Search Results
Results 501 - 550 of 1132
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Piñeros Miguel A - - 2002
Al-induced release of Al-chelating ligands (primarily organic acids) into the rhizosphere from the root apex has been identified as a major Al tolerance mechanism in a number of plant species. In the present study, we conducted physiological investigations to study the spatial and temporal characteristics of Al-activated root organic acid ...
Jena Bhabani S - - 2002
Organic acids in fresh leaves, fruits, and dried rinds of Garcinia cowa (G. cowa) were determined by high-performance liquid chromatography. Fresh leaves, fruits, and dried rinds were extracted with water at 120 degrees C for 20-30 min under 15 lbs/in(2) pressure. Also, dried rinds were extracted with solvents (acetone and ...
Choi Man Yee - - 2002
Water-soluble organic compounds have recently received much attention because of their ability to absorb water and alter the hygroscopic properties of inorganic aerosols. The effects of glycerol, succinic acid, malonic acid, citric acid, and glutaric acid on the water cycles (water activities during particle evaporation and growth), crystallization relative humidities ...
Travers Susan P - - 2002
The present experiment investigated Fos-like immunoreactivity (FLI) in the nucleus of the solitary tract (NST) after intraoral infusions of 0.1 M citric acid, 0.3 M NaCl, and 0.3-30 mM quinine monohydrochloride (QHCl) in awake, behaving rats. Increases in QHCl concentration produced increases in the numbers of FLI-labeled neurons in the ...
Hem Stanley L - - 2002
In vitro dissolution experiments although perhaps not at typical body concentrations and temperatures demonstrated that the alpha-hydroxycarboxylic acids present in interstitial fluid (citric acid, lactic acid, and malic acid) are capable of dissolving aluminum-containing adjuvants. Amorphous aluminum phosphate adjuvant dissolved more rapidly than crystalline aluminum hydroxide adjuvant. Intramuscular administration in ...
Shimada Atsumi - - 2002
Aspterric Acid, 6-Hydroxymellein, Arabidopsis thaliana, Aspergillus terreus Aspterric acid (1) and 6-hydroxymellein (2), inhibitors of pollen development in Arabidopsis thaliana, have been isolated from the fungus Aspergillus terreus. 1 and 2 inhibited the pollen development at concentrations of 38 and 52 microM, respectively. The microscopic examination of pollen development suggested ...
Shan Xiao-Quan - - 2002
Effect of citric, malic, tartaric and acetic acids on adsorption of La, Ce, Pr and Nd by and desorption from four typical Chinese soils was studied. Generally, adsorption capacities of rare earth elements (REEs) were significantly correlated with the cation exchange capacity (CEC) of soils. In the presence of acetic ...
Jayaprakasha G K - - 2002
Organic acids in leaves and rinds of Garcinia indica (Kokam) were determined by high-performance liquid chromatography. The major organic acid in leaves and rinds has been found to be (-)-hydroxycitric acid present to the extent of 4.1-4.6 and 10.3-12.7%, respectively, by isocratic elution with 8 mM sulfuric acid as mobile ...
Fu Yuzhu - - 2002
Aspergillus niger is capable of removing dyes from an aqueous solution. In the study, the roles played by three major functional groups: carboxyl, amino and phosphate, and the lipid fraction in the biomass of A. niger in biosorption of four dyes, Basic Blue 9, Acid Blue 29, Congo Red and ...
Lee S C - - 2002
Endotheline-1 (ET-1) has been shown to enhance tachykinin-induced airway constriction. This study was designed to test whether ET-1 is involved in citric acid-induced bronchoconstriction. Forty-eight anesthetized-paralyzed guinea pigs were divided into six groups of 8 animals each: saline control; citric acid; ET-1; ET-1 + citric acid; BQ123 + ET-1 + ...
Comes Justin E - - 2002
A study was conducted to develop a preservative treatment capable of the Food and Drug Administration-mandated 5-log reduction of Escherichia coli O157:H7 populations in apple cider. Unpreserved apple cider was treated with generally recognized as safe acidulants and preservatives before inoculation with E. coli O157:H7 in test tubes and subjected ...
Peksel A - - 2002
The effect of glucose concentration on glycolytic metabolism under conditions of citric acid accumulation by Aspergillus niger was studied with 13C-labelled glucose. The results show that during cultivation at high glucose (14%, w/v), most of the label in citric acid is in C-2/C-4, and is thus due to the pyruvate ...
Beveridge T - - 2002
Sea buckthorn juice is one product that can be derived from the sea buckthorn berry, a new alternative crop for the Canadian western provinces. Fresh pressed juice separates into three phases when allowed to stand overnight in the refrigerator: an upper cream phase, juice in the middle portion, and a ...
Gent Janneane F - - 2002
Chlorhexidine, a bitter bis-biguanide antiseptic, is the only known blocker of the human salty taste. In order to characterize the effects of chlorhexidine on stimulus identification, taste confusion matrix (TCM) performance was measured for subjects treated with 1.34 mM chlorhexidine gluconate (n = 9) and water controls (n = 9). ...
Charlwood Joanne - - 2002
The regionally specific structure and function of the kidney renders it susceptible to toxic exposure. To characterize these changes at the proteome level, we have investigated the effects on protein expression following treatment with gentamicin. The more than 20 proteins identified were involved in the citric acid cycle, gluconeogenesis, fatty ...
Papanikolaou S - - 2002
AIMS: To study the biochemical response of Yarrowia lipolytica LGAM S(7)1 during growth on raw glycerol (the main by-product of bio-diesel production units) in order to produce metabolic products of industrial significance. METHODS AND RESULTS:Yarrowia lipolytica was cultivated on raw glycerol or glucose in flasks. Although nitrogen-limited media were employed, ...
Saguir F M - - 2002
AIMS: The purpose of this work was to study the effect of L-malic and/or citric acids on Oenococcus oeni m growth in deficient nutritional conditions, and their roles as possible biosynthetic precursors of the essential amino acids. METHODS AND RESULTS: Bacterial cultures were performed in synthetic media. Bacterial growth rate ...
Chen Avril R M - - 2002
Incubation of stemodin (1) in cultures of Aspergillus niger ATCC 9142 resulted in the production of 2alpha,3beta,13-trihydroxystemodane (2), 2alpha,7beta,13-trihydroxystemodane (3) and 2alpha,13,16beta-trihydroxystemodane (4), while stemodinone (5) afforded 13,18-dihydroxystemodan-2-one (6) and 13,16beta-dihydroxystemodan-2-one (7). Four novel metabolites were obtained from the bioconversion of stemarin (8) by the fungus, namely 18-hydroxystemaran-19-oic acid (9), ...
Haznedaro─člu F - - 2001
The effect of tetracycline hydrochloride as an endodontic irrigant on smear layer removal was examined by scanning electron microscopy and compared with bidistilled water, 2.5% sodium hypochlorite (NaOCl), and 50% citric acid in 20 extracted teeth. Five teeth, as a control, were irrigated with bidistilled water only in group 1. ...
Peng C - - 2001
The role of water-soluble organic compounds on the hygroscopic properties of atmospheric aerosols has recently been the subject of many studies. In particular, low molecular weight dicarboxylic acids and some multifunctional organic acids have been found or are expected to exist in atmospheric aerosols in urban, semiurban, rural, and remote ...
Kubo A - - 2001
Chlamydiae contain two porins, MOMP and PorB, that facilitate diffusion of solutes through the outer membrane. MOMP is a general porin that permits the diffusion of a wide variety of compounds including carbohydrates and amino acids. The relative inefficiency of PorB as a general porin and its low abundance in ...
DeMars C S - - 2001
We present a case that illustrates the acute (<6 hours) metabolic and hemodynamic effects of the ingestion of a massive oral citric acid load. The principal findings included metabolic acidosis accompanied by an increase in the plasma anion gap that was not caused by L -lactic acidosis, hyperkalemia, and the ...
Kolosova N - - 2001
Emission of methyl benzoate, one of the most abundant scent compounds of bee-pollinated snapdragon flowers, occurs in a rhythmic manner, with maximum emission during the day, and coincides with the foraging activity of bumblebees. Rhythmic emission of methyl benzoate displays a "free-running" cycle in the absence of environmental cues (in ...
Mojet J - - 2001
Detection thresholds for NaCl, KCl, sucrose, aspartame, acetic acid, citric acid, caffeine, quinine HCl, monosodium glutamate (MSG) and inosine 5'-monophosphate (IMP) were assessed in 21 young (19-33 years) and 21 elderly (60-75 years) persons by taking the average of six ascending two-alternative forced choice tests. A significant overall effect was ...
Nuijen B - - 2001
Kahalalide F is a novel antitumor agent isolated from the marine mollusk Elysia rufescens; it has shown highly selective in vitro activity against androgen-independent prostate tumors. The purpose of this study was to develop a stable parenteral formulation of kahalalide F to be used in early clinical trials. Solubility and ...
Lucas García J A - - 2001
Low molecular weight organic acids (LOAs) and fatty acids in root exudates of two lupin cultivars, Lupinus albus cv. Multolupa and L. luteus cv. Tremosilla, were determined at flowering and fruiting stages. LOAs were analysed by capillary electrophoresis. Acetic and citric acids were the most abundant, especially the latter in ...
West N X - - 2001
The reported incidence of tooth erosion caused by acidic soft drinks has been increasingly documented. Citric and phosphoric acids are the two main dietary acids present in these soft drinks. Many variables need to be determined in order to assess risk factors for dental erosion caused by beverage consumption including ...
Rehnberg A S - - 2001
BACKGROUND: Helicobacter pylori is recognized as the main etiological factor for chronic gastritis, peptic ulcer and possibly also gastric malignancies. A 14C-urea breath test was successively refined to correctly diagnose the presence of H. pylori. METHODS: After intake of a 14C-urea cocktail, 14CO2 in breath was trapped in benzethoniumhydroxide/ethanol. Serology ...
Crolla A - - 2001
Currently, the majority of worldwide microbial production of citric acid utilizes Aspergillus niger in a carbohydrate based submerged fermentation. Due to their high carbon content, hydrocarbons also have the potential of producing high concentrations of citric acid. Initial lab experiments conducted using 1875 ml batch fermentations with n-paraffin found that ...
Tsai C J - - 2001
This paper compares the collection efficiency and capacity of a coated porous metal disk with those of a silica gel tube and an impinger at the acid or basic aerosol concentration of two times the permissible exposure limitation (Taiwan IOSH, Institute of Occupational Safety and Health), relative humidity of 80 ...
Yoon J J - - 2001
Biodegradable polymeric scaffolds for tissue engineering were fabricated by a gas-foaming/salt-leaching method using a combination of two effervescent salts, ammonium bicarbonate and citric acid. Poly(D,L-lactic-co-glycolic acid) (PLGA) in a state of gel-like paste was first produced by precipitation of PLGA dissolved in chloroform into ethanol. The polymer slurry was mixed ...
Di Renzo M - - 2001
Acids are used to modify the structure and composition of dentin surfaces to improve bonds formed with resins. The purpose of this work is to investigate such chemical modifications using the surface-sensitive technique photoacoustic Fourier transform infrared spectroscopy (PA-FTIRS). Spectra of acid-treated samples (citric, maleic, nitric, and phosphoric at pH ...
Ivanov I E - - 2001
Experiments for treatment of contaminated broiler litter with citric, tartaric and salicylic acids were performed. At days 2 and 6 after the treatment, pH values (using a pH-meter), the ammonia concentrations (titration with 0.1 N HCl) and the microbial cells counts were determined in both experimental and control specimens of ...
Doi Y - - 2001
A cement powder consisting of sodium calcium phosphate, Na3Ca6(PO4)5, in addition to tetracalcium phosphate and beta-tricalcium phosphate was prepared by pulverizing blocks of 4 wt% sodium-, 11 wt% carbonate-containing apatite samples that were heated at 1700 degrees C for 5 h. When mixed with 30 wt% malic acid or citric ...
Zdráhal Z - - 2001
Three unknown di- and tricarboxylic acids were characterized in the fine size fraction of aerosols which were collected during the wet season in the Amazon basin (Rondonia, Brazil). For the structural characterization of the methyl esters of these unknown compounds, mass spectrometry with electron ionization (EI) and tandem mass spectral ...
Maaheimo H - - 2001
Aerobic and anaerobic central metabolism of Saccharomyces cerevisiae cells was explored in batch cultures on a minimal medium containing glucose as the sole carbon source, using biosynthetic fractional (13)C labeling of proteinogenic amino acids. This allowed, firstly, unravelling of the network of active central pathways in cytosol and mitochondria, secondly, ...
Strang J - - 2001
Recent reports of the use of lemon juice in the preparation of heroin for injection have failed to recognize the importance of the different forms of heroin (in the form of the salt or the base) and the impact of this on the chemical manipulation required before injection. One hundred ...
Timpawat S - - 2001
Glass-ionomer root canal sealer is commonly used because of its chemical bonding and favorable physical characteristics when bonding to dentin. This study was designed to determine the tensile bond strength of a glass-ionomer sealer (Ketac Endo, Espe, Seefeld, Germany) on root canal walls after pretreatment with different conditioners. Flat inner ...
Calzuola I - - 2001
Citric acid whose structure is comparable to that of small acidic peptides, can bind to DNA in the presence of divalent cations (Cu2+, Fe2+, Zn2+, Mg2+). Citrate-DNA interaction occurs also in a cell homogenate and in this experimental model too requires the presence of natural divalent cations. In fact the ...
Antonucci S - - 2001
This experimental study reports about production selectivity in the fermentation of glucose to citric acid by Yarrowia lipolytica as a function of substrate concentration. Batch runs featuring biomass growth and one or two citric acid production phases were carried out in a 15-l stirred tank fermentor. The presented results demonstrate ...
Aoyagi K - - 2001
BACKGROUND: We propose that reactive oxygen and argininosuccinic acid (ASA) form guanidinosuccinic acid (GSA). An alternative to this hypothesis is the so-called guanidine cycle, which consists of a series of hydroxyurea derivatives that serve as intermediates in a pathway leading from urea to GSA. We compare the role of the ...
Breslin P A - - 2001
Chronic rinsing with chlorhexidine, an oral-antiseptic, has been shown to decrease the saltiness of NaCl and the bitterness of quinine. The effect of acute chlorhexidine on taste has not been investigated. The purpose of the present study was to examine the effect of acute chlorhexidine rinses on taste intensity and ...
Saavedra L - - 2001
Fruit juices have very distinct organic acid profiles that can be used as fingerprints for establishing possible adulteration. Recently, our group developed and validated a capillary electrophoresis method using UV detection for determining citric, isocitric, tartaric, and malic acids in natural and commercial orange juices. Sample treatment consisted of only ...
Futamura T - - 2001
In a culture of Aspergillus oryzae MK-107-39 in a 3-l airlift bioreactor, kojic acid was not produced when glucose/wheat germ medium (GM1) was used. However, when a jar fermentor was used, the kojic acid yield was high. A suitable medium for culture in an airlift bioreactor consisting of partially hydrolyzed ...
Babay N - - 2001
This study evaluated, in vitro, fibroblast attachment to periodontally involved root surfaces which were either root planed or acid/chelated by different agents. Specimens were divided into 3 groups of 12 specimens each. The root surfaces were root planed with a Gracey 7/8 curette, an EMS or an Amdent piezo-electric scaler ...
Fiume Z - - 2001
Malic Acid functions in cosmetic formulations as a pH adjuster, and Sodium Malate functions as a skin conditioning agent-humectant. Malic Acid is reportedly used in almost 50 cosmetic formulations across a range of product types at low concentrations, whereas Sodium Malate is used in only one. As a pH adjuster, ...
Dubeski C V - - 2001
Lab-scale sequencing batch reactors were used to treat chemithermomechanical pulping wastewater that had chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in the range of 5,980-8,990 mg/L, and 2,240-3,190 mg/L, respectively. A cycle time of 24 hour, with a hydraulic retention time of 34.3 hours was used. With 1 ...
Monni S - - 2001
Chlorophyll, organic (citric and malic acids) and abscisic acid (ABA) contents and stem water potential were measured to indicate possible physiological effects of heavy metal deposition on Empetrum nigrum L. (crowberry). The leaves and stems of E. nigrum were collected at distances of 0.5 and 8 km from the Cu-Ni ...
Karaffa L - - 2001
Fungi, in particular Aspergilli, are well known for their potential to overproduce a variety of organic acids. These microorganisms have an intrinsic ability to accumulate these substances and it is generally believed that this provides the fungi with an ecological advantage, since they grow rather well at pH 3 to ...
Moreaux B - - 2000
The effect of ammonia on the cough response to citric acid and on substance P release from C-fibers involved in this reflex was assessed. For a period from one to four days, piglets were exposed, in an inhalation chamber, to ammonia at a concentration of 15 or 30 ppm. During ...
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