• Toxicological Research
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• v.24 no.1
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• pp.45-49
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• 2008

Formaldehyde has been identified as the most prevalent cause of sick building syndrome (SBS), which has become a major social problem, especially in developing urban areas. However, studies on the molecular mechanisms associated with formaldehyde toxicity have been limited, probably because it is difficult to relate the experimental results obtained from in vitro studies to human exposure in vivo. Using polymerase chain reaction-based suppression subtractive hybridization, we recently identified 27 different formaldehyde-inducible genes including platelet-derived growth factor receptor alpha gene (PDGFRA) and mouse double minute 2 (MDM2) gene which were increased significantly in both formaldehyde-exposed human trachea cells, 680.Tr, and rat tracheas. To establish a possible relationship between induction of these formaldehyde-inducible genes and symptoms of SBS, we examined expression levels of these genes in peripheral lymphocytes of residents of new apartments. Here, we report that the expression of PDGFRA and MDM2 transcripts was significantly higher in peripheral blood lymphocytes obtained from 15 residents in new buildings than in seven control individuals. Our results suggest that the elevated levels of PDGFRA and MDM2 may be associated with the formaldehyde-induced pathophysiology that is closely related with SBS, and that they deserve evaluation as potential biomarkers for formaldehyde intoxication.

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.135-145
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• 2008

The study was aimed at evaluating the antioxidant and free radical scavenging activities of ethanolic extract and its fractions of Cleome rutidosperma. The antioxidant activity, reducing power, total phenolic content, total flavonoid content, superoxide anion scavenging activity, nitric oxide anion scavenging activity, in vitro antilipid peroxidation activity and in vitro non-enzymatic hemoglobin glycosylation were studied. The results obtained in the study indicate that Cleome rutidosperma is a potential source of natural antioxidant. All the parameters were found to be concentration dependent and increased with increasing amounts of sample. Flavonoids, phenolic compound like tannins, terpenoids may be responsible for the antioxidant activity of the plant. Variation of solubility parameters in various models may be attributed to non-linearity of activity of ethanol extract fractions models. Further investigation on the isolation and identification of antioxidant component(s) in the plant may lead to chemical entities with potential for clinical use.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.763-770
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• 2014

The effect of $CO_2$ on the opening of stomata in the intact leaf of Commelina communis has been investigated. Full opening of stomatal apertures(around $18{\mu}m$) was achieved in the intact leaf by addition of $CO_2$($900{\mu}mol\;mol^{-1}$). At 90 minutes, the stomatal apertures of leaves treated with $CO_2$ free air were reduced. In contrast, stomata opened most widely with the treatment of $CO_2$ air at 90 minutes. The effects of light, $CO_2$ air and $CO_2$ free air on the change of membrane potential difference(PD) were measured. Fast hyperpolarization of guard cell membrane PD was recorded reaching up to -12 mV in response to light. If $CO_2$ free air was given firstly, there was no response. When light was given after $CO_2$ free air, the light effect was very clear. At the onset of $CO_2$ air, the PD showed a dramatic hyperpolarization to about -25 mV. Changes in the pH of apoplast in intact leaves in response to $CO_2$ air were observed. $CO_2$ air caused a change of 0.4 pH unit. Therefore, it can be hypothesized that $CO_2$ flowing could stimulate proton efflux which is a necessary precursor of stomatal opening.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1259-1264
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• 2011

This paper suggests a new film-type haptic actuator based on cellulose acetate electro-active paper. Conventional tiny haptic actuators in mobile devices can create vibrotactile sensation at only near resonant frequency. The strategy of operating near the resonant frequency, however, brought a new issue for creating vibrotactile sensation which can be strong enough to feel in arbitrary frequency. Another problem is that the size of the conventional actuator is not small enough to be embedded into slim mobile devices. In order to achieve these issues, we propose a thin and tiny actuator based on a cellulose acetate material charged with an electric potential. The motion of the actuator can be a concave or a convex by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential.

• Annals of Clinical Neurophysiology
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• v.20 no.2
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• pp.66-70
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• 2018

Electrodiagnostic studies such as nerve conduction studies (NCS) and needle electromyography (EMG) provide important and complementary information for evaluating patients with suspected neuromuscular disorders. NCS and needle EMG are reasonably safe diagnostic investigations and are generally associated with only mild transient discomfort when performed by experienced physicians. However, there is the risk of complications in some patients, because NCS involve the administration of electric current and EMG involves inserting a needle percutaneously into muscle tissue. This article reviews the potential risks of NCS and needle EMG.

• English Language & Literature Teaching
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• v.15 no.3
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• pp.151-170
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• 2009

Recently speech texts have been increasingly used for English education because of their various advantages as language teaching and learning materials. The purpose of this paper is to analyze speech texts in a corpus-based lexical approach, and suggest some productive methods which utilize English speaking or writing as the main resource for the course, along with introducing the actual classroom adaptations. First, this study shows that a speech corpus has some unique features such as different selections of pronouns, nouns, and lexical chunks in comparison to a general corpus. Next, from a collocational perspective, the study demonstrates that the speech corpus consists of a wide variety of collocations and lexical chunks which a number of linguists describe (Lewis, 1997; McCarthy, 1990; Willis, 1990). In other words, the speech corpus suggests that speech texts not only have considerable lexical potential that could be exploited to facilitate chunk-learning, but also that learners are not very likely to unlock this potential autonomously. Based on this result, teachers can develop a learners' corpus and use it by chunking the speech text. This new approach of adapting speech samples as important materials for college students' speaking or writing ability should be implemented as shown in samplers. Finally, to foster learner's productive skills more communicatively, a few practical suggestions are made such as chunking and windowing chunks of speech and presentation, and the pedagogical implications are discussed.

• Structural Engineering and Mechanics
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• v.57 no.6
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• pp.1015-1038
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• 2016

In the current research an advanced criterion with non-associated flow rule (non-AFR) for depicting the behavior of anisotropic sheet metals is presented to consider the strength differential effects (SDEs) for these materials. Owing to the fact that Lou et al. (2013) yield function is dependent on structure of an anisotropic material (BCC, FCC and HCP), an advanced yield function with inspiring of Yoon et al. (2014) yield function is proposed which is dependent upon anisotropic structures. Furthermore, to compute Lankford coefficients, a new pressure sensitive plastic potential function which would be dependent to anisotropic structure is presented and coupled with the proposed yield function with employing a non-AFR in a novel criterion which is called here 'dvanced criterion'. Totally eighteen experimental data are required to calibrate the criterion contained of directional tensile and compressive yield stresses for the yield function and directional Lankford coefficients for the plastic potential function. To verify the criterion, three anisotropic sheet metals with different structures are taken as case studies such as Al 2008-T4 (a BCC material), Al 2090-T3 (a FCC material) and AZ31 (a HCP material).

• The Korean Journal of Pain
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• v.19 no.2
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• pp.164-167
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• 2006

Background: There have been an increasing number of reports about infection-related complications after epidural block, and the analysis of these previous reports may offer valuable information for the prevention and treatment of such complications. Methods: We searched for complications about infection that was related to epidural blockade procedures by using the Medline Search program. We analyzed the types of infection-related complications as well as the potential risk factors, the time course from symptom development to treatment, the causative organisms and the treatment outcomes. Results: Seventeen cases were identified. The types of complications were epidural abscess, subdural abscess, spinal arachnoiditis, bacterial meningitis and aseptic meningitis. Five patients received a single block and twelve patients received a continuous block with catheterization. The most common site of epidural catheterization was the lumbar area and eight patients had indwelling catheters for less than fifteen days. Eight patients had a diabetes mellitus as a risk factor and fourteen patients showed less than seven days from the development of symptoms to treatment. Eleven patients received laminectomy and intravenous antibiotics as a treatment and eight patients had full recovery without neurological deficit. Conclusions: Early diagnosis and treatment is essential for the favorable outcome of infection-related complication after epidural block. In addition, absolute sterile technique should always be performed and patient education concerning these potential complications must be accompanied.

• Environmental and Resource Economics Review
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• v.22 no.1
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• pp.3-29
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• 2013

The purpose of this study is to estimate consumer preferences on hybrid cars and electric cars by employing a choice experiment reflecting the various market conditions, such as different projected market shares of green vehicles and $CO_2$ emission regulations. Depending on different market scenarios, we examine as to which attribute and individual characteristic affect the preferences of potential consumers on green vehicles and further, forecast the potential market shares of green cars. The primary results, estimated by a conditional logit and panel probit models, indicate that sales price, fuel cost, maximum speed, emission of air pollutants, fuel economy, and distance between fuel stations can significantly affect consumer's choice of environment-friendly cars. The second finding is that the unique features of electric cars might better appeal to consumers as the market conditions for electric cars are improved. Third, education, age, and gender can significantly affect individual preferences. Finally, as the market conditions become more favorable toward green cars, the forecasted market shares of hybrid and electric vehicles will increase up to 67% and 14%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.562-564
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• 2002

In recent years, environments of our globe has been getting worse as a result of rapid growth of socioeconomic activities. The global environmental issues of acid rain, green house effect and ozone depletion are caused by various chemical pollutants, emitted from industries, automobiles and home. Most of these pollutants are produced by combustion processes. CO2 as a chief criminal of the greenhouse effect is a main combustion product of fossil fuels. Development of solid-state electrochemical devices for detecting CO2 is demonstrated based on various combination of solid electrolytes and auxiliary sensing materials. The object of this research is to develop various sensor performance for solid electrolyte gas sensor, and to test gas sensor performance manufactured. So we try to present a guidance for developing potential type gas sensor. We concentrated on development of manufacturing process and performance test.