bluuebunny/crossref_metadata_2025_split huggingface dataset:
On‐line monitoring of the viscosity in dextran fermentation using piezoelectric quartz crystal
Authors: Endo Hideaki , Sode Koji , Karube Isao , Muramatsu Hiroshi 
Published: May 2005

AbstractA novel viscous sensor utilizing AT‐cut quartz crystal to monitor the viscosity of fermentation broth was developed. The sensor system was constructed from the piezoelectric quartz crystal fixed to the cell, exposing only one side of the quartz crystal electrode, an oscillating circuit, a peak level meter, and a personal computer. In order to investigate the characteristics of the sensor system, a sensor signal relating to the resonant resistance of the quartz crystal was measured using dextran solutions with different molecular weights. The linear relationship was obtained between the sensor signal and the (ρη)1/2 of the liquid, where ρ and η are the density and viscosity, respectively. The sensor signal was dependent not only on the viscosity of the liquid but also on the molecular weight of dextran, because dextran solution shows a non‐Newtonian property. The sensor system was applied for the on‐line monitoring of the viscosity in dextran fermentation. A good correlation was observed between the sensor signal and the viscosity value measured with a rotational viscometer for the fermentation broth. Little bubbling effect and agitation of the sensor signal were observed, showing that this system can be utilized for viscosity monitoring in a bioprocess.
Influence of whey protein on continuous acidogenic degradation of lactose
Authors: Kisaalita W. S. , Lo K. V. , Pinder K. L. 
Published: May 2005

AbstractIn previous studies on the acidogenic phase of anaerobic fermentation of lactose, a pathway for the reaction and a rate equation have been proposed. The question then remained as to the effect of the protein in whole whey on the mechanism and on the overall organic substrate conversion. In this study, it was found that as much as 70% of the protein was broken down in the acidogenic reactor. Radiotracer tests showed that the inclusion of protein had no effect on the reaction pathway for lactose degradation. Thus, the whole sweet cheese whey can be fermented as efficiently as whey from which the protein has been removed.
Ethanol production in a microporous hollow‐fiber‐based extractive fermentor with immobilized yeast
Authors: Kang Whankoo , Shukla Rajesh , Sirkar K. K. 
Published: May 2005

AbstractMicroporous‐membrane‐based extractive product recovery in product‐inhibited fermentations allows in situ recovery of inhibitory products in a nondispersive fashion. A tubular bioreactor with continuous strands of hydrophobic microporous hollow fibers having extracting solvent flowing in fiber lumen was utilized for yeast fermentation of glucose to ethanol. Yeast was effectively immobilized on the shell side in small lengths of chopped microporous hyrophilic hollow fibers. The beneficial effects of in situ dispersion‐free solvent ex (oleyl alcohol and dibutyl phthalate) were demonstrated for a 300 g/L glucose substrate feed. Outlet glucose concentration dropped drastically from 123 to 41 g/L as solvent/ substrate flow ratio was increased from 0 to 3 at 9 mL/h of substrate flow rate with oleyl alcohol as extracting solvent. The significant productivity increase with in situ solvent extraction became more evident as solvent/ substrate flow ratio increased. A model of the locally integrated extractive bioreactor describes the observed fermentor performance quite well.
Ethanol production from starch in a pervaporation membrane bioreactor using Clostridium thermohydrosulfuricum
Authors: Mori Yutaka , Inaba Toshiharu 
Published: May 2005

AbstractTo attain both high productivity and efficient recovery of ethanol from broth, a membrane bioreactor consisting of a jar fermentor and a pervaporation system was applied to the direct production of ethanol from uncooked starch with a thermophilic anaerobic bacterium, Clostridium thermohydrosulfuricum. From four types of ethanol‐selective membranes tested, microporous polytetrafluoroethylene (PTFE) membrane, the pores of which are impregnated with silicone rubber, was chosen for its large flux, high ethanol selectivity, and high stability. During fed‐batch fermentation with pervaporation in the membrane bioreactor, ethanol was continuously extracted and concentrated in two traps with concentrations at 5.6%–6.2% (w/w) in trap 1 (20 °C) and 27%–32% (w/w) in trap 2 (liquid N2), while the ethanol concentration in the broth was maintained at 0.85–0.9% (w/w). Due to the low ethanol concentration in the broth, and the immobilization of bacterial cells by the membrane, the number of viable cells, and, eventually, the ethanol productivity, increased in the membrane bioreactor.
A rapid and sensitive method for measurement of leukotrienes based on HPLC
Authors: Odlander Björn , Claesson Hans‐Erik 
Published: May 2005

AbstractA rapid and sensitive method for simultaneous detection of leukotriene (LT) B4, LTC4, LTD4, LTE4, 5S,12S‐dihydroxy‐eicosatetraenoic acid, 6‐trans LTB4, 12‐epi‐6‐trans LTB4 and the ω‐metabolites of LTB4 has been developed. Leukocyte incubations were terminated by the addition of one volume of methanol, and the mixture was centrifuged. Analysis was then directly performed by reverse phase high performance liquid chromatography on a column packed with 3 μm Nucleosil C18 guarded by a precolumn. Quantitation of eluted compounds was carried out by UV‐monitoring at 280 nm and integration of the elution profile. The sensitivity of the method was approximately 1 ng for both LTB4 and LTC4. Accuracy was 101.6% (SD ± 9.8%) for LTB4 and 99.9% (SD ± 8.7%) for LTC4 in the interval 5–160 ng.
Comparison of iodinated [Nle15]‐ and [Met15]‐gastrin17 prepared by reversed‐phase HPLC
Authors: Seet Lin , Fabri Louis , Nice Edouard C. , Baldwin Graham S. 
Published: May 2005

Abstract125I‐[Nle15]‐gastrin17 prepared by the iodogen method can be separated by reversed‐phase high performance liquid chromatography into two peaks, both of which elute after [Nle15]‐gastrin17. Direct determination of the specific activities of the two derivatives by microbore reversed‐phase HPLC indicated that they were the mono‐ and di‐iodinated species. In contrast the two peaks obtained with [Met15]‐gastrin17 iodinated under the same conditions eluted earlier, relative to the appropriate gastrin17 standard, than the [Nle15]‐gastrin derivatives. Treatment of either peak with 0.75 M dithiothreitol at 56°C or 95°C resulted in progressive conversion to compounds migrating in relative positions similar to the 125I‐[Nle15]‐gastrin17 derivatives. Direct determination of the specific activity of the earlier eluting [Met15]‐gastrin17 derivative before reduction indicated that it was the mono‐iodinated species. It thus appears likely that iodination of [Met15]‐gastrin17 by the iodogen method results predominantly in the formation of mono‐ and di‐125I‐[Met sulphoxide15]‐gastrin17. To avoid problems arising from oxidation of the methionine residue of gastrin during iodination, the use of 125I‐[Nle15]‐gastrin17 in binding studies is therefore recommended.
Determination of the enantiomeric purity of scopolamine isolated from plant extract using achiral/chiral coupled column chromatography
Authors: Stalcup Apryll M. , Faulkner James R. , Tang Yubing , Armstrong Daniel W. , Levy Luis W. , Regalado Edmundo 
Published: May 2005

AbstractThe optical purity of scopolamine derived from Datura sanguinea was determined using coupled column chromatography. A C18 column was used to separate scopolamine from the additional alkaloids and other biological material present in the vegetal extract. The C18 column was coupled through a six‐port switching valve to two β‐cyclodextrin columns in series which were used to resolve the scopolamine enantiomers. A single acetylated β‐cyclodextrin column gives equivalent results to the native cyclodextrin columns because of slightly higher enantioselectivity for scopolamine. A multistep extraction procedure is used to isolate scopolamine from the vegetal material. 4–6% of the scopolamine in the final extract was found to be the d enantiomer. Sample extracts as well as commercial scopolamine hydrobromide were treated under various conditions commonly encountered during typical commercial extraction procedures and analyzed in order to determine if the d enantiomer was present in the original material or if it was produced during the extraction process and, if so, determine which step and conditions contribute to acemization. Both the salt and the extract were found to be susceptible to racemization under basic conditions (≥pH 9) although the extract appeared to be more susceptible than the salt. Tropic acid formed from the hydrolysis of scopolamine seemed to be completely racemized even though the remaining scopolamine was only partially racemized. Within experimental error, no d enantiomer was found in the original fresh plant material.
High performance liquid chromatographic determination of theophylline metabolites in human liver microsomes
Authors: Sarkar Mohamadi A. , Karnes H. Thomas 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) technique for the determination of three metabolites of theophylline, 3‐methylxanthine (3‐MX), 1‐methylxanthine (1‐MX) and 1,3‐dimethyluric acid (1,3‐DMU) in human liver microsomes is described. The analytes were extracted from human liver microsomes with methylene chloride/isopropanol and stepwise gradient elution was employed for the resolution of peaks. The limits of quantitation were 15 ng/mL for 3‐MX, 20 ng/mL for 1‐MX and 20 ng/mL for 1,3‐DMU. The calibration range was linear for the three metabolites and the calibration ranges were 15–250 ng/mL for 3‐MX, 20–250 ng/mL for 1‐MX and 250–4000 ng/mL for 1,3‐DMU. The absolute recovery ranged from 63–84% for 3‐MX, 65–79% for 1‐MX and 77–89% for 1,3‐DMU over the calibration curve range. Accuracy for all three metabolites was within ± 10% and adequate seletivity was demonstrated by the lack of interfering peaks in blank chromatograms. The within‐run and interday precision were within 10% RSD for all three metabolites tested at two concentrations. The advantage of this method over previous methods is that the use of quaternary ammonium ion pair reagents in the mobile phase has been obviated. Also, unlike a previous radiometric HPLC method, the need for radiolabelled theophylline has also been eliminated. The method was used to characterize theophylline metasbolism in human liver microsomes for immunoinhibition studies and to investigate the interaction of theophylline with selected quinolone antibiotitics.
Evaluation of peroxyoxalate chemiluminescence postcolumn detection of fluphenazine in urine and blood plasma using high performance liquid chromatography
Authors: Mann B. , Grayeski M. L. 
Published: May 2005

AbstractPeroxyoxalate chemiluminescence may be used for sensitive postcolumn detection of phenothiazine analytes separated by high performance liquid chromatography with appropriate optimization of measurement conditions such as solvent, pH and oxalate ester. Detectability of fluorescent analytes by chemical excitation varies greatly, but analytes with low oxidation potentials are generally more readily detected at low levels, as demonstrated for phenothiazines, an important class of fluorescent drugs. Some improvement in detection limits is observed for fluphenazine when chemiluminescence detection is compared to conventional fluorescence detection. Because of the specificity of chemical excitation, fewer interferences from fluorescent impurities in a urine matrix are observed.
Selective determination of secondary amines as their N‐diethylthiophosphoryl derivatives by gas chromatography with flame photometric detection
Authors: Kataoka Hiroyuki , Eda Michiko , Makita Masami 
Published: May 2005

AbstractA selective and sensitive method has been developed for the determination of secondary amines by gas chromatography (GC). After removal of primary amines by the reaction with o‐phthaldialdehyde, secondary amines were converted into their N‐diethylthiophosphoryl derivatives and then measured by GC with flame photometric detection using a DB‐1701 capillary column. The derivatives were sufficiently volatile and stable to give single symmetrical peaks. The detection limits of secondary amines were ca. 0.05‐0.2 pmol per injection. N‐Methylcyclohexylamine was used as an internal standard. The calibration curves for secondary amines in the range 1–20 nmol were linear and sufficiently reproducible for quantitative determination. This method was successfully applied to small urine samples without prior clean‐up. Overall recoveries of secondary amines added to urine samples were 91–105%. By using this method, secondary amines in urine samples could be analysed without any influence from primary amines and other coexisting substances. The analytical results of secondary amine content in urine samples of normal subjects are presented.
Selective detection of terminally α 2–3 and α 2–6 sialylated neolacto‐series gangliosides by immunostaining on thin layer chromatograms
Authors: Müthing Johannes , Neumann Ulrich 
Published: May 2005

AbstractA method for selective detection of terminally α 2–3 and α 2–6 sialylated neolacto‐series gangliosides has been developed. The procedure involves separation of gangliosides on high performance thin layer chromatography plates, fixation of the silica gel, treatment with Vibrio cholerae neuraminidase and incubation of the plates with nLcOse4 Cer‐specific antibodies. Alkaline phosphatase‐conjugated second antibodies were used to visualize bound first antibodies by generating a blue dye from 5‐bromo‐4‐chloro‐3‐indolyl phosphate. Neolacto‐series gangliosides from human granulocytes with terminally α 2–3 and α 2–6 linked N‐acetylneuraminic acid served as examples. Neuraminidase treatment of gangliosides with α 2–3 substituted sialic acid is necessary prior to immunostaining whereas α 2–6 sialylated gangliosides can be detected without enzyme treatment. Steric hindrance of sialic acid bound in position 3 to terminal galactose prevented binding of the antibody to the Galβ1‐4GlcNAc sequence whereas sialylation in position 6 to terminal galactose does not hinder recognition. The procedure is viable for the detection of amounts down to 10 ng of gangliosides. This method should be useful to screen gangliosides from different tissues or cell lines for the presence of such components, especially if only small quantities of material are available.
Assay of vitamin B6 in human plasma with graphitic carbon column
Authors: Kurioka Susumu , Ishioka Noriaki , Sato Junko , Nakamura Junta , Ohkubo Tatuo , Matsuda Makoto 
Published: May 2005

AbstractA high performance liquid chromatographic (HPLC) procedure for measuring pyridoxal‐5′‐phosphate (PLP) and certain forms of B6 vitamers in plasma is presented here. This HPLC procedure consisted of a single graphitic carbon column with a fluorescence detector employing an isocratic eluent (15% acetonitrile:1% perchloric acid: 0.05% sodium bisulfite). The graphitic carbon column is useful in acidic eluent without deteriorization. The relatively low fluorescent intensity of PLP under acidic conditions is improved by its derivatization with bisulfite in the eluent during chromatographic separation. Using this procedure, the detection limit of PLP is 50 fmol, and an aliquot of 5–50 μL of human plasma is required giving satisfactorily precise results within 5 min. We applied this method to the determination of PLP and certain B6 vitamers in human plasma after oral supplementation of pyridoxine.
Lipid peroxidation and covalent binding in the early functional impairment of liver golgi apparatus by carbon tetrachloride
Authors: Poli G. , Cottalasso D. , Pronzato M. A. , Chiarpotto E. , Biasi F. , Corongiu F. P. , Marinari U. M. , Nanni G. , Dianzani M. U. 
Published: May 2005

AbstractThe onset of the lipoprotein secretory block provoked by CCl4 in the whole animal was monitored after purification of liver Golgi membranes. Both lipid transit through the apparatus the apparatus and hexosylation of the lipoprotein are markedly inhibited 5–15 min after poisoning. Pre‐treating the animal with alpha‐tocopherol, shown to prevent lipid peroxidation without modifying the covalent binding due to CCl4 metabolites, affords little protection against lipid accumulation in the Golgi, but total preservation of galactosyl transferase activity. While haloalkylation therefore appears to be the major mechanism of damage in the early phases of CCl4‐induced derangement of lipid secretion, lipid peroxidation is probably more involved later, this is indicated by the marked, though never complete, protection against fatty liver afforded at 24 h after CCl4 poisoning by supplementation of the membrane with alpha‐tocopherol.
Fructose‐1, 6‐diphosphate as an in vitro and in vivo anti‐alcohol agent in the rat
Authors: Galzigna L. , Bianchi M. , Rizzoli V. , Scuri R. , Giannetti P. , Paesano A. 
Published: May 2005

AbstractFructose‐1, 6‐diphosphate (FDP) decreases the effect of ethanol on Ca++ entry and inhibits the ethanol‐stimulated phosphate efflux in rat heart slices. FDP also inhibits the ethanol‐stimulated [36Cl−]‐uptake by rat brain microvesicles and affects the isolated GABA‐receptor in a way opposite to that of ethanol. The in vivo effects of FDP include a dose‐dependent decrease in ethanol‐induced gastric ulcers and a decrease in the serum transaminase levels raised by chronic ethanol administration. Other central actions of ethanol such as diuresis, narcosis, dependence and withdrawal symptoms are also counteracted by FDP.
Modulation of phenotypic expression of fibroblasts by alteration of the cytoskeleton
Authors: Evangelisti R. , Becchetti E. , Baroni T. , Rossi L. , Arena N. , Valeno V. , Carinci P. , Locci P. 
Published: May 2005

AbstractSeveral studies indicate that the cytoskeleton may be involved in modulating the cellular response to environmental signals. We have studied the role of the cytoskeleton in regulating glycosaminoglycan (GAG) synthesis and secretion, hyaluronate (HA) endocytosis, the activities of hexoglycosidases, protein synthesis and secretion. Fibroblasts were treated with colchicine (1–8 μM) and nocodazole (1 or 4 μM) to alter microtubules or cytochalasin B (0·5–4 μM) to alter microfilaments. Colchicine inhibited GAG synthesis and secretion in a concentration‐dependent manner. It reduced protein and sulphated GAG secretion, while HA secretion was not affected. Concentration‐dependent disruption of microtubules from the periphery toward the cellular centre with nocodazole inhibited only the secretion of GAG. Centrosomal microtubles appeared to be required to promote GAG synthesis; intact microtubules promoted the transport of secretory products, intercompatmental transport of lysosomal enzymes and lysosome maturation, but not protein synthesis and HA secretion. Cytochalasin B treatment inhibited, in a concentration‐dependent manner, the synthesis and secretion of GAGs and proteins, and the endocytosis of HA. Intact microfilament mesh‐works appeared to be required to promote synthesis and secretion of proteins and proteoglycans and to contribute to the transmembrane control of receptor‐mediated endocytosis. Drug treatment of concanvalin A (Con A)‐stimulated fibroblasts inhibited the stimulation of GAG synthesis. It is probable that this effect may result, in part, from drug‐induced effects on Con A‐mediated endocytosis.
Mechanism of citrinin‐induced dysfunction of mitochondria. IV—Effect on Ca2+ transport
Authors: Chagas Generoso M. , Oliveira Ma. Benigna M. , Campello Annibal P. , Kluppel Ma. Lucia W. 
Published: May 2005

AbstractThe effect of citrinin on Ca2+ transport was studied in isolated kidney cortex and liver mitochondria, and baby hamster kidney cultured cells. The mycotoxin significantly inhibited the activity of 2‐oxoglutarate and pyruvate dehydrogenases in both kidney cortex and liver mitochondria. Citrinin promoted a decrease in the velocity and in the total capacity of Ca2+ uptake, in both mitochondria. Apparently, citrinin acts by a mechanism similar to ruthenium red. In intact cultured cells, citrinin also had a preferential effect on mitochondrial Ca2+ fluxes. Citrinin promoted a marked decrease in the Ca2+ level in the mitochondrial matrix, whereas that of the extramitochondiral fraction became less affected. All the observed effects were dependent on the citrinin concentration.
Examining large databases: A chemometric approach using principal component analysis
Authors: Meglen Robert R. 
Published: May 2005

AbstractPrincipal component analysis is used to examine large multivariate databases. The graphical approach to exploratory data analysis is described and illustrated with a single example of chemical composition data obtained on environmental dust particles. While the graphical approach to exploratory data analysis has certain advantages over the numerical procedures, the empirical approach described here should be viewed as complementary to the more robust treatments that statistical methodologies afford.
Simultaneous analysis of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) by spectrophotometry and the Kalman filter
Authors: Shi Leming , Li Zhiliang , Xu Zhihong , Pan Zhongxiao , Wang Leshan 
Published: May 2005

AbstractThis paper describes the simultaneous determination of cobalt, nickel, copper, zinc and cadmium by spectrophotometry and the Kalman filter method. Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) react with 5‐bromo‐2‐(2‐pyridylazo)‐5‐diethylaminophenol (5‐Br‐PADAP) in the presence of cationic surfactant cetyl pyridinium bromide (CPB) to form five different coloured ternary complexes. The absorption curves of these complexes overlap severely in the scanning range 500–620 nm. The Kalman filter algorithm is successfully applied to resolve the overlapped absorption curves and therefore makes the simultaneous determination of these metallic ions possible without tedious pretreatment. The proposed method is applied to analyse the titled elements in synthetic samples and in environmental samples such as hair, fingernail and river water samples with satisfactory results.
Ein verbessertes Huygens‐Manometer
Authors: Schreiner H. , Klein R. , Zürrer E. 
Published: May 2005

AbstractBeim einseitig geschlossenen Huygens‐Manometer konnte bisher keine lineare Abhängigkeit zwischen Druck‐ und Skalenteilen erreicht werden. Durch Anbringen eines Birnengeräßes am Kapillarende wurde das Manometer soweit verbessert, daß man eine völlig lineare Eichkurve erhält.
Technische und wirtschaftliche Möglichkeiten der Kohlenoxyd‐Hydrierung
Authors: Tramm E. h. Heinrich 
Published: May 2005

AbstractBerichtet wird über wesentliche Fortschritte der Fischer‐Tropsch‐Synthese mit festangeordnetem Katalysator. Die Entwicklung hochaktiver Eisen‐Katalysatoren und Aufklärung wichtiger Fragen der Reaktionskinetik und des Wärmetransportes in den Reaktoren ermöglichte erhebliche Erhöhung der Ausbeute und Qualität der Produkte und technische Verbesserung der Synthese‐Anlagen, so daß die Wirtschaftlichkeit des Fischer‐Tropsch‐Prozesses unter sehr verschiedenartigen Bedingungen gegeben ist. Erstmalig werden zusammenfassende Mitteilungen über die Qualität der aus diesen Produkten von der Ruhrchemie großtechnisch hergestellten synthetischen Schmieröle gemacht.
Lichtstarkes Meßverfahren für Sedimentations‐, Elektrophorese‐ und Diffusionsversuche Ein Gerät zur Messung der Diffusionskonstanten
Authors: Antweiler H. J. 
Published: May 2005

AbstractZur Untersuchung von Sedimentations‐, Elektrophorese‐ und Diffusionsvorgängen wurde ein lichtstarkes Meßverfahren nach der Interferenzmethode entwickelt, das den Vorteil der hohen Lichtstärke einer Jaminschen Anordnung des Planparallelplatten ‐ Interferometers gegenüber dem Doppelspalt‐Interferometer voll ausnutzt, indem als optisches Zusatzglied zwei gewinkelte gleichdicke Planparallelplatten angefügt werden. Ein Gerät zur Messung der Diffusionskonstanten wird beschrieben.