武昌鱼脂肪酸的气相色谱-质谱分析

为了研究武昌鱼中脂肪酸的组成及含量,采用Bligh-Dyer提取法对样品中脂肪油进行提取,甲酯化后利用气相色谱-质谱联用仪进行分析测定．结果发现从武昌鱼中鉴定出14种脂肪酸,其中饱和脂肪酸5种,相对百分含量占总检出量的28．46％;不饱和脂肪酸9种,相对百分含量占总检出量的71．27％．     

油酸三乙醇胺皂化物的合成

采用单因素控制变量法,以扣除酸值后的皂化值为评价指标,研究了反应配比、反应温度、反应时间对合成油酸三乙醇胺皂化物的影响。结果表明,油酸和三乙醇胺配比为1.2∶1(mol/mol)、温度为130℃、反应时间为3h时,反应达到平衡时体系中油酸三乙醇胺皂化物的含量最多。利用合成的油酸三乙醇胺皂化物调配成的水基润滑油符合相关要求。     

毛细管电泳法测定马齿苋中的有效成分含量

就毛细管电泳法分析马齿苋中的二羟基苯丙氨酸的含量做一探讨，并讨论磷酸盐缓冲液浓度及SDS浓度对分离的影响。     

Oxidative Stress-Induced Response of Some Endogenous Antioxidants in Schizophrenia

Reactive oxygen species (ROS) formed in various metabolic reactions cause unlimited damage by attacking and oxidizing the macromolecules. An arsenal of antioxidant substances neutralizes these ROS at various sites of their metabolic cascade, and if disequilibrium exists between the pro and antioxidant system, oxidative stress persists. The present study was undertaken in schizophrenia, to highlight the response and role of some endogenous antioxidants viz. reduced glutathione (GSH), bilirubin, total proteins, albumin and uric acid in scavenging the ROS. The effect of severity of disease, age factor, and substance abuse was also studied. In all, 50 schizophrenics and 50 age and sex-matched controls were enrolled in the present study. Fasting blood samples were drawn for estimating malondialdehyde (MDA), GSH, bilirubin, total proteins, albumin and uric acid in both the groups. The results were statistically analyzed by Z-test and correlated using correlation coefficient (r). The study shows reduction in MDA levels and decline in the level of endogenous antioxidants, but within the normal range. Chronic schizophrenics were at a higher risk of oxidative stress and age and substance abuse seems to worsen the situation.     

胸腺肽聚乳酸微球的制备和体外释药研究

为了寻找适于多肽分子吸收,免疫学上"有效"、"安全",且服用方便的口服制剂,用W/O/W型乳化挥发法制备胸腺肽聚乳酸微球,正交实验方法优化了制备工艺.通过差热分析证明载药微球已较好形成,Lowry法测定药物的含量,计算微球的载药量、包封率及体外释药量.结果表明,所得微球平均粒径为13.8 μm,平均包封率为80.7%,前12 h的体外释药符合Higuchi方程,T1/2=295 min,在25℃和40℃分别放置90d,微球的粒径分布和剩余药量无显著变化.微球的载药量和包封率符合要求,释药半衰期长,具有良好的应用前景.     

小鼠实验性缺氧脑和肺组织MDA、LD及LDH的变化(英文)

目的：探讨小鼠实验性缺氧脑和肺组织丙二醛（Malondialdehyde,MDA）、乳酸（Lactic acid,LD）含量和乳酸脱氢酶（Lactate dehydrogenase,LDH）活性变化。方法：18只小鼠随机分为3组,①正常对照组;②急性缺氧组;③急性一氧化碳染毒组。分别测定脑和肺组织MDA、LD、LDH含量和活性。结果：急性缺氧组和急性一氧化碳染毒组小鼠脑和肺组织MDA和LD含量显著增高。LDH活性在两实验组小鼠肺组织显著降低,而在脑组织无显著性改变。结论：MDA和LD含量在缺氧早期脑和肺组织是易变化性指标,其改变可能与该组织损伤程度有关。肺较脑对缺氧产生的自由基损伤更敏感。     

Development of a chemically defined medium for Planctopirus limnophila to increase biomass production

BackgroundPlanctomycetes is a phylum of biofilm-forming bacteria with numerous biosynthetic gene clusters, offering a promising source of new bioactive secondary metabolites. However, the current generation of chemically defined media achieves only low biomass yields, hindering research on these species. We therefore developed a chemically defined medium for the model organism Planctopirus limnophila to increase biomass production.ResultsWe found that P. limnophila grows best with a 10 mM sodium phosphate buffer. The replacement of complex nitrogen sources with defined amino acid solutions did not inhibit growth. Screening for vitamin requirements revealed that only cyanocobalamin (B12) is needed for growth. We used response surface methodology to optimize the medium, resulting in concentrations of 10 g/L glucose, 34 mL/L Hutner’s basal salts, 23.18 mM KNO₃, 2.318 mM NH₄Cl and 0.02 mg/L cyanocobalamin. The analysis of amino acid consumption allowed us to develop a customized amino acid solution lacking six of the amino acids present in Aminoplasmal 10%. Fed-batch cultivation in a bioreactor using the optimized medium achieved a final ΔOD₆₀₀ of 46.8 ± 0.5 after 108 h, corresponding to a cell dry weight of 13.6 ± 0.7 g/L.ConclusionsThe optimized chemically defined medium allowed us to produce larger amounts of biomass more quickly than reported in earlier studies. Further research should focus on triggering P. limnophila biofilm formation to activate the gene clusters responsible for secondary metabolism.How to cite: Kruppa OC, Gerlach D, Fan R, et al. Development of a chemically defined medium for Planctopirus limnophila to increase biomass production. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.002.     

灵芝孢子粉多糖含量测定探讨

药理表明,灵芝多糖是灵芝中的主要成分,故对灵芝多糖含量测定方法的研究具有重要的意义。目前,用苯酚-硫酸法测定其多糖含量准确度高,平均回收率为99.08%,RSD=1.68%。测定中显色的最佳条件为:5%的苯酚1.6ml,浓硫酸8ml,温度为20℃,反应时间为24分钟。再分别用乙醇和水进行提取。该方法适合多糖含量的测定,并具有操作简单快速、重现性好等优点。     

家蚕丝素凝胶固定化细胞生产L-天门冬氨酸的研究

作者用家蚕丝素制成丝素溶液,加人大肠杆菌细胞混匀凝固后,再用戊二醛固定和交联,制成固定化细胞丝素凝胶,用于转化延胡索酸为L-天门冬氨酸。测定了固定化细胞转化率和转化效率。实验结果表明,通过控制底物的流速,可使转化率达到95％以上。在转化率为95％时,达到最大转化效率,产率为6．31g/h。连续使用一个月转化原活力仍保持在92％以上。     

水杨酸戊酯的催化合成

以对甲苯磺酸为催化剂，通过水杨酸和戊醇酯化反应合成水杨酸戊酯、研究了催化剂用量、酸醇物质的量比以及反应时间等因素对水杨酸酯化率的影响．实验结果表明，对甲苯磺酸是合成水杨酸戊酯的良好催化剂．在酸醇物质的量比为1：1．6，催化剂用量为6％，带水剂甲苯10mL，反应时间5h，反应温度120～140℃的条件下，水杨酸的酯化率可达94．1％．