Monooxygenase system of <Emphasis Type="Italic">Bacillus megaterium</Emphasis> ALA2: Studies on palmitic acid oxidation products

We identified many novel oxygenated FA produced from linoleic acid by microbial strain ALA2: 12,13,17-trihydroxy-9(Z)-octadecenoic acid (12,13,17-THOA); 12,13,16-trihydroxy-9(Z)-octadecenoic acid (12,13,16-THOA); 12-hydroxy-13,16-epoxy-9(Z)-octadecenoic acid; and 12,17;13,17-diepoxy-16-hydroxy-9(Z)-octadecenoic acid. 12,13,17-THOA, the main product, inhibits the growth of some plant pathogenic fungi. Recently, we reclassified strain ALA2 as Bacillus megaterium ALA2 NRRL B-21660 and opened a possible link with the well-studied catalytically self-sufficient P450 monooxygenase of Bacillus megaterium ATCC 14581 (NRRL B-3712) and B. subtilis strain 168 (NRRL B-4219). Now we have found that strain ALA2 also oxidizes palmitic acid into three oxygenated products: 13-, 14-, and 15-hydroxy palmitic acids. This indicates that strain ALA2 also possesses a monooxygenase system similar to the abovementioned well-known strains. These data facilitate studies on the oxygenase system of strain ALA2.     

ALA联合HPD光动力学治疗对S180腹水瘤细胞的影响的研究

目的 :通过细胞学水平研究确定ALA配合小剂量HPD激光光动力疗法促使肿细胞死亡及凋亡的光敏药用药剂量及与二者单独使用的差别方法 :以不同剂量的ALA(40 μg/ml、80 μg/ml、16 0 μg/ml)、HPD(2 .5 μg/ml、5 μg/ml、10 μg/ml)、二者联合与S180腹水瘤细胞一起培养 ,随后以 6 30nm半导体激光 2 0 0mW /cm2 ,照射肿瘤细胞 ,照射 2 0分钟 ,及与不用光敏剂单照激光、单用光敏剂不照光、不用光敏剂不照激光空白对照组比较。以流式细胞仪及倒置微镜观察促使肿瘤细胞凋亡或死亡的差别 ,寻找促使肿瘤细胞凋亡或死亡的最小合适剂量。结果 :ALA4 0 μg/ml配合HPD2 .5 μg/ml与S180腹水瘤细胞同时培养 ,6 30半导体激光 2 0 0mW /cm2 ,照射 2 0分钟组从形态学观察及流式细胞仪测定是能达到较佳的细胞凋亡的最小用光敏剂剂量。单纯ALA -PDT组中能达到小鼠S180腹水瘤细胞明显凋亡的最小剂量是ALA(80 μg/ml) ,单纯HPD -PDT组中能达到小鼠S180腹水瘤细胞明显凋亡最小剂量是HPD(5 μg/ml)。结论 :ALA4 0mg/kg配合HPD2 .5mg/kg ,6 30半导体激光2 0 0mW /cm2 ,照射 2 0分钟是能达到小鼠S180腹水瘤细胞明显凋亡的最小光敏剂剂量。     

“平面圆图”在电机仿真中的应用

提出了用“平面圆图”输出电机动态性能数值仿真波形的新方法.该方法在极坐标上以动画方式输出仿真结果,较之传统的xy平面直角坐标系,其突出优点是能够显示更大时域范围的仿真信息.文中结合ALA转子电机仿真实例对这种方法加以说明.     

Bioconversion of n−3 and n−6 PUFA by <Emphasis Type="Italic">Clavibacter</Emphasis> sp. ALA2

Clavibacter sp. ALA2 oxidized n−3 and n−6 PUFA into a variety of oxylipins. Structures of products converted from EPA and DHA were determined as 15,18-dihydroxy-14,17-epoxy-5(Z),8(Z),11(Z)-eicosatrienoic acid and 17,20-dihydroxy-16,19-epoxy-4(Z),7(Z),10(Z),13(Z)-docosatetraenoic acid by GC-MS and NMR analyses. In contrast, γ-linolenic acid and arachidonic acid were converted to diepoxy bicyclic FA, tetrahydrofuranyl monohydroxy FA, and trihydroxy FA. Thus, the structures of bioconversion products were different between n−3 and n−6 PUFA. Furthermore, strain ALA2 placed hydroxy groups and cyclic structures at the same position from the ω-terminal despite the number of carbons in the chain and the double bonds in the PUFA.     

轴向迭片各向异性转子电机振荡及异步运行分析

轴向迭片各向异性ALA转子电机是 90年代以来得到较快发展的 1种新型磁阻同步电机。在实验研究中 ,发现二极实验电机有振荡及异步运行现象。对此进行了深入的理论分析与探讨 ,揭示出电机转子铁芯 q轴导磁叠片中产生的“单轴转矩”是造成这种现象的根本原因 ,并在简化分析基础上推导出了单轴转矩计算的显式公式。结合实验电机给出了算例 ,最后提出了改进电机结构的措施     

变频器驱动下ALA转子电机运行性能的实验研究

论述了ALA转子电机在VVVF变频器供电起动下发生振荡的原因,指出电机发生振荡是由于电机的电磁阻尼系数较小。借助步进电动机消除低频振荡的方法,通过在转子上加装机械惯性阻尼器,提高了系统的抗干扰能力,使电机的变频起动性能有了明显的改善。同时,负载性能实验也证明惯性阻尼器能够显著提高电机的负载能力。     

Transforming salmonid aquaculture from a consumer to a producer of long chain omega-3 fatty acids

Recommendations to endorse the sustainability of wild fish stock utilisation, supporting the health of marine ecosystems, are clashing with those to increase omega-3 fatty acids (n−3 LC-PUFA) consumption and promoting human health.     

Production of 5-aminolevulinic acid by Propionibacterium acidipropionici TISTR442

Propionibacterium acidipropionici TISTR442 produced the highest amount of 5-aminolevulinic acid (ALA) when cultivated in medium supplemented with glycine at 18g/l. ALA production correlated with ALA synthase activity, whereas ALA dehydratase activity was maintained at a low level. ALA yield reached 405mg/l after prolonged cultivation for 1 month.     

口服ALA在皮肤及肿瘤中的代谢

目的 :探求ALA口服在皮肤及皮肤肿瘤中的代谢 ,寻求皮肤肿瘤光敏诊断最佳的ALA口服剂量及时间。方法 :口服不同剂量的ALA(2 0mg/kg、4 0mg/kg、6 0mg/kg、80mg/kg、10 0mg/kg) ,不同时间 (1小时、2小时、4小时、6小时、8小时、10小时、12小时、2 4小时、4 8小时 )以激光诱导荧光OMA检测系统测定肿瘤及左股部皮肤荧光 ,并经数据处理 ,寻求皮肤肿瘤与正常皮肤荧光相对值相差最大的合适的ALA口服剂量及诊断时间。结果 :脉宽 2 0或 30A皮肤肿瘤荧光值总和与组织荧光值总和之比除以正常皮肤荧光值与组织荧光值总和之比在口服ALA6 0mg/kg ,服ALA后 6 - 8小时时比值最大。结论 :从以上数据分析口服ALA作皮肤肿瘤OMA荧光光谱分析剂量以 6 0mg/kg ,服ALA后 6 - 8小时作荧光光谱分析较合适 ,计算相对值在峰值宽度 2 0 - 30A面积均可。