68 research outputs found

    弗里斯对语料库驱动语言学的启示

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    美国语言学家查尔斯.弗里斯在语言研究科学性、实证性原则指导下,是第一个尝试语料库驱动研究的人。他的研究启示当代语料库驱动语言学应审慎对待传统词类划分,在对词类体系进行完善与全面否定之间取得平衡;反思新旧语言学理论守成与创新的关系;反思库容与技术的制约效应以及对创新的期盼,在技术可行与文本可用的张力中把握机遇与挑战;反思语料库语言学研究的数据定性归属及哲学立场

    Expression and Characterization of Fusion Protein tTF/SA as a Universal Effector for Targeting Blood Coagulati

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    制备凝血靶向通用效应因子tTF/SA融合蛋白,并鉴定其生物学活性。利用PCR技术构建tTF与链霉亲和素SA的融合基因,克隆至表达载体pET22b(+),在E.coliBL21(DE_3)中表达,镍亲和层析柱纯化tTF/SA融合蛋白。凝血实验和FⅩ活化实验鉴定融合蛋白中tTF的活性,ELISA鉴定融合蛋白中SA与生物素Biotin结合的活性。获得序列正确的tTF/SA/pET22b(+)重组子,融合基因在E.coliBL21(DE_3)中高效表达。纯化后的融合蛋白具有活化FⅩ、引起血液凝固的能力,且能与生物素结合。融合基因已成功在E.coliBL21(DE_3)中表达,tTF/SA融合蛋白具有TF和SA活性。融合蛋白tTF/SA可作为通用效应因子,与生物素化的肿瘤组织血管特异性载体联用,实现选择性诱发肿瘤组织血管栓塞的多点治疗。 【英文摘要】 To prepare a novel fusion protein (tTF/SA) as a universal effector for targeting therapy of blood coagulation and to analyze its biological activities. The fusion gene tTF/SA was constructed by PCR, then inserted into expression vector pET22 b (+),and expressed inE. coli BL21 (DE_3). The fusion protein was purified using Nickel-affinity chromatography column. The activities of tTF moiety of the fusion protein were analyzed by clotting assay and FX activation assay, and the binding activities of Streptavidin...福建省自然科学基金项目(No.C0410004); ;厦门大学科技创新项目(No.XDKJCX20053026).~

    Gene Expression and Activities Analysis of a New Fusion Protein (RGD)3/tTF

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    为了发展一种新型的融合蛋白(RGD)3/tTF用于肿瘤血管的选择性栓塞治疗,利用PCR技术重组(RGD)3/tTF融合基因,克隆于pET22b(+)载体,表达于E.coliBL21(DE3)。用镍柱纯化融合蛋白。凝血实验与FⅩ活化实验检测融合蛋白tTF组分的活性。间接ELISA分析(RGD)3/tTF与αvβ3的特异结合能力。pET22b(+)/(RGD)3/tTF重组质粒成功获得并表达于E.coliBL21(DE3)。纯化蛋白(RGD)3/tTF能有效诱发血液凝固,活化FⅩ。(RGD)3/tTF与αvβ3的特异结合能力比RGD/tTF提高了32%。新型融合蛋白(RGD)3/tTF已在E.coli系统成功表达,表达蛋白保持tTF的活性并显示比RGD/tTF更高的与αvβ3的结合能力。 【英文摘要】 To develop a new fusion protein (RGD)3/tTF for the therapy of the selective thrombosis of tumor blood vessels. The fused gene (RGD)3/tTF was reconstructed by PCR, was cloned into vector pET22 b(+),and expressed in E.coli BL21(DE_3). The fusion protein was purified through Nickel-affinity chromatography column. The tTF activity of the fusion protein was detected by clotting assay and FⅩ activation assay. The specific binding of (RGD)3/tTF to α_vβ_3 was analyzed by indirect ELISA. The recombinant plasmid pET2...福建省自然科学基金(No.C0410004);; 厦门大学科技创新基金资助(No.XDKJCX20053026)。~

    用于肿瘤血管靶向治疗的RGD/tTF融合蛋白的表达及活性鉴定

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    目的:制备用于肿瘤血管靶向治疗的重组RGD/tTF融合蛋白,并鉴定其生物学活性。方法:利用PCR技术构建RGD与tTF的融合基因,克隆至表达载体pET22b(+),在E.coliBL21(DE3)中表达,镍亲和层析柱纯化。凝血实验和FⅩ活化实验鉴定融合蛋白中tTF的活性,间接ELISA分析RGD活性。结果:获得序列正确的RGD/tTF/pET22b(+)重组子,融合蛋白在E.coliBL21(DE3)中高效表达。纯化后的融合蛋白具有活化FⅩ、引起血液凝固的功能,且能与αvβ3特异性结合。结论:成功构建RGD/tTF/pET22b(+)重组子,RGD/tTF融合蛋白具有TF活性且与αvβ3特异性结合,为进一步研究其体内特异性诱发肿瘤组织血管栓塞功能创造了条件

    MOCVD growth of high-reflectivity AlN/GaN distributed Bragg reflectors

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    利用金属有机物化学气相沉积(MOCVD)方法在蓝宝石c面衬底上制备出高反射率AlN/GaN分布布拉格反射镜(DBR)。利用分光光度计测量,在418 nm附近最大反射率达到99%。样品表面显微照片显示,有圆弧形缺陷和少量裂纹出现;在缺陷和裂纹以外的区域,DBR具有较为平坦的表面,其粗糙度在10μm×10μm面积上为3.3 nm左右。样品的截面扫描电镜(SEM)照片显示,DBR具有良好的周期性。对反射率和表面分析的结果表明,该样品达到了制备GaN基垂直腔面发射激光器(VCSEL)的要求。A high reflectivity AlN/GaN distributed Bragg reflector(DBR) is grown on c-plane sapphire substrate by metalorganic chemical vapor deposition(MOCVD).A peak reflectivity of 99% is observed around 418 nm by spectrophotometer.Compass-shape defects and a few cracks are observed on the surface.The surface root mean square(RMS) of roughness in the flat area is around 3.3 nm over a 10 μm×10 μm area.The cross-sectional scanning electron microscope(SEM) image reveals the good periodicity of DBR.Considering the peak reflectivity and surface morphology,the DBR can be used to fabricate GaN-based vertical cavity surface emitting laser(VCSEL).国家高技术研究“863”计划资助项目(2006AA03Z409

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

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    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

    散发型戊型肝炎与急性乙肝临床特征比较

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    目的比较散发型急性戊型肝炎与乙肝临床特征。方法分析戊肝和急性乙肝间年龄、性别、肝脏损伤、症状体征以及病程的差异。结果急性肝炎病例中,戊型肝炎最常见(28.0%),急性乙肝次之(9.2%);戊肝平均发病年龄为56.3±13.1岁,急性乙肝为43.0±12.5岁,平均发病年龄戊肝较急性乙肝大(t=4.4723,P<0.0001),均为男性多发;两者常见的临床症状和体征基本相当,但戊肝患者黄疸症状更多见(P<0.05);戊肝病程较急性乙肝长(t=3.7249,P=0.0003);通过年龄性别进行1:1匹配分析,戊肝比急性乙肝对肝脏的损伤程度严重(t=3.5978,P=0.0019)。结论戊肝多见于中老年,急性乙肝多见于中青年,均为男性多于女性。临床特征比较戊肝较急性乙肝更为严重

    Two I-h-symmetry-breaking C-60 isomers stabilized by chlorination

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    通讯作者地址: Xie, SY (通讯作者), Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 2. Xiamen Univ, Dept Chem, Coll Chem & Chem Engn, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] abiding surprise in fullerene science is that I-h-symmetric buckminsterfullerene C-60 (ref. 1) (I-h-C-60 or C-#1,812(60), the nomenclature specified by symmetry or by Fowler's spiral algorithm(2)) remains the sole C-60 species experimentally available. Setting it apart from the other 1,811 topological isomers (isobuckminsterfullerenes) is its exclusive conformity with the isolated-pentagon rule(3), which states that stable fullerenes have isolated pentagons. Although gas-phase existence of isobuckminsterfullerenes has long been suspected(4-7), synthetic efforts have yet to yield successful results. Here, we report the realization of two isobuckminsterfullerenes by means of chlorination of the respective C-2v-and C-s-symmetric C-60 cages. These chlorinated species, (C60Cl8)-C-#1,809(1) and (C60Cl12)-C-#1,804(2), were isolated in experimentally useful yields. Structural characterization by crystallography unambiguously established the unique pentagon-pentagon ring fusions. These distinct structural features are directly responsible for the regioselectivity observed in subsequent substitution of chlorines, and also render these unprecedented derivatives of C60 isomers important for resolving the long-standing puzzle of fullerene formation by the Stone-Wales transformation scheme(8-11).NNSF of China,20525103 ,20531050 ,20721001 , 20571062 ,20425312 973 Program 2007CB81530
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