6,943 research outputs found
The effect of vitamin E in plasma and lipid peroxidation in newborn pigs
Three experiments were conducted to determine the effect of injected alpha-tocopherol on plasma iron and lipid peroxidation in the newborn pig and the optimum level of vitamin E and iron for practical application and optimum performance in the commercial swine industry.
In the first experiment 48 newborn cross-bred pigs were used in a 2*4 factorial arrangement with 8 pigs coming from each of 6 litters. The treatments consisted of 2 levels of iron: 0 or 100 mg as gleptoferrin at 3 days of age and four alpha-tocopherol levels: 0, 300, 600 and 900 lU.
The second (32 pigs) and third (48 pigs) experiments utilized 80 newborn cross-bred pigs in a 2*4 factorial arrangement with 4 pigs per treatment in experiment 2 and 6 pigs per treatment for experiment 3 . The treatments consisted of two levels of iron: 100 or 200 mg as gleptoferrin at 3 days of age and four alpha-tocopherol injections: 0, 300, 600 and 900 lU. Results obtained from experiment 1 indicated that iron injections of 100 mg significantly increased blood hematocrit and hemoglobin levels on wk1, wk2, and wk3 when compared to no iron injections. Alpha-tocopherol injected at 300, 600 and 900 lU significantly increased plasma α-tocopherol concentration on wk1, wk2, and wk3. There were more significant changes at an early age (wk1 and wk2) than wk3 on plasma α-tocopherol concentration. Iron injection of 100 mg significantly increased plasma iron concentration on wk1 and wk3 when compared to no iron injection. Pigs injected with 100 mg of iron had lower plasma lipid peroxidation levels on wk1, wk2, and wk3 when compared to uninjected pigs. This result suggests that iron injection of 100 mg did not cause a tremendous oxidative stress and damage to the newborn pig. Plasma iron was increased by an injection of 100 mg of iron at 3 days of age but lipid peroxidation levels were lower. Thus, the injection of 100 mg of iron must not provide a serious free radical challenge to the young newborn pig. Iron injections of 100 mg did not affect the weight gain at 21 days and weaning. Pigs treated with vitamin E 900 lU injections tended to be heavier than other levels of vitamin E treated baby pigs at day 21 and at weaning. Partial correlation coefficients (-.44) between 21 day\u27s weight and Vit.E on wk3 suggest that heavier baby pigs had lower Vit.E concentration in their plasma. wk1 tiobarbituric reactive substances (TEA) and wt of pig at day 21 and weaning wt had significant negative correlations. Vit.E injections were positively highly correlated with wk1 TEA values and wk2 Vit.E. wk1 TEA, wk2 TEA (.017), and wk3 TEA (.033) were highly positive correlated with each other. Plasma iron was not correlated with wk2 TEA (.69) , or wk3 TEA (.41) . These results suggest that iron injection of 100 mg did not result in a elevated plasma iron concentration that would cause free radical damage in the newborn pig.
The results obtained from experiments 2 and 3 indicated that there was a significant increase when higher injections of α-tocopherol were given to have higher plasma α-tocopherol concentrations during the experimental period. Lipid peroxidation levels were significantly decreased with vitamin E injections of 300, 600, and 900 lU on wk2 and wk3 when compared to no vitamin E injections. There was a tendency for Vit. E injections to decrease lipid peroxidation levels on wk1. Iron injections of 100 or 200 mg did not increased free radical stress. As observed in experiment 1, increasing the amount of iron injected from 0 to 100 mg did not result in increased lipid peroxidation. There was a trend for Vit.E injections to increase weights at 21 days and weaning. However, the birth weights of groups 600 and 900 lU Vit.E could have influenced the 21 day and weaning weight, since they were heavier at birth. Weight at birth, and day 21, and vitamin E were negatively highly correlated -0.37 and -0.34, with wk1 Vit.E, respectively. Partial correlation coefficients (-.35) between 21 day weight and Vit.E on wk3 indicated that heavier baby pigs had lower Vit.E concentration in the plasma. wk1, wk2 and wk3 TEA and wt of the pig at day 21 had high negative correlations -.36, -.40,and -.33, respectively. This indicated that larger pigs had lower TEA values at all 3 measurement times. Plasma iron was not significantly correlated with TEA at any measurement period. In addition, plasma vitamin E and TEA at all 3 measurement periods were not significantly correlated in these 2 experiments.
Increasing the amount of iron injected from 100 to 200 mg did not result in increased lipid peroxidation. Thus, the injection of 2 00 mg of iron must not provide a significant free radical challenge to the newborn pig. Eased on wk2 and wk3 TEA values, this suggests that a 300 lU injection of Vit.E could be a marginal recommendation volume without severe oxidative damage with 100 or 200 mg iron
Erratum to “Economic Analysis for Setting Appropriate Repair Cycles on the Fixed Materials and Facilities in the Public Rental Housing”
Currently, repair and maintenance cycles that follow the completion of construction facilities lead to the necessitation of subsequent data on the analysis of study and plan for maintenance. As such, an index of evaluation was drafted and a plan of maintenance cycle was computed using the investigation data derived from surveying target housing units in permanent rental environmental conditions, with a minimum age of 20 years, and their maintenance history. Optimal maintenance and replacement methods were proposed based on this data. Economic analysis was conducted through the Risk-Weighted Life Cycle Cost (RWLCC) method in order to determine the cost analysis of maintenance life cycle methods used for repair. Current maintenance cycle methods that have been used for 20 years were also compared with alternative maintenance cycles
Dynamic Contact Angle in Rim Instability of Dewetting Holes
The effects of dynamic contact angle (theta(d)), between a substrate and the melt of a dewetting polymer thin film, on the evolution of rim instabilities of dewetting holes were reported. Various theta(d)\u27s were achieved by covering SiOx surfaces with different coverage of octadecyltrichlorosilane. On each surface, the morphology of the dewetting holes was examined in detail as the hole grew to a certain size. Rim instabilities, in terms of undulations in both r and z directions, became more pronounced as theta(d) increased, under which condition, narrower and higher rims were also observed. Experimentally, atomic force microscopic scans of the rim were used to obtain the rim profile, which was predicted using theta(d). The predicted rim profile was used, in combination with the analysis of Rayleigh instability of a cylindrical fluid, to interpret the rim instability. The model captures the basic trend of the rim instability dependency on theta(d). The study demonstrates the importance of the substrate properties on the rim instability and the destabilization of polymer thin films during hole growth. (c) 2006 American Institute of Physics
Numerical analysis of NOx reduction for compact design in marine urea-SCR system
ABSTRACTIn order to design a compact urea selective catalytic reduction system, numerical simulation was conducted by computational fluid dynamics tool. A swirl type static mixer and a mixing chamber were considered as mixing units in the system. It had great influence on flow characteristics and urea decomposition into ammonia. The mixer caused flow recirculation and high level of turbulence intensity, and the chamber increased residence time of urea- water-solution injected. Because of those effects, reaction rates of urea decomposition were enhanced in the region. When those mixing units were combined, it showed the maximum because the recirculation zone was significantly developed. NH3 conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of NOx reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of NOx reduction efficiency
Nuclear magnetic resonance microscopy using strong field gradients and constant time imaging
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1996.Includes bibliographical references (leaves 79-80).by Sung-Min Choi.M.S
Optimalne potrebe juvenilnih morskih grgeča sebastes schlegeli u proteinima i lipidima
U ovom istraživanju su analizirane optimalne potrebe juvenilnih morskih grgeča Sebastes schlegeli u proteinima i lipidima. 810 juvenilnih riba je izabrano po principu slučajnosti i distribuirano u 27 tankova od po 50 L sa protočnih sistemom. Pripremljeno je 9 eksperimentalnih smeša u vidu 3x3 faktorijalne eksperimentalne postavke: tri nivoa proteina (45, 50 i 55%) x tri nivoa lipida (11, 15 i 19%). Nivo proteina je imao uticaj na prirast riba, dok nivo lipida nije. Prirast riba hranjenih smešom u odnosu 50P-15L (50% proteina i 15% lipida) je bio veći nego prirast riba hranjenih smešama sa 45% proteina, bez obzira na nivo lipida, ali je bio isti kao kod riba hranjenih sa smešama 50P-11L, 50P-19L, 55P-11L, 55P-15L i 55P-19L. Stopa efikasnosti hrane (FER) riba je bila pod uticajem proteina u hrani ali ne i nivoa lipida. Stopa efikasnosti proteina (PER) riba je takođe bila pod uticajem proteina u hrani ali ne i nivoa lipida. Može se zaključiti da je za juvenilne Sebastes schlegeli optimalan nivo proteina i lipida za dobar prirast i iskoristljivost hrane (PER and NRE) 50% i 15% odnosno 45% i 19%, dok je optimalan odnos proteina i energije 27.4 i 23.9 mg protein/kJ
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