• Title/Summary/Keyword: Dilution Factors

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Scientific review of the aesthetic uses of botulinum toxin type A

  • Park, Mee Young;Ahn, Ki Young
    • Archives of Craniofacial Surgery
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    • v.22 no.1
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    • pp.1-10
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    • 2021
  • Botulinum toxin type A (BoNT-A), onabotulinumtoxinA (Botox) was approved by the United States Food and Drug Administration for temporary improvement of glabellar lines in patients 65 years and younger in 2002, and has also been used widely for aesthetic purposes such as hyperhidrosis, body shape contouring, and other noninvasive facial procedures. BoNT-A inhibits presynaptic exocytosis of acetylcholine (ACh)-containing vesicles into the neuromuscular junction at cholinergic nerve endings of the peripheral nervous system, thereby paralyzing skeletal muscles. ACh is the most broadly used neurotransmitter in the somatic nervous system, preganglionic and postganglionic fibers of parasympathetic nerves, and preganglionic fibers or postganglionic sudomotor nerves of sympathetic nerves. The scientific basis for using BoNT-A in various cosmetic procedures is that its function goes beyond the dual role of muscle paralysis and neuromodulation by inhibiting the secretion of ACh. Although the major target organs for aesthetic procedures are facial expression muscles, skeletal body muscles, salivary glands, and sweat glands, which are innervated by the somatic or autonomic nerves of the peripheral cholinergic nerve system, few studies have attempted to directly explain the anatomy of the areas targeted for injection by addressing the neural physiology and rationale for specific aesthetic applications of BoNT-A therapy. In this article, we classify the various cosmetic uses of BoNT-A according to the relevant component of the peripheral nervous system, and describe scientific theories regarding the anatomy and physiology of the cholinergic nervous system. We also review critical physiological factors and conditions influencing the efficacy of BoNT-A for the rational aesthetic use of BoNT-A. We hope that this comprehensive review helps promote management policies to support long-term, safe, successful practice. Furthermore, based on this, we look forward to developing and expanding new advanced indications for the aesthetic use of BoNT-A in the future.

Spatial distribution of wastewater treatment plants in diverse river basins over the contiguous United States

  • Soohyun Yang;Olaf Buettner;Yuqi Liu;Dietrich Borchardt
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.142-142
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    • 2023
  • Humans inevitably and continuously produce wastewater in daily life worldwide. To decrease the degradation of river water bodies and aquatic ecosystem therein, humans have built systems at different scales to collect, drain, and treat household-produced wastewater. Particularly, municipal wastewater treatment plants (WWTPs) with centralized controls have played a key role in reducing loads of nutrients in domestic wastewater for the last few decades. Notwithstanding such contributions, impaired rivers regarding water quality and habitat integrity still exist at the whole river basin scale. It is highly attributable to the absence of dilution capacity of receiving streams and/or the accumulation of the pollutant loads along flow paths. To improve the perspective for individual WWTPs assessment, the first crucial step is to achieve systematic understanding on spatial distribution characteristics of all WWTPs together in a given river basin. By taking the initiative, our former study showed spatial hierarchical distributions of WWTPs in three large urbanized river basins in Germany. In this study, we uncover how municipal WWTPs in the contiguous United States are distributed along river networks in a give river basin. The extended spatial scope allows to deal with wide ranges in geomorphological attributes, hydro-climatic conditions, and socio-economic status. Furthermore, we identify the relation of the findings with multiple factors related to human activities, such as the spatial distribution of human settlements, the degree of economy development, and the fraction of communities served by WWTPs. Generalizable patterns found in this study are expected to contribute to establishing viable management plans for recent water-environmental challenges caused by WWTP-discharges to river water bodies.

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Quantification of Turbulence Characteristics on the Concentration Distributions of Traffic-related Pollutants Near Roadways (도로변 난류특성과 교통량에 따른 차량유발 난류강도 정량화: 도로변 풍상/풍하 측에서의 3차원 풍속 동시 측정에 기반)

  • Yongmi Park;Subin Han;HanGyeol Song;Seung-Bok Lee;Kyung-Hwan Kwak;Changhyuk Kim;Wonsik Choi
    • Atmosphere
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    • v.33 no.4
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    • pp.343-354
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    • 2023
  • Turbulence produced on roadways is one of the major factors determining the dilution rates at the initial stage of traffic emissions of air pollutants and, thus, the distribution of air pollutants near the roadways. Field experiments were conducted on Gyeongbu Highway, one of the busiest highways in Korea, for 4~7 days in winter, spring, and summer. Two three-dimensional ultrasonic anemometers were installed on both sides of the highway to estimate turbulence intensities (vertical wind fluctuation and kinetic turbulence energy) induced by the roadway. Roadway-induced turbulence consists of three components: structural road-induced turbulence (S-RIT), thermal road-induced turbulence (T-RIT), and vehicle-induced turbulence (VIT). The contribution of T-RIT to the total RIT was insignificant (less than 10%), and the majority of RIT was S-RIT (by the highway embankment) and VIT. In this study, we propose the empirical relationships of VIT as a function of traffic density and wind speed under free-flow traffic conditions. Although this empirical relationship appears to underestimate the VIT, it can be applied to the air quality models easily because the relationship is simple and only needs readily obtainable input variables (wind speed and traffic information).

Hydraulic and hydrologic performance evaluation of low impact development technology

  • Yano, Kimberly Ann;Geronimo, Franz Kevin;Reyes, Nash Jett;Choe, Hye-Seon;Jeon, Min-Su;Kim, Lee-Hyeong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.325-325
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    • 2020
  • Low impact development (LID) is a widely used technology that aims to reduce the peak flow volume and amount of pollutants in stormwater runoff while introducing physicochemical, biological or a combination of both mechanisms in order to improve water quality. This research aimed to determine the effect of hydrologic factors in removing the pollutants on stormwater runoff by an LID facility. Monitored storm events from 2010-2018 were analysed to evaluate the hydraulic and hydrological performance of a small constructed wetland (SCW). Standard methods for the examination water and wastewater were employed to assess the water quality of the collected samples (APHA et al, 1992). Primary hydrologic data were obtained from the Korea Meteorological Administration. The recorded average rainfall intensity and antecedent dry days (ADD) of SCW were 5.26 mm/hr and 7 days respectively. During the highest rainfall event (27 mm/hr), the removal efficiency of SCW for all the pollutants was ranging from 67% to 91%. While on the lowest rainfall event (0.7 mm/hr), the removal efficiency was ranging from -36% to 62%. Rainfall intensity has a significant effect to the removal efficiencies of each facility due to its dilution factor. In addition to that, there was no significant correlation of ADD to the mean concentrations of pollutants. Generally, stormwater runoff contains significant amount of pollutants that can cause harmful effects to the environment if not treated. Also, the component of this LID facility such as pre-treatment zone, media filters and vegetation contributed to the effectivity of the LID facilities in reducing the amounts of pollutants present in stormwater runof.

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Limited in vitro differentiation of porcine induced pluripotent stem cells into endothelial cells

  • In-Won Lee;Hyeon-Geun Lee;Dae-Ky Moon;Yeon-Ji Lee;Bo-Gyeong Seo;Sang-Ki Baek;Tae-Suk Kim;Cheol Hwangbo;Joon-Hee Lee
    • Journal of Animal Reproduction and Biotechnology
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    • v.38 no.3
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    • pp.109-120
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    • 2023
  • Background: Pluripotent stem cells (PSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) offer the immense therapeutic potential in stem cell-based therapy of degenerative disorders. However, clinical trials of human ESCs cause heavy ethical concerns. With the derivation of iPSCs established by reprogramming from adult somatic cells through the transgenic expression of transcription factors, this problems would be able to overcome. In the present study, we tried to differentiate porcine iPSCs (piPSCs) into endothelial cells (ECs) for stem cell-based therapy of vascular diseases. Methods: piPSCs (OSKMNL) were induced to differentiation into ECs in four differentiation media (APEL-2, APEL-2 + 50 ng/mL of VEGF, EBM-2, EBM-2 + 50 ng/mL of VEGF) on cultured plates coated with matrigel® (1:40 dilution with DMEM/F-12 medium) for 8 days. Differentiation efficiency of these cells were exanimated using qRT-PCR, Immunocytochemistry, Western blotting and FACS. Results: As results, expressions of pluripotency-associated markers (OCT-3/4, SOX2 and NANOG) were higher observed in all porcine differentiated cells derived from piPSCs (OSKMNL) cultured in four differentiation media than piPSCs as the control, whereas endothelial-associated marker (CD-31) in the differentiated cells was not expressed. Conclusions: It can be seen that piPSCs (OSKMNL) were not suitable to differentiate into ECs in the four differentiation media unlike porcine epiblast stem cells (pEpiSCs). Therefore, it would be required to establish a suitable PSCs for differentiating into ECs for the treatment of cardiovascular diseases.

Retrieval and Validation of Precipitable Water Vapor using GPS Datasets of Mobile Observation Vehicle on the Eastern Coast of Korea

  • Kim, Yoo-Jun;Kim, Seon-Jeong;Kim, Geon-Tae;Choi, Byoung-Choel;Shim, Jae-Kwan;Kim, Byung-Gon
    • Korean Journal of Remote Sensing
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    • v.32 no.4
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    • pp.365-382
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    • 2016
  • The results from the Global Positioning System (GPS) measurements of the Mobile Observation Vehicle (MOVE) on the eastern coast of Korea have been compared with REFerence (REF) values from the fixed GPS sites to assess the performance of Precipitable Water Vapor (PWV) retrievals in a kinematic environment. MOVE-PWV retrievals had comparatively similar trends and fairly good agreements with REF-PWV with a Root-Mean-Square Error (RMSE) of 7.4 mm and $R^2$ of 0.61, indicating statistical significance with a p-value of 0.01. PWV retrievals from the June cases showed better agreement than those of the other month cases, with a mean bias of 2.1 mm and RMSE of 3.8 mm. We further investigated the relationships of the determinant factors of GPS signals with the PWV retrievals for detailed error analysis. As a result, both MultiPath (MP) errors of L1 and L2 pseudo-range had the best indices for the June cases, 0.75-0.99 m. We also found that both Position Dilution Of Precision (PDOP) and Signal to Noise Ratio (SNR) values in the June cases were better than those in other cases. That is, the analytical results of the key factors such as MP errors, PDOP, and SNR that can affect GPS signals should be considered for obtaining more stable performance. The data of MOVE can be used to provide water vapor information with high spatial and temporal resolutions in the case of dramatic changes of severe weather such as those frequently occurring in the Korean Peninsula.

Pesticide residues in chili pepper seeds and their transfer into the seed oil (고추씨 중 농약 잔류와 고추씨 기름으로 농약의 이행)

  • Lee, Mi-Gyung;Kim, Jong Seong
    • Korean Journal of Food Science and Technology
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    • v.48 no.4
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    • pp.317-322
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    • 2016
  • A pesticide mix solution containing difenoconazole, lambda-cyhalothrin, and lufenuron was applied 3 times on field grown chili pepper at a fivefold overdose dilution concentration of the spray solution at a pre-harvest interval of 7 day. Difenoconazole, lambda-cyhalothrin, and lufenuron were detected at 4.43, 0.334, and 1.56 mg/kg, respectively, in raw chili pepper. Washing with water reduced the residue levels to 91.4, 94.3, and 85.3%, respectively. In dried chili pepper, the residues of difenoconazole, lambda-cyhalothrin, and lufenuron were 22.2 mg/kg (processing factor, Pf =5.01), 1.65 mg/kg (Pf =4.94), and 6.54 mg/kg (Pf =4.19). In the seeds, difenoconazole and lambda-cyhalothrin were not detected, and lufenuron was detected at 0.0075 mg/kg (n=1) and <0.005 mg/kg (n=2). Thus the pesticide residues in the seeds was negligible. In the seed oil, difenoconazole and lufenuron residues were 0.0263 and 0.0295 mg/kg, respectively (concentration factors=5.26 and 4.72). These concentration factors supported the theoretical concentration factor of 6.8, assuming that all of compound present in the seed are transferred into the oil.

Factors Affecting the Minimum Detectable Activity of Radioactive Noble Gases (방사성 노블가스 측정을 위한 최소검출방사능 산출의 조절인자)

  • Park, Ji-young;Ko, Young Gun;Kim, Hyuncheol;Lim, Jong-Myoung;Lee, Wanno
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.3
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    • pp.301-308
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    • 2018
  • Anthropogenic radioactive noble gases formed by nuclear fission are significant indicators used to monitor the nuclear activity of neighboring countries. In particular, radioactive xenon, owing to its abundant generation and short half-life, can be used to detect nuclear testing, and radioactive krypton has been used as a tracer to monitor the reprocessing of nuclear fuels. Released radioactive noble gases are in the atmosphere at infinitesimal amounts due to their dilution in the air and their short half-life decay. Therefore, to obtain reliable and significant data when performing measurement of noble gases in the atmosphere, the minimum detectable activity (MDA) for noble gases should be defined as low as possible. In this study, the MDA values for radioactive xenon and krypton were theoretically obtained based on the BfS-IAR system by collecting both noble gases simultaneously. In addition, various MDA methods, confidence level and analysis conditions were suggested to reduce and optimize MDA with an assessment of the factors affecting MDA. The current investigation indicated that maximizing the pretreatment efficiency and performance maintenance of the counter were the most important aspects for Xe. In the case of Kr, since sample activities are much higher than those of Xe, it is possible to change the target MDA or to simplification of the analysis system.

Uncertainty evaluation for the determination of creatinine in urine by LC-MS/MS (LC-MS/MS를 이용한 소변 중 크레아티닌 분석의 측정불확도 평가)

  • Kim, Jin-Young;Kwon, Woon-Yong;Suh, Sung-Ill;In, Moon-Kyo
    • Analytical Science and Technology
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    • v.25 no.1
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    • pp.83-90
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    • 2012
  • The objective of the study was to estimate the measurement uncertainty associated with determination of creatinine (Cr) in urine samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Centrifuged urine samples (10 ${\mu}L$) were diluted with 390 ${\mu}L$ of distilled water. To 20 ${\mu}L$ aliquots of diluted urine samples, 30 ${\mu}L$ of internal standard solution (Cr-$d_3$, 5 ${\mu}g/mL$) and 10 ${\mu}L$ of acetonitrile were added and filtered. The samples (1 ${\mu}L$) were introduced into LC-MS/MS with no further pretreatment. Cr was separated on a multi-mode ODS column (Scherzo SM-C18, 75 ${\times}$ 2.0 mm I.D., 3 ${\mu}m$) and quantified by LC-MS/MS operating in MRM mode (Cr, m/z 114.0${\rightarrow}$ 86.0; Cr-$d_3$, m/z 117.0${\rightarrow}$ 89.1). The four factors that contribute uncertainty to the final result were extracted and evaluated. The principal factors of contribution to combined standard uncertainty were sample dilution, calibration curve and repeatability, while the preparation of standard solution was only a minor factor. Relative extended uncertainty of the measured concentration was 14.2% in a real urine sample.

Source Proximity and Meteorological Effects on Residential Ambient Concentrations of PM2.5, Organic Carbon, Elemental Carbon, and p-PAHs in Houston and Los Angeles, USA

  • Kwon, Jaymin;Weisel, Clifford P.;Morandi, Maria T.;Stock, Thomas H.;Turpin, Barbara
    • Journal of Environmental Science International
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    • v.25 no.10
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    • pp.1349-1368
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    • 2016
  • Concentrations of fine particulate matter ($PM_{2.5}$) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. $PM_{2.5}$ mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the $PM_{2.5}$ constituents' regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven $PM_{2.5}$ constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the $PM_{2.5}$ constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to $PM_{2.5}$ mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.