A Novel Electrochemical Aptasensor for Carcinoembryonic Antigen Detection Based on Target‐induced Bridge Assembly

The present study describes a novel electrochemical aptasensor for detection of carcinoembryonic antigen (CEA), a key cancer biomarker. The sensing strategy relied on the CEA‐induced bridge assembly, as a physical barrier, on the surface of gold electrode, resulting in a significant increase of the sensor sensitivity. Under optimal conditions, the aptasensing platform showed a wide linear range (3 pg/mL to 40 ng/mL) and a low detection limit (0.9 pg/mL). Some possible interfering materials were also assessed and the results indicated that the designed aptasensor had good specificity toward CEA. The quantitation of CEA in the spiked human serum samples confirmed the reliability and applicability of the electrochemical aptasensor. So, the developed sensing method has a potential application in the clinical diagnosis.     

ICP-AES测定Ni-Cr合金在人工唾液中析出的Ni离子

在模拟口腔环境下用人工唾液浸泡Ni-Cr桥,150h后采用ICP-AES测定Ni-Cr桥在人工唾液中的Ni离子析出量.镍在0.01-7.5μg/mL内有良好的线性关系,相关系数为0.9998;方法检出限为0.0059μg/mL;标准加入法测定镍的回收率为92.3%-99.8%.     

超导故障限流器的研究现状及其应用

超导故障限流器(Superconducting Fault Current Limiter,SFCL)是利用超导体的基本特性,有效限制电力系统故障短路电流,提高电网安全性和稳定性的一种新型电力设备。文中在综合大量文献的基础上,对超导故障限流器进行了一种较为系统的分类。基于该种分类,结合目前国内外的研究现状,就电阻型、磁屏蔽型、饱和铁芯电抗器型、桥路型SFCL的工作原理作了详细的分析介绍,还给出了它们在电力系统中的安装位置。最后,对超导故障限流器的研究中存在的问题及其发展趋势做了说明。     

Luminescent molecular hybrid system derived from 2-furancarboxylic acid and silylated monomer coordinated to rare earth ions

In this study, silica-based organic-inorganic hybrids were prepared by the sol-gel method. Tetraethoxysilane (abbreviated as TEOS) and a kind of monomer (abbreviated as FA-APES) derived from modified 2-furancarboxylic acid (abbreviated as FA) with (3-aminopropyl)triethoxysilane (abbreviated as APES) were used as the inorganic and organic fragments, respectively. Coordination reaction between lanthanides (europium and terbium ions) and CO group of the monomer happened simultaneously. And after days of aging process the resultant materials showed characteristic luminescence of lanthanides. The enhancement of luminescence can be seen by the comparison with simply doped lanthanide hybrid systems. And it can be explained by the coordination ability of the organic counterpart. IR, NMR, UV-vis absorption, low-temperature phosphorescence spectroscopy and fluorescence spectroscopy were applied to characterize and the above spectroscopic data revealed that the triplet state energy of organic ligand matches with the emissive energy level of lanthanides (especially of Tb³⁺).     

Syntheses and Crystal Structures of Two Coordination Polymers with Aromatic Dioxide as Bridge Ligands

Two coordination polymers, namely, two-dimensional complex 1 {[Cu(μ- L)1.5(ClO4)2(H2O)].(H2O)0.5}n (L = pyrazine-1,4-dioxide) and one-dimensional complex 2 [Co(μ-L)Br2(H2O)2]n, have been synthesized with pyrazine-1,4-dioxide as bridging ligands, and their crystal structures were determined by X-ray crystallography. Crystal data for complex 1: monoclinic system, space group C2/c, with a = 23.310(3), b = 12.2338(17), c = 10.6075(15) , β = 110.487(2)°, V = 2833.6(7) 3, Z = 8, C6H9Cl2CuN3O12.5, Mr = 457.60, Dc = 2.145 g/cm3, F(000) = 1832 and μ = 1.998 mm-1; and those for 2: monoclinic system, space group C2/c, with a = 11.012(3), b = 7.483(2), c = 11.451(3) , β = 101.654(4)°, V = 924.2(4) 3, Z = 4, C4H8Br2CoN2O4, Mr = 366.87, Dc = 2.637 g/cm3, F(000) = 700 and μ = 10.487 mm-1. 1 shows a two-dimensional sheet structure on the ac plane through the coordination of μ-L bridging ligands with Cu(II) ions, while 2 displays a zigzag one-dimensional chain along the c axis via the coordination of μ-L bridging ligand with Co(II) ions. Hydrogen bonds in 1 and 2 make the sheets (or chains) connect each other to form a three-dimensional structure.     

A new [Ni4] distorted cubane assembly on four solvent derived μ3-OMe corners: Solvent dependent formation and cleavage of exogenous bridges

A new Ni₄ distorted cubane complex [Ni₄(μ₃-OMe)₄Q₄(MeOH)₄] (1) (where Q⁻ is the anion of 8-quinolinol) is obtained from the reaction of NaQ with Ni(OAc)₂ · 4H₂O in refluxing MeOH via solvent derived μ₃-OMe assisted self-assembly of four nickel(II) centres. The periphery of [Ni₄(OMe)₄] cubane is covered by four Q⁻ and four MeOH molecules. This methanol specific reaction is not supported in solvent glycinol (Hgl; NH₂(CH₂)₂OH), an amine substituted ethanol, producing monomeric [NiQ₂(Hgl)₂] · 2H₂O (2 · 2H₂O) instead and is able to cleave 1 to yield 2 · 2H₂O. The cryomagnetic susceptibility data of powdered 1 can be modeled by a two J equation yielding J₁ = −1.8(1) cm⁻¹, J₂ = 3.9(1) cm⁻¹ and g = 2.24.     

Fused multifunctionalized bridge aromatic hydrocarbons from in situ-generated arynes and anthracene derivatives

This study presents a facile strategy for the formation of highly substituted butterfly 1,4-adducts/9,10-adducts via the Diels–Alder reaction of benzyne intermediates. The method achieves very good to excellent yields of the respective anthracene derivatives under mild conditions. This practical protocol is compatible with a variety of sensitive functional groups and provides access to difunctionalized bridge 1,4-adducts/9,10-adducts.     

A State-dependent Division Scheme for the Potential of Simple Fluids

Abstract

A new division scheme for the pair potential into long-range and short-range parts is presented, which takes account of the dependence on the density and makes possible the extraction of the bridge function B(r) in the core region. The calculation of the correlation functions is carried out with the hybridized mean spherical approximation (HMSA). As attested by the comparison with the simulation results, HMSA used with this potential separation is suitable to produce accurate bridge function and pair correlation function for the Lennard-Jones fluid.     

Penalized Regressions: The Bridge versus the Lasso

Abstract

Bridge regression, a special family of penalized regressions of a penalty function Σ|β_j|^γ with γ ≤ 1, considered. A general approach to solve for the bridge estimator is developed. A new algorithm for the lasso (γ = 1) is obtained by studying the structure of the bridge estimators. The shrinkage parameter γ and the tuning parameter λ are selected via generalized cross-validation (GCV). Comparison between the bridge model (γ ≤ 1) and several other shrinkage models, namely the ordinary least squares regression (λ = 0), the lasso (γ = 1) and ridge regression (γ = 2), is made through a simulation study. It is shown that the bridge regression performs well compared to the lasso and ridge regression. These methods are demonstrated through an analysis of a prostate cancer data. Some computational advantages and limitations are discussed.     

Characterization of 3-bridge links with infinitely many 3-bridge spheres

In an earlier paper, the author constructed an infinite family of 3-bridge links each of which admits infinitely many 3-bridge spheres up to isotopy. In this paper, we prove that if a prime, unsplittable link L in S³ admits infinitely many 3-bridge spheres up to isotopy then L belongs to the family.