稀饲料管道输送技术研究

生猪规模化养殖中人工加料劳动强度大,耗费劳动力多,此外还造成6%的饲料洒落浪费。随着我国生猪规模化养殖比重增大,饲料机械化输送成为必然发展趋势。稀饲料管道输送的研究开发可有效利用了农副产品废弃物及食品工业废液,实现资源的合理利用,降低饲料成本。可提高饲料转化率和日增重率,增大养猪场的经济效率。为解决随着稀饲料浓度增大出现的沉降和阻塞现象,延长管道输送距离,研究了制浆设备中饲料的搅拌混配及打浆,管道输送中的临界流速、摩阻损失以及加气减阻等问题。     

蔗糖载体调控作物“源、库”分配的研究进展

蔗糖是植物光合作用及物质转运的主要形式,植物体内重要的信号物质,并且为植物生长代谢提供碳源与能量。而在蔗糖转运过程中,蔗糖载体（SUT）发挥着不可替代的作用。首先介绍了植物中“源、库、流”理论和蔗糖载体基因分离,阐述了蔗糖载体在蔗糖由“源”到“库”转运过程中发挥的作用,及与农艺性状的关系,并阐明蔗糖在植物体生长发育过程中的作用。归纳总结了蔗糖载体介导的蔗糖跨膜转运过程,进而探讨了蔗糖跨膜转运存在的问题。     

A novel iron transporter in Streptococcus iniae

Streptococcus iniae is a major pathogen that results in considerable economic loss to fish farms. Restricted availability of iron is a huge obstacle to survival for pathogenic bacteria during infection, and iron acquisition is important in bacterial virulence. In this study, S. iniae HD‐1 was shown not to produce siderophores (low‐molecular‐weight compounds) but rather to require iron‐containing proteins for growth under iron‐restricted conditions. The adenosine triphosphate (ATP)‐binding‐cassette (ABC) transporter system (ftsABCD), which is cotranscribed by four downstream genes, namely, ftsA, ftsB, ftsC and ftsD, was identified as responsible for haem utilization of S. iniae. Analysis of the corresponding recombinant protein, FtsB, indicated that it is a putative lipoprotein which plays a role in haem utilization and is produced in vivo during infection with S. iniae HD‐1, and therefore may be a potential candidate antigen for a streptococcal vaccine.     

Physiological changes during simulated live transport of Cancer pagurus and recovery in holding tanks

The trade of live Cancer pagurus in Portugal is totally dependent on imports, mainly from UK. Animals are transported for 48–58 h in conditions that promote high mortalities (40–60%) due to cumulative stressors. The present work aimed to optimize transport, by comparing the physiological responses of edible crab during different simulated live shipment systems for 48 h and recovery conditions: (a) immersed crabs at 12°C; and (b) air‐exposed crabs at 4°C and subsequent recovery at 16°C with and without pre‐acclimation. Both simulated transport systems induced physiological stress, culminating in 25% mortality in immersed conditions and only 4% in air‐exposed conditions. Both systems elicited anaerobic responses marked by hyperglycaemia and increased l ‐lactate concentration in haemolymph. At the end of the recovery period only air‐exposed animals resumed to l ‐lactate and pH control values, the lowest mortality was achieved with crabs acclimated at the lowest temperature (from 6 to 16°C at 1.5°C/h). Overall, results showed that crabs can be transported in air‐exposed conditions at 4°C and acclimated from 6 to 16°C and reach similar physiological conditions than the traditional transport in immersed conditions at 12°C.     

喷淋式MOCVD反应器的传质分析及结构设计

对喷淋式MOCVD反应器中的传质过程进行了数理分析,并提出了该类型反应器的结构设计原则.数理分析显示,基片上方各点的轴向速度仅是垂直距离的函数,与径向距离无关;顶壁高度对反应室内的传质有重要影响.设计喷淋式反应器结构时,应重点考虑顶壁高度和反应室半径的选取、基片加热方式以及喷淋头结构的柔性设计.     

甘草次酸在Caco-2细胞模型中的转运机制

采用液相-质谱检测甘草次酸在HBSS磷酸盐缓冲液中的转运量,结果表明:甘草次酸的转运量受时间、浓度以及p-糖蛋白抑制剂维拉帕米和汉防己甲素的影响,表观渗透系数P(appBL-AP)为(17.1±4.2) ×10-6～(54.3±6.3) ×10-6cm·s-1、P(appAP-BL)为(15.6-±3.4) ×10-6...     

环氧二十碳三烯酸生物学作用机制的研究进展

花生四烯酸经过细胞色素P450 (cytochrome P450,CYP)表氧化酶途径生成环氧二十碳三烯酸(epoxyeicosatrienoic acids,EETs)。EETs可以通过调节离子通道和基因表达,从而发挥促进血管舒张、抗炎和细胞增殖等作用。EETs也可通过激活信号转导途径和调节基因表达或与细胞膜受体结合发挥多种生物学功能。EETs也可快速与细胞膜磷脂结合后以共吸收的方式被细胞摄取。文章主要从EETs的来源、去路、作用机制等方面进行讨论。     

Simulation of the impact of climate change on the egg and larval transport of Japanese anchovy (Engraulis japonicus) off Kyushu Island,the western coast of Japan

In order to investigate the impact of climate change on egg and larval transport of Japanese anchovy (Engraulis japonicus) off Kyushu Island western Japan, we conducted particle‐tracking simulations on transport success/failure to fishing grounds from 1960 to 2007. The modeled transport success since the mid‐1990s increased and decreased in the offshore and coastal zones, respectively, compared with the 1960s and 1970s. The estimated northward shift of the spawning ground and weakened Tsushima Warm Current contributed to increase in modeled transport success to the offshore zone. Conversely, the weakening trend of the modeled onshore current in the Goto‐Nada Sea combined with the northward shift of the spawning ground resulted in unsuccessful larval transport. These results suggest that fluctuations in juvenile and subadult anchovy catches in this area may be attributable to changes in the physical environment. The present study showed that changes in transport success induced by oceanographic fluctuations related to climate change, have the potential to affect anchovy recruitment off the western coast of Japan.     

花后干旱条件下冬小麦顺序和非顺序衰老同化物积累及转运特性

以小麦顺序衰老(正置茎)和非顺序衰老(倒置茎)茎为材料,比较研究了自然天气和干旱条件下小麦正置茎和倒置茎叶片绿叶面积、光合速率、蔗糖磷酸转运酶活性以及地上器官同化物积累和转运特性,旨为进一步研究小麦叶片非顺序衰老的生理生化机制提供思路和理论指导。试验表明:无论是自然天气条件还是干旱条件,温麦19、豫麦19和兰考矮早8倒置茎倒二叶的绿叶面积、光合速率和叶片干重均明显高于旗叶,表现出旗叶早于倒二叶衰老的特征;倒置茎花后同化物转运量、转运率和对籽粒的贡献率、穗重以及叶片蔗糖磷酸合成酶活性均明显高于正置茎。表明小麦叶片的非顺序衰老与花后同化物的快速转运有关,这种衰老方式对小麦籽粒的后期充实是有利的,并且对干旱条件有较强的适应能力。