초음파 주파수 및 반응조건 변화에 따른 나프탈렌 분해효율과 OH 라디칼의 발생량 비교

박종성(Jong Sung Park),박소영(So Young Park),오재일(Jei Ll Oh),정상조(Sang Jo Jeong),이민주(Min Ju Lee),허남국(Nam Guk Her) 大韓環境工學會 2009 대한환경공학회지 Vol.31 No.2

나프탈렌은 휘발성이 있는 소수성 물질로 발암유발 가능성이 있고, 수생태계에 심각한 영향을 미친다. 본 연구는 초음파의 주파수 및 반응조건별 나프탈렌 분해효율과 OH 라디칼 변화량을 조사하였다. C-18 역상칼럼을 이용한 LC/FLD (1200 series, Agilent)로 나프탈렌을 분석한 결과 MDL (Method detection limit)은 0.01 ppm이었다. 초음파 조사 동안 휘발된 나프탈렌은 거의 검출되지 않았고(0.05 ppm 이하), 반응조 덮개 개폐별 나프탈렌 분해효율은 거의 차이를 보이지 않았다(1% 이내). 초음파 반응온도가 증가할수록 나프탈렌 제거효율은 감소하는 경향(15℃: 95%→40℃: 85%)을 보였고, pH가 낮을수록 나프탈렌 분해효율이 증가(pH 12: 84%→pH 3: 95.6%)하였다. 나프탈렌 초기농도의 감소에 따라 반응속도는 증가하는 경향을 보여주었다(2.5 ppm: 27.3×10(-3) min(-1), 5 ppm: 22.7×10(-3) min(-1), 10 ppm: 19.0×10(-3) min(-1)). 동일한 초음파 조건(2.5 ppm 나프탈렌, 0.075 W/mL, 20℃, pH 6.8)에서 28 kHz의 분해효율이 132 kHz보다 약 1.46배 높았고(132 kHz: 56%, 28 kHz: 82.7%), 유사 일차반응 속도상수(k1)도 약 2.3배 높게 나타났다(132 kHz: 2.4×10(-3) min(-1), 28 kHz: 5.0×10(-3) min(-1)). 초음파 조사 10분 후 H₂O₂ 농도는 132 kHz가 28 kHz보다 약 7.2배 높았지만(132 kHz: 0.36 ppm, 28 kHz: 0.05 ppm), 조사 90분 후에는 28 kHz가 132 kHz보다 1.1배 높았다(28 kHz: 0.45 ppm, 132 kHz: 0.4 ppm). 2.5 ppm 나프탈렌 용액에 132 kHz와 28 kHz 초음파 조사시 발생된 H₂O₂ 농도는 초순수에 초음파 조사한 결과보다 각각 0.1 ppm과 0.05 ppm씩 낮게 나타났다. 혼형(24 kHz)과 배스형(28 kHz) 초음파의 나프탈렌 분해효율은 각각 87%와 82.7%였고, k1은 22.8×10(-3) min(-1)와 18.7×10(-3) min(-1)로 산출되었다. 다주파 복합형 초음파 시스템(28 kHz 배스형+24 kHz 혼형 초음파)의 나프탈렌 분해효율은 단일주파수 24 kHz(혼형)와 비슷한 제거효율을 보였으나(88%), H₂O₂의 농도는 약 3.5배 높게 조사되었다(28 kHz+24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm). 이와 같은 다주파 복합형 초음파 시스템은 OH 라디칼에 의해 산화가 잘 일어나는 물질의 분해에 매우 효과적으로 적용될 수 있을 것으로 예상된다. Naphthalene is a volatile, hydrophobic, and possibly carcinogenic compound that is known to have a severe detrimental effect to aquatic ecosystem. Our research examined the effects of various operating conditions (temperature, pH, initial concentration, and frequency and type of ultrasound) on the sonochemical degradation of naphthalene and OH radical production. The MDL (Method detection limit) determined by LC/FLD (1200 series, Agilient) using C-18 reversed column is measured up to 0.01 ppm. Naphthalene vapor produced from ultrasound irradiation was detected under 0.05 ppm. Comparison of naphthalene sonodegradion efficiency tested under open and closed reactor cover fell within less than 1% of difference. Increasing the reaction temperature from 15℃ to 40℃ resulted in reduction of naphthalene degradation efficiency (15℃: 95%→40℃: 85%), and altering pH from 12 to 3 increased the effect (pH 12: 84%→pH 3: 95.6%). Pseudo first-order constants (k1) of sonodegradation of naphthalene decreased as initial concentration of naphthalene increased (2.5 ppm: 27.3×10(-3) min(-3)→10 ppm : 19.0×10(-3) min(-3)). Degradation efficiency of 2.5 ppm of naphthalene subjected to 28 kHz of ultrasonic irradiation was found to be 1.46 times as much as when exposed under 132 kHz (132 kHz: 56%, 28 kHz: 82.7%). Additionally, its k1 constant was increased by 2.3 times (132 kHz: 2.4×10(-3) min(-1), 28 kHz: 5.0×10(-3) min(-1)). H₂O₂ concentration measured 10 minutes after the exposure to 132 kHz of ultrasound, when compared with the measurement under frequency of 28 kHz, was 7.2 times as much. The concentration measured after 90 minutes, however, showed the difference of only 10%. (concentration of H₂O₂ under 28 kHz being 1.1 times greater than that under 132 kHz.) The H₂O₂ concentration resulting from 2.5 ppm naphthalene after 90 minutes of sonication at 24 kHz and 132 kHz were lower by 0.05 and 0.1 ppm, respectively, than the concentration measured from the irradiated M.Q. water (no naphthalene added.) Degradation efficiency of horn type (24 kHz) and bath type (28 kHz) ultrasound was found to be 87% and 82.7%, respectively, and k1 was calculated into 22.8×10(-3) min(-1) and 18.7×10(-3) min(-1), respectively. Using the multi- frequency and mixed type of ultrasound system (28 kHz bath type+24 kHz horn type) simultaneously resulted in combined efficiency of 88.1%, while H₂O₂ concentration increased 3.5 times (28 kHz+24 kHz: 2.37 ppm, 24 kHz: 0.7 ppm.) Therefore, the multi-frequency and mixed type of ultrasound system procedure might be most effectively used for removing the substances that are easily oxidized by the OH radical.

Risk Factors of Mortality for Burkholderia cepacia Bacteremia in a Tertiary Hospital (초)

( Nam Su Ku ),( Ji Hyeon Baek ),( Yun Tae Chae ),( Su Jin Jeong ),( Sung Jun Jin ),( Sang Hoon Han ),( Chang Oh Kim ),( Jun Yong Choi ),( Young Goo Song ),( June Myung Kim ) 대한내과학회 2010 대한내과학회 추계학술대회 Vol.2010 No.-

Analysis of Liquid Oxygen Feeding System for Pump-Fed Liquid Propulsion Rocket

Nam-Kyung Cho,Oh-Sung Kwon,In-Hyun Cho,Young-Mog Kim 한국추진공학회 2004 한국추진공학회 학술대회논문집 Vol.2004 No.5

A Winged-Helix Transcription Factor Foxg1 Induces Expression of Mss4 Gene in Rat Hippocampal Progenitor Cells

Nam, Ju-Suk,Yang, Haijie,Kim, Nam-Ho,Sun, Yuanjie,Choi, Byung-Soo,Huh, Sung-Oh The Korean Society for Brain and Neural Science 2010 Experimental Neurobiology Vol.19 No.2

<P>Foxg1 (previously named BF1) is a winged-helix transcription factor with restricted expression pattern in the telencephalic neuroepithelium of the neural tube and in the anterior half of the developing optic vesicle. Previous studies have shown that the targeted disruption of the Foxg1 gene leads to hypoplasia of the cerebral hemispheres with severe defect in the structures of the ventral telencephalon. To further investigate the molecular mechanisms by which Foxg1 plays essential roles during brain development, we have adopted a strategy to isolate genes whose expression changes immediately after introduction of Foxg1 in cultured neural precursor cell line, HiB5. Here, we report that seventeen genes were isolated by ordered differential displays that are up-regulated by over-expression of Foxg1, in cultured neuronal precursor cells. By nucleotide sequence comparison to known genes in the GeneBank database, we find that nine of these clones represent novel genes whose DNA sequences have not been reported. The results suggest that these genes are closely related to developmental regulation of Foxg1.</P>

Fabrication of High Critical Current SmBCO Coated Conductors Using Co-evaporation

Sang-Soo OH,Ho-Sup KIM,Hong-Soo HA,Rock-Kil KO,Nam-Jin LEE,Seung-Hyun MOON 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

A Case of Bernard-Soulier Syndrome Associated with 22q11.2 Deletion Syndrome

Oh Cheol Kwon,Su Hyun Yoon,Sung Han Kang,Hyery Kim,Kyung-Nam Koh,Ho Joon Im 대한소아혈액종양학회 2023 Clinical Pediatric Hematology-Oncology Vol.30 No.2

22q11.2 deletion syndrome (22q11.2DS) is a disorder caused by microdeletions in the long arm of chromosome 22. It is one of the most common chromosomal micro-deletion disorders. Clinical symptoms are caused by heterozygous deletion of chro-mosome 22q11.2 and include congenital heart diseases and palatal abnormalities. Bernard-Soulier syndrome (BSS) is a rare autosomal recessive bleeding disorder caused by deficiency of the glycoprotein Ib-IX-V complex (GPIb-IX-V), the receptor for von Willebrand factor. Glycoprotein Ib-beta (GPIbβ) gene mutation is one of the causes of BSS, and the GP1bβ gene is located on chromosome 22q11.2. Most 22q11DS patients do not have a bleeding issue since most of them have heterozygous deletion of the GPIbβ gene. However, we report a case in which a child with 22q11.2DS visited the hospital with subgaleal hemorrhage and was diagnosed with Bernard-Soulier syn-drome with GPIbβ gene mutation by a platelet aggregation test and genetic sequencing.

Comparison of the Diagnostic Ability of Endoscopic Ultrasonography and Abdominopelvic Computed Tomography in the Diagnosis of Gastric Subepithelial Tumors

Sang Yoon Kim,Ki-Nam Shim,Joo-Ho Lee,Ji Young Lim,Tae Oh Kim,A. Reum Choe,Chung Hyun Tae,Hye-Kyung Jung,Chang Mo Moon,Seong-Eun Kim,Sung-Ae Jung 대한소화기내시경학회 2019 Clinical Endoscopy Vol.52 No.6

Background/Aims: Endoscopic ultrasonography (EUS) is the most effcient imaging modality for gastric subepithelial tumors (SETs). However, abdominopelvic computed tomography (APCT) has other advantages in evaluating the characteristics, local extension,or invasion of SETs to adjacent organs. This study aimed to compare the diagnostic ability of EUS and APCT based on surgicalhistopathology results. Methods: We retrospectively reviewed data from 53 patients who underwent both EUS and APCT before laparoscopic wedge resectionfor gastric SETs from January 2010 to December 2017 at a single institution. On the basis of histopathology results, we assessed thediagnostic ability of the 2 tests. Results: The overall accuracy of EUS and APCT was 64.2% and 50.9%, respectively. In particular, the accuracy of EUS vs. APCT for thediagnosis of gastrointestinal stromal tumors (GISTs), leiomyomas, and ectopic pancreas was 83.9% vs. 74.2%, 37.5% vs. 0.0%, and 57.1%vs. 14.3%, respectively. Most of the incorrect diagnoses with EUS involved hypoechoic lesions originating in the fourth echolayer, withthe most common misdiagnosed lesions being GISTs mistaken for leiomyomas and vice versa. Conclusions: APCT showed a lower overall accuracy than EUS; however, APCT remains a useful modality for malignant/potentiallymalignant gastric SETs.

Cilostazol Improves HFD-Induced Hepatic Steatosis by Upregulating Hepatic STAMP2 Expression through AMPK

Oh, Yoo Jin,Kim, Hye Young,Lee, Mi Hwa,Suh, Sung Hwan,Choi, Yongmun,Nam, Tae-gyu,Kwon, Woo Young,Lee, Sang Yeob,Yoo, Young Hyun American Society for Pharmacology and Experimental 2018 Molecular pharmacology Vol.94 No.6

<P>Nonalcoholic fatty liver disease (NAFLD) is an increasingly studied condition that can progress to end-stage liver disease. Although NAFLD was first described in 1980, a complete understanding of the mechanism and causes of this disease is still lacking. Six-transmembrane protein of prostate 2 (STAMP2) plays a role in integrating inflammatory and nutritional signals with metabolism. Our previous study suggested that STAMP2 may be a suitable target for treating NAFLD. In the current study, we performed a focused drug-screening and found that cilostazol could be a potential STAMP2 enhancer. Thus, we examined whether cilostazol alleviates NAFLD through STAMP2. The in vivo and in vitro pharmacological efficacies of cilostazol on STAMP2 expression and lipid accumulation were analyzed in NAFLD mice induced by high-fat diet (HFD) and in HepG2 cell lines treated by oleic acid (OA), respectively. Cilostazol increased the expression of STAMP2 through transcriptional regulation in vivo and in vitro. Cilostazol also dampened the STAMP2 downregulation caused by the HFD and by OA in vivo and in vitro, respectively. Cilostazol activated AMP-activated protein kinase (AMPK) in vivo and in vitro, and AMPK functions upstream of STAMP2, and reversed downregulation of STAMP2 expression through AMPK in the NAFLD model. Cilostazol ameliorates hepatic steatosis by enhancing hepatic STAMP2 expression through AMPK. Enhancing STAMP2 expression with cilostazol represents a potential therapeutic avenue for treatment of NAFLD.</P><P>[Figure]</P>

Effect of Capsaicin and Its Derivative on the Voltage Dependent Ca^2+ Currents in Spinal Dorsal Root and Trigeminal Ganglion Neurons

Oh, Seog Bae,Yoon, Chan Song,Nam, Sang Chae,Park, Kyungpyo,Lee, Jong-Heun,Kim, Joong-Soo Korean Academy of Oral Biology and the UCLA Dental 1997 International Journal of Oral Biology Vol.22 No.4

Capsaicin produces initial irritation followed by insensitivity to noxious stimuli. It can not be easily used in clinical pain control due to its toxic effects. Recently, a capsaicin derivative (KR) was developed to use as an analgesic with fewer toxic effects. However, the mechanism of action and clinical effects of KR are not well understood. In this experiment we tried to explore the cellular mechanisms of the analgesic effect induced by capsaicin and KR in DRG or TG neurons. The DRG and TG neurons were acutely isolated into single neuronal cells from neonatal or adult rats with trypsin treatment and mechanical trituration. Voltage dependent calcium currents were measured with whole-cell patch clamp configuration in small diameter sensory neurons (between 10 μm and 20μm). On the basis of activation threshold, Ca^2+ currents of DRG and TG neurons were classified as LVA (T-type) and HVA I_ca. HVA I_ca were subclassified into L-type and N-type. The amplitude of L-type calcium current was remarkably inhibited by application of 1 μM KR in DRG. The inhibition of calcium current recovered significantly at five minutes after application of KR. In most capsaicin-sensitive neurons in TG, capsaicin irreversibly inhibited voltage dependent calcium currents. Capsaicin and KR-induced inhibition of voltage dependent calcium currents would be expected to reduce neurotransmitter release from both central and peripheral terminals of the sensitive primary sensory neurons. This can be proposed as one possible mechanism for the analgesic and anti-inflammatory effects induced by them.

The Role of HS-1200 Induced Autophagy in Oral Cancer Cells

Nam-Mi Jang,Sang-Hun Oh,In-Ryoung Kim,Hae-Ryoun Park,Bong-Soo Park The Korean Academy of Oral Biology 2013 International Journal of Oral Biology Vol.38 No.3

Bile acids and synthetic bile acid derivatives induce apoptosis in various kinds of cancer cells and thus have anticancer properties. Recently, it has been suggested that autophagy may play an important role in cancer therapy. However, few data are available regarding the role of autophagy in oral cancers and there have been no reports of autophagic cell death in OSCCs (oral squamous cell carcinoma cells) induced by HS-1200, a synthetic bile acid derivative. We thus examine whether HS-1200 modulates autophagy in OSCCs. Our findings indicate that HS-1200 has anticancer effects in OSCCs, and we observed in these cells that autophagic vacuoles were visible by monodansylcadaverine (MDC)and acridine orange staining. When we analyzed HS-1200-treated OSCC cells for the presence of biochemical markers, we observed that this treatment directly affects the conversion of LC-3II, degradation of p62/SQSTM1 and full-length beclin-1, cleavage of ATG5-12 and the activation of caspase. An autophagy inhibitor suppressed HS-1200-induced cell death in OSCCs, confirming that autophagy acts as a pro-death signal in these cells. Furthermore, HS-1200 shows anticancer activity against OSCCs via both autophagy and apoptosis. Our current findings suggest that HS-1200 may potentially contribute to oral cancer treatment and thus provide useful information for the future development of a new therapeutic agent.