党参总皂苷的提取·分离和纯化

[目的]优化党参皂苷的提取工艺,并对皂苷进行纯化.[方法]用正交试验优化党参皂苷的提取工艺,通过考察大孔树脂类型、洗脱液pH值对党参皂苷纯度的影响,优化皂苷的纯化方法.[结果]党参皂苷提取的最佳工艺为:提取时间为36 h,提取温度为45 ℃,料液比为1:6;D101大孔吸附树脂为党参皂苷吸附的最佳树脂,洗脱液pH值为9左右时,得到的皂苷浓度最高.[结论]该试验得到了较高纯度的党参皂苷,为获得高纯度党参皂苷提供了保证.     

一种快速微量提取柑橘早期胚基因组DNA的方法

[目的]建立一种快速微量提取柑橘基因组DNA的方法.[方法]采用优化的CTAB微量提取法,以20.0、10.0,5.0、2.5 mg 早期杂种胚为材料进行基因组DNA的提取,并对其DNA进行质量检测和SSR验证.[结果]该方法简单易行,所需材料少,提取的DNA纯度较高,OD260nm/OD280nm在1.800～2.000,可满足SSR等以PCR扩增为基础的试验需要.[结论]建立的方法可以用于快速微量提取柑橘基因组DNA.     

超声波辅助提取络石藤总黄酮的工艺研究

[目的]优化超声波辅助提取络石藤中总黄酮的工艺.[方法]以总黄酮含量为考察指标,采用正交试验设计研究超声波辅助提取络石藤总黄酮的最佳工艺条件.[结果]最佳提取工艺为乙醇浓度60%、反应温度70 ℃、超声时间30 min、料液比1:15;在此条件下,总黄酮的提取率为3.22%.[结论]优化后的工艺简便可行,可为络石藤总黄酮提取纯化工艺的产业化提供理论依据.     

剑麻皂素的分离纯化工艺研究

[目的]研究从剑麻(Agave sisaiana Perrine)中提取与分离纯化剑麻皂素的工艺.[方法]采用常规的硫酸加热回流提取法,提取剑麻皂素粗提物,用大孔径树脂分离纯化剑麻皂素,并确定最佳提纯工艺条件.[结果]用D-101树脂分离效果较好,最佳分离纯化工艺条件是,洗脱液浓度为70%乙醇,用量100ml,洗脱速度0.6ml/min.在此条件下,剑麻皂素得率为79.1%,纯度为71.6%.[结论]该试验研究工艺技术上可行,原料价廉适合工业化生产.     

微量DNA高效提取方法

[目的]探究一种高效的提取微量地衣体及地衣共生菌DNA的方法.[方法]在CTAB法的基础上,对溶液成分、比例及应用硅基质吸附柱对微量DNA提取进行优化.[结果]对于叶状、枝状和壳状地衣,采用该方法可得到质量较高的DNA.[结论]所用方法既节约样品,简便易行,费用低,稳定性好,效率高,而且不局限于新鲜材料.     

梅花鹿心脏组织cDNA文库的构建

[目的]构建梅花鹿心脏cDNA文库.[方法]提取梅花鹿心脏总RNA,纯化mRNA;合成双链cDNA,连接载体,并电转化至感受态细胞;测定文库的克隆数、重组率及插入片段大小.[结果]经鉴定,所构建梅花鹿心脏组织cDNA文库,库容量为3.8×106个克隆,重组率为100%,插入片段大小为0.5～2.0 kb,平均长度约为1.0 kb.[结论]所构建cDNA文库的各项指标均达到要求.     

传染性法氏囊病病毒VP5蛋白跨膜区的敲除及可溶性原核表达研究

[目的]构建敲除传染性法氏囊病病毒(IBDV)VP5蛋白跨膜区序列的原核表达载体,并进行目的蛋白的表达、分离和纯化.[方法]利用PCR技术分别扩增IBDV VP5基因的胞外片段和胞内片段,然后将2个片段及pET-28b+)同时相接,即载体-胞内片段-胞外片段-载体,构建了敲除跨膜区基因片段的VP5重组表达质粒pET-VP5-FC及改进后的pET-VP5-SC.将表达质粒转化B121(DE3),IPTI;诱导后经Ni亲和层析及凝胶过滤层析纯化重组蛋白.[结果]得到可溶性表达的IBDV VPS.[结论]为进一步研究VP5蛋白的结构与功能奠定了基础.     

正交试验法优化细叶黄皮叶中叶绿素的提取工艺

[目的]优化细叶黄皮叶(Clausena anisum-olens)中叶绿素的提取方法,为细叶黄皮叶中叶绿素的分离纯化奠定基础.[方法]在单因素试验的基础上,采用L<,9>(3<'4>)正交设计法优化细叶黄皮叶中叶绿素的提取工艺.[结果]微波萃取细叶黄皮叶中叶绿素的最佳工艺条件为:提取剂95%乙醇,料液比1:10,温度70℃,功率为350 W,提取时间7 min.[结论]该试验优化的提取工艺简便、高效,为细叶黄皮叶中叶绿素的开发利用奠定了基础.     

四角蛤蜊糖胺聚糖的分离纯化及功能活性研究

[目的]研究四角蛤蜊糖胺聚糖(GAG)的功能.[方法]从四角蛤蜊的软体部中提取粗GAG、并纯化,对纯化的GAG进行功能分析.[结果]从四角蛤蜊的软体部中提取的GAG,经2 次纯化,纯度达到95.03%.纯化的GAG对羟基自由基和超氧阴离子自由基有较强的清除作用,但比Vc 作用弱;具有较强的抗凝血能力,但活性弱于肝素钠.[结论]GAG 具有较强的清除羟基自由基和超氧阴离子自由基作用及抗凝血能力.     

Taq DNA聚合酶的热纯化制备

[目的]提高Taq DNA聚合酶的制备效率.[方法]利用Ni柱亲和色谱纯化载有6xHis标记的Taq DNA聚合酶,并重组载体,利用Taq DNA聚合酶的耐热特性,对粗提液75℃处理1h,之后通过PCR试验验证制备酶液的活力.[结果]所获重组的pET-32A-Taq能够在BL21(DE3)宿主菌中高效表达并可通过热变性去除杂蛋白,获得了活力远高于购买的Taq DNA聚合酶的酶制剂.[结论]使用热纯化法制备的Taq DNA聚合酶工艺简单,成本较低,能满足常规大量PCR实验要求.     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Rehabilitation of disorders of the breaking of voice

The adolescent's breaking of the voice is the result of the substitution of the chest voice (or heavy mechanism) for the head voice (or light mechanism). In cases of late breaking, the voice is abnormally high-pitched and feeble, often with a distorted timbre, while the larynx is normal and pubescent. Such people are generally not fully aware of their voices' real nature. Therapy classically resorts to laryngeal manipulations, of which a new technique is put forward. Another therapeutic approach is based, on the one hand, on critical listening compared with a control male voice, thus enabling the subject to become aware of his own voice, and, on the other hand, on high intensity work which helps passing from head to chest voice.