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Sample records for two-dimensional electrophoretic protein

  1. Two-dimensional electrophoretic analysis of nuclear matrix proteins in human colon adenocarcinoma.

    Science.gov (United States)

    Toumpanaki, A; Baltatzis, G E; Gaitanarou, E; Seretis, E; Toumpanakis, C; Aroni, K; Kittas, Christos; Voloudakis-Baltatzis, I E

    2009-01-01

    The aim of the present study was to observe possible qualitative and quantitative expression differences between nuclear matrix proteins (NMPs) of human colon adenocarcinoma and their mirror biopsies, using the technique of two-dimensional gel electrophoresis, in order to identify the existence of specific NMP fingerprints for colon cancer. Colon tissues were examined ultrastructurally and NMPs were isolated biochemically, by serial extraction of lipids, soluble proteins, DNA, RNA, and intermediate filaments and were separated according to their isoelectric point (pI) and their molecular weight (MW) by high-resolution two-dimensional electrophoresis (2D). By comparing the 2D electropherograms of colon cancer tissues and mirror biopsy tissues we observed qualitative and quantitative expression differences between their NMPs but also a differentiation of NMP composition between the stages of malignancy. Moreover, despite the similarities between mirror biopsy samples, a highlight percentage of exception was observed. Electrophoretic results provided in this study demonstrated that the examined NMPs could be further investigated as potential markers for detection of colorectal cancer in an early stage, for the assessment of the disease progression, as well as useful tools for individual therapy and for preventing a possible recurrence of cancer and metastasis.

  2. Three-dimensional fluorescence analysis of chernozem humic acids and their electrophoretic fractions

    Science.gov (United States)

    Trubetskoi, O. A.; Trubetskaya, O. E.

    2017-09-01

    Polyacrylamide gel electrophoresis in combination with size-exclusion chromatography (SEC-PAGE) has been used to obtain stable electrophoretic fractions of different molecular size (MS) from chernozem humic acids (HAs). Three-dimensional fluorescence charts of chernozem HAs and their fractions have been obtained for the first time, and all fluorescence excitation-emission maxima have been identified in the excitation wavelength range of 250-500 nm. It has been found that fractionation by the SEC-PAGE method results in a nonuniform distribution of protein- and humin-like fluorescence of the original HA preparation among the electrophoretic fractions. The electrophoretic fractions of the highest and medium MSs have only the main protein-like fluorescence maximum and traces of humin-like fluorescence. In the electrophoretic fraction of the lowest MS, the intensity of protein-like fluorescence is low, but the major part of humin-like fluorescence is localized there. Relationships between the intensity of protein-like fluorescence and the weight distribution of amino acids have been revealed, as well as between the degree of aromaticity and the intensity of humin-like fluorescence in electrophoretic fractions of different MSs. The obtained relationships can be useful in the interpretation of the spatial structural organization and ecological functions of soil HAs.

  3. Suitability of two-dimensional electrophoretic protein separations for quantitative detection of mutations

    International Nuclear Information System (INIS)

    Taylor, J.; Anderson, N.L.; Anderson, N.G.; Gemmell, A.; Giometti, C.S.; Nance, S.L.; Tollaksen, S.L.

    1986-01-01

    Separation of proteins by two-dimensional electrophoresis (2DE) provides a powerful method for mutagenesis studies, since hundreds of proteins can be monitored simultaneously. In previous mutation studies in which 2DE has been used, only qualitative protein differences were monitored; quantitative protein variations were not evaluated. Although significant differences in protein abundance can be detected by eye, the large number of protein spots present in 2DE patterns together with the large number of individual patterns required for a mutagenesis study would necessitate the use of a computerized analysis system to detect the rare quantitative protein changes indicative of gene deletions or inactivation of genes by point mutations in regulatory genes. A pilot study to search for heritable mutations induced by treatment of mice with either ethylnitrosourea or gamma radiation is underway. Samples are being monitored for quantitative changes that reduce the amount of protein by about 50%. The results of this study indicate that the key methods to improve the application of 2DE to mutation screening are to increase the number of measurable spots (i.e., improve stain sensitivity) and to decrease the spread of values for the volume measurements. Even small improvements in these areas could greatly increase the number of monitorable spots. 9 refs., 4 figs

  4. Simplification and improvement of protein detection in two-dimensional electrophoresis gels with SERVA HPE™ lightning red.

    Science.gov (United States)

    Griebel, Anja; Obermaier, Christian; Westermeier, Reiner; Moche, Martin; Büttner, Knut

    2013-07-01

    A new fluorescent amino-reactive dye has been tested for both labelling proteins prior to electrophoretic separations and between the two steps of two-dimensional electrophoresis. A series of experiments showed, that the labelling of lysines with this dye is compatible with all standard additives used for sample preparation, including reducing substances and carrier ampholytes. Using this dye for pre-labelling considerably simplifies the electrophoresis and detection workflow and provides highly sensitive and quantitative visualisation of proteins.

  5. Problems with multiple use of transfer buffer in protein electrophoretic transfer.

    Science.gov (United States)

    Dorri, Yaser; Kurien, Biji T; Scofield, R Hal

    2010-04-01

    Two-dimensional gel electrophoresis (2DE) and SDS-PAGE are the two most useful methods in protein separation. Proteins separated by 2DE or SDS-PAGE are usually transferred to membranes using a variety of methods, such as electrophoretic transfer, heat-mediated transfer, or nonelectrophoretic transfer, for specific protein detection and/or analysis. In a recent study, Pettegrew et al. claim to reuse transfer buffer containing methanol for at least five times for transferring proteins from SDS-PAGE to polyvinylidene difluoride. They add 150-200 ml fresh transfer solution each time for extended use as a result of loss of transfer buffer. Finally, they test efficiency of each protein transfer by chemiluminescence detection. Here, we comment on this report, as we believe this method is not accurate and useful for protein analysis, and it can cause background binding as well as inaccurate protein analysis.

  6. Electrophoretic transfer protein zymography.

    Science.gov (United States)

    Pan, Daniel; Hill, Adam P; Kashou, Anthony; Wilson, Karl A; Tan-Wilson, Anna

    2011-04-15

    Zymography detects and characterizes proteolytic enzymes by electrophoresis of protease-containing samples into a nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel containing a copolymerized protein substrate. The usefulness of zymography for molecular weight determination and proteomic analysis is hampered by the fact that some proteases exhibit slower migration through a gel that contains substrate protein. This article introduces electrophoretic transfer protein zymography as one solution to this problem. In this technique, samples containing proteolytic enzymes are first resolved in nonreducing SDS-PAGE on a gel without protein substrate. The proteins in the resolving gel are then electrophoretically transferred to a receiving gel previously prepared with a copolymerized protein substrate. The receiving gel is then developed as a zymogram to visualize clear or lightly stained bands in a dark background. Band intensities are linearly related to the amount of protease, extending the usefulness of the technique so long as conditions for transfer and development of the zymogram are kept constant. Conditions of transfer, such as the pore sizes of resolving and receiving gels and the transfer time relative to the molecular weight of the protease, are explored. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Two Dimensional Electrophoresis of Galactosidase Relating to the Disappearance of Bombyx Lectin Activity

    OpenAIRE

    カトウ, ヤスオ; Yasuo, Kato

    2004-01-01

    "Two dimensional polyacrylamide gel electroporesis (2 D-PAGE) analysis on the haemolymph of Bombyx mori was performed using the Mini-PROTEAN mini tube gel two dimensional polyacrylamide gel electrophoresis system (Bio-Rad Laboratories, Inc.). The result on various electrophoretical conditions using the haemolymph-protein showed the possibility that the haemolymph-protein was separated actually by means of this method. Moreover, the result of 2 D-PAGE analysis on Fraction II obtained by gel fi...

  8. Correlation of acidic and basic carrier ampholyte and immobilized pH gradient two-dimensional gel electrophoresis patterns based on mass spectrometric protein identification

    DEFF Research Database (Denmark)

    Nawrocki, A; Larsen, Martin Røssel; Podtelejnikov, A V

    1998-01-01

    Separation of proteins on either carrier ampholyte-based or immobilized pH gradient-based two-dimensional (2-D) gels gives rise to electrophoretic patterns that are difficult to compare visually. In this paper we have used matrix-assisted laser desorption/ionization mass spectrometry (MALDI......-MS) to determine the identities of 335 protein spots in these two 2-D gel systems, including a substantial number of basic proteins which had never been identified before. Proteins that were identified in both gel systems allowed us to cross-reference the gel patterns. Vector analysis of these cross...

  9. Proteomic study of muscle sarcoplasmic proteins using AUT-PAGE/SDS-PAGE as two-dimensional gel electrophoresis.

    Science.gov (United States)

    Picariello, Gianluca; De Martino, Alessandra; Mamone, Gianfranco; Ferranti, Pasquale; Addeo, Francesco; Faccia, Michele; Spagnamusso, Salvatore; Di Luccia, Aldo

    2006-03-20

    In the present study, an alternative procedure for two-dimensional (2D) electrophoretic analysis in proteomic investigation of the most represented basic muscle water-soluble proteins is suggested. Our method consists of Acetic acid-Urea-Triton polyacrylamide gel (AUT-PAGE) analysis in the first dimension and standard sodium dodecyl sulphate polyacrylamide gel (SDS-PAGE) in the second dimension. Although standard two-dimensional Immobilized pH Gradient-Sodium Dodecyl-Sulphate (2D IPG-SDS) gel electrophoresis has been successfully used to study these proteins, most of the water-soluble proteins are spread on the alkaline part of the 2D map and are poorly focused. Furthermore, the similarity in their molecular weights impairs resolution of the classical approach. The addition of Triton X-100, a non-ionic detergent, into the gel induces a differential electrophoretic mobility of proteins as a result of the formation of mixed micelles between the detergent and the hydrophobic moieties of polypeptides, separating basic proteins with a criterion similar to reversed phase chromatography based on their hydrophobicity. The acid pH induces positive net charges, increasing with the isoelectric point of proteins, thus allowing enhanced resolution in the separation. By using 2D AUT-PAGE/SDS electrophoresis approach to separate water-soluble proteins from fresh pork and from dry-cured products, we could spread proteins over a greater area, achieving a greater resolution than that obtained by IPG in the pH range 3-10 and 6-11. Sarcoplasmic proteins undergoing proteolysis during the ripening of products were identified by Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-ToF) mass spectrometry peptide mass fingerprinting in a easier and more effective way. Two-dimensional AUT-PAGE/SDS electrophoresis has allowed to simplify separation of sarcoplasmic protein mixtures making this technique suitable in the defining of quality of dry-cured pork products by immediate

  10. Electrophoretic analysis of proteins from Mycoplasma hominis strains detected by SDS-PAGE, two-dimensional gel electrophoresis and immunoblotting

    DEFF Research Database (Denmark)

    Andersen, H; Birkelund, Svend; Christiansen, Gunna

    1987-01-01

    The proteins of 14 strains of Mycoplasma hominis were compared by SDS-PAGE in gradient gels, by two-dimensional (2D) gel electrophoresis of extracts of 35S-labelled cells and by immunoblot analysis of cell proteins. The strains examined included the M. hominis type strain PG21 and 13 others...... isolated variously from genital tract, mouth, blood, upper urinary tract and a wound. These 14 strains shared 76-99% of proteins in SDS-gradient gel analysis and 41-72% in the 2D gels. As expected, the immunoblot analysis likewise revealed the existence of an extensive common protein pattern in M. hominis...

  11. Two-dimensional analysis of human lymphocyte proteins. III. Preliminary report on a marker for the early detection and diagnosis of infectious mononucleosis

    International Nuclear Information System (INIS)

    Willard, K.E.

    1982-01-01

    Two-dimensional gel electrophoretic patterns of human peripheral blood leukocytes from 12 patients with infectious mononucleosis were prepared by use of the ISO-DALT system. Before the two-dimensional separation, the leukocytes were purified by Ficoll-Paque gradient centrifugation and labeled overnight with [ 35 S] methionine. Quantitative increases in two proteins were detected in the patterns of infected leukocytes from the patients as compared with controls. Fluorescence-activated cell sorting of leukocytes from normal human peripheral blood before subsequent two-dimensional gel analysis revealed that the dramatic increase in one of these proteins (Inmono:2) could be due to shifts in the population ratios of lymphocytes, monocytes, and granulocytes. In contrast, the appearance in the infected leukocytes of a second protein, Inmono:1, could not be accounted for by cell-population shifts. Increased amounts of these two proteins have been found in every patient studied who had clinically detectable infectious mononucleosis. In addition, a patient who displayed symptoms of infectious mononucleosis but who did not have a positive result in the MONOSPOT test (Ortho) until three weeks after our analysis also demonstrated increased relative amounts of these proteins in his leukocyte pattern

  12. Electrophoretic Detection and Confocal Microscopic Imaging of Tyrosine Nitrated Proteins in Plant Tissue.

    Science.gov (United States)

    Arora, Dhara; Singh, Neha; Bhatla, Satish C

    2018-01-01

    Tyrosine nitrated proteins can be detected in plant cells electrophoretically and their distribution can be monitored by confocal laser scanning microscopy (CLSM) imaging. One-dimensional polyacrylamide gel electrophoresis (1D PAGE) followed by Western blotting using polyclonal antibody against 3-nitrotyrosine residues enables detection of tyrosine nitrated proteins in plant cells. Here we describe detection of tyrosine nitrated proteins in the homogenates derived from sunflower (Helianthus annuus L.) seedling cotyledons. Total soluble proteins obtained from tissue homogenates are resolved using vertical gel electrophoresis followed by their electrophoretic transfer on to a microporous membrane support for immunodetection. Spatial distribution of tyrosine nitrated proteins can be visualized using an antibody against 3-nitrotyrosine residues. Immunofluorescent localization is performed by cutting 7 μm thick wax sections of tissue followed by incubation in primary anti-nitrotyrosine antibody (dilution 1:200) and secondary Cy-3 labeled anti-rabbit IgG antibody (dilution 1:1500). Confocal laser scanning microscopy analysis is undertaken using argon lasers (ex: 530-550 nm and em: 570 nm) at pinhole 1. Modulation in the abundance and spatial localization of tyrosine nitrated proteins in plant tissues can be monitored using these techniques.

  13. Electrophoretic detection of protein p53 in human leukocytes

    International Nuclear Information System (INIS)

    Paponov, V.D.; Kupsik, E.G.; Shcheglova, E.G.; Yarullin, N.N.

    1986-01-01

    The authors have found an acid-soluble protein with mol. wt. of about 53 kD in peripheral blood leukocytes of persons with Down's syndrome. It was present in different quantities in all 20 patients tested, but was virtually not discovered in 12 healthy blood donors. This paper determines the possible identity of this protein with protein p53 from mouse ascites carcinoma by comparing their electrophoretic mobilities, because the accuracy of electrophoretic determination of the molecular weight of proteins is not sufficient to identify them. The paper also describes experiments to detect a protein with electrophoretic mobility identical with that of a protein in the leukocytes of patients with Down's syndrome in leukocytes of patients with leukemia. To discover if protein p53 is involved in cell proliferation, the protein composition of leukocytes from healthy blood donors, cultured in the presence and absence of phytohemagglutinin (PHA), was compared. Increased incorporation of H 3-thymidine by leukocytes of patients with Down's syndrome is explained by the presence of a population of immature leukocytes actively synthesizing DNA in the peripheral blood of these patients, and this can also explain the presence of protein p53 in the leukocytes of these patients

  14. A genetic electrophoretic variant of high-sulfur hair proteins for forensic hair comparisons. I. Characterization of variant high-sulfur proteins of human hair.

    Science.gov (United States)

    Miyake, B

    1989-02-01

    In a survey of the proteins from human hair, a genetic electrophoretic variant has been observed in the high-sulfur protein region. S-carboxymethylated proteins were examined by 15% polyacrylamide gel electrophoresis at pH 8.9. Out of 150 unrelated samples of Japanese head hairs analyzed, 107 showed 6 major high-sulfur protein bands (normal) and the remaining 43 samples showed an additional high-sulfur protein band (variant). Of 21 Caucasian samples analyzed only one variant sample was found. Characterization of the proteins by two-dimensional electrophoresis evidenced a variant protein spot which showed an apparent molecular weight of 30 k Da. Isoelectric points of the high-sulfur proteins ranged from 3.25-3.55 and that of variant protein band from 3.3-3.4. Family studies of 21 matings resulting in 49 children indicated that this variant was inherited in an autosomal fashion.

  15. Molecular phylogeny of the hominoid primates as indicated by two-dimensional protein electrophoresis

    International Nuclear Information System (INIS)

    Goldman, D.; Giri, P.R.; O'Brien, J.O.

    1987-01-01

    A molecular phylogeny for the hominoid primates was constructed by using genetic distances from a survey of 383 radiolabeled fibroblast polypeptides resolved by two-dimensional electrophoresis (2DE). An internally consistent matrix of Nei genetic distances was generated on the basis of variants in electrophoretic position. The derived phylogenetic tree indicated a branching sequence, from oldest to most recent, of cercopithecoids (Macaca fascicularis), gibbon-siamang, orangutan, gorilla, and human-chimpanzee. A cladistic analysis of 240 electrophoretic characters that varied between ape species produced an identical tree. Genetic distance measures obtained by 2DE are largely consistent with those generated by other molecular procedures. In addition, the 2DE data set appears to resolve the human-chimpanzee-gorilla trichotomy in favor of a more recent association of chimpanzees and humans

  16. Binding Direction-Based Two-Dimensional Flattened Contact Area Computing Algorithm for Protein-Protein Interactions.

    Science.gov (United States)

    Kang, Beom Sik; Pugalendhi, GaneshKumar; Kim, Ku-Jin

    2017-10-13

    Interactions between protein molecules are essential for the assembly, function, and regulation of proteins. The contact region between two protein molecules in a protein complex is usually complementary in shape for both molecules and the area of the contact region can be used to estimate the binding strength between two molecules. Although the area is a value calculated from the three-dimensional surface, it cannot represent the three-dimensional shape of the surface. Therefore, we propose an original concept of two-dimensional contact area which provides further information such as the ruggedness of the contact region. We present a novel algorithm for calculating the binding direction between two molecules in a protein complex, and then suggest a method to compute the two-dimensional flattened area of the contact region between two molecules based on the binding direction.

  17. Procedures for two-dimensional electrophoresis of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Tollaksen, S.L.; Giometti, C.S.

    1996-10-01

    High-resolution two-dimensional gel electrophoresis (2DE) of proteins, using isoelectric focusing in the first dimension and sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) in the second, was first described in 1975. In the 20 years since those publications, numerous modifications of the original method have evolved. The ISO-DALT system of 2DE is a high-throughput approach that has stood the test of time. The problem of casting many isoelectric focusing gels and SDS-PAGE slab gels (up to 20) in a reproducible manner has been solved by the use of the techniques and equipment described in this manual. The ISO-DALT system of two-dimensional gel electrophoresis originated in the late 1970s and has been modified many times to improve its high-resolution, high-throughput capabilities. This report provides the detailed procedures used with the current ISO-DALT system to prepare, run, stain, and photograph two-dimensional gels for protein analysis.

  18. Two-dimensional polyacrylamide gel electrophoresis of intracellular proteins

    International Nuclear Information System (INIS)

    Ojima, N.; Sakamoto, T.; Yamashita, M.

    1996-01-01

    Since two-dimensional electrophoresis was established by O'Farrell for analysis of intracellular proteins of Escherichia coli, it has been applied to separation of proteins of animal cells and tissues, and especially to identification of stress proteins. Using this technique, proteins are separated by isoelectric focusing containing 8 m urea in the first dimension and by SDS-PAGE in the second dimension. The gels are stained with Coomassie Blue R-250 dye, followed by silver staining. In the case of radio-labeled proteins, the gels are dried and then autoradiographed. In order to identify a specific protein separated by two-dimensional electrophoresis, a technique determining the N-terminal amino acid sequence of the protein has been developed recently. After the proteins in the gel were electrotransferred to a polyvinylidene difluoride membrane, the membrane was stained for protein with Commassie Blue and a stained membrane fragment was applied to a protein sequencer. Our recent studies demonstrated that fish cells newly synthesized various proteins in response to heat shock, cold nd osmotic stresses. For example, when cellular proteins extracted from cold-treated rainbow trout cells were subjected to two-dimensional gel electrophoresis, the 70 kDa protein was found to be synthesized during the cold-treatment. N-Terminal sequence analysis showed that the cold-inducible protein was a homolog of mammalian valosin-containing protein and yeast cell division cycle gene product CDC48p. Furthermore, the sequence data were useful for preparing PCR primers and a rabbit antibody against a synthetic peptide to analyze a role for the protein in the function of trout cells and mechanisms for regulation

  19. Comparison of serum protein electrophoretic pattern in cows and small ruminants

    Directory of Open Access Journals (Sweden)

    Oskar Nagy

    2015-01-01

    Full Text Available Determination of the physiological electrophoretic patterns in animals is very useful for clinicians in diagnosing healthy and sick animals. The objective of this study was to investigate the serum protein electrophoretic pattern in cows, sheep, and goats in order to evaluate the differences in the size and number of protein fractions between the evaluated ruminant species. Ten adult multiparous high-yielding dairy cows, 10 adult female sheep and 10 adult female goats were included in this study. All the evaluated animals were clinically healthy. Serum was analyzed for total serum protein concentrations, and for the relative and absolute values of protein fractions with calculation of albumin/globulin ratios. Serum protein fractions were separated by zone electrophoresis on buffered agarose gel. Serum protein electrophoresis identified 6 distinct bands, comprising albumin, alpha1- (α1, alpha2- (α2, beta1- (β1, beta2- (β2, and gamma- (γ globulins in cows. In sheep, serum proteins exhibited 6 fractions: albumin, α1-, α2-, β-, γ1- and γ2-globulins. In goats, serum proteins were separated into 5 fractions: albumin, α1-, α2-, β- and γ-globulins. Significant differences in the relative as well as absolute means were found for the albumin/globulin ratio and most of the protein fractions, except γ-globulins. No significant differences were found in the concentration of total proteins. These results describe the marked species differences in most of serum protein fractions between the evaluated groups of animals, and contribute to the current knowledge about the physiological electrophoretic pattern of serum proteins in ruminants, which can be used for diagnostic purposes.

  20. High-resolution slab gel isoelectric focusing: methods for quantitative electrophoretic transfer and immunodetection of proteins as applied to the study of the multiple isoelectric forms of ornithine decarboxylase.

    Science.gov (United States)

    Reddy, S G; Cochran, B J; Worth, L L; Knutson, V P; Haddox, M K

    1994-04-01

    A high-resolution isoelectric focusing vertical slab gel method which can resolve proteins which differ by a single charge was developed and this method was applied to the study of the multiple isoelectric forms of ornithine decarboxylase. Separation of proteins at this high level of resolution was achieved by increasing the ampholyte concentration in the gels to 6%. Various lots of ampholytes, from the same or different commercial sources, differed significantly in their protein binding capacity. Ampholytes bound to proteins interfered both with the electrophoretic transfer of proteins from the gel to immunoblotting membranes and with the ability of antibodies to interact with proteins on the immunoblotting membranes. Increasing the amount of protein loaded into a gel lane also decreased the efficiency of the electrophoretic transfer and immunodetection. To overcome these problems, both gel washing and gel electrophoretic transfer protocols for disrupting the ampholyte-protein binding and enabling a quantitative electrophoretic transfer of proteins were developed. Two gel washing procedures, with either thiocyanate or borate buffers, and a two-step electrophoretic transfer method are described. The choice of which method to use to optimally disrupt the ampholyte-protein binding was found to vary with each lot of ampholytes employed.

  1. Femtosecond X-ray diffraction from two-dimensional protein crystals

    Directory of Open Access Journals (Sweden)

    Matthias Frank

    2014-03-01

    Full Text Available X-ray diffraction patterns from two-dimensional (2-D protein crystals obtained using femtosecond X-ray pulses from an X-ray free-electron laser (XFEL are presented. To date, it has not been possible to acquire transmission X-ray diffraction patterns from individual 2-D protein crystals due to radiation damage. However, the intense and ultrafast pulses generated by an XFEL permit a new method of collecting diffraction data before the sample is destroyed. Utilizing a diffract-before-destroy approach at the Linac Coherent Light Source, Bragg diffraction was acquired to better than 8.5 Å resolution for two different 2-D protein crystal samples each less than 10 nm thick and maintained at room temperature. These proof-of-principle results show promise for structural analysis of both soluble and membrane proteins arranged as 2-D crystals without requiring cryogenic conditions or the formation of three-dimensional crystals.

  2. Enhanced detergent extraction for analysis of membrane proteomes by two-dimensional gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Hsu Kimberly K

    2005-06-01

    Full Text Available Abstract Background The analysis of hydrophobic membrane proteins by two-dimensional gel electrophoresis has long been hampered by the concept of inherent difficulty due to solubility issues. We have optimized extraction protocols by varying the detergent composition of the solubilization buffer with a variety of commercially available non-ionic and zwitterionic detergents and detergent-like phospholipids. Results After initial analyses by one-dimensional SDS-PAGE, quantitative two-dimensional analyses of human erythrocyte membranes, mouse liver membranes, and mouse brain membranes, extracted with buffers that included the zwitterionic detergent MEGA 10 (decanoyl-N-methylglucamide and the zwitterionic lipid LPC (1-lauroyl lysophosphatidylcholine, showed selective improvement over extraction with the common 2-DE detergent CHAPS (3 [(3-cholamidopropyldimethylammonio]-1-propanesulfonate. Mixtures of the three detergents showed additive improvements in spot number, density, and resolution. Substantial improvements in the analysis of a brain membrane proteome were observed. Conclusion This study demonstrates that an optimized detergent mix, coupled with rigorous sample handling and electrophoretic protocols, enables simple and effective analysis of membrane proteomes using two-dimensional electrophoresis.

  3. Finding the "bio" in biobased products: electrophoretic identification of wheat proteins in processed products.

    Science.gov (United States)

    Robertson, George H; Hurkman, William J; Cao, Trung K; Tanaka, Charlene K; Orts, William J

    2010-04-14

    Verification of the biocontent in biobased or "green" products identifies genuine products, exposes counterfeit copies, supports or refutes content claims, and ensures consumer confidence. When the biocontent includes protein, elemental nitrogen analysis is insufficient for verification since non-protein, but nitrogen-rich, content also may be present. However, the proteins can be extracted, separated by electrophoretic methods, and detected by UV absorption, protein stain, or immunoblotting. We utilized capillary zone electrophoresis (CZE) to separate proteins in a gliadin fraction that had been dissolved in aqueous ethanol (70%) and polyacrylamide gel electrophoresis (PAGE) to separate proteins in a gliadin-plus-glutenin fraction that had been dissolved in water containing both sodium dodecyl sulfate (SDS) and a reducing agent, dithiothreitol (DTT). We sought to verify the presence of these wheat grain proteins in wheat bread, a wheat flake cereal, wheat beer, and an enclosure for an antique automobile ignition coil reputed to contain wheat gluten. Proteins extracted from commercial wheat, corn, and soy flours served as standards, and proteins from heat-altered wheat served as process condition references. This approach successfully identified wheat proteins in these products especially if the process temperature did not exceed 120 degrees C. Above this temperature attenuation was nearly complete for proteins analyzed by CZE, but wheat-like patterns could still be recognized by one- and two-dimensional PAGE. Immunoblots reacted with grain-specific antibodies confirmed the identities of the cereal component especially when the protein pattern was greatly altered by thermal modification, specific protein adsorption, or protein digestion. In addition to verifying that wheat proteins are present, the complementary use of these methods can reveal whether whole wheat gluten or merely an alcohol-soluble fraction had been used in the specific product and indicate the

  4. Binding Direction-Based Two-Dimensional Flattened Contact Area Computing Algorithm for Protein–Protein Interactions

    Directory of Open Access Journals (Sweden)

    Beom Sik Kang

    2017-10-01

    Full Text Available Interactions between protein molecules are essential for the assembly, function, and regulation of proteins. The contact region between two protein molecules in a protein complex is usually complementary in shape for both molecules and the area of the contact region can be used to estimate the binding strength between two molecules. Although the area is a value calculated from the three-dimensional surface, it cannot represent the three-dimensional shape of the surface. Therefore, we propose an original concept of two-dimensional contact area which provides further information such as the ruggedness of the contact region. We present a novel algorithm for calculating the binding direction between two molecules in a protein complex, and then suggest a method to compute the two-dimensional flattened area of the contact region between two molecules based on the binding direction.

  5. Structural organization of the human glucocorticoid receptor determined by one- and two-dimensional gel electrophoresis of proteolytic receptor fragments

    International Nuclear Information System (INIS)

    Smith, A.C.; Harmon, J.M.

    1987-01-01

    The structural organization of the steroid-binding protein of the IM-9 cell glucocorticoid receptor was investigated by using one- and two-dimensional gel electrophoresis of proteolytic receptor fragments. One-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of receptor fragments isolated after trypsin digestion of immunopurified [ 3 H]dexamethasone 21-mesylate ([ 3 H]DM-) labeled receptor revealed the presence of a stable 26.5-kilodalton (kDa) steroid-containing non-DNA-binding fragment, derived from a larger, less stable, 29-kDa fragment. The 26.5-kDa tryptic fragment appeared to be completely contained within a 41-kDa, steroid-containing, DNA-binding species isolated after chymotrypsin digestion of the intact protein. Two-dimensional electrophoretic analysis of the [ 3 H]DM-labeled tryptic fragments resolved two 26.5-kDa and two 29-kDa components. This was the same number of isoforms seen in the intact protein, indicating that the charge heterogeneity of the steroid-binding protein is the result of modification within the steroid-containing, non-DNA-binding, 26.5-kDa tryptic fragment. Two-dimensional analysis of the 41-kDa [ 3 H]DM-labeled chymotryptic species revealed a pattern of isoforms more complex than that seen either in the intact protein or in the steroid-containing tryptic fragments. These results suggest that the 41-kDa [ 3 H]DM-labeled species resolved by one-dimensional SDS-PAGE after chymotrypsin digestion may be composed of several distinct proteolytic fragments

  6. Application of Fluorescence Two-Dimensional Difference In-Gel Electrophoresis as a Proteomic Biomarker Discovery Tool in Muscular Dystrophy Research

    Science.gov (United States)

    Carberry, Steven; Zweyer, Margit; Swandulla, Dieter; Ohlendieck, Kay

    2013-01-01

    In this article, we illustrate the application of difference in-gel electrophoresis for the proteomic analysis of dystrophic skeletal muscle. The mdx diaphragm was used as a tissue model of dystrophinopathy. Two-dimensional gel electrophoresis is a widely employed protein separation method in proteomic investigations. Although two-dimensional gels usually underestimate the cellular presence of very high molecular mass proteins, integral membrane proteins and low copy number proteins, this method is extremely powerful in the comprehensive analysis of contractile proteins, metabolic enzymes, structural proteins and molecular chaperones. This gives rise to two-dimensional gel electrophoretic separation as the method of choice for studying contractile tissues in health and disease. For comparative studies, fluorescence difference in-gel electrophoresis has been shown to provide an excellent biomarker discovery tool. Since aged diaphragm fibres from the mdx mouse model of Duchenne muscular dystrophy closely resemble the human pathology, we have carried out a mass spectrometry-based comparison of the naturally aged diaphragm versus the senescent dystrophic diaphragm. The proteomic comparison of wild type versus mdx diaphragm resulted in the identification of 84 altered protein species. Novel molecular insights into dystrophic changes suggest increased cellular stress, impaired calcium buffering, cytostructural alterations and disturbances of mitochondrial metabolism in dystrophin-deficient muscle tissue. PMID:24833232

  7. Advancements of two dimensional correlation spectroscopy in protein researches

    Science.gov (United States)

    Tao, Yanchun; Wu, Yuqing; Zhang, Liping

    2018-05-01

    The developments of two-dimensional correlation spectroscopy (2DCOS) applications in protein studies are discussed, especially for the past two decades. The powerful utilities of 2DCOS combined with various analytical techniques in protein studies are summarized. The emphasis is on the vibration spectroscopic techniques including IR, NIR, Raman and optical activity (ROA), as well as vibration circular dichroism (VCD) and fluorescence spectroscopy. In addition, some new developments, such as hetero-spectral 2DCOS, moving-window correlation, and model based correlation, are also reviewed for their utility in the investigation of the secondary structure, denaturation, folding and unfolding changes of protein. Finally, the new possibility and challenges of 2DCOS in protein research are highlighted as well.

  8. Protein electrophoretic migration data from custom and commercial gradient gels

    Directory of Open Access Journals (Sweden)

    Andrew J. Miller

    2016-12-01

    Full Text Available This paper presents data related to the article “A method for easily customizable gradient gel electrophoresis” (A.J. Miller, B. Roman, E.M. Norstrom, 2016 [1]. Data is presented on the rate of electrophoretic migration of proteins in both hand-poured and commercially acquired acrylamide gradient gels. For each gel, migration of 9 polypeptides of various masses was measured upon completion of gel electrophoresis. Data are presented on the migration of proteins within separate lanes of the same gel as well as migration rates from multiple gels.

  9. Human muscle proteins: analysis by two-dimensional electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Giometti, C.S.; Danon, M.J.; Anderson, N.G.

    1983-09-01

    Proteins from single frozen sections of human muscle were separated by two-dimensional gel electrophoresis and detected by fluorography or Coomassie Blue staining. The major proteins were identical in different normal muscles obtained from either sex at different ages, and in Duchenne and myotonic dystrophy samples. Congenital myopathy denervation atrophy, polymyositis, and Becker's muscular dystrophy samples, however, showed abnormal myosin light chain compositions, some with a decrease of fast-fiber myosin light chains and others with a decrease of slow-fiber light chains. These protein alterations did not correlate with any specific disease, and may be cause by generalized muscle-fiber damage.

  10. Consistent two-dimensional visualization of protein-ligand complex series

    Directory of Open Access Journals (Sweden)

    Stierand Katrin

    2011-06-01

    Full Text Available Abstract Background The comparative two-dimensional graphical representation of protein-ligand complex series featuring different ligands bound to the same active site offers a quick insight in their binding mode differences. In comparison to arbitrary orientations of the residue molecules in the individual complex depictions a consistent placement improves the legibility and comparability within the series. The automatic generation of such consistent layouts offers the possibility to apply it to large data sets originating from computer-aided drug design methods. Results We developed a new approach, which automatically generates a consistent layout of interacting residues for a given series of complexes. Based on the structural three-dimensional input information, a global two-dimensional layout for all residues of the complex ensemble is computed. The algorithm incorporates the three-dimensional adjacencies of the active site residues in order to find an universally valid circular arrangement of the residues around the ligand. Subsequent to a two-dimensional ligand superimposition step, a global placement for each residue is derived from the set of already placed ligands. The method generates high-quality layouts, showing mostly overlap-free solutions with molecules which are displayed as structure diagrams providing interaction information in atomic detail. Application examples document an improved legibility compared to series of diagrams whose layouts are calculated independently from each other. Conclusions The presented method extends the field of complex series visualizations. A series of molecules binding to the same protein active site is drawn in a graphically consistent way. Compared to existing approaches these drawings substantially simplify the visual analysis of large compound series.

  11. A new integrated statistical approach to the diagnostic use of two-dimensional maps.

    Science.gov (United States)

    Marengo, Emilio; Robotti, Elisa; Gianotti, Valentina; Righetti, Pier Giorgio; Cecconi, Daniela; Domenici, Enrico

    2003-01-01

    Two-dimensional (2-D) electrophoresis is a very useful technique for the analysis of proteins in biological tissues. The complexity of the 2-D maps obtained causes many difficulties in the comparison of different samples. A new method is proposed for comparing different 2-D maps, based on five steps: (i) the digitalisation of the image; (ii) the transformation of the digitalised map in a fuzzy entity, in order to consider the variability of the 2-D electrophoretic separation; (iii) the calculation of a similarity index for each pair of maps; (iv) the analysis by multidimensional scaling of the previously obtained similarity matrix; (v) the analysis by classification or cluster analysis techniques of the resulting map co-ordinates. The method adopted was first tested on some simulated samples in order to evaluate its sensitivity to small changes in the spots position and size. The optimal setting of the method parameters was also investigated. Finally, the method was successfully applied to a series of real samples corresponding to the electrophoretic bidimensional analysis of sera from normal and nicotine-treated rats. Multidimensional scaling allowed the separation of the two classes of samples without any misclassification.

  12. Frequency of electrophoretic changes consistent with feline infectious peritonitis in two different time periods (2004-2009 vs 2013-2014).

    Science.gov (United States)

    Stranieri, Angelica; Giordano, Alessia; Bo, Stefano; Braghiroli, Chiara; Paltrinieri, Saverio

    2017-08-01

    Objectives The aim of this study was to evaluate whether the frequency of electrophoretic changes in serum of cats with feline infectious peritonitis (FIP) changed in recent years vs past years. Methods Agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE) from cats with FIP and healthy cats recorded in the periods 2004-2009 and 2013-2014 were retrospectively analysed. Relative and absolute values of each electrophoretic fraction were recorded and the number of cats showing single or combined electrophoretic changes consistent with FIP (hypoalbuminaemia, inverted albumin to globulin [A:G] ratio, increased total protein, total globulin, alpha [α] 2 -globulin and gamma [γ]-globulin concentration) were counted. Additionally, a visual analysis of electrophoretograms was also performed. Results for the two time periods were statistically compared. Results The details of 91 AGE procedures (41 from cats with FIP and 50 from healthy cats) and 45 CZE procedures (26 from cats with FIP and 19 from healthy cats) were obtained from the database. No significant differences between the two time periods were found both in FIP and in healthy cats analysed with CZE and in healthy cats analysed with AGE. Compared with 2004-2009, cats with FIP sampled in 2013-2014 with AGE showed a significantly lower concentration of total protein, γ-globulins and total globulins, and a significantly higher A:G ratio and percentage of albumin and α 2 -globulins. Using both AGE and CZE, in recent years the proportion of cats with high α2-globulins without gammopathy and the proportion of cats with gammopathy alone decreased. With a visual approach, the number of patterns considered as dubious increased in the second period with AGE (non-statistically significant). Conclusions and relevance The frequency of electrophoretic abnormalities in cats with FIP decreased in recent years, independently of the technique employed. Although the mechanism responsible for this change was

  13. A two-dimensional electrophoretic profile of the proteins secreted by Herbaspirillum seropedicae strain Z78.

    Science.gov (United States)

    Chaves, Daniela Fojo Seixas; de Souza, Emanuel Maltempi; Monteiro, Rose Adele; de Oliveira Pedrosa, Fábio

    2009-11-02

    Herbaspirillum seropedicae is an endophytic bacterium that associates with rice, sugarcane and other economically important crops. Secreted proteins play a key role in the plant-bacterial interaction. Using 2D electrophoresis and peptide mass fingerprint mass spectrometry, 63 protein spots representing 41 different secreted proteins were identified during growth of H. seropedicae under nitrogen-sufficient conditions. In silico analysis showed that 25.4% of the proteins had signal peptides and 15.9% were predicted to be non-classically secreted. Among the most abundant were flagellar components and ABC-type transport system proteins. Nine secreted proteins had also been identified in the cellular proteome, suggesting that they also play a role in the extracellular environment. No type III secreted proteins were detected by comparison of the wild type strain with an hrcN mutant strain.

  14. Electrophoretic transport of biomolecules across liquid-liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Thomas; Hardt, Steffen [Center of Smart Interfaces, TU Darmstadt, Petersenstrasse 32, D-64287 Darmstadt (Germany); Muenchow, Goetz, E-mail: hardt@csi.tu-darmstadt.de [Institut fuer Mikrotechnik Mainz GmbH, Carl-Zeiss-Strasse 18-20, D-55129 Mainz (Germany)

    2011-05-11

    The mass transfer resistance of a liquid-liquid interface in an aqueous two-phase system composed of poly(ethylene glycol) and dextran is investigated. Different types of proteins and DNA stained with fluorescent dyes serve as probes to study the transport processes close to the interface. A microfluidic device is employed to enable the electrophoretic transport of biomolecules from one phase to another. The results obtained for proteins can be explained solely via the different electrophoretic mobilities and different affinities of the molecules to the two phases, without any indications of a significant mass transfer resistance of the liquid-liquid interface. By contrast, DNA molecules adsorb to the interface and only desorb under an increased electric field strength. The desorption process carries the signature of a thermally activated escape from a metastable state, as reflected in the exponential decay of the fluorescence intensity at the interface as a function of time.

  15. A Robust Identification of the Protein Standard Bands in Two-Dimensional Electrophoresis Gel Images

    Directory of Open Access Journals (Sweden)

    Serackis Artūras

    2017-12-01

    Full Text Available The aim of the investigation presented in this paper was to develop a software-based assistant for the protein analysis workflow. The prior characterization of the unknown protein in two-dimensional electrophoresis gel images is performed according to the molecular weight and isoelectric point of each protein spot estimated from the gel image before further sequence analysis by mass spectrometry. The paper presents a method for automatic and robust identification of the protein standard band in a two-dimensional gel image. In addition, the method introduces the identification of the positions of the markers, prepared by using pre-selected proteins with known molecular mass. The robustness of the method was achieved by using special validation rules in the proposed original algorithms. In addition, a self-organizing map-based decision support algorithm is proposed, which takes Gabor coefficients as image features and searches for the differences in preselected vertical image bars. The experimental investigation proved the good performance of the new algorithms included into the proposed method. The detection of the protein standard markers works without modification of algorithm parameters on two-dimensional gel images obtained by using different staining and destaining procedures, which results in different average levels of intensity in the images.

  16. Electrophoretic protein profiles of mid-sized copepod Calanoides patagoniensis steadily fed bloom-forming diatoms

    Directory of Open Access Journals (Sweden)

    Victor M Aguilera

    2015-09-01

    Full Text Available Recent field and experimental evidence collected in the southern upwelling region off Concepción (36°5'S, 73°3'W showed an abrupt reduction (<72 h in the egg production rates (EPR of copepods when they were fed steadily and solely with the local bloom-forming diatom Thalassiosira rotula. Because diatoms were biochemically similar to dinoflagellate Prorocentrum minimum, a diet which supported higher reproductive outcomes, the fecundity reduction observed in copepod females fed with the diatom may have obeyed to post-ingestive processes, giving rise to resources reallocation. This hypothesis was tested by comparing feeding (clearance and ingestion rates, reproduction (EPR and hatching success and the structure of protein profiles (i.e., number and intensity of electrophoretic bands of copepods (adults and eggs incubated during 96 h with the two food conditions. The structure of protein profiles included molecular sizes that were calculated from the relative mobility of protein standards against the logarithm of their molecular sizes. After assessing the experimental conditions, feeding decreased over time for those females fed with T. rotula, while reproduction was higher in females fed with P. minimum. Electrophoretic profiles resulted similar mostly at a banding region of 100 to 89-kDa, while they showed partial differences around the region of 56-kDa band, especially in those females fed and eggs produced with T. rotula. Due to reproductive volume was impacted while larvae viability, a physiological processes with specific and high nutritional requirements, was independent on food type; post-ingestive processes, such as expression of stress-related proteins deviating resources to metabolic processes others than reproduction, are discussed under framework of nutritional-toxic mechanisms mediating copepod-diatoms relationships in productive upwelling areas.

  17. Protein profile analysis of Malaysian snake venoms by two-dimensional gel electrophoresis

    Directory of Open Access Journals (Sweden)

    J Vejayan

    2010-01-01

    Full Text Available Snake venoms comprise a highly complex mixture of proteins, which requires for their characterization the use of versatile two-dimensional electrophoresis techniques. In the present study, venoms obtained from eight snakes (Ophiophagus hannah, Naja kaouthia, Naja sumatrana, Bungarus fasciatus, Trimeresurus sumatranus, Tropidolaemus wagleri, Enhydrina schistosa and Calloselasma rhodostoma commonly found in Malaysia were separated based on two independent properties, isoelectric point (pI and molecular weight (MW. Many differences in snake venoms at the inter-family, inter-subfamily, inter-genus and inter-species levels were revealed. Notably, proteins from individuals of the Viperidae family - Trimeresurus sumatranus, Tropidolaemus wagleri and Calloselasma rhodostoma - were found to be numerous and scattered by the two-dimensional gel electrophoresis (2DE specifically in regions between 37 and 100 kDa compared to the Elapidae venom proteins. The latter were clustered at the basic and lower molecular mass region (less than 20 kDa. Trains of spots were commonly observed, indicating that these proteins may be derived from post-translational modifications. Ophiophagus hannah (Elapidae revealed a great amount of protein spots in the higher molecular mass range when compared to Enhydrina schistosa, Naja kaouthia, Naja sumatrana and Bungarus fasciatus. Overall 2DE showed large differences in the venom profile of each species, which might be employed as an ancillary tool to the identification of venomous snake species.

  18. Electrophoretic pattern of blood serum proteins of some of the vertebrates of Pakistan

    International Nuclear Information System (INIS)

    Shakoori, Abdul Rauf; Zaheer, Saleem Akhtar; Ahmad, Muhammad Salih.

    1976-01-01

    The electrophoretic pattern of blood serum proteins of some of the common fishes e.g. Catla catla, Cirrhina mrigala, Channa punctatus, Channa marulius, Wallago attu, Heterop-neustes fossilis; amphibia e.g., Rana tigrina, Rana cyanophlyctis, Bufo melanostictus; reptiles e.g. Varanus bengalensis, Uromastix hardwickii; birds e.g. Columba livia, Gallus domesticus, Passer domestica, Anas platyrhynchos; and mammals e.g. Homo sapiens, Mus musculus, Lepus cuniculus have been described. The mobility of proteins of blood sera has been studied over cellulose acetate paper and then a comparative pattern analysed

  19. Measuring protein dynamics with ultrafast two-dimensional infrared spectroscopy

    International Nuclear Information System (INIS)

    Adamczyk, Katrin; Candelaresi, Marco; Hunt, Neil T; Robb, Kirsty; Hoskisson, Paul A; Tucker, Nicholas P; Gumiero, Andrea; Walsh, Martin A; Parker, Anthony W

    2012-01-01

    Recent advances in the methodology and application of ultrafast two-dimensional infrared (2D-IR) spectroscopy to biomolecular systems are reviewed. A description of the 2D-IR technique and the molecular contributions to the observed spectra are presented followed by a discussion of recent literature relating to the use of 2D-IR and associated approaches for measuring protein dynamics. In particular, these include the use of diatomic ligand groups for measuring haem protein dynamics, isotopic labelling strategies and the use of vibrational probe groups. The final section reports on the current state of the art regarding the use of 2D-IR methods to provide insights into biological reaction mechanisms. (topical review)

  20. NMRKIN: Simulating line shapes from two-dimensional spectra of proteins upon ligand binding

    International Nuclear Information System (INIS)

    Guenther, Ulrich L.; Schaffhausen, Brian

    2002-01-01

    The analysis of the shape of signals in NMR spectra is a powerful tool to study exchange and reaction kinetics. Line shapes in two-dimensional spectra of proteins recorded for titrations with ligands provide information about binding rates observed at individual residues. Here we describe a fast method to simulate a series of line shapes derived from two-dimensional spectra of a protein during a ligand titration. This procedure, which takes the mutual effects of two dimensions into account, has been implemented in MATLAB as an add-on to NMRLab (Guenther et al., 2000). In addition, more complex kinetic models, including sequential and parallel reactions, were simulated to demonstrate common features of more complex line shapes which could be encountered in protein-ligand interactions. As an example of this method, we describe its application to line shapes obtained for a titration of the p85 N-SH2 domain of PI3-kinase with a peptide derived from polyomavirus middle T antigen (MT)

  1. [Analysis of total proteins in the seed of almond (Prunus dulcis) by two-dimensional electrophoresis].

    Science.gov (United States)

    Li, Dong-dong; He, Shao-heng

    2004-07-01

    To analyse the total proteins in the seeds of almond (Prunus dulcis), one of the popular ingestent allergens in China, by two-dimensional electrophoresis. The total proteins of the seeds were extracted by trichloracetic acid (TCA) method, and then separated by isoelectric focusing as first dimension and SDS-PAGE as the second dimension. The spots of proteins were visualized by staining with Coomassie Brilliant Blue R-250. After analysis with software (ImageMaster 2D), 188 different proteins were detected. The isoelectric points (pI) for approximately 28% of total proteins were between 4.5-5.5, and the relative molecular mass (M(r)) of approximately 62% total proteins were between (20-25)x10(3). This was the first high-resolution, two-dimensional protein map of the seed of almond (Prunus dulcis) in China. Our finding has laid a solid foundation for further identification, characterization, gene cloning and standardization of allergenic proteins in the seed of almond (Prunus dulcis).

  2. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    ; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

  3. Introduction to the conformational investigation of peptides and proteins by using two-dimensional proton NMR experiments

    International Nuclear Information System (INIS)

    Neumann, J.M.; Macquaire, F.

    1991-01-01

    This report presents the elementary bases for an initiation to the conformational study of peptides and proteins by using two-dimensional proton NMR experiments. First, some general features of protein structures are summarized. A second chapter is devoted to the basic NMR experiments and to the spectral parameters which provide a structural information. This description is illustrated by NMR spectra of peptides. The third chapter concerns the most standard two-dimensional proton NMR experiments and their use for a conformational study of peptides and proteins. Lastly, an example of NMR structural investigation of a peptide is reported [fr

  4. Mass spectrometric analysis of electrophoretically separated allergens and proteases in grass pollen diffusates

    Directory of Open Access Journals (Sweden)

    Geczy Carolyn L

    2003-09-01

    Full Text Available Abstract Background Pollens are important triggers for allergic asthma and seasonal rhinitis, and proteases released by major allergenic pollens can injure airway epithelial cells in vitro. Disruption of mucosal epithelial integrity by proteases released by inhaled pollens could promote allergic sensitisation. Methods Pollen diffusates from Kentucky blue grass (Poa pratensis, rye grass (Lolium perenne and Bermuda grass (Cynodon dactylon were assessed for peptidase activity using a fluorogenic substrate, as well as by gelatin zymography. Following one- or two-dimensional gel electrophoresis, Coomassie-stained individual bands/spots were excised, subjected to tryptic digestion and analysed by mass spectrometry, either MALDI reflectron TOF or microcapillary liquid chromatography MS-MS. Database searches were used to identify allergens and other plant proteins in pollen diffusates. Results All pollen diffusates tested exhibited peptidase activity. Gelatin zymography revealed high Mr proteolytic activity at ~ 95,000 in all diffusates and additional proteolytic bands in rye and Bermuda grass diffusates, which appeared to be serine proteases on the basis of inhibition studies. A proteolytic band at Mr ~ 35,000 in Bermuda grass diffusate, which corresponded to an intense band detected by Western blotting using a monoclonal antibody to the timothy grass (Phleum pratense group 1 allergen Phl p 1, was identified by mass spectrometric analysis as the group 1 allergen Cyn d 1. Two-dimensional analysis similarly demonstrated proteolytic activity corresponding to protein spots identified as Cyn d 1. Conclusion One- and two-dimensional electrophoretic separation, combined with analysis by mass spectrometry, is useful for rapid determination of the identities of pollen proteins. A component of the proteolytic activity in Bermuda grass diffusate is likely to be related to the allergen Cyn d 1.

  5. Two-dimensional analysis of metabolically and cell surface radiolabeled proteins of some human lymphoid and myeloid leukemia cell lines. II. Glycosylated and phosphorylated proteins

    Energy Technology Data Exchange (ETDEWEB)

    Chorvath, B; Duraj, J; Sedlak, J; Pleskova, I

    1986-01-01

    Cell surface glycoproteins, radiolabelled by the sodium metaperiodate/tritiated borohydride technique, and cell phosphoproteins, metabolically radiolabelled with /sup 32/P-orthophosphate were analyzed by two-dimensional electrophoretic analysis in some myeloid and lymphoid leukemia cell lines. Some markedly expressed major glycoproteins were predominant in some of the cell lines (such as 95k and 100k glycoproteins with marked charge heterogeneity in non-T, non-B acute lymphoblastic leukemia cell lines NALM 6 and NALM 16), but markedly quantitatively reduced in other examined cell lines, such as lymphoblastoid cell line UHKT 34/2. /sup 32/P-orthophosphate radiolabelled phosphoprotein two-dimensional patterns of the examined lymphoid leukemia cell lines were essentially similar, with some minor differences, in examined lymphoid and myeloid leukemia cell lines, such as marked expression of a series of large phosphoproteins in the molecular weight range 80-100k in lymphoid cell lines and almost complete absence of these phosphoproteins on the examined myeloid leukemia cell lines. Another configuration of acidic phosphoproteins (30-35k) exhibited individual cell line variability and differences between both individual myeloid leukemia cell lines and between the lymphoid and myeloid cell lines examined. (author) 2 figs., 15 refs.

  6. Comparison of Yeast Cell Protein Solubilization Procedures for Two-dimensional Electrophoresis

    DEFF Research Database (Denmark)

    Harder, A; Wildgruber, R; Nawrocki, A

    1999-01-01

    Three different procedures for the solubilization of yeast (S. cerevisiae) cell proteins were compared on the basis of the obtained two-dimensional (2-D) polypeptide patterns. Major emphasis was laid on minimizing handling steps, protein modification or degradation, and quantitative loss of high...... with sodium dodecyl sulfate (SDS) buffer, consisting of 1% SDS and 100 mM tris(hydroxymethyl)aminomethane (Tris)-HCl, pH 7.0, followed by dilution with "standard" lysis buffer, and (iii) boiling the sample with SDS during cell lysis, followed by dilution with thiourea/urea lysis buffer (2 M thiourea/ 7 M urea...

  7. Efficient extraction of proteins from recalcitrant plant tissue for subsequent analysis by two-dimensional gel electrophoresis.

    Science.gov (United States)

    Parkhey, Suruchi; Chandrakar, Vibhuti; Naithani, S C; Keshavkant, S

    2015-10-01

    Protein extraction for two-dimensional electrophoresis from tissues of recalcitrant species is quite problematic and challenging due to the low protein content and high abundance of contaminants. Proteomics in Shorea robusta is scarcely conducted due to the lack of a suitable protein preparation procedure. To establish an effective protein extraction protocol suitable for two-dimensional electrophoresis in Shorea robusta, four procedures (borate buffer/trichloroacetic acid extraction, organic solvent/trichloroacetic acid precipitation, sucrose/Tris/phenol, and organic solvent/phenol/sodium dodecyl sulfate) were evaluated. Following these, proteins were isolated from mature leaves and were analyzed for proteomics, and also for potential contaminants, widely reported to hinder proteomics. The borate buffer/trichloroacetic acid extraction had the lowest protein yield and did not result in any banding even in one-dimensional electrophoresis. In contrast, organic solvent/phenol/sodium dodecyl sulfate extraction allowed the highest protein yield. Moreover, during proteomics, organic solvent/phenol/sodium dodecyl sulfate extracted protein resolved the maximum number (144) of spots. Further, when proteins were evaluated for contaminants, significant (77-95%) reductions in the nucleic acids, phenol, and sugars were discernible with refinement in extraction procedure. Accumulated data suggested that the organic solvent/phenol/sodium dodecyl sulfate extraction was the most effective protocol for protein isolation for proteomics of Shorea robusta and can be used for plants that have a similar set of contaminants. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Expression of Leaf Proteins in Two Cultivars of Bread Wheat under Cadmium and Mercury Stress Using Two-Dimensional Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    S. Y. Raeesi Sadati

    2016-02-01

    Full Text Available Wheat is an important source of human food. Cadmium and mercury bind to sulfhydryl groups of structural proteins and enzymes and cause inhibition in activity and decrease in protein production or interfere with the regulation of the enzymes. To study the effect of protein expression under different levels of cadmium and mercury, the experiment was conducted in a completely randomized design with three replications in Mohaghegh Ardabili University, Ardabil, Iran. Experimental factors consisted of two Gonbad and Tajan bread what cultivars, heavy metals in seven levels (four concentrations of mercuric chloride in 5, 10, 15 and 20 µM and cadmium chloride at two concentrations of 0.25 and 0.5 mM and sampling time after 8 and 16 hours of treatment. The Bradford method was used for quantitative analysis of proteins and 12% SDS-PAGE and two dimensional electrophorese techniques were hired for analysis of their expression. The results showed that under cadmium and mercury stresses, the total protein content increased compared to the control. Two-dimensional electrophoresis of proteins under cadmium stress showed differential expression of the protein spots on the plant leaves, than the control. In general, changes in the expression of proteins under the effect of cadmium stress were divided into two main categories: Spots 9, 10, 13, 14 and 16 belonged to proteins with reduced expression and the spots 1, 2, 8, 19 and 20 belonged to proteins with increased expression, in comparison to non-stressed control. These spots of up regulated proteins were directly related to the defense system against the heavy metal stress.

  9. Liquid phase separation of proteins based on electrophoretic effects in an electrospray setup during sample introduction into a gas-phase electrophoretic mobility molecular analyzer (CE–GEMMA/CE–ES–DMA)

    Science.gov (United States)

    Weiss, Victor U.; Kerul, Lukas; Kallinger, Peter; Szymanski, Wladyslaw W.; Marchetti-Deschmann, Martina; Allmaier, Günter

    2014-01-01

    Nanoparticle characterization is gaining importance in food technology, biotechnology, medicine, and pharmaceutical industry. An instrument to determine particle electrophoretic mobility (EM) diameters in the single-digit to double-digit nanometer range receiving increased attention is the gas-phase electrophoretic mobility molecular analyzer (GEMMA) separating electrophoretically single charged analytes in the gas-phase at ambient pressure. A fused-silica capillary is used for analyte transfer to the gas-phase by means of a nano electrospray (ES) unit. The potential of this capillary to separate analytes electrophoretically in the liquid phase due to different mobilities is, at measurement conditions recommended by the manufacturer, eliminated due to elevated pressure applied for sample introduction. Measurements are carried out upon constant feeding of analytes to the system. Under these conditions, aggregate formation is observed for samples including high amounts of non-volatile components or complex samples. This makes the EM determination of individual species sometimes difficult, if not impossible. With the current study we demonstrate that liquid phase electrophoretic separation of proteins (as exemplary analytes) occurs in the capillary (capillary zone electrophoresis, CE) of the nano ES unit of the GEMMA. This finding was consecutively applied for on-line desalting allowing EM diameter determination of analytes despite a high salt concentration within samples. The present study is to our knowledge the first report on the use of the GEMMA to determine EM diameters of analytes solubilized in the ES incompatible electrolyte solutions by the intended use of electrophoresis (in the liquid phase) during sample delivery. Results demonstrate the proof of concept of such an approach and additionally illustrate the high potential of a future on-line coupling of a capillary electrophoresis to a GEMMA instrument. PMID:25109866

  10. Comparison of ethanol-soluble proteins from different rye (Secale cereale) varieties by two-dimensional electrophoresis

    DEFF Research Database (Denmark)

    Radzikowski, Louise; Nesic, Ljiljana; Hansen, H.B.

    2002-01-01

    The major storage proteins from six rye varieties, grown under the same conditions in 1997 and 1998 in Ronhave, Denmark, were analyzed by two-dimensional (2-D) polyacrylamide gel electrophoresis. The proteins were extracted from ground rye kernels with 70% ethanol and separated by 2-D electrophor......The major storage proteins from six rye varieties, grown under the same conditions in 1997 and 1998 in Ronhave, Denmark, were analyzed by two-dimensional (2-D) polyacrylamide gel electrophoresis. The proteins were extracted from ground rye kernels with 70% ethanol and separated by 2-D...... electrophoresis. The gels were scanned, compared using ImageMaster(R) software and the data sets were analyzed by principal component analysis (PCA) using THE UNSCRAMBLER software. Afterwards MATLAB was used to make a cluster analysis of the varieties based on PCA. The analysis of the gels showed...... separately. When the results were combined from the two years five varieties could be differentiated. The results from the PCA confirmed the finding of the unique spots and cluster analysis was made in order to illustrate the results. The combination of the results from 2-D electrophoresis and other grain...

  11. The electrophoretic mobility shift assay (EMSA)

    OpenAIRE

    sprotocols

    2015-01-01

    The electrophoretic mobility shift assay (EMSA), also known as “gel shift assay”, is used to examine the binding parameters and relative affinities of protein and DNA interactions. We produced recombinant CCA1 protein and tested its binding affinity for the promoter fragments that contain CBS (AAAAATCT) or evening element (EE, AAAATATCT) (1) using a modified procedure adopted from published protocols (2,3).

  12. Characterization and identification of early proteins in Chlamydia trachomatis serovar L2 by two-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Lundemose, AG; Birkelund, Svend; Larsen, PM

    1990-01-01

    The synthesis of early proteins from Chlamydia trachomatis serovar L2 was analyzed by two-dimensional gel electrophoresis. By pulse-label experiments, the synthesis of seven proteins was observed at 2 to 8 h postinfection before the major outer membrane protein was detected at 8 to 10 h after...

  13. Serum Protein Electrophoretic Pattern in Neonatal Calves Treated with Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Simona Marc

    2018-05-01

    Full Text Available The objective of our study was to determine the effects of clinoptilolite supplemented in colostrum on the blood serum protein electrophoretic pattern of new-born calves. Methods: Romanian Black and White new-born calves involved in the study were divided into 3 groups: the control group (C that received colostrum without clinoptilolite, and experimental groups I (E1 and II (E2 that received colostrum supplemented with 0.5% and 2% clinoptilolite, respectively. The concentration of total protein and protein fractions (albumin, α1-globulin, α2-globulin, β-globulin and γ-globulin were analyzed by electrophoresis on cellulose acetate. Results: At hour 30 after birth, concentrations of γ-globulins, β-globulin and total protein in E1 group of calves were higher than in control group by 42.11% (p < 0.05, 28.48% (p > 0.05 and 18.52% (p > 0.05, respectively, and were higher, but not significantly, in group E2 compared to the control group. This was in accordance with a significant lower albumin/globulin ratio in groups E1 and E2 (29.35%, p < 0.05 and 35.87%, p < 0.05, respectively than in control group at 30 h postpartum, which indicates an obvious increase of the globulins fraction in experimental groups. The conclusion: Clinoptilolite was effective in improving passive transfer in new-born calves, but it was more effective if added in colostrum with a dose of 0.5% than with a dose of 2%.

  14. Development of two dimensional electrophoresis method using single chain DNA

    International Nuclear Information System (INIS)

    Ikeda, Junichi; Hidaka, So

    1998-01-01

    By combining a separation method due to molecular weight and a method to distinguish difference of mono-bases, it was aimed to develop a two dimensional single chain DNA labeled with Radioisotope (RI). From electrophoretic pattern difference of parent and variant strands, it was investigated to isolate the root module implantation control gene. At first, a Single Strand Conformation Polymorphism (SSCP) method using concentration gradient gel was investigated. As a result, it was formed that intervals between double chain and single chain DNAs expanded, but intervals of both single chain DNAs did not expand. On next, combination of non-modified acrylic amide electrophoresis method and Denaturing Gradient-Gel Electrophoresis (DGGE) method was examined. As a result, hybrid DNA developed by two dimensional electrophoresis arranged on two lines. But, among them a band of DNA modified by high concentration of urea could not be found. Therefore, in this fiscal year's experiments, no preferable result could be obtained. By the used method, it was thought to be impossible to detect the differences. (G.K.)

  15. Protein composition of wheat gluten polymer fractions determined by quantitative two-dimensional gel electrophoresis and tandem mass spectrometry

    Science.gov (United States)

    Flour proteins from the US bread wheat Butte 86 were extracted in 0.5% SDS using a two-step procedure with and without sonication and further separated by size exclusion chromatography into monomeric and polymeric fractions. Proteins in each fraction were analyzed by quantitative two-dimensional gel...

  16. Two-dimensional gel electrophoresis of selenized yeast and autoradiography of 75Se-containing proteins

    International Nuclear Information System (INIS)

    Chery, C.C.; Dumont, E.; Cornelis, R.; Moens, L.

    2001-01-01

    Two-dimensional high-resolution gel electrophoresis (2DE) has been applied to the fractionation of 75 Se-containing proteins in yeast, grown in 75 Se-containing medium, and autoradiography was used for detection of the 75 Se-containing proteins. Gel filtration and ultrafiltration were used to check whether the selenium side-chains were stable in the presence of the chemicals used for lysis and 2DE. The mass distribution of the selenium-containing proteins was estimated by use of gel filtration and the results were compared with the distribution obtained by 2DE. A 2DE map of selenium-containing proteins in yeast is presented, and compared with a total protein map of yeast. (orig.)

  17. Characterization of royal jelly proteins in both Africanized and European honeybees (Apis mellifera) by two-dimensional gel electrophoresis.

    Science.gov (United States)

    Sano, Osamu; Kunikata, Toshio; Kohno, Keizo; Iwaki, Kanso; Ikeda, Masao; Kurimoto, Masashi

    2004-01-14

    In this study, the proteins contained in royal jelly (RJ) produced by Africanized honeybees and European honeybees (Apis mellifera) haven been analyzed in detail and compared using two-dimensional gel electrophoresis, and the N-terminal amino acid sequence of each spot has been determined. Most spots were assigned to major royal jelly proteins (MRJPs). Remarkable differences were found in the heterogeneity of the MRJPs, in particular MRJP3, in terms of molecular weights and isoelectric points between the two species of RJ. Furthermore, during the determination of the N-terminal amino acid sequence of each spot, for the first time, MRJP4 protein has been identified, the existence of which had been only implied by cloning of its cDNA sequence. The presence of heterogeneous bands of glucose oxidase was also identified. Thus, the results suggest that two-dimensional gel electrophoresis provides a suitable method for the qualitative analysis of the proteins contained in RJ derived from different honeybee species.

  18. Sialic acid accelerates the electrophoretic velocity of injured dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Chen-xu Li

    2015-01-01

    Full Text Available Peripheral nerve injury has been shown to result in ectopic spontaneous discharges on soma and injured sites of sensory neurons, thereby inducing neuropathic pain. With the increase of membrane proteins on soma and injured site neurons, the negatively charged sialic acids bind to the external domains of membrane proteins, resulting in an increase of this charge. We therefore speculate that the electrophoretic velocity of injured neurons may be faster than non-injured neurons. The present study established rat models of neuropathic pain via chronic constriction injury. Results of the cell electrophoresis test revealed that the electrophoretic velocity of injured neuronal cells was faster than that of non-injured (control cells. We then treated cells with divalent cations of Ca 2+ and organic compounds with positive charges, polylysine to counteract the negatively charged sialic acids, or neuraminidase to specifically remove sialic acids from the membrane surface of injured neurons. All three treatments significantly reduced the electrophoretic velocity of injured neuronal cells. These findings suggest that enhanced sialic acids on injured neurons may accelerate the electrophoretic velocity of injured neurons.

  19. Facilitating the Hyphenation of CIEF and MALDI-MS for Two-Dimensional Separation of Proteins

    Science.gov (United States)

    Cheng, Chang; Lu, Joann J.; Wang, Xiayan; Roberts, Jonathan; Liu, Shaorong

    2011-01-01

    Both CIEF and MALDI-MS are frequently used in protein analysis, but hyphenation of the two is not investigated proportionally. One of the major reasons is that the additives (such as carrier ampholytes and detergent) in CIEF severely suppress the MALDI-MS signal, which hampers the hyphenation of the two. In this paper, we develop a simple means to alleviate the above signal-suppressing effect. We first deposit 1 µL of water onto a MALDI-MS target, deliver a fraction of CIEF-separated protein (~0.1 µL) to the water droplet, evaporate the solvent, add 0.5 µL of MALDI matrix to the sample spot, dry the matrix, and move the target plate to a MALDI-TOF-MS for mass spectrum measurement. We optimize the droplet volume and the laser-ablation region. Under the optimized conditions, we improve the signal to noise ratio by 2–10 fold. We also apply this method for two-dimensional separations of standard proteins and Apolipoprotein A-I, a membrane protein expressed in E. Coli cells. PMID:20603827

  20. Mapping of 34 minisatellite loci resolved by two-dimensional DNA typing

    DEFF Research Database (Denmark)

    Børglum, Anders; Nyegaard, Mette; Kvistgaard, AB

    1997-01-01

    Two-dimensional (2-D) DNA typing is based on electrophoretic separation of genomic DNA fragments in two dimensions according to independent criteria (size and base-pair sequence), followed by hybridization analysis using multilocus probes. The technique allows simultaneous visualization of several...... could be deduced, showing no evidence of clustering. In the analysis of spot patterns, use was made of a computerized image analysis system specifically designed for 2-D DNA typing. Since experimental variations between different separation patterns were automatically corrected for with this program......, rapid and reliable scorings could be obtained. The results presented demonstrate the availability of reliable genetic information throughout the 2-D separation pattern. Adding the use of semiautomated computerized pattern analysis, this study further substantiates the applicability of 2-D DNA typing...

  1. Electrophoretic mobility shift assay reveals a novel recognition sequence for Setaria italica NAC protein.

    Science.gov (United States)

    Puranik, Swati; Kumar, Karunesh; Srivastava, Prem S; Prasad, Manoj

    2011-10-01

    The NAC (NAM/ATAF1,2/CUC2) proteins are among the largest family of plant transcription factors. Its members have been associated with diverse plant processes and intricately regulate the expression of several genes. Inspite of this immense progress, knowledge of their DNA-binding properties are still limited. In our recent publication,1 we reported isolation of a membrane-associated NAC domain protein from Setaria italica (SiNAC). Transactivation analysis revealed that it was a functionally active transcription factor as it could stimulate expression of reporter genes in vivo. Truncations of the transmembrane region of the protein lead to its nuclear localization. Here we describe expression and purification of SiNAC DNA-binding domain. We further report identification of a novel DNA-binding site, [C/G][A/T][T/A][G/C]TC[C/G][A/T][C/G][G/C] for SiNAC by electrophoretic mobility shift assay. The SiNAC-GST protein could bind to the NAC recognition sequence in vitro as well as to sequences where some bases had been reshuffled. The results presented here contribute to our understanding of the DNA-binding specificity of SiNAC protein.

  2. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Gordaliza, Estefanía, E-mail: emorenog@ucm.es [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain); Stigter, Edwin C.A. [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Molecular Cancer Research, Universitair Medisch Centrum Utrecht, Wilhelmina Kinder Ziekenhuis, Lundlaan 6, 3584, EA Utrecht (Netherlands); Lindenburg, Petrus W.; Hankemeier, Thomas [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands)

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10{sup −9} m{sup 2} V{sup −1} s{sup −1}) when compared with unmodified fused silica (5.9 ± 0.1 10{sup −8} m{sup 2} V{sup −1} s{sup −1}). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1–1.8% coefficient-of-variation (CV) within a day) and 2–3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. - Highlights: • New coating using recrystallized surface-layer proteins on

  3. Reagent-Free Electrophoretic Synthesis of Few-Atom-Thick Metal Oxide Nanosheets

    DEFF Research Database (Denmark)

    Hou, Chengyi; Zhang, Minwei; Zhang, Lili

    2017-01-01

    Engineering traditional materials into the new form of atomic and free-standing two-dimensional structures is of both fundamental interest and practical significance, but it is in general facing challenges especially for metal oxide semiconductors. We herein report an ultragreen method for the cost......-effective and fast preparation of atomic metal oxide nanosheets that can be further transformed into nanofilms. The method combines top-down building block synthesis and bottom-up electrophoretic assembly in water under ambient conditions, using only bulk metal and Milli-Q water without involving any additional...

  4. Two-dimensional liquid chromatography consisting of twelve second-dimension columns for comprehensive analysis of intact proteins.

    Science.gov (United States)

    Ren, Jiangtao; Beckner, Matthew A; Lynch, Kyle B; Chen, Huang; Zhu, Zaifang; Yang, Yu; Chen, Apeng; Qiao, Zhenzhen; Liu, Shaorong; Lu, Joann J

    2018-05-15

    A comprehensive two-dimensional liquid chromatography (LCxLC) system consisting of twelve columns in the second dimension was developed for comprehensive analysis of intact proteins in complex biological samples. The system consisted of an ion-exchange column in the first dimension and the twelve reverse-phase columns in the second dimension; all thirteen columns were monolithic and prepared inside 250 µm i.d. capillaries. These columns were assembled together through the use of three valves and an innovative configuration. The effluent from the first dimension was continuously fractionated and sequentially transferred into the twelve second-dimension columns, while the second-dimension separations were carried out in a series of batches (six columns per batch). This LCxLC system was tested first using standard proteins followed by real-world samples from E. coli. Baseline separation was observed for eleven standard proteins and hundreds of peaks were observed for the real-world sample analysis. Two-dimensional liquid chromatography, often considered as an effective tool for mapping proteins, is seen as laborious and time-consuming when configured offline. Our online LCxLC system with increased second-dimension columns promises to provide a solution to overcome these hindrances. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Evidence of the protein content of bovine and human dental pulps by the action of endodontic irrigation solutions through electrophoretic patterns

    Directory of Open Access Journals (Sweden)

    María E López

    2013-01-01

    Full Text Available Background: Sodium dodecyl sulfate polyacrylamide gel electrophoresis let to show the protein content of different tissues. Dental pulp contains connective tissue which is removed during the endodontic treatment. Many studies consider bovine rather than human pulp tissue because of its size. Aim: To evidence the protein content of bovine and human dental pulps and the action of endodontic irrigation solutions through electrophoretic patterns. Materials and Methods: Extracts of human and bovine dental pulps were prepared. Sodium hypochlorite, calcium hydroxide, chlorhexidine and ethylenediamine tetraacetic acid were used as irrigating solutions. Results: Bovine and human pulps have a small difference in two bands of proteins present between 74 kDa and 80 kDa. The denaturizing capacity of sodium hypochlorite and the washing action of calcium hydroxide and chlorhexidine were evidenced. Ethylenediamine tetraacetic acid solution was shown to contain proteins continuously during the endodontic root canal washing. Conclusions: Differences in pulp tissues and the action of irrigating solutions on their protein content would help on the understanding of the biological process of the endodontic treatment.

  6. Mapping and identification of interferon gamma-regulated HeLa cell proteins separated by immobilized pH gradient two-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Shaw, A.; Larsen, M.; Roepstorff, P.

    1999-01-01

    magnitude of IFN-gamma responsive genes has been reported previously. Our goal is to identify and map IFN-gamma-regulated HeLa cell proteins to the two-dimensional polyacrylamide gel electrophoresis with the immobilized pH gradient (IPG) two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) system...

  7. New approach based on fuzzy logic and principal component analysis for the classification of two-dimensional maps in health and disease. Application to lymphomas.

    Science.gov (United States)

    Marengo, Emilio; Robotti, Elisa; Righetti, Pier Giorgio; Antonucci, Francesca

    2003-07-04

    Two-dimensional (2D) electrophoresis is the most wide spread technique for the separation of proteins in biological systems. This technique produces 2D maps of high complexity, which creates difficulties in the comparison of different samples. The method proposed in this paper for the comparison of different 2D maps can be summarised in four steps: (a) digitalisation of the image; (b) fuzzyfication of the digitalised map in order to consider the variability of the two-dimensional electrophoretic separation; (c) decoding by principal component analysis of the previously obtained fuzzy maps, in order to reduce the system dimensionality; (d) classification analysis (linear discriminant analysis), in order to separate the samples contained in the dataset according to the classes present in said dataset. This method was applied to a dataset constituted by eight samples: four belonging to healthy human lymph-nodes and four deriving from non-Hodgkin lymphomas. The amount of fuzzyfication of the original map is governed by the sigma parameter. The larger the value, the more fuzzy theresulting transformed map. The effect of the fuzzyfication parameter was investigated, the optimal results being obtained for sigma = 1.75 and 2.25. Principal component analysis and linear discriminant analysis allowed the separation of the two classes of samples without any misclassification.

  8. Velocity and Dispersion for a Two-Dimensional Random Walk

    International Nuclear Information System (INIS)

    Li Jinghui

    2009-01-01

    In the paper, we consider the transport of a two-dimensional random walk. The velocity and the dispersion of this two-dimensional random walk are derived. It mainly show that: (i) by controlling the values of the transition rates, the direction of the random walk can be reversed; (ii) for some suitably selected transition rates, our two-dimensional random walk can be efficient in comparison with the one-dimensional random walk. Our work is motivated in part by the challenge to explain the unidirectional transport of motor proteins. When the motor proteins move at the turn points of their tracks (i.e., the cytoskeleton filaments and the DNA molecular tubes), some of our results in this paper can be used to deal with the problem. (general)

  9. Electrophoretic analysis of proteins from Mycoplasma capricolum and related serotypes using extracts from intact cells and from minicells containing cloned mycoplasma DNA

    DEFF Research Database (Denmark)

    Andersen, H; Christiansen, Gunna; Christiansen, C

    1984-01-01

    The acidic proteins of six different mycoplasma serotypes causing bovine or caprine pleuropneumonia were compared by two-dimensional gel electrophoresis of extracts of 35S-labelled cells. The organisms investigated were Mycoplasma mycoides subsp. mycoides (PG1), M. mycoides subsp. mycoides (Y......, whereas the two M. mycoides subspecies appeared to be quite distant from M. capricolum and F38. The representative strain of the bovine serogroup 7 of Leach was equally distant from F38, M. capricolum and the three strains of M. mycoides. Strikingly, all six mycoplasma strains apparently shared six...... proteins in the two-dimensional gels. In Escherichia coli minicells, DNA from strain PG50 cloned in the vector pBR325 gave rise to incorporation of radioactive label into proteins which were identified as mycoplasma proteins by two-dimensional electrophoresis and immunoprecipitation....

  10. Protein content and electrophoretic profile of fat body and ovary extracts from workers of Melipona quadrifasciata anthidioides (Hymenoptera, Meliponini

    Directory of Open Access Journals (Sweden)

    Vagner T. Paes de Oliveira

    Full Text Available Workers of Melipona quadrifasciata anthidioides (Lepeletier, 1836 develop their ovaries and lay eggs, therefore the production of vitellogenin is expected. In electrophoretic profiles only fat body extracts from nurse workers and ovary extracts from newly-emerged workers show protein with molecular mass similar to vitellogenin. However, an increase in the protein content was detected in forager fat body. This increase was attributed to storage of vitellogenin or other proteins in the previous phase and not discharged into the hemolymph or to an effect of the increased titre of juvenile hormone in this phase of worker life over the fat body functioning.

  11. The master two-dimensional gel database of human AMA cell proteins: towards linking protein and genome sequence and mapping information (update 1991)

    DEFF Research Database (Denmark)

    Celis, J E; Leffers, H; Rasmussen, H H

    1991-01-01

    autoantigens" and "cDNAs". For convenience we have included an alphabetical list of all known proteins recorded in this database. In the long run, the main goal of this database is to link protein and DNA sequencing and mapping information (Human Genome Program) and to provide an integrated picture......The master two-dimensional gel database of human AMA cells currently lists 3801 cellular and secreted proteins, of which 371 cellular polypeptides (306 IEF; 65 NEPHGE) were added to the master images during the last 10 months. These include: (i) very basic and acidic proteins that do not focus...

  12. Initial proteome analysis of caffeine-induced proteins in Aspergillus tamarii using two-dimensional fluorescence difference gel electrophoresis.

    Science.gov (United States)

    Gutiérrez-Sánchez, Gerardo; Atwood, James; Kolli, V S Kumar; Roussos, Sévastianos; Augur, Christopher

    2012-04-01

    Caffeine is toxic to most microorganisms. However, some filamentous fungi, such as Aspergillus tamarii, are able to metabolize this alkaloid when fed caffeine as the sole nitrogen source. The aim of the present work was to identify intracellular A. tamarii proteins, regulated by caffeine, using fluorescence difference two-dimensional gel electrophoresis. Specific proteins from two culture media of A. tamarii grown either on ammonium sulfate or caffeine as the sole nitrogen source were analysed by mass spectrometry. Thirteen out of a total of 85 differentially expressed spots were identified after database search. Identified up-regulated proteins include phosphoglycerate kinase, malate dehydrogenase, dyp-type peroxidase family protein, heat shock protein, Cu, Zn superoxidase dismutase and xanthine dehydrogenase. Some of the proteins identified in this study are involved in the caffeine degradation pathway as well as in stress response, suggesting that stress proteins could be involved in caffeine metabolism in filamentous fungi.

  13. Electrophoretic mobility shift in native gels indicates calcium-dependent structural changes of neuronal calcium sensor proteins.

    Science.gov (United States)

    Viviano, Jeffrey; Krishnan, Anuradha; Wu, Hao; Venkataraman, Venkat

    2016-02-01

    In proteins of the neuronal calcium sensor (NCS) family, changes in structure as well as function are brought about by the binding of calcium. In this article, we demonstrate that these structural changes, solely due to calcium binding, can be assessed through electrophoresis in native gels. The results demonstrate that the NCS proteins undergo ligand-dependent conformational changes that are detectable in native gels as a gradual decrease in mobility with increasing calcium but not other tested divalent cations such as magnesium, strontium, and barium. Surprisingly, such a gradual change over the entire tested range is exhibited only by the NCS proteins but not by other tested calcium-binding proteins such as calmodulin and S100B, indicating that the change in mobility may be linked to a unique NCS family feature--the calcium-myristoyl switch. Even within the NCS family, the changes in mobility are characteristic of the protein, indicating that the technique is sensitive to the individual features of the protein. Thus, electrophoretic mobility on native gels provides a simple and elegant method to investigate calcium (small ligand)-induced structural changes at least in the superfamily of NCS proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Cu2+-assisted two dimensional charge-mass double focusing gel electrophoresis and mass spectrometric analysis of histone variants.

    Science.gov (United States)

    Zhang, Wenyang; Tang, Xuemei; Ding, Mengjie; Zhong, Hongying

    2014-12-10

    Abundant isoforms and dynamic posttranslational modifications cause the separation and identification of histone variants to be experimentally challenging. To meet this need, we employ two-dimensional electrophoretic gel separation followed by mass spectrometric detection which takes advantage of the chelation of Cu(2+) with amino acid residues exposed on the surfaces of the histone proteins. Acid-extracted rat liver histones were first mixed with CuSO4 solution and then separated in one dimension with triton-acid-urea (TAU) gel electrophoresis and in a second dimension using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The separations result from both the changes in charge and mass upon Cu(2+) chelation. Identities of each separated gel bands were obtained by using matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS). It was found that the migration of H3 histone isoforms of rat liver is markedly affected by the use of Cu(2+) ions. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Electrophoretic variants of blood proteins in japanese, 5

    International Nuclear Information System (INIS)

    Fujita, Mikio; Satoh, Chiyoko; Asakawa, Jun-ichi; Nagahata, Yuko; Tanaka, Yoshiko; Hazama, Ryuji; Goriki, Kazuaki.

    1985-08-01

    The plasma ceruloplasmin (CP) of 22,367 children of atomic bomb survivors in Hiroshima and Nagasaki was examined for variants by electrophoresis. The sample was composed of 14,964 unrelated children and 7,403 siblings of the unrelated persons. A total of seven types of electrophoretic variants were detected; four migrating anodally and three cathodally to the normal B band. We have reported two of these variants, CP A sub(NG1) and CP C sub(NG1), previously but the other five, CP A sub(NG2), CP A sub(HR1), CP A sub(HR2), CP C sub(HR1), and CP C sub(HR2), are newly identified. The allelic frequency of CP*CNG1 was 0.00916, so that the variant is considered to be a polymorphic allele. Homozygosity for the CP*CNG1 allele was detected in five individuals. This is the first report of a homozygous phenotype for a CP variant in a Japanese population. Family study of the new five variants all demonstrated patterns of codominant inheritance. (author)

  16. Electrophoretic and immunological properties of folate-binding protein isolated from bovine milk

    International Nuclear Information System (INIS)

    Iwai, Kazuo; Tani, Masako; Fushiki, Tohru

    1983-01-01

    Changes of the folate-binding protein (FBP) concentration in bovine milk after parturition were investigated. The FBP was highly purified from mature milk by affinity chromatography. The purified FBP showed a single protein band in polyacrylamide gel electrophoresis and was immunologically homogenous in double immunodiffusion. However, in two-dimensional gel electrophoresis, the FBP was separated into several spots in isoelectric focusing in the first dimension, and each spot also showed two molecular weights in SDS-gel electrophoresis in the second dimension. But these FBP molecules were immunologically identical with each other. The neuraminidase treatment obviously diminished the number of isoelectric points of the FBP. Thus, the variety of FBP molecules was at least partially due to the variability of the sialic acid content in the carbohydrate moieties. Moreover, the milk FBP showed species-specificity among mammals immunologically as well as physicochemically. (author)

  17. Stabilization of green bodies via sacrificial gelling agent during electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Kuntz, Joshua D.; Rose, Klint A.

    2016-03-22

    In one embodiment, a method for electrophoretic deposition of a three-dimensionally patterned green body includes suspending a first material in a gelling agent above a patterned electrode of an electrophoretic deposition (EPD) chamber, and gelling the suspension while applying a first electric field to the suspension to cause desired patterning of the first material in a resulting gelation. In another embodiment, a ceramic, metal, or cermet includes a plurality of layers, wherein each layer includes a gradient in composition, microstructure, and/or density in an x-y plane oriented parallel to a plane of deposition of the plurality of layers along a predetermined distance in a z-direction perpendicular to the plane of deposition.

  18. Relationship between recombinant protein expression and host metabolome as determined by two-dimensional NMR spectroscopy.

    Directory of Open Access Journals (Sweden)

    Young Kee Chae

    Full Text Available Escherichia coli has been the most widely used host to produce large amounts of heterologous proteins. However, given an input plasmid DNA, E. coli may produce soluble protein, produce only inclusion bodies, or yield little or no protein at all. Many efforts have been made to surmount these problems, but most of them have involved time-consuming and labor-intensive trial-and-error. We hypothesized that different metabolomic fingerprints might be associated with different protein production outcomes. If so, then it might be possible to change the expression pattern by manipulating the metabolite environment. As a first step in testing this hypothesis, we probed a subset of the intracellular metabolites by partially labeling it with 13C-glucose. We tested 71 genes and identified 17 metabolites by employing the two-dimensional NMR spectroscopy. The statistical analysis showed that there existed the metabolite compositions favoring protein production. We hope that this work would help devise a systematic and predictive approach to the recombinant protein production.

  19. Nano-structured yttria-stabilized zirconia coating by electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maleki-Ghaleh, H., E-mail: H_Maleki@sut.ac.ir [Faculty of Materials Engineering, Sahand University of Technology, Tabriz (Iran, Islamic Republic of); Rekabeslami, M. [Faculty of Mechanical Engineering, Materials Science and Engineering Division, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shakeri, M.S. [Materials and Energy Research Center, Karaj (Iran, Islamic Republic of); Siadati, M.H. [Faculty of Mechanical Engineering, Materials Science and Engineering Division, K. N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Javidi, M. [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Talebian, S.H. [Faculty of Petroleum Engineering, Universiti Technologi Petronas, Perak (Malaysia); Aghajani, H. [Department of Materials Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2013-09-01

    The most important role of thermal barrier coatings is to reduce the temperature of the substrate in high temperature applications. Nanoparticle zirconia might be a suitable choice for improving the efficiency of thermal barrier coatings. Nanostructured coatings have lower thermal conduction, higher thermal expansion and lower dimensional variations at higher temperatures in comparison with the microstructured coatings. Electrophoretic deposition has been preferred for thermal barrier coatings due to its simplicity, controllability and low cost. In the present study, three different suspensions of ZrO{sub 2}–8 wt%Y{sub 2}O{sub 3} (40 nm) made with ethanol, acetone and acetyl acetone were used. Electrophoretic deposition was conducted at a fixed voltage of 60 V for 120 s on aluminized Inconel 738-LC, and then heat treated at 1100{sup o}C for 4 h in air atmosphere. The coating morphology and elemental distribution were studied using scanning electron microscopy. It was observed that suspension media have an important effect on the quality of the final product. Acetyl acetone showed better dispersion of particles than the other two media. Consequently, deposition from acetyl acetone resulted in uniform and crack-free layers while those from ethanol and acetone were completely non-uniform due to agglomeration and low viscosity, respectively.

  20. Avoiding acidic region streaking in two-dimensional gel electrophoresis: case study with two bacterial whole cell protein extracts.

    Science.gov (United States)

    Roy, Arnab; Varshney, Umesh; Pal, Debnath

    2014-09-01

    Acidic region streaking (ARS) is one of the lacunae in two-dimensional gel electrophoresis (2DE) of bacterial proteome. This streaking is primarily caused by nucleic acid (NuA) contamination and poses major problem in the downstream processes like image analysis and protein identification. Although cleanup and nuclease digestion are practiced as remedial options, these strategies may incur loss in protein recovery and perform incomplete removal of NuA. As a result, ARS has remained a common observation across publications, including the recent ones. In this work, we demonstrate how ultrasound wave can be used to shear NuA in plain ice-cooled water, facilitating the elimination of ARS in the 2DE gels without the need for any additional sample cleanup tasks. In combination with a suitable buffer recipe, IEF program and frequent paper-wick changing approach, we are able to reproducibly demonstrate the production of clean 2DE gels with improved protein recovery and negligible or no ARS. We illustrate our procedure using whole cell protein extracts from two diverse organisms, Escherichia coli and Mycobacterium smegmatis. Our designed protocols are straightforward and expected to provide good 2DE gels without ARS, with comparable times and significantly lower cost.

  1. µE: Electrophoretic mobility

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. µE: Electrophoretic mobility. µE: Electrophoretic mobility. E: Intensity of electric field. H: Total height. h: Distance from the top surface of bottom chamber (slug height). N: Cell concentration × Volume of the chamber.

  2. Changes in the serum protein electrophoretic pattern in lambs during the first month of life

    Directory of Open Access Journals (Sweden)

    Oskar Nagy

    2014-01-01

    Full Text Available Studies of the changes in serum protein pattern in the neonatal period in animals are still limited. Therefore, the objective of this study was to evaluate the changes in the concentrations of serum protein fractions in 7 clinically healthy merino lambs (4 males, 3 females during their first month of life. The first blood sampling was performed before the colostrum intake and then at 1, 2, 7, 14 and 30 days of age. Blood serum was analysed for total serum protein concentrations and for the relative and absolute values of serum protein fractions - albumin, alpha1- (α1, alpha2- (α2, beta- (β, and gamma- (γ globulins. The results showed a significant effect of age on the serum total protein concentrations and for all the protein fractions. The concentrations of total proteins and γ-globulins increased significantly 1 day after the colostrum intake (P P 1-globulins significantly decreased during the first month of life (P 2- and β-globulins increased significantly from birth till the end of the monitored period (P < 0.001. Our results suggest that the serum protein electrophoretic pattern in growing lambs is significantly influenced by the age of the evaluated animal, and this should be taken into consideration when interpreting the serum protein profile. Our findings extend existing knowledge about significant changes in the protein profile associated with the physiological adaptation process in the neonatal period in young animals.

  3. Studies of serial serum electrophoretic pattern for prognosis in various cancer patients during irradiation

    International Nuclear Information System (INIS)

    Ra, Woo Youn; Woo, Won Hyung

    1971-01-01

    During the period from June. 1969 to Dec. 1970, the serum protein electrophoretic patterns of 44 cases of various cancer patients have been studied to determine the alterations in serum protein fractions in patients who were responding to irradiation or those failing. The serum electrophoretic pattern could be observed as an indicator of prognosis or radiosensitivity. A blood sample was obtained prior to any treatment and the follow up sampling was performed 2 times during radiation therapy. Serum total protein was determined by the method of Wolfson and serum electrophoresis was carried out by using Spinoco Model R B electrophoresis system. The results were following: Seven cases out of cases of cervical cancer responding favorably to radiotherapy showed decreased in Alpha-2 globulin fraction were increased. A case whose third time serum electrophoretic pattern showed multiple myeloma type died 5 months after radiotherapy with bone metastasis. Four cases out of 9 cases of favorably responded breast cancer patients showed decreased in Alpha-2 globulin foraction compared with 2 cases of unfavorable response showed increased in Alpha-2 globulin fraction

  4. Studies of serial serum electrophoretic pattern for prognosis in various cancer patients during irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ra, Woo Youn; Woo, Won Hyung [Kyungpook National University School of Medicine, Taegu (Korea, Republic of)

    1971-10-15

    During the period from June. 1969 to Dec. 1970, the serum protein electrophoretic patterns of 44 cases of various cancer patients have been studied to determine the alterations in serum protein fractions in patients who were responding to irradiation or those failing. The serum electrophoretic pattern could be observed as an indicator of prognosis or radiosensitivity. A blood sample was obtained prior to any treatment and the follow up sampling was performed 2 times during radiation therapy. Serum total protein was determined by the method of Wolfson and serum electrophoresis was carried out by using Spinoco Model R B electrophoresis system. The results were following: Seven cases out of cases of cervical cancer responding favorably to radiotherapy showed decreased in Alpha-2 globulin fraction were increased. A case whose third time serum electrophoretic pattern showed multiple myeloma type died 5 months after radiotherapy with bone metastasis. Four cases out of 9 cases of favorably responded breast cancer patients showed decreased in Alpha-2 globulin foraction compared with 2 cases of unfavorable response showed increased in Alpha-2 globulin fraction.

  5. Electrophoretic properties of BSA-coated quantum dots.

    Science.gov (United States)

    Bücking, Wendelin; Massadeh, Salam; Merkulov, Alexei; Xu, Shu; Nann, Thomas

    2010-02-01

    Low toxic InP/ZnS quantum dots (QDs), ZnS:Mn(2+)/ZnS nanocrystals and CdSe/ZnS nanoparticles were rendered water-dispersible by different ligand-exchange methods. Eventually, they were coated with bovine serum albumin (BSA) as a model protein. All particles were characterised by isotachophoresis (ITP), laser Doppler velocimetry (LDV) and agarose gel electrophoresis. It was found that the electrophoretic mobility and colloidal stability of ZnS:Mn(2+)/ZnS and CdSe/ZnS nanoparticles, which bore short-chain surface ligands, was primarily governed by charges on the nanoparticles, whereas InP/ZnS nanocrystals were not charged per se. BSA-coated nanoparticles showed lower electrophoretic mobility, which was attributed to their larger size and smaller overall charge. However, these particles were colloidally stable. This stability was probably caused by steric stabilisation of the BSA coating.

  6. Perfil hematológico e avaliação eletroforética das proteínas séricas de cães com cinomose Hematological profile and electrophoretic evaluation of serum proteins of dogs with canine distemper

    OpenAIRE

    I.N.G. Silva; M.I.F. Guedes; M.F.G. Rocha; C.M.O. Medeiros; L.C. Oliveira; O.C. Moreira; M.F.S. Teixeira

    2005-01-01

    The hematological and serum proteins electrophoretic profiles of 13 dogs with distemper (Lentz inclusion body in leukocytes) were studied. The most frequent hematological findings were: normocitic normocromic anemia (61%), leukopenia (46%), left shount (54%), trombocytopenia (69%) and lymphopenia (85%). Electrophoretic analysis of serum proteins showed hypoproteinemia (54%), with reduced albumin and increased alfa-2 globulin. These findings can be used to support the clinical diagnosis of can...

  7. An electrophoretical and immunological study of Pycnogonida, with phylogenetic considerations

    NARCIS (Netherlands)

    Munilla, Tomás; Haro, de Andrés

    1981-01-01

    An electrophoretical and immunological study is made of nine species of pycnogonids, representing seven families, from the Catalan coast. An electrophoretogram of each species is given and the antigenic properties of its protein bands are determined. Taking as comparative basis the serological

  8. Evaluation of different protein extraction methods for banana (Musa spp.) root proteome analysis by two-dimensional electrophoresis.

    Science.gov (United States)

    Vaganan, M Mayil; Sarumathi, S; Nandakumar, A; Ravi, I; Mustaffa, M M

    2015-02-01

    Four protocols viz., the trichloroacetic acid-acetone (TCA), phenol-ammonium acetate (PAA), phenol/SDS-ammonium acetate (PSA) and trisbase-acetone (TBA) were evaluated with modifications for protein extraction from banana (Grand Naine) roots, considered as recalcitrant tissues for proteomic analysis. The two-dimensional electrophoresis (2-DE) separated proteins were compared based on protein yield, number of resolved proteins, sum of spot quantity, average spot intensity and proteins resolved in 4-7 pI range. The PAA protocol yielded more proteins (0.89 mg/g of tissues) and protein spots (584) in 2-DE gel than TCA and other protocols. Also, the PAA protocol was superior in terms of sum of total spot quantity and average spot intensity than TCA and other protocols, suggesting phenol as extractant and ammonium acetate as precipitant of proteins were the most suitable for banana rooteomics analysis by 2-DE. In addition, 1:3 ratios of root tissue to extraction buffer and overnight protein precipitation were most efficient to obtain maximum protein yield.

  9. Ultrastructure and electrophoretic protein pattern of a nuclear fraction enriched in interchromatin granule conglomerations

    Energy Technology Data Exchange (ETDEWEB)

    Krzyzowska-Gruca, S.; Zborek, A.; Gruca, S.

    1986-01-01

    Rats were injected with a cytostatic 1-nitro-9/3'-dimethylpropyloamine/acridine.2HCl to induce aggregation of interchromatin granules (IG). The conglomerations of IG were well preserved in isolated liver nuclei and in nuclear structures deprived of chromatin. This feature enabled obtaining a nuclear fraction enriched in IG. The method consisted in extraction of isolated nuclei with a non-ionic detergent and digestion with DNase I in a high ionic strength. Each step of isolation was ultrastructurally monitored using both the routine electron microscopy as well as a preferential staining of IG with bismuth. Presence of spots of tightly packed granules within IG conglomerations in the final fraction like in the nuclei in situ was a good ultrastructural marker of IG. The resulting fraction consisted predominantly of IG conglomerations. Their preferential staining with bismuth was well preserved. Minute amounts of fibrillar material originating from nuclear matrix and residual nuclei could be observed. Protein composition of the fraction enriched in IG was studied by SDS-polyacrylamide gel electrophoresis. After electrotransfer, nitrocellulose filters were fixed with glutaraldehyde and stained with bismuth method in order to identify IG proteins. The results of ultrastructural and cytochemical studies in comparison to electrophoretic protein pattern are discussed.

  10. Perfil hematológico e avaliação eletroforética das proteínas séricas de cães com cinomose Hematological profile and electrophoretic evaluation of serum proteins of dogs with canine distemper

    Directory of Open Access Journals (Sweden)

    I.N.G. Silva

    2005-02-01

    Full Text Available The hematological and serum proteins electrophoretic profiles of 13 dogs with distemper (Lentz inclusion body in leukocytes were studied. The most frequent hematological findings were: normocitic normocromic anemia (61%, leukopenia (46%, left shount (54%, trombocytopenia (69% and lymphopenia (85%. Electrophoretic analysis of serum proteins showed hypoproteinemia (54%, with reduced albumin and increased alfa-2 globulin. These findings can be used to support the clinical diagnosis of canine distemper.

  11. Phosphorylation of ribosomal proteins induced by auxins in maize embryonic tissues

    International Nuclear Information System (INIS)

    Perez, L.; Aguilar, R.; Mendez, A.P.; de Jimenez, E.S.

    1990-01-01

    The effect of auxin on ribosomal protein phosphorylation of germinating maize (Zea mays) tissues was investigated. Two-dimensional gel electrophoresis and autoradiography of [ 32 P] ribosomal protein patterns for natural and synthetic auxin-treated tissues were performed. Both the rate of 32 P incorporation and the electrophoretic patterns were dependent on 32 P pulse length, suggesting that active protein phosphorylation-dephosphorylation occurred in small and large subunit proteins, in control as well as in auxin-treated tissues. The effect of ribosomal protein phosphorylation on in vitro translation was tested. Measurements of poly(U) translation rates as a function of ribosome concentration provided apparent K m values significantly different for auxin-treated and nontreated tissues. These findings suggest that auxin might exert some kind of translational control by regulating the phosphorylated status of ribosomal proteins

  12. Protein phosphorylation systems in postmortem human brain

    International Nuclear Information System (INIS)

    Walaas, S.I.; Perdahl-Wallace, E.; Winblad, B.; Greengard, P.

    1989-01-01

    Protein phosphorylation systems regulated by cyclic adenosine 3',5'-monophosphate (cyclic AMP), or calcium in conjunction with calmodulin or phospholipid/diacylglycerol, have been studied by phosphorylation in vitro of particulate and soluble fractions from human postmortem brain samples. One-dimensional or two-dimensional gel electrophoretic protein separations were used for analysis. Protein phosphorylation catalyzed by cyclic AMP-dependent protein kinase was found to be highly active in both particulate and soluble preparations throughout the human CNS, with groups of both widely distributed and region-specific substrates being observed in different brain nuclei. Dopamine-innervated parts of the basal ganglia and cerebral cortex contained the phosphoproteins previously observed in rodent basal ganglia. In contrast, calcium/phospholipid-dependent and calcium/calmodulin-dependent protein phosphorylation systems were less prominent in human postmortem brain than in rodent brain, and only a few widely distributed substrates for these protein kinases were found. Protein staining indicated that postmortem proteolysis, particularly of high-molecular-mass proteins, was prominent in deeply located, subcortical regions in the human brain. Our results indicate that it is feasible to use human postmortem brain samples, when obtained under carefully controlled conditions, for qualitative studies on brain protein phosphorylation. Such studies should be of value in studies on human neurological and/or psychiatric disorders

  13. A combined classical genetic and high resolution two-dimensional electrophoretic approach to the assessment of the number of genes affecting hybrid male sterility in Drosophila simulans and Drosophila sechellia.

    Science.gov (United States)

    Zeng, L W; Singh, R S

    1993-09-01

    We have attempted to estimate the number of genes involved in postzygotic reproductive isolation between two closely related species, Drosophila simulans and Drosophila sechellia, by a novel approach that involves the use of high resolution two-dimensional gel electrophoresis (2DE) to examine testis proteins in parents, hybrids and fertile and sterile backcross progenies. The important results that have emerged from this study are as follows: (1) about 8% of about 1000 proteins examined showed divergence (presence/absence) between the two species; (2) by tracing individual proteins in parental, hybrid and backcross males, we were able to associate the divergent proteins with different chromosomes and found that most divergent proteins are associated with autosomes and very few with X chromosome, Y chromosome and cytoplasm; (3) when proteins showing both quantitative and qualitative differences between the two species were examined in F1 hybrid males, most (97.4%) proteins were expressed at levels between the two parents and no sign of large scale changes in spot density was observed. All the proteins observed in the two parental species were present in F1 hybrid males except two species-specific proteins that may be encoded (or regulated) by sex chromosomes; (4) when different fertile and sterile backcross male testes were compared, a few D. sechellia-specific proteins were identified to be consistently associated with male sterility. These results along with the observation that a large proportion (23.6%) of first generation backcross males were fertile show that hybrid male sterility between D. simulans and D. sechellia involves a relatively small number of genes. Role of large scale genetic changes due to general genome incompatibility is not supported. The results also suggest that the large effect of X chromosome on hybrid male sterility is not due to higher divergence of X chromosome than autosomes.

  14. Mapping of Chlamydia trachomatis proteins by immobiline-polyacrylamide two-dimensional electrophoresis: spot identification by N-terminal sequencing and immunoblotting

    DEFF Research Database (Denmark)

    Bini, L; Sanchez-Campillo, M; Santucci, A

    1996-01-01

    Proteins from purified elementary bodies of Chlamydia trachomatis were separated by two-dimensional gel electrophoresis on nonlinear wide-range immobilized pH gradients in the first dimension and polyacrylamide gradient gels in the second dimension. The maps obtained with this system are highly...

  15. Muscle protein analysis. II. Two-dimensional electrophoresis of normal and diseased human skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Giometti, C.S. (Argonne National Lab., IL); Barany, M.; Danon, M.J.; Anderson, N.G.

    1980-07-01

    High-resolution two-dimensional electrophoresis was used to analyze the major proteins of normal and pathological human-muscle samples. The normal human-muscle pattern contains four myosin light chains: three that co-migrate with the myosin light chains from rabbit fast muscle (extensor digitorum longus), and one that co-migrates with the light chain 2 from rabbit slow muscle (soleus). Of seven Duchenne muscular dystrophy samples, four yielded patterns with decreased amounts of actin and myosin relative to normal muscle, while three samples gave patterns comparable to that for normal muscle. Six samples from patients with myotonic dystrophy also gave normal patterns. In nemaline rod myopathy, in contrast, the pattern was deficient in two of the fast-type myosin light chains.

  16. Comparison of protein patterns after two-dimensional gel electrophoresis from leaves of in vitro cultures and seedlings of Rubus chamaemorus L.

    Directory of Open Access Journals (Sweden)

    Barbara Thiem

    2014-01-01

    Full Text Available Proteins from leaves of Rubus chamaemorus propagated in vitro were subjected to miniaturized 2-D electrophoresis. The 2-DE patterns of proteins showed qualitative differences between plants propagated in vitro and control seedlings. More proteins of a high molecular weight were observed in leaves of plants from in vitro culture. A two-dimensional map of proteins from leaves provides detailed data concerning both polymorphism and protein patterns of this species. This makes it possible to start constructing a protein map of R. chamaemorus. The reasons for qualitative differences are discussed.

  17. Effect of vitamin D status on chick kidney proteins: detection of a 45-kilodalton mitochondrial protein suppressed by vitamin D

    International Nuclear Information System (INIS)

    Kain, S.R.; Kamrath, K.S.; Henry, H.L.

    1988-01-01

    Two-dimensional polyacrylamide gel electrophoresis along with L-[ 35 S]methionine radiolabeling studies were used to examine the effect of chronic vitamin D status on the composition and relative abundance of chick kidney proteins. Comparison of silver-stained gels revealed no extensive differences in either the electrophoretic mobility or the amounts of kidney proteins present in the mitochondrial fraction from vitamin D-replete and vitamin D-deficient chicks. A similar result was obtained in studies with L-[ 35 S]methionine-labeled proteins. Vitamin D deficiency specifically elevated levels of a 45-kilodalton mitochondrial protein (pI 5.0 to 5.5) by approximately 5- to 12-fold relative to amounts present in vitamin D-replete tissue. This protein could not be detected in postmitochondrial supernatant fractions and was only faintly visible in crude kidney homogenates. The specificity of the observed suppression of this 45-kilodalton protein by vitamin D suggests that it may play an important role in renal functions influenced by the vitamin D endocrine system

  18. Analysis of Two-Dimensional Electrophoresis Gel Images

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2002-01-01

    This thesis describes and proposes solutions to some of the currently most important problems in pattern recognition and image analysis of two-dimensional gel electrophoresis (2DGE) images. 2DGE is the leading technique to separate individual proteins in biological samples with many biological...

  19. Two Dimensional Electrophoresis of Proteins from Cultures of Erysiphe graminis f.sp. hordei

    DEFF Research Database (Denmark)

    Torp, J.; Andersen, Brian

    1982-01-01

    Conidial proteins from barley powdery mildew, Erysiphe graminis f. sp. hordei, were separated by 2-dimensional electrophoresis in polyacrylamide slab gels. Isoelectric focusing was used in the first dimension and separation according to molecular weight in a gel containing sodium dodecyl sulphate...

  20. Separation and identification of Musa acuminate Colla (banana) leaf proteins by two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Lu, Y; Qi, Y X; Zhang, H; Zhang, H Q; Pu, J J; Xie, Y X

    2013-12-19

    To establish a proteomic reference map of Musa acuminate Colla (banana) leaf, we separated and identified leaf proteins using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS). Tryptic digests of 44 spots were subjected to peptide mass fingerprinting (PMF) by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS. Three spots that were not identified by MALDI-TOF MS analysis were identified by searching against the NCBInr, SwissProt, and expressed sequence tag (EST) databases. We identified 41 unique proteins. The majority of the identified leaf proteins were found to be involved in energy metabolism. The results indicate that 2D-PAGE is a sensitive and powerful technique for the separation and identification of Musa leaf proteins. A summary of the identified proteins and their putative functions is discussed.

  1. Optimized Protocol for Protein Extraction from the Breast Tissue that is Compatible with Two-Dimensional Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Olena Zakharchenko

    2011-01-01

    Full Text Available Proteomics is a highly informative approach to analyze cancer-associated transformation in tissues. The main challenge to use a tissue for proteomics studies is the small sample size and difficulties to extract and preserve proteins. The choice of a buffer compatible with proteomics applications is also a challenge. Here we describe a protocol optimized for the most efficient extraction of proteins from the human breast tissue in a buffer compatible with two-dimensional gel electrophoresis (2D-GE. This protocol is based on mechanically assisted disintegration of tissues directly in the 2D-GE buffer. Our method is simple, robust and easy to apply in clinical practice. We demonstrate high quality of separation of proteins prepared according to the reported here protocol.

  2. Explorative data analysis of two-dimensional electrophoresis gels

    DEFF Research Database (Denmark)

    Schultz, J.; Gottlieb, D.M.; Petersen, Marianne Kjerstine

    2004-01-01

    of gels is presented. First, an approach is demonstrated in which no prior knowledge of the separated proteins is used. Alignment of the gels followed by a simple transformation of data makes it possible to analyze the gels in an automated explorative manner by principal component analysis, to determine......Methods for classification of two-dimensional (2-DE) electrophoresis gels based on multivariate data analysis are demonstrated. Two-dimensional gels of ten wheat varieties are analyzed and it is demonstrated how to classify the wheat varieties in two qualities and a method for initial screening...... if the gels should be further analyzed. A more detailed approach is done by analyzing spot volume lists by principal components analysis and partial least square regression. The use of spot volume data offers a mean to investigate the spot pattern and link the classified protein patterns to distinct spots...

  3. Electrophoretic studies on rape seed proteins

    International Nuclear Information System (INIS)

    Chaudry, M.A.; Starr, A.; Bibi, N.

    1992-07-01

    Electrophoresis is a technique which separates biological molecules on the basis of charge and mass properties. The technique is used for separation, purification, characterization and identification of molecules/ compounds. Two major objectives for applications of electrophoresis have been studied in this report i.e. characterization of rape seed proteins and enzymes and identification of rape seed cultivars by polyacrylamide gel electrophoresis (PAGE). Gamma irradiation is being successfully used to create genetic variability and germination which brought about definite changes in the rape seed proteins reflected in different bands. These differences could be used to study variability in crop plants. (A.B.)

  4. Evaluation of photo destruction of chromophores of heme and globin components in UV-irradiated human carboxyhemoglobin and its electrophoretic fractions

    International Nuclear Information System (INIS)

    Putintseva, O.V.; Artykhov, V.G.; Kalaeva, E.A.

    2000-01-01

    The contribution of hem and globin components of electrophoretic fractions of UV-irradiated human carboxyhemoglobin to photo destruction of the protein was studied. The changes observed are the result of summation of some processes unequal in intensity and direction that take place in microgeterogenous media of photo modified protein. Photo sensitivity of hemoproteid in electrophoretic fraction depends on apoprotein condition, whereas the hem photo resistance cannot be the evidence of the photo stability of the whole molecule [ru

  5. Human lymphocyte polymorphisms detected by quantitative two-dimensional electrophoresis

    International Nuclear Information System (INIS)

    Goldman, D.; Merril, C.R.

    1983-01-01

    A survey of 186 soluble lymphocyte proteins for genetic polymorphism was carried out utilizing two-dimensional electrophoresis of 14 C-labeled phytohemagglutinin (PHA)-stimulated human lymphocyte proteins. Nineteen of these proteins exhibited positional variation consistent with independent genetic polymorphism in a primary sample of 28 individuals. Each of these polymorphisms was characterized by quantitative gene-dosage dependence insofar as the heterozygous phenotype expressed approximately 50% of each allelic gene product as was seen in homozygotes. Patterns observed were also identical in monozygotic twins, replicate samples, and replicate gels. The three expected phenotypes (two homozygotes and a heterozygote) were observed in each of 10 of these polymorphisms while the remaining nine had one of the homozygous classes absent. The presence of the three phenotypes, the demonstration of gene-dosage dependence, and our own and previous pedigree analysis of certain of these polymorphisms supports the genetic basis of these variants. Based on this data, the frequency of polymorphic loci for man is: P . 19/186 . .102, and the average heterozygosity is .024. This estimate is approximately 1/3 to 1/2 the rate of polymorphism previously estimated for man in other studies using one-dimensional electrophoresis of isozyme loci. The newly described polymorphisms and others which should be detectable in larger protein surveys with two-dimensional electrophoresis hold promise as genetic markers of the human genome for use in gene mapping and pedigree analyses

  6. Electron cryomicroscopy of two-dimensional crystals of the H+-ATPase from chloroplasts

    NARCIS (Netherlands)

    Böttcher, Bettina; Gräber, Peter; Boekema, Egbert J.; Lücken, Uwe

    1995-01-01

    The H+-ATPase from spinach chloroplasts was isolated and purified. Two-dimensional crystals were obtained from the protein/lipid/detergent micelles by treatment with phospholipase and simultaneous removal of detergent and fatty acids by Biobeads. The resulting two-dimensionally ordered arrays were

  7. Proteome analysis of barley seeds: Identification of major proteins from two-dimensional gels (pl 4-7)

    DEFF Research Database (Denmark)

    Østergaard, O.; Finnie, Christine; Laugesen, S.

    2004-01-01

    inhibitors), and proteins related to desiccation and oxidative stress. Sixty-four of the identifications were made using expressed sequence tags (ESTs). Numerous spots in the 2-D gel pattern changed during germination (micromalting) and an intensely stained area which contained large amounts of the serpin......Germination of monocotyledonous plants involves activation and de novo synthesis of enzymes that degrade cell walls and starch and mobilize stored endosperm reserves for embryo growth. Two-dimensional (2-D) gel electrophoresis and mass spectrometry were applied to identify major water...

  8. Two-dimensional errors

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter addresses the extension of previous work in one-dimensional (linear) error theory to two-dimensional error analysis. The topics of the chapter include the definition of two-dimensional error, the probability ellipse, the probability circle, elliptical (circular) error evaluation, the application to position accuracy, and the use of control systems (points) in measurements

  9. Determination of the Median Lethal Dose and Electrophoretic Pattern of Hottentotta saulcyi (Scorpiones, Buthidae Scorpion Venom

    Directory of Open Access Journals (Sweden)

    ErsenAydın Yağmur

    2015-10-01

    Full Text Available Background: In this study, we investigated the lethal potency, electrophoretic protein pattern and in vivo effects of Hottentotta saulcyi scorpion venom in mice.Methods: Scorpions were collected at night, by using a UV lamp from Mardin Province, Turkey. Venom was obtained from mature H. saulcyi scorpions by electrical stimulation of the telson. The lethality of the venom was determined by i.v. injections using Swiss mice. In vivo effects of the venom were assessed by using the intraperitoneal route (ip injections into mice (20±1g and monitored for 24 h. The protein profiles of the scorpion venom were analyzed by NuPAGE® Novex® 4–12 % gradient Bis-Tris gel followed by Coomassie blue staining.Results: The lethal assay of the venom was 0.73 mg/kg in mice. We determined the electrophoretic protein pattern of this scorpion venom to be 4, 6, 9, 31, 35, 40, 46 and 69 kDa by SDS-PAGE. Analysis of electrophoresis indicated that H. saulcyi scorpion intoxicated mice exhibited autonomic nervous system symptoms (tachypnea, restlessness, hyperexcitability, convulsions, salivation, lacrimation, weakness.Conclusions: Hottentotta saulcyi scorpion venom includes short-chain neurotoxins and long-chain neurotoxins according to the electrophoretic protein patterns. The stings of H. saulcyi scorpion must be considered of risk for humans in the southeastern region, Turkey.

  10. Two-dimensional polyacrylamide gel analysis of Plodia interpunctella granulosis virus

    International Nuclear Information System (INIS)

    Russell, D.L.; Consigli, R.A.

    1986-01-01

    The structural polypeptides of purified Plodia interpunctella granulosis virus were analyzed by three different two-dimensional gel systems. Isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed resolution of 53 acidic polypeptides in the enveloped nucleocapsid of the virus ranging in molecular weight from 97,300 to 8000. Nine of these polypeptides were shown to be glycoproteins by the technique of radiolabeled lectin blotting. Separation of the granulin in this system allowed resolution of five species, all of which have identical tryptic peptide maps. This matrix protein was demonstrated to be a phosphoglycoprotein by radiolabeled lectin blotting and acid phosphatase dephosphorylation. Nonequilibrium pH gel electrophoresis followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed resolution of the major basic protein of the virus, VP12, from a more acidic protein of the same molecular weight. Tryptic peptide analysis demonstrated that these two proteins were indeed different and acid urea gels followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed localization of the acidic protein to the envelope and the basic protein to the nucleocapsid of the virus. Finally, probing of the separated envelope nucleocapsid proteins in both the isoelectric focusing and nonequilibrium pH gel electrophoresis two-dimensional systems after transfer to nitrocellulose with iodinated, purified viral proteins allowed further insight into reactions which may be important in the maintenance of the virion structure

  11. ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

    Directory of Open Access Journals (Sweden)

    Nikola Stefanović

    2007-06-01

    Full Text Available In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic leadership style, leadership theory researchers use two dimensional matrices. The two-dimensional matrices define leadership styles on the basis of different parameters. By using these parameters, one can identify two-dimensional styles.

  12. Sex-specific and blood meal-induced proteins of Anopheles gambiae midguts: analysis by two-dimensional gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Laurent-Winter C

    2003-02-01

    Full Text Available Abstract Background Anopheles gambiae is the main vector of Plasmodium falciparum in Africa. The mosquito midgut constitutes a barrier that the parasite must cross if it is to develop and be transmitted. Despite the central role of the mosquito midgut in the host/parasite interaction, little is known about its protein composition. Characterisation of An. gambiae midgut proteins may identify the proteins that render An. gambiae receptive to the malaria parasite. Methods We carried out two-dimensional gel electrophoresis of An. gambiae midgut proteins and compared protein profiles for midguts from males, sugar-fed females and females fed on human blood. Results Very few differences were detected between male and female mosquitoes for the approximately 375 silver-stained proteins. Male midguts contained ten proteins not detected in sugar-fed or blood-fed females, which are therefore probably involved in male-specific functions; conversely, female midguts contained twenty-three proteins absent from male midguts. Eight of these proteins were specific to sugar-fed females, and another ten, to blood-fed females. Conclusion Mass spectrometry analysis of the proteins found only in blood-fed female midguts, together with data from the recent sequencing of the An. gambiae genome, should make it possible to determine the role of these proteins in blood digestion or parasite receptivity.

  13. Effects of interferon gamma on Chlamydia trachomatis serovar A and L2 protein expression investigated by two-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Shaw, A; Christiansen, Gunna; Birkelund, Svend

    1999-01-01

    ]methionine and two-dimensional gel electrophoresis with immobilized pH gradients in order to investigate changes in the protein expression of C. trachomatis serovar A and L2 caused by treatment with IFN-gamma. In contrast to what was observed in C. trachomatis L2, our results showed that, in C. trachomatis A, down...

  14. Identification of liver protein targets modified by tienilic acid metabolites using a two-dimensional Western blot-mass spectrometry approach

    Science.gov (United States)

    Methogo, Ruth Menque; Dansette, Patrick M.; Klarskov, Klaus

    2007-12-01

    A combined approach based on two-dimensional electrophoresis-immuno-blotting and nanoliquid chromatography coupled on-line with electrospray ionization mass spectrometry (nLC-MS/MS) was used to identify proteins modified by a reactive intermediate of tienilic acid (TA). Liver homogenates from rats exposed to TA were fractionated using ultra centrifugation; four fractions were obtained and subjected to 2D electrophoresis. Following transfer to PVDF membranes, modified proteins were visualized after India ink staining, using an anti-serum raised against TA and ECL detection. Immuno-reactive spots were localized on the PVDF membrane by superposition of the ECL image, protein spots of interest were excised, digested on the membrane with trypsin followed by nLC-MS/MS analysis and protein identification. A total of 15 proteins were identified as likely targets modified by a TA reactive metabolite. These include selenium binding protein 2, senescence marker protein SMP-30, adenosine kinase, Acy1 protein, adenosylhomocysteinase, capping protein (actin filament), protein disulfide isomerase, fumarylacetoacetase, arginase chain A, ketohexokinase, proteasome endopeptidase complex, triosephosphate isomerase, superoxide dismutase, dna-type molecular chaperone hsc73 and malate dehydrogenase.

  15. Proteomic analysis of differential protein expression of achilles tendon in a rabbit model by two-dimensional polyacrylamide gel electrophoresis at 21 days postoperation.

    Science.gov (United States)

    Jielile, Jiasharete; Jialili, Ainuer; Sabirhazi, Gulnur; Shawutali, Nuerai; Redati, Darebai; Chen, Jiangtao; Tang, Bin; Bai, Jingping; Aldyarhan, Kayrat

    2011-10-01

    Postoperative early kinesitherapy has been advocated as an optimal method for treating Achilles tendon rupture. However, an insight into the rationale of how early kinesitherapy contributes to healing of Achilles tendon remains to be achieved, and research in the area of proteomic analysis of Achilles tendon has so far been lacking. Forty-two rabbits were randomized into control group, immobilization group, and early motion group, and received postoperative cast immobilization and early motion treatments. Achilles tendon samples were prepared 21 days following microsurgery, and the proteins were separated with two-dimensional polyacrylamide gel electrophoresis. Differentially expressed proteins were first recognized by PDQuest software, and then identified using peptide mass fingerprinting, tandem mass spectrometry, and database searching. A total of 463  ±  12, 511  ±  39, and 513  ±  80 protein spots were successfully detected in the two-dimensional polyacrylamide gels for the Achilles tendon samples of rabbits in the control group, immobilization group, and early motion group, respectively. There were 15, 8, and 9 unique proteins in these three groups, respectively, and some differentially expressed proteins were also identified in each group. It was indicated that some of the differentially expressed proteins were involved in various metabolism pathways and may play an important role in healing of Achilles tendon rupture. Postoperative early kinesitherapy resulted in differentially expressed proteins in ruptured Achilles tendon compared with those treated with postoperative cast immobilization. These differentially expressed proteins may contribute to healing of Achilles tendon rupture through a mechanobiological mechanism due to the application of postoperative early kinesitherapy.

  16. Two-dimensional chromatographic analysis using three second-dimension columns for continuous comprehensive analysis of intact proteins.

    Science.gov (United States)

    Zhu, Zaifang; Chen, Huang; Ren, Jiangtao; Lu, Juan J; Gu, Congying; Lynch, Kyle B; Wu, Si; Wang, Zhe; Cao, Chengxi; Liu, Shaorong

    2018-03-01

    We develop a new two-dimensional (2D) high performance liquid chromatography (HPLC) approach for intact protein analysis. Development of 2D HPLC has a bottleneck problem - limited second-dimension (second-D) separation speed. We solve this problem by incorporating multiple second-D columns to allow several second-D separations to be proceeded in parallel. To demonstrate the feasibility of using this approach for comprehensive protein analysis, we select ion-exchange chromatography as the first-dimension and reverse-phase chromatography as the second-D. We incorporate three second-D columns in an innovative way so that three reverse-phase separations can be performed simultaneously. We test this system for separating both standard proteins and E. coli lysates and achieve baseline resolutions for eleven standard proteins and obtain more than 500 peaks for E. coli lysates. This is an indication that the sample complexities are greatly reduced. We see less than 10 bands when each fraction of the second-D effluents are analyzed by sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE), compared to hundreds of SDS-PAGE bands as the original sample is analyzed. This approach could potentially be an excellent and general tool for protein analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Two-dimensional NMR spectrometry

    International Nuclear Information System (INIS)

    Farrar, T.C.

    1987-01-01

    This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t 0 ; an evolution period, t 1 ; and a detection period, t 2

  18. The time-course of agonist-induced solubilization of trimeric Gqα/G11α proteins resolved by two-dimensional electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Durchánková, Dana; Novotný, Jiří; Svoboda, Petr

    2008-01-01

    Roč. 57, č. 2 (2008), s. 195-203 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA MŠk(CZ) LC06063; GA ČR(CZ) GA309/06/0121 Institutional research plan: CEZ:AV0Z50110509 Keywords : G proteins * solubilization * two-dimensional electrophoresis Subject RIV: CE - Biochemistry Impact factor: 1.653, year: 2008

  19. Noise-induced drift in two-dimensional anisotropic systems

    Science.gov (United States)

    Farago, Oded

    2017-10-01

    We study the isothermal Brownian dynamics of a particle in a system with spatially varying diffusivity. Due to the heterogeneity of the system, the particle's mean displacement does not vanish even if it does not experience any physical force. This phenomenon has been termed "noise-induced drift," and has been extensively studied for one-dimensional systems. Here, we examine the noise-induced drift in a two-dimensional anisotropic system, characterized by a symmetric diffusion tensor with unequal diagonal elements. A general expression for the mean displacement vector is derived and presented as a sum of two vectors, depicting two distinct drifting effects. The first vector describes the tendency of the particle to drift toward the high diffusivity side in each orthogonal principal diffusion direction. This is a generalization of the well-known expression for the noise-induced drift in one-dimensional systems. The second vector represents a novel drifting effect, not found in one-dimensional systems, originating from the spatial rotation in the directions of the principal axes. The validity of the derived expressions is verified by using Langevin dynamics simulations. As a specific example, we consider the relative diffusion of two transmembrane proteins, and demonstrate that the average distance between them increases at a surprisingly fast rate of several tens of micrometers per second.

  20. A stable and convenient protein electrophoresis titration device with bubble removing system.

    Science.gov (United States)

    Zhang, Qiang; Fan, Liu-Yin; Li, Wen-Lin; Cong, Feng-Song; Zhong, Ran; Chen, Jing-Jing; He, Yu-Chen; Xiao, Hua; Cao, Cheng-Xi

    2017-07-01

    Moving reaction boundary titration (MRBT) has a potential application to immunoassay and protein content analysis with high selectivity. However, air bubbles often impair the accuracy of MRBT, and the leakage of electrolyte greatly decreases the safety and convenience of electrophoretic titration. Addressing these two issues a reliable MRBT device with modified electrolyte chamber of protein titration was designed. Multiphysics computer simulation was conducted for optimization according to two-phase flow. The single chamber was made of two perpendicular cylinders with different diameters. After placing electrophoretic tube, the resident air in the junction next to the gel could be eliminated by a simple fast electrolyte flow. Removing the electrophoretic tube automatically prevented electrolyte leakage at the junction due to the gravity-induced negative pressure within the chamber. Moreover, the numerical simulation and experiments showed that the improved MRBT device has following advantages: (i) easy and rapid setup of electrophoretic tube within 20 s; (ii) simple and quick bubble dissipates from the chamber of titration within 2 s; (iii) no electrolyte leakage from the two chambers: and (iv) accurate protein titration and safe instrumental operation. The developed technique and apparatus greatly improves the performance of the previous MRBT device, and providing a new route toward practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Electrophoretic characterization of protein interactions suggesting limited feasibility of accelerated shelf-life testing of ultra-high temperature milk.

    Science.gov (United States)

    Grewal, Manpreet Kaur; Chandrapala, Jayani; Donkor, Osaana; Apostolopoulos, Vasso; Vasiljevic, Todor

    2017-01-01

    Accelerated shelf-life testing is applied to a variety of products to estimate keeping quality over a short period of time. The industry has not been successful in applying this approach to ultra-high temperature (UHT) milk because of chemical and physical changes in the milk proteins that take place during processing and storage. We investigated these protein changes, applying accelerated shelf-life principles to UHT milk samples with different fat levels and using native- and sodium dodecyl sulfate-PAGE. Samples of UHT skim and whole milk were stored at 20, 30, 40, and 50°C for 28d. Irrespective of fat content, UHT treatment had a similar effect on the electrophoretic patterns of milk proteins. At the start of testing, proteins were bonded mainly through disulfide and noncovalent interactions. However, storage at and above 30°C enhanced protein aggregation via covalent interactions. The extent of aggregation appeared to be influenced by fat content; whole milk contained more fat than skim milk, implying aggregation via melted or oxidized fat, or both. Based on reduction in loss in absolute quantity of individual proteins, covalent crosslinking in whole milk was facilitated mainly by products of lipid oxidation and increased access to caseins for crosslinking reactions. Maillard and dehydroalanine products were the main contributors involved in protein changes in skim milk. Protein crosslinking appeared to follow a different pathway at higher temperatures (≥40°C) than at lower temperatures, making it very difficult to extrapolate these changes to protein interactions at lower temperatures. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Application of zwitterionic detergent to the solubilization of Klebsiella pneumoniae outer membrane proteins for two-dimensional gel electrophoresis.

    Science.gov (United States)

    Bednarz-Misa, I; Serek, P; Dudek, B; Pawlak, A; Bugla-Płoskońska, G; Gamian, A

    2014-12-01

    Klebsiella pneumoniae is a frequent cause of nosocomial respiratory, urinary and gastrointestinal tract infections and septicemia with the multidrug-resistant K. pneumoniae being a major public health concern. Outer membrane proteins (OMPs) are important virulence factors responsible for the appropriate adaptation to the host environment. They constitute of the antigens being the first in contact with infected organism. However, K. pneumoniae strains are heavily capsulated and it is important to establish the OMPs isolation procedure prior to proteomics extensive studies. In this study we used Zwittergent Z 3-14® as a detergent to isolate the OMPs from K. pneumoniae cells and resolve them using two-dimensional electrophoresis (2-DE). As a result we identified 134 protein spots. The OMPs identified in this study are possible candidates for the development of a protein-based vaccine against K. pneumoniae infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Electrophoretic mobilities of dissolved polyelectrolyte charging agent and suspended non-colloidal titanium during electrophoretic deposition

    International Nuclear Information System (INIS)

    Lau, Kok-Tee; Sorrell, C.C.

    2011-01-01

    Coarse (≤20 μm) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of ∼1-12 μm size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti, establishment of

  4. Electrophoretic mobilities of dissolved polyelectrolyte charging agent and suspended non-colloidal titanium during electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Kok-Tee [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76109 Durian Tunggal, Melaka (Malaysia); Sorrell, C.C., E-mail: C.Sorrell@unsw.edu.au [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2011-03-25

    Coarse ({<=}20 {mu}m) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of {approx}1-12 {mu}m size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti

  5. High-resolution two-dimensional gel analysis of proteins in wing imaginal discs: A data base of Drosophila

    International Nuclear Information System (INIS)

    Santaren, J.F.; Garcia-Bellido, A.

    1990-01-01

    An improved method of high-resolution two-dimensional gel electrophoresis has been used to study the patterns of protein synthesis in wing imaginal discs of late instar larvae of Drosophila melanogaster. A small number of discs were radiolabeled with a mixture of 14 C-labeled amino acids or with [ 35 S]methionine and the pattern of labeled proteins was analyzed. One thousand and twenty-five polypeptides (787 acidic (IEF) and 238 basic (NEPHGE)) from wing discs of several wild-type strains have so far been separated and cataloged. All these polypeptides have been numbered and presented in a reference map for further studies. When comparing patterns of label we have found small quantitative differences in rate of synthesis between individuals of the same strain, not due to sexual differences, and very few quantitative and qualitative differences between groups of individuals of different strains

  6. Proteomic analysis of halotolerant proteins under high and low salt stress in Dunaliella salina using two-dimensional differential in-gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Yan-Long Jia

    2016-01-01

    Full Text Available Abstract Dunaliella salina, a single-celled marine alga with extreme salt tolerance, is an important model organism for studying fundamental extremophile survival mechanisms and their potential practical applications. In this study, two-dimensional differential in-gel electrophoresis (2D-DIGE was used to investigate the expression of halotolerant proteins under high (3 M NaCl and low (0.75 M NaCl salt concentrations. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS and bioinformatics were used to identify and characterize the differences among proteins. 2D-DIGE analysis revealed 141 protein spots that were significantly differentially expressed between the two salinities. Twenty-four differentially expressed protein spots were successfully identified by MALDI-TOF/TOF MS, including proteins in the following important categories: molecular chaperones, proteins involved in photosynthesis, proteins involved in respiration and proteins involved in amino acid synthesis. Expression levels of these proteins changed in response to the stress conditions, which suggests that they may be involved in the maintenance of intracellular osmotic pressure, cellular stress responses, physiological changes in metabolism, continuation of photosynthetic activity and other aspects of salt stress. The findings of this study enhance our understanding of the function and mechanisms of various proteins in salt stress.

  7. Insights into the Structural Changes Occurring upon Photoconversion in the Orange Carotenoid Protein from Broadband Two-Dimensional Electronic Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    De Re, Eleonora; Schlau-Cohen, Gabriela S.; Leverenz, Ryan L.; Huxter, Vanessa M.; Oliver, Thomas A. A.; Mathies, Richard A.; Fleming, Graham R.

    2014-05-22

    Carotenoids play an essential role in photoprotection, interacting with other pigments to safely dissipate excess absorbed energy as heat. In cyanobacteria, the short time scale photoprotective mechanisms involve the photoactive orange carotenoid protein (OCP), which binds a single carbonyl carotenoid. Blue-green light induces the photoswitching of OCP from its ground state form (OCPO) to a metastable photoproduct (OCPR). OCPR can bind to the phycobilisome antenna and induce fluorescence quenching. The photoswitching is accompanied by structural and functional changes at the level of the protein and of the bound carotenoid. In this study, we use broadband two-dimensional electronic spectroscopy to look at the differences in excited state dynamics of the carotenoid in the two forms of OCP. Our results provide insight into the origin of the pronounced vibrational lineshape and oscillatory dynamics observed in linear absorption and 2D electronic spectroscopy of OCPO and the large inhomogeneous broadening in OCPR, with consequences for the chemical function of the two forms.

  8. Phosphorylation of formate dehydrogenase in potato tuber mitochondria

    DEFF Research Database (Denmark)

    Bykova, N.V.; Stensballe, A.; Egsgaard, H.

    2003-01-01

    Two highly phosphorylated proteins were detected after two-dimensional (blue native/SDS-PAGE) gel electrophoretic separation of the matrix fraction isolated from potato tuber mitochondria. These two phosphoproteins were identified by mass spectrometry as formate dehydrogenase (FDH) and the E1alpha...

  9. Post-Electrophoretic Identification of Oxidized Proteins

    Science.gov (United States)

    Conrad, Craig C; Talent, John M; Malakowsky, Christina A

    1999-01-01

    The oxidative modification of proteins has been shown to play a major role in a number of human diseases. However, the ability to identify specific proteins that are most susceptible to oxidative modifications is difficult. Separation of proteins using polyacrylamide gel electrophoresis (PAGE) offers the analytical potential for the recovery, amino acid sequencing, and identification of thousands of individual proteins from cells and tissues. We have developed a method to allow underivatized proteins to be electroblotted onto PVDF membranes before derivatization and staining. Since both the protein and oxidation proteins are quantifiable, the specific oxidation index of each protein can be determined. The optimal sequence and conditions for the staining process are (a) electrophoresis, (b) electroblotting onto PVDF membranes, (c) derivatization of carbonyls with 2,4-DNP, (d) immunostaining with anti DNP antibody, and (e) protein staining with colloidal gold. PMID:12734585

  10. Proteomic analysis of plasma proteins in diabetic retinopathy patients by two dimensional electrophoresis and MALDI-Tof-MS.

    Science.gov (United States)

    Gopalakrishnan, Vidhya; Purushothaman, Parthiban; Bhaskar, Anusha

    2015-01-01

    Diabetic retinopathy is a highly specific vascular complication of diabetes mellitus and progresses from mild non-proliferative abnormalities characterized by increased vascular permeability to moderate and severe proliferative diabetic retinopathy characterized by the growth of blood vessels on the retina. The aim of the study was to identify the differentially expressed proteins in diabetic retinopathy using two-dimensional electrophoresis. Blood sample was drawn from subjects with diabetes mellitus (without retinopathy) who served as controls and patients with diabetic retinopathy in tubes containing EDTA as anticoagulant. Albumin and immunoglobulin IgG collectively removed to enrich proteins of lower abundance. 2de was carried out to see if there are any differentially expressed proteins. Approximately 48 and 61 spots were identified in control and diabetic retinopathy respectively, of which three protein spots RBP1 (retinol-binding protein 1), NUD10 (Diphosphoinositol polyphosphohydrolase 3 alpha), NGB (neuroglobin) were down regulated and HBG2 (hemoglobin) and BY55 (CD 160 antigen) were upregulated in diabetic retinopathy. These five protein spots were excised and were subjected to in-gel tryptic digestion, and their identities were determined by ultraflex MALDI-TOF-MS. We report a comprehensive patient-based plasma proteomic approach to the identification of potential biomarkers for diabetic retinopathy screening and detection. We identified 5 different proteins that were differentially expressed in the plasma of control diabetic patients (without retinopathy). Among these five proteins the expression of neuroglobin (NGB) protein varied significantly and may be a potential biomarker in diabetic retinopathy. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Validation of a prefractionation method followed by two-dimensional electrophoresis – Applied to cerebrospinal fluid proteins from frontotemporal dementia patients

    Directory of Open Access Journals (Sweden)

    Sjögren Magnus

    2004-11-01

    Full Text Available Abstract Background The aim of this study was firstly, to improve and validate a cerebrospinal fluid (CSF prefractionation method followed by two-dimensional electrophoresis (2-DE and secondly, using this strategy to investigate differences between the CSF proteome of frontotemporal dementia (FTD patients and controls. From each subject three ml of CSF was prefractionated using liquid phase isoelectric focusing prior to 2-DE. Results With respect to protein recovery and purification potential, ethanol precipitation of the prefractionated CSF sample was found superior, after testing several sample preparation methods. The reproducibility of prefractionated CSF analyzed on 2-D gels was comparable to direct 2-DE analysis of CSF. The protein spots on the prefractionated 2-D gels had an increased intensity, indicating a higher protein concentration, compared to direct 2-D gels. Prefractionated 2-DE analysis of FTD and control CSF showed that 26 protein spots were changed at least two fold. Using mass spectrometry, 13 of these protein spots were identified, including retinol-binding protein, Zn-α-2-glycoprotein, proapolipoproteinA1, β-2-microglobulin, transthyretin, albumin and alloalbumin. Conclusion The results suggest that the prefractionated 2-DE method can be useful for enrichment of CSF proteins and may provide a new tool to investigate the pathology of neurodegenerative diseases. This study confirmed reduced levels of retinol-binding protein and revealed some new biomarker candidates for FTD.

  12. Efficient method of protein extraction from Theobroma cacao L. roots for two-dimensional gel electrophoresis and mass spectrometry analyses.

    Science.gov (United States)

    Bertolde, F Z; Almeida, A-A F; Silva, F A C; Oliveira, T M; Pirovani, C P

    2014-07-04

    Theobroma cacao is a woody and recalcitrant plant with a very high level of interfering compounds. Standard protocols for protein extraction were proposed for various types of samples, but the presence of interfering compounds in many samples prevented the isolation of proteins suitable for two-dimensional gel electrophoresis (2-DE). An efficient method to extract root proteins for 2-DE was established to overcome these problems. The main features of this protocol are: i) precipitation with trichloroacetic acid/acetone overnight to prepare the acetone dry powder (ADP), ii) several additional steps of sonication in the ADP preparation and extractions with dense sodium dodecyl sulfate and phenol, and iii) adding two stages of phenol extractions. Proteins were extracted from roots using this new protocol (Method B) and a protocol described in the literature for T. cacao leaves and meristems (Method A). Using these methods, we obtained a protein yield of about 0.7 and 2.5 mg per 1.0 g lyophilized root, and a total of 60 and 400 spots could be separated, respectively. Through Method B, it was possible to isolate high-quality protein and a high yield of roots from T. cacao for high-quality 2-DE gels. To demonstrate the quality of the extracted proteins from roots of T. cacao using Method B, several protein spots were cut from the 2-DE gels, analyzed by tandem mass spectrometry, and identified. Method B was further tested on Citrus roots, with a protein yield of about 2.7 mg per 1.0 g lyophilized root and 800 detected spots.

  13. A comprehensive two-dimensional gel protein database of noncultured unfractionated normal human epidermal keratinocytes: towards an integrated approach to the study of cell proliferation, differentiation and skin diseases

    DEFF Research Database (Denmark)

    Celis, J E; Madsen, Peder; Rasmussen, H H

    1991-01-01

    A two-dimensional (2-D) gel database of cellular proteins from noncultured, unfractionated normal human epidermal keratinocytes has been established. A total of 2651 [35S]methionine-labeled cellular proteins (1868 isoelectric focusing, 783 nonequilibrium pH gradient electrophoresis) were resolved...

  14. Cytoskeletal proteins from human skin fibroblasts, peripheral blood leukocytes, and a lymphoblastoid cell line compared by two-dimensional gel electrophoresis

    International Nuclear Information System (INIS)

    Giometti, C.S.; Willard, K.E.; Anderson, N.L.

    1982-01-01

    Differences in proteins between cells grown as suspension cultures and those grown as attached cultures were studied by comparing the proteins of detergent-resistant cytoskeletons prepared from peripheral blood leukocytes and a lymphoblastoid cell line (GM607) (both grown as suspension cultures) and those of human skin fibroblasts (grown as attached cultures) by two-dimensional gel electrophoresis. The major cytoskeletal proteins of the leukocytes were also present in the protein pattern of GM607 cytoskeletons. In contrast, the fibroblast cytoskeletal protein pattern contained four groups of proteins that differed from the patterns of the leukocytes and GM607. In addition, surface labeling of GM607 and human fibroblasts with 125 I demonstrated that substantial amounts of vimentin and actin are exposed at the surface of the attached fibroblasts, but there is little evidence of similar exposure at the surface of the suspension-grown GM607. These results demonstrate some differences in cytoskeletal protein composition between different types of cells could be related to their ability or lack of ability to grow as attached cells in tissue culture

  15. Background-free, high sensitivity staining of proteins in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gels using a luminescent ruthenium complex.

    Science.gov (United States)

    Berggren, K; Chernokalskaya, E; Steinberg, T H; Kemper, C; Lopez, M F; Diwu, Z; Haugland, R P; Patton, W F

    2000-07-01

    SYPRO Ruby dye is a permanent stain comprised of ruthenium as part of an organic complex that interacts noncovalently with proteins. SYPRO Ruby Protein Gel Stain provides a sensitive, gentle, fluorescence-based method for detecting proteins in one-dimensional and two-dimensional sodium dodecyl sulfate-polyacrylamide gels. Proteins are fixed, stained from 3h to overnight and then rinsed in deionized water or dilute methanol/acetic acid solution for 30 min. The stain can be visualized using a wide range of excitation sources commonly used in image analysis systems including a 302 nm UV-B transilluminator, 473 nm second harmonic generation (SHG) laser, 488 nm argon-ion laser, 532 nm yttrium-aluminum-garnet (YAG) laser, xenon arc lamp, blue fluorescent light bulb or blue light-emitting diode (LED). The sensitivity of SYPRO Ruby Protein Gel Stain is superior to colloidal Coomassie Brilliant Blue (CBB) stain or monobromobimane labeling and comparable with the highest sensitivity silver or zinc-imidazole staining procedures available. The linear dynamic range of SYPRO Ruby Protein Gel stain extends over three orders of magnitude, which is vastly superior to silver, zinc-imidazole, monobromobimane and CBB stain. The fluorescent stain does not contain superfluous chemicals (formaldehyde, glutaraldehyde, Tween-20) that frequently interfere with peptide identification in mass spectrometry. While peptide mass profiles are severely altered in protein samples prelabeled with monobromobimane, successful identification of proteins by peptide mass profiling using matrix-assisted laser desorption/ionization mass spectrometry was easily performed after protein detection with SYPRO Ruby Protein Gel stain.

  16. Ocular Proteomics with Emphasis on Two-Dimensional Gel Electrophoresis and Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Honoré Bent

    2010-01-01

    Full Text Available Abstract The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE and mass spectrometry (MS. Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure reliable results. Current methods of protein staining for 2D-PAGE, protein labelling for two-dimensional difference gel electrophoresis, gel-based expression analysis and protein identification by MS are summarised. The uses of gel-free MS-based strategies (MuDPIT, iTRAQ, ICAT and SILAC are also discussed. Proteomic technologies promise to shed new light onto ocular disease processes that could lead to the discovery of strong novel biomarkers and therapeutic targets useful in many ophthalmic conditions.

  17. Crystallization of SHARPIN using an automated two-dimensional grid screen for optimization

    International Nuclear Information System (INIS)

    Stieglitz, Benjamin; Rittinger, Katrin; Haire, Lesley F.

    2012-01-01

    The expression, purification and crystallization of an N-terminal fragment of SHARPIN are reported. Diffraction-quality crystals were obtained using a two-dimensional grid-screen seeding technique. An N-terminal fragment of human SHARPIN was recombinantly expressed in Escherichia coli, purified and crystallized. Crystals suitable for X-ray diffraction were obtained by a one-step optimization of seed dilution and protein concentration using a two-dimensional grid screen. The crystals belonged to the primitive tetragonal space group P4 3 2 1 2, with unit-cell parameters a = b = 61.55, c = 222.81 Å. Complete data sets were collected from native and selenomethionine-substituted protein crystals at 100 K to 2.6 and 2.0 Å resolution, respectively

  18. The effect of aging on mitochondrial proteins in germinating soybean embryonic axes

    International Nuclear Information System (INIS)

    Furman, K.C.

    1988-01-01

    Aging-induced deterioration is a major problem associated with seed storage. Impairment of mitochondrial function is one of the first effects of aging. The composition and synthesis of nuclear and mito-coded mitochondrial proteins from soybean (Glycine max. L. Merr.) embryonic axes were studied to elucidate the cause of impaired respiratory development during germination of aged seeds. Axes excised from high vigor (HV) seeds and aged or low vigor (LV) seeds were protected from imbibition injury and germinated for various times, or excised from developing seeds, and then radiolabeled for one hour in [ 35 S]methionine. Mitochondria were then isolated and total mitochondrial protein was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), followed by quantitative staining and fluorography of labeled polypeptides. Alternatively, an original two-dimensional native-to-denaturing gel electrophoretic technique was used to analyze native protein associations and to purify a 23 kD polypeptide

  19. Application of Tandem Two-Dimensional Mass Spectrometry for Top-Down Deep Sequencing of Calmodulin.

    Science.gov (United States)

    Floris, Federico; Chiron, Lionel; Lynch, Alice M; Barrow, Mark P; Delsuc, Marc-André; O'Connor, Peter B

    2018-06-04

    Two-dimensional mass spectrometry (2DMS) involves simultaneous acquisition of the fragmentation patterns of all the analytes in a mixture by correlating their precursor and fragment ions by modulating precursor ions systematically through a fragmentation zone. Tandem two-dimensional mass spectrometry (MS/2DMS) unites the ultra-high accuracy of Fourier transform ion cyclotron resonance (FT-ICR) MS/MS and the simultaneous data-independent fragmentation of 2DMS to achieve extensive inter-residue fragmentation of entire proteins. 2DMS was recently developed for top-down proteomics (TDP), and applied to the analysis of calmodulin (CaM), reporting a cleavage coverage of about ~23% using infrared multiphoton dissociation (IRMPD) as fragmentation technique. The goal of this work is to expand the utility of top-down protein analysis using MS/2DMS in order to extend the cleavage coverage in top-down proteomics further into the interior regions of the protein. In this case, using MS/2DMS, the cleavage coverage of CaM increased from ~23% to ~42%. Graphical Abstract Two-dimensional mass spectrometry, when applied to primary fragment ions from the source, allows deep-sequencing of the protein calmodulin.

  20. Structures of larger proteins in solution: Three- and four-dimensional heteronuclear NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gronenborn, A.M.; Clore, G.M. [National Institutes of Health, Bethesda, MD (United States)

    1994-12-01

    Complete understanding of a protein`s function and mechanism of action can only be achieved with a knowledge of its three-dimensional structure at atomic resolution. At present, there are two methods available for determining such structures. The first method, which has been established for many years, is x-ray diffraction of protein single crystals. The second method has blossomed only in the last 5 years and is based on the application of nuclear magnetic resonance (NMR) spectroscopy to proteins in solution. This review paper describes three- and four-dimensional NMR methods applied to protein structure determination and was adapted from Clore and Gronenborn. The review focuses on the underlying principals and practice of multidimensional NMR and the structural information obtained.

  1. Electrophoretic and zymographic techniques for production monitoring of two lipase forms from Candida antarctica DSM 70725

    Directory of Open Access Journals (Sweden)

    Dimitrijević Aleksandra S.

    2012-01-01

    Full Text Available Yeast Candida antarctica produces two lipase forms, which are widely used as catalysts in variety of organic reactions, many of which are applied on a large scale. In this work, production of two forms of lipase from C. antarctica DSM 70725 (CAL A and CAL B was monitored during seven days of cultivation in the optimal medium using different electrophoretic and zymographic techniques. According to electrophoresis after silver staining, C. antarctica lipase A (molecular mass 45 kDa was produced starting from the second day of cultivation. C. antarctica lipase B (CAL B was also produced starting from the second day, but protein was present in the fermentation broth predominantly as dimer (molecular weight 66 kDa, while presence of monomeric form of CAL B (molecular weight of 33 kDa was observed starting from the fourth day of cultivation. Both types of zymograms (based on hydrolysis and synthesis reactions were used for detection of lipase activity in the fermentation broth. C. antarctica lipase A showed activity only in hydrolytic zymogram, when α-naphtyl butyrate was used as substrate. In the same zymogram, with α-naphtyl acetate as substrate no CAL A activity was detected. Similarly, CAL A showed no activity in synthesis based zymograms towards oleic acid and octanol as substrates, indicating that CAL A is not active towards very short or long-chain substrates. As opposite of CAL A, both monomeric and dimeric form of CAL B were detected in the all zymograms, suggesting that CAL B is active towards wide range of substrates, regardless to the chain length. Thus, zymogram based on hydrolysis of α-naphtyl butyrate represents a simple method for monitoring the production of two forms of lipase from C. antarctica, that greatly differ in their characteristics.

  2. Human cellular protein patterns and their link to genome DNA sequence data: usefulness of two-dimensional gel electrophoresis and microsequencing

    DEFF Research Database (Denmark)

    Celis, J E; Rasmussen, H H; Leffers, H

    1991-01-01

    a global approach to the study of the cell. Using the integrated approach offered by 2-dimensional gel protein databases it is now possible to reveal phenotype specific protein (or proteins), to microsequence them, to search for homology with previously identified proteins, to clone the cDNAs, to assign...

  3. Association of electrophoretic karyotype of Candida stellatoidea with virulence for mice

    International Nuclear Information System (INIS)

    Kwon-Chung, K.J.; Wickes, B.L.; Merz, W.G.

    1988-01-01

    Seven isolates of Candida stellatoidea were studied for their electrophoretic karyotype, virulence for mice, sensitivity to UV radiation, growth rate in vitro, reaction on cycloheximide-indicator medium, and proteinase activity. The isolates exhibited one of two distinct electrophoretic karyotypes as determined by orthogonal field alternating gel electrophoresis (OFAGE). Four isolates, including the type culture of C. stellatoidea, belonged to electrophoretic karyotype type I by OFAGE, showing eight to nine bands of which at least two bands were less than 1,000 kilobases in size as estimated by comparison with the DNA bands of Saccharomyces cerevisiae. These isolates failed to produce fatal infection in mice within 20 days when 5 X 10(5) cells were injected intravenously. The yeasts were cleared from the kidneys of two of three mice tested by day 30. Type I showed proteinase activity on bovine serum albumin agar at pH 3.8 and produced a negative reaction on cycloheximide-bromcresol green medium within 48 h. The three grouped in type II by OFAGE showed banding patterns similar to those of a well-characterized isolate of Candida albicans. The isolates of type II had an electrophoretic karyotype of six to seven bands approximately 1,200 kilobases or greater in size. All three type II isolates were highly virulent for mice, producing fatality curves similar to those of a previously studied C. albicans isolate. From 80 to 90% of the mice injected with 5 X 10(5) cells intravenously died within 20 days. The type II isolates produced a positive reaction on cycloheximide-bromcresol green agar and showed no proteinase activity on bovine serum albumin agar at the low pH. In addition, the type II isolates grew faster and were significantly more resistant to UV irradiation than the type I isolates

  4. Sample preparation guidelines for two-dimensional electrophoresis.

    Science.gov (United States)

    Posch, Anton

    2014-12-01

    Sample preparation is one of the key technologies for successful two-dimensional electrophoresis (2DE). Due to the great diversity of protein sample types and sources, no single sample preparation method works with all proteins; for any sample the optimum procedure must be determined empirically. This review is meant to provide a broad overview of the most important principles in sample preparation in order to avoid a multitude of possible pitfalls. Sample preparation protocols from the expert in the field were screened and evaluated. On the basis of these protocols and my own comprehensive practical experience important guidelines are given in this review. The presented guidelines will facilitate straightforward protocol development for researchers new to gel-based proteomics. In addition the available choices are rationalized in order to successfully prepare a protein sample for 2DE separations. The strategies described here are not limited to 2DE and can also be applied to other protein separation techniques.

  5. Electrophoretic variation in low molecular weight lens crystallins from inbred strains of rats.

    Science.gov (United States)

    Donner, M E; Skow, L C; Kunz, H W; Gill, T J

    1985-10-01

    Analysis of rat lens soluble proteins by analytical isoelectric focusing detected two inherited electrophoretic differences in low molecular weight (LM) crystallins from inbred strains of rats (Rattus norvegicus). The polymorphic lens crystallins were shown to be similar to a genetically variant LM crystallin, LEN-1, previously described in mice (Mus musculus) and encoded on chromosome 1, at a locus linked to Pep-3 (dipeptidase). Linkage analysis demonstrated that the rat crystallin locus was loosely linked to Pep-3 at a recombination distance of 38 +/- 4.5 U. These data suggest the conservation of a large chromosomal region during the evolution of Rodentia and support the hypothesis that the gamma-crystallins are evolving more rapidly than alpha- or beta-crystallins.

  6. Specific proteins synthesized during the viral lytic cycle in vaccinia virus-infected HeLa cells: analysis by high-resolution, two-dimensional gel electrophoresis

    International Nuclear Information System (INIS)

    Carrasco, L.; Bravo, R.

    1986-01-01

    The proteins synthesized in vaccinia-infected HeLa cells have been analyzed at different times after infection by using two-dimensional gel electrophoresis. Vaccinia-infected cells present up to 198 polypeptides (138 acidic, isoelectric focusing; 60 basic, nonequilibrium pH gradient electrophoresis) not detected in control cells. Cells infected in the presence of cycloheximide show 81 additional polypeptides after cycloheximide removal, resulting in a total estimate of 279 proteins induced after vaccinia infection. The glycoproteins made at various time postinfection were also analyzed. At least 13 proteins labeled with [ 3 H]glucosamine were detected in vaccinia-infected HeLa cells

  7. Radiation-induced Changes in the Electrophoretic Profile of Serum Albumin

    Directory of Open Access Journals (Sweden)

    Celso Vieira Lima

    2018-01-01

    Full Text Available ABSTRACT Albumin protein profiles were investigated in electrophoresis system in relation to the whole body exposition to the radiation. Two groups of rats Wistar were set up as the control (CG and the irradiated one (IG. The IG was exposed to Co-60 at a dose of 5 Gy. After a 72-hour exposition, 300 μL of blood was collected in the inferior vena cava, renal, jugular, hepatic, and pulmonary veins and the serum separated. The albumin protein was identified by vertical electrophoresis in acrylamide Commassi blue or silver stained. The calibration procedure was applied to albumin samples with well-known concentrations. The mathematical correlation was developed involving electrophoretic parameters of band intensities and sizes from gel representation, providing values of protein concentrations in comparison with standard bands with known concentrations. There were significant differences in the physiological concentrations in the jugular and pulmonary sites in relation to renal and cava regional sites. Significant differences induced by radiation in serum albumin concentration were also found in hepatic and jugular sites. Alteration of albumin concentration was found as a nearly effect from whole body irradiation. This phenomenon points out to alterations in cell metabolism in the liver justified by a possible indication of proteomics damage from radiation.

  8. Optimized sample preparation for two-dimensional gel electrophoresis of soluble proteins from chicken bursa of Fabricius

    Directory of Open Access Journals (Sweden)

    Zheng Xiaojuan

    2009-10-01

    Full Text Available Abstract Background Two-dimensional gel electrophoresis (2-DE is a powerful method to study protein expression and function in living organisms and diseases. This technique, however, has not been applied to avian bursa of Fabricius (BF, a central immune organ. Here, optimized 2-DE sample preparation methodologies were constructed for the chicken BF tissue. Using the optimized protocol, we performed further 2-DE analysis on a soluble protein extract from the BF of chickens infected with virulent avibirnavirus. To demonstrate the quality of the extracted proteins, several differentially expressed protein spots selected were cut from 2-DE gels and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS. Results An extraction buffer containing 7 M urea, 2 M thiourea, 2% (w/v 3-[(3-cholamidopropyl-dimethylammonio]-1-propanesulfonate (CHAPS, 50 mM dithiothreitol (DTT, 0.2% Bio-Lyte 3/10, 1 mM phenylmethylsulfonyl fluoride (PMSF, 20 U/ml Deoxyribonuclease I (DNase I, and 0.25 mg/ml Ribonuclease A (RNase A, combined with sonication and vortex, yielded the best 2-DE data. Relative to non-frozen immobilized pH gradient (IPG strips, frozen IPG strips did not result in significant changes in the 2-DE patterns after isoelectric focusing (IEF. When the optimized protocol was used to analyze the spleen and thymus, as well as avibirnavirus-infected bursa, high quality 2-DE protein expression profiles were obtained. 2-DE maps of BF of chickens infected with virulent avibirnavirus were visibly different and many differentially expressed proteins were found. Conclusion These results showed that method C, in concert extraction buffer IV, was the most favorable for preparing samples for IEF and subsequent protein separation and yielded the best quality 2-DE patterns. The optimized protocol is a useful sample preparation method for comparative proteomics analysis of chicken BF tissues.

  9. Two-dimensional gel electrophoresis pattern (pH 6-11) and identification of water-soluble barley seed and malt proteins by mass spectrometry

    DEFF Research Database (Denmark)

    Bak-Jensen, K.S.; Laugesen, S.; Roepstorff, P.

    2004-01-01

    A protocol was established for two-dimensional gel electrophoresis (2-DE) of barley seed and malt proteins in the pH range of 6-11. Proteins extracted from flour in a low-salt buffer were focused after cup-loading onto IPG strips. Successful separation in the second dimension was achieved using...... gradient gels in a horizontal SDS-PAGE system. Silver staining of gels visualized around 380 (seed) and 500 (malt) spots. Thirty-seven different proteins from seeds were identified in 60 spots, among these 46 were visualized also in the malt 2-D pattern. Proteins were identified by peptide mass...... in defence against pathogens (21 spots), 4 in storage, folding, and synthesis of proteins, and in nitrogen metabolism (5 spots), 6 in carbohydrate metabolism (11 spots), and 4 in stress and detoxification (9 spots). Six proteins (7 spots) were not grouped in these categories, and 3 were not ascribed...

  10. Two-Dimensional Electrophoresis Study of Lactobacillus delbrueckii subsp. bulgaricus Thermotolerance

    OpenAIRE

    Gouesbet, Gwenola; Jan, Gwenael; Boyaval, Patrick

    2002-01-01

    The response of Lactobacillus delbrueckii subsp. bulgaricus cells to heat stress was studied by use of a chemically defined medium. Two-dimensional electrophoresis (2-DE) analysis was used to correlate the kinetics of heat shock protein (HSP) induction with cell recovery from heat injury. We demonstrated that enhanced viability, observed after 10 min at 65°C, resulted from the overexpression of HSP and from mechanisms not linked to protein synthesis. In order to analyze the thermoadaptation m...

  11. The human keratinocyte two-dimensional protein database (update 1994): towards an integrated approach to the study of cell proliferation, differentiation and skin diseases

    DEFF Research Database (Denmark)

    Celis, J E; Rasmussen, H H; Olsen, E

    1994-01-01

    The master two-dimensional (2-D) gel database of human keratinocytes currently lists 3087 cellular proteins (2168 isoelectric focusing, IEF; and 919 none-quilibrium pH gradient electrophoresis, NEPHGE), many of which correspond to posttranslational modifications, 890 polypeptides have been...... in the database. We also report a database of proteins recovered from the medium of noncultured, unfractionated keratinocytes. This database lists 398 polypeptides (309 IEF; 89 NEPHGE) of which 76 have been identified. The aim of the comprehensive databases is to gather, through a systematic study...

  12. Proton transport in a membrane protein channel: two-dimensional infrared spectrum modeling.

    NARCIS (Netherlands)

    Liang, C.; Knoester, J.; Jansen, T.L.Th.A.

    2012-01-01

    We model the two-dimensional infrared (2DIR) spectrum of a proton channel to investigate its applicability as a spectroscopy tool to study the proton transport process in biological systems. Proton transport processes in proton channels are involved in numerous fundamental biochemical reactions.

  13. Interpretive Reporting of Protein Electrophoresis Data by Microcomputer

    Science.gov (United States)

    Talamo, Thomas S.; Losos, Frank J.; Kessler, G. Frederick

    1982-01-01

    A microcomputer based system for interpretive reporting of protein electrophoretic data has been developed. Data for serum, urine and cerebrospinal fluid protein electrophoreses as well as immunoelectrophoresis can be entered. Patient demographic information is entered through the keyboard followed by manual entry of total and fractionated protein levels obtained after densitometer scanning of the electrophoretic strip. The patterns are then coded, interpreted, and final reports generated. In most cases interpretation time is less than one second. Misinterpretation by computer is uncommon and can be corrected by edit functions within the system. These discrepancies between computer and pathologist interpretation are automatically stored in a data file for later review and possible program modification. Any or all previous tests on a patient may be reviewed with graphic display of the electrophoretic pattern. The system has been in use for several months and is presently well accepted by both laboratory and clinical staff. It also allows rapid storage, retrieval and analysis of protein electrophoretic datab.

  14. Equivalence of two-dimensional gravities

    International Nuclear Information System (INIS)

    Mohammedi, N.

    1990-01-01

    The authors find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL(2,R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2 + 1 dimensional gravity. The authors present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given

  15. Two-dimensional metamaterial optics

    International Nuclear Information System (INIS)

    Smolyaninov, I I

    2010-01-01

    While three-dimensional photonic metamaterials are difficult to fabricate, many new concepts and ideas in the metamaterial optics can be realized in two spatial dimensions using planar optics of surface plasmon polaritons. In this paper we review recent progress in this direction. Two-dimensional photonic crystals, hyperbolic metamaterials, and plasmonic focusing devices are demonstrated and used in novel microscopy and waveguiding schemes

  16. Two-Dimensional Spectroscopy Is Being Used to Address Core Scientific Questions in Biology and Materials Science.

    Science.gov (United States)

    Petti, Megan K; Lomont, Justin P; Maj, Michał; Zanni, Martin T

    2018-02-15

    Two-dimensional spectroscopy is a powerful tool for extracting structural and dynamic information from a wide range of chemical systems. We provide a brief overview of the ways in which two-dimensional visible and infrared spectroscopies are being applied to elucidate fundamental details of important processes in biological and materials science. The topics covered include amyloid proteins, photosynthetic complexes, ion channels, photovoltaics, batteries, as well as a variety of promising new methods in two-dimensional spectroscopy.

  17. Electrophoretic deposition of sol-gel-derived ceramic coatings

    International Nuclear Information System (INIS)

    Zhang, Y.; Crooks, R.M.

    1992-01-01

    In this paper the physical, optical, and chemical characteristics of electrophoretically and dip-coated sol-gel ceramic films are compared. The results indicate that electrophoresis may allow a higher level of control over the chemistry and structure of ceramic coatings than dip-coating techniques. For example, controlled-thickness sol-gel coatings can be prepared by adjusting the deposition time or voltage. Additionally, electrophoretic coatings can be prepared in a four-component alumino-borosilicate sol display interesting optical characteristics. For example, the ellipsometrically-measured refractive indices of electrophoretic coatings are higher than the refractive indices of dip-coated films cast from identical sols, and they are also higher than any of the individual sol components. This result suggests that there are physical and/or chemical differences between films prepared by dip-coating and electrophoresis

  18. Fish proteins as targets of ferrous-catalyzed oxidation: identification of protein carbonyls by fluorescent labeling on two-dimensional gels and MALDI-TOF/TOF mass spectrometry.

    Science.gov (United States)

    Pazos, Manuel; da Rocha, Angela Pereira; Roepstorff, Peter; Rogowska-Wrzesinska, Adelina

    2011-07-27

    Protein oxidation in fish meat is considered to affect negatively the muscle texture. An important source of free radicals taking part in this process is Fenton's reaction dependent on ferrous ions present in the tissue. The aim of this study was to investigate the susceptibility of cod muscle proteins in sarcoplasmic and myofibril fractions to in vitro metal-catalyzed oxidation and to point out protein candidates that might play a major role in the deterioration of fish quality. Extracted control proteins and proteins subjected to free radicals generated by Fe(II)/ascorbate mixture were labeled with fluorescein-5-thiosemicarbazide (FTSC) to tag carbonyl groups and separated by two-dimensional gel electrophoresis. Consecutive visualization of protein carbonyl levels by capturing the FTSC signal and total protein levels by capturing the SyproRuby staining signal allowed us to quantify the relative change in protein carbonyl levels corrected for changes in protein content. Proteins were identified using MALDI-TOF/TOF mass spectrometry and homology-based searches. The results show that freshly extracted cod muscle proteins exhibit a detectable carbonylation background and that the incubation with Fe(II)/ascorbate triggers a further oxidation of both sarcoplasmic and myofibril proteins. Different proteins exhibited various degrees of sensitivity to oxidation processes. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), nucleoside diphosphate kinase B (NDK), triosephosphate isomerase, phosphoglycerate mutase, lactate dehydrogenase, creatine kinase, and enolase were the sarcoplasmic proteins most vulnerable to ferrous-catalyzed oxidation. Moreover, NDK, phosphoglycerate mutase, and GAPDH were identified in several spots differing by their pI, and those forms showed different susceptibilities to metal-catalyzed oxidation, indicating that post-translational modifications may change the resistance of proteins to oxidative damage. The Fe(II)/ascorbate treatment significantly

  19. Identification of differentially expressed proteins between human esophageal immortalized and carcinomatous cell lines by two-dimensional electrophoresis and MALDI-TOF-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Xing-Dong Xiong; Li-Yan Xu; Zhong-Ying Shen; Wei-Jia Cai; Jian-Min Luo; Ya-Li Han; En-Min Li

    2002-01-01

    AIM: To identify the differentially expressed proteins between the human immortalized esophageal epithelial cell line (SHEE) and the malignant transformed esophageal carcinoma cell line (SHEEC), and to explore new ways for studying esophageal carcinoma associated genes. METHODS: SHEE and SHEEC cell lines were used to separate differentially expressed proteins by two-dimensional electrophoresis/The silver-stained 2-D gels was scanned with EDAS290 digital camera system and analyzed with the PDQuest 6.2 Software. Six spots in which the differentially expressed protein was more obvious were selected and analyzed with matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS).RESULTS: There were 107±4.58 and 115±9.91 protein spots observed in SHEE and SHEEC respectively, and the majority of these spots between the two cell lines matched each other (r=-0.772), only a few were expressed differentially. After analyzed by MALDI-TOF-MS and database search for the six differentially expressed proteins, One new protein as well as other five sequence-known proteins including RNPEP-like protein, human rRNA gene upstream sequence binding transcription factor, uracil DNA glycosylase,Annexin A2 and p300/CBP-associated factor were preliminarily identified.CONCLUSION: These differentially expressed proteins might play an importance role during malignant transformation of SHEEC from SHEE. The identification of these proteins may serve as a new way for studying esophageal carcinoma associated genes.

  20. Comparison of liver mitochondrial proteins derived from newborn cloned calves and from cloned adult cattle by two-dimensional differential gel electrophoresis.

    Science.gov (United States)

    Takeda, Kumiko; Tasai, Mariko; Akagi, Satoshi; Watanabe, Shinya; Oe, Mika; Chikuni, Koichi; Ohnishi-Kameyama, Mayumi; Hanada, Hirofumi; Nakamura, Yoshiaki; Tagami, Takahiro; Nirasawa, Keijiro

    2011-04-01

    Aberrant reprogramming of donor somatic cell nuclei may result in many severe problems in animal cloning. The inability to establish functional interactions between donor nucleus and recipient mitochondria is also likely responsible for such a developmental deficiency. However, detailed knowledge of protein expression during somatic cell nuclear transfer (SCNT) in cattle is lacking. In the present study, variations in mitochondrial protein levels between SCNT-derived and control cattle, and from calves derived by artificial insemination were investigated. Mitochondrial fractions were prepared from frozen liver samples and subjected to two-dimensional (2-D) fluorescence differential gel electrophoresis (DIGE) using CyDye™ dyes. Protein expression changes were confirmed with a volume ratio greater than 2.0 (P result implicates mitochondrial-related gene expression in early developmental loss of SCNT embryos. Comparative proteomic analysis represents an important tool for further studies on SCNT animals. Copyright © 2011 Wiley-Liss, Inc.

  1. On the two-dimensional Saigo-Maeda fractional calculus asociated with two-dimensional Aleph TRANSFORM

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2013-11-01

    Full Text Available This paper deals with the study of two-dimensional Saigo-Maeda operators of Weyl type associated with Aleph function defined in this paper. Two theorems on these defined operators are established. Some interesting results associated with the H-functions and generalized Mittag-Leffler functions are deduced from the derived results. One dimensional analog of the derived results is also obtained.

  2. Development of the resolution theory for electrophoretic exclusion.

    Science.gov (United States)

    Kenyon, Stacy M; Keebaugh, Michael W; Hayes, Mark A

    2014-09-01

    Electrophoretic exclusion, a technique that differentiates species in bulk solution near a channel entrance, has been demonstrated on benchtop and microdevice designs. In these systems, separation occurs when the electrophoretic velocity of one species is greater than the opposing hydrodynamic flow, while the velocity of the other species is less than that flow. Although exclusion has been demonstrated in multiple systems for a range of analytes, a theoretical assessment of resolution has not been addressed. To compare the results of these calculations to traditional techniques, the performance is expressed in terms of smallest difference in electrophoretic mobilities that can be completely separated (R = 1.5). The calculations indicate that closest resolvable species (Δμmin ) differ by approximately 10(-13) m(2) /Vs and peak capacity (nc ) is 1000. Published experimental data were compared to these calculated results. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Assessment of Carbon- and Metal-Based Nanoparticle DNA Damage with Microfluidic Electrophoretic Separation Technology.

    Science.gov (United States)

    Schrand, Amanda M; Powell, Thomas; Robertson, Tiffany; Hussain, Saber M

    2015-02-01

    In this study, we examined the feasibility of extracting DNA from whole cell lysates exposed to nanoparticles using two different methodologies for evaluation of fragmentation with microfluidic electrophoretic separation. Human lung macrophages were exposed to five different carbon- and metal-based nanoparticles at two different time points (2 h, 24 h) and two different doses (5 µg/ml, 100 µg/ml). The primary difference in the banding patterns after 2 h of nanoparticle exposure is more DNA fragmentation at the higher NP concentration when examining cells exposed to nanoparticles of the same composition. However, higher doses of carbon and silver nanoparticles at both short and long dosing periods can contribute to erroneous or incomplete data with this technique. Also comparing DNA isolation methodologies, we recommend the centrifugation extraction technique, which provides more consistent banding patterns in the control samples compared to the spooling technique. Here we demonstrate that multi-walled carbon nanotubes, 15 nm silver nanoparticles and the positive control cadmium oxide cause similar DNA fragmentation at the short time point of 2 h with the centrifugation extraction technique. Therefore, the results of these studies contribute to elucidating the relationship between nanoparticle physicochemical properties and DNA fragmentation results while providing the pros and cons of altering the DNA isolation methodology. Overall, this technique provides a high throughput way to analyze subcellular alterations in DNA profiles of cells exposed to nanomaterials to aid in understanding the consequences of exposure and mechanistic effects. Future studies in microfluidic electrophoretic separation technologies should be investigated to determine the utility of protein or other assays applicable to cellular systems exposed to nanoparticles.

  4. New Approach for Segmentation and Quantification of Two-Dimensional Gel Electrophoresis Images

    DEFF Research Database (Denmark)

    Anjo, Antonio dos; Laurell Blom Møller, Anders; Ersbøll, Bjarne Kjær

    2011-01-01

    Motivation: Detection of protein spots in two-dimensional gel electrophoresis images (2-DE) is a very complex task and current approaches addressing this problem still suffer from significant shortcomings. When quantifying a spot, most of the current software applications include a lot of backgro...

  5. New apparatus for direct counting of β particles from two-dimensional gels and an application to changes in protein synthesis due to cell density

    International Nuclear Information System (INIS)

    Anderson, H.L.; Puck, T.T.; Shera, E.B.

    1987-07-01

    A new method is described for scanning two-dimensional gels by the direct counting of β particles instead of autoradiography. The methodology is described; results are compared with autoradiographic results; and data are presented demonstrating changed patterns of protein synthesis accompanying changes in cell density. The method is rapid and permits identification of differences in protein abundance of approximately 10% for a substantial fraction of the more prominent proteins. A modulation effect of more than 5 standard deviations, accompanying contact inhibition of cell growth, is shown to occur for an appreciable number of these proteins. The method promises to be applicable to a variety of biochemical and genetic experiments designed to delineate changes in protein synthesis accompanying changes in genome, molecular environment, history, and state of differentiation of the cell populations studied. 13 refs., 8 figs., 4 tabs

  6. A plasmid containing the human metallothionein II gene can function as an antibody-assisted electrophoretic biosensor for heavy metals.

    Science.gov (United States)

    Wooten, Dennis C; Starr, Clarise R; Lyon, Wanda J

    2016-01-01

    Different forms of heavy metals affect biochemical systems in characteristic ways that cannot be detected with typical metal analysis methods like atomic absorption spectrometry. Further, using living systems to analyze interaction of heavy metals with biochemical systems can be laborious and unreliable. To generate a reliable easy-to-use biologically-based biosensor system, the entire human metallothionein-II (MT-II) gene was incorporated into a plasmid (pUC57-MT) easily replicated in Escherichia coli. In this system, a commercial polyclonal antibody raised against human metal-responsive transcription factor-1 protein (MTF-1 protein) could modify the electrophoretic migration patterns (i.e. cause specific decreases in agarose gel electrophoretic mobility) of the plasmid in the presence or absence of heavy metals other than zinc (Zn). In the study here, heavy metals, MTF-1 protein, and polyclonal anti-MTF-1 antibody were used to assess pUC57-MT plasmid antibody-assisted electrophoretic mobility. Anti-MTF-1 antibody bound both MTF-1 protein and pUC57-MT plasmid in a non-competitive fashion such that it could be used to differentiate specific heavy metal binding. The results showed that antibody-inhibited plasmid migration was heavy metal level-dependent. Zinc caused a unique mobility shift pattern opposite to that of other metals tested, i.e. Zn blocked the antibody ability to inhibit plasmid migration, despite a greatly increased affinity for DNA by the antibody when Zn was present. The Zn effect was reversed/modified by adding MTF-1 protein. Additionally, antibody inhibition of plasmid mobility was resistant to heat pre-treatment and trypsinization, indicating absence of residual DNA extraction-resistant bacterial DNA binding proteins. DNA binding by anti-DNA antibodies may be commonly enhanced by xenobiotic heavy metals and elevated levels of Zn, thus making them potentially effective tools for assessment of heavy metal bioavailability in aqueous solutions and

  7. Two-dimensional nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Bax, A.; Lerner, L.

    1986-01-01

    Great spectral simplification can be obtained by spreading the conventional one-dimensional nuclear magnetic resonance (NMR) spectrum in two independent frequency dimensions. This so-called two-dimensional NMR spectroscopy removes spectral overlap, facilitates spectral assignment, and provides a wealth of additional information. For example, conformational information related to interproton distances is available from resonance intensities in certain types of two-dimensional experiments. Another method generates 1 H NMR spectra of a preselected fragment of the molecule, suppressing resonances from other regions and greatly simplifying spectral appearance. Two-dimensional NMR spectroscopy can also be applied to the study of 13 C and 15 N, not only providing valuable connectivity information but also improving sensitivity of 13 C and 15 N detection by up to two orders of magnitude. 45 references, 10 figures

  8. Identification of proteins of human colorectal carcinoma cell line SW480 by two-dimensional electrophoresis and MALDI-TOF mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Ying-Tao Zhang; Yi-Ping Geng; Le Zhou; Bao-Chang Lai; Lv-Sheng Si; Yi-Li Wang

    2005-01-01

    AIM: To conduct the proteomic analysis of human colorectal carcinoma cell line, SW480 by using two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption /ionization-time of flight mass spectrometry (MALDITOFMS).METHODS: The total proteins of human colorectal carcinoma cell line, SW480 were separated with 2-DE by using immobilized pH gradient strips and visualized by staining with silver nitrate. The gel images were acquired by scanner and 2-DE analysis software, Image Master 2D Elite. Nineteen distinct protein spots were excised from gel randomly and digested in gel by TPCK-trypsin. Mass analysis ofthe tryptic digest peptides mixture was performed by using MALDI-TOF MS. Peptide mass fingerprints (PMFs) obtained by the MALDI-TOF analysis were used to search NCBI,SWISS-PROT and MSDB databases by using Mascot software.RESULTS: PMF maps of all spots were obtained by MALDI-TOF MS and thirteen proteins were preliminarily identified.CONCLUSION: The methods of analysis and identification of protein spots of tumor cells in 2-DE gel with silver staining by MALDI-TOF MS derived PMF have been established.Protein expression profile of SW480 has been obtained.It is demonstrated that a combination of proteomics and cell culture is a useful approach to comprehend the process of colon carcinogenesis.

  9. Enhanced resolution of DNA restriction fragments: A procedure by two-dimensional electrophoresis and double-labeling

    International Nuclear Information System (INIS)

    Yi, M.; Au, L.C.; Ichikawa, N.; Ts'o, P.O.

    1990-01-01

    A probe-free method was developed to detect DNA rearrangement in bacteria based on the electrophoretic separation of twice-digested restriction fragments of genomic DNA into a two-dimensional (2-D) pattern. The first restriction enzyme digestion was done in solution, followed by electrophoresis of the restriction fragments in one dimension. A second restriction enzyme digestion was carried out in situ in the gel, followed by electrophoresis in a second dimension perpendicular to the first electrophoresis. The 2-D pattern provides for the resolution of 300-400 spots, which are defined and indexed by an x,y coordinate system with size markers. This approach has greatly increased the resolution power over conventional one-dimensional (1-D) electrophoresis. To study DNA rearrangement, a 2-D pattern from a test strain was compared with the 2-D pattern from a reference strain. After the first digestion, genomic DNA fragments from the test strain were labeled with 35S, while those from the reference strain were labeled with 32P. This was done to utilize the difference in the energy emission of 35S and 32P isotopes for autoradiography when two x-ray films were exposed simultaneously on top of the gel after the 2-D electrophoresis. The irradiation from the decay of 35S exposed only the lower film, whereas the irradiation from the decay of 32P exposed both the lower and upper films. Different DNA fragments existed in the test DNA compared with the reference DNA can be identified unambiguously by the differential two 2-D patterns produced on two films upon exposure to the 35S and 32P fragments in the same gel. An appropriate photographic procedure further simplified the process, allowing only the difference in DNA fragments between these two patterns to be shown in the map

  10. On some classes of two-dimensional local models in discrete two-dimensional monatomic FPU lattice with cubic and quartic potential

    International Nuclear Information System (INIS)

    Quan, Xu; Qiang, Tian

    2009-01-01

    This paper discusses the two-dimensional discrete monatomic Fermi–Pasta–Ulam lattice, by using the method of multiple-scale and the quasi-discreteness approach. By taking into account the interaction between the atoms in the lattice and their nearest neighbours, it obtains some classes of two-dimensional local models as follows: two-dimensional bright and dark discrete soliton trains, two-dimensional bright and dark line discrete breathers, and two-dimensional bright and dark discrete breather. (condensed matter: structure, thermal and mechanical properties)

  11. [Establishment of two-dimensional differential gel electrophoresis using cerebrospinal fluid from neurocysticercosis patients].

    Science.gov (United States)

    Li, Jing-Yi; Tian, Xiao-Jun; Huang, Yong; Yang, Yan-Jun; Ma, Qiao-Rong; Xue, Yan-Ping

    2008-06-30

    To establish the method of two-dimensional differential gel electrophoresis and obtain high resolution 2D images from cerebrospinal fluid (CSF) of patients with neurocysticercosis. CSF samples were collected from four patients diagnosed as neurocysticercosis clinically and by ELISA, computed tomography (CT) or magnetic resonance imaging (MRI), and from four healthy subjects without neurological disorders. The CSF samples were precipitated with cold acetone, then pooled by equal amount as patients and controls. The internal standard comprised equal amounts of proteins extracted from both groups. Internal standard, and proteins from the two groups were labeled prior to electrophoresis with spectrally resolvable fluorescent dyes, cyanein dye2 (Cy2), Cy3 and Cy5. Sodium dodecylsulfonate polyacrylamide gel chromatography (SDS-PAGE) and two-dimensional differential in-gel electrophoresis (2-D DIGE) of labeled samples were then run. The differential expressed proteins showed in the images of SDS-PAGE and 2-D DIGE gels scanned with 488 nm, 532 nm and 633 nm wavelength laser were analyzed by ImageQuant and DeCyde 5.0 respectively. Spot detection and quantification was performed for the differential in-gel analysis (DIA) module of DeCyder. Biological variation analysis (BVA) module of DeCyder was matched gel 1 and gel 2 images to provide data on differential protein expression levels between the two groups. The ImageQuant result displayed that the CSF protein was compatible with the dye, and the difference of protein amount was revealed by the difference of fluorescence intensity. DIA indicated that there were 896 and 894 protein dots on gel 1 and gel 2 respectively, and 90% of them were matched each other. BVA showed that there were 55 protein spots with different expressional level between neurocysticercosis and control groups. Protein spots with two-fold increase or decrease were 47 and 8 respectively in neurocysticercosis patients compared with healthy controls. The

  12. Two-dimensional models

    International Nuclear Information System (INIS)

    Schroer, Bert; Freie Universitaet, Berlin

    2005-02-01

    It is not possible to compactly review the overwhelming literature on two-dimensional models in a meaningful way without a specific viewpoint; I have therefore tacitly added to the above title the words 'as theoretical laboratories for general quantum field theory'. I dedicate this contribution to the memory of J. A. Swieca with whom I have shared the passion of exploring 2-dimensional models for almost one decade. A shortened version of this article is intended as a contribution to the project 'Encyclopedia of mathematical physics' and comments, suggestions and critical remarks are welcome. (author)

  13. Exploration of beer proteome using OFFGEL prefractionation in combination with two-dimensional gel electrophoresis with narrow pH range gradients.

    Science.gov (United States)

    Konečná, Hana; Müller, Lukáš; Dosoudilová, Hana; Potěšil, David; Buršíková, Jana; Sedo, Ondrej; Márová, Ivana; Zdráhal, Zbyněk

    2012-03-14

    Two-dimensional gel electrophoresis in combination with mass spectrometry has already been applied successfully to study beer proteome. Due to the abundance of protein Z in beer samples, prefractionation techniques might help to improve beer proteome coverage. Proteins from four lager beers of different origins were separated by two-dimensional electrophoresis (2-DE) followed by tandem mass spectrometric analysis. Initially 52 proteins mostly from Hordeum vulgare (22 proteins) and Saccharomyces species (25 proteins) were identified. Preparative isoelectric focusing by OFFGEL Fractionator was applied prior to 2-DE to improve its resolution power. As a result of this combined approach, a total of 70 beer proteins from Hordeum vulgare (30 proteins), from Saccharomyces species (31 proteins), and from other sources (9 proteins) were identified. Of these, 37 proteins have not been previously reported in beer samples.

  14. Two-dimensional multifractal cross-correlation analysis

    International Nuclear Information System (INIS)

    Xi, Caiping; Zhang, Shuning; Xiong, Gang; Zhao, Huichang; Yang, Yonghong

    2017-01-01

    Highlights: • We study the mathematical models of 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Present the definition of the two-dimensional N 2 -partitioned multiplicative cascading process. • Do the comparative analysis of 2D-MC by 2D-MFXPF, 2D-MFXDFA and 2D-MFXDMA. • Provide a reference on the choice and parameter settings of these methods in practice. - Abstract: There are a number of situations in which several signals are simultaneously recorded in complex systems, which exhibit long-term power-law cross-correlations. This paper presents two-dimensional multifractal cross-correlation analysis based on the partition function (2D-MFXPF), two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) and two-dimensional multifractal cross-correlation analysis based on the detrended moving average analysis (2D-MFXDMA). We apply these methods to pairs of two-dimensional multiplicative cascades (2D-MC) to do a comparative study. Then, we apply the two-dimensional multifractal cross-correlation analysis based on the detrended fluctuation analysis (2D-MFXDFA) to real images and unveil intriguing multifractality in the cross correlations of the material structures. At last, we give the main conclusions and provide a valuable reference on how to choose the multifractal algorithms in the potential applications in the field of SAR image classification and detection.

  15. THE VALENCE OF CORPUSCULAR PROTEINS.

    Science.gov (United States)

    Gorin, M H; Mover, L S

    1942-07-20

    BY THE USE OF TWO EXTREME MODELS: a hydrated sphere and an unhydrated rod the valence (net charge) of corpuscular proteins can be successfully calculated from electric mobility data by the Debye-Hückel theory (modified to include the effect of the ions in the ion atmosphere) in conjunction with the electrophoretic theory of Henry. As pointed out by Abramson, this permits a comparison with values for the valence from titration data. Electrometric titration measurements of serum albumin B (Kekwick) have been determined at several ionic strengths. These results, together with the available data in the literature for serum albumin B, egg albumin, and beta-lactoglobulin have been used to compare values for the valence calculated from measurements of titration, electrophoresis, and membrane potentials. The results indicate that the usual interpretation of titration curves is open to serious question. By extrapolation of the titration data to zero ionic strength and protein concentration, there results an "intrinsic" net charge curve describing the binding of H(+) (OH(-)) ion alone. This curve agrees closely, in each case, with values of the valence calculated from mobility data (which in turn are in close accord with those estimated from membrane potential measurements). The experimental titration curves in the presence of appreciable quantities of ions and protein deviate widely from the ideal curve. It is suggested that, under these conditions, binding of undissociated acid (base) leads to erroneous values for the net charge. This binding would not affect the electrophoretic mobility. Values of the net charge obtained by the two extreme models from electrophoretic data are in agreement within 15 to 20 per cent. The agreement between the cylindrical model and the titration data is somewhat better in each case than with the sphere; i.e., this comparison enables a choice to be made between asymmetry and hydration in the interpretation of results from sedimentation and

  16. Two-dimensional beam profiles and one-dimensional projections

    Science.gov (United States)

    Findlay, D. J. S.; Jones, B.; Adams, D. J.

    2018-05-01

    One-dimensional projections of improved two-dimensional representations of transverse profiles of particle beams are proposed for fitting to data from harp-type monitors measuring beam profiles on particle accelerators. Composite distributions, with tails smoothly matched on to a central (inverted) parabola, are shown to give noticeably better fits than single gaussian and single parabolic distributions to data from harp-type beam profile monitors all along the proton beam transport lines to the two target stations on the ISIS Spallation Neutron Source. Some implications for inferring beam current densities on the beam axis are noted.

  17. Progress in two-dimensional polyacrylamide gel electrophoresis and application in radiation research

    International Nuclear Information System (INIS)

    Wang Zhidong; Chen Xiaohua

    2003-01-01

    Two-dimensional polyacrylamide gel electrophoresis is the key separation technique in proteomics research, which is designed by protein character: molecular weight and PI. Some progress has been made in disease mechanism detection, tumor indicator research and drug development. This technique also has some potential application in radiation research

  18. Three-dimensional electrodes for dye-sensitized solar cells: synthesis of indium-tin-oxide nanowire arrays and ITO/TiO2 core-shell nanowire arrays by electrophoretic deposition

    International Nuclear Information System (INIS)

    Wang, H-W; Ting, C-F; Hung, M-K; Chiou, C-H; Liu, Y-L; Liu Zongwen; Ratinac, Kyle R; Ringer, Simon P

    2009-01-01

    Dye-sensitized solar cells (DSSCs) show promise as a cheaper alternative to silicon-based photovoltaics for specialized applications, provided conversion efficiency can be maximized and production costs minimized. This study demonstrates that arrays of nanowires can be formed by wet-chemical methods for use as three-dimensional (3D) electrodes in DSSCs, thereby improving photoelectric conversion efficiency. Two approaches were employed to create the arrays of ITO (indium-tin-oxide) nanowires or arrays of ITO/TiO 2 core-shell nanowires; both methods were based on electrophoretic deposition (EPD) within a polycarbonate template. The 3D electrodes for solar cells were constructed by using a doctor-blade for coating TiO 2 layers onto the ITO or ITO/TiO 2 nanowire arrays. A photoelectric conversion efficiency as high as 4.3% was achieved in the DSSCs made from ITO nanowires; this performance was better than that of ITO/TiO 2 core-shell nanowires or pristine TiO 2 films. Cyclic voltammetry confirmed that the reaction current was significantly enhanced when a 3D ITO-nanowire electrode was used. Better separation of charge carriers and improved charge transport, due to the enlarged interfacial area, are thought to be the major advantages of using 3D nanowire electrodes for the optimization of DSSCs.

  19. FPGA Implementation of one-dimensional and two-dimensional cellular automata

    International Nuclear Information System (INIS)

    D'Antone, I.

    1999-01-01

    This report describes the hardware implementation of one-dimensional and two-dimensional cellular automata (CAs). After a general introduction to the cellular automata, we consider a one-dimensional CA used to implement pseudo-random techniques in built-in self test for VLSI. Due to the increase in digital ASIC complexity, testing is becoming one of the major costs in the VLSI production. The high electronics complexity, used in particle physics experiments, demands higher reliability than in the past time. General criterions are given to evaluate the feasibility of the circuit used for testing and some quantitative parameters are underlined to optimize the architecture of the cellular automaton. Furthermore, we propose a two-dimensional CA that performs a peak finding algorithm in a matrix of cells mapping a sub-region of a calorimeter. As in a two-dimensional filtering process, the peaks of the energy clusters are found in one evolution step. This CA belongs to Wolfram class II cellular automata. Some quantitative parameters are given to optimize the architecture of the cellular automaton implemented in a commercial field programmable gate array (FPGA)

  20. Diamond electrophoretic microchips-Joule heating effects

    International Nuclear Information System (INIS)

    Karczemska, Anna T.; Witkowski, Dariusz; Ralchenko, Victor; Bolshakov, Andrey; Sovyk, Dmitry; Lysko, Jan M.; Fijalkowski, Mateusz; Bodzenta, Jerzy; Hassard, John

    2011-01-01

    Microchip electrophoresis (MCE) has become a mature separation technique in the recent years. In the presented research, a polycrystalline diamond electrophoretic microchip was manufactured with a microwave plasma chemical vapour deposition (MPCVD) method. A replica technique (mould method) was used to manufacture microstructures in diamond. A numerical analysis with CoventorWare TM was used to compare thermal properties during chip electrophoresis of diamond and glass microchips of the same geometries. Temperature distributions in microchips were demonstrated. Thermal, electrical, optical, chemical and mechanical parameters of the polycrystalline diamond layers are advantageous over traditionally used materials for microfluidic devices. Especially, a very high thermal conductivity coefficient gives a possibility of very efficient dissipation of Joule heat from the diamond electrophoretic microchip. This enables manufacturing of a new generation of microdevices.

  1. Diamond electrophoretic microchips-Joule heating effects

    Energy Technology Data Exchange (ETDEWEB)

    Karczemska, Anna T., E-mail: anna.karczemska@p.lodz.pl [Technical University of Lodz, Institute of Turbomachinery, 219/223 Wolczanska str., Lodz (Poland); Witkowski, Dariusz [Technical University of Lodz, Institute of Turbomachinery, 219/223 Wolczanska str., Lodz (Poland); Ralchenko, Victor, E-mail: ralchenko@nsc.gpi.ru [General Physics Institute, Russian Academy of Science, 38 Vavilov str., Moscow (Russian Federation); Bolshakov, Andrey; Sovyk, Dmitry [General Physics Institute, Russian Academy of Science, 38 Vavilov str., Moscow (Russian Federation); Lysko, Jan M., E-mail: jmlysko@ite.waw.pl [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Fijalkowski, Mateusz, E-mail: petr.louda@vslib.cz [Technical University of Liberec, Faculty of Mechanical Engineering (Czech Republic); Bodzenta, Jerzy, E-mail: jerzy.bodzenta@polsl.pl [Silesian University of Technology, Institute of Physics, 2 Krzywoustego str., 44-100 Gliwice (Poland); Hassard, John, E-mail: j.hassard@imperial.ac.uk [Imperial College of Science, Technology and Medicine, London (United Kingdom)

    2011-03-15

    Microchip electrophoresis (MCE) has become a mature separation technique in the recent years. In the presented research, a polycrystalline diamond electrophoretic microchip was manufactured with a microwave plasma chemical vapour deposition (MPCVD) method. A replica technique (mould method) was used to manufacture microstructures in diamond. A numerical analysis with CoventorWare{sup TM} was used to compare thermal properties during chip electrophoresis of diamond and glass microchips of the same geometries. Temperature distributions in microchips were demonstrated. Thermal, electrical, optical, chemical and mechanical parameters of the polycrystalline diamond layers are advantageous over traditionally used materials for microfluidic devices. Especially, a very high thermal conductivity coefficient gives a possibility of very efficient dissipation of Joule heat from the diamond electrophoretic microchip. This enables manufacturing of a new generation of microdevices.

  2. Lie algebra contractions on two-dimensional hyperboloid

    International Nuclear Information System (INIS)

    Pogosyan, G. S.; Yakhno, A.

    2010-01-01

    The Inoenue-Wigner contraction from the SO(2, 1) group to the Euclidean E(2) and E(1, 1) group is used to relate the separation of variables in Laplace-Beltrami (Helmholtz) equations for the four corresponding two-dimensional homogeneous spaces: two-dimensional hyperboloids and two-dimensional Euclidean and pseudo-Euclidean spaces. We show how the nine systems of coordinates on the two-dimensional hyperboloids contracted to the four systems of coordinates on E 2 and eight on E 1,1 . The text was submitted by the authors in English.

  3. Quasi-two-dimensional holography

    International Nuclear Information System (INIS)

    Kutzner, J.; Erhard, A.; Wuestenberg, H.; Zimpfer, J.

    1980-01-01

    The acoustical holography with numerical reconstruction by area scanning is memory- and time-intensive. With the experiences by the linear holography we tried to derive a scanning for the evaluating of the two-dimensional flaw-sizes. In most practical cases it is sufficient to determine the exact depth extension of a flaw, whereas the accuracy of the length extension is less critical. For this reason the applicability of the so-called quasi-two-dimensional holography is appropriate. The used sound field given by special probes is divergent in the inclined plane and light focussed in the perpendicular plane using cylindrical lenses. (orig.) [de

  4. Topology optimization of two-dimensional waveguides

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole

    2003-01-01

    In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss.......In this work we use the method of topology optimization to design two-dimensional waveguides with low transmission loss....

  5. Traditional Semiconductors in the Two-Dimensional Limit.

    Science.gov (United States)

    Lucking, Michael C; Xie, Weiyu; Choe, Duk-Hyun; West, Damien; Lu, Toh-Ming; Zhang, S B

    2018-02-23

    Interest in two-dimensional materials has exploded in recent years. Not only are they studied due to their novel electronic properties, such as the emergent Dirac fermion in graphene, but also as a new paradigm in which stacking layers of distinct two-dimensional materials may enable different functionality or devices. Here, through first-principles theory, we reveal a large new class of two-dimensional materials which are derived from traditional III-V, II-VI, and I-VII semiconductors. It is found that in the ultrathin limit the great majority of traditional binary semiconductors studied (a series of 28 semiconductors) are not only kinetically stable in a two-dimensional double layer honeycomb structure, but more energetically stable than the truncated wurtzite or zinc-blende structures associated with three dimensional bulk. These findings both greatly increase the landscape of two-dimensional materials and also demonstrate that in the double layer honeycomb form, even ordinary semiconductors, such as GaAs, can exhibit exotic topological properties.

  6. Sufficient Controllability Condition for Affine Systems with Two-Dimensional Control and Two-Dimensional Zero Dynamics

    Directory of Open Access Journals (Sweden)

    D. A. Fetisov

    2015-01-01

    Full Text Available The controllability conditions are well known if we speak about linear stationary systems: a linear stationary system is controllable if and only if the dimension of the state vector is equal to the rank of the controllability matrix. The concept of the controllability matrix is extended to affine systems, but relations between affine systems controllability and properties of this matrix are more complicated. Various controllability conditions are set for affine systems, but they deal as usual either with systems of some special form or with controllability in some small neighborhood of the concerned point. An affine system is known to be controllable if the system is equivalent to a system of a canonical form, which is defined and regular in the whole space of states. In this case, the system is said to be feedback linearizable in the space of states. However there are examples, which illustrate that a system can be controllable even if it is not feedback linearizable in any open subset in the space of states. In this article we deal with such systems.Affine systems with two-dimensional control are considered. The system in question is assumed to be equivalent to a system of a quasicanonical form with two-dimensional zero dynamics which is defined and regular in the whole space of states. Therefore the controllability of the original system is equivalent to the controllability of the received system of a quasicanonical form. In this article the sufficient condition for an available solution of the terminal problem is proven for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. The condition is valid in the case of an arbitrary time interval and arbitrary initial and finite states of the system. Therefore the controllability condition is set for systems of a quasicanonical form with two-dimensional control and two-dimensional zero dynamics. An example is given which illustrates how the proved

  7. Gc protein-derived macrophage activating factor (GcMAF): isoelectric focusing pattern and tumoricidal activity.

    Science.gov (United States)

    Mohamad, Saharuddin Bin; Nagasawa, Hideko; Sasaki, Hideyuki; Uto, Yoshihiro; Nakagawa, Yoshinori; Kawashima, Ken; Hori, Hitoshi

    2003-01-01

    Gc protein is the precursor for Gc protein-derived macrophage activating factor (GcMAF), with three phenotypes: Gc1f, Gc1s and Gc2, based on its electrophoretic mobility. The difference in electrophoretic mobility is because of the difference in its posttranslational sugar moiety composition. We compared the difference between Gc protein and GcMAF electrophoretic mobility using the isoelectric focusing (IEF) method. The tumoricidal activity of GcMAF-treated macrophage was evaluated after coculture with L-929 cell. The tumoricidal mechanism was investigated using TNF bioassay and nitric oxide (NO) release. The difference in Gc protein and GcMAF electrophoretic mobility was detected. The tumoricidal activity of GcMAF-treated macrophage was detected, but no release of TNF and NO was detected. The difference of isoelectric focusing mobility in Gc protein and GcMAF would be useful to develop a GcMAF detection method. GcMAF increased macrophage tumoricidal activity but TNF and NO release were not involved in the mechanism.

  8. Electrophoretic deposition of biomaterials

    Science.gov (United States)

    Boccaccini, A. R.; Keim, S.; Ma, R.; Li, Y.; Zhitomirsky, I.

    2010-01-01

    Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields. PMID:20504802

  9. ANALOGIES IN THE 2-DIMENSIONAL SPATIAL ARRANGEMENT OF ADSORBED PROTEINS AND ADHERING BACTERIA - BOVINE SERUM-ALBUMIN AND STREPTOCOCCUS-SANGUIS-12

    NARCIS (Netherlands)

    BUSSCHER, HJ; VANDERMEI, HC; SCHAKENRAAD, JM

    1991-01-01

    Neither proteins nor bacteria adsorb or adhere homogeneously to a substratum surface. The final two-dimensional spatial arrangement depends on a complicated interplay between protein-protein (bacterium-bacterium) and protein (bacterium)-substratum interactions and the prevailing hydrodynamic

  10. Electrophoretic Retardation of Colloidal Particles in Nonpolar Liquids

    Directory of Open Access Journals (Sweden)

    Filip Strubbe

    2013-04-01

    Full Text Available We have measured the electrophoretic mobility of single, optically trapped colloidal particles, while gradually depleting the co-ions and counterions in the liquid around the particle by applying a dc voltage. This is achieved in a nonpolar liquid, where charged reverse micelles act as co-ions and counterions. By increasing the dc voltage, the mobility first increases when the concentrations of co-ions and counterions near the particle start to decrease. At sufficiently high dc voltage (around 2 V, the mobility reaches a saturation value when the co-ions and counterions are fully separated. The increase in mobility is larger when the equilibrium ionic strength is higher. The dependence of the experimental data on the equilibrium ionic strength and on the applied voltage is in good agreement with the standard theory of electrophoretic retardation, assuming that the bare particle charge remains constant. This method is useful for studying the electrophoretic retardation effect and charging mechanisms for nonpolar colloids, and it sheds light on previously unexplained particle acceleration in electronic ink devices.

  11. Two-dimensional flexible nanoelectronics

    Science.gov (United States)

    Akinwande, Deji; Petrone, Nicholas; Hone, James

    2014-12-01

    2014/2015 represents the tenth anniversary of modern graphene research. Over this decade, graphene has proven to be attractive for thin-film transistors owing to its remarkable electronic, optical, mechanical and thermal properties. Even its major drawback--zero bandgap--has resulted in something positive: a resurgence of interest in two-dimensional semiconductors, such as dichalcogenides and buckled nanomaterials with sizeable bandgaps. With the discovery of hexagonal boron nitride as an ideal dielectric, the materials are now in place to advance integrated flexible nanoelectronics, which uniquely take advantage of the unmatched portfolio of properties of two-dimensional crystals, beyond the capability of conventional thin films for ubiquitous flexible systems.

  12. A metrological study of autoradiographs from two-dimensional gel electrophoresis.

    Science.gov (United States)

    Valiron, O; Lefkovits, I; Garderet, P; Steinberg, C

    1984-12-01

    Samples prepared from a single batch of labeled cells were subjected to two-dimensional gel electrophoresis and autoradiography. Three factors were varied: total quantity of protein, quantity of labeled protein, and exposure time. The mean background absorbance of the film remained identical (about 0.5 A) for all the treated series, whatever the exposure time and whether or not there were unlabeled proteins in the sample. Hence any spot with a peak A of the same order of magnitude can be seen. The standard deviation was about 0.05 A. Thus, the measurement precision is 2.5% of full scale for digitalization over 0 to 2 A. We derived experimental calibration curves, which are neither linear nor logarithmic because of the film response and which can be used on randomly chosen spots.

  13. Protein-protein interaction site predictions with three-dimensional probability distributions of interacting atoms on protein surfaces.

    Directory of Open Access Journals (Sweden)

    Ching-Tai Chen

    Full Text Available Protein-protein interactions are key to many biological processes. Computational methodologies devised to predict protein-protein interaction (PPI sites on protein surfaces are important tools in providing insights into the biological functions of proteins and in developing therapeutics targeting the protein-protein interaction sites. One of the general features of PPI sites is that the core regions from the two interacting protein surfaces are complementary to each other, similar to the interior of proteins in packing density and in the physicochemical nature of the amino acid composition. In this work, we simulated the physicochemical complementarities by constructing three-dimensional probability density maps of non-covalent interacting atoms on the protein surfaces. The interacting probabilities were derived from the interior of known structures. Machine learning algorithms were applied to learn the characteristic patterns of the probability density maps specific to the PPI sites. The trained predictors for PPI sites were cross-validated with the training cases (consisting of 432 proteins and were tested on an independent dataset (consisting of 142 proteins. The residue-based Matthews correlation coefficient for the independent test set was 0.423; the accuracy, precision, sensitivity, specificity were 0.753, 0.519, 0.677, and 0.779 respectively. The benchmark results indicate that the optimized machine learning models are among the best predictors in identifying PPI sites on protein surfaces. In particular, the PPI site prediction accuracy increases with increasing size of the PPI site and with increasing hydrophobicity in amino acid composition of the PPI interface; the core interface regions are more likely to be recognized with high prediction confidence. The results indicate that the physicochemical complementarity patterns on protein surfaces are important determinants in PPIs, and a substantial portion of the PPI sites can be predicted

  14. Protein-Protein Interaction Site Predictions with Three-Dimensional Probability Distributions of Interacting Atoms on Protein Surfaces

    Science.gov (United States)

    Chen, Ching-Tai; Peng, Hung-Pin; Jian, Jhih-Wei; Tsai, Keng-Chang; Chang, Jeng-Yih; Yang, Ei-Wen; Chen, Jun-Bo; Ho, Shinn-Ying; Hsu, Wen-Lian; Yang, An-Suei

    2012-01-01

    Protein-protein interactions are key to many biological processes. Computational methodologies devised to predict protein-protein interaction (PPI) sites on protein surfaces are important tools in providing insights into the biological functions of proteins and in developing therapeutics targeting the protein-protein interaction sites. One of the general features of PPI sites is that the core regions from the two interacting protein surfaces are complementary to each other, similar to the interior of proteins in packing density and in the physicochemical nature of the amino acid composition. In this work, we simulated the physicochemical complementarities by constructing three-dimensional probability density maps of non-covalent interacting atoms on the protein surfaces. The interacting probabilities were derived from the interior of known structures. Machine learning algorithms were applied to learn the characteristic patterns of the probability density maps specific to the PPI sites. The trained predictors for PPI sites were cross-validated with the training cases (consisting of 432 proteins) and were tested on an independent dataset (consisting of 142 proteins). The residue-based Matthews correlation coefficient for the independent test set was 0.423; the accuracy, precision, sensitivity, specificity were 0.753, 0.519, 0.677, and 0.779 respectively. The benchmark results indicate that the optimized machine learning models are among the best predictors in identifying PPI sites on protein surfaces. In particular, the PPI site prediction accuracy increases with increasing size of the PPI site and with increasing hydrophobicity in amino acid composition of the PPI interface; the core interface regions are more likely to be recognized with high prediction confidence. The results indicate that the physicochemical complementarity patterns on protein surfaces are important determinants in PPIs, and a substantial portion of the PPI sites can be predicted correctly with

  15. Analysis of protein incorporation of radioactive isotopes in the Chinese hamster ovary cell cycle by electronic sorting and gel microelectrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Pipkin, J.L.; Anson, J.F.; Hinson, W.G.; Schol, H.; Burns, E.R.; Casciano, D.A.

    1986-03-01

    The patterns of (3H)-leucine and (32P)-phosphate incorporation of proteins extracted with varying molarities of sodium chloride were analyzed from nuclei physically sorted from six fluorescence windows after propidium iodine staining of the G0 + G1 and G2 + M phases of the Chinese hamster ovary (CHO) cell cycle. Eight hundred nanograms of protein were used in each electrophoretic analysis obtained from 200,000 nuclei, a portion of the sample, from each window. Autoradiography was performed in a two-dimensional polyacrylamide gel ultra-microelectrophoresis apparatus (UMEA) designed and fabricated in this laboratory. There was a net reduction and/or loss of (3H)-leucine- and (32P)-phosphate-labeled protein regions from the autoradiographs occurring primarily in the G2 + M phase. Two phosphorylated proteins that were stage specific were observed in partitions of the G2 + M phase. The use of isolated proteins and the coelectrophoresis of these markers demonstrated the similarity in mobility of a number of proteins seen in the autoradiographs of proteins extracted with high and low salt molarities and implied they are synonymous. Coelectrophoresis indicated that a substantial number of high molecular weight proteins that decreased or disappeared at late stages of G2 + M and early mitosis were composed, in part, of nucleolar proteins.

  16. Electron crystallography of three dimensional protein crystals

    NARCIS (Netherlands)

    Georgieva, Dilyana

    2008-01-01

    This thesis describes an investigation of the potential of electron diffraction for studying three dimensional sub-micro-crystals of proteins and pharmaceuticals. A prerequisite for using electron diffraction for structural studies is the predictable availability of tiny crystals. A method for

  17. Approximate solutions for the two-dimensional integral transport equation. Solution of complex two-dimensional transport problems

    International Nuclear Information System (INIS)

    Sanchez, Richard.

    1980-11-01

    This work is divided into two parts: the first part deals with the solution of complex two-dimensional transport problems, the second one (note CEA-N-2166) treats the critically mixed methods of resolution. A set of approximate solutions for the isotropic two-dimensional neutron transport problem has been developed using the interface current formalism. The method has been applied to regular lattices of rectangular cells containing a fuel pin, cladding, and water, or homogenized structural material. The cells are divided into zones that are homogeneous. A zone-wise flux expansion is used to formulate a direct collision probability problem within a cell. The coupling of the cells is effected by making extra assumptions on the currents entering and leaving the interfaces. Two codes have been written: CALLIOPE uses a cylindrical cell model and one or three terms for the flux expansion, and NAUSICAA uses a two-dimensional flux representation and does a truly two-dimensional calculation inside each cell. In both codes, one or three terms can be used to make a space-independent expansion of the angular fluxes entering and leaving each side of the cell. The accuracies and computing times achieved with the different approximations are illustrated by numerical studies on two benchmark problems and by calculations performed in the APOLLO multigroup code [fr

  18. Two-dimensional topological field theories coupled to four-dimensional BF theory

    International Nuclear Information System (INIS)

    Montesinos, Merced; Perez, Alejandro

    2008-01-01

    Four-dimensional BF theory admits a natural coupling to extended sources supported on two-dimensional surfaces or string world sheets. Solutions of the theory are in one to one correspondence with solutions of Einstein equations with distributional matter (cosmic strings). We study new (topological field) theories that can be constructed by adding extra degrees of freedom to the two-dimensional world sheet. We show how two-dimensional Yang-Mills degrees of freedom can be added on the world sheet, producing in this way, an interactive (topological) theory of Yang-Mills fields with BF fields in four dimensions. We also show how a world sheet tetrad can be naturally added. As in the previous case the set of solutions of these theories are contained in the set of solutions of Einstein's equations if one allows distributional matter supported on two-dimensional surfaces. These theories are argued to be exactly quantizable. In the context of quantum gravity, one important motivation to study these models is to explore the possibility of constructing a background-independent quantum field theory where local degrees of freedom at low energies arise from global topological (world sheet) degrees of freedom at the fundamental level

  19. [Study on the method of two dimensional polycrylamide gel electrophoresis on rat condylar chondrocyte].

    Science.gov (United States)

    Wu, Tuo-jiang; Li, Huang; Ma, Qiao-lin; Wang, Wen-mei

    2010-08-01

    To investigate the protein profile by two dimensional polycrylamide gel electrophoresis on the rat condylar chondrocyte in vitro. The third-passage chondrocytes were harvested from the mandibular condyles of 2-day-old rats in this study. The protein profile of the rat mandibular condylar chondrocytes was examined by two dimensional polycrylamide gel electrophoresis (2-DE-PAGE). The 2-DE gel maps on different pH gradients were obtained. The result of modified coomassi blue-sliver staining and sliver staining was compared using Pdquest 7.1 image analysis software. The results showed that the good protein profile of the condylar chondrocytes was obtained by standard Bio-Rad manual. The protein was mainly in the field from pH4 to pH7. The 1203±86 protein points were examined on 2-DE gel map by modified coomassi blue-sliver staining, and 1769±97 protein points was examined by sliver staining. The silver staining map showed more distinctly but higher background than modified coomassi blue-sliver staining. The protein profile of the condylar chondrocytes enriches the proteomic database and gives evidence to further proteomic research. The 2-DE map obtained by modified coomassi blue-sliver staining is more suitable for MALDI-TOF mass identification. Supported by National Natural Science Foundation of China (Grant No. C30700963), China Postdoctoral Science Foundation(Grant No.20090461088), Jiangsu Provincial Postdoctoral Science Foundation (Grant No.0802003C) and Nanjing City's Science and Technology Foundation (Grant No.200905011).

  20. Beginning Introductory Physics with Two-Dimensional Motion

    Science.gov (United States)

    Huggins, Elisha

    2009-01-01

    During the session on "Introductory College Physics Textbooks" at the 2007 Summer Meeting of the AAPT, there was a brief discussion about whether introductory physics should begin with one-dimensional motion or two-dimensional motion. Here we present the case that by starting with two-dimensional motion, we are able to introduce a considerable…

  1. Two-dimensional thermofield bosonization

    International Nuclear Information System (INIS)

    Amaral, R.L.P.G.; Belvedere, L.V.; Rothe, K.D.

    2005-01-01

    The main objective of this paper was to obtain an operator realization for the bosonization of fermions in 1 + 1 dimensions, at finite, non-zero temperature T. This is achieved in the framework of the real-time formalism of Thermofield Dynamics. Formally, the results parallel those of the T = 0 case. The well-known two-dimensional Fermion-Boson correspondences at zero temperature are shown to hold also at finite temperature. To emphasize the usefulness of the operator realization for handling a large class of two-dimensional quantum field-theoretic problems, we contrast this global approach with the cumbersome calculation of the fermion-current two-point function in the imaginary-time formalism and real-time formalisms. The calculations also illustrate the very different ways in which the transmutation from Fermi-Dirac to Bose-Einstein statistics is realized

  2. The Utilization of Triton X-100 for Enhanced Two-Dimensional Liquid-Phase Proteomics

    OpenAIRE

    Kim, Mina; Lee, Sang-Hee; Min, Jiho; Kobayashi, Fumihisa; Um, Hyun-Ju; Kim, Yang-Hoon

    2011-01-01

    One of the main challenges in proteomics lies in obtaining a high level of reproducible fractionation of the protein samples. Automated two-dimensional liquid phase fractionation (PF2D) system manufactured by Beckman Coulter provides a process well suited for proteome studies. However, the protein recovery efficiency of such system is low when a protocol recommended by the manufacturer is used for metaproteome profiling of environmental sample. In search of an alternative method that can over...

  3. Study on the plasma proteins of A-bomb survived patients including those suffered by the remained radioactivities. Report 2. Quantitative observation of the plasma protein fractions by electrophoretic test and to solve the problems for physiological clinical significance of its patterns

    Energy Technology Data Exchange (ETDEWEB)

    Makidono, J; Takanashi, S; Yoshimoto, T; Kai, T; Yoshimoto, K; Matsutani, M; Miura, M

    1963-10-01

    The plasma proteins of A-bombed survivors, healthy persons, long term x-ray equipment handling people (for instance the radiologists and x-ray technicians), cancer patients, and tumor irradiated cancer patients were examined by the electrophoretic test. It was found that the electrophoretic patterns of plasma proteins could be divided into normal (N-pattern) and abnormal (..beta.. and ..gamma.. patterns) patterns, when they were classified according to the accents of each fraction. The patterns of the healthy persons and the long term x-ray handling people showed normal (N) pattern, however, it showed 43% abnormal patterns in A-bombed survivors and 48% in cancer patients. Furthermore, the patterns could be changed by radiotherapy to cancer, ie., from N to ..beta.. or vice versa. As a result of the quantitative observation about individual pattern, the accents of ..beta..-globulins in ..beta..-patterns and ..gamma..-globulins in ..gamma..-patterns were found. The globulins increased in the A bomb survivors and the long term x-ray handling people, and this increase was also seen in the cases of cancer patients which showed 85% of them were effected with uclers (self disintegrated) by clinical examinations. A physiological clinical significance of these abnormal patterns (..beta.. and ..gamma..) in the plasma proteins indicates the disorders in its body and an important immunological meaning. Abnormal patterns in those who suffered by the remained radioactivities caused by the A-bomb showed 70%, whose average was much higher than those of direct A-bombed survivors. It is pointed out that, in recent days, there is a trend of more and gradual increase in the malignant neoplamsm than the disorders of direct A-bombed survivors.

  4. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  5. Effects of cooking methods on electrophoretic patterns of rainbow trout

    Directory of Open Access Journals (Sweden)

    Yasemen Yanar

    2011-07-01

    Full Text Available The aim of this study was to determine the effects of different cooking methods on the electrophoretic patterns of rainbow trout (Oncorhynchus mykiss fillets using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Raw rainbow trout were deep-fried, microwaved, grilled, and baked and then monitored for changes in the electrophoretic pattern. All cooking methods resulted in significant moisture loss when compared to the raw sample (P

  6. Optimization of the southern electrophoretic transfer method

    International Nuclear Information System (INIS)

    Allison, M.A.; Fujimura, R.K.

    1987-01-01

    The technique of separating DNA fragments using agarose gel electrophoresis is essential in the analysis of nucleic acids. Further, after the method of transferring specific DNA fragments from those agarose gels to cellulose nitrate membranes was developed in 1975, a method was developed to transfer DNA, RNA, protein and ribonucleoprotein particles from various gels onto diazobenzyloxymethyl (DBM) paper using electrophoresis as well. This paper describes the optimum conditions for quantitative electrophoretic transfer of DNA onto nylon membranes. This method exemplifies the ability to hybridize the membrane more than once with specific RNA probes by providing sufficient retention of the DNA. Furthermore, the intrinsic properties of the nylon membrane allow for an increase in the efficiency and resolution of transfer while using somewhat harsh alkaline conditions. The use of alkaline conditions is of critical importance since we can now denature the DNA during transfer and thus only a short pre-treatment in acid is required for depurination. 9 refs., 7 figs

  7. Piezoelectricity in Two-Dimensional Materials

    KAUST Repository

    Wu, Tao

    2015-02-25

    Powering up 2D materials: Recent experimental studies confirmed the existence of piezoelectricity - the conversion of mechanical stress into electricity - in two-dimensional single-layer MoS2 nanosheets. The results represent a milestone towards embedding low-dimensional materials into future disruptive technologies. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.

  8. Two-dimensional confinement of heavy fermions

    International Nuclear Information System (INIS)

    Shishido, Hiroaki; Shibauchi, Takasada; Matsuda, Yuji; Terashima, Takahito

    2010-01-01

    Metallic systems with the strongest electron correlations are realized in certain rare-earth and actinide compounds whose physics are dominated by f-electrons. These materials are known as heavy fermions, so called because the effective mass of the conduction electrons is enhanced via correlation effects up to as much as several hundreds times the free electron mass. To date the electronic structure of all heavy-fermion compounds is essentially three-dimensional. Here we report on the first realization of a two-dimensional heavy-fermion system, where the dimensionality is adjusted in a controllable fashion by fabricating heterostructures using molecular beam epitaxy. The two-dimensional heavy fermion system displays striking deviations from the standard Fermi liquid low-temperature electronic properties. (author)

  9. Two-dimensional topological photonics

    Science.gov (United States)

    Khanikaev, Alexander B.; Shvets, Gennady

    2017-12-01

    Originating from the studies of two-dimensional condensed-matter states, the concept of topological order has recently been expanded to other fields of physics and engineering, particularly optics and photonics. Topological photonic structures have already overturned some of the traditional views on wave propagation and manipulation. The application of topological concepts to guided wave propagation has enabled novel photonic devices, such as reflection-free sharply bent waveguides, robust delay lines, spin-polarized switches and non-reciprocal devices. Discrete degrees of freedom, widely used in condensed-matter physics, such as spin and valley, are now entering the realm of photonics. In this Review, we summarize the latest advances in this highly dynamic field, with special emphasis on the experimental work on two-dimensional photonic topological structures.

  10. Structures of two-dimensional three-body systems

    International Nuclear Information System (INIS)

    Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

    1996-01-01

    Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

  11. Strategies for the capillary electrophoretic separation of indole alkaloids in Psilocybe semilanceata.

    Science.gov (United States)

    Pedersen-Bjergaard, S; Rasmussen, K E; Sannes, E

    1998-01-01

    While the hallucinogenic mushrooms Psilocybe semilanceata have previously been analyzed for the indole alkaloids psilocybin and baeocystin by capillary zone electrophoresis (CZE) at pH 11.5, the present work focused on the development of an alternative and complementary capillary electrophoretic method for their identification. Owing to their structural similarity and zwitterionic nature, the compounds were difficult to resolve based on different interactions with cationic or anionic micelles. However, while the attempts with micellar electrokinetic chromatography (MEKC) were unsuccessful, rapid derivatization with propyl chloroformate and reanalysis by CZE at pH 11.5 was effective to support identification of the two indole alkaloids. Psilocin was difficult to analyze by CZE at pH 11.5 owing to comigration with the electroosmotic flow. For this compound, the pH of the running buffer was reduced to 7.2 to effectively enhance the electrophoretic mobility.

  12. Polymorphism of myofibrillar proteins of rabbit skeletal-muscle fibres. An electrophoretic study of single fibres.

    OpenAIRE

    Salviati, G; Betto, R; Danieli Betto, D

    1982-01-01

    Rabbit predominantly fast-twitch-fibre and predominantly slow-twitch-fibre skeletal muscles of the hind limbs, the psoas, the diaphragm and the masseter muscles were fibre-typed by one-dimensional polyacrylamide-gel electrophoresis of the myofibrillar proteins of chemically skinned single fibres. Investigation of the distribution of fast-twitch-fibre and slow-twitch-fibre isoforms of myosin light chains and the type of myosin heavy chains, based on peptide 'maps' published in Cleveland. Fisch...

  13. X-ray imaging device for one-dimensional and two-dimensional radioscopy

    International Nuclear Information System (INIS)

    1978-01-01

    The X-ray imaging device for the selectable one-dimensional or two-dimensional pictures of objects illuminated by X-rays, comprising an X-ray source, an X-ray screen, and an opto-electrical picture development device placed behind the screen, is characterized by an anamorphotic optical system, which is positioned with a one-dimensional illumination between the X-ray screen and the opto-electrical device and that a two-dimensional illumination will be developed, and that in view of the lens system which forms part of the opto-electrical device, there is placed an X-ray screen in a specified beam direction so that a magnified image may be formed by equalisation of the distance between the X-ray screen and the lens system. (G.C.)

  14. Hamiltonian formalism of two-dimensional Vlasov kinetic equation.

    Science.gov (United States)

    Pavlov, Maxim V

    2014-12-08

    In this paper, the two-dimensional Benney system describing long wave propagation of a finite depth fluid motion and the multi-dimensional Russo-Smereka kinetic equation describing a bubbly flow are considered. The Hamiltonian approach established by J. Gibbons for the one-dimensional Vlasov kinetic equation is extended to a multi-dimensional case. A local Hamiltonian structure associated with the hydrodynamic lattice of moments derived by D. J. Benney is constructed. A relationship between this hydrodynamic lattice of moments and the two-dimensional Vlasov kinetic equation is found. In the two-dimensional case, a Hamiltonian hydrodynamic lattice for the Russo-Smereka kinetic model is constructed. Simple hydrodynamic reductions are presented.

  15. Novel target design algorithm for two-dimensional optical storage (TwoDOS)

    NARCIS (Netherlands)

    Huang, Li; Chong, T.C.; Vijaya Kumar, B.V.K.; Kobori, H.

    2004-01-01

    In this paper we introduce the Hankel transform based channel model of Two-Dimensional Optical Storage (TwoDOS) system. Based on this model, the two-dimensional (2D) minimum mean-square error (MMSE) equalizer has been derived and applied to some simple but common cases. The performance of the 2D

  16. Two-dimensional ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, L M; Fridkin, Vladimir M; Palto, Sergei P [A.V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, Moscow, Russian Federaion (Russian Federation); Bune, A V; Dowben, P A; Ducharme, Stephen [Department of Physics and Astronomy, Behlen Laboratory of Physics, Center for Materials Research and Analysis, University of Nebraska-Linkoln, Linkoln, NE (United States)

    2000-03-31

    The investigation of the finite-size effect in ferroelectric crystals and films has been limited by the experimental conditions. The smallest demonstrated ferroelectric crystals had a diameter of {approx}200 A and the thinnest ferroelectric films were {approx}200 A thick, macroscopic sizes on an atomic scale. Langmuir-Blodgett deposition of films one monolayer at a time has produced high quality ferroelectric films as thin as 10 A, made from polyvinylidene fluoride and its copolymers. These ultrathin films permitted the ultimate investigation of finite-size effects on the atomic thickness scale. Langmuir-Blodgett films also revealed the fundamental two-dimensional character of ferroelectricity in these materials by demonstrating that there is no so-called critical thickness; films as thin as two monolayers (1 nm) are ferroelectric, with a transition temperature near that of the bulk material. The films exhibit all the main properties of ferroelectricity with a first-order ferroelectric-paraelectric phase transition: polarization hysteresis (switching); the jump in spontaneous polarization at the phase transition temperature; thermal hysteresis in the polarization; the increase in the transition temperature with applied field; double hysteresis above the phase transition temperature; and the existence of the ferroelectric critical point. The films also exhibit a new phase transition associated with the two-dimensional layers. (reviews of topical problems)

  17. A comparison of the adsorption of saliva proteins and some typical proteins onto the surface of hydroxyapatite

    NARCIS (Netherlands)

    Kawasaki, K; Kambara, M; Matsumura, H; Norde, W

    2003-01-01

    Adsorption of protein from saliva on hydroxyapatite was compared with adsorption of several typical proteins with different electric charges, i.e. lysozyme, human serum albumin, beta-lactoglobulin and ovalbumin. Adsorbed amounts of these proteins were determined and electrophoretic mobilities of

  18. A comparison of the adsorption of saliva proteins and some typical proteins onto the surface of hydroxyapatite

    NARCIS (Netherlands)

    Kawasaki, K.; Kambara, M.; Matsumura, H.; Norde, W.

    2003-01-01

    Adsorption of protein from saliva on hydroxyapatite was compared with adsorption of several typical proteins with different electric charges, i.e. lysozyme, human serum albumin, @b-lactoglobulin and ovalbumin. Adsorbed amounts of these proteins were determined and electrophoretic mobilities of

  19. Electrophoretic Porosimetry of Sol-Gels

    Science.gov (United States)

    Snow, L. A.; Smith, D. D.; Sibille, L.; Hunt, A. J.; Ng, J.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    It has been hypothesized that gravity has an effect on the formation and resulting microstructure of sol-gels. In order to more clearly resolve the effect of gravity, pores may be non-destructively analyzed in the wet gel, circumventing the shrinkage and coarsening associated with the drying procedure. We discuss the development of an electrophoretic technique, analogous to affinity chromatography, for the determination of pore size distribution and its application to silica gels. Specifically a monodisperse charged dye is monitored by an optical densitometer as it moves through the wet gel under the influence of an electric field. The transmittance data (output) represents the convolution of the dye concentration profile at the beginning of the run (input) with the pore size distribution (transfer function), i.e. linear systems theory applies. Because of the practical difficulty in producing a delta function input dye profile we prefer instead to use a step function. Average pore size is then related to the velocity of this dye front, while the pore size distribution is related to the spreading of the front. Preliminary results of this electrophoretic porosimetry and its application to ground and space-grown samples will be discussed.

  20. Protein identification from two-dimensional gel electrophoresis analysis of Klebsiella pneumoniae by combined use of mass spectrometry data and raw genome sequences

    Directory of Open Access Journals (Sweden)

    Zeng An-Ping

    2003-12-01

    Full Text Available Abstract Separation of proteins by two-dimensional gel electrophoresis (2-DE coupled with identification of proteins through peptide mass fingerprinting (PMF by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS is the widely used technique for proteomic analysis. This approach relies, however, on the presence of the proteins studied in public-accessible protein databases or the availability of annotated genome sequences of an organism. In this work, we investigated the reliability of using raw genome sequences for identifying proteins by PMF without the need of additional information such as amino acid sequences. The method is demonstrated for proteomic analysis of Klebsiella pneumoniae grown anaerobically on glycerol. For 197 spots excised from 2-DE gels and submitted for mass spectrometric analysis 164 spots were clearly identified as 122 individual proteins. 95% of the 164 spots can be successfully identified merely by using peptide mass fingerprints and a strain-specific protein database (ProtKpn constructed from the raw genome sequences of K. pneumoniae. Cross-species protein searching in the public databases mainly resulted in the identification of 57% of the 66 high expressed protein spots in comparison to 97% by using the ProtKpn database. 10 dha regulon related proteins that are essential for the initial enzymatic steps of anaerobic glycerol metabolism were successfully identified using the ProtKpn database, whereas none of them could be identified by cross-species searching. In conclusion, the use of strain-specific protein database constructed from raw genome sequences makes it possible to reliably identify most of the proteins from 2-DE analysis simply through peptide mass fingerprinting.

  1. Electrophoretic separations on paper: Past, present, and future-A review.

    Science.gov (United States)

    Nanthasurasak, Pavisara; Cabot, Joan Marc; See, Hong Heng; Guijt, Rosanne M; Breadmore, Michael C

    2017-09-08

    Point-of-collection (POC) devices aim for a fast, on-site detection for medical and environmental purposes. In this area, microfluidic Paper-based Analytical Devices (μPADs) have recently gained popularity because these are potentially cheap and environmentally friendly to produce, and easy to use. From an analytical perspective, paper is well known for its use as a substrate for chromatography, but less known for its use in electrophoretic separations. With the recent interest in μPADs, most applications are based on rather simple assays with relatively few applications incorporating an analytical separation. The focus of this review is on paper-based electrophoresis, originating with the key developments in the 1940s and 1950s as well as the recent developments of electrophoretic μPADs, and concluding with a critical discussion of the opportunities and challenges for electrophoretic μPADS in the future. Copyright © 2017. Published by Elsevier B.V.

  2. Two-Dimensional Materials for Sensing: Graphene and Beyond

    Directory of Open Access Journals (Sweden)

    Seba Sara Varghese

    2015-09-01

    Full Text Available Two-dimensional materials have attracted great scientific attention due to their unusual and fascinating properties for use in electronics, spintronics, photovoltaics, medicine, composites, etc. Graphene, transition metal dichalcogenides such as MoS2, phosphorene, etc., which belong to the family of two-dimensional materials, have shown great promise for gas sensing applications due to their high surface-to-volume ratio, low noise and sensitivity of electronic properties to the changes in the surroundings. Two-dimensional nanostructured semiconducting metal oxide based gas sensors have also been recognized as successful gas detection devices. This review aims to provide the latest advancements in the field of gas sensors based on various two-dimensional materials with the main focus on sensor performance metrics such as sensitivity, specificity, detection limit, response time, and reversibility. Both experimental and theoretical studies on the gas sensing properties of graphene and other two-dimensional materials beyond graphene are also discussed. The article concludes with the current challenges and future prospects for two-dimensional materials in gas sensor applications.

  3. Two-dimensional calculus

    CERN Document Server

    Osserman, Robert

    2011-01-01

    The basic component of several-variable calculus, two-dimensional calculus is vital to mastery of the broader field. This extensive treatment of the subject offers the advantage of a thorough integration of linear algebra and materials, which aids readers in the development of geometric intuition. An introductory chapter presents background information on vectors in the plane, plane curves, and functions of two variables. Subsequent chapters address differentiation, transformations, and integration. Each chapter concludes with problem sets, and answers to selected exercises appear at the end o

  4. A Chip-Capillary Hybrid Device for Automated Transfer of Sample Pre-Separated by Capillary Isoelectric Focusing to Parallel Capillary Gel Electrophoresis for Two-Dimensional Protein Separation

    Science.gov (United States)

    Lu, Joann J.; Wang, Shili; Li, Guanbin; Wang, Wei; Pu, Qiaosheng; Liu, Shaorong

    2012-01-01

    In this report, we introduce a chip-capillary hybrid device to integrate capillary isoelectric focusing (CIEF) with parallel capillary sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS-PAGE) or capillary gel electrophoresis (CGE) toward automating two-dimensional (2D) protein separations. The hybrid device consists of three chips that are butted together. The middle chip can be moved between two positions to re-route the fluidic paths, which enables the performance of CIEF and injection of proteins partially resolved by CIEF to CGE capillaries for parallel CGE separations in a continuous and automated fashion. Capillaries are attached to the other two chips to facilitate CIEF and CGE separations and to extend the effective lengths of CGE columns. Specifically, we illustrate the working principle of the hybrid device, develop protocols for producing and preparing the hybrid device, and demonstrate the feasibility of using this hybrid device for automated injection of CIEF-separated sample to parallel CGE for 2D protein separations. Potentials and problems associated with the hybrid device are also discussed. PMID:22830584

  5. Phase transitions in two-dimensional systems

    International Nuclear Information System (INIS)

    Salinas, S.R.A.

    1983-01-01

    Some experiences are related using synchrotron radiation beams, to characterize solid-liquid (fusion) and commensurate solid-uncommensurate solid transitions in two-dimensional systems. Some ideas involved in the modern theories of two-dimensional fusion are shortly exposed. The systems treated consist of noble gases (Kr,Ar,Xe) adsorbed in the basal plane of graphite and thin films formed by some liquid crystal shells. (L.C.) [pt

  6. The theory of critical phenomena in two-dimensional systems

    International Nuclear Information System (INIS)

    Olvera de la C, M.

    1981-01-01

    An exposition of the theory of critical phenomena in two-dimensional physical systems is presented. The first six chapters deal with the mean field theory of critical phenomena, scale invariance of the thermodynamic functions, Kadanoff's spin block construction, Wilson's renormalization group treatment of critical phenomena in configuration space, and the two-dimensional Ising model on a triangular lattice. The second part of this work is made of four chapters devoted to the application of the ideas expounded in the first part to the discussion of critical phenomena in superfluid films, two-dimensional crystals and the two-dimensional XY model of magnetic systems. Chapters seven to ten are devoted to the following subjects: analysis of long range order in one, two, and three-dimensional physical systems. Topological defects in the XY model, in superfluid films and in two-dimensional crystals. The Thouless-Kosterlitz iterated mean field theory of the dipole gas. The renormalization group treatment of the XY model, superfluid films and two-dimensional crystal. (author)

  7. Crystallization of SHARPIN using an automated two-dimensional grid screen for optimization.

    Science.gov (United States)

    Stieglitz, Benjamin; Rittinger, Katrin; Haire, Lesley F

    2012-07-01

    An N-terminal fragment of human SHARPIN was recombinantly expressed in Escherichia coli, purified and crystallized. Crystals suitable for X-ray diffraction were obtained by a one-step optimization of seed dilution and protein concentration using a two-dimensional grid screen. The crystals belonged to the primitive tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 61.55, c = 222.81 Å. Complete data sets were collected from native and selenomethionine-substituted protein crystals at 100 K to 2.6 and 2.0 Å resolution, respectively.

  8. The two capsid proteins of maize rayado fino virus contain common peptide sequences.

    Science.gov (United States)

    Falk, B W; Tsai, J H

    1986-01-01

    Virions of maize rayado fino virus (MRFV) were purified and two major capsid proteins (ca. Mr 29,000 and 22,000) were resolved by SDS-PAGE. When the two major capsid proteins were isolated from gels and compared by one-dimensional peptide mapping after digestion with Staphylococcus aureus V-8 protease, indistinguishable peptide maps were obtained, suggesting that these two proteins contain common peptide sequences. Some preparations also showed minor protein components that were intermediate between the Mr 22,000 and Mr 29,000 capsid proteins. One of the minor proteins, ca. Mr 27,000, gave a peptide map indistinguishable from the major capsid proteins. In vitro ageing of partially purified preparations or virion treatment with proteolytic enzymes failed to show conversion of the Mr 29,000 protein to a Mr 22,000. Protease inhibitors added to the buffers used for virion purification did not affect the apparent 1:3 ratio of 29,000 to 22,000 proteins in the purified preparations.

  9. Two memory associated genes regulated by amyloid precursor protein intracellular domain ovel insights into the pathogenesis of learning and memory impairment in Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    Chuandong Zheng; Xi Gu; Zhimei Zhong; Rui Zhu; Tianming Gao; Fang Wang

    2012-01-01

    In this study, we employed chromatin immunoprecipitation, a useful method for studying the locations of transcription factors bound to specific DNA regions in specific cells, to investigate amyloid precursor protein intracellular domain binding sites in chromatin DNA from hippocampal neurons of rats, and to screen out five putative genes associated with the learning and memory functions. The promoter regions of the calcium/calmodulin-dependent protein kinase II alpha and glutamate receptor-2 genes were amplified by PCR from DNA products immunoprecipitated by amyloid precursor protein intracellular domain. An electrophoretic mobility shift assay and western blot analysis suggested that the promoter regions of these two genes associated with learning and memory were bound by amyloid precursor protein intracellular domain (in complex form). Our experimental findings indicate that the amyloid precursor protein intracellular domain is involved in the transcriptional regulation of learning- and memory-associated genes in hippocampal neurons. These data may provide new insights into the molecular mechanism underlying the symptoms of progressive memory loss in Alzheimer's disease.

  10. Two- and three-dimensional proton NMR studies of apo-neocarzinostatin

    International Nuclear Information System (INIS)

    Xiaolian Gao; Burkhart, W.

    1991-01-01

    Neocarzinostatin (NCS) is an antitumor protein from Streptomyces carzinostaticus that is identical in apo-protein sequence with mitomalcin (MMC) from Streptomyces malayensis. The authors describe the use of apo-NCS as a model system for applying combined two-and three-dimensional (2D and 3D) proton NMR spectroscopy to the structure determination of proteins without isotope labeling. Strategies aimed at accurately assigning overlapped 2D cross-peaks by using semiautomated combined 2D and 3D data analysis are developed. Using this approach, they have assigned 99% of the protons, including those of the side chains, and identified about 1,270 intra- and interresidue proton-proton interactions (fixed distances are not included) in apo-NCS. Comparing these results with those reported recently on 2D NMR studies of apo-NCS demonstrated advantages of proton 3D NMR spectroscopy in protein spectral assignments. They are able to obtain more complete proton resonance and secondary structural assignments and find several misassignments in the earlier report. Strategies utilized in this work should be useful for developing automation procedures for spectral assignments

  11. Two- and three-dimensional CT analysis of ankle fractures

    International Nuclear Information System (INIS)

    Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

    1988-01-01

    CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

  12. On two-dimensionalization of three-dimensional turbulence in shell models

    DEFF Research Database (Denmark)

    Chakraborty, Sagar; Jensen, Mogens Høgh; Sarkar, A.

    2010-01-01

    Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and reproduced. Within the framework of shell m......-similar PDFs for longitudinal velocity differences are also presented for the rotating 3D turbulence case....

  13. Two-dimensional turbulent convection

    Science.gov (United States)

    Mazzino, Andrea

    2017-11-01

    We present an overview of the most relevant, and sometimes contrasting, theoretical approaches to Rayleigh-Taylor and mean-gradient-forced Rayleigh-Bénard two-dimensional turbulence together with numerical and experimental evidences for their support. The main aim of this overview is to emphasize that, despite the different character of these two systems, especially in relation to their steadiness/unsteadiness, turbulent fluctuations are well described by the same scaling relationships originated from the Bolgiano balance. The latter states that inertial terms and buoyancy terms balance at small scales giving rise to an inverse kinetic energy cascade. The main difference with respect to the inverse energy cascade in hydrodynamic turbulence [R. H. Kraichnan, "Inertial ranges in two-dimensional turbulence," Phys. Fluids 10, 1417 (1967)] is that the rate of cascade of kinetic energy here is not constant along the inertial range of scales. Thanks to the absence of physical boundaries, the two systems here investigated turned out to be a natural physical realization of the Kraichnan scaling regime hitherto associated with the elusive "ultimate state of thermal convection" [R. H. Kraichnan, "Turbulent thermal convection at arbitrary Prandtl number," Phys. Fluids 5, 1374-1389 (1962)].

  14. Protein solution structure determination using distances from two-dimensional nuclear Overhauser effect experiments: Effect of approximations on the accuracy of derived structures

    International Nuclear Information System (INIS)

    Thomas, P.D.; Basus, V.J.; James, T.L.

    1991-01-01

    Solution structures for many proteins have been determined to date utilizing interproton distance constraints estimated from two-dimensional nuclear Overhauser effect (2D NOE) spectra. Although the simple isolated spin pair approximation (ISPA) generally used can result in systematic errors in distances, the large number of constraints enables proteins structure to be defined with reasonably high resolution. Effects of these systematic errors on the resulting protein structure are examined. Iterative relaxation matrix calculations, which account for dipolar interactions between all protons in a molecule, can accurately determine internuclear distances with little or no a priori knowledge of the molecular structure. The value of this additional complexity is also addressed. To assess these distance determination methods, hypothetical experimental data, including random noise and peak overlap, are calculated for an arbitrary true protein structure. Three methods of obtaining distance constraints from 2D NOE peak intensities are examined: one entails a conservative use of ISPA, one assumes the ISPA to be fairly accurate, and on utilizes an iterative relaxation matrix method called MARDIGRAS (matrix analysis of relaxation for discerning the geometry of an aqueous structure), developed in this laboratory. An R factor for evaluating fit between experimental and calculated 2D NOE intensities is proposed

  15. ELECTROPHORETIC MOBILITY OF MYCOBACTERIUM AVIUM COMPLEX ORGANISMS

    Science.gov (United States)

    The electrophoretic mobilities (EPMs) of thirty Mycobacterium avium Complex (MAC) organisms were measured. The EPMs of fifteen clinical isolates ranged from -1.9 to -5.0 µm cm V-1s-1, and the EPMs of fifteen environmental isolates ranged from -1...

  16. Extracting information from two-dimensional electrophoresis gels by partial least squares regression

    DEFF Research Database (Denmark)

    Jessen, Flemming; Lametsch, R.; Bendixen, E.

    2002-01-01

    of all proteins/spots in the gels. In the present study it is demonstrated how information can be extracted by multivariate data analysis. The strategy is based on partial least squares regression followed by variable selection to find proteins that individually or in combination with other proteins vary......Two-dimensional gel electrophoresis (2-DE) produces large amounts of data and extraction of relevant information from these data demands a cautious and time consuming process of spot pattern matching between gels. The classical approach of data analysis is to detect protein markers that appear...... or disappear depending on the experimental conditions. Such biomarkers are found by comparing the relative volumes of individual spots in the individual gels. Multivariate statistical analysis and modelling of 2-DE data for comparison and classification is an alternative approach utilising the combination...

  17. The jellyfish and its polyp: a comparative study of gene expression monitored by the protein patterns using two-dimensional gels with double-label autoradiography

    International Nuclear Information System (INIS)

    Bally, Andreas; Schmid, Volker

    1988-01-01

    The life cycle of Podocoryne carnea (Coelenterata. Anthomedusae) shows several distinct stages which differ considerably in terms of their ecology, morphology, cellular composition and ultra structure. Using two-dimensional gel electrophoresis and a new method of double-label autoradiography, we show here for the first time for metagenic hydrozoans that only minor differences in gene expression exist between the various life cycle stages. Our results demonstrate the high resolution power of these techniques and show that the different life stages of P. carnea remain rather similar on the protein level (author)

  18. Multi-perspective views of students’ difficulties with one-dimensional vector and two-dimensional vector

    Science.gov (United States)

    Fauzi, Ahmad; Ratna Kawuri, Kunthi; Pratiwi, Retno

    2017-01-01

    Researchers of students’ conceptual change usually collects data from written tests and interviews. Moreover, reports of conceptual change often simply refer to changes in concepts, such as on a test, without any identification of the learning processes that have taken place. Research has shown that students have difficulties with vectors in university introductory physics courses and high school physics courses. In this study, we intended to explore students’ understanding of one-dimensional and two-dimensional vector in multi perspective views. In this research, we explore students’ understanding through test perspective and interviews perspective. Our research study adopted the mixed-methodology design. The participants of this research were sixty students of third semester of physics education department. The data of this research were collected by testand interviews. In this study, we divided the students’ understanding of one-dimensional vector and two-dimensional vector in two categories, namely vector skills of the addition of one-dimensionaland two-dimensional vector and the relation between vector skills and conceptual understanding. From the investigation, only 44% of students provided correct answer for vector skills of the addition of one-dimensional and two-dimensional vector and only 27% students provided correct answer for the relation between vector skills and conceptual understanding.

  19. Optimizing separations in online comprehensive two-dimensional liquid chromatography.

    Science.gov (United States)

    Pirok, Bob W J; Gargano, Andrea F G; Schoenmakers, Peter J

    2018-01-01

    Online comprehensive two-dimensional liquid chromatography has become an attractive option for the analysis of complex nonvolatile samples found in various fields (e.g. environmental studies, food, life, and polymer sciences). Two-dimensional liquid chromatography complements the highly popular hyphenated systems that combine liquid chromatography with mass spectrometry. Two-dimensional liquid chromatography is also applied to the analysis of samples that are not compatible with mass spectrometry (e.g. high-molecular-weight polymers), providing important information on the distribution of the sample components along chemical dimensions (molecular weight, charge, lipophilicity, stereochemistry, etc.). Also, in comparison with conventional one-dimensional liquid chromatography, two-dimensional liquid chromatography provides a greater separation power (peak capacity). Because of the additional selectivity and higher peak capacity, the combination of two-dimensional liquid chromatography with mass spectrometry allows for simpler mixtures of compounds to be introduced in the ion source at any given time, improving quantitative analysis by reducing matrix effects. In this review, we summarize the rationale and principles of two-dimensional liquid chromatography experiments, describe advantages and disadvantages of combining different selectivities and discuss strategies to improve the quality of two-dimensional liquid chromatography separations. © 2017 The Authors. Journal of Separation Science published by WILEY-VCH Verlag GmbH & Co. KGaA.

  20. Two-dimensional liquid chromatography

    DEFF Research Database (Denmark)

    Græsbøll, Rune

    -dimensional separation space. Optimization of gradients in online RP×RP is more difficult than in normal HPLC as a result of the increased number of parameters and their influence on each other. Modeling the coverage of the compounds across the two-dimensional chromatogram as a result of a change in gradients could...... be used for optimization purposes, and reduce the time spend on optimization. In this thesis (chapter 6), and manuscript B, a measure of the coverage of the compounds in the twodimensional separation space is defined. It is then shown that this measure can be modeled for changes in the gradient in both...

  1. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants

    International Nuclear Information System (INIS)

    Höhn, Sarah; Braem, Annabel; Neirinck, Bram; Virtanen, Sannakaisa

    2017-01-01

    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO 2 passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. - Highlights: • Alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin was investigated on Ti6Al4V. • The surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests at pH 7 and pH 5. • The analysis showed an increased adsorption of amino acids (DMEM) and proteins (DMEM + FCS). • BSA was shown to prevent dissolution of the β-phase, limiting metal ion release and increase of corrosion resistance. • Ratios calculated by means of ToF-SIMS show that the protein will have different orientations during adsorption.

  2. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants

    Energy Technology Data Exchange (ETDEWEB)

    Höhn, Sarah, E-mail: sarah.hoehn@fau.de [Institute for Surface Science and Corrosion, Dept. of Mat. Science, University of Erlangen-Nürnberg, 91058 Erlangen, Germany. (Germany); Braem, Annabel, E-mail: annabel.braem@kuleuven.be [KU Leuven Department of Materials Engineering, Kasteelpark Arenberg 44, Box 2450, 3001 Leuven (Belgium); Neirinck, Bram, E-mail: bram.neirinck@3DSystems.com [KU Leuven Department of Materials Engineering, Kasteelpark Arenberg 44, Box 2450, 3001 Leuven (Belgium); Virtanen, Sannakaisa, E-mail: virtanen@ww.uni-erlangen.de [Institute for Surface Science and Corrosion, Dept. of Mat. Science, University of Erlangen-Nürnberg, 91058 Erlangen, Germany. (Germany)

    2017-04-01

    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO{sub 2} passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. - Highlights: • Alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin was investigated on Ti6Al4V. • The surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests at pH 7 and pH 5. • The analysis showed an increased adsorption of amino acids (DMEM) and proteins (DMEM + FCS). • BSA was shown to prevent dissolution of the β-phase, limiting metal ion release and increase of corrosion resistance. • Ratios calculated by means of ToF-SIMS show that the protein will have different orientations during adsorption.

  3. Two-dimensional simulation of sintering process

    International Nuclear Information System (INIS)

    Vasconcelos, Vanderley de; Pinto, Lucio Carlos Martins; Vasconcelos, Wander L.

    1996-01-01

    The results of two-dimensional simulations are directly applied to systems in which one of the dimensions is much smaller than the others, and to sections of three dimensional models. Moreover, these simulations are the first step of the analysis of more complex three-dimensional systems. In this work, two basic features of the sintering process are studied: the types of particle size distributions related to the powder production processes and the evolution of geometric parameters of the resultant microstructures during the solid-state sintering. Random packing of equal spheres is considered in the sintering simulation. The packing algorithm does not take into account the interactive forces between the particles. The used sintering algorithm causes the densification of the particle set. (author)

  4. Two-dimensional patterning of thin coatings for the control of tissue outgrowth

    DEFF Research Database (Denmark)

    Thissen, H.; Johnson, G.; Hartley, P.G.

    2006-01-01

    were used to provide evidence of successful surface modifications. Adsorption of the extracellular matrix protein collagen I followed by tissue outgrowth experiments with bovine corneal epithelial tissue for up to 21 days showed that two-dimensional control over tissue outgrowth is achievable with our......Control of the precise location and extent of cellular attachment and proliferation, and of tissue outgrowth is important in a number of biomedical applications, including biomaterials and tissue engineered medical devices. Here we describe a method to control and direct the location and define...... boundaries of tissue growth on surfaces in two dimensions. The method relies on the generation of a spatially defined surface chemistry comprising protein adsorbing and non-adsorbing areas that allow control over the adsorption of cell-adhesive glycoproteins. Surface modification was carried out...

  5. Chaotic dynamics in two-dimensional noninvertible maps

    CERN Document Server

    Mira, Christian; Cathala, Jean-Claude; Gardini, Laura

    1996-01-01

    This book is essentially devoted to complex properties (Phase plane structure and bifurcations) of two-dimensional noninvertible maps, i.e. maps having either a non-unique inverse, or no real inverse, according to the plane point. They constitute models of sets of discrete dynamical systems encountered in Engineering (Control, Signal Processing, Electronics), Physics, Economics, Life Sciences. Compared to the studies made in the one-dimensional case, the two-dimensional situation remained a long time in an underdeveloped state. It is only since these last years that the interest for this resea

  6. Application of a method for comparing one-dimensional and two-dimensional models of a ground-water flow system

    International Nuclear Information System (INIS)

    Naymik, T.G.

    1978-01-01

    To evaluate the inability of a one-dimensional ground-water model to interact continuously with surrounding hydraulic head gradients, simulations using one-dimensional and two-dimensional ground-water flow models were compared. This approach used two types of models: flow-conserving one-and-two dimensional models, and one-dimensional and two-dimensional models designed to yield two-dimensional solutions. The hydraulic conductivities of controlling features were varied and model comparison was based on the travel times of marker particles. The solutions within each of the two model types compare reasonably well, but a three-dimensional solution is required to quantify the comparison

  7. Optimized set of two-dimensional experiments for fast sequential assignment, secondary structure determination, and backbone fold validation of 13C/15N-labelled proteins

    International Nuclear Information System (INIS)

    Bersch, Beate; Rossy, Emmanuel; Coves, Jacques; Brutscher, Bernhard

    2003-01-01

    NMR experiments are presented which allow backbone resonance assignment, secondary structure identification, and in favorable cases also molecular fold topology determination from a series of two-dimensional 1 H- 15 N HSQC-like spectra. The 1 H- 15 N correlation peaks are frequency shifted by an amount ± ω X along the 15 N dimension, where ω X is the C α , C β , or H α frequency of the same or the preceding residue. Because of the low dimensionality (2D) of the experiments, high-resolution spectra are obtained in a short overall experimental time. The whole series of seven experiments can be performed in typically less than one day. This approach significantly reduces experimental time when compared to the standard 3D-based methods. The here presented methodology is thus especially appealing in the context of high-throughput NMR studies of protein structure, dynamics or molecular interfaces

  8. Two-dimensional analytic weighting functions for limb scattering

    Science.gov (United States)

    Zawada, D. J.; Bourassa, A. E.; Degenstein, D. A.

    2017-10-01

    Through the inversion of limb scatter measurements it is possible to obtain vertical profiles of trace species in the atmosphere. Many of these inversion methods require what is often referred to as weighting functions, or derivatives of the radiance with respect to concentrations of trace species in the atmosphere. Several radiative transfer models have implemented analytic methods to calculate weighting functions, alleviating the computational burden of traditional numerical perturbation methods. Here we describe the implementation of analytic two-dimensional weighting functions, where derivatives are calculated relative to atmospheric constituents in a two-dimensional grid of altitude and angle along the line of sight direction, in the SASKTRAN-HR radiative transfer model. Two-dimensional weighting functions are required for two-dimensional inversions of limb scatter measurements. Examples are presented where the analytic two-dimensional weighting functions are calculated with an underlying one-dimensional atmosphere. It is shown that the analytic weighting functions are more accurate than ones calculated with a single scatter approximation, and are orders of magnitude faster than a typical perturbation method. Evidence is presented that weighting functions for stratospheric aerosols calculated under a single scatter approximation may not be suitable for use in retrieval algorithms under solar backscatter conditions.

  9. Uniform and selective deuteration in two-dimensional NMR of proteins

    International Nuclear Information System (INIS)

    LeMaster, D.M.

    1990-01-01

    This paper reports on the practicality of isotopic labeling, particularly deuteration, that has received considerable impetus from advances in molecular biology, which have allowed ready production of NMR quantities of labeled proteins. Protein expression in Escherichia coli allows use of the considerable metabolic genetics known for the organism in shaping the biosynthetic process to meet the labeling demands of the NMR experiments. In addition to deuteration's common use in spectral assignment problems, it also offers considerable potential for enhancing the quality of the nuclear Overhauser effect (NOE) distance and dihedral angle constraints used for solution structural analysis of proteins. Recent reviews emphasize the sample preparation and spectral benefits of protein deuteration

  10. From image processing to classification: IV. Classification of electrophoretic patterns by neural networks and statistical methods enable quality assessment of wheat varieties for breadmaking

    DEFF Research Database (Denmark)

    Jensen, Kirsten; Kesmir, Can; Søndergaard, Ib

    1996-01-01

    The end-use quality of products made from doughs consisting of wheat flour and water is often dependent upon the storage (gluten) proteins of the grain endosperm. Today the electrophoretic patterns of the high molecular weight (HMW) glutenin subunits are used for quality selections in wheat breed...

  11. Electrophoretic deposition of composite hydroxyapatite-chitosan coatings

    International Nuclear Information System (INIS)

    Pang Xin; Zhitomirsky, Igor

    2007-01-01

    Cathodic electrophoretic deposition has been utilized for the fabrication of composite hydroxyapatite-chitosan coatings on 316L stainless steel substrates. The addition of chitosan to the hydroxyapatite suspensions promoted the electrophoretic deposition of the hydroxyapatite nanoparticles and resulted in the formation of composite coatings. The obtained coatings were investigated by X-ray diffraction, thermogravimetric and differential thermal analysis, scanning and transmission electron microscopy, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy. It was shown that the deposit composition can be changed by a variation of the chitosan or hydroxyapatite concentration in the solutions. Experimental conditions were developed for the fabrication of hydroxyapatite-chitosan nanocomposites containing 40.9-89.8 wt.% hydroxyapatite. The method enabled the formation of adherent and uniform coatings of thicknesses up to 60 μm. X-ray studies revealed that the preferred orientation of the hydroxyapatite nanoparticles in the chitosan matrix increases with decreasing hydroxyapatite content in the composite coatings. The obtained coatings provided the corrosion protection for the 316L stainless steel substrates

  12. Depth-enhanced three-dimensional-two-dimensional convertible display based on modified integral imaging.

    Science.gov (United States)

    Park, Jae-Hyeung; Kim, Hak-Rin; Kim, Yunhee; Kim, Joohwan; Hong, Jisoo; Lee, Sin-Doo; Lee, Byoungho

    2004-12-01

    A depth-enhanced three-dimensional-two-dimensional convertible display that uses a polymer-dispersed liquid crystal based on the principle of integral imaging is proposed. In the proposed method, a lens array is located behind a transmission-type display panel to form an array of point-light sources, and a polymer-dispersed liquid crystal is electrically controlled to pass or to scatter light coming from these point-light sources. Therefore, three-dimensional-two-dimensional conversion is accomplished electrically without any mechanical movement. Moreover, the nonimaging structure of the proposed method increases the expressible depth range considerably. We explain the method of operation and present experimental results.

  13. Multivariate data analysis of two-dimensional gel electrophoresis protein patterns from few samples

    DEFF Research Database (Denmark)

    Jensen, Kristina Nedenskov; Jessen, Flemming; Jørgensen, Bo

    2008-01-01

    One application of 2D gel electrophoresis is to reveal differences in protein pattern between two or more groups of individuals, attributable to their group membership. Multivariate data analytical methods are useful in pinpointing the spots relevant for discrimination by focusing not only...... on single spot differences, but on the covariance structure between proteins. However, their outcome is dependent on data scaling, and they may fail in producing valid multivariate models due to the much higher number of "irrelevant" spots present in the gels. The case where only few gels are available...... and where the aim is to find as many as possible of the group-dependent proteins seems particularly difficult to handle. The present paper investigates such a case regarding the effect of scaling and of prefiltering by univariate nonparametric statistics on the selection of spots. Besides, a modified...

  14. Identification of proteins in a human pleural exudate using two-dimensional preparative liquid-phase electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Nilsson, C L; Puchades, M; Westman, A; Blennow, K; Davidsson, P

    1999-01-01

    Pleural effusion may occur in patients suffering from physical trauma or systemic disorders such as infection, inflammation, or cancer. In order to investigate proteins in a pleural exudate from a patient with severe pneumonia, we used a strategy that combined preparative two-dimensional liquid-phase electrophoresis (2-D LPE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and Western blotting. Preparative 2-D LPE is based on the same principles as analytical 2-D gel electrophoresis, except that the proteins remain in liquid phase during the entire procedure. In the first dimension, liquid-phase isoelectric focusing allows for the enrichment of proteins in liquid fractions. In the Rotofor cell, large volumes (up to 55 mL) and protein amounts (up to 1-2 g) can be loaded. Several low abundance proteins, cystatin C, haptoglobin, transthyretin, beta2-microglobulin, and transferrin, were detected after liquid-phase isoelectric focusing, through Western blotting analysis, in a pleural exudate (by definition, >25 g/L total protein). Direct MALDI-TOF-MS analysis of proteins in a Rotofor fraction is demonstrated as well. MALDI-TOF-MS analysis of a tryptic digest of a continuous elution sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) fraction confirmed the presence of cystatin C. By applying 2-D LPE, MALDI-TOF-MS, and Western blotting to the analysis of this pleural exudate, we were able to confirm the identity of proteins of potential diagnostic value. Our findings serve to illustrate the usefulness of this combination of methods in the analysis of pathological fluids.

  15. Comparison of protein patterns of xrs-5, a radiosensitive Chinese hamster ovary cell line, and CHO-K1, its radioresistant parent, using two-dimensional gel-electrophoresis

    International Nuclear Information System (INIS)

    Kramer, J.M.

    1991-01-01

    X-ray sensitive strains of Chinese hamster ovary cell lines have been used to analyze radiation repair mechanisms. One cell line, xrs-5, has been shown to be very sensitive to ionizing radiation and radical forming chemical mutagens. This sensitivity is thought to be a result a mutation in the DNA double strand break (DSB) repair mechanism, and its characterization has been a goal of several repair mechanism studies. Using two-dimensional gel electrophoresis, we have detected a protein (MW approximately 55KD) in the DNA/Nuclear Matrix (nucleoid) cell fraction of CHO-Kl cells that is absent in the nucleoid fraction of xrs-5. This protein is present, however, in both CHO-Kl and xrs-5 whole cell protein maps. To determine whether the 55KD protein is responsible for the radiosensitive and defective DSB repair phenotype of xrs-5 cells, studies are now underway to analyze revertants of xrs-5 that are proficient in DSB repair. Furthermore, an effort to sequence the protein in question is planned. 23 refs., 2 figs

  16. Insulin as a model to teach three-dimensional structure of proteins

    Directory of Open Access Journals (Sweden)

    João Batista Teixeira da Rocha

    2018-02-01

    Proteins are the most ubiquitous macromolecules found in the living cells and have innumerous physiological functions. Therefore, it is fundamental to build a solid knowledge about the proteins three dimensional structure to better understand the living state. The hierarchical structure of proteins is usually studied in the undergraduate discipline of Biochemistry. Here we described pedagogical interventions designed to increase the preservice teacher chemistry students’ knowledge about protein structure. The activities were made using alternative and cheap materials to encourage the application of these simple methodologies by the future teachers in the secondary school. From the primary structure of insulin chains, students had to construct a three-dimensional structure of insulin. After the activities, the students highlighted an improvement of their previous knowledge about proteins structure. The construction of a tridimensional model together with other activities seems to be an efficient way to promote the learning about the structure of proteins to undergraduate students. The methodology used was inexpensiveness and simple and it can be used both in the university and in the high-school.

  17. Functional inks and printing of two-dimensional materials.

    Science.gov (United States)

    Hu, Guohua; Kang, Joohoon; Ng, Leonard W T; Zhu, Xiaoxi; Howe, Richard C T; Jones, Christopher G; Hersam, Mark C; Hasan, Tawfique

    2018-05-08

    Graphene and related two-dimensional materials provide an ideal platform for next generation disruptive technologies and applications. Exploiting these solution-processed two-dimensional materials in printing can accelerate this development by allowing additive patterning on both rigid and conformable substrates for flexible device design and large-scale, high-speed, cost-effective manufacturing. In this review, we summarise the current progress on ink formulation of two-dimensional materials and the printable applications enabled by them. We also present our perspectives on their research and technological future prospects.

  18. One and two-dimensional electrophoresis of fast axonally-transported proteins in rat nerves following acrylamide and 2,5-hexanedione exposure

    International Nuclear Information System (INIS)

    Sickles, D.W.

    1990-01-01

    Transient and repeated deficiencies in protein delivery to the axon are observed following injections of acrylamide (ACR) and 2,5-hexanedione (2,5-HD) (Sickles DW, Neurotoxicology 10: 91;103, 1989; Neurosci Abstr 14:1219, 1988). We have furthered these studies by measuring the effects of single 50 mg/kg ACR and 4 nmole/kg 2,5-HD injections on the quantity of select fast-transported proteins. Proteins were radiolabelled with 3H-leucine injections of the DRG; 1 and 2 dimensional gels were used for separation of the sciatic nerve (9-45mm distal to the ganglion) homogenates. Scintillation counting demonstrated that transport of all proteins studied were affected by both toxicants. Some variation in effect was observed; a direct correlation between molecular weight (r=0.71) and original quantity of radiolabel (r=0.80) with the percent reduction in transport was observed. Some apparent increases in transport of certain proteins were observed on the 2D gels; but this may indicate a change in the isoelectric points of these transported proteins

  19. K-FIX: a computer program for transient, two-dimensional, two-fluid flow. THREED: an extension of the K-FIX code for three-dimensional calculations

    International Nuclear Information System (INIS)

    Rivard, W.C.; Torrey, M.D.

    1978-10-01

    The transient, two-dimensional, two-fluid code K-FIX has been extended to perform three-dimensional calculations. This capability is achieved by adding five modification sets of FORTRAN statements to the basic two-dimensional code. The modifications are listed and described, and a complete listing of the three-dimensional code is provided. Results of an example problem are provided for verification

  20. Characterisation of ribosomal proteins from HeLa and Krebs II mouse ascites tumor cells by different two-dimensional polyacrylamide gel electrophoresis techniques

    DEFF Research Database (Denmark)

    Issinger, O G; Beier, H

    1978-01-01

    Electrophoresis of ribosomal proteins according to Kaltschmidt and Wittmann, 1970a, b (pH 8.6/pH 4.5 urea system) yielded 29 proteins for the small subunits and 35 and 37 proteins for the large subunits of Krebs II ascites and HeLa ribosomes, respectively. Analysis of the proteins according...... to a modified technique by Mets and Bogorad (1974) (pH 4.5/pH 8.6 SDS system) revealed 28 and 29 proteins in the small subunits and 37 and 38 proteins in the large subunits of Krebs II ascites and HeLa ribosomes. The molecular weights of the individual proteins were determined by: 1. "three-dimensional" gel...... using the pH 4.5/pH 8.6 SDS system. The molecular weights Krebs II ascites and HeLa ribosomal proteins are compared with those obtained by other authors for different mammalian species....

  1. Effect of AOT Microemulsion Composition on the Hydrodynamic Diameter and Electrophoretic Mobility of Titanium Oxide Nanoparticles

    Science.gov (United States)

    Shaparenko, N. O.; Beketova, D. I.; Demidova, M. G.; Bulavchenko, A. I.

    2018-05-01

    The hydrodynamic diameter and electrophoretic mobility of titania nanoparticles in AOT microemulsions are studied depending on their water content (from 0 to 1.5 vol %), chloroform content in n-decane-chloroform mixture (from 0 to 30 vol %) and temperature (from 0 to 60°C). Considerable changes in diameter (from 20 to 400 nm) are detected upon adding water to the microemulsion. The electrophoretic mobility grows by 2-3 times upon adding chloroform, or as the temperature falls. The observed features allow us to halve the time of electrophoretic concentration for 140 nm TiO2 nanoparticles, and to concentrate 14 nm nanoparticles that do not exhibit electrophoretic mobility in the absence of chloroform.

  2. Two-dimensional critical phenomena

    International Nuclear Information System (INIS)

    Saleur, H.

    1987-09-01

    Two dimensional critical systems are studied using transformation to free fields and conformal invariance methods. The relations between the two approaches are also studied. The analytical results obtained generally depend on universality hypotheses or on renormalization group trajectories which are not established rigorously, so numerical verifications, mainly using the transfer matrix approach, are presented. The exact determination of critical exponents; the partition functions of critical models on toruses; and results as the critical point is approached are discussed [fr

  3. Phosphorylation of a specific cdk site in E2F-1 affects its electrophoretic mobility and promotes pRB-binding in vitro

    DEFF Research Database (Denmark)

    Peeper, D S; Keblusek, P; Helin, K

    1995-01-01

    of the retinoblastoma gene (pRB). We find that E2F-1 proteins are heterogeneously phosphorylated in insect cells, as a result of which they migrate as a doublet on SDS-polyacrylamide gels. This electrophoretic shift is shown to be dependent upon specific phosphorylation of E2F-1 on serine-375 (S375), near the p...

  4. Comparative two-dimensional gel analysis and microsequencing identifies gelsolin as one of the most prominent downregulated markers of transformed human fibroblast and epithelial cells

    DEFF Research Database (Denmark)

    Vandekerckhove, J; Bauw, G; Vancompernolle, K

    1990-01-01

    A systematic comparison of the protein synthesis patterns of cultured normal and transformed human fibroblasts and epithelial cells, using two-dimensional gel protein analysis combined with computerized imaging and data acquisition, identified a 90-kD protein (SSP 5714) as one of the most striking...... downregulated markers typical of the transformed state. Using the information stored in the comprehensive human cellular protein database, we found this protein strongly expressed in several fetal tissues and one of them, epidermis, served as a source for preparative two-dimensional gel electrophoresis. Partial...... and by coelectrophoresis with purified human gelsolin. These results suggest that an important regulatory protein of the microfilament system may play a role in defining the phenotype of transformed human fibroblast and epithelial cells in culture. Udgivelsesdato: 1990-Jul...

  5. Comparative two-dimensional gel analysis and microsequencing identifies gelsolin as one of the most prominent downregulated markers of transformed human fibroblast and epithelial cells

    DEFF Research Database (Denmark)

    Vandekerckhove, J; Bauw, G; Vancompernolle, K

    1990-01-01

    downregulated markers typical of the transformed state. Using the information stored in the comprehensive human cellular protein database, we found this protein strongly expressed in several fetal tissues and one of them, epidermis, served as a source for preparative two-dimensional gel electrophoresis. Partial......A systematic comparison of the protein synthesis patterns of cultured normal and transformed human fibroblasts and epithelial cells, using two-dimensional gel protein analysis combined with computerized imaging and data acquisition, identified a 90-kD protein (SSP 5714) as one of the most striking...... and by coelectrophoresis with purified human gelsolin. These results suggest that an important regulatory protein of the microfilament system may play a role in defining the phenotype of transformed human fibroblast and epithelial cells in culture. Udgivelsesdato: 1990-Jul...

  6. [Effect of freezing and cooking on the texture and electrophoretic pattern of the proteins of octopus arms (Octopus vulgaris)].

    Science.gov (United States)

    Reyes, Genara; Nirchio, Mauro; Bello, Rafael; Borderías, Javier

    2014-09-01

    Texture is the most valuable feature in cephalopods. Factors that mainly affect the texture of octopus are: freezing, scalding and cooking. The aim of this study was to assess the effect of freezing, scalding and length of cooking time on the texture and electrophoretic pattern of proteins of octopus arms. Octopuses were trapped near Margarita Island and carried with ice to the laboratory where they were packed and subjected to: a) freezing at -27 degrees C or at -20 degrees C b) scalding c) cooking for 25 min, 35 min or 45 min. Shear force was determined by Kramer cell on strips of octopus arms. SDS-PAGE was done according to the Laemmli method with 12% polyacrilamide gels. A sensory evaluation of the preference of texture was carried out using a hedonic scale of 7-points and a non-trained panel. Octopus texture was not affected by freezing temperature or scalding. Frozen octopus was softer after cooking than fresh. The longer the cooking time was, the softer the octopus was. Myosin heavy chain (MHC) was not significantly affected by scalding or cooking; however large aggregates heavier than MHC, new bands and loss of resolution of the bands appeared. Myosin and paramyosin bands were more affected by freezing prior to cooking.

  7. From image processing to classification: IV. Classification of electrophoretic patterns by neural networks and statistical methods enable quality assessment of wheat varieties for bread making

    DEFF Research Database (Denmark)

    Jensen, K.; Kesmir, Can; Søndergaard, Ib

    1996-01-01

    The end-use quality of products made from doughs consisting of wheat flour and water is often dependent upon the storage (gluten) proteins of the grain endosperm. Today the electrophoretic patterns of the high molecular weight (HMW) glutenin subunits are used for quality selections in wheat breed...

  8. Comparing the photophysics of the two forms of the Orange Carotenoid Protein using 2D electronic spectroscopy

    Directory of Open Access Journals (Sweden)

    Mathies R.A.

    2013-03-01

    Full Text Available Broadband two-dimensional electronic spectroscopy is applied to investigate the photophysics of the photoactive orange carotenoid protein, which is involved in nonphotochemical quenching in cyanobacteria. Differences in dynamics between the light and dark forms arise from the different structure of the carotenoid in the protein pocket, with consequences for the biological role of the two forms.

  9. Characterization of pH titration shifts for all the nonlabile proton resonances in a protein by two-dimensional NMR: The case of mouse epidermal growth factor

    International Nuclear Information System (INIS)

    Kohda, Daisuke; Sawada, Toshie; Inagaki, Fuyuhiko

    1991-01-01

    The pH titration shifts for all the nonlabile proton resonances in a 53-residue protein (mouse epidermal growth factor) were measured in the p 2 H range 1.5-9 with two-dimensional (2D) 1 H NMR. The 2D NMR pH titration experiment made it possible to determine the pK values for all the ionizable group which were titrated in the pH range 1.5-9 in the protein. The pK values of the nine ionizable groups (α-amino group, four Asp, two Glu, one His, and α-carboxyl group) were found to be near their normal values. The 2D titration experiment also provided a detailed description of the pH-dependent behavior of the proton chemical shifts and enabled us to characterize the pH-dependent changes of protein conformation. Analysis of the pH-dependent shifts of ca. 200 proton resonances offered evidence of conformational changes in slightly basic pH solution: The deprotonation of the N-terminal α-amino group induced a widespread conformational change over the β-sheet structure in the protein, while the effects of deprotonation of the His22 imidazole group were relatively localized. The authors found that the 2D NMR pH titration experiment is a powerful tool for investigating the structural and dynamic properties of proteins

  10. Two-dimensional capillary origami

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, N.D., E-mail: nbrubaker@math.arizona.edu; Lega, J., E-mail: lega@math.arizona.edu

    2016-01-08

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

  11. Two-dimensional capillary origami

    International Nuclear Information System (INIS)

    Brubaker, N.D.; Lega, J.

    2016-01-01

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

  12. Two-dimensional black holes and non-commutative spaces

    International Nuclear Information System (INIS)

    Sadeghi, J.

    2008-01-01

    We study the effects of non-commutative spaces on two-dimensional black hole. The event horizon of two-dimensional black hole is obtained in non-commutative space up to second order of perturbative calculations. A lower limit for the non-commutativity parameter is also obtained. The observer in that limit in contrast to commutative case see two horizon

  13. Two-Dimensional Raman Correlation Analysis of Diseased Esophagus in a Rat

    Science.gov (United States)

    Takanezawa, Sota; Morita, Shin-ichi; Maruyama, Atsushi; Murakami, Takurou N.; Kawashima, Norimichi; Endo, Hiroyuki; Iijima, Katsunori; Asakura, Tohru; Shimosegawa, Tooru; Sato, Hidetoshi

    2010-07-01

    Generalized two-dimensional (2D) Raman correlation analysis effectively distinguished a benign tumor from normal tissue. Line profiling Raman spectra of a rat esophagus, including a benign tumor, were measured and the generalized 2D synchronous and asynchronous spectra were calculated. In the autocorrelation area of the amide I band of proteins in the asynchronous map, a cross-like pattern was observed. A simulation study indicated that the pattern was caused by a sharp band component in the amide I band region. We considered that the benign tumor corresponded to the sharp component.

  14. Electrophoretic mobility patterns of collagen following laser welding

    Science.gov (United States)

    Bass, Lawrence S.; Moazami, Nader; Pocsidio, Joanne O.; Oz, Mehmet C.; LoGerfo, Paul; Treat, Michael R.

    1991-06-01

    Clinical application of laser vascular anastomosis in inhibited by a lack of understanding of its mechanism. Whether tissue fusion results from covalent or non-covalent bonding of collagen and other structural proteins is unknown. We compared electrophoretic mobility of collagen in laser treated and untreated specimens of rat tail tendon (>90% type I collagen) and rabbit aorta. Welding was performed, using tissue shrinkage as the clinical endpoint, using the 808 nm diode laser (power density 14 watts/cm2) and topical indocyanine green dye (max absorption 805 nm). Collagen was extracted with 8 M urea (denaturing), 0.5 M acetic acid (non-denaturing) and acetic acid/pepsin (cleaves non- helical protein). Mobility patterns on gel electrophoresis (SDS-PAGE) after urea or acetic acid extraction were identical in the lasered and control tendon and vessel (confirmed by optical densitometry), revealing no evidence of formation of novel covalent bonds. Alpha and beta band intensity was diminished in pepsin incubated lasered specimens compared with controls (optical density ratio 0.00 +/- 9 tendon, 0.65 +/- 0.12 aorta), indicating the presence of denatured collagen. With the laser parameters used, collagen is denatured without formation of covalent bonds, suggesting that non-covalent interaction between denatured collagen molecules may be responsible for the weld. Based on this mechanism, welding parameters can be chosen which produce collagen denaturation without cell death.

  15. Two-dimensional Navier-Stokes turbulence in bounded domains

    NARCIS (Netherlands)

    Clercx, H.J.H.; van Heijst, G.J.F.

    In this review we will discuss recent experimental and numerical results of quasi-two-dimensional decaying and forced Navier–Stokes turbulence in bounded domains. We will give a concise overview of developments in two-dimensional turbulence research, with emphasis on the progress made during the

  16. Two-dimensional Navier-Stokes turbulence in bounded domains

    NARCIS (Netherlands)

    Clercx, H.J.H.; Heijst, van G.J.F.

    2009-01-01

    In this review we will discuss recent experimental and numerical results of quasi-two-dimensional decaying and forced Navier–Stokes turbulence in bounded domains. We will give a concise overview of developments in two-dimensional turbulence research, with emphasis on the progress made during the

  17. Piezoelectricity in Two-Dimensional Materials

    KAUST Repository

    Wu, Tao; Zhang, Hua

    2015-01-01

    Powering up 2D materials: Recent experimental studies confirmed the existence of piezoelectricity - the conversion of mechanical stress into electricity - in two-dimensional single-layer MoS2 nanosheets. The results represent a milestone towards

  18. A novel method for the preparation of electrophoretic display microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiao-Meng; He, Jing; Liu, Sheng-Yun [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Chen, Jian-Feng [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing 100029 (China); Le, Yuan, E-mail: leyuan@mail.buct.edu.cn [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-07-01

    Highlights: • The electrophoretic display microcapsules were prepared by coaxial jet method aided by gas spray. • The positions of inner tube, liquid and gas flow rate of the process were investigated. • The size and shell thickness of the prepared microcapsules were controllable. • The prepared microcapsules had high coating ratio and exhibit reversible response to DC field. - Abstract: The narrow distributed electrophoretic display microcapsules containing electrophoretic ink were prepared using coaxial jet method aided by gas spray. Experimental results showed the size and shell thickness of the microcapsules could be controlled by adjusting flow rates of core and shell fluids as well as gas. The as-prepared white and red microcapsules, with average size of 100 and 200 μm respectively, had high coating ratio (above 90%) and exhibited reversible response to DC electric field. Compared with the approach of other microencapsulation methods, the new technique not only has a simple procedure but also provides a more effective way of size control. This novel method is expected to prepare microcapsules with potential application in the fields of electronic paper and other material science.

  19. Radio-iodinated surface proteins of electrophoretically separated rat lymphocytes

    International Nuclear Information System (INIS)

    Jilg, W.; Hannig, K.; Zeiller, K.

    1980-01-01

    Rat thymocytes and lymph node cells were separated into three T and one B subpopulation by means of free flow electrophoresis. The surface proteins of the separated cells were labelled by lactoperoxidase catalysed radioiodination. Most of the label was demonstrated to be at the cell surface. Although the surface protein patterns of the four lamphocyte subpopulations were rather similar, distinctive differences could be found. B cells had six labelled proteins which seemed to be absent in the other cells. In the T cell group three protein bands were identified, each with specificity for peripheral T cells, thymocytes and all T cells respectively. Four other proteins were found which showed quantitative differences between the four cell groups. (orig.) [de

  20. Field inversion gel electrophoretic analysis of Legionella pneumophila strains associated with nosocomial legionellosis in children.

    Science.gov (United States)

    Green, M; Wald, E R; Dashefsky, B; Barbadora, K; Wadowsky, R M

    1996-01-01

    Two nosocomial cases of Legionnaires' disease occurred in children. Legionella pneumophila serogroup 1 was isolated from both patients and 30 of 39 plumbing system sites in the hospital. The patient and hospital environmental isolates yielded identical field inversion gel electrophoretic patterns which differed from patterns observed with epidemiologically unrelated strains.

  1. Solution of the two-dimensional spectral factorization problem

    Science.gov (United States)

    Lawton, W. M.

    1985-01-01

    An approximation theorem is proven which solves a classic problem in two-dimensional (2-D) filter theory. The theorem shows that any continuous two-dimensional spectrum can be uniformly approximated by the squared modulus of a recursively stable finite trigonometric polynomial supported on a nonsymmetric half-plane.

  2. Development of Two-Dimensional NMR

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Development of Two-Dimensional NMR: Strucure Determination of Biomolecules in Solution. Anil Kumar. General Article Volume 20 Issue 11 November 2015 pp 995-1002 ...

  3. Chiral ionic liquids in chromatographic and electrophoretic separations.

    Science.gov (United States)

    Kapnissi-Christodoulou, Constantina P; Stavrou, Ioannis J; Mavroudi, Maria C

    2014-10-10

    This report provides an overview of the application of chiral ionic liquids (CILs) in separation technology, and particularly in capillary electrophoresis and both gas and liquid chromatography. There is a large number of CILs that have been synthesized and designed as chiral agents. However, only a few have successfully been applied in separation technology. Even though this application of CILs is still in its early stages, the scientific interest is increasing dramatically. This article is focused on the use of CILs as chiral selectors, background electrolyte additives, chiral ligands and chiral stationary phases in electrophoretic and chromatographic techniques. Different examples of CILs, which contain either a chiral cation, a chiral anion or both, are presented in this review article, and their major advantages along with their potential applications in chiral electrophoretic and chromatographic recognition are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. ONE-DIMENSIONAL AND TWO-DIMENSIONAL LEADERSHIP STYLES

    OpenAIRE

    Nikola Stefanović

    2007-01-01

    In order to motivate their group members to perform certain tasks, leaders use different leadership styles. These styles are based on leaders' backgrounds, knowledge, values, experiences, and expectations. The one-dimensional styles, used by many world leaders, are autocratic and democratic styles. These styles lie on the two opposite sides of the leadership spectrum. In order to precisely define the leadership styles on the spectrum between the autocratic leadership style and the democratic ...

  5. Infrared magneto-spectroscopy of two-dimensional and three-dimensional massless fermions: A comparison

    Energy Technology Data Exchange (ETDEWEB)

    Orlita, M., E-mail: milan.orlita@lncmi.cnrs.fr [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M. [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 38042 Grenoble (France); Basko, D. M. [LPMMC UMR 5493, Université Grenoble 1/CNRS, B.P. 166, 38042 Grenoble (France); Zholudev, M. S. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Teppe, F.; Knap, W. [Laboratoire Charles Coulomb (L2C), UMR CNRS 5221, GIS-TERALAB, Université Montpellier II, 34095 Montpellier (France); Gavrilenko, V. I. [Institute for Physics of Microstructures, RAS, Nizhny Novgorod GSP-105 603950 (Russian Federation); Mikhailov, N. N.; Dvoretskii, S. A. [A.V. Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Neugebauer, P. [Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany); Berger, C. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Institut Néel/CNRS-UJF BP 166, F-38042 Grenoble Cedex 9 (France); Heer, W. A. de [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2015-03-21

    Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.

  6. One-dimensional versus two-dimensional electronic states in vicinal surfaces

    International Nuclear Information System (INIS)

    Ortega, J E; Ruiz-Oses, M; Cordon, J; Mugarza, A; Kuntze, J; Schiller, F

    2005-01-01

    Vicinal surfaces with periodic arrays of steps are among the simplest lateral nanostructures. In particular, noble metal surfaces vicinal to the (1 1 1) plane are excellent test systems to explore the basic electronic properties in one-dimensional superlattices by means of angular photoemission. These surfaces are characterized by strong emissions from free-electron-like surface states that scatter at step edges. Thereby, the two-dimensional surface state displays superlattice band folding and, depending on the step lattice constant d, it splits into one-dimensional quantum well levels. Here we use high-resolution, angle-resolved photoemission to analyse surface states in a variety of samples, in trying to illustrate the changes in surface state bands as a function of d

  7. Quantitative two-dimensional gel electrophoresis analysis of human fibroblasts transformed by ras oncogenes.

    Science.gov (United States)

    Miller, M J; Maher, V M; McCormick, J J

    1992-11-01

    Quantitative two-dimensional gel electrophoresis was used to compare the cellular protein patterns of a normal foreskin-derived human fibroblasts cell line (LG1) and three immortal derivatives of LG1. One derivative, designated MSU-1.1 VO, was selected for its ability to grow in the absence of serum and is non-tumorigenic in athymic mice. The other two strains were selected for focus-formation following transfection with either Ha-ras or N-ras oncogenes and form high grade malignant tumors. Correspondence and cluster analysis provided a nonbiased estimate of the relative similarity of the different two-dimensional patterns. These techniques separated the gel patterns into three distinct classes: LG1, MSU-1.1 VO, and the ras transformed cell strains. The MSU-1.1 VO cells were more closely related to the parental LG1 than to the ras-transformed cells. The differences between the three classes were primarily quantitative in nature: 16% of the spots demonstrated statistically significant changes (P 2) in the rate of incorporation of radioactive amino acids. The patterns from the two ras-transformed cell strains were similar, and variations in the expression of proteins that occurred between the separate experiments obscured consistent differences between the Ha-ras and N-ras transformed cells. However, while only 9 out of 758 spots were classified as different (1%), correspondence analysis could consistently separate the two ras transformants. One of these spots was five times more intense in the Ha-ras transformed cells than the N-ras.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Densis. Densimetric representation of two-dimensional matrices

    International Nuclear Information System (INIS)

    Los Arcos Merino, J.M.

    1978-01-01

    Densis is a Fortran V program which allows off-line control of a Calcomp digital plotter, to represent a two-dimensional matrix of numerical elements in the form of a variable shading intensity map in two colours. Each matrix element is associated to a square of a grid which is traced over by lines whose number is a function of the element value according to a selected scale. Program features, subroutine structure and running instructions, are described. Some typical results, for gamma-gamma coincidence experimental data and a sampled two-dimensional function, are indicated. (author)

  9. Resonance fluorescence based two- and three-dimensional atom localization

    Science.gov (United States)

    Wahab, Abdul; Rahmatullah; Qamar, Sajid

    2016-06-01

    Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

  10. Toward two-dimensional search engines

    International Nuclear Information System (INIS)

    Ermann, L; Shepelyansky, D L; Chepelianskii, A D

    2012-01-01

    We study the statistical properties of various directed networks using ranking of their nodes based on the dominant vectors of the Google matrix known as PageRank and CheiRank. On average PageRank orders nodes proportionally to a number of ingoing links, while CheiRank orders nodes proportionally to a number of outgoing links. In this way, the ranking of nodes becomes two dimensional which paves the way for the development of two-dimensional search engines of a new type. Statistical properties of information flow on the PageRank–CheiRank plane are analyzed for networks of British, French and Italian universities, Wikipedia, Linux Kernel, gene regulation and other networks. A special emphasis is done for British universities networks using the large database publicly available in the UK. Methods of spam links control are also analyzed. (paper)

  11. Subjective figure reversal in two- and three-dimensional perceptual space.

    Science.gov (United States)

    Radilová, J; Radil-Weiss, T

    1984-08-01

    A permanently illuminated pattern of Mach's truncated pyramid can be perceived according to the experimental instruction given, either as a three-dimensional reversible figure with spontaneously changing convex and concave interpretation (in one experiment), or as a two-dimensional reversible figure-ground pattern (in another experiment). The reversal rate was about twice as slow, without the subjects being aware of it, if it was perceived as a three-dimensional figure compared to the situation when it was perceived as two-dimensional. It may be hypothetized that in the three-dimensional case, the process of perception requires more sequential steps than in the two-dimensional one.

  12. Determination and optimization of the ζ potential in boron electrophoretic deposition on aluminium substrates

    International Nuclear Information System (INIS)

    Oliveira Sampa, M.H. de; Vinhas, L.A.; Pino, E.S.

    1991-05-01

    In this work we present an introduction of the electrophoretic process followed by a detailed experimental treatment of the technique used in the determination and optimization of the ζ-potential, mainly as a function of the electrolyte concentration, in a high purity boron electrophoretics deposition on aluminium substrates used as electrodes in neutron detectors. (author)

  13. Protein-Based Three-Dimensional Memories and Associative Processors

    Science.gov (United States)

    Birge, Robert

    2008-03-01

    The field of bioelectronics has benefited from the fact that nature has often solved problems of a similar nature to those which must be solved to create molecular electronic or photonic devices that operate with efficiency and reliability. Retinal proteins show great promise in bioelectronic devices because they operate with high efficiency (˜0.65%), high cyclicity (>10^7), operate over an extended wavelength range (360 -- 630 nm) and can convert light into changes in voltage, pH, absorption or refractive index. This talk will focus on a retinal protein called bacteriorhodopsin, the proton pump of the organism Halobacterium salinarum. Two memories based on this protein will be described. The first is an optical three-dimensional memory. This memory stores information using volume elements (voxels), and provides as much as a thousand-fold improvement in effective capacity over current technology. A unique branching reaction of a variant of bacteriorhodopsin is used to turn each protein into an optically addressed latched AND gate. Although three working prototypes have been developed, a number of cost/performance and architectural issues must be resolved prior to commercialization. The major issue is that the native protein provides a very inefficient branching reaction. Genetic engineering has improved performance by nearly 500-fold, but a further order of magnitude improvement is needed. Protein-based holographic associative memories will also be discussed. The human brain stores and retrieves information via association, and human intelligence is intimately connected to the nature and enormous capacity of this associative search and retrieval process. To a first order approximation, creativity can be viewed as the association of two seemingly disparate concepts to form a totally new construct. Thus, artificial intelligence requires large scale associative memories. Current computer hardware does not provide an optimal environment for creating artificial

  14. Two multi-dimensional uncertainty relations

    International Nuclear Information System (INIS)

    Skala, L; Kapsa, V

    2008-01-01

    Two multi-dimensional uncertainty relations, one related to the probability density and the other one related to the probability density current, are derived and discussed. Both relations are stronger than the usual uncertainty relations for the coordinates and momentum

  15. Mechanical exfoliation of two-dimensional materials

    Science.gov (United States)

    Gao, Enlai; Lin, Shao-Zhen; Qin, Zhao; Buehler, Markus J.; Feng, Xi-Qiao; Xu, Zhiping

    2018-06-01

    Two-dimensional materials such as graphene and transition metal dichalcogenides have been identified and drawn much attention over the last few years for their unique structural and electronic properties. However, their rise begins only after these materials are successfully isolated from their layered assemblies or adhesive substrates into individual monolayers. Mechanical exfoliation and transfer are the most successful techniques to obtain high-quality single- or few-layer nanocrystals from their native multi-layer structures or their substrate for growth, which involves interfacial peeling and intralayer tearing processes that are controlled by material properties, geometry and the kinetics of exfoliation. This procedure is rationalized in this work through theoretical analysis and atomistic simulations. We propose a criterion to assess the feasibility for the exfoliation of two-dimensional sheets from an adhesive substrate without fracturing itself, and explore the effects of material and interface properties, as well as the geometrical, kinetic factors on the peeling behaviors and the torn morphology. This multi-scale approach elucidates the microscopic mechanism of the mechanical processes, offering predictive models and tools for the design of experimental procedures to obtain single- or few-layer two-dimensional materials and structures.

  16. [Identification and characterization of proteins from human bronchial secretion (author's transl)].

    Science.gov (United States)

    Laine, A; Hayem, A

    1976-03-01

    An analysis of bronchial mucus proteins was carried out by crossed immunoelectrophoresis. Before electrophoretic migration, sputum was treated with Ecteola-cellulose, which retains acid mucins. The proteins were then extracted by a phosphate/saline buffer pH 7.5. Crossed immunoelectrophoresis of the "bronchial extracts" was carried out with an anti-human serum: fifteen proteins were detected. Among them, IgA and protease inhibitiors play an important role in bronchial pathology. Bronchial extracts were also studied with immune serums against milk proteins, whole saliva and proteins of bronchial mucus. Bronchotransferrin, amylase and two esterases were characterized. Four other proteins were also detected with immune serums against bronchial mucus-proteins: their biological role is still unknown.

  17. Two-dimensional gel electrophoresis data in support of leaf comparative proteomics of two citrus species differing in boron-tolerance

    Directory of Open Access Journals (Sweden)

    Wen Sang

    2015-09-01

    Full Text Available Here, we provide the data from a comparative proteomics approach used to investigate the response of boron (B-tolerant ‘Xuegan’ (Citrus sinensis and B-intolerant ‘Sour pummelo’ (Citrus grandis leaves to B-toxicity. Using two-dimensional gel electrophoresis (2-DE technique, we identified 50 and 45 protein species with a fold change of more than 1.5 and a P-value of less than 0.05 from B-toxic C. sinensis and C. grandis leaves. These B-toxicity-responsive protein species were mainly involved in carbohydrate and energy metabolism, antioxidation and detoxification, stress responses, coenzyme biosynthesis, protein and amino acid metabolism, signal transduction, cell transport, cytoskeleton, nucleotide metabolism, and cell cycle and DNA processing. A detailed analysis of this data may be obtained from Sang et al. (J. Proteomics 114 (2015[1].

  18. Proteomic profiling of human pleural effusion using two-dimensional nano liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Tyan, Yu-Chang; Wu, Hsin-Yi; Lai, Wu-Wei; Su, Wu-Chou; Liao, Pao-Chi

    2005-01-01

    Pleural effusion, an accumulation of pleural fluid, contains proteins originated from plasma filtrate and, especially when tissues are damaged, parenchyma interstitial spaces of lungs and/or other organs. This study details protein profiles in human pleural effusion from 43 lung adenocarcinoma patients by a two-dimensional nano-high performance liquid chromatography electrospray ionization tandem mass spectrometry (2D nano-HPLC-ESI-MS/MS) system. The experimental results revealed the identification of 1415 unique proteins from human pleural effusion. Among these 124 proteins identified with higher confidence levels, some proteins have not been reported in plasma and may represent proteins specifically present in pleural effusion. These proteins are valuable for mass identification of differentially expressed proteins involved in proteomics database and screening biomarker to further study in human lung adenocarcinoma. The significance of the use of proteomics analysis of human pleural fluid for the search of new lung cancer marker proteins, and for their simultaneous display and analysis in patients suffering from lung disorders has been examined.

  19. Validation for chromatographic and electrophoretic methods

    OpenAIRE

    Ribani, Marcelo; Bottoli, Carla Beatriz Grespan; Collins, Carol H.; Jardim, Isabel Cristina Sales Fontes; Melo, Lúcio Flávio Costa

    2004-01-01

    The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the dif...

  20. Asymptotics for Two-dimensional Atoms

    DEFF Research Database (Denmark)

    Nam, Phan Thanh; Portmann, Fabian; Solovej, Jan Philip

    2012-01-01

    We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E^{\\TF}(\\lambd......We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E......^{\\TF}(\\lambda)$ is given by a Thomas-Fermi type variational problem and $c^{\\rm H}\\approx -2.2339$ is an explicit constant. We also show that the radius of a two-dimensional neutral atom is unbounded when $Z\\to \\infty$, which is contrary to the expected behavior of three-dimensional atoms....

  1. 21 CFR 864.7440 - Electrophoretic hemoglobin analysis system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrophoretic hemoglobin analysis system. 864.7440 Section 864.7440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864...

  2. Template-based electrophoretic deposition of perovskite PZT nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Nourmohammadi, A. [Solid Surfaces Analysis and Electron Microscopy Group, Institute of Physics, Chemnitz University of Technology, D-09126 Chemnitz (Germany); Semiconductors Department, Materials and Energy Research Center (MERC), 31779-83634 Karaj (Iran, Islamic Republic of); Bahrevar, M.A. [Semiconductors Department, Materials and Energy Research Center (MERC), 31779-83634 Karaj (Iran, Islamic Republic of)], E-mail: ma.bahrevar@yahoo.com; Hietschold, M. [Solid Surfaces Analysis and Electron Microscopy Group, Institute of Physics, Chemnitz University of Technology, D-09126 Chemnitz (Germany)

    2009-04-03

    Template-based electrophoretic deposition of perovskite lead zirconate titanate (PZT) nanotubes was achieved using anodic alumina (AA) membranes and sols, containing lead, zirconium and titanium precursors. The effect of various anodizing voltages on the size of the channels in the anodic alumina template was investigated. The prepared sol was driven into the channels under the influence of various electric fields and subsequently sintered at about 700 deg. C. The effects of the initial heating rates and the burn-out temperature on the phase evolution of the samples were studied and a modified firing process was employed. The effects of the electrophoretic voltage and the deposition time on the average wall thickness of the tubes were investigated. Scanning and transmission electron microscopy (SEM and TEM) revealed the efficiency of electrophoresis in the growth of lead zirconate titanate nanotubes in a close-packed array. The X-ray diffraction analyses indicated the presence of perovskite as the principal phase after a modified firing schedule.

  3. Spin dynamics in a two-dimensional quantum gas

    DEFF Research Database (Denmark)

    Pedersen, Poul Lindholm; Gajdacz, Miroslav; Deuretzbacher, Frank

    2014-01-01

    We have investigated spin dynamics in a two-dimensional quantum gas. Through spin-changing collisions, two clouds with opposite spin orientations are spontaneously created in a Bose-Einstein condensate. After ballistic expansion, both clouds acquire ring-shaped density distributions with superimp......We have investigated spin dynamics in a two-dimensional quantum gas. Through spin-changing collisions, two clouds with opposite spin orientations are spontaneously created in a Bose-Einstein condensate. After ballistic expansion, both clouds acquire ring-shaped density distributions...

  4. Application of design of experiment on electrophoretic deposition of ...

    Indian Academy of Sciences (India)

    Unknown

    Keywords. Coating; electrophoretic deposition; glass-ceramic; design of experiment. 1. Introduction ... other chemicals used were of laboratory reagent grade. ... changes from 7⋅0 to 9⋅5 that adversely affects the deposi- tion efficiency and ...

  5. Quantum oscillations in quasi-two-dimensional conductors

    CERN Document Server

    Galbova, O

    2002-01-01

    The electronic absorption of sound waves in quasi-two-dimensional conductors in strong magnetic fields, is investigated theoretically. A longitudinal acoustic wave, propagating along the normal n-> to the layer of quasi-two-dimensional conductor (k-> = left brace 0,0,k right brace; u-> = left brace 0,0,u right brace) in magnetic field (B-> = left brace 0, 0, B right brace), is considered. The quasiclassical approach for this geometry is of no interest, due to the absence of interaction between electromagnetic and acoustic waves. The problem is of interest in strong magnetic field when quantization of the charge carriers energy levels takes place. The quantum oscillations in the sound absorption coefficient, as a function of the magnetic field, are theoretically observed. The experimental study of the quantum oscillations in quasi-two-dimensional conductors makes it possible to solve the inverse problem of determining from experimental data the extrema closed sections of the Fermi surface by a plane p sub z = ...

  6. Electrophoretic separation of proteins in space

    Science.gov (United States)

    Brown, R. K.

    1976-01-01

    Commercially available and synthetic wide range and short range ampholytes used in the isoelectric focusing of proteins was analyzed by ion exchange chromatography. A pH gradient over the pH range 3.8 to 11.0 was used to elute the ampholytes from a column of a sulfonated polystyrene resin. The wide range ampholytes were resolved into some 60 to 70 ninhydrin positive components. The recovery obtained with the method was quantitative. Acid short range ampholytes have approximately 35 components which elute readily from the ion exchange resin. Basic short range ampholytes gave about 50 components, most of which eluted at alkaline pH.

  7. Third sound in one and two dimensional modulated structures

    International Nuclear Information System (INIS)

    Komuro, T.; Kawashima, H., Shirahama, K.; Kono, K.

    1996-01-01

    An experimental technique is developed to study acoustic transmission in one and two dimensional modulated structures by employing third sound of a superfluid helium film. In particular, the Penrose lattice, which is a two dimensional quasiperiodic structure, is studied. In two dimensions, the scattering of third sound is weaker than in one dimension. Nevertheless, the authors find that the transmission spectrum in the Penrose lattice, which is a two dimensional prototype of the quasicrystal, is observable if the helium film thickness is chosen around 5 atomic layers. The transmission spectra in the Penrose lattice are explained in terms of dynamical theory of diffraction

  8. Two-dimensional membranes in motion

    NARCIS (Netherlands)

    Davidovikj, D.

    2018-01-01

    This thesis revolves around nanomechanical membranes made of suspended two - dimensional materials. Chapters 1-3 give an introduction to the field of 2D-based nanomechanical devices together with an overview of the underlying physics and the measurementtools used in subsequent chapters. The research

  9. Comparison of first dimension IPG and NEPHGE techniques in two-dimensional gel electrophoresis experiment with cytosolic unfolded protein response in Saccharomyces cerevisiae

    Science.gov (United States)

    2013-01-01

    Background Two-dimensional gel electrophoresis (2DE) is one of the most popular methods in proteomics. Currently, most 2DE experiments are performed using immobilized pH gradient (IPG) in the first dimension; however, some laboratories still use carrier ampholytes-based isoelectric focusing technique. The aim of this study was to directly compare IPG-based and non-equilibrium pH gradient electrophoresis (NEPHGE)-based 2DE techniques by using the same samples and identical second dimension procedures. We have used commercially available Invitrogen ZOOM IPGRunner and WITAvision systems for IPG and NEPHGE, respectively. The effectiveness of IPG-based and NEPHGE-based 2DE methods was compared by analysing differential protein expression during cytosolic unfolded protein response (UPR-Cyto) in Saccharomyces cerevisiae. Results Protein loss during 2DE procedure was higher in IPG-based method, especially for basic (pI > 7) proteins. Overall reproducibility of spots was slightly better in NEPHGE-based method; however, there was a marked difference when evaluating basic and acidic protein spots. Using Coomassie staining, about half of detected basic protein spots were not reproducible by IPG-based 2DE, whereas NEPHGE-based method showed excellent reproducibility in the basic gel zone. The reproducibility of acidic proteins was similar in both methods. Absolute and relative volume variability of separate protein spots was comparable in both 2DE techniques. Regarding proteomic analysis of UPR-Cyto, the results exemplified parameters of general comparison of the methods. New highly basic protein Sis1p, overexpressed during UPR-Cyto stress, was identified by NEPHGE-based 2DE method, whereas IPG-based method showed unreliable results in the basic pI range and did not provide any new information on basic UPR-Cyto proteins. In the acidic range, the main UPR-Cyto proteins were detected and quantified by both methods. The drawback of NEPHGE-based 2DE method is its failure to

  10. Signal amelioration of electrophoretically deposited whole-cell biosensors using external electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Yoav, Hadar, E-mail: benyoav@post.tau.ac.il [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel-Aviv 69978 (Israel); Amzel, Tal [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel-Aviv 69978 (Israel); Sternheim, Marek [Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel-Aviv, 69978 (Israel); Belkin, Shimshon [Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Rubin, Adi [Department of Molecular Microbiology and Biotechnology, Faculty of Life Sciences, Tel Aviv University, Tel-Aviv, 69978 (Israel); Shacham-Diamand, Yosi [Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Tel-Aviv 69978 (Israel); Freeman, Amihay [Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel-Aviv, 69978 (Israel)

    2011-11-01

    Highlights: > We present an electrochemical whole-cell biochip that can apply electric fields. > We examine the integration of cells on a biochip using electrophoretic deposition. > The effect of electric fields on the whole-cell biosensor has been demonstrated. > Relatively short DC electric pulse improves the performance of whole-cell biosensors. > Prolonged AC electric fields deteriorated the whole-cell biosensor performance. - Abstract: This paper presents an integrated whole-cell biochip system where functioning cells are deposited on the solid micro-machined surfaces while specially designed indium tin oxide electrodes that can be used to apply controllable electric fields during various stages; for example during cell deposition. The electrodes can be used also for sensing currents associated with the sensing mechanisms of electrochemical whole-cell biosensors. In this work a new approach integrating live bacterial cells on a biochip using electrophoretic deposition is presented. The biomaterial deposition technique was characterized under various driving potentials and chamber configurations. An analytical model of the electrophoretic deposition kinetics was developed and presented here. The deposited biomass included genetically engineered bacterial cells that may respond to toxic material exposure by expressing proteins that react with specific analytes generating electrochemically active byproducts. In this study the effect of external electric fields on the whole-cell biochips has been successfully developed and tested. The research hypothesis was that by applying electric fields on bacterial whole-cells, their permeability to the penetration of external analytes can be increased. This effect was tested and the results are shown here. The effect of prolonged and short external electric fields on the bioelectrochemical signal generated by sessile bacterial whole-cells in response to the presence of toxins was studied. It was demonstrated that relatively

  11. Signal amelioration of electrophoretically deposited whole-cell biosensors using external electric fields

    International Nuclear Information System (INIS)

    Ben-Yoav, Hadar; Amzel, Tal; Sternheim, Marek; Belkin, Shimshon; Rubin, Adi; Shacham-Diamand, Yosi; Freeman, Amihay

    2011-01-01

    Highlights: → We present an electrochemical whole-cell biochip that can apply electric fields. → We examine the integration of cells on a biochip using electrophoretic deposition. → The effect of electric fields on the whole-cell biosensor has been demonstrated. → Relatively short DC electric pulse improves the performance of whole-cell biosensors. → Prolonged AC electric fields deteriorated the whole-cell biosensor performance. - Abstract: This paper presents an integrated whole-cell biochip system where functioning cells are deposited on the solid micro-machined surfaces while specially designed indium tin oxide electrodes that can be used to apply controllable electric fields during various stages; for example during cell deposition. The electrodes can be used also for sensing currents associated with the sensing mechanisms of electrochemical whole-cell biosensors. In this work a new approach integrating live bacterial cells on a biochip using electrophoretic deposition is presented. The biomaterial deposition technique was characterized under various driving potentials and chamber configurations. An analytical model of the electrophoretic deposition kinetics was developed and presented here. The deposited biomass included genetically engineered bacterial cells that may respond to toxic material exposure by expressing proteins that react with specific analytes generating electrochemically active byproducts. In this study the effect of external electric fields on the whole-cell biochips has been successfully developed and tested. The research hypothesis was that by applying electric fields on bacterial whole-cells, their permeability to the penetration of external analytes can be increased. This effect was tested and the results are shown here. The effect of prolonged and short external electric fields on the bioelectrochemical signal generated by sessile bacterial whole-cells in response to the presence of toxins was studied. It was demonstrated that

  12. Numerical calculation on a two-step subdiffusion behavior of lateral protein movement in plasma membranes

    Science.gov (United States)

    Sumi, Tomonari; Okumoto, Atsushi; Goto, Hitoshi; Sekino, Hideo

    2017-10-01

    A two-step subdiffusion behavior of lateral movement of transmembrane proteins in plasma membranes has been observed by using single-molecule experiments. A nested double-compartment model where large compartments are divided into several smaller ones has been proposed in order to explain this observation. These compartments are considered to be delimited by membrane-skeleton "fences" and membrane-protein "pickets" bound to the fences. We perform numerical simulations of a master equation using a simple two-dimensional lattice model to investigate the heterogeneous diffusion dynamics behavior of transmembrane proteins within plasma membranes. We show that the experimentally observed two-step subdiffusion process can be described using fence and picket models combined with decreased local diffusivity of transmembrane proteins in the vicinity of the pickets. This allows us to explain the two-step subdiffusion behavior without explicitly introducing nested double compartments.

  13. Properties of electrophoretically deposited single wall carbon nanotube films

    International Nuclear Information System (INIS)

    Lim, Junyoung; Jalali, Maryam; Campbell, Stephen A.

    2015-01-01

    This paper describes techniques for rapidly producing a carbon nanotube thin film by electrophoretic deposition at room temperature and determines the film mass density and electrical/mechanical properties of such films. The mechanism of electrophoretic deposition of thin layers is explained with experimental data. Also, film thickness is measured as a function of time, electrical field and suspension concentration. We use Rutherford backscattering spectroscopy to determine the film mass density. Films created in this manner have a resistivity of 2.14 × 10 −3 Ω·cm, a mass density that varies with thickness from 0.12 to 0.54 g/cm 3 , and a Young's modulus between 4.72 and 5.67 GPa. The latter was found to be independent of thickness from 77 to 134 nm. We also report on fabricating free-standing films by removing the metal seed layer under the CNT film, and selectively etching a sacrificial layer. This method could be extended to flexible photovoltaic devices or high frequency RF MEMS devices. - Highlights: • We explain the electrophoretic deposition process and mechanism of thin SWCNT film deposition. • Characterization of the SWCNT film properties including density, resistivity, transmittance, and Young's modulus. • The film density and resistivity are found to be a function of the film thickness. • Techniques developed to create free standing layers of SW-CNTs for flexible electronics and mechanical actuators

  14. Electrophoretic characterization of crude leaf proteins in ...

    African Journals Online (AJOL)

    Administrator

    ground in an eppendorf tube with 100 µl of lysis buffer. The mixtures were allowed to settle inside the eppendorf immersed in an ice bath for 1 h, and the supernatants were fractionated by. 7.5% SDS-PAGE (Laemmili, 1970). RESULTS AND DISCUSSION. Protein distribution patterns in three cultivars of. Lycopersicon and ...

  15. Incorrectness of conventional one-dimensional parallel thermal resistance circuit model for two-dimensional circular composite pipes

    International Nuclear Information System (INIS)

    Wong, K.-L.; Hsien, T.-L.; Chen, W.-L.; Yu, S.-J.

    2008-01-01

    This study is to prove that two-dimensional steady state heat transfer problems of composite circular pipes cannot be appropriately solved by the conventional one-dimensional parallel thermal resistance circuits (PTRC) model because its interface temperatures are not unique. Thus, the PTRC model is definitely different from its conventional recognized analogy, parallel electrical resistance circuits (PERC) model, which has unique node electric voltages. Two typical composite circular pipe examples are solved by CFD software, and the numerical results are compared with those obtained by the PTRC model. This shows that the PTRC model generates large error. Thus, this conventional model, introduced in most heat transfer text books, cannot be applied to two-dimensional composite circular pipes. On the contrary, an alternative one-dimensional separately series thermal resistance circuit (SSTRC) model is proposed and applied to a two-dimensional composite circular pipe with isothermal boundaries, and acceptable results are returned

  16. Cellular distribution, purification and electrophoretic properties of malate dehydrogenase in Trichuris ovis and inhibition by benzimidazoles and pyrimidine derivatives.

    Science.gov (United States)

    Sanchez-Moreno, M; Ortega, J E; Valero, A

    1989-12-01

    High levels of malate dehydrogenase were found in Trichuris ovis. Two molecular forms of the enzyme, of different cellular location and electrophoretic pattern, were isolated and purified. The activity of soluble malate dehydrogenase was greater than that of mitochondrial malate dehydrogenase. Both forms also displayed different electrophoretic profiles in comparison with purified extracts from goat (Capra hircus) liver. Substrate concentration directly affected enzyme activity. Host and parasite malate dehydrogenase activity were both inhibited by a series of benzimidazoles and pyrimidine-derived compounds, some of which markedly reduced parasite enzyme activity, but not host enzyme activity. Percentage inhibition by some pyrimidine derivatives was greater than that produced by benzimidazoles.

  17. Investigation of two different anoxia models by 2-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Wulff, Tune; Jessen, Flemming; Hoffmann, Else Kay

    2006-01-01

    anoxia obtained by NaN3 is a widely used model for simulating anoxia (Ossum et al., 2004). The effects of anoxia were studied by protein expression analysis using 2-dimensional gel electrophoresis followed by MS/MS. In this way we were able to separate more than 1500 protein spots with an apparent range...

  18. Chiral anomaly, fermionic determinant and two dimensional models

    International Nuclear Information System (INIS)

    Rego Monteiro, M.A. do.

    1985-01-01

    The chiral anomaly in random pair dimension is analysed. This anomaly is perturbatively calculated by dimensional regularization method. A new method for non-perturbative Jacobian calculation of a general chiral transformation, 1.e., finite and non-Abelian, is developed. This method is used for non-perturbative chiral anomaly calculation, as an alternative to bosonization of two-dimensional theories for massless fermions and to study the phenomenum of fermion number fractionalization. The fermionic determinant from two-dimensional quantum chromodynamics is also studied, and calculated, exactly, as in decoupling gauge as with out reference to a particular gauge. (M.C.K.) [pt

  19. A two-dimensional Zn coordination polymer with a three-dimensional supramolecular architecture

    Directory of Open Access Journals (Sweden)

    Fuhong Liu

    2017-10-01

    Full Text Available The title compound, poly[bis{μ2-4,4′-bis[(1,2,4-triazol-1-ylmethyl]biphenyl-κ2N4:N4′}bis(nitrato-κOzinc(II], [Zn(NO32(C18H16N62]n, is a two-dimensional zinc coordination polymer constructed from 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl units. It was synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The ZnII cation is located on an inversion centre and is coordinated by two O atoms from two symmetry-related nitrate groups and four N atoms from four symmetry-related 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligands, forming a distorted octahedral {ZnN4O2} coordination geometry. The linear 4,4′-bis[(1H-1,2,4-triazol-1-ylmethyl]-1,1′-biphenyl ligand links two ZnII cations, generating two-dimensional layers parallel to the crystallographic (132 plane. The parallel layers are connected by C—H...O, C—H...N, C—H...π and π–π stacking interactions, resulting in a three-dimensional supramolecular architecture.

  20. The Electrophoretic Mobility of Proteins near Surfaces

    Science.gov (United States)

    Ramasamy, Perumal; Singh, Avtar; Rafailovich, Miriam; Sokolov, Jonathan

    2004-03-01

    We have attempted to apply the methods developed for surface DNA electrophoresis (1) for proteomics. Droplets of FITC stained Abumin, Poly- L-Lysine, or Casein purchased from Sigma were deposited on glass cover slips. The droplets were then place in contact with a TBE buffer solution contained in a cell molded from PDMS. Pt electrodes were inserted into the cell and a voltage was a applied. The motion of the protein was then imaged with a Leica Confocal microscope as a function of buffer concentration, distance from the surface, and applied voltage. The mobilities were then compared with those of uncharged one micron florescent Polystyrene beads. References: 1)Henzel WJ, Watanabe C, Stults JT., !0 Protein Identification: The Origins of Peptide Mass Fingerprinting. !1 J. American Society for Mass Spectrometry. 14 (September 2003): 931-942 2)Mathesius U, Imin N, Natera SH, Rolfe BG., !0 Proteomics as a functional genomics tool. !1 Methods of Molecular Biology 236: 395-414. *Work supported in part by the NSF-MRSEC program

  1. Interaction of the host protein NbDnaJ with Potato virus X minus-strand stem-loop 1 RNA and capsid protein affects viral replication and movement.

    Science.gov (United States)

    Cho, Sang-Yun; Cho, Won Kyong; Sohn, Seong-Han; Kim, Kook-Hyung

    2012-01-06

    Plant viruses must interact with host cellular components to replicate and move from cell to cell. In the case of Potato virus X (PVX), it carries stem-loop 1 (SL1) RNA essential for viral replication and movement. Using two-dimensional electrophoresis northwestern blot analysis, we previously identified several host proteins that bind to SL1 RNA. Of those, we further characterized a DnaJ-like protein from Nicotiana benthamiana named NbDnaJ. An electrophoretic mobility shift assay confirmed that NbDnaJ binds only to SL1 minus-strand RNA, and bimolecular fluorescence complementation (BiFC) indicated that NbDnaJ interacts with PVX capsid protein (CP). Using a series of deletion mutants, the C-terminal region of NbDnaJ was found to be essential for the interaction with PVX CP. The expression of NbDnaJ significantly changed upon infection with different plant viruses such as PVX, Tobacco mosaic virus, and Cucumber mosaic virus, but varied depending on the viral species. In transient experiments, both PVX replication and movement were inhibited in plants that over-expressed NbDnaJ but accelerated in plants in which NbDnaJ was silenced. In summary, we suggest that the newly identified NbDnaJ plays a role in PVX replication and movement by interacting with SL1(-) RNA and PVX CP. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Electrophoretic deposition of zinc-substituted hydroxyapatite coatings.

    Science.gov (United States)

    Sun, Guangfei; Ma, Jun; Zhang, Shengmin

    2014-06-01

    Zinc-substituted hydroxyapatite nanoparticles synthesized by the co-precipitation method were used to coat stainless steel plates by electrophoretic deposition in n-butanol with triethanolamine as a dispersant. The effect of zinc concentration in the synthesis on the morphology and microstructure of coatings was investigated. It is found that the deposition current densities significantly increase with the increasing zinc concentration. The zinc-substituted hydroxyapatite coatings were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It is inferred that hydroxyapatite and triethanolamine predominate in the chemical composition of coatings. With the increasing Zn/Ca ratios, the contents of triethanolamine decrease in the final products. The triethanolamine can be burnt out by heat treatment. The tests of adhesive strength have confirmed good adhesion between the coatings and substrates. The formation of new apatite layer on the coatings has been observed after 7days of immersion in a simulated body fluid. In summary, the results show that dense, uniform zinc-substituted hydroxyapatite coatings are obtained by electrophoretic deposition when the Zn/Ca ratio reaches 5%. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Theory of the one- and two-dimensional electron gas

    International Nuclear Information System (INIS)

    Emery, V.J.

    1987-01-01

    Two topics are discussed: (1) the competition between 2k/sub F/ and 4k/sub F/ charge state waves in a one-dimensional electron gas and (2) a two-dimensional model of high T/sub c/ superconductivity in the oxides

  4. Role of adiponectin/phosphatidylinositol 3-kinase/protein kinase B ...

    African Journals Online (AJOL)

    2012-06-19

    Jun 19, 2012 ... Lysis buffer (SDS Lysis Buffer) was added to the samples overnight at 4°C. An equal amount of protein was loaded by the Coomassie method for protein quantification after electrophoretic separation. Protein was transferred onto polyvinylidene fluoride (PVDF) membranes. The transferred blot was blocked ...

  5. Lysine-Rich Proteins in High-Lysine Hordeum Vulgare Grain

    DEFF Research Database (Denmark)

    Ingversen, J.; Køie, B.

    1973-01-01

    The salt-soluble proteins in barley grain selected for high-lysine content (Hiproly, CI 7115 and the mutants 29 and 86) and of a control (Carlsberg II) with normal lysine content, contain identical major proteins as determined by MW and electrophoretic mobility. The concentration of a protein gro...

  6. The inaccuracy of conventional one-dimensional parallel thermal resistance circuit model for two-dimensional composite walls

    International Nuclear Information System (INIS)

    Wong, K.-L.; Hsien, T.-L.; Hsiao, M.-C.; Chen, W.-L.; Lin, K.-C.

    2008-01-01

    This investigation is to show that two-dimensional steady state heat transfer problems of composite walls should not be solved by the conventionally one-dimensional parallel thermal resistance circuits (PTRC) model because the interface temperatures are not unique. Thus PTRC model cannot be used like its conventional recognized analogy, parallel electrical resistance circuits (PERC) model which has the unique node electric voltage. Two typical composite wall examples, solved by CFD software, are used to demonstrate the incorrectness. The numerical results are compared with those obtained by PTRC model, and very large differences are observed between their results. This proves that the application of conventional heat transfer PTRC model to two-dimensional composite walls, introduced in most heat transfer text book, is totally incorrect. An alternative one-dimensional separately series thermal resistance circuit (SSTRC) model is proposed and applied to the two-dimensional composite walls with isothermal boundaries. Results with acceptable accuracy can be obtained by the new model

  7. Application of native agarose gel electrophoresis of serum proteins in veterinary diagnostics

    Directory of Open Access Journals (Sweden)

    Jania Bartosz

    2016-12-01

    Full Text Available Electrophoretic techniques, used to separate mixtures of electrically charged particles, are widely used in science. One of these techniques, native protein electrophoresis in an agarose gel, is applied in human and veterinary medicine. Changes in the proportions of individual protein fractions correspond to significant changes in the physiology of the body. Although the pattern obtained by electrophoretic separation rarely indicates a specific disease, it provides valuable information for the differential diagnosis. Decades of research on the types of patterns obtained in the case of particular diseases have led to the accumulation of substantial knowledge. The paper presents the available information on this topic. Serum protein electrophoresis is recommended in cases of increased levels of total protein in order to reveal the nature of the process. The basic information which can be obtained from electrophoretic separation includes the immune status of the organism. Both increased antigenic stimulation and immunodeficiency are clearly visible in electropherograms. Moreover, the level of heterogeneity of the corresponding protein fractions can help to distinguish between infectious diseases and cancer - multiple myeloma - the latter producing a homogeneous immunoglobulin fraction. Analysis of other protein fractions helps to detect or confirm an ongoing inflammatory process and provides information regarding liver function. Even when the concentration of total protein is within the reference range, this analysis can be recommended as a basic laboratory test.

  8. Two-dimensional fourier transform spectrometer

    Science.gov (United States)

    DeFlores, Lauren; Tokmakoff, Andrei

    2013-09-03

    The present invention relates to a system and methods for acquiring two-dimensional Fourier transform (2D FT) spectra. Overlap of a collinear pulse pair and probe induce a molecular response which is collected by spectral dispersion of the signal modulated probe beam. Simultaneous collection of the molecular response, pulse timing and characteristics permit real time phasing and rapid acquisition of spectra. Full spectra are acquired as a function of pulse pair timings and numerically transformed to achieve the full frequency-frequency spectrum. This method demonstrates the ability to acquire information on molecular dynamics, couplings and structure in a simple apparatus. Multi-dimensional methods can be used for diagnostic and analytical measurements in the biological, biomedical, and chemical fields.

  9. Topological aspect of disclinations in two-dimensional crystals

    International Nuclear Information System (INIS)

    Wei-Kai, Qi; Tao, Zhu; Yong, Chen; Ji-Rong, Ren

    2009-01-01

    By using topological current theory, this paper studies the inner topological structure of disclinations during the melting of two-dimensional systems. From two-dimensional elasticity theory, it finds that there are topological currents for topological defects in homogeneous equation. The evolution of disclinations is studied, and the branch conditions for generating, annihilating, crossing, splitting and merging of disclinations are given. (the physics of elementary particles and fields)

  10. Two-dimensional ranking of Wikipedia articles

    Science.gov (United States)

    Zhirov, A. O.; Zhirov, O. V.; Shepelyansky, D. L.

    2010-10-01

    The Library of Babel, described by Jorge Luis Borges, stores an enormous amount of information. The Library exists ab aeterno. Wikipedia, a free online encyclopaedia, becomes a modern analogue of such a Library. Information retrieval and ranking of Wikipedia articles become the challenge of modern society. While PageRank highlights very well known nodes with many ingoing links, CheiRank highlights very communicative nodes with many outgoing links. In this way the ranking becomes two-dimensional. Using CheiRank and PageRank we analyze the properties of two-dimensional ranking of all Wikipedia English articles and show that it gives their reliable classification with rich and nontrivial features. Detailed studies are done for countries, universities, personalities, physicists, chess players, Dow-Jones companies and other categories.

  11. Genetics of Two Storage Protein Variants in Barley

    DEFF Research Database (Denmark)

    Oram, R. N.; Doll, Hans; Køie, B.

    1975-01-01

    The Bomi and Sultan varieties have different co-dominant alleles at one locus on chromosome 5 controlling the electrophoretic pattern of one group of hordeins. This locus is hypostatic to the recessive allele in Risø mutant 1508, which suppresses the formation of these and some other hordeins...

  12. A two-dimensional proteome reference map of Herbaspirillum seropedicae proteins.

    Science.gov (United States)

    Chaves, Daniela Fojo Seixas; Ferrer, Pércio Pereira; de Souza, Emanuel Maltempi; Gruz, Leonardo Magalhães; Monteiro, Rose Adele; de Oliveira Pedrosa, Fábio

    2007-10-01

    Herbaspirillum seropedicae is an endophytic diazotroph associated with economically important crops such as rice, sugarcane, and wheat. Here, we present a 2-D reference map for H. seropedicae. Using MALDI-TOF-MS we identified 205 spots representing 173 different proteins with a calculated average of 1.18 proteins/gene. Seventeen hypothetical or conserved hypothetical ORFs were shown to code for true gene products. These data will support the genome annotation process and provide a basis on which to undertake comparative proteomic studies.

  13. Finding two-dimensional peaks

    International Nuclear Information System (INIS)

    Silagadze, Z.K.

    2007-01-01

    Two-dimensional generalization of the original peak finding algorithm suggested earlier is given. The ideology of the algorithm emerged from the well-known quantum mechanical tunneling property which enables small bodies to penetrate through narrow potential barriers. We merge this 'quantum' ideology with the philosophy of Particle Swarm Optimization to get the global optimization algorithm which can be called Quantum Swarm Optimization. The functionality of the newborn algorithm is tested on some benchmark optimization problems

  14. Electrophoretic characterization of the Mammalian nuclear matrix proteome, nuclear envelope, nucleoli and covalently bound ADP-ribose polymers: potential applications to cancer.

    Science.gov (United States)

    Aranda, Xavier G; Racho, Ronald G; Pacheco-Rodríguez, Gustavo; Alvarez-González, Rafael

    2014-01-01

    Nucleic acid metabolism is biochemically compartmentalized to the nucleus. Thus, it is necessary to define the proteome of the various macromolecular structures within this organelle. We isolated the nuclear matrix (NM) fraction from rat liver by sequential centrifugation steps at 13,000 rpm, staggered between endogenous nuclease treatment for 2 h at 37°C, followed by high-salt (H.S.; 2.0 M NaCl) and non-ionic detergent extractions (0.1%- or 1.0% Triton X-100) to eliminate the bulk of chromosomal DNA/RNA, histone proteins and the nuclear envelope (NE). Integrity of the NM and NE structures was confirmed by electron microscopy. Next, we analyzed the NM proteome on a 20% polyacrylamide gel using the PhastSystem. We observed the absence of histone proteins and the characteristic presence of the lamins by Coomassie blue staining. By contrast, upon silver staining, following electrophoretic separation with a Tris-Borate-EDTA buffer, we observed the NM-associated nucleic RNA and protein-free ADP-ribose polymers. While polymers are found in much lower concentration than RNA in NM, they were purified by affinity chromatography on boronate resin prior to electrophoresis. We observed the electrophoretic resolution of free ADP-ribose chains (5-25 units) by silver staining. The significance of our observations to cancer studies and carcinogenesis is discussed. Copyright© 2014, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.

  15. Validation of an electrophoretic method to detect albuminuria in cats.

    Science.gov (United States)

    Ferlizza, Enea; Dondi, Francesco; Andreani, Giulia; Bucci, Diego; Archer, Joy; Isani, Gloria

    2017-08-01

    Objectives The aims of this study were to validate a semi-automated high-resolution electrophoretic technique to quantify urinary albumin in healthy and diseased cats, and to evaluate its diagnostic performance in cases of proteinuria and renal diseases. Methods Urine samples were collected from 88 cats (healthy; chronic kidney disease [CKD]; lower urinary tract disease [LUTD]; non-urinary tract diseases [OTHER]). Urine samples were routinely analysed and high-resolution electrophoresis (HRE) was performed. Within-assay and between-assay variability, linearity, accuracy, recovery and the lowest detectable and quantifiable bands were calculated. Receiver operating curve (ROC) analysis was also performed. Results All coefficients of variation were HRE allowed the visualisation of a faint band of albumin and a diffused band between alpha and beta zones in healthy cats, while profiles from diseased cats were variable. Albumin (mg/dl) and urine albumin:creatinine ratio (UAC) were significantly ( P HRE is an accurate and precise method that could be used to measure albuminuria in cats. UAC was useful to correctly classify proteinuria and to discriminate between healthy and diseased cats. HRE might also provide additional information on urine proteins with a profile of all proteins (albumin and globulins) to aid clinicians in the diagnosis of diseases characterised by proteinuria.

  16. Quantum Communication Through a Two-Dimensional Spin Network

    International Nuclear Information System (INIS)

    Wang Zhaoming; Gu Yongjian

    2012-01-01

    We investigate the state or entanglement transfer through a two-dimensional spin network. We show that for state transfer, better fidelity can be gained along the diagonal direction but for entanglement transfer, when the initial entanglement is created along the boundary, the concurrence is more inclined to propagate along the boundary. This behavior is produced by quantum mechanical interference and the communication quality depends on the precise size of the network. For some number of sites, the fidelity in a two-dimensional channel is higher than one-dimensional case. This is an important result for realizing quantum communication through high dimension spin chain networks.

  17. Two-dimensional wave propagation in layered periodic media

    KAUST Repository

    Quezada de Luna, Manuel

    2014-09-16

    We study two-dimensional wave propagation in materials whose properties vary periodically in one direction only. High order homogenization is carried out to derive a dispersive effective medium approximation. One-dimensional materials with constant impedance exhibit no effective dispersion. We show that a new kind of effective dispersion may arise in two dimensions, even in materials with constant impedance. This dispersion is a macroscopic effect of microscopic diffraction caused by spatial variation in the sound speed. We analyze this dispersive effect by using highorder homogenization to derive an anisotropic, dispersive effective medium. We generalize to two dimensions a homogenization approach that has been used previously for one-dimensional problems. Pseudospectral solutions of the effective medium equations agree to high accuracy with finite volume direct numerical simulations of the variable-coeffi cient equations.

  18. Modelling of oscillations in two-dimensional echo-spectra of the Fenna-Matthews-Olson complex

    International Nuclear Information System (INIS)

    Hein, Birgit; Kreisbeck, Christoph; Kramer, Tobias; Rodríguez, Mirta

    2012-01-01

    Recent experimental observations of time-dependent beatings in the two-dimensional echo-spectra of light-harvesting complexes at ambient temperatures have opened up the question of whether coherence and wave-like behaviour play a significant role in photosynthesis. We carry out a numerical study of the absorption and echo-spectra of the Fenna-Matthews-Olson (FMO) complex in Chlorobium tepidum and analyse the requirements in the theoretical model needed to reproduce beatings in the calculated spectra. The energy transfer in the FMO pigment-protein complex is theoretically described by an exciton Hamiltonian coupled to a phonon bath which accounts for the pigments' electronic and vibrational excitations, respectively. We use the hierarchical equations of motions method to treat the strong couplings in a non-perturbative way. We show that the oscillations in the two-dimensional echo-spectra persist in the presence of thermal noise and static disorder. (paper)

  19. Lorentz covariant tempered distributions in two-dimensional space-time

    International Nuclear Information System (INIS)

    Zinov'ev, Yu.M.

    1989-01-01

    The problem of describing Lorentz covariant distributions without any spectral condition has hitherto remained unsolved even for two-dimensional space-time. Attempts to solve this problem have already been made. Zharinov obtained an integral representation for the Laplace transform of Lorentz invariant distributions with support in the product of two-dimensional future light cones. However, this integral representation does not make it possible to obtain a complete description of the corresponding Lorentz invariant distributions. In this paper the author gives a complete description of Lorentz covariant distributions for two-dimensional space-time. No spectral conditions is assumed

  20. Solution-Based Processing and Applications of Two-Dimensional Heterostructures

    Science.gov (United States)

    Hersam, Mark

    Two-dimensional materials have emerged as promising candidates for next-generation electronics and optoelectronics, but advances in scalable nanomanufacturing are required to exploit this potential in real-world technology. This talk will explore methods for improving the uniformity of solution-processed two-dimensional materials with an eye toward realizing dispersions and inks that can be deposited into large-area thin-films. In particular, density gradient ultracentrifugation allows the solution-based isolation of graphene, boron nitride, montmorillonite, and transition metal dichalcogenides (e.g., MoS2, WS2, ReS2, MoSe2, WSe2) with homogeneous thickness down to the atomically thin limit. Similarly, two-dimensional black phosphorus is isolated in organic solvents or deoxygenated aqueous surfactant solutions with the resulting phosphorene nanosheets showing field-effect transistor mobilities and on/off ratios that are comparable to micromechanically exfoliated flakes. By adding cellulosic polymer stabilizers to these dispersions, the rheological properties can be tuned by orders of magnitude, thereby enabling two-dimensional material inks that are compatible with a range of additive manufacturing methods including inkjet, gravure, screen, and 3D printing. The resulting solution-processed two-dimensional heterostructures show promise in several device applications including photodiodes, anti-ambipolar transistors, gate-tunable memristors, and heterojunction photovoltaics.

  1. Electrophoresis forum '80

    International Nuclear Information System (INIS)

    Radola, B.J.

    1980-01-01

    In this volume the contributions of the electrophoresis meeting are presented in a short term form. The main topics are gel-electrophoresis, ultra thin film isoelectric focusing, one- and two-dimensional electrophoresis, electrophoretical separation techniques, electric focusing (for phorensic studies), substrate free and substrate electrophoresis. In the poster session of this meeting subjects such as (ultra) thin film isoelectric focusing, identification of radioactive proteins, labelling of cell surfaces, autoradiography and 3 H-labelled proteins. Separate abstracts were prepared for 4 papers in this report. (HK) [de

  2. Inter-layer Cooper pairing of two-dimensional electrons

    International Nuclear Information System (INIS)

    Inoue, Masahiro; Takemori, Tadashi; Yoshizaki, Ryozo; Sakudo, Tunetaro; Ohtaka, Kazuo

    1987-01-01

    The authors point out the possibility that the high transition temperatures of the recently discovered oxide superconductors are dominantly caused by the inter-layer Cooper pairing of two-dimensional electrons that are coupled through the exchange of three-dimensional phonons. (author)

  3. Two-dimensional capillary electrophoresis: capillary isoelectric focusing and capillary zone electrophoresis with laser-induced fluorescence detection

    Science.gov (United States)

    Dickerson, Jane A.; Ramsay, Lauren M.; Dada, Oluwatosin O.; Cermak, Nathan

    2011-01-01

    Capillary isoelectric focusing and capillary zone electrophoresis are coupled with laser-induced fluorescence detection to create an ultrasensitive two-dimensional separation method for proteins. In this method, two capillaries are joined through a buffer filled interface. Separate power supplies control the potential at the injection end of the first capillary and at the interface; the detector is held at ground potential. Proteins are labeled with the fluorogenic reagent Chromeo P503, which preserves the isoelectric point of the labeled protein. The labeled proteins were mixed with ampholytes and injected into the first dimension capillary. A focusing step was performed with the injection end of the capillary at high pH and the interface at low pH. To mobilize components, the interface was filled with a high pH buffer, which was compatible with the second dimension separation. A fraction was transferred to the second dimension capillary for separation. The process of fraction transfer and second dimension separation was repeated two dozen times. The separation produced a spot capacity of 125. PMID:20603830

  4. Optimal Padding for the Two-Dimensional Fast Fourier Transform

    Science.gov (United States)

    Dean, Bruce H.; Aronstein, David L.; Smith, Jeffrey S.

    2011-01-01

    One-dimensional Fast Fourier Transform (FFT) operations work fastest on grids whose size is divisible by a power of two. Because of this, padding grids (that are not already sized to a power of two) so that their size is the next highest power of two can speed up operations. While this works well for one-dimensional grids, it does not work well for two-dimensional grids. For a two-dimensional grid, there are certain pad sizes that work better than others. Therefore, the need exists to generalize a strategy for determining optimal pad sizes. There are three steps in the FFT algorithm. The first is to perform a one-dimensional transform on each row in the grid. The second step is to transpose the resulting matrix. The third step is to perform a one-dimensional transform on each row in the resulting grid. Steps one and three both benefit from padding the row to the next highest power of two, but the second step needs a novel approach. An algorithm was developed that struck a balance between optimizing the grid pad size with prime factors that are small (which are optimal for one-dimensional operations), and with prime factors that are large (which are optimal for two-dimensional operations). This algorithm optimizes based on average run times, and is not fine-tuned for any specific application. It increases the amount of times that processor-requested data is found in the set-associative processor cache. Cache retrievals are 4-10 times faster than conventional memory retrievals. The tested implementation of the algorithm resulted in faster execution times on all platforms tested, but with varying sized grids. This is because various computer architectures process commands differently. The test grid was 512 512. Using a 540 540 grid on a Pentium V processor, the code ran 30 percent faster. On a PowerPC, a 256x256 grid worked best. A Core2Duo computer preferred either a 1040x1040 (15 percent faster) or a 1008x1008 (30 percent faster) grid. There are many industries that

  5. Surface representations of two- and three-dimensional fluid flow topology

    Science.gov (United States)

    Helman, James L.; Hesselink, Lambertus

    1990-01-01

    We discuss our work using critical point analysis to generate representations of the vector field topology of numerical flow data sets. Critical points are located and characterized in a two-dimensional domain, which may be either a two-dimensional flow field or the tangential velocity field near a three-dimensional body. Tangent curves are then integrated out along the principal directions of certain classes of critical points. The points and curves are linked to form a skeleton representing the two-dimensional vector field topology. When generated from the tangential velocity field near a body in a three-dimensional flow, the skeleton includes the critical points and curves which provide a basis for analyzing the three-dimensional structure of the flow separation. The points along the separation curves in the skeleton are used to start tangent curve integrations to generate surfaces representing the topology of the associated flow separations.

  6. Survival rate of eukaryotic cells following electrophoretic nanoinjection.

    Science.gov (United States)

    Simonis, Matthias; Hübner, Wolfgang; Wilking, Alice; Huser, Thomas; Hennig, Simon

    2017-01-25

    Insertion of foreign molecules such as functionalized fluorescent probes, antibodies, or plasmid DNA to living cells requires overcoming the plasma membrane barrier without harming the cell during the staining process. Many techniques such as electroporation, lipofection or microinjection have been developed to overcome the cellular plasma membrane, but they all result in reduced cell viability. A novel approach is the injection of cells with a nanopipette and using electrophoretic forces for the delivery of molecules. The tip size of these pipettes is approximately ten times smaller than typical microinjection pipettes and rather than pressure pulses as delivery method, moderate DC electric fields are used to drive charged molecules out of the tip. Here, we show that this approach leads to a significantly higher survival rate of nanoinjected cells and that injection with nanopipettes has a significantly lower impact on the proliferation behavior of injected cells. Thus, we propose that injection with nanopipettes using electrophoretic delivery is an excellent alternative when working with valuable and rare living cells, such as primary cells or stem cells.

  7. Survival rate of eukaryotic cells following electrophoretic nanoinjection

    Science.gov (United States)

    Simonis, Matthias; Hübner, Wolfgang; Wilking, Alice; Huser, Thomas; Hennig, Simon

    2017-01-01

    Insertion of foreign molecules such as functionalized fluorescent probes, antibodies, or plasmid DNA to living cells requires overcoming the plasma membrane barrier without harming the cell during the staining process. Many techniques such as electroporation, lipofection or microinjection have been developed to overcome the cellular plasma membrane, but they all result in reduced cell viability. A novel approach is the injection of cells with a nanopipette and using electrophoretic forces for the delivery of molecules. The tip size of these pipettes is approximately ten times smaller than typical microinjection pipettes and rather than pressure pulses as delivery method, moderate DC electric fields are used to drive charged molecules out of the tip. Here, we show that this approach leads to a significantly higher survival rate of nanoinjected cells and that injection with nanopipettes has a significantly lower impact on the proliferation behavior of injected cells. Thus, we propose that injection with nanopipettes using electrophoretic delivery is an excellent alternative when working with valuable and rare living cells, such as primary cells or stem cells. PMID:28120926

  8. Electrophoretic separation techniques and their hyphenation to mass spectrometry in biological inorganic chemistry.

    Science.gov (United States)

    Holtkamp, Hannah; Grabmann, Gerlinde; Hartinger, Christian G

    2016-04-01

    Electrophoretic methods have been widely applied in research on the roles of metal complexes in biological systems. In particular, CE, often hyphenated to a sensitive MS detector, has provided valuable information on the modes of action of metal-based pharmaceuticals, and more recently new methods have been added to the electrophoretic toolbox. The range of applications continues to expand as a result of enhanced CE-to-MS interfacing, with sensitivity often at picomolar level, and evolved separation modes allowing for innovative sample analysis. This article is a followup to previous reviews about CE methods in metallodrug research (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis, 2007, 28, 3436-3446; Electrophoresis, 2012, 33, 622-634), also providing a comprehensive overview of metal species studied by electrophoretic methods hyphenated to MS. It highlights the latest CE developments, takes a sneak peek into gel electrophoresis, traces biomolecule labeling, and focuses on the importance of early-stage drug development. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Quasi-integrability and two-dimensional QCD

    International Nuclear Information System (INIS)

    Abdalla, E.; Mohayaee, R.

    1996-10-01

    The notion of integrability in two-dimensional QCD is discussed. We show that in spite of an infinite number of conserved charges, particle production is not entirely suppressed. This phenomenon, which we call quasi-integrability, is explained in terms of quantum corrections to the combined algebra of higher-conserved and spectrum-generating currents. We predict the qualitative form of particle production probabilities and verify that they are in agreement with numerical data. We also discuss four-dimensional self-dual Yang-Mills theory in the light of our results. (author). 25 refs, 4 figs, 1 tab

  10. Two-dimensional QCD in the Coulomb gauge

    International Nuclear Information System (INIS)

    Kalashnikova, Yu.S.; Nefed'ev, A.V.

    2002-01-01

    Various aspects of the 't Hooft model for two-dimensional QCD in the limit of infinite number of colours in the Coulomb gauge are discussed. The properties of mesonic excitations are studied, with special emphasis on the pion. Attention is paid to the dual role of the pion. which, while a genuine qq-bar state, is a Goldstone boson of two-dimensional QCD as well. In particular, the validity of the soft-pion theorems is demonstrated. It is shown that the Coulomb gauge is the most suitable choice for the study of hadronic observables involving pions [ru

  11. Sensitivity analysis explains quasi-one-dimensional current transport in two-dimensional materials

    DEFF Research Database (Denmark)

    Boll, Mads; Lotz, Mikkel Rønne; Hansen, Ole

    2014-01-01

    We demonstrate that the quasi-one-dimensional (1D) current transport, experimentally observed in graphene as measured by a collinear four-point probe in two electrode configurations A and B, can be interpreted using the sensitivity functions of the two electrode configurations (configurations...... A and B represents different pairs of electrodes chosen for current sources and potential measurements). The measured sheet resistance in a four-point probe measurement is averaged over an area determined by the sensitivity function. For a two-dimensional conductor, the sensitivity functions for electrode...... configurations A and B are different. But when the current is forced to flow through a percolation network, e.g., graphene with high density of extended defects, the two sensitivity functions become identical. This is equivalent to a four-point measurement on a line resistor, hence quasi-1D transport...

  12. Using electrophoretic mobility shift assays to measure equilibrium dissociation constants: GAL4-p53 binding DNA as a model system.

    Science.gov (United States)

    Heffler, Michael A; Walters, Ryan D; Kugel, Jennifer F

    2012-01-01

    An undergraduate biochemistry laboratory experiment is described that will teach students the practical and theoretical considerations for measuring the equilibrium dissociation constant (K(D) ) for a protein/DNA interaction using electrophoretic mobility shift assays (EMSAs). An EMSA monitors the migration of DNA through a native gel; the DNA migrates more slowly when bound to a protein. To determine a K(D) the amount of unbound and protein-bound DNA in the gel is measured as the protein concentration increases. By performing this experiment, students will be introduced to making affinity measurements and gain experience in performing quantitative EMSAs. The experiment describes measuring the K(D) for the interaction between the chimeric protein GAL4-p53 and its DNA recognition site; however, the techniques are adaptable to other DNA binding proteins. In addition, the basic experiment described can be easily expanded to include additional inquiry-driven experimentation. © 2012 by The International Union of Biochemistry and Molecular Biology. Copyright © 2012 Wiley Periodicals, Inc.

  13. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua

    International Nuclear Information System (INIS)

    Zhang, Weigang; Zhang, Gangsheng

    2015-01-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index. - Highlights: • A humidity sensitive two-dimensional tunable amorphous photonic structure • Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure. • This photonic structure may yield very useful template for artificial structures

  14. A humidity sensitive two-dimensional tunable amorphous photonic structure in the outer layer of bivalve ligament from Sunset Siliqua

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weigang, E-mail: abczwg15@163.com [College of Materials and Chemical Engineering, Chuzhou University, Chuzhou 239000 (China); Zhang, Gangsheng [College of Material Science and Technology, Guangxi University, Nanning 530004 (China)

    2015-07-01

    A humidity sensitive two-dimensional tunable amorphous photonic structure (2D TAPS) in the outer layer of bivalve ligament from Sunset Siliqua (OLLS) was reported in this paper. The structural color and microstructure of OLLS were investigated by reflection spectra and scanning electron microscopy, respectively. The results indicate that the reflection peak wavelength of the wet OLLS blue-shifts from 454 nm to 392 nm with the increasing of air drying time from 0 to 40 min, while the reflectivity decreases gradually and vanishes at last, relevant color changes from blue to black background color. The structural color in the OLLS is produced by a two-dimensional amorphous photonic structure consisting of aligned protein fibers, in which the diameter of protein fiber and the inter-fiber spacing are 101 ± 12 nm. Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure, and the regulation achieved through dynamically tuning the interaction between inter-fiber spacing and average refractive index. - Highlights: • A humidity sensitive two-dimensional tunable amorphous photonic structure • Water can reversibly tune the reflection peak wavelength and reflectivity of this photonic structure. • This photonic structure may yield very useful template for artificial structures.

  15. On-capillary sample cleanup method for the electrophoretic determination of carbohydrates in juice samples.

    Science.gov (United States)

    Morales-Cid, Gabriel; Simonet, Bartolomé M; Cárdenas, Soledad; Valcárcel, Miguel

    2007-05-01

    On many occasions, sample treatment is a critical step in electrophoretic analysis. As an alternative to batch procedures, in this work, a new strategy is presented with a view to develop an on-capillary sample cleanup method. This strategy is based on the partial filling of the capillary with carboxylated single-walled carbon nanotube (c-SWNT). The nanoparticles retain interferences from the matrix allowing the determination and quantification of carbohydrates (viz glucose, maltose and fructose). The precision of the method for the analysis of real samples ranged from 5.3 to 6.4%. The proposed method was compared with a method based on a batch filtration of the juice sample through diatomaceous earth and further electrophoretic determination. This method was also validated in this work. The RSD for this other method ranged from 5.1 to 6%. The results obtained by both methods were statistically comparable demonstrating the accuracy of the proposed methods and their effectiveness. Electrophoretic separation of carbohydrates was achieved using 200 mM borate solution as a buffer at pH 9.5 and applying 15 kV. During separation, the capillary temperature was kept constant at 40 degrees C. For the on-capillary cleanup method, a solution containing 50 mg/L of c-SWNTs prepared in 300 mM borate solution at pH 9.5 was introduced for 60 s into the capillary just before sample introduction. For the electrophoretic analysis of samples cleaned in batch with diatomaceous earth, it is also recommended to introduce into the capillary, just before the sample, a 300 mM borate solution as it enhances the sensitivity and electrophoretic resolution.

  16. Three-dimensional echocardiography of normal and pathologic mitral valve: a comparison with two-dimensional transesophageal echocardiography

    NARCIS (Netherlands)

    Salustri, A.; Becker, A. E.; van Herwerden, L.; Vletter, W. B.; ten Cate, F. J.; Roelandt, J. R.

    1996-01-01

    This study was done to ascertain whether three-dimensional echocardiography can facilitate the diagnosis of mitral valve abnormalities. The value of the additional information provided by three-dimensional echocardiography compared with two-dimensional multiplane transesophageal echocardiography for

  17. Two-Dimensional Motions of Rockets

    Science.gov (United States)

    Kang, Yoonhwan; Bae, Saebyok

    2007-01-01

    We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the…

  18. Two-Dimensional Theory of Scientific Representation

    Directory of Open Access Journals (Sweden)

    A Yaghmaie

    2013-03-01

    Full Text Available Scientific representation is an interesting topic for philosophers of science, many of whom have recently explored it from different points of view. There are currently two competing approaches to the issue: cognitive and non-cognitive, and each of them claims its own merits over the other. This article tries to provide a hybrid theory of scientific representation, called Two-Dimensional Theory of Scientific Representation, which has the merits of the two accounts and is free of their shortcomings. To do this, we will argue that although scientific representation needs to use the notion of intentionality, such a notion is defined and realized in a simply structural form contrary to what cognitive approach says about intentionality. After a short introduction, the second part of the paper is devoted to introducing theories of scientific representation briefly. In the third part, the structural accounts of representation will be criticized. The next step is to introduce the two-dimensional theory which involves two key components: fixing and structural fitness. It will be argued that fitness is an objective and non-intentional relation, while fixing is intentional.

  19. Buffalo milk: proteins electrophoretic profile and somatic cell count

    Directory of Open Access Journals (Sweden)

    S. Mattii

    2011-03-01

    Full Text Available Water buffalo milk differs from the cow’s milk for greater fat and protein content, very important features in cheese making. Proteins, casein and whey-proteins in particular, are the most important factors determining cheese yield. Several previous research discussed the rule of SCC in cow milk production (Varisco, 1999 and the close relationship existing between cow’s milk cheese yield and somatic cell count (Barbano, 2000. In particular the inverse correlation between cheese yields and somatic cells’content have been demonstrated. In Italy the regulation in force DPR 54/97 acknowledges what expressed in EEC 46/92 Directive (Tripodi, 1999 without fixing the limit threshold of somatic cells for buffalo’s milk....

  20. Comparison of one- and two-dimensional liquid chromatography approaches in the label-free quantitative analysis of Methylocella silvestris.

    Science.gov (United States)

    Patel, Nisha A; Crombie, Andrew; Slade, Susan E; Thalassinos, Konstantinos; Hughes, Chris; Connolly, Joanne B; Langridge, James; Murrell, J Colin; Scrivens, James H

    2012-09-07

    The proteome of the bacterium Methylocella silvestris has been characterized using reversed phase ultra high pressure liquid chromatography (UPLC) and two-dimensional reversed phase (high pH)-reversed phase (low pH) UPLC prior to mass spectrometric analysis. Variations in protein expression levels were identified with the aid of label-free quantification in a study of soluble protein extracts from the organism grown using methane, succinate, or propane as a substrate. The number of first dimensional fractionation steps has been varied for 2D analyses, and the impact on data throughput and quality has been demonstrated. Comparisons have been made regarding required experimental considerations including total loading of biological samples required, instrument time, and resulting data file sizes. The data obtained have been evaluated with respect to number of protein identifications, confidence of assignments, sequence coverage, relative levels of proteins, and dynamic range. Good qualitative and quantitative agreement was observed between the different approaches, and the potential benefits and limitations of the reversed phase-reversed phase UPLC technique in label-free analysis are discussed. A preliminary screen of the protein regulation data has also been performed, providing evidence for a possible propane assimilation route.

  1. Two dimensional crystals of LH2 light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus investigated by electron microscopy

    NARCIS (Netherlands)

    Oling, Frank; Boekema, EJ; deZarate, IO; Visschers, R; vanGrondelle, R; Keegstra, W; Brisson, A; Picorel, R

    1996-01-01

    Two-dimensional crystals of LH2 (B800-850) light-harvesting complexes from Ectothiorhodospira sp, and Rhodobacter capsulatus were obtained by reconstitution of purified protein into phospholipid vesicles and characterized by electron microscopy. The size of the crystals was up to several

  2. Two-dimensional crystals of LH2 light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus investigated by electron microscopy.

    NARCIS (Netherlands)

    Oling, F.; Boekema, E.J.; Ortiz de Zarate, I.; Visschers, R.W.; van Grondelle, R.; Keegstra, W.; Brisson, A.; Picorel, R.

    1996-01-01

    Two-dimensional crystals of LH2 (B800-850) light-harvesting complexes from Ectothiorhodospira sp. and Rhodobacter capsulatus were obtained by reconstitution of purified protein into phospholipid vesicles and characterized by electron microscopy. The size of the crystals was up to several

  3. Two-dimensional Simulations of Correlation Reflectometry in Fusion Plasmas

    International Nuclear Information System (INIS)

    Valeo, E.J.; Kramer, G.J.; Nazikian, R.

    2001-01-01

    A two-dimensional wave propagation code, developed specifically to simulate correlation reflectometry in large-scale fusion plasmas is described. The code makes use of separate computational methods in the vacuum, underdense and reflection regions of the plasma in order to obtain the high computational efficiency necessary for correlation analysis. Simulations of Tokamak Fusion Test Reactor (TFTR) plasma with internal transport barriers are presented and compared with one-dimensional full-wave simulations. It is shown that the two-dimensional simulations are remarkably similar to the results of the one-dimensional full-wave analysis for a wide range of turbulent correlation lengths. Implications for the interpretation of correlation reflectometer measurements in fusion plasma are discussed

  4. Volume scanning three-dimensional display with an inclined two-dimensional display and a mirror scanner

    Science.gov (United States)

    Miyazaki, Daisuke; Kawanishi, Tsuyoshi; Nishimura, Yasuhiro; Matsushita, Kenji

    2001-11-01

    A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cross-section patterns of a three-dimensional object are displayed sequentially. A vector-scan CRT display unit is used to obtain a high-resolution image. An optical scanning system is constructed with concave mirrors and a galvanometer mirror. It is confirmed that three-dimensional images, formed by the experimental system, satisfy all the criteria for human stereoscopic vision.

  5. Effect of surfactant species and electrophoretic medium composition on the electrophoretic behavior of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis.

    Science.gov (United States)

    Fukai, Nao; Kitagawa, Shinya; Ohtani, Hajime

    2017-07-01

    We have recently demonstrated the separation of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis (NACZE) using a cationic surfactant of cetyltrimethylammonium chloride (CTAC). In this study, eight ionic surfactants were investigated for the separation of four synthetic polymers (polystyrene, polymethylmethacrylates, polybutadiene, and polycarbonate); only three surfactants (CTAC, dimethyldioctadecylammonium bromide, and sodium dodecylsulfate) caused their separation. The order of the interaction between the polymers and the surfactants depended on both the surfactant species and the composition of the electrophoretic medium. Their investigation revealed that the separation is majorly affected by the hydrophobic interactions between the polymers and the ionic surfactants. In addition, the electrophoretic behavior of polycarbonate suggested that electrostatic interaction also affects the selectivity of the polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Three-dimensional tokamak equilibria and stellarators with two-dimensional magnetic symmetry

    International Nuclear Information System (INIS)

    Garabedian, P.R.

    1997-01-01

    Three-dimensional computer codes have been developed to simulate equilibrium, stability and transport in tokamaks and stellarators. Bifurcated solutions of the tokamak problem suggest that three-dimensional effects may be more important than has generally been thought. Extensive calculations have led to the discovery of a stellarator configuration with just two field periods and with aspect ratio 3.2 that has a magnetic field spectrum B mn with toroidal symmetry. Numerical studies of equilibrium, stability and transport for this new device, called the Modular Helias-like Heliac 2 (MHH2), will be presented. (author)

  7. A two-stage preventive maintenance optimization model incorporating two-dimensional extended warranty

    International Nuclear Information System (INIS)

    Su, Chun; Wang, Xiaolin

    2016-01-01

    In practice, customers can decide whether to buy an extended warranty or not, at the time of item sale or at the end of the basic warranty. In this paper, by taking into account the moments of customers purchasing two-dimensional extended warranty, the optimization of imperfect preventive maintenance for repairable items is investigated from the manufacturer's perspective. A two-dimensional preventive maintenance strategy is proposed, under which the item is preventively maintained according to a specified age interval or usage interval, whichever occurs first. It is highlighted that when the extended warranty is purchased upon the expiration of the basic warranty, the manufacturer faces a two-stage preventive maintenance optimization problem. Moreover, in the second stage, the possibility of reducing the servicing cost over the extended warranty period is explored by classifying customers on the basis of their usage rates and then providing them with customized preventive maintenance programs. Numerical examples show that offering customized preventive maintenance programs can reduce the manufacturer's warranty cost, while a larger saving in warranty cost comes from encouraging customers to buy the extended warranty at the time of item sale. - Highlights: • A two-dimensional PM strategy is investigated. • Imperfect PM strategy is optimized by considering both two-dimensional BW and EW. • Customers are categorized based on their usage rates throughout the BW period. • Servicing cost of the EW is reduced by offering customized PM programs. • Customers buying the EW at the time of sale is preferred for the manufacturer.

  8. Vibrations of thin piezoelectric shallow shells: Two-dimensional ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    In this paper we consider the eigenvalue problem for piezoelectric shallow shells and we show that, as the thickness of the shell goes to zero, the eigensolutions of the three-dimensional piezoelectric shells converge to the eigensolutions of a two- dimensional eigenvalue problem. Keywords. Vibrations; piezoelectricity ...

  9. Two-dimensional turbulent flows on a bounded domain

    NARCIS (Netherlands)

    Kramer, W.

    2006-01-01

    Large-scale flows in the oceans and the atmosphere reveal strong similarities with purely two-dimensional flows. One of the most typical features is the cascade of energy from smaller flow scales towards larger scales. This is opposed to three-dimensional turbulence where larger flow structures

  10. In-Depth Characterization of the Phaseolin Protein Diversity of Common Bean (Phaseolus vulgaris L. Based on Two-Dimensional Electrophoresis and Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    María López-Pedrouso

    2012-01-01

    Full Text Available Phaseolin is the major seed storage protein of common bean. It comprises a complex set of glycoproteins heterogeneous in their polypeptide composition that is encoded by a gene family. Analyses of phaseolin banding patterns by one-dimensional electrophoresis (SDS-PAGE have been central to the current understanding of the diversity of wild and cultivated common beans. In this work, we have carried out a detailed description and interpretation of phaseolin diversity in cultivated common beans of different geographic origins (Mesoamerican and Andean gene pools based on the current two-dimensional electrophoresis (2-DE technology and mass spectrometry (MS. High-quality 2-DE gel images revealed very complex phaseolin patterns across the studied cultivars. Specifically, patterns of phaseolin within cultivars were organized in a horizontal string of multiple isospot pairs varying in isoelectric point and molecular mass. The degree of similarity among phaseolin patterns was estimated from the percentage of spots shared between pairs of cultivars. Analyses of proteomic distances between phaseolin types by non-metrical multidimensional scaling revealed that 2-DE phaseolin profiles are more similar among cultivars belonging to the same gene pool. However, higher differentiation was found among cultivars of the Andean gene pool. Analysis of genetic variations of the PCR-based SCAR marker of phaseolin seed protein was in general agreement with 2-DE phaseolin patterns, but provided supplementary information regarding diversity among cultivars. Furthermore, the molecular basis responsible for the complexity of 2-DE phaseolin patterns was investigated. Thus, identification of phaseolin spots from 2-DE gels by MALDI-TOF and MALDI-TOF/TOF MS showed that each single isospot pair contained only one type (α or β of phaseolin polypeptide, but pairs with higher and lower molecular mass corresponded to α- and β-type polypeptides, respectively. In addition, partial

  11. Intrinsic two-dimensional states on the pristine surface of tellurium

    Science.gov (United States)

    Li, Pengke; Appelbaum, Ian

    2018-05-01

    Atomic chains configured in a helical geometry have fascinating properties, including phases hosting localized bound states in their electronic structure. We show how the zero-dimensional state—bound to the edge of a single one-dimensional helical chain of tellurium atoms—evolves into two-dimensional bands on the c -axis surface of the three-dimensional trigonal bulk. We give an effective Hamiltonian description of its dispersion in k space by exploiting confinement to a virtual bilayer, and elaborate on the diminished role of spin-orbit coupling. These intrinsic gap-penetrating surface bands were neglected in the interpretation of seminal experiments, where two-dimensional transport was otherwise attributed to extrinsic accumulation layers.

  12. Determining the static electronic and vibrational energy correlations via two-dimensional electronic-vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Hui; Lewis, Nicholas H. C.; Oliver, Thomas A. A.; Fleming, Graham R., E-mail: grfleming@lbl.gov [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, Californial 94720 (United States); Kavli Energy NanoSciences Institute at Berkeley, Berkeley, California 94720 (United States)

    2015-05-07

    Changes in the electronic structure of pigments in protein environments and of polar molecules in solution inevitably induce a re-adaption of molecular nuclear structure. Both changes of electronic and vibrational energies can be probed with visible or infrared lasers, such as two-dimensional electronic spectroscopy or vibrational spectroscopy. The extent to which the two changes are correlated remains elusive. The recent demonstration of two-dimensional electronic-vibrational (2DEV) spectroscopy potentially enables a direct measurement of this correlation experimentally. However, it has hitherto been unclear how to characterize the correlation from the spectra. In this paper, we present a theoretical formalism to demonstrate the slope of the nodal line between the excited state absorption and ground state bleach peaks in the spectra as a characterization of the correlation between electronic and vibrational transition energies. We also show the dynamics of the nodal line slope is correlated to the vibrational spectral dynamics. Additionally, we demonstrate the fundamental 2DEV spectral line-shape of a monomer with newly developed response functions.

  13. Iterative Two- and One-Dimensional Methods for Three-Dimensional Neutron Diffusion Calculations

    International Nuclear Information System (INIS)

    Lee, Hyun Chul; Lee, Deokjung; Downar, Thomas J.

    2005-01-01

    Two methods are proposed for solving the three-dimensional neutron diffusion equation by iterating between solutions of the two-dimensional (2-D) radial and one-dimensional (1-D) axial solutions. In the first method, the 2-D/1-D equations are coupled using a current correction factor (CCF) with the average fluxes of the lower and upper planes and the axial net currents at the plane interfaces. In the second method, an analytic expression for the axial net currents at the interface of the planes is used for planar coupling. A comparison of the new methods is made with two previously proposed methods, which use interface net currents and partial currents for planar coupling. A Fourier convergence analysis of the four methods was performed, and results indicate that the two new methods have at least three advantages over the previous methods. First, the new methods are unconditionally stable, whereas the net current method diverges for small axial mesh size. Second, the new methods provide better convergence performance than the other methods in the range of practical mesh sizes. Third, the spectral radii of the new methods asymptotically approach zero as the mesh size increases, while the spectral radius of the partial current method approaches a nonzero value as the mesh size increases. Of the two new methods proposed here, the analytic method provides a smaller spectral radius than the CCF method, but the CCF method has several advantages over the analytic method in practical applications

  14. Construction of two-dimensional quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Klimek, S.; Kondracki, W.

    1987-12-01

    We present a sketch of the construction of the functional measure for the SU(2) quantum chromodynamics with one generation of fermions in two-dimensional space-time. The method is based on a detailed analysis of Wilson loops.

  15. A two-dimensional Zn coordination polymer with a three-dimensional supra-molecular architecture.

    Science.gov (United States)

    Liu, Fuhong; Ding, Yan; Li, Qiuyu; Zhang, Liping

    2017-10-01

    The title compound, poly[bis-{μ 2 -4,4'-bis-[(1,2,4-triazol-1-yl)meth-yl]biphenyl-κ 2 N 4 : N 4' }bis-(nitrato-κ O )zinc(II)], [Zn(NO 3 ) 2 (C 18 H 16 N 6 ) 2 ] n , is a two-dimensional zinc coordination polymer constructed from 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl units. It was synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Zn II cation is located on an inversion centre and is coordinated by two O atoms from two symmetry-related nitrate groups and four N atoms from four symmetry-related 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl ligands, forming a distorted octa-hedral {ZnN 4 O 2 } coordination geometry. The linear 4,4'-bis-[(1 H -1,2,4-triazol-1-yl)meth-yl]-1,1'-biphenyl ligand links two Zn II cations, generating two-dimensional layers parallel to the crystallographic (132) plane. The parallel layers are connected by C-H⋯O, C-H⋯N, C-H⋯π and π-π stacking inter-actions, resulting in a three-dimensional supra-molecular architecture.

  16. Two-dimensional effects in nonlinear Kronig-Penney models

    DEFF Research Database (Denmark)

    Gaididei, Yuri Borisovich; Christiansen, Peter Leth; Rasmussen, Kim

    1997-01-01

    An analysis of two-dimensional (2D) effects in the nonlinear Kronig-Penney model is presented. We establish an effective one-dimensional description of the 2D effects, resulting in a set of pseudodifferential equations. The stationary states of the 2D system and their stability is studied...

  17. Noninteracting beams of ballistic two-dimensional electrons

    International Nuclear Information System (INIS)

    Spector, J.; Stormer, H.L.; Baldwin, K.W.; Pfeiffer, L.N.; West, K.W.

    1991-01-01

    We demonstrate that two beams of two-dimensional ballistic electrons in a GaAs-AlGaAs heterostructure can penetrate each other with negligible mutual interaction analogous to the penetration of two optical beams. This allows electrical signal channels to intersect in the same plane with negligible crosstalk between the channels

  18. Control Operator for the Two-Dimensional Energized Wave Equation

    Directory of Open Access Journals (Sweden)

    Sunday Augustus REJU

    2006-07-01

    Full Text Available This paper studies the analytical model for the construction of the two-dimensional Energized wave equation. The control operator is given in term of space and time t independent variables. The integral quadratic objective cost functional is subject to the constraint of two-dimensional Energized diffusion, Heat and a source. The operator that shall be obtained extends the Conjugate Gradient method (ECGM as developed by Hestenes et al (1952, [1]. The new operator enables the computation of the penalty cost, optimal controls and state trajectories of the two-dimensional energized wave equation when apply to the Conjugate Gradient methods in (Waziri & Reju, LEJPT & LJS, Issues 9, 2006, [2-4] to appear in this series.

  19. Equilibrium: two-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In Chapter 6, the problem of toroidal force balance is addressed in the simplest, nontrivial two-dimensional geometry, that of an axisymmetric torus. A derivation is presented of the Grad-Shafranov equation, the basic equation describing axisymmetric toroidal equilibrium. The solutions to equations provide a complete description of ideal MHD equilibria: radial pressure balance, toroidal force balance, equilibrium Beta limits, rotational transform, shear, magnetic wall, etc. A wide number of configurations are accurately modeled by the Grad-Shafranov equation. Among them are all types of tokamaks, the spheromak, the reversed field pinch, and toroidal multipoles. An important aspect of the analysis is the use of asymptotic expansions, with an inverse aspect ratio serving as the expansion parameter. In addition, an equation similar to the Grad-Shafranov equation, but for helically symmetric equilibria, is presented. This equation represents the leading-order description low-Beta and high-Beta stellarators, heliacs, and the Elmo bumpy torus. The solutions all correspond to infinitely long straight helices. Bending such a configuration into a torus requires a full three-dimensional calculation and is discussed in Chapter 7

  20. Comparative aspects of basic chromatin proteins in dinoflagellates.

    Science.gov (United States)

    Rizzo, P J

    1981-01-01

    Previous work on histone-like proteins in dinoflagellates is summarized, together with some new data to give an overview of basic proteins in these algae. The first two dinoflagellates studied were both found to contain one major acid-soluble protein that migrated to the same position in acidic-urea gels. When several other genera were studied however, it became apparent that the histone-like proteins from different dinoflagellates were similar but not identical. In view of the great diversity of living dinoflagellates it is speculated that further differences in dinoflagellate basic chromatin proteins will be revealed. Electrophoretic data from the eukaryotic (endosymbiont) nucleus of Peridinium balticum showed the presence of five major components. It is speculated that two of these proteins represent an H1-like doublet and two others correspond to the highly conserved histones H3 and H4. The fifth component is a new histone that may substitute for H2A and H2B in the nucleosome. Because histones and nucleosomes are present in all higher organisms but completely lacking in procaryotes, studies on basic proteins in dinoflagellates will provides insights into the evolution of histones and eucaryotic chromatin organization.

  1. Extended Polymorphism of Two-Dimensional Material

    NARCIS (Netherlands)

    Yoshida, Masaro; Ye, Jianting; Zhang, Yijin; Imai, Yasuhiko; Kimura, Shigeru; Fujiwara, Akihiko; Nishizaki, Terukazu; Kobayashi, Norio; Nakano, Masaki; Iwasa, Yoshihiro

    When controlling electronic properties of bulk materials, we usually assume that the basic crystal structure is fixed. However, in two-dimensional (2D) materials, atomic structure or to functionalize their properties. Various polymorphs can exist in transition metal dichalcogenides (TMDCs) from

  2. Two-dimensional nonlinear equations of supersymmetric gauge theories

    International Nuclear Information System (INIS)

    Savel'ev, M.V.

    1985-01-01

    Supersymmetric generalization of two-dimensional nonlinear dynamical equations of gauge theories is presented. The nontrivial dynamics of a physical system in the supersymmetry and supergravity theories for (2+2)-dimensions is described by the integrable embeddings of Vsub(2/2) superspace into the flat enveloping superspace Rsub(N/M), supplied with the structure of a Lie superalgebra. An equation is derived which describes a supersymmetric generalization of the two-dimensional Toda lattice. It contains both super-Liouville and Sinh-Gordon equations

  3. Seed protein variations of Salicornia L. and allied taxa in Turkey.

    Science.gov (United States)

    Yaprak, A E; Yurdakulol, E

    2007-06-01

    Electrophoretic seed protein patterns of a number of accessions of Salicornia europaea L. sl., S. prostrata Palas, S. fragilis P.W. Ball and Tutin, Sarcocornia fruticosa (L.) A. J. Scott, Sarcocornia perennis (Miller.) A. J. Scott, Arthrocnemum glaucum (Del.) Ung.-Sternb., Microcnemum coralloides (Loscos and Pardo) subsp. anatolicum Wagenitz and Halocnemum strobilaceum (Pall.) Bieb. were electrophoretically analysed on SDS-PAGE. In total 48 different bands were identified. The obtained data have been treated numerically using the cluster analysis method of unweighted pair group (UPGMA). Finally it was determined that all species separated according to seed protein profiles. And the cladogram obtained studied taxa have been given.

  4. Cobalt ferrite nanoparticles with improved aqueous colloidal stability and electrophoretic mobility

    International Nuclear Information System (INIS)

    Munjal, Sandeep; Khare, Neeraj

    2016-01-01

    We have synthesized CoFe 2 O 4 (CFO) nanoparticles of size ∼ 12.2 nm by hydrothermal synthesis method. To control the size of these CFO nanoparticles, oleic acid was used as a surfactant. The inverse spinel phase of the synthesized nanoparticles was confirmed by X-ray diffraction method. As synthesized oleic acid coated CFO (OA@CFO) nanoparticles has very less electrophoretic mobility in the water and are not water dispersible. These OA@CFO nanoparticles were successfully turned into water soluble phase with a better colloidal aqueous stability, through a chemical treatment using citric acid. The modified citric acid coated CFO (CA@CFO) nanoparticles were dispersible in water and form a stable aqueous solution with high electrophoretic mobility.

  5. Canine serum protein patterns using high-resolution electrophoresis (HRE).

    Science.gov (United States)

    Abate, O; Zanatta, R; Malisano, T; Dotta, U

    2000-03-01

    Serum protein values were determined in 26 healthy dogs using agarose gel electrophoresis (SPE), splitting the electrophoretic separation into six regions: albumin, alpha(1), alpha(2), beta(1), beta(2)and gamma globulins. High-resolution electrophoresis (HRE) was used to separate single proteins. Serum proteins from dogs (26 healthy and 20 affected by various diseases) were then characterized by electrophoretic immunofixation (IFE) and Sudan black staining on HRE film. Haemoglobin and normal canine plasma and serum were used to identify haptoglobin and fibrinogen, respectively. In the standard pattern, determined by HRE, the following proteins were identified: albumin, alpha(1)-lipoprotein (alpha(1)-region), haptoglobin and alpha(2)-macroglobulin (alpha(2)-region), beta -lipoprotein and C3 (beta(1)-region), transferrin and IgM (beta(2)-region), IgG (mostly in gamma -region and partly in beta(2)-region). The HRE pattern shown by healthy dogs could be compared with those of dogs affected by various diseases to obtain clinical information. Copyright 2000 Harcourt Publishers Ltd.

  6. Superintegrability on the two dimensional hyperboloid

    International Nuclear Information System (INIS)

    Akopyan, E.; Pogosyan, G.S.; Kalnins, E.G.; Miller, W. Jr

    1998-01-01

    This work is devoted to the investigation of the quantum mechanical systems on the two dimensional hyperboloid which admit separation of variables in at least two coordinate systems. Here we consider two potentials introduced in a paper of C.P.Boyer, E.G.Kalnins and P.Winternitz, which haven't been studied yet. An example of an interbasis expansion is given and the structure of the quadratic algebra generated by the integrals of motion is carried out

  7. Few helium atoms in quasi two-dimensional space

    International Nuclear Information System (INIS)

    Kilic, Srecko; Vranjes, Leandra

    2003-01-01

    Two, three and four 3 He and 4 He atoms in quasi two-dimensional space above graphite and cesium surfaces and in 'harmonic' potential perpendicular to the surface have been studied. Using some previously examined variational wave functions and the Diffusion Monte Carlo procedure, it has been shown that all molecules: dimers, trimers and tetramers, are bound more strongly than in pure two- and three-dimensional space. The enhancement of binding with respect to unrestricted space is more pronounced on cesium than on graphite. Furthermore, for 3 He 3 ( 3 He 4 ) on all studied surfaces, there is an indication that the configuration of a dimer and a 'free' particle (two dimers) may be equivalently established

  8. Electronic transport on the spatial structure of the protein: Three-dimensional lattice model

    International Nuclear Information System (INIS)

    Sarmento, R.G.; Frazão, N.F.; Macedo-Filho, A.

    2017-01-01

    Highlights: • The electronic transport on the structure of the three-dimensional lattice model of the protein is studied. • The signing of the current–voltage is directly affected by permutations of the weak bonds in the structure. • Semiconductor behave of the proteins suggest a potential application in the development of novel biosensors. - Abstract: We report a numerical analysis of the electronic transport in protein chain consisting of thirty-six standard amino acids. The protein chains studied have three-dimensional structure, which can present itself in three distinct conformations and the difference consist in the presence or absence of thirteen hydrogen-bondings. Our theoretical method uses an electronic tight-binding Hamiltonian model, appropriate to describe the protein segments modeled by the amino acid chain. We note that the presence and the permutations between weak bonds in the structure of proteins are directly related to the signing of the current–voltage. Furthermore, the electronic transport depends on the effect of temperature. In addition, we have found a semiconductor behave in the models investigated and it suggest a potential application in the development of novel biosensors for molecular diagnostics.

  9. Electronic transport on the spatial structure of the protein: Three-dimensional lattice model

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, R.G. [Departamento de Ciências Biológicas, Universidade Federal do Piauí, 64800-000 Floriano, PI (Brazil); Frazão, N.F. [Centro de Educação e Saúde, Universidade Federal de Campina Grande, 581750-000 Cuité, PB (Brazil); Macedo-Filho, A., E-mail: amfilho@gmail.com [Campus Prof. Antonio Geovanne Alves de Sousa, Universidade Estadual do Piauí, 64260-000 Piripiri, PI (Brazil)

    2017-01-30

    Highlights: • The electronic transport on the structure of the three-dimensional lattice model of the protein is studied. • The signing of the current–voltage is directly affected by permutations of the weak bonds in the structure. • Semiconductor behave of the proteins suggest a potential application in the development of novel biosensors. - Abstract: We report a numerical analysis of the electronic transport in protein chain consisting of thirty-six standard amino acids. The protein chains studied have three-dimensional structure, which can present itself in three distinct conformations and the difference consist in the presence or absence of thirteen hydrogen-bondings. Our theoretical method uses an electronic tight-binding Hamiltonian model, appropriate to describe the protein segments modeled by the amino acid chain. We note that the presence and the permutations between weak bonds in the structure of proteins are directly related to the signing of the current–voltage. Furthermore, the electronic transport depends on the effect of temperature. In addition, we have found a semiconductor behave in the models investigated and it suggest a potential application in the development of novel biosensors for molecular diagnostics.

  10. Electrophoretic protein polymorphisms in Kaingang and Guarani Indians of Southern Brazil.

    Science.gov (United States)

    Salzano, Francisco M; Callegari-Jacques, Sidia M; Weimer, Tania A; Franco, Maria H L P; Hutz, Mara H; Petzl-Erler, Maria L

    1997-01-01

    A total of 337 Kaingang and Guarani Indians from two localities were studied in relation to 18 protein genetic loci. In one of the localities, members of these two groups live side by side but show little genetic similarity, emphasizing the influence of cultural factors in the mating behavior of human groups. Integrating the present results with previous ones, it was verified that the genetic relationships among six Kaingang populations do not follow the pattern expected from their geographical distribution. Comparisons made with three other Ge˜-speaking tribes indicate that the Kaingang did not separate well from them. Most (96%) of the variability in the six polymorphic systems considered occur at the intrapopulational level. Am. J. Hum. Biol. 9:505-512, 1997. © 1997 Wiley-Liss, Inc. Copyright © 1997 Wiley-Liss, Inc.

  11. Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

    Science.gov (United States)

    Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

    1996-01-01

    Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

  12. Exploring two-dimensional electron gases with two-dimensional Fourier transform spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Paul, J.; Dey, P.; Karaiskaj, D., E-mail: karaiskaj@usf.edu [Department of Physics, University of South Florida, 4202 East Fowler Ave., Tampa, Florida 33620 (United States); Tokumoto, T.; Hilton, D. J. [Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294 (United States); Reno, J. L. [CINT, Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2014-10-07

    The dephasing of the Fermi edge singularity excitations in two modulation doped single quantum wells of 12 nm and 18 nm thickness and in-well carrier concentration of ∼4 × 10{sup 11} cm{sup −2} was carefully measured using spectrally resolved four-wave mixing (FWM) and two-dimensional Fourier transform (2DFT) spectroscopy. Although the absorption at the Fermi edge is broad at this doping level, the spectrally resolved FWM shows narrow resonances. Two peaks are observed separated by the heavy hole/light hole energy splitting. Temperature dependent “rephasing” (S{sub 1}) 2DFT spectra show a rapid linear increase of the homogeneous linewidth with temperature. The dephasing rate increases faster with temperature in the narrower 12 nm quantum well, likely due to an increased carrier-phonon scattering rate. The S{sub 1} 2DFT spectra were measured using co-linear, cross-linear, and co-circular polarizations. Distinct 2DFT lineshapes were observed for co-linear and cross-linear polarizations, suggesting the existence of polarization dependent contributions. The “two-quantum coherence” (S{sub 3}) 2DFT spectra for the 12 nm quantum well show a single peak for both co-linear and co-circular polarizations.

  13. Two-dimensional time dependent Riemann solvers for neutron transport

    International Nuclear Information System (INIS)

    Brunner, Thomas A.; Holloway, James Paul

    2005-01-01

    A two-dimensional Riemann solver is developed for the spherical harmonics approximation to the time dependent neutron transport equation. The eigenstructure of the resulting equations is explored, giving insight into both the spherical harmonics approximation and the Riemann solver. The classic Roe-type Riemann solver used here was developed for one-dimensional problems, but can be used in multidimensional problems by treating each face of a two-dimensional computation cell in a locally one-dimensional way. Several test problems are used to explore the capabilities of both the Riemann solver and the spherical harmonics approximation. The numerical solution for a simple line source problem is compared to the analytic solution to both the P 1 equation and the full transport solution. A lattice problem is used to test the method on a more challenging problem

  14. On the ground state of the two-dimensional non-ideal Bose gas

    International Nuclear Information System (INIS)

    Lozovik, Yu.E.; Yudson, V.I.

    1978-01-01

    The theory of the ground state of the two-dimensional non-ideal Bose gas is presented. The conditions for the validity of the ladder and the Bogolubov approximations are derived. These conditions ensure the existence of a Bose condensate in the ground state of two-dimensional systems. These conditions are different from the corresponding conditions for the three-dimensional case. The connection between the effective interaction and the two-dimensional scattering amplitude at some characteristic energy kappa 2 /2m (not equal to 0) is obtained (f(kappa = 0) = infinity in the two-dimensional case). (Auth.)

  15. Method for coupling two-dimensional to three-dimensional discrete ordinates calculations

    International Nuclear Information System (INIS)

    Thompson, J.L.; Emmett, M.B.; Rhoades, W.A.; Dodds, H.L. Jr.

    1985-01-01

    A three-dimensional (3-D) discrete ordinates transport code, TORT, has been developed at the Oak Ridge National Laboratory for radiation penetration studies. It is not feasible to solve some 3-D penetration problems with TORT, such as a building located a large distance from a point source, because (a) the discretized 3-D problem is simply too big to fit on the computer or (b) the computing time (and corresponding cost) is prohibitive. Fortunately, such problems can be solved with a hybrid approach by coupling a two-dimensional (2-D) description of the point source, which is assumed to be azimuthally symmetric, to a 3-D description of the building, the region of interest. The purpose of this paper is to describe this hybrid methodology along with its implementation and evaluation in the DOTTOR (Discrete Ordinates to Three-dimensional Oak Ridge Transport) code

  16. Warranty menu design for a two-dimensional warranty

    International Nuclear Information System (INIS)

    Ye, Zhi-Sheng; Murthy, D.N. Pra

    2016-01-01

    Fierce competitions in the commercial product market have forced manufacturers to provide customer-friendly warranties with a view to achieving higher customer satisfaction and increasing the market share. This study proposes a strategy that offers customers a two-dimensional warranty menu with a number of warranty choices, called a flexible warranty policy. We investigate the design of a flexible two-dimensional warranty policy that contains a number of rectangular regions. This warranty policy is obtained by dividing customers into several groups according to their use rates and providing each group a germane warranty region. Consumers choose a favorable one from the menu according to their usage behaviors. Evidently, this flexible warranty policy is attractive to users of different usage behaviors, and thus, it gives the manufacturer a good position in advertising the product. When consumers are unaware about their use rates upon purchase, we consider a fixed two-dimensional warranty policy with a stair-case warranty region and show that it is equivalent to the flexible policy. Such an equivalence reveals the inherent relationship between the rectangular warranty policy, the L-shape warranty policy, the step-stair warranty policy and the iso-probability of failure warranty policy that were extensively discussed in the literature. - Highlights: • We design a two-dimensional warranty menu with a number of warranty choices. • Consumers can choose a favorable one from the menu as per their usage behavior. • We further consider a fixed 2D warranty policy with a stair-case warranty region. • We show the equivalence of the two warranty policies.

  17. Two-dimensional gel proteome reference map of human small intestine

    Directory of Open Access Journals (Sweden)

    Canzonieri Vincenzo

    2009-03-01

    Full Text Available Abstract Background The small intestine is an important human organ that plays a central role in many physiological functions including digestion, absorption, secretion and defense. Duodenal pathologies include, for instance, the ulcer associated to Helicobacter Pylori infection, adenoma and, in genetically predisposed individuals, celiac disease. Alterations in the bowel reduce its capability to absorb nutrients, minerals and fat-soluble vitamins. Anemia and osteopenia or osteoporosis may develop as a consequence of vitamins malabsorption. Adenoma is a benign tumor that has the potential to become cancerous. Adult celiac disease patients present an overall risk of cancer that is almost twice than that found in the general population. These disease processes are not completely known. To date, a two dimensional (2D reference map of proteins expressed in human duodenal tissue is not yet available: the aim of our study was to characterize the 2D protein map, and to identify proteins of duodenal mucosa of adult individuals without duodenal illness, to create a protein database. This approach, may be useful for comparing similar protein samples in different laboratories and for the molecular characterization of intestinal pathologies without recurring to the use of surgical material. Results The enrolled population comprised five selected samples (3 males and 2 females, aged 19 to 42, taken from 20 adult subjects, on their first visit at the gastroenterology unit for a suspected celiac disease, who did not turn to be affected by any duodenal pathology after gastrointestinal and histological evaluations. Proteins extracted from the five duodenal mucosal specimens were singly separated by 2D gel electrophoresis. After image analysis of each 2D gel, 179 protein spots, representing 145 unique proteins, from 218 spots tested, were successfully identified by MALDI-TOF ms analysis. Normalized volumes, for each protein, have been reported for every gel

  18. Two-dimensional condensation of physi-sorbed methane on layer-like halides

    International Nuclear Information System (INIS)

    Nardon, Yves

    1972-01-01

    Two-dimensional condensation of methane in physi-sorbed layers has been studied from sets of stepped isotherms of methane on the cleavage plane of layer-like halides (FeCl 2 , CdCl 2 , NiBr 2 , CdBr 2 , FeI 2 , CaI 2 , CaI 2 and PbI 2 ) in most cases prepared by sublimation in a rapid current of inert gas. The vertical parts of the steps of adsorption isotherms correspond to the formation of successive monomolecular layers by two-dimensional condensation. Thermodynamic analysis of experimental results, has mainly emphasized the important effect of the potential relief of adsorbent surfaces, on both the structure of the physi-sorbed layers and the two-dimensional critical temperature. From its entropy, we conclude that the first layer is a (111) plane of f.c.c.: methane which becomes more loosely packed as the dimensional compatibility of the lattices of the adsorbent and adsorbate becomes poorer. Experimental values of the two-dimensional critical temperatures in the first, second and third layers have been determined, and interpreted on the following basis. An expansion of the layer induces a lowering of the two-dimensional critical temperature by decreasing the lateral interaction energy, while a localisation of the adsorbed molecules in potential wells, when possible, induces a rise of the two-dimensional critical temperature. (author) [fr

  19. Tridodecylamine, an efficient charge control agent in non-polar media for electrophoretic inks application

    Science.gov (United States)

    Noel, Amélie; Mirbel, Déborah; Cloutet, Eric; Fleury, Guillaume; Schatz, Christophe; Navarro, Christophe; Hadziioannou, Georges; CyrilBrochon

    2018-01-01

    In order to obtain efficient electrophoretic inks, Tridodecylamine (Dod3N), has been studied as charge control agent (CCA) in a non-polar paraffin solvent (Isopar G) for various inorganic pigments (TiO2 and Fe2O3). All hydrophobic mineral oxides, i.e. treated with octyltrimethoxysilane (C8) or dodecyltrimethoxysilane (C12), were found to be negatively charged in presence of Dod3N. The electrophoretic mobilities of inorganic pigments seemed to be strongly dependent of their isoelectric point (IEP) and also of the concentration of dod3N with an optimum range between 10 and 20 mM depending on the pigments. Finally, an electrophoretic ink constituted of hydrophobic mineral oxides in presence of Dod3N was tested in a device. Its efficiency as charge control agent to negatively charge hydrophobic particles was confirmed through good optical properties and fast response time (220 ms at 200 kV m-1).

  20. Tubulin-isotype analysis of two grass species-resistant to dinitroaniline herbicides.

    Science.gov (United States)

    Waldin, T R; Ellis, J R; Hussey, P J

    1992-09-01

    Trifluralin-resistant biotypes of Eleusine indica (L.) Gaertn. (goosegrass) and Setaria viridis (L.) Beauv. (green foxtail) exhibit cross-resistance to other dinitroaniline herbicides. Since microtubules are considered the primary target site for dinitroaniline herbicides we investigated whether the differential sensitivity of resistant and susceptible biotypes of these species results from modified tubulin polypeptides. One-dimensional and two-dimensional polyacrylamide gel electrophoresis combined with immunoblotting using well-characterised anti-tubulin monoclonal antibodies were used to display the family of tubulin isotypes in each species. Seedlings of E. indica exhibited four β-tubulin isotypes and one α-tubulin isotype, whereas those of S. viridis exhibited two β-tubulin and two α-tubulin isotypes. Comparison of the susceptible and resistant biotypes within each species revealed no differences in electrophoretic properties of the multiple tubulin isotypes. These results provide no evidence that resistance to dinitroaniline herbicides is associated with a modified tubulin polypeptide in these biotypes of E. indica or S. viridis.

  1. Conformal invariance and two-dimensional physics

    International Nuclear Information System (INIS)

    Zuber, J.B.

    1993-01-01

    Actually, physicists and mathematicians are very interested in conformal invariance: geometric transformations which keep angles. This symmetry is very important for two-dimensional systems as phase transitions, string theory or node mathematics. In this article, the author presents the conformal invariance and explains its usefulness

  2. Multisoliton formula for completely integrable two-dimensional systems

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1979-01-01

    For general two-dimensional completely integrable systems, the exact formulae for multisoliton type solutions are given. The formulae are obtained algebrically from solutions of two linear partial differential equations

  3. Application of long-range order to predict unfolding rates of two-state proteins.

    Science.gov (United States)

    Harihar, B; Selvaraj, S

    2011-03-01

    Predicting the experimental unfolding rates of two-state proteins and models describing the unfolding rates of these proteins is quite limited because of the complexity present in the unfolding mechanism and the lack of experimental unfolding data compared with folding data. In this work, 25 two-state proteins characterized by Maxwell et al. (Protein Sci 2005;14:602–616) using a consensus set of experimental conditions were taken, and the parameter long-range order (LRO) derived from their three-dimensional structures were related with their experimental unfolding rates ln(k(u)). From the total data set of 30 proteins used by Maxwell et al. (Protein Sci 2005;14:602–616), five slow-unfolding proteins with very low unfolding rates were considered to be outliers and were not included in our data set. Except all beta structural class, LRO of both the all-alpha and mixed-class proteins showed a strong inverse correlation of r = -0.99 and -0.88, respectively, with experimental ln(k(u)). LRO shows a correlation of -0.62 with experimental ln(k(u)) for all-beta proteins. For predicting the unfolding rates, a simple statistical method has been used and linear regression equations were developed for individual structural classes of proteins using LRO, and the results obtained showed a better agreement with experimental results. Copyright © 2010 Wiley-Liss, Inc.

  4. The blind student’s interpretation of two-dimensional shapes in geometry

    Science.gov (United States)

    Andriyani; Budayasa, I. K.; Juniati, D.

    2018-01-01

    The blind student’s interpretation of two-dimensional shapes represents the blind student’s mental image of two-dimensional shapes that they can’t visualize directly, which is related to illustration of the characteristics and number of edges and angles. The objective of this research is to identify the blind student’s interpretation of two-dimensional shapes. This research was an exploratory study with qualitative approach. A subject of this research is a sixth-grade student who experiencing total blind from the fifth grade of elementary school. Researchers interviewed the subject about his interpretation of two-dimensional shapes according to his thinking.The findings of this study show the uniqueness of blind students, who have been totally blind since school age, in knowing and illustrating the characteristics of edges and angles of two-dimensional shapes by utilizing visual experiences that were previously obtained before the blind. The result can inspire teachers to design further learning for development of blind student geometry concepts.

  5. Juvenile hormone-binding proteins of Melanoplus bivittatus identified by EFDA photoaffinity labeling

    International Nuclear Information System (INIS)

    Winder, B.S.

    1988-01-01

    Proteins that bind juvenile hormone in the hemolymph and fat body of the grasshopper, Melanoplus bivittatus were identified by photoaffinity labeling with radiolabeled epoxyfarnesyl diazoacetate ( 3 H-EFDA), and were characterized by electrophoretic analysis. A protocol was developed which allowed detection of 3 H-EFDA that was covalently linked to proteins upon exposure to ultraviolet light at 254 nm. Quantification of protein-linked 3 H-EFDA by liquid scintillation spectrometry took advantage of the differential solubility of unlinked 3 H-EFDA in toluene alone, and of the protein-linked 3 H-EFDA in toluene plus the detergent, Triton X-100. Competition between EFDA and juvenile hormone (JH) for binding to JH-specific binding sites was measured by hydroxyapatite protein binding assays in the presence of radiolabeled JH or EFDA and competing non-radiolabeled hormone. The protein-linked EFDA was detected on fluorograms of SDS or nondenaturing polyacrylamide gels (PAGE), and by liquid scintillation spectrometry of membranes to which the proteins had been electrophoretically transferred. Proteins which specifically bound JH were identified by photolabeling proteins in the presence and absence of nonlabeled JH-III

  6. Critical Behaviour of a Two-Dimensional Random Antiferromagnet

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Birgeneau, R. J.; Guggenheim, H. J.

    1976-01-01

    A neutron scattering study of the order parameter, correlation length and staggered susceptibility of the two-dimensional random antiferromagnet Rb2Mn0.5Ni0.5F4 is reported. The system is found to exhibit a well-defined phase transition with critical exponents identical to those of the isomorphou...... pure materials K2NiF4 and K2MnF4. Thus, in these systems, which have the asymptotic critical behaviour of the two-dimensional Ising model, randomness has no measurable effect on the phase-transition behaviour....

  7. [Apply fourier transform infrared spectra coupled with two-dimensional correlation analysis to study the evolution of humic acids during composting].

    Science.gov (United States)

    Bu, Gui-jun; Yu, Jing; Di, Hui-hui; Luo, Shi-jia; Zhou, Da-zhai; Xiao, Qiang

    2015-02-01

    The composition and structure of humic acids formed during composting play an important influence on the quality and mature of compost. In order to explore the composition and evolution mechanism, municipal solid wastes were collected to compost and humic and fulvic acids were obtained from these composted municipal solid wastes. Furthermore, fourier transform infrared spectra and two-dimensional correlation analysis were applied to study the composition and transformation of humic and fulvic acids during composting. The results from fourier transform infrared spectra showed that, the composition of humic acids was complex, and several absorbance peaks were observed at 2917-2924, 2844-2852, 2549, 1662, 1622, 1566, 1454, 1398, 1351, 990-1063, 839 and 711 cm(-1). Compared to humic acids, the composition of fulvci acids was simple, and only three peaks were detected at 1725, 1637 and 990 cm(-1). The appearance of these peaks showed that both humic and fulvic acids comprised the benzene originated from lignin and the polysaccharide. In addition, humic acids comprised a large number of aliphatic and protein which were hardly detected in fulvic acids. Aliphatic, polysaccharide, protein and lignin all were degraded during composting, however, the order of degradation was different between humic and fulvci acids. The result from two-dimensional correlation analysis showed that, organic compounds in humic acids were degraded in the following sequence: aliphatic> protein> polysaccharide and lignin, while that in fulvic acids was as following: protein> polysaccharide and aliphatic. A large number of carboxyl, alcohols and ethers were formed during the degradation process, and the carboxyl was transformed into carbonates. It can be concluded that, fourier transform infrared spectra coupled with two-dimensional correlation analysis not only can analyze the function group composition of humic substances, but also can characterize effectively the degradation sequence of these

  8. Two-Dimensional Zymography of Proteases from Steatotic Duck Liver.

    Science.gov (United States)

    Wilkesman, Jeff; Padrón, María Fernanda; Kurz, Liliana; Rémignon, Hervé

    2017-01-01

    Protease activity present in liver cells with steatosis can be electrophoretically characterized. Zymographic techniques allow semi-quantitative results, successfully detecting cathepsin and metalloprotease activity using polyacrylamide gels copolymerized with gelatin and quantified by densitometry. By using specific inhibitors, the identity of the proteases can be confirmed. 2D zymography allows the determination of both M r. and pI of the metalloprotease and cathepsin activity present in the homogenates. The analysis of liver proteases activities in force fed ducks may elucidate the mechanisms behind steatosis development.

  9. Reliability of tunnel angle in ACL reconstruction: two-dimensional versus three-dimensional guide technique.

    Science.gov (United States)

    Leiter, Jeff R S; de Korompay, Nevin; Macdonald, Lindsey; McRae, Sheila; Froese, Warren; Macdonald, Peter B

    2011-08-01

    To compare the reliability of tibial tunnel position and angle produced with a standard ACL guide (two-dimensional guide) or Howell 65° Guide (three-dimensional guide) in the coronal and sagittal planes. In the sagittal plane, the dependent variables were the angle of the tibial tunnel relative to the tibial plateau and the position of the tibial tunnel with respect to the most posterior aspect of the tibia. In the coronal plane, the dependent variables were the angle of the tunnel with respect to the medial joint line of the tibia and the medial and lateral placement of the tibial tunnel relative to the most medial aspect of the tibia. The position and angle of the tibial tunnel in the coronal and sagittal planes were determined from anteroposterior and lateral radiographs, respectively, taken 2-6 months postoperatively. The two-dimensional and three-dimensional guide groups included 28 and 24 sets of radiographs, respectively. Tibial tunnel position was identified, and tunnel angle measurements were completed. Multiple investigators measured the position and angle of the tunnel 3 times, at least 7 days apart. The angle of the tibial tunnel in the coronal plane using a two-dimensional guide (61.3 ± 4.8°) was more horizontal (P guide (64.7 ± 6.2°). The position of the tibial tunnel in the sagittal plane was more anterior (P guide group compared to the three-dimensional guide group (43.3 ± 2.9%). The Howell Tibial Guide allows for reliable placement of the tibial tunnel in the coronal plane at an angle of 65°. Tibial tunnels were within the anatomical footprint of the ACL with either technique. Future studies should investigate the effects of tibial tunnel angle on knee function and patient quality of life. Case-control retrospective comparative study, Level III.

  10. Comparative analysis of excretory-secretory antigens of Trichinella spiralis and Trichinella britovi muscle larvae by two-dimensional difference gel electrophoresis and immunoblotting.

    Science.gov (United States)

    Bien, Justyna; Näreaho, Anu; Varmanen, Pekka; Gozdzik, Katarzyna; Moskwa, Bozena; Cabaj, Wladyslaw; Nyman, Tuula A; Savijoki, Kirsi

    2012-02-11

    Trichinellosis is a zoonotic disease in humans caused by Trichinella spp. The present study was undertaken to discover excretory-secretory (E-S) proteins from T. spiralis and T. britovi muscle larvae (ML) that hold promise for species-specific diagnostics. To that end, the purified E-S proteins were analyzed by fluorescent two-dimensional difference gel electrophoresis (2-D DIGE) coupled with protein identification by liquid chromatography-tandem mass spectrometry (LC-MS/MS). To search for immunoreactive proteins that are specifically recognized by host antibodies the E-S proteins were subjected to two-dimensional (2-DE) immunoblotting with antisera derived from pigs experimentally infected with T. spiralis or T. britovi. According to 2-D DIGE analysis, a total of twenty-two proteins including potentially immunogenic proteins and proteins produced only by one of the two Trichinella species were subjected to LC-MS/MS for protein identification. From these proteins seventeen could be identified, of which many were identified in multiple spots, suggesting that they have undergone post-translational modification, possibly involving glycosylation and/or proteolysis. These proteins included 5'-nucleotidase, serine-type protease/proteinase, and p43 glycoprotein (gp43) as well as 49 kDa E-S protein (p49). Our findings also suggest that some of the commonly identified proteins were post-translationally modified to different extents, which in certain cases seemed to result in species-specific modification. Both commonly and specifically recognized immunoreactive proteins were identified by 2-DE immunoblotting; shared antigens were identified as gp43 and different protease variants, whereas those specific to T. britovi included multiple isoforms of the 5'-nucleotidase. Both 2-D DIGE and 2-DE immunoblotting approaches indicate that T. spiralis and T. britovi produce somewhat distinctive antigen profiles, which contain E-S antigens with potential as species-specific diagnostic

  11. Matching Two-dimensional Gel Electrophoresis' Spots

    DEFF Research Database (Denmark)

    Dos Anjos, António; AL-Tam, Faroq; Shahbazkia, Hamid Reza

    2012-01-01

    This paper describes an approach for matching Two-Dimensional Electrophoresis (2-DE) gels' spots, involving the use of image registration. The number of false positive matches produced by the proposed approach is small, when compared to academic and commercial state-of-the-art approaches. This ar...

  12. Rational solutions to two- and one-dimensional multicomponent Yajima–Oikawa systems

    International Nuclear Information System (INIS)

    Chen, Junchao; Chen, Yong; Feng, Bao-Feng; Maruno, Ken-ichi

    2015-01-01

    Exact explicit rational solutions of two- and one-dimensional multicomponent Yajima–Oikawa (YO) systems, which contain multi-short-wave components and single long-wave one, are presented by using the bilinear method. For two-dimensional system, the fundamental rational solution first describes the localized lumps, which have three different patterns: bright, intermediate and dark states. Then, rogue waves can be obtained under certain parameter conditions and their behaviors are also classified to above three patterns with different definition. It is shown that the simplest (fundamental) rogue waves are line localized waves which arise from the constant background with a line profile and then disappear into the constant background again. In particular, two-dimensional intermediate and dark counterparts of rogue wave are found with the different parameter requirements. We demonstrate that multirogue waves describe the interaction of several fundamental rogue waves, in which interesting curvy wave patterns appear in the intermediate times. Different curvy wave patterns form in the interaction of different types fundamental rogue waves. Higher-order rogue waves exhibit the dynamic behaviors that the wave structures start from lump and then retreat back to it, and this transient wave possesses the patterns such as parabolas. Furthermore, different states of higher-order rogue wave result in completely distinguishing lumps and parabolas. Moreover, one-dimensional rogue wave solutions with three states are constructed through the further reduction. Specifically, higher-order rogue wave in one-dimensional case is derived under the parameter constraints. - Highlights: • Exact explicit rational solutions of two-and one-dimensional multicomponent Yajima–Oikawa systems. • Two-dimensional rogue wave contains three different patterns: bright, intermediate and dark states. • Multi- and higher-order rogue waves exhibit distinct dynamic behaviors in two-dimensional case

  13. Two-dimensional sensitivity calculation code: SENSETWO

    International Nuclear Information System (INIS)

    Yamauchi, Michinori; Nakayama, Mitsuo; Minami, Kazuyoshi; Seki, Yasushi; Iida, Hiromasa.

    1979-05-01

    A SENSETWO code for the calculation of cross section sensitivities with a two-dimensional model has been developed, on the basis of first order perturbation theory. It uses forward neutron and/or gamma-ray fluxes and adjoint fluxes obtained by two-dimensional discrete ordinates code TWOTRAN-II. The data and informations of cross sections, geometry, nuclide density, response functions, etc. are transmitted to SENSETWO by the dump magnetic tape made in TWOTRAN calculations. The required input for SENSETWO calculations is thus very simple. The SENSETWO yields as printed output the cross section sensitivities for each coarse mesh zone and for each energy group, as well as the plotted output of sensitivity profiles specified by the input. A special feature of the code is that it also calculates the reaction rate with the response function used as the adjoint source in TWOTRAN adjoint calculation and the calculated forward flux from the TWOTRAN forward calculation. (author)

  14. High-velocity two-phase flow two-dimensional modeling

    International Nuclear Information System (INIS)

    Mathes, R.; Alemany, A.; Thilbault, J.P.

    1995-01-01

    The two-phase flow in the nozzle of a LMMHD (liquid metal magnetohydrodynamic) converter has been studied numerically and experimentally. A two-dimensional model for two-phase flow has been developed including the viscous terms (dragging and turbulence) and the interfacial mass, momentum and energy transfer between the phases. The numerical results were obtained by a finite volume method based on the SIMPLE algorithm. They have been verified by an experimental facility using air-water as a simulation pair and a phase Doppler particle analyzer for velocity and droplet size measurement. The numerical simulation of a lithium-cesium high-temperature pair showed that a nearly homogeneous and isothermal expansion of the two phases is possible with small pressure losses and high kinetic efficiencies. In the throat region a careful profiling is necessary to reduce the inertial effects on the liquid velocity field

  15. Establishment of the optimum two-dimensional electrophoresis system of ovine ovarian tissue.

    Science.gov (United States)

    Jia, J L; Zhang, L P; Wu, J P; Wang, J; Ding, Q

    2014-08-26

    Lambing performance of sheep is the most important economic trait and is regarded as a critic factoring affecting the productivity in sheep industry. Ovary plays the most roles in lambing trait. To establish the optimum two-dimensional electrophoresis system (2-DE) of ovine ovarian tissue, the common protein extraction methods of animal tissue (trichloroacetic acid/acetone precipitation and direct schizolysis methods) were used to extract ovine ovarian protein, and 17-cm nonlinear immobilized PH 3-10 gradient strips were used for 2-DE. The sample handling, loading quantity of the protein sample, and isoelectric focusing (IEF) steps were manipulated and optimized in this study. The results indicate that the direct schizolysis III method, a 200-μg loading quantity of the protein sample, and IEF steps II (20°C active hydration, 14 h→500 V, 1 h→1000 V 1 h→1000-9000 V, 6 h→80,000 VH→500 V 24 h) are optimal for 2-DE analysis of ovine ovarian tissue. Therefore, ovine ovarian tissue proteomics 2-DE was preliminarily established by the optimized conditions in this study; meanwhile, the conditions identified herein could provide a reference for ovarian sample preparation and 2-DE using tissues from other animals.

  16. Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

    Energy Technology Data Exchange (ETDEWEB)

    Schultheis, M. [Université de Nice Sophia-Antipolis, CNRS, Observatoire de Côte d' Azur, Laboratoire Lagrange, 06304 Nice Cedex 4 (France); Zasowski, G. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Allende Prieto, C. [Instituto de Astrofísica de Canarias, Calle Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Anders, F.; Chiappini, C. [Leibniz-Institut für Astrophysik Potsdam (AIP), D-14482 Potsdam (Germany); Beaton, R. L.; García Pérez, A. E.; Majewski, S. R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Beers, T. C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Bizyaev, D. [Apache Point Observatory, Sunspot, NM 88349 (United States); Frinchaboy, P. M. [Department of Physics and Astronomy, Texas Christian University, TCU Box 298840, Fort Worth, TX 76129 (United States); Ge, J. [Astronomy Department, University of Florida, Gainesville, FL 32611 (United States); Hearty, F.; Schneider, D. P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Holtzman, J. [New Mexico State University, Las Cruces, NM 88003 (United States); Muna, D. [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Nidever, D. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Shetrone, M., E-mail: mathias.schultheis@oca.eu, E-mail: gail.zasowski@gmail.com [McDonald Observatory, The University of Texas at Austin, Austin, TX 78712 (United States)

    2014-07-01

    Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.

  17. Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

    International Nuclear Information System (INIS)

    Schultheis, M.; Zasowski, G.; Allende Prieto, C.; Anders, F.; Chiappini, C.; Beaton, R. L.; García Pérez, A. E.; Majewski, S. R.; Beers, T. C.; Bizyaev, D.; Frinchaboy, P. M.; Ge, J.; Hearty, F.; Schneider, D. P.; Holtzman, J.; Muna, D.; Nidever, D.; Shetrone, M.

    2014-01-01

    Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmospheric parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.

  18. Two dimensional unstable scar statistics.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Kotulski, Joseph Daniel; Lee, Kelvin S. H. (ITT Industries/AES Los Angeles, CA)

    2006-12-01

    This report examines the localization of time harmonic high frequency modal fields in two dimensional cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This paper examines the enhancements for these unstable orbits when the opposing mirrors are both convex and concave. In the latter case the construction includes the treatment of interior foci.

  19. Expression of Raf kinase inhibitor protein in human hepatoma tissues by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight methods.

    Science.gov (United States)

    Tsao, D A; Shiau, Y F; Tseng, C S; Chang, H R

    2016-01-01

    Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor-specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. Materials and Mehtods: In this study, we use two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to observe proteome alterations of 12 tissue pairs isolated from HCC patients: Normal and tumorous tissue. Comparing the tissue types with each other, 40 protein spots corresponding to fifteen differentially expressed between normal and cancer part of HCC patients. Raf kinase inhibitor protein (RKIP), an inhibitor of Raf-mediated activation of mitogen-activated protein kinase/extracellular signal-regulated kinase, may play an important role in cancer metastasis and cell proliferation and migration of human hepatoma cells. RKIP may be considered as a marker for HCC, because its expression level changes considerably in HCC compared with normal tissue. In addition, we used the methods of Western blotting and real time-polymerase chain reaction to analysis the protein expression and gene expression of RKIP. The result showed RKIP protein and gene expression in tumor part liver tissues of HCC patient is lower than peritumorous non-neoplastic liver tissue of the corresponding HCC samples. These results strongly suggest that RKIP may be considered to be a marker for HCC and RKIP are down-regulated in liver cancer cell.

  20. Sources of variability among replicate samples separated by two-dimensional gel electrophoresis.

    Science.gov (United States)

    Bland, Alison M; Janech, Michael G; Almeida, Jonas S; Arthur, John M

    2010-04-01

    Two-dimensional gel electrophoresis (2DE) offers high-resolution separation for intact proteins. However, variability in the appearance of spots can limit the ability to identify true differences between conditions. Variability can occur at a number of levels. Individual samples can differ because of biological variability. Technical variability can occur during protein extraction, processing, or storage. Another potential source of variability occurs during analysis of the gels and is not a result of any of the causes of variability named above. We performed a study designed to focus only on the variability caused by analysis. We separated three aliquots of rat left ventricle and analyzed differences in protein abundance on the replicate 2D gels. As the samples loaded on each gel were identical, differences in protein abundance are caused by variability in separation or interpretation of the gels. Protein spots were compared across gels by quantile values to determine differences. Fourteen percent of spots had a maximum difference in intensity of 0.4 quantile values or more between replicates. We then looked individually at the spots to determine the cause of differences between the measured intensities. Reasons for differences were: failure to identify a spot (59%), differences in spot boundaries (13%), difference in the peak height (6%), and a combination of these factors (21). This study demonstrates that spot identification and characterization make major contributions to variability seen with 2DE. Methods to highlight why measured protein spot abundance is different could reduce these errors.

  1. Superhydrophobic nanostructured ZnO thin films on aluminum alloy substrates by electrophoretic deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Sarkar, D.K., E-mail: dsarkar@uqac.ca; Chen, X-Grant

    2015-02-01

    Graphical abstract: - Highlights: • Fabrication of superhydrophobic ZnO thin films surfaces by electrophoretic deposition process on aluminum substrates. • Effect of bath temperature on the physical and superhydrophobic properties of thin films. • The water contact angle of 155° ± 3 with roll off property has been observed on the film that was grown at bath temperatures of 50 °C. • The activation energy for electrophoretic deposition of SA-functionalized ZnO nanoparticle is calculated to be 0.50 eV. - Abstract: Superhydrophobic thin films have been fabricated on aluminum alloy substrates by electrophoretic deposition (EPD) process using stearic acid (SA) functionalized zinc oxide (ZnO) nanoparticles suspension in alcohols at varying bath temperatures. The deposited thin films have been characterized using both X-ray diffraction (XRD) and infrared (IR) spectroscopy and it is found that the films contain low surface energy zinc stearate and ZnO nanoparticles. It is also observed that the atomic percentage of Zn and O, roughness and water contact angle of the thin films increase with the increase of the deposited bath temperature. Furthermore, the thin film deposited at 50 °C, having a roughness of 4.54 ± 0.23 μm, shows superhydrophobic properties providing a water contact angle of 155 ± 3° with rolling off properties. Also, the activation energy of electrophoretic deposition of stearic-acid-functionalized ZnO nanoparticles is calculated to be 0.5 eV.

  2. Temperature maxima in stable two-dimensional shock waves

    International Nuclear Information System (INIS)

    Kum, O.; Hoover, W.G.; Hoover, C.G.

    1997-01-01

    We use molecular dynamics to study the structure of moderately strong shock waves in dense two-dimensional fluids, using Lucy pair potential. The stationary profiles show relatively broad temperature maxima, for both the longitudinal and the average kinetic temperatures, just as does Mott-Smith model for strong shock waves in dilute three-dimensional gases. copyright 1997 The American Physical Society

  3. Resolution of G(s)alpha and G(q)alpha/G(11)alpha proteins in membrane domains by two-dimensional electrophoresis: the effect of long-term agonist stimulation.

    Science.gov (United States)

    Matousek, P; Novotný, J; Svoboda, P

    2004-01-01

    Low-density membrane-domain fractions were prepared from S49 lymphoma cells and clone e2m11 of HEK293 cells expressing a large number of thyrotropin-releasing hormone receptor (TRH-R) and G(11)alpha by flotation on sucrose density gradients. The intact cell structure was broken by detergent-extraction, alkaline-treatment or drastic homogenization. Three types of low-density membranes were resolved by two-dimensional electrophoresis and analyzed for G(s)alpha (S49) or G(q)alpha/G11) (e2m11) content. Four individual immunoblot signals of Gsalpha protein were identified in S49 lymphoma cells indicating complete resolution of the long G(s)alpha L+/-ser and short G(s)alpha S+/-ser variants of G(s)alpha. All these were diminished by prolonged agonist (isoprenaline) stimulation. In e2m11-HEK cells, five different immunoblot signals were detected indicating post-translational modification of G proteins of G(q)alpha/G(11)alpha family. The two major spots corresponding to exogenously (over)expressed G(11)alpha and endogenous G(q)alpha were reduced; the minor spots diminished by hormonal stimulation. Parallel analysis by silver staining of the total protein content indicated that no major changes in protein composition occurred under these conditions. Our data thus indicate that agonist-stimulation of target cells results in down-regulation of all different members of G(s) and G(q)/G(11) families. This agonist-specific effect may be demonstrated in crude membrane as well as domain/raft preparations and it is not accompanied by changes in overall protein composition.

  4. Tuning spin transport across two-dimensional organometallic junctions

    Science.gov (United States)

    Liu, Shuanglong; Wang, Yun-Peng; Li, Xiangguo; Fry, James N.; Cheng, Hai-Ping

    2018-01-01

    We study via first-principles modeling and simulation two-dimensional spintronic junctions made of metal-organic frameworks consisting of two Mn-phthalocyanine ferromagnetic metal leads and semiconducting Ni-phthalocyanine channels of various lengths. These systems exhibit a large tunneling magnetoresistance ratio; the transmission functions of such junctions can be tuned using gate voltage by three orders of magnitude. We find that the origin of this drastic change lies in the orbital alignment and hybridization between the leads and the center electronic states. With physical insight into the observed on-off phenomenon, we predict a gate-controlled spin current switch based on two-dimensional crystallines and offer general guidelines for designing spin junctions using 2D materials.

  5. CORPORATE VALUATION USING TWO-DIMENSIONAL MONTE CARLO SIMULATION

    Directory of Open Access Journals (Sweden)

    Toth Reka

    2010-12-01

    Full Text Available In this paper, we have presented a corporate valuation model. The model combine several valuation methods in order to get more accurate results. To determine the corporate asset value we have used the Gordon-like two-stage asset valuation model based on the calculation of the free cash flow to the firm. We have used the free cash flow to the firm to determine the corporate market value, which was calculated with use of the Black-Scholes option pricing model in frame of the two-dimensional Monte Carlo simulation method. The combined model and the use of the two-dimensional simulation model provides a better opportunity for the corporate value estimation.

  6. Structural Insight on the Mechanism of Regulation of the MarR Family of Proteins: High-Resolution Crystal Structure of a Transcriptional Repressor from Methanobacterium thermoautotrophicum

    Energy Technology Data Exchange (ETDEWEB)

    Saridakis, Vivian; Shahinas, Dea; Xu, Xiaohui; Christendat, Dinesh (York); (Toronto); (CG)

    2008-03-31

    Transcriptional regulators belonging to the MarR family are characterized by a winged-helix DNA binding domain. These transcriptional regulators regulate the efflux and influx of phenolic agents in bacteria and archaea. In Escherichia coli, MarR regulates the multiple antibiotic resistance operon and its inactivation produces a multiple antibiotic resistance phenotype. In some organisms, active efflux of drug compounds will produce a drug resistance phenotype, whereas in other organisms, active influx of chlorinated hydrocarbons results in their rapid degradation. Although proteins in the MarR family are regulators of important biological processes, their mechanism of action is not well understood and structural information about how phenolic agents regulate the activity of these proteins is lacking. This article presents the three-dimensional structure of a protein of the MarR family, MTH313, in its apo form and in complex with salicylate, a known inactivator. A comparison of these two structures indicates that the mechanism of regulation involves a large conformational change in the DNA binding lobe. Electrophoretic mobility shift assay and biophysical analyses further suggest that salicylate inactivates MTH313 and prevents it from binding to its promoter region.

  7. Laser sheet dropsizing based on two-dimensional Raman and Mie scattering.

    Science.gov (United States)

    Malarski, Anna; Schürer, Benedikt; Schmitz, Ingo; Zigan, Lars; Flügel, Alexandre; Leipertz, Alfred

    2009-04-01

    The imaging and quantification of droplet sizes in sprays is a challenging task for optical scientists and engineers. Laser sheet dropsizing (LSDS) combines the two-dimensional information of two different optical processes, one that is proportional to the droplet volume and one that depends on the droplet surface, e.g., Mie scattering. Besides Mie scattering, here we use two-dimensional Raman scattering as the volume-dependent measurement technique. Two different calibration strategies are presented and discussed. Two-dimensional droplet size distributions in a spray have been validated in comparison with the results of point-resolved phase Doppler anemometry (PDA) measurements.

  8. Laser sheet dropsizing based on two-dimensional Raman and Mie scattering

    International Nuclear Information System (INIS)

    Malarski, Anna; Schuerer, Benedikt; Schmitz, Ingo; Zigan, Lars; Fluegel, Alexandre; Leipertz, Alfred

    2009-01-01

    The imaging and quantification of droplet sizes in sprays is a challenging task for optical scientists and engineers. Laser sheet dropsizing (LSDS) combines the two-dimensional information of two different optical processes, one that is proportional to the droplet volume and one that depends on the droplet surface, e.g., Mie scattering. Besides Mie scattering, here we use two-dimensional Raman scattering as the volume-dependent measurement technique. Two different calibration strategies are presented and discussed. Two-dimensional droplet size distributions in a spray have been validated in comparison with the results of point-resolved phase Doppler anemometry (PDA) measurements

  9. Survival rate of eukaryotic cells following electrophoretic nanoinjection

    OpenAIRE

    Simonis, Matthias; H?bner, Wolfgang; Wilking, Alice; Huser, Thomas; Hennig, Simon

    2017-01-01

    Insertion of foreign molecules such as functionalized fluorescent probes, antibodies, or plasmid DNA to living cells requires overcoming the plasma membrane barrier without harming the cell during the staining process. Many techniques such as electroporation, lipofection or microinjection have been developed to overcome the cellular plasma membrane, but they all result in reduced cell viability. A novel approach is the injection of cells with a nanopipette and using electrophoretic forces for...

  10. NMR studies of electrophoretic mobility in surfactant systems

    International Nuclear Information System (INIS)

    Conveney, F.M.; Strange, J.H.; Smith, A.L.; Smith, E.G.

    1989-01-01

    An experimental technique is described in which the flow of electrically charged micelles is measured in the presence of an applied electric field using an NMR technique. The method is used to determine the electrophoretic mobility at ambient temperature of a 5% aqueous solution of sodium dodecyl sulphate and is shown to provide a new technique for the study of electrophoresis in surfactant solutions. (author). 8 refs.; 4 figs

  11. Layered ceramic composites via control of electrophoretic deposition kinetics

    Czech Academy of Sciences Publication Activity Database

    Hadraba, Hynek; Drdlík, D.; Chlup, Zdeněk; Maca, K.; Dlouhý, Ivo; Cihlář, J.

    2013-01-01

    Roč. 33, č. 12 (2013), s. 2305-2312 ISSN 0955-2219 R&D Projects: GA ČR(CZ) GAP108/11/1644; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Alumina * Zirconia * Laminates * Electrophoretic deposition Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.307, year: 2013

  12. Two dimensional solid state NMR

    International Nuclear Information System (INIS)

    Kentgens, A.P.M.

    1987-01-01

    This thesis illustrates, by discussing some existing and newly developed 2D solid state experiments, that two-dimensional NMR of solids is a useful and important extension of NMR techniques. Chapter 1 gives an overview of spin interactions and averaging techniques important in solid state NMR. As 2D NMR is already an established technique in solutions, only the basics of two dimensional NMR are presented in chapter 2, with an emphasis on the aspects important for solid spectra. The following chapters discuss the theoretical background and applications of specific 2D solid state experiments. An application of 2D-J resolved NMR, analogous to J-resolved spectroscopy in solutions, to natural rubber is given in chapter 3. In chapter 4 the anisotropic chemical shift is mapped out against the heteronuclear dipolar interaction to obtain information about the orientation of the shielding tensor in poly-(oxymethylene). Chapter 5 concentrates on the study of super-slow molecular motions in polymers using a variant of the 2D exchange experiment developed by us. Finally chapter 6 discusses a new experiment, 2D nutation NMR, which makes it possible to study the quadrupole interaction of half-integer spins. 230 refs.; 48 figs.; 8 tabs

  13. Effect of triiodothyronine on rat liver chromatin protein kinase

    International Nuclear Information System (INIS)

    Kruh, J.; Tichonicky, L.

    1976-01-01

    1) Injection of triiodothyronine to rats stimulates protein kinase activity in liver chromatin nonhistone proteins. A significant increase was found after two daily injections. A 4-fold increase was observed with the purified enzyme after eight daily injections of the hormone. No variations were observed in cytosol protein kinase activity. Electrophoretic pattern, effect of heat denaturation, effect of p-hydroxymercuribenzoate seem to indicate that the enzyme present in treated rats is not identical to the enzyme in control animals, which suggests that thyroid hormone has induced nuclear protein kinase. Diiodothyronine, 3, 3', 5'-triiodothyronine have no effect on protein kinase. 2) Chromatin non-histone proteins isolated from rats injected with triiodothyronine incorporated more 32 P when incubated with [γ- 32 P]ATP than the chromatin proteins from untreated rats. Thyroidectomy reduced the in vitro 32 P incorporation. It is suggested that some of the biological activity of thyroid hormone could be mediated through its effect on chromatin non-histone proteins. (orig.) [de

  14. Three-dimensional carbon nanotube networks with a supported nickel oxide nanonet for high-performance supercapacitors.

    Science.gov (United States)

    Wu, Mao-Sung; Zheng, Yo-Ru; Lin, Guan-Wei

    2014-08-04

    A three-dimensional porous carbon nanotube film with a supported NiO nanonet was prepared by simple electrophoretic deposition and hydrothermal synthesis, which could deliver a high specific capacitance of 1511 F g(-1) at a high discharge current of 50 A g(-1) due to the significantly improved transport of the electrolyte and electrons.

  15. Automated Processing of Two-Dimensional Correlation Spectra

    Science.gov (United States)

    Sengstschmid; Sterk; Freeman

    1998-04-01

    An automated scheme is described which locates the centers of cross peaks in two-dimensional correlation spectra, even under conditions of severe overlap. Double-quantum-filtered correlation (DQ-COSY) spectra have been investigated, but the method is also applicable to TOCSY and NOESY spectra. The search criterion is the intrinsic symmetry (or antisymmetry) of cross-peak multiplets. An initial global search provides the preliminary information to build up a two-dimensional "chemical shift grid." All genuine cross peaks must be centered at intersections of this grid, a fact that reduces the extent of the subsequent search program enormously. The program recognizes cross peaks by examining the symmetry of signals in a test zone centered at a grid intersection. This "symmetry filter" employs a "lowest value algorithm" to discriminate against overlapping responses from adjacent multiplets. A progressive multiplet subtraction scheme provides further suppression of overlap effects. The processed two-dimensional correlation spectrum represents cross peaks as points at the chemical shift coordinates, with some indication of their relative intensities. Alternatively, the information is presented in the form of a correlation table. The authenticity of a given cross peak is judged by a set of "confidence criteria" expressed as numerical parameters. Experimental results are presented for the 400-MHz double-quantum-filtered COSY spectrum of 4-androsten-3,17-dione, a case where there is severe overlap. Copyright 1998 Academic Press.

  16. Sums of two-dimensional spectral triples

    DEFF Research Database (Denmark)

    Christensen, Erik; Ivan, Cristina

    2007-01-01

    construct a sum of two dimensional modules which reflects some aspects of the topological dimensions of the compact metric space, but this will only give the metric back approximately. At the end we make an explicit computation of the last module for the unit interval in. The metric is recovered exactly...

  17. New hybrid lead iodides: From one-dimensional chain to two-dimensional layered perovskite structure

    International Nuclear Information System (INIS)

    Xiong, Kecai; Liu, Wei; Teat, Simon J.; An, Litao; Wang, Hao; Emge, Thomas J.; Li, Jing

    2015-01-01

    Two new hybrid lead halides (H 2 BDA)[PbI 4 ] (1) (H 2 BDA=1,4-butanediammonium dication) and (HNPEIM)[PbI 3 ] (2) (HNPEIM=N-​phenyl-ethanimidamidine cation) have been synthesized and structurally characterized. X-ray diffraction analyses reveal that compound 1 features a two-dimensional corner-sharing perovskite layer whereas compound 2 contains one-dimensional edge-sharing double chains. The N-​phenyl-ethanimidamidine cation within compound 2 was generated in-situ under solvothermal conditions. The optical absorption spectra collected at room temperature suggest that both compounds are semiconductors having direct band gaps, with estimated values of 2.64 and 2.73 eV for 1 and 2, respectively. Results from the density functional theory (DFT) calculations are consistent with the experimental data. Density of states (DOS) analysis reveals that in both compounds 1 and 2, the energy states in the valence band maximum region are iodine 5p atomic orbitals with a small contribution from lead 6s, while in the region of conduction band minimum, the major contributions are from the inorganic (Pb 6p atomic orbitals) and organic components (C and N 2p atomic orbitals) in compound 1 and 2, respectively. - Graphical abstract: Two new hybrid lead halides built on one-dimensional edge-sharing double chains and two-dimensional corner-sharing perovskite layers are synthesized and their structural and electronic properties are analyzed. - Highlights: • Two new hybrid lead iodides are designed, synthesized, and characterized. • They are closely related to, but different from, perovskite structures. • The electronic properties of both compounds are analyzed by DFT calculations

  18. New hybrid lead iodides: From one-dimensional chain to two-dimensional layered perovskite structure

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Kecai; Liu, Wei [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Teat, Simon J. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); An, Litao; Wang, Hao; Emge, Thomas J. [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States); Li, Jing, E-mail: jingli@rutgers.edu [Department of Chemistry and Chemical Biology, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854 (United States)

    2015-10-15

    Two new hybrid lead halides (H{sub 2}BDA)[PbI{sub 4}] (1) (H{sub 2}BDA=1,4-butanediammonium dication) and (HNPEIM)[PbI{sub 3}] (2) (HNPEIM=N-​phenyl-ethanimidamidine cation) have been synthesized and structurally characterized. X-ray diffraction analyses reveal that compound 1 features a two-dimensional corner-sharing perovskite layer whereas compound 2 contains one-dimensional edge-sharing double chains. The N-​phenyl-ethanimidamidine cation within compound 2 was generated in-situ under solvothermal conditions. The optical absorption spectra collected at room temperature suggest that both compounds are semiconductors having direct band gaps, with estimated values of 2.64 and 2.73 eV for 1 and 2, respectively. Results from the density functional theory (DFT) calculations are consistent with the experimental data. Density of states (DOS) analysis reveals that in both compounds 1 and 2, the energy states in the valence band maximum region are iodine 5p atomic orbitals with a small contribution from lead 6s, while in the region of conduction band minimum, the major contributions are from the inorganic (Pb 6p atomic orbitals) and organic components (C and N 2p atomic orbitals) in compound 1 and 2, respectively. - Graphical abstract: Two new hybrid lead halides built on one-dimensional edge-sharing double chains and two-dimensional corner-sharing perovskite layers are synthesized and their structural and electronic properties are analyzed. - Highlights: • Two new hybrid lead iodides are designed, synthesized, and characterized. • They are closely related to, but different from, perovskite structures. • The electronic properties of both compounds are analyzed by DFT calculations.

  19. Pair Interaction of Dislocations in Two-Dimensional Crystals

    Science.gov (United States)

    Eisenmann, C.; Gasser, U.; Keim, P.; Maret, G.; von Grünberg, H. H.

    2005-10-01

    The pair interaction between crystal dislocations is systematically explored by analyzing particle trajectories of two-dimensional colloidal crystals measured by video microscopy. The resulting pair energies are compared to Monte Carlo data and to predictions derived from the standard Hamiltonian of the elastic theory of dislocations. Good agreement is found with respect to the distance and temperature dependence of the interaction potential, but not regarding the angle dependence where discrete lattice effects become important. Our results on the whole confirm that the dislocation Hamiltonian allows a quantitative understanding of the formation and interaction energies of dislocations in two-dimensional crystals.

  20. Three-dimensional versus two-dimensional vision in laparoscopy

    DEFF Research Database (Denmark)

    Sørensen, Stine D; Savran, Mona Meral; Konge, Lars

    2016-01-01

    were cohort size and characteristics, skill trained or operation performed, instrument used, outcome measures, and conclusions. Two independent authors performed the search and data extraction. RESULTS: Three hundred and forty articles were screened for eligibility, and 31 RCTs were included...... through a two-dimensional (2D) projection on a monitor, which results in loss of depth perception. To counter this problem, 3D imaging for laparoscopy was developed. A systematic review of the literature was performed to assess the effect of 3D laparoscopy. METHODS: A systematic search of the literature...... in the review. Three trials were carried out in a clinical setting, and 28 trials used a simulated setting. Time was used as an outcome measure in all of the trials, and number of errors was used in 19 out of 31 trials. Twenty-two out of 31 trials (71 %) showed a reduction in performance time, and 12 out of 19...

  1. Electrophoretic deposition of composite halloysite nanotube–hydroxyapatite–hyaluronic acid films

    Energy Technology Data Exchange (ETDEWEB)

    Deen, I. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Zhitomirsky, I., E-mail: zhitom@mcmaster.ca [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2014-02-15

    Highlights: ► Composite halloysite nanotubes–hydroxyapatite–hyaluronic acid films were prepared. ► Electrophoretic deposition method was used for deposition. ► Natural hyaluronic acid was used as a dispersing, charging and film forming agent. ► Film composition and deposition yield can be varied. ► The films can be used for biomedical implants with controlled release of drugs. -- Abstract: Electrophoretic deposition method has been developed for the deposition of biocomposite films containing halloysite nanotubes (HNTs), hydroxyapatite (HA) and hyaluronic acid. The method is based on the use of natural hyaluronate biopolymer as a dispersing and charging agent for HNT and HA and film forming agent for the fabrication of the composite films. The deposition kinetics was studied by the quartz crystal microbalance method. The composite films were studied by X-ray diffraction, thermogravimetric analysis, differential thermal analysis and electron microscopy. The composite films are promising materials for the fabrication of biomedical implants with advanced functional properties.

  2. Electrophoretic deposition of composite halloysite nanotube–hydroxyapatite–hyaluronic acid films

    International Nuclear Information System (INIS)

    Deen, I.; Zhitomirsky, I.

    2014-01-01

    Highlights: ► Composite halloysite nanotubes–hydroxyapatite–hyaluronic acid films were prepared. ► Electrophoretic deposition method was used for deposition. ► Natural hyaluronic acid was used as a dispersing, charging and film forming agent. ► Film composition and deposition yield can be varied. ► The films can be used for biomedical implants with controlled release of drugs. -- Abstract: Electrophoretic deposition method has been developed for the deposition of biocomposite films containing halloysite nanotubes (HNTs), hydroxyapatite (HA) and hyaluronic acid. The method is based on the use of natural hyaluronate biopolymer as a dispersing and charging agent for HNT and HA and film forming agent for the fabrication of the composite films. The deposition kinetics was studied by the quartz crystal microbalance method. The composite films were studied by X-ray diffraction, thermogravimetric analysis, differential thermal analysis and electron microscopy. The composite films are promising materials for the fabrication of biomedical implants with advanced functional properties

  3. Self-focusing instability of two-dimensional solitons and vortices

    DEFF Research Database (Denmark)

    Kuznetsov, E.A.; Juul Rasmussen, J.

    1995-01-01

    The instability of two-dimensional solitons and vortices is demonstrated in the framework of the three-dimensional nonlinear Schrodinger equation (NLSE). The instability can be regarded as the analog of the Kadomtsev-Petviashvili instability [B. B. Kadomtsev and V. I. Petviashvili, Sov. Phys. Dokl...

  4. Three-dimensional protein structure prediction: Methods and computational strategies.

    Science.gov (United States)

    Dorn, Márcio; E Silva, Mariel Barbachan; Buriol, Luciana S; Lamb, Luis C

    2014-10-12

    A long standing problem in structural bioinformatics is to determine the three-dimensional (3-D) structure of a protein when only a sequence of amino acid residues is given. Many computational methodologies and algorithms have been proposed as a solution to the 3-D Protein Structure Prediction (3-D-PSP) problem. These methods can be divided in four main classes: (a) first principle methods without database information; (b) first principle methods with database information; (c) fold recognition and threading methods; and (d) comparative modeling methods and sequence alignment strategies. Deterministic computational techniques, optimization techniques, data mining and machine learning approaches are typically used in the construction of computational solutions for the PSP problem. Our main goal with this work is to review the methods and computational strategies that are currently used in 3-D protein prediction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Alpha1-acid glycoprotein post-translational modifications: a comparative two dimensional electrophoresis based analysis

    Directory of Open Access Journals (Sweden)

    P. Roncada

    2010-04-01

    Full Text Available Alpha1-acid glycoprotein (AGP is an immunomodulatory protein expressed by hepatocytes in response to the systemic reaction that follows tissue damage caused by inflammation, infection or trauma. A proteomic approach based on two dimensional electrophoresis, immunoblotting and staining of 2DE gels with dyes specific for post-translational modifications (PTMs such as glycosylation and phosphorylation has been used to evaluate the differential interspecific protein expression of AGP purified from human, bovine and ovine sera. By means of these techniques, several isoforms have been identified in the investigated species: they have been found to change both with regard to the number of isoforms expressed under physiological condition and with regard to the quality of PTMs (i.e. different oligosaccharidic chains, presence/absence of phosphorilations. In particular, it is suggested that bovine serum AGP may have one of the most complex pattern of PTMs among serum proteins of mammals studied so far.

  6. Secretome analysis of Aspergillus fumigatus reveals Asp-hemolysin as a major secreted protein.

    Science.gov (United States)

    Wartenberg, Dirk; Lapp, Katrin; Jacobsen, Ilse D; Dahse, Hans-Martin; Kniemeyer, Olaf; Heinekamp, Thorsten; Brakhage, Axel A

    2011-11-01

    Surface-associated and secreted proteins represent primarily exposed components of Aspergillus fumigatus during host infection. Several secreted proteins are known to be involved in defense mechanisms or immune evasion, thus, probably contributing to pathogenicity. Furthermore, several secreted antigens were identified as possible biomarkers for the verification of diseases caused by Aspergillus species. Nevertheless, there is only limited knowledge about the composition of the secretome and about molecular functions of particular proteins. To identify secreted proteins potentially essential for virulence, the core secretome of A. fumigatus grown in minimal medium was determined. Two-dimensional gel electrophoretic separation and subsequent MALDI-TOF-MS/MS analyses resulted in the identification of 64 different proteins. Additionally, secretome analyses of A. fumigatus utilizing elastin, collagen or keratin as main carbon and nitrogen source were performed. Thereby, the alkaline serine protease Alp1 was identified as the most abundant protein and hence presumably represents an important protease during host infection. Interestingly, the Asp-hemolysin (Asp-HS), which belongs to the protein family of aegerolysins and which was often suggested to be involved in fungal virulence, was present in the secretome under all growth conditions tested. In addition, a second, non-secreted protein with an aegerolysin domain annotated as Asp-hemolysin-like (HS-like) protein can be found to be encoded in the genome of A. fumigatus. Generation and analysis of Asp-HS and HS-like deletion strains revealed no differences in phenotype compared to the corresponding wild-type strain. Furthermore, hemolysis and cytotoxicity was not altered in both single-deletion and double-deletion mutants lacking both aegerolysin genes. All mutant strains showed no attenuation in virulence in a mouse infection model for invasive pulmonary aspergillosis. Overall, this study provides a comprehensive

  7. Quasi-two-dimensional thermoelectricity in SnSe

    Science.gov (United States)

    Tayari, V.; Senkovskiy, B. V.; Rybkovskiy, D.; Ehlen, N.; Fedorov, A.; Chen, C.-Y.; Avila, J.; Asensio, M.; Perucchi, A.; di Pietro, P.; Yashina, L.; Fakih, I.; Hemsworth, N.; Petrescu, M.; Gervais, G.; Grüneis, A.; Szkopek, T.

    2018-01-01

    Stannous selenide is a layered semiconductor that is a polar analog of black phosphorus and of great interest as a thermoelectric material. Unusually, hole doped SnSe supports a large Seebeck coefficient at high conductivity, which has not been explained to date. Angle-resolved photoemission spectroscopy, optical reflection spectroscopy, and magnetotransport measurements reveal a multiple-valley valence-band structure and a quasi-two-dimensional dispersion, realizing a Hicks-Dresselhaus thermoelectric contributing to the high Seebeck coefficient at high carrier density. We further demonstrate that the hole accumulation layer in exfoliated SnSe transistors exhibits a field effect mobility of up to 250 cm2/V s at T =1.3 K . SnSe is thus found to be a high-quality quasi-two-dimensional semiconductor ideal for thermoelectric applications.

  8. Acoustic phonon emission by two dimensional plasmons

    International Nuclear Information System (INIS)

    Mishonov, T.M.

    1990-06-01

    Acoustic wave emission of the two dimensional plasmons in a semiconductor or superconductor microstructure is investigated by using the phenomenological deformation potential within the jellium model. The plasmons are excited by the external electromagnetic (e.m.) field. The power conversion coefficient of e.m. energy into acoustic wave energy is also estimated. It is shown, the coherent transformation has a sharp resonance at the plasmon frequency of the two dimensional electron gas (2DEG). The incoherent transformation of the e.m. energy is generated by ohmic dissipation of 2DEG. The method proposed for coherent phonon beam generation can be very effective for high mobility 2DEG and for thin superconducting layers if the plasmon frequency ω is smaller than the superconducting gap 2Δ. (author). 21 refs, 1 fig

  9. Two- and three-dimensional CT evaluation of sacral and pelvic anomalies

    International Nuclear Information System (INIS)

    Kuhlman, J.E.; Fishman, E.K.; Magid, D.

    1988-01-01

    Pelvic anomalies are difficult to evaluate with standard techniques. Detailed knowledge of the existing pelvic structures and musculature is essential for successful repair. The authors evaluated 12 patients with complex malformations of the pelvis using two- and three-dimensional imaging. The anomalies included bladder exstrophy (n = 4), cloacal exstrophy (n = 1), duplicated and absent sacrum (n = 3), myelomeningoceles (n = 2), and diastrophic dwarfism (n = 2). The two-dimensional images consisted of sequential coronal and sagittal reconstructions that could be reviewed dynamically on screen. Three-dimensional images were generated on the Pixar imaging computer with use of volumetric rendering. Two- and three-dimensional CT proved complementary in the evaluation of pelvic anomalies, providing optimal information from transaxial CT data

  10. Two-dimensional Lorentz-Weyl anomaly and gravitational Chern-Simons theory

    International Nuclear Information System (INIS)

    Chamseddine, A.H.; Froehlich, J.

    1992-01-01

    Two-dimensional chiral fermions and bosons, more generally conformal blocks of two-dimensional conformal field theories, exhibit Weyl-, Lorentz- and mixed Lorentz-Weyl anomalies. A novel way of computing these anomalies for a system of chiral bosons of arbitrary conformal spin j is sketched. It is shown that the Lorentz- and mixed Lorentz-Weyl anomalies of these theories can be cancelled by the anomalies of a three-dimensional classical Chern-Simons action for the spin connection, expressed in terms of the dreibein field. Some tentative applications of this result to string theory are indicated. (orig.)

  11. Capillary electrophoretic analysis reveals subcellular binding between individual mitochondria and cytoskeleton

    Science.gov (United States)

    Kostal, Vratislav; Arriaga, Edgar A.

    2011-01-01

    Interactions between the cytoskeleton and mitochondria are essential for normal cellular function. An assessment of such interactions is commonly based on bulk analysis of mitochondrial and cytoskeletal markers present in a given sample, which assumes complete binding between these two organelle types. Such measurements are biased because they rarely account for non-bound ‘free’ subcellular species. Here we report on the use of capillary electrophoresis with dual laser induced fluorescence detection (CE-LIF) to identify, classify, count and quantify properties of individual binding events of mitochondria and cytoskeleton. Mitochondria were fluorescently labeled with DsRed2 while F-actin, a major cytoskeletal component, was fluorescently labeled with Alexa488-phalloidin. In a typical subcellular fraction of L6 myoblasts, 79% of mitochondrial events did not have detectable levels of F-actin, while the rest had on average ~2 zeptomole F-actin, which theoretically represents a ~ 2.5-μm long network of actin filaments per event. Trypsin treatment of L6 subcellular fractions prior to analysis decreased the fraction of mitochondrial events with detectable levels of F-actin, which is expected from digestion of cytoskeletal proteins on the surface of mitochondria. The electrophoretic mobility distributions of the individual events were also used to further distinguish between cytoskeleton-bound from cytoskeleton-free mitochondrial events. The CE-LIF approach described here could be further developed to explore cytoskeleton interactions with other subcellular structures, the effects of cytoskeleton destabilizing drugs, and the progression of viral infections. PMID:21309532

  12. Bayesian approach for peak detection in two-dimensional chromatography

    NARCIS (Netherlands)

    Vivó-Truyols, G.

    2012-01-01

    A new method for peak detection in two-dimensional chromatography is presented. In a first step, the method starts with a conventional one-dimensional peak detection algorithm to detect modulated peaks. In a second step, a sophisticated algorithm is constructed to decide which of the individual

  13. Energy Spectra of Vortex Distributions in Two-Dimensional Quantum Turbulence

    Directory of Open Access Journals (Sweden)

    Ashton S. Bradley

    2012-10-01

    Full Text Available We theoretically explore key concepts of two-dimensional turbulence in a homogeneous compressible superfluid described by a dissipative two-dimensional Gross-Pitaeveskii equation. Such a fluid supports quantized vortices that have a size characterized by the healing length ξ. We show that, for the divergence-free portion of the superfluid velocity field, the kinetic-energy spectrum over wave number k may be decomposed into an ultraviolet regime (k≫ξ^{-1} having a universal k^{-3} scaling arising from the vortex core structure, and an infrared regime (k≪ξ^{-1} with a spectrum that arises purely from the configuration of the vortices. The Novikov power-law distribution of intervortex distances with exponent -1/3 for vortices of the same sign of circulation leads to an infrared kinetic-energy spectrum with a Kolmogorov k^{-5/3} power law, which is consistent with the existence of an inertial range. The presence of these k^{-3} and k^{-5/3} power laws, together with the constraint of continuity at the smallest configurational scale k≈ξ^{-1}, allows us to derive a new analytical expression for the Kolmogorov constant that we test against a numerical simulation of a forced homogeneous, compressible, two-dimensional superfluid. The numerical simulation corroborates our analysis of the spectral features of the kinetic-energy distribution, once we introduce the concept of a clustered fraction consisting of the fraction of vortices that have the same sign of circulation as their nearest neighboring vortices. Our analysis presents a new approach to understanding two-dimensional quantum turbulence and interpreting similarities and differences with classical two-dimensional turbulence, and suggests new methods to characterize vortex turbulence in two-dimensional quantum fluids via vortex position and circulation measurements.

  14. Dynamics of vortex interactions in two-dimensional flows

    DEFF Research Database (Denmark)

    Juul Rasmussen, J.; Nielsen, A.H.; Naulin, V.

    2002-01-01

    The dynamics and interaction of like-signed vortex structures in two dimensional flows are investigated by means of direct numerical solutions of the two-dimensional Navier-Stokes equations. Two vortices with distributed vorticity merge when their distance relative to their radius, d/R-0l. is below...... a critical value, a(c). Using the Weiss-field, a(c) is estimated for vortex patches. Introducing an effective radius for vortices with distributed vorticity, we find that 3.3 ... is effectively producing small scale structures and the relation to the enstrophy "cascade" in developed 2D turbulence is discussed. The influence of finite viscosity on the merging is also investigated. Additionally, we examine vortex interactions on a finite domain, and discuss the results in connection...

  15. Two-dimensional atom localization via Raman-driven coherence

    Energy Technology Data Exchange (ETDEWEB)

    Rahmatullah,; Qamar, Sajid, E-mail: sajid_qamar@comsats.edu.pk

    2014-02-07

    A scheme for two-dimensional (2D) atom localization via Raman-driven coherence in a four-level diamond-configuration system is suggested. The atom interacts with two orthogonal standing-wave fields where each standing-wave field is constructed from the superposition of the two-standing wave fields along the corresponding directions. Due to the position-dependent atom–field interaction, the frequency of the spontaneously emitted photon carries the position information about the atom. We investigate the effect of the detunings and phase shifts associated with standing-wave fields. Unique position information of the single atom is obtained by properly adjusting the system parameters. This is an extension of our previous proposal for one-dimensional atom localization via Raman-driven coherence.

  16. Efficient processing of two-dimensional arrays with C or C++

    Science.gov (United States)

    Donato, David I.

    2017-07-20

    Because fast and efficient serial processing of raster-graphic images and other two-dimensional arrays is a requirement in land-change modeling and other applications, the effects of 10 factors on the runtimes for processing two-dimensional arrays with C and C++ are evaluated in a comparative factorial study. This study’s factors include the choice among three C or C++ source-code techniques for array processing; the choice of Microsoft Windows 7 or a Linux operating system; the choice of 4-byte or 8-byte array elements and indexes; and the choice of 32-bit or 64-bit memory addressing. This study demonstrates how programmer choices can reduce runtimes by 75 percent or more, even after compiler optimizations. Ten points of practical advice for faster processing of two-dimensional arrays are offered to C and C++ programmers. Further study and the development of a C and C++ software test suite are recommended.Key words: array processing, C, C++, compiler, computational speed, land-change modeling, raster-graphic image, two-dimensional array, software efficiency

  17. Proteomic Analysis of Bovine Pregnancy-specific Serum Proteins by 2D Fluorescence Difference Gel Electrophoresis

    Science.gov (United States)

    Lee, Jae Eun; Lee, Jae Young; Kim, Hong Rye; Shin, Hyun Young; Lin, Tao; Jin, Dong Il

    2015-01-01

    Two dimensional-fluorescence difference gel electrophoresis (2D DIGE) is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. The purpose of this study was to investigate bovine pregnancy-specific proteins in the proteome between bovine pregnant and non-pregnant serum using DIGE technique. Serums of 2 pregnant Holstein dairy cattle at day 21 after artificial insemination and those of 2 non-pregnant were used in this study. The pre-electrophoretic labeling of pregnant and non-pregnant serum proteins were mixed with Cy3 and Cy5 fluorescent dyes, respectively, and an internal standard was labeled with Cy2. Labeled proteins with Cy2, Cy3, and Cy5 were separated together in a single gel, and then were detected by fluorescence image analyzer. The 2D DIGE method using fluorescence CyDye DIGE flour had higher sensitivity than conventional 2D gel electrophoresis, and showed reproducible results. Approximately 1,500 protein spots were detected by 2D DIGE. Several proteins showed a more than 1.5-fold up and down regulation between non-pregnant and pregnant serum proteins. The differentially expressed proteins were identified by MALDI-TOF mass spectrometer. A total 16 protein spots were detected to regulate differentially in the pregnant serum, among which 7 spots were up-regulated proteins such as conglutinin precursor, modified bovine fibrinogen and IgG1, and 6 spots were down-regulated proteins such as hemoglobin, complement component 3, bovine fibrinogen and IgG2a three spots were not identified. The identified proteins demonstrate that early pregnant bovine serum may have several pregnancy-specific proteins, and these could be a valuable information for the development of pregnancy-diagnostic markers in early pregnancy bovine serum. PMID:25925056

  18. Proteomic Analysis of Bovine Pregnancy-specific Serum Proteins by 2D Fluorescence Difference Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Jae Eun Lee

    2015-06-01

    Full Text Available Two dimensional-fluorescence difference gel electrophoresis (2D DIGE is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. The purpose of this study was to investigate bovine pregnancy-specific proteins in the proteome between bovine pregnant and non-pregnant serum using DIGE technique. Serums of 2 pregnant Holstein dairy cattle at day 21 after artificial insemination and those of 2 non-pregnant were used in this study. The pre-electrophoretic labeling of pregnant and non-pregnant serum proteins were mixed with Cy3 and Cy5 fluorescent dyes, respectively, and an internal standard was labeled with Cy2. Labeled proteins with Cy2, Cy3, and Cy5 were separated together in a single gel, and then were detected by fluorescence image analyzer. The 2D DIGE method using fluorescence CyDye DIGE flour had higher sensitivity than conventional 2D gel electrophoresis, and showed reproducible results. Approximately 1,500 protein spots were detected by 2D DIGE. Several proteins showed a more than 1.5-fold up and down regulation between non-pregnant and pregnant serum proteins. The differentially expressed proteins were identified by MALDI-TOF mass spectrometer. A total 16 protein spots were detected to regulate differentially in the pregnant serum, among which 7 spots were up-regulated proteins such as conglutinin precursor, modified bovine fibrinogen and IgG1, and 6 spots were down-regulated proteins such as hemoglobin, complement component 3, bovine fibrinogen and IgG2a three spots were not identified. The identified proteins demonstrate that early pregnant bovine serum may have several pregnancy-specific proteins, and these could be a valuable information for the development of pregnancy-diagnostic markers in early pregnancy bovine serum.

  19. Dynamical class of a two-dimensional plasmonic Dirac system.

    Science.gov (United States)

    Silva, Érica de Mello

    2015-10-01

    A current goal in plasmonic science and technology is to figure out how to manage the relaxational dynamics of surface plasmons in graphene since its damping constitutes a hinder for the realization of graphene-based plasmonic devices. In this sense we believe it might be of interest to enlarge the knowledge on the dynamical class of two-dimensional plasmonic Dirac systems. According to the recurrence relations method, different systems are said to be dynamically equivalent if they have identical relaxation functions at all times, and such commonality may lead to deep connections between seemingly unrelated physical systems. We employ the recurrence relations approach to obtain relaxation and memory functions of density fluctuations and show that a two-dimensional plasmonic Dirac system at long wavelength and zero temperature belongs to the same dynamical class of standard two-dimensional electron gas and classical harmonic oscillator chain with an impurity mass.

  20. Two-dimensional microstrip detector for neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Oed, A [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Because of their robust design, gas microstrip detectors, which were developed at ILL, can be assembled relatively quickly, provided the prefabricated components are available. At the beginning of 1996, orders were received for the construction of three two-dimensional neutron detectors. These detectors have been completed. The detectors are outlined below. (author). 2 refs.

  1. Effect of acids and bases on electrophoretic deposition of

    Czech Academy of Sciences Publication Activity Database

    Cihlář, J.; Drdlík, D.; Cihlářová, Z.; Hadraba, Hynek

    2013-01-01

    Roč. 33, č. 10 (2013), s. 1885-1892 ISSN 0955-2219 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA ČR GD106/09/H035 Institutional support: RVO:68081723 Keywords : Electrophoretic deposition * Zirconia * Alumina * 2-Propanol * Electrosteric stabilization Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.307, year: 2013

  2. Two-dimensional transport of tokamak plasmas

    International Nuclear Information System (INIS)

    Hirshman, S.P.; Jardin, S.C.

    1979-01-01

    A reduced set of two-fluid transport equations is obtained from the conservation equations describing the time evolution of the differential particle number, entropy, and magnetic fluxes in an axisymmetric toroidal plasma with nested magnetic surfaces. Expanding in the small ratio of perpendicular to parallel mobilities and thermal conductivities yields as solubility constraints one-dimensional equations for the surface-averaged thermodynamic variables and magnetic fluxes. Since Ohm's law E +u x B =R', where R' accounts for any nonideal effects, only determines the particle flow relative to the diffusing magnetic surfaces, it is necessary to solve a single two-dimensional generalized differential equation, (partial/partialt) delpsi. (delp - J x B) =0, to find the absolute velocity of a magnetic surface enclosing a fixed toroidal flux. This equation is linear but nonstandard in that it involves flux surface averages of the unknown velocity. Specification of R' and the cross-field ion and electron heat fluxes provides a closed system of equations. A time-dependent coordinate transformation is used to describe the diffusion of plasma quantities through magnetic surfaces of changing shape

  3. Decoherence in two-dimensional quantum walks

    International Nuclear Information System (INIS)

    Oliveira, A. C.; Portugal, R.; Donangelo, R.

    2006-01-01

    We analyze the decoherence in quantum walks in two-dimensional lattices generated by broken-link-type noise. In this type of decoherence, the links of the lattice are randomly broken with some given constant probability. We obtain the evolution equation for a quantum walker moving on two-dimensional (2D) lattices subject to this noise, and we point out how to generalize for lattices in more dimensions. In the nonsymmetric case, when the probability of breaking links in one direction is different from the probability in the perpendicular direction, we have obtained a nontrivial result. If one fixes the link-breaking probability in one direction, and gradually increases the probability in the other direction from 0 to 1, the decoherence initially increases until it reaches a maximum value, and then it decreases. This means that, in some cases, one can increase the noise level and still obtain more coherence. Physically, this can be explained as a transition from a decoherent 2D walk to a coherent 1D walk

  4. Two- and three-dimensional evaluation of the acetabulum in the pediatric patient

    International Nuclear Information System (INIS)

    Magid, D.; Fishman, E.K.; Sponseller, P.D.

    1987-01-01

    Complex anatomic structures such as the hip and acetabulum are best evaluated with the use of two- and three-dimensional reconstruction techniques and standard transaxial CT data. CT scans of children with various hip pathologies, including congenital hip dislocation, slipped capital femoral epiphyses, hip dysplasias, dwarfism, and acetabular fractures, were reviewed to determine the value of two- and three-dimensional imaging. The advantages of two-dimensional imaging techniques (sequential coronal/sagittal reconstruction) and three-dimensional valumetric imaging techniques (using real-time video display) are illustrated with specific examples

  5. Equivalency of two-dimensional algebras

    International Nuclear Information System (INIS)

    Santos, Gildemar Carneiro dos; Pomponet Filho, Balbino Jose S.

    2011-01-01

    Full text: Let us consider a vector z = xi + yj over the field of real numbers, whose basis (i,j) satisfy a given algebra. Any property of this algebra will be reflected in any function of z, so we can state that the knowledge of the properties of an algebra leads to more general conclusions than the knowledge of the properties of a function. However structural properties of an algebra do not change when this algebra suffers a linear transformation, though the structural constants defining this algebra do change. We say that two algebras are equivalent to each other whenever they are related by a linear transformation. In this case, we have found that some relations between the structural constants are sufficient to recognize whether or not an algebra is equivalent to another. In spite that the basis transform linearly, the structural constants change like a third order tensor, but some combinations of these tensors result in a linear transformation, allowing to write the entries of the transformation matrix as function of the structural constants. Eventually, a systematic way to find the transformation matrix between these equivalent algebras is obtained. In this sense, we have performed the thorough classification of associative commutative two-dimensional algebras, and find that even non-division algebra may be helpful in solving non-linear dynamic systems. The Mandelbrot set was used to have a pictorial view of each algebra, since equivalent algebras result in the same pattern. Presently we have succeeded in classifying some non-associative two-dimensional algebras, a task more difficult than for associative one. (author)

  6. Comparison of two three-dimensional cephalometric analysis computer software.

    Science.gov (United States)

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-10-01

    Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

  7. Chimera patterns in two-dimensional networks of coupled neurons

    Science.gov (United States)

    Schmidt, Alexander; Kasimatis, Theodoros; Hizanidis, Johanne; Provata, Astero; Hövel, Philipp

    2017-03-01

    We discuss synchronization patterns in networks of FitzHugh-Nagumo and leaky integrate-and-fire oscillators coupled in a two-dimensional toroidal geometry. A common feature between the two models is the presence of fast and slow dynamics, a typical characteristic of neurons. Earlier studies have demonstrated that both models when coupled nonlocally in one-dimensional ring networks produce chimera states for a large range of parameter values. In this study, we give evidence of a plethora of two-dimensional chimera patterns of various shapes, including spots, rings, stripes, and grids, observed in both models, as well as additional patterns found mainly in the FitzHugh-Nagumo system. Both systems exhibit multistability: For the same parameter values, different initial conditions give rise to different dynamical states. Transitions occur between various patterns when the parameters (coupling range, coupling strength, refractory period, and coupling phase) are varied. Many patterns observed in the two models follow similar rules. For example, the diameter of the rings grows linearly with the coupling radius.

  8. Design of a rotational three-dimensional nonimaging device by a compensated two-dimensional design process.

    Science.gov (United States)

    Yang, Yi; Qian, Ke-Yuan; Luo, Yi

    2006-07-20

    A compensation process has been developed to design rotational three-dimensional (3D) nonimaging devices. By compensating the desired light distribution during a two-dimensional (2D) design process for an extended Lambertian source using a compensation coefficient, the meridian plane of a 3D device with good performance can be obtained. This method is suitable in many cases with fast calculation speed. Solutions to two kinds of optical design problems have been proposed, and the limitation of this compensated 2D design method is discussed.

  9. Study on two-dimensional induced signal readout of MRPC

    International Nuclear Information System (INIS)

    Wu Yucheng; Yue Qian; Li Yuanjing; Ye Jin; Cheng Jianping; Wang Yi; Li Jin

    2012-01-01

    A kind of two-dimensional readout electrode structure for the induced signal readout of MRPC has been studied in both simulation and experiments. Several MRPC prototypes are produced and a series of test experiments have been done to compare with the result of simulation, in order to verify the simulation model. The experiment results are in good agreement with those of simulation. This method will be used to design the two-dimensional signal readout mode of MRPC in the future work.

  10. Two-dimensional electronic femtosecond stimulated Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    Ogilvie J.P.

    2013-03-01

    Full Text Available We report two-dimensional electronic spectroscopy with a femtosecond stimulated Raman scattering probe. The method reveals correlations between excitation energy and excited state vibrational structure following photoexcitation. We demonstrate the method in rhodamine 6G.

  11. Stability of two-dimensional vorticity filaments

    International Nuclear Information System (INIS)

    Elhmaidi, D.; Provenzale, A.; Lili, T.; Babiano, A.

    2004-01-01

    We discuss the results of a numerical study on the stability of two-dimensional vorticity filaments around a circular vortex. We illustrate how the stability of the filaments depends on the balance between the strain associated with the far field of the vortex and the local vorticity of the filament, and we discuss an empirical criterion for filament stability

  12. Identification of DNA-binding proteins that interact with the 5'-flanking region of the human D-amino acid oxidase gene by pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry.

    Science.gov (United States)

    Tran, Diem Hong; Shishido, Yuji; Chung, Seong Pil; Trinh, Huong Thi Thanh; Yorita, Kazuko; Sakai, Takashi; Fukui, Kiyoshi

    2015-12-10

    D-Amino acid oxidase (DAO) is a flavoenzyme that metabolizes D-amino acids and is expected to be a promising therapeutic target of schizophrenia and glioblastoma. The study of DNA-binding proteins has yielded much information in the regulation of transcription and other biological processes. However, proteins interacting with DAO gene have not been elucidated. Our assessment of human DAO promoter activity using luciferase reporter system indicated the 5'-flanking region of this gene (-4289 bp from transcription initiation site) has a regulatory sequence for gene expression, which is regulated by multi-protein complexes interacting with this region. By using pull-down assay coupled with two-dimensional gel electrophoresis and mass spectrometry, we identified six proteins binding to the 5'-flanking region of the human DAO gene (zinc finger C2HC domain-containing protein 1A; histidine-tRNA ligase, cytoplasmic; molybdenum cofactor biosynthesis protein; 60S ribosomal protein L37; calponin-1; calmodulin binding protein and heterogeneous nuclear ribonucleoprotein A2/B1). These preliminary results will contribute to the advance in the understanding of the potential factors associated with the regulatory mechanism of DAO expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Micropatterning of bacteria on two-dimensional lattice protein surface observed by atomic force microscopy

    International Nuclear Information System (INIS)

    Oh, Y.J.; Jo, W.; Lim, J.; Park, S.; Kim, Y.S.; Kim, Y.

    2008-01-01

    In this study, we characterized the two-dimensional lattice of bovine serum albumin (BSA) as a chemical and physical barrier against bacterial adhesion, using fluorescence microscopy and atomic force microscopy (AFM). The lattice of BSA on glass surface was fabricated by micro-contact printing (μCP), which is a useful way to pattern a wide range of molecules into microscale features on different types of substrates. The contact-mode AFM measurements showed that the average height of the printed BSA monolayer was 5-6 nm. Escherichia coli adhered rapidly on bare glass slide, while the bacterial adhesion was minimized on the lattices in the range of 1-3 μm 2 . Especially, the bacterial adhesion was completely inhibited on a 1 μm 2 lattice. The results suggest that the anti-adhesion effects are due by the steric repulsion forces exerted by BSA

  14. Strain-engineered growth of two-dimensional materials.

    Science.gov (United States)

    Ahn, Geun Ho; Amani, Matin; Rasool, Haider; Lien, Der-Hsien; Mastandrea, James P; Ager Iii, Joel W; Dubey, Madan; Chrzan, Daryl C; Minor, Andrew M; Javey, Ali

    2017-09-20

    The application of strain to semiconductors allows for controlled modification of their band structure. This principle is employed for the manufacturing of devices ranging from high-performance transistors to solid-state lasers. Traditionally, strain is typically achieved via growth on lattice-mismatched substrates. For two-dimensional (2D) semiconductors, this is not feasible as they typically do not interact epitaxially with the substrate. Here, we demonstrate controlled strain engineering of 2D semiconductors during synthesis by utilizing the thermal coefficient of expansion mismatch between the substrate and semiconductor. Using WSe 2 as a model system, we demonstrate stable built-in strains ranging from 1% tensile to 0.2% compressive on substrates with different thermal coefficient of expansion. Consequently, we observe a dramatic modulation of the band structure, manifested by a strain-driven indirect-to-direct bandgap transition and brightening of the dark exciton in bilayer and monolayer WSe 2 , respectively. The growth method developed here should enable flexibility in design of more sophisticated devices based on 2D materials.Strain engineering is an essential tool for modifying local electronic properties in silicon-based electronics. Here, Ahn et al. demonstrate control of biaxial strain in two-dimensional materials based on the growth substrate, enabling more complex low-dimensional electronics.

  15. Separation of very hydrophobic analytes by micellar electrokinetic chromatography IV. Modeling of the effective electrophoretic mobility from carbon number equivalents and octanol-water partition coefficients.

    Science.gov (United States)

    Huhn, Carolin; Pyell, Ute

    2008-07-11

    It is investigated whether those relationships derived within an optimization scheme developed previously to optimize separations in micellar electrokinetic chromatography can be used to model effective electrophoretic mobilities of analytes strongly differing in their properties (polarity and type of interaction with the pseudostationary phase). The modeling is based on two parameter sets: (i) carbon number equivalents or octanol-water partition coefficients as analyte descriptors and (ii) four coefficients describing properties of the separation electrolyte (based on retention data for a homologous series of alkyl phenyl ketones used as reference analytes). The applicability of the proposed model is validated comparing experimental and calculated effective electrophoretic mobilities. The results demonstrate that the model can effectively be used to predict effective electrophoretic mobilities of neutral analytes from the determined carbon number equivalents or from octanol-water partition coefficients provided that the solvation parameters of the analytes of interest are similar to those of the reference analytes.

  16. Two-dimensional heat flow apparatus

    Science.gov (United States)

    McDougall, Patrick; Ayars, Eric

    2014-06-01

    We have created an apparatus to quantitatively measure two-dimensional heat flow in a metal plate using a grid of temperature sensors read by a microcontroller. Real-time temperature data are collected from the microcontroller by a computer for comparison with a computational model of the heat equation. The microcontroller-based sensor array allows previously unavailable levels of precision at very low cost, and the combination of measurement and modeling makes for an excellent apparatus for the advanced undergraduate laboratory course.

  17. Two-Dimensional Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Bo Jia

    2015-01-01

    (BP networks. However, like many other methods, ELM is originally proposed to handle vector pattern while nonvector patterns in real applications need to be explored, such as image data. We propose the two-dimensional extreme learning machine (2DELM based on the very natural idea to deal with matrix data directly. Unlike original ELM which handles vectors, 2DELM take the matrices as input features without vectorization. Empirical studies on several real image datasets show the efficiency and effectiveness of the algorithm.

  18. Two-dimensional Semiconductor-Superconductor Hybrids

    DEFF Research Database (Denmark)

    Suominen, Henri Juhani

    This thesis investigates hybrid two-dimensional semiconductor-superconductor (Sm-S) devices and presents a new material platform exhibiting intimate Sm-S coupling straight out of the box. Starting with the conventional approach, we investigate coupling superconductors to buried quantum well....... To overcome these issues we integrate the superconductor directly into the semiconducting material growth stack, depositing it in-situ in a molecular beam epitaxy system under high vacuum. We present a number of experiments on these hybrid heterostructures, demonstrating near unity interface transparency...

  19. Two-Dimensional Tellurene as Excellent Thermoelectric Material

    KAUST Repository

    Sharma, Sitansh; Singh, Nirpendra; Schwingenschlö gl, Udo

    2018-01-01

    We study the thermoelectric properties of two-dimensional tellurene by first-principles calculations and semiclassical Boltzmann transport theory. The HSE06 hybrid functional results in a moderate direct band gap of 1.48 eV at the Γ point. A high

  20. RPE cell surface proteins in normal and dystrophic rats

    International Nuclear Information System (INIS)

    Clark, V.M.; Hall, M.O.

    1986-01-01

    Membrane-bound proteins in plasma membrane enriched fractions from cultured rat RPE were analyzed by two-dimensional gel electrophoresis. Membrane proteins were characterized on three increasingly specific levels. Total protein was visualized by silver staining. A maximum of 102 separate proteins were counted in silver-stained gels. Glycoproteins were labeled with 3H-glucosamine or 3H-fucose and detected by autoradiography. Thirty-eight fucose-labeled and 61-71 glucosamine-labeled proteins were identified. All of the fucose-labeled proteins were labeled with glucosamine-derived radioactivity. Proteins exposed at the cell surface were labeled by lactoperoxidase-catalyzed radioiodination prior to preparation of membranes for two-dimensional analysis. Forty separate 125I-labeled surface proteins were resolved by two-dimensional electrophoresis/autoradiography. Comparison with the glycoprotein map showed that a number of these surface labeled proteins were glycoproteins. Two-dimensional maps of total protein, fucose-labeled, and glucosamine-labeled glycoproteins, and 125I-labeled surface proteins of membranes from dystrophic (RCS rdy-p+) and normal (Long Evans or RCS rdy+p+) RPE were compared. No differences in the total protein or surface-labeled proteins were observed. However, the results suggest that a 183K glycoprotein is more heavily glycosylated with glucosamine and fucose in normal RPE membranes as compared to membranes from dystrophic RPE

  1. Electrophoretic deposits of boron on duralumin plates used for measuring neutron flux

    International Nuclear Information System (INIS)

    Lang, F.M.; Magnier, P.; Finck, C.

    1956-01-01

    Preparation of boron thin film deposits of around 1 mg per cm 2 on duralumin plates with a diameter of 8 cm. The boron coated plates for ionization chambers were originally prepared at the CEA by pulverization of boron carbides on sodium silicates. This method is not controlling precisely enough the quantity of boron deposit. Thus, an electrophoretic method is considered for a better control of the quantity of boron deposit in the scope of using in the future boron 10 which is costly and rare. The method described by O. Flint is not satisfying enough and a similar electrophoretic process has been developed. Full description of the method is given as well as explanation of the use of dried methanol as solvent, tannin as electrolyte and magnesium chloride to avoid alumina formation. (M.P.)

  2. Laser bistatic two-dimensional scattering imaging simulation of lambert cone

    Science.gov (United States)

    Gong, Yanjun; Zhu, Chongyue; Wang, Mingjun; Gong, Lei

    2015-11-01

    This paper deals with the laser bistatic two-dimensional scattering imaging simulation of lambert cone. Two-dimensional imaging is called as planar imaging. It can reflect the shape of the target and material properties. Two-dimensional imaging has important significance for target recognition. The expression of bistatic laser scattering intensity of lambert cone is obtained based on laser radar eauqtion. The scattering intensity of a micro-element on the target could be obtained. The intensity is related to local angle of incidence, local angle of scattering and the infinitesimal area on the cone. According to the incident direction of laser, scattering direction and normal of infinitesimal area, the local incidence angle and scattering angle can be calculated. Through surface integration and the introduction of the rectangular function, we can get the intensity of imaging unit on the imaging surface, and then get Lambert cone bistatic laser two-dimensional scattering imaging simulation model. We analyze the effect of distinguishability, incident direction, observed direction and target size on the imaging. From the results, we can see that the scattering imaging simulation results of the lambert cone bistatic laser is correct.

  3. Bayesian approach for peak detection in two-dimensional chromatography.

    Science.gov (United States)

    Vivó-Truyols, Gabriel

    2012-03-20

    A new method for peak detection in two-dimensional chromatography is presented. In a first step, the method starts with a conventional one-dimensional peak detection algorithm to detect modulated peaks. In a second step, a sophisticated algorithm is constructed to decide which of the individual one-dimensional peaks have been originated from the same compound and should then be arranged in a two-dimensional peak. The merging algorithm is based on Bayesian inference. The user sets prior information about certain parameters (e.g., second-dimension retention time variability, first-dimension band broadening, chromatographic noise). On the basis of these priors, the algorithm calculates the probability of myriads of peak arrangements (i.e., ways of merging one-dimensional peaks), finding which of them holds the highest value. Uncertainty in each parameter can be accounted by adapting conveniently its probability distribution function, which in turn may change the final decision of the most probable peak arrangement. It has been demonstrated that the Bayesian approach presented in this paper follows the chromatographers' intuition. The algorithm has been applied and tested with LC × LC and GC × GC data and takes around 1 min to process chromatograms with several thousands of peaks.

  4. Electrophoretic deposition of PEEK-TiO 2 composite coatings on stainless steel

    KAUST Repository

    Seuß , Sigrid; Subhani, Tayyab; Yi Kang, Min; Okudaira, Kenji; Ventura, Isaac Aguilar; Boccaccini, Aldo R.

    2012-01-01

    Electrophoretic deposition (EPD) has been successfully used to deposit composite coatings composed of polyetheretherketone (PEEK) and titanium dioxide (TiO 2) nanoparticles on 316L stainless steel substrates. The suspensions of TiO2 nanoparticles

  5. Linkage analysis by two-dimensional DNA typing

    NARCIS (Netherlands)

    te Meerman, G J; Mullaart, E; Meulen ,van der Martin; den Daas, J H; Morolli, B; Uitterlinden, A G; Vijg, J

    1993-01-01

    In two-dimensional (2-D) DNA typing, genomic DNA fragments are separated, first according to size by electrophoresis in a neutral polyacrylamide gel and second according to sequence by denaturing gradient gel electrophoresis, followed by hybridization analysis using micro- and minisatellite core

  6. Device for measuring the two-dimensional distribution of a radioactive substance on a surface

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    A device is described by which, using a one-dimensional measuring proportional counter tube depending on position, one can measure the two-dimensionally distributed radioactivity of a surface and can plot this to scale two-dimensionally, after computer processing, or can show it two-dimensionally on a monitor. (orig.) [de

  7. Two-dimensional PCA-based human gait identification

    Science.gov (United States)

    Chen, Jinyan; Wu, Rongteng

    2012-11-01

    It is very necessary to recognize person through visual surveillance automatically for public security reason. Human gait based identification focus on recognizing human by his walking video automatically using computer vision and image processing approaches. As a potential biometric measure, human gait identification has attracted more and more researchers. Current human gait identification methods can be divided into two categories: model-based methods and motion-based methods. In this paper a two-Dimensional Principal Component Analysis and temporal-space analysis based human gait identification method is proposed. Using background estimation and image subtraction we can get a binary images sequence from the surveillance video. By comparing the difference of two adjacent images in the gait images sequence, we can get a difference binary images sequence. Every binary difference image indicates the body moving mode during a person walking. We use the following steps to extract the temporal-space features from the difference binary images sequence: Projecting one difference image to Y axis or X axis we can get two vectors. Project every difference image in the difference binary images sequence to Y axis or X axis difference binary images sequence we can get two matrixes. These two matrixes indicate the styles of one walking. Then Two-Dimensional Principal Component Analysis(2DPCA) is used to transform these two matrixes to two vectors while at the same time keep the maximum separability. Finally the similarity of two human gait images is calculated by the Euclidean distance of the two vectors. The performance of our methods is illustrated using the CASIA Gait Database.

  8. Preparation of guinea pig macrophage for electrophoretic experiments in space

    Science.gov (United States)

    1979-01-01

    Methods of storage and cultivation of macrophage cells in preparation for space experiments were investigated. Results show that freezing and thawing immediately after extraction did not cause any change in viability or electrophoretic mobility of the cells. A prolonged storage at -80 C did cause cell damage as indicated by a 95% reduction in variable cells. Cell damage was decreased when Glycerol or Dimethyl Sulfoxide (DMSO) was added as a cryogenic protective agent. A 100% viability was observed in cultivation experiments after two weeks due to the additional serum. Results from gamma-glutamyl transpeptidase study showed a zero activity rate. It is suggested that a flat stationary field be used for the collection and use of macrophage. It was found that a 24-hour delay in obtaining macrophage cells helps to maintain a pure culture.

  9. A two-dimensional lattice equation as an extension of the Heideman-Hogan recurrence

    Science.gov (United States)

    Kamiya, Ryo; Kanki, Masataka; Mase, Takafumi; Tokihiro, Tetsuji

    2018-03-01

    We consider a two dimensional extension of the so-called linearizable mappings. In particular, we start from the Heideman-Hogan recurrence, which is known as one of the linearizable Somos-like recurrences, and introduce one of its two dimensional extensions. The two dimensional lattice equation we present is linearizable in both directions, and has the Laurent and the coprimeness properties. Moreover, its reduction produces a generalized family of the Heideman-Hogan recurrence. Higher order examples of two dimensional linearizable lattice equations related to the Dana Scott recurrence are also discussed.

  10. Two-dimensional QCD as a model for strong interaction

    International Nuclear Information System (INIS)

    Ellis, J.

    1977-01-01

    After an introduction to the formalism of two-dimensional QCD, its applications to various strong interaction processes are reviewed. Among the topics discussed are spectroscopy, deep inelastic cross-sections, ''hard'' processes involving hadrons, ''Regge'' behaviour, the existence of the Pomeron, and inclusive hadron cross-sections. Attempts are made to abstracts features useful for four-dimensional QCD phenomenology. (author)

  11. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuanhu [Univ. of California, Berkeley, CA (United States)

    1997-09-01

    This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.

  12. Two dimensional infinite conformal symmetry

    International Nuclear Information System (INIS)

    Mohanta, N.N.; Tripathy, K.C.

    1993-01-01

    The invariant discontinuous (discrete) conformal transformation groups, namely the Kleinian and Fuchsian groups Gamma (with an arbitrary signature) of H (the Poincare upper half-plane l) and the unit disc Delta are explicitly constructed from the fundamental domain D. The Riemann surface with signatures of Gamma and conformally invariant automorphic forms (functions) with Peterson scalar product are discussed. The functor, where the category of complex Hilbert spaces spanned by the space of cusp forms constitutes the two dimensional conformal field theory. (Author) 7 refs

  13. Electrophoretic preparation and characterization of porous electrodes from diamond nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Riveros, Lyda La Torre; Soto, Keyla; Tryk, Donald A; Cabrera, Carlos R [Department of Chemistry and Center of Nanoscale Materials, University of Puerto Rico, Rio Piedras, PO Box 23346 San Juan, PR 00931-3346 (Puerto Rico)

    2007-04-15

    We carried out chemical purification of commercially available diamond nanoparticles by refluxing in aqueous HNO{sub 3} and characterized the samples by spectroscopic and surface techniques before and after purification. As a first step in the preparation of electrodes for electrochemistry, we have electrophoretically deposited thin, highly uniform films of controlled thickness (1-8 {mu}m) on silicon substrates using the purified diamond nanoparticles. These have been characterized by scanning electron microscopy (SEM). All films obtained were homogeneous in thickness and without macroscopic holes or cracks. Such structures could also be used in many other applications such as fuel cells or lithium batteries. We have performed cyclic voltammetry experiments with these electrodes. The voltammograms of diamond nanoparticles electrophoretically deposited on silicon indicate hydrogen evolution. This demonstrates that the material is useful as electrocatalitic support. This conclusion is supported by the cyclic voltammograms obtained using ferrycyanide (III) chloride and hexaamineruthenium (III) chloride complexes as redox probes. However, these redox probes showed very small peak currents. This behavior could be improved by doping the diamond nanoparticles with an impurity such as boron.

  14. Electrophoretic preparation and characterization of porous electrodes from diamond nanoparticles

    International Nuclear Information System (INIS)

    Riveros, Lyda La Torre; Soto, Keyla; Tryk, Donald A; Cabrera, Carlos R

    2007-01-01

    We carried out chemical purification of commercially available diamond nanoparticles by refluxing in aqueous HNO 3 and characterized the samples by spectroscopic and surface techniques before and after purification. As a first step in the preparation of electrodes for electrochemistry, we have electrophoretically deposited thin, highly uniform films of controlled thickness (1-8 μm) on silicon substrates using the purified diamond nanoparticles. These have been characterized by scanning electron microscopy (SEM). All films obtained were homogeneous in thickness and without macroscopic holes or cracks. Such structures could also be used in many other applications such as fuel cells or lithium batteries. We have performed cyclic voltammetry experiments with these electrodes. The voltammograms of diamond nanoparticles electrophoretically deposited on silicon indicate hydrogen evolution. This demonstrates that the material is useful as electrocatalitic support. This conclusion is supported by the cyclic voltammograms obtained using ferrycyanide (III) chloride and hexaamineruthenium (III) chloride complexes as redox probes. However, these redox probes showed very small peak currents. This behavior could be improved by doping the diamond nanoparticles with an impurity such as boron

  15. Stabilizing local boundary conditions for two-dimensional shallow water equations

    KAUST Repository

    Dia, Ben Mansour; Oppelstrup, Jesper

    2018-01-01

    In this article, we present a sub-critical two-dimensional shallow water flow regulation. From the energy estimate of a set of one-dimensional boundary stabilization problems, we obtain a set of polynomial equations with respect to the boundary

  16. Logarithmic Superdiffusion in Two Dimensional Driven Lattice Gases

    Science.gov (United States)

    Krug, J.; Neiss, R. A.; Schadschneider, A.; Schmidt, J.

    2018-03-01

    The spreading of density fluctuations in two-dimensional driven diffusive systems is marginally anomalous. Mode coupling theory predicts that the diffusivity in the direction of the drive diverges with time as (ln t)^{2/3} with a prefactor depending on the macroscopic current-density relation and the diffusion tensor of the fluctuating hydrodynamic field equation. Here we present the first numerical verification of this behavior for a particular version of the two-dimensional asymmetric exclusion process. Particles jump strictly asymmetrically along one of the lattice directions and symmetrically along the other, and an anisotropy parameter p governs the ratio between the two rates. Using a novel massively parallel coupling algorithm that strongly reduces the fluctuations in the numerical estimate of the two-point correlation function, we are able to accurately determine the exponent of the logarithmic correction. In addition, the variation of the prefactor with p provides a stringent test of mode coupling theory.

  17. Waterlike anomalies in a two-dimensional core-softened potential

    Science.gov (United States)

    Bordin, José Rafael; Barbosa, Marcia C.

    2018-02-01

    We investigate the structural, thermodynamic, and dynamic behavior of a two-dimensional (2D) core-corona system using Langevin dynamics simulations. The particles are modeled by employing a core-softened potential which exhibits waterlike anomalies in three dimensions. In previous studies in a quasi-2D system a new region in the pressure versus temperature phase diagram of structural anomalies was observed. Here we show that for the two-dimensional case two regions in the pressure versus temperature phase diagram with structural, density, and diffusion anomalies are observed. Our findings indicate that, while the anomalous region at lower densities is due the competition between the two length scales in the potential at higher densities, the anomalous region is related to the reentrance of the melting line.

  18. On the confinement of a Dirac particle to a two-dimensional ring

    International Nuclear Information System (INIS)

    Bakke, K.; Furtado, C.

    2012-01-01

    In this contribution, we propose a new model for studying the confinement of a spin-half particle to a two-dimensional quantum ring for systems described by the Dirac equation by introducing a new coupling into the Dirac equation. We show that the introduction of this new coupling into the Dirac equation yields a generalization of the two-dimensional quantum ring model proposed by Tan and Inkson [W.-C. Tan, J.C. Inkson, Semicond. Sci. Technol. 11 (1996) 1635] for relativistic spin-half quantum particles. -- Highlights: ► Two-dimensional ring model for condensed matter systems described by the Dirac equation. ► Exact solutions of the Dirac equation. ► Persistent currents for Dirac-like systems confined to a two-dimensional quantum ring.

  19. Mode selection in two-dimensional Bragg resonators based on planar dielectric waveguides

    International Nuclear Information System (INIS)

    Baryshev, V R; Ginzburg, N S; Zaslavskii, V Yu; Malkin, A M; Sergeev, A S; Thumm, M

    2009-01-01

    Two-dimensional Bragg resonators based on planar dielectric waveguides are analysed. It is shown that the doubly periodic corrugation deposited on the dielectric surface in the form of two gratings with translational vectors directed perpendicular to each other ensures effective selection of modes along two coordinates at large Fresnel parameters. This result is obtained both by the method of coupled waves (geometrical optics approximation) and by the direct numerical simulations. Two-dimensional Bragg resonators make it possible to fabricate two-dimensional distributed feedback lasers and to provide generation of spatially coherent radiation in large-volume active media. (waveguides)

  20. Theories to support method development in comprehensive two-dimensional liquid chromatography - A review

    NARCIS (Netherlands)

    Bedani, F.; Schoenmakers, P.J.; Janssen, H.-G.

    2012-01-01

    On-line comprehensive two-dimensional liquid chromatography techniques promise to resolve samples that current one-dimensional liquid chromatography methods cannot adequately deal with. To make full use of the potential of two-dimensional liquid chromatography, optimization is required. Optimization