A triple-layered PMMA/Ni64Zr36/PDMS hydrogen gas sensor using hydrogen permeable alloy and flexible polymer layers is fabricated through spin coating and DC-magnetron sputtering. PDMS(polydimethylsiloxane) is used as a flexible substrate and PMMA(polymethylmethacrylate) thin film is deposited onto the Ni64Zr36 alloy layer to give a high hydrogenselectivity to the sensor. The measured hydrogen sensing ability and response time of the fabricated sensor at high hydrogen concentration of 99.9 % show a 20 % change in electrical resistance, which is superior to conventional Pd-based hydrogen sensors, which are difficult to use in high hydrogen concentration environments. At a hydrogen concentration of 5 %, the resistance of electricity is about 1.4 %, which is an electrical resistance similar to that of the Pd77Ag23 sensor. Despite using low cost Ni64Zr36 alloy as the main sensing element, performance similar to that of existing Pd sensors is obtained in a highly concentrated hydrogen atmosphere. By improving the sensitivity of the hydrogen detection through optimization including of the thickness of each layer and the composition of Ni-Zr alloy thin film, the proposed Ni-Zr-based hydrogen sensor can replace Pd-based hydrogen sensors.

Among the fuel cell electrolyte candidates in the intermediate temperature range, glass materials show stable physical properties and are also expected to have higher ion conductivity than crystalline materials. In particular, phosphate glass has a high mobility of protons since such a structure maintains a hydrogen bond network that leads to high proton conductivity. Recently, defects like volatilization of phosphorus and destruction of the bonding structure have remarkably improved with introduction of cations, such as Zr4+ and Nb5+, into phosphate. In particular, niobium has proton conductivity on the surface because of higher surface acidity. It can also retain phosphorus content during heat treatment and improve chemical stability by bonding with phosphorus. In this study, we fabricate niobium phosphate glass thin films through sol-gel processing, and we report the chemical stability and electrical properties. The existence of the hydroxyl group in the phosphate is confirmed and found to be preserved at the intermediate temperature region of 150-450 oC.

본 연구는 추청벼를 이용하여 총체 벼 사일리지를 조제 하였을 때 총체 벼 사일리지의 사료가치 및 부위별 소화율 을 조사하여 총체 벼의 이용성을 검정하기 위하여 수행되 었다. 총체 벼 사일리지의 무기물 함량은 망간이 가장 높 았으며 탄소, 철, 아연, 구리 등 순으로 나타났다. 그리고 마그네슘 함량이 가장 낮게 나타났다. 추청벼 총체 사일리 지의 아미노산은 glutamic acid 함량이 가장 높았으며 leucine, asparagine, alanine, valine, arginine 순으로 나타났 다. 그리고 methionine 함량이 가장 낮았다. 추청벼 총체 사일리지 부위(총체 벼, 낟알을 제거한 줄기, 왕겨를 포함 한 낟알, 쌀)에 따른 시간별 반추위내 건물 소화율은 쌀이 가장 높았으며 왕겨를 포함한 낟알, 총체 벼, 낟알을 제거 한 줄기 등 순으로 나타났다. 따라서 본 연구에서는 추청 벼 총체 사일리지 소화율은 부위에 따라 약간의 차이를 보 였으며 무기물 중 망간 그리고 아미노산 중 glutamic acid 가 가장 높은 함량을 보였다.

This study was conducted to investigate the effects of the slaughtering age on carcass characteristics and economic efficiency of Holstein steers. The Holstein steers (n=27, 4 months old, average body weight 160 ㎏) were divided into 3 groups and raised with TMR feeding formulation until 18, 20 and 22 months old, respectively. In the result, final body weights were 703, 768 and 804 ㎏, and average daily gains were 1.32, 1.32 and 1.27 ㎏, respectively. Dry matter intakes (DMI) were 8.62, 8.94 and 9.24 ㎏. Feed conversion ratio was 6.53, 6.77 and 7.28 for 18, 20 and 22 months old groups. Feed conversion ratio was increased as the fattening periods increased. In yield traits, carcass weight was significantly lower in 18 months old group compared to other groups (p<0.05). The back fat thickness were 8.4, 7.3 and 7.8 ㎜, rib eye area were 70.6, 73.4 and 73.84 ㎠, and the meat yield index was 62.9, 62.5 and 62.1 when slaughtered at 18, 20 and 22 months old, respectively. In the frequency of the yield grade (A:B:C, %), grade B was highest at 20 months old group as 0:75:25. In the quality traits, marbling score, texture and maturity were not different among slaughtering age groups. However, marbling score tended to be increased at 22 months old group. Meat color and fat color were higher at 22 months old group compare to other groups (p<0.05). In the frequency of the quality grade (1+:1:2:3,%), 22 months-old group was the greatest as 12:0:50:38. The income was highest for 20 months old group as 279 thousand wons among the 3 groups. Therefore, the slaughtering ages of Holstein steers may be appropriate at 20 months old.

The use of high throughput screening (HTS) in drug development is principally for the selection new drug candidates or screening of chemical toxicants. This system minimizes the experimental environment and allows for the screening of candidates at the same time. Umbilical cord-derived stem cells have some of the characteristics of fetal stem cell and have several advantages such as the ease with which they can be obtained and lack of ethical issues. To establish a HTS system, optimized conditions that mimic typical cell culture conditions in a minimal space such as 96 well plates are needed for stem cell growth. We have thus established a novel HTS system using human umbilical cord derived-mesenchymal stem cells (hUC-MSCs). To determine the optimal cell number, hUC-MSCs were serially diluted and seeded at 750, 500, 200 and 100 cells per well on 96 well plates. The maintenance efficiencies of these dilutions were compared for 3, 7, 9, and 14 days. The fetal bovine serum (FBS) concentration (20, 10, 5 and 1%) and the cell numbers (750, 500 and 200 cells/well) were compared for 3, 5 and 7 days. In addition, we evaluated the optimal conditions for cell cycle block. These four independent optimization experiments were conducted using an MTT assay. In the results, the optimal conditions for a HTS system using hUC-MSCs were determined to be 300 cell/well cultured for 8 days with 1 or 5% FBS. In addition, we demonstrated that the optimal conditions for a cell cycle block in this culture system are 48 hours in the absence of FBS. In addition, we candidates using our HTS system which demonstrates the feasibility if using hUC-MSCs for this type of screen. Moreover, the four candidate compounds can be tested for stem cell research application.

This study was conducted to evaluate effects of chopped and non-chopped rice straw on characteristics of silage-basedtotal mixed ration (TMR) according to the particle size, laceration, and in situ dry matter (DM) degradation. The threerice straw silages as low moisture unchopped (LMUC; 32.75% of moisture, unchopped), high moisture unchopped(HMUC; 42.05% of moisture, unchopped), and high moisture chopped (HMC; 44.71% of moisture, chopped to 30cmlengths) were tested. Samples were collected at every 5 minutes from 10 min of pre-mixing to 50 min. The percentageof >19mm in LMUC and HMC was decreased to 7.23% and 7.74% (p<0.05), respectively, and the percentage of 8mm>was increased to 5.81% and 5.24%, respectively. Furthermore, the laceration of forage by a TMR mixer showed that therewas little change in the reduction of 1.26% in HMC, but was reduced to 7.53% and 16.06% in LMUC and HMUC,respectively. The peNDF>8 was maintained 17~18.5% of the optimal requirement level for 15 to 45 min mixing in LMUCand for 30 to 50 min mixing in HMC, but it exceeded the level of peNDF>8 in the range of 21.49 to 22.53% for 50minmixing in HMUC. However, ruminal in situ DM degradation appeared as LMUC>HMUC>HMC. Therefore, theseresults suggest that the rice straw silage may be useful for high-yielding lactating cows, if it can be supplied with theadequate peNDF, and the limiting factor on DMI and DM degradation was reduced by crushing of the plant tissue, althoughthe rice straw silage was concerned to low quality forage.

This study was carried out to investigate the effect of DDGS hydrolysate (H-DDGS) and rumen-protected lysine-choline complex (RPLC) on milk production and blood metabolites in dairy cows. Feeding trials was performed to latin-square design using the 4 mid-lactational cows for 8 weeks, and treated with T1 (H-DDGS 1.1 kg), T2 (H-DDGS 0.73 kg + RPLC 0.15 kg), T3 (H-DDGS 0.37 kg + RPLC 0.30 kg) and T4 (H-DDGS 0.37 kg + RPLC 0.15 kg) according to the content of protein source. Dry matter intake (DMI) of TMR and average weight showed no significant difference between treatments. The milk production of T1, T2 and T4 were significantly higher than T3 treatment (p < 0.05), and milk/DMI efficiency tend to increase in the T1. Milk components showed no significant difference between treatments, however, the milk protein of T2 increased to 0.15% than T1. Also blood metabolites showed no significant difference between treatments. But T-CHO level numerically represented a lower trend in the treatments of adding to RPLC compared with T1. This result suggests that the high level (1.1 kg) of H-DDGS is expected to improve the feed utilization without the negative impact on weight gain, feed intake and milk production as the lactation stage of dairy cows proceeds, and 0.15 kg of RPLC under the same feeding conditions of H-DDGS may be useful on fat metabolism.

The major free sugars of buckwheat plants were fructose, glucose, and maltose but their contents and compositions were influenced by the different wavelength of light. Free sugar contents of Clfa 39 (Fagopyrum tataricum) were higher than those of Yangjul-maemil (Fagopyrum esculentum) regardless of the light sources. As treated with red and blue light, the free sugar contents in the leaves of buckwheat plants were slightly increased, but their contents in the stems and flowers were lower than those of natural light condition. Under the natural light condition, maltose was detected in every tissues of buckwheat plants, but as treated with blue and red light, it was not detected in the flowers of buckwheat plants. Citric, malic and acetic acid were detected as major organic acids in buckwheat plants. Red and blue lights decreased the total organic acid contents in buckwheat plants as compared with natural light condition. It was considered that blue light are less active than red light for the accumulation of organic acids. Tataric acid was detected only in the leaves of buckwheat plants, however, as treated with red and blue light, it was not detected in the leaves of Clfa 39. Flowers of Yangjul-maemil contained a considerable amount of rutin and quercitrin. Only small amount of quercitrin was detected in leaves, but it was not detected in stems. On the other hand, Clfa 39 leaves contained a considerable amount of rutin, quercetin and small amount of quercitrin, but quercitrin and quercetin were detected only in the stems of Clfa 39. Red and blue lights significantly decreased the contents of rutin, quercitrin, and quercetin in buckwheat plants as comparing with natural light condition. Rutin content in the flowers of Clfa 39 was increased under the red and blue light conditions.