Lectin-based electrophoretic analysis of the expression of the 35 kDa inter-alpha-trypsin inhibitor heavy chain H4 fragment in sera of patients with five different malignancies

A 35 kDa glycoprotein whose abundance was previously demonstrated to be enhanced in sera of patients with endometrial adenocarcinoma (n = 12), was isolated from pooled sera of three of the cancer patients using champedak galactose-binding lectin affinity chromatography in the present study. Subjecting it to 2-DE and MS/MS, the glycoprotein was identified as the O-glycosylated fragment of inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4). When compared to control sera (n = 17), expression of the 35 kDa ITIH4 cleavage fragment was demonstrated to be significantly enhanced in sera of patients with breast carcinoma (n = 10), epithelial ovarian carcinoma (n = 10), and germ cell ovarian carcinoma (n = 10) but not in patients with nasopharyngeal carcinoma (n = 13) and osteosarcoma (n = 7). The lectin-based electrophoretic bioanalytical method adopted in the present study may be used to assess the physiological relevance of ITIH4 fragmentation and its correlation with different malignancies, their stages and progression.     

C-H activation in bithiazole ring with thallium(III) ion

Two novel organometallic complex of 2,2′-dimethyl-4,4′-bithiazole (dm4bt) ligand (L) with formula [Tl(dm4bt)₂(NO₃)(H₂O)] (1) and [Tl(dm4bt)₂(NO₃)(DMSO)] (2) have been synthesized and structurally characterized by elemental analysis, FT-IR, ¹H NMR spectra and X-ray crystallography. These complexes also display the first transoid conformation in bithiazole ligands in which C-H bond activation in bithiazole ring is observed with Tl(III) ion.     

Adsorption kinetics at the solid/solution interface: statistical rate theory at initial times of adsorption and close to equilibrium

The kinetics of solute adsorption at the solid/solution interface has been studied by statistical rate theory (SRT) at two limiting conditions, one at initial times of adsorption and the other close to equilibrium. A new kinetic equation has been derived for initial times of adsorption on the basis of SRT. For the first time a theoretical interpretation based on SRT has been provided for the modified pseudo-first-order (MPFO) kinetic equation which was proposed empirically by Yang and Al-Duri. It has been shown that the MPFO kinetic equation can be derived from the SRT equation when the system is close to equilibrium. On the basis of numerically generated points ( t, q) by the SRT equation, it has been shown that we can apply the new equation for initial times of adsorption in a larger time range in comparison to the previous q vs radical t linear equation. Also by numerical analysis of the generated kinetic data points, it is shown that application of the MPFO equation for modeling of whole kinetic data causes a large error for the data at initial times of adsorption. The results of numerical analysis are in perfect agreement with our theoretical derivation of the MPFO kinetic equation from the SRT equation. Finally, the results of the present theoretical study were confirmed by analysis of an experimental system.     

甲醇制丙烯:最重要的催化剂及其性能

由于世界范围内原油缺乏和丙烯需求量增长,在甲醇转化制烃类的不同路线中,甲醇制丙烯(MTP)过程得到发展.本文讨论了催化剂结构对MTP工艺条件的影响以及分子筛酸性、晶粒尺寸、中孔特性和拓扑结构等因素对催化剂催化MTP反应活性和选择性的影响.     

Analysis of Ethylene/1‐Olefin Copolymers Made with Ziegler–Natta Catalysts by Deconvolution of Molecular Weight and Average Short Chain Branching Distributions

In this article a systematic method is proposed to deconvolute the time‐dependent molecular weight distributions (MWD) and average comonomer fraction profiles of ethylene/1‐olefin copolymers made with heterogeneous Ziegler–Natta catalysts. These distributions with a high‐temperature gel permeation chromatography equipped with an infrared detector at four different polymerization times have been measured and used this information to infer how the fractions of polymer made on each site type varied with polymerization time. The model estimates here the minimum number of active site types needed to describe these copolymers, the MWD of polymer populations made on each site type, and their average comonomer fractions. This method is useful to quantify the microstructure of olefin copolymers made with multiple site type catalysts using the least number of adjustable parameters.

     

Synthesis of 2-Mercaptonicotinic Acid-Capped CdSe Quantum Dots and its Application to Spectrofluorometric Determination of Cr(VI) in Water Samples

The CdSe quantum dots (QDs) capped with 2-mercaptonicotinic acid (H₂MN) were prepared through a controllable process at 80 °C. The prepared QDs were characterized by XRD, TEM, IR, UV–Vis and fluorescence (FL) techniques. It was found that the QDs were nearly mono-disperse with the diameters in the range of 8–10 nm. These QDs are capable to exhibit strong FL even in concentrated acidic media. They exhibit an enhanced fluorescence in the presence of Cr(VI), which was used for the determination of Cr(VI) in water samples. The linear range was found to be 1?×?10^?7–6.0?×?10^?6 M with the RSD and DL of 0.92 % and 5?×?10^?8 M, respectively. Except that Ca²⁺ and Fe³⁺ which can be eliminated through a simple precipitation process, the other co-existent ions present in natural water were not interfered. The recoveries obtained for the added amounts of Cr(VI) were in the range of 96.9–103.2 %, which denote on application of the method, satisfactorily.     

Dielectrophoretic manipulation and separation of microparticles using curved microelectrodes

This paper presents the development and experimental analysis of a dielectrophoresis (DEP) system, which is used for the manipulation and separation of microparticles in liquid flow. The system is composed of arrays of microelectrodes integrated to a microchannel. Novel curved microelectrodes are symmetrically placed with respect to the centre of the microchannel with a minimum gap of 40 μm. Computational fluid dynamics method is utilised to characterise the DEP field and predict the dynamics of particles. The performance of the system is assessed with microspheres of 1, 5 and 12 μm diameters. When a high‐frequency potential is applied to microelectrodes a spatially varying electric field is induced in the microchannel, which creates the DEP force. Negative‐DEP behaviour is observed with particles being repelled from the microelectrodes. The particles of different dimensions experience different DEP forces and thus settle to separate equilibrium zones across the microchannel. Experiments demonstrate the capability of the system as a field flow fraction tool for sorting microparticles according to their dimensions and dielectric properties.     

A novel and simple method for finding the heterogeneity of adsorbents on the basis of adsorption kinetic data

The heterogeneity of adsorbent was characterized by a novel and simple method that uses adsorption kinetic data from solution. On the basis of different simulated adsorption kinetic data for heterogeneous adsorbents with two different adsorption sites, it was found that there is a deviation from linearity in pseudo-second-order adsorption kinetic models. The patterns of obtained diagrams (t/qt vs t) shows five main classes of adsorption. On the basis of this novel and simple method it is possible to show that the surface of adsorbents is homogeneous or heterogeneous, and in the case of heterogeneous surfaces it is possible to find the differences between adsorption sites. For finding kinetic constants of adsorption on heterogeneous surfaces with two different sites, a new equation was presented and called the two-site pseudo-second-order (TS-PSO) model. Finally, some experimental kinetic data of adsorption were analyzed by the new method.     

Synthesizing UHMWPE Using Ziegler-Natta Catalyst System of MgCl2(ethoxide type)/ TiCl4/tri-isobutylaluminum

Summery: A Ziegler-Natta catalyst of MgCl₂ (ethoxide type)/TiCl₄ has been synthesized. In order to obtain ultra high molecular weight polyethylene (UHMWPE) tri-isobutylaluminum which is less active to chain transfer was used as cocatalyst. Slurry polymerization was carried out for the polymerization of ethylene while, dilute solution viscometry was performed for the viscosity average molecular weight (Mv) measurement. The effect of [Al]/[Ti] molar ratio, temperature, monomer pressure and polymerization time on the Mv and productivity of the catalyst have been investigated. The results showed increasing [Al]/[Ti] ratio in the range of 78–117, decreased the Mv of the obtained polymer from 7.8 × 10⁶ to 3.7 × 10⁶ however, further increase of the ratio, resulted in decreased of by much slower rate up to [Al]/[Ti] = 588. The higher pressure in the range of 1–7 bars showed the higher the Mv of the polymer obtained, while increasing temperature in the range of 50 to 90 °C decreased the Mv from 9.3 × 10⁶ to 3.7 × 10⁶. The Mv rapidly increase with polymerization time in the first 15 minutes of the reaction, this increase was slowly up to the end of the reaction (120 min). Increasing [Al]/[Ti] ratio raised productivity of the catalyst in the range studied. Rising reaction temperature from 50 to 75 °C increased the productivity of the catalyst however, further increase in the temperature up to the 90 °C decreased activity of the catalyst. Monomer pressure in the range 1 to 7 bars yields higher productivity of the catalyst. Also by varying polymerization conditions synthesizing of UHMWPE with Mv in the range of 3 × 10⁶ to 9 × 10⁶ was feasible.     

Laser ultrasonic receivers based on organic photorefractive polymer composites

We present two laser ultrasonic receivers based on organic photorefractive polymer composites with 2-[4-bis(2-methoxyethyl)aminobenzylidene]malononitrile (AODCST) or 2-dicyanomethylen-3-cyano-5,5-dimethyl-4-(4′-dihexylaminophenyl)-2,5-dihydrofuran nonlinear optical chromophores. Experimental results show sensitivities of the ultrasonic receivers of ~9.5 × 10^?8 nm (W/Hz)^0.5 for both composites, and a faster response time (~60 ms) for the AODCST-based laser ultrasonic receiver. We show that such LUS detectors are highly suitable for contactless thickness measurements of aluminum, steel sheets and defect detection with an accuracy of 100 μm.