• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.167-174
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• 2013

Purpose: This study was conducted to evaluate the roughness and surface alternations of three differently blasted titanium discs treated by $Nd:YVO_4$ Laser irradiation in different conditions. Materials and methods: Thirty commercially pure titanium discs were prepared and divided into three groups. Each group was consisted of 10 samples and blasted by $ZrO_2$ (zirconium dioxide), $Al_2O_3$ (aluminum oxide), and RBM (resorbable blasted media). All the samples were degreased by ultrasonic cleaner afterward. Nine different conditions were established by changing scanning speed (100, 300, 500 mm/s) and repetition rate (5, 15, 35 kHz) of $Nd:YVO_4$ Laser (Laser Pro D-20, Laserval $Korea^{(R)}$, Seoul, South Korea). After laser irradiation, a scanning electron microscope, X-ray diffraction analysis, energy dispersive X-ray spectroscopic analysis, and surface roughness analysis were used to assess the roughness and surface alternations of the samples. Results: According to a scanning electron microscope (SEM), titanium discs treated with laser irradiation showed characteristic patterns in contrast to the control which showed irregular patterns. According to the X-ray diffraction analysis, only $Al_2O_3$ group showed its own peak. The oxidation tendency and surface roughness of titanium were similar to the control in the energy dispersive X-ray spectroscopic analysis. The surface roughness was inversely proportional to the scanning speed, whereas proportional to the repetition rate of $Nd:YVO_4$. Conclusion: The surface microstructures and roughness of the test discs were modified by the radiation of $Nd:YVO_4$ laser. Therefore, laser irradiation could be considered one of the methods to modify implant surfaces for the enhancement of osseointegration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1139-1147
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• 2013

The purpose of this study was to analyze the relationship between sanitary knowledge score and sanitary management performance among school foodservice employees. For this purpose, a paper-based questionnaire was developed and distributed to 300 school foodservice employees in Jinhae-gu, Changwon from May 13 to June 10 in 2009. A total of 276 responses were received and analyzed. The results of this study were as follows. The sanitary knowledge score of school foodservice employees was 16.60 (total score: 20). Their sanitary management performance level was 4.77 (based on a 5-point Likert scale). We found that sanitary management performance level of high sanitary knowledge score group was significantly higher than that of low sanitary knowledge score group (P<0.001). There was a significant positive correlation between sanitary knowledge score and sanitary management performance of school foodservice employees (P<0.01). Regression analysis showed that sanitary knowledge score of school foodservice employees had a positive effect on sanitary management performance (P<0.001). It implies that as school foodservice employees' sanitary knowledge increased, their sanitary management performance increased. In conclusion, to improve the sanitary quality of school foodservice, school foodservice employees' sanitary management performance level should be increased by improving their sanitary knowledge. So, a systematic and consistent sanitary education program should be conducted for school foodservice employees.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.475-483
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• 1994

Background: N-acetylcysteine(ACE) is used both orally and intravenously in a variety of experimental pathologies resembling human disease states which exhibit endothelial toxicity as a result of oxidative stress, including acute pulmonary oxygen toxicity, septicemia and endotoxin shock. Despite these observations in vivo, it is not certain how this thiol drug produces its protective effects. ACE is a cysteine derivative which is able to direct1y react with oxygen radicals and may also act as a cysteine and glutathione(GSH) precursor following deacetylation. In this paper, we tried to know whether the therapeutic doses of ACE can modify the inflammatory function of the neutrophils and can increase the glutathione level of plasma in chronic obstructive pulmonary disease(COPD) patients. In addition, the effect of ACE to the purified neutrophil in terms of superoxide release and glutathione synthesis were observed. Method: Firstly, we gave 600mg of ACE for seven days and compare the release of superoxide, luminol-enhanced chemiluminescence from the neutrophils, neutrophil chemotaxis, and plasma GSH levels before and after ACE treatment in COPD patients. Secondly, we observed the dose dependent effect of ACE to the purified neutrophil's superoxide release and GSH levels in vitro. Results: 1) Usual oral therapeutic doses(600mg per day) of ACE for seven days did affect neither on the neutrophil's superoxide release, chemiluminescence, chemotaxis, nor on the plasma GSH concentration in the COPD patients. 2) ACE decreases the purified neutrophil's superoxide release and increase the GSH production in dose dependent fashion in vitro. Conclusion: Despite the fact that oral ACE treatment did not affect on the neutrophil's inflammatory function and plasma GSH concentration in COPD patients in usual therapeutic doses, it decreases the superoxide release and increases the GSH production from the isolated neutrophils in high molar concentrations. These findings suggest that to obtain an antioxidative effects of ACE, it might be needed to increase the daily dosage of ACE or therapeutic duration or change the route of adminisration in COPD patients.

• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.242-249
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• 2004

Background : Because of the low sensitivity of sputum smear and culture, diagnosis of nontuberculous mycobacterium (NTM) pulmonary disease, especially in patients with bronchiectasis, is often difficult. We investigated the usefulness of bronchoscopy for the diagnosis of NTM pulmonary disease including M. avium complex (MAC) and M. abscessus in patients with bronchiectasis and multiple pulmonary nodules on chest computed tomography (CT). Methods : We reviewed 48 cases of patients who were performed bronchoscopic bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB) under suspect of NTM pulmonary disease based on CT findings of bronchiectasis and multiple nodules from April 2002 to June 2003. Results : Twenty five of the 48 patients (54%; 12 MAC, 14 M. abscessus) were diagnosed as NTM pulmonary disease on the basis of the American Thoracic Society diagnostic criteria for NTM pulmonary disease. Sixteen of the 21 patients (76%; 5 MAC, 11 M. abscessus) with 3 or more positive sputum cultures of NTM were confirmed tissue invasion by TBLB. Five of the 24 patients (21%; 4 MAC, 1 M. abscessus) who could not be diagnosed with sputum cultures were diagnosed by bronchoscopic BAL and TBLB. Conclusion : Bronchoscopy is helpful for the diagnosis of NTM pulmonary disease and confirmation of tissue invasion by NTM, not only MAC but also M. abscessus, in patients with bronchiectasis and multiple nodules on chest CT scan.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.889-894
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• 2006

Purpose : Asthma is characterized by the presence of airway hyperresponsiveness(AHR) and inflammation. The extensive eosinophil infiltration into the lung is the hallmark of asthma and contributes to the damage of respiratory epithelium during late phase airway responses. Eotaxin is the major eosinophil chemoattractant found in bronchoalveolar lavage(BAL) fluid of allergic inflammation. IL-13 has been known to induce the expression of exotaxin and eosinophilia. IL-13 also induces airway inflammation, mucus production and leads to marked fibrosis, airway remodeling and AHR. We investigated whether serum IL-13 levels can reflect the presence of airway hyperresponsiveness in children with asthma, and the relationship between serum IL-13 and eotaxin levels. Methods : Using sandwich enzyme-linked immunosorbent assay, the serum IL-13 and eotaxin levels were measured in 13 atopic asthmatics, 5 atopic non-asthmatics and 12 control subjects. Metacholine challenge tests were performed in all subjects. Airway hyperresponsiveness to metacholine was expressed as provocative concentration of metacholine causing a 20% fall in FEV1[$PC_{20}mg/mL$]. $PC_{20}$ value of 25 mg/mL was used as a cut-off for defining a AHR. Results : Serum IL-13 levels showed positive correlation with eotaxin levels. Serum IL-13 and eotaxin levels showed no differences among atopic asthmatics, atopic non-asthmatics and control subjects. And there were no differences serum IL-13 and eotaxin levels in children with and without AHR and atopy. Serum IL-13 and eotaxin levels did not correlate with $logPC_{20}$ levels. Conclusion : IL-13 is closely related to the eotaxin release. But serum IL-13 and eotaxin per se can't predict the severity of airway hyperresponsiveness. IL-13 and eotaxin may have local effect on respiratory epithelium or there can be some factors to induce airway hyperresponsiveness other than serum IL-13 in asthmatic airways.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1090-1096
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• 2002

Purpose : We evaluated the clinical manifestations, bronchoscopic findings and therapeutic effects of flexible fiberoptic bronchoscopy in atelectasis of children. Methods : Sixty six children who received bronchoscopy due to persistent atelectasis, acute severe atelectasis and incidental atelectasis on plain chest radiography were studied retrospectively. Results : The most common causative underlying disease was pneumonia(60.4%). Other underlying conditions were pulmonary tuberculosis, chronic lung disease, postoperative state, bronchial asthma and chest trauma. The most common abnormal findings were inflammatory changes such as bronchial stenosis(n=15), mucosal edema and large amount of secretion(n=14), granulation tissue( n=3) and mucus plug(n=3) although 39.4% showed normal airways. Other findings were congenital airway anomalies, endobronchial tuberculosis, extrinsic compression and obstruction by blood clot. In 32 children with pneumonia-associated atelectasis, 43.7% revealed normal airways, and the most common abnormal findings were also inflammatory changes. Eighteen out of 39 patients who received therapeutic intervention such as suctioning of secretion, bronchial washing and intrabronchial administration of N-acetylcysteine($Mucomyst^{(R)}$) had complete or partial resolution of their atelectasis. In 32 patients with pneumonia-associated atelectasis, 56.5% showed improvement by therapeutic intervention. Conclusion : In this study, atelectasis was mainly associated with inflammatory airway diseases such as pneumonia. The most common abnormal bronchoscopic findings were inflammatory changes such as mucosal edema and large amounts of secretion and bronchial stenosis, although about 40% revealed normal airway. Flexible bronchoscopy is helpful for either diagnosis or treatment, especially in pneumonia-associated atelectasis.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.841-849
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• 1996

Quality changes in carrot during storage were studied to investigate the efficiency, cooling properties and the washing and storage effects of hydrocooling method. As a result of plotting the nondimensionalized carrot temperature versus cooling time, its cooling rate coefficient was shown $-0.0171min^{-1}{\sim}-0.0121min^{-1}\;(R^{2}=0.99{\sim}0.95)$, and $-0.141min^{-1}{\sim}-0.0038min^{-1}\;(R^{2}=0.98{\sim}0.92)$ in package condition7. Rate of weight loss and change in moisture content of carrot were not significantly different by treatment conditions during storage at $5^{\circ}C$. During storage at $15^{\circ}C$, however, weight loss of hydrocooled carrot was lower than that of non-treated carrot from the 30th to 40th day. Especially, PE was more effective than tray for packaging hydrocooled carrots. Carrot pretreated wish sterilizing agent, packed with PE vinyl film and with residual water removed after hydrocooling showed a lower decaying-rate than any other carrots. Changes in Hunter L and b values of hydrocooled carrot were slower than those of non-treated one. The carotenoids contents of stored carrot $(0.736{\sim}0.780mg%)$ decreased to $9{\sim}43%$ after 40 days of storage at $5^{\circ}C$ and before 20 days of storage at $15^{\circ}C$. It could be presumed that the addition of sterilizing agent reduced the initial level of overall microbial and coliform counts and their growth rate during storage.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.207-215
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• 2020

Toxic assessment of antifouling agents (diuron and irgarol) was conducted using the fertilization and the normal embryogenesis rates of the sea urchin, Mesocentrotus nudus. Bioassessment began with male and female reproductive cell induction. White or cream-colored male gametes(sperm) and yellow or orange-colored female gametes (eggs) were acquired and fully washed, separately. Then, the fertilization and normal embryogenesis rates were measured after 10 min and 48 h of exposure to the toxicants, respectively. The fertilization and embryo development rates were greater than 90% in the control, validating the suitability of both endpoints. The normal embryogenesis rates were significantly decreased with increasing concentrations of diuron and irgarol, but no changes in the fertilization rates were observed in concentrations ranging from 0 to 40 mg L^-1. The EC₅₀ values of diuron and irgarol for the normal embryogenesis rates were 20.07 mg L^-1 and 22.45 mg L^-1, respectively. The no observed effect concentrations (NOEC) were <1.25 mg L^-1 and the lowest observed effect concentrations (LOEC) were 1.25 mg L^-1 and 2.5 mg L^-1, respectively. From these results, concentrations of diuron and irgarol over 1.25 mg L^-1 and 2.5 mg L^-1, respectively, can be considered to have toxic effects on invertebrates, including M. nudus. The ecotoxicological bioassay in this study using the noted fertilization and normal embryogenesis rates of M. nudus can be used as baseline data for the continued establishment of environmental quality standards for the effects of antifouling agents(especially diuron and irgarol) in a marine environment.

• Journal of Food Hygiene and Safety
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• v.35 no.2
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• pp.152-161
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• 2020

This study determined the removal ofrates for three types of pesticides which were spiked from Chonggak radish during the preparation of chonggak kimchi. When Chonggak radish (leaves) were brined with 10% salt solution and rinsed with water, the removal rate of the three pesticides was 43.8%, 41.9% and 89.8% for diazinon, diniconazole and dimethomorph, respectively. When Chonggak kimchi (leaves) were prepared and fermented for 4 weeks at 4℃, the removal rate of the three pesticides was 82.4%, 77.2% and 98.9% for diazinon, diniconazole and dimethomorph, respectively. Pesticide residues in chonggak radish (roots) were removed by up to 54.7-85.1% of initial concentration through brining and washing. During the fermentation of chonggak kimchi (roots) for 4 weeks at 4℃, the amount of pesticide residues was decreased by 94.0%, 91.8% and 90.0% of initial concentration for diazinon, diniconazole and dimethomorph, respectively. The highest relative removal rate by percentage for the three pesticides asreached 66.5% by salting chonggak radish (leaves). On the other hand, the highest relative removal rate by percentage of pesticides was shown during fermentation, reaching 51.8% and 55.8% for diazinon and diniconazole, respectively, in Chonggak kimchi (roots). As a result of examining the differences ofbetween the three pesticide removal rates rates according to temperature while fermentedduring fermentation of Chonggak kimchi with three pesticides for 4 weeks at 0℃ and 4℃, diazinon pesticide removal was has a high pesticide removal rate of 2.7-10.8% from fermented Chonggak kimchi (roots) at 4℃ compared to 0℃. In the other pesticides, the difference in removal rate of the pesticideresidual pesticides residues by aging temperature was found to be insignificant.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.328-338
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• 1994

Background: Effect of sulfur dioxide($SO_2$) exposure on airway is well known but little about the effect of $SO_2$ exposure on lung parenchyme. This study is to determine if short tenn exposure to $SO_2$ in concentration commonly found in industrialized environment cause potentially harmful effect on the lung parenchyme, and to evaluate the exposure time-response relationship between short tenn exposure to $SO_2$ and the inflammatory response in mouse lung. Method: 5ppm $SO_2$ gas was used and 48 mice were grouped into control(10), 30(9), 60(11), and 120 minute exposure(18) group. In each group, bronchoalveolar lavage(BAL) was done immediately after and at 1,2,3 days after exposure. Histological examination was performed in control and 120 minute exposure group. Results: 1) Cell response in bronchoalveolar lavage fluid. In 30 and 60 minute exposure group, compared to the control group, lymphocyte count has significantly increased(p<0.05) at 1 day after exposure but did not differ at 2 days after exposure. In 120 minute exposure group, also compared to the control group, there was significant increase in total cell, macrophage, and lymphocyte count at 1 day after exposure, (p<0.05) which lasted for 2 days but did not significantly differ at 3 days after exposure. 2) Histological findings in 120 minute exposure group. In the airway, mild epithelial cell damage and ciliary loss were noted but there was no evidence of inflammatory cell infiltration. Interstitial inflammatory infiltration was noted at 1 day after exposure, which lasted for 3 days after exposure and there was no evidence of edema or fibrosis in the interstitium Conclusions: These data indicate potentially noxious effect of $SO_2$ on the lung parenchyme as well as the airway at exposure level that are regarded as relatively safe, and the duration of injury depends on the exposure time.