bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal loss in mice exposed to magnetic fields during early pregnancy
Authors: Svedenstål Britt‐Marie , Johanson Karl‐Johan 
Published: February 2006

AbstractThe effects of low‐frequency magnetic fields (MFs) on early pregnancy were studied in CBA/S mice. The magnetic field was a 20 kHz, 15 μT sawtooth. Pregnant females were divided into four groups, two control groups and two exposed groups. One group was exposed to MFs continuously from day 1 postconception (pc) until day 5.5 pc, and the other group was exposed continuously until day 7 pc. All animals were sacrificed on day 19 pc, the day before partus, and their uterine contents were analyzed. No significant increase in the resorption (early fetal death) rate was found in the exposed animals compared to the sham controls. In the group exposed during days 1.0–5.5 pc, the body weight and length of the living fetuses were significantly decreased. Except on day 3 pc (progesterone) and day 13 pc (calcium) in the treated groups, there were no significant differences in progesterone and calcium levels in peripheral blood. Implantation occurred on the same day in MF‐treated and control animals. © 1995 Wiley‐Liss, Inc.
Absence of radiofrequency heating from auditory implants during magnetic resonance imaging
Authors: Chou C. K. , McDougall J. A. , Chan K. W. 
Published: February 2006

AbstractThe possibility of tissue heating due to an auditory brainstem implant (ABI) or a modified cochlear implant (CI) during magnetic resonance imaging (MRI) of the head was tested on a full‐sized human phantom using a realistic phantom head consisting of simulated skull, brain, and muscle. Dielectric properties of the brain, muscle, and bone materials were similar to those of human tissues at 64 MHz. The body consisted of homogeneous phantom muscle enclosed in a human‐shaped fiberglass shell. Thermographic and fiber‐optic temperature measurements were conducted to reveal any heating. Thermograms of sagittal, frontal, and horizontal planes of the head with the ABI and CI electrodes were taken immediately before and after a 26 min MRI scan. The MRI sequence was set at 94 excitations and 25 ms echo time to induce maximum radiofrequency heating, as suggested by the General Electric Company. The difference of these two thermograms gives the heating results. In two uncut phantom heads, Teflon tubes were placed along the implanted ABI and CI, and temperature data were recorded via fiber‐optic probes before, during, and after the MRI. Results showed no observable heating associated with the ABI and the modified CI during worst‐case MRI of the head. © 1995 Wiley‐Liss, Inc.
Zur Dauerhaftigkeit externer Spannglieder bei wechselnden Beanspruchungen
Authors: Hegger Josef , Neuser Jens U. , Peters Sonja , Schmitz Martin 
Published: February 2006

AbstractExterne Spannglieder sind an Umlenkstellen wechselnden Beanspruchungen aus Temperatur und geringen Relativverschiebungen ausgesetzt. In einem vom Deutschen Institut für Bautechnik (DIBt) geförderten Forschungsvorhaben wurden die Auswirkungen dieser wechselnden Beanspruchungen untersucht, um den Korrosionsschutz von im Bauwerk eingesetzten externen Spanngliedern besser beurteilen zu können.
Zur Querkraftbemessung bei Kreisquerschnitten. Teil 1: Bauteile ohne Querkraftbewehrung
Authors: Bender Michél , Mark Peter 
Published: February 2006

AbstractDie Querkraftwiderstände nach DIN 1045‐1 schließen Träger mit Kreisquerschnitt zunächst nicht ein. Nach Auslegung des Normenausschusses Bauwesen (NABau) kann ein rechteckiger Ersatzquerschnitt angenommen werden. Dies erweist sich für Träger aus Normalbeton ohne Bügelbewehrung im Vergleich zu experimentellen Daten als konservativ, ist allerdings mit erheblichen Streuungen verbunden. Basierend auf dem Konzept der DIN 1045‐1 wird ein praxisorientierter Ansatz für den Widerstand VRd,ctfür nicht bügelbewehrte Träger mit Kreisquerschnitt vorgestellt, welcher die bekannten Einflußgrößen von Geometrie, Längsbewehrungsgrad und Betonfestigkeit – speziell auf die Verhältnisse bei Kreisquerschnitten zugeschärft – einschließt. Die positiven Wirkungen drückender Normalkräfte sind darin über einen additiven Sprengwerkansatz einbezogen. Der Ansatz wird statistisch beurteilt und an Experimenten verifiziert.
Verbundstützen der Bügelbauten über dem Berliner Hauptbahnhof
Authors: Petersen Lasse , Naujoks Bernd 
Published: February 2006

AbstractMit den heute zur Verfügung stehenden Betonzusatzmitteln können Betonrezepturen entwickelt werden, die ein sehr effizientes Vorgehen beim Verfüllen von Verbundstützen ermöglichen. Dabei werden Stahlprofile über tiefliegende Einfüllstutzen mit Beton zuverlässig und entmischungsfrei auch über große Höhen ohne zusätzliche Verdichtungsenergie vollständig verfüllt. Der vorliegende Beitrag berichtet über die Errichtung der tragenden Verbundkonstruktion der Bügelbauten des Berliner Hauptbahnhofs, bei der diverse Stahlhohlprofile zu Verbundstützen ausbetoniert wurden. Die Stahlprofile, in denen teilweise sehr hohe Bewehrungsgehalte und aufwendige Einbauteile vorhanden waren, wurden bis zu Höhen von ca. 25 m in einem Arbeitsgang mit einem speziell dafür entwickelten Beton der Festigkeitsklasse C45/55 verfüllt.
Phosphorylated and nonphosphorylated epitopes of the La/SSB autoantigen: Comparison of their antigenic and conformational characteristics
Authors: Coudevylle Nicolas , Rokas Dimitrios , Sakarellos‐Daitsiotis Maria , Krikorian Dimitrios , Panou‐Pomonis Eugenia , Sakarellos Constantinos , Boussard Guy , Cung Manh Thong 
Published: February 2006

AbstractLa/SSB phosphoprotein is the target antigen of autoantibodies in sera of patients with Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE). Among other structural and function motifs, four phosphorylation sites are encompassed in the primary sequence of La/SSB. Two of them (Thr‐362 and Ser‐366) are located within GSGKGKVQFQGKKTKFASDD (346–368) and one (Thr‐302) within VTWEVLEGEVEKEALKKI (301–318), which are main B‐cell epitopes of La/SSB. With the aim to investigate how phosphorylation, one of the most common posttranslational protein modifications, affects the antigenic and conformational characteristics of the La/SSB epitopes, we synthesized and studied the phosphorylated epitopes La/SSB(346–368)‐P, La/SSB(359–368)‐P, and La/SSB(301–318)‐P with respect to their nonphosphorylated counterparts. Anti‐La/SSB positive sera from SS and SLE patients are better recognized by the phosphorylated epitopes compared to their nonphosphorylated counterparts. Conformational analysis by1H nuclear magnetic resonance spectroscopy and molecular dynamics showed that the phosphorylated epitopes adopt different structural characteristics from those of the corresponding nonphosphorylated epitopes. It is concluded that phosphorylation can create neoepitopes with altered functions, compared to the nonphosphorylated epitopes, which might be seen from the immune system as “foreign.” © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 368–382, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Plate height determination for gradient elution chromatography of proteins
Authors: Yamamoto Shuichi 
Published: February 2006

AbstractA method for determining the plate height HETP from the elution curve obtained by the linear gradient elution (LGE) ion‐exchange chromatography (IEC) of proteins is presented. The method was developed on the basis of the numerical solutions of a chromatography model which considers the zone sharpening and the distribution coefficient as a function of the salt concentration. The plate height HETP is determined from the peak width and the salt concentration at which the peak is eluted in LGE. The method was applied to the experimental results with various ion‐exchange chromatography media. A calculation example based onthe present method is presented to show how the chromatographic and operating parameters should be tuned to obtain a desired resolution. A simplified calculation procedure for the peak profile is also described. © 1995 John Wiley & Sons, Inc.
Countercurrent gradient chromatography: A continuous focusing technique
Authors: Evans Lisa L. , Burns Mark A. 
Published: February 2006

AbstractThe continuous separation of proteins was performed in a countercurrent gradient chromatography (CGC) system. A magnetically stabilized fluidized bed (MSFB) was used to establish true countercurrent contact of a solid resin with a liquid buffer. STable pH gradients were formed in the system in less than 10 min and remained stable throughout the course of the separation experiment (>2 h). The shape of the pH gradient, which ultimately controls the resolution and purity of the separation, can be controlled by making simple adjustments in the interstitial velocities of the liquid and solid phases. We have performed the separation of myoglobin and human serum albumin (HSA) using this device and achieved concentration factors of 1.75 for myoglobin and 1.2 for HSA. A mathematical model that has no adjustable parameters has been developed that predicts the focusing behaviour and capabilities of the CGC system. Using the model, we have estimated the optimum phase velocities, particle diameters, and equilibrium parameters necessary for achieving high purity and high concentrations. © 1995 John Wiley & Sons, Inc.
Review: Protein refolding and inactivation during bioseparation: Bioprocessing implications
Authors: Sadana Ajit 
Published: February 2006

AbstractThe recombinant production of proteins leads to inclusion bodies which contain aggregated proteins in active, partially active, and inactive conformational states. These aggregated proteins must be extracted from the inclusion bodies, unfolded, and carefully refolded to the active and the stable conformational state. Mechanistic models for protein refolding are briefly presented. Different strategies and protocols are presented that lead to the active and stable protein conformational state. The techniques presented include chaperonin‐assisted refolding, amino acid substitution, polyethylene glycolassisted refolding, protein refolding in reverse micelles, and antibody‐assisted refolding of proteins. The techniques presented together provide a reasonable framework of the state‐of‐the‐art and may be carefully applied to the bioseparation of other proteins and biological macromolecules of interest. © 1995 John Wiley & Sons, Inc.
Chemical instability of protein pharmaceuticals: Mechanisms of oxidation and strategies for stabilization
Authors: Li Shihong , Schöneich Christian , Borchardt Ronald T. 
Published: February 2006

AbstractOxidation is one of the major chemical degradation pathways for protein pharmaceuticals. Methionine, cysteine, histidine, tryptophan, and tyrosine are the amino acid residues most susceptible to oxidation due to their high reactivity with various reactive oxygen species. Oxidation during protein processing and storage can be induced by contaminating oxidants, catalyzed by the presence of transition metal ions and induced by light. Oxidative modification depends on the structural features of the proteins as well as the particular oxidation mechanisms inherent in various oxidative species, and may also be influenced by pH, temperature, and buffer composition. Protein oxidation may result in loss of biological activity and other undesirable pharmaceutical consequences. Strategies to stabilize proteins against oxidation can be classified into intrinsic methods (site‐directed mutagenesis and chemical modification), physical methods (solid vs. liquid formulations) and use of chemical additives. The optimum choice of chemical additives needs to be evaluated on the basis of the specific oxidation mechanism. Oxidation induced by the presence of oxidants in the system is referred to as a non‐site‐specific mechanism. Under such conditions, oxidation can be effectively inhibited by the appropriate addition of antioxidants or free radical scavengers. metal‐catalyzed oxidation is a site‐specific process, in which the addition of antioxidants may accelerate the oxidation reaction. Careful screening of chelating agents has been shown to be an alternative method for preventing metal‐catalyzed oxidation. © 1995 John Wiley & Sons, Inc.
The Use of RP‐HPLC for measuring activation and cleavage of rFVIIa during purification
Authors: Mollerup Inger , Bayne Stephen , Halkjaer Erik , Jørgensen Tony , Mandrup Gitte , Nicolaisen Else Marie , Thim Lars 
Published: February 2006

AbstractA reverse phase HPLC (RP‐HPLC) method for analysis of recombinant factor VIIa (rFVIIa) has been developed. The method discriminates between different forms of recombinant FVII (rFVII). To obtain separation of these closely related molecules the method has been optimized with respect to gradient profile and temperature. The method has been used for optimization of purification processes and for kinetic studies. EVidence for autolytic cleavage was obtained. © 1995 John Wiley & Sons, Inc.
Development of surface swabbing procedures for a cleaning validation program in a biopharmaceutical manufacturing facility
Authors: Lombardo Silvia , Inampudi Prasad , Scotton Anthony , Ruezinsky Gary , Rupp Randall , Nigam Somesh 
Published: February 2006

AbstractValidation of direct surface swabbing procedure in conjuction with total organic carbon (TOC) analysis is described for a biopharmaceutical product manufacturing operation. The swabbing technique was found to be very effective in reliably detecting very low levels of residuals for diverse process streams (limit of detection of approximately 0.5µg/cm2). However, contaminant recovery was significantly dependent on both the type of contaminant and the processing surface. This study serves as a guide for designing effective cleaning validation protocols based on direct surface swabbing techniques. © 1995 John Wiley & Sons, Inc.
Purification of a pyrogen‐free human growth hormone antagonist
Authors: Gu Tingyue , Zheng Yizhou , Gu Yesong , Haldankar Raj , Bhalerao Nihar , Ridgway Darin , Wiehl Paul E. , Chen Wen Y. , Kopchick John J. 
Published: February 2006

AbstractHuman growth hormone (hGH) is a polypeptide with 191 amino acids and a molecular mass of 22 kilodaltons. With the aid of computer molecular simulation, an hGH analog was created by altering an hGH gene to reflect the change of one amino acid (glycine [G] 120 to arginine [R]) within the third α‐helix of the hGH molecule. This hGH analog, named hGHG120R, was found to be an hGH antagonist. It may have important implications in treating human conditions in which hGH levels are abnormally high, as found in type I diabetics. Several hundred milligrams of purified hGHG120R were needed to determine the biological activity of the antagonist in animal models. A multistep downstream process was developed to purify hGHG120R from cultured mouse L cells transfected with the hGHG120R gene. The process consisted of cell clarification, salt precipitation, membrane ultrafiltration, reversed phase high performance liquid chromatography, phase separation, and lyophiliation. This work discusses the rationale for the design of the process and experimental results on the purification of hGHG120R using the process. © 1995 John Wiley & Sons, Inc.
Large scale purification of myo‐inositol monophosphate phosphatase from porcine brains
Authors: Kwok Francis , Wang Xing Hua , Cheng Christopher H. K. , Lo Samuel C. L. 
Published: February 2006

Abstractmyo‐Inositol monophosphate phosphatase (IMPase) has been purified 888‐fold to apparent homogeneity from procine brains. The purification procedure involves: homogenization, ammonium sulfate fractionation, and a number of ion‐exchange and gel‐filtration chromatography steps. The purified enzyme exhibited a final specific activity of 932 nmol · min−1 · mg−1. The molecular mass of the enzyme was estimated to be 29kDa by SDS poly‐acrylamide gel electrophoresis and 58 ± 5 kDa by HPLC gel filtration in 10mM Tris‐HCI, pH 7.4. Kinetic measurements have shown that the apparent Km value of the phosphatase for the utilization of inositol‐1‐phosphate and β‐glycerol phosphate are 3.20 × 10−4 and 8 × 10−3 M, respectively. Similar to the same enzyme isolated from bovine brains, the porcine brain enzyme has been shown to be inhibited by lithium. The K1 was determined to be 6.38 × 10−4 M and the inhibition is uncompetitive. © 1995 John Wiley & Sons, Inc.
Fermentation and isolation of C10‐deacetylase for the production of 10‐deacetylbaccatin III from baccatin III
Authors: Nanduri Venkata B. , Hanson Ronald L. , LaPorte Thomas L. , Ko Raphael Y. , Patel Ramesh N. , Szarka Laszlo J. 
Published: February 2006

Abstract10‐Deacetylabaccatin III (10 DAB), an important precursor for paclitaxel semisynthesis, is enhanced in yew extracts using C10‐deacetylase and C13‐deacylase enzymes.4 C10‐deacetylase is an intracellular enzyme produced by the fermentation of a soil microorganism, Nocardioides luteus (SC 13912). During the fermentation of Nocardioides luteus, the growth of cells reaches a maximum growth at 28 h. C10‐deacetylase enzyme activity starts at 26 h and peaks at 38 h of the fermentation. The cells are recovered by centrifugation. The C10‐deacetylase enzyme was purified from the Nocardioides luteus cells. The enzyme was purified 190‐fold to near homogeneity. The purified enzyme appeared as a single band on 12.5% SDS‐PAGE analysis with a molecular weight of 40,000 daltons. © 1995 John Wiley & Sons, Inc.
Fermentation and recovery of glutamic acid from palm waste hydrolysate by Ion‐exchange resin column
Authors: Das K. , Anis M. , Azemi B. M. N. Mohd. , Ismail N. 
Published: February 2006

AbstractGlutamic acid produced from palm waste hydrolysate by fermentation with Brevibacterium lactofermentum ATCC 13869 is produced with a remarkably high yield compared with that produced from pure glucose as a carbon source. The produce yield is 70 g/L with glucose, wherease, when palm waste hydrolysate is the fermentation medium in the same bioreactor under same conditions, it is 88 g/L. The higher yield may be attributed to the fact that this organism has the ability to convert sugars other than only glucose present in the hydrolysate. Bioreactor conditions most conducive for maximum production are pH 7.5, temperature of 30°rmentation period of 48 h, inoculum size 6%, substrate concentration of 10 g per 100 mL, yeast extract 0.5 g per 100 mL as a suitable N source, and biotin at a concentration of 10 pg/L. Palm waste hydrolysate used in this study was prepared by enzymic saccharification of treated palm press fiber under conditions that yielded a maximum of 30 g/L total reducing sugars. Glutamic acid from fermentation broth was recovered by using a chromatographic column (5cm × 60 cm) packed with a strong ion‐exchange resin. The filtered broth containing glutamic acid and other inorganic ions was fed to the fully charged column. The broth was continuously recycled at a flow rate of 50 mL/min (retention time of 55 min) until glutamic acid was fully adsorbed on the column leaving other ions in the effluent. Recovery was done by eluting with urea and sodium hydroxide for total displacement of glutamic acid from the resin. The eluent containing 88 g/L of glutamic acid was concentrated by evaporation to obtain solid crystals of the product. © 1995 John Wiley & Sons, Inc.
Preparation of a Nanowire‐Structured Polyaniline Composite and Gas Sensitivity Studies
Authors: Ma Xingfa , Li Guang , Wang Mang , Cheng Yunan , Bai Ru , Chen Hongzheng 
Published: February 2006

AbstractTo obtain organic nanowire sensors with high sensitivity and rapid response times, based on the inducement effect of surfactants during in situ polymerization, nanostructured polyaniline composites are obtained by using a chemical oxidation method by adding a small amount of surfactant. A casting method is employed on interdigitated carbon electrodes. The gas sensitivity to a series of chemical vapors is examined at room temperature. The results indicate that polyaniline with regular nanowire structure is obtained when succinic acid is added. The gas sensitivity and response rates of a film with nanowire structure are much better than those of conventional polyaniline films produced by means of organic solution spin coating methods. The film described in this work shows good selectivity to trimethylamine and other related gases and, the reaction being reversible with the ues of high‐purity nitrogen.
Polyelectrolyte Templated Polymerization in Langmuir Films: Nanoscopic Control of Polymer Chain Organization
Authors: Chandra M. Sharath , Radhakrishnan T. P. 
Published: February 2006

AbstractPolyelectrolytes introduced in the aqueous subphase are shown to have a profound impact on the kinetics of polymerization of N‐octadecylaniline at the air/water interface. This can be attributed to changes effected in molecular organization and reorientation behavior in the Langmuir film. The polyelectrolyte templates lead to considerable modification of the morphology of the monomer and polymer Langmuir films. Polyelectrolyte complexation is found to be an elegant and efficient methodology to achieve enhanced alignment of the polyaniline chains in the transferred Langmuir–Blodgett (Langmuir–Schafer) film.
Selective Oxidation of Alkanes with Molecular Oxygen and Acetaldehyde in Compressed (Supercritical) Carbon Dioxide as Reaction Medium
Authors: Theyssen Nils , Hou Zhenshan , Leitner Walter 
Published: February 2006

AbstractThe oxidation of cycloalkanes or alkylarenes with molecular oxygen and acetaldehyde as sacrificial co‐reductant occurs efficiently in compressed (supercritical) carbon dioxide (scCO2) under mild multiphase conditions. No catalyst is required and high‐pressure ATR‐FTIR online measurements show that a radical reaction pathway is heterogeneously initiated by the stainless steel of the reactor walls. For secondary carbon atoms, high ketone to alcohol ratios are observed (3.5–7.9), most probably due to fast consecutive oxidation of alcoholic intermediates. Since CC scission reactions are detected only to a very small extent, tertiary carbon atoms are transformed into the corresponding alcohols with high selectivity. Detailed analysis of the product distributions and other mechanistic evidence suggest that acetaldehyde acts not only as the sacrificial oxygen acceptor, but also as an efficient H‐atom donor for peroxo and oxo radicals and as a crucial reductant for hydroperoxo intermediates. In comparison to other inert gases such as compressed N2 or Ar, the use of carbon dioxide was shown to increase the yields of alkane oxygenates under identical reaction conditions.