Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition

Han, S.H.,Cho, J.H.,Jung, H.S.,Suh, J.Y.,Kim, J.K.,Kim, Y.R.,Cho, G.,Cho, H. Elsevier 2015 NeuroImage Vol.112 No.-

<P><B>Abstract</B></P> <P>Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆<I>R<SUB>2</SUB> <SUP>⁎</SUP> </I> and ∆<I>R<SUB>2</SUB> </I>) are widely used to investigate <I>in vivo</I> vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆<I>R<SUB>2</SUB> <SUP>⁎</SUP>/∆R<SUB>2</SUB> </I>). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based <I>∆R<SUB>2</SUB> <SUP>⁎</SUP> </I> is hampered by its high sensitivity to magnetic field perturbations arising from air–tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based <I>∆R<SUB>2</SUB> <SUP>⁎</SUP> </I> measurement with ultra-short echo time (UTE)-based <I>∆R<SUB>1</SUB> </I> contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue <I>∆R<SUB>1</SUB> </I> ratio, while independent spin-echo acquisition enabled simultaneous <I>∆R<SUB>2</SUB> </I> measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>ΔR<SUB>2</SUB> <SUP>⁎</SUP> </I>-CBV is vessel orientation dependent and vulnerable to susceptibility artifacts. </LI> <LI> UTE acquisition minimizes susceptibility artifacts and enables dose-independent CBV. </LI> <LI> UTE-based CBV can theoretically and experimentally replace <I>ΔR<SUB>2</SUB> <SUP>⁎</SUP> </I> for vessel size. </LI> <LI> UTE-based <I>ΔR<SUB>1</SUB> </I> contrasts enable consistent CBV and mVSI maps in mouse brain. </LI> <LI> <I>ΔR<SUB>1</SUB> </I> and <I>ΔR<SUB>2</SUB> <SUP>⁎</SUP> </I> contrasts can be synergistically combined to enhance SPION contrast. </LI> </UL> </P>

소 모색관련 유전자 MC1R 의 RCR - RFLP Marker 를 이용한 한우육 판별

정의룡,김우태,김연수,한상기 한국동물자원과학회 2000 한국축산학회지 Vol.42 No.4

The melanocortin 1 receptor(MClR) plays a central role in regulation of eumelanin(black/brown) and phaeomelanin(red/yellow) pigment synthesis within the mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat colour variations within several species including cattle. This study was performed to develop the identification technique of Hanwoo meat using MC1R gene associated with the coat colors of cattle. Alleles of the MC1R locus were detected by PCR-RFLP analysis and genotype frequency and DNA sequences of MC1R gene were compared among cattle breeds. Genomic DNA was extracted from meat or blood samples of five breeds including Hanwoo(n=200), Holstein(n=100), Angus(n=20), Hereford(n=20) and Charolais(n=20). The MC1R gene was used to amplify 739bp and 173bp of the bovine E-locus corresponding to positions 228-966 and 318-490, respectively, using the two specific primers. The amplified products were digested with Bse118 I or Msp I and Aci I enzymes, and DNA fragments were separated by gel electrophoresis for RFLP genotype analysis. Six genotypes, E^D/E^D E^D/E^+, E^D/e, E^+/E^+,E^+/e and e/e, controlled by three alleles E^D, E^+ and e were observed in MC1 locus. When the amplified DNA product(739bp) was digested with Bse118 I enzyme, Hanwoo meat showed a single band of 739bp, whereas two fragments of 531bp and 208bp were detected in Holstein meat and Angus breed, respectively. Also, in the RFLP patterns using Msp I enzyme, Hanwoo meat produced two fragments of 535bp and 174bp, while three fragments of 328bp, 207bp and 174bp were observed in Holstein meat and Angus breeds, respectively. Therefore, breed-specific RFLP markers showing distinct differences between these breeds were found by PCR-RFLP analysis. When the amplified DNA product(173bp) was digested with Aci I enzyme to classify subtype of E allele, the E^D allele produced three fragments of 97, 68 and 8bp, while the E^+ and d alleles produced two fragments of 173 and 8bp according to the Aci I recognition sequence. Among the six genotypes, two genotypes of E^+/e and e/e were observed in Hanwoo and their frequencies were 0.07 and 0.93, respectively. However, the E^D/ED and E^D/e genotypes were present in Holstein and E^D/E^D, E^D/E^+ and E^D/e genotypes in Angus breeds. Therefore, the E^+/e and e/e genotypes observed in Hanwoo and E^D/E^D, E^D/E^+ and E^D/e genotypes detected only in Holstein and Angus breeds may be useful as breed-specific DNA markers for distinguishing between Hanwoo meat and Holstein and Angus meats. When comparing MC1R sequences among Hanwoo, Holstein and Angus, a Gly → Val amino acid change due to a single base(G) deletion at colon 104 was found in Hanwoo. Consequently, breed specific RFLP genotypes of MC1R gene related to bovine coat colors could be used as DNA markers for identification of Hanwoo meat from Holstein and Angus meats.

PCR - RFLP 기법을 이용해 젖소개량을 위한 유전적 표지로서 K- Casein 좌위의 유전자형 분석

정의룡(E . R . Chung),김우태(W . T . Kim),최석호(S . H . Choi),임태진(T . J . Rhim),한상기(S . K . Han) 한국축산학회 1995 한국축산학회지 Vol.37 No.1

Genotypes of K-casein(K-CN) locus as a genetic marker linked to quantitative trait loci affecting traits of economic importance in dairy cattle were determined by PCR-RFLP method. Genomic DNA was prepared from blood of Holstein cows. The PCR was used to amplify an 874 by region between nucleotides 10592 and 11466 from exon IV to intron IV of the bovine K-CN gene using sense primer(5`-GTGCTGAGTAGGTATCCTAG-3`) and antisense primer(5`GTAGAGTGCAACAACACTGG-3`). After amplification, PCR products were digested with four restriction enzymes, Hind III, Rsa I, Taq I, and Pst I, and the fragments were separated by agarose gel electrophoresis for RFLP analysis of K-CN locus. In addition to screening for the known Hind III and Rsa I restriction site polymorphisms of K-CN locus, we have found additional RFLPs specific for the K-CN A and B alleles in Taca I and Pst I enzymes. The amplified DNA product digested with each restriction enzyme generated specific RFLP pattern that allowed precise identification of K-CN AA, BB or AB genotypes. The K-CN genotypes determined for cows by the PCR-RFLP method agreed completely with the phenotypes obtained from milk samples of the same individuals. Thus, PCR amplification and RFLP analysis was shown to be a rapid and sensitive method for the discrimination of K-CN genotypes directly at the DNA level in dairy cattle of any age or sex. Consequently, the PCR-RFLP method presented in this study can be used as a valuable tool for early selection of AI bulls and calves with desirable K-CN B gene or K-CN BB genotype affecting superior milk production traits for genetic improvement of Holstein dairy cattle.

Phase II study and biomarker analysis of cetuximab combined with modified FOLFOX6 in advanced gastric cancer

Han, S-W,Oh, D-Y,Im, S-A,Park, S R,Lee, K-W,Song, H S,Lee, N-S,Lee, K H,Choi, I S,Lee, M H,Kim, M A,Kim, W H,Bang, Y-J,Kim, T-Y Nature Publishing Group 2009 The British journal of cancer Vol.100 No.2

<P>This prospective study was conducted with the Korean Cancer Study Group to evaluate the efficacy and safety of cetuximab combined with modified FOLFOX6 (mFOLFOX6) as first-line treatment in recurrent or metastatic gastric cancer and to identify potential predictive biomarkers. Patients received cetuximab 400 mg m<SUP>−2</SUP> at week 1 and 250 mg m<SUP>−2</SUP> weekly thereafter until disease progression. Oxaliplatin (100 mg m<SUP>−2</SUP>) and leucovorin (100 mg m<SUP>−2</SUP>) were administered as a 2-h infusion followed by a 46-h continuous infusion of 5-fluorouracil (2400 mg m<SUP>−2</SUP>) every 2 weeks for a maximum of 12 cycles. Biomarkers potentially associated with efficacy were analysed. Among 38 evaluable patients, confirmed response rate (RR) was 50.0% (95% CI 34.1–65.9). Median time-to-progression (TTP) was 5.5 months (95% CI 4.5–6.5) and overall survival (OS) 9.9 months. Eleven patients having tumour EGFR expression by immunohistochemistry with low serum EGF and TGF-<I>α</I> levels showed a 100% RR compared to 37.0% in the remaining 27 patients (<I>P</I><0.001). Moreover, ligand level increased when disease progressed in seven out of eight patients with EGFR expression and low baseline ligand level. No patient exhibited EGFR amplification or K-ras mutations. Gastric cancer patients with EGFR expression and low ligand levels had better outcomes with cetuximab/mFOLFOX6 treatment.</P>

Results and Analysis of an Accident in 35-kWh SFES

Han, Y. H.,Park, K. J.,Park, B. J.,Jung, S. Y.,Han, S. C.,Lee, W. R.,Bae, Y. C. IEEE 2013 IEEE transactions on applied superconductivity Vol.23 No.6

<P>A 35-kWh superconductor flywheel energy storage (SFES) system using hybrid bearing sets, which is composed of a high-temperature superconductor bearing and an active magnet damper, has been developed in the Korea Electric Power Corporation Research Institute (KEPRI). To keep the flywheel system safe, backup bearings were adapted, and a ball bearing was selected through simulations. The 35-kWh SFES was tested up to 6500 r/min successfully. During rotation tests, there were few accidents. An accident occurred while decreasing speed, at around 4000 r/min. Although the backup bearing was damaged to keep the flywheel system safe, the shaft was also damaged. Contact due to the elongation of the flywheel shaft was considered as the reason for the accident. Some results of the accident are described and analyzed.</P>

MOA-2010-BLG-073L: AN M-DWARF WITH A SUBSTELLAR COMPANION AT THE PLANET/BROWN DWARF BOUNDARY

Street, R. A.,Choi, J.-Y.,Tsapras, Y.,Han, C.,Furusawa, K.,Hundertmark, M.,Gould, A.,Sumi, T.,Bond, I. A.,Wouters, D.,Zellem, R.,Udalski, A.,Snodgrass, C.,Horne, K.,Dominik, M.,Browne, P.,Kains, N.,Br IOP Publishing 2013 The Astrophysical journal Vol.763 No.1

<P>We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because the source was previously known to be photometrically variable. Analyzing the pre-event source light curve, we demonstrate that it is an irregular variable over timescales >200 days. Its dereddened color, (V - I)(S),(0), is 1.221 +/- 0.051 mag, and from our lens model we derive a source radius of 14.7 +/- 1.3 R-circle dot, suggesting that it is a red giant star. We initially explored a number of purely microlensing models for the event but found a residual gradient in the data taken prior to and after the event. This is likely to be due to the variability of the source rather than part of the lensing event, so we incorporated a slope parameter in our model in order to derive the true parameters of the lensing system. We find that the lensing system has a mass ratio of q = 0.0654 +/- 0.0006. The Einstein crossing time of the event, t(E) = 44.3 +/- 0.1 days, was sufficiently long that the light curve exhibited parallax effects. In addition, the source trajectory relative to the large caustic structure allowed the orbital motion of the lens system to be detected. Combining the parallax with the Einstein radius, we were able to derive the distance to the lens, D-L = 2.8 +/- 0.4 kpc, and the masses of the lensing objects. The primary of the lens is an M-dwarf with M-L,M-1 = 0.16 +/- 0.03 M-circle dot, while the companion has M-L,M-2 = 11.0 +/- 2.0 M-J, putting it in the boundary zone between planets and brown dwarfs.</P>

PCR - SSCP 기법을 이용한 소 MC1R 유전자의 다형성 분석 및 한우육 감별

정의룡,김우태,김연수,한상기 한국동물자원과학회 2001 한국축산학회지 Vol.43 No.1

The single-strand conformation polymorphism(SSCP) is a point mutation screening method based on changes in the secondary structure in a defined single-stranded DNA fragment caused by a change in sequence. This study was performed to develop the identification technique of Hanwoo meat using PCR-SSCP marker of MC1R gene associated with the coat colors of cattle. Hanwoo, Holstein and imported cattle breeds(Angus, Hereford and Charolais) were used for the detection of PCR-SSCP genotypes of MC1R gene. The specific primers were used to amplify a 138bp and a 390bp of the bovine E-locus(including point mutation) corresponding to positions 318-455 and 318-707, respectively, in the MC1R gene. For SSCP genotype analysis, the PCR products were denatured at 95℃ for 5min, loaded on a 12-15% nondenaturing polyacrylamide gel and detected by silver staining. When the PCR product of 138bp was separated by gel electrophoresis, two genotypes of E^+/e and e/e were detected only in Hanwoo meat, but E^D/E^D and E^D/e and E^D/E^D genotypes were observed in Holstein meat and Angus breed, respectively. Also, in the SSCP analysis using PCR product of 390bp, Hanwoo meat produced banding pattern of two fragments, while single fragment was observed in Holstein meat and Angus breed. Therefore, breed-specific SSCP markers showing distinct differences between Hanwoo and Holstein and Angus were found by PCR-SSCP analysis. This study shows that the PCR-SSCP technique is relatively simple, fast and a practical tool for determination of MC1R genotypes of cattle breeds when compared with PCR-RFLP method. Therefore, the PCR-SSCP markers of MC1R gene could be used as DNA markers for identification of Hanwoo meat from Holstein and Angus meats.

Design of the Cryogenic System for 100 MVA HTS Transformer

Kim, S.R.,Han, J.,Kim, W.S.,Park, M.J.,Lee, S.W.,Choi, K.D. Institute of Electrical and Electronics Engineers 2007 IEEE transactions on applied superconductivity Vol.17 No.2

<P>A 100 MVA, commercial class high temperature superconducting (HTS) transformer was designed. In this paper the cryogenic system to extract the heat generated at the winding due to the AC loss and the heat penetration through the wall and the current lead and keep the winding temperature under design temperature is presented. The operation temperature is set at 67 K to increase the critical current and reduce the amount of HTS tape usage and the volume. The HTS winding was concentrically arranged to reduce the AC loss. The system consists of main cryostat with the windings and secondary cryostat with cooler, cryopump and the heat exchanger inside. The liquid nitrogen is entering the main cryostat at 65 K and assumed to be leaving at 67 K. The winding temperature distribution is simulated with the anticipated heat load using Fluent. The effect of the liquid nitrogen flow rate, inlet location is investigated and discussed.</P>

이탈리안라이그라스의 방습평형함수율 모델

한재웅 ( J. W. Han ),김훈 ( H. Kim ),배희수 ( H. S. Bae ),김락우 ( R. W. Kim ),이승기 ( S. K. Lee ),김성록 ( S. R. Kim ),김웅 ( W. Kim ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.1

이탈리안라이그라스(Itallian Ryegrass, IRG)는 사료작물로 동계사료 작물 중 70%이상의 비율을 차지하고 있으며, 재배면적이 지속적인 증가 추세에 있다. 그러나 IRG종자 채종의 경우 수확시기가 벼의 이앙시기와 겹쳐 조기 종자 수확으로 인하여 건조에 불리한 조건을 가지고 있다. 따라서 본 연구는 고수분의 IRG 종자의 건조에 필요한 방습평형함수율 모델의 개발을 위해 수행되었다. 평형함수율은 주위 공기의 온도와 상대습도의 함수로 표시되며, 이를 평형함수율 모델이라 하며, 일반적으로 4개의 모델(Modified Henderson, Chung-Pfost, Modified Halsey, Modified Oswin)이 이용되고 있다. IRG종자의 평형함수율 모델 개발을 위한 측정은 동적측정방법을 이용하였고 건조온도 20, 30 및 40℃ 3수준, 상대습도는 30, 40, 50 및 60%의 4수준으로 총 12수준에 대하여 3회 반복 실험 후 평균값을 사용하였다. 분석방법은 SAS 9.4(SAS Institure Inc., USA)의 비선형회귀분석 프로그램을 이용하여 실험상수를 결정하였으며, R² 및 RMSE를 모델의 비교 검정에 이용하였다. 4개의 모델 중 평형함수율의 실험값과 모델에 의한 예측값 사이의 RMSE는 Modified Oswin모델의 경우 0.480%,d.b.가 가장 낮게 나타났으며, Chung-Pfost모델이 0.692%,d.b.로 높게 나타났으나 그 외 모델 모두 비슷한 값을 나타내었다. 평형함수율모델의 결정계수(R² )는 Chung-Pfost모델의 경우 0.97이상의 높게 나타났으며, 다른 모델도 0.95%이상으로 잘 일치하였다. Chung-Pfost모델을 제외한 모델의 경우 상대습도 50% 이상 건조온도가 고온일수록 예측값과의 차이가 크게 나타났으나 Chung-Pfost모델의 경우 건조온도 및 상대습도 변화에 따라 예측값과 잘 일치하였다. 따라서 습도가 50%이하의 건조시에는 모든 모델의 사용이 모두 가능하나 상대습도 50%이상의 건조시에는 적용 모델은 Chung-Pfost모델이 모든 건조 영역에서 가장 적합한 것으로 나타났다.

유지혈액투석 환자에 있어 영양상태와 염증지표의 관계에 대한 연구

한상엽(S. Y. Han),조상경(S. K. Jo),윤종우(J. W. Yoon),신진호(J. H. Shin),이소영(S. Y. Lee),차대룡(D. R. Cha),권영주(Y. J. Kwon),조원용(W. Y. Cho),표희정(H. J. Pyo),정태시(T. S. Jung) 대한신장학회 2000 Kidney Research and Clinical Practice Vol.19 No.2

N/A Malnutrition is known to be an independent risk factor of morbidity and mortality in hemodialysis patients. The causes of malnutrition were obsucure. Several catabolic cytokines such as interleukin-1β(IL-1β), interleukin-6(IL-6), and tumar necrosis fac-tor-α(TNF-α) were reported to be elevated in hemo-dialysis patients with malnutrition, To evaluate the nutritrional status and relationship among cytokines IL-1β, TNF-α, and various parameters, we performed a cross-sectional study in maintenance hemodialysis patients who have undergone for six months at least. Patients who were taking steroid. showed any sign of infection, or had residual renal function were excluded from the study. Nutritional status was classified into well nourished(A), mild to moderate malnutrition(B), and severe malnutrition(C) by using subjective global assessment(SGA). Patients were divided into two groups (I: A, II: B and C) based on SGA. The level of IL-10, TNF-a were estimated by ELISA. Total patients were 23(M/F:15/8 mean age 52.0±1.56yrs). There were significant differences in weight changes for 6 months, CRP, and SGA between two groups based on the level of serum albumin(using 4.0g/dL as a cutoff value). Moreover, based on SGA, there were significant differences in age, BMI, CRP, and albumin between the group I and IL Serum albumin levels was directly correlated with transferrin(r=0.302, p=0.04), and was inversly correlated with age(r=-0.329, p=0.007). TNF- u was inversly correlated with Kt/Vueea(r=-0.291, p= 0.047), and directly correlated with the duration of maintenance hemodialysis(r=0,346, p=0.036), BMI(r-0.453, p<0.05). These data support the fact that albumin and CRP can be a good marker of nutritional status in maintenance hemodialysis patient. However cytokines and transferrin might not be related to nutritional status.