蛋白质去折叠路径的分子动力学模拟

蛋白质的去折叠有多条路径,而不是沿着一条特定的路径进行.利用分子动力学模拟技术,模拟蛋白质在高温下的去折叠过程,分析讨论了蛋白质折叠的多路径性.     

4-AAP试剂提纯对水样挥发酚测定的影响

在水环境监测中采用4-氨基安替比林（4-AAP）法测定挥发酚，但4-AAP试剂易被氧化颜色加深，空白值显著增高，对测定结果有较大影响．为此用氯仿萃取、活性炭吸附、苯浸洗3种方法对4-AAP试剂进行提纯，其空白值由提纯前的0．086分别降为0．054，0．018，0．015，相对标准偏差（RSD）由提纯前的6．9分别降为2．2，3．6，2．7．     

审美体验的效用

审美体验的效用是多方面、多层次的。审美体验是开放性的体验。效用和需要相互作用、相互影响。审美体验产生何种效用取决于人的精神需求。随着人的精神需要的增长和变更 ,审美体验的效用也会增长和变更。审美体验是人的生存和发展的需要 ,是人的解放和自由的需要 ,是人超越生命的需要。     

米糠抗氧化肽的分离纯化研究

以DEAE-52离子交换柱层析和SephadexG-25凝胶过滤柱层析纯化米糠抗氧化肽,以硅胶G薄层层析测定其纯度,氨基酸自动分析仪测定其氨基酸组成。实验结果表明:米糠抗氧化肽经DEAE-52柱层析和Sephadex G-25柱层析后基本上得到了纯化;氨基酸组成分析表明,米糠抗氧化肽由14种氨基酸组成,富含两种酸性氨基酸:Asp、Glu,并含有6种人体必需氨基酸(Val、Met、Ile、Leu、Phe、Lys),占米糠抗氧化肽氨基酸总含量的31.89%,具有较高的营养价值和保健功能。     

Serum protein fingerprinting coupled with artificial neural network distinguishes glioma from healthy population or brain benign tumor

To screen and evaluate protein biomarkers for the detection of gliomas (Astrocytoma grade Ⅰ-Ⅳ) from healthy individuals and gliomas from brain benign tumors by using surface enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF-MS) coupled with an artificial neural network (ANN) algorithm. SELDI-TOF-MS protein fingerprinting of serum from 105 brain tumor patients and healthy individuals, included 28 patients with glioma (Astrocytoma Ⅰ-Ⅳ), 37 patients with brain benign tumor, and 40 age-matched healthy individuals. Two thirds of the total samples of every compared pair as training set were used to set up discriminating patterns, and one third of total samples of every compared pair as test set were used to cross-validate; simultaneously, discriminate-cluster analysis derived SPSS 10.0 software was used to compare Astrocytoma grade Ⅰ-Ⅱ with grade Ⅲ-Ⅳ ones. An accuracy of 95.7%, sensitivity of 88.9%, specificity of 100%, positive predictive value of 90% and negative predictive value of 100% were obtained in a blinded test set comparing gliomas patients with healthy individuals; an accuracy of 86.4%, sensitivity of 88.9%, specificity of 84.6%, positive predictive value of 90% and negative predictive value of 85.7% were obtained when patient's gliomas was compared with benign brain tumor. Total accuracy of 85.7%, accuracy of grade Ⅰ-Ⅱ Astrocytoma was 86.7%, accuracy ofⅢ-Ⅳ Astrocytoma was 84.6% were obtained when grade Ⅰ-Ⅱ Astrocytoma was compared with grade Ⅲ-Ⅳ ones (discriminant analysis). SELDI-TOF-MS combined with bioinformatics tools, could greatly facilitate the discovery of better biomarkers. The high sensitivity and specificity achieved by the use of selected biomarkers showed great potential application for the discrimination of gliomas patients from healthy individuals and glioma from brain benign tumors.     

分子伴侣的作用探析

分子伴侣不仅是一大类在蛋白质折叠、组装、复性、转运和降解等方面具有重要功能的蛋白质,随着研究的深入,还发现分子伴侣而且是在病毒感染、DNA复制、转录、抗衰老和信号转导等方面也具有重要的功能,本文对此进行了综述。     

论白居易《长恨歌》中诗“情”的位移与纯化

白居易主张"美刺"的诗学观,但在《长恨歌》中这一诗学原则与诗人情感发生了悖谬,表现为《长恨歌》中诗人情感的位移。诗开头诗人对玄宗溺女色荒朝政深感痛心;但描述杨妃之死却表现出辩证的历史感,既觉咎由自取,也深感历史无情;而后描写玄宗缅怀杨妃更是充满同情,方士招魂一段通过杨妃对玄宗情感的呼应而深化了这一爱情悲剧。诗人情感的位移又是与情感的纯化相伴随的,通过情感变异和选择性叙事等策略而加强了情感浓度。     

来自链霉菌属的阿魏酸酯酶的分离纯化、理化性质

通过盐析透析、离了层析、疏水层析,对链霉菌属发酵液中的阿魏酸酯酶（FAE）进行分离纯化。并进行酶学性质研究。得出的阿魏酸酯酶的纯化倍数为2．67,回收率为55．8％,酶分子约为30kDa。其最适反应pH约为6．0,最适温度约为50℃,金属离子Cu^2＋和Zn^2＋对阿魏酸酯酶酶活力均有明显的抑制作用,而Mg^2＋、Fe^2＋、Ca^2＋、Na^＋和Mn^2＋对酶的活性均有一定的促进作用。     

寄意于象的人性净化之路——细读《迟桂花》

学界对郁达夫《迟桂花》的评论有争议,本文把小说主人公＂莲＂看做一个内涵复杂的意象,借助叙事学理论细读这篇小说,还原其以女性形象塑造为支点、宣泄心灵压抑、寻求人性升华的叙事思路,指出小说叙事强调男性的反思和升华,女性仅仅承担了引发反思的中介功能,这既可以看作郁达夫的一贯的叙事策略,也体现了其小说创作的某种局限性。     

拟南芥和大蒜中超氧化物歧化酶提取方法的比较

用热变性法或磷酸缓冲液法从拟南芥植物中粗提取超氧化物歧化酶（SOD）,再用丙酮法或硫酸铵分级盐析法纯化SOD．比较发现,热变性法粗提取的SOD回收率较高,而2种纯化方法的差异却无统计学意义;同时,还比较了用同一种方法所提取的拟南芥和大蒜之间的SOD活性,大蒜的SOD活性高于拟南芥．