http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Acute and Subchronic Inhalation Toxicity of n-Octane in Rats
Sung, Jae-Hyuck,Choi, Byung-Gil,Kim, Hyeon-Yeong,Baek, Min-Won,Ryu, Hyun-Youl,Kim, Yong-Soon,Choi, Young-Kuk,Yu, Il-Je,Song, Kyung-Seuk Occupational Safety and Health Research Institute 2010 Safety and health at work Vol.1 No.2
Objectives: We have investigated the toxic effects of the inhalation of subchronic and acute levels of n-octane. Methods: The rats were exposed to n-octane of 0, 2.34, 11.68 and 23.36 mg/L (n = 5 rats/group/gender) in an acute inhalation test (Organization for Economic Co-operation and Development (OECD) TG 403), or to 0, 0.93, 2.62 and 7.48 mg/L (n = 10 rats/group/gender) for a subchronic inhalation test (OECE TG 413), to establish a national chemical management system consistent with the Globally Harmonized Classification System (GHS). Results: Acutely-exposed rats became lethargic but recovered following discontinuation of inhalation. Other clinical symptoms such as change of body weight and autopsy finds were absent. The LC50 for the acute inhalation toxicity of n-octane was determined to exceed 23.36 mg/L and the GHS category was 'not grouping'. Subchronically-treated rats displayed no significant clinical and histopathological differences from untreated controls; also, target organs were affected hematologically, biochemically and pathologically. Therefore, the no observable adverse effect level was indicated as exceeding 7.48 mg/L and the GHS category was 'not grouping' for the specific target organ toxicity upon repeated exposure. Conclusion: However, n-octane exposure should be controlled to be below the American Conference of Industrial Hygienists recommendation (300 ppm) to prevent inhalation-related adverse health effects of workers.
Choi, Jin Bong,Yoon, Byung Il,Kim, Su Jin,Cho, Hyuk Jin,Hong, Sung-Hoo,Choi, Yeong Jin,Kim, Sae Woong,Hwang, Tae-Kon,Lee, Ji Youl 대한비뇨기과학회 2011 Investigative and Clinical Urology Vol.52 No.2
<P><B>Purpose</B></P><P>We examined changes in the clinicopathologic characteristics of renal cell carcinoma (RCC) in the past 25 years and aimed to obtain indicators for its diagnosis and treatment.</P><P><B>Materials and Methods</B></P><P>The medical records of 563 patients with confirmed primary RCC after surgical treatment from 1985 to 2010 at Seoul St. Mary's Hospital were retrospectively reviewed. Patient and tumor characteristics were compared over 3 time periods (period 1: 1985-1994, period 2: 1995-2004, period 3: 2005-2010).</P><P><B>Results</B></P><P>Period 1 included 65 patients, period 2 included 183 patients, and period 3 included 315 patients, showing an exponential growth in the number of patients. Frequency was highest in the late 50s age group. The review of clinical symptoms showed that incidental diagnosis increased significantly. The tumor size at diagnosis gradually decreased and the proportion of small tumors less than 4 cm increased remarkably. Concerning tumor spread, organ-confined tumors (T<SUB>1-2</SUB>N<SUB>0</SUB>M<SUB>0</SUB>) increased and distant metastasis decreased. Histologically, the clear cell type made up the greatest proportion, about 90% in each period, but subtypes besides the clear cell type increased over the study period. The rate of nephron-sparing surgery increased, and exophytic masses were the most common.</P><P><B>Conclusions</B></P><P>Our review of the recent 25 year's worth of data on RCC from Seoul St. Mary's Hospital showed that the incidental diagnosis of RCC increased over the study period in accordance with the development of screening tests. Tumor size decreased in accordance with the progress in imaging modalities. In the future, multicenter research will be needed to analyze the characteristics of whole renal cancer in Korea.</P>
Choi, Jaeho,Park, Sung-Kyun,Hwang, Ho-Young,Huh, Joo-Youl Elsevier 2015 Acta materialia Vol.84 No.-
<P><B>Abstract</B></P> <P>An extended Cahn–Hilliard model (ECHM) was compared with the conventional phase-field model (CPFM) for simulating the operating state of a dendrite tip during the two-dimensional solidification of pure undercooled melts over a wide range of interfacial energy anisotropy. ECHM differs from CPFM in terms of how interfacial energy anisotropy is introduced. In ECHM, anisotropy comes solely from the anisotropic nature of the fourth-rank tensor terms included in free energy density, and not from assuming an orientation-dependent gradient energy coefficient <I>ɛ</I>(<I>θ</I>), which is the case in CPFM. ECHM resulted in dendrites growing with a rounded tip, even when anisotropy (<I>δ</I>) was greater than its critical value (<I>δ<SUB>c</SUB> </I>), but the tip radius at large anisotropy (<I>δ</I> ⩾ <I>δ<SUB>c</SUB> </I>) was limited by the interface width. In contrast to CPFM, ECHM did not engender an anomalous increase in the tip radius with bulk undercooling at small anisotropy (<I>δ</I> < <I>δ<SUB>c</SUB> </I>). In the simulation by ECHM, the tip velocity increased continuously with increasing <I>δ</I> beyond <I>δ<SUB>c</SUB> </I>. When compared in terms of the selection parameter <I>σ</I> <SUP>∗</SUP> of the dendrite tip, data obtained from ECHM fitted better to the <I>σ</I> <SUP>∗</SUP> ∝ <I>δ</I> <SUP>7/4</SUP> relationship over a wider range of <I>δ</I> than those obtained from CPFM. The present comparative study suggests that ECHM hinders the transition of the dendritic growth kinetics from diffusion-limited to interface-kinetic-limited, which occurs in the case of CPFM as the tip velocity increases with an increase in either undercooling or anisotropy.</P>
Choi, Min-Ki,Sung, Youl-Moon,Park, Min-Woo American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.2
<P>We report a TiO2 nanotubes (NTs)-based Electrochemical luminescence (ECL) cell. The ECL cell was fabricated using the electrode of TiO2 NTs and Ru(II) complex (Ru(bpy)2+(3)) as a luminescence materials. The fabricated ECL cell is composed of F-doped SnO2 (FTO) glass/Ru(II)/TiO2 NTs/Ti plate. At a bias voltage of 3 V, the measured ECL efficiencies were 0 Im/W for cell without NTs, 0.03 Im/W for NTs-6.5 µm, 0.07 Im/W for NTs-8 µm and 0.1 Im/W for NTs-10 µm, respectively. The use of Ti02 NTs increases ECL intensities by about 2 times compared to the typical ECL cell without the use of TiO2 NTs.</P>
Role of Nitric Oxide in Pepsinogen Secretion from Rat Gastric Chief Cells
SUNG, Dae Suk,SEO, Dong Wan,CHOI, Don Woong,AHN, Seong Hoon,HONG, Sung Youl,LEE, Hoi Young,HAN, Jeung Whan,LEE, Hyang Woo 성균관대학교 약학연구소 1999 成均藥硏論文集 Vol.11 No.-
Abstract-Nitric oxide (NO), a cellular messenger synthesized from L-arginine by NO synthase (NOS, EC.1.14.13.39), is considered to be a regulator of gastric secretion. In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat gastric chief cells. Treatment of chief cells with carbachol resulted in an increase in the arginine conversion to citrulline, the amount of NO_X, the release of pepsinogen, and the level of cGMP. Especially, carbachol-stimulated increase of arginine to citrulline transformation, the amount of NO_X, cGMP level and the release of pepsinogen were partially reduced by the natural NOS inhibitor, N^G-monomethyl-L-arginine (MMA) and N^G,N^G-dimethyl-L-arginine (DMA). Furthermore, MMA-and DMA-induced decrease of pepsinogen secretion showed dose-dependent pattern. Activation of NOS is one of the early events in receptor-mediated cascade of reactions in gastric chief cells and NO, not completely, but partially mediates gastric secretion. Agonist-stimulated pepsinogen secretion in chief cells has been considered to be mediated in adenosine 3',5'-cyclic monophosphate pathway and/or guanosine 3',5'-cyclic monophosphate (cGMP) pathway. Taken together, the above results suggest that partial decrease of exocrine secretion following treatment of NOS inhibitor may result from the inactivation of NOS and subsequent guanylate cyclase, and NO/cGMP pathway may play a pivotal role in exocrine secretion.
Choi, Woo-Jin,Kwak, Dong-Joo,Park, Cha-Soo,Sung, Youl-Moon American Scientific Publishers 2012 Journal of nanoscience and nanotechnology Vol.12 No.4
<P>Transparent conductive In(2-x)Sn(x)O3 (ITO) and In(2-x)Ti(x)O3 (ITiO) films were prepared via RF magnetron sputtering on soda-lime glass substrates at 300 degrees C and investigated with respect to their photoelectric conversion performance compared with the commercial F:SnO2 (FTO) glass. The near infrared ray transmittance of ITiO was highest for wavelengths over 1000 nm compared with those of ITO and FTO. Photoelectrochemical cells (PECs) were fabricated using ITiO film, ITO film, and FTO glass. The photoelectric conversion efficiency (eta) of the PECs samples using ITiO was 5.64%, whereas 2.73% was obtained from the PEC samples with ITO, both at 100 mW/cm2 light intensity. The impedance measurement was also used to explain the electrochemical performance of the PECs with various TCO glasses.</P>
Acupuncture for anxiety : A protocol for a systematic review of controlled trials
Choi, Sung-Youl,Kim, Geun-Woo Williams & Wilkins Co 2018 Medicine Vol.97 No.14
<P><B>Abstract</B></P><P><B>Background:</B></P><P>Acupuncture has been widely, used in Asian countries since the Yuan Dynasty in China. Moreover, acupuncture has been reported to exhibit anti-allergy effects in many clinical trials. This systematic review will assess the effectiveness, and safety of acupuncture for anxiety treatment.</P><P><B>Methods:</B></P><P>Eleven databases, including Asian databases, will be searched for studies conducted through December in the year 2017. We will include randomized controlled trials (RCTs) assessing acupuncture for anxiety. The risk of bias will be evaluated using the Cochrane risk of bias assessment tool, and confidence in the cumulative evidence will be evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) instrument.</P><P><B>Ethics and dissemination:</B></P><P>This systematic review will be published in a peer-reviewed journal. It will also be disseminated electronically, and in print. The review will be updated to inform, and guide healthcare practices.</P><P><B>Registration number:</B></P><P>PROSPERO 2018 under number CRD42018080034.</P>