Adults scan own- and other-race faces differently

It is well established that individuals show an other-race effect (ORE) in face recognition: they recognize own-race faces better than other-race faces. The present study tested the hypothesis that individuals would also scan own- and other-race faces differently. We asked Chinese participants to remember Chinese and Caucasian faces and we tested their memory of the faces over five testing blocks. The participants' eye movements were recorded with the use of an eye tracker. The data were analyzed with an Area of Interest approach using the key AOIs of a face (eyes, nose, and mouth). Also, we used the iMap toolbox to analyze the raw data of participants' fixation on each pixel of the entire face. Results from both types of analyses strongly supported the hypothesis. When viewing target Chinese or Caucasian faces, Chinese participants spent a significantly greater proportion of fixation time on the eyes of other-race Caucasian faces than the eyes of own-race Chinese faces. In contrast, they spent a significantly greater proportion of fixation time on the nose and mouth of Chinese faces than the nose and mouth of Caucasian faces. This pattern of differential fixation, for own- and other-race eyes and nose in particular, was consistent even as participants became increasingly familiar with the target faces of both races. The results could not be explained by the perceptual salience of the Chinese nose or Caucasian eyes because these features were not differentially salient across the races. Our results are discussed in terms of the facial morphological differences between Chinese and Caucasian faces and the enculturation of mutual gaze norms in East Asian cultures.     

Towards genomic and proteomic studies of protein phosphorylation in plant-pathogen interactions

Phosphorylation is an effective method of post-translational protein modification but understanding its significance is hindered by its biological complexity. Many protein kinases and phosphatases have been identified that connect signal perception mechanisms to plant defence responses. Recent studies of mitogen-activated protein kinases, calcium-dependent protein kinases and other kinases and phosphatases have revealed some important mechanisms, but have also raised new questions. The regulation of any phosphorylation pathway is complex and dynamic. There are many protein kinases and phosphatases in the plant genome, which makes it hard to delineate the phosphorylation machinery fully. Genomics and proteomics have already identified new components and will continue to influence the study of phosphorylation profoundly in plant-pathogen interactions.     

A20 plays a critical role in the immunoregulatory function of mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess an immunoregulatory capacity and are a therapeutic target for many inflammation‐related diseases. However, the detailed mechanisms of MSC‐mediated immunosuppression remain unclear. In this study, we provide new information to partly explain the molecular mechanisms of immunoregulation by MSCs. Specifically, we found that A20 expression was induced in MSCs by inflammatory cytokines. Knockdown of A20 in MSCs resulted in increased proliferation and reduced adipogenesis, and partly reversed the suppressive effect of MSCs on T cell proliferation in vitro and inhibited tumour growth in vivo. Mechanistic studies indicated that knockdown of A20 in MSCs inhibited activation of the p38 mitogen‐activated protein kinase (MAPK) pathway, which potently promoted the production of tumour necrosis factor (TNF)‐α and inhibited the production of interleukin (IL)‐10. Collectively, these data reveal a crucial role of A20 in regulating the immunomodulatory activities of MSCs by controlling the expression of TNF‐α and IL‐10 in an inflammatory environment. These findings provide novel insights into the pathogenesis of various inflammatory‐associated diseases, and are a new reference for the future development of treatments for such afflictions.     

小鼠胚胎干细胞定向分化为神经干细胞过程中microRNA的变化

目的用生物芯片技术分析胚胎干细胞定向分化为神经干细胞过程中microRNA(miRNA)的表达变化,筛选调控的分化的miRNA,研究分化调控机制。方法胚胎干细胞在含LIF培养基中培养3d后,采用经典5步培养方法定向诱导向神经干细胞分化,采用nestin作为神经干细胞标记进行鉴定,送检胚胎干细胞及神经干细胞,提取总RNA以及小分子RNA,经荧光标记后与miRNA基因芯片杂交,获得胚胎干细胞诱导前后miRNA表达谱。结果1)胚胎干细胞在含LIF培养过程中保持未分化状态,Oct-4、碱性磷酸酶表达阳性;2)经典五步法诱导胚胎干细胞定向分化为神经干细胞,nestin阳性细胞为85%;3)通过基因微阵列分析,有90个miRNA的改变显著,其中68个表达上调,22个表达下调。结论miRNA可能对胚胎干细胞定向分化为神经干细胞过程起到关键作用。     

源自大黄鱼肠道柠檬酸杆菌的外切几丁质酶的特性分析（英文）北大核心CSCD

【目的】从饲喂富含几丁质饲料的大黄鱼肠道分离具有几丁质分解功能的菌株并分离鉴定新的几丁质酶。【方法】利用胶体几丁质平板分离饲喂杂鱼的大黄鱼肠道中的几丁质分解菌。对几丁质酶基因chi-X进行了克隆并在大肠杆菌中表达。对CHI-X的酶学性质进行了分析。【结果】从饲喂杂鱼的大黄鱼肠道内容物中分离出1株具有几丁质分解功能的费氏柠檬酸杆菌,其中的几丁质酶基因编码1个含493个氨基酸残基的蛋白,其中包含一个糖苷水解酶18家族催化域。CHI-X对胶体几丁质具有分解功能。最适p H和温度分别是4.0和60°C。CHI-X具有很强的pH稳定性,在pH 3.0–11.0的范围培育1 h仍保留90%左右的活性。Mn^(2+),Li^+和K^+可促进CHI-X酶活,Ag^+对CHI-X有抑制作用。CHI-X对蛋白酶和石斑鱼肠道内容物有较强的抗逆性。CHI-X可分解胶体几丁质为N-乙酰葡萄糖胺和N-乙酰葡萄糖胺二聚体,表明它是一个几丁质外切酶。最后,CHI-X和另一个几丁质酶Chi565表现出酶活性的加和效应。【结论】分离自肠道菌的CHI-X能很好适应海水鱼类的肠道环境,可以作为温水海水养殖鱼类的饲料添加剂使用。     

Exosomes derived from umbilical cord mesenchymal stem cells alleviate viral myocarditis through activating AMPK/mTOR‐mediated autophagy flux pathway

Human umbilical cord mesenchymal stem cell‐derived exosomes (hucMSC‐exosomes) have been implicated as a novel therapeutic approach for tissue injury repair and regeneration, but the effects of hucMSC‐exosomes on coxsackievirus B3 (CVB3)‐induced myocarditis remain unknown. The object of the present study is to investigate whether hucMSC‐exosomes have therapeutic effects on CVB3‐induced myocarditis (VMC). HucMSC‐exosomes were identified using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western blot. The purified hucMSC‐exosomes tagged with PKH26 were tail intravenously injected into VMC model mice in vivo and used to administrate CVB3‐infected human cardiomyocytes (HCMs) in vitro, respectively. The effects of hucMSC‐exosomes on myocardial pathology injury, proinflammatory cytokines and cardiac function were evaluated through haematoxylin and eosin (H&E) staining, quantitative polymerase chain reaction (qPCR) and Doppler echocardiography. The anti‐apoptosis role and potential mechanism of hucMSC‐exosomes were explored using TUNEL staining, flow cytometry, immunohistochemistry, Ad‐mRFP‐GFP‐LC3 transduction and Western blot. In vivo results showed that hucMSC‐exosomes (50 μg iv) significantly alleviated myocardium injury, shrank the production of proinflammatory cytokines and improved cardiac function. Moreover, in vitro data showed that hucMSC‐exosomes (50 μg/mL) inhibited the apoptosis of CVB3‐infected HCM through increasing pAMPK/AMPK ratio and up‐regulating autophagy proteins LC3II/I, BECLIN‐1 and anti‐apoptosis protein BCL‐2 as well as decreasing pmTOR/mTOR ratio, promoting the degradation of autophagy flux protein P62 and down‐regulating apoptosis protein BAX. In conclusion, hucMSC‐exosomes could alleviate CVB3‐induced myocarditis via activating AMPK/mTOR‐mediated autophagy flux pathway to attenuate cardiomyocyte apoptosis, which will be benefit for MSC‐exosome therapy of myocarditis in the future.     

高山被孢霉产花生四烯酸及其遗传改造的研究进展

花生四烯酸作为一种重要的多价不饱和脂肪酸,因其具有多种生理功能而被认为是潜在的食品添加剂和药物。近年来,利用高山被孢霉合成花生四烯酸已成为研究热点。前期相关研究主要集中在菌种选育及发酵调控方面。随着研究的不断深入,关于高山被孢霉合成花生四烯酸的代谢途径的研究取得了较大进展。以下简要概述前期工作进展,着重论述花生四烯酸合成途径的关键酶及其高山被孢霉的遗传改造的研究情况,包括生物合成花生四烯酸代谢途径、关键酶及其应用、高山被孢霉的遗传操作系统的构建以及遗传改造的应用,并对其研究前景进行了展望。     

Analysis of trehalose-6-phosphate synthase (TPS) gene family suggests the formation of TPS complexes in rice

Trehalose-6-phosphate (T6P), an intermediate in the trehalose biosynthesis pathway, is emerging as an important regulator of plant metabolism and development. T6P levels are potentially modulated by a group of trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) homologues. In this study, we have isolated 11 TPS genes encoding proteins with both TPS and TPP domains, from rice. Functional complement assays performed in yeast tps1 and tps2 mutants, revealed that only OsTPS1 encodes an active TPS enzyme and no OsTPS protein possesses TPP activity. By using a yeast two-hybrid analysis, a complicated interaction network occurred among OsTPS proteins, and the TPS domain might be essential for this interaction to occur. The interaction between OsTPS1 and OsTPS8 in vivo was confirmed by bimolecular fluorescence complementation and coimmunoprecipitation assays. Furthermore, our gel filtration assay showed that there may exist two forms of OsTPS1 (OsTPS1a and OsTPS1b) with different elution profiles in rice. OsTPS1b was particularly cofractionated with OsTPS5 and OsTPS8 in the 360 kDa complex, while OsTPS1a was predominantly incorporated into the complexes larger than 360 kDa. Collectively, these results suggest that OsTPS family members may form trehalose-6-phosphate synthase complexes and therefore potentially modify T6P levels to regulate plant development.     

中国淡水养殖池塘环境生态修复技术研究评述

传统的淡水池塘养殖所面临的环境问题日益严重,池塘环境生态修复技术的研究正蓬勃兴起.以“鱼-菜共生”模式为代表的原位修复技术和以循环水养殖模式为代表的异位修复技术是当前研究的重点.本文从水体富营养化的角度,以池塘氮循环为切入点,评述了这两种养殖池塘环境生态修复模式的优缺点,并对其涉及的面积配置关系进行了探讨.评述结果认为,只能通过“鱼-菜共生”模式降低池塘养殖的产排污系数,但通过推广该模式实现全国池塘养殖生态收支的平衡是困难的.虽然循环水养殖模式无法避免产生额外的经济成本和土地资源,但在局部地区,特别是富营养化严重的区域,其零排放的特点使其推广应用有一定的生态价值.     

华广虻肠道溶纤活性蛋白的纯化和性质(英文)

经过 75 %饱和度硫酸铵沉淀、SephadexG 75凝胶过滤层析、Lys Sepharose 4B亲和层析和电泳制备洗脱 ,从华广虻 (TabanusamaenusWalker)腹部组织匀浆液中分离纯化出分子量约为 6 7KD的溶纤活性蛋白TAFP。经纤维蛋白平板测定表明 ,TAFP不仅具有纤溶酶作用 ,还具有激活纤溶酶原的作用 ;通过三肽生色底物测定发现 ,TAFP能分解纤溶酶原激活剂的生色底物—ChromozymUK及S 2 2 88。还能水解胰蛋白酶专一底物Bz Phe Val Arg NA及CBZ Gly Pro Arg NA ,表明TAFP具有类胰蛋白酶活性 ,专一水解精氨酸形成的酰胺键 (或肽键 )。TAFP无胰凝乳蛋白酶活性