• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.1-7
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• 2007

Backgound: It has been shown that the endothelium of cardiac valves and adjacent great vessels have a reduced immune reaction compared to other vessels. We investigated the clinical feasibility of using immunologically untreated xenogenic valves, in a pig-to-goat pulmonary valve conduit implantation model. Material and Method: Porcine pulmonary valve conduits were prepared without specific immunologic treatment and implanted into the right ventricular outflow tract of goats while undergoing cardiopulmonary bypass. Two goats each were assigned to the following observation time intervals: one day, one week, three months, six months and twelve months. Echo-cardiographic examinations were performed prior to sacrifice of the goat to evaluate pulmonary valve function. After the xenograft specimens were retrieved, histological changes were evaluated microscopically. Result: Ten of the twelve animals survived the predetermined observation time intervals. Aneurysmal dilatations, of the anterior wall of the implanted pulmonary artery, were observed at each of three and twelve month-survival animals. A variable degree of pulmonary valve regurgitation was observed on echocardiography. However, valve stenosis, thrombotic occlusion and vegetation were not seen. Microscopically, the nuclei of the donor tissue disappeared as a result of pyknosis and karyolysis; however the three components of the implanted xenografts (the pulmonary artery, the valve and the infundibulum) were gradually replaced by host cells over time, while maintaining their structural integrity. Conclusion: Immunologically untreated xenogenic pulmonary valve conduits were replaced by host cells with few observed clinical problems in a pig to goat pulmonary valve implantation model. Therefore, they might be an alternative bioprosthesis option.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.159-159
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• 2010

본 논문은 테라헤르츠 소스로 저온 InGaAs를 대체하기 위한 저온 $In_{0.64}Al_{0.36}Sb$의 실리콘(Si) 도핑 농도에 따른 광학적 특성 변화를 photoluminescence (PL)과 time-resolved PL (TRPL) 측정을 이용하여 분석하였다. $In_{0.64}Al_{0.36}Sb$ 시료는 분자선 엑피탁시 (molecular beam epitaxy)법으로 GaAs 기판 위에 약 $420^{\circ}C$에서 $3.7\;{\mu}m$ 두께 성장하였다. Si은 $In_{0.64}Al_{0.36}Sb$ 시료에서 도핑 농도가 낮을 때는 어셉터(acceptor)로 작용하다가 도핑 농도가 증가함에 따라 도너(donor)로 작용하였다. 본 연구에 사용한 $In_{0.64}Al_{0.36}Sb$ 시료의 Si 도핑 농도는 $4.5{\times}10^{16}\;cm^{-3}$ (n형), $4{\times}10^{16}\;cm^{-3}$ (n형), $8{\times}10^{15}\;cm^{-3}$ (n형), $1{\times}10^{15}\;cm^{-3}$ (p형), $4{\times}10^{14}\;cm^{-3}$ (p형)인 다섯 개의 시료를 사용하였다. Si 도핑한 시료의 PL 피크는 undoped 시료보다 약 100-200 nm 단파장에서 나타나고 PL 세기도 크게 증가하였다. 그러나 Si 도핑 농도가 가장 낮은 n형과 p형 시료의 PL 피크가 가장 짧은 파장 (높은 에너지)에 나타나고 도핑 농도가 증가함에 따라 장파장으로 이동함을 보였다. n형 시료의 도핑 농도가 $8{\times}10^{15}\;cm^{-3}$에서 $4.5{\times}10^{16}\;cm^{-3}$로 증가하였을 때 PL 피크는 1232 nm에서 1288 nm까지 장파장쪽으로 이동하였으며, p형 시료는 도핑 농도가 $4{\times}10^{14}\;cm^{-3}$에서 $1{\times}10^{15}\;cm^{-3}$로 증가하였을 때 PL 피크가 1248 nm에서 1314 nm로 이동함을 보였다. 또한 시료 온도에 따른 PL 결과는 온도가 증가함에 따라 PL 피크는 장파장으로 이동하면서 PL 세기는 급격하게 감소하고 약 100 - 150 K에서 소멸하였다. 그러나 ~1500 nm 이상 장파장 영역에 매우 넓은 새로운 피크가 나타났으며 온도가 증가함에 따라 PL 세기가 증가함을 확인하였다. Si 도핑 농도에 따른 운반자 수명시간 변화를 TRPL을 이용하여 측정하였다. 운반자 수명시간은 double exponential function을 이용하여 얻었다. Si 도핑 시료의 운반자 수명시간이 undoped 시료에 비해 매우 길게 나타났으며, Si 도핑 시료에서는 p형 시료들보다 n형 시료들의 운반자 수명시간이 길게 나타났다. PL 방출파장에 따른 운반자 수명시간은 Si 도핑 농도에 따라 다르게 나타났다. 이러한 PL과 TRPL 결과로부터 $In_{0.64}Al_{0.36}Sb$의 발광 특성 및 운반자 동역학은 Si 도핑에 크게 영향을 받는다는 것을 확인하였다.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.299-302
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• 2002

Selectins are differentially expressed carbohydrate binding proteins involved in the initiation of tissue inflammation by mediating the rolling and tethering of leukocytes on the vascular endothelium. This primary event in initiation of inflammation, as occurs during reperfusion injury, can be therapeutically targeted using selectin inhibitors, which generally block binding of sLex to E-, P-, and L-selectins. The objective of this study was to determine the role of selectins in renal ischemia/reperfusion injury after kidney transplantation. Canine kidneys were subjected to 60-min warm ischemia, flushed with UW solution, cold stored for 24 h, and autotransplanted into the nephrectomized donor. Renal autografts were monitored for 7 days by serum creatinine in the first study and by histology and myeloperoxidase activity after 4-hour reperfusion in the second study. In each study, one group of animals received TBC1269 (selectin inhibitor) and the other received saline vehicle. Serum creatinine rose quickly after transplantation and was not different between the groups. TBC1269 abolished a reperfusion-induced 2-fold increase in renal cortex neutrophil infiltration and improved histologic signs of ischemia after 4 hours of reperfusion. Selectin blockade does not improve the course of injury caused by warm renal ischemia. A minor benefit associated with the inhibition of early inflammation during reperfusion after kidney transplantation seems to occur.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.196-202
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• 2016

With increasing LM soybean import, the concern about unintentional gene flow from LM soybean to wild soybean and consequential weedy risk has been growing. Therefore, we conducted this study to characterize seed traits including germination of hybrids resulted from gene flow from LM soybean to wild soybean in comparison with their parents, LM soybean and wild soybean. Pollen-donor LM soybean seeds were much greater and heavier (about 15.0 g of 100 seed weight) than F2 hybrid (5.7 g), while pollen-recipient wild soybean and F1 hybrid seeds were smallest and lightest (about 2.5 g). F2 hybrid was brown, intermediate between yellow LM soybean seed and black wild soybean seed. These findings indicate that F1 hybrid seeds show similar characteristics with wild soybean, while F2 hybrid seeds show intermediate color and size between two parents. F2 hybrid seed showed intermediate traits between two parents in germination and dormancy rates, which were 35% and 65%, respectively. LM soybean showed no dormancy, while wild soybean showed greater than 90% dormancy. This finding indicates that F2 hybrid show intermediate characteristics in seed germination with high dormancy trait, suggesting a potential weediness of hybrids resulted from gene flow from LM soybean to wild soybean.

• Journal of Oriental Physiology
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• v.14 no.2 s.20
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• pp.179-187
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• 1999

To investigate how Jagamchotang provent cellular injury by a certain starting point on reperfusion injury after ischemia in myocardial cell, conducted MTT assay, LM stydy and measured LDH secretion, heart rate and nitric oxide(NO), and got the following results. 1. Jagamchotang did not injure cells even in $20{\mu}g/ml$. 2. Jaganchotang repressed the toxicity of mitochondria and cell membrane in reperfusing after ischemia and repressed the contraction of promontory of myocardial cell and reduction of the number of cells. Also maintained regular heart rate and reduced the number of heart rate. 3. Synthesis of NO by Jagamchotang in ischemia increased 1.9 times than a control. 4. When reperfusing with sodium nitropruside (SNO), NO donor in ischemia repressed the toxicity of mitochondria as the case of reperfusing with Jagamchotang in ischemia. Therefore, putting these findings together, it. can be said the effect of Jagamchotang in ischemia will be closely related with generation of NO.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.251-256
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• 1998

The effect of several factors on efficiency of anther culture of broccoli was studied. The medium supplemented with 14% sucrose, 125mg/L of silver nitrate and 0.1mg/L of each of NAA and 2,4-D was best in embryogenesis in all varieties tested. The effect of auxin was affected by silver nitrate, that is, it lowered embryogenesis when the concentration of NAA and 2,4-D was low, but it enhanced when their concentrations were high. Benzyl aminopurine increased embryogenesis in some varieties, but decreased in others. Although microspore embryogenesis was observed in anthers of which heigest was 1 to 0.6 - 1.0 of petal heigest in the bud, which corresponds to the early uninucleate to early binucleate stage of the microspores, it was much better when the ratio of heigest was 1 : 0.8. More embryos ware inducted from culture in March than in February in general. Because there was a big yearly variation, it was assumed that microspore embryogenesis was influenced greatly by the culture condition and the physiological condition of donor plants.

• 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.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.742-748
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• 1998

Experiments have been conducted to investigate synergistic effects and mechanisms of the Alaskan subbituminous coal/polypropylene (PP). Coliquefaction of coal/PP gave the synergistic effect in yields by 17% compared to independent liquefactions of coal or PP at $430^{\circ}C$. To analyse coliquefaction mechanisms, the second and zeroth order kinetic models were developed for coal and PP conversions respectively. When the models were simulated to fit coliquefaction results, those represented results successfully with the correlation coefficient of 0.99. The amount of tetralin needed to liquefy unit mass of coa 1(${\beta}$) was also calculated using the developed model. According to the calculated results, $\beta$ increased from 0.4 to 1.0 as the coliquefaction temperature increased from $410^{\circ}C$ to $470^{\circ}C$. This indicated that tetralin lowered the molecular weight of oil produced, and this phenomenon was recognized by the GPC analyses. Furthermore, it was found that tetralin prohibited the liquefaction of PP when coal was not added. On the other hand, tetralin was believed to act as a hydrogen-donor solvent to coal rather than prohibit PP liquefaction during coliquefaction. Therefore, the liquefaction rate of PP increases and synergistic effects in oil yields are mainly due to the increase in PP liquefaction during coal/PP coliquefaction.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.91-98
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• 2009

Object of this study were to determine the influence of collection times of rumen fluid on in vitro dry matter digestibility (IVDMD) of forage crops. The donor cow was fed concentrate once a day and given free access to grass-legume mixture hay. Main plot was consisted of different collection time of rumen fluid; T1: 1 hour before concentrate feeding, T2: 1 hour after feeding, T3: 4 hour after feeding and T4: 8 hour after feeding. A total of 7 samples of 4 different forage crops (barely, Italian ryegrass, crimson clover, rye) were used for the estimation of IVDMD and tested in three replicates. For the $DAISY^{II}$ incubation, each sample was inserted into each filter bag then heat-sealed and incubated in a digestion vessel for 48 h at $39^{\circ}C$. The times of rumen fluid collection had no significant effect on the IVDMD values over all varieties except for 2 breeds of IRG (Kogreen and Kospeed). IVDMD values with T1 over all varieties were slightly higher than other treatments, however those with both T1 of Kogreen and Kospeed varieties were significantly higher than T2 (p<.05).

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.111-116
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• 2000

Purpose : We reviewed the results of arthroscopic posterior cruciate ligament reconstruction using Achilles tendon allograft, and the efficacy of the surgical technique using gradual tibial tunneling and posterior transseptal technique. Materials and Methods : From september 1997 to September 1999, 8 patients with complete PCL injury were treated by arthroscopic PCL reconstruction using Achilles tendon allograft. Mean follow-up period was 21.7 months. Mean preoperative posterior laxity was 14mm. The clinical outcome was assessed by Telos stress test, Lysholm knee score and IKDC score. Result : There was no complication such as infection and neurovascular injury. Posterior translation using Telos device was less than 5mm in 6 cases$(75\%)$, and between 6 to 10mm in 2 cases$(25\%)$. The mean Lysholm knee score was 45 preoperatively and improved to 87 postoperatively. In IKDC system, 2 of 8 patients were group A and 6 were group B. Conclusion : Arthroscopic PCL reconstruction using achilles tendon allograft and posterior transseptal technique shows reliable stability, short operative time and minimizing donor site morbidity but needs more long term follow-up.