bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical aspects of analysis of Micrococcus luteus, Neisseria cinerea, and Pseudomonas fluorescens by means of capillary electrophoresis
Authors: Hoerr Verena , Stich August , Holzgrabe Ulrike 
Published: October 2004

AbstractWithin the frame of our study we investigated Microccocus luteus, Neisseria cinerea, and Pseudomonas fluorescens by means of capillary zone electrophoresis (CZE). They form chains and clusters on a different scale, which can be reflected in the electropherograms. A low buffer concentration of Tris‐borate and Na2 EDTA containing a polymeric matrix of 0.0125% poly(ethylene) oxide (PEO) was used. Key factors were the standardization and optimization of CE conditions, buffer solution, and pretreatment of bacterial samples, which are not transferable to different bacterial strains, in general. The different compositions of the cell wall of on the one hand Gram‐positive (M. luteus) and Gram‐negative (N. cinerea) cocci and on the other hand Gram‐negative, rod‐shaped bacteria (P. fluorescens), are probably responsible for the different pretreatment conditions.
Separation of isomers of acyl glucuronides using micellar electrokinetic capillary chromatography in dynamically coated capillaries
Authors: Hansen Steen H. , Christiansen Ida 
Published: October 2004

AbstractThe acyl glucuronide metabolites of endogenous as well as of xenobiotic compounds may undergo isomerization in vitro as well as in the human body. The parent acyl glucuronide and the isomerization products may react with endogenous protein to form products which in worst cases may act as antigens and thus create an allergic response. In the present paper new methods based on micellar electrokinetic or microemulsion electrokinetic chromatography for the separation of all isomerization products as well as the hydrolysis product of acyl glucuronides are described. In order to perform the separation at lower pH values in a reasonable time dynamically coated capillaries were used. This enables the electroosmotic flow to be high and constant even at low pH. The methods were developed using S‐naproxen‐β‐1‐O‐acyl glucuronide as the model substance. The assignment of the single peaks in the electropherogram was performed tentatively based on the sequential appearance of the isomerization products with time.
Analysis of insecticidal proteins from Bacillus thuringiensis and recombinant Escherichia coli by capillary electrokinetic chromatography
Authors: Luong John H. T. , Male Keith B. , Mazza Alberto , Masson Luke , Brousseau Roland 
Published: October 2004

AbstractBacillus thuringiensis and recombinant Escherichia coli proteinaceous protoxins were subject to proteolysis and analyzed by capillary electrokinetic chromatography. Three resulting toxins (65 kDa) were baseline‐resolved within 22 min using a 10 mM borate, pH 11 separation buffer consisting of 25 mM sodium dodecyl sulfate (SDS) and 30 mM phytic acid. The toxins displayed differential interactions with the SDS and phytic acid phases to effect their separation. The ion‐pairing interaction between the analyte and phytic acid was also useful in preventing adsorption to the capillary walls and thus enhanced separation resolution and efficiency. The use of electrokinetic chromatography allows achievement of the separation in a significantly shorter time than conventional high‐performance liquid chromatography (HPLC) using a diethylaminoethyl (DEAE) weak‐anion exchanger.
Multiple sample amplification and genotyping integrated on a single electronic microarray
Authors: Huang Ying , Shirajian Jack , Schroder Astrid , Yao Zuxu , Summers Tamara , Hodko Dalibor , Sosnowski Ron 
Published: October 2004

AbstractWe report a novel method that allows simultaneous in situ amplification and then genotyping of single nucleotide polymorphism (SNP) for multiple samples on a single electronic microarray. The locus coding for one of the common inherited thrombosis risk factors, Factor V Leiden (FVL), was chosen as a model system for SNP analysis. This method combines strand displacement amplification (SDA) with electrophoretic movement and concentration of DNA on electronic microarrays to provide a single platform for DNA amplification and analysis. The method includes: electronic anchoring of allele‐specific SDA amplifiable primers (APs) and a nonamplifiable primer (NAP) to different electrodes, electronic hybridization of genomic DNA from different samples to those primers, in situ amplification of target DNA, and genotyping of FVL. Compared to previous anchored SDA methods, the addition of a NAP improves detection signals by at least 20‐fold. The sensitivity of this method is dependent on the amplification time. Using this method, nine different genomic DNA samples with known FVL genotypes were amplified and correctly genotyped on a single electronic microarray without any contamination between samples. The present method could streamline development of nucleic acid‐based assays in applications of molecular diagnostic, point‐of‐care testing, and forensic detection, which often require the capability to analyze multiple samples efficiently.
Drying of Tribenuron, a Thermosensitive Biochemical
Authors: Chen B.‐K. 
Published: October 2004

AbstractThe extension of microwave use in the biochemical industry was explored by drying tribenuron, a thermosensitive biochemical, in a microwave oven and in a thermal vacuum oven. Tribenuron wet cakes, containing a mixture of solvents, methanol and water, were heated at 40 °C in both ovens. Nitrogen purge was used to prevent the decomposition of tribenuron from prolonged heating. Microwave heating dried tribenuron in twenty minutes while the vacuum oven heating required eighteen hours to dry the wet cakes. In addition, the tribenuron quality was maintained under microwave drying, but deteriorated in the thermal vacuum oven. Therefore, microwave technology is more effective in drying tribenuron than conventional vacuum ovens. The results of this study are important for the use of microwave drying on a large scale in biochemical companies.
Optimization of Operating Temperature for Continuous Immobilized Glucose Isomerase Reactor with Pseudo Linear Kinetics
Authors: Faqir N.M. 
Published: October 2004

AbstractIn this work, the optimal operating temperature for the enzymatic isomerization of glucose to fructose using a continuous immobilized glucose isomerase packed bed reactor is studied. This optimization problem describing the performance of such reactor is based on reversible pseudo linear kinetics and is expressed in terms of a recycle ratio. The thermal deactivation of the enzyme as well as the substrate protection during the reactor operation is considered. The formulation of the problem is expressed in terms of maximization of the productivity of fructose. This constrained nonlinear optimization problem is solved using the disjoint policy of the calculus of variations. Accordingly, this method of solution transforms the nonlinear optimization problem into a system of two coupled nonlinear ordinary differential equations (ODEs) of the initial value type, one equation for the operating temperature profile and the other one for the enzyme activity. The ODE for the operating temperature profile is dependent on the recycle ratio, operating time period, and the reactor residence time as well as the kinetics of the reaction and enzyme deactivation. The optimal initial operating temperature is selected by solving the ODEs system by maximizing the fructose productivity. This results into an unconstrained one‐dimensional optimization problem with simple bounds on the operating temperature. Depending on the limits of the recycle ratio, which represents either a plug flow or a mixed flow reactor, it is found that the optimal temperature of operation is characterized by an increasing temperature profile. For higher residence time and low operating periods the residual enzyme activity in the mixed flow reactor is higher than that for the plug flow reactor, which in turn allows the mixed flow reactor to operate at lower temperature than that of the plug flow reactor. At long operating times and short residence time, the operating temperature profiles are almost the same for both reactors. This could be attributed to the effect of substrate protection on the enzyme stability, which is almost the same for both reactors. Improvement in the fructose productivity for both types of reactors is achieved when compared to the constant optimum temperature of operation. The improvement in the fructose productivity for the plug flow reactor is significant in comparison with the mixed flow reactor.
An Empiric Steady State Model of Lactate Production in Continuous Fermentation with Total Cell Retention
Authors: Richter K. , Nottelmann S. 
Published: October 2004

AbstractContinuous lactic acid fermentation with total cell recycling was carried out with the strain Lactobacillus paracasei ATB 160111 in a membrane reactor system. The aim of this study was to examine the dependence of lactic acid production and cell mass formation on the hydraulic dilution rate, D, and the availability of both yeast extract and peptone in a modified glucose medium. An experimental design was used and experimental data were obtained, which could be fitted by sigmoidal equations with a high accuracy within the parameter ranges investigated of 0.1 h–1 ≤ D ≤ 0.5 h–1 and 2.5 g/L ≤ peptone/yeast extract ≤ 50 g/L. A steady‐state lactate concentration was established in all tests and a maximum lactate productivity of 26 g/(L × h) was reached at a dilution rate of 0.5 h–1 and a nutrient concentration of 15 g/L. Increasing the concentrations of peptone and yeast extract beyond a value of 15.9 g/L did not lead to an increase in productivity, although total cell mass was accumulated up to 200 g/L. Further examinations showed that only a certain part of the biomass was always active and balanced cell growth was clearly not limited by the lack of any nutrient component in the medium, however, it was affected strongly by product inhibition. A significant decrease in lactic acid yield occurred when the biomass concentration exceeded a value of about 80 g/L. The empiric models used in this study allowed the performance behavior of different strains, for which no biologically well‐founded data are yet known, to be compared. Whether empirical sigmoidal models can be also used for the description of process states in continuous fermentation processes should also be looked into.
Extractive Synthesis of Ethyl‐Oleate Using Alginate Gel Co‐Entrapped Yeast Cells and Lipase Enzyme
Authors: Kiss M.A. , Sefanovits‐Bányai É. , Tóth Á. , Boross L. 
Published: October 2004

AbstractTo synthesize ethyl‐oleate ester, a complex Ca‐alginate gel co‐entrapped system was prepared. The gel beads contained two kinds of biocatalysts (living yeast cells and a lipase enzyme) and various amounts of glucose (100–400 g/L). These alginate beads dispersed directly in pure oleic acid. To follow the bioconversion of the cell growth, the glucose uptake of yeast cells, the concentration of ethanol inside the gel beads and the ethyl‐oleate concentration in oleic acid phase was monitored. The glucose was quantitatively taken up by yeast cells during 24–72 h, depending on the concentration of glucose. After this 24–72‐hour period, the glucose uptake was stopped. In accordance with changes in glucose concentration, the concentration of ethanol and ethyl‐oleate increased rapidly during the first day of fermentation and thereafter slowed down. It is supposed that the inhibitory effect of produced ethanol would be resolved by co‐immobilization of lipase in the same gel particles. Using lipase, one is able to transform ethanol to ethyl‐oleate, which is soluble in oleic acid. According to the data obtained a minimum of 4 U/mL lipase is required to increase ethyl‐oleate production significantly. Summing up it can be concluded that by means of this system a maximum yield of ethanol and ethyl‐oleate was achieved when gel beads containing 100 g/L glucose and 4 U/mL lipase enzyme were used.
Microbial Processes of Heavy Metal Removal from Carbon‐Deficient Effluents in Constructed Wetlands
Authors: Kosolapov D.B. , Kuschk P. , Vainshtein M.B. , Vatsourina A.V. , Wießner A. , Kästner M. , Müller R.A. 
Published: October 2004

AbstractThis paper reviews the main microbial processes involved when toxic metals are removed from wastewater in constructed wetlands. Microbial activity is thought to play a key role in the detoxification of these metals. The paper concentrates on the microbial processes which affect the mobility, the toxicity and bioavailability of metals, namely biosorption, metal sulfide precipitation by sulfate reducers, redox transformations, and methylation, as well as microbe‐plant interactions. These reactions result in either the precipitation and accumulation of metals in wetland soils, or their volatilization and emission into the atmosphere. The possibilities of optimizing the microbially mediated reactions for the development of wetland technology are discussed as a long‐term metal retention strategy.
Chromosomal imbalances detected by array comparative genomic hybridization in human oligodendrogliomas and mixed oligoastrocytomas
Authors: Kitange Gaspar , Misra Anjan , Law Mark , Passe Sandra , Kollmeyer Thomas M. , Maurer Matthew , Ballman Karla , Feuerstein Burt G. , Jenkins Robert B. 
Published: October 2004

AbstractLoss of heterozygosity and fluorescence in situ hybridization (FISH) studies have shown that deletions of 1p and 19q are highly prevalent in oligodendroglioma. However, these tumors have not been comprehensively screened for other alterations in chromosomal dosage. In this study, we used array‐based comparative genomic hybridization (CGHa) of mapped BAC DNA to screen for such alterations in 31 oligodendrogliomas (20 grade II, 9 grade III, and 2 grade IV) and 4 mixed oligoastrocytomas (1 grade I, 1 grade II, and 2 grade IV). The most frequent aberrations were loss of 1p (17 cases; 49%) and 19q (15 cases; 43%) and combined loss of 1p/19q (13 cases; 37%). In addition, deletion of 4q, 5p, 9p, 10q, 11p, and 13q was observed in 10, 4, 8, 4, 4, and 13 cases, respectively; loss of whole chromosomes 4, 9, and 13 in 4, 1, and 7 cases, respectively; gain of 7p, 8q, 10p, and 11q in 6, 6, 5, and 10 cases, respectively, and gain of whole chromosomes 7 and 11 in 2 patients each. Minimally altered regions detected by CGHa involved chromosome bands 1p36.32, 4q33, 5p15, 8q24, 11p15, and 19q13.3. Univariate analysis of all 35 cases suggested that combined deletion of 1p and 19q is associated with better survival (P= 0.03). In addition, 8q gain in the oligodendrogliomas was strongly associated with poor outcome (P= 0.002). Also associated with poor disease outcome were alterations that had low prevalence in the pure oligodendrogliomas, including loss of 3q, 9q, and 12q and gain of 1p, 8p, and 10q. In summary, in oligodendrogliomas, CGHa was able to detect novel small alterations in chromosomal dosage that had not been previously detected by other methods. In addition, our findings support the hypotheses that oligodendroglioma can be classified into several groups by CGHa analysis and that specific alterations in genetic dosage may have biologic or clinical significance. © 2004 Wiley‐Liss, Inc.
Genomic instability in multiple myeloma: Evidence for jumping segmental duplications of chromosome arm 1q
Authors: Sawyer Jeffrey R. , Tricot Guido , Lukacs Janet L. , Binz Regina Lichti , Tian Erming , Barlogie Bart , Shaughnessy John 
Published: October 2004

AbstractMultiple myeloma (MM) is a malignant plasma cell disorder characterized by complex karyotypes and chromosome 1 instability at the cytogenetic level. Chromosome 1 instability generally involves partial duplications, whole‐arm translocations, or jumping translocations of 1q, identified by G‐banding. To characterize this instability further, we performed spectral karyotyping and fluorescence in situ hybridization with probes for satII/III (1q12), BCL9 (1q21), and IL6R (1q21) on the karyotypes of 44 patients with known 1q aberrations. In eight patients, segmental duplication of 1q12–21 and adjacent bands occurred on nonhomologous chromosomes. In five cases, the 1q first jumped to a nonhomologous chromosome, after which the 1q12–21 segment again duplicated itself 1–3 times. In three other cases, segmental duplications occurred after the 1q first jumped to a nonhomologous chromosome, where the proximal adjacent nonhomologous chromosome segment was duplicated prior to the 1q jumping or inserting itself into a new location. These cases demonstrate that satII/III DNA sequences are not only associated not only with the duplication of adjacent distal chromosome segments after translocation, but are also associated with the duplication and jumping/insertion of proximal nonhomologous chromosome segments. We have designated this type of instability as a jumping segmental duplication. © 2004 Wiley‐Liss, Inc.
IL‐1‐regulated responses in astrocytes: Relevance to injury and recovery
Authors: John Gareth R. , Lee Sunhee C. , Song Xianyuan , Rivieccio Mark , Brosnan Celia F. 
Published: October 2004

AbstractIn the central nervous system (CNS), the cellular processes of astrocytes make intimate contact with essentially all areas of the brain. They have also been shown to be functionally coupled to neurons, oligodendrocytes, and other astrocytes via both contact‐dependent and non‐contact‐dependent pathways. These observations have led to the suggestion that a major function of astrocytes in the CNS is to maintain the homeostatic environment, thus promoting the proper functioning of the neuronal network. Inflammation in the CNS disrupts this process either transiently or permanently and, as such, is thought to be tightly regulated by both astrocytes and microglia. The remarkable role that single cytokines, such as TNF and IL‐1, may play in this process has now been well accepted, but the extent of the reprogramming of the transcriptional machinery initiated by these factors remains to be fully appreciated. With the advent of microarray technology, a more comprehensive analysis of this process is now available. In this report we review data obtained with this technology to provide an overview of the extent of changes induced in astrocytes by the cytokine IL‐1. © 2004 Wiley‐Liss, Inc.
The cytokine IL‐1β transiently enhances P2X7 receptor expression and function in human astrocytes
Authors: Narcisse Leontine , Scemes Eliana , Zhao Yongmei , Lee Sunhee C. , Brosnan Celia F. 
Published: October 2004

AbstractExtracellular nucleotide di‐ and triphosphates such as ATP and ADP mediate their effects through purinergic P2 receptors belonging to either the metabotropic P2Y or the ionotropic P2X receptor family. The P2X7R is a unique member of the P2X family, which forms a pore in response to ligand stimulation, regulating cell permeability, cytokine release, and/or apoptosis. This receptor is also unique in that its affinity for the ligand benzoyl‐benzoyl ATP (BzATP) is at least 10‐fold greater than that of ATP. Primary human fetal astrocytes in culture express low‐levels of P2X7R mRNA and protein, and BzATP induces only a slight influx in intracellular calcium [Ca2+]i, with little demonstrable effect on gene expression or pore formation in these cells. We now show that, following treatment with the proinflammatory cytokine IL‐1β, BzATP induces a robust rise in [Ca2+]i with agonist and antagonist profiles indicative of the P2X7R. IL‐1β also induced the formation of membrane pores as evidenced by the uptake of YO‐PRO‐1 (375 Da). Quantitative real‐time PCR demonstrated transient upregulation of P2X7R mRNA in IL‐1β‐treated cells, while FACS analysis indicated a similar upregulation of P2X7R protein at the cell membrane. In multiple sclerosis lesions, immunoreactivity for the P2X7R was demonstrated on reactive astrocytes in autopsy brain tissues. In turn, P2X7R stimulation increased the production of IL‐1‐induced nitric oxide synthase activity by astrocytes in culture. These studies suggest that signaling via the P2X7R may modulate the astrocytic response to inflammation in the human central nervous system. © 2004 Wiley‐Liss, Inc.
Experimental study on heat and fluid flow in LNG tank heated from the bottom and the sidewalls
Authors: Kanazawa Takuya , Kudo Kazuhiko , Kuroda Akiyoshi , Tsui Nobuhiko 
Published: October 2004

AbstractHeat and fluid flow in a layer heated from the bottom and the sidewalls simulating an underground LNG tank is experimentally studied under high Rayleigh number (7.5×1010<Ra<1.5×1013) conditions by electrochemical mass transfer technique. The experiment yielded the following results. When sidewalls are heated, the heat transfer along the bottom surface is reduced. Heat transfer along sidewalls is independent of bottom heating, and is modeled by an equation for laminar natural convection flow even for Ra>109. Convective flow pattern in the tank is visualized by the Schlieren technique. The results, combined with local mass transfer measurement, show that Sh of the bottom surface is reduced in the area where impinging downward flow exists. It is caused by the suppression of thermal plume formation by the downward flow. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(7): 417–430, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20031
Ectopic bone formation using osteogenic protein‐1 carried by a solution precipitated hydroxyapatite
Authors: Zhang Renwen , Xu Dazhong , Landeryou Tracy , Toth Carol , Dimaano Nena , Berry Jenny , Evans Julie , Hawkins Monica 
Published: October 2004

AbstractSolution precipitation of calcium and phosphate is a technique to generate hydroxyapatite [Peri‐Apatite™ (PA), Stryker Orthopaedics, Mahwah, NJ] on metal substrate. This study was carried out to determine the capacity of PA to adsorb osteogenic protein‐1 (OP‐1) and the time course of release, and to determine the osteoinductive activity of OP‐1. The adsorption and release studies were conducted with 125I‐labeled OP‐1– and PA‐coated titanium alloy disks. The results indicate that the adsorption of OP‐1 on the PA‐coated disks is linear with the concentration of OP‐1 up to 5 mg/mL. There is an initial release of 75% to 80% of adsorbed OP‐1 within the first hour, and 92% of OP‐1 is released in 3 days. The osteoinductive activity of OP‐1 was determined in the rat intramuscular ectopic bone formation assay. A total of 24 titanium alloy disks were evenly divided into 3 groups with different treatments for implantation, plain disks (group A), disks coated with PA (group B), and disks coated with PA plus 40 μg OP‐1 (group C). Osteogenic protein‐1, 40 μg in solution, was injected into the muscle pouch in animals of group D (n = 8). The rats were sacrificed 3 weeks postoperatively and the implants were retrieved. Ectopic bone formation was evaluated with radiography and histology. Results demonstrated that OP‐1 induced ectopic bone in all the animals of group C and group D. The titanium alloy disks were surrounded by trabecular bone and marrow tissue. None of the animals of group A or group B showed any evidence of osteoinduction. Our findings indicate that PA can deliver OP‐1 directly to titanium alloy implants and maintain the osteoinductive activity of OP‐1. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 412–418, 2004