• 한국환경보건학회지
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• 제44권6호
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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.

• 한국해양생명과학회지
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• 제2권2호
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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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• 제29권4호
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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.

• 한국식품과학회지
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• 제17권6호
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• pp.474-481
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• 1985

튀김어묵의 위생적인 유통과 보존기간 연장을 목적으로 시료에 0-5kgy 범위에 감마선을 조사한 뒤 $3{\pm}1^{\circ}C$의 저온과 $10{\sim}20^{\circ}C$의 실온에 저장하면서 변패의 원인이 되고 있는 미생물의 살균효과와 저장중 생육상태 및 어묵의 품질에 관련된 이화학적 특성변화를 검토하였다. 튀김어묵의 초기 미생물 오염도는 총세균 $2.2{\times}10^3/g, 효모 및 곰팡이가 $2.8{\times}10^2/g, 대장균군이 $1.0{\times}10^2/g$ 수준이었으나 3kGy 정도의 감마선 조사로서 감균효과가 우수하였고 공기포장과 탈기포장간의 차이는 현저하지 않았다. 저장중 시료의 pH, TBA가 휘발성 염기질소량의 변화는 조사고와 비조사구가 유사한 경향이거나 저장기간의 경과에 따라 조사구가 다소 우수하였으며, 적정선량 조사는 시료의 texture에 영향을 주지 않았다. 저장기간 중 진공포장된 시료의 관능시험 결과에서 3kGy의 감마선 조사는 비조사구에 비해 튀김어묵의 신선도를 실온에서는 약 2배, 저온에서는 $3{\sim}4$배 정도 연장시킬 수 있었다.

• 방사선산업학회지
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• 제6권4호
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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.

• 한국임상약학회지
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• 제11권1호
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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.

• 대한두경부종양학회지
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• 제13권2호
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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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• 제48권5호
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• pp.663-670
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• 2006

국내에서 제조된 서방출형 유전자재조합 돼지 성장호르몬 (porcine somatotropin; pST)이 돼지의 성장과 등지방두께에 미치는 영향을 구명하기 위해 평균체중이 78kg인 랜드레이스 거세돈 48두를 공시하여 대조구, 4:1제형 rpST구 (6회 투여), 1:1제형 rpST구 (4회 투여), 4:1제형 rpST구 (4회 투여)에 각각 12두씩 배치하였다. 대조구는 pST를 투여하지 않았고, rpST 처리구는 1주일에 1회, 목 근육에 서방형 제재를 주입하였는데, 6회 투여구는 개시부터 2주까지는 100mg을, 3주부터 6주까지는 125mg을, 4회 투여구는 개시부터 2주까지는 100mg을, 3주부터 4주까지는 125mg을 투여하였다. 시험사료는 라이신 함량이 0.9%인 시판 육성돈사료를 무제한 급여한 결과 (주) LG 화학에서 제조한 서방출형 유전자재조합 pST는 증체량 및 사료요구율을 개선시켜 생산성 향상과 등지방두께 감소로 육질이 향상되었다.

• 한국축산식품학회지
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• 제28권5호
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• pp.574-579
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• 2008

본 연구는 면역력이 약한 영 유아, 면역결핍환자 등 민감한 소비자를 위한 요구르트를 개발하기 위한 기본적인 사항을 평가하기 위하여 시판 중인 요구르트에 감마선 조사를 하여 저장 기간에 따른 품질 평가를 하였다. 요구르트의 초기 총균수 및 젖산균수는 각각 8.82 및 8.95 log CFU/g 수준이었으며, 조사선량의 증가에 따라 유의적으로 감소하여 5 kGy의 선량에서 약 6 log cycle의 감균 효과를 보였다. 요구르트의 pH, 색, 젖산 및 유당함량 측정 결과 감마선 조사 및 저장기간에 따른 유의적인 차이는 없는 것으로 확인되었다. 또한 요구르트의 관능 평가 결과 역시 감마선 조사 및 저장기간에 따른 기호도 차이는 없는 것으로 확인되었으나, 색의 경우에 감마선 조사시료가 유의적으로 높은 결과를 얻었다. 따라서 감마선 조사 기술은 요구르트의 품질변화를 최소화하면서 미생물학적 안전성을 확보하고, 추후 면역력이 약한 영 유아 및 환자 등 민감한 소비자를 위한 발효유 제품을 제조하는 기술로 적용하는데 효과적이라고 판단된다.

• 한국식품과학회지
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• 제32권2호
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• pp.380-386
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• 2000

향신료의 살균기법을 연구할 목적으로 전자선(electron beam) 이용하여 고추 및 생강 분말의 미생물학적 및 관능적 품질에 미치는 영향을 감마선과 비교 평가하였다. 사용된 시료의 총세균은 $10^5{\sim}10^6\;CFU/g$, 효모 및 곰팡이는 $0{\sim}10^3$의 수준이었고, 대장균군은 $0{\sim}10^2\;CFU/g$ 정도로 혼입되어 있었다. 전자선 조사(5 kGy)는 일반세균을 $2{\sim}3\;log$ cycles 정도 감소시킬 수 있었고, 대장균군은 2.5 kGy 조사에서도 검출되지 않았다. 초기 미생물 농도를 90% 사멸시키는데 필요한 조사선량$(D_{10}\;value)$을 계산하여 보았을 때, 고추분발의 경우 전자선 $1.50{\sim}1.54\;kGy$, 감마선 $1.68{\sim}1.80\;kGy$ 범위였고, 생강분말에서는 전자선 $1.30{\sim}2.27\;kGy$, 감마선 $1.45{\sim}2.77\;kGy$로 시료의 미생물 농도와 에너지의 종류에 따라 다소 상이한 방사선 감수성을 나타내었다. 살균처리 후 실온에서 4개월 간 저장된 시료의 미생물 농도는 처리구간에 큰 차이 없이 증식현상을 거의 나타나지 않았다. 시료의 기계적 색도(Hunter's color)는 방사선 조사에 의한 영향은 거의 없었고, 4개월 저장에 따른 영향은 크게 나타났다 향신료의 색깔 및 냄새에 대한 관능검사에서 살균선량의 전자선 조사는 고추 및 생강 분말의 관능적 품질에 대하여 안정한 것으로 나타났다.