The chemical composition and antibacterial activity of the leaf extract of Salvia repens Burch Ex Benth

Chemical engineers apply the principles of chemistry to solve problems involving the production or u...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses th...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses th...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses un...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses en...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses ba...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses ba...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses co...

Professor Channing Robertson of the Stanford University Chemical Engineering Department continues hi...

Professor Channing Robertson of the Stanford University Chemical Engineering Department discusses en...

Isopropyl aminoethylmethyl phosphonite (NATO designation QL)...

In a chemical change, bonds are broken and new bonds are for...

Chemical compatibility is a measure of how stable a substanc...

In nuclear magnetic resonance (NMR), the chemical shift desc...

The Chemical Society was formed in 1841 (then named the Chem...

A chemical hazard arises from contamination with harmful or ...

1. In the introduction, a short survey on the effect of different structural isomers on the activity of drugs is giben. The inductive, resonance and steric effect of the ring substitution are discussed and probable mechanism of local-anesthetic action is dealth with. 2. As model substances in this work, the diethylamino-ethyl-ester-hydrochlorides of amino-, butylamino, butoxy- and butyl-benzoic acids are synthesized and their purity tests as well as the spectroscopic identifications are made. Further more the data on the pKa, ionisation degree,...

Recent developments in hazard identification and risk assessment of chemical mixtures are reviewed. Empirical, descriptive approaches to study and characterize the toxicity of mixtures have dominated during the past two decades, but an increasing number of mechanistic approaches have made their entry into mixture toxicology. A series of empirical studies with simple chemical mixtures in rats is described in some detail because of the important lessons from this work. The development of regulatory guidelines for the toxicological evaluation of c...

Abstract The surface silanol on Si3N4 can be successfully determined by reaction of the OH group with tridecafluoro-1,1,2,2-tetrahydrooctyl-1-1-trichlorosilane and subsequent electron spectroscopy for chemical analysis for F. The technique offers both specificity and very high sensitivity. It also has certain advantages over diffuse reflectance infrared Fourier transform, including more surface probing, better quantification, and a significantly lower detection limit.

Abstract The surface silanol on Si3N4 can be successfully determined by reaction of the OH group with tridecafluoro-1,1,2,2-tetrahydrooctyl-1-1-trichlorosilane and subsequent electron spectroscopy for chemical analysis for F. The technique offers both specificity and very high sensitivity. It also has certain advantages over diffuse reflectance infrared Fourier transform, including more surface probing, better quantification, and a significantly lower detection limit.

The purpose of this study was to compare heart rate, appearance rate and duration of ventricular tachycardia (VT) by transcoronary chemical ablation using 95% ethanol and 1% aethoxysclerol respectively. After the balloon which was guided to the left or right coronary artery with PTCA technique in anesthetized dogs was inflated, chemical ablation was performed using ethanol (n = 5) or aethoxysclerol (n = 5). These chemicals were administered at 0.05 ml/sec with total dose of 0.50-1.50 ml. A quadripolar electrode catheter was used to record the i...

Unusually large (13)C chemical shift differences are observed between neutral and protonated glycocyamidine (2-aminoimidazolinone) derivatives. Upon protonation, the guanidine (N-C=N) and carbonyl (C=O) carbons undergo an upfield shift of approximately 12 and 17 ppm, respectively, relative to the neutral species. For neutral glycocyamidine derivatives, the (13)C chemical shifts for the carbonyl carbon reside above 190 ppm. In the protonated form, the carbonyl resonances are in the mid to lower 170s. These values are indicative of the protonatio...

In this study we use a novel similarity search technique called latent semantic structure indexing (LaSSI) with joint chemical probes as queries to mine the MDL drug data report database. LaSSI is based on latent semantic indexing developed for searching textual databases. We use atom pair and topological torsion descriptors in our calculations. The results obtained with LaSSI are compared with another in-house similarity search technique TOPOSIM. The results from the similarity searches using joint chemical probes are significantly better than...

The Chemical Abstracts Service Chemical Registry System, operating since 1965, uniquely identifies chemical substances on the basis of molecular structure. Chemical Abstracts Service is now registering chemical substances cited in indexes to Chemical Abstracts prior to 1965. This effort will result in several hundred thousand additional chemical structures, along with their names, being available for online searching in the Registry File. Both the newly registered substances and those already on file are being linked to their pre-1965 citations...

Abstract The a priori kinetic optimization sometimes needed for process development has generally proven difficult for reactions governed by surface chemistry. The difficulty usually results from the considerable detail with which the component steps of the overall reaction must be understood. In the present work, we summarize advances in kinetic methodology that were required for fully modeling the chemical vapor deposition of titanium disilicide from TiCl4 and SiH4. Modifications of the ultrahigh vacuum (UHV) technique of temperature program...