Perceptual grouping without awareness: superiority of Kanizsa triangle in breaking interocular suppression

Much information could be processed unconsciously. However, there is no direct evidence on whether perceptual grouping could occur without awareness. To answer this question, we investigated whether a Kanizsa triangle (an example of perceptual grouping) is processed differently from stimuli with the same local components but are ungrouped or weakly grouped. Specifically, using a suppression time paradigm we tested whether a Kanizsa triangle would emerge from interocular continuous flash suppression sooner than control stimuli. Results show a significant advantage of the Kanizsa triangle: the Kanizsa triangle emerged from suppression noise significantly faster than the control stimulus with the local Pacmen randomly rotated (t(9)?=?-2.78, p?=?0.02); and also faster than the control stimulus with all Pacmen rotated 180° (t(11)?=?-3.20, p<0.01). Additional results demonstrated that the advantage of the grouped Kanizsa triangle could not be accounted for by the faster detection speed at the conscious level for the Kanizsa figures on a dynamic noise background. Our results indicate that certain properties supporting perceptual grouping could be processed in the absence of awareness.     

一种从多表达谱数据挖掘基因共表达团的新方法

随着近年来高通量基因表达谱数据的涌现,集成多个不同实验条件的表达谱数据,并挖掘在多数据源都保守的基因共表达团,成为预测基因功能或者调控关系的方法之一．但是,常用的方法通常仅简单地集成不同表达谱数据并推导保守基因共表达团,这样可能会导致结果中出现并非真正在多数据源保守的共表达团．提出一种结合最小哈希与局部敏感哈希的新方法,可以高效地寻找在多表达谱数据源中真正保守的基因共表达团．结果分析证明,相比过去的方法,现提出的方法可以获得更加功能相关和调控相关的基因共表达团．     

QTL mapping for adult-plant resistance to stripe rust in Italian common wheat cultivars Libellula and Strampelli

Italian common wheat cultivars Libellula and Strampelli, grown for over three decades in Gansu province of China, have shown effective resistance to stripe rust. To elucidate the genetic basis of the resistance, F₃ populations were developed from crosses between the two cultivars and susceptible Chinese wheat cultivar Huixianhong. The F₃ lines were evaluated for disease severity in Beijing, Gansu and Sichuan from 2005 to 2008. Joint- and single-environment analyses by composite interval mapping identified five quantitative trait loci (QTLs) in Libellula for reduced stripe rust severity, designated QYr.caas-2DS, QYr.caas-4BL, QYr.caas-5BL.1, QYr.caas-5BL.2 and QYr.caas-7DS, and explained 8.1–12.4, 3.6–5.1, 3.4–8.6, 2.6 and 14.6–35.0%, respectively, of the phenotypic variance across four environments. Six interactions between different pairs of QTLs explained 3.2–7.1% of the phenotypic variance. The QTLs QYr.caas-4BL, QYr.caas-5BL.1 and QYr.caas-7DS were also detected in Strampelli, explaining 4.5, 2.9–5.5 and 17.1–39.1% of phenotypic variance, respectively, across five environments. Three interactions between different pairs of QTLs accounted for 6.1–35.0% of the phenotypic variance. The QTL QYr.caas-7DS flanked by markers csLV34 and Xgwm295 showed the largest effect for resistance to stripe rust. Sequence analyses confirmed that the lines with the QYr.caas-7DS allele for resistance carried the resistance allele of the Yr18/Lr34 gene. Our results indicated that the adult-plant resistance gene Yr18 and several minor genes confer effective durable resistance to stripe rust in Libellula and Strampelli.     

载脂蛋白ApoE的原核表达以及与PrP蛋白间相互作用的初步研究

利用RT-PCR方法从人源细胞系SH-SY5Y cDNA中扩增出载脂蛋白ApoE基因,并在pET32a载体中表达融合蛋白His-ApoE,以纯化的融合蛋白免疫实验用兔获得特异性抗体,利用ELISA及免疫共沉淀方法对ApoE及PrP之间的相互作用进行研究.结果表明,SDS-PAGE显示表达的His-ApoE蛋白的相对分子量约为54 000,所制备的抗血清ELISA效价可达到1∶406 900,并能够有效地识别重组及动物组织中的内源性ApoE蛋白.ELISA和免疫共沉淀实验均显示,原核表达的ApoE可与全长的PrP蛋白（PrP23-231）在体外发生相互作用,其作用位点可能位于PrP蛋白的N端.这些结果为TSE经血传播的机制研究提供了新思路.     

稀有鮈鲫眼的形态发生研究

详细观察和描述了稀有鮈鲫眼发育的形态变化,并分别对视网膜发育早期神经层、色素上皮层的厚度及眼发育后期视网膜的总厚度进行了测量。结果表明:稀有鲫眼的发生始于神经胚时期形成的眼原基,与两栖、哺乳类动物不同,其眼原基是由间脑向左右伸出的对称外突实体;在尾芽期眼原基向腹侧弯曲、侧向伸长,随后开始内陷,在尾泡期形成视杯。眼原基外层与外胚层紧贴的部分将发育为视杯的内层、神经视网膜,而眼原基其余部分将分化为视杯的外层、视网膜色素层。在尾泡期之后,视网膜色素层停止有丝分裂开始形成色素颗粒,此时视网膜神经层开始分化。视网膜这两层结构在发育早期分化的有序进行可能与早期胚胎头部内空间以及附近的间充质细胞有关。从神经胚期到尾泡期,视网膜色素层厚度由42.3±0.8μm减小到4.8±0.4μm,视网膜神经层厚度从37.1±0.2μm增加到43.7±0.6μm,而从尾鳍期到孵出期视网膜总厚度从42.7±1.2μm逐渐增加到98.3±2.1μm。与所有脊椎动物一样,稀有鲫眼的视网膜分化也是按照由内向外的顺序进行,晶状体、角膜及其他结构在孵出时已基本发育完全。     

EB病毒BLLF-1基因转染小鼠T细胞淋巴瘤的研究

目的:研究EBV膜蛋白gp350/220的表达对共刺激分子ICOS的影响以及与T细胞淋巴瘤的关系。方法:繁殖饲养BLLF-1转基因昆明鼠以及正常昆明鼠,观察它们淋巴瘤发病率的差异。取发病的BLLF-1转基因昆明鼠脾脏淋巴细胞,用FITC标记的抗gp350/220单克隆抗体进行免疫荧光染色,检测gp350/220是否在该转基因昆明鼠淋巴细胞内表达及其表达部位。对发病转基因昆明鼠组织进行免疫组化染色,并与正常昆明鼠的进行对比分析。用RT-PCR方法检测转基因小鼠共刺激分子ICOS的表达变化。结果:BLLF-1转基因昆明鼠淋巴组织病理性改变与正常昆明鼠有显著差异,免疫荧光检测到该转基因小鼠淋巴细胞表达gp350/220于胞浆和胞膜上,病理学观察发现,发病小鼠淋巴结组织有反应性增生,脾脏淋巴瘤细胞浸润,免疫组化证明为T细胞淋巴瘤,转基因小鼠脾脏、肺脏及肿瘤中ICOS表达显著升高。结论:BLLF-1基因的表达,与该转基因小鼠发生T细胞淋巴瘤有关,并引起共刺激分子ICOS表达的变化,该转基因小鼠的建立,为我们进一步研究BLLF-1基因在T细胞淋巴瘤发病中的作用提供了良好的动物模型。     

Purification and characterization of a fibrinolytic enzyme of Bacillus subtilis DC33, isolated from Chinese traditional Douchi

Bacillus subtilis DC33 producing a novel fibrinolytic enzyme was isolated from Ba-bao Douchi, a traditional soybean-fermented food in China. The strong fibrin-specific enzyme subtilisin FS33 was purified to electrophoretic homogeneity using the combination of various chromatographic steps. The optimum temperature, pH value, and pI of subtilisin FS33 were 55°C, 8.0, and 8.7, respectively. The molecular weight was 30 kDa measured by SDS–PAGE under both reducing and non-reducing conditions. The enzyme showed a level of fibrinolytic activity that was about six times higher than that of subtilisin Carlsberg. The first 15 amino acid residues of N-terminal sequence of the enzyme were A-Q-S-V-P-Y-G-I-P-Q-I-K-A-P-A, which are different from that of other known fibrinolytic enzymes. The amidolytic activities of subtilisin FS33 were inhibited completely by 5 mM phenylmethanesulfonyl fluoride (PMSF) and 1 mM soybean trypsin inhibitor (SBTI), but 1,4-dithiothreitol (DTT), β-mercaptoethanol, and p-hydroxymercuribenzoate (PHMB) did not affect the enzyme activity; serine and tryptophan are thus essential in the active site of the enzyme. The highest affinity of subtilisin FS33 was towards N-Succ-Ala-Ala-Pro-Phe-pNA. Therefore, the enzyme was considered to be a subtilisin-like serine protease. The fibrinolytic enzyme had a high degrading activity for the Bβ-chains and Aα-chain of fibrin(ogen), and also acted on thrombotic and fibrinolytic factors of blood, such as plasminogen, urokinase, thrombin, and kallikrein. So subtilisin FS33 was able to degrade fibrin clots in two ways, i.e., (a) by forming active plasmin from plasminogen and (b) by direct fibrinolysis.     

The matrix protein CCN1 (CYR61) promotes proliferation, migration and tube formation of endothelial progenitor cells

Neovascularization and re-endothelialization relies on circulating endothelial progenitor cells (EPCs), but their recruitment and angiogenic roles are subjected to regulation by the vascular microenvironment, which remains largely unknown. The present study was designed to investigate the effects of mature ECs and matrix protein CCN1 on the properties of EPCs. In a coculture system, effects of ECs on proliferation, migration and participation in tube-like formation of EPCs were evaluated, and functional assays were employed to identify the exact role of CCN1 in EPCs vitality and function. We demonstrated that ECs, as an indispensable part of the cellular milieu, significantly promoted the proliferation, migration and tube formation activities of EPCs, and more importantly, CCN1 was potentially involved in such effects of ECs. Expression of CCN1 in EPCs was significantly increased by serum, VEGF, ECs-cocultivation and ECs conditioned medium. Moreover, Ad-CCN1-mediated overexpression of CCN1 directly enhanced migration and tube formation of EPCs, whereas silencing of endogenous CCN1 in EPCs inhibits cell functions. Furthermore, CCN1 induced the expressions of chemokines and growth factors, such as MCP-1 and VEGF, suggesting a complex interaction between those proangiogenic factors. Our data suggest that matrix protein CCN1 may play an important role in microenvironment-mediated biological properties of EPCs.     

Survival of Shigella in Sewage: II. Effect of Glycerol on Shigella flexneri and Shigella Bacteriophage1

Glycerol (30%) inhibited or delayed the adsorption of Shigella bacteriophage on its host organism, S. flexneri II; glycerol also inhibited or delayed the burst of phage, whether or not adsorption was carried out in the presence of glycerol. Studies of the mechanisms of these effects showed that viscosity and osmotic shock probably were not responsible for either phenomenon. The inhibition of adsorption, however, was proportional to the concentration of glycerol, and appeared to be a function of the hydroxyl groups on the glycerol molecule. The inhibition of burst seemed to be related to the osmotic pressure outside the bacterial cells.