bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of surface domains on magnetization of very soft magnetic ribbons
Authors: Sabolek S. , Babić E. , Posedel D. , Šušak M. 
Published: March 2005

AbstractThe influence of surface fields Hp (generated by core currents) on the parameters of M–H loops (the coercive field Hc, the maximum magnetization Mm, etc.) of amorphous and nanocrystalline Fe73.5Cu1Nb3Si15.5B7 ribbon and amorphous VITROVAC 6025Z ribbon has been investigated. In amorphous Fe73.5Cu1Nb3Si15.5B7 ribbon Hc decreases with Hp with unchanged Mm, whereas in nanocrystalline Fe73.5Cu1Nb3Si15.5B7 and VITROVAC 6025Z ribbons Hc increases with Hp and Mm decreases with Hp. This unusual increase of Hc with Hp is ascribed to the influence of Hp on the surface domain structure (SDS) and strong interaction between SDS and inner (main) domain structure (MDS) in these materials. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Annealing effect on the electrical activity of extended defects in plastically deformed p‐Si with low dislocation density
Authors: Feklisova O. V. , Pichaud B. , Yakimov E. B. 
Published: March 2005

AbstractIt is shown that after plastic deformation in clean conditions the most efficient recombination defects in Si are dislocation trails. The DLTS spectrum associated with the defects in the dislocation trails in p‐Si are revealed. The thermal annealing effect on the electrical properties of these extended defects has been studied. A complex annealing kinetics of defects in the dislocation trails is revealed by the EBIC and DLTS. It is shown that annealing at 800 °C essentially decreases the EBIC contrast of dislocation trails. The DLTS spectrum associated with dislocation trails is also found to disappear after such annealing. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phenology and life cycle of the annual, Chamaesyce maculata (L.) Small (Euphorbiaceae), with multiple overlapping generations in Japan
Authors: Suzuki Nobuhiko , Teranishi Shin 
Published: March 2005

AbstractThe phenology of germination, vegetative growth and sexual reproduction in the annual Chamaesyce maculata (L.) Small (Euphorbiaceae) were investigated in a natural population in western Japan. Seedlings emerged from mid‐June to early October, with three peaks: mid‐June, late July and late August. Plants that emerged in June commenced sexual reproduction from late July, and thereafter both vegetative growth and sexual reproduction occurred together until early November, the plants showing no switching from vegetative growth to sexual reproduction. Seedlings that emerged in June and July suffered high mortality, but most seedlings that emerged from August onward survived until the reproductive stage. The minimum size for reproduction was largest for plants that emerged early in the season, and it decreased with a delay in seedling emergence. The late emergence of seedlings that resulted in low reproductive output may be to some extent compensated for by the increased probability of survival in the seedling stage. A transplant experiment clarified that C. maculata can repeat a maximum of three overlapping generations within a year. Multiple generations per year were attained by non‐dormant seeds produced in the first and second generations and clearly resulted in an increased reproductive output per year. The life cycle with multiple overlapping generations may have been acquired in habitats where unpredictable disturbance results in temporally unsuitable conditions for germination, vegetative growth and sexual reproduction of annual plants, but where suitable conditions frequently continue over a period longer than the single generation time of annual plants.
Involving the community in cervical cancer prevention programs
Authors: Agurto I. , Arrossi S. , White S. , Coffey P. , Dzuba I. , Bingham A. , Bradley J. , Lewis R. 
Published: March 2005

AbstractUnderutilization of cervical cancer prevention services by women in the high‐risk age group of 30–60 years can be attributed to health service factors (such as poor availability, poor accessibility, and poor quality of care provided), to women's lack of information, and to cultural and behavioral barriers. The Alliance for Cervical Cancer Prevention (ACCP) partners have been working to identify effective ways to increase women's voluntary participation in prevention programs by testing strategies of community involvement in developing countries. The ACCP experiences include developing community partnerships to listen to and learn from the community, thereby enhancing appropriateness of services; developing culturally appropriate messages and educational materials; making access to high‐quality screening services easier; and identifying effective ways to encourage women and their partners to complete diagnosis and treatment regimens. Cervical cancer prevention programs that use these strategies are more likely to increase demand, ensure follow‐through for treatment, and ultimately reduce disease burden.
EFFECTS OF CUTTING ON THE NITROGEN ECONOMY AND DRY MATTER YIELD OF LABLAB GROWN UNDER MONOCULTURE AND INTERCROPPED WITH MAIZE IN NORTHERN THAILAND
Authors: DEVKOTA N. R. , RERKASEM B. 
Published: March 2005

A study was conducted to examine the effects of the time and severity of cutting lablab (Lablab purpureus), both in sole crops and intercropped with maize (Zea mays). The effects of cutting management on the dry matter (DM) yield, leaf area index (LAI), nodulation, the nitrogen (N) yield, and N fixation by lablab were measured, as were the total DM yield, grain yield, and a yield component of maize.Two dates of lablab cutting (40 and 60 d after sowing (DAS)), and two heights of cutting (30 and 20 cm above the soil surface) were applied in factorial combinations as well as a no-cutting treatment. Maize was not cut either in monoculture or intercrops.Intercropping lablab with maize increased the grain yields of maize from 3.2 t ha−1 to 3.8 t ha−1 if lablab was cut at 40 DAS, but delaying cutting until 60 DAS had no effect, while uncut lablab reduced the yield of maize by 10%. Intercropping lablab with maize reduced the total N yield of lablab by over 50%, from 302 to 132 kg N ha−1. Regardless of cropping system, the total N yield of lablab at 130 DAS was 24% less when lablab was cut at 60 DAS compared with 40 DAS. Cutting height did not significantly affect the total N yield of lablab. Although both cropping system and cutting time significantly affected the total N fixation by lablab at 130 DAS, there were no significant effects of cropping system, cutting time or severity of cutting on the proportion of N in lablab derived from N fixation.Values of Land Equivalent Ratio (LER) which ranged between 1.2 and 1.6, and of Area Time Equivalent Ratio (ATER) which ranged between 1.0 and 1.4 for intercrops of maize with lablab indicated a definite advantage of intercropping. LER and ATER values were greatest when lablab was uncut, and least when lablab was cut at 60 DAS.
Effect of Inclusion Body Production on Culture Turbidity and Cell Dry Weight in Growing Bacterial Cultures
Authors: Hwang Soon Ook , Feldberg Ross S. 
Published: March 2005

AbstractAn approach to the optimization of product yield in an inducible inclusion body‐producing system is presented. Following induction by indoleacrylic acid (IAA) of a trpLEHIVgp41 fusion protein, we found a large increase in culture turbidity and single‐cell dry weight. After an initial transition phase, new and constant values for specific growth rate, single‐cell light turbidity, and single cell dry weight were achieved, allowing for the determination of optimal conditions for product formation.
Genetic Engineering of Structural Protein Polymers
Authors: Cappello Joseph , Crissman John , Dorman Mary , Mikolajczak Marcia , Textor Garret , Marquet Magda , Ferrari Franco 
Published: March 2005

AbstractGenetic and protein engineering are components of a new polymer chemistry that provide the tools for producing macromolecular polyamide copolymers of diversity and precision far beyond the current capabilities of synthetic polymer chemistry. The genetic machinery allows molecular control of chemical and physical chain properties. Nature utilizes this control to formulate protein polymers into materials with extraordinary mechanical properties, such as the strength and toughness of silk and the elasticity and resilience of mammalian elastin. The properties of these materials have been attributed to the presence of short repeating oligopeptide sequences contained in the proteins, fibroin, and elastin. We have produced homoblock protein polymers consisting exclusively of silk‐like crystalline blocks and elastin‐like flexible blocks. We have demonstrated that each homoblock polymer as produced by microbial fermentation exhibits measurable properties of crystallinity and elasticity. Additionally, we have produced alternating block copolymers of various amounts of silk‐like and elastin‐like blocks, ranging from a ratio of 1:4 to 2:1, respectively. The crystallinity of each copolymer varies with the amount of crystalline block interruptions. The production of fiber materials with custom‐engineered mechanical properties is a potential outcome of this technology.
Long‐Term in Vitro Function of Adult Hepatocytes in a Collagen Sandwich Configuration
Authors: Dunn James C. Y. , Tompkins Ronald G. , Yarmush Martin L. 
Published: March 2005

AbstractIn an effort to reconstruct the cellular polarity normally found in the liver, adult rat hepatocytes were sandwiched between two layers of hydrated rat tail tendon collagen matrix. Functionally, sandwiched hepatocytes maintained the secretion of albumin, transferrin, fibrinogen, bile acids, and urea for at least 6 weeks, whereas cells cultured on a single layer of collagen gel ceased such secretion in 1–2 weeks. After 1 week of culture on a single layer of collagen gel, hepatocytes could still recover these lost functions when a second layer of collagen gel was applied. The exact nature of the substrate for constructing the sandwich system appeared to be unimportant as long as it allowed cellular attachment. Hepatocytes cultured in the sandwich system appeared to maintain a distribution of actin filaments similar to the in vivo state, whereas cells cultured on a single layer of collagen gel showed abnormal formation of stress fibers. These studies suggest that simple manipulations of the configuration of extracellular elements can dramatically alter the behavior of cultured hepatocytes.
Mathematical Model for the Effects of Epidermal Growth Factor Receptor Trafficking Dynamics on Fibroblast Proliferation Responses
Authors: Starbuck Cindy , Lauffenburger Douglas A. 
Published: March 2005

AbstractWe apply a mathematical model for receptor‐mediated cell uptake and processing of epidermal growth factor (EGF) to analyze and predict proliferation responses to fibroblastic cells transfected with various forms of the EGF receptor (EGFR) to EGF. The underlying conceptual hypothesis is that the mitogenic signal generated by EGF/EGFR binding on the cell surface, via stimulation of receptor tyrosine kinase activity, is attenuated when the receptors are downregulated and growth factor is depleted by endocytic internalization and subsequent intracellular degradation. Hence, the cell proliferation rate ought to depend on receptor/ligand binding and trafficking parameters as well as on intrinsic receptor signal transduction properties. The goal of our modeling efforts is to formulate this hypothesis in quantitative terms. The mathematical model consists of kinetic equations for binding, internalization, degradation, and recycling of EGF and EGFR, along with an expression relating DNA synthesis rate to EGF/EGFR complex levels. Parameter values have been previously determined from independent binding and trafficking kinetic experiments on B82 fibroblasts transfected with wild‐type and mutant EGFR. We show that this model can successfully interpret literature data for EGF‐dependent growth of NR6 fibroblasts transfected with wild‐type EGFR. Moreover, it successfully predicts the literature observation that NR6 cells transfected with a Δ973 truncation mutant EGFR, which is kinase‐active but internalization‐deficient, require an order of magnitude lower EGF concentration than cells with wild‐type EGFR for half‐maximal proliferation rate. This result demonstrates that it may be feasible to genetically engineer mammalian cell lines with reduced growth factor requirements by a rational, nonempirical approach. We explore by further model computations the possibility of exploiting other varieties of EGFR mutants to alter growth properties of fibroblastic cells, based on relationships between changes in the primary structure of the EGF receptor and the rates of specific receptor/ligand binding and trafficking processes. Our studies show that the ability to predict cell proliferation as a function of serum growth factors such as EGF could lead to the designed development of cells with optimized growth responses. This approach may also aid in elucidation of mechanisms underlying loss of normal cell proliferation control in malignant transformation, by demonstrating that receptor trafficking dynamics may in some cases play as important a role as intrinsic signal transduction in determining the overall resulting mitogenic response.
Immunoadsorption: Strategies for Antigen Elution and Production of Reusable Adsorbents
Authors: Yarmush Martin L. , Antonsen K. Pickard , Sundaram Srikanth , Yarmush David M. 
Published: March 2005

AbstractImmunoadsorption is a powerful and generalizable method for protein purification that exploits the fine specificity of antigen‐antibody interactions. In spite of its potential utility, the more widespread process scale use of immunoadsorption has been limited by the high cost of the antibody and the lack of gentle elution schemes that completely preserve the activity of both the immunoadsorbent and the eluted product. In this report, we review common chemical elution strategies such as pH, ionic strength, chaotropic salts, denaturants, and organic solvents as well as physical techniques such as pressure, electrokinetics, and temperature. In general, selection of elution strategies has largely been an empirical art, balancing stability of the immunoadsorbent and the eluted product and efficiency. The limitations of the available choices demonstrate that more attention must be placed on the antibody. Techniques which assist in the identification or creation of new antibodies with improved binding properties and resistance to degradation, e.g., screening and/or rational protein engineering, are also discussed.
Mixing of Highly Viscous Simulated Xanthan Fermentation Broths with the Lightnin A‐315 Impeller
Authors: Galindot Enrique , Nienow Alvin W. 
Published: March 2005

AbstractThe power characteristics of the Lightnin A‐315 impeller have been evaluated in solutions of Xanthan and Carbopol of similar rheological properties, the latter being transparent to allow flow visualization. With the impeller pumping downward (forward mode), at Re<20, Po α Re−1; for 20≤Re≤300, Po α Re−½; and at Re>600, Po was almost constant ≃1. In addition, for 20≤Re≤250, higher values of Po were found at equal Re, at higher levels of elasticity in the fluids. In the reverse mode, the same trend was found although Po was lower at the same Re. Upon aeration, no significant influence of the aeration rate (0.25−1.0vvm) upon the gassed power was observed. In the forward mode, a decrease in the Pog/Po ratio was observed, reaching levels of about 0.5–0.6 at the highest stirring speed (∼7 s−1, Re=200–800). During operation in the reverse mode, a minimum (or a plateau) Pog/Po value was observed and better gas dispersion was achieved. With the highest Xanthan concentration (35 kg m−3), high torque fluctuations were observed, though these were negligible in the inelastic Carbopol solutions of similar apparent viscosity. Video recordings made with transparent Carbopol solutions revealed very poor gas dispersion. Well‐defined “caverns” were also observed in the Carbopol solution. The reverse mode gave cavern volumes up to 60% larger than the forward mode, if the modes are compared at the same power drawn. The previously derived equations for cavern sizes which have been shown to predict well for a range of impellers were not found to be entirely satisfactory with this one in either pumping mode. Although the A‐315 impeller may not be a suitable impeller for mixing highly concentrated Xanthan broths because of the drastic power drop and large torque instabilities, the reverse mode is an interesting possibility for moderately concentrated Xanthan broths giving better gas dispersion, less torque fluctuations, lower power drop, and larger cavern volumes than the forward, downward pumping mode.
A Model for β‐Galactosidase Production with a Recombinant Yeast Saccharomyces cerevisiae in Fed‐Batch Culture
Authors: Hardjito Linawati , Greenfield Paul F. , Lee Peter L. 
Published: March 2005

AbstractAn unstructured model is developed to describe the growth and product formation behavior of a recombinant yeast Saccharomyces cerevisiae using β‐galactosidase as a model protein. The model shows good agreement with the experimental data over a range of conditions. It also accurately predicts the effect of growth rate on yield coefficient and gene expression. The simplicity and accuracy of the model make it suitable for designing and implementing control and optimization strategies for the production of recombinant proteins at large scale.
An Anionic Galactomannan Polysaccharide Gum from a Newly‐Isolated Lactose‐Utilizing Bacterium. I. Strain Description and Gum Characterization
Authors: Flatt James H. , Hardin Robert S. , Gonzalez Juan M. , Dogger Dina E. , Lightfoot Edwin N. , Cameron Douglas C. 
Published: March 2005

AbstractAs part of an effort to obtain microorganisms able to produce polysaccharide gums from whey and whey permeate, soil samples from farm fields regularly treated with whey were screened for bacteria able to produce gums from lactose. The most promising organism isolated (ATCC 55046) is a facultative anaerobe, tentatively identified as a new Erwinia species on the basis of biochemical and morphological tests. The organism produces a polysaccharide gum from lactose and other sugars (herein named lactan gum) composed of mannose, galactose, and galacturonic acid with an approximate molar ratio of 5:3:2 and containing no organic acid modifying groups. The weight average molecular weight of the gum is approximately 7 × 106. Aqueous solutions of lactan gum exhibit shear‐thinning and elastic flow behavior with an estimated power law model flow index of 0.26 at 1 % (w/w) gum. The viscosity of aqueous 1 % (w/w) lactan gum solutions is stable over a pH range of 2–11, being particularly stable in alkaline environments. Aqueous 1% (w/w) gum solutions at pH 5–11 show excellent thermostability, retaining at least 80% of the original viscosity after being heated to 121 °C for 15 min. These flow properties indicate potential industrial applications in food and nonfood products requiring a moderate degree of thickening, wet‐end additives and coating agents for paper products, ceramics, detergents, and binders for building materials.
Monitoring Intracellular Protein Profiles with Two‐Dimensional Gel Electrophoresis
Authors: Dykstra Kevin H. , Wang Henry Y. 
Published: March 2005

AbstractTwo‐dimensional polyacrylamide gel electrophoresis (2D PAGE) is a method of separating complex protein mixtures, such as whole cell extracts, on the basis of protein isoelectric point and molecular weight. In bioprocess engineering, conventional 2D PAGE has tremendous potential to yield detailed information on the intracellular effect of various process conditions. It has been used in our work to examine global intracellular changes occurring in a typical cycloheximide fermentation and to look at the feedback regulatory behavior of cycloheximide biosynthesis. Application of the technique for bioprocess monitoring will require that the time necessary for preparation of a 2D electropherogram be substantially shortened. This may be accomplished by performing the separation on a miniature scale or eventually by use of capillary electrophoresis for one or more of the separations. Advantages and disadvantages of these two approaches are discussed.
Affinity Precipitation of Proteins by Surfactant‐Solubilized, Ligand‐Modified Phospholipids
Authors: Powers Daniel D. , Willard Betsy L. , Carbonell Ruben G. , Kilpatrick Peter K. 
Published: March 2005

AbstractThe use of ligand‐modified phospholipids solubilized in aqueous solution by nonionic surfactant for affinity precipitation of proteins is described. Avidin was precipitated by contact with solutions in which dimyristoylphosphatidylethanolamine (DMPE) functionalized with biotin (DMPE‐B) was solubilized in octaethylene glycol mono‐n‐dodecyl ether (C12E8) solutions. The nonionic surfactant solubilizes the phospholipid in micelles above its critical micelle concentration (CMC) and in small submicellar aggregates below this concentration. At C12E8 concentrations significantly exceeding its CMC, determined to be about 100 μM, precipitation of avidin by solubilized DMPE‐B is not observed. In this regime, binding of protein by DMPE‐B was monitored by a hyperchroic shift in the protein's UV–visible spectrum at 231.5 nm. The data were analyzed using a model that considers the four binding sites on the protein to be independent and identical in binding strength for DMPE‐B. Below the CMC of C12E8, precipitation is observed and is monitored by increasing turbidity of the solution. The kinetics of precipitation and the aggregate size measured by quasielastic light scattering were analyzed using Smoluchowski kinetics and the Mie scattering theory. These results help establish more completely the factors that influence the precipitation of proteins by ligand‐modified phospholipids, and they are helpful in specifying conditions for the precipitation of other proteins.
Effect of Equilibrium Relative Humidity on the Mechanical Signatures of Brittle Food Materials
Authors: Rohde Florian , Normand Mark D. , Peleg Micha 
Published: March 2005

AbstractThree brittle commercial bakery products (bread sticks, pretzels, and zwiebacks) were compressed after equilibration at five relative humidity levels with a computer‐interfaced Universal Testing Machine. Their mechanical signatures are presented in the form of conventional force—time relationships, power spectra calculated by the fast Fourier transform, Richardson plots from which the apparent fractal dimension was calculated, and displays of the symmetrized‐dot pattern (SDP) produced from the original force—time relationships. It is demonstrated that, although the original force—time relationships were irregular and irreproducible, consistent patterns and values did emerge in the transformed data. Plasticization, as a result of moisture sorption, is clearly expressed in the disappearance of the high‐frequency region of the power spectrum and a drastic decrease in the magnitude of the apparent fractal dimension. The differences among the shapes of the original force—deformation curves before and after moisture sorption are also clearly evident from the SDP displays, but the sensitivity of the method needs to be established with a larger experimental data base.