Enzyme biosensors based on ion-selective field-effect transistors

The key theoretical principles of the work on ion-selective field-effect transistor connected with their application in bioanalytical practice, some specifics of modern microtechnologies for their creation, and measurement schemes with set-ups are discussed. The achievements in the creation of enzyme biosensors based on ion-selective field-effect transistors and prospects for their application are described in detail.     

Comment on the positron reactions with pseudo-halides in water

Comments are made on the data reported by Mogensen, Pedersen and Andersen on positron reactions with pseudo-halide ions in water and on their interpretation. Although some of our previous experimental curves are in agreement with theirs, there is a major discrepancy with some of their semi-empirical data, pointing to internal inconsistencies in their results. The possibility of another interpretation of the data is suggested.     

Formation,Degradation, and Applications of Polyperoxides

Abstract

Even though the history and chemistry of polyperoxides is long known, they need further investigation with respect to their reactivity and applications to understand their real potential. For instance, unlike in acid polyperoxides, only scanty reports have been made on the initiating behavior of vinyl polyperoxides inspite of their well-known synthetic chemistry. Hence, it appears that there remains a significant gap between the discovery of vinyl polyperoxides and in our understanding of their role as radical initiator. This article is intended to fill this gap by ventilating the significant developments on polyperoxides, which are finding an increasing role both in fundamental and applied polymer science. However, the scope of this article is restricted to their synthetic methodologies, degradation and applications as initiators/curatives. The kinetics and mechanism of their formation and degradation have been dealt with briefly. The characteristic and notable features of the kinetics and mechanism on polyperoxide initiated polymerizations are also discussed, and some of their applications are highlighted. Emphasis has also been laid on the futuristic research trends on polyperoxides.     

磁性铁氧化物纳米粒子制备及其体内应用研究

磁性铁氧化物纳米粒子由于其生物相容性和低毒性而广泛的应用于生物医学领域。本文总结了近年来制备各种磁性铁氧化物纳米粒子的方法,比较了它们在粒径、结晶度以及制备条件等方面的优缺点,概括了对其进行表面修饰改性材料的种类,阐述近年来磁性铁氧化物纳米粒子在体内应用中药物运输、磁共振成像、磁热疗方面的进展,并指出当前应用中的主要方向和亟待解决的问题。     

Refractometry of dian and aliphatic epoxy oligomers

The refractometric characteristics of dian and aliphatic epoxy oligomers and their mixtures in a wide range of concentrations and temperatures have been investigated. It has been shown that the temperature dependences of the refractive indexes of the oligomers and their mixtures are straight lines. Upon mixing the oligomers, their volume remains unchanged. The molar refractions of individual oligomers and their mixtures are determined from experimental values of refractive indexes and densities and on the basis of calculations of atomic and group contributions using the concentrations of terminal fragments and the ratio of components. The effect of terminal fragments of the oligomers on the refractive index, density, and molar refraction was taken into account using the reduced molecular mass values. Methods for estimating the molecular mass of linear epoxy oligomers on the basis of their refractive indexes are suggested.     

Laser-ultramicroscopic method of determining suspended particles in high-purity liquids

Two main types of impurities in high-purity liquids have been determined. One consists of suspended particles of sub-mum size, and optical counters are the most suitable for their determination. Their main characteristics are given. The errors of suspended particle determination are discussed. The data on particles dispersion composition and concentration in some high purity liquids as well as on their nature are given.     

树脂对化工废水中有毒有机化合物的吸附作用机理与技术研究

超高交联吸附树脂对多种芳香有机化合物较高的吸附容量主要源于其密集的微孔和双峰孔分布.对大孔吸附树脂及超高交联吸附树脂采用不同极性功能基团进行化学修饰可以制得系列离子交换与吸附双重功能吸附树脂,该类树脂对亲水性有机污染物同时具有疏水、静电、络合等多重作用.丙烯酸酯类吸附树脂在吸附芳香磺酸盐时,树脂的骨架和功能基团对吸附过程都有重要的贡献.     

THE GENETIC TYPES OF BAUXITE DEPOSITS IN CHINA

The genetic type classification of the bauxite deposits in China was oversimplified in the past and the author tries to make a relatively detailed division based on their practical conditions. First, the occurrences of bauxite deposits are divided into platform and geosyncline terrains according to their geotectonic setting. Then, the lateritic, accumulated, sedimentary, solution precipitated diagenetitc-epigenetic, regional metamorphic categories and two metacategories are established based on their main metallogenetic processes. Finally 21 types and 9 metatypes are set up according to their formation features (including genesis, sedimentary environment or major mineral features), of which several types are newly established. The classification is quite different from that of the world's bauxite deposits, the metacategories and metarypes refer to the deposits o only scientific significance at present.     

CO and NO in medicine

The occurrence, role and consequences of CO and NO in biological systems are reviewed. This includes their syntheses by heme oxygenases and NO synthases, their biological targets and the physiological effects of their signals. The use of CO and NO gases in medicine are discussed and methods of delivery are illustrated with particular emphasis on the therapeutic properties of compounds that generate controlled amounts of NO and CO in vivo.     

Poly(ionic liquid)s: Synthesis,properties, and application

The overview of the published data on a new class of polyelectrolytes—the so-called polymeric ionic liquids or poly(ionic liquid)s—is presented. The peculiarities of their synthesis and the factors affecting their molar masses, solubility, ionic conductivity, electrochemical stability, and thermal properties are discussed. The mainstreams in the application of poly(ionic liquid)s and materials formed on their basis are illustrated by specific examples.     

Organic pollutants adsorbed on microplastics: Analytical methodologies and occurrence in oceans

The massive use of plastics in several products has generated microplastic debris worldwide. Besides their negative effect on marine organisms by ingestion, microplastics are a contamination vector due to their capacity to transport organic pollutants around our planet. To evaluate the magnitude of this issue, it is necessary to know what kinds of contaminants are adsorbed on microplastics, as well as their concentrations. In order to assess the adsorption and desorption of pollutants from microplastics, effective and reliable extraction procedures are required. In this overview, literature reports, in which extraction, separation and determination methods have been applied to analyse the organic pollutants adsorbed on microplastics, are revised and discussed. Furthermore, the worldwide occurrence of organic compounds found on microplastics in oceans is reviewed and the results obtained from different geographical areas and their global distribution trends are compared. Priority organic pollutants, such as polycyclic aromatic hydrocarbons, hexachlorocyclohexanes, polychlorinated benzenes, perfluoroalkyl substances or bisphenol analogues, have been widely found on microplastic samples. Future research that focuses on different kinds of emerging pollutants is required.     

苯并咪唑及其衍生物合成与应用研究进展

苯并咪唑及其衍生物具有良好的生物活性, 而且是一种重要的药物中间体. 由于它们具有良好的生物活性和反应活性, 一直都是研究的热点. 从该类化合物的合成与应用两个方面综述了近年来该领域的重要研究成果.     

Amorphous perfluorinated membrane materials: Structure,properties and application

The structure and properties of glassy amorphous perfluorinated polymers are considered with an emphasis of their use as membrane material. The results of the study of free volume in these polymers and simulation of their nanostructure are discussed. The perfluorinated polymers are featured by unusual thermodynamic properties, so the influence of these properties on the parameters of the membranes based on them is examined. In conclusion, various applications of the membranes based on the perfluorinated polymers (predominantly amorphous Teflon AF) in separation processes are described.     

Properties of 2-hydroxy-ethylmethacrylate copolymers and hydrogels based on them

Data on properties of 2-hydroxy-ethylmethacrylate copolymers and hydrogels obtained on their basis are generalized. The effect of conditions of preparation of the hydrogels on their swelling degree in water is analyzed. Peculiarities of swelling of the hydrogels in aqueous solutions of inorganic salts are studied. Properties of hydrogels modified by silicon rubber are presented.     

Occurrence, biological activities and synthesis of kaurane diterpenes and their glycosides

This paper presents a review on kaurane diterpenes and their glycoside derivatives, covering aspects of their occurrence, biological activities and the synthesis of these natural products and their analogues. First, it shows and classifies diterpenes, in accordance with the already established structural criteria in the literature. Then, kaurane diterpenes are presented, focusing on their chemical structures, occurrence in the plant kingdom and their main, recently described, biological activities. Moreover, the most significant works, published between 1964 and November 2006, which describe the total synthesis or structural transformations of some kaurane diterpenes, including either semisynthetic and/or microbiological methodologies, are consisely reviewed. At this point, some general considerations on glycosides are introduced, and kaurane glycosides are presented and discussed on the basis of their toxic importance and occurrence in the plant kingdom, having focused on related aspects of their biological activities and the relationships between these activities and the structural factors of their molecules. Finally, the principal methods of glycosidation by enzymatic and chemical processes are both presented, and a few papers on the synthesis of kaurane glycosides are succinctly discussed.     

The role of cyclodextrins in chiral capillary electrophoresis

The members of the enantiomeric pairs frequently show rather different biological effects, so their chiral selective synthesis, pharmacological studies and analysis are necessary. CE has unique advantages in chiral analysis. The most frequently used chiral selectors are CDs in this field. This paper gives a short view on the advantages on CE in direct chiral separations, emphasizing the role of CDs. The reason for the broad selectivity spectra of CDs is discussed in detail. The physical background of chiral selective separations is briefly shown in CE. Their interaction mechanisms are shortly defined. The general trend of their use is statistically evaluated. Most frequently used CDs and CD derivatives are characterized. Advantages of ionizable CDs and single-isomer derivatives are shown. The general trend of their use is established.     

Inorganic material coatings and their effect on cytotoxicity

Inorganic materials have become an increasingly researched topic due to their applications in many areas especially health care. One major problem with them is the effect that their surface coatings have on cells. The same coatings that are meant to increase biocompatibility can actually invoke cytotoxicity. This tutorial review focuses on the various types of coatings and how their properties, such as electrostatic charge and hydrophobicity, affect the observed toxicity. The theorized mechanisms by which the coatings induce toxicity are also presented. Finally, the prospects for the future of this field are discussed.     

填充型聚合物基气敏导电复合材料

碳黑;综述;填充型聚合物基气敏导电复合材料