• Journal of Environmental Health Sciences
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• v.44 no.6
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• pp.524-538
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• 2018

Objective: This study aimed to identify the size distributions of particulate matter emitted during 3D printing according to operational conditions and estimate particle inhalation exposure doses at each respiratory region. Methods: Four types of printing filaments were selected: acrylonitrile-butadiene-styrene (ABS), polylactic acid (PLA), Laywood, and nylon. A fused deposition modeling (FDM) 3D printer was used for printing. Airborne particles between 10 nm and $10{\mu}m$ were measured before, during, and after printing using real-time monitors under extruder temperatures from 215 to $290^{\circ}C$. Inhalation exposures, including inhaled and deposited doses at the respiratory regions, were estimated using a mathematical model. Results: Nanoparticles dominated among the particles emitted during printing, and more particles were emitted with higher temperatures for all materials. Under all temperature conditions, the Laywood emitted the highest particle concentration, followed by ABS, PLA, and nylon. The particle concentration peaked for the initial 10 to 20 minutes after starting operations and gradually decreased with elapsed time. Nanoparticles accounted for a large proportion of the total inhaled particles in terms of number, and about a half of the inhaled nanoparticles were estimated to be deposited in the alveolar region. In the case of the mass of inhaled and deposited dose, particles between 0.1 and $1.0{\mu}m$ made up a large proportion. Conclusion: The number of consumers using 3D printers is expected to expand, but hazardous emissions such as thermal byproducts from 3D printing are still unclear. Further studies should be conducted and appropriate control strategies considered in order to minimize human exposure.

• Journal of Marine Life Science
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• v.2 no.2
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• pp.49-55
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• 2017

Four chemical treatments with hydrogen peroxide (H₂O₂), copper sulfate (CuSO₄), potassium permanganate (KMnO₄) and chlorine (Cl₂) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO₄ and Cl₂. H₂O₂ did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl₂ did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl₂ concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl₂ did not significantly reduce any types of solid matter in this study, while KMnO₄ seemed to reduce some extent volatile dissolved solid in the fish pond.

• Radiation Oncology Journal
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• v.29 no.4
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• pp.260-268
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• 2011

Purpose: To evaluate the treatment outcome and prognostic factor after postoperative radiotherapy in retroperitoneal sarcoma. Materials and Methods: Forty patients were treated with surgical resection and postoperative radiotherapy for retroperitoneal sarcoma from August 1990 to August 2008. Treatment volume was judged by the location of initial tumor and surgical field, and 45-50 Gy of radiation was basically delivered and additional dose was considered to the high-risk area. Results: The median follow-up period was 41.4 months (range, 3.9 to 140.6 months). The 5-year overall survival (OS) was 51.8% and disease free survival was 31.5%. The 5-year locoregional recurrence free survival was 61.9% and distant metastasis free survival was 50.6%. In univariate analysis, histologic type (p = 0.006) was the strongest prognostic factor for the OS and histologic grade (p = 0.044) or resection margin (p = 0.032) had also effect on the OS. Histologic type (p = 0.004) was unique significant prognostic factor for the actuarial local control. Conclusion: Retroperitoneal sarcoma still remains as a poor prognostic disease despite the combined modality treatment including surgery and postoperative radiotherapy. Selective dose-escalation of radiotherapy or combination of effective chemotherapeutic agent must be considered to improve the treatment result especially for the histopathologic type showing poor prognosls.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.474-481
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• 1985

Radurization effects on fried fish meat paste with Co-60 gamma irradiation at 0-5 kGy and physicochemical aspects of the stored samples at low ($3{\pm}1^{\circ}C$, LT) and room ($10-20^{\circ}C$, RT) temperatures were investigated. The initial microbial loads of the samples were $2.2{\times}10^3/g$ in total bacterial count, $2.8{\times}10^2/g$ in yeasts & molds, and $1.0{\times}10^2/g$ in coliform group, respectively. An irradiation dose of more than 3 kGy was shown to be effective for the radurization of stored samples and there is no apparent difference between air and vacuum packaging groups. The chemical components related to the quality underwent similar changes in the nonirradiated and irradiated groups; however, as the storage time was prolonged the quality of nonirradiated samples rapidly deteriorated. Textural parameters of the samples were little affected by the applied doses, and sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend the shelf-life of fried fish meat paste up to 2 times at RT and 3 to 4 times at LT, respectively compared with the nonirradiated control.

• Journal of Radiation Industry
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• v.6 no.4
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• pp.299-304
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• 2012

The quality properties of freeze-dried apples, pears, strawberries and pineapples gamma-irradiated at 0, 1, 2, 3, 4, and 5 kGy were evaluated to develop germ-free products for immuno-compromised patients. The initial count of total aerobic bacteria in non-irradiated apples, pears, strawberries and pineapple was 2.5, 3.1, 2.6, and $3.2{\log}\;CFU{\cdot}g^{-1}$, respectively. Microorganisms were not observed in apples after 1 kGy, in pears and strawberries after 4 kGy, and in pineapples at 5 kGy within a detection limit of $10{\log}\;CFU{\cdot}g^{-1}$. In addition, the sterilization of each sample was confirmed at the same dose. The score for the overall acceptance of freeze-dried fruit irradiated at a sterilization dose was 5.5 for apples, 4.1 for pineapples, and 4.0 for the other fruits, whereas that of non-irradiated control sample was 5.6 for apples, 5.2 for pears, and 5.8 for strawberries and pineapples with a 7-point scale. As a result, gamma irradiation of 1 kGy for apples, 4 kGy for strawberries and pears, and 5 kGy for pineapples is sufficient to sterilize each freeze-dried fruit with acceptable sensory properties.

• Korean Journal of Clinical Pharmacy
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• v.11 no.1
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• pp.19-29
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• 2001

Teicoplanin, a glycopeptide antibiotic, has potential for use as an alternative to vancomycin in the treatment of gram-positive bacterial infections. However, unlike vancomycin, there is a lack of study on teicoplanin's efficacy and safety and the guideline for its use is not available, yet. The objective of this study was to investigate and evaluate the pattern of teicoplanin usage in a university hospital. A retrospective study was performed on 72 adult patients, who took teicoplanin for 3 continuous days at D. University hospital from 1 January 1999 to 30 June 2000. The microorganisms treated with teicoplanin were methicillin-resistant Staphylocorcus aureus $(69\%)$, coagulase-negative Staphylococci $(12\%)$, Enterococcus $(4\%)$, vancomycin-resistant Enterococci $(2\%)$, Streptococci $(2\%)$, and Bacillus $(1\%)$. The types of infection treated with teicoplanin were surgical wound infection $(58\%)$, lower respiratory infection $(11\%)$, bactremia $(7\%)$, urinary tract infection $(5\%)$, pleural fluid infection $(4\%)$, and peritoneal fluid infection $(2\%)$. The mean duration of teicoplanin usage was 16.5 days and teicoplanin was used with 1.4 other antibiotics, which were aminoglycosides (isepamicin, amikacin, netilmicin, astromicin) or quinolones (ciprofloxacin, tosufloxacin) or the third generation cephalosporin (ceftazidime). Only 24 cases $(28.6\%)$ met with the criteria for the justification of use, and the rest of 60 cases $(71.4\%)$ did not meet the criteria. In 84 cases $(100\%)$, blood culture tests were performed prior to the initial dose of teicoplanin. In 83 cases $(99\%)$, serum creatinine were conducted before the initial doses. In 45 cases $(53.6\%)$, serum creatinine was monitored at least twice weekly. In 55 cases $(65.5\%)$, WBC was tested at least twice weekly. In 84 cases $(100\%)$, body temperature was monitored at least once per nursing shift. In 15 cases out of 56 cases, maximum temperature decreased at least 1 degree within 3 days of teicoplanin use. In 15 case out of 35 cases, WBC values were within the normal range after treatment. In 23 cases $(27.4\%)$, dosage regimen was appropriate. Drug-related adverse effects were reported in 13 cases. Nephrotoxicity (progressively increasing SCr. or sustained SCr increase of $\geq$0.5 mg/dl from baseline) was noted in five cases. Neutropenia (absolute neutrophil count <1,500 $cells/mm^3$) was noted in one case and eosinophilia (total eosinophil count >350 $cells/mm^3$) was noted in seven cases. A more strict control on use of teicoplanin is required, considering that teicoplanin is categorized as one of restricted antibiotics.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.228-234
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• 1997

Squamous cell carcinoma originating in the parotid gland has rare occurrence. The primary squamous cell carcinoma of the parotid gland comprise about 0.3% and 9.8% of all parotid malignant tumor. We investigated the clinical behavior and treatment outcome of patients with primary squamous cell carcinoma of the parotid gland. We reviewed all cases of possible primary squamous cell carcinoma of the parotid gland treated at Yonsei Cancer Center, Seoul, Korea, from 1981 through 1995. A total of 128 had primary parotid malignancy. Metastatic squamous cell carcinoma and mucoepidermoid carcinoma were excluded in this study. Ten cases of primary squamous cell carcinoma of the parotid gland were identified. 6 cases of them are men & 4 cases are women. The age of patients ranged from 31 to 68 years with median age of 55 years. On physical examination, 5 cases had palpated cervical neck node and 6 cases had facial nerve palsy. Staging was done according to the current guidelines established by the American Joint Committee on Cancer (1992). Two cases were stage I, 1 in stage III, and 7 in stage IV. Six cases were performed operation and postoperative radiation therapy. Four cases were treated by curative radiation therapy, dose of more than 65 Gy on parotid gland region. The 5 year actual survival rate and the 5 year disease free survival rate were 30.8%, and 40.0%. Initial complete response rate was 70% for all patients. Local failure were occurred 3 of 7 patients with local controlled cases, failure sites were primary site, ipsilateral cervical neck node, contralateral supraclavicular node. Most recurrences developed within 1 year of initial treatment. Distant metastasis was appeared 2 of 3 patients who did not achieved local control. Primary squamous cell carcinoma of the parotid gland occured infrequently. A retrospective study at the Yonsei Cancer Center indicates incidence of 7.8%. At diagnosis, advanced stage, neck node presentation, facial nerve paralysis were associated with a poor prognosis. These results may suggested that radical surgical excision may be treatment of choice and that planned postoperative radiotherapy may be bendicial for reducing locoregional recurrence rates.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.663-670
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• 2006

The present study was performed to investigate the effect of plant type recombinant porcine somatotropin (pST) adminstration on growth performance and blood profile of finishing pigs. Forty-eight Landrace barrows weighing 78 kg were employed for six week growth trial. Twelve barrows were allocated into various rpST types ; the control (CONT), the 4:1 type rpST (TRT 1), the 1:1 type rpST (TRT 2); and the 4:1 type rpST group(TRT 3) respectively. CONT group were not planted rpST. TRT 1 group was treated with rpST once a week for 6 weeks. Each dose contained the rpST equivalent to 100mg from initial to two weeks and 125mg from three weeks to finial week. TRT 2 and TRT 3 groups were planted rpST four times contained the rpST equivalent to 100mg during trial period from initial to two weeks, and 125 mg from three weeks, to four weeks, respectively. All pigs were fed a commercial feed containing 0.9% lysine ad lib. Daily gain increased by 19.4% in TRT 1(p<0.05) compared to the CONT. rpST improved feed/gain by 13.4～28.9% in all treatment groups(p<0.05). Back fat thickness of the all rpST treated groups were 23.3～29.2% thinner than that of the CONT. These results indicated that the rpST stimulated growth performance in finishing pigs and plant type rpST could be used as a growth stimulant for finishing pigs.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.574-579
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• 2008

To develop a yogurt for sensitive consumer such as infants, children or immuno-compromised patients using gamma irradiation, the effects of gamma irradiation on the microbiological, chemical, and sensory quality in a commercial plain yogurt were investigated. No viable coliform bacteria were detected in the sample and approximately a 6 decimal reduction was achieved in the number of total aerobic bacteria by irradiation at 5 kGy. The initial population of lactic acid bacteria observed in the commercial plain yogurt was 8.95 log CFU/g. Gamma irradiation significantly reduced the initial microbial level to 6.47 and 2.85 log CFU/g after irradiation at 1 and 3 kGy, respectively (p<0.05). However, irradiation dose up to 5 kGy could not completely eliminate the lactic acid bacteria in commercial plain yogurt. pH, color, lactose and lactic acid content, and sensory quality were not affected by irradiation treatment and storage. Our results suggest that irradiation can improve the microbial quality of commercial plain yogurt without impairing the physicochemical and sensory quality.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.380-386
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• 2000

Electron beam (EB) was applied to study the sterilizing techniques for powdered red pepper and ginger by determining their quality over gamma radiation (GR) from the microbiological and organoleptic points of view. The samples showed high microbial loads, such as $10^5{\sim}10^6\;CFU/g$ in total aerobic bacteria, negligible levels in yeasts & molds and $10^2\;CFU/g$ in coliforms. EB irradiation at 5 kGy resulted in the reduction of microbial loads by 2 to 3 log cycles, thereby decreasing the levels of total bacteria to $10^2{\sim}10^3\;CFU/g$ and resulting in negative in coliforms. Decimal reduction doses $(D_{10})$ value on the initial bacterial loads in red pepper were $1.50{\sim}1.54\;kGy$ in EB and $1.68{\sim}1.80\;kGy$ in GR, while powdered ginger showed $1.30{\sim}2.27\;kGy$ in EB and $1.45{\sim}2.77\;kGy$ in GR, respectively. EB and GR showed a similar effect on microbial decontamination for both samples. Microbial populations in stored samples for 4 months at room temperature were not remarkably different from the initial loads in all samples. Irradiation caused little changes in Hunter's color parameters, but that were changable during storage. Sensory evaluations on color and odor of powdered samples indicated that no significant differences were observed among the all samples compared. These results revealed that EB irradiation at optimal dose levels for microbial control was not detrimental to the sensory quality of powdered red pepper and ginger.