• Title/Summary/Keyword: Deposition risk

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Effects of atmospheric environmental changes on annual ring growth of Cryptomeria japonica in Southern Korea

  • Luong, Thi-Hoan;Jang, Kyoung-Soo;Choi, Woo-Jung;Lee, Kye-Han
    • Journal of Ecology and Environment
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    • v.36 no.1
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    • pp.31-38
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    • 2013
  • Annual ring formation is considered a source of information to investigate the effects of environmental changes caused by temperature, air pollution, and acid rain on tree growth. A comparative investigation of annual ring growth of Cryptomeria japonica in relation to environmental changes was conducted at two sites in southern Korea (Haenam and Jangseong). Three wood disks from each site were collected from stems at breast height and annual ring growth was analyzed. Annual ring area at two sites increased over time (p > 0.05). Tree ring growth rate in Jangseong was higher than that in Haenam. Annual ring area increment in Jangseong was more strongly correlated with environmental variables than that in Haenam; annual ring growth increased with increasing temperature (p < 0.01) and a positive effect of $NO_2$ concentration on annual ring area (p < 0.05) could be attributed to nitrogen deposition in Jangseong. The correlation of annual ring growth increased with decreasing $SO_2$ and $CO_2$ concentrations (p < 0.01) in Jangseong. Variation in annual growth rings in Jangseong could be associated with temperature changes and N deposition. In Haenam, annual ring growth was correlated with $SO_2$ concentration (p < 0.01), and there was a negative relationship between precipitation pH and annual ring area (p < 0.01) which may reflect changes in nutrient cycles due to the acid rain. Therefore, the combined effects of increased $CO_2$, N deposition, and temperature on tree ring growth in Jangseong may be linked to soil acidification in this forest ecosystem. The interactions between air pollution ($SO_2$) and precipitation pH in Haenam may affect tree growth and may change nutrient cycles in this site. These results suggested that annual tree ring growth in Jangseong was more correlated with environmental variables than that in Haenam. However, the further growth of C. japonica forest at two sites is at risk from the long-term effects of acid deposition from fossil fuel combustion.

Role of Ischemic Preconditioning in the Cardioprotective Mechanisms of Monomeric C-Reactive Protein-Deposited Myocardium in a Rat Model

  • Kim, Eun Na;Choi, Jae-Sung;Kim, Chong Jai;Kim, So Ra;Oh, Se Jin
    • Journal of Chest Surgery
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    • v.54 no.1
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    • pp.9-16
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    • 2021
  • Background: The deposition of monomeric C-reactive protein (mCRP) in the myocardium aggravates ischemia-reperfusion injury (IRI) and myocardial infarction. Ischemic preconditioning (IPC) is known to protect the myocardium against IRI. Methods: We evaluated the effects of IPC on myocardium upon which mCRP had been deposited due to IRI in a rat model. Myocardial IRI was induced via ligation of the coronary artery. Direct IPC was applied prior to IRI using multiple short direct occlusions of the coronary artery. CRP was infused intravenously after IRI. The study included sham (n=3), IRI-only (n=5), IRI+CRP (n=9), and IPC+IRI+CRP (n=6) groups. The infarcted area and the area at risk were assessed using Evans blue and 2,3,5-triphenyltetrazolium staining. Additionally, mCRP immunostaining and interleukin-6 (IL-6) mRNA reverse transcription-polymerase chain reaction were performed. Results: In the IRI+CRP group, the infarcted area and the area of mCRP deposition were greater, and the level of IL-6 mRNA expression was higher, than in the IRI-only group. However, in the IPC+IRI+CRP group relative to the IRI+CRP group, the relative areas of infarction (20% vs. 34%, respectively; p=0.079) and mCRP myocardial deposition (21% vs. 44%, respectively; p=0.026) were lower and IL-6 mRNA expression was higher (fold change: 407 vs. 326, respectively; p=0.376), although the difference in IL-6 mRNA expression was not statistically significant. Conclusion: IPC was associated with significantly decreased deposition of mCRP and with increased expression of IL-6 in myocardium damaged by IRI. The net cardioprotective effect of decreased mCRP deposition and increased IL-6 levels should be clarified in a further study.

Spray and Atomization Technologies in Pesticides Application: A Review

  • No, Soo-Young
    • Journal of ILASS-Korea
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    • v.6 no.4
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    • pp.1-13
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    • 2001
  • In the pesticides sprays, spray and atomization technologies to increase the deposition and reduce the drift are briefly reviewed. Further research is needed to deduce a measure of drift risk in sprays with different structures, velocity profiles. For flat fan nozzles, the data of breakup length and thickness of liquid sheet are essential to understand the atomization processes and develop the transport model to target. In the air-assisted spray technology to reduce drift, further works on the effect of application height on drift and air assistance on droplet size should be followed. In addition, methods for quantifying included air in the air inclusion techniques are required. A few researches on the droplet size of fallout can be found in the literature. A combined technology with electrostatic method into one of method for the reduction of drift may be an effective strategy for increasing deposition and reducing drift.

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The Concepts of Nanotoxicology and Risk Assessment of the Nanoparticles (나노 독성의 개념 및 나노입자에 대한 위해성 평가의 필요성)

  • Maeng, Seung-Hee;Yu, Il-Je
    • Toxicological Research
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    • v.21 no.2
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    • pp.87-98
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    • 2005
  • Human exposure to nano-sized particles (NSP) has increased over the last century with anthropogenic sources, and the rapid development of nanotechnology becomes an another source of such exposure. Information regarding the safety of nanotechnology and its product, nanoparticles, is urgently needed when assuming exposure through inhalation, oral intake, and penetration across skin is ever increasing as growing nanotechnology rapidly. The recent advancement of biokinetic studies with NSP and newer epidemiologic and toxicologic studies with ultrafine particles can be the basis for the nanotoxicology. Some concepts of nanotoxicology can be known from the results of these results. Specific small size of NSP, when inhaled, facilitates deposition by difusional mechanism in all regions of the respiratory tract and uptake into cells, ranscytosis across epithelial and endothelial cells into the blood and lymph circulation to reach target sites. Translocation along axons and dendrites of neuron makes an access to CNS and ganglia. These biokinetics are dependent on NSP surface chemistry. Risk assessments of NSP include appropriate and relevant doses/concentration selections, the increase effects in the organism and the benefits of possible desirable effects. An interdisciplinary team approach is desirable for nanotoxicology research and an appropriate risk assessment.

Consequences of being born small for gestational age : More than being small (부당경량아. 크기만 작은가?)

  • Yoo, Eun-Gyong
    • Clinical and Experimental Pediatrics
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    • v.52 no.2
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    • pp.152-158
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    • 2009
  • Reduced fetal growth is independently associated with increased risk of health problems in later life, particularly type 2 diabetes and cardiovascular diseases. Insulin resistance appears to be a key component underlying these metabolic complications. It is suggested that detrimental fetal environment may program insulin resistance syndrome. An insulin-resistant genotype may also result in both low birth weight and insulin resistance syndrome, and it is likely that the association of low birth weight with insulin resistance is the result of both genetic and environmental factors. Early postnatal rapid catch-up growth is closely related to risk for subsequent metabolic diseases. Fat mass is strikingly reduced in neonates born small for gestational age (SGA), and recent data suggest that insulin resistance seen in catch-up growth is related to the disproportionate catch-up in fat mass compared with lean mass. Endocrine disturbances are also recognized in SGA children, but overt clinical problems are infrequent in childhood. Cognitive impairment is reported in some children born SGA, especially those who do not show catch-up growth, in whom early neurodevelopmental evaluation is required. Breast feeding, also known to be protective against the long-term risk of obesity, may prevent some intellectual impairment in SGA children. Calorie-dense feeding does not seem to be appropriate in SGA infants. We must balance the positive effect of nutrition on neural development against rapid fat deposition and the future risk of insulin resistance.

Clinical Implications of Focal Mineral Deposition in the Globus Pallidus on CT and Quantitative Susceptibility Mapping of MRI

  • Hyojin Kim;Jinhee Jang;Junghwa Kang;Seungun Jang;Yoonho Nam;Yangsean Choi;Na-young Shin;Kook-Jin Ahn;Bum-soo Kim
    • Korean Journal of Radiology
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    • v.23 no.7
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    • pp.742-751
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    • 2022
  • Objective: To assess focal mineral deposition in the globus pallidus (GP) by CT and quantitative susceptibility mapping (QSM) of MRI scans and evaluate its clinical significance, particularly cerebrovascular degeneration. Materials and Methods: This study included 105 patients (66.1 ± 13.7 years; 40 male and 65 female) who underwent both CT and MRI with available QSM data between January 2017 and December 2019. The presence of focal mineral deposition in the GP on QSM (GPQSM) and CT (GPCT) was assessed visually using a three-point scale. Cerebrovascular risk factors and small vessel disease (SVD) imaging markers were also assessed. The clinical and radiological findings were compared between the different grades of GPQSM and GPCT. The relationship between GP grades and cerebrovascular risk factors and SVD imaging markers was assessed using univariable and multivariable linear regression analyses. Results: GPCT and GPQSM were significantly associated (p < 0.001) but were not identical. Higher GPCT and GPQSM grades showed smaller gray matter (p = 0.030 and p = 0.025, respectively) and white matter (p = 0.013 and p = 0.019, respectively) volumes, as well as larger GP volumes (p < 0.001 for both). Among SVD markers, white matter hyperintensity was significantly associated with GPCT (p = 0.006) and brain atrophy was significantly associated with GPQSM (p = 0.032) in at univariable analysis. In multivariable analysis, the normalized volume of the GP was independently positively associated with GPCT (p < 0.001) and GPQSM (p = 0.002), while the normalized volume of the GM was independently negatively associated with GPCT (p = 0.040) and GPQSM (p = 0.035). Conclusion: Focal mineral deposition in the GP on CT and QSM might be a potential imaging marker of cerebral vascular degeneration. Both were associated with increased GP volume.

Addition Effect of the Deposition and Buoyancy Terms in Modeling Turbulence Diffusion of Hazardous Air Pollutants (유해 대기오염물질의 난류확산 수치모의에서 침적한과 부력항 추가에 따른 효과)

  • Won, Gyeong-Mee;Lee, Hwa-Woon;Ji, Hyo-Eun;Kim, Cheol-Hee;Song, Chang-Keun
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.1
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    • pp.73-84
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    • 2006
  • Hazardous Air Pollutants (HAPs) are characterized by being relatively heavier and denser than that of ambient air due to the various reasons such as higher molecular weight, low temperature and other complicated chemical transformations (Witlox, 1994). In an effort to investigate transport and diffusion from instantaneous emission of heavy gas, Lagrangian Particle Dispersion Model (LPDM) coupled with the RAMS output was employed. Both deposition process and buoyancy term were added on the atmospheric diffusion equations of LPDM, and the locations and concentrations of dense gas particle released from instantaneous single point source (emitting initially for 10 minutes only) were analyzed. The result overall shows that adding deposition process and buoyancy terms on the diffusion equation of LPDM has very small but detectable effect on the vertical and horizontal distribution of Lagrangian particles that especially transported for a fairly long traveling time. Also the slumping of dense gas can be found to be ignored horizontally compared to the advection by the horizontal wind suggesting that it was essential to couple the Lagrangian particle dispersion model coupled with the RAMS model in order to explain the dispersion of HAPs more accurately. However, during the initial time of instantaneous emission, buoyancy term play an important role on the vertical locations of dense particles for near surface atmosphere and around source area, indicating the importance of densities of HAPs in the beginning stage or short duration for the risk assessment of HAPs or management of heavy vapors during the explosive accidents.

Role of TGF-β1/SMADs signalling pathway in resveratrol-induced reduction of extracellular matrix deposition by dexamethasone-treated human trabecular meshwork cells

  • Amy Suzana Abu Bakar;Norhafiza Razali;Renu Agarwal;Igor Iezhitsa;Maxim A. Perfilev;Pavel M. Vassiliev
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.4
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    • pp.345-359
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    • 2024
  • Deposition of extracellular matrix (ECM) in the trabecular meshwork (TM) increases aqueous humour outflow resistance leading to elevation of intraocular pressure (IOP) in primary open-angle glaucoma, which remains the only modifiable risk factor. Resveratrol has been shown to counteract the steroid-induced increase in IOP and increase the TM expression of ECM proteolytic enzymes; however, its effects on the deposition of ECM components by TM and its associated pathways, such as TGF-β-SMAD signalling remain uncertain. This study, therefore, explored the effects of trans-resveratrol on the expression of ECM components, SMAD signalling molecules, plasminogen activator inhibitor-1 and tissue plasminogen activator in dexamethasone-treated human TM cells (HTMCs). We also studied the nature of molecular interaction of trans-resveratrol with SMAD4 domains using ensemble docking. Treatment of HTMCs with 12.5 µM trans-resveratrol downregulated the dexamethasone-induced increase in collagen, fibronectin and α-smooth muscle actin at gene and protein levels through downregulation of TGF-β1, SMAD4, and upregulation of SMAD7. Downregulation of TGF-β1 signalling by trans-resveratrol could be attributed to its effect on the transcriptional activity due to high affinity for the MH2 domain of SMAD4. These effects may contribute to resveratrol's IOP-lowering properties by reducing ECM deposition and enhancing aqueous humour outflow in the TM.

Development of a General Occupational Safety and Health (OSH) Guide for Maintenance in Etching, Deposition, and Ion Implantation Facilities (반도체 공정 설비 정비 작업 안전보건 가이드: 증착, 식각, 이온주입)

  • Kyung Ehi Zoh;Taek-hyeon Han;Jae-jin Moon;Ingyun Jung;Yeong Woo Hwang;Seyoung Kwon;Kyung-yoon Ko;Mingun Lee;Jaepil Chang;Dong-Uk Park
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.34 no.2
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    • pp.125-133
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    • 2024
  • Objectives: The aim of this study is to develop a comprehensive Occupational Safety and Health (OSH) guide for maintenance tasks in semiconductor processing, specifically focusing on etching, deposition, and ion implantation processes. Methods: The development of the OSH guide involved a literature review, consultations with industry experts, and field investigations. It concentrates on Maintenance Work (MW) operations in these specialized areas. Results: The result is a detailed OSH guide tailored to MW in etching, deposition, and ion implantation facilities within semiconductor processing. This guide is structured to assist maintenance workers through pre-, during and post-MW phases, ensuring easy comprehension and adherence to safety protocols. It highlights the necessity of safety and health measures throughout the MW process to protect personnel. The guide is enriched with real-life scenarios and visual aids, including cartoons and photographs, to aid in the understanding and implementation of safety and health principles. Conclusions: This OSH guide is designed to enhance the protection of workers engaged in maintenance activities in the electronics sector, particularly in semiconductor manufacturing. It aims to improve compliance with safety and health standards in these high-risk environments.

Familial Otosclerosis Associated with Osteogenesis Imperfecta: A Case Report

  • Lee, Ha Neul;Jeon, Hyun Jong;Seo, Young Joon
    • Journal of Audiology & Otology
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    • v.25 no.4
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    • pp.230-234
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    • 2021
  • Otosclerosis, a hereditary disorder characterized by disordered resorption and deposition of bone, results in progressive hearing loss. Osteogenesis imperfecta (OI) is a genetic disorder characterized by recurrent fractures, blue sclera, and varying degrees of hearing impairment; and is a known risk factor for otosclerosis. After adolescence, the risk of fracture decreases, reducing the need for follow-up in OI. However, otosclerosis is a progressive disorder. In this report, we discuss two cases of familial otosclerosis with different clinical features. We hypothesize that the difference in hearing level correlates with the difference in computed tomography findings. The mother, whose case was considered severe, was prescribed hearing aids, while the daughter, who had normal hearing level, was regularly followed up.