusted odds ratios (ORs) for age and other confounders were calculated using a logistic regression model. Results: The prevalence of all self-reported diseases showed monotonically increasing trends as the levels of perceived self-reported exposure increased. The ORs for colon cancer (OR, 1.13), leukemia (OR, 1.56), hypertension (OR, 1.03), peripheral vasculopathy (OR, 1.07), enterocolitis (OR, 1.07), peripheral neuropathy (OR, 1.07), multiple nerve palsy (OR, 1.14), multiple sclerosis (OR, 1.24), skin diseases (OR, 1.05), psychotic diseases (OR, 1.07) and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the division/brigade-level proximity-based exposure analysis, compared to the low exposure group. The ORs for cerebral infarction (OR, 1.08), chronic bronchitis (OR, 1.05), multiple nerve palsy (OR, 1.07), multiple sclerosis (OR, 1.16), skin diseases (OR, 1.05), and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the battalion/company-level analysis. Conclusions: Korean Vietnam veterans with high exposure to Agent Orange experienced a higher prevalence of several self-reported chronic diseases compared to those with low exposure by proximity-based exposure assessment. The strong positive associations between perceived self-reported exposure and all self-reported diseases should be evaluated with discretion because the likelihood of reporting diseases was directly related to the perceived intensity of Agent Orange exposure.

• Nutritional Sciences
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• 제7권4호
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• pp.196-200
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• 2004

There are increasing evidences that prebiotics can modulate various properties of the immune system. This study was conducted to investigate effects of three kinds of fructans (chicory inulin, chicory inulin oligosaccharide and fructooligosaccharide) and a glucose oligomer(isomaltooligosaccharide) in large bowel mass and innnunoglobulin A (IgA) in rats. Forty five Sprague-Dawley male rats weighing about 1909 were randomly sorted to receive one of the five treatments, which were control diet, control diet+6% isomaltooligosaccharide (IMOS), control diet+6% fructooligosaccharide (FOS), control diet+6% chicory inulin oligosaccharide (CIOS), or control diet + 6% chicory inulin (CI). Rats were pair-fed and received the experimental diets for 5 weeks. Cecal and colonic wall weights were significantly higher in fructan (FOS, CIOS, CI)-fed groups compared with control and IMOS groups, and the length of colon was elevated in FOS and CIOS groups compared with control group. Fecal concentrations of acetic acid and total short-chain fatty acids (SCFAs) were significantly elevated in fructan-fed groups. Plasma and cecal levels and fecal excretion of immunogiobulin A (IgA) in rats were not significantly different among groups. However, fructooligosaccharide tended to increase IgA level in cecum. Cecal IgA level was significantly negatively correlated with pH of cecal content (r=-0.337), positively correlated with acetic acid level (r=0.310). Fecal IgA excretion was positively correlated with total SCFA (r=0.311) and propionic acid (r=0.400) level in feces. These results indicate that fructooligosaccharide and chicory inulin oligosaccharide exerted trophic effects in large bowel wall, increased production of SCFAs and decreased pH, which were conditions positively associated with cecal and colonic IgA secretion.

• Restorative Dentistry and Endodontics
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• 제38권3호
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• pp.141-145
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• 2013

Objectives: Assessment of dental pain severity is very challenging in dentistry. Previous studies have suggested that elevated salivary alpha amylase may contribute to increased physical stresses. There is a close association between salivary alpha amylase and plasma norepinephrine under stressful physical conditions. The aim of this study was to evaluate the relationship between pain severity and salivary alpha amylase levels in patients with symptomatic irreversible pulpitis. Materials and Methods: Thirty-six patients (20 females and 16 males) with severe tooth pain due to symptomatic irreversible pulpitis were selected. The visual analogue scale (VAS) score was used to assess the pain severity in each patient. Unstimulated whole saliva was collected, and the level of alpha amylase activity was assessed by the spectrophotometric method. Statistical analysis was performed using SPSS 13. Results: The level of alpha amylase was significantly increased in the saliva in association with pain severity assessed by VAS. The salivary alpha amylase was also elevated with increased age and in males. Conclusions: There was a significant correlation between the VAS pain scale and salivary alpha amylase level, which indicates this biomarker may be a good index for the objective assessment of pain intensity.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.31-40
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• 1999

Many factors may affect periodontal changes during the physiologic conditions of woman(e.g. puberty, menstrual cycle, pregnancy, menopause). Recently many research has focused on the immunological changes of host, but the exact mechanism is not clear. Collagen is a major constituent of periodontium, and collagenase specifically digests the collagen and plays a role in destruction of periodontal tissue. So, I suppose that it participates with the cytokines in the inflammation of gingiva and vascular response during the changes of female sex hormones. Because there are some evidences of the existence of the receptors of estrogen and progesterone in the gingiva, it may be a target tissue of female sex hormones. In this experiment, gingival fibroblast and periodontal ligament cell were cultured in the presence of various concentrations of estrogen or progesterone corresponding to the menstrual cycle and pregnancy. Collagenase activity of the supernatant of culture media was determined by Spectrophotometric collagenase assay. The enzyme activity was calculated by the % decrease of the coated collagen. 1. The estrogen at both concentrations had no effect on the activity of collagenase of the gingival fibroblast. 2. The progesterone had some effect on the collagenase activity of the gingival fibroblast at low and high concentration of menstrual cycle, and elevated the enzyme activity at all range of pregnancy concentrations. 3. In periodontal ligament cells, estrogen elevated the enzyme activity at the early pregnancy concentration and progesterone elevated at the concentration just before menstruation. In this experiment, pregesterone elevated the collagenase activity of gingival fibroblast and periodontal ligament cells. But the mechanism of the up-regulation of the enzyme activity was not confirmed. The more experiments of direct effect of progesterone on gingival at the molecular level(e.g. northern blot analysis) can reveal the exact mechanism.

• 동의신경정신과학회지
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• 제14권2호
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• pp.61-78
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• 2003

Objective : This study was designed to assess the protective effects of Chengwhabosimtang on the animal model of depression, chronic mild stress(CMS). Method : Male Sprague-Dawley rats were used for this experiment. The subjects were divided into 3 groups ( 1. CMS-drug: Chengwhabosimtang administered during CMS treatment, 2. CMS-vehicle: water administered, 3. normal ). After 4 weeks of CMS treatment, they were executed Forced swimming test(FST) and Elevated plus maze. Tyrosine hydroxylase(TH) in ventral tegmental area(VTA) and c-Fos in paraventricular nucleus(PVN) were measured. Result : 1. In FST, CMS-drug group showed significantly decreased immobility behavior. 2. CMS-drug group showed no significantly lower TH level in VTA than CMS-vehicle group. 3. CMS-drug group showed significantly less c-Fos expressed cell bodies in PVN than CMS-vehicle group. 4. In Elevated plus maze, CMS-drug group showed no significantly anxiety. Conclusion : These results suggest that Chengwhabosimtang may have protective antidepressant effects in CMS model rats. And these effects could be explained by the elevated stress-copying behaviors which are related with PVN of hypothalamus and dopaminergic neurons in VTA.