bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial Reduction of Sulfur Dioxide with Anaerobically Digested Municipal Sewage Biosolids as Electron Donors
Authors: Selvaraj Punjai T. , Sublette Kerry L. 
Published: March 2005

AbstractA concentrated stream of sulfur dioxide (SO2) is produced by regeneration of the sorbent in certain new regenerable processes for the desulfurization of flue gas. We have previously proposed that this SO2 can be converted to elemental sulfur for disposal or byproduct recovery using a microbial/Claus process. In this process, two‐thirds of the SO2‐reducing gas stream would be contacted with a mixed culture containing sulfate‐reducing bacteria (SRB), where SO2 would act as an electron acceptor with reduction to hydrogen sulfide (H2S). This H2S could then be recombined with the remaining SO2 and sent to a Claus unit to produce elemental sulfur. The sulfate‐reducing bacterium, Desulfouibrio desulfuricans, has been immobilized by coculture with flocforming heterotrophs from an anaerobic digester, resulting in a SO2‐reducing floc that may be collected from the effluent of a continuous reactor for recycle by gravity sedimentation. The carbon and energy source for these cultures was anaerobically digested municipal sewage solids. The maximum specific activity for SO2 reduction in these cultures, in terms of dry weight of D. desulfuricans biomass, was 9.1 mmol of SO2/h. g. The stoichiometry with respect to the electron donor was 15.5 mg of soluble COD/mmol of SO2 reduced.
Biotreatment of Refinery Spent Sulfidic Caustics
Authors: Rajganesh B. , Sublette K. L. , Camp C. , Richardson M. R. 
Published: March 2005

AbstractCaustics are used in petroleum refining to remove hydrogen sulfide from various hydrocarbon streams. Spent sulfidic caustics from two Conoco refineries have been successfully biotreated on a bench scale, resulting in neutralization and removal of active sulfides. Sulfides were completely oxidized to sulfate by Thiobacillus denitrificans. Microbial oxidation of sulfide produced acid, which at least partially neutralized the caustic.
Hydrodynamics and Mass Transfer in a Four‐Phase External Loop Air Lift Bioreactor
Authors: Sajc Lidija , Obradovic Bojana , Vukovic Dragoljub , Bugarski Branko , Grubisic Dragan , Vunjak‐Novakovic Gordana 
Published: March 2005

AbstractAn external loop air lift reactor (ELALR) was developed and designed for continuous production and extraction of extracellular secondary metabolites by immobilized Frangula alnus Mill. plant cells. This system was considered as a four‐phase system, with dispersed gas, nonaqueous liquid solvent, and calcium alginate particles in water or Murashige and Skoog medium. Analysis of the four‐phase ELALR revealed the influence of gas, solvent, calcium alginate particles and MS medium composition on gas and solvent holdup, liquid circulation velocity, mixing in aqueous liquid phase, and mass transfer coefficients of oxygen and plant cell product. It was shown that the gas holdup appears to be the principal variable determining the properties of the four‐phase system. An unified correlation for the gas holdup, based on drift flux flow in a three‐phase system, has been extended to the four‐phase system. Bubble size and bubble size distribution observed in the bubbly flow regime were the same in water as in the MS medium system (Sauter mean diameter 2.5 mm). Consequently, gas holdup and all related parameters, such as liquid circulation velocity, oxygen mass transfer coefficient, and axial liquid dispersion in MS medium, were similar to those in water for the four‐phase system.
Continuous Enantioselective Transesterification in Organic Solvents. Use of Suspended Lipase Preparations in a Microfiltration Membrane Reactor
Authors: Indlekofer Michael , Funke Marcus , Claassen Wolfgang , Reuss Matthias 
Published: March 2005

AbstractA continuously stirred tank reactor equipped with a microfiltration membrane unit for effective retention of solid enzyme particles in organic solvent systems was constructed. A microfiltration membrane with pore size 0.1 μm based on a polypropylene matrice was used for enzyme retention and showed no loss of performance or denaturation by the organic solvent. The stereoselective transesterification reaction of (±)‐trans‐sobrerol with vinyl acetate as both acyl donor and solvent was chosen as a model system. Lipase PS from Pseudomonas sp. was used in its native form without further modification steps and remained active and highly stereoselective at 50 °C when applied to the reaction system for about 600 h of continuous operation. (‐‐)‐(1S,5R)‐sobrerolacetate and (+)‐(1R,5S)‐sobrerol could be obtained in the reactor outlet stream at approximately 48% conversion with enantiomeric excesses eeP ≈︁ 92% and eeS≈︁ 80%, respectively. Furthermore, theoretical kinetic studies showed that limitations in enantiomeric purity due to the characteristics of an ideal mixed tank may be sufficiently overcome by designing a simple two‐stage process.
Effect of Cell Concentration on the Kinetics of Whole‐Cell Enzyme Entrapped within Calcium Alginate
Authors: Lee Wen‐Chien , Lee Ru ‐Yue , Ruaan Ruoh ‐Chyu 
Published: March 2005

AbstractA method for determining the kinetics of whole‐cell enzymes entrapped within calcium alginate gel beads is presented. Diffusivities of the substrate and the product and kinetic parameters, i.e., the Michaelis constant and the maximum velocity, could be estimated by fitting experimental data to a proposed mathematical model. Immobilized cell concentration was found to be the main factor causing a decrease in maximum velocity. The influence of cell concentration in the gel beads on the variation in the maximum velocity could be isolated from the effect of cell concentration on diffusional limitation and evaluated separately. The whole‐cell enzymes became partially difficult to access by substrate when the cell population increased. The loss of enzyme accessibility resulted in a decrease in the maximum velocity and apparent initial velocity. This phenomenon of the maximum velocity varying with immobilized cell concentration has not been reported in the literature.
Cell Growth and Monoclonal Antibody Production in the Presence of Antigen and Serum
Authors: Dandulakis Gregory , Herr John C. , Kirwan Donald J. 
Published: March 2005

AbstractThe impact that the continuous presence in the fermentation broth of the cognate antigen has on the serum‐supplemented hybridoma cell cultures was investigated. Both soluble and immobilized antigen at various concentrations was applied. The cell line (ATCC TIB191) was cultured in a serum‐supplemented PFHM‐II medium in T‐flasks. Sepharose gel beads provided the immobilization matrix, and bovine γ‐globulin was the carrier protein upon which the antigen, picric acid, was conjugated. Produced antibody, after elution from the beads by displacement with free picric acid, was measured with an ELISA. Soluble antigen—carrier protein conjugates showed no effect on the cultures, but the immobilized antigen had a strong influence on them. Cell growth rate and total antibody production decreased as the amount of immobilized antigen increased from 16:10 (units are in (mol of Ag/mol of carrier):(mg of carrier/mL of beads) to 36:40. Most importantly, the specific antibody production rate switched from growth phase‐independent behavior in the antigen‐free cultures to growth phase‐dependent behavior in the immobilized antigen cultures. Furthermore, during the early stationary phase of the cultures with immobilized antigen, the specific antibody production was 20–100% higher relative to the production rate in antigen‐free cultures. This increased specific antibody production rate would be particularly useful in increasing the volumetric productivity of perfusion‐type bioreactors for hybridoma cell cultures.
Monitoring of the Biological Nutrient Removal Process by an On‐Line NAD(P)H Fluorometer
Authors: Ju Lu ‐Kwang , Xin Yang  , Lee Jaw F. , Armiger William B. 
Published: March 2005

AbstractAn on‐line NAD(P)H fluorometer has been used to investigate the fluorescence profile of a simulated anaerobic/anoxic/oxic biological nutrient removal (BNR) process and its dependency on operating parameters, such as the concentrations of organic substrate (acetate) and activated sludge. As expected from the different rates of NAD‐(P)H oxidation at different stages, the order of fluorescence levels was found to be anaerobic > anoxic > oxic. The effects of the acetate and sludge concentrations were observed most clearly at the anoxic stage: an increase in either concentration led to faster recovery of fluorescence from the drop caused by NO3− addition. A higher acetate concentration also resulted in a more significant, continuous rise in fluorescence, corresponding well with the enhanced PO43− release, at the anaerobic stage and a slower initial fluorescence decrease at the oxic stage, indicating the dependency of the decrease on substrate availability. The ratio of the two fluorescence drops caused by NO3− addition and aeration, Δ1/Δ2, obtained with the plant's sludge was found to be 0.7 × 0.1, which is similar to those of pure nitrate‐respiring cultures (e.g., Pseudomonas aeruginosa and Escherichia coli). The dominant majority of nonnitrifiers in the sludge therefore are capable of nitrate respiration, and the nitrifiers either contribute little to the overall fluorescence or perform nitrate respiration as the rest of the sludge population.
Alteration of Hybridoma Viability and Antibody Secretion in Transfectomas with Inducible Overexpression of Protein Disulfide Isomerase
Authors: Kitchin Kirsten , Flickinger Michael C. 
Published: March 2005

AbstractMonoclonal antibody (mAb)‐secreting transfectomas with dexamethasone inducible expression of the mammalian endoplasmic reticulum foldase and chaperone protein disulfide isomerase (PDI, ERp59) were generated from the murine 9.2.27 hybridoma in order to obtainin vivoevidence of whether alteration of the level of PDI, believed to be involved in immunoglobulin (Ig) assembly, results in alteration of mAb secretion kinetics. Using an RNase refolding assay, the specific activity of endogenous PDI in the 9.2.27 hybridoma was found to be constant during batch growth. An expression vector for glucocorticoid‐inducible overexpression of PDI, pMMTVPDI, was constructed from pMAMneo using a rat PDI cDNA. Cell lysates of stable transfectomas contained 2–4‐fold higher levels of PDI mRNA and increased levels of PDI protein, detected by immunoblotting, following induction with 0.1μM dexamethasone. Monoclonal antibody secretion kinetics were evaluated in 12.5 mL shake flasks, a 100 mL spinner, and a 1 L aerated batch reactor. A transfectoma was found with altered mAb secretion kinetics during cell growth following dexamethasone induction of PDI overexpression. Specific mAb secretion rate was not significantly increased following dexamethasone induction; however, hybridoma viability was sustained longer during the stationary phase of cell growth and hence total antibody yield was increased in comparison to the parent 9.2.27 hybridoma.
Simulation of Diauxic Production of Cephalosporin C by Cephalosporium acremonium: Lag Model for Fed‐Batch Fermentation
Authors: Basak Subir , Velayudhan Ajoy , Ladisch Michael R. 
Published: March 2005

AbstractWe extend a previously reported model (Chu, W. B.; Constantinides, A. Biotechnol. Bioeng. 1988, 32, 277–288) for the batch fermentation of cephalosporin C under the diauxic growth of Cephalosporium acremonium on glucose and sucrose to a fed‐batch system. For this purpose, a novel lag model is proposed for diauxie, which has two functional forms, each embodying the dependence of lag on total cell mass and secondary substrate concentration. This lag model is applicable for batch simulations for arbitrary initial glucose and sucrose concentrations. We used the previously reported batch data to perform locally optimized fed‐batch simulations. When applied to fed‐batch fermentations, multiple lag times were accounted for. These studies showed that fed‐batch fermentations (under the restriction that cell mass concentration did not exceed 25 g/L) could be more productive than simple batch runs. A representative result for a glucose‐pulse fed‐batch run at optimal cephalosporin production is a productivity of 4.22 mg of cephalosporin C/(L·h) and a production yield of 9.25 mg of cephalosporin C/g of total sugar used.
Induction of Cytochrome P‐4501A1 Activity in Response to Sublethal Stresses in Microcarrier‐Attached Hep G2 Cells
Authors: Mufti Naheed A. , Shuler Michael L. 
Published: March 2005

AbstractCell damage for cells grown on microcarriers in suspension is a critical problem for scale‐up of microcarrier reactors. In order to study cell damage as a mechanistic process, a cellular response that is more sensitive than changes in growth and death rates and would be more closely related to cell regulatory mechanisms would be advantageous. We have observed the induction of a specific cytochrome P‐450 monooxygenase, P‐450IA1 (CYP1A1), to be a sensitive method for assessing the response of microcarrier‐attached Hep G2 cells to stress resulting from hydrodynamic shear and oxygen deprivation. The kinetics of induction and amount of CYP1Al formed in response to subtle shear stress, moderate shear, and hypoxia are described. Increased stress results in increased CYP1A1 formation.
Continuous Fermentation and Stripping of Ethanol
Authors: Taylor Frank , Kurantz Michael J. , Goldberg Neil , Craig James C. 
Published: March 2005

AbstractRecycling the contents of a continuous fermentor through a stripping column is proposed as a means of reducing product inhibition and lowering the cost of fuel ethanol production. A 2‐L fermentor and 10‐cm packed column were continuously operated for 150 days without contamination. Some fouling of the packing with attached yeast cells was observed which partially blocked the column. Cell yield was lower than in a simple continuous fermentor. Complete conversion of 200 g/L glucose feed and 90% conversion of 600 g/L glucose feed were achieved. Data were analyzed by computerized process simulation. Cost analysis indicated that, with heat recovery to reduce heating and cooling costs, the continuous fermentor/stripper is possibly a lower‐cost alternative to conventional fermentation and distillation.
Porphyrin-substrate binding to murine ferrochelatase: effect on the thermal stability of the enzyme
Authors: FRANCO Ricardo , BAI Guangyue , PROSINECKI Vesna , ABRUNHOSA Filipa , FERREIRA Gloria C. , BASTOS Margarida 
Published: March 2005

Ferrochelatase (EC 4.99.1.1), the terminal enzyme of the haem biosynthetic pathway, catalyses the chelation of Fe(II) into the protoporphyrin IX ring. The energetics of the binding between murine ferrochelatase and mesoporphyrin were determined using isothermal titration calorimetry, which revealed a stoichiometry of one molecule of mesoporphyrin bound per protein monomer. The binding is strongly exothermic, with a large intrinsic enthalpy (ΔH=−97.1 kJ · mol−1), and is associated with the uptake of two protons from the buffer. This proton transfer suggests that hydrogen bonding between ferrochelatase and mesoporphyrin is a key factor in the thermodynamics of the binding reaction. Differential scanning calorimetry thermograms indicated a co-operative two-state denaturation process with a single transition temperature of 56 °C for wild-type murine ferrochelatase. An increase in the thermal stability of ferrochelatase is dependent upon mesoporphyrin binding. Similarly, murine ferrochelatase variants, in which the active site Glu-289 was replaced by either glutamine or alanine and, when purified, contained specifically-bound protoporphyrin, exhibited enhanced protein stability when compared with wild-type ferrochelatase. However, in contrast with the wild-type enzyme, the thermal denaturation of ferrochelatase variants was best described as a non-co-operative denaturation process.
Induction of human spermine oxidase SMO(PAOh1) is regulated at the levels of new mRNA synthesis, mRNA stabilization and newly synthesized protein
Authors: WANG Yanlin , HACKER Amy , MURRAY-STEWART Tracy , FLEISCHER Jennifer G. , WOSTER Patrick M. , CASERO Robert A. 
Published: March 2005

The oxidation of polyamines induced by antitumour polyamine analogues has been associated with tumour response to specific agents. The human spermine oxidase, SMO(PAOh1), is one enzyme that may play a direct role in the cellular response to the antitumour polyamine analogues. In the present study, the induction of SMO(PAOh1) enzyme activity by CPENSpm [N1-ethyl-N11-(cyclopropyl)methyl-4,8,diazaundecane] is demonstrated to be a result of newly synthesized mRNA and protein. Inhibition of new RNA synthesis by actinomycin D inhibits both the appearance of SMO(PAOh1) mRNA and enzyme activity. Similarly, inhibition of newly synthesized protein with cycloheximide prevents analogue-induced enzyme activity. Half-life determinations indicate that stabilization of SMO(PAOh1) protein does not play a significant role in analogue-induced activity. However, half-life experiments using actinomycin D indicate that CPENSpm treatment not only increases mRNA expression, but also leads to a significant increase in mRNA half-life (17.1 and 8.8 h for CPENSpm-treated cells and control respectively). Using reporter constructs encompassing the SMO(PAOh1) promoter region, a 30–90% increase in transcription is observed after exposure to CPENSpm. The present results are consistent with the hypothesis that analogue-induced expression of SMO(PAOh1) is a result of increased transcription and stabilization of SMO(PAOh1) mRNA, leading to increased protein production and enzyme activity. These data indicate that the major level of control of SMO(PAOh1) expression in response to polyamine analogues exposure is at the level of mRNA.
Tie Lines and Activities in the System CoO─MgO─SiO2 at 1373 K
Authors: Jacob K. T. , Mukhopadhyay Sukanya , Shukla A. K. 
Published: March 2005

The tie lines between (CoXMg1−X)O solid solution with rock salt structure and orthosilicate solid solution (CoYMg1−Y)‐Si0.5O2, and between orthosilicate and metasilicate (CoZMg1‐Z)SiO3 crystalline solutions, have been determined experimentally at 1373 K. The compositions of coexisting phases have been determined by electron probe microanalysis (EPMA) and lattice parameter measurement on equilibrated samples. The metasilicate solid solution exists only for 0 > Z > 0.213. The activity of CoO in the rock salt solid solution was determined as a function of composition and temperature in the range of 1023 to 1373 K using a solid‐state galvanic cell:Pt, (CoXMg1−X)O+Co|(Y2O3)ZrO2|Co+CoO, PtThe free energy of mixing of (CoXMg1−X)O crystalline solution can be expressed by the equationΔGE=X(1 −X)[(6048 − 2.146T)X+ (8745 − 3.09T)(1 −X)] J·mol−1The thermodynamic data for the rock salt phase is combined with information on interphase partitioning of Co and Mg to generate the mixing properties for the ortho‐ and metasilicate solid solutions. For the orthosilicate solution (CoYMg1 −Y)Si0.5O2 at 1373 K, the excess Gibbs free energy of mixing is given by the relationΔGE=Y(1 −Y)[2805Y+ 3261(1 −Y)] J·mol−1For the metasilicate solution (CoZMg1 −Z)SiO3 at the same temperature, the excess free energy can be expressed by the relationΔGE=Z(1 −Z)[2570Z+ 3627(1 −Z)] J·mol−1
FOURIER ANALYSIS OF X‐RAY PATTERNS OF VITREOUS SiO2 AND B2O3*
Authors: Warren B. E. , Krutter H. , Morningstar O. 
Published: March 2005

ABSTRACTThe X‐ray scattering curves for vitreous SiO2 and B2O3 are obtained in a vacuum camera, using monochromatic Mo and Cu radiation. A Fourier analysis of the scattering curve gives directly a curve representing the distribution of neighboring atoms about any one atom. For SiO2, the distribution curve establishes difinitely the tetrahedral silicon‐oxygen network. The distribution curve for B2O3 indicates a triangular coördination, each boron surrounded by three oxygens, and each oxygen shared between two borons. The interatomic distances which are found are in good agreement with the values found in crystalline silicates and borates. The importance of the new Fourier method of analysis of glass diffraction patterns is emphasized by the fact that the distribution curves which are obtained are unique, no assumptions as to structure being involved.
Benign symmetric lipomatosis (Launois–Bensaude syndrome)
Authors: Fernández‐Vozmediano José , Armario‐Hita José 
Published: March 2005

A 37‐year‐old woman with a personal history of appendicectomy, cholecystectomy, left oophorectomy secondary to an ovarian cyst complication, nephritic colic with repeated episodes of pyelonephritis, alcoholic hepatopathy, Raynaud's phenomenon and bilateral exophthalmos showed an increase in volume in the root of the upper limbs and in the base of the neck over a period of 4 years, painful to the touch and of a soft consistency. She presented with a pseudo‐athletic appearance (Fig. 1) produced by an increase in the volume at the root of the upper limbs, upper back and the back of the neck (Fig. 2). The lesions produced a pulling sensation and were associated with paresthesia, hyperesthesia, and a moderate loss of strength in both arms. A biopsy taken from the upper third of the right arm showed a diffuse proliferation of the subcutaneous adipose tissue, which appeared normal, and extended between the collagen fibers, reaching in some cases into the most superficial zones of the reticular dermis (Fig. 3). Laboratory evaluation revealed a chronic anemia, leukopenia with moderate lymphopenia, increased erythrocyte sedimentation rate, elevation of enzymes of hepatic function, decrease in total proteins, and increase in ferritin, all in the context of hepatopathy. Antinuclear antibodies and the hormonal profile were normal. Abdominal and gynecologic echography revealed a right ovarian cyst of no clinical relevance. Cranial nuclear magnetic resonance (NMR) revealed an increase in the periorbital fat responsible for bilateral exophthalmos.Pseudo‐athletic appearance produced by the increase in volume at the root of the upper limbsimageIncreased volume in the upper back and the back of the neckimageDiffuse proliferation of subcutaneous cellular tissue, with normal and mature cellularity, infiltrating through the collagen fibers (Hematoxiline/Eosine ×100)image
THE USES OF NATIONAL BALANCE SHEETS
Authors: Goldsmith R. W. 
Published: March 2005

The now urgent problem in the field is to translate into practice the theoretical agreement, slowly reached over the past two decades, on the need for and feasibility of sectorized national balance sheets.The paper discusses the five main uses of national balance sheets, viz. (1) the study of the relations among assets and liabilities at one point of time in one country, particularly the position of financial institutions; (2) the analysis of changes in one country's financial structure between several balance sheet dates; (3) the comparison of balance sheet structure at one date among two or more countries; (4) the comparison of the financial development of several countries for at least two but usually more numerous balance sheet dates; and (5) the use of selected balance sheet items, e.g., reproducible tangible assets or liquid financial assets, in econometric models.Examples are presented of the first three uses, viz. for (1) an eleven sector balance sheet matrix for the U.S. as of the end of 1962; for (2) an unsectored national balance sheet of the U.S. in 1900, 1912, 1929, 1939, 1945 and 1958; and for (3) a comparison of condensed unsectored national balance sheets for a dozen countries (USA, UK, France, Germany, Belgium, Norway, Italy, Japan, Israel, Mexico, India and the USSR) for a date in the neighborhood of 1960.