Microfluidic room temperature ionic liquid droplet generation depending on the hydrophobicity and interfacial tension

Woo-Jin Chang,Jung Wook Hwang,Joo-Hyung Choi,최범준,이규도,이상우,구윤모 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.1

We have characterized micro-droplet generation using water immiscible hexafluorophosphate ([PF6])- and bis(trifluoromethylsulfonyl)imide ([Tf2N])-based room temperature ionic liquids (RTILs). The interfacial tension between total 7 RTILs and phosphate buffered saline (PBS) was measured using a tensiometer for the first time. PBS is one of the most commonly used buffer solutions in cell-related researches. The measured interfacial tension ranges from 8.51 to 11.62 and from 9.56 to 13.19 for [Tf2N]- and [PF6]-based RTILs, respectively. The RTILs micro-droplets were generated in a microfluidic device. The micro-droplet size and generation frequency were determined based on continuous monitoring of light transmittance at the interface in microchannel. The size of RTIL micro-droplets was inversely proportional to the increase of PBS solution flow rate and RTILs hydrophobicity, while droplet generation frequency was proportional to those changes. The measured size of RTILs droplets ranged from 0.6 to 10.5 nl, and from 1.0 to 17.1 nl for [Tf2N]- and [PF6]-based RTILs, respectively. The measured frequency of generated RTILs droplets ranged from 2.3 to 37.2 droplet/min, and from 2.7 to 17.1 droplet/min for [Tf2N]- and [PF6]-based RTILs, respectively. The capillary numbers were calculated depending on the RTILs, and ranged from 0.51×10−3 to 1.06×10−3 and from 5.00×10−3 to 8.65×10−3, for [Tf2N]- and [PF6]-based RTILs, respectively. The interfacial tension between RTILs and PBS will contribute to developing bioprocesses using immiscible RTILs. Also, the RTILs micro-droplets will enable the high-throughput monitoring of various biological and chemical reactions using RTILs as new reaction media.

Clinical Experiences and Usefulness of Cervical Posterior Stabilization with Polyaxial Screw-Rod System

Hwang, In-Chang,Kang, Dong-Ho,Han, Jong-Woo,Park, In-Sung,Lee, Chul-Hee,Park, Sun-Young The Korean Neurosurgical Society 2007 Journal of Korean neurosurgical society Vol.42 No.4

Objective : The objective of this study is to investigate the safety, surgical efficacy, and advantages of a polyaxial screw-rod system for posterior occipitocervicothoracic arthrodesis. Methods : Charts and radiographs of 32 patients who underwent posterior cervical fixation between October 2004 and February 2006 were retrospectively reviewed. Posterior cervical polyaxial screw-rod fixation was applied on the cervical spine and/or upper thoracic spine. The surgical indication was fracture or dislocation in 18, C1-2 ligamentous injury with trauma in 5, atlantoaxial instability by rheumatoid arthritis (RA) or diffuse idiopathic skeletal hyperostosis (DISH) in 4, cervical spondylosis with myelopathy in 4, and spinal metastatic tumor in 1. The patients were followed up and evaluated based on their clinical status and radiographs at 1, 3, 6 months and 1 year after surgery. Results : A total of 189 screws were implanted in 32 patients. Fixation was carried out over an average of 3.3 spinal segment (range, 2 to 7). The mean follow-up interval was 20.2 months. This system allowed for screw placement in the occiput, C1 lateral mass, C2 pars, C3-7 lateral masses, as well as the lower cervical and upper thoracic pedicles. Satisfactory bony fusion and reduction were achieved and confirmed in postoperative flexion-extension lateral radiographs and computed tomography (CT) scans in all cases. Revision surgery was required in two cases due to deep wound infection. One case needed a skin graft due to necrotic change. There was one case of kyphotic change due to adjacent segmental degeneration. There were no other complications, such as cord or vertebral artery injury, cerebrospinal fluid leak, screw malposition or back-out, or implant failure, and there were no cases of postoperative radiculopathy due to foraminal stenosis. Conclusion : Posterior cervical stabilization with a polyaxial screw-rod system is a safe and reliable technique that appears to offer several advantages over existing methods. Further biomechanical testings and clinical experiences are needed in order to determine the true benefits of this procedure.

艾灸가 家兎의 筋損傷에 미치는 影響

黃炳泰,羅昌洙,黃祐準 圓光大學校 韓醫學硏究所 1992 원광한의학 Vol.2 No.1

To know that how be effected muscle injury by moxibustion treatment, we have measured the changes in concentration of electrolytes(K^+, Na^+, Cl^-), activity of LDH and CPK from blood serum after complete compression with rubber tourniquet around the femoral area of rabbit. And we also examined effects of moxibustion applied to a meridian point Jog Sam Ri(S 36), Kan Soo(B18) on changes of concentration of electrolytes (K^+, Na^+, Cl^-), activity of LDH and CPK from blood serum at 30, 60, 90 minutes and 18 hours after release of tourniquet. The results obtained from this study were as follows; 1. Among the concentration of electrolytes, that of K^+ in B 18 group at all times for blood serum has shown a significant increase than in control group, that of Cl^- in S 36 and B 18 group at 18 hours for blood serum has shown a significant decrease than in control group. 2. The activity of LDH in B 18 group for blood serum has shown a significant decrease compared with control group, but in s 36 group has not shown a significant decrease compared with control group. 3. The activity of CPK in B 18 group for blood serum has shown a significant decrease compared with control group, but in S 36 group has shown a increase compared with control group. According to the above results, we have identified that moxibustion can recover muscle injury, and have considered that better effect upon in B18 than in S 36.

Characterization of changes in global gene expression in the brain of neuron-specific enolase/human Tau23 transgenic mice in response to overexpression of Tau protein.

Woo, Jong-Min,Park, So Jung,Kang, Ho Il,Kim, Byoung Guk,Shim, Sun Bo,Jee, Seung Wan,Lee, Su Hae,Sin, Ji Soon,Bae, Chang Joon,Jang, Mee Kyung,Cho, Chunghee,Hwang, Dae Youn,Kim, Chuel Kyu D.A. Spandidos 2010 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.25 No.5

<P>Tau is a neuronal phosphoprotein responsible for the formation of the neurofibrillary tangles in Alzheimer's disease. To characterize the changes in global gene expression in the brain of transgenic mice that overexpress human Tau23 protein in response to the increase of Tau23 phosphorylation, total RNA extracted from the hippocampus of 12-month-old transgenic and wild-type mice was converted to cDNA, labeled with biotin and hybridized to oligonucleotide microarrays. The microarray results were confirmed by real-time RT-PCR and Western blotting method. It was determined that 43 genes were up-regulated and 8 genes were down-regulated by Tau23 in transgenic mice compared to controls, based on the arbitrary difference in the 2-fold change. Among the up-regulated transcripts, those encoding for transporter and oxidoreductase were dramatically over-represented, followed by those related to regulatory molecule, cytoskeletal protein, signaling molecule, and extracellular matrix protein. Genes encoding for transcription factor, regulatory molecule, miscellaneous function, and chaperone were significantly reduced in the down-regulated group. The major genes in the up-regulated categories included Ecrg4, Folr1, Defb11, Aqp1 and Soctdc1. The major genes in the down-regulated categories were Ncor1, Gpm6a, and Hspd1. These results indicate that the microarray analysis identifies several gene functional groups and individual genes that respond to a sustained increase in Tau23 phosphorylation levels in the brain of transgenic mice. In addition, the results suggest the microarray test is a useful tool for increased understanding of the role of Tau23 protein in regulating neurodegenerative disorders.</P>

Original Article : Morphologic Characteristics of the Outer Retina in Cone Dystrophy on Spectral-domain Optical Coherence Tomography

( Soo Chang Cho ),( Se Joon Woo ),( Kyu Hyung Park ),( Jeong Min Hwang ) 대한안과학회 2013 Korean Journal of Ophthalmology Vol.27 No.1

Purpose: To investigate the morphologic changes in the outer retina of patients with cone dystrophy, using spectral-domain optical coherence tomography (SD-OCT). Methods: The medical records of 15 cone dystrophy patients examined from January 2007 to January 2012 were reviewed retrospectively. All patients underwent ophthalmic evaluation including best-corrected visual acuity (BCVA), color vision testing, fundus examination, full-field standard electroretinography (ERG), multifocal (mf) ERG, and SD-OCT. Qualitative and quantitative SD-OCT data and ERG responses were analyzed and compared among the patient categories and the normal control group. Results: There were 4 major categories of SD-OCT findings, based on the status of the ellipsoid portion of the photoreceptor inner segment (ISe), outer segment (OS) contact cylinder, and retinal pigment epithelium (RPE) layer. Category 0 showed no structural abnormalities. Category 1 showed foveal ISe loss and obscurity of the border between the ISe band and the external limiting membrane (ELM). Category 2 showed foveal thinning and focal foveal ISe disruption with an intact ELM. Category 3 showed foveal thickening and perifoveal disruption of the ISe layer. Category 1 to 3 showed OS contact cylinder layer absence and RPE thickening. The patients in category 0 tended to be younger (mean, 10.0 years) than those in categories 1 to 3 (mean, 17.6 years), although this difference was not statistically significant. Category 1 to 3 patients exhibited statistically significant thinning of the central retina and outer nuclear layer and thickening of the RPE layer relative to the category 0 and normal control group. There was a significant correlation between the central foveal thickness and BCVA in the patients with cone dystrophy. ERG and mfERG responses did not differ significantly among the different cone dystrophy categories. Conclusions: The morphologic features of cone dystrophy as revealed by SD-OCT, could be categorized as either normal or 1 of 3 different types of outer retinal changes. The presence of normal retinal structures in young cone dystrophy patients with functional impairment (category 0) indicates that electrophysiologic studies are superior to current imaging modalities for the early diagnosis of cone dystrophy. The characteristic SDOCT findings in cone dystrophy patients may aid in differential diagnosis and be useful for future research on the pathology of cone dystrophy.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

R&D 투자 영향평가 기반 구축 및 시범분석

황석원(Seog-Won, Hwang),오승환(Seung-Hwan, Oh),우청원(Ceung-Won, Woo),장필성(Pil-Seoung, Jang),홍사균(Sa-Gyun, Hong),강희종(Hee-Jong, Kang),최창택(Chang-Taek, Choi),김기환(Gi-Hwan, Kim),이재진(Jae-Jin, Lee),김지훈(Ji-Hoon, Kim) 과학기술정책연구원 2016 정책연구 Vol.- No.-

This study is a late study of “An Exploratory Study on STI policy impact assessment”. In the research of 2015, in principle, it is necessary to evaluate not only R&D investment but also general policies such as various promotion systems, standards and regulations by putting the term “policy impact assessment” in front of it We emphasized the points. However, it is practically very difficultto collect and analyze detailed data of all STI policies. In addition, it is also restricted to allow policy researchers to access data within a certain range. Therefore, this study focuses on the impact assessment of R&D investment, which accounts for the largest percentage of STI policies. In this research, the impact assessment system of R&D investment is analyzed by classifying it into evaluation of economic impact and social impact assessment. Also, the evaluation of economic impact was analyzed separating into a micro viewpoint and a macro viewpoint. First, The analysis of the economic impact assessment of the micro viewpoint relates to how the government’s R&D investment affects enterprises. Specifically, the main analysis target was the employment and investment of companies, the impact on sales and profits. Second, The Analysis for macroeconomic impact assessment on the economy is related to the influence of government’s R&D investment such as national economic growth, employment etc. We also analyzed the spillover effect by industry according to R&D investment. Third, The social impact assessment is to analyze how R&D investment has impacted technology-based social change. This study is a very difficult attempt. However, we analyzed from the point of view of the consumer considering all social change areas as much as possible. The results of the study are summarized as follows. First, the study of economic impact evaluation shows the effect of R&D investment and it can be used as a basis to improve the efficiency and goal of R&D investment in future sectors such as employment, economic growth and investment. Second, through research on social impact assessment, government R&D investment has focused on specific areas in terms of improving the quality of life and social development of people, and confirmed that most social sectors are neglected. In addition, we proposed policy priorities for specific social change indicators and social sectors and proposed long-term R&D investment strategies. Finally, this study is expected to contribute to the establishment of future strategy of private enterprise through the measurement of social change index, the social influence of private research and development, and the influence of technology shock from abroad.

Gene Expression Analysis of the Bromobenzene Treated Liver with Non-hepatotoxic Doses in Mice

Lim, Jung-Sun,Jeong, Sun-Young,Hwang, Ji-Yoon,Park, Han-Jin,Cho, Jae-Woo,Song, Chang-Woo,Kim, Yang-Seok,Lee, Wan-Seon,Moon, Jin-Hee,Han, Sang-Seop,Yoon, Seok-Joo The Korean Society of Toxicogenomics and Toxicopro 2005 Molecular & cellular toxicology Vol.1 No.4

Bromobenzene (BB) is well known hepatotoxicant. Also, BB is an industrial solvent that arouses toxicity predominantly in the liver where it causes centrilobular necrosis. BB is subjected to Cytochrome P450 mediated epoxidation followed by either conjugation with glutathione, enzymatic hydrolysis or further oxidation. In this study, we focused on BB-induced gene expression at non-hepatotoxic dose. Mice were exposed to two levels of BB, sampled at 24 h, and hepatic gene expression levels were determined to evaluate dose dependent changes. When examining the toxic dose of BB treated group in other previous studies, genes related to heat shock protein, oxidative stress, and drug metabolism are expressed. Compared to these results, our study, in which non-toxic dose of BB was administrated, showed similar patterns as the toxic conditions above. The purpose of the study was to select genes that showed changes in relation to the differing dose through confirmation of the difference within transcriptomic boundaries, but those that are not detected by the existing classic toxicology tools in non-hepatotoxic dose.

연삭가공에서 절삭유 에어로졸 측정평가에 관한 연구

황덕철,황준,우창기,정의식 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

This paper presents the experimental results to analyze the characteristics of cutting fluid aerosol generation in grinding process. Machining is a one of the broad manufacturing process to produce the parts, products and various molds and dies. The environmental impact due to aerosol generation via atomization process is a major concern associated with environmental consciousness. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near worker's breath zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This qualitative analysis can be provided the basic knowledge for further research for environmentally conscious machining technology developments.

칩브레이커 사용에 따른 밀링버의 생성특성 연구

황덕철,황준,우창기 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

This paper presents the numerical analysis and experimental verification to know the metal cutting buff formation mechanism in face milling operation. Finite element method are applied to predict the 2-D burr formation process prediction. Face milling process are adjusted to analyze the characteristics of burr shapes according to various cutting conditions. The cutting parameters were investigated with cutting speed, feed rate, depth of cut. Through a few experiments, various burr types are classified according to its shape and properties.