• Analytical Science and Technology
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• v.26 no.4
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• pp.268-275
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• 2013

Many kinds of liquid spray products are used in livelihood activities these days. Spray products can be distinguished by the target to be sprayed (like into the air or on human skin (body)). Because human can be exposed to volatile organic compounds (VOC) emitted from spray products, some considerations on safety or hazard of spray products should be needed. In this study, emission characteristics of VOCs were investigated against 10 types of liquid spray products (6 skin spray and 4 air spray products). The concentrations of benzene and toluene were determined by gas chromatography/mass spectrometry (GC/MS) equipped with a thermal desorber (TD). Their average concentrations from 6 skin spray products exhibited$ 5.64{\pm}1.95$ ($mean{\pm}S.D$) and $8.52{\pm}2.89$ ppb(w), respectively. In contrast, those of 4 air spray samples had $7.30{\pm}1.31$ and $7.19{\pm}1.78$ ppb(w), respectively. If liquid contents in spray samples are completely vaporized in one cubic meter (1 m3) after spraying for 10 seconds, their mean concentrations of skin spray products are $31.7{\pm}8.80$ (benzene) and $50.5{\pm}17.1{\mu}g/Sm^3$ (toluene). In contrast, those of air spray products are $24.0{\pm}4.30$ (benzene) and $23.6{\pm}5.83{\mu}g/Sm^3$ (toluene). The estimated concentration levels of benzene from two types of products (31.7 and $24.0{\mu}/Sm^3$) exceeded the Korean atmospheric environmental guideline ($5{\mu}g/Sm^3$). The results of this study thus suggest that some measures should be made to reduce or suppress the contents of VOC in spray products.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.810-820
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• 2012

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) contents in marine sediment and edible fish (4 species) from the estuary near the Yongho wharf in Busan were determined to assess their presence and their potential health risk to the local population through fish consumption was also assessed. Levels of ${\Sigma}PCBs$ and ${\Sigma}DDTs$ in marine sediment were 3.22~197.65 and 1.77~20.27 ng/g dw, respectively. HCHs and endosulfan sulfate concentrations in bottom sediment were 1.42~6.08, 0.56~13.89 ng/g dw, respectively. The bottom sediment in the offshore of the Yongho wharf may be characterized as semi-polluted status with potential adverse marine biological effects in terms of sediment quality guidelines of US NOAA. The mean concentrations of ${\Sigma}PCBs$ in the tissues of olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis) were 67.37, 10.20, 48.26, 22.81 ng/g lw, respectively. DDTs and HCHs were also detected in all fish samples. Lifetime cancer risk and target hazard quotient to local residents due to those fish consumption were found to pose negligible cancer and non-cancer risk.

• 한국해양학회지
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• v.14 no.1
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• pp.15-25
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• 1979

A study on field bioassay test using four species of commercially important shellfish was carried out to assess the effect of pollutants and determine the extent of marine environmental pollution of the Masan Bay from 9 to 15 August 1978. Water quality analysis and planktological examination of sea water were made during the experiment and the examination gave the following results. The water temperature was so high at 31.7$^{\circ}C$ in maximum and rather subject to change on weather condition of the land than on the effect of the water mass from outer bay. The range of DO,COD and SS at the stations were 0.3-7.08cc/l, 0.07-3.31ppm and 5.5-117ppm, respectively with the high values of COD and SS at the stations 7 and 1. The concentrations of the dissolved inorganic nitrogen in sea water, NH$\sub$4/-N, NO$\sub$2/-N, NO$\sub$3/-N, and PO$\sub$4/-P were 18.90-99.80, 2.48- 19.60, 13.00-39.00 and 1.04-14.0$\mu\textrm{g}$ at/l, respectively with decrease of their values in the outer part of the Bay. The high values mentioned above were caused by the sewage and industrial activities. The effects of organic waste are increased oxygen demand, nutrient concentration, turbidity and a higher input of pathogens, leading to structural changes in the marine ecosystems and to a considerable hazard to public health. The percentage composition of phytoplankton standing crop between diatom and dinoflagellate was characterized by making a difference between the two groups in respect of location: a decrease of diatom and a increase of dinoflagellate in numerical abundance toward inner part from outer part of the bay. Namely phytoplankton organisms were composed of 80% of diatom and 20% of dinoflagellate in outer bay, on the contrary, only 4% of diatom and 96% of dinoflagellate occupied by 94% of prorocentrum micans known as tolerant species to polluted reaas in the inner bay. On the occurrence and composition of zooplankton, there are two significant communities in the bay:one is characterized by the predominance of Oithona nana and the other by Favella sp They were composed of a range from 84% to 90% of the total organisms and monotonously constituted of themselves only at most inner station 3 even small numbers. From the results mentioned above, Oithona nana, Favella and prorocentrum micans recommed themselves as valuable indicators for judging the extent of the marine pollution.During the period of the biossays Mytilus edulis showed the highest mortality and Tapes japonica the lowest one between the four test species. The highest death rate by stations was found at most inner stations 3'and 4near Masan Free Export Zone with the most sensitive response and the lowest one occured at outer station 13 where no death specimen of oyster and arkshell was found during the whole test period.As for mussel,85 percent death rate appeared after 72 hours and 100percent rate after 120hours at station 4. It was found that the significant high mortality of the test shellfish mentioned above was caused by severe pollution with mainly organic pollutants from domestic sewage and industrial wastes from the results of too much higher concentrations of dissolved inorganic nitrogen especially ammonia-N,COD,SS and lack of dissolved oxygen,and furthermore occurrence and abundance composition of Prorcentrum,Favella and Oithona nana by stations, valuable indicator species of coastal pollution by orgnic and boilogical pollutants.

• Korean Journal of Optics and Photonics
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• v.27 no.1
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• pp.1-17
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• 2016

Over the past two decades, fiber-based lasers have made remarkable progress, now having reached power levels exceeding kilowatts and drawing a huge amount of attention from academy and industry as a replacement technology for bulk lasers. In this paper we review the significant factors that have led to the progress of fiber lasers, such as gain-fiber regimes based on ytterbium-doped silica, optical pumping schemes through the combination of laser diodes and double-clad fiber geometries, and tandem schemes for minimizing quantum defects. Furthermore, we discuss various power-limitation issues that are expected to incur with respect to the ultimate power scaling of fiber lasers, such as efficiency degradation, thermal hazard, and system-instability growth in fiber lasers, and various relevant methods to alleviate the aforementioned issues. This discussion includes fiber nonlinear effects, fiber damage, and modal-instability issues, which become more significant as the power level is scaled up. In addition, we also review beam-combining techniques, which are currently receiving a lot of attention as an alternative solution to the power-scaling limitation of high-power fiber lasers. In particular, we focus more on the discussion of the schematics of a spectral beam-combining system and their individual requirements. Finally, we discuss prospects for the future development of fiber laser technologies, for them to leap forward from where they are now, and to continue to advance in terms of their power scalability.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.213-221
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• 2008

Purpose: The objective of this retrospective study was to identify predictive factors for the complete pathologic response and tumor downstaging after preoperative concurrent chemoradiotherapy for locally advanced rectal cancer. Materials and Methods: Between the years 2000 and 2008, 39 patients with newly diagnosed rectal cancer without prior evidence of distant metastasis received preoperative concurrent chemoradiotherapy followed by surgery. The median radiation dose was 50.4 Gy (range, $45{\sim}59.4\;Gy$)). Thirty-eight patients received concurrent infusional 5-fluorouracil and leucovorin, while one patient received oral capecitabine twice daily during radiotherapy. Results: A complete pathologic response (CR) was demonstrated in 12 of 39 patients (31%), while T-downstaging was observed in 24 of 39 patients (63%). N-downstaging was observed in 18 of 28 patients (64%), with a positive node in the CT scan or ultrasound. Two patients with clinical negative nodes were observed in surgical specimens. The results from a univariate analysis indicated that the tumor circumferential extent was less than 50% (p=0.031). Moreover, the length of the tumor was less than 5 cm (p=0.004), while the post-treatment carcinoembryonic antigen (CEA) levels were less than or equal to 3.0 ng/mL (p=0.015) and were significantly associated with high pathologic CR rates. The univariate analysis also indicated that the adenocarcinoma (p=0.045) and radiation dose greater than or equal to 50 Gy (p=0.021) were significantly associated with high T-downstaging, while a radiotherapy duration of less than or equal to 42 days (p=0.018) was significantly associated with N-downstaging. The results from the multivariate analysis indicated that the lesser circumferential extent of the tumor (hazard ratio [HR] 0.150; p=0.028) and shorter tumor length (HR, 0.084; p=0.005) independently predicted a higher pathologic CR. The multivariate analysis also indicated that a higher radiation dose was significantly associated with higher T-downstaging (HR, 0.115; p=0.025), while the shorter duration of radiotherapy was significantly associated with higher N-downstaging (HR, 0.028; p=0.010). Conclusion: The circumferential extent of the tumor and its length was a predictor for the pathologic CR, while radiation dose and duration of radiotherapy were predictors for tumor downstaging. Hence, these factors may be used to predict outcomes for patients and to develop further treatment guidelines for high-risk patients.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.20-34
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• 2006

This study was undertaken to assess the anthropogenic impact on trace metal concentrations (Zn, Cu, Pb, Cr, Ni, and Cd) of roadside sediments (N = 70) from No.7 national road within the watershed of Hoidong Reservoir in Pusan City and to estimate the potential mobility of selected metals using sequential extraction. We generally found high concentrations of metals, especially Zn, Cu and Pb, affected by anthropogenic inputs. Compared to the trace metal concentrations of uncontaminated stream sediments, arithmetic mean concentrations of roadside sediments were about 7 times higher for Cu, 4 times higher for Zn, 3 times higher for Pb and Cr and, 2 times higher for Ni and As. Speciation data on the basis of sequential extraction indicate that most of the trace metals considered do not occur in significant quantities in the exchangeable fraction, except for Cd and Ni whose exchangeable fractions are appreciable (average 29.3 and 25.8%, respectively). Other metals such as Zn (51.4%) and Pb (45.2%) are preferentially bound to the reducible fraction, and therefore they can be potentially released by a pH decrease and/or redox change. Copper is mainly found in the organic fraction, while Cd is highest in the exchangeable fraction, and Cr and Ni in the residual fraction. Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreases in the order of Cd>Ni>Pb>Zn>Cr>Cu. Although the total concentration data showed that Zn was typically present in potentially harmful concentration levels, the data on metal partitioning indicated that Cd, Ni and Pb pose the highest potential hazard for runoff water. As potential changes of redox state and pH may remobilize the metals bound to carbonates, amorphous oxides, and/or organic matter, and may release and flush them through drain networks into the watershed of Hoidong Reservoir, careful monitoring of environmental conditions appears to be very important.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.493-499
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• 2017

This study was conducted to monitor the current status of pesticide residues and sulfur dioxide in a total of 91 functional rice products from February to October 2016. Multi class pesticide multiresidue methods of 220 pesticides was performed by the GC/ECD, GC/NPD, GC/TOF/MS, LC/PDA, and LC/FLD. As a result of analysis, the pesticides were detected in 3 samples, representing a detection rate of 3.3%. The kind of pesticides was propiconazole and isoprothiolane used for germicide in agriculture or plant growth regulator purposes. The detected levels were 0.0340~0.0566 mg/kg, which were under the MRL (Maximum Residues Limits). The contents of sulfur dioxide in 91 samples by the Monier-Williams method were not detected. Risk assessment of pesticides evaluated using human health exposure with the ratio of EDI (Estimated daily intake) to ADI (Acceptable daily intake). %ADI (the ratios of EDI to ADI) were 0.24~1.25% with safety level.

• Journal of Nutrition and Health
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• v.56 no.2
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• pp.155-167
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• 2023

Purpose: This study investigates the association between seafood consumption and frailty according to gender in the Korean elderly. Methods: Cross-sectional data from the Seventh (2016-2018) Korea National Health and Nutrition Examination Survey was procured for this study. Data from 3,675 subjects (1,643 men and 2,032 women) aged ≥ 65 years were analyzed. Levels of seafood intake were assessed by a one-day 24-hour dietary recall, and subjects were classified into three tertiles by gender according to frailty phenotype: robust, pre-frail, and frail. Multinomial logistic regression analysis was performed to clarify the association between seafood consumption and frailty for each gender. Results: The prevalence of frailty was determined as 13.4% for men and 29.7% for women. Participants with a higher seafood intake had higher intakes of grains, fruits, and vegetables, while the intake of meat was significantly lower. In both men and women, the group with higher seafood intake showed higher energy and micronutrient intakes. The frail prevalence and frailty score were significantly low in the highest tertiles of seafood consumption compared to the lowest tertile in men and women (p < 0.001). After adjusting for confounder, the highest tertile of seafood consumption showed a decreased risk of frailty compared to the lowest tertile only in women (hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.32-0.78; p-trend = 0.008 vs. HR, 0.52; 95% CI, 0.32-0.83; p-trend = 0.008; respectively). Conclusion: Results of this study suggest that seafood consumption potentially decreases the risk of frailty in the elderly.

• Analytical Science and Technology
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• v.20 no.5
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• pp.434-441
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• 2007

The aim of this paper is to investigate composition of fatty acids in sweat on purpose of latent fingerprint detectant developing and crime evidence searching. Fingerprint from 5 male donors (aged 29-50 years) were collected. We identified fatty acid components on sweat using methylester mixture (37species) as standard fatty acid and analyzed them by GC-FID. As donor was aged, the level of total fat was found to decrease markedly (aged 20-30 years: 56.4-72.0 %, aged 50 years : 32.4-45.4 %). We identifided 28 species fatty acid, primarilly C16:0(palmitic acid), C16:1 (palmitoleic acid), C18:1n9c(oleic acid), C18:0 (stearic acid), C14:0 (tetradecanoic acid) and all sweats were found to contain C12:0 (lauric acid), C15:0 (pentadecanoic acid), C18:2n6c (linoleic acid), C18:2n6t (linolelaidic acid), C20:0 (arachidic acid), C24:0/C20:5n3 (lignoceric acid/eicosapentaenoic acid), but with differing frequencies and at varying levels. C14:1 (myristoleic acid), C15:1 (pentadecenoic acid), C21:0 (heneicosanoic acid), C22:1n9 (erucic acid) were often observed in sample. Ratio of saturated and unsaturated fatty acid was from 0.94:1 to 2.6:1. And decrease of total fatty acids components caused by loss of saturated fatty acid and monounsaturated fatty acid. In case of sweat amino acids, we detected serine ($0-31.9{\mu}L/mL$), threonine ($0-26.2{\mu}L/mL$), glycine ($0-18.9{\mu}L/mL$) and 20-30 years old, highly protein intake ratio individuals increased (10 times) than 50 years old. We observed greatly individual characterization of amino acid compounds in sweat.

• Analytical Science and Technology
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• v.36 no.6
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• pp.267-280
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• 2023

This study investigated the contents of Pb, Cd, As, and Hg for 4333 samples with 2 09 types of herbal medicines distributed in Seoul area from 2019 to 2021, and evaluated risk assessment according to medicinal part used and origin. The contents of heavy metals were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) and mercury analyzer. The average contents (mg/kg) of heavy metals by medicinal parts were 0.123 to 1.290 for Pb, 0.018 to 0.131 for Cd, 0.034 to 0.290 for As, and 0.003 to 0.015 for Hg. The contents of Pb were higher in Leaves and Whole Herbs (above-ground part) than underground part (Radix & Rhizoma) (ANOVA-test, p < 0.05). The contents of Cd were high in Leaves, Radix & Rhizoma, and Stems & Woods (ANOVA-test, p <0 .05), and exceeded regulatory limits in various types. Levels of Pb, Cd concentrations exceeding regulatory limits were observed in 8, 22 samples (8, 14 types). No sample exceeded regulatory limits of As and Hg. In the comparison between countries of origin, the contents of Cd, As, and Hg were high in imported herbal medicines (t-test, p < 0.05). As a result of the risk assessment, except for Thujae Orientalis Folium and Spirodelae Herba, the MOE values of Pb were all 1 or more, and most samples were safe. The Hazard Index (HI) for Cd, As, and Hg were evaluated to be less than 100 % even if the risk (%) of each heavy metal was added, and the risk from taking herbal medicines was evaluated to be safe.