Topic
Chemical modification
About: Chemical modification is a research topic. Over the lifetime, 5414 publications have been published within this topic receiving 128263 citations.
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TL;DR: CR-GO with the nature of a single sheet showing favorable electrochemical activity should be a kind of more robust and advanced carbon electrode material which may hold great promise for electrochemical sensors and biosensors design.
Abstract: In this paper, the characterization and application of a chemically reduced graphene oxide modified glassy carbon (CR-GO/GC) electrode, a novel electrode system, for the preparation of electrochemical sensing and biosensing platform are proposed. Different kinds of important inorganic and organic electroactive compounds (i.e., probe molecule (potassium ferricyanide), free bases of DNA (guanine (G), adenine (A), thymine (T), and cytosine (C)), oxidase/dehydrogenase-related molecules (hydrogen peroxide (H2O2)/β-nicotinamide adenine dinucleotide (NADH)), neurotransmitters (dopamine (DA)), and other biological molecules (ascorbic acid (AA), uric acid (UA), and acetaminophen (APAP)) were employed to study their electrochemical responses at the CR-GO/GC electrode, which shows more favorable electron transfer kinetics than graphite modified glassy carbon (graphite/GC) and glassy carbon (GC) electrodes. The greatly enhanced electrochemical reactivity of the four free bases of DNA at the CR-GO/GC electrode compare...
1,587 citations
TL;DR: A dynamic programming algorithm for prediction of RNA secondary structure has been revised to accommodate folding constraints determined by chemical modification and to include free energy increments for coaxial stacking of helices when they are either adjacent or separated by a single mismatch.
Abstract: A dynamic programming algorithm for prediction of RNA secondary structure has been revised to accommodate folding constraints determined by chemical modification and to include free energy increments for coaxial stacking of helices when they are either adjacent or separated by a single mismatch. Furthermore, free energy parameters are revised to account for recent experimental results for terminal mismatches and hairpin, bulge, internal, and multibranch loops. To demonstrate the applicability of this method, in vivo modification was performed on 5S rRNA in both Escherichia coli and Candida albicans with 1-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfonate, dimethyl sulfate, and kethoxal. The percentage of known base pairs in the predicted structure increased from 26.3% to 86.8% for the E. coli sequence by using modification constraints. For C. albicans, the accuracy remained 87.5% both with and without modification data. On average, for these sequences and a set of 14 sequences with known secondary structure and chemical modification data taken from the literature, accuracy improves from 67% to 76%. This enhancement primarily reflects improvement for three sequences that are predicted with <40% accuracy on the basis of energetics alone. For these sequences, inclusion of chemical modification constraints improves the average accuracy from 28% to 78%. For the 11 sequences with <6% pseudoknotted base pairs, structures predicted with constraints from chemical modification contain on average 84% of known canonical base pairs.
1,481 citations
Book•
01 Jan 2006
TL;DR: In this article, the use of wood is discussed in the twenty-first century and a number of techniques for modifying the properties of wood are presented. But none of them are suitable for outdoor use.
Abstract: Foreword. Series Preface. Preface. List of Abbreviations. 1. The Use of Timber in the Twenty-first Century 1.1 Introduction. 1.2 Nonrenewables: a Finite and Exhaustible Resource. 1.3 Renewable Materials. 1.4 The Global Timber Resource. 1.5 Timber Production. 1.6 Wood Preservation. 1.7 Preservative-treated Wood and Legislation. 1.8 Competition from Nonrenewable Materials. 1.9 The Need for Wood Modification. 1.10 Conclusions. 2. Modifying the Properties of Wood. 2.1 Introduction. 2.2 Wood Properties and Wood Modification. 2.3 Wood Modification Methods. 2.4 The Cell Wall of Wood. 2.5 The Chemical Constituents of Wood. 2.6 The Wood-Water Relationship. 2.7 The Mechanical Properties of Modified Wood. 2.8 Modified Wood and Biological Degradation. 2.9 Wood and Weathering. 2.10 Proof of Bonding. 2.11 Conclusions. 3. Chemical Modification of Wood (I): Acetic Anhydride Modification. 3.1 Introduction. 3.2 Reaction Protocols. 3.3 Cell Wall Reactivity. 3.4 Analysis of Anhydride-modified Wood. 3.5 Dimensional Stability. 3.6 Mechanical Properties. 3.7 Microbiological Degradation. 3.8 Biological Degradation by Insects and Marine Organisms. 3.9 Moisture Relationships of Anhydride-modified Wood. 3.10 Composites Utilizing Acetic Anhydride Modified Wood. 3.11 Conclusions. 4. Chemical Modification of Wood (II): Reaction with Other Chemicals. 4.1 Introduction. 4.2 Reaction of Wood with Other Noncyclic Anhydrides. 4.3 Reaction of Wood with Cyclic Anhydrides. 4.4 Acetylation Using Ketene Gas. 4.5 Carboxylic Acid Modification. 4.6 Acid Chloride Modification. 4.7 Isocyanate Modification. 4.8 Epoxide Modification. 4.9 Alkyl Halide Modification. 4.10 Aldehyde Modification. 4.11 Cyanoethylation. 4.12 Beta-Propiolactone. 4.13 Quinone Methides. 4.14 Conclusions. 5. Thermal Modification of Wood. 5.1 Introduction. 5.2 Process Variables. 5.3 Chemical Changes in Wood due to Thermal Modification. 5.4 Physical Changes in Wood due to Thermal Modification. 5.5 Biological Properties of Thermally Modified Wood. 5.6 Compressed Wood. 5.7 Oil Heat-treatments. 5.8 Conclusions. 6. Surface Modification. 6.1 Introduction. 6.2 Surface Chemical Modification for UV Stability. 6.3 Modification to Render the Wood Surface Hydrophobic. 6.4 Surface Chemical Modification for Bonding. 6.5 Enzymatic Modification. 6.6 Corona or Plasma Discharge. 6.7 Conclusions. 7. Impregnation Modification. 7.1 Introduction. 7.2 Resin Treatments. 7.3 Impregnations using Silicon-containing Compounds. 7.4 Other Inorganic Cell Wall Precipitation Treatments. 7.5 Cell Wall Impregnation with Monomers. 7.6 Cell Wall Impregnation with Polymers. 7.7 Conclusions. 8. Commercialization of Wood Modification. 8.1 Introduction. 8.2 Thermal Modification. 8.3 Oil Heat Modification/Treatments. 8.4 Acetylation. 8.5 Impregnation Modification. 8.6 Conclusions. 9. Wood Modification: Environmental Considerations and Future Developments. 9.1 Introduction. 9.2 Principles of the Determination of Environmental Impact. 9.3 Methods of Determining Environmental Impacts. 9.4 The Environmental Impact of Wood Modification. 9.5 Industrial Ecology and Wood Modification. 9.6 The Future of Wood Modification. References. Index.
1,192 citations
TL;DR: Increased utilization of mechanically stable synthetic matrices particularly silica gel as a solid support and its surface modification by impregnation of organic ligands directly or covalent grafting through spacer unit for extractive concentration of trace elements are highlighted in the present article.
860 citations