• 한국재료학회지
• /
• 제4권7호
• /
• pp.808-816
• /
• 1994

본 연구에서는 안정제를 이용하는 반회분식 분산 중합(semi batch dispersion polymerization)공정으로 전도성 고분자인 p-Doped polypyrrole 입자를 제조하였다. 반회분식 분산 중합은 단량체를 monomer starved 조건하에서 연속 주입하여 중합시키는 방법으로써 polyvinylalcohol(PVA)을 안정제로 사용한 경우 평균 50nm, methylcellulose를 안정제로 사용한 경우평균 95nm 정도의 입자 크기를 갖는 dispersion을 제조할 수 있었으며, 이의 입자 크기 및 전도도는 단량체 투입 속도, 개시제 농도와 안정제의 종류, 분자량 및 농도에 따라 변화하였다. 이는 도입 성분중 개시제와 안정제의 역할(친수성 정도, 분자량)에 따라 달라지는 것으로, 이에 따른 물성의 최적점을 찾을 수 있었다.

• Nutritional Sciences
• /
• 제5권4호
• /
• pp.175-183
• /
• 2002

To compare the effects of various types of dietary fiber on microbial production of short-chain fatty acids (SCFA) and on colon cell proliferation which is used as an intermediate biomarker for colon carcinogenesis, groups of 10 male Sprague-Dawley rats were fed one of four fiber-supplemented diets (6% cellulose, 6% pectin, 6% polydextrose, and a mixture of 3% cellulose and 3% polydextrose) for three weeks. As a control, a fiber-free diet was fed to a separate group of 10 rats. Cell proliferation was measured by in vivo incorporation of bromodeoxyuridine into DNA in the proximal and distal colon, respectively. Luminal concentrations of SCFA were measured by gas chromatography. Dietary fiber significantly influenced microbial production of SCFA in the colon; pectin supplementation produced the highest concentrations of luminal SCFA in both the proximal and distal colon (p<0.05). The degree of individual SCFA production was characterized by a relatively higher increase in butyrate production by the pectin-supplemented diet, and in propionate production by the polydextrose-supplemented diet, resulting in alterations of the molar ratios of acetate, propionate and butyrate. There were significant differences in colon cell proliferation among the diet groups; the pectin-supplemented diet produced a significantly higher effect on cell proliferation of distal colonic epithelial cells (p＜0.05), and the polydextrose-supplemented diet produced an intermediate effect compared to the fiber-free or cellulose-supplemented diet. Increased cell proliferation was correlated to increased luminal concentrations of butyrate in the proximal colon and to increased luminal concentrations of propionate and butyrate in the distal colon (p<0.05). Therefore, these data suggest that dietary fiber may modulate colon cell proliferation by altering luminal SCFA concentrations, particularly butyrate and perhaps propionate. In addition, the present study is the first finding that has demonstrated a relative increase in colon cell proliferation due to supplementation with polydextrose, suggesting that the overuse of this artificially synthesized polysaccharide in food processing technology needs to be carefully evaluated from the public health point of view.

• 한국잡초학회지
• /
• 제9권3호
• /
• pp.238-244
• /
• 1989

신규(新規) 제초제(除草劑)에 dithiopyr의 제초효과(除草效果) 변화(變化)에 미치는 각종(各種) 재배(栽培) 화경조건(環境條件)의 영향(影響)에 대하여 조사(調査)한 바 다음과 같은 결과(結果)를 얻었다. Dithiopyr는 추천약량(推薦藥量)의 1/3수준(水準)인 0.04kg a.i./ha 약량(藥量)에서도 피, 물달개비 등에 대하여 89.3% 이상의 효과(效果)가 있었고, 0.08kg a.i./ha 약량(藥量) 이상부터는 100%의 방제율(防除率)을 보였다. 제초효과(除草效果)는 토성(土性), 누수량(漏水量), 온도(溫度), 담수심(湛水深), 관수시간(換水時間)의 차이(差異)에 따른 영향을 거의 받지 않았다. 제초효과(除草效果)는 이앙전(移秧前) 처리(處理) 혹은 이앙(移秧) 후(後) 12일 이상(以上)의 처리(處理)보다는 5-8일 처리(處理)가 높았다.

• Journal of Microbiology and Biotechnology
• /
• 제21권7호
• /
• pp.679-685
• /
• 2011

Xanthomonas oryzae pv. oryzae (Xoo) produces a putative effector, XoAvrBs2. We expressed XoAvrBs2 homologously in Xoo with a TAP-tag at the C-terminus to enable quantitative analysis of protein expression and secretion. Addition of rice leaf extracts from both Xoo-sensitive and Xoo-resistant rice cultivars to the Xoo cells induced expression of the XoAvrBs2 gene at the transcriptional and translational levels, and also stimulated a remarkable amount of XoAvrBs2 secretion into the medium. In a T3SS-defective Xoo mutant strain, secretion of the TAPtagged XoAvrBs2 was blocked. Thus, we elucidated the transcriptional and translational expressions of the XoAvrBs2 gene in Xoo was induced in vitro by the interaction with rice and the induced secretion of XoAvrBs2 was T3SSdependent. It is the first report to measure the homologous expression and secretion of XoAvrBs2 in vitro by rice leaf extract. Our system for the quantitative analysis of effector protein expression and secretion could be generally used for the study of host-pathogen interactions.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권9호
• /
• pp.1407-1416
• /
• 2007

Ten, first lactation, 87.5%HF dairy cattle were used to investigate effects of long-term administration of recombinant bovine somatotropin (rbST) on nutrient uptake by the mammary gland at different stages of lactation. Measurements of arterial plasma concentrations and arterial-venous differences of metabolites across the mammary gland were performed in combination with measurment of mammary blood flow to estimate the mammary uptake. Animals in experimental groups were injected subcutaneously every 14 days from day 60 of lactation with a prolonged-release formulation of 500 mg of rbST (POSILAC, Monsanto, USA) or with sterile sesame oil without rbST in the control group. During early lactation, the milk yield of rbST-treated animals was higher than that of the control animals (p<0.05). The peak milk yield in both groups of animals declined from the early period of lactation with progression to mid- and late-lactation. No significant changes were observed in the concentration of milk lactose, while the concentrations of milk protein significantly increased as lactation advanced to mid- and late-lactation in both groups. Milk fat concentrations were significantly higher in rbST-treated animals than in control animals, particularly in early lactation (p<0.05). Mammary blood flow (MBF) markedly increased during rbST administration and was maintained at a high level throughout lactation. The mean arterial plasma concentrations for glucose and acetate of rbST-treated animals were unchanged. The net mammary glucose uptake of rbST-treated animals increased approximately 20% during early lactation, while it significantly decreased (p<0.05), including the arteriovenous differences (A-V differences) and extraction ratio across the mammary gland, as lactation advanced to mid- and late-lactation. A-V differences, mammary extraction and mammary uptake for acetate increased during rbST administration and were significantly higher (p<0.05) than in the control animals in early and mid-lactation. Mean arterial plasma concentrations for ${\beta}$-hydroxybutyrate and free glycerol were unchanged throughout the experimental periods in both groups. A-V differences and extraction ratio of ${\beta}$-hydroxybutyrate across the mammary gland did not alter during rbST administration. Mean arterial plasma concentrations for free fatty acids ($C_{16}$ to $C_{18}$), but not for triacylglycerol, increased in rbST-treated animals and were significantly higher than in control animals during early lactation (p<0.01). These findings suggest that an increase in MBF during rbST administration would not be a major determinant in the mediation of nutrient delivery and uptake by the mammary gland for increased milk production. Local changes in biosynthetic capacity within the mammary gland would be a factor in the utilization of substrates resulting in the rate of decline in milk yield with advancing lactation.

• 생물환경조절학회지
• /
• 제23권3호
• /
• pp.167-173
• /
• 2014

고온기 시설내에서 토마토를 재배할 때 최적의 측지관리방법을 구명하고자 본 실험을 수행하였다. 유니콘(몬산토 코리아, 한국)을 접수로, B-블로킹(다끼이종묘, 일본)을 대목으로 접목한 방울토마토 접목묘를 실험에 사용하였다. 배지는 코이어 자루배지를 사용하였고, 급액은 타이머 제어법으로 제어하였다. 측지를 전부 제거한 처리(ACUT), 화방 아래 측지의 잎을 2매 남기는 처리(PCUT) 및 모든 측지의 잎을 2매 남기는 처리(LEFT) 등 모두 3가지 방법으로 처리하였다. 연구결과, 토마토의 영양과잉으로 인한 이상경 발생시에는 측지를 유지하여 영양생장으로 많은 에너지가 사용되도록 하면 해결되는 것으로 나타났으며, 적절한 측지관리로 작물의 생장상도 재배자의 요구에 맞게 조절할 수 있을 것으로 사료되었다. 본엽과 측지의 잎들에 대한 광합성 속도는 차이가 없었으며, 처리에 따른 엽면적의 차이만 있었다. 따라서 처리간 엽면적의 차이에 의해 광합성 산물 총량의 차이가 발생하고, 이는 수확량에 영향을 주는 것을 확인하였다. 또한 고온기 토마토 재배에서 5단 이하의 단기밀식재배의 경우에는 측지를 모두 제거하는 것이 수확량과 수확속도에 효과적이었으나, 5단 이상의 장기재배에서는 모든 측지의 잎 2매를 남겨서 관리하는 것이 작물의 생육과 수확량에 효과적이었다.

• 생물환경조절학회지
• /
• 제23권4호
• /
• pp.309-313
• /
• 2014

본 실험은 저온기 토마토 재배시 토마토의 생육과 수확량에 최적의 측지관리방법을 구명하고자 수행하였다. 방울토마토인 유니콘(몬산토 코리아, 한국)을 실험에 사용하였다. 배지는 코이어 자루배지를 사용하였다. 모든 측지를 제거하고 모든 화방의 상부 잎 1매까지 제거한 처리(UP-FL), 측지를 전부 제거하고 착과한 화방의 상부 잎 1매까지 제거한 처리(UP-FR), 모든 측지를 제거한 처리(AS-All), 화방 하부 첫 번째 측지의 잎 2매를 유지하는 처리(AS-Part) 등 모두 4가지 방법으로 처리했다. 이상엽의 발생은 UP-FL, UP-FR, AS-All, AS-Part 순으로 많았다. 즉, 주지와 측지의 잎을 많이 제거한 처리일수록 이상엽의 발생이 많았다. 그리고 이상엽은 영양생장과 생식생장이 균형을 균형을 이루는 2~3화방 개화기 이후에는 해소되는 것으로 나타났다. 5화방까지의 수확량은 처리간 차이가 없었다. 따라서 저온기 토마토 재배시 생육초기에는 과도한 측지제거 및 적엽은 지양하는 것이 좋은 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제21권3호
• /
• pp.404-413
• /
• 2008

Major objectives were to evaluate effects of three schemes of bST-supplementation of Holstein cows (142.8 mg/14 d, POSILAC) during the prepartum and/or postpartum periods through 63 d (${\pm}3d$) of lactation. Measures evaluated the potential of treatments to improve body weight (BW) and body condition score (BCS), provoke changes in plasma concentrations of somatotropin (ST) and IGF-I, and improve milk yield, milk composition (percentages of protein and fat, and somatic cell counts), and several calving variables. Multiparous Holstein cows were randomly assigned to a $2{\times}2$ factorial arrangement of treatments (TRT) to give four groups (I = no bST, n = 26; II = bST postpartum, n = 25; III = bST prepartum, n = 27; IV = bST prepartum and postpartum, n = 25). During the prepartum period, cows in groups I and II were not supplemented but those in groups III and IV were supplemented every 2-wk beginning 21 d before expected calving date through calving. During the first 63 DIM only cows in groups II and IV were supplemented with bST. From 64 DIM through the end of lactation cows in all groups were supplemented with the full lactation dose of bST (500 mg/14 d). The BW and BCS were recorded weekly throughout the prepartum and postpartum periods and every 2-wk beyond 70 DIM. Blood samples were collected 3-times a week for analyses of ST and IGF-I. Milk yields were recorded daily though 150 DIM. Prepartum supplementation of bST did not affect BW or BCS, but mean concentrations of ST were increased 12.2% and were 15.5% greater at calving. Overall, mean concentration of IGF-I was not affected by treatment but concentrations were greater at 1 and 2 wk before calving in bST-supplemented cows. During the first 63 DIM the BW and BCS were not affected by treatment. Significant effects of bST-supplementation were detected on concentrations of ST, IGF-I and on milk yield compared to non-supplemented cows in group I. Postpartum concentrations of ST were greater in bST-supplemented cows (TRT II and IV; +41.9 and 54.6%). However, concentrations of IGF-I were greater only in cows in group IV (+25.9%) during the postpartum period. Overall, the three bST-supplemented groups had greater actual milk yield than the control group (I) during the first 63 and 150 DIM. The actual milk yields during 63 and 150 DIM were 6.5 and 4.6 kg/d greater for cows in group IV than cows in group I and the 305-d ME milk yield also was 15.6% greater. No adverse effects of TRT were observed on calf birth weight, colostrum immunoglobulins, ease of calving or other measures evaluated.

• 생명과학회지
• /
• 제21권4호
• /
• pp.584-588
• /
• 2011

본 연구에서는 유기농자재인 키토산, 목초액 및 EM 활성액 등을 공시재료로, 배추 정식 전에 100배액 토양관주 처리하고, 배추 정식 후 15일 간격으로 엽면살포 농도를 100배액과 1,000배액으로 3회 엽면살포한 후 배추의 생육 및 토양 미생물상의 변화에 대해 분석하였다. 유기농자재 처리에 따른 배추의 생육특성은 대조구에 비해 유기농자재 처리구에서 생육이 양호하게 나타났으며, 유기농자재 간에는 키토산 처리구에서 양호하였고, 특히 키토산 1,000배액 처리구에서 생육이 양호하였으며, 주중이 5.60 kg으로 가장 무거웠다. 유기농자재 처리에 따른 토양 미생물상 변화는 대조구에 비해 유기농자재 처리구에서 세균, 트리코데마 및 방선균수은 증가한 경향을 보였고, 사상균수는 약간 감소한 경향을 보였으나 처리간 일정한 경향은 없었다. 유기농처리구 간에는 키토산 1,000 배액 처리구에서 세균, 트리코데마 및 방선균수가 가장 많이 증가하였다.

• 한국잡초학회지
• /
• 제7권1호
• /
• pp.52-57
• /
• 1987

To know the effects of weeding periods (weeding from 12 days, 28 days and 42 days after seeding to harvest, and weeding from seeding to 14 days, 28 days and 42 days after seeding) and growing conditions such as transparent polyethylene film mulch (P.E. mulch) and bare soil on growth and yield of peanuts, "Yeongho-Tangkong" was planted on May 10, 1984. Under P.E. mulch, the number of weeds was higher, but the weed dry weight was lower than in bare soil by the middle of July. Sixty days after seedings, the length of main stems in weedy check plots was longer, but shoot dry weight was lower compared to weed free plot. In the correlation coefficients between weed dry weight and the shoot dry weight of peanut on July 14, the growth retardation of peanuts due to weeds was showed earlier under P.E. mulch than in bare soil. Shoot dry weight, shelling ratio, number of seeds per pod, 100 pod weight, and seed yield were higher under P.E, mulch compared to bare soil. But weed dry weight, length of branches, number of pod bearing branches, number of pods per square meters, and pod yield were similar between P.E. mulch and bare soil. Shoot dry weight of peanuts, length of branches, number of pod bearing branches, number of pods per square meters, pod yield, 100 pod weight, 100 seed weight, and seed yield in weed free plots from 28 days after seeding to harvest (28 DAS-Harvest) were higher compared to weed free plots from 42 DAS-Harvest. However, in the weed free plot from seeding to 42 days after seeding seed yield was lower than that of the continuous weeding plot due to lower number of pod bearing branches and number of pods per square meters. When weed was not controlled at the later growth stages of peanuts, reduction in seed yield due to weeds was greater in bare soil than that under P.E. mulch.