Enhancing operational stability and exhibition of enzyme activity by removing water in the immobilized lipase‐catalyzed production of erythorbyl laurate

Erythorbyl laurate was continuously synthesized by esterification in a packed‐bed enzyme reactor with immobilized lipase from Candida antarctica. Response surface methodology based on a five‐level three‐factor central composite design was adopted to optimize conditions for the enzymatic esterification. The reaction variables, such as reaction temperature (10–70°C), substrate molar ratio ([lauric acid]/[erythorbic acid], 5–15), and residence time (8–40 min) were evaluated and their optimum conditions were found to be 56.2°C, 14.3, and 24.2 min, respectively. Under the optimum conditions, the molar conversion yield was 83.4%, which was not significantly different (P < 0.05) from the value predicted (84.4%). Especially, continuous water removal by adsorption on an ion‐exchange resin in a packed‐bed enzyme reactor improved operational stability, resulting in prolongation of half‐life (2.02 times longer compared to the control without water‐removal system). Furthermore, in the case of batch‐type reactor, it exhibited significant increase in initial velocity of molar conversion from 1.58% to 2.04%/min. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:882–889, 2013     

Digestibility and energy value of cereal-based diets in relation to digesta viscosity and retention time in turkeys and chickens at different ages estimated with different markers

Digesta viscosity, ileal transit time of digesta, apparent ileal protein digestibility and apparent metabolisable energy (AME_N) of diets based on wheat and dehulled barley (WB), oats (O) or a mixture of these (WBO) fed as such or with enzyme supplementation in three- and six-week old turkeys and broilers were investigated. In addition, differences between ileal digestibility and AME_N calculated by using titanium dioxide (TiO₂), chromic oxide (Cr₂O₃) or acid insoluble ash (AIA) as indigestible markers were compared. Digesta viscosities were generally moderate reaching from 2.5 mPa · s to 7.3 mPa · s. The highest viscosities were observed in WBO diets. Viscosities were reduced with age in broilers, and were generally higher in turkeys than in broilers, especially at six weeks of age. Digesta retention time in ileum was elongated with age of the birds, pronouncedly in broilers. Oat inclusion to the diets decreased retention time especially in broilers at six weeks of age. Apparent ileal digestibility of protein ranged from 0.64–0.83, was lower at six weeks of age than at three weeks of age and generally lowest in O diets, especially in turkeys. AME_N of the diets ranged from 11.2–13.4 MJ/kg being higher at six weeks of age than at three weeks of age. AME_N of Diets O was the lowest but AME_N of WBO diets was higher than that of WB diets indicating a synergistic interaction of cereals, this trend being more pronounced in broilers. Enzyme supplementation decreased viscosity and improved AME_N in most diets, but did not affect ileal protein digestibility. Differences between ileal digestibility estimates obtained with TiO₂ or Cr₂O₃ were small and mainly not significantly different from 0. AME_N estimates were generally higher when calculated with Cr₂O₃ than with TiO₂. AIA gave remarkably lower AME_N values than TiO₂ (the significant differences ranging from 0.24–0.94 MJ/kg). In addition, effects of markers on AME_N estimates interacted with age of the birds and dietary treatments.     

Variation of in situ rumen degradation of crude protein and amino acids and in vitro digestibility of undegraded feed protein in rapeseed meals

In this study, 10 samples of rapeseed meal (RSM) from 10 different oil plants in Germany were examined. In situ rumen degradation of CP was determined by incubation over 1, 2, 4, 8, 16, 32 and 72 h in duplicate per time point using three rumen fistulated dry cows. Degradation kinetics were estimated by an exponential model and effective CP degradation was calculated. Degradation was corrected for small particle loss as the difference between washing loss and water-soluble fraction. Amino acid analysis was carried out in the samples and in the residues after 8 and 16 h of incubation in situ and degradation of individual amino acids was calculated for these incubation times. In vitro pepsin–pancreatin digestibility of CP (IPD) was determined in the samples as well as in the 8 and 16 h residues. Effective CP degradation for a rumen outflow rate of 8%/h (ED8) averaged 54.3% with a considerable variation among samples ranging from 44.3% to 62.7%. A multiple regression equation containing acid detergent insoluble N, total glucosinolates and petroleum ether extract as independent variables predicted ED8 with satisfying accuracy (R² = 0.74; RSD = 6.4%). Degradation of amino acids was different from that of CP for most amino acids studied, especially after 8 h of incubation. Compared with CP, degradation of essential amino acids was predominantly lower while degradation of non-essential amino acids was higher in most cases. However, for lysine and methionine no distinct difference with CP degradation was found. Degradation of individual amino acids was predicted from CP degradation with high accuracy using linear regression equations. Average IPD of RSM was 79.8 ± 2.6%. IPD was lower in the incubation residues and decreased with longer incubation time and increasing rumen degradation, respectively.     

An Evaluation Model of Supply Chain Performances Using 5DBSC and LMBP Neural Network Algorithm

A high efficient Supply Chain (SC) would bring great benefits to an enterprise such as integrated resources, reduced logistics costs, improved logistics efficiency and high quality of overall level of services. So it is important to research various methods, performance indicator systems and technology for evaluating, monitoring, predicting and optimizing the performance of a SC. In this paper, the existing performance indicator systems and methods are discussed and evaluated. Various nature-inspired algorithms are reviewed and their applications for SC Performance Evaluation (PE) are discussed. Then, a model is proposed and developed using 5 Dimensional Balanced Scorecard (5DBSC) and LMBP (Levenberg-Marquardt Back Propagation) neural network for SC PE. A program is written using Matlab tool box to implement the model based on the practical values of the 14 indicators of 5DBSC of a given previous period. This model can be used to evaluate, predict and optimize the performance of a SC. The analysis results of a case study of a company show that the proposed model is valid, reliable and effective. The convergence speed is faster than that in the previous work.     

Trends and inequities in colorectal cancer screening participation in Ontario,Canada, 2005–2011

Background: Participation in screening tests for colorectal cancer (CRC) is generally low in Ontario, Canada. In addition, inequities in participation exist including lower participation among low-income individuals, males and individuals living in rural areas. In April 2008, Colon Cancer Check (CCC) program, the province-wide CRC screening program, was launched in Ontario. This study describes the trends and inequities in CRC screening participation three years before and three years after the CCC, and assesses the effect of the program on CRC screening participation, overall and among certain population groups. Methods: We used administrative data to identify cohorts of individuals eligible for CRC screening in fiscal years 2005–2011. We calculated the age-standardized percent of Fecal Occult Blood Test (FOBT) participation, large bowel endoscopy participation, and being ‘up-to-date’ with CRC screening tests. Results: From 2005 to 2011, FOBT participation increased from 7.6% to 14.8%, large bowel endoscopy participation from 3.4% to 5.7%, and ‘up-to-date’ with CRC screening from 27.2% to 41.3%. Before the launch of the CCC program, the quarterly increase in FOBT participation was 0.07% (p = 0.19), increased immediately after the launch (1.8%, p < 0.01), followed by a decline (?0.08%, p = 0.08), returning to its pre-program increase rate. We noted a significant decrease in FOBT participation every summer (?0.44%, p < 0.01). The CCC program had minimal effect on large bowel endoscopy participation. Before the launch of the CCC program, the quarterly increase in ‘up-to-date’ with CRC screening was 0.9% (p < 0.01), increased immediately after the launch (2.5%, p = 0.05), followed by a modest decline thereafter (?0.59%, p < 0.02). From 2005 to 2011, recent residents living in low-income neighborhoods were consistently and significantly less likely to have a FOBT and be ‘up-to-date’ with CRC screening than long-term residents living in high-income neighborhoods (2.9–4.5%; 14.7–17.3% respectively). Pre-CCC inequities in CRC participation persisted after the launch of the program. Conclusion: CRC testing was increasing in Ontario from 2005. An immediate increase in CRC testing, FOBT in particular, occurred after the launch of the CCC program, followed by a return to its pre-CCC increase rate thereafter. Future efforts are needed to improve screening participation and address inequities.     

平榛种质资源坚果农艺性状鉴定与评价研究

平榛是我国重要的榛属植物资源,为鉴定、评价和保护平榛种质资源,提高其利用效率,采用主成分分析和聚类分析方法对99份平榛种质资源坚果的主要农艺性状进行了鉴定和综合评价。结果表明:平榛种质资源坚果的24个性状具有丰富的遗传多样性;10个数量性状的主成分分析确定了4类影响因子,反映了育种选择方向及潜力;基于各种质间形态性状的遗传差异,将99份平榛种质划分为5大类群,第Ⅰ类群可作为选育果面光滑品种的育种和候选亲本材料,第Ⅱ类群可作为选育大粒型、适宜机械化加工的育种和候选亲本材料,第Ⅲ类群具有作为市场产品的潜力,第Ⅳ类群可作为选育圆形、果面无条纹的育种和候选亲本材料,第Ⅴ类群可作为选育高丰产性品种的育种和候选亲本材料。上述研究为平榛种质资源的评价、保护和选优工作提供了基础数据。     

液体植物保护膜防治瓜实蝇的效果评价

【背景】瓜实蝇是一种重要的世界性检疫害虫,广泛分布在我国的热带、亚热带地区。在室内和田间测定了液体植物保护膜对瓜实蝇的控制效能,并初步探索了该保护膜的作用方式,以期为瓜实蝇的绿色防控提供一定的技术支撑。【方法】测定了应用保护膜后瓜实蝇的产卵、存活以及对苦瓜的为害率。【结果】保护膜显著影响了瓜实蝇产卵、存活以及选择性。随着保护膜浓度的升高,瓜实蝇的存活率和在供试苦瓜段上的产卵量逐渐下降,但300和400倍保护膜之间的差异不显著。当浓度达到400倍时产卵量最低,为0.33粒,死亡率最高,约为50%;室内研究发现保护膜可持续影响瓜实蝇产卵5 d;此外,通过将保护膜应用在损伤的苦瓜上,发现保护膜并没有抑制瓜实蝇产卵。在田间,研究发现苦瓜的果长影响了保护膜的应用效能,2种果长的苦瓜应用保护膜后12~14 cm苦瓜的被害率显著低于6~8 cm苦瓜的被害率。【结论与意义】400倍的植物液体保护膜是防治瓜实蝇的最佳浓度,应用时间建议每4 d一次。保护膜最合适的应用时期为果长发育至12~14 cm时,即生长后期。施用保护膜时一定均匀,且在寄主果实受到损伤时不宜喷施保护膜。