• Title/Summary/Keyword: harmful materials

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A Study on the Fabrication of Surface Heating Panel Using SiC Ceramics (SiC계 세라믹을 이용한 면상발열 판넬 개발에 관한 연구)

  • Cho, Hyun-Seob
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.9 no.6
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    • pp.604-608
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    • 2016
  • In recent years, research and development has been carried out in order to increase the economical efficiency and stability in terms of efficient use of energy for the heating apparatus. Especially, technology development for high performance and new functional materials is actively being carried out. This paper focuses on the development of exothermic products with excellent energy transfer characteristics. The heating element used for bedding or mattress uses a heating wire. Since the heating wire is thin, the distribution of heat is concentrated only around the heating wire,. In addition, electromagnetic induction is harmful to the human body and energy consumption is high. Therefore, it is aimed to develop a planar heating panel using SiC ceramics which can radiate far-infrared rays and anions to be harmless to the human body, but also has excellent heat conduction to enhance energy efficiency.

Anti-Diabetic Medications Do Not Influence Risk of Lung Cancer in Patients with Diabetes Mellitus: a Systematic Review and Meta-analysis

  • Nie, Shu-Ping;Chen, Hui;Zhuang, Mao-Qiang;Lu, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6863-6869
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    • 2014
  • Objectives: Several preclinical and observational studies have shown that anti-diabetic medications (ADMs) may modify the risk of lung cancer. We performed a systematic review and meta-analysis evaluating the effect of metformin, sulfonylureas (SUs), thiazolidinediones (TZDs), and insulin on the risk of lung cancer in patients with diabetes mellitus (DM). Materials and Methods: We conducted a systematic search of Pubmed and Web of Science, up to August 20, 2013. We also searched the Conference Proceedings Citation Index (CPCI) and China National Knowledge Infrastructure (CNKI) for abstracts from major meetings. Fixed or random effect pooled measures were selected based on heterogeneity among studies, which was evaluated using Q test and the I2 of Higgins and Thompson. Meta-regression was used to explore the sources of between-study heterogeneity. Publication bias was analyzed by Begg's funnel plot and Egger's regression test. Associations were assessed by odds ratios (ORs) with 95% confidence intervals (CIs). Results: A total of 15 studies (11 cohort, 4 case-control) were included in this meta-analysis. In observational studies no significant association between metformin (n=11 studies; adjusted OR=0.99, 95%CI: 0.87-1.12), SUs (n=5 studies; adjusted OR=0.98, 95%CI: 0.79-1.22), or TZDs (n=7 studies; adjusted OR=0.92, 95%CI: 0.75-1.13), insulin (n=6 studies; adjusted OR=1.13, 95%CI: 0.79-1.62) use and risk of developing lung cancer was noted. There was considerable inherent heterogeneity between studies not explained by study design, setting, or location. Conclusions: Meta-analysis of existing studies does not support a protective or harmful association between ADMs use and risk of lung cancer in patients with DM. There was considerable heterogeneity across studies, and future, well-designed, prospective studies would be required for better understanding of any association.

Clinical, Cytogenetic and CYP1A1 exon-1 Gene Mutation Analysis of Beedi Workers in Vellore Region, Tamil Nadu

  • Sundaramoorthy, Rajiv;Srinivasan, Vasanth;Gujar, Jidnyasa;Sen, Ayantika;Sekar, Nishu;Abilash, Valsala Gopalakrishnan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7555-7560
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    • 2013
  • Background: Beedi rollers are exposed to unburnt tobacco dust through cutaneous and pharyngeal route and it is extremely harmful to the body since it is carcinogenic in nature and can cause cancer during long exposure. This indicates that occupational exposure to tobacco imposes considerable genotoxicity among beedi workers. Materials and Methods: In the present study, 27 beedi workers and age and sex matched controls were enrolled for clinical, cytogenetics and molecular analysis. Clinical features were recorded. The workers were in the age group of 28-67 years and were workers exposure from 8-60 years. Blood samples were collected from workers and control subjects and lymphocyte cultures were carried out by using standard technique, slides were prepared and 50 metaphases were scored for each sample to find the chromosomal abnormalities. For molecular analysis the genomic DNA was extracted from peripheral blood, to screen the variations in gene, the exon 1 of CYP1A1 gene was amplified by polymerase chain reaction (PCR) and then screened with Single Strand Conformation Polymorphism (SSCP) analysis. Results: A statistically significant increase was observed in the frequencies of chromosomal aberrations in exposed groups when compared to the respective controls and variations observed in Exon 1 of CYP1A1(Cytochrome P450, family 1, subfamily A, polypeptide 1) gene. Conclusions: This study shows that, the toxicants present in the beedi that enter into human body causes disturbance to normal state and behavior of the chromosomes which results in reshuffling of hereditary material causing chromosomal aberrations and genomic variations.

Study on the Relationship between Dae-Jang-Jung-Gyeok(大腸正格) and Leaky Gut Syndrome (대장정격증(大腸正格證)과 장누수증후군(Leaky Gut Syndrome)과의 관계 고찰(考察))

  • Lee, Jin-Cheoul;Park, Sang-Kyun;Bang, Jung-Kyun
    • Journal of Korean Medical classics
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    • v.26 no.4
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    • pp.105-116
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    • 2013
  • Objective : If the penetration ratio of the intestinal mucosa is increased, the toxic or unhealthy materials - which should not be absorbed into our bodies - will be come into our bodies. They cause a sort of anti-toxic response or confusion of the immune system, and ultimately bring various types of diseases. This syndrome is related "Poison in Excrement" or "Internal Damage(內傷發癍)" and Leaky Gut Syndrome, so I will study on the relationship between them. Method : Study on the relationship between Dae-Jang-Jung-gyeok and Leaky Gut Syndrome. Result : Korean doctors in ancient times called this syndrome "Poison in Excrement" or "Internal Damage(內傷發癍)" and treated it with "Dae-Jang-Jung-Gyeok(大腸正格)". Leaky Gut Syndrome is a sort of clinical lesion, which allows foreign and harmful toxins in and results in a disorder of the immune system due to the leaking intestinal mucosa. Conclusion : Based upon the analyses, Dae-Jang-Jung-Gyeok and Leaky Gut Syndrome are closely related. Therefore diseases caused by the Leaky Gut Syndrome might be expected to be cured by Dae-Jang-Jung-Gyeok. Particularly the use of treatments for self-immune diseases and allergic diseases such as atopyic dermatitis and articular rheumatism should be expected to reveal a new path of treatment for other disorders such as Leaky Gut Syndrome.

Safflower Seed Oil and Its Active Compound Acacetin Inhibit UVB-Induced Skin Photoaging

  • Jeong, Eun Hee;Yang, Hee;Kim, Jong-Eun;Lee, Ki Won
    • Journal of Microbiology and Biotechnology
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    • v.30 no.10
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    • pp.1567-1573
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    • 2020
  • Ultraviolet (UV) is one of the major factors harmful to skin health. Irradiation with ultraviolet accelerates the decline of skin function, causing the skin to have deep wrinkles, dryness, decreased procollagen production, and degradation of collagen. Novel materials are needed to prevent the aging of the skin by blocking the effects of UV. Safflower seed oil (Charthamus tinctorius L., SSO) contains significantly high levels of unsaturated fatty acids and phytochemicals. SSO has been traditionally used in China, Japan, and Korea to improve skin and hair. Our objective in this study was to determine the effect of SSO and its active compound acacetin on UVB-induced skin photoaging in HaCaT cells and human dermal fibroblasts (HDF). SSO inhibited UVB-induced matrix metalloproteinase-1 (MMP-1) at both protein and mRNA levels in HaCaT cells and HDF. MMP-1 is known to play important roles in collagen degradation and wrinkle formation. Acacetin, a type of flavonoid, is present in SSO. Similar to SSO, acacetin also inhibited UVB-induced MMP-1 protein and mRNA levels in HaCaT cells and HDF. MMP-1 mRNA is primarily regulated by the mitogen-activated kinase (MAPK) signaling pathway. Acacetin regulated the phosphorylation of JNK1/2 and c-jun, but did not inhibit the phosphorylation of ERK1/2, p38 and AKT. Taken together, these results indicate that SSO and its active compound acacetin can prevent UVB-induced MMP-1 expression, which leads to skin photoaging, and may therefore have therapeutic potential as an anti-wrinkle agent to improve skin health.

BRAZING CHARACTERISTICS BETWEEN CEMENTED CARBIDES AND STEEL USED BY AG-IN BRAZING FILLER

  • Nakamura, Mitsuru;Itoh, Eiji
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.551-554
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    • 2002
  • As a general rule, the brazing process between cemented carbides and steel used by Silver (Ag) type brazing filler. The composition of Ag type filler were used Ag-Cu-Zn-Cd type filler mainly. But, the demand of Cadmium (Cd)-free in Ag type filler was raised recently. The reason why Cd-free in Ag brazing filler were occupied to vaporize as a CdO$_2$ when brazing process, because of Cd element was almost low boiling point of all Ag type filler elements. And, CdO$_2$ was a very harmful element for the human body. This experiment was developed Cd-freeing on Ag type filler that was used Indium (In) instead of Cd element. In this experiment, there were changed from 0 to 5% In addition in Ag brazing filler and investigated to most effective percentage of Indium. As a result, the change of In addition instead of Cd, there was a very useful element and obtained same property only 3% In added specimens compared to Cd 19% added specimens. These specimens were obtained same or more deflective strength. In this case, there were obtained 70 MPa over strength and wide brazing temperature range 650-800 C. A factor of deflective strength were influenced by composition and the shape of $\beta$ phase and between $\beta$ phase and cemented carbides interface. Indium element presented as $\alpha$ phase and non-effective factor directly, but it's occupied to solid solution hardening as a phase. $\beta$ phase were composed 84-94% Cu-Ni-Zn elements mainly. Especially, the presence of Ni element in interface was a very important factor. Influence of condensed Ni element in interface layer was increased the ductility and strength of brazing layer. Therefore, these 3% In added Ag type filler were caused to obtain a high brazing strength.

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Study on occurrence and management of organic micropollutants in sewer systems (국내·외 하수도시설 미량유기물질의 발생 특성 및 관리체계에 대한 이해)

  • Jeong, Dong-Hwan;Ham, Sang-Yee;Lee, Wonseok;Chung, Hyenmi;Kim, Hyunook
    • Journal of Korean Society of Water and Wastewater
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    • v.31 no.6
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    • pp.551-566
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    • 2017
  • As the modern society is rapidly developing and people become affluent in materials, many new chemical compounds in different forms of products (e.g., antibiotics, pesticides, detergents, personal care products and plastic goods) are produced, used, and disposed of to the environments. Some of them are persistently having a harmful impact on the environment and mimicking endocrine properties; in general they are present in the environment at low concentrations, so they are called organic pollutants. These organic micropollutants flow to sewage treatment plants via different routes. In this study, the generation characteristics, exposure pathways, detection levels, and environmental impacts of organic micropollutants were critically reviewed. In addition, currently available risk assessment methods and management systems for the compounds were reviewed. The United States Environmental Protection Agency (US EPA), for example, has monitored organic micropollutants and set the monitoring and management of some of the compounds as a priority. To effectively manage organic micropollutants in sewer systems, therefore, we should first monitor organic micropollutants of potential concern and then make a watch list of specific substances systematically, as described in guidelines on listing water pollutants in industrial wastewater.

Occupational Diseases Among Office Workers and Prevention Strategies

  • Lee, Jongin;Koo, Jung-Wan
    • Journal of the Ergonomics Society of Korea
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    • v.34 no.2
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    • pp.125-134
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    • 2015
  • Objective: In this review we discuss the health effects among office workers. Background: Even if office workers are not exposed hazardous or harmful environment frequently, some problems could be happened to the office workers. Although serious occupational diseases rarely occur to the office workers, it is important to consider occupational risk factors for the office worker because the portion of the office workers is relatively high in all industries. Method: We divided possible health effects for the office workers into three categories; musculoskeletal disorders, indoor environment, and cerebro-cardiovascular diseases. We reviewed related articles, textbooks, and statistical materials non-systematically and described risk factors, related illnesses, and prevention strategies on each category. Results: Office workers have various musculoskeletal disorders to be intervened. By medical treatment, improving working environment, and ergonomic intervention, office workers can be prevented from musculoskeletal injuries. Poor indoor environment can cause many building-related illnesses or sick building syndrome. Although the etiology of some problems by poor indoor environment is not clear, it helps to maintain adequate humidity, temperature, and clarity of indoor air. Cerebro-cardiovascular diseases are a rising issue because office workers in Korea tend to work for a lot of time. To prevent the diseases, it is needed to work for adequate time, lengthen activity level, and manage other medical risk factors for the diseases. Conclusion: There is no distinct occupational disease for office workers. However, there are some aspects to consider the health effects of office workers and it is important to prevent the possible health problems. Application: A strategy against occupational diseases among office workers can be established by reviewing this article.

Prevention and the characteristics of drug abusers among Japanese junior high school students : A comparative study of drug users and non-drug users (예방적 측면에서 본 일본 청소년의 약물남용자의 특징 -약물남용자와 비남용자의 비교 연구-)

  • Oh, Hak
    • Korean Journal of Health Education and Promotion
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    • v.11 no.2
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    • pp.57-67
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    • 1994
  • The aim of this study was to research and compare the demographic characteristics of drug abusers with non-drug abusers among junior high school students in Japan through a closed format questionnaire. The same questionnaire and face-to-face interviews were used in order to find the circumstances of drug abuser among Kyogoin(a sort of child welfare institution) students in Japan. The goal of the study was to provide basic materials for preventive education of drug abuse through the two investigations mentioned above. Between July 1993 and November 1993, the information for this study was collected from 964 students from 4 junior high schools, and also 142 students from 3 Kyogoin in Japan. A total of 1106 questionnaires were completed resulting in a following response rate of 90.4%. Information was based on the scales : family relation scale, school life scale, recognition on danger of drug abuse scale, family environment scale (Moos, 1986), self esteem inventory (Coopersmith, 1967), etc. The conclusions can be summarized as follows : 1. Drug abusers are more likely to lake communication in their families and have poorer human relations than non-drug abusers. Also their school life scores tended to be lawer non-drug abusers. 2. It was between their 6th year of elementary school and their first of Junior high school when the drug was first used. The drug of choice which they made their first attempt at using was a volatile solvent which was inhaled. It is likely that this drug is "gateway-drug" for adolescents in Japan because they then also tried other drugs (e.g. cocaine, marijuana, etc.) step by step. 3. It is therefore clearly important that greatly increasing education on the harmful effects of drug abuse before the summer vacation of the first term of the sixth year of elementary school. At the same time, intervention in the family will have an effective prevention strategy in Japan, as well., as well.

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The Bisphenol A: A Modulator of Pregnancy in Rats

  • Kim, Pan-Gyi;Lee, Na-Rae;Hwang, Seong-Hee
    • Journal of Environmental Health Sciences
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    • v.29 no.4
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    • pp.27-34
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    • 2003
  • Bisphenol A is used in the manufacture of epoxy, polycarbonate, and corrosion-resistant unsaturated polyester-styrene resins required for food packaging materials in industrial processing. Some reports indicated the possibility of harmful effects on rats. In this study was used a method for the determination of bisphenol A in blood according to the OSHA High Performance Liquid Chromatography (HPLC) guideline. The method involved blood extraction using methylene chloride. And it was evaluated developmental and teratogenic effects in pregnant rats and second generation. The results obtained were as follows. There was a significant increase in the body weights and treated groups F1 female in liver, spleen, kidney, but according to dose-response. F1 female rat's relative body weight and absolute body weight are not different. There was a significant increase liver, spleen, kidney organ weight and reproductive organ weight epididymis, prostate gland in F1 male rats. There was a proestrous in pregnant rat, group 200 $\mu\textrm{g}$/kg, 2000 $\mu\textrm{g}$/kg, 20,000 $\mu\textrm{g}$/kg. The effect on rat treated with bisphenol A decrease organ weight and reproductive organ weight. Identification and quantitation were performed with using HPLC C18 column and using at retention time 5.5 min. The results of the detection of bisphenol A were at 20,000 $\mu\textrm{g}$/kg in average 1 $\mu\textrm{g}$/ml, 200 $\mu\textrm{g}$/kg average in 0.9 $\mu\textrm{g}$/ml blood samples. From those results, it could be concluded that the effects of pregnant rat and second generation(F1) by bisphenol A treatment during lactational period were estrogenic and bisphenol A was remained in serum at low level.