维生素C注射液质量控制因素探讨

目的:探讨影响维生素C注射液质量控制的因素;方法:从原料、辅料、金属离子、活性炭、pH、残留余氧量、温度、投料次序这八个因素进行讨论;结果:每个因素都直接影响维生素C注射液的质量;结论:维生素C注射液的质量控制关键是生产时要对各个因素的控制。     

BP人工神经网络-光度法同时测定VB1、VB2、VB6和VPP

用BP人工神经网络解析了VB1、VB2、VB6和VPP的紫外吸收光谱,提出同时测定这四种维生素的计算分析方法,并对复合维生素片中的VB1、VB2、VB6和VPP进行了同时测定,VB1、VB2、VB6和VPP平均相对误差分别为1.45%,1.57%,4.08%和1.87%.使用了改进的BP算法,避免了神经网络学习过程中可能产生的麻痹现象;提出了目标向量的简单变换方法.     

HPLC法测定维生素C口服液中维生素C的含量

目的:建立HPLC法测定维生素C口服液中维生素C含量的方法。方法:采用C18柱(250×4.6mm,5μm)为色谱柱;0.02mol·L-1醋酸钠缓冲溶液(p H3.5)-乙腈(85:15)为流动相;柱温30℃;检测波长270nm。结果:该方法在0.6095mg·m L-1~1.3207mg·m L-1浓度范围内具有良好的线性关系,R=0.9994;平均回收率为99.51%,RSD(%)=0.73%。结论:该测定方法准确、可行,适用于维生素C的测定,确保了维生素C口服液的质量安全。     

Role of bilirubin, vitamin C and ceruloplasmin as antioxidants in coronary artery disease [CAD]

A study has been carried out on 250 CAD patients to see how the serum levels of three antioxidants i.e., Vitamin C, Bilirubin and Ceruloplasmin are related to the CAD risk factors and characteristics in these patients. The number of severe category CAD patients declined by 7–18% with increasing serum levels of the three antioxidants and, triple vessel disease declined by 14–20%. A decline of 39% in Myocardial Infarction (MI) occurred with increasing serum Ceruloplasmin. Serum Ceruloplasmin was significantly lower in the MI group compared to the non MI group CAD patients. There was a steady and a significant decline in the mean values of serum levels of cholesterol, Triglyceride, VLDL cholesterol along with BMI with increasing serum level. The study indicates that with increasing serum levels of the three antioxidants studied, the % MI along with % Triple vessel disease and severity of CAD goes down suggesting that the modifiable risk factors have to be suitably modified in order to maintain a reasonably high level of these antioxidants, as the risk factors are inversely related to the serum antioxidant levels.     

维生素A生理学效应研究

维生素A与人体生长发育、视觉、生殖及免疫功能有关 ,我国属儿童维生素A中度缺乏国家。本文主要论述了维生素A的生理作用和维生素A缺乏症的预防措施     

Role of vitamin B12 on methylmalonyl-CoA mutase activity

Vitamin B₁₂ is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM’s inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods.     

乌塌菜Vc含量动态变化的初步研究

研究了乌塌菜不同品种、不同生育期、不同叶片、叶柄与叶片的Vc含量.结果表明:乌塌菜不同品种间叶片的Vc含量存在显著差异,但叶柄间的Vc含量差异不大;莲座期叶片的Vc含量均显著高于幼苗期叶片的Vc含量,莲座叶的Vc含量均明显高于心叶的Vc含量,叶片的Vc含量均显著高于叶柄的Vc含量.     

果蔬中维生素C测定方法的比较研究

比较研究2,6-二氯靛酚滴定法与铁（Ⅱ）-邻二氮菲分光光度法测定果蔬中维生素C含量。样品处理后,在最佳条件下测定果蔬中的维生素C含量。滴定法在测定深色样品时欠佳;分光光度法适合于深色样品的测定,但操作繁琐。深色的样品宜选择分光光度法测其Vc含量。     

Evaluation and analysis of the vitamin levels in the self-selected diets of senile diabetics

This study was aimed at evaluating the daily vitamin intakes of senile diabetics whose diets were self-selected in order to apply the data obtained to prevent and treat senile Type 2 diabetics effectively. The daily vitamin intakes of 43 Type 2 diabetics (group A) and 43 healthy non-diabetics (group B) as revealed by their answer to a questionnaire were evaluated by computer analysis and compared with the Recommended Dietary Allowance (RDA). The data obtained in this study showed that the daily vitamin B1 and B2 intakes in both groups were obviously low, less the 50% of RDA; and that in group A was lower than that in group B. The daily intakes of vitamin E and A were significantly different between group A and group B (P<0.01 for vitamin E and P<0.05 for vitamin A). So the vitamin intakes of the senile diabetics with their self-selected diets were inadequate. The author suggests that it is necessary to give a scientific guide for the diets of senile diabetics. If the vitamin intake from foods is inadequate, vitamin supplements should be given to prevent complications.     

维生素E的性质、应用及其市场分析

文章对维生素E的性质及其应用进行了综述,并对维生素E的市场进行了分析。