• Journal of Preventive Medicine and Public Health
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• 제47권1호
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• pp.18-26
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• 2014

The purpose of this study was to establish food ingestion factors needed to assess exposure to contaminants through food ingestion. The study reclassified the raw data of the Korean National Health and Nutrition Examination Survey in 2001 into 12 subcategories including grain products, meat products, fish and shellfish, and vegetables for international comparability of exposure evaluation. The criteria for food intake calculation were unified according to the characteristics of food groups, and recommended values for food ingestion factors were calculated through moisture correction and recategorization of cooked, processed, and mixed foods for each group. The average intake rate for grain and grain products was 6.25 g/kg-d per capita and the men's intake rate was approximately 8% higher than that of the women. The average intake rate of meat and meat products was 1.62 g/kg-d per capita and the men's intake rate was 30% higher than that of the women, on average. The average intake rate of fish and shellfish was 1.53 g/kg-d per capita, and the age groups of 1 to 2 and 3 to 6 recorded higher capita intake rates than other age groups, 2.62 g/kg-d and 2.25 g/kg-d, respectively. The average intake rate of vegetables was 6.47 g/kg-d per capita, with the age group of 1 to 2 recording the highest per capita intake rate of 9.79 g/kg-d and that of 13 to 19 recording the lowest mean. The study also offers recommended values for food ingestion factors of other food groups by gender, age, and region. The food ingestion exposure factors will need future updates in consideration of ongoing changes in food consumption behavior.

• Journal of Yeungnam Medical Science
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• 제40권4호
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• pp.373-380
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• 2023

Background: The association between dental amalgam fillings and urine mercury concentrations was investigated in this study to assess the health risks associated with dental amalgams. Methods: This cross-sectional study included 99 women in their 20s who visited the dental clinic in Daegu, Korea. The 99 participants were composed of 68 subjects who had dental amalgam fillings (exposure group) and 31 subjects who did not have dental amalgam fillings (nonexposure group). Oral examinations were conducted by a single dental hygienist, sociodemographic features were investigated as confounding variables, and urine mercury concentrations were measured using an automatic mercury analyzer. Results: The mean±standard deviation of the urine mercury concentrations of the exposure and nonexposure groups were 1.50±1.78 ㎍/g creatinine and 0.53±0.63 ㎍/g creatinine, respectively. The exposure group showed significantly higher levels than the nonexposure group (p<0.01). The urine mercury concentration significantly increased with an increase in the number of teeth filled with amalgam, cavity surfaces involved, and number of defective amalgam fillings, and according to the latest exposure time (p<0.001). In the multiple regression analysis of amalgam-related factors and urine mercury concentrations after correction for confounding factors, the urine mercury concentration in the group with six or more amalgam-filled teeth, 11 or more cavity surfaces, and two or more defective amalgams was significantly higher than that in the nonexposure group (p<0.001). Conclusion: According to this study, exposure to dental amalgams was confirmed to significantly affect urine mercury concentrations.

• 대한소아치과학회지
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• 제31권1호
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• pp.34-40
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• 2004

상악 전치의 맹출장애는 임상적으로 비교적 흔한 치열발육 이상으로 환자측에서 인지하기 쉬우며 심미적, 사회 심리적으로 중요한 문제가 될 수 있다. 맹출장애의 치료방법으로는 주기적 관찰, 공간 확보, 치은 절제술을 포함한 단순 노출, 교정적 견인, 외과적 노출과 교정적 견인의 병행, 발거 후 자가치아이식 등 여러 방법이 있다. 이 중 적절한 치료방법을 선택하기 위해서는 우선 환자의 내과적, 치과적 병력을 고려해야 하고 치아의 위치, 상태, 치근 형성정토 및 만곡여부, 맹출을 위한 공간 확보 여부, 주위 치조골 및 치주조직의 상태, 견인 방법, 이동에 소요되는 기간 등을 고려해야 한다. 저자는 상악 전치부의 맹출장애를 보이는 두 증례를 치험한 바, 첫 번째 증례는 상악 우측 중절치의 이소맹출과 우측 견치의 맹출지연을 주소로 내원한 환자로서, 견치를 노출시킨 후 견인을 시행하였으며 현재 우측 중절치를 배열중이다. 두 번째 증례는 상악 좌측 중절치의 맹출지연을 주소로 내원한 환자로서, 상악 좌측 중절치를 발거 한 후 자가치아이식을 시행하였다. 위 증례를 통해서 치아의 맹출력을 기대할 수 없거나 맹출방향이 비정상적인 경우에는 외과적 노출과 견인을 동반한 방법을 우선 적용할 수 있으나, 치아의 위치 이상이 심각하거나 치근의 위치가 과도하게 이탈된 경우에는 자가치아이식을 포함한 외과적 술식이 맹출유도에 도움이 된다는 사실을 확인하였다.

• Archives of Plastic Surgery
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• 제36권6호
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• pp.743-749
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• 2009

Purpose: Many researches about various surgical method for blepharoptosis have already been introduced. But researches for complications after blepharoptosis correction is relatively insufficient. So, this study was performed to recognize common complications that arised depending on the severity of blepharoptosis, levator function and surgical method. Methods: 250 patients who have underwent surgical treatment for blepharoptosis from 1987 to 2006 were employed in this study. Patients were categorized by severity of blepharoptosis, levator function and surgical method that has been used. Complications after blepharoptosis correction were analyzed. Result: Total of 64 patients had occurred complications, the specifics are as following; undercorrection 22, asymmetry 13, overcorrection 12, lagophthalmos 4, abnormal eyelid contour 4, exposure keratitis 3, ectropion 2, inclusion cyst 2, infection 1 and conjunctival prolapse 1. Among above patients, 3 patients had two kinds of complications. 21 patients was underwent secondary surgery due to complication. Conclusion: Evaluating the outcomes of the secondary surgery, the early correction was better than the late correction. The most of the complications were recovered through conservative and surgical treatments. The most of the complications (47 patients) were undercorrection, asymmetry, overcorrection and took 73.4% of the total complications. The more severe the blepharoptosis and the more poor the levator function, the rate of complications were higher. According to the operation methods, most complications were occurred in levator operation, frontalis transfer and OOM flap.

• Archives of Plastic Surgery
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• 제36권2호
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• pp.167-173
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• 2009

Purpose: The key points of treatment of cryptotia are the elevation of invaginated ear helix and the correction of deformed cartilage. Prevention of stabilized cartilage contouring from returning to the previous state is also important. The authors carried otoplasty by modified Onizuka's method or Ohmori's method that conchal cartilage graft or high density polyethylene implant(MEDPOR$^{(R)}$) graft served as fixation after spreading posterior aspect of adhered antihelix and a splint for prevention of recurrence of cartilage deformities. The aim of this study is to reveal the availability of the high density polyethylene implant(MEDPOR$^{(R)}$) graft for the correction of cryptotia. Methods: We have repaired 17 cryptotic deformities using cartilage graft from cavum of concha(12 cases) or high density polyethylene implant(5 cases) for correction of deformed cartilage. We investigate the operative time, complications, and satisfaction of postoperative ear shape on both autogenous cartilage graft group and high density polyethylene implant graft group. Results: There was 1 case of reinvagination on autogenous cartilage graft group. Implant exposure was occurred on high density polyethylene implant graft group, as 1 case. These were statistically no differences between autogenous cartilage graft group and high density polyethylene implant graft group to the satisfaction of ear shape. Conclusion: High density polyethylene implant(MEDPOR$^{(R)}$) present an alternative to autogenous material as they allow of fibrovascular ingrowth, leading to stability of the implant and decreased infection rates. The correction of deformed cartilage by using the high density polyethylene implant(MEDPOR$^{(R)}$) is a good option for the treatment of cryptotia.

• 대한두개안면성형외과학회지
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• 제17권3호
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• pp.119-127
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• 2016

Background: Conventional correction of malunioned zygoma requires complete regional exposure through a bicoronal flap combined with a lower eyelid incision and an upper buccal sulcus incision. However, there are many potential complications following bicoronal incisions, such as infection, hematoma, alopecia, scarring and nerve injury. We have adopted a zygomaticofrontal suture osteotomy technique using transconjunctival incision with lateral paracanthal extension. We performed a retrospective review of clinical cases underwent correction of malunioned zygoma with the approach to evaluate outcomes following this method. Methods: Between June 2009 and September 2015, corrective osteotomies were performed in 14 patients with malunioned zygoma by a single surgeon. All 14 patients received both upper gingivobuccal and transconjunctival incisions with lateral paracanthal extension. The mean interval from injury to operation was 16 months (range, 12 months to 4 years), and the mean follow-up was 1 year (range, 4 months to 3 years). Results: Our surgical approach technique allowed excellent access to the infraorbital rim, orbital floor, zygomaticofrontal suture and anterior surface of the maxilla. Of the 14 patients, only 1 patient suffered a complication-oral wound dehiscence. Among the 6 patients who received infraorbital nerve decompression, numbness was gradually relieved in 4 patients. Two patients continued to experience persistent numbness. Conclusion: Transconjunctival incision with lateral paracanthal extension combined with upper gingivobuccal sulcus incision offers excellent exposure of the zygoma-orbit complex, and could be a valid alternative to the bicoronal approach for osteotomy of malunioned zygoma.

• 한국의학물리학회지:의학물리
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• 제19권1호
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• pp.49-55
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• 2008

본 연구는 MDCT에서 선량을 측정하는데 사용되는 ionization chamber의 calibration 전과 후의 calibration factor에 따른 선량과 촬영실의 온도, 기압의 보정(correction factor) 적용 유무에 따른 $CTDI_w$를 비교 분석하는데 있다. 2007년 3월 21일에 교정된 Model 2026C electormeter (RADICAL 2026C, USA)를 이용한 MDCT (GE light speed plus 4 slice, USA)와 head and body CT dosimetry phantom을 사용하여 측정된 값을 비교 분석하였다. 결과는 calibration factor와 주변 온도, 압력의 correction factor를 보정 해 준 $CTDI_w$ 값이 보정을 하지 않고 계산된 값보다 $0.479{\sim}3.162mGy$의 범위만큼 더 많은 선량 값이 계산되었고 실제 병원에서 사용하는 복부 일반 CT (abdomen routine CT) 조건에서의 환자선량을 측정한 결과 factor적용 전과 후의 유효선량 차는 최고 0.7 mSv의 차이가 남을 확인 할 수 있었다. 이러한 결과는 ionization chamber의 calibration과 촬영실 주변 온도와 압력이 환자선량의 측정과 계산에 중요한 요소임을 알 수 있다. 따라서 정확한 환자 선량 측정을 위해서는 촬영실 주변 온도와 압력뿐만 아니라 습도 및 recombination factor, x-ray beam quality 특성, 촬영조건(exposure conditions), 측정부위(scan region) 등에 대한 보정 factor들의 정확한 정보를 알아야 한다.

• 한국산업보건학회지
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• 제22권3호
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• pp.175-183
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• 2012

Objectives: This study developed a harmonized method for risk assessment based on the Hazard & Risk Evaluation of Chemicals (HREC) according to the Industrial Safety and Health Act (ISHA). Methods: Three preliminary studies, performed during 2010 and 2011 by the Occupational Safety and Health Research Institute and three academic research groups, were compared. The differences in risk assessment, especially in the dose-response assessment method, were analyzed. A new harmonized method for dose-response assessment was suggested and its applicability for the HREC was examined. Results: Considering the various steps of each dose-response assessment, the equivalent steps in quantitative correction, uncertainty factor 2 (UF2) for intra-species uncertainty, and UF3 for the experimental period in the uncertainty correction were relatively high. Using our new method, the total correction values (quantitative correction plus uncertainty correction) ranged from 72~15,789 to 30~60, and the ratio of the threshold limit value (TLV) to the reference concentration decreased from 12.8~1900 to 5.4~11.8. Furthermore, when we performed risk characterization by our new method, hazard quotient (HQ) values for chloroethylene, epichlorohydrin, and barium sulfate became 3.0, 14.1, and 1.13 respectively, whereas three previous studies reported HQ values of 7.1, 4580, and 87.3 considering reasonable maximum exposure (RME) conditions. HQs of the three chemicals were calculated to be 0.6, 2.4, and 0.1 respectively, when compared to their TLVs. Conclusions: Our new method could be applicable for the HREC because the total correction values and the ratio of TLVs were within reasonable ranges. It is also recommended that additional risk management measures be applied for epichlorohydrin, for which the HQ values were greater than 1 when compared with both reference values and the TLV. Our proposed method could be used to harmonize dose-response assessment methods for the implementation of risk assessment based on the HREC according to ISHA.

• 한국환경과학회지
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• 제17권6호
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• pp.591-599
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• 2008

In order to support the development of wind farms in Jejudo, a wind resource database for Jejudo has been established using a meteor-statistical analysis of KIER(Korea Institute of Energy Research) met-mast measurements and KMA(Korea Meteorological Administration) weather data. The analysis included wind statistics, tower shading, an exposure category classification using satellite images, the effect of atmospheric stability on the wind profile exponent, and a correlation matrix of wind speed to gain an understanding of the meteorological correlation between long-term weather observation stations and short-term met-mast measurements. The wind resource database for Jejudo, is to be provided as an add-on to Google $Earth^{TM}$, which is expected to be utilized as a guideline for the selection of an appropriate reference site for long-term correction in the next wind farm development project.

• 천문학회지
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• 제49권6호
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• pp.289-293
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• 2016

We investigate the long-term spatial drift of the center and the temporal variation of the shutter delay time map of Y4KCam mounted on the CTIO 1.0 m telescope. We have collected shutter delay time maps over eight years as a part of our long-term survey program. We find that the center of the shutter delay time map can drift up to $450{\mu}m$, equivalent to ${\approx}30pixels$, on the CCD. This effect can result in a small amount of error in integration time without the proper shutter delay time correction, but it does not appear to cause any significant problems in photometric measurements. We obtain a mean shutter delay time of $69.1{\pm}0.8$ ms and find no temporal variation of the shutter delay time of Y4KCam over eight years, indicative of the mechanical stability of the shutter. We suggest that using a master shutter delay time correction frame would be sufficient to achieve high precision photometry, which does not exceed photometric errors ${\approx}1.7mmag$ across the CCD frame for exposure times longer than 1 s.