Sample records for native polyacrylamide gel

  1. Species identification of smoked and gravad fish products by sodium dodecylsulphate polyacrylamide gel electrophoresis, urea isoelectric focusing and native isoelectric focusing: a collaborative study

    Microsoft Academic Search

    I. Mackie; A. Craig; M. Etienne; M. Jerome; J. Fleurence; F. Jessen; A. Smelt; A. Kruijt; I Malmheden Yman; M Ferm; I Martinez; R Pérez-Mart??n; C Piñeiro; H Rehbein; R Kündiger

    2000-01-01

    A collaborative study on the use of sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), urea-isoelectric focusing (urea-IEF) and native isoelectric focusing for the identification of species of smoked salmonids, gravad salmonids and smoked eels was carried out by eight laboratories. With SDS-PAGE, minor changes took place in the profiles of the processed salmonid species making it impossible or very difficult to

  2. Separation of Native Allophycocyanin and R-Phycocyanin from Marine Red Macroalga Polysiphonia urceolata by the Polyacrylamide Gel Electrophoresis Performed in Novel Buffer Systems

    PubMed Central

    Wang, Yu; Gong, Xueqin; Wang, Shumei; Chen, Lixue; Sun, Li

    2014-01-01

    Three buffer systems of Imidazole?Acetic acid, HEPES?Imidazole/Bis-tris and Bis-tris?HEPES?MES were designed based on the principle of discontinuous polyacrylamide gel electrophoresis (PAGE) for the native PAGE which could be performed in pH 7.0 and 6.5 in order to analyze and prepare the minor components of allophycocyanin (AP) and R-phycocyanin (R-PC) from marine red macroalga Polysiphonia urceolata. These AP and R-PC phycobiliproteins are easily denatured in alkaline environments. The obtained results demonstrated that the PAGE modes performed in the buffer systems of HEPES?Imidazole/Bis-tris and Bis-tris?HEPES?MES gave the satisfactory resolution and separation of AP and R-PC proteins. The absorption and fluorescence spectra of the AP and R-PC proteins which were prepared by the established PAGE modes proved that they maintained natural spectroscopic characteristics. The established PAGE modes may also provide useful references and selections for some other proteins that are sensitive to alkaline environments or are not effectively separated by the classical PAGE modes performed normally in alkaline buffer systems. PMID:25166028

  3. A blue native polyacrylamide gel electrophoretic technology to probe the functional proteomics mediating nitrogen homeostasis in Pseudomonas fluorescens

    E-print Network

    Appanna, Vasu

    Keywords: Functional proteomics Nitrogen homeostasis Glutamate dehydrogenase Gel electrophoresis, glutamate and ammonia, with glutamate dehydrogenase (GDH, EC: 1.4.1.2) in the presence of either phena- zine. The enzyme glutamate dehydrogenase (GDH) is the key in the homeostasis of glutamate and consequently nitrogen

  4. Denaturing Urea Polyacrylamide Gel Electrophoresis (Urea PAGE)

    PubMed Central

    Summer, Heike; Grämer, René; Dröge, Peter

    2009-01-01

    Urea PAGE or denaturing urea polyacrylamide gel electrophoresis employs 6-8 M urea, which denatures secondary DNA or RNA structures and is used for their separation in a polyacrylamide gel matrix based on the molecular weight. Fragments between 2 to 500 bases, with length differences as small as a single nucleotide, can be separated using this method1. The migration of the sample is dependent on the chosen acrylamide concentration. A higher percentage of polyacrylamide resolves lower molecular weight fragments. The combination of urea and temperatures of 45-55 °C during the gel run allows for the separation of unstructured DNA or RNA molecules. In general this method is required to analyze or purify single stranded DNA or RNA fragments, such as synthesized or labeled oligonucleotides or products from enzymatic cleavage reactions. In this video article we show how to prepare and run the denaturing urea polyacrylamide gels. Technical tips are included, in addition to the original protocol 1,2. PMID:19865070

  5. Wide frequency rheological modeling of crosslinked polyacrylamide gels

    E-print Network

    to investigate the high frequency regime. Polyacrylamide gels were prepared using acrylamide at four different volume concentra- tions (5-7.5-10-15%), and bis­acrylamide (fixed concentration 0.03%) in deionized water

  6. Direct detection of beta-1,3-glucanase in plant extracts by polyacrylamide gel electrophoresis.

    PubMed

    Kalix, S; Buchenauer, H

    1995-06-01

    By using carboxymethyl (CM)-curdlan, a polysaccharide linked with the dye Remazol Brilliant Blue (RBB) as a substrate in polyacrylamide gels, the beta-1,3-glucanase in plant extracts can be detected directly by native polyacrylamide gel electrophoresis. In contrast to the usually used procedures for the detection of glucanases, e.g., colorimetric assay, overlay technique, enzyme activity staining using laminarin as a substrate, this method is rapid and allows both the determination of the activity and the location of the relative position of the multiple forms of beta-1,3-glucanases. PMID:7498122

  7. Dna electrophoresis in photopolymerized polyacrylamide gels on a microfluidic device 

    E-print Network

    Lo, Chih-Cheng

    2009-05-15

    and encourage- ment, and my wife and daughter for their patience and love. vii NOMENCLATURE %T Monomer concentration %C Crosslinker concentration bp base pairs BRM Biased reptation model BRF Biased reptation with fluctuations DNA..., such as DNA sequencing, detection of restriction fragment length polymorphisms (RFLP), and Southern blotting. Crosslinked polyacrylamide and agarose gels are generaly used as the sieving matrices in these sys- tems [47]. A slab gel is cast by loading liquid...

  8. odium dodecyl sulfate polyacry-lamide gel electrophoresis (SDS-

    E-print Network

    Lebendiker, Mario

    been attributed to three innovations that permit- ted the correlation of electrophoretic mobil- ity) and reducing agents to denature pro- teins (7). SDS binds strongly to proteins at an approximate ratio of 1-Cl 10 inNovations 13 Preparation of protein samples for SDS-polyacrylamide gel electrophoresis

  9. Renaturation of enzymes after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate

    SciTech Connect

    Lacks, S.A.; Springhorn, S.S.

    1980-08-10

    A number of enzymes, including amylases, dehydrogenases, and proteases, were shown to be renaturable after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Enzyme activity was detected in situ by action on substrates introduced into the gel and subsequent staining of either the product or unreacted substrate. Enzymes appeared to recover activity as soon as the detergent diffused out of the gel. Renatured enzymes were retained in gels after electrophoresis longer than native enzymes which had been subjected to electrophoresis in the absence of detergent. Re-electrophoresis of the renatured enzymes showed that part of the retained activity was physically anchored to the gel, possibly by the folding of polypeptides around the gel matrix as the enzymes were renatured.

  10. Phosphate-affinity polyacrylamide gel electrophoresis for SNP genotyping.

    PubMed

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

    2009-01-01

    We introduce a genotyping method which relies on the use of a 1:1 mixture of 5'-phosphate-labeled and nonlabeled allele-specific primers for polymerase chain reaction (PCR). The method is based on the difference in mobility of the phosphorylated and nonphosphorylated PCR products (possessing the same number of base pairs) during phosphate-affinity polyacrylamide gel electrophoresis (PAGE). The phosphate-affinity site in the gel is represented by an immobilized phosphate-binding tag molecule [i.e., a polyacrylamide-bound dizinc(II) complex], which selectively captures the 5'-phosphate-labeled allele-specific product compared with the corresponding nonlabeled one. The DNA migration bands obtained can be visualized by ethidium bromide staining. We demonstrate the genotyping of a single-nucleotide polymorphism reported in a human cardiac sodium channel gene, SCN5A, using the phosphate-affinity PAGE. PMID:19768594

  11. Western Blot of Stained Proteins from Dried Polyacrylamide Gels

    NASA Technical Reports Server (NTRS)

    Gruber, Claudia; Stan-Lotter, Helga

    1996-01-01

    Western blotting of proteins is customarily performed following their separation on polyacrylamide gels, either prior to staining (1) or, as recently reported, following staining (2). We describe here Western blotting with stained gels, which had been dried and some of which had been stored for years. This procedure permits immunological analysis of proteins, to which antisera may have become available only later, or where the application of newly developed sensitive detection methods is desired. Once rehydration of the gels is achieved, proteins can be-transferred to blotting membranes by any appropriate protocol. Proteins stained with Coomassie Blue have to be detected with a non-chromogenic method, such as the film-based enhanced chemiluminescence (ECL)2) procedure (3). Silver stained proteins, which transfer in the colorless form, may be visualized by any detection method, although, because of the usually very low amounts of proteins, detection by ECL is preferable. Blotting of stained proteins from rehydrated gels is as rapid and as quantitative as from freshly prepared gels, in contrast to blotting from wet stained gels, which requires extensive washing and results in low transfer efficiency (2). Together with a photographic record of the gel pattern, unambiguous identification of immunoreactive proteins from complex mixtures is possible. Some further applications of this work are discussed.

  12. IDENTIFICATION OF FISH SPECIES BY THIN-LAYER POLYACRYLAMIDE GEL ISOELECTRIC FOCUSING

    E-print Network

    -layer polyacrylamide gel isoelectric focusing (IEFl, as a new means of identifying fish species. Sarcoplasmic protein resolution and reproducibility of the protein patterns, starch gel zone electro- phoresis was applied resolution protein separation technique, thin- layer polyacrylamide gel isoelectric focusing (IEF), as a new

  13. Activity staining method of chitinase on chitin agar plate through polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Vipul Gohel; Pranav Vyas; H. S. Chhatpar

    2005-01-01

    A method for detection of chitinase activity on chitin agar plate after polyacrylamide gel electrophoresis is described. Different staining dyes such as calcofluor white M2R, fluorescein isothiocyanate, rhodamine B, ruthenium red and congo red were separately incorporated in chitin agar plates. After running polyacrylamide gel electrophoresis, the gel was transferred onto chitin agar plate containing different dyes for the activity

  14. Internal sequences from proteins digested in polyacrylamide gels.

    PubMed

    Jenö, P; Mini, T; Moes, S; Hintermann, E; Horst, M

    1995-01-01

    A simple method for proteolytic digestion of Coomassie blue-stained proteins in a polyacrylamide matrix is presented. It consists of first reducing and alkylating the stained proteins with dithiothreitol and iodoacetamide in the presence of 0.1% sodium dodecyl sulfate and subsequent digestion with the endoproteinase LysC. The reduction and alkylation step was introduced since experiments with lysozyme and ribonuclease A showed that extremely complex peptide patterns were obtained if no precautions were taken to suppress disulfide bond formation during in-gel digestion of proteins. The advantage of this method is that no blotting step is required for generating internal sequences and that extensive proteolysis occurs which closely resembles that resulting from solution digests. The method has been successfully used to generate internal sequence data from low microgram quantities of proteins excised from 2-dimensional Coomassie blue-stained gels. PMID:7710119

  15. X-ray CT dose in normoxic polyacrylamide gel dosimetry

    SciTech Connect

    Baxter, P.; Jirasek, A.; Hilts, M. [Department of Physics and Astronomy, University of Victoria, Victoria BC V8W 3P6 (Canada); Medical Physics, BC Cancer Agency-Vancouver Island Centre, Victoria BC V8R 6V5 (Canada)

    2007-06-15

    This study reports on the effects of x-ray CT dose in CT imaged normoxic polyacrylamide (nPAG) gel dosimeters. The investigation is partitioned into three sections. First, the CT dose absorbed in nPAG is quantified under a range of typical gel CT imaging protocols. It is found that the maximum absorbed CT dose occurs for volumetric imaging and is in the range of 4.6{+-}0.2 cGy/image. This does scales linearly with image averaging. Second, using Raman spectroscopy, the response of nPAG to CT imaging photon energies (i.e., 120-140 kVp) is established and compared to the well known dose response of nPAG exposed to 6 MV photons. It is found that nPAG exhibits a weaker response (per unit dose) to 140-kVp incident photons as compared to 6 MV incident photons (slopes m{sub 6MV}=-0.0374{+-}0.0006 Gy{sup -1} and m{sub 140kVp}=-0.016{+-}0.001 Gy{sup -1}). Finally, using the above data, an induced change in CT number ({delta}N{sub CT}) is calculated for nPAG imaged using a range of gel imaging protocols. It is found that under typical imaging protocols (120-140 kVp, 200 mAs, {approx}16-32 image averages) a {delta}N{sub CT}<0.2 H is induced in active nPAG dosimeters. This {delta}N{sub CT} is below the current limit of detectability of CT nPAG polymer gel dosimetry. Under expanded imaging protocols (e.g., very high number of image averages) an induced {delta}N{sub CT} of {approx}0.5 H is possible. In these situations the additional polymerization occurring in nPAG due to the imaging process may need to be accounted for.

  16. The gel edge electric field gradients in denaturing polyacrylamide gel electrophoresis.

    PubMed

    Desruisseaux, C; Slater, G W; Drouin, G

    1998-05-01

    It has previously been shown that zones of higher electric field form close to the loading end of the gel during denaturing polyacrylamide gel electrophoresis. Here we show that the field can reach up to three times its normal mean value a few cm in front of the loading wells when 44.5 mM Tris-44.5 mM boric acid-1 mM EDTA is used as the gel buffer. We also demonstrate that this electric field gradient is mostly due to the difference in ion transference numbers at the gel/buffer interface caused by the high viscosity of the urea solution contained in the gel. This field gradient leads to increased band widths and forces us to redefine both the electrophoretic mobility and the mean field intensity. We discuss some methods that can be used to minimize the effects of this gradient. PMID:9629888

  17. Ultrasonic Investigation of the Gelation Process of Poly(Acrylamide) Gels

    E-print Network

    Page, John

    Ultrasonic Investigation of the Gelation Process of Poly(Acrylamide) Gels Tomohisa Norisuye,*1 and attenuation has been investigated in-situ during the gelation process of polyacrylamide (PAAm) hydrogels a peak associated with the exothermic reaction for the PAAm gelation. The square of vp is proportional

  18. Polyacrylamide gel containing egg white as new model for irradiation experiments using focused ultrasound

    Microsoft Academic Search

    Kenji Takegami; Yukio Kaneko; Toshiaki Watanabe; Toshiyuki Maruyama; Yoichiro Matsumoto; Hirokazu Nagawa

    2004-01-01

    A polyacrylamide (PAA) gel containing egg white as a new model for irradiation experiments in high-intensity focused ultrasound HIFU is introduced. The gel is transparent except in thermally necrosed regions which are white. The model is similar to, and has the same benefits as, gels containing bovine serum albumin (BSA) protein, but egg is less expensive than BSA. The acoustic

  19. Soft-wet polyacrylamide gel beads with the imprinting of bovine serum albumin

    Microsoft Academic Search

    Xingshou Pang; Guoxiang Cheng; Yihua Zhang; Shulai Lu

    2006-01-01

    Protein-imprinted soft-wet polyacrylamide gel beads were synthesized via inverse suspension polymerization, using bovine serum albumin (BSA) as template. The gel beads had macroporous structure and were suited to let the protein pass in and out. The adsorption capacity of BSA-imprinted gel beads was almost four times as much as that of non-imprinted gel beads. The selectivity test of imprinted gel

  20. Photo-initiated cross-linked polyacrylamide gels for microdevice electrophoresis 

    E-print Network

    Agrawal, Shilpa

    2005-08-29

    Photo-polymerized cross-linked polyacrylamide gels are becoming increasingly important for use in micro-fabricated DNA electrophoresis systems because they allow a concentrated sieving matrix to be precisely positioned at any location within a...

  1. Photo-initiated cross-linked polyacrylamide gels for microdevice electrophoresis

    E-print Network

    Agrawal, Shilpa

    2005-08-29

    Photo-polymerized cross-linked polyacrylamide gels are becoming increasingly important for use in micro-fabricated DNA electrophoresis systems because they allow a concentrated sieving matrix to be precisely positioned at any location within a...

  2. Proton Diffusion and T 1Relaxation in Polyacrylamide Gels: A Unified Approach Using Volume Averaging

    Microsoft Academic Search

    Brigita Penke; Stephen Kinsey; Stephen J. Gibbs; Timothy S. Moerland; Bruce R. Locke

    1998-01-01

    The structure of polyacrylamide gels was studied using proton spin–lattice relaxation and PFG diffusion methods. Polyacrylamide gels, with total polymer concentrations ranging from 0.25 to 0.35 g\\/ml and crosslinker concentrations from 0 to 10% by weight, were studied. The data showed no effect of the crosslinker concentration on the diffusion of water molecules. The Ogston–Morris and Mackie–Meares models fit the

  3. A versatile polyacrylamide gel electrophoresis based sulfotransferase assay

    PubMed Central

    2010-01-01

    Background Sulfotransferases are a large group of enzymes that regulate the biological activity or availability of a wide spectrum of substrates through sulfation with the sulfur donor 3'-phosphoadenosine-5'-phosphosulfate (PAPS). These enzymes are known to be difficult to assay. A convenient assay is needed in order to better understand these enzymes. Results A universal sulfotransferase assay method based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is described. This assay has been successfully applied to substrates as small as ?-naphthol and as big as proteoglycans. As examples, we present the assays for recombinant human CHST4, TPST1, CHST3 and HS6ST1. In order to assess whether a small molecule can be applicable to this type of assay, a method to estimate the relative mobility of a molecule to PAPS is also presented. The estimated relative mobilities of various sulfated small molecules generated by SULT1A1, SULT1E1, SULT2A1 and CHST4 are in the range of ± 0.2 of the actual relative mobilities. Conclusion The versatility of the current method comes from the ability that SDS-PAGE can separate proteins and small molecules according to different parameters. While mobilities of proteins during SDS-PAGE are inversely related to their sizes, mobilities of small molecules are positively related to their charge/mass ratios. The predicted relative mobility of a product to PAPS is a good indicator of whether a sulfotransferase can be assayed with SDS-PAGE. Because phosphorylation is most similar to sulfation in chemistry, the method is likely to be applicable to kinases as well. PMID:20146816

  4. Separation and determination of some stereoisomers by capillary gel electrophoresis with cyclodextrin incorporated in polyacrylamide gel.

    PubMed

    Lin, J M; Nakagama, T; Okazawa, H; Wu, X Z; Hobo, T

    1996-02-01

    Capillary gel electrophoresis (CGE) was successfully applied to the separation of optically active isomers and position isomers by incorporating a suitable cyclodextrin chiral selector in polyacrylamide gel. A commercially available ss-cyclodextrin (ss-CD) was used for enantioselectivity towards o-, m- and p-nitrobenzoic acid, o-, m- and p-hydroxybenzoic acid, o-, m- and p-toluic acid and the optical isomers of dansyl-D,L-leucine and R,S-1,1'-binaphthyl-2,2-dihydrogenphosphate. Especially the effect of organic solvents, such as acetonitrile, methanol, dimethylsulphoxide and others were examined in detail. The resolution varied to some extent with the addition of the organic solvent to the polyacrylamide gel and the running buffer solution. The possible mechanism has also been discussed. In addition, quantitative aspects of the separation of stereoisomers using CGE have been studied, showing that both the resolution and accuracy of the determinations were affected by the ratio of the enantiomers. PMID:15048432

  5. The use of preparative polyacrylamide gel electrophoresis and electroelution for purification of mucus glycoproteins.

    PubMed

    Paszkiewicz-Gadek, A; Gindzie?ski, A; Porowska, H

    1995-04-10

    This paper describes a novel technique for purifying glycoproteins from porcine gastric mucus by preparative polyacrylamide gel electrophoresis and electroelution. The method is based on the observation that the high-molecular-weight buffer/SDS-soluble mucins do not penetrate through the polyacrylamide gel, but remain on the gel surface. Mucus solution extracted with 6 M urea was fractionated on Sepharose CL-2B column and Vo peak mucin was submitted to purification by preparative polyacrylamide gel electrophoresis (22 h). Nonpenetrated mucin layer was electroeluted from the gel after the reversing of electrode polarity (3 h). A comparison of mucin preparations purified by our method and by CsCl density gradient centrifugation indicated that the GalNAc/protein and GalNAc/DNA ratios were three times higher than those of the first method. The method is a relatively short and efficient procedure and yields pure mucin preparation free of contaminating proteins and nucleic acids. PMID:7540808

  6. Effects of degree of hydrolysis and shear on gelation reaction kinetics and gel strength. [Polyacrylamides

    SciTech Connect

    Gao, Hong W.

    1991-02-01

    Gelation tests were conducted to investigate the effect of the degree of hydrolysis on gelation reaction kinetics and gel strength using four low-molecular-weight polyacrylamides (MW = 400,000 daltons), which were 10% (HPAM1-10), 20% (HPAM1-20), 30% (HAPM1-30), and 40% (HPAM-40) hydrolyzed, and Cr-3 (pH = 4.8) and Al-3 (pH = 7.0) crosslinkers. Results showed that for polymer/Cr-3 gel systems, samples prepared with a low-molecular-weight polyacrylamide polymer, which was 20% hydrolyzed, gelled at a faster rate and retained higher gel strength than those prepared with a low-molecular-weight polyacrylamide polymer, which was 10% hydrolyzed. Under the screening condition, no viscosity enhancement was observed in samples prepared with polymers having a degree of hydrolysis equal to or greater than 30%. For polymer/Al-3 gel systems, samples prepared with a low-molecular-weight polyacrylamide polymer, which was 20% hydrolyzed, gelled at the fastest rate and retained the strongest gel strength among the polymer/Al-3 gel systems prepared with four low-molecular-weight polyacrylamide polymers, which were 10, 20, 30, and 40% hydrolyzed, respectively. Gelation tests of gel systems in glass bead packs showed that high shear favored the gelation of a gel system that had a fast rate of gelation, but had an adverse effect on the gelation of three gel systems that had a slow rate of gelation. Weak gels were found to be injectable through porous media. Weak gels were degradable under high shear condition and regained viscosity under low shear conditions. 17 refs., 8 figs., 1 tab.

  7. Silver-staining of proteins in polyacrylamide gels: a general overview

    Microsoft Academic Search

    Thierry Rabilloud; L. Vuillard; C. Gilly; J. J. Lawrence

    2009-01-01

    On the basis of the physico-chemical principles underlying silver-staining of proteins, which are recalled in this paper, several methods of silver-staining of proteins after SDS electrophoresis in polyacrylamide gels or isoelectric focusing were tested. The most valuable protocols are presented in this report, including standard methods for unsupported gels and new methods devised for thin (0.5 mm) supported gels for

  8. Effect of pH and acrylamide concentration on the separation of lipopolysaccharides in polyacrylamide gels

    Microsoft Academic Search

    Lorraine G. M. Duchesne; Joseph S. Lam; Leslie A. MacDonald; Christopher Whitfield; Andrew M. Kropinski

    1988-01-01

    The technique of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to separate the O-antigen of three strains ofPseudomonas aeruginosa, two strains, ofSalmonella typhimurium, and one strain ofEscherichia coli. No significant difference in separation and migration rate of sample was seen at the various acrylamide gel concentrations used. However, samples electrophoresed through acrylamide running gels at pH 6.8 migrated faster

  9. Drying of Polyacrylamide Composite Gels Formed with Various Kappa Carrageenan Content

    Microsoft Academic Search

    Gül?en A. Evingür; Önder Pekcan

    Drying of polyacrylamide (PAAm)-?-carrageenan (?C) composite gels were monitored by using steady-state fluorescence technique.\\u000a Disc shaped gels were formed from acrylamide (AAm) and N, N?- methylenebisacrylamide(Bis) with various ?- carrageenan (?C)\\u000a contents by free radical crosslinking copolymerization in water. Pyranine (P) was doped as a fluorescence probe, and scattered light, I\\u000a \\u000a sc\\u000a , and fluorescence intensities, I, were monitored during

  10. Migration of Implants: A Problem with Injectable Polyacrylamide Gel in Aesthetic Plastic Surgery

    Microsoft Academic Search

    Ning-xin Cheng; Shi-liang Xu; Hui Deng; Xiao-bang Ding; Xiao-man Zhang; Dai-hong Wu; Hong Zhong; Zi-hong Sun

    2006-01-01

    Polyacrylamide gel (PAAG) has been used as a soft tissue filler material for cosmetic purposes in Europe and China since 1997.\\u000a The various complications of PAAG have been reported. A total of 15 patients who received PAAG injections at other institutions\\u000a were treated for gel migration in the authors’ hospitals. During treatment, the authors found that the injected PAAG had

  11. Identification and Characterization of Species of the Family Bacteriodaceae by Polyacrylamide Gel Electrophoresis

    Microsoft Academic Search

    Ann Strom; J. K. Dyer; Connell Marsh; Jack L. Tribble

    1976-01-01

    A method is described for identifying and characterizing microorganisms of the family Bacteroidaceae by their protein profiles. Protein profiles of six species and several strains of this family were compared using gradient polyacrylamide gel electrophoresis in the slab form. The protein profiles were sufficiently distinct and reproducible to allow identification of species, subspecies, and even minor strain differences. This technique

  12. Imaging findings of breast augmentation with injected hydrophilic polyacrylamide gel: Patient reports and literature review

    Microsoft Academic Search

    Najoua Ben Khedher; Julie David; Isabelle Trop; Suzanne Drouin; Laurence Peloquin; Lucie Lalonde

    2011-01-01

    Hydrophilic polyacrylamide gel (PAAG) is a nonresorbable soft tissue filler that has been used as implant material for breast augmentation in some countries, particularly from the Asian continent. Many complications associated with hydrogel use have been reported in the clinical literature including inflammation, persistent mastodynia, formation of multiple lumps, poor cosmetic results, glandular atrophy, and significant spread of hydrogel into

  13. Silver staining of proteins in polyacrylamide gels Mireille Chevallet, Sylvie Luche and Thierry Rabilloud*

    E-print Network

    Paris-Sud XI, Université de

    Silver staining of proteins in polyacrylamide gels Mireille Chevallet, Sylvie Luche and Thierry author email: thierry.rabilloud@cea.fr Phone +33 438 783 212, Fax : +33 438 789 803 Abstract Silver. The sequential phases of silver staining are protein fixation, then sensitization, then silver impregnation

  14. Identification of Frankia Strains by Two-Dimensional Polyacrylamide Gel Electrophoresis

    PubMed Central

    Benson, David R.; Buchholz, S. E.; Hanna, D. G.

    1984-01-01

    Fifteen Frankia strains from five different plant species were analyzed by two-dimensional polyacryl-amide gel electrophoresis to determine their relatedness by comparing the polypeptide patterns obtained. Three major subgroups (A, C, and D) were found in the Alnus-Comptonia-Myrica cross-inoculation group. An isolate from Purshia tridentata had a unique protein pattern and represents a distinct group of frankiae. Members of group A were isolated from root nodules of Alnus incana subsp. rugosa and Alnus viridis subsp. crispa. Group C organisms were from A. incana subsp. rugosa and Comptonia peregrina nodules, and group D organisms were from A. incana subsp. rugosa, A. viridis subsp. cripsa, and Myrica pensylvanica root nodules. Isolates from each gel group were obtained at several widely separated geographical locations. The results indicate that two-dimensional polyacrylamide gel electrophoresis is useful for identifying Frankia isolates. Images PMID:16346488

  15. Identification of frankia strains by two-dimensional polyacrylamide gel electrophoresis.

    PubMed

    Benson, D R; Buchholz, S E; Hanna, D G

    1984-03-01

    Fifteen Frankia strains from five different plant species were analyzed by two-dimensional polyacryl-amide gel electrophoresis to determine their relatedness by comparing the polypeptide patterns obtained. Three major subgroups (A, C, and D) were found in the Alnus-Comptonia-Myrica cross-inoculation group. An isolate from Purshia tridentata had a unique protein pattern and represents a distinct group of frankiae. Members of group A were isolated from root nodules of Alnus incana subsp. rugosa and Alnus viridis subsp. crispa. Group C organisms were from A. incana subsp. rugosa and Comptonia peregrina nodules, and group D organisms were from A. incana subsp. rugosa, A. viridis subsp. cripsa, and Myrica pensylvanica root nodules. Isolates from each gel group were obtained at several widely separated geographical locations. The results indicate that two-dimensional polyacrylamide gel electrophoresis is useful for identifying Frankia isolates. PMID:16346488

  16. Dna electrophoresis in photopolymerized polyacrylamide gels on a microfluidic device

    E-print Network

    Lo, Chih-Cheng

    2009-05-15

    and encourage- ment, and my wife and daughter for their patience and love. vii NOMENCLATURE %T Monomer concentration %C Crosslinker concentration bp base pairs BRM Biased reptation model BRF Biased reptation with fluctuations DNA... in Long Ranger ? poly- acrylamide sequencing gels. ................................................................ 109 V-2 Mobility fits for dsDNA. (a) Finish line mode. Run conditions: 0.5X TBE, L = 0.5 cm, E = 15 V/cm, and T = 22 ?C. (b...

  17. Internal amino acid sequence analysis of proteins separated by gel electrophoresis after tryptic digestion in polyacrylamide matrix

    Microsoft Academic Search

    Ch. Eckerskorn; F. Lottspeich

    1989-01-01

    Summary  A method is described for obtaining peptide fragments for sequence analysis from microquantities of proteins separated by 1- or 2-dimensional polyacrylamide gel electrophoresis. After separation by electrophoresis, the proteins were stained with Coomassie Blue and excised. Proteolytic digestion with trypsin was performed directly in the polyacrylamide matrix. The resulting peptide fragments were eluted, separated by reversed phase HPLC, collected and

  18. Rapid Separation and Quantification of Major Caseins and Whey Proteins of Bovine Milk by Polyacrylamide Gel Electrophoresis

    Microsoft Academic Search

    K. F. Ng-Kwai-Hang; E. M. Kroeker

    1984-01-01

    A rapid polyacrylamide gel electro- phoretic method was developed for separating and quantifying major pro- teins in casein and whey protein fractions of bovine milk. For casein separation, best results were achieved by an 8% poly- acrylamide gel containing 4 M urea and a top layer of large pore sample gel; for whey protein the most_ satisfactory separation was with

  19. Resolving Acetylated and Phosphorylated Proteins by Neutral Urea Triton-Polyacrylamide Gel Electrophoresis, NUT-PAGE

    PubMed Central

    Buehl, Christopher J.; Deng, Xiexiong; Liu, Mengyu; Hovde, Stacy; Xu, Xinjing; Kuo, Min-Hao

    2014-01-01

    Protein acetylation and phosphorylation can be key modifications that regulate both normal and pathological protein functions. Current gel systems used to analyze modified proteins require either expensive reagents or time–consuming second dimension electrophoresis. In this manuscript, we present a neutral pH gel system that allows the analysis of acetylated and phosphorylated proteins. This neutral pH urea Triton-polyacrylamide gel electrophoresis system, or NUT-PAGE, separates proteins based on their charge at pH 7 and generates discrete bands from each acetylated and phosphorylated species. In addition, the gel is composed of common and inexpensive laboratory reagents, and requires only a single dimension of electrophoresis. We are able to demonstrate the effectiveness of this system by analyzing phosphorylated species of an acidic protein, ?-synuclein, and both acetylated and phosphorylated species of a basic protein, histone H3. NUT-PAGE thus provides a cost-effective alternative to resolving acetylated and phosphorylated proteins, and potentially proteins with other post-translational modifications that alter net charge. Method Summary Here we present a single-dimension neutral pH urea Triton-polyacrylamide gel electrophoresis (NUT-PAGE) system affording high-resolution separation of acetylated and phosphorylated proteins. PMID:25109292

  20. 'Catalysts' for polyacrylamide gel polymerization and detection of proteins by silver staining.

    PubMed

    Hochstrasser, D F; Merril, C R

    1988-01-01

    The crosslinker diacrylyl-piperazine produces polyacrylamide gels which display improved electrophoretic separation of proteins and better physical strength. It also produces gels with improved detection of proteins by ammoniacal silver staining by reducing the background. This reduced background provided us with an opportunity to investigate residual background staining caused by the catalytic reagents utilized in the polymerization of acrylamide gels. The commonly used catalyst system, tetramethyl-ethylenediamine and ammonium persulfate was shown to be responsible for the yellow staining background found after a prolonged development time with silver staining. An alternate catalyst system has been designed to decrease further the formation of this background staining. Dimethyl-piperazine or tetramethylethylenediamine, potassium or ammonium persulfate, and sodium thiosulfate are shown to provide for gels which have excellent mechanical and staining characteristics. These catalytic systems produce little background staining despite prolonged development time with the ammoniacal silver stain, and they reduce background staining with the dichromate silver stain. PMID:2484987

  1. Viscometric measurement of chromium(III)-polyacrylamide gels by Weissenberg rheogoniometer

    SciTech Connect

    Aslam, S.; Vossoughi, S.; Willhite, G.P.

    1984-04-01

    Gelled polymers are being used increasingly to modify the movement of injected fluids in secondary and enhanced oil recovery processes. A common gelation process involves the reduction of Cr(VI) to Cr(III) in the presence of polyacrylamide. The Cr(III) reacts or interacts with the polymer to form a gel network. Although correlations of gelation time with principal process variables have been obtained, viscometric data have not been reported during or after gelation. These data are needed for fluid flow calculations in surface equipment and estimation of flow behavior in reservoir rocks. A Weissenberg Rheogoniometer, with cone and plate geometry, was used to obtain viscometric data for the gelation of polyacrylamide and chromium (III). Solutions consisting of polyacrylamide polymer, sodium dichromate-dihydrate and sodium bisulfite were gelled under a steady shear field at constant temperature. The shear stress vs. time profile for the gelation process was interpreted to define a gelation time and to determine the apparent viscosity of the gelled fluid. The gelation time decreased as the applied shear rate increased up to about 14.25 sec/sup -1/ and was affected by shear rate history. Viscometric properties of the gelled solutions were determined. Apparent viscosity of the gelled solutions decreased as the shear rate under which they were formed increased. Post gelation studies indicated that gels exhibited a residual or yield stress at zero shear rate and behaved as Bingham plastics under steady shear. Gels formed at low shear rates were more viscous than gels formed at high shear rates. However, the structure of these gels was susceptible to shear degradation.

  2. Application of optical methods for dose evaluation in normoxic polyacrylamide gels irradiated at two different geometries

    NASA Astrophysics Data System (ADS)

    Adliene, D.; Jakstas, K.; Vaiciunaite, N.

    2014-03-01

    Normoxic gels are frequently used in clinical praxis for dose assessment or 3-D dose imaging in radiotherapy due to their relative simple manufacturing process under normal atmospheric conditions, spatial stability and well expressed modification feature of physical properties which is related to radiation induced polymerization of gels. In this work we have investigated radiation induced modification of the optical properties of home prepared normoxic polyacrylamide gels (nPAG) in relation to polymerization processes that occur in irradiated gels. Two irradiation geometries were used for irradiation of gel samples: broad beam irradiation geometry of teletherapy unit ROKUS-M with a 60Co source and point source irradiation geometry using 192Ir source of high dose rate afterloading brachytherapy unit MicroSelectron v2 which was inserted into gel via 6 Fr (2 mm thick) catheter. Verification of optical methods: UV-VIS spectrometry, spectrophotometry, Raman spectroscopy for dose assessment in irradiated gels has been performed. Aspects of their application for dose evaluation in gels irradiated using different geometries are discussed. Simple pixel-dose based photometry method also has been proposed and evaluated as a potential method for dose evaluation in catheter based interstitial high dose rate brachytherapy.

  3. Resurrexit, sicut dixit, alleluia. Snake venomics from a 26-year old polyacrylamide focusing gel.

    PubMed

    Righetti, Pier Giorgio; Lomonte, Bruno; Calvete, Juan J

    2012-01-01

    A 26-year-old dried polyacrylamide gel, cast in presence of an immobilized pH gradient and containing focused proteins from the venoms of a northern black-tailed rattlesnake (Crotalus molossus molossus), and of a western diamondback rattlesnake (Crotalus atrox) has been screened in order to see the feasibility of extracting the proteins, analyzing them by mass spectrometry (MS) and assessing their integrity. Nine gel bands were excised along the pH 3-10 gradient and the gel segments reswollen in warm acetonitrile. Upon digestion and MS analysis, all the bands could be identified and attributed to the respective venoms of the two rattlesnake species. Although a few peptides exhibited modified amino acids, the proteins were found to be well preserved even upon such a long storage at room temperature. The present data suggest the feasibility of identifying proteins from very old samples trapped in polyacrylamide gels, and analyzed in a pre-mass spectrometry era, thus of uncertain identity. PMID:21985938

  4. Preparation and Shear Modulus of Polyacrylamide Gels as Nerve Cell Culture

    NASA Astrophysics Data System (ADS)

    Perrault, Cécile M.; Juncker, David; Park, Hee Eon

    2008-07-01

    In the recent years, physical interactions between cells and their mechanical environment have been recognized for their influence on cellular functions, such as differentiation, motility, and growth. The importance of this phenomenon on neural cells is being investigated here in order to evaluate the optimal mechanical environment for their maximum growth. We prepared polyacrylamide gel as a culture medium for the nerve cell growth. Since we hypothesize that the shear modulus of the medium, which is fully saturated with water, plays an important role in the cell growth, we prepared gels having different shear modulus by varying the ratio of the polymerizing agents and the thickness of the medium was controlled by molding. It is the key issue to determine the shear modulus of the gels to study the effect of the modulus on the nerve cell growth. However, because the physical properties of the gels should be measured when those are saturated with water, but there should be no water layer on the surface to prevent slip in rheometers, new techniques were developed to dissolve these issues. This poster will present those rheological techniques, preparation of the gels, and the effect of shear modulus of the gel medium on the growth of nerve cells.

  5. Polyacrylamide Gel Treatment of Antiretroviral Therapy-induced Facial Lipoatrophy in HIV Patients

    Microsoft Academic Search

    Samreen Mansor; Vibeke Bro Breiting; Karin Dahlstrøm; Åse Bengård Andersen; Ove Andersen; Lise Hanne Christensen

    Background  Today, highly active antiretroviral therapy is lifesaving for most HIV-infected patients, but the treatment can result in\\u000a facial lipoatrophy, which changes the face so radically that patients may develop severe psychological and social problems.\\u000a Since 2001 polyacrylamide gel (PAAG) has been used successfully in HIV patients abroad. This article describes the results\\u000a of a Danish study.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Forty HIV patients recruited

  6. Enzymatic protein digestion using a dissolvable polyacrylamide gel and its application to mass spectrometry-based proteomics.

    PubMed

    Takemori, Nobuaki; Takemori, Ayako; Ishizaki, Jun; Hasegawa, Hitoshi

    2014-09-15

    Enzymatic protein digestion in polyacrylamide gel has been used for sample pretreatment in mass spectrometry-based proteomics due to its effectiveness in removing contaminants that interfere with sample ionization. However, the difficulty of recovering the digested peptides from the solid gel matrix has been a drawback of this method. Here we have developed a novel in-gel digestion method to enhance peptide recovery using a dissolvable, bis-acrylylcystamine (BAC)-crosslinked polyacrylamide gel. After enzymatic protein digestion in BAC gel, we completely dissolved the gel by reductive treatment with tris-(2-carboxyethyl) phosphine to release the digested peptides from the gel. Our analysis revealed that the reductive dissolution of the BAC gel enhances the peptide recovery, which has a significantly higher protein identification capability than the conventional method, using an insoluble polyacrylamide gel. In addition, protein samples trapped in dehydrated BAC gel were stable at room temperature and reproducible sample recovery was obtained after storage for one week. These results indicate that the proposed method could be an effective tool for conducting sample pretreatment for mass spectrometry-based protein analysis. PMID:25063926

  7. Characterisation of soil-bound residue fractions of the fungicide dithianon by gel permeation chromatography and polyacrylamide gel electrophoresis.

    PubMed

    Wanner, U; Burauel, P; Führ, F

    2000-04-01

    The degradation of the (14)C-labelled fungicide dithianon in an orthic luvisol was investigated under standardized conditions in comparison to stimulated microbial activity by an amendment of maize straw. The compound is characterized by mineralization losses of approximately 33% and the formation of non-extractable bound residues of approximately 63% in 64 days. Despite the major role of microorganisms in mineralizing this compound, the formation of bound residues is not biotically induced. Gel permeation chromatography and polyacrylamide gel electrophoresis, as different size separation techniques of the humic acids fractions, showed differences in the distribution patterns of non-extractable residues depending on the addition of straw material. The results presented support the existence of humic substances in soil as a micellar system rather than as a biopolymer. PMID:15092966

  8. MALDI analysis of proteins after extraction from dissolvable ethylene glycol diacrylate cross-linked polyacrylamide gels.

    PubMed

    Papasotiriou, Dimitrios G; Markoutsa, Stavroula; Gorka, Jan; Schleiff, Enrico; Karas, Michael; Meyer, Bjoern

    2013-09-01

    Although the extraction of intact proteins from polyacrylamide gels followed by mass spectrometric molecular mass determination has been shown to be efficient, there is room for alternative approaches. Our study evaluates ethylene glycol diacrylate, a cleavable cross-linking agent used for a new type of dissolvable gels. It attains an ester linkage that can be hydrolyzed in alkali conditions. The separation performance of the new gel system was tested by 1D and 2D SDS-PAGE using the outer chloroplast envelope of Pisum sativum as well as a soluble protein fraction of human lymphocytes, respectively. Gel spot staining (CBB), dissolving, and extracting were conducted using a custom-developed workflow. It includes protein extraction with an ammonia-SDS buffer followed by methanol treatment to remove acrylamide filaments. Necessary purification for MALDI-TOF analysis was implemented using methanol-chloroform precipitation and perfusion HPLC. Both cleaning procedures were applied to several standard proteins of different molecular weight as well as 'real' biological samples (8-75 kDa). The protein amounts, which had to be loaded on the gel to detect a peak in MALDI-TOF MS, were in the range of 0.1 to 5 ?g, and the required amount increased with increasing mass. PMID:23775326

  9. A single nucleotide polymorphism genotyping method using phosphate-affinity polyacrylamide gel electrophoresis.

    PubMed

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

    2007-02-15

    To date, various methods have been developed to facilitate the genotyping of a single nucleotide polymorphism (SNP) for aiding in the diagnosis and treatment of inherited diseases. The most commonly used method for SNP genotyping is an allele-specific hybridization procedure using an expensive fluorochrome-labeled oligonucleotide probe and a specialized fluorescence analyzer. Here, we introduce a simple and reliable genotyping method using a 1:1 mixture of 5'-phosphate-labeled and nonlabeled allele-specific polymerase chain reaction (PCR) primers. The method is based on the difference in mobility of the phosphorylated and nonphosphorylated PCR products (in the same number of basepairs) on phosphate-affinity polyacrylamide gel electrophoresis. The phosphate-affinity site is a polyacrylamide-bound dinuclear zinc(II) complex, which preferentially captures the 5'-phosphate-labeled allele-specific product compared with the corresponding nonlabeled product. The obtained DNA migration bands can be visualized by ethidium bromide staining. We demonstrate the genotyping of a SNP reported in a human cardiac sodium channel gene, SCN5A, using this novel procedure. PMID:17196923

  10. Performing Isoelectric Focusing and Simultaneous Fractionation of Proteins on A Rotary Valve Followed by Sodium Dodecyl – Polyacrylamide Gel Electrophoresis

    PubMed Central

    Wang, Wei; Lu, Joann J.; Gu, Congying; Zhou, Lei; Liu, Shaorong

    2013-01-01

    In this technical note, we design and fabricate a novel rotary valve and demonstrate its feasibility for performing isoelectric focusing and simultaneous fractionation of proteins, followed by sodium dodecyl – polyacrylamide gel electrophoresis. The valve has two positions. In one position, the valve routes a series of capillary loops together into a single capillary tube where capillary isoelectric focusing (CIEF) is performed. By switching the valve to another position, the CIEF-resolved proteins in all capillary loops are isolated simultaneously, and samples in the loops are removed and collected in vials. After the collected samples are briefly processed, they are separated via sodium dodecyl – polyacrylamide gel electrophoresis (SDS-PAGE, the 2nd-D separation) on either a capillary gel electrophoresis instrument or a slab-gel system. The detailed valve configuration is illustrated, and the experimental conditions and operation protocols are discussed. PMID:23819755

  11. Staining of proteins on SDS polyacrylamide gels and on nitrocellulose membranes by Alta, a colour used as a cosmetic

    Microsoft Academic Search

    Jayanta K. Pal; Dhanashri Godbole; Kiran Sharma

    2004-01-01

    We describe here the use of Alta, a pre-existing scarlet-red stain of cosmetic use, for staining proteins on sodium dodecyl sulfate (SDS) polyacrylamide gels, as well as for a single step staining of gels and nitrocellulose membranes during Western blot analysis. This stain, which is composed of 0.8% Crocein scarlet (brilliant crocein) and 0.2% Rhodamine B, is inexpensive, easy to

  12. Electrophoresis of /sup 35/S-labeled proteoglycans of polyacrylamide-agarose composite gels and their visualization by fluorography

    SciTech Connect

    Carney, S.L.; Bayliss, M.T.; Collier, J.M.; Muir, H.

    1986-01-01

    Techniques for the electrophoresis of /sup 35/S-labeled proteoglycans on polyacrylamide-agarose gel slabs and subsequent fixation, impregnation, and fluorography of such electrophoretograms have been developed. The procedure permits the examination of newly synthesized proteoglycan subspecies using a rapid technique, previously unavailable for these labeled molecules.

  13. Composition of the fractions separated by polyacrylamide gel electrophoresis of the lipopolysaccharide of a marine bacterium.

    PubMed Central

    DiRienzo, J M; MacLeod, R A

    1978-01-01

    The sugar composition of lipopolysaccharide (LPS) isolated from whole cells of Alteromonas haloplanktis 214 (previously referred to as marine pseudomonas B-16, ATCC 19855), variant 3, of the lipid A, core, and side-chain fractions derived from it, and of the LPS fractions (LPS I, II, and III) obtained by subjecting it to preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis has been determined. Conditions optimum for the release of constituent monosaccharides by hydrolysis were established. Sugars were quantitated by gas-liquid chromatography of their alditol acetate derivatives. Lipid A was detected by gel electrophoresis and by the spectral shift obtained with a carbocyanin dye. A comparison of the molar ratios of the various fractions suggest that LPS III is an LPS molecule lacking an O-antigenic side chain, whereas LPS I and II are LPS molecules differing in side-chain composition. LPS I may be a mixture of two LPS species. In double immunodiffusion experiments using anti-whole-cell serum, LPS I and II showed a homologous cross-reaction with isolated whole-cell LPS. LPS III as well as lipid A, core, and side-chain fractions failed to give rise to precipitin lines. Images PMID:101510

  14. Polyacrylamide-gel electrophoresis and Alcian Blue staining of sulphated glycosaminoglycan oligosaccharides.

    PubMed Central

    Cowman, M K; Slahetka, M F; Hittner, D M; Kim, J; Forino, M; Gadelrab, G

    1984-01-01

    Oligosaccharide fragments of glycosaminoglycans may be separated for rapid analysis by electrophoresis through a 10% polyacrylamide matrix. An extensive ladder-like set of bands is observed for partial testicular hyaluronidase digests of chondroitin 4- or 6-sulphate, and for dermatan sulphate. Co-electrophoresis of purified oligosaccharides has established that the major bands of these patterns represent fragments differing in chain length by one disaccharide unit, with the smallest fragments having the greatest mobility. Additional minor bands, representing heterogeneity in the repeating unit structure, are also observed. There are slight differences in the mobilities of oligosaccharides derived from the three major types of sulphated glycosaminoglycans. Alcian Blue is employed for visualization of the digest fragments. Sample loads of 5-10 micrograms per band appear optimum. The smallest oligosaccharide which may be stained by this method is the hexasaccharide. After consideration of this effect, a good correlation is found to exist between densitometric scans of the gel-electrophoretic patterns and gel-filtration chromatographic profiles based on uronic acid concentration. Images Fig. 1. Fig. 4. Fig. 5. PMID:6433889

  15. Photocurrent measurements of the purple membrane oriented in a polyacrylamide gel.

    PubMed Central

    Liu, S Y; Ebrey, T G

    1988-01-01

    When illuminated, oriented purple membranes isolated from Halobacterium halobium give a photoelectric effect. The frequency response of a photocurrent measuring system for purple membranes oriented and immobilized in a polyacrylamide gel is analyzed from DC to 100 MHz. The waveform of the photocurrent can depend on both the sample conditions (including bathing solution) and the measuring system (electrode and ammeter) at both the low and high frequency ends. In the DC-1 kHz range (millisecond signals), the apparent lifetime of the photocurrent component is distorted if the electrode is not platinized and if the conductivity of the bathing solution is not low. In the 1 kHz to 1 MHz range (microsecond signals), the frequency response is flat under most conditions. In the MHz range (nanosecond signals), the apparent lifetime of the photocurrent component will be distorted if the conductivity of the bathing solution is not high and if the input impedance of the ammeter is not low and constant throughout the frequency range. With our optimized apparatus, we could measure the photocurrent components from oriented purple membrane with lifetimes from 70 ms to 32 ns without distortion by the measuring system. PMID:3207828

  16. Microscopic agglutination and polyacrylamide gel electrophoresis analyses of oral anaerobic spirochetes.

    PubMed Central

    Tall, B D; Nauman, R K

    1986-01-01

    Microscopic agglutination (MA) analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to determine strain and species similarities and dissimilarities among three species of oral anaerobic spirochetes, Treponema denticola, Treponema pectinovorum, and Treponema vincentii. The MA analysis revealed a diversity of serologic reactivity or sharing of common antigens within each species. However, there was no cross-reactivity or sharing of common antigens among the three species. Distinct SDS-PAGE whole-cell electrophoretograms for each species were obtained. The banding patterns for 16 T. denticola strains revealed 30 distinct proteins, while the banding patterns for 5 strains of T. pectinovorum and 2 strains of T. vincentii revealed 26 and 35 distinct proteins, respectively. Analysis of the electrophoretograms showed that their respective banding patterns could be used to distinguish the three species from one another. In addition, strain differences within each species could be detected. There was a correlation between MA analysis and SDS-PAGE analysis. It is thus suggested that both MA and SDS-PAGE analysis be included in classification schemes for the identification of oral spirochetes. Images PMID:3745424

  17. Human liver alkaline phosphatase purified by affinity chromatography, ultracentrifugation and polyacrylamide-gel electrophoresis.

    PubMed Central

    Latner, A L; Hodson, A W

    1976-01-01

    A method is presented for the preparation of human liver alkaline phosphatase (orthophosphoric monoester phosphohydrolase, EC 3.1.3.1). The method gives a purification factor of 12.5 X 10(3) over the initial aq. butan-1-ol extract, a recovery of 6.0% and a specific activity for the preparation of 1450-1550 units/mg of protein, 1 unit being defined as the amount of enzyme catalysing the hydrolysis of 1mumol of p-nitrophenyl phosphate/min at 35 degrees C in 0.1 M-2-amino-2-methylpropan-1-ol/HCl buffer, pH 10.5, containing 10mM-p-nitrophenyl phosphate. Homogeneity was studied by ultracentrifugation, by immunoelectrophoresis and by polyacrylamide-gel electrophoresis. A single contaminating protein was present which was less than 5% of the total. Ultracentrifugation and equilibrium-gradient-pore electrophoresis techniques indicated a mol.wt. of 156000 and 160000 respectively. Equilibrium-gradient-pore electrophoresis indicated that the alkaline phosphatase molecule is possibly a dimer, comprising two subunits of about 80000 mol.wt. Amino acid analysis proved remarkably similar to that for alkaline phosphatase from other sources, regardless of species. Images PLATE 1 PMID:1008827

  18. The many applications of acid urea polyacrylamide gel electrophoresis to studies of tRNAs.

    PubMed Central

    Köhrer, Caroline; RajBhandary, Uttam L.

    2008-01-01

    Here we describe the many applications of acid urea polyacrylamide gel electrophoresis (acid urea PAGE) followed by Northern blot analysis to studies of tRNAs. Acid urea PAGE allows the electrophoretic separation of different forms of a tRNA, discriminated by changes in bulk, charge, and/or conformation that are brought about by aminoacylation, formylation, or modification of a tRNA. Among the examples described are (i) analysis of the effect of mutations in the Escherichia coli initiator tRNA on its aminoacylation and formylation; (ii) evidence of orthogonality of suppressor tRNAs in mammalian cells and yeast; (iii) analysis of aminoacylation specificity of an archaeal prolyl-tRNA synthetase that can aminoacylate archaeal tRNAPro with cysteine, but does not aminoacylate archaeal tRNACys with cysteine; (iv) identification and characterization of the AUA-decoding minor tRNAIle in archaea; and (v) evidence that the archaeal minor tRNAIle contains a modified base in the wobble position different from lysidine found in the corresponding eubacterial tRNA. PMID:18241794

  19. Silver staining method for DNA in polyacrylamide gels using eriochrome black T as a silver-ion sensitizer.

    PubMed

    Hwang, Sun-young; Jin, Li-tai; Yoo, Gyurng-soo; Choi, Jung-Kap

    2006-05-01

    A sensitive silver staining method using eriochrome black T as a silver-ion sensitizer for DNA detection in polyacrylamide gels was developed. The sensitivity of this staining method was significantly improved by the new silver-ion sensitizer containing a diazo group, which has reducing power. The staining method lasted a total of approximately 15 min following a fixing step for 2 x 20 min. The detection limit of this staining method was 1-4 pg for PhiX174 DNA/HaeIII in both nondenaturing and denaturing polyacrylamide gels. This staining method was especially effective in low-base pair DNA, with a sensitivity that was approximately ten-fold higher than previously published silver staining methods. PMID:16568502

  20. Fiber based optical tweezers for simultaneous in situ force exertion and measurements in a 3D polyacrylamide gel compartment

    PubMed Central

    Ti, Chaoyang; Thomas, Gawain M; Ren, Yundong; Zhang, Rui; Wen, Qi; Liu, Yuxiang

    2015-01-01

    Optical tweezers play an important role in biological applications. However, it is difficult for traditional optical tweezers based on objective lenses to work in a three-dimensional (3D) solid far away from the substrate. In this work, we develop a fiber based optical trapping system, namely inclined dual fiber optical tweezers, that can simultaneously apply and measure forces both in water and in a 3D polyacrylamide gel matrix. In addition, we demonstrate in situ, non-invasive characterization of local mechanical properties of polyacrylamide gel by measurements on an embedded bead. The fiber optical tweezers measurements agree well with those of atomic force microscopy (AFM). The inclined dual fiber optical tweezers provide a promising and versatile tool for cell mechanics study in 3D environments.

  1. A method for detection of cellulases in polyacrylamide gels using 5-bromoindoxyl-beta-D-cellobioside: high sensitivity and resolution.

    PubMed

    Chernoglazov, V M; Ermolova, O V; Vozny, Y V; Klyosov, A A

    1989-11-01

    The assay of endo-1,4-beta-glucanases (cellulases) from Trichoderma reesei, T. longibrachiatum, and Sporotrichum pulverulentum by 5-bromoindoxyl-beta-D-cellobioside is described. The substrate is enzymatically cleaved to afford 5-bromoindoxyl and latter undergoes immediate azo coupling with Fast Red or oxidation by nitroblue monotetrazolium chloride, various forms of endoglucanases which can thus be assayed in polyacrylamide gel. PMID:2610340

  2. Simple and Specific Dual-Wavelength Excitable Dye Staining for Glycoprotein Detection in Polyacrylamide Gels and Its Application in Glycoproteomics

    PubMed Central

    Chiang, Yu-Hsuan; Wu, Yu-Jen; Lu, Ya-Ting; Chen, Kuan-Hung; Lin, Tzu-Chun; Chen, Yu-Kuang H.; Li, Ding-Tzai; Shi, Fong-Ku; Chen, Ching-Chuan; Hsu, Jue-Liang

    2011-01-01

    In this study, a commercially available fluorescent dye, Lissamine rhodamine B sulfonyl hydrazine (LRSH), was designed to specifically stain the glycoproteins in polyacrylamide gels. Through the periodate/Schiff base mechanism, the fluorescent dye readily attaches to glycoproteins and the fluorescence can be simultaneously observed under either 305?nm or 532?nm excitation therefore, the dye-stained glycoproteins can be detected under a regular UV transilluminator or a more elegant laser-based gel scanner. The specificity and detection limit were examined using a standard protein mixture in polyacrylamide gels in this study. The application of this glycoprotein stain dye was further demonstrated using pregnancy urine samples. The fluorescent spots were further digested in gel and their identities confirmed through LC-MS/MS analysis and database searching. In addition, the N-glycosylation sites of LRSH-labeled uromodulin were readily mapped via in-gel PNGaseF deglycosylation and LC-MS/MS analysis, which indicated that this fluorescent dye labeling does not interfere with enzymatic deglycosylation. Hence, the application of this simple and specific dual-wavelength excitable dye staining in current glycoproteome research is promising. PMID:21976968

  3. Multifunctional graphene incorporated polyacrylamide conducting gel electrolytes for efficient quasi-solid-state quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Duan, Jialong; Tang, Qunwei; Li, Ru; He, Benlin; Yu, Liangmin; Yang, Peizhi

    2015-06-01

    Pursuit of a high efficiency and stability has been a persistent objective for quantum dot-sensitized solar cells (QDSCs). Here we launch a strategy of synthesizing graphene implanted polyacrylamide (PAAm-G) conducting gel electrolytes for quasi-solid-state QDSCs. With an aim of elevating the dosage of S2-/Sx2- redox couples and therefore charge-transfer ability, both osmotic press across the PAAm-G and capillary force within the three-dimensional micropores are utilized as driving forces. A promising power conversion efficiency of 2.34% is recorded for the QDSCs by optimizing graphene dosage in the conducting gel electrolyte. The enhanced conversion efficiency of solar cell is attributed to the expanded catalytic area from counter electrolyte/electrolyte interface to both interface and the conducting gel electrolyte.

  4. Improving sodium dodecyl sulfate polyacrylamide gel electrophoresis detection of low-abundance protein samples by rapid freeze centrifugation.

    PubMed

    Virgen-Ortíz, J J; Ibarra-Junquera, V; Escalante-Minakata, P; Osuna-Castro, J A; Ornelas-Paz, J de J; Mancilla-Margalli, N A; Castañeda-Aguilar, R L

    2013-12-15

    This work presents a rapid and simple freeze centrifugation method to concentrate dilute protein solutions for detection by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) Coomassie blue staining. Moreover, a simple way to assemble a cryoconcentration device is presented, and its use is discussed. Commercial purified protein standard and an enzyme with high fructosyltransferase (FTase) activity, coming from target fractions obtained by chromatographic separation, were used as an example. FTase, coming directly from the chromatographic fractions, was difficult to view through SDS-PAGE analysis; however, it was easily visualized, and its activity was enhanced, after the application of the freeze centrifugation protocol presented here. PMID:24050966

  5. Microfluidic two-dimensional separation of proteins combining temperature gradient focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

    PubMed

    Shameli, Seyed Mostafa; Ren, Carolyn L

    2015-04-01

    A two-dimensional separation system is presented combining scanning temperature gradient focusing (TGF) and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) in a PDMS/glass microfluidic chip. Denatured proteins are first focused and separated in a 15 mm long channel via TGF with a temperature range of 16-47 °C and a pressure scanning rate of -0.5 Pa/s and then further separated via SDS-PAGE in a 25 mm long channel. A side channel is designed at the intersection between the two dimensions to continuously inject SDS into the gel, allowing SDS molecules to be compiled within the focused bands. Separation experiments are performed using several fluorescently labeled proteins with single point detection. Experimental results show a dramatic improvement in peak capacity over one-dimensional separation techniques. PMID:25787346

  6. Mutation analysis of fragile X syndrome by Southern blot, radioactive PCR, silver-stained polyacrylamide gel and DIG DNA

    SciTech Connect

    Lee, Sook-Hwan; Kim, Un-Kyung; Chung-Woong, M.S. [CHA General Hospital, Seoul (Korea, Republic of)] [and others

    1994-09-01

    Fragile X syndrome is the most common inherited form of mental retardation. In fragile X syndrome, the underlying mutation is caused by an expansion of the CTG triplet in the 5{prime} untranslated region of the FMR-1 gene located at Xq27.3 and diagnosed by methylation of the associated CpG island. This disorder becomes clinically manifested when the mutation is caused by an expansion of (CGG)n reaching a threshold of about 600bp (200 repeats). The number of inserted repeats increases through the generation. We have analyzed fragile X syndrome by 4 different methods: Southern blot, radioactive PCR, polyacrylamide gel and DIG DNA labeling/detection techniques. Southern blot and DIG DNA labeling/detection by double DNA digestion with EcoRI and EagI reveals both the presence of the mutation and the methylation status. Radioactive PCR and silver-stained polyacrylamide gel is a rapid and sensitive technique to define the unaffected carriers and NTMs, but it is difficult to amplify such a highly GC-rich sequence. Further testing in other fragile X patients is currently in progress.

  7. Process for enhanced delayed in situ gelation of chromium polyacrylamide gels

    SciTech Connect

    Tackett, J.E. Jr.

    1991-12-03

    This patent describes a process for selectively plugging high permeability regions in a subterranean hydrocarbon-bearing formation penetrated by a well bore in fluid communication with the high permeability regions. It comprises: predetermining a gelation delay time required to place an aqueous gelation solution into the high permeability regions; preparing at the surface the aqueous gelation solution comprised of a polyacrylamide polymer containing less than about 0.1 mole% polymer carboxylate groups, a delaying agent, an aqueous solvent, a buffer, and a polyvalent metal carboxylate crosslinking agent capable of crosslinking polyacrylamide; injecting the aqueous gelation solution in the high permeability regions via the well bore; gelling the aqueous gelation solution in the high permeability region after the gelation delay time to reduce the permeability of the region.

  8. Fluorography--limitations on its use for the quantitative detection of /sup 3/H- and /sup 14/-C-labeled proteins in polyacrylamide gels

    SciTech Connect

    Harding, C.R.; Scott, I.R.

    1983-03-01

    The suitability of fluorography for the detection of /sup 3/H- and /sup 14/C-labeled proteins on polyacrylamide gradient gels has been investigated. If was found that the absorbance of the fluorographic film image produced by a given level of radioactivity decreased as the acrylamide concentration in the gel increased. The use of Coomassie brilliant blue protein dyes to stain the gel prior to fluorography reduced the absorbance of the fluorographic image. It is concluded that quantitative fluorography can only be applied to unstained gels of a uniform acrylamide concentration.

  9. Applications of SYPRO Orange and SYPRO Red Protein Gel Stains

    Microsoft Academic Search

    Thomas H. Steinberg; Richard P. Haugland; Victoria L. Singer

    1996-01-01

    We have further characterized the sensitivity and specificity of SYPRO Orange protein gel stain and SYPRO Red protein gel stain with native and 2-dimensional polyacrylamide gels and for staining gels prior to Western blot analysis. We found that nucleic acids are not stained by the SYPRO protein gel stains, in contrast to results obtained with commonly used silver staining techniques.

  10. Solution NMR of proteins within polyacrylamide gels: Diffusional properties and residual alignment by mechanical stress or embedding of oriented purple membranes

    Microsoft Academic Search

    Hans-Jürgen Sass; Giovanna Musco; Stephen J. Stahl; Paul T. Wingfield; Stephan Grzesiek

    2000-01-01

    The diffusive properties of biomacromolecules within the aqueous phase of polyacrylamide gels are described. High quality NMR spectra can be obtained under such conditions. As compared to water, a fivefold reduction in the translational diffusion constant, but only a 1.6-fold decrease (1.4-fold increase) in amide-15N T2 (T1) are observed for human ubiquitin within a 10% acrylamide gel. Weak alignment of

  11. A comparison of extracted proteins of isolates of Dermatophilus congolensis by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting

    Microsoft Academic Search

    A. A Makinde; C. L Gyles

    1999-01-01

    Antigenic diversity within a collection of 18 isolates of Dermatophilus congolensis from different Continents was examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and by Western blotting with sera from cattle with clinical dermatophilosis using whole cell extracts obtained by three methods and one extract of extracellular products of D. congolensis. One of the methods involving the release of a

  12. Characterization of Renal Damage in Canine Leptospirosis by Sodium Dodecyl Sulphate–Polyacrylamide Gel Electrophoresis (SDS–PAGE) and Western Blotting of the Urinary Proteins

    Microsoft Academic Search

    C. Zaragoza; R. Barrera; F. Centeno; J. A. Tapia; M. C. Mañé

    2003-01-01

    Canine leptospirosis is a zoonotic disease that can cause interstitial nephritis. As a consequence of the renal damage, proteinuria may occur. To determine the urine protein pattern in the disease we performed sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) on the urine from 10 dogs with leptospirosis and 20 healthy dogs. Western blotting analysis of the urine samples with antibodies against

  13. Definition of Mycobacterium tuberculosis Culture Filtrate Proteins by Two-Dimensional Polyacrylamide Gel Electrophoresis, N-Terminal Amino Acid Sequencing, and Electrospray Mass Spectrometry

    Microsoft Academic Search

    MICHAEL G. SONNENBERG; JOHN T. BELISLE

    1997-01-01

    A number of the culture filtrate proteins secreted by Mycobacterium tuberculosis are known to contribute to the immunology of tuberculosis and to possess enzymatic activities associated with pathogenicity. However, a complete analysis of the protein composition of this fraction has been lacking. By using two-dimensional polyacrylamide gel electrophoresis, detailed maps of the culture filtrate proteins of M. tuberculosis H37Rv were

  14. Transfer ribonucleic acid synthesis during sporulation and spore outgrowth in Bacillus subtilis studied by two-dimensional polyacrylamide gel electrophoresis.

    PubMed Central

    Henner, D J; Steinberg, W

    1979-01-01

    The synthesis of transfer ribonucleic acid (tRNA) was examined during spore formation and spore outgrowth in Bacillus subtilis by two-dimensional polyacrylamide gel electrophoresis of in vivo 32P-labeled RNA. The two-dimensional gel system separated the B. subtilis tRNA's into 32 well-resolved spots, with the relative abundances ranging from 0.9 to 17% of the total. There were several spots (five to six) resolved which were not quantitated due to their low abundance. All of the tRNA species resolved by this gel system were synthesized at every stage examined, including vegetative growth, different stages of sporulation, and different stages of outgrowth. Quantitation of the separated tRNA's showed that in general the tRNA species were present in approximately the same relative abundances at the different developmental periods. tRNA turnover and compartmentation occurring during sporulation were examined by labeling during vegetative growth followed by the addition of excess phosphate to block further 32P incorporation. The two-dimensional gels of these samples showed the same tRNA's seen during vegetative growth, and they were in approximately the same relative abundances, indicating minimal differences in the rates of turnover of individual tRNA's. Vegetatively labeled samples, chased with excess phosphate into mature spores, also showed all of the tRNA species seen during vegetative growth, but an additional five to six minor spots were also observed. These are hypothesized to arise from the loss of 3'-terminal residues from preexisting tRNA's. Images PMID:115846

  15. Prestaining of glycoproteins in sodium dodecyl sulfate polyacrylamide gels by dansylhydrazine.

    PubMed

    Wang, Yang; Zhou, Xuan; Yu, Qing; Duan, Yuanmeng; Huang, Binbin; Hong, Guoying; Zhou, Ayi; Jin, Litai

    2014-06-01

    A new fluorescent prestaining method for gel-separated glycoproteins in 1D and 2D SDS-PAGE was developed by using dansylhydrazine in this study. The prestained gels could be easily imaged after electrophoresis without any time-consuming steps needed for poststains. As low as 4-8 ng glycoproteins (transferrin, ?1-acid glycoprotein) could be selectively detected, which is comparable to that of Pro-Q Emerald 488, one of the most commonly used glycoprotein stain. In addition, a subsequent study of deglycosylation, glycoprotein affinity isolation, and LC-MS/MS analysis was performed to confirm the specificity of the newly developed method. PMID:24668852

  16. Detection of neuronal growth inhibitory factor (metallothionein-3) in polyacrylamide gels and by Western blot analysis

    Microsoft Academic Search

    Gabriele Meloni; Markus Knipp; Milan Vašák

    2005-01-01

    Neuronal growth inhibitory factor (GIF) is a small cysteine-rich metal binding protein downregulated in Alzheimer's disease. The protein belongs to the superfamily of metallothioneins (MTs) and was classified as MT-3. Although first identified as a brain specific protein, several reports now indicate a substantially broader expression pattern. However, currently available detection methods for MT-3 show low sensitivity in gel electrophoresis

  17. Polyacrylamide Gel Photopatterning enables Automated Protein Immunoblotting in a Two-dimensional Microdevice

    E-print Network

    Herr, Amy E.

    ). Streptavidin-acrylamide (SA) was purchased from Invitrogen (Carlsbad, CA). Premixed 10× Tris­glycine native dodecyl sulfate (SDS), Cetyl trimethylammonium bromide (CTAB), 30% acrylamide/bis- acrylamide (29 with a 6%T precursor solution (including streptavidin-acrylamide) to UV excitation (~13 mW/cm2 ) for 8 min

  18. Exogenous expression of human SGLT1 exhibits aggregations in sodium dodecyl sulfate polyacrylamide gel electrophoresis

    PubMed Central

    Huang, Wei-Chien; Hsu, Sheng-Chie; Huang, Shyh-Jer; Chen, Yun-Ju; Hsiao, Yu-Chun; Zhang, Weihua; Fidler, Isaiah J; Hung, Mien-Chie

    2013-01-01

    Sodium/glucose co-transporter 1 (SGLT1), which actively and energy-dependently uptakes glucose, plays critical roles in the development of various diseases including diabetes mellitus and cancer, and has been viewed as a promising therapeutic target for these diseases. Protein-protein interaction with EGFR has been shown to regulate the expression and activity of SGLT1. Exogenous expression of SGLT1 is one of the essential approaches to characterize its functions; however, exogenously expressed SGLT1 is not firmly detectable by Western blot at its calculated molecular weight, which creates a hurdle for further understanding the molecular events by which SGLT1 is regulated. In this study, we demonstrated that exogenous SGLT1 functions in glucose-uptake normally but is consistently detected near the interface between stacking gel and running gel rather than at the calculated molecular weight in Western blot analysis, suggesting that the overexpressed SGLT1 forms SDS-resistant aggregates, which cannot be denatured and effectively separated on SDS-PAGE. Co-expression of EGFR enhances both the glucose-uptake activity and protein level of the SGLT1. However, fusion with Flag or HA tag at its carboxy- but not its amino-terminus abolished the glucose-uptake activity of exogenous SGLT1 without affecting its protein level. Furthermore, the solubility of SGLT1 aggregates was not affected by other detergents but was partially improved by inhibition of o-link glycosylation. These findings suggested exogenous overexpression of SGLT1 can function normally but may not be consistently detectable at its formula weight due to its gel-shift behavior by forming the SDS-resistant aggregates. PMID:23724167

  19. Exogenous expression of human SGLT1 exhibits aggregations in sodium dodecyl sulfate polyacrylamide gel electrophoresis.

    PubMed

    Huang, Wei-Chien; Hsu, Sheng-Chie; Huang, Shyh-Jer; Chen, Yun-Ju; Hsiao, Yu-Chun; Zhang, Weihua; Fidler, Isaiah J; Hung, Mien-Chie

    2013-01-01

    Sodium/glucose co-transporter 1 (SGLT1), which actively and energy-dependently uptakes glucose, plays critical roles in the development of various diseases including diabetes mellitus and cancer, and has been viewed as a promising therapeutic target for these diseases. Protein-protein interaction with EGFR has been shown to regulate the expression and activity of SGLT1. Exogenous expression of SGLT1 is one of the essential approaches to characterize its functions; however, exogenously expressed SGLT1 is not firmly detectable by Western blot at its calculated molecular weight, which creates a hurdle for further understanding the molecular events by which SGLT1 is regulated. In this study, we demonstrated that exogenous SGLT1 functions in glucose-uptake normally but is consistently detected near the interface between stacking gel and running gel rather than at the calculated molecular weight in Western blot analysis, suggesting that the overexpressed SGLT1 forms SDS-resistant aggregates, which cannot be denatured and effectively separated on SDS-PAGE. Co-expression of EGFR enhances both the glucose-uptake activity and protein level of the SGLT1. However, fusion with Flag or HA tag at its carboxy- but not its amino-terminus abolished the glucose-uptake activity of exogenous SGLT1 without affecting its protein level. Furthermore, the solubility of SGLT1 aggregates was not affected by other detergents but was partially improved by inhibition of o-link glycosylation. These findings suggested exogenous overexpression of SGLT1 can function normally but may not be consistently detectable at its formula weight due to its gel-shift behavior by forming the SDS-resistant aggregates. PMID:23724167

  20. [Quantitative study of multimolecular forms of serum gamma glutamyl transferase by polyacrylamide gel electrophoresis].

    PubMed

    Staeffen, J; Ballan, P; Ferrer, J; Beylot, J; Series, C; Terme, R

    1975-10-01

    The quantitative distribution of the multimolecular forms of serum gamma-glutamyl-transferase is studied in 286 sera by acrylamide gel electrophoresis, incubation, coloration in situ, photography, slide reading and integration. In 43 normal sera, the fast fraction represents 66% of the total activity; the ratio of the mean fast fraction to the medium and slow fraction was 2. During pregnancy (53 cases), in cord blood (54 cases), in hepatic cytolysis or cholestasis (55 cases), and in secondary liver carcinoma (21 cases), this ratio is considerably lower, demonstrating the predominance of medium and slow fractions. A similar decrease in the ratio, with predominance of the medium and slow fractions was seen in 22 cases of advanced cancer without metastases in the liver. PMID:241044

  1. Fast and Sensitive Colloidal Coomassie G-250 Staining for Proteins in Polyacrylamide Gels

    PubMed Central

    Dyballa, Nadine; Metzger, Sabine

    2009-01-01

    Coomassie Brilliant Blue (CBB) is a dye commonly used for the visualization of proteins separated by SDS-PAGE, offering a simple staining procedure and high quantitation. Furthermore, it is completely compatible with mass spectrometric protein identification. But despite these advantages, CBB is regarded to be less sensitive than silver or fluorescence stainings and therefore rarely used for the detection of proteins in analytical gel-based proteomic approaches. Several improvements of the original Coomassie protocol1 have been made to increase the sensitivity of CBB. Two major modifications were introduced to enhance the detection of low-abundant proteins by converting the dye molecules into colloidal particles: In 1988, Neuhoff and colleagues applied 20% methanol and higher concentrations of ammonium sulfate into the CBB G-250 based staining solution2, and in 2004 Candiano et al. established Blue Silver using CBB G-250 with phosphoric acid in the presence of ammonium sulfate and methanol3. Nevertheless, all these modifications just allow a detection of approximately 10 ng protein. A widely fameless protocol for colloidal Coomassie staining was published by Kang et al. in 2002 where they modified Neuhoff's colloidal CBB staining protocol regarding the complexing substances. Instead of ammonium sulfate they used aluminum sulfate and methanol was replaced by the less toxic ethanol4. The novel aluminum-based staining in Kang's study showed superior sensitivity that detects as low as 1 ng/band (phosphorylase b) with little sensitivity variation depending on proteins. Here, we demonstrate application of Kang's protocol for fast and sensitive colloidal Coomassie staining of proteins in analytical purposes. We will illustrate the quick and easy protocol using two-dimensional gels routinely performed in our working group. PMID:19684561

  2. Fast and sensitive colloidal coomassie G-250 staining for proteins in polyacrylamide gels.

    PubMed

    Dyballa, Nadine; Metzger, Sabine

    2009-01-01

    Coomassie Brilliant Blue (CBB) is a dye commonly used for the visualization of proteins separated by SDS-PAGE, offering a simple staining procedure and high quantitation. Furthermore, it is completely compatible with mass spectrometric protein identification. But despite these advantages, CBB is regarded to be less sensitive than silver or fluorescence stainings and therefore rarely used for the detection of proteins in analytical gel-based proteomic approaches. Several improvements of the original Coomassie protocol(1) have been made to increase the sensitivity of CBB. Two major modifications were introduced to enhance the detection of low-abundant proteins by converting the dye molecules into colloidal particles: In 1988, Neuhoff and colleagues applied 20% methanol and higher concentrations of ammonium sulfate into the CBB G-250 based staining solution(2), and in 2004 Candiano et al. established Blue Silver using CBB G-250 with phosphoric acid in the presence of ammonium sulfate and methanol(3). Nevertheless, all these modifications just allow a detection of approximately 10 ng protein. A widely fameless protocol for colloidal Coomassie staining was published by Kang et al. in 2002 where they modified Neuhoff's colloidal CBB staining protocol regarding the complexing substances. Instead of ammonium sulfate they used aluminum sulfate and methanol was replaced by the less toxic ethanol(4). The novel aluminum-based staining in Kang's study showed superior sensitivity that detects as low as 1 ng/band (phosphorylase b) with little sensitivity variation depending on proteins. Here, we demonstrate application of Kang's protocol for fast and sensitive colloidal Coomassie staining of proteins in analytical purposes. We will illustrate the quick and easy protocol using two-dimensional gels routinely performed in our working group. PMID:19684561

  3. Isolation of potential serodiagnostic Fasciola hepatica antigens by electroelution from polyacrylamide gels.

    PubMed

    Santiago, N; Hillyer, G V

    1986-11-01

    In the present study a partially purified antigen preparation enriched in Fasciola-specific antigens (designated p3 and 4) was used in the enzyme-linked immunoelectrotransfer blot (EITB) to identify polypeptides which induce antibody formation in acute fascioliasis. The pattern of antigens recognized by the sera of infected rabbits, humans, and cows was also compared. Similar but not identical patterns of recognition were obtained for the different models tested; the main antigenic polypeptides recognized were in clusters within 27-38, 18-23, and 11-14 Kd molecular weight (Mr) ranges. An antigen of 31-33 Kd was one of the most prominently recognized by all of the acute infection sera tested. This antigen, as well as those in the 18-23 Kd range, appear to have good specificity, as they are not recognized by antibodies to S. mansoni or P. westermani adult worm extracts. To further characterize and evaluate these low Mr antigens, we have isolated polypeptides by electrophoresing p3 and 4 F. hepatica antigens in 10%-15% gradient gels, identifying the desired Mr range with prestained markers, cutting individual gel strips, and then isolating them by electroelution. Antigen fractions of 19-23 and 31-33 Kd were isolated in this manner, re-electrophoresed, transferred to nitrocellulose and found to be reactive with the sera from a rabbit with acute fascioliasis. At least one of these antigens, of 20 Kd Mr, has been obtained by this means with a high degree of purity. This, as well as other antigen fractions isolated, showed high absorbance values in ELISA when reacted with the serum from a rabbit with an 8-week-old F. hepatica infection.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3538921

  4. Analysis of the Subunit Structure of Protochlorophyllide Holochrome by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis 1

    PubMed Central

    Canaani, Ora D.; Sauer, Kenneth

    1977-01-01

    The subunit structures of protochlorophyllide holochrome (PCH) and chlorophyllide holochrome (CH) were studied by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. PCH from leaves of dark-grown (Phaseolus vulgaris var. red kidney) is a polymeric pigment-protein complex of approximately 600,000 daltons. It is composed of 12 to 14 polypeptides of 45,000 daltons, when examined prior to and immediately following photoconversion. The protochlorophyllide or chlorophyllide pigment molecules are associated with these polypeptides. Subsequent to photoconversion, the absorption maximum of newly formed chlorophyllide shifts from 678 nm to 674 nm upon standing in darkness. Following the 678 to 674 spectral shift, the chlorophyllide is associated with a polypeptide with a molecular weight of 16,000 daltons. In addition, sucrose gradient centrifugation of PCH and CH under nondenaturing conditions indicates that during the course of the dark spectroscopic shift, the 600,000 dalton CH undergoes dissociation into a small chlorophyllide protein. The dissociation of CH, the change in the molecular weight of the chlorophyllide polypeptide from 45,000 to 16,000 daltons, as well as the dark spectroscopic shift are temperature-dependent and blocked below 0 C. It was also found that each holochrome molecule of 600,000 daltons contains at least four protochlorophyllide pigment molecules. PMID:16660106

  5. Survey of rotavirus infection in a dairy herd: comparison between polyacrylamide gel electrophoresis and two commercial tests.

    PubMed

    García-Sánchez, J; Corral, C; Halaihel, N G; Simon, M C; Alonso, J L; Muzquiz, J L; Ortega, C; Girones, O

    1993-04-01

    A survey of rotavirus infection in a dairy herd with a history of neonatal diarrhoea was carried out. Faecal samples taken from 15 cows before and after calving as well as faeces taken from their calves daily from birth to two weeks of life were tested for rotavirus by polyacrylamide gel electrophoresis (PAGE) and compared with an ELISA and a latex agglutination commercial test. Rotavirus excretion was not detected in faeces from cows around parturition by any of the three tests. However, all of their calves shed rotaviruses during the observation period. The onset of rotavirus excretion determined by PAGE ranged from day 2 to day 8 of life (day 4.8 +/- 1.8 on average) and lasted for 4 to 7 days (5.3 +/- 1.1 days on average). Chi-square test showed a significant association (P = 0.0001) between the presence of rotavirus and the altered consistency of calves faeces. All the three tests showed similar results (overall agreement 92.5%) but discrepancies were detected mainly at the beginning or at the end of the rotavirus excretion period. Results obtained with both commercial kits closely paralleled each other and parameters other than sensitivity, specificity, diagnostic accuracy or predictive values have to be considered as selection criteria. PMID:8389499

  6. Proteins of the Inner Membrane of Escherichia coli: Identification of Succinate Dehydrogenase by Polyacrylamide Gel Electrophoresis with sdh Amber Mutants

    PubMed Central

    Spencer, Margaret E.; Guest, J. R.

    1974-01-01

    The inner or cytoplasmic membrane fraction of the cell envelope of Escherichia coli was isolated by isopycnic centrifugation on sucrose gradients. The membrane proteins were analyzed by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels (8.5%), and up to 56 bands were resolved. Different preparations gave very similar patterns of proteins. Succinate dehydrogenase mutants (sdh) were isolated which could not grow on succinate minimal medium, although growth on fumarate was unimpaired. The protein patterns of inner membrane preparations from sdh amber mutants were compared with the wild type, and one major band was greatly reduced in the mutants. This component, which represented approximately 5% of the inner membrane protein, was restored by introducing an amber suppressor gene (supU), which also restored the Sdh+ phenotype. The band corresponded to a protein with a molecular weight of 67,000 daltons, which is close to that for the large subunits of the succinate dehydrogenases of Rhodospirillum rubrum and beef heart mitochondria. Images PMID:4591960

  7. Protein\\/RNA coextraction and small two-dimensional polyacrylamide gel electrophoresis for proteomic\\/gene expression analysis of renal cancer biopsies

    Microsoft Academic Search

    Giovanna Barbero; Franco Carta; Giuliana Giribaldi; Giorgia Mandili; Salvatore Crobu; Carlo Ceruti; Dario Fontana; Paolo Destefanis; Francesco Turrini

    2006-01-01

    A small amount of bioptic tissue (?5–10mg of fresh tissue) usually does not contain enough material to extract protein and RNA separately, to obtain preparative two-dimensional polyacrylamide gel electrophoresis (2-DE), and to identify a large number of separated proteins by MS. We tested a method, on small renal cancer specimens, for the coextraction of protein and RNA coupled with 2-DE

  8. Studies on middle silkgland proteins of cocoon colour sex-limited silkworm ( Bombyx mori L.) using two-dimensional polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Yuan-Xiang Jin; Yu-Yin Chen; Meng-Kui Xu; Yong-Huang Jiang

    2004-01-01

    Qualitative and quantitative differences in proteins expressed in the middle silkglands of male and female silkworm larvae\\u000a that differ in silk colour were investigated by high resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE),\\u000a followed by computer assisted image analysis. About 1000 protein spots were resolved in both the sexes and most proteins were\\u000a shown to be distributed in the area

  9. Lithium Dodecyl Sulfate\\/Polyacrylamide Gel Electrophoresis of Thylakoid Membranes at 4 degrees C: Characterizations of Two Additional Chlorophyll A-Protein Complexes

    Microsoft Academic Search

    Philippe Delepelaire; Nam-Hai Chua

    1979-01-01

    Lithium dodecyl sulfate\\/polyacrylamide gel electrophoresis of Chlamydomonas reinhardtii thylakoid membranes at room temperature gave two chlorophyll-protein complexes, CP I and CP II, as had been reported previously. However, when the electrophoresis was performed at 4 degrees C, there was an increase in the amount of chlorophyll associated with CP I and CP II, and in addition, three other chlorophyll-protein complexes

  10. Resolution of Fusarium sporotrichioides proteins by two-dimensional polyacrylamide gel electrophoresis and identification by sequence homology comparison in protein data base

    Microsoft Academic Search

    Lu-Ping Chow; Nobuhito Fukaya; Norifumi Miyatake; Katsuhisa Horimoto; Yoshitsugu Sugiura; Kiyoshi Tabuchi; Yoshio Ueno; Akira Tsugita

    1995-01-01

    Proteins fromFusarium sporotrichioides M-1-1, a T2-toxin-producing strain, were separated by two-dimensional polyacrylamide gel electrophoresis. One thousand two hundred and forty-four protein spots were resolved and 103 protein spots were subjected to N-terminal sequencing. Fifty-eight protein spots were sequenced and 48 proteins were observed to have blocked N termini. Forty out of 58 sequenced proteins were identified by homology search against

  11. Analysis of the Gc polymorphism in human populations by isoelectrofocusing on polyacrylamide gels. Demonstration of subtypes of the Gc 1 allele and of additional Gc variants

    Microsoft Academic Search

    J. Constansl; M. Viau; H. Cleve; G. Jaeger; J. C. Quilici; M. J. Palisson

    1978-01-01

    For the study of the group-specific component (Gc) system, serum samples were examined by polyacrylamide gel electrophoresis and by a newly developed immunofixation isoelectrofocusing procedure. Thereby, a greater extent of polymorphic variation was revealed than was known previously. The allele Gc1 could be subdivided into the alleles Gc1F and Gc1S. The distribution of Gc1 subtypes was very different in three

  12. Stoichiometry of the MexA-OprM binding, as investigated by blue native gel electrophoresis.

    PubMed

    Ferrandez, Yann; Monlezun, Laura; Phan, Gilles; Benabdelhak, Houssain; Benas, Philippe; Ulryck, Nathalie; Falson, Pierre; Ducruix, Arnaud; Picard, Martin; Broutin, Isabelle

    2012-04-01

    Multidrug resistance has become a serious concern in the treatment of bacterial infections. A prominent role is ascribed to the active efflux of xenobiotics out of the bacteria by a tripartite protein machinery. The mechanism of drug extrusion is rather well understood, thanks to the X-ray structures obtained for the Escherichia coli TolC/AcrA/AcrB model system and the related Pseudomonas aeruginosa OprM/MexA/MexB. However, many questions remain unresolved, in particular the stoichiometry of the efflux pump assembly. On the basis of blue native polyacrylamide gel electrophoresis (BN-PAGE) (Wittig et al., Nat. Protoc. 2006, 1, 418-428), we analyzed the binding stoichiometry of both palmitylated and non-palmitylated MexA with the cognate partner OprM trimer at different ratios and detergent conditions. We found that ?-octyl glucopyranoside (?-OG) detergent was not suitable for this technique. Then we proved that MexA has to be palmitylated in order to stabilized the complex formation with OprM. Finally, we provided evidence for a two by two (2, 4, 6, or upper) binding of palmitylated MexA per trimer of OprM. PMID:22589107

  13. Blue native polyacrylamide gel electrophoresis and the monitoring of malate-and

    E-print Network

    Appanna, Vasu

    of the tricarboxylic acid (TCA) cycle and is involved in the reversible hydration of fumarate to malate. The malate of energy, in gluconeogensis, in lipogenesis, and in the metabolism of amino acids. PC [E.C. 6-CoA from acetyl-CoA, ATP and HCO3 À is a critical step in the formation of fatty acid in most organisms [3

  14. Analysis of mitochondrial subunit assembly into respiratory chain complexes using Blue Native polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Matthew McKenzie; Michael Lazarou; David R. Thorburn; Michael T. Ryan

    2007-01-01

    The mitochondrial respiratory chain consists of multi-subunit protein complexes embedded in the inner membrane. Although the majority of subunits are encoded by nuclear genes and are imported into mitochondria, 13 subunits in humans are encoded by mitochondrial DNA. The coordinated assembly of subunits encoded from two genomes is a poorly understood process, with assembly pathway defects being a major determinant

  15. SU-E-T-105: Development of 3D Dose Verification System for Volumetric Modulated Arc Therapy Using Improved Polyacrylamide-Based Gel Dosimeter

    SciTech Connect

    Ono, K; Fujimoto, S; Akagi, Y; Hirokawa, Y [Hiroshima Heiwa Clinic, Hiroshima (Japan); Hayashi, S [Hiroshima International University, Hiroshima (Japan); Miyazawa, M [R-TECH.INC, Toukyo (Japan)

    2014-06-01

    Purpose: The aim of this dosimetric study was to develop 3D dose verification system for volumetric modulated arc therapy (VMAT) using polyacrylamide-based gel (PAGAT) dosimeter improved the sensitivity by magnesium chloride (MgCl{sub 2}). Methods: PAGAT gel containing MgCl{sub 2} as a sensitizer was prepared in this study. Methacrylic-acid-based gel (MAGAT) was also prepared to compare the dosimetric characteristics with PAGAT gel. The cylindrical glass vials (4 cm diameter, 12 cm length) filled with each polymer gel were irradiated with 6 MV photon beam using Novalis Tx linear accelerator (Varian/BrainLAB). The irradiated polymer gel dosimeters were scanned with Signa 1.5 T MRI system (GE), and dose calibration curves were obtained using T{sub 2} relaxation rate (R{sub 2} = 1/T{sub 2}). Dose rate (100-600 MU min{sup ?1}) and fractionation (1-8 fractions) were varied. In addition, a cubic acrylic phantom (10 × 10 × 10 cm{sup 3}) filled with improved PAGAT gel inserted into the IMRT phantom (IBA) was irradiated with VMAT (RapidArc). C-shape structure was used for the VMAT planning by the Varian Eclipse treatment planning system (TPS). The dose comparison of TPS and measurements with the polymer gel dosimeter was accomplished by the gamma index analysis, overlaying the dose profiles for a set of data on selected planes using in-house developed software. Results: Dose rate and fractionation dependence of improved PAGAT gel were smaller than MAGAT gel. A high similarity was found by overlaying the dose profiles measured with improved PAGAT gel dosimeter and the TPS dose, and the mean pass rate of the gamma index analysis using 3%/3 mm criteria was achieved 90% on orthogonal planes for VMAT using improved PAGAT gel dosimeter. Conclusion: In-house developed 3D dose verification system using improved polyacrylamide-based gel dosimeter had a potential as an effective tool for VMAT QA.

  16. Ultrasensitive Detection of Unstained Proteins in Acrylamide Gels by Native UV Fluorescence

    E-print Network

    Bielefeld, Universität

    Ultrasensitive Detection of Unstained Proteins in Acrylamide Gels by Native UV Fluorescence Jan, Germany Visualization of proteins inside acrylamide and other gels usually relies on different staining methods. To omit the protein-staining procedure, we visualized unstained pro- teins inside acrylamide gels

  17. Simultaneous concentration enrichment and electrophoretic separation of weak acids on a microchip, using in situ photopolymerized carboxylate-type polyacrylamide gels as the permselective preconcentrator.

    PubMed

    Yamamoto, Sachio; Watanabe, Yuki; Nishida, Noriaki; Suzuki, Shigeo

    2011-10-01

    A method for the simultaneous concentration and separation of weak acids using an acidic polyacrylamide gel, fabricated in the microfluidic channel of a commercial poly(methyl methacrylate)-made microchip, is reported. This approach is based on simple photochemical copolymerization for the fabrication of a permselective preconcentrator. The intersection of the poly(methyl methacrylate)-made microchip was filled with a gel solution comprising acrylamide, N,N'-methylene-bis-acrylamide, and 2-acrylamidoglycolic acid, with riboflavin as a photocatalytic initiator. In situ polymerization, near the cross of the sample outlet channel, was performed by irradiation with an argon ion laser beam that is also used as the light source for fluorimetric detection. The electrokinetic properties, combined with electrostatic repulsion between sample components and the anionic groups on the polyacrylamide gel, enable the entrapment and concentration of weak acids at the interface of the cathodic side of the gel plug. This method displays concentration factors of up to 10(5) within 3 min. The effectiveness of the ionic preconcentrator was demonstrated by the sensitive analysis of fluorescein isothiocyanate-labeled amino acids. PMID:21796791

  18. PhosphorImager enhancement of sedimentation equilibrium-quantitative polyacrylamide gel electrophoresis: a highly sensitive technique for quantitation of equilibrium gradients of individual components in mixtures.

    PubMed

    Darawshe, S; Merezhinskaya, N; Minton, A P

    1995-07-20

    The technique called sedimentation equilibrium-quantitative polyacrylamide gel electrophoresis (Darawshe et al. (1993) Anal. Biochem. 215, 236-242) has been extended to permit the quantitation and analysis of gradients of individual radiolabeled components in a mixture of radiolabeled solutes centrifuged to sedimentation equilibrium. Immediately following centrifugation, the contents of a sample tube are fractionated into aliquots corresponding to laminae of solution at different radial positions in the centrifuge. Following treatment with sodium dodecyl sulfate-containing buffer, a portion of each fraction is subjected to electrophoresis on a polyacrylamide gel. The gel is then incubated with a strong phosphor plate and subsequently scanned with a Molecular Dynamics PhosphorImage. The concentration of an individual radiolabeled component at a particular radial distance is proportional to the integrated intensity of the image of the radiolabeled band of that component in the fraction corresponding to that radial distance. Concentration gradients reconstructed in this fashion are interpreted in the context of conventional sedimentation equilibrium theory. The results of control experiments carried out with purified proteins of known molar mass and the measurement of the molar mass of a new, partially purified protein are reported. PMID:8533898

  19. Sequence dependence of benzo[a]pyrene diol epoxide-DNA adduct conformer distribution: A study by laser-induced fluorescence\\/polyacrylamide gel electrophoresis

    Microsoft Academic Search

    G. A. Marsch; R. Jankowiak; M. Suh; G. J. Small

    2009-01-01

    Low-temperature laser-induced fluorescence techniques in combination with polyacrylamide gel electrophoresis (LIF\\/PAGE) were used to study the binding of ([minus])-anti- and (+)-anti-benzo[a]pyrene 7,8-dihydrodiol 9,10-epoxide (anti-BPDE) to several sequence-defined duplex oligomers. Two of the oligomers contain central 5'-RAGGAR-3' sequences (R = purine) which appear to be frequently mutated by racemic ([+-])-anti-BPDE in endogenous genes of cells cultured in vitro. Two contain a

  20. The supramolecular structure of the GPCR rhodopsin in solution and native disc membranes

    E-print Network

    Palczewski, Krzysztof

    Suda$, Slawomir Filipek%, Krzysztof Palczewski#§', Andreas Engel$ and Dimitrios Fotiadis$* $ M.E. Mu microscopy/microscope; BN-PAGE, blue native-polyacrylamide gel electrophoresis; CCB, Coomassie brilliant blue

  1. A comparative study of the 'rhodochrous' complex and related taxa by delayed-type skin reactions on guinea pigs and by polyacrylamide gel electrophoresis.

    PubMed

    Hyman, I S; Chaparas, S D

    1977-06-01

    Cell extracts prepared by ultrasonic disruption of 17 strains of the 'rhodochrous' complex and related taxa were compared by polyacrylamide gel electrophoresis and for immunologic relatedness, by skin test reactions. Two organisms, Jensenia canicruria and Nocardia calcarea, gave similar gel patterns and skin test reactions, and are considered to be identical. Extracts of nocardia rubra showed a strong antigenic relationship with those of three Nocardia pellegrino organisms (N325, N324 and N420) previously assigned to the 'rhodochrous' complex. Two Gordona organisms appeared to be less antigenically related to the 'rhodochrous' complex. Extracts of three of four organisms designated Lspi (Rhodococcus coprophilus Rowbotham & Cross 1976) elicited skin test reactions similar to those of the 'rhodochrous' strains. One Lspi strain, N650, showed striking similarities to the 'rhodochrous' complex strain N420 (Nocardia pellegrino). PMID:70505

  2. Coupling sodium dodecyl sulfate-capillary polyacrylamide gel electrophoresis with matrix-assisted laser desorption ionization time-of-flight mass spectrometry via a poly(tetrafluoroethylene) membrane.

    PubMed

    Lu, Joann J; Zhu, Zaifang; Wang, Wei; Liu, Shaorong

    2011-03-01

    Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) is a fundamental analytical technique for proteomic research, and SDS-capillary gel electrophoresis (CGE) is its miniaturized version. Compared to conventional slab-gel electrophoresis, SDS-CGE has many advantages such as increased separation efficiency, reduced separation time, and automated operation. SDS-CGE is not widely accepted in proteomic research primarily due to the difficulties in identifying the well-resolved proteins. MALDI-TOF-MS is an outstanding platform for protein identifications. Coupling the two would solve the problem but is extremely challenging because the MS detector has no access to the SDS-CGE-resolved proteins and the SDS interferes with MS detection. In this work we introduce an approach to address these issues. We discover that poly(tetrafluoroethylene) (PTFE) membranes are excellent materials for collecting SDS-CGE-separated proteins. We demonstrate that we can wash off the SDS bound to the collected proteins and identify these proteins on-membrane with MALDI-TOF-MS. We also show that we can immunoblot and Coomassie-stain the proteins collected on these membranes. PMID:21309548

  3. Detection of metals in proteins by means of polyacrylamide gel electrophoresis and laser ablation-inductively coupled plasma-mass spectrometry: application to selenium.

    PubMed

    Chéry, Cyrille C; Günther, Detlef; Cornelis, Rita; Vanhaecke, Frank; Moens, Luc

    2003-10-01

    The capabilities of laser ablation-inductively coupled plasma-mass spectrometry for the detection of trace elements in a gel after gel electrophoresis were systematically studied. Figures of merit, such as limit of detection, linearity, and repeatability, were evaluated for various elements (Li, V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Pd, Ag, Cd, Pt, Tl, Pb). Two ablation strategies were followed: single hole drilling, relevant for ablation of spots after two-dimensional (2-D) separations, and ablation with translation, i.e., on a line, relevant for one-dimensional (1-D) separations. This technique was applied to the detection of selenoproteins in red blood cells extracts after a 1-D separation (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and the detection of selenium-containing proteins in yeast after 2-D electrophoresis (2-DE). The detection procedure was further improved by using the dynamic reaction cell technology, which allowed the removal of the Ar_2(+) interference and hence the use of the most abundant Se isotope, (80)Se. Reaction gases were compared (methane, carbon monoxide, ammonia, oxygen and the combination of argon (collision gas) and hydrogen (reaction gas)). In each instance, the reaction cell parameters were optimized in order to obtain the lowest detection limit for Se (as (80)Se(+), (82)Se(+) or (77)Se(+); and as (80)Se(16)O(+), (82)Se(16)O(+) or (77)Se(16)O(+) with O(2) as the reaction gas). Carbon monoxide was found to offer the best performance. The detection limit with the use of DRC and He as transport gas was 0.07 microg Se g(-1) gel with single hole drilling and 0.15 microg Se g(-1) gel for ablation with translation. PMID:14595676

  4. Sliding window dual gradient echo (SW-dGRE): T1 and proton resonance frequency (PRF) calibration for temperature imaging in polyacrylamide gel

    NASA Astrophysics Data System (ADS)

    Ong, J. T.; d'Arcy, J. A.; Collins, D. J.; Rivens, I. H.; ter Haar, G. R.; Leach, M. O.

    2003-07-01

    The aim of the work is to evaluate a magnetic resonance imaging (MRI) thermometry sequence suitable for targeting of focused ultrasound (FUS) when used in vascular occlusion studies. A sliding window dual gradient echo (SW-dGRE) sequence was used. This sequence has the capability of monitoring both T1 relaxation and phase changes, which vary with temperature. Preliminary work involved quantification of the changes in T1 relaxation time with temperature and obtaining the PRF shift coefficient in polyacrylamide gel as it underwent an exothermic reaction during polymerization (avoiding the use of an external heat source). Temperature changes were visualized using thermal maps acquired with the sequence. For FUS guidance a thermal imaging technique is required with a temporal resolution <5 s, a spatial resolution of ~1 mm and a temperature resolution of ~5 °C. The sequence was optimized to improve the CNR (contrast to noise ratio) and SNR (signal to noise ratio) in the phase and magnitude images respectively. The PRF coefficient obtained for the polyacrylamide gel was -9.98 +/- 0.24 ppb °C-1, whilst DeltaT1 and temperature change were related by a proportionality factor, the T1 temperature coefficient, of 102.3 +/- 2.9 ms °C-1. The sequence produces an image at every 1.4 s interval. In both magnitude and phase data, the in-plane resolution is +/-1.2 mm and the temperature resolution is ~2 °C. The advantage of this sequence is that the temperature obtained from the magnitude data can be confirmed independently using the phase data and vice versa. Thus the sequence can essentially be crosschecked.

  5. Hydrolyzed Polyacrylamide- Polyethylenimine- Dextran Sulfate Polymer Gel System as a Water Shut-Off Agent in Unconventional Gas Reservoirs 

    E-print Network

    Jayakumar, Swathika 1986-

    2012-07-09

    ) at low polymer concentrations with a delayed organic crosslinker. This crosslinker is more environmentally benign and provides much longer gelation time and stronger final gels than comparable polymer loadings with chromium carboxylate crosslinkers...

  6. System and method of infrared matrix-assisted laser desorption/ionization mass spectrometry in polyacrylamide gels

    DOEpatents

    Haglund, Jr., Richard F.; Ermer, David R.; Baltz-Knorr, Michelle Lee

    2004-11-30

    A system and method for desorption and ionization of analytes in an ablation medium. In one embodiment, the method includes the steps of preparing a sample having analytes in a medium including at least one component, freezing the sample at a sufficiently low temperature so that at least part of the sample has a phase transition, and irradiating the frozen sample with short-pulse radiation to cause medium ablation and desorption and ionization of the analytes. The method further includes the steps of selecting a resonant vibrational mode of at least one component of the medium and selecting an energy source tuned to emit radiation substantially at the wavelength of the selected resonant vibrational mode. The medium is an electrophoresis medium having polyacrylamide. In one embodiment, the energy source is a laser, where the laser can be a free electron laser tunable to generate short-pulse radiation. Alternatively, the laser can be a solid state laser tunable to generate short-pulse radiation. The laser can emit light at various ranges of wavelength.

  7. Pre-labeling of diverse protein samples with a fixed amount of Cy5 for sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis.

    PubMed

    Bjerneld, Erik J; Johansson, Johan D; Laurin, Ylva; Hagner-McWhirter, Åsa; Rönn, Ola; Karlsson, Robert

    2015-09-01

    A pre-labeling protocol based on Cy5 N-hydroxysuccinimide (NHS) ester labeling of proteins has been developed for one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. We show that a fixed amount of sulfonated Cy5 can be used in the labeling reaction to label proteins over a broad concentration range-more than three orders of magnitude. The optimal amount of Cy5 was found to be 50 to 250pmol in 20?l using a Tris-HCl labeling buffer at pH 8.7. Labeling protein samples with a fixed amount of dye in this range balances the requirements of sub-nanogram detection sensitivity and low dye-to-protein (D/P) ratios for SDS-PAGE. Simulations of the labeling reaction reproduced experimental observations of both labeling kinetics and D/P ratios. Two-dimensional electrophoresis was used to examine the labeling of proteins in a cell lysate using both sulfonated and non-sulfonated Cy5. For both types of Cy5, we observed efficient labeling across a broad range of molecular weights and isoelectric points. PMID:25957128

  8. A robust new strategy for high-molecular-weight proteome research: a 2-hydroxyethyl agarose/polyacrylamide gel enhanced separation and ZnO-PMMA nanobeads assisted identification.

    PubMed

    Shen, Wenwen; Shen, Chengpin; Xiong, Huanming; Lu, Haojie; Yang, Pengyuan

    2010-09-15

    A new mass spectrometry based analysis strategy has been established here for high-molecular-weight (HMW) proteome research. First, a 2-hydroxyethyl agarose/polyacrylamide (HEAG/PAM) electrophoresis gel was designed for the first time to realize an easy-handling separation method with high spatial resolution for HMW proteins, good reproducibility and mass spectrometry-compatible silver staining. Second, ZnO-polymethyl methacrylate (ZnO-PMMA) nanobeads were applied here for enriching and desalting the peptides from the HMW proteins. Third, the peptides were analyzed by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) with the presence of the ZnO-PMMA nanobeads, and their MS signals were enhanced markedly. The success rate of identification for HMW proteins was significantly increased due to high enriching efficiency and salt tolerance capability as well as signal enhancing capability of the ZnO-PMMA nanobeads. We believe that this analysis strategy will inspire and accelerate the HMW proteome studies. PMID:20801378

  9. A rapid method of species identification of wild chironomids (Diptera: Chironomidae) via electrophoresis of hemoglobin proteins in sodium dodecyl sulfate polyacrylamide gel (SDS-PAGE).

    PubMed

    Oh, J T; Epler, J H; Bentivegna, C S

    2014-10-01

    Studying aquatic benthic macroinvertebrates (BMIs) in the field requires accurate taxonomic identification, which can be difficult and time consuming. Conventionally, head capsule morphology has been used to identify wild larvae of Chironomidae. However, due to the number of species and possible damage and/or deformity of their head capsules, another supporting approach for identification is needed. Here, we provide hemoglobin (Hb) protein in hemolymph of chironomids as a new biomarker that may help resolve some of the ambiguities and difficulties encountered during taxonomic identification. Chironomids collected from two locations in Maine and New Jersey, USA were identified to the genus level and in some cases to the species-level using head capsule and body morphologies. The head capsule for a particular individual was then associated with a corresponding Hb protein profile generated from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Distinct Hb profiles were observed from one group (Thienemannimyia) and four genera (Chironomus, Cricotopus, Dicrotendipes, and Glyptotendipes) of chironomids. Several species were polymorphic, having more than one Hb profile and/or having bands of the same size as those of other species. However, major bands and the combination of bands could distinguish individuals at the genus and sometimes species-level. Overall, this study showed that Hb profiles can be used in combination with head capsule morphology to identify wild chironomids. PMID:24923437

  10. Variation and Genomic Localization of Genes Encoding DROSOPHILA MELANOGASTER Male Accessory Gland Proteins Separated by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

    PubMed Central

    Whalen, Michael; Wilson, Thomas G.

    1986-01-01

    Accessory gland proteins from Drosophila melanogaster males have been separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis into nine major bands. When individual males from 175 strains were examined, considerable polymorphism for nearly one-half of the major protein bands was seen, including null alleles for three bands. Variation was observed not only among long-established laboratory strains but also among stocks recently derived from natural populations. There was little difference in the amount of variation between P and M strains, indicating that P element mutagenesis is not a factor producing the variation. Codominant expression of variants for each of five bands was found in heterozygotes, suggesting structural gene variation and not posttranslational modification variation. Stocks carrying electrophoretic variants of four of the major proteins were used to map the presumed structural genes for these proteins; the loci were found to be dispersed on the second chromosome. Since males homozygous for variant proteins were fertile, the polymorphism seems to have little immediate effect on successful sperm transfer. We propose that a high degree of polymorphism can be tolerated because these proteins play a nutritive rather than enzymatic role in Drosophila reproduction. PMID:3095182

  11. Proteinases secreted by Fasciola hepatica: time course of the inhibitory effect of serum from experimentally infected rabbits demonstrated by gelatin-substrate polyacrylamide gel electrophoresis.

    PubMed

    Piacenza, L; Acosta, D; Dowd, A; McGonicle, S; Dalton, J; Carmona, C

    1997-12-01

    Fasciola hepatica secretes proteolytic enzymes to aid it to penetrate and migrate through the host tissues. Two of these proteinases have been purified and shown to be cathepsin L-like, and are termed, CL1 (27.5 kD) and CL2 (29 kD). The immunogenicity of these proteinases was investigated over the course of an experimental infection and following drug treatment. Four groups of rabbits were studied: group 1: orally infected with 50 metacercariae; group 2: infected and treated 8 weeks after infection; group 3: infected, treated at week 8 and reinfected at week 13 and group 4: non-infected control group. Sera were collected weekly from each group until week 20 postinfection. CL1 and CL2 were incubated with the different sera and then analysed by gelatin substrate polyacrylamide gel electrophoresis (GS-PAGE). Analysis of groups 1, 2 and 3 showed that CL1 and CL2 neutralizing antibodies appear at week 5 post-infection. In group 1, these remained throughout the 20 weeks of infection. In group 2, neutralizing antibodies disappeared at week 13, that is, 5 weeks after anti-Fasciola treatment. In group 3, CL1 and CL2 neutralizing antibodies disappeared at week 13 but reappeared by week 15, that is 2 weeks after reinfection. Pooled sera from group 4, showed no inhibitory capacity. ELISA results using CL1 and CL2 as antigen, correlate very well with the inhibitiory time course observed by GS-PAGE. These results suggest that purified cathepsin Ls are antigenic molecules recognized early in the infective process and capable of inducing a specific humoral response, strong enough to neutralize, at least partially, their enzymatic activity. PMID:9443952

  12. Native gel electrophoresis of human telomerase distinguishes active complexes with or without dyskerin

    PubMed Central

    Gardano, Laura; Holland, Linda; Oulton, Rena; Le Bihan, Thierry; Harrington, Lea

    2012-01-01

    Telomeres, the ends of linear chromosomes, safeguard against genome instability. The enzyme responsible for extension of the telomere 3? terminus is the ribonucleoprotein telomerase. Whereas telomerase activity can be reconstituted in vitro with only the telomerase RNA (hTR) and telomerase reverse transcriptase (TERT), additional components are required in vivo for enzyme assembly, stability and telomere extension activity. One such associated protein, dyskerin, promotes hTR stability in vivo and is the only component to co-purify with active, endogenous human telomerase. We used oligonucleotide-based affinity purification of hTR followed by native gel electrophoresis and in-gel telomerase activity detection to query the composition of telomerase at different purification stringencies. At low salt concentrations (0.1?M NaCl), affinity-purified telomerase was ‘supershifted’ with an anti-dyskerin antibody, however the association with dyskerin was lost after purification at 0.6?M NaCl, despite the retention of telomerase activity and a comparable yield of hTR. The interaction of purified hTR and dyskerin in vitro displayed a similar salt-sensitive interaction. These results demonstrate that endogenous human telomerase, once assembled and active, does not require dyskerin for catalytic activity. Native gel electrophoresis may prove useful in the characterization of telomerase complexes under various physiological conditions. PMID:22187156

  13. Definition of Mycobacterium tuberculosis culture filtrate proteins by two-dimensional polyacrylamide gel electrophoresis, N-terminal amino acid sequencing, and electrospray mass spectrometry.

    PubMed Central

    Sonnenberg, M G; Belisle, J T

    1997-01-01

    A number of the culture filtrate proteins secreted by Mycobacterium tuberculosis are known to contribute to the immunology of tuberculosis and to possess enzymatic activities associated with pathogenicity. However, a complete analysis of the protein composition of this fraction has been lacking. By using two-dimensional polyacrylamide gel electrophoresis, detailed maps of the culture filtrate proteins of M. tuberculosis H37Rv were generated. In total, 205 protein spots were observed. The coupling of this electrophoretic technique with Western blot analysis allowed the identification and mapping of 32 proteins. Further molecular characterization of abundant proteins within this fraction was achieved by N-terminal amino acid sequencing and liquid chromatography-mass spectrometry. Eighteen proteins were subjected to N-group analysis; of these, only 10 could be sequenced by Edman degradation. Among the most interesting were a novel 52-kDa protein demonstrating significant homology to an alpha-hydroxysteroid dehydrogenase of Eubacterium sp. strain VPI 12708, a 25-kDa protein corresponding to open reading frame 28 of the M. tuberculosis cosmid MTCY1A11, and a 31-kDa protein exhibiting an amino acid sequence identical to that of antigen 85A and 85B. This latter product migrated with an isoelectric point between those of antigen 85A and 85C but did not react with the antibody specific for this complex, suggesting that there is a fourth member of the antigen 85 complex. Novel N-terminal amino acid sequences were obtained for three additional culture filtrate proteins; however, these did not yield significant homology to known protein sequences. A protein cluster of 85 to 88 kDa, recognized by the monoclonal antibodies IT-57 and IT-42 and known to react with sera from a large proportion of tuberculosis patients, was refractory to N-group analysis. Nevertheless, mass spectrometry of peptides obtained from one member of this complex identified it as the M. tuberculosis KatG catalase/peroxidase. Thus, the detailed mapping of M. tuberculosis proteins, combined with state-of-the-art analytical techniques such as mass spectrometry, provides a basis for further analysis and rapid identification of biologically relevant molecules. PMID:9353028

  14. Phase transition in swollen gels 31. Swelling and mechanical behaviour of interpenetrating networks composed of poly(1-vinyl-2-pyrrolidone) and polyacrylamide in water\\/acetone mixtures

    Microsoft Academic Search

    Michal Ilavský; Galym Mamytbekov; Lenka Hanyková; Karel Dušek

    2002-01-01

    Swelling and mechanical behaviour of interpenetrating positively charged polymer networks (IPNs), composed of poly(1-vinyl-2-pyrrolidone) (PVP) networks and polyacrylamide (PAAm) networks, was investigated in water\\/acetone mixtures. The first PVP networks were prepared by radiation polymerization at room temperature; after that the PVP networks were swollen in PAAm aqueous solutions and the networks were prepared by thermal copolymerization at 65 °C. The

  15. Gene expression in the pulp of ripening bananas. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of in vitro translation products and cDNA cloning of 25 different ripening-related mRNAs.

    PubMed Central

    Medina-Suárez, R; Manning, K; Fletcher, J; Aked, J; Bird, C R; Seymour, G B

    1997-01-01

    mRNA was extracted from the pulp and peel of preclimacteric (d 0) bananas (Musa AAA group, cv Grand Nain) and those exposed to ethylene gas for 24 h and stored in air alone for a further 1 (d 2) and 4 d (d 5). Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of in vitro translation products from the pulp and peel of these fruits revealed significant up-regulation of numerous transcripts during ripening. The majority of the changes were initiated by d 2, with the level of these messages increasing during the remainder of the ripening period. Pulp tissue from d 2 was used for the construction of a cDNA library. This library was differentially screened for ripening-related clones using cDNA from d-0 and d-2 pulp by a novel microtiter plate method. In the primary screen 250 up- and down-regulated clones were isolated. Of these, 59 differentially expressed clones were obtained from the secondary screen. All of these cDNAs were partially sequenced and grouped into families after database searches. Twenty-five nonredundant groups of pulp clones were identified. These encoded enzymes were involved in ethylene biosynthesis, respiration, starch metabolism, cell wall degradation, and several other key metabolic events. We describe the analysis of these clones and their possible involvement in ripening. PMID:9342865

  16. Absence of a Putative Mannose-Specific Phosphotransferase System Enzyme IIAB Component in a Leucocin A-Resistant Strain of Listeria monocytogenes, as Shown by Two-Dimensional Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

    PubMed Central

    Ramnath, M.; Beukes, M.; Tamura, K.; Hastings, J. W.

    2000-01-01

    Leucocin A is a class IIa bacteriocin produced by Leuconostoc spp. that has previously been shown to inhibit the growth of Listeria monocytogenes. A spontaneous resistant mutant of L. monocytogenes was isolated and found to be resistant to leucocin A at levels in excess of 2 mg/ml. The mutant showed no significant cross-resistance to nontype IIa bacteriocins including nisaplin and ESF1-7GR. However, there were no inhibition zones found on a lawn of the mutant when challenged with an extract containing 51,200 AU of pediocin PA-2 per ml as determined by a simultaneous assay on the sensitive wild-type strain. DNA and protein analysis of the resistant and susceptible strains were carried out using silver-stained amplified fragment length polymorphism (ssAFLP) and one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Two-dimensional SDS-PAGE clearly showed a 35-kDa protein which was present in the sensitive but absent from the resistant strain. The N-terminal end of the 35-kDa protein was sequenced and found to have an 83% homology to the mannose-specific phosphotransferase system enzyme IIAB of Streptococcus salivarius. PMID:10877813

  17. Absence of a putative mannose-specific phosphotransferase system enzyme IIAB component in a leucocin A-resistant strain of Listeria monocytogenes, as shown by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

    PubMed

    Ramnath, M; Beukes, M; Tamura, K; Hastings, J W

    2000-07-01

    Leucocin A is a class IIa bacteriocin produced by Leuconostoc spp. that has previously been shown to inhibit the growth of Listeria monocytogenes. A spontaneous resistant mutant of L. monocytogenes was isolated and found to be resistant to leucocin A at levels in excess of 2 mg/ml. The mutant showed no significant cross-resistance to nontype IIa bacteriocins including nisaplin and ESF1-7GR. However, there were no inhibition zones found on a lawn of the mutant when challenged with an extract containing 51,200 AU of pediocin PA-2 per ml as determined by a simultaneous assay on the sensitive wild-type strain. DNA and protein analysis of the resistant and susceptible strains were carried out using silver-stained amplified fragment length polymorphism (ssAFLP) and one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. Two-dimensional SDS-PAGE clearly showed a 35-kDa protein which was present in the sensitive but absent from the resistant strain. The N-terminal end of the 35-kDa protein was sequenced and found to have an 83% homology to the mannose-specific phosphotransferase system enzyme IIAB of Streptococcus salivarius. PMID:10877813

  18. Isolation and characterization by immunofluorescence, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot, restriction fragment length polymorphism-PCR, 16S rRNA gene sequencing, and pulsed-field gel electrophoresis of Rochalimaea quintana from a patient with bacillary angiomatosis.

    PubMed Central

    Maurin, M; Roux, V; Stein, A; Ferrier, F; Viraben, R; Raoult, D

    1994-01-01

    Rochalimaea quintana was isolated from the blood of a French human immunodeficiency virus-infected patient with bacillary angiomatosis. The isolate showed the typical growth characteristics of Rochalimaea species and was inert when typical biochemical testing was used. The purpose of the present work was to characterize and compare this new isolate with reference strains of R. quintana, Rochalimaea vinsonii, and Rochalimaea henselae by using immunofluorescence, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot (immunoblot), restriction fragment length polymorphism-PCR of the citrate synthase gene, 16S rRNA gene sequencing, and pulsed-field gel electrophoresis. SDS-PAGE, Western blot, restriction fragment length polymorphism-PCR with TaqI enzyme, and 16S rRNA gene sequencing could differentiate the three Rochalimaea species and allowed characterization of the French isolate as R. quintana. However, identification of the Rochalimaea isolate to the species level was more easily obtained by immunofluorescence with specific murine antisera. Pulsed-field gel electrophoresis allowed differentiation of the French R. quintana isolate from R. quintana Fuller and may serve as an epidemiological tool. Images PMID:7519628

  19. Cavitation Rheology of Polyacrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Kundu, Santanu; Zimberlin, Jessica; Crosby, Alfred

    2008-03-01

    Cavitation rheology is a new characterization technique for the measurement of mechanical properties on small length scales, e.g. 10 -100 ?m, at any arbitrary location within a soft material. The technique involves growing a cavity at the tip of a syringe needle and monitoring the pressure of the cavity at the onset of instability. This critical pressure is directly related to the local modulus of the material. We used this technique to characterize the network mechanics of polyacrylamide hydrogel materials, a common material used in many biological applications. We compared the cavitation rheology results with that obtained from shear rheometry. This technique was used to investigate the rheological properties of gels with different dimensions and different moduli, which were obtained by varying initial monomer to water ratio. These results provide a quantitative foundation for the extension of this technique to in vivo characterization of biological tissues.

  20. Analysis of Mutant SOD1 Electrophoretic Mobility by Blue Native Gel Electrophoresis; Evidence for Soluble Multimeric Assemblies

    PubMed Central

    Brown, Hilda H.; Borchelt, David R.

    2014-01-01

    Mutations in superoxide dismutase 1 (SOD1) cause familial forms of amyotrophic lateral sclerosis (fALS). Disease causing mutations have diverse consequences on the activity and half-life of the protein, ranging from complete inactivity and short half-life to full activity and long-half-life. Uniformly, disease causing mutations induce the protein to misfold and aggregate and such aggregation tendencies are readily visualized by over-expression of the proteins in cultured cells. In the present study we have investigated the potential of using immunoblotting of proteins separated by Blue-Native gel electrophoresis (BNGE) as a means to identify soluble multimeric forms of mutant protein. We find that over-expressed wild-type human SOD1 (hSOD1) is generally not prone to form soluble high molecular weight entities that can be separated by BNGE. For ALS mutant SOD1, we observe that for all mutants examined (A4V, G37R, G85R, G93A, and L126Z), immunoblots of BN-gels separating protein solubilized by digitonin demonstrated varied amounts of high molecular weight immunoreactive entities. These entities lacked reactivity to ubiquitin and were partially dissociated by reducing agents. With the exception of the G93A mutant, these entities were not reactive to the C4F6 conformational antibody. Collectively, these data demonstrate that BNGE can be used to assess the formation of soluble multimeric assemblies of mutant SOD1. PMID:25121776

  1. Ternary complex formation by vaccinia virus RNA polymerase at an early viral promoter: analysis by native gel electrophoresis.

    PubMed Central

    Hagler, J; Shuman, S

    1992-01-01

    We have resolved, by native gel electrophoresis, two intermediates in the transcription of a vaccinia virus early gene by the virus-encoded RNA polymerase. Polymerase holoenzyme containing the vaccinia virus early transcription factor (VETF) forms a complex of VETF bound to the promoter as the first step in a pathway leading to establishment of a committed ternary elongation complex. Formation of the VETF-DNA complex is stimulated by magnesium but is uninfluenced by nucleoside triphosphates. A stable binary complex of RNA polymerase bound to DNA is not detected. Assembly of a gel-stable polymerase-DNA complex depends on conditions permissive for RNA synthesis. Nucleotide omission experiments suggest that at least a tetrameric RNA must be made before a ternary complex is stabilized. RNA analysis indicates that complexes containing nascent transcripts 20 nucleotides long are stable and active. Ternary complex formation requires hydrolyzable ATP. This is consistent with an essential role for the ATPase activity of VETF at a step subsequent to DNA binding, as proposed by Broyles (S. S. Broyles, J. Biol. Chem. 266:15545-15548, 1991). The ternary complex, once formed, is resistant to dissociation by competitor DNA, as well as by salt, Sarkosyl, and heparin. The effects of these inhibitory agents on transcription complex formation suggest that they target different steps in the assembly pathway. Images PMID:1373199

  2. Electrically controlled polymeric gel actuators

    Microsoft Academic Search

    Douglas B. Adolf; Mohsen Shahinpoor; Daniel J. Segalman; Walter R. Witkowski

    1993-01-01

    Electrically controlled polymeric gel actuators or synthetic muscles capable of undergoing substantial expansion and contraction when subjected to changing pH environments, temperature, or solvent. The actuators employ compliant containers for the gels and their solvents. The gels employed may be cylindrical electromechanical gel fibers such as polyacrylamide fibers or a mixture of poly vinyl alcohol-polyacrylic acid arranged in a parallel

  3. Electrically controlled polymeric gel actuators

    Microsoft Academic Search

    D. B. Adolf; M. Shahinpoor; D. J. Segalman; W. R. Witkowski

    1993-01-01

    Electrically controlled polymeric gel actuators or synthetic muscles are described capable of undergoing substantial expansion and contraction when subjected to changing pH environments, temperature, or solvent. The actuators employ compliant containers for the gels and their solvents. The gels employed may be cylindrical electromechanical gel fibers such as polyacrylamide fibers or a mixture of poly vinyl alcohol-polyacrylic acid arranged in

  4. SYPRO Ruby Protein Gel Stain Advanced staining technology for 2-D gels and proteomics

    E-print Network

    Lebendiker, Mario

    SYPRO Ruby Protein Gel Stain Advanced staining technology for 2-D gels and proteomics ® Detection steps Broad linear quantitation range and consistent gel-to-gel staining allow for accurate protein especially for the analysis of proteins in 2-D polyacrylamide gels, SYPRO Ruby protein gel stain is ideal

  5. Delayed polyacrylamide gelation process for oil recovery applications

    SciTech Connect

    Sydansk, R.D.

    1988-05-17

    A process for delaying the gelation rate of a gelation solution to form a continuous crosslinked polymer gel utilized for a hydrocarbon recovery application in a treatment region of a hydrocarbon-bearing formation below an earthen surface penetrated by a wellbore in communication with the region is described, comprising the steps of: (a) predetermining a delayed gelation rate required of the continuous crosslinked polymer gel to perform the hydrocarbon recovery application; (b) preparing a chromic carboxylate complex in a solution consisting essentially of a solvent, at least one chromic species, and at least one acetate species; (c) preselecting the polyacrylamide wherein the degree of hydrolysis of amide groups to carboxylate groups in the polyacrylamide is less than about 5.0% such that the preselected polyacrylamide gels at the predetermined delayed gelation rate when admixed with the complex in solution; (d) preparing the gelation solution at the earthen surface by admixing the preselected polyacrylamide and the complex in solution; (e) injecting the gelation solution into the treatment region via the wellbore; and (f) forming the continuous crosslinked polymer gel in situ from the gelation solution at the predetermined delayed gelation rate required to perform the hydrocarbon recovery application.

  6. Identification, purification, and characterization of subunits of cAMP-dependent protein kinase in human testis. Reverse mobilities of human RII alpha and RII beta on sodium dodecyl sulfate-polyacrylamide gel electrophoresis compared with rat and bovine RIIs.

    PubMed

    Skålhegg, B S; Landmark, B; Foss, K B; Lohmann, S M; Hansson, V; Lea, T; Jahnsen, T

    1992-03-15

    We have previously identified and characterized regulatory (R) subunits of cyclic AMP-dependent protein kinase, particularly the RII subunits in rat tissues (Jahnsen, T., Lohmann, S. M., Walter, U., Hedin, L., and Richards, J. S. (1985) J. Biol. Chem. 260, 15980-15987; Jahnsen, T., Hedin, L., Lohmann, S. M., Walter, U., and Richards, J. S. (1986) J. Biol. Chem. 261, 6637-6639; Jahnsen, T., Hedin, L., Kidd, V. J., Beattie, W. G., Lohmann, S. M., Walter, U., Durica, J., Schulz, T. Z., Schiltz, E., Browner, M., Lawrence, C. B., Goldman, D., Ratoosh, S. L., and Richards, J. S. (1986) J. Biol. Chem. 261, 12352-12361). These studies showed that rat RII alpha and RII beta had apparent molecular masses of 54 and 52 kDa, respectively. The aim of the present study was to purify and characterize cAMP-dependent protein kinase R subunits in human testis and to examine which of the subunits (mRNAs and proteins) are present in this tissue. Our results show that human testis contains mRNAs for five out of the seven known subunits of cAMP-dependent protein kinase. We observed strong expression of mRNAs for RI alpha (1.5 and 3.2 kilobases (kb)), RII alpha (2.2, 2.4, and 7.0 kb), and RII beta (3.3 kb). We also demonstrated mRNAs for two of the three catalytic subunits, C alpha (2.7 kb) and C gamma (1.7 kb). Purification of R subunits by DEAE-cellulose and cAMP affinity chromatography revealed three distinct forms with apparent molecular masses of 49, 51, and 53 kDa, respectively. Characterization of these R subunits by their 8-azido-cAMP photoaffinity labeling and immunoreactivity, as well as by a phosphorylation-dependent mobility shift on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), indicated subunit sizes of RII beta (53 kDa) greater than RII alpha dephosphoform (51 kDa) greater than RI alpha (49 kDa). This conclusion was verified by the analysis of RII subunits produced by in vitro transcription/translation of full-length cDNAs for both human RII alpha and RII beta in wheat germ lysates. The in vitro translated products were the same size as the purified human testis subunits, and only the smallest RII subunit (RII alpha) revealed a distinct mobility shift on SDS-PAGE after phosphorylation/dephosphorylation. This study supports the conclusion that the mobilities of human RII subunits (RII alpha, RII beta) on SDS-PAGE are reversed in contrast with those of other species such as rat and bovine.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1544918

  7. Effect of Shear on Gelation of Polyacrylamide-Chromium Acetate Gelant in a Circular Tube

    E-print Network

    Li, Xianping

    2010-11-26

    This research studies the gelation and flow properties of a partially hydrolyzed polyacrylamide (HPAM)-chromium acetate gel system under shear conditions. Gelation was observed in steady shear on a rheometer and during injection through a 1,031-ft...

  8. An Investigation of In Situ Gelation of a Polyacrylamide/Chromium(III) System in Porous Media

    E-print Network

    Montes, Antonio

    1992-04-01

    . In this research, a suitable chromium(III)-polyacrylamide system was identified to allow the experimental investigation of gel polymer displacements under laboratory conditions. The flow and gelation behavior of the chemical system identified was observed...

  9. Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis and Western Blotting Comparisons of Purified Myofibrils and Whole Muscle Preparations for Evaluating Titin and Nebulin in Postmortem Bovine Muscle1,2

    Microsoft Academic Search

    Elisabeth Huff-Lonergan; Tomiko Mitsuhashi; F. C. Parrish; Richard M. Robson

    Purified myofibril (MF) and homogenized whole muscle (WM) samples were prepared from A maturity market steers. Samples were removed at 0, 1, 3, 7, 14, and 28 d postmortem. The MF and WM samples from all steers were analyzed by SDS-PAGE (5% gels) and by Western blot analysis using monoclonal antibodies to titin and nebulin. The rates of degradation of

  10. Isoforms of a cuticular protein from larvae of the meal beetle, Tenebrio molitor, studied by mass spectrometry in combination with Edman degradation and two-dimensional polyacrylamide gel electrophoresis.

    PubMed

    Haebel, S; Jensen, C; Andersen, S O; Roepstorff, P

    1995-03-01

    Simultaneous sequencing, using a combination of mass spectrometry and Edman degradation, of three approximately 15-kDa variants of a cuticular protein extracted from the meal beetle Tenebrio molitor larva is demonstrated. The information obtained by matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) time-course monitoring of enzymatic digests was found essential to identify the differences among the three variants and for alignment of the peptides in the sequence. To determine whether each individual insect larva contains all three protein variants, proteins extracted from single animals were separated by two-dimensional gel electrophoresis, electroeluted from the gel spots, and analyzed by MALDI MS. Molecular weights of the proteins present in each sample could be obtained, and mass spectrometric mapping of the peptides after digestion with trypsin gave additional information. The protein isoforms were found to be allelic variants. PMID:7795523

  11. Spring-loaded polymeric gel actuators

    DOEpatents

    Shahinpoor, Mohsen (Albuquerque, NM)

    1995-01-01

    Spring-loaded electrically controllable polymeric gel actuators are disclosed. The polymeric gels can be polyvinyl alcohol, polyacrylic acid, or polyacrylamide, and are contained in an electrolytic solvent bath such as water plus acetone. The action of the gel is mechanically biased, allowing the expansive and contractile forces to be optimized for specific applications.

  12. Spring-loaded polymeric gel actuators

    DOEpatents

    Shahinpoor, M.

    1995-02-14

    Spring-loaded electrically controllable polymeric gel actuators are disclosed. The polymeric gels can be polyvinyl alcohol, polyacrylic acid, or polyacrylamide, and are contained in an electrolytic solvent bath such as water plus acetone. The action of the gel is mechanically biased, allowing the expansive and contractile forces to be optimized for specific applications. 5 figs.

  13. Tough and highly stretchable polyacrylamide nanocomposite hydrogels with chitin nanocrystals.

    PubMed

    Liu, Mingxian; Huang, Jiandong; Luo, Binghong; Zhou, Changren

    2015-07-01

    Chitin nanocrystals (CNCs) that were 10-20nm wide and 100-500nm long were synthetized via acidolysis and characterized with various methods. To avoid the flocculation of CNCs in the initiator solution during acrylamide polymerization, chitosan was selected as a surface modifier. The chitosan-modified CNCs were employed as multifunctional crosslinkers for the polyacrylamide (PAAm) nanocomposite (NC) hydrogels. The NC gels were tough and stretchable; for example, the maximum tensile strength and the elongation at break of the NC gels were 90kPa and 3070%, respectively. The dynamic shear modulus of the NC gels was also significantly higher than that of the PAAm. The NC gels were nearly free of residual strain after 2000% elongation. The microstructures of all NC gels were porous, with a pore size of 20-100?m. The maximum equilibrium swelling degree of the NC gels was 3800%. The improvement in the properties of the NC gels is attributed to the good dispersion of CNCs and the interfacial interactions in the composites. This work developed PAAm NC hydrogels with CNCs for application as absorbent or biomedical material due to the high mechanical properties, high absorb ability and good biocompatibility of CNCs and explored new applications for CNCs as well. PMID:25841364

  14. Studies of muscle proteins in embryonic myocardial cells of cardiac lethal mutant mexican axolotls (Ambystoma mexicanum) by use of heavy meromyosin binding and sodium dodecyl sulfate polyacrylamide gel electrophoresis

    PubMed Central

    1976-01-01

    In the Mexican axolotl Ambystoma mexicanum recessive mutant gene c, by way of abnormal inductive processes from surrounding tissues, results in an absence of embryonic heart function. The lack of contractions in mutant heart cells apparently results from their inability to form normally organized myofibrils, even though a few actin-like (60-A) and myosin-like (150-A) filaments are present. Amorphous "proteinaceous" collections are often visible. In the present study, heavy meromyosin (HMM) treatment of mutant heart tissue greatly increases the number of thin filaments and decorates them in the usual fashion, confirming that they are actin. The amorphous collections disappear with the addition of HMM. In addition, an analysis of the constituent proteins of normal and mutant embryonic hearts and other tissues is made by sodium dodecyl sulfate (SDS) gel electrophoresis. These experiments are in full agreement with the morphological and HMM binding studies. The gels show distinct 42,000-dalton bands for both normal and mutant hearts, supporting the presence of normal actin. During early developmental stages (Harrison's stage 34) the cardiac tissues in normal and mutant siblings have indistinguishable banding patterns, but with increasing development several differences appear. Myosin heavy chain (200,000 daltons) increases substantially in normal hearts during development but very little in mutants. Even so the quantity of 200,000-dalton protein in mutant hearts is significantly more than in any of the nonmuscle tissues studied (i.e. gut, liver, brain). Unlike normal hearts, the mutant hearts lack a prominent 34,000-dalton band, indicating that if mutants contain muscle tropomyosin at all, it is present in drastically reduced amounts. Also, mutant hearts retain large amounts of yolk proteins at stages when the platelets have virtually disappeared from normal hearts. The morphologies and electrophoresis patterns of skeletal muscle from normal and mutant siblings are identical, confirming that gene c affects only heart muscle differentiation and not skeletal muscle. The results of the study suggest that the precardiac mesoderm in cardiac lethal mutant axolotl embryos initiates but then fails to complete its differentiation into functional muscle tissue. It appears that this single gene mutation, by way of abnormal inductive processes, affects the accumulation and organization of several different muscle proteins, including actin, myosin, and tropomyosin. PMID:1107335

  15. Native agarose gel electrophoresis and electroelution: A fast and cost-effective method to separate the small and large hepatitis B capsids.

    PubMed

    Yoon, Kam Yee; Tan, Wen Siang; Tey, Beng Ti; Lee, Khai Wooi; Ho, Kok Lian

    2013-01-01

    Hepatitis B core antigen (HBcAg) expressed in Escherichia coli is able to self-assemble into large and small capsids comprising 240 (triangulation number T = 4) and 180 (triangulation number T = 3) subunits, respectively. Conventionally, sucrose density gradient ultracentrifugation and SEC have been used to separate these capsids. However, good separation of the large and small particles with these methods is never achieved. In the present study, we employed a simple, fast, and cost-effective method to separate the T = 3 and T = 4 HBcAg capsids by using native agarose gel electrophoresis followed by an electroelution method (NAGE-EE). This is a direct, fast, and economic method for isolating the large and small HBcAg particles homogenously based on the hydrodynamic radius of the spherical particles. Dynamic light scattering analysis demonstrated that the T = 3 and T = 4 HBcAg capsids prepared using the NAGE-EE method are monodisperse with polydispersity values of ?15% and ?13%, respectively. ELISA proved that the antigenicity of the capsids was not affected in the purification process. Overall, NAGE-EE produced T = 3 and T = 4 capsids with a purity above 90%, and the recovery was 34% and 50%, respectively (total recovery of HBcAg is ?84%), and the operation time is 15 and 4 times lesser than that of the sucrose density gradient ultracentrifugation and SEC, respectively. PMID:23161478

  16. Recent Applications of Polyacrylamide as Biomaterials

    Microsoft Academic Search

    Tsung-Hua Yang

    2008-01-01

    The synthetic polymer, polyacrylamide derived from acrylamide monomer, was originally introduced for use as a support matrix for electrophoresis in 1959. Later, because of its applicability and economy, polyacrylamide has found widespread applications ranging from microanalysis to macro-fractionation for proteins, nucleic acid, and other biomolecules. On the other hand, recent years also witnessed increasing research interests in the potential of

  17. Electrically controlled polymeric gel actuators

    DOEpatents

    Adolf, Douglas B. (Albuquerque, NM); Shahinpoor, Mohsen (Albuquerque, NM); Segalman, Daniel J. (Albuquerque, NM); Witkowski, Walter R. (Albuquerque, NM)

    1993-01-01

    Electrically controlled polymeric gel actuators or synthetic muscles capable of undergoing substantial expansion and contraction when subjected to changing pH environments, temperature, or solvent. The actuators employ compliant containers for the gels and their solvents. The gels employed may be cylindrical electromechanical gel fibers such as polyacrylamide fibers or a mixture of poly vinyl alcohol-polyacrylic acid arranged in a parallel aggregate and contained in an electrolytic solvent bath such as salt water. The invention includes smart, electrically activated devices exploiting this phenomenon. These devices are capable of being manipulated via active computer control as large displacement actuators for use in adaptive structure such as robots.

  18. Electrically controlled polymeric gel actuators

    DOEpatents

    Adolf, D.B.; Shahinpoor, M.; Segalman, D.J.; Witkowski, W.R.

    1993-10-05

    Electrically controlled polymeric gel actuators or synthetic muscles are described capable of undergoing substantial expansion and contraction when subjected to changing pH environments, temperature, or solvent. The actuators employ compliant containers for the gels and their solvents. The gels employed may be cylindrical electromechanical gel fibers such as polyacrylamide fibers or a mixture of poly vinyl alcohol-polyacrylic acid arranged in a parallel aggregate and contained in an electrolytic solvent bath such as salt water. The invention includes smart, electrically activated devices exploiting this phenomenon. These devices are capable of being manipulated via active computer control as large displacement actuators for use in adaptive structure such as robots. 11 figures.

  19. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  20. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  1. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  2. 21 CFR 173.10 - Modified polyacrylamide resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...polyacrylamide resin is produced by the copolymerization of acrylamide with not more than 5-mole percent ?-methacrylyloxyethy-ltrimethylammonium...polyacrylamide resin contains not more than 0.05 percent residual acrylamide. (c) The modified polyacrylamide resin is used as...

  3. A Simple Vertical Slab Gel Electrophoresis Apparatus.

    ERIC Educational Resources Information Center

    Carter, J. B.; And Others

    1983-01-01

    Describes an inexpensive, easily constructed, and safe vertical slab gel kit used routinely for sodium dodecyl sulphate-polyacrylamide gel electrophoresis research and student experiments. Five kits are run from a single transformer. Because toxic solutions are used, students are given plastic gloves and closely supervised during laboratory…

  4. Very slow propagating mode at audiofrequencies in gel J. C. Bacri, J. Dumas and A. Levelut

    E-print Network

    Boyer, Edmond

    Hz) dans un gel polyacrylamide à 10 %. Nous avons trouvé une vitesse de phase très faible (2,3 m/s in a 10 % polyacrylamide gel. The phase velocity, which is directly related to the polymer shear constant, is very low (2.3 m/s). A polymer network viscosity has also been measured. LE JOURNAL DE PHYSIQUE

  5. Detection of Polymorphisms of Human DNA by Gel Electrophoresis as Single-Strand Conformation Polymorphisms

    Microsoft Academic Search

    Masato Orita; Hiroyuki Iwahana; Hiroshi Kanazawa; Kenshi Hayashi; Takao Sekiya

    1989-01-01

    We developed mobility shift analysis of single-stranded DNAs on neutral polyacrylamide gel electrophoresis to detect DNA polymorphisms. This method follows digestion of genomic DNA with restriction endonucleases, denaturation in alkaline solution, and electrophoresis on a neutral polyacrylamide gel. After transfer to a nylon membrane, the mobility shift due to a nucleotide substitution of a single-stranded DNA fragment could be detected

  6. Structural characterization of immunoglobulins contained in polyacrylamide gels

    Microsoft Academic Search

    G. Virella; Maria Manuel de Freitas

    1973-01-01

    I?;s ist bekannt, dass kurzdauernde Unterbindung der Aorta (40 rain) unter den Nierenarterien bei einigen Tieren zur Rigidit~t der Hinterextremitg, ten fiihrt 1. Wit konnten zeigen, dass bei Ratten diese Art von Rigidit~t durch Glyzin (G) verhindert werden kann 2. Die Unterbindung der Aorta fiihrt aber auch zum Verschwinden yon G und zur ZerstSrung der Interneuronen in der medulla spinalis,

  7. Blue native PAGE

    Microsoft Academic Search

    Ilka Wittig; Hans-Peter Braun; Hermann Schägger

    2006-01-01

    Blue native PAGE (BN-PAGE) can be used for one-step isolation of protein complexes from biological membranes and total cell and tissue homogenates. It can also be used to determine native protein masses and oligomeric states and to identify physiological protein–protein interactions. Native complexes are recovered from gels by electroelution or diffusion and are used for 2D crystallization and electron microscopy

  8. Visual optical biosensors based on DNA-functionalized polyacrylamide hydrogels.

    PubMed

    Khimji, Imran; Kelly, Erin Y; Helwa, Youssef; Hoang, Michael; Liu, Juewen

    2013-12-15

    Biosensors are devices that can provide quantitative or semi-quantitative analytical information about target molecules, where molecular recognition is based on biomolecular interactions. In recent years, DNA has emerged as a useful molecule for biosensor development since DNA can not only recognize its complementary strand, but also metal ions, small molecules, proteins and cells utilizing DNA aptamer technology. Converting DNA binding events into useful biosensors often require sensor immobilization. Among the various materials for sensor immobilization, hydrogels are particularly attractive. Hydrogels are crosslinked hydrophilic polymer networks that undergo swelling in water. In a gel, DNA immobilization can take place in 3D, allowing for high DNA loading capacity. Hydrogels are transparent, offering low optical background. The gel volume is affected by many environmental parameters such as temperature, pH, ionic strength, and solvent composition. In this paper, we present a concise summary of recent developments in DNA-functionalized hydrogel biosensors for visual detection. Detailed methods for immobilizing DNA biosensors in monolithic polyacrylamide gels and gel microparticles are supplied. PMID:23978515

  9. Bioconversion of acrylonitrile to acrylamide using polyacrylamide entrapped cells of Rhodococcus rhodochrous PA-34.

    PubMed

    Raj, J; Prasad, S; Sharma, N N; Bhalla, T C

    2010-09-01

    The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells. PMID:20941578

  10. Templated native silk smectic gels

    NASA Technical Reports Server (NTRS)

    Jin, Hyoung-Joon (Inventor); Park, Jae-Hyung (Inventor); Valluzzi, Regina (Inventor)

    2009-01-01

    One aspect of the present invention relates to a method of preparing a fibrous protein smectic hydrogel by way of a solvent templating process, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; and collecting the resulting fibrous protein smectic hydrogel and allowing it to dry. Another aspect of the present invention relates to a method of obtaining predominantly one enantiomer from a racemic mixture, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; allowing the enantiomers of racemic mixture to diffuse selectively into the smectic hydrogel in solution; removing the smectic hydrogel from the solution; rinsing predominantly one enantiomer from the surface of the smectic hydrogel; and extracting predominantly one enantiomer from the interior of the smectic hydrogel. The present invention also relates to a smectic hydrogel prepared according to an aforementioned method.

  11. Templated Native Silk Smectic Gels

    NASA Technical Reports Server (NTRS)

    Jin, Hyoung-Joon (Inventor); Park, Jae-Hyung (Inventor); Valluzzi, Regina (Inventor)

    2013-01-01

    One aspect of the present invention relates to a method of preparing a fibrous protein smectic hydrogel by way of a solvent templating process, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; and collecting the resulting fibrous protein smectic hydrogel and allowing it to dry. Another aspect of the present invention relates to a method of obtaining predominantly one enantiomer from a racemic mixture, comprising the steps of pouring an aqueous fibrous protein solution into a container comprising a solvent that is not miscible with water; sealing the container and allowing it to age at about room temperature; allowing the enantiomers of racemic mixture to diffuse selectively into the smectic hydrogel in solution; removing the smectic hydrogel from the solution; rinsing predominantly one enantiomer from the surface of the smectic hydrogel; and extracting predominantly one enantiomer from the interior of the smectic hydrogel. The present invention also relates to a smectic hydrogel prepared according to an aforementioned method.

  12. Application of rod-shaped cellulose nanocrystals in polyacrylamide hydrogels.

    PubMed

    Zhou, Chengjun; Wu, Qinglin; Yue, Yiying; Zhang, Quanguo

    2011-01-01

    Rod-shaped cellulose nanocrystals (CNCs) were manufactured and used to reinforce polyacrylamide (PAM) hydrogels through in situ free-radical polymerization. The gelation process of the nanocomposite hydrogels was monitored on a rheometer using oscillatory shear. The chemical structure, morphology, swelling property, and compression strength of the formed gels were investigated. A possible mechanism for forming hydrogels was proposed. The results showed that CNCs accelerated the formation of hydrogels and increased the effective crosslink density of hydrogels. Thus CNCs were not only a reinforcing agent for hydrogel, but also acted as a multifunctional cross-linker for gelation. The shear storage modulus, compression strength and elastic modulus of the nanocomposite hydrogels were significantly improved because of good dispersion of CNCs in PAM as well as enhanced interfacial interaction between these two components. Among the CNC contents used, a loading of 6.7 w/w% led to the maximum mechanical properties for nanocomposite hydrogels. PMID:20932533

  13. Cavitation Rheology and Fracture Behavior of Polyacrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Kundu, Santanu; Crosby, Alfred

    2009-03-01

    Cavitation rheology is a new characterization technique for the measurement of mechanical properties on small length scales, e.g. 10 -1000 ?m, at any arbitrary location within a soft material. The technique involves growing a cavity at the tip of a syringe needle and monitoring the pressure of the cavity at the onset of instability. This critical pressure is directly related to the local modulus of the material. We used this technique to characterize the network mechanics of polyacrylamide hydrogel materials, a common material used in many biological applications. Gels with different moduli, which were obtained by varying initial monomer to water ratio, were investigated. As monomer concentration increased, a transition from stable cavity to fracture was observed. Applying scaling theory for gels, we modify the Lake-Thomas Theory for the fracture of crosslinked networks to relate the transition from cavitation to fracture in terms of molecular parameters. We anticipate this fundamental understanding of cavitation and fracture mechanism will be applicable to biological tissues, as well as the development of advanced soft materials

  14. Autofluorescence based visualization of proteins from unstained native-PAGE

    NASA Astrophysics Data System (ADS)

    Manjunath, S.; Rao, Bola Sadashiva S.; Satyamoorthy, Kapaettu; Mahato, Krishna Kishore

    2015-03-01

    Proteins are the most diverse and functionally active biomolecules in the living system. In order to understand their diversity and dynamic functionality, visualization in native form without altering structural and functional properties during the separation from the complex mixtures is very much essential. In the present study, a sensitive methodology for optimal visualization of unstained or untagged proteins in native poly-acrylamide gel electrophoresis (N-PAGE) has been developed where, concentration of the acrylamide and bis-acrylamide mixture, Percentage of the gel, fixing of the N-PAGE by methanol: acetic acid: water and washing of the gel in the mili-Q water has been optimized for highest sensitivity using laser induced autofluorescence. The outcome with bovine serum albumin (BSA) in PAGE was found to be highest at acrylamide and bis-acrylamide concentrations of 29.2 and 0.8 respectively in 12% N-PAGE. After the electrophoresis run, washing of the N-PAGE immediately with miliQ water for 12 times and eliminating the methanol: acetic acid: water, fixing of the N-PAGE yielded better sensitivity of visualization. Using the above methodology 25ng of BSA protein band in PAGE was clearly identified by the technique. The currently used staining techniques for the visualization of proteins are coomassie brilliant blue and silver staining, have the sensitivity of 100ng and 5ng respectively. The current methodology was found to be more sensitive as compared to coomassie staining and less sensitive compared to silver staining respectively. The added advantage of this methodology is the faster visualization of proteins without altering their structure and functional properties.

  15. Conducting Polymer Electrodes for Gel Electrophoresis

    PubMed Central

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D.

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that ?-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation. PMID:24586761

  16. New gel phantoms simulating optical properties of biological tissue 

    E-print Network

    Lee, Mija

    1997-01-01

    Gel phantoms made of polyacrylamide gel, India ink, and TiO2 were prepared to simulate biological tissues in optical properties. India ink and TiO2were used to imitate the absorption and scattering properties, respectively, of biological tissues...

  17. Performance of 18 polymers in aluminum citrate colloidal dispersion gels

    SciTech Connect

    Smith, J.E.

    1995-11-01

    Colloidal dispersion gels are made up of low concentrations of polymer and aluminum citrate in water. These gels, which are mixed as a homogeneous solution at the surface, provide a valuable tool for in-depth blockage of high permeability regions of rock in heterogeneous reservoirs. Performance of colloidal dispersion gels depends strongly on the type and quality of polymer used. This paper provides an overview of the performance of 18 different polymers in colloidal dispersion gels. 14 of the polymers were partially hydrolyzed polyacrylamides or AMPS polymers in dry crystalline form with varying degrees of hydrolysis and molecular weight. The group also includes one cationic polyacrylamide, one carboxymethyl cellulose, one partially hydrolyzed polyacrylamide in emulsion form and one polysaccharide in dry form. Gels were mixed with the polymers at two polymer concentrations, three polymer:aluminum ratios and in different concentrations of potassium chloride. The gels were quantitatively tested at 1, 7, 14 and 28 days after crosslinking using the transition pressure test, which is a screen flow resistance test. Of the six polymer types tested, only the dry partially hydrolyzed polyacrylamides and AMPS polymers formed colloidal dispersion gels. Gel strength generally increased with increasing anionic charge and molecular weight; however, the manner in which the polymer is manufactured and the impurities present in the polymer also play roles which are more significant than originally expected.

  18. Purification of radiolabeled RNA products using denaturing gel electrophoresis

    PubMed Central

    Adachi, Hironori; Yu, Yi-Tao

    2014-01-01

    This unit discusses a basic method for purification of radiolabeled RNAs using denaturing polyacrylamide gel electrophoresis. The method consists of a number of experimental procedures, including total RNA preparation from yeast cells, isolation of a specific RNA from total yeast RNA, RNA 3' terminal labeling using nucleotide (5’[32P]pCp) addition (via ligation), denaturing (8 M urea) polyacrylamide gel electrophoresis, and RNA extraction from the gel slice. Key points for achieving good electrophoretic separation of RNA are also discussed. PMID:24510465

  19. Agarose gel shift assay reveals that calreticulin favors substrates with a quaternary structure in solution.

    PubMed

    Boelt, Sanne Grundvad; Houen, Gunnar; Højrup, Peter

    2015-07-15

    Here we present an agarose gel shift assay that, in contrast to other electrophoresis approaches, is loaded in the center of the gel. This allows proteins to migrate in either direction according to their isoelectric points. Therefore, the presented assay enables a direct visualization, separation, and prefractionation of protein interactions in solution independent of isoelectric point. We demonstrate that this assay is compatible with immunochemical methods and mass spectrometry. The assay was used to investigate interactions with several potential substrates for calreticulin, a chaperone that is involved in different biological aspects through interaction with other proteins. The current analytical assays used to investigate these interactions are mainly spectroscopic aggregation assays or solid phase assays that do not provide a direct visualization of the stable protein complex but rather provide an indirect measure of interactions. Therefore, no interaction studies between calreticulin and substrates in solution have been investigated previously. The results presented here indicate that calreticulin has a preference for substrates with a quaternary structure and primarily ?-sheets in their secondary structure. It is also demonstrated that the agarose gel shift assay is useful in the study of other protein interactions and can be used as an alternative method to native polyacrylamide gel electrophoresis. PMID:25908558

  20. The effects of shear history on the gelation of polyacrylamide/chromium(VI)/thiourea solutions

    SciTech Connect

    Bhaskar, R.K.; Stinson, J.A.; Willhite, G.P.; Thiele, J.L.

    1988-11-01

    The influence of shearing during gelation on the gelation rate of a polyacrylamide/chromium(VI)thiourea solution was studied. Gelations were carried out under steady-state shear, oscillatory shear, and programmed shear. When shear rate was constant throughout the experiment, gels formed more slowly at high than at low shear rates. This behavior is opposite to that observed with polyacrylamide/chromium(VI)bisulfite solutions, where increased shear rates led to faster gelations. The gelation mechanism is believed to involve at least two chemical reaction steps: reduction of chromium(VI) to chromium(III) followed by crosslinking of the polymer by chromium(III). In gelation with bisulfite as the reducing agent, chromium(III) is generated rapidly, and the rate-determining step (which may be polymer-diffusion controlled) is probably the crosslinking of polymer by chromium(III). In contrast, chromium(III) is generated relatively slowly in gelation with thiourea as the reducing agent, and the rate-determining step appears to be the redox reaction. The conclusion that the rate of gelation and strength of the gel formed for the gelation of polyacrylamide by chromium(III) are strongly influenced by the total shear history of the solution has important implications for design of field applications of gelled polymers in EOR. The evaluation of gel characteristics is quiescent bottle tests, a common practice, may not be sufficient to determine whether a gel of the desired strength can be obtained in situ because all gelling solutions must be subjected to considerable shearing during injection.

  1. Microfabricated Polyacrylamide Devices for the Controlled Culture of Growing Cells and Developing Organisms

    PubMed Central

    Gude, Sebastian; Recouvreux, Pierre; van Zon, Jeroen S.; Tans, Sander J.

    2013-01-01

    The ability to spatially confine living cells or small organisms while dynamically controlling their aqueous environment is important for a host of microscopy applications. Here, we show how polyacrylamide layers can be patterned to construct simple microfluidic devices for this purpose. We find that polyacrylamide gels can be molded like PDMS into micron-scale structures that can enclose organisms, while being permeable to liquids, and transparent to allow for microscopic observation. We present a range of chemostat-like devices to observe bacterial and yeast growth, and C. elegans nematode development. The devices can integrate PDMS layers and allow for temporal control of nutrient conditions and the presence of drugs on a minute timescale. We show how spatial confinement of motile C. elegans enables for time-lapse microscopy in a parallel fashion. PMID:24086559

  2. Graft Copolymerization of Pectin with Polyacrylamide

    Microsoft Academic Search

    R. K. Mishra; P. B. Sutar; J. P. Singhal; A. K. Banthia

    2007-01-01

    In the present study, an attempt has been made to modify pectin by grafting polyacrylamide using ammonium ceric sulphate as initiator. The effect of various variables like initiator concentration, monomer concentration, temperature and time has been studied. The grafted copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), organic elemental analysis, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). FT-IR

  3. Increase in local protein concentration by field-inversion gel electrophoresis

    Microsoft Academic Search

    Henghang Tsai; Teck Yew Low; Steve Freeby; Aran Paulus; Kalpana Ramnarayanan; Chung-pui Paul Cheng; Hon-chiu Eastwood Leung

    2007-01-01

    BACKGROUND: Proteins that migrate through cross-linked polyacrylamide gels (PAGs) under the influence of a constant electric field experience negative factors, such as diffusion and non-specific trapping in the gel matrix. These negative factors reduce protein concentrations within a defined gel volume with increasing migration distance and, therefore, decrease protein separation efficiency. Enhancement of protein separation efficiency was investigated by implementing

  4. Impacts of Timing of Crosslinker Addition on Water Shut Off Polymer Gel Properties 

    E-print Network

    Shriwal, Prashant

    2012-07-16

    In preparation of gelant solution for making crosslinked polymer gels for water shutoff applications unpublished experiments plus chemical intuition suggest that, unless hydrolyzed polyacrylamide (HPAM) polymer is fully hydrated before addition...

  5. Recent advances in gel-based proteome profiling techniques

    Microsoft Academic Search

    Yi Hu; Xuan Huang; Grace Y. J. Chen; Shao Q. Yao

    2004-01-01

    This review focuses on recent developments in gel-based proteomics techniques. By combining traditional sodium dodecyl sulfate-polyacrylamide\\u000a gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoretic techniques with recent advances in protein labeling\\u000a using different classes of molecules (i.e., fluorescent dyes, chemical probes, radioisotopes), new technologies have been\\u000a developed that allow for high-throughput studies of proteins at the whole-proteome scale.

  6. Matrix-assisted laser desorption\\/ionization time of flight mass spectrometry peptide mass fingerprints and post source decay: a tool for the identification and analysis of phloem proteins from Cucurbita maxima Duch. separated by two-dimensional polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Sophie Haebel; Julia Kehr

    2001-01-01

    A combination of gel electrophoresis and mass spectrometry was used to analyze the soluble proteins from phloem sap of Cucurbita maxima Duch. Phloem proteins were separated using two-dimensional gel electrophoresis. Coomassie-stained spots were cut out and subjected to tryptic digestion. To identify proteins, peptide mass fingerprints were determined by matrix-assisted laser desorption\\/ionization time of flight (MALDI-TOF) mass spectrometry. In addition,

  7. Adsorption characteristics of polyacrylamide and sulfonate-containing polyacrylamide copolymers on sodium kaolinite. [Gamma radiation

    SciTech Connect

    Hollander, A.F.; Somasundaran, P.; Gryte, C.C.

    1981-07-01

    Polyacrylamide and its copolymer containing 6.8 mole % 2-acrylamido-2-methylpropane sulfonic acid were prepared by an irradiation-initiated precipitation polymerization technique. The polymer was characterized by intrinsic viscosity under conditions similar to those used during adsorption measurements. Hydrolytic degradation of the polyacrylamide was found to be negligible under conditions used. The adsorption substrate, sodium kaolinite, was prepared by extensive ion exchange treatment. Equilibrium adsorption of the polymers on the sodium kaolinite was made as a function of polymer concentration, solution pH, ionic strength, and temperature.

  8. A simple and cost-effective solid-phase protein nano-assay using polyacrylamide-coated glass plates.

    PubMed

    Krajewski, Wladyslaw A

    2015-02-01

    A new solid-phase protein nano-assay is suggested for simple and sensitive estimation of protein content in sample buffers (a 1-?l sample is sufficient for analysis). The assay is different from conventional "on-filter" assays in that it uses inexpensive fully transparent polyacrylamide gel (PAAG)-coated glass plates as solid support and, thus, combines the convenience of "on-membrane" staining with the sensitivity and ease of documentation of "in-gel" staining (and, therefore, is especially suited for standard lab gel documentation systems). The PAAG plates assay is compatible with all dyes for in-gel protein staining. Depending on the sensitivity of the staining protocol, the assay can be used in macro-, micro-, and nano-assay formats. We also describe a low-cost two-component colloidal Coomassie brilliant blue G-250 (CBB G-250) staining protocol for fast quantitative visualization of proteins spotted on a PAAG plate (the detection limit is up to 2 ng of proteins even when using a Nikon CoolPix digital camera and white light transilluminator instead of a gel scanner). The suggested colloidal CBB G-250 protocol could also be used for visualizing nano-amounts of proteins in polyacrylamide gels. The PAAG plate assay could be useful for proteomic applications and, in general, for all cases where a fast, sensitive, and easily documentable cost-effective solid-phase protein assay is required. PMID:25449300

  9. Radio-synthesized polyacrylamide hydrogels for proteins release

    NASA Astrophysics Data System (ADS)

    Ferraz, Caroline C.; Varca, Gustavo H. C.; Lopes, Patricia S.; Mathor, Monica B.; Lugão, Ademar B.

    2014-01-01

    The use of hydrogels for biomedical purposes has been extensively investigated. Pharmaceutical proteins correspond to highly active substances which may be applied for distinct purposes. This work concerns the development of radio-synthesized hydrogel for protein release, using papain and bovine serum albumin as model proteins. The polymer was solubilized (1% w/v) in water and lyophilized. The proteins were incorporated into the lyophilized polymer and the hydrogels were produced by simultaneous crosslinking and sterilization using ?-radiation under frozen conditions. The produced systems were characterized in terms of swelling degree, gel fraction, crosslinking density and evaluated according to protein release, bioactivity and cytotoxicity. The hydrogels developed presented different properties as a function of polymer concentration and the optimized results were found for the samples containing 4-5% (w/v) polyacrylamide. Protein release was controlled by the electrostatic affinity of acrylic moieties and proteins. This selection was based on the release of the proteins during the experiment period (up to 50 h), maintenance of enzyme activity and the nanostructure developed. The system was suitable for protein loading and release and according to the cytotoxic assay it was also adequate for biomedical purposes, however this method was not able to generate a matrix with controlled pore sizes.

  10. Increase in local protein concentration by field-inversion gel electrophoresis

    PubMed Central

    Tsai, Henghang; Low, Teck Yew; Freeby, Steve; Paulus, Aran; Ramnarayanan, Kalpana; Cheng, Chung-pui Paul; Leung, Hon-chiu Eastwood

    2007-01-01

    Background Proteins that migrate through cross-linked polyacrylamide gels (PAGs) under the influence of a constant electric field experience negative factors, such as diffusion and non-specific trapping in the gel matrix. These negative factors reduce protein concentrations within a defined gel volume with increasing migration distance and, therefore, decrease protein separation efficiency. Enhancement of protein separation efficiency was investigated by implementing pulsed field-inversion gel electrophoresis (FIGE). Results Separation of model protein species and large protein complexes was compared between FIGE and constant field electrophoresis (CFE) in different percentages of PAGs. Band intensities of proteins in FIGE with appropriate ratios of forward and backward pulse times were superior to CFE despite longer running times. These results revealed an increase in band intensity per defined gel volume. A biphasic protein relative mobility shift was observed in percentages of PAGs up to 14%. However, the effect of FIGE on protein separation was stochastic at higher PAG percentage. Rat liver lysates subjected to FIGE in the second-dimension separation of two-dimensional polyarcylamide gel electrophoresis (2D PAGE) showed a 20% increase in the number of discernible spots compared with CFE. Nine common spots from both FIGE and CFE were selected for peptide sequencing by mass spectrometry (MS), which revealed higher final ion scores of all nine protein spots from FIGE. Native protein complexes ranging from 800 kDa to larger than 2000 kDa became apparent using FIGE compared with CFE. Conclusion The present investigation suggests that FIGE under appropriate conditions improves protein separation efficiency during PAGE as a result of increased local protein concentration. FIGE can be implemented with minimal additional instrumentation in any laboratory setting. Despite the tradeoff of longer running times, FIGE can be a powerful protein separation tool. PMID:17897441

  11. An Experimental Study of the In-Situ Gelation of Chromium(+ 3)\\/Polyacrylamide Polymer in Porous Media

    Microsoft Academic Search

    Chyi-Gang Huang; Don Green; Paul Willhite

    1986-01-01

    Gelled polymers are being used increasingly as reservoir flow control agents to improve the water-to-oil ratio (WOR) in waterflooding. To date, little has been published in the literature on the in-situ gelation of polymers in porous media. This work was undertaken to study the process of in-situ gelation of a gel system consisting of a polyacrylamide polymer, sodium dichromate, and

  12. An experimental study of the in-situ gelation of chromium(+3)-polyacrylamide polymer in porous media

    Microsoft Academic Search

    C. G. Huang; D. W. Green; G. P. Wilhite

    1984-01-01

    Gelled polymers are being used increasingly as reservoir flow control agents to improve the water-to-oil ratio in waterflooding. To date, little has been published in the open literature on the insitu gelation of polymers in porous media. This work was undertaken to study the process of in-situ gelation of a gel system consisting of a polyacrylamide polymer, sodium dichromate and

  13. [A new method for the preparation of linear polyacrylamide gradients (author's transl)].

    PubMed

    Lorentz, K; Flatter, B

    1977-03-01

    Continuous linear gradients improve electrophoretic separations in polyacrylamide. They are obtained by overlayering equal volumes of two monomer solutions with different acrylamide concentrations, namely 180-260 and 23-50 g/l, in the usual gel tubes. The tubes are tilted 3-10 degrees to the horizontal, and rotated around their longitudinal axis until the parts of both solutions in contact are mixed homogeneously. Subsequent polymerization takes place in the vertical position. The more concentrated lower solution contains 4-nitrophenol, so that the final polymer concentration at any point of the gel can be measured densitometrically. The construction and handling of the rotation device are simple and yield highly reproducible results. This versatile method was evaluated for the separation of proteins, lipoproteins, and enzymes in human serum and yields 27-30 protein fractions by additional use of a pH-gradient. PMID:870609

  14. Effect of ?-carrageenan on volume phase transition for polyacrylamide (PAAm) hydrogel using the fluorescence technique

    NASA Astrophysics Data System (ADS)

    Akta?, Demet Kaya

    2014-03-01

    Steady-state fluorescence (SSF) technique was employed for studying swelling of polyacrylamide (PAAm) gels with various content of ?-carrageenan ( ?C). Disc shaped composite hydrogels were prepared by free-radical crosslinking copolymerization of acrylamide (AAm) with various amounts ?C. N, N'-methylenebis (acrylamide) (BIS) and ammonium persulfate (APS) were used as crosslinker and initiator, respectively. Pyranine was introduced as a fluorescence probe. Fluorescence intensity of pyranine was monitored during in situ swelling processes of composite gels. It was observed that fluorescence intensity values decreased as swelling is proceeded. Li-Tanaka equation was used to determine the swelling time constants, ? and cooperative diffusion coefficients, D from intensity variations during the swelling processes. It was shown that swelling time constants, ? decreased and diffusion coefficients, D increased as the ?C content in the composites are increased.

  15. Improvement of electrophoretic transfer by casting acrylamide gels on a cellophane sheet.

    PubMed

    Abbal, M; Julie, C

    1988-12-01

    Electrophoretic transfer of protein after isolectric focusing using a polyacrylamide gel of less than 0.5 mm is difficult if the gel is backed to an electrically nonconductive casting support, such as glass plate or plastic films. By casting the gel on a cellophane sheet, it is not necessary to remove the gel from the support prior to electrophoretic transfer. The use of a cellophane support does not alter the quality of the final pattern. PMID:3243240

  16. Photoswitchable gel assembly based on molecular recognition

    PubMed Central

    Yamaguchi, Hiroyasu; Kobayashi, Yuichiro; Kobayashi, Ryosuke; Takashima, Yoshinori; Hashidzume, Akihito; Harada, Akira

    2012-01-01

    The formation of effective and precise linkages in bottom-up or top-down processes is important for the development of self-assembled materials. Self-assembly through molecular recognition events is a powerful tool for producing functionalized materials. Photoresponsive molecular recognition systems can permit the creation of photoregulated self-assembled macroscopic objects. Here we demonstrate that macroscopic gel assembly can be highly regulated through photoisomerization of an azobenzene moiety that interacts differently with two host molecules. A photoregulated gel assembly system is developed using polyacrylamide-based hydrogels functionalized with azobenzene (guest) or cyclodextrin (host) moieties. Reversible adhesion and dissociation of the host gel from the guest gel may be controlled by photoirradiation. The differential affinities of ?-cyclodextrin or ?-cyclodextrin for the trans-azobenzene and cis-azobenzene are employed in the construction of a photoswitchable gel assembly system. PMID:22215078

  17. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  18. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  19. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  20. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  1. 21 CFR 872.3420 - Carboxymethylcellulose sodium and cationic polyacrylamide polymer denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...cationic polyacrylamide polymer denture adhesive. 872.3420 Section 872.3420...cationic polyacrylamide polymer denture adhesive. (a) Identification. A carboxymethylcellulose...cationic polyacrylamide polymer denture adhesive is a device composed of...

  2. Renewable enzyme reactors based on beds of artificial gel antibodies

    Microsoft Academic Search

    Maria Hjertén; Melinda Rezeli; Ferenc Kilár; Stellan Hjertén

    2008-01-01

    A novel approach is described for the synthesis of beds for enzyme reactors. The method is based on the use of artificial antibodies in the form of polyacrylamide gel particles with diameters around 0.1–0.3 mm. These gel particles mimic protein antibodies, raised in experimental animals, in the sense that they selectively recognize and adsorb only the protein present during the preparation

  3. The effect of temperature on gelation time for polyacrylamide/chromium (III) systems

    SciTech Connect

    Jordan, D.S.; Green, D.W.; Terry, R.E.; Willhite, G.P.

    1982-08-01

    Gelled polymers are being applied to modify the movement of injected fluids in the vicinity of injection and production wells in secondary and enhanced oil-recovery projects. One approach to gelation is to form a bulk gel in situ by injecting a slug of a polyacrylamide polymer solution containing chromium(VI) followed by a polymer slug containing a reducing agent such as sodium bisulfite. Upon mixing, CR(VI) is reduced to Cr(III), and in the subsequent reaction a gel is formed. The gelation time controls the volume of fluid that can be injected in the treatment and thus is an important variable in the process. Gelation time is known to be a function of the concentration of the reactants (chromium ion, reducing agent, and polymer) as well as the polymer type, and some data relating these variables to gelation time have been reported. Another variable affecting the reaction rate is temperature, but no data relating gelation time and temperature have been published. The purposes of the work described in this paper were to obtain experimental data on the effect of temperature on gelation time for typical polyacrylamide/Cr(III) gel systems over the range of temperatures commonly encountered in reservoirs and to develop a method of correlating the data. Gelation times were measured for five different polymers, including polymers with various degrees of hydrolysis and polymers with nonionic, anionic, and cationic character. The temperature range was 25 to 80/sup 0/C. Polymer, metal ion, and redox system concentrations and salinity also were varied. It was determined that, for a given polymer-reducing agent system at a specified concentration, the gelation time decreases as temperature is increased. The data were correlated in a manner analogous to the Arrhenius method of correlating chemical reaction rate data.

  4. Native Words, Native Warriors

    NSDL National Science Digital Library

    Throughout World War I and World War II, American Indians were asked to join the United States armed forces. They served in many different campaigns, and in many different capacities, but perhaps one of the best known groups of American Indians were the "Code Talkers". The "Code Talkers" were asked to develop a way of transmitting secret messages using their own native languages, and they were tremendously successful. This beautifully designed and multi-layered site developed by the National Museum of the American Indian presents the voices of the "Code Talkers", along with other voices, all of which are combined seamlessly with historic images, graphics, and songs. Visitors will learn about the "Code Talkers" experiences in the military, their reintegration into society upon their return from war, and subsequent recognition by both the French and United States governments.

  5. Two-dimensional gel electrophoresis method for investigation of human plasma proteins: detection of subtle changes during filtration leukapheresis.

    PubMed

    Lonberg-Holm, K; Bagley, E A; Nusbacher, J; Heal, J M

    1982-04-01

    Special problems are associated with analysis of human plasma proteins by standard "high-resolution" two-dimensional gel electrophoresis methods in which isoelectric focusing is followed by electrophoresis in sodium dodecyl sulfate/polyacrylamide gels (SDS-PAGE). Individual plasma proteins are often separated into overlapping groups of multiple spots, and identification of individual spots is further confounded by genetic variation. Analytical recovery of components of high molecular mass is also low or variable. These problems may be reduced or overcome by use of a "low-resolution" method consisting of electrophoresis of native proteins at pH 8.6 in an agarose gel followed by SDS-PAGE without added reducing agent. About 60 proteins can be resolved, most as single spots. About 25 of these proteins have been "mapped," and tentatively identified. We have examined 119 plasma samples taken from six donors who were undergoing filtration leukapheresis and 10 donors who were undergoing centrifugation leukapheresis or plateletpheresis. In all cases, passage of blood through a nylon filter induced a significant increase in a doublet of spots tentatively identified as complement component C3c. This was detected in the effluent from the filter throughout the first 30 min of filtration, and to a lesser extent in the venous blood. These spots were not induced by the centrifugation procedures. One filtration donor also showed increased acute-phase proteins 24 h after the procedure. PMID:7074886

  6. Effect of cationic polyacrylamide on the processing and properties of nanocellulose films.

    PubMed

    Raj, Praveena; Varanasi, Swambabu; Batchelor, Warren; Garnier, Gil

    2015-06-01

    The use of high molecular weight cationic polyacrylamide (CPAM) was investigated to accelerate the drainage of nanocellulose (Microfibrillated Cellulose) suspensions into films. The mechanism was quantified and optimized by measuring the gel point, the lowest solids concentration at which a continuous network is formed. The flocculation of MFC was analysed as a function of the polyelectrolyte dosage, charge density and molecular weight as well as process parameters (drainage time) and material properties. The adsorption isotherms of CPAMs on nanocellulose and their zeta potential curves were also analysed as a function of CPAM charge and dosage. Measured CPAM adsorption capacities for the 50% and 10% charged 13MDa CPAM onto MFC were 5mg/g and 8mg/g, respectively, corresponding to adsorption coverage on cellulose of 0.14mg/m(2) and 0.22mg/m(2). The floc strength and drainability of MFC suspensions were quantified with the gel point as a function of CPAM properties. For all combinations of polyelectrolyte molecular weight and charge density, the gel point of a nanocellulose suspension goes through a minimum with increasing polymer dosage. The minimum gel point was independent of the polyelectrolyte charge density at constant molecular weight. However, it reduced with decreasing CPAM molecular weight, at a constant addition rate. The drainage time of a nanocellulose suspension into a film is reduced by 2/3 by halving the gel point from 0.2 to 0.1kg/m(3); this is due to the more flocculated suspension facilitating drainage between flocs. Nanocellulose films of increased porosity also result from reducing the gel point, signifying that the more open 3D structure of the flocculated cellulose suspension is retained upon drying the 2D film cellulose film structure. PMID:25702868

  7. Transfer of Proteins from Gels to Diazobenzyloxymethyl-Paper and Detection with Antisera: A Method for Studying Antibody Specificity and Antigen Structure

    Microsoft Academic Search

    Jaime Renart; Jakob Reiser; George R. Stark

    1979-01-01

    We describe a rapid and very sensitive method for detecting proteins as antigens after their separation in polyacrylamide\\/agarose composite gels, with or without sodium dodecyl sulfate. The polyacrylamide matrix is crosslinked with a reagent that can be cleaved with periodate or alkali to facilitate transfer of the protein bands to diazobenzyloxymethyl-paper, where they are coupled covalently. Specific proteins are detected

  8. Gel placement in fractured systems

    SciTech Connect

    Seright, R.S. [New Mexico Petroleum Recovery Research Center, Socorro, NM (United States)

    1995-11-01

    This paper examines several factors that can have an important effect on gel placement in fractured systems, including gelant viscosity, degree of gelation, and gravity. For an effective gel treatment, the conductivity of the fracture must be reduced and a viable flow path must remain open between the wellbore and mobile oil in the reservoir. During placement, the gelant that``leaks off`` from the fracture into the rock plays an important role in determining how well a gel treatment will reduce channeling. For a given volume of gelant injected the distance of gelant leakoff is greater for a viscous gelant than for a low-viscosity gelant. In one method to minimize gelant leakoff, sufficient gelation is designed to occur before the gelant leaves the wellbore. The authors investigated this approach in numerous experiments with both fractured and unfractured cores. They studied Cr(III)/acetate/hydrolyzed polyacrylamide (HPAM), resorcinol/formaldehyde, Cr(III)/xanthan, aluminum/citrate/HPAM, and other gelants and gels with various delay times between gelant preparation and injection. Their results suggest both hope and caution concerning the injection of gels into fractured systems.

  9. The nanoporous morphology of photopolymerized crosslinked polyacrylamide hydrogels 

    E-print Network

    Wang, Jian

    2009-05-15

    and distribution are chosen. The pore size derived from TEM, rheology, DSC is compared and their values are self-consistent. These techniques help us understand how the nanoporous morphology of crosslinked polyacrylamide hydrogels is influenced by their chemical...

  10. In situ grouting of buried transuranic waste with polyacrylamide

    SciTech Connect

    Spalding, B.P.; Lee, S.Y.; Farmer, C.D.; Hyder, L.K.; Supaokit, P.

    1987-01-01

    This project is a demonstration and evaluation of the in situ hydrologic stabilization of buried transuranic waste at a humid site via grout injection. Two small trenches, containing buried transuranic waste, were filled with 34.000 L of polyacrylamide grout. Initial field results have indicated that voids within the trenches were totally filled by the grout and that the intratrench hydraulic conductivity was reduced to below field-measurable values. No evidence of grout constituents were observed in twelve perimeter groundwater monitoring wells indicating that grout was contained completely within the two trenches. Polyacrylamide grout was selected for field demonstration over the polyacrylate grout due to its superior performance in laboratory degradation studies. Also supporting the selection of polyacrylamide was the difficulty in controlling the set time of the acrylate polymerization. Based on preliminary degradation monitoring, the polyacrylamide was estimated to have a microbiological half-life of 362 years in the test soil. 15 refs., 9 figs., 12 tabs.

  11. Effect of gypsum and polyacrylamides on water turbidity and infiltration in a sodic soil

    Microsoft Academic Search

    S. Sivapalan

    2005-01-01

    Water ponded on sodic soils can develop turbidity problems which seriously affect rice crop establishment. A total of 19 polyacrylamide products were assessed for their effectiveness to control water turbidity in a sodic soil under laboratory conditions. Anionic polyacrylamides were more effective than cationic or non- ionic polyacrylamides. When combined with gypsum, polyacrylamides were found to be more effective than

  12. Silk fibroin/polyacrylamide semi-interpenetrating network hydrogels for controlled drug release.

    PubMed

    Mandal, Biman B; Kapoor, Sonia; Kundu, Subhas C

    2009-05-01

    The present study describes a semi-interpenetrating network hydrogel fabricated using silk fibroin/polyacrylamide for controlled drug delivery applications. Hydrogels were synthesized using varied ratios of silk fibroin/acrylamide mixtures crosslinked by N,N'-Methylenebisacrylamide. Fourier-Transform Infrared analysis was performed suggesting beta sheet transition of silk fibroin with hydrogels. Scanning electron microscopy revealed microporous surface with maximum pore size of 50+/-11 microm. Rheological properties along with swellability, degradation, sol fraction estimation, equilibrium water content and swelling kinetics were evaluated. Compressive strength of 241.9+/-5.5 kPa was observed suggesting mechanically stronger gels. MTT assay showed biocompatibility and absence of deleterious effects of hydrogel on cell viability and functionality. In vitro release studies using two model compounds i.e. trypan blue dye and FITC-inulin reveal their sustained release from the fabricated hydrogel constructs. PMID:19203791

  13. Site blocking effects on adsorbed polyacrylamide conformation

    NASA Astrophysics Data System (ADS)

    Brotherson, Brett A.

    The use of polymers as flocculating additives is a common practice in many manufacturing environments. However, exactly how these polymers interact with surfaces is relatively unknown. One specific topic which is thought to be very important to flocculation is an adsorbed polymer's conformation. Substantial amounts of previous work, mainly using simulations, have been performed to elucidate the theory surrounding adsorbed polymer conformations. Yet, there is little experimental work which directly verifies current theory. In order to optimize the use of polymer flocculants in industrial applications, a better understanding of an adsorbed polymer's conformation on a surface beyond theoretical simulations is necessary. This work looks specifically at site blocking, which has a broad impact on flocculation, adsorption, and surface modification, and investigated its effects on the resulting adsorbed polymer conformation. Experimental methods which would allow direct determination of adsorbed polymer conformational details and be comparable with previous experimental results were first determined or developed. Characterization of an adsorbed polymer's conformation was then evaluated using dynamic light scattering, a currently accepted experimental technique to examine this. This commonly used technique was performed to allow the comparison of this works results with past literature. Next, a new technique using atomic force microscopy was developed, building on previous experimental techniques, to allow the direct determination of an adsorbed polymer's loop lengths. This method also was able to quantify changes in the length of adsorbed polymer tails. Finally, mesoscopic simulation was attempted using dissipative particle dynamics. In order to determine more information about an adsorbed polymer's conformation, three different environmental factors were analyzed: an adsorbed polymer on a surface in water, an adsorbed polymer on a surface in aqueous solutions of varying ionic strength, and an adsorbed polymer on a surface functionalized with site blocking additives. This work investigated these scenarios using a low charge density high molecular weight cationic polyacrylamide. Three different substrates, for polymer adsorption were analyzed: mica, anionic latex, and glass. It was determined that, similar to previous studies, the adsorbed polymer layer thickness in water is relatively small even for high molecular weight polymers, on the order of tens of nanometers. The loop length distribution of a single polymer, experimentally verified for the first time, revealed a broad span of loop lengths as high as 1.5 microns. However, the bulk of the distribution was found between 40 and 260 nanometers. For the first time, previous theoretical predictions regarding the salt effect on adsorbed polymer conformation were confirmed experimentally. It was determined that the adsorbed polymer layer thickness expanded with increasing ionic strength of the solvent. Using atomic force microscopy, it was determined that the adsorbed polymer loop lengths and tail lengths increased with increasing ionic strength, supporting the results found using dynamic light scattering. The effect of the addition of site blocking additives on a single polymer's conformation was investigated for the first time. It was determined that the addition of site blocking additives caused strikingly similar results as the addition of salt to the medium. The changes in adsorbed polymer's loop lengths was found to be inconsistent and minimal. However, the changes in an adsorbed polymer's free tail length was found to increase with increasing site blocking additive levels. These results were obtained using either PDADMAC or cationic nanosilica as site blocking additives.

  14. Hydrophobically Modified Sulfonated Polyacrylamides for IOR: Correlations between

    E-print Network

    Paris-Sud XI, Université de

    Water Soluble Polymer Symbols C Polymer concentration (g/L) C* Coil overlap concentration (g/L) (for non-associative polymers) C Viscosity upturn concentration (g/L) (for associative polymers) dh Hydrodynamic diameter (µmHydrophobically Modified Sulfonated Polyacrylamides for IOR: Correlations between Associative

  15. Polyacrylamide molecular weight effects on soil infiltration and erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of smectitic soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  16. Organic matter and polyacrylamide amendment of Norfolk loamy sand

    Microsoft Academic Search

    W. J. Busscher; J. M. Novak; T. C. Caesar-TonThat

    2007-01-01

    Loamy sand soils of the southeastern USA Coastal Plains often have poor physical properties because they contain cemented subsurface hard layers that restrict root development and yield. Their physical properties can be improved by adding amendments. Polyacrylamide (PAM) amendments and\\/or organic matter (OM) in the form of ground wheat (Triticum aestivum L.) stubble or pecan (Carya illinoensis) branches were mixed

  17. Compressive and shear properties of flocculated kaolinite–polyacrylamide suspensions

    Microsoft Academic Search

    M. S. Nasser; A. E. James

    2008-01-01

    The influence of cationic and anionic polyacrylamides (PAM) on the compressive and shear properties of kaolinite suspensions has been investigated at pH 7. The compressive properties show cationic PAM based suspensions to be less compressible than the anionic PAM based suspensions. On the other hand, rheological measurements show that the kaolinite–PAM system is thixotropic with a measurable yield stress. A

  18. HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modified starch-based polymers can be engineered for specific properties by combining starch with synthetic polymers through graft copolymerization. Polyacrylamide grafted starches have received a great deal of applications in areas such as superabsorbent paper-making additives, drag reduction and ...

  19. Flow Birefringence of Aqueous Polyacrylamide Solutions Auralee Morin, Dan Lathrop

    E-print Network

    Anlage, Steven

    Flow Birefringence of Aqueous Polyacrylamide Solutions Auralee Morin, Dan Lathrop 1. Basic when top slide holder partially submerged No previous birefringence studies of aqueous PAAm solutions. Furthermore, many of the general oscillatory flow birefringence studies in the literature detect the effect

  20. PREPARATION OF STARCH-GRAFT-POLYACRYLAMIDE COPOLYMERS BY REACTIVE EXTRUSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide (PAAm) were prepared by reactive extrusion using a co-rotating twin screw extruder and ammonium persulfate initiator. Feed rates were 109 g/min to 325 g/min (all components) at a moisture content of 50%, with screw speeds in the range 100 rpm to 300 rpm...

  1. PREPARATION OF STARCH-G-POLYACRYLAMIDE COPOLYMERS BY REACTIVE EXTRUSION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch and polyacrylamide were prepared by reactive extrusion using a co-rotating twin screw extruder and ammonium persulfate initiator. Feed rates were 109 g/min up to 325 g/min (all components) at a moisture content of 50 percent, with screw speeds in the range 100 rpm to 300 ...

  2. The impact of polyacrylamide flocculant solution age on flocculation performance

    Microsoft Academic Search

    A. T Owen; P. D Fawell; J. D Swift; J. B Farrow

    2002-01-01

    Aqueous solutions of high molecular weight polyacrylamides used to flocculate mineral slurries undergo time-based changes in their properties. Previous studies of the impact of ageing on flocculation performance have focused on time-scales of weeks or months, which has little relevance to industrial practice. In this study, ageing times from 1 h to 6 days were examined. Flocculation was achieved continuously

  3. Acrylamide monomer leaching from polyacrylamide-treated irrigation furrows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-soluble polyacrylamide (WSPAM), used to reduce erosion in furrow irrigated fields and other agriculture applications, contain less than 0.05% Acrylamide monomer (AMD). The AMD, a potent neurotoxicant and suspected carcinogen, is readily dissolved and transported in flowing water. Deep percol...

  4. Sequencing of N-Linked Oligosaccharides Directly from Protein Gels: In-Gel Deglycosylation Followed by Matrix-Assisted Laser Desorption\\/Ionization Mass Spectrometry and Normal-Phase High-Performance Liquid Chromatography

    Microsoft Academic Search

    Bernhard Küster; Susan F. Wheeler; Ann P. Hunter; Raymond A. Dwek; David J. Harvey

    1997-01-01

    A generally applicable, rapid, and sensitive method for profiling and sequencing of glycoprotein-associated N-linked oligosaccharides from protein gels was developed. The method employed sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) for protein separation and purification and in-gel deglycosylation using PNGase F for glycan release. Profiles of the neutral glycans from bovine ribonuclease B, chicken ovalbumin, and human immunoglobulin G (IgG), as

  5. An experimental study of the in-situ gelation of chromium(+3)/polyacrylamide polymer in porous media

    SciTech Connect

    Huang, C.G.; Green, D.W.; Willhite, G.P.

    1986-11-01

    Gelled polymers are being used increasingly as reservoir flow control agents to improve the water-to-oil ratio (WOR) in waterflooding. To date, little has been published in the literature on the in-situ gelation of polymers in porous media. This work was undertaken to study the process of in-situ gelation of a gel system consisting of a polyacrylamide polymer, sodium dichromate, and thiourea. The experiments consisted of continuous injection of gel solutions into 1-ft (0.3-m) unconsolidated sandpacks. Pressure distributions along the flow direction were used to interpret the nature of gelation in the porous media. The authors found the gelation occurred much earlier than anticipated from beaker tests where gel solutions were under conditions of no shear-e.g., a gel solution with a nominal 10-day gel time in a beaker gelled in 85 hours in a porous-medium run. Shear was considered one of the major factors affecting the in-situ shear rate, and we determined that gelation times decreased with increasing in-situ shear rates. Under the same in-situ shear rate, the in-situ gelation times were approximately equal in sandpacks prepared from different grain sizes. The order in which in-situ gelation occurred along the flow direction indicated that the shear history affected gelation time. Effluents from displacements with gel solutions were analyzed to evaluate the change in the properties of a gel solution as it moved through the porous media. The chemical analysis indicated that the retention of polymer was marked after the in-situ gelation developed.

  6. An experimental study of the in-situ gelation of chromium(+3)-polyacrylamide polymer in porous media

    SciTech Connect

    Huang, C.G.; Green, D.W.; Wilhite, G.P.

    1984-04-01

    Gelled polymers are being used increasingly as reservoir flow control agents to improve the water-to-oil ratio in waterflooding. To date, little has been published in the open literature on the insitu gelation of polymers in porous media. This work was undertaken to study the process of in-situ gelation of a gel system consisting of a polyacrylamide polymer, sodium dichromate and thiourea. The experiments consisted of continously injecting gel solutions into one-foot unconsolidated sandpacks. Pressure distributions along the flow direction were used to interpret the nature of gelation in the porous media. It was found that gelation in porous media occured much earlier than anticipated from beaker tests where gel solutions were under conditions of no shear. For example, a gel solution with a nominal 10-day gel time in a beaker gelled in 85 hours in a porous medium run. Shear was thought to be one of the major factors affecting the in-situ gelation rate and it was determined that gelation times decreased with increasing insitu shear rates. Under the same in-situ shear rate, the in-situ gelation times were approximately equal in sandpacks prepared from different grain sizes. The order in which in-situ gelation occurred along the flow direction indicated that the shear history had an effect on gelation time. Effluents from displacements with gel solutions were analyzed to evaluate the change in the properties of a gel solution as it moved through the porous media. The chemical analysis indicated that the retention of polymer was marked after the in-situ gelation developed.

  7. Comparative studies on the analysis of glycoproteins and lipopolysaccharides by the gel-based microchip and SDS-PAGE

    Microsoft Academic Search

    Jung-Feng Hsieh; Shui-Tein Chen

    2007-01-01

    In order to determine time efficiency between the gel-based microchip (LabChip) and traditional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), glycoproteins and lipopolysaccharides were analyzed in this study. After 90 min of gel electrophoresis, glycoproteins (bovine serum albumin, lysozyme, ovalbumin, and apo-transferrin) and fluorescent lipopolysaccharides (LPS-O and LPS-S) under reducing conditions could be analyzed by SDS-PAGE, and it would take (including

  8. Immunochemical studies of Aspergillus fumigatus mycelial antigens by polyacrylamide gel electrophoresis and Western blotting techniques

    Microsoft Academic Search

    VERONICA M. HEARN; ELAINE V. WILSON; J.-P. Latge; D. W. R. Mackenzie

    1990-01-01

    Differences were detectable among strains of the opportunist fungal pathogen Aspergillus fumgatus when water- soluble (WS) preparations were analysed by combined SDS-PAGE and Western blotting procedures. A wide range of molecules of apparent molecular masses from approximately 20 to > lo0 kDa showed specific binding to antibodies raised in rabbits to A. fumgatus wall and cytoplasmic components. The ability to

  9. High-Resolution Polyacrylamide Gel Electrophoresis of Carbohydrates Derivatized with a Visible Dye

    Microsoft Academic Search

    D. A. Westfall; R. R. Flores; G. R. Negrete; A. O. Martinez; L. S. Haro

    1998-01-01

    A technique for carbohydrate analysis that is both inexpensive and easily performed is currently unavailable. In this communication we address the problem and have outlined a method for labeling saccharides with a visible dye, 4-amino-1,1?-azobenzene-3,4?-disulfonic acid, which has an absorption maximum of 489 nm and an extinction coefficient of 37,615, to facilitate visible detection at low levels. The visible dye

  10. A Novel Method to Detect ?-Cyclodextrin Glucosyl Transferase (?-CGTase) Activity on Polyacrylamide Gels

    Microsoft Academic Search

    Saeed-Reza Pakzad; Soheila Ajdary; Nasrin Moazami; Saeed Haghighi

    2005-01-01

    ?-cyclodextrin glucosyl transferase (?-CGTase) hydrolyses starch to produce ?-cyclodextrin by transglycosylation (cyclization) activity. The conventional method for detection of ?-CGTase activity is based on detecting starch hydrolysis by iodine staining. This method reveals all amylolytic enzymes, but can not discriminate them. In the present study, we introduce a new method for specific detection of ?-CGTase activity and its specific product

  11. In vitro immunization with antigen directly blotted from SDS-polyacrylamide gels to polyvinylidene difluoride membranes.

    PubMed

    Guzman, J; Schoedon, G; Blau, N

    1993-01-14

    A new immunization method has been developed for the production of monoclonal antibodies. This technique uses small amounts of partially purified and weak immunogenic antigen, bound to membranes after blotting from SDS-PAGE. For this purpose two different membranes have been tested. Immobilon-P polyvinylidene difluoride (PVDF) membranes were less mitogenic than nitrocellulose membranes, and were therefore selected for the in vitro immunization using 6-pyruvoyl tetrahydropterin synthase as antigen. The in vitro immunization method was then used for the production of monoclonal antibodies against 6-pyruvoyl tetrahydropterin synthase, one of the key enzymes on the biosynthetic pathway of tetrahydrobiopterin, the natural cofactor of the mammalian aromatic amino acid hydroxylases. The antibodies obtained were mainly of the IgM type. PMID:8429215

  12. Reprogramming cellular phenotype by soft collagen gels.

    PubMed

    Ali, M Yakut; Chuang, Chih-Yuan; Saif, M Taher A

    2014-11-28

    A variety of cell types exhibit phenotype changes in response to the mechanical stiffness of the substrate. Many cells excluding neurons display an increase in the spread area, actin stress fiber formation and larger focal adhesion complexes as substrate stiffness increases in a sparsely populated culture. Cell proliferation is also known to directly correlate with these phenotype changes/changes in substrate stiffness. Augmented spreading and proliferation on stiffer substrates require nuclear transcriptional regulator YAP (Yes associated protein) localization in the cell nucleus and is tightly coupled to larger traction force generation. In this study, we show that different types of fibroblasts can exhibit spread morphology, well defined actin stress fibers, and larger focal adhesions even on very soft collagen gels (modulus in hundreds of Pascals) as if they are on hard glass substrates (modulus in GPa, several orders of magnitude higher). Strikingly, we show, for the first time, that augmented spreading and other hard substrate cytoskeleton architectures on soft collagen gels are not correlated with the cell proliferation pattern and do not require YAP localization in the cell nucleus. Finally, we examine the response of human colon carcinoma (HCT-8) cells on soft collagen gels. Recent studies show that human colon carcinoma (HCT-8) cells form multicellular clusters by 2-3 days when cultured on soft polyacrylamide (PA) gels with a wide range of stiffness (0.5-50 kPa) and coated with an extracellular matrix, ECM (collagen monomer/fibronectin). These clusters show limited spreading/wetting on PA gels, form 3D structures at the edges, and eventually display a remarkable, dissociative metastasis like phenotype (MLP), i.e., epithelial to rounded morphological transition after a week of culture on PA gels only, but not on collagen monomer coated stiff polystyrene/glass where they exhibit enhanced wetting and form confluent monolayers. Here, we show that HCT-8 cell clusters also show augmented spreading/wetting on soft collagen gels and eventually form confluent monolayers as on rigid glass substrates and MLP is completely inhibited on soft collagen gels. Overall, these results suggest that cell-material interactions (soft collagen gels in this case) can induce cellular phenotype and cytoskeleton organization in a remarkably distinct manner compared to a classical synthetic polyacrylamide (PA) hydrogel cell culture model and may contribute in designing new functional biomaterials. PMID:25284029

  13. Ultrasensitive Fluorescence-Based Detection of Nascent Proteins in Gels

    Microsoft Academic Search

    Sadanand Gite; Sergey Mamaev; Jerzy Olejnik; Kenneth Rothschild

    2000-01-01

    The most common method of analysis of proteins synthesized in a cell-free translation system (e.g., nascent proteins) involves the use of radioactive amino acids such as [35S]methionine or [14C]leucine. We report a sensitive, nonisotopic, fluorescence-based method for the detection of nascent proteins directly in polyacrylamide gels. A fluorescent reporter group is incorporated at the N-terminus of nascent proteins using an

  14. Intra-Articular Polyacrylamide Hydrogel Injections Are Not Innocent

    PubMed Central

    Tonbul, Murat; Adas, Mujdat; Bekmezci, Taner; Kara, Ahmet Duran

    2014-01-01

    Osteoarthritis is a chronic disorder characterized by joint cartilage degeneration with concomitant changes in the synovium and subchondral bone metabolism. Many conservative treatment modalities, one of which is intra-articular injections, have been described for the treatment of this disorder. Traditionally, hyaluranic acid and corticosteroids are the agents that have been used for this purpose. Recently, polyacrylamide hydrogels are being used widely. Biocompatibility, nonbioabsorbability, and anti-infectious effect obtained by silver addition made polyacrylamide hydrogels more popular. In this paper, we present a case and the method of our management, in whom host tissue reaction (foreign body granuloma, edema, inflammation, and redness induration) has been observed, as the first and unique adverse effect reported in the literature. PMID:25197596

  15. Sample preparation by SDS\\/PAGE and in-gel digestion

    Microsoft Academic Search

    Ulf Hellman

    \\u000a A convenient method for the isolation of samples for microsequencing or mass spectrometry utilizing polyacrylamide gel electrophoresis\\u000a is described in detail, including prerequisites for a successful outcome. Briefly, after visualization by e.g. Coomassie or\\u000a silver, internal peptides are generated by in-gel proteolytic digestion, and after extraction, the corresponding protein is\\u000a analyzed, i.e. the protein is identified by search in sequence

  16. Denaturing gradient gel electrophoresis (DGGE) increases resolution and informativity of Alu -directed inter-repeat PCR

    Microsoft Academic Search

    N. J. van Orsouw; D. Li; J. Vijg

    1997-01-01

    By inter-repeat PCR, multiple polymorphic loci can be targeted in parallel. To improve resolution and extend the number of detectable polymorphisms,Alu-directed inter-repeat PCR products from two large pedigrees of the Centre d»Etude du Polymorphisme Humain (CEPH) were electrophoretically resolved in non-denaturing polyacrylamide gels and, separately, on the basis of sequence content by denaturing gradient gel electrophoresis (DGGE). The resolution in

  17. Detection of peptide nucleic acids in tissue extracts of treated animals by gel mobility shift assay

    Microsoft Academic Search

    Karen Jansen; Elliott Richelson

    2000-01-01

    We have developed a sensitive and reproducible gel mobility shift assay to detect PNA oligomers in tissue of treated animals. PNA present in purified tissue extracts of treated animals is hybridized to a 33P-labelled DNA oligomer probe, and analyzed by polyacrylamide gel electrophoresis. The PNA–DNA hybrid migrates more slowly than the DNA probe alone and can be quantified relative to

  18. Turning a PAGE: the overnight sensation of SDS-polycrylamide gel electrophoresis

    Microsoft Academic Search

    Thoru Pederson

    2007-01-01

    The zonal separation of proteins on the basis of net charge was initially conducted on paper, then in columns of sucrose and later in gels of starch and polyacrylamide, with appropriate electric fields. Then, in 1964, a graduate student at MIT discovered the power of sodium dodecyl sulfate (SDS) to dissoci- ate the envelope proteins of Escherichia coli and to

  19. Characterization of Carbohydrates Using Highly Fluorescent 2-Aminobenzoic Acid Tag Following Gel Electrophoresis of Glycoproteins

    Microsoft Academic Search

    Kalyan R. Anumula; Ping Du

    1999-01-01

    Application of the most sensitive fluorescent label 2-aminobenzoic acid (anthranilic acid, AA) for characterization of carbohydrates from the glycoproteins (?15 pmol) separated by polyacrylamide gel electrophoresis is described. AA label is used for the determination of both monosaccharide composition and oligosaccharide map. For the monosaccharide determination, bands containing the glycoprotein of interest are excised from the polyvinylidene fluoride (PVDF) membrane

  20. Gel Electrophoresis

    NSDL National Science Digital Library

    2011-08-20

    In this activity, learners simulate the process of DNA fingerprinting by using electricity to separate colored dyes. Learners use simple materials to assemble a comb (electrophoresis chamber) to hold the samples, make a 0.2% sodium bicarbonate buffer and 1% gel solution, connect a high voltage power supply, and prepare 5 different samples. Then learners test their model and observe each sample.

  1. Measurements of Elastic Moduli of Silicone Gel Substrates with a Microfluidic Device

    PubMed Central

    Gutierrez, Edgar; Groisman, Alex

    2011-01-01

    Thin layers of gels with mechanical properties mimicking animal tissues are widely used to study the rigidity sensing of adherent animal cells and to measure forces applied by cells to their substrate with traction force microscopy. The gels are usually based on polyacrylamide and their elastic modulus is measured with an atomic force microscope (AFM). Here we present a simple microfluidic device that generates high shear stresses in a laminar flow above a gel-coated substrate and apply the device to gels with elastic moduli in a range from 0.4 to 300 kPa that are all prepared by mixing two components of a transparent commercial silicone Sylgard 184. The elastic modulus is measured by tracking beads on the gel surface under a wide-field fluorescence microscope without any other specialized equipment. The measurements have small and simple to estimate errors and their results are confirmed by conventional tensile tests. A master curve is obtained relating the mixing ratios of the two components of Sylgard 184 with the resulting elastic moduli of the gels. The rigidity of the silicone gels is less susceptible to effects from drying, swelling, and aging than polyacrylamide gels and can be easily coated with fluorescent tracer particles and with molecules promoting cellular adhesion. This work can lead to broader use of silicone gels in the cell biology laboratory and to improved repeatability and accuracy of cell traction force microscopy and rigidity sensing experiments. PMID:21980487

  2. Improvement of Catalytic Efficiency, Thermo-stability and Dye Decolorization Capability of Pleurotus ostreatus IBL-02 laccase by Hydrophobic Sol Gel Entrapment

    PubMed Central

    2012-01-01

    Background In serious consideration of the worldwide environmental issues associated with the extensive use of the textile dyes and effluents generated thereof, the scientists across the world are in search for potential treatment technologies for their treatment. In such scenario the ligninolytic enzymes provide a potential alternative because they are cost effective, eco-friendly and can be applied to wide range of dye containing industrial effluents. Results Laccase produced from Pleurotus ostreatus IBL-02 during decolorization of the reactive textile dye Drimarene brilliant red K-4BL (DBR K-4BL) was purified and immobilized by hydrophobic gel entrapment. The crude laccase was 4.2-fold purified with specific activity of 573.52 U/mg after passing through the DEAE-Sepharose ion exchange and Sephadex-G-100 chromatography columns. P. ostreatus IBL-02 laccase was found to be a homogenous monomeric protein as evident by single band corresponding to 67 kDa on native and sodium dodesylsulfate polyacrylamide gel electrophoresis (PAGE). The laccase was immobilized by entrapment in Sol–gel matrix of trimethoxysilane (T) and proplytetramethoxysilane (P) prepared using different T:P molar ratios. The free and immobilized laccases were compared to investigate the effect of immobilization on catalytic efficiency and thermo-stability features. Laccase immobilized in the Sol–gel of 1:5 T:P ratio was optimally active and thermo-stable fraction at pH 5, 60°C with half-life of 3 h and 50 min. Laccases immobilized in 1:2 and 1:5 T:P ratio gels had significantly higher Km (83 and100mM) and Vmax (1000 and 1111 mM/mg) values as compared to free laccase. After 5 h reaction time varying decolorization percentages with a maximum of 100% were achieved for different dyes and effluents. Conclusions In summary, P. ostreatus IBL-02 laccase was immobilized by entrapping in a Sol–gel matrix with an objective to enhance its catalytic and stability properties. Sol–gel entrapped laccase presented potential efficiency as a biocatalyst when applied for decolorization of different dyes and effluents. The main benefits of the Sol–gel matrix immobilization processes are the eco-friendly approach, chemical free and energy saving reaction conditions. PMID:23021344

  3. Aerosol gels

    NASA Technical Reports Server (NTRS)

    Sorensen, Christopher M. (Inventor); Chakrabarti, Amitabha (Inventor); Dhaubhadel, Rajan (Inventor); Gerving, Corey (Inventor)

    2010-01-01

    An improved process for the production of ultralow density, high specific surface area gel products is provided which comprises providing, in an enclosed chamber, a mixture made up of small particles of material suspended in gas; the particles are then caused to aggregate in the chamber to form ramified fractal aggregate gels. The particles should have a radius (a) of up to about 50 nm and the aerosol should have a volume fraction (f.sub.v) of at least 10.sup.-4. In preferred practice, the mixture is created by a spark-induced explosion of a precursor material (e.g., a hydrocarbon) and oxygen within the chamber. New compositions of matter are disclosed having densities below 3.0 mg/cc.

  4. Rheology of ?-carrageenan and ?-lactoglobulin mixed gels

    Microsoft Academic Search

    M. M. Ould Eleya; S. L. Turgeon

    2000-01-01

    Gel formation and the melting of ?-carrageenan in the presence of ?-lactoglobulin were investigated using dynamic rheological techniques as well as a sequence of experimental sweeps of time–temperature, frequency, and strain. The blends, initially prepared at 45°C, show homogeneous mixtures, which then lead to the formation of a gelled ?-carrageenan network containing inclusions of native ?-lactoglobulin during the controlled cooling

  5. Multifunctional Biodegradable Polyacrylamide Nanocarriers for Cancer Theranostics - A “See and Treat” Strategy

    PubMed Central

    Wang, Shouyan; Kim, Gwangseong; Lee, Yong-Eun Koo; Hah, Hoe Jin; Ethirajan, Manivannan; Pandey, Ravindra K.; Kopelman, Raoul

    2012-01-01

    We describe here the development of multifunctional nanocarriers, based on amine functionalized biodegradable polyacrylamide nanoparticles (NPs), for cancer theranostics, including active tumor targeting, fluorescence imaging and photodynamic therapy. The structural design involves adding primary amino groups and biodegradable crosslinkers during the NP polymerization, while incorporating photodynamic and fluorescent imaging agents into the NP matrix, and conjugating PEG and tumor-targeting ligands onto the surface of the NPs. The as-synthesized NPs are spherical, with an average diameter of 44 nm. An accelerated biodegradation study, using sodium hydroxide or porcine liver esterase, indicated a hydrogel polymer matrix chain collapse within several days. By using gel permeation chromatography, small molecules were detected, after the degradation. In vitro targeting studies on human breast cancer cells indicate that the targeted NPs can be transported efficiently into tumor cells. Incubating the multifunctional nanocarriers into cancer cells enabled strong fluorescence imaging. Irradiation of the photosensitizing drug, incorporated within the NPs, with light of a suitable wavelength, causes significant but selective damage to the impregnated tumor cells, but only inside the illuminated areas. Overall, the potential of polymeric-based NPs as biodegradable, multifunctional nanocarriers, for cancer theranostics, is demonstrated here. PMID:22702416

  6. Unacceptable Results with an Accepted Soft Tissue Filler: Polyacrylamide Hydrogel

    Microsoft Academic Search

    Ali Manafi; Abol-Hasan Emami; Aydin H. Pooli; Mohammadali Habibi; Lila Saidian

    2010-01-01

    Background  Polyacrylamide hydrogel, considered a safe and biocompatible soft tissue filler, is widely used in cosmetic procedures. Its\\u000a use for facial contouring and breast augmentation in Iran has increased dramatically in recent years. Most patients and many\\u000a doctors are unaware of possible and reported adverse effects related to its administration.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  This study enrolled 98 patients experiencing unsatisfactory results and complications of

  7. Direct voltammetry and electrochemical catalysis with horseradish peroxidase in polyacrylamide hydrogel films.

    PubMed

    Huang, Rong; Hu, Naifei

    2003-05-01

    This paper reports the direct voltammetry of horseradish peroxidase (HRP) incorporated in amphiphilic polyacrylamide (PAM) films modified on pyrolytic graphite (PG) electrodes. Cyclic voltammetry of HRP-PAM films showed a pair of well-defined, nearly reversible peaks at approximately -0.33 V vs. SCE in pH 7.0 buffers, characteristic of HRP heme Fe(III)/Fe(II) redox couple. The PAM films in solution contained large amounts of water and formed a hydrogel, and provided a favorable microenvironment for HRP and facilitated its direct electron transfer with underlying PG electrodes. The apparent heterogeneous electron transfer rate constant (k(s)) and formal potential (E*') were estimated by fitting the data of square wave voltammetry (SWV) with the non-linear regression analysis. UV-vis absorption spectra demonstrated that HRP in PAM films retained its secondary structure similar to its native state. The embedded HRP in PAM films showed the electrocatalytic activity to various substrates such as nitrite, oxygen and hydrogen peroxide. The possible mechanism of catalytic reaction of H(2)O(2) with HRP-PAM films was proposed. PMID:12834838

  8. Embedded ceria nanoparticles in gel improve electrophoretic separation: a preliminary demonstration.

    PubMed

    Zarei, Mohammad; Ahmadzadeh, Hossein; Goharshadi, Elaheh K

    2015-06-15

    Slab gel electrophoresis is still the gold standard method for the separation of biomolecules such as proteins and DNA with advantages such as simplicity, affordability, and high throughput, but it suffers from inadequate separation speed and resolution. Single capillary gel electrophoresis, on the other hand, offers faster separation time and improved resolution at the expense of higher cost and loss of high throughput capability. The high surface to volume ratio of the capillary causes improved heat dissipation leading to a reduced Joule heating and a higher resolution. Here, for the first time, we show the use of dispersed ceria nanoparticles (NPs) to improve the resolution and speed of protein separation in slab gel electrophoresis. We measured the rheological parameters of separation medium in order to find a meaningful relationship between viscosity changes, Joule heating, and band broadening. The results showed that ceria NPs decrease the viscosity of polyacrylamide gel. By loading 0.03% (w/v) ceria NPs into polyacrylamide gel at 25 °C, the viscosity decreased 22% and the thermal conductivity increased to 81%, which resulted in 35% reduction in Joule heating and 47% increase in resolution. This work is a cross disciplinary of theoretical physical chemistry for thermal conductivity and rheological measurements of PA and ceria suspensions and application in slab gel electrophoresis. We report here, for the first time, that embedded NPs in PA gel could potentially interface high throughput capability of slab gel electrophoresis with high separation speed of single capillary electrophoresis. PMID:25948088

  9. Electric Field Enhanced Diffusion of Salicylic Acid through Polyacrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Niamlang, Sumonman; Sirivat, Anuvat

    2008-03-01

    The release mechanisms and the diffusion coefficients of salicylic acid -loaded polyacrylamide hydrogels were investigated experimentally by using a modified Franz-diffusion cell at 37 ^oC to determine the effects of crosslinking ratio and electric field strength. A significant amount of salicylic acid is released within 48 hours from the hydrogels of various crosslinking ratios, with and without electric field. The release characteristic follows the Q vs. t^1/2 linear relationship. Diffusion coefficient initially increases with increasing electric field strength and reaches the maximum value at electric field strength of 0.1 V; beyond that it decreases with electric field strength and becomes saturated at electric field strength of 5 V. The diffusion coefficient increases at low electric field strength (less 0.1 V) as a result of the electrophoresis of the salicylic acid, the expansion of pore size, and the induced pathway in pigskin. For electric field strength higher than 0.1 V, the decrease in the diffusion coefficient is due to the reduction of the polyacrylamide pore size. The diffusion coefficient obeys the scaling behavior D/Do=(drug size/pore size)^m, with the scaling exponent m equal to 0.93 and 0.42 at electric fields of 0 and 0.1 V, respectively.

  10. Separation of DNA restriction fragments by high performance capillary electrophoresis with low and zero crosslinked polyacrylamide using continuous and pulsed electric fields.

    PubMed

    Heiger, D N; Cohen, A S; Karger, B L

    1990-09-01

    This paper presents results on the separation of DNA restriction fragments by high performance capillary electrophoresis (HPCE). Capillaries containing polyacrylamide with low amounts of crosslinking agent (i.e. 0.5% C) were first studied. The greater molecular accessibility offered with columns of low crosslinking, relative to higher crosslinked gels (e.g. 5% C), permitted high efficiency separations of double stranded DNA fragments up to 12,000 base pairs in length. Capillaries containing no crosslinking agent, i.e. linear polyacrylamide, were then examined. Ferguson plots (i.e. log mobility vs. %T) were used to assess the size selectivity of linear polyacrylamide capillaries. In another study, it was determined that the relative migration of DNA species was a strong function of applied electric field and molecular size. Lower fields yielded better resolution than higher fields for DNA molecules larger than about 1000 base pairs, albeit at the expense of longer separation time. Based on these results, we have examined pulsed field HPCE and have demonstrated the use of this approach to enhance separation. PMID:1962784

  11. New findings for in-gel digestion accelerated by high-intensity focused ultrasound for protein identification by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

    Microsoft Academic Search

    R. J. Carreira; F. M. Cordeiro; A. J. Moro; M. G. Rivas; R. Rial-Otero; E. M. Gaspar; I. Moura; J. L. Capelo

    2007-01-01

    New findings in sample treatment based on high-intensity focused ultrasound (HIFU) for protein digestion after polyacrylamide gel electrophoresis separation are presented. The following variables were studied: (i) sample volume; (ii) sonotrode diameter; (iii) previous protein denaturation; (iv) cooling; (v) enzyme concentration; and (vi) protein concentration. Results showed that positive protein identification could be done after protein separation by gel electrophoresis

  12. Management for Postoperative Complications of Breast Augmentation by Injected Polyacrylamide Hydrogel

    Microsoft Academic Search

    Qun Qiao; Xiancheng Wang; Jiaming Sun; Ru Zhao; Zhifei Liu; Yang Wang; Baodong Sun; Yinjun Yan; Keming Qi

    2005-01-01

    Polyacrylamide hydrogel, a new biomaterial, has been used for injected breast augmentation in China since 1997. A series of 30 patients with various complications after injected polyacrylamide hydrogel visited the author’s department. Most of these patients had undergone injection of both breasts. The average age of the patients was 27.6 years, and the time of consultation for the complications was

  13. Chemical gel barriers as low-cost alternative to containment and in situ cleanup of hazardous wastes to protect groundwater

    SciTech Connect

    NONE

    1997-01-01

    Chemical gel barriers are being considered as a low-cost alternative for containment and in situ cleanup of hazardous wastes to protect groundwater. Most of the available gels in petroleum application are non-reactive and relative impermeable, providing a physical barriers for all fluids and contaminants. However, other potential systems can be envisioned. These systems could include gels that are chemically reactive and impermeable such that most phase are captured by the barriers but the contaminants could diffuse through the barriers. Another system that is chemically reactive and permeable could have potential applications in selectivity capturing contaminants while allowing water to pass through the barriers. This study focused on chemically reactive and permeable gel barriers. The gels used in experiment are DuPont LUDOX SM colloidal silica gel and Pfizer FLOPAAM 1330S hydrolyzed polyacrylamide (HPAM) gel.

  14. Native American Healing Traditions

    Microsoft Academic Search

    Tarrell A. A. Portman; Michael T. Garrett

    2006-01-01

    Indigenous healing practices among Native Americans have been documented in the United States since colonisation. Cultural encapsulation has deterred the acknowledgement of Native American medicinal practices as a precursor to folk medicine and many herbal remedies, which have greatly influenced modern medicine. Understanding Native American healing practices requires helping professionals to have knowledge of Native American cultural belief systems about

  15. How deeply cells feel: methods for thin gels

    PubMed Central

    Buxboim, Amnon; Rajagopal, Karthikan; Brown, Andre’ E.X.; Discher, Dennis E.

    2010-01-01

    Tissue cells lack the ability to see or hear but have evolved mechanisms to feel into their surroundings and sense a collective stiffness. A cell can even sense the effective stiffness of rigid objects that are not in direct cellular contact – like the proverbial princess who feels a pea placed beneath soft mattresses. How deeply a cell feels into a matrix can be measured by assessing cell responses on a controlled series of thin and elastic gels that are affixed to a rigid substrate. Gel elasticity E is readily varied with polymer concentrations of now-standard polyacrylamide hydrogels, but to eliminate wrinkling and detachment of thin gels from an underlying glass coverslip, vinyl groups are bonded to the glass before polymerization. Gel thickness is nominally specified using micron-scale beads that act as spacers, but gels swell after polymerization as measured by z-section, confocal microscopy of fluorescent gels. Atomic force microscopy (AFM) is used to measure E at gel surfaces, employing stresses and strains that are typically generated by cells and yielding values for E that span a broad range of tissue microenvironments. To illustrate cell sensitivities to a series of thin-to-thick gels, the adhesive spreading of mesenchymal stem cells was measured on gel mimics of a very soft tissue (eg. brain, E ~ 1 kPa). Initial results show that cells increasingly respond to the rigidity of an underlying ‘hidden’ surface starting at about 10–20 µm gel thickness with a characteristic tactile length of less than about 5 µm. PMID:20454525

  16. Ultralow fouling polyacrylamide on gold surfaces via surface-initiated atom transfer radical polymerization.

    PubMed

    Liu, Qingsheng; Singh, Anuradha; Lalani, Reza; Liu, Lingyun

    2012-04-01

    In this work, polyacrylamide is investigated as an ultralow fouling surface coating to highly resist protein adsorption, cell adhesion, and bacterial attachment. Polyacrylamide was grafted on gold surfaces via surface-initiated atom transfer radical polymerization (ATRP). Protein adsorption from a wide range of biological media, including single protein solutions of fibrinogen, bovine serum albumin, and lysozyme, dilute and undiluted human blood serum, and dilute and undiluted human blood plasma, was studied by surface plasmon resonance (SPR). Dependence of the protein resistance on polyacrylamide film thickness was examined. With the optimal film thickness, the adsorption amount of all three single proteins on polyacrylamide-grafted surfaces was <3 pg/mm(2), close to the detection limit of SPR. The average nonspecific adsorptions from 10% plasma, 10% serum, 100% plasma, and 100% serum onto the polyacrylamide-grafted surfaces were 5, 6.5, 17, and 28 pg/mm(2), respectively, comparable (if not better) than the adsorption levels on poly(ethylene glycol) (PEG) and zwitterionic poly(sulfobetaine methacrylate) surfaces, the best antifouling materials known to date. The polyacrylamide-grafted surfaces were also shown strongly resistant to adhesion from bovine aortic endothelial cells and two bacterial species, Gram-positive Staphylococcus epidermidis ( S. epidermidis ) and Gram-negative Pseudomonas aeruginosa ( P. aeruginosa ). Strong hydrogen bond with water is considered the key attribute for the ultralow fouling properties of polyacrylamide. This is the first work to graft gold surfaces with polyacrylamide brushes via ATRP to achieve ultralow fouling surfaces, demonstrating that polyacrylamide is a promising alternative to traditional PEG-based antifouling materials. PMID:22385371

  17. Polymer gel dosimeters with reduced toxicity: a preliminary investigation of the NMR and optical dose response using different monomers

    NASA Astrophysics Data System (ADS)

    Senden, R. J.; DeJean, P.; McAuley, K. B.; Schreiner, L. J.

    2006-07-01

    In this work, three new polymer gel dosimeter recipes were investigated that may be more suitable for widespread applications than polyacrylamide gel dosimeters, since the extremely toxic acrylamide has been replaced with the less harmful monomers N-isopropylacrylamide (NIPAM), diacetone acrylamide and N-vinylformamide. The new gel dosimeters studied contained gelatin (5 wt%), monomer (3 wt%), N,N'-methylene-bis-acrylamide crosslinker (3 wt%) and tetrakis (hydroxymethyl) phosphonium chloride antioxidant (10 mM). The NMR response (R2) of the dosimeters was analysed for conditions of varying dose, dose rate, time post-irradiation, and temperature during irradiation and scanning. It was shown that the dose-response behaviour of the NIPAM/Bis gel dosimeter is comparable to that of normoxic polyacrylamide gel (PAGAT) in terms of high dose-sensitivity and low dependence on dose rate and irradiation temperature, within the ranges considered. The dose-response (R2) of NIPAM/Bis appears to be linear over a greater dose range than the PAGAT gel dosimeter. The effects of time post-irradiation (temporal instability) and temperature during NMR scanning on the R2 response were more significant for NIPAM/Bis dosimeters. Diacetone acrylamide and N-vinylformamide gel dosimeters possessed considerably lower dose-sensitivities. The optical dose-response, measured in terms of the attenuation coefficient for each polymer gel dosimeter, showed potential for the use of optical imaging techniques in future studies.

  18. Antimicrobial activity of silver/starch/polyacrylamide nanocomposite.

    PubMed

    Abdel-Halim, E S; Al-Deyab, Salem S

    2014-07-01

    A novel silver/starch/polyacrylamide nanocomposite hydrogel was prepared by grafting acrylamide onto starch in presence of silver nitrate by use of ammonium persulphate as an initiator and N,N-methylene-bisacrylamide as a crosslinking agent, then reducing the silver ions enclosed in the hydrogel structure to silver nanoparticles by treating the hydrogel with sodium hydroxide solution. All factors which affect the grafting/crosslinking reaction were optimized and the concentration of silver ion was changed from 0ppm to 50ppm. The produced nanocomposite hydrogel was characterized for its nanosilver content and the UV-spectra showed similar absorption spectra at wavelength 405nm for all AgNO3 concentrations but the plasmon showed increase in the intensity of the absorption peak as AgNO3 concentration incorporated to the hydrogel structure increases. The nanocomposite hydrogel was also characterized for its antimicrobial activity toward two types of bacteria and two types of fungi. The results showed that the hydrogel with 0ppm silver content has no antimicrobial activity, and that the antimicrobial activity expressed as inhibition zone increases as the silver content increases from 5ppm to 50ppm. PMID:24769214

  19. Infiltration of Wastewater and Simulated Rainwater as Affected by Polyacrylamide

    NASA Astrophysics Data System (ADS)

    Gardiner, Duane T.; Sun, Qingguo

    2002-08-01

    Irrigation reduces infiltration rates for subsequent irrigations or rains, thus decreasing the efficiency of water use and impacting watersheds in agricultural areas. Reduced infiltration causes greater runoff with its accompanying erosion, pollution, and sedimentation. Small rates of polyacrylamide (PAM) improve infiltration and reduce erosion on irrigated fields. The effects of PAM on infiltration of rainwater, the longevity of the effects of various rates of PAM, and the effects of repeated or intermittent PAM applications are not understood. This study measured the effects of four PAM application rates (0, 10, 25, and 40 ppm) on the subsequent infiltration of wastewater or simulated rainwater for seven weeks following the initial treatments. Also, effects of repeated and intermittent PAM applications on infiltration were determined. Hydraulic conductivity was determined for each soil column using the falling head method. Two soil types from the coastal plain of south Texas were tested -- a soil high in clay (Victoria) and a sandy loam (Willacy). Effects of PAM rates were significant, but effects of water type were not (P > 0.05). Benefits from single PAM applications disappeared within two weeks. Water enriched with PAM is so viscous and infiltrates so slowly that applying PAM in every irrigation event may not be feasible. However, repeating PAM applications every two weeks maintained high infiltration rates on the alternate weeks. This intermittent application of PAM may be a practical approach for improving infiltration rates on irrigated lands.

  20. Polyacrylamide medium for the electrophoretic separation of biomolecules

    DOEpatents

    Madabhushi, Ramakrishna S.; Gammon, Stuart A.

    2003-11-11

    A polyacryalmide medium for the electrophoretic separation of biomolecules. The polyacryalmide medium comprises high molecular weight polyacrylamides (PAAm) having a viscosity average molecular weight (M.sub.v) of about 675-725 kDa were synthesized by conventional red-ox polymerization technique. Using this separation medium, capillary electrophoresis of BigDye DNA sequencing standard was performed. A single base resolution of .about.725 bases was achieved in .about.60 minute in a non-covalently coated capillary of 50 .mu.m i.d., 40 cm effective length, and a filed of 160 V/cm at 40.degree. C. The resolution achieved with this formulation to separate DNA under identical conditions is much superior (725 bases vs. 625 bases) and faster (60 min. vs. 75 min.) to the commercially available PAAm, such as supplied by Amersham. The formulation method employed here to synthesize PAAm is straight-forward, simple and does not require cumbersome methods such as emulsion polymerizaiton in order to achieve very high molecular weights. Also, the formulation here does not require separation of PAAm from the reaction mixture prior to reconstituting the polymer to a final concentration. Furthermore, the formulation here is prepared from a single average mol. wt. PAAm as opposed to the mixture of two different average mo. wt. PAAm previously required to achieve high resolution.

  1. Purification of native myosin filaments from muscle.

    PubMed Central

    Hidalgo, C; Padrón, R; Horowitz, R; Zhao, F Q; Craig, R

    2001-01-01

    Analysis of the structure and function of native thick (myosin-containing) filaments of muscle has been hampered in the past by the difficulty of obtaining a pure preparation. We have developed a simple method for purifying native myosin filaments from muscle filament suspensions. The method involves severing thin (actin-containing) filaments into short segments using a Ca(2+)-insensitive fragment of gelsolin, followed by differential centrifugation to purify the thick filaments. By gel electrophoresis, the purified thick filaments show myosin heavy and light chains together with nonmyosin thick filament components. Contamination with actin is below 3.5%. Electron microscopy demonstrates intact thick filaments, with helical cross-bridge order preserved, and essentially complete removal of thin filaments. The method has been developed for striated muscles but can also be used in a modified form to remove contaminating thin filaments from native smooth muscle myofibrils. Such preparations should be useful for thick filament structural and biochemical studies. PMID:11606293

  2. Electrophoretic extraction of proteins from two-dimensional electrophoresis gel spots

    DOEpatents

    Zhang, Jian-Shi (Shanghai, CN); Giometti, Carol S. (Glenview, IL); Tollaksen, Sandra L. (Montgomery, IL)

    1989-01-01

    After two-dimensional electrophoresis of proteins or the like, resulting in a polyacrylamide gel slab having a pattern of protein gel spots thereon, an individual protein gel spot is cored out from the slab, to form a gel spot core which is placed in an extraction tube, with a dialysis membrane across the lower end of the tube. Replicate gel spots can be cored out from replicate gel slabs and placed in the extraction tube. Molten agarose gel is poured into the extraction tube where the agarose gel hardens to form an immobilizing gel, covering the gel spot cores. The upper end portion of the extraction tube is filled with a volume of buffer solution, and the upper end is closed by another dialysis membrane. Upper and lower bodies of a buffer solution are brought into contact with the upper and lower membranes and are provided with electrodes connected to the positive and negative terminals of a DC power supply, thereby producing an electrical current which flows through the upper membrane, the volume of buffer solution, the agarose, the gel spot cores and the lower membrane. The current causes the proteins to be extracted electrophoretically from the gel spot cores, so that the extracted proteins accumulate and are contained in the space between the agarose gel and the upper membrane. A high percentage extraction of proteins is achieved. The extracted proteins can be removed and subjected to partial digestion by trypsin or the like, followed by two-dimensional electrophoresis, resulting in a gel slab having a pattern of peptide gel spots which can be cored out and subjected to electrophoretic extraction to extract individual peptides.

  3. DEVELOPMENT OF POLYMER GEL SYSTEMS TO IMPROVE VOLUMETRIC SWEEP AND REDUCE PRODUCING WATER/OIL RATIOS

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Rajeev Jain; Tuan Nguyen

    2003-11-01

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of the first year of a three-year research program that is aimed at the understanding of the chemistry of gelation and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work has focused on a widely-applied system in field applications, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. The initial reaction between chromium acetate and one polymer is referred to as the uptake reaction. The uptake reaction was studied as functions of chromium and polymer concentrations and pH values. Experimental data were regressed to determine a rate equation that describes the uptake reaction of chromium by polyacrylamide. Pre-gel aggregates form and grow as the reactions between chromium acetate and polyacrylamide proceed. A statistical model that describes the growth of pre-gel aggregates was developed using the theory of branching processes. The model gives molecular weight averages that are expressed as functions of the conversion of the reactive sites on chromium acetate or on the polymer molecule. Results of the application of the model correlate well with experimental data of viscosity and weight-average molecular weight and gives insights into the gelation process. A third study addresses the flow of water and oil in rock material after a gel treatment. Previous works have shown that gel treatments usually reduce the permeability to water to a greater extent than the permeability to oil is reduced. This phenomenon is referred to as disproportionate permeability reduction (DPR). Flow experiments were conducted to determine the effect of polymer and chromium concentrations on DPR. All gels studied reduced the permeability to water by a greater factor than the factor by which the oil permeability was reduced. Greater DPR was observed as the concentrations of polymer and chromium were increased. Increased pressure gradients during oil flow decreased the oil permeability and the water permeability that was measured afterward. Lower pressure gradients that were applied subsequently moderately affected water permeabilities but did not affect oil permeabilities. A conceptual model of the mechanisms responsible for DPR is presented. Primary features of the model are (1) the development of flow channels through the gel by dehydration of the gel and by re-connection of pre-treatment, residual oil volume and (2) high flow resistance in the channels during water flow is caused by significant saturations of oil remaining in the channels.

  4. Analysis of white spot syndrome virus envelope protein complexome by two-dimensional blue native/SDS PAGE combined with mass spectrometry.

    PubMed

    Li, Zichong; Xu, Limei; Li, Fang; Zhou, Qing; Yang, Feng

    2011-07-01

    White spot syndrome virus (WSSV) is a large enveloped virus, but the organization of its envelope proteins remains largely unknown. In the present study, we used blue native polyacrylamide gel electrophoresis (BN-PAGE) and SDS-PAGE in combination with mass spectrometry to analyze the envelope protein complexome of WSSV. Our results show that the viral envelope consists of multi-protein complexes (MPCs). Within them, the envelope protein VP19 exists as a homotrimer, while another major envelope protein, VP28, mainly exists as a homotetramer. The most notable feature is that the majority of MPCs include VP26 and VP24, suggesting that these two proteins might serve as hub proteins to recruit low-abundance proteins to MPCs and play crucial roles in the process of protein complex formation. Furthermore, we found significant evidence for interactions between several low-abundance proteins, such as VP52B/VP38/VP33 and VP12/VP150. The result of this study may promote the further research on WSSV envelope assembly. PMID:21380712

  5. High-Speed Gel Filtration of Polypeptides in Some Denaturants

    Microsoft Academic Search

    T. Imamura; K. Konishi; M. Yokoyama

    1981-01-01

    The separation and analysis of proteins and polypeptides by use of a silica-based gel packing, G3000SW, for high-speed gel filtration are investigated. The peaks of bovine serum albumin, pepsin, trypsinogen, myoglobin and cytochrome c were completely separated in the presence of 0.2% SDS and 0.2 M sodium phosphate buffer (pH 7.0). The elution positions of native proteins, polypeptides in 8

  6. Subunit composition of wheat glutenin proteins, isolated by gel filtration in a dissociating medium

    Microsoft Academic Search

    Peter I. Payne; Kathryn G. Corfield

    1979-01-01

    Proteins were extracted from wheat meal or flour in 0.1 M acetic acid, 3 M urea and 0.01 M CTAB and fractionated in columns of cross-linked Sepharose in the same solvent. An heterogeneous fraction of high molecular weight eluted from the column which, when reduced and subjected to SDS-polyacrylamide-gel electrophoresis, separated into 12 components. Their molecular weights ranged from about

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

    Microsoft Academic Search

    Nakul Mandal; Steffen Heegaard; Jan Ulrik Prause; Bent Honoré; Henrik Vorum

    2010-01-01

    The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS). Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure reliable results. Current methods of protein

  8. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...3480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3480 Polyacrylamide polymer (modified cationic) denture...

  9. REACTIVE EXTRUSION OF STARCH-POLYACRYLAMIDE GRAFT COPOLYMERS USING VARIOUS STARCHES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of polyacrylamide and various substrates were prepared by reactive extrusion in a twin screw extruder using ammonium persulfate as initiator. Substrates included unmodified starches (corn, waxy maize, wheat, and potato), cationic starches, dextrin, dextran, and polyvinyl alcohol (P...

  10. Investigation of the properties of polyacrylamide-polyaniline composite and its application as a battery electrode

    SciTech Connect

    Bhat, N.V.; Joshi, N.V. (Univ. of Bombay, (India). Dept. of Chemical Technology)

    1993-11-20

    The composite films of polyacrylamide and polyaniline were prepared by polymerizing aniline using ammonium persulfate as an initiator in an aqueous solution containing poly-acrylamide. A film was then cast from this solution. The structural, dynamic mechanical, electrical, and thermal properties of these films have been studied. The infrared spectrum shows the presence of polyacrylamide as well as polyaniline in the composite film. The thermal analysis shows that the composite degrades slower than does the polyacrylamide alone. The dynamic mechanical analysis indicates that there is an increase in the glass transition temperature after the composite formation. The electrical conductivity has been found to increase by more than eight orders of magnitude. These composite films have also been suitably used as electrodes in secondary batteries.

  11. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  12. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  13. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  14. 21 CFR 872.3480 - Polyacrylamide polymer (modified cationic) denture adhesive.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...polymer (modified cationic) denture adhesive. 872.3480 Section 872.3480...polymer (modified cationic) denture adhesive. (a) Identification. A polyacrylamide polymer (modified cationic) denture adhesive is a device composed of...

  15. Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal

    PubMed Central

    Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

    2015-01-01

    During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200?mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM. PMID:26144551

  16. Waste-Activated Sludge Fermentation for Polyacrylamide Biodegradation Improved by Anaerobic Hydrolysis and Key Microorganisms Involved in Biological Polyacrylamide Removal.

    PubMed

    Dai, Xiaohu; Luo, Fan; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dong, Bin

    2015-01-01

    During the anaerobic digestion of dewatered sludge, polyacrylamide (PAM), a chemical conditioner, can usually be consumed as a carbon and nitrogen source along with other organic matter (e.g., proteins and carbohydrates in the sludge). However, a significant accumulation of acrylamide monomers (AMs) was observed during the PAM biodegradation process. To improve the anaerobic hydrolysis of PAM, especially the amide hydrolysis process, and to avoid the generation of the intermediate product AM, a new strategy is reported herein that uses an initial pH of 9, 200?mg COD/L of PAM and a fermentation time of 17 d. First, response surface methodology (RSM) was applied to optimize PAM removal in the anaerobic digestion of the sludge. The biological hydrolysis of PAM reached 86.64% under the optimal conditions obtained from the RSM. Then, the mechanisms for the optimized parameters that significantly improved the biological hydrolysis of PAM were investigated by the synergistic effect of the main organic compounds in the sludge, the floc size distribution, and the enzymatic activities. Finally, semi-continuous-flow experiments for a microbial community study were investigated based on the determination of key microorganisms involved in the biological hydrolysis of PAM. PMID:26144551

  17. Restoring Native Grasslands

    E-print Network

    Hays, K. Brian; Wagner, Matthew; Smeins, Fred; Wilkins, Neal

    2005-03-23

    Much of Texas' native grasslands has been converted to improved pastures and cropland, neither of which is suitable for wildlife habitat. Now, many landowners are interested in restoring native grasses because they are cheaper to produce for forage...

  18. Restoring Native Grasslands 

    E-print Network

    Hays, K. Brian; Wagner, Matthew; Smeins, Fred; Wilkins, Neal

    2005-03-23

    Much of Texas' native grasslands has been converted to improved pastures and cropland, neither of which is suitable for wildlife habitat. Now, many landowners are interested in restoring native grasses because they are cheaper to produce for forage...

  19. Native American Stereotypes

    NSDL National Science Digital Library

    Albion Middle School Library--Mrs. Bates

    2007-03-20

    You have been asked to write an opinion paper on the topic of naming sports teams' mascots after Native Americans. Use the following websites to find information to support your opinions. Why Dont Native Americans Like Sports Teams With Indian Mascots? Sports, Mascots, and Native Americans Native American Mascots: Racial Slur or Cherished Tradition To see another perspective on this topic, read the book Who Will Tell My Brother by Marlene Carvell. ...

  20. FRUIT & NUT NATIVE PECANS

    E-print Network

    Mukhtar, Saqib

    TEXAS FRUIT & NUT PRODUCTION NATIVE PECANS Larry Stein, Monte Nesbitt & Jim Kamas Extension Fruit Specialists, Texas AgriLife Extension There are 600,000 to one million acres of native pecans along is seldom over 20 mil- lion pounds. A native pecan management pro- gram should include nut production

  1. Native American Homeschooling Association.

    ERIC Educational Resources Information Center

    Rozon, Gina

    2000-01-01

    The Native American Home School Association helps Native parents to provide a good education free from the assimilationist tendencies of public school and to transmit Native values and culture. Discusses various home schooling styles, the effectiveness of home schooling in terms of academic achievement and socialization, and the effectiveness of…

  2. Native American Healing Traditions

    ERIC Educational Resources Information Center

    Portman, Tarrell A. A.; Garrett, Michael T.

    2006-01-01

    Indigenous healing practices among Native Americans have been documented in the United States since colonisation. Cultural encapsulation has deterred the acknowledgement of Native American medicinal practices as a precursor to folk medicine and many herbal remedies, which have greatly influenced modern medicine. Understanding Native American…

  3. Monitoring the Cross-Linking of a HPAm\\/Cr(III) Acetate Polymer Gel Using H NMR, UV Spectrophotometry, Bottle Testing, and Rheology

    Microsoft Academic Search

    Silvia Magnolia Vargas-Vasquez; Laura Beatriz Romero-Zerón; Rodney Macgregor; Senthil Gopalakrishnan

    2007-01-01

    The gelation of a polymer gel formulated at 40°C with 7500 mg\\/L of partly hydrolyzed polyacrylamide (HPAm) and 3000 mg\\/L of Cr(III) acetate 50% active was monitored for 72 h using H nuclear magnetic resonance (NMR) techniques, oscillatory rheology, bottle testing, and UV spectrophotometry. During the first 5 h, H NMR techniques detected changes in the polymer gel signal intensity and transverse relaxation that

  4. Intermediate steps in YBa 2 Cu 3 O 7? x synthesis by sol-gel method: YBaCuO oxycarbonate

    Microsoft Academic Search

    F. J. Gotor; P. Odier; M. Gervais; J. Choisnet

    1994-01-01

    High Tc-superconducting powders of the Y-Ba-Cu-O system are prepared by a solution-polyacrylamide gel using citric acid as a complexing agent. This method provides an easy way to prepare reactive YBaCuO powders by sol-gel synthesis. However this synthesis involves intermediate phases formation which impedes the obtention of the pure phase at low temperature. An intermediate oxycarbonate phase forms between 800° and

  5. Liquid chromatography and differential scanning calorimetry studies on the states of water in hydrophilic polymer gel packings in relation to retention selectivity

    Microsoft Academic Search

    Masami Shibukawa; Kaoru Aoyagi; Ryosaku Sakamoto; Koichi Oguma

    1999-01-01

    The amounts of water which exhibit selectivity to solutes in water-swollen hydrophilic polymer gel packings were determined by a liquid chromatographic method designed on the basis of the mobile phase electrolyte effects on the retention of ionic solutes. The estimated amounts of the water in three types of water-swollen hydrophilic polymer gels, a cross-linked dextran, poly(vinyl alcohol) and polyacrylamide, agree

  6. Probing structure-antifouling activity relationships of polyacrylamides and polyacrylates.

    PubMed

    Zhao, Chao; Zhao, Jun; Li, Xiaosi; Wu, Jiang; Chen, Shenfu; Chen, Qiang; Wang, Qiuming; Gong, Xiong; Li, Lingyan; Zheng, Jie

    2013-07-01

    We have synthesized two different polyacrylamide polymers with amide groups (polySBAA and polyHEAA) and two corresponding polyacrylate polymers without amide groups (polySBMA and polyHEA), with particular attention to the evaluation of the effect of amide group on the hydration and antifouling ability of these systems using both computational and experimental approaches. The influence of polymer architectures of brushes, hydrogels, and nanogels, prepared by different polymerization methods, on antifouling performance is also studied. SPR and ELISA data reveal that all polymers exhibit excellent antifouling ability to repel proteins from undiluted human blood serum/plasma, and such antifouling ability can be further enhanced by presenting amide groups in polySBAA and polyHEAA as compared to polySBMA and polyHEA. The antifouling performance is positively correlated with the hydration properties. Simulations confirm that four polymers indeed have different hydration characteristics, while all presenting a strong hydration overall. Integration of amide group with pendant hydroxyl or sulfobetaine group in polymer backbones is found to increase their surface hydration of polymer chains and thus to improve their antifouling ability. Importantly, we present a proof-of-concept experiment to synthesize polySBAA nanogels, which show a switchable property between antifouling and pH-responsive functions driven by acid-base conditions, while still maintaining high stability in undiluted fetal bovine serum and minimal toxicity to cultured cells. This work provides important structural insights into how very subtle structural changes in polymers can yield great improvement in biological activity, specifically the inclusion of amide group in polymer backbone/sidechain enables to obtain antifouling materials with better performance for biomedical applications. PMID:23562049

  7. Long-term, buffer-less, wet gel storage in non-sealed polyethylene bags.

    PubMed

    Kurien, Biji T; Scofield, R Hal

    2012-01-01

    Electrophoresed gels are normally fixed, stained, destained, and dried. Drying is normally carried out with commercial gel dryers or by drying between two cellophane sheets held together by two acrylic frames. Here, we report that stained and destained gels (7.5, 10, or 15%, denaturing or native gels; 0.4 or 1.5 mm in thickness) could be stored wet, unsealed, and without any storage buffer for several months at room temperature within flexible polyethylene bags without significant shrinking or protein diffusion. The gel remains hydrated because of the de facto sealing achieved by the polyethylene sheets (PS) adhering airtightly to the gel on either sides. The microsaturated environment generated by the thin film of water molecules trapped between the gel and the PS, along with the nonporous nature of the PS, apparently protects the gel from cracking as well as shrinking significantly. The intensity of stained proteins increased during storage probably from the slight gel shrinkage observed. Wet gel storage is useful (a) when low abundance protein spots from multiple two-dimensional electrophoresis gels have to be excised for in-gel tryptic digestion or electroelution and (b) for wet gel autoradiography. In addition to avoiding dryer contamination and saving drying time, these bags prevent the moist gel from sticking to X-ray film. Such storage could also prove useful for electrophoretic transfer of fixed and stained gels. PMID:22585508

  8. The nanoporous morphology of photopolymerized crosslinked polyacrylamide hydrogels

    E-print Network

    Wang, Jian

    2009-05-15

    are typicaly synthesized by chemicaly initiated fre radical co-polymerization of acrylamide and N, N'-methylene -bis- acrylamide (generaly refered to as simply bisacrylamide or ?bis?).Amonium persulfate (APS) is a commonly used initiator, in combination...L (6 M final urea concentration). Imediately before each experiment, 3 !L of a freshly prepared (10% w/v) aqueous amonium persulfate (APS) solution was added to 2 mL of the gel stock solution, along with 2.5 !L of a (0.4 % w/v) aqueous riboflavin...

  9. Genetic variation in Bromus tectorum (Poaceae): comparison between native and introduced populations

    Microsoft Academic Search

    Stephen J Novak; Richard N Mack

    1993-01-01

    The amount and distribution of genetic variation in 51 native (Eurasian and northern African) populations of Bromus tectorum were assessed at 25 loci using starch gel electrophoresis and were compared with our previous results for introduced (North American) populations of this predominantly cleistogamous grass. More alleles and variable loci were detected across populations in the native range than in North

  10. Unified Theory for Gel Electrophoresis and Gel Filtration

    Microsoft Academic Search

    David Rodbard; Andreas Chrambach

    1970-01-01

    Unified theory for gel electrophoresis and gel filtration: The behavior of macromolecules in gel filtration and gel electrophoresis may be predicted from Ogston's model for a random meshwork of fibers. This model has been generalized to apply to nonspherical molecules and to several gel types. The model provides equations for inter-relationships between mobility, partition coefficient, gel concentration, and molecular radius;

  11. 78 FR 70956 - 30-Day Notice of Proposed Information Collection: Assessment of Native American, Alaska Native...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ...Information Collection: Assessment of Native American, Alaska Native and Native Hawaiian...Information Collection: Assessment of Native American, Alaska Native and Native Hawaiian...funding though several programs to Native American and Alaskan Native...

  12. 78 FR 75365 - 30-Day Notice of Proposed Information Collection: Assessment of Native American, Alaska Native...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ...Information Collection: Assessment of Native American, Alaska Native and Native Hawaiian...Information Collection: Assessment of Native American, Alaska Native and Native Hawaiian...funding though several programs to Native American and Alaskan Native...

  13. Quantitative gel-electrophoretic determination of serum amylase isoenzyme distributions.

    PubMed

    Gillard, B K

    1979-11-01

    I report a direct, sensitive, quantitative method for determining serum amylase isoenzyme activity with commercially available reagents. Day-to-day reproducibility (CV) was 3--4% for the isoenzymes in normal serum; within-run precision was 8, 3, and 2% for low, normal and high isoenzyme activities. Amylase isoenzymes, separated into the pancreatic and salivary types by electrophoresis in polyacrylamide gel, are then quantified by directly incubating the gels in soluble-starch solution, staining with iodine, and densitometry. The proportion of pancreatic isoenzyme (47 normal sera) was 43 +/- 8% (mean +/- SD). Isoenzyme activities as low as 2% of normal can be measured accurately in 10 micro L of serum. The reproducibility, precision, and sensitivity indicate that the method is applicable to differential diagnosis of hyperamylasemia or hypoamylasemia, and is suited for monitoring the subtle changes in serum amylase isoenzyme distribution that may accompany disease progression or therapy. PMID:498502

  14. Content in Native Literature Programs.

    ERIC Educational Resources Information Center

    Grant, Agnes

    Including Native literature in school curricula is an important way of enhancing the Native student's self-concept and providing accurate Native cultural knowledge to Native and non-Native students alike. Nevertheless, Canadian school literature programs generally contain neither contemporary nor traditional Native literature. Some programs…

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

    PubMed Central

    2010-01-01

    The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS). Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure reliable results. Current methods of protein staining for 2D-PAGE, protein labelling for two-dimensional difference gel electrophoresis, gel-based expression analysis and protein identification by MS are summarised. The uses of gel-free MS-based strategies (MuDPIT, iTRAQ, ICAT and SILAC) are also discussed. Proteomic technologies promise to shed new light onto ocular disease processes that could lead to the discovery of strong novel biomarkers and therapeutic targets useful in many ophthalmic conditions. PMID:21406065

  16. Solids and nutrient removal from flushed swine manure using polyacrylamides

    SciTech Connect

    Vanotti, M.B.; Hunt, P.G.

    1999-12-01

    Most of the organic nutrients and reduced carbon (C) materials in liquid swine manure are contained in fine suspended particles that are not separated by available mechanical separators. Treatment with polyacrylamide (PAM) polymers prior to mechanical removal or gravity settling has the potential for enhancing solids-liquid separation, thus concentrating nitrogen (N), phosphorus (P), and organic C. In this work, the authors determined PAM charge and density characteristics most desirable for swine wastewater applications and established the optimum chemical requirement. Treatments were applied to flushed manure from two swine operations in North Carolina. Cationic PAMs significantly increased solids separation while performance of neutral and anionic types was not different from a control. Cationic PAMs with moderate-charge density (20%) were more effective than polymers with higher charge density. Flocs were large and effectively retained with a 1-mm screen. Optimum PAM rate varied with the amount of total suspended solids (TSS) in the liquid manure; 26 and 79 mg PAM/L for samples containing 1.5 and 4.1 g TSS/L, respectively. Corresponding TSS removal efficiencies were 90 to 94%. In contrast, screening without PAM treatment captured only 5 to 14% of the suspended solids. Polymer usage rate was consistent and averaged 2.0{degree} based on weight of dry solids produced. Volatile suspended solids (VSS) were highly correlated with TSS and comprised 79.5% of TSS. Chemical oxygen demand (COD) and organic nutrient concentrations in the effluent were also significantly decreased by PAM treatment. The decrease of COD concentration, an important consideration for odor control, was linearly related with removal of suspended solids, at a rate of 2.0 g COD/g TSS and 2.6 g COD/g VSS. Removal efficiency of organic N and P followed approximately a 1:1 relationship with removal efficiency of TSS. Chemical cost to capture 90% of the suspended solids was estimated to be $0.026 per hog per day ($2.79 per finished hog). Results obtained indicate that PAM treatment is very effective for removal of manure solids, COD, and organic nutrients from flushed swine effluents. The technology provides an attractive alternative to existing liquid manure handling methods for conserving nutrients and avoiding excessive nutrient application in areas where swine production is concentrated.

  17. In situ fabrication of ionic polyacrylamide-based preconcentrator on a simple poly(methyl methacrylate) microfluidic chip for capillary electrophoresis of anionic compounds.

    PubMed

    Yamamoto, Sachio; Hirakawa, Shingo; Suzuki, Shigeo

    2008-11-01

    A simple and efficient method was developed for fabrication of an anionic sample preconcentrator on a channel of a commercial poly(methyl methacrylate) (PMMA)-made microchip using no photolithography or etching technique. The originality of our preconcentrator is based on simple photochemical copolymerization of monomers using the following procedure: All channels of the PMMA-made microchip were filled with gel solution comprising acrylamide, N,N'-methylene-bisacrylamide, and 2-acrylamide-2-methylpropanesulfonic acid with riboflavin as a photocatalytic initiator. In situ polymerization near the cross of the sample outlet channel was performed by irradiation with an argon ion laser beam, which is also used as the light source for fluorometric detection. The electrokinetic property and electric repulsion between sample components and anionic groups on the polyacrylamide gel layer produce, trap, and concentrate anions within a few minutes at the interface of the cathodic side of the gel layer. This method displays concentration factors as high as 10 (5). The availability of ionic preconcentrator was demonstrated by applying sensitive analysis of oligosaccharides labeled with 8-aminopyrene-1,3,6-trisulfonate and some glycoproteins labeled with fluorescein isothiocyanate under various buffer systems. PMID:18841941

  18. Gel chemical transistor

    NASA Astrophysics Data System (ADS)

    Arai, Masanori; Gong, Jin; Makino, Masato; Kabir, M. Hasnat; Furukawa, Hidemitsu

    2015-04-01

    Shape Memory Gel (SMG) is one of the most interesting unique soft and wet materials. The elastic modulus of the SMG is changed by the kinds of solvent ( S-switch SMG). Here we have an idea that these properties are possibly applied to develop a novel gel-switch chemical semiconductor, named "Gel-con(ductor)". The Gel-con will be made from the combination of the different kinds of the S-switch gel membranes and is used to rectify the flux of the solvent in chemical circuits, where the solvent molecules behave as electron and hole.

  19. Toward sol-gel-based sensors

    SciTech Connect

    Jordan, J.D.; Ingersoll, C.M.; Dunbar, R.A. [State Univ. of New York, Buffalo, NY (United States)] [and others

    1995-12-31

    Advances in biotechnology have produced a variety of antibodies and other biomolecules that possess selective recognition capabilities. Current techniques for the immobilization of these biomolecules typically involve multistep derivatization of a primary substrate, which is labor intensive and often requires large volumes of costly reagents. Further, these immobilization chemistries often adversely affect the characteristic properties of the protein (e.g., the binding affinity). As a result, the need for fast, accurate, inexpensive, and simple to operate diagnostic assays escalates. Because of their room temperature processing, transparency, inertness, and tunable pore structure, sol-gel-derived composites represent promising chemical and biosensing platforms. To date, many researchers have entrapped proteins and enzymes in sol-gel monoliths, and found that they retain some of their native properties. Our group first reported on the affinity of a sol-gel entrapped antibody. However, although these biogel monoliths were promising, analyte diffusion through the monolith matrix is slow, resulting in long response times. Thus, it is clear that the next level of sol-gel-derived biosensor must depend on thin film technology. In the current work, the affinity of fluorescein entrapped within a sol-gel derived thin film for the anti fluorescent hapten, 5- (and 6-)-carboxy 4{prime}, 5{prime}-dimethylfluorescein, is investigated. A novel film preparation technique will be introduced, and the response and response times of these films as a function of processing and storage conditions will be discussed.

  20. Development of Polymer Gel Systems to Improve Volumetric Sweep and Reduce Producing Water/Oil Ratios

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Feiyan Chen

    2005-04-03

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of the third year of a 42 month research program that is aimed at an understanding of gelation chemistry and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work focused on a widely applied system in the field, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. Pre-gel aggregates form and grow as reactions between chromium acetate and polyacrylamide proceed. A mathematical model that describes uptake and crosslinking reactions as a function of time was derived. The model was probability based and provides molecular-weight averages and molecular-weight distributions of the pre-gel aggregates as a function of time and initial system conditions. A liquid chromatography apparatus to experimentally measure the size and molecular weight distributions of polymer samples was developed. The method worked well for polymer samples without the chromium crosslinker. Sample retention observed during measurements of gelant samples during the gelation process compromised the results. Other methods will be tested to measure size distributions of the pre-gel aggregates. Dissolution of carbonate minerals during the injection of gelants causes the pH of the gelant to increase. Chromium precipitates from solution at the higher pH values robbing the gelant of crosslinker. Experimental data on the transport of chromium acetate solutions through dolomite cores were obtained. A mathematical model that describes the transport of brine and chromium acetate solutions through rocks containing carbonate minerals was used to simulate the experimental results.

  1. Native American Powerpoint Project

    NSDL National Science Digital Library

    Miss Albright

    2009-07-09

    For this project students will research a Native American group that played an influential role in Alabama history. The students will then create a powerpoint describing the primary aspects of that group's heritage. Directions: 1. Choose any one of the Native American tribes we have been learning about in class. 2. Visit the following sites to learn more about the tribe that you have chosen: 1) Access Geneology 2) Native Languages ...

  2. Sol-Gel Glasses

    NASA Technical Reports Server (NTRS)

    Mukherjee, S. P.

    1985-01-01

    Multicomponent homogeneous, ultrapure noncrystalline gels/gel derived glasses are promising batch materials for the containerless glass melting experiments in microgravity. Hence, ultrapure, homogeneous gel precursors could be used to: (1) investigate the effect of the container induced nucleation on the glass forming ability of marginally glass forming compositions; and (2) investigate the influence of gravity on the phase separation and coarsening behavior of gel derived glasses in the liquid-liquid immiscibility zone of the nonsilicate systems having a high density phase. The structure and crystallization behavior of gels in the SiO2-GeO2 as a function of gel chemistry and thermal treatment were investigated. As are the chemical principles involved in the distribution of a second network former in silica gel matrix being investigated. The procedures for synthesizing noncrystalline gels/gel-monoliths in the SiO2-GeO2, GeO2-PbO systems were developed. Preliminary investigations on the levitation and thermal treatment of germania silicate gel-monoliths in the Pressure Facility Acoustic Levitator were done.

  3. Building Native Nations through Native Student's Commitment to Their Communities

    ERIC Educational Resources Information Center

    Lee, Tiffany S.

    2009-01-01

    One aspect of building Native nations entails motivating American Indian/Alaska Native youth to become committed to their communities so as to sustain and move forward with the goals of American Indian/Alaska Native nations. This study determined the impact of one Native American Studies department on its Native students' life goals. Through its…

  4. Reinforcement of a sugar-based bolaamphiphile/functionalized graphene oxide composite gel: rheological and electrochemical properties.

    PubMed

    Lee, Ji Ha; Ahn, Junho; Masuda, Mitsutoshi; Jaworski, Justyn; Jung, Jong Hwa

    2013-11-01

    A sugar-based bolaamphiphile/graphene oxide composite hydrogel has been prepared using simple mixing. Unlike the corresponding sugar-based native gel, the composite gel exhibits a fibrillar structure with a 10-20 nm fiber diameter. The composite gel forms an interdigitated bilayer structure incorporating intermolecular hydrogen-bonding interactions. The composite gel formation did not change the beneficial electrical properties of graphene offering the potential for integration of this new material into electronic systems. Interestingly, the mechanical and electrochemical properties of the composite gel are both dramatically enhanced when compared to the native gel, thereby reflecting that the functionalized graphene oxide layers are efficiently intercalated within the composite gel structure. PMID:24093646

  5. Identification of important allergens in German cockroach extracts by sodium dodecylsulfate–polyacrylamide gel electrophoresis and Western blot analysis

    Microsoft Academic Search

    Jonathan J. Musmand; W. Elliott Horner; Manuel Lopez; Samuel B. Lehrer

    1995-01-01

    Background: Despite recent advances in the purification and characterization of cockroach allergens, identification of clinically important allergens and their source have not been completely elucidated. This study investigated the allergen content of German cockroach (Blattella germanica) whole body (GWBE) and fecal (GFE) extracts. Methods: Sera from 37 subjects with asthma, with positive skin test results to cockroach, were used for

  6. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of ram seminal plasma proteins and their correlation with semen characteristics

    Microsoft Academic Search

    Wenbin Yue; Lei Shi; Zhiming Bai; Youshe Ren; Youying Zhao

    2009-01-01

    The present study was conducted to investigate fertility-associated proteins in ram seminal plasma and the correlation between specific protein and semen characteristics in sheep. Thirty-eight German merino sheep clinically proven healthy were chosen and divided into three groups according to fertility. Ejaculates were collected by an artificial vagina and semen characteristics (volume, pH value, motility, viability and concentration) were recorded.

  7. Silver staining of proteins in polyacrylamide gels: a general overview Thierry Rabilloud*, Laurent Vuillard+ , Claudine Gilly and Jean Jacques Lawrence

    E-print Network

    Boyer, Edmond

    . Abbreviations: AcOH: acetic acid; AcOK: potassium acetate; AMPSO:3-[(1,1 dimethyl-2hydroxyethyl) amino] 2-hydroxy 1 propanesulfonic acid; APS: ammonium persulfate; BES: N,N-Bis (hydroxyethyl)amino ethane sulfonic

  8. Database of two-dimensional polyacrylamide gel electrophoresis of proteins labeled with CyDye DIGE Fluor saturation dye.

    PubMed

    Fujii, Kazuyasu; Kondo, Tadashi; Yokoo, Hideki; Okano, Tetsuya; Yamada, Masayo; Yamada, Tesshi; Iwatsuki, Keiji; Hirohashi, Setsuo

    2006-03-01

    CyDye DIGE Fluor saturation dye (saturation dye, GE Healthcare Amersham Biosciences) enables highly sensitive 2-D PAGE. As the dye reacts with all reduced cysteine thiols, 2-D PAGE can be performed with a lower amount of protein, compared with CyDye DIGE Fluor minimal dye (GE Healthcare Amersham Biosciences), the sensitivity of which is equivalent to that of silver staining. We constructed a 2-D map of the saturation dye-labeled proteins of a liver cancer cell line (HepG2) and identified by MS 92 proteins corresponding to 123 protein spots. Functional classification revealed that the identified proteins had chaperone, protein binding, nucleotide binding, metal ion binding, isomerase activity, and motor activity. The functional distribution and the cysteine contents of the proteins were similar to those in the most comprehensive 2-D database of hepatoma cells (Seow et al.., Electrophoresis 2000, 21, 1787-1813), where silver staining was used for protein visualization. Hierarchical clustering on the basis of the quantitative expression profiles of the 123 characterized spots labeled with two charge- and mass-matched saturation dyes (Cy3 and Cy5) discriminated between nine hepatocellular carcinoma cell lines and primary cultured hepatocytes from five individuals, suggesting the utility of saturation dye and our database for proteomic studies of liver cancer. PMID:16429455

  9. Hydrolyzed Polyacrylamide- Polyethylenimine- Dextran Sulfate Polymer Gel System as a Water Shut-Off Agent in Unconventional Gas Reservoirs

    E-print Network

    Jayakumar, Swathika 1986-

    2012-07-09

    the gelation time .......................................................................... 14 II MATERIALS AND METHODS ............................................................................. 19 2.1 Chemicals used... for their stability at high temperatures include terephtalaldehyde, terephthalic acid, dihydroxynaphthalene, glutaric acid, gallic acid and dibasic esters. These cross linkers are classified...

  10. Highly effective removal of basic fuchsin from aqueous solutions by anionic polyacrylamide/graphene oxide aerogels.

    PubMed

    Yang, Xiaoxia; Li, Yanhui; Du, Qiuju; Sun, Jiankun; Chen, Long; Hu, Song; Wang, Zonghua; Xia, Yanzhi; Xia, Linhua

    2015-09-01

    Novel anionic polyacrylamide/graphene oxide aerogels were prepared by a freeze drying method and used to remove basic fuchsin from aqueous solutions. These aerogels were sponge-like solid with lightweight, fluffy and porous structure. The batch adsorption experiments were carried out to study the effect of various parameters, such as the solution pH, adsorbent dose, contact time and temperature on adsorption properties of basic fuchsin onto anionic polyacrylamide/graphene oxide aerogels. The kinetics of adsorption corresponded to the pseudo-second-order kinetic model. The Langmuir adsorption isotherm was suitable to describe the equilibrium adsorption process. The maximum adsorption capacity was up to 1034.3mg/g, which indicated that anionic polyacrylamide/graphene oxide aerogels were promising adsorbents for removing dyes pollutants from aqueous solution. PMID:25978557

  11. Gel electrophoresis of linear and star-branched DNA.

    PubMed

    Lau, Henry W; Archer, Lynden A

    2011-12-01

    The electrophoretic mobility of double-stranded DNA in polyacrylamide gel is investigated using an activated hopping model for the transport of a charged object within a heterogeneous medium. The model is premised upon a representation of the DNA path through the gel matrix as a series of traps with alternating large and small cross sections. Calculations of the trap dimensions from gel data show that the path imposes varying degrees of confinement upon migrating analytes, which retard their forward motion in a size-dependent manner. An expression derived for DNA mobility is shown to provide accurate predictions for the dynamics of linear DNA (67-622 bp) in gels of multiple concentrations. For star-branched DNA, the incorporation within the model of a length scale previously proposed to account for analyte architecture [Yuan et al., Anal. Chem. 78, 6179 (2006)] leads to mobility predictions that compare well with experimental results for a wide range of DNA shapes and molecular weights. PMID:22304125

  12. NEW ZEALAND'S NATIVE GREEN

    E-print Network

    Canterbury, University of

    NEW ZEALAND'S NATIVE GREEN MISTLETOES What can you do to help? Many green mistletoe populations mistletoes threatened? Although Ileostylus and Tupeia are the most common mistletoes in New Zealand the world, but New Zealand has eight native species that are found nowhere else (except Ileostylus which

  13. Historic Native Americans

    NSDL National Science Digital Library

    Miss G

    2011-10-27

    What are the four historic Native American tribes and what are different things involved in their culture? Teacher will give you sheet and as you discover new facts about each historic Native American tribe, write down the type of food they ate and another fact about them on this sheet. Graphic First let's learn some background information ...

  14. Native American Health

    Microsoft Academic Search

    Danielle Carlock

    2006-01-01

    Health disparities between Native Americans and the general population of the United States are a major health concern. Traditional healing and culturally competent health care offer much promise in raising the health status of Native Americans. Traditional healing, although uniquely practiced by each indigenous culture, is generally a system of medicine based on the inseparability of mind, body, and spirit.

  15. Native SAD is maturing

    PubMed Central

    Rose, John P.; Wang, Bi-Cheng; Weiss, Manfred S.

    2015-01-01

    Native SAD phasing uses the anomalous scattering signal of light atoms in the crystalline, native samples of macromolecules collected from single-wavelength X-ray diffraction experiments. These atoms include sodium, magnesium, phosphorus, sulfur, chlorine, potassium and calcium. Native SAD phasing is challenging and is critically dependent on the collection of accurate data. Over the past five years, advances in diffraction hardware, crystallographic software, data-collection methods and strategies, and the use of data statistics have been witnessed which allow ‘highly accurate data’ to be routinely collected. Today, native SAD sits on the verge of becoming a ‘first-choice’ method for both de novo and molecular-replacement structure determination. This article will focus on advances that have caught the attention of the community over the past five years. It will also highlight both de novo native SAD structures and recent structures that were key to methods development. PMID:26175902

  16. GEL ELECTROPHORETIC ISOLATION, IN THE HUNDRED MICROGRAM RANGE, OF RECOMBINANT SDS-SYNTAXIN FROM SEA URCHIN EGG CORTICAL VESICLES

    Microsoft Academic Search

    Y.-M. Li; A. Chrambach

    2001-01-01

    Recombinant urchin syntaxin [Xa cut], electrophoresed at pH 9.0 (25 °C) or 10.2 (0 °C) in a discontinuous Tris-chloride-glycinate buffer system in the presence of 0.03% SDS in the catholyte, exhibits a multicomponent pattern in gels of a polyacrylamide concentration of 12% and 3% crosslinking. The position in the pattern of the syntaxin band was identified by reference to electropherograms

  17. A gel probe equilibrium sampler for measuring arsenic porewater profiles and sorption gradients in sediments: I. Laboratory development.

    PubMed

    Campbell, Kate M; Root, Robert; O'Day, Peggy A; Hering, Janet G

    2008-01-15

    A gel probe equilibrium sampler has been developed to study arsenic (As) geochemistry and sorption behavior in sediment porewater. The gels consist of a hydrated polyacrylamide polymer, which has a 92% water content. Two types of gels were used in this study. Undoped (clear) gels were used to measure concentrations of As and other elements in sediment porewater. The polyacrylamide gel was also doped with hydrous ferric oxide (HFO), an amorphous iron (Fe) oxyhydroxide. When deployed in the field, HFO-doped gels introduce a fresh sorbent into the subsurface thus allowing assessment of in situ sorption. In this study, clear and HFO-doped gels were tested under laboratory conditions to constrain the gel behavior prior to field deployment. Both types of gels were allowed to equilibrate with solutions of varying composition and re-equilibrated in acid for analysis. Clear gels accurately measured solution concentrations (+/-1%), and As was completely recovered from HFO-doped gels (+/-4%). Arsenic speciation was determined in clear gels through chromatographic separation of the re-equilibrated solution. For comparison to speciation in solution, mixtures of As(III) and As(V) adsorbed on HFO embedded in gel were measured in situ using X-ray absorption spectroscopy (XAS). Sorption densities for As(III) and As(V) on HFO embedded in gel were obtained from sorption isotherms at pH 7.1. When As and phosphate were simultaneously equilibrated (in up to 50-fold excess of As) with HFO-doped gels, phosphate inhibited As sorption by up to 85% and had a stronger inhibitory effect on As(V) than As(III). Natural organic matter (>200 ppm) decreased As adsorption by up to 50%, and had similar effects on As(V) and As(III). The laboratory results provide a basis for interpreting results obtained by deploying the gel probe in the field and elucidating the mechanisms controlling As partitioning between solid and dissolved phases in the environment. PMID:18284153

  18. A gel probe equilibrium sampler for measuring arsenic porewater profiles and sorption gradients in sediments: I. Laboratory development

    USGS Publications Warehouse

    Campbell, K.M.; Root, R.; O'Day, P. A.; Hering, J.G.

    2008-01-01

    A gel probe equilibrium sampler has been developed to study arsenic (As) geochemistry and sorption behavior in sediment porewater. The gels consist of a hydrated polyacrylamide polymer, which has a 92% water content. Two types of gels were used in this study. Undoped (clear) gels were used to measure concentrations of As and other elements in sediment porewater. The polyacrylamide gel was also doped with hydrous ferric oxide (HFO), an amorphous iron (Fe) oxyhydroxide. When deployed in the field, HFO-doped gels introduce a fresh sorbent into the subsurface thus allowing assessment of in situ sorption. In this study, clear and HFO-doped gels were tested under laboratory conditions to constrain the gel behavior prior to field deployment. Both types of gels were allowed to equilibrate with solutions of varying composition and re-equilibrated in acid for analysis. Clear gels accurately measured solution concentrations (??1%), and As was completely recovered from HFO-doped gels (??4%). Arsenic speciation was determined in clear gels through chromatographic separation of the re-equilibrated solution. For comparison to speciation in solution, mixtures of As(III) and As(V) adsorbed on HFO embedded in gel were measured in situ using X-ray absorption spectroscopy (XAS). Sorption densities for As(III) and As(V) on HFO embedded in gel were obtained from sorption isotherms at pH 7.1. When As and phosphate were simultaneously equilibrated (in up to 50-fold excess of As) with HFO-doped gels, phosphate inhibited As sorption by up to 85% and had a stronger inhibitory effect on As(V) than As(III). Natural organic matter (>200 ppm) decreased As adsorption by up to 50%, and had similar effects on As(V) and As(III). The laboratory results provide a basis for interpreting results obtained by deploying the gel probe in the field and elucidating the mechanisms controlling As partitioning between solid and dissolved phases in the environment. ?? 2008 American Chemical Society.

  19. Process ceramic fibers by Sol-Gel

    SciTech Connect

    Fernandez de, M.E.P.; Kang, Cheolho; Mangonon, P.L.

    1993-09-01

    The Sol-Gel process may transform the materials of construction chemical engineers make and use--thin films, fibers, and powders. The advantage of the Sol-Gel technology is the ability to produce high purity products at low temperatures. For example, silica film is used to passivate integrated circuits. To achieve this, the native silicon substrate now is oxidized at about 1,000C for a short period of time. At this temperature, diffusion of the dopant atoms may be induced to alter the electronic properties of the chip. In contrast, the film application using Sol-Gel may be done at 400-600C. Another example is the interest in ceramic fibers to incorporate in fiber-reinforced ceramic matrix composite materials. The latter is considered an enabling technology for the 21st Century high-speed civil transport plane (NASA) and the National Aerospace plane (X-30). Glass and ceramic fibers have been prepared conventionally by drawing or blowing a high temperature melt through an orifice. The traditional process requires the conversion of the raw materials into a homogeneous, high temperature melt, which makes producing fibers based on materials having high melting points or materials that are immiscible in the liquid state difficult. The Sol-Gel process applied to the production of fibers offers an advantage over the conventional method, since the fibers are drawn from the Gel at low temperatures and then are converted to glass or ceramics by heating the fibers at high temperatures, T[lt]600C. Also by using this technique there is the potential to produce glasses of new compositions with high purity and homogeneity. This article will briefly discuss the polymerization aspect of the Sol-Gel process. The chemical, physical, and rheological aspects of the process to produce the desired product will be discussed.

  20. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2004-09-30

    This report describes work performed during the third and final year of the project, ''Conformance Improvement Using Gels.'' Corefloods revealed throughput dependencies of permeability reduction by polymers and gels that were much more prolonged during oil flow than water flow. This behavior was explained using simple mobility ratio arguments. A model was developed that quantitatively fits the results and predicts ''clean up'' times for oil productivity when production wells are returned to service after application of a polymer or gel treatment. X-ray computed microtomography studies of gels in strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene suggested that oil penetration through gel-filled pores occurs by a gel-dehydration mechanism, rather than gel-ripping or gel-displacement mechanisms. In contrast, analysis of data from the University of Kansas suggests that the gel-ripping or displacement mechanisms are more important in more permeable, strongly water-wet sandpacks. These findings help to explain why aqueous gels can reduce permeability to water more than to oil under different conditions. Since cement is the most commonly used material for water shutoff, we considered when gels are preferred over cements. Our analysis and experimental results indicated that cement cannot be expected to completely fill (top to bottom) a vertical fracture of any width, except near the wellbore. For vertical fractures with apertures less than 4 mm, the cement slurry will simply not penetrate very far into the fracture. For vertical fractures with apertures greater than 4 mm, the slurry may penetrate a substantial distance into the bottom part of the fracture. However, except near the wellbore, the upper part of the fracture will remain open due to gravity segregation. We compared various approaches to plugging fractures using gels, including (1) varying polymer content, (2) varying placement (extrusion) rate, (3) using partially formed gels, (4) using combinations of high and low molecular weight (Mw) polymers, (5) using secondary crosslinking reactions, (6) injecting un-hydrated polymer particles, and (7) incorporating particulates. All of these methods showed promise in some aspects, but required performance improvements in other aspects. All materials investigated to date showed significant performance variations with fracture width. High pressure gradients and limited distance of penetration are common problems in tight fractures. Gravity segregation and low resistance to breaching are common problems in wide fractures. These will be key issues to address in future work. Although gels can exhibit disproportionate permeability reduction in fractures, the levels of permeability reduction for oil flow are too high to allow practical exploitation in most circumstances. In contrast, disproportionate permeability reduction provided by gels that form in porous rock (adjacent to the fractures) has considerable potential in fractured systems.

  1. Gelation behavior of native and acetylated konjac glucomannan.

    PubMed

    Huang, Long; Takahashi, Rheo; Kobayashi, Shinsaku; Kawase, Tokuzo; Nishinari, Katsuyoshi

    2002-01-01

    Gelation kinetics of native and acetylated konjac glucomannan (KGM) samples in the presence of alkali (sodium carbonate) was studied by dynamic viscoelastic measurements. Molecular weight and other molecular parameters of KGM were determined by static light scattering and viscosity measurements. It was found that KGM molecules were degraded during acetylation treatment, but the molecular weights of acetylated samples were almost independent of the degree of acetylation (DA) and were about a half of that of a native sample. At a fixed alkaline concentration, increasing concentration of KGM or temperature shortened the gelation time, but increasing DA delayed it. The deacetylation reaction and subsequent aggregation process of acetylated samples needed longer time than that of native sample, and acetylated samples formed finally more elastic gels. It implied that the presence of acetyl groups exerts a strong influence on gelation behavior of KGM. It was suggested that the gelation rate of acetylated KGM and native KGM, which depends on the alkaline concentration and temperature, is an important factor that determines the elastic modulus of gels. This was supported by the experimental finding that the saturated elastic modulus tends to the same value when the ratio of alkali concentration to acetylated groups was kept constant. In slower gelation processes, junction zones are more homogeneously distributed and more numerous, leading to the more elastic gels. PMID:12425668

  2. Gelation Rheology and Water Absorption Behavior of Semi-Interpenetrating Polymer Networks of Polyacrylamide and Carboxymethyl Cellulose

    Microsoft Academic Search

    Jamal Aalaie; Ebrahim Vasheghani-Farahani; Ali Rahmatpour; Mohammad Ali Semsarzadeh

    2012-01-01

    Gelation rheology and swelling behavior of novel semi-interpenetrating polymer network (semi-IPN) hydrogels based on polyacrylamide are described. These hydrogels were prepared by solution crosslinking of partially hydrolyzed polyacrylamide and carboxymethyl cellulose (CMC), using chromium triacetate. Effects of CMC content on the gelation process and swelling behavior in tap water and different electrolyte solutions were investigated. Study of the gelation behavior

  3. Gel Shift Assay for Detection of TBP-DNA Complexes and Mot1 activity 6% Polyacrylamide Gel (14 cm X 16 cm X 0.2 cm)

    E-print Network

    Auble, David

    0.5 nM) 0.2 µl 0.5 mg/ml poly [dG-dC] (Amersham 27-7910-02) 2.0 µl 1.0% Brij 58 (Sigma P-5884) TBP, Brij 58 and TBP (if it doesn't vary); dispense to tubes at room temperature. Add Mot1 as indicated. Mix

  4. Responsive Gel-Gel Phase Transitions in Artificially Engineered Protein Hydrogels

    NASA Astrophysics Data System (ADS)

    Olsen, B. D.

    2012-02-01

    Artificially engineered protein hydrogels provide an attractive platform for biomedical materials due to their similarity to components of the native extracellular matrix. Engineering responsive transitions between shear-thinning and tough gel phases in these materials could potentially enable gels that are both shear-thinning and tough to be produced as novel injectable biomaterials. To engineer a gel with such transitions, a triblock copolymer with thermoresponsive polymer endblocks and an artificially engineered protein gel midblock is designed. Temperature is used to trigger a transition from a single network protein hydrogel phase to a double network phase with both protein and block copolymer networks present at different length scales. The thermodynamics of network formation and resulting structural changes are established using small-angle scattering, birefringence, and dynamic scanning calorimetry. The formation of the second network is shown to produce a large, nonlinear increase in the elastic modulus as well as enhancements in creep compliance and toughness. Although the gels show yielding behavior in both the single and double network regimes, a qualitative change in the deformation mechanism is observed due to the structural changes.

  5. Nonlinear Strain Stiffening Is Not Sufficient to Explain How Far Cells Can Feel on Fibrous Protein Gels

    PubMed Central

    Rudnicki, Mathilda S.; Cirka, Heather A.; Aghvami, Maziar; Sander, Edward A.; Wen, Qi; Billiar, Kristen L.

    2013-01-01

    Recent observations suggest that cells on fibrous extracellular matrix materials sense mechanical signals over much larger distances than they do on linearly elastic synthetic materials. In this work, we systematically investigate the distance fibroblasts can sense a rigid boundary through fibrous gels by quantifying the spread areas of human lung fibroblasts and 3T3 fibroblasts cultured on sloped collagen and fibrin gels. The cell areas gradually decrease as gel thickness increases from 0 to 150 ?m, with characteristic sensing distances of >65 ?m below fibrin and collagen gels, and spreading affected on gels as thick as 150 ?m. These results demonstrate that fibroblasts sense deeper into collagen and fibrin gels than they do into polyacrylamide gels, with the latter exhibiting characteristic sensing distances of <5 ?m. We apply finite-element analysis to explore the role of strain stiffening, a characteristic mechanical property of collagen and fibrin that is not observed in polyacrylamide, in facilitating mechanosensing over long distances. Our analysis shows that the effective stiffness of both linear and nonlinear materials sharply increases once the thickness is reduced below 5 ?m, with only a slight enhancement in sensitivity to depth for the nonlinear material at very low thickness and high applied traction. Multiscale simulations with a simplified geometry predict changes in fiber alignment deep into the gel and a large increase in effective stiffness with a decrease in substrate thickness that is not predicted by nonlinear elasticity. These results suggest that the observed cell-spreading response to gel thickness is not explained by the nonlinear strain-stiffening behavior of the material alone and is likely due to the fibrous nature of the proteins. PMID:23823219

  6. CONFORMANCE IMPROVEMENT USING GELS

    SciTech Connect

    Randall S. Seright

    2004-03-01

    This technical progress report describes work performed from September 1, 2003, through February 29, 2004, for the project, ''Conformance Improvement Using Gels.'' We examined the properties of several ''partially formed'' gels that were formulated with a combination of high and low molecular weight HPAM polymers. After placement in 4-mm-wide fractures, these gels required about 25 psi/ft for brine to breach the gel (the best performance to date in fractures this wide). After this breach, stabilized residual resistance factors decreased significantly with increased flow rate. Also, residual resistance factors were up to 9 times greater for water than for oil. Nevertheless, permeability reduction factors were substantial for both water and oil flow. Gel with 2.5% chopped fiberglass effectively plugged 4-mm-wide fractures if a 0.5-mm-wide constriction was present. The ability to screen-out at a constriction appears crucial for particulate incorporation to be useful in plugging fractures. In addition to fiberglass, we examined incorporation of polypropylene fibers into gels. Once dispersed in brine or gelant, the polypropylene fibers exhibited the least gravity segregation of any particulate that we have tested to date. In fractures with widths of at least 2 mm, 24-hr-old gels (0.5% high molecular weight HPAM) with 0.5% fiber did not exhibit progressive plugging during placement and showed extrusion pressure gradients similar to those of gels without the fiber. The presence of the fiber roughly doubled the gel's resistance to first breach by brine flow. The breaching pressure gradients were not as large as for gels made with high and low molecular weight polymers (mentioned above). However, their material requirements and costs (i.e., polymer and/or particulate concentrations) were substantially lower than for those gels. A partially formed gel made with 0.5% HPAM did not enter a 0.052-mm-wide fracture when applying a pressure gradient of 65 psi/ft. This result suggests a lower limit of fracture width for entry of formed or partially formed gels (when reasonable pressure gradients are applied). In unfractured porous rock, we investigated the time dependence of oil and water permeabilities during various cycles of oil and water injection after placement of a Cr(III)-acetate-HPAM gel. Permeability to water stabilized rapidly (within 1 pore volume, PV), while permeability to oil stabilized gradually over the course of 100 PV. The behavior was surprisingly insensitive to core material (strongly water-wet Berea sandstone and strongly oil-wet porous polyethylene), core permeability (740 to 10,000 md), and applied pressure gradient (10 to 100 psi/ft).

  7. Modeling chemoresponsive polymer gels.

    PubMed

    Kuksenok, Olga; Deb, Debabrata; Dayal, Pratyush; Balazs, Anna C

    2014-01-01

    Stimuli-responsive gels are vital components in the next generation of smart devices, which can sense and dynamically respond to changes in the local environment and thereby exhibit more autonomous functionality. We describe recently developed computational methods for simulating the properties of such stimuli-responsive gels in the presence of optical, chemical, and thermal gradients. Using these models, we determine how to harness light to drive shape changes and directed motion in spirobenzopyran-containing gels. Focusing on oscillating gels undergoing the Belousov-Zhabotinksy reaction, we demonstrate that these materials can spontaneously form self-rotating assemblies, or pinwheels. Finally, we model temperature-sensitive gels that encompass chemically reactive filaments to optimize the performance of this system as a homeostatic device for regulating temperature. These studies could facilitate the development of soft robots that autonomously interconvert chemical and mechanical energy and thus perform vital functions without the continuous need of external power sources. PMID:24498954

  8. Polyacrylamide-treated kaolin: A fabric study Sungho Kim, Angelica M. Palomino

    E-print Network

    Palomino, Angelica M.

    is face-to-face association due to polymer bridging. A relationship is found between polymer mineral particle systems. Polymers with deliberately chosen characteristics, such as molecular mass development in a clay­polymer system, specifically kaolin­polyacrylamide systems over a wide range of solids

  9. USING POLYACRYLAMIDE TO CONTROL EROSION ON AGRICULTURAL AND DISTURBED SOILS IN RAINFED AREAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of anionic polyacrylamide (PAM) as an erosion control soil amendment has been studied at the USDA-ARS National Soil Erosion Research Lab since the early 1990's. An initial field experiment in Indiana using simulated rainfall on a sloping silt loam soil found that 20 kg ha-1 of PAM could reduce s...

  10. Polyacrylamide molecular weight and phosphogypsum effects on infiltration and erosion in semi-arid soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of semi-arid soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  11. Rheological Monitoring of Polyacrylamide Gelation: Importance of Cross-Link Density and Temperature

    E-print Network

    Rheological Monitoring of Polyacrylamide Gelation: Importance of Cross-Link Density and Temperature modulus G and viscous modulus G are measured in real time during the gelation which takes place directly such as elasticity. Kinetics of in situ gelation and resulting rheological properties of different speci

  12. Polyacrylamide Molecular Weight and Phosphogypsum Effects on Infiltration and Erosion in Semi-Arid Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of semi-arid soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  13. Effects of polyacrylamide and organic matter on microbes associated to soil aggregation of Norfolk loamy sand

    Microsoft Academic Search

    T. C. Caesar-TonThat; W. J. Busscher; J. M. Novak; J. F. Gaskin; Y. Kim

    2008-01-01

    Polyacrylamide (PAM) has been reported to increase aggregation and improve soil physical properties in loamy sand soils, but nothing is known about the effects of PAM on microbes involved in aggregate formation. We studied the effects of PAM (0, 30 and 120mgkg?1) and organic matter (wheat [Triticum aestivum] and pecan [Carya illinoinensis]) incubated in a Norfolk soil (a blend of

  14. Feasibility study of the anaerobic digestion of dewatered pig slurry by means of polyacrylamide

    Microsoft Academic Search

    E. Campos; M. Almirall; J. Mtnez-Almela; J. Palatsi; X. Flotats

    2007-01-01

    Liquid livestock waste can be managed by separating liquid and solid fractions then treating each separately by applying best avail- able technology, such as anaerobic digestion for the solid fraction. There is an increasing use of polyacrylamide (PAM) as a flocculant agent to improve solid-liquid separation. In the present work, the anaerobic toxicity of PAM residues and the optimal range

  15. Feasibility study of the anaerobic digestion of dewatered pig slurry by means of polyacrylamide

    Microsoft Academic Search

    E. Campos; M. Almirall; J. Mtnez-Almela; J. Palatsi; X. Flotats

    2008-01-01

    Liquid livestock waste can be managed by separating liquid and solid fractions then treating each separately by applying best available technology, such as anaerobic digestion for the solid fraction. There is an increasing use of polyacrylamide (PAM) as a flocculant agent to improve solid–liquid separation. In the present work, the anaerobic toxicity of PAM residues and the optimal range of

  16. USE OF POLYACRYLAMIDE IN SIMULATED LAND APPLICATION OF LAGOON EFFLUENT: PART II. NUTRIENT LOSS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land application of agricultural wastewater can contribute to eutrophication of water bodies by increasing the quantities of dissolved and particulate nutrients that are transported in runoff during rain storm events. Anionic polyacrylamide (PAM) is a soil amendment that has been shown to reduce so...

  17. Production of a polyacrylamide solution used in an oil recovery process

    SciTech Connect

    Luetzelschwab, W.E.

    1987-01-06

    A process is described for recovering oil from a subterranean oil-bearing formation having performance demands comprising the steps of: determining the performance demands of the formation; determining correlations between an initial polymerization reaction parameter of initiator level and partially hydrolyzed polyacrylamide solution properties of screen factor and viscosity, each correlation having a discontinuity; selecting a value of the initiator level below each discontinuity such that the selected value of the initiator level is capable of producing a partially hydrolyzed polyacrylamide solution having values of the properties of viscosity and screen factor relatively sensitive to varying the initiator level and capable of meeting the performance demands of the formation; producing the partially hydrolyzed polyacrylamide solution having the values of the properties relatively sensitive to varying the initiator level and capable of meeting the performance demands by polymerizing an acrylamide monomer using a polymerization initiator at the selected value; and injecting the partially hydrolyzed polyacrylamide solution into the formation to improve oil recovery therefrom.

  18. Polyacrylamide effects on aggregate and structure stability of soils with different clay mineralogy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adding anionic polyacrylamide (PAM) to soils stabilizes existing aggregates and improves bonding between and aggregation of soil particles. However, the dependence of PAM efficacy as an aggregate stabilizing agent with soils having different clay mineralogy has not been studied. Sixteen soil samples...

  19. Investigations on synthesis and characterization of functionalized graphene sheets-polyacrylamide composites

    Microsoft Academic Search

    Ratnesh Pandey; Kalpana Awasthi; R. S. Tiwari; O. N. Srivastava

    2010-01-01

    The functionalized graphene sheets (FGS)-polyacrylamide (PAM) composite films have been prepared by solution cast technique. The FGS have been synthesized by thermal exfoliation of graphite oxide. Several composites with different weight % (between 0 to 25 wt %) of FGS loading in PAM have been prepared and characterized by XRD, SEM, TEM and FTIR spectroscopy. FTIR analysis revealed the existence

  20. Effects of Polyacrylamide and Organic Matter on Microbes associated to Soil Aggregation of Norfolk Loamy Sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyacrylamide (PAM, anionic formulation of molecular size 12 MDa and 35% charge density) has been reported to increase aggregation and improve soil physical properties in United States southeastern Coastal Plain loamy sand soils, but nothing is known about the effects of PAM on microbes associated ...

  1. Erosion control practices integrated with polyacrylamide for nutrient reduction in rill irrigation runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to assess soil conservation practices for improving water quality of return flows from rill irrigation in the Yakima River Basin, Washington, by combining patch application of polyacrylamide (PAM) with an additional erosion control practice. A two-year field study ...

  2. Aggregate stability as affected by polyacrylamide molecular weight, soil texture and water quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The favorable effects of the environmentally friendly, non toxic, anionic polyacrylamide (PAM) as a soil conditioner have long been established. However, some uncertainties exist regarding the effects of PAM molecular weight (MW) on its performance as a soil amendment and the ability of PAM to penet...

  3. Soil aggregate stability as affected by clay mineralogy and polyacrylamide addition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of polyacrylamide (PAM) to soil leads to stabilization of existing aggregates and improved bonding between, and aggregation of adjacent soil particles However, the dependence of PAM efficacy as an aggregate stabilizing agent on soil-clay mineralogy has not been studied. Sixteen soil sam...

  4. Effects of Polyacrylamide Molecular Weight, Soil Texture and Electrolyte Concentration on Drainable Porosity and Aggregate Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The literature reports on the intricate relations between soil type and molecular weight (MW) of polyacrylamide (PAM) with respect to PAM efficacy as a soil conditioner. This relation may depend on the ability of PAM to penetrate into aggregates and thus stabilize both outer and inner aggregate surf...

  5. Chemical modification of a polyacrylamide: Enhanced decontamination of soils and surfaces after a nuclear accident

    Microsoft Academic Search

    Agnés Arnaud; S. Coen; A. Jouve; M. Lelaidier; A. Perichaud

    1995-01-01

    This contribution concerns the decontamination of soils and surfaces polluted by cesium and strontium after a nuclear accident. The decontamination rate by means of an industrial polyacrylamide previously selected for its mechanical covering properties is studied. The characteristics of the polymer and its cation-exchange capacity (CEC) are specified. The chemical modification of the polymer, involving a crosslinking path and functional

  6. Native American Times

    NSDL National Science Digital Library

    The Native American Times makes good on its promise to deliver "today's independent Indian news." The site has a clean design that includes ten sections covering topics like business, culture, education, sports, and powwows. The News area offers a nice digest of what's going on in several areas of interest to Native Americans, with topical headlines that include "Cherokee Art Market Announces Winners" and "Yakama Maintain Wild Horse Race Tradition." The site also includes a great jobs area for folks who might be looking for Native American-focused work in public policy, community development, technology, and other fields.

  7. Use of an acid-labile surfactant as an SDS substitute for gel electrophoresis and proteomic analysis.

    PubMed

    Zeller, Martin; Brown, Elizabeth K; Bouvier, Edouard S P; König, Simone

    2002-03-01

    Modern protein identification and analysis relies largely on proteolytic in-gel digestion of proteins separated during polyacrylamide gel electrophoresis (PAGE) followed by mass spectrometric (MS) measurement of the extracted peptides. Sodium dodecyl sulfate (SDS) is routinely used in nonnative PAGE. However, SDS can interfere with MS. We report the use of an acid-labile surfactant (ALS-I) in place of SDS. ALSI is a long chain derivative of 1,3-dioxolane sodium propyloxy sulfate and has similar denaturing and electrophoretic properties as SDS, but it decomposes at low pH and enhances MS detection of proteins. PMID:19498958

  8. Gel for simultaneous chemical imaging of anionic and cationic solutes using diffusive gradients in thin films.

    PubMed

    Kreuzeder, Andreas; Santner, Jakob; Prohaska, Thomas; Wenzel, Walter W

    2013-12-17

    We report on a novel gel based on diffusive gradients in thin films (DGT) for the simultaneous measurement of cations and anions and its suitability for high resolution chemical imaging by using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The new high resolution mixed binding gel (HR-MBG) is based on zirconium-hydroxide and suspended particulate reagent-iminodiacetate (SPR-IDA) as resin materials which are embedded in an ether-based urethane polymer hydrogel. The use of this polymer hydrogel material allows the production of ultrathin, highly stable and tear-proof resin gel layers with superior handling properties compared to existing ultrathin polyacrylamide gels. The gel was characterized regarding its uptake kinetics, the anion and cation capacities, and the effects of pH, ionic strength, and aging on the performance of the HR-MBG. Our results demonstrate the capability of this novel gel for concomitant sampling of anions and cations. The suitability of this new gel type for DGT chemical imaging at submm spatial resolution in soils using LA-ICPMS is shown. 2D images of P, As, Co, Cu, Mn, and Zn distributions around roots of Zea mays L. demonstrate the new opportunities offered by the HR-MBG for high-resolution mapping of solute dynamics in soil and sediment hotspots, such as the rhizosphere, by simultaneous observation of anionic and cationic solute species. PMID:24256092

  9. Gel for Simultaneous Chemical Imaging of Anionic and Cationic Solutes Using Diffusive Gradients in Thin Films

    PubMed Central

    2013-01-01

    We report on a novel gel based on diffusive gradients in thin films (DGT) for the simultaneous measurement of cations and anions and its suitability for high resolution chemical imaging by using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The new high resolution mixed binding gel (HR-MBG) is based on zirconium-hydroxide and suspended particulate reagent-iminodiacetate (SPR-IDA) as resin materials which are embedded in an ether-based urethane polymer hydrogel. The use of this polymer hydrogel material allows the production of ultrathin, highly stable and tear-proof resin gel layers with superior handling properties compared to existing ultrathin polyacrylamide gels. The gel was characterized regarding its uptake kinetics, the anion and cation capacities, and the effects of pH, ionic strength, and aging on the performance of the HR-MBG. Our results demonstrate the capability of this novel gel for concomitant sampling of anions and cations. The suitability of this new gel type for DGT chemical imaging at submm spatial resolution in soils using LA-ICPMS is shown. 2D images of P, As, Co, Cu, Mn, and Zn distributions around roots of Zea mays L. demonstrate the new opportunities offered by the HR-MBG for high-resolution mapping of solute dynamics in soil and sediment hotspots, such as the rhizosphere, by simultaneous observation of anionic and cationic solute species. PMID:24256092

  10. "Out-gel" tryptic digestion procedure for chemical cross-linking studies with mass spectrometric detection.

    PubMed

    Petrotchenko, Evgeniy V; Serpa, Jason J; Cabecinha, Ashley N; Lesperance, Mary; Borchers, Christoph H

    2014-02-01

    SDS-PAGE is one of the most powerful protein separation techniques, and in-gel digestion is the leading method for converting proteins separated by SDS-PAGE into peptides suitable for mass spectrometry-based proteomic studies. In in-gel digestion, proteins are digested within the gel matrix, and the resulting peptides are extracted into an appropriate buffer. Transfer of the digested peptides to the liquid phase for subsequent mass spectrometric analysis, however, may be hampered by peptide-specific characteristics, including size, shape, poor solubility, adsorption to the polyacrylamide, and-in the case of cross-linking applications-by the branched structure of the peptides produced. This can be a limitation in cross-linking studies where efficient recoveries of the cross-linked peptides are critical. To overcome this limitation, we have developed a modification to the standard in-gel digestion procedure for SDS-PAGE-separated cross-linked proteins, based on older passive diffusion methods. By omitting the gel staining and gel fixation steps, intact proteins or cross-linked protein complexes can move through the gel and into the buffer solution. Digestion of the entire protein in the buffer outside the gel increases the probability that most of the proteolytic peptides produced will be present in the final digest solution. The resulting peptide mixture is then freed of SDS and concentrated using SCX (strong cation exchange) zip-tips and analyzed by mass spectrometry. For standard protein identification studies and the recovery of noncross-linked peptides, the in-gel procedure outperformed the out-gel procedure, but for cross-linking studies with enrichable cross-linkers (such as CBDPS), the standard out-gel procedure allowed the recoveries of cross-links not recovered via the in-gel method. Labeling experiments showed that, with an enrichable cross-linker, 93% of the cross-links showed better or equal recoveries with the out-gel procedure, as compared to the in-gel procedure. It should be noted that this method is not designed to replace in-gel digestion for most proteomics applications. However, by using the out-gel method, we were able to detect twice as many interprotein CBDPS cross-links from the histone H2A/H2B complex as were found in the in-gel digested sample. PMID:24354799

  11. Two-dimensional gel electrophoresis image registration using block-matching techniques and deformation models.

    PubMed

    Rodriguez, Alvaro; Fernandez-Lozano, Carlos; Dorado, Julian; Rabuñal, Juan R

    2014-06-01

    Block-matching techniques have been widely used in the task of estimating displacement in medical images, and they represent the best approach in scenes with deformable structures such as tissues, fluids, and gels. In this article, a new iterative block-matching technique-based on successive deformation, search, fitting, filtering, and interpolation stages-is proposed to measure elastic displacements in two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) images. The proposed technique uses different deformation models in the task of correlating proteins in real 2D electrophoresis gel images, obtaining an accuracy of 96.6% and improving the results obtained with other techniques. This technique represents a general solution, being easy to adapt to different 2D deformable cases and providing an experimental reference for block-matching algorithms. PMID:24613260

  12. Problems in sampling the Native American and Alaska Native populations

    Microsoft Academic Search

    EUGENE P. ERICKSEN

    1997-01-01

    Selecting a scientific national sample of Native Americans and Alaska Natives is difficult for at least four reasons: (1) they are a small proportion of the total population, (2) they are not so segregated that geographic oversampling can reach most of the population, (3) criteria for deciding who is a member of the Native American and Alaska Native population are

  13. Conformational transition of native and modified gellan.

    PubMed

    Mazen, F; Milas, M; Rinaudo, M

    1999-11-01

    This paper concerns the characterisation of native gellan by differential scanning calorimetry (DSC) and rheology. The stability of the double helix is characterised by Tm and the enthalpy of conformational change. The role of the external salt concentration is investigated; it is shown that Tm is only slightly modified. At ambient temperature, in 10(-2) M NaCl, native gellan behaves as a loose gel (G' > G''). This behaviour disappears when temperature is larger than 60 degrees C. The comparison with deacylated gellan (commercial sample) shows that the position of conformational transition is much more influenced by the salt concentration; the helical structure is less stable and the conformational transition presents a hysteresis between heating and cooling runs when the external salt concentration increases. The rheological behaviour is that corresponding to a solution (G' < G'') at ambient temperature and in 10(-2) M NaCl. When the salt excess increases, then a stronger gel is formed. The differences between the two types of samples are clearly established as well as the relations between the conformation and the rheology of the systems. PMID:10517517

  14. Natively probabilistic computation

    E-print Network

    Mansinghka, Vikash Kumar

    2009-01-01

    I introduce a new set of natively probabilistic computing abstractions, including probabilistic generalizations of Boolean circuits, backtracking search and pure Lisp. I show how these tools let one compactly specify ...

  15. Hypericum drummondii (Native) 2 

    E-print Network

    Hugh D. Wilson

    2011-08-10

    Purpose: The purpose of this research was to quantify the number of blood vessels and nerves and mineral apposition rate (MAR) in native bone and compare it to the regenerate bone produced by bone transport distraction osteogenesis (BTDO...

  16. Native Knowledge in the Americas.

    ERIC Educational Resources Information Center

    Kidwell, Clara Sue

    1985-01-01

    Native American science is defined as activities of native peoples of the New World in observing physical phenomena and attempting to explain and control them. Problems in studying native science, ethnoscience and native science, archaeostronomy and ethnoastronomy, ethnobotany, agriculture, technology, and future directions are discussed. (JN)

  17. Periodic mesoporous silica gels

    SciTech Connect

    Anderson, M.T.; Martin, J.E.; Odinek, J.G. [and others

    1996-06-01

    We have synthesized monolithic particulate gels of periodic mesoporous silica by adding tetramethoxysilane to a homogeneous alkaline micellar precursor solution. The gels exhibit 5 characteristic length scales over 4 orders of magnitude: fractal domains larger than the particle size (>500 nm), particles that are {approximately}150 to 500 nm in diameter, interparticle pores that are on the order of the particle size, a feature in the gas adsorption measurements that indicates pores {approximately}10-50 nm, and periodic hexagonal arrays of {approximately}3 nm channels within each particle. The wet gel monoliths exhibit calculated densities as low as {approximately}0.02 g/cc; the dried and calcined gels have bulk densities that range from {approximately}0.3-0.5 g/cc. The materials possess large interparticle ({approximately}1.0-2.3 cc/g) and intraparticle ({approximately}0.6 cc/g) porosities.

  18. Microfluidics with Gel Emulsions

    NASA Astrophysics Data System (ADS)

    Priest, Craig; Surenjav, Enkhtuul; Herminghaus, Stephan; Seemann, Ralf

    2006-03-01

    Microfluidic processing is usually achieved using single phase liquids. Instead, we use monodisperse emulsions to compartment liquids within microchannel geometries. At low continuous phase volume fractions, droplets self-organize to form well-defined arrangements, analogous to foam. While it is well-known that confined geometries can induce rearrangement of foam compartments at the millimeter-scale, similar dynamics are also expected for gel emulsions. We have studied online generation, organization and manipulation of gel emulsions using a variety of microchannel geometries. ``Passive'' reorganization, based on fixed channel geometries, can be supplemented by ``active'' manipulation by incorporating a ferrofluid phase. A ferromagnetic phase facilitates reorganization of liquid compartments on demand using an electromagnetic trigger. Moreover, coalescence between adjacent compartments within a gel emulsion can be induced using electrical potential. Microfluidics using gel emulsions will be well-suited for combinatorial chemistry, DNA sequencing, drug screening and protein crystallizations.

  19. Ultrasensitive fluorescence-based detection of nascent proteins in gels.

    PubMed

    Gite, S; Mamaev, S; Olejnik, J; Rothschild, K

    2000-03-15

    The most common method of analysis of proteins synthesized in a cell-free translation system (e.g., nascent proteins) involves the use of radioactive amino acids such as [(35)S]methionine or [(14)C]leucine. We report a sensitive, nonisotopic, fluorescence-based method for the detection of nascent proteins directly in polyacrylamide gels. A fluorescent reporter group is incorporated at the N-terminus of nascent proteins using an Escherichia coli initiator tRNA(fmet) misaminoacylated with methionine modified at the alpha-amino group. In addition to the normal formyl group, we find that the protein translational machinery accepts BODIPY-FL, a relatively small fluorophore with a high fluorescent quantum yield, as an N-terminal modification. Under the optimal conditions, fluorescent bands from nanogram levels of in vitro-produced proteins could be detected directly in gels using a conventional UV-transilluminator. Higher sensitivity ( approximately 100-fold) could be obtained using a laser-based fluorescent gel scanner. The major advantages of this approach include elimination of radioactivity and the rapid detection of the protein bands immediately after electrophoresis without any downstream processing. The ability to rapidly synthesize nascent proteins containing an N-terminal tag facilitates many biotechnological applications including functional analysis of gene products, drug discovery, and mutation screening. PMID:10706791

  20. Crystallization from Gels

    NASA Astrophysics Data System (ADS)

    Narayana Kalkura, S.; Natarajan, Subramanian

    Among the various crystallization techniques, crystallization in gels has found wide applications in the fields of biomineralization and macromolecular crystallization in addition to crystallizing materials having nonlinear optical, ferroelectric, ferromagnetic, and other properties. Furthermore, by using this method it is possible to grow single crystals with very high perfection that are difficult to grow by other techniques. The gel method of crystallization provides an ideal technique to study crystal deposition diseases, which could lead to better understanding of their etiology. This chapter focuses on crystallization in gels of compounds that are responsible for crystal deposition diseases. The introduction is followed by a description of the various gels used, the mechanism of gelling, and the fascinating phenomenon of Liesegang ring formation, along with various gel growth techniques. The importance and scope of study on crystal deposition diseases and the need for crystal growth experiments using gel media are stressed. The various crystal deposition diseases, viz. (1) urolithiasis, (2) gout or arthritis, (3) cholelithiasis and atherosclerosis, and (4) pancreatitis and details regarding the constituents of the crystal deposits responsible for the pathological mineralization are discussed. Brief accounts of the theories of the formation of urinary stones and gallstones and the role of trace elements in urinary stone formation are also given. The crystallization in gels of (1) the urinary stone constituents, viz. calcium oxalate, calcium phosphates, uric acid, cystine, etc., (2) the constituents of the gallstones, viz. cholesterol, calcium carbonate, etc., (3) the major constituent of the pancreatic calculi, viz., calcium carbonate, and (4) cholic acid, a steroidal hormone are presented. The effect of various organic and inorganic ions, trace elements, and extracts from cereals, herbs, and fruits on the crystallization of major urinary stone and gallstone constituents are described. In addition, tables of gel-grown organic and inorganic crystals are provided.

  1. Fluorescent staining of gels.

    PubMed

    Buxbaum, Engelbert

    2012-01-01

    Certain transition metal complexes show intensive fluorescence when bound to proteins. They can be used to stain gels after electrophoresis with a sensitivity approaching that of silver staining, but in a much simpler and more reproducible procedure. Stains can be prepared easily and at a fraction of the cost of commercially available reagents.Hydrophobic dyes can be used to stain gels without fixing; they do not interfere with later blotting or electro-elution. PMID:22585519

  2. DGT/DET gel partition features of humic acid/metal species.

    PubMed

    Veeken, Pascal L R van der; Leeuwen, Herman P van

    2010-07-15

    Gel layer based sensors are increasingly employed for dynamic trace metal speciation analysis in aquatic and soil media, in which humic and fulvic acid species are generally known to be relevant. In DGT (diffusive gradient in thin film), polyacrylamide hydrogels are commonly used for the diffusive gel layer. Various effects of the presence of humic species on the amount of metal detected by DGT have been observed, but the role of the different metal/humic species is still unknown. Recently it was shown that in the absence of metal, humic acid accumulates significantly in the polyacrylamide hydrogel. Here we analyze the extent of this accumulation in the presence of cadmium under various conditions of ionic strength and total humic and fulvic acid concentrations. At millimolar ionic strength level, DET data show significant accumulation of cadmium(II) in the gel phase, on top of some Donnan enrichment. The results are essential for the interpretation of DGT/DET data on metals in the presence of humics, especially in freshwaters. PMID:20553040

  3. Native American Journalists Association

    NSDL National Science Digital Library

    The Native American Journalists Association (NAJA) is based on the campus of the University of Oklahoma in Norman, OK. NAJA was started in 1984 in order to improve the communications among Native people as well as between Native people and the public. Visitors can click on the "Resources" tab near the top of the page to view, among other things, links to "Job Opportunities", "Internships/Fellowships", and "Publications". Free downloadable versions of "The Reading Red Report" from 2002, 2003, and 2007 can be accessed in the "Publications" link. The 2007 Report gives the visitor the opportunity to see some of the research that NAJA has done on how Natives are depicted in the mainstream newspapers of areas with the highest population of Native peoples. The "Media Links" link, also under the "Resources" tab, has a wealth of information regarding media that would be helpful for any journalists or aspiring journalists. Some of the links include "Journalism Centers", "Journalism Libraries", "Job Sites", and "News Research". Under the "Programs" tab, there is a link to "Students" that has various resources for those pursuing scholarships, internships or finding student chapters of NAJA.

  4. Characterization of Network Structure of Polyacrylamide Based Hydrogels Prepared By Radiation Induced Polymerization

    SciTech Connect

    Mahmudi, Naim [State University of Tetovo, Faculty of Natural Science and Mathematics, 1200 Tetovo (Macedonia, The Former Yugoslav Republic of); Sen, Murat; Gueven, Olgun [Hacettepe University, Department of Chemistry, Polymer Chemistry Division, 06532, Beytepe, Ankara (Turkey); Rendevski, Stojan [Institute of Physics, Faculty of Natural Science and Mathematics, University 'Ss Cyril and Methodius', Skopje (Macedonia, The Former Yugoslav Republic of)

    2007-04-23

    In this study network structure of polyacrylamide based hydrogels prepared by radiation induced polymerization has been investigated. Polyacrylamide based hydrogels in the rod form were prepared by copolymerization of acrylamide(AAm) with hydroxyl ethyl methacrylate(HEMA) and methyl acrylamide(MAAm) in the presence of cross-linking agent and water by gamma rays at ambient temperature. Molecular weight between cross-links and effective cross-link density of hydrogels were calculated from swelling as well as shear modulus data obtained from compression tests. The results have shown that simple compression analyses can be used for the determination of effective cross-link density of hydrogels without any need to some polymer-solvent based parameters as in the case of swelling based determinations. Diffusion of water into hydrogels was examined by analyzing water absorption kinetics and the effect of network, structure on the diffusion type and coefficient was discussed.

  5. Electrical properties of nano-silver\\/polyacrylamide\\/ethylene vinyl acetate composite

    Microsoft Academic Search

    Man Xu; Jun-qiang Feng; Xiao-long Cao

    2008-01-01

    Nano-Ag particles\\/polyacrylamide (PAM) composites were synthesized by ? irradiation method and then blended with ethylene vinyl acetate (EVA). Dielectric behaviors of the Ag\\/PAM\\/EVA composites\\u000a are investigated as a function of both the concentration and size of Ag particles. When concentration of the Ag fillers is\\u000a rarely low, dielectric anomalies were first observed in contrast to the traditional percolation theory. As

  6. Effect of Varying Polyacrylamide Molecular Weight on Tertiary Oil Recovery From Porous Media of Varying Permeability

    Microsoft Academic Search

    J. T. Ball; M. J. Pitts

    1984-01-01

    Three different molecular weight emulsion polyacrylamides (PAA) have been tested for their ability to recover oil from a multi-permeability Berea core system. Injection of a 6.5 x 10⁶, 17 x 10⁶, and 36 x 10⁶ molecular weight PAA resulted in oil recovery from the multiple permeability core systems of 53.4, 63.7, and 57.2 percent of the waterflood residual oil, respectively.

  7. The effects of some electrolytes on flocculation with a cationic polyacrylamide

    Microsoft Academic Search

    R. H. Pelton; L. H. Allen

    1983-01-01

    The effects of sodium chloride, sodium sulfate, and alum (aluminum sulfate) on the performance of a cationic polyacrylamide flocculant in a papermaking suspension consisting of bleached (hardwood: softwood, 50:50) kraft wood-pulp fibres and anatase (TiO2) were investigated. Sodium chloride and sodium sulfate, 1×10-5 to 1×10-2 M, in the presence of polymer, caused negligible changes in the electrophoretic mobility of the

  8. Depositional seals in polyacrylamide-amended soils of varying clay mineralogy and texture

    Microsoft Academic Search

    Ajay K. Bhardwaj; Richard A. McLaughlin; Guy J. Levy

    2010-01-01

    Purpose  Depositional seals, formed when turbid waters infiltrate into soils, lead to a reduction in soil hydraulic conductivity (HC)\\u000a and enhance runoff and soil erosion. Since clay size particles constitute a dominant proportion of depositional seals, soil\\u000a texture and clay mineralogy play a significant role in determining the seal’s hydraulic characteristics. Presence of high\\u000a molecular weight anionic polyacrylamide (PAM) in suspension

  9. Investigations on synthesis and characterization of functionalized graphene sheets-polyacrylamide composites

    Microsoft Academic Search

    Ratnesh Pandey; Kalpana Awasthi; R. S. Tiwari; O. N. Srivastava

    2010-01-01

    The functionalized graphene sheets (FGS)-polyacrylamide (PAM) composite films\\u000ahave been prepared by solution cast technique. The FGS have been synthesized by\\u000athermal exfoliation of graphite oxide. Several composites with different weight\\u000a% (between 0 to 25 wt %) of FGS loading in PAM have been prepared and\\u000acharacterized by XRD, SEM, TEM and FTIR spectroscopy. FTIR analysis revealed\\u000athe existence

  10. Silk fibroin\\/polyacrylamide semi-interpenetrating network hydrogels for controlled drug release

    Microsoft Academic Search

    Biman B. Mandal; Sonia Kapoor; Subhas C. Kundu

    2009-01-01

    The present study describes a semi-interpenetrating network hydrogel fabricated using silk fibroin\\/polyacrylamide for controlled drug delivery applications. Hydrogels were synthesized using varied ratios of silk fibroin\\/acrylamide mixtures crosslinked by N,N?-Methylenebisacrylamide. Fourier-Transform Infrared analysis was performed suggesting ? sheet transition of silk fibroin with hydrogels. Scanning electron microscopy revealed microporous surface with maximum pore size of 50±11?m. Rheological properties along with

  11. Adsorption of Hg 2+ from aqueous solution onto polyacrylamide\\/attapulgite

    Microsoft Academic Search

    Yijiang Zhao; Yan Chen; Meisheng Li; Shouyong Zhou; Ailian Xue; Weihong Xing

    2009-01-01

    Polyacrylamide\\/attapulgite (PAM\\/ATP) was prepared by the solution polymerization of acrylamide (AM) onto ?-methacryloxypropyl trimethoxy silane (KH-570)-modified attapulgite (ATP). PAM\\/ATP was characterized using Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of contact time, adsorbent dosage, and pH of the initial solution on the adsorption capacities for Hg2+ were investigated. The adsorption process was rapid; 88% of adsorption

  12. Competitive adsorption of Hg 2+, Pb 2+ and Co 2+ ions on polyacrylamide\\/attapulgite

    Microsoft Academic Search

    Shouyong Zhou; Ailian Xue; Yijiang Zhao; Qiwei Wang; Yan Chen; Meisheng Li; Weihong Xing

    2011-01-01

    In the present study, the competitive adsorption characteristics of binary and ternary heavy metal ions Hg2+, Pb2+ and Co2+ on polyacrylamide\\/attapulgite (PAM\\/ATP) were investigated in batch systems. PAM\\/ATP was prepared by the solution polymerization of acrylamide (AM) onto ?-methacryloxypropyl trimethoxy silane (KH-570) modified attapulgite (ATP) and characterized by the technique of X-ray photoelectron spectroscopy (XPS). Equilibrium and kinetic adsorption data

  13. Native American Manuscript Collections

    NSDL National Science Digital Library

    Based at the University of Oklahoma's Western History Collection, the Native American Manuscript Collections contain over 200 documents relating to Native Americans in Oklahoma, Indian Territory, and the southwestern United States. On the homepage, visitors can browse the manuscripts, which are listed by nation. The Creek Nation area is quite fascinating, as there are over 35 documents here including handwritten journals, trading company ledgers, and letters from farmers like James M. Latty and other Creeks. After this introduction, visitors can browse around through the works of other nations, including the Cherokee, Choctaw, and Chickasaw.

  14. Growth of human renal cortical tissue on collagen gel

    Microsoft Academic Search

    Sung-Goo Chang; Károly Tóth; Jennifer D. Black; Harry K. Slocum; Scott D. Perrapato; Robert P. Huben; Youcef M. Rustum

    1992-01-01

    Summary  A model system for 3-dimensional “native-state” culture of tissues on collagen gels (Proc. Natl. Acad. Sci. USA 86:2013–2017;\\u000a 1989) has been applied in this study to histologically normal human renal cortical tissue from 11 patients undergoing nephrectomy\\u000a for renal cell carcinoma elsewhere in the kidney. Microbial contamination occurred in 12\\/90 cultures, the rest (78) were studied\\u000a by visual inspection, histology,

  15. Ultrasensitive staining-free protein detection after PAA gel electrophoresis using deep UV fluorescence.

    PubMed

    Riaplov, Eugene; Li, Qiang; Seeger, Stefan

    2007-01-01

    We present the observation of separated protein bands after polyacrylamide (PAA) gel electrophoresis based on the staining-free detection of their ultra violet (UV)-induced fluorescence employing deep UV confocal fluorescence microscopy. Mixtures of the three biological compounds beta-Galactosidase (from Escherichia coli), apo-Transferrin (bovine) and bovine serum albumin (BSA) have been separated and a staining free detection limit below 80 pg (7.0 x 10(8) molecules) per band has been achieved. This corresponds to approximately 270 molecules in the detection volume for confocal microscopy. PMID:17897099

  16. NATIVE HEALTH DATABASES: NATIVE HEALTH HISTORY DATABASE (NHHD)

    EPA Science Inventory

    The Native Health Databases contain bibliographic information and abstracts of health-related articles, reports, surveys, and other resource documents pertaining to the health and health care of American Indians, Alaska Natives, and Canadian First Nations. The databases provide i...

  17. NATIVE HEALTH DATABASES: NATIVE HEALTH RESEARCH DATABASE (NHRD)

    EPA Science Inventory

    The Native Health Databases contain bibliographic information and abstracts of health-related articles, reports, surveys, and other resource documents pertaining to the health and health care of American Indians, Alaska Natives, and Canadian First Nations. The databases provide i...

  18. A model of ideal elastomeric gels for polyelectrolyte gels

    E-print Network

    Suo, Zhigang

    a polyacrylamide-co-acrylic acid hydrogel as a model material system. A comparison between mixing and ion osmosis shows that the mixing osmosis is larger than the ion osmosis for small swelling ratios, while the ion osmosis dominates for large swelling ratios. We show further that the non-Gaussian chain effect becomes

  19. Enzymatic assessment of cholesterol on electrophoresis gels for estimating HDL size distribution and plasma concentrations of HDL subclasses[S

    PubMed Central

    Toledo-Ibelles, Paola; García-Sánchez, Cynthia; Ávila-Vazzini, Nydia; Carreón-Torres, Elizabeth; Posadas-Romero, Carlos; Vargas-Alarcón, Gilberto; Pérez-Méndez, Oscar

    2010-01-01

    The aim of this study was to develop an enzymatic cholesterol staining method to determine HDL subclasses in a polyacrylamide gradient gel electrophoresis, which further allows staining by protein in the same electrophoresis lane. HDLs from 120 healthy individuals were separated through nondenaturing PAGE. HDLs were stained for cholesterol using an enzymatic semisolid mixture. Once the gels were unstained, they were stained again for proteins with Coomassie blue. The proportions of HDL subclasses were determined by densitometry. HDL subclasses were transformed to concentrations using as reference HDL-cholesterol plasma levels. This method is comparable in linearity and reproducibility to Coomassie blue staining, although it provides quantitative data. As expected, HDL size distribution shifted toward larger particles when determined by cholesterol as compared with protein. With this method, we observed different proportions of HDL subclasses between men and women as compared with Coomassie blue staining. We described a method to determine HDL size distribution by enzymatic cholesterol staining on polyacrylamide gels. The method allows the quantification of the cholesterol plasma concentration of each HDL subclass with the possibility to further stain the protein in the same sample. The combination of HDL staining by cholesterol and protein on electrophoresis gels provides information that may have clinical relevance. PMID:20097938

  20. Symbolicity Among Native Americans.

    ERIC Educational Resources Information Center

    Hill, L. Brooks; Lujan, Philip

    Within the framework of "symbolicity" and "nativistic movement" the paper presents a "reasonably balanced and illustrative" examination of selected negative and positive trends in Native American symbolicity. Symbolicity is defined as the state, condition, and tendency of people to organize their perceptions and experience into symbols and symbol…

  1. Native American Resource Book.

    ERIC Educational Resources Information Center

    Spears, Carl D., Comp.; And Others

    Focusing on the Southeastern American Indian cultures, this Native American resource guide is designed for use in the elementary and secondary schools of the East Baton Rouge Parish and is a product of a 1975 Indian Advisory Committee composed of Indian parents, teachers, and staff members. Objectives of these materials require the Indian student,…

  2. Native American Case Studies

    NSDL National Science Digital Library

    The Evergreen State College

    The Native American Case Studies collection includes more than 80 original, research-based teaching cases focusing on contemporary issues in Indian Country. Teaching notes accompany each case. These can be downloaded and used at no cost. Additional website resources include information on teaching with cases and assessment. Guidelines for submitting cases are also available.

  3. Native American Literature.

    ERIC Educational Resources Information Center

    Porter, C. Fayne; And Others

    Designed to accommodate a semester course in Native American Literature for secondary students, this teacher's guide includes a general introduction, a statement of the philosophy and goals upon which it is predicated, a nine-week block on post-Columbian literature, a nine-week block on oral literature, separate appendices for each block, a…

  4. Native Americans in Utah

    NSDL National Science Digital Library

    Albion Middle School Library--Mrs. Bates

    2006-10-10

    This activity will help you learn about some of the early Native American inhabitants of Utah. Look at the following websites and see if you can find some information about one of the following groups of Native Americans in Utah. History of Utah Tribes Goshute Goshute Indians Utah History To Go: Goshute Indians Goshute Indian Reservation Utah History To Go: The Utes, Paiutes, and Goshutes Navajo People of the Colorado Plateau: Navajo (Dine) History of the Navajo Indians of Utah Navajo Navajo Indians Paiute Paiute Indians of Utah Paiute Native American Desert Peoples: The Paiute People Paiute Indians of Utah Utah History To Go--Piaute Indians Utah History To Go: The Utes, Paiutes, and Goshutes Shoshone Shoshone History of the Shoshone Indians Shoshoni Lewis and Clark: Native Americans--Shoshone Indians Ute Utah History To Go: Ute Indians People of the Colorado Plateau: The Ute Indians Story of the Ute Tribe Northern Ute Indian History Utah History To Go: The Utes, Paiutes, and Goshutes ...

  5. Rebuilding Native American Communities

    ERIC Educational Resources Information Center

    Coyhis, Don; Simonelli, Richard

    2005-01-01

    The Wellbriety Movement in Native American communities draws on the wisdom and participation of traditional elders. Beginning with a basic community teaching called the Four Laws of Change and the Healing Forest Model, the Wellbriety Movement blends Medicine Wheel knowledge with the 12 Steps of Alcoholics Anonymous to provide culture-specific…

  6. Native Westslope Cutthroat Trout

    USGS Multimedia Gallery

    Native westslope cutthroat trout swim in the north fork of the Flathead River in northwestern Montana. The region is recognized as a range-wide stronghold for genetically pure westslope cutthroat trout. However, rainbow trout invasion and hybridization threatens these p...

  7. Native Westslope Cutthroat Trout

    USGS Multimedia Gallery

    Native westslope cutthroat trout swim in the north fork of the Flathead River in northwestern Montana. This region is recognized as a range-wide stronghold for genetically pure westslope cutthroat trout. However, rainbow trout invasion and hybridization threatens these ...

  8. Two-Dimensional Gel Electrophoresis of Acid-extractable Nuclear Proteins of Regenerating and Thioacetamide-treated Rat Liver, Morris 9618A Hepatoma, and Walker 256 Carcinosarcoma1

    Microsoft Academic Search

    Lynn C. Yeoman; Charles W. Taylor; Harris Busch

    SUMMARY The acid-soluble nuclear proteins of regenerating and thi- oacetamide-treated rat livers as well as the Morris 9618A hepatoma and the Walker 256 carcinosarcoma were ex tracted from citric acid-isolated nuclei with 0.4 N H2SO4. The nuclear extracts were analyzed by two-dimensional polyacrylamide gel electrophoresis. Although most of the protein spots were common to the livers and tumors stud ied,

  9. Native Peoples-Native Homelands Climate Change Workshop: Lessons Learned

    NASA Astrophysics Data System (ADS)

    Maynard, N. G.

    2003-12-01

    The Native Peoples-Native Homelands Climate Change Workshop was held on October 28 through November 01, 1998, as part of a series of workshops being held around the U.S. to improve the understanding of the potential consequences of climate variability and change for the Nation. This workshop was specifically designed by Native Peoples to examine the impacts of climate change and extreme weather variability on Native Peoples and Native Homelands from an indigenous cultural and spiritual perspective and to develop recommendations as well as identify potential response actions. The workshop brought together interested Native Peoples, representatives of Tribal governments, traditional elders, Tribal leaders, natural resource managers, Tribal College faculty and students, and climate scientists from government agencies and universities. It is clear that Tribal colleges and universities play a unique and critical role in the success of these emerging partnerships for decision-making in addition to the important education function for both Native and non-Native communities such as serving as a culturally- appropriate vehicle for access, analysis, control, and protection of indigenous cultural and intellectual property. During the discussions between scientists and policy-makers from both Native and non-Native communities, a number of important lessons emerged which are key to building more effective partnerships between Native and non-Native communities for collaboration and decision-making for a more sustainable future. This talk summarizes the key issues, recommendations, and lessons learned during this workshop.

  10. Gel Electrophoresis of Dyes

    NSDL National Science Digital Library

    Janice Stephens

    2011-01-01

    In this experiment related to plant biotechnology, learners discover how to prepare and load an electrophoresis gel. They will then run the gels in an electrophoresis system to separate several dyes that are of different molecular sizes and carry different charges. This technique is fundamental to many of the procedures used in biotechnology. This lesson guide includes background information for the educator, safety precautions, and questions with answers for learners. For safety reasons, adult supervision is recommended. Modifications for use with younger learners are described in a related PDF (see related resource).

  11. Native Americans' Interest in Horticulture.

    ERIC Educational Resources Information Center

    Meyer, Mary Hockenberry

    1999-01-01

    Focus groups arranged by local Native American Master Gardeners on two Minnesota reservations determined community interest in extension-horticulture programs. Topics of interest included food preservation and historical Native-American uses of plants. (SK)

  12. Rheology of Active Gels

    NASA Astrophysics Data System (ADS)

    Chen, Daniel

    2015-03-01

    Active networks drive a diverse range of critical processes ranging from motility to division in living cells, yet a full picture of their rheological capabilities in non-cellular contexts is still emerging, e.g., How does the rheological response of a network capable of remodeling under internally-generated stresses differ from that of a passive biopolymer network? In order to address this and other basic questions, we have engineered an active gel composed of microtubules, bidirectional kinesin motors, and molecular depletant that self-organizes into a highly dynamic network of active bundles. The network continually remodels itself under ATP-tunable cycles of extension, buckling, fracturing, and self-healing. Using confocal rheometry we have simultaneously characterized the network's linear and non-linear rheological responses to shear deformation along with its dynamic morphology. We find several surprising and unique material properties for these active gels; most notably, rheological cloaking, the ability of the active gel to drive large-scale fluid mixing over several orders of flow magnitude while maintaining an invariant, solid-like rheological profile and spontaneous flow under confinement, the ability to exert micro-Newton forces to drive persistent directed motion of the rheometer tool. Taken together, these results and others to be discussed highlight the rich stress-structure-dynamics relationships in this class of biologically-derived active gels.

  13. Pouring an Agarose Gel

    NSDL National Science Digital Library

    Hinkley, Craig

    This video from CUNY Kingsborough Community College shows how to pour an Agarose Gel. The video describes the process step by step and would be easy to replicate in a laboratory setting. Running time for the video is 2:13.

  14. Running an Agarose Gel

    NSDL National Science Digital Library

    Hinkley, Craig

    This video from CUNY Kingsborough Community College shows the process of running an agarose gel. The video describes the process step by step and would be easy to replicate in a laboratory setting. Running time for the video is 2:52.

  15. A simple and accurate method for generating co-dominant markers: an application of conformation-sensitive gel electrophoresis to linkage analysis in the silkworm.

    PubMed

    Yasukochi, Y

    1999-06-01

    A simple and sensitive method for linkage analysis is described, which is based on conformation-sensitive gel electrophoresis (CSGE). Using urea-containing agarose gels or a commercially available polyacrylamide-derived matrix, 13 polymorphic markers were newly identified for known genes of the silkworm, Bombyx mori, which had been scored as monomorphic by PCR-RFLP analysis. This method for detecting polymorphisms is quite sensitive, and can be performed with inexpensive reagents and apparatus that is available in most molecular biology laboratories. PMID:10394917

  16. 76 FR 22413 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ...to Afognak Native Corporation, Successor in Interest to Port Lions Native Corporation. The decision approves the surface estate...to Afognak Native Corporation, Successor in Interest to Port Lions Native Corporation. The lands are in the vicinity of...

  17. Comparative studies on the analysis of glycoproteins and lipopolysaccharides by the gel-based microchip and SDS-PAGE.

    PubMed

    Hsieh, Jung-Feng; Chen, Shui-Tein

    2007-01-01

    In order to determine time efficiency between the gel-based microchip (LabChip) and traditional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), glycoproteins and lipopolysaccharides were analyzed in this study. After 90 min of gel electrophoresis, glycoproteins (bovine serum albumin, lysozyme, ovalbumin, and apo-transferrin) and fluorescent lipopolysaccharides (LPS-O and LPS-S) under reducing conditions could be analyzed by SDS-PAGE, and it would take (including imaging and analyzing) more than 3 h. The same sample could also be assayed on a Bioanalyzer in combination with the LabChip, and it would only need 30 min from start to finish. The assay software automatically calculated the size and concentration of each separated peak and displayed the results in real time, thus eliminating time-consuming procedures such as imaging and analyzing. Compared to the traditional reducing SDS-PAGE, LabChip has a faster turnaround time. PMID:19693351

  18. Vacuum Sealing Drainage in the Treatment of Migrated Polyacrylamide Hydrogel after Breast Augmentation: A Case Report

    PubMed Central

    Wu, Jinfang; Zhang, Xudong; Zhao, Qiming; Mao, Dongsheng; Lu, Xin

    2014-01-01

    Summary Background Polyacrylamide hydrogel (PAAG) injection for breast augmentation can result in a variety of complications, including implant migration. The migrated PAAG can become colonized by pathogens, resulting in secondary infections which can be extremely difficult to treat. Case Report We report the case of a 43-year-old female patient who underwent PAAG injection for breast augmentation. Implant migration was diagnosed 8 years after the initial injection. Conclusion Here, we report the first use of vacuum sealing drainage as a convenient and effective alternative to manage the complications of extensive PAAG migration after breast augmentation. PMID:25404887

  19. Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms.

    PubMed Central

    Orita, M; Iwahana, H; Kanazawa, H; Hayashi, K; Sekiya, T

    1989-01-01

    We developed mobility shift analysis of single-stranded DNAs on neutral polyacrylamide gel electrophoresis to detect DNA polymorphisms. This method follows digestion of genomic DNA with restriction endonucleases, denaturation in alkaline solution, and electrophoresis on a neutral polyacrylamide gel. After transfer to a nylon membrane, the mobility shift due to a nucleotide substitution of a single-stranded DNA fragment could be detected by hybridization with a nick-translated DNA fragment or more clearly with RNA copies synthesized on each strand of the DNA fragment as probes. As the mobility shift caused by nucleotide substitutions might be due to a conformational change of single-stranded DNAs, we designate the features of single-stranded DNAs as single-strand conformation polymorphisms (SSCPs). Like restriction fragment length polymorphisms (RFLPs), SSCPs were found to be allelic variants of true Mendelian traits, and therefore they should be useful genetic markers. Moreover, SSCP analysis has the advantage over RFLP analysis that it can detect DNA polymorphisms and point mutations at a variety of positions in DNA fragments. Since DNA polymorphisms have been estimated to occur every few hundred nucleotides in the human genome, SSCPs may provide many genetic markers. Images PMID:2565038

  20. Comparison and Suitability of Gel Matrix for Entrapping Higher Content of Enzymes for Commercial Applications

    PubMed Central

    Mahajan, R.; Gupta, V. K; Sharma, J.

    2010-01-01

    To check the suitability of enzyme entrapped beads for use in pharmaceutical industry, amylase enzyme was entrapped in agar/agarose, polyacrylamide gels and calcium alginate beads. Sodium alginate of 1% concentration was found to be best with respect to immobilization efficiency and calcium alginate beads so obtained were not much susceptible to breakage. When sodium alginate- amylase mixture was added from a height of about 20-30 cm. into CaCl2 solution, size of beads was large at higher alginate concentration due to the increase in the size of droplet formation before entering into CaCl2 solution. Enzyme entrapped polyacrylamide and agar/agarose gels were fragile and could not withstand repeated use whereas enzyme entrapped in large calcium alginate beads was used successfully for 50 cycles for the conversion of starch into product without much damage to the beads under stirring conditions. Amylase preparation was also mixed with urease, lysozyme and coimmobilized in large sized calcium alginate beads. These beads were used for 10 repeated cycles to check the conversion of substrates into their products by their respective enzymes and we concluded that an enzyme or mixture of two or three enzymes can be immobilized in the same large sized calcium alginate beads. This will save the additional cost of bioreactor, manpower, maintenance conditions required for the conversion of one drug into another using enzyme/s entrapped in large sized beads. PMID:20838527

  1. MAGIC Gel Dosimetry

    NASA Astrophysics Data System (ADS)

    Mifflin, Rachel; Shahnazi, Kambiz; Jesseph, Rick

    2008-10-01

    Proton therapy has proven a very successful tool in treating certain tumors, but a three dimensional view of this fact has not yet been clearly demonstrated. In this experiment we have used MAGIC (Methacrylic and Ascorbic Acid in Gelatin Initiated by Copper) gel to represent brain tissue and gone through normal treatment planning for an Acoustic Neuroma to show the three dimensional dose distributions associated with such a tumor.

  2. Development of Polymer Gel Systems to Improve Volumetric Sweep and Reduce Producing Water/Oil Ratios

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Feiyan Chen

    2005-12-31

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of a 42-month research program that focused on the understanding of gelation chemistry and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work was conducted on a widely applied system in the field, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. Pre-gel aggregates form and grow as reactions between chromium acetate and polyacrylamide proceed. A rate equation that describes the reaction between chromium acetate and polymer molecules was regressed from experimental data. A mathematical model that describes the crosslinking reaction between two polymer molecules as a function of time was derived. The model was based on probability concepts and provides molecular-weight averages and molecular-weight distributions of the pre-gel aggregates as a function of time and initial system conditions. Average molecular weights of pre-gel aggregates were measured as a function of time and were comparable to model simulations. Experimental methods to determine molecular weight distributions of pre-gel aggregates were unsuccessful. Dissolution of carbonate minerals during the injection of gelants causes the pH of the gelant to increase. Chromium precipitates from solution at the higher pH values robbing the gelant of crosslinker. Experimental data on the transport of chromium acetate solutions through dolomite cores were obtained. A mathematical model that describes the transport of brine and chromium acetate solutions through rocks containing carbonate minerals was used to simulate the experimental results and data from literature. Gel treatments usually reduce the permeability to water to a greater extent than the permeability to oil is reduced. This phenomenon is referred to as disproportionate permeability reduction (DPR). Flow experiments were conducted in sandpacks to determine the effect of polymer and chromium concentrations on DPR. All gels studied reduced the permeability to water by a greater factor than the factor by which the oil permeability was reduced. Greater DPR was observed as the concentrations of polymer and chromium were increased. A conceptual model of the mechanisms responsible for DPR is presented. Primary features of the model are (1) the development of flow channels through the gel by dehydration and displacement of the gel and by re-connection of pre-treatment, residual oil volume and (2) high flow resistance in the channels during water flow is caused by significant saturations of oil remaining in the channels. A similar study of DPR was conducted in Berea sandstone cores. Both oil and water permeabilities were reduced by much smaller factors in Berea sandstone cores than in similar treatments in sandpacks. Poor maturation of the gelant in the Berea rock was thought to be caused by fluid-rock interactions that interfered with the gelation process.

  3. NativeTech: Native American Technology and Art

    NSDL National Science Digital Library

    Prindle, Tara.

    NativeTech, "an educational web site that covers topics of Native American technology and emphasizes the Eastern Woodlands region," is the brainchild of Tara Prindle of the Department of Anthropology at the University of Connecticut. This site is dedicated to disconnecting the term "Primitive" from perceptions of Native American technology and art. Categories include Essays & Articles, Poetry & Stories, Beadwork, Birds & Feathers, Clay & Pottery, Leather & Clothes, Metalwork, Plants & Trees, Porcupine Quills, Stonework & Tools, and Weaving & Cordage. The site provides in-depth information about many crafts from sewing moccasins to preparing clay to specifics on pine needle basketry. For quality, detail and on-target graphics, NativeTech deserves high marks.

  4. Native American geometry

    NSDL National Science Digital Library

    2007-12-12

    This website focuses on Native American use of the physical, proportional geometry that originates from the simple circle. Aimed at 4th to 9th grade teachers, the site is divided into four sections: foundations, anthropology, designs, and education. It was selected by Britannica.com, February 2000, as a best Internet site. Other keywords: geometric shapes, geometric constructions, proportional geometry, proportional constants, polygons, hexagons, equilateral triangles, dodecagons, squares, octagons, connect the dot, art, square roots, irrational numbers, non-random geometry. (Includes about 25 relevant website links and 50 published references)

  5. Structure and kinetics of chemically cross-linked protein gels from small-angle X-ray scattering

    E-print Network

    Kaieda, Shuji; Halle, Bertil

    2014-01-01

    Glutaraldehyde (GA) reacts with amino groups in proteins, forming intermolecular cross-links that, at sufficiently high protein concentration, can transform a protein solution into a gel. Although GA has been used as a cross-linking reagent for decades, neither the cross-linking chemistry nor the microstructure of the resulting protein gel have been clearly established. Here we use small-angle X-ray scattering (SAXS) to characterise the microstructure and structural kinetics of gels formed by cross-linking of pancreatic trypsin inhibitor, myoglobin or intestinal fatty acid-binding protein. By comparing the scattering from gels and dilute solutions, we extract the structure factor and the pair correlation function of the gel. The protein gels are spatially heterogeneous, with dense clusters linked by sparse networks. Within the clusters, adjacent protein molecules are almost in contact, but the protein concentration in the cluster is much lower than in a crystal. At the $\\sim$ 1 nm SAXS resolution, the native ...

  6. Native American Geometry

    NSDL National Science Digital Library

    Hardaker, Chris.

    This Website, sprung from a gifted-and-talented program for K-12 students in Arizona, presents the interesting world of Native American geometry, a system based on the proportional relationship between the radius and circumference of a circle. The eye-pleasing site, divided into sections that include Foundations, Education, Designs, and Anthropology, would be appealing to curious Web surfers along with mathematics students. Geometric principles of proportions and angles are presented in the context of Native American designs, joining art and science and allowing students to learn in a creative, applied fashion. Some highlights of the site include illustrated examples of how corporate logos such as those of Mitsubishi or CBS Television are based on this geometry and a page on the architectural geometries of archaeologic sites such as Chaco Canyon, NM. A brief discussion of the history of circle-based ("string and two sticks") geometry throughout the world and a list of references for teachers are also important parts of this site.

  7. Perceiving non-native speech.

    PubMed

    Bürki-Cohen, J; Miller, J L; Eimas, P D

    2001-06-01

    In a series of experiments using monosyllabic words produced by a native and a non-native speaker of English, native English speakers monitored the word-initial consonants of the words to decide which of two consonants was present on each trial. In some of the experiments, a secondary task of a linguistic nature, deciding whether the target-bearing word was a noun or verb, was also required. When the words were presented in silence, the native and non-native stimuli were processed in a like manner. Specifically, when the secondary task was not required, phonemic decisions tended to be made on the basis of prelexical information, whereas when the secondary task was required, they tended to be made on the basis of postlexical information (see Eimas, Marcovitz Hornstein, & Payton, 1990). However, when the listening conditions were degraded by presenting the words at a lower level and in noise, the two types of stimuli yielded different patterns. Native speech was processed as before, whereas for non-native speech phonemic decisions now tended to be made on the basis of postlexical information both when a secondary task was required and when it was not. The contrasting results for native and non-native speech are discussed in terms of models of phoneme processing. PMID:11575902

  8. Native and Non-Native Teachers in the Classroom.

    ERIC Educational Resources Information Center

    Arva, V.; Medgyes, P.

    2000-01-01

    Revisits the issue of the native versus the nonnative speaker in the area of English language teaching. The main goal was to examine the teaching behavior of two groups of teachers, native and nonnative, who have exhibited differences not only in terms of their language backgrounds, but also in terms of their qualifications and relevant teaching…

  9. Hydrodynamics of active permeating gels

    NASA Astrophysics Data System (ADS)

    Callan-Jones, A. C.; Jülicher, F.

    2011-09-01

    We develop a hydrodynamic theory of active permeating gels with viscoelasticity in which a polymer network is embedded in a background fluid. This situation is motivated by active processes in the cell cytoskeleton in which motor molecules generate elastic stresses in the network, which can drive permeation flows of the cytosol. Our approach differs from earlier ones by considering the elastic strain in the polymer network as a slowly relaxing dynamical variable. We first present the general ideas for the case of a passive, isotropic gel and then extend this description to a polar, active gel. We discuss two specific cases to illustrate the role of permeation in active gels: self-propulsion of a thin slab of gel relative to a substrate driven by filament polymerization and depolymerization; and non-equilibrium deswelling of a gel driven by molecular motors.

  10. In-gel screening of phosphorus and copper, zinc and iron in proteins of yeast mitochondria by LA-ICP-MS and identification of phosphorylated protein structures by MALDI-FT-ICR-MS after separation with two-dimensional gel electrophoresis

    Microsoft Academic Search

    J. Sabine Becker; Miroslav Zoriy; Udo Krause-Buchholz; J. Susanne Becker; Carola Pickhardt; Michael Przybylski; Gerhard Rodelb

    2004-01-01

    A new screening technique using two-dimensional gels was developed in order to rapidly identify various elements in well-separated protein spots. Yeast mitochondrial proteins were separated using two-dimensional gel electrophoresis (blue native\\/SDS 2D-PAGE) and marked by silver staining. The 2D gels were systematically analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) using a double-focusing sector field instrument. From more

  11. Polyoxometalate-based Supramolecular Gel

    NASA Astrophysics Data System (ADS)

    He, Peilei; Xu, Biao; Liu, Huiling; He, Su; Saleem, Faisal; Wang, Xun

    2013-05-01

    Self-assemblyings of surfactant-encapsulated Wells-Dawson polyoxometalates (SEPs) nanobuilding blocks in butanone and esters yielded supramolecular gels showing thermo and photo responsive properties. The gels can be further polymerized if unsaturated esters were used and subsequently electrospinned into nanowires and non-woven mats. The as-prepared non-woven mats have a Young's modulus as high as 542.55 MPa. It is believed that this supramolecular gel is a good platform for polyoxometalates processing.

  12. Supramolecular gels: functions and uses.

    PubMed

    Sangeetha, Neralagatta M; Maitra, Uday

    2005-10-01

    In recent years there has been immense interest in studying gels derived from low molecular mass gelators (supramolecular, or simply molecular gels). The motivation for this is not only to understand the fundamental aggregate structures in the gels at different length scales, but also to explore their potential for futuristic technological applications. Gels have been made sensitive to external stimuli like light and chemical entities by incorporating a spectroscopically active or a receptor unit as part of the gelator molecule. This makes them suitable for applications such as sensing and actuating. The diversity of gel structural architectures has allowed them to be utilized as templates to prepare novel inorganic superstructures for possible applications in catalysis and separation. Gels derived from liquid crystals (anisotropy gels) that can act as dynamically functional materials have been prepared, for example, for (re-writable) information recording. Supramolecular gels can be important in controlled release applications, in oil recovery, for gelling cryogenic fuels etc. They can also serve as media for a range of applications. This tutorial review highlights some of the instructive work done by various groups to develop smart and functional gels, and covers a wide spectrum of scientific interest ranging from medicine to materials science. PMID:16172672

  13. Synthetic tracheal mucus with native rheological and surface tension properties.

    PubMed

    Hamed, R; Fiegel, J

    2014-06-01

    In this study, the development of a model tracheal mucus with chemical composition and physical properties (bulk viscoelasticity and surface tension) matched to that of native tracheal mucus is described. The mucus mimetics (MMs) were formulated using components that are abundant in tracheal mucus (glycoproteins, proteins, lipids, ions, and water) at concentrations similar to those found natively. Pure solutions were unable to achieve the gel behavior observed with native mucus. The addition of a bifunctional cross-linking agent enabled control over the viscoelastic properties of the MMs by tailoring the concentration of the cross-linking agent and the duration of cross-linking. Three MM formulations with different bulk viscoelastic properties, all within the normal range for nondiseased tracheal mucus, were chosen for investigation of surfactant spreading at the air-mimetic interface. Surfactant spread quickly and completely on the least viscoelastic mimetic surface, enabling the surface tension of the mimetic to be lowered to match native tracheal mucus. However, surfactant spreading on the more viscoelastic mimetics was hindered, suggesting that the bulk properties of the mimetics dictate the range of surface properties that can be achieved. PMID:23813841

  14. Genetic conservation of native trees

    E-print Network

    Genetic conservation of native trees Scott McG. Wilson1 and C. J. A. Samuel Over recent years, the genetic conservation of British native tree populations has become an increasingly important part policy-makers in the genetic basis of forest biodiversity conservation, both at the UK and, more

  15. Physical Activity and Native Americans

    Microsoft Academic Search

    James D. Coble; Ryan E. Rhodes

    2006-01-01

    The physical activity behaviors of Native-American populations in the United States and Canada have received little attention in the health literature. The purpose of this review was to unite the literature regarding the physical activity behaviors of Native Americans. A majority of the literature was obtained using online databases. Reference lists were also reviewed to gain further access to the

  16. Alcohol abuse among Native Americans

    Microsoft Academic Search

    Roland J. Lamarine

    1988-01-01

    Native Americans have experienced substantial problems with alcohol since its introduction to their culture by early European settlers. Epidemiological data indicate that elevated morbidity and mortality attributable to alcohol abuse among this population remain at epidemic levels. Adolescent drinking patterns and family and peer influences on alcohol use are examined. A multifactorial etiology is indicated in the origin of Native

  17. Native American Foods and Cookery.

    ERIC Educational Resources Information Center

    Taylor, Tom; Potter, Eloise F.

    Native Americans had a well-developed agriculture long before the arrival of the Europeans. Three staples--corn, beans, and squash--were supplemented with other gathered plants or cultivated crops such as white potatoes, sweet potatoes, pumpkins, and peanuts. Native Americans had no cows, pigs, or domesticated chickens; they depended almost…

  18. Effects of added polyacrylamide on changes in water states during the composting of kitchen waste.

    PubMed

    Yang, Yu-Qiang; Chen, Zhuo-Xian; Zhang, Xue-Qing; Hu, Li-Fang; Shen, Dong-Sheng; Long, Yu-Yang

    2015-02-01

    The effects of adding polyacrylamide (PAM), to attempt to delay the loss of capillary water and achieve a better level of organic matter humification, in the composting of kitchen waste were evaluated. Four treatments, with initial moisture content of 60 % were used: 0.1 % PAM added before the start of composting (R1), 0.1 % PAM added when the thermophilic phase of composting became stable (at >50 °C) (R2), 0.1 % PAM added when the moisture content significantly decreased (R3), and no PAM added (R4). The introduction of PAM in R1 and R2 significantly increased the capillary force and delayed the loss of moisture content and capillary water. The introduction of PAM in R2 and R3 improved the composting process, in terms of the degradation of biochemical fractions and the humification degree. These results show that the optimal time for adding PAM was the initial stage of the thermophilic phase. PMID:25182430

  19. Mercapto functionalized silica entrapped polyacrylamide hydrogel: Arsenic adsorption behaviour from aqueous solution.

    PubMed

    Kumar, Rajesh; Jain, S K; Verma, S; Malodia, P

    2015-10-15

    In this article, 3-mercaptopropyl functionalized silica entrapped polyacrylamide hydrogel (MPFS-PAA) was prepared and characterized by FT-IR, scanning electron microscopy (SEM) and energy dispersion X-ray spectroscopy (EDS). Synthesized hydrogel was evaluated for removal of arsenic(III) from aqueous solution. Adsorption studies were carried out by batch method as function of contact time, initial concentration of arsenic and pH. As(III) adsorption data fitted well with Langmuir and Freundlich isotherm models. Adsorption capacity of arsenic 92.5?g/g was obtained at initial concentration of 100?g/L by Langmuir isotherm. Adsorption kinetics was tested for pseudo-second order reaction at different contact time. The rate constants of pseudo second order reaction were calculated and good correlation coefficient R(2) 99.67 obtained. The results indicates that MPFS-PAA is an effective adsorbent for removal of As(III) from aqueous solution. PMID:26151463

  20. A pH effect in the HPSEC separation of polyacrylamide-based copolymers

    SciTech Connect

    Papazian, L.A. (American Cyanamid Co., Chemical Research Div., Stamford, CT (US))

    1990-01-01

    This paper reports on four polyacrylamide-based samples, having the same nominal molecular weight and molecular weight distribution, characterized by HPSEC using two column sets and a mobile phase of phosphate buffer. Depending upon the pH, the separations demonstrate that the systematic differences between samples are influenced by the level of anionic sites along the polymer chain. It is found that the HPSEC elution profiles of these samples are reversed when the pH is changed from 2.2 to 7.0. The anionicity of the samples ranges from less than 0.5 mole % carboxyl content (the homopolymer of acrylamide) to 33.0 mole %. Capillary viscometry data support these findings in the two solvent media, indicating that no adsorption effects prevail in the chromatography. Static and on-line low angle laser light scattering (LALLS) data on the homopolymer of acrylamide also suggest that no adsorption or degradation is occurring in the chromatographic process.

  1. The concentration dependence of the solution viscosity and the relaxation time of the partially hydrolyzed polyacrylamides

    SciTech Connect

    Kanatharana, J.; Sukpisan, J.; Wang, S.Q. [Chulaongkorn Univ., Bangkok (Thailand)] [and others

    1995-12-01

    The dependences on the polyion concentration through the scaling relations in {eta} {alpha} c{sup {alpha}} and {Tau}{sub q} {alpha} c{sup {beta}}, where {eta} and {Tau}{sub q} are the solution viscosity and the relaxation time obtained from the dynamic light scattering respectively, are investigated for the partially hydrolyzed polyacrylamides at different degrees of hydrolysis. The scaling exponents a and {beta}, as determined in the semidilute regime, depend critically on the amount of salt added or the ionic strength. Both exponents, however, are independent of the amount of glycerol added which suggests that the excluded volume effect is relatively small in comparison with the effect of electrostatic repulsion. The salt-concentration dependence of the solution is also investigated: the corresponding scaling exponents for the 70% HPAM are insensitive to the solvent quality. The present experiment results are compared with recent scaling theories.

  2. The electro-responsive drug delivery from salicylic acid -loaded polyacrylamide hydrogels

    NASA Astrophysics Data System (ADS)

    Niamlang, Sumonman; Sirivat, Anuvat

    2007-03-01

    The release mechanisms and the diffusion coefficients of salicylic acid -loaded polyacrylamide hydrogels were investigated experimentally by using a modified Franz-Diffusion cell at the temperature of 37 ^0C to determine the effects of crosslinking ratio and electric field strength. The fabricated hydrogels retain their physical shapes and sizes during the experiments along with data reproducibility. A significant amount of salicylic is released within 48 hours from the hydrogels of various crosslinking ratios with and without electric field; the release profile follows the Q vs. t^1/2 relationship. Diffusion coefficients, as determined from the Higuchi equation, increase with electric field strength and reach maximum values at electric field strength of 0.1 V due to the electrophoresis of salicylic drug and become saturated at electric field strengths between 0.5 -- 10 V.

  3. Polyvinylpyrollidone and Polyacrylamide as Corrosion Inhibitors for Mild Steel in Acidic Medium

    NASA Astrophysics Data System (ADS)

    Umoren, S. A.; Obot, I. B.

    The corrosion inhibition of mild steel in 1 M H2SO4 in the presence of polyvinylpyrollidone (PVP) and polyacrylamide (PA) as inhibitors at 30-60°C was studied using gravimetric and gasometric techniques. The inhibition efficiency (1%) increased with increase in concentration of the inhibitors. Increase in temperature increased the corrosion rate in the absence and presence of inhibitors but decreased the inhibition efficiency. Both PVP and PA were found to obey Temkin adsorption isotherm and Kinetic-Thermodynamic Model of El-Awady at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameters obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. PVP was found to be a better inhibitor than PA.

  4. Effect of Electric Field Strength on Diffusion of Ionic Drugs from Polyacrylamide Hydrogels

    NASA Astrophysics Data System (ADS)

    Sirivat, Anuvat; Niamlang, Sumonman

    2010-03-01

    The apparent diffusion coefficients, Dapp, and the release mechanisms of ionic-drugs from drug-loaded polyacrylamide hydrogels, drug-loaded PAAM, were investigated for the effects of various drug sizes (Lactic acid, 3.11 å; Sulfanilamide,3.47 å; Ampicillin, 5.14 å), matrix pore sizes, and electric filed strengths. The Dapp of the drugs from the drug-loaded PAAM increases with decreasing drug size, increasing matrix pore size or applied electric field strength. The increase in Dapp can be attributed to the combination of the iontophoresis and the electroporation of the matrix pore. The Dapp of drug from the drug-loaded PAAM apparently obey the scaling behavior: Dapp/Do=(drug size/pore size)m with the scaling exponent m equal to 0.73 and 0.50 at the electric fields of 0 and 0.1 V, respectively.

  5. Gel Permeation Chromatography: Gel Preparation and Packing Technique

    Microsoft Academic Search

    F. W. Peaker; C. R. Tweedale

    1967-01-01

    SINCE the original publication by Moore1, gel permeation chromatography has been widely recognized as a rapid means of assessing the molecular weight distributions of polymeric materials soluble in organic solvents. While the use of this technique, principally based on the reliable commercial instrument2, is well established, reference in published work to the preparation of the cross-linked polystyrene gel, and its

  6. Rheology and structure of milk protein gels

    Microsoft Academic Search

    Ton van Vliet; Catriona M. M. Lakemond; Ronald W. Visschers

    2004-01-01

    Recent studies on gel formation and rheology of milk gels are reviewed. A distinction is made between gels formed by aggregated casein, gels of ‘pure’ whey proteins and gels in which both casein and whey proteins contribute to their properties. For casein–whey protein mixtures, it has been shown that both the fraction whey protein aggregated with the casein particles and

  7. Homogeneity of gels and gel-derived glasses

    NASA Technical Reports Server (NTRS)

    Mukherjee, S. P.

    1984-01-01

    The significance and implications of gel preparation procedures in controlling the homogeneity of multicomponent oxide gels are discussed. The role of physicochemical factors such as the structure and chemical reactivities of alkoxides, the formation of double-metal alkoxides, and the nature of solvent(s) are critically analyzed in the context of homogeneity of gels during gelation. Three procedures for preparing gels in the SiO2-B2O3-Na2O system are examined in the context of cation distribution. Light scattering results for glasses in the SiO2-B2O3-Na2O system prepared by both the gel technique and the conventional technique are examined.

  8. Long-Term Polyacrylamide Formulation Effects on Soil Erosion, Water Infiltration, and Yields of Furrow-Irrigated Crops

    Microsoft Academic Search

    Rodrick D. Lentz; Robert E. Sojka

    2009-01-01

    Two formulations of water-soluble anionic polyacrylamide (WSPAM) are used in agriculture to reduce erosion and manage infi ltration in furrow irrigations, although few if any reports have compared their eff ectiveness. A control and two WSPAMs, a granular form and the inverse emulsion, or oil-based liquid form, were applied to irrigation water supplied to furrows formed in a silt loam

  9. Crystallization of steroids in gels

    NASA Astrophysics Data System (ADS)

    Kalkura, S. Narayana; Devanarayanan, S.

    1991-03-01

    The crystal growth and characterization of certain steriods, viz., cholesterol, cholesteryl acetate, ?-sitosterol, progesterone and testosterone, in a silica gel medium is discussed. The present study shows that the single test tube diffusion method can be used to grow crystals of steroids in a silica gel medium by the reduction of steroid solubility.

  10. Foam and gel decontamination techniques

    Microsoft Academic Search

    J. F. McGlynn; W. N. Rankin

    1989-01-01

    The Savannah River Site is investigating decontamination technology to improve current decontamination techniques, and thereby reduce radiation exposure to plant personnel, reduce uptake of radioactive material, and improve safety during decontamination and decommissioning activities. When decontamination chemicals are applied as foam and gels, the contact time and cleaning ability of the chemical increases. Foam and gel applicators apply foam or

  11. Living bacteria in silica gels

    NASA Astrophysics Data System (ADS)

    Nassif, Nadine; Bouvet, Odile; Noelle Rager, Marie; Roux, Cécile; Coradin, Thibaud; Livage, Jacques

    2002-09-01

    The encapsulation of enzymes within silica gels has been extensively studied during the past decade for the design of biosensors and bioreactors. Yeast spores and bacteria have also been recently immobilized within silica gels where they retain their enzymatic activity, but the problem of the long-term viability of whole cells in an inorganic matrix has never been fully addressed. It is a real challenge for the development of sol-gel processes. Generic tests have been performed to check the viability of Escherichia coli bacteria in silica gels. Surprisingly, more bacteria remain culturable in the gel than in an aqueous suspension. The metabolic activity of the bacteria towards glycolysis decreases slowly, but half of the bacteria are still viable after one month. When confined within a mineral environment, bacteria do not form colonies. The exchange of chemical signals between isolated bacteria rather than aggregates can then be studied, a point that could be very important for 'quorum sensing'.

  12. Methylthymol blue in Fricke gels

    NASA Astrophysics Data System (ADS)

    Penev, K. I.; Mequanint, K.

    2015-01-01

    The initial trial of methylthymol blue (MTB) as a chelator for ferric iron in Fricke gel dosimeters, used for three-dimensional (3D) dosimetry in cancer radiotherapy, is reported. MTB is a structural analogue of the conventionally used xylenol orange (XO); however, the absorbance spectrum of the ferric-MTB complex is shifted to higher wavelengths, which should allow for lower amount of light scattering during gel scanning. In this study, two gelatin substrates, two sources of XO and one source of MTB have been compared. The MTB- containing gels exhibited similar dose response and diffusion coefficient to the XO-containing gels at their wavelengths of maximum absorption (620 and 585 nm, respectively). In addition, the MTB gels gave an excellent dose response at 633 nm, which is an important wavelength that is already used with other 3D dosimeters.

  13. A new injectable biphasic hydrogel based on partially hydrolyzed polyacrylamide and nano hydroxyapatite, crosslinked with chromium acetate, as scaffold for cartilage regeneration

    NASA Astrophysics Data System (ADS)

    Koushki, N.; Tavassoli, H.; Katbab, A. A.; Katbab, P.; Bonakdar, S.

    2015-05-01

    Polymer scaffolds are applied in the field of tissue engineering as three dimensional structures to organize cells and present stimuli to direct generation of a desired damaged tissue. In situ gelling scaffolds have attracted great attentions, as they are structurally similar to the extra cellular matrix (ECM). In the present work, attempts have been made to design and fabricate a new injectable and crosslinkable biphasic hydrogel based on partially hydrolyzed polyacrylamide (HPAM), chromium acetate as crosslink agent and nanocrystalline hydroxyapatite (nHAp) as reinforcing and bioactive agent for repair and regeneration of damaged cartilage. The distinct characteristic of HPAM is the presence of carboxylate anion groups on its backbone which allows to engineer the structure of the hydrogel for the desired bioactivity with appropriate cells differentiation towards both soft and hard (bone) tissues. The synthesized hydrogel exhibited bifunctional behavior which was derived by its biphasic structure in which one phase was loaded with nano hydroxyapatite to provide integration capability by subchondral bones and fix the hydrogel at cartilage defect without a need for suturing. The other phase differentiates the rabbit adipogenic mesenchymal stem cells (MSCs) towards soft tissue. Rheomechanical spectrometry (RMS) was employed to study the kinetic of the gelation including induction time and rate, as well as to measure the ultimate elastic modulus of the optimum crosslinked hydrogel. Surface tension measurement was also performed to tailor the surface characteristics of the gels. In vitro culturing of the cells inside the crosslinked hydrogel revealed high viability and high differentiation of the encapsulated rabbit stem cells, providing that the chromium acetate level was kept below 0.2 wt%. Based on the obtained results, the designed and fabricated biphasic hydrogel exhibited high potential as carrier for the stem cells for cartilage tissue engineering application with excellent injectability.

  14. Partitioning of humic acids between aqueous solution and hydrogel. 3. Microelectrodic dynamic speciation analysis of free and bound humic metal complexes in the gel phase.

    PubMed

    Yasadi, Kamuran; Pinheiro, Jose Paulo; Zieli?ska, Katarzyna; Town, Raewyn M; van Leeuwen, Herman P

    2015-02-10

    The hydrogel/water partitioning of the various species in the cadmium(II)/soil humic acid (HA) system is studied for two types of gel, using in situ microelectrodic voltammetry. Under the conditions of this work, with HA particles of ca. 25 and 125 nm radius, the CdHA complex is shown to be close to nonlabile toward a 12.5 ?m radius microelectrode. This implies that its kinetic contribution to Cd(2+) reduction at the medium/microelectrode interface is practically negligible. The polyacrylamide (PAAm) gels equilibrate with the aqueous medium under significant sorption of HA at the gel backbone/gel medium interface, which in turn leads to induced sorption of Cd(II) in the form of immobilized gel-bound CdHA. The rather high total Cd content of the PAAm gel suggests that the binding of Cd(2+) by the hydrophobically gel-bound HA is stronger than that for dispersed HA particles. Still, the intraparticulate speciation of Cd(II) over Cd(2+) and CdHA corresponds to an intrinsic stability constant similar to that for simple monocarboxylate ligands such as acetate. Alginate gels are negatively charged, and their free [Cd(aq)(2+)] is higher than that in the medium by the corresponding Donnan coefficient. On top of that, Cd(2+) is specifically sorbed by the gel backbone/gel medium interface to reach accumulation factors as high as a few tens. HA and CdHA accumulate in the outer 20 ?m film of gel at the gel/water interface of both gels, but they do not penetrate into the bulk of the alginate gel. Overall, the gel/water interface dictates drastic changes in the speciation of Cd/HA as compared to the aqueous medium, with distinct features for each individual type of gel. The results have broad significance, for example, for predictions of reactivity and bioavailability of metal species which inherently involve partitioning and diffusion into diverse gel layers such as biointerfacial cell walls, biofilm matrices, and mucous membranes. PMID:25580682

  15. Polyethylene glycol derivatives of base and sequence specific DNA ligands: DNA interaction and application for base specific separation of DNA fragments by gel electrophoresis.

    PubMed Central

    Müller, W; Hattesohl, I; Schuetz, H J; Meyer, G

    1981-01-01

    Various base pair specific DNA ligands comprising a phenyl phenazinium dye, a triphenylmethan dye and Hoechst 33258 were covalently bound to polyethylene glycol (PEG) via ester or ether bonds. The DNA interactions of the PEG derivatives formed were shown to exhibit the same base pair specificity as the parent compounds. Since the PEG chains thus bound to the DNA could be expected to increase drastically the frictional coefficient of the DNA, the PEG derivatives were used for base specific DNA separations in agarose and polyacrylamide gel electrophoresis. The procedures, which do not require any special techniques, are described in detail. The resolution observed in agarose gels allows one to separate equally sized DNA fragments differing as little as 1% in base composition at mean travel distances of about 10 cm. Examples of gels showing the base compositional heterogeneity of restriction fragments obtained from lambda DNA, E. coli DNA and calf thymus DNA are given. Images PMID:6259622

  16. Alaska Native Teens Help Researchers

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2009-01-13

    In this video adapted from KUAC-TV and the Geophysical Institute at the University of Alaska, Fairbanks, Alaska Native students contribute to research on how their environment is changing as a result of global warming.

  17. for Non-Native Teachers

    ERIC Educational Resources Information Center

    Williams, Sharon Vegh

    2013-01-01

    work for, are often disconnected from the language, culture, and approaches to learning that facilitate Native students' achievement in school (Deyhle & Swisher, 1997; Klug & Hall, 2002; Lomawaima, 2001; Pewewardy, 2002; Reyhner & Jacobs, 2002; Tharp,…

  18. Learning from Native Adult Education.

    ERIC Educational Resources Information Center

    Orr, Jeffrey A.

    2000-01-01

    Describes the Native American concept of the Medicine Wheel, which symbolizes the unity of mental, spiritual, physical, and emotional dimensions. Includes strategies for using it to cultivate a spiritual way of being in adult education. (SK)

  19. Lignin Gels: SOL-GEL NANOPOROUS CARBONS & COMPOSITES

    E-print Network

    Cao, Guozhong

    synthesis of phenolic resins (a renewable source) followed by freeze drying and subsequent pyrolysis matter) + amine catalyst in an organic Processing: · gel + aging time: 7days at 80ºC · Freeze drying

  20. Hydrodynamics of Active Permeating Gels

    NASA Astrophysics Data System (ADS)

    Callan-Jones, Andrew; Jülicher, Frank

    2012-02-01

    We present a hydrodynamic theory of active viscoelastic gels in which a polymer network is embedded in a background fluid. This work is motivated by active processes in the cell cytoskeleton in which motor molecules generate elastic stresses in the network which can drive permeation flows of the cytosol. Our approach differs from earlier ones by considering the elastic strain in the polymer network as a slowly relaxing dynamical variable. We discuss a specific case that illustrates the role of permeation in active gels: the self-propulsion of a thin slab of gel relative to a substrate driven by filament polymerization and depolymerization.

  1. Adhesive, elastomeric gel impregnating composition

    DOEpatents

    Shaw, David Glenn (Tucson, AZ); Pollard, John Randolph (Tucson, AZ); Brooks, Robert Aubrey (Tijeras, NM)

    2002-01-01

    An improved capacitor roll with alternating film and foil layers is impregnated with an adhesive, elastomeric gel composition. The gel composition is a blend of a plasticizer, a polyol, a maleic anhydride that reacts with the polyol to form a polyester, and a catalyst for the reaction. The impregnant composition is introduced to the film and foil layers while still in a liquid form and then pressure is applied to aid with impregnation. The impregnant composition is cured to form the adhesive, elastomeric gel. Pressure is maintained during curing.

  2. Native Hawaiian views on biobanking.

    PubMed

    Tauali i, Maile; Davis, Elise Leimomi; Braun, Kathryn L; Tsark, JoAnn Umilani; Brown, Ngiare; Hudson, Maui; Burke, Wylie

    2014-09-01

    Genomic science represents a new frontier for health research and will provide important tools for personalizing health care. Biospecimen-based research is an important mechanism for expanding the genomic research capacity, and indigenous peoples are a target of biospecimen-based research due to their relative isolation and the potential to discover rare or unique genotypes. This study explored Native Hawaiian perceptions of and expectations for biobanking. Ten discussion groups were conducted with Native Hawaiians (N?=?92), who first heard a presentation on biobanking. Six themes emerged: (1) biobank governance by the Native Hawaiian community, (2) research transparency, (3) priority of Native Hawaiian health concerns, (4) leadership by Native Hawaiian scientists accountable to community, (5) re-consenting each time specimen is used, and (6) education of Native Hawaiian communities. Considered together, these findings suggest that biobanking should be guided by six principles that comprise "G.R.E.A.T. Research" (Governance, Re-consent, Education, Accountability, Transparency, Research priorities). These recommendations are being shared with biobanking facilities in Hawai'i as they develop protocols for biobanking participation, governance, and education. These findings also inform researchers and indigenous peoples throughout the world who are working on biobanking and genomic research initiatives in their nations. PMID:24683042

  3. Neighboring nucleotide interactions during DNA sequencing gel electrophoresis.

    PubMed Central

    Bowling, J M; Bruner, K L; Cmarik, J L; Tibbetts, C

    1991-01-01

    Electrophoretic separation of oligonucleotides in denaturing polyacrylamide gels is primarily a function of length-dependent mobility. The 3' terminal nucleotide sequence of the oligonucleotide is a significant, secondary determinant of mobility and separation. Oligomers with 3'-ddT migrate more slowly than expected on the basis of length alone, and thus are better separated from the preceding, shorter oligomers in the sequencing ladder. Oligomers with 3'-ddC are relatively faster than expected, and are therefore less separated. At the 3' penultimate position, -dC- increases and -dT- reduces separation. Purines at the 3' terminal or penultimate positions of oligonucleotides affect separation less than the pyrimidines. These results suggest specific interactions among neighboring nucleotides with important effects on the conformation of oligonucleotides during electrophoresis. These interactions are compared to compression artifacts, which represent more extreme anomalies of length-dependent separation of oligonucleotides. Knowledge of base-specific effects on electrophoretic behavior of DNA oligomers supplements the usual information available for determination of sequences; additionally it provides an avenue to thermodynamic and hydrodynamic investigations of DNA structure. PMID:2057365

  4. Native American Healing Practices and Counseling

    ERIC Educational Resources Information Center

    Rybak, Christopher J.; Eastin, Carol Lakota; Robbins, Irma

    2004-01-01

    An experiential Native American healing practices course, co-taught by a Native American pastoral counselor and a counselor educator, was offered to graduate counseling students to help them better understand Native American worldviews. A student participant's reflections are included. Students attended Native American ceremonies and learned…

  5. Native-American elders. Health care status.

    PubMed

    Rousseau, P

    1995-02-01

    This article reviews current data relevant to the health care status of elderly Native Americans, a population cohort encompassing American Indians and Alaskan Natives/Aleutians. Several topics are addressed, including the history of Native American health policy, heart disease, diabetes mellitus, cancer, oral health, nutrition, long-term care, and the circumstances of urban Native American elders. PMID:7720023

  6. Native Plants and PollinatorsNative Plants and PollinatorsNative Plants and PollinatorsNative Plants and Pollinators of Loney Meadowof Loney Meadowof Loney Meadowof Loney Meadow

    E-print Network

    Ferrara, Katherine W.

    Native Plants and PollinatorsNative Plants and PollinatorsNative Plants and PollinatorsNative Plants and Pollinators of Loney Meadowof Loney Meadowof Loney Meadowof Loney Meadow A walk with Dr, water, insect repellent, sunscreen and wear suitableBring: lunch, water, insect repellent, sunscreen

  7. Polyacrylamide application versus forest residue mulching for reducing post-fire runoff and soil erosion.

    PubMed

    Prats, Sergio Alegre; Martins, Martinho António Dos Santos; Malvar, Maruxa Cortizo; Ben-Hur, Meni; Keizer, Jan Jacob

    2014-01-15

    For several years now, forest fires have been known to increase overland flow and soil erosion. However, mitigation of these effects has been little studied, especially outside the USA. This study aimed to quantify the effectiveness of two so-called emergency treatments to reduce post-fire runoff and soil losses at the microplot scale in a eucalyptus plantation in north-central Portugal. The treatments involved the application of chopped eucalyptus bark mulch at a rate of 10-12 Mg ha(-1), and surface application of a dry, granular, anionic polyacrylamide (PAM) at a rate of 50 kg ha(-1). During the first year after a wildfire in 2010, 1419 mm of rainfall produced, on average, 785 mm of overland flow in the untreated plots and 8.4 Mg ha(-1) of soil losses. Mulching reduced these two figures significantly, by an average 52 and 93%, respectively. In contrast, the PAM-treated plots did not differ from the control plots, despite slightly lower runoff but higher soil erosion figures. When compared to the control plots, mean key factors for runoff and soil erosion were different in the case of the mulched but not the PAM plots. Notably, the plots on the lower half of the slope registered bigger runoff and erosion figures than those on the upper half of the slope. This could be explained by differences in fire intensity and, ultimately, in pre-fire standing biomass. PMID:24055663

  8. Polyacrylamide-hydroxyapatite composite: Preparation, characterization and adsorptive features for uranium and thorium

    NASA Astrophysics Data System (ADS)

    Bayba?, Demet; Ulusoy, Ulvi

    2012-10-01

    The composite of synthetically produced hydroxyapatite (HAP) and polyacrylamide was prepared (PAAm-HAP) and characterized by BET, FT-IR, TGA, XRD, SEM and PZC analysis. The adsorptive features of HAP and PAAm-HAP were compared for UO22+ and Th4+. The entrapment of HAP into PAAm-HAP did not change the structure of HAP. Both structures had high affinity to the studied ions. The adsorption capacity of PAAm-HAP was than that of HAP. The adsorption dependence on pH and ionic intensity provided supportive evidences for the effect of complex formation on adsorption process. The adsorption kinetics was well compatible to pseudo second order model. The values of enthalpy and entropy changes were positive. Th4+ adsorption from the leachate obtained from a regional fluorite rock confirmed the selectivity of PAAm-HAP for this ion. In consequence, PAAm-HAP should be considered amongst favorite adsorbents for especially deposition of nuclear waste containing U and Th, and radionuclide at secular equilibrium with these elements.

  9. Arsenic remediation from drinking water by synthesized nano-alumina dispersed in chitosan-grafted polyacrylamide.

    PubMed

    Saha, Suparna; Sarkar, Priyabrata

    2012-08-15

    An arsenic adsorbent comprising alumina nanoparticles dispersed in polymer matrix was developed and its removal potential studied. Alumina nanoparticles were prepared by reverse microemulsion technique and these were immobilized on chitosan grafted polyacrylamide matrix by in situ dispersion. The loading capacity of this new synthesized adsorbent was found to be high (6.56 mg/g). Batch adsorption studies were performed as a function of contact time, initial arsenic concentration, pH and presence of competing anions. The removal was found to be pH dependent, and maximum removal was obtained at pH 7.2 while the equilibrium time was 6h. The equilibrium adsorption data fitted very well with Freundlich isotherm. However, the D-R isotherm studies indicated that chemisorptions might play an important role. This was also confirmed by the FTIR study of the arsenic loaded adsorbent. A mechanism of arsenic sorption by the new polymeric adsorbent has been proposed. The regeneration study of the adsorbent resulted in retention of 94% capacity in the fifth cycle. An optimum pH of 7.2, operation at normal temperature, high adsorption capacity and good recycle potential of this new adsorbent would make it an ideal material for removal of arsenic from drinking water. PMID:22647233

  10. Self-healable, tough, and ultrastretchable nanocomposite hydrogels based on reversible polyacrylamide/montmorillonite adsorption.

    PubMed

    Gao, Guorong; Du, Gaolai; Sun, Yuanna; Fu, Jun

    2015-03-01

    Nanocomposite hydrogels with unprecedented stretchability, toughness, and self-healing have been developed by in situ polymerization of acrylamide with the presence of exfoliated montmorillonite (MMT) layers as noncovalent cross-linkers. The exfoliated MMT clay nanoplatelets with high aspect ratios, as confirmed by transmission electron microscopy (TEM) and X-ray diffraction (XRD) results, are well dispersed in the polyacrylamide matrix. Strong polymer/MMT interaction was confirmed by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The effective cross-link densities of these hydrogels are estimated in the range of 2.2-5.7 mol m(-3). Uniaxial tensile tests showed a very high fracture elongation up to 11?800% and a fracture toughness up to 10.1 MJ m(-3). Cyclic loading-unloading tests showed remarkable hysteresis, which indicates energy dissipation upon deformation. Residual strain after cyclic loadings could be recovered under mild conditions, with the recovery extent depending on clay content. A mechanism based on reversible desorption/adsorption of polymer chains on clay platelets surface is discussed. Finally, these nanocomposite hydrogels are demonstrated to fully heal by dry-reswell treatments. PMID:25668063

  11. Polyacrylamide-clinoptilolite/Y-zeolite composites: characterization and adsorptive features for terbium.

    PubMed

    Bayba?, Demet; Ulusoy, Ulvi

    2011-03-15

    The composites of natural (clinoptilolite) and synthetic zeolite (Z and YZ) with polyacrylamide (PAAm) were synthesized and characterized by FT-IR, TGA, XRD, SEM and PZC analysis. The adsorptive features of the minerals and its composites were investigated for Tb analogues to the rare earth elements (REs) by isotopic tracer method, (160)Tb was the radiotracer. The composites were the hybrid formations of PAAm and Z or YZ. Tb adsorption capacities of the composites were higher than those of bare Z and YZ. The compatibility of Tb adsorption kinetics to the second order and Weber-Morris models implied that the sorption process was chemical via ion exchange. The values of enthalpy and entropy changes were positive and the negative free enthalpy change was evidence for the spontaneity of adsorption. The reusability tests for the composites for five uses demonstrated that the adsorbents could be reused after complete recovery of the loaded ion. Unlike PAAm-YZ, PAAm-Z was resistant to acidic environment. The overall results eventually suggested that the composite of Z and PAAm was a potential cost effective adsorbent for Tb(3+) and REs. PMID:21256673

  12. Cationic polyacrylamide as coagulant aid with titanium tetrachloride for low molecule organic matter removal.

    PubMed

    Zhao, Y X; Gao, B Y; Qi, Q B; Wang, Y; Phuntsho, S; Kim, J-H; Yue, Q Y; Li, Q; Shon, H K

    2013-08-15

    This is the first attempt to use cationic polyacrylamide (PAM) as coagulant aid with titanium tetrachloride (TiCl4) to improve the coagulation performance and floc properties. Coagulation-flocculation treatment was applied to simulated water (with fulvic acid (FA) as model organic matter) for both coagulation behavior investigation and floc characterization. The effect of PAM on floc reformation properties after cyclic breakage/regrowth was also investigated. Ultrafiltration experiments were performed to investigate the influence of PAM aided TiCl4 coagulation on the membrane fouling. The results showed that organic removal was enhanced by PAM addition at low TiCl4 doses. Floc growth rate and floc size were significantly affected by dosing sequence. TiCl4-PAM significantly improved the floc strength factors (Sf) and recovery factors (Rf). The dosing sequence of TiCl4 and PAM significantly influenced the floc structure. Characterization of the flocculated sludge indicated that TiO2 with anatase structure and high photocatalytic activity could be obtained from the TiCl4-PAM flocculated sludge. PMID:23708450

  13. Effectiveness of Polyacrylamide (PAM) in Improving Runoff Water Quality From Construction Sites

    NASA Astrophysics Data System (ADS)

    Soupir, Michelle L.; Mostaghimi, Saied; Masters, Amanda; Flahive, Katherine A.; Vaughan, David H.; Mendez, Aida; McClellan, Phillip W.

    2004-02-01

    Erosion from construction sites significantly affects water quality in receiving streams. A rainfall simulator was used to evaluate the effectiveness of different methods for controlling erosion from construction sites. Erosion control methods investigated included dry and liquid applications of polyacrylamide (PAM), hydroseed, and straw mulch. Fertilizer was also applied to each plot to examine the effectiveness of the methods in reducing nutrient losses in runoff. Runoff samples were analyzed for total suspended solids (TSS), nitrate, total Kjeldahl nitrogen (TKN), ammonium, total phosphorus (TP), and orthophosphate. Among all treatments investigated, straw mulch was the most effective treatment for controlling TSS and nutrient losses during short term and long term simulations. The low liquid PAM (half the recommended PAM) treatment resulted in the highest reduction in runoff, TSS bound nitrogen, and total nitrogen (TN) concentrations and loadings. The study results indicate that a high application rate (twice the recommended rate) of PAM could actually increase runoff and TSS losses. At a low application rate, both liquid and dry PAM were effective in reducing TSS and nutrient losses in runoff. However, application of the liquid form of PAM to construction sites is more practical and perhaps more economical than applying the PAM in the dry form.

  14. Enhanced dewaterability of waste-activated sludge by combined cationic polyacrylamide and magnetic field pretreatment.

    PubMed

    Bi, Dongsu; Guo, Xiaopin; Cai, Zhihong; Yu, Zhen; Wang, Dingmei; Wang, Yueqiang

    2015-02-01

    The potential function of combining magnetic field (MF) pretreatment with cationic polyacrylamide (CPAM) additive on enhancing the dewaterability of waste-activated sludge was investigated in the present work. Two reactors were involved in a specially designed experimental apparatus, one of which was built with MF accessories. Several parameters were conducted, including CPAM dosages, MF strengths and processing times, respectively. Capillary suction time (CST) and specific resistance to filtration (SRF) were used to evaluate sludge dewaterability. Extracellular polymeric substances (EPS) concentration was also determined in an attempt to identify the observed changes in dewaterability. It was indicated by the results that both CPAM conditioning and MF pretreatment on sludge can lower CST and SRF values. However, subjecting to a combination of MF pretreatment and CPAM conditioning, sludge dewaterability was significantly enhanced beyond the level observed of CPAM addition alone. The lowest CST and SRF values of 36.5?s and 0.75?×?10(12)?m?kg(-1), respectively, were obtained when sludge was co-conditioned by CPAM (at a dosage of 40?mg?L(-1)) and MF (at an induction of 40?mT) for 30?min, suggesting the optimal condition for enhancing sludge dewaterability. It is also shown from the significant correlations between EPS, protein, polysaccharide and CST/SRF that the increment of EPS concentration in sludge supernatant may be the major reason for the enhancement of dewaterability. PMID:25518985

  15. Bioelectricity-assisted partial degradation of linear polyacrylamide in a bioelectrochemical system.

    PubMed

    Cui, Yu-Zhi; Zhang, Jian; Sun, Min; Zhai, Lin-Feng

    2015-01-01

    The wide application of water-soluble linear polyacrylamides (PAMs) can cause serious environmental pollution. Biological treatment of PAMs receives very limited efficiency due to their recalcitrance to the microbial degradation. Here, we show the bioelectrochemical system (BES) can be used as an effective strategy to improve the biodegradation efficiency of PAMs. A linear PAM with viscosity-average molecular weight of 5?×?10(6) was treated in the anodic chamber of BES reactor, and the change of PAM structure during the degradation process was investigated. The anodic bacteria in the BES demonstrated abilities to utilize the PAM as the sole carbon and nitrogen source to generate electricity. Both the anode-attached and planktonic bacteria contributed to the electricity generation, while the anode-attached community exhibited stronger electron transfer ability than the planktonic one. The closed-circuit and open-circuit operations of the BES reactor obtained chemical oxygen demand (COD) removal efficiencies of 32.5 and 7.4 %, respectively, implying the generation of bioelectricity could enhance the biodegradation of PAM. Structure analysis suggested the carbon chain of PAM was partially degraded in the BES, producing polymeric products with lower molecular weight. The microbial cleavage of the carbon chain was proposed to start from the "head-to-head" linkages and end with the formation of ether bonds. PMID:25193420

  16. Acetylcholinesterase immobilization on polyacrylamide/functionalized multi-walled carbon nanotube nanocomposite nanofibrous membrane.

    PubMed

    Amini, Navid; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Kalaee, Mohammad Reza; Hormozi, Saeed; Niknam, Kaveh; Firouzian, Nasrin

    2013-05-01

    In this work, polyacrylamide/multi-walled carbon nanotubes (MWCNT) solution is electrospun to nanocomposite nanofibrous membranes for acetylcholinesterase enzyme immobilization. A new method for enzyme immobilization is proposed, and the results of analysis show successful covalent bonding of enzymes on electrospun membrane surface besides their non-covalent entrapment. Fourier transform infrared spectroscopy, mechanical and thermal investigations of nanofibrous membrane approve successful cross-linking and enzyme immobilization. The enzyme relative activity and kinetic on both pure and nanocomposite membranes is investigated, and the results show proper performance of designed membrane to even improve the enzyme activity followed by immobilization compared to free enzyme. Scanning electron microscopy images show nanofibrous web of 3D structure with a low shrinkage and hydrogel structure followed by enzyme immobilization and cross-linking. Moreover, the important role of functionalized carbon nanotubes on final nanofibrous membrane functionality as a media for enzyme immobilization is investigated. The results show that MWCNT could act effectively for enzyme immobilization improvement via both physical (enhanced fibers' morphology and conductivity) and chemical (enzyme entrapment) methods. PMID:23475318

  17. Inverse effects of Polyacrylamide (PAM) usage in furrow irrigation on advance time and deep percolation.

    PubMed

    Meral, Ramazan; Cemek, Bilal; Apan, Mehmet; Merdun, Hasan

    2006-10-01

    The positive effects of Polyacrylamide (PAM), which is used as a soil conditioner in furrow irrigation, on sediment transport, erosion, and infiltration have been investigated intensively in recent years. However, the effects of PAM have not been considered enough in irrigation system planning and design. As a result of increased infiltration because of PAM, advance time may be inversely affected and deep percolation increases. However, advance time in furrow irrigation is a crucial parameter in order to get high application efficiency. In this study, inverse effects of PAM were discussed, and as an alternative solution, the applicability of surge flow was investigated. PAM application significantly increased the advance time at the rates of 41.3-56.3% in the first irrigation. The application of surge flow with PAM removed this negative effect on advance time, where there was no statistically significant difference according to normal continuous flow (without PAM). PAM applications significantly increased the deep percolation, 80.3-117.1%. Surge flow with PAM had significantly positive effect on the deep percolation compared to continuous flow with PAM but not compared to normal continuous flow. These results suggested that irrigation planning should me made based on the new soil and flow conditions because of PAM usage, and surge flow can be a solution to these problems. PMID:17405332

  18. Tuning colloidal gels by shear.

    PubMed

    Koumakis, Nick; Moghimi, Esmaeel; Besseling, Rut; Poon, Wilson C K; Brady, John F; Petekidis, George

    2015-06-01

    Using a powerful combination of experiments and simulations we demonstrate how the microstructure and its time evolution are linked with mechanical properties in a frustrated, out-of-equilibrium, particle gel under shear. An intermediate volume fraction colloid-polymer gel is used as a model system, allowing quantification of the interplay between interparticle attractions and shear forces. Rheometry, confocal microscopy and Brownian dynamics reveal that high shear rates, fully breaking the structure, lead after shear cessation to more homogeneous and stronger gels, whereas preshear at low rates creates largely heterogeneous weaker gels with reduced elasticity. We find that in comparison, thermal quenching cannot produce structural inhomogeneities under shear. We argue that external shear has strong implications on routes towards metastable equilibrium, and therefore gelation scenarios. Moreover, these results have strong implications for material design and industrial applications, such as mixing, processing and transport protocols coupled to the properties of the final material. PMID:25962849

  19. Nanodosemeters based on gel scintillators.

    PubMed

    Grau Carles, A

    2006-01-01

    The feasibility of a nanodosemeter based on a liquid scintillator cocktail of four components (ethoxylated nonylphenol, pseudocumene, water and a lipophilic mixture) is studied. The dosemeter can work in distinct gel phases, for which the radioactive substance can be confined inside aqueous nanoscale structures of different size. For water volumes ranging 0-15%, it results in a gel with micelles of 4 nm radius. For water volumes ranging 30-50%, the resulting liquid-crystal gel contains nanostructures of approximately 20 nm radius. The low-energy electron emission arising from the decay of (3)H and (55)Fe is counted in a commercial liquid-scintillation counting spectrometer for both homogeneous and gel samples. The counting efficiency gap between the two phases is used to compute the average energy deposited inside the micelle. PMID:17213221

  20. High-pressure gel loader for capillary array electrophoresis microchannel plates.

    PubMed

    Scherer, J R; Paegel, B M; Wedemayer, G J; Emrich, C A; Lo, J; Medintz, I L; Mathies, R A

    2001-11-01

    Microfabricated capillary array electrophoresis (microCAE) microchannel plates are the next generation of bioanalytical separation devices. To fully exploit the capabilities of microCAE devices, supporting technology such as robotic sample loading, gel loading, microplate washing, and data analysis must be developed. Here, we describe a device for loading gel into radial capillary array electrophoresis microplates and for plate washing and drying. The microplates are locked into a loading module, and high-pressure helium is used to drive aqueous separation media or wash solutions into the microchannels through fixtures connected to the central anode reservoir. Microplates are rapidly (30 s to 5 min) loaded with separation media, such as 3%-4.8% linear polyacrylamide or 0.7%-3.0% hydroxyethyl cellulose, for electrophoresis. The effective and rapid gel-filling and plate-cleaning methods together with short electrophoretic analysis times (2-30 min) make microCAE systems versatile and powerful nucleic acid analysis platforms. PMID:11730021

  1. Chiral separation of FITC-labeled amino acids with gel electrochromatography using a polydimethylsiloxane microfluidic device.

    PubMed

    Zeng, Hu-Lie; Li, Haifang; Wang, Xu; Lin, Jin-Ming

    2007-01-01

    A chiral separation model of gel electrochromatography in a polydimethylsiloxane (PDMS) microfluidic device for amino acids (AAs) is presented. Six pairs of fluorescein isothiocyanate (FITC)-labeled dansyl amino acids (Dns-AAs) were separated in a 36-mm effectual separation channel in less than 120 sec, with resolutions all above 0.96. This highly efficient PDMS chiral microfluidic chip was prepared by inserting the mixture solution of monomers, crosslinkers, and radical initiation into the microchannel via syringe. Specifically, allyl-gamma-cyclodextrin (CD) as a chiral selector and crosslinker was bonded in gamma-CD-bonded polyacrylamide (PAA) gel, which was the separation media, and was immobilized in a PDMS microchannel through the stable linkage of 3-(trimethoxysilyl)-propyl methacrylate (Bind-Silane, Sigma, St. Louis, MO, U.S.A.). The preparation not only permitted the prompt chiral separation of AAs, but also extended application of the PDMS microfluidic device by restraining its hydrophobicity through the PAA gel monolithic column. Furthermore, the longevity of the PDMS microfluidic device was prolonged significantly. This can also be a powerful way to develop a rapid and efficient bioanalysis method and portable analytical apparatus. PMID:17685238

  2. BachelorofArts/BachelorofEducation NativeAmericanStudies/NativeEducation

    E-print Network

    Seldin, Jonathan P.

    .__________________ ___ 3. One of (Art and Literature): ___Native American Studies 2300 - North American Indian Art History and Theory ___Native American Studies 2350 - North American Indian Art Studio ___Native American Studies 2600 American Philosophy ___Native American Studies 2500 - Canadian Indian History ___Native American Studies

  3. Literacy Skill Differences between Adult Native English and Native Spanish Speakers

    ERIC Educational Resources Information Center

    Herman, Julia; Cote, Nicole Gilbert; Reilly, Lenore; Binder, Katherine S.

    2013-01-01

    The goal of this study was to compare the literacy skills of adult native English and native Spanish ABE speakers. Participants were 169 native English speakers and 124 native Spanish speakers recruited from five prior research projects. The results showed that the native Spanish speakers were less skilled on morphology and passage comprehension…

  4. Pre-Cast Gel Electrophoresis Guide

    E-print Network

    Kirschner, Marc W.

    Novex® Pre-Cast Gel Electrophoresis Guide Version B January 27, 2003 IM-1002 Novex® Pre-Cast Gel Electrophoresis Guide General information and protocols for using Novex® pre-cast gels www.invitrogen.com tech.....................................................................................................................1 Novex® Pre-Cast Gels

  5. Thermoreversible konjac glucomannan gel crosslinked by borax

    Microsoft Academic Search

    Shanjun Gao; Jinming Guo; Katsuyoshi Nishinari

    2008-01-01

    Dynamic viscoelastic measurements were carried out for novel konjac glucomannan\\/borax gels. Gel networks were formed through the crosslinking reaction between borate ions dissociated from borax and the cis-diol sites on the polysaccharide chains. At lower oscillation frequencies, the complex gels behave like a liquid, whereas at higher frequency they relax like true gel materials with a predominant elastic relaxation response.

  6. Characterization of Sm14 related components in different helminths by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting analysis

    Microsoft Academic Search

    Nilton Thaumaturgo; Mônica Magno Vilar; Ricardo Edelenyi; Miriam Tendler

    2002-01-01

    Sm14 was the first fatty acid-binding protein homologue identified in helminths. Thereafter, members of the same family were identified in several helminth species, with high aminoacid sequence homology between them. In addition, immune crossprotection was also reported against Fasciola hepatica infection, in animals previously immunized with the Schistosoma mansoni vaccine candidate, r-Sm14. In the present study, data on preliminary sodium

  7. Polygonum hydropiper crude root extract mimics estrogenic properties in females: Evidence of uterine protein profiles studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Ajit Hazarika; Hirendra N. Sarma

    2006-01-01

    Polygonum hydropiper is a widely grown weed in the north-eastern states of India. In the present study, estrogenic effects of the crude root extract\\u000a (CRE) ofPolygonum hydropiper on uterine protein was tested in ovary-intact and ovariectomized (OVX) female albino rats. The methanolic crude extract ofPolygonum hydropiper was given to adult ovary-intact and OVX female albino rat in a dose of

  8. High-Resolution Two-Dimensional Polyacrylamide Gel Electrophoresis Reveals a Glucose-Response Protein of 65 kDa in Pancreatic Islet Cells

    Microsoft Academic Search

    Heather Weik Collins; Carol Buettger; Franz Matschinsky

    1990-01-01

    High-resolution two-dimensional PAGE was used to search for glucose-response proteins in isolated pancreatic islets that were labeled with [35S]methionine at ambient glucose concentrations of 0-18 mM. A 65-kDa protein, isoelectric focusing point of approximately 6.6-7.0, was discovered that showed at least a 20-fold stimulation of radiolabeling when glucose in the labeling medium was increased from 3 to 18 mM, in

  9. Application of NMR spectroscopy and multidimensional imaging to the gelcasting process and in-situ real-time monitoring of cross-linking polyacrylamide gels

    SciTech Connect

    Ahuja, S.; Dieckman, S.L.; Gopalsami, N. [and others

    1995-04-01

    In the gelcasting process, a slurry of ceramic powder in a solution of organic monomers is cast in a mold. The process is different from injection molding in that it separates mold-filling from setting during conversion of the ceramic slurry to a formed green part. In this work, NMR spectroscopy and imaging have been conducted for in-situ monitoring of the gelation process and for mapping the polymerization. {sup 1}H nuclear magnetic resonance spectra have been obtained during polymerization of a premix of soluble reactive methacrylamide (monomer) and N, N`-methylene bisacrylamide (cross-linking molecules). The premix was polymerized by adding ammonium persulfate (initiator) and tetramethyl-ethylene-diamine (accelerator) to form long-chain, cross-linked polymers. The time-varying spin-lattice relaxation times T{sub 1} during polymerization have been studied at 25 and 35{degrees}C, and the variation of spectra and T{sub 1} with respect to extent of polymerization has been determined. To verify homogeneous polymerization, multidimensional NMR imaging was utilized for in-situ monitoring of the process. The intensities from the images are modeled and the correspondence shows a direct extraction of T{sub 1} data from the images.

  10. Microwave initiated synthesis of polyacrylamide grafted carboxymethylstarch (CMS-g-PAM): Application as a novel matrix for sustained drug release

    Microsoft Academic Search

    Gautam Sen; Sagar Pal

    2009-01-01

    This paper reports the investigation of microwave initiated synthesized polyacrylamide grafted carboxymethylstarch (CMS-g-PAM) as matrix for sustained drug release. ‘In vitro’ release of a model drug (5-amino salicylic acid) from CMS-g-PAM matrix has been studied. It is evident that higher the percentage grafting, more sustained is the rate of drug release. Further, the percentage grafting vs. t50 value (i.e. time

  11. Adsorption of Congo Red by Poly(Dimethyl Diallyl Ammonium Chloride)\\/Polyacrylamide Hydrogels with Excellent Acid and Alkali Resistance

    Microsoft Academic Search

    Yi Liu; Yian Zheng; Dajian Huang; Aiqin Wang

    2012-01-01

    Cationic hydrogels, poly(dimethyl diallyl ammonium chloride)\\/polyacrylamide (PDMDAAC\\/PAM), were prepared for the removal of congo red (CR) from aqueous solution. Process parameters affecting the adsorption efficiency were systematically investigated. The results showed that the calculated monolayer adsorption capacity of the cationic hydrogels was found to be 200 to 465 mg\\/g. The hydrogels showed appreciable adsorption capacities within pH range investigated. The adsorption

  12. Adsorption of Congo Red by Poly (Dimethyl Diallyl Ammonium Chloride)\\/Polyacrylamide Hydrogels with Excellent Acid and Alkali Resistance

    Microsoft Academic Search

    Yi Liu; Yian Zheng; Dajian Huang; Aiqin Wang

    2012-01-01

    Cationic hydrogels, poly (dimethyl diallyl ammonium chloride)\\/polyacrylamide (PDMDAAC\\/PAM), were prepared for the removal of congo red (CR) from aqueous solution. Process parameters affecting the adsorption efficiency were systematically investigated. The results showed that the calculated monolayer adsorption capacity of the cationic hydrogels was found to be 200 to 465 mg\\/g. The hydrogels showed appreciable adsorption capacities within pH range investigated. The

  13. Gelation properties of dispersions containing polymerized and native whey protein isolate

    Microsoft Academic Search

    Bongkosh Vardhanabhuti; E. Allen Foegeding; Matthew K. McGuffey; Christopher R. Daubert; Harold E. Swaisgood

    2001-01-01

    Whey protein polymers (WP-polymers) were prepared by heating whey protein isolate below the critical concentration for gelation at neutral pH and low salt conditions. The effects of WP-polymers and salt types (CaCl2 or NaCl) on rheological properties (large-strain and small-strain analysis), water holding properties, turbidity and microstructure of heat-induced whey protein isolate gels were investigated. Replacement of native whey protein

  14. Influence of native disulfide bonds of globular proteins on their retention behavior on reverse phase supports

    Microsoft Academic Search

    A. Seetharama Acharya

    1986-01-01

    The reduction of the disulfide bonds of globular proteins, for example, those of lysozyme or ribonuclease-A, results in an increase in the hydrodynamic volume of the polypeptide chain. This is reflected in an earlier elution of the reduced protein on gel filtration compared to that of the native disulfide-bonded form. The reduction of the four disulfide bonds of ribonuclease-A increased

  15. Thixotropic gel for vadose zone remediation

    DOEpatents

    Rhia, Brian D. (Augusta, GA)

    2011-03-01

    A thixotropic gel suitable for use in subsurface bioremediation is provided along with a process of using the gel. The thixotropic gel provides a non-migrating injectable substrate that can provide below ground barrier properties. In addition, the gel components provide for a favorable environment in which certain contaminants are preferentially sequestered in the gel and subsequently remediated by either indigenous or introduced microorganisms.

  16. Thixotropic gel for vadose zone remediation

    DOEpatents

    Riha, Brian D.

    2012-07-03

    A thixotropic gel suitable for use in subsurface bioremediation is provided along with a process of using the gel. The thixotropic gel provides a non-migrating injectable substrate that can provide below ground barrier properties. In addition, the gel components provide for a favorable environment in which certain contaminants are preferentially sequestered in the gel and subsequently remediated by either indigenous or introduced microorganisms.

  17. Development of a chip-based capillary gel electrophoresis method for quantification of a half-antibody in immunoglobulin G4 samples.

    PubMed

    Vasilyeva, Elena; Woodard, James; Taylor, Frederick R; Kretschmer, Matthias; Fajardo, Hans; Lyubarskaya, Yelena; Kobayashi, Kazumi; Dingley, Amy; Mhatre, Rohin

    2004-11-01

    A method based on microfluidic technology was developed to support quantitative analysis of recombinant monoclonal immunoglobulin G4 (IgG4) antibody samples. The assay was performed on an Agilent 2100 Bioanalyzer in combination with the Protein 200 Plus LabChip Kit and the Protein 200 Plus assay software. Capillary electrophoresis principles have been transferred to a chip format that integrates all separation, staining, virtual destaining, and detection steps. The method is referred to in this paper as chip-based capillary gel electrophoresis (GelChip-CE method). The GelChip-CE method under nonreducing conditions proved to be a quantitative test for half-antibody determination in IgG4 samples. Similar to the traditional nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method, the GelChip-CE method includes a denaturing step prior to separation. We showed that denaturing the sample by heating resulted in an artificial increase in the amount of half-antibody detected, which could be prevented by addition of N-ethylmaleimide to the sample buffer. The GelChip-CE method allowed for analysis of IgG4 samples with more accuracy, higher precision, and a faster turnaround time than SDS-PAGE and reversed-phase high-performance liquid chromatography (RP-HPLC). PMID:15565674

  18. Native Americans and the Environment

    NSDL National Science Digital Library

    Created by anthropologist Dr. Alx V. Dark and sponsored by the Center for Conservation Biology at Rice University, this Website promotes the research and study of environmental issues facing Native American communities, particularly the politics of land and treaty rights. The site also explores the "values and historical experiences that Native Americans bring to bear on environmental issues." Native Americans and the Environment provides a bibliographic database, which covers topics such as environmental justice, natural resource utilization, land and treaty rights, and demography and migration. The database currently contains over 1,500 citations, and will be expanded to approximately 3,000 by the end of 1999. The site also includes an extensive directory of hundreds of annotated Internet resources organized by subject and geographic region. In addition, a case studies section is under development and will include environmental problems and their histories, current actions, or solutions; a list of related Internet resources; and a bibliography.

  19. Influence of xanthan gum on physical characteristics of heat-denatured whey protein solutions and gels

    Microsoft Academic Search

    C. M Bryant; D. J McClements

    2000-01-01

    The influence of xanthan on the phase separation, optical properties and rheology of aqueous solutions and gels containing native (N) or heat-denatured (HD) whey protein isolate (WPI) was studied. In the absence of added salt, xanthan promoted phase separation in HD-WPI solutions but not in N-WPI solutions, which was attributed to the increased effective molecular weight of the heated proteins.

  20. Coexistence and interference between a native perennial grass and non-native annual grasses in California

    Microsoft Academic Search

    Jason G. Hamilton; Claus Holzapfel; Bruce E. Mahall

    1999-01-01

    Little is known about the potential for coexistence between native and non-native plants after large-scale biological invasions.\\u000a Using the example of native perennial bunchgrasses and non-native annual grasses in California grasslands, we sought to determine\\u000a the effects of interference from non-native grasses on the different life stages of the native perennial bunchgrass Nassella pulchra. Further, we asked whether N. pulchra

  1. Carbonic anhydrase-facilitated CO2 absorption with polyacrylamide buffering bead capture

    SciTech Connect

    Dilmore, Robert; Griffith, Craid; Liu, Zhu; Soong, Yee; Hedges, Sheila W.; Koepsel, Richard; Ataai, M [Ataai, Mohammad

    2009-07-01

    A novel CO2 separation concept is described wherein the enzyme carbonic anhydrase (CA) is used to increase the overall rate Of CO2 absorption after which hydrated CO2 reacts with regenerable amine-bearing polyacrylamide buffering beads (PABB). Following saturation of the material's immobilized tertiary amines, CA-bearing carrier water is separated and recycled to the absorption stage while CO2-loaded material is thermally regenerated. Process application of this concept would involve operation of two or more columns in parallel with thermal regeneration with low-pressure steam taking place after the capacity of a column of amine-bearing polymeric material was exceeded. PABB CO2- bearing capacity was evaluated by thermogravimetric analysis (TGA) for beads of three acrylamido buffering monomer ingredient concentrations: 0 mol/kg bead, 0.857 mol/kg bead, and 2 mol/kg bead. TGA results demonstrate that CO2- bearing capacity increases with increasing PABB buffering concentration and that up to 78% of the theoretical CO2- bearing capacity was realized in prepared PABB samples (0.857 mol/kg recipe). The highest observed CO2-bearing capacity of PABB was 1.37 mol of CO2 per kg dry bead. TGA was also used to assess the regenerability Of CO2-loaded PABB. Preliminary results suggest that CO2 is partially driven from PABB samples at temperatures as low as 55 degrees C, with complete regeneration occurring at 100 degrees C. Other physical characteristics of PABB are discussed. In addition, the effectiveness of bovine carbonic anhydrase for the catalysis Of CO2 dissolution is evaluated. Potential benefits and drawbacks of the proposed process are discussed. Published by Elsevier Ltd.

  2. Effects of Cationic Polyacrylamide Characteristics on Sewage Sludge Dewatering and Moisture Evaporation

    PubMed Central

    Pan, Chengyi

    2014-01-01

    The effects of the molecular weight (MW) and charge density (CD) of cationic polyacrylamide (CPAM) on sludge dewatering and moisture evaporation were investigated in this study. Results indicated that in sludge conditioning, the optimum dosages were 10, 6, 6, 4, and 4 mg g?1 CPAM with 5 million MW and 20% CD, 5 million MW and 40% CD, 3 million MW and 40% CD, 8 million MW and 40% CD, and 5 million MW and 60% CD, respectively. The optimum dosage of CPAM was negatively correlated with its CD or MW if the CD or MW of CPAM was above 20% or 5 million. In the centrifugal dewatering of sludge, the moisture content in the conditioned sludge gradually decreased with the extension of centrifugation time, and the economical centrifugal force was 400×g. The moisture evaporation rates of the conditioned sludge were closely related to sludge dewaterability, which was in turn significantly correlated either positively with the solid content of sludge particles that were >2 mm in size or negatively with that of particles measuring 1 mm to 2 mm in diameter. During treatment, sludge moisture content was reduced from 80% to 20% by evaporation, and the moisture evaporation rates were 1.35, 1.49, 1.62, and 2.24 times faster in the sludge conditioned using 4 mg g?1 CPAM with 5 million MW and 60% CD than in the sludge conditioned using 4 mg g?1 CPAM with 8 million MW and 40% CD, 6 mg g?1 CPAM with 5 million MW and 40% CD, 6 mg g?1 CPAM with 3 million MW and 40% CD, and 10 mg g?1 CPAM with 5 million MW and 20% CD, respectively. Hence, the CPAM with 5 million MW and 60% CD was ideal for sludge dewatering. PMID:24878582

  3. Coagulation of soil suspensions containing nonionic or anionic surfactants using chitosan, polyacrylamide, and polyaluminium chloride.

    PubMed

    Chatterjee, Tania; Chatterjee, Sudipta; Lee, Dae S; Lee, Min W; Woo, Seung Han

    2009-06-01

    Effective coagulation and separation of particles in a soil-washed solution is required for a successful soil washing process. The effectiveness of chitosan (CS), a polycationic biodegradable polymer, as a coagulant was compared to polyacrylamide (PAA) and polyaluminium chloride (PAC) for the coagulation of a soil suspension (5 gL(-1)). The effect of surfactants in the coagulation process was investigated using Triton X-100 (TX-100), a nonionic surfactant, and sodium dodecyl sulfate (SDS), an anionic surfactant. CS (5 mgL(-1)) removed 86% and 63% of the suspended soil in the presence of TX-100 (5 gL(-1)) and SDS (5 gL(-1)), respectively, after 30 min at a pH of 6. The results prove that coagulation in the presence of TX-100 is more effective than with SDS. CS was found to be more efficient compared to PAA and PAC under all coagulation conditions. The optimum concentration of CS required for maximum coagulation of soil suspension was 5 mgL(-1). PAA and PAC could not achieve the same degree soil removal as CS even after increasing their concentrations up to 50 mgL(-1). Maximum levels of 50% and 60% soil removal were achieved using PAA (50 mgL(-1)) and PAC (50 mgL(-1)), respectively, after 30 min from a 5 gL(-1) suspension containing TX-100 (5 gL(-1)). The soil coagulation process was found to decrease with an increase in the pH of the suspension, and maximum coagulation was achieved with an acidic pH. PMID:19345394

  4. Bilateral breast cancer following augmentation mammaplasty with polyacrylamide hydrogel injection: A case report

    PubMed Central

    ZHAO, YANING; YUAN, NA; LI, KUANZHI; GENG, YI; ZHOU, HAIPING; WANG, HUA; HOU, JIE; ZHANG, BIN; CAI, YUAN; ZHAO, XINHAN

    2015-01-01

    Breast cancer occurring following injection with polyacrylamide hydrogel (PAMG) for augmentation mammaplasty is rare. The present study reports the case of a 43-year-old female presenting with bilateral breast cancer 10 years after augmentation mammaplasty with PAMG injection and no family history of breast cancer. A 5.5×6.0-cm mass in the right breast with multiple intumescent axillary lymph nodes was revealed and a palpable mass of ~1.0 cm was identified in the outer upper quadrant of the left breast. Multiple smaller nodules were observed in the pulmonary field. Pathological examination revealed invasive lobular grade II carcinoma in both breasts with ER(+++), PR(+++), C-erbB2(?), Top-2(+), in the right breast and ER(++), PR(++), c-erb-B2(?), Top-2(+) in the left. Preoperative chemotherapy, modified radical bilateral mastectomy with axillary clearance, postoperative chemotherapy, and an oophorectomy were conducted, followed by treatment with Arimedex® until the present date A number of valuable insights can be garnered from this case. First, close follow-up is required for female patients who receive an injection of PAMG for augmentation mammaplasty in order to achieve an early diagnosis and to intervene in any incidences of breast cancer. Second, the differential diagnosis of dual primary carcinoma versus metastatic breast cancer is important and may be aided by the use of molecular technology. Third, it remains difficult to determine gene expression values for the prediction of chemotherapy sensitivity. Thus, discrimination between primary and secondary carcinomas is the principle barrier for identifying an appropriate treatment strategy when a patient is diagnosed with bilateral breast cancer.

  5. Playing ourselves: Native histories, Native interpreters, and living history sites

    Microsoft Academic Search

    Laura Peers

    1996-01-01

    This study examines the representation of First Nations cultures, people, and histories at six North American public history sites: Lower Fort Garry, Old Fort William, the North West Company Fur Post at Pine City, Colonial Michilimackinac, Waswagoning, and Sainte-Marie among the Hurons. The study examines the history and development of these sites and of their Native interpretation programs. The different

  6. Emulsifying properties and surface behavior of native and denatured whey soy proteins in comparison with other proteins. Creaming stability of oil-in-water emulsions

    Microsoft Academic Search

    Gonzalo G. Palazolo; Delia A. Sorgentini; Jorge R. Wagner

    2004-01-01

    In this work a comparative study of emulsifying and surface behaviors of native whey soy proteins (NWSP) and denatured whey\\u000a soy proteins (DWSP) with those of native soy isolates, denatured soy isolates (DSI), and sodium caseinate was done. These\\u000a samples showed different molecular mass distributions in gel filtration profiles. Dissociation and soluble high-M.W. species\\u000a in DWSP and DSI were observed.

  7. Capillary fracture of soft gels

    NASA Astrophysics Data System (ADS)

    Bostwick, Joshua B.; Daniels, Karen E.

    2013-10-01

    A liquid droplet resting on a soft gel substrate can deform that substrate to the point of material failure, whereby fractures develop on the gel surface that propagate outwards from the contact line in a starburst pattern. In this paper, we characterize (i) the initiation process, in which the number of arms in the starburst is controlled by the ratio of the surface tension contrast to the gel's elastic modulus, and (ii) the propagation dynamics showing that once fractures are initiated they propagate with a universal power law L?t3/4. We develop a model for crack initiation by treating the gel as a linear elastic solid and computing the deformations within the substrate from the liquid-solid wetting forces. The elastic solution shows that both the location and the magnitude of the wetting forces are critical in providing a quantitative prediction for the number of fractures and, hence, an interpretation of the initiation of capillary fractures. This solution also reveals that the depth of the gel is an important factor in the fracture process, as it can help mitigate large surface tractions; this finding is confirmed with experiments. We then develop a model for crack propagation by considering the transport of an inviscid fluid into the fracture tip of an incompressible material and find that a simple energy-conservation argument can explain the observed material-independent power law. We compare predictions for both linear elastic and neo-Hookean solids, finding that the latter better explains the observed exponent.

  8. Native and stearic acid modified ceria-zirconia supports in normal and reversed-phase HPLC.

    PubMed

    Hu, Y L; Feng, Y Q; Wan, J D; Da, S L; Hu, L

    2001-03-30

    Porous ceria-zirconia composite with narrow particle size distribution and large specific surface area was synthesized by a sol-gel process. Chromatographic properties of the native supports was investigated in normal phase mode for the separation of test mixtures of basic, neutral and acidic compounds. The new packing material exhibited polar and basic properties, which are suitable for the separation of basic compounds. Lypophilic packing has been obtained by the modification of the ceria-zirconia with stearic acid, which exhibited strong hydrophobicity relative to the native packing. Therefore, the modified ceria-zirconia behaves as a reversed-phase packing material. Different selectivity towards basic compounds was observed on the new packing compared to the native ceria-zirconia and conventional ODS stationary phase. PMID:18968228

  9. Copolymers For Capillary Gel Electrophoresis

    DOEpatents

    Liu, Changsheng (State College, PA); Li, Qingbo (State College, PA)

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  10. Sol-gel derived sorbents

    DOEpatents

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  11. Native Americans and Alcoholism Therapy

    Microsoft Academic Search

    Alf H. Walle

    2004-01-01

    Substance abuse counselors recognize the diversity of their clients and the fact that specific people have distinct needs and vulnerabilities. Native Americans suffering from alcoholism reflect this reality. Here, the work and perspectives of Handsome Lake, a 19th century spiritual leader of the Iroquois Nation who overcame seemingly incurable alcoholism, are used to show how reaffirming a cultural heritage and

  12. Alaska Native Land Claims. [Textbook].

    ERIC Educational Resources Information Center

    Arnold, Robert D.; And Others

    Written for students at the secondary level, this textbook on Alaska Native land claims includes nine chapters, eight appendices, photographs, maps, graphs, bibliography, and an index. Chapters are titled as follows: (1) Earliest Times (Alaska's first settlers, eighteenth century territories, and other claimants); (2) American Indians and Their…

  13. Two Native Americans' Journey Home.

    ERIC Educational Resources Information Center

    Prussia, Leah L.; Krom, Darla R.

    1998-01-01

    Recounts two personal experiences of graduate school work on Indian Reservations. For one student, it was a returning home to the culture she was familiar with but for the other, who only learned about her Native American heritage in high school, it was an awakening. Their experiences led them to consider the identity problems they observed among…

  14. The Schooling of Native America.

    ERIC Educational Resources Information Center

    Thompson, Thomas, Ed.

    The collection of ten essays by Native Americans who are involved in Indian education includes a preface by Thomas Thompson; "The Indian Student Amid American Inconsistencies" by Vine Deloria, Jr.; "Growing Up in E'da How-One Idaho Girlhood" by LaNada Boyer; "Multicultural Teacher Education at Rough Rock" by Dillon Platero; "Interracial Politics:…

  15. A Mandate for Native History

    ERIC Educational Resources Information Center

    Pember, Mary Annette

    2007-01-01

    The Montana Indian Education For All Act may be setting an audacious national precedent for America's primary and secondary schools. The law requires all Montana schools to include curricula about the history, culture and contemporary status of the state's American Indian population. The new constitutional mandate has eyes throughout Native…

  16. Roadside revegetation by native plants

    Microsoft Academic Search

    M. N. Karim; Azim U. Mallik

    2008-01-01

    Recognizing the severity of road effects and need for developing a natural and self-sustained roadside vegetation cover, this study aimed to provide an ecological basis for selecting desirable native plants based on their autecological attributes by floristic analysis of naturally colonized plants in roadside microhabitats. We hypothesized that (i) vegetation zonation along roadsides is a function of the different microtopography

  17. A template for native plants?

    Microsoft Academic Search

    GR Johnson; Frank C Sorensen; J Bradley; St Clair; Richard C Cronn

    2004-01-01

    Seed movement guidelines for restoration activities are lacking for most native grasses, forbs, and shrubs. The forestry community has decades of experience in establishing seed zones and seed movement guidelines that may be of value to restoration managers. We review the history of seed zone development in forest trees, with emphasis on the Pacific Northwest, and make some suggestions concerning

  18. Native American Adult Reader I.

    ERIC Educational Resources Information Center

    King, Lovern Root, Ed.

    Aspects of Native American history and culture as well as issues and concerns of American Indians are presented in the twelve short articles in this reader for adults. Intended for use in an adult basic education/GED program, the reader features simply written stories (for grades 0-3), illustrations, vocabulary lists and student study questions.…

  19. Amphoteric native defects in semiconductors

    SciTech Connect

    Walukiewicz, W.

    1989-05-22

    We show that a new concept of amphoteric native defects with strongly Fermi level dependent defect formation energy provides the basis for a unified explanation of a large variety of phenomena in semiconductors. Formation of Schottky barriers, particle irradiation induced compensation, doping-induced superlattice intermixing, and limits of free-carrier concentration find for the first time a common simple explanation.

  20. Native Americans in Public Health.

    ERIC Educational Resources Information Center

    Westberg, Jane

    2003-01-01

    The Family Spirit Project provides health and parenting education and in-home support to Navajo and Apache teen parents. The public-health careers of Native professionals allied with the project are described, including a public health administrator, a trainer of field workers, and a medical researcher specializing in communicable diseases that…

  1. NATIVE TERRESTRIAL ANIMAL SPECIES RICHNESS

    EPA Science Inventory

    These data represent predicted current distributions of all native mammals, birds, reptiles, amphibians and butterflies in the Middle-Atlantic region. The data are available for both 8-digit HUCs and EMAP hexagons and represent total species counts for each spatial unit....

  2. Tracer diffusion in colloidal gels

    E-print Network

    Sujin Babu; Jean Christophe Gimel; Taco Nicolai

    2007-05-09

    Computer simulations were done of the mean square displacement (MSD) of tracer particles in colloidal gels formed by diffusion or reaction limited aggregation of hard spheres. The diffusion coefficient was found to be determined by the volume fraction accessible to the spherical tracers ($\\phi_a$) independent of the gel structure or the tracer size. In all cases, critical slowing down was observed at $\\phi_a\\approx 0.03$ and was characterized by the same scaling laws reported earlier for tracer diffusion in a Lorentz gas. Strong heterogeneity of the MSD was observed at small $\\phi_a$ and was related to the size distribution of pores.

  3. Aloha Aina: Native Hawaiians Fight for Survival

    ERIC Educational Resources Information Center

    Kealoha, Gard

    1976-01-01

    Discusses the history, values, and cultural background of the native Hawaiian population, asserting that Hawaiians want to recapture and reaffirm the native rights guaranteed by the constitution of Hawaii in 1846. (Author/JM)

  4. NABS Program: (Native Americans in Biological Science).

    ERIC Educational Resources Information Center

    Gettys, Nancy, Comp.

    1994-01-01

    Describes the four-week summer program of the Native Americans in Biological Sciences Program that engages Native American eighth- and ninth-grade students in studying the problems related to the waste water treatment plant in Cushing, Oklahoma. (MDH)

  5. Asthma and Native Hawaiians/Pacific Islanders

    MedlinePLUS

    ... twice as likely to have asthma as non-Hispanic whites. National data for this population is very ... had asthma, 2012 Native Hawaiian/Pacific Islander Non-Hispanic White Native Hawaiian/Pacific Islander/ Non-Hispanic White ...

  6. Obesity and American Indians/Alaska Natives

    MedlinePLUS

    Obesity and American Indians/Alaska Natives American Indian/Alaska Native women are 30% more likely than non- ... findings/nhqrdr/nhqrdr12/index.html HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  7. Obesity and Native Hawaiians/Pacific Islanders

    MedlinePLUS

    Obesity and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific Islanders were almost four times more likely to ... data available at this time. HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  8. Native Languages Archives Repository Reference Guide

    E-print Network

    Wagner, Diane

    #12;Native Languages Archives Repository Project Reference Guide #12;REFERENCE GUIDE SUMMARY Guide ­ Native Language Preservation, Establishing Archives and Repositories - was produced with funding deterioration of any kind to records or materials. The old lines between archives, libraries, museums

  9. Profile: Native Hawaiians and Pacific Islanders

    MedlinePLUS

    ... origins in any of the original peoples of Hawaii, Guam, Samoa or other Pacific Islands. According to ... 000 Native Hawaiians or Pacific Islanders reside in Hawaii. Some other states that have a significant Native ...

  10. Eagle Feather Tutoring Native American Cultural Center

    E-print Network

    Eagle Feather Tutoring Native American Cultural Center 218 Lory Student Center Colorado State American Cultural Center NACC #12;The Eagle Feather Tutoring Program Mission Statement: The Eagle Feather Feather Tutoring Program Native American Cultural Center NACC #12;

  11. Eagle Feather Tutoring Native American Cultural Center

    E-print Network

    Stephens, Graeme L.

    Eagle Feather Tutoring Native American Cultural Center 218 Lory Student Center Colorado State living things" -Author Unknown Native American Cultural Center NACC #12;The Eagle Feather Tutoring Program Mission Statement: The Eagle Feather Tutoring Program is designed to increase retention

  12. 75 FR 53331 - Alaska Native Claims Selection

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ...to Hadohdleekaga, Incorporated, for the Native village of Hughes, Alaska, pursuant to the Alaska Native Claims Settlement Act...K'oyitl'ots'ina, Limited. The lands are in the vicinity of Hughes, Alaska, and are located in: Kateel River Meridian,...

  13. Using a Gel Probe Equilibrium Sampler to Measure Arsenic Mobilization and Sorption Gradients in Haiwee Reservoir Sediments

    NASA Astrophysics Data System (ADS)

    Campbell, K. M.; Root, R.; O'Day, P. A.; Hering, J. G.

    2005-12-01

    Sediment deposited at Haiwee Reservoir (Olancha, CA, USA) is enriched in arsenic and iron as a result of a large-scale water treatment process to remove naturally occurring arsenic from the Los Angeles Aqueduct (LAA). A poorly crystalline iron oxyhydroxide floc is precipitated in the aqueduct to adsorb dissolved arsenic, removing it from the water column. The iron/arsenic floc then settles in the inlet channel into Haiwee Reservoir. Previous studies at this site indicate that a fraction of the total arsenic is released into the sediment porewaters at depth, most likely as a result of bacterial reductive dissolution of the iron oxyhydroxide. A gel probe equilibrium sampler was used to measure gradients in porewater concentrations and arsenic sorption chemistry in situ in Haiwee Reservoir sediments. The gels were composed of an inert polyacrylamide matrix (92% water). They were inserted into a ladder-like Plexiglas holder, and covered with a 0.45?m membrane filter. The probe was allowed to equilibrate for 24 hours with the sediment porewaters. Two types of gels were deployed simultaneously in the probe: undoped (clear) gels to measure porewater composition, and hydrous ferric oxide (HFO)-doped gels to determine arsenic sorption behavior as a function of porewater composition. Upon removal from the sediments, the gels were re-equilibrated in acid, and a suite of metals and metalloids were measured using ICP-MS. In addition, arsenic speciation was measured in the clear gels using LC-ICP-MS. X-ray absorption spectroscopy was used to determine the oxidation state of arsenic sorbed onto HFO in the doped gels as well as arsenic in sediment cores collected when the gel probes were deployed. Arsenic in the sediment cores was reduced from As(V) to As(III) by a depth of 10 cm, but mixed oxidation states were observed in the porewaters as arsenic was mobilized into the dissolved phase, typically at depths greater than 10 cm. Dissolved arsenic was correlated to iron in the porewaters, indicating that As mobilization was linked to the reductive dissolution of Fe oxyhydroxides in the sediment. Iron reduction occurs deeper in the sediment column than arsenic reduction. Using the gel probe in combination with sediment cores, regions of iron reduction, arsenic mobilization, and arsenic sorption were observed and correlated to other metals such as Sr, Mo, Ba, and W as well as organic carbon. It is likely that sediment porewater composition affects arsenic resorption onto the solid phase. A complex structure of porewater and sorption gradients was observed within these sediments, driven by a combination of bacterial arsenic and iron reduction and porewater chemistry.

  14. Polyacrylamide hydrogels: an effective tool for delivering liquid baits to pest ants (Hymenoptera: Formicidae).

    PubMed

    Buczkowski, Grzegorz; Roper, Elray; Chin, Darren

    2014-04-01

    Ant management in urban and natural areas often relies on toxic baits. Liquid baits are highly attractive to pest ants because they mimic natural food sources such as honeydew and nectar, the principal dietary components of many ants. However, liquid bait use has been limited owing to the lack of bait dispensers that are effective, inexpensive, and easy to service. The current study evaluated the potential of water-storing crystals (polyacrylamide spheres) to effectively deliver liquid thiamethoxam baits to laboratory colonies of Argentine ants, Linepithema humile Mayr. Results of laboratory trials show that bait crystals saturated in 25% sucrose solution containing 0.007% thiamethoxam are highly attractive to Argentine ants and highly effective against all castes and life stages, including workers, queens, and brood. Fresh bait crystals were highly effective and required approximately 2 d to kill all workers and approximately 6 d to achieve complete mortality in queens and brood. Results of bait aging tests show that the crystals lose approximately 70% of moisture in 8 h and the duration of outdoor exposure has a significant effect on moisture loss and subsequently bait acceptance and bait efficacy. A gradual decrease in mortality was observed for all castes and life stages as bait age increased. In general, fresh baits and those aged for < 8 h retained their efficacy and caused substantial mortality. Baits aged longer than 8 h were substantially less attractive and less effective. Horizontal transfer tests examined the transfer of thiamethoxam from live treated donors to live untreated recipients. The results show that donor ants that obtain thiamethoxam by feeding on bait crystals effectively transfer it to untreated recipient ants. The level of secondary mortality depended on the donor:recipient ratio, with approximately 40% recipient worker mortality with the 1:5 ratio and 15% recipient worker mortality with 1:10 or 1:20 ratios. However, no queens died in any transfer tests, suggesting that multiple feedings from multiple donors may be necessary to produce queen mortality. The results of the transfer tests demonstrate the role of trophallaxis in the distribution of thiamethoxam and confirm that thiamethoxam is effectively transferred in Argentine ant colonies. The distribution of thiamethoxam within Argentine ant colonies was further examined using protein marking coupled with an enzyme-linked immunosorbent assay to detect the marker. The distribution of thiamethoxam was highly efficient, with 79 +/- 13% of workers testing positive at 15 min and 100 +/- 0% of workers testing positive at 6 h. In summary, the results of this study demonstrate that water-storing crystals effectively deliver thiamethoxam to all castes and life stages of Argentine ants and may offer an effective tool for Argentine ant management. PMID:24772557

  15. Health disparities in the Native Hawaiian homeless.

    PubMed

    Yamane, David P; Oeser, Steffen G; Omori, Jill

    2010-06-01

    While it is well accepted that Native Hawaiians have poor health statistics compared to other ethnic groups in Hawaii, it is not well documented if these disparities persist when comparing Native Hawaiian homeless individuals to the general homeless population. This paper examines the Native Hawaiian homeless population living in three shelters on the island of Oahu, to determine if there are significant differences in the frequency of diseases between the Native Hawaiian and non-Native Hawaiian homeless. A retrospective data collection was performed using records from the Hawaii Homeless Outreach and Medical Education (H.O.M.E.) project. Data from 1182 patients was collected as of 12/05/09. Information collected included patient demographics, frequency of self reported diseases, family history of diseases, risk factors, prevalence of chronic diseases, and most common complaints. The data from Native Hawaiians and non-Native Hawaiians were examined for differences and a 1-tail Fisher exact analysis was done to confirm significance. The data reveals that the Native Hawaiian homeless population is afflicted more frequently with asthma and hypertension compared to other ethnic groups. While diabetes constituted more visits to the clinics for Native Hawaiians compared to the non-Native Hawaiians, there was no significant difference in patient reported prevalence of diabetes. The Native Hawaiian homeless also had increased rates of risky behaviors demonstrated by higher past use of marijuana and methamphetamines. Interestingly, there was a lower use of alcohol in the Native Hawaiian homeless and no significant difference between Native Hawaiians and non-native Hawaiians in current use of illicit drugs, which may represent a hopeful change in behaviors. These troubling statistics show that some of the health disparities seen in the general Native Hawaiian population persist despite the global impoverished state of all homeless. Hopefully, these results will aid organizations like the H.O.M.E. project to better address the health needs of the Native Hawaiian homeless population. PMID:20540000

  16. Use of Native American Healers Among Native American Patients in an Urban Native American Health Center

    Microsoft Academic Search

    Anne M. Marbella; Mickey C. Harris; Sabina Diehr; Gerald Ignace; Georgianna Ignace

    1998-01-01

    o gain an understanding of the prevalence, utilization patterns, and practice implications of the use of Native American healers together with the use of physicians, we conducted semistructured interviews at an urban Indian Health Service clinic in Milwaukee, Wisc, of a convenience sample of 150 patients at least 18 years old. The mean age of patients was 40 years, and

  17. Predicting bulk mechanical properties of cellularized collagen gels using multiphoton microscopy.

    PubMed

    Raub, C B; Putnam, A J; Tromberg, B J; George, S C

    2010-12-01

    Cellularized collagen gels are a common model in tissue engineering, but the relationship between the microstructure and bulk mechanical properties is only partially understood. Multiphoton microscopy (MPM) is an ideal non-invasive tool for examining collagen microstructure, cellularity and crosslink content in these gels. In order to identify robust image parameters that characterize microstructural determinants of the bulk elastic modulus, we performed serial MPM and mechanical tests on acellular and cellularized (normal human lung fibroblasts) collagen hydrogels, before and after glutaraldehyde crosslinking. Following gel contraction over 16 days, cellularized collagen gel content approached that of native connective tissues (?200 mg ml?¹). Young's modulus (E) measurements from acellular collagen gels (range 0.5-12 kPa) exhibited a power-law concentration dependence (range 3-9 mg ml?¹) with exponents from 2.1 to 2.2, similar to other semiflexible biopolymer networks such as fibrin and actin. In contrast, cellularized collagen gel stiffness (range 0.5-27 kPa) produced concentration-dependent exponents of 0.7 uncrosslinked and 1.1 crosslinked (range ?5-200 mg ml?¹). The variation in E of cellularized collagen hydrogels can be explained by a power-law dependence on robust image parameters: either the second harmonic generation (SHG) and two-photon fluorescence (TPF) (matrix component) skewness (R²=0.75, exponents of -1.0 and -0.6, respectively); or alternatively the SHG and TPF (matrix component) speckle contrast (R²=0.83, exponents of -0.7 and -1.8, respectively). Image parameters based on the cellular component of TPF signal did not improve the fits. The concentration dependence of E suggests enhanced stress relaxation in cellularized vs. acellular gels. SHG and TPF image skewness and speckle contrast from cellularized collagen gels can predict E by capturing mechanically relevant information on collagen fiber, cell and crosslink density. PMID:20620246

  18. The Native American Woman: A Perspective.

    ERIC Educational Resources Information Center

    Medicine, Bea

    Presenting varied perspectives describing the Native American woman, this book is divided into six chapters as follows: (1) Native Americans and Anthropology (this chapter illustrates the way in which anthropologists have helped stereotype American Indian women); (2) The Native American Woman in Ethnographic Perspective (emphasizing role…

  19. Encountering Complexity: Native Musics in the Curriculum.

    ERIC Educational Resources Information Center

    Boyea, Andrea

    1999-01-01

    Describes Native American musics, focusing on issues such as music and the experience of time, metaphor and metaphorical aspects, and spirituality and sounds from nature. Discusses Native American metaphysics and its reflection in the musics. States that an effective curriculum would provide a new receptivity to Native American musics. (CMK)

  20. Native Oyster Restoration: 2006 Workshop Proceedings

    E-print Network

    West Coast Native Oyster Restoration: 2006 Workshop Proceedings September 6-8, 2006 San Rafael, CA.nmfs.noaa.gov/habitat/restoration 2007 #12;#12;West Coast Native Oyster Restoration: 2006 Workshop Proceedings NOAA Restoration Center Center. 2007. West Coast native oyster restoration: 2006 workshop proceedings. U.S. Department