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Results 551 - 600 of 1130
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Moreaux B - - 2000
The purpose of this work was to investigate the role of tachykinins in cough induced by citric acid (0.8 M) in pigs. With this object, we have studied the effect of citric acid on substance P content in the tracheo-bronchial tree and the effects of substance P and of tachykinin ...
Orgel L E - - 2000
I examine the plausibility of theories that postulate the development of complex chemical organization without requiring the replication of genetic polymers such as RNA. One conclusion is that theories that involve the organization of complex, small-molecule metabolic cycles such as the reductive citric acid cycle on mineral surfaces make unreasonable ...
Ditengou F A - - 2000
Hypaphorine, the major indolic compound isolated from the ectomycorrhizal fungus Pisolithus tinctorius, controls the elongation rate of root hairs. At inhibitory concentrations (100 microM), hypaphorine induced a transitory swelling of root hair tips of Eucalyptus globulus Labill. ssp. bicostata. When the polar tip growth resumed, a characteristic deformation was still ...
Kirimura K - - 2000
In Aspergillus niger, a cyanide (CN)- and antimycin A-insensitive and salicylhydroxamic acid (SHAM)-sensitive respiratory pathway exists besides the cytochrome pathway and is catalyzed by the alternative oxidase (AOX). In this study, A. niger WU-2223L, a citric acid-producing strain, was cultivated in a medium containing 120 g/l of glucose, which is ...
Abu-Ghazaleh B M - - 2000
The effect of sodium chloride and citric acid on hemolysin and caseinase production by Aeromonas caviae and Aeromonas sobria at 32 degrees C and 5 degrees C was investigated. At 32 degrees C, although both strains were tolerant to 3% NaCl in TSB, the production of caseinase was decreased in ...
Laska M - - 2000
Taste-preference thresholds for five food-associated sugars and acids, respectively, as well as relative sweet-taste preferences were assessed in six pigtail macaques using two-bottle choice tests of brief duration (1 min). In experiment 1, the animals were found to significantly prefer concentrations as low as 10 mM maltose and sucrose, 20 ...
Rietveld S - - 2000
This experiment tested the hypothesis that the setting in which research is conducted may dominate symptom magnitude. Cough was induced with inhaled citric acid and its magnitude was influenced by changing the setting in 30 adolescents with asthma. Cough thresholds for citric acid were determined. The participants were assigned to ...
Chen Z H - - 2000
The aim of this study was to investigate whether gluconeogenesis catalysed by phosphoenolpyruvate carboxykinase (PEPCK) occurs during leaf senescence. This was addressed by determining changes in the abundance and intercellular location of enzymes necessary for gluconeogenesis during the senescence of barley leaves and cucumber cotyledons. PEPCK was never present in ...
Morowitz H J - - 2000
The core of intermediary metabolism in autotrophs is the citric acid cycle. In a certain group of chemoautotrophs, the reductive citric acid cycle is an engine of synthesis, taking in CO(2) and synthesizing the molecules of the cycle. We have examined the chemistry of a model system of C, H, ...
Rhee S H - - 2000
Hydroxyapatite (HAp) formation on cellulose cloth with the aid of citric acid was investigated. The cellulose cloths were soaked in simulated body fluid (SBF) solutions (1.5 SBF) with ion concentrations 1.5 times that of SBF (1.0 SBF) with and without citric acid and carbonate containing HAp crystals were found to ...
Li J - - 2000
Analysis of the content and distribution of organic acids in chickpea plants (Cicer arietinum L.) showed that malonate was the most abundant acid in roots and nodules, whereas malate was the main acid in leaves and stems. The highest concentration of malonate in roots was in the apices. Malonate metabolism ...
Saavedra L - - 2000
Fruit juices each have very distinct organic acids profiles that can be used as fingerprints for establishing authenticity. A method has been developed, optimised and validated for measuring by capillary electrophoresis citric, isocitric, malic and tartaric acids as authenticity markers in orange juices, without any sample treatment other than dilution ...
Kinoshita E - - 2000
The production mechanism of shoyuflavones, conjugated ethers of isoflavones with tartaric acid and isolated from fermented soy sauce, was studied. In the high molecular weight fraction of the culture extract of Aspergillus oryzae, genistein was transformed into shoyuflavone B in the presence of (+/-)-trans-epoxysuccinic acid but not in the low ...
Abu-Ghazaleh B M - - 2000
The respective and combined effects of sodium chloride, ascorbic acid, citric acid, potassium sorbate, and Thymus vulgaris extract on the growth of Aeromonas caviae and Aeromonas sobria were investigated. Sodium chloride (3%) significantly reduced the growth and 4% NaCl inhibited growth of the tested strains. Ascorbic acid (0. 1%), potassium ...
Begum F - - 2000
Mycotoxin-producing fungi were isolated from contaminated grains of rice, pulses and oilseeds sold in the local markets of Calcutta for human consumption. It was found that aflatoxin B1 was produced by Aspergillus flavus and Aspergillus parasiticus, aflatoxin G1 by A. flavus, ochratoxin by Aspergillus ochraceous, sterigmatocystin by Aspergillus japonicus and ...
Espinoza R - - 2000
Pelanserin is a weakly basic experimental drug with a short half-life and a prolonged release formulation was developed using hydroxypropyl methylcellulose (HPMC) and citric acid to set up a system bringing about gradual release of this drug. For this purpose powder mixtures were wet granulated with water and compressed with ...
Christian T J - - 2000
Thermal treatments of solid mixtures of inulin and citric acid result in the formation of di-D-fructose dianhydrides and oligomers derived therefrom. The kinetics of formation of these compounds have been investigated and simulated in computer studies. A mechanism is proposed. The conditions used in this study were analogous to the ...
Bayraktar E - - 2000
Conidia of Aspergillus niger were immobilized in calcium alginate gel for the production of citric acid. First, the type of the preactivation medium, together with the preactivation period, was investigated. It was found that A. niger requires a 2-d preactivation period at a 0.05 g/L NH4NO3 concentration. Second, preactivated cells ...
Arzumanov T E - - 2000
After analysis of batch culture and identification of the ways for prolongation of citric acid active synthesis by yeast, repeat-batch (RB) cultivation was suggested. Yarrowia lipolytica strain RB cultivation was studied and optimal conditions for cultivation selected. It was shown that when applying RB cultivation, better results were obtained than ...
Vincent G - - 2000
Cytosolic citrate is proposed to play a crucial role in substrate fuel selection in the heart. However, little is known about factors regulating the transfer of citrate from the mitochondria, where it is synthesized, to the cytosol. Further to our observation that rat hearts perfused under normoxia release citrate whose ...
Vélot C - - 2000
The enzymes of the Krebs tricarboxylic acid cycle in mitochondria are proposed to form a supramolecular complex, in which there is channeling of intermediates between enzyme active sites. While interactions have been demonstrated in vitro between most of the sequential tricarboxylic acid cycle enzymes, no direct evidence has been obtained ...
Al-Othman A O - - 2000
A fast method for sample treatment of phosphate rock has been developed for the purpose of quantitative leaching (98-100%) of fluoride but less of the interfering cations such as iron and aluminum. Citric acid (0.5 M) was used to extract fluoride in 15-45 min. Leaching of iron and aluminum is ...
Mourya S - - 2000
The present investigation explored the possible use of a rarely used agro-industrial by-product, maize starch-hydrolysate, for economic production of citric acid. To achieve this, seventeen strains of Aspergillus niger were screened for their capacity to produce citric acid using starch-hydrolysate as a substrate. The most efficient strain, ITCC-605 was selected ...
Metzger L E - - 2000
The effect of milk preacidification with acetic or citric acid on the composition and yield of low fat Mozzarella cheese was determined. Two cheese manufacturing trials were conducted. In trial 1, three vats (230 kg of milk per vat) of cheese were made in 1 d using no preacidification (control) ...
Shalaev E Y - - 2000
PURPOSE: Factors affecting the solid-state acid-catalyzed inversion of amorphous sucrose to glucose and fructose in the presence of colyophilized citric acid, with less than 0.1% w/w residual water, have been studied. METHODS: Samples of citric acid and sucrose were lyophilized at a weight ratio of 1:10 citric acid:sucrose from solutions ...
Tanner G A - - 2000
The kidney function in a model of autosomal dominant polycystic kidney disease (PKD), the Han:SPRD rat, is dramatically improved by chronic ingestion of a solution of potassium citrate and citric acid (KCitr). This study investigated whether this treatment would also be beneficial in the pcy/pcy mouse, a model of autosomal ...
Wayman F M - - 2000
Models for the known glucose transporters in Aspergillus niger and for simple diffusion of glucose through the hyphal membrane were prepared. The results from the models were compared with fermentation data from published studies on citric acid. It was found that the purely physical and uncontrolled process of diffusion could ...
Reilly S - - 2000
The present study reports two experiments that evaluated the influence of bilateral ibotenic acid lesions of the viscerosensory neurons in the lateral parabrachial nucleus (LPBN) on intake of four prototypical taste stimuli (sucrose, sodium chloride, citric acid, and quinine hydrochloride). In the 24-h, two-bottle tests of Experiment 1, rats with ...
Sekar C - - 2000
Effect of different auxins, namely, 2,4-dichlorophenoxyacetic acid (2,4-D), naphthalene acetic acid (NAA) and indole acetic acid (IAA) and Azospirillum brasilense bioinoculation on the enhancement of polygalacturonase (PG) activity in rice roots during para nodulation and endorhizosphere colonization of Azospirillum was studied under in vitro condition. It was observed that Azospirillum ...
Gisbert J P - - 2000
AIM: 13C-urea breath test is one of the best methods for the diagnosis of Helicobacter pylori infection. Although a citric acid solution is generally used prior to urea intake, the superiority of this strategy has not been sufficiently demonstrated. Thus, our aim was to compare 13C-urea breath test with and ...
Tsekova K - - 2000
Copper and cadmium inhibited the growth as well as citric acid production (depending on the heavy metal concentrations) by citric-acid-producing Aspergillus niger. Activity of citrate synthase was connected with citrate synthesis in the absence as well as in the presence of heavy metals. The activity of aconitase, and both NAD- ...
Li T Y - - 2000
The intact fungal spores of several strains of four Aspergillus species, Aspergillus flavus, A. oryzae, A. parasiticus, and A. sojae, were directly analyzed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry. Very simple MALDI mass spectra are obtained by directly mixing spores with a matrix such as alpha-cyano-4-hydroxycinnamic acid or ...
Di Lenarda R - - 2000
AIM: The aim of this study was to evaluate in vitro the cleansing and smear layer removal capability of alternate canal irrigation with citric acid and NaOCl. METHODOLOGY: Eighty-one teeth were divided into three groups on the basis of the type of instrumentation, namely, manual stainless steel, Ni-Ti mechanized ProFile ...
Mason G F - - 1999
13C isotopic labeling data were obtained by 1H-observed/13C-edited magnetic resonance spectroscopy in the human brain in vivo and analyzed using a mathematical model to determine metabolic rates in human grey matter and white matter. 22.5-cc and 56-cc voxels were examined for grey matter and white matter, respectively. When partial volume ...
Rhee S H - - 1999
The role of citric acid in a simulated body fluid (SBF) was examined with the main focus on its induction ability of hydroxyapatite (HAp) nucleation on a bioinert collagen membrane. Collagen membranes were soaked in the SBF with citric acid concentrations in the range of 0-4 mM; then, carbonate-containing HAp ...
Lin K H - - 1999
BACKGROUND AND PURPOSE: The purpose of this study was to compare the cough threshold between people with and without spinal cord injury (SCI). The effect of smoking on cough threshold was also investigated. SUBJECTS: The participants were 26 people with SCI (15 smokers, 11 nonsmokers) and 18 people without SCI ...
Carlson R W - - 1999
A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface ...
Berovic M - - 1999
To obtain high citric acid productivity in Aspergillus niger fermentation on beet molasses substrate, a certain redox potential profile with two maxima (260 and 280 mV) and two minima (180 and 80 mV) must be maintained. The most effective regulation of redox potential is by regulation of aeration and agitation. ...
Ruijter G J - - 1999
The external pH appeared to be the main factor governing oxalic acid production by Aspergillus niger. A glucose-oxidase-negative mutant produced substantial amounts of oxalic acid as long as the pH of the culture was 3 or higher. When pH was decreased below 2, no oxalic acid was formed. The activity ...
Bago B - - 1999
Arbuscular mycorrhizal (AM) fungi are obligate symbionts that colonize the roots of over 80% of plants in all terrestrial environments. Understanding why AM fungi do not complete their life cycle under free-living conditions has significant implications for the management of one of the world's most important symbioses. We used (13)C-labeled ...
Hamel R - - 1999
13C NMR studies on intact cells from Al-stressed Pseudomonas fluorescens incubated with citric acid or Al-citrate yielded peaks at 158 and 166 ppm that were attributable to free and complexed oxalic acid, respectively. The presence of oxalic acid was further confirmed with the aid of oxalate oxidase. These peaks were ...
Shigematsu Y - - 1999
In a neonatal-screening pilot study for inherited disorders in organic acid and amino acid metabolism, we analyzed butyrated acylcarnitines and amino acids in blood spots of more than 20,000 newborns by electrospray tandem mass spectrometry. In order to screen urea cycle disorders, we performed multiple scanning functions with additional stable ...
Gent J F - - 1999
The effect of a gymnemic acid (GA) rinse, which simulated a sweet-taste deficit, was measured on human taste perception and identification. Taste ratings showed that GA reduced the intensities of sucrose and aspartame to 14% of pre-rinse levels; over the recovery interval of 30 min, these values increased linearly to ...
Lan W C - - 1999
Root surface demineralization is widely used as an adjunct to periodontal treatment. To clarify the influence of citric acid root conditioning on periodontal wound healing, the effects of citric acid and associated extracellular acidosis on the viability (MTT assay), attachment and protein synthesis ([3H]-proline incorporation into trichloroacetic acid-precipitated proteins) of ...
Jana Asim K. - - 1999
The effect of citric acid metabolism by Xanthomonas campestris on composition of xanthan has been studied. Citric acid consumption in fed-batch and continuous fermentation increased the pyruvic acid content of xanthan. An increase in pyruvic acid content in xanthan has been explained with the help of energy balance in xanthan ...
London R E - - 1999
We have evaluated the use of [1,2-13C2]propionate for the analysis of propionic acid metabolism, based on the ability to distinguish between the methylcitrate and methylmalonate pathways. Studies using propionate-adapted Escherichia coli MG1655 cells were performed. Preservation of the 13C-13C-12C carbon skeleton in labeled alanine and alanine-containing peptides involved in cell ...
Graham D Y - - 1999
Test meals are used in the urea breath test to slow gastric emptying and to increase the area of contact with the substrate. Recently, citric acid has been suggested as an improved liquid test meal. The mechanism is unknown and could act by delaying gastric emptying, decreasing the pH at ...
Thomas B S - - 1999
This study compared the root surface characteristics produced by Minocycline HCl, Citric acid and Tetracycline HCl. when used as a root conditioner. This study included 5 groups of 10 extracted teeth each with advanced periodontal disease. Diseased root surfaces of group B,C,D and E were planed with Gracy curets and ...
Nwankwoala A U - - 1999
The batch culture degradation of NASA wastewater containing mixtures of citric acid, methylhydrazine, and their reaction product was studied. The organic contaminants present in the NASA wastewater were degraded by Achromobacter sp., Rhodococcus B30 and Rhodococcus J10. While the Achromobacter sp. showed a preference for the degradation of the citric ...
Wang L - - 1999
A method to determine chemical composition of natural resin shellac was developed on the basis of reactive pyrolysis-gas chromatography (Py-GC) in the presence of an organic alkali, tetramethylammonium hydroxide ((CH(3))(4)NOH, TMAH). Py-GC using 25% TMAH aqueous solution enabled the highly sensitive determination of terpenic acids, aleuritic acid, several minor fatty ...
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