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>

Liver-directed gene therapy of diabetic rats using an HVJ-E vector containing EBV plasmids expressing insulin and GLUT 2 transporter

Kim, Y D,Park, K-G,Morishita, R,Kaneda, Y,Kim, S-Y,Song, D-K,Kim, H-S,Nam, C-W,Lee, H C,Lee, K-U,Park, J-Y,Kim, B-W,Kim, J-G,Lee, I-K Nature Publishing Group 2006 Gene Therapy Vol.13 No.3

Insulin gene therapy in clinical medicine is currently hampered by the inability to regulate insulin secretion in a physiological manner, the inefficiency with which the gene is delivered, and the short duration of gene expression. To address these issues, we injected the liver of streptozotocin-induced diabetic rats with hemagglutinating virus of Japan-envelope (HVJ-E) vectors containing Epstein–Barr virus (EBV) plasmids encoding the genes for insulin and the GLUT 2 transporter. Efficient delivery of the genes was achieved with the HVJ-E vector, and the use of the EBV replicon vector led to prolonged hepatic gene expression. Blood glucose levels were normalized for at least 3 weeks as a result of the gene therapy. Cotransfection of GLUT 2 with insulin permitted the diabetic rats to regulate their blood glucose levels upon exogenous glucose loading in a physiologically appropriate manner and improved postprandial glucose levels. Moreover, cotransfection with insulin and GLUT 2 genes led to in vitro glucose-stimulated insulin secretion that involved the closure of K<SUB>ATP</SUB> channels. The present study represents a new way to efficiently deliver insulin gene in vivo that is regulated by ambient glucose level with prolonged gene expression. This may provide a basis to overcome limitations of insulin gene therapy in humans.Gene Therapy (2006) 13, 216–224. doi:10.1038/sj.gt.3302644; published online 22 September 2005

체외배양한 인제대정맥혈관내피세포에서 R. tsutsugamushi 감염이 Tissue Factor와 Type 1 Plasminogen Activator Inhibitor의 발현에 미치는 영향에 관한 연구

김미란,기선호,배현주,장우현,박선양,최강원 대한감염학회 1995 감염 Vol.27 No.4

목적:쯔쯔가무시질환시 생기는 전신혈액응고장애의 병인 기전이 rickettsia의 침투에 의한 혈관내피세포의 손상, 그에 따른 tissue factor의 발현, 뒤이은 tissue type plasminogen activator(tPA)의 분비와 보상기전으로 type 1 plasminogen activator inhibitor(PAI-1)이 분비되는 과정으로 생각하고 이를 보고자 연구를 시행하였다. 방법:체외배양한 혈관내피세포에 순수분리한 Rickettsia tsutsugamushi를 감염시킨후 상층액에서 ELISA법으로 tPA와 PAI-1을 측정하였고 혈관내피세포 단층배양에서 면역형광법으로 tissue factor를 측정하였으며 PAI-1 유전자의 발현을 확인하고자 Northern blot analysis로 PAI-1 mRNA를 확인하였다. 결과: 1) PAI-1 R. tsutsugamushi를 감염시킨후 24시간에 가장 높은 농도를 보이며 그 증가량은 정상대조군에 비해 2.5배에서 4.7배까지 증가 하였다. 2) R. tsutsugamushi를 감염시킨후 혈관내피세포에서 분비되는 tPA의 분비는 정상대조군에 비해 유의한 차이를 보이지 않았다. 3) Northern blot analysis에 의한 PAI-1 mRNA의 발현 검색 결과 정상대조군에 비해 R. tsutsugamush가 감염된 혈관내피세포에서는 PAI-1의 발현이 2.5배 정도 증가하였다. 4) 혈관내피세포 단층배양에 R. tsutsugamushi를 감염시킨후 24시간에 tissue factor단일클론 항체와 FITC-conjugated anti mouse IgG를 이용한 간접 면역형광항체법으로 tissue factor를 측정한 결과 혈관내피세포 표면에서 tissue factor의 존재를 확인할 수 있었다. 결론:단층배양한 혈관내피세포에 R. tsutsugamushi를 감염시켰을 때 tissue factor가 발현되었고 PAI-1의 분비가 증가하여 24시간에 가장 많이 분비되었다. 그러나 tPA의 분비는 정상대조군에 비해 유의한 차이를 보이지 않았다. Nothern blot analysis를 통한 PAI-1 mRNA의 발현 검색 결과 PAI-1이 새로이 생성되어 분비됨을 확인하였다. Background:Tissue type plasminogen activator(tPA), type 1 plasminogen activator inhibitor (PAI-1), and von Willebrand factor are known to be released into the sera of patients in disseminated intravascular coagulation(DIC). The main pathologic mechanism of tsutsugamushi disease is the vasculitis by direct endothelial cell invasion by R. tsutsugamushi which dosen't have endotoxin. It is suspected that the mechanisms of DIC and activation of plasminogen activation system are different from those of sepsis by other organisms. which is caused by endotoxin. We suspect that direct rickettsial invasion of endothelial cells causes endothelial cell damage, tissue factor release, which is followed by DIC, and tPA and PAI-1 are released as compensatory mechanism. Methods:We cultured endothelial cells from human umbilical cord vein, infected them with purified R. tsutsugamushi Gilliam strain, checked tPA and PAI-1 by ELISA in culture supernatant. Then we observed the tissue factor expression on cultured endothelial cell monolayer by indirect IF stain. PAI-1 gene expression was evaluated by northern blot analysis. Results: 1) PAI-1 level showed gradual increase up to 240ng/ml (2.5-4.7 fold increase) in 24 hours. 2) tPA level showed no significant change with time. 3) PAI-1 gene expression increased 2.5 fold by northern blot analysis. 4) Tissue factor was expressed on the endothelial cells infected with R. tsutsugamushi. Conclusion: R. tsutsugamushi infection induces expression of tissue factor on endothelial cells and PAI-1 synthesis and it would contribute to DIC mechanism in tsutsugamushi disease in part. But it has no direct effect on tPA release.

Structural Dependence of the Physical Properties for Co2MnGa Heusler Alloy Films

R. J. Kim,이영백,이주열,K. K. Yu,K. W. Kim,남창우,V. A. Oksenenko,Y. J. Yoo,Y. V. Kudryavtsev 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3

In this study, Co2MnGa Heusler alloy (HA) ¯lms with signi¯cantly dierent structural orders were fabricated, and the in°uence of structural ordering on various physical properties was investigated. Co2MnGa ¯lms were deposited by °ash evaporation onto glass substrates at various substrate temperatures from 150 to 753 K. A disordered state of the ¯lms was achieved by using a vapor-quenching deposition at 150 K. Deposition at 623 K or post annealing of the disordered ¯lm at 728 K resulted in the formation of an intermediate structural order. As the substrate or the post-annealing temperature was decreased, a slight increase in the lattice constants was observed. We also found that the grain size increased in the ¯lms deposited at higher substrate temperatures. The ordered and intermediately ordered ¯lms exhibit ferromagnetic behavior and similar equatorial Kerr eect (EKE) spectra. Similar to the previously studied Ni-based HA ¯lms, the disordered ¯lm is nonmagnetic and has little EKE response. An annealing of the disordered ¯lm restores its crystalline structure and recovers the ferromagnetic order.

The partitioned-layer index: Answering monotone top-k queries using the convex skyline and partitioning-merging technique

Heo, J.S.,Whang, K.Y.,Kim, M.S.,Kim, Y.R.,Song, I.Y. North-Holland [etc ; Elsevier Science Ltd 2009 Information sciences Vol.179 No.19

A top-k query returns k tuples with the highest (or the lowest) scores from a relation. The score is computed by combining the values of one or more attributes. We focus on top-k queries having monotone linear score functions. Layer-based methods are well-known techniques for top-k query processing. These methods construct a database as a single list of layers. Here, the ith layer has the tuples that can be the top-i tuple. Thus, these methods answer top-k queries by reading at most k layers. Query performance, however, is poor when the number of tuples in each layer (simply, the layer size) is large. In this paper, we propose a new layer-ordering method, called the Partitioned-Layer Index (simply, the PL Index), that significantly improves query performance by reducing the layer size. The PL Index uses the notion of partitioning, which constructs a database as multiple sublayer lists instead of a single layer list subsequently reducing the layer size. The PL Index also uses the convex skyline, which is a subset of the skyline, to construct a sublayer to further reduce the layer size. The PL Index has the following desired properties. The query performance of the PL Index is quite insensitive to the weights of attributes (called the preference vector) of the score function and is approximately linear in the value of k. The PL Index is capable of tuning query performance for the most frequently used value of k by controlling the number of sublayer lists. Experimental results using synthetic and real data sets show that the query performance of the PL Index significantly outperforms existing methods except for small values of k (say, k=<9).

태양열 이용 냉난방 공조시스템 중 전열교환기 성능에 관한 연구

김광호(K.H.Kim),최광환(K.H.Choi),금종수(J.S.Kum),김보철(B.C.Kim),김종렬(J.R.Kim) 한국태양에너지학회 1999 한국태양에너지학회 논문집 Vol.19 No.4

본 논문은 태양열을 구동원으로 하고 액체흡수제인 염화리튬(LiCl) 용액을 이용하여 제습/냉방 및 난방을 하나의 시스템으로 이루는 태양열 이용 냉난방 공조시스템 중 여름철 전열교환기의 제습/냉방에 관한 성능실험 결과이다. 여름의 고온다습한 실내공기는 휀에 의해 전열교환기로 유입되어 충진층에서 살수된 LiCl 용액과 직접 접촉하여 제습/냉각된 후, 건조공기로 바뀌어 실내로 취출된다. 한편 수분을 흡수하여 저농도 용액으로 변한 LiCl 용액은 재생기에서 태양열에 의해 다시 고농도 용액으로 바뀌어 흡수포텐셜을 갖는다.<br/> 본 실험에서는 형상 및 크기가 다른 3가지 충진재를 사용하여 전열교환기으 제습성능을 비교하였으며, 절대습도기준 총괄 물질전달계수인 k_xa(kg/h·m3·??x)로써 그 성능을 평가하였다. 특히 k_xa값은 액체흡수제유량, 공기 풍량, 충진재 형상 및 충진층 높이에 따라 변한다. 따라서 이에 대한 영향을 조사하기 위하여 여러 가지 실험한 결과, 풍량은 k_xa값에 미치는 영향이 컸으나, 유량은 그다지 영향을 미치지 않음을 알 수 있었다. 또한 충진재의 형상에 따른 비교 실험에서 충진재의 직경이 큰 경우에는 충진층 높이의 영향이 컸으나, 직경이 작은 경우에는 높이에 의한 영향이 직경이 큰 경우보다 작았다. 이상의 실험 결과로부터 k_xa값을 충진재 형상 및 충진층 높이에 따라 정리하면 최적 전열교환기 설계 및 제작에 기초자료로 활용할 수 있음을 알았다. This report introduces a total heat exchanger in a solar air-conditioning system using Lithium Chloride (LiCl) solution. The hot and humid outside air is cooled and dehumidified by LiCl solution that is sprayed on the packed layer of the total heat exchanger. LiCl solution once diluted is concentrated again in a regenerator using solar energy.<br/> Three types as the packed materials were used in this experiment and the dehumidification performance was evaluated by the value of k_xa(kg/h·m3·?x), overall mass transfer coefficient based on a humidity ratio potential difference, the influence of inlet LiCI solution flow rate, air flow rate, packed layer height on k_xa was investigated. It was found that air flow rate, LiCl solution flow rate, packed layer height for all types had a great influnce on the value of k_xa.

망상내피계의 기능이 Cryptococcus Neoformans의 감염에 미치는 효과에 관한 실험적 연구

서강석,이중달,안도철,박영림,김익형 부산의대 1968 부산의대잡지 - 부산대학교 의과대학 Vol.8 No.1

Local Structural Changes Caused in Ni-Mn-Ga Alloy Films by Thermal Effects

이연승,K. K. Yu,Nina Lee,R. J. Kim,Y. J. Yoo,이영백,Y. V. Kudryavtsev 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3

The local structural changes of Ni-Mn-Ga alloy films were investigated, according to the deposition temperature, by using the Ni, the Mn, and the Ga K-edge X-ray absorption fine structure (XAFS) and glancing-angle X-ray diraction. The structural characters of the film deposited at 720 K are similar to those of bulk Ni2MnGa with a cubic L21 phase, and the film deposited onto a cooled substrate (s150 K) is in a disordered structure. After annealing, the structural changes in the films deposited at 150 K are as follows: the films annealed at temperatures below 440 K are in a disordered phase, the structural ordering starts in the films annealed at 520 K, at 600 K, the films become ordered, and at 680 K, the cubic L21 and the tetragonal phases coexist. By XAFS, the Ni, the Mn and the Ga atoms are found to be arranged as an ordered cubic L21 phase in the ordered film and as Ni-Mn-Ga alloy clusters in the disordered film.

Relationship between Stress Gene Polymorphisms and Litter Size by AI in Pigs

Jin, H.J.,Kim, I.C.,Wee, M.S.,Yeon, S.H.,Kim, C.D.,Lee, S.S.,Cho, C.Y.,Cho, S.R.,Son, D.S.,Park, C.K. 韓國受精卵移植學會 2007 한국동물생명공학회지 Vol.22 No.4

This study was performed to investigate the relationship between PSS-HSP70 gene polymorphism and artificial insemination (AI) reproductivity in the pigs. The RFLP polymorphism of PSS and the SSCP polymorphisms of HSP70 K1, K3 and K4 PCR product were detected different patterns. In the experiment for AI of fresh semen, spring and fall season showed higher litter size born of 10.89 head than 10.47 head of summer season. Landrace was showed higher litter size of 9.96 head than that of Duroc and Yorkshire (p<0.05). Stress relating PSS and HSP70 polymorphism of PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showd a highest litter size born of 10.97 head and litter size born alive of 10.69 head than that of the other polymorphisms(p<0.05). In the experiment for AI of frozen semen, effects of season and pig breeds were not showed for litter size born. The stress relating polymorphism of PSS-Carrier, HSP70 K1-BB, K3-BB, K4-AB showed highest litter size born of 11.29 head and litter size born alive of 10.82 head and PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showed the lowest litter size born of 8.48 head and litter size born alive of 7.33 head than that of the other polymorphisms(p<0.05). These results suggest that AI litter size born for the stress of forzen thawed semen may be affected by PSS and HSP70 polymorphism in pigs.

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.