• Title/Summary/Keyword: Complex exposure

Search Result 455, Processing Time 0.035 seconds

A Case of Hot Tub Lung (온수욕조 폐 1예)

  • Kim, Min;Cha, Seung-Ick;Shin, Kyung-Min;Yoon, Ghil-Suk;Bae, Jung-Hyun;Yoon, Won-Kyung;Lee, Shin-Yup;Kim, Chang-Ho;Park, Jae-Yong;Jung, Tae-Hoon
    • Tuberculosis and Respiratory Diseases
    • /
    • v.68 no.4
    • /
    • pp.236-239
    • /
    • 2010
  • Hot tub lung is a lung disorder associated with exposure to hot tub water contaminated with Mycobacterium avium complex (MAC). Although its pathogenesis remains unclear, it may be considered hypersensitivity pneumonitis (HP) rather than an infectious disease. We report a case which fulfilled the current diagnostic criteria of hot tub lung. A patient had worked as a cleaner in the public bath for approximately one year and presented with dyspnea for over one month. The computed tomographic finding of bilateral ground glass attenuation and pathologic finding of granulomatous inflammation were consistent with HP. MAC was isolated from bronchoalveolar lavage fluid and hot tub water. After corticosteroid treatment without antimycobacterial medication, the patient improved and there has been no recurrence. The patient has since discontinued working in the public bath.

Clinical Characteristics of Odontoma in Children : A Retrospective Analysis of 105 Cases (유년기 치아종의 임상적 특징 : 105증례의 후향적 분석)

  • Kim, Hyo-jin;Kim, So-hyun;Kim, Hyun-jung;Kim, Young-jin;Nam, Soon-hyeun
    • The Journal of the Korean dental association
    • /
    • v.53 no.12
    • /
    • pp.949-957
    • /
    • 2015
  • We investigate the clinical characteristics of odontoma in childhood and adolescence. A retrospective analysis was performed in 105 patients under 15 years old who were diagnosed with odontoma in Kyungpook National University Dental Hospital, the department of pediatric dentistry between 1 January 2008 and 31 December 2013. The ratio of compound odontoma, immature odontoma and complex odontoma were 67.6%, 21.9% and 10.5%, respectively. Odontoma was more prevalent in males and the ratio of males to females was 1.5:1. The age of patients ranged from 3 to 14 years old with an average age of 9.3 years old. The odontoma was more frequently located in the maxilla (73.3%) than in the mandible(26.7%). In 98 cases, it was treated by surgical removal. Among adjacent teeth impacted by odontoma, 26 cases (34.7%) of successional permanent teeth were erupted when only odontoma were removed and 6 cases (8.0%) were erupted when surgical exposure was performed. Orthodontic tractions were performed in 43 cases (57.3%). In conclusion, odontoma could cause complications such as impaction of teeth. If they are found early and treated properly, high eruption success of successional permanent teeth can be obtained. The occurrence frequency of immature odontoma are higher than that of complex odontoma, and they are observed intensively in anterior maxillary teeth. Therefore, it is considered that they are important causes of dental impaction in anterior maxillary teeth.

A Case Study on Health Impact Assessment of Hazardous Air Pollutants in Industrial Complex Development Plan (산업단지 계획 시 유해대기오염물질에 대한 건강영향평가 사례 연구)

  • Kim, Sang-Mok;Son, Eun-Seong;Seo, Young-Kyo;Baek, Sung-Ok
    • Journal of Environmental Impact Assessment
    • /
    • v.28 no.6
    • /
    • pp.616-625
    • /
    • 2019
  • Health impact assessment is implemented within the Environmental impact assessment for the purpose of minimizing health damage by predicting the impact on human health following implementation of the development project. In health impact assessment, manual revision is required due to the lack of consistency in the method of estimating hazardous air pollutants emissions. This study estimated the emissions by calculating the emissions of hazardous air pollutants based on the actual industrial complex development cases and completed health impact assessments. As a result of risk assessment based on exposure concentration using CALPUFF model, the risk assessment results were different for each of the emission estimation methods, and manual improvement on the emission estimation method is needed.

The Study on Location and Adsorbate Interaction for Vanadium Species in $VO^{2+}-SAPO-5$ by Electron Spin Resonance and Electron Spin Echo Modulation Spectroscopies

  • Back Gern-Ho;Park Sung-Gun;Lee Chul-Wee
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.9 no.2
    • /
    • pp.138-154
    • /
    • 2005
  • Vanadium-incorporated aluminophosphate molecular sieve $VO^{2+}-SAPO-5$ was studied by electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies to determine the vanadium structure and interaction with various adsorbate molecules. It was found that the main species at low concentration of vanadium is a monomeric vanadium units in square pyramidal or distorted octahedral coordination, both in oxidation state (IV) for the calcined hydrated material and in oxidation state (V) for the calcined material. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. It is suggested as a $VO(H_2O)_3^{2+}$ complex coordinated to two framework oxygen bonded aluminum. When calcined, hydrated $VO^{2+}-}SAPO-5$ is dehydrated at elevated temperature, a species loses its water ligands and transforms to $VO^{2+}$ ions coordinated to two framework oxygens (species B). Species B reduces its intensity, significantly after treatment with $O_2\;at\;600^{\circ}C$ for 5 h, thus suggesting oxidation of $V^{4+}\;to\;V^{5+}$. When dehydrated $VO^{2+}-SAPO-5$ contacts with $D_2O$ at room temperature, the EPR signal of species A is observed. Thus species assumed as a $VO^{2+}(O_f)_2(D_2O)_3$, by considering two framework oxygens. Adsorption of deuterated ethanol, propanol on dehydrated $VO^{2+}_{-}SAPO-5$ result in another new vanadium species E and F, respectively, which are identified as a $VO^{2+}-(CH_3CH_2OD)_3,\;VO^{2+}-(CH_3CH_2CH_2OD)_2$ complex. When deuterated benzene is adsorbed on dehydrated $VO^{2+}-SAPO-5$, another new vanadium species G, identified as a $VO^{2+}-(C_6D_6)$ is observed. Possible coordination geometries of these various complexes are discussed.

  • PDF

The Crystal Structure of a Sulfur Sorption Complex of the Dehydrated Partially $Co^{2+}$-Exchanged Zeolite A

  • 염영훈;송성환;김양
    • Bulletin of the Korean Chemical Society
    • /
    • v.16 no.9
    • /
    • pp.823-826
    • /
    • 1995
  • The crystal structure of a sulfur sorption complex of the dehydrated partially Co2+ exchanged zeolite A (a=12.058(2) Å) has been determined by single-crystal X-ray techniques. The crystal structure was solved and refined in cubic space group Pm3m at 21(1) ℃. Ion Exchange with aqueous 0.05 M Co(NO3)2 was done by the static method. The crystal of Na4Co4-A was dehydrated at 380 ℃ and 2 × 10-6 Torr for 2 days, followed by exposure to about 100 Torr of sulfur at 330 ℃ for 72 h. Full matrix least-squares refinement converged to R1=0.084 and Rw=0.074 with 102 reflections for which I > 3σ(I). Crystallographic analysis shows that 2.8 Co2+ ions and 4 Na+ ions per unit cell occupy 6-ring sites on the threefold axes. 1.2 Co2+ ions occupy the 8-ring sites on fourfold axes. 2.8 Co2+ ions at Co(1) are recessed 0.66 Å into the large cavity and 4 Na+ ion at Na(1) are recessed 0.77 Å into the sodalite cavity from the (111) plane of O(3)'s. Approximately 16 sulfur atoms were sorbed per unit cell. Two S8 rings, each in a butterfly form, are found in the large cavity. The bond length between S and its adjacent S is 2.27(3) Å. The distance between 6-ring Co2+ ion and its adjacent sulfur is 2.53 (2) Å and that between 8-ring Co2+ ions and its adjacent sulfur is 2.72(9) Å. The angles of S-S'-S and S'-S-S'/ in octasulfur rings are 119.0(2)°and 113.0(2)°, respectively.

The Crystal Structure of Dehydrated Fully $Ag^+$-Exchanged Zeolite A Successively Treated with Ethylene and Bromine Vapor

  • Jeong, Mi-Suk;Jang, Se-Bok;Kim, Yang
    • Bulletin of the Korean Chemical Society
    • /
    • v.15 no.11
    • /
    • pp.940-944
    • /
    • 1994
  • The crystal structure of an ethylene sorption complex of dehydrated $Ag_{12}-A $reacted with bromine vapor has determined by single-crystal X-ray diffraction techniques in the cubic space group of Pm3m at 22(l)$^{\circ}$C (a=12.180(2) ${\AA}$). The crystal was prepared by dehydration of $Ag_{12}$-A at 400 $^{\circ}$C and $2 {\times} l0^{-6}$ Torr for 2 days, followed by exposure to 200 Torr of ethylene gas at 24(l) $^{\circ}$C for 1 hr. After the ethylene gas was evacuated for 1 hr, the crystal was exposed to 180 Torr of bromine vapor at 24(l) $^{\circ}$C for 1.5 h. The structure was refined to the final error indices, $R_1=0.066\;and\;R_2$ (weighted)=0.055, using 137 independent reflections for which I>3${\sigma}$I. About 55% of the sodalite unit contain two 6-ring $Ag^+$ ions and the remaining 45% contain $Ag_6$ molecules complexed to 2 $Ag^+$ ions at 6-ring sites to give $(Ag^+)_2(Ag_6).$ Upon sorption of ethylene, 4.75 ethylene molecules were sorbed per unit cell and of these, only 1.25 ethylene molecules were brominated by treatment of dibromine because of the limitation of the available space for the reaction products in the large cavity. In the large cavity, each of 3.5 $Ag^+$ ions forms a lateral ${\pi}$ complex with an ethylene molecule. About 2.5 8-ring $Ag^+$ ions per unit cell interact with 1.25 1,2-dibromoethane and each of ca. 1.25 6-ring $Ag^+$ ions also interacts with one of bromine atoms of 1,2-dibromoethane. Each bromine atom approaches a carbon atom with C-Br(l)=2.07(20) ${\AA}$ and C-Br(2)=2.07(10) ${\AA}$, respectively.

Crystal Structure of a Benzene Sorption Complex of Dehydrated Fully $Cd^{2+}$-Exchanged Zeolite X

  • 김양;염영훈;최은영;김안나;한영욱
    • Bulletin of the Korean Chemical Society
    • /
    • v.19 no.11
    • /
    • pp.1222-1227
    • /
    • 1998
  • The crystal structure of a benzene sorption complex of fully dehydrated Cd2+-exchanged zeolite X, Cd46Si100Al92O384·43C6H6 (a=24.880(6) Å), has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21 ℃. The crystal was prepared by ion exchange in a flowing stream of 0.05 M aqueous Cd(NO3)2 for 3 d, followed by dehydration at 400 ℃ and 2 x 10-6 Torr for 2 d, followed by exposure to about 92 Torr of benzene vapor at 22 ℃. The structure was determined in this atmosphere and refined to the final error indices R1=0.054 and Rw=0.066 with 561 reflections for which I > 3σ(I). In this structure, Cd2+ ions are found at four crystallographic sites: eleven Cd2+ ions are at site 1, at the centers of the double six-oxygen rings; six Cd2+ ions lie at site I', in the sodalite cavity opposite to the double six-oxygen rings; and the remaining 29 Cd2+ ions are found at two nonequivalent threefold axes of unit cell, sites Ⅱ' (in the sodalite cavity ) and site Ⅱ (in the supercage) with occupancies of 2 and 27 ions, respectively. Each of these Cd2+ ions coordinates to three framework oxylkens, either at 2.173(13) or 2.224(10) Å, respectively, and extends 0.37 Å into the sodalite unit or 0.60 Å into the supercage from the plane of the three oxygens to which it is bound. The benzene molecules are found at two distinct sites within the supercages. Twenty-seven benzenes lie on threefold axes in the large cavities where they interact facially with the latter 27 site-Ⅱ Cd2+ ions (Cd2+-benzene center=2.72 Å; occupancy=27 molecules/32 sites). The remaining sixteen benzene molecules are found in 12ring planes; occupancy=16 molecules/16 sites. Each hydrogen of these sixteen benzenes is ca. 2.8/3.0 Å from three 12-ring oxygens where each is stabilized by multiple weak electrostatic and van der Waals interactions with framework oxygens.

Microsurgical reconstruction of posttraumatic large soft tissue defects on face (광범위한 안면외상 환자에서의 미세술기를 이용한 재건술)

  • Baek, Wooyeol;Song, Seung Yong;Roh, Tai Suk;Lee, Won Jai
    • Journal of the Korean Medical Association
    • /
    • v.61 no.12
    • /
    • pp.724-731
    • /
    • 2018
  • Our faces can express a remarkable range of subtle emotions and silent messages. Because the face is so essential for complex social interactions that are part of our everyday lives, aesthetic repair and restoration of function are an important tasks that we must not take lightly. Soft-tissue defects occur in trauma patients and require thorough evaluation, planning, and surgical treatment to achieve optimal functional and aesthetic outcomes, while minimizing the risk of complications. Recognizing the full nature of the injury and developing a logical treatment plan help determine whether there will be future aesthetic or functional deformities. Proper classification of the wound enables appropriate treatment, and helps predict the postoperative appearance and function. Comprehensive care of trauma patients requires a diverse breadth of skills, beginning with an initial evaluation, followed by resuscitation. Traditionally, facial defects have been managed with closure or grafting, and prosthetic obturators. Sometimes, however, large defects cannot be closed using simple methods. Such cases, which involve exposure of critical structures, bone, joint spaces, and neurovascular structures, requires more complex treatment. We reviewed and classified causes of significant trauma resulting in facial injuries that were reconstructed by microsurgical techniques without simple sutures or coverage with partial flaps. A local flap is a good choice for reconstruction, but large defects are hard to cover with a local flap alone. Early microsurgical reconstruction of a large facial defect is an excellent choice for aesthetic and functional outcomes.

Natural radioactivity level in fly ash samples and radiological hazard at the landfill area of the coal-fired power plant complex, Vietnam

  • Loan, Truong Thi Hong;Ba, Vu Ngoc;Thien, Bui Ngoc
    • Nuclear Engineering and Technology
    • /
    • v.54 no.4
    • /
    • pp.1431-1438
    • /
    • 2022
  • In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of 238U, 226Ra, 232Th and 40K were 93, 77, 92 and 938 Bq kg-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10-3, 4.26×10-3, 0.62×10-3, and 25.61×10-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

Effect of 42 amino acid long amyloid-β peptides on Arabidopsis plants

  • Lee, HanGyeol;Kim, Ji Woo;Jeong, Sangyun;An, Jungeun;Kim, Young-Cheon;Ryu, Hojin;Lee, Jeong Hwan
    • Journal of Plant Biotechnology
    • /
    • v.47 no.4
    • /
    • pp.283-288
    • /
    • 2020
  • Although the evolution of Arabidopsis thaliana and humans diverged approximately 1.6 billion years ago, recent studies have demonstrated that protein function and cellular processes involved in disease response remain remarkably conserved. Particularly, γ-secretase, a multisubunit protein complex that participates in intramembrane proteolysis (RIP) regulation, is also known to mediate the cleavage of more than 80 substrates including the amyloid precursor protein (APP) and the Notch receptor. Although the genes (PS1/2, APH-1, PEN-2, and NCT) coding for the γ-secretase complex components are present in plant genomes, their function remains largely uncharacterized. Given that the deposition of 42 amino acid long amyloid-β peptides (hAβ42) is thought to be one of the main causes of Alzheimer's disease, we aimed to examine the physiological effects of hAβ42 peptides on plants. Interestingly, we found that Arabidopsis protoplast death increased after 24 h of exposure to 3 or 5 µM hAβ42 peptides. Furthermore, transgenic Arabidopsis plants overexpressing the hAβ42 gene exhibited changes in primary root length and silique phyllotaxy. Taken together, our results demonstrate that hAβ42 peptides, a metazoan protein, significantly affect Arabidopsis protoplast viability and plant morphology.