Precise determination of the lithium isotope ratio in geological samples using MC-ICP-MS with cool plasma

Choi, Min Seok,Ryu, Jong-Sik,Park, Ha Yan,Lee, Kwang-Sik,Kil, Youngwoo,Shin, Hyung Seon The Royal Society of Chemistry 2013 Journal of analytical atomic spectrometry Vol.28 No.4

<P>Lithium has two naturally occurring isotopes, <SUP>6</SUP>Li and <SUP>7</SUP>Li, with approximate relative abundances of 7.5% and 92.5%, respectively. Due to large Li isotope variations in nature, lithium isotopes have the potential to reveal important information relevant to nuclear technology, biomedicine, astrophysics, and geochemistry. With the advent of multi-collector inductively coupled mass spectrometry (MC-ICP-MS), studies of Li isotopes have largely focused on the analysis of geological materials, with varying degrees of accuracy. However, this technique has often been affected by either baseline interferences or isobaric interferences on mass 6 and 7 during ionization in Ar plasma, which is mainly due to the Li compound with hydrogen gas, and double-charged nitrogen and carbon ions at higher levels of RF power. In this study, we reduced baseline interferences in Ar plasma using a cool plasma (∼800 W) technique with a X-type cone. Lithium was separated using a cation exchange column (BioRad AG50W-X8, 200–400 mesh) with a mixture of 6 N HNO<SUB>3</SUB> and 80% methanol at <0.2 mL min<SUP>−1</SUP> elution speed. The short-term reproducibility of <I>δ</I><SUP>7</SUP>Li values of the NASS-5 seawater standard was 30.55 ± 0.45‰ (2<I>σ</I>, <I>n</I> = 15). Measured <I>δ</I><SUP>7</SUP>Li values of rock and seawater standards ranged from 2.48 to 30.55‰, in good agreements with reported values.</P> <P>Graphic Abstract</P><P>Average <I>δ</I><SUP>7</SUP>Li values of a pure L-SVEC Li solution and one passed through the column were 0.00 ± 0.23‰ (2<I>σ</I>, <I>n</I> = 26) and ¬0.01 ± 0.20 ‰ (2<I>σ</I> , <I>n</I> = 9), respectively, indicating that our chemical separation procedure for Li induces no mass fractionation. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2ja30293d'> </P>

연구보문 : 자연과학 ; 황산처리에 의한 불투수성 황근 종자의 발아촉진에 관한 연구

서상흠 ( Sang Heum Seo ),박민우 ( Min Woo Park ),장미하 ( Mi Ha Chang ),장일웅 ( Il Ung Jang ),심상인 ( Sang In Shim ),나영왕 ( Young Wang Na ),김수영 ( Soo Young Kim ),김석현 ( Seok Hyeon Kim ) 한국국제농업개발학회 2012 韓國國際農業開發學會誌 Vol.24 No.3

The reason of poor germination rate of hamabo mallow seed was speculated using TZ test to determine the viability of seed. Seeds showed high viability via TZ test were not germinated well. The quiescent seeds did not imbibed properly due to the hard seed coat and did not show further processes required for germination. Several well-known treatments for seed coat loosening and water uptake into seed were applied and compared for their efficiency. Stratification, hot water treatment, seed coat scarification, wet-cold treatment were revealed as less effective for improving germination although those treatments were common method for breaking dormant seed. Chemical scarification with sulfuric acid, however, effectively increased germinability and promptness index of hamabo mallow seeds. Optimal time for sulfuric acid treatment was 20 min. Seeds treated for 20 min showed improved germination percentage, germination speed, and promptness index of 80%, 13, and 1969 at 30 days after imbibition, respectively, in petri dish experiment. The values were greater than control seeds showed low values (12%, 1, and 183, respectively). The similar tendency was observed in the pot experiment that sulfuric acid treated seed were sown in artificially mixed soil (loamy soil:peatmoss:sand:compost = 5:2:2:1) and placed in greenhouse. Ultrastructure analysis of chemically scarified seed with sulfuric acid for 20 min by scanning electron microscopy did not show any noticeable changes in seed coat hardness and water uptake via hilum. But the only change after sulfuric acid treatment was removal of hilum cap that close the hilum and hider imbibition. Therefore, subsequent experiment was conducted to know the relationship between removal of hilum cap and facilitated imbibition by sulfuric acid treatment and whether the hilum cap removal directly influenced to the opening of micropyle. Water uptake velocity of seed treated for 20 min in concentrated sulfuric acid for was greater than control seed. This result implies that the crucial effect of sulfuric acid treatment is the removal of hilum cap that increase water uptake via micropyle in hamabo mallow.

도파민 치료와 연관된 딸꾹질 1예

하윤석,김민정 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.2

Drug induced hiccups may be associated with a various agents, including corticoste-roid, antibiotics, and benzodiazepines. Rarely, levodopa or dopamine agonist therapy in Parkinson’s disease patient, can trigger hiccups. We report a case of persistent hiccup, occurring with dopaminergic medication in a patient with Parkinson’s disease 약물 유발성 딸꾹질은 코르티코스테로이드, 항생제 그리고 벤조디아제핀 등의 약물에 의하여 발생할 수 있다. 드물게 파킨슨병의 치료 목적으로 사용하는 레보도파나 도파민 효현제가 딸꾹질을 유발시킬 수 있다. 저자들은 파킨슨병의 치료 목적으로 레보도파와 도파민 효현제를 사용한 환자에서 조절되지 않는 딸꾹질을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

국내 주요 상수원수와 처리수에서 HAAs 생성 특성

염철민,최유식,변석종,조순행,윤제용 대한상하수도학회 2002 상하수도학회지 Vol.16 No.2

This study was conducted to investigate the haloacetic acid (HAAs) formation characteristics in raw and treated water in Korea. The raw and treated water from the five major rivers were examined to measure the HAAs concentrations and compared those with literature values. Major findings are as follows. First, average HAAs concentration of treated water (collected from three water treatment plants) in Korea appeared to be 62.5±66.7㎍/L (n=7) and this level is higher than the average trihalomethanes (THMs) concentration (13.2±12.9㎍/L, n=6933) reported recently. Second, the average formation potential of TCAA and DCAA after three days was found as 103±74㎍/L (n=14) and 76±36㎍/L (n=14), respectively. As this result was applied to US-EPA developed model equation for TCAA and DCAA formation, dissolved organic matter (DOM) in Korea has a tendency to produce more TCAA and DCAA as compared to US. This phenomenon was especially notable in DCAA. The sum of weight percentage of TCAA and DCAA which are individual component of HAAS was composed of 80% of HAAs.

국내 상수원수의 유기물 특성에 따른 소독부산물 생성능

염철민,변석종,조순행,윤제용 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

This study was conducted to investigate the characteristics of disinfection by-products formation potential (DBPFPs) of dissolved organics. Dissolved organics in raw water were separated into two fractions ((1) hydrophilic and (2) hydrophobic) for the measurement of DBPs. Three types of DBPs (trihalomethanes (THMs), haloacetic acids (HAAs), and total organic halides (TOX)) were measured at 3days and 7days incubation time. Sample waters were collected from the Han River and the Wonchun Reservoir. Two major findings are as follows. First, THMFPs/DOC, HAAFPs/DOC and TOXFPs/DOC in the hydrophilic organic component had a level of lower value than those of the hydrophobic organic component. Brominated THMs and bominated HAAs were not found in the chlorinated hydrophobic organic component. Second, the magnitude of HAAFPs/DOC were higher than that of THMFPs/DOC in both hydrophilic and hydrophobic organic components. This results support the reported observation that HAAs formations were higher than that of THMs in chlorinated drinking water. THMFPs and HAAFPs comprised 53-91% of TOXFP.

Totally Laparoscopic Pancreaticoduodenectomy Using 3D Flexible Laparoscopic System

( Heon Tak Ha ),( Ja Ryung Han ),( Hyung Jun Kwon ),( Jae Min Chun ),( Sang-geol Kim ),( Yoon Jin Hwang ),( Young Seok Han ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Robotic PD has not yet been expanded due to the needs of the dedicated teams and the excessive costs. 3D flexible laparoscopic system (3D) with depth perception and spatial orientation allows the precise dissection of the dangerous site and facilitate the comfortable reconstruction. We present experiences regarding the efficacy of L-PD using 3D. Methods: Totally L-PD was attempted in 15 patients from June 2016 to June 2017. However, conversion to open PD was required in one patient with tumor invasion to the superior mesenteric vein. Pancreaticojejunostomy was completed with the dunking procedure in 1 patient and with duct-to-mucosa technique in 13 patients. Results: Mean operation time was 500 min. The replaced right hepatic artery originated from superior mesenteric artery of hepatic artery was identified in one patient and preserved well because of the precise dissection under the excellent visual field. The mean size of pancreatic duct and hepatic duct were 3 mm and 10 mm. There was no major intra-operative complications and post-operative mortality. Postoperative complications were detected in 7 patients, including pancreatic fistula (n=5), and delayed gastric emptying (n=2). All pancreatic fistula was grade A and were recovered with conservative treatment. Conclusions: In selected patients, L-PD is a safe and effective procedure with comparable surgical outcomes to open surgery. Especially, we believe that 3D will play an important role in the expansion of complicated PD surgery and will provide a bridge role for future robot systems.

CFRP 판재의 섬유방향에 따른 절삭성 평가

신봉철,하석재,강민형,권오양,조명우 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

In recent, the CFRP(Carbon Fiber Reinforced Plastics) composite has been widely used because it has light-weight and high mechanical strength. Therefore, CFRP composite is applied to variable industrial areas such as aerospace, automobiles, sporting goods, ships and so on. Generally, CFRP composite has been used in the industrial field by mechanical cutting processes. In this research, the CFRP composite specimen are laminated by 64plies with orientation angles such as 0°, 45°, 90° and [0°/±45°/90°]4S. The results are analyzed with cutting force and cutting surface.

지지막을 이용하는 액막 추출기 내에서 아연 이온의 이동

주창식,이석희,이민규,홍성수,하홍두,정석기 한국환경과학회 2000 한국환경과학회지 Vol.9 No.2

For the purpose of development of a liquid membrane permeator which separates metal ions from aqueous solutions continuously and effectively, a continuous membrane permeator with the membrane solution trapped between extraction and stripping phases by two micro-porous hydrophilic films was manufactured. Experimental researches on the separation of zinc ion from aqueous solutions were performed in the liquid membrane permeator with 30 vol % D_2EHPA solution in kerosine as liquid membrane. As results, the liquid membrane permeator separates zinc ion from aqueous solutions continuously and effectively in the wide range of operating conditions. A simple mass transfer rate model using equilibrium constant of the extraction reaction for the system used were proposed, and the model was compared with experimental results of separation of zinc ion in the permeator. And the effects of operating factors, such as space time, pH of extraction solution, extraction temperature, on the separation rate of zinc ion in the permeator were experimentally examined.

구미지역 직업성질환 감시체계

김성아,김진석,전혜리,정상재,김상우,이채용,함정오,유재영,최태성,하봉구,조민환,우극현 大韓産業醫學會 2003 대한직업환경의학회지 Vol.15 No.1

목적: 구미지역 내 대학병원이자 특수건강진단·보건관리대행기관의 산업의학전문의, 보건관리대행 간호사, 사업장 간호사를 중심으로 직업성질환감시체계를 구축하여 주요 직업성질환들의 발생현황과 규모를 파악하고자 하였다. 또한 연차적으로 산업, 직업, 업무내용 등에 따른 분포나 원인을 기존 자료원(특수건강진단의 직업병 유소견자와 산재요양승인 되는 직업병자)과 비교하여 분석·기술하고 예방 및 관리를 포함한 보건의료기술개발까지을 포함하는 종합적인 감시체계를 구축하고 운용하고자 하였다. 방법: 구미지역의 산업적 특성에 맞는 직업성질환감시체계를 구축하고 지역 감시체계의 모델을 제시하였다. 6대 감시대상 직업성질환(독성 간염, 직업성천식, 직업성 근골격계질환, 직업성 피부질환, 직업성 암, 수지진동증후군)의 실행적 환례정의, 보고양식 및 보고체계 개발, 분석양식 및 결과 배포 형식을 개발하였으며, 그 유병규모를 파악하고, 감시질환의 분포 및 특성, 관련인자 등을 분석·기술하고자 하였다. 이때, 1년간의 환례분석시 직업병 유소견자 및 직업병 요양자에 대한 자료와 함께 비교 분석하였으며, 노동통계자료를 이용하여 년간 발생률을 추정하였다. 결과: 2001. 1. 1일부터 2002.4.30일까지 총 287건이 보고되었으며, 직업성 근골격계질환 132건(46.0%), 직업성 피부질환 100건(34.8%), 독성간염 34건 (11.8%), 직업성천식 16건 (5.6%), 수지진동증후군 5건 (1.7%) 이었으며 직업성 암은 한건도 보고되지 않았다. 보고경로별로는 보건관리대행에서 33건 (11.5%), 해당 유해인자별로 실시되는 특수검진 외의 각종 건강진단업무 수행 중 발견된 환례에 대한 보고가 206건(71.7%)이었다. 직종별 분류의 결과는 섬유업종사자, 단순노무종사자, 음식업종사자 등이 다수를 차지하였다. 근골격계질환의 경우, 수근관증후군이 42건(33%), 외상과염/내상과염이 39건(30%)로 가장 많았다. 직업성 피부질환은 97건이 접촉성 피부염으로 유기용제류가 59건(59%)으로 가장 많고, 니켈 및 에폭시수지에 의한 알레르기성 접촉성 피부염이 각각 6건과 5건이었다. 독성 간염은 모두 DMF 나 DMAc에 의한 것으로, 근무시작 후부터 간기능이상이 발견되기까지의 근무기간은 대부분이 3개월 이하이며, 1개월 이하인 경우도 10건이나 되었다. 동 기간 중 감시환례에 대해 산재요양 자료와 중복여부를 확인한 결과, 중복되는 것은 하나도 없었다. 특수건강진단에서 직업병유소견자로 판정된 경우는 독성간염에서 3건이 있었으며, 나머지 질환은 중복되는 것은 없었다. 2001도 구미지역의 근로자수와 보고환례건수를 이용하여 연간 발생률을 추정하였다. 근로자 10만 명당 연간 발생률은 상지 근골격계질환은 63.6명, 피부질환 48.2명, 독성 간염 17.9명, 천식 7.7명, 수진진동증후군 2.4명이었다. 참여예상인원은 총 46명이었으며, 실제 참여자수는 21명, 평균참여율은 46%, 실제 참여 1이당 평균 보고건수는 산업의학전문의가 28건으로 가장 많았고, 대행간호사는 45,건, 사업장 간호사는 3.3건이었다. 결론: 지역 감시체계는 기존 통계자료들에서 발견되지 않았던 직업성질환의 발견에 유용한 통계원이며, 특히 지역의 특성과 여건을 고려하여 체계화된 시스템을 구축하여 운용한다면 더 성과가 클 것이다. Objectives: Area-based occupational disease surveillance in Kumi (KODS) was used to collect data on occupational diseases. The data was used to estimate the magnitude of the diseases, to analyze for their characteristics and to find links for their intervention and prevention. Methods: Since January 2001, occupational physicians and nurses in Occupational Health Service (OHS) have reported six major occupational diseases; occuaptional musculoskeletal disorders of the upper extremities (MSDUE), occupational dermatoses, toxic hepatitis, occupational asthma (OA), hand-arm vibration syndrome (HAVS), and occupational cancer. For the respective diseases, a reporting sheet and operational diagnostic criteria were developed by the KODS. An analysis of the KODS data, collected over a certain period, was compared with data from the Korea Labor Workers Corporation (KLWC) and the Specific Health Examination (SHE), and the incidence rates of the diseases estimated. Results: Between Jan 2001 and Apr 2002, 287 cases of the six major occupational disease were reported. Of these, there were 132 (46.0%), 100 (34.8%), 34 (11.8%), 16 (5.6%), and 5 (1.7%), cases of MSDUE, occupational dermatoses, toxic hepatitis, OA, and HAVS, repectively. But, there were no cases of occupational cancer. 33 (11.5%) of the incidence were reported via the OHS, 206 (71.7%) from health checkups, and the other 48(16.8%) from other routes. The synthetic fibers and electronic components manufacturing industries accounted for the greatest number of reported cases. With resport to occupation, the greatest numbers of incidence were reported from the elementary occupations, textile workers, assemblers, and cooks and food services worker, in that order. Of the MSDUE cases, carpal tunnel syndrome and epicondylitis were the two most common diseases. Most of the occupational dermatoses were due to contact dermatitis, with organic solvents (59%), nickel (6%), and epoxy resin (5%) accounting for the majority of these cases. All cases of toxic hepatitis were induced by dimethylformamide or dimethylacetamide, which were reported by a unique monitoring system. During same period, there were no cases claimed by workers to the KLWC, and only three cases from SHE, were identified. Using data from workers' number and surveillance, the annual incidence of MSDUE, dermatoses, hepatitis, OA, and HAVS, per 100,000 workers were 63.6, 48.2, 17.9, 7.7, and 2.4, respectively. Conclusions: These results show that an area-based surveillance system can be very effective for the collection of data on work-related diseases, at least in Kumi.

목질바이오매스의 초임계수 처리에 의한 리그닌의 화학적 변환

이수민(Lee, Soo-Min),이오규(Lee, Oh-Kyu),최석환(Choi, Seok-Hwan),최준원(Choi, Joon-Weon),최돈하(Choi, Don-Ha) 한국신재생에너지학회 2008 한국신재생에너지학회 학술대회논문집 Vol.2008 No.05

The modified supercritical water treatment method is adopted for hydrolysis of wood powder, Populus albatimesglandulosa. This modified method is containing 0.05% HCl or HNO₃ as acid catalyst. The supercritical water treatment(SCW) was performed for 1 min. with 350?C, 380?C, 400?C and 425?C, respectively, under 230 pm 10 atm using continuous flow system. When acid was added to powder prepared for SCW treatment, the yields of monomeric sugars were significantly increased. The lignin remained after supercritical treatment was applied to gel permeation chromatography(GPC) for molecular weight distribution analysis. Compared to the lignin produced from SCW treatment without acid catalyst, the average molecular weight of lignin compounds treated with acid was clearly decreased. Particularly, Mn/Mw ratio is decreased. This result shows supercritical water treatment of wood powder can change the molecular weight of lignin to small size. However, it is necessary to be further studied for exactly characterizing the lignin produced from supercritical water treatment.