Two-component regulatory systems play a major role in the physiological response of bacteria to environmental stimuli. Such systems are composed of a sensor histidine kinase and a response regulator whose ultimate function is to affect the expression of target genes. Response regulator mutants of Campylobacter jejuni strain F38011 were screened for sensitivity to sodium deoxycholate. A mutation...

The effects of extracellular fluid volume expansion on intestinal transport of salts and water were studied in dogs by perfusing loops of bowel in vivo. Saline loading caused depression of duodenal and jejunal absorption with net secretion of salt and water into the lumen. Studies of unidirectional transport of (22)Na(+) revealed that the negative net sodium flux was due primarily, and perhaps ...

Unilateral chorda tympani nerve sectioning was combined with institution of a sodium-restricted diet in adult rats to determine the role that environment has on the functional properties of regenerating taste receptor cells. Rats receiving chorda tympani sectioning but no dietary manipulation (cut controls) and rats receiving only the dietary manipulation (diet controls) had normal responses to...

The production of acetic acid by Clostridium thermoaceticum was studied by using batch fermentations. In a pH-controlled fermentation with sodium hydroxide (pH 6.9), this organism was able to produce 56 g of acetic acid per liter. On the other hand, when the pH was not controlled and was decreased during fermentation to 5.4, the maximum attainable acetic acid concentration was only 15.3 g/liter...

Sparingly dissoluble calcium salts were studied as reactants in the synthesis of needlelike precipitated calcium carbonate (PCC). Morphology and aspect ratio of the PCC particle were characterized with SEM. Polymorphs and crystal size were characterized using x-ray diffraction. The counter-ions of the sparingly dissoluble salts influenced growth kinetics of PCC as well as the polymorphs and mor...

In a previous report, the synthesis of p-hydroxybenzoic acid and salicylic acid from alkali phenoxides and carbon dioxide in aprotic-polar solvents was reported. In the present study, the effects of reaction conditions on the yields and the rule of orientation under atmospheric pressure were examined in a typical aprotic-polar solvent, N,N-dimethylfomamide. Stabilities of the alkali salts of p-...

Eggs of Artemia salina L., the brine shrimp, are easily obtainable in large quantities. Ecdysis takes place in two stages: (a) extrusion of the inner membrane, and (b) ecdysis of the nauplius from that membrane. The conditions which allow for the former are much more varied than those for the latter. Nauplii form in only solutions of a few sodium salts; and, in Mg, Ca, and Sr salts, potassium i...

In the last several decades, significant efforts have been conducted to understand the fundamental reactivity of glucose derived from plant biomass in various chemical environments for conversion to renewable fuels and chemicals. For reactions of glucose in water, it is known that inorganic salts naturally present in biomass alter the product distribution in various deconstruction processes. Ho...

BACKGROUND In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100) or anionic (sodium lauryl ether sulfate)...

We studied nine solid and two liquid media for their suitability to select Aeromonas and Plesiomonas spp. from human stools, using artificially contaminated samples as well as 254 samples from outpatients with and without diarrhea. Media with optimal sensitivity and specificity for Aeromonas spp. were alkaline peptone-water, Trypticase soy broth with ampicillin, inositol-brilliant green-bile sa...