黄绿木霉菌诱变菌株的初步研究

通过对木霉的孢悬液进行紫外线和亚硝酸钠复合诱变，经刚果红培养基鉴定筛得5株突变菌株。利用液体培养发酵，对各菌株的CMC酶活测定发现，其中Ⅱ号：Ⅲ号突变菌株的CMC酶活分别比原菌株提高了150％和65％，并均具有很好的抗葡萄糖阻遏效应。     

Potato tuber sugars, starch and organic acids in relation to ozone exposure

Summary Data from two Swedish and one Finnish open-top chamber experiments were combined to investigate effects of ozone exposure on potato (Solanum tuberosum L.) tuber content of starch, sucrose, fructose, glucose, malic, citric and ascorbic acids. The glucose, fructose and malic acid concentrations showed strong negative correlations with ozone exposure, while citric acid, consistently increased with ozone exposure. No ozone effects could be demonstrated on starch, sucrose or ascorbic acid concentrations. It is discussed to what extent the changes found in potato tuber composition can be explained in terms of ozone effects on tuber maturity. Ozone exposure was expressed as the accumulated exposure over a cut-off concentration of 40 nmol mol⁻¹ (AOT40) and as the accumulated uptake of ozone over an ozone uptake rate threshold of 7 nmol m⁻² s⁻¹ (CUO 7). The difference in ability of the exposure indices to explain observed effects was small.     

葡萄糖水热过程中焦炭结构演变特性

为了解生物质水热炭化过程中焦炭的形成机制及其理化结构的演变机理,该文以葡萄糖为原料,利用高温高压反应釜,对葡萄糖在水热环境中炭化的反应过程和焦炭的表面物理结构及微观化学组成进行了系统的分析。研究发现,葡萄糖经过水热处理,可以获得富含炭微球的无定形水热焦炭,这些炭微球粒径分布在0.6～7 μm之间,而通过控制水热过程的温度、葡萄糖添加量和停留时间,则可对其收率、形貌、化学组成等理化性质产生重要影响。在220℃,4 h,6 g/100 mL的水热条件下,炭微球粒径最小且均匀,平均粒径约为1.54 μm;在220℃,4 h,12 g/100 mL的水热条件下,焦炭收率最高为38.92%。水热焦炭中含有大量的芳香环结构和含氧官能团,具有很强的亲水性,其表面碳化程度高于内核。水热焦炭的形成主要是一系列脱水、聚合、凝结、芳香化、胶体作用的结果。研究结果为生物质水热法制备炭微球的过程控制提供参考。     

鸡腿蘑发酵液与钒酸钠协同抑制小鼠血糖升高作用的研究

研究了鸡腿蘑发酵液与钒酸钠混合液对肾上腺素造成高血糖小鼠的血糖水平的影响，研究表明：该溶液能明显抑制小鼠血糖的升高。     

Lipid biosynthesis from [14C]-glucose in the coral Montipora digitata

ABSTRACT:     Glucose has been implicated in functioning as a form of carbon translocated from symbiont zooxanthellae to the host coral cell. The present paper describes the lipid biosynthesis from [¹⁴C]-glucose in the coral tissue. To study the incorporation of [¹⁴C]-glucose into lipids, the branch tips of the coral Montipora digitata were incubated with [¹⁴C]-glucose or another radiolabeled substrates. The lipid biosynthesis from [¹⁴C]-glucose was dependent on light, and was decreased by dark conditions or by photosystem II inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Of the lipid classes, the light dependency was more pronounced with the biosynthesis of triacylglycerols (TG) and wax compared with phospholipids. Examination of [¹⁴C]-label distribution in the glycerolipids suggested that [¹⁴C]-glucose supplied mainly the fatty acid moiety of newly synthesized TG, while [¹⁴C]-glucose provided evenly the fatty acid moiety and the glycerol skeleton of phospholipids. The comparison of [¹⁴C]-labeling of lipid from host coral tissue and symbiont zooxanthellae suggested that [¹⁴C]-glucose entered the coral cell and was processed in parallel in the zooxanthellae and host cells. Furthermore, the coral cells used various [¹⁴C]-labeled sugars for lipid synthesis with similar lipid labeling profile as was the case for glucose. The current study thus supports the view that the low-molecular-weight compound, sugars and amino acids, once translocated from zooxanthellae to host cell were metabolized toward lipogenesis as well as glycerol.     

全自动换血治疗G-6-PD缺陷症并发急性溶血的疗效观察

目的 :观察全自动换血治疗危重G 6 PD缺陷症并发急性溶血的疗效。方法 :对 1 0例危重G 6 PD缺陷症并发急性溶血采用全自动换血治疗。结果 :总胆红素由换血前 (5 33.1 4± 1 1 5 .6 5 ) μmol/L下降至换血后 (2 95 .5 0± 88.5 1 )μmol/L ,换出率是 4 4 .5 7% ,血红蛋白增加 34.1 2 % ,红细胞增加 4 3.30 % ,换血过程无明显不良反应。结论 :全自动换血是抢救危重G 6 PD缺陷症并发急性溶血的简单、实用、安全、有效的方法     

Evaluation of Root Sink Ability of Sweet Potato (Ipomoea batatas Lam.) Cultivars on the Basis of Enzymatic Activity in the Starch Synthesis Pathway

Activities of five enzymes, sucrose synthase (SUS), uridine 5'-diphosphate glucose pyrophosphorylase (UDPGPPase), fructose-1,6 bisphosphatase (FBPase), adenosine 5'diphosphate glucose pyrophosphorylase (ADPGPPase) and starch synthase (STS), in the metabolic pathway of starch synthesis, were compared between two sweet potato ( Ipomoea batatas Lam.) cultivars, Koganesengan (C.V.KOG, a recently released high yield cultivar) and Tsurunasigenji (C.V.TSU, an old, local cultivar with poor yield). The measurements were carried out using the root samples (tuberous, thick and fibrous roots) harvested at the fast tubering stage. Of the five enzymes, SUS, ADPGPPase and STS showed high activities in the tuberous root, particularly in that of C.V.KOG, and a similar trend was observed for activities of these enzymes on a protein basis. The increased activity of the three enzymes is considered to be one of the characteristics in a high yield cultivar, allowing the root to function effectively as a starch synthesis and storage organ.     

Variations in parameters of liver function and plasma progesterone related to underfeeding and ketosis in a dairy herd

Twenty-eight Norwegian Red Cattle dairy cows were fed silage ad libitum and restricted amounts of concentrates. Blood samples were collected before morning feeding, once or twice weekly, from 2 weeks before to 12 weeks after calving. Parameters of liver function, carbohydrate status and fertility were recorded in order to assess their interrelationships. Eight cows were treated for clinical ketosis. Four of these had to be treated 2 or 3 times. Aspartate aminotransferase and bilirubin showed the highest within-animal coefficients of correlation with acetoacetate. Analysis of variance revealed a significant effect of carbohydrate status (indicated by plasma acetoacetate levels) on the levels of aspartate aminotransferase, glutamate dehydrogenase and sorbitol dehydrogenase, though only a small part of the total variation was explained by this factor. The estimated volume density of liver fat in the 4th week of lactation averaged 6.0 +/- 6.4% (+/- SD) ranging from 0.1-25.1%. Liver fat content at this stage of lactation was not significantly correlated with other indicators of liver function or carbohydrate status. Cows treated for clinical ketosis had significantly lower plasma progesterone values at the time of first ketosis treatment than untreated multiparous cows. The frequency of high progesterone values (greater than 3 ng/ml) being significantly lower in treated than in untreated cows during the period from 3-5 weeks post partum, though not at later stages. In conclusion, the results revealed a significant relationship between carbohydrate status and liver function, and also between clinical ketosis and luteal function.     

瘤胃源益生菌对小鼠生长和生理特性的影响

试验旨在对筛选出的6种瘤胃源益生菌进行小鼠试验,以期为其在畜禽养殖业的进一步开发和利用提供参考依据。选取5周龄雄性昆明小鼠56只,随机分为7组：生理盐水对照组、解淀粉芽孢杆菌Lw-J21组、枯草芽孢杆菌Lw-K16组、乳酸菌Lw-R35组、产蛋白酶菌Lw-D48组、产纤维素酶菌Lw-X21组和酵母菌Lw-JM70组,试验组每天以0.2 mL/10 g体重剂量连续灌胃42 d,对照组灌喂相同剂量的生理盐水,比较并分析灌胃不同益生菌对小鼠体重、肠道菌群数量、脂肪积累量、免疫器官指数和血糖降解能力等的影响。结果显示,与对照组相比,解淀粉芽孢杆菌Lw-J21和产纤维素酶菌Lw-X21组小鼠体重增加明显（P>0.05）,同时可显著减少小鼠体内的脂肪积累（P<0.05）。乳酸菌Lw-R35和产纤维素酶菌Lw-X21组小鼠肠道中的乳酸菌和总厌氧菌数量均显著或极显著增多（P<0.05;P<0.01）。各益生菌组小鼠脾脏指数和胸腺指数均有显著或极显著提高（P<0.05;P<0.01）,且可不同程度提高小鼠血糖的调节能力。综上所述,用筛选出的6种天然益生菌饲喂小鼠可改善其肠道微生态环境、免疫器官指数和血糖调节能力等。     

Effects of p.o. administered xylitol in cats

Xylitol is commonly used as sugar substitute in households. While it has numerous beneficial effects on human health, it is highly toxic to dogs. The goal of this study was to examine whether xylitol has similar deleterious effects, such as hypoglycaemia and acute hepatic failure, on cats. Our research included six healthy middle‐aged cats. Xylitol was dissolved in deionized water and administered p.o. at three doses (100, 500 and 1,000 mg/kg body weight). These dosages have been considered toxic and can cause liver failure or even death in dogs. After every xylitol administration, the basic health status and the blood glucose of cats were observed regularly. Additionally, prior to and 6, 24 and 72 hr after xylitol administration, blood samples were taken to check complete blood count, clinical biochemical parameters and enzymes such as ALT, ALKP, GGT, GLDH, bile acids, BUN, creatinine, phosphate, total protein, albumin, sodium and potassium. There were no significant changes (p > .05) in any of the haematological or biochemical parameters. Blood glucose concentrations did not show any significant alterations, except at 1,000 mg/kg dose, where a mild but significant increase was observed, but it was in physiological range. Based on our results, xylitol did not induce toxic effects on cats.