[연구실·기업체 탐방] 한국표준과학연구원 수소에너지소재연구팀

정낙관(Nak-Kwan Chung) 한국진공학회 2022 진공 이야기 Vol.9 No.2

Immobilizing a single DNA molecule at the apex of AFM tips through picking and ligation

Kim, Duckhoe,Chung, Nak-Kwan,Kim, Jung Sook,Park, Joon Won Royal Society of Chemistry 2010 SOFT MATTER Vol.6 No.16

<P>A proper surface treatment of the substrate and the AFM tip with a structured molecule provided a new approach to pick a single DNA molecule with reasonable success rate (75%) by AFM. Picking a single molecule by AFM tip and realizing the single interaction will likely be useful for single molecule dynamic force spectroscopy, because it avoids the formation of problematic multiple interactions. As an extension, a new single DNA was allowed to hybridize with the picked DNA, and conjugated with the picker DNA by use of a ligase. The attachment of a single DNA at the apex was confirmed by measuring the force between the new DNA and the complementary DNA on the generic surface. Various applications of the tip for manipulating single molecules and preparing new nanomaterials are envisaged.</P> <P>Graphic Abstract</P><P>Single molecule picking up was enhanced by employing AFM tips and substrates modified with dendrons. The dendron modification guaranteed the single DNA–DNA interaction and realized the attachment of a single DNA at the apex of the tip. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c001722a'> </P>

韓國結核의 疫學的硏究 (第一報)

李性寬,丁洛珍 慶北大學校 1960 論文集 Vol.4 No.-

By the epidemiological observation of wide snread tubereulosis throughout Korea(1954-1959), following results were obtained. 1)In the observation of the infection rate by age, The age group of 1-5 year olds is below 20%, but the rate shows a sharp increase at the time of entering primary school(exposure with society) and it keeps a gradual increase with age. In the age group of 18-20year olds, it is in the vicinity of 90%, in the age group of 21-25 year olds, it is approxiniately 95% which is the highest. After 25year of age, there is a slight decreasing. In Rural area the infection rate increases with age rather mildly than in urban area. 2) In the infection rate by sex, generally in urban area, the age groups of 1-6 and 13-16 year olds among female show a higher rate than among male, but in the age group of 6-12 year olds as well as 16 year olds and older age groups on male show a higher rate than in female, In Rural area, the infection rate shows quite opposite results in comparison to the Urban area. 3) In the natural infection, younger age groups of under 6 year olds show a considerably weak reaction, but over 6 year olds shows a generally strong reaction to the Tuberculin test. Among children in rural area, the reaction degree of Tuberculin is weaker than that of urban area. Tuberculin reaction degree of Japanese primary school children is weaker than that of Korean. 4) T. B. family shows a higher positive rate and stronger reaction degree to Tuberculin test compared with Non T. B. family. 5) Induration rate is very low in younger age groups and it increaseswith age. 6) In younger gae groups, the variation of tuberculin reaction is marked and only a small number shows the fixation reaction and tends to show a weak reaction, but older age groups show a generally stable reaction and no tendency of weakness with reaction degree 7) In the variation of questionable positive case, reversion is frequent in younger age group but conversion is frequent in older age group 8) Reversion of positive case is frequent in younger group especially in the group which had a weak reaction degree and no induration in tuberculin allergy. 9) In the comparison of reaction degree of various tuberculins, the most potent one is Korean O. T. and the next is American O. T. Japanese O. T. showed the lowest positive rate. 10) In the study of reaction to the different tuberculin concent-rations, younger age group shows lower infection rate with low concentration tuberculin. However the infection rate showed a marked higher rate by increase of age, which means the older age group has already contracted a slight infection with longer exposure to the external contact. 11) The rate of appearance of Necrosis and Blister in the tuberculin reaction is lower in of -der age group. 12) In tuberculin allergy after BCG vaccination, the largest reaction was obtained at 1-2month after vaccination. Reaction degree and induration rate are highest at I month after vaccination, after which they decrease gradually and reach lowest reaction at 6 months after vaccination. Increase of reaction degree from 6th month after vaccination is probably due to the reinfection. 13) In the revaccinated group, a stronger and longer signs were obtained in tuberculin reaction and induration rate comparing with the first vaccinated group. 14) The defferences in the reaction degree of various tuberculin and it's concentration are more prominent in the group of BCG vaccinated than that of natural infection. 15) In the group who became reversed after being converted with BCG vaccination, reconversion rate is very high regardless of observation period. However, after BCG vaccination, there is a slight decrease in reconversion rate in the group which elapsed long time since vaccination, but a markedly higher rate was observed than among the non vaccinated. Therefore, it is recommended to observe the T. B. infection among the groups which are in the state of readiness for the reaction like BCG vaccinators. This might be one of the reasons why the reinfection in tuberculosis is so frequent. 16) With inoculation of a small amount of living and dead BCG to the reversed group after BCG vaccination, such revaccinated group showed a markedly higher rate of tuberculin allergy which appeared very rapidly than the non vaccinated group. This is also one of the evidences to support the reinfection which mentioned above.

Ferritin-Based New Magnetic Force Microscopic Probe Detecting 10 nm Sized Magnetic Nanoparticles

Kim, Duckhoe,Chung, Nak-Kwan,Allen, Stephanie,Tendler, Saul J. B.,Park, Joon Won American Chemical Society 2012 ACS NANO Vol.6 No.1

<P>A single-molecule ferritin picking-up process was realized with the use of AFM, which was enhanced by employing controlled dendron surface chemistry. The approach enabled the placement of a single ferritin protein molecule at the very end of an AFM tip. When used for magnetic force microscopy (MFM) imaging, the tips were able to detect magnetic interactions of approximately 10 nm sized magnetic nanoparticles. The single ferritin tip also showed the characteristics of a “multifunctional” MFM probe that can sense the magnetic force from magnetic materials as well as detect the biomolecular interaction force with DNAs on the surface. The multifunctional tip enabled us not only to investigate the specific molecular interaction but also to image the magnetic interaction between the probe and the substrate, in addition to allowing the common capability of topographic imaging. Because the protein engineering of ferritin and the supporting coordination and conjugation chemistry are well-established, we envisage that it would be straightforward to extend this approach to the development of various single magnetic particle MFM probes of different compositions and sizes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-1/nn203464g/production/images/medium/nn-2011-03464g_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn203464g'>ACS Electronic Supporting Info</A></P>

The evaluation of effect of high-pressure hydrogen and RGD on NBR rubber materials

Sang Koo Jeon(전상구),Nak Kwan Chung(정낙관),Un Bong Baek(백운봉),Nae Hyung Tak(탁내형),Seung Hoon Nahm(남승훈) 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.6

골반내 동정맥 기형 환자의 무수 알코올 색전술을 위한 전신마취 -증례보고-

정진용 ( Jin Yong Chung ),이정훈 ( Jung Hun Lee ),노운석 ( Woon Seok Roh ),조성경 ( Sung Kyung Cho ),김봉일 ( Bong Il Kim ),성낙관 ( Nak Kwan Sung ) 대한마취과학회 2003 Korean Journal of Anesthesiology Vol.44 No.1

Hydrogen Permeability Measurement of EPDM Compounded with Carbon black and Silica for Hydrogen Infrastructure

Jin-Sub Jang,Chun-Joong Kim,Nak-Kwan Chung 한국진공학회 2021 한국진공학회 학술발표회초록집 Vol.2021 No.2

최근 수소전기차와 수소충전소 보급을 위해 수소 인프라에 사용되는 재료에 대한 연구개발 활발히 진행되고 있다. 수소 기체가 투과된 폴리머는 온도, 압력, 응력에 따라 다양한 파손이 발생한다. 따라서 수소기체와 폴리머 재료의 상호작용 및 투과메커니즘에 대한 연구가 필요하며, 수소의 저장 및 운송에 사용되는 재료의 높은 기밀성 유지를 위해 수소투과의 허용범주 보다 낮은 투과도소재의 개발이 필요하다. 본 연구는 EPDM에 Carbon black 또는 Silica 충진제 배합비율에 따른 수소 투과도, 확산도, 용해도를 측정하였으며, 각 충진제의 배합비율 증가에 따라 수소 투과도의 감소를 보였다.

Atomin layer Deposition of Al₂O₃ Thin Film on Anodic Aluminum Oxide for Fabrication of Standard Leak Element

Dong-Geun Lee,Chun-Joong Kim,Nak-Kwan Chung 한국진공학회 2021 한국진공학회 학술발표회초록집 Vol.2021 No.2

최근 각광을 받고 있는 수소 에너지의 안전한 사용을 위해 수소 인프라에 사용되는 비금속 소재의 수소 투과 특성 평가가 중요하다. 이에 따라 수소 대면 소재에 대한 수소 투과 특성 평가가 널리 행해지고 있으나, 아직 수소 투과도에 대한 측정표준물질이 개발되지 않아 각 소재의 신뢰성 있는 측정값을 얻는데 어려움을 겪고 있다. 따라서, 본 연구에서는 수소 투과 측정용 표준물질을 개발하기 위해 ALD를 이용하여 다공성 시편인 AAO 위에 AI<SUB>2</SUB>O<SUB>3</SUB> 박막을 증착 하여 박막 두께에 따른 Conductance의 변화를 확인하였다.

후복막에 월발성으로 생긴 편평상피세포암

유민지 ( Min Ji Ryu ),정예원 ( Ye Won Chung ),배효숙 ( Hyo Sook Bae ),이재관 ( Jae Kwan Lee ),이낙우 ( Nak Woo Lee ),송재윤 ( Jae Yun Song ) 대한산부인과학회 2012 Obstetrics & Gynecology Science Vol.55 No.10

Primary retroperitoneal squamous cell carcinoma is very rare. A 66-year-old woman presented with right leg edema and pain that had developed one month prior. Pelvis magnetic resonance imaging showed the presence of a mass around the iliac vessels invading the iliacus muscle, right femoral head and obturator muscle. The patient underwent an exploratory laparotomy but the mass was not completely removed. The patient was treated with concurrent chemoradiation therapy with paclitaxel-carboplatin and Tomotherapy three weeks after surgery. After that, she conducted a further seven cycles of different chemotherapy. A abdomen CT scan after the last seven cycles showed a reduction in the size of the primary mass from 7.2 to 6.6 cm, consistent with a partial response to treatment. As a result, the role of adjuvant chemotherapy in these tumors is controversial. And it is considered that complete resection is more important.

A correlation between pelvic node metastasis and clinical symptoms in the patient underwent staging surgery for the early-stage cervical cancer

( Ki Jin Ryu ),( Ye Won Chung ),( Hyo Sook Bae ),( Jae Kwan Lee ),( Nak Woo Lee ),( Tak Kim ),( Jae Yun Song ) 대한산부인과학회 2012 대한산부인과학회 학술대회 Vol.98 No.-

This study was conducted to evaluate the clinical factors which can expect pelvic nodal metastasis in patients with early-stage invasive cervical cancer, when nodal involvement had not been detected by pretherapeutic CT, MRI, with or without PET-CT. The medical records of 233 early-stage cervical cancer patients who had undergone staging surgery between November 1990 and February 2012 were reviewed. The incidence of histologically proved nodal metastasis was compared with the clinical factors that include age, BMI, initial symptom, clinical stage, histology, serum SCC and CEA, and postoperative complications. Statistical analysis was performed using SPSS program. Out of a total of 233 patients, nodal involvement was detected in 31(13.3%) by pathological examination. 65(28%) patients were asymptomatic, and among the 168(72%) symptomatic patients, vaginal bleeding and/or discharge was evident in 153(65%), and lower abdominal pain in 15(6%). The node-involved group showed higher rate of presenting lower abdominal pain as the initial symptom (p-value = 0.034). Clinical stage was statistically relevant to nodal involvement, but not to a type of clinical symptom. Neither the histology, age, BMI, tumor markers were, the postoperative complications (lymphedema, lymphocele) were not statistically related to pelvic nodal involvement. There was significant correlation between the histological nodal metastasis and the presentation of lower abdominal pain as initial symptom in early-stage cervical cancer patients. Although the reliability and pathophysiology of this finding are certainly need to be investigated by further studies, it might be worthwhile to consider a more active surgical lymph node dissection for management of patient with lower abdominal pain rather than vaginal bleeding or no symptom.