bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peptide capillary zone electrophoresis mass spectrometry of recombinant human erythropoietin: An evaluation of the analytical method
Authors: Boss Hollis J. , Watson Daniel B. , Rush Robert S. 
Published: May 2005

AbstractAn evaluation of capillary zone electrophoresis‐mass spectrometry (CZE‐MS) as an analytical methodology for the separation and characterization of complex glycopeptides and nonglycopeptide structures has been performed. The evaluation employed endoproteinase V8 digested recombinant human erythropoietin (rHuEPO) that was further fractionated by reverse phase chromatography. The peptides were subjected to sequence analysis and evaluated by capillary electrophoresis, with or without mass detection, for peptide purity. The peptide mass determined from the sequence was then compared to the mass obtained from CZE‐MS. Glycosylation sites and carbohydrate branch patterns were easily determined, site specific microheterogeneity (either O‐acetylation of N‐acetylneur‐aminic acids or lactosamine extensions of the carbohydrate chain length) was assessed directly, glycosylation site occupancy was evaluated qualitatively, and nonglycopeptides were resolved and analyzed on‐line with ease. Incomplete peptide digestion products were detected and identified by CZE‐MS. Protein sequence coverage by CZE‐MS was 98.2 percent complete from a single map. Offline evaluation of peptide purity by CZE greatly aided the interpretation of multiple sequence analysis and, in validating that, the CZE‐MS was detecting all peptides present. All off‐line CZE and on‐line CZE‐MS experiments employed a capillary that was dynamically coated with Polybrene in the presence of polyethylene glycol; separations were conducted in 0.67 M formic acid.
Characteristics of selective polymerase chain reaction (PCR) using two‐base anchored primers and improvement of its specificity
Authors: Okano Kazunori , Uematsu Chihiro , Matsunaga Hiroko , Kambara Hideki 
Published: May 2005

AbstractWe have developed a reliable method for eliminating base‐mispair amplification in selective polymerase chain reaction (PCR), which is utilized for amplifying unknown sequence fragments produced by restriction enzyme reaction. The proposed procedure applies amplified fragment length polymorphism (AFLP) with high fidelity. Selective PCR utilizes the known polymerase reaction characteristic that the complementary strand extension is strongly affected by matching a template with the 3′‐terminus of the primers. However, false positive amplification is frequently observed because the specificity of terminal bases for discrimination of fragments (usually, 1–3 anchor sequences) is not enough to separate each fragment. A protocol for the selective PCR separation of every fragment was therefore investigated. A single‐base mismatch was artificially introduced on the 4th base position from the 3′ end of the primers to improve the hybridization specificity of anchored 2‐bases at the 3′ termini of primers. PCR reaction was carried out at 66°C to prevent false positive amplification. The concentration of the primers having anchored‐base sequences of AA, AT, TA, and TT must be three times larger than that of other primers because the Tm values for these sequences are lower than the others. As all the fragments can be separated into groups with high fidelity, the improved selective PCR will be applied to gene finding and analyzing differences on genome sequences based on AFLP.
Minisatellite variant repeat (MVR) analysis of the HRAS1 minisatellite locus
Authors: Vega Ana , Barros Francisco , Bellas Susana , Carracedo Angel 
Published: May 2005

AbstractTwo alternative electrophoretic strategies were used to study the internal variation of the HRAS1 minisatellite after minisatellite variant repeat mapping (MVR‐PCR) was carried out. While the use of automated sequencers with fluorescent based technology is ideal for analyzing fragment size, and therefore, for analyzing the repeat number, the use of polyacrylamide gels and silver staining is more appropriate for the analysis of internal variation. Thirteen different fragments ranging from 27 to 80 repeats were found in a sample from 80 healthy Caucasian individuals. By using MVR mapping we were able to detect heterozygotes which appear as homozygotes when fragment length analysis was used. As a result of this, the 13 alleles, which we had detected, increased to 16 alleles when MVR sequences were analyzed. The extremely conservative arrays of repeats allow us to infer the theoretical origin of rare alleles from a major group of specific alleles. The HRAS1 minisatellite has been extensively studied due to its association with cancer. However, the methodology used up to now has limited the scope of previous research. Our approach permits the identification of alleles in a fast and reliable way using their MVR codes, thus allowing association studies with cancer.
Stability of continuous flow electrophoresis
Authors: Weber Gerhard , Boček Petr 
Published: May 2005

AbstractThe stability of continuous flow electrophoresis (CFE) was tested by performing uninterrupted continuous flow cationic isotachophoresis for 15 h, using a mixture of two synthetic isoelectric point (pI) markers as the model sample. This sample as well as the other operational electrolytes were continuously pumped into the CFE separation chamber via 10 individual inlets. The operational electrolyte system and the arrangement of the electrolyte streams were selected in accord with previously published results, providing a stable electrophoretic regime. The chamber had 96 individual outlets and here 96 individual fractions were collected in microwell plates in regular time intervals and scanned photometrically. The scanned photometric patterns proved that CFE is sufficiently stable for an overnight operation.
Finding a universal low viscosity polymer for DNA separation (II)
Authors: Heller Christoph 
Published: May 2005

AbstractWhen investigating the use of different polymers for capillary electrophoresis we found that poly‐N,N‐dimethylacrylamide (pDMA) has a very low viscosity compared to other polymers of comparable molecular mass and resolving power. This makes it a potentially useful matrix for DNA separation in multi‐capillary electrophoresis, where short cycle times or low pressure for matrix replacement are preferred. We have characterized this matrix by systematic studies on concentration, chain length and field strength dependence. It is shown that pDMA performs well for the separation of oligonucleotides and double‐stranded DNA fragments. Together with the application of DNA sequencing, pDMA is a universal polymer for the separation of biological macromolecules.
A theory for the electrophoretic separation of DNA in polymer solutions
Authors: Sunada Wade M. , Blanch Harvey W. 
Published: May 2005

AbstractWe present a mathematical model of DNA capillary electrophoresis in polymer solutions based on nonentangling collisions between DNA and polymer molecules. Using videomicroscopy images of DNA migrating through polymer solutions, we propose a modified transient entanglement coupling mechanism for DNA separations that includes nonentangling DNA/polymer collisions. We show that a mathematical model based on individual nonentangling DNA/polymer collisions is able to predict the mobilities of DNA in solutions of low molecular mass polymer. We compare the model predictions to mobility data for separations of DNA in a range of concentrations for solutions of both hydroxypropylcellulose (Mw 100 000) and hydroxyethylcellulose (Mw 139 000). The model relies on one fitted parameter, the time constant for the interaction between the DNA and polymer molecules, which is based on the physical properties of DNA and polymers.
High‐frequency alternating‐crossed‐field gel electrophoresis with neutral or slightly charged interpenetrating networks to improve DNA separation
Authors: Boyd Brooks M. , Prausnitz John M. , Blanch Harvey W. 
Published: May 2005

AbstractToward improving DNA separations, this work reports the effects of high‐frequency square‐wave AC fields superimposed perpendicular to the direct current (DC) separation field on DNA migration in both polyacrylamide‐based interpenetrating networks (IPNs) and in agarose networks. Compared to standard polyacrylamide gels, IPNs allow the separation of larger DNA (9000 bp vs. 5000 bp at 5 V/cm). In novel polyacrylamide‐based IPNs, an alternating current (AC) field of 5 Hz increased the maximum DNA size separable. This effect was extended to larger DNA sizes with increasing electric‐field strength up to and apparently beyond the power supply‐limited maximum electric‐field strength of 48 V/cm. The orthogonal AC field also increased mobility. These two results combine to yield a reduction in separation time of up to a factor of 20 in novel polyacrylamide‐based IPNs. When negatively charged acrylic‐acid groups were incorporated into the IPNs, the use of the AC field changed the DNA‐network interaction, which altered the size dependence of DNA mobility. In agarose gels, an AC field of 50 Hz increased the size range separable; however, there was no increase in DNA mobility. There was no change in size dependence of mobility in an AC field when the number of charged groups in the agarose network was increased. Based on results in the literature, possible mechanisms were examined for the effects of the AC field on DNA separation.
Two‐dimensional electrophoretic analysis of membranous protein from human thyroid tissues and cancer cell lines
Authors: Lin Jen‐Der , Chan Err‐Cheng , Weng Hsiao‐Fen , Sheu Cherng‐An 
Published: May 2005

AbstractThyroid neoplasm is the most commonly encountered neoplastic disorder in endocrine clinics. Thyroid scan, ultrasonography, and fine needle aspiration cytology (FNAC) are used as diagnostic tools to differentiate a malignant nodule from a benign lesion. There are certain limitations and pitfalls in FNAC, especially in the diagnosing of follicular tumors. The lack of characteristic findings or a specific tumor marker are the most common problems in the preoperative diagnosis of thyroid follicular carcinoma. Although serum thyroglobulin level has been used as a tumor marker for post‐operative, well‐differentiated thyroid cancer, the assay cannot be used for preoperative diagnosis of thyroid carcinoma. In this study, various thyroid tissues and cancer cell lines including CGTH W‐1, CGTH W‐3, RO 82 W‐1, SW 579 cell lines were used for the investigation of tumor markers. Specific spots were identified in the area near the 60 kDa molecular mass protein and isoelectric point (pI) 5.9 of the CGTH W‐1 cell line. These spots could not be found in the papillary or anaplastic thyroid cancer cell lines. Another spot with a molecular weight of about 9.8 kDa with a low pI of 4.8 was present in the CGTH W‐1 and RO 82 W‐1 cell lines. This spot appeared to be a tumor marker of follicular cancer cells. This spot could not be found in the papillary and anaplastic cancer cell lines and other benign thyroid tissues. Specific proteins that were identified in this study may be useful as tumor markers for follicular thyroid carcinoma.
Studies of the smoke emission from burning poly‐(vinylchloride) plasticized with diisooctylphthalate
Authors: Delfosse L. , Špilda I. , Pavlik J. 
Published: May 2005

AbstractSmoke evolved from burning poly‐(vinychloride) plasticized with diisooctylphthalate has been studied using a light absorption method. It has been shown that the quantity of smoke produced depends upon the oxygen concentration of the oxidizing gas as well as on the concentration of diisooctylphthalate present in the polymer. The results of this work have been analysed using an empirical equation proposed by the authors, which correlates the maximum smoke density (σmax) with oxygen concentration. This equation may be written

where No2 is the molar concentration of oxygen in the oxidizing gas, and LOI refers to the limiting or critical concentration of oxygen at which at the polymer will just burn, as defined by the ASTM test 2863. The effect of various additives, particularly organic iodine compounds, as smoke suppressants has also been investigated.
Moving wire technique studies of ablation, ignition and extinction of polymer flames
Authors: Fristrom R. M. , Grunfelder C. 
Published: May 2005

AbstractA new experimental method for studying the ablation, ignition and extinction of polymers exposed to flames and other ignition sources is presented. The technique is called the ‘Moving Wire Technique’. The polymer sample is carried on a wire support which is moved uniformity through the ignition source which is a flame in the example given. In the laboratory coordinate system, points along the path of the wire correspond to increasing residence time. The polymer combustion thus becomes a steady‐state phenomena which can be studied at leisure with the improvements in precision associated with long time steady‐state measurements. In addition to steady‐state combustion, ignition and extinction transitions are observed whose onsets are sharp and can be accurately characterized in this system. In a favorable case, a reproducibility of a few parts per thousand is attained in determining critical ignition exposure times and extinction velocities. Results from initial studies of commercial Teflon® and poly‐(vinylchloride) are presented. Measurements include critical ignition times and extinction velocities a function of free oxygen concentration. For poly‐(vinylchloride), measurements are given of gas phase composition, mass loss of the polymer, and surface temperature of the polymer as a function of exposure time. A discussion is given of the relation of the results to other experiments and potential uses of the technique.
A comparison of flashover times in small‐scale fires using test data
Authors: Bullen M. L. 
Published: May 2005

AbstractReaction to fire standard tests on materials used as linings are not sufficient in themselves to predict the behaviour of growing fires. However, flashover times with cellulosic linings have been correlated qualitatively with the British test, but generally there is wide divergence in the test results from different countries. This report paper discusses some aspects of this problem.
Sensory irritation evoked by the thermal decomposition products of plasticized poly(vinyl chloride)
Authors: Barrow Craig S. , Alari Yves , Stock Maryanne F. 
Published: May 2005

AbstractA decrease in respiratory rate in mice during exposure to irritating airborne chemicals has been utilized as a response parameter to characterize the degree of upper respiratory tract irritation (sensory irritation) to the thermal decomposition products of plasticized poly(vinyl chloride). The plasticized poly(vinyl chloride) was placed in a low mass vertical furnace and thermally decomposed in an air atmosphere at a programmed heating rate of 20°C min−1. The thermogravimetric study of the plasticized poly(vinyl chloride) demonstrated that two distinct weight loss fractions occurred during the decomposition process. Groups of four male swiss‐webster mice were exposed to the thermal decomposition products of the first weight loss fraction in the range 0.03–0.77 mg l−1 and to the second weight loss fraction in the range 0.03–0.38 mg l−1. Dose‐response curves were plotted by utilizing the maximum percent decrease in respiratory rate during each exposure as the response parameter. Comparison of these curves to a dose‐response curve for hydrogen chloride showed that both the first and second weight loss fraction of plasticized poly(vinyl chloride) were more potent than hydrogen chloride in terms of sensory irritation. From these dose‐response relationships qualitative and quantitative predictions of human responses to the thermal decomposition products of plasticized.
Effect of the nature of fuel on the characteristics of fully developed compartment fires
Authors: Harmathy T. Z. 
Published: May 2005

AbstractThe coupling between the constituent reactions of a burning process, namely pyrolysis, combustion of volatiles, and (possibly) oxidation of char, is on the whole quite different for fires occurring in the open and for those that develop in an enclosure. Consequently, knowledge of the characteristics of free burning fires is of only limited value in studies related to compartment fire. Since the singe‐rout communication between the fire compartment and its environment, always assumed in classical fire studies, is not at all common in real world fires, great sophistication in the mathematical modeling of classical fires is rarely warranted. An examination of pool‐like fires and pile fires of noncharring fuels has shown that the severity of such fires in the fire compartment, as characterized by the so‐called ‘fire severity product’, decreases slightly with an increase in ventilation. The principal danger presented by these fires, however, is not so much to the fire compartment itself as to the surrounding spaces.An interesting feature of fires involving charring fuels, cellulosies in particular, is that the rate of consumption of fuel, the so‐called ‘rate of burning’, is practically independent of all process variables except ventilation. The severity of fires of cellulosics is, as a rule, much higher than that of fires of noncharring fuels. It exhibits a maximum at relatively low ventilations. From the point of view of spread of fire to the surrounding spaces, cellulosics are generally less dangerous than noncharring plastics. Fires involving cellulosics mixed with smaller amounts of noncharring plastics can be characterized as basically cellulosics fires, with a superimposed initial period of very high spread liability.
Ceiling heat transfer during fire plume and fire impingement
Authors: You H. Z. , Faeth G. M. 
Published: May 2005

AbstractThe impingement of turbulent fires and fire plumes on a horizontal ceiling was considered. Free flame heights, impinging flame lengths along the ceiling and ceiling heat fluxes were measured for both unconfined and confined ceilings. The study was limited to the initial stage of ceiling heating by fire under conditions where convection dominates the flow. Fire sources were simulated by burning liquid methanol, ethanol, 1‐propanol or n‐pentane from the top surface of a cylindrical wick. Test variables include fire heat release rate of 50–7890 W, ceiling diameters of 610 and 660 mm, ceiling heights of 58–940 mm, wick diameters of 10–107 mm and curtain wall lengths (for confined ceilings) as large as the ceiling height. Simplified models were employed to suggest expressions for data correlation. Flame lengths increased up to 40% when the ceiling was confined. Ceiling heat fluxes were relatively independent of position in the stagnation region (radius along ceiling <20% of the ceiling height). Heat fluxes in the stagnation region for plumes were 25–40% of those measured for impinging jets at comparable conditions. In the ceiling jet region, at larger distances from the point of impingement, the heat flux decreased with increasing radius, in agreement with other studies. Confinement tended to increase ceiling heat fluxes in both regions. Ceiling heat fluxes for impinging flames and plumes were approximately the same, for flame lengths along the ceiling up to 25% of the ceiling height; however, stagnation point heat fluxes decreased for longer flame lengths.
Smoke problems in buildings on fire: A TNO research project
Authors: Van Dijk H. A. L. , Twilt L. , Zorgman H. 
Published: May 2005

AbstractThe activities within the framework of TNO's research project on smoke problems in buildings on fire are reviewed. Two aspects will be dealt with extensively: smoke production and smoke movement. Furthermore, possible application of its finding will be discussed. The article reflects the state of the art at the end of 1978. In the meantime, the research programme has been concluded.
Measuring the leakage of door assemblies during standard fire exposures
Authors: Cooper Leonard Y. 
Published: May 2005

AbstractThe results of applying the tentative, high temperature, International Standards Organization test methods DP 5925 Part 3, which was developed to measure smoke leakage of door assemblies during the course of a standard fire endurance test, are reported. A critical analysis reveals that the basic objective of the test method is limited in its utility in that fire scenarios in high‐rise buildings may not be adequately simulated. Independent of this limitation, the analysis then identifies certain theoretical problems with the test method and its procedures. These lead to a conclusion that the test method is not generally reliable. An alternative test concept which appears to remove this limitation and all of its problems is described, and its development is advocated.
The thermal behaviour of lignins modified by chlorophosphazenes
Authors: Struszczyk Henryk 
Published: May 2005

AbstractThe thermal behaviour in air of lignins modified by chlorophosphazenes as well as that of the raw materials of lignins has been investigated using thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). The thermogravimetry and derivative thermogravimetry studies of lignins modified by chlorophosphazenes have shown their thermal resistance to be relatively higher than that of the intital raw materials of lignins in concrete kraft lignin and sodium ligninosulfonate. The differential thermal studies have demonstrated that the thermal degradation of products investigated takes place via exothermic processes. The lignins modified by chlorophosphazenes have been shown to be thermal and flame‐resistant materials.
Correlations between four radiant panel tests used to classify the fire behaviour of floor coverings in the EC
Authors: Téphany H. , Martin J. 
Published: May 2005

AbstractTests related to reaction to fire of materials are different from one country to another in the EC, as are test‐based classifications. There is no valid equivalence between the classifications of materials. We examine another approach, which is to propose acceptance of materials for a specific application on the basis of the results recorded in tests performed in another country through correlation between data recorded in tests. This new approach is applied here to four tests using radiant panels for floor covering classifications in Belgium, France. West Germany and Italy. This report is based on the results recorded on fifteen materials in the four tests. The conclusion is that the researched correlation is good.
Rates of heat and smoke release of wood in an ohio state university calorimeter
Authors: Tran Hao C. 
Published: May 2005

AbstractParticleboard, Douglas fir plywood and red oak were tested for heat and smoke release rates under different heat flux levels, piloted and unpiloted conditions, and vertical and horizontal orientations in an Ohio State University calorimeter. The chamber was instrumented to obtain heat release data by both the standard thermal and oxygen consumption methods simultaneously. Heat and smoke release data obtained by both methods are reported. The heat release rates by the thermal method are consistently lower than those by the oxygen consumption method. Variability in results is consistently lower using the oxygen consumption method. The heats of combustion calculated by oxygen consumption are close to those calculated from measurements with the oxygen bomb. The heat release rates measured on particleboard using the standard thermal method are in agreement with measurements on the same material in other Ohio State University calorimeters.