河蟹蚤状幼体对蛋白质、脂肪、复合矿物盐及维生素的适宜需求量研究

采用四因子三水平的正交实验法,研究了河蟹蚤状幼体至大眼幼体阶段对饲料中蛋白质、脂肪、矿物盐及复合维生素的适宜需求量.结果表明,影响河蟹其成活率的因素主次顺序为蛋白质>维生素>矿物盐>脂肪,其最优水平分别为蛋白质55.28 %;维生素2 %;矿物盐6 %;脂肪17.39 %.     

黄山栾果与栾果中维生素含量的研究

用高效液相色谱法测定了黄山栾果与栾果中的维生素A，D，E含量，结果表明：黄山栾果中维生素A的含量为22．29～70．28IU/g，维生素D2为0．223～2．117IU／g，维生素E为0．254-3．059mg／100g；栾果中维生素A的含量为43．95—91．71IU／g，维生素D2为0．035—2．707IU／g，维生素E为0．165-7．002mg/100g．综合其营养价值，黄山栾果和栾果在产品开发和利用上有较广阔的前景．     

Vitamin B12 amplifies circadian phase shifts induced by a light pulse in rats

Vitamin B₁₂ (VB₁₂) is a putative modulator of the human circadian clock, improving entrainability to the 24 h light-dark cycle. The present study was intended to elucidate the mechanism of VB₁₂ action in an animal model. In male rats free-running under constant dim illumination, a single light pulse of 50–1000 lux for 20 min given at circadian time (CT) 20 induced a 0.28 to 1.08 h phase advance and at CT 14 induced a 0.54 to 2.10 h phase delay. A 3 h intracerebroventricular (icv) infusion of 30 nmol VB₁₂ starting 2 h prior to a 20 min 200 lux light pulse significantly amplified phase shifts in comparison with saline-treated or untreated controls. The mean phase advance (1.13 h) was 1.8-fold greater than that of saline-infused controls, whereas the mean phase delay (2.28 h) was 2.9-fold greater. These values were comparable to the maximal phase shifts caused by 1000 lux light pulses in untreated rats. Since the same VB₁₂ treatment alone had failed to induce a phase shift in a previous experiment, these results indicate that VB₁₂ strongly enhanced light pulse-induced phase shifts and thus augmented the entrainability of the circadian clock to light.     

反相离子对高效液相色谱法同时测定药物中维生素B_1,B_2,B_6,B_(12)和PP

采用反相离子对高效液相色谱法同时测定药物中的维生素B_1,B_2,B_6,B_(12),和PP;叶酸在相同条件下也能分离完全。所用的分离柱为μBondapak C_(18);流动相为乙腈,0.01 mol/L磷酸二氢钾和三乙胺(14∶85.5∶0.5(体积比)),内含5 mmol/L十二烷基磺酸钠离子对试剂(简称PIC B_(12))和1.5％氯化钾并以磷酸调pH至2.78～2.82;组分以UV 254 nm检测。回收率为91％～104％,变异系数为1.0％～4.6％。     

维生素C的测定方法

目前研究维生素C测定方法的报道较多，文章对近年来有关维生素C的测定方法如光度分析法、荧光法、化学发光法、电化学分析法及色谱法等进行了综述，各种方法对实际样品的测定均有满意的效果。     

吡啶羧酸铬、VE对樱桃谷鸭肉鸭生产性能及胴体品质的影响

试验选择1日龄樱桃谷肉鸭600只,公母各半,随机分为3组,每组200只,每组分性别设组内重复4个,每个重复25只,分栏饲养二阶段(0～3周、4～7周)49天.各试验组在基础饲粮相同的条件下,以吡啶羧酸铬与VE为试验因子,分别添加0、400μgCr/kg、400μgCr/kg 100mgVE/kg,研究吡啶羧酸铬、VE对樱桃谷肉鸭生产性能与胴体品质的影响.试验结果表明:吡啶羧酸铬与VE具有提高肉鸭日增重、降低料肉比、显著降低皮脂率、提高胸肌、腿肌率、改善胴体品质、增加肉质嫩度、延长胸肉货柜贮藏期的作用.     

维生素K3的电化学研究

采用单扫示波极谱法，ＶＫ３在０．１ｍｏｌ／ＬＮａＣｌ底液中，于－０．４６Ｖ（ＳＣＥ）处有一良好的二阶导数峰，峰高与浓度在５×１０－７～２×１０－５ｍｏｌ／Ｌ范围内成线性关系，检测限为２．５×１０－７ｍｏｌ／Ｌ．当ｐＨ值小于３．６０时，ＶＫ３与氢离子作用，于零伏左右有一准可逆的２ｅ－＋Ｈ＋波；当ｐＨ值大于３．６０时，用低扫速的卷积伏安法观察，可发现ＶＫ３有双锋，说明有反应中间体存在，在水合介质中其反应机理是可逆的逐级双电子过程．此外，还对底液中溶解氧的影响进行了讨论．     

注射用甲硫氨酸维生素B1的细菌内毒素检查

为考察注射用甲硫氨酸维生素B1的细菌内毒素检查法的可行性，采用《中华人民共和国药典》（2005年版）细菌内毒素检查法。结果得知，注射用甲硫氨酸维生素B1质量浓度为0．25mg／mL的稀释液可用灵敏度为0．25EU／mL的鲎试剂进行细菌内毒素检查，实验中3个批号的注射用甲硫氨酸维生素B1经检查均符合规定。     

Thiamine pyrophosphate: An essential cofactor for the α-oxidation in mammals – implications for thiamine deficiencies?

The identification of 2-hydroxyphytanoyl-CoA lyase (2-HPCL), a thiamine pyrophosphate (TPP)-dependent peroxisomal enzyme involved in the α-oxidation of phytanic acid and of 2-hydroxy straight chain fatty acids, pointed towards a role of TPP in these processes. Until then, TPP had not been implicated in mammalian peroxisomal metabolism. The effect of thiamine deficiency on 2-HPCL and α-oxidation has not been studied, nor have possible adverse effects of deficient α-oxidation been considered in the pathogenesis of diseases associated with thiamine shortage, such as thiamine-responsive megaloblastic anemia (TRMA). Experiments with cultured cells and animal models showed that α-oxidation is controlled by the thiamine status of the cell/tissue/organism, and suggested that some pathological consequences of thiamine starvation could be related to impaired α-oxidation. Whereas accumulation of phytanic acid and/or 2-hydroxyfatty acids or their α-oxidation intermediates in TRMA patients given a normal supply of thiamine is unlikely, this may not be true when malnourished. Received 23 December 2005; received after revision 10 April 2006; accepted 28 April 2006     

基于有机溶剂中的酶促反应测定血清中维生素C含量

研究了有机溶剂中辣根过氧化物酶催化维生素C的氧化反应的特性。实验发现在异丙醇-水互溶体系中,辣根过氧化物酶催化过氧化氢氧化维生素C的反应速度加快,测定灵敏度提高,基于此反应,用紫外分光光度法测定了人血清中维生素C的含量。