Approaches to fish DNA vaccine study

福建省自然科学基金(B0410022);; 福建省青年创新基金(2002J037

Probing the edge-related properties of atomically thin MoS2 at nanoscale

层状二维材料具有独特的物理化学性质，使其在光电器件、传感、能源和催化等领域得到了高度关注和广泛应用。二维材料在制备过程中不可避免引入结构缺陷，虽然这些缺陷尺度仅为数纳米甚至单原子，但是会极大地改变材料的结构和电子性质，从而影响其应用。化学化工学院任斌教授课题组在层状二维材料缺陷表征方面取得进展。该工作表明了TERS在原位、高空间分辨表征缺陷位的结构和电子性质方面具有独特的优势，可以进一步推广到其他二维材料，从而有效地指导缺陷设计和材料应用。 该工作通过校内外课题组紧密合作，在任斌教授、谭平恒研究员（中科院半导体研究所）和王翔博士共同指导下完成。实验部分主要由黄腾翔博士（第一作者，已毕业化学系博士生）完成，电子能带结构与光谱理论计算由谭平恒研究员课题组从鑫博士生（共同第一作者）完成，吴思思、林楷强、姚旭、何玉韩、吴江滨、包一凡、黄声超等参与了实验与讨论。【Abstract】Defects can induce drastic changes of the electronic properties of two-dimensional transition metal dichalcogenides and influence their applications. It is still a great challenge to characterize small defects and correlate their structures with properties. Here, we show that tipenhanced Raman spectroscopy (TERS) can obtain distinctly different Raman features of edge defects in atomically thin MoS2, which allows us to probe their unique electronic properties and identify defect types (e.g., armchair and zigzag edges) in ambient. We observed an edgeinduced Raman peak (396 cm−1) activated by the double resonance Raman scattering (DRRS) process and revealed electron–phonon interaction in edges. We further visualize the edge-induced band bending region by using this DRRS peak and electronic transition region using the electron density-sensitive Raman peak at 406 cm−1. The power of TERS demonstrated in MoS2 can also be extended to other 2D materials, which may guide the defect engineering for desired properties.The authors acknowledge the final supports from MOST of China (2016YFA0200601 and 2016YFA0301204), NSFC (21633005, 21790354, 21503181, 21711530704, 21621091, 11874350, 11474277, and 11434010), Natural Science Foundation of Fujian Province (2016J05046), and China Postdoctoral Science Foundation (2017M622062). 研究工作得到科技部、国家自然科学基金委员会、福建省自然科学基金和中国博士后基金资助

汉字认知心理研究对机器自动识别汉字的启示

几项认知心理学实验研究从不同角度一致证实,方决汉字的四个等分象限所含的字形特征信息量不同,在人类识别汉宇时作用也不一样,其中以左上象限最重要,右下象限的作用则要弱得多,本文结合部件的象限位置频率,讨论了这些结果对汉字机器识别的一些启示

Purification of serum IgM from large yellow croaker(Pseudosciaena crocea) and preparation of rabbit sera anti-IgM

分别用饱和硫酸铵二次盐析法和蛋白A亲和层析法对健康大黄鱼(Pseudosciaena crocea)血清中的免疫球蛋白(IgM)进行分离纯化,所得产物用SDS-PAGE进行检测。结果表明,蛋白A亲和层析法可以较好地分离到高纯度的大黄鱼血清IgM,产物的电泳胶中只有重链和轻链2个条带;饱和硫酸铵二次盐析法除了有这2个条带,还有很多杂带,而且蛋白A亲和层析法更为简便、快速,因此用蛋白A亲和层析法分离纯化IgM优于饱和硫酸铵二次盐析法;大黄鱼免疫球蛋白重链的分子量在76 kD左右;轻链分子量在28 kD左右。用纯化的大黄鱼IgM免疫实验兔,获得效价高达1∶40 960的兔抗鱼IgM血清。本实验所建立的蛋白A亲和层析法提取大黄鱼血清IgM可以方便、快捷地获得高纯度的产物,适合在实验室中纯化鱼类IgM。本研究所制备的兔抗大黄鱼IgM血清可为今后的相关研究工作打下基础。The serum IgM of healthy large yellow croaker(Pseudosciaena crocea) was purified by twice salt out of saturated(NH_(4))_(2)SO_(4) and protein A-sepharose affinity chromatography.The products were examined by SDS-PAGE electrophoresis.The results showed that the product of protein A-sepharose affinity chromatography had only two bands(heavy chain and light chain) in SDS-PAGE,while the product of twice salt out of saturated(NH_(4))_(2)SO_(4) had several other bands;moreover,using protein A-sepharose affinity chromatography to purify IgM was more simple,convenient and fast,so protein A-sepharose affinity chromatography was better than twice salt out of saturated(NH_(4))_(2)SO_(4) in terms of the purification of IgM;the molecular weight of heavy chain and light chain of Pseudosciaena crocea IgM were 76?kD and 28?kD respectively.Sera anti-IgM of Pseudosciaena crocea had been prepared by repeatedly immunized New Zealand rabbits with purified IgM,and the titers of anti-sera obtained up to 1∶40?960 examined by indirect ELISA.The results indicated that protein A-sepharose affinity chromatography was feasible in purification of IgM of Pseudosciaena crocea.The anti-sera obtained could be used in correlative studies in future.国家“863”计划项目(2002AA639600);; 福建省自然科学基金(B0410022);; 福建省青年创新基金(2002J037

Synchronized Minds

一般来说,神经科学家们每次只研究一个大脑。例如,他们会观察一个人在阅读特定单词或玩视频游戏时神经元的放电方式。然而,作为社会性动物,这些科学家们大多数的工作又是共同进行的一用头脑风暴建立假设,一起思考问题或优化实验设计。而且,研究人员们开始将这种&ldquo;协同工作&rdquo;的状态引入到他们研究大脑的方法中了。</p