An amplified single-walled carbon nanotube-mediated chemiluminescence turn-on sensing platform for ultrasensitive DNA detection

We have developed an amplified chemiluminescence turn-on sensing platform that relies on single-walled carbon nanotubes for ultrasensitive DNA detection. This new type of assay exhibits higher detection sensitivity over traditional biosensors by three orders of magnitude and high specificity for the target molecules.     

煤粉的增压富氧燃烧特性及煤灰矿物演变

为了更好地了解煤粉在增压富氧条件下的燃烧过程,利用加压热天平(PTGA)结合X射线衍射仪(XRD),研究了增压富氧燃烧条件下压力对煤粉燃烧特性及煤中矿物演变的影响。研究表明,随着压力的升高,煤粉常压时的非均相着火逐渐转变为均相着火,当压力升高到3 MPa开始向非均相着火过渡,并在5 MPa时完全转变成非均相着火。由于煤粉着火机理的转变,综合燃烧特性指数S随着压力的增加先升高后降低。不同的着火机理下,煤粉的燃烧温度也会有所差别。常压时非均相着火较高的燃烧温度使得反应生成了莫来石等矿物,而1 MPa时均相着火较低的燃烧温度则使得煤灰中出现了伊利石等矿物。压力继续升高,均相着火开始向非均相着火过渡,燃烧温度逐步升高,伊利石逐渐转变为莫来石。     

Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork

A rapid, sensitive chemiluminescent enzyme immunoassay (CLEIA) for ractopamine (RAC) based on a single-chain variable fragment (scFv)-alkaline phosphatase (AP) fusion protein was developed. The scFv gene was prepared by cloning the heavy- and light-chain variable region genes (V_H and V_L) from hybridoma cell line AC2, which secretes antibodies against RAC, and assembling V_H and V_L genes with a linker by means of splicing overlap extension polymerase chain reaction. The resulting scFv gene was inserted into the expression vector pLIP6/GN containing AP to produce the fusion protein in Escherichia coli strain BL21. The purified scFv-AP fusion protein was used to develop a direct competitive CLEIA (dcCLEIA) protocol for detection of RAC. The average concentration required for 50% inhibition of binding and the limit of detection of the assay were 0.25 ± 0.03 and 0.02 ± 0.004 ng mL⁻¹, respectively, and the linear response range extended from 0.05 to 1.45 ng mL⁻¹. The assay was 10 times as sensitive as the corresponding enzyme-linked immunosorbent assay based on the same fusion protein. Cross-reactivity studies showed that the fusion protein did not cross react with RAC analogs. DcCLEIA was used to analyze RAC spiked pork samples, and the validation was confirmed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS). The results showed a good correlation between the data of dc-CLEIA and HPLC–MS (R² > 0.99), indicating that the assay was an efficient analytical method for monitoring food safety.     

Syntheses,Crystal Structures and Physical Properties of Cd(II) and Mn(II) Complexes with <Emphasis Type="Italic">Trans</Emphasis>-1,2-di(4-pyrindyl)ethylene and <Emphasis Type="Italic">P</Emphasis>-(carboxyl-methyloxy)-benzenecarboxylic Acid

Abstract  

Two complexes [Cd₂(dpe)₃(H₂O)₈]·(dpe)·(hssal)₂·(H₂O)₂ 1, [Mn(dpe)₂(Hpcmb)₂·(H₂O)₂] 2, (dpe = trans-1,2-di(4-pyrindyl)ethylene; H₂hssal = sulphosalicylic acid; H₂pcmb = p-(carboxyl-methyloxy)-benzenecarboxylic acid) has been prepared, and was characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction. Structure indicates in complex 1 that Cd(II) is a distorted octahedral coordination geometry. The hssal²⁻ anions are localized between 2-D sheets {[Cd(dpe)₂(H₂O)₄]²⁺(dpe)}n and {{[Cd(dpe)₂(H₂O)₄]²⁺}n as count anions and bridge to further connect these 2-D sheets through hydrogen bond O–H···O to form 3-D structure. The complex 2 is a single molecule structure. In 2, Each Mn(II) atom is six-coordinated with a distorted octahedral coordination geometry. The single molecule units are extended into three-dimensional structure via π–π, hydrogen bonding interactions. The thermogravimetric behavior and luminescent property of complex 1 were investigated.     

基于运行数据的加热器主导因素建模

实现对回热加热器的实时在线性能监测,关键在于要建立高精度的回热加热器模型.本文采用主导因素建模法,在回热加热器稳态模型基础上新增特性参数,以提高模型在非稳态工况的适用性.5000组工况验证结果显示,模型改进后输出应达值与实际测量值的平均偏差较稳态模型减小了0.21％,标准差在抽汽侧和给水侧较稳态模型分别减少了19.5％...     

抗磁和顺磁性材料在磁场中弱磁力实验测量

对抗磁性材料和顺磁性材料在强磁场中的弱磁力进行测量.利用设计的实验装置,成功测得抗磁性石墨片和顺磁性材料铝片在永磁铁阵列表面受到的弱磁力.研究证明弱磁力的大小与磁场及磁场梯度乘积成正比.     

微孔板结合化学发光法快速测定覆盆子中总糖蛋白的抗氧化活性

在碱性条件下,覆盆子总糖蛋白对鲁米诺-过氢化氢、鲁米诺-邻苯三酚-氢氧化钠和鲁米诺-硫酸铜-过氧化氢化学发光体系具有明显的抑制作用。基于这一特点,本文将微孔板与化学发光法结合,在优化条件下,建立了覆盆子总糖蛋白清除H2O2、O2-和.OH自由基能力的快速检测方法,结果表明该方法具有样品用量少、操作简单、检测速度快等优点,适用于药物中有效成分的活性检测及筛选。     

一类p-Ginzburg-Landau型方程解的整体收敛性

作者研究了一类p-Ginzburg-Landau型方程解的整体收敛性.通过建立正则化方程解的梯度的一致估计,最终证明了解在C^α意义下收敛.     

Galois环上极大周期序列的平移等价

本文给出了Galois环上两个具有相同特征多项式的极大周期序列是否平移等价的—个判定方法,以及在两个序列平移等价的情况下,利用模p方幂提升技术,给出了—个计算它们的平移距离的方法.     

梯度泡沫铝的各向异性压溃力学行为

功能梯度泡沫金属因其密度连续变化,在轴向受压时可提供稳定增长的反馈载荷。然而当前研究多局限于其纵向压缩力学响应,考虑到实际应用中可能出现的横向冲击,基于低速冲击实验,考察梯度泡沫铝轴向和横向压缩力学响应的异同,并采用数字图像相关技术和数值模拟方法研究其宏细观压溃机制。结果表明:(1)在力学性能上,相比于纵向压缩加载的梯度泡沫铝,横向压缩加载下具有更高的抗压强度,而平台应力、致密化应变和能量吸收效果低于纵向压缩;(2)在失效变形模式上,纵向压缩变形模式为变形带渐进式压缩,而横向压缩变形模式的变形带则随机出现在试样的各个位置;(3)横向压缩下梯度泡沫铝致密化应变和比吸能的减小是由高孔隙率区的胞孔利用率降低导致的;(4)构建的弹性-塑性硬化-刚性模型能够较准确地描述梯度泡沫铝的纵向压缩力学行为。研究结果可为梯度泡沫金属在爆炸冲击结构防护工程中的设计提供理论参考。