• 제목/요약/키워드: harmful materials

검색결과 529건 처리시간 0.023초

Expression of Bitter Taste Receptors in Human Nasal Respiratory Epithelium

  • An, Jeong-Mi;Wu, Hee-Won;Kim, Hyun-Jun;Kim, Chang-Hoon;Moon, Seok-Jun
    • International Journal of Oral Biology
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    • 제37권2호
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    • pp.57-62
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    • 2012
  • The nasal cavity encounters various irritants during inhalation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.

목재 및 목질재료 이용에 관한 환경적 연관효과 (Environment-Related Impacts on the Use of Wood and Wood-Based Materials)

  • 오세창
    • 임산에너지
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    • 제18권1호
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    • pp.37-45
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    • 1999
  • 온실효과는 이산화탄소의 과다방출로 인해 가장 심각한 환경문제가 되었다. 온실효과는 산림에서의 벌채, 특히 경작지를 위해 열대림지역이 파괴됨으로 인해 더욱 악화되고 있다. 나무는 대기중에서 이산화탄소를 흡수하므로 숲과 임산물은 이산화탄소를 이용하고 방출량을 줄이는데 큰 역할을 담당한다. 목재와 목제품은 철강, 알루미늄, 콘크리트와 같은 대체재료에 비해 제조에너지가 적게든다. 화석연료가의 높은 비용의 가능성이라는 관점에서 볼 때 목재가공에 있어서의 낮은 에너지소모량은 매우 중요하다. 또한 목재와 목제품은 탄소저장고로서의 역할을 한다. 따라서 목재는 환경적으로 바람직한 좋은 재료이다. 최근 산업용 재료의 사용에 있어서 목재와 다른 대체재에 관한 많은 논의가 진행되고 있다. 재료 선정은 누구나 할 수 있지만 선정시 다양한 측면을 고려하여야 한다. 앞서 언급하였듯이 목재는 환경적으로, 에너지 소모적인 면에서 우수한 재료이다. 그러므로 목재는 다른 대체재보다 환경에 미치는 영향이 적은 재료이다. 우리는 목재를 보다 효율적으로 이용하고 목재자원은 지속가능한 산림에서 제공되어야 할 것이다.

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뉴실버세대 여성을 위한 한지직물 활용 생활한복 디자인 개발 연구 - 대전 지역을 중심으로 - (A Study on Development of Casual Hanbok Design made of Hanji Yarn Textiles for the New Silver Generation Woman)

  • 한남기;박은희
    • 한국의류산업학회지
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    • 제10권5호
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    • pp.702-712
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    • 2008
  • The aim of this study is to develop Casual Hanbok design made of Hanji yarn textiles for New Silver generation women. The New silver generation is a coined word which has meaning of a newly silver generation and it is distinguished from pre-silver generation. New silver generation is a generation that is independent and given active role by their age groups and generational characteristic. The concept of silver generation was introduced from maturity market in Japan. This study was based on analysis about their preference of forms, colors, and materials of Casual Hanbok. The survey target were 270 female over age 50 living in Daejeon City. The analysis methods used frequency and percentage. The results were summarized as following. Although almost of them haven't worn Casual Hanbok, they had the positive recognition on wearing one. They preferred longer length jacket to traditional Korean style, shorter length of skirt. They also preferred the traditional sleeve shape and knotted buttons. On the foundation of this fact, 2 styles consist of 5 Casual Hanbok design items made of functional material - Hanji yarn textiles that have antimicrobial, deodorant, quick drying, far infrared radiation which are not harmful to health - for New silver women were suggested. One style was 3 items - blouse, vest, skirt - which are the sense of Korean tradition with activity by patch. The other was 2 items - jacket and skirt - which are the sense of Korean tradition with modern way by quilting. Lastly, these garments were evaluated by 13 experts, they were satisfied with 2 styles and all items. As this study were based on the Elderly women living in Daejeon city, it had the limitation on applying of preference styles to all the New silver generation.

Does Cervical Screening in Young Women Aged 20-25 Years Lead to Unnecessary and Harmful Interventions?

  • Al-Kalbani, Moza;Price, John;Thompson, Gwen;Ahmad, Sarfraz;Nagar, Hans
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권15호
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    • pp.6557-6559
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    • 2015
  • Background: Cervical human papillomavirus (HPV) infection among young women (20-25 years of age) is common and normally transient. There are growing concerns that referral to a colposcopy clinic may lead to unnecessary treatment with an increased risk of obstetric complications. Therefore, the purpose of this study was to determine the level of intervention for cervical abnormalities in this age group of the Northern Ireland population. Materials and Methods: A review of all serial new patients under 25 years of age, who were referred to colposcopy clinics in Northern Ireland between January 1, 2009 to June 30, 2009 formed the basis of this study. Results: During the study period, a total of 4,767 women under 25 years of age were screened. Two-hundred-and-thirty-four (4.9%) cases were referred to the colposcopy clinics. The cervical cytology results were: high-grade abnormality in 35%, and low-grade abnormality in 31% of these cases. One-hundred-and-seventy-eight (76%) of the referred women received at least one treatment. One-hundred-and-twenty-one of 234 (51.5%) women underwent an excisional treatment with histology showing the presence of high-grade abnormalities (CIN2-3) in 52%, CIN1 in 28%, and Koilocytosis or normal tissue in 20% of this sub-group of cases. Conclusions: Screening women under the age of 25 years cause unnecessary referral for colposcopy. This may also result in considerable anxiety and psychosexual morbidity. It leads to an over-treatment with a potential of negative impact on the future pregnancy outcomes (including pre-term delivery, low birth weight, and pre-term premature rupture of membranes).

새집증후군 현상 및 유해가스 제거방안 연구 (Research on the phenomenon of sick house syndrome and how to remove harmful gases)

  • 최유화
    • 문화기술의 융합
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    • 제6권3호
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    • pp.449-456
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    • 2020
  • 새 집으로 이사를 가거나 집, 사무실 등의 벽지나 바닥재를 바꿨을 때, 인테리어 공사를 한 뒤에 나타날 수 있는 코를 찌르는 매캐한 냄새와 눈이 따가워지는 등의 현상이 새집증후군으로 새집을 장만한 기쁨을 누리는 것도 잠시 뿐이다. 새 건축물이나 새 가구에 사용되는 건축자재, 접착제, 벽지, 페인트 등에서 나오는 휘발성 유기화합물들은 거주자들의 건강과 실내 생활의 불쾌감을 유발시킨다. 이 휘발성 유기화합물들은 대표적 물질인 포름알데히드를 비롯하여 벤젠, 톨루엔, 아세톤, 스틸렌 등이 포함되어 있고 이러한 물질들은 장시간에 걸쳐 서서히 방출되어 거주자들에게 급성 또는 만성적인 질환을 야기한다. 유기 휘발성 물질들의 제거 방법으로는 흡착을 이용한 물리적 방법과 휘발성 물질을 다른 물질로 전환시키는 화학적 방법 또는 두 가지가 혼합된 방법이 주로 사용된다. 본 논고에서는 반응물질의 반응속도와 생성물의 방출을 제어하는 방법으로 얻어지는 서방형의 이산화염소 젤팩과 최적화된 홀 경을 가진 제올라이트 흡착제를 혼용하여 공기 중에 부유하는 포름알데히드를 흡착, 분해시켜 제거하는 효과적인 방법에 대하여 제안하는 바이다.

복합열화촉진실험 및 장기현장폭로실험에 의한 RC구조물 보수공법의 보수성능평가 (Performance Evaluation of Repair Methods for RC structures by Accelerating Test in Combined Deterioration Chamber and Long-Term Field Exposure Test)

  • 권영진;김재환;한병찬;장승엽
    • 한국철도학회논문집
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    • 제9권4호
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    • pp.349-356
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    • 2006
  • At present, the selecting system and analytic estimation criterion on repair materials and methods of the deteriorated RC structures have not yet been set up in domestic. Under these circumstances, deterioration such as shrinkage crack, corrosion of rebar has been often occurred after repair, and this finally results in too frequent repairs. In this study, three types of repair methods were experimentally investigated by the accelerating test in a combined deterioration chamber and long-term field exposure test. Three types of repair methods applied in this study belong to a group of polymer cement mortar, which is commonly used in repair works. According to the results of this study, durability of repair mortar layers and corrosion properties of recovered rebar could be investigated in short period by the accelerating test in a combined deterioration chamber, which can simulate the condition of repeated high-and-low temperature and repeated dry-and-wet environment, spraying chloride solution and emitting $CO_2$ gas. After 36 month long-term filed exposure test in the coastal area, harmful macro-cracks are observed in the polymer cement mortar layer of some repair methods. These crack are considered to result from drying shrinkage of polymer cement mortar. Also, after 36 month exposure, amount of corrosion area and weight loss of rebar are found to be different according to the types of repair methods.

초미세입자 제거를 위한 나노세라믹 필터의 성능 평가 (Performance of Nano Ceramic Filter for the Removal of Ultra Fine Particles)

  • 김종원;안영철;이병권;정현재
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.751-756
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    • 2009
  • In the perspective of saving energy in buildings, the high performance of insulation and air tightness for improving the heating and the cooling efficiency, has brought economically positive effects. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and is also very harmful to the residents, because they spend over 90% of their time indoors. Therefore, the ventilation is important to keep the indoor environment clean and it can also save the energy consumption. In this study, a HEPA type nano ceramic filter is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. The double layer filter, which has $30{\mu}m$ in diameter at the conditions of 10wt% of concentration and 3kV/cm of the electric intensity, is produced by electrospinning. The filtration coating technology is confirmed in the solution with $SiO_2$ nano particles using polymer nano fibers. Also double layer filters are coated with $SiO_2$ nano particles and finally the porous construction materials are made by sintering in the electric furnace at $200{\sim}1400^{\circ}C$. The efficiency is measured 96.67% at the particle size of $0.31{\mu}m$, which is slightly lower than HEPA filter. However the efficiency is turned out to be sufficient.

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Responses of Various Biomarkers in Common Carp (Cyprinus carpio) Exposed to Benzo[k]fluoranthene

  • Kim, Woo-Keun;Kim, Ja-Hyun;Yeom, Dong-Hyuk;Lee, Sung-Kyu
    • 생태와환경
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    • 제41권3호
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    • pp.331-337
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    • 2008
  • Polycyclic aromatic hydrocarbons (PAHs) derived from leakage of fossil fuels and incomplete combustion of organic materials have been considered as harmful contaminants in environments. This study evaluated the effect of benzo[k]fluoranthene (BkF), one of the PAHs, using the multiple biomarkers and applied the integration model with those biomarker responses. After 10 days of the exposure at the measured concentrations of BkF (6, 25, and 45 ${\mu}g\;L^{-1}$), the changes of the four biomarkers, that is, 7-ethoxyresorufin-O-deethylase (EROD), DNA single-strand breaks (Comet), acetylcholinesterase (AChE) and vitellogenin (VTG) in the common carp (Cyprinus carpio) were observed. The standardized values of four biomarker responses were computed and integrated as star plots, representing Integrated Biomarker Respnse (IBR) values. DNA damage was induced in a dose-dependent manner, and increased significantly compared with that in the control. EROD and VTG levels were significantly elevated at low concentrations of BkF. On the other hand, AChE activities were not altered by BkF. IBR values increased as the exposure concentrations increased. Thus, the metabolic, endocrine and genetic changes of the biomarker responses in the common carp exposed to BkF should be considered in the case of the ecological risk assessment of the BkF in fish and it can be used as a biomonitoring tool in aquatic ecosystems. In addition, star plots can be used as a useful analysis tool in multibiomarker integration approach.

목제 주방용품 및 위생용품에 잔류하는 유해물질에 관한 연구 (Study on the Hazard Compounds from Wooden Kitchenwares and Sanitary Produce)

  • 이광호;유승석;윤혜정;김길생
    • 한국포장학회지
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    • 제5권1호
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    • pp.21-24
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    • 1999
  • 시중 유통되고 있는 50종의 목제 주방기구와 위생용품을 각각 benzene과 n-heptane에 용출시켜 GC-MSD를 이용하여 분석한 결과, naphthalene과 diethyl phthalate는 모든 조건에서 검출되지 않았으나, biphenyl의 경우 전 제품에서 미량이 검출되었다. Biphenyl은 자작나무 수입 원목과 국산 원목에서도 각각 0.25 ppm, 0.34 ppm 함유되어 있는 것으로 확인되었다. 또한 biphenyl의 검출량은 목제를 가공하는 과정 중에 감소하며, 그 검출량은 과일의 잔류 허용치 (110 ppm)에 비해 극히 미량인 것으로 판단된다. 따라서 biphenyl의 유입경로는 제품의 제조 및 생산과정에서 첨가되었다기 보다는 제제 자체에 잔존한다고 추정되며, 이러한 biphenyl의 잔존량은 인체에 영향을 미칠 수 있는 농도는 아닌 것으로 판단된다.

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Predictors of Cigarette Smoking among Young Adults in Mangalore, India

  • Lalithambigai, G;Rao, Ashwini;Rajesh, G;Ramya, Shenoy;Pai, BH Mithun
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권1호
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    • pp.45-50
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    • 2016
  • Background: The tobacco epidemic is a heralding health menace, particularly among college students. Tobacco usage among young can have an especially devastating effect as they can be exposed for longer periods. Data to estimate the prevalence of tobacco use in young adults will be a valuable addition to the existing resources. Materials and Methods: An analytical cross-sectional study was therefore carried out in Mangalore city using a pre-tested, self-administered questionnaire adapted from the Global Youth Tobacco Survey (GYTS) with a representative sample of 720 students aged 18-20 years selected from degree colleges by multi-stage random sampling. Results: Prevalence of 'ever users' and 'current users' of smoking were 20.4% and 11.4%, respectively. The mean age at initiation of cigarette smoking was 16 years and the majority (31 %) smoked in public places. Interestingly, 84% of them knew about the harmful effects of cigarette smoking. About one half of smokers had some or most of their friends smoking. Multivariate analysis revealed gender (OR=8.585: CI-3.26-22.5), pocket money (OR=4.165; CI=1.76-9.82) and peer's smoking habit (OR= 5.15; CI-2.21-11.9) have higher odds as correlates of tobacco usage among college students. Conclusions: It is of prime importance to highlight the role of prevention of smoking initiation rather than subsequently trying to stop the habit. Comprehensive interventions embracing family, friends and social milieu are needed to reduce tobacco use among students in India.