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Sample records for delivery affinity separations

  1. Separation of Proteins by Electrophoretic Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    邺韶骅; 刘铮; 丁富新; 袁乃驹

    1999-01-01

    A new kind of electrophoretic affinity chromatography (EAC) for bioseparation was proposed,Separation by EAC was conducted in a multicompartment electrolyzer in which the affinity gel media were packed in one of the central compartments.The presence of an electric field accelerated the migration of proteins inside the gel matrix during adsorption and descrption processes,This led to the increase of the overall speed of separation,The present study was focused on the effect of the strength of the electric field on adsorption and desorption processes.

  2. Separation of enantiomers by affinity electrokinetic chromatography using avidin.

    Science.gov (United States)

    Tanaka, Y; Matsubara, N; Terabe, S

    1994-06-01

    Avidin, a basic protein isolated from egg white, was employed as a chiral selector in affinity electrokinetic chromatography (EKC) for the separation of acidic enantiomers. Optical isomers of vanilmandelic acid, warfarin, ibuprofen, ketoprofen, flurbiprofen, and folinic acid were successfully resolved within 20 min with 25 microM avidin in a linear polyacrylamide-coated capillary under weakly acidic conditions. The effects of pH, the concentration of avidin, addition of an organic solvent such as ethanol and 2-propanol, and temperature on enantioselectivity were investigated. The choice of pH and the organic solvent additive was critical to improve the separation. Some general considerations about affinity EKC are also described, based on a simple one-site interaction model.

  3. Study on Removal of Bilirubin with Magnetic Affinity Separation Technique

    Institute of Scientific and Technical Information of China (English)

    张凤宝; 王淑兰; 徐辉; 张国亮

    2003-01-01

    An affinity adsorbent, Cibacron Blue 3GA immobilized magnetic polyvinyl alcohol (PVA) microspheres was used for bilirubin removal taking the advantage of easy separation of magnetic sorbent from the biosystem.Fe3 O4 superparamagnetic particles was synthesized with hydrothermal reaction of ferrous chloride (FeC12) and ferric chloride (FeCl3). Such magnetic particles are then encapsulated in biocompatible PVA to form magnetic polymer microspheres sized from 2 to 15 nm with hydroxyl groups on its surface. Cibacron Blue 3GA, a dye-ligand, was covalently coupled with the polyvinyl alcohol through the nucleophilic reaction between the chloride of its triazine ring and the hydroxyl groups of PVA molecules under alkaline condition. The affinity adsorbent carried 21.1μmol Cibacron Blue 3GA per gram magnetic polymer microspheres was used to remove unconjugated and conjugated bilirubin from the solution which was composed of bilirubin or bilirubin and protein. After the adsorption, the adsorbent loaded with bilirubin was removed easily in the magnetic field.

  4. Beam delivery for stable isotope separation

    Science.gov (United States)

    Forbes, Andrew; Strydom, Hendrick J.; Botha, Lourens R.; Ronander, Einar

    2002-10-01

    In the multi-photon dissociation process of Carbon isotope enrichment, IR photons are used to selectively excite a molecule with the given isotopic base element. This enrichment process is very sensitive to the beam's intensity and wavelength. Because the intensity is determined by the propagation of the field, the enrichment factors are also very dependent on the field propagation. In this paper, the influence of the wavelength and intensity of the beam, on the isotope selective dissociation of a CFC compound is investigated both experimentally and theoretically. Consideration is also given to some of the factors that influence the delivery of various beams to the reactor chamber, and their subsequent propagation through the reactor. The results show that suitable beam forming can lead to an improved isotope separation process.

  5. Bioskin as an affinity matrix for the separation of glycoproteins.

    Science.gov (United States)

    Vicente, C; Sebastián, B; Fontaniella, B; Márquez, A; Xavier Filho, L; Legaz, M E

    2001-05-11

    Bioskin is a natural product produced by a mixed culture of Acetobacter xylinum, Saccharomyces cerevisiae and S. pombe cultured on media containing sucrose. It is of fibrillar nature able to retain some proteins, such as cytochrome c, by adsorption, and mainly composed of glucosamine and N-acetyl-D-glucosamine. This makes it possible that, at an adequate pH value, proteins charged as polyanionic molecules, such as catalase, can be retained by ionic adsorption using the positively charged amino groups of the matrix. In addition, bioskin can also be used as an affinity matrix to retain glycoproteins able to perform specific affinity reactions with the amino sugars of the matrix, such as invertase, fetuin or ovalbumin. Its possible use as a chromatographic support is discussed.

  6. [Separation and purification of cellulase using affinity membrane].

    Science.gov (United States)

    Shi, Xiang-zhu; Guo, Chun-teng; Zhou, Jian-wu; Wang, Zhong-lai; Rao, Ping-fan

    2002-07-01

    The importance of cellulase as a means for the efficient utilization of abundant cellulose resources in the world has been well recognized. Many researchers devote themselves to studying the mechanism of the action of cellulase to cellulose so that such expensive enzyme can be used much more widely. The first step is to obtain cellulase of high purity. So purification of cellulase is the key point in this field. However, the major problem in isolation is that cellulase is a complicated enzyme system and needs too many steps for separation, and that every cellulase needs special purification processing which cannot be used for the others. A novel method for the separation of the cellulase from crude extraction of Aspergillus niger with normal qualitative filter paper processed by 5 mol/L sodium hydroxide without precipitation and desalting steps was developed. Further purification of the cellulase was achieved by using an anion-exchange column of POROS 20HQ. The cellulase purified was identified as a new endoglucanase that had relatively high endurance to pH and temperature. Its relative molecular mass was estimated to be 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This enzyme exhibited very high activity towards carboxymethyl cellulose (CMC) with specific activity of 350 U.mg-1 and the recovery of activity of 9.7%. Its optimum pH and temperature were 4.0 and 70 degrees C, respectively. This is a simple, rapid and efficient method for purifying cellulase with high activity.

  7. Separation and Purification of Thrombin-like Enzymes by Affinity Adsorbents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An affinity adsorbent, benzamidineSepharose 4B, was used to separate and purify thrombinlike enzymes. The paminobenzamidine as a specific ligand was coupled to the matrix-Sepharose 4B. The recombinant thrombinlike enzyme-defibrase was used as a model in order to evaluate the efficiency of this biospecific affinity adsorbent. The homogeneity of the enzyme preparation was comfirmed as one band on sodium dodecyl sulfatepolyacrylamide gel electrophoresis.

  8. Introduction of structural affinity handles as a tool in selective nucleic acid separations

    Science.gov (United States)

    Willson, III, Richard Coale (Inventor); Cano, Luis Antonio (Inventor)

    2011-01-01

    The method is used for separating nucleic acids and other similar constructs. It involves selective introduction, enhancement, or stabilization of affinity handles such as single-strandedness in the undesired (or desired) nucleic acids as compared to the usual structure (e.g., double-strandedness) of the desired (or undesired) nucleic acids. The undesired (or desired) nucleic acids are separated from the desired (or undesired) nucleic acids due to capture by methods including but not limited to immobilized metal affinity chromatography, immobilized single-stranded DNA binding (SSB) protein, and immobilized oligonucleotides. The invention is useful to: remove contaminating genomic DNA from plasmid DNA; remove genomic DNA from plasmids, BACs, and similar constructs; selectively separate oligonucleotides and similar DNA fragments from their partner strands; purification of aptamers, (deoxy)-ribozymes and other highly structured nucleic acids; Separation of restriction fragments without using agarose gels; manufacture recombinant Taq polymerase or similar products that are sensitive to host genomic DNA contamination; and other applications.

  9. Preparation of ethylene vinylalcohol copolymer membranes suitable for ligand coupling in affinity separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Sager, W.F.C.; Mulder, M.H.V.; Wessling, Matthias

    2002-01-01

    Hydrophilic microfiltration membranes with functional groups that can be used as coupling sites for ligands are of central interest in affinity separation, especially in view of biomedical applications. In this study, we employed ethylene vinyl alcohol copolymer (EVAL) to prepare macrovoid-free open

  10. Functionalised ethylene vinyl alcohol copolymer (EVAL) membranes for affinity protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Sager, W.F.C.; Wessling, M.

    2003-01-01

    Hydrophilic microfiltration membranes with functional groups that can be used as coupling sites for ligands are of central interest in affinity separation, especially in view of biomedical applications. In this study we investigate covalent coupling of bovine serum albumin (BSA) as model ligand onto

  11. Designer protein delivery: From natural to engineered affinity-controlled release systems.

    Science.gov (United States)

    Pakulska, Malgosia M; Miersch, Shane; Shoichet, Molly S

    2016-03-18

    Exploiting binding affinities between molecules is an established practice in many fields, including biochemical separations, diagnostics, and drug development; however, using these affinities to control biomolecule release is a more recent strategy. Affinity-controlled release takes advantage of the reversible nature of noncovalent interactions between a therapeutic protein and a binding partner to slow the diffusive release of the protein from a vehicle. This process, in contrast to degradation-controlled sustained-release formulations such as poly(lactic-co-glycolic acid) microspheres, is controlled through the strength of the binding interaction, the binding kinetics, and the concentration of binding partners. In the context of affinity-controlled release--and specifically the discovery or design of binding partners--we review advances in in vitro selection and directed evolution of proteins, peptides, and oligonucleotides (aptamers), aided by computational design.

  12. Fluorescent Boronic Acid Polymer Grafted on Silica Particles for Affinity Separation of Saccharides

    Science.gov (United States)

    2014-01-01

    Boronic acid affinity gels are important for effective separation of biological active cis-diols, and are finding applications both in biotech industry and in biomedical research areas. To increase the efficacy of boronate affinity separation, it is interesting to introduce repeating boronic acid units in flexible polymer chains attached on solid materials. In this work, we synthesize polymer brushes containing boronic acid repeating units on silica gels using surface-initiated atom transfer radical polymerization (ATRP). A fluorescent boronic acid monomer is first prepared from an azide-tagged fluorogenic boronic acid and an alkyne-containing acrylate by Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction (the CuAAC click chemistry). The boronic acid monomer is then grafted to the surface of silica gel modified with an ATRP initiator. The obtained composite material contains boronic acid polymer brushes on surface and shows favorable saccharide binding capability under physiological pH conditions, and displays interesting fluorescence intensity change upon binding fructose and glucose. In addition to saccharide binding, the flexible polymer brushes on silica also enable fast separation of a model glycoprotein based on selective boronate affinity interaction. The synthetic approach and the composite functional material developed in this work should open new opportunities for high efficiency detection, separation, and analysis of not only simple saccharides, but also glycopeptides and large glycoproteins. PMID:24444898

  13. Multiparameter cell affinity chromatography: separation and analysis in a single microfluidic channel.

    Science.gov (United States)

    Li, Peng; Gao, Yan; Pappas, Dimitri

    2012-10-02

    The ability to sort and capture more than one cell type from a complex sample will enable a wide variety of studies of cell proliferation and death and the analysis of disease states. In this work, we integrated a pneumatic actuated control layer to an affinity separation layer to create different antibody-coating regions on the same fluidic channel. The comparison of different antibody capture capabilities to the same cell line was demonstrated by flowing Ramos cells through anti-CD19- and anti-CD71-coated regions in the same channel. It was determined that the cell capture density on the anti-CD19 region was 2.44 ± 0.13 times higher than that on the anti-CD71-coated region. This approach can be used to test different affinity molecules for selectivity and capture efficiency using a single cell line in one separation. Selective capture of Ramos and HuT 78 cells from a mixture was also demonstrated using two antibody regions in the same channel. Greater than 90% purity was obtained on both capture areas in both continuous flow and stop flow separation modes. A four-region antibody-coated device was then fabricated to study the simultaneous, serial capture of three different cell lines. In this case the device showed effective capture of cells in a single separation channel, opening up the possibility of multiple cell sorting. Multiparameter sequential blood sample analysis was also demonstrated with high capture specificity (>97% for both CD19+ and CD4+ leukocytes). The chip can also be used to selectively treat cells after affinity separation.

  14. Exploiting Diffusion Barrier and Chemical Affinity of Metal-Organic Frameworks for Efficient Hydrogen Isotope Separation.

    Science.gov (United States)

    Kim, Jin Yeong; Balderas-Xicohtencatl, Rafael; Zhang, Linda; Kang, Sung Gu; Hirscher, Michael; Oh, Hyunchul; Moon, Hoi Ri

    2017-09-23

    Deuterium plays a pivotal role in industrial and scientific research, and is irreplaceable for various applications such as isotope tracing, neutron moderation, and neutron scattering. In addition, deuterium is a key energy source for fusion reactions. Thus, the isolation of deuterium from physico-chemically almost identical isotopic mixture is a seminal challenge in modern separation technology. However, current commercial approaches suffer from extremely low separation efficiency (i.e. cryogenic distillation, selectivity of 1.5 at 24 K), requiring a cost-effective and large-scale separation technique. Herein, we report a highly effective hydrogen isotope separation system based on metal-organic frameworks (MOFs) having the highest reported separation factor as high as ~26 at 77 K by maximizing synergistic effects of the chemical affinity quantum sieving (CAQS) and kinetic quantum sieving (KQS). For this purpose, MOF-74 system having high hydrogen adsorption enthalpies due to strong open metal sites is chosen for CAQS functionality and imidazole molecules (IM) are employed to the system for enhancing the KQS effect. To the best of our knowledge, this work is not only the first attempt to implement two quantum sieving effects, KQS and CAQS, in one system but also provides experimental validation of the utility of this system for practical industrial usage by isolating high-purity D2 through direct selective separation studies using 1:1 D2/H2 mixtures.

  15. Chromatography on DEAE ion-exchange and Protein G affinity columns in tandem for the separation and purification of proteins.

    Science.gov (United States)

    Qi, Y; Yan, Z; Huang, J

    2001-10-30

    A high-performance liquid-chromatographic method based on coupled DEAE anion-exchange and Protein G affinity columns has been developed for the simultaneous separation and purification of immunoglobulin G and albumin from mouse serum. The diluted mouse serum was injected directly into this system, and the proteins were eluted separately from the DEAE and Protein G columns, coupled in series, by the column-switching technique. The advantages of this method are that IgG and albumin can be separated and purified simultaneously, the expensive affinity column is protected from contamination by the impurities in the mouse serum, and it is fast, selective, robust, and reproducible.

  16. Self-assembled nanoplatform for targeted delivery of chemotherapy agents via affinity-regulated molecular interactions.

    Science.gov (United States)

    Park, Spencer; Kang, Sungkwon; Veach, Alexander J; Vedvyas, Yogindra; Zarnegar, Rasa; Kim, Ju-Young; Jin, Moonsoo M

    2010-10-01

    Site-specific delivery of drugs while minimizing unwanted distribution has been one of the pursued goals in cancer therapy. In this endeavor, we have developed targeted polymeric nanoparticles called amphiphilic urethane acrylate nonionomer (UAN) for encapsulation of diverse water-insoluble drugs and diagnostic agents, as well as for simple and reproducible surface conjugation of targeting ligands. Using monoclonal antibodies or lymphocyte function-associated antigen-1 (LFA-1) I domain engineered for varying affinities to intercellular adhesion molecule (ICAM)-1, we were able to deliver UAN nanoparticles to human cancer cells with the efficiency dependent on the strength of the molecular interactions and the degree of ICAM-1 expression on cell surface. Compared to non-specific uptake of free drugs, targeted delivery of UAN nanoparticles carrying equal amount of drugs produced more potent cytotoxicity. Notably, without the targeting ligands attached, UAN nanoparticles were largely precluded from non-specific uptake by the cells, resulting in much lower toxicity. The versatility of our UAN nanoparticles in both payload encapsulation and presentation of targeting ligands may facilitate developing a robust platform for evaluating various combinations of cancer drugs and molecular interactions toward developing effective cancer therapy formulations.

  17. Affinity adsorption and separation behaviors of avidin on biofunctional magnetic nanoparticles binding to iminobiotin.

    Science.gov (United States)

    Sun, Shuguo; Ma, Meihu; Qiu, Ning; Huang, Xi; Cai, Zhaoxia; Huang, Qun; Hu, Xin

    2011-11-01

    Knowing the adsorption behavior of target proteins on biofunctional magnetic nanoparticles is of great importance for the separation and purification of proteins. Adsorption behaviors of avidin on biofunctional magnetic nanoparticles binding to iminobiotin were investigated under different conditions of temperature, pH, ionic strength, and feed avidin concentration. Biofunctionalization of the non-functional nanoparticles was performed, coupled with iminobiotin. Characterization of the particles was carried out using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The results showed the avidin adsorption behaviors were mainly dependent on affinity interaction between avidin and iminobiotin coupled with the nanoparticles, which exhibited temperature, pH, ionic strength, and feed avidin concentration sensitivity. Maximum avidin adsorption capacity was achieved as 225 mg avidin/g biofunctional nanoparticles. Results were well fitted to the Langmuir isotherm model with the feed avidin concentration of less than 45 μg/ml. Based on the experiments above, the biofunctional magnetic nanoparticles were used to separate avidin from treated egg-white solution containing large amounts of other proteins. The avidin was isolated in 92% yield with an optical purity of more than 98.5% according to the HPSEC data. The regeneration of these nanoparticles was also studied and almost 87.3% of avidin could still be recovered by these regenerated nanoparticles. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Purification of human immunoglobulin G autoantibodies to tumor necrosis factor using affinity chromatography and magnetic separation.

    Science.gov (United States)

    Sennikov, S V; Golikova, E A; Kireev, F D; Lopatnikova, J A

    2013-04-30

    Autoantibodies to cytokines are important biological effector molecules that can regulate cytokine activities. The aim of the study was to develop a protocol to purify autoantibodies to tumor necrosis factor from human serum, for use as a calibration material to determine the absolute content of autoantibodies to tumor necrosis factor by enzyme-linked immunosorbent assay. The proposed protocol includes a set of affinity chromatography methods, namely, Bio-Gel P6DG sorbent to remove albumin from serum, Protein G Sepharose 4 Fast Flow to obtain a total immunoglobulin G fraction of serum immunoglobulins, and Affi-Gel 15 to obtain specifically antibodies to tumor necrosis factor. The addition of a magnetic separation procedure to the protocol eliminated contaminant tumor necrosis factor from the fraction of autoantibodies to tumor necrosis factor. The protocol generated a pure fraction of autoantibodies to tumor necrosis factor, and enabled us to determine the absolute concentrations of different subclasses of immunoglobulin G autoantibodies to tumor necrosis factor in apparently healthy donors.

  19. Separation and analysis of cis-diol-containing compounds by boronate affinity-assisted micellar electrokinetic chromatography.

    Science.gov (United States)

    Wang, Heye; Lü, Chenchen; Li, Hengye; Chen, Yang; Zhou, Min; Ouyang, Jian; Liu, Zhen

    2013-10-01

    Cis-diol-containing compounds (CDCCs) are usually highly hydrophilic compounds and are therefore difficult to separate by conventional reversed-phase-based micellar electrokinetic chromatography (MEKC) due to poor selectivity. Here, we report a new method, called boronate affinity-assisted micellar electrokinetic chromatography (BAA-MEKC), to solve this issue. A boronic acid with a hydrophobic alkyl chain was added to the background electrolyte, which acted as a modifier to adjust the selectivity. CDCCs can covalently react with the boronic acid to form negatively charged surfactant-like complexes, which can partition into micelles formed with a cationic surfactant. Thus, CDCCs can be separated according to the differential partition constants of their boronic acid complexes between the micellar phase and the surrounding aqueous phase. To verify this method, eight nucleosides were employed as the test compounds and their separation confirmed that the combination of boronate affinity interaction with MEKC can effectively enhance the separation of CDCCs. The effects of experimental conditions on the separation were investigated. Finally, the BAA-MEKC method was applied to the separation and analysis of nucleosides extracted from human urine. BAA-MEKC exhibited better selectivity and improved separation as compared with conventional MEKC and CZE. Successful quantitative analysis of urinary nucleosides by BAA-MEKC was demonstrated.

  20. Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique

    Energy Technology Data Exchange (ETDEWEB)

    Steingroewer, Juliane [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)]. E-mail: juliane.steingroewer@tu-dresden.de; Bley, Thomas [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany); Bergemann, Christian [Chemicell GmbH, D-10823, Berlin (Germany); Boschke, Elke [Institute of Food Technology and Bioprocess Engineering, Technische Universitaet Dresden, D-01062 Dresden (Germany)

    2007-04-15

    Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

  1. Enhancing separation of histidine from amino acids via free-flow affinity electrophoresis with gravity-induced uniform hydrodynamic flow.

    Science.gov (United States)

    Pang, Bo; Shao, Jing; Zhang, Jie; Geng, Jia-Zhen; Fan, Liu-Yin; Cao, Cheng-Xi; Hou, Jing-Li

    2012-03-01

    In this paper, a novel mode of free-flow affinity electrophoresis (FFAE) was developed to indirectly enhance the separation of free-flow electrophoresis (FFE). In the mode of FFAE, a Ni(II) with high electric charge density and histidine (His) is chosen as a model ligand and target solute, respectively. Through the controlling of experimental conditions (10 mM pH 6.0 Na(2)HPO(4)-NaH(2)PO(4) with 2.0 mM NiCl(2)·6H(2)O background buffer), Ni(II) can combine with His and the combination leads to the high electric charge density of affinity complex of His-Ni(II) in contrast to the low density of free His molecule. But the ligand has weak interaction with uninterested amino acids. Thus, the mobility of His existing as His-Ni(II) is greatly increased from 14.5×10(-8) m(2) V(-1) s(-1) to 30.2 × 10(-8) m(2) V(-1) s(-1), while those mobilities of uninterested amino acids are almost constant. By virtue of the mode, we developed the FFAE procedure and conducted the relevant experiments. The experiments demonstrated the following merits of the FFAE technique: (i) clear enhancement of separation between the target solute of His and uninterested amino acids; (ii) simplicity, and (iii) low cost. Furthermore, the technique was used for the continuous separation of His from its complex sample, and the purity of His was near to 100%. All of the results demonstrate the feasibility of affinity separation in FFE. The developed FFAE may be used in the separation and pretreatment of some biological molecules (e.g. peptides).

  2. Improved Interfacial Affinity and CO2 Separation Performance of Asymmetric Mixed Matrix Membranes by Incorporating Postmodified MIL-53(Al).

    Science.gov (United States)

    Zhu, Haitao; Wang, Lina; Jie, Xingming; Liu, Dandan; Cao, Yiming

    2016-08-31

    Asymmetric mixed matrix membranes(MMMs) with MOFs hold great application potential for energy-efficient gas separations. However, the particle aggregation and nonselective interfacial microvoids restrict the gas separation performance of asymmetric MMMs. Herein, nanoporous metal-organic framework (MOF) of MIL-53(Al) was modified with aminosilane after solvothermal synthesis. The postfunctionalization by grafting alkyl chains can form hydrogen bonds with polymer chains to enhance the affinity with polymer matrix and facilitate the preferential adsorption of CO2 by dipole-quadrupole interaction with the functional group. Then the postmodified MIL-53(Al) was incorporated as filler into poly(ether imide) Ultem1000 to fabricate high-quality asymmetric MMMs with well dispersed particles in polymer matrix and good adhesion at the MOFs-polymer interface. The Ultem/S-MIL-53(Al) asymmetric MMMs exhibited remarkable combinations of gas permeance and ideal selectivity for CO2/N2 separation at 10 wt % filler loading. The CO2 permeance achieved 24.1 GPU, an increase of 165% compared with pure Ultem membrane. Meanwhile, the ideal CO2/N2 selectivity also increased from 31.0 up to 41.1. The strategy of post covalent modification for MOFs provides an effective way to improve the interfacial affinity and gas separation performance.

  3. Selective Affinity Separation of Yeast Alcohol Dehydrogenase by Reverse Micelles with Unbound Triazine Dye

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The reversed micelles were formed with cationic cetyltrimethylammonium bromide (CTAB) as surfac tant and n-hexanol as cosolvent in the CTAB (50mmol.L-1)/hexanol (15% by volume)/hexane system. Cibacron Blue 3GA (CB) as an affinity ligand in the aqueous phase was directly introduced to the reversed micelles with electrostatic interaction between anionic CB and cationic surfactant. High molecular weight (Mr) protein, yeast alcohol dehydrogenase (YADH, Mr = 141000) from baker's yeast, has been purified using the affinity reversed micelles by the phase transfer method. Various parameters, such as CB concentration, pH and ionic strength, on YADH forward and backward transfer were studied. YADH can be transferred into and out from the reversed mi celles under mild conditions (only by regulation of solution pH and salt concentration) with the successful recovery of most YADH activity. Both forward and backward extractions occurred when the aqueous phase pH>pI with electrostatic attraction between YADH and CTAB. The recovery of YADH activity and purification factor have been improved with addition of a small amount of affinity CB. The recovery of YADH activity obtained was ~99% and the purification factor was about 4.0-fold after one cycle of full forward and backward extraction. The low ionic strength in the initial aqueous phase might be responsible for the YADH transfer into the reversed micellar phase.

  4. Selective Affinity Separation of Yeast Alcohol Dehydrogenase by Reverse Micelles with Unbound Triazine Dye*

    Institute of Scientific and Technical Information of China (English)

    张天喜; 刘会洲; 陈家镛

    2001-01-01

    The reversed micelles were formed with cationic cetyltrimethylammonium bromide (CTAB) as surfactant and n-hexanol as cosolvent in the CTAB (50 mmol·L- 1)/hexanol (15% by volume)/hexane system. Cibacron Blue 3GA (CB) as an affinity ligand in the aqueous phase was directly introduced to the reversed micelles with electrostatic interaction between anionic CB and cationic surfactant. High molecular weight (Mr) protein, yeast alcohol dehydrogenase (YADH, Mr = 141000) from baker's yeast, has been purified using the affinity reversed micelles by the phase transfer method. Various parameters, such as CB concentration, pH and ionic strength, on YADH forward and backward transfer were studied. YADH can be transferred into and out from the reversed micelles under mild conditions (only by regulation of solution pH and salt concentration) with the successful recoveryof most YADH activity. Both forward and backward extractions occurred when the aqueous phase pH>pI with electrostatic attraction between YADH and CTAB. The recovery of YADH activity and purification factor have been improved with addition of a small amount of affinity CB. The recovery of YADH activity obtained was 99% and the purification factor was about 4.0-fold after one cycle of full forward and backward extraction. The low ionic strength in the initial aqueous phase might be responsible for the YADH transfer into the reversed micellar phase.

  5. Use of Dye-Ligand Affinity Chromatography for Separation of Toxin Components of Bacillus Anthracis

    Science.gov (United States)

    1983-05-18

    7.5 ( Trizma base, BioRad Laboratories) at 4 0C for 18 h before use. Dye-ligand affinity chromatography columns, supplied as a dye matrix screening kit...temperature with 10 ml 8 M urea. The columns were then equilibrated with 10 ml starting buffer (20 mM Tris/HC1, pH 7.5) at 4 0°C. Two milliliters of crude...toxin containing approximately 40 jig protein per ml were passed into each column. The buffer flow was then halted for 30 min to allow binding of

  6. Phase-separated chitosan-fibrin microbeads for cell delivery.

    Science.gov (United States)

    Chen, Zhewei; Wang, Limin; Stegemann, Jan P

    2011-01-01

    Matrix-enhanced delivery of cells is a promising approach to improving current cell therapies. Our objective was to create cell-laden composite microbeads that combine the attractive features of the natural polymers chitosan and fibrin. Liquid polydimethylsiloxane was used to emulsify a chitosan-fibrinogen solution containing suspended human fibroblast cells, followed by initiation of thrombin-mediated polymerization of fibrin and thermal/pH-mediated gelation of chitosan. Chitosan/fibrin weight percent (wt%) ratios of 100/0, 75/25, 50/50 and 25/75 were investigated. Microbead diameters ranged from 275 ± 99 µm to 38 ± 10 µm using impeller speeds from 600 to 1400 rpm. Fibroblasts remained viable on day 1 post-fabrication in all matrices, but cell viability was markedly higher in high-fibrin microbeads by day 8 post-fabrication. Cell spreading and interaction with the extracellular matrix was also markedly increased in high-fibrin matrices. Such composite microbeads containing viable entrapped cells have potential for minimally invasive delivery of cells for a variety of tissue repair applications.

  7. Affinity separation of human plasma gelsolin on Affi-Gel Blue.

    Science.gov (United States)

    Yamamoto, H; Terabayashi, M; Egawa, T; Hayashi, E; Nakamura, H; Kishimoto, S

    1989-05-01

    Human plasma gelsolin was specifically eluted with 1 mM adenosine 5'-triphosphate from an Affi-Gel Blue column. Since the ionic strength of sodium chloride required to elute the protein from the dye column was much higher than that of 1 mM adenosine 5'-triphosphate, the binding of plasma gelsolin with the dye-ligand appeared to be biospecific. Taking advantage of this affinity interaction, we have developed a revised purification method of human plasma gelsolin. The purification included ammonium sulfate precipitation, diethylaminoethyl-Sepharose chromatography, Affi-Gel Blue chromatography, and Phenyl-Sepharose chromatography. The method allowed a reproducible purification of the protein to apparent homogeneity, producing a 331-fold purification with a yield of 6%.

  8. Contamination of ribosome inactivating proteins with ribonucleases, separated by affinity chromatography on red sepharose.

    Science.gov (United States)

    Wang, H X; Ng, T B; Cheng, C H K; Fong, W P

    2003-05-01

    Three preparations of type 1 ribosome inactivating proteins (RIPs), namely, agrostin, saporin, and luffin, were subjected to affinity chromatography on Red Sepharose and eluted with a linear concentration gradient of NaCl in 10 mM Tris-HCl buffer (pH 7.4). The eluate was assayed for ability to inhibit translation in a cell-free rabbit reticulocyte lysate system which measures RIP activity, and for ability to hydrolyze yeast transfer RNA which measures RNase activity. It was found that, in all three RIP preparations, the peak of RIP activity, which coincided with the peak of absorbance at 280 nm, was eluted earlier than the peak of RNase activity. It appears that RNase is a possible contaminant of ribosome inactivating protein preparations and that this contamination can be minimized by using Red Sepharose.

  9. Fluorescent boronic acid terminated polymer grafted silica particles synthesized via click chemistry for affinity separation of saccharides

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhifeng, E-mail: 897061147@qq.com; Deng, Peihong; Tang, Siping; Li, Junhua

    2014-07-01

    Boronic acids are important for effective separation of biological active cis-diols. For the purpose of constructing a new type of saccharide-sensitive material which can not only provide convenient separation but also improve the access of boronic acid to guest molecules, the fluorogenic boronic acid terminated, thermo-sensitive polymers (BA-polyNIPAm) were grafted to an alkyne modified silica gel through the exploitation of click chemistry. The BA-polyNIPAm grafted silica gel (BA-polyNIPAm-SG) was characterized by FT-IR, fluorescence spectra, fluorescence microscopy, elemental analysis (EA), thermal gravimetric analysis (TGA), scanning electron microscope (SEM) and so on. BA-polyNIPAm-SG displayed affinity binding ability for saccharides under physiological pH value and allowed saccharides to be conveniently separated from solution. The maximum binding capacities for fructose and glucose are 83.2 μmol/g and 70.4 μmol/g polymer, respectively. The intensity of fluorescence emission of BA-polyNIPAm-SG increased with the increasing of fructose concentration. The present study provides a new kind of composite material which contains moveable and flexible grippers for recognizing and binding guest molecules. - Highlights: • Fluorogenic boronic acid terminated polymers were conjugated to silica particle. • The prepared material can conveniently separate saccharides from solution. • The prepared material displays increased fluorescence emission upon binding fructose.

  10. Sialic acid-specific affinity chromatography for the separation of erythropoietin glycoforms using serotonin as a ligand.

    Science.gov (United States)

    Meininger, M; Stepath, M; Hennig, R; Cajic, S; Rapp, E; Rotering, H; Wolff, M W; Reichl, U

    2016-02-15

    Recombinant human erythropoietin (rhEPO) is an important CHO cell-derived glycoprotein and the degree of sialylation of this hormone is crucial for its in vivo bioactivity. In order to improve the purification process serotonin as a potential affinity ligand was tested for preparative chromatographic separation of rhEPO glycoforms into fractions of different degrees of sialylation. Therefore, two chromatographic matrices were prepared by immobilizing serotonin on CNBr- and NHS-Sepharose™. First it was shown both matrices bind rhEPO only in its sialylated form. Results indicate that binding is pH independent between pH 3.5 to 8 suggesting it is not only based on electrostatic interactions. Second, after optimal binding conditions were identified, semi-purified rhEPO was loaded onto both matrices and eluted using a stepwise elution gradient of sodium chloride. For comparison same affinity purification experiments were performed using wheat germ agglutinin-coupled agarose, a lectin known for its affinity towards sialylated glycoproteins. To monitor changes in N-glycan fingerprint, eluate fractions were analyzed by multiplexed capillary gel electrophoresis coupled to laser-induced fluorescence (xCGE-LIF). For the serotonin matrices an increasing degree of sialylation was observed from the first to the third elution fraction while purity of rhEPO could be increased at the same time. The late elution fractions of serotonin-coupled CNBr- and NHS-Sepharose™ also showed an overall sialylation degree exceeding that of the starting material. In contrast, for rhEPO bound to wheat germ agglutinin-coupled agarose, no distinct change in the degree of sialylation could be observed after elution. Overall, these encouraging results highlight the potential of serotonin as a chromatographic ligand for the improvement of pharmaceutical purification processes of rhEPO.

  11. Separation of plasminogen activator in bovine milk, and its various days after delivery

    OpenAIRE

    堀江, 登

    2000-01-01

    Plasminogen activator was separated by gel-filtration of skimmed milk from bovine until 9^ day after delivery. The separation pattern of plasminogen activator in bovine milk was different from one of human milk. The activities of plasminogen activator in bovine milk were compared among three groups of skimmed milk samples obtained in 1~3day, 4~6day, 7~9day after delivery. The mean value for each group were 3.2IU/ml(l~3day), 3.5IU/ml(4~6day) and 0.3IU/ml(4~9day).

  12. Diaminoalkane as Spacer Arm between Polystyrene and - Cylodextrin in Affinity Chromatography for -Amylase Separation

    Directory of Open Access Journals (Sweden)

    Sri Widarti* ,

    2014-02-01

    Full Text Available Stationary phase design in affinity chromatography has to fulfill at least two requirements: non-specific interaction between solid support and or spacer arm and protein target or others is minimal and specific interaction between ligand and protein target is maximal. In this study, stationary phases that consist of polystyrene (PS as solid support, diaminoalkane as spacer arm and with and without βCD as a ligand are performed in α-amylase separation. Therefore, the research was carried out in two steps; stationary phase preparation and adsorption parameter determination towards α-amylase. Stationary phases that consist of PS, 1,6-diaminohexane and βCD (PS–DAH–βCD and without βCD (PS–DAH were synthesized. Stationary phase structure was confirmed by FTIR, 13C NMR solid, 13C dan 1H NMR liquid spectroscopy. Other stationary phases, PS–DAP–βCD and PS–DAP that consist of 1,2-diaminopropane (DAP as spacer arm was synthesized in the previous research. Dynamic α-amylase adsorption isotherm on PS–DAP and PS–DAH shows that both of them did not fix any adsorption isotherm model. The average binding capacity are 0.071 and 0.31 mg/0.1 g resin, respectively. In another hand, PS–DAP–βCD and PS–DAH–βCD fix isotherm adsorption Langmuir model and the adsorption parameters; the maximum binding capacity (qm are 5.5 and 2.1 mg/0.1 g resin, adsorption equilibrium constant (KA are 0.01965 and 0.01925 μL—1 and desorption rate constant (k2 are 0.201 and 0.774 mg s—1 , respectively. Due to adsorption parameters, PS–DAP–βCD offer the best adsorption capacity and selectivity as stationary phase in affinity chromatography for α-amylase separation.

  13. Controlled multiple growth factor delivery from bone tissue engineering scaffolds via designed affinity.

    Science.gov (United States)

    Suárez-González, Darilis; Lee, Jae Sung; Diggs, Alisha; Lu, Yan; Nemke, Brett; Markel, Mark; Hollister, Scott J; Murphy, William L

    2014-08-01

    It is known that angiogenesis plays an important role in bone regeneration and that release of angiogenic and osteogenic growth factors can enhance bone formation. Multiple growth factors play key roles in processes that lead to tissue formation/regeneration during natural tissue development and repair. Therefore, treatments aiming to mimic tissue regeneration can benefit from multiple growth factor release, and there remains a need for simple clinically relevant approaches for dual growth factor release. We hypothesized that mineral coatings could be used as a platform for controlled incorporation and release of multiple growth factors. Specifically, mineral-coated scaffolds were "dip coated" in multiple growth factor solutions, and growth factor binding and release were dictated by the growth factor-mineral binding affinity. Beta tricalcium phosphate (β-TCP) scaffolds were fabricated using indirect solid-free form fabrication techniques and coated with a thin conformal mineral layer. Mineral-coated β-TCP scaffolds were sequentially dipped in recombinant human vascular endothelial growth factor (rhVEGF) and a modular bone morphogenetic peptide, a mineral-binding version of bone morphogenetic protein 2 (BMP2), solutions to allow for the incorporation of each growth factor. The dual release profile showed sustained release of both growth factors for over more than 60 days. Scaffolds releasing either rhVEGF alone or the combination of growth factors showed an increase in blood vessel ingrowth in a dose-dependent manner in a sheep intramuscular implantation model. This approach demonstrates a "modular design" approach, in which a controllable biologics carrier is integrated into a structural scaffold as a thin surface coating.

  14. Optical separation and controllable delivery of cells from particle and cell mixture

    Directory of Open Access Journals (Sweden)

    Li Yuchao

    2015-11-01

    Full Text Available Cell separation and delivery have recently gained significant attention in biological and biochemical studies. In thiswork, an optical method for separation and controllable delivery of cells by using an abruptly tapered fiber probe is reported. By launching a laser beam at the wavelength of 980 nm into the fiber, a mixture of cells with sizes of ~5 and ~3 μm and poly(methyl methacrylate particles with size of 5 μm are separated into three chains along the direction of propagation of light. The cell and particle chains are delivered in three dimensions over 600 μm distance. Experimental results are interpreted by numerical simulations. Optical forces and forward migration velocities of different particles and cells are calculated and discussed.

  15. Fractionation of the genetic variants of human alpha 1-acid glycoprotein in the native form by chromatography on an immobilized copper(II) affinity adsorbent. Heterogeneity of the separate variants by isoelectrofocusing and by concanavalin A affinity chromatography.

    Science.gov (United States)

    Hervé, F; Gomas, E; Duché, J C; Tillement, J P

    1993-05-19

    Fractionation of the three main genetic variants (F1, S and A) of human alpha 1-acid glycoprotein (AAG), in their native (sialylated) form, by chromatography on immobilized copper(II) affinity adsorbent was investigated. This chromatographic method had been previously developed to fractionate the desialylated protein variants. For that purpose, the three main AAG phenotypes samples (F1S/A, F1/A and S/A), which had been previously isolated from individual human plasma samples, and an AAG sample from commercial source (a mixture of the phenotypes) were used in the native form. Affinity chromatography of these different samples on an iminodiacetate Sepharose-copper(II) gel at pH 7 resolved two protein peaks, irrespective of the origin of the native AAG sample used. The unbound peak 1 was found to consist of the F1, the S or both variants, depending on the phenotype of the AAG sample used in the chromatography. The bound peak 2 was found to consist of the A variant in a pure form. The fractionation results obtained with native AAG were found to be the same as those originally yielded by the desialylated protein. However, comparison of the interactions of native and desialylated AAG with immobilized copper(II) ions, using an affinity chromatographic method and a non-chromatographic equilibrium binding technique, respectively, showed that desialylation increased the non-specific interactions of the protein with immobilized copper(II) ions. The AAG variants were not fractionated when affinity chromatography was performed using immobilized zinc, nickel or cobalt(II) ions, instead of copper. After purification of each variant in the sialylated form (F1, S and A), their respective heterogeneity was studied by analytical isoelectrofocusing with carrier ampholytes in the pH range 2.5-4.5. In addition, the lectin-binding behaviour of the separate sialylated AAG variants was investigated by affinity chromatography on immobilized concanavalin A.

  16. Synthetic Nano- and Micromachines in Analytical Chemistry: Sensing, Migration, Capture, Delivery, and Separation.

    Science.gov (United States)

    Duan, Wentao; Wang, Wei; Das, Sambeeta; Yadav, Vinita; Mallouk, Thomas E; Sen, Ayusman

    2015-01-01

    Synthetic nano- and microscale machines move autonomously in solution or drive fluid flows by converting sources of energy into mechanical work. Their sizes are comparable to analytes (sub-nano- to microscale), and they respond to signals from each other and their surroundings, leading to emergent collective behavior. These machines can potentially enable hitherto difficult analytical applications. In this article, we review the development of different classes of synthetic nano- and micromotors and pumps and indicate their possible applications in real-time in situ chemical sensing, on-demand directional transport, cargo capture and delivery, as well as analyte isolation and separation.

  17. Preparation and characterization of polysulfone affinity membranes bearing a synthetic peptide ligand for the separation of murine immunoglobulins.

    Science.gov (United States)

    Boi, Cristiana; Algeri, Cristian; Sarti, Giulio C

    2008-01-01

    Affinity membranes have been prepared by immobilizing D-PAM, a synthetic ligand that exhibits affinity for the Fc portion of antibodies, onto poliethersulfone microporous membranes. The ligand density has been measured and the ligand utilization was evaluated and compared with literature data available for chromatographic beads. The resulting new affinity membranes have been experimentally characterized and tested by using pure murine IgG solutions and mouse serum. Equilibrium and kinetic parameters have been obtained in batch experiments using pure protein solutions. The highest binding capacity measured for murine IgG was 45 microg/cm(2) obtained at 1.2 mg/mL protein concentration at equilibrium, while the maximum static binding capacity calculated with the Langmuir model was 81 microg/cm(2). The adsorption of murine IgG on the affinity membranes was described using different isotherms: Freundlich and Temkin models have been considered and critically compared with the Langmuir adsorption model. A dynamic binding capacity of 21 microg/cm(2) was obtained by feeding a solution of 0.3 mg/mL of murine IgG, confirming the results obtained in batch experiments at the same concentration. The affinity membranes considered are endowed with good binding capacity for murine IgG and good selectivity for immunoglobulins and can be considered for the capturing step of an antibody production process.

  18. L-histidine functionalized multi-walled carbon nanotubes for on-line affinity separation and purification of immunoglobulin G in serum.

    Science.gov (United States)

    Du, Zhuo; Zhang, Suling; Zhou, Chanyuan; Liu, Miao; Li, Gongke

    2012-09-15

    In this work, the multi-walled carbon nanotubes were covalently functionalized with L-histidine (His-MWNTs) as online pseudospecific affinity adsorbent for immunoglobulin G (IgG) separation and purification with a simple surface modification method, using 1-ethyl-3-(3-dimethyaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimde (NHS). The affinity of the His-MWNTs toward IgG was investigated in a microcolumn incorporated into a sequential injection system, which also involves an UV spectrometer with a flow cell for online real-time detection. The incorporation of histidine as affinity groups noticeably increased the selectivity and binding capacity of MWNTs for IgG and the His-MWNTs exhibited high retention and recovery rate of nearly 100% under optimized conditions. This separation and enrichment process made it possible to determine a lower concentration range of IgG in serum from 1.0-33 μg/mL with a detection limit of 0.3 μg/mL with a sampling volume of 4.0 mL. The static and dynamic adsorption capacities obtained were 267 mg of IgG/g His-MWNTs and 35 mg/g in aqueous solution, respectively, which are among the highest reported results in literatures employing affinity separation methods. Desorption of IgG from His-MWNTs could be accomplished by lowering the pH to 1.5 with glycine-HCl buffer. The practical application of His-MWNTs for separation of IgG in serum was evaluated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis which confirmed that the purity of recovered IgG from human serum was over 85% and better than a commercial product.

  19. Separating the mink dam from the litter at 7 or 8 weeks after delivery

    DEFF Research Database (Denmark)

    Malmkvist, Jens; Palme, Rupert; Larsen, Torben

    2015-01-01

    around the time of separation. Therefore, we investigated the effects of separating the dam from the litter, using brown first-parity dams (N=374) randomly assigned within each date of delivery to two treatment groups: The dam was taken away from the litter either at day 49 ±1 (7w, N=185) or at day 56 ±1......The optimal timing of separating the mink dam from the litter is suggested to be a balance between the partly conflicting needs of the mother and the kits. Early removal of the dam or partial removal of the litter may protect the dam against exhaustion. Little is known about the maternal motivation...... groups had an equal litter size at the time of separation (age 7w: 5.5 ±0.17; 8w: 5.5 ±0.17 kits; range 1-11; P=0.76). Likewise, there was no significant difference in dam body weight (7w: 1420 ±15.0 g, 8w: 1404 ±14.7 g; range 930-1680 g, P=0.43). However, the litter size negatively influenced both...

  20. Tailored functionalization of iron oxide nanoparticles for MRI, drug delivery, magnetic separation and immobilization of biosubstances.

    Science.gov (United States)

    Hola, Katerina; Markova, Zdenka; Zoppellaro, Giorgio; Tucek, Jiri; Zboril, Radek

    2015-11-01

    In this critical review, we outline various covalent and non-covalent approaches for the functionalization of iron oxide nanoparticles (IONPs). Tuning the surface chemistry and design of magnetic nanoparticles are described in relation to their applicability in advanced medical technologies and biotechnologies including magnetic resonance imaging (MRI) contrast agents, targeted drug delivery, magnetic separations and immobilizations of proteins, enzymes, antibodies, targeting agents and other biosubstances. We review synthetic strategies for the controlled preparation of IONPs modified with frequently used functional groups including amine, carboxyl and hydroxyl groups as well as the preparation of IONPs functionalized with other species, e.g., epoxy, thiol, alkane, azide, and alkyne groups. Three main coupling strategies for linking IONPs with active agents are presented: (i) chemical modification of amine groups on the surface of IONPs, (ii) chemical modification of bioactive substances (e.g. with fluorescent dyes), and (iii) the activation of carboxyl groups mainly for enzyme immobilization. Applications for drug delivery using click chemistry linking or biodegradable bonds are compared to non-covalent methods based on polymer modified condensed magnetic nanoclusters. Among many challenges, we highlight the specific surface engineering allowing both therapeutic and diagnostic applications (theranostics) of IONPs and magnetic/metallic hybrid nanostructures possessing a huge potential in biocatalysis, green chemistry, magnetic bioseparations and bioimaging.

  1. Lignin isolated from steam-exploded eucalyptus wood chips by phase separation and its affinity to Trichoderma reesei cellulase.

    Science.gov (United States)

    Nonaka, Hiroshi; Kobayashi, Ai; Funaoka, Masamitsu

    2013-07-01

    Steam-exploded eucalyptus wood chips were treated with p-cresol and 72% sulfuric acid at ambient temperature. Steam-exploded lignin was isolated as acetone-soluble and diethyl ether-insoluble compounds from the cresol layer. The lignin extraction yield was only 47%, and the amount of cresol grafted to lignin was much less than that in the case of eucalyptus lignin without steam explosion. Clearly, the steam explosion process depolymerized native lignin, and simultaneously, promoted polymerization via labile benzyl positions. The steam-exploded eucalyptus lignin adsorbed more Trichoderma reesei cellulase; however, its enzymatic activity was less than that of eucalyptus lignin that did not undergo steam explosion. It is evident that pretreatment potentially affects the affinity between lignin and cellulase and the resultant saccharification efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Separation of Binding Protein of Celangulin V from the Midgut of Mythimna separata Walker by Affinity Chromatography

    Directory of Open Access Journals (Sweden)

    Lina Lu

    2015-05-01

    Full Text Available Celangulin V, an insecticidal compound isolated from the root bark of Chinese bittersweet, can affect the digestive system of insects. However, the mechanism of how Celangulin V induces a series of symptoms is still unknown. In this study, affinity chromatography was conducted through coupling of Celangulin V-6-aminoacetic acid ester to the CNBr-activated Sepharose 4B. SDS-PAGE was used to analyze the collected fraction eluted by Celangulin V. Eight binding proteins (Zinc finger protein, Thioredoxin peroxidase (TPx, Glyceraldehyde 3-phosphate dehydrogenase (GAPDH, SUMO E3 ligase RanBP2, Transmembrane protein 1, Actin, APN and V-ATPase were obtained and identified by LC/Q-TOF-MS from the midgut of Mythimna separata larvae. The potential of these proteins to serve as target proteins involved in the insecticidal activity of Celangulin V is discussed.

  3. [PHEMA/PEI]-Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma.

    Science.gov (United States)

    Bakhshpour, Monireh; Derazshamshir, Ali; Bereli, Nilay; Elkak, Assem; Denizli, Adil

    2016-04-01

    The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]-Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50, 100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]-Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

  4. [PHEMA/PEI]–Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bakhshpour, Monireh; Derazshamshir, Ali; Bereli, Nilay [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey); Elkak, Assem [Laboratory of “Valorisation des Ressources Naturelles et Produits de Santé (VRNPS)”, Doctoral School of Sciences and Technology, Lebanese University, Rafic Hariri University Campus, Hadath (Lebanon); Denizli, Adil, E-mail: denizli@hacettepe.edu [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey)

    2016-04-01

    The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]–Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50, 100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH 7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]–Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). - Highlights: • Cu(II)-ions were coupled to PHEMA using PEI as the chelating ligand. • Cu(II) chelated [PHEMA/PEI] cryogels for IgG separation were produced. • Maximum IgG adsorption capacity

  5. Protein Delivery System Containing a Nickel-Immobilized Polymer for Multimerization of Affinity-Purified His-Tagged Proteins Enhances Cytosolic Transfer.

    Science.gov (United States)

    Postupalenko, Viktoriia; Desplancq, Dominique; Orlov, Igor; Arntz, Youri; Spehner, Danièle; Mely, Yves; Klaholz, Bruno P; Schultz, Patrick; Weiss, Etienne; Zuber, Guy

    2015-09-01

    Recombinant proteins with cytosolic or nuclear activities are emerging as tools for interfering with cellular functions. Because such tools rely on vehicles for crossing the plasma membrane we developed a protein delivery system consisting in the assembly of pyridylthiourea-grafted polyethylenimine (πPEI) with affinity-purified His-tagged proteins pre-organized onto a nickel-immobilized polymeric guide. The guide was prepared by functionalization of an ornithine polymer with nitrilotriacetic acid groups and shown to bind several His-tagged proteins. Superstructures were visualized by electron and atomic force microscopy using 2 nm His-tagged gold nanoparticles as probes. The whole system efficiently carried the green fluorescent protein, single-chain antibodies or caspase 3, into the cytosol of living cells. Transduction of the protease caspase 3 induced apoptosis in two cancer cell lines, demonstrating that this new protein delivery method could be used to interfere with cellular functions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. 用于清除胆红素的磁性亲和分离方法%Study on Removal of Bilirubin with Magnetic Affinity Separation Technique

    Institute of Scientific and Technical Information of China (English)

    徐辉; 张国亮; 张凤宝; 王淑兰

    2003-01-01

    An affinity adsorbent, Cibacron Blue 3GA immobilized magnetic polyvinyl alcohol (PVA) microsphereswas used for bilirubin removal taking the advantage of easy separation of magnetic sorbent from the biosystem.Fe3 O4 superparamagnetic particles was synthesized with hydrothermal reaction of ferrous chloride (FeCl2) and ferricchloride (FeCl3). Such magnetic particles are then encapsulated in biocompatible PVA to form magnetic polymermicrospheres sized from 2 to 15 nm with hydroxyl groups on its surface. Cibacron Blue 3GA, a dye-ligand, wascovalently coupled with the polyvinyl alcohol through the nucleophilic reaction between the chloride of its triazinering and the hydroxyl groups of PVA molecules under alkaline condition. The affinity adsorbent carried 21.1 μmolCibacron Blue 3GA per gram magnetic polymer microspheres was used to remove unconjugated and conjugatedbilirubin from the solution which was composed of bilirubin or bilirubin and protein. After the adsorption, theadsorbent loaded with bilirubin was removed easily in the magnetic field.

  7. Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads for magnetic affinity separation of histidine-tagged proteins.

    Science.gov (United States)

    Vereshchagina, T A; Fedorchak, M A; Sharonova, O M; Fomenko, E V; Shishkina, N N; Zhizhaev, A M; Kudryavtsev, A N; Frank, L A; Anshits, A G

    2016-01-28

    Magnetic Ni(2+)-zeolite/ferrosphere and Ni(2+)-silica/ferrosphere beads (Ni-ferrosphere beads - NFB) of a core-shell structure were synthesized starting from coal fly ash ferrospheres having diameters in the range of 0.063-0.050 mm. The strategy of NFB fabrication is an oriented chemical modification of the outer surface preserving the magnetic core of parent beads with the formation of micro-mesoporous coverings. Two routes of ferrosphere modification were realized, such as (i) hydrothermal treatment in an alkaline medium resulting in a NaP zeolite layer and (ii) synthesis of micro-mesoporous silica on the glass surface using conventional methods. Immobilization of Ni(2+) ions in the siliceous porous shell of the magnetic beads was carried out via (i) the ion exchange of Na(+) for Ni(2+) in the zeolite layer or (ii) deposition of NiO clusters in the zeolite and silica pores. The final NFB were tested for affinity in magnetic separation of the histidine-tagged green fluorescent protein (GFP) directly from a cell lysate. Results pointed to the high affinity of the magnetic beads towards the protein in the presence of 10 mM EDTA. The sorption capacity of the ferrosphere-based Ni-beads with respect to GFP was in the range 1.5-5.7 mg cm(-3).

  8. Ionization Energies, Electron Affinities, and Polarization Energies of Organic Molecular Crystals: Quantitative Estimations from a Polarizable Continuum Model (PCM)–Tuned Range-Separated Density Functional Approach

    KAUST Repository

    Sun, Haitao

    2016-05-16

    We propose a new methodology for the first-principles description of the electronic properties relevant for charge transport in organic molecular crystals. This methodology, which is based on the combination of a non-empirical, optimally tuned range-separated hybrid functional with the polarizable continuum model, is applied to a series of eight representative molecular semiconductor crystals. We show that it provides ionization energies, electron affinities, and transport gaps in very good agreement with experimental values as well as with the results of many-body perturbation theory within the GW approximation at a fraction of the computational costs. Hence, this approach represents an easily applicable and computationally efficient tool to estimate the gas-to-crystal-phase shifts of the frontier-orbital quasiparticle energies in organic electronic materials.

  9. Affinity composite cryogel discs functionalized with Reactive Red 120 and Green HE 4BD dye ligands: Application on the separation of human immunoglobulin G subclasses

    Energy Technology Data Exchange (ETDEWEB)

    Huseynli, Sabina; Baydemir, Gözde; Sarı, Esma [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey); Elkak, Assem [Laboraory of “Valorisation des Ressources Naturelles et Produits de Santé (VRNPS)”, Doctoral School of Sciences and Technology, Lebanese University, Rafic Hariri University Campus, Hadath (Lebanon); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey)

    2015-01-01

    Naturally produced by the human immune system, immunoglobulin nowadays is widely used for in vivo and in vitro purposes. The increased needs for pure immunoglobulin have prompted researchers to find new immunoglobulin chromatographic separation processes. Cryogels as chromatographic adsorbents, congregate several mechanical features including good compatibility, large pore structure, flexibility, short diffusion pathway and stability. These different characteristics make them a good alternative to conventional chromatographic methods and allowing their potential use in separation technology. In the present study, two sets of poly(2-hydroxyethyl methacrylate) (PHEMA) based beads were prepared and functionalized with Reactive Red 120 (RR) and Reactive Green HE 4BD (RG) dyes, and then embedded into supermacroporous cryogels. The morphology, physical and chemical features of the prepared bead embedded composite cryogel discs (CCDs) were performed by scanning electron microscopy (SEM), swelling test, elemental analysis and Fourier transform infrared spectroscopy (FTIR). The results showed that the embedded composite cryogel discs have a specific surface area of 192.0 m{sup 2}/g with maximum adsorption capacity of HIgG 239.8 mg/g for the RR functionalized CCD and 170 mg/g for RG functionalized CCD columns, both at pH 6.2. - Highlights: • Dye attached composite cryogel discs were prepared to separate HIgG subclasses. • Composite cryogels characterized by swelling, FTIR, SEM and elemental analysis. • Reactive Green HE 4B and Reactive Red 120 dyes were used as the affinity ligand. • HIgG and subclasses were separate from both aqueous solution and human plasma.

  10. New approach for separating Bacillus subtilis metalloprotease and alpha-amylase by affinity chromatography and for purifying neutral protease by hydrophobic chromatography.

    Science.gov (United States)

    Lauer, I; Bonnewitz, B; Meunier, A; Beverini, M

    2000-01-14

    Proteases are commonly used in the biscuit and cracker industry as processing aids. They cause moderate hydrolysis of gluten proteins and improve dough rheology to better control product texture and crunchiness. Commercial bacterial proteases are derived from Bacillus fermentation broth. As filtration and ultrafiltration are carried out as the only recovery steps, these preparations contain also alpha-amylase and beta-glucanase as the main side activities. The aim of this study is to purify and characterize the Bacillus subtilis metalloprotease from a commercial preparation, in order to study separately the impact of the protease activity with regards to its functionality on biscuit properties. Purification was achieved by means of affinity chromatography on Cibacron Blue and HIC as a polishing step. Affinity appeared to be the most appropriate matrix for large scale purification while ion exchange chromatography was inefficient in terms of recovery yields. The crude product was first loaded on a Hi Trap Blue column (34 microm, Pharmacia Biotech); elution was carried out with a gradient of NaCl in the presence of 1 mM ZnCl2. This step was only efficient in the presence of Zn cations, because this salt promoted both protease stabilization resulting in high recovery yields and also complexation of amylase units into dimers resulting in amylase retention on the column and a better separation of the 3 activities. Beta-glucanase was mostly non retained on the column and a part was coeluted with the protease. This protease fraction was then loaded on a Resource Phe column (15 microm, Pharmacia Biotech) in a last step of polishing. Elution was carried out with a linear gradient of 100-0% ammonium sulfate 1.3 M; protease was eluted at the beginning of the gradient and well separated from amylase and glucanase trace impurities. The homogeneity of the purified protease was confirmed by SDS-PAGE, which showed that its MW was about 38. pH and temperature optima were also

  11. Separation and quantitation of hepatoma-associated gamma-glutamyltransferase by affinity chromatography with Affi-Gel blue and Con A-Sepharose.

    Science.gov (United States)

    Izumi, M; Taketa, K

    1983-01-01

    Isozymes of serum gamma-glutamyltransferase (GGT) in patients with hepatocellular carcinoma (HCC) and other liver diseases were separated into two groups by double-affinity column chromatography with Affi-Gel blue and Con A-Sepharose, one recovered in the unbound fraction and the other in the bound fraction. Upon electrophoresis with polyacrylamide gradient gel slabs, the unbound fraction gave a GGTI1 band and a faint II1 band and the bound fraction gave a GGT I band and faint bands of GGT I", II' and X, when the original serum contained hepatoma-associated GGT (I1, I" and II') and high-molecular-weight lipid-protein complex, GGT(X). GGT I was present in all cases as a common isozyme. Other lipoprotein-associated GGT isozymes, III-IX, were removed by passing through Affi-Gel blue. GGT activities of unbound fraction in patients with HCC were generally higher than those in patients with non-HCC liver diseases, although the difference was not significant. When the percent of GGT activity of unbound (unbound + bound) was taken, 54% of patients with HCC had a ratio greater than 22%, whereas none of the healthy subjects or patients with other liver diseases gave values greater than this. The present technique may prove to be a useful clinical test for the diagnosis of HCC.

  12. The effects of co-delivery of BMSC-affinity peptide and rhTGF-β1 from coaxial electrospun scaffolds on chondrogenic differentiation.

    Science.gov (United States)

    Man, Zhentao; Yin, Ling; Shao, Zhenxing; Zhang, Xin; Hu, Xiaoqing; Zhu, Jingxian; Dai, Linghui; Huang, Hongjie; Yuan, Lan; Zhou, Chunyan; Chen, Haifeng; Ao, Yingfang

    2014-06-01

    Electrospinning is a promising technology for the fabrication of scaffolds in cartilage tissue engineering. Two other important elements for tissue engineering are seed cells and bioactive factors. Bone marrow-derived stem cells (BMSCs) and rhTGF-β1 are extensively studied for cartilage regeneration. However, little is known about scaffolds that can both specifically enrich BMSCs and release rhTGF-β1 to promote chondrogenic differentiation of the incorporated BMSCs. In this study, we first fabricated coaxial electrospun fibers using a polyvinyl pyrrolidone/bovine serum albumin/rhTGF-β1 composite solution as the core fluid and poly(ε-caprolactone) solution as the sheath fluid. Structural analysis revealed that scaffold fibers were relatively uniform with a diameter of 674.4 ± 159.6 nm; the core-shell structure of coaxial fibers was homogeneous and proteins were evenly distributed in the core. Subsequently, the BMSC-specific affinity peptide E7 was conjugated to the coaxial electrospun fibers to develop a co-delivery system of rhTGF-β1 and E7. The results of (1)H nuclear magnetic resonance indicate that the conjugation between the E7 and scaffolds was covalent. The rhTGF-β1 incorporated in E7-modified scaffolds could maintain sustained release and bioactivity. Cell adhesion, spreading, and DNA content analyses indicate that the E7 promoted BMSC initial adhesion, and that the scaffolds containing both E7 and rhTGF-β1 (CBrhTE) were the most favorable for BMSC survival. Meanwhile, CBrhTE scaffolds could promote the chondrogenic differentiation ability of BMSCs. Overall, the CBrhTE scaffold could synchronously improve all three of the basic components required for cartilage tissue engineering in vitro, which paves the road for designing and building more efficient tissue scaffolds for cartilage repair.

  13. Betaglycan has two independent domains required for high affinity TGF-β binding: proteolytic cleavage separates the domains and inactivates the neutralizing activity of the soluble receptor

    Science.gov (United States)

    Mendoza, Valentín; Vilchis-Landeros, M. Magdalena; Mendoza-Hernández, Guillermo; Huang, Tao; Villarreal, Maria M.; Hinck, Andrew P.; López-Casillas, Fernando; Montiel, Jose-Luis

    2009-01-01

    Summary Betaglycan is a co-receptor for members of the TGF-β superfamily. Mutagenesis has identified two ligand binding regions, one at the membrane-distal and the other at the membrane-proximal half of the betaglycan ectodomain. Here we show that partial plasmin digestion of soluble betaglycan produces two proteolysis-resistant fragments of 45 and 55 kDa, consistent with the predicted secondary structure, which indicates an intervening non-structured linker region separating the highly structured N- and C-terminal domains. Amino terminal sequencing indicates that the 45 and 55 kDa fragments correspond, respectively, to the membrane-distal and -proximal regions. Plasmin treatment of membrane betaglycan results in the production of equivalent proteolysis-resistant fragments. The 45 and 55 kDa fragments, as well as their recombinant soluble counterparts, Sol Δ10 and Sol Δ11, bind TGF-β, nonetheless, compared to intact soluble betaglycan, have severely diminished ability to block TGF-β activity. Surface plasmon resonance (SPR) analysis indicates that soluble betaglycan has Kds in the low nanomolar range for the three TGF-β isoforms, while those for Sol Δ10 and Sol Δ11 are 1 – 2 orders of magnitude higher. SPR analysis further shows that the Kds of Sol Δ11 are not changed in the presence of Sol Δ10, indicating that the high affinity of soluble betaglycan is a consequence of tethering of the domains together. Overall, these results, suggest that betaglycan ectodomain exhibits a bi-lobular structure in which each lobule folds independently, binds TGF-β through distinct non-overlapping interfaces, and that linker modification may be an approach to improve soluble betaglycan’s TGF-β neutralizing activity. PMID:19842711

  14. Structure, morphology and cell affinity of poly(L-lactide) films surface-functionalized with chitosan nanofibers via a solid–liquid phase separation technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jianhao, E-mail: jhzhao@jnu.edu.cn [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Han, Wanqing; Tang, Minjian [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Tu, Mei; Zeng, Rong [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China); Liang, Zhihong [Analytical and Testing Center, Jinan University, Guangzhou 510632 (China); Zhou, Changren [Department of Materials Science and Engineering, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Engineering Research Center of Artificial Organs and Materials, Ministry of Education, Guangzhou 510632 (China)

    2013-04-01

    Poly(L-lactide) films with a nano-structured surface by immobilizing chitosan nanofibers (CSNFs) for improving the cell affinity were fabricated via a solid-liquid phase separation technique. The successful grafting of CSNFs on the surface of poly(L-lactide) films was confirmed by the binding energy of N1s at 398.0 eV in the X-ray photoelectron spectroscopy and the amide I and II bands of chitosan at 1650 and 1568 cm{sup −1} in the Fourier transform infrared spectroscopy. Compared with the poly(L-lactide) film, the hydrophilicity was improved with a lower water contact angle of 83.3 ± 1.9° and 75.3 ± 2.5° for the CSNFs-grafted and CSNFs-grafted/anchored poly(L-lactide) films respectively. The scanning electron microscopy and atomic force microscopy analyses showed that the grafted CSNFs with 50–500 nm in diameter were randomly arranged on the film surface and entangled with the anchored CSNFs on the outermost layer. The 3T3 fibroblasts culture indicated cells tended to attach and stretch along the CSNFs on the film surface. The cell viability measurement revealed that among all the samples, the film with both grafted and anchored CSNFs exhibited the highest cell proliferation rate that was twice as much of the poly(L-lactide) film at 7 d. Herein, engineering a nano-structured surface by solid–liquid phase separation will be a promising tool for surface modification of biomaterials. Highlights: ► A surface nano-structured poly(L-lactide) film with chitosan nanofibers was prepared. ► Grafted and anchored chitosan nanofibers were obtained by different treatment ways. ► Hydrophilicity was improved by immobilizing chitosan nanofibers on the film surface. ► Cell viability was enhanced on modified poly(L-lactide) film with chitosan nanofibers. ► Cells tended to attach and stretch along chitosan nanofibers on the film surface.

  15. 亲和胶质气体泡沫的制备及其对胰蛋白酶的吸附分离特性%PREPARATION OF AFFINITY-BASED COLLOIDAL GAS APHRONS FOR SELECTIVE ADSORPTION AND SEPARATION OF TRYPSIN

    Institute of Scientific and Technical Information of China (English)

    何彬; 刘杨; 孙彦

    2004-01-01

    Triton X-114, an non-ionic surfactant, was modified with the affinity ligand of trypsin, paminobenzamidine (PAB) and the affinity surfactant (PAB-TX) was synthesized. Then, the affinity surfactant was used to prepare affinity-based colloidal gas aphrons (CGA). The stability of the affinity CGA was investigated at different temperatures and compared with that of the CGA prepared from Triton X-114. Compared with the CGA from Triton X-114, the affinity CGA showed high selective adsorption property for trypsin. In the separation of a protein mixture, recovery yield higher than 74% were achieved for trypsin and the separation factor reached over 1.5. The results showed that the affinity CGA possessed promising selectivity for separating trypsin from a protein mixture.

  16. A high-efficiency, low-toxicity, phospholipids-based phase separation gel for long-term delivery of peptides.

    Science.gov (United States)

    Zhang, Ting; Peng, Qiang; San, Feng-Ying; Luo, Jing-Wen; Wang, Meng-Xin; Wu, Wen-Qi; Gong, Tao; Zhang, Zhi-Rong

    2015-03-01

    Peptide and protein drugs are currently under rapid development attributed to their high potency and efficacy in therapy. Their successful delivery, however, is highly limited by their short half-life, fast degradation and rapid clearance. Here, we present a high content phospholipids-based phase separation gel (PPSG), which is readily injectable due to its low initial viscosity and can rapidly transform into an in situ implant after injection upon exposure to an aqueous environment. A selected model peptide, octreotide acetate, is loaded into PPSG and achieves sustained release profiles for one month in rats. In addition, the local irritation caused by ethanol contained in PPSG is ethanol content-dependent and the irritation of PPSG with 70% phospholipids content can be eliminated by partially replacing ethanol with medium chain triglyceride. The mechanisms underlying phase transition of PPSG are based on water-insolubility of phospholipids. Our findings demonstrate that PPSG is a readily injectable, highly safe and efficient in situ forming implant for sustained delivery of peptides.

  17. Providing affinity

    DEFF Research Database (Denmark)

    Guglielmi, Michel; Johannesen, Hl

    2004-01-01

    This paper will introduce a project sourced by an ideas competition called Landmark East England. It was open to anyone with the ability to develop and deliver a visionary idea for a landmark. A sustainable icon representing a new region in England, which comprises Bedfordshire, Cambridgeshire......, Essex, Hertfordshire, Norfolk and Suffolk. Research found that there was a lack of identity or sense of belonging and nothing anchoring people to the region as a whole. Common affinity is somehow forced to the people of East England and thereby we came to the conclusion that a single landmark...... or a series of landmarks would do little to achieve true affinity. Therefore, we based our design strategy in trying to elaborate an alternatereality based on fabulation, virtualization and narratives that we subtly interweaved into architectonic structures (fabric) of the real. We have created plots...

  18. Separation and characterization of anti-benzylpenicilloyl (BPO) antibodies. I. Biochemical and biophysical properties of anti-BPO-IgG obtained by affinity and subsequent ion-exchange chromatography.

    Science.gov (United States)

    Scheiner, O; Stemberger, H; Kraft, D; Wiedermann, G

    1978-01-01

    Anti-BPO antibodies were purified by means of affinity chromatography using AH-Sepharose 4B coated with covalently bound BPO groups. Specific elution was achieved by the hapten analogue BPO-epsilon-aminocaproic acid (BPO-EACA); desorption of the remaining antibody was performed thereafter by 0.1 M acetic acid. The resulting antibody fractions--hapten-eluted antibody (H-Ab) and acid eluted antibody (A-Ab), respectively--were further separated by ion-exchange chromatography which led to the appearance of 3 subfractions in the case of H-Ab (H1, H2, H3) and 2 subfractions in the case of A-Ab (A1 and A2). In liquid isoelectrofocusing an inhomogeneous pattern resulted. The bulk of antibodies focused between pH 6.5 and 7.0. The average avidity of H-Ab was found to be higher than that of A-Ab suggesting that avidity may influence the elution pattern in affinity chromatography. The hydrophobic influence of the "spacer" and/or interactions of antibodies directed against the hydrophobic regions of the BPO group may explain why a considerable part of the antibodies could be recovered from the immunosorbent only by acid elution.

  19. Separation of the subtypes of type V collagen molecules, [alpha 1(V)]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V), by chain composition-dependent affinity for heparin: single alpha 1(V) chain shows intermediate heparin affinity between those of the type V collagen subtypes composed of [alpha 1(V)]2 alpha 2(V) and of alpha 1(V) alpha 2(V) alpha 3(V).

    Science.gov (United States)

    Mizuno, K; Hayashi, T

    1996-11-01

    The heparin affinities of heat-treated type V collagen alpha-chains and the triple-helical molecules were evaluated in terms of the NaCl concentration required for prevention of binding to a heparin-Sepharose column. After heat treatment, alpha 1(V) chain required approximately two-fold higher NaCl concentration to pass through the column than the other two chains, alpha 2(V) and alpha 3(V). Thus, the heparin affinity of alpha 1(V) may be approximately two-fold higher than those of the other alpha (V)-chains. The type V collagen molecules in triple-helical conformation were separated into two fractions at 170 mM NaCl in 20 mM phosphate buffer, pH 7.2, containing 2 M urea; bound and non-bound. The ratio of the three alpha-chains, alpha 1(V): alpha 2(V): alpha 3(V) was 2 : 1 : 0 and 1 : 1 : 1 in the bound and flow-through fractions, respectively, on analysis by SDS-PAGE. The differential affinity of the two fractions could be accounted for by the number of alpha 1(V) chains in the triple-helical molecule, if these fractions contained triple-helical subtypes with the chain compositions of [alpha 1(V)]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V), respectively. From the comparison of the NaCl concentration required for prevention of the binding, [alpha 1(V)]2, alpha 2(V) had about two-fold higher affinity than alpha 1(V) alpha 2(V) alpha 3(V), and the separated alpha 1(V) chain showed an intermediate affinity. A possible explanation for difference in heparin affinity among the subtypes of molecules and the separated alpha-chains is that the heparin affinity of type V collagen molecule is governed by the number of alpha 1(V) chains contained in the molecule and that steric restraint in a triple-helical conformation weakens the binding of alpha 1(V) chain to heparin.

  20. Electrospun Polymer Blend Nanofibers for Tunable Drug Delivery: The Role of Transformative Phase Separation on Controlling the Release Rate.

    Science.gov (United States)

    Tipduangta, Pratchaya; Belton, Peter; Fábián, László; Wang, Li Ying; Tang, Huiru; Eddleston, Mark; Qi, Sheng

    2016-01-01

    Electrospun fibrous materials have a wide range of biomedical applications, many of them involving the use of polymers as matrices for incorporation of therapeutic agents. The use of polymer blends improves the tuneability of the physicochemical and mechanical properties of the drug loaded fibers. This also benefits the development of controlled drug release formulations, for which the release rate can be modified by altering the ratio of the polymers in the blend. However, to realize these benefits, a clear understanding of the phase behavior of the processed polymer blend is essential. This study reports an in depth investigation of the impact of the electrospinning process on the phase separation of a model partially miscible polymer blend, PVP K90 and HPMCAS, in comparison to other conventional solvent evaporation based processes including film casting and spin coating. The nanoscale stretching and ultrafast solvent removal of electrospinning lead to an enhanced apparent miscibility between the polymers, with the same blends showing micronscale phase separation when processed using film casting and spin coating. Nanoscale phase separation in electrospun blend fibers was confirmed in the dry state. Rapid, layered, macroscale phase separation of the two polymers occurred during the wetting of the fibers. This led to a biphasic drug release profile from the fibers, with a burst release from PVP-rich phases and a slower, more continuous release from HPMCAS-rich phases. It was noted that the model drug, paracetamol, had more favorable partitioning into the PVP-rich phase, which is likely to be a result of greater hydrogen bonding between PVP and paracetamol. This led to higher drug contents in the PVP-rich phases than the HPMCAS-rich phases. By alternating the proportions of the PVP and HPMCAS, the drug release rate can be modulated.

  1. Porosity of Self-affine Sets

    Institute of Scientific and Technical Information of China (English)

    Lifeng XI

    2008-01-01

    In this paper,it is proved that any self-affine set satisfying the strong separation condition is uniformly porous.The author constructs a self-affine set which is not porous,although the open set condition holds.Besides,the author also gives a C1 iterated function system such that its invariant set is not porous.

  2. Fan affinity laws from a collision model

    CERN Document Server

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated from hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this work we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan.

  3. Cavity Design, Fabrication and Commission Performance of a 750MHz, 4-rod Separator for CEBAF 4-Hall Beam Delivery System

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haipeng [Jefferson Lab, Newport News, VA; Cheng, Guangfeng [Jefferson Lab, Newport News, VA; Turlington, Larry T. [Jefferson Lab, Newport News, VA; Wissmann, Mark J. [Jefferson Lab, Newport News, VA

    2015-09-01

    A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced **. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification.

  4. On affine rigidity

    CERN Document Server

    Gortler, Steven J; Liu, Ligang; Thurston, Dylan P

    2010-01-01

    We study the properties of affine rigidity of a hypergraph and prove a variety of fundamental results. First, we show that affine rigidity is a generic property (i.e., depends only on the hypergraph, not the particular embedding). Then we prove that a graph is generically neighborhood affinely rigid in d-dimensional space if it is (d+1)-vertex-connected. We also show neighborhood affine rigidity of a graph implies universal rigidity of its squared graph. Our results, and affine rigidity more generally, have natural applications in point registration and localization, as well as connections to manifold learning.

  5. On affine rigidity

    Directory of Open Access Journals (Sweden)

    Steven J. Gortler

    2013-12-01

    Full Text Available We study the properties of affine rigidity of a hypergraph and prove a variety of fundamental results. First, we show that affine rigidity is a generic property (i.e., depends only on the hypergraph, not the particular embedding. Then we prove that a graph is generically neighborhood affinely rigid in d-dimensional space if it is (d+1-vertex-connected. We also show neighborhood affine rigidity of a graph implies universal rigidity of its squared graph.  Our results, and affine rigidity more generally, have natural applications in point registration and localization, as well as connections to manifold learning.

  6. Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, N H; Sen, J W; Nissen, Mogens Holst

    2000-01-01

    The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of......The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red...

  7. 亲和毛细管电泳、环糊精-电动色谱、毛细管电泳-质谱用于对映体分离的研究进展%Method Development of Enantiomer Separations by Affinity Capillary Electrophoresis,Cyclodextrin Electrokinetic Chromatography and Capillary Electrophoresis-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Capillary electrophoresis (CE) has become a powerful tool for enantiomer separat ions during the last decade. Since 1993, the author has investigated enantiomer separations by affinity capillary electrophoresis (affinity CE) with some prote ins and by cyclodextrin electrokinetic chromatography (CDEKC) with some charged cyclodextrins (CDs). Many successful enantiomer separations are demonstrated f rom our study in this review article. In the enantiomer separations by affinit y CE, the deterioration of detection sensitivity was observed under high concent ration of the protein in running solutions. The partial filling technique was practically useful to solve the serious problem. It allowed operation at high protein concentrations, such as 500 μmol/L, without the detection problem. Cha rged CDs had several advantages for the enantiomer separations over neutral ones . Strong electrostatic interactions between a charged CD and oppositely charged analytes should be effective for the formation of the complex. A large differen ce in electrophoretic mobility between the free analyte and the inclusion comple x should also enhance the enantiomeric resolution. In CEmass spectrometry (CE MS), the partial filling technique was applied to avoid the introduction of no nvolatile chiral selectors into the CEMS interface. By replacing the nonvolat ile electrolytes in the running buffer by volatile ones, the separation conditio ns employed in CE with the UV detection method could be transferred to CEMS.

  8. Affine Dynamics with Torsion

    CERN Document Server

    Gultekin, Kemal

    2015-01-01

    In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on determinants of the Ricci tensor, torsion tensor, Riemann tensor and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to construction of the affine connection in terms of curvature and torsion tensors. Our solutions of the dynamical equations show that curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor.

  9. Continuous affine processes

    DEFF Research Database (Denmark)

    Buchardt, Kristian

    2016-01-01

    Affine processes possess the property that expectations of exponential affine transformations are given by a set of Riccati differential equations, which is the main feature of this popular class of processes. In this paper we generalise these results for expectations of more general transformati...

  10. Axioms of affine buildings

    OpenAIRE

    Schwer, Petra N.

    2009-01-01

    We prove equivalence of certain axiom sets for affine buildings. Along the lines a purely combinatorial proof of the existence of a spherical building at infinity is given. As a corollary we obtain that ``being an affine building'' is independent of the metric structure of the space.

  11. Lectin affinity chromatography of glycolipids

    Energy Technology Data Exchange (ETDEWEB)

    Torres, B.V.; Smith, D.F.

    1987-05-01

    Since glycolipids (GLs) are either insoluble or form mixed micelles in water, lectin affinity chromatography in aqueous systems has not been applied to their separation. They have overcome this problem by using tetrahydrofuran (THF) in the mobile phase during chromatography. Affinity columns prepared with the GalNAc-specific Helix pomatia agglutinin (HPA) and equilibrated in THF specifically bind the (/sup 3/H)oligosaccharide derived from Forssman GL indicating that the immobilized HPA retained its carbohydrate-binding specificity in this solvent. Intact Forssman GL was bound by the HPA-column equilibrated in THF and was specifically eluted with 0.1 mg/ml GalNAc in THF. Purification of the Forssman GL was achieved when a crude lipid extract of sheep erythrocyte membranes was applied to the HPA-column in THF. Non-specifically bound GLs were eluted from the column using a step gradient of aqueous buffer in THF, while the addition of GalNAc was required to elute the specifically bound GLs. Using this procedure the A-active GLs were purified from a crude lipid extract of type A human erythrocytes in a single chromatographic step. The use of solvents that maintain carbohydrate-binding specificity and lipid solubility will permit the application of affinity chromatography on immobilized carbohydrate-binding proteins to intact GLs.

  12. The Cutting Edge of Affinity Electrophoresis Technology

    Directory of Open Access Journals (Sweden)

    Eiji Kinoshita

    2015-03-01

    Full Text Available Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years.

  13. The Cutting Edge of Affinity Electrophoresis Technology

    Science.gov (United States)

    Kinoshita, Eiji; Kinoshita-Kikuta, Emiko; Koike, Tohru

    2015-01-01

    Affinity electrophoresis is an important technique that is widely used to separate and analyze biomolecules in the fields of biology and medicine. Both quantitative and qualitative information can be gained through affinity electrophoresis. Affinity electrophoresis can be applied through a variety of strategies, such as mobility shift electrophoresis, charge shift electrophoresis or capillary affinity electrophoresis. These strategies are based on changes in the electrophoretic patterns of biological macromolecules that result from interactions or complex-formation processes that induce changes in the size or total charge of the molecules. Nucleic acid fragments can be characterized through their affinity to other molecules, for example transcriptional factor proteins. Hydrophobic membrane proteins can be identified by means of a shift in the mobility induced by a charged detergent. The various strategies have also been used in the estimation of association/disassociation constants. Some of these strategies have similarities to affinity chromatography, in that they use a probe or ligand immobilized on a supported matrix for electrophoresis. Such methods have recently contributed to profiling of major posttranslational modifications of proteins, such as glycosylation or phosphorylation. Here, we describe advances in analytical techniques involving affinity electrophoresis that have appeared during the last five years.

  14. Affine and Projective Geometry

    CERN Document Server

    Bennett, M K

    1995-01-01

    An important new perspective on AFFINE AND PROJECTIVE GEOMETRY. This innovative book treats math majors and math education students to a fresh look at affine and projective geometry from algebraic, synthetic, and lattice theoretic points of view. Affine and Projective Geometry comes complete with ninety illustrations, and numerous examples and exercises, covering material for two semesters of upper-level undergraduate mathematics. The first part of the book deals with the correlation between synthetic geometry and linear algebra. In the second part, geometry is used to introduce lattice theory

  15. Affinity in electrophoresis.

    Science.gov (United States)

    Heegaard, Niels H H

    2009-06-01

    The journal Electrophoresis has greatly influenced my approaches to biomolecular affinity studies. The methods that I have chosen as my main tools to study interacting biomolecules--native gel and later capillary zone electrophoresis--have been the topic of numerous articles in Electrophoresis. Below, the role of the journal in the development and dissemination of these techniques and applications reviewed. Many exhaustive reviews on affinity electrophoresis and affinity CE have been published in the last few years and are not in any way replaced by the present deliberations that are focused on papers published by the journal.

  16. Affine dynamics with torsion

    Energy Technology Data Exchange (ETDEWEB)

    Gueltekin, Kemal [Izmir Institute of Technology, Department of Physics, Izmir (Turkey)

    2016-03-15

    In this study, we give a thorough analysis of a general affine gravity with torsion. After a brief exposition of the affine gravities considered by Eddington and Schroedinger, we construct and analyze different affine gravities based on the determinants of the Ricci tensor, the torsion tensor, the Riemann tensor, and their combinations. In each case we reduce equations of motion to their simplest forms and give a detailed analysis of their solutions. Our analyses lead to the construction of the affine connection in terms of the curvature and torsion tensors. Our solutions of the dynamical equations show that the curvature tensors at different points are correlated via non-local, exponential rescaling factors determined by the torsion tensor. (orig.)

  17. Affine and degenerate affine BMW algebras: Actions on tensor space

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2012-01-01

    The affine and degenerate affine Birman-Murakami-Wenzl (BMW) algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic quantum groups and Lie algebras, respectively. Cyclotomic BMW algebras, affine and cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper we explain how the affine and degenerate affine BMW algebras are tantalizers (tensor power centralizer algebras) by defining actions of the affine braid group and the degenerate affine braid algebra on tensor space and showing that, in important cases, these actions induce actions of the affine and degenerate affine BMW algebras. We then exploit the connection to quantum groups and Lie algebras to determine universal parameters for the affine and degenerate affine BMW algebras. Finally, we show that the universal parameters are central elements--the higher Casimir elements for orthogonal and symplectic enveloping algebras and quantum groups.

  18. Affine Sphere Relativity

    Science.gov (United States)

    Minguzzi, E.

    2016-11-01

    We investigate spacetimes whose light cones could be anisotropic. We prove the equivalence of the structures: (a) Lorentz-Finsler manifold for which the mean Cartan torsion vanishes, (b) Lorentz-Finsler manifold for which the indicatrix (observer space) at each point is a convex hyperbolic affine sphere centered on the zero section, and (c) pair given by a spacetime volume and a sharp convex cone distribution. The equivalence suggests to describe (affine sphere) spacetimes with this structure, so that no algebraic-metrical concept enters the definition. As a result, this work shows how the metric features of spacetime emerge from elementary concepts such as measure and order. Non-relativistic spacetimes are obtained replacing proper spheres with improper spheres, so the distinction does not call for group theoretical elements. In physical terms, in affine sphere spacetimes the light cone distribution and the spacetime measure determine the motion of massive and massless particles (hence the dispersion relation). Furthermore, it is shown that, more generally, for Lorentz-Finsler theories non-differentiable at the cone, the lightlike geodesics and the transport of the particle momentum over them are well defined, though the curve parametrization could be undefined. Causality theory is also well behaved. Several results for affine sphere spacetimes are presented. Some results in Finsler geometry, for instance in the characterization of Randers spaces, are also included.

  19. Affine stochastic mortality

    NARCIS (Netherlands)

    D.F. Schrager

    2006-01-01

    We propose a new model for stochastic mortality. The model is based on the literature on affine term structure models. It satisfies three important requirements for application in practice: analytical tractibility, clear interpretation of the factors and compatibility with financial option pricing m

  20. Affinity Monolith-Integrated Microchips for Protein Purification and Concentration.

    Science.gov (United States)

    Gao, Changlu; Sun, Xiuhua; Wang, Huaixin; Qiao, Wei; Hu, Bo

    2016-01-01

    Affinity chromatography is a valuable method to purify and concentrate minute amount of proteins. Monoliths with epoxy groups for affinity immobilization were prepared by direct in-situ photopolymerization of glycidyl methacrylate and ethylene glycol dimethacrylate in porogenic solvents consisting of 1-dodecanol and cyclohexanol. By integrating affinity monoliths onto a microfluidic system, targeted biomolecules can be captured and retained on affinity column, while other biomolecules having no specific interactions toward the immobilized ligands flow through the microchannel. Therefore, proteins which remain on the affinity column are purified and concentrated, and then eluted by appropriate solutions and finally, separated by microchip capillary electrophoresis. This integrated microfluidic device has been applied to the purification and separation of specific proteins (FITC-labeled human serum albumin and IgG) in a mixture.

  1. 医院分离耐碳青霉烯类药物鲍曼不动杆菌亲缘性的研究%The research on affinity of hospital separation carbapenems-resistant Acinetobacter

    Institute of Scientific and Technical Information of China (English)

    李光荣; 向成玉; 杨葵; 刘靳波

    2016-01-01

    Objective To study the protein fingerprinting of carbapenems resistant and susceptible Acinetobacter baumannii (Ab) strains ,investigate the clinical value of affinity distance in carbapenems resistant strains .Methods A total of 22 carbapenems resistant Ab strains and 18 carbapenems susceptible Ab strains were collected ,and bacterial protein fingerprinting was detected by surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS) ,differentially expressed proteins was analyzed by Biomarker Wizard 3 .1 .Cluster analysis of differential expressed proteins was conducted on SPSS 19 .0 .Results The protein expression pattern of carbapenems resistant and sensitive Ab strains had significant difference (P< 0 .05) .Cluster anal-ysis showed carbapenems resistance Ab was given priority to with type A ,followed by type B .Conclusion The results of cluster a-nalysis carbapenems resistance of Ab protein fingerprinting could determine the distance of affinity relationship of Ab .It could pro-vide a theoretical basis for the infection and clinical epidemiology of Ab .%目的:通过分析鲍曼不动杆菌(Ab)碳青霉烯类药物耐药和敏感菌株蛋白指纹图谱,了解碳青霉烯类药物耐药菌株亲缘性远近的临床应用价值。方法收集临床分离对碳青霉烯类药物耐药(22株)和敏感的 Ab(18株),利用表面增强激光解析电离飞行时间质谱技术(SELDI-TOF-MS)检测细菌蛋白质指纹图谱。采用 Biomarker Wizard 3.1软件分析碳青霉烯类药物耐药和敏感 Ab 相关差异蛋白,采用 SPSS 19.0对差异蛋白进行聚类分析,追溯其临床感染的亲缘性。结果碳青霉烯类药物耐药与敏感的 Ab 菌株间蛋白质谱的表达差异有统计学意义(P<0.05)。聚类分析结果显示碳青霉烯类药物耐药 Ab 在院内的分布以A 型为主,B 型次之。结论聚类分析碳青霉烯类抗菌药物耐药的 Ab 蛋白质谱结果

  2. Gravitation, Electromagnetism and the Cosmological Constant in Purely Affine Gravity

    Science.gov (United States)

    Popławski, Nikodem J.

    The Eddington Lagrangian in the purely affine formulation of general relativity generates the Einstein equations with the cosmological constant. The Ferraris-Kijowski purely affine Lagrangian for the electromagnetic field, which has the form of the Maxwell Lagrangian with the metric tensor replaced by the symmetrized Ricci tensor, is dynamically equivalent to the Einstein-Maxwell Lagrangian in the metric formulation. We show that the sum of the two affine Lagrangians is dynamically inequivalent to the sum of the analogous Lagrangians in the metric-affine/metric formulation. We also show that such a construction is valid only for weak electromagnetic fields. Therefore the purely affine formulation that combines gravitation, electromagnetism and the cosmological constant cannot be a simple sum of terms corresponding to separate fields. Consequently, this formulation of electromagnetism seems to be unphysical, unlike the purely metric and metric-affine pictures, unless the electromagnetic field couples to the cosmological constant.

  3. Characterization of the binding strengths between boronic acids and cis-diol-containing biomolecules by affinity capillary electrophoresis.

    Science.gov (United States)

    Lü, Chenchen; Liu, Zhen

    2015-01-01

    The affinity of boronic acids toward cis-diol-containing biomolecules has found wide applications in many fields, such as sensing, separation, drug delivery, and functional materials. A sound understanding of the binding interactions will greatly facilitate exquisite applications of this chemistry. Traditional techniques are associated with some apparent drawbacks, so they are only applicable to a limited range of boronic acids and cis-diol-containing biomolecules. This chapter describes an affinity capillary electrophoresis (ACE) method for the characterization of the binding strengths between boronic acids and cis-diol-containing biomolecules. As compared with existing approaches, such as (11)B NMR, the ACE method exhibits several significant advantages: (1) possibility of simultaneous study of multiple interactions, (2) low requirement on the purity of the binding species, (3) widely applicable to almost all types of cis-diol-containing compounds and boronic acids, and (4) high accuracy and precision.

  4. Affine and degenerate affine BMW algebras: The center

    CERN Document Server

    Daugherty, Zajj; Virk, Rahbar

    2011-01-01

    The degenerate affine and affine BMW algebras arise naturally in the context of Schur-Weyl duality for orthogonal and symplectic Lie algebras and quantum groups, respectively. Cyclotomic BMW algebras, affine Hecke algebras, cyclotomic Hecke algebras, and their degenerate versions are quotients. In this paper the theory is unified by treating the orthogonal and symplectic cases simultaneously; we make an exact parallel between the degenerate affine and affine cases via a new algebra which takes the role of the affine braid group for the degenerate setting. A main result of this paper is an identification of the centers of the affine and degenerate affine BMW algebras in terms of rings of symmetric functions which satisfy a "cancellation property" or "wheel condition" (in the degenerate case, a reformulation of a result of Nazarov). Miraculously, these same rings also arise in Schubert calculus, as the cohomology and K-theory of isotropic Grassmanians and symplectic loop Grassmanians. We also establish new inte...

  5. Hierarchical Affinity Propagation

    CERN Document Server

    Givoni, Inmar; Frey, Brendan J

    2012-01-01

    Affinity propagation is an exemplar-based clustering algorithm that finds a set of data-points that best exemplify the data, and associates each datapoint with one exemplar. We extend affinity propagation in a principled way to solve the hierarchical clustering problem, which arises in a variety of domains including biology, sensor networks and decision making in operational research. We derive an inference algorithm that operates by propagating information up and down the hierarchy, and is efficient despite the high-order potentials required for the graphical model formulation. We demonstrate that our method outperforms greedy techniques that cluster one layer at a time. We show that on an artificial dataset designed to mimic the HIV-strain mutation dynamics, our method outperforms related methods. For real HIV sequences, where the ground truth is not available, we show our method achieves better results, in terms of the underlying objective function, and show the results correspond meaningfully to geographi...

  6. Affinity driven social networks

    Science.gov (United States)

    Ruyú, B.; Kuperman, M. N.

    2007-04-01

    In this work we present a model for evolving networks, where the driven force is related to the social affinity between individuals of a population. In the model, a set of individuals initially arranged on a regular ordered network and thus linked with their closest neighbors are allowed to rearrange their connections according to a dynamics closely related to that of the stable marriage problem. We show that the behavior of some topological properties of the resulting networks follows a non trivial pattern.

  7. Purely affine Gravity

    CERN Document Server

    Skirzewski, Aureliano

    2014-01-01

    We develop a topological theory of gravity with torsion where metric has a dynamical rather than a kinematical origin. This approach towards gravity resembles pre-geometrical approaches in which a fundamental metric does not exist, but the affine connection gives place to a local inertial structure. Such feature reminds us of Mach's principle, that assumes the inertial forces should have dynamical origin. Additionally, a Newtonian gravitational force is obtained in the non-relativistic limit of the theory.

  8. On the Affine Isoperimetric Inequalities

    Indian Academy of Sciences (India)

    Wuyang Yu; Gangsong Leng

    2011-11-01

    We obtain an isoperimetric inequality which estimate the affine invariant -surface area measure on convex bodies. We also establish the reverse version of -Petty projection inequality and an affine isoperimetric inequality of $_{-p}K$.

  9. Affine morphisms at zero level

    CERN Document Server

    Das, Paramita; Gupta, Ved Prakash

    2010-01-01

    Given a finite index subfactor, we show that the {\\em affine morphisms at zero level} in the affine category over the planar algebra associated to the subfactor is isomorphic to the fusion algebra of the subfactor as a *-algebra.

  10. Microphase Separation and Gelation of Methylcellulose in the Presence of Gallic Acid and NaCl as an In Situ Gel-Forming Drug Delivery System.

    Science.gov (United States)

    Sangfai, Tanatchaporn; Tantishaiyakul, Vimon; Hirun, Namon; Li, Lin

    2016-05-11

    Novel hydrogels of methylcellulose (MC) with gallic acid (GA) and NaCl were developed for an in situ gel-forming delivery system. Plain MC and GA/NaCl/MC were characterized using micro-differential scanning calorimetry (micro-DSC), rheological and turbidity methods. The gelation temperatures of MC were reduced to body temperature with adding GA/NaCl. GA and NaCl caused slightly different effects on the gelation/degelation temperatures during heating/cooling, respectively, based on the different sensitivities of these three techniques. The gelation mechanism was investigated by UV spectrophotometry, and the hydrophobic interaction between the aromatic ring of GA and MC was verified. The NaCl/MC hydrogel had smaller micropores than GA/MC and MC, indicating a greater cross-linked density. Doxycycline (DX) was loaded into the systems and demonstrated a synergistic effect of DX/GA. Both GA and DX exhibited a sustained release. The hydrogel of GA/4NaCl/MC could be potentially used for the in situ delivery of DX for deep wound healing.

  11. Probing the interactions between boronic acids and cis-diol-containing biomolecules by affinity capillary electrophoresis.

    Science.gov (United States)

    Lü, Chenchen; Li, Hengye; Wang, Heye; Liu, Zhen

    2013-02-19

    The affinity of boronic acids to cis-diol-containing biomolecules has found wide applications in many fields, such as sensing, separation, drug delivery, and functional materials. A sound understanding of the binding interactions will greatly facilitate exquisite applications of this chemistry. Although a few analytical tools have been available for the characterization of the interactions, these techniques are associated with some apparent drawbacks, so they are only applicable to a limited range of boronic acids and cis-diol-containing biomolecules. Therefore, a widely applicable method is still greatly needed. In this work, an affinity capillary electrophoresis (ACE) method was established and validated to probe the interactions between boronic acids and cis-diol-containing biomolecules. The method was proven to be applicable to almost all types of cis-diol-containing biomolecules and boronic acids. Based on this method, a quantitative, comparative study on the interactions between 14 boronic acids that have important potentials for application with 5 typical monosaccharides of biological importance was carried out. The findings provided new insights into boronate affinity interactions, particularly the relationship between the binding strength with the molecular structures of the binding species. Besides, effects of pH and temperature on the binding strength were also investigated. This method exhibited several significant advantages, including (1) possibility of simultaneous study of multiple interactions, (2) low requirement on the purity of the binding species, (3) wide applicability, and (4) high accuracy and precision.

  12. Affine and quasi-affine frames for rational dilations

    DEFF Research Database (Denmark)

    Bownik, Marcin; Lemvig, Jakob

    2011-01-01

    , the corresponding family of quasi-affine systems are frames with uniform frame bounds. We also prove a similar equivalence result between pairs of dual affine frames and dual quasi-affine frames. Finally, we uncover some fundamental differences between the integer and rational settings by exhibiting an example......In this paper we extend the investigation of quasi-affine systems, which were originally introduced by Ron and Shen [J. Funct. Anal. 148 (1997), 408-447] for integer, expansive dilations, to the class of rational, expansive dilations. We show that an affine system is a frame if, and only if...

  13. Affine Patches on Positroid Varieties and Affine Pipe Dreams (Thesis)

    CERN Document Server

    Snider, Michelle

    2010-01-01

    The objects of interest in this thesis are positroid varieties in the Grassmannian, which are indexed by juggling patterns. In particular, we study affine patches on these positroid varieties. Our main result corresponds these affine patches to Kazhdan-Lusztig varieties in the affine Grassmannian. We develop a new term order and study how these spaces are related to subword complexes and Stanley-Reisner ideals. We define an extension of pipe dreams to the affine case and conclude by showing how our affine pipe dreams are generalizations of Cauchon and Le diagrams.

  14. Construction of a three-dimensional bionic nerve conduit containing two neurotrophic factors with separate delivery systems for the repair of sciatic nerve defects

    Institute of Scientific and Technical Information of China (English)

    Zhiyue Li; Qun Zhao; Ran Bi; Yong Zhuang; Siyin Feng

    2011-01-01

    Previous studies of nerve conduits have investigated numerous properties, such as conduit luminal structure and neurotrophic factor incorporation, for the regeneration of nerve defects. The present study used a poly(lactic-co-glycolic acid) (PLGA) copolymer to construct a three-dimensional (3D) bionic nerve conduit, with two channels and multiple microtubule lumens, and incorporating two neurotrophic factors, each with their own delivery system, as a novel environment for peripheral nerve regeneration. The efficacy of this conduit in repairing a 1.5 cm sciatic nerve defect was compared with PLGA-alone and PLGA-microfilament conduits, and autologous nerve transplantation. Results showed that compared with the other groups, the 3D bionic nerve conduit had the fastest nerve conduction velocity, largest electromyogram amplitude, and shortest electromyogram latency. In addition, the nerve fiber density, myelin sheath thickness and axon diameter were significantly increased, and the recovery rate of the triceps surae muscle wet weight was lowest. These findings suggest that 3D bionic nerve conduits can provide a suitable microenvironment for peripheral nerve regeneration to efficiently repair sciatic nerve defects.

  15. Affinity Purification of Insulin by Peptide-Ligand Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The affinity heptapeptide (HWWWPAS) for insulin, selected from phage display library,was coupled to EAH Sepharose 4B gel and packed to a 1-mL column. The column was used for the affinity purification of insulin from protein mixture and commercial insulin preparation. It was observed that the minor impurity in the commercial insulin was removed by the affinity chromatography. Nearly 40 mg of insulin could be purified with the 1-mL affinity column. The results revealed the high specificity and capacity of the affinity column for insulin purification. Moreover, based on the analysis of the amino acids in the peptide sequence, shorter peptides were designed and synthesized for insulin chromatography. As a result, HWWPS was found to be a good alternative to HWWWPAS, while the other two peptides with three or four amino acids showed weak affinity for insulin. The results indicated that the peptide sequence of HWWWPAS was quite conservative for specific binding of insulin.

  16. Jacobi Structures on Affine Bundles

    Institute of Scientific and Technical Information of China (English)

    J. GRABOWSKI; D. IGLESIAS; J. C. MARRERO; E. PADR(O)N; P. URBA(N)SKI

    2007-01-01

    We study affine Jacobi structures (brackets) on an affine bundle π: A→M, i.e. Jacobi brackets that close on affine functions. We prove that if the rank of A is non-zero, there is a one-to- one correspondence between affine Jacobi structures on A and Lie algebroid structures on the vector bundle A+=∪p∈M Aff(Ap, R) of affine functionals. In the case rank A = 0, it is shown that there is a one-to-one correspondence between affins Jacobi structures on A and local Lie algebras on A+. Some examples and applications, also for the linear case, are discussed. For a special type of affine Jacobi structures which are canonically exhibited (strongly-affine or affine-homogeneous Jacobi structures) over a real vector space of finite dimension, we describe the leaves of its characteristic foliation as the orbits of an affine representation. These afline Jacobi structures can be viewed as an analog of the Kostant-Arnold-LiouviUe linear Poisson structure on the dual space of a real finite-dimensional Lie algebra.

  17. Kernel Affine Projection Algorithms

    Directory of Open Access Journals (Sweden)

    José C. Príncipe

    2008-05-01

    Full Text Available The combination of the famed kernel trick and affine projection algorithms (APAs yields powerful nonlinear extensions, named collectively here, KAPA. This paper is a follow-up study of the recently introduced kernel least-mean-square algorithm (KLMS. KAPA inherits the simplicity and online nature of KLMS while reducing its gradient noise, boosting performance. More interestingly, it provides a unifying model for several neural network techniques, including kernel least-mean-square algorithms, kernel adaline, sliding-window kernel recursive-least squares (KRLS, and regularization networks. Therefore, many insights can be gained into the basic relations among them and the tradeoff between computation complexity and performance. Several simulations illustrate its wide applicability.

  18. Kernel Affine Projection Algorithms

    Science.gov (United States)

    Liu, Weifeng; Príncipe, José C.

    2008-12-01

    The combination of the famed kernel trick and affine projection algorithms (APAs) yields powerful nonlinear extensions, named collectively here, KAPA. This paper is a follow-up study of the recently introduced kernel least-mean-square algorithm (KLMS). KAPA inherits the simplicity and online nature of KLMS while reducing its gradient noise, boosting performance. More interestingly, it provides a unifying model for several neural network techniques, including kernel least-mean-square algorithms, kernel adaline, sliding-window kernel recursive-least squares (KRLS), and regularization networks. Therefore, many insights can be gained into the basic relations among them and the tradeoff between computation complexity and performance. Several simulations illustrate its wide applicability.

  19. 短途配送中车辆配装货物的隔票问题探讨%Discussion on the Separation Problem of Loading Goods in Short Distance Delivery by Vehicles

    Institute of Scientific and Technical Information of China (English)

    李杨

    2015-01-01

    For a long time,in order to improve the distribution efficiency,the logistical industry is very concerned about the distribution route optimization.But the reality is,the real travel time which can be compressed is very limited,and the proportion in the process of the total distribution is not high.As a matter of fact,sort-out,unloading and handover sector,especially the mixed-up stowage phenomenon for improper separation are the true causes which influence the efficiency of the distribution.This paper makes analysis on the distribution process of mixed-up stowage and improper separation,with the help of separate-lots technology and operating procedures on marine shipping,discusses on separate-lots technology and principles of loading goods in short distance delivery by vehicles,puts forward the corresponding solutions.%长期以来,物流行业非常关注配送线路优化,借以提升配送效率。但是现实情况是真正的行驶时间可压缩空间很小,而且在总的配送过程中比例不大。真正影响配送效率的是理货卸车交接环节,特别是因隔票不清导致的混票现象。文中对配送过程的混票和隔票不清的过程进行分析,借助海运中隔票技术和操作规程,对短途配送中车辆配装的隔票技术和原则进行讨论,提出对应的解决对策。

  20. Scaling analysis of affinity propagation.

    Science.gov (United States)

    Furtlehner, Cyril; Sebag, Michèle; Zhang, Xiangliang

    2010-06-01

    We analyze and exploit some scaling properties of the affinity propagation (AP) clustering algorithm proposed by Frey and Dueck [Science 315, 972 (2007)]. Following a divide and conquer strategy we setup an exact renormalization-based approach to address the question of clustering consistency, in particular, how many cluster are present in a given data set. We first observe that the divide and conquer strategy, used on a large data set hierarchically reduces the complexity O(N2) to O(N((h+2)/(h+1))) , for a data set of size N and a depth h of the hierarchical strategy. For a data set embedded in a d -dimensional space, we show that this is obtained without notably damaging the precision except in dimension d=2 . In fact, for d larger than 2 the relative loss in precision scales such as N((2-d)/(h+1)d). Finally, under some conditions we observe that there is a value s* of the penalty coefficient, a free parameter used to fix the number of clusters, which separates a fragmentation phase (for ss*) of the underlying hidden cluster structure. At this precise point holds a self-similarity property which can be exploited by the hierarchical strategy to actually locate its position, as a result of an exact decimation procedure. From this observation, a strategy based on AP can be defined to find out how many clusters are present in a given data set.

  1. Adjoint affine fusion and tadpoles

    Science.gov (United States)

    Urichuk, Andrew; Walton, Mark A.

    2016-06-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  2. Adjoint affine fusion and tadpoles

    CERN Document Server

    Urichuk, Andrew

    2016-01-01

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows, and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  3. Adjoint affine fusion and tadpoles

    Energy Technology Data Exchange (ETDEWEB)

    Urichuk, Andrew, E-mail: andrew.urichuk@uleth.ca [Physics and Astronomy Department, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Walton, Mark A., E-mail: walton@uleth.ca [Physics and Astronomy Department, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); International School for Advanced Studies (SISSA), via Bonomea 265, 34136 Trieste (Italy)

    2016-06-15

    We study affine fusion with the adjoint representation. For simple Lie algebras, elementary and universal formulas determine the decomposition of a tensor product of an integrable highest-weight representation with the adjoint representation. Using the (refined) affine depth rule, we prove that equally striking results apply to adjoint affine fusion. For diagonal fusion, a coefficient equals the number of nonzero Dynkin labels of the relevant affine highest weight, minus 1. A nice lattice-polytope interpretation follows and allows the straightforward calculation of the genus-1 1-point adjoint Verlinde dimension, the adjoint affine fusion tadpole. Explicit formulas, (piecewise) polynomial in the level, are written for the adjoint tadpoles of all classical Lie algebras. We show that off-diagonal adjoint affine fusion is obtained from the corresponding tensor product by simply dropping non-dominant representations.

  4. Gravitation, Electromagnetism and Cosmological Constant in Purely Affine Gravity

    Science.gov (United States)

    Popławski, Nikodem J.

    2009-03-01

    The Ferraris-Kijowski purely affine Lagrangian for the electromagnetic field, that has the form of the Maxwell Lagrangian with the metric tensor replaced by the symmetrized Ricci tensor, is dynamically equivalent to the metric Einstein-Maxwell Lagrangian, except the zero-field limit, for which the metric tensor is not well-defined. This feature indicates that, for the Ferraris-Kijowski model to be physical, there must exist a background field that depends on the Ricci tensor. The simplest possibility, supported by recent astronomical observations, is the cosmological constant, generated in the purely affine formulation of gravity by the Eddington Lagrangian. In this paper we combine the electromagnetic field and the cosmological constant in the purely affine formulation. We show that the sum of the two affine (Eddington and Ferraris-Kijowski) Lagrangians is dynamically inequivalent to the sum of the analogous ( ΛCDM and Einstein-Maxwell) Lagrangians in the metric-affine/metric formulation. We also show that such a construction is valid, like the affine Einstein-Born-Infeld formulation, only for weak electromagnetic fields, on the order of the magnetic field in outer space of the Solar System. Therefore the purely affine formulation that combines gravity, electromagnetism and cosmological constant cannot be a simple sum of affine terms corresponding separately to these fields. A quite complicated form of the affine equivalent of the metric Einstein-Maxwell- Λ Lagrangian suggests that Nature can be described by a simpler affine Lagrangian, leading to modifications of the Einstein-Maxwell- ΛCDM theory for electromagnetic fields that contribute to the spacetime curvature on the same order as the cosmological constant.

  5. Realization of Fractal Affine Transformation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper gives the definition of fractal affine transformation and presents a specific method for its realization and its cor responding mathematical equations which are essential in fractal image construction.

  6. Bounded contractions for affine buildings

    OpenAIRE

    Bestvina, Mladen; Savin, Gordan

    2017-01-01

    We consider affine buildings with refined chamber structure. For each vertex in the refined chamber structure we construct a contraction, based at the vertex, that is used to prove exactness of Schneider-Stuhler resolutions of arbitrary depth.

  7. Delivery Time Reliability Model of Logistics Network

    OpenAIRE

    Liusan Wu; Qingmei Tan; Yuehui Zhang

    2013-01-01

    Natural disasters like earthquake and flood will surely destroy the existing traffic network, usually accompanied by delivery delay or even network collapse. A logistics-network-related delivery time reliability model defined by a shortest-time entropy is proposed as a means to estimate the actual delivery time reliability. The less the entropy is, the stronger the delivery time reliability remains, and vice versa. The shortest delivery time is computed separately based on two different assum...

  8. Affinity chromatography of phosphorylated proteins.

    Science.gov (United States)

    Tchaga, Grigoriy S

    2008-01-01

    This chapter covers the use of immobilized metal ion affinity chromatography (IMAC) for enrichment of phosphorylated proteins. Some requirements for successful enrichment of these types of proteins are discussed. An experimental protocol and a set of application data are included to enable the scientist to obtain high-yield results in a very short time with pre-packed phospho-specific metal ion affinity resin (PMAC).

  9. Oriented angles in affine space

    Directory of Open Access Journals (Sweden)

    Włodzimierz Waliszewski

    2004-05-01

    Full Text Available The concept of a smooth oriented angle in an arbitrary affine space is introduced. This concept is based on a kinematics concept of a run. Also, a concept of an oriented angle in such a space is considered. Next, it is shown that the adequacy of these concepts holds if and only if the affine space, in question, is of dimension 2 or 1.

  10. Delivery presentations

    Science.gov (United States)

    ... passage will take place depends on how your baby is positioned during delivery. The best position for the baby to be ... possible, but labor will generally take longer. After delivery, the baby's face or brow will be swollen and may ...

  11. Affinity Solvents for Intensified Organics Extraction: Development Challenges and Prospects

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In most organics extraction processes, the commonly used solvents employ solely physical interactions. Therefore, for the recovery and purification of products from complex mixtures, the selectivity and/or capacity of classical solvents towards the desired solutes is usually insufficient, enforcing the need for complex and thus expensive separation schemes. Significant simplification and cost-reduction can be achieved when affinity solvents would be available that are able to recognize the solutes of interest by their molecular structure. The main development challenges to establish such affinity solvents are: Selection and incorporation of molecular recognition and complexation capabilities; Evaluation of extraction capabilities; Efficient recovery and recycling of the affinity solvents; Implementation in industrial extraction equipment. This paper presents how these development challenges are addressed at the University of Twente, going all the way from affinity solvent design and synthesis, via high throughput screening and characterization up to pilot plant evaluation. Essential in the successful development of affinity solvents are structural cooperations with molecular chemists and custom synthesis companies for their design and synthesis. The various aspects are illustrated by several examples where newly developed environmentally benign affinity solvents appeared able to create major breakthroughs. The applications addressed involve oxygenates, sugars, and pharmaceutical ingredients, such as optical isomers and biomolecules.

  12. Affinity enhancement of antibodies: how low-affinity antibodies produced early in immune responses are followed by high-affinity antibodies later and in memory B-cell responses.

    Science.gov (United States)

    Eisen, Herman N

    2014-05-01

    The antibodies produced initially in response to most antigens are high molecular weight (MW) immunoglobulins (IgM) with low affinity for the antigen, while the antibodies produced later are lower MW classes (e.g., IgG and IgA) with, on average, orders of magnitude higher affinity for that antigen. These changes, often termed affinity maturation, take place largely in small B-cell clusters (germinal center; GC) in lymphoid tissues in which proliferating antigen-stimulated B cells express the highly mutagenic cytidine deaminase that mediates immunoglobulin class-switching and sequence diversification of the immunoglobulin variable domains of antigen-binding receptors on B cells (BCR). Of the large library of BCR-mutated B cells thus rapidly generated, a small minority with affinity-enhancing mutations are selected to survive and differentiate into long-lived antibody-secreting plasma cells and memory B cells. BCRs are also endocytic receptors; they internalize and cleave BCR-bound antigen, yielding peptide-MHC complexes that are recognized by follicular helper T cells. Imperfect correlation between BCR affinity for antigen and cognate T-cell engagement may account for the increasing affinity heterogeneity that accompanies the increasing average affinity of antibodies. Conservation of mechanisms underlying mutation and selection of high-affinity antibodies over the ≈200 million years of evolution separating bird and mammal lineages points to the crucial role of antibody affinity enhancement in adaptive immunity.

  13. Organic Separation Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Renee L.; Rinehart, Donald E.; Peterson, Reid A.

    2014-09-22

    Separable organics have been defined as “those organic compounds of very limited solubility in the bulk waste and that can form a separate liquid phase or layer” (Smalley and Nguyen 2013), and result from three main solvent extraction processes: U Plant Uranium Recovery Process, B Plant Waste Fractionation Process, and Plutonium Uranium Extraction (PUREX) Process. The primary organic solvents associated with tank solids are TBP, D2EHPA, and NPH. There is concern that, while this organic material is bound to the sludge particles as it is stored in the tanks, waste feed delivery activities, specifically transfer pump and mixer pump operations, could cause the organics to form a separated layer in the tank farms feed tank. Therefore, Washington River Protection Solutions (WRPS) is experimentally evaluating the potential of organic solvents separating from the tank solids (sludge) during waste feed delivery activities, specifically the waste mixing and transfer processes. Given the Hanford Tank Waste Treatment and Immobilization Plant (WTP) waste acceptance criteria per the Waste Feed Acceptance Criteria document (24590-WTP-RPT-MGT-11-014) that there is to be “no visible layer” of separable organics in the waste feed, this would result in the batch being unacceptable to transfer to WTP. This study is of particular importance to WRPS because of these WTP requirements.

  14. Affine Contractions on the Plane

    Science.gov (United States)

    Celik, D.; Ozdemir, Y.; Ureyen, M.

    2007-01-01

    Contractions play a considerable role in the theory of fractals. However, it is not easy to find contractions which are not similitudes. In this study, it is shown by counter examples that an affine transformation of the plane carrying a given triangle onto another triangle may not be a contraction even if it contracts edges, heights or medians.…

  15. Gravity theory through affine spheres

    Science.gov (United States)

    Minguzzi, E.

    2017-08-01

    In this work it is argued that in order to improve our understanding of gravity and spacetime our most successful theory, general relativity, must be destructured. That is, some geometrical assumptions must be dropped and recovered just under suitable limits. Along this line of thought we pursue the idea that the roundness of the light cone, and hence the isotropy of the speed of light, must be relaxed and that, in fact, the shape of light cones must be regarded as a dynamical variable. Mathematically, we apply some important results from affine differential geometry to this problem, the idea being that in the transition we should preserve the identification of the spacetime continuum with a manifold endowed with a cone structure and a spacetime volume form. To that end it is suggested that the cotangent indicatrix (dispersion relation) must be described by an equation of Monge-Ampère type determining a hyperbolic affine sphere, at least whenever the matter content is negligible. Non-relativistic spacetimes fall into this description as they are recovered whenever the center of the affine sphere is at infinity. In the more general context of Lorentz-Finsler theories it is shown that the lightlike unparametrized geodesic flow is completely determined by the distribution of light cones. Moreover, the transport of lightlike momenta is well defined though there could be no notion of affine parameter. Finally, we show how the perturbed indicatrix can be obtained from the perturbed light cone.

  16. Synthesis of Glutamic Acid-based Cluster Galactosides and Their Binding Affinities with Liver Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Xiao-Ru(张晓茹); Ll,Ying-Xia(李英霞); CHU,Shi-Dong(褚世栋); DING,Ning(丁宁); Ll,Chun-Xia(李春霞); GUAN,Hua-Shi(管华诗)

    2004-01-01

    Structurally well defined di-,tri-and tetra-valent cluster galactosides were synthesized in a convenient way.Oligo-glutamic acids were assembled as scaffolds.The presence of amine groups in these three ligands is expected to couple with drugs or genes for delivery.The binding affinities of these cluster galactoses to liver cells were determined by in vitro binding studies.Among them,the tetravalent cluster galactose (19) showed the highest affinity to liver cell.It is therefore a promising targeting device for the specific delivery of drugs or genes to parenchymal liver cells.

  17. Theoretical proton affinity and fluoride affinity of nerve agent VX.

    Science.gov (United States)

    Bera, Narayan C; Maeda, Satoshi; Morokuma, Keiji; Viggiano, Al A

    2010-12-23

    Proton affinity and fluoride affinity of nerve agent VX at all of its possible sites were calculated at the RI-MP2/cc-pVTZ//B3LYP/6-31G* and RI-MP2/aug-cc-pVTZ//B3LYP/6-31+G* levels, respectively. The protonation leads to various unique structures, with H(+) attached to oxygen, nitrogen, and sulfur atoms; among which the nitrogen site possesses the highest proton affinity of -ΔE ∼ 251 kcal/mol, suggesting that this is likely to be the major product. In addition some H(2), CH(4) dissociation as well as destruction channels have been found, among which the CH(4) + [Et-O-P(═O)(Me)-S-(CH(2))(2)-N(+)(iPr)═CHMe] product and the destruction product forming Et-O-P(═O)(Me)-SMe + CH(2)═N(+)(iPr)(2) are only 9 kcal/mol less stable than the most stable N-protonated product. For fluoridization, the S-P destruction channel to give Et-O-P(═O)(Me)(F) + [S-(CH(2))(2)-N-(iPr)(2)](-) is energetically the most favorable, with a fluoride affinity of -ΔE ∼ 44 kcal. Various F(-) ion-molecule complexes are also found, with the one having F(-) interacting with two hydrogen atoms in different alkyl groups to be only 9 kcal/mol higher than the above destruction product. These results suggest VX behaves quite differently from surrogate systems.

  18. Forceps Delivery

    Science.gov (United States)

    ... in place to control the advance of your baby's head. Forceps deliveries aren't always successful. If your health care ... com. Accessed June 12, 2015. You and your baby: Prenatal care, labor and delivery, and postpartum care. Washington, D.C.: The American ...

  19. Protein purification by aminosquarylium cyanine dye-affinity chromatography.

    Science.gov (United States)

    Silva, M S; Graça, V C; Reis, L V; Santos, P F; Almeida, P; Queiroz, J A; Sousa, F

    2013-12-01

    The most selective purification method for proteins and other biomolecules is affinity chromatography. This method is based on the unique biological-based specificity of the biomolecule-ligand interaction and commonly uses biological ligands. However, these ligands may present some drawbacks, mainly because of their cost and lability. Dye-affinity chromatography overcomes the limitations of biological ligands and is widely used owing to the low cost of synthetic dyes and to their resistance to biological and chemical degradation. In this work, immobilized aminosquarylium cyanine dyes are used in order to exploit affinity interactions with standard proteins such as lysozyme, α-chymotrypsin and trypsin. These studies evaluate the affinity interactions occurring between the immobilized ligand and the different proteins, as a reflection of the sum of several molecular interactions, namely ionic, hydrophobic and van der Waals, spread throughout the structure, in a defined spatial manner. The results show the possibility of using an aminosquarylium cyanine dye bearing a N-hexyl pendant chain, with a ligand density of 1.8 × 10(-2) mmol of dye/g of chromatographic support, to isolate lysozyme, α-chymotrypsin and trypsin from a mixture. The application of a decreasing ammonium sulfate gradient resulted in the recovery of lysozyme in the flowthrough. On the other hand, α-chymotrypsin and trypsin were retained, involving different interactions with the ligand. In conclusion, this study demonstrates the potential applicability of ligands such as aminosquarylium cyanine dyes for the separation and purification of proteins by affinity chromatography.

  20. Electron affinity of chlorine dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Babcock, L.M.; Pentecost, T.; Koppenol, W.H. (Louisiana State Univ., Baton Rouge (USA))

    1989-12-14

    The flowing afterglow technique was used to determine the electron affinity of chlorine dioxide. A value of 2.37 {plus minus} 0.10 eV was found by bracketing between the electron affinities of HS* and SF{sub 4} as a lower limit and that of NO{sub 2} as an upper limit. This value is in excellent agreement with 2.32 eV predicted from a simple thermodynamic cycle involving the reduction potential of the ClO{sub 2}/ClO{sub 2}{sup {minus}} couple and a Gibbs hydration energy identical with that of SO{sub 2}{sup {sm bullet}{minus}}.

  1. The electron affinity of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, A.O.; Andersson, P.; Klason, P.; Hanstorp, D. [Department of Physics, University of Gothenburg (Sweden); Diehl, C. [Institut fur Physik, Johannes Gutenberg-Universitat, Mainz (Germany); Present Address: Max-Planck-Institut fur Kernphysik, Heidelberg (Germany); Forstner, O. [Faculty of Physics, University of Vienna, Wien (Austria)

    2010-11-15

    The electron affinity of tungsten has been measured using laser photodetachment threshold spectroscopy in a collinear geometry. The electron affinity was determined to 6583.6(6) cm{sup -1} by observing the onset of the process when W{sup -} ions in the 5d{sup 5}6s{sup 2} {sup 6}S{sub 5/2} ground state are photo-detached producing neutral W atoms in the 5d{sup 4}6s{sup 2} {sup 5}D{sub 0} ground state. The measured value is in agreement with previous measurements and improves the accuracy by almost two orders of magnitude. Further, a photodetachment signal below the ground state photodetachment threshold was found, which indicates the existence of a bound excited state in W{sup -}. (authors)

  2. Affine density in wavelet analysis

    CERN Document Server

    Kutyniok, Gitta

    2007-01-01

    In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.

  3. Affinity Purification of Protein Complexes Using TAP Tags

    Science.gov (United States)

    Gerace, Erica; Moazed, Danesh

    2016-01-01

    This protocol is used for the isolation and analysis of protein complexes using the tandem affinity purification (TAP) tag system. The protocol describes the purification of a protein fused to a TAP tag comprised of two protein A domains and the calmodulin binding peptide separated by a TEV cleavage site. This is a powerful technique for rapid purification of protein complexes and the analysis of their stoichiometric composition, posttranslational modifications, structure, and functional activities. PMID:26096502

  4. Affine connections on involutive G-structures

    OpenAIRE

    Merkulov, Sergey A.

    1995-01-01

    This paper is a review of the twistor theory of irreducible G-structures and affine connections. Long ago, Berger presented a very restricted list of possible irreducibly acting holonomies of torsion-free affine connections. His list was complete in the part of metric connections, while the situation with holonomies of non-metric torsion-free affine connections was and remains rather unclear. One of the results discussed in this review asserts that any torsion-free holomorphic affine connecti...

  5. The Quasi—affine Maps and Fractals

    Institute of Scientific and Technical Information of China (English)

    LunhaiLONG; GangCHEN

    1997-01-01

    In this paper,we discuss the discretization of the affine maps in R2,that is ,we consider a class of maps in Z2,which are induced by affine maps and called the quasi-affine maps.We investigate the properties and the dynamical behaviour of such maps,and give a sort of construction of complicated fractals by using quasi-affine maps.

  6. Manifolds with integrable affine shape operator

    Directory of Open Access Journals (Sweden)

    Daniel A. Joaquín

    2005-05-01

    Full Text Available This work establishes the conditions for the existence of vector fields with the property that theirs covariant derivative, with respect to the affine normal connection, be the affine shape operatorS in hypersurfaces. Some results are obtained from this property and, in particular, for some kind of affine decomposable hypersurfaces we explicitely get the actual vector fields.

  7. Separation Logic

    DEFF Research Database (Denmark)

    Reynolds, John C.

    2002-01-01

    expressions) for accessing and modifying shared structures, and for explicit allocation and deallocation of storage. Assertions are extended by introducing a "separating conjunction" that asserts that its sub-formulas hold for disjoint parts of the heap, and a closely related "separating implication". Coupled......, dynamically allocated arrays, and recursive procedures. We will also discuss promising future directions....

  8. Topological conjugacy classes of affine maps

    OpenAIRE

    2008-01-01

    A map $f: \\ff^n \\to \\ff^n$ over a field $\\ff$ is called affine if it is of the form $f(x)=Ax+b$, where the matrix $A \\in \\ff^{n\\times n}$ is called the linear part of affine map and $b \\in \\ff^n$. The affine maps over $\\ff=\\rr$ or $\\cc$ are investigated. We prove that affine maps having fixed points are topologically conjugate if and only if their linear parts are topologically conjugate. If affine maps have no fixed points and $n=1$ or 2, then they are topologically conjugate if and only if ...

  9. Using Affinity Diagrams to Evaluate Interactive Prototypes

    DEFF Research Database (Denmark)

    Lucero, Andrés

    2015-01-01

    Affinity diagramming is a technique used to externalize, make sense of, and organize large amounts of unstructured, far-ranging, and seemingly dissimilar qualitative data. HCI and interaction design practitioners have adopted and used affinity diagrams for different purposes. This paper discusses...... our particular use of affinity diagramming in prototype evaluations. We reflect on a decade’s experience using affinity diagramming across a number of projects, both in industry and academia. Our affinity diagramming process in interaction design has been tailored and consists of four stages: creating...

  10. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  11. Extension of the selection of protein chromatography and the rate model to affinity chromatography.

    Science.gov (United States)

    Sandoval, G; Shene, C; Andrews, B A; Asenjo, J A

    2010-01-01

    The rational selection of optimal protein purification sequences, as well as mathematical models that simulate and allow optimization of chromatographic protein purification processes have been developed for purification procedures such as ion-exchange, hydrophobic interaction and gel filtration chromatography. This paper investigates the extension of such analysis to affinity chromatography both in the selection of chromatographic processes and in the use of the rate model for mathematical modelling and simulation. Two affinity systems were used: Blue Sepharose and Protein A. The extension of the theory developed previously for ion-exchange and HIC chromatography to affinity separations is analyzed in this paper. For the selection of operations two algorithms are used. In the first, the value of η, which corresponds to the efficiency (resolution) of the actual chromatography and, Σ, which determines the amount of a particular contaminant eliminated after each separation step, which determines the purity, have to be determined. It was found that the value of both these parameters is not generic for affinity separations but will depend on the type of affinity system used and will have to be determined on a case by case basis. With Blue Sepharose a salt gradient was used and with Protein A, a pH gradient. Parameters were determined with individual proteins and simulations of the protein mixtures were done. This approach allows investigation of chromatographic protein purification in a holistic manner that includes ion-exchange, HIC, gel filtration and affinity separations for the first time.

  12. Several Affinity Tags Commonly Used in Chromatographic Purification

    Directory of Open Access Journals (Sweden)

    Xinyu Zhao

    2013-01-01

    Full Text Available Affinity tags have become powerful tools from basic biological research to structural and functional proteomics. They were widely used to facilitate the purification and detection of proteins of interest, as well as the separation of protein complexes. Here, we mainly discuss the benefits and drawbacks of several affinity or epitope tags frequently used, including hexahistidine tag, FLAG tag, Strep II tag, streptavidin-binding peptide (SBP tag, calmodulin-binding peptide (CBP, glutathione S-transferase (GST, maltose-binding protein (MBP, S-tag, HA tag, and c-Myc tag. In some cases, a large-size affinity tag, such as GST or MBP, can significantly impact on the structure and biological activity of the fusion partner protein. So it is usually necessary to excise the tag by protease. The most commonly used endopeptidases are enterokinase, factor Xa, thrombin, tobacco etch virus, and human rhinovirus 3C protease. The proteolysis features of these proteases are described in order to provide a general guidance on the proteolytic removal of the affinity tags.

  13. The electron affinity of phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, P [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Lindahl, A O [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Alfredsson, C [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Rogstroem, L [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden); Diehl, C [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz, D-55099 Mainz (Germany); Pegg, D J [Department of Physics, University of Tennessee, Knoxville, TN 37996 (United States); Hanstorp, D [Department of Physics, Goeteborg University, SE-412 96, Goeteborg (Sweden)

    2007-10-28

    We have measured the energies of all three fine structure components in the {sup 3}P{sub J} ground state of the negative ion of phosphorus using laser photodetachment threshold spectroscopy. The experiment yielded an electron affinity of 746.68(6) meV. The {delta}J = 2-0, 2-1 and 1-0 fine structure splittings were determined to be 32.73(7) meV, 22.48(7) meV and 10.25(3) meV, respectively. In the experiment, a mass selected beam of P{sup -} ions was merged with the output from a pulsed infrared optical parametric oscillator. The residual atoms produced in the photodetachment process were detected and used as a monitor of the photon-energy dependence of the relative cross section. The Wigner law was fitted to each of the three observed onsets of production of neutrals in order to extract the threshold energies.

  14. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    OpenAIRE

    Ikegami Toru; Yanagishita Hiroshi; Nakane Takashi; Im Jae Hong; Kitamoto Dai

    2001-01-01

    Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand...

  15. An Affine Combination of Adaptive Filters for Channels with Different Sparsity Levels

    Directory of Open Access Journals (Sweden)

    M. Butsenko

    2016-06-01

    Full Text Available In this paper we present an affine combination strategy for two adaptive filters. One filter is designed to handle sparse impulse responses and the other one performs better if impulse response is dispersive. Filter outputs are combined using an adaptive mixing parameter and the resulting output shows a better performance than each of the combining filters separately. We also demonstrate that affine combination results in faster convergence than a convex combination of two adaptive filters.

  16. 硼酸作为亲和色谱配基的研究进展%Boronic Acids as Ligands for Affinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    刘晓川

    2006-01-01

    A review on the principles and applications of boronic acids as affinity ligands for the chromatographic separation of carbohydrates, nucleic acid components, glycoproteins, and other small biomolecules.The mechanisms of interactions between boronate ligands and analytes are described. Various boronate ligands and supports are discussed. Examples of the use of boronate affinity chromatography for separation of each class of analytes are presented.

  17. Multipole solutions in metric-affine gravity

    CERN Document Server

    Socorro, J; Macías, A; Mielke, E W; Socorro, José; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.

    1998-01-01

    Above Planck energies, the spacetime might become non--Riemannian, as it is known fron string theory and inflation. Then geometries arise in which nonmetricity and torsion appear as field strengths, side by side with curvature. By gauging the affine group, a metric affine gauge theory emerges as dynamical framework. Here, by using the harmonic map ansatz, a new class of multipole like solutions in the metric affine gravity theory (MAG) is obtained.

  18. Ordinary differential equations in affine geometry

    Directory of Open Access Journals (Sweden)

    Salvador Gigena

    1996-05-01

    Full Text Available The method of qualitative analysis is used, as applied to a class of fourth order, nonlinear ordinary differential equations, in order to classify, both locally and globally, two classes of hypersurfaces of decomposable type in affine geometry: those with constant unimodular affine mean curvature L , and those with constant Riemannian scalar curvature R. This allows to provide a large number of new examples of hypersurfaces in affine geometry.

  19. Ordinary differential equations in affine geometry

    OpenAIRE

    Salvador Gigena

    1996-01-01

    The method of qualitative analysis is used, as applied to a class of fourth order, nonlinear ordinary differential equations, in order to classify, both locally and globally, two classes of hypersurfaces of decomposable type in affine geometry: those with constant unimodular affine mean curvature L , and those with constant Riemannian scalar curvature R. This allows to provide a large number of new examples of hypersurfaces in affine geometry.

  20. Craniomandibular morphology and phylogenetic affinities of panthera atrox

    DEFF Research Database (Denmark)

    Christiansen, Per; Harris, J.M.

    2009-01-01

    The great North American Pleistocene pantherine felid Panthera atrox has had a turbulent phylogenetic history, and has been claimed to show affinities to both the jaguar and the tiger; currently, it is most often regarded as a subspecies of the extant lion. The cranial, mandibular, and dental...... morphology of Panthera atrox was compared with those of extant lions, jaguars, and tigers using bivariate, multivariate, and shape analyses. Results indicate that the skull of Panthera atrox shows lion affinities, but also deviates from lions in numerous aspects. Mandibular morphology is more similar...... to jaguars and tigers and, as with cranial morphology, the mandible shows a number of traits not present among extant pantherines. Multivariate analyses grouped Panthera atrox separately from other pantherines. Panthera atrox was no lion, and cannot be assigned to any of the extant pantherines...

  1. Polysulfone affinity membranes for the treatment of amino acid mixtures.

    Science.gov (United States)

    Rodemann, K; Staude, E

    1995-06-20

    Affinity membranes for the treatment of solutions containing amino acids were obtained via lithiating polysulfone that was subsequently converted with glycidylether. From this polymer asymmetric ultrafiltration membranes were cast. The membranes were reacted with iminodiacetic acid yielding membranes fitted out with bidentate chelates. The same reaction path was applied to commercially available symmetric microfiltration membranes. The chelate-bearing membranes were complexed with Cu, Ni, and Zn ions. For the experiments with amino acids only the Cu-complexed membranes were used. The complexation constants for histidine and tryptophan for six different membranes were determined. Because of the affinity of these two amino acids for the complexed Cu ions, they could easily be separated from solutions containing amino acids such as alanine, glycine, and valine. Also, concentrating very dilute amino acid solutions was carried out successfully.

  2. Affine connections, midpoint formation, and point reflection

    DEFF Research Database (Denmark)

    Kock, Anders

    2011-01-01

    We describe some differential-geometric structures in combinatorial terms: namely affine connections and their torsion and curvature, and we show that torsion free affine connections may equivalently be presented in terms of some simpler combinatorial structure: midpoint formation, and point refl...... reflection (geodesic symmetry). The method employed is that of synthetic differential geometry, which is briefly explained.......We describe some differential-geometric structures in combinatorial terms: namely affine connections and their torsion and curvature, and we show that torsion free affine connections may equivalently be presented in terms of some simpler combinatorial structure: midpoint formation, and point...

  3. A Novel Vertex Affinity for Community Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    We propose a novel vertex affinity measure in this paper. The new vertex affinity quantifies the proximity between two vertices in terms of their clustering strength and is ideal for such graph analytics applications as community detection. We also developed a framework that combines simple graph searches and resistance circuit formulas to compute the vertex affinity efficiently. We study the properties of the new affinity measure empirically in comparison to those of other popular vertex proximity metrics. Our results show that the existing metrics are ill-suited for community detection due to their lack of fundamental properties that are essential for correctly capturing inter- and intra-cluster vertex proximity.

  4. Measurement of the electron affinity of lanthanum

    Energy Technology Data Exchange (ETDEWEB)

    Covington, A.M.; Calabrese, D.; Thompson, J.S. [Department of Physics and Chemical Physics Programme, University of Nevada, Reno, NV 89557-0058 (United States); Kvale, T.J. [Department of Physics and Astronomy, University of Toledo, OH 43606-3390 (United States)

    1998-10-28

    The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first electron affinity measurement for lanthanum and one of the first measurements of an electron affinity of a rare-earth series element. The electron affinity of lanthanum was measured to be 0.47{+-}0.02 eV. At least one bound excited state of La{sup -} was also observed in the photoelectron spectra, and the binding energy relative to the ground state of lanthanum was measured as 0.17{+-}0.02 eV. The present experimental measurements are compared to a recent calculation. (author). Letter-to-the-editor.

  5. Structure of classical affine and classical affine fractional W-algebras

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)

    2015-01-15

    We introduce a classical BRST complex (See Definition 3.2.) and show that one can construct a classical affine W-algebra via the complex. This definition clarifies that classical affine W-algebras can be considered as quasi-classical limits of quantum affine W-algebras. We also give a definition of a classical affine fractional W-algebra as a Poisson vertex algebra. As in the classical affine case, a classical affine fractional W-algebra has two compatible λ-brackets and is isomorphic to an algebra of differential polynomials as a differential algebra. When a classical affine fractional W-algebra is associated to a minimal nilpotent, we describe explicit forms of free generators and compute λ-brackets between them. Provided some assumptions on a classical affine fractional W-algebra, we find an infinite sequence of integrable systems related to the algebra, using the generalized Drinfel’d and Sokolov reduction.

  6. GPS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  7. HRS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  8. Engineering bioceramic microstructure for customized drug delivery

    Science.gov (United States)

    Pacheco Gomez, Hernando Jose

    One of the most efficient approaches to treat cancer and infection is to use biomaterials as a drug delivery system (DDS). The goal is for the material to provide a sustained release of therapeutic drug dose locally to target the ill tissue without affecting other organs. Silica Calcium Phosphate nano composite (SCPC) is a drug delivery platform that successfully demonstrated the ability to bind and release several therapeutics including antibiotics, anticancer drugs, and growth factors. The aim of the present work is to analyze the role of SCPC microstructure on drug binding and release kinetics. The main crystalline phases of SCPC are alpha-cristobalite (SiO2, Cris) and beta-rhenanite (NaCaPO4, Rhe); therefore, these two phases were prepared and characterized separately. Structural and compositional features of Cris, Rhe and SCPC bioceramics demonstrated a significant influence on the loading capacity and release kinetics profile of Vancomycin (Vanc) and Cisplatin (Cis). Fourier Transform Infrared (FTIR) spectroscopy analyses demonstrated that the P-O functional group in Rhe and SCPC has high affinity to the (C=O and N-H) of Vanc and (N-H and O-H) of Cis. By contrast, a weak chemical interaction between the Si-O functional group in Cris and SCPC and the two drugs was observed. Vanc loading per unit surface area increased in the order 8.00 microg Vanc/m2 for Rhe > 4.49 microg Vanc /m2 for SCPC>3.01 microg Vanc /m2 for Cris (pAnimals were treated by either systemic cisplatin injection (sCis), or with SCPC-Cis hybrid placed adjacent (ADJ) to, or within (IT), the tumor. Five days after implantation 50-55% of the total cisplatin loaded was released from the SCPC-Cis hybrids resulting in an approximately 50% decrease in tumor volume compared to sCis treatment. Severe side effects were observed in animals treated with sCis including rapid weight loss and decreased liver and kidney function, effects not observed in SCPC-Cis treated animals. Analysis of cisplatin

  9. Delivery Time Reliability Model of Logistics Network

    Directory of Open Access Journals (Sweden)

    Liusan Wu

    2013-01-01

    Full Text Available Natural disasters like earthquake and flood will surely destroy the existing traffic network, usually accompanied by delivery delay or even network collapse. A logistics-network-related delivery time reliability model defined by a shortest-time entropy is proposed as a means to estimate the actual delivery time reliability. The less the entropy is, the stronger the delivery time reliability remains, and vice versa. The shortest delivery time is computed separately based on two different assumptions. If a path is concerned without capacity restriction, the shortest delivery time is positively related to the length of the shortest path, and if a path is concerned with capacity restriction, a minimax programming model is built to figure up the shortest delivery time. Finally, an example is utilized to confirm the validity and practicality of the proposed approach.

  10. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...

  11. Dyes with high affinity for polylactide

    Institute of Scientific and Technical Information of China (English)

    Liang He; Shu Fen Zhang; Bing Tao Tang; Li Li Wang; Jin Zong Yang

    2007-01-01

    Attempts were made to develop dyes with high affinity for polylactide as an alternative to the existent commercial disperse dyes.The dyes synthesized according to the affinity concept of dye to polylactide exhibited excellent dyeing properties on polylactide compared with the commercial disperse dyes.

  12. On affine non-negative matrix factorization

    DEFF Research Database (Denmark)

    Laurberg, Hans; Hansen, Lars Kai

    2007-01-01

    We generalize the non-negative matrix factorization (NMF) generative model to incorporate an explicit offset. Multiplicative estimation algorithms are provided for the resulting sparse affine NMF model. We show that the affine model has improved uniqueness properties and leads to more accurate...

  13. Affine processes on positive semidefinite matrices

    CERN Document Server

    Cuchiero, Christa; Mayerhofer, Eberhard; Teichmann, Josef

    2009-01-01

    This paper provides the mathematical foundation for stochastically continuous affine processes on the cone of positive semidefinite symmetric matrices. These matrix-valued affine processes have arisen from a large and growing range of useful applications in finance, including multi-asset option pricing with stochastic volatility and correlation structures, and fixed-income models with stochastically correlated risk factors and default intensities.

  14. Affinity ultrafiltration of DNA topoisomerases-targeted compounds determined with HPLC/ESI-MS for drug candidate screening

    Institute of Scientific and Technical Information of China (English)

    张虹; 潘远江

    2004-01-01

    A method of screening assay is demonstrated. The approach is based on the affinity ofantitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concentration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detection (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities.

  15. Affinity ultrafiltration of DNA topoisomerases-targeted compounds determined with HPLC/ESI-MS for drug candidate screening

    Institute of Scientific and Technical Information of China (English)

    张虹; 潘远江

    2004-01-01

    A method of screening assay is demonstrated. The approach is based on the affinity of antitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concen-tration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detec-tion (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities.

  16. Improving image segmentation by learning region affinities

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

    2010-11-03

    We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

  17. Reflectable bases for affine reflection systems

    CERN Document Server

    Azam, Saeid; Yousofzadeh, Malihe

    2011-01-01

    The notion of a "root base" together with its geometry plays a crucial role in the theory of finite and affine Lie theory. However, it is known that such a notion does not exist for the recent generalizations of finite and affine root systems such as extended affine root systems and affine reflection systems. As an alternative, we introduce the notion of a "reflectable base", a minimal subset $\\Pi$ of roots such that the non-isotropic part of the root system can be recovered by reflecting roots of $\\Pi$ relative to the hyperplanes determined by $\\Pi$. We give a full characterization of reflectable bases for tame irreducible affine reflection systems of reduced types, excluding types $E_{6,7,8}$. As a byproduct of our results, we show that if the root system under consideration is locally finite then any reflectable base is an integral base.

  18. Non-Zenoness of piecewise affine dynamical systems and affine complementarity systems with inputs

    Institute of Scientific and Technical Information of China (English)

    Le Quang THUAN

    2014-01-01

    In the context of continuous piecewise affine dynamical systems and affine complementarity systems with inputs, we study the existence of Zeno behavior, i.e., infinite number of mode transitions in a finite-length time interval, in this paper. The main result reveals that continuous piecewise affine dynamical systems with piecewise real-analytic inputs do not exhibit Zeno behavior. Applied the achieved result to affine complementarity systems with inputs, we also obtained a similar conclusion. A direct benefit of the main result is that one can apply smooth ordinary differential equations theory in a local manner for the analysis of continuous piecewise affine dynamical systems with inputs.

  19. Measurement of the Electron Affinities of Indium and Thallium

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J. S.; Carpenter, D. L.; Covington, A. M.; Williams, W. W.; Kvale, T. J.; Seely, D. G.

    1999-03-20

    The electron affinities of indium and thallium were measured in separate experiments using the laser-photodetachment electron spectroscopy technique. The measurements were performed at the University of Nevada, Reno. Negative ion beams of both indium and thallium were extracted from a cesium-sputter negative ion source, and mass analyzed using a 90{sup o} bending magnet. The negative ion beam of interest was then crossed at 90{sup o} with a photon beam from a cw 25-Watt Ar{sup +} laser. The resulting photoelectrons were energy analyzed with a 160{sup o} spherical-sector spectrometer. The electron affinity of In({sup 2}P{sub 1/2}) was determined to be 0.404 {+-} 0.009 eV and the electron affinity of thallium was determined to be 0.377 {+-} 0.013 eV. The fine-structure splittings in the ground states of the negative ions were also determined. The experimental measurements will be compared to several recent theoretical predictions.

  20. High-throughput fragment screening by affinity LC-MS.

    Science.gov (United States)

    Duong-Thi, Minh-Dao; Bergström, Maria; Fex, Tomas; Isaksson, Roland; Ohlson, Sten

    2013-02-01

    Fragment screening, an emerging approach for hit finding in drug discovery, has recently been proven effective by its first approved drug, vemurafenib, for cancer treatment. Techniques such as nuclear magnetic resonance, surface plasmon resonance, and isothemal titration calorimetry, with their own pros and cons, have been employed for screening fragment libraries. As an alternative approach, screening based on high-performance liquid chromatography separation has been developed. In this work, we present weak affinity LC/MS as a method to screen fragments under high-throughput conditions. Affinity-based capillary columns with immobilized thrombin were used to screen a collection of 590 compounds from a fragment library. The collection was divided into 11 mixtures (each containing 35 to 65 fragments) and screened by MS detection. The primary screening was performed in 3500 fragments per day). Thirty hits were defined, which subsequently entered a secondary screening using an active site-blocked thrombin column for confirmation of specificity. One hit showed selective binding to thrombin with an estimated dissociation constant (K (D)) in the 0.1 mM range. This study shows that affinity LC/MS is characterized by high throughput, ease of operation, and low consumption of target and fragments, and therefore it promises to be a valuable method for fragment screening.

  1. Premature delivery

    Directory of Open Access Journals (Sweden)

    Bernardita Donoso Bernales

    2012-09-01

    Full Text Available Preterm delivery is the single most important cause of perinatal morbidity and mortality. In Chile, preterm births have increased in the past decade, although neonatal morbidity and mortality attributable to it shows a downward trend, thanks to improvements in neonatal care of premature babies, rather than the success of obstetric preventive and therapeutic strategies. This article describes clinical entities, disease processes and conditions that constitute predisposing factors of preterm birth, as well as an outline for the prevention and clinical management of women at risk of preterm birth.

  2. Performance of a new protein A affinity membrane for the primary recovery of antibodies.

    Science.gov (United States)

    Boi, Cristiana; Dimartino, Simone; Sarti, Giulio C

    2008-01-01

    Recovery of antibodies with Protein A affinity chromatography columns has become the standard for the biotechnology industry. Membrane affinity chromatography has not yet experienced extensive application due to the lower capacity of membrane supports compared to chromatographic beads. In this work, new affinity membranes endowed with an interesting binding capacity for human IgG are studied in view of their application in the capturing step of a monoclonal antibody production process. The membranes have been extensively tested with pure IgG solutions and with a cell culture supernatant containing IgG1. The effects of feed flow rate and IgG concentration on the separation performances have been studied in detail, considering in particular binding capacity, selectivity and recovery. These new high capacity affinity membranes appear good candidates to avoid the throughput limitations and other well-known drawbacks of traditional bead-based chromatographic columns.

  3. Affinization of category O for quantum groups

    CERN Document Server

    Young, C A S

    2012-01-01

    Let g be a simple Lie algebra. We consider the category O-hat of those modules over the affine quantum group Uq(g-hat) whose Uq(g)-weights have finite multiplicity and lie in a finite union of cones generated by negative roots. We show that many properties of the category of the finite-dimensional representations naturally extend to the category O-hat. In particular, we develop the theory of q-characters and define the minimal affinizations of parabolic Verma modules. In types ABCFG we classify these minimal affinizations and conjecture a Weyl denominator type formula for their characters.

  4. Corner Transfer Matrices and Quantum Affine Algebras

    CERN Document Server

    Foda, O E; Foda, Omar; Miwa, Tetsuji

    1992-01-01

    Let H be the corner-transfer-matrix Hamiltonian for the six-vertex model in the anti-ferroelectric regime. It acts on the infinite tensor product W = V . V . V ....., where is the 2-dimensional irreducible representation of the quantum affine sl(2). We observe that H is the derivation of quantum affine sl(2), and conjecture that the eigenvectors of H form the level-1 vacuum representation of quantum affine sl(2). We report on checks in support of our conjecture.

  5. 01-ERD-111 - The Development of Synthetic High Affinity Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, J; Balhorn, R; Cosman, M; Lightstone, F; Zeller, L

    2004-02-05

    The aim of this project was to develop Synthetic High-Affinity Ligands (SHALs), which bind with high affinity and specificity to proteins of interest for national security and cancer therapy applications. The aim of producing synthetic ligands for sensory devices as an alternative to antibody-based detection assays and therapeutic agents is to overcome the drawbacks associated with antibody-based in next-generation sensors and systems. The focus area of the project was the chemical synthesis of the SHALs. The project concentrated on two different protein targets. (a) The C fragment of tetanus and botulinum toxin, potential biowarfare agents. A SHAL for tetanus or botulinum toxin would be incorporated into a sensory device for the toxins. (b) HLA-DR10, a protein found in high abundance on the surface of Non-Hodgkins Lymphoma. A SHAL specific to a tumor marker, labeled with a radionuclide, would enable the targeted delivery of radiation therapy to metastatic disease. The technical approach used to develop a SHAL for each protein target will be described in more detail below. However, in general, the development of a SHAL requires a combination of computational modeling techniques, modern nuclear magnetic resonance spectroscopy (NMR) and synthetic chemistry.

  6. Fatty acid and drug binding to a low-affinity component of human serum albumin, purified by affinity chromatography

    DEFF Research Database (Denmark)

    Vorum, H; Pedersen, A O; Honoré, B

    1992-01-01

    of two albumin components about 40% of the albumin having high affinity and about 60% having low affinity. By affinity chromatography we succeeded in purifying the low-affinity component from the mixture. The high-affinity component, however, could not be isolated. We further analyzed the fatty acid...

  7. Scaling laws in phytoplankton nutrient uptake affinity

    DEFF Research Database (Denmark)

    Lindemann, Christian; Fiksen, Øyvind; Andersen, Ken Haste

    2016-01-01

    instantaneously. Here we provide empirical evidence that the perfect sink strategy is not common in phytoplankton. Although small cells are indeed favored by a large surface to volume ratio, we show that they are punished by higher relative investment cost in order to fully benefit from the larger surface......Nutrient uptake affinity affects the competitive ability of microbial organisms at low nutrient concentrations. From the theory of diffusion limitation it follows that uptake affinity scales linearly with the cell radius. This is in conflict with some observations suggesting that uptake affinity...... to volume ratio. We show that there are two reasons for this. First, because the small cells need a higher transporter density in order to maximize their affinity, and second because the relative cost of a transporter is higher for a small than for a large cell. We suggest that this might explain why...

  8. Estimating affinities of calcium ions to proteins

    Directory of Open Access Journals (Sweden)

    Stefan Franke

    2010-03-01

    Full Text Available Stefan Franke, Julia Herfurth, Daniel HoffmannDepartment of Bioinformatics/Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, GermanyAbstract: Ca2+-ions have a range of affinities to different proteins, depending on the various functions of these proteins. This makes the determination of Ca2+-protein affinities an interesting subject for functional studies. We have investigated the performance of two methods – Fold-X and AutoDock vina – in the prediction of Ca2+-protein affinities. Both methods, although based on different energy functions, showed virtually the same correlation with experimental affinities. Guided by insight from experiment, we further derived a simple linear model based on thesolvent accessible surface of Ca2+ that had practically the same performance in terms of absolute errors as the more complex docking methods.Keywords: metal ions, binding, free energy, crystal structure, solvent accessible surface

  9. Estimating affinities of calcium ions to proteins

    Science.gov (United States)

    Franke, Stefan; Herfurth, Julia; Hoffmann, Daniel

    2010-01-01

    Ca2+-ions have a range of affinities to different proteins, depending on the various functions of these proteins. This makes the determination of Ca2+-protein affinities an interesting subject for functional studies. We have investigated the performance of two methods – Fold-X and AutoDock vina – in the prediction of Ca2+-protein affinities. Both methods, although based on different energy functions, showed virtually the same correlation with experimental affinities. Guided by insight from experiment, we further derived a simple linear model based on the solvent accessible surface of Ca2+ that had practically the same performance in terms of absolute errors as the more complex docking methods. PMID:21918621

  10. Protein purification using PDZ affinity chromatography.

    Science.gov (United States)

    Walkup, Ward G; Kennedy, Mary B

    2015-04-01

    PDZ domains function in nature as protein-binding domains within scaffold and membrane-associated proteins. They comprise approximately 90 residues and undergo specific, high-affinity interactions with complementary C-terminal peptide sequences, other PDZ domains, and/or phospholipids. We have previously shown that the specific, strong interactions of PDZ domains with their ligands make them well suited for use in affinity chromatography. This unit provides protocols for the PDZ affinity chromatography procedure that are applicable for the purification of proteins that contain PDZ domains or PDZ domain-binding ligands, either naturally or introduced by genetic engineering. We detail the preparation of affinity resins composed of PDZ domains or PDZ domain peptide ligands coupled to solid supports. These resins can be used to purify proteins containing endogenous or genetically introduced PDZ domains or ligands, eluting the proteins with free PDZ domain peptide ligands.

  11. Applications of on-line weak affinity interactions in free solution capillary electrophoresis

    DEFF Research Database (Denmark)

    Heegaard, Niels H H; Nissen, Mogens H; Chen, David D Y

    2002-01-01

    The impressive selectivity offered by capillary electrophoresis can in some cases be further increased when ligands or additives that engage in weak affinity interactions with one or more of the separated analytes are added to the electrophoresis buffer. This on-line affinity capillary...... enantiomers and on using capillary electrophoresis to characterize such interactions quantitatively. We describe the equations for binding isotherms, illustrate how selectivity can be manipulated by varying the additive concentrations, and show how the methods may be used to estimate binding constants. On......-line affinity capillary electrophoresis methods are especially valuable for enantiomeric separations and for functional characterization of the contents of biological samples that are only available in minute quantities....

  12. Purification of coagulation factor VIII by immobilized metal affinity chromatography.

    Science.gov (United States)

    Rodrigues, Estela S; Verinaud, Claudia I; Oliveira, Douglas S; Raw, Isaías; Lopes, Alexandre P Y; Martins, Elizabeth A L; Cheng, Elisabeth

    2015-01-01

    Factor VIII (FVIII) is a glycoprotein that plays an essential role in blood coagulation cascade. Purification of plasma-derived coagulation FVIII by direct application of plasma to a chromatographic column is a method of choice. Anion exchange column is a very powerful method because FVIII is strongly adsorbed, resulting in good activity recovery and high purification factor. However, vitamin-K-dependent coagulation factors coelute with FVIII. In the present study, we report the separation of vitamin-K-dependent coagulation proteins from FVIII using immobilized metal affinity chromatography (IMAC) with Cu(2+) as the metal ligand. Plasma was directly loaded to a Q Sepharose Big Beads column, and FVIII was recovered with 65% activity and a purification factor of approximately 50 times. Then, the Q Sepharose eluate was applied to the IMAC-Cu(2+) column, and FVIII was eluted with 200 mM imidazole, with up to 85% recovery of activity. The mass recovery in this fraction was less than 10% of the applied mass of protein. Vitamin-K-dependent proteins elute with imidazole concentrations of lower than 60 mM. Because of the difference in affinity, FVIII could be completely separated from the vitamin-K-dependent proteins in the IMAC column.

  13. APPROXIMATE OUTPUT REGULATION FOR AFFINE NONLINEAR SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yali DONG; Daizhan CHENG; Huashu QIN

    2003-01-01

    Output regulation for affine nonlinear systems driven by an exogenous signal is investigated in this paper. In the absence of the standard exosystem hypothesis, we assume availability of the instantaneous values of the exogenous signal and its first time-derivative for use in the control law.For affine nonlinear systems, the necessary and sufficient conditions of the solvability of approximate output regulation problem are obtained. The precise form of the control law is presented under some suitable assumptions.

  14. Applications of new affine invariant for polytopes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To study the Schneider's projection problem,Lutwak,Yang and Zhang recently introduced a new .affine invariant functional U(P) for convex polytopes in Rn.In the paper,we obtain the analytic expression of the affine-invariant U(P) defined on a specific subclass of origin-symmetric convex polytopes in Rn and give an application of U(P) to the Lp-Minkowski problem.

  15. A new series of emodin derivatives with bone affinity

    Institute of Scientific and Technical Information of China (English)

    Hong Chen; Ying Wang; Ling Leng; Mao Sheng Cheng; Peng Fei Yu; Jing Ze Zhang

    2007-01-01

    A new series of bone affinity compounds were synthesized by linking emodin with 5-fluorouracil derivatives. Their bone affinities were established by hydroxyapative (HA) affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.

  16. Synthesis of a New Series of Bone Affinity Compounds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.

  17. The connection between metal ion affinity and ligand affinity in integrin I domains

    DEFF Research Database (Denmark)

    Vorup-Jensen, Thomas; Waldron, TT; Astrof, N;

    2007-01-01

    Integrins are cell-surface heterodimeric proteins that mediate cell-cell, cell-matrix, and cell-pathogen interactions. Half of the known integrin alpha subunits contain inserted domains (I domains) that coordinate ligand through a metal ion. Although the importance of conformational changes within...... isolated I domains in regulating ligand binding has been reported, the relationship between metal ion binding affinity and ligand binding affinity has not been elucidated. Metal and ligand binding by several I domain mutants that are stabilized in different conformations are investigated using isothermal...... titration calorimetry and surface plasmon resonance studies. This work suggests an inverse relationship between metal ion affinity and ligand binding affinity (i.e. constructs with a high affinity for ligand exhibit a low affinity for metal). This trend is discussed in the context of structural studies...

  18. 基于软时间窗的产品配送与安装相分离的车辆调度优化%Optimization for vehicle routeing with separated delivery and installation of products based on soft time windows

    Institute of Scientific and Technical Information of China (English)

    庞海军; 丁以中

    2012-01-01

    In order to satisfy the unique need of logistics in electronics industry, a variant of the Vehicle Routeing Problem (VRP) is studied based on the unique characteristics of electronics industry. The synchronism of the delivery and installation of products is separated, and a Mixed-Integer Nonlinear Programming (MINP) model is presented to minimize the traveling time of delivery and installation, which is the optimization model of VRP for delivery and installation based on soft time windows. Comparative analysis of the results illustrates the feasibility and effectiveness of the hierarchical approach and Genetic Algorithm (GA). The method can improve the efficiency of logistics distribution, reduce the enterprises' logistics cost, and improve the service level.%为满足电子行业独特的物流配送需求,依据电子行业的特点,研究一种变形的车辆调度问题(Vehicle Routeing Problem,VRP).将产品的配送与安装的同步性进行分离,建立以最小配送和安装旅行时间为目标的混合整数非线性规划(Mixed-Integer Nonlinear Programming,MINP)模型,即基于软时间窗的配送和安装车辆调度优化模型.对算例计算结果的比较分析表明采用分层方法和遗传算法(Genetic Algorithm,GA)的可行性和有效性.该模型可以提高电子行业的物流配送效率,降低物流成本,提高服务水平.

  19. Molecular imprinted polymers for separation science: a review of reviews.

    Science.gov (United States)

    Cheong, Won Jo; Yang, Song Hee; Ali, Faiz

    2013-02-01

    Molecular imprinted polymer is an artificial receptor made by imprinting molecules of a template in a polymer matrix followed by removing the template molecules via thorough washing to give the permanent template grooves. They show favored affinity to the template molecule compared to other molecules, and this property is the basic driving force for such diverse application of this techniques. Such techniques have been increasingly employed in a wide scope of applications such as chromatography, sample pretreatment, purification, catalysts, sensors, and drug delivery, etc., mostly in bioanalytical areas. A major part of them is related to development of new stationary phases and their application in chromatography and sample pretreatment. Embodiments of molecular imprinted polymer materials have been carried out in a variety of forms such as irregularly ground particles, regular spherical particles, nanoparticles, monoliths in a stainless steel or capillary column, open tubular layers in capillaries, surface attached thin layers, membranes, and composites, etc. There have been numerous review articles on molecular imprinted polymer issues. In this special review, the reviews in recent ca. 10 years will be categorized into several subgroups according to specified topics in separation science, and each review in each subgroup will be introduced in the order of date with brief summaries and comments on new developments and different scopes of prospects. Brief summaries of each categories and conclusive future perspectives are also given.

  20. Hemoglobin-oxygen affinity in high-altitude vertebrates: is there evidence for an adaptive trend?

    Science.gov (United States)

    Storz, Jay F

    2016-10-15

    In air-breathing vertebrates at high altitude, fine-tuned adjustments in hemoglobin (Hb)-O2 affinity provide an energetically efficient means of mitigating the effects of arterial hypoxemia. However, it is not always clear whether an increased or decreased Hb-O2 affinity should be expected to improve tissue O2 delivery under different degrees of hypoxia, due to the inherent trade-off between arterial O2 loading and peripheral O2 unloading. Theoretical results indicate that the optimal Hb-O2 affinity varies as a non-linear function of environmental O2 availability, and the threshold elevation at which an increased Hb-O2 affinity becomes advantageous depends on the magnitude of diffusion limitation (the extent to which O2 equilibration at the blood-gas interface is limited by the kinetics of O2 exchange). This body of theory provides a framework for interpreting the possible adaptive significance of evolved changes in Hb-O2 affinity in vertebrates that have colonized high-altitude environments. To evaluate the evidence for an empirical generalization and to test theoretical predictions, I synthesized comparative data in a phylogenetic framework to assess the strength of the relationship between Hb-O2 affinity and native elevation in mammals and birds. Evidence for a general trend in mammals is equivocal, but there is a remarkably strong positive relationship between Hb-O2 affinity and native elevation in birds. Evolved changes in Hb function in high-altitude birds provide one of the most compelling examples of convergent biochemical adaptation in vertebrates. © 2016. Published by The Company of Biologists Ltd.

  1. Proton Affinity Calculations with High Level Methods.

    Science.gov (United States)

    Kolboe, Stein

    2014-08-12

    Proton affinities, stretching from small reference compounds, up to the methylbenzenes and naphthalene and anthracene, have been calculated with high accuracy computational methods, viz. W1BD, G4, G3B3, CBS-QB3, and M06-2X. Computed and the currently accepted reference proton affinities are generally in excellent accord, but there are deviations. The literature value for propene appears to be 6-7 kJ/mol too high. Reported proton affinities for the methylbenzenes seem 4-5 kJ/mol too high. G4 and G3 computations generally give results in good accord with the high level W1BD. Proton affinity values computed with the CBS-QB3 scheme are too low, and the error increases with increasing molecule size, reaching nearly 10 kJ/mol for the xylenes. The functional M06-2X fails markedly for some of the small reference compounds, in particular, for CO and ketene, but calculates methylbenzene proton affinities with high accuracy.

  2. Classification of neocortical interneurons using affinity propagation

    Science.gov (United States)

    Santana, Roberto; McGarry, Laura M.; Bielza, Concha; Larrañaga, Pedro; Yuste, Rafael

    2013-01-01

    In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. In fact, neuronal classification is a difficult problem because it is unclear how to designate a neuronal cell class and what are the best characteristics to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological, or molecular characteristics, have provided quantitative and unbiased identification of distinct neuronal subtypes, when applied to selected datasets. However, better and more robust classification methods are needed for increasingly complex and larger datasets. Here, we explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. Affinity propagation outperformed Ward's method, a current standard clustering approach, in classifying the neurons into 4 subtypes. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits. PMID:24348339

  3. Scaling laws in phytoplankton nutrient uptake affinity

    Directory of Open Access Journals (Sweden)

    Christian eLindemann

    2016-03-01

    Full Text Available Nutrient uptake affinity affects the competitive ability of microbial organisms at low nutrient concentrations. From the theory of diffusion limitation it follows that uptake affinity scales linearly with the cell radius. This is in conflict with some observations suggesting that uptake affinity scales to a quantity that is closer to the square of the radius, i.e. to cell surface area. We show that this apparent conflict can be resolved by nutrient uptake theory. Pure diffusion limitation assumes that the cell is a perfect sink which means that it is able to absorb all encountered nutrients instantaneously. Here we provide empirical evidence that the perfect sink strategy is not common in phytoplankton. Although small cells are indeed favored by a large surface to volume ratio, we show that they are punished by higher relative investment cost in order to fully benefit from the larger surface to volume ratio. We show that there are two reasons for this. First, because the small cells need a higher transporter density in order to maximize their affinity, and second because the relative cost of a transporter is higher for a small than for a large cell. We suggest that this might explain why observed uptake affinities do not scale linearly with the cell radius.

  4. Classification of neocortical interneurons using affinity propagation.

    Science.gov (United States)

    Santana, Roberto; McGarry, Laura M; Bielza, Concha; Larrañaga, Pedro; Yuste, Rafael

    2013-01-01

    In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. In fact, neuronal classification is a difficult problem because it is unclear how to designate a neuronal cell class and what are the best characteristics to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological, or molecular characteristics, have provided quantitative and unbiased identification of distinct neuronal subtypes, when applied to selected datasets. However, better and more robust classification methods are needed for increasingly complex and larger datasets. Here, we explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. Affinity propagation outperformed Ward's method, a current standard clustering approach, in classifying the neurons into 4 subtypes. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.

  5. Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel

    Science.gov (United States)

    Dainiak, Maria B.; Kumar, Ashok; Galaev, Igor Yu.; Mattiasson, Bo

    2006-01-01

    Adsorption of bioparticles to affinity surfaces involves polyvalent interactions, complicating greatly the recovery of the adsorbed material. A unique system for the efficient binding and release of different cells and particles is described. Affinity-bound bioparticles and synthetic particles are detached from the macroporous hydrogel matrix, a so-called cryogel, when the cryogel undergoes elastic deformation. The particle detachment upon elastic deformation is believed to be due to breaking of many of the multipoint attachments between the particles and the affinity matrix and the change in the distance between affinity ligands when the matrix is deformed. However, no release of affinity-bound protein occurred upon elastic deformation. The phenomenon of particle detachment upon elastic deformation is believed to be of a generic nature, because it was demonstrated for a variety of bioparticles of different sizes and for synthetic particles, for different ligand–receptor pairs (IgG–protein A, sugar–ConA, metal ion–chelating ligand), and when the deformation was caused by either external forces (mechanical deformation) or internal forces (the shrinkage of thermosensitive, macroporous hydrogel upon an increase in temperature). The elasticity of cryogel monoliths ensures high recovery of captured cells under mild conditions, with highly retained viability. This property, along with their continuous porous structure makes cryogel monoliths very attractive for applications in affinity cell separation. PMID:16418282

  6. Creating Protein Affinity Reagents by Combining Peptide Ligands on Synthetic DNA Scaffolds

    Science.gov (United States)

    Williams, Berea A. R.; Diehnelt, Chris W.; Belcher, Paul; Greving, Matthew; Woodbury, Neal W.; Johnston, Stephen A.; Chaput, John C.

    2009-01-01

    A full understanding of the proteome will require ligands to all of the proteins encoded by genomes. While antibodies represent the principle affinity reagents used to bind proteins, their limitations have created a need for new ligands to large numbers of proteins. Here we propose a general concept to obtain protein affinity reagents that avoids animal immunization and iterative selection steps. Central to this process is the idea that small peptide libraries contain sequences that will bind to independent regions on a protein surface, and that these ligands can be combined on synthetic scaffolds to create high affinity bivalent reagents. To demonstrate the feasibility of this approach, an array of 4,000 unique 12-mer peptides was screened to identify sequences that bind to non-overlapping sites on the yeast regulatory protein Gal80. Individual peptide ligands were screened at different distances using a novel DNA linking strategy to identify the optimal peptide pair and peptide pair separation distance required to transform two weaker ligands into a single high affinity protein capture reagent. A synthetic antibody or synbody was created with 5 nM affinity to Gal80 that functions in conventional ELISA and pull-down assays. We validated our synthetic antibody approach by creating a second synbody to human transferrin. In both cases, we observed an increase in binding affinity of ∼1000-fold (ΔΔG = ∼4.1 kcal/mol) between the individual peptides and final bivalent synbody construct. PMID:19894711

  7. Rhythmomimetic drug delivery

    CERN Document Server

    Calderer, M Carme; Siegel, Ronald A; Yao, Lingxing

    2015-01-01

    We present modeling, analysis and numerical simulation of a prototype glucose driven drug delivery device based on chemomechanical interactions and volume phase transitions in polyelectrolyte gels. The device consists of two fluid compartments, an external cell (I) mimicking the physiological environment, and a closed chamber (II), separated by a hydrogel membrane. Cell I, which is held at constant pH and ionic strength, provides a constant supply of glucose to cell II, and also serves as clearance station for reaction products. Cell II contains the drug to be delivered to the body, an enzyme that catalyzes conversion of glucose into hydrogen ions, and a piece of marble to remove excess hydrogen ions that would otherwise overwhelm the system. When the membrane is swollen, glucose flux into Cell II is high, leading to rapid production of hydrogen ions. However, the hydrogen ions are not immediately released to Cell I but react, instead, with the negatively charged carboxyl groups of the membrane, which collaps...

  8. Stepparents' Affinity-Seeking and Affinity-Maintaining Strategies with Stepchildren.

    Science.gov (United States)

    Ganong, Lawrence; Coleman, Marilyn; Fine, Mark; Martin, Patricia

    1999-01-01

    Examines the strategies that stepparents use to develop and maintain affinity with stepchildren and the effects that these strategies have on the development of stepparent-stepchildren relationships. Thirty-one affinity-seeking strategies are identified. Results show that dyadic activities worked best, but it is important that stepchildren…

  9. Stepparents' Affinity-Seeking and Affinity-Maintaining Strategies with Stepchildren.

    Science.gov (United States)

    Ganong, Lawrence; Coleman, Marilyn; Fine, Mark; Martin, Patricia

    1999-01-01

    Examines the strategies that stepparents use to develop and maintain affinity with stepchildren and the effects that these strategies have on the development of stepparent-stepchildren relationships. Thirty-one affinity-seeking strategies are identified. Results show that dyadic activities worked best, but it is important that stepchildren…

  10. Modelling and simulation of affinity membrane adsorption.

    Science.gov (United States)

    Boi, Cristiana; Dimartino, Simone; Sarti, Giulio C

    2007-08-24

    A mathematical model for the adsorption of biomolecules on affinity membranes is presented. The model considers convection, diffusion and adsorption kinetics on the membrane module as well as the influence of dead end volumes and lag times; an analysis of flow distribution on the whole system is also included. The parameters used in the simulations were obtained from equilibrium and dynamic experimental data measured for the adsorption of human IgG on A2P-Sartoepoxy affinity membranes. The identification of a bi-Langmuir kinetic mechanisms for the experimental system investigated was paramount for a correct process description and the simulated breakthrough curves were in good agreement with the experimental data. The proposed model provides a new insight into the phenomena involved in the adsorption on affinity membranes and it is a valuable tool to assess the use of membrane adsorbers in large scale processes.

  11. On Affine Fusion and the Phase Model

    Directory of Open Access Journals (Sweden)

    Mark A. Walton

    2012-11-01

    Full Text Available A brief review is given of the integrable realization of affine fusion discovered recently by Korff and Stroppel. They showed that the affine fusion of the su(n Wess-Zumino-Novikov-Witten (WZNW conformal field theories appears in a simple integrable system known as the phase model. The Yang-Baxter equation leads to the construction of commuting operators as Schur polynomials, with noncommuting hopping operators as arguments. The algebraic Bethe ansatz diagonalizes them, revealing a connection to the modular S matrix and fusion of the su(n WZNW model. The noncommutative Schur polynomials play roles similar to those of the primary field operators in the corresponding WZNW model. In particular, their 3-point functions are the su(n fusion multiplicities. We show here how the new phase model realization of affine fusion makes obvious the existence of threshold levels, and how it accommodates higher-genus fusion.

  12. New opioid affinity labels containing maleoyl moiety.

    Science.gov (United States)

    Szatmári, I; Orosz, G; Rónai, A Z; Makó, E; Medzihradszky, K; Borsodi, A

    1999-01-01

    Opioid receptor binding properties and pharmacological profiles of novel peptides containing maleoyl function were determined in order to develop new affinity labels. Based on the enkephalin structure peptide ligands were synthesized and tested. Both in in vitro receptor binding experiments and pharmacological studies, all ligands showed agonist character with relatively high affinity (Ki values in the nanomolar range) and good to moderate selectivity. Replacement of Gly2 in the enkephalin frame with D-Ala led to higher affinities with a small decrease in selectivity. The longer peptide chains resulted in compounds with high percentage (up to 86%) of irreversible binding. The selectivity pattern of the ligands is in good agreement with the data obtained from the pharmacological assays (guinea pig ileum and mouse vas deferens bioassays). The newly synthesized peptides could be used in further studies in order to determine more detailed characteristics of the ligand-receptor interaction.

  13. Poisson Morphisms and Reduced Affine Poisson Group Actions

    Institute of Scientific and Technical Information of China (English)

    YANG Qi Lin

    2002-01-01

    We establish the concept of a quotient affine Poisson group, and study the reduced Poisson action of the quotient of an affine Poisson group G on the quotient of an affine Poisson G-variety V. The Poisson morphisms (including equivariant cases) between Poisson affine varieties are also discussed.

  14. Phosphopeptide enrichment by immobilized metal affinity chromatography

    DEFF Research Database (Denmark)

    Thingholm, Tine E.; Larsen, Martin R.

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively...... charged metal ions such as Fe3+, Ga3+, Al3+, Zr4+, and Ti4+ has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from...

  15. Periodic cyclic homology of affine Hecke algebras

    CERN Document Server

    Solleveld, Maarten

    2009-01-01

    This is the author's PhD-thesis, which was written in 2006. The version posted here is identical to the printed one. Instead of an abstract, the short list of contents: Preface 5 1 Introduction 9 2 K-theory and cyclic type homology theories 13 3 Affine Hecke algebras 61 4 Reductive p-adic groups 103 5 Parameter deformations in affine Hecke algebras 129 6 Examples and calculations 169 A Crossed products 223 Bibliography 227 Index 237 Samenvatting 245 Curriculum vitae 253

  16. Affine Invariant Character Recognition by Progressive Removing

    Science.gov (United States)

    Iwamura, Masakazu; Horimatsu, Akira; Niwa, Ryo; Kise, Koichi; Uchida, Seiichi; Omachi, Shinichiro

    Recognizing characters in scene images suffering from perspective distortion is a challenge. Although there are some methods to overcome this difficulty, they are time-consuming. In this paper, we propose a set of affine invariant features and a new recognition scheme called “progressive removing” that can help reduce the processing time. Progressive removing gradually removes less feasible categories and skew angles by using multiple classifiers. We observed that progressive removing and the use of the affine invariant features reduced the processing time by about 60% in comparison to a trivial one without decreasing the recognition rate.

  17. Control and estimation of piecewise affine systems

    CERN Document Server

    Xu, Jun

    2014-01-01

    As a powerful tool to study nonlinear systems and hybrid systems, piecewise affine (PWA) systems have been widely applied to mechanical systems. Control and Estimation of Piecewise Affine Systems presents several research findings relating to the control and estimation of PWA systems in one unified view. Chapters in this title discuss stability results of PWA systems, using piecewise quadratic Lyapunov functions and piecewise homogeneous polynomial Lyapunov functions. Explicit necessary and sufficient conditions for the controllability and reachability of a class of PWA systems are

  18. Adsorption affinity of anions on metal oxyhydroxides

    Science.gov (United States)

    Pechenyuk, S. I.; Semushina, Yu. P.; Kuz'mich, L. F.

    2013-03-01

    The dependences of anion (phosphate, carbonate, sulfate, chromate, oxalate, tartrate, and citrate) adsorption affinity anions from geometric characteristics, acid-base properties, and complex forming ability are generalized. It is shown that adsorption depends on the nature of both the anions and the ionic medium and adsorbent. It is established that anions are generally grouped into the following series of adsorption affinity reduction: PO{4/3-}, CO{3/2-} > C2O{4/2-}, C(OH)(CH2)2(COO){3/3-}, (CHOH)2(COO){2/2-} > CrO{4/2-} ≫ SO{4/2-}.

  19. Einstein's gravity from an affine model

    CERN Document Server

    Castillo-Felisola, Oscar

    2015-01-01

    We show that the effective field equations for a recently formulated affine model of gravity, in the sector of a metric (torsion-free) connection, accept general Einstein manifolds --- with or without cosmological constant --- as solutions. Moreover, these effective field equations coincide with the ones obtained from a gravitational Yang--Mills theory known as Stephenson--Kilmister--Yang theory. Additionally, we find an equivalence between a minimally coupled massless scalar field in General Relativity with a "minimally" coupled scalar field in this affine model.

  20. High-affinity benzodiazepine receptor ligands among benzodiazepines and betacarbolines with different intrinsic activity

    Energy Technology Data Exchange (ETDEWEB)

    Yliniemelae, A.; Gynther, J. (Univ. of Kuopio (Finland)); Konschin, H.; Tylli, H. (Univ. of Helsinki (Finland)); Rouvinen, J. (Univ. of Joensuu (Finland))

    1989-01-01

    Structural and electrostatic features of diazepam, flumazenil, and methyl betacarboline-3-carboxylate (BCCM) have been investigated using the molecular superimposition method. These high-affinity benzodiazepine (BZ) receptor ligands are structurally unrelated and they have different intrinsic activity. These ligands are superimposed in such a way that common structural and electrostatic features essential for the high receptor binding affinity overlap. In addition to this binding pharmacophore, there are roughly three separate binding zones in the BZ receptor, one for each class of ligands. The intrinsic activity of BZ receptor ligands depends on the molecular structures and the way the ligand approaches the receptor.

  1. Evidence of multi-affinity in the Japanese stock market

    Science.gov (United States)

    Katsuragi, Hiroaki

    2000-04-01

    Fluctuations of the Japanese stock market (Tokyo Stock Price Index: TOPIX) are analyzed using a multi-affine analysis method. In the research to date, only some simulated self-affine models have shown multi-affinity. In most experiments using observations of self-affine fractal profiles, multi-affinity has not been found. However, we find evidence of multi-affinity in fluctuations of the Japanese stock market (TOPIX). The qth-order Hurst exponent Hq varies with changes in q. This multi-affinity indicates that there are plural mechanisms that affect the same time scale as stock market price fluctuation dynamics.

  2. Crossing Chris: Some Markerian Affinities

    Directory of Open Access Journals (Sweden)

    Adrian Martin

    2010-01-01

    -pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

    Abstract (E: This essay creatively explores a group of artists, writers, and other special individuals whose work or life story can be described as having an intriguing affinity with the protean career of Chris Marker. Avoiding the ‘usual suspects’ (such as Godard or Sebald, it discusses gossip columnist Milt Machlin, record collector Harry Smith, painter Gianfranco Baruchello, writer-filmmaker Edgardo Cozarinsky, and several others. From this constellation, a particular view of Markerian poetics emerges, touching upon the meanings of anonymity, storytelling, history and archiving.

     

    Abstract (F: Cet essai brosse de manière créative le portrait d’un groupe d'artistes, d'écrivains et d'autres personnes particulières dont le travail ou la biographie peuvent être décrits comme montrant une étrange mais certaine connivence avec la carrière protéiforme de Chris Marker. Evitant les lieux communs (comme Godard ou Sebald, cet article trace des références moins attendues :

  3. Colliding waves in metric-affine gravity

    CERN Document Server

    García, A; Macías, A; Mielke, E W; Socorro, J; García, Alberto; Lämmerzahl, Claus; Macías, Alfredo; Mielke, Eckehard W.; Socorro, José

    1998-01-01

    We generalize the formulation of the colliding gravitational waves to metric-affine theories and present an example of such kind of exact solutions. The plane waves are equipped with five symmetries and the resulting geometry after the collision possesses two spacelike Killing vectors.

  4. Classification of neocortical interneurons using affinity propagation

    Directory of Open Access Journals (Sweden)

    Roberto eSantana

    2013-12-01

    Full Text Available In spite of over a century of research on cortical circuits, it is still unknown how many classes of cortical neurons exist. Neuronal classification has been a difficult problem because it is unclear what a neuronal cell class actually is and what are the best characteristics are to define them. Recently, unsupervised classifications using cluster analysis based on morphological, physiological or molecular characteristics, when applied to selected datasets, have provided quantitative and unbiased identification of distinct neuronal subtypes. However, better and more robust classification methods are needed for increasingly complex and larger datasets. We explored the use of affinity propagation, a recently developed unsupervised classification algorithm imported from machine learning, which gives a representative example or exemplar for each cluster. As a case study, we applied affinity propagation to a test dataset of 337 interneurons belonging to four subtypes, previously identified based on morphological and physiological characteristics. We found that affinity propagation correctly classified most of the neurons in a blind, non-supervised manner. In fact, using a combined anatomical/physiological dataset, our algorithm differentiated parvalbumin from somatostatin interneurons in 49 out of 50 cases. Affinity propagation could therefore be used in future studies to validly classify neurons, as a first step to help reverse engineer neural circuits.

  5. Vygotsky's and Buber's Pedagogical Perspectives: Some Affinities

    Science.gov (United States)

    Bartholo, Roberto; Tunes, Elizabeth; Tacca, Maria Carmen Villela Rosa

    2010-01-01

    The purpose of this paper is to examine the dialogical and creative character of pedagogic work by analyzing the affinities between Martin Buber's "I-Thou relation" and Lev Semenovich Vygotsky's "Zone of Proximal Development". Backed up by empirical studies on the teacher-student relation, we understand that education can only result in students'…

  6. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  7. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  8. Affine Quantization and the Initial Cosmological Singularity

    CERN Document Server

    Fanuel, Michaël

    2012-01-01

    A toy model for quantum cosmology is suggested and quantized in the light of the Affine Coherent State Quantization procedure. The quantum corrections to the classical dynamics seem to provide a potential barrier term, as already suggested in other models studied in the literature. The possible application of this method to more realistic minisuperspace models is envisaged.

  9. Modern affinity reagents: Recombinant antibodies and aptamers.

    Science.gov (United States)

    Groff, Katherine; Brown, Jeffrey; Clippinger, Amy J

    2015-12-01

    Affinity reagents are essential tools in both basic and applied research; however, there is a growing concern about the reproducibility of animal-derived monoclonal antibodies. The need for higher quality affinity reagents has prompted the development of methods that provide scientific, economic, and time-saving advantages and do not require the use of animals. This review describes two types of affinity reagents, recombinant antibodies and aptamers, which are non-animal technologies that can replace the use of animal-derived monoclonal antibodies. Recombinant antibodies are protein-based reagents, while aptamers are nucleic-acid-based. In light of the scientific advantages of these technologies, this review also discusses ways to gain momentum in the use of modern affinity reagents, including an update to the 1999 National Academy of Sciences monoclonal antibody production report and federal incentives for recombinant antibody and aptamer efforts. In the long-term, these efforts have the potential to improve the overall quality and decrease the cost of scientific research. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Transdermal drug delivery

    OpenAIRE

    Prausnitz, Mark R.; Langer, Robert

    2008-01-01

    Transdermal drug delivery has made an important contribution to medical practice, but has yet to fully achieve its potential as an alternative to oral delivery and hypodermic injections. First-generation transdermal delivery systems have continued their steady increase in clinical use for delivery of small, lipophilic, low-dose drugs. Second-generation delivery systems using chemical enhancers, non-cavitational ultrasound and iontophoresis have also resulted in clinical products; the ability ...

  11. Genetic affinities of Ukrainians from the maternal perspective.

    Science.gov (United States)

    Pshenichnov, Andrey; Balanovsky, Oleg; Utevska, Olga; Metspalu, Ene; Zaporozhchenko, Valery; Agdzhoyan, Anastasia; Churnosov, Mikhail; Atramentova, Lyubov; Balanovska, Elena

    2013-12-01

    The area of what is now the Ukraine has been the arena of large-scale demographic processes that may have left their traces in the contemporary gene pool of Ukrainians. In this study, we present new mitochondrial DNA data for 607 Ukrainians (hypervariable segment I sequences and coding region polymorphisms). To study the maternal affinities of Ukrainians at the level of separate mitochondrial haplotypes, we apply an original technique, the haplotype co-occurrence analysis. About 20% of the Ukrainian maternal gene pool is represented by lineages highly specific to Ukrainians, but is scarcely found in other populations. About 9% of Ukrainian mtDNA lineages are typical for peoples of the Volga region. We also identified minor gene pool strata (1.6-3.3%), each of which is common in Lithuanians, Estonians, Saami, Nenets, Cornish, and the populations of the North Caucasus.

  12. Self-similar and self-affine sets; measure of the intersection of two copies

    CERN Document Server

    Elekes, Márton; Máthé, András

    2007-01-01

    Let K be a self-similar or self-affine set in R^d, let \\mu be a self-similar or self-affine measure on it, and let G be the group of affine maps, similitudes, isometries or translations of R^d. Under various assumptions (such as separation conditions or we assume that the transformations are small perturbations or that K is a so called Sierpinski sponge) we prove theorems of the following types, which are closely related to each other; Non-stability: There exists a constant c 0 \\iff int_K (K\\cap g(K)) is nonempty (where int_K is interior relative to K). Extension: The measure \\mu has a G-invariant extension to R^d. Moreover, in many situations we characterize those g's for which \\mu(K\\cap g(K) > 0 holds.

  13. Cross-linked leucaena seed gum matrix: an affinity chromatography tool for galactose-specific lectins.

    Science.gov (United States)

    Seshagirirao, Kottapalli; Leelavathi, Chaganti; Sasidhar, Vemula

    2005-05-31

    A cross-linked leucaena (Leucaena leucocephala) seed gum (CLLSG) matrix was prepared for the isolation of galactose-specific lectins by affinity chromatography. The matrix was evaluated for affinity with a known galactose-specific lectin from the seeds of snake gourd (Trichosanthes anguina). The matrix preparation was simple and inexpensive when compared to commercial galactose-specific matrices (i.e. about 1.5 US dollars/100 ml of matrix). The current method is also useful for the demonstration of the affinity chromatography technique in laboratories. Since leucaena seeds are abundant and inexpensive, and the matrix preparation is easy, CLLSG appears to be a promising tool for the separation of galactose-specific lectins.

  14. Separations chemistry of toxic metals

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.; Barr, M.; Barrans, R. [and others

    1996-04-01

    Sequestering and removing toxic metal ions from their surroundings is an increasingly active area of research and is gaining importance in light of current environmental contamination problems both within the DOE complex and externally. One method of separating metal ions is to complex them to a molecule (a ligand or chelator) which exhibits specific binding affinity for a toxic metal, even in the presence of other more benign metals. This approach makes use of the sometimes subtle differences between toxic and non-toxic metals resulting from variations in size, charge and shape. For example, toxic metals such as chromium, arsenic, and technetium exist in the environment as oxyanions, negatively charged species with a characteristic tetrahedral shape. Other toxic metals such as actinides and heavy metals are positively charged spheres with specific affinities for particular donor atoms such as oxygen (for actinides) and nitrogen (for heavy metals). In most cases the toxic metals are found in the presence of much larger quantities of less toxic metals such as sodium, calcium and iron. The selectivity of the chelators is critical to the goal of removing the toxic metals from their less toxic counterparts. The approach was to build a ligand framework that complements the unique characteristics of the toxic metal (size, charge and shape) while minimizing interactions with non-toxic metals. The authors have designed ligands exhibiting specificity for the target metals; they have synthesized, characterized and tested these ligands; and they have shown that they exhibit the proposed selectivity and cooperative binding effects.

  15. Integrin Targeted Delivery of Chemotherapeutics

    Directory of Open Access Journals (Sweden)

    Kai Chen, Xiaoyuan Chen

    2011-01-01

    Full Text Available Targeted delivery of chemotherapeutics is defined in the sense, that is, to maximize the therapeutic index of a chemotherapeutic agent by strictly localizing its pharmacological activity to the site or tissue of action. Integrins are a family of heterodimeric transmembrane glycoproteins involved in a wide range of cell-to-extracellular matrix (ECM and cell-to-cell interactions. As cell surface receptors, integrins readily interact with extracellular ligands and play a vital role in angiogenesis, leukocytes function and tumor development, which sets up integrins as an excellent target for chemotherapy treatment. The peptide ligands containing the arginine-glycine-aspartic acid (RGD, which displays a strong binding affinity and selectivity to integrins, particularly to integrin αvβ3, have been developed to conjugate with various conventional chemotherapeutic agents, such as small molecules, peptides and proteins, and nanoparticle-carried drugs for integtrin targeted therapeutic studies. This review highlights the recent advances in integrin targeted delivery of chemotherapeutic agents with emphasis on target of integrin αvβ3, and describes the considerations for the design of the diverse RGD peptide-chemotherapeutics conjugates and their major applications.

  16. Boronic acid lectin affinity chromatography (BLAC). 2. Affinity micropartitioning-mediated comparative glycosylation profiling.

    Science.gov (United States)

    Monzo, Alex; Olajos, Marcell; De Benedictis, Lorenzo; Rivera, Zuly; Bonn, Guenther K; Guttman, András

    2008-09-01

    As a continuation of our work on boronic acid lectin affinity chromatography (BLAC), in this paper we introduce an automated affinity micropartitioning approach using combined boronic acid and concanavalin A (BLAC/Con A) resin-filled micropipette tips to isolate and enrich human serum glycoproteins. The N-linked oligosaccharides of the partitioned glycoproteins were removed by PNGase F enzyme digestion, followed by 8-aminopyrene-1,3,6-trisulfonic acid labeling. Capillary gel electrophoresis with blue LED-induced fluorescence detection was applied in a multiplexed format for comparative glycan profiling. The efficiency of BLAC affinity micropartitioning was compared with that of the individual lectin and pseudolectin affinity enrichment. Finally, we report on our findings in glycosylation differences in human serum samples from healthy and prostate cancer patients by applying BLAC/Con A micropipette tip-based enrichment and comparative multicapillary gel electrophoresis analysis of the released and labeled glycans.

  17. A tetra-layer microfluidic system for peptide affinity screening through integrated sample injection.

    Science.gov (United States)

    Wang, Weizhi; Huang, Yanyan; Jin, Yulong; Liu, Guoquan; Chen, Yi; Ma, Huimin; Zhao, Rui

    2013-05-21

    A novel integrated microfluidic system was designed and fabricated for affinity peptide screening with in situ detection. A tetra-layer microfluidic hybrid chip containing two top eccentric diffluent layers, an inter-layer and a bottom screening layer, was developed as the core device of the system. The eccentric diffluent layers were ingeniously invented for the vertical sample delivery from 2 top-inlets into 12 bottom-inlets, which eliminated the use of excessive accessories and complicated pipelines currently used in other systems. By using six pH gradient generators, the magnetic bead-based screening in 36 parallel chambers was simultaneously carried out under 6 different pH conditions from 5.4 to 8.2. This allowed simultaneous screening of 6 compounds and each under 6 different pH conditions. The fabricated chip system was applied to screening of affinity peptides towards β-endorphin antibody. The affinities of the peptide ligands to the antibody were assessed by on-chip confocal detection. The results from the screening study using this system indicated that the pentapeptide with the sequence of YGGFL had the highest affinity towards β-endorphin antibody at pH 7.1, which was further confirmed by the ELISA assay using a 96-well plate format. This microfluidic screening system is automatic, low-cost and reusable for not only peptide screening but also other bioactive compounds screening towards target molecules.

  18. Affinity-based methodologies and ligands for antibody purification: advances and perspectives.

    Science.gov (United States)

    Roque, Ana C A; Silva, Cláudia S O; Taipa, M Angela

    2007-08-10

    Many successful, recent therapies for life-threatening diseases such as cancer and rheumatoid arthritis are based on the recognition between native or genetically engineered antibodies and cell-surface receptors. Although naturally produced by the immune system, the need for antibodies with unique specificities and designed for single application, has encouraged the search for novel antibody purification strategies. The availability of these products to the end-consumer is strictly related to manufacture costs, particularly those attributed to downstream processing. Over the last decades, academia and industry have developed different types of interactions and separation techniques for antibody purification, affinity-based strategies being the most common and efficient methodologies. The affinity ligands utilized range from biological to synthetic designed molecules with enhanced resistance and stability. Despite the successes achieved, the purification "paradigm" still moves interests and efforts in the continuous demand for improved separation performances. This review will focus on recent advances and perspectives in antibody purification by affinity interactions using different techniques, with particular emphasis on affinity chromatography.

  19. Network-of-queues approach to B-cell-receptor affinity discrimination

    Science.gov (United States)

    Felizzi, Federico; Comoglio, Federico

    2012-06-01

    The immune system is one of the most complex signal processing machineries in biology. The adaptive immune system, consisting of B and T lymphocytes, is activated in response to a large spectrum of pathogen antigens. B cells recognize and bind the antigen through B-cell receptors (BCRs) and this is fundamental for B-cell activation. However, the system response is dependent on BCR-antigen affinity values that span several orders of magnitude. Moreover, the ability of the BCR to discriminate between affinities at the high end (e.g., 109M-1-1010M-1) challenges the formulation of a mathematical model able to robustly separate these affinity-dependent responses. Queuing theory enables the analysis of many related processes, such as those resulting from the stochasticity of protein binding and unbinding events. Here we define a network of queues, consisting of BCR early signaling states and transition rates related to the propensity of molecular aggregates to form or disassemble. By considering the family of marginal distributions of BCRs in a given signaling state, we report a significant separation (measured as Jensen-Shannon divergence) that arises from a broad spectrum of antigen affinities.

  20. A robust assay to measure DNA topology-dependent protein binding affinity.

    Science.gov (United States)

    Litwin, Tamara R; Solà, Maria; Holt, Ian J; Neuman, Keir C

    2015-04-20

    DNA structure and topology pervasively influence aspects of DNA metabolism including replication, transcription and segregation. However, the effects of DNA topology on DNA-protein interactions have not been systematically explored due to limitations of standard affinity assays. We developed a method to measure protein binding affinity dependence on the topology (topological linking number) of supercoiled DNA. A defined range of DNA topoisomers at equilibrium with a DNA binding protein is separated into free and protein-bound DNA populations using standard nitrocellulose filter binding techniques. Electrophoretic separation and quantification of bound and free topoisomers combined with a simple normalization procedure provide the relative affinity of the protein for the DNA as a function of linking number. Employing this assay we measured topology-dependent DNA binding of a helicase, a type IB topoisomerase, a type IIA topoisomerase, a non-specific mitochondrial DNA binding protein and a type II restriction endonuclease. Most of the proteins preferentially bind negatively supercoiled DNA but the details of the topology-dependent affinity differ among proteins in ways that expose differences in their interactions with DNA. The topology-dependent binding assay provides a robust and easily implemented method to probe topological influences on DNA-protein interactions for a wide range of DNA binding proteins.

  1. Local structure of self-affine sets

    CERN Document Server

    Bandt, Christoph

    2011-01-01

    The structure of a self-similar set with open set condition does not change under magnification. For self-affine sets the situation is completely different. We consider planar self-affine Cantor sets E of the type studied by Bedford, McMullen, Gatzouras and Lalley, for which the projection onto the horizontal axis is an interval. We show that within small square neighborhoods of almost each point x in E, with respect to many product measures on address space, E is well approximated by product sets of an interval and a Cantor set. Even though E is totally disconnected, the limit sets have the product structure with interval fibres, reminiscent to the view of attractors of chaotic differentiable dynamical systems.

  2. Artificial Affinity Proteins as Ligands of Immunoglobulins

    Directory of Open Access Journals (Sweden)

    Barbara Mouratou

    2015-01-01

    Full Text Available A number of natural proteins are known to have affinity and specificity for immunoglobulins. Some of them are widely used as reagents for detection or capture applications, such as Protein G and Protein A. However, these natural proteins have a defined spectrum of recognition that may not fit specific needs. With the development of combinatorial protein engineering and selection techniques, it has become possible to design artificial affinity proteins with the desired properties. These proteins, termed alternative scaffold proteins, are most often chosen for their stability, ease of engineering and cost-efficient recombinant production in bacteria. In this review, we focus on alternative scaffold proteins for which immunoglobulin binders have been identified and characterized.

  3. Weight Representations of Admissible Affine Vertex Algebras

    Science.gov (United States)

    Arakawa, Tomoyuki; Futorny, Vyacheslav; Ramirez, Luis Enrique

    2017-08-01

    For an admissible affine vertex algebra {V_k{(\\mathfrak{g})}} of type A, we describe a new family of relaxed highest weight representations of {V_k{(\\mathfrak{g})}}. They are simple quotients of representations of the affine Kac-Moody algebra {\\widehat{\\mathfrak{g}}} induced from the following {\\mathfrak{g}}-modules: (1) generic Gelfand-Tsetlin modules in the principal nilpotent orbit, in particular all such modules induced from {\\mathfrak{sl}_2}; (2) all Gelfand-Tsetlin modules in the principal nilpotent orbit that are induced from {\\mathfrak{sl}_3}; (3) all simple Gelfand-Tsetlin modules over {\\mathfrak{sl}_3}. This in particular gives the classification of all simple positive energy weight representations of {V_k{(\\mathfrak{g})}} with finite dimensional weight spaces for {\\mathfrak{g}=\\mathfrak{sl}_3}.

  4. Integrating Structured Metadata with Relational Affinity Propagation

    CERN Document Server

    Plangprasopchok, Anon; Getoor, Lise

    2010-01-01

    Structured and semi-structured data describing entities, taxonomies and ontologies appears in many domains. There is a huge interest in integrating structured information from multiple sources; however integrating structured data to infer complex common structures is a difficult task because the integration must aggregate similar structures while avoiding structural inconsistencies that may appear when the data is combined. In this work, we study the integration of structured social metadata: shallow personal hierarchies specified by many individual users on the SocialWeb, and focus on inferring a collection of integrated, consistent taxonomies. We frame this task as an optimization problem with structural constraints. We propose a new inference algorithm, which we refer to as Relational Affinity Propagation (RAP) that extends affinity propagation (Frey and Dueck 2007) by introducing structural constraints. We validate the approach on a real-world social media dataset, collected from the photosharing website ...

  5. Recent Results Regarding Affine Quantum Gravity

    CERN Document Server

    Klauder, John R

    2012-01-01

    Recent progress in the quantization of nonrenormalizable scalar fields has found that a suitable non-classical modification of the ground state wave function leads to a result that eliminates term-by-term divergences that arise in a conventional perturbation analysis. After a brief review of both the scalar field story and the affine quantum gravity program, examination of the procedures used in the latter surprisingly shows an analogous formulation which already implies that affine quantum gravity is not plagued by divergences that arise in a standard perturbation study. Additionally, guided by the projection operator method to deal with quantum constraints, trial reproducing kernels are introduced that satisfy the diffeomorphism constraints. Furthermore, it is argued that the trial reproducing kernels for the diffeomorphism constraints may also satisfy the Hamiltonian constraint as well.

  6. Methods for Fault Diagnosability Analysis of a Class of Affine Nonlinear Systems

    Directory of Open Access Journals (Sweden)

    Xiafu Peng

    2015-01-01

    Full Text Available The fault diagnosability analysis for a given model, before developing a diagnosis algorithm, can be used to answer questions like “can the fault fi be detected by observed states?” and “can it separate fault fi from fault fj by observed states?” If not, we should redesign the sensor placement. This paper deals with the problem of the evaluation of detectability and separability for the diagnosability analysis of affine nonlinear system. First, we used differential geometry theory to analyze the nonlinear system and proposed new detectability criterion and separability criterion. Second, the related matrix between the faults and outputs of the system and the fault separable matrix are designed for quantitative fault diagnosability calculation and fault separability calculation, respectively. Finally, we illustrate our approach to exemplify how to analyze diagnosability by a certain nonlinear system example, and the experiment results indicate the effectiveness of the fault evaluation methods.

  7. Folding defect affine Toda field theories

    CERN Document Server

    Robertson, C

    2013-01-01

    A folding process is applied to fused a^(1)_r defects to construct defects for the non-simply laced affi?ne Toda ?field theories of c^(1)_n, d^(2)_n and a^(2)_n at the classical level. Support for the hypothesis that these defects are integrable in the folded theories is provided by the observation that transmitted solitons retain their form. Further support is given by the demonstration that energy and momentum are conserved.

  8. Mepanipyrim haptens and antibodies with nanomolar affinity

    OpenAIRE

    Esteve Turrillas, Francesc Albert; Mercader Badia, Josep Vicent; Agulló, Consuelo; Abad Somovilla, Antonio; Abad Fuentes, Antonio

    2013-01-01

    Mepanipyrim is an anilinopyrimidine fungicide used worldwide for crop protection. With the aim of developing useful immunoreagents for mepanipyrim immunoanalysis, two new functionalized derivatives were prepared and antibodies were generated. Affinity and specificity were assessed by direct and indirect competitive ELISA using homologous and heterologous conjugates. Although all antibodies were selective for the target analyte, the immunizing hapten structure was revealed as a determinant for...

  9. Couplings in Affine Toda Field Theories

    OpenAIRE

    1992-01-01

    We present a systematic derivation for a general formula for the n-point coupling constant valid for affine Toda theories related to any simple Lie algebra {\\bf g}. All n-point couplings with $n \\geq 4$ are completely determined in terms of the masses and the three-point couplings. A general fusing rule, formulated in the root space of the Lie algebra, is derived for all n-point couplings.

  10. Thermodynamics. Using Affinities to define reversible processes

    CERN Document Server

    Ritacco, Hernán A

    2016-01-01

    In this article a definition of reversible processes in terms of differences in intensive Thermodynamics properties (Affinities) is proposed. This definition makes it possible to both define reversible processes before introducing the concept of entropy and avoid the circularity problem that follows from the Clausius definition of entropy changes. The convenience of this new definition compared to those commonly found in textbooks is demonstrated with examples.

  11. AFFINE TRANSFORMATION IN RANDOM ITERATED FUNCTION SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    熊勇; 史定华

    2001-01-01

    Random iterated function systems (IFSs) is discussed, which is one of the methods for fractal drawing. A certain figure can be reconstructed by a random IFS. One approach is presented to determine a new random IFS, that the figure reconstructed by the new random IFS is the image of the origin figure reconstructed by old IFS under a given affine transformation. Two particular examples are used to show this approach.

  12. Integral affine Schur-Weyl reciprocity

    CERN Document Server

    Fu, Qiang

    2012-01-01

    Let ${\\boldsymbol{\\mathfrak D}_{\\vartriangle}}(n)$ be the double Ringel--Hall algebra of the cyclic quiver $\\triangle(n)$ and let $\\dot{\\boldsymbol{\\mathfrak D}_{\\vartriangle}}(n)$ be the modified quantum affine algebra of ${\\boldsymbol{\\mathfrak D}_{\\vartriangle}}(n)$. We will construct an integral form $\\dot{{\\mathfrak D}_{\\vartriangle}}(n)$ for $\\dot{\\boldsymbol{\\mathfrak D}_{\\vartriangle}}(n)$ such that the natural algebra homomorphism from $\\dot{{\\mathfrak D}_{\\vartriangle}}(n)$ to the integral affine quantum Schur algebra is surjective. Furthermore, we will use Hall algebras to construct the integral form ${\\mathcal U}_{\\mathbb Z}(\\hat{\\frak{gl}}_n)$ of the universal enveloping algebra ${\\mathcal U}(\\hat{\\frak{gl}}_n)$ of the loop algebra $\\hat{\\frak{gl}}_n=\\frak{gl}_n({\\mathbb Q})\\otimes\\mathbb Q[t,t^{-1}]$, and prove that the natural algebra homomorphism from ${\\mathcal U}_\\mathbb Z(\\hat{\\frak{gl}}_n)$ to the affine Schur algebra over $\\mathbb Z$ is surjective.

  13. Overview of affinity biosensors in food analysis.

    Science.gov (United States)

    Patel, Pradip D

    2006-01-01

    The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field.

  14. On constructing purely affine theories with matter

    Science.gov (United States)

    Cervantes-Cota, Jorge L.; Liebscher, D.-E.

    2016-08-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schrödinger's purely affine theory (Schrödinger in Space-time structure. Cambridge UP, Cambridge, 1950), where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  15. On constructing purely affine theories with matter

    CERN Document Server

    Cervantes-Cota, Jorge L

    2016-01-01

    We explore ways to obtain the very existence of a space-time metric from an action principle that does not refer to it a priori. Although there are reasons to believe that only a non-local theory can viably achieve this goal, we investigate here local theories that start with Schroedinger's purely affine theory [21], where he gave reasons to set the metric proportional to the Ricci curvature aposteriori. When we leave the context of unified field theory, and we couple the non-gravitational matter using some weak equivalence principle, we can show that the propagation of shock waves does not define a lightcone when the purely affine theory is local and avoids the explicit use of the Ricci tensor in realizing the weak equivalence principle. When the Ricci tensor is substituted for the metric, the equations seem to have only a very limited set of solutions. This backs the conviction that viable purely affine theories have to be non-local.

  16. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...

  17. Assisted Vaginal Delivery

    Science.gov (United States)

    ... be needed. What are the risks for my baby if I have assisted vaginal delivery? Although the overall rate of injury to the baby as a result of assisted vaginal delivery is low, there still is a risk of ...

  18. eDelivery

    Data.gov (United States)

    US Agency for International Development — eDelivery provides the electronic packaging and delivery of closed and complete OPM investigation files to government agencies, including USAID, in a secure manner....

  19. Experimental investigation of streamer affinity for dielectric surfaces

    NARCIS (Netherlands)

    Trienekens, D.J.M.; Nijdam, S.; Akkermans, G.; Plompen, I.; Christen, T.; Ebert, U.

    2015-01-01

    We have experimentally investigated the affinity of streamers for dielectric surfaces using stroboscopic imaging and stereo photography. Affinity of streamers for dielectric surfaces was found to depend on a wide set of parameters, including pressure, voltage, dielectric material and di

  20. Goals for Postsecondary Instructional Delivery Systems.

    Science.gov (United States)

    Knapp, Stuart E.; Valentine, Carol A.

    Extrapolating from the trends in postsecondary instructional delivery systems identified by Brown, Lewis and Harcleroad, this report attempts to identify how these trends might be implemented in Oregon. Separating the systems into technology-centered and people-centered, the report proposes future applications of dial access systems, self learning…

  1. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... Kids to Be Smart About Social Media Separation Anxiety KidsHealth > For Parents > Separation Anxiety Print A A ... both of you get through it. About Separation Anxiety Babies adapt pretty well to other caregivers. Parents ...

  2. Separation Anxiety (For Parents)

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Separation Anxiety KidsHealth > For Parents > Separation Anxiety A A A ... both of you get through it. About Separation Anxiety Babies adapt pretty well to other caregivers. Parents ...

  3. Assisted delivery with forceps

    Science.gov (United States)

    ... technique your doctor may use to deliver the baby is called vacuum assisted delivery . When is a Forceps Delivery Needed? Even after ... Problems with urinating or moving your bowels after delivery For the baby, the risks are: Bumps, bruises or marks on ...

  4. Glycation of the high affinity NGF-receptor and RAGE leads to reduced ligand affinity.

    Science.gov (United States)

    Bennmann, Dorit; Kannicht, Christoph; Fisseau, Claudine; Jacobs, Kathleen; Navarette-Santos, Alexander; Hofmann, Britt; Horstkorte, Rüdiger

    2015-09-01

    AGEs are posttranslational modifications generated by irreversible non-enzymatic crosslinking reactions between sugars and proteins - a reaction referred to as glycation. Glycation, a feature of ageing, can lead to non-degradable and less functional proteins and enzymes and can additionally induce inflammation and further pathophysiological processes such as neurodegeneration. In this study we investigated the influence of glycation on the high affinity NGF-receptor TrkA and the AGE-receptor RAGE. We quantified the binding affinity of the TrkA-receptor and RAGE to their ligands by surface plasmon resonance (SPR) and compared these to the binding affinity after glycation. At the same time, we established a glycation procedure using SPR. We found that glycation of TrkA reduced the affinity to NGF by a factor of three, which could be shown to lead to a reduction of NGF-dependent neurite outgrowth in PC12 cells. Glycation of RAGE reduced binding affinity of AGEs by 10-fold.

  5. Affine Structures on a Ringed Space and Schemes

    Institute of Scientific and Technical Information of China (English)

    Fengwen AN

    2011-01-01

    The author first introduces the notion of affine structures on a ringed space and then obtains several related properties. Affine structures on a ringed space, arising from complex analytical spaces of algebraic schenes, behave like differential structures on a smooth nanifold.As one does for differential manifolds, pseudogroups of affine transformations are used to define affine atlases on a ringed space. An atlas on a space is said to be an affine structure if it is maximal. An affine structure is said to be admissible if there is a sheaf on the underlying space such that they are coincide on all affine charts, which are in deed affine open sets of a scheme. In a rigour manner, a scheme is defined to be a ringed space with a specified affine structure if the affine structures make a contribution to the cases such as analytical spaces of algebraic schemes. Particularly, by the whole of affine structures on a pace, two necessary and sufficient conditions, that two spaces are homeomorphic and that two schemes are isomorphic, coming from the main theorems of the paper, are obtained respectively. A conclusion is drawn that the whole of affine structures on a space and a scheme, as local data, encode and reflect the global properties of the space and the scheme,respectively.

  6. Spatial model of affinity maturation in germinal centers

    NARCIS (Netherlands)

    Kesmir, C.; Boer, R.J. de

    2003-01-01

    Affinity maturation of humoral responses to T-cell-dependent antigens occurs in germinal centers (GC). In GCs antigen-specific B cells undergo rounds of somatic mutations that alter their affinity. High-affinity mutants take over GCs very soon after they appear; the replacement rate is as high as 4

  7. Duals of Affine Grassmann Codes and Their Relatives

    DEFF Research Database (Denmark)

    Beelen, P.; Ghorpade, S. R.; Hoholdt, T.

    2012-01-01

    Affine Grassmann codes are a variant of generalized Reed-Muller codes and are closely related to Grassmann codes. These codes were introduced in a recent work by Beelen Here, we consider, more generally, affine Grassmann codes of a given level. We explicitly determine the dual of an affine Grassm...

  8. Metal chelate affinity precipitation of RNA and purification of plasmid DNA

    Science.gov (United States)

    Balan, Sindhu; Murphy, Jason; Galaev, Igor; Kumar, Ashok; Fox, George E.; Mattiasson, Bo; Willson, Richard C.

    2003-01-01

    The affinity of metal chelates for amino acids, such as histidine, is widely used in purifying proteins, most notably through six-histidine 'tails'. We have found that metal affinity interactions can also be applied to separation of single-stranded nucleic acids through interactions involving exposed purines. Here we describe a metal affinity precipitation method to resolve RNA from linear and plasmid DNA. A copper-charged copolymer of N-isopropyl acrylamide (NIPAM) and vinyl imidazole (VI) is used to purify plasmid from an alkaline lysate of E. coli. The NIPAM units confer reversible solubility on the copolymer while the imidazole chelates metal ions in a manner accessible to interaction with soluble ligands. RNA was separated from the plasmid by precipitation along with the polymer in the presence of 800 mM NaCl. Bound RNA could be recovered by elution with imidazole and separated from copolymer by a second precipitation step. RNA binding showed a strong dependence on temperature and on the type of buffer used.

  9. Metal chelate affinity precipitation of RNA and purification of plasmid DNA

    Science.gov (United States)

    Balan, Sindhu; Murphy, Jason; Galaev, Igor; Kumar, Ashok; Fox, George E.; Mattiasson, Bo; Willson, Richard C.

    2003-01-01

    The affinity of metal chelates for amino acids, such as histidine, is widely used in purifying proteins, most notably through six-histidine 'tails'. We have found that metal affinity interactions can also be applied to separation of single-stranded nucleic acids through interactions involving exposed purines. Here we describe a metal affinity precipitation method to resolve RNA from linear and plasmid DNA. A copper-charged copolymer of N-isopropyl acrylamide (NIPAM) and vinyl imidazole (VI) is used to purify plasmid from an alkaline lysate of E. coli. The NIPAM units confer reversible solubility on the copolymer while the imidazole chelates metal ions in a manner accessible to interaction with soluble ligands. RNA was separated from the plasmid by precipitation along with the polymer in the presence of 800 mM NaCl. Bound RNA could be recovered by elution with imidazole and separated from copolymer by a second precipitation step. RNA binding showed a strong dependence on temperature and on the type of buffer used.

  10. Identification of protein interacting partners using tandem affinity purification.

    Science.gov (United States)

    Bailey, Dalan; Urena, Luis; Thorne, Lucy; Goodfellow, Ian

    2012-02-25

    A critical and often limiting step in understanding the function of host and viral proteins is the identification of interacting cellular or viral protein partners. There are many approaches that allow the identification of interacting partners, including the yeast two hybrid system, as well as pull down assays using recombinant proteins and immunoprecipitation of endogenous proteins followed by mass spectrometry identification(1). Recent studies have highlighted the utility of double-affinity tag mediated purification, coupled with two specific elution steps in the identification of interacting proteins. This approach, termed Tandem Affinity Purification (TAP), was initially used in yeast(2,3) but more recently has been adapted to use in mammalian cells(4-8). As proof-of-concept we have established a tandem affinity purification (TAP) method using the well-characterized eukaryotic translation initiation factor eIF4E(9,10).The cellular translation factor eIF4E is a critical component of the cellular eIF4F complex involved in cap-dependent translation initiation(10). The TAP tag used in the current study is composed of two Protein G units and a streptavidin binding peptide separated by a Tobacco Etch Virus (TEV) protease cleavage sequence. The TAP tag used in the current study is composed of two Protein G units and a streptavidin binding peptide separated by a Tobacco Etch Virus (TEV) protease cleavage sequence(8). To forgo the need for the generation of clonal cell lines, we developed a rapid system that relies on the expression of the TAP-tagged bait protein from an episomally maintained plasmid based on pMEP4 (Invitrogen). Expression of tagged murine eIF4E from this plasmid was controlled using the cadmium chloride inducible metallothionein promoter. Lysis of the expressing cells and subsequent affinity purification via binding to rabbit IgG agarose, TEV protease cleavage, binding to streptavidin linked agarose and subsequent biotin elution identified numerous

  11. High-gradient magnetic affinity separation of trypsin from porcine pancreatin

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Thomas, Owen R. T.

    2002-01-01

    -scale studies approximate to95% of the endogenous trypsin present in a crude porcine pancreatin feedstock was recovered with a purification factor of approximate to4.1 at the expense of only a 4% loss in a-amylase activity. Efficient recovery of trypsin from the same feedstock was demonstrated at a vastly...

  12. Adsorption and separation of HCV particles by novel affinity aptamer-functionalized adsorbents.

    Science.gov (United States)

    Chen, Bin; Ye, Qing; Zhou, Kangping; Wang, Yefu

    2016-04-01

    A novel type of aptamer-functionalized immunoadsorbent was prepared and characterized to remove HCV particles, a promising option of extracorporeal immunoadsorption (ECI) therapy against HCV. Herein, we fabricated a HCV-specific immunoadsorbent where single-stranded DNA aptamers reported and studied previously, modified with amino group at the 5' terminus, was immobilized covalently onto surfaces of carboxylated-derivative sepharose 4FF beads through N-hydroxysuccinimide (NHS) linkage. Then the adsorbents was evaluated and characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Subsequently, we also confirmed that proposed immunoadsorbents exhibited a favorable biocompatibility as well as specificity. In addition, time-dependent effects of the eradication capacity of aptamer functionalized sepharose beads against HCV was investigated. With the optimized time point, the decontamination performance of HCV particles was assessed by real-time quantitative PCR (qPCR) followed by nucleic acid-based hybridization (NAH), which shows sorbents with an aptamer density of 2nmolligand/ml resin could remove approximately 80% (i.e. 8.9×10(6) HCV particles/ml resin) of the HCV genotype 2a cultivated in vitro and 75% (vary with the intial concentration of HCV from about 7.5×10(4)-4.4×10(5) HCV particles/ml resin) of the HCV samples from human plasma samples. All these results indicated that the novel aptamer-based adsorbents could effectively remove HCV particles and likely serve as a novel therapy option or at least supplementary for the treatment regimen of HCV.

  13. Analysis of affinely equivalent Boolean functions

    Institute of Scientific and Technical Information of China (English)

    MENG QingShu; ZHANG HuanGuo; YANG Min; WANG ZhangYi

    2007-01-01

    By some basic transforms and invariant theory, we give two results: 1) an algorithm,which can be used to judge if two Boolean functions are affinely equivalent and to obtain the equivalence relationship if they are equivalent. This is useful in studying Boolean functions and in engineering. For example, we classify all 8-variable homogeneous bent functions of degree 3 into two classes; 2) Reed-Muller codes R(4,6)/R(1,6), R(3,7)/R(1,7) are classified efficiently.

  14. Affine Coherent States in Quantum Cosmology

    CERN Document Server

    Malkiewicz, Przemyslaw

    2015-01-01

    A brief summary of the application of coherent states in the examination of quantum dynamics of cosmological models is given. We discuss quantization maps, phase space probability distributions and semiclassical phase spaces. The implementation of coherent states based on the affine group resolves the hardest singularities, renders self-adjoint Hamiltonians without boundary conditions and provides a completely consistent semi-classical description of the involved quantum dynamics. We consider three examples: the closed Friedmann model, the anisotropic Bianchi Type I model and the deep quantum domain of the Bianchi Type IX model.

  15. Latest European coelacanth shows Gondwanan affinities.

    Science.gov (United States)

    Cavin, Lionel; Forey, Peter L; Buffetaut, Eric; Tong, Haiyan

    2005-06-22

    The last European fossil occurrence of a coelacanth is from the Mid-Cretaceous of the English Chalk (Turonian, 90 million years ago). Here, we report the discovery of a coelacanth from Late Cretaceous non-marine rocks in southern France. It consists of a left angular bone showing structures that imply close phylogenetic affinities with some extinct Mawsoniidae. The closest relatives are otherwise known from Cretaceous continental deposits of southern continents and suggest that the dispersal of freshwater organisms from Africa to Europe occurred in the Late Cretaceous.

  16. Metric-affine gravitation theory and superpotentials

    Energy Technology Data Exchange (ETDEWEB)

    Giachetta, G.; Mangiarotti, L.; Saltarelli, A. [Camerino, Univ. (Italy). Dipt. di Matematica e Fisica

    1997-05-01

    They consider a metric-affine theory of gravity in which the dynamical fields are the Lorentzian metrics and the non-symmetric linear connections on the worked manifold X. Working with a Lagrangian density which is invariant under general covariant transformations and using standard tools of the calculus of variations, they study the corresponding currents. They find that the superpotential takes a nice form involving the torsion of the linear connection in a simple way and generalizing the well-known Komar superpotential. A feature of our approach is the use of the Poincare`-Cartan form in relation to the first variational formula of the calculus of variations.

  17. Affinity chromatography with an immobilized RNA enzyme.

    OpenAIRE

    Vioque, A; Altman, S

    1986-01-01

    M1 RNA, the catalytic subunit of Escherichia coli RNase P, has been covalently linked at its 3' terminus to agarose beads. Unlike M1 RNA, which is active in solution in the absence of the protein component (C5) of RNase P, the RNA linked to the beads is active only in the presence of C5 protein. Affinity chromatography of crude extracts of E. coli on a column prepared from the beads to which the RNA has been crosslinked results in the purification of C5 protein in a single step. The protein h...

  18. Affine Fullerene C60 in a GS-Quasigroup

    Directory of Open Access Journals (Sweden)

    Vladimir Volenec

    2014-01-01

    Full Text Available It will be shown that the affine fullerene C60, which is defined as an affine image of buckminsterfullerene C60, can be obtained only by means of the golden section. The concept of the affine fullerene C60 will be constructed in a general GS-quasigroup using the statements about the relationships between affine regular pentagons and affine regular hexagons. The geometrical interpretation of all discovered relations in a general GS-quasigroup will be given in the GS-quasigroup C(1/2(1+5.

  19. Affinity filtration coupled with capillary-based affinity purification for the isolation of protein complexes.

    Science.gov (United States)

    Qureshi, M S; Sheikh, Q I; Hill, R; Brown, P E; Dickman, M J; Tzokov, S B; Rice, D W; Gjerde, D T; Hornby, D P

    2013-08-01

    The isolation of complex macromolecular assemblies at the concentrations required for structural analysis represents a major experimental challenge. Here we present a method that combines the genetic power of site-specific recombination in order to selectively "tag" one or more components of a protein complex with affinity-based rapid filtration and a final step of capillary-based enrichment. This modified form of tandem affinity purification produces highly purified protein complexes at high concentrations in a highly efficient manner. The application of the method is demonstrated for the yeast Arp2/3 heptameric protein complex involved in mediating reorganization of the actin cytoskeleton.

  20. Colloidal drug delivery systems in vaccine delivery.

    Science.gov (United States)

    Beg, Sarwar; Samad, Abdus; Nazish, Iram; Sultana, Ruksar; Rahman, Mahfoozur; Ahmad, Md Zaki; Akbar, Md

    2013-01-01

    Vaccines play a vital role in the field of community medicine to combat against several diseases of human existence. Vaccines primarily trigger the acquired immune system to develop long-lasting immunity against pathogens. Conventional approaches for vaccine delivery lacks potential to target a particular antigen to develop acquired immunity by specific antibodies. Recent advancements in vaccine delivery showed that inclusion of adjuvants in vaccine formulations or delivery of them in a carrier helps in achieving desired targeting ability, reducing the immunogenicity and significant augmentation in the immune response. Colloidal carriers (liposomes, niosomes, microspheres, proteosomes, virosomes and virus like particles (VLPs), antigen cochleates, dendrimers and carbon nanotubes) have been widely explored for vaccine delivery. Further, surface engineering of these carriers with ligands, functional moieties and monoclonal antibodies tend to enhance the immune recognition potential of vaccines by differentiation of antigen specific memory T-cells. The current review, therefore, provides an updated account on the recent advancements in various colloidal delivery systems in vaccine delivery, outlining the mechanism of immune response initiated by them along with potential applications and marketed instances in an explicit manner.

  1. Controlling Separation in Turbomachines

    Science.gov (United States)

    Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard

    2010-01-01

    Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).

  2. Extraction of haemoglobin from human blood by affinity precipitation using a haptoglobin-based stimuli-responsive affinity macroligand.

    Science.gov (United States)

    Stocker-Majd, Gisela; Hilbrig, Frank; Freitag, Ruth

    2008-06-13

    Affinity precipitation was compared to affinity chromatography and batch adsorption as the final purification step in a protocol for the isolation of haemoglobin from human blood. Haptoglobin was the affinity ligand. The first steps on the process were realized by traditional methods (lyses of red blood cells followed by ammonium sulphate precipitation). For affinity chromatography (and batch adsorption) the ligand was linked to Sepharose, for affinity precipitation to a thermoresponsive polymer, namely poly(N-isopropylacrylamide). Five haptoglobin-poly(N-isopropylacrylamide) bioconjugates (affinity macroligands) were constructed with different polymer: haptoglobin-coupling ratios. Conjugation of haptoglobin to the soluble poly(N-isopropylacrylamide) apparently does not change the interaction thermodynamics with haemoglobin, as the haemoglobin binding constants calculated by a Scatchard analysis for the affinity macroligand were of the same order of magnitude as those described in the literature for the haemoglobin-haptoglobin complex in solution. Two elution protocols were used for haemoglobin release from the various affinity materials, one at pH 2, the other with 5 M urea at pH 11. Both affinity chromatography and affinity precipitation yielded a pure haemoglobin of high quality. Compared to the affinity chromatography, affinity precipitation showed a significantly higher ligand efficiency (ratio of the experimental capacity to the theoretical one). The method thus makes better use of the expensive affinity ligands. As affinity precipitation only requires small temperature changes to bring about precipitation/redissolution of the affinity complexes and a centrifugation step for recovery of the precipitate, the method in addition has advantages in term of scalability and simplicity.

  3. Affine conformal vectors in space-time

    Science.gov (United States)

    Coley, A. A.; Tupper, B. O. J.

    1992-05-01

    All space-times admitting a proper affine conformal vector (ACV) are found. By using a theorem of Hall and da Costa, it is shown that such space-times either (i) admit a covariantly constant vector (timelike, spacelike, or null) and the ACV is the sum of a proper affine vector and a conformal Killing vector or (ii) the space-time is 2+2 decomposable, in which case it is shown that no ACV can exist (unless the space-time decomposes further). Furthermore, it is proved that all space-times admitting an ACV and a null covariantly constant vector (which are necessarily generalized pp-wave space-times) must have Ricci tensor of Segré type {2,(1,1)}. It follows that, among space-times admitting proper ACV, the Einstein static universe is the only perfect fluid space-time, there are no non-null Einstein-Maxwell space-times, and only the pp-wave space-times are representative of null Einstein-Maxwell solutions. Otherwise, the space-times can represent anisotropic fluids and viscous heat-conducting fluids, but only with restricted equations of state in each case.

  4. Cyclage, catabolism, and the affine Hecke algebra

    CERN Document Server

    Blasiak, Jonah

    2010-01-01

    We identify a subalgebra \\pH_n of the extended affine Hecke algebra \\eH_n of type A. The subalgebra \\pH_n is a \\u-analogue of the monoid algebra of \\S_n \\ltimes \\ZZ_{\\geq 0}^n and inherits a canonical basis from that of \\eH_n. We show that its left cells are naturally labeled by tableaux filled with positive integer entries having distinct residues mod n, which we term \\emph{positive affine tableaux} (PAT). We then exhibit a cellular subquotient \\R_{1^n} of \\pH_n that is a \\u-analogue of the ring of coinvariants \\CC[y_1,...,y_n]/(e_1,...,e_n) with left cells labeled by PAT that are essentially standard Young tableaux with cocharge labels. Multiplying canonical basis elements by a certain element \\pi \\in \\pH_n corresponds to rotations of words, and on cells corresponds to cocyclage. We further show that \\R_{1^n} has cellular quotients \\R_\\lambda that are \\u-analogues of the Garsia-Procesi modules R_\\lambda with left cells labeled by (a PAT version of) the \\lambda-catabolizable tableaux. We give a conjectural d...

  5. Spherical functions on affine Lie groups

    CERN Document Server

    Etingof, P; Kirillov, A A; Pavel Etingof; Igor Frenkel; Alexander Kirillov Jr

    1994-01-01

    We show that the space of holomorphic functions of a fixed degree on an affine Lie group which take values in a finite-dimensional representation of this group and are equivariant with respect to (twisted) conjugacy coin- cides with the space of conformal blocks of the Wess-Zumino-Witten conformal field theory on an elliptic curve with punctures, or, equivalently,with the space of states of the Chern-Simons topological field theory in genus 1. This provides a group-theoretic realization of the Segal modular functor for elliptic curves. We also show that the the radial part of the second order Laplace operator on an affine Lie group acting in the space of equivariant functions coincides with the operator defining the Knizhnik-Zamolodchikov connection on conformal blocks on elliptic curves, and its eigenfunctions coincide with the correlation functions of conformal blocks. At the critical value of the degree (minus the dual Coxeter number of the underlying simple Lie algebra) there exist higher order Laplace op...

  6. Affine Mirkovi\\'c-Vilonen polytopes

    CERN Document Server

    Baumann, Pierre; Tingley, Peter

    2011-01-01

    Each integrable lowest weight representation of a symmetrizable Kac-Moody Lie algebra g has a crystal in the sense of Kashiwara, which describes its combinatorial properties. For a given g, there is a limit crystal, usually denoted by B(-\\infty), which contains all the other crystals. When g is finite dimensional, a convex polytope, called the Mirkovi\\'c-Vilonen polytope, can be associated to each element in B(-\\infty). This polytope sits in the dual space of a Cartan subalgebra of g, and its edges are parallel to the roots of g. In this paper, we generalize this construction to the case where g is a symmetric affine Kac-Moody algebra. The datum of the polytope must however be complemented by partitions attached to the edges parallel to the imaginary root \\delta. We prove that these decorated polytopes are characterized by conditions on their normal fans and on their 2-faces. In addition, we discuss how our polytopes provide an analog of the notion of Lusztig datum for affine Kac-Moody algebras. Our main tool...

  7. LISA propulsion module separation study

    Energy Technology Data Exchange (ETDEWEB)

    Merkowitz, S M [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ahmad, A [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hyde, T T [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sweetser, T [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Ziemer, J [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Conkey, S [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States); III, W Kelly [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States); Shirgur, B [Swales Aerospace, 5050 Powder Mill Road, Beltsville, MD 20705 (United States)

    2005-05-21

    The Laser Interferometer Space Antenna (LISA) mission is a space-borne gravitational wave detector consisting of three sciencecraft in heliocentric orbit. Each sciencecraft is delivered to its operational orbit by a propulsion module. Because of the strict thermal and mass balancing requirements of LISA, the baseline mission concept requires that the propulsion module separate from the sciencecraft after delivery. The only propulsion system currently included in the sciencecraft design are micronewton level thrusters, such as field emission electric propulsion (FEEP) or colloid thrusters, that are used to balance the 30-40 {mu}N of solar radiation pressure and provide the drag-free and attitude control of the sciencecraft. Due to these thrusters' limited authority, the separation of the propulsion module from the sciencecraft must be well controlled to not induce a large tip-off rotation of the sciencecraft. We present here the results of a study of the propulsion module separation system requirements that are necessary to safely deliver the three LISA sciencecraft to their final operational orbits.

  8. High Affinity Binding of Indium and Ruthenium Ions by Gastrins.

    Directory of Open Access Journals (Sweden)

    Graham S Baldwin

    Full Text Available The peptide hormone gastrin binds two ferric ions with high affinity, and iron binding is essential for the biological activity of non-amidated forms of the hormone. Since gastrins act as growth factors in gastrointestinal cancers, and as peptides labelled with Ga and In isotopes are increasingly used for cancer diagnosis, the ability of gastrins to bind other metal ions was investigated systematically by absorption spectroscopy. The coordination structures of the complexes were characterized by extended X-ray absorption fine structure (EXAFS spectroscopy. Changes in the absorption of gastrin in the presence of increasing concentrations of Ga3+ were fitted by a 2 site model with dissociation constants (Kd of 3.3 x 10-7 and 1.1 x 10-6 M. Although the absorption of gastrin did not change upon the addition of In3+ ions, the changes in absorbance on Fe3+ ion binding in the presence of indium ions were fitted by a 2 site model with Kd values for In3+ of 6.5 x 10-15 and 1.7 x 10-7 M. Similar results were obtained with Ru3+ ions, although the Kd values for Ru3+ of 2.6 x 10-13 and 1.2 x 10-5 M were slightly larger than observed for In3+. The structures determined by EXAFS all had metal:gastrin stoichiometries of 2:1 but, while the metal ions in the Fe, Ga and In complexes were bridged by a carboxylate and an oxygen with a metal-metal separation of 3.0-3.3 Å, the Ru complex clearly demonstrated a short range Ru-Ru separation, which was significantly shorter, at 2.4 Å, indicative of a metal-metal bond. We conclude that gastrin selectively binds two In3+ or Ru3+ ions, and that the affinity of the first site for In3+ or Ru3+ ions is higher than for ferric ions. Some of the metal ion-gastrin complexes may be useful for cancer diagnosis and therapy.

  9. 76 FR 4726 - Avaya Global Services, AOS Service Delivery, Worldwide Services Group, Including Workers Whose...

    Science.gov (United States)

    2011-01-26

    ... Employment and Training Administration Avaya Global Services, AOS Service Delivery, Worldwide Services Group... Assistance on October 20, 2010, applicable to workers of Avaya Global Services, AOS Service Delivery... Avaya Global Services, AOS Service Delivery had their wages reported through a separate...

  10. Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

    Science.gov (United States)

    Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

    2016-08-26

    Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach.

  11. Evaluation of non-covalent interactions between serum albumin and green tea catechins by affinity capillary electrophoresis.

    Science.gov (United States)

    Zinellu, Angelo; Sotgia, Salvatore; Scanu, Bastianina; Pisanu, Elisabetta; Giordo, Roberta; Cossu, Annalisa; Posadino, Anna Maria; Carru, Ciriaco; Pintus, Gianfranco

    2014-11-07

    The natural antioxidant-associated biological responses appear contradictory since biologically active dosages registered in vitro experiments are considerably higher if compared to concentrations found in vivo. The recent research indicates that natural antioxidants, including the major catechins of green tea epicatechin (EC), epigallocatechin (EGC), epicatechingallate (ECG) and epigallocatechingallate (EGCG) form non-covalent complexes with albumin, a crucial aspect that may modulate their plasma concentration, tissue delivery and biological activity. Affinity capillary electrophoresis (ACE) was used to characterize the binding of the four catechins to human serum albumin (HSA) and bovine serum albumin (BSA) at near-physiological conditions: 10 mmol/L phosphate buffer, HEPES 50 mmol/L (pH 7.5), temperature 37°C. The studied flavonoids displayed affinities toward the albumin with binding constants in the range 10(3)-10(5)M(-1), with a greater affinity of catechins toward HSA than BSA (between 3 and 3.5 fold higher). We also confirmed that catechins having a galloyl moiety (ECG and EGCG) have a higher binding affinity toward albumin than the catechins lacking the galloyl moiety (EC and EGC), and that for both albumins the order of affinity is EC

  12. Biofunctionalization of silica microspheres for protein separation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Binjie [Institute of Immunology, Henan University, Kaifeng 475004 (China); Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zou, Xueyan [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Zhao, Yanbao, E-mail: yanbaozhao@126.com [Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Sun, Lei [Institute of Immunology, Henan University, Kaifeng 475004 (China); Key Laboratory of Ministry of Education for Special Functional Materials, Henan University, Kaifeng 475004 (China); Li, Shulian [Institute of Immunology, Henan University, Kaifeng 475004 (China)

    2013-07-01

    Mercapto-silica (SiO{sub 2}–SH) microspheres were prepared via direct hydrolysis of 3-mercaptopropyltrimethoxysilane (MPS) in a basic aqueous solution. The content of surface thiol group (-SH) of SiO{sub 2}–SH microspheres was measured by Ellman's reagent method and X-ray photoelectron spectroscopy (XPS) and the content of surface thiol group of SiO{sub 2}–SH microspheres is strongly dependent on the reaction conditions. The thermal stability of SiO{sub 2}–SH microspheres was evaluated by thermogravimetric (TG) analysis, which tended to reduce with the increase of content of surface thiol groups. SiO{sub 2}–SH microspheres can be easily modified with reduced glutathione (GSH) to generate SiO{sub 2}–GSH microspheres for the affinity separation of Glutathione S-transferase (GST). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to examine the validity of the separation procedure. The results showed that SiO{sub 2}–GSH microspheres were efficient in GST affinity separation from mixed proteins. - Graphical abstract: The prepared SiO{sub 2}–SH microsphere binding reduced glutathione (SiO{sub 2}–GSH) as affinity precipitation support can capture selectively Glutathione S-transferase (GST) from mixed protein solution. Highlights: ► SiO{sub 2}–SH microspheres were prepared in water using one-pot synthesis. ► The content of surface -SH was investigated by Ellman method and XPS spectra. ► The ratio of -SH to mass strongly depends on the reaction conditions. ► SiO{sub 2}–SH microspheres were biofunctionalized by glutathione. ► SiO{sub 2}–GSH can be used to capture selectively Glutathione S-transferase.

  13. The Monitoring and Affinity Purification of Proteins Using Dual Tags with Tetracysteine Motifs

    Science.gov (United States)

    Giannone, Richard J.; Liu, Yie; Wang, Yisong

    Identification and characterization of protein-protein interaction networks is essential for the elucidation of biochemical mechanisms and cellular function. Affinity purification in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as a very powerful tactic for the identification of specific protein-protein interactions. In this chapter, we describe a comprehensive methodology that uses our recently developed dual-tag affinity purification system for the enrichment and identification of mammalian protein complexes. The protocol covers a series of separate but sequentially related techniques focused on the facile monitoring and purification of a dual-tagged protein of interest and its interacting partners via a system built with tetracysteine motifs and various combinations of affinity tags. Using human telomeric repeat binding factor 2 (TRF2) as an example, we demonstrate the power of the system in terms of bait protein recovery after dual-tag affinity purification, detection of bait protein subcellular localization and expression, and successful identification of known and potentially novel TRF2 interacting proteins. Although the protocol described here has been optimized for the identification and characterization of TRF2-associated proteins, it is, in principle, applicable to the study of any other mammalian protein complexes that may be of interest to the research community.

  14. Multi-Graph Matching via Affinity Optimization with Graduated Consistency Regularization.

    Science.gov (United States)

    Yan, Junchi; Cho, Minsu; Zha, Hongyuan; Yang, Xiaokang; Chu, Stephen M

    2016-06-01

    This paper addresses the problem of matching common node correspondences among multiple graphs referring to an identical or related structure. This multi-graph matching problem involves two correlated components: i) the local pairwise matching affinity across pairs of graphs; ii) the global matching consistency that measures the uniqueness of the pairwise matchings by different composition orders. Previous studies typically either enforce the matching consistency constraints in the beginning of an iterative optimization, which may propagate matching error both over iterations and across graph pairs; or separate affinity optimization and consistency enforcement into two steps. This paper is motivated by the observation that matching consistency can serve as a regularizer in the affinity objective function especially when the function is biased due to noises or inappropriate modeling. We propose composition-based multi-graph matching methods to incorporate the two aspects by optimizing the affinity score, meanwhile gradually infusing the consistency. We also propose two mechanisms to elicit the common inliers against outliers. Compelling results on synthetic and real images show the competency of our algorithms.

  15. A polymer nanoparticle with engineered affinity for a vascular endothelial growth factor (VEGF165)

    Science.gov (United States)

    Koide, Hiroyuki; Yoshimatsu, Keiichi; Hoshino, Yu; Lee, Shih-Hui; Okajima, Ai; Ariizumi, Saki; Narita, Yudai; Yonamine, Yusuke; Weisman, Adam C.; Nishimura, Yuri; Oku, Naoto; Miura, Yoshiko; Shea, Kenneth J.

    2017-07-01

    Protein affinity reagents are widely used in basic research, diagnostics and separations and for clinical applications, the most common of which are antibodies. However, they often suffer from high cost, and difficulties in their development, production and storage. Here we show that a synthetic polymer nanoparticle (NP) can be engineered to have many of the functions of a protein affinity reagent. Polymer NPs with nM affinity to a key vascular endothelial growth factor (VEGF165) inhibit binding of the signalling protein to its receptor VEGFR-2, preventing receptor phosphorylation and downstream VEGF165-dependent endothelial cell migration and invasion into the extracellular matrix. In addition, the NPs inhibit VEGF-mediated new blood vessel formation in Matrigel plugs in vivo. Importantly, the non-toxic NPs were not found to exhibit off-target activity. These results support the assertion that synthetic polymers offer a new paradigm in the search for abiotic protein affinity reagents by providing many of the functions of their protein counterparts.

  16. Project delivery system (PDS)

    CERN Document Server

    2001-01-01

    As business environments become increasingly competitive, companies seek more comprehensive solutions to the delivery of their projects. "Project Delivery System: Fourth Edition" describes the process-driven project delivery systems which incorporates the best practices from Total Quality and is aligned with the Project Management Institute and ISO Quality Standards is the means by which projects are consistently and efficiently planned, executed and completed to the satisfaction of clients and customers.

  17. Cesarean Delivery in Adolescents.

    Science.gov (United States)

    Katz Eriksen, Jennifer L; Melamed, Alexander; Clapp, Mark A; Little, Sarah E; Zera, Chloe

    2016-10-01

    To examine the effect of maternal age on indication for primary cesarean delivery in low-risk nulliparous women. Retrospective cohort study. Urban academic tertiary care center. Nulliparous women younger than 35 years of age delivering vertex-presenting singletons at term. Participants underwent spontaneous, operative or cesarean delivery. Mode of delivery, indication, and timing of cesarean delivery. Adolescents were half as likely to undergo cesarean delivery overall (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.43-0.54), and more than one-third less likely to undergo cesarean delivery in labor (OR, 0.59; 95% CI, 0.53-0.66). Adjustment for potential confounders did not alter the strength of these associations. Adolescents were half as likely to undergo cesarean delivery for failure to progress (OR, 0.49; 95% CI, 0.43-0.54). There was no difference in the odds of cesarean delivery for nonreassuring fetal status (OR, 0.91; 95% CI, 0.77-1.06), or genital herpes (OR, 1.44; 95% CI, 0.57-3.68). Induction, macrosomia, oxytocin augmentation, and any labor complication were all associated with increased risk of cesarean delivery. There was no difference in the duration of second stage for adolescents who delivered by cesarean delivery compared with adults (240.0 vs 237.7 minutes; P = .84), but adolescents who delivered vaginally had a second stage that was one-third shorter than adults (62.5 vs 100.3 minutes; P cesarean delivery overall, and 40% less likely to undergo a primary cesarean delivery in labor, even after adjustment for multiple maternal, neonatal, and labor characteristics. This difference is not explained by differences in the duration of the second stage of labor. Copyright © 2016 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  18. Biomolecular transport and separation in nanotubular networks.

    Energy Technology Data Exchange (ETDEWEB)

    Stachowiak, Jeanne C.; Stevens, Mark Jackson (Sandia National Laboratories, Albuquerque, NM); Robinson, David B.; Branda, Steven S.; Zendejas, Frank; Meagher, Robert J.; Sasaki, Darryl Yoshio; Bachand, George David (Sandia National Laboratories, Albuquerque, NM); Hayden, Carl C.; Sinha, Anupama; Abate, Elisa; Wang, Julia; Carroll-Portillo, Amanda (Sandia National Laboratories, Albuquerque, NM); Liu, Haiqing (Sandia National Laboratories, Albuquerque, NM)

    2010-09-01

    Cell membranes are dynamic substrates that achieve a diverse array of functions through multi-scale reconfigurations. We explore the morphological changes that occur upon protein interaction to model membrane systems that induce deformation of their planar structure to yield nanotube assemblies. In the two examples shown in this report we will describe the use of membrane adhesion and particle trajectory to form lipid nanotubes via mechanical stretching, and protein adsorption onto domains and the induction of membrane curvature through steric pressure. Through this work the relationship between membrane bending rigidity, protein affinity, and line tension of phase separated structures were examined and their relationship in biological membranes explored.

  19. Gene Therapy Vectors with Enhanced Transfection Based on Hydrogels Modified with Affinity Peptides

    Science.gov (United States)

    Shepard, Jaclyn A.; Wesson, Paul J.; Wang, Christine E.; Stevans, Alyson C.; Holland, Samantha J.; Shikanov, Ariella; Grzybowski, Bartosz A.; Shea, Lonnie D.

    2011-01-01

    Regenerative strategies for damaged tissue aim to present biochemical cues that recruit and direct progenitor cell migration and differentiation. Hydrogels capable of localized gene delivery are being developed to provide a support for tissue growth, and as a versatile method to induce the expression of inductive proteins; however, the duration, level, and localization of expression isoften insufficient for regeneration. We thus investigated the modification of hydrogels with affinity peptides to enhance vector retention and increase transfection within the matrix. PEG hydrogels were modified with lysine-based repeats (K4, K8), which retained approximately 25% more vector than control peptides. Transfection increased 5- to 15-fold with K8 and K4 respectively, over the RDG control peptide. K8- and K4-modified hydrogels bound similar quantities of vector, yet the vector dissociation rate was reduced for K8, suggesting excessive binding that limited transfection. These hydrogels were subsequently applied to an in vitro co-culture model to induce NGF expression and promote neurite outgrowth. K4-modified hydrogels promoted maximal neurite outgrowth, likely due to retention of both the vector and the NGF. Thus, hydrogels modified with affinity peptides enhanced vector retention and increased gene delivery, and these hydrogels may provide a versatile scaffold for numerous regenerative medicine applications. PMID:21514659

  20. Eudragit E100 as a drug carrier: the remarkable affinity of phosphate ester for dimethylamine.

    Science.gov (United States)

    Guzmán, M L; Manzo, R H; Olivera, M E

    2012-09-04

    Therapeutic agents containing phosphate groups in their molecules have increasing therapeutic impact. The object of this study was to characterize the cationic polyelectrolyte Eudragit E100 (EuE100) as a carrier for drugs containing phosphate groups, using dexamethasone phosphate (DP) as a model. A series of EuE100-DP complexes was obtained by acid-base reaction in which DP neutralized 12.5-75% of the basic groups of EuE100. The solids obtained after solvent evaporation revealed by spectroscopic characterization the complete reaction between the components through the ionic interaction between the amine groups of EuE100 and the phosphate groups of DP. The reversibility of the counterion condensation, evaluated through the proton-withdrawing effect produced by the ionic exchange generated by titration with NaCl, showed a remarkable high affinity between EuE100 and DP. In line, drug delivery in bicompartimental Franz cells toward water as receptor medium was very slow (2% in 6 h). However, it was increased as water was replaced by NaCl solution, which upon diffusion generates ionic exchange. A sustained release of DP with noticeable zero order kinetics accounted for a remarkable high affinity, mainly due to the electrostatic attraction. The release rate remains constant regardless of the saline concentration of the media. Besides, the delivery control is maintained even in gastric simulated fluid, a property not informed previously for EuE100 complexes.

  1. Apomorphine and its esters: Differences in Caco-2 cell permeability and chylomicron affinity.

    Science.gov (United States)

    Borkar, Nrupa; Chen, Zhizhong; Saaby, Lasse; Müllertz, Anette; Håkansson, Anders E; Schönbeck, Christian; Yang, Mingshi; Holm, René; Mu, Huiling

    2016-07-25

    Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine, monolauroyl apomorphine (MLA) and dilauroyl apomorphine (DLA) were subjected to apical to basolateral (A-B) and basolateral to apical (B-A) transport across Caco-2 cell monolayer. The stability of these compounds was also assessed by incubation at intestinal pH and physiological pH with and without Caco-2 cells. Molecular dynamics (MD) simulations were performed to understand the stability of the esters on a molecular level. The affinity of the compounds towards plasma derived chylomicrons was assessed. The A-B transport of intact DLA was about 150 times lower than the transport of apomorphine. In contrast, MLA was highly unstable in the aqueous media leading to apomorphine appearance basolaterally. MD simulations possibly explained the differences in hydrolysis susceptibilities of DLA and MLA. The affinity of apomorphine diesters towards plasma derived chylomicrons provided an understanding of their potential lymphatic transport. The intact DLA transport is not favorable; therefore, the conversion of DLA to MLA is an important step for intestinal apomorphine absorption.

  2. Size and shape dependent deprotonation potential and proton affinity of nanodiamond

    Science.gov (United States)

    Barnard, Amanda S.; Per, Manolo C.

    2014-11-01

    Many important reactions in biology and medicine involve proton abstraction and transfer, and it is integral to applications such as drug delivery. Unlike electrons, which are quantum mechanically delocalized, protons are instantaneously localized on specific residues in these reactions, which can be a distinct advantage. However, the introduction of nanoparticles, such as non-toxic nanodiamonds, to this field complicates matters, as the number of possible sites increases as the inverse radius of the particle. In this paper we present \\gt {{10}4} simulations that map the size- and shape-dependence of the deprotonation potential and proton affinity of nanodiamonds in the range 1.8-2.7 nm in average diameter. We find that while the average deprotonation potential and proton affinities decrease with size, the site-specific values are inhomogeneous over the surface of the particles, exhibiting strong shape-dependence. The proton affinity is strongly facet-dependent, whereas the deprotonation potential is edge/corner-dependent, which creates a type of spatial hysteresis in the transfer of protons to and from the nanodiamond, and provides new opportunities for selective functionalization.

  3. Liposome-encapsulated hemoglobin reduces the size of cerebral infarction in rats: effect of oxygen affinity.

    Science.gov (United States)

    Fukumoto, Dai; Kawaguchi, Akira T; Haida, Munetaka; Yamano, Mariko; Ogata, Yoshitaka; Tsukada, Hideo

    2009-02-01

    Liposome-encapsulated hemoglobin (LEH) with a low oxygen affinity (l-LEH, P(50) = 45 mm Hg) was found to be protective in the rodent and primate models of ischemic stroke. This study investigated the role of LEH with a high O(2) affinity (h-LEH, P(50) = 10 mm Hg) in its protective effect on brain ischemia. The extent of cerebral infarction was determined 24 h after photochemically induced thrombosis of the middle cerebral artery from the integrated area of infarction detected by triphenyltetrazolium chloride staining in rats receiving various doses of h-LEH as well as l-LEH. Both h-LEH and l-LEH significantly reduced the extent of cortical infarction. h-LEH remained protective at a lower concentration (minimal effective dose [MED]: 0.08 mL/kg) than l-LEH (MED: 2 mL/kg) in the cortex. h-LEH reduced the infarction extent in basal ganglia as well (MED: 0.4 mL/kg), whereas l-LEH provided no significant protection. h-LEH provided better protection than l-LEH. The protective effect of both high- and low-affinity LEH may suggest the importance of its small particle size (230 nm) as compared to red blood cells. The superiority of h-LEH over l-LEH supports an optimal O(2) delivery to the ischemic penumbra as the mechanism of action in protecting against brain ischemia and reperfusion.

  4. Buccal drug delivery.

    Science.gov (United States)

    Smart, John D

    2005-05-01

    Buccal formulations have been developed to allow prolonged localised therapy and enhanced systemic delivery. The buccal mucosa, however, while avoiding first-pass effects, is a formidable barrier to drug absorption, especially for biopharmaceutical products (proteins and oligonucleotides) arising from the recent advances in genomics and proteomics. The buccal route is typically used for extended drug delivery, so formulations that can be attached to the buccal mucosa are favoured. The bioadhesive polymers used in buccal drug delivery to retain a formulation are typically hydrophilic macro-molecules containing numerous hydrogen bonding groups. Newer second-generation bioadhesives have been developed and these include modified or new polymers that allow enhanced adhesion and/or drug delivery, in addition to site-specific ligands such as lectins. Over the last 20 years a wide range of formulations has been developed for buccal drug delivery (tablet, patch, liquids and semisolids) but comparatively few have found their way onto the market. Currently, this route is restricted to the delivery of a limited number of small lipophilic molecules that readily cross the buccal mucosa. However, this route could become a significant means for the delivery of a range of active agents in the coming years, if the barriers to buccal drug delivery are overcome. In particular, patient acceptability and the successful systemic delivery of large molecules (proteins, oligonucleotides and polysaccharides) via this route remains both a significant opportunity and challenge, and new/improved technologies may be required to address these.

  5. Affine connection form of Regge calculus

    CERN Document Server

    Khatsymovsky, V M

    2015-01-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the 3-simplices which play a role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4,R) of the connection matrices. As a result, we have some action invariant w. r. t. arbitrary change of coordinates of the vertices (and related GL(4,R) transformations in...

  6. Gravitational Goldstone fields from affine gauge theory

    CERN Document Server

    Tresguerres, R

    2000-01-01

    In order to facilitate the application of standard renormalization techniques, gravitation should be decribed, if possible, in pure connection formalism, as a Yang-Mills theory of a certain spacetime group, say the Poincare or the affine group. This embodies the translational as well as the linear connection. However, the coframe is not the standard Yang-Mills type gauge field of the translations, since it lacks the inhomogeneous gradient term in the gauge transformations. By explicitly restoring the "hidden" piece responsible for this behavior within the framework of nonlinear realizations, the usual geometrical interpretation of the dynamical theory becomes possible, and in addition one can avoid the metric or coframe degeneracy which would otherwise interfere with the integrations within the path integral. We claim that nonlinear realizations provide a general mathematical scheme clarifying the foundations of gauge theories of spacetime symmetries. When applied to construct the Yang-Mills theory of the aff...

  7. Automatic gesture analysis using constant affine velocity.

    Science.gov (United States)

    Cifuentes, Jenny; Boulanger, Pierre; Pham, Minh Tu; Moreau, Richard; Prieto, Flavio

    2014-01-01

    Hand human gesture recognition has been an important research topic widely studied around the world, as this field offers the ability to identify, recognize, and analyze human gestures in order to control devices or to interact with computer interfaces. In particular, in medical training, this approach is an important tool that can be used to obtain an objective evaluation of a procedure performance. In this paper, some obstetrical gestures, acquired by a forceps, were studied with the hypothesis that, as the scribbling and drawing movements, they obey the one-sixth power law, an empirical relationship which connects path curvature, torsion, and euclidean velocity. Our results show that obstetrical gestures have a constant affine velocity, which is different for each type of gesture and based on this idea this quantity is proposed as an appropriate classification feature in the hand human gesture recognition field.

  8. Self-affinity and nonextensivity of sunspots

    Energy Technology Data Exchange (ETDEWEB)

    Moret, M.A., E-mail: mamoret@gmail.com [Programa de Modelagem Computacional, SENAI, Cimatec, Av. Orlando Gomes, 1845, Piatã, 41650-010 Salvador, Bahia (Brazil); UNEB, Rua Silveira Martins, 2555, Cabula, 41150-000 Salvador, Bahia (Brazil)

    2014-01-24

    In this paper we study the time series of sunspots by using two different approaches, analyzing its self-affine behavior and studying its distribution. The long-range correlation exponent α has been calculated via Detrended Fluctuation Analysis and the power law vanishes to values greater than 11 years. On the other hand, the distribution of the sunspots obeys a q-exponential decay that suggests a non-extensive behavior. This observed characteristic seems to take an alternative interpretation of the sunspots dynamics. The present findings suggest us to propose a dynamic model of sunspots formation based on a nonlinear Fokker–Planck equation. Therefore its dynamic process follows the generalized thermostatistical formalism.

  9. Affine and Projective Tree Metric Theorems

    CERN Document Server

    Harel, Matan; Pachter, Lior

    2011-01-01

    The tree metric theorem provides a combinatorial four point condition that characterizes dissimilarity maps derived from pairwise compatible split systems. A similar (but weaker) four point condition characterizes dissimilarity maps derived from circular split systems (Kalmanson metrics). The tree metric theorem was first discovered in the context of phylogenetics and forms the basis of many tree reconstruction algorithms, whereas Kalmanson metrics were first considered by computer scientists, and are notable in that they are a non-trivial class of metrics for which the traveling salesman problem is tractable. We present a unifying framework for these theorems based on combinatorial structures that are used for graph planarity testing. These are (projective) PC-trees, and their affine analogs, PQ-trees. In the projective case, we generalize a number of concepts from clustering theory, including hierarchies, pyramids, ultrametrics and Robinsonian matrices, and the theorems that relate them. As with tree metric...

  10. Affine trajectory correction for nonholonomic mobile robots

    CERN Document Server

    Pham, Quang-Cuong

    2011-01-01

    Planning trajectories for nonholonomic systems is difficult and computationally expensive. When facing unexpected events, it may therefore be preferable to deform in some way the initially planned trajectory rather than to re-plan entirely a new one. We suggest here a method based on affine transformations to make such deformations. This method is exact and fast: the deformations and the resulting trajectories can be computed algebraically, in one step, and without any trajectory re-integration. To demonstrate the possibilities offered by this new method, we use it to derive position correction, orientation correction, obstacle avoidance and feedback control algorithms for the general class of planar wheeled robots and for a tridimensional underwater vehicle.

  11. Dynamic friction of self-affine surfaces

    Science.gov (United States)

    Schmittbuhl, Jean; Vilotte, Jean-Pierre; Roux, Stéphane

    1994-02-01

    We investigate the velocity dependence of the friction between two rigid blocks limited by a self-affine surface such as the one generated by a crack. The upper solid is subjected either to gravity or to an external elastic stiffness, and is driven horizontally at constant velocity, V, while the lower solid is fixed. For low velocities, the apparent friction coefficient is constant. For high velocities, the apparent friction is shown to display a velocity weakening. The weakening can be related to the variation of the mean contact time due to the occurrence of jumps during the motions. The cross-over between these two regimes corresponds to a characteristic velocity which depends on the geometry of the surfaces and on the mean normal force. In the case of simple gravity loading, the velocity dependence of the apparent friction at high velocities is proportional to 1/V^2 where V is the imposed tangential velocity. In the case of external elastic stiffness, two velocity weakening regimes can be identified, the first is identical to the gravity case with a 1/V^2 dependence, the second appears at higher velocities and is characterized by a 1/V variation. The characteristic velocity of this second cross-over depends on the roughness and the elastic stiffness. The statistical distribution of ballistic flight distances is analysed, and is shown to reveal in all cases the self-affinity of the contacting surfaces. Nous analysons la dépendence en vitesse du frottement entre deux solides limités par une surface rugueuse auto-affine comme celle d'une surface de fracture. Le solide supérieur est soumis soit à la gravité, soit à une raideur élastique externe, et est entraîné à vitesse horizontale constante V sur le solide inférieur fixe. A faible vitesse, le coefficient de friction apparent, est constant. A forte vitesse, le coefficient de friction apparent devient inversement proportionnel à la vitesse. Cette dépendance peut être reliée à la variation du temps

  12. Data Stream Clustering With Affinity Propagation

    KAUST Repository

    Zhang, Xiangliang

    2014-07-09

    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  13. Identification of proteins interacting with ammodytoxins in Vipera ammodytes ammodytes venom by immuno-affinity chromatography.

    Science.gov (United States)

    Brgles, Marija; Kurtović, Tihana; Kovačič, Lidija; Križaj, Igor; Barut, Miloš; Lang Balija, Maja; Allmaier, Günter; Marchetti-Deschmann, Martina; Halassy, Beata

    2014-01-01

    In order to perform their function, proteins frequently interact with other proteins. Various methods are used to reveal protein interacting partners, and affinity chromatography is one of them. Snake venom is composed mostly of proteins, and various protein complexes in the venom have been found to exhibit higher toxicity levels than respective components separately. Complexes can modulate envenomation activity of a venom and/or potentiate its effect. Our previous data indicate that the most toxic components of the Vipera ammodytes ammodytes (Vaa) venom isolated so far-ammodytoxins (Atxs)-are contributing to the venom's toxicity only moderately; therefore, we aimed to explore whether they have some interacting partner(s) potentiating toxicity. For screening of possible interactions, immuno-affinity chromatography combined with identification by mass spectrometry was used. Various chemistries (epoxy, carbonyldiimidazole, ethylenediamine) as well as protein G functionality were used to immobilize antibodies on monolith support, a Convective Interaction Media disk. Monoliths have been demonstrated to better suit the separation of large biomolecules. Using such approach, several proteins were indicated as potential Atx-binding proteins. Among these, the interaction of Atxs with a Kunitz-type inhibitor was confirmed by far-Western dot-blot and surface plasmon resonance measurement. It can be concluded that affinity chromatography on monolithic columns combined with mass spectrometry identification is a successful approach for screening of protein interactions and it resulted with detection of the interaction of Atx with Kunitz-type inhibitor in Vaa venom for the first time.

  14. Separation anxiety in children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001542.htm Separation anxiety in children To use the sharing features on this page, please enable JavaScript. Separation anxiety in children is a developmental stage in which ...

  15. Ionene membrane battery separator

    Science.gov (United States)

    Moacanin, J.; Tom, H. Y.

    1969-01-01

    Ionic transport characteristics of ionenes, insoluble membranes from soluble polyelectrolyte compositions, are studied for possible application in a battery separator. Effectiveness of the thin film of separator membrane essentially determines battery lifetime.

  16. Magnetic separation of algae

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  17. Magnetic particles as affinity matrix for purification of antithrombin

    Science.gov (United States)

    Mercês, A. A. D.; Maciel, J. C.; Carvalho Júnior, L. B.

    2015-11-01

    Immobilization of biomolecules onto insoluble supports is an important tool for the fabrication of a diverse range of functional materials. It provides advantages: enhanced stability and easy separation. In this work two different magnetic composites were synthesized (MAG-PANI-HS and mDAC-HS) to human antithrombin purification. The magnetic particles (MAG) were obtained by co-precipitation method of iron salts II and III and subsequently coated with polyaniline (MAG-PANI particles). Dacron (polyethylene terephthalate) suffered a hydrazinolysis reaction to obtain a powder (Dacron hydrazide) which was subsequently magnetized (mDAC particles) also by co-precipitation method. Heparan sulfate (HS) was immobilized to MAG-PANI and mDAC retained respectively 35μg and 38.6μg per of support. The magnetic composite containing HS immobilized (MAG-PANI-HS and mDAC-HS) was incubated with human blood plasma (1mL) and then washed with NaCl gradients. Electrophoresis of proteins present in eluates showed bands of antithrombin (58kDa). A reduction in the antithrombin activity was detected in plasma that were incubated in the composites magnetic with HS immobilized, suggesting that the antithrombin was removed of the human blood plasma and then purified. Therefore, the above results suggest that both preparations: MAG-PANI-HS and mDAC-HS are able to affinity purify antithrombin, an important component of blood coagulation.

  18. Polysaccharide zeta-potentials and protein-affinity.

    Science.gov (United States)

    Comert, Fatih; Azarikia, Fatemeh; Dubin, Paul L

    2017-08-09

    The ζ-potential, a parameter typically obtained by model-dependent transformation of the measured electrophoretic mobility, is frequently used to understand polysaccharide-protein complexation. We tested the hypothesis that two anionic polysaccharides with identical ζ-potentials would show equal binding affinity to the protein β-lactoglobulin (BLG). We selected two polysaccharide polyelectrolytes (PE) with very different structures: hyaluronic acid (HA) and tragacanthin (TG). Highly precise (±0.1%) turbidimetric titrations were performed to determine critical pH values of complex formation; and PE ζ-potentials were measured for different ionic strengths I at those critical pH values. While phase boundaries (pHcvs. I) showed that HA binds to BLG more strongly (e.g. at a lower pH, for fixed I), comparisons made at fixed ζ-potential indicated that TG binds more strongly. The source of this contradiction is the effect of the bulky side chains of TG on its friction coefficient which diminishes its mobility and hence the resultant ζ-potential; while having a distinctly separate effect on the interaction between BLG and the carboxylated backbone of TG. Thus, unless the locus of the bound protein coincides with the shear plane, the ζ-potential does not directly contribute to the electrostatic PE-protein interaction.

  19. Questioning hagfish affinities of the enigmatic Devonian vertebrate Palaeospondylus

    Science.gov (United States)

    Johanson, Zerina; Smith, Moya; Sanchez, Sophie; Senden, Tim; Trinajstic, Kate; Pfaff, Cathrin

    2017-07-01

    Palaeospondylus gunni Traquair, 1890 is an enigmatic Devonian vertebrate whose taxonomic affinities have been debated since it was first described. Most recently, Palaeospondylus has been identified as a stem-group hagfish (Myxinoidea). However, one character questioning this assignment is the presence of three semicircular canals in the otic region of the cartilaginous skull, a feature of jawed vertebrates. Additionally, new tomographic data reveal that the following characters of crown-group gnathostomes (chondrichthyans + osteichthyans) are present in Palaeospondylus: a longer telencephalic region of the braincase, separation of otic and occipital regions by the otico-occipital fissure, and vertebral centra. As well, a precerebral fontanelle and postorbital articulation of the palatoquadrate are characteristic of certain chondrichthyans. Similarities in the structure of the postorbital process to taxa such as Pucapampella, and possible presence of the ventral cranial fissure, both support a resolution of Pa. gunni as a stem chondrichthyan. The internally mineralized cartilaginous skeleton in Palaeospondylus may represent a stage in the loss of bone characteristic of the Chondrichthyes.

  20. How membrane permeation is affected by donor delivery solvent.

    Science.gov (United States)

    Binks, Bernard P; Fletcher, Paul D I; Johnson, Andrew J; Elliott, Russell P

    2012-11-28

    We investigate theoretically and experimentally how the rate and extent of membrane permeation is affected by switching the donor delivery solvent from water to squalane for different permeants and membranes. In a model based on rate-limiting membrane diffusion, we derive explicit equations showing how the permeation extent and rate depend mainly on the membrane-donor and membrane-receiver partition coefficients of the permeant. Permeation results for systems containing all combinations of hydrophilic or hydrophobic donor solvents (aqueous solution or squalane), permeants (caffeine or testosterone) and polymer membranes (cellulose or polydimethylsiloxane) have been measured using a cell with stirred donor and re-circulating receiver compartments and continuous monitoring of the permeant concentration in the receiver phase. Relevant partition coefficients are also determined. Quantitative comparison of model and experimental results for the widely-differing permeation systems successfully enables the systematic elucidation of all possible donor solvent effects in membrane permeation. For the experimental conditions used here, most of the permeation systems are in agreement with the model, demonstrating that the model assumptions are valid. In these cases, the dominant donor solvent effects arise from changes in the relative affinities of the permeant for the donor and receiver solvents and the membrane and are quantitatively predicted using the separately measured partition coefficients. We also show how additional donor solvent effects can arise when switching the donor solvent causes one or more of the model assumptions to be invalid. These effects include a change in rate-limiting step, permeant solution non-ideality and others.

  1. Indefinite Affine Hyperspheres Admitting a Pointwise Symmetry. Part 2

    Directory of Open Access Journals (Sweden)

    Christine Scharlach

    2009-10-01

    Full Text Available An affine hypersurface M is said to admit a pointwise symmetry, if there exists a subgroup G of Aut(T_pM for all p in M, which preserves (pointwise the affine metric h, the difference tensor K and the affine shape operator S. Here, we consider 3-dimensional indefinite affine hyperspheres, i.e. S = HId (and thus S is trivially preserved. In Part 1 we found the possible symmetry groups G and gave for each G a canonical form of K. We started a classification by showing that hyperspheres admitting a pointwise Z_2 × Z_2 resp. R-symmetry are well-known, they have constant sectional curvature and Pick invariant J < 0 resp. J = 0. Here, we continue with affine hyperspheres admitting a pointwise Z_3- or SO(2-symmetry. They turn out to be warped products of affine spheres (Z_3 or quadrics (SO(2 with a curve.

  2. Classical affine W-algebras associated to Lie superalgebras

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Uhi Rinn, E-mail: uhrisu1@math.snu.ac.kr [Department of Mathematical Sciences, Seoul National University, GwanAkRo 1, Gwanak-Gu, Seoul 151-747 (Korea, Republic of)

    2016-02-15

    In this paper, we prove classical affine W-algebras associated to Lie superalgebras (W-superalgebras), which can be constructed in two different ways: via affine classical Hamiltonian reductions and via taking quasi-classical limits of quantum affine W-superalgebras. Also, we show that a classical finite W-superalgebra can be obtained by a Zhu algebra of a classical affine W-superalgebra. Using the definition by Hamiltonian reductions, we find free generators of a classical W-superalgebra associated to a minimal nilpotent. Moreover, we compute generators of the classical W-algebra associated to spo(2|3) and its principal nilpotent. In the last part of this paper, we introduce a generalization of classical affine W-superalgebras called classical affine fractional W-superalgebras. We show these have Poisson vertex algebra structures and find generators of a fractional W-superalgebra associated to a minimal nilpotent.

  3. Kinetic Gravity Separation

    NARCIS (Netherlands)

    Van Kooy, L.; Mooij, M.; Rem, P.

    2004-01-01

    Separations by density, such as the separation of non-ferrous scrap into light and heavy alloys, are often realized by means of heavy media. In principle, kinetic gravity separations in water can be faster and cheaper, because they do not rely on suspensions or salt solutions of which the density

  4. Surfaces in 4-space from the affine differential geometry viewpoint

    OpenAIRE

    Luis Florial Espinoza Sánchez

    2014-01-01

    In this thesis, we study locally strictly convex surfaces from the affine differential viewpoint and generalize some tools for locally strictly submanifolds of codimension 2. We introduce a family of affine metrics on a locally strictly convex surface M in affine 4-space. Then, we define the symmetric and antisymmetric equiaffine planes associated with each metric. We show that if M is immersed in a locally atrictly convex hyperquadric, then the symmetric and the antisymmetric planes coincid...

  5. Fast Affinity Propagation Clustering based on Machine Learning

    OpenAIRE

    Shailendra Kumar Shrivastava; J. L. Rana; DR.R.C.JAIN

    2013-01-01

    Affinity propagation (AP) was recently introduced as an un-supervised learning algorithm for exemplar based clustering. In this paper a novel Fast Affinity Propagation clustering Approach based on Machine Learning (FAPML) has been proposed. FAPML tries to put data points into clusters based on the history of the data points belonging to clusters in early stages. In FAPML we introduce affinity learning constant and dispersion constant which supervise the clustering process. FAPML also enforces...

  6. Abacus models for parabolic quotients of affine Weyl groups

    CERN Document Server

    Hanusa, Christopher R H

    2011-01-01

    We introduce abacus diagrams that describe minimal length coset representatives in affine Weyl groups of types B, C, and D. These abacus diagrams use a realization of the affine Weyl group of type C due to Eriksson to generalize a construction of James for the symmetric group. We also describe several combinatorial models for these parabolic quotients that generalize classical results in affine type A related to core partitions.

  7. Prediction of preterm delivery

    NARCIS (Netherlands)

    Wilms, F.F.

    2014-01-01

    Preterm delivery is in quantity and in severity an important issue in the obstetric care in the Western world. There is considerable knowledge on maternal and obstetric risk factors of preterm delivery. Of the women presenting with preterm labor, the majority is pregnant with a male fetus and in

  8. Prediction of preterm delivery

    NARCIS (Netherlands)

    Wilms, F.F.

    2014-01-01

    Preterm delivery is in quantity and in severity an important issue in the obstetric care in the Western world. There is considerable knowledge on maternal and obstetric risk factors of preterm delivery. Of the women presenting with preterm labor, the majority is pregnant with a male fetus and in Cau

  9. Delivery by Cesarean Section

    Science.gov (United States)

    ... often when: The mother has had a previous baby by Cesarean delivery The obstetrician feels that the baby’s health might ... lost time. Don’t be surprised if your baby is still affected by the anesthesia for six to twelve hours after delivery and appears a little sleepy. If you’re ...

  10. Vacuum-assisted delivery

    Science.gov (United States)

    ... a handle on the cup to move the baby through the birth canal. When is Vacuum-assisted Delivery Needed? Even after your cervix is fully dilated ( ... delivers the baby's head, you will push the baby the rest of the way out. After delivery, you can hold your baby on your tummy ...

  11. Microscale characterization of the binding specificity and affinity of a monoclonal antisulfotyrosyl IgG antibody

    DEFF Research Database (Denmark)

    Lassen, K.S.; Bradbury, A.R.; Heegaard, N.H.;

    2008-01-01

    peptides and proteins. The data show that the anti-Tyr(SO(3)H) antibody is completely specific for compounds containing sulfated tyrosyls. Affinity electrophoresis experiments allowed us to estimate dissociation constants for sulfated hirudin fragment (56-65), gastrin-17, and cholecystokinin octapeptide...... (CCK8) in the 1-3 microM range. The affinity of the antibody toward complement 4 protein that contains three sulfotyrosines was analyzed by surface plasmon resonance technology and modeled according to a bivalent-binding model which yielded a K(d1) of 20.1 microM for the monovalent complex. The same...... binding was studied by CE and found to be in the micromolar scale albeit with some uncertainty due to complex separation patterns. The work illustrates the amount of information on antibody-antigen interactions that may be obtained with microelectrophoretic methods consuming minute quantities of material...

  12. Coupled Cluster Studies of Ionization Potentials and Electron Affinities of Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Bo; Govind, Niranjan; Aprà, Edoardo; Klemm, Michael; Hammond, Jeff R.; Kowalski, Karol

    2017-02-03

    In this paper we apply equation-of-motion coupled cluster (EOMCC) methods in studies of vertical ionization potentials (IP) and electron affinities (EA) for sin- gled walled carbon nanotubes. EOMCC formulations for ionization potentials and electron affinities employing excitation manifolds spanned by single and double ex- citations (IP/EA-EOMCCSD) are used to study IPs and EAs of nanotubes as a function of nanotube length. Several armchair nanotubes corresponding to C20nH20 models with n = 2 - 6 have been used in benchmark calculations. In agreement with previous studies, we demonstrate that the electronegativity of C20nH20 systems remains, to a large extent, independent of nanotube length. We also compare IP/EA- EOMCCSD results with those obtained with the coupled cluster models with single and double excitations corrected by perturbative triples, CCSD(T), and density func- tional theory (DFT) using global and range-separated hybrid exchange-correlation functionals.

  13. Efficient purification of unique antibodies using peptide affinity-matrix columns

    DEFF Research Database (Denmark)

    Jensen, Liselotte Brix; Riise, Erik; Nielsen, Leif Kofoed

    2004-01-01

    fragments and had no affinity for other antibodies. Using this peptide matrix MK16 IgG could be purified from cell culture supernatants thereby separating MK16 IgG from bovine IgG normally present in the enriched growth media used for such cells. Investigations of the fine specificity of the ER6.1 peptide......Phage display technology was used to identify peptide ligands with unique specificity for a monoclonal model antibody, MK16, that recognises the human multiple sclerosis associated MHC class II molecule DR2 in complex with a myelin basic protein (MBP)-derived peptide corresponding to residue 85......-99. Several peptide epitopes were identified and all of them recognised specifically MK16. One peptide, ER6.1, was selected and linked to beaded agarose and demonstrated excellent performance as a peptide affinity chromatography matrix. This epitope matrix was efficient in the purification of MK16 Fab...

  14. Organic Microporous Nanofillers with Unique Alcohol Affinity for Superior Ethanol Recovery toward Sustainable Biofuels.

    Science.gov (United States)

    Cheng, Xi Quan; Konstas, Kristina; Doherty, Cara M; Wood, Colin D; Mulet, Xavier; Xie, Zongli; Ng, Derrick; Hill, Matthew R; Lau, Cher Hon; Shao, Lu

    2017-05-09

    To minimize energy consumption and carbon footprints, pervaporation membranes are fast becoming the preferred technology for alcohol recovery. However, this approach is confined to small-scale operations, as the flux of standard rubbery polymer membranes remain insufficient to process large solvent volumes, whereas membrane separations that use glassy polymer membranes are prone to physical aging. This study concerns how the alcohol affinity and intrinsic porosity of networked, organic, microporous polymers can simultaneously reduce physical aging and drastically enhance both flux and selectivity of a super glassy polymer, poly-[1-(trimethylsilyl)propyne] (PTMSP). Slight loss in alcohol transportation channels in PTMSP is compensated by the alcohol affinity of the microporous polymers. Even after continuous exposure to aqueous solutions of alcohols, PTMSP pervaporation membranes loaded with the microporous polymers outperform the state-of-the-art and commercial pervaporation membranes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Inhibition of Xanthine Oxidase Activity by Gnaphalium Affine Extract

    Institute of Scientific and Technical Information of China (English)

    Wei-qing Lin; Jian-xiang Xie; Xiao-mu Wu; Lin Yang; Hai-dong Wang

    2014-01-01

    Objective To evaluate the inhibitory effect of Gnaphalium affine extracts on xanthine oxidase (XO) activity in vitro and to analyze the mechanism of this effect. Methods In this in vitro study, Kinetic measurements were performed in 4 different inhibitor concentrations and 5 different xanthine concentrations (60, 100, 200, 300, 400 μmol/L). Dixon and Lineweaver-Burk plot analysis were used to determine Ki values and the inhibition mode for the compounds isolated from Gnaphalium affine extract. Results Four potent xanthine oxidase inhibitors were found in 95% ethanolic (v/v) Gnaphalium affine extract. Among them, the flavone Eupatilin exhibited the strongest inhibitory effect on XO with a inhibition constant (Ki) of 0.37μmol/L, lower than the Ki of allopurinol (4.56 mol/L), a known synthetic XO inhibitor. Apigenin (Ki of 0.56μmol/L, a proportion of 0.0053‰in Gnaphalium affine), luteolin (Ki of 2.63 μmol/L, 0.0032‰ in Gnaphalium affine) and 5-hydroxy-6,7,3’,4’-tetramethoxyflavone (Ki of 3.15μmol/L, 0.0043‰ in Gnaphalium affine) also contributed to the inhibitory effect of Gnaphalium affine extract on XO activity. Conclusions These results suggest that the use of Gnaphalium affine in the treatment of gout could be attributed to its inhibitory effect on XO. This study provides a rational basis for the traditional use of Gnaphalium affine against gout.

  16. Surface immobilization of hexa-histidine-tagged adeno-associated viral vectors for localized gene delivery.

    Science.gov (United States)

    Jang, J-H; Koerber, J T; Gujraty, K; Bethi, S R; Kane, R S; Schaffer, D V

    2010-11-01

    Adeno-associated viral (AAV) vectors, which are undergoing broad exploration in clinical trials, have significant promise for therapeutic gene delivery because of their safety and delivery efficiency. Gene delivery technologies capable of mediating localized gene expression may further enhance the potential of AAV in a variety of therapeutic applications by reducing spread outside a target region, which may thereby reduce off-target side effects. We have genetically engineered an AAV variant capable of binding to surfaces with high affinity through a hexa-histidine metal-binding interaction. This immobilized AAV vector system mediates high-efficiency delivery to cells that contact the surface and thus may have promise for localized gene delivery, which may aid numerous applications of AAV delivery to gene therapy.

  17. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  18. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  19. Exploiting large-pore metal-organic frameworks for separations through entropic molecular mechanisms

    NARCIS (Netherlands)

    Torres-Knoop, A.; Dubbeldam, D.

    2015-01-01

    We review the molecular mechanisms behind adsorption and the separations of mixtures in metal-organic frameworks and zeolites. Separation mechanisms can be based on differences in the affinity of the adsorbate with the framework and on entropic effects. To develop next-generation adsorbents, the

  20. Exploiting large-pore metal-organic frameworks for separations through entropic molecular mechanisms

    NARCIS (Netherlands)

    A. Torres-Knoop; D. Dubbeldam

    2015-01-01

    We review the molecular mechanisms behind adsorption and the separations of mixtures in metal-organic frameworks and zeolites. Separation mechanisms can be based on differences in the affinity of the adsorbate with the framework and on entropic effects. To develop next-generation adsorbents, the sep

  1. Amortised Resource Analysis with Separation Logic

    CERN Document Server

    Atkey, Robert

    2011-01-01

    Type-based amortised resource analysis following Hofmann and Jost---where resources are associated with individual elements of data structures and doled out to the programmer under a linear typing discipline---have been successful in providing concrete resource bounds for functional programs, with good support for inference. In this work we translate the idea of amortised resource analysis to imperative pointer-manipulating languages by embedding a logic of resources, based on the affine intuitionistic Logic of Bunched Implications, within Separation Logic. The Separation Logic component allows us to assert the presence and shape of mutable data structures on the heap, while the resource component allows us to state the consumable resources associated with each member of the structure. We present the logic on a small imperative language, based on Java bytecode, with procedures and mutable heap. We have formalised the logic and its soundness property within the Coq proof assistant and extracted a certified ver...

  2. The cohomology of the affine Deligne-Lusztig varieties in the affine flag manifold of $GL_2$

    CERN Document Server

    Ivanov, Alexander

    2009-01-01

    This paper studies affine Deligne-Lusztig varieties in the affine flag manifold of GL_2. At first we determine all such varieties up to isomorphy. After this we investigate the representations of the sigma-stabilizer of an element b of the group on the etale cohomology of the affine Deligne-Lusztig variety X_w(b). We describe such representations as inductions from compact subgroups and in terms of noncuspidal representations.

  3. Chiral separation of racemic drugs using molecular imprinting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Molecularly imprinted polymers (MIPs) of (S)-ketoprofen and (S)-naproxen are prepared using non-covalent imprinting in the presence of template molecules. The prepared MIPs are used as the chiral stationary phase to separate ramemic naproxen and ketoprofen. The results show that racemic naproxen and ketoprofen are efficiently resolved on MIPs. The effect of concentration of acetic acid in the mobile phase is studied, and the data are analyzed using the affinity chromatography model, and the close agreement is achieved between the simulated and experimental curves. The results suggest that the affinity chromatography mechanism controls the retention in this system. Moreover, the affinity chromatography equilibrium constants on (S)-naproxen and (S)-ketoprofen are estimated.

  4. Affine connection form of Regge calculus

    Science.gov (United States)

    Khatsymovsky, V. M.

    2016-12-01

    Regge action is represented analogously to how the Palatini action for general relativity (GR) as some functional of the metric and a general connection as independent variables represents the Einstein-Hilbert action. The piecewise flat (or simplicial) spacetime of Regge calculus is equipped with some world coordinates and some piecewise affine metric which is completely defined by the set of edge lengths and the world coordinates of the vertices. The conjugate variables are the general nondegenerate matrices on the three-simplices which play the role of a general discrete connection. Our previous result on some representation of the Regge calculus action in terms of the local Euclidean (Minkowsky) frame vectors and orthogonal connection matrices as independent variables is somewhat modified for the considered case of the general linear group GL(4, R) of the connection matrices. As a result, we have some action invariant w.r.t. arbitrary change of coordinates of the vertices (and related GL(4, R) transformations in the four-simplices). Excluding GL(4, R) connection from this action via the equations of motion we have exactly the Regge action for the considered spacetime.

  5. Platelet affinity for burro aorta collagen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.D.

    1977-10-01

    Despite ingenious concepts, there are no unequivocal clues as to what, when, and how some undefined biochemical factor(s) or constituent(s) that localizes in the arterial wall can precipitate a thromboatheromatous lesion or arterial disease. The present study focused on the extraction, partial purification, and characterization of a collagen-active platelet stimulator from the aortas of aged burros. The aggregator moiety in the aorta extracts invariably had a higher affinity for platelets in citrated platelet-rich plasma of human beings than for platelets of homologous burros. The platelet-aggregating factor(s) in the aorta extract was retained by incubation with ..cap alpha..-chymotrypsin. Platelet-aggregating activity was rapidly abolished after incubation with collagenase, as determined by platelet-aggregometry tests. Evidence based on light microscope and polysaccharide histochemical reactions indicates a probability that the intracellular amorphous matrix (PAS-positive) and filamentous components (PTAH-positive) expelled from smooth muscle cells disrupted during homogenization of the aorta may be a principal source of a precursor collagen species which is a potent inducer of platelet aggregation.

  6. Affinity of guanosine derivatives for polycytidylate revisited

    Science.gov (United States)

    Kanavarioti, A.; Hurley, T. B.; Baird, E. E.

    1995-01-01

    Evidence is presented for complexation of guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) with polycytidylate (poly(C)) at pH 8.0 and 23 degrees C in the presence of 1.0 M NaCl2 and 0.2 M MgCl2 in water. The association of 2-MeImpG with poly(C) was investigated using UV-vis spectroscopy as well as by monitoring the kinetics of the nucleophilic substitution reaction of the imidazole moiety by amines. The results of both methods are consistent with moderately strong poly(C) 2-MeImpG complexation and the spectrophotometric measurements allowed the construction of a binding isotherm with a concentration of 2-MeImpG equal to 5.55 +/- 0.15 mM at half occupancy. UV spectroscopy was employed to establish the binding of other guanosine derivatives on poly(C). These derivatives are guanosine 5'-monophosphate (5'GMP), guanosine 5'-monophosphate imidazolide (ImpG), and guanosine 5'-monophosphate morpholidate (morpG). Within experimental error these guanosine derivatives exhibit the same affinity for poly(C) as 2-MeImpG.

  7. Automation of the isotopic separation of hydrogen through gas chromatography; Automatisation des procedes de separation isotopique des hydrogenes par chromatographie en phase gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Laquerbe, C.; Steimetz, J.; Demoment, J. [CEA Valduc, 21 - Is-sur-Tille (France); Leterq, D. [CEA Bruyeres-le-Chatel, 91 (France)

    2007-07-01

    The thermal cycling absorption process (TCAP) is a separation technique that can be considered as an evolution of the discontinuous chromatography in gaseous phase used in Cea-Dam for the isotopic separation of tritium. The shift in affinity of the palladium for the 3 hydrogen isotopes allows their separation. In the TCAP process we use the shift of the separation property in terms of operating temperatures: the ability to separate is significant at the ambient temperature while it is almost zero over 1000 C degrees. Preliminary studies have allowed the selection of palladium deposits on alumina as lining. 2 pilot installations have been designed. (A.C.)

  8. Anticancer medicines (Doxorubicin and methotrexate) conjugated with magnetic nanoparticles for targeting drug delivery through iron.

    Science.gov (United States)

    Samra, Zahoor Qadir; Ahmad, Snober; Javeid, Mehwish; Dar, Nadia; Aslam, Muhammad Shahbaz; Gull, Iram; Ahmad, Mubashar Mustaneer

    2013-01-01

    The uptake of iron is increased by cancer cells. Iron magnetic nanoparticles (MNP) can be used as a nanovehicle for immobilization of anticancer medicines and to integrate them at a target site. The anticancer medicines doxorubicin (DOX) and methotrexate (MTX) were immobilized separately and in combination onto MNP by a glutaraldehyde activation method and confirmed by magnetic nanoparticles linked immunosorbent assay (MagLISA) and Fourier-transform infrared (FTIR) spectroscopy. The phenol peaks of DOX and MTX at 2896.6 cm⁻¹ to 2912.5 cm⁻¹ in FTIR spectra of immobilized medicines indicated the conjugation. Affinity-purified anti-DOX and anti-MTX antibodies were used to evaluate the coupling of DOX and MTX onto MNP, and the binding was found 34.6% to 37.2% and 51.8% to 54.3% separately, respectively. The immobilization of DOX and MTX in combination onto MNP was 18% and 27%, respectively. HeLa and B cells were cultured with DOX-MNP, MTX-MNP, and DOX-MNP-MTX separately, and MagLISA indicated that the binding of DOX-MNP/MTX-MNP was 41.5% to 45% with HeLa cells and 20% to 26% with B cells. No significant difference was observed in binding of DOX-MNP-MTX with HeLa and B cells. Results also indicated that the release of medicines at pH 5.0 is more (39% to 44%) than at pH 7.4 (3.7% to 10.2%). Sixteen to 22% more killing effect was observed on HeLa cells than on B cells. In immunohistochemical staining, more deposition of brown color on HeLa cells than on B cells may be due to more expression of iron-binding sites on cancer cells. The dual property of MNP can be used for binding of medicines and for targeting drug delivery.

  9. Global Delivery Models

    DEFF Research Database (Denmark)

    Manning, Stephan; Larsen, Marcus M.; Bharati, Pratyush

    2013-01-01

    This article examines antecedents and performance implications of global delivery models (GDMs) in global business services. GDMs require geographically distributed operations to exploit both proximity to clients and time-zone spread for efficient service delivery. We propose and empirically show...... that service providers who differentiate based on speed of service delivery are likely to set up GDM structures, and that these structures positively affect deal renewal rates if speed is important for clients in selecting vendors. Findings imply that, as co-location becomes less necessary for providing...... digitalized services, time zones increasingly affect....

  10. Global Delivery Models

    DEFF Research Database (Denmark)

    Manning, Stephan; Møller Larsen, Marcus; Bharati, Pratyush

    We investigate antecedents and contingencies of location configurations supporting global delivery models (GDMs) in global outsourcing. GDMs are a new form of IT-enabled client-specific investment promoting services provision integration with clients by exploiting client proximity and time......-zone spread allowing for 24/7 service delivery and access to resources. Based on comprehensive data we show that providers are likely to establish GDM configurations when clients value access to globally distributed talent pools and speed of service delivery, and in particular when services are highly...

  11. Global Delivery Models

    DEFF Research Database (Denmark)

    Manning, Stephan; Møller Larsen, Marcus; Bharati, Pratyush

    We investigate antecedents and contingencies of location configurations supporting global delivery models (GDMs) in global outsourcing. GDMs are a new form of IT-enabled client-specific investment promoting services provision integration with clients by exploiting client proximity and time......-zone spread allowing for 24/7 service delivery and access to resources. Based on comprehensive data we show that providers are likely to establish GDM configurations when clients value access to globally distributed talent pools and speed of service delivery, and in particular when services are highly...... commoditized. Findings imply that coordination across time zones increasingly affects international operations in business-to-business and born-global industries....

  12. Focus on Delivery

    DEFF Research Database (Denmark)

    Hasman, Kirsten; Barfoed, Anne

    2016-01-01

    (2). It is, however, not clarified which of the multifaceted aspects of preventing perineal injury that might explain the decrease (3). Aims: We hypothesized that the use of structured reflection on a clinical practice by midwives and midwifery students would increase both parts’ knowledge on how...... attended a delivery. The tool was developed based on five categories: communication, pace, ergonomic positions, perineal support in the chosen birth position and delivery of the shoulders, and five predefined questions guided an overall reflection upon practice. After a delivery a project midwife, who had...

  13. SHP-1 phosphatase activity counteracts increased T cell receptor affinity.

    Science.gov (United States)

    Hebeisen, Michael; Baitsch, Lukas; Presotto, Danilo; Baumgaertner, Petra; Romero, Pedro; Michielin, Olivier; Speiser, Daniel E; Rufer, Nathalie

    2013-03-01

    Anti-self/tumor T cell function can be improved by increasing TCR-peptide MHC (pMHC) affinity within physiological limits, but paradoxically further increases (K(d) affinity for the tumor antigen HLA-A2/NY-ESO-1, we investigated the molecular mechanisms underlying this high-affinity-associated loss of function. As compared with cells expressing TCR affinities generating optimal function (K(d) = 5 to 1 μM), those with supraphysiological affinity (K(d) = 1 μM to 15 nM) showed impaired gene expression, signaling, and surface expression of activatory/costimulatory receptors. Preferential expression of the inhibitory receptor programmed cell death-1 (PD-1) was limited to T cells with the highest TCR affinity, correlating with full functional recovery upon PD-1 ligand 1 (PD-L1) blockade. In contrast, upregulation of the Src homology 2 domain-containing phosphatase 1 (SHP-1/PTPN6) was broad, with gradually enhanced expression in CD8(+) T cells with increasing TCR affinities. Consequently, pharmacological inhibition of SHP-1 with sodium stibogluconate augmented the function of all engineered T cells, and this correlated with the TCR affinity-dependent levels of SHP-1. These data highlight an unexpected and global role of SHP-1 in regulating CD8(+) T cell activation and responsiveness and support the development of therapies inhibiting protein tyrosine phosphatases to enhance T cell-mediated immunity.

  14. High affinity retinoic acid receptor antagonists: analogs of AGN 193109.

    Science.gov (United States)

    Johnson, A T; Wang, L; Gillett, S J; Chandraratna, R A

    1999-02-22

    A series of high affinity retinoic acid receptor (RAR) antagonists were prepared based upon the known antagonist AGN 193109 (2). Introduction of various phenyl groups revealed a preference for substitution at the para-position relative to the meta-site. Antagonists with the highest affinities for the RARs possessed hydrophobic groups, however, the presence of polar functionality was also well tolerated.

  15. Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators

    Science.gov (United States)

    Fields, Jessica; Copp, Martha

    2015-01-01

    Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…

  16. Ordinary matter in nonlinear affine gauge theories of gravitation

    CERN Document Server

    Tiemblo, A; Tiemblo, A; Tresguerres, R

    1994-01-01

    We present a general framework to include ordinary fermionic matter in the metric--affine gauge theories of gravity. It is based on a nonlinear gauge realization of the affine group, with the Lorentz group as the classification subgroup of the matter and gravitational fields.

  17. Isolation of bovine serum albumin from whey using affinity chromatography

    NARCIS (Netherlands)

    Besselink, T.; Janssen, A.E.M.; Boom, R.M.

    2015-01-01

    The adsorption of bovine serum albumin (BSA) to a chromatography resin with immobilised llama antibody fragments as affinity ligands was investigated. The maximum adsorption capacity of the affinity resin was 21.6 mg mL-1 with a Langmuir equilibrium constant of 20.4 mg mg-1. Using packed bed chromat

  18. Striving for Empathy: Affinities, Alliances and Peer Sexuality Educators

    Science.gov (United States)

    Fields, Jessica; Copp, Martha

    2015-01-01

    Peer sexuality educators' accounts of their work reveal two approaches to empathy with their students: affinity and alliance. "Affinity-based empathy" rests on the idea that the more commonalities sexuality educators and students share (or perceive they share), the more they will be able to empathise with one another, while…

  19. Convergence of generic infinite products of affine operators

    Directory of Open Access Journals (Sweden)

    S. Reich

    1999-01-01

    Full Text Available We establish several results concerning the asymptotic behavior of random infinite products of generic sequences of affine uniformly continuous operators on bounded closed convex subsets of a Banach space. In addition to weak ergodic theorems we also obtain convergence to a unique common fixed point and more generally, to an affine retraction.

  20. Gray-Scale Image Colorization Using Various Affinity Functions

    Directory of Open Access Journals (Sweden)

    Imron Rosyadi

    2012-02-01

    Full Text Available In this paper, we have proposed, implemented, and compared some affinity functions for an image colorization algorithm. The colorization qualityof the proposed affinityfunctions was just slightly behind the original functions, while one of the proposed functions performed faster than the original affinity function. We also implemented the colorization algorithm for coloring an Indonesian historical image.

  1. Affine group formulation of the Standard Model coupled to gravity

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Ching-Yi, E-mail: l2897107@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Taiwan (China); Ita, Eyo, E-mail: ita@usna.edu [Department of Physics, US Naval Academy, Annapolis, MD (United States); Soo, Chopin, E-mail: cpsoo@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Taiwan (China)

    2014-04-15

    In this work we apply the affine group formalism for four dimensional gravity of Lorentzian signature, which is based on Klauder’s affine algebraic program, to the formulation of the Hamiltonian constraint of the interaction of matter and all forces, including gravity with non-vanishing cosmological constant Λ, as an affine Lie algebra. We use the hermitian action of fermions coupled to gravitation and Yang–Mills theory to find the density weight one fermionic super-Hamiltonian constraint. This term, combined with the Yang–Mills and Higgs energy densities, are composed with York’s integrated time functional. The result, when combined with the imaginary part of the Chern–Simons functional Q, forms the affine commutation relation with the volume element V(x). Affine algebraic quantization of gravitation and matter on equal footing implies a fundamental uncertainty relation which is predicated upon a non-vanishing cosmological constant. -- Highlights: •Wheeler–DeWitt equation (WDW) quantized as affine algebra, realizing Klauder’s program. •WDW formulated for interaction of matter and all forces, including gravity, as affine algebra. •WDW features Hermitian generators in spite of fermionic content: Standard Model addressed. •Constructed a family of physical states for the full, coupled theory via affine coherent states. •Fundamental uncertainty relation, predicated on non-vanishing cosmological constant.

  2. Self-affine roughness influence on redox reaction charge admittance

    NARCIS (Netherlands)

    Palasantzas, G

    2005-01-01

    In this work we investigate the influence of self-affine electrode roughness on the admittance of redox reactions during facile charge transfer kinetics. The self-affine roughness is characterized by the rms roughness amplitude w, the correlation length xi and the roughness exponent H (0

  3. Frame-independent mechanics:geometry on affine bundles

    OpenAIRE

    Grabowska, K.; Grabowski, J.; Urbanski, P.

    2005-01-01

    Main ideas of the differential geometry on affine bundles are presented. Affine counterparts of Lie algebroid and Poisson structures are introduced and discussed. The developed concepts are applied in a frame-independent formulation of the time-dependent and the Newtonian mechanics.

  4. Synthesis of tetracycline analogs and their bone affinities

    Institute of Scientific and Technical Information of China (English)

    Wen Cai Huang; Hu Zheng; Ling Ling Weng

    2008-01-01

    Tetracycline analogs were designed and synthesized and their bone affinities were tested on hydroxyapatite. The results showedthat the carbonyl-amide-enol structure in A ring and phenol-ketone structure in BCD ring may be responsible for tetracycline's highbone affinity and either A ring or BCD ring has a planar conformation is essential.

  5. The Affine Complete Hypersurfaces of Constant Gauss-Kronecker Curvature

    Institute of Scientific and Technical Information of China (English)

    Bao Fu WANG

    2009-01-01

    Given a bounded convex domain Ω with C∞ boundary and a function φ∈ C∞ ( partial deriv Ω), Li-Simon-Chen can construct an Euclidean complete and W-complete convex hypersurface M with constant affine Gauss-Kronecker curvature, and they guess the M is also affine complete. In this paper, we give a confirmation answer.

  6. Germinal center reaction: antigen affinity and presentation explain it all.

    Science.gov (United States)

    Oropallo, Michael A; Cerutti, Andrea

    2014-07-01

    The selection and expansion of B cells undergoing affinity maturation in the germinal center is a hallmark of humoral immunity. A recent paper in Nature provides new insights into the relationships between the affinity of the immunoglobulin receptor for antigen, the ability of B cells to present antigen to T cells, and the processes of selection, mutation, and clonal expansion in the germinal center.

  7. Peptide Nucleic Acids Having Enhanced Binding Affinity and Sequence Specificity

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than a corresponding DNA strand, and exhibit increased sequence specificity and binding affinity. Methods of increasing binding affinity and sequence specificity of peptide nucleic aci...

  8. Downstream processing of polysaccharide degrading enzymes by affinity chromatography.

    NARCIS (Netherlands)

    Somers, W.A.C.

    1992-01-01

    The objective of this study was the development of affinity matrices to isolate and purify a number of polysaccharide degrading enzymes and the application of these adsorbents in the large- scale purification of the enzymes from fermentation broths. Affinity adsorbents were developed for endo-polyga

  9. [Separation anxiety in children].

    Science.gov (United States)

    Purper-Ouakil, Diane; Franc, Nathalie

    2010-06-20

    Separation anxiety disorder can be differentiated from developmental anxiety because of its intensity, persistence and negative impact on adaptive functioning. This disorder is closely linked to other anxiety and mood disorders and can also be associated with externalizing psychopathology in children and adolescents. Severe separation anxiety can result in school refusal and intra-familial violence. Cognitive behavioral therapies have the best evidence-based support for the treatment of separation anxiety disorder in children and adolescents. In addition, it is important to detect factors associated with persistence of anxiety such as systematic avoidance of separation and parental overprotection. The role of pediatricians and general practitioners in recognizing clinical separation anxiety and encouraging appropriate care and positive parental attitudes is essential, as separation anxiety is often associated with a variety of somatic symptoms.

  10. [Separation anxiety. Theoretical considerations].

    Science.gov (United States)

    Blandin, N; Parquet, P J; Bailly, D

    1994-01-01

    The interest in separation anxiety is nowadays increasing: this disorder appearing during childhood may predispose to the occurrence of anxiety disorders (such as panic disorder and agoraphobia) and major depression into adulthood. Psychoanalytic theories differ on the nature of separation anxiety and its place in child development. For some authors, separation anxiety must be understood as resulting from the unconscious internal conflicts inherent in the individuation process and gradual attainment of autonomy. From this point of view, the fear of loss of mother by separation is not regarded as resulting from a real danger. However, Freud considers the primary experience of separation from protecting mother as the prototype situation of anxiety and compares the situations generating fear to separation experiences. For him, anxiety originates from two factors: the physiological fact is initiated at the time of birth but the primary traumatic situation is the separation from mother. This point of view may be compared with behavioral theories. Behavioral theories suggest that separation anxiety may be conditioned or learned from innate fears. In Freud's theory, the primary situation of anxiety resulting from the separation from mother plays a role comparable to innate fears. Grappling with the problem of separation anxiety, Bowlby emphasizes then the importance of the child's attachment to one person (mother or primary caregiver) and the fact that this attachment is instinctive. This point of view, based on the watch of infants, is akin to ethological theories on behaviour of non human primates. Bowlby especially shows that the reactions of infant separated from mother evolve on three stages: the phase of protestation which may constitute the prototype of adulthood anxiety, the phase of desperation which may be the prototype of depression, and the phase of detachment. He emphasizes so the role of early separations in the development of vulnerability to depression

  11. Volatility Components, Affine Restrictions and Non-Normal Innovations

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Dorian, Christian

    Recent work by Engle and Lee (1999) shows that allowing for long-run and short-run components greatly enhances a GARCH model's ability fit daily equity return dynamics. Using the risk-neutralization in Duan (1995), we assess the option valuation performance of the Engle-Lee model and compare...... it to the standard one-component GARCH(1,1) model. We also compare these non-affine GARCH models to one- and two- component models from the class of affine GARCH models developed in Heston and Nandi (2000). Using the option pricing methodology in Duan (1999), we then compare the four conditionally normal GARCH...... models to four conditionally non-normal versions. As in Hsieh and Ritchken (2005), we find that non-affine models dominate affine models both in terms of fitting return and in terms of option valuation. For the affine models we find strong evidence in favor of the component structure for both returns...

  12. IMPLEMENTASI ENKRIPSI DEKRIPSI ALGORITMA AFFINE CIPHER BERBASIS ANDROID

    Directory of Open Access Journals (Sweden)

    Sasono Wibowo

    2014-11-01

    Full Text Available Perkembangan Teknologi Informasi yang cukup pesat khususnya dalam bidang komunikasi menjadikan komunikasi sangat mudah namun dalam implementasinya perlu adanya keamanan tentang informasi yang disampaikan. Dalam komunikasi antar orang pasti memiliki pembicaraan informasi yang bersifat privat atau orang lain tidak boleh tahu tentang pembicaraan yang terjadi. Diperlukannya keamanan untuk menjaga kerahasiaan informasi pada saat komunikasi. Masyarakat lebih sering menggunakan komunikasi dengan telepon seluler karena dinilai mudah dibawa dan tidak repot menggunakannya. Kriptografi yang biasa dikenal sebagai ilmu yang mempelajari bagaimana cara menyembunyikan pesan bisa diterapkan dalam aplikasi pada telepon seluler sebagai contoh smartphone android. Dengan mengimplementasikan algoritma affine cipher maka aplikasi yang akan dibuat bisa mengubah isi pesan yang ada dan dapat mengamankan informasi yang ada. Algoritma affine cipher merupakan perkembangan dari algoritma caesar dimana algoritma affine cipher menggunakan dua kunci. Dengan mengimplementasikan algoritma affine cipher ke dalam android maka diharapkan kita bisa menyimpan informasi dari siapapun tanpa terbaca. Kata Kunci : Kriptografi, Affine Cipher, android, Implementasi, Informasi

  13. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  14. Isolation, identification and characterisation of starch-interacting proteins by 2-D affinity electrophoresis.

    Science.gov (United States)

    Kosar-Hashemi, Behjat; Irwin, Jennifer A; Higgins, Jody; Rahman, Sadequr; Morell, Matthew K

    2006-05-01

    A 2-D affinity electrophoretic technique (2-DAE) has been used to isolate proteins that interact with various starch components from total barley endosperm extracts. In the first dimension, proteins are separated by native PAGE. The second-dimensional gel contains polysaccharides such as amylopectin and glycogen. The migration of starch-interacting proteins in this dimension is determined by their affinity towards a particular polysaccharide and these proteins are therefore spatially separated from the bulk of proteins in the crude extract. Four distinct proteins demonstrate significant affinity for amylopectin and have been identified as starch branching enzyme I (SBEI), starch branching enzyme IIa (SBEIIa), SBEIIb and starch phosphorylase using polyclonal antibodies and zymogram activity analysis. In the case of starch phosphorylase, a protein spot was excised from a 2-DAE polyacrylamide gel and analysed using Q-TOF MS/MS, resulting in the alignment of three internal peptide sequences with the known sequence of the wheat plastidic starch phosphorylase isoform. This assignment was confirmed by the determination of the enzyme's function using zymogram analysis. Dissociation constants (Kd) were calculated for the three enzymes at 4 degrees C and values of 0.20, 0.21 and 1.3 g/L were determined for SBEI, SBEIIa and starch phosphorylase, respectively. Starch synthase I could also be resolved from the other proteins in the presence of glycogen and its identity was confirmed using a polyclonal antibody and by activity analysis. The 2-DAE method described here is simple, though powerful, enabling protein separation from crude extracts on the basis of function.

  15. Chasing polys: Interdisciplinary affinity and its connection to physics identity

    Science.gov (United States)

    Scott, Tyler D.

    This research is based on two motivations that merge by means of the frameworks of interdisciplinary affinity and physics identity. First, a goal of education is to develop interdisciplinary abilities in students' thinking and work. But an often ignored factor is students interests and beliefs about being interdisciplinary. Thus, this work develops and uses a framework called interdisciplinary affinity. It encompasses students interests in making connections across disciplines and their beliefs about their abilities to make those connections. The second motivation of this research is to better understand how to engage more students with physics. Physics identity describes how a student sees themselves in relation to physics. By understanding how physics identity is developed, researchers and educators can identify factors that increase interest and engagement in physics classrooms. Therefore, physics identity was used in conjunction with interdisciplinary affinity. Using a mixed methods approach, this research used quantitative data to identify the relationships interdisciplinary affinity has with physics identity and the physics classroom. These connections were explored in more detail using a case study of three students in a high school physics class. Results showed significant and positive relationships between interdisciplinary affinity and physics identity, including the individual interest and recognition components of identity. It also identified characteristics of physics classrooms that had a significant, positive relationship with interdisciplinary affinity. The qualitative case study highlighted the importance of student interest to the relationship between interdisciplinary affinity and physics identity. It also identified interest and mastery orientation as key to understanding the link between interdisciplinary affinity and the physics classroom. These results are a positive sign that by understanding interdisciplinary affinity and physics identity

  16. Transdermal delivery of proteins.

    Science.gov (United States)

    Kalluri, Haripriya; Banga, Ajay K

    2011-03-01

    Transdermal delivery of peptides and proteins avoids the disadvantages associated with the invasive parenteral route of administration and other alternative routes such as the pulmonary and nasal routes. Since proteins have a large size and are hydrophilic in nature, they cannot permeate passively across the skin due to the stratum corneum which allows the transport of only small lipophilic drug molecules. Enhancement techniques such as chemical enhancers, iontophoresis, microneedles, electroporation, sonophoresis, thermal ablation, laser ablation, radiofrequency ablation and noninvasive jet injectors aid in the delivery of proteins by overcoming the skin barrier in different ways. In this review, these enhancement techniques that can enable the transdermal delivery of proteins are discussed, including a discussion of mechanisms, sterility requirements, and commercial development of products. Combination of enhancement techniques may result in a synergistic effect allowing increased protein delivery and these are also discussed.

  17. The separation of adult separation anxiety disorder.

    Science.gov (United States)

    Baldwin, David S; Gordon, Robert; Abelli, Marianna; Pini, Stefano

    2016-08-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) categorization of mental disorders places "separation anxiety disorder" within the broad group of anxiety disorders, and its diagnosis no longer rests on establishing an onset during childhood or adolescence. In previous editions of DSM, it was included within the disorders usually first diagnosed in infancy, childhood, or adolescence, with the requirement for an onset of symptoms before the age of 18 years: symptomatic adults could only receive a retrospective diagnosis, based on establishing this early onset. The new position of separation anxiety disorder is based upon the findings of epidemiological studies that revealed the unexpectedly high prevalence of the condition in adults, often in individuals with an onset of symptoms after the teenage years; its prominent place within the DSM-5 group of anxiety disorders should encourage further research into its epidemiology, etiology, and treatment. This review examines the clinical features and boundaries of the condition, and offers guidance on how it can be distinguished from other anxiety disorders and other mental disorders in which "separation anxiety" may be apparent.

  18. Optimal affine-invariant matching: performance characterization

    Science.gov (United States)

    Costa, Mauro S.; Haralick, Robert M.; Shapiro, Linda G.

    1992-04-01

    The geometric hashing scheme proposed by Lamdan and Wolfson can be very efficient in a model-based matching system, not only in terms of the computational complexity involved, but also in terms of the simplicity of the method. In a recent paper, we discussed errors that can occur with this method due to quantization, stability, symmetry, and noise problems. These errors make the original geometric hashing technique unsuitable for use on the factory floor. Beginning with an explicit noise model, which the original Lamdan and Wolfson technique lacks, we derived an optimal approach that overcomes these problems. We showed that the results obtained with the new algorithm are clearly better than the results from the original method. This paper addresses the performance characterization of the geometric hashing technique, more specifically the affine-invariant point matching, applied to the problem of recognizing and determining the pose of sheet metal parts. The experiments indicate that with a model having 10 to 14 points, with 2 points of the model undetected and 10 extraneous points detected, and with the model points perturbed by Gaussian noise of standard deviation 3 (0.58 of range), the average amount of computation required to obtain an answer is equivalent to trying 11 of the possible three-point bases. The misdetection rate, measured by the percentage of correct bases matches that fail to verify, is 0.9. The percentage of incorrect bases that successfully produced a match that did verify (false alarm rate) is 13. And, finally, 2 of the experiments failed to find a correct match and verify it. Results for experiments with real images are also presented.

  19. Affinity capillary electrophoresis: the theory of electromigration.

    Science.gov (United States)

    Dubský, Pavel; Dvořák, Martin; Ansorge, Martin

    2016-12-01

    We focus on the state-of-the-art theory of electromigration under single and multiple complexation equilibrium. Only 1:1 complexation stoichiometry is discussed because of its unique status in the field of affinity capillary electrophoresis (ACE). First, we summarize the formulas for the effective mobility in various ACE systems as they appeared since the pioneering days in 1992 up to the most recent theories till 2015. Disturbing phenomena that do not alter the mobility of the analyte directly but cause an unexpected peak broadening have been studied only recently and are also discussed in this paper. Second, we turn our attention to the viscosity effects in ACE. Change in the background electrolyte viscosity is unavoidable in ACE but numerous observations scattered throughout the literature have not been reviewed previously. This leads to an uncritical employment of correction factors that may or may not be appropriate in practice. Finally, we consider the ionic strength effects in ACE, too. Limitations of the current theories are also discussed and the tasks identified where open problems still prevail. Graphical Abstract A weak base (A) undergoes an acidic-basic equilibria (in blue) and migrates with an electrophoretic mobility of [Formula: see text]. Simultaneously, it interacts with a selector (sel) while the analyte-selector complex migrates with an electrophoretic mobility of [Formula: see text]. The strength of the interaction (in orange) is governed by the binding constant, K A , and the concentration of the selector, c sel . This all gives the analyte an effective mobility of [Formula: see text] and moves it out of the zero position (EOF; right top insert). The interaction of the positively charged analyte with the neutral selector slows down the analyte with increasing selector concentration (right bottom insert).

  20. Electrochemical Affinity Biosensors in Food Safety

    Directory of Open Access Journals (Sweden)

    Susana Campuzano

    2017-02-01

    Full Text Available Safety and quality are key issues of today’s food industry. Since the food chain is becoming more and more complex, powerful analytical methods are required to verify the performance of food safety and quality systems. Indeed, such methods require high sensitivity, selectivity, ability for rapid implementation and capability of automatic screening. Electroanalytical chemistry has, for decades, played a relevant role in food safety and quality assessment, taking more and more significance over time in the solution of analytical problems. At present, the implementation of electrochemical methods in the food is evident. This is in a large part due to the relevant results obtained by combining the attractive advantages of electrochemical transduction strategies (in terms of relatively simple hardware, versatility, interface with automatic logging and feasibility of application outside the laboratory environment with those from biosensors technology. Important examples of enzyme electrochemical biosensors are those dedicated to the determination of glucose, alcohol or cholesterol are important examples. In addition, other types of different electrochemical biosensing approaches have emerged strongly in the last years. Among these, the strategies involving affinity interactions have been shown to possess a large number of applications. Therefore, electrochemical immunosensors and DNA-based biosensors have been widely used to determine major and minor components in foodstuffs, providing sufficient data to evaluate food freshness, the quality of raw materials, or the origin of samples, as well as to determine a variety of compounds at trace levels related to food safety such as micotoxins, allergens, drugs residues or pathogen microorganisms. This review discusses some critical examples of the latest advances in this area, pointing out relevant methodologies related to the measurement techniques, including the use of nanostructured electrodes and

  1. Convulsant bicuculline modifies CNS muscarinic receptor affinity

    Directory of Open Access Journals (Sweden)

    Rodríguez de Lores Arnaiz Georgina

    2006-04-01

    Full Text Available Abstract Background Previous work from this laboratory has shown that the administration of the convulsant drug 3-mercaptopropionic acid (MP, a GAD inhibitor, modifies not only GABA synthesis but also binding of the antagonist [3H]-quinuclidinyl benzilate ([3H]-QNB to central muscarinic receptors, an effect due to an increase in affinity without modifications in binding site number. The cholinergic system has been implicated in several experimental epilepsy models and the ability of acetylcholine to regulate neuronal excitability in the neocortex is well known. To study the potential relationship between GABAergic and cholinergic systems with seizure activity, we analyzed the muscarinic receptor after inducing seizure by bicuculline (BIC, known to antagonize the GABA-A postsynaptic receptor subtype. Results We analyzed binding of muscarinic antagonist [3H]-QNB to rat CNS membranes after i.p. administration of BIC at subconvulsant (1.0 mg/kg and convulsant (7.5 mg/kg doses. Subconvulsant BIC dose failed to develop seizures but produced binding alteration in the cerebellum and hippocampus with roughly 40% increase and 10% decrease, respectively. After convulsant BIC dose, which invariably led to generalized tonic-clonic seizures, binding increased 36% and 15% to cerebellar and striatal membranes respectively, but decreased 12% to hippocampal membranes. Kd value was accordingly modified: with the subconvulsant dose it decreased 27% in cerebellum whereas it increased 61% in hippocampus; with the convulsant dose, Kd value decreased 33% in cerebellum but increased 85% in hippocampus. No change in receptor number site was found, and Hill number was invariably close to unity. Conclusion Results indicate dissimilar central nervous system area susceptibility of muscarinic receptor to BIC. Ligand binding was modified not only by a convulsant BIC dose but also by a subconvulsant dose, indicating that changes are not attributable to the seizure process

  2. MUCOSAL DRUG DELIVERY SYSTEM

    OpenAIRE

    Madan Jyotsana; Banode Sagar; Dangi Mahesh

    2010-01-01

    The process of mucoadhesion involving a polymeric drug delivery system is a complex one that includes processes such as wetting, adsorption and interpenetration of polymer chains. The success and degree of mucoadhesion bonding is influenced by various polymer-based properties such as the degree of cross-linking, chain length and the presence of various functional groupings. The attractiveness of mucosal-targeted controlled drug delivery of active pharmaceutical ingredients, has led formulatio...

  3. Molecularly Imprinted Polymers with Stimuli-Responsive Affinity: Progress and Perspectives

    OpenAIRE

    Wei Chen; Yue Ma; Jianmin Pan; Zihui Meng; Guoqing Pan; Börje Sellergren

    2015-01-01

    Intelligent stimuli-responsive molecularly imprinted polymers (SR-MIPs) have attracted considerable research interest in recent years due to the potential applications in drug delivery, biotechnology and separation sciences. This review comprehensively summarizes various SR-MIPs, including the design and applications of thermo-responsive MIPs, pH-responsive MIPs, photo-responsive MIPs, biomolecule-responsive MIPs and ion-responsive MIPs. Besides the development of current SR-MIPs, the advanta...

  4. Working with Separation

    Science.gov (United States)

    Krugman, Dorothy C.

    1971-01-01

    Discusses the role of the caseworker in providing support to children experiencing separation from their families and emphasizes the need to recognize that there are differences between those separation experiences dictated by the needs of children and those dictated by arbitrary or noncasework factors. (AJ)

  5. Separation anxiety disorder

    NARCIS (Netherlands)

    Nauta, M.H.; Emmelkamp, P.M.G.; Sturmey, P.; Hersen, M.

    2012-01-01

    Separation anxiety disorder (SAD) is the only anxiety disorder that is specific to childhood; however, SAD has hardly ever been addressed as a separate disorder in clinical trials investigating treatment outcome. So far, only parent training has been developed specifically for SAD. This particular t

  6. Social Separation in Monkeys.

    Science.gov (United States)

    Mineka, Susan; Suomi, Stephen J.

    1978-01-01

    Reviews phenomena associated with social separation from attachment objects in nonhuman primates. Evaluates four theoretical treatments of separation in light of existing data: Bowlby's attachment-object-loss theory, Kaufman's conservation-withdrawal theory, Seligman's learned helplessness theory, and Solomon and Corbit's opponent-process theory.…

  7. Nonterminal Separating Macro Grammars

    NARCIS (Netherlands)

    Hogendorp, Jan Anne; Asveld, P.R.J.; Nijholt, A.; Verbeek, Leo A.M.

    1987-01-01

    We extend the concept of nonterminal separating (or NTS) context-free grammar to nonterminal separating $m$-macro grammar where the mode of derivation $m$ is equal to "unrestricted". "outside-in' or "inside-out". Then we show some (partial) characterization results for these NTS $m$-macro grammars.

  8. Spiral microfluidic nanoparticle separators

    Science.gov (United States)

    Bhagat, Ali Asgar S.; Kuntaegowdanahalli, Sathyakumar S.; Dionysiou, Dionysios D.; Papautsky, Ian

    2008-02-01

    Nanoparticles have potential applications in many areas such as consumer products, health care, electronics, energy and other industries. As the use of nanoparticles in manufacturing increases, we anticipate a growing need to detect and measure particles of nanometer scale dimensions in fluids to control emissions of possible toxic nanoparticles. At present most particle separation techniques are based on membrane assisted filtering schemes. Unfortunately their efficiency is limited by the membrane pore size, making them inefficient for separating a wide range of sizes. In this paper, we propose a passive spiral microfluidic geometry for momentum-based particle separations. The proposed design is versatile and is capable of separating particulate mixtures over a wide dynamic range and we expect it will enable a variety of environmental, medical, or manufacturing applications that involve rapid separation of nanoparticles in real-world samples with a wide range of particle components.

  9. Dosimetric verification of RapidArc treatment delivery

    DEFF Research Database (Denmark)

    Korreman, Stine; Medin, Joakim; Kjaer-Kristoffersen, Flemming

    2009-01-01

    doses. All plans were then delivered several times to verify consistency of the delivery. Gamma analysis was used to verify the correspondence between dose distributions. The temporal resolution of the delivery was analysed by investigating the arc segments between control points separately. RESULTS......: Overall, good agreement was observed between measured and calculated doses in most cases with gamma values above 1 in >95% of measured points. The reproducibility of delivery was also very high. Gamma analysis between two consecutive runs of the same delivery plan generally showed gamma values above 1......PURPOSE: Recently, Varian Medical Systems have announced the introduction of a new treatment technique, in which dose is delivered over a single gantry rotation with variable MLC positions, dose rate and gantry speed. In February 2008, a preclinical installation of the RapidArc beam delivery...

  10. Large Scale Magnetic Separation of Solanum tuberosum Tuber Lectin from Potato Starch Waste Water

    Science.gov (United States)

    Safarik, Ivo; Horska, Katerina; Martinez, Lluis M.; Safarikova, Mirka

    2010-12-01

    A simple procedure for large scale isolation of Solanum tuberosum tuber lectin from potato starch industry waste water has been developed. The procedure employed magnetic chitosan microparticles as an affinity adsorbent. Magnetic separation was performed in a flow-through magnetic separation system. The adsorbed lectin was eluted with glycine/HCl buffer, pH 2.2. The specific activity of separated lectin increased approximately 27 times during the isolation process.

  11. Development of an epoxy-based monolith used for the affinity capturing of Escherichia coli bacteria.

    Science.gov (United States)

    Peskoller, Caroline; Niessner, Reinhard; Seidel, Michael

    2009-05-01

    An epoxy-based monolith has been developed for use as hydrophilic support in bioseparation. This monolith is produced by self-polymerization of polyglycerol-3-glycidyl ether in organic solvents as porogens at room temperature within 1 h. One receives a highly cross-linked structure that provides useful mechanical properties. The porosity and pore diameter can be controlled by varying the composition of the porogen. In this work, an epoxy-based monolith with a high porosity (79%) and large pore size (22 microm) is prepared and used in affinity capturing of bacterial cells. These features allow the passage of bacterial cells through the column. As affinity ligand polymyxin B is used, which allows the binding of gram-negative bacteria. The efficiency of the monolithic affinity column is studied with Escherichia coli spiked in water. Bacterial cells are concentrated on the column at pH 4 and eluted with a recovery of 97+/-3% in 200 microL by changing the pH value without impairing viability of bacteria. The dynamic capacity for the monolithic column is nearly independent of the flow rate (4x10(9)cells/column). Thereby, it is possible to separate and enrich gram-negative bacterial cells, such as E. coli, with high flow rates (10 mL/min) and low back pressure (<1 bar) in a volume as low as 200 microL compatible for real-time polymerase chain reaction, microarray formats, and biosensors.

  12. Differential interactions of plasmid DNA, RNA and genomic DNA with amino acid-based affinity matrices.

    Science.gov (United States)

    Sousa, Angela; Sousa, Fani; Queiroz, João A

    2010-09-01

    The development of a strategy to plasmid DNA (pDNA) purification has become necessary for the development of gene therapy and DNA vaccine production processes in recent years, since this nucleic acid and most of contaminants, such as RNA, genomic DNA and endotoxins, are negatively charged. An ideal separation methodology may be achieved with the use of affinity interactions between immobilized amino acids and nucleic acids. In this study, the binding behaviour of nucleic acids under the influence of different environmental conditions, such as the composition and ionic strength of elution buffer, and the temperature, is compared with various amino acids immobilized on chromatography resins. Supercoiled (sc) plasmid isoform was isolated with all matrices used, but in some cases preferential interactions with other nucleic acids were found. Particularly, lysine chromatography showed to be an ideal technology mainly on RNA purification using low salt concentration. On the other hand, arginine ligands have shown a greater ability to retain the sc isoform comparatively to the other nucleic acids retention, becoming this support more adequate to sc pDNA purification. The temperature variation, competitive elution and oligonucleotides affinity studies also allowed to recognize the dominant interactions inherent to biorecognition of pDNA molecule and the affinity matrices.

  13. Comparative Study of Three Methods for Affinity Measurements: Capillary Electrophoresis Coupled with UV Detection and Mass Spectrometry, and Direct Infusion Mass Spectrometry

    Science.gov (United States)

    Mironov, Gleb G.; Logie, Jennifer; Okhonin, Victor; Renaud, Justin B.; Mayer, Paul M.; Berezovski, Maxim V.

    2012-07-01

    We present affinity capillary electrophoresis and mass spectrometry (ACE-MS) as a comprehensive separation technique for label-free solution-based affinity analysis. The application of ACE-MS for measuring affinity constants between eight small molecule drugs [ibuprofen, s-flurbiprofen, diclofenac, phenylbutazone, naproxen, folic acid, resveratrol, and 4,4'-(propane-1,3-diyl) dibenzoic acid] and β-cyclodextrin is described. We couple on-line ACE with MS to combine the separation and kinetic capability of ACE together with the molecular weight and structural elucidation of MS in one system. To understand the full potential of ACE-MS, we compare it with two other methods: Direct infusion mass spectrometry (DIMS) and ACE with UV detection (ACE-UV). After the evaluation, DIMS provides less reliable equilibrium dissociation constants than separation-based ACE-UV and ACE-MS, and cannot be used solely for the study of noncovalent interactions. ACE-MS determines apparent dissociation constants for all reacting small molecules in a mixture, even in cases when drugs overlap with each other during separation. The ability of ACE-MS to interact, separate, and rapidly scan through m/z can facilitate the simultaneous affinity analysis of multiple interacting pairs, potentially leading to the high-throughput screening of drug candidates.

  14. Purification of Mycobacterium bovis BCG Tokyo antigens by chromatofocusing, lectin-affinity chromatography, and hydrophobic interaction chromatography.

    Science.gov (United States)

    Sugden, E A; Stilwell, K; Watson, D C; Rohonczy, E B; Martineau, P

    1996-09-01

    A combination of chromatofocusing, lectin-affinity chromatography, and hydrophobic interaction chromatography resulted in a simple purification of protein antigens of Mycobacterium bovis BCG Tokyo culture filtrate. Identification was established on the basis of chromatographic separation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis determination of molecular weights, and N-terminal amino acid determination. Chromatofocusing on PBE 94 accomplished the separation of BCG85B from other BCG85 complex antigens and partial separation of MPB64 and MPB70 antigens. Subsequently, MPB64 and MPB70 were completely separated on a high-performance liquid chromatography TSK Phenyl 5PW hydrophobic interaction chromatography column. This column also separated BCG85B from a 17-kDa protein with an N-terminal amino acid sequence of A-V-P-I-T-G-K-L-G-S-E-L-T-M-T-D-( )-V-G-Q, which is similar to the sequence of MPT63. Concanavalin A-Sepharose-affinity chromatography separated MPB64 from a 43- and 47-kDa doublet with an amino acid sequence of D-P-E-P-A-P-P-V-P-P-V-P-A-( )-A-A-S-P, which is similar to the sequence of MPT32 and which appears to be glycosylated.

  15. The sodium ion affinities of asparagine, glutamine, histidine and arginine

    Science.gov (United States)

    Wang, Ping; Ohanessian, Gilles; Wesdemiotis, Chrys

    2008-01-01

    The sodium ion affinities of the amino acids Asn, Gln, His and Arg have been determined by experimental and computational approaches (for Asn, His and Arg). Na+-bound heterodimers with amino acid and peptide ligands (Pep1, Pep2) were produced by electrospray ionization. From the dissociation kinetics of these Pep1-Na+-Pep2 ions to Pep1-Na+ and Pep2-Na+, determined by collisionally activated dissociation, a ladder of relative affinities was constructed and subsequently converted to absolute affinities by anchoring the relative values to known Na+ affinities. The Na+ affinities of Asn, His and Arg, were calculated at the MP2(full)/6-311+G(2d,2p)//MP2/6-31G(d) level of ab initio theory. The resulting experimental and computed Na+ affinities are in excellent agreement with one another. These results, combined with those of our previous studies, yield the sodium ion affinities of 18 out of the 20 [alpha]-amino acids naturally occurring in peptides and proteins of living systems.

  16. Tetrahydroprotoberberine alkaloids with dopamine and σ receptor affinity.

    Science.gov (United States)

    Gadhiya, Satishkumar; Madapa, Sudharshan; Kurtzman, Thomas; Alberts, Ian L; Ramsey, Steven; Pillarsetty, Nagavara-Kishore; Kalidindi, Teja; Harding, Wayne W

    2016-05-01

    Two series of analogues of the tetrahydroprotoberberine (THPB) alkaloid (±)-stepholidine that (a) contain various alkoxy substituents at the C10 position and, (b) were de-rigidified with respect to (±)-stepholidine, were synthesized and evaluated for affinity at dopamine and σ receptors in order to evaluate effects on D3 and σ2 receptor affinity and selectivity. Small n-alkoxy groups are best tolerated by D3 and σ2 receptors. Among all compounds tested, C10 methoxy and ethoxy analogues (10 and 11 respectively) displayed the highest affinity for σ2 receptors as well as σ2 versus σ1 selectivity and also showed the highest D3 receptor affinity. De-rigidification of stepholidine resulted in decreased affinity at all receptors evaluated; thus the tetracyclic THPB framework is advantageous for affinity at dopamine and σ receptors. Docking of the C10 analogues at the D3 receptor, suggest that an ionic interaction between the protonated nitrogen atom and Asp110, a H-bond interaction between the C2 phenol and Ser192, a H-bond interaction between the C10 phenol and Cys181 as well as hydrophobic interactions of the aryl rings to Phe106 and Phe345, are critical for high affinity of the compounds.

  17. Genetic Algorithm-based Affine Parameter Estimation for Shape Recognition

    Directory of Open Access Journals (Sweden)

    Yuxing Mao

    2014-06-01

    Full Text Available Shape recognition is a classically difficult problem because of the affine transformation between two shapes. The current study proposes an affine parameter estimation method for shape recognition based on a genetic algorithm (GA. The contributions of this study are focused on the extraction of affine-invariant features, the individual encoding scheme, and the fitness function construction policy for a GA. First, the affine-invariant characteristics of the centroid distance ratios (CDRs of any two opposite contour points to the barycentre are analysed. Using different intervals along the azimuth angle, the different numbers of CDRs of two candidate shapes are computed as representations of the shapes, respectively. Then, the CDRs are selected based on predesigned affine parameters to construct the fitness function. After that, a GA is used to search for the affine parameters with optimal matching between candidate shapes, which serve as actual descriptions of the affine transformation between the shapes. Finally, the CDRs are resampled based on the estimated parameters to evaluate the similarity of the shapes for classification. The experimental results demonstrate the robust performance of the proposed method in shape recognition with translation, scaling, rotation and distortion.

  18. Awareness and perceptions of Turkish women towards delivery methods

    Directory of Open Access Journals (Sweden)

    Şükrü Yıldız

    2014-06-01

    Full Text Available Objective: Our aim is to identify the causes of the women’s preferences of vaginal delivery vs. cesarean section and their attitudes for an elective cesarean section. Methods: 400 healthy woman who had applied for antenatal care were included in the study. A questionnaire which is consisted of 21 questions, focused on preference toward mode of delivery and the etiology of these preferences was conducted as a face to face interview. According to history of delivery methods, women have separated into three groups as; women have never given birth/nulliparous (group 1, women who had only vaginal deliveries (group 2, and women who had at least one cesarean deliveries/previous cesarean section (group 3. Results: Of the 400 women questioned, 348 (%87 opted for vaginal delivery, whereas only 52 (%13 opted for an elective caesarean delivery. Ratios of cesarean delivery preference is high in group 3 (%47.5 than group 1( %26 and 2 (%2.7 . Main reasons for vaginal delivery preference: feeling of less pain, fast and easy recovery and less bleeding and infection risc for mothers were the most common preference reasons among all 3 groups. The most common reasons for choosing caesarean delivery were: ‘more comfortable and easy’ in group 1 and ‘tubal ligation demand’ in group 3. ‘Less pain’ and ‘fear of tearing (episiotomy’ also other common reasons for choosing cesarean delivery among all 3 groups. Conclusion: In order to reduce the rate of implemented cesarean section, it is substantially important to encourage educated women and those who have experienced advanced maternal age for increasing the rate of vaginal delivery. J Clin Exp Invest 2014; 5 (2: 173-178

  19. Dispersing and Separating Carbon Nanotubes with Novel Surfactant Formulations

    Science.gov (United States)

    2010-08-01

    regions in the outer region of the complex. Following DGU, the buoyant density of the separated SWNTs is measured directly, and the SWNT chirality ...bioimaging, and drug delivery. Results and Discussion DGU-based separations of arc discharge grown SWNTs were performed with Pluronic block...17 Specific Chiralities Using Helical Assemblies of Flavin Mononucleotide. Nature Nanotech. 2008, 3, 356-362. 23. Green, A. A.; Hersam, M. C

  20. Affinity Thresholds for Membrane Fusion Triggering by Viral Glycoproteins▿

    OpenAIRE

    Hasegawa, Kosei; Hu, Chunling; Nakamura, Takafumi; Marks, James D.; Russell, Stephen J.; Peng, Kah-Whye

    2007-01-01

    Enveloped viruses trigger membrane fusion to gain entry into cells. The receptor affinities of their attachment proteins vary greatly, from 10−4 M to 10−9 M, but the significance of this is unknown. Using six retargeted measles viruses that bind to Her-2/neu with a 5-log range in affinity, we show that receptor affinity has little impact on viral attachment but is nevertheless a key determinant of infectivity and intercellular fusion. For a given cell surface receptor density, there is an aff...

  1. Volatility Components, Affine Restrictions and Non-Normal Innovations

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Dorian, Christian;

    Recent work by Engle and Lee (1999) shows that allowing for long-run and short-run components greatly enhances a GARCH model's ability fit daily equity return dynamics. Using the risk-neutralization in Duan (1995), we assess the option valuation performance of the Engle-Lee model and compare...... models to four conditionally non-normal versions. As in Hsieh and Ritchken (2005), we find that non-affine models dominate affine models both in terms of fitting return and in terms of option valuation. For the affine models we find strong evidence in favor of the component structure for both returns...

  2. Notes on affine isometric actions of discrete groups

    CERN Document Server

    Neretin, Yu A

    1997-01-01

    Consider a lattice $\\Gamma$ in a group $G = SL_2(\\R), SO(1,n), SU(1,n)$, $SL_2(\\Q_p)$. We discuss actions of $\\Gamma$ by affine isometric transformations of Hilbert spaces. We show that for irreducible affine isometric action of $G$ its restriction to $\\Gamma$ is irreducible. We prove the existence of canonical irreducible affine isometric actions of $\\Gamma$ associated to actions of $\\Gamma$ on $\\R$- trees. Using such actions we construct irreducible representations of semigroup of probabilistic measures on diffeomorphisms of Riemann surfaces enumerated by the points of Thurston compactification of Teichmüller (Teichmuller) space.

  3. Moment-Based Method to Estimate Image Affine Transform

    Institute of Scientific and Technical Information of China (English)

    FENG Guo-rui; JIANG Ling-ge

    2005-01-01

    The estimation of affine transform is a crucial problem in the image recognition field. This paper resorted to some invariant properties under translation, rotation and scaling, and proposed a simple method to estimate the affine transform kernel of the two-dimensional gray image. Maps, applying to the original, produce some correlative points that can accurately reflect the affine transform feature of the image. Furthermore, unknown variables existing in the kernel of the transform are calculated. The whole scheme only refers to one-order moment,therefore, it has very good stability.

  4. Affine structures and a tableau model for E_6 crystals

    CERN Document Server

    Jones, Brant

    2009-01-01

    We provide the unique affine crystal structure for type E_6^{(1)} Kirillov-Reshetikhin crystals corresponding to the multiples of fundamental weights s Lambda_1, s Lambda_2, and s Lambda_6 for all s \\geq 1 (in Bourbaki's labeling of the Dynkin nodes, where 2 is the adjoint node). Our methods introduce a generalized tableaux model for classical highest weight crystals of type E and use the order three automorphism of the affine E_6^{(1)} Dynkin diagram. In addition, we provide a conjecture for the affine crystal structure of type E_7^{(1)} Kirillov-Reshetikhin crystals corresponding to the adjoint node.

  5. ODE/IM correspondence and modified affine Toda field equations

    CERN Document Server

    Ito, Katsushi

    2014-01-01

    We study the two-dimensional affine Toda field equations for affine Lie algebra $\\hat{\\mathfrak{g}}$ modified by a conformal transformation and the associated linear equations. In the conformal limit, the associated linear problem reduces to a (pseudo-)differential equation. For classical affine Lie algebra $\\hat{\\mathfrak{g}}$, we obtain a (pseudo-)differential equation corresponding to the Bethe equations for the Langlands dual of the Lie algebra $\\mathfrak{g}$, which were found by Dorey et al. in study of the ODE/IM correspondence.

  6. An improved affine projection algorithm for active noise cancellation

    Science.gov (United States)

    Zhang, Congyan; Wang, Mingjiang; Han, Yufei; Sun, Yunzhuo

    2017-08-01

    Affine projection algorithm is a signal reuse algorithm, and it has a good convergence rate compared to other traditional adaptive filtering algorithm. There are two factors that affect the performance of the algorithm, which are step factor and the projection length. In the paper, we propose a new variable step size affine projection algorithm (VSS-APA). It dynamically changes the step size according to certain rules, so that it can get smaller steady-state error and faster convergence speed. Simulation results can prove that its performance is superior to the traditional affine projection algorithm and in the active noise control (ANC) applications, the new algorithm can get very good results.

  7. Calculating protein-ligand binding affinities with MMPBSA: Method and error analysis.

    Science.gov (United States)

    Wang, Changhao; Nguyen, Peter H; Pham, Kevin; Huynh, Danielle; Le, Thanh-Binh Nancy; Wang, Hongli; Ren, Pengyu; Luo, Ray

    2016-10-15

    Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) methods have become widely adopted in estimating protein-ligand binding affinities due to their efficiency and high correlation with experiment. Here different computational alternatives were investigated to assess their impact to the agreement of MMPBSA calculations with experiment. Seven receptor families with both high-quality crystal structures and binding affinities were selected. First the performance of nonpolar solvation models was studied and it was found that the modern approach that separately models hydrophobic and dispersion interactions dramatically reduces RMSD's of computed relative binding affinities. The numerical setup of the Poisson-Boltzmann methods was analyzed next. The data shows that the impact of grid spacing to the quality of MMPBSA calculations is small: the numerical error at the grid spacing of 0.5 Å is already small enough to be negligible. The impact of different atomic radius sets and different molecular surface definitions was further analyzed and weak influences were found on the agreement with experiment. The influence of solute dielectric constant was also analyzed: a higher dielectric constant generally improves the overall agreement with experiment, especially for highly charged binding pockets. The data also showed that the converged simulations caused slight reduction in the agreement with experiment. Finally the direction of estimating absolute binding free energies was briefly explored. Upon correction of the binding-induced rearrangement free energy and the binding entropy lost, the errors in absolute binding affinities were also reduced dramatically when the modern nonpolar solvent model was used, although further developments were apparently necessary to further improve the MMPBSA methods. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Cooperative binding of LysM domains determines the carbohydrate affinity of a bacterial endopeptidase protein.

    Science.gov (United States)

    Wong, Jaslyn E M M; Alsarraf, Husam M A B; Kaspersen, Jørn Døvling; Pedersen, Jan Skov; Stougaard, Jens; Thirup, Søren; Blaise, Mickaël

    2014-02-01

    Cellulose, chitin and peptidoglycan are major long-chain carbohydrates in living organisms, and constitute a substantial fraction of the biomass. Characterization of the biochemical basis of dynamic changes and degradation of these β,1-4-linked carbohydrates is therefore important for both functional studies of biological polymers and biotechnology. Here, we investigated the functional role of multiplicity of the carbohydrate-binding lysin motif (LysM) domain that is found in proteins involved in bacterial peptidoglycan synthesis and remodelling. The Bacillus subtilis peptidoglycan-hydrolysing NlpC/P60 D,L-endopeptidase, cell wall-lytic enzyme associated with cell separation, possesses four LysM domains. The contribution of each LysM domain was determined by direct carbohydrate-binding studies in aqueous solution with microscale thermophoresis. We found that bacterial LysM domains have affinity for N-acetylglucosamine (GlcNac) polymers in the lower-micromolar range. Moreover, we demonstrated that a single LysM domain is able to bind carbohydrate ligands, and that LysM domains act additively to increase the binding affinity. Our study reveals that affinity for GlcNAc polymers correlates with the chain length of the carbohydrate, and suggests that binding of long carbohydrates is mediated by LysM domain cooperativity. We also show that bacterial LysM domains, in contrast to plant LysM domains, do not discriminate between GlcNAc polymers, and recognize both peptidoglycan fragments and chitin polymers with similar affinity. Finally, an Ala replacement study suggested that the carbohydrate-binding site in LysM-containing proteins is conserved across phyla. © 2013 FEBS.

  9. Mannosylerythritol lipid, a yeast extracellular glycolipid, shows high binding affinity towards human immunoglobulin G

    Directory of Open Access Journals (Sweden)

    Ikegami Toru

    2001-09-01

    Full Text Available Abstract Background There have been many attempts to develop new materials with stability and high affinity towards immunoglobulins. Some of glycolipids such as gangliosides exhibit a high affinity toward immunoglobulins. However, it is considerably difficult to develop these glycolipids into the practical separation ligand due to their limited amounts. We thus focused our attention on the feasible use of "mannosylerythritol lipid A", a yeast glycolipid biosurfactant, as an alternative ligand for immunoglobulins, and undertook the investigation on the binding between mannosylerythritol lipid A (MEL-A and human immunoglobulin G (HIgG. Results In ELISA assay, MEL-A showed nearly the same binding affinity towards HIgG as that of bovine ganglioside GM1. Fab of human IgG was considered to play a more important role than Fc in the binding of HIgG by MEL-A. The bound amount of HIgG increased depending on the attached amount of MEL-A onto poly (2-hydroxyethyl methacrylate (polyHEMA beads, whereas the amount of human serum albumin slightly decreased. Binding-amount and -selectivity of HIgG towards MEL-A were influenced by salt species, salt concentration and pH in the buffer solution. The composite of MEL-A and polyHEMA, exhibited a significant binding constant of 1.43 × 106 (M-1 for HIgG, which is approximately 4-fold greater than that of protein A reported. Conclusions MEL-A shows high binding-affinity towards HIgG, and this is considered to be due to "multivalent effect" based on the binding molar ratio. This is the first report on the binding of a natural human antibody towards a yeast glycolipid.

  10. Improving Network Performance with Affinity based Mobility Model in Opportunistic Network

    CERN Document Server

    Batabyal, Suvadip; 10.5121/ijwmn.2012.4213

    2012-01-01

    Opportunistic network is a type of Delay Tolerant Network which is characterized by intermittent connectivity amongst the nodes and communication largely depends upon the mobility of the participating nodes. The network being highly dynamic, traditional MANET protocols cannot be applied and the nodes must adhere to store-carry-forward mechanism. Nodes do not have the information about the network topology, number of participating nodes and the location of the destination node. Hence, message transfer reliability largely depends upon the mobility pattern of the nodes. In this paper we have tried to find the impact of RWP (Random Waypoint) mobility on packet delivery ratio. We estimate mobility factors like number of node encounters, contact duration(link time) and inter-contact time which in turn depends upon parameters like playfield area (total network area), number of nodes, node velocity, bit-rate and RF range of the nodes. We also propose a restricted form of RWP mobility model, called the affinity based ...

  11. Affine Riesz bases and the dual function

    Science.gov (United States)

    Terekhin, P. A.

    2016-09-01

    This paper is concerned with systems of functions on the unit interval which are generated by dyadic dilations and integer translations of a given function. Similar systems have a wide range of applications in the theory of wavelets, in nonlinear, and in particular, in greedy approximations, in the representation of functions by series, in problems in numerical analysis, and so on. Conditions, and in some particular cases, criteria for the generating function are given for the system to be Besselian, to form a Riesz basis or to be an orthonormal system, and separately, to be complete. For this purpose, the concept of the dual function of the generating function of a system is introduced and studied. Some of the conditions given below are easy to verify in practice, as is demonstrated by examples. Bibliography: 25 titles.

  12. Radiochemical separation of Cobalt

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    A method is described for the radiochemical separation of cobalt based on the extraordinary stability of cobalt diethyldithiocarbamate. Interferences are few; only very small amounts of zinc and iron accompany cobalt, which is important in neutron-activation analysis.

  13. On Separate Universes

    CERN Document Server

    Dai, Liang; Schmidt, Fabian

    2015-01-01

    The separate universe conjecture states that in General Relativity a density perturbation behaves locally (i.e. on scales much smaller than the wavelength of the mode) as a separate universe with different background density and curvature. We prove this conjecture for a spherical compensated tophat density perturbation of arbitrary amplitude and radius in $\\Lambda$CDM. We then use Conformal Fermi Coordinates to generalize this result to scalar perturbations of arbitrary configuration and scale in a general cosmology with a mixture of fluids, but to linear order in perturbations. In this case, the separate universe conjecture holds for the isotropic part of the perturbations. The anisotropic part on the other hand is exactly captured by a tidal field in the Newtonian form. We show that the separate universe picture is restricted to scales larger than the sound horizons of all fluid components. We then derive an expression for the locally measured matter bispectrum induced by a long-wavelength mode of arbitrary...

  14. Electroextraction separation of dyestuffs

    Energy Technology Data Exchange (ETDEWEB)

    Luo, G.S.; Yu, M.J.; Jiang, W.B.; Zhu, S.L.; Dai, Y.Y. [Tsinghua Univ., Beijing (China). Dept. of Chemical Engineering

    1999-03-01

    Electroseparation technologies have prospects for significant growth well into the next century. Electroextraction, a coupled separation technique of solvent extraction with electrophoresis, was used to remove dyestuffs from their aqueous stream. A study on the characteristics of the separation technique was carried out with n-butanol/acid-chrom blue K/water and n-butanol/methyl blue/water as working systems. A continuous separation equipment was designed and sued in this work. The influences of two-phase flow, field strength, and concentration of the feed on the recovery of solute were studied. The results showed that much higher recovery of solute with less solvent consumption could be achieved by using this technique to remove dyes from their aqueous streams, especially for the separation of the dilute solution. When the field strength is increased, the recovery and mass flux increase. When the feed flow rate and the initial solute concentration are increased, the recovery decreases and the mass flux increases.

  15. Shoulder separation - aftercare

    Science.gov (United States)

    ... and top of your shoulder blade A severe shoulder separation You may need surgery right away if you have: Numbness in your fingers Cold fingers Muscle weakness in your arm Severe deformity of the joint

  16. Radiochemical separation of Cobalt

    NARCIS (Netherlands)

    Erkelens, P.C. van

    1961-01-01

    A method is described for the radiochemical separation of cobalt based on the extraordinary stability of cobalt diethyldithiocarbamate. Interferences are few; only very small amounts of zinc and iron accompany cobalt, which is important in neutron-activation analysis.

  17. Safe Separators for Treewidth

    NARCIS (Netherlands)

    Bodlaender, H.L.; Koster, A.M.C.A.

    2003-01-01

    A set of vertices S Í V is called a safe separator for treewidth, if S is a separator of G, and the treewidth of G equals the maximum of the treewidth over all connected components W of G - S of the graph, obtained by making S a clique in the subgraph of G, induced by W È S. We show that such safe s

  18. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  19. Separation techniques: Chromatography

    OpenAIRE

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorp...

  20. Distal humeral epiphyseal separation.

    Science.gov (United States)

    Moucha, Calin S; Mason, Dan E

    2003-10-01

    Distal humeral epiphyseal separation is an uncommon injury that is often misdiagnosed upon initial presentation. To make a timely, correct diagnosis, the treating physician must have a thorough understanding of basic anatomical relationships and an awareness of the existence of this injury. This is a case of a child who sustained a separation of the distal humeral epiphysis, as well as multiple other bony injuries, secondary to child abuse.

  1. Affinity (tropism) of caprine arthritis encephalitis virus for brain cells ...

    African Journals Online (AJOL)

    Affinity (tropism) of caprine arthritis encephalitis virus for brain cells. ... chain reaction (RTPCR) and transmission electron microscopy (TEM techniques). ... CAE virus infection of goat brain cells to that of HIV infection in humans thus suggesting ...

  2. Elective affinities and economic thought: 1870-1914

    Directory of Open Access Journals (Sweden)

    João Antônio de Paula

    2006-01-01

    Full Text Available This article seeks to demonstrate that the concept of "elective affinities" can be applied to the relations between economic thought, literature, and philosophy. Emphasis is given to Institutionalist thought, the German historical school, and neoclassical thought.

  3. ASIFT: An Algorithm for Fully Affine Invariant Comparison

    Directory of Open Access Journals (Sweden)

    Guoshen Yu

    2011-02-01

    Full Text Available If a physical object has a smooth or piecewise smooth boundary, its images obtained by cameras in varying positions undergo smooth apparent deformations. These deformations are locally well approximated by affine transforms of the image plane. In consequence the solid object recognition problem has often been led back to the computation of affine invariant image local features. The similarity invariance (invariance to translation, rotation, and zoom is dealt with rigorously by the SIFT method The method illustrated and demonstrated in this work, Affine-SIFT (ASIFT, simulates a set of sample views of the initial images, obtainable by varying the two camera axis orientation parameters, namely the latitude and the longitude angles, which are not treated by the SIFT method. Then it applies the SIFT method itself to all images thus generated. Thus, ASIFT covers effectively all six parameters of the affine transform.

  4. Dirac equation in gauge and affine-metric gravitation theories

    CERN Document Server

    Giachetta, G

    1995-01-01

    We show that the covariant derivative of Dirac fermion fields in the presence of a general linear connection on a world manifold is universal for Einstein's, gauge and affine-metric gravitation theories.

  5. REFINABLE DISTRIBUTIONS SUPPORTED ON SELF-AFFINE TILES

    Institute of Scientific and Technical Information of China (English)

    DaiXinrong

    2002-01-01

    In this paper,some conditions which assure the compactly supported refinable distributions supported on a self-affine tile to be Lebesgue-Stieltjes measures or absolutely continuous measures with respect to Lebesgue-Stieltjes measures are given.

  6. A thermodynamic approach to the affinity optimization of drug candidates.

    Science.gov (United States)

    Freire, Ernesto

    2009-11-01

    High throughput screening and other techniques commonly used to identify lead candidates for drug development usually yield compounds with binding affinities to their intended targets in the mid-micromolar range. The affinity of these molecules needs to be improved by several orders of magnitude before they become viable drug candidates. Traditionally, this task has been accomplished by establishing structure activity relationships to guide chemical modifications and improve the binding affinity of the compounds. As the binding affinity is a function of two quantities, the binding enthalpy and the binding entropy, it is evident that a more efficient optimization would be accomplished if both quantities were considered and improved simultaneously. Here, an optimization algorithm based upon enthalpic and entropic information generated by Isothermal Titration Calorimetry is presented.

  7. Taking Advantage: High Affinity B cells in the Germinal Center Have Lower Death Rates, But Similar Rates of Division Compared to Low Affinity Cells1

    OpenAIRE

    2009-01-01

    B lymphocytes producing high affinity antibodies (Abs) are critical for protection from extracellular pathogens, such as bacteria and parasites. The process by which high affinity B cells are selected during the immune response has never been elucidated. Though it has been shown that high affinity cells directly outcompete low affinity cells in the germinal center (GC)2, whether there are also intrinsic differences between these cells has not been addressed. It could be that higher affinity c...

  8. Affine A(1)3 N = 2 Monopole as the D Module and Affine ADHMN Sheaf

    Institute of Scientific and Technical Information of China (English)

    SONG Xiao-Shu; HOU Bo-Yu; GUO Yun-Dong; HOU Bo-Yuan; LING-HU Rong-Feng; L(U) Bing; CHENG Xin-Lu; YANG Xiang-Dong

    2008-01-01

    A Higgs-Yang-Mills monopole scattering spherical symmetrically Mong light cones is given. The left incoming anti-self-dual α plane fields are holomorphic, but the right outgoing SD fl plane fields are antiholomorphic, meanwhile the diffeomorphism symmetry is preserved with mutual inverse a/fine rapidity parameters μ and μ-1. The Dirac wave function scattering in this background also factorized respectively into the (anti)holomorphic amplitudes. The holomorphic anomaly is realized by the center term of a quasi Hopf algebra corresponding to an integrable conformal a/fine massive field. We find explicit Nahm transformation matrix (Fourier-Mukai transformation) between the Higgs YM BPS (fiat) bundles (D modules) and the affinized blow up ADHMN twistors (perverse sheafs). Thus we establish the algebra for the 't Hooft Hecke operators in the Hecke correspondence of the geometric Langfands program.

  9. A new affinity approach to isolate Escherichia coli 6S RNA with histidine-chromatography.

    Science.gov (United States)

    Martins, R; Queiroz, J A; Sousa, F

    2010-01-01

    6S RNA is an abundant non-coding RNA in Escherichia coli (E. coli), but its function has not been discovered until recently. The first advance on 6S RNA function was the demonstration of its ability to bind the σ(70)-holoenzyme form of RNA polymerase, inhibiting its activity and consequently the transcription process. The growing interest in the investigation of non-coding small RNAs (sRNA) calls for the development of new methods for isolation and purification of RNA. This work presents an optimized RNA extraction procedure and describes a new affinity chromatography method using a histidine support to specifically purify 6S RNA from other E. coli sRNA species. The RNA extraction procedure was optimized, and a high yield was obtained in the separation of sRNA and ribosomal RNA (rRNA) from total RNA (RNAt). This improved method takes advantage of its simplicity and significant cost reduction, since some complex operations have been eliminated. A purification strategy was also developed to separate 6S RNA from an sRNA mixture. Pure RNA can be advantageously obtained using the histidine-affinity chromatography method, aiming at its application to structural or functional studies.

  10. Specific recognition of supercoiled plasmid DNA by affinity chromatography using the intercalator DAPP as ligand.

    Science.gov (United States)

    Caramelo-Nunes, C; Almeida, P; Marcos, J C; Tomaz, C T

    2013-06-01

    Small molecules that bind DNA with high specificity present a promising opportunity for application as chromatographic ligands for plasmid DNA (pDNA) purification. This research used the intercalator 3,8-diamino-6-phenylphenanthridine (DAPP) as an immobilized ligand for the specific separation of supercoiled (sc) pDNA by affinity chromatography. The results showed that the protonated DAPP-Sepharose support has a great affinity for sc pDNA isoform, separating it from the less active open circular and linear isoforms. All pDNA isoforms were retained in the column using 10mM acetate buffer pH 5. Selective elution of oc and linear isoforms was achieved with 0.22M of sodium chloride in the same buffer. Finally, increasing the concentration to 0.55M led to the elution of the sc isoform. The binding of pDNA to DAPP-Sepharose varies in function of pH, and the stability of the protonated DAPP-DNA complex decreases with increasing salt concentration. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Genetic affinities of Helicobacter pylori isolates from ethnic Arabs in Kuwait

    Directory of Open Access Journals (Sweden)

    Albert M John

    2010-07-01

    Full Text Available Abstract Helicobacter pylori is one of the most genetically diverse of bacterial species, and since the 5'-end of cagA gene and the middle allele of vacA gene of H. pylori from different populations exhibit considerable polymorphisms, these sequence diversities were used to gain insights into the genetic affinities of this gastric pathogen from different populations. Because the genetic affinity of Arab strains from the Arabian Gulf is not known, we carried out genetic analysis based on sequence diversities of the cagA and the vacA genes of H. pylori from 9 ethnic Arabs in Kuwait. The analysis showed that the Kuwaiti isolates are closely related to the Indo-European group of strains, although some strains have a tendency to form a separate cluster close to the Indo- European group, but clearly distinct from East Asian strains. However, these results need to be confirmed by analyses of neutral markers (house-keeping genes in a multi-locus sequence typing [MLST] platform. The profiling of virulence-associated genes may have resulted from ecologically distinct populations due to human migration and geographical separation over long periods of time.

  12. Density Gradient Ultracentrifugation to Isolate Endogenous Protein Complexes after Affinity Capture.

    Science.gov (United States)

    Fernandez-Martinez, Javier; LaCava, John; Rout, Michael P

    2016-07-01

    This protocol describes the isolation of native protein complexes by density gradient ultracentrifugation. The outcome of an affinity capture and native elution experiment is generally a mixture of (1) the complex(es) associated with the protein of interest under the specific conditions of capture, (2) fragments of the complex generated by degradation or disassembly during the purification procedure, and (3) the protease or reagent used to natively elute the sample. To separate these components and isolate a homogeneous complex, an additional step of purification is required. Rate-zonal density gradient ultracentrifugation is a reliable and powerful technique for separating particles based on their hydrodynamic volume. The density gradient is generated by mixing low- and high-density solutions of a suitable low-molecular-weight inert solute (e.g., sucrose or glycerol). The gradient is formed in a solvent that could be any of the solvents used for the affinity capture and native elution and should help to preserve the structure and activity of the assembly.

  13. Affinity purification of sequence-specific DNA binding proteins.

    OpenAIRE

    1986-01-01

    We describe a method for affinity purification of sequence-specific DNA binding proteins that is fast and effective. Complementary chemically synthesized oligodeoxynucleotides that contain a recognition site for a sequence-specific DNA binding protein are annealed and ligated to give oligomers. This DNA is then covalently coupled to Sepharose CL-2B with cyanogen bromide to yield the affinity resin. A partially purified protein fraction is combined with competitor DNA and subsequently passed t...

  14. Some Inequalities for Lp-mixed Affine Surface Area

    Institute of Scientific and Technical Information of China (English)

    ZHU Xian-yang

    2012-01-01

    In this paper,the concepts of the ith Lp-mixed affine surface area and Lp-polar curvature images are introduced,some new inequalities connecting these new notions with Lp-centroid bodies and p-Blaschke bodies are showed.Moreover,a Blaschke-Santaló type inequality for Lp-mixed affine surface area is established.Our results also imply the similar to the inequalities for Marcus-Lopes,Bergstrom and Ky Fan.

  15. Implementasi Kombinasi Caesar dan Affine Cipher untuk Keamanan Data Teks

    Directory of Open Access Journals (Sweden)

    Dian Rachmawati

    2015-11-01

    Full Text Available Petukaran data yang terjadi secara offline maupunonline sangat rentan dengan ancaman pencurian data. KombinasiCaesar dan Affine Cipher diharapkan mampu untuk menanganiisu keamanan data. Caesar Cipher bekerja denganmemanfaatkan pergeseran atau dikenal dengan shift ciphersementara Affine Cipher bekerja dengan menggunakan kunci duabuah bilangan integer. Kombinasi dua buah algoritma ini mampumengamankan data dan mengembalikan kembali ke bentukaslinya (plainteks, sehingga tidak menyebabkan integritasdatanya hilang. Kata Kunci—plainteks, cipherteks, Caesar cipher, Affinecipher.

  16. Global Delivery Models

    DEFF Research Database (Denmark)

    Manning, Stephan; Møller Larsen, Marcus; Bharati, Pratyush M.

    2015-01-01

    Global delivery models (GDMs) are transforming the global IT and business process outsourcing industry. GDMs are a new form of client-specific investment promoting service integration with clients by combining client proximity with time-zone spread for 24/7 service operations. We investigate...... antecedents and contingencies of setting up GDM structures. Based on comprehensive data we show that providers are likely to establish GDM location configurations when clients value access to globally distributed talent and speed of service delivery, in particular when services are highly commoditized...

  17. Ethical issues in cesarean delivery.

    Science.gov (United States)

    Chervenak, Frank A; McCullough, Laurence B

    2017-08-01

    Cesarean delivery is the most common and important surgical intervention in obstetric practice. Ethics provides essential guidance to obstetricians for offering, recommending, recommending against, and performing cesarean delivery. This chapter provides an ethical framework based on the professional responsibility model of obstetric ethics. This framework is then used to address two especially ethically challenging clinical topics in cesarean delivery: patient-choice cesarean delivery and trial of labor after cesarean delivery. This chapter emphasizes a preventive ethics approach, designed to prevent ethical conflict in clinical practice. To achieve this goal, a preventive ethics approach uses the informed consent process to offer cesarean delivery as a medically reasonable alternative to vaginal delivery, to recommend cesarean delivery, and to recommend against cesarean delivery. The limited role of shared decision making is also described. The professional responsibility model of obstetric ethics guides this multi-faceted preventive ethics approach. Copyright © 2017. Published by Elsevier Ltd.

  18. High affinity ligands for 'diazepam-insensitive' benzodiazepine receptors.

    Science.gov (United States)

    Wong, G; Skolnick, P

    1992-01-14

    Structurally diverse compounds have been shown to possess high affinities for benzodiazepine receptors in their 'diazepam-sensitive' (DS) conformations. In contrast, only the imidazobenzodiazepinone Ro 15-4513 has been shown to exhibit a high affinity for the 'diazepam-insensitive' (DI) conformation of benzodiazepine receptors. We examined a series of 1,4-diazepines containing one or more annelated ring systems for their affinities at DI and DS benzodiazepine receptors, several 1,4-diazepinone carboxylates including Ro 19-4603, Ro 16-6028 and Ro 15-3505 were found to possess high affinities (Ki approximately 2.6-20 nM) for DI. Nonetheless, among the ligands examined, Ro 15-4513 was the only substance with a DI/DS potency ratio approximately 1; other substances had ratios ranging from 13 to greater than 1000. Ligands with high to moderate affinities at DI were previously classified as partial agonists, antagonists, or partial inverse agonists at DS benzodiazepine receptors, but behaved as 'GABA neutral' (antagonist) substances at DI. The identification of several additional high affinity ligands at DI benzodiazepine receptors may be helpful in elucidating the pharmacological and physiological importance of these sites.

  19. Magnetic DNA affinity purification of yeast transcription factor tau--a new purification principle for the ultrarapid isolation of near homogeneous factor.

    OpenAIRE

    1989-01-01

    We present a new method for rapid purification to near homogeneity of sequence specific DNA binding proteins based on magnetic separation. The method is described for the purification of the yeast transcription factor tau. DNA affinity Dynabeads (monodisperse superparamagnetic particles) specifically bind the protein in the presence of competitor DNA. By magnetic separation, wash and elution, highly enriched transcription factor preparations are obtained within minutes. In less than an hour w...

  20. Gulf stream separation dynamics

    Science.gov (United States)

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  1. Separably injective Banach spaces

    CERN Document Server

    Avilés, Antonio; Castillo, Jesús M F; González, Manuel; Moreno, Yolanda

    2016-01-01

    This monograph contains a detailed exposition of the up-to-date theory of separably injective spaces: new and old results are put into perspective with concrete examples (such as l∞/c0 and C(K) spaces, where K is a finite height compact space or an F-space, ultrapowers of L∞ spaces and spaces of universal disposition). It is no exaggeration to say that the theory of separably injective Banach spaces is strikingly different from that of injective spaces. For instance, separably injective Banach spaces are not necessarily isometric to, or complemented subspaces of, spaces of continuous functions on a compact space. Moreover, in contrast to the scarcity of examples and general results concerning injective spaces, we know of many different types of separably injective spaces and there is a rich theory around them. The monograph is completed with a preparatory chapter on injective spaces, a chapter on higher cardinal versions of separable injectivity and a lively discussion of open problems and further lines o...

  2. [Complications of cesarean deliveries].

    Science.gov (United States)

    Valgeirsdottir, Heiddis; Hardardottir, Hildur; Bjarnadottir, Ragnheidur I

    2010-01-01

    The objective of the study was to determine the rate of complications which accompany cesarean sections at Landspitali University Hospital (LSH). All deliveries by cesarean section from July 1st 2001 to December 31st 2002 were examined in a retrospective manner. Information was collected from maternity records regarding the operation and its complications if they occurred, during or following the operation. During this period 761 women delivered by cesarean section at LSH. The overall complication rate was 35,5%. The most common complications were; blood loss > or =1000 ml (16.5%), post operative fever (12.2%), extension from the uterine incision (7.2%) and need for blood transfusion (4.3%). Blood transfusion was most common in women undergoing cesarean section after attempted instrumental vaginal delivery (20%). Fever and extension from the uterine incision were most common in women undergoing cesarean section after full cervical dilation without attempt of instrumental delivery (19,4%). These complications were least likely to occur if the patient underwent an elective cesarean section. Complications following cesarean section are common, especially if labor is advanced. Each indication for an operative delivery should be carefully weighed and the patient informed accordingly.

  3. A Medical Delivery Device

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a medical delivery device comprising at least two membrane electrode assembly units each of which comprises three layers: an upper and a lower electrode and a selective ionic conductive membrane provided there-between. At least one of the three layers are shared...

  4. Recovering from Delivery

    Science.gov (United States)

    ... suicidal thoughts, or any thoughts of harming your baby While recovering from delivery can be a lot to handle, things will get easier. Before you know it, you will be able to fully focus on enjoying your new baby. Reviewed by: Larissa Hirsch, MD Date reviewed: June ...

  5. A Medical Delivery Device

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a medical delivery device comprising at least two membrane electrode assembly units each of which comprises three layers: an upper and a lower electrode and a selective ionic conductive membrane provided there-between. At least one of the three layers are shared...

  6. Macrophage mannose receptor-specific gene delivery vehicle for macrophage engineering.

    Science.gov (United States)

    Ruan, Gui-Xin; Chen, Yu-Zhe; Yao, Xing-Lei; Du, Anariwa; Tang, Gu-Ping; Shen, You-Qing; Tabata, Yasuhiko; Gao, Jian-Qing

    2014-05-01

    Macrophages are the most plastic cells in the hematopoietic system and they exhibit great functional diversity. They have been extensively applied in anti-inflammatory, anti-fibrotic and anti-cancer therapies. However, the application of macrophages is limited by the efficiency of their engineering. The macrophage mannose receptor (MMR, CD206), a C-type lectin receptor, is ubiquitously expressed on macrophages and has a high affinity for mannose oligosaccharides. In the present study, we developed a novel non-viral vehicle with specific affinity for MMR. Mannan was cationized with spermine at a grafted ratio of ∼12% to deliver DNA and was characterized as a stable system for delivery. This spermine-mannan (SM)-based delivery system was evaluated as a biocompatible vehicle with superior transfection efficiency on murine macrophages, up to 28.5-fold higher than spermine-pullulan, 11.5-fold higher than polyethylenimine and 3.0-fold higher than Lipofectamine™ 2000. We confirmed that the SM-based delivery system for macrophages transfection was MMR-specific and we described the intracellular transport of the delivery system. To our knowledge, this is the first study using SM to demonstrate a mannose receptor-specific gene delivery system, thereby highlighting the potential of a novel specific non-viral delivery vehicle for macrophage engineering.

  7. Mass Separation by Metamaterials.

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-25

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  8. Phaco slice and separate.

    Science.gov (United States)

    Arshinoff, S A

    1999-04-01

    Phaco slice and separate retains the advantages of the chopping techniques of Nagahara, Koch, and Fukasaku but replaces chopping or snapping with slicing across the center of the phaco-tip-stabilized nucleus using a Nagahara chopper and then repositioning the chopper to optimally separate the divided lens halves. As the lens is rotated in the capsular bag, small pieces of the nuclear pie are sliced off, separated, emulsified, and aspirated. Emulsification and aspiration can alternatively be left until most or all the slices have been made. This technique works with a broader range of lens densities than other chopping techniques and uses no sculpting and very little phaco time. The phaco time required for this technique is relatively independent of nuclear density compared with a sculpting technique.

  9. Membrane separation of hydrocarbons

    Science.gov (United States)

    Chang, Y. Alice; Kulkarni, Sudhir S.; Funk, Edward W.

    1986-01-01

    Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture through a polymeric membrane. The membrane which is utilized to effect the separation comprises a polymer which is capable of maintaining its integrity in the presence of hydrocarbon compounds and which has been modified by being subjected to the action of a sulfonating agent. Sulfonating agents which may be employed will include fuming sulfuric acid, chlorosulfonic acid, sulfur trioxide, etc., the surface or bulk modified polymer will contain a degree of sulfonation ranging from about 15 to about 50%. The separation process is effected at temperatures ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psig.

  10. Self-nanoemulsifying drug delivery systems for oral insulin delivery

    DEFF Research Database (Denmark)

    Li, Ping; Tan, Angel; Prestidge, Clive A

    2014-01-01

    This study aims at evaluating the combination of self-nanoemulsifying drug delivery systems (SNEDDS) and enteric-coated capsules as a potential delivery strategy for oral delivery of insulin. The SNEDDS preconcentrates, loaded with insulin-phospholipid complex at different levels (0, 2.5 and 10% w...

  11. Gas separation membranes

    Science.gov (United States)

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

  12. Separation membrane development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  13. Separation techniques: Chromatography

    Science.gov (United States)

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  14. Learning Isometric Separation Maps

    CERN Document Server

    Vasiloglou, Nikolaos; Anderson, David V

    2008-01-01

    Maximum Variance Unfolding (MVU) and its variants have been very successful in embedding data-manifolds in lower dimensionality spaces, often revealing the true intrinsic dimensions. In this paper we show how to also incorporate supervised class information into an MVU-like method without breaking its convexity. We call this method the Isometric Separation Map and we show that the resulting kernel matrix can be used for a binary/multiclass Support Vector Machine in a semi-supervised (transductive) framework. We also show that the method always finds a kernel matrix that linearly separates the training data exactly without projecting them in infinite dimensional spaces.

  15. Separators for electrochemical cells

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley

    2014-11-11

    Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Preferably, the inorganic oxide comprises an hydrated aluminum oxide of the formula Al.sub.2O.sub.3.xH.sub.2O, wherein x is less than 1.0, and wherein the hydrated aluminum oxide comprises organic substituents, preferably comprising a reaction product of a multifunctional monomer and/or organic carbonate with an aluminum oxide, such as pseudo-boehmite and an aluminum oxide. Also provided are electrochemical cells comprising such separators.

  16. Supervised Machine Learning Methods Applied to Predict Ligand- Binding Affinity.

    Science.gov (United States)

    Heck, Gabriela S; Pintro, Val O; Pereira, Richard R; de Ávila, Mauricio B; Levin, Nayara M B; de Azevedo, Walter F

    2017-01-01

    Calculation of ligand-binding affinity is an open problem in computational medicinal chemistry. The ability to computationally predict affinities has a beneficial impact in the early stages of drug development, since it allows a mathematical model to assess protein-ligand interactions. Due to the availability of structural and binding information, machine learning methods have been applied to generate scoring functions with good predictive power. Our goal here is to review recent developments in the application of machine learning methods to predict ligand-binding affinity. We focus our review on the application of computational methods to predict binding affinity for protein targets. In addition, we also describe the major available databases for experimental binding constants and protein structures. Furthermore, we explain the most successful methods to evaluate the predictive power of scoring functions. Association of structural information with ligand-binding affinity makes it possible to generate scoring functions targeted to a specific biological system. Through regression analysis, this data can be used as a base to generate mathematical models to predict ligandbinding affinities, such as inhibition constant, dissociation constant and binding energy. Experimental biophysical techniques were able to determine the structures of over 120,000 macromolecules. Considering also the evolution of binding affinity information, we may say that we have a promising scenario for development of scoring functions, making use of machine learning techniques. Recent developments in this area indicate that building scoring functions targeted to the biological systems of interest shows superior predictive performance, when compared with other approaches. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Moderate Exercise Increases Affinity of Large Very Low-Density Lipoproteins for Hydrolysis by Lipoprotein Lipase.

    Science.gov (United States)

    Ghafouri, Khloud; Cooney, Josephine; Bedford, Dorothy K; Wilson, John; Caslake, Muriel J; Gill, Jason M R

    2015-06-01

    Postprandial triglyceride (TG) concentration is independently associated with cardiovascular disease risk. Exercise reduces postprandial TG concentrations, but the mechanisms responsible are unclear. The objective was to determine the effects of exercise on affinity of chylomicrons, large very low-density lipoproteins (VLDL1), and smaller VLDL (VLDL2) for lipoprotein lipase (LPL)-mediated TG hydrolysis. This was designed as a within-participant crossover study. The setting was a university metabolic investigation unit. Participants were 10 overweight/obese men. Participants undertook two oral fat tolerance tests, separated by 7-14 days, in which they had blood taken while fasting and for 4 hours after a high-fat mixed meal. On the afternoon before one test, they performed a 90-minute treadmill walk at 50% maximal oxygen uptake (exercise trial [EX]); no exercise was performed before the control trial (CON). We measured circulating TG-rich lipoprotein concentrations and affinity of chylomicrons, VLDL1, and VLDL2 for LPL-mediated TG hydrolysis. Exercise significantly reduced fasting VLDL1-TG concentration (CON, 0.49 [0.33-0.72] mmol.L(-1); EX, 0.36 [0.22-0.59] mmol.L(-1); geometric means [95% confidence interval]; P = .04). Time-averaged postprandial chylomicron-TG (CON, 0.55 ± 0.10 mmol.L(-1); EX, 0.39 ± 0.08 mmol.L(-1); mean ± SEM; P = .03) and VLDL1-TG (CON, 0.85 ± 0.13 mmol.L(-1); EX, 0.66 ± 0.10 mmol.L(-1); P = .01) concentrations were both lower in EX than CON. Affinity of VLDL1 for LPL-mediated TG hydrolysis increased by 2.2 (1.3-3.7)-fold [geometric mean (95% confidence interval)] (P = .02) in the fasted state and 2.6 (1.8-2.6)-fold (P = .001) postprandially. Affinity of chylomicrons and VLDL2 was not significantly different between trials. Exercise increases affinity of VLDL1 for LPL-mediated TG hydrolysis both fasting and postprandially. This mechanism is likely to contribute to the TG-lowering effect of exercise.

  18. Nanotopography applications in drug delivery

    Science.gov (United States)

    Walsh, Laura A; Allen, Jessica L; Desai, Tejal A

    2016-01-01

    Refinement of micro- and nanofabrication in the semiconductor field has led to innovations in biomedical technologies. Nanotopography, in particular, shows great potential in facilitating drug delivery. The flexibility of fabrication techniques has created a diverse array of topographies that have been developed for drug delivery applications. Nanowires and nanostraws deliver drug cytosolically for in vitro and ex vivo applications. In vivo drug delivery is limited by the barrier function of the epithelium. Nanowires on microspheres increase adhesion and residence time for oral drug delivery, while also increasing permeability of the epithelium. Low aspect ratio nanocolumns increase paracellular permeability, and in conjunction with microneedles increase transdermal drug delivery of biologics in vivo. In summary, nanotopography is a versatile tool for drug delivery. It can deliver directly to cells or be used for in vivo delivery across epithelial barriers. This editorial highlights the application of nanotopography in the field of drug delivery. PMID:26512871

  19. Aldose-ketose transformation for separation and/or chemical conversion of C6 and C5 sugars from biomass materials

    Energy Technology Data Exchange (ETDEWEB)

    Varanasi, Sasidhar; Relue, Patricia; Li, Bin

    2016-01-26

    Systems for converting aldose sugars to ketose sugars and separating and/or concentrating these sugars using differences in the sugars' abilities to bind to specific affinity ligands are described.

  20. Density Functional Study of Structures and Electron Affinities of BrO4F/BrO4F-

    Directory of Open Access Journals (Sweden)

    Wei Li

    2009-07-01

    Full Text Available The structures, electron affinities and bond dissociation energies of BrO4F/BrO4F− species have been investigated with five density functional theory (DFT methods with DZP++ basis sets. The planar F-Br…O2…O2 complexes possess 3A' electronic state for neutral molecule and 4A' state for the corresponding anion. Three types of the neutral-anion energy separations are the adiabatic electron affinity (EAad, the vertical electron affinity (EAvert, and the vertical detachment energy (VDE. The EAad value predicted by B3LYP method is 4.52 eV. The bond dissociation energies De (BrO4F → BrO4-mF + Om (m = 1-4 and De- (BrO4F- → BrO4-mF- + Om and BrO4F- → BrO4-mF + Om- are predicted. The adiabatic electron affinities (EAad were predicted to be 4.52 eV for F-Br…O2…O2 (3A'← 4A' (B3LYP method.

  1. Molecular basis for the wide range of affinity found in Csr/Rsm protein-RNA recognition.

    Science.gov (United States)

    Duss, Olivier; Michel, Erich; Diarra dit Konté, Nana; Schubert, Mario; Allain, Frédéric H-T

    2014-04-01

    The carbon storage regulator/regulator of secondary metabolism (Csr/Rsm) type of small non-coding RNAs (sRNAs) is widespread throughout bacteria and acts by sequestering the global translation repressor protein CsrA/RsmE from the ribosome binding site of a subset of mRNAs. Although we have previously described the molecular basis of a high affinity RNA target bound to RsmE, it remains unknown how other lower affinity targets are recognized by the same protein. Here, we have determined the nuclear magnetic resonance solution structures of five separate GGA binding motifs of the sRNA RsmZ of Pseudomonas fluorescens in complex with RsmE. The structures explain how the variation of sequence and structural context of the GGA binding motifs modulate the binding affinity for RsmE by five orders of magnitude (∼10 nM to ∼3 mM, Kd). Furthermore, we see that conformational adaptation of protein side-chains and RNA enable recognition of different RNA sequences by the same protein contributing to binding affinity without conferring specificity. Overall, our findings illustrate how the variability in the Csr/Rsm protein-RNA recognition allows a fine-tuning of the competition between mRNAs and sRNAs for the CsrA/RsmE protein.

  2. Optimizing drugs for local delivery.

    Science.gov (United States)

    Collingwood, S; Lock, R; Searcey, M

    2009-12-01

    An international panel of speakers together with approximately 70 delegates were brought together by The Society for Medicines Research's symposium on Optimising Drugs for Local Delivery, held on June 11, 2009 at the Novartis Institutes for Biomedical Research, Horsham, UK. The focus of the conference was on the delivery of drugs direct to the site of action and the consequences of this delivery route on delivery technologies, formulation science and molecular design.

  3. Microprocessor controlled transdermal drug delivery.

    Science.gov (United States)

    Subramony, J Anand; Sharma, Ashutosh; Phipps, J B

    2006-07-06

    Transdermal drug delivery via iontophoresis is reviewed with special focus on the delivery of lidocaine for local anesthesia and fentanyl for patient controlled acute therapy such as postoperative pain. The role of the microprocessor controller in achieving dosimetry, alternating/reverse polarity, pre-programmed, and sensor-based delivery is highlighted. Unique features such as the use of tactile signaling, telemetry control, and pulsatile waveforms in iontophoretic drug delivery are described briefly.

  4. MEMS: Enabled Drug Delivery Systems.

    Science.gov (United States)

    Cobo, Angelica; Sheybani, Roya; Meng, Ellis

    2015-05-01

    Drug delivery systems play a crucial role in the treatment and management of medical conditions. Microelectromechanical systems (MEMS) technologies have allowed the development of advanced miniaturized devices for medical and biological applications. This Review presents the use of MEMS technologies to produce drug delivery devices detailing the delivery mechanisms, device formats employed, and various biomedical applications. The integration of dosing control systems, examples of commercially available microtechnology-enabled drug delivery devices, remaining challenges, and future outlook are also discussed.

  5. diffusive phase separation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kenmochi

    1996-01-01

    w is constrained to have double obstacles σ*≤w≤σ* (i.e., σ* and σ* are the threshold values of w. The objective of this paper is to discuss the semigroup {S(t} associated with the phase separation model, and construct its global attractor.

  6. Phase separation micro molding

    NARCIS (Netherlands)

    Vogelaar, Laura

    2005-01-01

    The research described in this thesis concerns the development of a new microfabrication method, Phase Separation Micro Molding (PSμM). While microfabrication is still best known from semiconductor industry, where it is used to integrate electrical components on a chip, the scope has immensely expan

  7. Fathering After Marital Separation

    Science.gov (United States)

    Keshet, Harry Finkelstein; Rosenthal, Kristine M.

    1978-01-01

    Deals with experiences of a group of separated or divorced fathers who chose to remain fully involved in the upbringing of their children. As they underwent transition from married parenthood to single fatherhood, these men learned that meeting demands of child care contributed to personal stability and growth. (Author)

  8. Isotope hydrograph separation

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, P. [UFZ-Umweltforschungszentrum, Centre of Environmental Research Leipzig-Halle, Leipzig (Germany)

    2000-07-01

    Storm-runoff thus reflects the complex hydraulic behaviour of drainage basins and water-links of such systems. Water of different origin may participate in the events and in this lecture, the application of isotope techniques to separate storm hydrographs into different components will be presented.

  9. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    This PhD thesis asks how we can conceptualize the current separation doctrine of religion and politics in a country like Denmark, where the structure of the established church and peoplehood overlap. In order to answer this question, Hans Bruun Dabelsteen maps the current discussion of secularism...

  10. Acromioclavicular Joint Separations

    Science.gov (United States)

    2013-01-01

    Published online: 16 December 2012 # Springer Science+Business Media New York 2012 Abstract Acromioclavicular (AC) joint separations are common...injuries. The sports most likely to cause AC joint dislocations are football, soccer , hockey, rugby, and skiing, among others [9, 28, 29]. The major cause

  11. Pre-Separation Guide

    Science.gov (United States)

    1992-03-04

    SEPARATEES Defense Outplacement Referral System (DORS) Since most of us are not independently wealthy, we will need a job after separation. DORS is...Job Assistance SPOUSES OF ALL SEPARATEES As a spouse you may take advantage of preparing Standard Form 17 1’s and resu- the outplacement services

  12. Separation of Powers.

    Science.gov (United States)

    Bill of Rights in Action, 1987

    1987-01-01

    The dimensions of the separation of powers principle are explored through three lessons in the subject areas of U.S. history, U.S. government, and world history. In 1748, a French nobleman, Baron de Montesquieu, wrote a book called "The Spirit of the Laws," in which he argued that there could be no liberty when all government power was…

  13. Affine kinematics in planar fibrous connective tissues: an experimental investigation.

    Science.gov (United States)

    Jayyosi, C; Affagard, J-S; Ducourthial, G; Bonod-Bidaud, C; Lynch, B; Bancelin, S; Ruggiero, F; Schanne-Klein, M-C; Allain, J-M; Bruyère-Garnier, K; Coret, M

    2017-03-29

    The affine transformation hypothesis is usually adopted in order to link the tissue scale with the fibers scale in structural constitutive models of fibrous tissues. Thanks to the recent advances in imaging techniques, such as multiphoton microscopy, the microstructural behavior and kinematics of fibrous tissues can now be monitored at different stretching within the same sample. Therefore, the validity of the affine hypothesis can be investigated. In this paper, the fiber reorientation predicted by the affine assumption is compared to experimental data obtained during mechanical tests on skin and liver capsule coupled with microstructural imaging using multiphoton microscopy. The values of local strains and the collagen fibers orientation measured at increasing loading levels are used to compute a theoretical estimation of the affine reorientation of collagen fibers. The experimentally measured reorientation of collagen fibers during loading could not be successfully reproduced with this simple affine model. It suggests that other phenomena occur in the stretching process of planar fibrous connective tissues, which should be included in structural constitutive modeling approaches.

  14. Selective affinity of pirenzepine analogues for subtypes of muscarinic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Stubbins, J.F.; Smith, J.D.; Liu, W.S.; Gulya, K.; Yamamura, H.I.

    1986-03-05

    Pirenzepine (PZ), telenzepine (TZ) and quinuclidinyl xanthene-9-carboxylate (QNX) are antimuscarinic agents containing a tricyclic ring system and a basic side chain that have been reported to have selective affinity for the M/sub 1/ subtype of receptor. They have prepared and examined seven new PZ analogues containing modifications in either the tricyclic ring system, the side-chain, or both. Affinity for M/sub 1/ type receptors was determined by displacement of specifically-bound (/sup 3/H)PZ from rat cerebral cortex homogenates. Affinity for M/sub 2/ type receptors was measured on rat heart homogenate using (/sup 3/H)(-)quinuclidinyl benzilate. The ratio of the K/sub i/'s for M/sub 1/ and M/sub 2/ receptors were calculated and compared to PZ. All of the compounds had a higher affinity for M/sub 1/ than M/sub 2/ receptors. Three of the compounds were comparable to PZ in selectivity, but the more selective compounds had a weaker affinity for M/sub 1/ receptors. TZ and QNX were less selective than PZ.

  15. The proton affinities of saturated and unsaturated heterocyclic molecules

    Science.gov (United States)

    Kabli, Samira; van Beelen, Eric S. E.; Ingemann, Steen; Henriksen, Lars; Hammerum, Steen

    2006-03-01

    The proton affinities derived from G3-calculations of 23 five-membered ring heteroaromatic molecules agree well with the experimentally determined values available in the literature. The calculated local proton affinities show that the principal site of protonation of the heteroaromatic compounds examined is an atom of the ring, carbon when there is only one heteroatom in the ring, and nitrogen where there are two or more heteroatoms. The experimental proton affinities of non-aromatic cyclic ethers, amines and thioethers are also in excellent agreement with the calculated values, with two exceptions (oxetane, N-methylazetidine). The literature proton affinities of the four simple cyclic ethers, oxetane, tetrahydrofuran, tetrahydropyran and oxepane were confirmed by Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, in order to examine the disagreement between the values predicted by extrapolation or additivity for tetrahydrofuran and tetrahydropyran and those determined by experiment and by calculation. The proton affinity differences between the pairs tetrahydropyran/1,4-dioxane, piperidine/morpholine and related compounds show that introduction of an additional oxygen atom in the ring considerably lowers the basicity.

  16. What Is a Cesarean Delivery?

    Science.gov (United States)

    ... are common complications? What is a high-risk pregnancy? What is labor? What is a cesarean delivery? Other FAQs NICHD Research Information Clinical Trials Resources and Publications What is a cesarean delivery? Skip sharing on social media links Share this: Page Content A cesarean delivery ...

  17. Craniodental affinities of Southeast Asia's "negritos" and the concordance with their genetic affinities.

    Science.gov (United States)

    Bulbeck, David

    2013-01-01

    Genetic research into Southeast Asia's "negritos" has revealed their deep-rooted ancestry, with time depth comparable to that of Southwest Pacific populations. This finding is often interpreted as evidence that negritos, in contrast to other Southeast Asians, can trace much of their ancestry directly back to the early dispersal of Homo sapiens in the order of 70 kya from Africa to Pleistocene New Guinea and Australia. One view on negritos is to lump them and Southwest Pacific peoples into an "Australoid" race whose geographic distribution had included Southeast Asia prior to the Neolithic incursion of "Mongoloid" farmers. Studies into Semang osteology have revealed some hints of Southwest Pacific affinities in cranial shape, dental morphology, and dental metrical "shape." On the other hand, the Andamanese have been shown to resemble Africans in their craniometrics and South Asians in their dental morphology, while Philippine negritos resemble Mongoloid Southeast Asians in these respects and also in their dental metrics. This study expands the scope of negrito cranial comparisons by including Melayu Malays and additional coverage of South Asians. It highlights the distinction between the Mongoloid-like Philippine negritos and the Andamanese and Semang (and Senoi of Malaya) with their non-Mongoloid associations. It proposes that the early/mid-Holocene dispersal of the B4a1a mitochondrial DNA clade across Borneo, the Philippines, and Taiwan may be important for understanding the distinction between Philippine and other negritos.

  18. How boundaries shape chemical delivery in microfluidics

    Science.gov (United States)

    Aminian, Manuchehr; Bernardi, Francesca; Camassa, Roberto; Harris, Daniel M.; McLaughlin, Richard M.

    2016-12-01

    Many microfluidic systems—including chemical reaction, sample analysis, separation, chemotaxis, and drug development and injection—require control and precision of solute transport. Although concentration levels are easily specified at injection, pressure-driven transport through channels is known to spread the initial distribution, resulting in reduced concentrations downstream. Here we document an unexpected phenomenon: The channel’s cross-sectional aspect ratio alone can control the shape of the concentration profile along the channel length. Thin channels (aspect ratio delivery, based only on the channel dimensions.

  19. Relative binding affinity of carboxylate-, phosphonate-, and bisphosphonate-functionalized gold nanoparticles targeted to damaged bone tissue

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Ryan D. [Rush University Medical Center, Department of Anatomy and Cell Biology (United States); Cole, Lisa E.; Roeder, Ryan K., E-mail: rroeder@nd.edu [University of Notre Dame, Department of Aerospace and Mechanical Engineering Bioengineering Graduate Program (United States)

    2012-10-15

    Functionalized Au NPs have received considerable recent interest for targeting and labeling cells and tissues. Damaged bone tissue can be targeted by functionalizing Au NPs with molecules exhibiting affinity for calcium. Therefore, the relative binding affinity of Au NPs surface functionalized with either carboxylate (l-glutamic acid), phosphonate (2-aminoethylphosphonic acid), or bisphosphonate (alendronate) was investigated for targeted labeling of damaged bone tissue in vitro. Targeted labeling of damaged bone tissue was qualitatively verified by visual observation and backscattered electron microscopy, and quantitatively measured by the surface density of Au NPs using field-emission scanning electron microscopy. The surface density of functionalized Au NPs was significantly greater within damaged tissue compared to undamaged tissue for each functional group. Bisphosphonate-functionalized Au NPs exhibited a greater surface density labeling damaged tissue compared to glutamic acid- and phosphonic acid-functionalized Au NPs, which was consistent with the results of previous work comparing the binding affinity of the same functionalized Au NPs to synthetic hydroxyapatite crystals. Targeted labeling was enabled not only by the functional groups but also by the colloidal stability in solution. Functionalized Au NPs were stabilized by the presence of the functional groups, and were shown to remain well dispersed in ionic (phosphate buffered saline) and serum (fetal bovine serum) solutions for up to 1 week. Therefore, the results of this study suggest that bisphosphonate-functionalized Au NPs have potential for targeted delivery to damaged bone tissue in vitro and provide motivation for in vivo investigation.

  20. High-affinity FRβ-specific CAR T cells eradicate AML and normal myeloid lineage without HSC toxicity.

    Science.gov (United States)

    Lynn, R C; Feng, Y; Schutsky, K; Poussin, M; Kalota, A; Dimitrov, D S; Powell, D J

    2016-06-01

    Acute myeloid leukemia (AML) is an aggressive malignancy, and development of new treatments to prolong remissions is warranted. Chimeric antigen receptor (CAR) T-cell therapies appear promising but on-target, off-tumor recognition of antigen in healthy tissues remains a concern. Here we isolated a high-affinity (HA) folate receptor beta (FRβ)-specific single-chain variable fragment (2.48 nm KD) for optimization of FRβ-redirected CAR T-cell therapy for AML. T cells stably expressing the HA-FRβ CAR exhibited greatly enhanced antitumor activity against FRβ(+) AML in vitro and in vivo compared with a low-affinity FRβ CAR (54.3 nm KD). Using the HA-FRβ immunoglobulin G, FRβ expression was detectable in myeloid-lineage hematopoietic cells; however, expression in CD34(+) hematopoietic stem cells (HSCs) was nearly undetectable. Accordingly, HA-FRβ CAR T cells lysed mature CD14(+) monocytes, while HSC colony formation was unaffected. Because of the potential for elimination of mature myeloid lineage, mRNA CAR electroporation for transient CAR expression was evaluated. mRNA-electroporated HA-FRβ CAR T cells retained effective antitumor activity in vitro and in vivo. Together, our results highlight the importance of antibody affinity in target protein detection and CAR development and suggest that transient delivery of potent HA-FRβ CAR T cells is highly effective against AML and reduces the risk for long-term myeloid toxicity.

  1. Using glycosaminoglycan/chemokine interactions for the long-term delivery of 5P12-RANTES in HIV prevention.

    Science.gov (United States)

    Wang, Nick X; Sieg, Scott F; Lederman, Michael M; Offord, Robin E; Hartley, Oliver; von Recum, Horst A

    2013-10-07

    5P12-RANTES is a recently developed chemokine analogue that has shown high level protection from SHIV infection in macaques. However, the feasibility of using 5P12-RANTES as a long-term HIV prevention agent has not been explored partially due to the lack of available delivery devices that can easily be modified for long-term release profiles. Glycosaminoglycans (GAGs) have been known for their affinity for various cytokines and chemokines, including native RANTES, or CCL5. In this work, we investigated used of GAGs in generating a chemokine drug delivery device. Initial studies used surface plasmon resonance analysis to characterize and compare the affinities of different GAGs to 5P12-RANTES. These different GAGs were then incorporated into drug delivery polymeric hydrogels to engineer sustained release of the chemokines. In vitro release studies of 5P12-RANTES from the resulting polymers were performed, and we found that 5P12-RANTES release from these polymers can be controlled by the amount and type of GAG incorporated. Polymer disks containing GAGs with stronger affinity to 5P12-RANTES resulted in more sustained and longer term release than did polymer disks containing GAGs with weaker 5P12-RANTES affinity. Similar trends were observed by varying the amount of GAGs incorporated into the delivery system. 5P12-RANTES released from these polymers demonstrated good levels of CCR5 blocking, retaining activity even after 30 days of incubation.

  2. Recovery and separation of rare Earth elements using salmon milt.

    Directory of Open Access Journals (Sweden)

    Yoshio Takahashi

    Full Text Available Recycling rare earth elements (REEs used in advanced materials such as Nd magnets is important for the efficient use of REE resources when the supply of several REEs is limited. In this work, the feasibility of using salmon milt for REE recovery and separation was examined, along with the identification of the binding site of REEs in salmon milt. Results showed that (i salmon milt has a sufficiently high affinity to adsorb REEs and (ii the adsorption capacity of the milt is 1.04 mEq/g, which is comparable with that of commercial cation exchange resin. Heavier REEs have higher affinity for milt. A comparison of stability constants and adsorption patterns of REEs discussed in the literature suggests that the phosphate is responsible for the adsorption of REE in milt. The results were supported by dysprosium (Dy and lutetium (Lu LIII-edge extended x-ray absorption fine structure (EXAFS spectroscopy. The REE-P shell was identified for the second neighboring atom, which shows the importance of the phosphate site as REE binding sites. The comparison of REE adsorption pattern and EXAFS results between the milt system and other adsorbent systems (cellulose phosphate, Ln-resin, bacteria, and DNA-filter hybrid revealed that the coordination number of phosphate is correlated with the slope of the REE pattern. The separation column loaded with milt was tested to separate REE for the practical use of salmon milt for the recovery and separation of REE. However, water did not flow through the column possibly because of the hydrophobicity of the milt. Thus, sequential adsorption-desorption approach using a batch-type method was applied for the separation of REE. As an example of the practical applications of REE separation, Nd and Fe(III were successfully separated from a synthetic solution of Nd magnet waste by a batch-type method using salmon milt.

  3. Taking advantage: high-affinity B cells in the germinal center have lower death rates, but similar rates of division, compared to low-affinity cells.

    Science.gov (United States)

    Anderson, Shannon M; Khalil, Ashraf; Uduman, Mohamed; Hershberg, Uri; Louzoun, Yoram; Haberman, Ann M; Kleinstein, Steven H; Shlomchik, Mark J

    2009-12-01

    B lymphocytes producing high-affinity Abs are critical for protection from extracellular pathogens, such as bacteria and parasites. The process by which high-affinity B cells are selected during the immune response has never been elucidated. Although it has been shown that high-affinity cells directly outcompete low-affinity cells in the germinal center (GC), whether there are also intrinsic differences between these cells has not been addressed. It could be that higher affinity cells proliferate more rapidly or are more likely to enter cell cycle, thereby outgrowing lower affinity cells. Alternatively, higher affinity cells could be relatively more resistant to cell death in the GC. By comparing high- and low-affinity B cells for the same Ag, we show here that low-affinity cells have an intrinsically higher death rate than do cells of higher affinity, even in the absence of competition. This suggests that selection in the GC reaction is due at least in part to the control of survival of higher affinity B cells and not by a proliferative advantage conferred upon these cells compared with lower affinity B cells. Control over survival rather than proliferation of low- and high-affinity B cells in the GC allows greater diversity not only in the primary response but also in the memory response.

  4. Mucoadhesive drug delivery systems

    Directory of Open Access Journals (Sweden)

    Rahamatullah Shaikh

    2011-01-01

    Full Text Available Mucoadhesion is commonly defined as the adhesion between two materials, at least one of which is a mucosal surface. Over the past few decades, mucosal drug delivery has received a great deal of attention. Mucoadhesive dosage forms may be designed to enable prolonged retention at the site of application, providing a controlled rate of drug release for improved therapeutic outcome. Application of dosage forms to mucosal surfaces may be of benefit to drug molecules not amenable to the oral route, such as those that undergo acid degradation or extensive first-pass metabolism. The mucoadhesive ability of a dosage form is dependent upon a variety of factors, including the nature of the mucosal tissue and the physicochemical properties of the polymeric formulation. This review article aims to provide an overview of the various aspects of mucoadhesion, mucoadhesive materials, factors affecting mucoadhesion, evaluating methods, and finally various mucoadhesive drug delivery systems (buccal, nasal, ocular, gastro, vaginal, and rectal.

  5. Social video content delivery

    CERN Document Server

    Wang, Zhi; Zhu, Wenwu

    2016-01-01

    This brief presents new architecture and strategies for distribution of social video content. A primary framework for socially-aware video delivery and a thorough overview of the possible approaches is provided. The book identifies the unique characteristics of socially-aware video access and social content propagation, revealing the design and integration of individual modules that are aimed at enhancing user experience in the social network context. The change in video content generation, propagation, and consumption for online social networks, has significantly challenged the traditional video delivery paradigm. Given the massive amount of user-generated content shared in online social networks, users are now engaged as active participants in the social ecosystem rather than as passive receivers of media content. This revolution is being driven further by the deep penetration of 3G/4G wireless networks and smart mobile devices that are seamlessly integrated with online social networking and media-sharing s...

  6. Pyomyositis after vaginal delivery.

    LENUS (Irish Health Repository)

    Gaughan, Eve

    2011-01-01

    Pyomyositis is a purulent infection of skeletal muscle that arises from haematogenous spread, usually with abscess formation. It can develop after a transient bacteraemia of any cause. This type of infection has never been reported before in the literature after vaginal delivery. A 34-year-old woman had progressive severe pain in the left buttock and thigh and weakness in the left lower limb day 1 post spontaneous vaginal delivery. MRI showed severe oedema of the left gluteus, iliacus, piriformis and adductor muscles of the left thigh and a small fluid collection at the left hip joint. She was diagnosed with pyomyositis. She had fever of 37.9°C immediately postpartum and her risk factors for bacteraemia were a mild IV cannula-associated cellulitis and labour itself. She required prolonged treatment with antibiotics before significant clinical improvement was noted.

  7. Delivery strategies for antiparasitics.

    Science.gov (United States)

    Kayser, Oliver; Kiderlen, Albrecht F

    2003-02-01

    Optimisation of drug carrier systems and drug delivery strategies that take into account the peculiarities of individual infectious agents and diseases are key elements of modern drug development. In the following, different aspects of a rational design for antiparasitic drug formulation will be reviewed, covering delivery systems such as nano- and microparticles, liposomes, emulsions and microemulsions, cochleates and bioadhesive macromolecules. Functional properties for each carrier system will be discussed as well as their therapeutic efficacy for parasitic diseases, including leishmaniasis, human African trypanosomiasis, human cryptosporidiosis, malaria and schistosomiasis. Critical issues for the application of drug carrier systems will be discussed, focusing on biopharmaceutical and pathophysiological parameters such as routes of application, improvement of body distribution and targeting intracellularly persisting pathogens.

  8. Transcutaneous antigen delivery system

    Directory of Open Access Journals (Sweden)

    Mi-Young Lee

    2013-01-01

    Full Text Available Transcutaneous immunization refers to the topical applicationof antigens onto the epidermis. Transcutaneous immunizationtargeting the Langerhans cells of the skin has received muchattention due to its safe, needle-free, and noninvasive antigendelivery. The skin has important immunological functions withunique roles for antigen-presenting cells such as epidermalLangerhans cells and dermal dendritic cells. In recent years,novel vaccine delivery strategies have continually beendeveloped; however, transcutaneous immunization has not yetbeen fully exploited due to the penetration barrier representedby the stratum corneum, which inhibits the transport ofantigens and adjuvants. Herein we review recent achievementsin transcutaneous immunization, focusing on the variousstrategies for the enhancement of antigen delivery andvaccination efficacy. [BMB Reports 2013; 46(1: 17-24

  9. Microneedle technologies for (trans)dermal drug and vaccine delivery.

    Science.gov (United States)

    van der Maaden, Koen; Jiskoot, Wim; Bouwstra, Joke

    2012-07-20

    Microneedles have been used for the dermal and transdermal delivery of a broad range of drugs, such as small molecular weight drugs, oligonucleotides, DNA, peptides, proteins and inactivated viruses. However, until now there are no microneedle-based (trans)dermal drug delivery systems on the market. In the past decade various types of microneedles have been developed by a number of production processes. Numerous geometries of microneedles have been designed from various materials. These microneedles have been used for different approaches of microneedle-based (trans)dermal drug delivery. Following a brief introduction about dermal and transdermal drug delivery, this review describes different production methods for solid and hollow microneedles as well as conditions that influence skin penetration. Besides, the four microneedle-based (trans)dermal drug delivery approaches are discussed: "poke and flow", "poke and patch", "poke and release", and "coat and poke". A separate section of this review is devoted to the use of microneedles for the delivery of therapeutic proteins and vaccines. Finally, we give our view on research and development that is needed to render microneedle-based (trans)dermal drug delivery technologies clinically useful in the near future.

  10. Transdermal Delivery of Proteins

    OpenAIRE

    Kalluri, Haripriya; Banga, Ajay K.

    2011-01-01

    Transdermal delivery of peptides and proteins avoids the disadvantages associated with the invasive parenteral route of administration and other alternative routes such as the pulmonary and nasal routes. Since proteins have a large size and are hydrophilic in nature, they cannot permeate passively across the skin due to the stratum corneum which allows the transport of only small lipophilic drug molecules. Enhancement techniques such as chemical enhancers, iontophoresis, microneedles, electro...

  11. Microgravity Passive Phase Separator

    Science.gov (United States)

    Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

    2012-01-01

    A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface

  12. A fast quantum algorithm for the affine Boolean function identification

    Science.gov (United States)

    Younes, Ahmed

    2015-02-01

    Bernstein-Vazirani algorithm (the one-query algorithm) can identify a completely specified linear Boolean function using a single query to the oracle with certainty. The first aim of the paper is to show that if the provided Boolean function is affine, then one more query to the oracle (the two-query algorithm) is required to identify the affinity of the function with certainty. The second aim of the paper is to show that if the provided Boolean function is incompletely defined, then the one-query and the two-query algorithms can be used as bounded-error quantum polynomial algorithms to identify certain classes of incompletely defined linear and affine Boolean functions respectively with probability of success at least 2/3.

  13. Single-cell measurement of red blood cell oxygen affinity

    CERN Document Server

    Caprio, Di; Higgins, John M; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume and hemoglobin concentration for individual red blood cells in high-throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.5%, which corresponds to the maximum slope of the oxygen-hemoglobin dissociation curve. In addition, single-cell oxygen affinity is positively correlated with hemoglobin concentr...

  14. Enhancing Community Detection By Affinity-based Edge Weighting Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Andy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sanders, Geoffrey [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Henson, Van [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, Panayot [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-05

    Community detection refers to an important graph analytics problem of finding a set of densely-connected subgraphs in a graph and has gained a great deal of interest recently. The performance of current community detection algorithms is limited by an inherent constraint of unweighted graphs that offer very little information on their internal community structures. In this paper, we propose a new scheme to address this issue that weights the edges in a given graph based on recently proposed vertex affinity. The vertex affinity quantifies the proximity between two vertices in terms of their clustering strength, and therefore, it is ideal for graph analytics applications such as community detection. We also demonstrate that the affinity-based edge weighting scheme can improve the performance of community detection algorithms significantly.

  15. Affinity chromatography of acetylcholinesterase. The importance of hydrophobic interactions.

    Science.gov (United States)

    Massoulié, J; Bon, S

    1976-09-15

    An easily prepared affinity column for acetylcholinesterase is described, which may be operated at ionic strength high enough to prevent aggregation of the asymmetric forms of the enzyme. Specific elution by tetraethylammonium or decamethonium was quantitative. The performance of this column is comparable to that of the column described by Dudai and Silman. It is shown that the hexyl 'spacer arm' strongly participates in the enzyme binding and that its replacement with the more hydrophilic spermine chain lowers the affinity. The hexyl chain itself is shown to bind acetylcholinesterase, although with lower affinity and capacity than the complete column. This binding is also partly reversed by inhibitors. Such hydrophobic columns bind the native asymmetric forms of the enzyme more strongly than the lytic globular ones. The aromatic quaternary ligang inhibits Electrophorus but not Torpedo acetylcholinesterase; therefore the column does not retain the Torpedo enzyme. Differences in Km between acetylcholinesterases of the two species also point to differences in their active sites.

  16. Fast Affinity Propagation Clustering based on Machine Learning

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar Shrivastava

    2013-01-01

    Full Text Available Affinity propagation (AP was recently introduced as an un-supervised learning algorithm for exemplar based clustering. In this paper a novel Fast Affinity Propagation clustering Approach based on Machine Learning (FAPML has been proposed. FAPML tries to put data points into clusters based on the history of the data points belonging to clusters in early stages. In FAPML we introduce affinity learning constant and dispersion constant which supervise the clustering process. FAPML also enforces the exemplar consistency and one of 'N constraints. Experiments conducted on many data sets such as Olivetti faces, Mushroom, Documents summarization, Thyroid, Yeast, Wine quality Red, Balance etc. show that FAPML is up to 54 % faster than the original AP with better Net Similarity.

  17. The Affine Structure of Gravitational Theories: Symplectic Groups and Geometry

    CERN Document Server

    Capozziello, Salvatore; De Laurentis, Mariafelicia

    2014-01-01

    We give a geometrical description of gravitational theories from the viewpoint of symmetries and affine structure. We show how gravity, considered as a gauge theory, can be consistently achieved by the nonlinear realization of the conformal-affine group in an indirect manner: due the partial isomorphism between $CA\\left( 3,1\\right) $ and the centrally extended $Sp\\left( 8\\right) $, we perform a nonlinear realization of the centrally extended (CE)$Sp\\left( 8\\right) $ in its semi-simple version. In particular, starting from the bundle structure of gravity, we derive the conformal-affine Lie algebra and then, by the non-linear realization, we define the coset field transformations, the Cartan forms and the inverse Higgs constraints. Finally we discuss the geometrical Lagrangians where all the information on matter fields and their interactions can be contained.

  18. k-Schur functions and affine Schubert calculus

    CERN Document Server

    Lam, Thomas; Morse, Jennifer; Schilling, Anne; Shimozono, Mark; Zabrocki, Mike

    2014-01-01

    This book gives an introduction to the very active field of combinatorics of affine Schubert calculus, explains the current state of the art, and states the current open problems. Affine Schubert calculus lies at the crossroads of combinatorics, geometry, and representation theory. Its modern development is motivated by two seemingly unrelated directions. One is the introduction of k-Schur functions in the study of Macdonald polynomial positivity, a mostly combinatorial branch of symmetric function theory. The other direction is the study of the Schubert bases of the (co)homology of the affine Grassmannian, an algebro-topological formulation of a problem in enumerative geometry. This is the first introductory text on this subject. It contains many examples in Sage, a free open source general purpose mathematical software system, to entice the reader to investigate the open problems. This book is written for advanced undergraduate and graduate students, as well as researchers, who want to become familiar with ...

  19. Generalized Rogers-Ramanujan identities for twisted affine algebras

    Science.gov (United States)

    Genish, Arel; Gepner, Doron

    2017-07-01

    The characters of parafermionic conformal field theories are given by the string functions of affine algebras, which are either twisted or untwisted algebras. Expressions for these characters as generalized Rogers-Ramanujan algebras have been established for the untwisted affine algebras. However, we study the identities for the string functions of the twisted affine Lie algebras. A conjecture for the string functions was proposed by Hatayama et al., for the unit fields, which expresses the string functions as Rogers-Ramanujan type sums. Here we propose to check the Hatayama et al. conjecture, using Lie algebraic theoretic methods. We use Freudenthal’s formula, which we computerized, to verify the identities for all the algebras at low rank and low level. We find complete agreement with the conjecture.

  20. Super-Affine Hierarchies and their Poisson Embeddings

    CERN Document Server

    Toppan, F

    1998-01-01

    The link between (super)-affine Lie algebras as Poisson brackets structures and integrable hierarchies provides both a classification and a tool for obtaining superintegrable hierarchies. The lack of a fully systematic procedure for constructing matrix-type Lax operators, which makes the supersymmetric case essentially different from the bosonic counterpart, is overcome via the notion of Poisson embeddings (P.E.), i.e. Poisson mappings relating affine structures to conformal structures (in their simplest version P.E. coincide with the Sugawara construction). A full class of hierarchies can be recovered by using uniquely Lie-algebraic notions. The group-algebraic properties implicit in the super-affine picture allow a systematic derivation of reduced hierarchies by imposing either coset conditions or hamiltonian constraints (or possibly both).

  1. Properties of the Affine Invariant Ensemble Sampler in high dimensions

    CERN Document Server

    Huijser, David; Brewer, Brendon J

    2015-01-01

    We present theoretical and practical properties of the affine-invariant ensemble sampler Markov chain Monte Carlo method. In high dimensions the affine-invariant ensemble sampler shows unusual and undesirable properties. We demonstrate this with an $n$-dimensional correlated Gaussian toy problem with a known mean and covariance structure, and analyse the burn-in period. The burn-in period seems to be short, however upon closer inspection we discover the mean and the variance of the target distribution do not match the expected, known values. This problem becomes greater as $n$ increases. We therefore conclude that the affine-invariant ensemble sampler should be used with caution in high dimensional problems. We also present some theoretical results explaining this behaviour.

  2. REPRESENTATIONS OF AFFINE HECKE ALGEBRAS OF TYPE G2

    Institute of Scientific and Technical Information of China (English)

    Xi Nanhua

    2009-01-01

    Let k be a field and q a nonzero element in k such that the square roots of q are in k.We use Hq to denote an affine Hecke algebra over k of type G2 with parameter q.The purpose of this paper is to study representations of Hq by using based rings of two-sided cells of an affine Weyl group W of type G2.We shall give the classification of irreducible representations of Hq.We also remark that a calculation in [11] actually shows that Theorem 2 in [1] needs a modification, a fact is known to Grojnowski and Tanisaki long time ago.In this paper we also show an interesting relation between Hq and an Hecke algebra corresponding to a certain Coxeter group.Apparently the idea in this paper works for all affine Weyl groups, but that is the theme of another paper.

  3. Local release from affinity-based polymers increases urethral concentration of the stem cell chemokine CCL7 in rats.

    Science.gov (United States)

    Rivera-Delgado, Edgardo; Sadeghi, Zhina; Wang, Nick X; Kenyon, Jonathan; Satyanarayan, Sapna; Kavran, Michael; Flask, Chris; Hijaz, Adonis Z; von Recum, Horst A

    2016-04-21

    The protein chemokine (C-C motif) ligand 7 (CCL7) is significantly over-expressed in urethral and vaginal tissues immediately following vaginal distention in a rat model of stress urinary incontinence. Further evidence, in this scenario and other clinical scenarios, indicates CCL7 stimulates stem cell homing for regenerative repair. This CCL7 gradient is likely absent or compromised in the natural repair process of women who continue to suffer from SUI into advanced age. We evaluated the feasibility of locally providing this missing CCL7 gradient by means of an affinity-based implantable polymer. To engineer these polymers we screened the affinity of different proteoglycans, to use them as CCL7-binding hosts. We found heparin to be the strongest binding host for CCL7 with a 0.323 nM dissociation constant. Our experimental approach indicates conjugation of heparin to a polymer backbone (using either bovine serum albumin or poly (ethylene glycol) as the base polymer) can be used as a delivery system capable of providing sustained concentrations of CCL7 in a therapeutically useful range up to a month in vitro. With this approach we are able to detect, after polymer implantation, significant increase in CCL7 in the urethral tissue directly surrounding the polymer implants with only trace amounts of human CCL7 present in the blood of the animals. Whole animal serial sectioning shows evidence of retention of locally injected human mesenchymal stem cells (hMSCs) only in animals with sustained CCL7 delivery, 2 weeks after affinity-polymers were implanted.

  4. Neuroprotective effects of high affinity Σ1 receptor selective compounds.

    Science.gov (United States)

    Luedtke, Robert R; Perez, Evelyn; Yang, Shao-Hua; Liu, Ran; Vangveravong, Suwanna; Tu, Zhude; Mach, Robert H; Simpkins, James W

    2012-03-02

    We previously reported that the antipsychotic drug haloperidol, a multifunctional D2-like dopamine and sigma receptor subtype antagonist, has neuroprotective properties. In this study we further examined the association between neuroprotection and receptor antagonism by evaluating a panel of novel compounds with varying affinity at sigma and D2-like dopamine receptors. These compounds were evaluated using an in vitro cytotoxicity assay that utilizes a hippocampal-derived cell line, HT-22, in the presence or absence of varying concentrations (5 to 20 mM) of glutamate. While haloperidol was found to be a potent neuroprotective agent in this in vitro cell assay, the prototypic sigma 1 receptor agonist (+)-pentazocine was found not to be neuroprotective. Subsequently, the potency for the neuroprotection of HT-22 cells was evaluated for a) three SV series indoles which have nMolar affinity at D2-like receptors but varying affinity at sigma 1 receptor and b) two benzyl phenylacetamides sigma 1 receptor selective compounds which bind with low affinity at D2-like receptors but have nMolar affinity for the sigma 1 receptor. We observed that cytoprotection correlated with the affinity of the compounds for sigma 1 receptors. Based upon results from the HT-22 cell-based in vitro assay, two phenylacetamides, LS-127 and LS-137, were further evaluated in vivo using a transient middle cerebral artery occlusion (t-MCAO) model of stroke. At a dose of 100 μg/kg, both LS-127 and LS-137 attenuated infarct volume by approximately 50%. These studies provide further evidence that sigma 1 receptor selective compounds can provide neuroprotection in cytotoxic situations. These results also demonstrate that sigma 1 receptor selective benzyl phenylacetamides are candidate pharmacotherapeutic agents that could be used to minimize neuronal death after a stroke or head trauma.

  5. Separation of xylenes on Y zeolites in the vapor phase. 3. Choice of the suitable desorbent

    Energy Technology Data Exchange (ETDEWEB)

    Storti,; Carra, S.; Morbidelli, M.; Santacesaria, E.

    1985-01-01

    The choice of the most efficient desorbent is a key factor in the optimum design of an adsorption separation process through displacement chromatography. In this work different compounds are tested about their application as desorbent in the vapor phase adsorption separation of xylenes on Y zeolites. Among these, isopropylbenzene has been selected as the most appropriate for the process under examination. One of the fundamenta properties of a suitable desorbent for a separation process appears to be its affinity to the adsorbent, whic must be intermediate between those of the compounds to be separated.

  6. GPS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  7. HRS Separator HD

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  8. Nylon separators. [thermal degradation

    Science.gov (United States)

    Lim, H. S.

    1977-01-01

    A nylon separator was placed in a flooded condition in K0H solution and heated at various high temperatures ranging from 60 C to 110 C. The weight decrease was measured and the molecular weight and decomposition product were analyzed to determine: (1) the effect of K0H concentration on the hydrolysis rate; (2) the effect of K0H concentration on nylon degradation; (3) the activation energy at different K0H concentrations; and (4) the effect of oxygen on nylon degradation. The nylon hydrolysis rate is shown to increase as K0H concentration is decreased 34%, giving a maximum rate at about 16%. Separator hydrolysis is confirmed by molecular weight decrease in age of the batteries, and the reaction of nylon with molecular oxygen is probably negligible, compared to hydrolysis. The extrapolated rate value from the high temperature experiment correlates well with experimental values at 35 degrees.

  9. Battery separator manufacturing process

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, N.I.; Sugarman, N.

    1974-12-27

    A battery with a positive plate, a negative plate, and a separator of polymeric resin having a degree of undesirable hydrophobia, solid below 180/sup 0/F, extrudable as a hot melt, and resistant to degradation by at least either acids or alkalies positioned between the plates is described. The separator comprises a nonwoven mat of fibers, the fibers being comprised of the polymeric resin and a wetting agent in an amount of 0.5 to 20 percent by weight based on the weight of the resin with the amount being incompatible with the resin below the melting point of the resin such that the wetting agent will bloom over a period of time at ambient temperatures in a battery, yet being compatible with the resin at the extrusion temperature and bringing about blooming to the surface of the fibers when the fibers are subjected to heat and pressure.

  10. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    analysis, Dabelsteen study Danish secularism as an ideological concept. He finds that the conceptual structure of Danish secularism holds separation-as-principled distance at its core. Institutionally this particularly pertains to the establishment arrangement, and in practice it translates...... and proposes two conceptual expansions. The first is to include modest establishment in a framework of secularism defensible by political liberalism, and the second is to consider secularism in close connection to a theory of peoplehood. Methodologically positioned between interpretive realism and policy...... into the principle of treating everybody equally (with religious freedom, equality and Danish peoplehood as the most important principles adjacent to secularism). In a study of the historical roots of the separation doctrine and two current policy cases (same-sex marriage and reforms of church governance...

  11. Acoustophoresis separation method

    Science.gov (United States)

    Heyman, Joseph S. (Inventor)

    1993-01-01

    A method and apparatus are provided for acoustophoresis, i.e., the separation of species via acoustic waves. An ultrasonic transducer applies an acoustic wave to one end of a sample container containing at least two species having different acoustic absorptions. The wave has a frequency tuned to or harmonized with the point of resonance of the species to be separated. This wave causes the species to be driven to an opposite end of the sample container for removal. A second ultrasonic transducer may be provided to apply a second, oppositely directed acoustic wave to prevent undesired streaming. In addition, a radio frequency tuned to the mechanical resonance and coupled with a magnetic field can serve to identify a species in a medium comprising species with similar absorption coefficients, whereby an acoustic wave having a frequency corresponding to this gyrational rate can then be applied to sweep the identified species to one end of the container for removal.

  12. The growth rate of symplectic homology and affine varieties

    CERN Document Server

    McLean, Mark

    2010-01-01

    We will show that the cotangent bundle of an integrally hyperbolic manifold is not symplectomorphic to any smooth affine variety. We will also show that the unit cotangent bundle of such a manifold is not Stein fillable by a Stein domain whose completion is symplectomorphic to a smooth affine variety. For instance, these results hold when our manifolds are simply connected with at least one Betti number greater than the corresponding Betti number of the n torus. We use an invariant called the growth rate of symplectic homology to prove this result.

  13. Affine group representation formalism for four dimensional, Lorentzian, quantum gravity

    CERN Document Server

    Ching-Yi, Chou; Soo, Chopin

    2012-01-01

    The Hamiltonian constraint of 4-dimensional General Relativity is recast explicitly in terms of the Chern--Simons functional and the local volume operator. In conjunction with the algebraic quantization program, application of the affine quantization concept due to Klauder facilitates the construction of solutions to all of the the quantum constraints in the Ashtekar variables and their associated Hilbert space. A physical Hilbert space is constructed for Lorentzian signature gravity with nonzero cosmological constant in the form of unitary, irreducible representations of the affine group.

  14. Affine transformation crossed product like algebras and noncommutative surfaces

    CERN Document Server

    Arnlind, Joakim

    2009-01-01

    Several classes of *-algebras associated to the action of an affine transformation are considered, and an investigation of the interplay between the different classes of algebras is initiated. Connections are established that relate representations of *-algebras, geometry of algebraic surfaces, dynamics of affine transformations, graphs and algebras coming from a quantization procedure of Poisson structures. In particular, algebras related to surfaces being inverse images of fourth order polynomials (in R^3) are studied in detail, and a close link between representation theory and geometric properties is established for compact as well as non-compact surfaces.

  15. Solid support resins and affinity purification mass spectrometry.

    Science.gov (United States)

    Havis, Spencer; Moree, Wilna J; Mali, Sujina; Bark, Steven J

    2017-02-28

    Co-affinity purification-mass spectrometry (CoAP-MS) is a primary technology for elucidating the protein-protein interactions that form the basis of all biological processes. A critical component of CoAP-MS is the affinity purification (AP) of the bait protein, usually by immobilization of an antibody to a solid-phase resin. This Minireview discusses common resins, reagents, tagging methods, and their consideration for successful AP of tagged proteins. We discuss our experiences with different solid supports, their impact in AP experiments, and propose areas where chemistry can advance this important technology.

  16. Affinity Labeling of Membrane Receptors Using Tissue-Penetrating Radiations

    Science.gov (United States)

    Wong, Franklin C.; Boja, John; Ho, Beng; Kuhar, Michael J.; Wong, Dean F.

    2013-01-01

    Photoaffinity labeling, a useful in vivo biochemical tool, is limited when applied in vivo because of the poor tissue penetration by ultraviolet (UV) photons. This study investigates affinity labeling using tissue-penetrating radiation to overcome the tissue attenuation and irreversibly label membrane receptor proteins. Using X-ray (115 kVp) at low doses (affinity labeling of membrane receptors in a manner similar to UV with photoreactive ligands of the dopamine transporter, D2 dopamine receptor (D2R), and peripheral benzodiazepine receptor (PBDZR). It may provide specific noninvasive irreversible block or stimulation of a receptor using tissue-penetrating radiation targeting selected anatomic sites. PMID:23936811

  17. Affine diffusions and related processes simulation, theory and applications

    CERN Document Server

    Alfonsi, Aurélien

    2015-01-01

    This book gives an overview of affine diffusions, from Ornstein-Uhlenbeck processes to Wishart processes and it considers some related diffusions such as Wright-Fisher processes. It focuses on different simulation schemes for these processes, especially second-order schemes for the weak error. It also presents some models, mostly in the field of finance, where these methods are relevant and provides some numerical experiments. The book explains the mathematical background to understand affine diffusions and analyze the accuracy of the schemes.  

  18. Ferromagnetic Levan Composite: An Affinity Matrix to Purify Lectin

    Directory of Open Access Journals (Sweden)

    Renata Angeli

    2009-01-01

    Full Text Available A simple and inexpensive procedure used magnetite and levan to synthesize a composite recovered by a magnetic field. Lectins from Canavalia ensiformis (Con A and Cratylia mollis (Cramoll 1 and Cramoll 1,4 did bind specifically to composite. The magnetic property of derivative favored washing out contaminating proteins and recovery of pure lectins with glucose elution. Cramoll 1 was purified by this affinity binding procedure in two steps instead of a previous three-step protocol with ammonium sulfate fractionation, affinity chromatography on Sephadex G-75, and ion exchange chromatography through a CM-cellulose column.

  19. Separation of enantiomers

    CERN Document Server

    Todd , Matthew H

    2014-01-01

    In one handy volume this handbook summarizes the most common synthetic methods for the separation of racemic mixtures, allowing an easy comparison of the different strategies described in the literature.Alongside classical methods, the authors also consider kinetic resolutions, dynamic kinetic resolutions, divergent reactions of a racemic mixture, and a number of ""neglected"" cases not covered elsewhere, such as the use of circularly polarized light, polymerizations, ""ripening"" processes, dynamic combinatorial chemistry, and several thermodynamic processes. The result is a thorough introdu

  20. Separation Logic and Concurrency

    Science.gov (United States)

    Bornat, Richard

    Concurrent separation logic is a development of Hoare logic adapted to deal with pointers and concurrency. Since its inception, it has been enhanced with a treatment of permissions to enable sharing of data between threads, and a treatment of variables as resource alongside heap cells as resource. An introduction to the logic is given with several examples of proofs, culminating in a treatment of Simpson's 4-slot algorithm, an instance of racy non-blocking concurrency.