Computational prediction of cleavage using proteasomal in vitro digestion and MHC I ligand data

Proteasomes are responsible for the production of the majority of cytotoxic T lymphocyte (CTL) epitopes. Hence, it is important to identify correctly which peptides will be generated by proteasomes from an unknown protein. However, the pool of proteasome cleavage data used in the prediction algorithms, whether from major histocompatibility complex (MHC) I ligand or in vitro digestion data, is not identical to in vivo proteasomal digestion products. Therefore, the accuracy and reliability of these models still need to be improved. In this paper, three types of proteasomal cleavage data, constitutive proteasome (cCP), immunoproteasome (iCP) in vitro cleavage, and MHC I ligand data, were used for training cleave-site predictive methods based on the kernel-function stabilized matrix method (KSMM). The predictive accuracies of the KSMM+pair coefficients were 75.0%, 72.3%, and 83.1% for cCP, iCP, and MHC I ligand data, respectively, which were comparable to the results from support vector machine (SVM). The three proteasomal cleavage methods were combined in turn with MHC I-peptide binding predictions to model MHC I-peptide processing and the presentation pathway. These integrations markedly improved MHC I peptide identification, increasing area under the receiver operator characteristics (ROC) curve (AUC) values from 0.82 to 0.91. The results suggested that both MHC I ligand and proteasomal in vitro degradation data can give an exact simulation of in vivo processed digestion. The information extracted from cCP and iCP in vitro cleavage data demonstrated that both cCP and iCP are selective in their usage of peptide bonds for cleavage.     

国内4种黑米的糊化特性和蒸煮品质对比

为选择适口性更好,蒸煮品质更加优良的黑米品种,采用质构仪、流变仪、差示扫描量热仪和快速黏度仪分析国内四种黑米(十月稻田、黑香米、天喔、周大黑)蒸煮60min后的糊化特性。结果表明:十月稻田表现出较高的硬度和糊化温度,较低的黏合力、咀嚼性和黏度,最耐糊化。黑香米的糊化温度稍低于十月稻田,但明显高于天喔和周大黑。天喔的黏性最大,黏度较周大黑低,比周大黑耐糊化。周大黑表现出较高的黏度和咀嚼性,较低的硬度和糊化温度,最易糊化,因此,是食用品质较为理想的黑米品种。     

Neuroprotective effects of flavonoids extracted from licorice on kainate-induced seizure in mice through their antioxidant properties

A relationship between status epilepticus (SE) and oxidative stress has recently begun to be recognized. To explore whether the flavonoids extracted from licorice (LFs) have any protective effect on kainate (KA)-induced seizure in mice, we treated mice with LFs before and after KA injection. In KA-treated mice, we found that superoxide dismutase (SOD) activity decreased immediately after the onset of seizure at 1 h and then increased at 6 h. It returned to baseline 1 d after seizure and then increased again at 3, 7, and 28 d, while malondialdehyde (MDA) content remained at a high level at 1 h, 6 h, 3 d, 7 d, and 28 d, indicating a more oxidized status related to the presence of more reactive oxygen species (ROS). Treatment with LFs before KA injection reversed the seizure-induced change in SOD activity and MDA content at 1 h, 6 h, 3 d, 7 d, and 28 d. Treatment with LFs after seizure decreased KA-induced SOD activity and MDA content at 7 and 28 d. Also, LF pre- and post-KA treatments decreased seizure-induced neuronal cell death. Subsequently, Morris water maze tests revealed that the escape latency was significantly decreased and the number of target quadrant crossings was markedly increased in the LF-treated groups. Thus, our data indicate that LFs have protective effects on seizure-induced neuronal cell death and cognitive impairment through their anti-oxidative effects.     

Tartary buckwheat database (TBD): an integrative platform for gene analysis of and biological information on Tartary buckwheat

Journal of Zhejiang University-SCIENCE B - 本研究首次构建了苦荞数据库,...     

Synthesis and paste properties of octenyl succinic anhydride modified early Indica rice starch

Octenyl succinic anhydride （OSA） modified early Indica rice starch was prepared in aqueous slurry systems using response surface methodology. The paste properties of the OSA starch were also investigated. Results indicated that the suitable parameters for the preparation of OSA starch from early Indica rice starch were as follows： reaction period 4 h, reaction temperature 33.4℃, pH of reaction system 8.4, concentration of starch slurry 36.8% （in proportion to water, w/w）, amount of OSA 3% （in proportion to starch, w/w）. The degree of substitution was 0.0188 and the reaction efficiency was 81.0%. The results of paste properties showed that with increased OSA modification, the starch derivatives had higher paste clarity, decreased retrogradation and better freeze-thaw stability.     

In vitro simulation studies of silica deposition induced by lignin from rice

To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra showed that the substance had the unique characteristics of pure lignin. The presence of silicon in the precipitation was revealed by TEM （transmission electron microscopy） with EDXA （energy dispersive X-ray analysis） device. It was found that in the borax solution where lignin precipitation occurred silica-lignin co-precipitation was produced but not in the DMSO solution where lignin was broken into its composition compounds and did not precipitate. This means that it is macromolecular lignin itself but not its compounds that could induce silica deposition in higher plants.     

余甘子抗氧化成分的提取与抗氧化活性研究

以乙醇为溶剂,超声波辅助提取余甘子果实的抗氧化成分并作用于花生油,对提取工艺及提取物对花生油的抗氧化活性进行了研究。正交实验的结果表明最佳提取工艺条件为:固液比为1:20、超声波处理60min、乙醇质量分数为50%;余甘子提取物能明显降低花生油过氧化值,常温下有良好的热稳定性与抗氧化性能。     

紫芋花色苷的抗氧化活性及其稳定性研究

采用铁离子还原法测定了紫芋中花色苷的总抗氧化能力,及防腐剂、金属离子和温度因素对其总抗氧化能力的影响.结果表明紫芋花色苷提取物的总抗氧化能力随加热时间延长而下降,温度越高,下降速度越快.防腐剂苯甲酸钠对紫芋花色苷提取物总抗氧化能力的影响不明显,四种金属离子（K＋、Mg2＋、Ca2＋、Zn2＋）对其总抗氧化能力有不同程度...     

黄酮类化合物抗HIV活性研究进展

综述了黄酮、二氢黄酮等化合物抗HIV活性研究进展，并对化合物的结构与抗HIV活性之间的构效关系进行了讨论，为该类化合物的进一步研究或开发提供参考。     

黄花油点草总黄酮积累动态分析研究

以陕西省紫柏山产黄花油点草为研究对象,采用亚硝酸钠-硝酸铝-氢氧化钠(NaNO_2-Al(NO_3)_3-NaOH)协同显色体系和紫外分光光度法,分析测定了黄花油点草在不同生长时期、不同部位及全草中总黄酮含量及其积累动态。芦丁标准品在3.177 6~79.44mg/mL范围内呈良好的线性关系,平均加样回收率100.66%,相对标准偏差(relative standard deviation,RSD)为2.17%(n=6)。研究结果表明,黄花油点草在不同生长时期、不同部位及其全草中总黄酮含量差异显著,其中9月份全草的总黄酮类(mg/g)最高,可达27.147mg/g,因此9月份应为黄花油点草的最佳采收期。本研究结果为黄花油点草入药部位及最佳采收期的确定提供了科学参考。     

当前我国高校体育教育改革的困境与消解

在高等教育改革力度不断加大的背景下,如何推进高校体育教育的改革,使之与时代的发展和未来社会对体育人才的需求有机结合是高校体育教育工作者面临的重大课题。本文围绕高校体育教育改革这一课题,指出了高校体育教育改革的目标,分析了当前我国高校体育教育的现状和问题,并有针对性的提出了推进高校体育教育改革的具体建议,以期对高校体育教育的改革和发展提供一定的参考。     

黄酮类化合物提取和分离方法研究进展

黄酮类化合物具有多种生理活性，从天然产物中提取和分离黄酮类化合物，引起了人们的广泛关注，其提取和分离方法也不断地改进和发展.文章主要综述了近几年来不同的提取和分离方法在黄酮类化合物中的应用进展.随着科技的进步，黄酮类化合物的提取和分离方法将更加快速、高效、完善.     

丝瓜皮黄酮的提取及抗氧化性分析

采用超声提取法从丝瓜皮中提取黄酮,通过正交试验确定最佳提取条件:超声时间20 min、料液比1:12、乙醇体积分数70%,在此条件下黄酮提取率为1.96%.通过测定丝瓜皮提取物对羟基自由基和超氧离子自由基的清除率,表明其具有较高的抗氧化能力.     

微波消解及ICP-AES同时测定土壤中多种元素含量

在盐碱土壤改良等项目进行过程中,需要进行大量的土壤采样和测试工作。为此,需要提供一种能够快速测定土壤中主要元素含量的测试方法。采用微波消解仪将土壤样品全消解,ICP-AES同时测定其中多种元素。对微波消解条件、酸体系等进行了分析和实验优化,确定了最佳条件。该方法样品消解完全、用酸量小、方便快速、测定结果满意。     

杏香兔耳风总黄酮含量的测定

目的：研究杏香兔耳风中总黄酮含量的测定方法；方法：采用紫外分光光度法，于510hm处测定；结果：线性范围为10．56—63．36？g／ml，r=0．9991，平均加样回收率为96．42％，RSD为1．41％；结论：该方法准确可靠，可用于杏香兔耳风药材的质量控制。     

题目：利用稻壳灰和人工砂的轻质油棕壳混凝土力学性能的提高

目的：探索稻壳灰和人工砂在轻质油棕壳混凝土中部分替换水泥和细骨料对混凝土力学性能的影响,期望得到力学性能较高的轻质混凝土。方法：1.将不同比例的稻壳灰（5%,10%,15%和20%）替换水泥和100%的人工砂或石粉替换沙子,研究它们对混凝土抗压强度的影响;2.研究不同替换比例的稻壳灰（0和15%）和人工砂（0,50%和100%）对混凝土力学性能的综合影响。结论：1.在15%的稻壳灰替换水泥和100%人工砂替换沙子的情况下,最大抗压强度为51.49 MPa;2.替换比例为15%稻壳灰和100%人工砂的组合表现出最好的力学性能,包括抗压强度、抗拉强度、抗弯强度和杨氏模量。     

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective  

To explore the effects of insulin-like growth factor-1 (IGF-1) on migration, proliferation and differentiation of mesenchymal stem cells (MSCs).     

嘧啶硫酮-姜黄素杂合体的合成及抗氧化活性研究

本文由姜黄素和硫脲两组分合成了一种新型的嘧啶硫酮化合物6-(4-羟基-3-甲氧基苯)-4-((1Z,3E)-羟基-4-(4-羟基-3-甲氧基苯)-1,3-丁二烯-1-基)嘧啶-2(1H)-硫酮(化合物3).利用核磁共振,红外光谱和质谱表征了化合物的结构.对化合物3进行DPPH自由基清除能力和高铁离子还原能力测试(FRAP),结果表明:化合物3具有一定的抗氧化活性.该新反应环境友好、无毒、无污染,操作简便、原子经济.     

急性运动对男性血浆总抗氧化状态和抗氧化酶活性的影响

为了探讨急性运动对总抗氧化状态(TAS)和抗氧化酶活性的影响,对健康未经训练的男性进行了3种不同功率的自行车测试,然后在每种运动前后随即取静脉血样,采用分光光度法测定TAS和酶活性.研究结果表明:与运动前相比,受试者在持续递增运动、剧烈运动直到力竭和亚极量运动30 min后的总抗氧化状态(TAS)、血浆过氧化氢酶活性(CAT)、谷胱甘肽还原酶(GR)、谷胱甘肽过氧化物酶(GPx)及超氧物歧化酶(SOD)的活性均有所提高,并且上升幅度达到显著水平(P<0.05).因此,在极量及亚极量运动后总抗氧化状态和血浆抗氧化酶活性增加.     

紫外分光光度法测定雪菊中总黄酮的含量

目的:测定雪菊中总黄酮含量。方法:将雪菊分别用60%乙醇加热回流提取三次,以芦丁为标准品,用紫外分光光度法测定雪菊中总黄酮的含量。结果:利用紫外分光光度法测得总黄酮含量为20.74%。结论:雪菊的总黄酮含量比其它菊花要高。