• Corrosion Science and Technology
• /
• 제4권1호
• /
• pp.19-22
• /
• 2005

Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_2S$. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_{2}S$. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing $Na_{2}S$.

• 대한후두음성언어의학회지
• /
• 제26권2호
• /
• pp.97-100
• /
• 2015

Benign vocal fold lesions, such as vocal nodules, polyps and Reinke's edema, usually result from chronic voice overuse. Conservative management such as voice therapy and pharmacotherapy are used as the primary treatment techniques. The main purpose of voice therapy is to identify and reduce voice misuse to achieve the optimal voice. But complete resolution may not be possible in all patients after voice therapy. Furthermore, some patients with voice-related occupations, voice rest and voice therapy are sometimes difficult, which makes it hard to carry out the treatment. When conservative therapy is ineffective, laryngeal microsurgery can be performed under general anesthesia. However, potential complications following laryngeal suspension and violation of the layered structure of the vocal fold during surgery should be considered before surgery. In recent decades, emerging literatures have demonstrated the potential usefulness of vocal fold steroid injection as an alternative treatment option for benign vocal fold lesions. The most advantageous feature of vocal fold steroid injection is the maintenance of regional anti-inflammatory effects while preventing the potential systemic adverse effects of the steroid. Many non-surgical treatment methods can be conducted using different approaches in the office setting. It can be applied as an alternative treatment modality for the management of various benign vocal fold lesions.

• 대한한의학방제학회지
• /
• 제31권4호
• /
• pp.245-252
• /
• 2023

Objectives : The purpose of this study was to explore the compounds, targets and related diseases of garlic by the approaches of network pharmacology and bioinformatics in traditional chinese medicine. Methods : We investigated components and their target molecules of garlic using SymMap and TCMSP and they were compared with analysis platform. Results : 56 potential compounds were identified in garlic, 26 of which contained target information, and it was found that these 26 compounds and 154 targets interact with each other through a combination of 243 compounds. In addition, Apigenin was linked to the most targeted gene (78) in 26 compounds, followed by Kaempferol (61 genes), Nicotic Acid (14 genes), Geraniol (11 genes), Eee (10 genes), and Sobrol A (9 genes). Among 56 potential compounds, three compounds (Kaempferol, Dipterocarpol, and N-Methyl cytisine) corresponded to the active compound by screening criterion Absorption, Distribution, Metabolism, Excretion (ADME). In addition, 12 compounds in 56 potential compounds were associated with gastrointestinal (GI) motility disorder. Among them, Kaempferol was a compound that met the ADME parameters and the rest were potential compounds that did not meet. Also, Kaempferol was closely related to GI motility disorder, indicating that this Kaempferol could be a candidate for potential medical efficacy. Conclusions : It shows the relationship between the compound of garlic, an herbal supplement, and the biological process associated with GI motility disorder. These results are thought to help develop strategies for treating GI motility disorders.

• 한국학교ㆍ지역보건교육학회지
• /
• 제5권
• /
• pp.11-23
• /
• 2004

The purpose of this study was to analyze the internet usage patterns among adolescents and to provide basic data for the development of internet addiction prevention program. The subjects of this study were 1169 students in middle and high school students in Seoul, Korea. Self-administered questionnaires were employed and data were analysed by SPSS 12.0. Major conclusions were as follows: 1. Most of the students were found to be the normal internet users. On the other hand, potential risk group was 8.2% and high risk group was 4.7%. Every students have had an experience of inter use. The 90.6% of the students' households had internet links. The percentage of students who were using internet more than 3 hours a day was 25.7%, and The most popular type of website was entertainment. 2. Male students showed greater percentages of potential risk and high risk group than female students. The students having parents in divorce, remarriage and separation were more likely to be in potential risk group than those having normal parents. The staying alone in home after school and small sleeping time were positively related to high level of internet addiction. 3. The characteristics of the students in potential risk and high risk group were longer duration of the internet use, internet use through the whole week, frequent internet use late at night, frequent use of pornographic site, main purpose of internet use for entertainment and shortage of rest during internet use. This study results had an limitation of generalizing to entire Korean adolescents because the sample of this study was middle and high school students living in Seoul. Future study was needed for the analysis of internet use behavior of the entire Korean adolescents, and for the identification of the accurate predictors for adolescents' internet addiction.

• The Journal of Korean Physical Therapy
• /
• 제21권4호
• /
• pp.65-71
• /
• 2009

Purpose: Transcranial direct current stimulation (tDCS) is a useful method for modulating the brain activity. This study compared the effect of continuous and interrupted tDCS using the change in the movement related cortical potential. Methods: Thirty healthy participants (male: 18 and female: 12) were assigned randomly to three groups; sham tDCS, continuous tDCS, which the current continuously flowed for 10 minutes, and interrupted tDCS, which the interrupted current flowed for 10 minutes (repetition: 4sec stimulation and 5sec rest) at an intensity of 1mA with anodal polarity. The effect of tDCS on the right primary motor area was measured from the movement related cortical potential (MRCP) before and after the experiment. MRCP consisted of the bereitshaftspotential (BP) and negative slope potential (NS) at Cz and C4. Results: Continuous and interrupted tDCS showed a significant difference in the changes in the BP, NS at Cz and C4 compared to the sham tDCS. However, there was no significant difference between the continuous tDCS and interrupted tDCS. Conclusion: The change in cortical activity by continuous and interrupted tDCS results from an improvement in the MRCP. An interrupted tDCS may be a safe and useful modality for stimulating the cortical region.

• 대한인간공학회:학술대회논문집
• /
• 대한인간공학회 1997년도 춘계학술대회논문집
• /
• pp.165-175
• /
• 1997

Brain potential is described by using Euler Lagrange equation derived from Lagrangian based on SMNI(Statistical Mechanics of Neocortical Interaction). It is assumed that excitatory neuron firing is amplitude-modulated dominantly by the sum of two modes of frequency ${\omega}and 2 {\omega}$ . Time series of this neuron firing is numerically calculated. $I_{L}$related to low frequency distribution of power spectrum, $I_{H}$high frequency, and S(standard deviation) are introduced for the effective extraction of the dynamic property in this simulated brain potential. $I_{L}$,$I_{H}$, and S are obtained from EEG of 4 persons in rest state and are compared with thoretical results. It is of importance in various fields related to human well-being such as comfort-pursued industrial design, psychology, medicine to characterize human emotional states by EEG analysis. The pleasant and unpleasant sensation among various emotional states would be demonstrated to be determined in terms of ${\epsilon}$ and ${\gamma}$ parameters estimated by the simulated $I_{L}$-$I_{H}$-S relations.

• 대한의용생체공학회:의공학회지
• /
• 제39권1호
• /
• pp.16-21
• /
• 2018

In this study, we investigated the activity of Mirror Neuron System(MNS) and Steady State Visual Evoked Potential(SSVEP) according to frequency and duty rate of the flickering action video. Eight subjects were recruited for this study. The stimulus was consisted of a three-minute black and a flickering action video and they were repeatedly presented every six seconds. We used 50%, 75% of duty rate for each frequency 7.5 Hz and 15 Hz, and we also used the non-flickering condition and rest condition. As a result, the Mu suppression was the largest at 7. 5Hz and 50% duty rate and the SSVEP power was higher at 15 Hz than 7.5 Hz.

• 대한조선학회논문집
• /
• 제30권2호
• /
• pp.86-97
• /
• 1993

수치방법은 포텐셜 유동의 가정하에서 Semi-Lagrangian 기법을 사용하여 2차원 쇄기의 비선형운동과 축대칭 물체의 강제 상하동요 운동에 대해서 개발되었다. 2차원에서 Cauchy 이론은 경계를 따라서 복소포텐셜과 그것의 미분치를 계산하기 위해 적용되었고, 3차원에서 Rankinering 쏘오스가 사용되고 대수방정식을 풀기위해서 그린 제2정리를 이용하였다. 해는 완전한 사유표면 조건을 수치적분함으로서 시간전진시킨다. 수치계산 예는 정속도로 입수하는 쇄기형 주상체와 정지 상태로 부터 강제상하동요하는 문제를 택하였다. 쇄기입수 문제는 Chapman [4], Kim[11]의 계산결과와 비교된다. 위에서 적용된 기법을 이용하여 구한 시간영역에서 힘을 Fourier 변환함으로서 부가질량계수, 감쇄계수, 2차조화력등이 얻어지고 Yamashita[5]의 실험치와 비교된다.

• 천문학회지
• /
• 제19권1호
• /
• pp.33-49
• /
• 1986

Radial distribution of internal density has been determined for thirteen subclouds in the three giant molecular cloud complexes accompanying Mon OB1, Mon OB2 and CMa OB1 associations, We modeled their radial density structures with the density distribution of isothermal gas spheres. Most of the subclouds, nine out of the thirteen, are well described by isothermal spheres of single component; while the rest four require an additional component. Total mass and potential energy of each subcloud are also derived from the radial density structure; thermal energy and internal velocity dispersion required for sustaining the density structure are deduced from the isothermal gas model. Our derived masses of the clouds are comparable to the values determined by Blitz (1978) under LTE assumption. This agreement suggests that the correction factor for non-LTE effect on mass-estimate is not far from unity. The ratio of the gravitational potential energy to the kinetic energy of thermal motion is as large as 250; hence the thermal motion alone cannot support these clouds against the gravity. Being supported by turbulence motion with velocities of six to seven times the thermal velocity, the clouds of one-component type seem to be in equilibrium with the gravity; while the clouds of two-component type are likely to be in the stage of gravitational collapse.

• Natural Product Sciences
• /
• 제8권4호
• /
• pp.165-169
• /
• 2002

One-hundred and twenty plant extracts were prepared from 29 Indonesian plants and were primarily tested in vitro cytotoxicity in cultured human lung (A549), colon (Col2), and stomach (SNU-638) cancer cells. As a result, the 23 extracts were found to be active in the criteria of $ED_{50}$<$20\;{\mu}g/ml$. Remarkable cytotoxicity was observed for chloroform and n-butanol extracts of Calotropis gigantea, with $ED_{50}$ values ranging from 0.25 to $0.46\;{\mu}g/ml$. Five extracts derived from Eclipta alba and Excoecaria cochinchinensis displayed potent cell-line selective cytotoxicity, while the rest of 15 extracts showed modest cytotoxic activity against all of three cancer cells. In addition, the cytotoxic potential of subfractions of Zingiber cassumunar against a panel of human cancer cell lines is presented.