• Title/Summary/Keyword: Complex exposure

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Epidemiologic Studies of Reproductive Health in Male Workers (남성 근로자의 생식보건 역학연구)

  • Choi, Byeong Ju;Lee, Sanggil;Kim, Seonggyu;Sung, Jungmin;Ye, Shinhee
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.31 no.3
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    • pp.202-212
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    • 2021
  • Objectives: The reproductive health of female workers has been extensively investigated in South Korea and other countries worldwide. However, few studies have discussed the reproductive health of male workers. In this study, we reviewed the recent literature that reports on the effects of occupational exposure on the reproductive health of male workers and the health of their children. Methods: In May 2020 we used the PubMed search engine to search the literature over the last 10 years and chose case-control, cohort, and cross-sectional studies and reviews. We selected epidemiological studies that investigated the association between pre-pregnant occupational exposure and the reproductive health of male workers and the health of their children. We excluded case reports, non-epidemiological studies (animal experiments, cellular-level experiments, and similar articles), and studies that described postnatal occupational exposure. Results: We eventually selected 23 studies. The studies that included exclusively male workers reported that those employed in the agricultural sector or those exposed to pesticides showed lower blood levels of reproductive hormones and a high risk of lympho-hematopoietic system cancer in their children. Male workers exposed to complex organic solvents and organic compounds showed a high risk of poor semen quality, increased time to pregnancy, decreased blood levels of reproductive hormones, and a high risk of lympho-hematopoietic system cancer in their children. Male workers employed in occupations that involved significant social contact, or in the leather and livestock industries, and in occupations with high levels of exposure to lead and organic solvents showed a high risk of malignancies, including lympho-hematopoietic system cancer, neuroblastoma, and central nervous system tumors in their children. Studies that investigated both male and female workers reported that children of male smelters showed a high risk of premature birth, and children of male workers exposed to metals showed a high risk of hypospadias and cryptorchidism. Children of male welders and workers employed in the glass, ceramic, and tile industries showed a high risk of premature birth. Conclusion: The findings of this study will serve as basic data for further research on male workers' reproductive health and provide a scientific basis for the development of strategies to protect the reproductive health of males employed in high-risk occupations. Moreover, the results of this study may provide guidelines to improve the understanding of and knowledge on male workers' reproductive health.

The development of complex electrode for fuel cell using CNT (CNT를 이용한 PEMFC 연료전지용 복합전극 개발)

  • Ok, Jinhee;Altalsukh, Dorjgotov;Rhee, Junki;Park, Sangsun;Shul, Yonggun
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.135.2-135.2
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    • 2010
  • Carbon nanotube(CNT) has been spotlighted as a promising candidate for catalyst support material for PEMFC (proton exchange membrane fuel cell). The considerable properties of CNT include high surface area, outstanding thermal, electrical conductivity and mechanical stability. In this study, to fully utilize the properties of CNTs, we prepared directly oriented CNT on carbon paper as a catalyst support in the cathode electrode. The CNT layer was prepared by a chemical vapor deposition(CVD) process. And the Pt particles were deposited on the CNT oriented carbon paper by impregnation and eletro-deposition method. The potential advantages of directly oriented CNT on carbon paper can include improved thermal and charge transfer through direct contact between the electrolyte and the electrode and enhanced exposure of Pt catalyst sites during the reaction.

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Microbial Biosensors for Environmental and Food industrial Applications (환경오염과 식품공업 측정용 미생물 바이오센서)

  • 김의락
    • KSBB Journal
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    • v.17 no.3
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    • pp.213-227
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    • 2002
  • To date, the majority of biosensor technologies use binding components such as enzymes antibodies, nucleic acids and protein ligands. In contrast, the goal underlying the use of cells and tissues of animals and plants for a sensor system is to obtain systems capable of extracting information based on the biological activity, mechanisms of action and consequences of exposure to a chemical or biological agent of interest. These systems enable the interrogation of more complex biological response and offer the potential to gather higher information content from measuring physiologic and metabolic response. In these articles, same of the recent trends and applications of microbial biosensors in environmental monitoring and for use in food and fermentations have been reviewed. This endeavor presents many technological challenges to fabricate new microbial biosensors for other scientific field.

Effects of sunlight and predacious microorganisms on survival of enteric bacteria in sewage water (하수중 장내세균에 대한 태양광선 및 포식미생물의 살균효과)

  • 최경화;정혜경;김치경
    • Korean Journal of Microbiology
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    • v.20 no.1
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    • pp.21-26
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    • 1982
  • The disinfection effects of sunlight and predacious microorganisms on enteria of Escherichia coli and Proteus vulgaris were examined in sewage water at 22 to $26^{\circ}C$. The test prganisms were disinfected by 4 to 5 logs during 6-hour a day exposure to sunlight for seven days. The effect was proportional to the light intensity and was proved to be dur to the action of the visible light of short wavelength which can transmit the soft glass of a flask glass. The predacious microorganisms decreased trhe test organisms by about 3 to 4 logs during 7 days. The complex actions of sunlight and predacious microorganisms were variable depending upon the test organisms, but the total effects of those enviromental factors were yet completely understood.

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Environmental Risk Factors for Children and Adolescents Suffering from Depressive Disorder : Clinical Aspects (소아청소년 우울증에서의 환경적 위험 인자들과 임상적 의미)

  • Lee, Moon-Soo
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.21 no.3
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    • pp.141-146
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    • 2010
  • This summary of literature during the past year reviews published studies relating to risk factors for depressive disorders in children and adolescents. Risk factors include environmental toxins, socio-environmental, and genetic factors. As depression has a complex, multifactorial causal mechanism, it is likely that the accumulation and/ or interaction among multiple risk factors lead to depression. Findings related to the result of toxin exposure have been difficult to interpret given that risk factors tend to interact and that higher mental functions are not easily measurable. However, some findings have been consistent. Clinical research data has also shown that the risk for negative outcomes may be modified both by genetic and environmental factors through a gene environment interplay mechanism.

FABRY-PEROT SPECTROMETER IN ASTRONOMY (FABRY-PEROT 분광기의 특성과 천문학의 적용)

  • PAK SOOJONG
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc1
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    • pp.127-132
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    • 2000
  • The purposes of spectroscopy in astronomy are to measure the radiation flux of the spectroscopic emission or absorption line and to measure the dynamical parameters of the line profile. In order to use an appropriate instrument for the scientific purpose, we need to understand the characteristics of various spectrometers, e.g., a prism spectrometer, a grating spectrometer, and a Fabry-Perot spectrometer (FPS), which are being used in ultra-violet, optical, and infrared bands. The Fabry­Perot spectrometer is not very popular compared to the grating spectrometer, because of its complex and tricky operations. The Fabry-Perot spectrometer, however, can get a two-dimensional image at one exposure, so we can study radiation mechanisms and dynamical properties of extended sources, e.g., clusters, nebula, and galaxies.

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The Role of Innate and Adaptive Immune Cells in the Immunopathogenesis of Chronic Obstructive Pulmonary Disease

  • Nurwidya, Fariz;Damayanti, Triya;Yunus, Faisal
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.1
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    • pp.5-13
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    • 2016
  • Chronic obstructive pulmonary disease (COPD) is a chronic and progressive inflammatory disease of the airways and lungs that results in limitations of continuous airflow and is caused by exposure to noxious gasses and particles. A major cause of morbidity and mortality in adults, COPD is a complex disease pathologically mediated by many inflammatory pathways. Macrophages, neutrophils, dendritic cells, and CD8+ T-lymphocytes are the key inflammatory cells involved in COPD. Recently, the non-coding small RNA, micro-RNA, have also been intensively investigated and evidence suggest that it plays a role in the pathogenesis of COPD. Here, we discuss the accumulated evidence that has since revealed the role of each inflammatory cell and their involvement in the immunopathogenesis of COPD. Mechanisms of steroid resistance in COPD will also be briefly discussed.

Computational study of road tunnel exposure to severe wind conditions

  • Muhic, Simon;Mazej, Mitja
    • Wind and Structures
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    • v.19 no.2
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    • pp.185-197
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    • 2014
  • Ventilation and fire safety design in road tunnels are one of the most complex issues that need to be carefully considered and analysed in the designing stage of any potential upgrade of ventilation and other fire safety systems in tunnels. Placement road tunnels space has an important influence on fire safety, especially when considering the effect of adverse wind conditions that significantly influence ventilation characteristics. The appropriate analysis of fire and smoke control is almost impossible without the use of modern simulation tools (e.g., CFD) due to a large number of influential parameters and consequently extensive data. The impact of the strong wind is briefly presented in this paper in the case of a longitudinally ventilated road tunnel Kastelec, which is exposed to various severe wind conditions that significantly influence its fire safety. The possibility of using CFD simulations in the analysis of the tunnel placement in space terms negative effect of wind influence on the tunnel ventilation is clearly indicated.

A Study on the Expected Life Evaluation of Rotating Machine (회전 기기의 수명 예측 평가에 관한 연구)

  • Kim, Ki-Joon;Kim, Sang-Jin;Oh, Yong-Chei;Seong, Nak-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.10a
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    • pp.73-76
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    • 2000
  • Traction motors that is one of the rotating machines for urban transit EMU have been subjected to increased demand for higher operating temperature, more demanding duty cycles, higher starting current, frequent voltage transients and severe environmental exposure. With the advent of PWM drives using power IGBTs in addition to the thermal considerations, it is important to take into account the impact of the dielectric stress upon the winding insulation system life. In analyzing the life of the stator winding, which is the heart of the motor, the majority of all winding failures are usually caused by a combination of various stresses acting on the insulation materials and system. In this paper, to evaluate the expected life of traction motor for urban transit E.M.U. it is proposed a new test method of complex accelerating degradation.

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Effects of Acute Oral Administration of Mancozeb on the Immune Function in Mice (Mancozeb의 급성노출이 마우스의 면역기능에 미치는 영향)

  • 정애희;표명윤
    • YAKHAK HOEJI
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    • v.48 no.1
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    • pp.41-46
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    • 2004
  • Mancozeb, a polymeric complex of zinc and manganese salts of ethylene bisthiocarbamate (EBDC), is used widely in agriculture as fungicides, insecticides, and herbicides. Mancozeb can be occupationally and environmentally exposed to human and has been reported to induce estrogenic activity, therein it is considered as an endocrine disrupter, We investigated the effects of acute exposure of Mancozeb on the immune function in mice. After single oral administration of Mancozeb to female ICR mice, the immunopathological parameters (body- and organ-weight, splenic cellularity hematological parameters), mitogen (Con A, PHA+IL-2, LPS)-induced splenocyte proliferation (SP) and splenic IgM plaque forming cell (PFC). WBC and splenic cellularity were decreased, but liver-, kidney-, and spleen-weight were increased when compared with control group. Splenic IgM PFC against SRBC was slightly lowered. Mitogen-induced proliferation of spleen cells from Mancozeb-treated mice was not signifcantly changed ex vivo, however, SP in vitro were significantly lowered in concentration dependent manner. These results indicate that Mancozeb could affect the immune function in mice.