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Modification chemical

Chlorpyrifos emulsion concentrate produced by Dow Chemical containing 4 lb chlorpyrifos per gallon (2060 g L ) [47]. [Pg.173]

When mortality assessment experiments were carried out with Helicoverpa zea (a foliar-feeding lepidopteran with an alkaline gut), the LCjq values at 2 DAT for Lorsban 4E, standard aminoplast microcapsules and microcapsules with 90% disulfide Hnkages were 14.5, 96.4 and 14.7 ppm, respectively. The results indicated that microcapsules made only of aminoplast resin did not have disulfide linkages and thus did not break down in the gut of the insect, as indicated by the higher LC5Q value. However, those microcapsules with disulfide linkages ruptured in the insect gut and provided comparable control to that with Lorsban 4E. [Pg.174]

F re 5.17 Release of insecticide from Landec and conventional microcapsules [48]. [Pg.174]

Microcapsules can be made to release their contents on exposure to light by incorporating into the core of the microcapsule a material that photochemically eliminates a gaseous product. Mathiowitz and Raziel have described such system, which involves polyamide microcapsules prepared by interfadal polycondensation of [Pg.174]

The reason for choosing polyamide as the encapsulating polymer is that it has low permeability to nitrogen, is transparent to near-UV light, and is chemically stable to the photoeliminator used. The mechanism of microcapsule rupture is due to AIBN, on UV irradiation, producing N2 gas which leads to a build-up of pressure within the capsule. [Pg.175]

In conclusion, the macromolecular properties of polymers and their interactions with cell surfaces result in a specific pharmacokinetic behaviour of polymers. The routes of parenteral administration are far from being equivalent, e.g. the intraperi-toneal application often used cannot substitute the intravenous administration. Molecular parameters of the polymer circulating in the coitral compartment are changed in time not necessarily by a direct biological modification of the polymer but as a consequence of a selective processing of different fractions. The intracellular accumulation in secondary lysosomes is the only proven mode of persistence of a soluble polymer in tissues. Variations in the chemical structure of the polymer may result in a different pattern of polymer distribution in the body as a consequence of a different rate of cellular accumulation. [Pg.28]

An animal body is a chemically very active milieu, rich in a great variety of biocatalysts, reactive molecules and even radicals. As mentioned above, each of the body compartments exhibits a certain chemical activity. Liver cells are most active in this respect, followed by the kidney, RES, white blood cells, intestinal mucosa, etc. Foreign compounds which enter the body by any route except orally — called xenobiotics — are chemically modified, usually into a form that can be more easily eliminated from the body. The whole spectrum of modification reactions can by roughly grouped into the following classes  [Pg.28]

Lactulose is usually used as a 50% syrup but a crystalline trihydrate, which has very low hygroscopicity, is now available. [Pg.48]

Lactitol. Lactitol (4-0-j8-D-galactopyranosyl-D-sorbitol), is a synthetic sugar alcohol produced on reduction of lactose, usually using Raney nickel. It can be crystallized as a mono- or di-hydrate. Lactitol is not metabolized by higher animals it is relatively sweet and hence has potential as a non-nutritive sweetener. It is claimed that lactitol reduces the absorption of sucrose, blood and liver cholesterol levels and to be anticariogenic. It has applications in low-calorie foods (jams, marmalade, chocolate, baked goods) it is non-hygroscopic and can be used to coat moisture-sensitive foods, e.g. sweets. [Pg.48]


The modem fermentation industries developed from the early era of antibiotics. Over 4000 antibiotics have been discovered since the 1950s. However, only about 100 are produced on a commercial scale and over 40 of these are prepared by a combination of microbial synthesis and chemical modifications. Antibiotics produced by fermentation and used as starting materials in chemical syntheses are given in Table 2. [Pg.178]

Textile dyes were, until the nineteenth century invention of aniline dyes, derived from biological sources plants or animals, eg, insects or, as in the case of the highly prized classical dyestuff Tyrian purple, a shellfish. Some of these natural dyes are so-caUed vat dyes, eg, indigo and Tyrian purple, in which a chemical modification after binding to the fiber results in the intended color. Some others are direct dyes, eg, walnut sheU and safflower, that can be apphed directly to the fiber. The majority, however, are mordant dyes a metal salt precipitated onto the fiber facUitates the binding of the dyestuff Aluminum, iron, and tin salts ate the most common historical mordants. The color of the dyed textile depends on the mordant used for example, cochineal is crimson when mordanted with aluminum, purple with iron, and scarlet with tin (see Dyes AND DYE INTERMEDIATES). [Pg.423]

There are two main advantages of acrylamide—acryUc-based flocculants which have allowed them to dominate the market for polymeric flocculants in many appHcation areas. The first is that these polymers can be made on a commercial scale with molecular weights up to 10—15 million which is much higher than any natural product. The second is that their electrical charge in solution and the charge density can be varied over a wide range by copolymerizing acrylamide with a variety of functional monomers or by chemical modification. [Pg.33]

Additives. Because of their versatility, imparted via chemical modification, the appHcations of ethyleneimine encompass the entire additive sector. The addition of PEI to PVC plastisols increases the adhesion of the coatings by selective adsorption at the substrate surface (410). PEI derivatives are also used as adhesion promoters in paper coating (411). The adducts formed from fatty alcohol epoxides and PEI are used as dispersants and emulsifiers (412). They are able to control the viscosity of dispersions, and thus faciHtate transport in pipe systems (413). Eatty acid derivatives of PEI are even able to control the viscosity of pigment dispersions (414). The high nitrogen content of PEIs has a flame-retardant effect. This property is used, in combination with phosphoms compounds, for providing wood panels (415), ceUulose (416), or polymer blends (417,418) with a flame-retardant finish. [Pg.13]

Sulfonylureas. The hypoglycemic effect of sulfonylureas was first noted in the early 1940s when several patients died in hypoglycemic coma after testing glyprothia2ole, a synthetic sulfonamide used to treat typhoid. Chemical modifications which enhanced activity and lowered toxicity led to the development of the first-generation sulfonylureas. Carbutamide [339-43-5] the first commercial sulfonylurea, came onto the European... [Pg.341]

The aromatic ring of a phenoxy anion is the site of electrophilic addition, eg, in methylolation with formaldehyde (qv). The phenoxy anion is highly reactive to many oxidants such as oxygen, hydrogen peroxide, ozone, and peroxyacetic acid. Many of the chemical modification reactions of lignin utilizing its aromatic and phenoHc nature have been reviewed elsewhere (53). [Pg.143]

Post-curing and chemical modification improves chemical and solvent resistance (20). Paraformaldehyde and acetylene diurea are added to a hot borax solution. Toluenesulfonamide (p and o), a few drops of phosphorous acid. Brilliant Yellow 6G [2429-76-7] Rhodamine E3B, and Rhodamine 6GDN [989-38-8] are added. After heating, the mass is cured in an oven at 150°C. The resulting cured resin is thermoset but can be ground to fine particle sizes. [Pg.301]

Bacterial removal of sterol side chains is carried out by a stepwise P-oxidation, whereas the degradation of the perhydrocyclopentanophenanthrene nucleus is prevented by metaboHc inhibitors (54), chemical modification of the nucleus (55), or the use of bacterial mutants (11,56). P-Sitosterol [83-46-5] (10), a plant sterol, has been used as a raw material for the preparation of 4-androstene-3,17-dione [63-05-8] (13) and related compounds using selected mutants of the P-sitosterol-degrading bacteria (57) (Fig. 2). [Pg.310]

A Acetylation, O-Phosphorylation, and O-Adenylylation. A/-Acetylation, O-phosphorjiation, and O-adenyljiation provide mechanisms by which therapeutically valuable aminocyclitol antibiotics, eg, kanamycia [8063-07-8] gentamicin [1403-66-3] sisomicin [32385-11-8], streptomycia [57-92-1], neomycin, or spectinomycin are rendered either partially or completely iaactive. Thus, eg, kanamycia B [4696-78-8] (50) can be iaactivated by modification at several sites, as shown. The elucidation of these mechanisms has allowed chemical modification of the sites at which the iaactivation occurs. Several such bioactive analogues, eg, dibekacia and amikacin have been prepared and are not subject to the iaactivation hence, they inhibit those organisms against which the parent antibiotics are iaeffective (96) (see Antibacterial agents, synthetic). [Pg.314]

Selective Toluene Disproportionation. Toluene disproportionates over ZSM-5 to benzene and a mixture of xylenes. Unlike this reaction over amorphous sihca—alumina catalyst, ZSM-5 produces a xylene mixture with increased -isomer content compared with the thermodynamic equihbtium. Chemical modification of the zeohte causing the pore diameter to be reduced produces catalysts that achieve almost 100% selectivity to -xylene. This favorable result is explained by the greatly reduced diffusivity of 0- and / -xylene compared with that of the less bulky -isomer. For the same reason, large crystals (3 llm) of ZSM-5 produce a higher ratio of -xyleneitotal xylenes than smaller crystahites (28,57). [Pg.458]

Chemical modification of the wax can improve smear resistance (5). Sihcones, which do not harm furniture finishes (6), are incorporated as film-forming ingredients in furniture pohshes. The lubricant properties of sihcones improve ease of apphcation of the pohsh and removal of insoluble soil particles. In addition, sihcones make dry films easier to buff and more water-repeUent, and provide depth of gloss, ie, abihty to reflect a coherent image as a result of a high refractive index (7). Wax-free pohshes, which have sihcones as the only film former, can be formulated to dehver smear resistance (8). Another type of film former commonly used in oil-base furniture pohshes is a mineral or vegetable oil, eg, linseed oil. [Pg.209]

Biodegradable polymers and plastics are readily divided into three broad classifications (/) natural, (2) synthetic, and (J) modified natural. These classes may be further subdivided for ease of discussion, as follows (/) natural polymers (2) synthetic polymers may have carbon chain backbones or heteroatom chain backbones and (J) modified natural may be blends and grafts or involve chemical modifications, oxidation, esterification, etc. [Pg.477]

Although blending with other coating resins provides a variety of ways to improve the performance of alkyds, or of the other resins, chemically combining the desired modifier into the alkyd stmcture eliminates compatibiUty problems and gives a more uniform product. Several such chemical modifications of the alkyd resins have gained commercial importance. [Pg.42]

Lincomycin. The liacomycias and celesticetins are a small family of antibiotics that have carbohydrate-type stmctures. Clindamycin, a chemical modification of lincomycin, is clinically superior. Antibiotics ia this family inhibit gram-positive aerobic and anaerobic bacteria by interfering with proteia biosyathesis. [Pg.474]

For fabrics of thermoplastic fibers, permanent effects are obtainable if heat and pressure are appHed to soften the material. Processes dealing with carpets, nonwovens, and chemical modifications or additions that occur before the fiber is formed are not discussed herein (see Nonwoven fabrics). [Pg.442]

Treatments with Chemicals or Resins. Resin treatments are divided into topical or chemical modifications of the fiber itself. Most chemical treatments of synthetic fibers are topical because of the inert character of the fiber itself and the general resistance of the fiber to penetration by reagents. By contrast, ceUulosics and wool possess chemical functionality that makes them reactive with reagents containing groups designed for such purchases. Natural fibers also provide a better substrate for nonreactive topical treatments because they permit better penetration of the reagents. [Pg.442]

The wrinkle recovery angle provides a measure of the degree of chemical modification. This is calculated by blending a small sample and measuring the recovery to the flat configuration (180°). Whereas the untreated cotton recovers approximately 90°, the cross-linked cotton sample recovers 120—140°. If this is measured on dry fabric, it is termed conditional wrinkle recovery angle if on wet fabric, it is termed wet wrinkle recovery. At one point, wet wrinkle recovery was important, particularly in Europe. In the United States, the widespread use of clothes dryers has made conditional wrinkle recovery important. [Pg.443]

Although the antibacterial spectmm is similar for many of the sulfas, chemical modifications of the parent molecule have produced compounds with a variety of absorption, metaboHsm, tissue distribution, and excretion characteristics. Administration is typically oral or by injection. When absorbed, they tend to distribute widely in the body, be metabolized by the Hver, and excreted in the urine. Toxic reactions or untoward side effects have been characterized as blood dyscrasias crystal deposition in the kidneys, especially with insufficient urinary output and allergic sensitization. Selection of organisms resistant to the sulfonamides has been observed, but has not been correlated with cross-resistance to other antibiotic families (see Antibacterial AGENTS, synthetic-sulfonamides). [Pg.403]

Reactions. Although carbapenems are extremely sensitive to many reaction conditions, a wide variety of chemical modifications have been carried out. Many derivatives of the amino, hydroxy, and carboxy group of thienamycin (2) have been prepared primarily to study stmcture—activity relationships (24). The most interesting class of A/-derivatives are the amidines which are usually obtained in good yield by reaction of thienamycin with an imidate ester at pH 8.3. Introduction of this basic but less nucleophilic moiety maintains or improves the potency of the natural material while greatiy increasing the chemical stabiUty. Thus /V-formimidoyl thienamycin [64221-86-9] (MK 0787) (18), C 2H yN204S, (25) was chosen for clinical evaluation and... [Pg.5]


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4"-Hydroxyl group, chemical modification

4"-Hydroxyl group, chemical modification before

Acrylonitrile butadiene styrene chemical modification

Acrylonitrile chemical modification

Active site chemical modification

Active-site-directed chemical modifications

Affinity labeling, chemical modification

Affinity-labelling chemical modification

Affinity-labelling chemical modification experiments

Alkaline phosphatase chemical modification

Amino acid functional groups chemical modifications

Amino acid residues chemical modification sites

Amino acid residues, chemical modification

Amino acids chemical modification

Amino acids chemical modification reagents

Amino groups chemical modifications

Antibacterial property chemical modifications

Antibiotics chemical modifications

Antibody combining site chemical modification

Antimicrobial activity chemical modifications

Applications, molecular electronics chemical modifications

Arginine chemical modification reagents

Bacterial cellulose chemical modifications

Bacteriophage chemical modification

Barrier via chemical modification

Biomaterials chemical modifications

Biopolymer chemical surface modification

Blending modification chemical

Blending modification physical-chemical

Bonded phase Chemically modification

CHEMICAL MODIFICATION Subject

Calcium chemical modification

Carbon chemical modification

Carbon chemical modification/derivatization

Carbon nanotubes chemical modification

Carboxyl Chemical modification

Carboxyl groups chemical modifications

Carboxypeptidases chemical modification

Cell wall polymers, chemical modification

Cellulose chemical modification

Cellulose graft copolymers chemical modifications

Cellulose homogeneous chemical modification

Cellulose nanocrystals chemical modification

Chain-end chemical modification

Chemical Analogous Modifications in Collagen Molecule

Chemical Changes in Wood due to Thermal Modification

Chemical Modification and Site-Directed Mutagenesis

Chemical Modification for CNT Sorting

Chemical Modification for cis Nitro Configuration

Chemical Modification of Chitin and Chitosan

Chemical Modification of Fibers

Chemical Modification of Inulin

Chemical Modification of Montmorillonite

Chemical Modification of NR

Chemical Modification of Peptide and Protein Biopharmaceuticals

Chemical Modification of Polymer Structure

Chemical Modification of Polymeric Materials

Chemical Modification of Polysilanes

Chemical Modification of Polysiloxanes

Chemical Modification of Starch

Chemical Modification of siRNA

Chemical Modification to Enhance Affinity

Chemical Modifications of Hyaluronic Acid

Chemical Modifications of the

Chemical Structure Modification

Chemical dealumination, modification

Chemical enzyme modifications

Chemical industry modifications

Chemical method and pathway of CD modification

Chemical modification (before

Chemical modification Local

Chemical modification alkylated chitosans

Chemical modification avermectin family

Chemical modification carboxypeptidase

Chemical modification cation-exchange process

Chemical modification conditions

Chemical modification corona treatment

Chemical modification cross-linking agents

Chemical modification definition

Chemical modification description

Chemical modification erythromycin

Chemical modification etching

Chemical modification flame treatment

Chemical modification ionic interactions

Chemical modification methods

Chemical modification montmorillonite

Chemical modification of alkoxide

Chemical modification of amino acid

Chemical modification of amino acid residues

Chemical modification of electrode

Chemical modification of electrode surfaces

Chemical modification of enzyme

Chemical modification of functional

Chemical modification of functional groups

Chemical modification of lignocellulosic fibers

Chemical modification of polymer surface

Chemical modification of polymers

Chemical modification of protein

Chemical modification of semiconductor surfaces

Chemical modification of soy

Chemical modification of soy proteins

Chemical modification of surfaces

Chemical modification of the membrane

Chemical modification of the membrane surface

Chemical modification of titanium

Chemical modification oxidative methods

Chemical modification penetration

Chemical modification polymer materials

Chemical modification procedure

Chemical modification process

Chemical modification reactants

Chemical modification spiramycin

Chemical modification strategy

Chemical modification technique

Chemical modification to produce

Chemical modification tylosin

Chemical modification yield

Chemical modification, advantages

Chemical modification, dissolution

Chemical modification, liquid crystalline ionic

Chemical modification, liquid crystalline ionic liquids

Chemical modification, natural fiber

Chemical modification, natural fiber alkali treatment

Chemical modification, natural fiber silane treatment

Chemical modification, of milk protein

Chemical modification, stabilization

Chemical modification, types

Chemical modification, zeolites

Chemical modifications arginine residues

Chemical modifications cobalt enzyme

Chemical modifications current application

Chemical modifications cysteine residues

Chemical modifications denaturation

Chemical modifications disulfide group

Chemical modifications effect

Chemical modifications enzymatic

Chemical modifications food proteins, objectives

Chemical modifications histidine residues

Chemical modifications imidazole groups

Chemical modifications phenolic groups

Chemical modifications properties

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Chemical modifications temperature

Chemical modifications, active

Chemical modifications, expressed proteins

Chemical modifications, implant materials

Chemical modifications, viral particles

Chemical refining modifications

Chemical surface modification

Chemical surface modification methods

Chemical work modification

Chemically Modified Mutants, a Marriage of Chemical Modification and Protein Engineering

Chemicals) modification studies

Chemistry, protein chemical modifications

Chitin chemical modification

Chitosan Chemical modification

Chloromethyl polystyrene chemical modification

Cobrotoxin chemical modification

Combining Site-directed Mutagenesis with Chemical Modification

Covalent chemical modifications

Custom-Tailored Pharmacokinetics and Pharmacodynamics via Chemical Modifications of Biotech Drugs

Cysteine chemical modification reagents

Derivatization chemical modification

Direct Chemical Modification

Drugs chemical modification

Effect of Chemical Modifications

Electrode surfaces chemical modification

Elucidation of Protein Function by Chemical Modification

Fiber chemical modification

Flavors chemical modification

Fluorination chemical reactivity modification

Functional properties chemical modification

Glucose oxidase chemical modification

Glutamate dehydrogenase chemical modification

Graphite Modification by Mild Oxidation and Chemically Bonded (CB) SEI

Heparin chemical modification

Histidine chemical modification reagents

Hollow fibers chemical modification

Hyaluronic acid chemical modifications

Hydroformylation chemical modifications

Hydroxylated surfaces, chemical modification

Identification by Chemical Modification of Peptides

Immobilization and Chemical Modification

Inhibitor binding chemical modifications

Intestine chemical modification

Ionomer chemical modification

Keratins chemical modification

Kidney chemical modification

Lactose chemical modifications

Lignin Chemical modifications

Line-Shape Modifications Involving Chemical Shift Averaging

Lipase chemical modification

Liquid products chemical modification

Liver chemical modifications

Local chemical modification surface grafting

Lysine chemical modification reagents

Macrolide antibiotics, 16-membered chemical modifications

Mammals chemical modification

Materials, chemical modification

Metabolite chemical modification

Metal preparation chemical modification

Methionine residues chemical modification

Microgels chemical modifications

Milk proteins chemical modification

Modification and simplification of chemical spaces

Modification by chemical means

Modification by chemical methods

Modification by chemical modifiers

Modification chemical side reactions during

Modification of Chemical Reactivity Enzyme Inhibitors

Modification of Coconut Fibers by Chemical Treatment

Modification, chemical reactivity hazard

Modifications chemical plant

Natural fiber chemical modification process

Natural rubber chemical modification

Natural rubber nanocomposites chemical modification

New Biocatalysts via Chemical Modifications

Nucleic acids chemical modification

Olefin chemical modification

Oligomers chemical modification

Oligonucleotides chemical modification

Ovomucoid, chemical modification

Oxidation products chemical modifications

PDMS Surface Modification chemical grafting

Peptide fragments, chemical modification

Phenolics Chemical modification

Physical and Chemical Modifications

Physical-chemical modifications

Physico-chemical modification

Plasma-enhanced chemical vapor deposition modification

Plastics chemical modification techniques

Plastics surface preparation chemical modification

Poly chemical modification

Poly chemical structure modification

Polydienes, chemical modification

Polyethylene glycol chemical modification

Polymer grafting chemical modification

Polymer modification chemical

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Polymers, chemical modification double bonds

Polymers, chemical modification solvent

Polyolefins chemical modification

Polyphenylenes chemical modification

Polystyrene (PS) and its Chemical Modifications

Polystyrene sulfone chemical modification

Polyvinyl chemical modification

Post-synthesis Chemical Modification of Poly(styrene)

Posttranslational chemical modification

Properties functional, altered through chemical modification

Protein crystallization chemical modifications

Proteins chemical modification

RRNA chemical modification

Reaction chemical modification

Reactivity and Chemical Modification of Polymers

Reagents chemical modification

Reinforced polymer composites chemical modification treatments

Resists chemical modifications

Reversible chemical modifications

Rubber modification, chemical

Sample modification, chemical

Selective chemical modification

Serine chemical modification reagents

Serine residues chemical modification

SiRNAs molecules chemical modifications

Silica chemical modifications

Site-directed mutagenesis chemical modification with

Site-specific chemical modifications

Solid catalysts chemical modification

Spectral chemical modification

Stabilization and Chemical Modification of Zeolites

Stabilization by chemical modification

Starch chemical modification

Structure Modification in Chemical Databases

Subtilisin chemical modification

Surface Chemical Modification for Bonding

Surface Chemical Modification for UV Stability

Surface Modification by Chemical Reaction

Surface chemical modification polymeric materials, plasma

Surface chemical modification polymerization

Surface modification chemical mechanisms

Synthetic Control of DNA Triplex Structure Through Chemical Modifications

TOPICAL chemical modification

Tandem chemical modification

Tertiary Structure Characterisation by Chemical Modification and Mass Spectrometry

The Chemical Modification of Polymers

The Effect of Chemical Modification on Ultraviolet Absorption

Thermoplastic elastomer, chemical modification

Thiol-ene Reactions for Chemical Modifications after Polymerisation

Threonine residues chemical modification

Transitions chemical surface modifications

Tryptophan chemical modification reagents

Tryptophan residues chemical modification

Tyrosine chemical modification reagents

Tyrosine residues chemical modification

Uses of chemical modification

Vegetable oils chemical modification

Vitamin chemical modification

Wet Chemical Surface Modification

Whey modification, chemical

Wood Modification: Chemical. Thermal and Other Processes C. Hill

Wood Modification: Chemical. Thermal and Other Processes C. Hill 2006 John Wiley Sons, Ltd

Wood-plastic composites chemical modifications

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