影响浓盐法提取啤酒酵母RNA的工艺参数研究

以啤酒酵母为原料,通过浓盐法进行RNA提取的研究.考察了影响RNA提取率的因素,如提取温度、提取时间、加盐量及酵母质量浓度,获得了最大提取率的条件:提取温度95 ℃,提取时间为60 min,氯化钠的加入量为10%,酵母质量浓度为10%.正交实验表明加盐量为反应过程的显著因素.在上述条件下,90 g湿酵母(相当于20 g干酵母)能够提取1 g RNA,A260/A280是1.983.对RNA粗品进行精制,得到固体的白色粉末.     

浓盐法提取啤酒酵母中核糖核酸的工艺参数研究

以啤酒酵母为原料,通过浓盐法进行了核糖核酸(RNA)提取的研究,对影响RNA提取率的因素,如提取温度、提取时间、加盐量及酵母质量浓度进行了考察,获得了最大提取率的条件：提取温度95℃,提取时间为60min,氯化钠的加入量为10%,酵母质量分数为10%。正交实验表明,加盐量为反应过程的显著影响因素。在上述条件下,90g湿酵母(相当于20g干酵母)能够提取1g RNA,A260/ A280是1．983。对RNA粗品进行精制,得到固体白色粉末。     

栝楼籽蛋白质提取工艺优化及抗氧化性

以栝楼籽为原料,采用超声波辅助碱法提取栝楼籽蛋白质。通过单因素实验方法和正交实验方法确定了最佳提取工艺条件;考察所得栝楼籽蛋白质对DPPH自由基和羟基自由基的清除能力。结果表明,栝楼籽中超声波辅助碱法提取栝楼籽蛋白质的最佳提取工艺为:料液比为1∶30(g∶m L),提取液为0.7 mol/L氯化钠碱液(p H=10),在70℃下用200 W超声辅助提取30 min,栝楼籽中蛋白质提取率可达到22%左右。当栝楼籽蛋白质溶液质量浓度为0.8 g/L时,对DPPH自由基的清除率为66.46%,对羟基自由基的清除率为49.23%,其清除能力随其质量浓度的增大而增强;其清除能力强于柠檬酸而弱于抗坏血酸。     

循环超声强化提取肉苁蓉中多糖和甜菜碱

研究了循环超声强化提取肉苁蓉中多糖和甜菜碱的工艺条件. 实验结果表明，将肉苁蓉粉碎至40目，液固比为60 ml/g时提取较为适宜. 循环超声提取多糖和甜菜碱的较优工艺条件是：提取温度40℃，超声功率1000 W，提取时间10 min，在此条件下，多糖的提取量为46.9 mg/g，甜菜碱的提取量为136.5 mg/g，分别相当于沸水回流7 h时提取量的107.3%和103.8%.     

杏鲍菇菌糠蛋白质的提取工艺研究

为了更好地利用杏鲍菇菌糠加工副产物,通过单因素实验法探讨料液比、氢氧化钠浓度、提取温度和提取时间对杏鲍菇菌糠蛋白质提取率的影响,采用正交实验法确定杏鲍菇菌糠蛋白质提取的最佳工艺条件。结果表明,各个因素对杏鲍菇菌糠蛋白质提取率的影响为料液比氢氧化钠浓度提取温度提取时间,在提取时间2. 5 h,提取温度50℃,料液比为1∶40,氢氧化钠浓度0. 7 g/100 mL的条件下杏鲍菇菌糠蛋白质碱法提取率达到最大值19. 84%。     

井栏边草中齐墩果酸含量的测定及其提取工艺优化

为探究井栏边草中齐墩果酸的含量情况,使用紫外-可见分光光度法对其含量进行测定。测定结果为:在40℃的条件下利用超声仪将1g井栏边草用无水乙醇提取90min所测得的含量为0. 113mg/g,即1g干草中含有0. 113mg齐墩果酸。通过正交试验,有效影响到齐墩果酸含量的因素有超声提取时间、超声提取温度、乙醇浓度,其的影响效果依次降低,最优水平为A2B2C3或A2B3C3。即当超声提取温度为50℃,提取时间为150min,溶剂乙醇的浓度为95%或100%,所测得齐墩果酸含量为0. 162mg/g。     

微波辐射提取洋葱中黄酮类化合物

利用微波法提取洋葱中黄酮类化合物。实验表明,最佳工艺提取条件为:反应温度80℃,提取时间15 min,乙醇体积分数70%,料液比1∶10(g/mL),微波功率500 W。在此条件下,黄酮类化合物的提取量为38.90 mg/10 g。     

新橙皮苷的提取及鉴定

通过条件试验,确定了以95%甲醇为提取剂的新橙皮苷索氏提取工艺条件,即橙皮渣与提取剂的料液比为1 g:10 mL,在水浴温度90℃条件提取4 h,提取浓缩液的pH控制在4～5;在此条件下产品收率为0.65%～0.68%.产品经熔点测定和光谱鉴定,结果与文献一致.     

蛋白酶/热压力处理对污泥脱水性的影响

比较不同处理方式对污泥脱水性能及蛋白质提取效率的影响。通过热压力、蛋白酶、热压力-蛋白酶3种方式对机械脱水污泥进行处理。结果表明,在65℃、75℃热压力（3MPa、6MPa、9MPa）下,与原污泥相比蛋白质提取量平均增加41.74%、65.64%;热压力处理后污泥脱水性改善不明显。胃蛋白酶添加量为0.04g/g TSS时,蛋白质提取量最高为108.52mg/g TSS,污泥毛细吸水时间（CST）为最小值154s。65℃热压力（3MPa、6MPa、9MPa）-胃蛋白酶、中性蛋白酶处理后,蛋白质提取量与热压力污泥相比分别提高了38.5%和35.8%;75℃、85℃热压力（3MPa、6MPa、9MPa）-木瓜蛋白质酶处理后,蛋白质提取量均达到220mg/g TSS以上;热压力-胃蛋白酶在75℃,6MPa脱水效果最好,毛细吸水时间为170s。     

基于发酵液特性的透明质酸提取预处理工艺

为进一步提高透明质酸成品质量和提取收率,针对透明质酸发酵液中菌体和蛋白质的物化特性,采用25 g/L三氯乙酸灭活菌体并使蛋白质变性沉淀,以发酵液质量1.2%的混合硅藻土(粗细硅藻土比为1.5:1)为过滤助剂,过滤温度60℃,pH 7.0的发酵液预处理工艺提取透明质酸成品. 再配以酒精沉淀、气浮、酒精造粒的后处理工艺,所得成品透明质酸中葡萄糖醛酸含量达46.39%,蛋白质含量仅为0.047%,分子量为190万,提取收率为91.3%.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。