Carbon nanotubes1, 2 might be usefully employed in nanometre-scale engineering and electronics. Electrical conductivity measurements on the bulk material3, 4, on individual multi-walled5, 6 and single-walled7 nanotubes and on bundles of single-walled nanotubes8, 9 have revealed that they may behave as metallic, insulating or semiconducting nanowires, depending on the method of production—which controls the degree of graphitization, the helicity and the diameter. Measurements of Young's modulus show10 that single nanotubes are stiffer than commercial carbon fibres. Methods commonly used to generate nanotubes—carbon-arc discharge techniques1, 2, 4, catalytic pyrolysis of hydrocarbons11, 12 and condensed-phase electrolysis13, 14—generally suffer from the drawbacks that polyhedral particles are also formed and that the dimensions of the nanotubes are highly variable. Here we describe a method for generating aligned carbon nanotubes by pyrolysis of 2-amino-4,6-dichloro-s-triazine over thin films of a cobalt catalyst patterned on a silica substrate by laser etching. The use of a patterned catalyst apparently encourages the formation of aligned nanotubes. The method offers control over length (up to about 50 mum) and fairly uniform diameters (30–50 nm), as well as producing nanotubes in high yield, uncontaminated by polyhedral particles.

Controlled production of aligned-nanotube bundles

Systems are disclosed which utilize implanted glucose sensitive living cells to monitor blood glucose levels. The implanted cells produce a detectable electrical or optical signal in response to changes in glucose concentration in surrounding tissue. The signal is then detected and interpreted to give a reading indicative of blood glucose levels. Capsules containing glucose sensitive cells and electrodes for detecting electrical activity are also disclosed. Methods of monitoring blood glucose are also described utilizing the systems and capsules disclosed.

System for monitoring and controlling blood glucose

Current trends in interfacial polymerization chemistry

Publisher Summary This chapter provides an overview of neoglycoproteins. A neoglycoprotein is defined as a glycoprotein produced chemically, in vitro , by the covalent attachment of monosaccharides or oligosaccharides to proteins that may or may not already contain naturally occurring, covalently bound carbohydrate. Excluded from this category are glycoproteins whose carbohydrate moieties are extended, in vitro , by glycosyltransferases, or altered by enzymes or other reagents. The applications of neoglycoproteins for investigating the contribution of carbohydrate to the functions mediated by glycoproteins are only now beginning to be explored. The ways in which neoglycoproteins have been used to study lectins and carbohydrate-specific antibodies could be extended to the study of other carbohydrate-binding proteins such as glycosyltransferases. Neoglycoproteins may also serve as soluble inhibitors of processes that are apparently glycoconjugate-mediated such as cell-cell adhesion. Still another possible approach to investigate the role of carbohydrate in the behavior of cells would be to attach new sugars to the cell surface by using the methods developed to prepare neoglycoproteins. The chapter describes the preparation of neoglycoproteins and desired characteristics of modification reactions. It discusses the properties of neoglycoproteins and elaborates the applications of neoglycoproteins and modification reactions.

Neoglycoproteins: the preparation and application of synthetic glycoproteins.

Systems are disclosed which utilize implanted chemo-sensitive living cells to monitor tissue or blood concentration levels of chemicals. The implanted cells produce a detectable electrical, optical or chemical signal in response to changes in concentration in surrounding medium. The signal is then detected and interpreted to give a reading indicative of blood concentration levels. Capsules containing chemo-sensitive cells and electrodes for detecting electrical activity are also disclosed. Methods of monitoring the concentration are also described utilizing the systems and capsules disclosed.

System for monitoring and controlling blood and tissue constituent levels

Cyanuric Chloride Derivatives. I. Aminochloro-s-triazines

Cyanuric Chloride Derivatives. II. Substituted Melamines

A meta- or para-compound of the formula: ##STR1## wherein: X⊖ is an anion selected from the group consisting of R 4 OSO 3 ⊖, Cl⊖, Br⊖ and I⊖; A is -O- or ##STR2## wherein: n is 2 or 3; R 1 , R 2 and R 3 which may be the same or different, are lower alkyl; and R 4 is lower alkyl or allyl. Also disclosed is a method of making the compound by reacting meta- or para-isopropenyl-α,α-dimethylbenzyl isocyanate with either an amino alcohol or a dialkylaminoethyleneamine, and quaternzing the reaction product with an alkylating agent. The compound may be polymerized with a co-monomer such as acrylamide to yield water-soluble cationic polymers for use in water clarification, flocculation, and hair spray applications.

Quaternary amine carbamate or urea compounds based on isopropenyl-α,α-dimethylbenzyl isocyanate

Cyanuric Chloride Derivatives. V. Reaction of Alkoxy-s-triazines and Aryloxy-s-triazines with Amines

An improved process for the preparation and purification of N-{p-([2,4-diamino-6-pteridinyl)-methyl]methylamino)benzoyl} glutamic acid, also known as methotrexate, using the alkali metal, calcium and zinc salts of N-methyl-p-aminobenzoylglutamate, tetraaminopyrimidine sulfate, 1,1,3-tribromoacetone and the alkali metal and zinc salts of methotrexate.

Frederic C Schaefer

Papers

Cyanuric Chloride Derivatives. I. Aminochloro-s-triazines

Cyanuric Chloride Derivatives. II. Substituted Melamines

Quaternary amine carbamate or urea compounds based on isopropenyl-α,α-dimethylbenzyl isocyanate

Cyanuric Chloride Derivatives. V. Reaction of Alkoxy-s-triazines and Aryloxy-s-triazines with Amines

Process for the preparation of high purity methotrexate and derivatives thereof