• Title/Summary/Keyword: exposure factors

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Influence of Relative humidity on the CO2 Diffusion Coefficient in Concrete (콘크리트 중의 이산화탄소 확산계수에 대한 상대습도 영향 연구)

  • Oh, Byung-Hwan;Jung, Sang-Hwa;Lee, Myung-Kun
    • Journal of the Korea Concrete Institute
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    • v.15 no.6
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    • pp.778-784
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    • 2003
  • The carbonation of concrete is one of the major factors that cause durability problems in concrete structures. The rate of carbonation depends largely upon the diffusivity of carbon dioxide in concrete. The purpose of this study is to identify the diffusion coefficients of carbon dioxide for various concrete mixtures. To this end, several series of tests have been planned and conducted. The test results indicate that the diffusion of carbon dioxide reached the steady-state within about five hours after exposure. The diffusion coefficient increases with the increase of water-cement ratio and decreases with the increase of relative humidity at the same water-cement ratio. The content of aggregates also influences the diffusivity of carbon dioxide in concrete. It was found that the diffusion coefficient of cement paste is larger than that of concrete or mortar. The experimental study of carbon dioxide diffusivity in this study will allow more realistic assessment of carbonation depth in concrete structures.

Gene Structure and Altered mRNA Expression of Metallothionein in Response to Metal Exposure and Thermal Stress in Miho Spine Loach Cobitis choii (Cobitidae; Cypriniformes) (미호종개 metallothionein 유전자의 구조 및 중금속 노출과 고온 자극에 대한 MT mRNA의 발현 특징 분석)

  • Lee, Sang-Yoon;Nam, Yoon-Kwon
    • Korean Journal of Ichthyology
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    • v.23 no.1
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    • pp.61-69
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    • 2011
  • Gene and promoter structures of metallothionein(MT) from Miho spine loach (Cobitis choii; Cypriniformes) were characterized, and the transcriptional responses to experimental exposures to heavy metals and heat stress were examined. The C. choii metallothionein displayed well-conserved features of teleostean metallothioneins at gDNA, mRNA and amino acid levels. Bioinformatic analysis predicted that the C. choii MT regulatory region potentially possessed various motifs or elements targeted by various transcription factors associated with metal-coordinating regulation (e.g., metal transcription factor-1), immune responses (e.g., nuclear factor kappa B), and thermal modulations (e.g., heat shock factor). Acute heavy-metal exposures to 0.5 or $1.0\;{\mu}M$ of cadmium (Cd), copper (Cu), manganese (Mn), nickel (Ni) or zinc (Zn) showed that MT transcription was significantly stimulated by Cd (9.6-fold relative to non-exposed control) and Cu (10.4-fold), only moderately by Mn (2.4-fold), but hardly by Ni and Zn. Elevation of water temperature from $25^{\circ}C$ to $31^{\circ}C$ caused a rapid modulation of MT mRNAs toward upregulation to 9.5-fold; however, afterward the elevated mRNA level slightly decreased during further incubation at $31^{\circ}C$ for 6 h. Results from this study suggest that MT-based expression assay could be a useful basis for better understanding the metal- and/or heat-caused stresses in this endangered fish species.

Molecular Characterization of Metallothionein Gene of the Korean Bitterling Acheilognathus signifer (Cyprinidae) (묵납자루 (Acheilognathus signifer; Cyprinidae) metallothionein 유전자의 클로닝 및 특징 분석)

  • Lee, Sang-Yoon;Bang, In-Chul;Nam, Yoon-Kwon
    • Korean Journal of Ichthyology
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    • v.23 no.1
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    • pp.10-20
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    • 2011
  • Genetic determinant for metallothionein (MT), a cysteine-rich protein playing essential roles in metal detoxification and homeostasis, was characterized in the Korean bitterling (Acheilognathus signifer, Cyprinidae), an endemic fish species. The full-length A. signifer MT (AsMT) cDNA (551 bp) is composed of a single open-reading frame (ORF) to encode a polypeptide of 60 amino acids containing 20 cysteine residues whose positions are conserved in most cypriniform MTs. At the genomic level, the AsMT (2,593 bp spanning the 5'-flanking region to the 3'-untranslated region) represented a conserved tripartite (three exons interrupted by two introns) structure with AT-rich introns. The upstream regulatory region (-1,914 bp from the ATG initiation codon) of AsMT displayed various sites and motifs for transcription factors involved in the metal-mediated regulation and stress/immune responses. The AsMT transcript was ubiquitously detected in various organs with variable expression levels, where the ovary and intestine showed the highest expression, while the heart and skeletal muscle represented the lowest level. During an exposure to copper (immersion in $0.5\;{\mu}M$ Cu for 48 h), the levels of AsMT transcripts were significantly elevated in the liver (more than 3.5-fold), moderately in the gill, kidney, and spleen (ranging from 1.5- to 2.5-fold), and barely in the brain and intestine. Results of this study could form a useful basis to explore the metal-related stress physiology of this endangered fish species.

Tardive Dyskinesia and Tardive Dystonia with Second-Generation Antipsychotics in Bipolar Disorder Patients Unexposed to First-Generation Antipsychotics (양극성 장애 환자에서 비정형 항정신병약물 치료 후에 나타나는 지연성 운동장애와 지연성 근긴장이상의 유병률 및 위험요인)

  • Lee, Ahram;Kim, Joo Hyun;Baek, Ji Hyun;Kim, Ji Sun;Choi, Mi Ji;Yoon, Se Chang;Ha, Kyooseob;Hong, Kyung Sue
    • Korean Journal of Biological Psychiatry
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    • v.22 no.4
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    • pp.155-162
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    • 2015
  • Objectives Second-generation antipsychotics (SGAs) are frequently used in the treatment of bipolar disorder. However, there is still no consensus on their risk of tardive movement syndromes especially for first-generation antipsychotics (FGAs)-naïve patients. This study aimed to investigate the prevalence and associated factors of SGAs-related tardive dyskinesia and tardive dystonia in patients with bipolar disorder, in a naturalistic out-patient clinical setting. Methods The authors assessed 78 non-elderly patients with bipolar (n = 71) or schizoaffective disorder (n = 7) who received SGAs with a combined use of mood stabilizers for more than three months without previous exposure to FGAs. Multiple direct assessments were performed and hospital records longer than one recent year describing any observed tardive movement symptoms were also reviewed. Results The prevalence rates of tardive dyskinesia and tardive dystonia were 7.7% and 6.4%, respectively. These patients were being treated with ziprasidone, risperidone, olanzapine, quetiapine, or paliperidone at the time of the onset of the movement symptoms. Tardive dyskinesia was mostly observed in the orolingual area, and tardive dystonia was most frequently detected in oromandibular area. A past history of acute dystonia was significantly associated with presence of both tardive movement syndromes. Conclusions Our findings suggest that SGAs-related tardive movement syndromes occur in a substantial portion of bipolar disorder patients. Acute dystonia, a reported risk factor of tardive movement syndromes in the era of FGAs is confirmed as a risk factor of both tardive dyskinesia and tardive dystonia that were induced-by SGAs.

Toxicity Factor Analysis through the Exposure Experiment of the Combustion Products on Wood-Based Materials (목재 기반 소재의 연소생성물 노출 실험을 통한 독성요인 분석)

  • Kim, Nam-Kyun;Park, Jeong-Ho;Cho, Nam-Wook
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.57-63
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    • 2016
  • In this study, the toxicity of combustion products of wood-based materials (MDF, OSB) were analyzed using experimental animal techniques. The average deed stopping time of MDF was shorter than that of OSB. This means that the toxicity of the combustion products of MDF is higher than that of OSB. To analyze the cause of the result quantitatively, Fourier transform infrared spectroscopy (FT-IR) of the gas phase materials was performed. Qualitative analysis result, CO and $CO_2$ were detected. Quantitative analysis results, the gas generation rate was higher in OSB than in MDF. Blood analysis of mice revealed, COHb to be higher in OSB than MDF. A correlation between the gas generation rate and COHb was found. Currently, the toxicity of the combustion products of the materials is being examined using the toxicity index, such as Fractional Effective Dose (FED). The FED is based on the gas emissions. The average deed stopping time decreased with increasing toxicity of exposed material. On the other hand, the result of this study showed that, the CO emissions of OBS were 186.5% that of MDF. The COHb of OSB was > 129.6% that of MDF. Nevertheless, the average deed stopping time of the OSB is 51 seconds longer than that of MDF. Therefore, more toxicity studies on factors other than the gas phase materials in the combustion products will be needed.

Current Trends and Recent Advances in Diagnosis, Therapy, and Prevention of Hepatocellular Carcinoma

  • Wang, Chun-Hsiang;Wey, Keh-Cherng;Mo, Lein-Ray;Chang, Kuo-Kwan;Lin, Ruey-Chang;Kuo, Jen-Juan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3595-3604
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    • 2015
  • Hepatocellular carcinoma (HCC) has been one of the most fatal malignant tumors worldwide and its associated morbidity and mortality remain of significant concern. Based on in-depth reviews of serological diagnosis of HCC, in addition to AFP, there are other biomarkers: Lens culinaris agglutinin-reactive AFP (AFP-L3), descarboxyprothrombin (DCP), tyrosine kinase with Ig and eprdermal growth factor (EGF) homology domains 2 (TIE2)-espressing monocytes (TEMs), glypican-3 (GPC3), Golgi protein 73 (GP73), interleukin-6 (IL-6), and squamous cell carcinoma antigen (SCCA) have been proposed as biomarkers for the early detection of HCC. The diagnosis of HCC is primarily based on noninvasive standard imaging methods, such as ultrasound (US), dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI). Some experts advocate gadolinium diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and contrast-enhanced US as the promising imaging madalities of choice. With regard to recent advancements in tissue markers, many cuting-edge technologies using genome-wide DNA microarrays, qRT-PCR, and proteomic and inmunostaining studies have been implemented in an attempt to identify markers for early diagnosis of HCC. Only less than half of HCC patients at initial diagnosis are at an early stage treatable with curative options: local ablation, surgical resection, or liver transplant. Transarterial chemoembolization (TACE) is considered the standard of care with palliation for intermediate stage HCC. Recent innovative procedures using drug-eluting-beads and radioembolization using Yttrium-90 may exhibit beneficial effects in HCC treatment. During the past few years, several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Sorafenib is currently the only approved systemic treatment for HCC. It has been approved for the therapy of asymptomatic HCC patients with well-preserved liver function who are not candidates for potentially curative treatments, such as surgical resection or liver transplantation. In the USA, Europe and particularly Japan, hepatitis C virus (HCV) related HCC accounts for most liver cancer, as compared with Asia-Pacific regions, where hepatitis B virus (HBV) may play a more important role in HCC development. HBV vaccination, while a vaccine is not yet available against HCV, has been recognized as a best primary prevention method for HBV-related HCC, although in patients already infected with HBV or HCV, secondary prevention with antiviral therapy is still a reasonable strategy. In addition to HBV and HCV, attention should be paid to other relevant HCC risk factors, including nonalcoholic fatty liver disease due to obesity and diabetes, heavy alcohol consumption, and prolonged aflatoxin exposure. Interestingly, coffee and vitamin K2 have been proven to provide protective effects against HCC. Regarding tertiary prevention of HCC recurrence after surgical resection, addition of antiviral treatment has proven to be a rational strategy.

Cigarette Smoking and Pancreatic Cancer Risk: A Revisit with an Assessment of the Nicotine Dependence Phenotype

  • Nakao, Makoto;Hosono, Satoyo;Ito, Hidemi;Oze, Isao;Watanabe, Miki;Mizuno, Nobumasa;Yatabe, Yasushi;Yamao, Kenji;Niimi, Akio;Tajima, Kazuo;Tanaka, Hideo;Matsuo, Keitaro
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4409-4413
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    • 2013
  • Background: Cigarette smoking is a well-established risk factor of pancreatic cancer (PC). Although an association between nicotine dependence phenotype, namely time to first cigarette (TTFC) after waking, and the risk of several smoking-related cancers has been reported, an association between TTFC and PC risk has not been reported. We assessed the impact of smoking behavior, particularly TTFC, on PC risk in a Japanese population. Materials and Methods: We conducted a case-control study using 341 PC and 1,705 non-cancer patients who visited Aichi Cancer Center in Nagoya, Japan. Exposure to risk factors, including smoking behavior, was assessed from the results of a self-administered questionnaire. The impact of smoking on PC risk was assessed with multivariate logistic regression analysis adjusted for potential confounders to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Cigarettes per day (CPD) and/or smoking duration were significantly associated with PC risk, consistent with previous studies. For TTFC and PC risk, we found only a suggestive association: compared with a TTFC of more than 60 minutes, ORs were 1.15 (95%CI, 0.65-2.04) for a TTFC of 30-60 minutes and 1.35 (95%CI, 0.85-2.15) for that of 0-30 minutes (p trend=0.139). After adjustment for CPD or smoking duration, no association was observed between TTFC and PC. Conclusions: In this study, we found no statistically significant association between TTFC and PC risk. Further studies concerning TTFC and PC risk are warranted.

Age- and Gender- Specific Reference Levels for Hearing Thresholds of Normal Aging in Korean (한국인의 정상적인 노화에 의한 성별 연령별 순음청력에 의한 기준청력)

  • Kim Sung Hee;Shin Jong Heon;Yeo Chang Ki;Han Young Kyung;Lee Jung Ki;Jarng Soon Suck
    • The Journal of the Acoustical Society of Korea
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    • v.24 no.6
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    • pp.353-357
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    • 2005
  • Declining auditory performance with advanced age is a well known and common problem that is becoming more Prevalent due to the increasing number of elderly people in our society. We introduce a novel ARCISM (Audiogram Result Computer Input. Save & Management software) data management program which enables the assessment of the risk of past history of hearing impairment on the basis of known risk factors. This study investigates the reference levels of pure tone hearing threshold of normal aging in Korean and the difference between fenders. The subjects were carefully selected by questionnaire and absence of any history of otologic infection, noise exposure. and ototoxic drug among 1603 subjects. who visited Health Promotion Center in Daegu Fatima Hospital for one year. The results show (1) hearing sensitivity declines with age. (2) higher frequency shows steeper slope of hearing declines than lower frequency. and (3) there were more hearing loss at 4 and 8 kHz in men than in women. Due to the ARCISM program. it was possible to manage huge data of hearing results and to obtain the reference level of a9e-related hearing declines. Furthermore, we expect that the results of this study can be the fundamental data for hearing rehabilitation for the elderly and for developing suitable hearing aids for Korean.

Epidemiologic Study of Poisoned Patients Who Presented to the Emergency Department of a High end Medical Facility in Seoul 1998~2009 (1998~2009 서울지역 일개 상급의료기관 응급센터에 내원한 중독환자의 역학적 고찰)

  • Lee, Jae-Hoon;Oh, Sang-Hoon;Park, Kyu-Nam;Youn, Chun-Song;Kim, Soo-Hyun;Jeong, Won-Jung;Kim, Han-Joon
    • Journal of The Korean Society of Clinical Toxicology
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    • v.8 no.1
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    • pp.7-15
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    • 2010
  • Purpose: There are an insignificant number of studies done on the demographics of intoxication patients and on the characteristics of toxic exposure on a long term basis in Korea. The objective of our survey is to investigate the epidemiologic characteristics of intoxication in a metropolitan emergency department in order to more efficiently manage intoxication patients. Methods: We retrospectively reviewed the medical records of intoxication patients who visited the emergency department of a high end medical facility between January, 1998 and June, 2009. We investigated the trend of the substances people became intoxicated with during the study period and we analyzed the age, gender, year and distribution of patients and the outcome of the patients. Results: There were 1544 cases of intoxication during the study period, and the cases made up 0.37% of the total visitors to our emergency department, which is a high end medical facility located in the city. Most of the patients were female (70%) in their twenties and thirties. The most commonly ingested intoxication substances were sedatives, analgesics and pesticides. Unlike in the province, antidepressant abuse is on the rise while pesticide abuse is falling. The overall admission rate was 24.8% and the mortality rate was 1.6%. Pesticides intoxication was the most common cause of death (76%). Pesticides intoxication, a male gender and old age were the most significant fatality-related factors. Conclusion: We think that there is a need to investigate the actual conditions of drug intoxication in the city and prepare measures to prevent drug intoxication.

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Correction of Recurrent Ingrowing Toenail Using Partial Matricectomy and Paronychial Advancement Flap (부분기질절제술과 발톱주위전진피판을 이용한 재발성 내증식발톱의 교정)

  • Kim, Eui Sik;Kim, Sung Nam;Noh, Bok Kyun;Hwang, Jae Ha;Kim, Kwang Seog;Lee, Sam Yong
    • Archives of Plastic Surgery
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    • v.33 no.3
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    • pp.347-352
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    • 2006
  • Ingrowing toenail has been treated conventionally by various surgical treatment modlities. However, none of these procedures are perfect to achieve esthetic results with low cost, recurrence, and complication rates. Although mild cases can be treated conservatively, in severe recurrent cases, surgical treatment is preferred. The purpose of this study is to evaluate the effectiveness and safety of using partial matricectomy and paronychial advancement flap for correction of recurrent ingrowing toenail. Eight patients suffering from recurrent ingrowing toenail were operated using partial matricectomy and paronychial advancement flap in our department from August 2004 to August 2005. The number of recurrent episodes ranged from 2 to 5. With digital nerve block, the excision area was marked on nailplate and inflammed lateral nail fold. The horizontally designed paronychial flap considering defect size was effective for wide exposure of the neighboring germinal matrix, which is later to be completely excised or cauterized because remnant germinal matrix made postoperative spicule formation. The nailplate on the affected side was removed about 3-5 mm width longitudinally, being cautious not to damage the proximal dorsal nail fold. The same width of the sterile matrix including germinal matrix was excised longitudinally with inflammed granulation tissue and partial lateral nail fold on the affected side. The subcutaneously elevated paronychial flap was advanced to cover the defect and was anatomically sutured with 5-0 nylon sutures. We evaluated our procedure's effectiveness by examining some factors such as cosmetic results, recurrence, spicule formation, postoperative pain and duration of return to normal activities. In eight patients, no complication was observed such as recurrence, severe pain and spicule formation except for 1 case of infection. Postoperative discomfort was minimal. Average duration of return to normal activities was 12 days. Cosmetically the results were acceptable in all patients. The partial matricectomy and paronychial advancement flap for correction of recurrent ingrowing toenail were found to be technically simple, efficient procedure with a relative low recurrence rate and better cosmetic results.