Interaction of antigen and antibody on core-shell polymeric microspheres

Monodispersed microspheres with polystyrene as the core and poly(acrylamide-co-N-acryloxysuccinirnide) as the shell were synthesized by a two-step surfactant-free emulsion copolymerization.The core-shell morphology of the microspheres was shown by scanning electron microscopy and transmission electron microscopy.Rabbit immunoglobulin G (as antigen) was covalently coupled onto the microspheres by the reaction between succinimide-activated ester groups on the shell of the microspheres and amino groups of the antigen molecules.The size of particles was characterized by dynamic light scattering technique and was found to vary upon bioconjugation and interaction with proteins.The binding process was shown to be specific to goat anti-rabbit immunoglobulin G(as antibody) and reversible upon the addition of free antigen into the system.     

Preparation and hydrogen permeation properties of BaCe_(0.95)Nd_(0.05)O_(3-δ) membranes

Dense mixed proton and electron conducting membrane made of BaCe_(0.95)Nd_(0.05)O_(3-δ)(BCNd5)was prepared by pressing followed by sintering.X-ray diffraction(XRD)was used to characterize the phase structure of both the powder and the sintered membranes.The microstructure of the sintered membranes was studied by scanning electron microscopy(SEM).Hydrogen permeation through the BCNd5 membrane was studied using a high temperature permeator.The hydrogen permeation fluxes under wet conditions are higher than those under dry conditions,which is due to H~ hopping via surface OH groups.At 925℃,a hydrogen permeation flux of 0.02 mL/min cm~2 was obtained under wet condition,which recommends BCNd5 as a potential material for hydrogen-selective membranes.     

VINYLATION OF ARYL IODIDES CATALYZED BY〔POLY(STYRYL)BIPYRIDINE〕PALLADIUM(0)

[Poly(styryl)bipyridine]palladium(O),a polymer-bound hydrogrnation catalyst,was characterized by DRS,ESCA and electron microscopy.This material was used as cata-lyst for the vinylation of ary liodides.It was found that the catalytic activlty is comparableto that of the homogeneous catalyst and is not remarkably lowered on being used threetimes With this catalyst,a series of substituted stilbenes,cinnamic acids and methylcinnamates was prepared in high yields.     

γ-Fe_2O_3固载Pd-靛红席夫碱配合物作为磁性可回收催化剂用于Heck和Suzuki交叉偶联反应(英文)

A Pd-isatin Schiff base complex immobilized on γ-Fe2O3(Pd-isatin Schiff base-γ-Fe2O3) was synthe-sized and characterized by Fourier transform infrared, scanning electron microscopy, high resolu-tion transmission electron microscopy, X-ray diffraction, thermogravimetric gravimetric analysis,inductively-coupled plasma, X-ray photoelectron spectroscopy, and elemental analysis. It was used as a magnetically reusable Pd catalyst for the Heck and Suzuki cross-coupling reactions.     

Preparation and Characterization of Dichlorocarbene Modified Multiple-walled Carbon Nanotubes

Multiple-walled carbon nanotubes were functionalized by cycloaddition of dichlorocarbene.The chemical modification was performed by using chloroform and sodium hydroxide.Various phase transfer catalysts were used to increase the efficiency of the reaction.Benzyltriethylammonium chloride used as phase transfer catalyst could highly enhance the effect of functionalization.Elemental analysis was used to evaluate the degree of functionalization.Characterization was performed using scanning electron microscopy(SEM)and transmission electron microscopy(TEM).Fourier transform infrared spectroscopy(FTIR)and energy-dispersive X-ray spectroscopy(EDS)were used to confirm the resulting material.     

Preparation and characterization of gadolinium hydroxide single-crystalline nanorods by a hydrothermal process

The Gd(OH)3 nanorods with diameters of ca.40-60 nm and lengths of more than 400-550 nm have been prepared by a novelhydrothermal technique.The structural features and chemical composition of the nanorods were investigated by X-ray diffraction(XRD),transmission electron microscopy(TEM),and field emission scanning electron microscope(FESEM),selected areaelectron diffraction(SAED),and high resolution transmission electron microscopy(HRTEM).The possible mechanism for theformation of Gd(OH)3 nanorods was proposed.     

MODIFICATION OF MULTI-WALLED CARBON NANOTUBES WITH POLY(NITRILOETHYLENENITRILOVINYLENE) “GRAFTING TO” THE SURFACE

A mild and facile way was used to prepare poly(nitriloethylenenitrilovinylene)-grafted multi-walled carbon nanotubes(MWCNTs-g-PNENV)nanocomposites via the"grafting to"method.The MWCNTs-g-PNENV nanocomposites are well dispersible in polar solvents such as water,tetrahydrofuran and ethanol.Chemical structure of the resulting product was characterized by Fourier transform infrared(FTIR)spectroscopy,transmission electron microscopy(TEM)and thermal gravimetric analysis(TGA).FTIR showed that the"grafting to"pr...     

Preparation of a novel,efficient, and recyclable magnetic catalyst,γ-Fe_2O_3@HAp-Ag nanoparticles,and a solvent- and halogen-free protocol for the synthesis of coumarin derivatives

In this protocol, Ag supported on the hydroxyapatite-core–shell magnetic γ-Fe_2O_3nanoparticles(γFe_2O_3@HAp-Ag NPs) as a novel, efficient, and magnetically recyclable catalyst is synthesized, and characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), and vibrating sample magnetometry(VSM). The use of the catalyst is described in the synthesis of coumarin derivatives by the Pechmann condensation of various phenols with β-ketoesters under solvent- and halogen-free conditions at 80℃.This novel and inexpensive method offers advantages, such as recyclability simple experimental protocol, short reaction time, minimal work-up procedure, and excellent yields of products, together with desirable, eco-friendly, green aspects by avoiding toxic elements and solvents, and ease of recovery from the reaction mixture using an external magnet.     

Preparation and recognition performance of ratio-fluorescent probe based on sulfadiazine imprinted polymersEI北大核心CSCD

A novel ratio-fluorescent probe based on molecular imprinting polymer ( MIP) for the detection of sulfadiazine was prepared by using nitrogen-doped carbon quantum dots (N-CQDs) as the fluorescence response signal, silica-embedded cadmium telluride quantum dots ( CdTe QDs) as the fluorescence reference signal, sulfadiazine ( SDZ) as template molecule, acrylamide as functional monomer, N, N-methyl bisacrylamide as crosslinking agent and 2,2-Azobisisobutyronitrile as initiator. The results showed that the probe has a core-shell structure and fluorescence sensitive to SDZ, by the characterization of scanning electron microscopy, transmission electron microscopy, and fluorescence spectrophotometer. Under the wavelength of 360 nm, the ratio-fluorescent signal of probe showed a linear response with SDZ concentration in the range of 0-100 μmol / L with the detection limit of 11 nmol / L. Also, the ratio-fluorescent probe was applied to the detection of SDZ with a recovery of 92. 0%-95. 1% and relative standard deviation (RSD) of 3. 6% in real water samples. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Synthesis and Characterization of a Novel Liquid Crystalline Chitin — Quaternary Ammonium Chitosan Salt

N-Butyl chitosan(NBCS) derivatives were prepared by introducing butyl groups into the amine groups of chitosan via Schiff base intermediates. The quaternization of NBCS was carried out by using ethyl iodide to produce water-soluble cationic polyelectrolytes. The degree of the substitution of the products was measured by means of the electron spectroscopy for a successful chemical analysis. The quaternary ammonium chitosan salt(QACS) was proved to be a novel cholesteric liquid crystalline chitin, by means of the polarized optical microscopy and the circular dichroism spectropolarimetry. The critical mass fraction of the QACS/formic acid solution forming a lyotropic liquid crystal phase was 50%, which was almost the same as that of the NBCS/formic acid solution, but much hiuher than that of the chitosan in the same solvent.     

Gelation capability of cysteine-modified cyclo(L-Lys-L-Lys)s dominated by Fmoc and Trt protecting groups

A series of symmetrical peptidomimetics(3–8) based on cysteine-modified cyclo(L-Lys-L-Lys)s were synthesized, and their gelation capability in organic solvents was dominated by fluorenylmethyloxycarbonyl(Fmoc) and triphenylmethyl(Trt) protecting groups and the exchange of thiol-to-disulfide as well. The peptidomimetics holding Trt(3 and 4) showed no gel performance, while the Fmoc groups promoted 5 and 6 to give rise to thermo-reversible organogels in a number of organic solvents. The self-assembled fibrillar networks were distinctly evidenced in the organogels by transmission electron microscopy(TEM) and scanning electron microscopy(SEM) observations. Fourier transform infrared spectroscopy(FT-IR) and fluorescence analyses revealed that the hydrogen bonding and ?-? stacking play as major driving forces for the self-assembly of these organogelators. A ?-turn secondary structure was deduced for the organogel of 6 by virtue of X-ray diffraction, FT-IR and circular dichroism(CD) measurements, and an interdigitated bilayer structure was also presented.     

离子液体中电沉积制备钴纳米线阵列

Porous anodic alumina (PAA) was used as a template to prepare Co nanowires array from 1-ethyl-3-methylimidazolium chloride ionic liquid by direct current method. The surface morphology of porous anodic alumina template was observed by field emission-scanning tunneling microscopy (FE-SEM) before and after the electrodeposition of Co nanowires. The electrodeposition of Co nanowires was characterized by transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). TEM results indicate that the Co nanowire surface is coarse and porous when aqueous solution was used as electrolyte， and the Co nanowire deposited from the ionic liquid is uniform and smooth. XRD results show that the electrodeposition of Co is a mixture of crystal and microcrystal phase.     

磷酸锆铁催化无溶剂条件下醇和苯酚乙酰化(英文)

Iron zirconium phosphate(ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various sub-strates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3  when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environ-mentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.     

Solvothermal Synthesis and Characterization of HgTe Nanoplatelets Using Mercury（I） Source

Mercury telluride （HgTe） nanoplatelets were obtained via a facile solvothermal reaction of mercury（I） chloride and tellurium powder in ethylenediamine （en）. Mercury（I） was first applied as the mercury sources to prepare nanocrystal HgTe; moreover, the proposed mechanism for the fabrication of the sample was discussed in detail. The HgTe nanoplatelets were characterized by powder X-ray diffraction （PXRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM） and Fourier transform infrared spectroscopy （FT-IR）. The absence of IR absorption may render the title nanocrystal useful as an IR transparent material in the region.     

微波辅助溶胶-凝胶法合成MgO纳米粒子及其催化合成Hantzsch1,4-二氢吡啶性能(英文)

A microwave-assisted sol-gel method was employed for the preparetion of nano-sized MgO particles using Mg(NO 3)2·6H2O as precursor and deionized water as solvent.The sample calcined at 500℃ had a high specific surface area of 243.2m2/g and particles sizes from 9.5to10.5nm.For comparison,MgO nanoparticles were also synthesized without microwave irradiation.X-ray diffraction (XRD) characterization showed the formation of smaller particles after microwave irradiation.The structure and morphology of the MgO particles were analyzed by N2 adsorption-desorption,XRD,scanning electron microscopy,and transmission electron microscopy.Their catalytic behavior was studied with the one-pot synthesis of Hantzsch1,4-dihydropyridines from the reaction of aromatic aldehydes,ethyl acetoacetate,and ammonium acetate.The MgO nanoparticles have high catalytic activity and gave the desired products in good to high yields.The catalyst can be easily recovered by filtration and was used at least three times with only a slight reduction in its catalytic activity.     

热分解双(2-氨基烟酸)锌(Ⅱ)制备的介孔微砖ZnO纳米颗粒的光催化活性(英文)

Hollow microblocks of [Zn(anic)_2], as a novel coordination compound, were synthesized using 2-aminonicotinic acid(Hanic) and zinc(Ⅱ) nitrate tetrahydrate. The chemical composition of the zinc complex, ZnC_(12)H_(10)N_4O_4, was determined by Fourier transform infrared(FTIR) spectroscopy and elemental analysis. The synthesized zinc complex was used as a precursor to produce ZnO nanostructures by calcination at 550 °C for 4 h. Morphological studies by scanning electron microscopy and transmission electron microscopy revealed the formation of porous microbricks of ZnO nanoparticles. N_2 adsorption-desorption analysis showed that the obtained ZnO microbricks possess a mesoporous structure with a surface area of 8.13 m~2/g and a pore size of 22.6 nm. The X-ray diffraction pattern of the final product proved the formation of a pure ZnO composition with a hexagonal structure. Moreover, FTIR analyses showed that the 2-aminonicotinic acid ligand peaks were absent after the calcination step. Diffuse reflectance spectroscopy was used to determine the band gap energy of the produced ZnO and it was about 3.19 eV. To investigate the photocatalytic activity of the porous ZnO nanostructure, a series of photocatalytic tests were carried out to remove Congo red, as a representative toxic azo dye, from aqueous solution. The results show that the product can be used as an efficient photocatalyst for waste water treatment with high degradation efficiency.     

多壁碳纳米管包裹Fe3C单晶纳米线的初步研究

Multi-walled carbon nanotubes were fabricated by chemical vapor deposition with acetylene as carbon source and titanate modified palygorskite as catalyst at high temperature. A part of as-grown nanotubes was partially filled with foreign material in the shape of nanowire by transmission electron microscopy (TEM) observations. The en-capsulated nanowires was single crystalline iron carbide upon selected area electron diffraction(SAED)patterns and X-ray energy dispersive spectrum (EDS) results. Thermal gravimetric analyses (TGA) on the as-grown samples indicated that the yield of carbon nanotubes was largest at 750℃ and the content of amorphous carbon decreased with increasing temperature. Furthermore， the growth mechanism was discussed on the experimental results in the paper.     

Preparation and Magnetic Property of La_(0.7)Sr_(0.3)MnO_3 Nanorod by Combination Sol-Gel with Molten Salt

La0.7Sr0.3MnO3(LSMO) nanorods were synthesized by a method combining sol-gel with molten salts at 950 °C for 10 h, which employed KCl+NaCl(mass ratio 4:1) as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and vibrating sample magnetometer(VSM) measurements. It was found that the obtained perovskite manganite LSMO was a uniform nanorod with a d...     

Fabrication of hollow silica microspheres utilizing a hydrothermal approach

Hollow silica microspheres(HSMSs) have been successfully fabricated via a facile hydrothermal route using D-glucose as the sacrificial template and sodium silicate powder as the silica precursor.The resulting silica hollow particles were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and infrared spectroscopy(IR).The surface area was determined using the BET method.SEM and TEM images exhibited micro-sized silica hollow particles with a size of ~1.5μm.     

Crystal Structure,One-and Two-photon Excited Fluorescence and Bioimaging of a D-π-A Structural Triphenylamine Derivative

An electron donor-π-bridge-electron acceptor(D-π-A) optical functional organic compound comprising a triphenylamine moiety as the electron donor and pyridine moiety as the electron acceptor was synthesized. The structure of the compound was solved by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, with a = 9.753(5), b = 8.815(5), c = 25.554(5) ?, β = 96.315(5)°, V = 2184(2) ?~3, Z = 2, D_c = 1.136 g/m~3, F(000) = 792, Μr = 746.92, μ = 0.069 mm~(-1), the final R = 0.0658 and wR = 0.1730 for 6790 observed reflections with I 2(I). Study of nonlinear optical properties shows that the compound exhibits excellent two-photon excited fluorescence with the two-photon absorption cross-section value of 116 GM. The structure-property relationship was researched in detail through X-ray crystallography and quantum chemical calculation. Result of living cell imaging experiment shows its potential in fluorescence microscopy bioimaging.