• Korean Journal of Materials Research
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• v.9 no.7
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• pp.753-759
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• 1999

The microstructure and electrical properties of ZNR that W $O_3$ is added in the range 0.5~4.0mol%, were investigated. The major part of W $O_3$ were segregated at the nodal point and W-rich phase was formed. Three crystalline phases, such as W-rich phase (W $O_3$), Bi-rich phase (B $i_2$W $O_{6}$ ), and spinel phase (Z $n_{2.33}$S $b_{0.67}$ $O_4$) were confirmed to be co-existed at the nodal point The average grain size increased in the range 15.5~29.9$\mu\textrm{m}$ with increasing W $O_3$ additive content. Consequently. W $O_3$ acted as a promotion additive of grain growth. As the W $O_3$ additive content increases. the varistor voltage and the nonlinear exponent decreased in the range 186.82~35.87V/mm and 20.90~3.34, respectively, and the leakage current increased in the range of 22.39~83.01 uh. With increasing W $O_3$ additive content, the barrier height and the density of interface states decreased in the range 1.93~0.43eV and (4.38~1.22)$\times$10$^{12}$ $\textrm{cm}^2$, respectively. W $O_3$ acted as an acceptor additive due to the donor concentration increasing in the range (1.06~0.38)$\times$10$^{18}$ /㎤with increasing W $O_3$ additive content.t.t.

• Journal of Chest Surgery
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• v.30 no.1
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• pp.1-10
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• 1997

The successful cardiac transplantation depends partly on the donor heart preservation by a solution that will ensure recovery of myocardial function. The purpose of this study was to perform the evaluation of various preservation solutions and to accumulate the data on the requisites for ideal preservation solution. The experimental setup was the constant pressure Langendorffs perfusion system. Isolated rabbit hearts were perfused for 20minutes with unarm Krebs-Henseleit solution, stored for 4 hours in cold preservation solution after cardioplegia, and then were reperfused for 20minutes. The 4 experimental groups were prepared Hartmann's solution group (group 1, control), modified Euro-collins solution group(group II. MEC), modified University of Wisconsin group (group n, MUW), and CK solution(made by the author) group (group W, CK). The parameters for assessing the preservation ability were levels of enzymes in freezed myocardial tissues (lactate, creatine kinase-MB and adenosine deaminase), coronary flow. left ventricular developing pressure and dpldt. In conclusion, the ability of preservation for isolated rabbit heart was excellent in CK solution and modified University of Wisconsin solution, and poor in modified Euro-collins solution, compared with Hartmann solution. CK solution has low potassium concentrations(34.2mEq/L) and includes various substrates to be salutary on myocardial preservation. This fact may indicates the necessity of further refinements in selection or composition of electrolytes and substrates.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.624-631
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• 2014

In this study, a new series of conjugated polymer 3-(5-(5,6-bis(octyloxy)-7-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-10-(4-(octyloxy)phenyl)-10H-phenothiazine (P1) and 3-(5-(5,6-bis(octyloxy)-7-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-4-yl)thiophen-2-yl)-10-(4-((2-ethylhexyl)oxy)phenyl)-10H-phenothiazine (P2) were synthesised and organic photovoltaics (OPVs) properties were characterized. The push-pull structure polymer consisted of phenothiazine derivative as an electron donor and benzothiadiazole derivative as an electron acceptor. The aliphatic chain substituted aromatic ring was substituted at the position of N in phenothiazine for the electron-rich and improved solubility. Excellent thermal stabilities of P1 and P2 were confirmed by measured Td values as 321.9 and $323.7^{\circ}C$, respectively and the degrees of polymerization were 4,911 (P1) and 5,294 (P2). The maximum absorption wavelength of P1 and P2 were 549 and 566 nm, respectively. The device was fabricated and the OPVs property was measured. As a result, the power efficiency of conversion for P1 and P2 were 0.96 and 0.90%, respectively.

• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.18-18
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• 2003

Thioredoxin (Trx) is a small redox protein that is ubiquitously distributed from achaes to human. In diverse organisms, the protein is involved in various physiological roles by acting as electron donor and regulators of transcription and apoptosis as well as antioxidants. Sequences of Trx within various species are 27～69% identical to that of E. coli and all Trx proteins have the same overall fold, which consists of central five β strands surrounded by four α helices. The N-terminal cysteine in WCGPC motif of Trx is redox sensitive and the motif is highly conserved. Compared with general cysteine, the N-terminal cysteine has low pKa value. The result leads to increased reduction activity of protein. Recently, novel thio.edoxin-related protein (TRP14) was found from rat brain. TRP14 acts as disulfide reductase like Trx1, and its redox potential and pKa are similar to those of Trx1. However, TRP14 takes up electrons from cytosolic thioredoxin reductase (TrxR1), not from the mitochondrial thioredoxin reductase (TrxR2). Biological roles of TES14 were reported to be involved in regulating TNF-α induced signaling pathways in different manner with Trx1. In depletion experiments, depletion of TRP14 increased TNF-α induced phosphorylation and degradation of IκBα more than the depletion Trx1 did. It also facilitated activation of JNK and p38 MAP kinase induced by TNF-α. Unlike Trx1, TRP14 shows neither interaction nor interference with ASK1. Here, we determined three-dimensional crystal structure of TRP14 by MAD method at 1.8Å. The structure reveals that the conserved cis-Pro (Pro90) and active site-W-C-X-X-C motif, which may be involved in substrate recognition similar to Trx1 , are located at the beginning position of strand β4 and helix α2, respectively. The TRP14 structure also shows that surface of TRP14 in the vicinity of the active site, which is surrounded by an extended flexible loop and an additional short a helix, is different from that of Trx1. In addition, the structure exhibits that TRP14 interact with a distinct target proteins compared with Trx1 and the binding may depend mainly on hydrophobic and charge interactions. Consequently, the structure supports biological data that the TRP14 is involved in regulating TNF-α induced signaling pathways in different manner with Trx1.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.121-130
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• 1993

The GaP crystals were grown by synthesis solute diffusion method and its properties were investigated. High quality single crystals were obtained by pull-down the crystal growing ampoule with velocity of 1.75mm/day. Etch pits density along vertical direction of ingot was increased from 3.8 ${\times}{10^4}$c$m^{-2}$ of the first freeze to 2.3 ${\times}{10^5}$c$m^2$ of the last freeze part. The carrier concentration and mobilities at room temperature were measured to 197.49cc$m^2$/V.sec and 6.75 ${\times}{10^{15}}$c$m^{-3]$, respectively. The temperature dependence of optical energy gap was empirically fitted to $E_g$(T)=[2.3383-(6.082${\times}{10^{-4}}$)$T^2$/(373. 096+TJeV. Photoluminescence spectra measured at low temperature were consist with sharp line-spectra near band-gap energy due to bound-exciton and phonon participation in band edge recombination process. Zn-diffusion depth in GaP was increased with square root of diffusion time and temperature dependence of diffusion coefficient was D(Tl = 3.2 ${\times}{10^3}$exp( - 3.486/$k_{\theta}$T)c$m^2$/sec. Electroluminescence spectra of p-n GaP homojunction diode are consisted with emission at 630nm due to recombination of donor in Zn-O complex center with shallow acceptors and near band edge emission at 550nm. Photon emission at current injection level of lower than 100m A was due to the band-filling mechanism.

• Journal of Life Science
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• v.23 no.11
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• pp.1342-1350
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• 2013

We examined the effect of hydrogen sulfide ($H_2S$) in chemical hypoxia-induced injury in mouse hepatocytes. Cell viability was significantly decreased by cobalt chloride ($CoCl_2$), a well-known hypoxia mimetic agent in a time- and dose- dependent manner. Sodium hydrosulfide (NaHS, a donor of $H_2S$) pretreatment before exposure to $CoCl_2$ significantly attenuated the $CoCl_2$-induced decrease of cell viability. $CoCl_2$ treatment resulted in an increase of intracellular ROS generation, which is inhibited by NaHS or N-acetyl-cysteine (NAC, a ROS scavenger), and p38 MAPK phosphorylation, which is also blocked by NaHS or NAC. The $CoCl_2$-induced increase of the Bax/Bcl-2 ratio was attenuated by NaHS, NAC, and SB 203580 (p38 MAPK inhibitor). The $CoCl_2$-induced decrease of cell viability was also attenuated by NaHS, NAC, and SB 203580 pretreatment. Additionally, NaHS inhibited the $CoCl_2$-induced COX-2. Similar to the effect of NaHS, NAC blocked $CoCl_2$-induced COX-2 expression. Furthermore, NS-398 (a selective COX-2 inhibitor) attenuated not only the $CoCl_2$-induced increase of the Bax/Bcl-2 ratio, it also decreased cell viability. Taken together, $H_2S$ protects primary cultured mouse hepatocytes against $CoCl_2$-induced cell injury through inhibition of the ROS-activated p38 MAPK cascade and the COX-2 pathway.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.87-92
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• 2012

We constructed the fibroin H-chain expression system to produce Discosoma sp. red fluorescent protein variant2 (DsRed2) in transgenic silkworm cocoon. Fluorescent cocoon could be made by fusing DsRed2 cDNA to the heavy chain gene and injecting it into a silkworm. The DsRed2 fusion protein, each with N- and C-terminal sequences of the fibroin H-chain, was designed to be secreted into the lumen of the posterior silk glands. The expression of the DsRed2/H-chain fusion gene was regulated by the fibroin H-chain promoter. The use of the 3xP3-driven EGFP cDNA as a marker allowed us to rapidly distinguish transgenic silkworms. The EGFP fluorescence became visible in the ocelli and in the central and peripheral nervous system on the seventh day of embryonic development. A mixture of the donor and helper vector was micro-injected into 1,020 Kumokjam, bivoltin silkworm eggs. We obtained 6 broods. The cocoon was displayed strong red fluorescence, proving that the fusion protein was present in the cocoon. Accordingly, we suggest that the DsRed2 fluorescence silk will enable the production of novel biomaterial based on the transgenic silk.

• Tuberculosis and Respiratory Diseases
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• v.82 no.4
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• pp.348-356
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• 2019

Background: Recently, the number of lung transplants in South Korea has increased. However, the long-term outcome data is limited. In this study, we aimed to investigate the long-term outcomes of adult lung transplantation recipients. Methods: Among the patients that underwent lung transplantation at a tertiary referral center in South Korea between 2008 and 2017, adults patient who underwent deceased-donor lung transplantation with available follow-up data were enrolled. Their medical records were retrospectively reviewed. Results: Through eligibility screening, we identified 60 adult patients that underwent lung (n=51) or heart-lung transplantation (n=9) during the observation period. Idiopathic pulmonary fibrosis (46.7%, 28/60) was the most frequent cause of lung transplantation. For all the 60 patients, the median follow-up duration for post-transplantation was 2.6 years (range, 0.01-7.6). During the post-transplantation follow-up period, 19 patients (31.7%) died at a median duration of 194 days. The survival rates were 75.5%, 67.6%, and 61.8% at 1 year, 3 years, and 5 years, respectively. Out of the 60 patients, 8 (13.3%) were diagnosed with chronic lung allograft dysfunction (CLAD), after a mean duration of $3.3{\pm}2.8years$ post-transplantation. The CLAD development rate was 0%, 17.7%, and 25.8% at 1 year, 3 years, and 5 years, respectively. The most common newly developed post-transplantation comorbidity was the chronic kidney disease (CKD; 54.0%), followed by diabetes mellitus (25.9%). Conclusion: Among the adult lung transplantation recipients at a South Korea tertiary referral center, the long-term survival rates were favorable. The proportion of patients who developed CLAD was not substantial. CKD was the most common post-transplantation comorbidity.

• Journal of Embryo Transfer
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• v.22 no.2
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• pp.89-95
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• 2007

The present study was conducted to examine some factors affecting in vitro development and fecundity of embryos recloned with somatic cell nuclear transfer (SCNT). Fibroblast cells retrieved from the ear of a 3-week-old, cloned Korean goat (Jinsoonny) were used as karyoplast donors and serum-starvation was conducted in tissue culture medium (TCM)-199 supplemented with 0.5% FBS. Recipient oocytes were surgically collected by flushing the oviducts 35 h after hCG injection following FSH priming. The zonae pellucidae of the oocytes were partially perforated with a laser drill and a donor cell was transferred into an enucleated oocyte. The couplets were electrically fused and activated by ionomycin (5 min) and 6-DMAP (4 h). The reconstructed embryos were cultured in mSOF medium containing 0.8% BSA at $39^{\circ}C$ in an atmosphere of 5% $CO_2$, 5% $%O_2$, 90% $N_2$ for 12 to 15 h. Re-cloned embryos (2- to 4-cell stages) were surgically transferred into the oviducts of the recipients and pregnancy was subsequently diagnosed by progesterone assay and ultrasound on Days 21 and 63 of pregnancy. The fusion rate following 1st fusion pulse was higher (p<0.05) in 2nd cloning (65.9%) compared to 1st cloning (51.0%), but it was not different in the other groups. The rate of cleavage after fusion was significantly higher (p<0.05) in 1st (77.7%) than in 2nd cloning (56.0%). A total of 175 re-cloned embryos were transferred into 28 recipients. On day 21 and 60 after transfer, 11 (39.3%) and 4 recipients (17.4%) were pregnancy, respectively. In comparison of pregnancy rate by estrous synchronization, a total of 66 and 109 re-cloned embryos were transferred into 11 recipients in natural estrus and 17 recipients in induced estrus, respectively. Five (45.4%) and 2 recipients (18.2%) in natural estrus were pregnant on days 21 and 63 while 6 (35.3%) and 2 (11.8%) recipients in induced estrus were pregnant, respectively. These results show that recloning of goat can be achieved by SCNT and estrous synchronization between donor and recipient animals may be one of the major factors affecting success rate.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.127-132
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• 2004

This study was conducted to examine the effects of electric stimulation conditions on in vitro developmental ability of caprine embryos after somatic cell nuclear transfer. Recipient oocytes were surgically collected after superovulation by using CIDR and FSH, PMSG, hCG and estrous synchronization in Korean native goats. The caprine ear cells were cultured in vitro in serum-starvation condition (TCM-l99 + 0.5% FBS) for 3 to 5 days of cell confluence. The zona pellucida of in vivo and in vitro matured oocytes were partially drilled using laser system. Single somatic cell was individually transferred into the enucleated oocyte. The reconstructed oocytes were electrically fused with 0.3M mannitol. After the electofusion, embryos were activated by electric stimulation or Ionomycin + 6-DMAP. Nuclear transfer embryos were cultured in mSOF medium supplemented with 0.8% BSA 6∼7 days at 39 , 5% $CO_2$, 5% $O_2$, 90% $N_2$. The fusion rate of donor cells was 60.4% and 40.3 % in ear cell and fetal fibroblast, and cleavage rate were 40.6% and 48.2%, respectively. No significant difference was found in the fusion and cleavage rate in different donor cells. Nuclear transferred oocytes were fused by electric pulses of 1.30∼1.40, 2.30∼2.39 and 2.40∼2.46 ㎸/cm. There was no significant difference among different electric pulses in fusion rates (26.7, 34.8 and 43.8%). The cleavage rate was higher (p<0.05) in 1.30∼1.40 ㎸/cm (82.9%) than 2.30∼2.39 ㎸/cm (43.8%) and 2.40∼2.46 ㎸/cm. (51.8%). The fusion rates of recipient oocyte source were 1st (43.5% and 23.6%), 2nd (55.7％ and 39.2%) and 3rd (66.1% and 52.8%) in in vivo and in vitro oocytes. However, fusion ratee were significantly higher (p<0.05) in in vivo than in vitro oocyte. The cleavage rate of fused oocytes from in vivo and in vitro sources were 52.6% and 54.4%, respectively. No significant difference was found in the cleavage rate according to the recipient oocyte source. These results suggest that factors such as field pulse of electric stimulation and oocyte source could affect in vitro developmental ability of nuclear transplanted caprine oocytes.