响应面优化酶法提取莲子心中黄酮类化合物

利用纤维素酶酶解技术对莲子心中黄酮类化合物的提取工艺进行研究。在单因素试验的基础上,根据Box-Behnken试验设计原理,设计三因素三水平的响应面分析法,建立二次多项式回归方程的预测模型,最终确定了酶提取工艺的最佳参数:溶剂50%乙醇,液料比19:1,纤维素酶添加量0.3%,pH5.5,在60℃下酶解2h。实际测得总黄酮得率为4.50%,与理论预测值基本相符。     

麦胚黄酮对实验老鼠血脂水平和脂质抗氧化作用影响的研究

探讨麦胚黄酮(Flavonoids of Wheat Germ,FWG)对大鼠血脂和脂质过氧化作用的影响.方法在建立试验用高脂血症老鼠模型的基础上,观察麦胚黄酮对大鼠血脂水平及血清和组织中脂质过氧化物(LPO)含量、全血中超氧化物歧化酶(SOD)和谷胱甘肽还原酶(GSH-Px)活性的影响.结果麦胚黄酮可明显地降低大鼠血清胆固醇(TC)、甘油三酯(TG)的含量(P＜0.01),提高高密度脂蛋白胆固醇(HDL-C)含量(P＜0.01);麦胚黄酮对高脂血症大鼠具有较强的抗氧化作用,能显著降低血清和组织中IPO含量(P＜0.01),同时明显提高SOD和GSH-Px的活性(P＜0.05).结论麦胚黄酮有调节血脂代谢和提高机体抗氧化能力的作用,对高脂血症有一定的预防作用.     

Effect of two different lipid sources on glass transition temperatures and tensile properties of corn semolina

The effect of adding corn oil (CO) and corn germ (CG) on the thermal and mechanical properties of corn semolina (CS) was investigated. The lipids concentration employed were 2% and 3% of CO or CG. The thermal transitions were studied in a moisture content range of 3–27% (d.b.), by means of dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) techniques. Wide angle X-ray scattering (WAXS) experiments showed that type-V amylose–lipid complexes were formed with the native lipids within the corn semolina during thermo-moulding and that re-crystallization to a type-A structure, favored by the added lipids, occurred upon storage in high relative humidity (RH) environments. Two thermal events were observed during the first DSC scan and tan δ DMTA curves. The first one appearing at around 55–60 °C was attributed to a possible phase separation or ageing phenomenon taking place during storage of the samples, while the second was ascribed to the glass transition temperature of CS. It was found that addition of both, CO and CG, reduced the moisture content required for these transitions to appear. The expected decrease in the glass transition temperatures with moisture content was well described by the Gordon–Taylor equation. The addition of CO and CG also causes plasticization of CS. Hence, corn germ meal can be used as a lipid source that is more convenient to handle than liquid fats. However, the CS T_g values were independent of the lipids content. Tensile properties of CS and CS-lipid systems were found to be influenced by the moisture content, the physical state of the samples, and their composition.     

邻苯二甲酸二(2-乙基)己酯诱导隐睾对SD幼鼠睾丸生殖细胞凋亡的影响

目的探讨环境内分泌干扰物邻苯二甲酸二(2-乙基)己酯[D(i2-ethylhexy1)phthalate,DEHP]作用于SD孕鼠后,对哺乳期雄性幼鼠睾丸组织中生殖细胞凋亡及凋亡基因Bax和Bcl-2表达的影响。方法将30只妊娠第12.5天的SD孕鼠随机分正常对照组、玉米油对照组和DEHP诱导隐睾组,每组10只。玉米油对照组和DEHP诱导隐睾组自妊娠第12.5～19.5天分别每日灌胃玉米油(2 ml)和DEHP(500 mg/kg),正常对照组不给药。取各组出生后第20天的雄性幼鼠睾丸组织,采用Q-PCR法检测睾丸组织中Bax和Bcl-2基因的水平,流式细胞术检测睾丸生殖细胞的凋亡情况。结果 DEHP诱导隐睾组幼鼠睾丸组织中Bax基因mRNA的水平显著高于两对照组(P<0.000 1),Bcl-2基因mRNA的水平显著低于两对照组(P<0.01);DEHP诱导隐睾组幼鼠睾丸生殖细胞凋亡百分率显著高于两对照组(P<0.000 1)。结论孕期暴露环境内分泌干扰物DEHP可引起雄性子代发生隐睾,且隐睾鼠睾丸生殖细胞凋亡率增加,隐睾子代睾丸组织中凋亡基因Bax和Bcl-2的表达有改变,推测其改变可能参与了生殖细胞的凋亡过程,并可能与隐睾继发的远期不育有关。     

微生物降解原油提高原油采收率的研究

从辽河油田的诸多油污土样和水样中分离出若干能以原油为唯一碳源的菌株。将这些菌株经实验室的配伍试验,研制开发出了一种能降解原油提高原油采收率的细菌制剂。该制剂可将原油组分进行有效的生物降解,从而提高了原油的采收率。通过紫外、红外等分析化学的方法,对生物降解后的原油成分及其培养液的变化进行测定。该制剂可使原油的凝固点降低１４℃;粘度降低了８００ＭＰａ·ｓ;ｐＨ降低了２．４个单位;原油降解率为７０．４％,该制剂用于现场试验取得了较为明显的效果。     

Policosanol distribution and accumulation in developing corn kernels

Policosanol is a mixture of long-chain primary aliphatic alcohols. The policosanol composition of whole corn kernel was determined in three varieties of corn (Astro, GH2547, Local). The total policosanol content of GH2547 (20.5 mg/kg of dry weight) was higher than those of Local (16.6 mg/kg) and Astro (15.2 mg/kg). The major policosanol components of whole corn kernel were dotriacontanol, triacontanol and tetracosanol. The distribution of policosanol in the germ, endosperm and pericarp of corn kernels was also determined. Corn pericarp had higher contents of policosanols (72.7–110.9 mg/kg) than the endosperm (4.0–16.2 mg/kg) and germ (19.3–37.1 mg/kg) fractions. Corn pericarp policosanol was mainly triacontanol (33.63–46.29 mg/kg), dotriacontanol (22.31–39.46 mg/kg) and octacosanol (8.13–14.0 mg/kg). In contrast, the corn germ fraction contained mostly dotriacontanol (more than 50%) and no triacontanol. The main components of corn endosperm policosanol were triacontanol and hexacosanol. The level of tetracosanol was highest in the germ fraction and lowest in the endosperm fraction. The greatest change in policosanol content (expressed as mg/100 g of oil) occurred during the early stages of corn kernel development. Although the structures of the alcohol constituents of policosanol are similar, their patterns of accumulation were different. The highest levels of octacosanol and dotriacontanol were detected at 20 days after pollination (DAP) followed by a rapid decrease between 20 and 30 DAP. Triacontanol levels decreased rapidly between 10 and 40 DAP, and then remained nearly constant.     

INDUCTION OF MUTAGENIC EFFECT IN SOMATIC AND GERM CELLS BY ENRICHED URANIUM

Enriched uranium(UO2F2) accumulated in organism could cause chromosome aberrations in somatic cells, its rates on bone marrow cells were elevated when the dose of 235UO2F2 was increased. Among the types of induced aberrations, chromatid breakage was predominant, accompanied with a few chromosome breakage and translocation. At the same time mitosis index of metaphase cells was depressed. Chromatid delation and chromatid exchange were induced in peripheral blood lymphocytes. The important type of aberrations in spermatogonia was break. For primary spermatocytes the most significant aberration was multivalents which resulted either from chromatid interchanges or reciprocal translocations. 235UO2F2 could result in DNA breakage in germ cells. The sensitivity of germ cells at various stages to 235UO2F2. was different. At 12d after exposure the amount of sperm DNA eluted reached the peak. When the treating time was fixed, elution of sperm DNA from treated animals increased with the increasing doses. 235UO2F2. could also result in sperm abnormalities. Especially at 13 to 36 d after treatment the rates of sperm abnormalities were significantly elevated.     

小剂量辐射诱导小鼠精母细胞适应性反应某些规律的研究

采用小剂量γ射线慢性照射和Ｘ射线分次照射，整体照射雄鼠，照射后４０ｄ，给予１．５Ｇｙ的Ｘ射线照射。通过分析初级精母细胞的染色体畸变，观察预先小剂量照射（Ｄ１）对第二次大剂量辐射损伤的影响。结果表明；小剂量γ射线和Ｘ射线均能诱导小鼠精母细胞适应性反应。     

^125I诱发小鼠生殖细胞染色体畸变效应观察

本文选用ICR小鼠为实验动物,腹腔注射不同剂量~(125)I,研究其对小鼠生殖细胞染色体畸变发生率影响及动态变化规律。实验结果显示:(1)~(125)I染毒(555kBq)后1d染色体畸变率最高,精原细胞和精母细胞染色体畸变率均为1.8％,但畸变率随时间延长而迅速降低。(2)~(125)I染毒后1d,0、175、555及1665kEq各组精原细胞染色体畸变率分别为0.14％、0.45％、1.80％及2.65％;精母细胞染色体畸变率分别为0.13％、0.60％、1.80％及2.20％,经行列X~2检验,各组间差别均有显著意义。本文结果进一步揭示了~(125)I对哺乳动物有潜在的遗传危害。