• 대한치과기공학회지
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• 제30권1호
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• pp.25-31
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• 2008

Cp-Ti and Ti-6Al-4V alloys commonly used dental implant materials, particularly for orthopaedic and osteosynthesis because of its suitable mechanical properties and excellent biocompatibility. This alloys have excellent corrosion behavior in the clinical environment. The first factor to decide the success of dental implantation is sufficient osseointegration and high corrosion resistance between on implant fixture and its surrounding bone tissue. In this study, in order to increase corrosion resistance and biocompatibility of Cp-Ti and Ti-6Al-4V alloy that surface of manufactured alloy was coated with TiN by RF-magnetron sputtering method. The electrochemical behavior of TiN coated Cp-Ti and Ti-6Al-4V alloy were investigated using potentiodynamic (EG&G Co, PARSTAT 2273. USA) and potentiostatic test (250mV) in 0.9% NaCl solution at 36.5 $\pm$ 1$^{\circ}C$. These results are as follows : 1. From the microstructure analysis, Cp-Ti showed the acicular structure of $\alpha$-phase and Ti-6Al-4V showed the micro-acicular structure of ${\alpha}+{\beta}$ phase. 2. From the potentiodynamic test, Ecorr value of Cp-Ti and Ti-6Al-4V alloys showed -702.48mV and -319.87mV, respectively. Ti-6Al-4V alloy value was higher than Cp-Ti alloy. 3. From the analysis of TiN and coated layer, TIN coated surface showed columnar structure with 800 nm thickness. 4. The corrosion resistance of TiN coated Cp-Ti and Ti-6Al-4V alloys were higher than those of the non-coated Ti alloys in 0.9% NaCl solution from potentiodynamic test, indicating better protective effect. 5. The passivation current density of TiN coated Cp-Ti and Ti-6Al-4V alloys were smaller than that of the noncoated implant fixture in 0.9% NaCl solution, indicating the good protective effect resulting from more compact and homogeneous layer formation.

• 공업화학
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• 제24권1호
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• pp.55-61
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• 2013

$Cp_2ZrCl_2$ 촉매를 Montmorillonite (MMT) 담체에 각기 다른 3가지 방법[MMT/$Cp_2ZrCl_2$, MMT/MAO/$Cp_2ZrCl_2$, MMT/(MAO + $Cp_2ZrCl_2$)]을 적용하여 불균일 촉매를 제조하였고, 이를 이용하여 에틸렌 중합 특성을 조사하였다. 유기점토인 30B-MMT에 담지한 불균일계 촉매가 자연점토인 $Na^+-MMT$에 담지한 촉매보다 높은 담지율을 나타내었고, 에틸렌 중합에서 높은 활성을 보였다. 이는 유기점토의 층간사이에 존재하는 하이드록시기가 MAO 및 촉매와의 화학적 결합을 유도한다고 할 수 있다. MMT에 직접 메탈로센을 담지하여 에틸렌 중합에 사용할 경우 균일계 촉매에 비해 낮은 활성을 보이지만, MMT를 MAO로 처리해서 만든 MMT/MAO/$Cp_2ZrCl_2$ 촉매에 MMAO의 조촉매를 사용하여 중합시에는 높은 활성을 나타내었다. MMT 담지촉매로 제조된 폴리에틸렌은 담지방법에 관계없이 균일계 촉매에 비해 높은 용융점, 분자량, 분자량 분포를 보였으며, 또한 입자형상에 있어 크기가 상당히 증가한 구형의 입자를 나타내었다. 또한 가장 안정적인 담지 반응과 높은 활성을 나타낸 30B-MMT/MAO/$Cp_2ZrCl_2$ 촉매로 최적의 중합조건을 찾기 위해 공정변수에 따라 에틸렌 중합을 수행하였다.

• 식물조직배양학회지
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• 제24권3호
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• pp.153-160
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• 1997

오이 모자이크바이러스(CMV, cucumber mosaic virus)는 작물의 생산량과 품질에 심각한 피해를 주기 때문에 외피단백질 유전자(CP, coat protein gene)를 도입하여 저항성 작물를 개발하고자 하였다. CMV CP유전자가 도입된 형질전환 담배 39 계통을 대상으로 오이모자이크바이러스 저항성을 검정하였다. 바이러스 저항성은 바이러스 감염으로 인한 생장 억제정도, 병징발현에 따른 잎모양의 변화로서 고도저항성, 저항성, 중간성, 감수성 등으로 판정하였고 39개 계통중 16 계통이 뚜렷한 바이러스 저항성을 보였다. 특히, 저항성 계통중 2 계통은 생장량과 잎모양에서 다른 저항성 계통보다 우수하여 고도저항성으로 세분하였다. 각 형질전환계통에서 CP단백질과 CP RNA 생성량을 조사하였는바, CP단백질 생합성은 대부분의 저항성과 감수성계통에서 검출되어 저항성과 특별한 관련을 인정할 수 없었으나 CP RNA는 대부분의 저항성 및 중간성 계통에서 다량 축적되는 경향을 보여 CP RNA가 저항성에 좀더 밀접함을 알수 있었다. 그러나 고도저항성 계통에서는 CP RNA가 검출되지 않아 저항성의 근원을 파악하기 위해서는 계속적인 연구가 요구된다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2018년도 춘계학술대회 및 임시총회
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• pp.11-11
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• 2018

Cryphonectria parasitica, chestnut blight fungus, has a characteristic of decreasing pathogenicity when infected with Cryphonectria hypovirus 1. C. parasitica is known to be one of the most representative model systems used to observe the interaction between viruses, plants and fungi. The mitogen-activated protein kinase (MAPK) pathway, which is well conserved in various organisms ranging from yeast to humans, functions in relaying phosphorylation-dependent signals within MAPK cascades to diverse cellular functions involved in the regulation of pheromone, cell wall integrity, and osmotolerance in filamentous fungi. Several genes in the MAPK pathway were revealed to be regulated by hypovirus, or to be involved in pathogenicity in C. parasitica. Among these pathways, the CWI pathway has aroused interest because CpBck1, an ortholog of yeast Bck1 (a CWI MAPKKK), was previously reported to be involved in cell wall integrity and sectorization. Interestingly, sporadic sectorization was observed in the CpBck1 mutant and sectored phenotypes were stably inherited in the progeny that were successively transferred from sectored mycelia. In this study, we analyzed the biological function of CpSlt2, downstream gene of CpBck1, to confirm whether the sectorization phenomenon occurred in the specific single gene or cell wall integrity (CWI) pathway. As results, the CpSlt2-null mutant exhibited marked changes in colonial growth, near absence of conidiation and aerial hyphae, abnormal pigmentation, CWI-related phenotypic defects, and dramatically impaired virulence. As cultivation of the mutant strains progressed, the majority of the colonies showed sporadic sectorization and mycelia from the sectored area stably maintained the sectored phenotype. These results suggest that the unique sectorization is CWI pathway-specific, though the components in the same CWI pathway have common and specific functions.

• 한국식품영양학회지
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• 제34권1호
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• pp.36-46
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• 2021

After ethanol (BM-E and RW-E) and hot-water (BM-HW and RW-HW) extracts were fractionated from two herbal mixtures (BM and RW), their physiological activities were investigated. All extracts consisted of more than 50% of neutral sugar, with their total polyphenol levels higher than flavonoid levels. Radical scavenging activities of EtOH extracts remained significantly higher compared to that of hot-water extracts, and in particular, RW-E showed consistently higher antioxidant activity than BM-E. When anti-inflammatory activities of the extracts were evaluated by LPS-stimulated RAW 264.7 cells at 10~500 μg/mL non-cytotoxicity doses, BM-E showed significantly higher levels of TNF-α, IL-1β, IL-6, and nitric oxide inhibitory activity than those of hot-water extracts and RW-E. Murine peritoneal macrophage cells were shown to be enhanced in crude polysaccharides (BM-CP and RW-CP fractionated from BM-HW and RW-HW) compared to hot-water extracts and polysaccharide K (PSK, positive control). Especially, RW-CP exhibited higher activity than BM-CP, and component sugar analysis showed that BM-CP mainly contained galacturonic acid, glucose, arabinose, galactose, and xylose (34.5%, 33.9%, 16.1%, 7.1%, and 6.3%, respectively), whereas RW-CP showed different measurements (29.5%, 59.2%, 5.0%, 4.5%, and 0.2%). In conclusion, two herbal mixtures could contain varying sets of physiological activities dependent on different extraction and fractionation methods.

• Applied Biological Chemistry
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• 제46권1호
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• pp.60-65
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• 2003

피부노화는 크게 생리적 노화(chmnological aging)와 광노화(photoaging)로 나누어 진다. 진피세포와 표피세포에서 광노화는 MMP(Matrix metalloproteinase)의 분비량이 증가하면서 MMP와 TIMP(Tissue inhibitors of metalloproteinase)의 균형을 깨뜨려 진피층을 붕괴가 유도된다. 본 연구는 광노화 및 암 전이 과정, 관절염 등 여러 질병에서 주목받고 있는 MMP-1의 생성 억제활성물질을 120여종의 식용식물(edible plants)로부터 활성물질을 분리, 정제하고 정제물질의 일부 물리화학적 성질을 규명하였다. 표피세포(HaCaT)와 진피세포(HS68) 세포주를 이용하여 다양한 강도의 UVB를 조사하여 생성되는 MMP-1의 양과 감수성을 검토한 결과 HS68에서 UVB의 조사량에 비례하여 MMP 분비량이 증가되는 반면, HaCaT세포의 MMP 분비량은 유의적 차이를 보이지 않았다. MMP-1 생성량이 가장 높은 UVB 조사량은 35 $mJ/cm^2$ 내외이었고, UVB조사 후 분비되는 MMP-1의 양은 36-48시간대에 가장 높게 나타났다. MMP-1의 생성 억제활성을 검색한 결과 아가위(Crataegus pinnatifida Bunge)의 냉수분획층(CP)에서 최대활성을 나타내었다. CP를 periodate 산화 처리에서는 변화가 없으나 pronase 처리시 활성이 감소되는것으로 단백질이 활성의 본체임을 확인하였다. 정제는 CP의 ultrafiltration처리, DEAE-Tayopearl 650c, Butyl-Tayopearl 650M의 이온교환크로마토그래프와 Bio-Gel P-30겔 여과 크로마토그래프 통해서 MMP-1 억제 활성 분획층 CP-2Va-2를 정제하였다. CP-2Va-2의 MMP-1억제활성은 88.5%이었으며, 분자량은 HPLC로 확인한 결과 19kDa, SDS-PAGE에서는 20 kDa 확인됨으로써 monomer구조임을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.224-233
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• 2012

The limiting sequence and relative ratio of lysine (Lys), methionine (Met), and threonine (Thr) for calves about 2 mo of age fed milk replacers (MR) containing soy protein are not clearly defined. The objective of the study was to investigate the effect of supplementing MR containing 22% CP, half from soy protein concentrate (SPC, 40.56% CP, flour) and half from whey proteins, with Lys, Met, and Thr to estimate amino acid (AA) sequence and their relative ratio for calves about 2 mo of age. A method of partial deduction of AA was adopted. Twenty-four newborn calves (half males and half females, $40.7{\pm}0.9$ kg of BW) were fed 1 of 4 MR diets for 56 d (n = 6/diet). The diets were supplemented with all (positive control) or with 2 of the 3 AAs: Lys, Met and Thr, (i.e., PC (22% CP, 2.34% Lys, 0.72% Met and 1.80% Thr), PC-Lys (22% CP, 1.64% Lys, 0.72% Met and 1.80% Thr), PC-Met (22% CP, 2.34% Lys, 0.50% Met and 1.80% Thr), and PC-Thr (22% CP, 2.34% Lys, 0.72% Met and 1.26% Thr)). Calves were fed thrice daily; starter (20% CP, 1.03% Lys, 0.30% Met and 0.69% Thr), hay (3.23% CP, 0.29% Lys, 0.12% Met and 0.23% Thr) and water were offered free choice. Starter and hay were only offered beginning on d 36 (after 5 wk) and d 43 (after 6 wk), respectively. BW, body size and blood samples measures were taken every two weeks. Three-day total collection of feed refusals, feces, and urine were recorded starting at d 33 and d 54 of age, respectively. From the results, the limiting sequence and relative ratio between the 3 AAs in calves with different diet structures were calculated. The limiting sequence of the 3 AAs were ranked as Lys, Met and Thr; the proper ratio was 100:29:70 for MR-only diet and 100:30:60 for diets consisted of MR, starter and hay. Nitrogen digestion and utilization and nutrient digestibility were negatively affected by AA deletion treatments. From the evidence of this experiment, it did not appear that the AA limiting sequence was selectively altered by differences in diet structures such as would be encountered in practice. The relative ratio between the 3 AAs varied with the offer of starter and hay to calves, and the average ratio was 100:29.5:65 for calves during 2 to 10 wk of age.

• Journal of Animal Science and Technology
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• 제62권2호
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• pp.198-207
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• 2020

This experiment was performed to evaluate the optimal proportion of dietary standardized ileal digestible lysine (SID Lys) to net energy (NE) proportion in growing to finishing pigs. A total of seventy-two pigs were used at phase 1 (initial body weight 37.23 ± 0.23 kilogram, for 42 d) and at phase 2 (initial body weight 54.16 ± 0.20 kilogram, for 77 d). They were arbitrarily assigned to three treatments groups consisting of four duplicates per treatment (six pigs in duplicates, respectively). Diet treatments were as follows: CON = basal diets (phase 1, crude protein (CP): 19.1%; SID Lys: 0.94%; SID Lys: NE proportion: 0.91 g/MJ / phase 2, CP: 17.0%; SID Lys: 0.84%; SID Lys: NE proportion: 0.79 g/MJ), TRT1 (phase 1, CP: 18.0%; SID Lys: 0.92%; SID Lys: NE proportion: 0.89 g/MJ / phase 2, CP: 15.8%; SID Lys: 0.8%; SID Lys: NE proportion: 0.75 g/MJ), TRT2 (phase 1, CP: 17.3%; SID Lys: 0.82%; SID Lys: NE proportion: 0.79 g/MJ / phase 2, CP: 14.8%; SID Lys: 0.7%; SID Lys: NE proportion: 0.65 g/MJ). In phase 1 and 2, growth performance did not meaningfully be affected when SID Lys: NE proportion decreased with reducing CP content. In phase 2, the nitrogen digestibility of CON group in 11 week was higher (p < 0.05) than other treatments. Also, marbling and firmness scores of TRT2 group diets increased (p < 0.05) compared with those of CON group, but dissimilarities of other meat qualities did not be detected among treatments. In conclusion, introduction of NE system can reduce negative problems introduced when dietary CP decreased. Also, 0.79 and 0.65 g/MJ of SID Lys: NE proportion is the optimal Lys: NE proportion to achieve improved pork quality without impairing the growth performance in growing-finishing pigs, respectively.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.427-433
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• 2012

The present study was performed to investigate long-term effects of the low-crude protein and lysine (low CP/lys) diet and a yeast culture supplemented to the low CP/lys diet on growth and carcass characteristics in growing-finishing pigs. Forty-five gilts and 45 barrows weighing approximately 25 kg born to Yorkshire ${\times}$ Landrace dams and Duroc sires were allocated to nine pens, with five gilts and five barrows assigned per pen. Every three pens received CP/lys-rich grower and finisher diets (control), low CP/lys grower and finisher (basal), or the low CP/lys grower and finisher supplemented (2%) with a yeast culture providing $3.2{\times}10^8$ Saccharomyces cerevisiae cells/kg diet (yeast) for 31 and 79 days, respectively. The ADG was less in the low CP/lys (basal + yeast) group than in the control group (P<0.01) during both grower (0.59 vs. 0.70 kg) and finisher (0.75 vs. 0.89 kg) phases. However, marbling score was greater (P<0.05) in the low CP/lys group vs. control (3.86 vs. 3.12) at slaughter, which resulted in a twice percentage of the $1^+$-quality grade carcasses in the former compared with that for the latter. Supplementation of the yeast culture to the basal diet caused a decrease in ADG during the grower phase (P<0.01), but not during the finisher phase (0.64 vs. 0.53 kg and 0.73 vs. 0.77 kg for the basal vs. yeast group during the grower and finisher phases, respectively), without influencing the marbling score or percentage of the $1^+$-quality grade carcasses. In conclusion, results indicate that long-term provision of the low CP/lys diet has a beneficial effect on marbling and carcass quality grade as well as a negative effect on weight gain and that the yeast culture supplemented to the low CP/lys diet has no beneficial effect on weight gain or carcass quality.

• Journal of Genetic Medicine
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• 제6권1호
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• pp.1-7
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• 2009

프로모터 CpG island 과메틸화와 히스톤 변경으로 대변되는 후성유전적 변화는 거의 모든 종류의 암에서 발견되는 중요한 발암기전이다. 인간유전자의 60-70% 가량이 프로모터에 CpG islands를 가지고 있으며, 이 유전자들 중 일부가 과메틸화됨으로써 해당유전자의 발현이 차단되고, 종양억제기능이 소실되어 종양세포의 성장을 촉진하게 된다. 암에는 프로모터 CpG island 과메틸화라는 국소적 변화 이외에, 유전체 전반에 걸친 탈메틸화를 동시에 보이는 경우가 대부분인데, 이러한 유전체 저메틸화는 염색체 불안정성과 밀접한 연관관계가 있다. 국소적 과메틸화와 전반적인 저메틸화라는 이러한 상반된 DNA 메틸화 변화는 암세포뿐만 아니라 그 전단계 병변인 이 형성 병변에서도 관찰된다. 프로모터CpG island 과메틸화는 유전자 발현억제 기전으로서의 중요성뿐만 아니라 종양표지자로서의 중요성이 부각되고 있다. 즉, 정상세포에서는 관찰되지 않으면서 암세포에서만 관찰되는 프로모터 CpG island 과메틸화는 암세포의 바이오마커로서의 가치가 있으며, 이를 이용하여 체액에서 암을 진단하려는 시도들이 이루어지고, 이를 활용한 암의 분자진단방법이 개발되고 있다. 또한 이러한 DNA 메틸화는 암환자의 예후 판정이나 항암치료제의 감수성 결정 등에 활용되고 있다. 본 원고에서는 인체 암세포에서의 DNA 메틸화 변화에 관하여 소개하고자 한다.